TEIFAC1AL NEEV1 .. 139 



Properties and Functions of the Trif octal. Our definite 

 knowledge with regard to the properties and functions of the 



e root of the fifth nerve dates from the experiments by 

 Mayo, published in 1822. It is generally stated by authors 

 that the researches of Sir Charles Bell, in 1811, led natural- 



. the idea that the ganglionic root of the fifth was entire- 

 ly nensory. We have already shown, by full references to 

 the paper printed by Sir Charles Bell, in 1811, that he there- 

 in attributed both motion and sensation to the anterior roots 

 of the spinal nerves, regarding the ganglionic roots as nerves 

 presiding over the functions of organic life. 1 The mistake 

 made by authors in attributing the exact distinction between 

 the functions of the large root of the fifth and the small root 

 and the facial arises from the fact that a paper published 

 originally in the Philosophical Transactions, in 1821, 2 is re- 

 printed with other memoirs, "with some additional explana- 

 tions." ! The additions to the original paper are in such a 

 form as to lead the reader to suppose that the author regard- 

 ed the large root of the fifth as exclusively sensory; but, in 

 the original paper, which we have carefully compared with 

 the reprint, the distinction between the motor and the sen- 

 sory root of the fifth is by no means clearly made. 



In 1822, Herbert Mayo published an account of " experi- 

 ments to determine the influence of the portio dura of the 

 seventh, and of the facial branches of the fifth pair of nerves." 

 These experiments consisted in dividing the infra-orbital, in- 

 ferior maxillary, and frontal branches of the fifth, and the 

 branch from the fifth to the seventh, in asses, by which 

 it was demonstrated that these were exclusively sensory 

 nerves. 4 In a second publication, the following year, it is 



1 See page 71. 



<J JiKi.L, On tJie Nerves ; giving an Account of some Experiments on their 

 Structure and Functions, which lead to a New Arrangement of t/ie System. 

 riuloHophical Transactions, London, 1821, Part i., p. 398. 



3 BELL, The Nervous System of the Human Body, as explained in a Series 

 of Papers read before the Royal Society of London, London, 1844, p. 33. 



4 MAYO, Anatomical and Physiological Commentaries, Number i., London, 

 1822, p. 107, et seq. 



