dom occur. But in a more advanced age, when the pulsations of the heart are faint or slow, and its irritability is diminished, a warmer region is more salutary; and he recommends aged persons to migrate 30 or 40 degrees, or even nearer to the equator, where they may enjoy, at pleasure, the genial warmth of the sun, or the cooling shade.
Among the internal causes of longevity, the rudiments of a sound body, descended from parents uncontaminated by hereditary disease, are to be considered as the principal: thus dropsy, gout, apoplexy, consumption, and the long train of disorders, that are too frequently transmitted from one generation to another, will in a great measure be prevented. With respect to the mode of living, Haller recommends abstemiousness during youth; the drink should be water, which Nature has provided for our common use; and he justly considers wine as a species of medicine. Animal food should be sparingly eaten, together with a large proportion of vegetables, and but a small addition of saline or aromatic substances. Temperance is, in every respect, an essential point; so that the quantity eaten, may be well digested, and perfectly assimilated; that the blood may circulate regularly, and free from all corruption or infection, similar to that of an infant. Aged persons, however, may somewhat more freely indulge in the use of animal food: on the other hand, tranquillity, both of body and mind, is of the greatest consequence; as nothing is more detrimental, than an irritable or irascible disposition. Hence, a due mixture of a lively and placid temperament, is a very desirable condition, so as to be neither insensible of pleasure, nor too much addicted to the gratification of sensual desires. Moderation is, therefore, here likewise a beneficial attribute; but, with regard to sleep, old and decrepit people may be more indulgent.—Those readers, who are anxious to become acquainted with more minute rules and directions for prolonging human life, both in a state of health and disease, will derive considerable information from Professor Hufeland's "Art of prolonging Life" (8vo. 2 vols. 10s. Bell, 1797), and from Dr. Struve's Asthenology: or, The Art of preserving feeble Life" (8vo. 8s. Murray and Highley, 1801), in which the subject is amply and philosophically discussed.
Life-Annuities. See Annuity.
LIGATURE, a bandage or fillet, made of linen, flannel, leather, or any other elastic substance, which is generally tied round the arm, to facilitate the operation of blood-letting.
Ligatures are likewise used to extend or replace bones, which are broken or dislocated; on the arteries, during amputations, or in large wounds; and also to secure the splints that are usually applied to fractures.
Although the instinctive propensity of the lower animals, to pinch or compress wounded or painful limbs, seems to have furnished mankind with a hint for the application of tight bandages or ligatures, with a view to intercept the nerve in its course from the part affected to the brain; yet such practice is not always safe. We know instances where, in consequence of too long continued com-
