The first milk looks like ordinary milk (breast milk), or if the baby is being fed from the bottle, it looks just like the mixture in the bottle. It not only looks like what it took, but it smells just like it. Now examine the other; we find it looks like curdled milk, it is lumpy, and we immediately can tell that it is sour, because it smells sour and looks sour.
The explanation of the first overflow (immediately after the feeding) was the too great quantity; the explanation of the second overflow (one-half hour or so after the feeding), is the wrong quality of milk. The quantity was right because none overflowed right after the feeding, but the quality was wrong. Again, it is not the baby's stomach that is at fault,—it is the quality of the milk.
How do we know this? Because of what takes place in the baby's stomach during the one-half hour between the feeding and the time of the overflow of the sour milk. The quantity being right, why should the baby have any trouble if the quality is correct? It should not. Therefore by changing the quality (not the quantity as in the former case) we cure the trouble, thus proving the quality of the milk to be at fault.
What took place in the baby's stomach in the intervening half hour? The quality being wrong, the little stomach could not digest the mixture quick enough. Fermentation set in, gas was evolved, and as the stomach was full before the gas was manufactured (and as more and more gas is manufactured when food ferments), the stomach overflowed and out of the baby's mouth comes gas, and sour, fermenting, curdled milk. This process goes on until fermentation stops, or until the little stomach has just enough left to fill it and no more. But think what this is,—a sour mass of rotting, indigestible, curdled milk,—and that is what this baby is expected to live and thrive on.
Some babies seem to have trouble from the very first day of life. Either they will not retain the food, or the food fails to agree with them. If the baby is put upon artificial food at once, these troubles are, of course, not unexpected (because the right artificial food may not be first chosen for the particular baby), but it is not always the artificially fed baby that gives us trouble, and it is sometimes difficult to find the cause for such trouble in a baby who has had nothing but its mother's milk since it was born.
The cause of stomach trouble in a baby a few days old, fed exclusively on mother's milk, is invariably to be found in the quality of the milk.
The quality of the mother's milk may be affected in a number of ways which will render it unfit for the baby. For example, if the mother for any reason becomes sick, and has a high fever shortly after confinement, it will affect her milk and render it unfit temporarily.
If the mother worries or becomes highly nervous during the first few days of her baby's life, she will so affect her milk as to render it unfit for baby. If a baby is fed for a number of days after its birth by its mother, and it should prove afterward that she has not enough milk to continue feeding it, and has finally to put it on artificial food, the baby will most likely have acquired slight stomach ailments that may be troublesome for some time, because in this case both the quality and the quantity were no doubt wrong. Constipation in the mother will also cause trouble. The child will develop colic and extreme irritability until the mother's condition is relieved.
Each of these conditions affecting the milk of the nursing mother usually demands a change of food for the baby, and the substitution of the proper artificial food will invariably immediately correct the trouble. In some cases, however, the quality of the mother's milk is not dependent upon a temporary temperamental condition, but is caused by errors in diet, or conduct, or both. The milk of a physically tired, worn-out mother, is not good, no matter whether the exhaustion is caused by actual physical labor or by the exactions of a strenuous social programme. The milk of a mother who persists in eating irregularly, or who willfully caters to an appetite which craves the rich, highly seasoned articles of diet, or who attempts to satisfy a legitimate hunger by drinking large quantities of stale tea or coffee and eating bread, is unfit for her baby.
These cases are amenable to the proper treatment, which of course means, that the mother must change her conduct if at fault, and live strictly upon the diet prescribed elsewhere for nursing mothers.