Chloral (or chloroform), when boiled wit_Poisons, Their Effects and Detection A Manual for the Use of Analytical Chemists and Experts

strongly alkaline with NaHO, gives a red colour, which disappears on

acidifying and is restored by alkalies. If, on the other hand, there is

an excess of resorcinol and only a very small quantity of NaHO used, the

product shows a yellowish-green fluorescence; 1/10 of a milligramme of

chloral hydrate gives this reaction distinctly when boiled with 50

mgrms. of resorcinol and 5 drops of a normal solution of sodium

hydrate.[191]

[191] C. Schwarz, _Pharm. Zeit._, xxxiii. 419.

Dr. Frank Ogston[192] has recommended sulphide of ammonium to be added

to any liquid as a test for chloral. The contents of the stomach are

filtered or submitted to dialysis, and the test applied direct. If

chloral is present, there is first an orange-yellow colour; on standing,

the fluid becomes more and more brown, then troubled, an amorphous

precipitate falls to the bottom, and a peculiar odour is developed. With

10 mgrms. of chloral in 1 c.c. of water, there is an evident

precipitate, and the odour can readily be perceived; with 1 mgrm.

dissolved in 1 c.c. of water, there is an orange-yellow colour, and also

the odour, but no precipitate; with ·1 mgrm. in 1 c.c. of water, there

is a weak, pale, straw-yellow colour, which can scarcely be called

characteristic. The only substance giving in neutral solutions the same

reactions is antimony; but, on the addition of a few drops of acid, the

antimony falls as an orange-yellow precipitate, while, if chloral alone

is present, there is a light white precipitate of sulphur.

[192] _Vierteljahrsschrift f. gerichtl. Medicin_, 1879, Bd. xxx. Hft. 1,

S. 268.

VIII.--Bisulphide of Carbon.

§ 208. Bisulphide of carbon--_carbon disulphide_, _carbon sulphide_

(CS₂)--is a colourless, volatile fluid, strongly refracting light.

Commercial samples have a most repulsive and penetrating odour, but

chemically pure carbon sulphide has a smell which is not disagreeable.

The boiling-point is 47°; the specific gravity at 0° is 1·293. It is

very inflammable, burning with a blue flame, and evolving sulphur

dioxide; is little soluble in water, but mixes easily with alcohol or

ether. Bisulphide of carbon, on account of its solvent powers for

sulphur, phosphorus, oils, resins, caoutchouc, gutta-percha, &c., is in

great request in certain industries. It is also utilised for

disinfecting purposes, the liquid being burnt in a lamp.

§ 209. =Poisoning by Carbon Bisulphide.=--In spite of the cheapness and

numerous applications of this liquid, poisoning is very rare. There

appears to be a case on record of attempted self-destruction by this

agent, in which a man took 2 ozs. (56·7 c.c.) of the liquid, but without

a fatal result. The symptoms in this case were pallor of the face, wide

pupils, frequent and weak pulse, lessened bodily temperature, and

spasmodic convulsions. Carbon disulphide was detected in the breath by

leading the expired air through an alcoholic solution of

triethyl-phosphin, with which it struck a red colour. It could also be

found in the urine in the same way. An intense burning in the throat,

giddiness, and headache lasted for several days.

§ 210. Experiments on animals have been frequent, and it is found to be

fatal to all forms of animal life. There is, indeed, no more convenient

agent for the destruction of various noxious insects, such as moths, the

weevils in biscuits, the common bug, &c., than bisulphide of carbon. It

has also been recommended for use in exterminating mice and rats.[193]

Different animals show various degrees of sensitiveness to the vapour;

frogs and cats being less affected by it than birds, rabbits, and

guinea-pigs. It is a blood poison; methæmoglobin is formed, and there is

disintegration of the red blood corpuscles. There is complete anæsthesia

of the whole body, and death occurs through paralysis of the respiratory

centre, but artificial respiration fails to restore life.

[193] Cloëz, _Compt. Rend._, t. 63, 85.

§ 211. =Chronic Poisoning.=--Of some importance is the chronic poisoning

by carbon disulphide, occasionally met with in manufactures

necessitating the daily use of large quantities for dissolving

caoutchouc, &c. When taken thus in the form of vapour daily for some

time, it gives rise to a complex series of symptoms which may be divided

into two principal stages--viz., a stage of excitement and one of

depression. In the first phase, there is more or less permanent

headache, with considerable indigestion, and its attendant loss of

appetite, nausea, &c. The sensitiveness of the skin is also heightened,

and there are curious sensations of creeping, &c. The mind at the same

time in some degree suffers, the temper becomes irritable, and singing

in the ears and noises in the head have been noticed. In one factory a

workman suffered from an acute mania, which subsided in two days upon

removing him from the noxious vapour (_Eulenberg_). The sleep is

disturbed by dreams, and, according to Delpech,[194] there is

considerable sexual excitement, but this statement has in no way been

confirmed. Pains in the limbs are a constant phenomenon, and the French

observers have noticed spasmodic contractions of certain groups of

muscles.

[194] _Mémoire sur les Accidents que développe chez les ouvrières en

caoutchouc du sulfure de carb. en vapeur_, Paris, 1856.

The stage of depression begins with a more or less pronounced anæsthesia

of the skin. This is not confined to the outer skin, but also affects

the mucous membranes; patients complain that they feel as if the tongue

were covered with a cloth. The anæsthesia is very general. In a case

recorded by Bernhardt,[195] a girl, twenty-two years old, who had worked

six weeks in a caoutchouc factory, suffered from mental weakness and

digestive troubles; there was anæsthesia and algesis of the whole skin.

In these advanced cases the mental debility is very pronounced, and

there is also weakness of the muscular system. Paralysis of the lower

limbs has been noted, and in one instance a man had his right hand

paralysed for two months. It seems uncertain how long a person is likely

to suffer from the effects of the vapour after he is removed from its

influence. If the first stage of poisoning only is experienced, then

recovery is generally rapid; but if mental and muscular weakness and

anæsthesia of the skin have been developed, a year has been known to

elapse without any considerable improvement, and permanent injury to the

health may be feared.

[195] _Ber. klin. Wochenschrift_, No. 32, 1866.

§ 212. =Post-mortem Appearances.=--The pathological appearances found

after sudden death from disulphide of carbon are but little different to

those found after fatal chloroform breathing.

§ 213. =Detection and Separation of Carbon Disulphide.=--The extreme

volatility of the liquid renders it easy to separate it from organic

liquids by distillation with reduced pressure in a stream of CO₂. Carbon

disulphide is best identified by (1) Hofman’s test, viz., passing the

vapour into an ethereal solution of triethyl-phosphin, (C₂H₅)₃P. Carbon

disulphide forms with triethyl-phosphin a compound which crystallises in

red scales. The crystals melt at 95° C., and have the following

formula--P(C₂H₅)₃CS₂. This will detect 0·54 mgrm. Should the quantity of

bisulphide be small, no crystals may be obtained, but the liquid will

become of a red colour. (2) CS₂ gives, with an alcoholic solution of

potash, a precipitate of potassic xanthate, CS₂C₂H₅OK.

§ 214. =Xanthogenic acid or ethyloxide-sulphocarbonate= (CS₂C₂H₅OH)

is prepared by decomposing potassic xanthogenate by diluted

hydrochloric or sulphuric acid. It is a colourless fluid, having an

unpleasant odour, and a weakly acid and rather bitter taste. It

burns with a blue colour, and is easily decomposed at 24°, splitting

up into ethylic alcohol and hydric sulphide. It is very poisonous,

and has an anæsthetic action similar to bisulphide of carbon. Its

properties are probably due to CS₂ being liberated within the body.

§ 215. =Potassic xanthogenate= (CS₂C₂H₅OK) and =potassic

xanthamylate= (CS₂C₅H₁₁OK) (the latter being prepared by the

substitution of amyl alcohol for ethyl alcohol), both on the

application of a heat below that of the body, develop CS₂, and are

poisonous, inducing symptoms very similar to those already detailed.

IX.--The Tar Acids--Phenol--Cresol.

§ 216. =Carbolic Acid. Syn. Phenol, Phenyl Alcohol, Phenylic Hydrate;

Phenic Acid; Coal-Tar Creasote.=--The formula for carbolic acid is

C₆H₅HO. The pure substance appears at the ordinary temperature as a

colourless solid, crystallising in long prisms; the fusibility of the

crystals is given variously by different authors: from my own

observation, the pure crystals melt at 40°-41°, any lower melting-point

being due to the presence of cresylic acid or other impurity; the

crystals again become solid about 15°. Melted carbolic acid forms a

colourless limpid fluid, sinking in water. It boils under the ordinary

pressure at 182°, and distils without decomposition; it is very readily

and completely distilled in a vacuum at about the temperature of 100°.

After the crystals have been exposed to the air, they absorb water, and

a hydrate is formed containing 16·07 per cent. of water. The hydrate

melts at 17°, any greater hydration prevents the crystallisation of the

acid; a carbolic acid, containing about 27 per cent. of water, and

probably corresponding to the formula C₆H₆O,2H₂O, is obtained by

gradually adding water to carbolic acid so long as it continues to be

dissolved. Such a hydrate dissolves in 11·1 times its measure of water,

and contains 8·56 per cent. of real carbolic acid. Carbolic acid does

not redden litmus, but produces a greasy stain on paper, disappearing on

exposure to the air; it has a peculiar smell, a burning numbing taste,

and in the fluid state it strongly refracts light. Heated to a high

temperature it takes fire, and burns with a sooty flame.

When an aqueous solution of carbolic acid is shaken up with ether,

benzene, carbon disulphide, or chloroform, it is fully dissolved by the

solvent, and is thus easily separated from most solutions in which it

exists in the free state. Petroleum ether, on the other hand, only

slightly dissolves it in the cold, more on warming. Carbolic acid mixes

in all proportions with glycerin, glacial or acetic acid, and alcohol.

It coagulates albumen, the precipitate being soluble in an excess of

albumen; it also dissolves iodine, without changing its properties. It

dissolves many resins, and also sulphur, but, on boiling, sulphuretted

hydrogen is disengaged. Indigo blue is soluble in hot carbolic acid, and

may be obtained in crystals on cooling. Carbolic acid is contained in

castoreum, a secretion derived from the beaver, but it has not yet been

detected in the vegetable kingdom. The source of carbolic acid is at

present coal-tar, from which it is obtained by a process of

distillation. There are, however, a variety of chemical actions in the

course of which carbolic acid is formed.

§ 217. The common disinfecting carbolic acid is a dark reddish liquid,

with a very strong odour; at present there is very little phenol in it;

it is mainly composed of meta- and para-cresol. It is officinal in

Germany, and there must contain at least 50 per cent. of the pure

carbolic acid. The pure crystallised carbolic acid is officinal in our

own and all the continental pharmacopœias. In the British Pharmacopœia,

a solution of carbolic acid in glycerin is officinal; the proportions

are 1 part of carbolic acid and 4 parts of glycerin, that is, strength

by measure = 20 per cent. The Pharmacopœia Germanica has a _liquor natri

carbolici_, made with 5 parts carbolic acid, 1 caustic soda, and 4 of

water; strength in carbolic acid = 50 per cent. There is also a strongly

alkaline crude sodic carbolate in use as a preservative of wood.

There are various disinfecting fluids containing amounts of carbolic

acid, from 10 per cent. upwards. Many of these are somewhat complex

mixtures, but, as a rule, any poisonous properties they possess are

mainly due to their content of phenol or cresol. A great variety of

disinfecting powders, under various names, are also in commerce,

deriving their activity from carbolic acid. Macdougall’s disinfecting

powder is made by adding a certain proportion of impure carbolic acid to

a calcic sulphite, which is prepared by passing sulphur dioxide over

ignited limestone.

=Calvert’s carbolic acid powder= is made by adding carbolic acid to the

siliceous residue obtained from the manufacture of aluminic sulphate

from shale. There are also various carbolates which, by heating or

decomposing with sulphuric acid, give off carbolic acid.

=Carbolic acid soaps= are also made on a large scale--the acid is free,

and some of the soaps contain as much as 10 per cent. In the inferior

carbolic acid soaps there is little or no carbolic acid, but cresylic

takes its place. Neither the soaps nor the powders have hitherto

attained any toxicological importance, but the alkaline carbolates are

very poisonous.

§ 218. =The chief uses= of carbolic acid are indicated by the foregoing

enumeration of the principal preparations used in medicine and commerce.

The bulk of the carbolic acid manufactured is for the purposes of

disinfection. It is also utilised in the preparation of certain

colouring matters or dyes, and during the last few years has had another

application in the manufacture of salicylic acid. In medicine it is

administered occasionally internally, while the antiseptic movement in

surgery, initiated by Lister, has given it great prominence in surgical

operations.

§ 219. =Statistics.=--The tar acids, _i.e._, pure carbolic acid and the

impure acids sold under the name of carbolic acid, but consisting (as

stated before) mainly of cresol, are, of all powerful poisons, the most

accessible, and the most recklessly distributed. We find them at the

bedside of the sick, in back-kitchens, in stables, in public and private

closets and urinals, and, indeed, in almost all places where there are

likely to be foul odours or decomposing matters. It is, therefore, no

wonder that poisoning by carbolic acid has, of late years, assumed large

proportions. The acid has become vulgarised, and quite as popularly

known, as the most common household drugs or chemicals.[196] This

familiarity is the growth of a very few years, since it was not

discovered until 1834, and does not seem to have been used by Lister

until about 1863. It was not known to the people generally until much

later. At present it occupies the third place in fatality of all

poisons in England. The following table shows that, in the past ten

years, carbolic acid has killed 741 people, either accidentally or

suicidally; there is also one case of murder by carbolic acid within the

same period, bringing the total up to 742:--

[196] Although this is so, yet much ignorance still prevails as to its

real nature. In a case reported in the _Pharm. Journ._, 1881, p. 334, a

woman, thirty years of age, drank two-thirds of an ounce of liquid

labelled “_Pure Carbolic Acid_” by mistake, and died in two hours. She

read the label, and a lodger also read it, but did not know what it

meant.

DEATHS FROM CARBOLIC ACID IN ENGLAND AND WALES DURING THE TEN YEARS

ENDING 1892.

ACCIDENT OR NEGLIGENCE.

Ages, 0-1 1-5 5-15 15-25 25-65 65 and Total

above

Males, 2 39 13 5 83 8 150

Females, 2 21 7 13 51 7 101

-------------------------------------------

Totals, 4 60 20 18 134 15 251

-------------------------------------------

SUICIDE.

Ages, 15-25 25-65 65 and Total

above

Males, 26 186 7 219

Females, 72 194 5 271

----------------------------

Totals, 98 380 12 490

----------------------------

Falck has collected, since the year 1868, no less than 87 cases of

poisoning from carbolic acid recorded in medical literature. In one of

the cases the individual died in nine hours from a large dose of

carbolate of soda; in a second, violent symptoms were induced by

breathing for three hours carbolic acid vapour; in the remaining 85, the

poisoning was caused by the liquid acid. Of these 85 persons, 7 had

taken the poison with suicidal intent, and of the 7, 5 died; 39 were

poisoned through the medicinal use of carbolic acid, 27 of the 39 by the

antiseptic treatment of wounds by carbolic acid dressings, and of these

8 terminated fatally; in 8 cases, symptoms of poisoning followed the

rubbing or painting of the acid on the skin for the cure of scabies,

favus, or psoriasis, and 6 of these patients died. In 4 cases, carbolic

acid enemata, administered for the purpose of dislodging ascarides, gave

rise to symptoms of poisoning, and in one instance death followed.

The substitution of carbolic acid for medicine happened as follows:--

Cases.

Taken instead of Tincture of Opium, 1

„ „ Infusion of Senna, 3

„ „ Mineral Water, 2

„ „ other Mixtures, 3

„ inwardly instead of applied outwardly, 3

Of these 12, 8 died.

Again, 10 persons took carbolic acid in mistake for various alcoholic

drinks, such as schnapps, brandy, rum, or beer, and 9 of the 10

succumbed; 17 persons drank carbolic acid simply “by mistake,” and of

these 13 died. Thus, of the whole 85 cases, no less than 51 ended

fatally--nearly 60 per cent.

It must be always borne in mind that, with regard to statistics

generally, the term “carbolic acid” is not used by coroners, juries, or

medical men, in a strictly chemical sense, the term being made to

include disinfecting fluids which are almost wholly composed of the

cresols, and contain scarcely any phenol. In this article, with regard

to symptoms and pathological appearances, it is only occasionally

possible to state whether the pure medicinal crystalline phenol or a

mixture of tar-acids was the cause of poisoning.

§ 220. =Fatal Dose.=--The minimum fatal dose for cats, dogs, and

rabbits, appears to be from ·4 to ·5 grm. per kilogram. Falck has put

the minimum lethal dose for man at 15 grms. (231·5 grains), which would

be about ·2 per kilo., basing his estimate on the following reasoning.

In 33 cases he had a fairly exact record of the amount of acid taken,

and out of the 33, he selects only those cases which are of use for the

decision of the question. Among adults, in 5 cases the dose was 30

grms., and all the 5 cases terminated by death, in times varying from

five minutes to an hour and a half. By other 5 adults a dose of 15 grms.

was taken; of the 5, 3 men and a woman died, in times varying from

forty-five minutes to thirty hours, while 1 woman recovered. Doses of

11·5, 10·8, and 9 grms. were taken by different men, and recovered from;

on the other hand, a suicide who took one and a half teaspoonful (about

6 grms.) of the concentrated acid, died in fifty minutes. Doses of ·3 to

3 grms. have caused symptoms of poisoning, but the patients recovered,

while higher doses than 15 grms. in 12 cases, with only one exception,

caused death. Hence, it may be considered tolerably well established,

that 15 grms. (231·5 grains) may be taken as representing the minimum

lethal dose.

The largest dose from which a person appears to have recovered is, I

believe, that given in a case recorded by Davidson, in which 150 grms.

of crude carbolic acid had been taken. It must, however, be remembered

that, as this was the impure acid, probably only half of it was really

carbolic acid. The German Pharmacopœia prescribes as a maximum dose ·05

grm (·7 grain) of the crystallised acid, and a daily maximum quantity

given in divided doses of ·15 grm. (2·3 grains).

§ 221. =Effects on Animals.=--Carbolic acid is poisonous to both animal

and vegetable life.

=Infusoria.=--One part of the acid in 10,000 parts of water rapidly

kills ciliated animalcules,--the movements become sluggish, the sarcode

substance darker, and the cilia in a little time cease moving.

=Fish.=--One part of the acid in 7000 of water kills dace, minnows,

roach, and gold fish. In this amount of dilution the effect is not

apparent immediately; but, at the end of a few hours, the movements of

the fish become sluggish, they frequently rise to the surface to

breathe, and at the end of twenty-four hours are found dead. Quantities

of carbolic acid, such as 1 part in 100,000 of water, appear to affect

the health of fish, and render them more liable to be attacked by the

fungus growth which is so destructive to fish-life in certain years.

=Frogs.=--If ·01 to ·02 grm. of carbolic acid be dissolved in a litre of

water in which a frog is placed, there is almost immediately signs of

uneasiness in the animal, showing that pain from local contact is

experienced; a sleepy condition follows, with exaltation of reflex

sensibility; convulsions succeed, generally, though not always; then

reflex sensibility is diminished, ultimately vanishes, and death occurs;

the muscles and nerves still respond to the electric current, and the

heart beats, but slowly and weakly, for a little after the respiration

has ceased.

§ 222. =Warm-blooded Animals.=--For a rabbit of the average weight of 2

kilos., ·15 grm. is an active dose, and ·3 a lethal dose (that is ·15

per kilo.). The sleepy condition of the frog is not noticed, and the

chief symptoms are clonic convulsions with dilatation of the pupils, the

convulsions passing into death, without a noticeable paralytic stage.

The symptoms observed in poisoned dogs are almost precisely similar, the

dose, according to body-weight, being the same. It has, however, been

noticed that with doses large enough to produce convulsions, a weak

condition has supervened, causing death in several days. There appears

to be no cumulative action, since equal toxic doses can be given to

animals for some time, and the last dose has no greater effect than the

first or intermediate ones. The pathological appearances met with in

animals poisoned by the minimum lethal doses referred to are not

characteristic; but there is a remarkable retardation of putrefaction.

§ 223. =Symptoms in Man, external application.=--A 5 per cent. solution

of carbolic acid, applied to the skin, causes a peculiar numbness,

followed, it may be, by irritation. Young subjects, and those with

sensitive skins, sometimes exhibit a pustular eruption, and concentrated

solutions cause more or less destruction of the skin. Lemaire[197]

describes the action of carbolic acid on the skin as causing a slight

inflammation, with desquamation of the epithelium, followed by a very

permanent brown stain, but this he alone has observed. Applied to the

mucous membrane, carbolic acid turns the epithelial covering white; the

epithelium, however, is soon thrown off, and the place rapidly heals;

there is the same numbing, aconite-like feeling before noticed. The

vapour of carbolic acid causes redness of the conjunctivæ, and

irritation of the air-passages. If the application is continued, the

mucous membrane swells, whitens, and pours out an abundant secretion.

[197] Lemaire, Jul., “_De l’Acide phénique_,” Paris, 1864.

Dr. Whitelock, of Greenock, has related two instances in which children

were treated with carbolic acid lotion (strength 2½ per cent.) as an

application to the scalp for ringworm; in both, symptoms of poisoning

occurred--in the one, the symptoms at once appeared; in the other they

were delayed some days. In order to satisfy his mind, the experiment was

repeated twice, and each time gastric and urinary troubles followed.

Nussbaum, of Munich, records a case[198] in which symptoms were induced

by the forcible injection of a solution of carbolic acid into the cavity

of an abscess.

[198] _Leitfaden zur antiseptischer Wundbehandlung_, 141.

Macphail[199] gives two cases of poisoning by carbolic acid from

external use. In the one, a large tumour had been removed from a woman

aged 30, and the wound covered with gauze steeped in a solution of

carbolic acid, in glycerin, strength 10 per cent.; subsequently, there

was high fever, with diminished sulphates in the urine, which smelt

strongly of carbolic acid, and was very dark. On substituting boracic

acid, none of these troubles were observed. The second case was that of

a servant suffering from axillary abscess; the wound was syringed out

with carbolic acid solution, of strength 2½ per cent., when effects were

produced similar to those in the first case. It was noted that in both

these cases the pulse was slowed. Scattered throughout surgical and

medical literature, there are many other cases recorded, though not all

so clear as those cited. Several cases are also on record in which

poisonous symptoms (and even death) have resulted from the application

of carbolic acid lotion as a remedy for scabies or itch.

[199] “Carbolic Acid Poisoning (Surgical),” by S. Rutherford Macphail,

M.B., _Ed. Med. Journal_, cccxiv., Aug. 1881, p. 134.

A surgeon prescribed for two joiners who suffered from scabies a lotion,

which was intended to contain 30 grms. of carbolic acid in 240 c.c. of

water; but the actual contents of the flasks were afterwards from

analysis estimated by Hoppe-Seyler to be 33·26 grms., and the quantity

used by each to be equal to 13·37 grms. (206 grains) of carbolic acid.

One of the men died; the survivor described his own symptoms as

follows:--He and his companion stood in front of the fire, and rubbed

the lotion in; he rubbed it into his legs, breast, and the front part of

his body; the other parts were mutually rubbed. Whilst rubbing his right

arm, and drying it before the fire, he felt a burning sensation, a

tightness and giddiness, and mentioned his sensations to his companion,

who laughed. This condition lasted from five to seven minutes, but he

did not remember whether his companion complained of anything, nor did

he know what became of him, nor how he himself came to be in bed. He was

found holding on to the joiner’s bench, looking with wide staring eyes,

like a drunken man, and was delirious for half an hour. The following

night he slept uneasily and complained of headache and burning of the

skin. The pulse was 68, the appearance of the urine, appetite, and sense

of taste were normal; the bowels confined. He soon recovered.

The other joiner seems to have died as suddenly as if he had taken

prussic acid. He called to his mother, “_Ich habe einen Rausch_,” and

died with pale livid face, after taking two deep, short inspirations.

The _post-mortem_ examination showed the sinuses filled with much fluid

blood, and the vessels of the pia mater congested. Frothy, dark, fluid

blood was found in the lungs, which were hyperæmic; the mucous tissues

of the epiglottis and air-tubes were reddened, and covered with a frothy

slime. Both ventricles--the venæ cavæ and the vessels of the spleen and

kidneys--were filled with dark fluid blood. The muscles were very red;

there was no special odour. Hoppe-Seyler recognised carbolic acid in the

blood and different organs of the body.[200]

[200] R. Köhler, _Würtem. Med. Corr. Bl._, xlii., No. 6, April 1872; H.

Abelin, _Schmidt’s Jahrbücher_, 1877, Bd. 173, S. 163.

In another case, a child died from the outward use of a 2 per cent.

solution of carbolic acid. It is described as follows:--An infant of

seven weeks old suffered from varicella, and one of the pustules became

the centre of an erysipelatous inflammation. To this place a 2 per cent.

solution of carbolic acid was applied by means of a compress steeped in

the acid; the following morning the temperature rose from 36·5° (97·7°

F.) to 37° (98·6° F.), and poisonous symptoms appeared. The urine was

coloured dark. There were sweats, vomitings, and contracted pupils,

spasmodic twitchings of the eyelids and eyes, with strabismus, slow

respiration, and, lastly, inability to swallow. Under the influence of

stimulating remedies the condition temporarily improved, but the child

died twenty-three and a half hours after the first application. An

examination showed that the vessels of the brain and the tissue of the

lungs were abnormally full of blood. The liver was softer than natural,

and exhibited a notable yellowishness in the centre of the acini.

Somewhat similar appearances were noticed in the kidneys, the

microscopic examination of which showed the _tubuli contorti_ enlarged

and filled with fatty globules. In several places the epithelium was

denuded, in other places swollen, and with the nuclei very visible.

In an American case,[201] death followed the application of carbolic

acid to a wound. A boy had been bitten by a dog, and to the wound, at

one o’clock in the afternoon, a lotion, consisting of nine parts of

carbolic acid and one of glycerin, was applied. At seven o’clock in the

evening the child was unconscious, and died at one o’clock the following

day.

[201] _American Journal of Pharmacy_, vol. li., 4th Ser.; vol. ix.,

1879, p. 57.

§ 224. =Internal Administration.=--Carbolic acid may be taken into the

system, not alone by the mouth, but by the lungs, as in breathing

carbolic acid spray or carbolic acid vapour. It is also absorbed by the

skin when outwardly applied, or in the dressing or the spraying of

wounds with carbolic acid. Lastly, the ordinary poisonous effects have

been produced by absorption from the bowel, when administered as an

enema. When swallowed undiluted, and in a concentrated form, the

symptoms may be those of early collapse, and speedy death. Hence, the

course is very similar to that witnessed in poisoning by the mineral

acids.

If lethal, but not excessive doses of the diluted acid are taken, the

symptoms are--a burning in the mouth and throat, a peculiarly unpleasant

persistent taste, and vomiting. There is faintness with pallor of the

face, which is covered by a clammy sweat, and the patient soon becomes

unconscious, the pulse small and thready, and the pupils sluggish to

light. The respiration is profoundly affected; there is dyspnœa, and the

breathing becomes shallow. Death occurs from paralysis of the

respiratory apparatus, and the heart is observed to beat for a little

after the respiration has ceased. All these symptoms may occur from the

application of the acid to the skin or to mucous membranes, and have

been noticed when solutions of but moderate strength have been

used--e.g., there are cases in gynæcological practice in which the

mucous membrane (perhaps eroded) of the uterus has been irrigated with

carbolic acid injections. Thus, Küster[202] relates a case in which,

four days after confinement, the uterus was washed out with a 2 per

cent. solution of carbolic acid without evil result. Afterwards a 5 per

cent. solution was used, but it at once caused violent symptoms of

poisoning, the face became livid, clonic convulsions came on, and at

first loss of consciousness, which after an hour returned. The patient

died on the ninth day. There was intense diphtheria of the uterus and

vagina. Several other similar cases (although not attended with such

marked or fatal effects) are on record.[203]

[202] _Centralblatt. f. Gynäkologie_, ii. 14, 1878.

[203] A practitioner in Calcutta injected into the bowel of a boy, aged

5, an enema of diluted carbolic acid, which, according to his own

statement, was 1 part in 60, and the whole quantity represented 144

grains of the acid. The child became insensible a few minutes after the

operation, and died within four hours. There was no _post-mortem_

examination; the body smelt strongly of carbolic acid.--_Lancet_, May

19, 1883.

§ 225. The symptoms of carbolic acid poisoning admit of considerable

variation from those already described. The condition is occasionally

that of deep coma. The convulsions may be general, or may affect only

certain groups of muscles. Convulsive twitchings of the face alone, and

also muscular twitchings only of the legs, have been noticed. In all

cases, however, a marked change occurs in the urine. Subissi[204] has

noted the occurrence of abortion, both in the pig and the mare, as a

result of carbolic acid, but this effect has not hitherto been recorded

in the human subject.

[204] _L’Archivio della Veterinaria Ital._, xi., 1874.

It has been experimentally shown by Küster, that previous loss of blood,

or the presence of septic fever, renders animals more sensitive to

carbolic acid. It is also said that children are more sensitive than

adults.

The course of carbolic acid poisoning is very rapid. In 35 cases

collected by Falck, in which the period from the taking of the poison to

the moment of death was accurately noted, the course was as follows:--12

patients died within the first hour, and in the second hour 3; so that

within two hours 15 died. Between the third and the twelfth hour, 10

died; between the thirteenth and the twenty-fourth hour, 7 died; and

between the twenty-fifth and the sixtieth hour, only 3 died. Therefore,

slightly over 71 per cent. died within twelve hours, and 91·4 per cent.

within the twenty-four hours.

§ 226. =Changes in the Urine.=--The urine of patients who have absorbed

in any way carbolic acid is dark in colour, and may smell strongly of

the acid. It is now established--chiefly by the experiments and

observations of Baumann[205]--that carbolic acid, when introduced into

the body, is mainly eliminated in the form of phenyl-sulphuric acid,

C₆H₅HSO₄, or more strictly speaking as potassic phenyl-sulphate,

C₆H₅KSO₄, a substance which is not precipitated by chloride of barium

until it has been decomposed by boiling with a mineral acid. Cresol is

similarly excreted as cresol-sulphuric acid, C₆H₄CH₃HSO₄, ortho-, meta-,

or para-, according to the kind of cresol injected; a portion may also

appear as hydro-tolu-chinone-sulphuric acid. Hence it is that, with

doses of phenol or cresol continually increasing, the amount of

sulphates naturally in the urine (as estimated by simply acidifying with

hydrochloric acid, and precipitating in the cold with chloride of

barium) continually decreases, and may at last vanish, for all the

sulphuric acid present is united with the phenol. On the other hand, the

precipitate obtained by prolonged boiling of the strongly acidified

urine, after filtering off any BaSO₄ thrown down in the cold, is ever

increasing.

[205] _Pflüger’s Archiv_, 13, 1876, 289.

Thus, a dog voided urine which contained in 100 c.c., ·262 grm. of

precipitable sulphuric acid, and ·006 of organically-combined sulphuric

acid; his back was now painted with carbolic acid, and the normal

proportions were reversed, the precipitable sulphuric acid became ·004

grm., while the organically-combined was ·190 in 100 c.c. In addition to

phenyl-sulphuric acid, it is now sufficiently established[206] that

hydroquinone

( OH)

(C₆H₄ )

( OH)

(paradihydroxyl phenol) and pyrocatechin

( OH)

(C₆H₄ )

( OH)

(orthodihydroxyl phenol) are constant products of a portion of the

phenol. The hydroquinone appears in the urine, in the first place, as

the corresponding ether-sulphuric acid, which is colourless; but a

portion of it is set free, and this free hydroquinone (especially in

alkaline urine) is quickly oxidised to a brownish product, and hence the

peculiar colour of urine. Out of dark coloured carbolic acid urine the

hydroquinone and its products of decomposition can be obtained by

shaking with ether; on separation of the ether, an extract is obtained,

reducing alkaline silver solution, and developing quinone on warming

with ferric chloride.

[206] E. Baumann and C. Preuss, _Zeitschrift f. phys. Chemie_, iii. 156;

_Anleitung zur Harn-Analyse_, W. F. Löbisch, Leipzig, 1881, pp. 142,

160; Schmiedeberg, _Chem. Centrbl._ (3), 13, 598.

To separate pyro-catechin, 200 c.c. of urine may be evaporated to an

extract, the extract treated with strong alcohol, the alcoholic liquid

evaporated, and the extract then treated with ether. On separation and

evaporation of the ether, a yellowish mass is left, from which the

pyro-catechin may be extracted by washing with a small quantity of

water. This solution will reduce silver solution in the cold, or, if

treated with a few drops of ferric chloride solution, show a marked

green colour, changing on being alkalised by a solution of sodic

hydro-carbonate to violet, and then on being acidified by acetic acid,

changing back again to green. According to Thudichum,[207] the urine of

men and dogs, after the ingestion of carbolic acid, contains a blue

pigment.

[207] _On the Pathology of the Urine_, Lond., 1877, p. 198.

§ 227. =The Action of Carbolic Acid considered

physiologically.=--Researches on animals have elucidated, in a great

measure, the mode in which carbolic acid acts, and the general sequence

of effects, but there is still much to be learnt.

E. Küster[208] has shown that the temperature of dogs, when doses of

carbolic acid in solution are injected subcutaneously, or into the

veins, is immediately, or very soon after the operation, raised. With

small and moderate doses, this effect is but slight--from half to a

whole degree--on the day after the injection the temperature sinks below

the normal point, and only slowly becomes again natural. With doses that

are just lethal, first a rise and then a rapid sinking of temperature

are observed; but with those excessive doses which speedily kill, the

temperature at once sinks without a preliminary rise. The action on the

heart is not very marked, but there is always a slowing of the cardiac

pulsations; according to Hoppe-Seyler the arteries are relaxed. The

respiration is much quickened; this acceleration is due to an

excitement of the vagus centre, since Salkowsky has shown that section

of the vagus produces a retardation of the respiratory wave. Direct

application of the acid to muscles or nerves quickly destroys their

excitability without a previous stage of excitement. The main cause of

the lethal action of carbolic acid--putting on one side those cases in

which it may kill by its local corrosive action--appears to be paralysis

of the respiratory nervous centres. The convulsions arise from the

spinal cord. On the cessation of the convulsions, the superficial nature

of the breathing assists other changes by preventing the due oxidation

of the blood.

[208] _Archiv f. klin. Chirurgie_, Bd. 23, S. 133, 1879.

§ 228. Carbolic acid is separated from the body in the forms already

mentioned, a small portion is also excreted by the skin. Salkowsky

considers that, with rabbits, he has also found oxalic acid in the urine

as an oxidation product. According to the researches of Binnendijk,[209]

the separation of carbolic acid by the urine commences very quickly

after its ingestion; and, under favourable circumstances, it may be

completely excreted within from twelve to sixteen hours. It must be

remembered that normally a small amount of phenol may be present in the

animal body, as the result of the digestion of albuminous substances or

of their putrefaction. The amount excreted by healthy men when feeding

on mixed diet, Engel,[210] by experiment, estimates to be in the

twenty-four hours 15 mgrms.

[209] _Journal de Pharmacie et de Chimie._

[210] _Annal. de Chimie et de Physique_, 5 Sér. T. 20, p. 230, 1880.

§ 229. =Post-mortem Appearances.=--No fact is better ascertained from

experiments on animals than the following:--That with lethal doses of

carbolic acid, administered by subcutaneous injection, or introduced by

the veins, no appearances may be found after death which can be called

at all characteristic. Further, in the cases in which death has occurred

from the outward application of the acid for the cure of scabies, &c.,

no lesion was ascertained after death which could--apart from the

history of the case and chemical evidence--with any confidence be

ascribed to a poison.

On the other hand, when somewhat large doses of the acid are taken by

the mouth, very coarse and appreciable changes are produced in the upper

portion of the alimentary tract. There may be brownish, wrinkled spots

on the cheek or lips; the mucous membrane of the mouth, throat, and

gullet is often white, and if the acid was concentrated, eroded. The

stomach is sometimes thickened, contracted, and blanched, a condition

well shown in a pathological preparation (ix. 206, 43 _f_) in St.

George’s Hospital. The mucous membrane, indeed, may be quite as much

destroyed as if a mineral acid had been taken. Thus, in Guy’s Hospital

museum (1799⁴⁰), there is preserved the stomach of a child who died

from taking accidentally carbolic acid. It looks like a piece of paper,

and is very white, with fawn-coloured spots; the rugæ are absent, and

the mucous membrane seems to have entirely vanished. Not unfrequently

the stomach exhibits white spots with roundish edges. The duodenum is

often affected, and the action is not always limited to the first part

of the intestine.

The respiratory passages are often inflamed, and the lungs infiltrated

and congested. As death takes place from an asphyxiated condition, the

veins of the head and brain, and the blood-vessels of the liver, kidney

and spleen, are gorged with blood, and the right side of the heart

distended, while the left is empty. On the other hand, a person may die

of sudden nervous shock from the ingestion of a large quantity of the

acid, and in such a case the _post-mortem_ appearances will not then

exhibit precisely the characters just detailed. Putrefaction is retarded

according to the dose, and there is often a smell of carbolic acid.[211]

If any urine is contained in the bladder, it will probably be dark, and

present the characters of carbolic urine, detailed at p. 174.

[211] In order to detect this odour, it is well to open the head first,

lest the putrefaction of the internal viscera be so great as to mask the

odour.

Tests for Carbolic Acid.

§ 230. 1. =The Pinewood Test.=--Certain pinewood gives a beautiful blue

colour when moistened first with carbolic acid, and afterwards with

hydrochloric acid, and exposed to the light. Some species of pine give a

blue colour with hydrochloric acid alone, and such must not be used;

others do not respond to the test for carbolic acid. Hence it is

necessary to try the chips of wood first, to see how they act, and with

this precaution the test is very serviceable, and, in cautious hands, no

error will be made.

2. =Ammonia and Hypochlorite Test.=--If to a solution containing even so

small a quantity as 1 part of carbolic acid in 5000 parts of water,

first, about a quarter of its volume of ammonia hydrate be added, and

then a small quantity of sodic hypochlorite solution, avoiding excess, a

blue colour appears, warming quickens the reaction: the blue is

permanent, but turns to red with acids. If there is a smaller quantity

than the above proportion of acid, the reaction may be still produced

feebly after standing for some time.

3. =Ferric Chloride.=--One part of phenol in 3000 parts of water can be

detected by adding a solution of ferric chloride; a fine violet colour

is produced. This is also a very good test, when applied to a

distillate; but if applied to a complex liquid, the disturbing action of

neutral salts and other substances may be too great to make the

reaction under those circumstances of service.

4. =Bromine.=--The most satisfactory test of all is treatment of the

liquid by bromine-water. A precipitate of tri-bromo-phenol (C₆H₃Br₃O) is

rapidly or slowly formed, according to the strength of the solution; in

detecting very minute quantities the precipitate must be given time to

form. According to Allen,[212] a solution containing but 1/60000 of

carbolic acid gave the reaction after standing twenty-four hours.

[212] _Commercial Organic Analysis_, vol. i. p. 306.

The properties of the precipitate are as follows:--It is crystalline,

and under the microscope is seen to consist of fine stars of needles;

its smell is peculiar; it is insoluble in water and acid liquids, but

soluble in alkalies, ether, and absolute alcohol; a very minute quantity

of water suffices to precipitate it from an alcoholic solution; it is

therefore essential to the success of the test that the watery liquid to

be examined is either neutral or acid in reaction.

§ 231. Tri-bromo-phenol may be used for the quantitative estimation of

carbolic acid, 100 parts of tri-bromo-phenol are equal to 29·8 of

carbolic acid; by the action of sodium amalgam, tri-bromo-phenol is

changed back into carbolic acid.

That bromine-water precipitates several volatile and fixed alkaloids

from their solutions is no objection to the bromine test, for it may be

applied to a distillation product, the bases having been previously

fixed by sulphuric acid. Besides, the properties of tri-bromo-phenol are

distinct enough, and therefore there is no valid objection to the test.

It is the best hitherto discovered. There are also other reactions, such

as that Millon’s reagent strikes a red--molybdic acid, in concentrated

sulphuric acid, a blue--and potassic dichromate, with sulphuric acid, a

brown colour--but to these there are objections. Again, we have the

_Euchlorine_ test, in which the procedure is as follows:--A test-tube is

taken, and concentrated hydrochloric acid is allowed to act therein upon

potassic chlorate. After the gas has been evolved for from 30 to 40

seconds, the liquid is diluted with 1½ volume of water, the gas removed

by blowing through a tube, and solution of strong ammonia poured in so

as to form a layer on the top; after blowing out the white fumes of

ammonium chloride, a few drops of the sample to be tested are added. In

the presence of carbolic acid, a rose-red, blood-red, or red-brown tint

is produced, according to the quantity present. Carbolic acid may be

confounded with _cresol_ or with _creasote_, but the distinction between

pure carbolic acid, pure cresol, and creasote is plain.

§ 232. =Cresol (Cresylic Acid, Methyl-phenol)=,

C₆H₄ .

CH₃

--There are three cresols--ortho-, meta-, and para-. Ordinary

commercial cresol is a mixture of the three, but contains but little

ortho-cresol; the more important properties of the pure cresols are set

out in the following table:--

+--------+-----------------+----------------+---------------------+

+--------+-----------------+----------------+---------------------+

|Ortho-, | 31-31·5° C. | 188·0° | Salicylic Acid |

| | | | |

| | | | |

|Para-, | 36° | 198° |Para-oxybenzoic acid.|

+--------+-----------------+----------------+---------------------+

Pure ortho-, meta-, or para-cresol have been obtained by synthetical

methods; they cannot be said to be in ordinary commerce.

=Commercial cresol= is at ordinary temperatures a liquid, and cannot be

obtained in a crystalline state by freezing. Its boiling-point is from

198° to 203°; it is almost insoluble in strong ammonia, and, when 16

volumes are added, it then forms crystalline scales. On the other hand,

carbolic acid is soluble in an equal volume of ammonia, and is then

precipitated by the addition of 1½ volume of water. Cresol is insoluble

in small quantities of pure 6 per cent. soda solution; with a large

excess, it forms crystalline scales; while carbolic acid is freely

soluble in small or large quantities of alkaline solutions.

Cold petroleum spirit dissolves cresol, but no crystalline scales can be

separated out by a freezing mixture. Carbolic acid, on the contrary, is

but sparingly soluble in cold petroleum, and a solution of carbolic acid

in hot petroleum, when exposed to sudden cold produced by a freezing

mixture, separates out crystals from the upper layer of liquid. Cresol

is miscible with glycerin of specific gravity 1·258 in all proportions;

1 measure of glycerin mixed with 1 measure of cresol is completely

precipitated by 1 measure of water. Carbolic acid, under the same

circumstances, is not precipitated. The density of cresol is about

1·044. It forms with bromine a tri-bromo-cresol, but this is liquid at

ordinary temperatures, while tri-bromo-phenol is solid. On the other

hand, it resembles carbolic acid in its reactions with ferric chloride

and with nitric and sulphuric acid.

§ 233. =Creasote= or =Kreozote= is a term applied to the mixture of

crude phenols obtained from the distillation of wood-tar. It

consists of a mixture of substances of which the chief are guaiacol

or oxycresol (C₇H₈O₂), boiling at 200°, and creasol (C₈H₁₀O₂),

boiling at 217°; also in small quantities phlorol (C₈H₁₀O), methyl

creasol (C₉H₁₂O₂), and other bodies. Morson’s English creasote is

prepared from Stockholm tar, and boils at about 217°, consisting

chiefly of creasol; it is not easy, by mere chemical tests, to

distinguish creasote from cresylic acid. Creasote, in its reactions

with sulphuric and nitric acid, bromine and gelatin, is similar to

carbolic and cresylic acids, and its solubility in most solvents is

also similar. It is, however, distinguished from the tar acids by

its insolubility in Price’s glycerin, specific gravity 1·258,

whether 1, 2, or 3 volumes of glycerin be employed. But the best

test is its action on an ethereal solution of nitro-cellulose.

Creasote mixes freely with the B.P. collodium, while cresylic acid

or carbolic acid at once coagulates the latter. With complicated

mixtures containing carbolic acid, cresol, and creasote, the only

method of applying these tests with advantage is to submit the

mixture to fractional distillation.

Flückiger[213] tests for small quantities of carbolic acid in

creasote, by mixing a watery solution of the sample with one-fourth

of its volume of ammonia hydrate, wetting the inside of a porcelain

dish with this solution, and then carefully blowing bromine fumes on

to the surface. A fine blue colour appears if carbolic acid is

present, but if the sample consists of creasote only, then it is

dirty green or brown. Excess of bromine spoils the reaction.[214]

[213] _Arch. der Pharmacie_, cxiii. p. 30.

[214] Creasote is, without doubt, poisonous, though but little is known

of its action, and very few experiments are on record in which pure

creasote has been employed. Eulenberg has studied the symptoms in

rabbits, by submitting them to vaporised creasote--_i.e._, the vapour

from 20 drops of creasote diffused through a glass shade under which a

rabbit was confined. There was at once great uneasiness, with a watery

discharge from the eyes, and after seven minutes the rabbit fell on its

side, and was slightly convulsed. The cornea was troubled, and the eyes

prominent; a white slime flowed from the mouth and eyes. After fifteen

minutes there was narcosis, with lessened reflex action; the temperature

was almost normal. There was rattling breathing, and in half an hour the

animal died, the respiration ceasing, and fluid blood escaping from the

nose. Section after death showed the brain to be hyperæmic, the mucous

membranes of the air-passages to be covered with a thin layer of fluid

blood, and the lungs to be congested; the right side of the heart was

gorged with fluid blood.

The _post-mortem_ appearances and the symptoms generally are, therefore,

closely allied to those produced by carbolic acid. A dark colour of the

urine has also been noticed.

§ 234. =Carbolic Acid in Organic Fluids or in the Tissues of the

Body.=--If the routine process given at page 51, where the organic fluid

is distilled in a vacuum after acidifying with tartaric acid, is

employed, phenol or cresol, if present, will certainly be found in the

distillate. If, however, a special search be made for the acids, then

the fluid must be well acidified with sulphuric acid, and distilled in

the usual way. The distillation should be continued as long as possible,

and the distillate shaken up with ether in the apparatus figured at page

156. On separation and evaporation of the ether, the tar acids, if

present, will be left in a pure enough form to show its reactions. The

same process applies to the tissues, which, in a finely-divided state,

are boiled and distilled with dilute sulphuric acid, and the distillate

treated as just detailed.

Like most poisons, carbolic acid has a selective attraction for certain

organs, so that, unless all the organs are examined, it is by no means

indifferent which particular portion is selected for the inquiry.

Hoppe-Seyler applied carbolic acid to the abdomen and thighs of dogs,

and when the symptoms were at their height bled them to death, and

separately examined the parts. In one case, the blood yielded ·00369 per

cent.; the brain, ·0034 per cent.; the liver, ·00125; and the kidneys,

·00423 per cent. of their weight of carbolic acid. The liver then

contains only one-third of the quantity found in an equal weight of

blood, and, therefore, the acid has no selective affinity for that

organ. On the other hand, the nervous tissue, and especially the

kidneys, appear to concentrate it.

§ 235. =Examination of the Urine for Phenol or Cresol.=--It has been

previously stated (see p. 174) that the urine will not contain these as

such, but as compounds--viz., phenyl or cresyl sulphate of potassium. By

boiling with a mineral acid, these compounds may be broken up, and the

acids obtained, either by distillation or by extraction with ether. To

detect very minute quantities, a large quantity of the urine should be

evaporated down to a syrup, and treated with hydrochloric acid and

ether. On evaporating off the ether, the residue should be distilled

with dilute sulphuric acid, and this distillate then tested with

bromine-water, and the tri-bromo-phenol or cresol collected, identified,

and weighed.

Thudichum[215] has separated crystals of potassic phenyl-sulphate itself

from the urine of patients treated endermically by carbolic acid, as

follows:--

[215] _Pathology of the Urine_, p. 193.

The urine was evaporated to a syrup, extracted with alcohol of 90 per

cent., treated with an alcoholic solution of oxalic acid as long as this

produced a precipitate, and then shaken with an equal volume of ether.

The mixture was next filtered, neutralised with potassic carbonate,

evaporated to a small bulk, and again taken up with alcohol. Some

oxalate and carbonate of potassium were separated, and, on evaporation

to a syrup, crystals of potassic phenyl-sulphate were obtained. They

gave to analysis 46·25 per cent. H₂SO₄, and 18·1 K--theory requiring

46·2 of H₂SO₄ and 18·4 of K. Alkaline phenyl-sulphates strike a deep

purple colour with ferric chloride. To estimate the amount of

phenyl-sulphate or cresol-sulphate in the urine, the normal sulphates

may be separated by the addition of chloride of barium in the cold,

first acidifying with hydrochloric acid. On boiling the liquid a second

crop of sulphate is obtained, due to the breaking up of the compound

sulphate, and from this second weight the amount of acid can be

obtained, _e.g._, in the case of phenol--C₆H₅HSO₄ : BaSO₄ :: 174 : 233.

§ 236. =Assay of Disinfectants, Carbolic Acid Powders, &c.=--For the

assay of crude carbolic acid, Mr. Charles Lowe[216] uses the

following process:--A thousand parts of the sample are distilled

without any special condensing arrangement; water first comes over,

and is then followed by an oily fluid. When a hundred parts of the

latter, as measured in a graduated tube, have been collected, the

receiver is changed. The volume of water is read off. If the oily

liquid floats on the water, it contains light oil of tar; if it is

heavier than the water, it is regarded as hydrated acid, containing

50 per cent. of real carbolic acid. The next portion consists of

anhydrous cresylic and carbolic acids, and 625 volumes are distilled

over; the remainder in the retort consists wholly of cresylic acid

and the higher homologues. The relative proportions of carbolic and

cresylic acids are approximately determined by taking the

solidifying point, which should be between 15·5° and 24°, and having

ascertained this temperature, imitating it by making mixtures of

known proportions of carbolic and cresylic acids.

[216] _Allen’s Commercial Organic Analysis_, vol. i. p. 311.

E. Waller[217] has recommended the following process for the

estimation of carbolic acid. It is based on the precipitation of the

tar acids by bromine, and, of course, all phenols precipitated in

this way will be returned as carbolic acid. The solutions necessary

are--

[217] _Chem. News_, April 1, 1881, p. 152.

1. A solution containing 10 grms. of pure carbolic acid to the

litre; this serves as a standard solution.

2. A solution of bromine in water.

3. Solution of alum in dilute sulphuric acid. A litre of 10 per

cent. sulphuric acid is shaken with alum crystals until saturated.

The actual process is as follows:--10 grms. of the sample are

weighed out and run into a litre flask, water added, and the mixture

shaken. The flask being finally filled up to the neck, some of the

solution is now filtered through a dry filter, and 10 c.c. of this

filtrate is placed in a 6 or 8-ounce stoppered bottle, and 30 c.c.

of the alum solution added. In a similar bottle 10 c.c. of the

standard solution of carbolic acid are placed, and a similar

quantity of alum solution is added, as in the first bottle. The

bromine-water is now run into the bottle containing the standard

solution of carbolic acid from a burette until there is no further

precipitate; the bottle is stoppered and shaken after every

addition. Towards the end of the reaction the precipitate forms but

slowly, and when the carbolic acid is saturated, the slight excess

of bromine-water gives the solution a pale yellow tint. The solution

from the sample is treated in the same way, and from the amount of

bromine-water used, the percentage of the sample is obtained by

making the usual calculations. Thus, supposing that 5 c.c. of the

standard required 15 c.c. of the bromine-water for precipitation,

and 10 c.c. of the solution of the sample required 17 c.c., the

calculation would be 15 × 2 : 17 = 100 : _x_ per cent. With most

samples of crude carbolic acid, the precipitate does not readily

separate. It is then best to add a little of the precipitate already

obtained by testing the standard solution, which rapidly clears the

liquid.

=Koppeschaar’s volumetric method= is more exact, but also more

elaborate, than the one just described. Caustic normal soda is

treated with bromine until permanently yellow, and the excess of

bromine is then driven off by boiling. The liquid now contains 5NaBr

+ NaBrO₃, and on adding this to a solution containing carbolic acid,

and a sufficient quantity of hydrochloric acid to combine with the

sodium, the following reactions occur:--

(1.) 5NaBr + NaBrO₃ + 6HCl = 6NaCl + 6Br + 3H₂O;

and

(2.) C₆H₆O + 6Br = C₆H₃Br₃O + 3HBr.

Any excess of bromine liberated in the first reaction above that

necessary for the second, will exist in the free state, and from the

amount of bromine which remains free the quantity of carbolic acid

can be calculated, always provided the strength of the bromine

solution is first known. The volumetric part of the analysis,

therefore, merely amounts to the determination of free bromine,

which is best found by causing it to react on potassium iodide, and

ascertaining the amount of free iodine by titration with a standard

solution of sodium thiosulphate. In other words, titrate in this way

the standard alkaline bromine solution, using as an indicator starch

paste until the blue colour disappears. Another method of indicating

the end of the reaction is by the use of strips of paper first

soaked in starch solution, and dried, and then the same papers

moistened with zinc iodide, and again dried; the least excess of

bromine sets free iodine, and strikes a blue colour.

=Colorimetric Method of Estimation.=--A very simple and ever-ready

way of approximately estimating minute quantities of the phenols

consists in shaking up 10 grms. of the sample with water, allowing

any tar or insoluble impurities to subside. Ten c.c. of the clear

fluid are then taken, and half a c.c. of a 5 per cent. solution of

ferric chloride added. The colour produced is imitated by a standard

solution of carbolic acid, and a similar amount of the reagent, on

the usual principles of colorimetric analysis.

§ 237. =Carbolic Acid Powders.=--Siliceous carbolic acid powders are

placed in a retort and distilled. Towards the end the heat may be

raised to approaching redness. The distillate separates into two

portions--the one aqueous, the other consisting of the acids--and

the volume may be read off, if the distillate be received in a

graduated receiver. Carbolic acid powders, having lime as a basis,

may be distilled in the same way, after first decomposing with

sulphuric acid. The estimation of the neutral tar oils in the

distillate is easily performed by shaking the distillate with

caustic soda solution, which dissolves completely the tar acids. The

volume of the oils may be directly read off if the receiver is a

graduated tube. Allen[218] has suggested the addition of a known

volume of petroleum to the distillate, which dissolves the tar oils,

and easily separates, and thus the volume may be more accurately

determined, a correction being of course made by subtracting the

volume of petroleum first added.

[218] _Op. cit._, i. p. 310.

§ 238. =Carbolic Acid Soap.=--A convenient quantity of soap is

carefully weighed, and dissolved in a solution of caustic soda by

means of heat. A saturated solution of salt is next added,

sufficient to precipitate entirely the soap, which is filtered off;

the filtrate is acidified with hydrochloric acid, and bromine water

added. The precipitated tribromo-phenol is first melted by heat,

then allowed to cool, and the mass removed from the liquid, dried,

and weighed.

X.--Nitro-Benzene.

§ 239.--Nitro-benzene is the product resulting from the action of strong

nitric acid on benzene. Its chemical formula is C₆H₅NO₂. When pure, it

is of a pale yellow colour, of a density of 1·186, and boils at from

205° to 210°. It may be obtained in prismatic crystals by exposure to a

temperature of 3°. Its smell is exactly the same as that from the oil or

essence of bitter almonds; and it is from this circumstance, under the

name of “essence of mirbane,” much used in the preparation of perfumes

and flavouring agents.

In commerce there are three kinds of nitro-benzene--the purest, with the

characters given above; a heavier nitro-benzene, boiling at 210° to

220°; and a very heavy variety, boiling at 222° to 235° The last is

specially used for the preparation of aniline, or aniline blue.

Nitro-benzene has been used as an adulterant of bitter almond oil, but

the detection is easy (see “Foods,” p. 551). Nitro-benzene was first

discovered by Mitscherlich in 1834, and its poisonous properties were

first pointed out by Casper[219] in 1859. Its technical use in perfumes,

&c., dates from about 1848, and in the twenty-eight years intervening

between that date and 1876, Jübell[220] has collected 42 cases of

poisoning by this agent, 13 of which were fatal. One of these cases was

suicidal, the rest accidental.

[219] _Vierteljahrsschrift für ger. Med._, 1859, Bd. xvi. p. 1.

[220] _Die Vergiftungen mit Blausäure u. Nitro-benzol in forensischer

Beziehung_, Erlangen, 1876.

§ 240. =Effects of Poisoning by Nitro-benzene.=--Nitro-benzene is a very

powerful poison, whether taken in the form of vapour or as a liquid. The

action of the vapour on animals has been studied by Eulenberg[221] and

others. One experiment will serve as an illustration. Fifteen grms. of

nitro-benzene were evaporated on warm sand under a glass shade, into

which a cat was introduced. There was immediately observed in the animal

much salivation, and quickened and laboured breathing. After thirty

minutes’ exposure, on removing the shade to repeat the dose of 15 grms.,

the cat for the moment escaped. On being put back there was again

noticed the salivation and running at the eyes, with giddiness, and

repeated rising and falling. The animal at last, about one hour and

forty minutes after the first dose, succumbed with dyspnœa, and died

with progressive paralysis of the respiration. The membranes of the

brain were found gorged with blood, the lungs liver-coloured, the mucous

membrane of the trachea--to the finest sub-divisions of the

bronchia--reddened, inflamed, and clothed with a fine frothy mucus. The

left side of the heart was filled with thick black blood. The bladder

contained 8 grms. of clear urine, in which aniline was discovered. There

was a notable smell of bitter almonds.

[221] _Gewerbe Hygiene_, S. 607, Berlin, 1876.

§ 241. The effects of the vapour on man are somewhat different in their

details to those just described. In a remarkable case related by Dr.

Letheby, a man, aged 42, had spilt some nitro-benzene over his clothes.

He went about several hours breathing an atmosphere of nitro-benzene, he

then became drowsy, his expression was stupid, and his gait unsteady,

presenting all the appearances of intoxication. The stupor suddenly

deepened into coma, and the man died; the fatal course being altogether

about nine hours--viz., four hours before coma, and five hours of total

insensibility.

An interesting case of poisoning by the vapour is recorded by

Taylor.[222] A woman, aged 30, tasted a liquid used for flavouring

pastry, which was afterwards chemically identified as pure

nitro-benzene. She immediately spat it out, finding that it had an acrid

taste, and probably did not swallow more than a drop. In replacing the

bottle, however, she spilt about a tablespoonful, and allowed it to

remain for some minutes; it was a small room, and the vapour rapidly

pervaded it, and caused illness in herself as well as in a

fellow-servant. She had a strange feeling of numbness in the tongue, and

in three hours and a quarter after the accident was seen by a medical

man; she then presented all the appearances of prussic acid poisoning.

The eyes were bright and glassy, the features pale and ghastly, the lips

and nails purple, as if stained with blackberries, the skin clammy, and

the pulse feeble, but the mind was then clear. An emetic was

administered, but she suddenly became unconscious; the emetic acted, and

brought up a fluid with an odour of nitro-benzene. The stomach-pump was

also used, but the liquid obtained had scarcely any odour of

nitro-benzene. In about eleven hours consciousness returned, and in

about seventeen hours she partially recovered, but complained of flashes

of light and strange colours before her eyes. Recovery was not complete

for weeks. In this case the small quantity swallowed would probably of

itself have produced no symptoms, and the effects are to be mainly

ascribed to the breathing of the vapour.

[222] _Poisons_, Third Edition, p. 665.

§ 242. The liquid, when swallowed, acts almost precisely in the same way

as the vapour, and the symptoms resemble very much those produced by

prussic acid. The great distinction between prussic acid and

nitro-benzene poisoning is that, in the latter, there is an interval

between the taking of the poison and its effects. This is, indeed, one

of the strangest phenomena of nitro-benzene poisoning, for the person,

after taking it, may appear perfectly well for periods varying from a

quarter of an hour to two or three hours, or even longer, and then there

may be most alarming symptoms, followed by rapid death. Poisoning by

nitro-benzene satisfies the ideal of the dramatist, who requires, for

the purposes of his plot, poisons not acting at once, but with an

interval sufficiently prolonged to admit of lengthy rhapsodies and a

complicated _dénouement_. On drinking the poison there is a burning

taste in the mouth, shortly followed by a very striking blueness or

purple appearance of the lips, tongue, skin, nails, and even the

conjunctivæ. This curious colour of the skin has, in one or two

instances, been witnessed an hour before any feeling of illness

manifested itself; vomiting then comes on, the vomited matter smelling

of nitro-benzene. The skin is cold, there is great depression, and the

pulse is small and weak. The respiration is affected, the breathing

being slow and irregular, the breath smelling strongly of the liquid,

and the odour often persisting for days. A further stage is that of loss

of consciousness, and this comes on with all the suddenness of a fit of

apoplexy. The coma is also similar in appearance to apoplectic coma,

but there have frequently been seen trismus and convulsions of the

extremities. The pupils are dilated and do not react to light, and

reflex sensibility is sometimes completely extinguished. Cases vary a

little in their main features; in a few the blue skin and the deep sleep

are the only symptoms noted. Death, for the most part, occurs after a

period of from eight to twenty-four hours (occasionally as soon as four

or five hours) after taking the poison.

From the following remarkable train of symptoms in a dog, it is

probable, indeed, that nitro-benzene, taken by a human being, might

produce death, after a rather prolonged period of time, by its secondary

effects:--To a half-bred greyhound[223] were administered 15 grms. of

nitro-benzene, when shortly after there were noticed much salivation,

shivering, and muscular twitchings. The same dose was repeated at the

end of five, of seven, and of eight hours respectively, so that the dog

altogether took 60 grms., but with no other apparent symptom than the

profuse salivation. On the following day, the dog voided a tapeworm;

vomiting supervened; the heart’s action was quickened, and the breathing

difficult; convulsions followed, and the pupils were seen to be dilated.

For eight days the dog suffered from dyspnœa, quickened pulse, shivering

of the legs or of the whole body, tetanic spasms, bloody motions, great

thirst and debility. The temperature gradually sank under 25°, and the

animal finally died. The autopsy showed, as the most striking change,

the whole mucous membrane of the intestinal tract covered with a yellow

layer, which chemical analysis proved to be caused by picric acid, and

in the urine, liver, and lungs, aniline was discovered.

[223] Eulenberg, _Gewerbe Hygiene_, S. 607.

§ 243. =Fatal Dose.=--It is probable, from recorded cases, that 1 grm.

(15·4 grains) would be quite sufficient to kill an adult, and, under

favourable circumstances, less than that quantity. It would seem that

spirituous liquids especially hasten and intensify the action of

nitro-benzene, so that a drunken person, _cæteris paribus_, taking the

poison with spirits, would be more affected than taking it under other

conditions.

In a case related by Stevenson,[224] in which so small a quantity as

1·74 grm. was taken in seven doses, spread over more than forty-eight

hours; there were yet extremely alarming symptoms, and the patient seems

to have had a narrow escape. On the other hand, a woman admitted into

the General Hospital, Vienna, took 100 grms. (about 3½ ozs.) and

recovered; on admission she was in a highly cyanotic condition, with

small pulse, superficial respiration, and dribbling of urine, which

contained nitro-benzol. Artificial respiration was practised, and

camphor injections were administered. Under this treatment consciousness

was restored, and the patient recovered. On the fourth day the urine

resembled that of a case of cystitis (_Lancet_, Jan. 16, 1894). The

quantity of nitro-benzene which would be fatal, if breathed, is not

known with any accuracy.

[224] This case is not uninteresting. Through a mistake in reading an

extremely illegible prescription, M. S. S., æt. 21, was supplied by a

druggist with the following mixture;--

℞. Benzole-Nit., ʒiij.

Ol. Menth, pep., ʒss.

Ol. Olivæ, ʒx.

gutt. xxx., t. ds.

He took on sugar seven doses, each of 20 minims, equalling in all 23

min. (or by weight 27·1 grains, 1·74 grm.) of nitro-benzene--viz., three

doses on the first day, three on the second, and one on the morning of

the third day. The first two days he was observed to be looking pale and

ill, but went on with his work until the seventh dose, which he took on

the third day at 9 A.M. About 2 P.M. (or six hours after taking the

seventh dose), he fell down insensible, the body pale blue, and with all

the symptoms already described in the text, and usually seen in

nitro-benzene poisoning. With suitable treatment he recovered. The next

morning, from 8 ounces of urine some nitro-benzene was extracted by

shaking with chloroform.--Thos. Stevenson, M.D., in _Guy’s Hospital

Reports_, MS., vol. xxi., 1876.

§ 244. =Pathological Appearances.=--The more characteristic appearances

seem to be, a dark brown or even black colour of the blood, which

coagulates with difficulty (an appearance of the blood that has even

been noticed during life), venous hyperæmia of the brain and its

membranes, and general venous engorgement. In the stomach, when the

fluid has been swallowed, the mucous membrane is sometimes reddened

diffusely, and occasionally shows ecchymoses of a punctiform character.

§ 245. =The essential action of nitro-benzene= is of considerable

physiological interest. The blood is certainly in some way changed, and

gives the spectrum of acid hæmatin.[225] Filehne has found that the

blood loses, in a great degree, the power of carrying and imparting

oxygen to the tissues, and its content of carbon dioxide is also

increased. Thus, the normal amount of oxygen gas which the arterial

blood of a hound will give up is 17 per cent.; but in the case of a dog

which had been poisoned with nitro-benzene, it sank to 1 per cent.

During the dyspnœa from which the dog suffered, the carbon dioxide

exhaled was greater than the normal amount, and the arterial blood (the

natural content of which should have been 30 per cent. of this gas),

only gave up 9 per cent. Filehne seeks to explain the peculiar colour of

the skin by the condition of the blood, but the explanation is not

altogether satisfactory. Some part of the nitro-benzene, without doubt,

is reduced to aniline in the body--an assertion often made, and as often

contradicted--but it has been found in too many cases to admit of

question. It would also seem from the experiment on the dog (p. 186),

that a conversion into picric acid is not impossible. A yellow colour

of the skin and conjunctivæ, as if picric-acid-stained, has been noticed

in men suffering under slow poisoning by nitro-benzene.

[225] Filehne, W., “_Ueber die Gift-Wirkungen des Nitrobenzols_,” _Arch.

für exper. Pathol. u. Pharm._, ix. 329.

§ 246. =Detection and Separation of Nitro-Benzene from the Animal

Tissues.=--It is evident from the changes which nitro-benzene may

undergo that the expert, in any case of suspected nitro-benzene

poisoning, must specially look (1) for nitro-benzene, (2) for aniline,

and (3) for picric acid. The best general method for the separation of

nitro-benzene is to shake up the liquid (or finely-divided solid) with

light benzoline (petroleum ether), which readily dissolves

nitro-benzene. On evaporation of the petroleum ether, the nitro-benzene

is left, perhaps mixed with fatty matters. On treating with cold water,

the fats rise to the surface, and the nitro-benzene sinks to the bottom;

so that, by means of a separating funnel, the nitro-benzene may be

easily removed from animal fats. The oily drops, or fine precipitate

believed to be nitro-benzene, may be dissolved in spirit and reduced to

aniline by the use of nascent hydrogen, developed from iron filings by

hydrochloric acid, and the fluid tested with bleaching powder, or, the

aniline itself may be recovered by alkalising the fluid, and shaking up

with ether in the separation-tube (p. 156), the ether dissolves the

aniline, and leaves it, on spontaneous evaporation, as an oily yellowish

mass, which, on the addition of a few drops of sodic hypochlorite,

strikes a blue or violet-blue--with acids, a rose-red--and with bromine,

a flesh-red. It gives alkaloidal reactions with such general reagents as

platinum chloride, picric acid, &c. Aniline itself may be extracted from

the tissues and fluids of the body by petroleum ether, but in any

special search it will be better to treat the organs as in Stas’

process--that is, with strong alcohol, acidified with sulphuric acid.

After a suitable digestion in this menstruum, filter, and then, after

evaporating the alcohol, dissolve the alcoholic extract in water;

alkalise the aqueous solution, and extract the aniline by shaking it up

with light benzoline. On separating the benzoline, the aniline will be

left, and may be dissolved in feebly-acid water, and the tests before

enumerated tried.

Malpurgo[226] recommends the following test for nitro-benzene:--2 drops

of melted phenol, 3 drops of water, and a fragment of caustic potash are

boiled in a small porcelain dish, and to the boiling liquid the aqueous

solution to be tested is added. On prolonged boiling, if nitro-benzene

is present, a crimson ring is produced at the edges of the liquid; this

crimson colour, on the addition of a little bleaching powder, turns

emerald-green.

[226] _Zeit. anal. Chem._, xxxii. 235.

Oil of bitter almonds may be distinguished from nitro-benzene by the

action of manganese dioxide and sulphuric acid; bitter almond oil

treated in this way loses its odour, nitro-benzene is unaltered. To

apply the test, the liquid must be heated on the water-bath for a little

time.

XI.--Dinitro-benzol.

§ 247. =Dinitro-benzol=, C₆H₄(NO₂)₂ (ortho-, meta-, para-).--The

ortho-compound is produced by the action of nitric acid on benzol, aided

by heat in the absence of strong sulphuric acid to fix water. Some of

the para-dinitro-benzol is at the same time produced. The meta-compound

is obtained by the action of fuming nitric acid on nitro-benzol at a

boiling temperature.

The physical properties of the three dinitro-benzols are briefly as

follows:--

Ortho-d. is in the form of needles; m.p. 118°.

Meta-d. crystallises in plates; m.p. 90°.

Para-d. crystallises, like the ortho-compound, in needles, but the

melting-point is much higher, 171° to 172°.

Just as nitro-benzol by reduction yields aniline, so do the

nitro-benzols on reduction yield ortho-, meta-, or para-phenylene

diamines.

Meta-phenylene diamine is an excellent test for nitrites; and, since the

commercial varieties of dinitro-benzol either consist mainly or in part

of meta-dinitro-benzol, the toxicological detection is fairly simple,

and is based upon the conversion of the dinitro-benzol into

meta-phenylene-diamine.

Dinitro-benzol is at present largely employed in the manufacture of

explosives, such as roburite, sicherheit, and others. It has produced

much illness among the workpeople in the manufactures, and amongst

miners whose duty it has been to handle such explosives.

§ 248. =Effects of Dinitro-benzol.=--Huber[227] finds that if

dinitro-benzol is given to frogs by the mouth in doses of from 100 to

200 mgrms., death takes place in a few hours. Doses of from 2·5 to 5

mgrms. cause general dulness and ultimately complete paralysis, and

death in from one to six days.

[227] “_Beiträge zur Giftwirkung des Dinitrobenzols_,” A. Huber,

Virchow’s _Archiv_, 1891, Bd. 126, S. 240.

Rabbits are killed by doses of 400 mgrms., in time varying from

twenty-two hours to four days.

In a single experiment on a small dog, the weight of which was 5525

grms., the dog died in six hours after a dose of 600 mgrms.

It is therefore probable that a dose of 100 mgrms. per kilo would kill

most warm-blooded animals.

A transient exposure to dinitro-benzol vapours in man causes serious

symptoms; for instance, in one of Huber’s cases, a student of chemistry

had been engaged for one hour and a half only in preparing

dinitro-benzol, and soon afterwards his comrades remarked that his face

was of a deep blue colour. On admission to hospital, on the evening of

the same day, he complained of slight headache and sleeplessness; both

cheeks, the lips, the muscles of the ear, the mucous membrane of the

lips and cheeks, and even the tongue, were all of a more or less intense

blue-grey colour. The pulse was dicrotic, 124; T. 37·2°. The next

morning the pulse was slower, and by the third day the patient had

recovered.

Excellent accounts of the effects of dinitro-benzol in roburite

factories have been published by Dr. Ross[228] and Professor White,[229]

of Wigan. Mr. Simeon Snell[230] has also published some most interesting

cases of illness, cases which have been as completely investigated as

possible. As an example of the symptoms produced, one of Mr. Snell’s

cases may be here quoted.

[228] _Medical Chronicle_, 1889, 89.

[229] _Practitioner_, 1889, ii. 15.

[230] _Brit. Med. Journ._, March 3, 1894.

[Illustration: Diagram of Visual Field.]

C. F. W., aged 38, consulted Mr. Snell for his defective sight on April

9, 1892. He had been a mixer at a factory for the manufacture of

explosives. He was jaundiced, the conjunctiva yellow, and the lips blue.

He was short of breath, and after the day’s work experienced aching of

the forearms and legs and tingling of the fingers. The urine was black

in colour, of sp. gr. 1024; it was examined spectroscopically by Mr.

MacMunn, who reported the black colour as due neither to indican, nor to

blood, nor bile, but to be caused by some pigment belonging to the

aromatic series. The patient’s sight had been failing since the previous

Christmas. Vision in the right eye was 6/24, left 6/36, both optic

papillæ were somewhat pale. In each eye there was a central scotoma for

red, and contraction of the field (see diagram). The man gradually gave

up the work, and ultimately seems to have recovered. It is, however,

interesting to note that, after having left the work for some weeks, he

went back for a single day to the “mixing,” and was taken very ill,

being insensible and delirious for five hours.

§ 249. =The Blood in Nitro-benzol Poisoning.=--The effect on the blood

has been specially studied by Huber.[231] The blood of rabbits poisoned

by dinitro-benzol is of a dark chocolate colour, and the microscope

shows destruction of the red corpuscles; the amount of destruction may

be gathered from the following:--the blood corpuscles of a rabbit before

the experiment numbered 5,588,000 per cubic centimetre; a day after the

experiment 4,856,000; a day later 1,004,000; on the third day the rabbit

died.

[231] _Op. cit._

In one rabbit, although the corpuscles sank to 1,416,000, yet recovery

took place.

Dr. MacMunn[232] has examined specimens of blood from two of Mr. Snell’s

patients; he found a distinct departure from the normal; the red

corpuscles were smaller than usual, about 5 or 6 µ in diameter, and the

appearances were like those seen in pernicious anæmia. Huber, in some of

his experiments on animals, found a spectroscopic change in the blood,

viz., certain absorption bands, one in the red between C and D, and two

in the green between D and E; the action of reducing agents on this

dinitro-benzol blood, as viewed in a spectroscope provided with a scale

in which C = 48, D = 62, and E = 80·5, was as follows:--

[232] _Op. cit._

Dinitro-Bands.

In Red. In Green.

-----/\-----

50-52 62-66 70-77

After NH₄SO₄, 53-55 62-66 70-77

„ NH₃, 54-58 60-65 70-77

„ NH₄SO₄ + NH₃, 52-55 60-65 70-77

Taking the symptoms as a whole, there has been noted:--a blue colour of

the lips, not unfrequently extending over the whole face, and even the

conjunctivæ have been of a marked blue colour, giving the sufferer a

strange livid appearance. In other cases there have been jaundice, the

conjunctivæ and the skin generally being yellow, the lips blue.

Occasionally gastric symptoms are present. Sleeplessness is common, and

not unfrequently there is some want of muscular co-ordination, and the

man staggers as if drunk. In more than one case there has been noticed

sudden delirium. There is in chronic cases always more or less anæmia,

and the urine is remarkable in its colour, which ranges from a slightly

dark hue up to positive blackness. In a large proportion of cases there

is ophthalmic trouble, the characteristics of which (according to Mr.

Snell) are “failure of sight, often to a considerable degree, in a more

or less equal extent on the two sides; concentric attraction of visual

field with, in many cases, a central colour scotoma; enlargement of

retinal vessels, especially the veins; some blurring, never extensive,

of edges of disc, and a varying degree of pallor of its surface--the

condition of retinal vessels spoken of being observed in workers with

the dinitro-benzol, independently of complaints of defective sight.

Cessation of work leads to recovery.”

§ 250. =Detection of Dinitro-benzol.=--Dinitro-benzol may be detected in

urine, in blood, and in fluids generally, by the following

process:--Place tinfoil in the fluid, and add hydrochloric acid to

strong acidity, after allowing the hydrogen to be developed for at least

an hour, make the fluid alkaline by caustic soda, and extract with ether

in a separating tube; any metaphenylene-diamine will be contained in the

ether; remove the ether into a flask, and distil it off; dissolve the

residue in a little water.

Acidify a solution of sodium nitrite with dilute sulphuric acid; on

adding the solution, if it contains metaphenylene-diamine, a yellow to

red colour will be produced, from the formation of Bismarck brown

(triamido-phenol).

XII.--Hydrocyanic Acid.

§ 251. =Hydrocyanic Acid= (=hydric cyanide=)--specific gravity of liquid

0·7058 at 18° C., boiling-point 26·5° (80° F.), HCy = 27.--The anhydrous

acid is not an article of commerce, and is only met with in the

laboratory. It is a colourless, transparent liquid, and so extremely

volatile that, if a drop fall on a glass plate, a portion of it freezes.

It has a very peculiar peach-blossom odour, and is intensely poisonous.

It reddens litmus freely and transiently, dissolves red oxide of mercury

freely, forms a white precipitate of argentic cyanide when treated with

silver nitrate, and responds to the other tests described hereafter.

§ 252. =Medicinal Preparations of Prussic Acid.=--The B.P. acid is a

watery solution of prussic acid; its specific gravity should be 0·997,

and it should contain 2 per cent. of the anhydrous acid, 2 per cent. is

also the amount specified in the pharmacopœias of Switzerland and

Norway, and in that of Borussica (VI. ed.); the latter ordains, however,

a spirituous solution, and the Norwegian an addition of 1 per cent. of

concentrated sulphuric acid. The French prussic acid is ordered to be

prepared of a strength equalling 10 per cent.

The adulterations or impurities of prussic acid are hydrochloric,

sulphuric,[233] and formic acids. Traces of silver may be found in the

French acid, which is prepared from cyanide of silver. Tartaric acid is

also occasionally present. Hydrochloric acid is most readily detected by

neutralising with ammonia, and evaporating to dryness in a water-bath;

the ammonium cyanide decomposes and volatilises, leaving as a saline

residue chloride of ammonium. This may easily be identified by the

precipitate of chloride of silver, which its solution gives on testing

with silver nitrate, and the deep brown precipitate with Nessler

solution. Sulphuric acid is, of course, detected by chloride of barium;

formic acid by boiling a small quantity with a little mercuric oxide; if

present, the oxide will be reduced, and metallic mercury fall as a grey

precipitate. Silver, tartaric acid, and any other fixed impurities are

detected by evaporating the acid to dryness, and examining any residue

which may be left. It may be well to give the various strengths of the

acids of commerce in a tabular form:--

[233] A trace of sulphuric or hydrochloric acid should not be called an

_adulteration_, for it greatly assists the preservation, and therefore

makes the acid of greater therapeutic efficiency.

Per cent.

British Pharmacopœia, Switzerland, and Bor. (vj), 2

France, 10

Vauquelin’s Acid, 3·3

Scheele’s „ 4 to 5[234]

Riner’s „ 10

Robiquet’s „ 50

Schraeder’s „ 1·5

Duflos’ „ 9

Pfaff’s „ 10

Koller’s „ 25

[234] Strength very uncertain.

In English commerce, the analyst will scarcely meet with any acid

stronger than Scheele’s 5 per cent.

Impure oil of bitter almonds contains hydric cyanide in variable

quantity, from 5 per cent. up to 14 per cent. There is an officinal

preparation obtained by digesting cherry-laurel leaves in water, and

then distilling a certain portion over. This _Aqua Lauro-cerasi_ belongs

to the old school of pharmacy, and is of uncertain strength, but varies

from ·7 to 1 per cent. of HCN.

§ 253. =Poisoning by Prussic Acid.=--Irrespective of suicidal or

criminal poisoning, accidents from prussic acid may occur--

1. From the use of the cyanides in the arts.

2. From the somewhat extensive distribution of the acid, or rather of

prussic-acid producing substances in the vegetable kingdom.

1. =In the Arts.=--The galvanic silvering[235] and gilding of metals,

photography, the colouring of black silks, the manufacture of Berlin

blue, the dyeing of woollen cloth, and in a few other manufacturing

processes, the alkaline cyanides are used, and not unfrequently fumes of

prussic acid developed.

[235] The preparation used for the silvering of copper vessels is a

solution of cyanide of silver in potassic cyanide, to which is added

finely powdered chalk. Manipulations with this fluid easily develop

hydrocyanic acid fumes, which, in one case related by Martin (_Aerztl.

Intelligenzbl._, p. 135, 1872), were powerful enough to produce symptoms

of poisoning.

2. =In the Animal Kingdom.=--One of the myriapods (_Chilognathen_)

contains glands at the roots of the hairs, which secrete prussic acid;

when the insect is seized, the poisonous secretion is poured out from

the so-called _foramina repugnatoria_.

3. =In the Vegetable Kingdom.=--A few plants contain cyanides, and many

contain amygdalin, or bodies formed on the type of amygdalin. In the

presence of emulsin (or similar principles) and water, this breaks up

into prussic acid and other compounds--an interesting reaction usually

represented thus--

C₂₀H₂₇NO₁₁ + 2H₂O = CNH + C₇H₆O + 2C₆H₁₂O₆.

1 equivalent of amygdalin--_i.e._, 457 parts--yielding 1 equivalent of

CNH or 27 parts; in other words, 100 parts of amygdalin yield

theoretically 5·909 parts of prussic acid,[236] so that, the amount of

either being known, the other can be calculated from it.

[236] According to Liebig and Wöhler, 17 grms. of amygdalin yield 1 of

prussic acid (_i.e._, 5·7 per cent.) and 8 of oil of bitter almonds.

Thirty-four parts of amygdalin, mixed with 66 of emulsin of almonds,

give a fluid equalling the strength of acid of most pharmacopœias, viz.,

2 per cent.

Greshoff[237] has discovered an amygdalin-like glucoside in the two

tropical trees _Pygeum parriflorum_ and _P. latifolium_. The same author

states that the leaves of _Gymnema latifolium_, one of the Asclepiads,

yields to distillation benzaldehyde hydrocyanide. Both _Lasia_ and

_Cyrtosperma_, plants belonging to the natural family of the Orontads,

contain in their flowers potassic cyanide. _Pangium edule_, according to

Greshoff, contains so much potassic cyanide that he was able to prepare

a considerable quantity of that salt from one sample of the plant. An

Indian plant (_Hydnocarpus inebrians_) also contains a cyanide, and has

been used for the purpose of destroying fish. Among the Tiliads,

Greshoff found that _Echinocarpus Sigun_ yielded hydrocyanic acid on

distillation. Even the common linseed contains a glucoside which breaks

up into sugar, prussic acid, and a ketone.

[237] M. Greshoff--_Erster Bericht über die Untersuchung von

Pflanzenstoffen Niederländisch-Indiens. Mittheilungen aus dem

chemisch-pharmakologischen Laboratorium des botan. Gartens des Staates_,

vii., Batavia, 1890, Niederländisch. Dr. Greshoff’s research indicates

that there are several other cyanide-yielding plants than those

mentioned in the text.

The following plants, with many others, all yield, by appropriate

treatment, more or less prussic acid:--Bitter almonds (_Amygdalus

communis_); the _Amygdalus persica_; the cherry laurel (_Prunus

laurocerasus_); the kernels of the plum (_Prunus domestica_); the bark,

leaves, flowers, and fruit of the wild service-tree (_Prunus padus_);

the kernels of the common cherry and the apple; the leaves of the

_Prunus capricida_; the bark of the _Pr. virginiana_; the flowers and

kernels of the _Pr. spinosa_; the leaves of the _Cerasus acida_; the

bark and almost all parts of the _Sorbus aucuparia_, _S. hybrida_, and

_S. torminalis_; the young twigs of the _Cratægus oxyacantha_; the

leaves and partly also the flowers of the shrubby _Spiræaceæ_, such as

_Spiræa aruncus_, _S. sorbifolia_, and _S. japonica_;[238] together with

the roots of the bitter and sweet _Cassava_.

[238] The bark and green parts of the _Prunus avium_, L., _Prunus

mahaleb_, L., and herbaceous _Spirææ_ yield no prussic acid.

In only a few of these, however, has the exact amount of either prussic

acid or amygdalin been determined; 1 grm. of bitter almond pulp is about

equal to 2½ mgrms. of anhydrous prussic acid. The kernels from the

stones of the cherry, according to Geiseler, yield 3 per cent. of

amygdalin; therefore, 1 grm. equals 1·7 mgrm. of HCN.

§ 254. The wild service-tree (_Prunus padus_) and the cherry-laurel

(_Prunus Laurocerasus_) contain, not amygdalin but a compound of

amygdalin with amygdalic acid; to this has been given the name of

laurocerasin. It was formerly known as amorphous amygdalin; its formula

is C₄₀H₅₅NO₂₄; 933 parts are equivalent to 27 of hydric cyanide--that

is, 100 parts equal to 2·89.

In the bark of the service-tree, Lehmann found ·7 per cent. of

laurocerasin (= ·02 HCN), and in the leaves of the cherry-laurel 1·38

per cent. (= 0·39 HCN).

Francis,[239] in a research on the prussic acid in cassava root, gives

as the mean in the sweet cassava ·0168 per cent., in the bitter ·0275

per cent., the maximum in each being respectively ·0238 per cent., and

·0442 per cent. The bitter-fresh cassava root has long been known as a

very dangerous poison; but the sweet has hitherto been considered

harmless, although it is evident that it also contains a considerable

quantity of prussic acid.

[239] “On Prussic Acid from Cassava,” _Analyst_, April 1877, p. 5.

The kernels of the peach contain about 2·85 per cent. amygdalin (= ·17

HCN); those of the plum ·96 per cent. (= ·056 HCN); and apple pips ·6

per cent. (= ·035 per cent. HCN).

It is of great practical value to know, even approximately, the quantity

of prussic acid contained in various fruits, since it has been adopted

as a defence in criminal cases that the deceased was poisoned by prussic

acid developed in substances eaten.

§ 255. =Statistics.=--Poisoning by the cyanides (prussic acid or

cyanide of potassium) occupies the third place among poisons in order

of frequency in this country, and accounts for about 40 deaths annually.

In the ten years ending 1892 there were recorded no less than 395 cases

of accidental, suicidal, or homicidal poisoning by prussic acid and

potassic cyanide. The further statistical details may be gathered from

the following tables:--

DEATHS IN ENGLAND AND WALES DURING THE TEN YEARS 1883-1892 FROM PRUSSIC

ACID AND POTASSIC CYANIDE.

PRUSSIC ACID (ACCIDENT OR NEGLIGENCE).

Ages, 0-1 1-5 5-15 15-25 25-65 65 and Total

above

Males, ... 1 1 1 12 1 16

Females, 1 1 ... 2 7 ... 11

--------------------------------------------

Totals, 1 2 1 3 19 1 27

--------------------------------------------

CYANIDE OF POTASSIUM (ACCIDENT OR NEGLIGENCE).

Ages, 1-5 5-15 15-25 25-65 65 and Total

above

Males, 1 1 4 1 ... 7

Females, 1 ... ... 3 ... 4

---------------------------------------

Totals, 2 1 4 4 ... 11

---------------------------------------

PRUSSIC ACID (SUICIDE).

Ages, 15-25 25-65 65 and Total

above

Males, 23 156 23 202

Females, 5 13 1 19

----------------------------

Totals, 28 169 24 221

----------------------------

POTASSIUM CYANIDE (SUICIDE).

Ages, 5-15 15-25 25-65 65 and Total

above

Males, 1 6 88 5 100

Females, ... 6 15 1 22

----------------------------------

Totals, 1 12 103 6 122

----------------------------------

To these figures must be added 10 cases of murder (2 males and 8

females) by prussic acid, and 4 cases of murder (3 males and 1 female)

by potassic cyanide.

In order to ascertain the proportion in which the various forms of

commercial cyanides cause death, and also the proportion of accidental,

suicidal, and criminal deaths from the same cause, Falck collated twelve

years of statistics from medical literature with the following result:--

In 51 cases of cyanide poisoning, 29 were caused by potassic cyanide, 9

by hydric cyanide, 5 by oil of bitter almonds, 3 by peach stones (these

3 were children, and are classed as “domestic,” that is, taking the

kernels as a food), 3 by bitter almonds (1 of the 3 suicidal and

followed by death, the other 2 “domestic”), 1 by tartaric acid and

potassic cyanide (a suicidal case, an apothecary), and 1 by

ferro-cyanide of potassium and tartaric acid. Of the 43 cases first

mentioned, 21 were suicidal, 7 criminal, 8 domestic, and 7 medicinal;

the 43 patients were 24 men, 14 children, and 5 women.

The cyanides are very rarely used for the purpose of murder: a poison

which has a strong smell and a perceptible taste, and which also kills

with a rapidity only equalled by deadly bullet or knife-wounds, betrays

its presence with too many circumstances of a tragic character to find

favour in the dark and secret schemes of those who desire to take life

by poison. In 793 poisoning cases of a criminal character in France, 4

only were by the cyanides.

Hydric and potassic cyanides were once the favourite means of

self-destruction employed by suicidal photographers, chemists,

scientific medical men, and others in positions where such means are

always at hand; but, of late years, the popular knowledge of poisons has

increased, and self-poisoning by the cyanides scarcely belongs to a

particular class. A fair proportion of the deaths are also due to

accident or unfortunate mistakes, and a still smaller number to the

immoderate or improper use of cyanide-containing vegetable products.

§ 256. =Accidental and Criminal Poisoning by Prussic Acid.=--The poison

is almost always taken by the mouth into the stomach, but occasionally

in other ways--such, for example, as in the case of the illustrious

chemist, Scheele, who died from inhalation of the vapour of the acid

which he himself discovered, owing to the breaking of a flask. There is

also the case related by Tardieu, in which cyanide of potassium was

introduced under the nails; and that mentioned by Carrière,[240] in

which a woman gave herself, with suicidal intent, an enema containing

cyanide of potassium. It has been shown by experiments, in which every

care was taken to render it impossible for the fumes to be inhaled, that

hydrocyanic acid applied to the eye of warm-blooded animals may destroy

life in a few minutes.[241]

[240] “_Empoisonnement par le cyanure de potassium,--guérison_,”

_Bullet. général de Thérap._, 1869, No. 30.

[241] N. Gréhant, _Compt. rend. Soc. Biol._ [9], xi. 64, 65.

With regard to errors in dispensing, the most tragic case on record is

that related by Arnold:[242]--A pharmaceutist had put in a mixture for a

child potassic cyanide instead of potassic chlorate, and the child died

after the first dose: the chemist, however, convinced that he had made

no mistake, to show the harmlessness of the preparation, drank some of

it, and there and then died; while Dr. Arnold himself, incautiously

tasting the draught, fell insensible, and was unconscious for six hours.

[242] Arnold, A. B., “Case of Poisoning by the Cyanide of Potassium,”

_Amer. Journ. of Med. Scien._, 1869.

§ 257. =Fatal Dose.=--Notwithstanding the great number of persons who in

every civilised country fall victims to the cyanides, it is yet somewhat

doubtful what is the minimum dose likely to kill an adult healthy man.

The explanation of this uncertainty is to be sought mainly in the

varying strength of commercial prussic acid, which varies from 1·5

(Schraeder’s) to 50 per cent. (Robiquet’s), and also in the varying

condition of the person taking the poison, more especially whether the

stomach be full or empty. In by far the greater number, the dose taken

has been much beyond that necessary to produce death, but this

observation is true of most poisonings.

The dictum of Taylor, that a quantity of commercial prussic acid,

equivalent to 1 English grain (65 mgrm.) of the anhydrous acid, would,

under ordinary circumstances, be sufficient to destroy adult life, has

been generally accepted by all toxicologists. The minimum lethal dose of

potassic cyanide is similarly put at 2·41 grains (·157 grm.). As to

bitter almonds, if it be considered that as a mean they contain 2·5 per

cent. of amygdalin, then it would take 45 grms., or about 80 almonds, to

produce a lethal dose for an adult; with children less--in fact, 4 to 6

bitter almonds are said to have produced poisoning in a child.

§ 258. =Action of Hydric and Potassic Cyanides on Living

Organisms.=--Both hydric cyanide and potassic cyanide are poisonous to

all living forms, vegetable or animal, with the exception of certain

fungi. The cold-blooded animals take a larger relative dose than the

warm-blooded, and the mammalia are somewhat more sensitive to the

poisonous action of the cyanides than birds; but all are destroyed in a

very similar manner, and without any essential difference of action. The

symptoms produced by hydric and potassic cyanide are identical, and, as

regards general symptoms, what is true as to the one is also true as to

the other. There is, however, one important difference in the action of

these two substances, if the mere local action is considered, for

potassic cyanide is very alkaline, possessing even caustic properties. I

have seen, _e.g._, the gastric mucous membrane of a woman, who had taken

an excessive dose of potassic cyanide on an empty stomach, so inflamed

and swollen, that its state was similar to that induced by a moderate

quantity of solution of potash. On the other hand, the acid properties

of hydric cyanide are very feeble, and its effect on mucous membranes or

the skin in no way resembles that of the mineral acids.

It attacks the animal system in two ways: the one, a profound

interference with the ordinary metabolic changes; the other, a paralysis

of the nervous centres. Schönbein discovered that it affected the blood

corpuscles in a peculiar way; normal blood decomposes with great ease

hydrogen peroxide into oxygen and water. If to normal venous blood a

little peroxide of hydrogen be added, the blood at once becomes bright

red; but if a trace of prussic acid be present, it is of a dark brown

colour. The blood corpuscles, therefore, lose their power of conveying

oxygen to all parts of the system, and the phenomena of asphyxia are

produced. Geppert[243] has proved that this is really the case by

showing, in a series of researches, that, under the action of hydric

cyanide, less oxygen is taken up, and less carbon dioxide formed than

normal, even if the percentage of oxygen in the atmosphere breathed is

artificially increased. The deficiency of oxygen is in part due to the

fact that substances like lactic acid, the products of incomplete

combustion, are formed instead of CO₂.

Poisons, Their Effects and Detection A Manual for the Use of Analytical Chemists and Experts · 第 7 / 23 章

Chloral (or chloroform), when boiled with resorcinol and the liquid made