Page:Popular Science Monthly Volume 26.djvu/883

Rh good manners and language, cleanliness and neatness, cheerful obedience to duty, consideration and respect for others, honor and truthfulness in word and act; and not only that regard had been paid in classifying them as to their health, age, and mental capacity, but that the dull and delicate had not been at any time within the preceding year unduly pressed. And all this in five hours for three hundred children! Miss Lupton adds instances of actual and serious over-pressure which had come under her own observation.



true source of the Mississippi River has been determined, as he claims, by Captain Willard Glazier, who led an expedition in search of it in 1881, to be a lake a few miles south of Itasca Lake, and not less than three feet above it, in latitude 47° 13' 25". Captain Glazier's party proceeded in canoes via Leech Lake to Lake Itasca, and, accompanied by an old Indian guide, pushed down to the new lake, which is of considerable size, and is named after the discoverer, Lake Glazier. It is 1,578 feet above the Atlantic Ocean. The length of the Mississippi, calculated to it, is 3,184 miles. The lake has remained in obscurity so long on account of the wild condition of the country, and because it is out of the usual route of the fur-trade.

very satisfactory experiments in the purification by artificial aëration of the water supplied the city have been reported to the Franklin Institute, Philadelphia. On comparison with the ordinary supply, the percentage of oxygen in the aërated water was seventeen greater than before; the amount of carbonic acid was fifty-three per cent; and of total dissolved gases, sixteen per cent more. "The percentage of free oxygen," says the report, "represents the excess over and above what was required to effect the oxidation of the dissolved impurities."

who has had much experience in Egypt and Asia Minor, regards the difference between a dromedary and a camel as largely a matter of speed. The former bears about the same relation to the latter as the trotting-horse to the cart-horse. The dromedary is credited with trotting about twenty miles an hour, while a regular camel or burden-bearer can not be forced more than some four or five miles an hour. The Egyptian camel and the dromedary have one hump. Dr. Anthony never saw a "Bactrian" or two-humped camel till he was east of the Crimea.

of Breslau, has published some interesting observations made by the naturalist Leeuwenhoek on microscopic organisms in the cleanings of his teeth in 1683, or more than two hundred years ago. The observer distinguished several kinds of organisms, and described them so precisely that they would be easily recognizable. One resembled a rod—the bacillus; others, bending in curves, the bacteria; a third kind, creeping in snake-fashion, a vibrio; another kind, extremely minute, and resembling a swarm of flies rolled up in a ball, was evidently the micrococcus. Leeuwenhoek marveled that these things could live in his mouth. Two remarkable circumstances about this story are, that Leeuwenhoek used the imperfect instruments of his time with wonderful skill, and that so long a time elapsed before any progress was made in the study of bacteriology.

29 Cathedral Street, Baltimore, has issued a prospectus for the "American Journal of Archæology," to be published quarterly and devoted to the study of the whole field of archæology, Oriental, classical, early Christian, mediæval, and American, and to serve as the official organ of the Archæological Institute of America. It will be illustrated. Professor Frothingham will be assisted by Professor C. L. Norton, of Harvard College, as advisory editor, and by Dr. A. Emerson, Mr. T. W. Ludlam, Professor Allen Marquand, Mr. A. R. Marsh, and Mr. C. C. Perkins, as special editors. The subscription price will be three dollars and fifty cents a year. In addition, subscriptions are invited from the friends of archæological studies for the formation of a reserve fund to meet the deficit which must occur during the first few years of the "Journal's" existence.

to the statements of Professor Poleck, of Breslau, the "house-fungus" (Merulius lacrymans), which has recently become so extensively spread in Europe, is most destructive to wood that contains most mineral matter. The richer the wood in phosphates and potash compounds the more does the fungus flourish. Now, pine-wood felled in the sap contains five times as much potash and eight times as much phosphoric acid as wood felled in the winter. Hence, it is better, for the preservation of the wood, to cut the trees late in the winter season.

reports that having obtained more considerable quantities of different liquefied gases, he caused liquid nitrogen to boil under a pressure of sixty millimetres at -214° C. (-353° Fahr.), when it became partly solidified. At the pressure of four millimetres, the ebullition, which took place at 225° C. (-363° Fahr.), determined the complete solidification of the 