284 



cliloridi') the surface-energy n also increases. Substitution of hydrogen- 

 atoms by the negative oxygen-atom has in the same way a magni- 

 fying influence on the original values of ft. 



In the case of the alcohols (fig. 2) the values of ;,», and also those 

 of the tempei'aiure-coefficient of f«, increase regularly with the 

 increase of the aikyl-radical ; mater however has evidently a special place. 



In the case of Acetic and Monochloro-, and Trichloroacetic Acids, 



dn 



ft increases regularly with the content of halogen, while ^- in these 



at 



cases is quite analogous. Dich/oroacetic Acid however shows a much 



larger temperature-coefficient, as a consequence of which the values 



of ft below 126° C. appear to be i/reater, above 126° however to 



be smaller than in the case of monochloroacetic acid. It must be 



mentioned also as a remarkable fact that the f^-^cnrve for Formic 



Acid is entirely situated above that for Acetic Acid, while at the 



dfi 

 same time the value of -— for the formic acid appears to be 

 ot 



uniisiuilly small. The special and diverging character of the formic 

 acid shows itself in a most striking way in this fact too. 



Diethylmalonate and Diinethylsuccinate (fig. 5) show within a 

 rather consideral)le temperature-range, almost the same values of ft; 

 furthermore a comparison of the ft-^curves of dimethylsiiccinate 

 and dimethyltartraie clearly demonstrates the strongly magnifying 

 power of the substitution of two hydrogen-atoms by the typically 

 negative hydroxyl-groups. This increase of the molecular surface- 

 energy by the substitution of negative elements of radicals into the 

 original molecules, according to these data and those formerly published 

 seems to be a quite general phenomenon. 



dft 

 ^ I r"-;pei't to the temperature-coefficients — themselves, it may 



ot 



be ici.irkcd iliai in the case of the halogen-derivatives of the 



li_\diu-carl)ons ihey seem to be not unappreciably variable with the 



temperaiuie in the case of ethgliodide and etlu/lidentchloride, and 



also in the case of f.pichlorohi/drine from (1,43 to 1,88 Erg.). In the 



case of the syinmetric'illg constituted compounds: ethylenechloride, 



and tt'tnichloro-, resp. tetrahromo- acetylene, they may be considered 



to be constant, while they furthermore appear to increase regularly 



with the augmenting content of the halogen: 



For CH^Cl.,: 2,16 Erg per degree. 

 For CM.Cl,: 2,36 Erg per degree. 

 For C,H,Br,: 2,51 Erg per degree. 



