Buffon's Natural History. Volume 04 (of 10) / Containing a Theory of the Earth, a General History of Man, of the Brute Creation, and of Vegetables, Minerals, &c. &c

by comte de Georges Louis Leclerc Buffon

Having already traced the causes of the formation, growth, and expansion of the human frame, we shall now proceed to consider those of its decay.

At first the bones of the fœtus are only small threads, of a ductile matter, and of little more substance than the flesh; by degrees they acquire solidity, and may be considered as a kind of small tubes, lined both within and without by a thin membrane which supplies the osseous matter. A pretty exact idea might be formed of the growth of bones, by comparing them with the manner in which the wood and solid parts of vegetables are produced. These bones, or, as we have said, tubes, are covered at both ends by a soft substance, and in proportion as they receive nutritious juices, the extremities extend from the middle point which always preserves its original station. The ossification begins at the middle and gradually follows the extension until the whole is converted into bone. Having acquired their full growth, and the nutritious juices no longer being necessary for their augmentation, they serve the purpose of increasing their solidity; in time the bones become so solid as not to admit the circulation of these juices which are highly essential to their nourishment; and this being stopped, they undergo a change like that perceived in old trees; and this change is the first cause that renders the decay of the human body inevitable.

The cartilages, which may be considered as soft and imperfect bones, grow also more rigid as we increase in years; and as they are generally placed near the joints, the motion of these must of consequence become more difficult. Thus, in old age, every action of the body is performed with labour; and the cartilages, which in youth were elastic, and in manhood pliant, will now sooner break than bend, and may be considered as the second cause of our dissolution.

The membranes become likewise as we grow old more dense and more dry. Those, for example, which surround the bones cease to be ductile, and are incapable of extension so early as the age of 18 or 20. It is also the same with the muscular fibres, and though to the external touch the body seems, as we advance in years, to grow more soft, yet in reality it is increasing in hardness. On such occasions it is the skin, and not the flesh, that communicates this perception. The fat which increases when the body is arrived at maturity, being interspersed between the skin and muscles, gives an appearance of softness which the flesh is far from possessing in reality; an undeniable proof of which is to be found in comparing the flesh of young and old animals; the former is tender and delicate; the latter hard, dry, and unfit for eating.

While the body increases, the skin will stretch to any degree of tension; but when the former diminishes, the latter never contracts; and hence the source of wrinkles, which cannot be prevented. Those of the face proceed from this cause, though as to shape they depend in a greater measure on its form, features, and habitual movements. By examining the countenance of a man at the age of 25 or 30, we may discover in it the origin of all the wrinkles it will have in old age; particularly when the features are in a state of agitation by laughing, weepings or any strong grimace. All the little furrows formed by these agitations will one day become wrinkles, which no art shall be able to remove.

In proportion then as we advance in years, the bones, the cartilages, the membranes, the flesh, the skin, and all the fibres of the body grow more solid, hard, and dry. Every part shrinks, and every motion becomes more slow; the circulation of the fluids is performed with less freedom, the perspiration diminishes, the secretions alter, the digestion becomes slow and laborious, the nutritive juices become less plentiful, and no longer serving to convey their accustomed nourishment, are wholly useless, as if they did not exist. Thus the body dies by little and little, all its functions diminish by degrees, and death only at last seizes upon that little which is left.

As the bones, the cartilages, the muscles, and all the other parts of the body, are naturally softer in women than in men, they do not acquire so soon that hardness which hastens death. Women, therefore, ought to live longer than men. This is actually the case; for by consulting the tables which have been formed respecting the duration of human life, we shall find that, after a certain age, women have a greater chance for long life than men of the same number of years. From this it may also be inferred, that such men as are weak in appearance, and whose constitution rather resembles that of women, have a probability of living longer than those who seem to be more strong and robust; as likewise, that in either sex such persons as have been slow in their advances to maturity, will be slow in their advances to the infirmities of old age, because in both cases, the bones, the cartilages, and all the fibres, require a longer time to arrive at that degree of solidity, which must be the foundation of their destruction. This natural cause of death is common to all animals, and even to vegetables. An oak only perishes because its more ancient parts, which are in the centre, become so hard and so compact, that they can no longer receive any nourishment; and the moisture they contain, being deprived of circulation, becomes corrupted, and gradually alters the fibres of the wood, which become red, and at length crumble into dust.

The duration of life may be determined, in some measure, by the time that was employed in the attainment of maturity. A tree, or an animal, which takes but a short time to finish its growth, perishes much sooner than those which are longer in coming to maturity. Neither animals nor plants begin to spread in bulk till they have acquired their summit of height. Man grows in stature till the age of 17 or 18; but his body is not completely unfolded in all its parts till that of 30; while a dog is at its full length in one year, and at its full thickness in another. The man whose growth is so tedious, lives for 90 or an 100 years; whereas the dog seldom survives its 10 or 12th year. To the generality of other animals this observation is equally applicable. Fishes, whose growth continues for a number of years, live for centuries; and this from no other known certain cause, but the particular constitution of their bones, which do not admit of the same solidity as the bones of terrestrial animals.

Whether there are any exceptions to this kind of rule, which Nature seems to have adopted in proportioning the duration of life to that of the bodily growth, we shall enquire when we come to the particular history of animals, as also whether crows and stags live for such a number of years as is commonly pretended. In the mean while, as a general truth, let it be remarked, that large animals live longer than small ones, and this because they require a longer time to come to maturity.

The causes of our decay then are inevitable; nor can we avoid the fatal arrow of death, or even avert it, without changing the laws of Nature. The ideas which a few visionaries have formed of perpetuating life by some particular panacea, as that of the transfusion of the blood of one living creature into the body of another, must have died with themselves, did not self-love constantly cherish our credulity, even to the persuasion of some things which are in themselves impossible, and to the doubt of others, of which every day there are demonstrative proofs.