"

"It may have been wilful murder, or he may have taken it voluntarily,"
I answered. "But it is most evident that the symptoms are those of
poisoning."

Ambler gave vent to a low grunt, half of satisfaction, half of
suspicion. I knew that grunt well. When on the verge of any discovery
he always emitted that guttural sound.

"We'd better inform the police," I remarked. "That's all we can do.
The poor fellow is dead."

"Dead! Yes, we know that. But we must find out who killed him."

"Well," I said, "I think at present, Ambler, we've quite sufficient on
our hands without attempting to solve any further problems. The poor
man may have been in despair and have taken poison wilfully."

"In despair!" echoed the old man. "No fear. Lanky was happy enough. 'E
wasn't the sort of fellow to hurry hisself out o' the world. He liked
life too jolly well. Besides, he 'ad a tidy bit o' money in the
Savin's Bank. 'E was well orf once, wer' Lanky. Excuse me for
interruptin'."

"Well, if he didn't commit suicide," I remarked, "then, according to
all appearances, poison was administered to him wilfully."

"That appears to be the most feasible theory," Ambler said. "Here we
have still a further mystery."

Of course, the post-mortem appearances of poisoning, except in a few
instances, are not very characteristic. As every medical man is aware,
poison, if administered with a criminal intent, is generally in such a
dose as to take immediate effect--although this is by no means
necessary, as there are numerous substances which accumulate in the
system, and when given in small and repeated quantities ultimately
prove fatal--notably, antimony. The diagnosis of the effects of
irritant poisons is not so difficult as it is in the case of narcotics
or other neurotics, where the symptoms are very similar to those
produced by apoplexy, epilepsy, tetanus, convulsions, or other forms
of disease of the brain. Besides, one of the most difficult facts we
have to contend with in such cases is that poison may be found in the
body, and yet a question may arise as to its having been the cause of
death.

CHAPTER XXVIII.

"POOR MRS. COURTENAY."

Ambler appeared to be much concerned regarding the poor man's death.
When we had first met beside his vegetable barrow in the London Road
he certainly seemed a hard-working, respectable fellow, with a voice
rendered hoarse and rough by constantly shouting his wares. But by the
whispered words that