Page:Popular Science Monthly Volume 23.djvu/818

798  up their feathers, putting themselves in the shape of a ball, and surrounding themselves with the thick strata of air included within the filaments of their plumage. We purpose in another article to consider the relations of our habitations to the atmosphere.—Translated for the Popular Science Monthly from the Revue des Deux Mondes.



N the last quarter of a century, very important progress has been made in our home industries and foreign commerce; but certainly the success that has been effected in the utilizing of waste products, and developing neglected ones, is not the least remarkable of recent scientific advances.

It is evident that, when considered from the point of view of industrial science, the phrase, "utilization of waste," may be fairly applied not only to the unused residual products of manufactures, but to the boundless, undeveloped wealth of nature. The beautiful aniline dye, produced from the tar of the gas-works, is not more an example of the utilization of waste than beet-root sugar, obtained from what, a century ago, was a weed growing by the sea-side. Nature produces, abundantly and spontaneously, in many countries, vegetable substances (such, for instance, as the esparto-grass), which were long allowed to run to waste. Important industrial uses have been found for many of them, and fortunes realized by numbers who have turned their attention toward rendering them articles of commerce.

The flesh of domestic animals fit for food is almost a waste substance in many countries, since it can not be locally consumed nor profitably preserved. In the River Plate republics alone there are 80,000,000 sheep and 25,000,000 cattle to a population of 2,500,000. For years sheep were only valued there for their wool, and, when flayed, carcasses were left to rot, or, when dried in the sun, piled up in stacks for fuel, while later on they were boiled down for their tallow. Sheep get very fat in the province of Buenos Ayres, and those of three and four years will give frequently from eighteen to twenty-five pounds of tallow. Countless numbers of sheep are boiled down every year in the so-called graseŕias only for the tallow, which forms one of the staple articles of export. The mutton is thrown away, or used in a dry state as fuel.

In the five years ending with 1850, more than 1,500,000 sheep and 200,000 horned cattle were boiled down simply for their tallow, in the colonies of New South Wales and Victoria. 