Coal-Tar Substance for Preserving Wood
Puzzle 9 of Jane Austen Hard Pack
Question is: Coal-Tar Substance for Preserving Wood
and the answer is: CREOSOTE
Word Meaning:
CREOSOTE — A pale yellow oily liquid, containing phenols and similar compounds, obtained by the destructive distillation of wood tar, once used medicinally.
Definitions from Wiktionary.