MARVELS OF MATTER

Taranaki Daily News, Volume LVI, Issue 90, 11 September 1914, Page 6

MARVELS OF MATTER

GREAT SCTEXTCST'S THEORY. STRUCTURE OF~THE ATOM. STIUKIXU GEXERALISATIOXS. The eminent visiting scientist, Sir Ernest Rutherford, who began his remarkable career at Xelson College, and is now virtually the pioneer and the foremost investigator of the great subject of radio-activity, lectured last week at the Town Hal!, Wellington, before a huge audience. He explained with much clarity a subject with which the great majority of his hearers had only vaguely concerned themselves, and he also demonstrated some remarkable experiments.

Though its title was 'The Transformation of Matter, and the Structure of tiie Atom," the lecture was almost wholly concerned, with radio-activity, hut entirely with the purely bckntilic aspect of the subject. It had no refcrenv,-, .':::■ to the njedical use of

radi.im or to any of the more picturesque attributes which have been made familiar to the public. The scientest began with a general dissertation on the. changed conceptions in recent science of the constitution of matter, and on the general acceptance of the theory that the atom is a thing permanent, unchangeable, indestructible, and inJivisabk'. The lecturer proceeded to say that scientists had concluded that the atom was, nevertheless, a very complete structure. He described the discovery of the "electron," the extremely minute particles assumed to be merely unit charges of electricity, discharged from various bodies in certain condition.!. From this point, there had arisen the theory that the whole of the atomic structure was electrical, and that all matter was really only a complex arrangement of electricity. DEGEXERATIOX OF RADIUM.

Doling specifically with radium, Sir Ernest Rutherford entered into particulars of its genesis from uranium and its degeneration to a stage which suggested that, ultimately, though this "point was still under investigation, it became lead. He explained that in 2000 vears one half of any bulk of radium become* broken down, and in another similar period half of the remainder also goes, so that ultimately none would be left. The inevitable necessity for a source for the existing radium being discovered as its iirst parent, and the '•life" of uranium as a stable hodv, had been determined as 4,000.000.G00 'yours. 'ln the reverse direction, he showed •how the degeneration processes went on ■with the promotion of various more or less stable bodies, and the release relatively enormous quantities of energy. One pound of the gas "radium ompaiion," the first product of the breakingdown process, would give out the equivalent of 00,000 horse-power for one day. 'PARTICLES OF RADIO ACTIVE MATTER.

'Succeeding this portion of the lecture, ■Sir Ernest exhibited lantern slides to illustrate some of the remarkable experiments which had been undertaken for Die purpose of counting the particles thrown oil' during the changes in radium, and described tile wonderful mstru■ments by which these ]>»rtieles, far too small to be seen by the most powerful microscopes, can be actually counted with considerable accuracy. One of these instruments, the, "string elcctro.meter," was devised by Professor 1-ttby, of Victoria College. Wellington, and Wir Ernest Rutherford, with Professor ■Eaby's assistance, gave an actual and very striking demonstration of the passage of both "Alpha" particles and electrons from a specimen of radio-active material.

This was, he said, an exceptional demonstration. It had been given only once in London, and once in Washington. The fact that the particles could, by scientific methods, be counted, and that .their relationship to the material concerned was known, the lecturer said, enabled the number of atoms in a body to he calculated. For instance, one cubic, centimetre of t'u gas "Helium," was found to contain -:J;,-liKl.(>no,WlO,of)o,-.000 atoms, a number which was inconceivably large.

Tilt: STUIXTUUE 01" THE ATOM. Sir Krivst then entered on a discussion of the structure of the atom, a matter wbieh, lie said, was especially interesting him at present. He su"-««st-ed, roughly, that Ids' investigations showed that eaeli atom consisted of a nucleus and of a number of accompanying electrons. Accepting that the nucleus consisted of a positive electrical charge of so many units—since electrons were always negatively charged—there must be as many electrons as there were units in the nucleus to give neutral electrical condition to the whole, atom. If the atom were magniliol until the nucleus were the size of a list, then the outermost electrons might be a mile or two away. The actual arrangement of the electrons and the form and properties of the whole atom appeared to be governed by the dimensions of the charge of the nucleus.

MUCH WOliK VET TO TIE IXIXE. The lecturer said that the atom was thus in itself a great system, anil that (he nucleus was exceedingly small compared with the atom, and further, that the nucleus was again a great system, held together by forces o'f tremendous intensity, and probably responsible for gravitation and for the radio-activity of certain bodies.

"We have been able, to penetrate the structure of the atom by means of the study of the high speed projectiles," concluded Sir Ernest, "but we have no means of penetrating the nucleus. There is still an enormous amount of workto be done before we can understand thoroughly the structure of the atom, and so of the whole of the material world."