Page:Popular Science Monthly Volume 31.djvu/813

Rh trees—yield on an average not over 2 per cent of quinine, the bark of the cultivated tree in Java is reported to yield from 8 to 12 per cent.

The decline in the prices of many chemicals, due to improvements in methods and to excess of production, has also been very great the decline in soda-ash from 1872 having been 54 per cent, while bleaching-powders (chloride of lime) declined from £10 in 1873 to £6.15 in 1878, reacting to £9 in 1887.

Many other commodities, of greater or less importance, might be included in this investigation, with a deduction of like results; but a further exhibit is not necessary. For it is difficult to see how any one can rise from an examination of the record of the production and price experiences of the commodities which have been specified, which, it must be remembered, represent—considered either from the stand-point of qualities or values—the great bulk of the trade, commerce, and consumption of the world, without being abundantly and conclusively satisfied that the decline in their prices, which has occurred during the last ten or fifteen years, or from 1873, has been so largely due to conditions affecting their supply and demand, that if any or all other causes whatever have contributed to such a result, the influence exerted has not been appreciable; and further, that if the prices of all other commodities, not included in the above record, had confessedly been influenced by a scarcity of gold, the claims preferred by the advocates of the latter theory could not be fairly entitled to any more favorable verdict than that of "not proven."

But have all other commodities, for which conclusive evidence of a recent greatly-augmented production can not be adduced, exhibited in their recent price movements any evidence of having been subjected to any influences attributable to the scarcity of gold? For the consideration of this question, reference is made to the next paper of this series.

advocates, in the "Popular Science News," a system of international co-operation in meteorological observation. We need it in order to obtain a wider field whence to draw data for forecasts, so that we may make them for longer periods; for the proper study of the "meteorological unit," which the whole North Atlantic basin constitutes; for the proper determination of the work and influence of the Gulf Stream and of the Pacific Current; for the investigation of variations of the sun's heat, the field of observation for which should cover nearly the whole earth; and for the study of extra-meteorological phenomena like earthquakes and earth-tremors. We can hardly determine what is of importance to the climates of Europe and America without a pretty thorough study of all the great climatal units of the earth. The seven nations, Great Britain, the United States, France, Germany, Russia, Spain, and Holland, with their colonies, are so situated that, with their co-operative action, no great area of the earth, except the polar regions and the central oceanic areas, need be without regular frequent observations in aid of these studies.