FECHNER AND PSYCHO-PHYSICS
IT is more than time that we started to deal seriously with the developments of experimental psychology in our second period, for, as the reader will have observed, the experimental method has for some little while been constantly intruding itself into our discussion, though we have on the whole endeavoured to avoid it and to confine ourselves to evolutionary and systematic psychology. We have seen, for instance, how Galton's fertile mind linked up psychological experiment with the evolutionary outlook, and how the same fusion was later on made by Thorndike in the case of animal psychology. We have seen, too, how James, the literary genius of psychology, was both attracted and repelled by the new school. It is now our business to examine the birth and progress of this movement, which we have hitherto sensed as an important background to the developments we were considering.
The first nineteen years of our second period (from the appearance of Fechner Elemente in 1860 to the foundation of Wundt's laboratory in 1879) differs from the later part of this period in that interest centres round some half- dozen names only, of whom three, Fechner, Helmholtz and Wundt were stars of the first magnitude. With the work of the two first of this trio we are already to some extent familiar. We have seen how Helmholtz measured the speed of the nervous impulse and how Fechner arrived at the ideas embodied in his Elemente, the work which is usually regarded as marking the definite beginning of the