tant to
ascertain what localities will be the least likely to generate disease,
and to affect the sanitary condition of men occupying them.

This subject has been thoroughly examined by Dr. Robert Johnson,
Inspector General of Hospitals in the English army in 1845; and, as his
conclusions are deduced from enlarged experience and extended research,
they should have great weight. I shall therefore make no apology for
introducing here a few extracts from his interesting report touching
upon this subject:

"It is consonant with the experience of military people, in all ages
and in all countries, that camp diseases most abound near the muddy
banks of large rivers, near swamps and ponds, and on grounds which have
been recently stripped of their woods. The fact is precise, but it has
been set aside to make way for an opinion. It was assumed, about half a
century since, by a celebrated army physician, that camp diseases
originated from causes of putrefaction, and that putrefaction is
connected radically with a stagnant condition of the air.

"As streams of air usually proceed along rivers with more certainty and
force than in other places, and as there is evidently a more certain
movement of air, that is, more wind on open grounds than among woods
and thickets, this sole consideration, without any regard to
experience, influenced opinion, gave currency to the destructive maxim
that the banks of rivers, open grounds, and exposed heights are the
most eligible situations for the encampment of troops. They are the
best ventilated; they must, if the theory be true, be the most healthy.

"The fact is the reverse; but, demonstrative as the fact may be,
fashion has more influence than multiplied examples of fact
experimentally proved. Encampments are still formed in the vicinity of
swamps, or on grounds which are newly cleared of their woods, in
obedience to theory, and contrary to fact.

"It is prudent, as now said, in _selecting ground for encampment_, to
avoid the immediate vicinity of swamps and rivers. The air is there
noxious; but, as its influence thence originating does not extend
beyond a certain limit, it is a matter of some importance to ascertain
to what distance it does extend; because, if circumstances do not
permit that the encampment be removed out of its reach, prudence
directs that remedies be applied to weaken the force of its pernicious
impressions.

"The remedies consist in the interposition of rising ground