On the Composition of the Muscles in the Animal Series. 9 



Art. III. — On the Composition of the Muscles in the Animal Se- 

 ries ; by MM. Valenciennes and Fremy* 



The articles lately published by us on tlie composition of 

 eggs, show- that a comparative study of subjects related in or- 

 ganization, running through the different classes of the animal 

 kingdom, is always a source of much interest alike to zoology 

 and chemistry. Taking up the eggs of the principal groups of 

 animals, we pointed out fundamental differences in composition 

 which zoology should hereafter regard, and besides, we gave the 

 general characteristics of a new class of organic substances, des- 

 ignated by us under the name of vitellin substances, which 

 chemistry and physiology cannot confound with the albuminous 

 substances. 



Associating still our labors — which enables us to handle ques- 

 tions within the provinces both of zoology and chemistry, — we 

 have proposed to ourselves to extend to the muscular fibre the 

 mode of research which we have bestowed on eggs, that is, to 

 endeavor to exhibit, by a comparative study, the differences of 

 the muscles in chemical composition. A general examination 

 of the whole animal series should then give us tolerably pre- 

 cise notions of the nature of the proximate principles found in 

 the muscular fibre, as well as of the analytical processes by which 

 they may be isolated. 



Through our joint research, we have established several im- 

 portant facts which are brought out in this our first communica- 

 tion on the subject. 



The muscular fibre of the vertebrate animals, which we first 

 examined, was separated with the greatest care by anatomical 

 processes from the white aponeurotic or tendinous fibres, from 

 the nervous cords, the principal blood vessels, and also from the 

 fat which it contains in considerable amount. The proximate 

 principle which first appears in the analysis of- the muscles of 

 the Vertebrata is creatin, the discovery of which, as is well 

 known, is due to M. Chevreul. Then come inosic acid and crea- 

 tinin, which have been described with so much discrimination 

 and care by M. Liebig. In this part of our researches, we can 

 only confirm the labors of the well known chemists just named. 

 "We will mention, however, that creatinin appears to us more 

 abundant in the animal economy than is generally supposed ; 

 we have ascertained its presence in the muscular fibre of almost 

 all the Yertebrata ; it is often found in a free state, and is shown 

 by a very marked alkaline reaction ; we have found it too com- 

 bined with phosphoric acid. Our attention was next drawn to 



* Translated from the Journal de Pharmacie for December, 1855, p. 401, &c, by 

 Dr. J. Rosengarten. 



SECOND SERIES, VOL. XXII, NO. 64. — JULY, 1856. 2 



