4 T. L. Bolton and Donna L. IVithey 



always taken not to press the hand too closely, and the reagent 

 was urged to indicate any discomfort that might arise from "over- 

 pressure or too long continuance of the experiment. Even where 

 the hand is not confined, and small pressure is exerted upon any 

 skin area, there is an almost irresistible tendency for reflex mus- 

 cular contractions to begin. This relation of mviscular contrac- 

 tion to stimulation is important and fundamental and will receive 

 consideration later. Sometimes the hand was padded with view 

 to equalizing the pressure over the back, but it was not done all 

 the time and finally discontinued as it seemed to be of no especial 

 advantage ; the hand appeared to be no more comfortable and it 

 was no aid to clear discrimination. In fact, it seemed at times 

 to be disturbing or distracting, from the fact the padding always 

 gave way under the pressure and this drew the attention from the 

 contact on the palm and made the discrimination depend upon 

 different degrees of recession upon the part of the padding. 



The method employed was a modified form of the gradation 

 method or the method of minimal change. The standard pres- 

 sure was that represented by a weight of 165 grams set at a dis- 

 tance' of 150 mm. from the pivot of the balance. As the stimulus 

 magnitudes were always proportional to the distances the weight 

 was set from the pivot, the actual weight can be dispensed with 

 and the stimulus magnitudes represented by the graduations upon 

 the scale beam. They were then 150 (standard), 170, 190, 210, 

 230. and 250. The procedure was to present these magnitudes 

 in pairs, the standard and a compared weight in close succession. 

 The standard came first in all cases. The compared weights were 

 presented, each with the standard, generally in the order here 

 given or in the reverse order. Variations were sometimes intro- 

 duced to guard against the reagent taking cue, and to break up 

 as far as possible the expectation of a difference or a no-differ- 

 ence, and hence avoid a declaration of a difiference or a no-dif- 

 ference when none was really felt. Expectation is bound to enter 

 and exercise some influence upon judgments even after the re- 

 agent should have become habituated to the mode of conducting 

 the experiment and so looking upon it with entire indifference as 

 to the outcome. 



178 



