WITHDRAWN FROM THE ACTION OF GRAVITY. 597 



figure of equilibrium, because, under these circumstances, the 

 superficial layer, from which the configuring actions emanate, 

 remains perfectly free ; whilst if these actions emanated from all 

 points of the mass, any unsymmetrical modification occurring in 

 the internal parts of the latter would necessarily produce one in 

 the external form. This is confirmed by experiment. The con- 

 dition of a solid system completely enveloped by the mass of 

 oil would be somewhat difficult to idealize ; but it must be re- 

 membered, that in the experiments relating to the precedino- 

 memoir, the system of the disc, by means of which the mass was 

 made to revolve, was very nearly in this condition, because it 

 did not reach the external surface of the mass excepting at the 

 two very small spaces which gave passage to its axis. But we 

 then saw (§ 9 of the preceding memoir), that when the mass was 

 at rest, its sphericity was only veiy slightly altered by the pre- 

 sence of this system. The theoretical condition may be more 

 nearly approached by taking a very fine metallic wire for the 

 axis of this same system ; in this case the alteration in form is 

 quite imperceptible. The axis being supposed to be vertical, 

 the disc may moreover be placed so that its centre coincides with 

 that of the mass of oil, or is situated above or below the latter 

 without producing any diff'erence. I shall relate another fact of 

 an analogous nature. In the course of the experiments, it some- 

 times happens that portions of the alcoholic liquid become im- 

 prisoned in the interior of the mass of oil, forming so many iso- 

 lated spheres. Now, however these spheres may be situated in 

 the interior of the mass, not the least alteration is produced in 

 the figure of the latter. 



11. Again, let us cause some kind of solid system to penetrate 

 the liquid mass ; but now let the mass be of too small a volume 

 to be capable of completely enveloping this system. The latter 

 will then necessarily reach the superficial layer ; and, if the prin- 

 ciple in question be true, the figure of the liquid mass will be 

 modified, or, in other words, will cease to remain spherical. 

 This does really occur, as we might have expected ; the liquid 

 mass becomes extended at those portions of the solid system 

 which project externally from its surface; it finally either occu- 

 pies the whole of these portions, or only a part of their extent, 

 according to the form and the dimensions of the solid system, 

 and thus assumes a new figure of equilibrium. We shall meet 

 with examples of this hereafter (§§ 14, 15, 17). 



