ing after suffering from
extreme cold, whether we perceive it or not at the time, is very apt to
produce deep and lasting injury to the brain and nervous system.

But my main object in relating the story is answered if I have succeeded
in clearly pointing out to the reader one of the avenues through which
light found its way to my benighted intellect, and led me to reflection
on the whole subject of health and disease. Here was obviously one cause
of a frequent but most painful complaint. It was natural, perfectly
natural, that by this time I should begin to inquire. Have all diseases,
then, their exciting causes? Many certainly have; and if many, perhaps
all. At least, how do we know but it may be so? And then again, if the
causes of chilblains are within our control, and this troublesome
disease might be prevented, or its severity mitigated if no more, why
may it not be so with all other diseases?

To revert for a moment to the case of Lydia Maynard. Though I was the
cause, in a certain sense, of her suffering, yet it was a sin of
ignorance. But it taught me much wisdom. It made me cautious ever
afterward. I do not doubt but I have been a means of preventing a very
considerable amount of suffering in this form, since that time, by
pointing out the road that leads to it.

Prevention is better than cure, was early my motto, and is so still. And
from the day in which I began to open my eyes on the world around me,
and to reason from effects up to their causes, I have been more and more
confirmed in the belief that mankind as a race are to be the artificers
of their own happiness or misery. All facts point in this direction,
some of them with great certainty. And facts, everywhere and always, are
stubborn things.

CHAPTER XIII.

HOW TO MAKE ERYSIPELAS.

My periodical tendency to a species of eruptive disease closely
resembling measles, was mentioned in Chapter IV. During the summer of
1823 this affection became unusually severe, and seemed almost beyond
endurance. The circumstances were as follows:--

I had in charge a large and difficult school. The weather was very hot,
and I was not accustomed to labor in summer within doors. Besides, my
task was so difficult as to call forth all the energies of body and mind
both; and the "wear and tear" of my system was unusually great. It was
in the very midst of these severe labors, in hot and not well-ventilated
air, that the eruption appeared. Perhaps it was aggra