4 VETERINAEY TOXICOLOGY 



(snake venoms), though originated by the living cell, and 

 giving rise to anti-bodies, like the toxines of infective 

 diseases, are not of bacterial origin, and are thus classed as 

 poisons. 



In practice, by common consent, certain inorganic and 

 organic compounds, and certain pl|ints and plant products, 

 irrespective of any possible therapeutic action, or dietetic 

 value, are held to be poisonous. In most, but unfortunately 

 by no means all, cases of plants, the essential cause or 

 active principle has been separated in a more or less pure 

 form, capable of recognition. 



GENERAL CHEMISTRY OF POISONS. 



An attempt may be made to give an outline of the 

 various classes of substances falling under the above 

 heading, and responsible for poisoning. But it must 

 clearly be understood that such an outline can have no 

 pretensions to completeness. 



1. Inorganic of Mineral Poisons. 



(a) Certain elements — e.g., phosphorus, sulphur. 

 (6) Simple gases — e.g., carbon monoxide, oxides of 

 nitrogen, ammonia, sulphuretted hydrogen. 



(c) Acids and alkalis. 



(d) Metalloids, or elements, which chemically form the 

 border line between non-metal and metal — e.g., arsenic and. 

 antimony compounds. 



(e) Metals and their salts — e.g., lead, mercury, copper, 

 barium, zinc, chromium, iron, etc. 



2. Opg-anic Poisons. By organic is understood any 

 compound, necessarily containing carbon, other than the 

 oxides of carbon and the carbonates, often of animal or 

 vegetable origin, but often synthetical— i.e., capable of 

 being made from its elements. Apart from artificial 

 drugs this great division includes the active principles of 

 poisonous plants. 



(a) Alkaloids, distinguished by being bases — i.e., forming 



