The astonishment, the envy almost, of Petrarch is a proof, if not of the truth of this incredible fact, at least of his own veracity. The abbé de Sade (Memoires, tom. iii. p. 242) quotes the 6th epistle of the 13th book of Petrarch, but it is of the royal MS., which he consulted, and not of the ordinary Basil edition (p. 920).