d a deep brown. Stand the dish on end (the
leaf of course sticks to the bottom of the dish) to drain while you
prepare the bleaching part of the operation. Now take a similar jug, put
half an ounce of oxalic acid into it, and again fill up with hot water.
Pour this (hot but not boiling) over the leaf as before. When the leaf is
as white as the dish itself, which will take from five minutes to a
quarter of an hour, pour off the solution and wash the surplus fluid
away. Then let the leaf wash in gently running water for one hour. Our
book-hunter always uses the bath for this purpose, but a tin foot-bath
under a tap does excellently. The best way to dry the leaf is to press it
gently between two sheets of unused blotting-paper, then remove the upper
sheet and allow the leaf to dry naturally. Remember, however, that after
any washing or bleaching, leaves must always be 'sized' to give back to
the paper that substance which the washing has taken out. You will find
full instructions for doing this in the text-books I have mentioned. It
is quite a simple matter.

Mr. Cockerell recommends that the permanganate bath be only 'warmed
slightly,' and that the leaf be left in it for 'about an hour.' Our
book-hunter has found (fortunately not to his cost, for the volumes
which he used for experimental purposes were valueless) that this
sometimes rots the paper, and on one occasion the leaves at the end of an
hour came to pieces when the solution was poured off. If used hot and
quickly it does not seem to injure the paper, but the water must never be
so hot that you cannot bear your finger in it, and you must take care
never to use a _stronger_ solution. A strong solution of permanganate
will reduce paper to pulp in a few minutes. For similar reasons our
bookman prefers oxalic to sulphurous acid, but this too must never be
used stronger than I have indicated. I hasten to add, however, in
deference to such an excellent authority, that our book-hunter does not
_recommend_, but merely states the methods with which he personally has
been successful.

The most difficult stains to remove that the writer has yet come across
are those made by a child's paint-box. Some colours are easily removed,
but seventeenth-century gamboge is a perfect beast. The only successful
way to deal with these 'stains' is by studying the chemistry of the
'colours,' and the re-actions of the chemicals of which they are made.
With a little experimenting there is no