Scientific Intelliyence — Zoology. 386 



Since liis first investigation on this subject, the author has studied 

 a greater number of electrical fishes, and has directed his attention 

 particularly to their nervous system, more especially of the brain. 

 He has endeavoured to determine anatomically whether there was in 

 the general structure a certain central organ (a ganglionic mass) 

 combined with the brain and spinal marrow, in which the nerves of 

 the electric organ might originate, or whether the ganglionic sub- 

 stance necessary to this structure, instead of being apparent to the 

 eye, may not be often merged in different parts of the interior of the 

 brain or spinal marrow. He has endeavoured to ascertain, in the 

 second place, whether, in the first general case, the original plan of the 

 structure of the brain, which, among vertebrates, evidently presents 

 the most simple form, undergoes any modification by the appearance 

 of these accessory ganglions, or whether these organs are connected 

 with the general plan, or whether they constitute an ulterior deve- 

 lopment of the already existing portions of the brain. 



The author's observations refer to Torpilla, the Narcine, Gym- 

 notus electricus, and the electrical Malapterus of the Nile, and it 

 appears to result from them, both in a morphological and in a phy- 

 siological point of view, that it is extremely doubtful whether the 

 brain be the seat of a nervous centre for the electrical apparatus ; he 

 rather thinks that this centre exists either in the medulla oblongata, 

 or in the spinal marrow. 



10. Dr J. Y. Simpson on the ** Effects of Chloroform on Lower 

 Animals : — 



(I.) In animals belonging to the class Articulata, complete local 

 and limited anaesthesia can be produced by the local and limited ap- 

 plication of the vapour or liquid of chloroform to individual parts of 

 the body of the animal. 



(2.) In Batrachian Reptiles, the tail, or an individual limb, can bo 

 affected in the same way with local anaesthesia, by the local appli- 

 cation of the chloroform ; but, in addition, general anaesthesia of the 

 animals usually results in a short time, in consequence of the chloro* 

 form absorbed by the exposed part coming to afiect the general system. 



(3.) In the smaller Mammalia a single limb, or even the whole 

 lower or pelvic half of the body, can be rendered anaesthetic by local 

 exposure of these parts to the influence of chloroform. 



11. Effects of Local Ancesthesia on the Human Body : — 



(1.) In the human subject, partial, and perhaps superficial, local 

 anaesthesia of a part, as the hand, can be produced by exposing it to 

 the strong vapour of chloroform ; but the resulting degree of this 

 local anaesthesia is not sufficiently deep to allow the part to be cut 

 or operated upon without pain. 



(2.) Any agent possessing a stronger local benumbing or an anees- 

 thelic influence, would probably be dangerous, by its acting too 

 powerfully on the general economy, before the local ancesthesia was 

 established to a depth sufficient for operating. 



