$6 OF STIMULUS Sect. XII. 2. 3, 



dies from the chemical changes, which take place in it ; or it is 

 at a great diftance of time reftored to action by ftimulus appli- 

 ed with great caution in fmall quantity, as happens to fome 

 larger animals and to many infects, which during the winter 

 months lie benumbed with cold, and are faid to fleep, and to 

 perfons apparently drowned, or apparently frozen to death. 

 Snails have" been laid to revive by throwing them into water af- 

 ter having been many years (hut up in the cabinets of the curi- 

 ous •, and eggs and feeds in general are reftored to life after 

 many months of torpor by the ftimulus of warmth and moifture. 



The inflammation of fchirrous tumours, which have long 

 exifted in a ftate of inaction, is a procefs of this kind ; as well 

 as the fenfibility acquired by inflamed tendons and bones, which 

 had at their formation a fimilar fenfibility, which had fo long 

 lain dormant in their uninilamed (late. 



3. If after long quiefcence from defect of ftimulus the fibres, 

 which had previoufly been habituated to perpetual ftimulus, are 

 again expofed to but their ufual quantity of it ; as in thofe who 

 have fuffered the extremes of cold or hunger j a violent exer- 

 tion of the affected organ commences, owing, as above explain- 

 ed, to the great accumulation of fenforial power. This violent 

 exertion not only diminilhes the accumulated fplrit of anima- 

 tion, but at the fame time induces pleafure or pain into the fyf- 

 tem, which, whether it be fucceeded by inflammation or not, 

 becomes an additional ftimulus, and acting along with the for- 

 mer one, produces ftill greater exertions ; and thus reduces the 

 fenforial power in the contracting fibres beneath its natural 

 quantity. ^^ 



When the fpirit of animation is thus exhaufled by ufelefs ex- 

 ertions, the organ becomes torpid or unexcitable into action, and 

 a fecond fit of quiefcence fucceeds that of abundant activity. 

 During this fecond fit of quiefcence the fenforial power be- 

 comes again accumulated, and another fit of exertion follows in 

 train. Thefe viciflitudes of exertion and inertion of the arterial 

 fyftem conftitute the paroxyfms of remittent fevers ; or inter- 

 mittent ones, when there is an interval of the natural action of 

 the arteries between the exacerbations. 



In thefe paroxifms of fevers, which confift of the libration of 

 the arterial fyftem between the extremes of exertion and qui- 

 efcence, either the fits become lefs and lets violent from thexon- 

 tractile fibres becoming lefs excitable to the ftimulus by habit, 

 that is, by becoming accuftomed to it, as explained below XII. 

 3. 1. or the whole fenforial power becomes exhaufted, and the 

 arteries ceafe to beat, and the patient dies in the cold part of 

 the parcxifrn. Or feeondly, fo much pair, is introduced into 



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