74 
Journal of Agricultural Research 
Vol. XXXI, No. 1 
Table I .—Surface tension of miscellaneous substances in solution 
Material 
Water_ 
Sodium palmitate_ 
Do. 
Do____ 
Sodium stearate_ 
Do. 
Do.. 
Sodium oleate___ 
Do.. 
Do_ 
Potassium oleate. .... 
Do.... 
Do.—.. 
Soap, Castile.. 
Do-- 
Soap, Ivory. .. 
Do_ 
Do.... 
Soap, linseed oil (jell)... 
. Do-- 
Do. 
Mineral oil emulsion No. 1. 
Do.... 
Do__ 
Mineral oil emulsion No. 2. .. 
Do___ 
Do_ 
Casein (in saturated Ca (OH) 2 >... 
Doi... 
Do.... 
Casein (plus 1 per cent Ca (OH> 2 >. 
Do... 
Do___ 
Casein (plus 0.1 per cent Na- 
HC0 3 ). 
Do__ 
Do.... 
Milk, skim (on dry basis). 
Do. 
Gelatin (purified)... 
Do. 
Do..__ 
Glue (commercial)... 
Do... 
Do__ 
Saponin bark. 
Do...__ 
Do.... 
Con¬ 
centra¬ 
tion 
Per cent 
0.1 
.01 
.001 
.1 
.01 
.001 
.1 
.01 
.001 
.1 
.01 
.001 
.1 
.01 
.1 
.01 
.001 
.1 
.01 
.001 
4.0 
2.0 
.1 
4.0 
2.0 
.1 
1.0 
.1 
.01 
1.0 
.1 
.01 
1.0 
.1 
.01 
.1 
.01 
1.0 
.1 
.01 
1.0 
.1 
.01 
1.0 
.1 
.03 
Surface 
tension 
Dynes 
per cm. 
72.8 
31.2 
4ft 5 
50.7 
346 
39.4 
51.0 
24.0 
31.7 
49.0 
25.1 
32.0 
54.5 
23.2 
31.9 
25.6 
35.4 
48.3 
26.7 
37.8 
49.5 
26.9 
33.1 
50.6 
38.1 
42.3 
55.9 
51.4 
51.7 
53.8 
51.4 
52.0 
54.0 
43.0 
47.2 
49.8 
48.0 
50.1 
51.3 
56.5 
62.2 
46.0 
56.2 
64.8 
41.3 
41.6 
50.0 
Material 
Con¬ 
centra¬ 
tion 
Surface 
tension 
Tannin__ 
Per cent 
1.0 
Dynes 
per cm. 
48.4 
Do_ 
.1 
57.9 
Do...— 
.01 
71.5 
Gum arabic____ 
1.0 
72.0 
Do_ 
.1 
72.1 
Do__ 
.01 
72.1 
Glycerine. 
1.0 
71.5 
Do____ 
.1 
71.5 
Creosote (meta)__ 
1.0 
48.0 
Do. 
.1 
69.5 
Creosote (beechwood)_ 
.5 
43.6 
Do.. 
.05 
67.2 
Cresol...... 
1.0 
41.0 
Do... 
.1 
49.5 
Resorcin.. 
1.0 
55.9 
Do_ 
.1 
69.2 
Phloroglucine... 
1.0 
62.9 
Do... 
.1 
71.5 
Guaiacol___ 
1.0 
45.6 
Do...— 
.1 
70.0 
Pyrogallol.... 
1.0 
70.8 
Do... 
.1 
71.4 
Hydroquinine... 
1.0 
71.5 
Ofi of cloves (in 10 per cent al¬ 
cohol)... 
1.0 
39.4 
Do_ 
.1 
44.2 
Oil of Eucalyptus (in 10 per cent 
alcohol).. 
1.0 
32.0 
Do___ 
.1 
44.3 
Oil of cedar.. 
.1 
42.1 
Oil of cedar (in 10 per cent alcohol). 
.1 
42.1 
Oil of cottonseed... 
.1 
47.4 
Sodium oleate 0.01 per cent + 
casein (NaHCOa). 
.01 
30.4 
Sodium oleate+ 0.001 per cent 
casein. 
.001 
51.3 
Sodium oleate 0.01 per cent + 
casein___ 
.01 
.338 
Sodium oleate 0.001 + casein (Na- 
HCOs).. 
.001 
50.0 
Oil of cloves 0.1 per cent + sodium 
oleate.—- 
.01 
37.8 
Oil of cloves 0.1 per cent + gylcerin. 
.1 
44.3 
Oil of cottonseed 0.1 per cent + 
sodium oleate. 
.01 
38.7 
A comparison of the surface-tension values of the different sub¬ 
stances in solution with their spreading qualities/shows that there is 
no consistent relation between them. Those substances that 
spread well have a much lower-surface tension than water, but other 
solutions having even lower values do not show as good spreading 
qualities. For example, a 0.01 per cent solution of casein, albumin, 
or saponin spreads well on all of the surfaces tested. On the other 
hand, the soaps at 0.01 per cent concentration did not spread any 
better than water, although the surface tension was far below the 
values for casein, albumin, or saponin. It is evident from these 
results that there are other influencing factors besides surface ad¬ 
sorption that effect the spreading qualities of a solution. 
The other variable—namely, the tension at the interface of liquid- 
solid—is indeterminate. However, it was thought that by substitut¬ 
ing an oil for the solid, as suggested by Cooper and Nuttall, ( 1 ) and 
making surface and interfacial determinations, that some interesting 
data would be obtained. Accordingly, a mineral oil having a specific 
