Attraction. 19 



side by any small interposing body B., about the 

 thickness of a shilling, are immersed in water, 

 the water will rise between them in the curve 

 C. D. E., that is, highest on that side where the 

 plates touch each other, and at a moderate height 

 near the surface of the fluid. The same effect 

 was instanced in the water or liquor rising in the 

 piece of lump sugar ; and it may be seen every 

 day, when a piece of blotting-paper is used to 

 suck up a drop of superfluous ink. Another easy 

 experiment will further illustrate die nature of 

 this attraction. Suppose A. B. C. (fig. 3.) two 

 glass plates a little moistened with oil of oranges, 

 and placed upon each other, so as to touch at 

 the end A. B. Let them be kept open at the 

 other end by a small body C. If then a drop of 

 the same oil is introduced at the end which is 

 open, while the plates are kept in a horizontal 

 position, the drop will proceed with an accelerated 

 motion towards the end A. B. If the end A. B. 

 is then a little raised, the drop will be suspended 

 in its course, and, if raised to a considerable 

 height, it will return, but slowly ; in which case 

 the attraction of the plates is, in some degree, 

 overpowered by the weight or gravity of the drop. 

 This peculiar kind of attraction has received the 

 name of capillary attraction, from the experiment 

 having been made with small tubes as fine as a 

 horse-hair (capillus^ Latin), in which the water 

 will rise to a considerable height ; and upon the 

 same principle, water or any other fluid will rise 



