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might be adduced to substantiate them; certain chemists and physiologists have ventured to call them in question; -some, perhaps, from a misapprehension of the term "low diet", or from not having fully and fairly considered the claims that a well selected vegetable diet has upon their attention; and others from too hasty an adoption of certain theories or statements of Professor Liebig.

321. Dr. W. Tyler Smith has lately written a work on scrofula, in which he freely animadverts on the poor and insufficient food in many of the Union Work-houses, and makes the following observations on the advantages of a mixed diet. "Prout and Majendie have shown, by reasoning and experiments, that a mixed diet of the different kinds of animal and vegetable food, is the most conducive to health. Such an admixture of alimentary substances seems to amount to almost a positive law; and is probably of more importance to those inclined to scrofula, than to any other class. Nevertheless the children of the poor, and even of the rich, are often unduly stinted in the use of animal food;-the one from the opinion that a vegetable and farinaceous diet is the most wholesome, the other from inability to procure a sufficiency of meat. There can be little question, looking at that state of the body which is most exposed to scrofula, that a purely vegetable diet-particularly in childhood, when the foundations of a weak or strong constitution can generally be laid-is most injudicious."

322. The experiments of Majendie have already been examined (213, &c.); and it has been shown, that they

warrant no such conclusion as the above. We only learn from them that the unmixed proximate principles, whether derived from the animal or vegetable kingdom, are insufficient to support life; and that substances highly concentrated by artificial means, are injurious to health. The experiments and reasoning of Dr. Prout certainly show the necessity for a due admixture of the aqueous, saccharine, albuminous, oleaginous, and (perhaps) ligneous principles, in human food; but these are found in combination in the various fruits, grain, roots, &c., which have been previously shown to be the natural food of man ; and it is only when we attempt to refine upon nature, that these valuable principles are separated. None of the observations of Dr. Prout, however, prove the necessity for a mixture of animal and vegetable matter in human food; nor can it be shown from Anatomy, Chemistry, Physiology, or any of the kindred sciences, that for the preservation of health man requires either an animal or a mixed diet.

323. That the children of the rich frequently suffer from feeding on too concentrated a diet, such as preparations from the finest wheaten flour, arrow-root, &c.,—there can be no question; but that their liability to scrofula, and other diseases, is consequent upon abstinence from animal food, is by no means a warrantable inference. If Dr. Smith's view of the subject were correct, we might expect to find scrofula exceedingly prevalent among the Hindoos, the Irish, the Scotch, and many other people in various latitudes, who either never or very seldom taste animal food; and yet among these are found examples of the

most robust health. Dr. Prout has shown, that mal-assimilation, which may occur under an animal, a vegetable, or a mixed diet, is frequently the exciting cause of tubercle. The inferior and unwholesome food, both of an animal and vegetable nature, upon which the poor are reduced to the necessity of feeding, may well be called "a low diet"; though people in very humble circumstances prefer the finest flour, both for themselves and their children, as more economical. In the case of the adult poor, it is mixed with so many other things of an innutritious nature, that no ill consequences may result; but to their young children, when it constitutes the principal part of their nutriment, it must be injurious.

324. Dr. Smith admits, that "fresh vegetables are of considerable importance in keeping the blood in a pure and wholesome condition, when the child has arrived at a proper age to digest any kind of food"; and illustrates his remark by a reference to the prevalence of scrofula among the boys of Christ's Hospital; which he attributes chiefly to the absence of fresh vegetables from their dietary; their supply of animal food being good, both as regards quantity and quality. "Gross living", continues Dr. Smith, "is almost as influential as a poor diet in producing the disease, when the diathesis is highly developed. Scrofula is very common among some of the children of the poor, who are bloated from having a tolerable supply of food, and living without excercise in confined apartments. Abundance of rich and stimulating food, often renders strumous children so unwieldy, as to prevent healthy exercise: it disorders the stomach and

digestion, and vitiates the whole mass of fluids to such a degree, that blotches, or small indurations, form in different parts of the body, and produce scrofulous sores: or the slightest scratch or wound, in such cases, instead of healing, will begin to discharge, and speedily acquire the scrofulous character. Nothing is more common than for such children to get strumous disease of the scalp, obstinate scrofulous ophthalmia, otorrhoea, or discharge from behind the ears, and sores upon the mouth. In many cases, it almost seems as if scrofulous sores were set up, as a means of consuming the superfluous material which has been introduced into the body."

325. These latter observations of Dr. Smith, accord with those of Dr. Prout; and there can be no doubt as to their correctness: for when muscular exercise is not proportionate to the amount of nutriment received, converted, and absorbed, nature is sure to set up some action, to relieve the circulatory system from the excess; but Dr. Smith has adduced no facts to prove, that a scrofulous habit is ever the consequence of an exclusively vegetable diet, when of a proper kind and quality; and if the accouut of the boys in Christ's Hospital may be depended upon, it is a proof of the injurious tendency of too animalized a diet. The diseases of the poor are attributable to many causes;-such as impure air, dirty habits, exposure to cold, and a scanty, low, innutritious diet; consisting, frequently, of the worst quality of vegetable substances, and the offal of butcher's-meat, perhaps rendered still more unwholesome by disease in the animal killed to supply it.

326. The views propounded by Liebig, respecting the ultimate destination of azotized and non-azotized articles of diet in the animal economy, are thought by some to sanction the use of animal food, and particularly where the lithic acid diathesis prevails. He is of opinion, that the amount of azotized matter in the urine, may be regarded as a measure of the decomposition which takes place in the azotized tissues; and that the quantity of urea and lithic acid, the products of the metamorphosed tissues, increases with the rapidity of transformation in a given time, but bears no proportion to the amount of food taken in the same period. "There can be no greater contradiction," says he, "than to suppose that the nitrogen of the food can pass into the urine as urea, without having previously become part of an organized tissue.” He also believes, that the use of wines, fat, oil, and other non-azotized articles of food, prevents the oxygen of the atmosphere from combining with the uric acid, to form urea. He further observes-" Gravel and calculus occur in persons who use very little animal food. Concretions of uric acid have never yet been observed in carnivorous mammalia, living in the wild state; and among nations which live entirely on flesh, deposits of uric acid concretions in the limbs or in the bladder, are utterly unknown."

327. Relying upon these views as firmly established, Dr. Bence Jones (in his work on gravel, calculus, and gout) recommends a diet principally of animal food in these diseases: it becomes, therefore, a matter of great importance to ascertain, whether these opinions of Liebig