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Page:Popular Science Monthly Volume 7.djvu/474

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THE POPULAR SCIENCE MONTHLY.

Moquin-Tandon has recorded a case of the phosphorescence of earth-worms, which lie noticed on a garden-walk at Toulouse. The worms were about an inch and a half in length, and looked like little rods of white-hot iron.

It would be out of place in the pages of this journal to discuss the merits of theories which have been advanced to account for animal phosphorescence. As we have already said, Science has not pronounced any final decision on the matter. Some philosophers look upon the light as the result of the slow combustion of some combination of phosphorus contained in the animal secretions; others believe it to be a direct manifestation of vital force, acting through special organs, much in the way that electricity is produced in the torpedo or gymnotus. No doubt the problem will ultimately be solved as we advance in the study of comparative anatomy, and, in the mean time, many experiments have been made, in the hope of assisting the solution. It has been found that the luminous matter will communicate its peculiar property to liquids or solids with which it may come in contact. The light is extinguished by a cold or boiling temperature, or by strong stimulants; it also disappears in vacuo but becomes visible again on the admission of the air; and it is increased by moderate heat, and by gentle stimulants. In respect to the glow-worm, the two smaller sacs of yellow matter which we described possess the curious property of shining uninterruptedly for several hours, after they have been removed from the living body, the light from other parts being extinguished immediately under similar circumstances. A simple galvanic current passed through water containing Noctilucæ produced no effect; but an electro-magnetic current, on the other hand, caused, after a short interval, a continuous and steady glow to issue from the water. The light disappeared at the end of a quarter of an hour, and could not be reproduced, the animalcules being evidently dead.—Chambers's Journal.

 

THE GLACIERS OF NORWAY.
By Prof. HENRY M. BAIRD.

A VISIT to Switzerland has of late become so easy and frequent an undertaking, that the glaciers around Mont Blanc and the Jungfrau have lost much of their romance and all their novelty. Every tourist climbs the Montanvert to enjoy the sensation of walking over the Mer-de-glace in midsummer, and creeps under the Rosenlaui to admire the deep-blue color of its icy vault. There is, however, another country which, in the number and beauty of its glaciers, is a formidable rival of Switzerland; but, lying as it does, out of the