The duration of the disease is very various, and if neglected may be indefinite. Stephen Mackenzie5 reports a case which lasted twenty-three years.
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 Gull6 and Grainger Stewart, and a hæmatin crystal once by Strong.7
6 Guy's Hosp. Reports, 1866, p. 381.
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, 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.
8 Place a drop of the sediment upon a glass slide and allow it to dry. Mix thoroughly with a few particles of common salt and cover with a thin glass cover, under which allow two or three drops of glacial acetic acid to pass. Carefully warm the slide for a few seconds over a spirit-lamp, and when most of the acetic acid is evaporated, examine by the microscope. Hæmin crystals will be seen to crystallize out as the mixture cools.
In the matter of the presence or absence of blood-discs, it is to be remembered that these may be present at the moment the urine is passed, but disappear by subsequent solution if the urine happens to be alkaline or becomes so secondarily. It is an interesting fact, too, that colorless blood-corpuscles are often present intact, even when red discs are absent. While I have frequently examined urine sent me from the South in which the coloring matter of the blood and no corpuscles were present, only one of the cases coming under my own observations furnished urine of this character. The proportion of urea varies, and bears no evident relation to the condition itself.
PATHOLOGY AND MORBID ANATOMY.—The pathology of malarial hæmaturia consists, as yet, chiefly of theoretical deductions. We can only conclude that the malarial poison acts upon the blood and blood-vessels, impairing the integrity of both. This goes so far occasionally as to produce an actual destruction of blood-discs, and always so alters the capillaries that they permit the transudation of blood-elements ordinarily retained.