Plattner's manual of qualitative and quantitative analysis with the blowpipe; . largeamount of soda produces a blue color, and a smaller quantity is notperceptible. The flame of a Bunsen burner, p. 9, Fig. 8, or the blue blow-pipe flame may be employed. In the latter case a small stand. , renders the observation more the small tube, h, fastened in an iron orlead foot, the wire, s, is made to slide at pleas-ure, and it supports in a clamp the cobaltglass, g. A few experiments will determinethe proper situation for the glass between theeye and the flame, and give practice in


Plattner's manual of qualitative and quantitative analysis with the blowpipe; . largeamount of soda produces a blue color, and a smaller quantity is notperceptible. The flame of a Bunsen burner, p. 9, Fig. 8, or the blue blow-pipe flame may be employed. In the latter case a small stand. , renders the observation more the small tube, h, fastened in an iron orlead foot, the wire, s, is made to slide at pleas-ure, and it supports in a clamp the cobaltglass, g. A few experiments will determinethe proper situation for the glass between theeye and the flame, and give practice in holdingthe platinum wire with the assay in the tip ofthe blue flame, which is not visible throughthe glass. For the indigo solution a smallopen vessel may be formed by means of glassstrips and a suitable cement, and then also setupon a stand. If the assay contains substances which pro-duce a luminous flame, as in the separation of * The solution, which must bo filtered, contains in 1500 to 2000 parts water, 1part indigo, previously dissolved in 8 parts fuming sulphuric 104 plattneks blowpipe analysis. carbon from buniing organic matter, these must first be removed byigniting the assay, since otherwise the same violet color will be per-ceived through the glass as that caused by potassa. The violet andred rays proceeding from the glowing wire must likewise not be con»founded with the proper potassa coloration, which rather extends outfrom the assay toward the tip of the flame.* Viewed through moderately thick cobalt glass, or a thin stratumof indigo solution, the lithia flame is carmine-red, but through verydark or thick glass, or a thicker stratum of solution, it ceases to bevisible, while the red potassa flame is still distinctly seen, and, there-fore, when potassa is to be detected in presence of lithia, a thicker ordarker glass must be used, the effect of which has been previouslytested with pure salts. According to observations by Merz {Journal f. praTct. Ch. vol. 80


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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1902