390 CHEMISTRY OF THE PROTEIDS CHAP. 



ton's myosinogen (v. Fiirth's myogen), which has escaped coagulation, and 

 which has been carried down mechanically by the paramyosinogen (v. 

 Fiirth's myosin). In addition we must remember that only a certain 

 proportion of the muscle-albumins separate out as insoluble substances, 

 and v. Fiirth makes the just observation, that a solidifying of the 

 muscle-plasma, comparable to blood-coagulation, is only seen in cold- 

 blooded animals. In warm-blooded animals the process amounts 

 simply to the formation of a little coagulum. We must, however, 

 not forget that during the preparation of the muscle -albumins a 

 certain amount of the paramyosinogen and of the myosinogen become 

 insoluble and that they are left behind in the muscle, v. Fiirth has 

 further observed that amongst other respects the coagulation in 

 situ differs from that in the test-tube in the rapidity with which it 

 occurs. 



What really determines the coagulation of paramyosinogen and 

 thereby gives rise to rigor mortis is not known. Halliburton regarded 

 it as being of a fermentative nature caused by the formation of 

 ' myosin -ferment ' in the dying muscle ; but now l he is doubtful 

 as to whether a specific myosin-ferment brings about the change. 



v. Fiirth could not find such a ferment, but does not exclude the 

 possibility of its occurrence. On the other hand, he showed that coagula- 

 tion is considerably hastened by lime salts, sodium thio-cyanate, sodium 

 salicylate, by an acid reaction, and by other factors. What causes the 

 disappearance of rigor mortis is also completely unknown. Kiihne 

 and many of the older investigators assumed that the solution of the 

 paramyosinogen was brought about by the formation of lactic acid iri 

 the dead muscle, but v. Fiirth found the quantity of lactic acid 

 liberated to be so small as to altogether exclude this explanation. 

 Vogel 2 and Schmidt - Nielsen 3 advance the hypothesis of autolytic 

 action ; but again Fiirth found no proteolytic ferments, while Sal- 

 kowski 4 found them only in the minutest traces. A possible ex- 

 planation is that the coagulum contracts within the sarcolemma, and 

 that it squeezes out the fluid contents in a manner analogous to 

 that occurring in coagulated blood. The observation of Man gold & 

 that muscle is still contractile after having passed through rigor 

 mortis seems to show that the chemical processes occurring during 

 rigor are not very profound. 



1 Halliburton, Handbook of Physiology, 1904, p. 156. 



2 R. Vogel, Deutsch. Arch. f. Min. Med. 72. 291 (1902). 



3 S. Schmidt-Nielsen, Hofmeister's Beitrage, 4. 182 (1903). 



4 E. Salkowski, Zeitschr.f. Min. Med. 17. Suppl. 77 (1890), 



5 E. Mangold, Pftugers Arch. 96. 498 (1903). 



