l 
| 
|| 
connected with its Surface Tension. 157 
in the equation LZ = E, (p,?—p.”), the value of #, is not constant 
as it should be*, but increases rapidly with the temperature, 
showing that mercury is in a polymerized state. 
_ A liquid may consist of molecules whose molecular weight is 
that indicated by the chemical formula, or of molecules poly- 
‘merized in equal degrees, or of a mixture of molecules polymerized 
in different degrees. The formulae discussed do not distinguish 
between the last two cases. It will therefore be of importance to 
develop one that does. 
In a previous papert it was shown that 
ee = eae (Ce Vvm,), 
Pinan pe 
when the density of the liquid is large in comparison with that 
of its surrounding vapour, where X denotes the surface tension. 
‘Since “ according to Traube is approximately proportional to 
“Wm, we may write 
| = 103 /m. 
Pe 
Hence the foregoing equation becomes 
= 3296 - — nd outa (9). 
1 
This equation holds independently of the extent of the polymeri- 
zation of a substance, provided all the molecules are polymerized 
to the same extent, in which case m and } Vm, have the same 
polymerization factor. Let us apply this equation to the four liquids 
mentioned in Table IV, which are known not to be polymerized. 
Tape IV. 
Name of liquid Xx 3296 ae) 
pit m 
Methyl formate ......... ee 32°6 
Carbon tetrachloride ... 3:99 3-25 
IBeENZeN er eet eee 46°5 45-66 
ITER omcca ls eee cds 62:92 66-11 
The table contains the values of the right- and left-hand sides of 
* Phil. Mag. Oct. 1910, p. 687. 
|+ Ibid. Jan. 1911, pp. 99—101. 
