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 . es in use, which differmainly in their constructionfor delivery : Gay Lussacsburette, Geislers burette,and Mohrs burette. Of these, Mohrs buretteis now in general use ; itconsists of a graduated glasstube, of about h
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 . es in use, which differmainly in their constructionfor delivery : Gay Lussacsburette, Geislers burette,and Mohrs burette. Of these, Mohrs buretteis now in general use ; itconsists of a graduated glasstube, of about half an inchinside width, and about 30inches in length ; to its con-tracted lower extremity isfitted (Fig. 22) a small pieceof caoutchouc tube; into theother end of which a smallpiece of narrow glass tube,about 1 inch long, is tight-ly inserted. A strong wireclamp (Fig. 23) closes therubber tube so that the fluidcan only pass through, ei-tlier in a stream or drop bydrop, when the knobs of theclamp are pressed. Since the correctness of the test depends upon the accurate read-ing of the height of the test-solution in the burette, a smallhollow glass float is employed for this purpose (Fig. 24); it isof such a width that it can move freely in the tube withoutundue friction, and of such a weight that it sinks to morethan half its length into the test-liquid. A line is scratched. Fig. 22. < 56 MANUAL OF CHEMICAL ANALYSIS. around the centre of the float, serving to mark the heightof the fluid in the burette. Burettes are conveniently kept for ready use on a revolvingstative (Fig. 25). The tests are made by first filling the burette with the test-solution to exactly such height that the mark on the float iscoincident with the 0 on the scale of the tube. The solu-tion or mixture to be tested is placed in a beaker-glass underthe burette (Fig. 21), and then so much of the test-solution isgradually and carefully delivered into the beaker, with gen-
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Keywords: ., bookcentury1, bookdecade1870, booksubjectpharmaceuticalchemistry
