?"

"Very seldom indeed. I spend as much time with him as I can, and when I
am not able to be in the room, Mrs Schallibaum, my housekeeper, sits
with him."

"Is he often as drowsy as he is now?"

"Oh, very often; in fact, I should say that is his usual condition. He
rouses up now and again, and then he is quite lucid and natural for,
perhaps, an hour or so; but presently he becomes drowsy again and doses
off, and remains asleep, or half asleep, for hours on end. Do you know
of any disease that takes people in that way?"

"No," I answered. "The symptoms are not exactly like those of any
disease that is known to me. But they are much very like those of opium
poisoning."

"But, my dear sir," Mr. Weiss retorted impatiently, "since it is clearly
impossible that it can be opium poisoning, it must be something else.
Now, what else can it be? You were speaking of congestion of the brain."

"Yes. But the objection to that is the very complete recovery that seems
to take place in the intervals."

"I would not say very complete," said Mr. Weiss. "The recovery is rather
comparative. He is lucid and fairly natural in his manner, but he is
still dull and lethargic. He does not, for instance, show any desire to
go out, or even to leave his room."

I pondered uncomfortably on these rather contradictory statements.
Clearly Mr. Weiss did not mean to entertain the theory of opium
poisoning; which was natural enough if he had no knowledge of the drug
having been used. But still--

"I suppose," said Mr. Weiss, "you have experience of sleeping sickness?"

The suggestion startled me. I had not. Very few people had. At that time
practically nothing was known about the disease. It was a mere
pathological curiosity, almost unheard of excepting by a few
practitioners in remote parts of Africa, and hardly referred to in the
text-books. Its connection with the trypanosome-bearing insects was as
yet unsuspected, and, to me, its symptoms were absolutely unknown.

"No, I have not," I replied. "The disease is nothing more than a name to
me. But why do you ask? Has Mr. Graves been abroad?"

"Yes. He has been travelling for the last three or four years, and I
know that he spent some time recently in West Africa, where this disease
occurs. In fact, it was from him that I first heard about it."

This was a new fact. It shook my confidence in my diagnosis very
considerably, and inclined me to reconsider my suspicions. If Mr. Weiss
was lying