(2) A similar oxide (flores jovis) is produced by burning tin in air at high temperatures or exposing any of the hydrates to a strong red heat.
On solution in water, heat is evolved and hydrates formed.
Davy, inspired by his successful isolation of the metals sodium and potassium by the electrolysis of their hydrates, attempted to decompose a mixture of lime and mercuric oxide by the electric current; an amalgam of calcium was obtained, but the separation of the mercury was so difficult that even Davy himself was not sure as to whether he had obtained pure metallic calcium.
It forms hydrates containing one, two, five, six and seven molecules of water.
It forms several hydrates, the medicinal value of which was recognized in very remote times.