CARBON, BORON, SILICON, SELENIUM, SULPHUR, PHOSPHORUS.
This group of non-metallic elements has been frequently styled "Metalloids," meaning substances allied to, but not possessing, all the properties belonging to a metallic substance; and therefore perhaps the expression, non-metallic solids, is the best that can be adopted. They may be subdivided into two classes of three each, which have properties more or less allied to each other—viz.,
Carbon, Boron, Silicon; and
Selenium, Sulphur, Phosphorus.