M – Milk 

At the turn of the 20th century, cow’s milk, a staple of American children’s diets, had also become recognized as a common source of diseases, such as tuberculosis. This concern was so great at the time that Boston Children’s Hospital maintained its own special herd of cows in the field across Longwood Avenue from the Hunnewell building. Their milk ensured a safe, disease-free supply for the hospital young patients. 

Further, pediatrician Dr. Thomas Morgan Rotch and his colleagues believed they could improve milk scientifically, and established a milk laboratory at the nearby Infants’ Hospital for research and clinical use. Rotch insisted on pure, quality milk and a well-managed laboratory to ensure the accurate composition of the formulas called for in his “percentage feeding method.” Looking at the analyses of human milk that were available, Rotch devised the following mixture using pure cow’s milk: “1/4 part cream, 1/8 part milk, 1 part water, and 1 measure (3 3/8 drams) of lactose and 1/6 part limewater for each 8 ounces of mixture.” 

Dr. Rotch soon found, however, that no one formula was suited to all infants which led him to develop a complex system, with variable percentages of protein, fat and carbohydrate. The percentage feeding method was commonly used in the United States from 1890 until around 1915. 

Eventually, pasteurization, the process by which milk is heated in order to kill the bacteria that can spread disease, became commonplace across the country, these protective methods became obsolete. By the 1930s, the famous “Hunnewell cows” who grazed on Longwood Avenue were gone. Although Dr. Rotch’s percentage feeding method lost favor, he clearly demonstrated the necessity of clean milk in infant feeding – noted as one of the greatest pediatric achievements of his time.