The youthful artist has created a perfect _furore_ in musical circles—amateurs, professionals, _dilettanti_ and every body else; his talent is wonderful, and his improvement still more remarkable. He has, withal, the modesty which is the companion of true merit. His second concert was given at Niblo’s Saloon, on Thursday evening, and it was attended by as full and fashionable an audience as that which welcomed him on Tuesday evening. Mayseder’s grand variations were given for the second time, upon a single string; the second attempt was even more successful than the first, and the young artist gave the highest proof of genius in overcoming difficulties previously regarded as insurmountable. Another gem of the soiree was a duet for violin and piano-forte, by Julien and Richard Hoffman. It was capitally given and was encored. The vocal part of the concert was given by Mme. Commettant and M’lle. Henrietta Behrend. The enthusiasm of the audience at the matchless execution of Julien was unbounded. But an episode occurred yesterday which was more telling in its effects than the applause of the audience on Thursday evening. It was a grand “variation” in the form of five one thousand dollar bank notes, a gift to the young musical genius. The following extraordinary letters describe the affair: NEW YORK, April 21, 1854. _Master Paul Julien_: I have heard your delightful music in the Concert room, and you have had the kindness to play for myself and friends at my residence. In earlier life I strove to learn the violin, but I abandoned it as too difficult for me. Its intricacies are unconquerable to all save those who are inspired. I have heard of the extraordinary perseverance and severe pecuniary trials through which your father has passed, to impart to you, his only child, a musical education. And I deem the efforts of both father and son highly commendable, and truly worthy of encouragement. I therefore present you with five thousand dollars, which I trust will be consecrated to your intellectual, musical, and moral culture.—Sincerely, ORISON BLUNT. [_Turn over for Paul’s response._] New York, April 21, 1854. _My Dear Sir_:—Mere words, though brightly glowing with affection, could not express my grateful emotions for your unexampled munificence. Nor could the most stirring strains I ever expect to conceive, reflect the chords you have touched in my heart. I can only assure you, that I will be very studious, and fondly cherish you next to my father and mother. I may soon return to France, and if you should ever visit me, I am sure that my friends would cordially receive you, for your substantial kindness to me during my sojourn in a far distant land. Affectionately, PAUL JULIEN. Alderman Orison Blunt, Warren street, New York.