three young women. I planned that each
person should be unconscious of the part he or she was playing, and that
each pair should be thrown constantly together--not in society, mind
you, for my theory was that conditions must be right. Through a trusted
and highly paid agent I hired my people--the men. Through another, who
was a woman, I hired those of the opposite sex. One of the young women
was sent to an obscure little place a hundred miles back from the
Brazilian coast, ostensibly to act as governess for the children of an
American family which did not exist. To this same place, through the
other agent, was sent a man, whose duty was to get information about the
country for a party of capitalists. Do you begin to understand?"

"Yes, I begin to understand," said Philip.

"This place to which they went was made up of a dozen or so hovels,"
continued the doctor, resuming his nervous walk. "There was no one
there who could talk or understand their language but these two. The
consequence--conditions were right. They would be constantly together.
They would either prove or disprove my theory that men and women were
but machines of passion. I knew that they would stay at this place
during the three months I had allotted for my experiment, for I paid
them a high price. The girl, when she found no American family, was told
to wait until they arrived. The man, of course, had plenty of supposed
work to keep him there."

"I understand," repeated Philip.

"The second couple," continued the doctor, forcing himself into a chair
opposite Philip, "were in a similar way sent up here--to an obscure
northern post which I have reason for not naming. And the third couple
went to a feverish district down in Central America."

He rose from his chair again, and Philip was silent while the doctor
went to his great-coat and from somewhere within its depths brought out
fresh cigarettes. His hand trembled slightly as he lighted one and the
flare of the match, playing for an instant on his face, emphasized the
nervous tension which he was under.

"I suppose you think it all very strange--and idiotic," he said, after
a few moments. "But we frequently do strange things, and apparently
senseless ones, in scientific work. Madmen have made the world's
greatness. Our most wonderful inventors, our greatest men of all ages,
have in a way been insane--for they have been abnormal, and what is that
but a certain form of insanity?"

He looked at Phi