1058 SOLID PARTS OF ANIMALS. 



of prints, it must occasionally be formic acid. Its fixed con- 

 stituents amount to from \ to ]J per cent, and consist of an 

 undetermined animal matter, sal ammoniac, lactate of ammonia, 

 chloride of sodium, and the other usual salts. 



Muscle. The threads or fibres of muscle consist essentially of 

 fibrin (page 1024), but in addition to fibrin, several other sub- 

 stances are present, of which the nature is very imperfectly 

 known. Flesh strongly dried, leaves about 23 per cent of solid 

 matter, the other 77 per cent are water. Of the dry mass, about 

 6 per cent dissolves in water. Water extracts from hashed 

 meat, about 17 per cent of its weight. This extract of meat is 

 partly soluble in alcohol and partly insoluble. It is a mixture 

 of salts with several organic substances, of which the true 

 nature is still very doubtful. These undetermined extractive 

 matters occur also in urine and most of the animal fluids. To 

 one of them, soluble in both water and alcohol, and the cause of 

 the odour of cooked meat, the name osmazome has been ap- 

 plied, but the matter so named has not the characters of a pure 

 substance. 



The fibrin of all animals is similar, for it has been found by 

 Liebig, that the flesh of the ox, the deer, the cod and pike do 

 not differ in composition. 



The composition of ligaments, cartilage, tendons, &c. has 

 already been described (p. 1036). 



Fat. Human fat appears to contain no stearine, but only 

 margarine (page 959), and oleine (page 965). Tallow, or the 

 melted fat of oxen and sheep, on the other hand, consists chiefly 

 of stearine (page 961), with a little oleine. It forms excellent 

 hard soaps ; in the preparation of which, the melted tallow is 

 boiled with a solution of caustic soda, weak at first, but gradu- 

 ally increased in strength; the soap floats upon the alkaline 

 liquor, in which it is insoluble, while the glycerine of the tallow, 

 which has been replaced in combination with the stearic and 

 oleic acids, by soda, is dissolved by the water. In the forma- 

 tion of the common diachylon plaster, 9 parts of olive oil and 

 some water are boiled with 5 parts of levigated litharge ; a com- 

 pound of margaric and oleic acids with the oxide of lead results, 

 which forms a plastic mass, and is an insoluble soap. Hog's 

 lard contains more oleine than tallow, and is softer ; it probably, 

 like human fat, contains margarine, although stearine also is 

 undoubtedly present. 



