Page:Popular Science Monthly Volume 19.djvu/884

864  sea, to which a few Mediterranean forms have since been added. The fauna of the Caspian is analogous to that of the Black Sea, but without the Mediterranean species. Since this sea is composed of brackish water, and is fresh in the northern part, it can contain only those species which live in brackish water or are indifferent or migratory, with no real sea-fishes. The ichthyology of the Sea of Aral has only recently been determined. It is entirely of a fresh-water character.



has published at Cambridge, Massachusetts, the results of a microscopical study of the iron-ore, or peridotite, of Iron-Mine Hill, Cumberland, Rhode Island, a valuable ore similar to the ore of Tagberg, Sweden, of which an immense quantity occurs in mass. He also, in the same pamphlet, describes a gold-mine, which is worked for its gold, in the quartz veins of the diabase of Sullivan, Hancock County, Maine.

apiarian, of London, has made a successful shipment of queen humble-bees to New Zealand. Of eighteen bees which were sent on the 7th of December last, two were alive and strong when the lot reached the consignee on the 3d of February, and flew at once against the wind into the clover-fields. These are the first humble-bees that have ever lived in New Zealand, all former attempts to ship and acclimatize the insects having failed.

is on foot in England, and is receiving the countenance and support of members of Parliament, to reduce the time of labor of railway employees to nine hours a day. In behalf of the change it is urged that the duties of the men, and especially those performed by the engineers and signal-men, are of a nature to require the keenest and most unflagging attention, and that this can not be given for many hours continuously without great fatigue, and a consequent diminution of the alertness and care necessary to the safety of life and property.

other nations of Europe, and the United States, have established stations around the north polo for the study of terrestrial magnetism, France is about to establish one among the islands of Cape Horn. Credits for this purpose are to be asked of the Chambers, and it is anticipated that the expedition will go out in the same vessel that carries the astronomers deputed to observe the transit of Venus.

who was appointed a committee of the New York Academy of Sciences on the subject of procuring the adoption of a uniform system of mathematical notation, or symbolization, has reported that uniformity would be very desirable, but hard to gain. It prevails essentially in pure mathematics, where the algebraic signs and the symbols of calculus are everywhere the same, but not in applied mathematics, where even the most common symbols are employed without discrimination, and according to each writer's whim and convenience. The realization of uniformity would be almost equivalent to the reconstruction of a language, and would require continued efforts and discussions. The most that the Academy can accomplish toward it at present is to take a position in favor of it.

fifty-fourth meeting of the German Association of Naturalists and Physicians will be held in Salzburg, September 18th to 24th. Addresses will be delivered at the general meetings by Dr. von Pettenkofer, on the soil and its connection with the health of man; by Dr. von Oppolzer, of Vienna, on the sufficiency of Newton's law of gravitation to explain the motion of the heavenly bodies; and by Herr Mach, of Prague, on natural-history teaching.

death of the eminent German botanist. Professor M. J. Schleiden, is announced. Professor Schleiden was born at Hamburg in 1804, and turned his attention to botany after having studied law. He was Professor of Botany at Jena from 1839 to 1862, and of Vegetable Chemistry and Anthropology at Dorpat in 1863 and 1864. His principal work is "Die Grimdzüge der wissenschaftlichen Botanik" ("The Principles of Scientific Botany").

has reported the complete success of the experiments which he has been carrying on on a large scale at a farm near Melun, France, in vaccination against carbonaceous diseases; and he believes that he has obtained a process by means of which sheep and cattle can be made wholly secure against this most dangerous and destructive class of maladies.

report of Professor Abel on colliery explosions confirms the theory that coal-dust is an important factor in them. A mixture of coal-dust and air is not explosive, but if a quantity of fire-damp, which, mixed merely with air, would be harmless, is also present, a highly explosive atmosphere is produced. Professor Abel's experiments show that any kind of dust mixed with air, containing a small quantity of fire-damp, converts the mixture into an explosive compound. 