However delicate the frame may be in infancy, it is yet less sensible of cold than during any other period of life. As the pulse of infants is more quick than that of adults, it may, from this circumstance alone, be concluded, that the internal heat is proportionally greater. On the same principle it is hardly to be doubted, that of this heat small animals have a greater share than the large; it has invariably been found, that, in the same degree the animal is small, the motion of the heart and arteries is proportionally vigorous and quick; and this is ever the case in the same as well as in different species. The pulse of an infant, or of a man of small stature, is more frequent than that of a grown person, or a man of a large size. The pulse of an ox is slower, and a dog quicker than that of a man; and so precipitate are the motions in the heart of an animal still smaller, as a sparrow, for instance, they can hardly be counted.
Till the age of three years the life of an infant is highly precarious. In the course of the ensuing two or three years, however, it becomes more certain; and at the age of six or seven a child has a greater probability of living than at any other age. By consulting Simpson’s tables of the degrees of mortality, at different ages, as applicable to London, it appears, that, of a certain number of children, born at one time, above a fourth of them died in the first year, above a third in two years, and, at least, one half in the first three years. If this calculation is just a wager might be proposed, that an infant, when born, would not live three years. A man who dies at the age of twenty-five is to be lamented for the short duration of his life; and yet, according to these tables, one half of mankind die before the age of three years, consequently, every individual who has passed his third year, far from repining at his fate, ought to consider himself as treated with superior favour by his Creator. But this mortality in children is by no means so great in every place as in London. M. Dupré de St. Maur has proved, by a number of experiments made in France, that one half of the children born at the same time are not extinct in less than seven or eight years. By these experiments it is also shewn, that at the age of five, six, or seven years, the life of a child is more certain than at any other age, and that an equal bet may be laid for 42 years more, whereas in proportion as a child lives beyond five, six, or seven years, the probable number of years it will live decreases. At twelve years, for instance, the equal chance is only for 39 years; at 20, for 331/2; at 30, for 20; and thus forward, till the age of 85, when there is an equal chance of living three years longer.[A]
[A] In the course of this volume we shall present our readers with a table, at large, of the different probabilities of human life.
There is one thing very remarkable in the growth of the human body. The fœtus in the womb continues to increase more and more in equal periods, till the birth. The infant, on the contrary, increases less and less, that is in the same period of time, till the age of puberty, to which it seems to bound, as it were, at once. The fœtus, for example, is an inch long in the first month, two inches and a quarter in the second; three inches and a half in the third; five inches and upwards in the fourth; six inches and a half, or even seven inches, in the fifth; eight inches and a half, or nine inches, in the sixth; eleven inches, in the seventh; fourteen inches, in the eighth; and eighteen inches, in the ninth. Although this measurement may vary in different children, yet if the child be 18 inches at its birth, it will hot increase more than six or seven inches in the first year after: that is, at the end of the first year, it will be 24 or 25 inches; of the second, 28 or 29 inches; of the third, only 30, or, at most 32 inches; and from this age till that of puberty, it will not advance more than one inch and a half, or two inches, in the course of each year. From these remarks it is evident that the fœtus increases more in a month, towards the close of its residence in the matrix than the infant does in a year, till it arrives at the age of puberty; when Nature seems to make one grand effort to unfold the animal machine, and render her work complete.
So essential is it, that the constitution of the nurse should be sound, and her juices untainted that we have many instances of diseases being imparted from the nurse to the infant, and from the infant to the nurse. Whole villages have been infected with the venereal virus, by nurses suckling the children of other women.
Were mothers to suckle their own offspring it is probable the latter would be more strong and vigorous. The milk of a stranger must be less proper for them than that of the mother, for as the fœtus is nourished in the matrix by a fluid, which bears a strong resemblance to the milk that is formed in the breasts, the infant, therefore, is already, as it were, habituated to the milk of its mother. The milk of any other woman, on the contrary, is a nourishment new to the child, and sometimes so different from the other that it is difficult to make the child take it: and if forced will sicken and languish, from not being able to digest the milk of the nurse; a circumstance which, if the consequences are not seasonably prevented by the substitution of another nurse, soon proves fatal.
I cannot help observing, that the custom of crowding a multitude of children into one place, as in the hospitals of large cities, is highly repugnant to what ought to be the grand object proposed, their preservation. The greatest part of such children fall victims to a kind of scurvy, or to other diseases, from which they might have been exempted, had they been brought up in different houses, or rather in the country. The same expence would be sufficient for their support, and an infinity of lives, in which it is well known consist the real riches of a state, would be saved.
At twelve or fifteen months infants begin to lisp. A is the vowel which they articulate with most ease, as it requires nothing more than the opening of the lips, and forcing out the breath. E requires that the tongue should be raised as the lips are opened; and is therefore pronounced with a degree of more trouble. I is attended with greater difficulty, as in the articulation of the vowel the tongue is elevated still more, and made to approach the teeth of the upper jaw. In the pronunciation of O, the tongue must be lowered, and the lips contracted; and in that of U, the latter must be also contracted, and in some degree extended. The first consonants which children pronounce are those which require the least motion in the organs. Of these the most easy of articulation are B M and P. For that of B and P it is simply requisite that the lips should be closed and then opened with quickness, and for that of M, that they should be first opened and then closed with celerity. The articulation of the other consonants supposes motions more complicated. The pronunciation of C D G L N Q R S and T depend each on a particular action of the tongue, which it would be very difficult to explain; and for the pronunciation of F, a more continued sound is necessary, than for that of any other consonant. A being the most easily articulated of the vowels, as are B P and M, of the consonants, we need not wonder that the first words which children pronounce, in every country, should be composed of, that vowel, and of those consonants; and that, for example, in every language, Baba, Mama, Papa, should be the primitive articulations. They are the most familiar sounds to man, and the most natural to him, because the most easily pronounced, and the letters of which they are composed must exist wherever there is any typical mode for the denotation of sounds.
It is to be observed, however, that as the sounds of several consonants are nearly similar; those, for instance, of E and P, of C and S, of K and Q, in certain cases; of D and T, of F and V, of G and J, of G and K, of L and R, so there may be many languages in which such consonants are not to be found. But in every language, there must be a B or a P, a C or an S, a K or a Q, a D or a T, an F or a V consonant, a G or a J consonant; an L or an R, and in the most contracted of all alphabets, there cannot be less than six or seven consonants, for of that number there are simple sounds, which have all a very sensible difference from each other. Those children who do not readily articulate R, substitute L for it; and in the place of T they articulate D. Indeed L and D require more difficult movements in the organs than either R or T; and it is from this difference, and from the choice of consonants more or less easy of articulation, that the softness or the harshness of a language proceeds. But on this subject it would be superfluous to enlarge.