284 SOLID PARTS OF ANIMALS. 



tity of a yellow powder, similar to that ofapothem. Its solution is 

 not precipitated by corrosive sublimate, protochloride of tin, nor 

 acetate of lead. But with diacetate of lead it gives a copious preci- 

 pitate, which redissolves when acetate of lead is added. Nitrate 

 of silver throws down a yellowish grey precipitate, and infusion 

 of nut-galls renders it opal. 



The solution in absolute alcohol is yellow, and contains a mat- 

 ter, which, being freed from alcohol and dissolved in water, is pre- 

 cipitable by infusion of nut-galls. If we dissolve this precipitate 

 in boiling water, precipitate the tannin by acetate of lead, throw 

 down the excess of lead by sulphuretted hydrogen, and filter and 

 evaporate the liquid, we obtain a transparent substance having 

 very little taste. Its aqueous solution is yellow, and exhibits 

 with reagents nearly the same characters as the preceding sub- 

 stances. 



Such is an abstract of Berzelius's experiments on the expres- 

 sed juice of muscle. If we attend to the various vessels which 

 exist in muscle, arteries, veins, and lymphatics, it must be ob- 

 vious that a portion of these different substances must be derived 

 from the liquids contained in these vessels. But the liquids con- 

 tained in arteries, veins, and lymphatics are alkaline, while the 

 liquid from the muscle contains an excess of lactic acid, and 

 much more phosphate of lime than exists in blood or lymph. It 

 is not in our power, in the present state of our knowledge, to ex- 

 plain the origin of these matters, nor of the numerous extractive 

 matters which have been described. It is not unlikely that some 

 of the substances described by Berzelius may have been pro- 

 duced by the various processes to which the liquor of muscle 

 was subjected. Much light would be thrown on the subject by 

 the ultimate analysis of the different extractive substances, espe- 

 cially of that one which has the taste and smell of roasted-meat, 

 provided it could be obtained in a state of sufficient purity. Perhaps 

 the precipitate which it forms with oxide of lead or oxide of sil- 

 ver might enable a good experimenter to determine its atomic 

 weight and its ultimate constitution. 



I am not aware that any muscles have been subjected to analy- 

 sis except those of the ox. Hatchett and Berzelius made their 

 experiments on the lean of beef, while Braconnot analyzed the 

 heart of an ox. The following table exhibits the result of the 

 analyses of Berzelius and Braconnot : 



