( 693 ) 
. 
was performed, the cannula being connected by means of a T-tube 
with a Marry tambour; a cannula was put in the jugular vein for 
injections and another was tied in the carotid artery to ascertain the 
blood-pressure by means of a mercury-monometer. The standard- 
solution contained 2 mg. per ce. After a sufficient normal-period 2 me. 
derrid were injected into the jugular vein; soon deep respirations 
manifested themselves, ending in paralysis when a much greater 
dosis (=4mg.) was administered. Smaller doses only resulted in 
intensified respiration, which lasted for a considerable time. 
In order to examine the changes of respiration more minutely, the 
delicate method of Drerser *) was applied. Here the animal breathes 
through a breathing-mask with minimum resistance and the expired 
air is received in an eudiometer and measured. The rate of the breath 
per minute, the volume per minute and per respiration, were calculated. 
After a sufficient normal-period derrid was injected, the needle of 
a syringe having been put into a vein of the ear beforehand. It now 
appeared that the rate first increased, then decreased rapidly; that 
the volume per minute first increased and then decreased but little, 
and that the volume per respiration increased rapidly. 
On further dosing respiration became irregular and feeble, and 
asphyxia followed soon after. So at first derrid strongly stimulates 
respiration; deepening of the respiration comes most to the fore, 
even so strongly that the quantity of air, inspired per minute, increases. 
This effect is already known of morphine and several of its derivatives 
and is a central one. When larger doses are administered the stimula- 
tion is followed by paralysis, resulting in death with warmblooded 
animals; if artificial respiration is applied it appears that this effect 
is a transient one and that the centre recovers itself after some time. 
Effect on circulation. 
During the above-mentioned experiment on the eel’s head the 
following could be observed from the heart: 
When after the normal-period derrid was added and the respiration 
was paralysed, irregularities showed themselves in the function of 
the heart, often resulting in long pauses; then slowing of the pulse 
was observed and dilatation, especially of the auricle. If the skull had 
been opened beforehand and the brain as well as the spinal cord 
destroyed, the same symptoms showed themselves, so that the cause 
must be put down to the circulation-apparatus itself. Therefore further 
1) Dreser. Pharmacol. Untersuch. üb. das Lobelin der Lobelia inflata. Scrmi1epe- 
BERG'S arch. 1890, n°. 26, S. 237, 
45 
Proceedings Royal Acad. Amsterdam. Vol. XIII. 
