﻿of the common Surface of two Liquids. 



471 



On these grounds I do not consider very trustworthy the me- 

 thod used by many observers, of placing thin layers of different 

 liquids in contact with one another on glass, porcelain, or metal 

 plates, and observing which liquid forces the other away. In 

 many cases the tension of the free surface of the two liquids 

 placed together so considerably preponderates, that liquid 2 

 spreads itself out on liquid 3 and forces liquid 3 away from the 

 surface of the solid body 1, provided a 2 <a 3 . 



In this case, then, as the following summary shows, the order 

 of the liquids arranged according to the magnitudes of their ca- 

 pillary constants, agrees with the order in which the lower liquid 

 forces away a thin layer of the higher liquid from the surface of 

 a glass plate. Whether there is a perfect agreement between 

 the two series can only be judged from a simultaneous determi- 

 nation of the capillary constants of the liquids with which the 

 experiments on spreading were made. 



Brugnatelli * Carradori f. 



Olive oil. 







Petroleum . 



Spirits of wine. 

 Oil of turpentine. 

 Ether. 







Oil of turpentine. 

 Ether. 



Ben. Prevost%. 







Ludtge\. 



Sulphate of zinc. ^ 

 Common salt. 







Chloride of iron. 

 Sal-ammoniac. 



Saltpetre. 

 Glauber-salt. r 



a 

 o 



CO 



as 



a 



Water. 

 Blue vitriol. 



Blue vitriol. 





=J 



Ammonia. 



Sulphate of iron. 

 Alum. J 

 Water. 



O 



02 



Muriatic acid. 







Sulphuric acid. 

 Nitric acid. 



Fatty oils. 

 Etherial oils. 







Glycerine. 

 Potash. 



Alcohol. 

 Ether. 







Bisulphide of carbon. 



Poppy-oil. 



Acetic acid. 



Water. 







Plateau's soap- solution 



Fatty oils. 

 Soapy water. 







Oil of turpentine. 

 Benzine. 

 Alcohol. 

 Acetic ether. 

 Sulphuric ether. 



* Ann. de Chim. vol. li. p. 216 (1804). Gilb. Ann. vol. xxiv. p. 136 (1806). 

 t Ann. deChim. vol. li. p. 216 (1804). Gilb.^rm. vol. xxiv. p. 142(1806). 

 I Ann. de Chim. vol. xl. pp. 1 to 32 (1801). Gilb. Ann. vol. xxiv. p. 180 

 (1846). § Pogg. Ann. vol. cxxxvii. p. 369 (1869). 



212 



