The commencement of spring and the end of autumn are supposed in Europe to be the most fatal seaons; but; Dr. Heberden has shown that in England a larger proportion of mankind die in the winter months.

It is probable that the cold in winter, so fatal to the weak and aged, may occasion the difference. When a thaw succeeds a severe and continued frost, deaths are more numerous, chiefly confined to the aged, and those labouring under chronic diseases of the lungs. In Asia there are two fatal periods, viz. the change of the seasons.

The ages most fatal are the changes of life, viz. the appearance of the teeth, the period of puberty, the period between twenty-one and twenty-eight, when the constitution has not yet attained its firmness; the time of the cessation of the menses in women; and the period when the generative faculty decays, or is lost, in man, about the age of sixty-three. On this foundation the ancients established their doctrine of climacterics; a system not wholly visionary, though refined too far, and mixed with numerous fancies.

Cold and dry countries are most favourable to the duration of life; and when moderately fertile, so as to require steady exertion, still more so. Some races and some families seem to have a peculiar claim to longevity, while the inhabitants of hot climates, who soon ripen, decay prematurely; and, in many families, we have known it a rare occurrence to find a person of the age of sixty. Those whose minds and bodies evolve slowly, are more often long lived than those who astonish by an early vigour and spirit; so that the usual axiom is not wholly without foundation - "so wise so young, will not live long." Hermogenes, Crichton, and Barra-tier, are instances of premature genius, with short lives. The early and astonishing acquisitions of very young men in different arts and sciences, also, seldom lead to acknowledged excellence in more advanced age. Sanguine temperaments are said to be longer lived than the bilious or melancholic; but this we suspect leans too much on a doubtful theory. Very tall or very short people seldom reach, it is said, to a great age; but a person rather short than tall, rather thin than fat, muscular, firm, and with a full chest, has apparently the fairest claim to longevity. An active life, with little uneasiness, a dry free air, early hours, a mind occasionally engaged, but not exhausted, a cheerful disposition, frequent changes from country to town, a diet regular, rather in times than always in quantities, with moderate passions, seem chiefly to contribute to an extended healthy old age.

Yet every thing must have a termination: each liv-being is born, grows, decays, and dies. In living bodies we find two principal forces which regulate their existence; the power of expansion and decay. The youth expands in bulk; his arteries are daily fuller, larger, longer; his nerves gradually firmer; his functions more active and powerful. When old age approaches, the veins are filled, and the arterial system acts more weakly; the irritability is less; the functions more weak; the glands are diminished in bulk; the fat absorbed; the fluids more thin and more acrid. The arteries can no longer conquer the accumulated load in the veins, the brain is overloaded, or serum exhales in the abdomen or under the skin; the vessels of the glands cannot propel their fluids, and these are in-farctcd; the nerves no longer possess their former irritability; and the senses decay. From all these causes the limbs grow stiff, the arteries ossify, the whole sys -tern is oppressed with a load which it cannot overcome, and man sinks to mix with his parent dust. Such is the lot of all ! Noctes atque dies patet atri janua ditis!

See Buffon's Natural History (edit, de Sonnini). Herder on Man. Virey Histoire Nalurelle du Genre Hu-main, 2 vol. 8vo. Vicq. dazyr Trait danatomie, Introduction. Camper's Works, translated by Cogan. White on the Gradation of Man. Halleri Elementa Physiologiae. Cuvier Anatomie Comparee, 4 vol. 8vo. Bell on the Expression of the Passions. See Foetus,Ration Haemorrhois.