“The National Association for the Advancement ol Education," met at the city ot Pittsburgh, Pa., on the 9th inst., and had an interesting time of it. Professor Henry, of the Smithsonian Institute was chosen Chairman, and made an excellent introductory speech, in which he gave a sketch of his own life. He has been a watchmaker, schoolteacher, engineer, and professor in a college. On the second day Prof. S. S. Haldeman, of Pa., delivered a fiery and able address on the ignorance of science displayed by poets and mere literary men, and the evil resulting from the same. He believed that the judgment the most important faculty of the mindwas not so much cultivated as the imagination. The judgment could only be cultivated by a study of physical and natural science, while the imagination thrived on fiction; the former dealt with rigid truth, the latter with slipshod falsehood. He exposed the ignorance of science displayed by Montgomery in the poem of the Pelican Island, wherein he in- troduces a " {nautilus" as sailing on seas where it is never found. Goldsmith, the poet —a reader only of scientific works, ignorantly escribed the crab and the tortoise as belong-ng to the same class, and Mrs. Sigourney svrote of the zoophytes as insects. In a room )f 50 or 60 students studying Butler's Analo-gy, he had heard the question asked, " how Tiany legs has a fly ?" and not one could answer it. He gave the shallow literati of the press a severe flagellation about the Paine Light. He said :— " Education should teach us to think, not to magine. The prominence given to imagina-;ion crowds the world with superficial pre-enders, expounders of false reforms, educated people who were never taught to reason.— We flatter ourselves upon our intelligence, yet we have seen almost the entire newspaper press—that index of the public mind—giving :redence to the unphilosophical, but (to the She ignorant) plausible, explanation of the apparatus to produce the Paine light; in which ihe prominent feature of its tremendous pow-?? was increased weakness. Mathematics keeps its votaries so perfectly in the proper track, that they are not generally good inves-iigators where observation and judgment are required, and we consequently find that mere mathematicians are generally not remarkable for making logical deductions in general sciences, although mathematics is the most logical of the sciences. It is only when the mathematician cultivates the sciences of observation that we see the triumphs of the human mind, as in astronomical research, where minute observation, careful manipulation, exact comparison, and profound judgment are brought into action. Research in other branches of natural philosophy, in mechanics, engineering, natural history, and chemistry, also bring the reasoning powers into activity, and afford facilities to a much greater number of inquirers." He also gave Harper's Magazine a severe drubbing for dabbling in science, in an article for July, on shells, which he characterized as " a tissue of absurdities." He also gave Putnam's Magazine a rebuke for some mistakes in treating of the natural sciences. The object of the professor was to show the evils of imaginative studies, by giving them a too prominent place in education. Bishop Potter replied to the professor, and considered the arguments presented to be against the study of natural sciences in schools. A number of others came up to the defence of poetry and imaginative literature; but Prof. Haldeman was right. The true alone is the beautiful, and poets and literary men, when they write upon any subject, should understand it or keep mum. It is indeed true that too many men write about subjects (making a great pretence to profundity) of which they are perfectly ignorant, and we have had abundant evidence of the truth of what we say in respect to the very case mentioned by Professor Haldeman. When the Ericsson also created such an excitement in the months of last January and February, and nearly the whole newspaper press of this city, in their ignorance of science, became non compus mentis about " the good time coming," the " Philadelphia Ledger " stated that the " Scientific American" stood alone, ns it did on the Paine Light, when it had an array of talent equally great against it, and it, the " Ledger," would wait for future developments. The result has justified the confidence which that paper reposed in our opinions, and yet for all this, we do not pretend to be perfect—all men are liable to make mistakes. There is a great and general ignorance of science and philosophy, but this, we believe, is not owing, as Professor Haldeman said, to the super cultivation of the imagination, but the general disinclination in mankind to severe mental toil. Literary Notices Elements of Anatomy and Physiology—By Justin R. Loomle ; New York City : Lamport, Blakeman & Law. A very good book—the beet book of its size, treating upon these important subjects, we have ever seen. There is a dignity and conciseness about the style which admirably fit it for its purpose. We have looked in vain for the diffuseness diluted and the senseless repetitions of some of our popular text books. We expect for Prof. Loomis a brilliant success as a book maker. Minifie's Mechanical Drawing Book—For Belt-instruction. Part 10. A useful and practical work. Published by Wm. Minifie, Baltimore ; De-witt & Davenport, New York, agent. Mark Hoedlestone ; or, The Two Brothere—By Mrs. Moodie, author of " Roughing it in the Bush," u Enthusiasm," &c. Dewitt & Davenport, publishers, 156 Nassau st, New York. This is a work of consummate interest; and is written in a style of elegant refinement, characteristic of the gifted au-thorers, who is a sister of the celebrated Agnes Strickland. It forms a 12mot book of over 350 pages, on excellent white paper and in faultless typography.