ain
given publicity in full in his celebrated volume on natural philosophy,
consisting in part of his lectures before the Royal Institution,
published in 1807; but even then they failed to bring conviction to
the philosophic world. Indeed, they did not even arouse a controversial
spirit, as his first papers had done.

ARAGO AND FRESNEL CHAMPION THE WAVE THEORY

So it chanced that when, in 1815, a young French military engineer,
named Augustin Jean Fresnel, returning from the Napoleonic wars,
became interested in the phenomena of light, and made some experiments
concerning diffraction which seemed to him to controvert the accepted
notions of the materiality of light, he was quite unaware that his
experiments had been anticipated by a philosopher across the Channel.
He communicated his experiments and results to the French Institute,
supposing them to be absolutely novel. That body referred them to a
committee, of which, as good fortune would have it, the dominating
member was Dominique Francois Arago, a man as versatile as Young
himself, and hardly less profound, if perhaps not quite so original.
Arago at once recognized the merit of Fresnel's work, and soon became a
convert to the theory. He told Fresnel that Young had anticipated him
as regards the general theory, but that much remained to be done, and
he offered to associate himself with Fresnel in prosecuting the
investigation. Fresnel was not a little dashed to learn that his
original ideas had been worked out by another while he was a lad, but he
bowed gracefully to the situation and went ahead with unabated zeal.

The championship of Arago insured the undulatory theory a hearing
before the French Institute, but by no means sufficed to bring about
its general acceptance. On the contrary, a bitter feud ensued, in which
Arago was opposed by the "Jupiter Olympus of the Academy," Laplace, by
the only less famous Poisson, and by the younger but hardly less able
Biot. So bitterly raged the feud that a life-long friendship between
Arago and Biot was ruptured forever. The opposition managed to delay the
publication of Fresnel's papers, but Arago continued to fight with his
customary enthusiasm and pertinacity, and at last, in 1823, the Academy
yielded, and voted Fresnel into its ranks, thus implicitly admitting the
value of his work.

It is a humiliating thought that such controversies as this must mar
the progress of scientific truth; but fortunately the story of th