314 



FIFTH PAIR OF NERVES. 



was always more affected than the left. During 

 August the gums became separated on the 

 right from the necks of the teeth ; there existed 

 between the latter and the gums spaces into 

 which tartar and portions of food had pene- 

 trated ; the patient suffered from the epileptic 

 paroxysms with variable degrees of severity : 

 he next fell into a general cachexy, with extreme 

 debility, impeded respiration, small frequent 

 pulse, great alteration of countenance, and un- 

 usual taciturnity. It is stated that in August 

 he acknowledged deafness on the right, which 

 diminished and again increased; the sensibility 

 was perfectly preserved in all the extent of the 

 right side of the face ; the patient died on the 

 12th of August. Both the brain and the fifth 

 nerve were found after death much diseased, 

 the brain on the left and the nerve on the right 

 side. 



The details of the case have been given more 

 at length than may perhaps seem necessary, but 

 the question is interesting, and as the bearing 

 of the case upon it could not be determined 

 otherwise, the writer has endeavoured to 

 give them faithfully. The difficulty of obtain- 

 ing precise knowledge from so complicated a 

 case has been already adverted to. We come 

 next to inquire how far it substantiates the 

 writer's views, or how far it can be considered 

 to establish the opinion of Magendie. Serres, 

 as has been already stated, announces it as an 

 instance of disease of the fifth nerve followed 

 by loss of smell, sight, hearing, &c. Surely 

 the loss of these several functions, thus an- 

 nounced, should have been satisfactorily esta- 

 blished, before asserted ; but such does not 

 appear to have been the case. For the first, 

 notwithstanding the announcement, we find 

 Serres himself, after the patient's death, ac- 

 knowledging, " toutefois 1'odorat n'avait pas 

 completement disparu, puisque,"* &c. The 

 sense of smell then plainly was not lost. In 

 the next place there was loss of vision, but 

 from what cause ? from opacity of the cornea, 

 and, so far as we have data for forming a 

 judgment, from it alone. We have no reason 

 to think that any alteration had been pro- 

 duced in the power of the eye to receive 

 sensations of light, any disturbance in the 

 function of the retina, or any other change 

 than the occurrence of a physical impediment 

 to the exercise of a function, which the organ 

 may have retained in full vigour, had it only 

 been allowed to exert it: the evidence, there- 

 fore, afforded by the case, is too imperfect to 

 be of value. 



Let us next inquire how far it bears out the 

 opinion that the fifth nerve possesses a proper 

 and direct influence upon the nutrition of the 

 eye : here we shall find ourselves equally at 

 fault for the resemblance which it has been 

 sought to establish. In Magendie's experi- 

 ments the section of the nerve preceded the 

 occurrence of the phenomena, and it is reason- 

 able to expect, that, here, the loss of sensibi- 

 lity, which we are to regard as the analogue 

 of the section, should have preceded the oc- 



* Journ. dc Phys. t. v. p. 245. 



currence of the inflammation of the eye ; but 

 no. The patient had a chronic ophthalmia, con- 

 sidered scrofulous at the time of his admission; 

 (he was admitted in September, and in De- 

 cember he was attacked by acute ophthalmia, 

 attended by oedema of the lids ; a circumstance 

 not noticed in any of Magendie's experiments;) 

 the inflammation was dispersed, and in the 

 course of January, and not till then, (i. e. four 

 months after his admission and about one after 

 the occurrence of the second inflammation,) 

 the insensibility of the eye was for the first 

 time observed. Surely we have no reasonable 

 grounds here for attributing the inflammation 

 of the eye and the opacity of the cornea to the 

 disease of the nerve, or for supposing that there 

 existed any connexion, in the relation of cause 

 and effect, between them. If we seek for a 

 resemblance in other points, we shall be equally 

 disappointed. It has been already remarked 

 that cedema of the eyelids, which occurred in 

 this case, is not one of the phenomena of 

 Magendie's experiments. Again, the affection 

 of the gums related is altogether unlike : in 

 Serres' case they are stated to have become 

 inflamed, and to have been affected on both 

 sides, only more on the right than on the left ; 

 in Magendie's it is simply stated that they 

 separated from the teeth and only on the side 

 on which the nerve had been divided ; and, 

 lastly, the continuance of sensibility upon the 

 right side of the face throughout casts an im- 

 pervious obscurity over the entire. 



Besides those effects of the section of the 

 trunk of the nerve which have been discus- 

 sed, there are others, for which we are in- 

 debted also to Magendie, and which deserve 

 notice. 



He found after the section of the nerve that 

 the eye was dry, and the motion of winking 

 had ceased ; the globe of the eye itself seemed 

 to have lost all its motions ; the iris was 

 strongly contracted and immoveable. The loss 

 of sensibility in the conjunctiva, and the sus- 

 pension of the secretion of the tears, he refers 

 to the loss of the influence of the fifth nerve 

 upon the former part and upon the lachrymal 

 gland : the explanation of the first is in accor- 

 dance with the previously established proper- 

 ties of the nerve as already ascertained by Mayo, 

 but it is not equally so that the secretion of 

 the lachrymal gland is directly controlled by 

 the same influence, and it remains to be deter- 

 mined whether the effect in this case was not 

 an indirect one, consequent upon the previous 

 insensibility of the conjunctiva. The other re- 

 sults of the section the immobility of the 

 eyelids, that of the eye, and the permanent 

 contraction of the pupil he has not satisfac- 

 torily explained : the immobility of the lids 

 may, it appears to the author, be attributed 

 with much probability to the insensibility of 

 the conjunctiva or of the internal structures of 

 the eye, and seems a likely consequence there- 

 of: the ordinary action of winking would seem 

 to be called into play through the sensations of 

 those structures, and the cessation of that 

 action upon the loss of their sensibility is as 

 natural an effect as the immobility of the lips 



