452. History of Animal Plagues. 



^We cannot, then, hope for any good from remedies. For 

 more than two thousand years, an infinite number of the most 

 learned men hav^e given their most constant attention to observ^- 

 ing the eifects of medicines on mankind. We know well enough 

 the value of simples, the properties which they have of stimulat- 

 ing or evacuating, and their dose. But we have not nearly the 

 same knowledge to guide us when we deal with animals : few 

 talented persons have observed their diseases ; the art of curing 

 them has been left to men of low condition, who have no know- 

 ledge of the anatomy of the lower creatures, and who have not 

 informed themselves by the study of nature, or of good authors. 

 The cattle-doctors invariably follow the same routine traced by 

 the ancient veterinarians, and their science consists of divers 

 receipts, which they have found amongst the papers of their pre- 

 decessors. 



^The structure of the stomach of cattle is very different from 

 that of man; in general the envelopes of their nerves are much 

 more thick, the sensations less active, the pulse less frequent, the 

 arteries more hard, and the heart less irritable. All these pe- 

 culiarities change the effect of remedies in animals, in a way 

 quite different to man; and it is only within a few years that 

 convincing proof has been afforded of the difference between the 

 effect which a remedy has on man and animals. The safran 

 of metals is a violent emetic for human beings; in the horse it 

 only increases the transpiration ; a dose of the glass of anti- 

 mony, which produces violent vomiting in mankind, simply 

 purges the horse ; no poison will make a horse or a cow vomit. 

 Because the effects of medicines, therefore, on the lower animals 

 are so little known; because scarcely any one has observed closely 

 enough the diseases of cattle, or given certain rules for the ex- 

 hibition of proper remedies; because the use of remedies can 

 only tend to spread the contagion — for all these reasons it is 

 prudent to abstain from a dangerous tentative which promises 

 but little, and which may have the worst effects; and it is in- 

 finitely preferable to oppose the disease by means which are more 

 certain and commendable. 



