The age of man is estimated, as it was in the days of David, at _three score years and ten_—not more, however, than one in eighty reaches the tottering confines of mortality, and it has been correctly stated, that one half who come into life, leave it again before the expiration of their _eighth_ year; of a _thousand_ children born in London, _six hundred and fifty_ die before the age of _ten_. It has been computed by Herodotus, and acknowledged as correct by our ablest authors on political arithmetic, that three generations of men pass away in a century, and consequently the whole human species cannot be said to divide one with another more than _thirty-four_ years of existence. The astonishing longevity of the Antediluvians[261] has given rise to much discussion, but neither the researches of the learned, nor the reasonings of the ingenious, have hitherto thrown any light upon the subject; nor is the question of any importance in relation to the objects of the present work; the medical jurist is alone interested in the existing laws of mortality, and in those exceptions which may occur in their general dispensation. The several ages, or stages of man’s existence, have been differently determined, according to the particular views which have suggested the division, especially as they relate to legal or physiological objects; on the present occasion it is to the latter of these that we have more particularly to direct our attention. _Aristotle_ marked three grand and obvious divisions in our existence, that of GROWTH—that during which we remain apparently STATIONARY—and that of DECLINE; each of which has been subdivided by subsequent authors,[262] so as to constitute seven ages: thus the stage of Growth includes _Infancy_, _Second Infancy_, or _Boyhood_ (_Pueritia_) and _Adolescence_; the stage, during which we appear to remain stationary, consists of _Youth_ (_Juventus_) and _Manhood_ (_Ætas Virilis_). The last division—DECLINE, embraces _Old Age_, and _Decrepitude_. The philosophers and physicians of Greece were led to adopt several divisions corresponding with their superstitious reliance on the powers of certain numbers; _Varro_ divided life into five portions; _Solon_ into ten; but Hippocrates, Proclus, and the greater number of the ancient writers acknowledged SEVEN AGES, a division which has been very generally adopted by the poets and philosophers of later times; in proof of the opinion of the former, we may adduce the testimony of Hippocrates,[263] who says, εν ανθρωπου φυσει επτα εισιν ωραι, and in confirmation of the truth of our remark upon those of the latter, we may remind the reader of the celebrated passage in Shakspeare,[264] in which the progress of human life is so beautifully illustrated. The duration of each of these stages has moreover been considered as under the influence of the same mystical numbers, and will generally be found to be a multiple of _seven_, for