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 . lphur be free from arsenic). Any admixture, except powdered resin or pitchy which arerecognized by a sooty flame when ignited, and by their solu-bility in strong alcohol or ether, may be quantitatively deter-mined by
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 . lphur be free from arsenic). Any admixture, except powdered resin or pitchy which arerecognized by a sooty flame when ignited, and by their solu-bility in strong alcohol or ether, may be quantitatively deter-mined by remaining behind upon solution of a known quantityof the sulphur in carbon bisulphide, or, when calcium sulphateis the only admixture, by complete incineration of a weighedquantity of the sulphur in a tared porcelain crucible; theweight of the remaining anhydrous calcium sulphate, with one-fourth thereof added to make up for the loss of the water ofcrystallization, gives the amount of crystalline calcium sulphatepresent in the quantity of sulphur under examination. Arsenic may be detected by triturating and digesting about30 grains of the sulphur with half an ounce of solution of am-monium sesqui-carbonate, or aqua ammonise, in a corked test-tube, for about one hour, with occasional agitation ; the liquidis then passed through a filter, and a portion of the filtrate over-. FiG. 94. saturated with hydrochloric acid ; the formation of a yellowprecipitate would indicate arsenic; the rest of the filtrate is SULPHUR. 3^1 evaporated to dryness in a small porcelain capsule; if a residueremains, it is scraped off bv triturating it with a few grains ofpowdered magnesite, or pumice-stone ; a few grains of potassi-um cyanide are added, and the mixture gently warmed so as toexpel moisture; it is then introduced into a reduction-tubeand heated (Fig. 94); whereupon, the formation of a metallicmirror and the evolution of a garlic-like odor would furtherindicate arsenic. An admixture of starc
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Keywords: ., bookcentury1, bookdecade1870, booksubjectpharmaceuticalchemistry
