197 
culture. Generally the differences were insignificant. For 
KCI was once observed an important change of the sen- 
sibility. Here is discussed that the changed sensibility 
might be caused under the influence of a culture-fluid of 
a somewhat different composition. 
$ 3. There is discussed that the influence of base and 
salt according to the course of the curve for K,SO, in 
most alkaline solutions is about additive, while the influence 
of mixtures of acid and salt cannot be additive. 
Acid and salt counteract one another's influence. This 
also appears from the figure of sodium acetate in the 
most acid solutions. 
À similar conduct with regard to mixtures of salt and 
base and of salt and acid, was stated by Hardy with 
the dissolving of colloïdal globulins, which were flocculated 
by small quantities of electrolytes. 
$ 4. Here is discussed that the middle part of the 
curves often has a capricious out look, by the presence 
of maxima and minima. In general five maxima can be 
distinguished. Through this part of the curves an axis of 
symmetry can be drawn. This axis is often not horizontal. 
The possibility exists that the symmetry is caused, as we 
have to do with the action of ions. 
The principal direction of the middle part of the curves 
is influenced perhaps by the valence of the ions. 
The presence of the tops cannot immediately be explained. 
$ 5. Here is shown, that the plasmcolloïds can only 
be compared to colloïds, which can behave as acid and 
base but further contain properties of the suspenoïds. 
For a comparison the globulins ask for our attention. 
$ 6. By the figures is proved that the isoëlectric point 
(according to Michaëlis) of the plasmcolloïds can be 
expected in weakly alkaline solutions. The place of this 
point could not be fixed directly. 
