A manual of chemistry : containing a condensed view of the present state of the science, with copious references to more extensive treatises, original papers, &c: intended as a text-book for medical schools, colleges, and academies . used in the arts. They are not so liable to crack as theHessian crucibles, but they are destroyed by long exposure to a cur-rent of heated air, and by nitre and some other saline substances. Cru-cibles made of Wedgewoods ware are very compact, and should beplaced in a common crucible when they are used, as they are apt tocrack Platinum crucibles will bear a very i
A manual of chemistry : containing a condensed view of the present state of the science, with copious references to more extensive treatises, original papers, &c: intended as a text-book for medical schools, colleges, and academies . used in the arts. They are not so liable to crack as theHessian crucibles, but they are destroyed by long exposure to a cur-rent of heated air, and by nitre and some other saline substances. Cru-cibles made of Wedgewoods ware are very compact, and should beplaced in a common crucible when they are used, as they are apt tocrack Platinum crucibles will bear a very intense heat, and are notacted upon by any of the simple acids; they are therefore of greatvalue in chemical analysis. p- ^ CUPEL. A small vessel made of calcined bones,or bone ashes, upon which we cupel silver with leadin the assaying furnace. It is prepared most easilyby driving pounded bone ashes into a small brass oriron mould by means of a pestle forcibly struck by awooden mallet. It must then be removed cautiously,placed on a piece of paper, and dried before using mould is open above and below, and may be com-pared to the section of a tube with thick sides. Thepestle is made so as to give the necessary APPENDIX. 445 CYANOMETER. An instrument invented by Saussure, for com-paring the different shades of blue. Fig. 16.
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Keywords: ., bookcentury1800, bookde, bookpublishernewyorkwedean, bookyear1838
