chemists,' were staying in a villa near Santo Domenico, between Fiesole
and Florence. He was then only fifteen, but he was already distinguished
as a mathematician and possessed by a savage appetite to understand. He
had been particularly attracted by the mystery of phosphorescence and
its apparent unrelatedness to every other source of light. He was
to tell afterwards in his reminiscences how he watched the fireflies
drifting and glowing among the dark trees in the garden of the villa
under the warm blue night sky of Italy; how he caught and kept them in
cages, dissected them, first studying the general anatomy of insects
very elaborately, and how he began to experiment with the effect of
various gases and varying temperature upon their light. Then the chance
present of a little scientific toy invented by Sir William Crookes, a
toy called the spinthariscope, on which radium particles impinge upon
sulphide of zinc and make it luminous, induced him to associate the two
sets of phenomena. It was a happy association for his inquiries. It was
a rare and fortunate thing, too, that any one with the mathematical gift
should have been taken by these curiosities.

Section 8

And while the boy Holsten was mooning over his fireflies at Fiesole,
a certain professor of physics named Rufus was giving a course of
afternoon lectures upon Radium and Radio-Activity in Edinburgh.
They were lectures that had attracted a very considerable amount of
attention. He gave them in a small lecture-theatre that had become more
and more congested as his course proceeded. At his concluding discussion
it was crowded right up to the ceiling at the back, and there people
were standing, standing without any sense of fatigue, so fascinating
did they find his suggestions. One youngster in particular, a
chuckle-headed, scrub-haired lad from the Highlands, sat hugging his