In the figurative sense the phrase “to burn the candle at both ends” originally referred to the wasting of one’s material wealth, as when a husband and wife were both spendthrifts.
We still use it with that sense, but our usual application is to the wasteful consumption of one’s physical powers, as when a person tries to work all day and write a book in his evenings and spare time.
It is not a new saying, and was not originally English, for Cotgrave, who died in 1611, records it in his French-English dictionary, “Brusler la chandelle par lex deux bouts.”
