GLASS III. 1. 2. 1. OF VOLITION. 305 



pears to be produced by the intemperate use of spirituous po- 

 tation, and is in all of them hereditary; it seems probable, that 

 this disposition gradually increases from generation to generation 

 in those families which continue for many generations to be in- 

 temperate in this respect; till at length these diseases are produc- 

 ed; that is, the irritability of the system gradually is decreased 

 by this powerful stimulus, and the sensibility at the same time 

 increased, as explained in Sect. XXXI. 1. and 2. This disposi- 

 tion is communicated to the progeny, and becomes still increas- 

 ed, if the same stimulus be continued, and so on by a third and 

 fourth generation; which accounts for the appearance of epi- 

 lepsy in the children of some families, where it was never known 

 before to have existed, and could not be ascribed to their own 

 intemperance. A parity of reasoning shews, that a few sober 

 generations may gradually in the same manner restore a due de- 

 gree of irritability to the family, and decrease the excess of sensi- 

 bility. 



From hence it would appear probable, that scrofula and dropsy 

 are diseases from inirritability; but that in epilepsy and in- 

 sanity an excess of sensibility is added, and the two faulty tem- 

 peraments are thus conjoined. 



SPECIES. 



1. Mania mutabilis. Mutable madness. Where the patients 

 are liable to mistake ideas of sensation for those from irritation, 

 that is, imaginations for realities, if cured of one source of insa- 

 nity, they are liable in a few months to find another source in some 

 new mistaken or imaginary idea, and to act from this new idea. 

 The idea belongs to delirium, when it is an imaginary or mistaken 

 one; but it is the voluntary actions exerted in consequence of 

 this mistaken idea, which constitute insanity. 



In this disease the patient is liable carefully to conceal the 

 object of his desire or aversion. But a constant inordinate sus- 

 picion of all people, and a carelessness of cleanliness, and of de- 

 cency, are generally concomitants of madness. Their designs 

 cannot be counteracted, till you can investigate the delirious idea 

 or object of their insanity; but as they are generally timid, they 

 are therefore less to be dreaded. 



Z. Z. called a young girl, one of his maid-servants into the 

 parlour, and with cocked pistols in his hands, ordered her to 

 strip herself naked; he then inspected her with some attention, 

 and dismissed her untouched. Then he stripped two of his 

 male servants in the same manner, to the great terror of the 

 neighbourhood. After he was secured, with much difficulty he 



VOL. n. R r 



