90 THYSIOLOGY OF MUSCLES AND NERVES. 



itself, and that this coagulation represents the essential 

 fact in death-stififening. 



Death-stiffening intervenes, as we found, earlier 

 in proportion as the temperature is higher. Exactly 

 the same is the case in expressed muscle-fluid. If it 

 is heated to a temperature of 45° C. it coagulates 

 in a few minutes, becoming acid at the same time. 

 Muscles also, if they are heated to a temperature of 

 45° C, undergo death-stiffening in a few minutes. If 

 they are still further heated, up to or above a tempe- 

 rature of 73° C, they contract into shapeless lumps, 

 become quite hard and white, and exhibit a firm solid 

 tissue resembling the white of eggs when cooked. 

 From this it may be inferred that, besides the matter 

 which coagulates during the death-stiffening, other 

 soluble albuminous bodies are also present in muscle, 

 and that these act as ordinary albumen as it occurs in 

 blood and in eggs ; for the latter also coagulates when 

 heated to 73° C. It therefore appears that various kinds 

 of albumen occur in muscle. That which coagulates 

 at 45°, or, though somewhat more slowly, in the or- 

 dinary temperature of a room, is called myosin. It 

 may be assumed that this albuminous body is natu- 

 rally soluble, but that it is rendered insoluble by the 

 acids occurring within the muscle. Death-stiffening 

 would accordingly be the result of the formation of 

 acid. Our knowledge on this point is, however, yet 

 very incomplete, and must remain so until chemistry 

 has afforded more fidl explanation of the nature of 

 albuminous bodies. 



