Page:Popular Science Monthly Volume 12.djvu/655

Rh present terminal moraine lies the former extension of it, constituting naked plains; and below the still more ancient moraine, showing the former size of the glacier, and comprised of a series of well-wooded hills. A muddy stream runs north from the end of the glacier.

Sensitiveness of the Leaves of the Common Teasel.—On closely examining the glandular hairs of the leaves of the common teasel, Mr. Francis Darwin observed protruding from them translucent, highly-refracting threads, capable of spontaneous movement. These filaments were found to consist of protoplasm, containing a large amount of resinous matter. They not only possess the power of spontaneous movement, but can also be made to contract violently under the influence of sundry reagents, of temperature, electricity, or simple mechanical irritation. In nutritive fluids the movements are very remarkable. Thus, in an infusion of meat, the filaments became rounded or sausage-shaped, or very long and bulky; sometimes they coalesced with one another, or again became completely detached and floated freely in the fluid. The movements resemble the "aggregation movements" observed in the tentacles of the Drosera. Mr. Darwin is of the opinion that these anomalous structures are connected both with the production of resin and the absorption of nitrogenous matter. In the adult teasel the leaves form, by their union in pairs across the stem, large cups, in which water collects, and in which insects are caught. The decomposing bodies of these insects form with the water a strongly-nutritive fluid, which is absorbed by the gland-hairs and their filaments.

Gas as a Domestic Fuel.—Gas as a fuel for domestic use possesses many noteworthy advantages over all other kinds of fuel, and there is, apparently, nothing to hinder its universal substitution in place of grosser fuels, save its greater cost. By using a gas apparatus, we may do away with dust, smoke, ashes, cinders, and kindling-material, save time and labor, and escape many vexations. For summer use, gas-stoves possess special advantages even on the ground of economy. "It is desirable," says the American Gaslight Journal, "to keep as cool during the heated term as is consistent with the pecuniary and mechanical means at our command; therefore, we should have our artificial heat so arranged as to be used only when desired for active work, and employed no longer than is necessary. With a good apparatus, the gas actually used for cooking and performing all necessary fuel-labor, during the warm season, costs no more than the coal and kindling used for the same purposes, and we get the comfort, saving of time, convenience, and sanitary influence, thrown gratuitously into the trade." The case is different when it is proposed to employ gas for the purpose of warming houses. "It is," the Journal admits, "more expensive to run a gas-stove for a given amount of heat than it is to run a coal-stove for the same. Hence, when the heat is to be continuous, the coal-stove has the advantage so far as cost is concerned." Our contemporary then suggests to the gas companies the advisability of setting up in houses of gas-consumers a special metre connected with the heating and cooking apparatus, and of selling gas for these purposes at half-price, so as to encourage the use of gas in this way.

Impure Water fatal to Fish-Breeding.—Mr. Seth Green takes advantage of an accident which occurred lately at the State fish-ponds, to caution people against drawing off the water of old mill-ponds, except they do it very slowly, especially in warm weather. "Last week," he writes to Forest and Stream, "the State ponds at Caledonia came near losing all their breeding-fish. The head of the stream is about one mile above the ponds. Half of the water comes out of the ground at the head of the stream, and a dam was put across the creek sixty years ago, about forty rods from the spring, making a pond of several acres. It is full of moss and all sorts of animalcula. Last week the owner of the pond opened the gates, and let the water down with a rush. It killed all the trout in the stream for a half-mile below, and if it had not been for many large springs coming in on both sides of the creek, all the trout in the stream and ponds would have been killed, and it would take many years to restock the ponds as