This investigation may appear idle; yet, in a physiological point of view, it is fraught with interest as regarding the generation of animals and plants. Its study affords a lively illustration of those laws of attraction and repulsion that regulate the universe, and which seem to admit that every particle of matter should be endowed with a specific vitality, a specific individuality. This attraction is daily seen in the fecundation of the spawn of fish. Myriads of these eggs are accumulated in ponds and rivers; yet in this mass the fecundating principle solely selects and impregnates those that naturally claim its vivifying powers. Wonderful harmony, that man alone endeavours to destroy!—harmony so perfect, that Aristoxenus and Alcmæon maintained that it was an emanation of the diapason of celestial music between the planets, our globe, and our five senses, forming a diatonic series of seven tones; while Hippocrates justly denominated these organic laws the CONFLUXUS UNUS, CONSPIRATIO UNICA, CONSENTIENTIA OMNIA.
LONGEVITY.
The greater the complexity of a piece of machinery, and the more labour it is called upon to perform, the more rapid will be its wear and tear. This applies to human life as well as to mechanism. The derangement of its component parts—its springs and wheels, will also be in the ratio of their complication. Thus do we find that the brute creation are less subject to those affections that abridge their days than mankind. Their life is natural, except when under the sway of domestication: ours is artificial; and high civilization tends to render it still more unnatural than it would most probably have been in a simple and patriarchal existence. Endowed with more acuteness of sensibility than animals, we are rendered more susceptible of the extremes of pleasure and of pain; and our voluptuous enjoyments are perhaps more prejudicial than our sufferings. Had not the Creator wisely granted us the faculty of reasoning, we should have been the most wretched of all organized beings.
The tenure of life depends upon the sum of vitality originally deposited, and the extent of our drafts upon this capital, which we too frequently exhaust by untimely expenses. Experience has proved that under ordinary circumstances, man can live six or seven times longer than the years required to attain puberty. This epoch is placed at our fourteenth year. This calculation would therefore yield from 84 to 98 years of age. Our own imprudences, and the disorders resulting from them, are more hostile in abridging this period than nature, all-wise and all-bountiful. Indeed, when we reflect on all the excesses to which we expose our frail and complicated being, as if we were resolved to try by every possible experiment how far it possesses the power of resisting destructive agents, we can only marvel in beholding so many instances of longevity. In this wasteful existence how many valuable hours do we not lose? how many real enjoyments have we not deprived ourselves of? When compared to the immensity of time, life is but an idle span. Let us deduct even from old age the years of infancy, the years of caducity, and the years of sleep,—alas! what remaineth of our many and our energetic days? Maupertuis calculated that in an ordinary life man could scarcely enjoy more than three years of happiness, mixed up with sixty or eighty years of misery or insipidity; and yet how miserable are we at the thought of quitting this short-leased tenement, though every wretchedness renders our abode a constant scene of uneasiness. It has been computed that out of about nine hundred millions of human beings that are scattered over the globe, it is more than probable that we could not find nine thousand individuals blessed with happiness, even taking happiness in its most limited sense—content. Were it not for the terrors of futurity, it is more than probable that our existence would lose much of its value. Socrates termed philosophy “the preparation for death;” the same may be said of our existence.
Happily for man, life is a dream, all is illusion; sufferings alone are positive; Pandora’s box is its best illustration. Could we have slept away our existence in constant visions, we should have lived as long as in a waking state. When we contemplate the flocks of human beings scattered like cattle on the face of the universe, with scarcely more intellect than the beasts of the same field, we might ask for what were they created? doomed to all the horrors of sickness or of war, victims of their own follies or the ambitious projects of others! As far as regards this life, it is worse than idle to seek a solution of the problem. In these inquiries we too often seek to guess that which we can never know, and to know that which we can never guess! We all complain and murmur like the woodman in the fable, yet are loath to accept the relief we loudly call for.
The longevity of the first races, and the patriarchs, are records foreign to the investigations of natural history; we must seek for more recent examples. Haller had collected the cases of many centenaries, amounting to sixty-two who had reached from 100 to 120; twenty-nine from 120 to 130; and fifteen from 130 to 140. Few instances are authenticated beyond this period: yet we find one Eccleston, who lived 143 years; John Effingham, who attained his 144th; a Norwegian, who counted a century and a half; and our Thomas Parr would most probably have passed his 152nd year but for an excess. Henry Jenkins lived to 169; and we have on record the case of a Negress, aged 175. The Hungarian family of John Rovin were remarkable for their longevity: the father lived to 172, the wife to 164; they had been married 142 years, and their youngest child was 115; and such was the influence of habit and filial affection, that this child was treated with all the severity of paternal rigidity, and did not dare to act without his papa’s and mamma’s permission.
By the calculations of Sussmilch, out of one thousand individuals, only one attained 97; and not more than one lived to the age of 100, out of one hundred and fourteen thousand. In the census of Italy, taken under Vespasian, there were found fifty-four of 100, fifty-seven of 110, two of 125, four of 130, and three of 140. In China, under Kien Long, in 1784, there were only four individuals who had attained their 100th year. According to Larrey, there were at Cairo thirty-five persons who had exceeded their century. In Russia, in 1814, out of eight hundred and ninety-one thousand six hundred and fifty deaths, were three thousand five hundred and thirty-one from 100 to 132. In a register of deaths in Paris, taken in 1817, there were found in twenty-one thousand three hundred and ninety-two, nine from 95 to 100, and the general proportion of centenaries in that city is one to three thousand.
What are the circumstances most favourable to longevity? This question is not easily answered; for we find in instances of advanced age that some individuals have led a most regular and abstemious life, while others have indulged in various excesses. These observations, however, are by no means calculated to form a conclusive opinion, as the constitutional vigour and peculiar idiosyncrasies of individuals differ widely. It is probable that a regular mode of living is the most likely to prolong our years, whatever may be that regularity in a comparative point of view. A sober man, who commits occasional excesses, is more likely to suffer than another man who gets drunk every night, provided that these excesses do not differ in regard to the quantity or quality of stimulus. In these melancholy instances the excitement is constant, and the indirect debility which it may produce has scarcely time to break down the system ere it is again wound up to its usual pitch, to use the vulgar expression, “by a hair of the same hound.” The principal attribute of life that renovates for a while its moral and its physical exhaustion is excitability, and a constant excitement is therefore indispensable, to serve as fuel to the consuming fire. This was to a certain degree the basis on which Brown founded his doctrine. He traced a scale of life like that of a thermometer,—health in the centre, death at each extremity: one scale ascending from health was graduated according to stimulating agency, the other to debilitating causes; and therefore the system was to be stimulated or lowered according to this gradation. It would be foreign to this work to point out the absurdity of this theory, although we must admit its ingenuity, and to a certain extent its correctness. The chief practical objection to it was the diversity of constitutions and idiosyncrasies, and the different action of stimulating or depressing agents in health and in disease; the effects of alimentary and medicinal substances being totally different in these several conditions.