octavo editions were exhausted in as many weeks; and Voltaire made a profit of at least ten thousand francs.  M. Foulet thinks that he left England shortly after this highly successful transaction, and that he established himself secretly in some town in Normandy, probably Rouen, where he devoted himself to the completion of the various works which he had in hand.  Be this as it may, he was certainly in France early in April 1729; a few days later he applied for permission to return to Paris; this was granted on the 9th of April, and the remarkable incident which had begun at the Opera more than three years before came to a close.

It was not until five years later that the Lettres Philosophiques appeared.  This epoch-making book was the lens by means of which Voltaire gathered together the scattered rays of his English impressions into a focus of brilliant and burning intensity.  It so happened that the nation into whose midst he had plunged, and whose characteristics he had scrutinised with so avid a curiosity, had just reached one of the culminating moments in its history.  The great achievement of the Revolution and the splendid triumphs of Marlborough had brought to England freedom, power, wealth, and that sense of high exhilaration which springs from victory and self-confidence.  Her destiny was in the hands of an aristocracy which was not only capable and enlightened, like most successful aristocracies, but which possessed the peculiar attribute of being deep-rooted in popular traditions and popular sympathies and of drawing its life-blood from the popular will.  The agitations of the reign of Anne were over; the stagnation of the reign of Walpole had not yet begun.  There was a great outburst of intellectual activity and aesthetic energy.  The amazing discoveries of Newton seemed to open out boundless possibilities of speculation; and in the meantime the great nobles were building palaces and reviving the magnificence of the Augustan Age, while men of letters filled the offices of State.  Never, perhaps, before or since, has England been so thoroughly English; never have the national qualities of solidity and sense, independence of judgment and idiosyncrasy of temperament, received a more forcible and complete expression.  It was the England of Walpole and Carteret, of Butler and Berkeley, of Swift and Pope.  The two works which, out of the whole range of English literature, contain in a supreme degree those elements of power, breadth, and common sense, which lie at the root of the national genius—­’Gulliver’s Travels’ and the ’Dunciad’—­both appeared during Voltaire’s visit.  Nor was it only in the high places of the nation’s consciousness that these signs were manifest; they were visible everywhere, to every stroller through the London streets—­in the Royal Exchange, where all the world came crowding to pour its gold into English purses, in the Meeting Houses of the Quakers, where the Holy Spirit rushed forth untrammelled to clothe itself in the sober garb of English idiom, and in the taverns of Cheapside, where the brawny fellow-countrymen of Newton and Shakespeare sat, in an impenetrable silence, over their English beef and English beer.