594 MOTION. 



came on in 10 hours, and lasted 192 hours ; in the second, 

 which was feebly electrified, it commenced in seven hours, 

 and lasted 144; in the third, which was more strongly 

 electrified, it came on in two, and lasted 72 hours ; in the 

 fourth, which was still more strongly electrified, it came 

 on in one hour, and lasted 20 ; while, in the last rabbit, 

 which was submitted to a powerful electro -galvanic cur- 

 rent, the rigidity ensued in seven minutes after death, and 

 passed away in 25 minutes. From this it appears that 

 the more powerful the electric current, the sooner does 

 the rigidity ensue, and the shorter is its duration ; and as 

 the lightning shock is so much more powerful than any 

 ordinary electric discharge, the rigidity may ensue so early 

 after death and pass away so rapidly as to escape detection. 

 The influence exercised upon the onset and duration of 

 post-mortem rigidity by causes which exhaust the irritability 

 of the muscles, was well illustrated in further experiments 

 by the same physiologist, in which he found that the rigor 

 mortis ensued far more rapidly, and lasted for a shorter 

 period in those muscles which had been powerfully elec- 

 trified just before death than in those which had not been 

 thus acted upon. ; 



The occurrence of rigor mortis is not prevented by 

 the previous existence of paralysis in a part, provided the 

 paralysis has not been attended with very imperfect nutri- 

 tion of the muscular tissue. 



The rigidity affects the involuntary as well as the volun- 

 tary muscles, whether they be constructed of striped or 

 unstriped fibres. The rigidity of involuntary muscles with 

 striped fibres is shown in the contraction of the heart 

 after death. The contraction of the muscles with un- 

 striped fibres is shown by an experiment of Valentin, who 

 found that if a graduated tube connected with a portion 

 of intestine taken from a recently-slain animal, be filled 

 with water, and tied at the opposite end, the water will in 

 a few hours, rise to a considerable height in the tube, 



