THE ALUMNI JOURNAL. 17 



RADIO-ACTIVITY. 



By George E. Bolles, D. D. S., Pn.G. (N. Y. C. P.). 



At this stage of our progress in Chemical Science, we as profes- 

 sional units are called upon to give evidence of at least a general 

 knowledge of radioactivity. 



This is comparatively a new term, and having accorded to it only 

 a period of about nine years of existence. It was first recognised 

 by Prof. Bacquerel in the element Uranium in 1896 and although it 

 has been subjected to the most diligent and scrutinizing investiga- 

 tion b}^ men of science like Lodge, Crooks, Thompson and others, 

 still it is possible that we even exaggerate in saying that it is a 

 mere child. The facts which are concerned in explaining radio- 

 activity are somewhat arbitrary in their nature, and no doubt 

 many emphatic but instructive controversies will ensue before there 

 is established an absolute uniformity of opinion. Nevertheless, the 

 accepted facts at our command at this time are reasonably ample, 

 and in consideration of this condition T venture to give you a brief 

 outline of the accepted theory relative to the atomic condition of 

 some kinds of simple matter, such as Uranium, Thorium, Polonium, 

 Actinium, Radium and others, which possess this very remarkable 

 property of atomic radiation or radio-activity. 



Without taking any of your time by going into the history, man- 

 ner of obtaining, or physical properties of these several radioactive 

 elements, I will simply pass on to the real purport of this paper. 



Up to a few weeks ago, the atom was supposed to be the most 

 ultramicroscopic and indi^■isible ])ortion of matter. It was the all 

 important and fundamental unit of chemical science, and which has 

 subsequently permitted the building up of a chemical superstruction 

 which is to say the least actually choked with marvelous complexi- 

 ties. It has ever been an accepted fact, that the mass of an atom 

 of anything could not 1)e conceived of, it is so infinitesimal ; it is 

 utterly and absolutely beyond the possible concept of the human 

 mind to grasp its attenuated minuteness. This being the case, we 

 are at once consecutively filled with awe, incredulity, sense of ignor- 

 ance or intellectual incapacity, when we are gently but firmly in- 

 formed that atoms themselves are divisible, that they are not ulti- 

 mate quantities of matter, that they are made up of hundreds and 



