body of specialists, who require a new medium for their researches
and communications. The time has already come when we cannot
assume that any specialist is acquainted with all that is being
done even in his own line. To keep the run of this may well be
beyond his own powers; more he can rarely attempt.

What is the science of the future to do when this huge mass
outgrows the space that can be found for it in the libraries, and
what are we to say of the value of it all? Are all these
scientific researches to be classed as really valuable
contributions to knowledge, or have we only a pile in which
nuggets of gold are here and there to be sought for? One
encouraging answer to such a question is that, taking the
interests of the world as a whole, scientific investigation has
paid for itself in benefits to humanity a thousand times over, and
that all that is known to-day is but an insignificant fraction of
what Nature has to show us. Apart from this, another feature of
the science of our time demands attention. While we cannot hope
that the multiplication of specialties will cease, we find that
upon the process of differentiation and subdivision is now being
superposed a form of evolution, tending towards the general unity
of all the sciences, of which some examples may be pointed out.

Biological science, which a generation ago was supposed to be at
the antipodes of exact science, is becoming more and more exact,
and is cultivated by methods which are developed and taught by
mathematicians. Psychophysics--the study of the operations of the
mind by physical apparatus of the same general nature as that used
by the chemist and physicist--is now an established branch of
research. A natural science which, if any comparisons are