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 the site is to demolish the house and sell the site as a commercial lot. The market value would be $225,000 ($250,000 site value minus $25,000 demolition cost). However, if the demolition costs rose to $55,000, the highest and best use would be the existing residential use, because the value as a commercial lot (now $195,000) would not exceed the existing value as a residence. This would be the highest and best use of the property, even though it is contrary to what actually exists. Even if the house is not razed and the site sold as a commercial lot,