[1] Dr. _Huxham_, in his _Treatise on the ulcerous sore Throat_, p. 36, says, “I have very often met with this buffy or sizy Appearance of the Blood in the Beginning of Malignant Fevers; and yet, Blood drawn two or three Days afterwards, from the same Persons, hath been quite loose, dissolved, and sanious as it were.” And in his _Essay on Fevers_, chap. viii. p. 108. says, “The first Blood frequently appears florid; what is drawn twenty four Hours after, is commonly livid, black, and too thin; a third quantity, livid, dissolved, and sanious. I have sometimes observed the Crasis of the Blood so broke as to deposite a black Powder, like Soot, at the Bottom, the superior Part being either a livid Gore, or a dark green, and exceedingly soft Jelly.” The Reason of this Difference of Symptoms in the Beginning, and of these different Appearances of the Blood, seemed to be, that such Patients as laboured under Pleurisies, low or other Fevers, being brought into Hospitals where the Malignant Fever was frequent, had their original Disorders changed into this Fever by breathing a foul infected Air, and by their Communication with those ill of the Fever, and of Fluxes; at other Times, a mere Acrimony of the Blood, set in Motion by a supervening Fever, determined the Disorder to be of this kind: and I always observed, that those Men were most apt to catch this Fever, whose Constitutions had been broke down by previous Disorders. The Fever appeared in different Forms. Some had only a Quickness of the Pulse, attended with a slight Head-ach and Sickness, Whiteness of the Tongue and Thirst, and a Lowness and Languor; which continued for a Week or more, and then went off, either insensibly, or with a profuse Sweat, succeeded by a plentiful Sediment in the Urine. Most of those who fell into profuse kindly-warm Sweats recovered, the Sweat carrying off the Fever. These profuse Sweats continued for twelve or twenty-four Hours, and sometimes for two, three, or four Days. In those who had the Fever in this slight Degree, the Petechiæ seldom appeared; and it was only known to be this sort of Fever by the other Symptoms, and the Malignant Fever being frequent at that time in the Hospitals. Dr. _Pringle_[2] very justly observes, “That these low Degrees of this Fever are hardly to be characterised, and are only to be discovered, in full Hospitals, by observing Men languish; though the Nature of the Illness, for which they come in, should seem to admit of a speedier Cure.” [2] _Observations on the Diseases of the Army_, part III. chap. vii. sect. 3. third Edition, 1761. For the most Part the Fever appeared with more violent Symptoms, the Tongue became more parched and dry, more or less of a Delirium came on, attended with the other Symptoms commonly described as peculiar to this Fever.