Artificial light - 1920 Author:Matthew Luckiesh Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: in PRIMITIVE LIGHT-SOURCES Many are familiar with the light of the firefly or of its larvag, the glow-worm, but few persons realize that a vast number of i... more »nsects and lower organisms are endowed with the superhuman ability of producing light by physiological processes. Apparently the chief function of these lighting-plants within the living bodies is not to provide light in the sense that the human being uses it predominantly. That is, these wonderful light- sources seem to be utilized more for signaling, for luring prey, and for protection than for strictly illuminating-purposes. Much study has been given to the production of light by animals, because the secrets will be extremely valuable to mankind. As one floats over tide-water on a balmy evening after dark and watches the pulsating spots of phosphorescent light emitted by the lowly jellyfishes, his imaginative mood formulates the question, "Why are these lowly organisms endowed with such a wonderful ability1?" Despite his highly developed mind and body and his boasted superiority, man must go forth and learn the secrets of light-production before he may emancipate himself from darkness. If man could emit light in relative proportion to his size as compared with the firefly, he would need no other torch in the coal-mine. How independent he would be in extreme darknesswhere his adapted eyes need only a feeble light-source! Primitive man, desiring a light-source and having no means of making fire, imprisoned the glowing insects in a perforated gourd or receptacle of clay, and thus invented the first lantern perhaps before he knew how "to make fire. The fireflies of the West Indies emit a continuous glow of considerable luminous intensity and the natives have used these imprisoned insects as light-sources. Thus mankind ha...« less