Page:Popular Science Monthly Volume 38.djvu/592

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THE POPULAR SCIENCE MONTHLY.

The Appomattox formation of the Mississippi embayment described by W J McGee, which Prof. Stafford identifies with his La Grange formation in Tennessee, corresponds with an area extending from the coast along the Rappahannock River west to the Mississippi and north into Tennessee, which is covered with an interstratified sand and clay, susceptible to erosion and much affected by it. It is said that three fourths of the formation have been removed by erosion. The formation overlaps in irregular lines the Tertiary strata of Virginia. White kaolin, or feldspar clay, is often detected in it, and large quantities of white clay of commercial value have been uncovered in the northern part of Mississippi.

The Redonda phosphate, described by Prof. Hitchcock in the American Geological Society, is found in the volcanic island of Redonda, in the Caribbean Sea—an island with perpendicular walls five hundred feet high, which the visitor must scale with windlass and rope. The phosphates are found, nearly forty per cent pure, nearly devoid of lime, under a vast quantity of guano. They are not crystalline or fossiliferous, and occur in sheets between the layers of lava, or in pockets. The existence of this valuable substance at such a place has never been satisfactorily accounted for.

According to a paper by Prof. S. Coulter, Indiana, which is the fifth lumber-producing State in the Union, has one hundred and six species of trees, belonging to twenty-four orders. The most uniformly distributed tree is the sugar maple, which is found in every county. The author thought that geological formations had comparatively little effect in the distribution of forest trees in the limited area of the State, but that the chief influence came from the elevation of certain general sections and of particular localities, the courses of the streams, and the location of swamps. The forest area of the State has been reduced to 2,000,000 acres, about one tenth of the total area.

Prof. H. W. Henshaw, describing the Indian method of making maple sugar, maintained that the knowledge of the sugar and the process were aboriginal, dating from times unknown, and not in any degree derived from the white man. Indians collect the sap in bark vessels, which in some cases hold a hundred gallons. They take advantage of cold April nights to freeze the sap, and in the morning throw out the ice. They evaporate the sap by throwing hot stones into the reservoirs. They make sugar also from the silver maple and box elder, and, in Canada and Manitoba, from the birch tree. The sugar is eaten mixed with corn. Venison and rabbits are boiled in the hot sap during the process of evaporation. Sometimes pure sugar is the only diet of Indians for a month.

Mr. M. P. Mayo Collier disputes the conclusion accepted by many authors that "flat-foot" is due to a general want of tone in the fibrous structure of the body, and traces it by an elaborate physiological argument to overstrain of the ligaments and overpressure upon the os calcis, which may be produced by wearing high heels. For treatment of the malady he recommends good food, fresh air, and as much rest as possible, with a radical change in the construction of the boot. The toe and heel should change places; or a good laced boot should be worn, with the sole an inch thick in front and fining off to a line or two at the heel. By this means the normal inclination of the os calcis could be maintained, and the weight of the body properly disposed of.

According to Prof. F. V. Colville's summary, in the American Association, of the organization of the Botanical Division of the Department of Agriculture, the work is divided into two chief parts, the economical and the scientific; the latter includes some special investigations on forage plants in the Western arid lands. The authoritative position of the bureau gives it special facilities for making exchanges with other countries. The results of the work are published as bulletins and contributions from the scientific investigation. An immense amount of valuable material is being collected in the herbarium. A resolution was passed by the Association calling the attention of the department officers to the necessity of better protection for the collections against fire.

Prof. Joseph Moore reports that an entire skeleton of Casteroides ohioensis, or beaver of the days of the mastodon, has been found in Randolph County, Ind., a few miles east of Winchester. The bones indicated an entire length of the animal of five feet nine inches, and that its gnawing powers were commensurate with its size.

Prof. O. A. Derby explained to the American Association his method of separation, by means of the batea, or Brazilian miner's pan, of rare and heavy accessory elements in rocks. By this means certain minerals, regarded as extremely rare, have been shown to be common and widely spread. By his new method of search he had, on the day of his arrival there, found in rocks of New York State minerals never before found in those rocks in this country.

The Austrian Minister of Public Instruction reported some time ago that the evil of overpressure in the public schools was real and extended, and that its source was not so much in the course of study as in the method pursued. As remedies, he advised a better division of the holidays, and abolition or reduction of written exercises and of memorizing.