Here Mr. Ware undoubtedly errs in attributing the success of Allston's flesh tints to the use of solid color alone. Such effects are not possible without the aid of transparent colors in glazing; but it is the judicious combination of solid with transparent pigments, combined not bodily on the palette, but in their use on the canvas, that gives to oil-painting all its unrivalled power in the hands of a master. Allston was accustomed to inlay his pictures in solid crude color with a medium that hardened like stone, and to leave them months and even years to dry before finishing them with the glazing colors, which worked in his hands like magic over such a well-hardened surface. By this method of working he was able to secure solidity of appearance, richness of color, unity of effect, and atmospheric repose and tenderness enveloping all objects in the picture. Many of his unfinished works are left in the first stage of this process, showing precisely how far he relied on the use of solid color; and by comparing the works left in this state with his finished pictures, one may see how much he was indebted to the use of transparent glazes for the beauty, tenderness, and variety of color in the last stages of his work.
In 1839 there was an exhibition in Boston of such of the works of Allston as could be borrowed for the occasion. This was managed by the friends of the artist for his benefit. The exhibition was held in Harding's Gallery, a square, well-lighted room, but too small for the larger pictures. It was, however, the best room that could be procured for the purpose. Here were shown forty-five pictures, including one or two drawings. There was something peculiarly happy in this exhibition of works by a single mind. On entering, the presence of the artist seemed to fill the room. The door-keeper held the door, but Allston held the room; for his spirit flowed from all the walls, and helped the spectator to see his work aright. This accompaniment of the artist's presence, which hangs about all truly artistic works, is disturbed in a miscellaneous collection, where jarring influences contend, and the worst pictures outshine and outglare the best, and for a time triumph over them. But in this exhibition no such disturbance met one, but rather one was received into an atmosphere of peace and harmony, and in such a temper beheld the pictures.