While a majority of cases of malarial hæmaturia are intermittent, many are continuous, and of my eight cases only three were distinctly intermittent. One of these cases I published in a clinical lecture in the _Philadelphia Medical Times_ as far back as September 1, 1871. Negroes are not exempt from this milder form of the disease, as they seem to be from the more malignant form of the South. While writing this paper I was consulted by a negro thirty-one years old who had a true malarial hæmoglobinuria, which yielded promptly to the treatment by quinine. But this was the only negro out of seven cases. The duration of the disease is very various, and if neglected may be indefinite. Stephen Mackenzie[5] reports a case which lasted twenty-three years. [Footnote 5: "On Paroxysmal Hæmoglobinuria," _London Lancet_, vol. i., 1884, p. 156.] PHYSICAL AND CHEMICAL CHARACTERS OF THE URINE.--The urine is usually acid in reaction when passed, sometimes neutral, rarely alkaline, and ranges in specific gravity from 1010 to 1028. It is always albuminous, and always tinged by blood coloring matters, the depth of color varying from the trifling degree known as smoke-hued to a dark-red or claret color. Sometimes it is even darker, and is often compared to porter, though this degree of coloration is more characteristic of the malignant form. The urine deposits a dark, reddish-brown sediment, generally copious, but varies in quantity with the degree of coloration of the urine. This sediment is made up chiefly of red blood-discs or the granular débris resulting from their disintegration. Casts of the uriniferous tubules are also often present. They are usually made up of aggregated red blood-discs or the granular matter referred to; but they may also be hyaline or hyaline with a moderate amount of granular matter attached. Granular urates also at times contribute to the sediment and also adhere to the casts. Renal and vesical epithelium may occur. Crystals of oxalate of lime and of uric acid are sometimes present, while blood-crystals have been found by Gull[6] and Grainger Stewart, and a hæmatin crystal once by Strong.[7] [Footnote 6: _Guy's Hosp. Reports_, 1866, p. 381.] [Footnote 7: _British Med. Journ._, 1878, vol. ii. p. 103.] That red blood-discs are at times exceedingly scarce, and even totally absent at the very moment when urine is passed, is a well-recognized fact; while that the coloring matter present is still that of the blood, {109} even though no corpuscles are present, is easy of demonstration by the production of Teichmann's hæmin crystals,[8] by spectrum analysis, or by the guaiacum test.