MUSCLE 589 



was again allowed to reach them. He performed a similar 

 experiment with artificial circulation through the hand of an 

 executed criminal, with a like result. But grave doubt has 

 been cast upon these experiments by later observations, and 

 it is now almost universally believed that no really rigid 

 muscle has ever been restored, and that the apparent re- 

 covery which Brown-Sequard saw was due to the muscles 

 not having been completely rigid. Heubel has, however, 

 stated that the rhythmical contractions of the frog's heart 

 can be restored by filling its cavity with blood, after rigor 

 has been caused by heat and in other ways ; and although 

 we cannot transfer these results directly to skeletal muscle, 

 they would show, if confirmed, that the question is not yet 

 closed. 



