For a short one-act piece, the mere txhibition of a characteristic pecu- liarity, or of some delicate social position, will often suffice, with a mini- mum of progressive plot. Some of the elegant little vantlevilles,in which Mademoiselle Rose-Cheri acts so charmingly, may be cited as cases in point; and we have lately had another—doubtless adapted from the French —at the Lyceum. The author exhibits a female, totally uneducated, al- most uncouth in her manners, and raised into a false position by a marriage above her station; and then' by endowing her -with genuine good-humour and kindliness and placing by her side a cultivated lady, who in a refined manner conceals something like a conjugal infidelity, he makes her corn- . Aland the respect of the audience. There is nothing new in a contrast be- tween native simplicity and social refinement made for the glory of the rormer. Sandford and Merlon was a famous instance of this principle; and ponth were almost taught to believe that bad manners were the summit of moral excellence. The Rough Diamond—so is the new piece called—is, however, a very pretty little production: the position of the heroine is cleverly brought forward, and she is represented by Mrs. Fitzwilliam in a very natural and genial manner. Buckstone acts the part of a totally un- bultivated country cousin, who exhibits the broadly droll side of " rough- diamondism," and thereby excites hearty laughter.