The "positive philosophy" has been shown by Professor Fiske to be much misunderstood, misapprehension not being confined solely to the ranks of its opponents. His exposition of some of the misconceptions on which Professor Huxley has based some criticisms upon the writings of Comte, strikes us as especially forcible; and the whole course of lectures proves Professor Fiske to be one of the clearest and most able of American thinkers. These lectures are followed as they appear, with great interest, and their publication in the World we regard as a real and permanent benefit to the public. * * * * * SCIENTIFIC LECTURES BEFORE THE AMERICAN INSTITUTE. The announcement of these lectures came to hand too late for our last issue, and the first has already been delivered. The course is as follows: Friday, Dec. 17, The Battle Fields of Science, by Andrew D. White, President of the Cornell University, Ithaca, N.Y. Friday, Dec. 24, How Animals Move, by Professor E. S. Morse, of the Peabody Academy of Science, Salem, Mass. Friday, Dec. 31, The Correlation of Vital and Physical Forces, by Professor G. F. Barker, of Yale College, New Haven. Friday, Jan. 7, The Air and Respiration, by Professor J. C. Draper, of the College of the City of New York. Friday, Jan. 14, The Connection of Natural Science and Mental Philosophy, by Professor J. Bascom, of Williams College, Williamstown, Mass. Friday, Jan. 21, The Constitution of the Sun, by Dr. B. A. Gould, of Cambridge, Mass. Friday, Jan. 28, The Colorado Plateau, its Canons and Ruined Cities, by Professor J. S. Newberry, of Columbia College, New York. The course is a good one, and ought to be, and doubtless will be, well attended. Abstracts of the lectures will appear as delivered, in the SCIENTIFIC AMERICAN. * * * * * THE BATTLE FIELDS OF SCIENCE. LECTURE BY PROFESSOR WHITE, BEFORE THE AMERICAN INSTITUTE.