10th. The prognosis. The danger was generally in proportion to the degree of affection of the head, irritability of the stomach, and yellowness of the skin, and as these appeared early or not. 11th. In the treatment various modes were tried. Emetics appeared to be unnecessary; and, in general, seemed to do mischief, as did all antimonials. I have witnessed the practice of a large hospital, where blood-letting was premised in every case; but this was by no means a successful practice. In three cases in the Betsy, and where the state of the pulse and other symptoms seemed particularly to call for it, I performed venæsection; but I lost my three patients. Clearing the bowels appeared to be a principal indication: when this was repeatedly done by drastic purgatives, and when a free perspiration was kept up, there was always less complaint of the head, and, in some cases, a remission was thus obtained, and the bark could then be given with manifest advantage. In the few cases where it was used to produce salivation, calomel did more good than any other remedy whatever. I lost no case, where I succeeded in inducing a flow of saliva. In some cases, and these all proved fatal, the gums became insensible to the effects of mercury; and though one drachm of calomel in one case, and two scruples in another, were given in a very short period, yet the patient died without a flow of saliva having been excited. Nothing gave more relief than the cold bath; it generally suppressed the irritability of stomach for some time; it always induced sleep, and brought out a gentle sweat, which most commonly relieved the patient. The Brunonian practice I saw tried with no advantage. These are the principal of the leading circumstances, regarding the yellow fever, which came immediately under my notice. Dr Chisholm, when he formed the opinion of the similarity of the plague and the yellow fever, was not singular. Since my arrival in England, I have received several letters addressed to me in Egypt, and which followed me from that country to India, and from thence to Europe; mostly answers to letters which I wrote from Egypt. By two of my West-India correspondents, in particular, this opinion is repeatedly expressed. I have several letters on the subject from two most respectable physicians, Dr Paterson, of Grenada, and Dr Robertson, of Barbadoes. From the opinion which he had formed, Dr Paterson repeatedly urges me to the use of mercury, and of the cold bath, in the plague.