POISONS AND POISONING. 



By V. T. Atkinson, V. S. 

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



DEFINITION OF A POISON. 



To define clearly the meaning of the word " poison " would be 

 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 unorganized substances, inor- 

 ganic 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 con- 

 ception 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 insij 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 ex'posure of poisons used for Twrticulturcd, 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) DaTMLged 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 pJants in the pasture or forage. 



(5) The bite or sting of a poisonous insect or the bite of an anim/il. 



(6) Malicious poisoning. 



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