Many remarks scattered through" this 
little treatise are worth the re Election of 
all ages and classes, “ The failure of 
the mind in old age,” says Sir Benjamin, 
“is often less the result of natural decay 
than ol disuse.” Ambition has ceased 
to operate ; contentment brings indolence; 
indolence decay of mental power, ennui 
and sometimes death. Men have been 
known to die, literally speaking, of disease 
| induced by intellectual vacancy. On the 
; other hand, the amount of possible men- 
tal labor is far less than many persons 
•imagine. If professional men are ena- 
bled to work twelve or fifteen hours dai- 
ly, that is because most of their business 
has become, from habit, a mere matter of 
routine? From four to six hours is, 
probably, the utmost daily period _ for 
which real exertion of the mind can" be 
carried on. 
X* 
