PRACTICAL RELATIONS OF SCIENCE. 
119 
period. And without indulging in over sanguine expectations, 
it may be inferred that, with some care and attention, it may 
be very materially prolonged. Even the statistics of Insurance 
Companies prove that the expectation of life has been very 
materially prolonged by improvements in cities and villages. 
A right appreciation of this question is then an object of the 
highest interest, and lies at the root of the right disposition of 
time devoted to educution, business and relaxation. 
In the North American States, at least on the Atlantic 
coast, the nervous system is perhaps more unduly stimulated 
than in many other countries, and the effects are manifest in 
all the varied relations of life. There may be much energy 
and activity, but it is accompanied by a corresponding anxiety, 
and wear and tear of the constitution. A less severe drain on 
the nervous system, w’ould, it is firmly believed, be accompanied 
with more happiness and a greater length of life. The com¬ 
pensating elements which the United States presents in other 
respects, enables it to compare favorably with many European 
States. But it is altogether a mistake to suppose that because 
population is less dense, sanitary improvements do not demand 
special attention. New York has its victims, as well as London, 
from defective architecture and sanitary measures. The Na¬ 
tional disease at Washington, where the suffering was so great 
that seven hundred individuals were injured there, was caused 
by bad drainage, and a year previous to the outbreak, the 
necessity of sanitary measures was strongly urged on the 
managers. A special cause is considered to have developed a 
peculiar aggravation, and infused arsenic both into the air and 
into the water. 
Very favorable reports are given of the general condition of 
health on both banks of the upper district of the Mississippi. 
But that is no reason why we should not study existing evils 
that may arise in any State, or in any locality where the pri¬ 
mary laws of health are either neglected or not sufficiently 
understood throughout the population. I cannot refer to any 
state or nation that I have visited either on this or the other 
side of the Atlantic, where there is not a great necessity for 
