Woman's milk, therefore, and that of the ass and mare, afford the lightest and least stimulant aliment ; the mill. of the cow, goat, and ewe, the most nutritive. In ano ther part of this work, when treating or the nursing of infants, we shall return to the consideration of woman's milk. At present we have only to add a few words on the alimentary properties of milk in general. Milk, though an aliment nutritious and wholesome, is not equally well digested by every stomach. It is apt to offend in two ways ; first, coagulating very firmly in the stomach, it occasions sickness, and is afterwards reject. ed by vomiting ; secondly, becoming acid, it gives rise to flatulence, heart-burn, pipings, and diarrlicea. When the tone of the stomach therefore is enfeebled, the pow ers of the digestive organs weak, and a tendency exits to the formation of acid, milk is not always found to an swer the restorative purposes for which it had been taken. Still, however, most people bear milk well, whe ther taken alone, or, what is better, along with the vege table larinacea. And in many cases of disease and con valescence, it may be usefully employed as a mild and restorative aliment. There is indeed reason to believe, agreeably to the general opinion, that it is the aliment of all others the most easily assimilated. Where it is found to sit too heavily on the stomach, it is advantageously diluted with water ; and to obviate its accsceney, it is sometimes prescribed mixed with soda or lime water. Sometimes again, it agrees better after having been boiled, though it is then more apt to produce costiveness. The constituent parts of milk are also separately em ployed as aliments.
Butter, the oily part of milk, is a highly nutritious food, and moderately used in its fresh state, very whole some. Like the other animal oils, however, it is too heavy to be used by itself; it is more safely eaten along with a due proportion of bread, or other aliment. Ran cid butter, or that which has been much decomposed in the processes of cookery, is extremely apt to disagree with most stomachs, and is not easily digested by any.
newly coagulated, and the parts not se parated from each other, differs but little in alimentary properties from uncoagulated milk. The curd separated from the whey, and gently pressed, is an agreeable and somewhat more nutritive aliment.
curd subjected to strong pressure, is highly nutritious. But the qualities of cheese are differ ent according to the modes of preparation, the quantity of oil retained by the curd, and the length of time it has been kept. Generally, cheese is an aliment of difficult digestion, and suited as an article of diet to the stomachs of the robust only. In many countries, it forms a con siderable part of the sustenance of the peasants and labourers. But, in general, it is used only as an adju vant, or condiment.
Butter Milk.—The portion of milk which remains after the separation of the butter by churning, is mode rately nutritious. It is, moreover, somewhat acid, and
thus affords a wholesome cooling beverage, grateful, and very useful in a heated or feverish state of the body. Dr Cullen has remarked, " that such acid does not encrease the acescency of the stomach, or occasion the flatulency that recent vegetable acids do ; and therefore it is more safely employed in dyspeptic persons." fluid which remains after the separation 01 the turd and oil, contains in solution, the saccharine and salMe parts of the milk, with a small portion of the animal principles. Its nutritive powers are therefore not very great. It is cooling, antiseptic, and aperient.
The ova of birds in alimentary properties bear no in considerable analogy to the milk ol the mannnalia, and conic therefore next to he noticed. The white 01 the egg consists almost entirely of albumen ; the yolk con tains albuminous matter, oil, gelatine, and water. Thus the egg is limited of the most nutritive alimentary prin ciples. And when these principles have been gently coagulated by heat, the egg is found to be a wholesome, as well as nourishing food ; one or two are easily digest ed by most individuals; a greater number, taken at one time, are apt to disagree. And indeed we may remark, with Dr Cullen, " that a smaller bulk of this than any other food, will satisfy and occupy the digestive powei s of most men." Eggs, according- to Lieutaud and other writers, are well suited to those who are subject to acid crudities of the stomach and primee vi c. They arc said also to favour the secretion of bile, and so to disagree with those of the bilious temperament. On the other hand, raw eggs have been thought serviceable in the jaundice, and in cases of obstructed liver. By Mr White of 'Manches ter, they have been especially extolled in the icterus of pregnant women.
The eggs of different fowls differ less in alimentary than might at first he expected. The chief difference consists in some variety of flavour. The eggs of the granivorous luNVlS, and especially of the common domestic fowl, arc confessedly the best.
Of the solid parts of animals almost all are alimenta ry ; and according to the nature, proportion, and state of combination of the principles of which they are formed, they are more or less nourishing, more or less suscepti ble of digestion.
The while parts, comprehending the skin, cellular texture, the membranes, ligaments, cartilages, and ten dons, which consist almost entirely of gelatine and con densed albumen, unless they have been much softened and dissolved into jelly, by long boiling, arc more diffi cult of digestion, and afford even then a nutriment of a lighter and less stimulating nature than that derived from other parts containing a due admixture of the other alimentary principles.