INTKA-ATOMIC ENERGY. 279 



Section S. — In tra-atom Ic chemical reactions producnuj the di>i>i<jclatk»i 



of matter. 



Ill examining the properties of radio-active bodies wc reached the 

 conclusion that the radiations they produce come solely from the 

 energy furnished b}' the atom where it is found in a state of enormous 

 condensation. Tlie radiating particles would then be a product of a 

 disintegration effected in the very interior of the atom. 



This disintegration, however, necessarily implies a change of eijui- 

 librium in the arrangement of the numerous elements that compose 

 an atom. Evidently it is only by passing to other forms of equilibrium 

 that it can lose its energy, and consequentl}^ cause radiations. 



The variations of which it is, then, the seat, differ from those with 

 which chemistry is acquainted by this fundamental particular, that 

 they ai'e intra-atomic, while the ordinary reactions affecting only the 

 architecture of groups of atoms are extra-atomic. Ordinary chemistry 

 can onh" vary the arrangement of the stones that form an edifice. In 

 the dissociation of atoms the materials of which the edifice is con- 

 structed are themselves changed. 



We are ignorant of the mechanism by which this atomic disaggre- 

 gation is effected, but it is quite clear that it implies conditions of a 

 special kind necessaril}' very different from those hitherto studied by 

 chemistr3^ The quantities of mattei- involved are infinitely small and 

 the energy liberated is extraordinarily great, which is the opposite of 

 what occurs in our ordinary reactions. 



We have always maintained " that there is an analogy lietween the 

 phenomena observed and those peculiar chemical reactions that pro- 

 duce phosphorescence. These reactions take place between bodies of 

 which one, in infinitesimal proportions to the other, probabl}" acts by 

 connnencing a dissociation. Sulphate of quinine, for example, is not 

 radio-active. By allowing it to' become hydrated after desiccation it 

 shows radio-activity as long as the hydration lasts. Mercury and tin 

 present but .slight traces of radio-activity under the influence of light, 

 but by adding to the first of these bodies a small portion of the second 

 its radio-activity soon becomes ver}^ intense.* 



«See especially Comptes rendus de I'Academie des Sciences, April, 1900, ]>. 892, 

 and Revue Scientifique, Ai>ril, 1900, p. 452. 



&Zffl variabilite des esp^ces chimiques (Revue Sclent ilique, Dei-emher 22, 1900). 

 In the bulbs of incandescent lamps it is noted that the incandescence is no longer 

 produced if the j)r( )iiortion of oxide of cerium added to the oxide of thorium is less 

 than 1 percent. Armstrong and Auer admit that tlie incandescence is due to an 

 oscillatory oxidation — that is to say, one that is alternately produced and extin- 

 guished. When oxidated the cerium might (^)mbine with thorium, when there would 

 soon l)e decomposition, then reoxidation and cond)ination, and so on. These reac- 

 tions, produce*! milHons of times a second, occasion the luminous oscillations of the 

 ether which produce incandescence. The theory is very much open to discussion, 

 and I reproduce it here only to show that the idea of reactions that are set up and 

 discontinued millions of times a second, and consequently very different from all 

 those known, seems very acceptable to eminent chemists. 

 SM 1903 19 



