The plague, as has already mentioned, in its very severe state appears most commonly in the beginning of an epidemic season, and is neither very common nor very infectious. The most common mode in which it invades the patient is with the symptoms of a malignant fever; and of cases of this kind Dr. Russel has made up his five classes of patients, the first or deadly kind having been already described. In his second class, the next in malignity to the fatal kind, the disease made its attack with a slight shivering, succeeded by fever with giddiness, vomiting, head-ach, and sometimes looseness. In the night the fever increased, the thirst was excessive, and the patient, harassed by the vomiting, &c. passed a very unquiet night, frequently with delirium or coma. Towards morning the fever abated, the sick recovered their senses if delirium had taken place, but if coma, it continued through the day, and the remissions were less. Throughout the first day, and part of the second, the pulse was full and strong, but on the second it began to alter, and some of the characteristic signs of the disease to appear. The principal of these was a certain muddiness in the eyes, which sometimes took place even on the first day. This is by our author accounted a symptom very difficult to be described, and, though he recounts the descriptions given by several authors, none are found adequate to the real appearance. “It resembled (says he) somewhat the dull, fixed eye observable in the last stage of malignant fevers; but the dullness was different, muddiness and lustre being strangely blended together. It continued with little alteration in the remissions, and even where the patient appeared sensible and composed it did not increase in the febrile exacerbations, but the eyes acquired a redness that added wildness to the look, which abating or going off in the remissions, the muddiness remained behind. It was this which contributed chiefly in composing that confusion of countenance which I shall not attempt to describe, but which enabled me to pronounce with tolerable certainty whether the disease was or was not the plague, though not independently of other symptoms. When this muddiness disappeared or abated, it was constantly a favourable sign. After a critical sign it often disappeared suddenly, but where there was a succession of sweats, or where no visible crisis happened, its disappearance was slow and gradual.”