It was the print of the thumb of the forty-third man of Company C whom I had experimented on--Private Franz Adler.

An hour before, I did not know the murderer's name, or voice, or figure, or face, or nationality; but now I knew all these things! I believed I might feel sure; the Frenchman's repeated demonstrations being so good a warranty.

Still, there was a way to MAKE sure.

I had an impression of Kruger's left thumb.

In the morning I took him aside when he was off duty; and when we were out of sight and hearing of witnesses, I said, impressively-- 'A part of your fortune is so grave, that I thought it would be better for you if I did not tell it in public.