STATE GEOLOGIST. 367 
sieves two sizes of grain, a and b, are separated and carefully dried. Of 
each size 5 grams are taken and shaken in a dry Haradas separatory fun- 
nel with a mixture of methyl iodide and purified oil of turpentine. This 
mixture should have at 15° C. a specific gravity of 3.01. The methyl 
iodide before being used should be dried over calcium chloride and filtered 
through previously ignited Portland cement. A hydrometer may be used 
for determining the specific gravity of the liquid. A suction pump is now 
attached to the funnel and the particles are separated according to 
whether they are lighter or heavier than 3.01. | 
The light particles which float are: 
Me Coalmlean speciic, Sravity, IO. 
2. Gypsum, mean specific gravity, 2.33. 
3. Coal cinders, mean. specific gravity, 2.73. 
4. Natural cement, mean specific gravity, 2.60. 
5. Blast furnace slag, mean specific gravity, 2.94. 
The heavier particles which sink are: 
1. Portland cement, mean specific gravity, 3.10. 
2. Particles of slag, high in iron, or particles of metallic iron.: 
In unadulterated Portland cement the amount of light material 4s 
small and hence any large amount of matter floating in the liquid is to 
be regarded as suspicious. Chemical analysis, including the determina- 
tion of sulphide sulphur, will show whether the light material is natural 
cement or slag. . In both cases the separated particles will analyze much 
lower in lime than the Portland cement. The presence of sulphide will 
indicate that the inert matter is slag. 
In the following table some of the characteristics of natural cement 
and slag are indicated :* | 
: J Py | Eine Re q iB 
3 Bo Beene weg mares Sete 
Description. ot BS 5 Ze techa) 55 S 6 a3 ae. 
cS Ce serra Taine Bee | Base 
g % 8 lec. of deci-| 23> Megs | BoEs 
ie S py normal acid. Se Ghee Baie oo Se n BO 
BHydrauliclime A..| 2.441 | 18.26 | 20.23 | 21.35 TON O78 
eB Bilin Paladin 17.82 DPD SUB? 26.80 OB Bll.s} 
a Go ll Bawaw 19.60 L9R 72 19.96 0.98 AT .7 
WeatheredslagA..| 3.012 0.76 0.91 | 14.19 | 74.60 3.6 
‘t OBA Gl BeBe 1.92 0.70 13.67 60.67 B40) 
oh te Gl oi ite Pan hare I dbl 1.00 9.70 44.34 2.9 
Ground slag D..| 3.003 0.32 0.31 3.60 64.40 2.4 
‘ R 
re Oe Tibia I Panis 0.43 0.11 8:20 (h35 AU | Ze, 
* Meade, Hxamination of Portland Cement. 
