EXPERIMENTAL PSYCHOLOGY 



the doctrine of color vision which that other great 

 physiologist and physicist, Thomas Young, had ad- 

 vanced half a century before. The same tendency 

 was further evidenced by the appearance, in 1852, of 

 Dr. Hermann Lotze's famous Medizinische Psychologic, 

 oder Physiologie der Seek, with its challenge of the old 

 myth of a "vital force." But the most definite ex- 

 pression of the new movement was signalized in 1860, 

 when Gustav Fechner published his classical work 

 called Psychophysik. That title introduced a new 

 word into the vocabulary of science. Fechner ex- 

 plained it by saying, " I mean by psychophysics an 

 exact theory of the relation between spirit and body, 

 and, in a general way, between the physical and the 

 psychic worlds." The title became famous and the 

 brunt of many a controversy. So also did another 

 phrase which Fechner introduced in the course of his 

 book the phrase "physiological psychology." In 

 making that happy collocation of words Fechner virt- 

 ually christened a new science. 



FECHNER EXPOUNDS WEBER'S LAW 



The chief purport of this classical book of the Ger- 

 man psycho - physiologist was the elaboration and 

 explication of experiments based on a method intro- 

 duced more than twenty years earlier by his country- 

 man E. H. Weber, but which hitherto had failed to at- 

 tract the attention it deserved. The method consisted 

 of the measurement and analysis of the definite rela- 

 tion existing between external stimuli of varying de- 

 grees of intensity (various sounds, for example) and 

 the mental states they induce. Weber's experiments 



VOL. iv. 18 263 



