22 DAVID I. MACHT AND SHACHNE ISAACS 



all experiments. In one series the subject was requested to add 

 17 mentally to a two-figure number, such as those given in the 

 following table (table 1), and to announce the sum as quickly 

 as possible through a telephone arrangement which breaks the 

 circuit and stops the clock. In the second series a more difficult 

 task was given to the subject. The experimenter in this case 



TABLE 1 TABLE 2 



Exercise: Add 17 mentally and Exercise: Multiply by 8 and add 



respond 4 and respond 



22 35 29 64 



71 58 76 27 

 68 41 55 46 

 46 75 48 23 



33 38 24 69 

 64 67 79 33 



51 54 54 65 

 32 28 47 22 

 59 47 58 53 



73 26 75 67 

 29 43 49 39 

 56 31 68 52 



48 66 35' v 61 



34 57 71 36 

 62 42 37 28 

 78 24 66 73 

 25 55 45 44 

 39 27 34 31 



74 79 21 25 



52 45 78 74 

 77 21 51 77 



49 63 26 43 

 44 23 72 59 



72 37 32 63 



53 61 41 56 

 76 65 38 42 

 36 64 57 62 



announced a two-figure number and the subject was required to 

 multiply the same by 3 and add 4 to the product, and then 

 announce the result through the speaking disc, thus recording 

 the reaction tune (table 2). 



In each test twenty numbers were generally employed at 

 each sitting. This method furnished quite a complicated asso- 



