Chemistry of urine : a practical guide to the analytical examination of diabetic albuminous, and gouty urine / Alfred H. Allen.
- Alfred Henry Allen
- Date:
- 1895
Licence: Public Domain Mark
Credit: Chemistry of urine : a practical guide to the analytical examination of diabetic albuminous, and gouty urine / Alfred H. Allen. Source: Wellcome Collection.
212/250 page 194
![products of its oxidation, lii bilious urine of saflfron- yellow colour bilirubin predominates, while biliverdin and other oxidation-products are present in greenish urine. Bilious urine gives a yellow frotli on agitation, and stains linen and filter-paper yellow.' Bilirubin may be extracted from its acidulated solutions l)y agitation with chloroform. It dissolves in caustic alkalies, and on exposing the solution to the air it is converted into biliverdin, C,bH,sN204 ; subsequently into b i 1 i p r a s i n, C„!H22N20e; and, according to M a 1 y, ultimately into choletilin, CibHirNsOb. A variety of tests have been proposed for the detection of bile-pigments in urine, but the following are the most delicate and answer every purpose :— Gmelms Test consists in treating the urine with strong nitric acid and observing the change of colour produced. The reaction is best observed by allowing some of the urine to run gently onto the surface of some fuming: nitric acid contained in a test-tube. If bile-pigments be present, a green ring will become apparent at the point of contact, while below this will appear violet, red, and yellow zones, in the order named. The green colour is alone characteristic of bilious urine, since indigogens give rise to blue and red colorations. Various modifications of Gmelin’s reaction have been proposed, but they possess no advantage over the above mode of applying the test. Rosin’s Test for bile-pigments consists in allowing very dilute iodine solution or bromine-water to flow on to the surface of the urine from a pipette. A grass-green ring is produced at the junction of the two strata. 1 If the dyed filter-paper be treated with a drop of nitric acid, the margin of the spot will become violet or dee]i blue, while the centre gradually changes to emerald-green.](https://iiif.wellcomecollection.org/image/b28138818_0212.jp2/full/800%2C/0/default.jpg)
