The Montgomery advertiser., 1903-11-01

different clements. For convenience of reference these are usually designated the alpha (a) the beta (b). and the gamma (g) rays. By proper manipulation the three classes may be sifted and stud fed separately.
 The alpha rays have but little power of penetration, being stopped by a thin sheet of aluminium foil or a few inches of air, or, according to Professor Crookes by a piece of glazed paper or cardboard. The photographic and fiuorescent effects are comparatively slight, but when they strike screen covered with zinc sul- phide they produce a beautiful scintil- lating effect Hike stars in a black sky" when viewed with a microscope. In or der to show this effect. Professor Crookes has invented a little instrument which he calls spinthariscope. It consists of magnifying lens. a zinc-sulphide screen and a movable index to which Is attached a little particle of radium bromide. In order to see the scintillations 1t is nec- essary to exclude all light from the eye for few minutes, to rest the nerve and expand the pupils. At first 1t was thought that the alpha rays were not affected by a magnet, but Professor Rutherford of Montreal, has recently proved that they are slightly defiected by O powerful mag net and in a direction which indicates that they carry a positive charge and are moving with a velocity approaching that of light He concludes from this that they are positive ions. similar to the cathode affiux of the Crookes tube. But he has measured the relative mass of these ions and finds 1t to be not more than 1 per cent of the atomic weight of the element. It would seem from these haa ofN Nf radtayun a re dissociated into smaller atoms of a diff ferent substance. probably helium, and that these smaller atoms give off one or more electrons and thus become positive ions, or co-electrons, and that these ions and electrons are hurled into space with tremendous velocity.
 The Beta rays are far more penetrat- ing. being able to pass through glass or several inches of metal and still affect a photographic plate or illumine a fluor- escent screen. They are readily de1ected by magnet, carry a negative charge, and, in all probability, are the same as the electrons of the cathode rays. l. e., negatively charged corpuscles. much smaller than atoms and moving with the velocity of light.
 The third class, or gamma rays. be- have in every way like X-rays, having great penetrating power, producing strong fluorescent and photographic effects, but not in the least affected by a magnetic or electric field. They are evidently ether effects and probably produced by the collisions of the Beta rays or cleo irons. with the massive atoms or mole culAs of the substance. All three classes of rays have strong ironizing effects on the air through which they pass, mak- ing 1t a good conductor of electricity. This furnishes the most sensitive and perhaps the most accurate test of the presence and the strength of the Bee querel rays. It ie estimated that a sen- sitive electroscope. such as used by the Curies. will detect in one minute an amount of matter thrown off by a ra- dio-active substance which would need to accumulate for two million years before it could be detected by the most sensitive chemical balance
 Beside these three classes of radiation proceeding from all radioactive sub stances, there is, at least in the case of radium and therium, a sort of gas- eous emanation, forming an atmosphere about the substance and occluded in its pores, which has the power of imparting temporary activity to other bodies with which it comes in contact. It can be driven off by heat or drawn off with a current of air and wherever it comes in COHldtL WilU d IuOTtSCeHt SuDSIHnC6 makes 1t glow. showing that 1t is itself radioactive. but only temporarily so, since it loses it's power in a few days or at longest in few weeks Its chem ical composition Is unknown, but 1t be- hayes like an inert gas such as helium or argon, forming no combinations with other elements. Passing it in tubes through liquid air 1t disappears at a tenn perature of about -250 degrees Fahren- l<Ek los. does not pass on with the carrying gas as is shown by the lack of luorescence in the tube beyond. But 1t Is in such inconCcivably small quantities that nc residue can be found. nor can it be de- tected in any other way than by its ra- dio-activity. It Is. perhaps, the remnant of the radium atom after the eIectrons and coelectrons have escaped.
 Theoretical Importance of Radium.
 These, then are the peculiar properties of radium that it emlts constantly and without apparent diminutionfi and with out apparently receiving energy from any external source or decreasing in weight at all temperatures and from all it's com pounds, whether in solid form or in solu- tion these three classes of rays which aye capable of penetrating dense and opaque matter. producing photographic lumines- cent and electric effects. and maintaining a temperature of about degrees Fahr above that of surrounding bodies. And these are certainly interesting properties but the interest is largely from the theo- retical standpoint due to their bearing upon our present ideas of matter and en- ergy It Is not the mere fact of radia- tion. for all bodies are constantly radiat-
 ing energy In the form of heat rays. II is not the mere fact that these substances glow in the dark with a dull phosphores- cent light. for many other objects do the same. notably the glowworm, the flrefy animalcules in water many of the mis- croscopic plants known as bacilli decay ing wood and fish. Nor is it because these radioactive substances throw off invisi- hle material particles for every volatile solid and liquid is constantly sending forth such particles into the air. Nor Is 1t due to the fact that these particles thrown oT do not seem to diminish the mass or weight of the hody. or that they cannot be caught and weighed and anal yzed Ike other forms of matter, for the same is true of all scents and odors. Ce- dar and sandalwood and musk give out their fragrance for years without appar- ent loss of weight Nor is the interest