642 NERVOUS SYSTEM. 



ment and mucous membranes of the face and head is usually supplemented by serious 

 disturbances in the nutrition of the eye, the ear, and the mucous membranes of the nose 

 and mouth. At a period varying from a few hours to one or two days after the opera- 

 tion, the eye upon the affected side becomes the seat of purulent inflammation, the cor- 

 nea becomes opaque and ulcerates, the humors are discharged, and the organ is destroyed. 

 Congestion of the parts is usually very prominent a few hours after division of the nerve. 

 At the same time, there is an increased discharge from the mucous membranes of the 

 nose and mouth upon the affected side, and ulcers appear upon the tongue and lips. It 

 is probable, also, that disorders in the nutrition of the auditory apparatus follow the oper- 

 ation, although these are not so prominent. Animals affected in this way usually die in 

 from fifteen to twenty days. 



One of the most interesting facts, particularly in view of the information derived from 

 later observations, in connection with the early experiments of Magendie, is, that he 

 noted that " the alterations in nutrition are much less marked " when the division is 

 effected behind the ganglion of Gasser, than when it is done in the ordinary way through 

 the ganglion. It is difficult enough to divide the nerve completely within the cranium, 

 and is almost impossible to make the operation at will through or behind the ganglion ; 

 and the phenomena of inflammation are absent only in exceptional and accidental in- 

 stances. Magendie offers no satisfactory explanation of the differences in the consecu- 

 tive phenomena coincident with the locality of section of the nerve. The facts, how- 

 ever, have been abundantly verified. In the numerous experiments that we have made 

 upon the fifth pair, we have generally noted the consecutive inflammatory phenomena in 

 the order above described ; but, in exceptional instances, these phenomena have been 

 wanting. The following experiment illustrates these exceptional operations : 



February 6, 1868, the fifth pair of nerves was divided upon the left side in a full- 

 grown rabbit in the ordinary way, before the class at the Bellevue Hospital Medical Col- 

 lege. There followed instant and complete loss of sensibility upon the left side of the 

 face. Four days after, the animal having been fed ad libitum with cabbage, the loss of 

 sensibility was still complete. There was very little redness of the conjunctiva of the 

 left eye, and a very slight streak of opacity, so slight that it was distinguished with diffi- 

 culty. Twelve days after the operation, the sensibility of the left eye was distinct but 

 slight. There was no redness of the conjunctiva, and the opacity of the cornea had dis- 

 appeared. The animal was in good condition, and the line of contact of the upper with the 

 lower incisors, when the jaws were closed, was very oblique. The animal was kept alive 

 by careful feeding with bread and milk for one hundred and seven days after the opera- 

 tion, there never being any inflammation of the organs of special sense. It died at that 

 time of inanition, having become very much emaciated. The animal never recovered 

 power over the muscles of mastication of the left side, and the incisors grew to a great 

 length, interfering very much with mastication, which seemed to be the cause of death. 



Longet, in 1842, furnished a satisfactory explanation of the absence of inflammation 

 in certain cases of division of the fifth. He attributed the consecutive inflammation in 

 most experiments to lesion of the ganglion of Gasser and of the sympathetic connections, 

 which are very numerous at this point. These sympathetic filaments are avoided when 

 the section is made behind the ganglion. 



The explanation of the phenomena of disordered nutrition in the organs of special 

 sense, particularly the eye, following division of the fifth, is not afforded by the section 

 of this nerve alone ; for, as we have seen, when the loss of sensibility is complete after 

 division of the nerve behind the Gasserian ganglion, these results may not follow. Nor 

 are they explained by deficiency in the lachrymal secretion, for they are not observed 

 when both lachrymal glands have been extirpated. They are not due to exposure of the 

 eyeball, for they do not follow upon section of the facial. Nor are they due simply to an 

 enfeebled general condition, for, in the experiment we have detailed, the animal died of 

 inanition after section of the nerve, without any evidences of inflammation. In view of 



