Effect of temperature, density, and strength of electric current on the spectra of gases

Abstract

Light may be defined as that vibration of the ether which, acting on the organ of sight, produces in us the sensation of vision. But when, on reflection, we realize that the sense of sight is the most useful of all man’s senses, and recall to mind how slowly we have come to understand that kind of energy which makes the organ of sight so useful, then we are prone to exclaim, How strange that man through all the many centuries should be totally ignorant of the various phenomena of light, the study of which has been the revelation to him of so many hidden mysteries!