URINE 421 



the temperature of the urine to the boiling-point for a period of five 

 minutes previous to making the test. 



Urines rich in indican, uroerythrin, urochrome or hematoporphyrin, 

 as well as urines excreted after the ingestion of large amounts of certain 

 medicinal substances, may give a darkening of the Nylander's reagent 

 similar to that of a true sugar reaction. It is a disputed point whether 

 the urine after the administration of urotropin will reduce the Nylan- 

 der reagent. 1 



Strausz 2 has recently shown that the urine of diabetics to whom 

 "lothion" (diiodohydroxypropane) has been administered will give a 

 negative Nylander's reaction and respond positively to the Fehling and 

 polarization tests. " lothion" also interferes with the Ny lander test 

 in vitro whereas KI and I do not. 



According to Rustin and Otto the addition of PtCl 4 increases the s 

 delicacy of Nylander's reaction. They claim that this procedure causes 

 the sugar to be converted quantitatively. No quantitative method has 

 yet been devised, however, based upon this principle. 



A positive bismuth reduction test is probably due to the following 

 reactions: 



(a) Bi(OH) 2 (NO) 3 +KOH-+Bi(OH)3+KNO 3 . 



(b) 2Bi(OH) 3 30-Bi 2 +3H 2 0. 



Bohmansson, 3 before testing the urine under examination treats it 

 (10 c.c.) with J-'5 volume of 25 per cent hydrochloric acid and }- volume 

 of boneblack. This mixture is shaken one minute, then filtered, 

 and the neutralized filtrate tested by Nylander's reaction. Bohmansson 

 claims that this procedure removes certain interfering substances, 

 notably urochrome. 



6. Fermentation Test. Rub up in a mortar about 15 c.c. of the urine with a 

 small piece of compressed yeast. Transfer the mixture to a saccharometer 

 (Fig- 3> page 31) and stand it aside in a warm place for about 12 hours. If glu- 

 cose is present, alcoholic fermentation will occur and carbon dioxide will collect 

 as a gas in the upper portion of the tube. On the completion of fermentation, 

 introduce, by means of a bent pipette, a little KOH solution into the graduated 

 portion, place the thumb tightly over the opening in the apparatus and invert the 

 saccharometer. Remembering that KOH has the power to absorb CO 2 how 

 do you explain the result? 4 



7. Polariscopic Examination. For directions as to the use of the polariscope 

 see Chapter II. 



1 Abt: Archives of Pediatrics, 24, 275, 1907; also Weitbrecht: Schweiz. Woch., 47, 577, 

 1909. 



2 Strausz: Munch, med. Woch., 59, 85, 1912. 



3 Bohmansson: Biochem. Zeit., 19, p. 281. 



4 The findings of Neuberg and associates indicate that the liberation of carbon dioxide 

 by yeast is not necessarily a criterion of the presence of sugar. The presence of an enzyme 

 called carboxylase has been demonstrated in yeast which has the power of splitting off CO* 

 from the carboxyl group of amino- and other aliphatic acids. 



