48 TEE POPULAR SCIENCE MONTHLY
very year of his death he carried on the psychophysical war with un- abated vigor. His last extensive article, written in his eighty-sixth year, was on " ^Yebe^'s Law/' and Wundt's judgment on it is that it was the clearest and most perfect presentation of the subject which Fechner had given in the course of his forty years work in psychophysics.
The seeming hopelessness of psychology as an exact science lies in the perplexing multiplicity of the variable factors perturbing every at- tempt to determine facts and laws — errors of memory, errors of obser- vation, errors of contrast and expectation, the brood of errors hatched by the changing rhythms of attention — and it was to devise ways of sifting out these errors that Fechner for years devoted his tireless ingenu- ity. But a satisfactory treatment of such conditions means the accumu- lation of large numbers of observations, which in turn calls for statis- tical handling of the materials gathered. Here again Fechner's genius found a fresh field to cultivate, for in endeavoring to see if some gen- eral principles were not at work in shaping what may be broadly called esthetic proportions, such as those of picture frames, visiting cards, decorative crosses and the like, he found that these classes of objects varied in their dimensions like the variations in the sizes of races of men, species of animals, like variations in temperature and rainfall and countless other objects in art and nature termed by Fechner " Collec- tive Objects," " Collective Gegenstande." Mathematical analysis of the data in this field resulted in the formulation of a branch of statistics or applied mathematics which has become exceedingly useful in working out biological problems. Nor did he rest here; keenly interested in art (he contributed five articles to the cause celeb re of the genuineness of the Holbein Madonna, Dresden vs. Darmstadt), he followed up his in- vestigation on simple esthetic proportions with a general investigation on esthetic laws carried out in the spirit of the psychophysics "von unten auf" by observation and by experiment. And here be it said that if there is any trait of Fechner which amazes a student of his work more than aught else, it is his incredible ingenuity in applying experi- mentation to problems where no one dreamed that experiment could be applied. "Well! " Kurz und gut." In his seventy-first year he pub- lished the "Vorschule der Aesthetik" in two volumes and therewith created the science of experimental esthetics — the third and last dis- tinctive product of his creative genius. His last published work was a clever and witty critique of the Mendel Fountain in Leipzig.
What has so far been set down here got itself delivered substantially as it stands, some eleven years ago, on the occasion of the centennial of Fechner's birth. Since that time the tide of Fechner's fame has swollen until it has overflowed into the German popular magazines. The " Zend Avesta " has passed into the third edition, the soul-question