COBB'S JUVENILE READERS.--Mr. LYMAN COBB deserves well of his country, and especially of its juvenile citizens, for the several excellent school-books for the young which he has prepared with great industry and tact, and from time to time put forth. We find on our table his three progressive 'Juvenile Readers;' and judging from the necessarily cursory examination which we have been enabled to give them, we have no hesitation in pronouncing them the best works of their class we have ever encountered. The author has taken great pains so to arrange the different lessons as to lead the child by a regular gradation from easy to difficult reading; to adapt the subjects to his advancement; and to place before him such matter, and such only, as shall convey to the juvenile mind correct views, and just principles of morality. All words of variable or doubtful orthography are also carefully exhibited. There are numerous other important merits, and improvements upon kindred works, to which we have neither time nor space at present to allude, but which we hope our readers will take occasion to find and admire in the works themselves. Mr. CALEB BARTLETT, corner of Platt and Pearl-streets, is the New-York publisher of Mr. COBB's series. NEW MUSIC: 'THE FORSAKEN.'--Mr. J. L. HEWITT, 239 Broadway, has sent us '_The Forsaken_,' a song sung with effect by Mr. SINCLAIR, and written and _composed_ by JAMES LAWSON, Esq. The 'words' were originally furnished to the KNICKERBOCKER by their author, and were thence transferred to many American journals with cordial commendations. The music is, we think, of a highly pleasing character; and we are not surprised to learn that the 'Song' is in very general request. It is not given to _every_ clever man, we can tell our friend and correspondent, to excel both in poetical and musical composition, as himself has done in the instance before us. We know, for example, a poet 'of the first water' who failed, on a memorable evening not long ago, in improvising a solo for a jews'-harp, 'then and there being' in the hands of a legal friend, who was making the little instrument 'discourse most eloquent music' It was _rather_ a rich scene than otherwise.