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.