602 PRACTICE OF PHYSIC. 



generating heat in the body is increased, the surrounding tem- 

 perature ought to be somewhat lowered, in order to prevent a 

 pernicious increase of heat. We shall afterwards consider to 

 what degree external cold may in this case be applied ; but 

 when the reaction of the system has continued for some time, 

 and when the hot fit is fully formed, the cold, which would have 

 been pernicious at an earlier period, may now be a salutary, and 

 even a necessary remedy. 



" It is to be observed, that the temperature of the air sur- 

 rounding the body may be increased from various causes ; and, 

 moreover, the air remaining the same, that portion of it which is 

 applied to the body, by remaining upon its surface, may accumu- 

 late the heat. The effects of the generating power, therefore, are 

 different in proportion to the clothes which confine the heat 

 produced by it, and in proportion to their being more or less 

 proper for transmitting the heat to the external air. A gar- 

 ment, for instance, of linen, which transmits heat more readi- 

 ly, will not preserve the heat as well as the same weight of 

 woollen. The covering, however, being given, the effects will 

 be greater or less, as the effluvia from the body are more or less 

 confined as the effluvia are closed up, and the vapour not 

 allowed to escape ; or as, on the other hand, the clothes lie loose, 

 and allow the heat and vapour to escape. Here, even the hand 

 laid out, affords a spiraculum or outlet to the heat, which would 

 otherwise be accumulated. 



" There are two cases, however, which appear to be excep- 

 tions to this rule of avoiding external heat. The first of these 

 is the application of remedies, which we shall mention hereafter, 

 viz. warm bathing and warm fomentations ; but such applica- 

 tions are allowable, because they are so conducted that they act 

 more powerfully by relaxing the whole of the system, and by 

 determining to the surface, than by heating the body. The 

 other case happens when the determination to the surface, which 

 is necessary for the solution of the fever, is already excited by the 

 vis medicatrix natura?, and where the flowing of jthe cutaneous 

 secretion is to be supported by the application of warmth." 



2. All motion of the body is to be avoided, especially that 

 which requires the exercise of its own muscles ; and that posture 

 of the body is to be chosen which employs the fewest muscles, 



