MAGNESITE

Giobertite ; native carbonate of magnesia, occurs in white, hard, stony ma es, in the presidency of Madras, and in a few other localities. It di olves very slowly in muriatic acid, and gives out carbonic acid in the proportion of 22 parts by weight to 42 of the mineral, according to my experiments, and is therefore an atomic carbonate. It forms an excellent and beautiful mortar cement for terraces; a purpose to which it has been beneficially applied in India by Dr. Macleod.