THE importance of Chilean nitrate depends on a curious whim of nature. Nitrogen is needed by all plants and animals, and though the atmosphere is nearly four-fifths nitrogen, few plants and no animals can draw directly on that universal supply.
IT has been a matter of more or less common observation from time immemorial that plants possess the power to overcome obstacles. Some species of trees are not particular where they grow if there is enough soil and moisture, their roots often seeking places where apparently insurmountable obstacles must be overcome.
THE ABSORPTION AND EMISSION CENTERS OF LIGHT AND HEAT.
BLACK BODY RADIATIONS AND ELECTRON ATMOSPHERES
SELECTIVE RADIATION AND ABSORPTION
AN IDEAL OF THE ILLUMINATING ENGINEER
DEFINITION OF EMISSION AND ABSORPTION CENTERS
THE PROBLEM OF LIGHT AND HEAT CENTERS
SOME METHODS OF APPROACHING THE PROBLEM
POSSIBLE STRUCTURE OF LIGHT AND HEAT CENTERS
IONIZATION AND LIGHT EMISSION AND ABSORPTION
CARRIERS OF SPARK; SPECTRA
NEGATIVE ELECTRONS AS EMISSION AND ABSORPTION CENTERS
THE POSITIVE ELECTRON
ABSORPTION CENTERS OF SOLUTIONS OF THE RARE ELEMENTS
CENTERS OF PHOSPHORESCENT SPECTRA
THE LIGHT CENTERS OF ORGANIC COMPOUNDS
DR. W. W. STRONG
THE mechanical motions of nature are transmitted by solids and fluids from sources that consist of more or less well known mechanical systems. Waves on a pond may be due to a boat moving over the surface of the water. Sound waves in air may be due to the vibrations of a tuning fork.
ONE of the problems which has been definitely set for psychologists to solve during the twentieth century is the cause of the almost universal desire for alcohol. It is a curious fact that in the thousands and hundreds of thousands of books, articles and writings of every description relating to the many phases of the alcohol problem, this simple and fundamental question—Why do men desire alcohol?—has until recently never been carefully considered at all and even now has not been answered.
IT was in the autumn of 1911 that the press gave wide publicity to a meeting of college presidents, deans and professors convened in honor of the installation of the chancellor of a metropolitan university. At the dinner that closed the ceremonies one of the speakers, himself the president of another great university, assured the audience that being a university president was great fun since among other perquisites of the position was that of being able to dine on college professors.
IN the past several years a marked change has taken place in the attitude of colleges and universities toward the matter of entrance requirements. An examination of catalogues, articles and discussions, shows clearly the swinging of opinion from the former college view to the high school way of regarding the question.
WE have learned two great lessons in the construction of the Panama Canal. One is that with money, modern machinery and men who are healthy and happily situated there is hardly anything impossible in civil engineering and building. This matchless piece of work now nearing completion testifies to the constructive genius of man, and can not be studied at close range in all its colossal proportions without exciting wonder and admiration.
THE biologist, like other organisms, has been evolved. The mutations of the Greek and Roman period never established themselves as permanent stocks. They were crushed out by that rank growth of political and theological weeds that finally destroyed itself by its own vegetative excesses.
THE oceanic waters that lap our shores conceal beneath their tidal margin a wealth of animal and plant life that is surprisingly unfamiliar to those who are not actually students of marine biology. As terrestrial animals ourselves we live and move in the midst of a world of air-breathing creatures with which most of us have become tolerably familiar.