Today In Medical History – July 19

(1865) French mineralogist and crystallographer Georges Friedel is born. He is known for proving the physical capabilities of crystallography, a process which can be used to determine the structure of proteins.
(1865) American medical practitioner Charles Horace Mayo is born. He is one of the founders of the Mayo Clinic,  a non-profit medical practice and medical research group. He also specialized in nervous system and thyroid surgery.
(1881) Physicist and philosopher Friedrich Dessauer is born. He studied x-rays and their medical applications.