IXTERXAL BRANCH OF THE SPINAL ACCESSORY. 171 



obtained. In two succeeding experiments on dogs, the ani- 

 mals recovered. After division of the nerves, the voice 

 became hoarse ; but a few weeks later, became normal. On 

 killing the animals, an examination of the parts showed that 

 some of the filaments of origin had not been divided. An 

 experiment was then made upon a goat, but this was unsat- 

 isfactory, as the roots were not completely divided. Finally, 

 another experiment was made upon a goat. In this, the 

 results were most satisfactory. After division of the nerve 

 upon one side, the voice became hoarse. As the filaments 

 were divided upon the opposite side, the voice was enfeebled, 

 until finally it became extinct. The sound emitted after- 

 ward was one which could in nowise be called voice, "qui 

 neutlqi.iam vox appellari potuit" 1 This experiment was 

 made in the presence of Tiedemann and Seubertus, and was 

 not repeated. 



It is evident to any one familiar with the elaborate re- 

 searches of Bernard upon the spinal accessory, that it was 

 only necessary to confirm the single successful experiment 

 of BischofF to settle the fact of the influence of this nerve 

 upon phonation. The great difficulty of the operative pro- 

 cedure, however, prevented its repetition on an extended 

 scale. Longet, in 1841,* published an account of some ex- 

 periments confirming, to a certain extent, those of Bischoif; 

 but in his treatise on the nervous system, published in 1842,* 

 he does not seem to regard the spinal accessory as the exclu- 

 sive nerve of phonation, as he does in his work on physi- 

 ology, published after the experiments of Bernard. 4 The 

 results of the experiments performed at this time by Longet 



1 BISCHOFF, Nervi Accessorii Willisii Anatomia et Physiologia, Darmstadii, 

 1832, p. 94. 



s LOXGET, Recherches experimentalts sur les fonctions des nerfs, dcs muscles du 

 larnyx et sur F influence du nerf accessoire de Willis dan* la phonation. Gazette 

 mcdicale, Paris, 1841, 2eme serie, tome ix., p. 472. 



3 LOXGET, Anatomic et physiologic du systeme nerveux, Paris, 1842, tome ii., 

 p. 263. 



4 LOXGET, Trait* de pfiysiologie, Paris, 1869, tome iii., p. 516. 



