emorselessly to abandon all in
which these are not agreed. His reward is that he gets, however little
is certain, forming a strong foundation for what is yet to come. Even by
this path of self-restraint and verification, however, he is making for
a region surpassing wonder. In the range of that invisible light, gross
objects cease to be a barrier, and force and matter become less
aesthetic. When the veil is suddenly lifted, upon the vision hitherto
unsuspected, he may for a moment lose his accustomed self-restraint and,
exclaim "not 'as if'--but the thing itself!"

INVISIBLE LIGHT.

In illustration of this sense of wonder which links together poetry and
science, let me allude briefly to a few matters that belong to my own
small corner in the great universe of knowledge, that of light invisible
and of life unvoiced. Can anything appeal more to the imagination than
the fact that we can detect the peculiarities in the internal molecular
structure of an opaque body by means of light that is itself invisible?
Could anything have been more unexpected than to find that a sphere of
China-clay focuses invisible light more perfectly than a sphere of glass
focuses the visible; that in fact, the refractive power of this clay to
electric radiation is at least as great as that of the most costly
diamond to light? From amongst the innumerable octaves of light, there
is only one octave, with power to excite the human eye. In reality, we
stand, in the midst of a luminous ocean, almost blind! The little that
we can see is nothing, compared to the vastness of that which we cannot.
But it may be said that out of the very imperfection of his senses man
has been able, in science, to build for himself a raft of thought by
which to make daring adventure on the great seas of the unknown.

UNVOICED LIFE.

Again, just as, in following up light from visible to invisible, our
range of investigation transcends our physical sight, so also does our
power of sympathy become extended, when we pass from the voiced to the
unvoiced, in the study of life: Is there then any possible relation
between our own life and that of the plant world? That there may be such
a relation, some of the foremost of scientific men have denied. So
distinguished a leader as the late Burdon-Sanderson declared that the
majority of plants were not capable of giving any answer, by either
mechanical or electrical excitement, to an outside stock. Pfeffer,
again, and his disti