368 Dr. W. M. Bayliss. On Recoprocal [Jan. 20, 
in that the former was confined to the viscera; in all probability, the 
experiments on which this statement was based happened to be on subjects 
devoid of tone in the constrictors to the leg, as often occurs under experi- 
mental conditions. This erroneous conclusion serves as a warning against 
reliance on negative results. 
As far as conversion of excitation into inhibition is concerned, we see that 
the action of chloroform is the opposite to that of strychnine. Since these 
drugs are regarded as antagonists in general, some experimental results with 
respect to the action of chloroform on the vaso-motor system will throw 
some light on the question. 
Since in the normal depressor reflex excitation of dilators takes place, it 
would be expected that chloroform would reverse this effect; so that, in the 
“ dilator” animal, the depressor should cause a rise of pressure by inhibiting 
dilator tone. Up to the present I have been unable to obtain this result, the 
normal fall gradually disappears as the chloroform is slowly increased, without 
giving place to a rise. Whether this is due to the paralytic action of the 
drug on the centre, or whether the action of reversal is exerted on the 
constrictor centre alone, I am unable to state. The nearest approach toa 
positive result was a fall followed by a rise at a certain stage of chloroform 
action. 
The general antagonism of chloral and strychnine is shown in an interesting 
way in fig. 26. A small rabbit, under the influence of ether, gave curve A on 
excitation of the anterior crural nerve, the blood-pressure, which was at this 
Fie. 26.—Antagonism of chloral and strychnine. A. Effect of excitation of ant. crural 
on blood-pressure, under ether. B. Same after chloral. C. Effect of first 
dose of strychnine. D. Effect of second dose. E. Excitation of ant. crural. 
time 100 mm. Hg., rose to about 130 mm.; 0°7 gramme of chloral hydrate was 
then injected intravenously, the arterial pressure fell to 30 mm. and the 
reflexes were almost abolished (curve B). In curve C is seen the effect of 
13 milligrammes of strychnine sulphate. Although this was the first dose, a 
fall of pressure results; that is, the alkaloid acts like a sensory nerve under 
