156 THE POPULAR SCIENCE MONTHLY. 



objects. There is also a sensibility belonging to the muscles. When 

 we make a motion that of closing the hand, for example we are not 

 only aware of the effort we make to move the fingers and shut up the 

 hand, but we also know that the movement is executed. Everything 

 takes place as if the muscles were sensible, and each of the muscular 

 contractions actually provokes a sensation. We should also distinguish 

 between tactual and muscular sensibility and the sensibility to pain. 

 When the skin is burned, Or cut, or torn, the violent shock suffered by 

 the nerves gives rise to a particular sensation, of which we have all had 

 more or less experience, and which is called pain. The word is so 

 clear and the thing so common that no other definition than the word 

 itself is needed. 



Some extremely curious observations may be made with patients 

 who are wholly anaesthetic. We may prick them, pinch them, burn 

 them, without their feeling the slightest pain. They do not perceive 

 the contact of the objects that wound them. An experiment which 

 always creates astonishment in persons who are not acquainted with 

 medical practice is, to bandage the eyes of a patient, and scratch along 

 her arm from place to place with a fine needle without her receiving 

 the least intimation from her senses that she is wounded. 



Anaesthesia is sometimes general and equally marked on the right 

 and left sides, sometimes limited to a particular region of the body, as 

 the forehead, the chest, or the forearm. Partial anaesthesia may occur 

 even with patients who are only a little hysterical. If we seek to 

 measure the sensibility of the different regions by pricking the skin 

 lightly with a pin, we will often find a small zone of skin that is in- 

 sensible. The Inquisitors of the sixteenth century had no other way 

 of proceeding than this when they sought for the claw of the devil, 

 only that, instead of touching the skin with pins, they made the execu- 

 tioner stick skewers of iron into all parts of the body. If the accused 

 did not jump with pain at every implantation of the iron, they imme- 

 diately declared that the devil had put his grip on her. The stigma 

 of Satan was one of the most certain evidences of witchcraft. Accord- 

 ing to the most precise tokens of the exorcists, the devil's mark had 

 the shape of a hare's paw. 



Hysteric anaesthesia is often seated on only one side of the body ; 

 the affection in this form is called hemianesthesia. The insensibility 

 is so exactly limited to one side, that it is enough to go two or three 

 riillimetres to the right or left of the middle line of the body to estab- 

 lish the fact of the presence of sensibility or of its absence. 



Although many researches have been made to discover the causes 

 of this derangement of the nervous system, no satisfactory solution of 

 the question has been reached yet. It seems to be proved that no ma- 

 terial organic injury is connected with hysteria. The nerves of the 

 affected side have the same appearance as the nerves of the healthy 

 side ; the marrow and the brains show no swelling, no haemorrhage. 



