'BIANCA VISCONTI: OR THE HEART OVERTASKED.'--A successful tragedy, at the present day, is an event too rare to be passed over with indifference. The modern stage has been poverty-stricken so long, that it welcomes every thing in the shape of its natural food; although it is constantly reminded of its too credulous judgment, in the repeated nausea which it suffers from the flatulent and unsubstantial trash which its starved condition urges it to attempt to swallow. The American drama, if indeed we have any claim to such a possession, is such as may reasonably be expected, more lean and wretched than the drama of any of the more cultivated nations. But we _have_ no national drama, as yet, although we think the corner-stone of its structure has been laid, and that there is bright promise of a noble edifice, in the aspiring efforts of the many able writers whom a few years have brought to light, as well as in the encouragement which the taste of the American people seems inclined to afford to this branch of literature. The tragedy now before us, is the first dramatic effort of a pen whose easy and finished tracings have made its master, even in the spring-time of his life, well known to fame. A mere experiment, in this most difficult department of literature, is worthy of praise. Whoever has considered the difficulties attendant upon the production of a play, of any class of the drama, would shrink from the task of bringing an original tragedy before the public, unless urged on by that firm confidence which genius gives to its possessor, and upheld through all by the hope of that ample reward which must attend the successful dramatist. SCOTT, in his letters to a theatrical friend in London, often adverts to the restraining of taste which the purveying for conceited or interested actors and actresses demands at the hands of a dramatic author, whose success is at their mercy, not less than at that of those of the audience who come to the theatre with palled animal and spiritual appetites, to 'snooze off their dinners and wine.' An expressionless 'oratorial machine,' high in the '_supe_' department, whose delivery of the commonest matter of fact is Stentorian and Ciceronian, may have it in his power, by ludicrous _mal addresse_, to mar the best acting play, and to render ridiculous the most refined poetry; while a higher order of Thespian, by slumbering over a level part, in a villanously indifferent manner, inadmissible as acting, may jeopardize an entire drama. But to return to 'Bianca Visconti.'