432 Longevity of Brain-Workers. [October, 
to use without abusing them; to draw from them only those 
lessons that they are really capable of teaching. Among 
those classes who live mainly by routine and muscular toil 
(mechanics, artisans, labourers, &c.) change of occupation 
is the rule rather than the exception, especially in this 
country ; and any statistics of mortality derived from the 
Registration Reports, are, so far as these classes are con- 
cerned, of but little value in the study of the relative effects 
of the different occupations on health and longevity. Another 
important complication arises from the fact that certain 
occupations, as clerkships, positions in factories, teaching, 
&c., are followed almost exclusively by the young and middle- 
aged; while other callings, as judgeships, are filled only by 
those in middle and advanced life. Another difficulty arises 
from the fact that some important occupations, as journalism, 
for example, are adopted only by a limited number; andthe 
number in them who annually die is too small to afford any 
basis for comparison. But this generalisation is, I am per- 
suaded, admissible, that the greater majority of those who 
die in any one of the three great professions—law, theology, 
and medicine—have, all their lives, from twenty-one upwards, 
followed that profession in which they died. The converse 
generalisation, that the great majority of those who die in 
the muscle-working avocations have all their lives followed 
some kindof muscle-working employment, however frequently 
they may have changed from one to another at different 
periods, is also true. Very few who once fairly enter theo- 
logy, medicine, or law ever permanently change to a purely 
physical calling; and, on the other hand, the number of 
those who begin life as farmers, labourers, and mechanics, 
and end it as lawyers, physicians, or clergymen, is quite 
limited, even in the United States, where every man has a 
better chance to follow the bent of his genius than in any 
other country. 
A comparison, therefore, of the longevity of the profes- 
sional and of the muscle-working classes, as derived from 
Registration Reports, such as I have made, is quite justifi- 
able. The value of this comparison would be vitiated if it 
could be proved that those who enter the professions are 
originally healthier and stronger, and come from better stock, 
than those who enter physical avocations; but in this coun- 
try the practice has been to allow the more delicate members 
of a family to enter a profession, whilst the tough and hardy 
work on the farm or learn a trade, Here, asin Europe, 
there is growing up a distin¢tively intellectual class who live 
solely by brain-work; it is, however, not from this class alone, 
