TO HYDROCARBONACEOUS PROXIMATE PRINCIPLES. 



Stearine, C 57 H 110 C , 



So called from the readiness with which it assumes the solid form, is a 

 main ingredient of the more consistent fats. It liquefies, when pure, at 

 about 60 (1400 p.^ an( j a g a i n solidifies when the temperature falls to 



or a little below this point. It 



Fig- 8- crystallizes, on cooling from a 



warm solution in oleine, in fine 

 radiating needles which often 

 follow a wavy or curvilinear 

 direction. It is rather less 

 freely soluble in alcohol and 

 ether than the other fatty sub- 

 stances. 



Palmitine, C 51 H 98 6 , 

 Was first recognized as an in- 

 gredient of palm oil, a semi- 

 solid fat obtained from the 

 seed of an African palm. It 

 crystallizes, on cooling from its 

 concentrated alcoholic or ethe- 



STEABiNE,cryBtallizedJrom a warm solution in real so l u tion, in the form of 



slender needles. It liquefies 



about the temperature of 46 (115 F.). It is found in considerable 

 abundance in a variety of animal and vegetable fats. 



Oleine, C 57 H 104 6 . 



As its name indicates, this is the representative ingredient of the oils, 

 or liquid fatty substances. When pure it is transparent and colorless. 

 It retains its fluidity at all ordinary temperatures, and even below the 

 freezing point of water. It readily dissolves both stearine and palmi- 

 tine, its solvent power for these substances increasing w r ith the elevation 

 of the temperature. 



None of these oleaginous substances occur naturally in an isolated 

 form, but they are mingled together in varying proportions in all the 

 ordinary animal and vegetable fats and oils. The consistency of the 

 mixtures varies with the relative quantity of their different fatty ingre- 

 dients. Thus the more solid fats, such as suet and tallow, consist 

 largely of stearine ; the softer fats, as lard, butter, and the ingredients 

 of human adipose tissue, contain a greater abundance of palmitine; 

 while the liquid fats, like the fish oils, olive oil, and nut oil, are 

 composed mainly of oleine. As a general rule, in the bodies of the 

 warm-blooded animals these mixtures are fluid, or very nearly so, in 

 consistency ; for, although both stearine and palmitine, when pure, are 

 solid at the ordinary temperature of the body, they are held in solu- 

 tion during life by the oleine with which they are associated. After 



