1st. Bilious fever is almost always a remittent fever, presenting regular exacerbations, and, unless arrested by medical aid or some effort of nature, running its course, in a progressive manner, either to a happy or fatal termination; whereas the yellow fever is almost invariably a continued fever, presenting obscure and irregular, or even _no_ remissions. On the fourth day, it generally presents so perfect a remission, as to cause the patient, in many cases, to imagine himself perfectly free from disease, and induce him to get up, and even sometimes to walk out. This remission, which sometimes amounts to an intermission, so far as an experience of upwards of forty years can authorize me to decide, is never found to attend in bilious fever, in which, if there be any remission, and recurrence of the unpleasant symptoms, the former is always a real convalescence, and the latter an accidental relapse. 2nd. The red colour of the eye, to which I have alluded above as occurring in the early stage of the yellow fever, and its peculiar yellow tinge in the after part of the disease, are different from the redness and yellowness of the same organ in bilious fever; in the first stage of which the eye presents a more fiery redness, and in the subsequent period, a more saffron yellowness. 3d. The colour of the skin in the two diseases presents also some difference, being more constantly noticed in yellow fever, and disappearing much more rapidly than in bilious fever. In yellow fever, moreover, it assumes, most commonly, a yellowish-brown or even mahogany tinge; whereas in bilious fever, when it occurs, it does not differ from the ordinary jaundice colour, of a lighter or deeper shade. 4th. These fevers may likewise be distinguished by an attention to the state of the intellectual faculties, and of the muscular strength; these remaining often unimpaired to the last in yellow fever, whereas, in a very large majority of cases of bilious fever, the mind becomes soon involved in the disorder of the system, and the greatest muscular debility prevails, even from the very onset of the attack. 5th. The matter vomited might of itself serve to distinguish the two diseases. Independently of the difference we shall notice when speaking of the black vomit, we may mention that patients complain, even sometimes from the commencement of the attack, of the acidity of the vomited matter; whereas in bilious fever, the mouth is bitter, and the matter ejected of the same taste. 6th. As a further mark of difference, we may state, that, in yellow fever, the tongue, except at the tip, the skin, and the pulse are sometimes little altered; whereas in bilious fever they are usually pretty much so.