THE IMPROVED ART OF FARRIERY. 367 



of bein^ resolved into the same principle as those 

 of the latter. Thus, by repeated distillations, we ob- 

 tain from animal substances, water, oil, air, an easy 

 destructible salt, and charcoal. These secondary 

 principles, are, by farther processes, at length resoluble 

 into the same proximate principles which we find in 

 vegetables, viz., air, earth, and water, and the principle 

 of inflammability. 



But though the principles of vegetable and animal 

 substances are fundamentally the same, yet these 

 principles are combined in a very different manner. 

 It is exceedingly rare that animal substances are ca- 

 pable of the vinous or acetous fermentation, and the 

 putrefactive, into which they run remarkably fast, is 

 also different in some particulars from the putrefaction 

 of vegetables. The smell is much more offensive in 

 the putrefaction of animal than of vegetable sub- 

 stances. The putrefaction of urine, is, indeed, accom- 

 panied with a peculiar fetor, by no means so intolerable 

 as that of other animal matters ; this is, probably, 

 owing to the pungency of the volatile alkali, and also 

 to the urine containing less inflammatory matter than 

 the blood and other fluids. When analysed by a 

 destructive heat, animals afford products very different 

 from those of vegetables ; the empyreumatic oil has a 

 particular and much more foetid odour, and the volatile 

 salt instead of being an acid, found as it is in most 

 vegetables, is found in animals to be a volatile 

 alkali. 



Chemists have spoken of an acid procurable from 

 animal substances, and indeed, certain parts of animal 

 bodies are found to yield a salt of this kind ; but it by 

 no means is the case with animal substances in general; 

 and though the proofs to the contrary were even con- 

 clusive, it is confessedly in so small a quantity as not 



