Page:Popular Science Monthly Volume 30.djvu/845

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By Professor W. PREYER,


FOR a long while I have felt the desire to answer in a popular treatise the question, What ways and aims ought physiology to pursue? Most naturalists consider the explanation of all phenomena, including those of living bodies, only satisfactory if mechanical—that is to say, if, in strict logical sequence, it is based upon the principles of modern physics as taught by Galileo nearly three centuries ago. Thus, G. Kirchhoff considers the highest aim which the natural sciences have to strive for to be the discovery of the "forces" existing in Nature and of the condition of "matter"; in other words, "the explanation of all natural phenomena by means of mechanical laws." The fact that besides the forces, which mechanics has to deal with, there exist, too, chemical forces independent of the former, is illustrated by an hypothesis: "The same particles of matter, which at a greater distance affect each other only through gravitation, manifest, when placed in proper proximity, molecular forces, which appear in their protean forms, now as forces of elasticity, of cohesion and adhesion, now as forces of chemical affinity." The proof to what extent chemical affinity is a molecular force dependent on the unequal proximity of bodies affecting each other chemically, is wanting. It also remains an open question whether at greater distances masses act upon each other only through gravitation. But, lest it should be inferred that inorganic nature only must be explained mechanically. Professor Kirchhoff, in accord with many naturalists, adds: "We must confess that at present we possess but little knowledge of the condition of matter as well as of the forces through which its particles act upon each other, and that our comprehension of natural phenomena, even of those connected with inorganic bodies, is as yet very imperfect. The same may be said with respect to the much more complex processes which take place in plants and in animate bodies. In either case a true conception can not be formed so long as the mechanical theory has not been satisfactorily demonstrated. This goal never will be reached by the natural sciences, but the mere fact of its having been recognized as such gives a certain satisfaction, and in approaching it we experience that highest enjoyment which the investigation of the phenomena of Nature affords."

I am unable to share that satisfaction, since I do not recognize such a goal as the true one, nor does the approach to it afford that high enjoyment, because of our progress being constantly impeded by facts. The processes in a living body, even in mere protoplasm, can not pos-

  1. Translated for "The Popular Science Monthly" from the "Deutsche Rundschau."