"Diamonds," he began--and as he spoke his voice lost its faint flavour
of the tramp and assumed something of the easy tone of an educated
man--"are to be made by throwing carbon out of combination in a
suitable flux and under a suitable pressure; the carbon crystallises
out, not as black-lead or charcoal-powder, but as small diamonds. So
much has been known to chemists for years, but no one yet has hit upon
exactly the right flux in which to melt up the carbon, or exactly the
right pressure for the best results. Consequently the diamonds made by
chemists are small and dark, and worthless as jewels. Now I, you know,
have given up my life to this problem--given my life to it.

"I began to work at the conditions of diamond making when I was
seventeen, and now I am thirty-two. It seemed to me that it might take
all the thought and energies of a man for ten years, or twenty years,
but, even if it did, the game was still worth the candle. Suppose one
to have at last just hit the right trick, before the secret got out
and diamonds became as common as coal, one might realise millions.
Millions!"

He paused and looked for my sympathy. His eyes shone hungrily. "To
think," said he, "that I am on the verge of it all, and here!

"I had," he proceeded, "about a thousand pounds when I was twenty-one,
and this, I thought, eked out by a little teaching, would keep my
researches going. A year or two was spent in study, at Berlin chiefly,
and then I continued on my own account. The trouble was the secrecy.
You see, if once I had let out what I was doing, other men might have
been spurred on by my belief in the practicability of the idea; and I
do not pretend to be such a genius as to have been sure of coming in