280 



The Philippine Journal of Science 



1916 



for the same periods, except the one day. This paper covers 

 only the results obtained during the first sixty days. The other 

 briquettes are properly stored and will be broken when due. 

 The results so far obtained are given in Table V. 



Table V. — Effect of sodium sulphide on the tensile strength." 



NEAT CEMENT. 



1 day 



7 days 



28 days. 



60 days. 



Brand. 



Kilos per square centimeter. 



Solution. 



Water. 



4 



3 



2 



24.8 



21.5 



21.1 



10.8 



28.6 



28.8 



27.3 



23.9 



23.2 



28.9 



28.5 



24.9 



24.5 



23.5 



21.7 



15.1 



27.3 



23.5 



23.9 



15.6 



41.8 



41.2 



35.4 



21.1 



43.5 



43.7 



40.8 



33.3 



41.2 



40.5 



40.0 



32.3 



44.5 



41.3 



39.0 



32.7 



44.2 



44.9 



42.9 



31.9 



48.1 



45.1 



38.6 



40.3 



45.7 



42.9 



42.2 



39.8 



47.8 



44.4 



42.5 



31.7 



50.7 



50.9 



46.0 



44.3 



51.3 



51.6 



45.3 



41.4 



47.3 



42.5 



38.0 



39.4 



45.7 



43.5 



40.8 



40.1 



45.3 



46.7 



47.4 



35.3 



47.5 



48.1 



45.1 



40:8 



50.6 



47.4 



42.3 



41.5 



13.3 



18.4 

 23.9 

 17.9 

 18.9 

 18.9 

 32.3 

 30.4 

 38.9 

 36.5 

 27.4 

 34.7 

 28.8 

 41.2 

 37.9 

 28.4 

 36.8 

 28.1 

 41.1 

 36.1 



Pounds per square inch. 



Solution. 



Water. 



4 



3 



2 



363 



807 



800 



155 



337 



411 



388 



340 



330 



412 



407 



355 



348 



335 



308 



214 



388 



334 



340 



222 



595 



686 



506 



300 



617 



622 



579 



475 



586 



577 



568 



461 



633 



687 



554 



467 



628 



638 



609 



456 



685 



6J2 



548 



573 



651 



611 



599 



567 



679 



632 



605 



452 



722 



726 



655 



630 



731 



736 



645 



588 



673 



606 



542 



560 



649 



618 



581 



569 



644 



666 



676 



503 



677 



685 



642 



681 



720 



676 



602 



589 



190 

 262 

 341 

 255 

 268 

 268 

 460 

 433 

 653 

 519 

 391 

 495 

 410 

 684 

 639 

 406 

 526 

 400 

 584 

 516 



MORTAR. 



7 days 



28 days- 



60 days. 



A 



B 



C 



D 



E 



A 



B 



C 



D 



E 



A 



B 



C_ - 



D 



E 



16.8 

 17.5 

 19.8 



14.8 

 16.4 



17.8 



12.2 

 16.2 

 17.6 



16.5 

 12.2 

 12.2 



5.2 

 10.1 

 11.8 



238 

 248 



282 



209 

 233 

 263 



174 

 230 

 248 



234 



174 

 174 



20.8 



16.9 



16.9 



11.3 



10.1 



294 



239 



240 



162 



23.2 



18.6 



26.2 



12.6 



10.9 



331 



265 



374 



179 



23.4 



20.5 



16.6 



16.9 



8.7 



333 



292 



237 



240 



21.7 



19.7 



18.2 



17.7 



15.4 



308 



280 



268 



252 



26.7 



25.0 



21.4 



10.8 



17.6 



380 



357 



305 



155 



28.8 



24.1 



23.2 



16.6 



16.8 



409 



343 



329 



237 



28.5 



22.5 



21.4 



19.7 



16.9 



407 



319 



304 



279 



25.3 



21.1 



22.5 



19.9 



18.2 



360 



299 



320 



283 



22.8 



28.1 



26.8 



20.4 



18.3 



325 



399 



382 



290 



30.1 



22.4 



20.4 



14.3 



10.9 



428 



318 



290 



205 



30.9 



26.9 



24.5 



20.3 



18.6 



441 



383 



348 



288 



29.1 



24.2 



24.6 



18.7 



17.6 



414 



344 



351 



267 



74 

 146 

 168 

 144 

 157 

 124 

 218 

 251 

 226 

 227 

 258 

 259 

 167 

 265 

 249 



» Each result shown is the average of six briquettes. 



A comparison of the results reveals that there is a considerable 

 decrease in strength, caused by sulphide solutions. In general, 



