22 THE POPULAR SCIENCE MONTHLY. 



and encouraged it, until at last various moral irregularities grew up, 

 of a kind that made the Pope think it a very undesirable thing, and it 

 was then put down by ecclesiastical authority ; yet it was still prac- 

 tised in secret for some time longer, so that it is said that even until 

 the beginning of the last century there were small bands of flagellants 

 in Italy, who used to meet for this self-mortification. 



That was one form in which a dominant idea took possession of the 

 mind and led to actions which might be called voluntary, for they 

 were done under this impression, that such self-mortification was an ac- 

 ceptable offering. But thei-e were other cases in which the action of the 

 body seemed to be in a very great degree involuntary, just about as 

 involuntary as an hysteric fit, and yet in which it was performed 

 under a very distinct idea ; such was what was called the " Dancing 

 Mania," which followed upon this great plague. This dancing mania 

 seemed in the first instance to seize upon persons who had a tendency 

 to that complaint which we now know as St. Vitus's dance St. Vitus 

 was, in fact, the patron saint of these dancers. St. Vitus's dance, or 

 chorea, in the moderate form in which we now know it, is simply this, 

 that there is a tendency to jerking movements of the body, these move- 

 ments sometimes going on independently of all voluntary action, and 

 sometimes accompanying any attempt at voluntary movement ; so that 

 the body of a person may be entirely at rest until he desires to exe- 

 cute some ordinary movement, such as lifting his hand to his head to 

 feed himself, or getting up to walk ; then, when the impulse is given 

 to execute a voluntary movement, instead of the muscles obeying the 

 will, the movement is complicated (as it were) with violent jerking ac- 

 tions, which show that there is quite an independent activity. The 

 fact is, that stammering is a sort of chorea. We give the name of 

 chorea to this kind of disturbance of the nervous system, and the action 

 of stammering is a limited chorea chorea limited to the muscles con- 

 cerned in speech, when the person cannot regulate the muscles so as to 

 bring out the words desired ; the very strongest effort of his will can- 

 not make the muscles obey him, but there is a jerking, irregular action 

 every time he attempts to pronounce particular syllables. And the 

 discipline that the stammerer has to undergo in order to cure or alle- 

 viate his complaint is just the kind of discipline I have spoken of so 

 frequently the fixing the attention on the object to be gained, and 

 regularly exercising the nerves and muscles in proceeding from that 

 which they can do to that which they find a difficulty in doing. That 

 is an illustration of the simpler form of this want of definite control 

 over the muscular apparatus, connected with a certain mental excite- 

 ment ; because every one knows that a stammerer is very much affected 

 by the condition of his feelings at the time. If, for example, he is at 

 all excited, or if he apprehends that he shall stammer, that is enough 

 to produce it. I have known persons who never stammered in ordi- 

 nary conversation, yet when in company with stammerers they could 



