MODERN CONCEPTIONS OF THE UNIVERSE. 69 
Though Sir John Herschel’s saying that atoms possess the 
essential character of manufactured articles is still correct, 
yet no manufactured article approaches in accuracy of 
execution the exactitude of atomic construction. We may 
conclude with Maxwell that “each molecule throughout the 
universe bears impressed upon it the stamp of a metric 
system as distinctly as does the Metre of the Archives at 
Paris,” 
This exactitude of atomic construction is not merely of 
academic interest, but is of real importance in the very 
practical work of maintaining definite standards of length. 
The metre of the Archives has been measured in terms of the 
wave-length corresponding to a particular line in the spectrum 
of cadmium, and it is to the constancy of this wave-length 
that we now trust rather than to the constancy of the length 
of the metal bar known as the metre of the Archives. 
In thinking about the creation of the universe, we shall 
perhaps be helped if we first consider what would be involved 
in the creation of a single new molecule at the present day. 
This event would not only require the creation of new matter 
but would also involve the establishment of relations between 
the new molecule and the countless millions already in existence, 
and this would change all those molecules to the extent of 
enabling each of them to act upon the new moiecule. If we 
speak in terms of the ether, we may say that such a connexion 
must be established between the new molecule and the ether 
that the molecule is able to cause disturbances in it which 
produce effects throughout the whole of space. 
The phenomena of tadio-activ ity have disclosed far more of the 
skill of the great Architect and Electrician than was even 
suspected a few years ago. For the formation of a molecule of 
uranium involves not only the construction of the minute 
electrified particles which it contains, but the assembling of them 
together and the supply of that vast store of energy which will 
enable the molecule at the right moment. perhaps a thousand 
million years after the formation of the molecule, to shoot out an 
electrified particle at a terrific speed. But this is not all, for 
the design of the uranium molecule is such that the modified 
molecule, which remains after the expulsion of the particle, will 
after a few days in its turn shoot out a particle and so on for 
several stages, the time of halting in each stage being some- 
times large, as with the 1,800 years of radium, and sometimes 
small, as with the four days of radium emanation. 
The Power which is capable of creating a single molecule is 
