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THE POPULAR SCIENCE MONTHLY.

Cayuga ducks. While the birds were still very young, many of them disappeared, and the bodies of several were found with the brains picked out. On watching carefully, a red-headed woodpecker was caught in the act. He killed the tender duckling with a single blow on the head, and then picked out and ate the brains.

The "Transactions" of the American Society of Civil Engineers for May contains an article on "Approximate Determination of Stresses in the Eye-Bar Head," by W. H. Burr; minutes of meetings; an interesting letter written by General Philip Schuyler in 1799, giving his opinion of a plan proposed by Dr. Brown for supplying this city with water from the Bronx River; and a list of new books on engineering and technology, besides other matters of interest to engineers.

Mr. McNab, of the Edinburgh Botanical Society, states that the past spring in Scotland was more backward than any other during the last twenty-eight years.

Having measured the red blood-corpuscles of men belonging to fourteen different races or nationalities, Dr. Richardson, of Philadelphia, found the average diameter to be 13224 of an inch, the maximum diameter being 12777, and the minimum 14000

The "hard glass" manufactured by Siemens, of Dresden, by means of hydraulic pressure, is said to be stronger than Bastie's glass, in the proportion of five to three. Its fracture, according to the English Mechanic, is fibrous, not crystalline. Besides being stronger, it is also cheaper than Bastie's "tempered" glass; and, unlike the latter, sheets of the Dresden glass can be cut to any size with the diamond.

The number of blind persons per 100,000 of the population of Bavaria is 52; of the United States, 52; Prussia, 58; Belgium, 66; Switzerland, 77; Sweden, 81; France, 84; Norway, 184. The number of insane, cretins, and idiots, is, in Bavaria, 110 per 100,000; in the United States, 160; Scotland, 185; France, 238; Switzerland, 300; Würtemberg, 312; Norway, 340. Of deaf mutes the United States have 45 per 100,000; Belgium, 46; Bavaria, 58; France, 58; Saxony, 60; Switzerland, 245.

Trade, commerce, is usually considered one of the chief influences favoring civilization; yet, according to Mr. James Irvine, it has the contrary effect in Africa. Every native is a trader from the day of his birth, and the cultivation of the soil is utterly neglected. The buying and selling of pal moil, palm-kernels, and a few minor products, give them really all they require, and they cannot be stimulated to further exertion.

Langeroy, in a communication to the Paris Academy of Sciences, calls attention to the antiseptic properties of bichromate of potassa. According to him, one per cent, of the bichromate in water absolutely prevents putrefaction in all animal and vegetable substances. After meat has stood in the solution for a few months it resembles gutta-percha, and medals have been struck from it; but it becomes poisonous, and even dogs refuse to eat it. This antiseptic will doubtless be of great use for the preservation of natural-history specimens.

A simple and ingenious contrivance for drawing liquids from carboys is described in La Nature. It consists of two tubes passing into the carboy through the stopper, one of the tubes serving as a siphon, and the other as a means of increasing the air-pressure over the liquid. At its outer extremity the siphon has attached to it a short section of rubber or gutta-percha tube, which may be compressed by a clamp. To fill the siphon, a person blows through the short tube, with the clamp relaxed. When sufficient liquid is drawn off, the clamp is allowed to compress the walls of the elastic tube, stopping the flow.

In a late report on the origin of the skin-disease known as Delhi boil, or, as it has been lately named from its wide distribution in the East, Oriental sore, Drs. Lewis and Cunningham reject the view that the affection is attributable to parasitic agency. From extended observations in widely-separated districts they are led to ascribe the disease to the use of well-waters that contain a large quantity of salts, and are extremely hard. In Egypt, Asia Minor, and Syria, where the sore prevails, the well-waters are notoriously brackish, agreeing in this with many stations in India, where the disease is also prevalent.

Dr. C. A. Bressa, deceased in 1835, bequeathed all his property to the Turin Academy of Sciences, the net interest to be given every two years as a prize for the best work done, during the previous four years, in physics, natural history, chemistry, physiology, pathology, geology, history, geography, or statistics. The fund is now available, and the first award will be made two years hence. The competition will be open to the whole world, and the prize will amount to about $2,500.

Moles render to the farmer and gardener very considerable service at little or no cost—the damage they do being more than compensated by the destruction of worms and grubs. When they have eaten all the grubs and worms in a certain place, they emigrate to another, and there repeat their gratuitous work.