Enquire within upon everything by Robert Kemp Philp

436. Stains and Marks from Books.

A solution of oxalic acid, citric acid, or tartaric acid, is attended with the least risk, and may be applied to paper and prints without fear of damage. These acids, which take out writing ink, and do not touch the printing, can be used for restoring books where the margins have been written upon, without injuring the text.