Many are familiar with the light of the firefly or of its larv\u00e6, the glow-worm, but few persons realize that a vast number of insects 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, <\/p>\n\n\n\n
“Why are these lowly organisms endowed with such a wonderful ability?”<\/p><\/blockquote>\n\n\n\n\n\n\n\n
Despite his highly developed mind and body and his boasted superiority,\nman must go forth and learn the secrets of light-production before he\nmay emancipate himself from darkness. If man could emit light in\nrelative proportion to his size as compared with the firefly, he would\nneed no other torch in the coal-mine. How independent he would be in\nextreme darkness where his adapted eyes need only a feeble\nlight-source! Primitive man, desiring a light-source and having no means\nof making fire, imprisoned the glowing insects in a perforated gourd or\nreceptacle of clay, and thus invented the first lantern perhaps before\nhe knew how to make fire. The fireflies of the West Indies emit a\ncontinuous glow of considerable luminous intensity and the natives have\nused these imprisoned insects as light-sources. Thus mankind has\nexhibited his superiority by adapting the facilities at hand to the\ngrowing requirements which his independent nature continuously\nnourished. His insistent demand for independence in turn has nourished\nhis desire to learn nature’s secrets and this desire has increased in\nintensity throughout the ages.<\/p>\n\n\n\n
The act of imprisoning a glowing insect was in itself no greater stride\nalong the highway of progress than the act of picking a tasty fruit from\nits tree. However, the crude lantern perhaps directed his primitive mind\nto the possibilities of artificial light. The flaming fagot from the\nfire was the ancestor of the oil-lamp, the candle, the lantern, and the\nelectric flash-light. It is a matter of conjecture how much time elapsed\nbefore his feeble intellect became aware that resinous wood afforded a\nbetter light-source than woods which were less inflammable.\nNevertheless, pine knots and similar resinous pieces of wood eventually\nwere favored as torches and their use has persisted until the present\ntime. In some instances in ancient times resin was extracted from wood\nand burned in vessels. This was the forerunner of the grease-and the\noil-lamp. In the woods to-day the craftsman of the wilds keeps on the\nlookout for live trees saturated with highly inflammable ingredients.<\/p>\n\n\n\n
Viewed from the present age, these smoking, flickering light-sources\nappear very crude; nevertheless they represent a wide gulf between their\nusers and those primitive beings who were unacquainted with the art of\nmaking fire. Although the wood fire prevailed as a light-source\nthroughout uncounted centuries, it was subjected to more or less\nimprovement as civilization advanced. When the wood fire was brought\nindoors the day was extended and early man began to develop his crude\narts. He thought and planned in the comfort and security of his cave or\nhut. By the firelight he devised implements and even decorated his stone\nsurroundings with pictures which to-day reveal something of the thoughts\nand activities of mankind during a civilization which existed many\nthousand years ago.<\/p>\n\n\n\n
When it was too warm to have a roaring fire upon the hearth, man devised\nother means for obtaining light without undue warmth. He placed glowing\nembers upon ledges in the walls, upon stone slabs, or even upon\nsuspended devices of non-inflammable material. Later he split long\nsplinters of wood from pieces selected for their straightness of grain.\nThese burning splinters emitting a smoking, feeble light were crude but\nthey were refinements of considerable merit. A testimonial of their\nsatisfactoriness is their use throughout many centuries. Until very\nrecent times the burning splinter has been in use in Scotland and in\nother countries, and it is probable that at present in remote districts\nof highly civilized countries this crude device serves the meager needs\nof those whose requirements have been undisturbed by the progress of\ncivilization. Scott, in “The Legend of Montrose,” describes a table\nscene during a feast. Behind each seat a giant Highlander stood, holding\na blazing torch of bog-pine. This was also the method of lighting in the\nHomeric age.<\/p>\n","protected":false},"excerpt":{"rendered":"
Many are familiar with the light of the firefly or of its larv\u00e6, the glow-worm, but few persons realize that a vast number of insects 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 … <\/p>\n