636 
the zone c to d (and farther) of the CA-curve, the atropin-dosis is 
sure to increase still more, without our being able to procure ac- 
curate data on this head. 
CONCLUSIONS. 
I. In accordance with what has been found by v. Liptn pe JEUDE 
and others, the pilocarpin-action upon the surviving gut is entirely 
dependent on the concentration of the pilocarpin in the solution in 
which the gut is suspended. The pilocarpin-action is completely 
reversible. 
II. Contrary to van LiprH pe JRUDE’s assumption, also the anta- 
gonistie atropin-action depends entirely on the concentration and not 
on the absolute dosis of the poison present. 
The atropin-action is also completely reversible anyhow when the 
atropin dosage is not too large. A surviving piece of gut does not 
adsorb so much of the smallest active dosis of atropin present in 
the 75 c.c. of Tyrode solution, as to alter the atropin-concentration 
appreciably. 
III. With the relatively small quanta of pilocarpin (i.e. such as 
exert an action corresponding with the zône a—c of the C.-A-curve) 
the amount of atropin, required for the antagonism, does not depend 
on the quantum of pilocarpin administered, but chiefly on the actton 
exerted by that quantum. The quantity of atropin, necessary to 
arrest a sub-maximal pilocarpin-action is about three times larger 
than the quantity of atropin, required to exert antagonism on a 
pilocarpin dosis with only a slight action. With pilocarpin-doses 
with a maximal action, a strong rise of the doses is still accom- 
panied by a rise of the atropin-doses. The reason given above ren- 
dered it impossible for us to examine this phenomenon in detail. 
Utrecht. Pharmacological Institute of the University. 
