So 
Dr . Young's Essay 
to the pressure of a column appropriate to their distance 
Morveau found that two discs of glass, 3 inches French in 
diameter, at the distance of one-tenth of a line, appeared to 
cohere with a force of 4719 grains, which is equivalent to the 
pressure of a column 23 lines in height : hence the product of 
the height and the distance of the plates is 2.3 lines, instead of 
2.65, which was the result of Monge’s experiments on the 
actual ascent of water. The difference is much smaller than 
the difference of the various experiments on the ascent of 
fluids ; and it may easily have arisen from a want of perfect 
parallelism in the plates ; for there is no force tending to 
preserve this parallelism. The error, in the extreme case of 
the plates coming into contact at one point, may reduce the 
apparent cohesion to one half. 
The same theory is sufficient to explain the law of the force 
by which a drop is attracted towards the junction of two plates 
inclined to each other, and which is found to vary in the inverse 
ratio of the square of the distance ; whence it was inferred by 
Newton that the primitive force of cohesion varies in the 
simple inverse ratio of the distance, while other experiments 
lead us to suppose that cohesive forces in general vary in the 
direct ratio of the distance. But the difficulty is removed by 
considering the state of the marginal surface of the drop. If 
the plates were parallel, the capillary action would be equal 
on both sides of the drop : but when they are inclined, the 
curvature of the surface at the thinnest part requires a force 
proportionate to the appropriate height to counteract it ; and 
this force is greater than that which acts on the opposite side. 
But if the two plates are inclined to the horizon, the deficiency 
may be made up by the hydrostatic weight of the drop itself ; 
