Page:Popular Science Monthly Volume 44.djvu/731

Rh only on or near to the surface of the earth. Without mechanical aids he could walk for several hours at a speed which was ordinarily from three to four miles per hour. Under exceptional circumstances he had accomplished over eight miles in one hour, and an average of two and three quarter miles per hour for a hundred and forty-one hours. In running he had covered about eleven and a half miles in an hour. The power of the living human mechanism to withstand widely diverse and excessive strains was altogether unapproachable in artificial constructions. Thus, although fitted for an external atmospheric pressure of about fifteen pounds per square inch, he had been able, as exemplified by Messrs. Glaisher and Cox well in 1862, to ascend to a height of seven miles and breathe air at a pressure of only three and a half pounds per square inch, and still live. And, on the other hand, divers had been down eighty feet deep, entailing an extra pressure of about thirty-six pounds per square inch, and had returned safely. One had even been to a depth of one hundred and fifty feet, but the resulting pressure of sixty-seven pounds per square inch cost him his life. No animal burrowed downward into the earth to a greater depth than eight feet, and then only in dry ground.

The Phillips Prize Essay Fund.—The Herbert M. Phillips prize essay fund of five thousand dollars of the American Philosophical Society was founded by Miss Emily Phillips in memory of her deceased brother, who was an honored member of the society. Its purpose is the provision of prizes, to be awarded from time to time from the income of the fund, for the best essay of real merit on the science and philosophy of Jurisprudence. In pursuance of the conditions of its establishment, a prize is now offered by the society, to be awarded during 1895, of five hundred dollars lawful gold coin for the best essay on either of the following subjects: 1. The sources, formation, and development of what is generally designated the common law of England. 2. The theory of the state, treated historically, and upon principle, with a discussion of the various schools of classical, mediæval, and modern thought upon the subject. 3. The historical and doctrinal relations of the Roman law and the English law, illustrated by parallels and contrasts. The essays of, competitors should be in possession of the society before the first day of January, 1895, and should be sent addressed to Frederick Fraley, president of the society.

Oxygen as a Remedy for Choke Damp.—A committee appointed at the Edinburgh meeting of the British Association, 1892, to determine whether oxygen gas was useful as a restorative in cases of carbonic-acid poisoning, and particularly in those of choke-damp asphyxia in mines, reported to the recent meeting its conclusions, from experiments on rabbits, that oxygen was of no greater service than air. It suggested, however, that the experiment of keeping a few cylinders of air with nose and mouth pieces ready for use in those parts of the workings where men could be most easily imprisoned might be attended with valuable results. It seemed quite reasonable that where a person had to be dragged long distances through a contaminated atmosphere the chances of ultimate recovery would be greater if the effects of this poisonous atmosphere were neutralized at the commencement and during the progress of the work of rescue than if no such attempt were made until fresh air was reached in the ordinary way.

Isolation of Fluorine.—A demonstration of the isolation of fluorine was made before the British Association by Dr. Meslans, the representative of the French chemist, M. H. Moissan. The apparatus employed consists entirely of platinum and fluorspar. A powerful current of electricity is passed between platinum electrodes through anhydrous liquid hydrogen fluoride mixed with one of its salts, and cooled to a very low temperature by means of methyl chloride. Under these conditions fluorine is given off from one of the electrodes, and hydrogen gas from the other. The fluorine is an almost colorless gas, and its presence is made evident by its action on various compounds. Crystallized silicon, amorphous boron, phosphorus, sulphur, alcohol, and various metals take fire at the ordinary temperature and burn brilliantly in a current of the gas. These phenomena were exhibited to the section, and the demonstration was in every way