2 7 o POPULAR SCIENCE MONTHLY. 



And what are we to say of the supposed material emanation of radio- 

 active ' elements/ of their instability, of their decomposition by splitting 

 off of helium and of the decomposition of the elements themselves? 

 Until now there has not been furnished any demonstration whatever 

 that elements of high atomic weight, to which gold and platinum cer- 

 tainly must be counted, are polymers of elements of lower atomic 

 weights, and that they decompose into such. The idea of a chemical 

 element in the old sense remains still unshaken, and it will require 

 much more thorough chemical experimental research than those pro- 

 duced thus far, to disturb it. On the contrary, it appears from day 

 to day more plainly, that radioactivity seems to be extremely widely 

 distributed, and this observation leads us to the question whether radio- 

 activity may not be simply a purely physical phenomenon, which* may 

 be exhibited by matter without in any way modifying its chemical 

 nature, comparable to the magnetism of magnetic iron ore, which, like 

 radioactivity, may be intensified, transferred, apparently destroyed 

 and again called forth, and which, at the same time, also represents a 

 mysterious manifestation of energy, without leading any one for a 

 moment to imagine the existence of another element in magnetic ferrc- 

 ferric oxide not existing in the non-magnetic iron oxide. The idea 

 of an elemental material difference was not thought of by any one, 

 when Fr. Heusler succeeded in making magnetic alloys from unmag- 

 netic metals such as manganese, tin, antimony and aluminum. Also 

 in the case of radioactivity we should be free of material differences 

 if the statement of F. Eicharz and Eudolf Schenck should remain 

 without valid objection, namely, that oxygen when ozonized becomes 

 radioactive, so as to act upon the photographic plate, to make Sidot's 

 blende (though only this kind of sphalerite) glow intensely and, like 

 radium, to develop heat. 



Considering the radium-craze now afflicting the world and affecting 

 non-scientific circles especially, there is something humiliating to the 

 chemist, after six years have elapsed since the discovery of radium, 

 to say no more than that it resembles barium so closely that it can not 

 be distinguished except by its higher atomic weight and its remark- 

 able independent radiation. The chemical individuality of radium 

 remains almost entirely unknown; nevertheless it is constantly sought, 

 especially in those regions where pitchblende deposits occur, and where 

 they already dream of developing radium ores and a future radium 

 industry. So far as known, the occurrence of radioactive substances 

 is tied to that of uranium. This is in the highest degree surprising 

 and can not be understood if we are to assume the presence of special 

 elements. Though the co-occurrence of certain elements is not un- 

 common and may be explained by their position in the system, their 

 valence, the isomorphism of their compounds and other resemblances, 



