text: " Lanzi here well observes that the expression "long desired " shows that there must have been many attempts to make oils properly subservient to the painter's use and that there was none successful until Van Eyck's "solo quella perfetta;" which as Vasari says "secca non teme acqua che accende i colori e gli fa lucidi e gli unisce mirabilmente"--"which when dry does not fear water heightens the colours and makes them lucid and unites them in a wonderful manner