FEVERS. 551 



effects are not more remarkable ; and this wonder can only be 

 taken off by considering that the effluvia are frequently not ac- 

 cumulated in sufficient quantity to operate by themselves, but 

 are ready to operate with the concurrence of other causes, so 

 that proper fever then is hardly to be imputed to the sole ope- 

 ration of cold, but it is probably owing to miasma or contagion, 

 even when it appears affecting a single person only. Agree- 

 ably to this you will observe that the poor people are more sub- 

 ject to fevers, and in Epidemics are always sooner affected than 

 those of the higher ranks. 



" But although we deny that cold is the proper cause of feve^ 

 we must allow that it is one of the most general exciting causes, 

 and that it has a great share in modifying and determining the fever 

 to be more or less of the inflammatory kind. Thus Dr. Willis, 

 one of the earliest writers in England upon the nervous fever 

 (1661), observes that, in certain cases, the fever took a deter- 

 mination to the breast, and produced cough and other catarrhal 

 affections ; which only amounts to this, that cold may mix itself 

 with every disease so as to produce these effects. It is owing 

 to the power of cold that so many fevers are in their begin- 

 ning seemingly of this nature, and that Synochus is so frequent, 

 more especially in cold climates and cold seasons ; and it is in 

 consequence of this that fevers are more frequently of the con- 

 tinued kind here. So much with regard to the important con- 

 sideration of the share which cold has either in producing or in 

 modifying the forms of fever." 



XCIII. Cold is often applied to the human body without 

 producing any of these morbid effects, and it is difficult to de- 

 termine in what circumstances it especially operates in produ- 

 cing them. It appears to me, that the morbid effects of cold 

 depend partly upon certain circumstances of the cold itself, and 

 partly on certain circumstances of the person to whom it is ap- 

 plied. 



XCIV. The circumstances of the cold applied, which seem 

 to give it effect, are, 1. The intensity or degree of the cold ; 

 2. The length of time during which it is applied ; 3. The de- 

 gree of moisture at the same time accompanying it ; 4. Its 

 being applied by a wind or current of air ; 5. Its being a vicis- 



