THE TAR ACIDS. 
§ 235 -] 
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 (1799 40 ), there is preserved the stomach of a child 
who died from taking carbolic acid accidentally. It looks like a piece 
of paper, and is very white, with fawn-coloured spots ; the rugae are 
absent, and the mucous membrane seems to have entirely vanished. 
Not infrequently the stomach exhibits white spots with roundish edges. 
The duodenum and upper part of the small intestine are often affected 
(see a preparation in St Bartholomew’s museum, 1949, e), and the action 
is not always limited to the first part of the intestine. 
The respiratory passages are often inflamed, and the lungs in¬ 
filtrated 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 exhibit precisely the characters just detailed. Putrefaction 
is retarded according to the dose, and there is often a smell of carbolic 
acid. 1 If any urine is contained in the bladder, it will probably be 
dark, and present the characters of carbolic urine, detailed at p. 186. 
Tests for Carbolic Acid. 
§ 235. 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 pre¬ 
caution 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, 
1 In order to detect this odour, it is well to open the head first, lest the putre¬ 
faction of the internal viscera be so great as to mask the odour. 
