BILE PIGMENTS. 801 



and then with a solution of sodium or ammonium carbonate. The pre- 

 cipitate which contains the bile-coloring matter is filtered, washed, dis- 

 solved in alcohol which contains 5 cc. of concentrated hydrochloric acid 

 in 100 cc. (I. MUNK), and heated to boiling, when the solution becomes 

 green or bluish green. According to NAKAYAMA 1 this reaction is more 

 delicate on using a mixture of ferric chloride, acid, and alcohol. 



HAMMARSTEN'S Reaction. For ordinary cases it is sufficient to add 

 a few drops of urine to about 2-3 cc. of the reagent (see page 432), when 

 the mixture immediately after shaking turns a beautiful green- or bluish 

 green, which color remains for several days. In the presence of only 

 very small quantities of bile-pigments, especially when blood or other 

 pigments are simultaneously present, pour about 10 cc. of the acid or 

 nearly neutral (not alkaline) urine into the tube of a small centrifugal 

 machine and add BaCb solution and centrifuge for about one minute. 

 The liquid is decanted and the sediment stirred with about 1 cc. of the 

 reagent and centrifuged again. A beautiful green solution is obtained 

 which may be changed, by the addition of increased quantities of the acid 

 mixture, to blue, violet, red, and reddish yellow. The green color may 

 be obtained in the presence of 1 part bile-pigment in 500,000-1,000,000 

 parts urine. In the presence of large amounts of other pigments calcium 

 chloride is better suited than barium chloride. 



BouMA 2 has suggested the use of alcohol containing ferric chloride 

 and hydrochloric acid instead of the above-mentioned acid mixture. He 

 has also worked out a colorimetric method of quantitative estimation 

 of bilirubin in urine by means of this reagent. 



As above indicated, we have a great many other tests besides these 

 given above. A very complete summary of these tests and the literature 

 thereof can be found in the work of OBERMAYER and POPPER. 



For ordinary purposes the above-mentioned tests are sufficiently 

 delicate, and according to HAMMARSTEN it is not advisable, as also in the 

 case of the detection of proteid, sugar, etc., to increase the delicacy of 

 a test so that it shows the presence of the traces of the questionable 

 substance in normal urine. If in certain cases a greater delicacy is 

 required than is obtained with the above tests, then we must recommend 

 the flotation test of OBERMEYER and POPPER 3 with iodine and salt. 



MEDICINAL COLORING-MATTERS produced from santonin, rhubarb, senna, etc., 

 may give an abnormal color to the urine and may be mistaken for bile-pigments, 

 or, in alkaline urines, perhaps for blood-coloring matters. If hydrochloric acid 

 is added to such a urine, it becomes yellow or pale yellow, while on the addition 

 of an excess of alkali it takes on a more or less beautiful red color. 



1 Munk, Arch. f. (Anat. u.) Physiol., 1898; Nakayama, Zeitschr. f. physiol. Chem., 



2 Deutsch. med. Wochenschr., 1902 and 1904 

 Wien. med. Wochenschr., 21. 



