1861.] on the Nutrition and Reparation of Nerves. 381 



The speaker then referred to the important conclusions to which 

 the knowledge of the functions of these nerves so obtained had led 

 MM. Claude Bernard and Brown-Sequard, and Dr. Waller, more 

 especially as to the influence exerted by the sympathetic nerve over 

 the circulation in the blood-vessels ; and he mentioned a most in- 

 teresting result which the latter had quite recently discovered, viz., 

 that a powerful influence could be exerted on the functions of the 

 heart, lungs, stomach, &c., by pressure on the vagus nerve in the neck ; 

 and that this could be carried so far as to produce complete insensi- 

 bility. He considered this fact to be not only of much physiological 

 interest, but also of great practical importance, as it provided us with 

 a new means of producing anaesthesia ; and he also believed that it 

 might be made very useful in facilitating the diagnosis of certain 

 nervous affections. 



The researches of MM. Philippeaux and Vulpian, two French 

 physiologists, which were in continuation of Dr. Waller's, had shown 

 that the regenerative powers of nerves were even greater than he 

 had mentioned ; for they had found that a nerve could be regenerated, 

 though unconnected with its centre, and even when transplanted to 

 another part of the body. 



The speaker then referred to the influence over the nutrition of 

 nerves, which Dr. Waller's researches had shown their ganglia to 

 possess, and to the corroboration which they gave to the theory of the 

 centrical action of the ganglia and of the cells of which they were 

 composed. If a nerve that was attached to a ganglion was divided a 

 little way from its point of attachment, all the fibres below the section 

 were decomposed, whilst those in connection with the ganglion retained 

 their healthy structure, even though the connection of the ganglion 

 itself with the great centres (the brain or spinal cord) was broken off". 

 This showed that the ganglion maintained and regulated the vitality 

 of the fibres which were attached to its cells. A ganglion, therefore, 

 was to the fibres connected with it what a fountain was to the rivulet 

 that trickled from it, a source of nutritive energy. 



In conclusion, he drew attention to the extensive results which 

 often flowed from very simple observations, instancing the discoveries 

 above mentioned which had all more or less followed from his obser- 

 vance of the simple fact that a nerve-fibre when separated from its 

 centre became disorganized ; and he impressed upon his audience that 

 the knowledge of the functions of the body in health was the only sure 

 basis of treatment of its derangements in disease. 



[A. W.] 



