48 PROPERTIES OF 



recommended in hemorrhages, excepting in those that are at- 

 tended with evident signs of plethora : but do not these experi- 

 ments show that a vein may be opened with propriety, even 

 where there is no plethora, in order suddenly to bring on weak- 

 ness ; by which the momentum of the blood may be so dimi- 

 nished, and the disposition of the lymph to coagulate may be so 

 increased, as to stop the hemorrhage ? For, when we consider 

 how soon the blood-vessels contract, and adapt themselves to the 

 quantity of blood which they contain, it seems not improbable 

 that in some cases where the hemorrhage is not profuse, but 

 long continued, the strength of the patient may be so recruited, 

 that the disposition to coagulate shall not be sufficiently in- 

 creased, or the extremities of the vessels sufficiently contracted, 

 for the stopping of the bleeding ; but, by emptying the vessels 

 suddenly, this effect may be obtained, and the hemorrhage may 

 be stopped by the loss of less blood than would have happened, 

 had only the slow draining been continued. 



Although the whitish crust so commonly seen in inflam- 

 matory disorders, has so very morbid an aspect, as might in- 

 duce us to consider it as inflammatory, and to bleed repeatedly 

 in all those cases "where it occurs, yet I believe we should act 

 improperly : for, to say nothing of pregnancy, in which the 

 appearance is almost constant, there are few physicians that 

 have not seen patients, who, even in such circumstances, were 

 the worse for this evacuation. Nor need we be surprised that 

 this should happen, considering how soon in some instances 

 this size disappears ; and if so, may we nof suppose, that it may 

 likewise soon be formed, even by a short exertion of strength 

 in the vessels ? Perhaps this was the case in the gentleman 

 mentioned in page 43, who in less than twenty-four hours after 

 bleeding had symptoms of great weakness. 



As it appears from these experiments, that the disposition of 

 the blood to coagulate is increased by bleeding, it may be useful 

 to attend more to this circumstance, and to compare the coagu- 

 lation of the blood in the last with that in the first cup, even in 

 cases that are not attended with the inflammatory crust. And it 

 may likewise be worth while to make the same comparison in 

 those cases where every cup has a crust ; which frequently hap- 

 pens both in rheumatic and in phthisical complaints. By these 



