The American Journal of Science

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J.D. & E.S. Dana, 1900 - Science

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Page 61 - Of late, petrographers have begun to demand, with considerable reason, an arrangement "which shall bring the essential chemical features — both the percentage figures and the molecular ratios — prominently and compactly before the eye, so that the general chemical character and the relations of the various constituents may be seen at a glance.
Page 170 - The object of the present work is to insist on a directly contrary proposition, namely, that science is in reality a classification and analysis of the contents of the mind ; and the scientific method consists in drawing just comparisons and inferences from the stored impresses of past sense-impressions, and from the conceptions based upon them. Not till the immediate sense-impression has reached the level of a conception, or at least a perception, does it become material for science. In truth, the...
Page 144 - The body called carnotite is probably a mixture of minerals of which analysis fails to reveal the exact nature. Instead of being the pure uranyl-potassium vanadate, it is to a large extent made up of calcium and barium compounds. Intimately mixed with and entirely obscured by it is an amorphous substance — a silicate or mixture of silicates — containing vanadium in the trivalent state, probably replacing aluminum.
Page 452 - ... a process which can hardly be depended upon unless managed with extreme care. In the experiments to be described this difficulty was avoided by performing the filtering and weighing upon asbestos in a perforated platinum crucible. The method of conducting a determination was as follows : A suitable quantity of a standard copper sulphate solution was run from a burette, diluted to a convenient volume, a few cubic centimeters of a saturated solution of ammonium bisulphite added, and the copper...
Page 128 - Hydraulic on the Dolores River. This deposit is in the La Plata sandstone, according to Doctor Spencer's observations, and has been more extensively exploited than any other seen. The sandstone, which at this point is nearly horizontal, is cut by an east- west fault, the fault plane dipping north at about 70 . The amount and character of the throw could not be determined. It is probably less than 50 feet. The carnotite occurs in the hanging wall of the fissure as small irregular branches in a loose...
Page 320 - Ward, LF 1900. Status of the Mesozoic floras of the United States. First paper: The older Mesozoic. US Geol. Surv., 2Oth Ann.
Page 129 - ... would show if it could be followed inward from the surface. A few hundred pounds of picked carnotite ore has been shipped from this claim and is reported to have sold for $1.25 a pound in Denver. This deposit is similar in character to others examined, except that in this case a well-defined fault has provided a zone of crushed and porous rock in the hanging wall, along which impregnation could take place. A few hundred feet farther west the crushed sandstone adjoining the fault has been impregnated"...
Page 129 - ... district, but I have no personal knowledge of these occurrences. It seems highly probable that the material will be found widely distributed in the Mesozoic sandstones of western Colorado and eastern Utah, although perhaps nowhere in very extensive bodies. ORIGIN OF THE DEPOSITS. That the bodies of carnotite and roscoelite were formed subsequently to the deposition of the sandstones is evident from the facts presented in the preceding pages. It is equally plain that the minerals could not have...
Page 359 - Bornemann does not recommend this process as an accurate analytical method. Classen describes a method for the separation of metals as oxalates by adding to the solution of the salt of the metals a dilute solution of the potassium oxalate (1 : 6) and concentrated acetic acid to 80 per cent of the total volume. Regarding copper salts in particular, Classen states that precipitation takes place only in dilute solution and then not completely. It has been the experience of the writer, that the precipitation...
Page 144 - As \et (1900) these highly vanadiferous sandstones have been found only at Placerville, where it is intended to work them for vanadium. Carnotite is associated with them in only trifling amount. Other sandstones noticed owe their bright green color to chromium. In yet another case where the color was dull green this was not due to either chromium or vanadium.

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