It results from this table, that during each successive period, there has been an augmentation in the total number of the population, a diminution in the proportion of deaths as compared with the population, a corresponding diminution in the proportion of births, and an augmentation in the proportion of marriages, coupled with a decrease in the ratio of births to a marriage. The fecundity of marriages has diminished one fourth during the eighteenth century. An analogous result, though not to the same extent, has been observed in Paris from 1700 to 1790. M. Mallet's own researches during a more recent period, confirm the tendencies above exemplified.

It is not unimportant to observe, that, during the last ten years of this period, the number of divorces had diminished one fourth, as this circumstance might considerably affect the proportion of marriages. It should always be kept in mind that the fecundity of marriages may represent a very

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FECUNDITY OF THE POPULATION.

different result from the fecundity of the population. The fecundity of marriages, for instance, may decrease in a country where the mortality is great, owing to the increased proportion of marriages for the second or third time; yet the fecundity of the population itself may increase. Mr. Malthus, in his chapter on the Fruitfulness of Marriages, observes, that, with a given rate of increase, "it is clearly desirable to find in the registers a small rather than a large proportion of births to marriages, because the smaller this proportion is, the greater must be the proportion of the born which live to marry, and of course the more healthy must be the country."

The same records of the city of Geneva exhibit most satisfactory evidence of the increase both in the probable and the mean duration of life of the population during the last four centuries, as the following tables will show, which have been carefully examined and corrected, where necessary, by M. Mallet:

From M. Cramer's observations:

The excess of the probable life at present above the mean life, is a proof of the very great diminution of mortality amongst the young. With improved medical skill and greater care, the probable may be expected to exceed the mean duration of life; for though the feeble may be preserved to reach an adult state, they will, no doubt, die sooner than the strong.

M. Mallet, in discussing the probable causes of the diminished mortality amongst infants, states some facts in support of the beneficial effect of vaccination, which are worthy of attention. Mr. Finlaison, in his "Report on the Law of Mortality" amongst the government annuitants, seems to consider that the value of Dr. Jenner's discovery consists, not so much in the number of lives absolutely saved, as in the number preserved from comparative discomfort; and that the ravages of the smallpox before the introduction of vaccination have been over-estimated. "Variolous inoculation," he 66 says, was little known in general practice before the year 1750; and most people are aware that it never was universal, even among the more enlightened classes, from the natural aversion of parents to superin

duce voluntarily a loathsome disease, which the child very probably might escape altogether. Now it is an unquestionable fact that there is no perceptible difference at all in the mortality of children from the age of 3 to the age of 20 in the sixty years preceding 1805; that from the age of 3 to 12 the mortality regularly diminishes from about 12 in 1000 to 6, 5, and 4 in 1000; and from adolescence to maturity it rises again. Considering, therefore, the innumerable ailments to which children are liable, besides that of the smallpox, it is not in my power to believe that the smallpox in that period was so fatal a scourge as it is supposed to have been, unless indeed its whole severity fell upon infants under three years of age, and on the children of the poorer classes exclusively: because, with very great deference to better judges, I am unable to conceive a lower rate of mortality than 4 or 5 per annum in 1000, which was the case when the smallpox had full sway."

On the other hand, M. Mallet's researches during the four last centuries tend to show that whilst the mortality between the ages of 10 and 60 gradually decreases in each century, owing as he conceives to a gradual improvement in the domestic and social habits of life, accompanied with better food and clothing, more airy dwellings, and better medical and hygienic regula

tions, the mortality under ten years has decreased in a rapidly accelerated ratio during the present century since Dr. Jenner's discovery:

If we admit the conclusion at which Duvillard, in his investigations "Sur l'Influence de la Petite Verole," arrived, that 25 out of 26 cases of smallрох occurred amongst children between the ages of three and ten, to represent the general law, it will be seen from the above table, which forms a portion of a more complete one inserted in M. Mallet's memoir, that whilst the mortality between those ages decreased only one third from the 16th to the 18th centuries, it has diminished at a remarkably accelerated rate during the present century. The experience, indeed, of several physicians in particular localities has given some countenance to the idea, that the reduction of the mortality by smallpox is more than counterbalanced by the contemporaneous increase of deaths amongst children from other diseases, (Dr. Robert Watt's Observations on the Mortality amongst Children at Glasgow during 1703 -1812, in his Treatise on Chincough, 1813,) and that the smallpox itself may have been the