MYSTERIES OF RADIUM.

Hauraki Plains Gazette, Volume XXXVI, Issue 4895, 26 October 1925, Page 3

MYSTERIES OF RADIUM.

potent radiations. high-velocity electrons. The mysteries of radium were touched on by Professor Sir. Ernest Rutherford, in an interview at Hamilton (says the .Waikato Times). Sir Ernest Rutherford gave first of all a history of the discovery of radium. . RAYS FROM RADIUM. Investigating the properties of radium shortly, after its discovery> Sir .Ernest Rutherford said that he had found that it produced two different kinds of radiation, one of which had a range of a few. centimetres and was easily absorbed by placing a metal plate in-its path, and one which possessed an extremely high velocity and had remarkable penetrative powers. These he named the Alpha and Beta rays, respectively, and later a third radiation, which was’ called the Gamma ray„ was dis- ’ covered. Investigation established that the Alpha particles, which travelled at a velocity of about 10,00'0 miles a second, were positively charged bodies, carrying two charges. They Were, in fact, hellium atoms. In the course-of their brief life of one tenmillionth of a second, during which they plunged' along the few centimetres of their path, they had a, most interesting career,. As each particle bore two positive electric charges at the time of leaving the exploding ' atom emitting it, it' acquired two negative charges of electrons. It was found that in the course of its motion the particle picked -up electron after electron from the atoms of-the substance through which it passed, only to drop them again and pick up thousands of other electrons until it permanently retained came ' to rest as a normal, helium atom. The Beta rays were;’’ electrons travelling at enormous speeds—they were, in fact, the highest speed electrons scientists had discovered. Artificially’ to produce electrons having a similar velocity by means of a. vacuum tube a pressure of from 3,000000 volts to 4,000,000 volts would need' to be impressed in the .tube. When it was realised that such enormous voltages would be required to reproduce the velocities of the particles shot out from an atom of radium some idea of the colossal forces backup inside jhe atoms could be obtain, ed. The Gamma rays were rays of a particular penetrating kind, and a pressure of about 3,000,00.0 volts would be required to produce them artificially. -This work had never actually L been attempted, tho.uglt there was no reason why it should not be-done successfully. GASES FROM RADIUM. Experimenting, with thorium,, which also possessed marked. radio active properties, it. had been found that a . remarkable gaseous substance possessing pronounced electrical, and radio active properties was given off, and a similar discovery was made .in respect to radium. ..These phenomena could only be satisfactorily explained by hypothesis that-I'adium wias an unstable substance ; that, is, that it pos- ' sessed the tendency to break up into simple .substances. Radium possessed the atomic weight 226, and it was known .that .it ’ emitted an alpha portum;, or. helijim atom, of atomic weight 4, hence the atomic weight, of the remaining’substance, which was shown to . be. .the. gaseous substance, would .be 22/ Bearing ■’in’, mind the view that radium .Was breaking up into alpha- particles, and-the emana- ’ tion or gas, it might expected that the process of; decomposition might —be carried to further stages. This, in fact, was the case, .and it could be shown..that radium was slowly being to lead by the’emission of alpha and beta particles. The rate of decomposition. was such that a given quantity of radium would be reduced.to half values in about 1650 years. By suitable means it could be shown that, radium was produced by the breaking'up of the substance ionium, while ionium was, produced from’ uranium, the parent of the family. . RApiUM AND MEDICINE. The property of radium of emitting a gas, or emanation, which itself, by decomposition, acquired marked radio active properties, was particularly ■ useful. . In practice the emanation from radium could be collected ad bottled in tiny glass tubes which could be used in'the treatment of disease instead of the parent radium iteelf. Thus the loss of the valuable radium would not be risked, and the radium could, be producing further quantities of the emanationwhile the emanation was in use in treating disease. The exact influence * of radium radiations on bodies had been much disputed. He thought, however, that the direct effect was produced by the Alpha or Beta particles plunging into a tissue. However, the Gamma rays were capable of knocking electrons but of atoms into which they passed/ and these electrons would, of course, have the same effect ais the Beta particles. Thus in the treatment of deep-seated disease- the Gamma particles were probably instrumental in producing a number of high velocity electrons in regions to which the ordinary Beta rays could not penetrate. It had been suggested that the value of radium treatment lay in the extremely high local temperature which could be caused by Alpha rays, Beta rays, or electrons released by Gamma rays plunging into tissues. In view of the enormous velocities of those particles, temperatures of 3000 deg. and 4000 deg. centigrade could easily be produced by them.