Meanwhile the life of the Court—­which passed for the most part at Potsdam, in the little palace of Sans Souci which Frederick had built for himself—­proceeded on its accustomed course.  It was a singular life, half military, half monastic, rigid, retired, from which all the ordinary pleasures of society were strictly excluded.  ’What do you do here?’ one of the royal princes was once asked.  ’We conjugate the verb s’ennuyer,’ was the reply.  But, wherever he might be, that was a verb unknown to Voltaire.  Shut up all day in the strange little room, still preserved for the eyes of the curious, with its windows opening on the formal garden, and its yellow walls thickly embossed with the brightly coloured shapes of fruits, flowers, birds, and apes, the indefatigable old man worked away at his histories, his tragedies, his Pucelle, and his enormous correspondence.  He was, of course, ill—­very ill; he was probably, in fact, upon the brink of death; but he had grown accustomed to that situation; and the worse he grew the more furiously he worked.  He was a victim, he declared, of erysipelas, dysentery, and scurvy; he was constantly attacked by fever, and all his teeth had fallen out.  But he continued to work.  On one occasion a friend visited him, and found him in bed.  ‘J’ai quatre maladies mortelles,’ he wailed.  ‘Pourtant,’ remarked the friend, ‘vous avez l’oeil fort bon.’  Voltaire leapt up from the pillows:  ‘Ne savez-vous pas,’ he shouted, ’que les scorbutiques meurent l’oeil enflamme?’ When the evening came it was time to dress, and, in all the pomp of flowing wig and diamond order, to proceed to the little music-room, where his Majesty, after the business of the day, was preparing to relax himself upon the flute.  The orchestra was gathered together; the audience was seated; the concerto began.  And then the sounds of beauty flowed and trembled, and seemed, for a little space, to triumph over the pains of living and the hard hearts of men; and the royal master poured out his skill in some long and elaborate cadenza, and the adagio came, the marvellous adagio, and the conqueror of Rossbach drew tears from the author of Candide.  But a moment later it was supper-time; and the night ended in the oval dining-room, amid laughter and champagne, the ejaculations of La Mettrie, the epigrams of Maupertuis, the sarcasms of Frederick, and the devastating coruscations of Voltaire.

Yet, in spite of all the jests and roses, everyone could hear the rumbling of the volcano under the ground.  Everyone could hear, but nobody would listen; the little flames leapt up through the surface, but still the gay life went on; and then the irruption came.  Voltaire’s enemy had written a book.  In the intervals of his more serious labours, the President had put together a series of ‘Letters,’ in which a number of miscellaneous scientific subjects were treated in a mildly speculative and popular style.  The volume was rather dull, and very unimportant;