Tradition has for centuries connected the name of Van Eyck with the invention of oil-painting, and has fixed upon the year 1410 as the date of this invention. This, at least, is the year given by such early writers as Guicciardini, Vasari, Opmeer, and Karel van Mander. Vasari, indeed, gives a most detailed and circumstantial account of this epoch-making event, which, according to the Aretine biographer, was brought about by the single-handed efforts of Jan. And it is easy to understand that the fame of the elder brother had in the sixteenth century become obscured and merged in that of the brilliantly successful Jan, the _varlet de chambre_ and official Court painter. This "Giovanni of Bruggia," Vasari tells us, "after having given extreme labour to the completion of a certain picture, and with great diligence brought it to a successful issue, he gave it the varnish and set it to dry in the sun, as is the custom. But whether because {21} the heat was too violent, or that the wood was badly joined or insufficiently seasoned, the picture gave way at the joinings, opening in a very deplorable manner. Thereupon Giovanni, perceiving the mischief done to his work by the heat of the sun, determined to proceed in such a manner that the same thing should never again injure his work in like manner. And as he was no less embarrassed by his varnishes than by the process of tempera-painting, he turned his thoughts to the discovery of some sort of varnish that would dry in the shadow, to the end that he need not expose his pictures to the sun. Accordingly, after having made many experiments on substances, pure and mixed, he finally discovered that linseed oil and oil of nuts dried more readily than any others of all that he had tried. Having boiled these oils, therefore, with other mixtures, he thus obtained the varnish which he--or, rather, all the painters of the world--had so long desired. He made experiments with many other substances, but finally decided that mixing the colours with these oils gave a degree of firmness to the work which not only secured it against all injury from water when once dried, but also imparted so {22} much life to the colours that they exhibited a sufficient lustre in themselves without the aid of varnish; and what appeared to him more extraordinary than all besides was that the colours thus treated were much more easily united and blent than when in tempera."