“Did he seem to you ‘made up’ in any way; disguised, I mean?”

“I couldn’t say.  The light was so very feeble.”

“You couldn’t see the colour of his eyes, for instance?”

“No.  I think they were grey, but I couldn’t be sure.”

“And as to the coachman.  He wore a wig, you said.  Could you see the colour of his eyes?  Or any peculiarity by which you could recognize him?”

“He had a malformed thumb-nail on his right hand.  That is all I can say about him.”

“He didn’t strike you as resembling Weiss in any way; in voice or features?”

“Not at all; and he spoke, as I told you, with a distinct Scotch accent.”

“The reason I ask is that if Weiss is attempting to poison this man, the coachman is almost certain to be a confederate and might be a relative.  You had better examine him closely if you get another chance.”

“I will.  And that brings me back to the question, What am I to do?  Ought I to report the case to the police?”

“I am inclined to think not.  You have hardly enough facts.  Of course, if Mr. Weiss has administered poison ‘unlawfully and maliciously’ he has committed a felony, and is liable under the Consolidation Acts of 1861 to ten years’ penal servitude.  But I do not see how you could swear an information.  You don’t know that he administered the poison—­if poison has really been administered—­and you cannot give any reliable name or any address whatever.  Then there is the question of sleeping sickness.  You reject it for medical purposes, but you could not swear, in a court of law, that this is not a case of sleeping sickness.”

“No,” I admitted, “I could not.”

“Then I think the police would decline to move in the matter, and you might find that you had raised a scandal in Dr. Stillbury’s practice to no purpose.”

“So you think I had better do nothing in the matter?”

“For the present.  It is, of course, a medical man’s duty to assist justice in any way that is possible.  But a doctor is not a detective; he should not go out of his way to assume police functions.  He should keep his eyes and ears open, and, though, in general, he should keep his own counsel, it is his duty to note very carefully anything that seems to him likely to bear on any important legal issues.  It is not his business officiously to initiate criminal inquiries, but it is emphatically his business to be ready, if called upon, to assist justice with information that his special knowledge and opportunities have rendered accessible to him.  You see the bearing of this?”

“You mean that I should note down what I have seen and heard and say nothing about it until I am asked.”

“Yes; if nothing further happens.  But if you should be sent for again, I think it is your duty to make further observations with a view, if necessary, to informing the police.  It may be, for instance, of vital importance to identify the house, and it is your duty to secure the means of doing so.”