268 SPECIAL HISTOLOGY. 



§ 85- 



Chemical and physical Relations of the Muscles. — In 100 

 parts of fresh beef there are contained, according to Bibra, 

 72'56 — 7445 parts of water. The solid constituents (25'55 — 

 27'44) in a man 59 years old, were composed of a residue 

 insoluble in boiling water, alcohol, and set her, 16 - 83 ; soluble 

 albumen and colouring matter, 1*75 ; substance affording 

 gelatine, 1 "92 ; extractive matter and salts, 2-80 ; fat, 4-2 It. 

 The fat is derived chiefly from the blood, the fat-cells in the 

 muscles and their nerves, and in part perhaps from the mus- 

 cular fibres themselves, in which microscopic fat granules are, 

 at all events occasionally, evident. The gelatine is derived 

 from the perimysium, in smaller proportion also from the 

 vessels and neurilemma; none, on the contrary, is afforded by 

 the sarcolemma, which is still apparent in muscles completely 

 exhausted by boiling, whence (in opposition to Reichert) it is 

 evident that the sarcolemma should not be referred to con- 

 nective tissue. The inorganic salts and the albumen are 

 principally afforded, probably by the muscular fibre itself, as 

 are also and above all the salts described by Liebig and Scherer 

 in the juice of muscles, of the lactic, acetic, butyric, and formic 

 acids, the free lactic acid, the creatin and creatinin, the sugar 

 of muscles or inosit, and the colouring matter, which sub- 

 stances, even the last-named, are lodged partly in the fibrils 

 themselves, partly and chiefly, and this is the case especially 

 with the albumen, in the interstitial substance, by which the 

 fibrils are connected together. The 16-83 parts of insoluble 

 residue belong in part to the elastic tissue in the vessels and 

 perimysium, and to the smooth muscle in the vessels, but 

 principally to the muscular fibrils themselves, which, as we 

 have before seen (§ 27), consist of a substance allied to fibrin. 

 The sarcolemma is less affected by alkalies and acids than the 

 fibrils, and approaches in its nature more nearly to the rnem- 

 brana propria of the glands, the walls of the capillaries, and 

 the membrane of many cells. The colouring matter of the 

 muscles (and the muscles themselves), like the blood, becomes 

 bright red in the air, or still more in oxygen gas, and is rendered 

 dark by sulphuretted hydrogen. It is extracted, and indeed 

 readily, by water, but not by salts, in which circumstance, that 



