804 URINE. 



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 on properly performing the test, and recently REHFUSS and 

 HAWK 1 came to the same conclusion. 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, moreover, 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 

 shaking the contents of the not too narrow test-tube. The recommendation 

 of heating for a longer time in the water-bath, fifteen minutes or more, is to be 

 discarded, as the delicacy of the test is thereby so much increased that it gives 

 a reaction with a physiological sugar content of 0.02 per cent. 



When the amount of sugar in the urine is not less than 0.1 per cent 

 a positive reaction is obtained if the test is boiled for 2-3 minutes and 

 then allowed to stand quietly for 5 minutes. The phosphate precipitate 

 is then black or nearly black. In detecting smaller quantities of sugar 

 0.05 per cent, the test as a rule must be boiled longer about 5 minutes. 



The value of this test lies in the fact that it positively detects small 

 quantities of sugar 0.1 per cent or somewhat less, and that when the 

 urine gives negative results we can consider it free from sugar in a clinical 

 sense. Like TROMMER'S test it is a reduction test, and shows also certain 

 other reducing bodies besides the sugar. These bodies are certain con- 

 jugated glucuronic acids which may appear in the urine. After the use 

 of certain therapeutic agents, such as rhubarb, senna, antipyrine, salol, 

 turpentine and others, the bismuth test gives positive results. From 

 this it follows that we should never be satisfied with this test alone, espe- 

 cially when the reduction is not very great. 



According to BOHMANSSON and BANG this test is perfectly reliable 

 if about 20 cc. of the urine is treated with 5 cc. of 25 per cent HC1 and 

 2 grams blood-charcoal (a teaspoonful) added and shaken every once in 

 a while during five minutes and then filtered. The filtrate on neutraliza- 

 tion with caustic soda is used for the ALMEN test. The disturbing reduc- 

 ing substances are removed by the animal charcoal, but the sugar is not. 



According to ANDERSEN 2 this procedure cannot be used in the quan- 



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

 11 (Hammarsten Festschr.); Rehfuss and Hawk, Journ. of biol. Chem., 7. 



2 Bohmansson and Bang, Bioch. Zeitschr., 19, and Zeitschr. f. physiol. Chem., 

 63; Andersen, Bioch. Zeitschr., 37. 



