SUGAR. 759 



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 MULLER.* 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 per- 

 fectly healthy persons because of its extreme delicacy, it does not seem 

 advisable in HAMMARSTEX'.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 de- 

 scribed on page 208. 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. 



Small amounts of proteid may retard this reaction and reduce the 

 delicacy of the test. Large quantities of proteid may, however, give 

 rise to an error by forming bismuth sulphide, and therefore it must 

 always be first removed. The assertion of BECHHOLD that mercury 

 compounds in the urine disturb the test has not been substantiated by 

 ZEIDLITZ 3 on properly performing the test. Those sources of error 

 which in TROMMER'S test are caused by the presence of uric acid and 

 creatinine are removed by using this test. The bismuth test is, more- 

 over, readily performed, and on this account is to be recommended to 

 the physician. 



The bumping and ejection of the fluid can be readily prevented by heating 

 over a very small flame after the test has been brought to a boil, and by gently 



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

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



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



3 Bechhold, Zeitschr. f. physiol. Chem., 46; Zeidlitz, Upsala Lakaref. Forh. (N. F.), 

 11 (Hammarsten Festschr). 



