Page:Proceedings of the Royal Society of London Vol 69.djvu/188

174 Experiment 3. Similar Experiment. Excitation of Right Sciatic at Intervals of only 1 minute. Rapid Exhaustion of the (ingoing) Response. No marked Alteration of Resistance. ? Increase "by Drying.

Time after

decapitation.

Mins.

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Voltage of response.

Resistance of pad

(corrected for R.

of electrodes).

100,000 ohms. 0-0050 0-0085 >0-0100

100,000 Galvanometer shunted, photograph begins.

100,000 ohms. 0-0100 0-0093 0-0080 0-0060 0-0040 0-0020 0-0005 trace

110,000

FIG. 3. (4220.)

Minutes.

B. DIRECT EXCITATION. A pad of the cat's foot, cut off 1 to 48 hours after death, and set up between unpolarisable electrodes as previously described (loc. cit., p. 481), generally manifests a small and gradually increasing ingoing normal current, not exceeding, as a rule, 0-0100 volt. With lapse of time this current gradually falls again. It is noteworthy that its direction (ingoing) is from the intact external surface towards the injured cut surface