PROGRESS IN PHYSICS—THOMSON. 205 
way that a specimen of the mineral thorianite must be more than 
240,000,000 years old. 
The physiological and medical properties of the rays emitted by 
radium is a field of research in which enough has already been done 
to justify the hope that it may lead to considerable alleviation of 
human suffering. It seems quite definitely established that for some 
diseases, notably rodent ulcer, treatment with these rays has pro- 
duced remarkable cures; it is imperative, lest we should be passing 
over a means of saving life and health, that the subject should be 
investigated in a much more systematic and extensive manner than 
there has yet been either time or material for. Radium is, however, 
so costly that few hospitals could afford to undertake pioneering work 
of this kind; fortunately, however, through the generosity of Sir 
Ernest Cassel and Lord Iveagh, a radium institute, under the pat- 
ronage of His Majesty the King, has been founded in London for the 
study of the medical properties of radium, and for the treatment of 
patients suffering from diseases for which radium is beneficial. 
The new discoveries made in physics in the last few years, and 
the ideas and potentialities suggested by them, have had an effect 
upon the workers in that subject akin to that produced in literature 
by the renaissance. Enthusiasm has been quickened, and there is a 
hopeful, youthful, perhaps exuberant, spirit abroad which leads men 
to make, with confidence, experiments which would have been thought 
fantastic iwenty years ago. It has quite dispelled the pessimistic 
feeling, not uncommon at that time, that all the interesting things 
had been discovered, and all that was left was to alter a decimal or 
two in some physical constant. There was never any justification for 
this feeling, there never were any signs of an approach to finality in 
science. The sum of knowledge is at present, at any rate, a diverging 
not a converging series. As we conquer peak after peak we see in 
front of us regions full of interest and beauty, but we do not see our 
goal, we do not see the horizon; in the distance tower still higher 
peaks, which will yield to those who ascend them still wider prospects, 
and deepen the feeling, whose truth is emphasized by every advance 
in science, that “* Great are the Works of the Lord.” 
