It was a wasp, too, which suggested to Reaumur, as he examined its nest, that wood might well serve as the raw material for paper, and serve it does to the amount of millions of tons a year. To-day we have as a new fabric for garments, glanz-stoff, an artificial silk produced from cellulose; its German manufacturers have imitated as nearly as they could the silk-worm’s thread, just as for some years the filaments for incandescent lamps have been made from liquid cellulose forced through minute holes. At first bamboo fibres were used for this purpose; to-day art furnishes a thread of more uniform and lasting quality. This achievement is of a piece with many another. To-day when an inventor seeks to imitate a natural product he does so with a power of analysis, a wealth of new materials, such as his forerunners could not have imagined. It is in laboratories stocked more diversely than ever before, with their resources better understood than at any earlier time, that the triumphs of modern ingenuity proceed. The Separating Task of the Lungs. In all likelihood one of the feats of nature soon to be paralleled by art, in an economical way, will be one phase of the breathing process; every time we inflate our lungs their tissues perform a feat which has thus far baffled imitation except in a roundabout and wasteful manner. Air is a mixture of oxygen and nitrogen; the work of life is subserved by the oxygen only, which is separated from air by the lungs and passed into the current of the blood. Oxygen and nitrogen, like any other two gases, tend forcibly to diffuse into each other, as we may see in the distension of a thin rubber sheet dividing a container into two parts, one filled with oxygen, the other with nitrogen. To overcome the force of diffusion which keeps together the oxygen and nitrogen forming a cubic foot of air, of ordinary temperature, would require such an effort as would lift twenty-one pounds one foot from the ground. This task the lungs accomplish by means which elude observation or analysis. It would mean much to the arts if this parting power could be imitated simply and cheaply. In common combustion each volume of oxygen which unites with the fuel, carries with it four volumes of nitrogen which have to be heated, not only reducing the temperature of the flame, but removing in sheer waste much of the heat. A supply of oxygen free from admixture would double the value of fuel for many purposes, creating a temperature so high that it would be difficult to find building materials refractory enough for the furnaces. Cheap oxygen would greatly increase the light derivable from oil and gas, as proved in the brilliancy of an oxyhydrogen jet. In bleaching and in scores of other processes, oxygen is so valuable that, notwithstanding its present cost, the demand for it steadily increases. Cannot the lungs, chemically or mechanically, be copied so as to yield this gas at a low price for a thousand new services?