387 
ascertained whether or no a narcosis ensued. We have repeated 
these experiments, but since — as also HAvckoLD observes — the 
depth of the narcosis is difficult to judge in rabbits, we altered 
the technique by administering on the same day the various poisons 
to a series of about twenty rabbits, almost simultaneously. Every 
quarter of an hour the condition of the animals was observed and 
noted down, the observer not knowing what poison had been injected 
into the animal under observation. 
In this way we made the following experiments: 
6 rabbits were given 10 mgr. of morphin per kg. subcutaneously. 
6 rabbits were given | mgr. of scopolamin per kg. subcutaneously. 
6 rabbits were given 5 mgr. morphin + 0,5 mgr. scopolamin per 
kg. subcutaneously. 
All the animals were examined regularly during 2°/,—3 hours. 
It thereby appeared that 1 mgr. of seopolamin had only a slight 
narcotic effect. The action of 10 mgr. of morphin was manifest; 
that of 0,5 mgr. of scopolamin + 5 mgr. of morphin was less 
marked than that of 10 mgr. of morphin alone; consequently 
“potentiation” was out of the question. 
After this negative result we examined the narcotic effect of 
scopolamin and morphin also by another method. A so-called isolated 
rectusfemoris preparation was made on decerebrated rabbits and the 
influence was recorded of morphin, of scopolamin, and of morphin 
+ scopolamin on the homolateral contraction-reflex of the rabbit. 
After a slight technical correction this method, which had already 
often been applied to cats *), appeared to be well-adapted for rabbits. 
The reflexes elicited in decerebrated rabbits by the faradic stimulus 
were registered on a Kymograph; and afterwards the results of 
every experiment were plotted. An instance of the influence of 5 
mgr. of morphin on the homolateral contraction-reflex of the rabbit 
is given in Fig. 1. 
In these experiments series of five rabbits were given 0,5 mgr. 
of scopolamin, or 10 mgr. of morphin or 0,5 mgr. of scopolamin 
+ 35 mgr. of morpbin and in all these cases the injections were 
not given till it appeared that the reflexes elicited by equi-intense 
stimulation were of the same magnitude. In case scopolamin + 
morphin was given, first the scopolamin was injected and 20 minutes 
later the morphin. 
The effect of the injections on the magnitude of the reflexes were 
1) W. Stokm VAN LEEUWEN, Quantitative pharmakologische Untersuchungen 
über die Reflexfunktionen des Rückenmarks bei Warmbliitern. I. Mitt Pflügers 
Arch. Bd. 154, page 307. 1913. IIL. Mitt. Pflügers Arch. Bd. 165, p. 84. 1916. 
