THE LESIONS INDUCED BY POISONS. 351 



The Lesions Induced by Exogenous Poisons. 1 



Sulphuric Acid. 



The effects of this poison vary with the amount taken and with its strength. Death 

 usually occurs in from two to twenty-four hours after the ingestion of the concen- 

 trated acid. A case of death within an hour is recorded. When the poison is less con- 

 centrated or its effects are less intense, the patient may survive for months. 



The skin of the face about the mouth may be blackened and charred by the acid. 



The mouth and pharynx are of a grayish or blackish color, or are covered with a 

 whitish layer, while the deeper tissues are reddened. Sometimes these regions escape 

 the action of the poison. 



The larynx, trachea, and lungs are sometimes softened and blackened by the acci- 

 dental passage of the acid into them. This may take place even when the acid does 

 not pass into the oesophagus. 



The (esophagus seldom escapes. It is colored grayish or blackish, softened, and the 

 mucous membrane comes off in shreds. If life is prolonged, cicatrices and strictures 

 are formed. The stomach may contain a blackish, pulpy fluid, due to the action of the 

 acid on mucus, blood, etc. It is coated on its internal surface with a black, sticky 

 layer, beneath which the mucous membrane is reddened. The mucous membrane may 

 be blackened in patches or stripes. The organ may be contracted and the mucous 

 membrane corrugated. Sometimes perforation takes place and the acid blackens and 

 softens the adjoining viscera. In protracted cases cicatrices are formed and the organ 

 is contracted. If the poison is dilute there may be only the lesions of chronic gastritis. 



The blood is sometimes thickened, syrupy, acid, and may form thrombi in the vessels. 



Fatty degeneration of the renal epithelium is mentioned by some authors. 



The body may be partially preserved from decomposition, owing to the action of 

 the acid upon the tissues. 



The solution of indigo in sulphuric acid, commonly known as sulphate of indigo, 

 produces the same lesions as sulphuric acid, and also stains the tissues with which it 

 comes in contact of a dark-blue color. It is stated that an indigo-blue tint is often 

 found in the mucous membranes after poisoning by pure sulphuric acid. 



Nitric Acid. 



Death may occur very soon after the taking of the poison, but is not usual until 

 the lapse of several hours, and may not ensue for several days or weeks. 



The surface of the mucous membrane of the mouth, pharynx, and oesophagus is cov- 

 ered with yellow eschars wherever the acid has touched it. Beneath and around the 

 eschars the tissues are congested and red. The poison may reach the oesophagus 

 without acting on the mouth. The stomach contains a viscous, sanguinolent, yellow 

 or greenish fluid. The mucous membrane is congested, red, swollen, softened, and 

 ecchymotic. It is rarely perforated. The duodenum may be inflamed, and the inflam- 

 mation extend to its peritoneal coat. The rest of the intestines usually escapes the 

 action of the acid. 



The larynx is very frequently acted on by the acid. There are yellow eschars, 

 congestion and swelling of the mucous membrane, sometimes cedema of the glottis. 

 The trachea may be inflamed and the lungs congested. 



If the patient survive the first effects of the poison, chronic inflammation, cicatriza- 

 tion, and contraction may occur. 



The acid nitrate of mercury, if taken in a concentrated form into the stomach, may 

 induce the same lesions as nitric acid. 



1 For special precautions to be taken in the post-mortem examination in cases of 

 suspected poisoning, see p. 38. 



