THE 
AMERICAN GEOLOGIST 
Vol. XXII.. NOVEMBER, 1898. No.. 5 
GEOLOGICAL PHENOMENA RESULTING FROM 
THE SURFACE TENSION OF WATER. 
By George E. Ladd, Rolla, Mo. 
(Plate VIII.) 
The term "surface tension" is the famiHar one used bv 
ph3'sicists to denote certain molecular conditions on the super- 
ficial film of bodies, where, owing to the absence of cohesive 
attraction on the outside, there exists a relatively greater sta- 
bility of position among its molecules, with reference to move- 
ment outwardly from the mass, and a tendency to dhninisli 
the extent of surface, — a resultant of cohesive forces acting 
alone from wdthin. 
This contractile tendency of the surface is manifested to us 
strikingly by liquids. In the case of water, among its effects 
are marked geologic changes, which are accomplished some- 
times directly, and sometimes through co-operation with other 
forces. They will be discussed or referred to here under the 
general headings: Effects produced by Capillarity; Floccula- 
tion; and Floating of Materials. 
Effects Produced by Capillarity. 
Among the most important results are those attained 
through the behavior of liquids in minute tubes or fissures: 
the phenomena being that liciuids, within such tubes, stand, 
under certain circumstances, in positions at variance with 
those occupied under normal conditions of gravity, or other 
influencing forces. 
These phenomena are onmipresent, and most important 
