116 Rev. J. B. Emmett on Capillaiy Attraction. 



power is astonishingly great *; indeed, since it increases when 

 the aperture is diminished, no limitot'its force can be assigned. 

 The laws which it obeys are imperfectly known : whilst mer- 

 cury is depressed by the immersion of glass, wood, and per- 

 haps all non-metallic bodies; it rises about a surface of gold, 

 silver, lead, tin, and most other metals, provided the surface 

 be clean; the thinnest film of oxide prevents the effect. If a 

 tube of glass be used, whilst water is elevated to a considera- 

 ble altitude, alcohol, which is lighter, is much less raised; 

 and mercury, the heaviest known liquid, is depressed. 



The following are some of the results obtained : — Tube 1st. 

 Water was elevated 4 inches, 5*75 tenths ; solution of sub- 

 carbonate of potash, nearly saturated, 4 inches, 4'5 tenths ; 

 muriatic acid (concentrated) 3, 3*5; solution of loaf-sugar 

 (1 sugar, 4 water) 3, 2-5; alcohol diluted with 10 parts of 

 water 3, 2; sherry 2, 4; spirit 25 percent under proof 1, 9'5; 

 alcohol 1, 9"5 f . Tube 2d. Water 4 tenths of an inch; nitric 

 acid 3 tenths; refined whale oil 1 "5 tenths; oil of lavender 

 1*5 tenths. So far as I can draw any conclusions from the 

 experiments which I have made, wlien glass is the solid made 



the tube: diviile this by planes perpendicular to its axis ; making the thick- 

 ness of each slice proportional to the distance of its nearest surface from 

 the vertex ; and a particle in the vertex will be equally attracted by each 

 slice. Hence if two tubes be taken, having different apertures, the glass in 

 each being proportional in thickness to its aperture, the water must be 

 equally elevated by each tube. Or form a sphere of glass, and at several 

 diameters place a drop of water : it will gravitate more to the sphere than 

 to the earth. Now since no such effect takes place, and since tubes of 

 equal apertures elevate equal columns, whatever be their thickness; and 

 since the most minute film of oil within the tube prevents its action ; the 

 force is that of the surface only, or of particles at a distance below it, which 

 is less than any measurable distance; and the particles are not endowed 

 with a centripetal force varying inversely as the cube of the distance. If 

 any other law of force, as 4th, 5th, &c. be assumed, its action may be in- 

 vestigated in a similar manner, by the same proposition ; which proves that 

 such a force cannot be purely corpuscular, as those commonly called cor- 

 puscular really are ; that its effects on capillary attraction will be such as 

 are here named ; and besides, that its effects on the aphelia of the jjlanetary 

 orbits must be very sensible. Since then none of the effects of a force 

 varying according to any power of the distance, but the square inversely ; 

 we conclude that matter possesses no power of attraction, but that deve- 

 loped by Newton. 



* The method of cutting large pieces of stone from the quarry, for oil- 

 mill-stones, which consist of a circle 7, 8 or 10 feet in diameter, and 

 1 1 thick; that of elevating immense weights by moistening a rope well 

 stretched, may be quoted as notable examples. 



f A capillary tube cannot be made to answer the [)urpcse of the hydro- 

 meter : for if a very minute quantity of alcohol be added to water, it is 

 depressed to nearly the level of spirit itself: and when spirit approaches 

 nearly to the strength of the Excise proof, a very considerable difference 

 in its strength produces little effect in the height of the column. 



use 



