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Show MARVELOUS POWER OF RADIO-ENERGY Shown by Utah Minerals on Photographic Plates The great interest taken by scientists, and tho world in general in the newly discovered and wonderful substance, radium, has caused much experiment, and at the request of The Tribune, I herewith give the results of a number of tests made on photographic plates, with the uranium minerals of Utah. So far as I am informed, we have four mineral compounds In this State, which show the radio-active energy. Carnotite. Carnotltc is found much more abundantly abun-dantly than any of the other uranium minerals, In the sandstone measures of Emery, Grand, and possibly other counties, coun-ties, the other uranium minerals occurring occur-ring so sparingly as to be of little use beyond cabinet specimens. Carnotite occurs as a yellow crysta-line crysta-line powder intimately mixed with quartzoso sand, and after sepai'atlon from the silica, Is found to be composed of approximately vanadium oxide 20.12, uranium oxide 63,54, potassium 10.37, and water 5.95. Taking about two ounces of the pulverized material mixed with the sand just as It came from the mine, I Ullcd a circular tin box cover evenly full, and covering It with tissue paper, pasted the paper about the edge of the cover for convenience In handling. A photographic glass plate was then taken In the dark room and placed sensitive sen-sitive side up' in a light tight pasteboard paste-board box.. On the sensitive side of the plate, various flat metal objects were placed with tissue between the pieces of metal and plate, and over the metal pieces, the tin box filled with powdered carnotite was then carefully placed with the paper cover facing the metal objects, and the whole covered and put in another covered box for about forty-five forty-five hours. The plate was then developed with the ordinary photographic developer, and the result Is shown in the accompanying cut. On developing the plate, the effect of the radio-energy is seen In a circular spot, blackened, except under the metal objects, as shown In the cut, and on printing from the negative so obtained, the metal pieces are shown In various shades from gray to black. It will be noticed that the circular piece of copper Illustrated In center of cut. Is black, showing no penetration of radio-activity for the time of exposure. The two triangular pieces were aluminium, alumi-nium, and show somewhat less resistance resist-ance to the wonderful power, tho substance sub-stance acting through this metal far more easily than through the copper, which Is even penetrated by the stronger compounds of radium. The remaining three objects were cut from ordinary tin, and also show that the radio-activity penetrated them, but possibly to a lesser extent, than through the aluminium, all of the pieces of metal being of nearly the same thickness. Tho carnotite will doubtless affect a photographic plate in less time than twenty-four hours, but In order to get Hp jjB an effect sufficiently strong to make a photographic print, a longer exposure, or more mineral would be necessary. The carnotite used In this experiment, has been used repeatedly In a similar manner for several months, and seems to sustain the claim that loss of radioactivity radio-activity is practically inappreciable. Autunite. The uranium mineral next In abundance abund-ance In the State, is possibly autunite, found In the mineralized sandstone of Silver Reef. It occurs in small tabular greenish yellow crystals on sandstone, and Is a hydrous phosphate of uranium and calcium. A small specimen was placed on the sensitive plate for about three days, which on development was found to be considerably blackened by the radio-energy. Zeunorito. A very few specimens of the rare uranium mineral zeunerlte, were ob-talned ob-talned some time ago, from the Tintlc dlctrlct this being the only locality known in the United States for this mlneraL It occurs with exceeding rarity rari-ty in small square thin tabular crystals, ranging In color from greenish yellow to a fine olive or apple green, and In composition Is an arsenate of copper and uranium. A specimen showing the largest crystal seen, less than a fourth of an Inch across, was placed on the sensitive plate, and after an exposure of three days, the plate was seen to be plainly affected, giving evidence of strong radio-activity. TJranlnite or Pitchblende. The fourth uranium mineral, uraninite, urani-nite, reported as occurring in Weber county, I have not been able to obtain, but It is said to occur in exceedingly limited quantity, In fact so limited, as to be of no importance, for any use. The curious phosphorescent limestone from the Wasatch range, which shows a streak of reddish luminescence when scratched with steel, gave no result on the plate after several days exposure, and the phosphorescent zinc blende from the Horn Silver mine, which gives such a brilliantly luminous streak when rubbed with steel also gave no result after several days exposure. A piece of mica containing A large amount of magnatite between the folia, was placed between the carnotite and plate for several days. The minerals offered but slight resistance to the radio-energy, and the plate was quite evenly blackened through the mica. A small celluloid negative exposed also between the carnotite and the plate, showed an appreciable resistance to the material, mainly In parts most heavily covered with the sliver deposit. Of possibly still greater Interest, are the experiments of Messrs. Kunz and Baskervllle of New York city, with the effects of bromide of radium on various vari-ous minerals and gems. Certain diamonds, dia-monds, the beautiful new variety of spodumene. kunzite, and wlllemlte, wero found to be particularly susceptible suscepti-ble to the Influence of radium, all of these, as well as other minerals showing show-ing beautiful luminescence In a darkened dark-ened room, on exposure to the influence of bromide of radium for a short time. To the best of my information, radium seems to be usually associated with uranium, hence it is suggested that tho prospector be supplied with a small fpool of Kodak film, a few hydrochlno developing powders, a little hyposulphite hyposul-phite of soda, and a cheap pocket ruby lamp, would be ablo to detect the presence pres-ence of uranium In ores with tolerable tertalnty. It would only be necessary to place a little of the pulverized ore to be tested, on a piece of paper, and then on tht sensitive side of the film, allowing al-lowing the whole to remain in a dark box for four or live days. On developing develop-ing the film, the appearance of black spots on it would possibly give a fair Indication of the presence of uranium. MAYNARD BINBY. |