CHEMICAL ELEMENTS.

New Zealand Herald, Volume LXVIII, Issue 20925, 15 July 1931, Page 13

CHEMICAL ELEMENTS.

PLACE OF " INERT » GASES. REVOLUTIONISING THEORIES. "The discovery of rare gases which would not combine with others caused the greatest excitement in the scientific world/' said Professor F. P. Worley, professor of chemistry at the University College, in a lecture Inst evening pn "Drones Among the Chemical Elements." The speaker pointed out that the remarkable discoveries of previously unguessed elements during the nineties, beginning with argon, had marked the dawn of a new scientific era in a period of stagnation. There was a possibility, Professor Worley added, that new discoveries would bo made. If this came about, though it was not expected;' all chemical theories would be revolutionised. Science's list of elements was complete, but it had to be remembered that it was considered as such when Lord Eavleigh and Sir William Ramsay added argon to the elements when they detected a difference between the weight of the nitrogen of the air and that of chemical nitrogen. Actually, this disparity had been observed by the Hon. Henry Cavendish in 1789, but his note had been overlooked by chemists. Argon was an "inert" gas, and, in using the expression "drone" to describe such an element, the intention was to indicate that it did not react with other elements. Helium, the second lightest of the elements, was discovered when it was suggested to Ramsay that gases given off from minerals should be examined. It was Lord Rutherford who was able to establish that helium came from radium and that alpha rays were actually helium with two positive charges, or electrons. There was now a strong supposition that all helium was produced from radio-active substances. Apart from nitrogen and oxygen, air contained nearly 1 per cent, of argon. Other "inert" gases which were isolated after the discovery of this element occurred in minute degrees, neon being one pari in 80,000* parts of air, helium one in 250,000, krypton one in 1,000,000 and xenon one in 11,000,000. Nitron, an element associated with radio-active substances, was eight times heavier than air. The lecture was illustrated by lantern slides, showing the uses of "inert" gases in commercial lighting.