CARL IMMERMAN'S _Theater-Briefe_ (Letters on the Theatre), says a German critic, "is interesting not only as a history of a German theatre, but as an excellent addition to the literature of æsthetic criticism. This work refers more especially to the years 1833-37, during which time, as is well known, Immerman attempted to establish in Düsseldorf an _ideal_ theatre, somewhat in the style of that at Weimar." We have frequently, in conversation with a gentleman who held an appointment in this Düsseldorf _Ideal Theatre_, received amusing and interesting accounts of Immerman's style of management. That his plan did not succeed is undoubtedly for the sake of Art to be regretted; yet we can by no means unconditionally approve of the ideas upon which Immerman based his theories. He was certainly right in endeavoring to form a unity of style in dramatic representations; but how he could have deemed such an unity possible, when grounded upon such diametrically opposed æsthetic bases as those of Shakespeare and Calderon, is to us unintelligible. The remarks on the most convenient and practical style of executing certain pieces--for example, Hamlet--are worthy of attention, as also a few explanations relative to Immerman's own dramatic conceptions. * * * * * KOHL, whose innumerable and well-known books of travel have caused him to be cited even in book-making Germany as an instance of _Ausserordentlichen Fruchtbarkeit_, or extraordinary fertility, has published, through Kuntze of Dresden, yet another work, entitled _Sketches of Nature and Popular Life_, which is however said to be inferior to the average of his works--principally, we imagine, from his falling into the besetting sin of German writers since the late revolutions, namely, of talking politics when he should have quoted poetry. We should not be surprised to find some day a treatise on qualitative chemistry, commencing with an analysis of the Prussian constitution, or an anatomical work, concluding with a dissection of Germany in general. Kohl possesses, however, great faculties of observation, is an accurate describer, and has, perhaps, done as much as any man of the age towards making different countries acquainted with each other. * * * * * The friends of the Italian language and literature, will do well to cast an occasional kindly glance on _L'Eco d'Italia_ (The Echo of Italy), an excellent weekly paper published by Signor SECCHI DE CASALI, in this city, at number 289 Broadway. Many admirable poems find their way from time to time into this periodical, while its foreign correspondence is of a high order of merit. * * * * *