From Newnes Household Encyclopaedia (London, 1931.)
Books. To preserve from insects.
If books are occasionally dusted over with a mixture of white pepper and powdered alum they will be insured against the attacks of insects.
A more modern recipe, taken from anecdotal evidence, is one to rid a book of unpleasant odours (especially tobacco smoke). Place the book in a container of wood chip based cat litter so that is submerged and leave it there for 48 hours. The idea is that the chips will extract objectionable smells. Books reeking of tobacco have become hard to sell...