Page:Popular Science Monthly Volume 8.djvu/787

Rh continue attached to the plant for a long time, and thus the observer at once perceives which plant has had the benefit of animal food. No difference in health or vigor could be detected between those which had had insects and those which had not. This, however, does not by any means decide the question whether the plants do or do not digest the insects. As Mr. Meehan remarks, the case of these plants is comparable to that of vegetarians and flesh-eaters among mankind; it is a question which class is the healthier. A plant, he said, might feed on insects, and yet be no healthier than those which lived as other plants did. But the author does not see how this faculty of catching and digesting insects could be developed by natural selection. "It is believed," said he,"that the power to catch insects is a developed one—a power not possessed by their predecessors—and developed according to the law of natural selection. Unless insect-catching can be shown to be an especial advantage, there is nothing to select." Among the many Droseras observed by Mr. Meehan on this occasion, only one presented the phenomenon of the leaf bending over on itself, and so enfolding the prey.

The Soda-Lakes of Wyoming.—An account of the soda-lakes of Wyoming Territory is given in the report of Mr. Pontez, geologist of the Union Pacific Railroad. He describes two such lakes, the larger one covering about 200 acres. The average depth of water in this lake is three feet, and its specific gravity 1.097. The soda is nearly all carbonate. The second lake is situated near the first, and covers about $3 1⁄2$ acres. During the greater part of the year it is a concrete mass of carbonate-of-soda crystals. Mr. Pontez excavated to the depth of six feet without reaching the bottom of the deposit, which is constantly increasing from the influx from the larger lake. These lakes are situated about 65 miles from Rawlins Station, on the Union Pacific Railroad. The quality of the carbonate is declared to be fully equal to the imported article. Estimating the quantity by the specific gravity of the water, its depth and area, the large lake would yield on evaporation 78,000 tons, which would realize, at $45 per ton, 4,510,000. Besides the cost of freight, the expense of preparing the article for market would be $4 per ton for evaporating. The small lake already crystallized, and estimated only at a depth of six feet and an area of 155,000 feet, contains 30,660 tons, which at $45 per ton would realize $1,379,700.

Refraction of Sound.—Refraction of sound by the atmosphere was the subject of a paper read by Prof Osborne Reynolds, at the last meeting of the British Association, in which were given the results of experiments made by the author. He had confirmed his hypothesis that when sound proceeds in a direction contrary to that of the wind it is not destroyed or stopped by the wind, but that it is lifted; and that at sufficiently high elevations it could be heard at as great distances as in other directions, or as when there is no wind. An upward diminution of temperature had been proved by Glaisher's balloon-ascents, and he showed, by experiments with the sounds of firing of rockets and guns, that the upward variation of temperature had a great effect on the distance at which sounds could be heard. By other observations, he found that when the sky was cloudy and there was no dew, the sound could invariably be heard much farther with than against the wind, but that, when the sky was clear and there was a heavy dew, the sound could be heard as far against a light wind as with it.

The Opium-Habit.—The British vice-consul at Kinkiang, China, in a report to his government, states certain facts coming under his own observation, which seem to show that the opium-habit may exist without detriment to health. During a tour on the Upper Yang-tse-kiang, he was thrown into the closest relations with junk-sailors and others, almost every adult of whom smoked opium. Their work was of the hardest, rising at 4, and working, with hardly any intermission, till dark, having constantly to strip and plunge into the stream in all seasons. The quantity of food eaten by them was prodigious, and from this and their work it may be inferred that their constitution was robust. The two most addicted to the habit were the pilot and the cook. On the incessant watchfulness and steady nerve of the former the safety of the