A HISTORY OF 



From the fluid above pressing it down with 

 almost as great a force as the fluid beneath 

 presses it up. Take away, by any art, the 

 pressure of the fluid from above, and let only 

 the resistance of the fluid from below be suf- 

 fered to act, and after the body is gone down 

 very deep, the resistance will be insuperable. 

 To give an instance : A small hole opens in 

 the bottom of a ship at sea, forty feet we will 

 suppose below the surface of the water; 

 through this the water bursts up with great 

 violence ; I attempt to stop it with my hand, 

 but it pushes the hand violently away. Here 

 the hand is, in fact, a body attempting to sink 

 upon water, at a depth of forty feet, with the 

 pressure from above taken away. The wa- 

 ter, therefore, will overcome my strength; and 

 Avill continue to burst in till it has got to its 

 level : if I should then dive into the hold, and 

 clap my hand upon the opening, as before, 

 I should perceive no force acting against my 

 hand at all ; for the water above presses the 

 hand as much down against the hole, as the 

 water without presses it upward. For this 

 reason, also, when we dive to the bottom of 

 the water, we sustain a very great pressure 

 from above, it is true, but it is counteracted 

 by the pressure from below ; and the whole 

 acting uniformly on the surface of the body, 

 wraps us close round without injury. 



As I have deviated thus far, I will just men- 

 tion one or two properties more, which water, 

 and all such like fluids, is found to possess. 



" This phenomenon, which has so long embarrassed 

 philosophers, is easily soluble upon the principle, that the 

 attraction between the particles of glass and water is 

 greater than the attraction between the particles of water 

 themselves : for, if a glass tube be held parallel to the 

 horizon, and a drop of water be applied to the under side 

 of the tube, it will adhere to it : nor will it fall from the 



And, first, their ascending in vessels which 

 are emptied of air, as in our common pumps 

 for instance. The air, however, being the 

 agent in this case, we must previously ex- 

 amine its properties, before we undertake 

 the explanation. The other property to be 

 mentioned is, that of their ascending in small 

 capillary tubes. This is one of the most ex- 

 traordinary and inscrutable appearances in 

 nature. Glass tubes may be drawn, by means 

 of a lamp, as fine as a hair ; still preserving 

 their hollow within. If one of these be plant- 

 ed in a vessel of water, or spirit of wine, the 

 liquor will immediately be seen to ascend ; 

 and it will rise higher, in proportion as the 

 tube is smaller ; a foot, two feet, and more. 

 How does this come to pass ? Is the air the 

 cause? No: the liquor rises, although the 

 air be taken away. Is attraction the cause ? 

 No : for quicksilver does not ascend, which 

 it otherwise would. Many have been the 

 theories of experimental philosophers to ex- 

 plain this property. Such as are fond of 

 travelling in the regions of conjecture, may 

 consult Hawksbee, Morgan, Jurin, or Watson, 

 who have examined the subject with great 

 minuteness. Hitherto, however, nothing but 

 doubts, instead of knowledge, have been the 

 result of their inquiries. It will not, there- 

 fore, become us to enter into the minute- 

 ness of the inquiry, when we have so 

 many greater wonders to call our attention 

 away. 8 



glass, till its bulk and gravity are so far increased as to 

 overbalance the attraction of the glass. Hence it is easy 

 to conceive, how sensibly such a power must act on the 

 surface of a fluid not viscid, as water, contained within the 

 cavity of a small glass tube ; as also that the quantity of 

 the fluid raised, will be as the surface of the bore which it 

 fills, that is, as the diameter of the tube. 



