Note 47 — Chapter XIV · THE VALENCY AND SPECIFIC HEAT OF THE METALS. MAGNESIUM. CALCIUM, STRONTIUM, BARIUM, AND BERYLLIUM
George Kamensky translation
According to Le Chatelier (1888), 1½H2O is lost at 120°—that is, H2O,2CaSO4 is formed, but at 194° all the water is expelled. According to Shenstone and Cundall (1888) gypsum begins to lose water at 70° in dry air. The semi-hydrated compound H2O,2CaSO4 is also formed when gypsum is heated with water in a closed vessel at 150° (Hoppe-Seyler).