xxil] blood, bile, and sugar in urine. 141 



3. Bile in Urine. — The biliary constituents appear in the urine 

 in cases of jaundice and in poisoning with phosphorus. One may 

 test for the bile-pigments, or the hile-aci<U, or both. 



A. Bile-Pigments. 



{a.) Colour. — The urine has usually a yellow or yellowish- green 

 colour, and it froths very easily when shaken. Filter-paper dipped 

 into it gives a yellow stain on drying. 



{h.) Gmelin's Test (Nitric acid containing Nitrous acid). — (r.) 

 Place a few drops of the suspected urine on a wliite porcelain plate, 

 and near it a few drops of the impure nitric acid ; let the fluids run 

 together and the usual play of colours is observed (Lesson XI. 6). 

 (2.) Take urine in a test-tube, pour in the imjiure HXO3 until it 

 forms a stratum at the bottom ; if bile-pigments be present, at the 

 line of junction of the fluids a play of colours takes place — from 

 above downwards — green, blue, violet or dirty red, and yellow. 

 Nearly all urines give a play of colours, but (jreen is the necessary 

 and characteristic colour to prove the presence of bile-pigments. 

 (3.) Rosenbach's Modification.— Filter the urine several times 

 through the same filter, dry the filter-paper, and to it apply tlie 

 impure nitric acid, when the same play of colours is observed. 



(c.) A solution of methyl-violet poured on icteric urine by the contact 

 method gives a bright carmine ring at the point of contact. 



{d.) If much bile-pigment be present, the following test succeeds :— Mix 

 the urine with caustic potash ( i KHO to 3 water), and add hydrochloric acid. 

 The fluid becomes green, due to the formation of biliverdin. 



B. Bile-Acids (Glycocholic and Taurocholic acids). 



(a.) Pettenkofer's Test.— Add to urine a few drops of syrup of 

 cane-sugar (8 per cent.), mix them, and pour strong sulphuric acid 

 down the side of the tube until it forms a layer at the bottom. 

 The temperature must not rise above 70'' C, nor must the urine 

 contain albumin. At the line of junction a cherrij-red or purplc- 

 viold colour indicates the presence of the bile-acids. Or proceed 

 as follows : — Shake the tube with the urine and the syrup to get a 

 froth, and when the sulphuric acid is added the froth shows the 

 colour. N.B. — The test in this simple form often fails with urine, 

 and in fact there is no satisfactory simple test for minute quantities 

 of these acids in urine. 



(/).) Strasburger's Modification. — Dissolve cane-sugar in the suspected 

 urine, di]) into it filter-paper, and allow this to dry. Touch tlie i)a])cr with a 

 glass rod dipped in strong sulphuric acid, a purple-violet colour indicates the 

 presence of the bile-pigments. 



(c.) Sulphur Test.- Try this (Lesson XI. 5). 



4. Sugar in Urine (Glycosuria). — Briicke maintains that the 

 merest trace of glucose or grape-sugar is normally present in urine. 



