May 10,1924 Factors Influencing Binding Power of Soil Colloids 
511 
colloid, that if the load per gram of briquette varied directly as the amount of 
colloid present, the load per gram of colloid would be constant for each material. 
With quartz flour this is practically the case with the exception of the first 
determination (50 per cent colloid). With medium sand the variation is larger. 
It may also be noted that the variation in the load per gram of colloid, particu¬ 
larly with medium sand, follows more or less closely the density of the material 
as indicated by the weight of the briquette. 
Table VIII .—Showing the effect of the amount of colloid on the breaking strength 
of briquettes 
Sharkey colloid and— 
Per cent 
of colloid 
Weight of 
briquette 
Average 
load per 
briquette 
Load per 
gram of 
briquette 
Load per 
gram of 
colloid 
Quartz flour___ _ 
50.0 
Grams 
21.4 
Kilograms 
1,645 
1,690 
Kilograms 
76.9 
Kilograms 
153.8 
Do____ 
25.0 
23.8 
71.0 
284.0 
Do__ 
10.0 
21.2 
590 
27.8 
278.3 
Do___ 
3.6 
19.9 
218 
10.9 
303.9 
Medium sand_ 
50.0 
21.3 
322 
15.1 
30.2 
Do_ 
40.0 
21.9 
281 
12.8 
32.1 
Do_ 
30.0 
21.5 
209 
9.7 
32.4 
Do__ 
20.0 
20.4 
100 
4.9 
24.5 
Do.____ 
10.0 
18.1 
43 
2.4 
23.8 
THE BINDING POWER OF DIFFERENT SOIL COLLOIDS 
There were a few soil colloids available in the laboratory in sufficient quantity 
to make a few briquettes. These colloids were in the air-dry condition while 
the Sharkey colloid used in the above experiments was in the moist condition. 
The results of these tests are shown in Table IX. The five different colloids 
studied show rather wide variations in binding power. The different soil col¬ 
loids show rather wide differences in adsorptive power, as well as in general 
character and appearance, so it was but reasonable to assume that there would 
be differences in binding power; however, the differences were not expected to 
be as great as these results indicate. Perhaps when these materials are avail¬ 
able in larger quantities and in the moist condition, a more adequate explana¬ 
tion of the differences in binding power may be given. 
Table IX .—Showing the effect of the kind of colloid on the breaking strength 
of briquettes 
(a) 25 PER CENT COLLOID (AIR-DRY) AND QUARTZ FLOUR 
Colloid from— 
Weight 
of 
briquette 
Average 
load per 
briquette 
Load per 
gram of 
briquette 
Load per 
gram of 
colloid 
Stockton clay adobe soil_______ 
Grams 
24.0 
21.9 
23.3 
Kilograms 
1,726 
1,015 
664 
Kilograms 
72.0 
46.4 
28.5 
Kilograms 
288.0 
185.5 
114.0 
Sharkey clay soil...___.. ... 
Cecil clay loam subsoil.._.. 
(6) 10 PER CENT COLLOID (AIR-DRY) AND FINE SAND 
Norfolk fine sandy loam soil.. ... 
. .J 18.8 
61.2 
3.3 
32.5 
Marshall silt loam soil...__. 
...! 19.0 
90.7 
4.8 
47.8 
Sharkey clay soil...... 
.... 18.9 
1 
108.8 
1 
5.8 
57.6 
