366 DISEASES OF THE PERIPHERAL NERVES. 



structive guidance of this book, suffices to impart the degree of skill 

 requisite to impress the uninitiated. 



The curative effect of strychnine upon peripheral palsy may be 

 placed by the side of that of the induced current. Nor does strych- 

 nine at all tend to promote the union of divided nerves, nor repair the 

 structural changes which have caused the palsy. On the other hand, 

 it is probable that this drug, by exciting reflex action in the spinal 

 column, and through the augmented reflex excitement thereby induced 

 in the motor nerves, may stimulate the irritability of the latter, where 

 it is not already completely extinguished. In order to obtain results 

 from strychnine, doses must be given of sufficient size, and must be 

 kept up long enough to produce visible effect upon the reflex action of 

 the spinal marrow that is, until slight twitching is induced. We 

 prescribe either the alcoholic extract of nux vomica, one-third of a 

 grain, gradually increasing up to two grains, or the nitrate of strych- 

 nine, in dose from the twelfth to the fourth of a grain. Other medica- 

 ments, such as arnica and rhus toxicodendri, scarcely have any effect 

 upon peripheral palsy. 



CHAPTEE XX. 



ETIOLOGY. In the coming chapter we leave unnoticed the variety 

 of facial palsy arising from suspended volition, which is almost always 

 accompanied by hemiplegia, and constitutes a common symptom of 

 apoplexy, and of other diseases of the brain. 



The irritability of the facial, or of its attachment to the brain, may 

 be impaired : 1. By causes which act upon it prior to its entrance into 

 the internal auditory meatus. 2. By such as affect it during its course 

 through the petrous bone. 3. By agents which involve the peripheral 

 ramifications upon the face. Within the cranium the facial nerve is 

 most frequently compressed or destroyed by cerebral tumors springing 

 from the base of the skull, or which have advanced toward its base. More 

 rarely it proceeds from exudation, from thickening of the dura mater, 

 or from exostoses. In the canal of Fallopius the nerve is more fre- 

 quently destroyed by caries of the petrous bone, although one or two 

 cases have been observed in which fractures and gunshot wounds have 

 caused injury of the facial within the petrous bone. The peripheral 

 oranches are sometimes cut, either by accident or intentionally, during 

 surgical operations. Thus it was with the coachman who was so 

 thankful to Sell for the successful extirpation of a tumor about his 

 ear, but who complained that since the operation he could no longer 

 wliistle to his horses. The continuous pressure which the ramifications 



