GUSTAV THE ODOR FECHNER 47 



meters or inches, and for pounds or ounces. Taking up these hints, 

 Fechner ransacked the choir of heaven and the furniture of earth to see 

 if this general relation which, with characteristic modesty, he called 

 Weber's law, did not hold true for all kinds of impressions, for sounds, 

 for colors, lights, temperature, short intervals of time; he even ques- 

 tioned if it did not hold for our feelings ; in short, if it was not a funda- 

 mental law of human activity. With characteristic thoroughness he 

 launched forth into new seas of experimentation. He tells us: 



For several years I considered it a daily task to experiment about an hour 

 for the purpose of testing Weber's Law and for elaborating new methods of 

 research. 



This daily task consisted in "hefting" and comparing pairs of 

 small weights, in analyzing out the multifarious factors involved in 

 judgments of likeness or difference and in noting the results. In so 

 far as Weber's law is concerned it can not be said that the outcome of 

 this vast accumulation of data is decisive, but so far as regards the 

 working out of psychophysical methods of measurement, the experimen- 

 tation was extraordinarily fertile. For the development of the Fech- 

 nerian methods meant that Fechner had founded a new science and 

 reared somewhat of its superstructure in a domain whose only uniform- 

 ity seemed boundless variability, and that later psychology has failed to 

 find either the universality or the exactness in Weber's law which Fech- 

 ner hoped to show is assuredly a matter of small importance in com- 

 parison with the birth of a quantitative psychology. 



In the latter part of the treatise Fechner passes over to discuss what 

 he calls " Inner Psychophysics," and here we strike a mine of acute and 

 subtle psychological observations on sleep and dreams, on hallucina- 

 tion and illusions, on memory and after-images from which most writers 

 of text-books and no small number of investigators up to the present 

 day have " lifted " no small amount of ore. Taken as a whole, from the 

 first remarkable chapter, remarkable at that day, on the conservation of 

 force, through the mathematical treatment of methods of "mental 

 measurement" up to the final discussion of psychophysical motion, the 

 " Psychophysik " is a work which in the library of science one need not 

 fear to place on the same shelf with the " Origin of Species." 



If the importance of a work is to be measured by the number and 

 repute of its critics, Fechner had no longer any cause for feeling that 

 his theories were of no significance to the learned world, for among the 

 cloud of witnesses who rose up to testify against the "Psychophysik" 

 we find the names of v. Helmholtz, Hering and Mach, and later Wundt 

 and G. E. Miiller of Gottingen. Indeed so acute and penetrating was 

 the criticism of Miiller, that Fechner was obliged to defend himself in 

 a new work entitled "Eevision of the Main Points of Psychophysics." 

 Later on he wrote a sort of omnibus reply to all his critics and up to the 



