FREDERIC LOUIS JAHN, the celebrated German professor, who invented the modern system of gymnastics, is writing his personal memoirs. He is about seventy years of age, and his long life has been full of significant incidents. To those who seek a good acquaintance with the current belles-lettres literature of Germany, we can cordially recommend the _Deutsches Museum_, published semi-monthly at Leipsic, under the editorial care of Professor Robert Prutz and Wilhelm Wolffson, and sold in this city by Westermann, 290 Broadway. Each number contains eighty-five close pages, filled by some of the leading writers of German science, art and politics. In the number now before us, are articles by Gutzkow, Boech, the philologist, Berthold Auerbach, Emanuel Geibel and Julius Mosen. The entire range of politics, philosophy, antiquities, art, poetry, romances and literary criticism is included in the scope of the _Museum_, except that it is designed not for the learned world, but for the mass of the people, and accordingly aims at general not technical instruction. Among the art notices, we observe a brief criticism on the Gallery of Illustrious Americans, in which the lithography of the pictures is praised as well as the faces themselves. The critic is delighted with the energy, originality and freshness of character expressed in their features. * * * * * A valuable contribution to current political history is the _Verfassungskampf in Kurhessen_ (Constitutional Struggle in Electoral Hesse), by Dr. H. Graefe, which has just made its appearance in Germany. The conflict of the people and parliament and public officers, against the selfish, arbitrary and foolish Elector, is the turning point of recent German politics, and the defeat of the former after their patience and firmness, acting always within the limits of the constitution, had gained a decided victory, and compelled the faithless prince to fly the country,--a defeat accomplished only by the intervention of Austrian and Prussian troops, was the final downfall of every form of political liberty in Germany. Dr. Graefe has wisely abstained from treating the events of this crisis as a philosophical historian; they are too fresh, and his own share in them was too decided to allow him to undertake that successfully. He accordingly does little more than simply report the transactions in a compendious way, with all the documents necessary to a full understanding of the subject. Whoever wishes for a thorough apprehension of the German tragi-comedy, may derive aid from his work. * * * * *