Excerpt from Half-Hour Recreations Popular Science: First Series Absorption bands, 95. Absorption of light, si, 82, 84, 85. 102. Absorption of light by solid bodies, 84, 85. Absorption spectra, 89. Actinic ray, 478. Actinism, 477, 478. Actinoid polyps, 179, 180. Activity ofcorallines, 457. Admiral Smyth on Euler, I3. Adventure of Christian Borer, 466, 467. Aerial Vibrations, 428. Aflinity between comets and meteors, I7c 172. Aggregate body of water on the earth, 456. Albert Achilles, 23. Albert the Great, 37. Algae, 179, 180. Allah's wul, 462. All developments a process of dissimilariza tion, 38, 39' All investigation led but to conjecture, so. Amphioxus, 47. Analogy between light and sound, 73. Analogy between musical sounds and col ors, 77 Analysis of stellar light, 275. Analysis of the blood, 377, 378. Analysis of the sun's light, 97. Anecdote, 191, 192. Angstriim researches, 8-10, Iz - I4, 80, 86, 92 Animal life at great depths in sea, 403-405. Annular nebula in Lyra, x47. Antiquity of drift implements, 333. Apparently obvious relation long over looked, 35. Appert's discovery, 297. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.