June 10, 1904.] 



SCIENCE. 



891 



the conditions of the railway service can he 

 imitated, it here being necessary first to dis- 

 tinguish a certain color and then to make the 

 proper movement. 



The Time of Perception as a Measure of Dif- 

 ferences in Sensation: Y. A. C. Henmon. 

 The aim of the investigation upOn which 

 this paper is based is to measure qualitative 

 differences in color by the time of perception. 

 The colors taken as standards were red, 

 orange and yellow, whose wave-lengths had 

 been definitely determined. Equal inter- 

 mediate steps between orange and red were 

 produced by the mixture of pigments. Small 

 squares of each of these colors, 3x3 cm., were 

 mounted on cards side by side with red, and 

 exposed to the subject by raeans of a drop- 

 screen so arranged as to give almost instan- 

 taneous exposure. The subject reacts with the 

 right or left hand according as the predeter- 

 mined stimulus appears to the right or left. 

 The registration is made with the Hipp chrono- 

 scope. The results of 6,000 reactions gave 

 evidence of the validity of the method and the 

 fruitfulness of the problem. Equal objective 

 difl'erences are correlated with differences for 

 consciousness, showing a definite increase as 

 the magnitude of difference is decreased. 



The Daily Curve for Efficiency; Mr. H. D. 

 Marsh. 



Habits Based on Analogy : Professor Charles 



H. JODD. 



The Determination of the Haiit Curve for 

 Associations : Professor J. E. Lough. 

 A report of experiments made in the psy- 

 chological laboratory of the school of peda- 

 gogy. It was found that the time required to 

 vsrrite series of letter-equivalents when the 

 * key ' of equivalents was not memorized, but 

 was consulted as frequently as necessary, di- 

 minished as the associations between the letter- 

 equivalents became more habitual. The curves 

 representing the results of these experiments 

 exhibit all the characteristics of the typical 

 habit curve. Eepetition of the experiment 

 using new ' keys ' shows little or no interfer- 

 ence due to earlier associations, while with 

 each succeeding ' key ' the physiological limit 



was reached after a constantly diminishing 

 number of trials. 



A Neglected Point in Hume's Philosophy: 



Dr. William P. Montague. 



The paper aimed to show (1) that Hume 

 (in Part IV., Section II. of the 'Treatise') 

 had quite unwittingly furnished what from 

 his own point of view should have been re- 

 garded as a logical deduction and justification 

 — rather than the mere psychogenetic descrip- 

 tion, which it purported to be, — of the real- 

 istic belief in the independent and urdnter- 

 rupted existence of sensible objects; and (2) 

 that the naive realism or positivism thus ac- 

 cidentally promulgated was from both the sci- 

 entific and the popular standpoint, a far 

 sounder and more inviting doctrine than the 

 empirical idealism or sensationalism with 

 which Hume's name is usually associated. 



Action as the Concept of Historical Synthesis: 



Mr. Percy Hughes. 



Eickert's description of the content of his- 

 tory as reality is amended to read past reality, 

 the past of evidence. Erom this definition the 

 individual, objective, moving and continuous 

 character of historic content follows; and 

 further, the conception of action as descriptive 

 of both historic content and historic synthesis. 

 An historical synthesis is a past action that 

 itself has created a certain synthesis of evi- 

 dence ; which the historian discovers. In such 

 synthetic actions, ' simple ' actions retain their 

 individuality as means, stimuli or hindrances 

 to the main action, i. e., in a functional rela- 

 tion. 



At the close of the afternoon session the 

 members were invited to attend a lecture given 

 in Columbia University by Professor John 

 Dewey on ' The Psychologist's Account of 

 Knowledge.' 



James E. Lough, 

 Secretary. 



SECTION OF geology AND MINERALOGY. 



The section held its regular meeting Mon- 

 day evening, May 16, with the chairman. Pro- 

 fessor James E. Kemp, presiding. 



The following program was offered : 



