1.04 
MR, G. J. BURCH ON THE TIME-RELATIONS OF THE 
Immediately after this experiment, without altering the electrometer circuit, the normal excursion, 
No. 289, was photographed for the determination of the constant multiplier used in this and the remain- 
ing illustrations. 
No. 270. Fig. 12, a, Plate 5.—Gastrocnemius. Exciting electrodes as far as possible from the muscle. 
No. 271. Fig. 12, b .—The same muscle. Exciting electrodes as close as possible to the muscle. 
No. 272. Fig. 12, c.—The same muscle. Exciting electrodes as close as possible to the muscle as in 
No. 271, but the leading-off electrode (to) shifted from its previous position to a point 12 millims. nearer 
the tendon electrode (/). 
These three curves were analyzed, and the results plotted together in fig. 12, Plate 5. 
It will be observed that the two former, though somewhat different in the first 
phase, are fairly alike in the second, the delay of the electrical response, in conse¬ 
quence of the greater length of nerve through which the excitation was transmitted 
in the case of No. 270, being well shown. 
It is interesting to note that the analysis of No. 272 approaches more nearly in 
shape to that of an “ artificial spike.” The rise of the electromotive force is fairly 
rapid, and it remains nearly constant for a considerable part of each phase. But 
neither the rise nor the fall is so sudden as in the case of Curve No. 306, although, 
as the difference of potential is less and the resistance of the circuit greater, any error 
due to overshooting of either kind is quite out of the question. 
No. 274. Fig. 13, a. —Gastrocnemius. Exciting electrodes placed on tbe nerve, close to its insertion 
in tbe muscle. Leading-off electrode (/) attached to the tendon ; electrode (to) on the side of the muscle, 
nearly at its thickest part. 
No. 276. Fig. 13, b .—The same muscle. Exciting electrodes as before. Leading-off electrode (m) 
shifted into the normal position on the belly of the muscle. 
No. 277. Fig. 13, c.—The same muscle. Exciting electrodes as before. Leading-off electrode (to) 
placed so close to the tendon electrode (/) as to give a scarcely visible excursion of the meniscus upon 
excitation. 
The analyses of these three curves were plotted together in fig. 1 3, Plate 6. 
They all cross the zero line within a remarkably small space. The first two differ 
slightly in the negative phase, but are tolerably similar in the positive, which is well 
developed. In both there is a second rise of the positive variation, reaching a 
maximum about 0 - 023 sec. after the excitation. This rise is, however, too small to be 
discernible from the photograph, and is made manifest only by the method of analysis. 
It does not come within my province to discuss the physiological questions arising 
out of these results, which I desire to leave entirely in the hands of Professor Burdon 
Sanderson, to whom I am deeply indebted for permission to make use of these photo¬ 
graphs, taken in the course of the research in which I had the honour of assisting 
him, in order to illustrate the method of analysis which I now bring forward. 
My sole object has been to show that the capillary electrometer can be employed to 
obtain measurements which hitherto could only be effected by a process open to some 
objections. 
The repeating rheotome, introduced by Professor Bernstein for the same purpose, 
