The Birmingham age-herald., 1915-04-04

out lines peculiar to itself; fourthly, if, the light of an incandescent solid or liquid passes through gaseous body, certain of it's rays are absorbed and black lines in the spectrum indicate the nature of the substance which absorbed the ray; fifthly, each element, when gaseous and incandescent, emits bright rays iden- tical in color and position in the spectrum with those which it absorbs from light transmitted through it.
 The spectrum of sodium, for instance- shows two bright lines which correspond in position with the double black line at D (the sodium line) Now applying these principles to the solar spectrum, investi- gators found, from the nature and pos sition of the rays absorbed, that its light passes through hydrogen, potassium, sodium, calcium, barium, magnesium. zinc, iron, chromium, cobalt, nickel. copper and manganese, all in a state of gas and constituting part of the solar en- velope, whence they conclude that these bodies are present in the substance Of the sun itslf, from which they have been volatilized by heat.
 The incandescent vapor of each ele- mentary substance has a characteristic spectrum consisting of fixed lines, which never CQanSeS. spectrum dudlySlS, dS this is called, furnishes the chemist with an exquisitely delicate test to enable him to detect the presence of minute quan- itities of elementary bodies. For instance, by heating any substance until it becomes gaseous and incandescent, he is able by means of the lines to read off from the spectrum the various elements present in the vapor. By this means several new elements have been discovered
 Photography has been of very great assistance to the spectroscopist by the means it has given him of not only mak-, ing rapid and correct representation of the spectrum lines, but also in showing him number of lines of very great im- portance situated in the ultraviolet parts of the spectrum, and which are totally invisible to the eye
 Professor Nicholson has long been known as one of the most distinguished of American scientists. In 1907 he res ceived the Nobel science prize, sum of $40 0000, for his researches into the nature of light. This is generally regarded as the highest international honor paid to scientists at the present time. It has been given to such men as Professor Roentgen, the discoverer of the Roentgen rays, and to Alexis Carrel, for his achievement in keeping animal tissues alive when separated from the body.
 Few American scientists are moro highly esteemed in Europe than Michel son. He has received a long list of honors from foreign scientific bodies, in. cluding the coveted Copley Medal of the Royal Society of London.
 He was born in 1852, entered the United States Navy in 1S73 and served as an officer. He became an instructor in physics at the Naval Academy in 1875. Since then he has held many university positions, and he has been head of the department of physics at the University of Chicago since 1892.
 A very interesting personal fact about Professor Nicholson is that in spite of his sixty-three years and his tremendous scientific labors he is very fine athlete. Indeed, he believes that he would not have been able to do his scientific work so efficiently if he had not kept in con. stant physical training
 He is particularly good tennis player and comparatively few of the younger men at the university can beat him at that game.