294 Mr. W. E. Dixon. The Pharmacological [Nov. 1, 
such as 20 milligrammes, injected into the circulation of the rabbit or cat, 
paralyse the sympathetic ganglion cells of the eye before the respiration has 
been appreciably affected. Thus, in one experiment on a small cat, it was 
found that well-marked dilatation of. the pupil and opening of the eyelid 
resulted from stimulation of the sympathetic nerve with the secondary coil 
at 12cm. A slow injection of 20 milligrammes of the alkaloid as a 0°5-per- 
cent. solution was made into the jugular vein and this caused paralysis, so 
that, a few minutes later, stimulation of the sympathetic, with the secondary 
coil at 5 cm., failed to elicit a response in the eye. Post-ganglionic stimula- 
tion, however, produced a typical effect with the coil at 12 cm. . 
(b) Splanchnic.—Boxwood paralyses the ganglion cells in the course of the 
splanchnic nerve, in the same way as it paralyses the cells in the course of 
the sympathetic nerve to the head. The injection of from 30 to 50 milli- 
grammes of boxwood alkaloid into the circulation of a cat blocks the 
conduction of impulses through the splanchnic nerve, so that its electrical 
excitation is without influence on the blood vessels. Stimulation of the post- 
ganglionic fibres still causes typical constriction of the splanchnic vessels, 
with a resulting rise in systemic blood-pressure (fig. 4). When still larger 
doses of the alkaloid are injected, a further stage is reached in which even 
excitation of post-ganglionic fibres is without effect. These facts may be 
interpreted as meaning that the ganglion cells are first poisoned, and later 
some portion of the peripheral nervous mechanism ; for it is certain that, even 
after the most complete paralysis, the muscle fibres of the vessels still respond 
to muscle poisons, such as lead, barium, veratrine, sauill, and the like. 
Effect on Motor Nerve-endings—Large doses of boxwood paralyse the 
motor nerves in a manner similar to curare; in the case of the cat 
80 milligrammes injected intravenously are generally sufficient to cause 
complete paralysis to electrical stimulation, and smaller amounts effect the 
same result in the rabbit. The frog is peculiarly resistant and relatively 
large doses are required to induce this paralysis; in this animal the central 
nervous system is paralysed easily enough, but the effect on the motor 
nerves is delayed. Strychnine in any dosage administered to animals in 
which the motor nerves have been paralysed has, of course, no effect on the 
muscles, nor can the spasmodic twitchings characteristic of physostigmine 
poisoning be obtained in such animals. The muscles, however, are intact and 
respond readily to all ordinary stimuli. 
Liffect of Certain Drugs. Nicotine—Evidence has been given already to 
show that boxwood acts upon the same structures as nicotine, so that were 
nicotine injected into an animal already under the influence of boxwood it 
should produce none of its characteristic stimulant effects. Injections of 
