&SCT. XXXII. 2. DISEASES OF IRRITATI JN. 41 



.cold ft, though Jlrcngtli does not always exijl during 

 the hot fit. 



Thefe fevers arc always connected with, and ge- 

 nerally induced by, ihc disordered irritative motions . 

 of the organs of icnfe, or of the imedinal canal, or 

 of the glandular 1} item, or of the abforbent fyf- 

 tem ; and hence are always complicated with fome 

 or many of thefe difordered motions, which are 

 termed the fymptoms of the fever, and which com- 

 pofe the great variety in thefe difeafcs. 



The irritative fevers both with flrong and with 

 xvcak pulfe, as well as the fcrifitive fevers with ilrong 

 and with weak pulfe, which are to be defcribed in 

 the next fe&ion, are liable to periodical remiflions, 

 and then they take the name of intermittent fevers, 

 and are diilinguifhed by the periodical times of 

 fjigir accefs. 



II. For the better illuflration of the phenomena 

 of irritative fevers we mufl refer the reader to the 

 circumflances of irritation explained in'Sect. XII. 

 and mall .commence this intricate fubjcct by f peak- 

 ing of the quick pulfe, and proceed by confider- 

 ing ingny of the caufes, which either feparately or 

 in combination moll frequently produce the cold 

 fits pf fevers. 



i. If the arteries are dilated but to half their 

 ufual diameters, though they contract twice as fre- 

 quently in a given time, they will circulate only 

 'half their ufual quantity of blood : for as they arc 

 cylinders, the blood which they contain mufl be 

 as the fquares of their diaaieters. Hence when the 

 pulfe becomes quicker and fiiialler in the fame- 

 proportion, the heart and arteries a6t with Ids ener- 

 gy than in their natural flatc. See Seel. XII. i. 4. 



That this quick fmall pulfe is owing to want cf 

 irritability, appears, firft, bccaufc it attends other 

 fymptoms of want of irritability ; and, fecondiy, 

 becaufc on the application of a flimulas gica'e,* 



than 



