PENTOSES. 769 



The positive detection of this sugar in the urine is difficult, because 

 it is, like dextrose, dextrogyrate and also gives the usual reduction tests. 

 If urine contains a dextrogyrate, non-fermentable sugar which reduces 

 bismuth solutions, then it is very probable that it contains lactose. It 

 must be remarked that the fermentation test for lactose is, according to 

 the experience of LUSK and VOIT/ best performed by using pure cultivated 

 yeact (saccharomyces apiculatus). This yeast only ferments the dex- 

 trose, while it does not decompose the milk-sugar. VOIT claims that if 

 RUBNER'S test is performed without heating to boiling, but only to 80 

 C., the color becomes yellow or brown in the presence of lactose, instead 

 of red. The most positive means for the detection of this sugar is to 

 isolate the sugar from the urine. This may be done by the method 

 suggested by F. HoFMEiSTER. 2 



R. BAUER 3 detects galactose as well as lactose in the urine by oxidation with 

 concentrated nitric acid, producing mucic acid. 



Cammidge's reaction, which is recommended in the diagnosis of acute diseases 

 of the pancreas, consists in that certain urines do not give the phenyl hydrazine 

 reaction directly, but only after boiling with an acid. The reason of this is not 

 known, but in a case examined by SMOLENSK! 4 the reaction to all appearances 

 was due to cane-sugar. 



Pentoses. SALKOWSKI and JASTROWITZ 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 

 KfJLZ and VOGEL small amounts of pentose also occur in the urine of 

 diabetics, as also in the urine of dogs with pancreatic or phlorhizin diabetes. 5 



The pentose isolated by NEUBERG from the urine in chronic pentosuria 

 was i-arabinose. LUZZATTO has studied a case of pentosuria and found 

 /-arabinose (see page 203). 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. G 



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 dextrose small amounts of pentose may also undergo fermentation. 

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



1 Carl Voit, Ueber Die Glycogenbildung nach Aufnahme verschiedener Zuckeraten, 

 Zeitsehr. f. Biologie, 28. 



. 2 Hofmeister Zeitsehr. f. physiol. Chem., 1, which also contains the pertinent 

 literature. 



3 Zeitsehr. f. physiol. Chem., 51. 



4 Ibid., 60. 



5 In regard to the literature, see footnote 1, page 201. See also Blumenthal, 

 " Die Pentosurie," Deutsche Klinik, 1902. 



6 Blumenthal, Deutsche Klinik, 1902; v. Jaksch, Centralbl. f. innere Medizin, 1906. 



