POISONS. 197 



irritant effects^ and also with ill consequences result- 

 ing from sloughing of the corroded tissues, the prin- 

 cipal being actual loss of useful substance, perforations, 

 and strictures. Thus, corrosives are much more formid- 

 able than simple irritants. This obtains with the sym- 

 ptoms as well as with the effects. Enormous doses 

 generally cause immediate collapse. 



Corrosive Sublimate is the best representative of this 

 class. It is administered maliciously or by mistake for 

 calomel. It causes acute gastro- enteritis and death when 

 given in doses of two drachms. It causes an exhausting 

 cough in ruminants (Gamgee). Albuminous materials are 

 the best antidotes. Copper, zinc, silver, and iron salts 

 are corrosive poisons. When given in large enough doses 

 concentrated alkaline solutions especially disorganise the 

 epithelial layers of the membrane with which they come in 

 contact. Mineral acids act as corrosives, nitric turns the 

 parts with which it comes in contact yellow, sulphuric, 

 renders them black, and hydrochloric white. Dilute alkaline 

 solutions and demulcents should be given in these cases. 



Eliminative Poisons enter the blood and are removed 

 thence by the excretory organs, which they over-irritate in 

 the act of passage, and so inflame. Thus, the symptoms 

 vary much with each agent, and we have more time for 

 treatment. The poison, once it enters the blood, is singu- 

 larly inaccessible. 



Aloes, castor-oil beans, euphorbium, and gamboge act 

 in this way on the intestines. 



Ai^senic is obtained by malicious administration, over- 

 dose, or accidental presence in cakes and other articles of 

 food. It is eliminated by the stomachic and intestinal 

 glands, of which it causes very extensive inflammation. 

 The hydrated peroxide of iron is recommended as an 

 antidote. The tests are numerous and very definite. 



Antimony, besides its influence on numerous glands of 

 the body, is a sedative. ^ 



Calomel affects especially the salivary glands and liver. 

 It must be opposed by albumen and astringents. 



Nitrate of Potash may be detected in the urine by the 



