1905.] Pharmacology of Indaconttine and Bikhaconttine. 479 
possible hitherto to institute a thorough comparison of the two series of 
aconitines under precisely similar conditions, but from the results of a few 
contrasted experiments, it seems likely that there is no large variation in the 
activity of the alkaloids under discussion from those previously examined 
towards muscular and intramuscular motor nervous tissue. 
BIKHACONITINE. 
Action of Bikhaconitine upon Blood-pressure and Respiration of Anesthetised 
Animals (Cats and Rabbits). 
The general features of aconitine are reproduced by bikhaconitine with 
regard to the circulatory system, but the latter develops a stronger action 
upon respiration, which is slowed and altered in character. Though not so 
active in this respect as pseudaconitine, it is more so than the other aconitines 
examined in these researches, and it is to this that the greater toxicity of 
bikhaconitine is attributable. 
In one experiment after the administration of three half lethal doses of 
bikhaconitine with intervals of 45’, a condition of “delirium cordis” was 
occasioned by strong vagus stimulation. Irregularity of the heart had 
already commenced and vagus stimulation (coil 10) had produced a rise of 
pressure with acceleration of the rhythm by 10 beats per minute, when after a 
pause of 15” the secondary coil was approximated to 8 cm., with the above 
result. The auricle remained in a state of contraction but exhibiting rapid 
twitchings, the blood-pressure rose for 3’’ and then fell rapidly, so that 5’ 
after the condition commenced the last of the irregular impulses had been 
recorded. The ventricles showed wild fluctuation apparently in every 
portion, which persisted for some time after all impulses had ceased in the 
carotid. No such result has been witnessed hitherto during the numerous 
experiments performed with the aconitines. Perhaps in this solitary instance 
it may have been due to the sudden exhaustion of the residue of co- 
ordinating action left in the vagus mechanism. The injection of atropine 
after the aconitines has never occasioned this phenomenon. 
When the effect of bikhaconitine upon anesthetised cats and rabbits is 
contrasted, it appears that the inhibitory action of the stimulated cardiac 
vagus is sooner abolished in the latter, but that at the time when this occurs 
section of the vagus still causes increased slowing of the respiration. 
Action of Bikhaconitine on Rabbits. 
A proportion of 0:00004 gramme per kilogramme (this is slightly less than 
one-half the lethal) causes acceleration followed by some degree of slowing of 
the respiration. Salivation rarely occurs. There is no paresis, but the 
VOL. LXXVI.—B. 2K 
