| Formula | Fat | Sugar | Proteins |
| I | 0.70 | 5.00 | 0.35 |
| II | 1.00 | 6.00 | 0.50 |
| III | 1.40 | 6.00 | 0.70 |
| IV | 1.75 | 6.00 | 0.87 |
| V | 2.00 | 6.00 | 1.00 |
| VI | 2.40 | 6.00 | 1.20 |
| VII | 2.80 | 6.00 | 1.40 |
| VIII | 3.10 | 6.00 | 1.55 |
| IX | 3.50 | 6.00 | 1.75 |
It is necessary to make the food weak at first because the infant's stomach is intended to digest breast milk, not cow's milk; but if we begin with a very weak cow's milk the stomach can be gradually trained to digest it. If we began with a strong milk the digestion might be seriously upset.
Usually we begin with number one on the second day; number two on the fourth day; number three at seven to ten days; but after that make the increase more slowly. A large infant with a strong digestion will bear a rather rapid increase and may be able to take number five by the time it is three or four weeks old. A child with a feeble digestion must go much slower and may not reach number five before it is three or four months old.
It is important with all children that the increase in the food be made very gradually. It may be best with many infants to increase the milk by only half an ounce in twenty ounces of food, instead of one ounce at a time, as indicated in the tables. Thus, from three ounces the increase would be to three and one-half ounces; from four ounces to four and one-half ounces, etc. At least two or three days should be allowed between each increase in the strength of the food.
PEPTONIZED MILK
Another modification which at times may be ordered by your physician is peptonized milk. Since it is infrequent for the proteins of milk to be the cause of indigestion, peptonized milk has only a limited use, chiefly in cases of acute illness. The milk is peptonized in the following manner:
Place the peptonizing powder (it is procurable in tubes or tablets from the drug store) in a small amount of milk, and after being well dissolved, put into the bottle or pitcher with the plain or modified milk, after which the whole is shaken up together. The bottle is then put into a large pitcher containing water heated to about 110° F. or as warm as would bear the hand comfortably, and left for ten or twenty minutes (if the milk is to be partially peptonized). To completely peptonize the milk, two hours are required. Either of these formulas is only used on the advice of a physician.
BUTTERMILK
In many cases of chronic intestinal indigestion, buttermilk is used in place of the milk. It is prepared as follows: After the cream has been taken from the milk and it has been allowed to come to a boil, it is cooled to just blood heat. A buttermilk tablet, having first been dissolved in a teaspoonful of sterile water, is now stirred into the quart of warmed, skimmed milk and allowed to stand at room temperature for twenty-four hours at which time it should look like a smooth custard. With a sterile whip this is now beaten and is ready for the sugar and the boiled water which is added according to the written prescription from the doctor.