EXPERIMENTS AND OBSERVATIONS 87 



ments and to have made Hans the object of further 

 psychological investigations, but unfortunately he was no 

 longer at my disposal after the publication of the report 

 of the December-Commission. Some may say that we 

 have had almost enough of a good thing, but we must bear 

 in mind that many of the tests which were carried out, — 

 such as those in which the method was that of " procedure 

 without knowledge ", those in which the ear-muffs were 

 used, those in which distractions were introduced, — had 

 previously been made by other persons (see pages 41 f, 

 45. 63), and with other results, than ours. A more thor- 

 ough test, therefore, would have been doubly desirable. 



