Mr. Shaw on the Facial Nerves. 239 



nerve, we hold the nostrils for a short time, so as to prevent the 

 animal from breathing, he will, when freed, begin to snort, but 

 with the left nostril only. If we hold carbonate of ammonia 

 to the paralyzed nostril, he will not be affected ; but if it be 



nient was at first so different from those which we had made in London 

 on the ass, and in which the nerves arc so similar to those of the horse, 1 

 took the first opportunity of again examining the anatomy of the nerve. 

 1 then discovered a good reason for my failure, as a large branch which 

 passes from the second division of the Vth. pair after running for a short 

 way, parallel to to the Portio Dura, joins with it. It was this branch I 

 had cut in the first part of the experiment. 



1 have since, with the assistance of my friend Mr. Ca'sar Hawkins, re- 

 peated the experiment on the horse, and which, I am happy to say, can 

 be done without giving the animal any pain, for the actions of the nostrils, 

 and the irritability of the nerves, especially of the respiratory class, conti- 

 nue so long after the animal is insensible, that, by cutting the Portio Dura 

 wc may stop the convulsions of the nostrils, and afterwards, by exciting 

 the nerve with the galvanic forceps, exhibit the peculiar set of actions 

 regulated by it. 



The experiment was made in the following manner: 



As soon as the animal became insensible from loss of blood, I cut through 

 the skin over the jugum, so as to expose the nerves passing down to the cheek 

 and nostrils The nostrils, during this time, were in convulsive action, and 

 corresponded with that of the chest. On cutting across the superior branch 

 (which though principally of the Vth., had some branches of the Vllth. inter- 

 mingled with it at the part cut,) scarcely any change was perceived ; 

 but on cutting the lower branch, which is almost entirely formed by the 

 Portio Dura, the convulsive actions of the muscles moving the nostril 

 immediately ceased. When this was repeated on the other side of the 

 face, the same consequences followed. On afterwards irritating the extre- 

 mities of the nerves with the galvanic fr)rceps , the actions of the muscles ol 

 the nostrils were excited when the inferior branch was toudicd,but little 

 or no effect was produced on touching.the upper (the branch of tlieVlh.) 



These circumstances afford a strong proof of the necessity of paying par- 

 ticular attention to the anatomy of the nerves, before wc draw any con- 

 clusions from experiments upon them. 



I may, however, observe that, although there was in this instance a 

 degree of culpability, all the experiments which have been made in the 

 present investigation have been founded on views taken from comparative 

 anatomy, and from observations made on the habits of the various classes 

 of animals; by following this plan the experiments have been sildom ..r 

 never alUndtU with conllicling rtsull.. 



