Two important scientific articles concerned with the feeding of infants have appeared in The Journal of the American Medical Association, "Peptic Digestion of Cow's Milk," by Hess, Koch and Sennewald,1 and "Protein Digestion in Infancy," by Ernst Freudenberg.2 In order to add a little, if possible, to the information reported in these articles, this comparative study of the effect of various modifications of cow's milk on peptic digestion in vitro has been made. Milk mixtures not previously reported on have been included. Diluted feedings rather than whole milk have been used, with conditions set near the optimum for peptic activity. Increase of milligrams of amino-nitrogen resulting from peptic digestion has been ascertained and the increase per gram of protein calculated as the basis of comparison for digestion by pepsin. The feedings listed have been made up and digested with pepsin.
Unless otherwise stated, ordinary pasteurized mixed Holstein Ayrshire