318 MR. BEI.L ON TI^E NERVES OF THE, FACE. 



ring to them here, since I am desirous that the Society's Transactions should 

 contain only the philosophical part of the inquiry. 



The system of Willis, of which we have an elegant account in the posthu- 

 mous works of Dr. Baillie, prevailed universally in the schools when I entered 

 on these inquiries. In opposition to that system I demonstrated that the 

 nerves hitherto supposed to possess the same powers, consisted of filaments 

 having different roots, and performing different functions. I found myself 

 embarked in this investigation, from observing the course which the nerves took 

 in their distribution through the body. Conceiving that the devious course 

 and reunion of the nerves were for a purpose, I sought in their origins for the 

 cause of their seeming irregularity. It was discovered that the roots of the 

 nerves arose from distinct columns of nervous matter, and that on these columns 

 depended their different properties. Those which were called the common 

 nerves, that is, the nerves which arise from the spinal marrow, thirty in number, 

 were found to consist each of two nerves derived from distinct columns, one 

 for sensation and one for motion. In the further pursuit of this subject, there 

 was reason to conclude that the spinal marrow contained not only the columns 

 for bestowing sensation and motion, but also another column, the office of 

 which was to combine the actions of respiration. I then drew the attention of 

 the Society to the course of the fifth nerve of the brain according to Willis. 

 I showed that it had the same double root as the spinal nerves, that it had a 

 ganglion, and that part of the nerve passed free of the ganglion ; and that from 

 all these points of resemblance, it was to be considered as the anterior or 

 superior of the spinal nerves, of that system which is called symmetrical, 

 and which ministers to the same functions in all classes of animals, bestowing 

 sensibility and the locomotive powers, but deficient in those filaments which 

 command the respiratory motions. I am particular in restating this, because 

 from time to time it has been reported that I had abandoned my original 

 opinions ; whereas every thing has tended to confirm them. 



From the general view of the nervous system, I drew attention to the super- 

 added or irregular nerves. Having shown that the original or symmetrical 

 system of nerves, of which the fifth was one, had no power over the motions 

 of respiration, and that the human countenance in all its motions, with the 

 exception of mastication, bore relation to the actions of respiration, it was 



