In January, 1910, my assistant Dr. George W. Brett and I undertook an investigation on the relative value of raw, pasteurized and boiled cow's milk as a food for unweaned animals. Experimental studies on this subject commonly have one or both of two weaknesses — the use of an insufficient number of animals and an inadequate period of time during which observations are made; hence Dr. Brett and I determined to use the largest number of animals we could properly handle and keep them under observation in all cases from birth until they died or reached adult life, and in some cases after they had reached adult life, to test their vital efficiency as far as this would be measurable by the number and vigor of their progeny during one year.
The animals selected for our investigation were guinea-pigs, as they were the only species of which a sufficient number
SCHROEDER EC. AN EXPERIMENT WITH RAW AND HEATED COW'S MILK AND ITS LESSON. WITH COMMENTS ON BACILLUS ABORTUS. Am J Dis Child. 1913;VI(5):334-343. doi:10.1001/archpedi.1913.04100350047004