[Footnote I-44: History of Engraving, vol. i. p. 28.] [Footnote I-45: Three copies of this supposed unique book have long been known to bibliographers; one in the public library of Nuremberg, another in the Imperial library of Vienna, and the third in Lord Spenser’s library.] “It is possible,” says Zani, “that at this moment I may be blinded by partiality to my own nation; but I would almost assert, that _to deny the testimony of the French writer, would be like denying the existence of light on a fine sun-shiny day_.” His mental optics must have been of a peculiar character, and it can be no longer doubtful that he “Had lights where better eyes are blind, As pigs are said to see the wind.” Mr. Ottley’s own arguments in support of Papillon’s story are scarcely of a higher character than those which he has adopted from Zani. At page 40, in answer to an objection founded on the silence of all authorities, not merely respecting the particular work of the Cunio, but of the frequent practice of such an art, and the fact of no contemporary specimens being known, he writes as follows: “We cannot safely argue from the silence of contemporaneous authorities, that the art of engraving on wood was not practised in Europe in those early times; however, such silence may be an argument that it was not an art in high repute. Nor is our ignorance of such records a sufficient proof of their non-existence.” The proof of such a negative would be certainly difficult; but, according to this mode of argument, there is no modern invention which might not also be mentioned in “certain ancient undiscovered records.” In the general business of life, that rule of evidence is a good one which declares “_de non-apparentibus et non-existentibus eadem est ratio_;” and until it shall be a maxim in logic that “we ought readily to believe that to be true which we cannot prove to have been impossible,” Mr. Ottley’s solution of the difficulty does not seem likely to obtain general credence. At page 41, speaking of the probability of wood-engraving, for the purpose of taking impressions, being practised at an earlier period than has been generally supposed, Mr. Ottley expresses himself as follows: “Nor is it any proof or strong argument against the antiquity of such a practice, that authentic specimens of wood-engraving of those early times are not now to be found. They were, it may be supposed, for the most part, detached pieces, whose merits, as works of art, were not such as to render their preservation at all probable. They were the toys of the day; and, after having served the temporary purpose for which they were manufactured, were, no doubt, swept away to make room for others of newer fashion.” He thus requires those who entertain an opinion contrary to his own to prove a negative; while he assumes the point in dispute as most clearly established in his own favour.