OCTOBEE 31, 1913] 



SCIENCE 



615 



has never been found. Uranium and therefore 

 radium are found in this country in earnotite and 

 its associated minerals, and in pitchblende. Car- 

 notite is a lemon-yellow mineral, usually found in 

 pockets of sandstone deposits. The mineral may 

 be in the form of light yellow specks disseminated 

 through the sandstone, or as yellow incrustations 

 in the cracks of the sandstone; or may be more or 

 less massive, associated with blue, black or brown 

 vanadium ores. 



Pitchblende is a hard, blue-black ore that looks 

 something like magnetite, but is heavier. It is 

 found in pockets and veins in igneous rocks. This 

 mineral is not nearly as widely distributed as ear- 

 notite. Occasionally it is found associated with an 

 orange mineral called gummite. 



The best way to test these ores is to wrap, in the 

 dark, a photographic plate in two thicknesses of 

 black paper. On the paper lay a key and then, 

 just above the key, suspend two or three ounces of 

 the ore, and place the whole in a light-tight box. 

 Pressure of the ore on the key and plate should be 

 avoided. After three or four days, develop the 

 plate in the ordinary way; and if the ore is ap- 

 preciably radio-active, an image of the key will be 

 found on the plate. 



The XJ. S. Bureau of Mines, 502 Foster Building, 

 Denver, Colorado, will be glad to receive any 

 samples of ores giving promise of containing ra- 

 dium and associated rare minerals, as indicated by 

 the test above described. Though it can not under- 

 take to make chemical analyses or assays of such 

 minerals for private parties, it will indicate the 

 advisability of further examination. 



The Colorado earnotite deposits were ap- 

 parently first noted as far back as 1881, 

 when Andrew J. Talbert mined some of the 

 ore and sent it to Leadville, where it was 

 reported as carrying $5 in gold per ton. 

 This must have been an unusual ore, as the 

 earnotite now found does not carry the 

 precious metal. In 1896, Gordon Kimball 

 and Thomas Logan sent specimens to the 

 Smithsonian Institution, Washington, D. C, 

 and were informed that the minerals con- 

 tained uranium. Shortly thereafter they 

 mined 10 tons of ore, shipped it to Denver, 

 and sold it for $2,700 on account of its 

 uranium content. Three years later, in 

 1899, Poulot and Voilleque collected and 



sent to France specimens which were exam- 

 ined by Friedel and Cumonge, who recog- 

 nized the existence of a new mineral and 

 named it "earnotite," in honor of M. Car- 

 not, then President of the French Republic. 

 In 1900 Poulet and Voilleque leased earno- 

 tite ores at Cashin in the Paradox Valley 

 to extract the uranium. They shortly after 

 completed a small mill in the Mclntyre 

 district, south of the Paradox, and in this 

 project had the cooperation of Jas. Mc- 

 Bride, a mining engineer of Burton, Mich. 

 Their mill ran until 1902 and during that 

 time produced 15,000 pounds of uranium 

 oxide. Thg mill was started again in 1903 

 by the Western Refining Company, but ran 

 only a year. Up to 1904 the mills appear to 

 have been run wholly with the idea of ob- 

 taining the uranium and vanadium from 

 the ore, for no radium was extracted. 

 Shortly afterwards the Dolores Refining 

 Company built a new mill a short distance 

 from the old one, but after running for 

 some years, this mill, too, shut down. In 

 1912 the American Rare Metals Company 

 acquired the mill of the Dolores Refining 

 Company and is now operating it, with the 

 special purpose of obtaining radium from 

 the ores. The first attempt to extract 

 radium in this country appears to have 

 been made by the Rare Metals Reduction 

 Company, under the management of 

 Stephen T. Lockwood, of Buffalo, N. Y. In 

 September, 1900, Mr. Lockwood brought 

 back from Richardson, Utah, samples of 

 earnotite ore and in 1902 he published in 

 the Engineering and Mining Journal of 

 September 27 the first radiographic plate 

 from products of American earnotite. In 

 June, 1902, he received 500 pounds of spe- 

 cially picked high-grade ore from Richard- 

 son, Utah, and in May, 1903, as a result of 

 experimental work on this ore, he incor- 

 porated what was probably the first Ameri- 

 can company to operate a plant to produce 



