From these it appears, that in every particular place there is an invariable law which governs the waste of human life. In single years, owing to the seasons, to the absence or prevalence of epidemics, or other accidental circumstances, the quantity of disease may vary, and the number of deaths be less or greater. But taking the average of a series of years together, the same total numbers have been found to die in the same situations, in the equal successive periods of time. These facts are established by observations taken from the bills of London, of Northampton, of Norwich, in England, and of many other places in various parts of Europe. In situations moderately healthy, as in moderate-sized towns, the rates of decrease have been found to coincide very nearly with the hypothesis of Mr. de Moivre, who, assuming 86 years to be the utmost extent of life, supposed an equal decrement of life through all its stages, till it was finally extinguished. For example, of 56 persons alive at 30 years of age, one will die every year till, in 56 years, they will be all dead. The same will happen to 46 persons at 40, in 46 years, and so on, for all other ages. At most ages between 30 and 70 or 75, the results of this hypothesis are very nearly conformable to actual observations. But both in the earlier and in the later stages of life, the law of decrease is very different. In London also, and in large cities, in general the current of life flows with greater rapidity. In the country, on the other hand, communities are more healthy, and, in consequence, life is expended more slowly.

As life at all ages wastes according to invariable laws, so likewise does it at a given age. In consequence, the expectation of life either at birth, or at any given age, that is to say, the mean continuance of any given, single, joint, or surviving lives, may, from tables properly constructed, be calculated with mathematical certainty.

The proportions between the whole numbers living at any age and upward, and the whole number of the community, is a fixed proportion. This fact is established by observation, and is indeed a consequence of the invariable laws according to which human life is expended.

From these documents the havoc made in human life, by collecting multitudes of men together in great cities, is fully demonstrated. There is no stage of life in which this pernicious influence is not evident, but it is most remarkable in the earliest stages. In London, according to the most moderate computation, half the number born die under three years of age; in Vienna and Stockholm, under two. And other things

being equal, the insalubrity of towns appears to be in proportion to their size.

The proportion of persons who die annually in great towns, is found to be one nineteenth or one twentieth of the whole population. In moderate towns, it is from one twenty-third to one twenty-eighth. In the country, the proportion has been found to be from one thirty-fifth or one fortieth to one fiftieth or one sixtieth. In London, the number of years which a child at birth has been found, upon an average, to reach, is rather less than twenty. In Norwich, half die under five years; in Northampton, under ten. In the parish of Holy Cross, near Salop, the expectation of a child at birth is thirty-three years: one half the inhabitants live to thirty years of age. At Ackworth, in Yorkshire, half the inhabitants live to the age of fortysix. In the town of Manchester, one twenty-eighth part of the inhabitants die annually; in the country, in its immediate vicinity, the number is not more than one fifty-sixth part.

Large cities are as unfavorable to longevity as they are destructive of infant life, and unfriendly to health at every period. In country places it is the reverse. At Holy Cross, one in eleven and a half of the whole population die at upward of eighty years of age. At Ackworth, one fourteenth of the inhabitants reach the same age. At Northampton, the proportion is one twentysecond part; at Norwich, one twenty-seventh. But in London only one in forty arrives at this age; whereas, if other things were equal, the proportion in London ought to be greater than in other places, since at least one fourth of its inhabitants are persons who come into London from the country, in the most robust period of life, at which the probability of living to old age is the greatest. Of the natives of London, not more than one in sixty attains the age of four-score.

Though villages and country places are more healthy than towns, and that in a degree to excite astonishment in those who are imperfectly acquainted with the facts, yet there is a great diversity in the healthiness of different villages and country places. This demonstrates and exemplifies the important influence of locality in the production of disease, and on the length of human life. Marshy situations, conformably to what has been already said of their general insalubrity, are the most unfavorable to the health, insomuch that they are as destructive of life as large cities. Dr. Price has, in the following paragraph, strikingly contrasted the different salubrity of different parishes in the small district of Vaud, in the county of Berne.

In

"One half of all born in the mountains live to the age of 47. In the marshy parish, one half live only to the age of 25. the hills, 1 in 20 of all that are born live to 80. In the marshy parish, only 1 in 52 reaches this age. In the hills, a person aged 40 has a chance of 80 to 1 for living a year. In the marshy parish, his chance of living a year is not 30 to 1. In the hills, persons aged 20, 30, and 40, have an even chance for living 41, 33, and 25 years, respectively. In the fenny parish, persons at those ages have an even chance of living only 30, 23, and 15 years."

The

average mortality of England and Wales is calculated, in the year 1810, to be 1 in 49. In the parts subject to the ague, Kent, Essex, Cambridgeshire, and the East Riding of Yorkshire, the mortality is above this average. At Boston, in the fens of Lincolnshire, the mortality is 1 in 27. At Stamford, which is in the dry and upland division of the same county, it is only 1 in 50.

The duration of human life, then, is regulated by fixed and invariable laws. Nor does it at all affect the general deductions drawn from these facts, though the observations on which they are founded should not be correctly applicable to the present state of things. It is thought, and probably with reason, that the healthiness both of this empire and of the metropolis is improved since the time when Dr. Price published his observations. Dr. Heberden, the younger, estimates the present rate of mortality in London to be 1 in 30 nearly; a prodigious improvement if it be just! But it has been always found that the external circumstances of society remaining unchanged, the rate of mortality is uniform; and when this rate has been found to undergo any considerable and permanent alteration, it may be traced to some corresponding change in these circumstances. The extension of agriculture; draining and enclosure of wastes; cleansing of towns; ventilation of private houses; improvements in diet and clothing; such, in general, are the sources of improved health and prolonged life. I suspect myself that the increased cultivation of the potato, and its very general use among the laboring classes of London, has, more than any other single cause, contributed to the improved health of the metropolis.*

A fact related by Mr. Malthus, with regard to the town of Geneva, proves how great a change has really taken place in

* I have heard it suggested, not perhaps without reason, that the substitution of cotton for woolen clothing has been the cause of the disappearance in so great a degree, of late years, of the low contagious or typhus fever.

the same spot, and at no very distant period of time. In this town, in the sixteenth century, the probability of life, or the age to which half the born lived, was only 4.883—rather less than four years and nine tenths; and the mean life 18.511about eighteen years and a half. In the seventeenth century the probability of life was 11.607-above eleven years and a half; the mean life 23.358. In the eighteenth century the probability of life had increased to 27.183-twenty-seven years and nearly a fifth; and the mean life to thirty-two years and a fifth.

The conclusions which forced themselves upon the mind of the enlightened and respectable writer who has principally furnished me with these materials, I cannot refrain from giving in his own language: "Death," says Mr. Price, "is an evil to which the order of Providence has subjected every inhabitant of this earth; but to men it has been rendered unspeakably more an evil than it was designed to be. The greatest part of that black catalogue of diseases which ravage human life, is the offspring of the tenderness, the luxury, and the corruptions introduced by the vices and false refinements of civil society. That delicacy which is injured by every breath of air, and that rottenness of constitution which is the effect of indolence, intemperance, and debauchery, was never intended by the Author of nature; and it is impossible that they should not lay the foundation of numberless sufferings, and terminate in premature and miserable deaths." To the same purpose, says another writer who is very competent to form a correct opinion, when his judgment is not warped by a favorite hypothesis: "Diseases have been generally considered as the inevitable inflictions of Providence; but perhaps the greater part of them may more justly be considered as indications that we have offended against some of the laws of nature." When persons of enlarged minds, and who are unfettered by professional prejudices, arrive at the same conclusions, it affords no weak presumption that they are justly formed.

These intelligent writers, then, have concluded that our discases are, for the most part, artificial. But we must not confine ourselves to vague and barren generalities. It is essential to view the subject still more closely, and attend more exactly to the consequences which flow irresistibly from the data which have been established. This is the more necessary as there are, I think, many incorrect notions afloat on these subjects, and many who are acquainted with the facts do not appear impressed with their proper consequences.