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some material, that it cannot be proved by the capillary 
method, is of no importance whatever. To solve theoretical 
problems, however, it seems to me, to be fit only under 
very much reserve. Î again point here to the difference 
between the sensibility to acids with Stange and with 
Kusano. Of course we cannot say with certainty, that 
Kusano ïis really right with his explanation of the 
difference; however it is very probable that he is correct. 
But it is very useful to see what result this inaccuracy 
has had with Stange. Of course Stange did not come 
to the conclusion, that it was the hydrions, that worked 
attractively, but that it must be the anions of the acids 
Kusano proves that the contrary is true. 
Of course we arrive now at the question which ions 
act the greatest part in the various chemotactica. In this 
point there is a great deal of discordance I will not try 
to give a review of this. It seems to me, that the various 
authors are wrong in their opinions of the influence of 
the hydrions or the anions being thus predominant, that 
they are right to disregard the influence of the other ions. 
When perusing the various treatises one gets the impres- 
sion, that every ion has its stare, though it is not always 
clear for a limited number of cases. 
$ 3. À colloïid-chemical conception of the influence of 
electrolytes with chemotactical phenomena. 
The drawbacks we have thus far been discussing, are 
such, that the possibility is not excluded that we have 
got a wrong idea of the influence of the chemotactica by 
a defective method. The older investigations gave a wrong 
impression of the active concentrations. Moreover the number 
of active solutions seems to be very limited for each object. 
The result of all this is, that as yet, they have never 
