TRANSACTIONS OF SECTION I. 667 
FRIDAY, AUGUST 2. 
The following Papers and Report were read :—- 
1. The Nervous Impulse. By Professor J. 8. Macponatp, B.A, 
The nervous impulse travels at a rate of 30 metres per second, that is to say, 
at about the rate of an express train. The chemical and physical changes charac- 
teristic of its passage were therefore difficult to examine. The fact, however, that 
two stationary conditions, namely, the condition of injury and the condition found 
at the kathode through which a polarising current was led out of the nerve, 
presented in all probability all the essential features of the same change, offered an 
indirect opportunity for the study of this process. In both of these conditions the 
same leading features could be identified, the colloid materials of the fibre were 
precipitated and a new material made its appearance, which in greater part at 
least could be identified by appropriate tests as potassium chloride, 
In view of these facts it was suggested that the nervous impulse was a physical 
process in which a change in the size of colloid particles led to the liberation and 
subsequent free movement of salt solutions condensed upon their surface, This 
free movement of new salt solutions was capable of effecting all the phenomena 
characteristic of the nervous impulse, 
2. Spinal Reflewes. By Professor C. 8. Suurrineton, 7.2.5. 
Records of spinal reflexes were shown illustrating the grading of intensity of 
the reflex movements in accordance with grading of intensity of the electrical 
stimulus used. This was demonstrated to be the case when the reflex contraction 
of a single muscle among those responding was taken for examination, as well as 
when the movement of the whole limb was used for recording. It was also the 
case when the stimulus used was a single break shock applied either to the skin or 
to an exposed afferent nerve. Examples of the staircase effect were also shown 
from the action of reflex centres. 
It was also reported that the change produced by strychnine in the inhibition 
part of the flexion reflex can be traced to occur through the early supervention of 
what is usually an after rebound of excitation. The change from inhibition to 
excitation produced by strychnine is easily temporarily reconverted back to 
inhibition by even a small dose of chloroform. 
3. Metabolism of Arum spadices : Enzyme Action and Electrical Response. 
By Miss H. B. Kemp and Miss C. B. SanDERs. 
In a paper tu the Botanical Section last summer we showed that the rise of 
temperature in the Arum spadices on the unfurling of the spathe is accompanied 
by a marked rise in CO, production and O, absorption, which follows very closely 
the temperature curve. 
The disappearance of starch in the tissue led us to some preliminary chemical 
tests which made it appear probable that there was a concurrent phase of extreme 
enzyme activity, and the putrefactive smell pointed to the presence of proteases. 
By the following tests (amongst others) one of us has ascertained the presence of 
these in A. maculatum, italicum, elongatum, crinitum, Sauromatum guitatum, and 
Dracunculus vulgaris. 
Extracted from the crushed spadix, twenty-four hours, and filtered (covered 
with toluol solution): The filtrate with 5 per cent. starch solution gives disappear- 
ance of starch in forty-eight hours, Boiled controls negative. 
The filtrate with } vol. Witte’s peptone solution in neutral HCl 0°025 per cent. ; 
