it 



CHEMICAL COMPOSITION OF MUSCLE. 203 



precipitated by ferrocyanide of potassium, showing that it belongs to the pro- 

 teine-conipounds. The following analyses of Muscle by Berzelius corre- 

 sponds very exactly with those since made by Braconnot, Schultz, Marchand, 

 and other Chemists : 



Fibrine (from the proper muscular substance) .... 15-80 



Gelatine (from areolar tissues) . . . . . 1'90 



Albumen and ha'inatine ........ 2'20 



Phosphate of lime, with albumen ...... '08 



Alcoholic extract, with salts (lactates?) 1-80 



Watery extract, with salts ........ 1'05 



Water, and loss 77-17 



100-00 



Thus something less than 23 percent, of solid matter exists in ordinary meat ; 

 and in 100 parts of this solid mattter, there are about 7 k parts of fixed salts. 



[Kreatine (from xjsaj, flesh), originally discovered by Chevreul, in 1835, has been proved 

 by the recent investigations of Liebig to be a constant ingredient of the muscles of all the 

 higher classes of animals. Schlossberger found it in the flesh of the alligator. Its crystals 

 are colorless, perfectly transparent, and of great lustre. They form groups, the character 

 of which is exactly similar to that of sugar of lead. Its formula is C 8 N 3 H n O 6 . It dissolves 

 easily in boiling water, and a solution saturated at 212 forms on cooling a mass of small bril- 

 liant crystals, and is nearly insoluble in cold alcohol. It is neither acid nor basic. From the 

 action of strong mineral acids, a new body of totally different chemical qualities, a true or- 

 ganic alkali is formed, which Liebig has called Kreatinine. It is easily obtained from the 

 hydrochlorate or the sulphate. Kreatinine is more soluble both in cold and hot water than 

 kreatine; it dissolves in boiling alcohol, and crystallizes on cooling. In its chemical cha- 

 racter it is analogous to ammonia. Its formula is C 8 N 3 H 7 O 2 . Researches on the Chemistry 

 of Food, byj. Liebig. London, 1847. M. C.] 



a. The exact correspondence in ultimate composition, between dried Muscle, and dried 

 Blood, according to the analyses of Playfair and Bockmanh, is not a little remarkable. The 

 following are their results. 



PlATFAIH. BOCKXAZTN. 



Muscle. Blood. Muscle. Blood. 



Carbon . . . 51-83 51-95 51-89 51-90 



Hydrogen . . . 7-57 7-17 7-59 7-33 



Nitrogen . . . 15-01 15-07 15-05 1508 



Oxygen . . . 21-36 21-39 21-24 21-21 



Ashes . . . 4-23 4-42 4-23 4-42 



It may be questioned, from these results, whether the amount of Hsematine in Muscle is not 

 greater than that which is represented by the previous analysis ; since a tissue composed of 

 Fibrine and Albumen alone, could not possess the same ultimate composition with one, in 

 which Hsrnatine is present in large proportion. 



b. Some very interesting researches have lately been made by Helmholtz,f on the changes 

 induced in the tissue by Muscular action. Powerful contractions were induced by electricity 

 in the amputated leg of a Frog ; and were kept up as long as the irritability was retained. 

 The flesh of the two limbs was then analyzed; and it was found that, in every instance the 

 water-extractive was diminished in the electrized muscle, to the extent of from 20 to 24 per 

 cent.; whilst the alcoholic extract was increased to about the same amount. Similar results 

 were obtained from experiments on warm-blooded animals; the amount of change, how- 

 ever, being less, on account of the shorter duration of thr muscular irritability. 



239. Muscular tissue, properly so called, is as extra-vascular as cartilage 

 or dentine; for its fibres are not penetrated by vessels ; and the nutriment 

 required for the growth of its contained matter must be drawn by absorption 

 through the myolemma. But the substance of Muscle, as a whole, is ex- 



* [The recent researches of Liebig make it exceedingly probable that lactic acid is a con- 

 stituent of muscle. Its purpose hi the animal organism will be alluded to hereafter. M. C.] 

 | Miiller's Archiv., 1845. 



