Page:Popular Science Monthly Volume 52.djvu/735

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FRAGMENTS OF SCIENCE.

some time afterward, mainly a record of numerous governmental experiments covering the leading features of economic life. The results were mostly of a negative character, but were valuable for the student. Study of the conditions in French Canada should be accompanied by a study of the conditions that prevailed in France, England, and the English colonies. The differences between the colonies were due not so much to their location, their race, or their products as to the regulations by which they were controlled. The French bureaucratic system, with its tendency to minute interference with every aspect of social life, was opposed in New England by a system which left to the colonists the utmost liberty in the practical direction of their affairs. Much good was accomplished in Canada under the influence and direction of Colbert, but as much or greater harm was done by incompetent administrations later. In Canada despotism was tempered by access to the woods, those too heavily burdened readily taking to the ways of the savages, a fact that gave the French an influence upon the Indians greater than could have been expected, inasmuch as their pecuniary advantages lay almost altogether with the English. Although in theory the English colonies were dependent for all things upon the home government, they were largely left to themselves, and when George III thought to atone for past neglect by vigorous administration it was found that the lapsed authority could not be recovered. Thus, while in Canada a colony had grown up dependent on European influences, the English colony had become accustomed to look to itself for all things. The whole study was presented as emphasizing the necessity in theoretic economics of keeping in mind differences in conditions and in their range of operation and influence.

Singing Flames.—In a recent number of the American Journal of Science, Mr. H. V. Gill has an interesting paper on The Theory of Singing Flames. The phenomenon of a gas jet burning inside an open tube, emitting a musical note, is one of those facts which, although known for many years and much written about, has never been fully explained. Among the more interesting theories was that of De la Rive, who supposed the sound to be due to a periodic condensation of the water vapor produced in the combustion of hydrogen gas. Faraday showed the inadequacy of this theory by the use of a flame which did not form water vapor, and proposed in its stead the theory that the so-called singing was caused by successive periodic explosives of a mixture of gas and air. This was accepted by Tyndall. Another theory which has been proposed is that the sound is produced by vibrations maintained by heat, the heat being communicated to the mass of air confined in the sounding tube at a place where in the course of vibration the pressure changes. Sondhauss performed a series of experiments, his chief conclusion being that the condition of the column of gas in the supply tube had an important influence on the phenomena. Mr. H. V. Gill sums up his conclusions as follows: "We think we have made it clear that the pressure on the gas plays the important part in this phenomenon, and that a consideration of the reactions we have described will be found to explain the many facts noted in the case of a singing flame, some of which we have alluded to. We look, therefore, on the chief cause as a mutual reaction between the pressures in the tube and on the gas, the energy necessary to sustain the note being supplied by the pressure on the gas and the action of the flame. We may compare the singing flame to the siren, in which the current of air causes the disk to rotate, the note being produced by the reaction of the disk on the current of air. . . . We have, then, three kinds of singing flames, one depending on changes of pressure, another on air currents, and a third depending at once on both changes of pressure and on air currents."

Sanitariums for Consumptives.—The urgent need of sanitariums for the consumptive poor in our large cities was forcibly presented by Dr. S. A. Knopf in a paper which he read before the American Public Health Association in October, 1897. The author shows, in the first place, that the homes of these invalids are as unsuitable as they can be for their proper treatment; that with them their families and fellow-tenants are sure to be infected, and the neighborhood is in danger. Neither can they properly be received in the general hospitals, where the