§ 76. Post-mortem Appearances.—The pathological appearances are very similar to those found in the case already detailed; though the skin of the face may not be eroded in any way by the acid, yet the more delicate mucous membrane of the mouth, gullet, &c., appears mostly to be changed, and is usually white or whitish-brown. There is, however, in the museum of the Royal College of Surgeons the stomach and gullet (No. 2386c.) of an infant thirteen months old; the infant drank a tea-cupful of strong hydrochloric acid, and died nine hours after the dose. The pharynx and the upper end of the gullet is quite normal, the corrosive action commencing at the lower end, so that, although the acid was concentrated, not the slightest effect was produced on the delicate mucous membrane of the throat and upper part of the gullet. The lower end of the gullet and the whole of the stomach were intensely congested; the rugæ of the latter were ecchymosed and blackened by the action of the acid. There were also small hæmorrhages in the lungs, which were ascribed to the action of the acid on the blood. Perforation of the stomach has not been noticed in hydrochloric acid poisoning.
In Guy’s Hospital museum (prep. 179910), the stomach and duodenum of the case mentioned exhibit the mucous membrane considerably injected, with extravasations of blood, which, at the time when the preparation was first arranged, were of various hues, but are now somewhat altered, through long keeping in spirit. In St. George’s Hospital museum (ser. x. 43, d. 200) are preserved the stomach and part of the duodenum of a person who died from hydrochloric acid. The case is detailed in the Medical Times and Gazette for 1853, vol. ii. p. 513. The whole inner surface appears to be in a sloughing state, and the larynx and lung were also inflamed.
A preparation, presented by Mr. Bowman to King’s College Hospital museum, exhibits the effects of a very large dose of hydrochloric acid. The gullet has a shrivelled and worm-eaten appearance; the stomach is injected with black blood, and was filled with an acid, grumous matter.[97]
[97] A drawing of parts of the gullet and stomach is given in Guy and Ferrier’s Forensic Medicine.
Looking at these and other museum preparations illustrating the effects of sulphuric and hydrochloric acids, I was unable (in default of the history of the cases) to distinguish between the two, by the naked eye appearances, save in those cases in which the disorganisation was so excessive as to render hydrochloric acid improbable. On the other hand, the changes produced by nitric acid are so distinctive, that it is impossible to mistake its action for that of any other acid. The nitric acid pathological preparations may be picked out at a glance.
Detection and Estimation of Free Hydrochloric Acid.
§ 77. (1) Detection.—A large number of colouring reagents have been proposed as tests for the presence of free mineral acid; among the best is methyl-aniline violet decolorised by a large amount of hydrochloric acid; the violet turns to green with a moderate quantity, and to blue with a small quantity.