Sect. XXXII. 5. i. OF IRRITATION. 291 



is much impaired ; as where the ftomach has been long affected 

 with the gout or fcirrhus ; or in the paralyfis of the liver, as de- 

 fcribed in Sect. XXX. Hence a paroxyfm of gout is liable to 

 recur on bleeding or purging ; as the torpor of fome vifcus, 

 which precedes the inflammation of the foot, is thus induced by 

 the want of the ftimulus of diftention. And hence the extremi- 

 ties of the body, as the nofe and fingers, are more liable to be- 

 come cold, when we have long abftained from food ; and hence 

 the pulfe is increafed both in flrength and velocity above the 

 natural ftandard after a full meal by the ftimulus of diftention. 



However, this ftimulus of diftention, like the ftimulus of heat 

 above defcribed, though it contributes much to the due action 

 not only of the heart, arteries, and alimentary canal, but feems 

 neceflary to the proper fecretion of all the various glands ; yet 

 perhaps it is not the fole caufe of any of thefe numerous mo- 

 tions : for as the la£leals, cutaneous abforbents, and the various 

 glands appear to be ftimulated into action by the peculiar pun- 

 gency of the fluids they abforb, fo in the inteftinal canal the 

 pungency of the digefting aliment, or the acrimony of the feces, 

 feems to contribute, as well as their bulk, to promote the perif- 

 taltic motions ; and in the arterial fyftem, the momentum of the 

 particles of the circulating blood, and their acrimony, ftimulate 

 the arteries, as well as the diftention occafioned by it. Where 

 the pulfe is fmall this defect of diftention is prefent^ and con- 

 tributes much to produce the febris irritativa pulfu debili, or ir- 

 ritative fever with weak pulfe, called by modern writers nervous 

 fever, as a predifponent caufe. See Sect. XII. 1. 4. Might 

 not the transfufion of blood, fuppofe of four ounces daily from 

 a ftrong man, or other healthful animal, as a (beep or an afs, be 

 ufed in the early ftate of nervous or putrid fevers with great 

 profpect of fuccefs ? 



V. The defect of the momentum of the particles of the circu- 

 lating blood is another caufe of the quiefcence, with which the 

 ■ cold fits of fever commence. This ftimulus of the momentum 

 of the progreflive particles of the blood does not act over the 

 whole body like thofe of heat and diftention above defcribed, 

 but is confined to the arterial fyftem 5 and differs from the 

 ftimulus of the diftention of the blood, as much as the vibra- 

 tion of the air does from the currents of it. Thus are the dif- 

 ferent organs of our bodies ftimulated by four different mechan- 

 ic properties of the external world : the fenfe of touch by the 

 preflure of folid bodies fo as to diftinguifh their figure ; the 

 mufcular fyftem by the diftention, which they occafion ; the in- 

 ternal furface of the arteries, by the momentum of their moving 

 particles 5 and the auditory nerves, by the vibration of them : 



and 



