Laboratory Notes on Quantitative Analysis

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1885 edition. Excerpt: ...is in excess the precipitate is flocculent and subsides rapidly, but when the zinc is nearly all precipitated, the precipitate becomes fine and subsides very slowly, and a drop or two will produce the flesh color. Potassium Xanthate. Dissolve some caustic potash in absolute alcohol, filter if necessary, and add to the filtrate a large excess of carbon disulphide; a crystalline mass will soon form, which is brought on a filter and quickly washed with ether, and dried over sulphuric acid and paraffin. When dry, place in well corked bottles, and dissolve in water only the required amount when need for use, for the solution soon deteriorates. Zinc Amalgam. Place a quantity of granulated zinc in a dish, cover with mercury, and add a very dilute solution of sulphuric acid, and stir till action ceases; then place in a funnel to drain off the excess of mercury. BYRON W. CHEEVER, A. M., M. D., Acting Professor of Metallurgy in the University of Michigan. PART SECOND. ANN ARBOR: REGISTER PRINTING AND PUBLISHING HOUSE. 1 H K r. Select Methods in Quantitative Analysis-Limestone. For technical purposes, it is sufficient to determine those constituents which perform the active part in any given operation. The more common constituents oi' limestone may be determined as follows: Pulverize a few grms, dry at 100c' C. Weigh 1 grin of the dry sample, transfer it to a porcelain dish cover with a clock-glass, add 20 c.c. of water, then 10 c.c. of HCl, and 2 c.c. of HN03, heat till effervescence ceases, remove the cover, and evaporate to dryness on the water bath. When perfectly dry, cool, moisten with HCl, add water and heat until dissolved, then filter. Res (a)=Silica and silicates; dry, ignite and weigh; mix the ignited residue with ammonium fluoride, cover...