CLASS III. 1. 1. 8. OF VOLITION. 287 



verie or fomnambulation. About half an hour before the ex- 

 pelled return of the fit three or four grains of opium were ex- 

 hibited, and then tincture of opium was given in warm brandy 

 and water about twenty or thirty drops every half hour, till the 

 eyes becarre fomewhat inflamed, and the nofe began to itch, 

 and by the {harp movements of the patient, or quick fpeech, an 

 evident intoxication appeared ; and then it generally happened 

 that the pain ceafed. But the effects of this large dofe of opium 

 was fucceeded by perpetual ficknefs and efforts to vomit, with 

 great general debility all the fucceeding day. 



The rationale of this temporary cure from the exhibition of 

 opium and vinous fpirit depends on the great expenditure of 

 fenforial power in the increafed actions of all the irritative mo- 

 tions, by the ftimulus of fuch large quantities of opium and vi- 

 nous fpirit ; together with the production of much fenfation, 

 and many movements of the organs of fenfe or ideas in confe- 

 quence of that fenfation ; and laftly, even the motions of the 

 arterial fyftem become accelerated by this degree of intoxica- 

 tion, all which foon exhaufted fo much fenforial power as to re- 

 lieve the pain ; which would otherwife have caufed convuiiions 

 or infanity, which are other means of expending fenforial pow- 

 er. The general debility on the fucceeding day, and the partic- 

 ular debility of the ftomach, attended in confequence with fick- 

 nefs and frequent efforts to vomit, were occafioned by the fyf- 

 tem having previoufly been fo flrongly ftimulated, and thofe 

 parts in particular on which the opium and wine more imme- 

 diately a&ed. This ficknefs continued fo many hours as to 

 break the catenation of motions, which had daily reproduced 

 the paroxyfm ; and thus it generally happened, that the whole 

 difeafe ceafed for fome weeks or months from one great intoxi- 

 cation, a circumftance not eafily to be explained on any other 

 thoiry. 



Ths excefs or defect: of motion in any part of the fyftem oc- 

 cafions the production of pain in that part, as in Seel:. XII. i . 6'. 

 This defect: or excefs of fibrous action is generally induced by 

 excefs or defect, of the ftimulus of objefts external to the mov- 

 ing organ. But there is another fource of excelfive fibrous ac- 

 tion, and confequent pain, which is from excefs of volition, 

 which is liable to affect thofe mufcles, that have weak antago- 

 rufts ; as thofe which fupport the under jaw, and clofe the mouth 

 in biting, and thofe of the calf of the leg ; which are thus liable 

 to fixed or painful contractions, as in trifmus, or locked jaw, and 

 in the cramp of the calf of the leg ; and perhaps in fome colics, 

 as in that of Japan : thefe pains, from contraction arifing from 

 excefs of volition in the part from the want of the counteraction 



