1893.] The Quantity of Human Life. 197 
2° = 8 and (2-84 F = 22-44. Now in order that the individ- 
ual with double the surface of contact may encounter twice as 
many stimuli as the other, when both are moving through 
their environment, it must move the same distance as the 
other. In moving such a distance however, it will perform 
not twice but nearly three times the amount of work that the 
other performs since it will transport nearly three times the 
weight. Thus, if the expenditure of muscular energy detracts 
from the stock of vitality, and hence dulls the keenness of the 
sensibilities, even though the surfaces of contact of the two 
individuals possess initially the same degree of sensibility 
by reason of that impairment, the larger animal would expe- 
rience less than twice as much consciousness as the smaller. 
Viewed from another standpoint, the smaller animal could 
execute more than twice the velocity of the larger with equal 
expenditure of strength, ,(disregarding the resistance of the 
medium), and hence it would encounter more than an equiva- 
lent number of experiences. 
It was here assumed that equal surfaces of contact conveyed 
equal quantities of sensibility in the two individuals, but it 
is well known to physiological psychologists that there are 
immense differences in the relative acuteness of the different 
sense organs in the same individual, and in the same sense 
organs in different individuals. The optical, auditory and 
tactile powers are quite variable. Probably the experiential 
products of all the other senses combined do not equal those 
which come through the medium of vision. It will thus be 
readily inferred that the extent of surfaces of contact is less 
important in relation to the experiences of the conscious life 
than their quality; and the movements of the individual 
tending to multiply experiences are less important than the 
movements of the environment. For example, an observer 
standing on a street corner in a great city, or riding in a rail- 
way coach at forty miles an hour, will gather more experiences 
than he would were he to run atthe top of his speed in a 
deserted field. Doubtless he might experience a high degree 
of exhilaration at first, yet experience of effort would prevail. 
Such experiences like all other somatic feelings have a place 
