

THE MUSCULAR JUICE. 87 



Scherer* has also described several volatile acids, belonging to 

 the group C n H n . 1 O 3 + HO, which he found in the muscular juice ; 

 amongst these, acetic and formic acids were conspicuous. 



It has generally been assumed that the muscles derived their 

 colour from the quantity of blood contained in them; but we 

 incline rather to Kolliker'sf view, that there is a special colouring 

 matter in the muscles. This pigment is very similar to that of the 

 blood. It assumes a brighter red tint in the air, and is rendered 

 darker by sulphuretted hydrogen ; it may be extracted by water, 

 and coagulates with the albumen of the muscular juice. These 

 properties might dispose the chemist to regard the pigment of the 

 muscle as identical with the colouring matter of the blood ; but 

 certain physiological grounds indicate that this pigment is not 

 contained in vessels and blood-corpuscles, but adheres in a free 

 state to the fibrils ; the muscles retain their colour during vital 

 contraction; colourless muscles are frequently as rich in blood- 

 vessels as those which are strongly coloured ; and a yellow colour 

 may sometimes even be distinctly detected under the microscope 

 in particular bundles. 



The inorganic constituents are of considerable importance in 

 the muscular juice, as well as in every other fluid ; and we are 

 indebted to LiebigJ for the light which he has thrown on this sub- 

 ject by his carefully conducted observations. The inorganic, like 

 the organic substances, must be regarded as something beyond 

 mere incidental constituents of the muscular juice. This fluid, 

 like most acid fluids, is rich in potash salts and phosphates, but 

 poor in salts of soda and chlorides. It would appear, from 

 numerous determinations of Liebig, that the relation of potash to 

 soda in the blood of certain animals, on the one hand, and in the 

 muscular juice of the same animals on the other, is about as fol- 

 lows : in the ash of both fluids there occur, for 100 parts of soda, 



In the hen 40-8 of potash in the blood, and 381 in the muscular juice. 

 ox 5-9 279 



horse 9'5 285 



fox 214 



pike 497 



It must be borne in mind that the muscular juice can never be 



* Ann. d. Ch. u. Pharm. Bd. 69, S. 196-201. 

 t Mikrosk. Anat. Bd. 2, S. 248. 



t Researches on the Chemistry of Food. Edited by William Gregory, M.D., 

 Professor of Chemistry in the University of Edinburgh. London, 1847. 



