IV
§ 12. 6) Adhesion. 44–58. The attraction between the
surfaces of two bodies.
Other applications: in raising a plank placed on water re
sistance is felt; walking through thick mud; gluing, soldering,
cementing, coating mirrors; dust on the ceiling etc. As a rule
cohesion and adhesion act against each other, in some cases
adhesion may change into cohesion: as in soldering, gluing,
cementing, luting etc.
§ 13. 7) Capillarity. 59-71. The attraction between
narrow tubes and liquids. It may be observed best in small
tubes (called capillaries, tubulus capillaris). If this adhesion
of the tubes preponderates, the liquid in the tube stands above
the liquid outside, and this is called capillaceous attraction; if
the cohesion of the liquid abounds, it will stand lower in the
tube than outside, and this we call capillaceous depression
(repulsion).
Other examples: The sap rising in plants; a lump of sugar
placed with only a part of it in water dissolves more quickly,
than is fully immersed, because in the first case the air, filling the
capillary tubes, is able to escape more rapidly than in the
second.
