IF the Blood be too fluid in the Arteries, it is apt to occasion _Anareusms_, and in the capillary Veins an _Ecchymosis_; but nothing is more commonly observed in Practice, that upon a Recovery of the Blood’s due Constitution and Circulation, the obstructed Matter in an _Ecchymosis_ will dissipate through the Pores of the Skin, or be absorbed by the refluent Blood: But when the Blood happens to be too grumous and stagnate, a Fever immediately arises, unless it be prevented by Evacuation; and in such a Disorder every one knows that there is most Danger of a _Schirrus_, or a Mortification. AND as it hath been already observed that Blood could not be drawn from the infected by Phlebotomy, without Loss of Strength, if not of Life, whereas the greater Quantities of _Pus_ were obtained by Suppuration of their Buboes, the Patient was so much the better for it; it seems consonant to Reason, that if _Pus_ was generated immediately from the Blood, the Strength would as much decay upon its Loss, as upon Phlebotomy: But I have always found it, (as many Times already observed) that how little soever the Quantity of Blood drawn away was, and although done at several Times, yet it proved of more Prejudice to the Patient than an hundred times as much Matter drawn from a Buboe; and that the whole remaining Mass was not able to recruit the Loss sustained thereby. IF they who espouse a contrary Opinion, should suggest that Blood may be drawn from a Tumour imperfectly suppurated, and from thence conclude, that its Origin was from the Arterial and Venal Fluids; it may be readily answered, that on opening a fresh Tumour, a bloody _Ichor_ will flow out, because in the Operation some Blood-Vessels will be cut; whereas when the Tumour is in Maturation, the Quantity of Humour there collected obstructs the Blood from flowing to it through its proper Vessels; and which Humour, altho’ in it self at first more thin and crude, yet by the Heat of its neighbouring Parts, and its own natural Disposition, it will afterwards thicken, and change into a white Colour of a laudable Consistence. _THIRDLY_, To the foregoing it may be added, that so far as the Blood partakes of a saline Quality, by so much the less will it be disposed to change into Matter; for the same Reason that Sea-Water cannot be boiled into a Gelly; for Salt adds to the Fluxility of Fluids, and thereby prevents Incrassation, unless in those Instances where they of themselves chrystallize, by Means of an Incapacity of the _Menstruum_ to keep them in Solution, which is foreign to the Case before us.