THE TAR ACIDS. 
§§ 217-221.] 
177 
six weeks in a caoutchouc factory, suffered from mental weakness 
and digestive troubles ; there were anaesthesia 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 antesthesia 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. 
§ 217. Post-mortem Appearances. —The pathological appearances 
found after sudden death from disulphide of carbon are but little different 
from those found after fatal chloroform breathing. 
§ 218. 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 C0 2 . 
Carbon disulphide is best identified by (1) Hofman’s test, viz. passing 
the vapour into an ethereal solution of triethyl-phosphin, (C 2 H 5 ) 3 P. 
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(C 2 H 5 ) 3 CS 2 . 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) CS 2 gives, with an alcoholic 
solution of potash, a precipitate of potassic xanthate, CS 2 C 2 H 5 OK. 
§ 219. Xanthogenic acid or ethyloxide-sulphocarbonate (CS 2 C 2 H 5 OH) is pre¬ 
pared 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 anaesthetic action similar to bisulphide of carbon. Its properties are probably 
due to CS 2 being liberated within the body. 
§ 220. Potassic xanthogenate (CS 2 C 2 H 5 OK) and potassic xanthamylate 
(CS 2 C 5 H 11 OK) (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 CS 2 , and 
are poisonous, inducing symptoms very similar to those already detailed. Reid Hunt 
states that the fatal dose of pot. xanthogenate for rodents (mice) lies between 0-4 and 
0-5 grm. per kilo, of body weight; in non-fatal doses it is antagonistic to nitrates. 
IX.—The Tar Acids—Phenol—Cresol. 
§ 221. Carbolic Acid. Syn. Phenol, Phenol Alcohol, Phenylic 
Hydrate ; Phenic Acid ; Coal-Tar Creasote. —The formula for carbolic 
acid is C 6 H 5 HO. The pure substance appears at the ordinary tempera¬ 
ture as a colourless solid, crystallising in long prisms ; the fusibility of the 
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