POISONS AND POISONING. 



By V. T. Atkinson, V. S. 

 [Revised by C. Dwight Marsh, Ph. D.] 

 DEFINITION OF A POISON, 



To define clearly the meaning of the word " poison " is somewhat 

 difficult. Even in law the word has never been defined, and when a 

 definition is attempted we are apt to include either too much or too 

 little. The following definition given by Husemann is perhaps the 

 best : " Poisons are those substances, inorganic or organic, existing 

 in the organism or introduced from the outside, produced artificially 

 or formed as natural products, which, through their chemical nature, 

 under definite conditions, so affect some organ of a living organism 

 that the health or well-being of the organism is temporarily or 

 chronically injured." The common conception of a poison is any 

 substance which, in small quantity, will destroy life, except such as 

 act by purely mechanical means, as, for example, powdered glass. 



Some substances that are not usually looked upon as poisons may 

 destroy life if given in large doses, such as common salt. Other sub- 

 stances which are perfectly harmless when taken into the body in 

 the usual way are poisons if injected into the circulation, such as 

 distilled water, milk, or glycerin. Living organisms are not " chem- 

 ical substances," and are not considered in this connection. 



SOURCES OF POISONING. 



Poisoning may come from many causes, among the chief of which 

 are the following : 



(1) Errors in medication. — By using the wrong substance or too 

 large dose an animal may be poisoned, 



(2) The exposure of poisons used for horticultural., technical., or 

 other legitimate purposes. — Poisons used for spraying plants, disin- 

 fecting, poisoning vermin, dipping cattle or sheep, painting, smelt- 

 ing, dyeing, or other purposes may be so handled as to come within 

 the reach of animals. 



(3) Damaged food. — Food that has undergone putrefaction or cer- 

 tain kinds of fermentation or heating, may have become poisonous, 

 producing forage poisoning, meat poisoning, cheese poisoning, etc. 



(4) Poisonous plants in the pastu7'e or forage. 



(5) The hite or sting of a poisonous insect or the hite of an animal. 



(6) Malicious poisoning. 



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