Page:Popular Science Monthly Volume 53.djvu/442

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to regulate the supply in a hygienic way by control of its sources. For this reason some general method of purification, which can be applied to the milk in bulk after it has been collected, becomes an essential to a safe product for general consumption. The ordinary tests, while fairly accurate in determining adulteration, are of no value in indicating the presence of disease germs or ordinary dirt. In fact, nearly any sample taken from the milk wagons of a city will be found to contain a number of bacilli which would immediately condemn any water as unfit for drinking. Sand filtration has been practiced for several years in some Continental cities, and apparently with very satisfactory results. The filters used by Messrs. Boll, large milk dealers of Berlin, consist of cylindrical vessels divided by horizontal perforated diaphragms into five superposed compartments, of which the middle three are filled with fine, clean sand, sifted into three sizes, the coarsest being put into the lowest and the finest into the uppermost of the three chambers. The milk enters the lowest compartment, and, having traversed the layers of sand from below upward, is carried by an overflow to a cooler fed with ice water, whence it passes into a cistern, from which it is drawn direct into the locked cans for distribution. The filtered milk is not only freed from dirt, but the number of bacteria is reduced to about one third, without sterilizing. The loss of fat is, in new milk, stated to be small, but the quantity of mucus and slimy matter retained in the sand—which is, of course, renewed every time—is surprising.

 

Spirit Drinking and Mental Depression.—Facts brought out by Mr. Bateman, of the British Board of Trade, in reference to the amount of drinking in different countries make the people of the United Kingdom more moderate in their drinking habits than has generally been supposed, and place them among the more temperate nations; for while in the consumption of beer, SO.T gallons a head, they exceed the Germans as a whole with 25.5 gallons a head, the relatively small quantity of wine drunk, less than half a gallon per head, as against 29.50 gallons in France and the adjoining countries, more than restores the balance. And this result is not changed when the stronger drinks than wine are taken into consideration—1.9 i gallons per head in Germany, 1.85 in France, and 1.01 in the United Kingdom. The Bavarians are the greatest beer drinkers, consuming an average of fifty gallons each in a year; next to them are the Belgians, with 43 gallons. The United States appears in the table as a vastly more temperate nation than any of these, its average rate of consumption of beer, wine, and spirits being less than half that of Great Britain. The London Spectator, taking Mr. Bateman's tables as its text, tries to find a mental rather than a physical cause for the appetite for drinking, and discovers it in the use of spirits as a means of obtaining relief from depression. In the United States, where the climate is exhilarating, life is easy, and the people are satisfied, drinking is decreasing; while "it is in France that drinking is now most prevalent, and is assuming the form least connected with the actual enjoyment of fermented liquor." Though wine is plenty and all are trained from childhood to drink it, the people "are taking to strong spirits of peculiarly nasty flavors," and some are spending nearly half their wages upon them. This, it thinks, is because "in France more than in any other country the people are becoming depressed and pessimistic, partly through the general loss of their faith, partly through a consciousness that they are not as great in the world as they think they ought to be, partly through the rise of the savage pecuniary discontents which produce what we are accustomed to call socialism."

 

Insects, and Books about them.—In a Brief Historical Survey of the Science of Entomology, by C. L. Marlatt, president of the Entomological Society of Washington, an estimate is made of the extent of entomological literature. Hajen's Bibliotheca, in 1862, listed 4,766 authors, 18,130 distinct titles, and 851 anonymous publications. The last volume of the Zoological Record, for 1895, gives 1,251 titles of publications on insects, which might perhaps be equivalent to seventy-five 500-page volumes; and Mr. Marlatt supposes, as a very conservative estimate, that what would amount to 2,000 such volumes have been published since the date of Hajen's work. In economic entomology, Henshaw's Bibliography of 1888 contains 5,424 titles and the names of more