Mankind would have fallen into a thousand errors in selecting food for the new-born infant, had it not been apparent that the maternal breast was designed to furnish the proper nourishment.
That the milk of the female is intended for her child, is a fact which has never been expressly denied; yet suspicion might seem to be thrown upon it by the conduct of some mothers, who, with no disqualification for suckling, decline the duty, and without scruple transfer it to the hired and doubtful affection of others. When the health of the female is good, however, and her milk plentiful, no excuse for such a course is admissible, whatever be her rank in society; as it is just that she who determines not to suckle, ought not to become a mother.
There are circumstances, undoubtedly, which disqualify a female from nursing her own infant. The following, amongst others, may be enumerated. A defect in the structure of the breasts or nipples, either natural or from disease, rendering them unfit to yield milk. Disease, either constitutional or local, affecting the mother, so as to render her milk scanty or unwholesome. The secretion of milk, though abundant at first, soon failing from constitutional peculiarity. Likewise when, from the delicacy of the mother, her own health, or that of the infant is likely to suffer.
This latter reason is one but too often assigned by those who decline suckling. It is by no means easy to determine what degree of delicate health incapacitates for this duty; a conscientious mother will therefore carefully scrutinize the motives which induce her to take so important a step; lest indolence, the love of gaiety, or of freedom from restraint, be found to be of the number. When delicate health is the only plea for not suckling, in general it is well to make the attempt. Perservering attention to the various means that invigorate the health will do much. And, moreover, nursing is occasionally known to improve the health of even the most delicate, -- of such as, to all appearance, were the least likely to support its fatigues. This fact, which must be highly consoling to many, ought to prevent even the most timid from finally determining not to suckle, at least till the experiment has been fairly made. It is also to be remembered, that a single failure is no just ground for discouragement with regard to future attempts: on the contrary, many a mother having failed in repeated trials, has yet afterwards become an excellent wet-nurse. 
When the infant is not suckled at the maternal breast, there are various substitutes which have been adopted; such as the offices of a hired wet-nurse; feeding by the hand; and suckling by one of the inferior animals, as the goat, sheep, or bitch. The first, when attainable, is to be preferred, as the chances of life for hand-fed children are extremely few; and the latter means -- suckling by a brute animal, is, I believe, seldom or never thought of in this country. It might however be advisable under peculiar circumstances. 
Though a hired wet-nurse is certainly the best substitute for the mother, yet we are not to suppose that she is equally proper; and that a child in such a case will thrive as well as when nourished at the maternal breast: it is natural the milk of every female should best agree with her own infant: and besides, however suitable a wet-nurse may be in other respects, the affection of a mother is one of the few things that cannot be hired.
Connected with the choosing of a nurse are both difficulties and dangers. In this country, the class of persons from which she is commonly selected, contains many, particularly the unmarried part, whose moral character is doubtful; and even the married are mostly mercenary, or extremely poor; circumstances, either of which detracts from the best qualities of a nurse. Indeed, unless when a female loses her infant by death, the fact that she deserts it for the sake of hire, though in some instances it may be justifiable, is, in general, but an unfavourable index of her natural affection.
The faults and failings of wet-nurses are noticed by writers, both in verse and prose, in a manner which shews they have never been general favourites. We are told of their laziness, gluttony, licentiousness, insolence, unfaithfulness, and cruelty to their charge; with other traits still more forbidding; forming together a catalogue only equalled by that singular description of women in "Aylmer's Harboroughe," quoted by the Rev. Dr. M'Crie in his life of Knox: and to which I have much pleasure in referring the curious reader.  There is certainly no little absurdity in this. It is to be wished that such a class of servants could be dispensed with; but since that may not be, it serves no useful purpose to charge them en masse with crimes which, if true, would long since have procured the extinction of their name and office. In the choice of a nurse, as in that of other servants, caution and strict scrutiny are necessary, with this difference, that a correct knowledge of the state of her health is indispensable. Upon this point no evidence should satisfy, except a professional opinion; for it is certain that infants have been destroyed by disease taken from a syphilitic wet-nurse; and the bare possibility of such a calamity should excite parents to the utmost vigilance. It lately fell to the lot of the writer to be consulted in a case of this kind. The nurse, a married woman, became infected, as was said, by her husband. However that might be, the infant in her charge, a fine girl of six months old, perished from the complaint after severe and protracted sufferings. Were it necessary, many cases of a similar kind might be adduced.
Those writers who have drawn the character of a wet-nurse, with so much shading, have also favoured us with a delineation of the qualities, personal and mental, that she ought to possess; and which, were they generally realized, would render her far from disagreeable.
"She ought," says a French writer, " to be neither very young, nor very old. Under the 20th year, she has not attained her full development; and above the 35th she is on the decline. She should be well formed, neither lusty nor very thing: her colour should be fresh and blooming; the teeth sound and beautiful; the lips scarlet; the breath sweet; her hair neither very dark, nor yet inclining to be read; and she should be free from all violence of temper. The breast ought to be a little full, with a nipple easy to be taken hold of, and so sensitive as to yield the milk on the slightest suction. Her milk should neither be thin nor very watery, and of a pleasant agreeable flavour. Superadded to all these excellent qualities there ought to be a good moral disposition, that they may not be neutralized by any prominent defect of character; but, on the contrary, that she may uniformly regulate her whole conduct with a view to the welfare of the infant." &c. 
This description well deserves being remembered. At the same time, as few mothers possess all the qualities here enumerated, we should not be too fastidious. If a nurse has perfect and vigorous health; if the breast and nipple are properly formed; if the milk is plentiful, and of good quality; if the temper is mild and patient: and the morals are correct; more need not be required.
There is one painful consideration connected with the hiring of a wet-nurse, which is but seldom weighed sa it ought to be: and that is, the fate of her own infant. We are informed by Dr. John Clarke, that "in some families in London, six; in others, eight (successive) wet-nurses had lost their own children:" and that in commiseration of this description of orphans, Dr. Denman, some other professional gentlemen, and himself, endeavoured to establish an asylum for their reception; "but found that the expenditure was too great to be supported by private munificence." The following sentiments of the same excellent writer are highly creditable to his understanding: "It is hardly a question of whether society at large is a gainer or loser by the employment of hired wet-nurses. If the child lives, for which the wet-nurse is invited by the prospect of present gain to forsake her own, the child of the wet-nurse often dies; or it becomes diseased or crippled: her other children are neglected, and her husband, for want of her society, becomes drunken and profligate: she rarely returns home contented with her former station, but compares her present privations with the indulgences she has left: the whole comfort of the labouring man's fire side is broken up; and society has only exchanged the life of one child for that of another, with all the disadvantages above enumerated."
These are certainly appalling evils: but they are such as cannot be altogether obviated. In many cases the best plan would be to permit the wet-nurse to suckle her own and the foster child together, as advised by Dr. Clarke; or, if this may not be, to take care that the former is provided with a breast, and placed, if possible, in the country. How far it is right to seek the preservation of our own child by hazarding the life of another's, I do not take upon me to determine; but in the case in question there can be one opinion; that it is our duty to make the unfortunate infant ever amends in our power for the deprivation of that to which all have a natural claim -- the milk and affection of a mother.
The milk of a wet-nurse ought, if possible, to be nearly of the same age as the infant for which it is intended. This is a circumstance too little regarded. It is not unusual to see an infant soon after birth put to a breast which has already yielded milk for 8 or 10 months; but the effects of a such a practice are invariably mischievous. At so early a period of life the colostrum or first-milk is needed to purge the bowels. Medicine may be substituted, but no medicine answers so well. It is not, however, in the earliest stage of infancy only that the milk's being of a corresponding age is important. From delivery to the period of weaning, the qualities of the milk are constantly varying, to suit the progressive changes in the wants and structure of the growing child. This circumstance should therefore be always kept in mind in selecting a wet-nurse.
When a mother, or hired nurse, becomes seriously ill, she ought immediately to decline suckling. We should justly hesitate to drink the milk from a cow or an ass affected with disease; and, for the same reason, an infant ought not to be permitted to draw its nourishment from other than a healthy source. Mere local disease is not meant, but those complaints only which, affecting the whole body, disorder the secretions generally, and the secretion of the milk among the rest.
It is not easy to say, what complaints do, or, do not disqualify for giving suck, without risk of misleading. Some nurses are subject to periodical ailments; the health in the intervals being good: such as are sick head-aches, old agues, asthma, and the different forms of hysteria. In these complaints suckling should be avoided during, or immediately after, an attack; as the milk will be more or less altered, and may even seriously disorder the infant.  Consumption of the lungs is a different case. A consumptive female becomes pregnant, and in due time is delivered of a healthy child. Pregnancy, it is well known, generally suspends the malady; but after delivery its march is accelerated. Ought a mother under such circumstances to suckle her infant? It is scarcely possible that her food can be well digested, and assimilated, or her blood duly arterialized in its passage through diseased lungs; when we consider this, and the absorption of purulent matter formed in the progress of the complaint, which must pass into the circulating stream; it is difficult to conceive that the milk which is separated from the blood by secretion can escape being vitiated. On this point however experiments and further observations are wanting. 
As a general rule, the infant is to be put to the breast within 5 hours after birth. Though no milk may be obtained at first, the suction will soon bring it. In most cases this proceeding is delayed 24 or 30 hours; till the mother is feverish, and her breasts become hard, swelled, and painful: the infant meanwhile is fed on a variety of improper things which seldom fail to produce colic and gripes. From the very delay here mentioned arise nine-tenths of all the cases of sore nipples, and milk fever, which occur. The ordinary manner in which sore nipples are produced is this; the great distention of the breast buries the nipple, so that it can only be seized by the infant after long continued efforts; it thus becomes fretted and inflamed. Excoriation, as might be expected, soon follows.
With regard to what is called milk-fever: in most cases there is some degree of fever when the secretion of milk is commencing; by and by the milk vessels of the breast are painfully distended; these not being duly emptied, the pain and general fever increase; sometimes till the system is thrown into considerable disorder.
A frequent attendant on milk-fever is the gathering of a part, or the whole of the breast; which is occasionally productive of most acute suffering and even danger to life. Such an accident rarely happens in brute animals; and the reason may be, that their young seek the dug almost as soon as they are brought forth, and thus prevent the painful distention of the milk vessels, so frequent in the human female. If we wish to follow nature we ought, in a judicious degree, to imitate this most salutary instinct: and they who doubt the ability of the infant to draw the breast so soon after birth, have only to observe how vigorously it will being to suckle its lip or a part of the dress, almost immediately on being separated from the mother.
There is a prevailing, but an erroneous notion, that an infant cannot be too frequently suckled. On the contrary, every third or fourth hour is sufficient during the day: and each time the breast ought to be drained. By a little perserverence on the part of the nurse, and by taking care that the babe is suckled just before going to rest, it will acquire the habit of passing the night without the breast. Indeed, by beginning early, much may be done to divest nursing of many of the more irksome circumstances that usually attend it; and which, were the feelings of the mother less interested, must often render it an intolerable labour.
A nurse should live by rule. Her food ought to be nutritive, and easy of digestion. High seasoned dishes, pickles, and every thing that may stimulate to an over indulgence of the appetite ought to be avoided. When the secretion of milk fails, it is common to take to a richer and more stimulating diet; but this, in a majority of instances, instead of remedying, increases the evil. Plenty of succulent food, as light broths, mik, and vegetables, with the addition of fresh beer, are, if the health is good, the more judicious means. 
It is a popular notion that unripe fruit taken by the nurse will gripe the infant: and indeed there can be no doubt that many things pass, in the milk, from the nurse to the child. A dose of salts will generally in this way produce smart purging. It is also well known that when mercury is prescribed for a nurse and her infant, it has only to be given to the former to ensure its peculiar effects upon both.
The ordinary beverage of a nurse should be whey, milk, and brisk beer or porter. Wine may sometimes be necessary; but spirituous liquors are in no case allowable. 
A nurse ought to be regular in all her habits, whether of exercise or amusement; as good health and cheerfulness are the best of all qualifications for her peculiar duties: late hours, dissipation, indolence, every practice calculated to produce nervous complaints, should be religiously avoided. Exercise in the open air is indespensable. A sedentary nurse as little consults the interest of her charge, as she that indulges in all the dissipation of gay life. Indeed, a mother who does not prefer the health of her infant to every selfish gratification whatever, is of the number of those who had better decline the office of wet-nurse in favour of a hired substitute.
It is of singular importance, that the mind of a nurse be kept tranquil. Nothing so soon alters, and even suspends, the secretion of milk as violent mental emotion, especially that produced by the depressing passions. Glandular secretion is well known to be, in a peculiar manner, under the influence of the nervous system; and its healthy state depends more on mental tranquillity than on any particular condition of the blood. The profuse discharge of tears consequent on grief, or the feeling of pity, and its suppression in despair; the effect of rage and terror on the saliva; of anxiety on the perspiration; and other phenomena of a like kind, which are familiar to every one; shew how important it must be to the healthy secretion of milk in the female breast, that all strong mental excitement and even uneasiness be guarded against. It is asserted by respectable authors, that the milk of a nurse, soon after a furious sally of temper, has produced convulsions in the infant. Effects of a somewhat similar kind have followed intense grief. On one occasion, the writer witnessed the influence of this passion in the case of a hired wet-nurse. The circumstances were such as could hardly give rise to mistake. She had left her own child to be nursed in the country, at a considerable distance from her new residence. The account of an alarming illness with which it had been seized was communicated to her; and almost immediately it was apparent that her milk disagreed with the infant at her breast: it was regularly rejected by vomiting; and for several days a degree of disturbance of the system was maintained, not to be accounted for on any other supposition, than that here alleged. At length, when favourable tidings of her own child restored the nurse to her usual tranquility, the infant shewed no further signs of disorder. 
Inebriety which so powerfully deranges all the secretions is most pernicious in a wet-nurse. An excellent writer (North) on the convulsions of children, assures us, that he has known convulsive attacks in infants to originate solely from this habit in their nurses, and to subside as soon as the infants were provided with fresh breasts. Indeed I am inclined to believe from what I have observed in my intercourse with the poorer classes, that one considerable cause of the mortality of infants within their first year, in large towns, is the practice of drinking ardent spirits so common among females; a practice, when we consider its great prevalence, that more than any other, shews the demoralizing influence of crowded communities on the inferior grades of society.
 Underwood reports on the authority of Dr. Neilson, that out of 4,400 women who had suckled their children, only 4 had milk sores; and these had either no nipples, or had suffered from sore breasts on former occasions. Indeed so numerous are the inducements to suckle, that the wonder is, they are ever resisted except in cases of absolute necessity. In allusion to this subject, Mr. Roscoe, the elegant translator of Tansillo, remarks that "the reason generally assigned by medical men for promoting a custom which has of late (A.D. 1798) received their almost universal sanction, is, that the mode of living which now prevails in the higher ranks, is such, as renders it impossible for a woman to afford her infant those advantages which are indispensibly necessary to its existence and support." Surely medical men do not at present foster a practice so opposed to natural instinct and common sense. In the middle ranks of life it is little known, I mean as a luxury: -- and even in the higher, I imagine it is confined to the incorrigibly gay -- a class, from whose conduct, in justice to the sex, no inference ought to be drawn.
 An instance is mentioned, in an early volume of the Annual Register, of an infant that lost its mother on ship-board and was suckled by a goat. By some French writers the sheep is particularly recommended for this purpose. "The great advantage of this method of nursing infants having determined the Governors of the Hospital at Aix to adopt it, one might see each sheep, at the hour of suckling, recognize the nursling confided to her, shew it signs of great attachment, and put herself in the most favourable position for yielding her suck." Gardien de l'education des enfans
 Vol. 1, page 227.
 The following sketch in verse is fine, but perhaps it scarcely equals the above in prose.
"Chuse one of middle age, not old nor young,
Nor plump, nor slim her make, but firm and strong:
Upon her cheek, let health refulgent glow
In vivid colours, that good-humour shew:
Long be her arms, and broad her ample chest;
Her neck be finely turn'd, and full her breast:
Let the twin hills be white as mountain snow,
Their swelling veins with circling juices flow;
Each in a well projecting nipple end,
And milk in copious streams, from these descend:
Remember too, the whitest milk you meet,
Of grateful flavour, pleasing taste, and sweet,
Is always best; and if it strongly scent
The air, some latent ill the vessels vent."
St. Marthe's Poedotrophia: trans. by Dr. Tytler
 In the case of a nurse subject to nervous affections, reported by Dr. Clarke of Dublin, the milk was found one day to be almost colourless. In two hours after, a second quantity drawn from the breast was ropy like white of egg: several hours elapsed before the milk recovered its proper colour. These changes it was found, were occasioned by her having had hysteric fits in the meantime.
 Since writing the above I have had occasion to observe the milk of a phthisical patient and to watch its effects on her infant. The milk, in its sensible properties, was all that could be desired. The infant, which was nearly a month old, had been nourished almost entirely at the breast, and appeared in perfect health; this I confess was what I did not expect, as the mother had all the symptoms of tubercular consumption, and died about six weeks after delivery in a state of extreme emaciation.
 Dr. Struve's ale posset is said to answer excellently. "Two parts of rich cow's milk are placed over a slow fire; when it begins to boil, one part of well fermented mild ale is added, and the whole gently boiled for another minute. This mixture should be drunk cold."
 The following instructive case is from "Rosenstien on the diseases of children."
"A child perfectly fresh and healthy, and having also a healthy and cheerful nurse, thrived always very well in town; but when it was sent to pass the summer in the country it was observed to become weak and sickly every Sunday. I could not conceive the reason of this, thinking the nurse lived on Sundays, the same as on other days: she never got brandy to my knowledge as is customarily given in Sweden to other servant women. At last I found that some of her fellow servants gave her part of the brandy. This being prevented the child was as well on Sundays as on other days."
 "It has been remarked, that infants receiving the mother's breast after a violent fit of anger, are so immediately affected, that the white of their eyes acquires a yellowish colour. And the celebrated Haller relates a case of a child that was suckled during a paroxysm of great mental perturbation, and instantly after was seized with a hemorrhage from the nose and mouth; nay, convulsions gripes restlessness &c. are the general effects which follow a conduct equally rash and imprudent." -- Struve on the domestic education of Children.