358 The Philippine Journal of Science 1922 
TABLE 1.—The effect of sodium sulphide on tensile strength—Continued. 
1:3 STANDARD OTTAWA SAND. 
a2 n 
aL a Pa ia] n mn a 
Cement. - ome » b a a 3S % z z g g 
ries HESS PETRA 2S 
A pitisties eee (a) ..----| 238 |, 883 | 860] 878| 899| 383) 882] 420] 881 
G asebechi eget aeeeye ern s 0007 fc. 209 | 292 | 299) 356 | 337] 383) 323) 390 | 349 
7 Yeohixgae ease eer ese: OVE pss. - 174 | 287| 320| 833) 346) 331) 365) 427 | 376 
Bo weuckcus Sea esewees 4. fessm8 234 | 240} 288 | 259| 259} 268] 305| 876 | 885 
eS $270: {2 124| 124| 258| 204] 246) 243| 256| 311 | 297 
B > C5 ee eee 248 | 308] 3825| 319| 323} 284] 380] 382 /| 329 
p ; Pee etewees yet alrueee et 0007 |xa.--. 233 | 280} 399} 309| 305) 304| 320/ 346 | 315 
b: en arenes ae, Oe OcOT c[Sentee! 280 | 258 | 382 | 3805| 304| 309] 323| 871 | 805 
Be ee 400 to 174| 252 | 290) 279| 277) 263] 292) 389) 311 
4, Gener cee  aNRaen so 145 | 218 | 259| 266| 253 | 257| 257) 824 | 296 
C..-. ----------------=" (@). |------ 282 | 380 | 428| 402} 450) 394) 425| 451 | 417 
OG. So a 0.097 |------ 253 | 357] 3818) 401| 482| 452 | 3842) 361 | 425 
|} jae Gene eer ens 0.97 248 | 3805 | 290] 410| 393] 3873] 402] 878 | 884 
Cc We: 4.80 [asks 174| 155 |. 205] 855 | 306] 889| 845| 879 | 344 
ny RE eee ee ce eS ae ‘6 bse 168 | 251|. 157| 320| 339| 288} 383] 374 | 340 
D 22222-2222 520-552=4 Qo fees 294} 409} 441 | 402) 418 | 399| 886 | 420 | 374 
Dit Ais. sik: Re 0.097 |------ 239 | 843 883 | 881] 411| 896| 394] 425 | 393 
AS ore eS DOT p.cse: 240} 829} 348] 392] 408} 364| 405| 450 | 340 
L2G 1 4.80 |----- _ 162 | 237} 288} 319| 320| 827| 3823| 370 | 349 
1 i ea ey ee eg ee a PATG. joie. » 144 226 265 | 299; 292; 316) 350| 315 | 317 
B.S ae O55 hee. 331 | 407| 414) 402| 488 367) 842 |e 378 | 375 
BP al 05007 |-2e8.- 265 819} 844] 361] 368| 825| 339] 448 | 342 
Bis Sh O9F LAL: 874 | 304| 851] 359] 360| 885 | 385] 368 | 889 
WS seek a.00 |. 38s. 179 | 279| 267); 319} 317] 287} 307| 364 | 316 
a DO Lan. 157 | 227| 249| 271| 260} 261} 265| 9818 | 268 
- r 
8 Water. 
years ago. In connection with the first two papers, tensile- 
strength specimens were stored in water, to be broken at various 
periods up to five years. All of these specimens have now 
reached maturity and the results are given in Tables 1 and 2. 
The first two papers contained such details as the chemical 
analyses and physical tests of the cements, the amounts of sul- 
phide or sulphate added, and a discussion of the results obtained 
up to that time. Consequently this material will not be repeated 
‘here. : 
| The five-year periods in Table 1 show some interesting results. 
As shown by the early tests, concentrations of sodium sulphide 
not exceeding 1 gram of sulphur (as sulphide) per liter do not 
seriously affect the tensile strength; in fact, in most cases the 
strength is increased. With the higher concentration, however, 
the strength is lowered in every case. The maximum loss is 
82 per cent with the neat and 37 per cent with the mortar. 
\ 
