Formerly, the first priming was made with dark red, mixed with umber, or with pure umber; and some sixty years since, it was supposed that the drying of this colour would be quickened by mixing it with litharge; but it has been discovered that pictures painted on these sorts of preparations, in a few years have their surfaces covered with a multitude of little grains like sand; and thus proving that the litharge was badly prepared.1,At the present day, the artists are more careful in such essential matters; and the colourmen, for their own sakes, are excited to prepare their canvasses with more attention, for any negligence in these essential matters would ruin their trade., ,1 Had the litharge been very finely ground, that evil effect could not have occurred.,,,