After having practiced medicine for fifteen years, except the months I was
absent at Cleveland the last six years of the time, I was invited to fill
the chair of Theory and Practice in the New York Homoeopathic Medical
College. This invitation I accepted, and removed to New York and took up my
residence there, and commenced practice again in a new field. About the
year 1868 I invented a new process for refining petroleum by the aid of
superheated steam, and spent eighteen months in developing the process at
Binghamton, N. Y., and then returned to my practice in New York City. In
the year 1873 I gave up the practice of medicine, and in connection with
two gentlemen who were interested in selling oils, I commenced the refining
of petroleum, manufacturing therefrom machinery and other oils; to which
business I have devoted my attention ever since. I have attended chiefly to
the manufacturing department and my partners to the selling.

I have been frequently asked: "Why did you quit the practice of medicine?
Was not that a useful business?" Yes, it was; but I had come to feel that
there were fields for greater usefulness--in fact, that it was vastly more
important to teach people the laws of health and life, and to strive to
lead them by precept and example to shun the causes of disease, than it was
to cure them when they were sick--that prevention was better than cure.
Consequently, when I saw before me a reasonably sure prospect of being able
to make a good deal more money at the refining business than I could ever
expect to make in the practice of medicine, I could but feel that, by the
aid of a reasonable portion of the money thus made, I could perform a far
greater use than I could by practicing medicine. This, then, was the reason
for my giving up a good and useful profession and practice for my present
business. What I have attempted to do for the benefit of suffering humanity
since I gave up the practice of medicine, I will name in a future chapter.