436 PHYSIOLOGICAL CHEMISTRY 



(e) Haines' Test. This is a copper reduction test similar in many 

 respects to the Fehling and Benedict reactions. In Haines' solution 1 

 the cupric hydroxide is held in solution by glycerol instead of Rochelle 

 salt as in Fehling's solution. 



Perform the test as follows : Introduce about 5 c.c. of Haines' solution 1 into a 

 test-tube and heat to boiling. If no reduction occurs add 6-8 drops of the urine 

 and again bring to a boil. If glucose is present an abundant yellow or brownish- 

 red cuprous oxide precipitate is thrown down. This test is about as delicate as 

 Fehling's test. 



(f) Bismuth Reduction Test (Nylander). To 5 c.c. of urine hi a test-tube 

 add one-tenth its volume of Nylander's reagent 2 and heat for five minutes 

 in a boiling water-bath. 3 The mixture will darken if reducing sugar is present 

 and upon standing for a few moments a black color will appear. 



This color is due to the precipitation of bismuth. If the test is 

 made on urine containing albumin this must be removed, by boiling 

 and filtering, before applying the test, since with albumin a similar 

 change of color is produced. Glucose when present to the extent of 

 0.08 per cent may be easily detected by this reaction (Rabe 4 claims that 

 o.oi per cent may be so detected). Uric acid, creatinine and homo- 

 gentisic acid which interfere with the Fehling test do not interfere with 

 the Nylander's reaction. It is claimed by Bechold that the bismuth 

 reduction tests give a negative reaction with solutions containing 

 sugar when mercuric chloride or chloroform is present. Other ob- 

 servers 5 have failed to verify the inhibitory action of the mercuric 

 chloride and have shown that the inhibitory influence of chloroform 

 may be overcome by raising 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, urcchrome or hematopcrphyrin, 

 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. 6 



1 Haines solution may be prepared by dissolving 8.314 grams of copper sulphate in 

 400 c.c. of water adding 40 c.c. of glycerol and 500 c.c. of 5 per cent potassium hydroxide 

 solution. 



2 Nylander's reagent is prepared by digesting 2 grams of bismuth subnitrate and 4 grams 

 of Rochelle salt in 100 c.c. of a 10 per cent potassium hydroxide solution. The reagent is 

 then cooled and filtered. 



3 Hammarsten suggests that the solution be boiled for 2-5 minutes (according to the 

 sugar content). over a free flame and the tube then permitted to stand five minutes before 

 drawing conclusions. 



4 Rabe: Apoth. Ztg., 29, 554, 1914. 



5 Rehfuss and Hawk: Jour. Biol. Chem., 7, 267, 1910; also Zeidlitz: Upsala LakSre- 

 foren Fork., N. F., n, 1906. 



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

 1909. 



