389 
It is evident therefore, that also if this procedure is followed there 
is no trace of “potentiation”, the value obtained in the mixture- 
experiments not being higher, but lower than the sum of the actions 
of morphin and scopolamin separately. 
Hauvckorp and many others assume that small doses of scopolamin 
do not anaesthetize a rabbit. Our experiments go to show that 0.5 
mgr. of scopolamin has a distinct narcotic effect upon the magnitude 
of the reflex. In conjuction with Dr. G. Litsunstranp we ascertained 
the influence of various doses of scopolamin on a spinal reflex of 
the decerebrated rabbit. The result was that this narcotic effect does 
not increase continually with an increase of the dosis, but soon reaches 
an optimum and even decreases again after this (see fig. 2 firm line). 
It seems that with the higher doses a stimulating effect is added to 
the narcotic effect. 
It might be generally assumed that a twice larger dosis yields a twice stronger 
effect. This, however, is not the case with many of the alkaloids. When plotting 
the relation between the dosis per kg. of the animal and the effect of such a 
poison, the doses along the abscissae and the (narcotic) effect along the 
ordinates, a curve is produced, which first ascends abruptly, and then proceeds 
nearly horizontally. This is seen distinctly in fig. 2 (dotted line), borrowed 
from a paper by LrJESTRAND, v. D. MADE and Srorm VAN LEEUWEN U), in 
which the full line illustrates the narcotic effect of scopolamin in various doses 
(concentration-effect curve of scopolamin). 
Besides HauckKorp, Kocumann also studied this problem. He ex- 
perimented with dogs and believed that he had detected “potentiation”. 
Because we did not succeed in finding “potentiation” either with 
HauvckorLp’s method, nor with the one commonly used at our institute 
(influence on reflexes of decerebrated animals), we have also put to 
the test KocHMANN’s experiments. 
For this purpose series of from 3 to 6 dogs were given subcu- 
taneously morphin, or scopolamin or morph. + scop. The doses were 
calculated per kg. animal. 
An initial experiment was performed with the same dosis KocuMann 
had used. KocrmanN asserts that 5 mgr. of morphin and 0.5 mgr 
of scopolamin (we suppose his doses to be given per kg. animal, 
though the writer does not say so) do not of themselves produce 
any narcotic effect on the dog, but that their joint action puts the 
animal under a profound narcosis. It must be argued that this occurred 
only in few cases. Our initial results seemed to substantiate KocnMANN’s 
findings, for it appeared that in a dog 5 mgr of morphin + 0.5 mer 
1) LILJESTRAND, V. D. Mane and STORM VAN LEEUWEN. Zur Konzentrations- 
Wirkungskurve des Skopolamins. Appears in Pflügers Arch. 1919. 
