816 URINE. 



Pentoses. SALKOWSKI and J ASTRO WITZ first found in the urine of 

 persons addicted to the morphine habit a variety of sugar which was a 

 pentose and yielded an osazone which melted at 159 C. Since this 

 several other cases of pentosuria have been observed, and according to 

 KULZ and VOGEL and others small amounts of pentose also occur in the 

 urine of diabetics, as also in the urine of dogs with pancreatic or phlorhizin 

 diabetes. 1 



The pentose isolated by NEUBERG from the urine in chronic pentosuria 

 was cW-arabinose. LUZZATTO and KLERCKER studied cases of pento- 

 suria and found Z-arabinose. In alimentary pentosuria the Z-arabinose 

 of the plant food may be found in the urine. The appearance of pentoses 

 in the urine after eating fruits and fruit-juices has been repeatedly 

 observed by BLUMENTHAL and also by v. JAKSCH. According to COMI- 

 NOTTI 2 pentoses habitually occur in human urine on a mixed diet. 



A urine containing pentose reduces bismuth as well as copper solu- 

 tions, although the reduction is not so rapid, but appears gradually. 

 If only pentose is present, the urine does not ferment, but in the presence 

 of glucose small amounts of pentose may also undergo fermentation. 

 The preparation of the osazone serves in the detection of pentoses and 

 when obtained from the urine it melts at 156-160 C. The phloroglucin 

 or orcin tests can also be employed (see page 209). Of these the last is 

 most preferable, especially as it excludes a confusion with the conjugated 

 glucuronic acids. 



The orcin test can be performed as follows: 5 cc. of the urine are mixed 

 with an equal volume of HC1 sp.gr. 1.19, a small amount of orcin added and 

 the whole heated to boiling. As soon as a greenish cloudiness appears 

 cool the mixture off and shake carefully with amyl alcohol. The amyl- 

 alcohol solution is used in the spectroscopic examination. The pre- 

 cipitation of a bluish-green pigment is in itself significant. 



BIAL 3 uses as reagent 30 per cent hydrochloric acid, which contains 1 gram 

 of orcin and 25 drops of a ferric-chloride solution (62.9 per cent of the crystalline 

 salt) in 500 cc. of the acid. 4.5 cc. of the reagent are heated to boiling and then a 

 few drops (not more than 1 cc.) of the urine are added to the hot but not boiling 

 liquid. In the presence of pentose the liquid turns a beautiful green. The use- 

 fulness of BIAL'S reagent is questioned by several experimenters. The delicacy 

 is too great and the possibility of confounding with other carbohydrates is not 

 excluded. In regard to the numerous modifications of this test and to JOLLES' 

 reaction we refer to page 209. The same for the quantitative estimation of pen- 



*In regard to the literature, see footnote 1, page 208. See also Blumenthal, 

 "Die Pentosurie," Deutsche Klinik, 1902. 



2 Blumenthal, Deutsche Klinik, 1902; v. Jaksch, Centralbl. f. innere Medizin, 

 1906; Cominotti, Bioch. Zeitschr., 22. 



3 Deutsch. med. Wochenschr., 1903; see also footnote 4, page 209. 



