As these two qualities, relief and fulness of effect, can hardly exist together, it is not very difficult to determine to which we ought to give the preference." "Those painters who have best understood the art of producing a good effect, have adopted one principle that seems perfectly conformable to reason--that a part may be sacrificed for the good of the whole. Thus, whether the masses consist of light or shadow, it is necessary that they should be compact, and of a pleasing shape; to this end some parts may be made darker and some lighter, and reflections stronger than nature would warrant." He instances a "Moonlight" by Rubens, now, we believe, in the possession of Mr Rogers, in which Rubens had given more light and more glowing colours than we recognize in nature,--"it might easily be mistaken, if he had not likewise added stars, for a fainter setting sun." We stop not to enquire if that harmony so praised, might not have been preserved had the resemblance to nature been closer. Brilliancy is produced. The fact is, the _practice_ of art is a system of compensation. We cannot exactly in all cases represent nature,--we have not the means, but our means will achieve what, though _particularly_ unlike, may, by itself or in opposition, produce similar effects. Nature does not present a varnished polished surface, nor that very transparency that our colours can give; but it is found that this transparency, in all its degrees, in conjunction and in opposition to opaque body of colour, represents the force of light and shade of nature, which is the principal object to attain. _The_ richness of nature is not the exact richness of the palette. The painter's success is in the means of compensation.