A substance is anhydrous if it contains no water, for example, salts lacking their water of crystallisation. The way of achieving the anhydrous form differs from one substance to another.
A partial solar eclipse at its peak at 3:37 p.m. in Mesa on Oct. 23, 2014. The eclipse was visible over most of North America and covered 44 percent of the Arizona sun. Michael Chow/The Republic.
A total solar eclipse will be visible Aug. 21 in a path that stretches from Oregon to South Carolina. Eclipse enthusiasts have already begun preparations for the rare event. Although it will be partially visible in Colorado, no part of the state is in the path of totality. The closest points to Colorado will be in Wyoming and Nebraska. The last solar eclipse to include North America in its path of totality occurred Feb. 26, 1979.