DETECTION OF L^EVULOSE 281 



The capacity of glutaric acid to inhibit the glycosuria of 

 phloridzin intoxication, discovered by E. Baer and Blum, 

 must probably be regarded as in some way connected with 

 an influence of the former upon the kidneys. 26 



Having discussed the nature of the two most important, 

 and as it were classical forms of experimental glycosuria, 

 pancreatic diabetes and phloridzin diabetes, as far as is 

 here possible and as far as the present status of our knowl- 

 edge permits, our attention may next be given to several 

 atypical forms of glycosuria, namely, Icevulosuria, pento- 

 suria and lactosuria. 



L-EVULOSURIA 



The literature devoted to laBvulosuria, as may be seen 

 in the comprehensive articles upon the subject by Neuberg, 27 

 Magnus- Levy 28 and Umber 29 occupies a considerable space, 

 greater, probably, than the actual importance of the sub- 

 ject requires. Many cases in the older literature, said to be 

 instances of laevulosuria because of their polarimetric char- 

 acteristics, should be excluded for the reason that in their 

 determination no care was taken to exclude the possibility 

 that laevogyration might have been due to /2-oxybutyric acid 

 or combined glycuronic acids. 



Detection of Lcevulose. One should not be content in try- 

 ing to determine the existence of a laevulosuriawith the recog- 

 nition of disproportion between polarimetric features, grade 

 of reducing and fermentescibility of the specimen, but 

 should employ more direct methods. SeliwanoiPs test in 

 its various modifications, producing a red color when the 

 specimen is boiled with resorcin and hydrochloric acid, is 

 the most prominent. The red color changes to a yellow 



38 Cf. G. G. Wilenko, Ther. d. Gegenw., 1909, 227; E. Frank and S. Isaak, 

 Verhandl. d. 27. Kongr. f. inner Med. (Senator's Clinic), Wiesbaden, 1910, 

 p. 590. 



21 C. Neuberg, Handb. d. Pathol. d. Stoffwechs., 2d ed., 2, 212-219, 1907. 



28 A. Magnus-Levy, Handb. d. Biochem., 4', 385-394, 1909. 



28 F. Umber, Lehrb. d. Ernahrung, pp. 249-253, 1909. 



