even the history of our opinions."[Footnote: D'Alembert,
_Oeuvres_, i. 79 (_Eloge par Condorcet_).] So comprehensive a
scheme was not without danger to those classes which claimed an
exclusive right to direct men's minds. As for the double nature of the
book, we have the words of two of the men most concerned in its
preparation. First there is an anecdote by Voltaire, certainly
inaccurate, probably quite imaginary, but setting forth most clearly one
cause of the interest which the "Encyclopaedia" excited.

"A servant of Louis XV. has told me that one day when the king his
master was supping at Trianon with a small party, the conversation
turned on shooting and then on gunpowder. Somebody said that the best
powder was made of equal parts of saltpetre, sulphur, and charcoal. The
Duke of La Valliere, better informed, maintained that for cannon the
proper proportion was one part of sulphur, one of charcoal, and five of
well-filtered, well-evaporated, and well-crystallized saltpetre.

"`It is absurd,' said the Duke of Nivernois, `that we should amuse
ourselves every day with killing partridges in the park of Versailles,
and sometimes with killing men or getting ourselves killed on the
frontier, and not know exactly what we kill with.'

"`Alas! we are in the same state about all things in the world,'
answered Madame de Pompadour. `I don't know of what the rouge is
composed that I put on my cheeks, and I should be much puzzled to say
how my stockings are made.'

"`It is a pity,' then said the Duke of La Valliere, `that His Majesty
should have confiscated our encyclopaedic dictionaries, which cost us a
hundred pistoles apiece. We should soon find in them the answers to all