635 
was for the three groups respectively 0.0005 mgr., 0.001 mgr., and 
0.0014 mgr. This implies that when the intensity of the pilocarpin- 
action rises from a to c of the concentration-action-curve, three 
times as much atropin is wanted as before. The quantum of pilo- 
carpin required for a definite intensity of action, did not modify 
the quantum of atropin which would afterwards be necessary to 
arrest the pilocarpin action. 
Now that it had been demonstrated that in the zone a to c of the 
concentration-action-curve the atropin-action depends on the intensity 
of the pilocarpin-action, we suspected that with still higher pilocarpin- 
concentration, the atropin-dosis required for the antagonism, would 
not increase any more. 
If this were so our results would tally completely with those of 
VAN Lipra pe Jrupe, notwithstanding the difference between his 
criteria and ours. Contrary to our expectation, however, it appeared 
that with a further rise of the piloearpin-dosis, also the atropin- 
dosis had to be largely augmented, anyhow if we stuck to our 
criteria. So the latter result differs from that of van LiptuH Dr JRUDE, 
which finds a satisfactory explanation in the different techniques. 
In addition it is just with the high pilocarpin-concentrations that 
the difference between the criteria applied by van Liptn br JEUDE 
and by us comes much more to the front than in the previous 
experiment. For after these very high pilocarpin-concentrations the 
interval of 3 minutes, after which the atropin-action was observed, 
is too “short. In the experiments with small amounts of pilocarpin 
we observed that, if after 3 minutes the pilocarpin action was not 
yet arrested by the atropin, the atropin action increases but little 
with a longer interval, so that three minutes proved to be the proper 
time after which the action of the atropin should be registered. 
It is not so with the very high pilocarpin-concentrations, here 
it occurs repeatedly that after 3 minutes only a very insig- 
nificant effect has been produced by the atropin, whereas after 4 or 
5 minutes it is sometimes complete. Now, since with high pilocarpin- 
concentrations the space of 3 minutes is doubtlessly too short, and 
with low pilocarpin doses it must not be made much longer (or the 
chances are that the pilocarpin-action decreases spontaneously, so 
that an atropin-action could be presumed where it did not really 
exist) our method is not trustworthy in comparing the antagonistic 
atropin-action of small and very large pilocarpin-quanta. This is why 
we have not continued our inquiry in that direction and are only 
able to record that with a strong increase of the pilocarpin dosis in 
