72 AKTIFICIAL INSANITY. 



2. In the gaseous state 



Carbonic acid. 



Laughing gas (nitrous oxide). 



Sulphuretted hydrogen (privy gas). 



Chloroform- vapour. 



Sulphurous acid. 



Tobacco fumes. 



The effects produced by these or other poisons, including 

 temporary or permanent stupor or stupidity, necessarily vary 

 with 



1. The nature of the drug or poison used. 



2. Its dose, and the repetition, continuance, or intermit- 

 tence of administration. 



3. Its varying composition and freshness. 



4. The diverse constitution of the animal operated on, 

 including its idiosyncrasy (if any), as well as its genus and 

 species. 



Probably the most common form of toxic insanity now-a- 

 days artificially produced is alcoholic intoxication. But the 

 effects of alcoholic and other intoxicants on the lower animals 

 are specially discussed in a separate chapter. 



In bygone days toxic mania was produced for nefarious 

 purposes, to aid the aims of the thief. At certain fairs in 

 Normandy, we are told by Pierquin, it used to be the custom 

 for horse thieves, by diffusing cantharides or euphorbium in 

 the air, to produce in horses an epizootic panic. This led to 

 a confusion among the owners of the horses and the attenders 

 of the fair a state of matters highly favourable to the objects 

 of the ingenious but unscrupulous experimentalists. The 

 substances here used would appear to have acted as irritants 

 on the nostrils of the horses, and to have produced effects 

 resembling those caused, for instance, by the bot or gadfly. 

 The animals became indocile, restive, unmanageable ; broke 

 from their tethers or guardians and stampeded. And what 

 is of importance to be borne in mind by all concerned in the 

 custody of domestic animals, furiosity in the runaway horses 

 was developed in proportion to the kind and amount of man's 

 attempted interference with their freedom of movement. In 

 other words, man's best policy would have been, or was, to 



