April 10, 1856. 

 Colonel SABINE, R.A., V.P. and Treasurer, in the Chair. 



The following communications were read : 



I. " Account of Experiments on the Vagus and Spinal Accessory 

 Nerves." By AUGUSTUS WALLER, M.D., F.R.S. Received 

 March 31, 1856. 



(Abstract.) 



The important functions of the organs more or less completely 

 dependent for their innervation on the vagus nerve, have afforded the 

 reason of so many attempts hy previous physiologists to determine 

 the exact influence exerted by the fibres arising from different 

 sources which are intimately blended together in the trunk of the 

 mixed vagus. Since Sir Charles Bell's discovery of the different func- 

 tions of the anterior and posterior roots of the spinal pairs, it has 

 become still more important to determine how far the same law holds 

 good with regard to the vagus nerve, and whether at its origin, it is 

 a purely sensory nerve, receiving its motor fibres from the internal 

 branch of the spinal accessory and perhaps from other sources. Ac- 

 cording to Bischoff and Longet, the vagus at its origin and as far as the 

 upper ganglion, is purely sensory, and becomes possessed of motor 

 power from its junction with the internal branch of the accessory, and 

 from other branches derived from motor nerves (Longet) . The obser- 

 vations of Bernard have led him on the contrary to adopt the opinion, 

 that the vagus at its origin is a mixed nerve ; because after destroying 

 the spinal accessory, no effect on the functions of the heart, stomach, 

 or lungs was observed, and the only organs visibly dependent on the 

 spinal accessory were the larynx and pharynx. After bearing testi- 

 mony to the correctness of the observations made by Bernard with 

 regard to the effects immediately following destruction of the spinal 

 accessory, the author considered it desirable to apply to the determina- 



