Difierent oxidizing substances have been used instead of nitric acid.
2. The iodine test (Smith-Illarechal): When a few drops of tincture of iodine are added to urine containing bile-pig ment an emerald-green color will appear. A watery solution of bromine will pro duce a similar effect.
3. Iluppert's test: A solution of am monia and chloride of calcium is added to the urine. When bilirubin is present a deposit of bilirubin-chalk will be formed, which is filtered and washed down in a test-tube together with strong alcohol containing sulphuric acid. When boiled the liquid takes a blue-green or emerald-green color.
4. Jolies recommends the following method: To 50 cubic centimetres of urine, a drop of hydrochloric acid, chlo ride of barium in excess, and 5 cubic' centimetres of chloroform are added. The mixture is shaken and left standing for 10 minutes, then poured out and the chloroform heated in a water-bath; 3 drops of sulphuretted sulphuric acid con taining one-fourth of its volume of fum ing sulphuric acid are added. The char acteristic rings are found at the bottom of the tube.
5. When only bilirubin is to be re vealed the sulpho-diazo-benzol test of Ehrlich may be of use. The reagent and diluted acetic acid are added to the urine. When the mixture becomes dark, a few drops of glacial acetic acid will bring out the characteristic violet color.
Modification of Ehrlich's test: Three reagents are employed: (1) a 1-per-cent. watery solution of sulphanilic acid, (2) a 1-per-cent. watery solution of nitrite of soda, and (3) pure concentrated hy drochloric acid.
In a test-tube a few drops of the first and second agents are mixed with as much urine; a drop of hydrochloric acid is added and the mixture shaken. It will then, when bilirubin, even if a very small amount, is present, get dark violet. When the liquid is mixed with water the color changes into amethyst-violet. When only a very small quantity of bilirubin is present, the violet color will appear after a few minutes.
This test regarded as the most reliable and delicate of all. Krokiewicz and Batko (Wiener med. Woch., Feb. 24, '98).
The biliary pigments in the urine may decompose by standing, and then the above-mentioned tests will be without re sult. Bilifuscin, which is formed by de composition of the bilirubin, is revealed by moistening white blotting-paper with the urine; the paper will assume a brown color.
TJrobilin is dissolved by chloroform, and the solution takes a greenish fluores cent color upon the addition of iodine and caustic potash. Von Jaksch recom mends the test of Huppert: when urob ilin is present the deposit is red-brown and becomes brown or gray-brown by boiling with sulphuric acid.
Peitenkofer's test: The bile-acids are detected by means of this test, which de pends on the development of a deep purple color when these acids are acted upon by cane-sugar and strong sulphuric acid. This reaction is, however, for sev eral reasons, most unreliable when ap plied to urine, and the bile-acids must be separated from the urine by a compli cated method before the original Petten kofer test can be made.
Strassburger, therefore, has modified the test in the following manner: Cane sugar is added to the urine, and the solu tion is filtered through white filtering paper. After drying the filter a drop of strong sulphuric acid is placed upon it, and after one-half minute a beautiful-red color will appear if bile-acid be present; the color finally changes into a dark purple.
Physiological test for bile in the urine depending upon the fact that the bile salts precipitate the peptones from solu tion. The precipitate produced by urine containing bile-salts in a peptone solu tion acidulated with acetic acid is soluble in acetic or citric acid, thns differing from all other precipitates in the urine produced by acidulated reagents. Fur ther, the precipitate may only be par tially cleared up by heat. Quantitative application of the same principle may also be made. George Oliver ("Bedside Urine-testing," 'S9).
Etiology and Pathology. — Choluria takes place when the constituents of the bile are absorbed by the lymphatics and pass into the blood-vessels, from where they are excreted by the kidneys. It is, therefore, a constant symptom of jaun dice, and is often observed before either the skin or the mucous membranes get stained with bile-pigment. The condi tions which give rise to ieterus will be discussed elsewhere, but by the examina tion of the urine it will never be possible to discover the origin of the jaundice. In some cases the pigment contained in the urine does not seem to be due to absorption of bile in the liver, but to have been formed directly by decomposi tion of the blood-pigments, either while circulating in the blood (hmmatogen ic terns) or after the blood has been ex travasated in the tissues (Quincke's in ogen icterus).
Prognosis and Treatment.—As cho luria is only a symptom of absorption of bile by the blood, its prognosis is in close relation to that of the disease acting as cause. Even if the choluria is very con siderable, it will quickly disappear when the obstacles for the regular flow of the bile are removed. The treatment must also be directed against the fundamental disease, while the symptom, choluria, needs no special treatment.