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Remarkable Experiments With New Chemical Metal. MOST OOSTLY OF SUBSTANCES, X Ray Pictures Taken Without X Ray Apparatus by Scientists of the Massachusetts Inestitute of Tech nology—Curious Properties of This Rare and Wonderful Metal, Curious and Interesting photographs —or shadowgraphs, as they might bet ter be called perhaps—taken recently in the photographic department of the Massachusetts Institute of Technology at Boston illustrate the properties of the new chemical metal radium, one of the so called radioactive salts which have recently startled the scientific world by demonstrating that an X ray picture can be taken without the X ray apparatus, says the New York Mail and Express. This remarkable metal, which takes the form of powder and is one of sev eral similar agents obtained by a series of delicate chemical operations from the mineral pitchblende, gives out rays having many of the characteristic properties both of the cathode and the X ray. They pass through substances ordinarily impervious to light, and the pictures taken with them are therefore practically identical with those taken by means of an X ray machine. Radium is the most expensive of all known substances, its value being liter ally many thousand times its weight in gold. A single pound of it, if such an amount were obtainable, would per haps be worth well over $1,000,000. In the few grame of powder used in mak ing the institute pictures, for exam ple, there is only about 1 per cent of the substance that actually produces the picture taking ray, this small quan tity being so powerful, however, that satisfactory negatives can be secured even with so short an exposure at fif teen seconds, and in the opinion of sci entists who have been investigating its Properties ita power is practically in exhaustible. Taking a picture with radium is a much simpler matter than taking one with an X ray machine. The powder is kept im a small box not unlike the cases in which the old fashioned da guerreotypes were framed, with an in ner cover of thin celluloid to hold the precious substance in place when the box is opened and its invisible power turned in the direction of the object to be photographed. The radium itself is a harmless looking yellowish powder, that can be seen to glow dimly when the eye of the operator has become ac customed to the surrounding darkness. But the photographer must work in absolute darkness, for the seemingly magic rays, although they have slight illuminating power, act upon a photo graphic plate much as sunlight does. The picture making mechanism con sists simply of a sensitized plate and the little box of radium, the article to be photographed being placed between them, either in direct contact or with an intervening space of a few inches. As with the X ray, the power of radium varies with its distance from the object photographed. The nearer the metal is held to the object the clearer is the impression and the short er the time necessary to secure good results. Various theories have been propound ed as to the source of the power of this powder to penetrate substances opaque to light. One theory is that radium sends out countless rays of very short wavelength, which are but little obstructed by cloth, paper, cellu loid, flesh and some other substances, but cannot pass through such denser media as metals, wood or bone with anything like the same rapidity. An other supposes that radium is contin ually throwing off little invisible bits of matter, smaller than the atoms which were so long considered the lm it of material divisibility. Indeed it is necessary in this case to think of an atom as divided into two parts, one charged with positive and the other with negative electricity. In explana tion of the radium photograph one must further picture that these in finitesimal particles, hurled into space by the chemical, pass through certain substances and splash, as it were, against the sensitized plate, which they thus affect everywhere except where their passage is retarded by the denser media. The result is of course that the outline, or shadow, of the more opaque portions of the object in terposed appears in the negative, its darkness being in proportion to the resistance offered to the rays. Radium apparently keeps its curious property indefinitely, the storing up process being as mysterious as the dis appearance of the genis in the Arabian Nights’ entertainments into his copper cylinder. Among the pictures taken by the photographers at the institute is one made with nitrate of uranium, an other of the chemical substances pro ducing rays that have the peculiar penetrating power, although in a much less degree than the radium especially prepared for the purpose. The nitrate of uranium used to obtain this negative had, it so happened, been stored away for years. But the result was a very fair outline picture, though it was not so clear as those made with the radium and required a longer exposure.
Newspaper Details
Deland Weekly News
Deland, Florida, US
Fri, May 08, 1903
Page 4
Full Page
Clipped by
Charlie H.
USA 05 Feb 2026
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