32 The Philippine Journal of Science lais 



Calcium sulphate. Chandlot, Journ. Soc. Chem. Ind. (1889), 8, 543. 

 The set is retarded. 



Calcium sulphate. L. Deval, Journ. Soc. Chem. Ind. (1902), 21, 971. 



It produces a change of form and an increase in volume with a tendency 

 to diminish the tensile strength. It has no effect on nonaluminium 

 cements nor on those low in calcium. 



Calcium sulphate. R. C. Carpenter, Eng. Rec. (1904), 50, 769. 



The maximum setting time was obtained with an addition of 1.5 per 

 cent. 



Calcium sulphate. P. Rohland, Zeitschr. f. angew. Chem. (1905), 18, 327. 

 The effect varies for nearly every cement, depending on the size of 

 grain, the chemical composition, etc. 



Calcium sulphate. L. Perin, Journ. Soc. Chem. Ind. (1906), 25, 812. 



Plaster of paris and raw gypsum (containing equivalent amounts of 

 sulphuric anhydride) have the same effect. 



Calcium sulphate. Spiegelberg, Journ. Soc. Chem. Ind. (1909), 28, 1131. 

 The effect varies from the composition of the cement. 



Calcium sulphate. W. C. Reibling and F. D. . Reyes, Phil. Journ. Sci., 

 Sec. A (1911), 6, 225. 

 The maximum retardation is produced with 2 to 3 per cent of calcium 

 sulphate. 



Calcium sulphate. 0. Kallauner, Z. Betonbau (1914), No. 2; Mitt. Cent. 

 Ford. Deut. Port. Cement Ind., 3, 213. [Chem. Abst. (1914), 8, 

 2236.] 

 Temporarily the strength is increased. 



Calcium sulphate. J. C. Witt, and F. D. Reyes, Phil. Journ. Sci., Sec. A 

 (1917), 12, 133. 

 Six brands of cement were tested with additions of calcium sulphate. 

 In general, the maximum retardation of set was produced by 1.5 to 

 2 per cent sulphuric anhydride. Lower tensile strength and high 

 expansion in sea water resulted when more than 3 per cent was 

 present. 



Calcium sulphide. N. Ljamin, Journ. Soc. Chem. Ind. (1902), 21, 972. 



Calcium sulphide forms an insoluble compound with calcium hydroxide, 

 but the effect is relatively low, because about 3 parts of the sulphide 

 are required to combine with 1 part of the hydroxide. 



Calcium sulphate. O. Kallauner, Z. Betonbau (1914), No. 2; Mitt. Cent. 

 Ford. Deut. Port. Cement Ind., 3, 213. [Chem. Abst. (1914), 8, 

 2236.] 

 Temporarily the strength is increased. 



Calcium thlosulphate. O. Kallauner, Z. Betonbau (1914), No. 2; Mitt. Cent. 

 Ford. Deut. Port. Cement Ind., 3, 213. [Chem. Abst. (1914), 8, 

 2236.] 

 Temporarily the strength is increased. 



