John Van Eyck appears by sufficient evidence to have been born between 1390 and 1395; and, as the improved oil-painting was certainly introduced about 1410, the probability is greater that the system had been discovered by the elder brother than by the youth of 15. What the improvement actually was is a far more important question. Vasari's account, in the Life of Antonello da Messina, is the first piece of evidence here examined (p. 205); and it is examined at once with more respect and more advantage than the half-negligent, half-embarrassed wording of the passage might appear either to deserve or to promise. Vasari states that "_Giovanni_ of Bruges," having finished a tempera-picture on panel, and varnished it as usual, placed it in the sun to dry--that the heat opened the joinings--and that the artist, provoked at the destruction of his work-- * * * "began to devise means for preparing a kind of varnish which should dry in the shade, so as to avoid placing his pictures in the sun. Having made experiments with many things, both pure and mixed together, he at last found that linseed-oil and nut-oil, among the many which he had tested, were more drying than all the rest. These, therefore, boiled with _other mixtures of his_, made him the varnish which he, nay, which all the painters of the world, had long desired. Continuing his experiments with many other things, he saw that the immixture of the colors with these kinds of oils gave them a very firm consistence, which, when dry, was proof against wet; and, moreover, that the vehicle lit up the colors so powerfully, that it gave a gloss of itself without varnish; and that which appeared to him still more admirable was, that it allowed of blending [the colors] infinitely better than tempera. Giovanni, rejoicing in this invention, and being a person of discernment, began many works." * * *