RADIUM.

Auckland Star, Volume XXXIV, Issue 171, 20 July 1903, Page 4

RADIUM.

An unprofessional opinion uport a' purely scientific subject is generally worthless, and we do not presume to rush in where the most eminent scientists of the day hesitate to tread. But there is something so fascinating about the problems raised by recent investigations upon radium that we may be forgiven for making a few comments upon them. Radium, as is now generally known, is an element which has not yet been discovered in a pure state, but is found in pitch-blende to the extent of about one gramme (151 grains) to the ton. The story of the discovery of this new substance by M. and Mrue. Curie, following the line of M. Becquerel's work has been frequently told. The impor(ant characteristic of radium is that it is strongly radio-active —in other words, that it gives ofV rays that are

( apparently electrical in nature. It is I now admitted that, radio-activity is a I phenomenon that occurs to some small I degree in conjunction with most known j substances. But one peculiar property jof radium is that its power of radioactivity is 100,000 times greater than i that of uranium, one. of the most poweri fill radio-active substances known. In j tho second place—and this is one of the i most astounding facts in connection with ! tins mysterious substance —"despite the continual energy that it displays it has ! not been found to experience any variation over a period of several years, nor apparently does the quality of its light alter." Lord Kelvin agrees with M. Becquerel that there is no calculable loss of weight in radium through these manij feshitions of energy. M. Becquerel believes that he has proved that from [every square centimetre of the substance j (about 1-0 square inch) there is a loss I that would amount to only one milli- ; gramme (1-05 grain) in 1,000,000,000 years. Ab the same time M. Curie has shown that radium, while glowing constantly with a pale blue light, continuously maintains its own temperature at about 2.7 Falir. above, its surroundings, "without combustion, without chemical change of any kind, and without any- change in its molecular structure." The remarkable character of these phenomena may be indicated by Lord Kelvin's observation that radium threatens "to overthrow the law of the correlation of force." An article in the '•Engineer.' , dealing with this subject remarks: "We shall not go so far as to say that the discovery strikes at the whole theory of the conservation of energy, but it does lead to the belief that on this, as on various other physical laws, it may be necessary to reconsider our position. If it be really true that something exists that can give heat—in other words, do work—indefinitely, we get a new view of the universe." The law of the conservation of energy —that no manifestation of energy can be produced without the antecedent expenditure of energy in some other form —lies at the foundation of all scientific theory, and a discovery that appears to cast some doubt upon the universality of this law may well bo regarded as one of the most astonishing results that modern science has yet attained.

It is not easy to give in simple language any adequate idea of the enormous energy exerted by this innocent-looking ■white crystalline powder. Three types of rays emitted by it have already been distinguished. One class is closely akin f.o the Rontgen ray, another has been proved to pierce 3ft. of iron without serious loss of intensity. Professor Rutherford, the young New Zealander who has already won scientific fame by Ills investigation of radium, states that the rays would pass through 150. centimetres (5 feet) of water before they lost one per cent, of their power. The manner in which this energy is dissipated has been revealed in certain experiments made by Sir William Urookes, in which sensitised screens exposed to radium appeared to be "bombarded" with a constant shower of minute atoms, "splashing" upon it like rain drops Jn a pool. Thess emanations are the ''electrons." whichj without omitting light, are constantly dashing off from radium into r.paco at the rate of about 120,000 miles a second. "A radium electron,"

says Professor Pegram, "sent in chase of a 'Mauser bullet would pass through it as if it were standing still." Rays that can photograph through three feet of iron must possess intense force; and even in small quantities radium is a dangerous substance to deal with. The radium rays soon cause suppurating sores on human flesh exposed to them, but this is not astonishing when we learn from Sir W. Crookes that one gramme (154 grains) of radium contains enough energy to lift the whole of the .British and French fleets combined to the top of Ben Xevis. Already the achievements of radium read like a page from the •'Arabian Nights/ rather than a record of sober scientific observation. But as it costs about £20,000 per ounce, and there are only about two pounds of it ill existence, it will be a long time before it can be put to any practical use.

The attempts hitherto made to account for these marvels are of course purely tentative. Professor J. J. Thomson, of Cambridge, and Professor Rutherford seem to have established the theory that the most penetrative radium rays are composed of electrons moving with about the same speed as light. These "electrons" are the minor particles into winch, according to the latest hypothesis, all the atoms of which matter consists are subdivided. Inside the atom large numbers of these electrons are constantly whirling about, and in some obscure way the strange properties of radium may be due to this "subatomic" movement. To account for the heat generated M. Curie has to assume that '"'radium utilises an external energy of an unknown nature." Sir Oliver Lodge thinks that as the '•'electrons" emitted are ; on Professor Rutherford's theory, electrical atoms, and they cannot always penetrate the obstacles they meet, the consequent shock causes a rise in temperature in their proximity. Sir Willia?!! Crookes believes that radium

'■replenishes its energy from the movements of the molecules or atoms of air surrounding it." But we need not deal further with these highly technical conjectures, on which even scientific experts cannot yet speak with authority. It may interest our readers more to note that the radium ray is already declared to have cured a case of cancer. The fact that the Finsen ray is now recognised as a cure for lupus and other rodent ulcers, and that the Rontgen ray has been used in conjunction with it, may

assist us to believe that the kathode ray of radium may also possess some curative power. Lord Kelvin has already expressed an opinion to this effect, and if it turns out to be well.founded, not the least wonderful property of this strange substance will be its power of reducing tha great sum of human pain and misery by the extermination o£ some forms of hitherto incurable disease.