worth of which you cannot realize,
whatever guidance I can give you in the future for your physical and
spiritual life, is yours. I have done something for you, but not
much--I will do more. Only, in communicating with me, I ask you to
honour me with your full confidence in all matters pertaining to
yourself and your surroundings--then I shall not be liable to errors of
judgment in the opinions I form or the advice I give."

"I promise most readily," I replied gladly, for it seemed to me that I
was rich in possessing as a friend and counsellor such a man as this
student of the loftiest sciences.

"And now one thing more," he resumed, opening a drawer in the table
near which he sat. "Here is a pencil for you to write your letters to
me with. It will last about ten years, and at the expiration of that
time you can have another. Write with it on any paper, and the marks
will be like those of an ordinary drawing-pencil; but as fast as they
are written they disappear. Trouble not about this circumstance--write
all you have to say, and when you have finished your letter your
closely covered pages shall seem blank. Therefore, were the eye of a
stranger to look at them, nothing could be learned therefrom. But when
they reach me, I can make the writing appear and stand out on these
apparently unsullied pages as distinctly as though your words had been
printed. My letters to you will also, when you receive them, appear
blank; but you will only have to press them for about ten minutes in
this"--and he handed me what looked like an ordinary
blotting-book--"and they will be perfectly legible. Cellini has these
little writing implements; he uses them whenever the distances are too
great for us to amuse ourselves with the sagacity of Leo--in fact the
journeys of that faithful animal have principally been to keep him in
training."

"But," I said, as I took the pencil and book from his hand, "why do you
not make these convenient writing materials public property? They would
be so useful."

"Why should I build up a fortune for some needy stationer?" he asked,
with a half-smile. "Besides, they are not new things. They were known
to the ancients, and many secret letters, laws, histories, and poems
were written with instruments such as these. In an old library,
destroyed more than two centuries ago, there was a goodly pile of
apparently blank parchment. Had I lived then and known what I know now,
I could have made the white pages decl