The word "decoration," however appropriate to fantastic ornaments, and in some degree to insulated figures, has, as you know, been considered vilifying when applied to works that are addressed to the mind. But, as we have no other term, we must consent to use it in both meanings. It is, indeed, important to remember, that no works of art, however elevated, can dispense with the appeal, the impressive or winning appeal, to the eye. Thus much for our definition of terms. As a general principle in decoration, I would recommend that the eye should be solely or chiefly addressed where a passing glance only can be given to the work, and that the attention should be more taxed where leisure and surrounding circumstances permit or invite contemplation. The reverse of this would be manifestly wrong; but the recommendation itself is not to be understood too literally. Every display has its legitimate exuberance: the "over and above" in decoration can only be that of quality, for mere taste is supposed to define all that relates to quantity. As common poetic description sometimes exalts its subject less by accumulation than by supposing costly materials where mean ones would do, so in art the augmenting excellence ascends from sense to thought. If, therefore, the intention to afford mental pleasure is very apparent even in situations where this may appear superfluous and in a manner thrown away, the impression must of itself be elevating. But the indispensable condition is, that a gradation should still be maintained; that higher excellence should still be in reserve. What must be the character of works of art to which Raphael's Corridor in the Vatican forms the mere approach? The answer is given by the perfection of the works in the Stanze. All that is to be insisted on, therefore, is a due gradation in conformity with the principle first proposed. In the remarks that follow, I cannot strictly follow the plan of the house, but must often generalize; the observations submitted, if tenable at all, will, however, be easily applicable to your purpose.