Page:Popular Science Monthly Volume 12.djvu/129

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119
POPULAR MISCELLANY.

within a certain distance from us, the light from the stellar masses would predominate over that of the gaseous envelope. The spectrum would, therefore, be an ordinary stellar spectrum. Suppose such a cluster to be removed farther and farther from us, the light from each star would be diminished in proportion of the inverse square of the distance; but such would not be the case with the light from the enveloping surface formed by the gaseous envelopes. The light from this envelope received on a slit in the focus of an object-glass would be sensibly constant because the contributing area would be increased in the same proportion that the light from each part is diminished. The result would be that, at some definite distance, and all greater distances, the preponderating light received from such a cluster would be derived from the gaseous envelopes and not from the isolated stellar masses. The spectrum of the cluster would, therefore, become a linear one, like that from the gaseous surroundings of our own sun.

 

Duration of the Flight of Bees.—To determine the length of time that bees can continue to fly about, Dönhoff took some of those insects from a hive, just as they came out of the entrance-hole, and placed them under a glass bell at a temperature of 66° Fahr. First they ran hastily up and down the sides of the glass, and flew about in the jar. Their movements grew gradually slower, and after forty-five minutes they all sat quietly together, or moved very slowly and clumsily, and were unable to fly. On being allowed to crawl upon a pencil, and then thrown off, they fell down perpendicularly without moving their wings. On killing one or two, the honey-bags were found to be empty. The author then fed the others with a sugar solution, and after three or four minutes threw some of them into the air. They were now able to use their wings a little. A minute or two later they appeared to be as lively as ever. The author remarks that if the temperature is under 66° Fahr. the bees lose the power of flying even sooner, and recover it more slowly. With higher temperatures the power returns sooner. Dönhoff's conclusion from these observations is that the bee "loses the power of flying because it does not possess the necessary strength to be converted into muscular action, and that this strength returns to its system because in sugar it finds the necessary vital support."

 

Singing-Flames and Inaudible Vibrations.—"Singing-flames" are known to be sensitive to the faintest sounds, provided the rate of vibration of the latter is sufficiently high. But are they equally sensible to vibrations that are so rapid as to be inaudible? This question has been studied by Prof. W. F. Barrett, and the results of his experiments, as stated by him in a communication to Nature, will be read with interest. Prof. Barrett employed a flame produced by coal-gas contained in a holder under a pressure of ten inches of water, and issuing from a steatite jet having a circular orifice of 0.04 inch diameter; the height of the flame when undisturbed was just two feet, but it fell to seven inches under the feeblest hiss or the clink of two coins. On sounding the lowest note of a "Galton whistle," little effect was produced on the flame; a shrill dog-whistle produced a slight forking, but that was all. Raising the pitch of the Galton whistle, the flame became more and more agitated, until when Prof. Barrett had nearly reached the upper limit of audibility of the left ear, and had gone quite beyond the limit of the right, the flame was still more violently agitated. Raising the pitch still higher, till he had quite ceased to hear any sound, he was astonished to observe the profound effect produced on the flame. At every inaudible puff of the whistle it would fall fully sixteen inches, and give its characteristic roar, at the same time losing its luminosity, and, when viewed in a revolving mirror, presenting a multitude of ragged images, with torn sides and flickering tongues. Nor was this effect sensibly diminished by a distance of some twenty feet from the flame; even at fifty feet the effect was very pronounced.

 

Functions of the Cerebellum.—The researches and experiments of Flourens have been considered conclusive as to the coordinative function of the cerebellum in animal movements. That eminent physiol-