an obsolete test for bile in the urine or other body fluid; nitric acid, with a little nitrous acid, is carefully added to a few milliliters of the material to be tested; if bile (bilirubin) is present, it is oxidized to varying degrees, thereby resulting in disclike zones that are (from the interface outward) yellow, red, violet, blue, and green; development of green and violet layers is essential to the validity of the test. SYN: Rosenbach-Gmelin test.