Experimental investigation of the reactions of various copper salts with grape sugar : some new and reliable tests for sugar in urine / by George Hay, M.D.

  • Hay, George, M.D.
Date:
[1885?]
Catalogue details

Licence: Public Domain Mark

Credit: Experimental investigation of the reactions of various copper salts with grape sugar : some new and reliable tests for sugar in urine / by George Hay, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    Heat. Very soon a precipitate forms, dark orange-red, suboxide of copper. c. Sulphate of copper saturated solution, gtt. xv. Urine, f. 3 ij., containing grape sugar, gr. \. Add potash in excess—blue solution. Heat. Reduction very slow. In about an hour yellow precipitate of suboxide of copper. Heating continued precipitate becomes or- ange-yellow suboxide. Let settle. d. Sulphate of copper saturated solution, gtt. xxx. Urine, f. 3 iv., containing grape sugar, gr. ■§■. Greenish precipitate. Heat. Cool by immersion. Filter. Divide filtrate into equal parts. To one part add potash in excess—blue solution. Heat. Fluid becomes clear red by transmitted light, afterwards opaque, and in half an hour contains a reddish-brown pre- cipitate of suboxide of copper. To the other part of filtrate add Rochelle salt grs. iv., then potash in excess—blue solution. Heat. Fluid becomes clear red by transmitted light, afterwards opaque, and in ten minutes contains a distinctly yellow precipitate of suboxide of copper. It ap- pears, therefore, that in this case precipitation is accelerated by the presence of Rochelle salt. In regard to this particular reaction I am informed that I have been anticipated as regards publication. It is a decided improve- ment upon Trommer's test but not half so good as some other tests of my own, which shall be detailed in this article, and which I shall particularly recommend. § 3d. COPPER NITRATE. a. Copper nitrate, strong solution, gtt. x. Water, f. 3 ij. Add potash in excess—pre- cipitate blue hydrated protoxide of copper. Heat. Precipitate soon becomes black prot- oxide. b. Copper nitrate, strong solution, gtt. x. Water, f. 3 ij-, containing grape sugar gr. \. Add potash in excess—blue gelatinous preci- pitate appearing semi-solid in the tube. Heat. In a short time a dirty orangec-olored precipitate of suboxide, which becomes dirtier on continued heating. c. Copper nitrate, 'gtt. x. Urine, f. 3 ij., containing grape sugar gr. \. Greenish-grey precipitate. Add potash in excess—yields dirty blue precipitate. Heat. Reduction very slow and very imperfect, and accom- panied by a great deal of white precipitate which masks the reaction. d. Copper nitrate, gtt. xx. Urine, f. 3 iv., containing grape sugar gr. -|. Greenish-grey precipitate very abundant. Heat. Cool thoroughly by immersion. Filter and divide filtrate into two equal parts. To part 1 add potash in excess—an intense blue solution. Heat. In fifteen minutes yellow precipitate of suboxide of copper, which becomes orange-yellow on continued heating. Let settle. To part 2 add Rochelle salt, grs. iv., and then potash in excess—an intense blue solu- tion. Heat. In five minutes orange yellow precipitate of suboxide of copper. There- fore the precipitation is accelerated by the presence of Rochelle salt, and is much more characteristic. The precipitate becomes darker orange on continued heating. The nitrate yields better results by this method than the sulphate, and it seems to me that phosphates and other interfering sub- stances are more thoroughly removed from the urine. §4th. COPPER ACETATE. a. Copper acetate, saturated solution, gtt. xx. Water, f. 3 ij. Add potash in excess— blue precipitate,hydrated protoxide of copper. Heat. The precipitate becomes black pro- toxide. b. Copper acetate, saturated solution, gtt. xx. Water, f. 3 ij., containing grape sugar, gr. \. Add potash in excess—slight blue pre- cipitate. Heat. Precipitate changes to yel- low, and ultimately becomes a full red sub- oxide of copper. c. Copper acetate saturated solution, gtt. xx or more. Urine, f. 3 ij., containing grape sugar gr. \. Shake the tube. Abundant grey precipitate. Add potash in excess—greater part of precipitate redissolved to a purple- blue solution. Heat. Fluid becomes clear yellow, next a dingy brown, and yields in half an hour's heating a reddish-brown precipitate of suboxide of copper. d. Copper acetate, saturated solution, gtt. lx or more. Urine, f. 3 iv., containing grape sugar, gr. f. Grey precipitate persistent on shaking. Heat. Buff-colored precipitate, supernatant fluid green. Cool by immersion. Filter, and divide filtrate into two equal parts. To one part add potash in excess. Smoke colored solution. Heat. Fluid becomes yellow then brown, and in fifteen minutes deposits a reddish-brown precipitate of sub- oxide of copper. To the other part add Rochelle salt, grs. iv., and then potash in success. Yields a smoke-colored solution. Heat. Fluid goes through the same changes as when Rochelle salt is absent.