Frederick Banting upon the idea of obtaining insulin from the fetal pancreas. He removed the pancreases from fetal calves at a William Davies slaughterhouse and found the extracts to be just as potent as those extracted from the dog pancreases. By December 1921, he had also succeeded in extracting insulin from the adult pancreas. Pork and beef would remain the primary commercial sources of insulin until they were replaced by genetically-engineered bacteria in the late 20th century. In spring of 1922, Banting established a private practice in Toronto and began to treat diabetic patients. His first American patient was Elizabeth Hughes Gossett,
Highest and best use of the land as vacant exceeds the value of the property as improved less reversion/demolition costs, then redevelopment of the site becomes the maximally productive use of the property, and continued use of the existing improvements that do not represent the highest net value of the site is considered to be financially unfeasible. Finally, the use must generate the highest net return (profit) to the developer. A property that could hypothetically be developed with residential, commercial or industrial development might only have one of those uses as its highest and best use. These three hypothetical development scenarios follow to illustrate