460 THEORY OF FEVER. Sep. I. 7. 4, 



rise of the thermometer in both cases continues the same. This 

 fact may be known by boiling an egg in water, the white of 

 which coagulates in much less time, if the water boils vehement- 

 ly, than if it boils moderately, though the sensible heat of the 

 water is the same in both cases. 



Another cause which induces the cutaneous capillaries to re- 

 new their actions sooner than the heart and arteries after immer- 

 sion in the cold bath, is, that their torpor was occasioned by de- 

 fect of irritation: whereas that of the heart and arteries was 

 occasioned by defect of association; which defect of association 

 was owing to the decreased actions of the capillaries, and is now 

 again excited by their renewed action; which excitement must 

 therefore be subsequent to that increased action of the capilla- 

 ries; and in consequence the increased action of the heart and 

 arteries at the commencement of the hot fit of some fevers is sub- 

 sequent to the increased action of the cutaneous capillaries. 

 There is, however, in this case an accumulation of the sensorial 

 power of association in the heart and arteries, which must con- 

 tribute to increase their orgasm in the hot fit, as well as the in- 

 creased excitement of it by the increased action of the capillaries. 

 4. Now this increased action of the system, during the hot fit, 

 by exhausting the sensorial powers of irritation and associa- 

 tion, contributes to induce a renewal of the cold paroxysm; as 

 the accumulation of those sensorial powers in the cold fit pro- 

 duces the increased actions of the hot fit; which two states of 

 the system reciprocally induce each other by a kind of libration, 

 or a plus and minus, of the sensorial powers of irritation and 

 association. 



If the exhaustion of sensorial power during the hot fit of fever 

 only reduces the quantity of irritability and associability to its 

 natural standard, the fever is cured, not being liable to return. 

 If the quantity of these sensorial powers be reduced only so much, 

 as not to produce a second cold fit during the present quantity of 

 external stimuli or influences; yet it may be so far reduced, that 

 a very small subtraction of stimulus, or of influence, may again 

 induce a cold fit; such as the coldness of the night-air; or the 

 diminution of solar or lunar gravitation, as in intermittent 

 fevers. 



5. Another cause of the renovation of the cold fits of fever 

 is from some parts of the system not having completely reco- 

 vered from the former cold paroxysm; as happens to the spleen, 

 liver, or other internal viscus; which sometimes remains tumid, 

 and either occasions a return of the cold fit by direct sympathy 

 with other parts of the body, or by its own want of action causes 

 a diminution of the general quantity of heat, and thus facili* 



