in the education of the lad.
He seems to have entered every available field of thought--mathematics,
physics, botany, literature, music, painting, languages, philosophy,
archaeology, and so on to tiresome lengths--and once he had entered any
field he seldom turned aside until he had reached the confines of the
subject as then known and added something new from the recesses of his
own genius. He was as versatile as Priestley, as profound as Newton
himself. He had the range of a mere dilettante, but everywhere the full
grasp of the master. He took early for his motto the saying that what
one man has done, another man may do. Granting that the other man has
the brain of a Thomas Young, it is a true motto.

Such, then, was the young Quaker who came to London to follow out
the humdrum life of a practitioner of medicine in the year 1801. But
incidentally the young physician was prevailed upon to occupy the
interims of early practice by fulfilling the duties of the chair of
Natural Philosophy at the Royal Institution, which Count Rumford
had founded, and of which Davy was then Professor of Chemistry--the
institution whose glories have been perpetuated by such names as Faraday
and Tyndall, and which the Briton of to-day speaks of as the "Pantheon
of Science." Here it was that Thomas Young made those studies which have
insured him a niche in the temple of fame not far removed from that of
Isaac Newton.

As early as 1793, when he was only twenty, Young had begun to
Communicate papers to the Royal Society of London, which were adjudged
worthy to be printed in full in the Philosophical Transactions; so it
is not strange that he should have been asked to deliver the Bakerian
lecture before that learned body the very first year after he came to
London. The lecture was delivered November 12, 1801. Its subject was
"The Theory of Light and Colors," and its reading marks an epoch in
physical science; for here was brought forward for the first time
convincing proof of that undulatory theory of light with which every
student of modern physics is familiar--the theory which holds that light
is not a corporeal entity, but a mere pulsation in the substance of
an all-pervading ether, just as sound is a pulsation in the air, or in
liquids or solids.

Young had, indeed, advocated this theory at an earlier date, but it was
not until 1801 that he hit upon the idea which enabled him to bring it
to anything approaching a demonstration. It was whil