Madame Grisi, who first saw the light, if theatrical records tell truth, in 1812, and in whose voice none, that we are aware of, have as yet pretended to discover a falling off. Whether twenty years of almost constant exercise, or the same period of comparative repose, be most favourable to the preservation of the singing faculties, we shall not decide. Madame Sontag, however, has never risked by disuse the rusting of her fine organ. At the different courts at which she resided, she invariably showed the utmost complaisance, and willingly contributed, for the pleasure of her friends--and, on occasion, for the purposes of charity--those treasures of song for which managers, before and since, have been glad to pay a prince's ransom. This season her voice is even fresher and more flexible than in 1849; and there can be no reason why the opera-loving public should not, for many years to come, applaud her as their chief favourite--unless, indeed, the very high rate of remuneration her talent commands should, by speedily realising her object in returning to the stage, induce her soon to quit it. We believe it is no secret that her present engagement secures her about fourteen thousand pounds for twelve months' performances--about thrice the salary of a secretary of state. The sum is a very satisfactory one; and, whatever the fortune Madame Sontag has lost, she has evidently at her disposal the means of rapidly amassing another of no mean amount. Who will give the odds that we do not again see her an ambassadress?