222 



The Characteristic of Nerve. 



at various gradients. To this end I found it convenient to first settle 

 upon a minimal sensation at a given mean voltage, and then to make 

 two further trials, one at half the voltage and four times the capacity, 

 the other at double the voltage and one-fourth the capacity. Each 

 group of three tests was thus at the same energy, but with the con- 

 stants of the three discharge curves in the proportion 1, 8, 64. The 

 minimal sensation having been settled with the constant at 8, it could 

 be inferred from equality or inequality of the effects at higher and 

 lower constants, whether the constant of a fitting stimulus lay above 

 or below either of the two extremes. 





F. 



V. 



FV. 



5FV 2 . 



C. 





Sensation. 



Forearm, 

 common 

 sensation. 



R = 45000 



-4000 



o-iooo 



-0250 



12 



24 

 48 



4-8 

 2-4 

 1 -2 



ergs. 

 288 

 288 

 288 



579 

 4632 

 34056 



-001250 

 -000313 

 -000078 



None. 

 Slight, 

 Marked. 



Tongue, 

 common 

 sensation. 

 R = 7500 



-0800 

 -0200 

 -0050 



12 



24 

 48 



0-96 

 0-48 

 0-24 



57 -6 

 57 -6 

 57 -6 



17380 

 139040 

 1112320 



-000416 

 -000104 

 -000028 



Marked. 



Slight. 



None. 



Optical 



sensation. 

 R = 21000 



-2400 

 -0600 

 -0150 



12 

 24 

 48 



2-88 

 1 -44 

 0*72 



172-8 

 172-8 

 172 -8 



2031 

 16248 

 129984 



-003493 

 -000873 

 0-000218 



Marked. 



Slight. 



None. 



Movement, 

 median nerve. 

 R = .30000 



'2000 

 -0500 

 0-0125 



12 



24 

 4S 



2-4 

 1-2 

 0-6 



144 

 144 

 144 



1706 

 13648 

 109184 



-004158 

 -001040 

 -000280 



(Movement) . 

 None. 

 Slight. 

 None. 



To verify the statement that at equal energy retinal stimulation pre- 

 dominates when the gradient is low, and common sensory stimulation 

 when the gradient is high, it is preferable to take stimuli above the 

 minimal and with larger difference of gradient, as e.g., in the following 

 experiment : — 



Anode on Eyeball. Kathode on Abdomen. E = 9000 ohms. 



F. 



V. 



FY. 



5FY 2 . 



C. 



h. " 



Sensation. 



mf. 

 0-04 

 0-36 

 3-24 



volts. 

 54 

 18 

 6 



mc. 

 2-16 

 6-48 

 19-44 



ergs. 

 583-2 

 583 -2 

 533 -2 



130200 

 4828 

 179 



sec. 

 -000250 

 -002245 

 -020200 



Stab only. 

 Stab + flash. 

 Flash only. 



