§ 744. =Destruction of the Organic Matter by Nitric Acid, and Subsequent

Reduction of the Arsenic Acid to Arsine (Arseniuretted Hydrogen), and

final Estimation as Metallic Arsenic.=--This process, which is

essentially a combination of several, has been much improved in its

details by R. H. Chittenden and H. H. Donaldson.[784] 100 grms. of the

suspected matters, cut up into small pieces, are heated in a porcelain

dish of suitable size, stirred by means of a glass rod with 23 c.c. of

pure concentrated nitric acid, and heated up to from 150° to 160°. When

the matters assume a yellow or orange colour, the bath is removed from

the source of heat, and 3 c.c. of pure concentrated sulphuric acid

added, and the mixture stirred, when the mass becomes brown, swells up,

and evolves dense nitrous and other fumes. The vessel is again heated to

180°, and while hot 8 c.c. of pure concentrated nitric acid are added,

drop by drop, with continual stirring. After this addition, it is heated

to 200° for fifteen minutes, and the result on cooling is a hard

carbonaceous residue wholly free from nitric acid. The arsenic is in

this way oxidised into arsenic acid, which is easily soluble in water.

The contents of the dish are, therefore, perfectly extracted by boiling

water, the aqueous extract filtered, and evaporated to dryness. The next

process is to obtain the arsenic in a metallic state:--

[784] _American Chem. Journ._, vol. ii., No. 4; _Chem. News_, Jan. 1881,

p. 21.

The flask, a Bunsen’s wash-bottle of 200 c.c. capacity, is provided with

a small separating funnel of 65 c.c. capacity, with glass stop-cock.

This is a very material aid to the obtaining of a slow and even

evolution of gas, an important desideratum when all loss is to be

avoided; for with only a funnel tube, every time a small portion of

fluid is added, a sudden rush of gas takes place, with probably a small,

but still more or less appreciable, loss. But the separating funnel,

filled with the acid mixture, can be so arranged as to give a constant

and regular supply of fluid at the rate of two or three drops per

minute, more or less. The gas generated is dried by a calcic chloride

tube, and then passes through a tube of hard glass, heated to a red heat

by a miniature furnace of three Bunsen lamps with spread burners, so

that a continuous flame of 6 inches is obtained, and with a proper

length of cooled tube not a trace of arsenic passes by. The glass tube

where heated is wound with a strip of wire gauze, both ends being

supported upon the edges of the lamp frame, so that the tube does not

sink down when heated. The small furnace is provided with two

appropriate side pieces of sheet metal, so that a steady flame is always

obtained. When the quantity of arsenic is very small, the tube is

naturally so placed that the mirror is deposited in the narrow portion;

but when the arsenic is present to the extent of 0·005 grm., the tube

should be 6 mm. in inner diameter, and so arranged that fully 2 inches

of this large tube are between the flame and the narrow portion. When

the quantity of arsenic is less, the tube can naturally be smaller.

Acids of different strengths are made as follows:--

Acid No. 1.

545 c.c. pure conc. H₂SO₄.

5000 c.c. H₂O.

Acid No. 2.

109 c.c. pure conc. H₂SO₄.

1640 c.c. Acid No. 1.

Acid No. 3.

218 c.c. pure conc. H₂SO₄.

1640 c.c. Acid No. 1.

Acid No. 4.

530 c.c. pure conc. H₂SO₄.

1248 c.c. H₂O.

25 to 35 grms. of granulated zinc, previously alloyed with a small

quantity of platinum, are placed in the generator, and everything being

in position, the apparatus is filled with hydrogen by the use of a small

quantity of acid No. 2. After a sufficient time has elapsed, the gas is

lighted at the jet, and the glass tube heated to a bright redness.

The arsenical solution in concentrated form is mixed with 45 c.c. of

acid No. 2, and the mixture passed into the separating funnel, from

which it is allowed to flow into the generator at such a rate that the

entire fluid is introduced in one hour or one and a half; 40 c.c. of

acid No. 3 are then added and allowed to flow slowly into the generator,

and, lastly, 45 c.c. of acid No. 4. The amount of time required will

vary with the amount of arsenic: 2 to 3 mgrms. of arsenic will require

about two to three hours for the entire decomposition, while 4 to 5

mgrms. will need perhaps three to four hours. Where the amount of

arsenic is small, only 25 grms. of zinc are needed, and but 45 c.c. of

acid No. 2, 30 c.c. of acid No. 3, and 30 c.c. of acid No. 4; but when

4 to 5 mgrms. of arsenic are present, it is better to take the first

mentioned quantities of zinc and acids.

The arsenic being thus collected as a large or small mirror of metal,

the tube is cut at a safe distance from the mirror, so that a tube of

perhaps 2 to 6 grms. weight is obtained. This is carefully weighed, and

then the arsenic removed by simple heating; or, if the arsenic is to be

saved (as in a toxicological case), dissolved out with strong nitric

acid. The tube is then cleaned, dried, and again weighed, the difference

giving the weight of metallic arsenic, from which, by a simple

calculation, the amount of arsenious oxide can be obtained. Some test

results are given as follows; they were obtained by introducing definite

quantities of arsenious oxide in the form of a solution mixed with 45

c.c. of No. 2 acid, &c.:--

Quantity of Wt. of Metallic Theoretical Wt. of

Arsenic introduced. Arsenic found. Metallic Arsenic.

0·005 grm. As₂O₃ 0·00373 0·00378

0·005 „ „ 0·00370 0·00378

0·004 „ „ 0·00300 0·00303

0·002 „ „ 0·00151 0·00151

Sanger estimates and tests for minute quantities of arsenic by the

Marsh-Berzelius process, and uses a generator of hydrogen; that is to

say, the hydrogen is evolved in the ordinary way from zinc and sulphuric

acid, and the issuing gas dried by calcic chloride; but into this flask

is also delivered from another flask, charged with sulphuric acid and

zinc, pure hydrogen, so that into the second flask, little by little,

may be added the solution to be tested; and, owing to the generating

flask, the gas may be made to give a uniform current, and at the end of

the operation all arsine swept out. To estimate the quantities of

arsenic in the gas, the reduction tube is heated, and a mirror or

mirrors obtained, and compared with a set of standard mirrors. The

standard mirrors are made as follows:--One grm. of arsenious oxide,

purified by repeated sublimation, is dissolved with the aid of a little

sodic bicarbonate, and, after acidification with dilute sulphuric acid,

made up to 1 litre. This standard solution contains 1 mgrm. of As₂O₃ in

every c.c., and is used to make a second standard solution, containing

0·01 mgrm., to every c.c., by diluting 10 c.c. to a litre. Of this last

solution, 1 c.c., 2 c.c., 3 c.c., and so on, are measured and introduced

into the reduction flask, and the standard mirrors obtained. It is

recommended, for obvious reasons, to make more than one standard for

each quantity, for the appearance of the mirrors from the same amount of

arsenic varies. The tubes are hermetically sealed, and, when not in use,

kept in the dark.

This process is convenient for small amounts of arsenic; but, as stated

before, the results are given as metallic arsenic, whereas the films

appear never to be composed of pure metallic arsenic, but a mixture of

hydride and suboxide. Test experiments give, however, fair results.[785]

[785] _Proc. American Academy of Arts and Sciences_, vol. xxvi.

§ 745. =Arsine Developed from an Alkaline Solution.=--Fleitmann

discovered in 1851 that arsenic, mixed with finely divided zinc, and

excess of soda or potash added, evolved arsine; but no stibine was

evolved under the same conditions. In 1873 J. W. Gatehouse suggested the

use of aluminium and sodic hydrate as a modification of Fleitmann’s

test, for the purpose of distinguishing between arsenic and antimony;

and this is now the usual process adopted. The hydrogen comes off

regularly even in the cold, but it is best to apply a little heat. This

test will evolve arsine from arsenious acid, and also from arsenic

trisulphide; but it is not available for the detection of arsenic, when

the arsenic is in the form of arsenic acid. According to Clark,[786] it

is not adapted for quantitative purposes, because, owing to the

formation of solid hydride, about one-fifth remains behind.

[786] _Journ. Chem. Soc._, 1893, 884.

E. W. Davy, in 1876, proposed the use of sodium amalgam for the

generation of arsine; on the whole, it is, however, not so convenient as

the aluminium process.

The liquid to be tested is made strongly alkaline with pure sodic or

potassic hydrate placed in a flask connected with a tube dipping into a

4 per cent. solution of silver nitrate, a few pieces of sheet aluminium

added, and the flask gently heated; any arsine present will reduce the

silver. The silver solution thus blackened may be treated in the manner

described (p. 567).

§ 746. =Precipitation as Tersulphide.=--Despite the advantages of some

of the processes described, which are (to a certain extent) easy and

accurate, not a few chemists still prefer the old method of

precipitation with hydric sulphide SH₂, because, although tedious, it

has stood the test of experience. If this be used, it is well in most

cases to pass sulphurous anhydride through the liquid until it smells

strongly of the gas, for by this means any arsenic acid present is

reduced, the sulphurous anhydride is quickly got rid of by a current of

carbonic anhydride, and then the liquid is saturated with hydric

sulphide. In the ordinary way, much time is often wasted in saturating

the liquid with this gas. Those, however, who have large laboratories,

and daily employ hydric sulphide, possess (or should possess) a water

saturated with the gas under pressure; such a liquid, added in equal

volume to an arsenical solution, is able to convert the whole of the

arsenic into sulphide in a very few minutes. Those who do not possess

this hydric sulphide water can saturate in an hour the liquid to be

tested, by passing the gas in under pressure.[787] A convenient method

is to evolve SH₂ from sulphide of antimony and ClH; the gas passes first

into a wash-bottle, and then into a strong flask containing the solution

under trial. This flask is furnished with a safety-valve, proportioned

to the strength of the apparatus; the two tubes dipping into the

wash-bottle and the last flask are provided with Bunsen’s valves, which

only allow the gas to pass in one direction. The hydric sulphide is then

driven over by heat, and when sufficient gas has in this way passed into

the liquid, the flame is withdrawn, and the apparatus allowed to stand

for some hours, the valves preventing any backward flow of the liquid or

gas. When the precipitate has settled to the bottom, the supernatant

fluid is carefully passed through a filter, and the precipitate washed

by decantation in the flask, without transference to the filter, if it

can be avoided.

[787] Hydric sulphide gas has been liquefied, and is now an article of

commerce, being sold in iron bottles.

The impure sulphide is washed with water, then with alcohol, then with

carbon disulphide, then, after having got rid of the lead, again with

alcohol, and finally with water; it is then dissolved in ammonia, the

ammonia solution filtered, and the filtrate evaporated to dryness on a

sand-bath, at a somewhat high temperature; in this way it is freed from

sulphur and, to a great extent, from organic matter; after weighing, it

may be purified or identified by some of the following methods:--

(_a_) =Solution in Ammonia and Estimation by Iodine.=[788]--The filter

is pierced, the sulphide washed into a flask by ammonia water (which

need not be concentrated), and dissolved by warming, filtered from any

insoluble matter, and estimated by iodine and starch.

[788] P. Champion and H. Pellett, _Bull. Soc. Chim._ (2), xxvj. pp.

541-544.

(_b_) =Oxidation of the Sulphide and Precipitation as Ammonia Magnesian

Arseniate, or Magnesia Pyro-Arseniate.=--The tersulphide, as before, is

dissolved in ammonia (not omitting the filter-paper, which should be

soaked in this reagent), the solution filtered, and evaporated to

dryness. The dry residue is now oxidised by fuming nitric acid, taking

care to protect the dish with a large watch-glass (or other cover)

during the first violent action; the dish is then heated in the

water-bath until all the sulphur has disappeared, and only a small bulk

of the liquid remains; it is then diluted and precipitated by “magnesia

mixture.”[789] The fluid must stand for several hours, and, if the

arsenic is to be determined as the usual ammoniacal salt, it must be

passed through a weighed filter, and washed with a little ammoniacal

water (1 : 3). The solubility of the precipitate is considerable, and

for every 16 c.c. of the filtrate (not the washings) 1 mgrm. must be

allowed. The precipitate, dried at 100°, 2(NH₄MgAsO₄)H₂O, represents

39·47 per cent. metallic arsenic.

[789] Magnesia Mixture:--

Sulphate of magnesia, 1

Chloride of ammonium, 1

Solution of ammonia, 4

Water, 8

Dissolve; then allow to stand for several days; finally filter, and keep

for use.

The solubility of the magnesium arseniate itself, and the general

dislike which chemists have to weighing in such hygroscopic material as

a filter, are, perhaps, the main reasons for the variation of this old

method, which has lately come into notice. Rose proposed some time ago

the conversion of the double salt into the pyro-arseniate--a method

condemned by Fresenius and Parnell, but examined and pronounced a

practicable and accurate process by Remol, Rammelsberg, Thorpe, Fuller,

Wittstein, Emerson, Macivor, Wood, and Brauner. The modification of

Rose’s process, recommended by Wood,[790] and still further improved by

Brauner,[791] may be accepted.

[790] _Zeitschrift für anal. Chem._, vol. xiv. p. 356.

[791] _Ibid._, xvj. pp. 57, 58.

The precipitation is effected by magnesia mixture, with the addition of

half its bulk of alcohol. The solution is allowed to stand for several

hours, until it is possible to decant the clear liquid from the

precipitate; the latter is now dissolved in ClH, reprecipitated as

before, thrown on a small filter, and washed with a mixture of one

volume of ammonia, two volumes of alcohol, and three of water.

The precipitate is now dried, and transferred as completely as possible

from the filter into a small porcelain crucible, included in a larger

one made of platinum, moistened with nitric acid, covered and heated at

first gently, lastly to a bright redness; the filter is then treated

similarly, and the crucible with its contents weighed. Pyro-arseniate of

arsenic (Mg₂As₂O₇) contains 48·29 per cent. of metallic arsenic.

(_c_) =Conversion of the Trisulphide of Arsenic into the Arsenomolybdate

of Ammonia.=--The purified sulphide is oxidised by nitric acid, the acid

solution is rendered alkaline by ammonia, and then precipitated by a

molybdenum solution, made as follows:--100 grms. of molybdic acid are

dissolved in 150 c.c. of ordinary ammonia and 80 of water; this solution

is poured drop by drop into 500 c.c. of pure nitric acid and 300 c.c. of

water; it is allowed to settle, and, if necessary, filtered. The

molybdic solution must be mixed in excess with the liquid under

treatment, the temperature raised to 70° or 80°, and nitric acid added

in excess until a yellow coloration appears; the liquid is then passed

through a tared filter, and dried at 100°. It contains 5·1 per cent. of

arsenic acid [3·3 As].[792]

[792] Champion and Pellett, _Bull. Soc. Chim._, Jan. 7, 1877.

(_d_) =Conversion of the Sulphide into Metallic Arsenic.=--If there

should be any doubt as to the nature of the precipitated substances, the

very best way of resolving this doubt is to reduce the sulphide to

metal; the easiest method of proving this is to dissolve in potash and

obtain arsine by the action of aluminium; or if it is desired to evolve

arsine from an acid solution with zinc in the usual way, then by

dissolving a slight excess of zinc oxide in potash or soda, and

dissolving in this the arsenic sulphide; the zinc combines with all the

sulphur, and converts the sulpharsenite into arsenite; the zinc sulphide

is filtered off, and the filtrate acidified and introduced into Marsh’s

apparatus. The original process of Fresenius was to mix the sulphide

with carbonate of soda and cyanide of potassium, and place the mixture

in the wide part of a tube of hard German glass, drawn out at one end to

a capillary fineness. Carbonic anhydride, properly dried, was passed

through the tube, and the portion containing the mixture heated to

redness; in this way the arsenical sulphide was reduced, and the metal

condensed in the capillary portion, where the smallest quantity could be

recognised. A more elaborate and accurate process, based on the same

principles, has been advocated by Mohr.[793]

[793] Mohr’s _Toxicologie_, p. 57.

A convenient quantity of carbonate of soda is added to the sulphide, and

the whole mixed with a very little water, and gently warmed. The yellow

precipitate is very soon dissolved, and then the whole is evaporated

carefully, until it is in a granular, somewhat moist, adhesive state. It

is now transferred to a glass tube, open at top and bottom, but the top

widened into a funnel; this tube is firmly held perpendicularly on a

glass plate, and the prepared sulphide hammered into a compact cylinder

by the aid of a glass rod, which just fits the tube. The cylinder is now

dried over a flame, until no more moisture is to be detected, and then

transferred into a glass tube 4 or 5 inches long, and with one end drawn

to a point (the weight of this tube should be first accurately taken).

The tube is connected with the following series:--(1) A chloride of

calcium tube; (2) a small bottle containing nitrate of silver solution;

(3) a hydrogen-generating bottle containing zinc and sulphuric acid. The

hydrogen goes through the argentic nitrate solution, leaving behind any

sulphur and arsenic it may contain; it is then dried by chloride of

calcium, and streams in a pure dry state over the cylinder of prepared

sulphide (no error with regard to impurities in the gas is likely to

occur; but in rigid inquiries it is advisable to heat a portion of the

tube, previous to the insertion of the cylinder, for some time, in order

to prove the absence of any external arsenical source); when it is

certain that pure hydrogen, unmixed with air, is being evolved, the

portion of the tube in which the cylinder rests is heated slowly to

redness, and the metallic arsenic sublimes at a little distance from the

source of heat. Loss is inevitable if the tube is too short, or the

stream of hydrogen too powerful.

The tube after the operation is divided, the portion soiled by the soda

thoroughly cleansed, and then both parts weighed; the difference between

the weight of the empty tube and the tube + arsenic gives the metallic

arsenic. This is the process as recommended by Mohr; it may, however, be

pointed out that the glass tube itself loses weight when any portion of

it is kept red-hot for some little time; and, therefore, unless the

crust is required in the original tube, it is better to divide it,

carefully weigh the arsenical portion, remove the crust, and then

re-weigh. The method is not perfectly accurate. The mirror is not pure

metallic arsenic (see p. 571), and if the white alkaline residue be

examined, arsenic will be detected in it, the reason being that the

arsenical sulphide generally contains pentasulphide of arsenic as well

as free sulphur. Now the pentasulphide does not give up metallic arsenic

when treated as before detailed; nor, indeed, does the trisulphide, if

mixed with much sulphur, yield an arsenical crust. It is, therefore, of

great moment to free the precipitate as much as possible from sulphur,

before attempting the reduction.

The development of a reducing gas from a special and somewhat

complicated apparatus is not absolutely necessary. The whole process of

reduction, from beginning to end, may take place in a single tube by any

of the following processes:--(1) The sulphide is mixed with oxalate of

soda (a salt which contains no water of crystallisation), and the dry

mixture is transferred to a suitable tube, sealed at one end. An

arsenical mirror is readily obtained, and, if the heat is continued long

enough, no arsenic remains behind--an excellent and easy method, in

which the reducing gas is carbonic oxide, in an atmosphere of carbonic

anhydride. (2) The sulphide is oxidised by _aqua regia_, and the

solution evaporated to complete dryness. The residue is then dissolved

in a few drops of water, with the addition of some largish grains of

good wood charcoal (which absorb most of the solution), and the whole

carefully dried. The mass is now transferred to a tube closed at one

end, a little charcoal added in the form of an upper layer, and heat

applied first to this upper layer, so as to replace the air with CO₂,

and then to bring the whole tube gradually to redness from above

downwards. In this case also the whole of the arsenic sublimes as a

metallic mirror.

There are various other modifications, but the above are trustworthy,

and quite sufficient. Brugelmann’s method of determining arsenic,

elsewhere described, would appear to possess some advantages, and to

promise well; but the writer has had no personal experience of it with

regard to arsenic.

§ 747. =Conversion of Arsenic into Arsenious Chloride= (AsCl₃).--This

process, first employed by Schneider and Fyfe, and afterwards modified

by Taylor, differs from all the preceding, since an attempt is made to

separate by one operation volatile metallic chlorides, and to

destroy the organic matter, and thus obtain two liquids--one a

distillate--tolerably clear and free from solid particles, whilst the

mass in the retort retains such metals as copper, and is in every way

easy to deal with.

Schneider and Fyfe employed sulphuric acid and common salt; but Taylor

recommends hydrochloric acid, which is in every respect preferable. As

recommended by Taylor, all matters, organic or otherwise, are to be

completely desiccated before their introduction into a retort, and on

these dried substances sufficient pure hydrochloric acid poured, and the

distillation pushed to dryness. Every one is well aware how tedious is

the attempt to dry perfectly the organs of the body (such as liver, &c.)

at any temperature low enough to ensure against volatilisation of such a

substance as, _e.g._, calomel. This drying has, therefore, been the

great stumbling-block which has prevented the general application of the

process. It will be found, however, that drying in the ordinary way is

by no means necessary. The writer cuts up the solid organ (such as

liver, brain, &c.) with scissors into small pieces, and transfers them

to a retort fitted by an air-tight joint to a Liebig condenser; the

condenser in its turn being connected with a flask by a tube passing

through an india-rubber stopper dipping into a little water. Another

tube from the same flask is connected with india-rubber piping, which is

connected with a water-pump, the fall tube of which terminates in the

basement of a house over a gully. The distillation is now carried on to

carbonisation; on cooling, a second quantity of hydrochloric acid is

added, and the last fraction of the distillate examined for arsenic. If

any is found, a third distillation is necessary. At the termination of

the operation the retort is washed with water, the solution filtered,

and this solution and the distillate are each separately examined for

arsenic. If properly performed, however, the second distillation brings

over the whole of the arsenical chloride,[794] and none will be found in

the retort. With the above arrangement there can be no odour, nor is

there any loss of substance. In the distillate the arsenic can hardly be

in the form of arsenious chloride, but rather arsenious acid and

hydrochloric acid; for the chloride easily splits up in the presence of

water into these substances. It is best to convert it into the

trisulphide. Taylor[795] recommends evolving arsine in the usual way,

and passing the arsine (AsH₃) into solution of silver nitrate, finally

estimating it as an arseniate of silver. Objections with regard to the

impurity of reagents should be met by blank experiments. Kaiser[796]

has proposed and practised a modification of this method, which

essentially consists in the use of sulphuric acid and sodic chloride (as

in Schneider and Fyfe’s original process), and in passing the distillate

first into a flask containing a crystal or two of potassium chlorate,

and thence into an absorption bulb; in the latter most of the arsenic is

found in the form of arsenic acid, the chloride having been oxidised in

its passage. The apparatus is, however, complicated in this way without

a corresponding advantage.[797] Lastly, E. Fischer[798] has shown that

it is a considerable advantage to add from 10 to 20 c.c. of a saturated

solution of ferrous chloride before distilling with HCl. In this way all

the arsenic, whether as arsenic or arsenious acids, is easily converted

into chloride.

[794] Dragendorff asserts to the contrary; but we may quote the

authority of Taylor, who has made several experiments, in which he

obtained all the arsenic as chloride. The writer has performed the

process many times, each time carefully testing the mass in the retort

for arsenic; but the result proved that it had entirely passed over.

[795] _Principles of Medical Jurisprudence_, vol. i. p. 267.

[796] _Zeitschr. f. anal. Chem._, xiv. pp. 250-281.

[797] Selmi (_Atti dell. Accademia dei Lincei_, Fasc. ii., 1879)

proposed a modification of Schneider’s process. The substances are

treated with hot, pure sulphuric acid, and at the same time the liquid

is traversed by a stream of hydrochloric acid gas. The resulting

distillate is tested for arsenic by Marsh’s process. Selmi states that,

operating in this way, he has detected 1/400 of a mgrm. of As₂O₃ in 100

grms. of animal matter.

[798] _Scheidung u. Bestimmung d. Arsens_; Liebig’s _Annalen d. Chemie_,

Bd. ccvii. p. 182.

2. ANTIMONY.

§ 748. =Metallic Antimony.=--Atomic weight, 120·3 (R. Schneider), 120·14

(Cook[799]); specific gravity, 6·715; fusing-point about 621° (1150°

F.). In the course of analysis, metallic antimony may be seen as a black

powder thrown down from solutions; as a film deposited on copper or

platinum; and, lastly, as a ring on the inside of a tube from the

decomposition of stibine. At a bright red-heat it is volatilised slowly,

even when hydrogen is passed over it; chlorine, bromine, and iodine

combine with it directly. It may be boiled in concentrated ClH without

solution; but _aqua regia_, sulphides of potassium and sodium readily

dissolve it. The distinction between thin films of this metal and of

arsenic on copper and glass are pointed out at pp. 557 and 559. It is

chiefly used in the arts for purposes of alloy, and enters to a small

extent into the composition of fireworks (_vide_ pp. 534 and 581).

[799] _Ann. Phys. Chem._ (2), v. pp. 255-281.

§ 749. =Antimonious Sulphide.=--Sulphide of antimony = 336; composition

in 100 parts, Sb 71·76, S 28·24. The commercial article, known under the

name of black antimony, is the native sulphide, freed from silicious

matter by fusion, and afterwards pulverised. It is a crystalline

metallic-looking powder, of a steel-grey colour, and is often much

contaminated with iron, lead, copper, and arsenic.

The amorphous sulphide (as obtained by saturating a solution of tartar

emetic with SH₂) is an orange-red powder, soluble in potash and in

ammonic, sodic, and potassic sulphides; and dissolving also in

concentrated hydrochloric acid with evolution of SH₂. It is insoluble in

water and dilute acid, scarcely dissolves in carbonate of ammonia, and

is quite insoluble in potassic bisulphite. If ignited gently in a stream

of carbonic acid gas, the weight remains constant. To render it

anhydrous, a heat of 200° is required.

The recognition of arsenic in the commercial sulphide is most easily

effected by placing 2 grms. or more in a suitable retort (with

condenser), adding hydrochloric acid, and distilling. The chloride of

arsenic passes over before the chloride of antimony; and by not raising

the heat too high, very little antimony will come over, even if the

distillation be carried almost to dryness. The arsenic is detected in

the distillate by the ordinary methods.

Several lamentable accidents have happened through mistaking the

sulphide of antimony for oxide of manganese, and using it with potassic

chlorate for the production of oxygen. The addition of a drop of

hydrochloric acid, it is scarcely necessary to say, will distinguish

between the two.

Antimony is frequently estimated as sulphide. An amorphous tersulphide

of mercury, containing a small admixture of antimonious oxide and

sulphide of potassium, is known under the name of _Kermes mineral_, and

has lately been employed in the vulcanising of india-rubber. Prepared in

this way, the latter may be used for various purposes, and thus become a

source of danger. It behoves the analyst, therefore, in searching for

antimony, to take special care not to use any india-rubber fittings

which might contain the preparation.

A _pentasulphide of antimony_ (from the decomposition of Schleppe’s salt

[Na₃Sb₆S₄ + 9H₂O], when heated with an acid) is used in calico-printing.

§ 750. =Tartarated Antimony, Tartrate of Potash and Antimony, or Tartar

Emetic=, is, in a medico-legal sense, the most important of the

antimonial salts. Its formula is KSbC₄H₄O₇H₂O, and 100 parts,

theoretically, should contain 35·2 per cent. of metallic antimony. The

B.P. gives a method of estimation of tartar emetic not free from error,

and Professor Dunstan has proposed the following:--Dissolve 0·3 grm. of

tartar emetic in 80 c.c. of water, add to this 10 c.c. of a 5 per cent.

solution of sodium bicarbonate, and immediately titrate with a

decinormal solution of iodine, using starch as an indicator. One c.c. of

_n_/10 iodine = 0·0166 grm. tartar emetic; therefore, if pure, the

quantity used by 0·3 grm. should be 18 c.c. Tartar emetic occurs in

commerce in colourless, transparent, rhombic, octahedral crystals,

slightly efflorescing in dry air.

A crystal, placed in the subliming cell (p. 258), decrepitates at 193·3°

(380° F.), sublimes at 248·8° (480° F.) very slowly and scantily, and

chars at a still higher temperature, 287·7° (550° F.). On evaporating a

few drops of a solution of tartar emetic, and examining the residue by

the microscope, the crystals are either tetrahedra, cubes, or branched

figures. 100 parts of cold water dissolve 5 of tartar emetic, whilst the

same quantity of boiling water dissolves ten times as much, viz., 50.

The watery solution decomposes readily with the formation of algæ; it

gives no precipitate with ferrocyanide of potassium, chloride of barium,

or nitrate of silver, unless concentrated.

§ 751. =Metantimonic Acid=, so familiar to the practical chemist from

its insoluble sodium salt, is technically applied in the painting of

glass, porcelain, and enamels; and in an impure condition, as antimony

ash, to the glazing of earthenware.

§ 752. =Pharmaceutical, Veterinary, and Quack Preparations of

Antimony.=[800]

[800] The history of antimony as a drug is curious. Its use was

prohibited in France in 1566, because it was considered poisonous, one

Besnier being actually expelled from the faculty for transgressing the

law on this point. The edict was repealed in 1650; but in 1668 there was

a fresh enactment, confining its use to the doctors of the faculty.

(1) =Pharmaceutical Preparations=:--

=Oxide of Antimony= (Sb₂O₃) is a white powder, fusible at a low red

heat, and soluble without effervescence in hydrochloric acid, the

solution responding to the ordinary tests for antimony. Arsenic may be

present in it as an impurity; the readiest means of detection is to

throw small portions at a time on glowing charcoal, when very small

quantities of arsenic will, under such conditions, emit the peculiar

odour. Carbonate of lime appears also to have been found in the oxide of

commerce.

=Antimonial Powder= is composed of one part of oxide of antimony and two

parts of phosphate of lime; in other words, it ought to give 33·3 per

cent. of Sb₂O₃.

=Tartar Emetic= itself has been already described. The preparations used

in medicine are--

=The Wine of Antimony= (=Vinum antimoniale=), which is a solution of

tartar emetic in sherry wine, and should contain 2 grains of the salt in

each ounce of the wine (0·45 grm. in 100 c.c.).

=Antimony Ointment= (=Unguentum antimonii tartarati=) is a mechanical

mixture of tartar emetic and lard, or simple ointment;[801] strength 20

per cent. There is no recorded case of conviction for the adulteration

of tartar emetic; cream of tartar is the only probable addition. In such

a case the mixture is less soluble than tartar emetic itself, and on

adding a small quantity of carbonate of soda to a boiling solution of

the suspected salt, the precipitated oxide at first thrown down, becomes

redissolved.

[801] Simple ointment is composed of white wax 2, lard 3, almond oil 3

parts.

=Solution of Chloride of Antimony= is a solution of the terchloride in

hydrochloric acid; it is a heavy liquid of a yellowish-red colour,

powerfully escharotic; its specific gravity is 1·47; on dilution with

water, the whitish-yellow oxychloride of antimony is precipitated. One

drachm (3·549 c.c.) mixed with 4 ounces (112 c.c.) of a solution of

tartaric acid (·25 : 4) gives a precipitate with SH₂, which weighs _at

least_ 22 grains (1·425 grm.). This liquid is used on very rare

occasions as an outward application by medical men; farriers sometimes

employ it in the foot-rot of sheep.

=Purified Black Antimony= (=Antimonium nigrum purificatum=) is the

purified native sulphide Sb₂S₃; it should be absolutely free from

arsenic.

=Sulphurated Antimony= (=Antimonium sulphuratum=) is a mixture of

sulphide of antimony, Sb₂S₃, with a small and variable amount of oxide,

Sb₂O₃. The P.B. states that 60 grains (3·888 grms.) dissolved in ClH,

and poured into water, should give a white precipitate of oxychloride of

antimony, which (properly washed and dried) weighs about 53 grains

(3·444 grms.). The officinal compound pill of subchloride of mercury

(_Pilula hydrargyri subchloridi composita_) contains 1 grain (·0648

grm.) of sulphurated antimony in every 5 grains (·324 grm.), _i.e._, 20

per cent.

(2) =Patent and Quack Pills=:--

=Dr. J. Johnson’s Pills.=--From the formula each pill should

contain:--

Grains. Grms.

Compound Extract of Colocynth, 2·5 = ·162

Calomel, ·62 = ·039

Tartar Emetic, ·04 = ·002

Oil of Cassia, ·12 = ·007

---- ----

3·28 = ·210

The oil of cassia can be extracted by petroleum ether; the calomel

sublimed and identified by the methods given in the article on

“Mercury”; the antimony deposited in the metallic state on platinum

or tin; and the colocynth extracted by dissolving in water,

acidifying, and shaking up with chloroform. On evaporating the

chloroform the residue should taste extremely bitter; dissolved in

sulphuric acid it changes to a red colour, and dissolved in Fröhde’s

reagent to a cherry-red. It should also have the ordinary reactions

of a glucoside.

=Mitchell’s Pills= contain in each pill:--

Grains. Grms.

Aloes, 1·1 = ·070

Rhubarb, 1·6 = ·103

Calomel, ·16 = ·010

Tartar Emetic, ·05 = ·003

---- ----

2·91 = ·186

The mineral substances in this are easy of detection by the methods

already given; the aloes by the formation of chrysammic acid, and

the rhubarb by its microscopical characters.

=Dixon’s Pills= probably contain the following in each pill:--

Grains. Grms.

Compound Extract of Colocynth, 2·0 = ·1296

Rhubarb, 1·0 = ·0648

Tartar Emetic, ·06 = ·0038

---- -----

3·06 = ·1982

(3) =Antimonial Medicines, chiefly Veterinary=:[802]--

[802] There has long prevailed an idea (the truth of which is doubtful)

that antimony given to animals improves their condition; thus, the

_Encyclop. Brit._, 5th ed., art. “Antimony”:--“A horse that is lean and

scrubby, and not to be fatted by any means, will become fat on taking a

dose of antimony every morning for two months together. A boar fed for

brawn, and having an ounce of antimony given him every morning, will

become fat a fortnight sooner than others put into the stye at the same

time, and fed in the same manner, but without the antimony.” Probably

the writer means by the term _antimony_ the impure sulphide. To this may

be added the undoubted fact, that in Brunswick the breeders of fat geese

add a small quantity of antimonious oxide to the food, as a traditional

custom.

=Liver of Antimony= is a preparation formerly much used by farriers.

It is a mixture of antimonious oxide, sulphide of potassium,

carbonate of potassium, and undecomposed trisulphide of antimony

(and may also contain sulphate of potassium), all in very

undetermined proportions. When deprived of the soluble potash salts,

it becomes the _washed saffron of antimony_ of the old pharmacists.

A receipt for a grease-ball, in a modern veterinary work, gives,

with liver of antimony, cream of tartar and guaiacum as ingredients.

=Hind’s Sweating-ball= is composed of 60 grains (3·888 grms.) of

tartar emetic and an equal portion of assafœtida, made up into a

ball with liquorice-powder and syrup. The assafœtida will be readily

detected by the odour, and the antimony by the methods already

recommended.

=Ethiops of Antimony=, very rarely used now, is the mechanical

mixture of the sulphides of antimony and mercury--proportions, 3 of

the former to 2 of the latter.

=The Flowers of Antimony= is an impure oxysulphide of antimony, with

variable proportions of trioxide and undecomposed trisulphide.

=Diaphoretic Antimony= (=calcined antimony=) is simply antimoniate

of potash.

=Glass of Antimony= is a mixture of sulphide and oxide of antimony,

contaminated with a small quantity of silica and iron.

A quack pill, by name, =Ward’s Red Pill=, is said to contain glass

of antimony and dragon’s blood.

=Antimonial Compounds used in Pyrotechny=:--

Blue Fire:--

Antimonious sulphide, 1

Sulphur, 2

Nitre, 6

This composition is used for the blue or Bengal signal-light at sea.

Bisulphide of carbon and water are solvents which will easily

separate the powder into its three constituents.

Crimson Fire:--

Potassic Chlorate, 17·25

Alder or Willow Charcoal, 4·5

Sulphur, 18·

Nitrate of Strontia, 55·

Antimonious Sulphide, 5·5

The spectroscope will readily detect strontia and potassium, and the

analysis presents no difficulty. In addition to these a very great

number of other pyrotechnical preparations contain antimony.

§ 753. =Alloys.=--Antimony is much used in alloys. The ancient

_Pocula emetica_, or everlasting emetic cups, were made of antimony,

and with wine standing in them for a day or two, they acquired

emetic properties. The principal antimonial alloys are Britannia and

type metal, the composition of which is as follows:--

Tin, Copper, Antimony,

per cent. per cent. per cent.

Britannia Metal, Best, 92·0 1·8 6·2

Common, 92·1 2·0 5·9

For Castings, 92·9 1·8 5·3

For Lamps, 94·0 1·3 4·7

Tea Lead, Antimony, Block Tin,

per cent. per cent. per cent.

Type Metal, { (1.) 75 20 5

{ (2.) 70 25 5

Metal for Stereotype, 84·2 13·5 2·3

There is also antimony in brass, concave mirrors, bell-metal, &c.

§ 754. =Pigments.=--Cassella and Naples yellow are principally

composed of the antimoniate of lead.

=Antimony Yellow= is a mixture of antimoniate of lead with basic

chloride of lead.

§ 755. =Dose.=--A medicinal dose of a soluble antimonial salt should not

exceed 97·2 mgrms. (1½ grain). With circumstances favouring its action,

a dose of 129·6 mgrms. (2 grains) has proved fatal;[803] but this is

quite exceptional, and few medical men would consider so small a

quantity dangerous for a healthy adult, especially since most

posological tables prescribe tartar emetic as an emetic in doses from

64·8 to 194·4 mgrms. (1 to 3 grains). The smallest dose which has killed

a child appears to be 48·5 mgrms. (¾ grain).[804] The dose of tartar

emetic for horses and cattle is very large, as much as 5·832 grms. (90

grains) being often given to a horse in his gruel three times a day. 3·8

grms. (60 grains) are considered a full, but not an excessive, dose for

cattle; ·38 grm. (6 grains) is used as an emetic for pigs, and half this

quantity for dogs.

[803] Taylor, Guy’s Hosp. Reports, Oct. 1857.

[804] Op. cit.

§ 756. =Effects of Tartar Emetic and of Antimony Oxide on

Animals.=--Large doses of tartar emetic act on the warm-blooded animals

as on man; whether the poison is taken by the mouth, or injected

subcutaneously, all animals able to vomit[805] do so. The heart’s

action, at first quickened, is afterwards slowed, weakened, and lastly

paralysed. This action is noticed in cold as well as in warm-blooded

animals. It is to be ascribed to a direct action on the heart; for if

the brain and spinal cord of the frog be destroyed--or even if a

solution of the salt be applied direct to the frog’s heart separated

from the body--the effect is the same. The weak action of the heart, of

course, causes the blood-pressure to diminish, and the heart stops in

diastole. The voluntary muscles of the body are also weakened; the

breathing is affected, partly from the action on the muscles. The

temperature of the body is depressed (according to F. A. Falck’s

researches) from 4·4° to 6·2°.

[805] L. Hermann (_Lehrbuch der experimentellen Toxicologie_) remarks

that the vomiting must be considered as a reflex action from the

inflammatory excitement of the digestive apparatus, especially of the

stomach. It is witnessed if the poison is administered subcutaneously or

injected into the brain. Indeed, it is established that (at least, so

far as the muscles are concerned) the co-ordinated movements producing

vomiting are caused by excitement of the medulla oblongata. Giannussi

and others found that after section between the first and third vertebræ

of dogs, and subsequent administration of tartar emetic, no vomiting

took place; and Grimm’s researches seem to show that the suspected

_vomit-centre_ is identical with the respiratory centre, so that the

vomiting movement is only an abnormal respiratory movement. L. Hermann,

however, considers the theory that when tartar emetic is introduced into

the vessels the _vomit-centre_ is directly excited, erroneous, for (1)

in introducing it by the veins much larger doses are required to excite

vomiting than by the stomach; and (2), after subcutaneous injection of

the salt, antimony is found in the first vomit. His explanation,

therefore, is that antimony is excreted by the intestinal tract, and in

its passage excites this action. Majendie’s well-known

experiment--demonstrating that, after extirpation of the stomach,

vomiting movements were noticed--is not considered opposed to this view.

The effect of small doses given repeatedly to animals has been several

times investigated. Dr. Nevin[806] experimented upon eleven rabbits,

giving them tartar emetic four times a day in doses of 32·4 mgrms. (½

grain), 64·8 mgrms. (1 grain), and 129·6 mgrms. (2 grains). Five died,

the first after four, the last after seventeen days; three were killed

after one, three, and four days respectively, two after an interval of

fourteen days, and one thirty-one days after taking the last dose. There

was no vomiting; diarrhœa was present in about half the number; one of

the rabbits, being with young, aborted. The chief symptoms were general

dulness, loss of appetite, and in a few days great emaciation. Four of

the five that died were convulsed before death, and several of the

animals exhibited ulcers of the mucous membrane of the mouth, in places

with which the powder had come in contact. Caillol and Livon have also

studied the action of small doses of the white oxide of antimony given

in milk to cats. A cat took in this way in 109 days ·628 grm. The animal

passed gradually into a cachectic state, diarrhœa supervened, and it

died miserably thin and exhausted.

[806] Lever, _Med. Chir. Journ._, No. 1.

§ 757. =Effects of Tartar Emetic on Man.=[807]--The analogy between the

symptoms produced by arsenic and antimony is striking, and in some acute

cases of poisoning by tartar emetic, there is but little (if any)

clinical difference. If the dose of tartar emetic is very large, there

may be complete absence of vomiting, or only a single evacuation of the

stomach. Thus, in a case mentioned by Taylor, in which a veterinary

surgeon swallowed by mistake 13 grms. (200 grains) of tartar emetic,

vomiting after fifteen minutes could only be induced by tickling the

throat. So, again, in the case reported by Mr. Freer, a man, aged 28,

took 7·77 grms. (120 grains) of tartar emetic by mistake for Epsom

salts; he vomited only once; half an hour after taking the poison he had

violent pain in the stomach and abdomen, and spasmodic contraction of

the abdomen and arms; the fingers were firmly contracted, the muscles

quite rigid, and there was involuntary aqueous purging. After six hours,

during which he was treated with green tea, brandy, and decoction of

oak-bark, he began to recover, but suffered for many nights from profuse

perspirations.

[807] Antimony occasionally finds its way into articles of food through

obscure channels. Dr. Page has recorded the fact of antimonial lozenges

having been sold openly by an itinerant vendor of confectionery. Each

lozenge contained nearly a quarter of a grain (·16 mgrms.), and they

caused well-marked symptoms of poisoning in the case of a servant and

two children. How the antimony got in was unknown. In this case it

appears to have existed not as tartar emetic, but as an insoluble oxide,

for it would not dialyse in aqueous solution.--“On a remarkable instance

of Poisoning by means of Lozenges containing Antimony,” by David Page,

M.D., Medical Officer of Health, _Lancet_, vol. i., 1879, p. 699.

With more moderate and yet large doses, nausea and vomiting are very

prominent symptoms, and are seldom delayed more than half an hour. The

regular course of symptoms may therefore be summed up thus:--A metallic

taste in the mouth, repeated vomitings, which are sometimes bloody,

great faintness and depression, pains in the abdomen and stomach, and

diarrhœa, which may be involuntary. If the case is to terminate fatally,

the urine is suppressed, the temperature falls, the face becomes

cyanotic, delirium and convulsions supervene, and death occurs in from

two to six days. Antimony, like arsenic, often produces a pustular

eruption. Solitary cases deviate more or less from the course described,

_i.e._, severe cramps affecting all the muscles, hæmorrhage from the

stomach, kidney, or bowel, and death from collapse in a few hours, have

all been noticed. In a case recorded by Mr. Morley,[808] a surgeon’s

daughter, aged 18, took by mistake an unknown quantity of antimonial

wine; she soon felt sleepy and powerless, and suffered from the usual

symptoms in combination with tetanic spasms of the legs. She afterwards

had enteritis for three weeks, and on recovery her hair fell off. Orfila

relates a curious case of intense spasm of the gullet from a large dose

of tartar emetic.

[808] _Brit. Med. Journ._, Oct. 14, p. 70.

§ 758. =Chronic Antimonial Poisoning.=--The cases of Palmer and J. P.

Cook, M. Mullen, Freeman, Winslow, Pritchard, and the remarkable Bravo

case have, in late years, given the subject of chronic antimonial

poisoning a considerable prominence. In the trials referred to, it was

shown that medical men might easily mistake the effects of small doses

of antimony given at intervals for the action of disease--the symptoms

being great nausea, followed by vomiting, chronic diarrhœa, alternating

with constipation, small frequent pulse, loss of voice, great muscular

weakness, depression, with coldness of the skin and a clammy

perspiration. In the case of Mrs. Pritchard,[809] her face was flushed,

and her manner so excited as to give an ordinary observer the idea that

she had been drinking; and with the usual symptoms of vomiting and

purging, she suffered from cramps in the hands. Dr. Pritchard tried to

make it appear that she was suffering from typhoid fever, which the

symptoms in a few respects only resembled.

[809] _Edin. Med. Journ._, 1865.

According to Eulenberg, workmen, exposed for a long period to the vapour

of the oxide of antimony, suffer pain in the bladder and a burning

sensation in the urethra, and continued inhalation even leads to

impotence and wasting of the testicles.[810]

[810] In the first operations of finishing printers’ types, the workmen

inhale a metallic dust, which gives rise to effects similar to lead

colic; and probably in this case the lead is more active than the

associated antimony.

§ 759. =Post-mortem Appearances.=--The effect of large doses of tartar

emetic is mainly concentrated upon the gastro-intestinal mucous

membrane. There is an example in the museum of University College

Hospital of the changes which resulted from the administration of tartar

emetic in the treatment of pneumonia. These are ascribed in the

catalogue, in part to the local action of the medicine, and in part to

the extreme prostration of the patient. In the preparation (No. 1052)

the mucous membrane over the fore border of the epiglottis and adjacent

part of the pharynx has been destroyed by sloughing; the ulceration

extends into the upper part of the œsophagus. About an inch below its

commencement, the mucous membrane has been entirely removed by sloughing

and ulceration, the circular muscular fibres being exposed. Above the

upper limit of this ulcer, the mucous membrane presents several oval,

elongated, and ulcerated areas, occupied by strips of mucous membrane

which have sloughed. In other places, irregular portions of the mucous

membrane, of a dull ashen-gray colour, have undergone sloughing; the

edges of the sloughing portion are of colours varying from brown to

black.

It is seldom that so much change is seen in the gullet and pharynx as

this museum preparation exhibits; but redness, swelling, and the

general signs of inflammation are seldom absent from the stomach and

some parts of the intestines. On the lining membrane of the mouth,

ulcers and pustules have been observed.

In Dr. Nevin’s experiments on the chronic poisoning of rabbits already

referred to, the _post-mortem_ appearances consisted in congestion of

the liver in all the rabbits; in nearly all there was vivid redness of

the stomach; in two cases there was ulceration; in some, cartilaginous

hardness of the pylorus; while, in others, the small intestines

presented patches of inflammation. In two of the rabbits the solitary

glands throughout the intestines were prominent, yellow in colour, and

loaded with antimony. The colon and rectum were healthy, the kidneys

congested; the lungs were in most congested, in some actually inflamed,

or hepatised and gorged with blood. Bloody extravasations in the chest

and abdomen were frequent.

Saikowsky,[811] in feeding animals daily with antimony, found invariably

in the course of fourteen to nineteen days fatty degeneration of the

liver, and sometimes of the kidney and heart. In the experiment of

Caillol and Livon also all the organs were pale, the liver had undergone

fatty degeneration, and the lung had its alveoli filled with large

degenerated cells, consisting almost entirely of fat. The mesenteric

glands also formed large caseous masses, yellowish-white in colour,

which, under the microscope, were seen to be composed of fatty cells, so

that there is a complete analogy between the action of arsenic and

antimony on the body tissues.

[811] Virchow’s _Arch. f. path. Anat._, Bd. xxv.; also, _Centralblatt f.

Med. Wissen._, No. 23, 1865.

§ 760. =Elimination of Antimony.=--Antimony is mainly eliminated by the

urine. In 1840, Orfila showed to the _Académie de Médecine_ metallic

antimony, which he had extracted from a patient who had taken ·12 grm.

of tartar emetic in twenty-four hours. He also obtained antimony from an

old woman, aged 80, who twelve hours before had taken ·6 grm. (9¼

grains)--a large dose, which had neither produced vomiting nor purging.

In Dr. Kevin’s experiments on rabbits, antimony was discovered in the

urine after the twelfth dose, and even in the urine of an animal

twenty-one days after the administration of the poison had been

suspended.

§ 761. =Antidotes for Tartar Emetic.=--Any infusion containing tannin or

allied astringent principles, such as decoctions of tea, oak-bark, &c.,

may be given with advantage in cases of recent poisoning by tartar

emetic, for any of the salt which has been expelled by vomiting may in

this way be decomposed and rendered harmless. The treatment of acute

poisoning which has proved most successful, has been the encouraging of

vomiting by tickling the fauces, giving strong green tea and stimulants.

(See Appendix.)

§ 762. =Effects of Chloride or Butter of Antimony.=--Only a few cases of

poisoning by butter of antimony are on record: its action, generally

speaking, on the tissues is like that of an acid, but there has been

considerable variety in the symptoms. Five cases are recorded by Taylor;

three of the number recovered after taking respectively doses of 7·7

grms. (2 drachms) and 15·5 grms. (4 drachms), and two died after taking

from 56·6 to 113 grms. (2 to 4 ounces). In one of these cases the

symptoms were more like those of a narcotic poison, in the other fatal

case there was abundant vomiting with purging. The autopsy in the first

case showed a black appearance from the mouth to the jejunum, as if the

parts had been charred, and extensive destruction of the mucous

membrane. In the other case there were similar changes in the stomach

and the upper part of the intestines, but neither the lips nor the lower

end of the gullet were eroded. In a case recorded by Mr. Barrington

Cooke,[812] a farmer’s wife, aged 40, of unsound mind, managed to elude

the watchfulness of her friends, and swallowed an unknown quantity of

antimony chloride about 1.30 P.M. Shortly afterwards she vomited several

times, and had diarrhœa; at 2.30 a medical man found her lying on her

back insensible, and very livid in the face and neck. She was retching,

and emitting from her mouth a frothy mucous fluid, mixed with ejected

matter of a grumous colour; the breathing was laboured and spasmodic;

the pulse could not be felt, and the body was cold and clammy. She

expired at 3.30, about one hour and a half from the commencement of

symptoms, and probably within two hours from the taking of the poison.

The autopsy showed no corrugation of the tongue or inner surface of the

lining membrane of the mouth, and no appearance of the action of a

corrosive upon the lips, fauces, or mucous membrane of the œsophagus.

The whole of the mucous membrane of the stomach was intensely congested,

of a dark and almost black colour, the rest of the viscera were healthy.

Chemical analysis separated antimony equivalent to nearly a grm. (15

grains) of the chloride, with a small quantity of arsenic, from the

contents of the stomach.

[812] _Lancet_, May 19, 1883.

§ 763. =Detection of Antimony in Organic Matters.=--In acute poisoning

by tartar emetic it is not impossible to find a mere trace only in the

stomach, the greater part having been expelled by vomiting, which nearly

always occurs early, so that the most certain method is, where possible,

to analyse the ejected matters. If it should be suspected that a living

person is being slowly poisoned by antimony, it must be remembered that

the poison is mainly excreted by the kidneys, and the urine should

afford some indication. The readiest way to test is to collect a

considerable quantity of the urine (if necessary, two or three days’

excretion), concentrate by evaporation, acidify, and then transfer the

liquid to a platinum dish, in which is placed a slip of zinc. The whole

of the antimony is in time deposited on the platinum dish, and being

thus concentrated, may be subsequently identified in any way thought

fit.

Organic liquids are boiled with hydrochloric acid; organic solids are

extracted with the same acid in the manner described (p. 51); or, if the

distillation process given at p. 576 be employed, the antimony may be

found partly in the distillate, and partly in the retort. In any case,

antimony in solution may be readily detected in a variety of ways--one

of the most convenient being to concentrate on tin or platinum, to

dissolve out the antimonial film by sulphide of ammonium, and thus

produce the very characteristic orange sulphide.

If a slip of pure tinfoil be suspended for six hours in a solution,

which should not contain more than one-tenth of its bulk of ClH, and

exhibit no stain or deposit, it is certain that antimony cannot be

present. It may also conveniently be deposited on a platinum dish,[813]

by filling the same with the liquid properly acidulated, and inserting a

rod of zinc; the metallic antimony can afterwards be washed, dried, and

weighed.

[813] According to Fresenius (_Zeitschr. f. anal. Chem._, i. 445), a

solution which contains 1/10000 of its weight of antimony, treated in

this way, gives in two minutes a brown stain, and in ten a very notable

and strong dark brown film. When in the proportion of 1 to 20,000, the

reaction begins to be certain after a quarter of an hour; with greater

dilution it requires longer time, 1 to 40,000 giving a doubtful

reaction, and 1 to 50,000 not responding at all to this test.

Reinsch’s and Marsh’s tests have been already described (pp. 558 and

559), and require no further notice. There is, however, a very beautiful

and delicate means of detecting antimony, which should not be omitted.

It is based upon the action of stibine (SbH₃) on sulphur.[814] When this

gas is passed over sulphur, it is decomposed according to equation,

2SbH₃ + 6S = Sb₂S₃ + 3SH₂, the action taking place slowly in diffused

daylight, but very rapidly in sunshine. An ordinary flask for the

evolution of hydrogen (either by galvanic processes or from zinc and

sulphuric acid), with its funnel and drying-tubes, is connected with a

narrow tube having a few fragments of sulphur, kept in place by plugs of

cotton wool. The whole apparatus is placed in sunshine; if no orange

colour is produced when the hydrogen has been passing for some time, the

liquid to be tested is poured in gradually through the funnel, and if

antimony should be present, the sulphur acquires a deep orange colour.

This is distinct even when so small a quantity as ·0001 grain has been

added through the funnel. The sulphide of antimony thus mixed with

sulphur can, if it is thought necessary, be freed from the sulphur by

repeated exhaustion with bisulphide of carbon. The stibine does not,

however, represent all the antimony introduced, a very large proportion

remaining in the evolution flask;[815] hence it cannot be employed for

quantitative purposes. Moreover, the test can, of course, only be

conveniently applied on sunny days, and is, therefore, in England more

adapted for summer.[816] Often, however, as mentioned elsewhere, when

the analyst has no clue whatever to the nature of the poison, it is

convenient to pass SH₂ in the liquid to saturation.[817] In such a case,

if antimony is present (either alone or in combination with other

sulphides), it remains on the filter, and must be separated and

identified as follows:--The sulphides are first treated with a solution

of carbonate of ammonia, which will dissolve arsenic, if present, and

next saturated _in situ_ with pure sulphide of sodium, which will

dissolve out sulphide of antimony, if present. The sulphide of antimony

will present the chemical characters already described, more

particularly--

[814] See Ernest Jones on “Stibine,” _Journ. Chem. Soc._, vol. i., 1876.

[815] Rieckter, _Jahresbericht_, 1865, p. 255.

[816] The action of salts of cæsium with chloride of antimony might be

used as a test for the latter. A salt of cæsium gives a white

precipitate with chloride of antimony in concentrated ClH; it contains

30·531 per cent. of antimony, and corresponds to the formula SbCl₃CsCl.

Chloride of tin acts similarly.--E. Godeffroy, _Berichte der deutschen

Chem. Gesellschaft_, Berlin, 1874.

[817] The solution must not be too acid.

(1) It will evolve SH₂ when treated with HCl, and at the same time pass

into solution.[818]

[818] By adding chloride of tin to a solution of chloride of antimony in

sufficient quantity, and passing SO₂ through the liquid, the whole of

the antimony can be thrown down as sulphide, whilst the tin remains in

solution. Thus,--

9SnCl₂ + 2SbCl₃ + 3SO₂ + 12ClH = Sb₂S₃ + 9SnCl₄ + 6OH₂.

--Federow, _Zeitschrift für Chemie_, 1869, p. 16.

(2) The solution evaporated to get rid of free HCl gives with water a

thick cheesy precipitate of basic chloride of antimony. This may be seen

if only a drop or two of the solution be taken and tested in a

watch-glass.

(3) If tartaric acid be added to the solution, this precipitation does

not occur.

(4) The solution from (3) gives an orange precipitate with SH₂.

Such a substance can only be sulphide of antimony. With regard to (2),

bismuth would act similarly, but under the circumstances could not be

present, for the sulphide of bismuth is insoluble in sodic sulphide.

§ 764. =Quantitative Estimation.=--The quantitative estimation of

antimony is best made by some volumetric process, _e.g._, the sulphide

can be dissolved in HCl, some tartrate of soda added, and then carbonate

of soda to weak alkaline reaction. The strength of the solution of

tartarised antimony thus obtained can now be estimated by a decinormal

solution of iodine, the end reaction being indicated by the previous

addition of a little starch solution, or by a solution of permanganate

of potash, either of which should be standardised by the aid of a

solution of tartar emetic of known strength.

3. CADMIUM.

§ 765. =Cadmium=, Cd = 112; specific gravity, 8·6 to 8·69;

fusing-point, 227·8° (442° F.); boiling-point, 860° (1580°

F.).--Cadmium in analysis is seldom separated as a metal, but is

estimated either as oxide or sulphide.

§ 766. =Cadmium Oxide=, CdO = 128--cadmium, 87·5 per cent.; oxygen,

12·5 per cent.--is a yellowish or reddish-brown powder, non-volatile

even at a white heat; insoluble in water, but dissolving in acids.

Ignited on charcoal, it is reduced to metal, which volatilises, and

is then deposited again as oxide, giving to the coal a distinct coat

of an orange-yellow colour in very thin layers; in thicker layers,

brown.

§ 767. =Cadmium Sulphide=, CdS = 144--Cd, 77·7 per cent.; S, 22·3

per cent.--known as a mineral termed Greenockite. When prepared in

the wet way, it is a lemon-yellow powder, which cannot be ignited in

hydrogen without loss, and is insoluble in water, dilute acids,

alkalies, alkaline sulphides, sulphate of soda, and cyanide of

potassium. The solution must not contain too much hydrochloric acid,

for the sulphide is readily soluble with separation of sulphur in

concentrated hydrochloric acid. It may be dried in the ordinary way

at 100° without suffering any decomposition.

§ 768. =Medicinal Preparations.=--_The Iodide of Cadmium_ (CdI₂)

occurs in white, flat, micaceous crystals, melting at about 215·5°

(419·9° F.), and at a dull red heat giving off violet vapour. In

solution, the salt gives the reactions of iodine and cadmium. The

ointment of iodide of cadmium (_Unguentum cadmii iodidi_) contains

the iodide in the proportion of 62 grains to the ounce, or 14 per

cent.

=Cadmium Sulphate= is officinal in the Belgian, Portuguese, and

French pharmacopœias.

§ 769. =Cadmium in the Arts, &c.=--Cadmium is used in various

alloys. The sulphide is found as a colouring ingredient in certain

toilet soaps, and it is much valued by artists as a pigment. The

iodide of cadmium is employed in photography, and an amalgam of

metallic cadmium to some extent in dentistry.

§ 770. =Fatal Dose of Cadmium.=--Although no deaths from the use of

cadmium appear to have as yet occurred, its use in photography, &c.,

may lead to accidents. There can be no question about the poisonous

action of cadmium, for Marmé,[819] in his experiments on it with

animals, observed giddiness, vomiting, syncope, difficulty in

respiration, loss of consciousness, and cramps. The amount necessary

to destroy life can only be gathered from the experiments on

animals. A strong hound died after the injection of ·03 grm. (·462

grain) subcutaneously of a salt of cadmium; rabbits are poisoned if

from 19·4 to 38·8 mgrms. (·3 to ·6 grain) are introduced into the

stomach. A watery solution of ·5 grm. (7·5 grains) of the bromide

administered to a pigeon caused instant death, without convulsion;

the same dose of the chloride killed a second pigeon in six minutes;

·25 grm. (3·85 grains) of sulphite of cadmium administered to a

pigeon excited vomiting, and after two hours diarrhœa; it died in

eight days. Another pigeon died from a similar dose in fourteen

days, and cadmium, on analysis, was separated from the liver. From

the above cases it would seem probable that 4 grms. (61·7 grains)

would be a _dangerous_ dose of a soluble salt of cadmium for an

adult, and that in a case of chronic poisoning it would most

probably be found in the liver.

[819] _Zeitschr. f. rationelle Med._, vol. xxix. p. 1, 1867.

§ 771. =Separation and Detection of Cadmium.=--If cadmium be in

solution, and the solution is not too acid, on the addition of SH₂

there is precipitated a yellow sulphide, which is distinguished

from antimony and arsenical sulphides by its insolubility in ammonia

and alkaline sulphides. Should all three sulphides be on the filter

(an occurrence which will seldom, perhaps never, happen), the

sulphide of arsenic can be dissolved out by ammonia, the antimony by

sulphide of sodium, leaving the sulphide of cadmium as the

residue.[820]

[820] It is unnecessary to state that absence of sulphur is presupposed.

The further tests of the sulphide are:--

(1) It dissolves in dilute nitric acid to a colourless fluid, with

separation of sulphur.

(2) The solution, filtered and freed from excess of nitric acid by

evaporation, gives with a solution of ammonic carbonate a white

precipitate of carbonate of cadmium insoluble in excess. This

distinguishes it from zinc, which gives a similar white precipitate,

but is soluble in the excess of the precipitant.

(3) The carbonate thus obtained, heated on platinum foil, is changed

into the brown-red non-volatile oxide.

(4) The oxide behaves on charcoal as already detailed.

(5) A metallic portion can be obtained by melting the oxide with

cyanide of potassium; it is between zinc and tin in brilliancy, and

makes a mark on paper like lead, but not so readily. There are many

other tests, but the above are conclusive.

If cadmium in any case be specially searched for in the organs or

tissues, the latter should be boiled with nitric acid. The acid

solution is filtered, saturated with caustic potash, evaporated to

dryness, and ignited; the residue is dissolved in dilute

hydrochloric acid, and treated after filtration with SH₂. Cadmium

may also be estimated volumetrically by digesting the sulphide in a

stoppered flask with ferric chloride and hydrochloric acid; the

resulting ferrous compound is titrated with permanganate, each c.c.

of a d.n. solution of permanganate = ·0056 grm. of cadmium.

II.--PRECIPITATED BY HYDRIC SULPHIDE IN HYDROCHLORIC ACID

SOLUTION--BLACK.

Lead--Copper--Bismuth--Silver--Mercury.

1. LEAD.

§ 772. =Lead=, Pb = 207.--Lead is a well-known bluish-white, soft metal;

fusing-point, 325°; specific gravity, 11·36.

=Oxides of Lead.=--The two oxides of lead necessary to notice here

briefly are--litharge and minium.

=Litharge, or Oxide of Lead=, PbO = 223; specific gravity, 9·2 to

9·5--Pb 92·82 per cent., O 7·18--is either in crystalline scales, a

fused mass, or a powder, varying in colour (according to its mode of

preparation) from yellow to reddish-yellow or orange. When prepared

below the temperature of fusion it is called “_massicot_.” It may be

fused without alteration in weight; in a state of fusion it dissolves

silicic acid and silicates of the earths. It must not be fused in

platinum vessels.

=Minium, or Red Lead=, 2PbO, PbO₂; specific gravity, 9·08, is a compound

of protoxide of lead with the dioxide. It is of a brilliant red colour,

much used in the arts, and especially in the preparation of flint-glass.

§ 773. =Sulphide of Lead=, PbS = 239; Pb, 86·61 per cent., S, 13·39 per

cent., occurring in the usual way, is a black precipitate insoluble in

water, dilute acids, alkalies, and alkaline sulphides. It dissolves in

strong nitric acid with separation of sulphur, and in strong

hydrochloric acid, with evolution of SH₂. Fuming nitric acid does not

separate sulphur, but converts the sulphide into sulphate.

§ 774. =Sulphate of Lead=, PbSO₄ = 303; specific gravity, 6·3; PbO,

73·61 per cent., SO₃, 26·39 per cent., when produced artificially is a

heavy white powder, of great insolubility in water, 22,800 parts of cold

water dissolving only one of lead sulphate; and if the water contains

sulphuric acid, no less than 36,500 parts of water are required. The

salts of ammonia (especially the acetate and tartrate) dissolve the

sulphate, and it is also soluble in hyposulphite of soda. The sulphate

can be readily changed into the carbonate of lead, by boiling it with

solutions of the alkaline carbonates. The sulphate of lead, fused with

cyanide of potassium, yields metallic lead; it may be also reduced on

charcoal, and alone it may be fused without decomposition, provided

reducing gases are excluded.

§ 775. =Acetate of Lead=, =Sugar of Lead=, Pb(C₂H₃O₂)₂3OH₂ = 379, is

found in commerce in white, spongy masses composed of acicular crystals.

It may, however, be obtained in flat four-sided prisms. It has a sweet

metallic taste, is soluble in water, and responds to the usual tests for

lead. The P.B. directs that 38 grains dissolved in water require, for

complete precipitation, 200 grain measures of the volumetric solution of

oxalic acid, corresponding to 22·3 grains of oxide of lead.

§ 776. =Chloride of Lead=, PbCl₂ = 278; specific gravity, 5·8; Pb, 74·48

per cent., Cl, 25·52 per cent., is in the form of brilliant crystalline

needles. It is very insoluble in cold water containing hydrochloric or

nitric acids. According to Bischof, 1635 parts of water containing

nitric acid dissolve one part only of chloride of lead. It is insoluble

in absolute alcohol, and sparingly in alcohol of 70 to 80 per cent. It

fuses below red heat without losing weight; at higher temperatures it

may be decomposed.

=Carbonate of Lead.=--The commercial carbonate of lead (according to the

exhaustive researches of Wigner and Harland[821]) is composed of a

mixture of neutral carbonate of lead and hydrate of lead, the best

mixture being 25 per cent. of hydrate, corresponding to an actual

percentage of 12·3 per cent. carbonic acid. The nearer the mixture

approximates to this composition the better the paint; whilst samples

containing as much as 16·33 per cent., or as little as 10·39 per cent.,

of CO₂ are practically useless.

[821] “On the Composition of Commercial Samples of White Lead,” by G. W.

Wigner and R. H. Harland.--_Analyst_, 1877, p. 208.

§ 777. =Preparations of Lead used in Medicine, the Arts, &c.=

(1) =Pharmaceutical=:--

=Lead Plaster= (_Emplastrum plumbi_) is simply a lead soap, in which the

lead is combined with oleic and margaric acids, and contains some

mechanically included glycerin.

=Lead Iodide=, PbI₂, is contained in the _Emplastrum plumbi iodidi_ to

the extent of 10 per cent., and in the _Unguentum plumbi iodidi_ to the

extent of about 12·5 per cent.

=Acetate of Lead= is contained in a pill, a suppository, and an

ointment. The pill (_Pilula plumbi cum opio_) contains 75 per cent. of

lead acetate, and 12·5 per cent. of opium, the rest confection of roses.

The suppository (_Suppositoria plumbi composita_) contains 20 per cent.

of acetate of lead, and 6·6 per cent. of opium, mixed with oil of

theobroma. The ointment (_Unguentum plumbi acetatis_) contains 20·6 per

cent. of lead acetate, mixed with benzoated lard.

The solution of subacetate of lead (_Liquor plumbi subacetatis_) is the

subacetate, Pb(C₂H₃O₂)₂PbO, dissolved in water; it contains nearly 27

per cent. of subacetate.

A dilute solution of the stronger, under the name of _Liquor plumbi

subacetatis dilutus_, and commonly called Goulard water, is prepared by

mixing 1 part (by volume) of the solution and 1 part of spirit, and 78

parts of distilled water; the strength is equal to 1·25 per cent.

There is an ointment, called the _Compound Ointment of subacetate of

lead_, which contains the subacetate in about the proportion of 2 per

cent. of the oxide, the other constituents being camphor, white wax, and

almond oil.

=Carbonate of Lead.=--The ointment (_Unguentum plumbi carbonatis_)

should contain about 12·5 per cent. of the carbonate, and the rest

simple ointment.

(2) =Quack Nostrums, &c.=:--

The quack medicines composed of lead are not very numerous.

Liebert’s =Cosmetique Infaillible= is said to have for its basis

nitrate of lead.

One of “=Ali Ahmed’s Treasures of the Desert=,” viz., the antiseptic

malagma, is a plaster made up of lead plaster 37·5 per cent.,

frankincense 25 per cent., salad oil 25 per cent., beeswax 12·5 per

cent.

=Lewis’ Silver Cream= contains white precipitate and a salt of lead.

=Goulard’s Balsam= is made by triturating acetate of lead with hot

oil of turpentine.

There are various ointments in use made up of litharge. Some

herbalists in the country (from cases that have come under the

writer’s own knowledge) apply to cancerous ulcers, &c., a liniment

of linseed and other common oils mixed with litharge and acetate of

lead.

Acetate of lead may also be found as a constituent of various

eye-waters.

(3) =Preparations of Lead used in the Arts, &c.=:--

=Ledoyen’s Disinfecting Fluid= has for its basis nitrate of lead.

In various hair-dyes the following are all used:--Litharge, lime,

and starch; lime and carbonate of lead; lime and acetate of lead;

litharge, lime, and potassic bicarbonate. The detection of lead in

the hair thus treated is extremely easy; it may be dissolved out by

dilute nitric acid.

=Lead Pigments.=--The principal pigments of lead are white, yellow,

and red.

=White Pigments=:--

=White Lead=, =Flake White Ceruse=, =Mineral White=, are so many

different names for the carbonate of lead already described.

=Newcastle White= is white lead made with molasses vinegar.

=Nottingham White.=--White lead made with alegar (sour ale), often,

however, replaced by permanent white, _i.e._, sulphate of baryta.

=Miniature Painters’ White=, =White Precipitate of Lead=, is simply

lead sulphate.

=Pattison’s White= is an oxychloride of lead, PbCl₂PbO.

=Yellow Pigments=:--

=Chrome Yellow= may be a fairly pure chromate of lead, or it may be

mixed with sulphates of lead, barium, and calcium. The pigment known

as “Cologne yellow” consists of 25 parts of lead chromate, 15 of

lead sulphate, and 60 of calcic sulphate. The easiest method of

analysing chrome yellow is to extract with boiling hydrochloric acid

in the presence of alcohol, which dissolves the chromium as

chloride, and leaves undissolved chloride of lead, sulphate of lead,

and other substances insoluble in ClH. Every grain of chromate of

lead should yield 0·24 grain of oxide of chromium, and 0·4 grain of

chloride of lead.

=Turner’s Yellow=, =Cassella Yellow=, =Patent Yellow=, is an

oxychloride of lead (PbCl₂7PbO) extremely fusible.

=Dutch Pink= sometimes contains white lead.

=Red Pigments=:--

=Chrome Red= is a bichromate of lead.

=Red Lead= or =Minium= is the red oxide of lead.

=Orange Red= is an oxide prepared by calcining the carbonate.

The chief preparations of lead which may be met with in the arts, in

addition to the oxides and the carbonate, are--

The =Nitrate of Lead=, much used in calico-printing.

The =Pyrolignite of Lead=, which is an impure acetate used in

dyeing; and

The =Sulphate of Lead= is a by-product in the preparation of acetate

of aluminium for dyeing.

The alloys containing lead are extremely numerous; but, according to

the experiments of Knapp,[822] the small quantity of lead in those

used for household purposes has no hygienic importance.

[822] _Dingl. Polytech. Journ._, vol. ccxx. pp. 446-453.

§ 778. =Statistics of Lead-Poisoning.=--In the ten years, 1883 to 1892,

no less than 1043 persons died from the effects of lead; of these, 3

only were suicidal, the remaining 1040 were mainly from the manufacture

of white lead or from the use of lead in the arts or from the accidental

contamination of food or drink.

The following table shows in what manner the 1040 were distributed as to

age and sex:--

DEATHS FROM LEAD-POISONING IN ENGLAND AND WALES DURING THE TEN YEARS

1883-1892.

Ages, 0-1 1-5 5-15 15-25 25-65 65 and Total

above

Males, ... 4 14 44 733 36 831

Females, 3 5 ... 68 129 4 209

---------------------------------------------

Total, 3 9 14 112 862 40 1040

---------------------------------------------

§ 779. =Lead as a Poison.=--All the compounds of lead are said to be

poisonous; but this statement cannot be regarded as entirely correct,

for the sulphocyanide has been proved by experiment not to be so,[823]

and the sulphide is also probably inactive. In the treatment of cases of

lead-poisoning, the flowers of sulphur given internally appear to be

successful.[824]

[823] Eulenberg, _Gewerbe Hygiene_, p. 712.

[824] Mohr’s _Toxicologie_, p. 78.

Lead-poisoning, either in its obscure form (producing uric acid in the

blood, and, as a consequence, indigestion and other evils), or in the

acute form (as lead colic and various nervous affections), is most

frequent among those who are habitually exposed to the influence of the

metal in its different preparations, viz., workers of lead,

house-painters, artists, gilders, workers of arsenic, workers of gold,

calico-printers, colourists, type-founders, type-setters, shot-founders,

potters, faience makers, braziers, and many others.[825] In white-lead

factories so large a number of the employés suffer from poisoning that

it has excited more than once the attention of the Government.[826]

[825] The attention which the use of lead in the arts has always excited

is evident from the fact that one of the oldest works on Trade Hygiene

(by Stockhausen) is entitled, _De lithargyrii fumo noxio, morbifico

ejusque metallico frequentiori morbo vulgo dicto hüttenkatze_, Gaslar,

1556.

[826] A departmental committee, appointed to inquire into the white lead

and allied industries, in a report presented to the Home Secretary

stated:--

“8. (_a_) It is known that if lead (in any form), even in what may be

called infinitesimal quantities, gains entrance into the system for a

lengthened period, by such channels as the stomach, by swallowing lead

dust in the saliva, or through the medium of food and drink; by the

respiratory organs, as by the inhalation of dust; or through the skin;

there is developed a series of symptoms, the most frequent of which is

colic. Nearly all the individuals engaged in factories where lead or its

compounds are manipulated look pale, and it is this bloodlessness and

the presence of a blue line along the margin of the gums, close to the

teeth, that herald the other symptoms of plumbism. (_b_) A form of

paralysis known as wrist-drop or lead-palsy occasionally affects the

hands of the operatives. There is, in addition, a form of acute

lead-poisoning, most frequently met with in young girls from 18 to 24

years of age, which is suddenly developed and is extremely fatal. In it

the first complaint is headache, followed sooner or later by convulsions

and unconsciousness. Death often terminates such a case within three

days. In some cases of recovery from convulsions total blindness

remains.

“9. There has been considerable doubt as to the channels by which the

poison enters the system. The committee have taken much evidence on this

subject, and have arrived at the conclusion (_a_) that carbonate of lead

may be absorbed through the pores of the skin, and that the chance of

this is much increased during perspiration and where there is any

friction between the skin and the clothing; (_b_) that minute portions

of lead are carried by the hands, under and round the nails, &c., on to

the food, and so into the stomach; (_c_) but that the most usual manner

is by the inhalation of lead dust. Some of this becomes dissolved in the

alkaline secretions of the mouth, and is swallowed by the saliva, thus

finding its way to the stomach. Other particles of dust are carried to

the lungs, where they are rendered soluble and absorbed by the

blood.”--_Report of Chief Inspector of Factories for 1893._

Lead, again, has been found by the analyst in most of the ordinary

foods, such as flour, bread, beer, cider, wines, spirits, tea, vinegar,

sugar, confectionery, &c., as well as in numerous drugs, especially

those manufactured by the aid of sulphuric acid (the latter nearly

always containing lead), and those salts or chemical products which

(like citric and tartaric acids) are crystallised in leaden pans. Hence

it follows that in almost everything eaten or drunk the analyst, as a

matter of routine, tests for lead. The channels through which it may

enter into the system are, however, so perfectly familiar to practical

chemists, that a few _unusual_ instances of lead-poisoning only need be

quoted here.

A cabman suffered from lead colic, traced to his taking the first glass

of beer every morning at a certain public-house; the beer standing in

the pipes all night, as proved by analysis, was strongly impregnated

with lead.[827]

[827] _Chem. News._

The employment of red lead for repairing the joints of steam pipes has

before now caused poisonous symptoms from volatilisation of lead.[828]

The use of old painted wood in a baker’s oven, and subsequent adherence

of the oxide of lead to the outside of the loaves, has caused the

illness of sixty-six people.[829]

[828] Eulenberg, _Op. cit._, p. 708.

[829] _Annales d’Hygiène._

Seven persons became affected with lead-poisoning through horse-hair

coloured with lead.[830]

[830] Hitzig, _Studien über Bleivergiftung_.

The manufacture of _American overland cloth_ creates a white-lead dust,

which has caused serious symptoms among the workmen (_Dr. G. Johnson_).

The cleaning of pewter pots,[831] the handling of vulcanised

rubber,[832] the wrapping up of various foods in tinfoil,[833] and the

fingering of lead counters covered with brine by fishmongers, have all

caused accidents in men.

[831] _Med. Gazette_, xlviij. 1047.

[832] _Pharm. Journ._, 1870, p. 426.

[833] Taylor, _Prin. Med. Jurisprud._, i.

The lead in glass, though in the form of an insoluble silicate, is said

to have been dissolved by vinegar and other acid fluids to a dangerous

extent. This, however, is hardly well established.[834]

[834] See _Aerztl. Intelligenzbl. f. Baiern_, Jahrg., 1869; _Buchner’s

Rep. Pharm._, Bd. xix. p. 1; _Med. Centrbl._, Jahrg., 1869, p. 40.

§ 780. =Effects of Lead Compounds on Animals.=--Orfila and the older

school of toxicologists made a number of experiments on the action of

sugar of lead and other compounds, but they are of little value for

elucidating the physiological or toxic action of lead, because they

were, for the most part, made under unnatural conditions, the gullet

being ligatured to avoid expulsion of the salt by vomiting. Harnack, in

order to avoid the local and corrosive effects of sugar of lead, used an

organic compound, viz., plumbic triethyl acetate, which has no local

action. Frogs exhibited symptoms after subcutaneous doses of from 2 to

3 mgrms., rabbits after 40 mgrms.; there was increased peristaltic

action of the intestines, with spasmodic contraction rising to colic,

very often diarrhœa, and death followed through heart paralysis. Dogs

given the ethyl compound exhibited nervous symptoms like chorea.

Gusserno[835] has also made experiments on animals as to the effects of

lead, using lead phosphate, and giving from 1·2 grm. to a rabbit and a

dog daily. Rosenstein[836] and Heubel[837] used small doses of acetate,

the latter giving dogs daily from ·2 to ·5 grm. The results arrived at

by Gusserno were, mainly, that the animals became emaciated, shivered,

and had some paralysis of the hinder extremities; while Rosenstein

observed towards the end epileptiform convulsions, and Heubel alone saw,

in a few of his cases, colic. A considerable number of cattle have been

poisoned from time to time with lead, and one instance of this fell

under my own observation. A pasture had been manured with refuse from a

plumber’s yard, and pieces of paint were in this way strewn about the

field in every direction; a herd of fifteen young cattle were placed in

the field, and in two or three days they all, without exception, began

rapidly to lose condition, and to show peculiar symptoms--diarrhœa, loss

of appetite; in two, blindness, the retina presenting an appearance not

unlike that seen in Bright’s disease; in three, a sort of delirium. Four

died, and showed on _post-mortem_ examination granular conditions of the

kidneys, which was the most striking change observable. In the fatal

cases, paralysis of the hind extremities, coma, and convulsions preceded

death. In another case[838] seven cows and a bull died from eating lead

paint; the symptoms were loss of appetite, obstinate constipation,

suspension of rumination, dry muffle, quick breathing, and coma. In

other cases a marked symptom has been paralysis. Cattle[839] have also

several times been poisoned from eating grass which has been splashed by

the spray from bullets, as in pastures in the vicinity of rifle butts;

here we must allow that the intestinal juices have dissolved the metal,

and transformed it into compounds capable of being taken into the

system.

[835] Virchow’s _Archiv. f. path. Anat._, vol. xxi. p. 443.

[836] _Ib._, vol. xxxix. pp. 1 and 74.

[837] _Pathogenese u. Symptome der chronischen Bleivergiftung_, Berlin,

1871.

[838] See a paper by Professor Tuson, _Veterinarian_, vol. xxxviii.,

1861.

[839] _Ib._; also Taylor, _Op. cit._

§ 781. =Effects of Lead Compounds on Man--Acute Poisoning.=--Acute

poisoning by preparations of lead is not common, and, when it does

occur, is seldom fatal. With regard to the common acetate, it would seem

that a large single dose is less likely to destroy life than smaller

quantities given in divided doses for a considerable period. The

symptoms produced by a considerable dose of sugar of lead usually

commence within a few minutes; there is immediately a metallic taste,

with burning, and a sensation of great dryness in the mouth and throat;

vomiting, which occurs usually within fifteen minutes, is in very rare

cases delayed from one to two hours. The retching and vomiting are very

obstinate, and continue for a long time; the matters thrown up are

sometimes streaked with blood; there is pain in the abdomen of a colicky

character--a pain relieved by pressure. The bowels are, as a rule,

constipated, but occasionally relaxed. The stools at a later date are

black from the presence of lead sulphide. The urine, as a rule, is

diminished. The breath has a foul odour, and the tongue is coated; the

skin is dry, and the pulse small and frequent. The full development of

the toxic action is completed by the appearance of various nervous

phenomena--headache, shooting pains in the limbs, cramps in the legs,

and local numbness. All the symptoms enumerated are not present in each

case; the most constant are the vomiting and the colic. If the sufferer

is to die, death occurs about the second or third day. If the patient

recovers, convalescence may be much retarded, as shown in the case of

two girls,[840] who had each swallowed an ounce of lead acetate by

mistake, and who suffered even after the lapse of a year from pain and

tenderness in the stomach and sickness.

[840] Prov. _Med. Journal_, 1846.

There are “mass-poisonings” by acetate of lead on record, which afford

considerable insight into the varying action of this salt on different

individuals. A case (_e.g._) occurred at Stourbridge in 1840,[841] in

which no less than 500 people were poisoned by thirty pounds of lead

acetate being accidentally mixed with eighty sacks of flour at a

miller’s. The symptoms commenced after a few days; constriction of the

throat, cramping and twisting pains round the umbilicus, rigidity of the

abdominal muscles, dragging pains at the loins, cramps and paralysis of

the lower extremities. There was obstinate constipation; the urine was

scanty and of a deep red colour, and the secretions were generally

arrested; the pulse was slow and feeble; the countenance depressed,

often livid; and the gums showed the usual blue line. The temperature of

the skin was low. In only a few cases was there sickness, and in these

it soon ceased. It is curious that not one of the 500 cases proved

fatal, although some of the victims were extremely ill, and their

condition alarming. It was specially observed that, after apparent

convalescence, the symptoms, without any obvious cause, suddenly

returned, and this even in a more aggravated form. Remittance of this

kind is of medico-legal import; it might, for example, be wrongly

inferred that a fresh dose had been taken. In the 500 cases there were

no inflammatory symptoms; complete recovery took some time. On examining

the bread the poison was found so unequally distributed that no idea

could be formed as to the actual amount taken.

[841] Recorded by Mr. Bancks, _Lancet_, May 5, 1849, p. 478.

There is also recorded[842] an outbreak of lead-poisoning among 150 men

of the 7th Infantry at Tione, in the Southern Tyrol. One case proved

fatal, forty-five required treatment in hospital. The symptoms were

pallor, a blue line in the gums, metallic taste in the mouth, a peculiar

odour of the breath, a loaded tongue with a bluish tint, obstinate

constipation with loss of appetite whilst all complained, in addition,

of dragging of the limbs and of the muscles of the chest, and difficulty

of breathing. In the severer cases there were tetanic spasms, muscular

tremors, and anæsthesia of the fingers and toes. The pulse and

temperature were normal, save in a few cases in which there were fever

and sweats at night. _In none was there colic_, but the constipation was

obstinate. In two of the worst cases there was strangury. Acute cases

occur occasionally from poisoning by _the carbonate of lead_. Dr. Snow

recorded an instance (in 1844) of a child who had eaten a piece as big

as a marble, ground up with oil. For three days the child suffered from

pain in the abdomen and vomiting, and died ninety hours after taking the

poison. In another case, in which a young man took from 19 to 20 grms.

of lead carbonate in mistake for chalk as a remedy for heartburn, the

symptoms of vomiting, pain in the stomach, &c., commenced after a few

hours; but, under treatment with magnesic sulphate, he recovered.

[842] Königschmied, _Centralbl. Allg. für Gesundheitspflege_, 2 Jahrg.,

Heft 1.

=The chromate of lead= is still more poisonous (see Art. “Chromium”).

§ 782. =Chronic Poisoning by Lead.=--Chronic poisoning by lead--often

caused by strange and unsuspected channels, more frequently an incident,

nay, almost a necessity, of certain trades, and occasionally induced by

a cunning criminal for the purpose of simulating natural disease--is of

great toxicological and hygienic importance. In the white-lead trade it

is, as might be expected, most frequently witnessed; but also in all

occupations which involve the daily use of lead in almost any shape. The

chief signs of chronic poisoning are those of general ill-health; the

digestion is disturbed, the appetite lessened, the bowels obstinately

confined, the skin assumes a peculiar yellowish hue, and sometimes the

sufferer is jaundiced. The gums show a black line from two to three

lines in breadth, which microscopical examination and chemical tests

alike show to be composed of sulphide of lead; occasionally the teeth

turn black.[843] The pulse is slow, and all secretions are diminished.

Pregnant women have a tendency to abort. There are also special

symptoms, one of the most prominent of which is often lead colic.

[843] The black line soon develops; Masazza has seen it in a dog,

exposed to the influence of lead, in so short a period as three days

(_Riforma med._, 1889, Nos. 248-257, 1).

In 142 cases of lead-poisoning, treated between 1852 and 1862 at the

Jacob’s Hospital, Leipzig, forty-four patients (or about 31 per cent.)

suffered from colic. Arthralgia--that is, pains in the joints--is also

very common; it seldom occurs alone, but in combination with other

symptoms. Thus, in seventy-five cases of lead-arthralgia treated at

Jacob’s Hospital, in only seven were pain in the joints without other

complications, fifty-six being accompanied by colic, five by paralysis,

and seven by other affections of the nervous system. The total

percentage of cases of lead-poisoning, in which arthralgia occurs,

varies from 32 to 57 per cent.

Paralysis, in some form or other, Tanqueril[844] found in 5 to 8 per

cent. of the cases, and noticed that it occurred as early as the third

day after working in lead. The muscles affected are usually those of the

upper extremity, then the legs, and still more rarely the muscles of the

trunk. It is only exceptionally that the paralysis extends over an

entire limb; it more usually affects a muscular group, or even a single

muscle. Its common seat is the extensors of the hand and fingers; hence

the expression “dropped-wrist,” for the hands droop, and occasionally

the triceps and the deltoid are affected. The paralysis is usually

symmetrical on both sides. Although the extensors are affected most, the

flexors nearly always participate, and a careful investigation will show

that they are weakened. If the paralysis continues, there is a wasting

and degeneration of the muscle, but this is seen in paralysis from any

cause. The muscular affection may cause deformities in the hands,

shoulders, &c. Anæsthesia of portions of the skin is generally present

in a greater or less degree. A complete analgesia affecting the whole

body has been noticed to such an extent that there was absolute

insensibility to burns or punctures; but it is usually confined to the

right half of the body, and is especially intense in the right hand and

wrist.

[844] Tanqueril des Planches, _Traité des Maladies de Plomb_, Paris,

1839. Tanqueril’s monograph is a classical work full of information.

§ 783. The older writers recognised the toxic effect of lead on the

nervous system. Thus Dioscorides speaks of delirium produced by lead,

Aretaeus of epilepsy, and Paul of Ægina refers to it as a factor of

epilepsy and convulsions. But in 1830, Tanqueril first definitely

described the production of a mental disease, which he called “_lead

encephalopathy_.” This he divided into four forms--(1) a delirious form;

(2) a comatose; (3) a convulsive; and (4) a combined form, comprising

the delirious, convulsive, and comatose. Dr. Henry Rayner,[845] and a

few other English alienists, have directed their attention to this

question; and, according to Dr. Rayner’s researches, the number of male

patients admitted into Hanwell Asylum, engaged in trades such as

plumbing, painting, and the like, is larger in proportion to the number

admitted from other trades than it should be, compared with the

proportion of the various trades in the county of Middlesex, as

ascertained from the census. Putting aside coarse lead-poisoning, which

may occasionally produce acute mania, the insanity produced by prolonged

minute lead intoxications possesses some peculiar features. It develops

slowly, and in nearly all cases there are illusions of the senses, of

hearing, taste, or smell, and especially of sight. Thus, in one of Dr.

Rayner’s cases the patient saw round him “wind-bags blown out to look

like men,” apparitions which made remarks to him, and generally worried

him. Besides this form, there is also another which closely resembles

general paralysis, and, in the absence of the history, might be mistaken

for it.

[845] See an important paper, “Insanity from Lead-Poisoning,” by Drs. H.

Rayner, Robertson, Savage, and Atkins, _Journ. of Mental Science_, vol.

xxvi. p. 222; also a paper by Dr. Barton, _Allgemeine Zeitschrift für

Psychiatrie_, Bd. xxxvij. H. 4, p. 9.

§ 784. The degenerative influence on the organ of sight is shown in six

of Dr. Robertson’s patients, whose insanity was ascribed to lead--four

of the six were either totally or partially blind.

The amaurosis has been known to come on suddenly, and after a very brief

exposure to lead, _e.g._, a man, thirty-four years of age, after working

for three days in a white-lead factory, was seized with intense ciliary

neuralgia, had pains in his limbs and symptoms of lead-poisoning, and

the right eye became amaurotic.[846] This form of impairment or loss of

vision is different from the _Retinitis albuminurica_,[847] which may

also be produced as a secondary effect of the poison; the kidneys in

such cases being profoundly affected. The kind of diseased kidney

produced by lead is the granular contracted kidney.

[846] Samelsohn, _Monatsbl. f. Augenheilk._, vol. xi. p. 246, 1873. See

also a case of lead amaurosis, described by Mr. W. Holder, _Pharm.

Journ._, Oct. 14, 1876.

[847] Ran, _Arch. f. Ophthal._, vol. i. (2), p. 205, 1858, and Schmidt’s

_Jahrbuch_, Bd. cxxxiii. p. 116; Bd. cxliii. p. 67.

Eulenberg speaks of the sexual functions being weakened, leading to more

or less impotence.

Lewy,[848] in 1186 patients suffering from lead-poisoning, has found

caries or necrosis in twenty-two cases, or about 1·8 per cent.; fifteen

were carious affections of the upper jaw, four of the fore-arm, two of

the thigh, and one of the rib and sternum. Epilepsy and epileptiform

convulsions occur in a few cases; it is very possible that the epilepsy

may be a result of the uræmic poisoning induced by diseased kidneys.

[848] _Die Berufskrank. d. Bleiarbeiter_, Wien, 1873, S. 61.

Five cases of fatal poisoning occurred between 1884-6 among the employés

of a certain white-lead factory in the east of London. The cases

presented the following common characters. They were all adult women,

aged from 18 to 33, and they had worked at the factory for short

periods, from three to twelve months. They all exhibited mild symptoms

of plumbism, such as a blue line round the gums, and more or less

ill-defined indisposition; paralyses were absent. They were all in their

usual state of health within a few hours or days preceding death. Death

was unexpected, mostly sudden. In four cases it was preceded by

epileptic fits and coma; but in the fifth case no convulsions were

noted, although they may have occurred in the night.

The author[849] had an opportunity of investigating by chemical means

the distribution of lead in the fourth and fifth cases in the liver,

kidney, and brain.

[849] “The Distribution of Lead in the Brains of two Lead Factory

Operatives,” _Journ. of Mental Science_, Jan. 1888.

In the fourth case, from 402 grms. of liver 24·26 mgrms. of lead

sulphate were separated. The right kidney (weighing 81 grms.) yielded

5·42 mgrms. of lead sulphate. The brain was dehydrated with alcohol, and

then treated with ether, hot alcohol, and chloroform until an albuminoid

residue remained; lead was extracted from each of these portions, viz.,

the alcohol used for dehydration, the ethereal and chloroform extracts,

and the albuminoid residue, as follows:--

Mgrms. of Lead

Sulphate.

Soluble in cold alcohol, 1·11

Soluble in ether and chloroform and hot alcohol, 25·47

Albuminoid residue, 7·76

34·34

In the fifth case, the brain was examined more in detail, and the lead

present estimated in the following solutions and substances:--

1. Alcohol used for dehydration. This may be called “the watery

extract,” for, after the brain has remained in strong alcohol for some

weeks, the result is that the alcohol contains much water and substances

extracted with water.

2. White matter--(_a_) from cerebrum; (_b_) from cerebellum.

3. Kephalin--(_a_) from cerebrum; (_b_) from cerebellum.

4. Ether extract, kephalin-free--(_a_) from cerebrum; (_b_) from

cerebellum.

5. Substances soluble in cold alcohol--(_a_) from cerebrum; (_b_) from

cerebellum.

6. The albuminoid residue--(_a_) from cerebrum; (_b_) from cerebellum.

The general results were as follows:--

Cerebrum, Cerebellum,

460·8 grms. 156·2 grms.

Mgrms. of PbSO₄. Mgrms. of PbSO₄.

White matter freed from kephalin

by ether, 0·0 5·0

Kephalin, 1·5 6·0

Ether extract, kephalin-free, 0·0 0·0

Substances soluble in cold alcohol, 0·0 0·0

Albuminoid residue, 40·0 6·0

---- ----

41·5 17·0

The aqueous extract contained 1·5 mgrm. of lead sulphate. In neither of

the cases did the pathologist ascertain the total weight of the brain,

but, presuming that the weight was an average weight, and that the lead

in the remainder of the brain was similarly distributed, the amount of

lead calculated as sulphate would amount to 117 mgrms. From these

results it appears to the author probable that lead forms a substitution

compound with some of the organic brain matters. This view would explain

the absence of changes apparent to the eye found in so many of the fatal

cases of lead encephalopathy.

§ 785. Lead taken for a long time causes the blood to be impregnated

with uric acid. In 136 cases of undoubted gout, 18 per cent. of the

patients were found to follow lead occupations, and presented signs of

lead impregnation.[850]

[850] “On Lead Impregnation in Relation to Gout,” by Dyce Duckworth,

M.D., _St. Barth. Hosp. Reports_, vol. xvii., 1881.

Ellenberger and Hofmeister[851] found that, with chronic poisoning of

sheep with lead, excretion of hippuric acid ceased, and the output of

uric acid was diminished. This may be explained by the formation of

glycocol being arrested.

[851] _Arch. f. wiss. u. pract. Thierheilk._, Bd. x., 1884.

§ 786. There are some facts on record which would seem to countenance

the belief that disease, primarily caused by an inorganic body like

lead, may be transmitted. M. Paul (_e.g._) has related the history of

the offspring (thirty-two in number) of seven men, who were suffering

from lead-poisoning--eleven were prematurely born and one still-born; of

the remaining twenty, eight died in the first year, four in the second,

and five in the third year, so that of the whole thirty-two, only three

survived three years.

The influence of the poison on pregnant women is, indeed, very

deleterious. M. Paul noted that in four women who were habitually

exposed to the influence of lead, and had fifteen pregnancies, ten

terminated by abortion, two by premature confinement, three went the

full term, but one of the three children was born dead, a second only

lived twenty-four hours; so that, out of the whole fifteen, one only

lived fully. In another observation of M. Paul’s, five women had two

natural confinements before being exposed to lead. After exposure, the

history of the thirty-six pregnancies of these women is as

follows:--there were twenty-six abortions (from two to five months), one

premature confinement, two infants born dead, and five born alive, four

of whom died in the first year.

Chronic poisoning may be nearly always accounted for by the inhaling of

lead dust, or by the actual swallowing of some form of lead; but, if we

are to accept the fact narrated by the late Dr. Taylor, viz., that he

himself had an attack of lead colic from sitting in a room for a few

hours daily, in which there was a large canvas covered with white lead

and drying oil, and one or two other similar cases,[852] we must allow

that there is some subtle volatile organic compound of lead evolved. In

the present state of our knowledge, it seems more reasonable to account

for such cases by the suggestion that lead has entered the system by an

unsuspected channel.

[852] The gate-keeper of a graveyard at Bordeaux continually used the

remnants of crosses, covered with lead paint, to replenish his fire; the

chimney smoked; gradually paralysis of the extensors of the right wrist

developed itself, and he suffered from colic and other signs of

lead-poisoning.--Marmisse, _Gaz. des Hôpit._, No. 25, 1866.

In 1882, a very interesting case occurred at Keighley, in which a

mechanic, aged 42, died from the supposed effects of lead-poisoning,

induced from drinking the town water, which was proved by Mr. Allen to

contain about ⅗ of a grain of lead per gallon. For six months he had

been out of health, and a week before his death he suffered from colic,

vomiting, constipation, and a blue line round the gums, and occasional

epileptiform seizures. After death the kidneys were found granular, and

the heart somewhat enlarged. The viscera were submitted to Mr. Allen for

analysis; no lead was found in the heart or brain, a slight,

non-estimable trace in the kidneys, and about a grain was separated from

the liver and spleen. Dr. Tidy, who was called in as an expert, gave a

very guarded opinion, rather against the theory of direct

lead-poisoning; and the verdict returned by the jury was to the effect

that the deceased died from granular kidney, accelerated by

lead-poisoning. Murder by the administration of doses of sugar of lead

is rare, but such a case has occurred.

At the Central Criminal Court, in December 1882, Louisa Jane Taylor was

indicted for poisoning Mary Ann Tregillis at Plumstead, and convicted.

From the evidence it appeared that the prisoner, who was thirty-six

years of age, came to reside with Mr. and Mrs. Tregillis, an aged couple

of eighty-five and eighty-one years respectively. The prisoner was

proved to have purchased at different times an ounce and half an ounce

of sugar of lead, and to have added a white powder to the medicine of

Mrs. Tregillis. The illness of the latter extended from about August 23

to October 23--a period of two months. It is difficult to say when the

first dose could have been given, but it was probably some time between

August 13 and 23, while the administration, without doubt, ceased on or

before October 6, for on that date different nursing arrangements were

made. The symptoms observed were nausea, vomiting, pain in the pit of

the stomach, burning in the throat, very dark teeth, a blue line round

the gums, and slight jaundice. There was great muscular weakness, with

trembling of the hands, and a week before death there was paralysis of

the right side.

Lead was discovered in most of the viscera, which were in great part

normal, but the kidneys were wasted, and the mucous membrane blackened.

The actual quantity of lead recovered by analysis was small, viz., 16·2

mgrms. (¼ grain) from the liver; from 8 ounces of brain, 3·2 mgrms.

(1/20 grain); from half of the stomach, 16·2 mgrms. (¼ grain); and from

the spleen, the kidneys, and the lungs, small quantities. It is,

therefore, probable that, if the whole body had been operated upon, the

yield would have been more than ·15 grm. (a little over 2 grains); but

then, it must be remembered that the deceased lived, at least, seventeen

days after the last dose.

§ 787. =Post-mortem Appearances.=--In acute cases of poisoning by the

acetate, there may sometimes be found a slight inflammatory appearance

of the mucous membrane of the stomach and intestines. Orfila considered

that streaks of white points adherent to the mucous membrane were

pathognomonic; but there have been several cases in which only negative

or doubtful signs of inflammatory or other action have presented

themselves. A general contraction of the intestines has often been

noticed, and is of considerable significance when present; so also is a

grey-black mucous membrane caused by deposited lead sulphide. Loen found

in dogs and guinea-pigs, poisoned by lead, local inflammation areas in

the lungs, liver, and kidneys; but in no case fatty degeneration of the

epithelial cells of the liver, kidneys, or intestines. As a rule, no

unabsorbed poison will be found in the stomach; the case related by

Christison, in which a person died on the third day after taking at a

single dose some large quantity of acetate of lead; and at the autopsy a

fluid was obtained from the stomach, which had a sweet metallic taste,

on evaporation smelt of acetic acid, and from which metallic lead was

obtained--is so very extraordinary in every respect, that its entire

accuracy is to be questioned. In death from chronic lead-poisoning,

there is but little that can be called diagnostic; a granular condition

of the kidneys, and all the pathological changes dependent on such a

condition, are most frequently seen. If the patient has suffered from

colic, a constriction of portions of the intestine has been noticed;

also, in cases in which there has been long-standing paralysis of groups

of muscles, these muscles are wasted, and possibly degenerated. In

instances, again, in which lead has induced gout, the pathological

changes dependent upon gout will be prominent. The blue line around the

gums, and sometimes a coloration by sulphide of lead of portions of the

intestines, may help a proper interpretation of the appearances seen

after death; but all who have given any attention to the subject will

agree that, simply from pathological evidence, it is impossible to

diagnose chronic lead-poisoning.

§ 788. =Physiological Action of Lead.=--The action of lead is still

obscure, but it is considered to have an effect mainly on the nervous

centres. The paralysed muscles respond to the direct current, but not to

the induced, leading to the suspicion that the intramuscular

terminations of the nerves are paralysed, but that the muscular

substance itself is unattacked. On the other hand, the restriction of

the action to groups of muscles supports the theory of central action.

The lead colic is due to a true spasmodic constriction of the bowel, the

exciting cause of which lies in the walls of the bowel itself; the

relief given by pressure is explained by the pressure causing an anæmia

of the intestinal walls, and thus lessening their sensibility. The

slowing of the pulse produced by small doses is explained as due to a

stimulation of the inhibitory nerves; and, lastly, many nervous

phenomena, such as epilepsy, &c., are in part due to imperfect

elimination of the urinary excreta, causing similar conditions to those

observed in uræmia.

§ 789. =Elimination of Lead.=--When a large dose of acetate or carbonate

is taken, part is transformed into more or less insoluble

compounds--some organic, others inorganic; so that a great portion is

not absorbed into the body at all, but passes into the intestines,

where, meeting with hydric sulphide, part is changed into sulphide,

colouring the alvine evacuations black. Some of the lead which is

absorbed is excreted by the kidneys, but the search often yields only

traces. Thudichum[853] states that in fourteen cases of lead-poisoning,

in two only was obtained a weighable quantity from a day’s urine; in the

remaining twelve lead was detected, but only by the brownish colour

produced in an acid solution of the ash by hydric sulphide.

[853] _Pathology of the Urine_, p. 550.

The elimination of lead by the kidneys is favoured by certain medicines,

such, for example, as potassic iodide. Annuschat found in dogs poisoned

by lead from 3·8 to 4·1 mgrms. in 100 c.c. of urine; but, after doses of

potassic iodide, the content of lead rose to 6·9 and even to 14 mgrms.

Lead appears to be eliminated by the skin, being taken up by the

epithelial cells, and minute, insoluble particles coming away with these

cells. If a person who has taken small doses of lead for a time be

placed in a sulphur water-bath, or have his skin moistened with a 5 per

cent. solution of sodium sulphide, the upper layer of the epidermis is

coloured dark; but the perspiration excited by pilocarpin or other

agency contains no lead.

§ 790. =Fatal Dose=--(_a._) =Sugar of Lead.=--It may almost be said that

it is impossible to destroy human life with any single dose likely to be

taken or administered. In three cases an ounce (28·3 grms.) has been

taken without fatal result. Although it must be allowed that repeated

moderate doses, extending over some time, are more dangerous to health

and life than a single large dose, yet there seems to be in some

individuals a great tolerance of lead. Christison has given ·18 grm. in

divided doses daily for a long time without any bad effect, save the

production of a slight colic. Swieten has also given daily 3·9 grms. (60

grains) in ten days without observing toxic effects. That, in other

cases, less than a grain per gallon of some lead compound dissolved in

drinking-water, or in some way introduced into the economy, causes

serious illness, is most inexplicable.

(_b._) =The Basic Acetate= in solution is more poisonous apparently than

the acetate--60 c.c. (1½ drms.) have caused serious symptoms.

(_c._) =The Carbonate of Lead.=--Doses of anything like 28 grms. (an

ounce) would probably be very dangerous to an adult; the only case of

death on record is that of a child who took some unknown quantity,

probably, from the description of the size of the lump, about 10 grms.

(2½ drms.).

§ 791. =Antidotes and Treatment.=--Soluble sulphates (especially

magnesic sulphate) have been given largely in both acute and chronic

cases; in the acute, it stands to reason that it is well to ensure the

presence of plenty of sulphates in the stomach and intestines, in order

to form the sparingly soluble lead sulphate, should any residue remain;

but to expect this double decomposition to go on in the blood and

tissues is not based upon sound observation. The chronic lead-poisoning

is best treated by removal from the source of mischief, the

administration of large quantities of distilled water, and medicinal

doses of potassic iodide.

§ 792. =Localisation of Lead.=--In a dog, which was killed by chronic

lead-poisoning, Heubel found in the bones 0·18 to 0·27 per 1000 of lead;

in the kidneys, 0·17 to 0·20; liver, 0·10 to 0·33; spinal cord, 0·06 to

0·11; brain, 0·04 to 0·05; muscles, 0·02 to 0·04; in the intestines

traces, 0·01 to 0·02; in the spleen, the blood, and the bile, he also

only found traces. Ellenberger and Hofmeister found in the kidneys of

the sheep, 0·44 to 0·47; liver, 0·36 to 0·65; pancreas, 0·54; salivary

glands, 0·42; bile, 0·11 to 0·40; bones, 0·32; fæces, 0·22; spleen,

0·14; central nervous system, 0·07 to 0·18; blood, 0·05 to 0·12; flesh,

0·05 to 0·08; urine, 0·06 to 0·08; and in the unstriped muscles and the

lungs, 0·03 per 1000 of lead.

Without going so far as to say that lead is a natural constituent of the

body, it is certain that it may be frequently met with in persons who

have been apparently perfectly healthy, and quite free from all symptoms

of lead-poisoning. Legrip found in the liver and spleen of a healthy

person, 5·4 mgrms. of lead oxide in every kilogram; Oidtmann, in the

liver of a man fifty-six years of age, 1 mgrm. of lead oxide per

kilogram, and in the spleen 3 mgrms. per kilogram. Hence, the analyst,

in searching for poison, must be very careful in his conclusions. Grave

and serious errors may also arise from complications; suppose, _e.g._,

that a deceased person previous to death had partaken of game, and

inadvertently swallowed a shot--if the analyst had not carefully

searched the contents of the stomach for _solid_ bodies, but merely

treated them at once with acid solvents, he would naturally get very

decided lead reactions, and would possibly conclude, and give evidence

to the effect, that a poisonous soluble salt of lead had been

administered shortly before death.

§ 793. =Detection and Estimation of Lead.=--A great number of fluids

(such as beer, wines, vinegar, water, &c.), if they contain anything

like the amount of one-tenth of a milligramme in 100 c.c., will give a

very marked dark colour with SH₂. It is, however, usually safest in the

first place to concentrate the liquid, to add an acid, and deposit the

lead on platinum, in the way to be shortly described. Nearly all the

lead from oils and fatty matter may be dissolved out by shaking up the

fat with dilute nitric acid; if necessary, the fat should previously be

melted.

If (in the usual course of routine research) a hydrochloric acid

solution is obtained from the treatment or destruction of organic

substances by that agent, and lead sulphide (mixed possibly with other

sulphides) is filtered off, any arsenical sulphide may first be

extracted from the filter by ammonia, and any antimonious sulphide by

sodic sulphide; then the sulphide may be extracted by warm hydrochloric

acid, which will leave undissolved such sulphides as those of copper and

mercury. On diluting the liquid, and filtration at a boiling

temperature, crystals of lead chloride will be deposited on cooling.

If, however, organic matters are _specially_ searched for lead,

hydrochloric acid is not the best solvent, but nitric should always be

preferred; and, if there is reason to think that the lead exists in the

form of sulphate, then the proper solvent is either the acetate or the

tartrate of ammonia; but, in either case, the solution should contain an

excess of ammonia. It must, however, be remembered that organic matters

retain lead with great tenacity, and that in all cases where it can with

any convenience be effected, the substances should be not only

carbonised, but burnt to an ash; for Boucher has shown[854] that carbon

retains lead, and that the lead in carbon resists to a considerable

extent the action of solvents.

[854] _Ann. d’Hygiène_, t. xli.

In the case of sulphate of lead, which may be always produced in an ash

from organic substances by previous treatment with sufficient sulphuric

acid, a very excellent method of identification is to convert it into

sugar of lead. To do this, it is merely necessary to boil it with

carbonate of ammonia, which changes it into carbonate of lead; treatment

with acetic acid will now give the acetate; the solution may (if the

lead is in very small quantity) be concentrated in a watch-glass, a

drop evaporated to dryness on a circle of thin microscopic glass, and

the crystals examined by the microscope; the same film next exposed to

the fumes of SH₂, which will blacken it; and lastly, the solution (which

should be sweet) tasted. A crystalline substance, possessing a sweet

taste, and blackening when exposed to SH₂, can, under the circumstances,

be no other substance than acetate of lead.

If the analyst does not care for this method, there is room for choice.

Lead in solution can be converted into sulphide; in this case it is,

however, absolutely necessary that there should be no great excess of

acid, since as little as 2·5 per cent. of free hydrochloric acid will

prevent all the lead going down. On obtaining the sulphide, the latter,

as already described, can be converted into chloride by hydrochloric

acid, and the crystalline chloride is extremely characteristic.

From the solution of the chloride the metal may be obtained in a solid

state by inserting a piece of zinc in the solution contained in a

crucible; the lead will be deposited gradually, and can be then

collected, washed, and finally fused into a little globule on charcoal.

A lead bead flattens easily when hit with a hammer, and makes a mark on

paper. Solutions of the chloride also give a heavy precipitate of lead

sulphate, when treated with a solution of sodic sulphate.

When lead is in very minute quantity, an electrolytic method is

generally preferable; the lead is precipitated on platinum by using

exactly the same apparatus as in Bloxam’s test, described at p. 566; the

liquid to be tested being placed in the inner cell, the lead film may

now be identified, dissolved in nitric acid, and estimated by a

colorimetric process. For the estimation of the minute fractions of a

grain by a colour method, it is merely necessary to have a very dilute

solution of acetate of lead, to add a known volume of SH₂ water to the

liquid to be tested in a Nessler cylinder, noting the colour, and add to

another a known quantity of the standard lead solution and the same

quantity of SH₂ as was added to the first.

The process has an advantage which is great, viz., that it either

detects copper, or proves its absence at the same time; and there are

few cases in which the analyst does not look for copper as well as for

lead. Lead, if in sufficient quantity, may be most conveniently

estimated as oxide, sulphate, or chloride; the chief properties of these

substances have been already described.

§ 794. =The Detection of Lead in Tartaric Acid, in Lemonade, and Aërated

Waters.=--To detect lead in tartaric acid a convenient method is to burn

it to an ash, digest in a little strong sulphuric acid, and then add

either sodic chloride or a drop of HCl; lead, if present, is

precipitated as chloride, giving a pearly opalescence. Lemonades often

contain minute quantities of iron and copper as well as lead. Neither

copper nor iron are precipitated by ammonium sulphide in presence of

potassic cyanide. On the other hand, the sulphide of lead is not soluble

in the alkaline cyanides. Hence a liquid which, on the addition of

potassium cyanide and then ammonium sulphide, becomes dark coloured, or

from which a precipitate separates, contains lead.[855]

[855] F. L. Teed, _Analyst_, xvii. 142-143.

2. COPPER.

§ 795. =Copper=, Cu = 63·5; specific gravity, from 8·921 to 8·952;

fusing-point, 1091° (1996° F.). Copper in analysis occurs either as a

film or coating on such metals as platinum, iron, &c., or in a state of

fine division; or, finally, as a bead. In thin films, copper has a

yellowish or a yellowish-red colour; it dissolves readily in nitric,

slowly in hydrochloric acid. If air be excluded, hydrochloric acid fails

to dissolve copper, and the same remark applies to ammonia; but, if

there be free access of air, ammonia also acts as a slow solvent.

Metallic copper in a fine state of division can be fused at a white heat

to a bright bluish-green globule, which, on cooling, is covered with

black oxide.

§ 796. =Cupric Oxide= (CuO = 79·5; specific gravity, 6·5, composition in

100 parts, Cu 79·85, O 20·15) is a brownish-black powder, which remains

in the absence of reducing gases unaltered at a red heat. It is nearly

insoluble in water, but soluble in ClH, NO₃H, &c.; it is hygroscopic,

and, as every one who has made a combustion knows, is readily reduced by

ignition with charcoal in the presence of reducing gases.

§ 797. =Cupric Sulphide=, CuS = 95·5, produced in the wet way, is a

brownish powder so insoluble in water that, according to Fresenius,

950,000 parts of water are required to dissolve one part. It is not

quite insoluble in ClH, and dissolves readily in nitric acid with

separation of sulphur. By ignition in a stream of H it may be converted

into the subsulphide of copper. It must always be washed by SH₂ water.

§ 798. =Solubility of Copper in Water and Various Fluids.=--The

solubility of copper in water and saline solutions has been very

carefully studied by Carnelley.[856] Distilled water exerts some solvent

action, the amount varying, as might be expected, according to the time

of exposure, the amount of surface exposed, the quantity of water acting

upon the copper, &c. It would appear that, under favourable

circumstances, 100 c.c. of distilled water may dissolve ·3 mgrm. of

copper (·2 grain per gallon).

[856] _Journ. Chem. Soc._, 1876, vol. ii. p. 4.

With regard to salts, those of ammonium exert a solvent action on

copper more decided than that of any others known. With the others,

however, the nature of the base exerts little influence, the action of

the salt depending chiefly on the nature of its acid radical. Thus,

beginning with the least effective, the following is the order of

dissolving strength:--Nitrates, sulphates, carbonates, and chlorides. It

will then at once be evident that a water, contaminated by sewage, and

therefore containing plenty of ammonia and chlorides, might exert a very

considerable solvent action on copper.

Almost all the oils and fats, as well as syrups, dissolve small

quantities of copper; hence its frequent presence in articles of food

cooked or prepared in copper vessels. In the very elaborate and careful

experiments of Mr. W. Thompson,[857] the only oils which took up no

copper, when digested on copper foil, were English neats’-foot oil,

tallow oil, one sample of olive oil, palm-nut oil, common tallow oil,

and white oil, which was protected from the air by a thick coating of

oxidised oil on its surface.

[857] “Action of Fatty Oils on Metallic Copper,” _Chem. News_, vol.

xxxiv. pp. 176, 200, 313.

The formation of copper compounds with the fatty acids takes place so

readily that Jeannel[858] has proposed the green colouring of fats by

copper as a test for the presence of copper; and Bottger[859] recommends

a copper holding brandy to be shaken up with olive oil to free it from

copper.

[858] _L’Union pharmac._, xvii. 81.

[859] _Arch. de Pharm._, 1853, cxxvi. 67.

Lehmann has made some useful researches on the amount of copper taken up

by fats under different conditions. 100 c.c. of strongly rancid fat

dissolved in fourteen days 8·7 mgrms. of copper; but when heated to 160°

for one hour, and then allowed to stand, a similar amount was found.

Some rancid butter was rubbed into a brass bowl of 90 c.c. capacity, and

then allowed to stand for twenty-four hours; the butter became of a

blue-green colour. Into this dish, thus partially attacked by fatty

acids, 50 c.c. of rancid butter was poured in a melted condition, and

allowed to stand for twenty-four hours. The amount taken up was found to

be equal to 10 mgrms. of copper for every 100 c.c. of fluid butter.

Hilger found a fatty soup, which had stood twelve hours in a clean

copper vessel, to contain 0·163 per cent. copper. According to Tschirch,

the easiest fatty salt to form is the oleate, hydrated copper oxide

dissolving in oleic acid with great ease, and even copper oxide

dissolving to some extent; the palmitate and the stearate are not so

readily produced; hence the amount of copper dissolved is greater in the

case of olive oil and butter (both rich in oleic acids) than in the case

of the firmer animal fats. Acid solutions, such as clarets, acetic acid,

vinegars, and so forth, as might be expected, dissolve more or less

copper. The amount likely to be dissolved in practice has been

investigated by Lehmann. He steeped 600 square metres of copper

sheeting or brass sheeting in vessels holding 2 litres of acid claret;

the sheets were in some of the experiments wholly immersed, in others

partly so. More copper was dissolved by the wine when the copper was

partly immersed than when it was wholly immersed; and more copper was

dissolved from brass sheeting than from pure copper sheeting. With a

sheet of copper, partly immersed, claret may contain as much as 56

mgrms. per litre. Lehmann also investigated the amount of copper, as

acetate, which could be dissolved in wine before the taste betrayed its

presence: with 50 mgrms. per litre no copper taste; with 100 mgrms.

there was a weak after taste; with 150 mgrms. it was scarcely drinkable,

and there was a strong after taste; with 200 mgrms. per litre it was

quite undrinkable, and the colour was changed to bluish-green. Vinegar,

acting under the most favourable circumstances on sheet brass or copper,

dissolved, in seven days, 195 mgrms. of copper per litre from the copper

sheet, 195 from the brass sheet.