under the circumstance that everything eaten or drank has been
artificially coppered, but none “coppered” to the extent by which the
presence of the metal could be betrayed by the taste; and the following
is, he thinks, possible:--
300 c.c. of soup boiled in a copper vessel, 20 mgrms. Cu.
1 litre of wine which has been standing in a
copper vessel, 50 „
50 c.c. vinegar which has been kept in a copper
vessel, 10 „
50 grms. of fat which has been used for frying in a
copper vessel, 5 „
200 grms. of strongly coppered peas, 50 „
500 grms. of strongly coppered bread, 60 „
The total only amounts to 195 mgrms. of copper, which only slightly
exceeds a high medicinal dose. The metal is tasted more easily in
liquids, such as wine, than in bread; bread may be coppered so that at a
meal a person might eat 200 mgrms. of a copper compound without tasting
it.
It is pretty well accepted that cooking in clean bright copper vessels
will not contaminate any ordinary food sufficiently to be injurious to
health.
§ 799. =Copper in the Vegetable and Animal Kingdom and in
Foods.=--Copper is widely distributed in the vegetable kingdom, and is a
constant constituent of the chief foods we consume; the following
quantities, for example, have been separated from the chief cereals:--
Wheat, 5·2 to 10·8 mgrms. per kilo.
Rye, 5 mgrms. „
Oats, 8·5 „ „
Barley, 11·8 „ „
Rice, 1·6 „ „
Bread, 1·5 to 4·4 mgrms. „
It has also been found in vermicelli (2-10 mgrms. per kilo.), groats
(1·6-3 mgrms. per kilo.), potatoes (1·8 mgrm. per kilo.), beans (2-11
mgrms. per kilo.). In similar small quantities it has also been found in
carrots, chicory, spinach, hazel-nuts, blackberries, peaches, pears,
figs, plums, tamarinds, black pepper, and many other fruits and spices.
The most common food which has a high copper content is cocoa, which
contains from 12 mgrms. to 29 mgrms. per kilo., the highest amount of
copper being in the outer husk; copper has also been found in many
supplies of drinking water, in aërated waters, in brandies, wines, and
many drugs.
It has been calculated that the ordinary daily food of an average man
contains the following:--
Copper.
900 grms. bread, 0·45 mgrm.
260 grms. meat, 0·25 „
200 grms. fruit and vegetables, 0·25 „
----
0·95 mgrm.
That is to say, that, neglecting altogether foods artificially
contaminated with copper, each of us eats daily about 1 mgrm. of copper
(0·015 grain).
In the animal kingdom it is a constant and natural constituent of the
blood of the cephalopods, crustacea, and gasteropods, and is nearly
always present in the liver and kidneys of domestic animals, as well as
in men. Dr. Dupré[860] found ·035 to ·029 grain (1·8 to 2 mgrms.) in
human livers, or about 1 part in 500,000. Bergeron and L. L’Hôte’s
researches on fourteen bodies, specially examined for copper, fully
substantiate those of Dr. Dupré; in twelve the copper was found in
quantities of from ·7 to 1·5 mgrm.; in the remaining two the amount of
copper was very minute, and was not estimated.[861] Copper is also found
normally in the kidneys, and Dupré [862] detected in human kidneys about
1 in 100,000 parts; it is also found in the bile, and in minute traces
in the blood.[863]
[860] _Analyst_, No. 13, 1877.
[861] _Compt. Rendus_, vol. lxxx. p. 268.
[862] _Op. cit._
[863] Hoppe-Seyler, _Handbuch der physiologisch. Analyse_, p. 415.
In the kidneys and livers of the ruminants copper may always be found, a
sheep’s liver containing about 1 part in 20,000.[864] Church found
copper in the feathers of the wings of the turaco; melopsitt in the
feathers of a parroquet (_Melopsittacus undulatus_).[865] In these cases
the copper enters into the composition of the colouring matter to which
the name of “turacin” has been given. Turacin contains 7 per cent. of
copper, and gives to analysis numbers which agree with the formula of
C₈₂H₈₁Cu₂N₉O₃₂.
[864] Dupré, _op. cit._
[865] _Chem. News_, xxviij. 212.
Copper has been discovered in aërated waters, its presence being due to
the use of copper cylinders, the tin lining of which had been rendered
defective by corrosion.[866]
[866] “On the Presence of Lead and Copper in Aërated Waters,” by Dr.
James Milne, _Chem. News_, xxxi. p. 77.
Accidents may also occur from the use of copper boilers. Mr. W. Thompson
found in one case[867] no less than 3·575 grains in a gallon (51 mgrms.
per litre) in water drawn from a kitchen boiler.
[867] _Chem. News_, xxxi. No. 801.
At Roubaix, in France, sulphide of copper had been deposited on the
roof, as a consequence of the use of copper flues; the sulphide was
changed into sulphate by the action of the air, and washed by the rain
into the water-tank.[868]
[868] Author’s _Dictionary of Hygiène_, p. 167.
That preserved vegetables are made of a bright and attractive green
colour by impregnation with copper, from the deliberate use of copper
vessels for this purpose, is a fact long known. Green peas especially
have been coloured in this way, and a number of convictions for this
offence have taken place in England.
§ 800. =The “Coppering” of Vegetables.=--The fact that green vegetables,
such as peas, beans, cucumbers, and so forth, preserve their green
colour, if boiled in copper vessels, has long been known. In this
“coppering” the French have been more active than the English traders;
the French operate in two different ways. One method is, to dip from 60
to 70 litres of the green vegetables in 100 litres of 0·3 to 0·7 per
cent. of copper sulphate, to leave them there for from five to fifteen
minutes, then to remove them, wash and sterilise in an autoclave. A
second method is to put the vegetables into a copper vessel, the wall of
which is connected with the negative pole of an electric current, the
positive pole dips in a solution of salt in the same vessel, the current
is allowed to pass for three minutes, and the vegetables are afterwards
sterilised. Fruits are simply allowed to stand with water in copper
vessels, the natural acidity of the juice dissolving sufficient copper.
The amount of copper taken up in this way is appreciable, but yet not so
much as might be expected; the prosecutions for selling “coppered” peas
in England have been based upon quantities varying from 1 to 3 grains
per lb.; the highest published amount of copper found in peas
artificially coloured is 0·27 per kilo., or 18·9 grains per lb.
The reason why vegetables preserve their green colour longer when
treated with a copper salt has been proved by Tschirch[869] to be owing
to the formation of a phyllocyanate of copper.
[869] _Das Kupfer_, Stuttgart, 1893.
Phyllocyanic acid is a derivative of chlorophyll, and allied to it in
composition; the formula of C₂₄H₂₈N₂O₄ has been ascribed to it. Under
the action of acids generally, mineral or organic, chlorophyll splits up
into this acid and other compounds. Copper phyllocyanate,
(C₂₄H₂₇N₂O₄)₂Cu, contains 8·55 per cent. of copper; it forms black
lamellæ, dissolving easily in strong alcohol and chloroform, but
insoluble in water; it is a little soluble in ether, insoluble in
petroleum ether, and dissolved neither by dilute acetic acid, nor by
dilute nor concentrated hydrochloric acid. The compound dissolves in
caustic alkali on warming. In alcohol it forms a beautiful
non-fluorescent solution. A solution of 1 : 100,000 is still coloured
strongly green.
This solution, in a stratum of 25 mm. thick, gives four absorption bands
when submitted to spectroscopic observation, and Tschirch has worked out
a process of estimation of the amount of copper phyllocyanate based upon
the disappearance of these bands on dilution.
Green substances, so carefully treated that they only contain
phyllocyanate of copper, would yield but small quantities of copper, and
probably they would not be injurious to health; but the coppering is
usually more extensive, and copper leguminate and other compounds are
formed; for the vegetables, when exhausted by alcohol, give a residue
which, successively exhausted by water, by soda-lye, and lastly by
hydrochloric acid, parts with copper into the three solvents mentioned.
It might be argued that, from the insoluble character of the
phyllocyanate of copper, and especially seeing that it does not dissolve
in strong hydrochloric acid, that it would be perfectly innocuous; but
Tschirch has proved that, whether the tartrate of copper (dissolving
easily in water), or copper oxide (not dissolving at all in water, but
soluble in hydrochloric acid), or phyllocyanate of copper (insoluble
both in water and in hydrochloric acid) be used, the physiological
effect is the same.
Copper may be found in spirits, owing to the use of copper condensers, a
remark which applies also to the essential oils, such as _oleum
cajepute_, _menthæ_, &c.[870] In France, it has been added fraudulently
to absinthe, to improve its colour.[871] Green sweetmeats, green toys,
green papers, have all been found to contain definite compounds of
copper to a dangerous extent.
[870] According to Eulenberg (_Gewerbe Hygiene_, p. 716), _Oleum
cajepute_, _Menth. pip._, _Melissæ_, _Tanaceti_, &c., are almost always
contaminated with copper.
[871] Tardieu, _Étude Méd. Lég. sur l’Empoisonnement_.
§ 801. =Preparations of Copper used in Medicine and the Arts.=
(1) =Medicinal Preparations=:--
=Sulphate of Copper=, =Cupri Sulphas=, CuSO₄5H₂O.--This well-known salt
is soluble in water at ordinary temperature, 3 parts of water dissolving
1 of the sulphate; but boiling water dissolves double its weight; 1 part
of copper sulphate dissolves in 2½ of glycerin; it reddens litmus, and
is slightly efflorescent; its solution responds to all the usual tests
for copper and sulphuric acid. A watery solution of the salt to which
twice its volume of a solution of chlorine has been added, gives, when
treated with ammonia in excess, a clear sapphire-blue solution, leaving
nothing undissolved, and thus showing the absence of iron. Besides
iron, sulphate of copper has been found to contain zincic sulphate.
=Nitrate of Copper=, Cu(NO₃)₂3H₂O, is officinal; it is very soluble.
=Cuprum Aluminatum.=--A preparation, called cuprum aluminatum (_Pierre
divine_), is in use in France and Germany, chiefly as an external wash.
It is composed of 16 parts cupric sulphate, 16 potassic nitrate, 16
alum, fused in a crucible, a little camphor being afterwards added.
Regular and irregular medical practitioners, veterinary surgeons,
farriers, and grooms, all use sulphate of copper (bluestone) as an
application to wounds. Copper as an _internal_ remedy is not in favour
either with quacks or vendors of patent medicines. The writer has not
yet found any patent pill or liquid containing it.
(2) =Copper in the Arts.=--Copper is used very extensively in the arts;
it enters into the composition of a number of alloys, is one of the
chief constituents of the common bronzing powders, is contained in many
of the lilac and purple fires of the pyrotechnist, and in a great
variety of pigments. The last-mentioned, being of special importance,
will be briefly described:--
=Pigments=:--
=Schweinfurt and Scheele’s Green=[872] are respectively the
aceto-arsenite and the arsenite of copper (see article “Arsenic”).
[872] The synonyms for Schweinfurt green are extremely numerous:--Mitic
green, Viennic green, imperial green, emerald green, are the principal
terms in actual use.
=Brighton Green= is a mixture of impure acetate of copper and chalk.
=Brunswick Green=, originally a crude chloride of copper, is now
generally a mixture of carbonate of copper and chalk or alumina.
=Mountain Green=, or =Mineral Green=, is the native green carbonate of
copper, either with or without a little orpiment.
=Neuwieder Green= is either the same as mountain green, or Schweinfurt
green mixed with gypsum or sulphate of baryta.
=Green Verditer= is a mixture of oxide and carbonate of copper with
chalk.
=Verdigris= is an acetate of copper, or a mixture of acetates. Its
formula is usually represented as (C₂H₃O₂)CuO. It is much used in the
arts, and to some extent as an external application in medicine. Its
most frequent impurities or adulterations are chalk and sulphate of
copper.
§ 802. =Dose--Medicinal Dose of Copper.=--Since sulphate of copper is
practically the only salt administered internally, the dose is generally
expressed as so many grains of sulphate. This salt is given in
quantities of from ·016 to ·129 grm. (¼ to 2 grains) as an astringent or
tonic; as an emetic, from ·324 to ·648 grm. (5 to 10 grains).
The sulphate of copper is given to horses and cattle in such large
doses as from 30 up to 120 grains (1·9 to 7·7 grms.); to sheep, from
1·3 to 2·6 grms. (20 to 40 grains); rabbits, ·0648 to ·1296 grm. (1 to 2
grains).
§ 803. =Effects of Soluble Copper Salts on Animals.=--Harnack has made
some experiments on animals with an alkaline tartrate of copper, which
has no local action, nor does it precipitate albumin. ½ to ¾ mgrm. of
copper oxide in this form, administered subcutaneously, was fatal to
frogs, ·05 grm. to rabbits, ·4 grm. to dogs. The direct excitability of
the voluntary muscles was gradually extinguished, and death took place
from heart paralysis. Vomiting was only noticed when the poison was
administered by the stomach.[873] The temperature of animals poisoned by
copper, sinks, according to the researches of F. A. Falck, many degrees.
These observations are in agreement with the effects of copper salts on
man, and with the experiments of Orfila, Blake, C. Ph. Falck, and
others.
[873] On the other hand, Brunton and West have observed vomiting
produced in animals after injection of copper peptone into the jugular
vein.--_Barth. Hosp. Rep._, 1877, xii.
Roger[874] experimented on the effect of copper leguminate which was
administered subcutaneously; he found gradual increasing paralysis of
the motor spinal tracts, which finally destroyed life by paralysis of
the breathing centre. The heart beat after the breathing had stopped.
The irritability and contractility of the muscles of frogs were lost,
while sensibility remained. He also found that, if the copper was
injected into the intestinal vessels, the dose had to be doubled in
order to destroy life; this is, doubtless, because the liver, as it
were, strained the copper off and excreted it through the bile. Roger
was unable to destroy life by large doses of copper given by the mouth,
for then vomiting supervened and the poison in great part was removed.
[874] _Revue de Médecine_, 1877, xii.
Bernatzic[875] considers that the poisonous properties of copper are
similar to those of zinc and silver. He says: “Silver, copper, and zinc
are, in their medicinal application, so much allied that, with regard to
their action, they graduate one into the other and show only minor
differences; copper, which is a little the more poisonous of the three
so far as its remote action is concerned, stands between the other two.
If taken, in not too small a quantity, for a long time, the functional
activity of the muscular and nervous systems is influenced injuriously,
the development of the animal cells is inhibited, the number of the red
blood corpuscles decreased, and therefore the oxidising process and
metabolism are likewise diminished, leading ultimately to a condition of
marked cachexia. . . . From a toxic point of view, the three metals
named also stand near each other, and their compounds differ from other
metals injurious to the organism in this, that they do not produce
notable changes of the tissues or coarse functional disturbances leading
to death as other poisonous metals, and therefore are not to be
considered poisons in the same sense as lead, mercury, arsenic,
antimony, phosphorus are considered poisons; for, on stopping the entry
of the poison, any injurious effect is completely recovered from and the
functions again become normal.”
[875] _Encycloped. d. ges. Heilkunde_, xi. S. 429.
Lehmann[876] has also experimented on the effects of copper; his
experiments were made on both animals and men. He found that small
quantities were more thoroughly absorbed than medium or large doses; the
method of separation appeared to be different in different
animals--thus, the chief copper-excreting organ in dogs is the liver; in
rabbits, the intestine; and in man, the kidneys. Of 3 mgrms. of copper
taken by a man in three days, 1 mgrm., or a third, was recovered from
the urine. Lehmann experimented on 6 rabbits, 4 cats, and 1 dog. During
the first few days the animals were given 10 to 30 mgrms. of copper, in
the form of a salt, in their food; then the dose was raised to 50 mgrms.
or even to 100 mgrms., and the experiment continued for from two to four
months; in one case, six months. The sulphate, acetate, chloride,
oleate, butyrate, and lactate were all tried, but no essential
difference in action discovered. Apart from slight vomiting, and in a
few cases, as shown by _post-mortem_, a slight catarrh of the stomach,
the animals remained well. A few increased in weight. Nervous symptoms,
cramps, convulsions, diarrhœa, or the reverse, were not observed. The
analysis of the organs showed considerable copper absorption; the liver
of the cats gave a mean amount of 12 mgrms. of copper, and in the other
organs there was more copper than is found in cases of acute poisoning.
[876] _Münch. med. Wochenschrift_, 1891, Nr. 35 u. 36.
Lehmann has also made experiments upon himself and his pupils on the
effect of the sulphate and the acetate when taken for a long time:--
One of the experimenters took for 50 days 10 mgrms. daily Cu as
sulphate.
„ „ „ then for 30 „ 20 „ „
Another took for 3 days 5 mgrms. as acetate.
„ then for 10 days 10 „ „
„ „ 1 day 15 „ „
„ „ 19 days 20 „ „
„ „ 18 days 30 „ „
None of these daily doses had the least effect.
Five farther experiments showed that 75 to 127 mgrms. of copper in peas
and beans, divided in two meals, could be taken daily without effect;
but if 127 mgrms. were taken at one meal in 200 grms. of peas, then,
after a few hours, there might be vomiting; and Lehmann concludes that
doses of copper in food of about 100 mgrms. may produce some transient
derangement in health, such as sickness, a nasty taste in the mouth, and
a general feeling of discomfort, but nothing more; some slight colicky
pains and one or two loose motions are also possible, but were not
observed in Lehmann’s experiments.
§ 804. =Toxic Dose of Copper Salts.=--This is a difficult question,
because copper salts generally act as an emetic, and therefore very
large doses have been taken without any great injury. In fact, it may be
laid down that a medium dose taken daily for a considerable time is far
more likely to injure health, or to destroy life, than a big dose taken
at once. In Tschirch’s[877] careful experiments on animals, he found 10
mgrm. doses of CuO given daily to rabbits, the weight of which varied
from 1200 to 1650 grms., caused injury to health, that is, about 3·5
mgrms. per kilo. If man is susceptible in the same proportion, then
daily doses of 227·5 mgrms. (or about 3½ grains) would cause serious
poisonous symptoms; although double or treble that quantity might in a
single dose be swallowed and, if thrown up speedily, no great harm
result. 120 grms. of sulphate of copper have been swallowed, and yet the
patient recovered after an illness of two weeks.[878] Lewin[879]
mentions the case of an adult who recovered after ten days’ illness,
although the dose was 15 grms.; there is also on record the case of a
child, four and a half years old, who recovered after a dose of 16·5
grms. (a little over half an ounce). On the other hand, 7·7 grms. have
been with difficulty recovered from.[880] A woman died in seventy-two
hours after taking 27 grms. (7 drms.) of copper sulphate mixed with 11·6
grms. (3 drms.) of iron sulphide; 56·6 grms. (2 ozs.) of copper acetate
have caused death in three days; 14·2 grms. (0·5 oz.) in sixty
hours.[881]
[877] _Das Kupfer_, Stuttgart, 1893.
[878] Referred to by Bernatzic, on the authority of Ketli, in _Encycl.
d. ges. Heilkunde_, xi. S. 433.
[879] _Toxicologie_, S. 133.
[880] D Taylor, _op. cit._
[881] Sonnenschein, _op. cit._
§ 805. =Cases of Acute Poisoning.=--Acute poisoning by salts of copper
is rare; in the ten years ending 1892, there were registered in England
8 deaths from this cause--3 suicidal (2 males, 1 female) and 5
accidental (4 males, 1 female). The symptoms produced by the sulphate of
copper are those of a powerful irritant poison: there is immediate and
violent vomiting; the vomited matters are of a greenish colour--a green
distinguished from bile by the colour changing to blue on the addition
of ammonia. There is pain in the stomach, and in a little time
affections of the nervous system, as shown by spasms, cramps, paralysis,
and even tetanus. Jaundice is a frequent symptom, if life is prolonged
sufficiently to admit of its occurrence.
One of the best examples of acute poisoning by copper sulphate is
recorded by Maschka.[882] A youth, sixteen years old, took an unknown
large dose of powdered copper sulphate, mixed with water. Half an hour
afterwards there was violent vomiting, and he was taken to the hospital.
There was thirst, retching, constriction in the throat, a coppery taste
in the mouth, and pain in the epigastrium, which was painful on
pressure. The vomit was of a blue colour, and small undissolved crystals
of copper sulphate were obtained from it. The patient was pale, the
edges of the lips and the angles of the mouth were coloured blue, the
surface of the tongue had also a blue tint, the temperature was
depressed, the extremities cold, nails cyanotic, and the pulse small and
quick. Several loose greenish-yellow evacuations were passed; there was
no blood. The urine was scanty, but contained neither blood nor albumen.
During the night the patient was very restless; the next morning he had
violent headache, pain in the epigastrium, burning in the mouth and
gullet, but no vomiting. The urine was scanty, contained blood, albumen,
and colouring matter from the bile. On the fourth day there was marked
jaundice. The mucous membrane was very pale, the temperature low, pulse
frequent, and great weakness, cardiac oppression, and restlessness were
experienced. There were diarrhœa and tenesmus, the motions being
streaked with blood; the urine also contained much blood. The liver was
enlarged. The patient died in a state of collapse on the seventh day.
[882] _Wiener med. Wochenschr._, 1871, Nro. 26, p. 628.
In 1836 a girl, sixteen months old, was given bluestone to play with,
and ate an unknown quantity; a quarter of an hour afterwards the child
was violently sick, vomiting a bluish-green liquid containing some
pieces of sulphate of copper. Death took place in four hours, without
convulsions, and without diarrhœa.
§ 806. =Subacetate of Copper, Subchloride, and Carbonate=, all act very
similarly to the sulphate when given in large doses.
§ 807. =Post-mortem Appearances.=--In Maschka’s case, the chief changes
noted were in the liver, kidneys, and stomach. The substance of the
liver was friable and fatty; in the gall-bladder there were but a few
drops of dark tenacious bile. The kidneys were swollen, the cortical
substance coloured yellow, the pyramids compressed and pale brown. In
the mucous membrane of the stomach there was an excoriation the size of
a shilling, in which the epithelium was changed into a dirty brown mass,
easily detached, laying bare the muscular substance beneath, but
otherwise normal.
In a case of poisoning by verdigris (subacetate of copper) recorded by
Orfila,[883] the stomach was so much inflamed and thickened that
towards the pyloric end the opening into the intestine was almost
obliterated. The small intestines throughout were inflamed, and
perforation had taken place, so that part of the green liquid had
escaped into the abdomen. The large intestines were distended in some
parts, contracted in others, and there was ulceration of the rectum. In
other cases a striking discoloration of the mucous membrane, being
changed by the contact of the salt to a dirty bluish-green, has been
noticed, and, when present, will afford valuable indications.
[883] _Toxicologie_, vol. i. p. 787 (5th ed.).
§ 808. =Chronic Poisoning by Copper.=--Symptoms have arisen among
workers in copper or its salts, and also from the use of food
accidentally contaminated by copper, which lend support to the existence
of chronic poisoning. In the symptoms there is a very great resemblance
to those produced by lead. There is a green line on the margin of the
gums. Dr. Clapton[884] found the line very distinct in a sailor and two
working coppersmiths, and the two men were also seen by Dr. Taylor.
Cases of chronic poisoning among coppersmiths have also been treated by
Dr. Cameron,[885] but this symptom was not noticed. Corrigan speaks of
the line round the gums, but describes it as purple-red. Among workers
in copper, Lancereaux[886] has seen a black coloration of the mucous
membrane of the digestive canal; its chemical characters appear to agree
with those of carbon.
[884] _Med. Times and Gazette_, June 1868, p. 658.
[885] _Med. Times and Gazette_, 1870, vol. i. p. 581.
[886] _Atlas of Pathological Anatomy._
Metallic copper itself is not poisonous. A Mr. Charles Reed has
published a letter in the _Chemical News_ of Jan. 12, 1894, stating that
he was, when a boy, wounded in the shin by a copper percussion-cap, and
the cap remained in the tissues; it was removed from the shin after a
sojourn thereof some twelve years; about the year 1873 he noticed that
whenever a piece of clean iron or steel came in contact with his
perspiration it was at once covered with a bright coating of copper, and
this continued until the percussion-cap was removed. Presuming the truth
of this, it shows conclusively that metallic copper deposited in the
tissues is in itself not poisonous, and farther, that one method of
elimination is by the skin. The experiments already cited throw doubt as
to whether repeated small doses of copper taken for a long time produce
in a scientific sense chronic poisoning; those which apparently support
the view that there is such a thing as chronic poisoning by copper, have
been produced by copper mixed with other metals; and there is the
possibility that these cases are really due to lead or arsenic, and not
to copper. The great use of late years of solutions of copper sulphate
as a dressing to plants, for the purpose of preventing the ravages of
various parasites, has provided, so far as animals are concerned, much
material for the judgment of this question. Sheep have been fed with
vines which have been treated with copper sulphate, oxen and pigs have
consumed for a long time grass treated with a 3 per cent. of copper
sulphate, without the least health disturbance. Mach[887] has fed cows
with green food coppered up to 200 mgrms. of copper sulphate, without
observing the slightest bad effect, for long periods of time; and
Tschirch[888] summarises the evidence as to chronic poisoning as
follows:--“So it appears the contention that there is no chronic
poisoning in men or animals is at present uncontradicted; it is farther
to be considered proved that the small amounts of copper naturally in
food, or carefully introduced into food, are not injurious to the health
of those that take such food, because the liver, kidneys, and other
organs excrete the copper through the urine and bile, and prevent a
pernicious accumulation.” At the same time, Tschirch does not consider
the question is definitely settled; the experiments should, he thinks,
have been continued not for months, but for years, to obtain a
trustworthy judgment.
[887] Mach, _Bericht über die Ergebnisse der im Jahre 1886 ausgeführten
Versuche zur Bekämpfung der Peronospora_, St. Michele, Tyrol.
[888] _Op. cit._
It may also be remarked that, if we are to rely upon the separation of
copper by the kidneys and the liver, those organs are presumed to be in
a healthy state, which is not the case with a percentage of the
population; to persons whose liver or kidneys are unsound, even the
small amounts of copper found in “coppered” peas may act as a poison,
and the experiments previously detailed throw no light upon the action
of copper under such circumstances.
§ 809. =Detection and Estimation of Copper.=--Copper may occur either in
the routine process of precipitating by SH₂, or it may, as is generally
the case, be searched for specially. If copper is looked for in a
precipitate produced by SH₂, it is taken for granted that the
precipitate has first been treated successively by carbonate of ammonia,
sulphide of sodium, and hydrochloric acid; in other words, arsenic,
antimony, and lead have been removed. The moist precipitate is now
treated with warm nitric acid, which dissolves out copper sulphide with
separation of sulphur; if there is sufficient copper, the fluid shows a
blue colour, which of itself is an indication of copper being present.
The further tests are--(1) Ammonia gives a deeper blue; (2) ferrocyanide
of potash a brown-red colour or precipitate; (3) a few drops mixed with
a solution of tartrate of soda, alkalised with sodic hydrate, and boiled
with a crystal or two of grape-sugar, gives quickly a red precipitate of
oxide of copper; (4) a needle or a clean iron wire, or any simple
galvanic combination, immersed in, or acting on, the liquid, soon
becomes coated with the very characteristic reddish metallic film.
Various other tests might be mentioned, but the above are ample.
Special Examinations for Copper.
(1) =In Water and Liquids generally.=--The liquid may be concentrated,
and the copper separated by electrolysis. A simple method is to place
the liquid in a large platinum dish, and insert a piece of zinc, adding
a sufficient quantity of ClH to dissolve the zinc entirely; the copper
is found as an adherent film on the inner surface of the dish. It is
neater, however, and more accurate, to connect the platinum dish with
the negative plate of a battery, suspending in the liquid the positive
electrode. The modifications of this method are numerous; some chemists
use (especially for small quantities of copper) two small platinum
electrodes, either of foil or of wire, and on obtaining the film, weigh
the electrode, then dissolve the copper off by nitric acid, and
re-weigh. Such solid substances as peas are conveniently mashed up into
a paste with water and ClH; an aliquot part is carefully weighed and put
in a platinum dish, connected, as before described, with a battery; at
the end of from twelve to twenty-four hours all the copper is deposited,
and the dish with its film dried and weighed. The weight of the clean
dish, _minus_ the coppered dish, of course equals the copper. Fat and
oils are best thoroughly washed with hot acid water, which will, if
properly performed, extract all the copper. By the use of separating
funnels and wet filters, the fat or oil can be separated from the watery
liquid.
A galvanic test has been proposed, which is certainly very delicate,
1/100 of a mgrm. in solution being recognised with facility. A zinc
platinum couple is made with two wires; on leaving this in an acid
liquid containing a mere trace of copper, after several hours the
platinum will be found discoloured. If the discoloration is from copper,
on exposing the wire to hydrobromic acid fumes (easily produced from the
action of potassic bromide and sulphuric acid) and bromine, the wire
will become of a violet colour. This colour is easily recognised by
rubbing the wire on a piece of porcelain.[889]
[889] _Chem. News_, Nov. 30, 1877.
(2) =Animal Matters=, such as the liver, brain, spinal cord, &c., are
best entirely burnt to an ash, and the copper looked for in the
latter.[890] The same remark applies to bread and substances consisting
almost entirely of starchy matters. Any injurious quantity of copper
can, however, be extracted with hydrochloric acid and water; and,
although this method of extraction is not quite so accurate, it is
quicker.
[890] In exhumation of long buried bodies, it may be necessary to know
the composition of the soil. Sonnenschein mentions a skull, now in the
museum at Madrid, which was dug out of an old Roman mine, and is quite
green from copper compounds.--Sonnenschein’s _Handbuch_, p. 83.
§ 810. =Volumetric Processes for the Estimation of Copper.=--A number of
volumetric processes have been devised for the estimation of copper, but
for the purposes of this work it is unnecessary to detail them. When
copper is in too small a quantity to be weighed, it may then be
estimated by a colorimetric process.
One of the best of these is based upon the brown colour which
ferrocyanide of potash produces in very dilute solutions of copper. A
standard copper solution is obtained by dissolving sulphate of copper in
a litre of water, so that each c.c. contains 0·1 mgrm. Cu, and a
solution of ferrocyanide of potash in water is prepared, strength 4 per
cent. It is also convenient to have a solution of nitrate of ammonia,
which is found to render the reaction much more delicate.
The further details are on the well-known lines of colorimetric
estimations.
3. BISMUTH.
§ 811. =Bismuth=, Bi = 210; sp. gr., 9·799; fusing-point, 264° (507·2°
F.).--Bismuth, as obtained in the course of analysis, is either a black
metallic powder or an extremely brittle bead of a reddish-white colour.
The compounds which it will be necessary to briefly notice are the
peroxide and tersulphide.
§ 812. =The peroxide of bismuth=, Bi₂O₃ = 468; sp. gr., 8·211; Bi, 89·64
per cent., O, 10·36 per cent., as prepared by igniting the carbonate or
nitrate, is a pale lemon coloured powder, which can be fused without
loss of weight, but is reduced on charcoal, or in a stream of carbon
dioxide, to the metallic state. It is also reduced by fusion with
potassic cyanide or by ignition with ammonium chloride.
§ 813. =The Sulphide of Bismuth=, Bi₂S₃ = 516; Bi, 81·25 per cent., S,
18·75 per cent., occurs, in the course of analysis, as a brownish-black
or quite black precipitate, insoluble in water, dilute acids, alkalies,
alkaline sulphides, sulphate of soda, and cyanide of potassium, but
dissolving in moderately concentrated nitric acid with separation of
sulphur. It continually increases in weight when dried in the ordinary
way, and is completely reduced when fused with cyanide of potassium.
§ 814. =Preparations of Bismuth used in Medicine and the Arts.=
(1) =Pharmaceutical Preparations=:--
=Bismuthi Subnitras=, BiONO₃.H₂O.--A heavy white powder, insoluble in
water, and responding to the usual tests for bismuth and nitric acid.
The formula should yield 77 per cent. of bismuth oxide. Commercial
preparations, however, vary from 79 to 82 per cent.
=Bismuth Lozenges= (=Trochisci bismuthi=) are composed of subnitrate of
bismuth, magnesia carbonate, precipitated lime carbonate, sugar, and
gum, mixed with rose water. Each lozenge should contain 0·13 grm. (2
grains) of subnitrate of bismuth.
=Solution of Citrate of Bismuth and Ammonia= (=Liquor Bismuthi et
Ammoniæ citratis=), a colourless neutral or slightly alkaline fluid, sp.
gr. 1·07, responding to the tests for bismuth and ammonia. As an
impurity lead may be present, citric acid being so frequently
contaminated with lead. Carbonate of bismuth (_Bismuthi carbonas_),
(Bi₂O₂CO₃)₂H₂O is a fine white powder answering to the tests for carbon
dioxide and bismuth; it should yield 89·1 per cent. of bismuth oxide.
=A Nitrate of Bismuth=, Bi(NO₃)₃, an oleate of bismuth, an oxide of
bismuth, a subgallate of bismuth (_dermatol_), and a subiodide of
bismuth are also used in medicine.
(2) =Bismuth in the Arts.=[891]
[891] Bismuth is contained in all copper coinage--from the Bactrian
coins to our own; in all cupreous ores, except the carbonates, and in
nearly all specimens of commercial copper.--Field, _Chem. News_, xxxvi.
261.
The chief use of bismuth is in alloys and solders. The Chromate is
employed in calico-printing, and the subnitrate as a paint under the
name of pearl-white.
The salts of bismuth also occur in washes for the hair, and pearl-white
is used as a cosmetic, but only to a small extent.
§ 815. =Medicinal Doses of Bismuth.=--The subnitrate and carbonate are
prescribed in doses from ·0648 to 1·296 grm. (1 to 20 grains); the
valerianate, from ·1296 to ·648 grm. (2 to 10 grains); and the solution,
from 1·7 c.c. to 5·2 c.c. (½ drachm to 1½ drachm).
§ 816. =Toxic Effects of Bismuth.=--From the researches of Meyer and
Steinfeld[892] on animals, it appears that if birds or mammals are
poisoned with bismuth salts introduced subcutaneously, or by direct
injection, into the veins, death follows in from twenty-four to
forty-eight hours, the fatal issue being preceded by convulsions; after
death, the colon is intensely blackened, and it may be ulcerated, while
the small intestines and the stomach are healthy. If, however, sulphur
preparations are given by the mouth, there is then blackening of the
stomach, and there may also be ulcers. Meyer is of the opinion that SH₂
precipitates bismuth in the parenchyma, and the particles occluding the
capillaries thus cause small local necroses; that which escapes
precipitation is mainly excreted by the kidneys. Poisonous symptoms in
man have been known to occur from the treatment of wounds with bismuth
preparations;[893] the symptoms have been somewhat similar to mercurial
poisoning; there have been noticed stomatitis with salivation, loosening
of the teeth, a black colour of the mucous membrane of the mouth and
ulceration, also catarrh of the intestines, and the inflammatory
condition of the kidneys usual when that organ has to excrete metallic
substances not natural to the body, the “metallniere,” or metal kidney,
of the German writers. One case is recorded of death in nine days of an
adult after taking 7·7 grms. (2 drms.) of bismuth subnitrate. The
recorded symptoms were a metallic taste in the mouth, pain in the
throat, vomiting, purging, coldness of the surface, and spasms of the
arms and legs. A _post-mortem_ examination showed inflammatory changes
in the gullet, windpipe, and throughout the intestinal canal. Recovery
has, however, taken place from a single dose three times the amount
mentioned. It is possible that the fatal case was due to impure bismuth.
[892] L. Feder-Meyer, _Rossbach’s pharmak. Unters._, iii., 1882, No. 23;
Steinfeld, _Wirkung des Wismut. Inaug. Diss._, Dorpat, 1884; _Arch. exp.
P._, Bd. xx. 1886.
[893] _B. Med. Journal_, 1887, i. 749.
§ 817. =Extraction and Detection of Bismuth in Animal Matters.=--Bismuth
appears to be excreted principally by the bowels as sulphide of bismuth;
but it has also been detected in the urine, spleen, and liver; and
Lubinsky has found it in the saliva and in the epithelium of the mouth
of persons taking one of its preparations. Without denying the
possibility of its existing in a soluble state in the saliva, its
presence in the mouth may, under such circumstances, be ascribed to the
lodgment of particles of subnitrate or subcarbonate of bismuth in the
interstices of the teeth, &c. It will then be evident that, if a person
is supposed to have been poisoned by a large dose of bismuth, and the
analyst fail to find it in the stomach, the contents of the bowels
should be next examined.
The extraction of bismuth must be undertaken by nitric acid, and boiling
for at least two hours may be necessary to dissolve it out from the
tissues. Such organs as the liver and spleen are boiled in a finely
divided state with a litre of dilute nitric acid (strength, 5 per
cent.), for the time mentioned, filtered, and the filtrate evaporated to
dryness; the remainder is then carbonised by strong nitric acid; and,
finally, the charcoal is boiled with equal parts of nitric acid and
water, and the whole evaporated to dryness. By this method every trace
of bismuth is extracted. The dry residue may now be brought into
solution, and tested for bismuth. The best solvent for the nitrate of
bismuth is dilute nitric acid 50 per cent.; the dry residue is therefore
dissolved in 100 or 200 c.c. of the acid, and fractional parts taken for
examination:--
(1) The solution, poured into a large volume of warm distilled water,
gives a crystalline precipitate of subnitrate of bismuth. The only metal
giving a similar reaction is antimony, and this is excluded by the
method employed.
(2) The filtered fluid gives on addition of sodic chloride a precipitate
of oxychloride. This, again, is distinguished from oxychloride of
antimony by its insolubility in tartaric acid.
(3) Any bismuth precipitate, fused with soda on charcoal, gives a
brittle bead of bismuth; the coal is coated whilst warm a dark
orange-yellow, on cooling citron-yellow.
(4) The bead may be identified by powdering it, placing it in a short
subliming tube, and passing over it dry chlorine. The powder first turns
black, then melts to an amber-yellow fluid, and finally, by prolonged
heating, sublimes as terchloride of bismuth.
(5) A very delicate test proposed by Abel and Field, in 1862,[894]
specially for the detection of bismuth in copper (but by no means
confined to mineral analysis), utilises the fact that, if iodide of lead
be precipitated from a fluid containing the least trace of bismuth,
instead of the yellow iodide the scales assume a dark orange to a
crimson tint. A solution of nitrate of lead is used; to the nitric acid
solution ammonia and carbonate of ammonia added; the precipitate washed,
and dissolved in acetic acid; and, finally, excess of iodide of
potassium added. It is said that thus so small a quantity as ·00025 grm.
may be detected in copper with the greatest ease, the iodide of lead
becoming dark orange; ·001 grain imparts a reddish-brown tinge, and ·01
grain a crimson.
[894] _Journ. Chem. Soc._, 1862, vol. xiv. p. 290; _Chem. News_, vol.
xxxvi. p. 261.
(6) A solution of a bismuth salt, which must contain no free HCl, when
treated with 10 parts of water, 2 of potassium iodide, and 1 part of
cinchonine, gives a red orange precipitate of cinchonine
iod.-bismuth.[895]
[895] E. Légar, _Bull. de la Soc. Chim._, vol. iv., 1888, 91.
(7) Van Kobell’s test, as modified by Hutchings,[896] and proposed more
especially for the detection of bismuth in minerals, is capable of being
applied to any solid compound suspected of containing the metal:--A
mixture of precipitated and purified cuprous iodide, with an equal
volume of flowers of sulphur, is prepared, and 2 parts of this mixture
are made into a paste with 1 part of the substance, and heated on a slip
of charcoal on an aluminium support by the blowpipe flame. If bismuth be
present, the red bismuth iodide will sublime, and on clean aluminium is
easily distinguishable.
[896] _Chem. News_, vol. xxxvi. p. 249.
There are many other tests, but the above are sufficient.
§ 818. =Estimation of Bismuth.=--The estimation of bismuth, when in any
quantity easily weighed, is, perhaps, best accomplished by fusing the
sulphide, oxide, or other compound of bismuth, in a porcelain crucible
with cyanide of potassium; the bismuth is reduced to the metallic state,
the cyanide can be dissolved out, and the metallic powder washed (first
with water, lastly with spirit), dried, and weighed.
Mr. Pattison Muir has shown[897] that bismuth may be separated from
iron, aluminium, chromium, and manganese, by adding ammonia to the acid
solutions of these metals.
[897] Pattison Muir on “Certain Bismuth Compounds,” _Journ. Chem. Soc._,
p. 7, 1876.
This observation admits of many applications, and may be usefully taken
advantage of in the separation of bismuth from the nitric acid solution
of such animal matters as liver, &c. The acid liquid is partially
neutralised by ammonia, and, on diluting with warm water containing a
little sodium or ammonium chloride, the whole of the bismuth is
precipitated as oxychloride, which may be collected, and fused with
cyanide of potassium, as above.
If the bismuth precipitate is in small quantity, or if a number of
estimations of bismuth are to be made, it is most convenient to use a
volumetric process. In the case first mentioned, the oxychloride could
be dissolved in nitric acid, sodium acetate added in excess, and
sufficient acetic acid to dissolve any precipitate which has been
produced, and then titrated by the following method, which we also owe
to Mr. Pattison Muir:--
=Estimation of Bismuth by Potassium Dichromate.=[898]--A solution of
recrystallised potassium dichromate (strength, 1 per cent.) is prepared.
A known weight of pure bismuthous oxide (Bi₂O₃) is dissolved in excess
of nitric acid, and a solution of sodium acetate is added to this liquid
until a copious white precipitate is thrown down; acetic acid is then
added in quantity sufficient to dissolve the precipitate completely, and
to insure that, when the liquid is made up with water to a fixed volume,
no precipitate shall be formed. A certain volume of this liquid is
withdrawn by means of a pipette, placed in a beaker, and heated to
boiling; the potassium dichromate is then gradually run in from a
burette, the liquid being boiled between each addition of the solution,
until a drop of the supernatant liquid gives a faint reddish-brown
coloration when spotted with silver nitrate on a white slab.
[898] Pattison Muir on “Certain Bismuth Compounds,” _Journ. Chem. Soc._,
vol. i. p. 659, 1879.
Another very generally applicable volumetric method for bismuth has been
proposed by Mr. Muir.[899] This depends on the fact (observed by Sonchay
and Leussen),[900] that normal bismuth oxalate splits up on boiling into
a basic oxalate of the composition Bi₂O₃2C₂O₃ + OH₂, but slightly
soluble in nitric acid. The process is performed by precipitating the
bismuth by excess of oxalic acid, dissolving the precipitate (first
purified from free oxalic acid) in dilute hydrochloric acid, and lastly,
titrating by permanganate. The absence of free hydrochloric acid before
precipitating must be insured.
[899] _Ibid._, 1877.
[900] _Ann. Chem. Pharm._, vol. cv. p. 245.
4. SILVER.
§ 819. =Silver= = 108; specific gravity, 10·5; fusing-point, 1023°
(1873° F.).--Silver, as separated in analysis, is either a very white,
glittering, metallic bead, or a dull grey powder. It does not lose
weight on ignition, and is soluble in dilute nitric acid.
§ 820. =Chloride of Silver=, AgCl = 143·5; specific gravity, 5·552; Ag,
75·27 per cent., Cl, 24·73 per cent., is a dense, white, curdy
precipitate, when produced in the wet way. It is very insoluble in
water, dilute nitric acid, and dilute sulphuric acid; in many warm
solutions (especially aqueous solutions of the chlorides generally), the
alkaline and alkaline-earthy nitrates, and tartaric acid solutions, the
silver is dissolved to an appreciable extent, but deposited again on
diluting and cooling. The complete solvents of chloride of silver
are--ammonia, cyanide of potassium, and hyposulphite of soda. Chloride
of silver cannot be fused at a high heat without some slight loss by
volatilisation; on coal in the R.F., it fuses very easily to a globule.
It can with soda be reduced to metal, and can also readily be reduced by
ignition in a current of hydrogen, carbon oxide, or carburetted hydrogen
gas.
§ 821. =Sulphide of Silver=, Ag₂S = 248; specific gravity, 7·2; Ag, 87·1
per cent., S, 12·9 per cent., when prepared in the wet way, is a black
precipitate, insoluble in water, dilute acids, and alkaline sulphides.
If ignited in hydrogen it may be reduced to the metallic state; it is
soluble in nitric acid, with separation of sulphur.
§ 822. =Preparations of Silver used in Medicine and the Arts.=
(1) =Medicinal Preparations=:--
=Nitrate of Silver=, AgNO₃; Ag, 63·51 per cent., N₂O₅, 36·49 per cent.
This salt is either sold crystallised in colourless rhombic prisms, or
in the form of small white pencils or sticks. It gives the reactions for
silver and nitric acid, and stains the skin black. 100 parts, dissolved
in distilled water, should give, with hydrochloric acid, a precipitate
which, when washed and dried, weighs 83·4 parts. The silver is, however,
far more quickly estimated by the blowpipe than in the wet way. One grm.
fused in a cavity on charcoal should give a little globule of metallic
silver, weighing about ·6351 grm. The chief adulterations of this
substance are copper, lead, and nitrate of potash. If all the silver is
precipitated by hydrochloric acid, carefully filtered off, and the
filtrate evaporated to dryness, any residue will denote adulteration or
impurity.
=Argenti Oxidum=, =Oxide of Silver=, Ag₂O = 232; Ag, 93·19 per cent.--A
dark olive-brown powder, soluble in ammonia and nitric acid. By ignition
it readily yields metallic silver. The P.B. directs that 29 grains of
the oxide should yield 27 of metallic silver.
=Nitrate of Silver and Potash= (=Argentum nitricum cum kali nitrico=),
AgNO₃ + KNO₃.--This preparation is in most of the pharmacopœias,
Austrian, German, Danish, Swedish, Russian, Swiss, and the British; it
is directed by the B.P. to be composed of 1 part of silver nitrate and
1 part of potassic nitrate fused together. A “toughened silver nitrate”
is made by fusing together potassic nitrate 5, silver nitrate 95. Mild
caustic points are used by oculists by fusing 1 of silver nitrate with
2, 3, 3½, and 4 parts of potassic nitrate.
(2) =Silver in the Arts.=--The uses of the metal in coinage, articles
for domestic purposes, for ornament, &c., are too well known to require
enumeration. The only forms in which silver is likely to give rise to
accident are the salts used in medicine, photography, in the dyeing of
hair, and in the manufacture of marking inks.
=Hair-dyes.=--About one-half of the hair-dyes in use are made with
nitrate of silver. The following are only a few of the recipes:--
=Aqua Orientalis.=--Grain silver 2 drms., nitric acid 1 oz., steel
filings 4 drms., distilled water 1½ oz.--the whole finally made up to 3½
fluid ozs., and filtered.
=Argentan Tincture.=--Nitrate of silver 1 drachm, rose water 1 fluid
oz., sufficient nitrate of copper to impart a greenish tint.
=Eau d’Afrique.=--Two solutions--one of nitrate of silver, the other of
potash, containing ammonium sulphide.
The photographer uses various salts of silver, the chief of which
are--the nitrate, iodide, bromide, cyanide, and chloride of silver.
=Marking Inks.=--Some of the more important recipes for marking ink are
as follows:--
Nitrate of silver 1·0 part, hot distilled water 3·6 parts, mucilage,
previously rubbed with sap-green, 1·0 part. With this is sold a
“pounce,” or preparation consisting of a coloured solution of sodic
carbonate. Another preparation is very similar, but with the addition of
ammonia and some colouring matter, such as indigo, syrup of buckthorn,
or sap-green. A third is made with tartaric acid and nitrate of silver,
dissolved in ammonia solution, and coloured.
=Redwood’s Ink= consists of equal parts of nitrate of silver and
potassic bitartrate, dissolved in ammonia, with the addition of archil
green and sugar; according to the formula, 100 parts should equal 16·6
of silver nitrate.
=Soubeiran’s Ink= is composed of cupric nitrate 3, argentic nitrate 8,
sodic carbonate 4, and the whole made up to 100 parts, in solution of
ammonia. In one of Mr. Reade’s inks, besides silver, an ammoniacal
solution of a salt of gold is used.
§ 823. =Medicinal Dose of Silver Compounds.=--The nitrate and the oxide
of silver are given in doses from ·0162 to ·1296 grm. (¼ grain to 2
grains). Anything like ·1944 to ·2592 grm. (3 or 4 grains) would be
considered a large, if not a dangerous dose; but nothing definite is
known as to what would be a _poisonous_ dose.
§ 824. =Effects of Nitrate of Silver on Animals.=--Nitrate of silver is
changed into chloride by the animal fluids, and also forms a compound
with albumen. Silver chloride and silver albumenate are both somewhat
soluble in solutions containing chlorides of the alkalies, which
explains how a metallic salt, so very insoluble in water, can be
absorbed by the blood.
The action of soluble salts of silver on animals has been several times
investigated. There appears to be some difference between its effects on
warm and cold-blooded animals. In frogs there is quickly an exaltation
of the functions of the spinal cord, tetanic convulsions appear, similar
to those induced by strychnine; later, there is disturbance of the
respiration and cessation of voluntary motion.
The first symptoms with dogs and cats are vomiting and diarrhœa;
muscular weakness, paralysis, disturbance of the respiration, and weak
clonic convulsions follow. Rouget, as well as Curci, considers that the
action of silver is directed to the central nervous system; there is
first excitement, and then follows paralysis of the centres of
respiration and movement. Death occurs through central asphyxia.
According to the researches of F. A. Falck, subcutaneous injections of
silver nitrate into rabbits cause a fall of temperature of 6·7° to
17·6°, the last being the greatest fall which, in his numerous
researches on the effect of poisons on temperature, he has seen.
Chronic poisoning, according to the experiments of Bogoslowsky on
animals, produces emaciation, fatty degeneration of the liver, kidneys,
and also of the muscles--a statement confirmed by others.
§ 825. =Toxic Effects of Silver Nitrate in Man=--(1) =Acute
Poisoning.=--This is very rare. Orfila relates an attempt at suicide;
but most of the cases have been accidental, and of these, in recent
times, about five are recorded, mostly children. The accident is usually
due to the application of the solid nitrate to the throat, as an
escharotic, the stick breaking or becoming detached, and being
immediately swallowed; such an accident is related by Scattergood.[901]
A piece of silver nitrate ¾ inch long, slipped down the throat of a
child, aged fifteen months--vomiting immediately occurred, followed by
convulsions and diarrhœa; chloride of sodium was administered, but the
child died in six hours. In other cases paralysis and an unconscious
state has been observed.
[901] _Brit. Med. Journal_, May 1871.
(2) =Chronic Poisoning.=--Salts of silver taken for a long period cause
a peculiar and indelible colour of the skin, the body becomes of a
greyish-blue to black colour, it begins first around the nails and
fingers, then patches of a similar hue appear in different parts of the
body, and gradually coalesce, being most marked in those parts exposed
to the light. The colour is not confined to the outer skin, but is also
seen in the mucous membranes. There is also a slight inflammation of the
gums, and a violet line around their edge. Ginpon observed this line
after two months’ treatment of a patient by silver nitrate; the whole
quantity taken being 3·9 grms. (about 60 grains). The peculiar colour of
the skin is only seen after large dose; after 8 grms. taken in divided
doses Chaillon could not observe any change, but after 15 grms. had been
taken it was evident. So also Riemer has recorded a case, in which,
after a year’s use of silver nitrate (total quantity 17·4 grms.) a
greyish-black colour of the face was produced, and, when nearly double
the quantity had been taken, the colour had invaded the whole body.
§ 826. =Post-mortem Appearances.=--In the acute case recorded by
Scattergood, the mucous membranes of the gullet, of the great curvature
of the stomach, and parts of the duodenum and jejunum were eroded, and
particles of curd-like silver chloride adhered to the mucous membrane.
In the case recorded by Riemer of the long-continued use of silver
nitrate, the serous and mucous membranes were coloured dark; the choroid
plexus was of a blue-black; the endocardium, the valves of the heart,
and the aorta pale to dark grey, as well as the rest of the vessels; the
colouring was confined to the intima. The liver and kidney also showed
similar pigmentation. The pigment (probably metallic silver) was in the
form of very fine grains, and, as regards the skin, was situate under
the _rete Malpighia_ in the upper layer of the corium, and also in the
deeper connective tissue and in the sweat glands. Liouville has also
found the kidneys of a woman similarly pigmented, who took silver
nitrate daily for 270 days, in all about 7 grms., five years before her
death.
§ 827. =Detection and Estimation of Silver.=--The examination of the
solid salts of silver usually met with (viz., the nitrate, bromide,
iodide, cyanide, and chloride) is most speedy by the dry method on
charcoal; in this way in less than 120 seconds any practical chemist
could identify each compound. The nitrate, bromide, iodide, and
cyanide, all, if ignited on charcoal, yield buttons of metallic
silver--deflagration, bromine vapours, iodine vapours, and cyanogen
vapours being the respective phenomena observed. Chloride of silver
fuses to a pearl-grey, brown, or black globule on charcoal, according to
its purity; but is only in the R.F. gradually reduced to metal. With
soda, or fused in hydrogen or coal gas, the reduction is rapid enough.
=Nitrate of Silver in solution= might be identified by a very large
number of tests, since it forms so many insoluble salts. In practice one
is, however, satisfied with three tests, viz.: (1) A curdy precipitate
of chloride, on the addition of hydrochloric acid or alkaline chlorides,
soluble only in ammonia, cyanide of potassium, or hyposulphite of soda;
(2) a yellow precipitate, but little soluble in ammonia, on the addition
of iodide of potassium; and (3) a blood-red precipitate on the addition
of chromate of potash.
The separation of silver from the contents of the stomach is best
ensured by treating it with cyanide of potassium; for, unless a very
large quantity of silver nitrate has been taken, it is tolerably certain
that the whole of it has passed into chloride, and will, therefore, not
be attacked easily by acids. The contents of the stomach, then, or the
tissues themselves, are placed in a flask and warmed for some time with
cyanide of potassium, first, if necessary, adding ammonia. The fluid is
separated from the solid matters by subsidence (for an alkaline fluid of
this kind will scarcely filter), and then decomposed by hydrochloric
acid in excess. The flask containing this fluid is put on one side in a
warm place, and the clear fluid decanted from the insoluble chloride.
The latter is now collected on a filter, well washed with hot water, and
then dried and reduced on charcoal; or it may be put in a little
porcelain crucible with a rod of zinc and a few drops of hydrochloric
acid. The silver is soon deposited, and must be washed with water, then
with sulphuric acid. By the aid of a wash-bottle the particles of silver
are now collected on a small filter, again washed, and on the moist mass
a crystal of nitrate of potash and a little carbonate of soda laid. The
whole is then dried, and all the filter cut away, save the small portion
containing the silver. This small portion is now heated on charcoal
until a little button of pure silver is obtained, which may first be
weighed, then dissolved in nitric acid, and tested by the methods
detailed.
In a similar way hair, suspected of being dyed with silver, can be
treated with chlorine gas, and the chloride dissolved in potassic
cyanide.
Spots on linen, and, generally, very small quantities of silver, may be
detected by a simple galvanic process:--The substance is treated with
solution of cyanide of potassium, and submitted to a weak galvanic
current, using for the negative plate a slip of copper, for the
positive, platinum; the silver is deposited on the former.
5. MERCURY.
§ 828. =Mercury=, Hg = 200; specific gravity, 13·596; boiling-point,
350° (662° F.); it becomes solid at -39·4 (-39 F.). This well known and
familiar fluid metal evaporates and sublimes to a minute extent at all
temperatures above 5°.
When precipitated or deposited in a finely divided state, the metal can
be united into a single globule only if it is fairly pure; very slight
_fatty_ impurities especially will prevent the union. It is insoluble in
hydrochloric acid, soluble to a slight extent in dilute cold sulphuric
acid, and completely soluble in concentrated sulphuric and in nitric
acids. It combines directly with chlorine, bromine, and iodine, which,
in presence of free alkali, readily dissolve it. It is unalterable at
100°, and, when exposed to a high temperature, sublimes unchanged.
=Mercurous Chloride= (Calomel, HgCl = 235·5; specific gravity, 7·178;
subliming temperature, 111·6°; Hg, 84·94 per cent., Cl, 15·06 per
cent.), when prepared in the wet way is a heavy white powder, absolutely
insoluble in cold, but decomposed by boiling water. It may be converted
into the mercuric chloride by chlorine water and aqua regia. Chloride of
ammonium, potassium, and sodium, all decompose calomel into metallic
mercury and mercuric chloride. It is easily reduced to metal in a tube
with soda, potash, or burnt magnesia.
§ 829. =Sulphide of Mercury= (HgS, Hg, 86·21 per cent., S, 13·79 per
cent.) is a black powder, dissolving in nitromuriatic acid, but very
insoluble in other acids or in water. It is also insoluble in alkaline
sulphides, with the exception of potassic sulphide.
§ 830. =Medicinal Preparations of Mercury.=--Mercury in the liquid state
has been occasionally administered in constipation; its internal use is
now (or ought to be) obsolete. Gmelin has found samples contaminated
with metallic bismuth--a metal which only slightly diminishes the
fluidity of mercury; the impurity may be detected by shaking the mercury
in air, and thus oxidising the bismuth. Mercury may also contain various
mechanical impurities, which are detected by forcing the metal by means
of a vacuum pump through any dense filtering substance. Tin and zinc may
be dissolved out by hydrochloric acid, and all fixed impurities (such as
lead and bismuth) are at once discovered on subliming the metal.
=Mercury and Chalk= (=Hydrargyrum cum creta=).--Mercury, 33·33 per
cent.; chalk, 66·67.
=Blue Pill= (=Pilula hydrargyri=).--Mercury in a finely divided state,
mixed with confection of roses and liquorice root; the mercury should be
in the proportion of 33·33 per cent.[902]
[902] The chemical composition of blue pill varies according to its age.
Harold Senier has made a careful series of analyses, with the following
result (_Pharm. Journ._, Feb. 5, 1876):--
+----+------------+---------+---------+-----------+--------+---------+
| | Age. |Metallic |Mercuric | Mercurous | Ash. | Organic |
| | |Mercury. | Oxide. | Oxide. | | Matter. |
+----+------------+---------+---------+-----------+--------+---------+
| 1 | 18 hours, | 32·49 | none. | a trace. | 1·20 | 66·31 |
| 2 | 3 weeks, | 32·26 | ·09 | ·25 | 1·20 | 66·20 |
| 3 | 3 months, | 32·60 | ·24 | ·62 | 1·18 | 66·36 |
| 4 | 3 „ | 31·15 | ·44 | 1·60 | 1·12 | 65·69 |
| 5 | 6 „ | 32·44 | ·50 | ·80 | 1·70 | 64·56 |
| 6 | 14 „ | 29·86 | ·98 | 2·60 | 1·20 | 65·36 |
| 7 | 19 „ | 31·59 | ·50 | 2·50 | 1·00 | 64·41 |
| 8 | 2 years, | 28·40 | 1·80 | 4·22 | 2·10 | 63·48 |
| 9 | (?) | 30·23 | 1·06 | 3·24 | 1·05 | 64·44 |
+----+------------+---------+---------+-----------+--------+---------+
=Mercury Plaster= (=Emplastrum hydrargyri=).--Made with mercury, olive
oil, sulphur, and lead plaster; it should contain Hg, 33 per cent.;
sulphur, 18 per cent.
=Ammoniac and Mercury Plaster= (=Emplastrum ammoniaci cum
hydrargyro=).--Gum, ammonia, mercury, olive oil, and sulphur; it should
contain 20 per cent. of Hg, and ·1 per cent. of sulphur.
=Mercurial Ointment= (=Unguentum hydrargyri=).--Mercury mixed with lard
and suet, the strength should be nearly 50 per cent. mercury; commercial
samples often contain as little as 38 per cent.
=Compound Mercury Ointment= (=Unguentum hydrargyri compositum=).--Made
with ointment of mercury, yellow wax, olive oil, and camphor; it should
contain 22·2 per cent. Hg.
=Liniment of Mercury= (=Linimentum hydrargyri=) is made of mercurial
ointment, solution of ammonia, and liniment of camphor; it contains
about 16½ per cent. of mercury.
=Mercurial Suppositories= (=Suppositoria hydrargyri=).--Composed of
ointment of mercury and oil of theobroma. Each suppository should weigh
15 grains and contain ⅓ of its weight of mercurial ointment.
=Acetate of Mercury= (=Mercurous acetate=) is not contained in the B.P.,
but is officinal on the Continent. It is a salt occurring in white
micaceous scales, soluble in 133 parts of cold water, giving the
reactions of acetic acid and mercury, and very readily decomposed.
=Mercuric Ethyl Chloride= (=Hydrargyrum æthylo-chloratum=) is used as a
medicine on the Continent. It occurs in white, glittering, crystalline
scales, which take on pressure a metallic appearance, and possess a
peculiar ethereal odour; it is but little soluble in water and ether,
with difficulty in cold alcohol, but copiously soluble on boiling, and
depositing crystals on cooling. It sublimes at about 40° without
residue; on quick heating it burns with a weak flame, developing a
vapour of metallic taste and unpleasant odour. It gives no precipitate
with silver nitrate, nor with albumen.
=Corrosive Sublimate= (=Mercuric chloride=), HgCl₂ = 271; Hg, 73·8 per
cent., Cl, 26·1 per cent.--In commerce this salt occurs in transparent,
heavy, colourless masses, which have a crystalline fracture; if placed
in the subliming cell described at p. 258, it sublimes at about 82·2°
(180° F.), and melts at higher temperatures. The sublimate is generally
in groups of plates drawn to a point at both ends, in crystalline
needles, or in octahedra with a rectangular base. It dissolves in 16
parts of cold water and about 3 of boiling, and is very soluble in
solutions of the alkaline chlorides; it dissolves also in ether, and can
be, to a great extent, withdrawn from aqueous solutions by this agent.
Alcohol dissolves nearly one-third its weight of the salt, and its own
weight when boiling. It combines with albumen; gives, when in solution,
a precipitate of mercuric oxide when tested with solution of potash; a
white precipitate with ammonia; a scarlet with iodide of potassium; and
a black precipitate of finely divided mercury with protochloride of tin.
If a crystal (when placed in the subliming cell) gives a crystalline
sublimate at about the temperature mentioned, and this sublimate becomes
of a red colour when treated with a droplet of iodide of potassium, it
can be no other substance than corrosive sublimate.
=Solution of Perchloride of Mercury= (=Liquor hydrargyri perchloridi=)
is simply 10 grains of perchloride of mercury and chloride of ammonium
in a pint of water; 100 c.c. therefore should contain 114 mgrms.
corrosive sublimate.
=Yellow Mercurial Lotion= (=Lotio hydrargyri flava=).--Perchloride of
mercury, 18 grains, mixed with 10 ounces of solution of lime.
=Calomel=[903] (=Hydrargyri subchloridum=).--The properties of calomel
have been already described. It sometimes contains as an impurity
corrosive sublimate, which may be dissolved out by ether. Carbonate of
lead, sulphate, and carbonate of baryta, gum, and starch, are the usual
adulterants mentioned. If on the application of heat calomel entirely
sublimes, it must be free from the substances enumerated.
[903] It would appear that in America a cosmetic is in use, consisting
of calomel mixed into a paste with water.--_Vide_ “A Dangerous
Cosmetic,” by C. H. Piesse, _Analyst_ (25), 1878, p. 241.
=Oleate of Mercury= (=Hydrargyri oleatum=) is composed of 1 part of
yellow oxide and 9 parts of oleic acid.
=Black Mercurial Lotion= (=Lotio hydrargyri nigra=).--Calomel, 30
grains, mixed with 10 fluid ounces of lime-water.
=Compound Pill of Subchloride of Mercury.=--Calomel and sulphurated
antimony, each 1 ounce, guiac resin 2 ounces, castor-oil 1 fluid ounce.
One grain (·0648 grm.) of calomel, and the same quantity of antimony
sulphide, are contained in every 5 grains (324 mgrms.) of the pill mass,
_i.e._, calomel 20 per cent.
=Ointment of Subchloride of Mercury= (=Unguentum hydrargyri
subchloridi=).--Calomel mixed with benzoated lard; strength about 1 :
6½.
=White Precipitate= (=Hydrargyrum ammoniatum=, NH₂HgCl).--A white, heavy
powder, subliming by heat without residue, and insoluble in water,
alcohol, and ether. With soda, it yields a metallic sublimate. When
boiled with potash, ammonia is evolved, the yellow oxide of mercury
formed, and chloride of potassium passes into solution. It should
contain 79·5 per cent. of mercury.
The fusible white precipitate of the pharmacopœia of the Netherlands
does not appear to be of constant composition, varying between 69·4 to
65·6 per cent. of mercury.[904] It melts on heating, and leaves as a
residue chloride of sodium.
[904] Hirsch, _Die Prüfung der Arzeneimittel_.
Commercial white precipitate is frequently adulterated; Barnes has found
carbonates of lead and lime, the latter to the extent of nearly 2 per
cent.[905] Calomel, according to Nickles,[906] has been substituted for
white precipitate, but this was several years ago. The methods for
detection are obvious.
[905] _Proceed. Brit. Pharm. Conf._, 1867, p. 10.
[906] _Journ. Pharm. et Chim._, le Série, 1858, vol. viij. p. 399.
=Ointment of Ammoniated Mercury= (=Unguentum hydrargyri ammoniati=).--1
part of ammoniated mercury mixed with 9 parts of simple ointment.
=Red Iodide of Mercury= (=Hydrargyrum iodidum rubrum=, HgI₂).--A
crystalline powder of a scarlet colour, becoming yellow on gentle
heating. It is very insoluble in water, one part requiring from 6000 to
7000 parts; soluble in 130 parts of cold, 150 of hot alcohol; and
dissolving freely in ether, or in aqueous solution of iodide of
potassium.
=Ointment of Red Iodide of Mercury= (=Unguentum hydrargyri iodidi
rubri=).--16 grains of the substance mixed with an ounce of simple
ointment.
=Green Iodide of Mercury= (=Hydrargyri iodidum viride=, HgI).--A dingy,
greenish-yellow powder, darkening on exposure to light, and easily
decomposed into the red iodide.
=Red Oxide of Mercury= (=Hydrargyri oxidum rubrum=), HgO = 216; Hg,
92·12 per cent.; specific gravity, 11 to 11·3; small, red, shining,
crystalline scales, very insoluble in water, requiring about 20,000
parts; entirely soluble in hydrochloric acid. By a heat below redness it
may be volatilised, and at the same time decomposed into mercury and
oxygen. Its principal impurity is nitric acid, readily detected by the
usual tests, or by heating in a test-tube, when, if nitric acid is
present, orange vapours will be evolved. Fixed red powders (such as
brick-dust and minium) are detected by being left as a residue, after
the application of heat sufficient to volatilise the mercury. An
ointment (strength 1 : 8) is officinal.
=Sulphate of Mercury.=--A white crystalline powder, decomposed by water
into the very insoluble basic salt of mercury, known as _Turbith
mineral_, HgSO₄2HgO.
=Turbith, or Turpeth, Mineral= is contained in the French pharmacopœia,
HgSO₄2HgO; Hg, 82·4 per cent.; specific gravity, 8·319. It requires for
solution 2000 parts of cold, and 600 of boiling water; but dissolves
with tolerable ease in hydrochloric acid.
=The Sulphide of Mercury=, known in commerce under the name of _Ethiops
mineral_, is officinal in France, the Netherlands, and Germany. Its
properties have been already described. The German and Dutch
pharmacopœias require in it 50, the French only 33⅓ per cent. of
metallic mercury.
=Hahnemann’s Soluble Mercury= (=Hydrargyrum solubile Hahnemanni=) is
officinal in the Dutch pharmacopœia. As found in commerce it contains
metallic mercury, nitric acid, and ammonia. The mercury should be in the
proportion of 86·33 per cent., the ammonia 2·44 per cent.
=Crystallised Nitrate of Mercury= (=Hydrargyrum nitricum oxidulatum=) is
officinal in the pharmacopœias of Germany, Switzerland, and France. The
salt is in white crystals, giving the reactions of nitric acid and
mercury, decomposed by the addition of water, but fully soluble in
water, if first moistened with nitric acid. The formula of the neutral
salt is Hg2NO₃HgO2H₂O, which requires 69·4 per cent. of mercury. An acid
solution of mercuric nitrate is officinal.
=An Ointment of Nitrate of Mercury= (=Unguentum hydrargyri nitratis=)
(often called citrine ointment) is contained in the B.P.; it is made
with 4 parts of mercury, nitric acid 12, lard 15, olive oil, 32; the
strength is about 1 in 15½.
=A Chloride of Mercury and Quinine= exists in commerce, prepared by
mixing 1 part of corrosive sublimate in solution with 3 parts of quinine
chloride, evaporating, and crystallising.
=Cyanide of Mercury=, HgCy, is contained in the French pharmacopœia. It
occurs in small, colourless, prismatic crystals, easily soluble in
water. If to the solution chloride of tin be added, a black precipitate
of reduced metal and stannous oxide is thrown down, and the odour of
prussic acid is developed.
=Mercuric Sulphide= (=Sulphide of Mercury=, =Cinnabar=, =Vermilion=) is
officinal in Germany, the Netherlands, and France; HgS = 232; specific
gravity, solid, 8·2; Hg, 86·21 per cent., O, 13·79 per cent. For
medicinal purposes it is made artificially. It is a beautiful red
powder, insoluble in all alkaline and all acid liquids, with the
exception of aqua regia. The solution gives the reactions of a sulphide
and mercury. On heating, it must burn away entirely without residue;
adulterations or impurities are--minium, lead, copper, and other metals.
The detection of minium is conveniently executed in the dry way. Pure
cinnabar, when heated in a matrass, gives a black sublimate, which
becomes red on friction. If minium is present, sulphide of lead remains
as a residue, and may be recognised on coal; the same remark applies to
sulphide of antimony. If it be desired to take the percentage of mercury
in cinnabar, equal parts of oxalate and cyanide of potassium should be
well mixed with the cinnabar, and heated in the bent tube described at
p. 654; by this means the whole of the metallic mercury is readily
obtained.[907]
[907] Dr. Sutro has published a case (quoted by Taylor), in which the
vapour of vermilion, applied externally, produced poisonous symptoms;
yet, according to Polak, the Persians inhale it medicinally, smoking it
with tobacco, catechu, mucilage, &c., the only bad effect being an
occasional stomatitis.--Eulenberg, _Gewerbe Hygiene_, p. 741.
§ 831. =Mercury in the Arts.=--The use of mercury in the arts is so
extensive, that any one in analytical practice is almost certain
occasionally to meet with cases of accidental poisoning, either from the
vapour[908] or some of its combinations.
[908] A singular case is cited by Tardieu (_Étude méd.-légal sur
l’Empoisonnement_), in which a man, supposing he had some minerals
containing gold, attempted the extraction by amalgamation with mercury.
He used a portable furnace (for the purpose of volatilising the mercury)
in a small room, and his wife, who assisted him, suffered from a very
well-marked stomatitis and mercurial eruption.
Quicksilver is used in the extraction of gold, the silvering of mirrors,
the construction of barometers, and various scientific instruments and
appliances; also for the preservation of insects, and occasionally for
their destruction.[909] An alloy with zinc and cadmium is employed by
dentists for stopping teeth; but there is no evidence that it has been
at all injurious, the mercury, probably, being in too powerful a state
of combination to be attacked by the fluids in the mouth.[910] Cinnabar
has also been employed to give a red colour to confections, and it may
be found in tapers, cigarette papers, and other coloured articles. The
nitrate of mercury in solution finds application in the colouring of
horn, in the etching of metals, in the colouring of the finer sorts of
wool, and in the hat manufacture.
[909] Forty-three persons were salivated from fumigating rooms with
mercury for the purpose of destroying bugs (Sonnenschein’s _Handbuch_,
p. 96).
[910] More danger is to be apprehended from the vulcanised rubber for
artificial teeth; and, according to Dr. Taylor, accidents have occurred
from the use of such supports or plates.
The sulphocyanide of mercury gives, when burnt, a most abundant ash, a
fact utilised in the toy known as Pharaoh’s serpent; the products of
combustion are mercurial vapours and sulphurous anhydride. That the
substance itself is poisonous, is evident from the following
experiment:--·5 grm. was given to a pigeon without immediate result; but
ten hours afterwards it was indisposed, refused its food, and in forty
hours died without convulsions.[911]
[911] Eulenberg, _Op. cit._, p. 472.
§ 832. The more Common Patent and Quack Medicines containing Mercury.
=Mordant’s Norton’s Drops.=--This patent medicine is a mixture of
the tincture of gentian and ginger, holding in solution a little
bichloride of mercury, and coloured with cochineal.
=Solomon’s Anti-impetigines= is a solution of bichloride of mercury,
flavoured and coloured.
=Poor Man’s Friend.=--An ointment of nitrate of mercury.
=Brown’s Lozenges.=--Each lozenge contains ½ grain of calomel, and
3½ grains of resinous extract of jalap; the rest is white sugar and
tragacanth.
=Ching’s Worm Lozenges.=--Each lozenge contains 1 grain of calomel;
the rest white sugar and tragacanth, with saffron as a colouring
matter.
=Storey’s Worm Cakes.=--Each cake 2 grains of calomel, 2 grains of
cinnabar, 6 grains of jalap, 5 grains of ginger, and the remainder
sugar and water.
=Wright’s Pearl Ointment= is said to be made up of 8 ozs. of white
precipitate rubbed to a cream in 1 pint of Goulard’s extract, and to
the mixture is added 7 lbs. of white wax and 10 lbs. of olive oil.
=Keyser’s Pills.=--The receipt for these pills is--red oxide of
mercury 1½ oz., distilled vinegar (dilute acetic acid) 1 pint;
dissolve, add to the resulting solution manna 2 lbs., and triturate
for a long time before the fire, until a proper consistence is
attained; lastly, divide the mass into pills of 1½ grain each.
=Mitchell’s Pills.=--Each pill contains aloes ·8 grain, rhubarb 1·6
grain, calomel ·16 grain, tartar emetic ·05 grain.
Many =Antibilious Pills= will be found to contain calomel, a few
mercury in a finely divided state.
§ 833. =Mercury in Veterinary Medicine.=--Farmers and farriers use the
ointment (_blue ointment_) to a dangerous extent, as a dressing for the
fly, and wholesale poisoning of sheep has been in several instances the
consequence.[912] Ethiops mineral and Turpeth mineral are given to dogs
when affected by the distemper, worms, or the mange. Mercury, however,
is not very frequently given to cattle by veterinary surgeons, ruminants
generally appearing rather susceptible to its poisonous effects.
[912] Twenty-five tons of blue ointment are said to have been sold to
farmers by a druggist in Boston, Lincolnshire, in the course of a single
year.--Taylor’s _Medical Jurisprudence_, vol. i. p. 279.
§ 834. =Medicinal and Fatal Dose--Horses.=--Cinnabar 14·2 grms, (½ oz.),
calomel 14·2 grms. (½ oz.) or more, corrosive sublimate ·13 to ·38 grm.
(2 to 6 grains), and as much as 1·3 grm. (20 grains) have been given in
farcy.
=Cattle.=--Mercury with chalk 3·8 to 11·6 grms. (1 to 3 drms.), calomel
3·8 to 7·7 grms. (1 to 2 drms.) for worms; ·65 to 1·3 grm. (10 to 20
grains) as an alterative; Ethiops mineral, 7·7 to 15·5 grms. (2 to 4
drms.).
=Dogs.=--Ethiops or Turpeth mineral ·13 to 1·3 grm. (2 to 20 grains),
according to the size.
=Fowls.=--Mercury and chalk are given in fractions of a grain.
=Hogs= are also treated with mercury and chalk; the dose usually given
does not exceed ·32 grm. (5 grains).
It may be remarked that many of the doses quoted appear very large; the
writer cannot but consider that 20 grains of corrosive sublimate
administered to a horse would be more likely to kill the animal than to
cure the disease.
=Man.=--Corrosive sublimate has been fatal in a dose so small as ·19
grm. (3 grains); white precipitate has caused dangerous symptoms in
doses of from 1·9 to 2·6 grm. (30 to 40 grains); the cyanide of mercury
has killed a person in a dose of ·64 grm. (10 grains)--_Christison_; and
Turpeth mineral has proved fatal in doses of 2·6 grms. (40 grains).
Other preparations of mercury have also been fatal, but a doubt has
existed as to the precise quantity. Sometimes, also, there is probably a
chemical change in the substance, so that it is impossible to state the
fatal dose. For example, it is well known that calomel, under the
influence of alkaline chlorides, can be converted into the bichloride--a
fact which probably explains the extensive corrosive lesions that have
been found after death from large doses of calomel.
§ 835. =Poisoning by Mercury--Statistics.=--In the Registrar-General’s
death returns for the ten years ending 1892, it appears that in England
the deaths from mercurial poisoning[913] were 40 males, 19 females; of
these, 16 males and 18 females were cases of suicide, the remainder were
referred to accident.
[913] The deaths are registered under the term “_Mercury_,” but the
majority are poisonings by “_Corrosive Sublimate_.”
The effects of the different compounds of mercury may be divided into
two groups, viz., (1) Those caused by the finely divided metal and the
non-corrosive compounds; (2) the effects caused by the corrosive
compounds.
§ 836. (1) Effects of Mercurial Vapour, and of the Non-Corrosive
Compounds of Mercury.
(_a_) =Vegetable Life.=--Priestly and Boussingault have shown that
plants under a glass shade in which mercury is exposed in a saucer,
first exhibit black spots on the leaves; ultimately, the latter blacken
entirely, and the plants die.
(_b_) =Animal Life.=--Mercury in the form of vapour is fatal to animal
life, but it is only so by repeated and intense application.
Eulenberg[914] placed a rabbit under a large glass shade, and for four
days exposed it daily for two hours to the volatilisation of 2 grms. of
mercury on warm sand; on the sixth and seventh day 1·5 grm. was
volatilised. On the fifteenth day there was no apparent change in the
aspect of the animal; 5 grms. of mercury were then heated in a retort,
and the vapour blown in at intervals of ten minutes. Fourteen days
afterwards the gums were reddened and swollen, and the appetite lost;
the conjunctivæ were also somewhat inflamed. The following day these
symptoms disappeared, and the animal remained well.
[914] _Op. cit._, p. 728.
In another experiment 20 grms. of mercury were volatilised, and a rabbit
exposed to the vapour under a small glass shade. The following day the
conjunctivæ were moist and reddened; two days afterwards 10 grms. of
mercury were volatilised in the same way; and in two days’ interval
other 10 grms. were volatilised in three-quarters of an hour. There was
no striking change noticeable in the condition of the animal, but
within forty-eight hours it was found dead. The cause of death proved to
be an extravasation of blood at the base of the brain. The bronchia were
reddened throughout, and the lungs congested. Mercury, as with man, is
also readily absorbed by the broken or unbroken skin; hence thousands of
sheep have been poisoned by the excessive and ignorant external
application of mercurial ointment as a remedy against the attacks of
parasites. The sheep become emaciated, refuse food, and seem to be in
pain, breathing with short quick gasps.
In experiments on rabbits, dogs, and warm-blooded animals generally,
salivation and stomatitis are found to occur as regularly as in man; so
also in animals and man, paralytic and other nervous affections have
been recorded.
§ 837. (_c_) =Effects on Man.=--In 1810[915] an extraordinary accident
produced, perhaps, the largest wholesale poisoning by mercurial vapour
on record. The account of this is as follows:--H.M.S. “Triumph,” of
seventy-four guns, arrived in the harbour of Cadiz in the month of
February 1810; and in the following March, a Spanish vessel, laden with
mercury for the South American mines, having been driven on shore in a
gale, was wrecked. The “Triumph” saved by her boats 130 tons of the
mercury, and this was stowed on board. The mercury was first confined in
bladders, the bladders again were enclosed in small barrels, and the
barrels in boxes. The heat of the weather, however, was at this time
considerable; and the bladders, having been wetted in the removal from
the wreck, soon rotted, and mercury, to the amount of several tons, was
speedily diffused as vapour through the ship, mixing more or less with
the bread and the other provisions. In three weeks 200 men were affected
with ptyalism, ulceration of the mouth, partial paralysis, and, in many
instances, with diarrhœa. The “Triumph” was now ordered to Gibraltar,
the provisions were removed, and efforts were made to cleanse the
vessel. On restowing the hold, every man so employed was salivated. The
effects noted were not confined to the officers and ship’s company, for
almost all the stock died from the fumes--mice, cats, a dog, and even a
canary bird shared the same fate, though the food of the latter was kept
in a bottle closely corked up. The vapour was very deleterious to those
having any tendency to pulmonic affections. Three men, who had never
complained before they were saturated with mercury, died of phthisis;
one, who had not had any pulmonic complaint, was left behind at
Gibraltar, where his illness developed into a confirmed phthisis. Two
died from gangrene of the cheeks and tongue. A woman, confined to bed
with a fractured limb, lost two of her teeth; and many exfoliations of
the jaw took place.
[915] “An Account of the Effect of Mercurial Vapours on the Crew of His
Majesty’s Ship ‘Triumph,’ in the year 1810.”--_Phil. Trans._, 113,
1823.
Accidents from the vapour of mercury, quite independently of its
applications in the arts, have also occurred, some of them under curious
circumstances; such, for example, is the case mentioned in the footnote
to p. 639. Witness, again, a case mentioned by Seidel,[916] in which a
female, on the advice of an old woman, inhaled for some affection or
other 2·5 grms. of mercury poured on red-hot coals, and died in ten days
with all the symptoms of mercurial poisoning.
[916] Maschka’s _Handbuch_, Bd. ii. 295.
The metal taken in bulk into the stomach has been considered
non-poisonous, and, probably, when perfectly pure, it is so; we have,
however, the case of a girl who swallowed 4½ ozs. by weight of the
liquid metal, for the purpose of procuring abortion--this it did not
effect; but, in a few days, she suffered from a trembling and shaking of
the body and loss of muscular power. These symptoms continued for two
months, but there was no salivation and no blue marks on the gums. This
case is a rare one, and a pound or more has been taken without injury.
§ 838. =Absorption of Mercury by the Skin.=--Mercury in a finely divided
form, rubbed into the skin, is absorbed, and all the effects of
mercurialism result. This method of administering mercury for medicinal
purposes has long been in use, but, when the inunction is excessive,
death may occur. Thus, Leiblinger records a case in which three persons
were found dead in bed; the day before they had rubbed into the body,
for the purpose of curing the itch, a salve containing 270 grms. of
mercury finely divided.
It is difficult to say in what proportion workers in mercury, such as
water-gilders, &c., suffer. According to Hirt, not only do 1·5 to 2·1
per cent. of the workmen employed in smelting mercury ores suffer
acutely, but as high a proportion as 8·7 per cent. are slightly
affected.
§ 839. =Symptoms of Poisoning by Mercury Vapour.=--The symptoms of
poisoning by mercury vapour, or by the finely divided metal, are the
same as those which arise from the corrosive salts, with the exception
of the local action. In mild cases there is pallor, languor, and sore
mouth (from slightly inflamed gums), fœtid breath, and disorder of the
digestive organs. If the action is more intense, there is an
inflammation of the gums and, indeed, of the whole mouth, and
salivation, which is sometimes so profuse that as much as two gallons of
saliva have been secreted daily. The saliva is alkaline, has a bad
odour, and its specific gravity in the early stages is increased, but
ultimately becomes normal; the gums are raised into slight swellings,
which gradually enlarge and coalesce. The teeth that are already
carious, decay more rapidly; they become loose, and some may be shed;
the inflammatory action may extend to the jaw, and necrosis of portions
of the bone is no unusual occurrence. On recovery, the cheeks sometimes
form adhesions with the gums, and cicatrices always mark the loss of
substance which such an affection entails. With the stomatitis there are
disturbances of the gastro-intestinal tract--nausea and vomiting, pain
in the stomach, and diarrhœa alternating with constipation.
Conjunctivitis is very common, both in man and animals, from exposure to
mercury vapours. The further action of the metal is shown in its
profound effects on the nervous system. The patient is changed in his
disposition, he is excitable, nervous, or torpid; there are
sleeplessness and bad dreams, at the same time headache, noises in the
ears, giddiness, faintings, &c.
§ 840. =Mercurial Tremor.=--Mercurial tremor[917] may follow, or
accompany the above state, or it may be the chief and most prominent
effect. It specially affects the arms, partly withdrawing the muscles
from the control of the will, so that a person affected with mercurial
tremor is incapacitated for following any occupation, especially those
requiring a delicate and steady touch. In cases seriously affected, the
tremor spreads gradually to the feet and legs, and finally the whole
body may be invaded. The patient is no longer master of his muscles--the
muscular system is in anarchy, each muscle aimlessly contracting and
relaxing independently of the rest--the movement of the legs becomes
uncertain, the speech stuttering, the facial expressions are even
distorted into grimaces, and the sufferer sinks into a piteous state of
helplessness. The convulsive movements generally cease during sleep. The
tremors are accompanied by interference with the functions of other
organs: the respiration is weakened and difficult; dyspnœa, or an
asthmatic condition, results; the pulse is small and slow; paresis,
deepening into paralysis of the extremities, or of a group of muscles,
follows; and, lastly, if the condition is not alleviated, the patient
becomes much emaciated and sinks from exhaustion. Pregnant women are
liable to abortion, and the living infants of women suffering from
tremor have also exhibited tremor of the limbs.
[917] A case of mercurial tremor (in _Bericht. des K. K. Allgem.
Krankenhauses zu Wien im Jahre 1872_, Wien, 1873) is interesting, as
showing the influence of pregnancy. A woman, twenty years of age,
employed in making barometers, had, in 1869, mercurial tremor and
salivation. During a three months’ pregnancy the tremor ceased, but
again appeared after she had aborted. She again became pregnant, and the
tremor ceased until after her confinement in November 1871. The tremor
was so violent that the patient could not walk; she also had stomatitis;
but ultimately, by treatment with galvanism and other remedies, she
recovered.
In the case of the “mass poisoning” on board the “Triumph,” it has been
mentioned that several of the sailors became consumptive, and the same
effect has been noticed among all workers in the metal; it is now,
indeed, an accepted fact that the cachexia induced by mercurialismus
produces a weak habit of body specially liable to the tuberculous
infection.
The course of the poisoning is generally more rapid when it has
resulted from the taking of mercury internally as a medicine than when
inhaled by workers in the metal, _e.g._, a patient suffering from
mercurial tremor shown to the Medical Society by Mr. Spencer Watson in
1872, had resisted for seven years the influence of the fumes of
mercury; and then succumbed, exhibiting the usual symptoms. Idiosyncrasy
plays a considerable _rôle_; some persons (and especially those whose
kidneys are diseased) bear small doses of mercury ill, and are readily
salivated or affected; this is evidently due to imperfect elimination.
§ 841. =Mercuric Methide=, Hg(CH₃)₂.--This compound is obtained by the
action of methyl iodide on sodium amalgam in the presence of acetic
ether. It is a dense, stable liquid, of highly poisonous properties. In
1865, mercuric methide, in course of preparation in a London laboratory,
caused two cases of very serious slow poisoning.[918] One was that of a
German, aged 30, who was engaged in preparing this compound for three
months, and during this time his sight and hearing became impaired; he
was very weak, his gums were sore, and he was ultimately admitted into
St. Bartholomew’s Hospital, February 3rd, 1865. His urine was found to
be albuminous, and his mental faculties very torpid. On the 9th he
became noisy, and had to be put under mechanical restraint. On the 10th
he was semi-comatose, but there was no paralysis; his breath was very
offensive, his pupils dilated; at intervals he raised himself and
uttered incoherent howls. There was neither sensation nor motion in the
left leg, which was extended rigidly; the knee and the foot were turned
slightly inward. On the 14th he died insensible.
[918] _St. Barth. Hosp. Reports_, vol. i., 1866, p. 141.
The only appearance of note seen at the autopsy was a congestion of the
grey matter in the brain; the kidneys and liver were also congested, and
there were ecchymoses in the kidneys.
The second case--a young man, aged 23, working in the same
laboratory--was admitted into the hospital, March 28th, 1865. In the
previous January he had been exposed to the vapour of mercuric methide
for about a fortnight; during the illness of the other assistant he felt
ill and weak, and complained of soreness of the gums and looseness of
the teeth. He had also dimness of vision, pain and redness of the eyes,
giddiness, nausea and vomiting, the ejected matters being greenish and
watery. At the beginning of March his sight and taste became
imperfect--all things tasted alike; his tongue was numb and his gums
sore, he was also salivated slightly. A week before admission he lost
his hearing, and first his hands and then his feet became numb; on
admission his breath was very offensive, his pupils dilated; the sight
impaired; he was very deaf, and his powers of speech, taste, and smell
were deficient. There was anæsthesia of the body, and the movement of
the limbs was sluggish and difficult. He continued in the hospital for
nearly a month, with but little change. On April 24th, it was noticed
that he was getting thinner and slightly jaundiced; he moved his arms
aimlessly in an idiotic manner, and passed his urine involuntarily. On
April 27th he was more restless, and even violent, shrieking out and
making a loud, incoherent noise, or laughing foolishly; he passed his
motions and urine beneath him. On July 7th he was in a similar
state--perfectly idiotic. He died on April 7th, 1866, about a year and
three months from his first exposure to the vapour; the immediate cause
of death was pneumonia. The _post-mortem_ appearances of the brain and
membranes differed little from the normal state; the grey matter was
pink, but otherwise healthy; there was a considerable amount of
cerebro-spinal fluid; the arachnoid along the longitudinal fissure was
thickened; the total weight of the brain with medulla was 41 ozs. The
stomach was of enormous size; the pyramids of the kidneys were
congested, as was also the small intestine; the lungs showed the usual
signs of pneumonia.[919]
[919] _St. Barth. Hosp. Reports_, vol. ii. p. 211.
§ 842. =Effects of the Corrosive Salts of Mercury.=--The type of the
corrosive salts is mercuric chloride, or corrosive sublimate--a compound
which acts violently when administered, either externally or internally,
in large doses.[920] If the poison has been swallowed, the symptoms come
on almost immediately, and always within the first half hour; the whole
duration also is rapid. In 36 cases collected by F. A. Falck, 11 died on
the first or second day, and 11 on the fifth day; so that 61 per cent.
died in five days--the remainder lived from six to twenty-six days. The
shortest fatal case on record is one communicated to Dr. Taylor by Mr.
Welch; in this instance the man died from an unknown quantity within
half an hour.
[920] The effects on animals are similar to those on man. Richard Mead
gave a dog with bread 3·8 grms. (60 grains) of corrosive
sublimate:--“Within a quarter of an hour he fell into terrible
convulsions, casting up frequently a viscid frothy mucus, every time
more and more bloody, till, tired and spent with this hard service, he
lay down quietly, as it were, to sleep, but died the next morning.”
In the very act of swallowing, a strong metallic taste and a painful
sensation of constriction in the throat are experienced. There is a
burning heat in the throat extending downwards to the stomach. All the
mucous membranes with which the solution comes in contact are attacked,
shrivelled, and whitened; so that, on looking into the mouth, the
appearance has been described as similar to that produced by the recent
application of silver nitrate. The local changes may be so intense as to
cause œdema of the glottis, and death through asphyxia. In a few minutes
violent pain is felt in the stomach; so much so, that the sufferer is
drawn together, and is in a fainting condition; but there are rare cases
in which pain has been absent. There are nausea and vomiting, the
ejected matters being often streaked with blood; after the vomiting
there is purging; here also the motions are frequently bloody.[921] The
temperature of the body sinks, the respiration is difficult, and the
pulse small, frequent, and irregular. The urine is generally scanty, and
sometimes completely suppressed.[922] Sometimes there is profuse
hæmorrhage from the bowel, stomach, or other mucous membrane, and such
cases are accompanied by a considerable diminution of temperature. In a
case recorded by Lœwy,[923] after a loss of blood by vomiting and
diarrhœa, the temperature sank to 33·4°. The patient dies in a state of
collapse, or insensibility, and death is often preceded by convulsions.
[921] The mixture of blood with the evacuations is more constantly
observed in poisoning by corrosive sublimate than in poisoning by
arsenic, copper, or lead.
[922] In a case recorded by Dr. Wegeler (Casper’s _Wochenschrift_,
January 10, 1846, p. 30), a youth, aged 17, swallowed 11·6 grms. (3
drachms) of the poison. No pain was experienced on pressure of the
abdomen; he died on the sixth day, and during the last three days of
life no urine was secreted.
[923] _Vierteljahrsschr. für ger. Med._, 1864, vol. i. p. 187.
§ 843. Two remarkable cases of death from the external use of corrosive
sublimate are recorded by Anderseck. An ointment, containing corrosive
sublimate, was rubbed into the skin of two girls, servants, in order to
cure the itch. The one, during the inunction, complained of a burning of
the skin; the other also, a little while after, suffered in the same
way. During the night the skin of each swelled, reddened, and became
acutely painful. There were thirst and vomiting, but no diarrhœa, On the
following day there was an eruption of blebs or little blisters. On the
third day they had diarrhœa, tenesmus, fever, and diminution of the
renal secretion; on the fourth day, fœtid breath, stomatitis,
hyperæsthesia of the body, and a feeling of “pins and needles” in the
hands and feet were noted. The first girl died in the middle of the
fifth day, fully conscious; the other died on the sixth. So also
Taylor[924] gives the case of a girl, aged 9, who died from the effects
of an alcoholic solution of corrosive sublimate (strength, 80 grains to
the oz.) applied to the scalp as a remedy for ringworm. The same
author[925] further quotes the case of two brothers who died--the one on
the fifth, the other on the eleventh day--from the effects of absorbing
corrosive sublimate through the unbroken skin.
[924] _Op. cit._
[925] _Poisons_, 1848, p. 394.
§ 844. =The Nitrates of Mercury= are poisons, but little (if at all)
inferior in corrosive action to mercuric chloride. Death has resulted
from both the external and internal use. Application of the nitrate as
an escharotic to the _os uteri_, in one case,[926] produced all the
symptoms of mercurial poisoning, but the woman recovered; in another
case,[927] its use as a liniment caused death.
[926] _Med. Gazette_, vol. 45, p. 1025.
[927] _Edin. Monthly Journal_, 1864, p. 167.
§ 845. When taken internally, the symptoms are scarcely different from
those produced by corrosive sublimate. It seems an unlikely vehicle for
criminal poisoning, yet, in the case of _Reg._ v. _E. Smith_ (Leicester
Summer Assizes, 1857), a girl was proved to have put a solution of
nitrate of mercury in some chamomile tea, which had been prescribed for
the prosecutrix. The nauseous taste prevented a fatal dose being taken;
but the symptoms were serious.
§ 846. =Mercuric Cyanide= acts in a manner very similar to that of
corrosive sublimate, 1·3 grm. (about 20 grains) in one case,[928] and in
another[929] half the quantity, having destroyed life.
[928] Orfila, i. p. 735.
[929] Christison, p. 427.
§ 847. =White Precipitate= (ammoniated mercury), as a poison, is weak.
Out of fourteen cases collected by Taylor, two only proved fatal; one of
these formed the subject of a trial for murder, _Reg._ v. _Moore_ (Lewes
Lent Assizes, 1860). The effects produced are vomiting, purging, &c., as
in corrosive sublimate.[930] Other preparations of mercury, such as the
red iodide, the persulphide, and even calomel,[931] have all a more or
less intense poisonous action, and have caused serious symptoms and
death.
[930] See Dr. Th. Stevenson, “Poisoning by White Precipitate,” _Guy’s
Hospital Reports_, vol. xix. p. 415.
[931] Seidel quotes a case from Hasselt, in which a father, for the
purpose of obtaining insurance money, killed his child by calomel.
§ 848. =Treatment of Acute and Chronic Poisoning.=--In acute poisoning,
vomiting usually throws off some of the poison, if it has been
swallowed; and the best treatment seems to be, to give copious
albuminous drinks, such, for example, as the whites of eggs in water,
milk, and the like. The vomiting may be encouraged by subcutaneous
injections of apomorphine. The after-treatment should be directed to
eliminating the poison, which is most safely effected by very copious
drinks of distilled water (see “Appendix”).
The treatment of slow poisoning is mainly symptomatic; medicinal doses
of zinc phosphide seem to have done good in mercurial tremors. Potassic
iodide is also supposed to assist the elimination of mercury.
§ 849. =Post-mortem Appearances.=--The pathological effects seen after
chronic poisoning are too various to be distinctive. In the museum of
the Royal College of Surgeons there is (No. 2559) the portion of a colon
derived from a lady aged 74.[932] This lady had been accustomed for
forty-three years to take a grain of calomel every night; for many years
she did not suffer in health, but ultimately she became emaciated and
cachectic, with anasarca and albuminuria. The kidneys were found to be
granular, and the mucous membrane of a great part of the intestine of a
remarkable black colour, mottled with patches of a lighter hue,
presenting somewhat the appearance of a toad’s back. From the portion of
colon preserved mercury was readily obtained by means of Reinsch’s
test. The black deposit is in the submucosa, and it is, without doubt,
mercurial, and probably mercury sulphide. In acute poisoning (especially
by the corrosive salts) the changes are great and striking. After rapid
death from corrosive sublimate, the escharotic whitening of the mouth,
throat, and gullet, already described, will be seen. The mucous membrane
right throughout, from mouth to anus, is more or less affected and
destroyed, according to the dose and concentration of the poison. The
usual appearances in the stomach are those of intense congestion, with
ecchymoses, and portions of it may be destroyed. Sometimes the coats are
very much blackened; this is probably due to a coating of sulphide of
mercury.
[932] _Path. Soc. Trans._, xviii. 111.
In St. George’s Hospital Museum (Ser. ix. 43, y. 337) there is a
stomach, rather large, with thickened mucous coats, and having on
the mucous surface a series of parallel black, or black-brown lines
of deposit; it was derived from a patient who died from taking
corrosive sublimate. With the severe changes mentioned, perforation
is rare.[933] In the intestines there are found hyperæmia,
extravasations, loosening of the mucous membrane, and other changes.
The action is particularly intense about the cæcum and sigmoid
flexure; in one case,[934] indeed, there was little inflammatory
redness of the stomach or of the greater portion of the intestine,
but the whole surface of the cæcum was of a deep black-red colour,
and there were patches of sloughing in the coats. The kidneys are
often swollen, congested, or inflamed; changes in the respiratory
organs are not constantly seen, but in a majority of the cases there
have been redness and swelling of the larynx, trachea, and bronchi,
and sometimes hepatisation of smaller or larger portions of the
lung.
[933] There is only one case of perforation on record.
[934] _Lancet_, 1845, p. 700.
In St. George’s Hospital Museum, there are (from a patient dying in
the hospital) preparations which well illustrate what pathological
changes may be expected in any case surviving for a few days. The
patient was Francis L----, aged 45, admitted to the hospital,
February 27, 1842. He took a quantity of corrosive sublimate spread
on bread and butter, was immediately sick, and was unable to take as
much as he had intended. The stomach-pump and other remedies were
used. On the following day his mouth was sore, and on March 1st his
vision was dim; his mouth was drawn over to the right side, and he
lost power over the left eyelid, but he had no pain; he passed some
blood from the bowel. On the 2nd he passed much blood, and was
salivated; still no pain. On March 4, on the evening of the sixth
day, he expired; he was drowsy during the last day, and passed
watery evacuations.
Prep. 14a, Ser. ix., shows the pharynx, œsophagus, and tongue; there
is ulceration of the tonsils, and fibrinous exudation on the gullet.
The stomach (43b, 199) shows a large dark slough, three inches from
the cardiac extremity; the margin surrounding the slough is
thickened, ulcerated, and irregular in shape, the submucous tissue,
to some extent, being also thickened; there is fibrine in the ileum,
pharynx, and part of the larynx. The action extended to the whole
intestine, the rectum in prep. 145a, 36, is seen to be thickened,
and has numerous patches of effused fibrine.
It is a curious fact that the external application of corrosive
sublimate causes inflammatory changes in the alimentary canal of nearly
the same intensity as if the poison had been swallowed. Thus, in the
case of the two girls mentioned _ante_ (p. 647), there was found an
intense inflammation of the stomach and intestines, the mucous tissues
being scarlet-red, swollen, and with numerous extravasations.
§ 850. The effects of the nitrate of mercury are similar to the
preceding; in the few cases which have been recorded, there has been
intense redness, and inflammation of the stomach and intestines, with
patches of ecchymosis. White precipitate, cyanide of mercury, mercuric
iodide, and mercurous sulphide (turpeth-mineral) have all caused
inflammation, more or less intense, of the intestinal tract.
§ 851. =Elimination of Mercury.=--The question of the channels by which
mercury is eliminated is of the first importance. It would appear
certain that it can exist in the body for some time in an inactive
state, and then, from some change, be carried into the circulation and
show its effects.[935] Voit considers that mercury combines with the
albuminous bodies, separating upon their oxidation, and then becoming
free and active.[936]
[935] Tuson gave a mare, first, 4 grains, and afterwards 5 grains of
corrosive sublimate twice a day; at the end of fourteen days, in a pint
of urine no mercury was detected, but at the end of three weeks it was
found.
[936] _Voit, Physiol. chem. Unters._, Augsburg, 1857.
Ullmann[937] found most mercury in the following order:--Kidneys, liver,
spleen, a small quantity in the stomach, no mercury in the small
intestine, but some in the large intestine; small weighable quantities
in the heart and skeletal muscles, also in the lungs; but no mercury,
when the dose was small, in brain, the salivary glands, abdominal
glands, thyroid glands, the bile, or the bones.
[937] _Chem. Centr._, 1892, ii. 941.
The main channel by which absorbed mercury passes out of the body is the
kidneys, whilst mercurial compounds of small solubility are in great
part excreted by the bowel. A. Bynssen,[938] after experimenting with
mercuric chloride (giving ·015 to ·15 grm., with a little morphine
hydrochlorate), came to the conclusion that it could be detected in the
urine about two hours, and in the saliva about four hours, after its
administration; he considered that the elimination was finished in
twenty-four hours.
[938] _Journal de l’Anat. et de Physiol._, 1872, No. 5, p. 500. On the
separation of mercury by the urine, see also Salkowsky in Virchow’s
_Archiv_, 1866.
From the body of a hound that, in the course of thirty-one days, took
2·789 grms. of calomel (2·368 Hg) in eighty-seven doses, about 94 per
cent. of the substance was recovered on analysis:--
Mercurous
Sulphide.
Grms.
In the fæces, 2·1175
„ urine, 0·0550
„ brain, heart, lungs, spleen, pancreas,
kidneys, scrotum, and penis, 0·0090
„ liver, 0·0140
„ muscles, 0·0114
------
2·2069
This equals 1·9 of metallic mercury.[939] Thus, of the whole 2·2 grms.
of mercuric sulphide separated, over 95 per cent. was obtained from the
fæces.
[939] Riederer, in Buchner’s _Neues Repert. f. Pharm._, Bd. xvii. 3,
257, 1868.
This case is of considerable interest, for there are recorded in
toxicological treatises a few cases of undoubted mercurial poisoning in
which no poison had been detected, although there was ample evidence
that it had been administered by the mouth. In such cases, it is
probable that the whole length of the intestinal canal had not been
examined, and the analysis failed from this cause. When (as not
unfrequently happens) the mercurial poison has entered by the skin, it
is evident that the most likely localities are the urine, the liver, and
the kidneys.[940]
[940] A woman died from the effects of a corrosive sublimate lotion
applied by a quack to a wound in her leg. The writer found no poison in
the stomach, but separated a milligramme of metallic mercury from the
liver; the urine and intestines were not sent.
In a case related by Vidal,[941] the _Liquor Bellostii_ (or solution of
mercuric nitrate) was ordered by mistake instead of a liniment. Although
externally applied, it caused salivation, profuse diarrhœa, and death in
nine days. The whole of the intestinal tract was found inflamed with
extravasations, and mercury detected in the liver.
[941] _Gaz. des Hôp._, Juillet 1864.
In any case of external application, if death ensues directly from the
poison, evidence of its presence will probably be found; but too much
stress must not be laid upon the detection of mercury, for, as Dr.
Taylor says, “Nothing is more common than to discover traces of mercury
in the stomach, bowels, liver, kidneys, or other organs of a dead
body.”[942]
[942] Taylor, _Medical Jurisprudence_, i. p. 288.
§ 852. =Tests for Mercury.=--Mercury, in combination and in the solid
form, is most readily detected by mixing the substance intimately with
dry anhydrous sodic carbonate, transferring the mixture to a glass tube,
sealed at one end, and applying heat. If mercury be present, a ring of
minute globules condenses in the cool part of the tube. If the quantity
of mercury is likely to be very minute, it is best to modify the process
by using a subliming cell (p. 258), and thus obtain the sublimate on a
circle of thin glass in a convenient form for microscopical examination.
If there is any doubt whether the globules are those of mercury or not,
this may be resolved by putting a fragment of iodine on the lower disc
of the subliming cell, and then completing it by the disc which contains
the sublimate (of course, the supposed mercurial surface must be
undermost); on placing the cell in a warm, light place, after a time the
scarlet iodide is formed, and the identification is complete. Similarly,
a glass tube containing an ill-defined metallic ring of mercury can be
sealed or corked up with a crystal of iodine, and, after a few hours,
the yellow iodide, changing to scarlet, will become apparent. There are
few (if any) tests of greater delicacy than this.
Mercury in solution can be withdrawn by acidulating the liquid, and then
inserting either simply a piece of gold foil, gold wire, or bright
copper foil; or else, by a galvanic arrangement, such as iron wire wound
round a gold coin, or gold foil attached to a rod of zinc; or, lastly,
by the aid of gold or copper electrodes in connection with a battery. By
any of these methods, mercury is obtained in the metallic state, and the
metal with its film can be placed in a subliming cell, and globules
deposited and identified, as before described.
The =Precipitating Reagents= for mercury are numerous: a solution of
stannous chloride, heated with a solution of mercury, or any
combination, whether soluble or insoluble, reduces it to the metallic
state.
=Mercurous Salts= in solution yield, with potash, soda, or lime, a black
precipitate of mercurous oxide. =Mercuric Salts=, a bright yellow
precipitate of mercuric oxide.
=Mercurous Salts= yield black precipitates, with sulphides of ammonium
and hydrogen. =Mercuric Salts= give a similar reaction, but, with
sulphuretted hydrogen, first a whitish precipitate, passing slowly
through red to black.
=Mercurous Salts=, with solutions of the chlorides, give a white
precipitate of calomel; the =Mercuric Salts= yield no precipitate under
similar circumstances. =Mercurous Salts=, treated with iodide of
potassium, give a green mercurous iodide; =Mercuric=, a scarlet.
§ 853. =The Detection of Mercury in Organic Substances and
Fluids.=--Ludwig’s process, previously described, is found in practice
the best. Fluids, such as urine, must be evaporated to dryness, and then
treated with hydrochloric acid. Such organs as the liver are cut up and
boiled in 20 per cent. HCl. Distinct evidence of mercury in the liver
has been obtained on a piece of copper gauze, in a case where a child
had been given 2 grains of calomel before death. “Four ounces of the
liver were treated with hydrochloric acid and water, and a small piece
of pure copper placed in the acid liquid while warm, and kept there for
about forty-eight hours. It acquired a slight silvery lustre, and
globules of mercury were obtained from it by sublimation.”
To detect the cyanide of mercury may require special treatment, and
Vitali[943] recommends the following process:--The fluid is acidified
with tartaric acid and neutralised by freshly precipitated CaCO₃; a
slight excess of hydric sulphide is added, and the flask allowed to rest
for twenty-four hours in the cold. Then a further quantity of SH₂ is
added, and a current of hydrogen passed through the liquid; the effluent
gas is first made to bubble through a solution of bismuth nitrate in
dilute nitric acid (for the purpose of absorbing SH₂), and then through
aqueous potash (to absorb HCl); in the first flask the analyst will
separate and identify mercury sulphide, while in the last flask there
will be potassic cyanide, which will respond to the usual tests.
[943] _L’Orosi_, xii. 181-196.
In those cases where no special search is made for mercury, but an acid
(hydrochloric) solution is treated with sulphuretted hydrogen, mercury
is indicated by the presence of a black precipitate, which does not
dissolve in warm nitric acid.
The further treatment of the black sulphide may be undertaken in two
ways:--
(1) It is collected on a porcelain dish, with the addition of a little
nitric acid, and evaporated to dryness in order to destroy organic
matter. Hydrochloric and a few drops of nitric acid are next added; the
action is aided by a gentle heat, the solution finally evaporated to
dryness on the water-bath, and the residue taken up by warm distilled
water. The solution is that of a persalt of mercury, and the mercury can
be separated by electrolysis, or indicated by the tests already
detailed.
(2) The other method, and the most satisfactory, is to mix the sulphide
while moist with dry carbonate of soda, make it into a pellet which will
easily enter a reducing or subliming tube, dry it carefully, and obtain
a sublimate of metallic mercury.
A neat method of recognising mercury when deposited as a film on copper
has been proposed by E. Brugnatelli:[944] the copper, after being
washed, is transferred to a glass vessel, and a porcelain lid, on which
a drop of gold chloride solution has been placed, adjusted over the
dish. The whole is heated by a water-bath. The mercury vapour reduces
the gold chloride, and gold is deposited as a bluish-violet stain; 1/10
mgrm. mercury may by this test be identified.
[944] _Gazzetta_, xix. 418-422.
Of special methods for the separation and detection of mercury,
Ludwig’s[945] is, without a doubt, the best when organic matters have to
be dealt with; the finely divided solid substances are boiled for some
hours with hydrochloric acid, strength 20 per cent.; then the liquid is
cooled to 60°, and potassic chlorate added in half gramme quantities
until the dark liquid becomes clear; the liquid is cooled and filtered,
and the substances on the filter washed with water. To the filtrate 5
grms. of zinc dust are added, and the liquid is violently shaken from
time to time; a second portion is afterwards added, and also vigorously
shaken. After some hours the clear liquid is separated from the zinc and
the zinc washed, first with water, then with a little soda solution, and
finally, again with water. The zinc is now collected on a glass-wool
filter, treated with absolute alcohol to remove water, and dried by
suction in a stream of air. The zinc is put into a combustion-tube, the
tube being drawn out into a thin capillary extremity, and a combustion
made, the mercury collecting at the capillary part. It is a necessary
refinement, should the zinc be contaminated with a trace of organic
matter, to pack the combustion-tube as follows:--First, the zinc dust on
which any mercury present has been deposited, then a plug of asbestos;
next, some cupric oxide; and lastly, some pure zinc dust.
Bondzynski[946] prefers to use copper rather than zinc; for he says that
zinc so frequently contains cadmium, which latter metal also gives a
mirror, so that, unless the mercury is afterwards identified by turning
it into an iodide, error may be caused.
[945] _Zeit. f. physiolog. Chemie_, 1882, i. 495; _Chem. Centrblt._,
1892, ii. 941.
[946] _Zeit. f. anal. Chem._, xxxii. 302-305.
[Illustration]
§ 854. =Estimation of Mercury.=--All pharmaceutical substances
containing mercury, as well as the sulphide prepared in the wet way, and
minerals, are best dealt with by obtaining and weighing the metal in the
solid state. The assay is very simple and easy when carried out on the
method that was first, perhaps, proposed by Domeyko. A glass tube (which
should not be too thin), closed at one end, is bent, as shown in the
figure, the diameter should be about three lines, the length from 7 to 8
inches, the shorter arm not exceeding 2 inches. The powdered substance
is mixed with two or three times its weight of litharge, and introduced
into the tube at _a_. The portion of the tube containing the mercury is
at first heated gently, but finally brought to a temperature sufficient
to fuse the substance and soften the glass. The mercury collects in an
annular film at _b_ in the cooler limb, and may now, with a little
management of the lamp, be concentrated in a well-defined ring; the
portion of the tube containing this ring is cut off, weighed, then
cleansed from mercury, and reweighed. Many of the pharmaceutical
preparations do not require litharge, which is specially adapted for
ores, and heating with sodic carbonate (in great excess) will suffice.
Mercury mixed with organic matter must be first separated as described,
by copper or gold, the silvered foil rolled up, dried, introduced into
the bent tube, and simply heated without admixture with any substance;
the weight may be obtained either by weighing the foil before and after
the operation, or as above.
§ 855. =Volumetric Processes for the Estimation of Mercury.=--When a
great number of mercurial preparations are to be examined, a volumetric
process is extremely convenient. There are several of these processes,
some adapted more particularly for mercuric, and others for mercurous
compounds. For mercuric, the method of Personne[947] is the best. The
conversion of the various forms of mercury into corrosive sublimate may
be effected by evaporation with aqua regia, care being taken that the
bath shall not be at a boiling temperature, or there will be a slight
loss.
[947] _Comptes Rendus_, lvi. 68; Sutton’s _Vol. Anal._, 177.
Personne prefers to heat with caustic soda or potash, and then pass
chlorine gas into the mixture; the excess of chlorine is expelled by
boiling, mercuric chloride in presence of an alkaline chloride not being
volatilised at 100°. The standard solutions required for this process
are:--
(1) 33·2 grms. of potassic iodide in 1 litre of water, 1 c.c. = 0·01
grm. Hg, or 0·01355 grm. HgCl₂.
(2) A solution of mercuric chloride containing 13·55 grms. to the litre,
1 c.c. = 0·1 grm. Hg.
The process is founded on the fact that, if a solution of mercuric
chloride be added to one of potassic iodide, in the proportion of one of
the former to four of the latter, mercuric iodide is formed, and
immediately dissolved, until the balance is overstepped, when the red
colour is developed; the final reaction is very sharp, and with
solutions properly made is very accurate. The mercuric solution must
always be added to the alkaline iodide; a reversal of the process does
not answer. It therefore follows that the solution to be tested must be
made up to a definite bulk, and added to a known quantity of the
potassic iodide until the red colour appears.
=Mercurous Salts= may be titrated with great accuracy by a decinormal
solution of sodic chloride. This is added to the cold solution in very
slight excess, the calomel filtered off, the filtrate neutralised by
pure carbonate of soda, and the amount of sodic chloride still unused
found by titration with nitrate of silver, the end reaction being
indicated by chromate of potash. Several other volumetric processes are
fully described in works treating upon this branch of analysis.
III.--PRECIPITATED BY HYDRIC SULPHIDE FROM A NEUTRAL SOLUTION.
Zinc--Nickel--Cobalt.
1. ZINC.
§ 856. =Zinc=--At. wt., 65; specific gravity, 6·8 to 7·1; fusing-point,
412° (773° F.)--is a hard, bluish-white, brittle metal, with a
crystalline fracture. Between 100° and 150° it becomes ductile, and may
be easily wrought, but at a little higher temperature it again becomes
brittle, and at a bright red heat it fuses, and then volatilises, the
fumes taking fire when exposed to the air. In analysis, zinc occurs
either as a metallic deposit on a platinum foil or dish, or as a brittle
bead, obtained by reducing a zinc compound with soda on charcoal.
The salts of zinc to be briefly described here are the carbonate, the
oxide, and the sulphide,--all of which are likely to occur in the
separation and estimation of zinc, and the sulphate and chloride,--salts
more especially found in commerce, and causing accidents from time to
time.
§ 857. =Carbonate of Zinc=, in the native form of calamine, contains, as
is well known, 64·8 per cent. of oxide of zinc; but the carbonate
obtained in the course of an analysis by precipitating the neutral hot
solution of a soluble salt of zinc by carbonate of potash or soda, is
carbonate of zinc _plus_ a variable quantity of hydrated oxide of zinc.
Unless the precipitation takes place at a boiling temperature, the
carbonic anhydride retains a portion of the oxide of zinc in solution.
By ignition of the carbonate, oxide of zinc results.
§ 858. =Oxide of Zinc= (ZnO = 81; specific gravity, 5·612; Zn, 80·24, O,
19·76) is a white powder when cool, yellow when hot. If mixed with
sufficient powdered sulphur, and ignited in a stream of hydrogen, the
sulphide is produced; if ignited in the pure state in a rapid stream of
hydrogen gas, metallic zinc is obtained; but, if it is only a feeble
current, the oxide of zinc becomes crystalline, a portion only being
reduced.
§ 859. =Sulphide of Zinc= (ZnS = 97; specific gravity, 4·1; Zn, 67·01,
S, 32·99).--The sulphide obtained by treating a neutral solution of a
soluble salt of zinc by hydric sulphide is hydrated sulphide, insoluble
in water, caustic alkalies, and alkaline sulphides, but dissolving
completely in nitric or in hydrochloric acid. When dry, it is a white
powder, and if ignited contains some oxide of zinc. The anhydrous
sulphide is produced by mixing the precipitated sulphide with sulphur,
and igniting in a crucible in a stream of hydrogen gas.
=Pharmaceutical Preparations.=--The officinal compounds of zinc used in
medicine are the _acetate_, _carbonate_, _chloride_, _oxide_,
_sulphate_, _sulphocarbolate_, and _valerianate_.
=Sulphate of Zinc= (ZnSO₄7H₂O 161 + 126; specific gravity, crystals,
1·931).--This salt is officinal in all the pharmacopœias, is used in
calico-printing, and is commonly known as _white vitriol_. By varying
the temperature at which the crystals are allowed to be formed, it may
be obtained with 6, 5, 2, or 1 atoms of water. The commercial sulphate
is in crystals exactly similar to those of Epsom salts; it is slightly
efflorescent, and gives the reactions of zinc and sulphuric acid.
§ 860. =Chloride of Zinc= is obtained by dissolving zinc in hydrochloric
acid, or by direct union of zinc and chlorine. Chloride of zinc is the
only constituent in the well-known “Burnett’s disinfectant fluid.” A
solution of chloride of zinc may be heated until it becomes water-free;
when this takes place it still remains fluid, and makes a convenient
bath, for warmth may be applied to it above 370° without its emitting
fumes to inconvenience; at a red heat it distils. A concentrated
solution of zinco-ammonic chloride (2H₄NClZnCl₂) is used for the purpose
of removing the film of oxide from various metals preparatory to
soldering.