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



mer, pure and without any mixture of other organs, we chose 

 the mass of muscles bundled together in the tail, taking care to 

 put aside the extremity of the intestinal canal and the nervous 

 cord which follows it. 



The muscles thus prepared, were submitted to the action of 

 different solvents, especially alcohol and ether. They proved to 

 be simpler in composition than those of the Mammalia, and pre- 

 sented some analogy to the muscles of fish. The phosphate of 

 potash which is so largely found in the former, hardly occurs in 

 the Crustacea ; the oleophosphoric acid exists however in as con- 

 siderable quantity as in the muscles of fish. We obtained also 

 creatin and creatinin from the muscles of several different kinds 

 of crustaceous animals. 



To complete this general study of the muscles of different ani- 

 mals, it remained to examine the Mollusca, which on analysis, 

 afforded a remarkable and unlooked for fact. To enable us to 

 compare these analytical results with those we had arrived at 

 in the other animals, we used great care in the preparation of 

 the muscular tissue of the mollusks intended for our experi- 

 ments. For example, in working on the large muscle of the 

 Cephalopods, we took away the bone of the cuttle fish, and the 

 tail of the ' calmar,' we put aside all the membranes which touch 

 the cavity enclosing the secretions, and we raised the cartilages 

 which operate on the corresponding tubercles of the body, in the 

 movements of these large muscles. In the acephalous molluscs 

 we took only the large abductor muscles of the valves. In one 

 word, avoiding all the products of the secretions, and all the or- 

 gans of complex composition so plentiful in these animals, which 

 are so often called simple bodies, our analyses were applied to the 

 pure muscular fibre of the Mollusca, from the order of the Ceph- 

 alopoda to that of the Acephala. The delicacy of the prepara- 

 tions had a great influence on the nicety of the analytic results 

 which we are now to make known. 



The muscles of mollusks presented a much simpler compo- 

 sition than those of the vertebrated animals, for they do not 

 contain any appreciable quantity of phosphate of potash, of oleo- 

 phosphoric acid, of creatin or of creatinin : these proximate 

 principles are replaced by a crystalline material which is ob- 

 tained as plentifully from oysters as from the cuttle-fish, and may 

 be called a characteristic of the muscles of these animals. It is 

 much more soluble in boiling water than in cold, insoluble in al- 

 cohol and ether, combines with neither acids nor bases, and resists 

 the action of nitric acid. When submitted to the action of heat, 

 it gives all the products which result from the decomposition of 

 organic azotized substances, and with sulphuric acid, affords both 

 the sulphite and the sulphate of ammonia. The presence of sul- 

 phur in the crystalline matter of the mollusks has been confirmed 

 by the analyses, which resulted thus ; 



