Manual of chemical analysis as applied to the examination of medicinal chemicals : a guide for the determination of their identity and quality, and for the determination of their identity and quality, and for the detection of impurities and adulterations : for the use of pharmaceutists, physicians, druggists, and manufacturing chemists, and of pharmaceutical and medical students . is then deliv-ered into this liquid (Fig. 77),with constant stirring, until theensuing precipitate ceases tobe redissolVed, and therefore aslight permanent turbidity oc-curs. The quantity of argen-tic nitrate employe
Manual of chemical analysis as applied to the examination of medicinal chemicals : a guide for the determination of their identity and quality, and for the determination of their identity and quality, and for the detection of impurities and adulterations : for the use of pharmaceutists, physicians, druggists, and manufacturing chemists, and of pharmaceutical and medical students . is then deliv-ered into this liquid (Fig. 77),with constant stirring, until theensuing precipitate ceases tobe redissolVed, and therefore aslight permanent turbidity oc-curs. The quantity of argen-tic nitrate employed representsexactly half the amount ofhydrocyanic acid, and has,therefore, to be multiplied byfour, to obtain the percentage. 2. Another method consistsin dissolving 50 grains of theoil in half a fluidounce of alco-hol, in a small flask, and add-ing about four ounces of wa-ter ; to this solution is thenadded a solution of 30 grainsof argentic nitrate in fourfluid-drachms of aqua ammo-nise ; the mixture is then gen-tly warmed to about 50° C, and, after repeated agitation, anexcess of nitric acid is added, and the whole gently warmed byimmersing the flask in hot water. The precipitate of argenticcyanide is collected upon a tared and moist filter, washed untilthe washings cease to redden blue litmus-paper, and then driedand weighed. The number of grains of the weight of the. Fig. 77. 276 MANUAL OF CHEMICAL ANALYSIS. dry argentic cyanide being divided by live, the quotient, multi-plied by two, gives tlie percentage of anhydrous hydrocyanicacid contained in the oil. Examination: Alcohol may be detected in oil of bitter almonds by agitat-ing it with three times its volume of concentrated nitric acid,and subsequently warming the mixture by dipping the test-tube into hot water. No reaction takes place with pure oil;but, if it has an admixture of more than three per cent, of alco-hol, effervescence will occur, with disengagement of yellowishnitrous vapors. Chloroform^ as well as alcoho
Size: 1074px × 2328px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1, bookdecade1870, booksubjectpharmaceuticalchemistry
