﻿388 M. G. Quincke on the Capillary Phenomena 



In fact the foregoing collection of experiments show a value 

 for Xrhcr which (with few exceptions, to which I shall presently 

 return) very nearly agrees with the value of the constant 2u de- 

 rived from the elevations in capillary tubes (§ 4), as results from 

 equation (16) when a ou is put equal to zero. 



In the series with olive-oil above and oil of turpentine below, 

 after breaking off the point of the capillary tube I observed no 

 movement for a long time ; then a movement occurred suddenly, 

 and the liquid certainly moved as quickly as if the oil of tur- 

 pentine alone had ascended. The oil of turpentine, for instance, 

 drove away the olive-oil from the glass side ; and as soon as it 

 had covered the meniscus of the olive-oil, it ascended, taking the 

 column of olive-oil along with it. By this it is proved that 

 ^rhcr in this case is found considerably less than 2a for olive- 

 oil, but, on the other hand, as nearly agrees with 2a for oil 

 of turpentine as might be expected generally in these expe- 

 riments. 



For "water above and alcohol below," only the mean of the 

 last two experiments is taken, as, in Nos. 1 and 2, at the small 

 height h the water diffused along the side of the tube had in- 

 creased the quantity of water contained in the alcohol and with 

 it 2a . 



For " water above and alcohol below," the upper meniscus of 

 the water in all the experiments is rendered impure by the rapid 

 diffusion or solution of the specifically lighter alcohol and its 

 ascent in the specifically heavy column of water, and possesses 

 then naturally a smaller capillary constant than 2a = 14*47 milli- 

 grammes for water. According to the varying rapidity with 

 which this contamination took place, the numbers of column 

 2)rAcr vary in magnitude ; the greatest is that in the last expe- 

 riment, in which a small air-bubble between the columns of water 

 and alcohol had retarded the diffusion of the alcohol in the 

 water. 



23. Results similar to those here described were obtained by 

 Bede** in the experiments which he made by a similar method, 

 and which here follow, with the notation which I have adopted 

 in this memoir. The capillary constants, as determined by him, 

 of the free surfaces of the liquids stand at the head of each 

 series of experiments. 



* Mem. Cour. Bruce, vol. xxx. p. 187 (1860). 



