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Digestion is explain'd by doctor Arbuthnot to be a fermentation begun, because, he says, there are all the requisites of such a fermenta. tion, because that requires a greater time than the continuance of the aliment in the stomach. Vegetable putrefaction, for the reasons he gives, resembles very much animal digestion. By mastication, saliva, the attrition of the folid parts, or inward coats, of the stomach, the gall or bile, the pancreatick juice, and the action of a di: solvent liquor, assisted with heat, the ali. ment is convested into a sort of chyle (a refemblance of milk or whey), and, passing through the mesen'ery, is receive'd into the veins, by means of the thoracick duct and the lacteals, becomes finally blood. As the nutriment, therefor, of the body depends entirely on the quantity of chyle, animals, which take a largeër portion of aliment by the mouth, may be less nourish'd than those which take a smaller : for, according to the force of the chylopoëtick organs, a largeër or less quantity of chyle may be extracted from the same quantity of food. * There is, of course, no essential difference in the quality of chyle,
* Essay concerning aliments, p. 1, 4, 8, 19, &c. See, allso,.. doctor Cheynes Vatural method of curing diseases, p. 22&q.
whether produced by the digestiön of animal substanceës, or by that of vegetables, though there may be much in the quantity.* All animals, in fact, are made, immediately or mediately, of vegetables, or of animals that are fed on vegetables ; and vegetables, therefor, are proper enough to repair animals, as being nearly of the same specifick gravity with animal substanceës, spirit, water, salt, oil, earth. t . Animal substanceës, doctor Arbuthnot observes, are more nourishing, and more easeyly transmutable into animal juiceës, than vegetable ; and, therefor, he says, a vegetable diet is more proper for some conftitutions, as being less nourishing; though he allows some vegetables, as carrots and turnips, are fattening to animals which live onely on ve. getables : and, elsewhere remarks, there may
.* Animal fubftanciës differ from vegetables in two things: firft, in that being reduced to ashes, they åre perfectly inlipid: all animal falts, being volatile, Aying off with great heat: secondly, in that there is no fincere acid in any animal juice, (P. 64). Animal substanceës, therefor, are all alka: lescent; of vegetable substanceës, some are acid, other alkalescent, (P. 105).
of lbi, p. 42.
be a stronger broth made of vegetables than any gravy-foup.* - In the memoirs of the royal academy for the year 1730, M. Geoffroy has giveën a method for determineing the proportion of nourishment, or true matter of the Aesh and blood, contain'd in any fort of food. He took a pound of meat that had been free'd from the fat, bones and cartilageës, and boild it for a determine'd time, in a close vessel, with three pints of water; then, pouring off the liquor, he aded the fame quantity of water, boiling it again for the same time, and this operation he repeated fix several times, fo that the last liquor appear'd, both in smel, trial and taste, to be little different from common water. Then, puting all the liquor together, and filtrateing, to feparate the too gross particles, he evaporateëd it over a now fire, til it was brought to an extrazt of a pretty moderate con fistence. This experiment was made upon feveral forts of food, the result of which is contain'd in the following table :
* Ibi, p. 181, 180.
Yielded of extract
s 03. dr.
veal ... 1 I 1 4
I 8 whey... HII 3
bread ... L41 According to this table, the proportion of nourilhment contain'd in these foods wil be as follows:
beef . . 7 ..... . veal . i . 9 mutton lamb. o . 9 chicken... pigeon . 8 pheasant . i 10 partridge .. 12 calves-feet ; carp. . . 8 whey... 9
bread ... 33.* So that common household bread has nearly three times the nutritive quantity of food above any other species.
* Doctor Cheynes Natural method of curing diseases, p. 54.
The reflections of M. De Saint-Pierre, tee specting the use of bread, become of such absolute necessily over all Europe, may be here subjoin'd: “ Who would believe," he says, “ that it is an aliment of luxury ? Of all those which are ferve'd up on the table of man, though it be the most common, and even when markets are at the lowest, there is none which costs fo dear. The grain of which it is made, is of all vegetable productions, that which demands most culture, machinery and handleing. Before it is cast into the ground, there must be ploughs to til the ground, harrows to break the clods, dunghils to manure it. When it begins to grow, it must be weeded; when come to maturity, the sickle must be employ'd to cut it down; fails, fạnners, bags, barns, to thrash it out, to winnow it, and to store it up; mils to reduce it to four, to bolt it; and to lift it; bake-houseës, where it must be kneaded, leaven'd, bake'd, and converted into bread. Veryly man never could have existed on the earth, had he been under the necessity of deriveing his first nutriment from the corn-plant. It is no where found indigenous. Nay, its grain, from the form and size, appears much better adapted to the beak of granivorous birds than to the mouth of man. Not so much as the twentyeth part of mankind eats bread. - Allmost all the