Sec. 252. The first Attack of an intermittent Fever often happens, when the Patient thought himself in perfect Health. Sometimes however it is preceded by a Sensation of Cold and a kind of Numbness, which continue some Days before the manifest Invasion of the Fit. It begins with frequent Yawnings, a Lassitude, or Sensation of Weariness, with a general Weakness, with Coldness, Shivering and Shaking: There is also a Paleness of the extreme Parts of the Body, attended with Loathings, and sometimes an actual Vomiting. The Pulse is quick, weak, and small, and there is a considerable Degree of Thirst. At the End of an Hour or two, and but seldom so long as three or four Hours, a Heat succeeds, which increases insensibly, and becomes violent at its Height. At this Period the whole Body grows red, the Anxiety of the Patient abates; the Pulse is very strong and large, and his Thirst proves excessive. He complains of a violent Head-ach, and of a Pain in all his Limbs, but of a different sort of Pain from that he was sensible of, while his Coldness continued. Finally, having endured this hot State, four, five or six Hours, he falls into a general Sweat for a few more: upon which all the Symptoms already mentioned abate, and sometimes Sleep supervenes. At the Conclusion of this Nap the Patient often wakes without any sensible Fever; complaining only of Lassitude and Weakness. Sometimes his Pulse returns entirely to its natural State between the two Fits; though it often continues a little quicker than in perfect Health; and does not recover its first Distinctness and Slowness, till some Days after the last Fit. One Symptom, which most particularly characterises these several Species of intermitting Fevers, is the Quality of the Urines which the Sick pass after the Fit. They are of a reddish Colour, and let fall a Sediment, or Settling, which exactly resembles Brick-dust. They are sometimes frothy too, and a Pellicle, or thin filmy Skin, appears on the Top, and adheres to the Sides of the Glass that contains them. Sec. 253. The Duration of each Fit is of no fixed Time or Extent, being various according to the particular sort of Intermittents, and through many other Circumstances. Sometimes they return precisely at the very same Hour; at other Times they come one, two, or three Hours sooner, and in other Instances as much later than the former. It has been imagined that those Fevers, whose Paroxysms returned sooner than usual, were sooner finally terminated: but there seems to be no general Rule in this Case.