Page:Popular Science Monthly Volume 45.djvu/156

 the usual quantity of calcium sulphate in solution passes through the vegetable tissues of the plant and sets up a series of chemical changes resulting in the formation of carbonate of lime and iron pyrites.

is declared a disease, and its pathology is studied, in the Medical Record. It is found an almost constant indication in albuminuria and diabetes. Malarial fevers induce it, and it is a frequent effect of dyspepsias and indigestions. It is a characteristic in neurasthenia so generally that it is usually safe to say that an indolent person is neurasthenic to a certain extent. Hence, in cases of chronic indolence, the counsels of a physician are often more in place than those of a moralist.

has been observed that some of the batrachians have a preference for one or the other of the mediums in which they are capable of existing—the triton, for instance, and the salamander for air, while the frog chooses either, according to the atmospheric conditions, although their morphology points to a descent from a common stock. The subject has been studied by M. Dissart, who, finding that aquatic species transpire more and respire less than land species, concludes that an antagonism exists between the two functions by the operation of which the habitat is determined. If an aquatic species is placed in air, its transpiration is augmented, and it returns to the water to counteract the increase; while if an air species is kept in water, its respiration diminishes and it is obliged to return to the air in order to prevent asphyxia.

telephotos is the name of a new method of electric signaling by night and day, invented by C. V. Boughton, of Buffalo, N. Y. The theory of it is the production by electricity upon a shaft of incandescent lamps of the symbols of the Morse alphabet and numerals, in dashes five feet long, made with ten lighted lamps, and dots three inches long each, made with one lighted lamp, with unlighted intervals of five feet between each, which would bring under the eye the complete symbol at once. It is intended for use at any points within vision between which the laying of telegraph wires is impossible or impracticable.

United States Commission of Fish and Fisheries is engaged in an inquiry, under the direction of George F. Kunz, concerning the locations, yield, and proper protection of fresh-water pearl fisheries in the United States, and in connection with it has sent out a list of questions embracing the subjects of the nature of the stream in which the pearl-bearing mussels are found, kind of bottom, character of water; geological character of the district as to rock, soil, etc.; general abundance of mussels; size, shape, and position of the mussel beds; local names of mussels; habits of mussels; enemies and fatalities to which mussels are exposed; nature and extent of destruction by muskrats, hogs, freshets, etc.; size, shape, and color of mussels; species of mussels in which pearls are most common; proportion of mussels in which pearls occur; sizes or other peculiarities of shells in which pearls are found; nature and origin of pearls; position in mussels; size, shape, and color of pearls; and relative value of pearls of different sizes, shapes, and colors. Other questions relate to the markets and prices for pearls, the method, history, and statistics of the fisheries, the uses made of the mussels after the pearls are taken out, and the exhaustion and replenishment of mussel beds.

exceedingly full and rich herbarium and botanical library has been given by Captain John Donnell Smith, of Baltimore, to Johns Hopkins University, on condition that a suitable building be provided for it. The flowering and lower plants of the whole world are represented in the herbarium, which includes Kerner's collection of Austro-Hungarian plants, about thirty individual collections of North American plants, more than a dozen of Central American and Mexican, Lebmann's and nine other collections of South American plants, and representatives from Egypt, Abyssinia, and other parts of the world.

palms are said to be the plants possessing the largest leaves. The Quaja palm of the Amazons has leaves approaching fifty feet in length by sixteen feet in breadth. The leaves of some palms in Ceylon are more than eighteen feet long and nearly as wide, and are used by the natives for making tents. The cocoa palm has leaves nearly thirty feet long. In other families than the palms, the parasol magnolia of Ceylon forms leaves large enough to shelter fifteen or twenty persons. One of these leaves, carried to England as a specimen, measured nearly thirty-five feet. The largest leaves grown in temperate climates are those of the exotic Victoria regia, which sometimes reach about seven feet in diameter.

grape culturists are now making a very nice illuminating oil from grape seeds, from which they get a product of from ten to fifteen per cent. It is clear, colorless, and inodorous, and burns without smoke.



of Harvard University, died in Eastern Siberia in August, 1893, while on a journey of exploration and ethnological research. He left a Gilyuk village, near the mouth of the Amur River, for a sail in an open boat on the 11th, and his body was found two weeks afterward on the coast of Sakhalin. 