29. Mechanical Powers. The Lever, 21. The Pulley, Wheel, and Axle, and Inclined Plane, 42 22. The Wedge and Screw. Friction, 44. The Earth, Ecliptic and Zodiac. 48. The Tides, explanation of, 49. Eclipses of the Moon and Sun, 50. Mars, Vesta, Juno, Pallas, and Ceres, 51. Jupiter, his Belts, Satellites, &c. 55. The Constellations. Hymn to the North Star, 119 62. Water, Composition of. Hydrogen Gas, 63. The Earths and Alkalies. Uses of Lime, 64. Acids and Salts. Mountains of Salt, 65. Simple Combustibles. Carbon. Metals, 66. Oxyds and Combustion. Exhilarating Gas, 72. Magnetism. Variation of the Needle, 73. Magnetical Experiments. Amusing Deceptions, 164 76. Mineralogy. Characters of Minerals, 77. Classification of Minerals. The Diamond, 88. Texture of Vegetables. Bark. Wood. Pith. Age 89. Sap and Secretions. Flowing of the Sap. Sugar, 198 111. Architecture, Advantages of,—Orders of, 112. Constitution of the United States, Sketch of, 113. Excellence of our Republican Government, 114. Intelligence of the People a Means of Safety to THE LITERARY AND SCIENTIFIC CLASS BOOK. LESSON 1. Intellectual Pleasures. Evolv'ed, unfolded, unrolled, thrown out, WHEN we think of what man is, not in his faculties only, but in his intellectual acquisitions, and of what he must have been, on his entrance into the world, it is difficult for us to regard this knowledge and absolute ignorance as states of the same mind. It seems to us almost as if we had to consider a spiritual creation or transformation, as wondrous as if, in contemplating the material universe, we were to strive to think of the whole system of suns and planets, as evolved from a mere particle of matter, or rising from nothing, as when originally created. We believe that they were so created, and we know that man, comprehensive as his acquirements are, must have set out in his intellectual career from absolute ignorance; but how difficult is it for us to form any accurate conception of what we thus undoubtingly believe! The mind, which is enriched with as many sciences as there are classes of existing things in the universe, which our organs are able to discern-the mind, which is skilled in all the languages of all the civilized nations of the globe, and which has fixed and treasured in its own remembrance, the beauties of every work of transcendent genius, which age after age has added to the stores of antiquity—this mind, we know well, was once as ignorant as the dullest and feeblest of those minds, which scarcely know enough, even to wonder at its superiority. That pleasure attends the sublime operations of intellect in the discovery of truth, or the splendid creations of fancy, |