There are various milks used for dietetic purposes, some of these being likewise medicinal. Comprised among them are the milk of cud-chewing animals, human milk, ass's milk, and mare's milk. The essential difference between the first two of these milks is in the character of the casein, or card, and the proportions thereof to the other parts which do not clot. The milks of all mammals (creatures which give suck), consist of water which holds in virtual, or actual solution, salts, sugar, cream and other clotting substances, with minute globules of fat uniformly suspended throughout the fluid, though tending towards the top because of their lighter weight. Dilution with water will not alter the fact that cow's milk is acid in reaction, whilst the human variety, when drawn directly from the mother's breast, is alkaline. Ass's milk contains less solids than either of the other sorts, whilst being more rich in sugar than the rest (except human milk). It is poor in curd, and fat. being therefore light, and easy of digestion. This milk has in every age of physic been valued as a prime antidote to wasting from consumption of the lungs. Furthermore, leading authorities unanimously pronounce as to the superiority of ass's milk for rearing feeble infants.

But Dr. R. Hutchison disagrees from this generally received notion. He complains that being especially poor in fat, which is so important for infants, it is of itself ill suited for their nourishment. Moreover, it is slightly laxative, containing relatively more cheesy substance, and less albumin, than human milk. "The percentage of fat," says Ellenburger, "is much too low to make it proper for habitual use by children".

An artificial milk of the same nature as that of the ass may be easily made (on paper) by diluting cow's milk (thus reducing the percentage of sugar, curd, and fat) to the quality of mother's milk; but the difficulty of digesting the particular curd from the cow still remains to be overcome. On the whole, therefore, ass's milk is the nearest approach to good milk from the human mother. It is not yielded by the maternal animals unless the foals are allowed to be with their mothers in the donkeys' dairy, each foal having a smaller pen beside that of its mother. This article of nursery requirement fetches six shillings a quart, being sold in specially protected sealed bottles. The she-asses are milked twice a day, and afford severally from half a pint to a pint at each milking. For persons at a distance a milch donkey may be hired at the cost of one guinea a week, plus expenses of transport. The amusing fact may be remembered, but none the less will bear repetition, that Thomas Hood, in his famous Ode to Rae Wilson (1843), has drawn a most suggestive moral from the story of a consumptive girl for whom ass's milk was prescribed: -

"Once on a time a certain English lass Was seized with symptoms of such deep decline, Cough, hectic flushes, ev'ry evil sign, That, - as their wont is at such desperate pass, The doctors gave her over - to an ass. Accordingly, the grisly shade to bilk, Each morn the patient quaff'd a frothy bowl Of asinine new milk, Robbing a shaggy suckling of a foal, Which got proportionately spare, and skinny: Meanwhile the neighbours cried, ' poor Mary Ann! She can't get over it! she never can! ' When lo, - to prove each prophet was a ninny - The one that died was the poor wet nurse Jenny.

To aggravate the case,

There were but two grown donkeys in the place. And most unluckily for Eve's sick daughter The other long-ear'd creature was a male, Who never in his life had given a pail Of milk, or even chalk and water. No matter; at the usual hour of eight Down trots a donkey to the wicket gate, With Mister Simon Gubbins on his back. ' Your sarvint, Miss - a werry spring-like day; - Bad time for hasses, tho'! good lack! good lack! Jenny be dead, Miss; but I've brought 'ye Jack; He does'nt give no milk, - but he can bray!' "

"So runs the story; And, in vain self-glory Some Saints would sneer at Gubbins for his blindness; But what the better are their pious saws To ailing souls than dry hee-haws Without the milk of human kindness? "

It is a significant fact bearing on this subject, that asses are not susceptible of any tuberculous disease, such as pulmonary consumption.

Horace Walpole, and after him Byron, accused Lawrence Sterne (1758) of having preferred whining over a dead ass (see Sentimental Journey) to relieving a living mother in distress.

During the siege of Ladysmith, in the recent South African war, it became proved that while horseflesh is but sorry fare, and that of the dog not to be desired, yet the humble moke is, when dressed for table, rather a delicacy than otherwise. Thirty odd years ago the experience of the Parisians pointed to the same conclusion, (renin, the famous Restaurateur, pronounced that the dog was the siege-cook's despair; its flesh has a particularly disagreeable flavour which no seasoning can disguise. But "as to the other animal,"said he, "l'ane etait rare: on se trouvait heureux d'en avoir a quinze, ou vingt francs la livre. Le consomme d'ane a un petit gout de noisette tres agreable. En rosbif, avec des haricots a la Bretonne, assaisonne' de sa graisse, c'etait un vrai regal." Elia has discoursed of a young ass in "Christ's Hospital, five and thirty years ago,"to pamper which animal, a petty Nero of a schoolmaster nearly starved forty of the boys, by exacting contributions to the one half of their bread.

Incredible as it may seem, he had contrived to smuggle the ass in, and keep it upon the leads of the said boys' dormitory. "This game went on for better than a week, till the foolish beast, not able to fare well but he must cry roast meat; foolisher, alas, than any of his species in the fables, waxing fat and kicking, in the fullness of bread, one unlucky minute must needs proclaim his good fortune to the world below; and laying out his simple throat blew such a ram's-horn blast as (toppling down the walls of his own Jericho) set concealment any longer at defiance. The client was dismissed, with certain attentions, to Smithfield, but I never got to learn that the patron underwent any censure on the occasion".