296 REPORTS ON THE STATE OF SCIENCE. 



The account given by Mayo of Bell's opinion at that time is, in my 

 judgment, absolutely correct. Mayo says ('Outlines of Physiology,' 

 second edition, 1829, p. 332): — 



' The inference which Mr. Bell drew from these experiments was that the 

 branches of the fifth, which emerge upon the face to supply the muscles and 

 integuments, are for sensation and voluntary motion jointly; and that the use 

 of the seventh (the branches of which are distributed to the same parts) is to 

 govern the motions of the lips, the nostrils, and the velum palati when the 

 muscles of these parts arc in associated action with the mvscles of respiration. 

 In other words, according to Mr. Bell, the seventh is the nerve of instinctive 

 motion to the face, and the fifth of voluntary motion and sensation.' 



We must bear in mind that in this use of the term ' fifth nerve ' 

 both Bell and Mayo mean to denote ' portio major ' without definitely 

 distinguishing from it (as they might have done on the strength of the 

 publications of Soemmering and Palletta and Bellingeri) its ' portio 

 minor ' — the nerve of mastication or motor root of the fifth. This 

 distinction was a later development with Bell as with Mayo. The 

 latter is perfectly candid on this point and expresses himself as follows 

 (' Outlines,' p. 335): — 



' In pursuing this subject, I was led to observe that there were muscles 

 which received no branches from any nerve but the fifth; these muscles are 

 the masseter, the temporal, the two pterygoids, and the circumflexus palati. 

 These muscles again, I remarked, are supplied with branches from the third 

 division of the fifth, that is to say, from the particular division of the fifth, with 

 which the smaller fasciculus or root of the nerve is associated. After some care- 

 ful dissection, in the greater part of which I afterwards found that I had been 

 anticipated by Palletta, I made out that the smaller fasciculus of the fifth is 

 entirely consumed upon the supply of the muscles I have named ; to which it 

 is to be borne in mind that twigs from the ganglionic portion of the nerve are 

 likewise distributed. 



' But I had already ascertained by experiment that almost all the branches 

 of the larger or ganglionic portion of the fifth were nerves of sensation. I 

 proved this point in the ass, the dog, and the rabbit, respecting the second and 

 third division of the fifth; in the pigeon, respecting the first division. It was 

 therefore thoroughly improbable that the twigs sent from the same part of the 

 nerve to the muscles of the lower jaw should have a different quality, and be 

 nerves of motion. For this function it was reasonable to look to the other 

 nervous fibriles, which the masseter and temporal and pterygoid muscles receive, 

 in other words, to the branches of the smaller fasciculus or root or ganglionless 

 portion of the fifth. 



By the experiments and reasoning which I have described, I established 

 that the ganglionless portion of the fifth and the hard portion of the seventh 

 nerve are voluntary nerves to parts which receive sentient nerves from the 

 larger or ganglionic portion of the fifth. This happened before the publication 

 of M. Magendie's discovery of the parallel functions of the double roots of the 

 spinal nerves; and without wishing to assert the least claim to that discovery, 

 I will yet observe that I was led by the well-known anatomical analogy between 

 the fifth and spinal nerves, to conjecture nearly what M. Magendie proved, 

 and was indeed actually engaged in experiments to determine the point when 

 M. Magendie's were published.' 



IV. The passages in which Bell first alludes to the experiments of 

 Magendie occur in his fourth paper on the ' Nerves of the Orbit, ' in the 

 ' Philosophical Transactions ' for 1823, at pp. 306-7, and are as 

 follows : — 



'Anatomy is already looked upon with prejudice by the thoughtless and 

 ignorant ; let not its professors unnecessarily incur the censures of the humane. 



