256 On certain peculiar Forms of Capillary Action. 
The near coincidence of the results of the second and third 
columns shows that, other things being the same, the height of the 
column CD, measuring the capillary resistance, varies inversely as 
the diameter of the orifice. 
The column of resistance, CD, is slightly affected by the thick- 
ness of the plate: thus with a half thickness of plate, and with 
an orifice of th of an inch, the height of this column was found 
to be 3 inches nearly. 
The number of perforations made in the plate does not affect 
the results. 
An increase of temperature sensibly reduces the height of the 
column CD: thus at the temperature of 84°, with an orifice of 
7th of an inch, this column was found to be about ;45th of an 
inch less than it was at the temperature of 56°. 
The column of capillary resistance, C D, for viscous liquids, 
such as diluted solutions of gum and sugar, was found to be 
considerably greater than the corresponding column for water. 
Let the tube EB (fig. 2), closed at the top by the perforated 
plate Ee, be depressed in the liquid, the orifice e beg wet; it 
will be found that the liquid will not rise in the tube to the same 
level as the liquid im the vessel: the column of depression C D, 
in this case measuring the capillary resistance under the same 
Fig. 2. Fig. 3; Fig. 4. 
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circumstances, is nearly equal to the elevation of the column C D 
of fig. 1. Here the resistance is simply due to the film of liquid 
filling the orifice e. It is scarcely necessary to state that, when 
the orifice e is dry, or nearly dry, the liquid will rise in the tube 
to the same level as the liquid in the vessel EB. 
In like manner, if the tube, partially filled with liquid, be 
raised as represented in fig. 3, it will be found that the liquid 
will stand in the tube some distance higher than the level of the 
liquid in the vessel. The column of elevation, C D, in this case 
measures the capillary resistance to the pressure of the external 
air. 
