CHEMIC COMPOSITION OF THE HUMAN BODY 23 



PRINCIPLES OF DISSIMILATION 



In addition to the previously mentioned compounds viz., carbo- 

 hydrates, fats, proteids, and inorganic salts there is obtained by chemic 

 analysis from the tissues and fluids of the body: 



1. A number of organic acids, such as acetic, lactic, oxalic, butyric, pro- 

 pionic, etc., in combination with alkaline and earthy bases. 



2. Organic compounds, such as alcohol, glycerin, cholesterin. 



3. Pigments, such as those found in bile and urine. 



4. Crystallizable nitrogen-holding bodies, such as urea, uric acid, xanthin, 

 hippuric acid, creatin, creatinin, etc. 



While some few of these compounds may possibly be regarded as neces- 

 sary to the physiologic integrity of the tissues and fluids, the majority of 

 them are to be regarded as products of dissimilation of the tissues and foods 

 in consequence of functional activity, and represent stages in their reduction 

 to simpler forms previous to being eliminated from the body. 



