is not fitted or suited for a paint extender. A few decades since, the very brilliant business manager of a large paint factory, led on by the no less brilliant chief of the laboratory of a large corporation, both of the gentlemen referred to having since passed away, conceived the idea that anhydrous calcium sulphate (calcined plaster) first being mixed and ground on dry color mills to impalpable fineness with a certain percentage of nearly chemically pure red oxide of iron in place of using the hydrated calcium sulphate (gypsum) and then mixing and grinding the product in oil in the usual way would produce a Venetian red of greater brilliancy and body. Tests were made accordingly and carried on for about a month or so, when the manager was satisfied that he had made a great discovery. Orders were issued to substitute the plaster for gypsum in all Venetian reds so manufactured and inside of three months some 80 tons or more had been distributed to jobbers, dealers and consumers. All was going well until the spring season arrived, when some painters who had used the red color on brick fronts reported that after a driving rainstorm beating on the fresh paint it spotted white on drying. Several others who had used water on top of their pails containing the red to keep the paint from skimming over reported that the color had set hard in the pail for several inches from the top. After a thorough investigation the complaints were found justifiable and the reds were withdrawn from the market and remodeled by rehydrating the calcined plaster contained therein which, although at no small cost, succeeded very well, as was proven by repeated trials. The parties in question had not taken into calculation that linseed oil takes up water and that, in consequence, the water, coming in contact with the paint after being spread, would cause the setting of the plaster.