A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . m time to time. The crudemass oljtained, which is contaminated with tarry matter, free acid and water, is next dried,by gently heating it on a cast-iron plate under a dome. The grayish-white mass renuxiningis now ready to be transferred to the sul)limers. The method of snftUmatirni generally adopted in this country consists in beatingdown into the metal pots, shown in fi;j- -> the charge of dry coarsely crj^stallizcd sal am-moniac. These pots are heated from
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . m time to time. The crudemass oljtained, which is contaminated with tarry matter, free acid and water, is next dried,by gently heating it on a cast-iron plate under a dome. The grayish-white mass renuxiningis now ready to be transferred to the sul)limers. The method of snftUmatirni generally adopted in this country consists in beatingdown into the metal pots, shown in fi;j- -> the charge of dry coarsely crj^stallizcd sal am-moniac. These pots are heated from below and by flues round the siiies. The l)ody of thesubliming vessel is of cast-iron, and the lid usually of lead, or, less frequently, iron. Thereis a small hole at the top, to permit the escape of steam ; and great attention is requisite inthe management of the heat, for if it be applied too rapidly a large quantity of sal ammoniac 90 AMMOiflUM, CHLORIDE OF. is carried off with the steam, or even the whole apparatus may be blown up ; whilst, if thetemperature be too low, the cake of sal ammoniac is apt to be soft and The sublimation is never continued until the whole of the salt has been volatilized, sincethe heat required would decompose the carbonaceous impurities, and they, emitting volatileoily hydrocaibons, diminish the purity of the product. In consequence of this incompletesubUmation, a conical mass (shown in Jig. 29) is left behind, called the yolk. After 29
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
