This section is from the "The Young Mother. Management of Children in Regard to Health" book, by William A. Alcott. Also available from Amazon: The Young Mother
On this point, there is a great diversity of opinion. Perhaps the most approved role, of universal application, is, that the first change should be made in the child's diet, when the teeth begin to appear.
This period, it is well known, cannot be fixed to any particular age, but varies from the fifth to the twelfth month.
Some mothers, who have borne with me patiently to this place, will probably here object. "What child," they will ask, "would ever have any strength, brought up so?" Not only a little pap and gruel is, in their estimation, necessary, long before this period, but even many choice bits of meat.
Now I am very sure, that these choice bits—whatever they may be—given to a child before it has teeth, not only do no good, but actually do mischief. Indeed, that which does no good in the stomach must do harm, of course; since it is not only in the way, but acts like a foreign body there, producing more or less of irritation.
I ought to state, in this place, that many people—mothers among the rest—have very inadequate ideas of digestion. They appear to have no farther notion of the digestive process than that it consists in reducing to a pulp the substances which are swallowed; and hence, whatever is reduced to a pulp, they regard as being digested. Whereas nothing is better known to the anatomist and physiologist, than that this—the formation of chyme in the stomach—constitutes only a very small part of the digestive process. The chyme must pass into the duodenum and other portions of intestine beyond the stomach, and be retained there for some time, before it will form perfect chyle.
This is a more important part of the work of digestion than even the former. For, suppose the chyme to be perfect, though even this may be mere pulp, rather than chyme, and suppose it pass quietly along into the duodenum and other small intestines. All this process, thus far, may go on naturally enough, and yet the chyle may not be well formed, and the chymous mass may find its way out of the system without answering any of the purposes of nutrition. For no matter how well the food is dissolved in the stomach, if it do not become good and proper chyle, the blood which is formed will not be good and perfect blood; or, lastly, if it seem to make good blood, it may still be faulty, so that the particles which should be applied to build up or repair the system, are either not used, or if used, answer the purpose but imperfectly.
We hence see how little prepared a large proportion of the community, are, to judge of the digestibility or fitness of a substance for infants, by their own observation and experience merely; and how much more wisely they act, in contenting themselves with giving them—at least until they have teeth—such food only as the Author of nature seems to have assigned them; especially when thus course, is precisely that which is recommended or sanctioned by nearly every judicious physician, as well as by almost all our writers on health.