SECT. XII. 3. OF STIMULUS AND EXEP TION. S 9 



though the irritative motions in confcquence of 

 it may continue or be re-excited. 



Many catenations of irritative motions were at 

 firil fucceeded by fenfation, as the apparent motions 

 of objects when we walk pad them, and probably 

 the vital motions themfelves in the early ftate of 

 our exiftence. But as thofe fenfations were fol- 

 lowed by no movements of the fyftem in confe- 

 quence of them, they gradually ceafed to be pro- 

 duced, not being joined to any fucceeding link of 

 catenation. Hence contagious matter, which has 

 for fome weeks ilimulated the fyftem into great and 

 permanent fenfation, ceafes afterwards to produce 

 general fenfation or inflammation, though it may 

 ilill induce topical irritations. See Sect. XXXIII. 2. 

 8. XIX. 10. 



Our abforbent fyitem then feems to receive thofe 

 contagious matters, which it has before experi- 

 enced, in the fame manner as it imbibes commoa 

 moifture or other fluids ; that is, without being 

 thrown into fo violent action as to produce fenfa- 

 tion ; the confequence of which is an increafe of 

 daily energy or activity, till inflammation and its 

 confequences fucceed. 



7. If a ftimulus excites an organ into fuch vio- 

 lent contractions as to produce fenfation, the mo- 

 tions of which organ had not ufually produced fen- 

 fation, this new fenforial power, added to the ir- 

 ritation occafioned by the ftimulus, increafes the 

 activity of the organ. And if this activity be ca- 

 tenated with the diurnal circle of actions, an in- 

 creafing inflammation is produced ; as in the even- 

 ing paroxyfms of fmall-pox, and other fevers with 

 inflammation. And hence fchirrous tumours, ten- 

 dons and membranes, and probably the arteries 

 themfelves become inflamed, when they are itrong, 

 ly Simulated. 



IV. Of 



