(for bile acids in urine) in a test tube is placed 2 g of glucose in 15 g of sulfuric acid and the urine is placed on top of this; a purple color forms if bile acids are present. an intracutaneous test in pneumonia for ascertaining the body response to the infection and whether the specific antibodies are present after treatment with antipneumococcus serum. The homologous pneumococcus polysaccharide is used in the skin test.