ndred and fifty births in a year; three deaths in one thousand
births to be assumed as the average from puerperal fever; no epidemic to
be at the time prevailing. It follows, from the answer given me, that if
we suppose every one of the five hundred thousand annual births of
England to have been recorded during the last half-century, there would
not be one chance in a million million million millions that one such
series should be noted. No possible fractional error in this calculation
can render the chance a working probability. Applied to dozens of series
of various lengths, it is obviously an absurdity. Chance, therefore, is
out of the question as an explanation of the admitted coincidences.

XI. There is, therefore, some relation of cause and effect between the
physician's presence and the patient's disease.

XII. Until it is proved to what removable condition attaching to the
attendant the disease is owing, he is bound to stay away from his
patients so soon as he finds himself singled out to be tracked by the
disease. How long, and with what other precautions, I have suggested,
without dictating, at the close of my Essay. If the physician does not
at once act on any reasonable suspicion of his being the medium of
transfer, the families where he is engaged, if they are allowed to know
the facts, should decline his services for the time. His feelings on the
occasion, however interesting to himself, should not be even named in
this connection. A physician who talks about ceremony and gratitude, and
services rendered, and the treatment he got, surely forgets himself; it
is impossible that he should seriously think of these small matters where
there is even a question whether he may not carry disease, and death, and
bereavement into any one of "his families," as they are sometimes called.

I will now point out to the young student the mode in which he may
relieve his mind of any confusion, or possibly, if very young, any doubt,
which the perusal of Dr. Meigs's Sixth Letter may have raised in his
mind.

The most prominent ideas of the Letter are, first, that the transmissible
nature of puerperal fever appears improbable, and, secondly, that it
would be very inconvenient to the writer. Dr. Woodville, Physician to the
Small-Pox and Inoculation Hospital in London, found it improbable, and
exceedingly inconvenient to himself, that cow pox should prevent
small-pox; but Dr. Jenner took the liberty to prove the fact,
notwith