Page:Popular Science Monthly Volume 43.djvu/862

842 said that for nearly forty years the system of Linnæus stood in the way of the better system of Jussieu and De Candolle; that system in its turn has for a third of a century been a clog and a hindrance to the adoption of the vivifying idea that genetic ties are the true basis for classification. The botanist in giving this new and illuminating order to plants must be careful to discriminate between primitively simple forms and those simple by derivation. Parasites are far from being the only plants that have undergone simplification of structure; in willows and poplars, for example, a single ovary has resulted from the union of two or three ovaries. For flowering plants Prof. Bessey presented in detail a revised arrangement of the Benthamian series.

The Mutual Relations of Science and Stock-breeding gave Prof. W. H. Brewer, in his address to the Economic Section, an opportunity of showing how an art is broadened and bettered when it flowers into a science. Until Darwin's Origin of Species was published stock-breeding followed the rule of thumb, with results slow and uncertain; today, when heredity is understood as due to influences largely calculable and controllable, stock-breeding almost rises to the assuredness of aplastic art. Prof. Brewer spoke of a sheep-breeder of his acquaintance who has all the ideality of the true artist, who figures to himself a perfect sheep with every good point at its best, every defect eliminated; in striving to give substance to that form as he imagines it, this man is as devoted as any wielder of chisel or brush. Breeding, said Prof. Brewer, can alone decide whether acquired characteristics are transmitted, and it may even throw an important side light on vexed questions of education.

Prof. E. L. Nichols, in his address to the physicists on Phenomena of the Time Infinitesimal, showed a bullet in flight photographed in an interval so brief that the missile seemed at rest.

In another picture the bullet was shown in the act of shattering a pane of glass, with all the incidental perturbation of the surrounding air. In giving rapid motion to the sensitive plate Prof. Nichols pointed out how its availability can be vastly extended. In this field, he maintained, there is abundant harvest for the investigator, for when the time interval is appreciable we do not get a picture really instantaneous, but only a composite photograph whose elements we have to guess at. As to what happens in the first hundredths of a second in the polarization of the voltaic cell, in electrolysis, nothing is known, and here possibilities of the highest interest await the suitable application of the camera.

In reviewing twenty-five years' progress in analytical chemistry Prof. Edward Hart brought out its remarkable stimulus from the exigencies of industry, and the no less remarkable fashion in which the debt had been repaid. In 1868 the determination of phosphorus in steel required two to three days; today twelve minutes suffice. At the furnaces of South Bethlehem, Pa., a sample of molten metal is passed upon by the analyst while the iron is still on its way to the converter; the manufacture can thus be intelligently directed with the utmost promptness. This is but one of the important ways in which the chemist has borne a part in cheapening iron and steel. The work of analysis, in this and other departments, has been greatly quickened by developing those methods which allow the chemist to determine in a single specimen one constituent rapidly and accurately. It is preferable to determine phosphorus in one sample and sulphur in another than to determine each separately in the same sample. In closing his review Prof. Hart mentioned the honored chemists of America who have notably contributed to the world's advance in their science during the past quarter of a century—men little known to a nation richer, longer lived, and happier because of their