The possibility existed, they argued, that once the active ingredients in cannabis (such as THC Delta-9) were isolated and correct dosages established, cannabis could become a miracle drug. Twenty-nine years would pass, however, before American scientists could begin to even look into cannabis medicine again. THC Delta-9 was isolated by Dr. Raphael Mechoulam at the University of Tel Aviv in 1964 cannabis seeds. His work confirmed that of Professor Taylor of Princeton, who had lead the research and identification of natural THC Delta-9 precursors in the 1930s. Kahn, Adams and Loewe also worked with the structure of cannabis' active ingredients in 1944.