FUNCTIONS OF MOTOR AND SENSORY NERVES 85 



In a later publication — Thomson's Annals of Philosophy, 

 July 181 5— he says : 



" It appears then that there is a species of circulation in the 

 nervous system, of which I have sketched the general course, 

 as curious and admirable as that which exists in the vascular 

 (the centre of the one being the heart, of the other the head); 

 and that there is scarcely any point of the body which this 

 circle does not involve and rest on, since from almost every 

 point ascends impression to the cerebrum by a nerve of sensa- 

 tion, the anterior nervous roots, and the anterior columns of 

 the spinal marrow, and to each returns expression from the 

 cerebellum by the posterior columns, the posterior nerve-roots 

 and the nerves of volition." 



Bell preferred his claim to Magendie's discovery at once, 

 in 1822, by proxy, through John Shaw, the same brother-in-law 

 who had gone over to Paris in 182 1 to show Bell's experiments 

 on the facial nerves. Magendie at once printed John Shaw's 

 reclamation in his Journal de Physiologie (vol. iii. 1822, p. 270) 

 and acknowledged it with a liberality of which Bell and his 

 followers subsequently took advantage. Magendie, who at 

 that time regarded Bell as a serious worker, accepted Bell's 

 statement that he had cut the anterior and posterior roots as 

 meaning what he, Magendie, meant when he talked about 

 cutting anterior and posterior roots, i.e. section in vivo, not, 

 as he subsequently found, section post mortem. And so he 

 allows Bell the credit of having cut the spinal roots before 

 he did and of having very nearly discovered their functions. 

 This concession of Magendie's was more than Bell ever 

 deserved; the experiment of 18 ri to which Bell alludes was 

 made not on the living but on the recently killed animal ; 

 he inferred from his results, not that the anterior root was 

 motor and the posterior sensory but that the anterior root 

 was the cerebral {i.e. motor and sensory) channel and the 

 posterior root the cerebellar (i.e. secret and vital) channel. The 

 younger Shaw — Alexander— subsequently made capital out of 

 this admission of Magendie's 1 ; even at the present day its 

 consequences persist in the form of the loose statement that 



1 A. Shaw (Narrative of the Discoveries of Sir Charles Bell in the Nervous 

 System : London, 1839) says at p. 156 : " In the succeeding number of his Journal 

 of Physiology (October 1822), or two months after writing his first paper, 

 M. Magendie admitted that the experiments on the roots of the spinal nerves, 

 which he had claimed as original, had been performed many years before by 

 Sir Charles Bell." 



