Preoccupied as I was, by the condition of the patient, the professional habit of rapid and close observation caused me to direct a searching glance at the man before me.

It was only a brief glance--for Mr.Weiss, perhaps embarrassed by my keen regard of him, almost immediately withdrew into the shadow--and my attention seemed principally to be occupied by the odd contrast between the pallor of his face and the redness of his nose and by the peculiar stiff, bristly character of his eyebrows.

But there was another fact, and a very curious one, that was observed by me subconsciously and instantly forgotten, to be revived later when I reflected on the events of the night.

It was this: As Mr.Weiss stood, with his head slightly turned, I was able to look through one glass of his spectacles at the wall beyond.

On the wall was a framed print; and the edge of the frame, seen through the spectacle-glass, appeared quite unaltered and free from distortion, magnification or reduction, as if seen through plain window-glass; and yet the reflections of the candle-flame in the spectacles showed the flame upside down, proving conclusively that the glasses were concave on one surface at least.