oxygen is consumed, than when vegetable aliment is employed. Mr. Spalding, a diver, also found that he consumed more atmospheric oxygen in his diving bell, when he had used a diet of animal food, or drunk spirituous liquors; and experience, therefore, had taught him that vegetable food, and water for drink, were best adopted for the performance of the duties of his business.* Dr. Fyfe, however, differs from Mr. Spalding, in his account of the effect of alcohol on the respiratory function. It is very probable that the excess of oxygen which is found in the pectinaceous principle, or vegetable jelly of fruits, and in the other non-azotized principles of vegetables generally, is the means of thus diminishing the function of respiration (95).

464. Another fact is also worthy of observation in connexion with our subject. So far as chemical tests are concerned, the chyle of all animals is the same, whatever kind of food it may be formed from; but with regard to its physiological qualities, and its relations to the vital economy, its character varies with the food. Dr. Marcet, Oliver, and other physiologists unite in stating, that chyle elaborated from animal food putrefies in three or four days at longest; while chyle from vegetable food-from its greater purity, and more perfect vitality— may be kept for many days, without becoming putrid.

465. It is said by Mr. Graham to be "well known, also, that human blood formed from animal food, will putrefy when taken from the living vessels, in a much

* SEE DR. JNO. MURRAY'S "SYSTEM OF MATERIA MEDICA AND PHARMACY." Vol. I. P. 509. Fifth edition. EDIN. 1828.

shorter time than that formed from pure vegetable aliment; and that there is always-other things being equal a much greater febrile and putrescent tendency in the living bodies of those who subsist mostly on animal food, than in those who subsist wholly on pure vegetable aliment. Hence, if two healthy, robust men of the same age,—the one subsisting principally on fleshmeat, and the other exclusively on a diet of vegetable food and water,-be suddenly shot down and killed, in warm weather, and both bodies be laid out in the ordinary manner, and left to the action of the elements and affinities of the inorganic kingdom, the body of the vegetable-eater will remain two or three times as long as the body of the flesh-eater will, without becoming intolerably offensive from the process of putrefaction."*

466. From the whole of these facts, therefore, we may conclude, that the more stimulating and heating the diet, the more rapidly the changes in the relative proportion and conditions of the solids and fluids take place,-the more rapidly ossification, the great process of decay, is accelerated; the solids becoming dry, inelastic, and unyielding. Hence a diet of animal food is less favourable to longevity, than what we have seen to be the original and natural diet of man ;-namely fruits, roots, and grain, with other farinaceous substances; which form chyle, blood, and tissues, less subject to chemical decomposition, and requiring less rapid changes for the production of animal heat. The quicker the motion of any complicated piece of machinery, the sooner it is worn

* GRAHAM'S LECTURES. Vol. II. P. 115.

out; and the observation is equally true when applied to the animal structure. Each process of decay and renewal, brings it nearer its final destination; and the more we accelerate these changes, by stimulating food to the stomach, and oxygen to the lungs, the sooner will the period of old age and decrepitude overtake us.

467. "Though the vital energies and sensibilities, therefore, which we exhaust to-day, are replenished tomorrow, yet (of necessity) the process has taken something from the measured fund of life, and reduced our vital capital in proportion to the frugality or the profligacy of our expenditure. However proper the nature and condition of our aliment, however completely all our laws of external relation are fulfilled, however perfectly the functions of our organs are performed, and however salutary their results, yet every digestive process of the stomach,-every contraction of the heart, draws something from the ultimate and unreplenishable resources of organic vitality: and consequently the more freely and prodigally we expend the vital properties of our organs, the more rapidly we wear out the constitutional powers of replenishment, and exhaust the limited stock of life. Nothing, therefore, can be more dangerously fallacious than the opinion, which is too generally cherished and too frequently promulgated, that our daily trespasses upon the laws of life, are as the dropping of water upon a rock —wearing indeed, but so slowly and imperceptibly, as scarcely to make a difference in the duration and in the comfort of our lives." *

* GRAHAM'S LECTURES. Vol. II. P. 94.

468. "The more slowly man grows," says Professor Hufeland, "the later he attains to maturity, and the longer all his powers are in expanding, the longer will be the duration of his life; as the existence of a creature is lengthened in proportion to the time required for expansion. Every thing, therefore, that hastens vital consumption, shortens life; and, consequently, the more intensive the vital action, the shorter the life. If you would live long, live moderately, and avoid a stimulating, heating diet; such as a great deal of flesh, eggs, chocolate, wine, and spices." Animal food, and all other stimulating diet, particularly in youth, do incalculable mischief; though by such slow degrees that, in general, the evil is neither perceived nor suspected. The stream of life is hurried on precipitately; the passions are prematurely developed; and-like a plant that has been forced too rapidly, by artificial heat and stimulating composts-the organism is exhausted; and it becomes. diseased and old, when it would, under a more appropriate diet, have been in its perfection. (455).

469. Celsus affirms, that "the bodies which are filled in the manner of the athlete (that is, with much animal food) become the most quickly old and diseased."

66

Every physiologist must admit, that flesh is of a more stimulating and heating nature,-causes a more rapid pulse, a hotter skin,-hastens all the vital functions of the body,―causes a greater exhaustion of the vital powers of the organs, and wears out the human constitution considerably faster, than a proper vegetable diet. Hence, great longevity is never found among those tribes and

portions of the human family, who subsist principally or entirely on flesh-meat. The Patagonians, with a climate and almost every other circumstance (except their diet) exceedingly favourable to longevity, rarely attain to seventy years of age; and the average duration of life is greater with them, than with any other flesh-eating tribe or nation.

*

470. "It has been established by nature, on the best grounds," says Hufeland, "that our nourishment should be used in form rather coarse ;-securing full mastication and insalivation, and a longer retention in the stomach.—Plain, simple food only, promotes moderation and longevity; while compounded and luxurious food shortens life. The most extraordinary instances of longevity, are to be found among those classes of mankind, who, amidst bodily labour and the open air-lead a simple life, agreeable to nature;-such as farmers, gardeners, hunters, &c. The more man follows nature, and is obedient to her laws, the longer will he live the further he deviates from these, the shorter will be his existence. Rich and nourishing food, and an immoderate use of flesh, do not prolong life. Instances of the greatest longevity are to be found among men who, from their youth, lived principally on vegetables, and who, perhaps, never tasted flesh." "It seems", says Lord Bacon, in his Treatise on Life and Death, "to be approved by experience, that a spare and almost a Pythagorean diet-such as is prescribed by the strictest monastic life, or practised by hermits is most favourable to long life."

* GRAHAM'S LECTURES. Vol. II. P. 269.