Among more legitimate exploits in the way of doubling are to be accounted the late Mr. Charles Mathews's assumption of the two characters of Puff and Sir Fretful Plagiary in "The Critic;" Miss Kate Terry's performance both of Viola and Sebastian in "Twelfth Night;" Mr. Phelps's appearance as James the First and Trapbois, in the play founded upon "The Fortunes of Nigel;" and the rendering by the same actor of the parts of the King and Justice Shallow in "The Second Part of Henry IV." The worst that can be said for these performances is that they incline the audience to pay less heed to the play than to the frequent changes of appearance entailed upon the players. The business of the scene is apt to be overlooked, and regard wanders involuntarily to the transactions of the tiring-room and the side-wings. Will the actor be recognisable? will he really have time to alter his costume? the spectators mechanically ask themselves, and meditation is occupied with such possibilities as a tangled string or an obstinate button hindering the performer. All this is opposed to the real purpose of playing, and injurious to the actor's art, to say nothing of the interests of the dramatist. Illusion is the special object of the theatre, and this forfeits its magic when once inquiry is directed too curiously to its method of contrivance. Still doubling of this kind has always been in favour both with actors and audiences, and many plays have been provided especially to give dual occupation to the performers. Certain of these have for excuse the fact that their fables hinge upon some question of mistaken identity, or strong personal resemblance. The famous "Courier of Lyons," founded, indeed, upon a genuine _cause celebre_, was a drama of this kind. Here it was indispensable that the respectable Monsieur Lesurques and the criminal Dubosc, between whom so extraordinary a likeness existed that the one suffered death upon the scaffold for a murder committed by the other, should be both impersonated by the same performer. "The Corsican Brothers," it need hardly be said, narrated the fortunes of the twin-born Louis and Fabian dei Franchi, reasonably supposed to be so much alike that they could not be known apart. Mademoiselle Rachel appeared with success in a drama called "Valeria," written by Messieurs Auguste Maquet and Jules Lacroix, for the express purpose, it would seem, of rehabilitating the Empress Messalina. The actress personated Valeria, otherwise Messalina, and also Cynisca, a dancing-girl of evil character, but so closely resembling the empress that, as the dramatists argued, history had confounded the two ladies, and charged the one with the misdeeds of the other. "Like and Unlike," an adaptation from the French, in which, some years since, Madame Celeste was wont to perform at the Adelphi, is also a drama of the same class. But, indeed, works contrived for doubling purposes are numerous enough. And in this category may be included the elaborate