1348 
while, according to the figure the order for the power of lowering 
the surface tension is the same. 
This result is, therefore, undoubtedly in barmony with the adsorp- 
tion theory. The only question still to be answered is why the added 
substances increase the limitation value. This however, was to be 
expected on account of the manner in which displacement takes place 
as shown from the research of FreunpiicH and Masius (le). What 
they found is as follows: Let substance A be adsorbed according to 
the equation : 
or expressed in logarithms 
x . L 
bog === log a + — loge 
m n 
(v the quantity adsorbed, m the amount of adsorbent, c the concen- 
tration of the liquid in equilibrium, @ and 7 constants). 
If now a substance B is added in definite concentration, the adsorp- 
tion of A takes place according to the equation : 
! 
Lv 
log = log a! + — loge 
m vi 
1 1 
The investigation always showed that — is smaller than —. As 
n n 
the dependency of log — on log c is represented by a straight line, 
u 
we readily perceive that the reduced coefficient causes a stronger 
displacement of A by B in the higher concentrations of A than in 
the lower ones. 
If now in the experiments described above the alcohol is added 
to the sol the concentration of the liquid in stability-promoting ions 
will be exceedingly small in comparison with the concentration of 
BaCl, when the limitation value is attained. If now we assume that 
the adsorption of each of these substances by itself is about the same, 
it will be readily perceived that the displacing influence will hinder 
the charge of the particle in a much lesser degree than the discharge. 
Hence an increase in the limitation value. 
Meanwhile it will be as well to dispense with further theories 
until the matter cited above has been extended by the investigation 
of more colloids and other organic substances as well as of other 
(particularly uni- and trivalent) coagulating ions. With this investiga- 
tion | have already made a start. 
The following fact has already been disclosed : aromatic substances 
