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 . d, the test-solu-tion is delivered into the beaker, first in a stream, and, when ap-proaching tlie point of saturation, drop by drop, until the blueassumes a violet hue; the solutions of carbonates have to beheated b
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 . d, the test-solu-tion is delivered into the beaker, first in a stream, and, when ap-proaching tlie point of saturation, drop by drop, until the blueassumes a violet hue; the solutions of carbonates have to beheated before approaching saturation, in order to expel the VOLUMETRIC ANALYSIS. 59 carbonic-acid gas from thesolution as nearly as possible,and thereby to lessen its reac-tion upon litmus. These operations requirecare and skill in every point,so as to avoid the slightest lossof either of the liquids, anda consequent error in the re-sult. When saturation is indi-cated by the violet-reddishcolor of the liquid, the pro-cess is complete, and the vol-ume of test-acid employed isread off. The number of cu-bic centimetres employed, lessthan 100, indicates at oncethe percentage of impuritiesor of want of strength. On the other hand, eachcubic centimetre of the test-so-lution employed cori-espondsto one milligramme-moleculeof hydrate or one-half milli-gramme-molecule of carbon-ate, i. e.:. 1 cubic centimetre corresponds to gramme Potassii Hydras, 1 Potassii Carbonas, 1 * Sodii Hydras, 1 Sodii Carbonas (anhydrous), and a simple equation gives the amount of alkaline hydrate orcarbonate present. By operating on 100 times the half-milli-gramme-molecule, i. e., grammes of potassium carbonate grammes ot sodium carbonate, all calculation is dispensedwith; for, as this amount, if present, would require 100 cubiccentimetres of oxalic-acM test-solution for its saturation, the lJ /4ClCe 1 n^,%i. ,:=/.*^^^^^^^. 60 MANUAL OF CHEMICAL ANALYSIS. number of cubic centim
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Keywords: ., bookcentury1, bookdecade1870, booksubjectpharmaceuticalchemistry
