814 URINE. 



ment and with sufficient practice very exact results can be obtained by 

 this method. The value of this procedure consists in the rapidity with 

 which the determination can be made. In using instruments specially 

 constructed for clinical purposes the accuracy is less than with the less 

 expensive fermentation test. Under such circumstances, and as the 

 estimation by means of polarization can be performed with exactitude 

 only by specially trained chemists, it is hardly worth while to give this 

 method in detail, and the reader is referred to handbooks for hints in the 

 use of the apparatus. 



HASSELBACH and LINDHARD : have recently suggested a method for the 

 quantitative estimation of sugar which is based on the decolorization of an alkaline 

 saf ranin solution in the presence of sugar. 



Fructose (levulose). Levogyrate urines containing sugar have been 

 noted by several investigators, although the nature of the sugar was not 

 well known to the earlier observers. In recent years several positively 

 authentic cases of levulosuria have been described, and also cases of 

 diabetes have been found where fructose exists in the urine besides glucose. 

 Reports on this subject do not agree, however. 2 



Fructose may be. detected as follows : The urine is levorotatory, and 

 the levorotatory substance ferments with yeast. The urine gives the 

 ordinary reduction tests and the ordinary phenylglucosazone. With 

 methylphenylhydrazine it gives the characteristic fructose methyl- 

 phenylosazone, and it also gives SELIWANOFF'S reaction on heating 

 after the addition of an equal volume of hydrochloric acid and a little 

 resorcin. With this test it must be remarked that too lengthy or too 

 strong heating must not be applied, since other carbohydrates may also 

 give the reaction (see page 218 and the works of ROSIN and UMBER 3 ). 

 In the presence of fructose a red coloration appears. After cooling it 

 can be neutralized with soda and shaken out with amyl alcohol, (RosiN) 

 or with acetic ether (BORCHARDT). The amyl alcohol removes a red 

 pigment which gives a band in the spectrum between E and b and on 

 stronger concentration also a band 'in the blue at F. The acetic ether 

 in the presence of fructose becomes yellow, and this is more characteristic 

 according to BORCHARDT than ROSIN'S method, which has certain 

 fallacies. The simultaneous presence of nitrites and indican disturbs 

 the test, and in this case first remove the nitrous acid by boiling the 

 urine, acidified with acetic acid or hydrochloric acid for one minute. In 

 order to remove other disturbing pigments, MALFATTI suggests the 

 oxidation of the urine with a little hydrochloric acid and potassium 

 permanganate. JoLLES 4 has suggested a method for detecting fructose 

 besides glucose by means of a diphenylamine solution. 



1 Bioch. Zeitschr., 27. 



'See Borchardt, Zeitschr. f. physiol. Chem., 55 and 60; W. Voit, ibid., 58 and 61; 

 Adler, Pfliiger's Arch., 139. 



1 Umber, Salkowski's Festschrift, Berlin, 1904; Rosin, ibid., and Zeitschr. f. 

 physiol. Chem., 38. 



4 Rosin, 1. c.; Borchardt, 1. c.; Malfatti, Zeitschr. f. physiol. Chem., 58; Jolles 

 and Mauthner, Chem. Centralbl., 1910, 1, 483. 



