1897.] Psychology. 459 
the list was read the subject wrote the numbers down as he re- 
membered them. The series consisted of from 6 to 10 figures. The- 
number of errors was taken as inverse measure of memory capacity. 
3. Combination. Prose sentences were given (in writing), with words, 
Syllables and groups of letters here and there omitted; the pupil 
was told to fill in the omissions. The number of syllables supplied 
within five minutes and the number of errors made in filling in were 
both taken into account. (The latter is open to criticism, since a false 
filling in of the text might, in certain cases, make as good sense as the 
óriginal.) Prof. Ebbinghaus’s tests were made on 15 classes of boys 
and 11 of girls of all grades ; the same hours and days of the week were 
used in every case. The results showed in general an increase in exact- 
ness and capacity for work, corresponding to the increase in average 
age of the class; but this was subject to individual variations, a lower 
class being in some cases better than the next higher, although about 
a year younger on the average. The Combination method gave greater 
differences according to age than the Calculation method ; the Memory 
method, in the application of which the individuality of the instructor 
played considerable part, showed irregular results. Dividing each 
class into three parts, according to scholarship, the methods gave quite 
different results. The memory tests showed no marked difference be- 
tween good and bad scholars—if anything, it favored the latter; calcu- 
lation showed a slight decrease from higher to lower; the combination 
tests, on the other hand, showed a marked difference in favor of the 
better scholars, as regards both the number of syllables supplied and 
the freedom from error. Comparing boys with girls, the latter were 
found to be inferior in the lower classes, but were somewhat superior in 
the highest classes; from which was argued a more rapid mental de- 
velopment among girls from the 12th to the 15th year. As to fatigue, 
the results agreed in general with those of Burgerstein and Laser. The 
capacity for work increased steadily to about the end of the third school 
hour, and then decreased somewhat, rising sometimes at the end of the 
school day. But the number of errors increased steadily throughout 
from the start. 
Dr. Friedrich employed two methods in his tests. 1. Dictation. 
Twelve sentences were given, of about the same number of letters and 
signs, and about the same degree of difficulty. 2. Caleulation. This 
consisted of five sums of two 20-place numbers, and five multiplications 
of 20-place by 1-place numbers. Each test was made at the beginning 
of the school day and at intervals of one hour. Some days a recess of 
8 or 15 minutes was allowed between the hours, on others the lessons. 
