This week's competition, in which you have to identify a book from its opening sentence, is from a work famous for its queries:
"My design in this book is not to explain the properties of light by hypotheses, but to propose and prove them by reason and experiments."
* Entries, including postal address, should be sent to First Impressions, The Times Higher , Admiral House, 66-68 East Smithfield, London E1W 1BX, faxed to 020 7782 3300 or e-mailed to firstname.lastname@example.org
The winner receives a £25 book voucher. The closing date is September 26.
The winner of last week's competition, who identified Rudyard Kipling's Puck of Pook's Hill, is Manfredi La Manna, reader in economics, University of St Andrews.
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