610 PRACTICE OF PHYSIC. 



about the propriety of blood-letting ; but there are other species 

 of fever, as the synochus, in which a violent reaction and phlo- 

 gistic diathesis appear, and prevail during some part of the 

 course of the disease ; while, at the same time, these circum- 

 stances do not constitute the principal part of the disease, nor 

 are to be expected to continue during the whole course of it ; 

 and it is well known, that, in many cases, the state of violent 

 reaction is to be succeeded, sooner or later, by a state of debi- 

 lity, from the excess of which the danger of the disease is chiefly 

 to arise. It is, therefore, necessary, that, in many cases, blood- 

 letting should be avoided ; and even though it may be proper 

 during the inflammatory state of the disease, it will be ne- 

 cessary to take care that the evacuation be not so large as to 

 increase the state of debility which is to follow. 



CXLII. From all this it must appear, that the employing 

 blood-letting, in certain fevers, requires much discernment and 

 skill, and is to be governed by the consideration of the following 

 circumstances : 



1. The nature of the prevailing epidemic. " If we know 

 that a contagion prevails which forms a fever of a particular 

 character, suppose that which we call of the nervous kind or 

 typhus, then, even if it first appears like a synocha, I have less 

 regard to the inflammatory symptoms, though they be strongly 

 marked ; as I know that they may soon disappear and be suc- 

 ceeded by the symptoms of debility. Sir John Pringle found, 

 that one bleeding in the beginning of the jail fever was safe and 

 attended with advantage ; but the repetition certainly was ex- 

 tremely dangerous. Our knowledge, therefore, of the nature 

 and tendency of the prevailing epidemic will determine our prac- 

 tice in bleeding." 



2. The nature of the remote cause. " When we know of 

 no contagious fever prevailing, and have direct evidence of the 

 operation of cold, bleeding is the proper remedy ; but where a 

 contagion is present, it is to be employed with caution." 



3. The season and climate in which the disease occurs. 

 " The inhabitants of northern climates sustain bleeding better 

 than those of the southern ; even those who are exposed to very 

 cold winters, if they are also exposed to the vicissitude of very 

 warm summers, do not bear bleeding so well as those who have 



