The want of any essential organ in generation wholly changes the peculiar sexual form. This we know, by frequent experience among animals, and it occurs in the human race. We had lately a record of this kind, where a woman experienced none of the changes which usually take place about the time of puberty; and it was, on dissection, found that the ovaries were wanting. When the form in either sex approaches to that of the other, there is generally some defect either external or internal, and sterility is often the consequence. Divorces on account of sterility are consequently justifiable in the eye of reason; though, from political views, they are countenanced in few of the more polished nations. Indeed, we have seen in the late distracted state of France, that the facility of procuring divorces occasioned the most infamous, disgraceful scenes.

Fertility is in proportion to the general health and the regular moral conduct of married people. The number of children, from one marriage, is computed in Iceland to be from fifteen to twenty; in Flanders from ten to twelve; in Germany eight, and England six to eight; in France from four to five; and in Spain from two to three . Women of a sanguine temperament, of a gay affectionate temper, are the most fruitful: those of a thin dry habit, of a warm eager temper, violently passionate; or, on the other hand, indolent, phlegmatic, and void of affection, less so. Nearly the same differences are observable in men. The end of the winter or the spring is most favourable to conception; for the greater number of births oceur in autumn or the early period of winter.

Maritime countries have been usually most prolific, it is said, on account of the fish diet. Cold and moist air are. supposed to be favourable to conception, while dry and hot countries are the opposite. Yet the negrcsses in Africa are reported to be prolific; but their constitution is peculiarly sanguine. The use of the baths in women, and the constant sitting on a horse in men, are said to be equally unfavourable to generation. Too great fatness or leanness, too violent passions, an exhausted constitution, intemperance, excess of venery, and unnatural indulgences, are equally causes of sterility. Women who have had many children are usually healthy and long lived: the single women affected with a variety of diseases. Women are more frequently barren than men impotent.

The various observations of travellers have shown that the multiplication of the human species proceeds more rapidly in cold, poor, less civilized countries, and probably in republics; while, on the contrary, a temperate climate, a high degree of civilization, with a moderately fertile soil, despotically governed, are less favourable to it; and it is still less rapid when these circumstances exist in a greater degree. In the first case the men are laborious and active; their manners simple: in the second, they arc ingenious and industrious; but, from a more sedentary and a more debilitating course of life, less vigorous and active. In warmer climates, and a more luxurious state of society, they are indolent, weak, and their powers in a great degree exhausted.

The lists of births in the different countries of Europe have shown, that villages and cities, where the population is numerous, and riches equally distributed, are more fertile than opulent cities; and that seasons of scarcity are injurious to population. Thus early Rome furnished numerous armies: under the emperors the armies were supplied by mercenaries. Russia and Sweden abound more in strong, active men, than Spain and Portugal. In Russia, it is said, the births are nearly one twelfth or one fifteenth of its population, and the deaths only about one in forty-five. Perhaps, if the whole of England be considered in one view, the deaths will not be more considerable; or, at most, will amount to one in forty.

The life of man is said, by the psalmist, to be threescore years and ten. Various are the instances in which, even in these times, it has been supposed to have extended beyond the hundredth year; but the greater number of these are fallacious: and, as we were once told by a woman whom we had detected in a fallacy in this respect, old age is a profitable profession. Many ages have been extended by vanity, some by the neglect of registers, or the mistake of persons; and, in general, we can scarcely rely on the accounts of any who are said to have exceeded a century. Prior to the deluge the age of man seems to have been more considerable; but the great object of the Mosaic narrative seems to have been the preservation of the genealogy of the children of Israel from Adam, and we may reasonably conclude that, in continuing this succession, families or dynasties may have been represented as individuals. No change in the constitution of the globe, in the lives or situations of inferior animals, are recorded: we have no reason to suppose that the descendants of Noah were in any respect different from his parents. In these times we are told by Buffon that one fourth of those who are born die before the end of five years; one third before the age of ten; half before they have completed the thirty-fifth year; two thirds before the fifty-second; three fourths before the sixty-first. He adds, that the mean life of a child of three years is thirty-three years; that of a man of twenty-one is nearly the same. The life of a man of sixty-six is nearly of the same value with that of an infant just born. Many other observations of this kind might be suggested, if it were a proper subject of this work; but, in general, the probabilities of human life are taken 'from the records of great cities, where life is much more precarious than in the country. The insurers and the calculators of tontines and benefit societies have fatally experienced the fallacy of such statements, when their members are promiscuously taken from large cities, towns, villages, and the country. The lives of women are said to be shorter than those of men, and of single women than of single men.