Protein — AJhuminoids 61 



some authors, vitellin. If finely divided, well- washed 

 muscle (lean meat) is treated with a 10 per cent salt 

 solution, first by rubbing it in a mortar with fine salt, 

 and then adding enough water to secure the proper 

 strength of solution, a globulin is dissolved to which 

 the name myosin has been given. The view has been 

 generally accepted that this compound does not exist 

 as such in living muscle, but forms there by coagula- 

 tion upon the death of the animal. This change has 

 been looked upon as similar to the coagulation of blood 

 through the formation of fibrin, and is regarded as the 

 explanation of the stiffening of dead muscles (rigor 

 mortis). The theory is held that a "mother" substance 

 exists in the living muscle from which mj-osin is formed 

 in much the same way as fibrin is developed in clottiug 

 blood from a preexisting body, but no single view as to 

 exactly what occurs is fully accepted. Thei-e is, never- 

 theless, a general agreement that rigor mortis is due 

 to a clotting of the muscle, accompanied by marked 

 chemical transformations, one final product being my- 

 osin. The theory is advanced that ferments are present 

 in the muscle, to the influence of which these changes 

 are due, and without which they do not occur, but 

 proof of this view is still lacking. In this whole field 

 much is yet to be learned. Certainly, the chemistry of 

 living and dead muscle is most profound, and offers to 

 the bio- chemist a wonderfully attractive and fruitful 

 field of research. 



Another prominent and remarkable globulin is the 

 fibrinogen, which is found in the blood. It is common 

 knowledge that when blood is drawn from the veins 



