RECENT DISCOVERIES IN RADIATION AND THEIR SIGNIFICANCE.
The Discovery of X-rays.
The Discovery of Radio-activity.
The Discovery of Radium.
The Nature of Cathode Rays.
Cathode Ray Particles Much Smaller than the Smallest Known Atom.
A New Theory as to the Constitution of Matter.
The Nature of X-rays.
Radio-active Substances emit Cathode Rays.
Other Radiations from Radio-active Substances.
The Nature of the Alpha Rays.
The Crookes Spinthariscope.
The Continuous Emission of Light and Heat by Radio-active Substances.
Radio-activity a Manifestation of Subatomic Energy.
The Production of Uranium X.
The Emanation from Radium.
The Disintegration of the Atom of Radio-active Substances.
The Birth of Helium.
The Life of Radium.
The Transmutation of the Elements.
PROFESSOR R. A. MILLIKAN
THERE are times when the atmosphere seems to be fairly saturated with the spirit of scientific discovery. Such a time existed during the opening years of the nineteenth century when John Dalton was putting the atomic theory of matter upon an experimental rather than upon the purely speculative foundation upon which it had previously rested; when Count Rumford, an American by birth, was laying the corner-stone of the modern mechanical theory of heat, in accordance with which heat consists in the vibratory motion of the particles of which matter is composed; when Thomas Young was forging the final links in the chain of proof that light consists in the wave motion of some all-pervading medium, the ether.
THAT men, or thinking beings akin to man, exist only on that minute fragment of the universe we call the earth is a conception so highly improbable, in view of the vast multitude of planets which we may logically conceive to exist, that it seems as if no reasoning being could entertain it.
THE same restless energy which impelled the American people to become a world-power has led their men of science to extend the range of their researches. The possibilities of a nation’s influence are bounded only by the whole earth; and in a similar way the field of astronomy is limited only by the whole sky.
THE ROYAL PRUSSIAN ACADEMY OF SCIENCE AND THE FINE ARTS. BERLIN.
EDWARD F. WILLIAMS
UNDER the patronage of the new king, which was continued with increasing sympathy during the forty-six years of his reign, the academy in Berlin acquired world-wide influence. The Literary Society of Berlin, which had been a serious rival, was united with it, and the new organization was named The Royal Prussian Academy of Science and the Fine Arts.
THE INFLUENCE OF LIEBIG ON THE DEVELOPMENT OF CHEMICAL INDUSTRIES.*
DR. CARL DUISBERG
THE chemical industry is a child of the nineteenth century. The inorganic branch, the so-called industry of heavy chemicals, such as the manufacture of sulphuric acid in lead chambers, the manufacture of nitric acid, of hydrochloric acid, of sulphate, the manufacture of soda according to Le Blanc’s process, the manufacture of chlorine and bleaching powder according to the processes of Deacon and Weldon, was already in operation in the first part of the nineteenth century, while the organic branch of the industry, the manufacture of coal-tar products, of the organic intermediary products, of the aniline and alizarine dyestuffs, pharmaceutical and photographic preparations, the artificial sweeteners and artificial perfumes, and the whole crowned by the synthesis and manufacture of indigo on a large scale, became known only in the latter part of the last century.
THE CONSERVATION OF ENERGY IN THOSE OF ADVANCING YEARS. III.
How to Postpone the Degenerative Effects of Old Age.
J. MADISON TAYLOR
A REVIEW of the foregoing phenomena of advancing years points clearly to the line upon which these may be in part controlled or delayed. It is not to be expected that we can secure the cooperation of most, or indeed many, people in pursuing preventive measures.
CONTROL of trade routes and mineral supplies have been the two chief factors in determining the industrial and political supremacy of races and nations. It is evident that a third—the control of the food supplies from the tropics—will soon be equally vital to civilized man.
AT Luray, Page County, Virginia, is located a health resort which represents an idea unique in hospital or sanitarium construction. The dwellers in Limair may keep their doors and windows closed summer and winter, and still breathe air as pure as that of the mountain side.
THE STUDY OF THE SCIENCES AND OF LATIN IN THE SECONDARY SCHOOLS.
PRIESTLEY died on February 6, 1804, and the centenary of his death has been commemorated in Great Britain and in the United States. Thirty years ago the centenary of the discovery of oxygen was celebrated, and at that time this magazine published several articles on the life and work of Priestley, In the issue for August, 1874, a biographical sketch and an appreciation by Dr. John W. Draper will be found.
NAMES OF CONTRIBUTORS ARE PRINTED IN SMALL CAPITALS.
Aerial Navigation, 94; O. CHANUTE, 385. Air of the Luray Caverns, GUY L. HUNNER, 557. Agriculture, Southern, its Conditions and Needs, D. D. WALLACE, 245; Department of, at Washington, New Building for, 479. Alaska, The Salmon and Salmon Streams of, DAVID STARR JORDAN, 165.