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286 somewhat tedious, but the results fully repay the worker. By means of these methods steel has been found to contain five main constituents: Pure iron, ferrite; carbide of iron, cementite; sorbite, of uncertain composition; martensite and froostite; the latter marks the transition of soft iron into hardened steel. Sorbite, froostite, and martensite appear to be solidified solutions of various forms of carbon in divers forms of iron, for it seems clear that metallographic work on steel brings into prominence the existence of allotropic forms of iron. An exhaustive monograph on the progress of micro-metallography during the past ten years, by M. F. Osmond, may be found in the Bulletin de la Société d'Encouragement, vol. x, p. 480, 1895.

Audibility of Fog-horn Signals.—Some time ago there appeared a description of some experiments which went to prove that around each siren there is a zone, about one and a half nautical miles broad, within which fog signals can not be heard, although they are distinctly heard outside that zone. These statements have been recently confirmed by a series of experiments which are noted in Nature. In one of these the vessel steamed with the wind straight toward the lightship from a distance of four and a half nautical miles. At a distance of two miles and three quarters the sound became faintly audible, and suddenly increased in loudness at two miles and a half, retaining the same intensity up to two miles distance. From one and three quarters to one and a half mile the note was scarcely audible, but then it immediately increased to such an extent that it appeared to originate in the immediate neighborhood of the vessel. The steamer at this point reversed its course, and the fluctuation over this part of the course was found to be the same, except that it was even more strongly marked. The vessel was again reversed, and at half a mile the sound disappeared entirely, to reappear at a quarter of a mile from the lightship; after which it gradually and steadily increased in intensity until the latter was reached.

The Ideals of Modern Medicine.—We take the following from President Sir T. Russell Reynolds's address before the recent meeting of the British Medical Association in London: "The outcome of what I have been saying is this: that the scattered fragments of knowledge and guesses at truth of many years have been gathered into a focus during the past twenty-five years; that the vegetable life extracting from the mineral world the materials it needs for growth and production of powerful agencies for good in the form of food and medicines, and for evil in the form of poisons, has given itself up to the growth of animal life, with its much more complex organs, and for cure of ills once thought beyond the reach of human aid; but that, thanks to man's scientific ardor and industry, it has again shown itself to be our servant, our helper, and our protector. These are not dreams of the study, they are facts of the laboratory and of daily life; and in using that word 'life' again, I must endeavor to emphasize still more forcibly upon you my urgent belief that it is to living agencies and their employment that we must look for help in the care of infancy, the conduct of education—moral, mental, and physical—the training up of character, as well as of limbs; that it is the guidance of living functions, in the choice of living occupations, be they either of hard work or of amusement. It is to these we must appeal if we would see the mens sana in corpore sano; and then it will be to these that we may confidently look for help, when the inroads of age or of disease are at hand, often to cure us of our trouble; or if not, to give us rest and peace."

City Government.—The corporation of the city of London is one of the most ancient bodies in England, and its record shows a constant succession of capable men and a uniform policy. It was in existence before Parliament, and it has seen the downfall of more than one royal house. The secret of its success has lain in the fact that municipal dignity has always been confided to the hands of men of business, who had shown their capacity to manage private affairs of great magnitude before they were intrusted with those of their neighbors. Their training had been such as to remove them as far from the hide-bound conservatism of the official as from the destructive reforming energy of the professional politician. As an instance of the methods employed may be