THE OXIDIZING SUBSTANCE AND MYOSINOGEN. 



241 



their suppleness and translucency, and acquire a certain amount 

 of rigidity. There is, however, one very marked and impor- 

 tant difference between the rigor mortis of muscle and the 

 coagulation of blood. Blood during its coagulation undergoes 

 a slight change only in its reaction; but muscle during the 

 onset of rigor mortis becomes distinctly acid." 



If myosinogen were the precursor of the myosin of rigor 

 mortis, what would its composition probably be and how would 

 it become metamorphosed into myosin? 



We have submitted the data sustaining our view as to the 

 existence of the oxidizing principle, and have referred to it 

 as a body derived from the suprarenal glands, which, in pass- 

 ing through the lungs, entered into loose combination with 

 oxygen. The labors of Schmiedeberg, Salkowsky, Jaquet, 

 Abelous and Biarnes were quoted to show that such a prin- 

 ciple had also been found by chemical methods, though its 

 origin remained unknown to them. 



If combustion of products of nuclein metabolism in the 

 blood-plasma, through the presence therein of oxidizing sub- 

 stance, can produce uric acid, it seems reasonable to conclude 

 that, if this same substance is also present in myosinogen, we 

 should find evidence of a similar action. Not only is this the 

 case, but the same products of metabolism are found in mus- 

 cle-serum: the liquid portion of muscle-plasma obtained by 

 rubbing up and expressing fresh muscle. Though obtained 

 only in very small quantities, the purin bases, creatin, xanthin, 

 hypoxanthin, and creatinin, are always found in addition to 

 their end-product, uric acid. Phosphoric acid a combustion 

 product accounted for by the presence of the phosphate of 

 potassium is another link between muscular plasma and that 

 of the general blood-stream. Of course, these various bodies 

 should not be considered as elements of muscular activity. 

 Their history indicates that, along with other albuminoids 

 found, they are mere passive hosts of the muscular plasma as 

 waste-products of muscular tissue-metabolism, destined to be 

 converted here, as elsewhere in the organism, into harmless 

 bodies, acids or others. 



The active constituents of myosinogen, as far as muscular 

 irritability and contractility are concerned, must be of another 



