1914] William N. Berg 189 



second liquid against air; in the third column, the surface tension be- 

 tween the two liquids as actually determined.^ 



Carbon disulfid-water 32.0 80.9 41.7 



Petroleum-water 31.7 80.9 37.6 



Chloroform-water 30.6 80.9 29.5 



Olive oil-water 36.8 80.9 20.5 



Turpentine-water 29.7 80.9 11.5 



Olive oil-alcohol 36.8 25.5 2.2 



Quincke concluded that the surface tension between tvv^o liquids 

 that do not react chemically, of course, is not quite equal to the 

 difference betv^een their surface tensions when measured separately 

 against air, and that it varies between this difference and zero, ac- 

 cording to the mutual solubility, etc., of the two liquids (p. 18). 

 This principle is important, because the surface tensions between 

 Solutions probably existing in muscle can be easily calculated, if the 

 surface tensions of these Solutions have been measured against air. 

 A direct measurement of the surface tension between contractu 

 Unit and adjacent lymph is, therefore, not absolutely necessary. 



Antonow^ measured the surface tension between water and a 

 second liquid, such as Chloroform, ether, etc., practically repeating 

 some of Ouincke's work, with the same result, i. e., the surface 

 tension between two liquids is equal to the difference between their 

 surface tensions when measured separately against air (p. 384). 



In certain cases, studied by Whatmough^ and by Antonow,^ the 

 mutual solubility of the two liquids may be great enough to bring 

 the surface tension down to zero or very near to it, while the two 

 liquids still differ greatly in their composition. Whatmough (p. 

 178) studied the surface tensions of several binary mixtures, such as 

 phenol and water, isobutyric acid and water, etc. In his experi- 

 ments, the two liquids were thoroly mixt, allowed to separate into 

 layers, and then portions of the upper and of the lower layers were 

 separately removed and their surface tensions against air deter- 



- An extremely interesting and detailed summary of data on surface ten- 

 sions of Solutions, etc., was also given by Castell-Evans : Physico-chemical Tables, 

 ii, pp. 708-801 (London, 1911). 



^Antonow: Journal de chimie physique, 1907, v, pp. 362-385. 



* Whatmough : Ztschr. f. physikal. Chem., 1901, xxxix, pp. 129-193. 



5 Antonow : Loc. cit. 



