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Office of the Metropolitan Board of Health,
No. 301 Mott Street,
New York, August 26th, 1867.
Friend Leeds.
Your Lectures on Ventilation have given me much pleasure, and
have renewed my confidence in the utility of popular instruction
upon the subject. I heartily thank you for the thoughtful care
with which you have set forth all the essential principles of
ventilation, in language so free from technical words, and so full
of plain and homely illustration, that even an uneducated reader
can fully understand all you have written. The good Dr. D. Boswell
Reid, Dr. Wyman and myself had each attempted to use such a style
of explanation and instruction; but you have far excelled us all.
The first want of every living being is fresh air, and unless the
human lungs are supplied with such air constantly at the rate of
from ten to thirty cubic feet every minute, by night as well as
by day, perfect health and vigor cannot be preserved. Then, too,
there are exhaled from the surface of the body and from the lungs,
such quantities of waste organic matter, which tend to immediate
putridity, that it, together with the carbonic acid, would keep
the human body immersed in a deadly vapor of these exhalations,
were not fresh air supplied. The illustrations by which you have
made these truths easily understood, are admirably given in your
lectures, and the method, by which you would best insure success
in removing the foul and supplying the pure fresh air in every
place where persons live or sleep, are, as I believe, from my own
careful studies of this subject, most correct and trustworthy.
Indeed, I am able to say that, in my examinations of the vast
number of hospitals and buildings which you ventilated during
the late war, under authority from the intelligent and humane
Quartermaster-General of the army, the proof of entire success
in your work was everywhere witnessed. Simplicity, invariable
certainty and a liberal sufficiency characterizes these admirable
methods of yours.