Page:Popular Science Monthly Volume 8.djvu/393

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The Frailty of Modern Art.—The old masters made their own colors. The material which entered into their pigments came to them unadulterated, and the excellence of the paint depended on the brain mixed in it. Hence, their paintings to-day, though lacking somewhat freshness of color, have a mellowness which age can only give to pigments of the highest excellence. Modern pictures will not ripen, their colors fade, and the mellowness of the old masters is unattainable. Holman Hunt, of England, has called the attention of lovers of the fine arts to this deplorable fact. And the reasons are given. The artist's colors are no longer made by himself. Their manufacture is a business from whose secrets he is shut out. Artist's colors are subject to fearful adulteration. Even the oils cannot be genuine, as things go. The materials of which they are made go to the maker in a sophisticated state. Linseed and poppy-seed are adulterated before they reach the oil-maker's hands. So too, is it generally with the crude material for the pigments. A high-priced vermilion from an eminent dealer, upon analysis, yielded twelve per cent, of red lead. So the artist, who puts his whole life and soul into a painting that should be "a joy forever," has this immortality of art quenched by the use of dishonest paint.

Oscillations of Lakes.—The "seiches" of the lake of Geneva have for several years, as we learn from Nature been under investigation by Forel, of Lausanne. The term "seiche" is applied locally to certain oscillatory movements occasionally seen on the surface of the lake. The phenomenon had been investigated by previous observers, among them Saussure and Yaucher, who attributed it to variations in atmospheric pressure; in this, Forel agrees with them. The same phenomenon occurs in other Swiss lakes, and Forel believes it will be found in all large bodies of water. He recognizes in the "seiche" probably the most considerable and the grandest oscillatory movement which can be studied on the surface of the globe. His investigations have led him to the conclusion that the "seiche" on the Swiss lakes is an oscillatory undulation, having a true rhythm, and that the phenomenon is not occasional, but constant, though varying in degree. The duration of a "seiche" is a function of the length and depth of the section of the lake, along which it oscillates; this duration increases directly with the length, and inversely with the depth of the lake. The instrument he has devised for the investigation of the phenomenon he calls a plémyramàtre ("tide-measurer").

Contents of a Kitchen-Midden.—Prof. Cope lately exhibited to the Academy of Natural Sciences of Philadelphia a collection of animal remains, fragments of pottery, flint arrow-heads, etc., taken from an Indian kitchen-midden in Charles County, Md. The animal remains included the bones of seventeen species of vertebrata and two of shells. Of the vertebrates four were mammals, two birds, four reptiles, and seven fishes. The mammals were the Virginia deer, raccoon, gray squirrel, and opossum. Most of the deer-bones had been split into pieces lengthwise for the purpose of extracting the marrow. The birds were represented by a number of parts of the turkey, and the tarsometa-tarsus of some natatorial bird of the size of a widgeon. The reptiles were all turtles, and included the snapper, the box-tortoise, and two emydes. The fishes represented were the sturgeon and the gar, there were also numerous bones of Siluroid fishes of at least two species. The mollusks were Unio purpureus and Mesodon albolabris.

Habits of Blind Crawfish from Mammoth Cave.—In November, 1874, Prof F. W. Putnam collected a number of blind crawfish (Cambarus pellucidus) in the Mammoth Cave, which he kept alive for several months afterward in Massachusetts. The habits of these animals and the reproduction in them of lost parts are the subject of a communication by Prof. Putnam, published in the "Proceedings of the Boston Society of Natural History." The animals eat but very little in captivity. When food is dropped into the jar in which they are kept, they dart backward, then extend the antennæ, and stand as if on the alert. The animal continues in this attitude for several min-