he superficial tension,
and it would be independent of the density.

Careful observations with special precautions to ensure the cleanliness
of the water have shown that over a considerable range, the departure
from Tate's law is not great. The results give material for the
determination of the function F in (1).

+----------------+------------+
| T/(9[sigma]a^2)| gM/Ta |
+----------------+------------+
| 2.58 | 4.13 |
| 1.16 | 3.97 |
| 0.708 | 3.80 |
| 0.441 | 3.73 |
| 0.277 | 3.78 |
| 0.220 | 3.90 |
| 0.169 | 4.06 |
+----------------+------------+

In the preceding table, applicable to thin-walled tubes, the first
column gives the values of T/g[sigma]a^2, and the second column those of
gM/Ta, all the quantities concerned being in C.G.S. measure, or other
consistent system. From this the weight of a drop of any liquid of which
the density and surface tension are known, can be calculated. For many
purposes it may suffice to treat F as a constant, say 3.8. The formula
for the weight of a drop is then simply

Mg = 3.8Ta, (2)

in which 3.8 replaces the 2[pi] of the faulty theory alluded to earlier
(see Rayleigh, _Phil. Mag._, Oct. 1899).]

_Phenomena arising from the Variation of the Surface-tension._--Pure
water has a higher surface-tension than that of any other substance
liquid at ordinary temperatures except mercury. Hence any other liquid
if mixed with water diminishes its surface-tension. For example, if a
drop of alcohol be placed on the surface of water, the surface-tension
will be diminished from 80, the value for pure water, to 25, the value
for pure alcohol. The surface of the liquid will therefore no longer be
in equilibrium, and a current will be formed at and near the surface
from the alcohol to the surrounding water, and this current will go on
as long as there is more alcohol at one part of the surface than at
another. If the vessel is deep, these currents will be balanced by
counter currents below them, but if the depth of the water is only two
or three millimetres, the surface-current will sweep away the whole of
the water, leaving a dry spot where the alcohol was dropped in. This
phenomenon was first described and explained by James Thomson, who also
explained a phenomenon, the converse of this, called the "tears of
strong wine."

If a wine-glass be h