MUSCLES. 281 



liquid over it is yellow. When decomposed by sulphuretted hy- 

 drogen, the residual liquid reacts as an acid. When concentrat- 

 ed to a certain point, the extractive which it contains may be pre- 

 cipitated by absolute alcohol, while the uncombined acid remains 

 in solution. It is a brown magma, having a slightly bitter taste. 

 It is soluble in water, and the solution has a brown colour. This 

 aqueous solution is copiously precipitated by infusion of nut-galls 

 and corrosive sublimate ; but not by acetate of lead, protochlo- 

 ride of tin, or nitrate of silver. Diacetate of lead precipitates it 

 abundantly. We obtain also a complete precipitate when, after 

 having added protochloride of tin, we pour in a quantity of caus- 

 tic ammonia. 



When protochloride of tin is added to the yellow liquor which 

 has been already precipitated by corrosive sublimate, a new pre- 

 cipitate falls, which is colourless, and from which sulphuretted 

 hydrogen gas separates an almost colourless extractive, which is 

 tasteless, and exhales an animal odour when burnt. Its solution 

 is neither precipitated by acetate of lead nor infusion of nut-galls. 

 The quantity of it is inconsiderable. 



(2.) Extractive Matter soluble in Water but not in Alcohol. 

 Alcohol of 0-833 leaves a brown and opaque matter, having an 

 agreeable taste of meat or beef-tea. It has an acid reaction, and 

 contains lactic acid, which may be extracted in the following way : 

 Dissolve the extractive matter in water, saturate it with carbonate 

 of ammonia added in slight excess. Evaporate to the consistence 

 of a syrup, and mix the residue with alcohol of O833. The lac- 

 tate of ammonia, together with two extractive substances, will be 

 dissolved. 



If we dissolve in water what remains after the evaporation of 

 the alcohol, and add infusion of nut-galls to the solution, a pre- 

 cipitate falls, which, though not quite insoluble in water, is yet 

 almost wholly separated by an excess of tannin. After having 

 collected this precipitate on a filter, and subjected it to pressure, 

 it is.soluble in boiling water, and the tannin may be separated 

 from it by acetate of lead. The precipitate being separated, and 

 the excfess of lead thrown down by sulphuretted hydrogen, the 

 liquid, when evaporated, leaves a yellow extractive matter, hav- 

 ing the smell and taste of toasted bread, and soluble in water, to 

 which it communicates a pale yellow colour. Its solution in wa- 

 ter gives a copious white precipitate with corrosive sublimate ; 



