Page:Tropical Diseases.djvu/83

III] cold stage occupying about an hour, the hot stage from three to four hours, the sweating stage from two to four hours. The urine in ague.—— During the cold stage the urine is often limpid and abundant, and is passed frequently; but during the hot and sweating stages it is scanty, loaded, sometimes albuminous. The amount of urea is increased, particularly during the cold stage; and so are the chlorides and sulphates. The phosphates, on the contrary, diminished during the rigor and hot stages, are increased during defervescence. The augmentation in the excretion of urea commences several hours before the subjective symptoms of the attack begin, attains its maximum towards the end of rigor, and decreases during the hot and sweating stages, although still continuing above the normal standard. The excretion of carbonic acid follows a corresponding course. Sydney Ringer was the first to point out the interesting fact that, although the return of fever may be prevented by the administration of quinine, yet, for a time, a periodic increase in the excretion of urea occurs on the days on which the fever fit was due. The urine is often deeply coloured, giving with nitric acid the play of colour characteristic of bile pigment, or the brown colour described by Grübler as " hæmapheic." Glycosuria does occur, but is by no means common.

The spleen during the fit.—— The spleen becomes enlarged to a greater or less extent during rigor. At first the swelling disappears in the interval, but it tends to become more or less of a chronic feature if the attacks recur frequently, more especially if they are associated with pronounced cachexia. Period of the day at which ague commences.——Two-thirds of agues come off between midnight and midday. This is a fact to remember in diagnosis; especially when we have to face the possibility of recurrent pyrexial attacks being dependent on such conditions as liver abscess, tuberculosis, and septic states conditions, be it remarked, in which febrile recurrence takes place almost invariably during the afternoon or evening.