202 ADVANCEMENT OP LEARNING. [BOOK V, 



the point of suspension in the communication of the motion 

 of gravity ; that is, into the earlier or Jater perception ot its 

 inclination or depression : as in scales, where one side of the 

 beam is longer, though of the same weight with the other, 

 whether this inclines the beam ; or in siphons, where the 

 longer leg will draw the water, though the shorter, being 

 made wider, contains a greater weight of water. 



11. Inquire into the effects of intermixing or coupling a 

 light body and a heavy one, for lessening the gravity of 

 bodies ; as in the weight of creatures alive and dead. 



12. Inquire into the ascents and descents of the lighter 

 and heavier parts of one entire body : whence curious sepa 

 rations are often made, as in the separation of wine and 

 water, the rising of cream from milk, &c. 



13. Inquire what is the line and direction of the motion 

 of gravity, and how far it respects the earth s centre, that is, 

 the mass of the earth ; or the centre of its own body, that 

 is, the appetite of its parts. For these centres are properly 

 supposed in demonstrations, but are otherwise unserviceable 

 in nature. 



14. Inquire into the comparative motion of gravity, with 

 other motions, or to what motions it yields, and what it ex 

 ceeds. Thus in the motion they call violent, the motion of 

 gravity is withheld for a time ; and so when a large weight 

 of iron is raised by a little loadstone, the motion of gravity 

 gives way to the motion of sympathy. 



15. Inquire concerning the motion of the air, whether it 

 rises upwards, or be as it were neutral, which is not easy to 

 be discovered without some accurate experiments ; for the 

 rising up of air at the bottom of water, rather proceeds from 

 a resistance of the water, than the motion of the air, since 

 the same also happens in wood. But air mixed with air 

 makes no discovery ; for air in air may seem as light, as 

 water in water seems heavy : but in bubbles, which are air 

 surrounded with a thin pellicle of water, it stands still for a 

 time. 



16. Let the bounds of levity be inquired after; for though 

 men make the centre of the earth the centre of gravity, 

 they will perhaps hardly make the ultimate convexity of the 

 heavens the boundary of levity ; but rather, perhaps, as 

 heavy bodies seem to be carried so far, that tjiey rest, and 



