An investigation of the bacteriology of preparations of dried, powdered milk was undertaken in connection with the study of an epidemic of enteritis. This epidemic occurred in an institution in which infants received artificial feedings composed largely of dried protein milk.
Samples of preparations of dried milk in use in two institutions were obtained. Cultures were made from them in the following manner:
A previously unopened can of each preparation was unsealed, and 1 gm. of the powder was weighed out in a sterile container, a sterile spatula being used for handling the powder. The gram of powder was suspended in 10 cc. of sterile broth. One cubic centimeter of the suspension was transferred by means of a sterile pipet to another tube containing 9 cc. of sterile broth. Successive dilutions were made upt to 1:10,000. One cubic centimeter of each dilution was plated out in plain aga