150 On the apparent Repulsion 



doncd to themselves, thcv become conccutratecl. A drop 

 or two of spirit of wine, indeed, poured, in a gentle tem- 

 perature, on a j)orcelain dish for example, is seen to extend 

 itself, and to cover the said surface like varnish ; which is 

 not the case on pouring out a drop or two of water, beca\ise 

 it has not the same attraction of surface. The integrant 

 moleculas of the water, wliieh have more affinitv of aggre^ 

 jratiou or cohesion, than of attraction for the surface of the 

 supposed body, do not become flat, or dilate in the same 

 manner. 



It is so true, that spirit of wine or alcohol attaches itself 

 more strongly than water to the surface of vessels, that if 

 a drop or two of this fluid be thrown on a porcelain dishj 

 and if, after it has extended itself, forming as it were a 

 disk, some drops of water be thrown on it, and forced to 

 take the place occupied bv the spirit of wine ; it will be seen 

 that the water, not being able to detach the alcohol, will be 

 obliged to pass over it, and the alcohol will remain always 

 lixed at the surface of the dish. 



But I can produce an easy experiment, which is directly 

 opposite to the opinion of Draparnaud. I fixed, in the 

 middle of a porcelain saucer, a small ball of soft wax, and 

 formed in it a cavity with the head of a large pin. I then 

 poured into the saucer such a quantity of water as to rise 

 above the edges of the cavity, but not to enter it. The 

 vessel being thus prepared, I dipped a reed of straw in the 

 spirit of wine, and removed a drop of the fluid to the cavity 

 of the ball in such a nianner that it was filled with it. lu 

 this manner, a drop of spirit of wine remained surrounded 

 by water almost in contact with it, and continued also below 

 the level of the water, It is certain that, if spirit of wine 

 were capable of exercising an expansive force by means of 

 the particles it einanates, it n)ust have produced it in this 

 case; but I sav.' no movement of repulsion in the water 

 which was around the drop of alcohol. The water always 

 remained tranquil and motionless, a,?, if it had been close 

 to a fluid not of a volatile nature. 



Bui when the water had risen above the sides of the small 

 cavity of soft wax, it rushed into it to come to a level ; and 

 I saw the small bodies which flqated on the surface of the 

 water remove from the said cavitv, while the water rushed 

 into it. This is a proof that spirit of wine, like other oily 

 iluids, has the faculty of spreading itself over the surface of 

 the water before it becomes mixed with it. 



I have indeed observed, that spirit of wine applied to the 

 >\irfacc of water contained in a dish, on which is spread 



out 



