It may no doubt appear very enticing to the lovers of such things, to
hear of the gorgeous colors and prodigious size of butterflies, moths
and beetles; the varieties of reptiles, the flying foxes, the gigantic
crocodiles; the countless species of waterfowl, et hoc genus omne; but
one very serious fact is apt to escape the observation of the general
reader, that wherever insect and reptile life is most abundant, so sure
is that locality full of malaria and disease.

Ceylon does not descend to second-class diseases: there is no such
thing as influenza; whooping-cough, measles, scarlatina, etc., are
rarely, if ever, heard of; we ring the changes upon four first-class
ailments--four scourges, which alternately ascend to the throne of
pestilence and annually reduce the circle of our friends--cholera,
dysentery, small-pox and fever. This year (1854) there has been some
dispute as to the routine of succession; they have accordingly all
raged at one time.

The cause of infection in disease has long been a subject of
controversy among medical men, but there can be little doubt that,
whatever is the origin of the disease, the same is the element of
infection. The question is, therefore, reduced to the prime cause of
the disease itself.

A theory that animalcules are the cause of the various contagious and
infectious disorders has created much discussion; and although this
opinion is not generally entertained by the faculty, the idea is so
feasible, and so many rational arguments can be brought forward in its
support, that I cannot help touching upon a topic so generally
interesting.

In the first place, nearly all infectious diseases predominate in
localities which are hot, damp, swampy, abounding in stagnant pools and
excluded from a free circulation of air. In a tropical country, a
residence in such a situation would be certain death to a human being,
but the same locality will be found to swarm with insects and reptiles
of all classes.

Thus, what is inimical to human life is propitious to the insect tribe.
This is the first step in favor of the argument. Therefore, whatever
shall tend to increase the insect life must in an inverse ratio war
with human existence.

When we examine a drop of impure water, and discover by the microscope
the thousands of living beings which not only are invisible to the
naked eye, but some of whom are barely discoverable even by the
strongest magnifying power, it certainly leads to the