294 O H t? ie Adhesion of the Particles 



poured very limpid water to the height of nine inches, 

 and on the water I placed a stratum of ether, three lines 

 or twelfths of an inch in thickness. I then placed on 

 the surface of the water a number of small solid bodies, 

 which remained suspended, such as a small spherule of 

 mercury, some pieces of extremely fine silver wire, two 

 or three lines in length, and a little of the powder of 

 tin. When the whole was perfectly tranquil, I took 

 the glass in both hands, and carefully raising it, I turned 

 it three or four times round its axis with considerable 

 rapidity, keeping it in a vertical position. All the small 

 bodies suspended at the surface of the water turned 

 round along with the glass and stopped when it was 

 stopped ; but the liquid water below the surface did 

 not at first begin to turn along with the glass, and its 

 motion of rotation did not cease all at once upon stop- 

 ping that of the vessel. In fact, all the appearances 

 showed that there was a real pellicle at the surface of the 

 water, and that this pellicle was strongly attached to the 

 sides of the glass so as to move along with it. 



Upon examining with a good magnifier, through the 

 stratum of ether, the small bodies which were supported 

 at the surface of the water, the existence of this pellicle 

 could no longer be doubted ; more particularly when it 

 was touched with the point of a needle. For in this 

 case all the small bodies were observed to tremble at the 

 same time. 



Having left this small apparatus at repose in a quiet 

 chamber until the stratum of ether was entirely evap- 

 orated, I examined it again with a magnifier. The sur- 

 face of the water was precisely in the same state ; the 

 small solid bodies were still there, in the same situation, 

 and at the same distances from each other. 



