76 



NERVOUS SYSTEM. 



touched. "When, at the same time, a bundle of the poste- 

 rior root is cut, there is produced a movement in totality in 

 the limb to which the bundle is distributed. 



" I repeated the same experiments on the anterior roots, 

 and I obtained analogous results, but in an opposite sense ; 

 for the contractions excited by the contusion, the pricking, 

 etc., are very forcible, and even convulsive, while the signs 

 of sensibility are hardly visible. These facts are, then, con- 

 firmatory of those which I have announced ; only they seem 

 to establish that sensation is not exclusively in the posterior 

 roots, any more than motion in the anterior roots. Never- 

 theless, a difficulty may arise. When, in the preceding ex- 

 periments, the roots had been cut, they were attached to the 

 spinal cord. Might not the disturbance communicated to 

 the cord be the real cause either of the contractions or of 

 the pain which the animals experienced ? To remove this 

 doubt, I repeated the experiments after having separated 

 the roots from the cord ; and I must say that, except in two 

 animals, in which I saw contractions when I pinched or 

 pulled the anterior and posterior roots, in all the other in- 

 stances I did not observe any sensible effect of irritation 

 of the anterior or posterior roots thus separated from the 

 cord." 1 



Magendie then goes on to say that, when he published 

 the note in the preceding number of the journal, he sup- 

 posed that he was the first who had thought of cutting the 

 roots of the spinal nerves ; but he was soon undeceived by 

 a letter from Mr. Shaw, who stated that Bell had divided the 

 roots thirteen years before. Magendie afterward received 

 from Mr. Shaw a copy of Bell's essay (" Idea of a New Anat- 

 omy of the Brain "), and, as will be seen by the following 

 extract, gave Bell full credit for all his observations : 



" It is seen by this quotation from a work which I could 

 not be acquainted with, inasmuch as it had not been pub- 

 lished, that Mr. Bell, led by his ingenious ideas concerning 



1 Ibid., p. 368. 



