SECT. XII. OF STIMULUS, &c. 43 



SECT. XII. 



OF STIMULUS, SENSORIAL EXERTION, AND FIBROUS CONTRAC- 

 TION. 



I. Of fibrous contraction. I. Two particles of a fibre cannot 

 approach without the intervention of fomething, as in magnet ifm, 

 elecJricity, elajlicity. Spirit of life is not eleclric ether. Galvanfs 

 experiments. 2. Contraction of a fibre. 3. Relaxation fuc- 

 ceeds. 4. SucceJJive contractions^ 'with intervals. hnck pulfe 

 from debility, from paucity of blood. Weak contraElions perform- 

 ed in lefs time, and with JJjorter intervals. 5 . Laft fitua- 

 tion of the fibres continues after contraction. 6. Contraction 

 greater than ufual induces pleafure or pain. 7. Mobility of the 

 fibres uniform. Quantity of fenforial power fluBuates. Conjli- 

 tutes excitability. II. Of fenibrial exertion. i. Animal motion 

 includes fiimulus, fenforial pow er, and contractile fibres. *The fen- 

 forial faculties aft feparately or conjointly. Stimulus of four kinds. 

 Strength and weaknefs defined. Senforial power perpetually ex- 

 haujled and renewed. Weaknefs from defecJ ofjiimulus. From 

 defecl of fenforial power, the direCt and indirecl debility of Dr. 

 Brown. Why we become warm in Buxton bath after a time, and 

 fee well after a time in a darkijjj room. Fibres may aCt violently, 

 or with their whole force , and yet feebly. Great exertion in in- 

 flammation explained Great mufcular force of fome infane peo- 

 ple. 2. Occafional accumulation of fenforial power in mufclesfub- 

 jeCt to conjlcintjlimulus. In animals flee ping in 'winter. In eggs, 

 feeds y f chirr hous tumours, tendons, bones. 3. Great exertion in- 

 troduces pleafure or pain. Inflammation. Libration of the fyf- 

 tem between torpor and aCtivity. Fever- fits. 4. Defire and a- 

 verfion introduced. Excefs of volition cures fevers. III. Of re- 

 peated dim ulus. J. A jlitnulus repeated too frequently lofes ef- 

 feCt. As opium, wine, grief. Hence old age. Opium and aloes 

 in fmall dofes - 2. AJlimulusnot repeated infrequently does not 

 lofe effecJ. Perpetual movement of the vital organs. 3. A Jlim- 

 ulus repeated at uniform times produces greater fjfeft. Irrita- 

 tion combined 'with ajfociation. 4. A flimulus repeated frequent- 

 ly and uniformly may be withdrawn, and the aclion of the organ 

 will continue. Hence the bark cures agues, andflrengthens weak 

 coujlitutions. 5, Defecl of Jlimulus repeated at certain intervals 

 amfes fever-fits. 6. Stimulus hng applied ceafes to ccl a ft: con d 

 time. 7 If aflimulus excites fetifation in an organ not ujually 

 'tidintofenfatton, inflammation is produced. IV. Of ftimu- 

 ' \'-\ than natural, i. A Jlimulus grenter than natural 



di minifies* 



