OF THE ELECTRICAL ORGAN OF TORPEDO MARMORATA. 
497 
cut from it. This was effected by two vertical incisions through the organ in the 
direction of its columns, extending from the median to the external border of the 
organ. The cuts were parallel, and were 12 millims. apart. The block of tissue 
was separated from the gills which lie close to the median border of the organ. It 
was thus a slice of organ the dorsal and ventral surfaces of which remained covered 
by skin. This preparation was placed upon a glass plate, resting with one of its cut 
surfaces in contact with the glass; the dorsal and ventral skin surfaces were now led 
off by kaolin cushions, and the difference found to be + '0002 R. The slice was 
now reduced in thickness by cutting it into two thinner slices, the cut being parallel 
to the previous ones. One of these long slices, which resembled the previous one in 
all respects except that it was only G millims. in thickness, was now examined, and 
the difference found to be -f- ‘0007 It. This slice was still further reduced by another 
cut, and now measured only 3 millims. in thickness. The skin still remained covering 
the ends of the columns, and when led off a marked difference of potential was 
observed. This difference declined slowly; it was compensated at intervals of one 
minute. 
2 minutes after the cut difference 
— 
+ 
E. 
•0047 
3 „ 
55 
55 
55 
+ 
•0043 
4 „ 
55 
55 
55 
-= 
+ 
•0037 
5 „ 
55 
55 
55 
+ 
•0032 
6 „ 
55 
55 
55 
= 
+ 
•0030 
7 „ 
55 
55 
55 
= 
+ 
•0027 
8 „ 
55 
55 
55 
+ 
•0025 
15 „ 
55 
55 
55 
= 
+ 
•002 
It declined now very slowly, and another incision was therefore made. This was 
across the slice at right angles to the previous cuts. The experimental portion 
was therefore reduced to a small block of tissue, of the same thickness as before 
(3 millims.), but with a cut edge running parallel to its median border. The difference 
of the skin contacts was + '002 R. before the cut, and after the cut it was found to 
have largely increased. 
E. 
1 minute after the cut difference = + '0051 
2 minutes 
3 „ 
4 
6 
55 
55 
55 
55 
55 
55 
55 
5 5 
55 
55 
- + -0039 
= + -ocm 
= + -0028 
- + -0025 
= + -0023 
This block was now divided in the direction of the columns, a small prism of organ 
being thus made 12 mm. in length in the direction of the columns, 5 mm. in breadth, 
and 3 mm. thick. Three minutes after its preparation it was examined, and the 
difference of the ends of the columns found to be + '0039 R. 
3 s 
MDCCCLXXXVII.—B. 
