Scientific Serials

Abstract

American Journal of Science, September.—Notes on the geology of Florida, by William H. Dall. In this paper the results are given of two excursions to Southern and Central Florida undertaken in 1885 and 1887 by instruction of the Director of the United States Geological Survey. Special attention is devoted to the process of contemporaneous rock-formation now going on along the Gulf shores of West Florida, and to the Tertiary rocks which prevail so largely throughout the Peninsula. No coral or coral-reef formation was anywhere observed, and it is evident from these further researches that the hypothesis of Agassiz regarding the geological origin of this region can no longer be maintained.—Notes on the deposition of scorodite from arsenical waters in the Yellowstone National Park, by Arnold Hague. The occurrence of this comparatively rare mineral as a deposition from thermal mineral springs is here noticed for the first time. It is found in several localities in the Yellowstone Park as an incrustation deposited from the waters of several hot springs and geysers, and is especially abundant at the Joseph's Coat Springs on Broad Creek, east of the Grand Cañon. The analysis—yielding Fe2O3 34.94, As2O5 48.79, and H2O 16.27—shows this mineral to be true scorodite, a hydrous arsenate of iron, the layers varying from a mere coating to an eighth of an inch in thickness. Wherever observed it occurs as an amorphous deposit, and when pure, leek green in colour.—The effects of magnetization on the viscosity and the rigidity of iron and steel, by C. Barus. An attempt is made in this memoir to verify by a static method the results recently communicated by Mr. Herbert Tomlinson on the changes of viscosity and of elasticity produced by magnetizing iron. It is shown that the increment of rigidity due to magnetization increases at an accelerated rate as the soft, temporarily twisted wire becomes more nearly filamentary, A series of results is also given on the rigidity of magnetized steel temporarily strained and varying in temper from extreme hard to extreme soft. A main object of the paper is to show how the principles here established may be utilized for the construction of electric dynamometers.—Fauna of the “Upper Taconic” of Emmons, in Washington County, New York, by Charles D. Walcott. This paper deals specially with the fauna represented by Atops trilineatus and Elliptocephala asaphoides from the black Taconic slate near Bald Mountain, Washington County, as described by Dr. Emmons in his second memoir on the “Taconic System.” The paper is accompanied by a plate illustrating nineteen specimens of this fauna.—On the amount of moisture remaining in a gas after drying by phosphorus pentoxide, by Edward W. Morley. This quantity is here determined by the method applied in the case of sulphuric acid, the process consisting in drying the gas with phosphorus pentoxide and then passing it through a weighed apparatus in which the gas is first slightly moistened, then much expanded, and lastly again dried by phosphorus pentoxide.—Is there a Huron group? by R. D. Irving. In this paper the author inquires whether there can be carved off from the upper part of the great complex of rocks ordinarily known as Archæan, a Huronian series, entitled to rank with such groups as the Cambrian, Siberian, &c. In this first part of the memoir it is shown that the series on the north shore of Lake Huron mapped by Logan on Plate iii. of the atlas to the geology of Canada (1863) is entitled to rank as a separate group by its intrinsic characters and its structural distinction from the older Archaean and younger Cambrian and pre-Cambrian rocks of that region.