21,4 Witt: Effect of Sulphur Compounds on Cement 359 
In the first paper it was pointed out that the percentage 
loss in tensile strength of the neat specimens, due to the highest 
concentration of sulphide, varied with the iron content of the 
cement. In general the same relationship persists after five 
years, as is shown in Table 3, though Cement B is an exception. 
TABLE 2.—The effect of calcium sulphate on tensile strength. 
[Pounds per square inch. Each value is the result of six tests.] 
NEAT. 
Sul- Neat. 1:3 standard Ottawa sand. 
anny: : 
5 an n n n 
Gee | Goo | eae) aie et} ere eT Se el 4 
ince- | @ a i} S $ $ aj S S $ $ 
mente | (3° Ioan 5 B > Ae ee & 5 > > 
Ld Nn ~* © ri fon} L ed Nn oO wo nm oO 
P. ct 
Aes 1.08 | 527] 680] 743] 648] 755| 715 | 226] 285| 877] 385} 415 | 400 
we Si 1.52 | 578 | 648| 788| 707| 766| 774| 216 | 288| 364] 411| 423/ 447 
ge eer 2.19 | 507| 631| 743| 769| 730| 580| 188| 309| 390] 413 | 447 /| 488 
an eed 2.81| 418| 623| 690| 778| 720| 687! 142| 250| 345| 375| 400| 417 
yas gee an 9.18 | 465] 593 | 697| 684| 749] 662| 142) 197] 226|) 201} 195 | 308 
Boece 1.14] 569] 612} 600} 594] 548| 4571 218/| 300| 333] 308| 326 | 379 
Bo cccesereures 1.59 | 535] 580| 584] 640] 606] 572/| 206] 282] 281] 281 302/| 850 
B ......----..| 1.89 | 553} 618| 685| 619| 576| 456, 268] 347/ 358| 828| 366 | 871 
Be 4.55 | 509] 584| 613} 610| 541/ 568] 136 $85 | 856 | 427 | 437 
B kssees 9.92 | 528| 602} 648| 677| 666| 693} 143] 187| 170| 150| 160 | 208 
Cac eal 384 |: B86. | STO once 680 | 695 |_.____ co Be 1 ae 450 | 394 
C....-.-------| 2.10} 586 | 650| 636| 650| 649| 570| 241) 351/| 409 | 398] 423 | 413 
O22 8.02 | 495 | 620| 687] 656] 684] 503| 218] 346| 426] 433] 501] 416 
Dor Scr ane 4.86 | 416] 569| 711} 623] 592] 665/| 128] 187] 182] 333] 414 | 484 
2 eon peace 9.54] 898) 491| 646] 688) 576| 555| 112] 170] 244| 164/ 171 | 192 
De a LB4i G88 | 728 [2 695 | 692 |__._.. 294} 409 |__.... 418 | 899 |__._. 
De: 2.14} 665] 629| 661| 649} 650| 577| 267/| 387| 480| 3890] 386 | 351 
5? Semana 8.380 | 648] 678 | 783} 693 | 697| 563] 261| 399] 469] 436]! 470 | 339 
jt Leama, 5.00] 455] 672] 628| 716] 686| 553/| 161] 282/ 470| 456 | 473 | 368 
Dia a 10.20| 425] 658 | 644] 696/ 596| 474] 149] 218] 229] 187/] 156 | 113 
yc rears Sree 10h) OS 1 EL i] OT 1 6 [cs 831 | 407 438 | 867 
p PEDERI S 2.05 | 681/ 664] 639] 655| 684| 458| 276] 3884] 899| 3859] 403 | 401 
Fea! 2.73 | 692| 682] 751| 615| 618| 618| 829| 875 | 443| 395| 441 | 415 
y  patnlese rr 4.79 | 465| 531] 662] 695| 691| 640} 184| 408] 512] 462) 505 | 462 
tA A nen 9.58 | 413] 517| 599| 686) 540] (*) | 187] 162} 154) 118| 98} (*) 
b BEE EE aN Se 1.46 | 650| 628] 603] 704) 645| 655| 217| 816) 361| 3878] 388 | 347 
| goon ee 2.00| 768/ 814/ 831| 840| 760) 818] 181| 268| 317| 368| 854 | 311 
fo 8.29| 674/ 713| 785| 781| 776| 695| 233] 330] 389| 359] 369} 382 
b G Seqinr neat 5.00 | 421| 648] 623] 660] 698| 758| 194] 331 | 407] 444| 465 | 406 
rat agree Paes 9.11 | 385] 489| 654| 591] 611] 578] 157| 317| 4380 404 | 314 
« These specimens were swollen, cracked, and partly disintegrated, and could not be tested. 
The identification marks on five-year briquettes of the calcium 
sulphate series were illegible when the specimens reached 
maturity, so the three-year results are the last that can be 
considered. Table 2 shows that, for the three-year period, the 
presence of as much as 5 per cent of sulphuric anhydride did 
