The Human Eye and the Sun

The Human Eye and the Sun, ""Hot"" and ""Cold"" Light is a translation from the Russian language and is a reproduction of texts from Volume IV of S.I. Vavilov, president of the U.S.S.R. Academy of Sciences. The book deals with theoretical and practical developments in lighting techniques. The text gives a brief introduction on the relationship of the human eye and the sun, describing the properties of light, of the sun, and of the human eye. The book describes hot (incandescence) and cold light (luminescence) as coming from different sources. These two types of light are compared. The text also discusses the chemical production of light such as that produced when hydrogen peroxide and potassium ferricyanide are added to a solution of triaminophthalic hydrazide with alkali. A blue light will emanate, lasting for hours or days, and more importantly, the temperature of the vessel containing the mixture is relatively low. The book also evaluates the efficiency of the electric bulb in terms of conversion from the source — power producing coal — to line distribution, and actual luminescence. The book expounds on the benefits of a lighting method in the form of fluorescence. It also explains the properties of fluorescence. The book is of interest to students of physics, electronics, and electrical engineering. It can also be appreciated by the general reader with some interest in history and scientific discoveries.