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 both "as improved" and "as if vacant". Vacant properties are generally only given the "as vacant" test. The Highest and Best Use as vacant may be the same or different as the Highest and Best use as improved. For improved properties, the first analysis applied is the use of the property based on the assumption that the parcel is vacant. Then, the analysis focuses on the use that should be made of the property as it is currently improved. The extent to which the existing improvements differ from the highest and best use as-if vacant, reveals the extent of any