Radium

“ But science is not rich, it does not dispose of important means, it does not generally meet recognition before the material usefulness of it has been proved. The factories produce many grams of radium every year, but the laboratories have very small quantities. It is the same for my laboratory and I am very grateful to the American women who wish me to have more of radium and give me the opportunity of doing more work with it.
The scientific history of radium is beautiful. The properties of the rays have been studied very closely. ”

“ It might, no doubt, appear still more probable that the energy borrowed from the external medium by radium is one of those still unknown to us, but of which a vague instinct causes us to suspect the existence around us. It is indisputable, moreover, that the atmosphere in all directions is furrowed with active radiations; those of radium may be secondary radiations reflected by a kind of resonance phenomenon. ”

“ The striking discovery was, in 1903, made by the same investigators that the spontaneous luminosity of radium gives a spectrum of a kind never before obtained without the aid of powerful excitation, electrical or thermal. ”

“ Suppose that a layer of very active radium is spread on a metal plate connected to earth, and that the β rays are absorbed by a parallel plate connected with an electrometer. If the rays are negatively charged, the top plate should receive a negative charge increasing with the time. ”

“ Relative activity supplied by the α-ray products of radium. There are four products in radium which give out α rays, viz. radium itself, the emanation, radium A and C. If these products are in radio-active equilibrium, the same number of particles of each product are transformed per second and, if each atom breaks up with the emission of one α particle, the number of α particles expelled per second should be the same for each product. ”

“ This physicist subjected a narrow beam of radium rays to the simultaneous action of an electric field and a magnetic field, the two fields being uniform and having a similar direction, normal to the original direction of the beam. The impression produced on a plate normal to the primitive beam and placed beyond the limits of the field with reference to the source, has the form of a curve, each point of which corresponds to one of the original beam. The most penetrating and least deflected rays are at the same time those with the greatest velocity. ”

“ Now, the special interest of radium is in the intensity of its rays which is several million times greater than the uranium rays. And the effects of the rays make the radium so important. If we take a practical point of view, then the most important property of the rays is the production of physiological effects on the cells of the human organism. These effects may be used for the cure of several diseases. Good results have been obtained in many cases. What is considered particularly important is the treatment of cancer. ”

“ The evolution of heat from radium and the radio-active substances is, in a sense, a secondary effect, as it measures the radiant [Pg 35] energy transformed into heat energy by the active matter itself and whatever surrounds it. Let us repeat, therefore, that the total amount of energy pent up in a single atom of radium almost passes our powers of conception. ”

“ By experimenting, I have found that regenerating rays are contained in super-radium. In fact, my theory is that the regenerating rays and the invisible rays of super-radium are synonymous. Such being the case, when the current of super-radium is turned on by the clockwork, it will flow to Earth and, returning, enter the virator and restore my body to a normal condition, freeing it from the fumes of chloroform and making it capable of receiving its new life. ”

“ The α rays from a thick layer of a simple radio-active substance consist of α particles of 178different velocities, which have ranges in air lying between 0 and the maximum range. The ionization of the particles per unit path is greatest near the end of its range, and decreases somewhat as we approach the radiant source. A complex source of rays like radium gives out four types of rays, each of which has a different but distinct range. ”

“ Radium emits a stream of active corpuscles moving with great speed. Certain of them carry a positive charge and form the Alpha rays; others, much smaller, carry a negative charge and form Beta rays. The movements of these two groups are influenced by a magnet. A third group is constituted by the rays that are insensible to the action of a magnet, and that, we know to-day, are a radiation similar to light and to X-rays. ”

“ More striking still was the discovery of the discharge of heat from radium. Without any alteration in appearance this substance releases each hour a quantity of heat sufficient to melt its own weight of ice. When well protected against this external loss, radium heats itself. Its temperature can rise 10 degrees or more above that of the surrounding atmosphere. This defied all contemporary scientific experience.
Finally, I cannot pass in silence, because of their various repercussions, the experiments connected with the physiological effects of radium. ”

“ During its lifetime, the radio-active atom, slowly disintegrating, pours out a prodigious amount of energy; and in the process apparently is transformed and takes on other characters and qualities. Radium for instance, or rather some products of its disintegration, are thought to take on the characters of Helium and of Lead. ”

“ Radium emits three distinct types of radiation, known as the α, β and γ rays, of which an account will be given later. It produces in addition a radioactive emanation or gas which is about 100,000 times as active weight for weight as radium itself. The emanation released from 10 milligrams of pure radium bromide causes a glass tube into which it is introduced to phosphoresce brightly. A brilliant luminosity is produced in phosphorescent substances like zinc sulphide, willemite and barium platino-cyanide when introduced into a tube containing the emanation. ”

“ Thus a scientist or a doctor unable to procure the metal radium may easily experiment with a bit of wood or glass rendered radio-active—that is, charged by radium emanations, and capable of replacing the original metal as long as the charge keeps its potency. ”

“ I devised a very satisfactory method for determining the quantity of radium by the means of a radioactive gas produced by it and called "emanation." This method, frequently used in my laboratory, permits of the measurement of very small quantities of radium (less than a thousandth of a milligramme) , with a fair precision. More important quantities are often measured by their penetrating radiation, named Gamma-rays. For this we also possess in my laboratory a suitable equipment. It is easier and more satisfactory to measure the radium by the emitted rays, than to weigh it in a balance. ”

“ Science is, at this date, powerless to analyze or explain its marvellous power. The leading scientists of the world of learning—Sir William Crookes, Sir Oliver Lodge, and Professor Curie (who, with Mme. Curie, has the honor of being its discoverer) —believe that in radium will be found the true solution of the problem of matter. Radium gives off rays at the speed of one hundred and twenty thousand miles a second, and these rays offer the most extraordinary heat, light, and power. Yet with this immense radiation it suffers no diminution of energy ”

“ It has been suggested that the radium derives its energy from the air surrounding it, that the atoms of radium possess the faculty of abstracting the kinetic energy from the more rapidly moving air molecules while they are able to retain their own energy when in collision with the slowly moving molecules of air. ”

“ Several have as their aim the study of the emanation, that strange gaseous body that radium produces and which is largely responsible for the intense radiation commonly attributed to the radium itself. Pierre Curie demonstrated by a searching examination the rigorous and invariable law according to which the emanation destroys itself, no matter what the conditions are in which it finds itself. To-day the emanation of radium, harvested in tiny phials, is commonly employed by physicians as a therapeutic agent. ”

“ I must pass rapidly over various other wonders of radium that M. Curie laid before me. New matter is accumulating every week as the outcome of new investigations. Even in the chemistry of radium, which is practically an unexplored field, owing to the scarcity and costliness of the metal, there are various facts to be noted, as these: that radium changes the colour of phosphorus from yellow to red; that radium rays increase the production of ozone in certain cases ”

“ For example, the β rays from radium consist of negatively charged particles projected with a wide range of velocity, and, in consequence, they are absorbed in different amounts in passing through a definite thickness of matter. In each case, only a fraction of the energy absorbed is transformed into the particular type of energy, whether ionic, chemical, or luminous, which serves as a means of measurement.
The rays which are the most active electrically are the least active photographically. ”

“ The -rays or radium show, as it is known, qualitatively the same properties as cathode rays; they are magnetically [7] and electrically [8] deflectable, and they carry an electric charge with them.
In quantitative respects, they are different from the cathode rays even under crude observation, in so far as they have a much higher penetration capability as the other ones. ”

“ Source of the energy. It has been shown that the heating effect of radium is closely proportional to the activity measured by the α rays. Since the activity is generally measured between parallel plates such a distance apart that most of the α particles are absorbed in the gas, this result shows that the heating effect is proportional to the energy of the emitted α particles. ”

“ If radium transforms itself in such a way that its activity does not persist throughout the ages, it loses little by little the provision of energy it had in the beginning, and its properties furnish no valid argument to oppose to the principle of the conservation of energy. To put everything right, we have only to recognise that radium possessed in the potential state at its formation a finite quantity of energy which is consumed little by little. ”

“ Radium Emanation.—The radium emanation is to be regarded as a typical radioactive product or transition element which exists in a gaseous form. It is produced from radium at a constant rate, and is transformed into radium A and helium. Its half-period of transformation is 3.86 days. The emanation from radium has been purified by condensing it in liquid air, and pumping out the residual gases. The volume (26) of the emanation at normal pressure and temperature to be derived from one gram of radium in equilibrium is about 0.6 cubic millimetres. ”

“ They named the new element radium.
The Curies and other scientists were very excited. Here were three elements—uranium, thorium, and radium—all giving off powerful rays. Where did the rays come from? Scientists were sure they could only come from the atoms of the elements themselves. But how could that be? There couldn't be anything smaller than an atom. Or could there? The scientists didn't know. It was a real mystery.
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WHAT'S IN AN ATOM? ”

“ Then it was said that radium disproved much of man's scientific knowledge, but instead of that being so, we electrons have greatly extended man's knowledge by our radio-active actions. If any man believed the atoms of matter to be eternal, we certainly disproved that. Here, in radium, man could see atoms going to pieces. ”

“ The experiments are not easily carried out, except with very intense radio-active sources, because, independently of the absorption by the air, the action upon a given receiver varies inversely as the square of the distance from a source of small dimensions. This radiation, which travels a long distance in the case of radium, comprises rays of the cathode kind and rays which are undeflected ”

“ The luminosity of radium persists over a wide range of temperature and is as bright at the temperature of liquid air as at ordinary temperatures. A slight luminosity is observed in a solution of radium, and if crystals are being formed in the solution, they can be clearly distinguished in the liquid by their greater luminosity.
117. Spectrum of the phosphorescent light of radium and actinium. Compounds of radium, with a large admixture of barium, are usually strongly self-luminous. This luminosity decreases with increasing purity, and pure radium bromide is only very feebly self-luminous. ”

“ A relatively large
fraction of its atoms transmute per second to a solid element
designated Radium A. In turn this new generation of atoms breaks
up—even faster than the emanation—becoming yet another element
with specific chemical properties. And so on for a whole sequence
of transmutations, till finally a stable substance is formed,
identical with ordinary lead in chemical and physical properties,
but possessing a slightly lower atomic weight.
The genealogy of the radium series of elements shows that radium
is not the starting point. ”

“ That is what radium does to that kind of glass. You see, if radium exists in a gram of inactive matter only to the extent of one in ten-thousand million parts its presence can be readily detected by this radioscope, and everything that has been rendered radioactive is the same. Ordinarily the air between the gold leaves is insulating. Bringing something radioactive near them renders the air a good conductor and the leaves fall under the radiation. ”