But with the great majority of cases, there is nothing of the kind; and the power of forming any correct opinion as to the result must entirely depend upon an enquiry into all the conditions in which the patient lives.  In a complicated state of society in large towns, death, as every one of great experience knows, is far less often produced by any one organic disease than by some illness, after many other diseases, producing just the sum of exhaustion necessary for death.  There is nothing so absurd, nothing so misleading as the verdict one so often hears:  So-and-so has no organic disease,—­there is no reason why he should not live to extreme old age; sometimes the clause is added, sometimes not:  Provided he has quiet, good food, good air, &c., &c., &c.:  the verdict is 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.[6]

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 person examined by the 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.