m_ of the parchment. Although
one of its corners had been, by some accident, destroyed, it could be
seen that the original form was oblong. It was just such a slip,
indeed, as might have been chosen for a memorandum--for a record of
something to be long remembered and carefully preserved."

"But," I interposed, "you say that the skill was not upon the parchment
when you made the drawing of the beetle. How then do you trace any
connection between the boat and the skull---since this latter,
according to your own admission, must have been designed (God only
knows how or by whom) at some period subsequent to your sketching the
_scarabaeus_?"

"Ah, hereupon turns the whole mystery; although the secret, at this
point, I had comparatively little difficulty in solving. My steps were
sure, and could afford but a single result I reasoned, for example,
thus: When I drew the _scarabaeus_, there was no skull apparent upon
the parchment When I had completed the drawing I gave it to you, and
observed you narrowly until you returned it. You, therefore, did not
design the skull, and no one else was present to do it. Then it was
not done by human agency. And nevertheless it was done.

"At this stage of my reflections I endeavored to remember, and _did_
remember, with entire distinctness, every incident which occurred about
the period in question. The weather was chilly (oh, rare and happy
accident!), and a fire was blazing upon the hearth. I was heated with
exercise and sat near the table. You, however, had drawn a chair close
to the chimney. Just as I placed the parchment in your hand, and as
you were in the act of inspecting it, Wolf, the Newfoundland, entered,
and leaped upon your shoulders. With your left hand you caressed him
and kept him off, while your right, holding the parchment, was
permitted to fall listlessly between your knees, and in close proximity
to the fire. At one moment I thought the blaze had caught it, and was
about to caution you, but, before I could speak, you had withdrawn it,
and were engaged in its examination. When I considered all these
particulars, I doubted not for a moment that heat had been the agent in
bringing to light, upon the parchment, the skull which I saw designed
upon it. You are well aware that chemical preparations exist, and have
existed time out of mind, by means of which it is possible to write
upon either paper or vellum, so that the characters shall become
visible only wh