The characteristics of the urine in alkaptonuria, a condition first described by Boedeker in 1859, are briefly as follows: When voided it has a normal appearance, but rapidly acquires a deep-brown color and ultimately becomes black on exposure to the air. The brown color is greatly intensified by alkalies, its development being accompanied by the absorption of oxygen. The urine reduces Fehling's solution with the aid of heat, the mixture at first being of an inky-black color. It reduces ammoniacal silver-nitrate solutions in the cold. The bismuth test for sugar yields negative results. The urine does not ferment, and it is inactive to polarized rays. Ferric chlorid solution produces a transitory bluish-green color. Linen moistened with the urine turns a deep-brown color on exposure to the air.
The condition is congenital in the vast majority, if not all, of the cases. In a good many cases a history was obtained