13. of Bread, yielding 18 ozs. of Starch, and 3 ozs. of Gluten. lb. of Beef, 2 ozs. of Fibrin. Total consumed by Respiration and the Ordinary Waste, 18 ozs. of Starch, and 5 ozs. of Gluten and Fibrin.

205. This calculation is based on the supposition, that wheat-flour contains 15 per cent of dry gluten; and as Mr. J. says, 12tb. (or 28 ozs.) of bread contain 3 ozs. of gluten, the same as 20 ozs. of flour, we learn that he considers 20 ozs. of flour to make 28 ozs. of bread.

But

in a previous table (page 229) he informs us, that 15000 Ibs. of wheat contain 825lbs. of starch, 315lbs. of dry gluten, and 60lbs. of sugar. Now divide each of these numbers by 15, and we find that flour contains 21 per cent of gluten, and about 60 per cent of starch and sugar. With this correction we have,

13lb. of Bread=20 ozs. of Wheat-Flour, yielding 12 ozs. of Starch, and 4 ozs. of Gluten.

b of Beef, yielding 2 ozs. of Fibrin.

Total-12 ozs. of Starch, and 63 ozs. of Gluten and Fibrin.

206. There now appears a deficiency of 6 ozs. of starch, and a surplus of 1' oz. of gluten, when bread and beef are taken. Again:-2lbs. of bread yield 13 ozs. of starch, and 4; ozs. of gluten;-leaving a deficiency of only 4 ozs. of starch, to be supplied by potatoes, rice, &c.; and of an oz. of gluten;-so that, from Mr. J.'s own data, 24lbs. of beef and bread, do not supply the required amount of starch and albumen, so well as 2tbs. of bread; and this is precisely the weight of bread that

has been found practically sufficient for a man taking ordinary exercise. Vogel says, wheat-bread contains 53.5 per cent of starch; consequently, 2lbs. will contain 17% ozs. of starch,-only fo of an oz. short of the requisite quantity.

207. Organic Chemistry, however, has not yet been brought to such perfection, as will enable us to mete out man's food by its laws. We have yet much to learn in this respect; and a short notice of the subject is introduced here only to show, that from the vegetable kingdom may be selected, for human food, such articles as will bear a comparison with a mixed diet, so far as our present knowledge will permit us to judge; and that the light already thrown upon the matter, by chemistry, is sufficient to prove, that fruits, grain, roots, and other esculent vegetables, if used in a natural, unrefined, and unconcentrated state,—contain every principle necessary for the nourishment of man.

208. Various substances may contain all the principles necessary to complete nutrition, and yet be either partially or totally indigestible, arising from a deficiency of relation between those substances and the organs of assimilation. Thus grass may be indigestible in the stomach of a lion, while to the ox it proves a wholesome and nutritious aliment. The organs of digestion in man, also, are subject to determinate physical laws; but, being of an intermediate character (as has been previously shown, 76) between the carnivorous and herbivorous animals, their functions admit of a wider range; andthough not so perfectly adapted to the digestion of flesh

as the assimilating organs of the tiger, nor formed with so direct a relation to herbaceous matter as those of the sheep or the ox-habit will enable man to subsist, with tolerable health, upon certain kinds of either, or a mixture of both. But it has been shown (80, &c.), that the appropriate food of man is fruit, roots, and grain; and these not only admit of the easiest solution in the human stomach, but also create the least inconvenience through the whole of the alimentary canal, produce the healthiest chyle, and purest blood. I am aware, that some persons have questioned the fact of vegetable food being so easily digested in the human stomach; and have instanced various functional disarrangements, from the eating of fruit, &c. Dr. Cullen said he had known portions of apple eructated, whithout alteration, two days after they had been swallowed; and such cases undoubtedly occur: yet Dr. Beaumont found that apples are easily digested in the stomach;-requiring only about an hour and a half for the purpose.

209. Various causes may be assigned for the indigestion of such articles of diet. I shall only mention what I consider to be the three principal:-1. The habit of indulging in a totally different kind of food; for it is proved, that the change from a bad or inferior kind of diet, to a better or more natural one, often causes temporary inconvenience, if this change do not take place by degrees; because, by a wise economy of nature, the gastric juice is always secreted of such a character as is best adapted to the solution of the food we habitually feed upon (82): indulgence in any unusual kind of diet, therefore, may

sometimes disorder the stomach, even though the food be more natural than what, from habit, is said to agree better with the stomach. Kittens (as previously mentioned) (104), when brought up on vegetable diet only, have been rendered sick when made to eat flesh,-the food designed for them by nature. Hence we Hence we see the necessity of making all great changes in diet with caution, and by degrees; that the gastric juice, and other secretions, may be gradually adapted to the new circumstances.

210. 2. Most people, in this country, eat their fruit at the most objectionable time possible; namely, after a full meal of animal food, and a host of other incongruous mixtures. When the stomach has been already gorged with a variety of fish, flesh, and fowl,-with rich sauces, condiments, and vegetables, need there be any surprise, that the vegetable pectin and acids of fruits, should create disturbance in the stomach and alimentary canal? Surely every thinking man would expect such a result. But the whole blame is laid upon the fruit; instead of being attributed to the proper cause, the injudicious mixture of ingredients.

211. 3. The third cause of indigestion from fruit, is imperfect mastication and insalivation. It was shown (62, 63), that neither the cheek-teeth nor the under jaw of the carnivorous animal, is formed for mastication; nor are their salivary glands large, or the secretions from them copious. These animals, therefore, tear their food, and swallow it without chewing; and if man would be carnivorous too, let him follow their example, and save his teeth. But fruit, and other vegetable food, is so far

different from flesh, that it requires careful mastication, and mixture with saliva, previously to deglutition; otherwise it may remain long in the stomach, before the gastric juice can effect its complete solution. The character of the molar teeth in man and herbivorous animals, proves that nature intended fruits and vegetable food to undergo these processes; but if these substances be received into the stomach without previous preparation, along with seeds, flakes of integument, &c., they will excite a rapid motion of the stomach, (as shown by the experiments of Schultz,) and will be propelled into the duodenum, before the necessary changes have been effected. Vegetable matters thus hurried into the small intestines, create considerable disturbance; which is often referred to the acidity of the fruit. Having undergone little or no change in the stomach, the duodenal changes are necessarily imperfect : hence the development of gases, increased secretion from alimentary tunics, and spasms. But the experiments of Dr. Beaumont and of others prove, that when fruits, roots, and farinaceous substances, have been well masticated and mixed with saliva, they are easily digested in the healthy human stomach, and answer all the purposes of complete nutrition.

212. A short statement of facts from Dr, Beaumont's Tables, will confirm these remarks. He informs us, that the following articles were converted into chyme, or digested, in the times mentioned.