llow. If the paper is smooth and well sized, all will disappear under a
sponge in a bath of hot water. There sometimes remains a yellowish trace.
To remove this, apply with a brush chlorated lime and then very weak
hydrochloric acid.

MUD. This may be removed simply with a wet sponge or in a warm water bath.
Where the paper is rough and absorbent, soap jelly should be used. If a
dark trace remains, it usually will yield to oxalic acid or cream of
tartar.

INK. Ordinary writing ink is easily decomposed because its principal
constituent is a vegetable matter, oakgall, mixed with a little iron
oxide. This gives way rather promptly to an application of sorrel salt
dissolved in boiling water. The water must be boiling to secure prompt
action. Even better success may be obtained by the use of pure oxalic
acid, which is an extraction from sorrel salt of which it is the base.[8]
Chinese ink cannot be dissolved but sometimes may be washed from a smooth
page by means of a damp sponge. Marking ink may be removed with chloride
of lime.

FRUIT JUICE. Stains from fruit may be removed by chlorine or cream of
tartar. In some cases, water alone is sufficient.

BLOOD. These stains may be bleached by chloride of lime. As this must be
applied for at least twenty minutes, it is better to use it as a damp
paste. There will remain a yellow trace which will give way to a weak
acid.

FECAL MATTERS OR URINE. For such spots, try soap and water. If this is
unsuccessful try successively chlorine, alkalis, oxalic acid and
hydrochloric acid, soaking the page for an hour in water between each
operation.

TRANSFERRED IMPRESSIONS. Frequently the characters of a book, bound before
the ink is completely dry, offset, while in press, an impression in
grayish tones upon the opposite pages or upon the faces of inserted
prints. These transferred impressions may sometimes be removed by rubbing
with an eraser made of bread crumbs or by soap-jelly, which should be
left on for some time and then washed off.

I have no doubt neglected to describe more than one kind of spot which an
amateur may find. By analogous reasoning, however, he may find for himself
the proper remedies to use. If the spot seems to be of a vegetable or
animal nature, he should use chlorine and sulfuric acid; if metallic,
diluted hydrochloric acid; if oily or greasy, essence of turpentine,
ether, alkaline solutions or benzine.

BLEACHING.[9] Soaking a print in cold water for about twe