Page:Popular Science Monthly Volume 24.djvu/192

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that are consumed in a few hours. Oxygen is absorbed more rapidly than it is set free. We shall also have to give up the prevalent idea that a little verdure can improve the atmosphere of a room. The advantage of plants, as Dr. Pettenkofer remarks, is rather in their moral than in their physical influence. Public gardens are also desirable because they enliven the view. Even on hygienic grounds, we should be careful not to underestimate the importance of whatever acts upon the mind. We have endeavored, in this and a former essay,[1] to study clothing and the habitation, with particular reference to their relations with the atmosphere; but, even as thus limited, the subject has proved to be a very complex one, and in our progress we have struck upon more than one question that is still imperfectly elucidated. It may, however, not have been without use to attract attention to these questions, which demand new investigations. Hygienic societies are multiplying; departments of hygiene have been created in numerous cities; and the hygienic conferences which have been held at Paris, Turin, and Geneva, attest the growing interest that attaches to the development of a science all of whose conquests redound to our physical and moral profit. Every facility should be given for widening its scope and extending its sphere of action. Diseases that might have been avoided constitute the heaviest taxes that can be laid upon a city.—Translated for the Popular Science Monthly from the Revue des Deux Mondes.


EVERYBODY who watched the sun with a telescope last summer must have wondered at the great belt of spots lying across the southern part of the disk during the last half of July. Several of the spots and groups were of extraordinary size, and their arrangement was very singular. When the belt extended completely across the sun, there was visible at one time almost every characteristic form that sun-spots present. There was the yawning black chasm with sharply defined yet ragged edges, vast enough to swallow up the whole earth, with room to spare, and surrounded by a regular penumbral border as evenly shaded as an artist could have made it; there was the double or triple spot whose black centers, though widely separated from one another, were tangled, as it were, in one twisted and torn veil of penumbra, or connected by long, shadowy bands; there was the monstrous spot of grotesque form surrounded by a crowd of smaller spots of even more fantastic shape, and enveloped in a broad, irregular penumbra as bizarre and wonderful as the mighty sun-chasms inclosed

  1. "Popular Science Monthly" for October, 1883, p. 787.