Friedrich Mohs harder. This became the basis of the hardness scale developed by Mohs. The hardest mineral, diamond was given a value of 10 and softer minerals such as talc were given the very low value of 1 (unity). Other minerals were given intermediate values, depending on their ability to scratch another mineral in the scale. Thus gypsum was given the value 2 because it will scratch talc crystals, and calcite the value 3 because it will scratch gypsum. Minerals are also now classified by chemical characteristics, but the physical properties are still useful in field examination. In 1812, Mohs became a
Frederic E. Mohs a boarding house. After initially considering a career as a radio engineer, he switched to medical studies in college. Mohs began developing his treatment in the 1930s, experimenting on rats, puppies, and other animals. The breakthrough came when he discovered that applying a combination zinc chloride and bloodroot paste to malignant rat skin tissue allowed it to be removed surgically and examined under a microscope. He treated his first human patient on June 23, 1936. Mohs spent his working life at the University of Wisconsin. Mohs first tried to publish his findings and encouraged surgeons to learn the procedure. This