Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
When this study was made, penicillin was considered to be the best drug available for use in mastitis therapy. It was infused intramammarily in aqueous solution with each dose dissolved in about 50 cc. of water. The quarters were treated just after each regular milking until four doses had been given.
Maddy, Keith T.
"Studies and Observations on Bovine Mastitis. III. Penicillin Treatment of Mastitis,"
Iowa State University Veterinarian: Vol. 16
, Article 1.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol16/iss2/1