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Review of American Chemical Reseamh.
Clay Resources of Ilissouri. BY H. A. WHEELER. f%g. Min. J . , 66, 426-427.-The paper includes statistics relating to t h e character, use, output, and price of the clays, with a description of the condition of the industry. Analyses a r e given for white-ware clays, fire clays, potter's clays, shales, brick clays, and gumbo clays. The Alkaline Reaction of Some Natural Silicates. BY F. W. CLARKE. /. Am. Chenz. Soc., 20, 739-742.-on adding distilled water containing a very little alcoholic phenolphthalein to samples of certain finely pulverized silicates, including micas, feldspars, zeolites, etc., alkaline reactions were immediately obtained. As would be expected, the colors were most intense in the case of those minerals which in nature are most subject to alteration. Similar results were also obtained from tests upon the common igneous rocks. T h e rapidity of the action is a striking feature. Petroleum Inclusions in Quartz Crystals. BY CHAS. I,. REESE. /. Am. Chem. SOL.,20, 7gj-797.-Crystals of quartz with petroleum inclusions from Marshall Co., Ala., are described and illustrated. T h e petroleum was recognized by its fluorescence, odor, and combustibility. Mineral Resources of Cuba. BY RAIMC'KDO CABRERA, translated by L.E. LEVY. J . l k n h h z h z s t . , 146, 26-41.--I)escriptioris and analyses are given of the more important ores and economic deposits including asphaltum, phosphate rock, and the ores of gold, silver, lead, copper, iron, and manganese. The Slate Regions of Pennsylvania. BY MASSFIELD MERStone, 17, 77-go.-A description is given of each of the principal slate-producing regions, accompanied by tables of statistics relating to the output and properties of the slates. T h e probable resistance to corrosion by smoke, sulphurous vapors, etc., was tested by treatment for 63 hours in a 2 per cent. solution of HCl f H,SO,. T h e results are given in a tabulated form. The Bayport, nichigan, Quarries. BY A . C. BENEDICT. Stone, 17, 153-164.-The limestone from these quarries is used as road metal, building stone, or burned for lime. Analyses are given for the building stone and lime varieties. RIMAN.
GENERAL AND PHYSICAL CHEnISTKY. A . A . NOPES, REVIEWER
A Revision of the Atomic Weight of Nickel. 11. The Determination of Nickel in Nickelous Bromide. BY THEODORE
Geizeral und Physical Chemistry.
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WILLIAM RICHARDSA N D ALLERTON SEWARDCUSHMAN. PYOC. A m . Acad. 34,327-348.-The authors have found that t h e samples of nickel bromide previously used (see this Rev., 4, 27) for determining the ratios NiBr, : 2AgBr and NiBr, : 2Ag contained about 0 . I per cent. of sodium bromide, this contamination having been introduced in the final sublimation of the s a u ples in a porcelain tube. After a fruitless attempt to obtain a pure product by subliming in a platinum-lined tube, the authors decided to make a complete analysis of the slightly impure substance by determining the exact amount of sodium bromide and the amount of nickel present, in the same samples in which the bromine had peen previously estimated. With this end in view it was attempted to precipitate the nickel electrolytically, as had been done by Winkler, but experiments made by dissolving weighed portions of pure spongy nickel and electrolyzing in a platintiui dish showed that the weight deposited was always appreciably greater than that of the nickel originally taken (0,2 per cent. greater when the method of Winkler of drying at 50' was followed), probably owing to the inclusion of mother-liquor and of hydrogen. T h e following method was therefore adopted : the weighed nickel bromide contained in a platinum boat was reduced with moist hydrogen a t a comparatively low temperature, the hydrogen replaced by dry air, and the boat weighed ; the residue was then digested repeatedly with pure water and the bromine in the filtrates was precipitated and weighed as silver bromide. T h e possible errors in this procedure were carefully investigated : thus it was shown by rinsing out the cooler parts of the combustion tube with nitric acid that no nickel bromide was lost by volatilization ; by exposing the spongy nickel to the air that no oxidation took place ; by burning it in air in a combustion tube that no water was produced, and, therefore, that no hydrogen was occluded ; and by qualitative analysis of the water extract that it contained nothing but sodium bromide and some nickel dissolved by the action of water on the metal itself. Making proper corrections for the amount of sodium bromide present, the mean values of the atomic weights calculated from the different ratios determined are as follows : 58.703 from NiBr, : 2AgBr ; 58.704 from NiBr, : 2Ag : and 58.709 from NiBr,: Ni. As the final value based on all determinations, 58.706 is adopted. T h e article closes with a criticism of the work of previous investigators on the same subject. A Revision of the Atomic Weight of Cobalt. 11. The Determination of the Cobalt in Cobaltous Bromide. BY THEODORE WILLIAMRICHARDSAND GREGORYPAULBAXTER. PYOG. Am. Acad., 34, 35 1-36g.-This investigation is closely analogous to the one on nickel just reviewed. T h e cobalt bromide was
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Review of Americaii Chemical Reseawh.
proved to contain about 0.1 per cent. of impurity by reducing it in hydrogen, leaching with water, evaporating, and weighing the residue, this being admissible in this case since the cobalt dissolved by the water is almost all precipitated in the cobaltic form during the evaporation by the oxidizing action of the air. T h e residue was found to consist mainly but not wholly of sodium bromide. T h e final values of the atomic weights derived from each of the ratios determined are : CoBr, : nAgBr, j 8 . g g j ; CoBr, : 2Ag, 58.987 ; CoBr, : CO, j8.998, the final average adopted being 58.995. At the close of the article various criticisins made by Winkler are answered.
Sixth Annual Report of the Committee on Atomic Weights. Results Published in 1898. BY F. W. CLARKE. /. Ant. Chem. Sac., 21, 200-2 14.--The following is a summary of the results published in 1898, the values given by the author in his last year's table being appended in parentheses. Oxygen, Keiser.. ......................... Nitrogen, D e a n . . ......................... Boron, Armitage.. ........................
................
I 5.880 ( 15.879) 14,055 ( 14.04) IO.959 ( 10.928 65.45 j ( 6j.41) 112.377 (111.95) i9.314 (79.02) 12 j 9 ( 127.49) 126.98 (127.49)
Zinc, Morse and Arbuckle Cadmium, Morse and A r b u c k l e . .......... Selenium, L e n h e r ....................... T e l l u r i u m , Metzner .....................
