5 io THEORY OF FEVER. Suf. I. 16. 10. 



pulfe from the ftrong one, it may generally be aflifted by count- 

 ing its frequency. For when an adult patient lies horizontally 

 in a cool room, and is not hurried or alarmed by the approach of 

 his phyfician, nor flimulated by wine or opium, the ftrong pulfe 

 feldoms exceeds 1 18 or 120 in a minute ; and the weak pulfe 

 is generally not much below 130, and often much above that 

 number ; except where a patient has naturally a pulfe flower 

 than ufual in his healthy ftate. Secondly in fitting up in bed, 

 or changing the horizontal to a perpendicular pofture, the quick- 

 nefs of the weak pulfe is liable immediately to increafe 10 or 

 20 pulfations in a minute, which does not 1 believe occur in the 

 ftrong pulfe, when the patient has refted himfelf after the exer- 

 tion of rifing. 



I fhall here infert a remark on the general ufe of ftimulating 

 materials, whether medicinal or culinary, to counteract or pre- 

 vent debility. When a ftimulating material is exhibited, as the 

 Peruvian bark, or opium, or wine 5 it ffiould be continued but 

 a certain time, as half a lunation, or a whole lunation. If the 

 whole fyflem be ftimulated into increafed exertion, as by wine 

 or opium, there appears to be a temporary increafed fecretion of 

 fenforial power in the brain, fo long as this ftimulus affects the 

 fyftem. If a part only of the fyftem be ftimulated, as by the 

 exhibition of fpices, eflential oils, or bitter medicines, or metal- 

 lic ones, then the ftimulated organ has derived to it a greater 

 quantity of fenforial power, or a greater fecretion of it is pro- 

 duced in that part of the brain, where the ftimulated nerves 

 arife. Which is probably owing to the fympathy of the ftimu- 

 lated extremity of every nerve, or its organ of fenfe, with the 

 other extremity of it in the brain, in the fame manner as when 

 the excretory duel: of a gland is ftimulated, a greater fecretion 

 is produced in the body of it, as when the duels of the lacrymal 

 glands in the eyes, or of the falivary glands in the mouth are 

 ftimulated by duft or acrid materials. 



Now if a ftimulating medicine be given at certain intervals of 

 time, as the Peruvian bark or wine in fevers, the increafed ac- 

 tion of a part or of the whole fyftem foon becomes a link of 

 the aflbciated circle of diurnal actions, and may be faid to be- 

 come habitual. 



The quantity of the ftimulating medicine may then be dimin- 

 ifhed, and yet the increafed activity of the fyftem will continue ; 

 becaufe the increafed exertions are now produced partly by the 

 fenforial power of alfociation, as they are become a part of the 

 diurnal circle of aftions. And finally the ftimulating medicine 

 may be totally omitted, and yet the increafed activity of the fyf- 

 tem continue for the fame reafon. 



On 



