PERPETUAL LIGHT.

New Zealand Herald, Volume XXXVII, Issue 11533, 19 November 1900, Page 3

PERPETUAL LIGHT.

TO THE EDITOR. Sir,—Under this heading you quote an article from the San Francisco Examiner, relating to' the discovery, or, rather, isolation, of Radium, which in one or two respects conveys, I think, a wrong impression of the methods of, modern scientific research, and does scant justice to the many other workers in the same field besides M. and Mme. Curie, who have just succeeded in separating the radio-active principle in pitch-blende from the rest of the mass. But though the credit of the actual separation belongs to M. and Mme. Curie, they would be the last to assert that where others " left off about a year ago they took up the work," for, in truth, others have never left off, and the investigation of the radiations of Uranium, Thorium, Polonium, and Radium has been carried on with the greatest activity and by a host of workers, prominent amongst whom have been Professor J. J. Thomson, Monsieur and Mme. Curie, Professo; Becquerel, Professor Ernest Rutherford (now of McGill College, Montreal, but formerly a student at Canterbury College), Professors Zeleuy, Elster, Geitel, Dr. Larmor. etc., etc. To these, as well as the Curies (for there are both husband and wife), we owe our knowledge of the interesting radiations given off by these radio-active substances, as they are called. But their object in prosecuting their researches was not to discover a source of perpetual light, even if such bo possible, but to explain certain phenomena which were found to exist; in other words, to search more deeply into the hidden mysteries of nature. Quite recently a gentleman asked Professor Rutherford in my hearing, " And what is the use of all this?" and the reply which was given showed, I take it, the spirit which should actuate every scientific man : "No use at all: I should not be happy if I thought I was doing anything useful." The energy which scientific men throw into their work is in no way measured by the prospect there may be of turning the result of their labours to some commercial account. Indeed, they seldom reap such commercial advantage when it docs come. Wireless telegraphy is primarily due to the labours of Faraday, Maxwell, and Hertz, but Marconi has gathered in the harvest. Rontgen photography is not a patented process, though it very well might have been,', and from what" I know of Monsieur and Madame Curie's work I am confident that in their investigations with pitch-blende they were merely seeking to separate from it the radio-active substance, which was known to be 100,000 times more active than any body previously examined, on which account, though only just isolated, it has for several years been known by a separate name, Radium." That radium, when so separated, should happen to be so radioactive as to be self-luminous, and, therefore, possibly of commercial value, is an accidental circumstance, Professor Rutherford and the rest would say, which cannot be helped. But I do not think that the separation of radium and the discovery of its self-lumin-osity is the most interesting or most valuable part of the researches which have led up to it. One of the most curious effects of these bodies—and the same is true of ultra-violet, light and Rontgen rays— that they cause a negatively-electrified and insulated body to lose its electricity, if it be exposed to their emanations, and up till last year, when the British Association met, there was much uncertainty as to how this occurred. At that meeting, however. Professor J. J. Thomson explained the whole thing by one of the most refined and beautiful investigations it is possible to conceive. Ho showed (and if anyone care* to see his paper it is to be found in the Philosophical Magazine, either quite late last year, or early this, and is on " Masses Smaller than the Atoms") that the presence of these bodies caused what had hitherto been regarded as the smallest possible mass which could exist, namely, the atom, to break up into two very unequal parts, of which the smaller is about one-thousandth of the mass of the hydrogen atom, and no matter what the gas might be surrounding the charged body, i.e., whether it was hydrogen, oxygen, chlorine, or anything else, its atom was broken up in this way, and the smaller part was always the same size, and, furthermore, always carried the same electrical charge. In other words, that it is possible by means ot the radiations from these radio-active bodies to break off something from the atoms of two different elements, and the bits thus broken off are the same, not as the atoms from which they came, but as each other. Professor Rutherford has since shown that the same amount of energy is required to break the piece off whatever kind of atom it may be broken off. So hero apparently we have something fundamental, and while we cannot at present convert silver into gold, we can get something from both which is quite different from either, but the same, whether it comes from silver or gold. The remarks of the San Francisco Examiner about the upsetting of our ideas about light and energy, by the isolation of radium, are amusing, though scarcely true. The conservation of energy is the bedrock of physical research. I am, etc., C. Coleridge Farr.