276 SOLID PARTS OF ANIMALS. 



the water being changed each time, the same boiling process was 

 repeated every day for three weeks ; at the end of which time 

 the water afforded only slight signs of gelatin when infusion of 

 oak bark or chloride of tin was added. After this the fibrous 

 part was well pressed, and was dried by the heat of the water- 

 bath. Muscle thus treated is as pure as it can be made by any 

 known process. The cold water removes the blood and lymph, 

 and the hot water dissolves the cellular substance, and converts 

 it into gelatin. The minute blood-vessels and nerves, which 

 cannot be separated mechanically, still remain. 



Muscle thus treated contracts in its dimensions, has a dirty- 

 yellow colour, and is brittle, and easily reduced to powder. 

 Though steeped in water, it does not recover its former flexibi- 

 lity. 100 parts of muscle when dried are reduced to 17 parts, 

 so that the solid portion does not much exceed a sixth part 

 of the whole. 



Muscle not boiled, when digested in acetic acid, is converted 

 into a jelly, which dissolves in water; but the solution is muddy, 

 and very difficult to filter. When the solution is left long at 

 rest, a quantity of fatty matter collects on the surface, and a 

 grey matter is deposited, consisting (probably) of minute blood- 

 vessels which have not dissolved in the acid. 



Dilute caustic potash dissolves it when assisted by a gentle 

 heat. The solution is muddy, and can scarcely be filtered. 

 What remains undissolved is probably cellular matter, which 

 dissolves also when the temperature of the solvent in raised. 

 When muriatic acid is poured into the alkaline solution, a com- 

 pound of the acid and fibrin precipitates, which may be washed 

 in dilute muriatic acid ; but dissolves in water, becoming in the 

 first place gelatinous and transparent. 



When washed muscle is exposed to pressure there exudes a 

 red liquid, which does not coagulate like blood, and which has 

 the property of strongly reddening litmus-paper. To obtain 

 the whole of this liquid we must digest the muscle in water. 

 This liquid was subjected to a chemical examination by Berze- 

 lius. He obtained, 



1. Albumen. When the liquid is heated it becomes muddy at 

 122, and a copious precipitate falls at 126, in colourless flocks, 

 which are easily separated by the filter. This precipitate be- 

 comes white when washed The liquid from which the precipi- 



