Note 63 — Chapter LII · THE LIVER.

Hanel has shown that a small capillary tube filled with blood, sealed at both ends, may afford a convenient corroborative test. After standing for a few hours in a vertical position its separated serum can be examined against the light. Normal serum is colorless, while even a trace of bile pigment will give it a distinctive yellow tint.

Baudouin’s test for the urine will be the most satisfactory in the matter of precision and simplicity. If two or three drops of a ¹⁄₂ per cent. solution of fuchsin be dropped into urine containing bile it immediately develops a fine orange tint, in marked contrast with its own red. No other coloring matter in the urine gives this reaction; which is very delicate. (Mayo Robson.) Methyl blue and methyl violet each give a reddish tint; Loeffler’s blue solution gives a green tint which vanishes on heating, to reappear on cooling. There are numerous other tests, but these are the simplest and most satisfactory.