sufficient authority; thirdly, because they are not
sufficiently numerous. But, in this case, the disease is one of striking
and well-marked character; the witnesses are experts, interested in
denying and disbelieving the facts; the number of consecutive cases in
many instances frightful, and the number of series of cases such that I
have no room for many of them except by mere reference.

X. These results of observation, being admitted, may, we will suppose,
be interpreted in different methods. Thus the coincidences may be
considered the effect of chance. I have had the chances calculated by
a competent person, that a given practitioner, A., shall have sixteen
fatal cases in a month, on the following data: A. to average attendance
upon two hundred 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