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THE POPULAR SCIENCE MONTHLY.

case, and wire gauze in the other, the heat which is being taken out with it; so that the cold air inspired shall be raised in temperature before it reaches the lungs, and thereby conduce to a conservation of the bodily heat. Some interesting considerations bear on this. Animals provided with bushy tails seem to be so as a matter of correlation of growth, their bodies being always provided with thickly-set and more or less soft fur. "I cannot," says Mr. Tait, "find an animal with a bushy tail which cannot, and does not, lie curled up when asleep. I went round the Zoölogical Gardens at Dublin on a very cold morning in February, and found the civet cat, and some other bushy-tailed animals, coiled up with their noses buried in the fur of their tails.

"In the squirrel this use of the tail is very marked, and in birds the same object is accomplished by their burying their heads in the down of the shoulders. Animals provided with bushy tails are all solitary in their method of living, so far as I can find; and, therefore, an essential for their survival is some method by which variations of temperature shall be resisted. The use of the tail for this purpose is, I think, best of all illustrated in the great ant-eater (Myrmecophaga jubata), in which the hairs of the tail reach a very great size, and cover up the animal when reposing, so that he looks like a bundle of dried grass. It may also serve as a protection by mimicry in this case. Mr. Wallace states also that this animal uses its tail as an umbrella in a shower, and that the Indians divert its attention from themselves by rustling the leaves in imitation of a falling shower, and while he is putting up his umbrella they kill him. Of the quadrumana, the marmosets afford a striking instance of a bushy tail as a probable provision for protecting these delicate creatures from depressions of the temperature."

 

Remedy for Boiler Incrustations.—"Apparatine" is the name given to a substance said to be effectual in preventing incrustation in boilers, and also useful wherever gelatine and gelatine-like substances are required, as in sizing textile fabrics. It is a colorless, transparent material, obtained by treating any amylaceous substance with a caustic alkali. It is best made, however, with potato-starch, treated with a lye of caustic potash or soda. The best method of preparing the apparatine is as follows: 16 parts of potato-starch are put into 76 parts of water, and kept in a state of suspension by stirring; then 8 parts of potash or soda-lye at 25° Baumé are added, and the whole thoroughly mixed. In a few seconds the mixture suddenly clears, forming a thick jelly, which must be beaten up vigorously. It is now a colorless, transparent substance, slightly alkaline in taste, but odorless, and of a stringy, glue-like consistency. Exposed to the air, it dries slowly, but without decomposing; and even when heated to dryness, although it thickens and swells, it continues unchanged, as when air-dried.

To prevent incrustation, the apparatine may be placed in the boiler or added to the feed-water in the tank; but the best results have been obtained by placing it directly in the boiler. Applied to silk, woolen, and cotton goods, it gives them a smoothness hitherto unattainable. When once, applied to the goods, and become dry, it appears to be virtually insoluble. Diaphanous or coarsely-woven fabrics, when dressed with apparatine, are rendered stiff and rigid. It may be used as a thickening in calico-printing.

 


NOTES.

A correspondent of the Scientific American states that in Minneapolis a supply of water for extinguishing fires is obtained in localities beyond the reach of the city water-works by sinking four drive-wells at distances thirty feet apart, or fifteen feet from a centre. The pipes (2 1/2 inches) of the four wells are brought together at the top, where the suction-hose of the fire-engine is attached. On trial an engine threw a continuous stream from a 1-1/8 inch nozzle for one hour. The water in the tubes was then at the same height as at the beginning.

The chaparral-hen is described by a sportsman in Texas as a very pretty bird. The female lays one egg, and then commences sitting. While sitting she lays four more, the first being the largest and the fifth the smallest. The birds, when grown, seem to be of the same size. By the time the fifth egg is hatched the first is nearly a full-fledged bird. The first egg is about the size of a pheasant's; the others range in size between the pheasant's and the quail's egg.