152 
ANNUAL REPORT 
‘ 
plus the weight of the sediment subtracted from 5 grams will give the 
weight of all the particles finer than the one-minute sediment. The addi- 
tion of a drop or two of ammonia or boiling the water will usually de- 
flocculate any aggregate of clay particles. This mechanical analysis works 
especially satisfactorily with limestone, clay and raw cement mixtures and 
it is possible to carry out this analysis in one hour. 
SLES ILL LAS ASEM CEDAR UNIT 
BILLED TLL 
Fig. 13. 
Syphon and apparatus for analysis by sedimentation. 
Mechanical Analysis of Ground Cement.-—The same process may be 
carried out with ground cement, but in place of water some liquid not act- 
ing upon the cement must be used. Alcohol redistilled over caustic lime was 
