CLASS IV. 2. 1. 12. OF ASSOCIATION. 407 



tive aflbciation, but not by fenfitive aflbciation. The event was, 

 that as foon as the gums became fore with a flight ptyalifm, the 

 pains about the head and vertigo gradually diminiflied,and during 

 the forenefs of his gums entirely ceafed ; but I believe recurred 

 afterwards, though in lefs degree. 



The idea of inflaming the membranes of the teeth to pro- 

 duce increafed fenfation in them, and thus to prevent their 

 irritative connexion with thofe of the cranium, was taken from 

 the treatment of trifmus, or locked jaw, by endeavouring to in- 

 flame the injured tendon ; which is faid to prevent or to remove 

 the fpafm of the mufcles of the jaw. See Clafs III. i. I. 13. 

 and 15. 



M. M. Emetics. Blifters. Ifiues' about the head. Extrac- 

 tion of decayed teeth.' Slight falivation. Sorbentia. Incitantia. 

 Galvanifm. 



A lady was fuddenly feized with violent vertigo, fo as to pre- 

 vent her from walking fafely acrofs the room, this was attended 

 with confiderable diminution of fight ; and after various evacua- 

 tions, and other medicines, had been tried without cure, Mr. 

 Volta's galvanic pillar was ufed, confiding of about 30 plates of 

 filver, the diameter of about one inch and half, and as many 

 zinc plates, with interpofed circles of cloth moiftened with brine. 

 A wire connected with each end of this pillar was approached 

 repeatedly to her temples, which were previoufly moiftened with 

 brine, and 100 galvanic fhocks were daily patted through the 

 optic nerves, which foon appeared to be of great advantage, and 

 (he foon recovered, both from the vertigo and dimnefs of fight. 

 12. Vertigo ebriofa. Vertigo from intoxicatign is owing to 

 the aflbciation of the irritative ideas of vifion with the irritative 

 motions of the ftomach. Whence when thefe latter become 

 much increafed by the immoderate ftimulus of wine, the irrita- 

 tive motions of the retina are produced with lefs energy by re- 

 verfe fympathy, and become at the fame time fucceeded by fen- 

 fation in confequence of their decreafed action. See Seel. XXI. 

 3. and XXXV. 1.2. So converfely when the irritative mo- 

 tions of vifion are increafed by turning round, or by our unac- 

 cuftomed agitation at fea, thofe of the ftomach become inverted 

 by reverfe fympathy, and are attended in confequence with difa- 

 greeable fenfation. Which decreafed action of the ftomach is 

 in confequence of the increafed expenditure of the fenforial 

 power on the irritative ideas of vifion, as explained in Vertigo 

 rotatoria. 



Whence though a certain quantity of vinous fpirit flimulutes 

 the whole fyftem into increafed action, and perhaps even in- 

 creafes the fecretion of fenforial power in the brain , yet .is foon 



as 



