Page:The World and the Individual, Second Series (1901).djvu/99

serial order-systems of rocks, fossils, formations. Nor does this character cease to mark the conceptions of science when one passes to chemistry, to physics, to astronomy, or to mechanics. The serial system of the chemical elements, which forms so important a topic of consideration in recent chemistry, is a notable example of how various masses of facts which once seemed in certain respects ultimate and mutually sundered, tend, upon further examination, to assume their places as stages of a single, though highly complex, order-system. Any natural process which is capable of a mechanical description, — such as the processes studied in the more exact regions of physical science, — is made comprehensible by conceiving all of its occurrences as stages in a single series, or system of series, of what the mathematicians call “transformations.” Such a series of transformations is exemplified by the successive states of a body cooling under definable physical conditions, or by the successive configurations of a system of bodies moving under the influence of definable forces. In astronomy, the apparent places of the stars are reduced to order by the use of a system of astronomical coördinates, just as we reduce to order our knowledge of geographical positions on the earth’s surface by the conceptions of latitude and longitude. But such ways of viewing facts are conceptions of definitely complex order-systems of places. In recent astronomy, moreover, the classification of the stellar spectra has led to a still tentative arrangement of stars in order-systems whose bearing on problems of evolution seems to be important. At all events, one thus finds a new sort of definable relation between the physical processes