average death-rate per one thousand persons has been reduced nearly eleven per cent, in twelve years, under the operation of the sanitary measures instituted by them, which included the demolition of unwholesome dwellings, and the provision of ample hospital space for smallpox and fever cases, and for the control and limitation of epidemic disease. They also cite from the report of the Registrar-General figures showing that a similar improvement in sanitary condition has been wrought in other towns: in Edinburgh of fourteen, in Dundee of twelve, in Aberdeen (where the death-rate was already very low) of three and one-half per cent. The figures given of a number of English towns show a less striking rate of improvement. Dividing the twelve years into two groups of six years each, it is found that, in twelve leading towns, 61,000 fewer deaths occurred in the second six years (1873-'78) than would have occurred under the higher death-rates of 1867-'72. The sanitary officer of Manchester has reported to the bishop of the diocese that, under the operation of the measures which have been adopted in that city, "typhus and typhoid fever, though not absolutely extinguished, are of comparatively rare occurrence, and nearly all other infectious diseases have been largely reduced in amount, while the general health has been improved."
An Antarctic Expedition.—The Italian Geographical Society has projected an Antarctic exploring expedition, to be under the command of Lieutenant Beve, an Italian officer who was with Nordenskjöld during his last expedition. Very little is definitely known concerning the Antarctic regions, and they offer numerous problems to be solved. They have been touched upon, but can hardly be said to have been explored, by several navigators since Captain Cook crossed the Antarctic Circle in 1774-'75, including Lieutenant Wilkes with the American Expedition, but the results of the observations made upon them do not agree. Even the Challenger Expedition, in 1873, added but little to our knowledge of them. It is still not fully settled whether the region be only an immense mass of water or whether it contains another continent. Lieutenant Wilkes believed that he had established the existence of a continent, but Sir James Ross a year later sailed over two of the positions assigned by him to the continent, while he found the extensive Victoria Land with mountains 14,000 feet high and an active volcano. The great ice-sheet, which certainly covers the land, needs to be studied and compared with the ice-sheet of Greenland. Lieutenant Beve and his companions hope to winter in the Antarctic region, and to be more successful in studying its character than their predecessors have been.
A Holtz frictional electric machine, said to be the largest ever made in this country, has recently been constructed by a well-known firm manufacturing physical and chemical apparatus in this city. The revolving glass disk is forty and the condensing stationary disk forty-six inches in diameter. It is provided with the continuous charging apparatus of Van Brunt, which is a very considerable improvement over the ordinary means of charging by rubbing a disk of vulcanite with a skin by hand. The machine gives a discharge over twenty inches long, and, on account of the facility of charging, can be satisfactorily worked in almost any weather.
At a late meeting of the California Academy of Sciences, Mr. W. N. Lockington read a paper on fishes, in which he states that of three hundred and eight species, mostly marine, occurring on the Pacific coast, all but thirty-seven are found in California. Of the five hundred and forty fresh-water species known in the United States, but thirty-seven are found in that State.
That ants can make themselves heard as well as felt, is asserted by Mr. S. E. Peal, who writes to "Nature" that he has observed in several varieties of this insect the power of producing distinctly audible sounds. Two kinds of ants, one brown the other black in color, could be heard a distance of twenty or thirty feet, the noise being produced by scraping the horny apex of the abdomen three times in rapid succession against the dry leaves of the nest.
Dr. Ephraim Cutter describes in the October number of the "American Monthly Microscopical Journal" an interesting study he has lately made of the central surface-waters of several ponds and lakes in Massachusetts. He found, contrary to the general opinion, that the waters in the middle of ponds or lakes contain large numbers of mi-
