It is the lack of a uniform health standard in children that gives to artificial feeding all its difficulties. It renders the successful artificial feeding of children a personal or individual problem. Some children,--those who approximate a standard of health for their age; in other words, "well" children,--thrive on a milk modification that experience has taught us is suitable for well children of their age. Others, and they are in the majority, have to be fed on a modification which actual test proves to agree with their digestive capabilities. Every artificially fed child therefore must be studied from its own individual standpoint. A certain modification of milk may not agree with a child fed every two and one-half hours, which will be found to agree if fed in the same quantity, to the same child, every three hours. The slightest change, a change which would seem to be so insignificant in itself as not to justify serious consideration, may mean the difference between normal healthfulness and constant ill health. A food that is too strong for a child's digestive ability, and which causes vomiting, colic, and diarrhea, may be rendered exactly right by the slightest modification one of its constituents. To effect such a change quickly and successfully, one must be trained to interpret the symptoms correctly and to know how to make the change in the modification of the milk. Mothers cannot be expected to possess this degree of skill: they should therefore refrain from experimenting, because an experiment on a baby is not only dangerous, but ethically it is criminal. Call the family physician; put the burden on his shoulder.