wo great sciences of chemistry and
geology took their birth, or at least began to stand alone, at the close
of the last century, and have grown to be what we know them now within
about a hundred years, and that the study of living beings has within the
same time been so transformed as to be to-day something wholly different
from what it was in 1799. And, indeed, to say more would be to repeat
almost the same story about other things. If our present knowledge of
electricity is essentially the child of the nineteenth century, so also is
our present knowledge of many other branches of physics. And those most
ancient forms of exact knowledge, the knowledge of numbers and of the
heavens, whose beginning is lost in the remote past, have, with all other
kinds of natural knowledge, moved onward during the whole of the hundred
years with a speed which is ever increasing. I have said, I trust, enough
to justify the statement that in respect to natural knowledge a great gulf
lies between 1799 and 1899. That gulf, moreover, is a twofold one: not
only has natural knowledge been increased, but men have run to and fro,
spreading it as they go. Not only have the few driven far back round the
full circle of natural knowledge the dark clouds of the unknown, which
wrap us all about, but also the many walk in the zone of light thus
increasingly gained. If it be true that the few to-day are, in respect to
natural knowledge, far removed from the few of those days, it is also true
that nearly all which the few alone knew then, and much which they did not
know, has now become the common knowledge of the many.

What, however, I may venture to insist upon here is that the difference in
respect to natural knowledge, whatever be the case with other differences
between then and now, is undoubtedly a difference which means progress.
The span between the science of that time and the science of to-day is
beyond all question a great stride onward.

We may say this, but we must say it without boasting. For the very story
of the past, which tells of the triumphs of science, bids the man of
science put away from him all thoughts of vainglory, and that by many
tokens.

Whoever, working at any scientific problem, has occasion to study the
inquiries into the same problem by some fellow worker in the years long
gone by, comes away from that study humbled by one or other of two
different thoughts. On the one hand, he may find, when he has translated
the lang