PAPERS OX PSYCHOLOGY AND EDUCATION 357 



electric motor himmiing at his side. Even without these 

 precautions it was impossible for any one of about 

 twenty-five students and for several disinterested visitors 

 who are competent critics of experimental work to hear 

 what was going on. 



Visual stimuli were employed as aids whenever a new 

 word was being added to the tactual vocabulary. When 

 the subject saw the word "Bay", for example, displayed 

 upon a card, he knew that the next tactual impressions 

 upon his palm would be such as arise from speaking that 

 word into the tube. The visual tactual connection was 

 repeated as often as necessary to establish the associa- 

 tion, and new words were added as rapidly as possible. 



At the end of the academic year the subject had at- 

 tained an accuracy of from 88% to 95% in the recognition 

 of 200 word impressions. (Each word in the vocabulary 

 repeated several times.) 



Up to this time practice had been only with the right 

 hand. On the last day of April, which was the last day 

 of practice, the left hand was employed as the right one 

 had been used theretofore, and recognition proved to be 

 quite as accurate as with the other hand. This result 

 suggests that we are not dealing here with an absolute 

 increase in sensitivity but with a control of attention di- 

 rected toward small differences in tactual stimulation. 

 On the same day we made another crucial test at the sug- 

 gestion of Professor McDougall. A list of eight monosyl- 

 labic words was prepared upon no one of which the sub- 

 ject had practised. He recognized six of the eight. This 

 indicates, I believe, that the vowel sounds in these words 

 had become isolated in the course of the development of 

 the vocabulary of 34 words, even though no specific at- 

 tempt had been made in that direction. 



Four months after the last test in April, 1923, after a 

 summer of no practice, the subject was tested again by 

 the method with which he had become familiar. On this 

 day he recognized 71% of the 200 tactual stimuli: a loss 

 of 30.5% on the basis of his maximum record in April. 

 The stimuli and method employed in this test were those 

 that were in use on the last clay of practice in April. 



