SUGAR IN URINE. 803 



page 214. This test may lead to very great mistakes in urine poor in 

 sugar, especially when they have at the same time normal or increased 

 amounts of physiological constituents, and therefore it cannot be recom- 

 mended to physicians or to persons inexperienced in such work. Normal 

 urine contains reducing substances, such as uric acid, creatinine, and others, 

 and therefore a reduction takes place in all urines on using this test. A 

 separation of copper suboxide does not generally occur, but still if one 

 varies the proportion of the alkali to the copper sulphate and boils, there 

 takes place an actual separation of suboxide in normal urines, or a peculiar 

 yellowish red liquid due to finely divided cuprous hydroxide. This occurs 

 especially on the addition of much alkali or too much copper sulphate, 

 and by careless manipulation the inexperienced worker may therefore 

 sometimes obtain apparently positive results in a normal urine. On the 

 other hand, as the urine contains substances such as creatinine and 

 ammonia (from the urea), which in the presence of only a little sugar 

 may keep the copper suboxide in solution, the investigator may easily 

 overlook small quantities of sugar that may be present. 



The delicacy of TROMMER'S test can be increased by the suggestion made by 

 WoRM-MtJLLER. 1 As by this rather complicated and tedious method small 

 amounts of sugar cannot be detected in certain urines, and also as special urines 

 from healthy persons readily give inconclusive results, and finally as SCHONDORFF 

 has shown in numerous cases that the physiological sugar content of the urine 

 responds to this test in perfectly healthy persons because of its extreme delicacy, 

 it does not seem advisable in HAMMARSTEN'S opinion to recommend this test to 

 the physician. BANG and BOHMANSSON 2 have recently also shown its unre- 

 liability. 



ALMEN'S bismuth test, which has been incorrectly called NYLANDER'S 

 test, is performed with the alkaline-bismuth solution prepared as described 

 on page 214. For each test 10 cc. of urine are taken and treated with 

 1 cc. of the bismuth solution and boiled for a few minutes. In the 

 presence of sugar the urine becomes dark yellow or yellowish brown; 

 then it grows darker, cloudy, dark brown, or nearly black, and non- 

 transparent. After a longer or shorter time a black deposit appears, 

 the supernatant liquid gradually clears, but still remains colored. In 

 the presence of only very little sugar the test does not become black or 

 dark brown, but simply deeper colored, and not until after some time 

 is there seen on the upper layer of the phosphate precipitate a dark or 

 black layer (of bismuth?). In the presence of much sugar a larger 

 amount of the reagent may be used without disadvantage. In a urine 

 poor in sugar only 1 cc. of the reagent for every 10 cc. of the urine must 

 be employed. 



1 In regard to this test see Pfliiger, Pfliiger's Arch., 105 and 106; Hammarsten, 

 ibid., 116, and Zeitschr. f. physiol. Chem., 50. 



2 Schondorff, Pfluger's Arch., 121; Bohmansson, Bioch. Zeitschr., 19. 



