For some years after the new library was established Naude travelled in quest of books over the greater part of Europe. He said that he would have ransacked Spain if Mazarin had not preferred an invasion by the regular army. He was the 'familiar spirit' of the auction-room, and it became a by-word that a visit from the great book-hunter was as bad as a storm in the book-shops. He boasted in his epigrams of exploits in Flanders, in Switzerland, and among the Venetian book-stalls. At Rome he bought books by the fathom; he skimmed the German shelves, and passed over into England to relieve the islanders of their riches. At Lyons he met Marshal Villeroi, who gave him a great portion of the books which Cardinal de Tournon had bequeathed to the Jesuits. We trace the result of his travels in his description of the libraries of Europe. Certain subjects, as he said, are in vogue at particular places, and we ought always to notice the book-fashions to show our respect for the feelings of mankind. 'For positive science we go to Rome or Florence or Naples, and for jurisprudence to Paris or Milan; France supplies us with history; and if we wanted scholastic lore we might go to Spain, or the colleges of Oxford and Cambridge.' In 1647 the Mazarine Library contained about 45,000 volumes, and Naude in his joy proclaimed it as the eighth wonder of the world. The Parisians appeared to be delighted with the superb Lomenie MSS. and the crowd of bright volumes in the Cardinal's ordinary livery. But in 1651 the Parliament got the upper hand of the 'Red Tyrant' in one of the unmeaning struggles of the Wars of the Fronde; the property of Mazarin was confiscated for a time, and the library was put up for sale. The list of Commissioners included the respectable names of Alexandre Petau and Pierre Pithou; yet we are assured that the auction resembled a massacre, and that hardly any obstacle was placed in the way of the most impudent thefts. Naude in vain petitioned against a decree which had fallen like a thunder-bolt on the 'wonderful work of his life.' 'Why will you not save this daughter of mine, this library that is the fairest and best-endowed in the world? Can you permit the public to be deprived of such a precious and useful treasure? Can you endure that this fair flower, which spreads its perfume through the world, should wither as you hold it in your hands?'