ANIMAL PRINCIPLES. 



The same arrangement which was followed in the Chemistry 

 of Vegetable Bodies may also be applied to animal bodies. We 

 shall first give an account of the animal principles., so far as their 

 nature and constitution have been determined. In the second 

 place, the different parts, both liquid and solid, of which the ani- 

 mal body is composed, will be described ; and in the third place, 

 we shall treat of those animal functions which are likely to be 

 elucidated by chemistry. 



DIVISION I. 



OF ANIMAL PRINCIPLES. 



The substances which have hitherto been detected in the ani- 

 mal kingdom, and of which the different parts of animals are 

 supposed to be composed, may be arranged under the following 

 heads : 



1. Animal acids. 



2. Animal bases. 



3. Intermediate oxides. 



4. Colouring matters. 



5. Amides? 



These will be described in succession under their respective 

 heads. 



CLASS I. 



OF ANIMAL ACIDS. 



Several of these acids have been described in the Chemistry 

 of Inorganic Bodies, (Vol. ii. 45.) But so much has been done 

 by chemists since the year 1831, when that work was published, 

 that it will be necessary to resume the account of them here, re- 

 ferring to the former work for every thing which does not re- 

 quire to be corrected or amended. 



The acids derived from the animal kingdom, which have been 

 recognized by modern chemists, and more or less accurately ex- 

 amined, amount to about 40. They are all compounds of two, 

 three, four or five different constituents. The following table 

 exhibits the composition of such of them as have been subjected 

 to analysis : 



