NOVUM ORGANUM. 175 



to carry the air contained in its interior down with it to 

 the bottom of the basin. We had first, however, placed a 

 small globe at the bottom of the basin, over which we 

 placed the bell. The result was, that if the globe were 

 small, compared with the interior of the bell, the air would 

 contract itself, and be compressed without being forced out, 

 but if it were too large for the air readily to yield to it, the 

 latter became impatient of the pressure, raised the bell 

 partly up, and ascended in bubbles. 



To prove also the extension (as well as the compression) 

 which air admits of, we adopted the following method. 

 We took a glass egg, with a small hole at one end ; we 

 drew out the air by violent suction at this hole, and then 

 closed the hole with the finger, immersed the egg in water, 

 and then removed the finger. The air being constrained by 

 the effort made in suction, and dilated beyond its natural 

 state, and therefore striving to recover and contract itself (so 

 that if the egg had not been immersed in water it would 

 have drawn in the air with a hissing sound), now drew in a 

 sufficient quantity of water to allow the air to recover its 

 former dimensions.* 



It is well ascertained that rare bodies (such as air) admit 

 of considerable contraction, as has been before observed ; 

 but tangible bodies (such as water) admit of it much less 

 readily, and to a less extent. We investigated the latter 

 point by the following experiment. 



We had a leaden globe made, capable of containing 

 about two pints, wine measure, and of tolerable thick 

 ness, so as to support considerable pressure. We poured 

 water into it through an aperture, which we afterwards 

 closed with melted lead, as soon as the globe was filled with 

 water, so that the whole became perfectly solid. We next 

 flattened the two opposite sides with a heavy hammer, 

 which necessarily caused the water to occupy a less space, 

 since the sphere is the solid of greatest content; and when 

 hammering failed from the resistance of the water, we made 

 use of a mill or press, till at last the water, refusing to sub 

 mit to a greater pressure, exuded like a fine dew through 

 the solid lead. We then computed the extent to which 

 the original space had been reduced, and concluded that 

 water admitted such a degree of compression when con 

 strained by great violence. 



* This passage shows that the pressure of the external atmosphere, which 

 forces the water into the egg, was not in Bacon s time understood. 



