338 HAND-BOOK OF PHYSIOLOGY. 



In addition to the above ferments, many others most likely exist in the 

 body, of which the following are the most important: 



6. Fibrin-forming ferment (Schmidt), (see p. 69, et seg., Vol. I.) 

 found in the blood, lymph and chyle. 



7. A ferment which converts glycogen into glucose in the liver; being 

 therefore an amylolytic ferment. 



8. Urinary ferments. 



(b.) Organic non-nitrogenous bodies consist of (1.) Oils and fats. 

 (2.) Amyloids. (3.) Acids. 



(1.) OILS AND FATS. 



Saponifiable. 



Palmitin C 51 H 90 6 



Stearin C 57 H 110 6 



Olein ...... 



Non-saponifiable. 

 Cholesterin .... 20 H 44 



Stercorin ? 



Excretin 78 H 160 SO a 



Constitution. 



Tlie Saponifiable fats are formed by the union of fatty acid radicals 

 with the triatomic alcohol, Glycerin 3 H 5 (OH) 3 . The radicals are IS 

 H 35 0, 16 H 18 0, and C J8 H 33 0, respectively. Human fat consists of a 

 mixture of palmitin, stearin, and olein, of which the two former con- 

 tribute three-quarters of the whole. Olein is the only liquid constituent. 



General characteristics. Insoluble in water and in cold alcohol; sol- 

 uble in hot alcohol, ether, and chloroform. Colorless and tasteless; easily 

 decomposed or saponified by alkalies or superheated steam into glycerin 

 and the fatty acids. 



Non- Saponifiable. CJiolesterin, 26 H 44 O, is the only alcohol which 

 has been found in the body in a free state. It occurs in small quantities 

 in the blood and various tissues, and forms the principal constituent of 

 gall-stones. It is found in dropsical fluids, especially in the contents of 

 cysts, in disorganized eyes, and in plants (especially peas and beans). It 

 is soluble in ether, chloroform, or benzol. It crystallizes in white feathery 

 needles. See also under the head of the constituents of the bile. 



Excretin (Marcet), and Stercorin (Flint), are crystalline fatty bodies 

 which have been isolated from the faeces. 



(2.) AMYLOIDS. 



Amyloids. Under this head are included both starch and sugar. The 

 substances, like the fats, contain carbon, hydrogen, and oxygen; but the 

 last-named element is present in much larger relative amount, the hydro- 

 gen and oxygen being in the proportion to form water. 



The following varieties of these substances are found in health in the 

 body. 



