Dr. Delany has long been before the public. His first appearance, we believe, was in connection with _The Mystery_, a weekly newspaper published at Pittsburg, and of which he was editor. His journal was faithful in its advocacy of the rights of man, and had the reputation of being a well-conducted sheet. The doctor afterwards was associated with Frederick Douglass in the editorial management of his paper at Rochester, N. Y. From the latter place he removed to Canada, and has since resided in Chatham, where he is looked upon as one of its leading citizens. Dr. M. R. Delany, though regarded as a man high in his profession, is better and more widely known as a traveller, discoverer, and lecturer. His association with Professor Campbell in the "Niger Valley Exploring Expedition" has brought the doctor very prominently before the world, and especially that portion of it which takes an interest in the civilization of Africa. The official report of that expedition shows that he did not visit that country with his eyes shut. His observations and suggestions about the climate, soil, diseases, and natural productions of Africa, are interesting, and give evidence that the doctor was in earnest. The published report, of which he is the author, will repay a perusal. On his return home, Dr. Delany spent some time in England, and lectured in the British metropolis and the provincial cities, with considerable success, on Africa and its resources. As a member of the International Statistical Congress, he acquitted himself with credit to his position and honor to his race. The foolish manner in which the Hon. Mr. Dallas, our minister to the court of St. James, acted on meeting Dr. Delany in that august assembly, and the criticisms of the press of Europe and America, will not soon be forgotten. He is short, compactly built, has a quick, wiry walk, and is decided and energetic in conversation, unadulterated in race, and proud of his complexion. Though somewhat violent in his gestures, and paying but little regard to the strict rules of oratory, Dr. Delany is, nevertheless, an interesting, eloquent speaker. Devotedly attached to his fatherland, he goes for a "Negro Nationality." Whatever he undertakes, he executes it with all the powers that God has given him; and what would appear as an obstacle in the way of other men, would be brushed aside by Martin R. Delany. ROBERT SMALL.