and there among British
officers: so I do not expect you to become such geologists as Sir
Roderick Murchison, or even to add such a grand chapter to the history of
extinct animals as Major Cautley did by his discoveries in the Sewalik
Hills. Nevertheless, you can learn--and I should earnestly advise you to
learn--geology and mineralogy enough to be of great use to you in your
profession, and of use, too, should you relinquish your profession
hereafter. It must be profitable for any man, and specially for you, to
know how and where to find good limestone, building stone, road metal; it
must be good to be able to distinguish ores and mineral products; it must
be good to know--as a geologist will usually know, even in a country
which he sees for the first time--where water is likely to be found, and
at what probable depth; it must be good to know whether the water is fit
for drinking or not, whether it is unwholesome or merely muddy; it must
be good to know what spots are likely to be healthy, and what unhealthy,
for encamping. The two last questions depend, doubtless, on
meteorological as well as geological accidents: but the answers to them
will be most surely found out by the scientific man, because the facts
connected with them are, like all other facts, determined by natural
laws. After what one has heard, in past years, of barracks built in
spots plainly pestilential; of soldiers encamped in ruined cities,
reeking with the dirt and poison of centuries; of--but it is not my place
to find fault; all I will say is, that the wise and humane officer, when
once his eyes are opened to the practical value of physical science, will
surely try to acquaint himself somewhat with those laws of drainage and
of climate, geological, meteorological, chemical, which influence, often
with terrible suddenness and fury, the health of whole armies. He will
not find it beyond his province to ascertain the amount and period of
rainfalls, the maxima of heat and of cold which his troops may have to
endure, and many another point on which their health and efficiency--nay,
their very life may depend, but which are now too exclusively delegated
to the doctor, to whose province they do not really belong. For cure, I
take the liberty of believing, is the duty of the medical officer;
prevention, that of the military.

Thus much I can say just now--and there is much more to be said--on the
practical uses of the study of Natural History. But l