“X-Ray Pioneer” David Harker Hand Written Letter On 4X6 Card. This item is certified authentic by Todd Mueller Autographs and comes with their Certificate of Authenticity. (October 19, 1906 February 27, 1991) was an American medical researcher who according to the. Was “a pioneer in the use of X-rays to decipher the structure of critical substances in the life process of cells”. He is also well known for HarkerKasper inequalities statistical relationships between the phases of. , which he devised in collaboration with John S. Harker made seminal discoveries in the field of chemical crystallography. His lab solved the structure of the pancreatic enzyme. The third protein structure ever solved by protein crystallography. Harker was a member of the. National Academy of Sciences. Director of the protein structure program at the. Polytechnic Institute of Brooklyn. Director of the Center for Crystallographic Research at. Roswell Park Cancer Institute. (RPCI), and the head of the crystallography division of. After retirement from RPCI in 1976, he joined the. Hauptman-Woodward Medical Research Institute. (HWI), then known as the Medical Foundation of Buffalo. He remained there until his death in 1991. His research interests while at HWI turned towards mathematical aspects of. Harker was awarded the. The item “X-Ray Pioneer David Harker Hand Written Letter On 4X6 Card Todd Mueller COA” is in sale since Monday, April 27, 2020. This item is in the category “Collectibles\Autographs\Science, Inventor”. The seller is “historicsellsmemorabilia” and is located in Fort Lauderdale, Florida. This item can be shipped to United States.