1º_ Micrographic surgical procedure, by which cancerous tissue is removed in thin layers that are analyzed with a microscope, and the surgery ends when the layer already contains only healthy cells. It was created by physician Frederic Edward Mohs in 1938. 2º_ Name of a practical scale of hardness of materials, based on the ancient method "which mineral can scratch another", which has the values from softest to hardest compared with 10 materials: 1- talc, 2- gypsum, 3- calcite, 4- fluorite, 5- apatite, 6- orthoclase, 7- quartz, 8- topaz, 9- corundum, 10- diamond. It was created by geologist Carl Friedrich Christian Mohs in the first half of the nineteenth century.