In a previous communication,1 we reported the influence of breast and modified cow's milk on the excretion of certain volatile acids in the feces of nurslings.
We found the excretion of the volatile fatty acids to be relatively constant in infants given breast milk and extremely variable in those fed on cow's milk. It was also apparent that on the average the stools of infants given cow's milk were much heavier than those of infants fed on breast milk and that the excretion of acid seemed to bear a closer relation to the weight of the former than to that of the latter. The striking feature was the finding of propionic acid in the feces of normal infants who were artificially fed. Almost without exception, propionic acid seemed an index of feeding with cow's milk.
In this work, we were glad to be able to confirm the observations of