TRJFACIAL NERVE. 193 



its division, taken in connection with its physiological anat- 

 omy. The nerve has never been exposed in the cranial 

 cavity in living animals ; but its branches upon the face and 

 the lingual branch of the inferior maxillary division have 

 been operated upon and found to be exquisitely sensitive. 

 Longet and others have exposed the roots in animals imme- 

 diately after death, and have found that galvanization of the 

 large root carefully insulated produces no muscular contrac- 

 tion. 1 All who have divided this root in living animals 

 must have recognized, not only that it is sensitive, but that 

 its sensibility is far more acute than that of any nervous 

 trunk in the body. It is much more satisfactory to divide 

 the nerve without etherizing the animal, as the evidence of 

 pain is an important guide in this delicate operation ; but 

 in using anaesthetics, we have never been able to bring an 

 animal under their influence so completely as to abolish the 

 sensibility of the root itself. For example, in cats that ap- 

 pear to be thoroughly etherized, as soon as the instrument 

 touches the nerve, there is more or less struggling. The 

 large root of the fifth, then, is an exclusively sensory nerve > 

 and its sensibility is more acute than that of any other of 

 the cerebro-spinal nerves. 



The distribution of the branches of the large root of the 

 fifth indicates that it is the great sensitive nerve of the face. 

 It will be remembered, however, that its branches go large- 

 ly to the organs of special sense, and it is an interesting 

 question to determine whether or not these branches be en- 

 dowed with special as well as general sensibility. 



Magendie thought, from his experiments upon animals, 

 that the fifth nerve was endowed with special sensory prop- 

 erties. He states distinctly that section of the nerve is im- 

 mediately followed by loss of taste, smell, hearing, and sight, 

 on the side operated upon. 8 This view, however, has not 



1 LOXGET, Traite de physiologic, Paris, 1869, tome iii., p. 487. 

 - MAGEXDIE, Suite des experiences sur les fondions de la cinquieme paire d 

 nerfs. Journal de physiologic, Paris, 1824, tome iv., p. 305, et scg. 



In another volume of the same journal, Magecdie reports a case ha which the 



