The Mineral Agent's Handbook, Ed. by S. Haughton and R.H. Scott (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 edition. Excerpt: ... and appear as a whitish precipitate. If it be required to prove that the earth is lime, the solution must be boiled, in order to throw down the residue of the iron as hydrated peroxide. The liquid, after nltration, will contain the lime, and yield a white precipitate with oxalate of ammonia. B.--Quantitative.--Proceed exactly as in the second method for the estimation of phosphoric acid in iron ore, with the exception that, before adding carbonate of soda to the solution, you add a few drops of the perchloride of iron, if that metal be not present in the assay. IX. To ASCERTAIN THE AMOUNT OP ARSENIC IN Ibon Pybites, Qttai-i TATIVE AND QUANTITATIVE. A.--Qualitative.--Pulverize the mineral, and introduce a small quantity of it into a bulb test-tube. Add six times the volume of the assay of dried carbonate of soda and cyanide of potassium, mixed in equal volumes, taking care that the bulb is not more than half full. Heat over a spiriMamp, beginning at the top of the tube, and going down gradually to the bulb. If arsenic be present in the mineral, a black mirror of arsenic will be formed near the top of the tube, and by driving it up by heat to the very top of the tube, the odour of garlic, arising from metallic arsenic, will be perceptible. If this test be insufficient, dissolve the black sublimate by boiling for an hour or more, until dissolved, in aerated water (i. e. distilled water, which has been exposed to the action of the air for a fortnight or so). This gives a solution of arsenious acid. Add acetic acid and excess of caustic potash, until the liquor is alkaline; then evaporate to dryness, and calcine the residue. A substance called alkarsin will be formed, the odour of which is so powerful and unpleasant, that it cannot be mistaken....