1887.] 



and its Relation to Putrefaction. 



445 



kept afterwards in the air at a temperature of 9° C, in from 1 to 

 1^ hours — 3 to 3^- hours after death. When a trout is taken from the 

 landing net immediately after all signs of life have gone, and placed 

 in water at the same temperature (9°C.) the irritability continues 

 about 10 minutes longer, and the rigor is from 15 to 20 minutes later 

 in setting in. When the temperature is raised to 15° C. the irrita- 

 bility goes, and the rigor appears in from 20 to 30 minutes, and 

 reaches the caudal muscles about 45 minutes after death. At a tem- 

 perature of 25° C. the rigor may set in in 15 minutes, and be complete 

 in about 25 minutes after death, while at a temperature of 30° rigor 

 often comes on in the trout 5 minutes after death, and vanishes 15 or 

 20 minutes later. At a temperature of 38° C. heat rigor at once sets- 

 in. As the temperature is lowered the rigor is later in making its 

 appearance, and a considerable period elapses between the loss of mus- 

 cular irritability and the setting in of rigidity. At low temperatures 

 it is often extremely difficult to say at what time the stiffening begins. 

 A trout in water at 1° C. seemed to pass into rigor about 23 hours after 

 death; at —1° C. there was no distinct rigor 30 hours after death, 

 but well-marked stiffness 10 hours later, but at lower temperatures 

 (—7° to —20° C.) neither rigor nor stiffening could be detected in 

 four trout which had been respectively 2, 3, 4, and 5 days in the 

 freezing mixture. Further, trout which had been subjected to a tem- 

 perature below —7° C. never stiffened, even when introduced imme- 

 diately after thawing into water at a temperature of 25° C. 



Judging from the above and other experiments, it seems that 

 raising the temperature either before ©r after death has the same 

 influence as muse alar or nervous exhaustion in hastening the rigor. 

 The increased temperature quickens all the chemical and other 

 changes, and thus leads to the rapid and all but complete destruction 

 of the catabolic material stored up in the muscles. On the other 

 hand, cold either diminishes or arrests the metabolic changes. At a 

 temperature below freezing point the muscles contract, even when 

 stimulated less quickly, and hence they long retain almost unaltered 

 the contraction-producing material which happens to be present when 

 death sets in ; so that when the rigor eventually appears it, as already 

 mentioned, more resembles a mechanical coagulation of the muscles 

 than a strong contraction. It is difficult to determine whether the 

 rigor, which appears at a low temperature (5° to — 1° C), is really 

 stronger than the rigor that comes on at a high temperature. When 

 a trout, in which the rigor has set in at a temperature of 2° C, is 

 placed in water at a temperature of 25° C, stiffening vanishes in 

 about the same time as it would had the rigor set in at a temperature 

 of 20° C. 



The intensity and duration of the rigor which follows death in 

 warm-blooded animals from lightning has been again and again 



