values of the uncorrected optic axial angle ( 2h ( alpha ) ) of a crystal of the calcium zeolite stellerite ( caal ( 2 ) si ( 7 ) o ( l8 ) . 7h ( 2 ) 0 ) immersed in calcium chloride solutions of known activity of water ( a ( w ) ) are directly proportional to log a ( w ) .
C0006675
calcium
C0006686
calcium