﻿258 



M. G. Quincke on the Capillary Phenomena 



Flat drops of Chloroform in Water. 

 ^ = 1-4878, (7 2 = 1, ^^=0-2439, 



No. 



2r. 



K. 



Jc. 



K-£. 



KV*. 



tt. 





milliras. 



millims. 



millims. 



millims. 



millims. 



mgrms. 



1. 



28-9 



4-891 



1-341 



3-550 



3-458 



3073 



2. 





4-614 



1-325 



3-289 



3-263 



2-638 



3. 



32-1 



5-170 



1-383 



3787 



3-656 



3497 



4. 



(36) 



4-935 



1-485 



3-450 



3-490 



2-902 



5. 



>> 



4-825 



1-353 



3-472 



3-411 



2-941 













Mean.... 



.. 3010 



It may be observed with regard to this and the following ex- 

 periments, that the liquids show the greatest cohesion at the 

 moment they come together; they then intermingle*; conse- 

 quently they become similar to one another in the neighbourhood 

 of the limiting layer; and by these means the tension a 12 of the 

 common surface must diminish, which would certainly be 

 as soon as liquids 1 and 2 were the same. This decrease is evi- 

 dent from the experiments. 



If bisulphide of carbon and water remain a long time ill 

 contact, an air- bubble is formed on the top of the drop of bi- 

 sulphide of carbon, which gradually increases in size. 



Analogous observations were made on drops of olive-oil, oil 

 of turpentine, and petroleum, the production of which was similar 

 to that of air-bubbles (compare § 5) under a horizontal glass 

 plate in water. The observed values of K, k, and K — k are ne- 

 gative ; for the sake of brevity, however, the negative signs are 

 omitted in the following collection of observations. 



* According to Dupre (Theorie Mecanique de la Chaleur, Paris 1869, 

 8vo, p. 373), the diffusion of two liquids will always take place as soon 

 as « 1 +# 2 <2F', where 2F'=«5 1 + <* 2 — «i 2 (loc. cit. p. 370). According to 

 these data, then, two liquids would diffuse as soon as #i 2 , the surface-ten- 

 sion of the common limiting surface, became negative ; but according to 

 my experience, not only do they diffuse for ef 12 = 0, but also when u l2 has 

 a very appreciable, of course positive, value. 



