336- THE POPULAR SCIENCE MONTHLY. 



But another specially interesting fact with regard to epilepsy is 

 this, tliat, a few days after the operation, whether made on the spinal 

 cord or the sciatic nerve, it is found that an area of skin on the same 

 side with the nerve destroyed or the spinal cord injured, which is 

 limited by the line extending from the anterior extremity of the 

 eye to the end of the nose, thence, comprising the upper lip, running 

 along the neck to the shoulder, and then in a straight line to the 

 posterior extremity of the ear, and, lastly, to the posterior angle 

 of the eye, by degrees loses certain faculties and acquires new 

 ones. The sensation of pressure, of squeezing, of heat, cold, or elec- 

 tricity, of pain in a word, all disappear ; only the faculty of feeling 

 tickling persists, and that appears exaggerated. In an experiment 

 which I made some years ago, this effect followed within two hours 

 of the operation on the upper spinal cord. 



It is seen at the same time that tickling this zone gives rise at 

 first to involuntary twitchings in the muscles of the jaw, of the eyes, 

 and of the nose, on the same side ; by degrees those twitchings be- 

 come more strong and more general, then they manifest themselves on 

 the other side also, and after a few weeks the animal has regular con- 

 vulsions after each tickling of the zone, which lastly culminate in a 

 regular attack of epilepsy, of which the features are the following: 

 When the attack begins, the head is drawn first, and with great vio- 

 lence, at times toward one shoulder, at times toward the other. This 

 has been explained by the contraction of the muscles of the neck. 

 The mouth is drawn open by the same cause, and the muscles of the 

 face and of the eyes, which had twitchings, now contract violently 

 also. At this period it would appear that the muscles of the larynx 

 are contracted to some extent. At all events, it appears that the vo- 

 cal cords are contracted, for not unfrequently the animal utters an 

 inarticulated, unnatiiral, sharp cry, which may be taken for the pas- 

 sage of air through the obstructed larynx. It then falls. The mus- 

 cles of the legs are contracted stifi*, those of the chest are thoroughly 

 so ; very soon all the muscles are the seat of convulsions. Respira- 

 tion, which was in no little degree impeded during the time that 

 the muscles of the chest were rigid, now becomes more frequent but 

 very irregular. After a while the animal recovers, and remains in 

 a state of stupidity for some time. It "is not unfrequent to observe 

 in these epileptic seizures fits of insanity if I may use such a term 

 when speaking of Guinea-pigs, but that word only will make my 

 meaning understood. When these animals have been su..ering for 

 some months, it is seen that they have fits without apparent provoca- 

 tion ; that is to say, spontaneously. 



When they recover from the epileptic taint, all the phenomena 

 observed about the zone of skin in the neck and face recur in the re- 

 verse order ; that is to say, all the different sensations return by de- 

 grees, at the same time that the hair of that region falls, and new 



