COMPOUNDS OF ORGANIZATION. 73 



the action of boiling alcohol, which deposits, on cooling, the 

 suet, and retains the oil. The suet he has termed stearin, 

 and the oil elain. BRACONNOT effected their separation by 

 a much more simple process. He pressed the fatty or oily 

 matter, rendered sufficiently solid by cold, between folds of 

 soft paper. The oil is imbibed and the fat remains. To 

 free it from the remainder of the oil, the fat is melted with 

 a little oil of turpentine to dilute the oil, and again pressed 

 in paper. The oil is easily extracted from the paper by 

 boiling water. The suet or stearin, when thus obtained, is 

 dry and brittle, with a shining lustre, and resembles sper- 

 maceti. It melts at from 130 to 140 F. It is sparingly 

 soluble in alcohol and ether. All fatty substances consist 

 of different proportions of suet and oil. Butter contains 

 from 40 to 65 per cent, of suet ; hogs-lard 38 per cent ; 

 and marrow about 76 per cent. 



The fat of ruminating animals is termed tallow, and is 

 hard and brittle, while the fat of the hog, called lard, is soft 

 and semifluid. Its uses as an article of food, in the making 

 of candles, hard-soap, and ointments, and to diminish fric- 

 tion, are well known. 



4, Oil.-~ The various properties of the different kinds 

 of oils, depend, in a great degree, on the mode of pre- 

 paration, with the exception of the odour, which arises 

 from the kind of animal from which the oil has been de- 

 rived. Spermaceti oil is considered as the thinnest of the 

 animal oils, and the fittest for burning in lamps. It is 

 obtained from the spermaceti, by draining and pres- 

 sure. Tram oil is procured by melting the blubber, or 

 external layer of fat, found underneath the skin of diffe- 

 rent kinds of whales and seals. From the process em- 

 ployed, it contains, besides the oil, gelatine, albumen, and 

 other animal matters, which render it thick, dark-coloured, 

 and disposed to become rancid. Fish-oil is sometimes ex- 





