440 PRACTICE OF PHYSIC. 



increasing the surprise and amusement which his motions occa- 

 sion in the bystanders. 



MCCCLII. In this disease, the mind is often affected with 

 some degree of fatuity ; and often shows the same varied, de- 

 sultory, and causeless emotions which occur in hysteria. 



MCCCLIII. These are the most common circumstances of 

 this disease; but, at times, and in different persons, it is varied by 

 some difference in the convulsive motions, particularly by those 

 affecting the head and trunk of the body. As in this disease 

 there seem to be propensities to motion, so various fits of leap- 

 ing and running occur in the persons affected ; and there have 

 been instances of this disease, consisting of such convulsive mo- 

 tions appearing as an epidemic in a certain corner of the country. 

 In such instances, persons of different ages are affected, and 

 may seem to make an exception to the general rule above laid 

 down ; but still the persons are, for the most part, the young 

 of both sexes, and of the more manifestly moveable constitu- 

 tions. 



" In this fashion, it generally attacks both sexes at a partic- 

 ular time of life, from ten years of age to sixteen ; sometimes 

 it appears earlier, sometimes it subsists longer ; but it is gen- 

 erally limited to that, or to a still narrower period, from twelve 

 to fourteen. Now this circumstance gives us a degree of theory 

 which will apply to the cure. It may be considered in two ways : 

 1. From a view of the sanguiferous system ; till the system is in 

 its several parts fully evolved, there is no considerable tension 

 or firmness in the whole. Now the full evolution of all parts 

 of the system takes place at the age of puberty, at which time 

 the genital system is evolved. Only at the age of puberty, 

 therefore, does the system acquire any degree of tension and 

 firmness ; but towards its approach, that is, within a few years 

 of puberty, the cause of evolution being little steady, now more 

 intense and then more remiss, occasions a fluctuation of the bal- 

 ance of the system, and a state of the mobility which lays a foun- 

 dation to these convulsive disorders. 2. From a view to the 

 nervous system. We observe that the state of the genitals, 

 in both sexes, has a considerable influence upon the whole nerv- 

 ous system, particularly in giving it a state of tension or tone ; 



