repeated by ignorant people _without_ the latter
clause; or there is no possibility of the conditions of the latter
clause being obtained; and this, the _only_ essential part of the whole,
is made of no effect. I have heard a physician, deservedly eminent,
assure the friends of a patient of his recovery. Why? Because he had now
prescribed a course, every detail of which the patient had followed for
years. And because he had forbidden a course which the patient could not
by any possibility alter.[38]

Undoubtedly a person of no scientific knowledge whatever but of
observation and experience in these kinds of conditions, will be able to
arrive at a much truer guess as to the probable duration of life of
members of a family or inmates of a house, than the most scientific
physician to whom the same persons are brought to have their pulse felt;
no enquiry being made into their conditions.

In Life Insurance and such like societies, were they instead of having
the persons examined by a medical man, to have the houses, conditions,
ways of life, of these persons examined, at how much truer results would
they arrive! W. Smith appears a fine hale man, but it might be known
that the next cholera epidemic he runs a bad chance. Mr. and Mrs. J. are
a strong healthy couple, but it might be known that they live in such a
house, in such a part of London, so near the river that they will kill
four-fifths of their children; which of the children will be the ones to
survive might also be known.

[Sidenote: "Average rate of mortality" tells us only that so many per
cent. will die. Observation must tell us _which_ in the hundred they
will be who will die.]

Averages again seduce us away from minute observation. "Average
mortalities" merely tell that so many per cent. die in this town and so
many in that, per annum. But whether A or B will be among these, the
"average rate" of course does not tell. We know, say, that from 22 to 24
per 1,000 will die in London next year. But minute enquiries into
conditions enable us to know that in such a district, nay, in such a
street,--or even on one side of that street, in such a particular house,
or even on one floor of that particular house, will be the excess of
mortality, that is, the person will die who ought not to have died
before old age.

Now, would it not very materially alter the opinion of whoever were
endeavouring to form one, if he knew that from that floor, of that
house, of that stre