352 THE LESIONS INDUCED >BY POISONS. 



Hydrochloric Acid. 



In fatal cases death occurs on the average in about twenty-four hours. The lesions 

 are in general similar to those produced by sulphuric and nitric acids, except that the 

 eschars are usually of a whitish color at first, becoming, after a time, discolored and 

 disintegrated. It is also more common to find false membranes on the inflamed surfaces. 



Oxalic Acid. 



In fatal cases death may occur within ten minutes (in one case it occurred in three 

 minutes) or it may be delayed for two or three weeks. The period of death does not 

 depend, as do in general the symptoms, upon the amount and concentration of the 

 poison. 



The mucous membrane of the mouth, pharynx, and ossopMgus is usually white and 

 shrivelled, and easily peeled off, and may be covered with brownish vomit from the 

 stomach. The oesophagus may be much contracted. The stomach is usually contracted 

 and contains a dark-brown, acid, mucous fluid. The mucous membrane of the stomach 

 may be pale, soft, and easily detached, sometimes looking as if it had been boiled in 

 water. Sometimes it is red and congested; sometimes blackened and gangrenous; 

 sometimes peeled off in patches. Perforation is of rare occurrence. If life be pro- 

 longed the whitened condition of the mucous membrane is succeeded by congestion and 

 inflammation. The small intestines may be inflamed. Inflammation of the pleura and 

 peritoneum, and congestion of the lungs, are of occasional occurrence. In some cases of 

 death from oxalic acid there are no well-marked lesions. 



Potassium oxalate produces the same lesions as oxalic acid. 



Tartaric Acid. 



This acid is seldom used as a poison, but in large doses may prove fatal. The 

 lesions in the cases observed were redness and inflammation of the mucous membrane 

 of the gastro-intestinal canal. 



Potash, Soda, and their Carbonates. 



These substances are not commonly used as poisons with suicidal or homicidal in- 

 tent, but may be taken by mistake. They may cause death in a few hours, or life may 

 be prolonged for several weeks. 



The mucous membrane of the mouth, pharynx, (esophagus, and stomach is softened, 

 swollen, congested, and inflamed, or may be peeled off. It may be blackened from local 

 changes in the blood. The mucous membrane of the larynx and trachea, may alsc be 

 swollen and inflamed. 



If life is prolonged for some time, cicatrices and strictures of the oesophagus and 

 stomach are apt to be produced as a result of the reparative inflammation. 



Ammonia. 



The vapor of strong ammonia may cause death from inflammation of the larynx 

 and air passages. The strong solution of ammonia produces lesions similar to those of 

 potash and soda. The larynx, trachea, and bronchi are frequently inflamed, and may 

 be covered with false membranes. Fatal inflammation of the rectum and colon has 

 been produced by an enema of strong solution of ammonia. 



Potassium Nitrate. 



Accidental poisoning sometimes occurs from large doses of this salt. In the ob 

 served cases there were intense congestion and inflammation of the stomach and intes 

 tines, and in one case a small perforation of the stomach existed. 



