ent powder ("French Chalk" answers very well) will
operate better if the powdered sheet is enclosed simply between two
pieces of paper, and a hot flat-iron applied. Plenty of powder should be
used. M. S. B.

[8] Before and after using oxalic acid on ink stains, it is best to wash
the spot or page with hydrochloric acid mixed with about seven times its
volume of water. In bleaching ink from a page, a white mark almost always
remains, especially noticeable if the paper is tinted with age. It is far
better to soak the whole page, to secure uniform bleaching, and then, if
necessary, retint the page to its former color, than to attempt to operate
on part of a page only. Sometimes, when a book is loosely bound, the page
can be carefully cut out, close to the sewing, and pasted in again when it
has been washed and dried as desired. This is, however, a questionable
practice, and may seriously injure the value of the book, and on a
valuable book it is better to cut the sewing and remove the entire
signature, then have the book rebound, or resewn and returned to the old
covers, as may be most advisable. M. S. B.

[9] Bonnardot mentions several processes for bleaching a print, equally
applicable to the same operation on the pages of a book. I translate the
process which seems to be the simplest and most effective. It will be
noted that he does not mention the size of the bottle in which the amount
of chemical he advises is to be dissolved. I would suggest a full quart
bottle, and also that the amateur operator thoroughly try the effect of
his solution on some old pieces of paper to make sure it is too weak to
injure the body of the paper. M. S. B.

[10] Bonnardot, at this point, discusses in considerable detail various
opinions as to the removal of these iron oxide stains, but without coming
to any definite conclusion except that they are "of all stains, the most
tenacious." Experiments in chemistry, especially upon any binding of
value, should not be lightly undertaken. The use of water-colors for
retinting the spot of yellowish bleach might be tried with more safety and
a greater possibility of success. M. S. B.

[11] Certain bindings of the sixteenth century have on their covers
designs in tint formed simply of water colors. In such cases, the flour
paste should not be used, or else the designs should first be accurately
traced so that they can be restored, if necessary, after the operation.

[12] Centigrade, i.