July, 1889. 
REPORTS OF SOCIETIES. 
171 
Herbert Spencer, being a summary and conclusion of tbe same. He 
said that this work, tbe study of the second part of which the Section 
had just concluded, was a superstructure erected upon the one datum, 
the “ Persistence of Force,” which he understood to mean that no 
effect was conceivable without a cause, and conversely that no cause 
was conceivable without its effect. He then proceeded to trace the 
development of the various phases of Evolution as set forth in “ First 
Principles,” and showed how they followed from the primary 
assumption. The lecturer laid particular stress on the fact that 
people in general overlooked the process of Dissolution, which 
rhythmically alternates with the upward movement of Evolution, and 
that, when Being arrives at a state of complete equilibrium, owing to 
the continued redistribution of motion, Dissolution will then commence, 
and continue until it reaches perfection, when Evolution once more 
will take place. 
OXFORDSHIRE NATURAL HISTORY SOCIETY.—Tuesday, 
May 28th. The President in the chair. Mr. F. Gotch, M.A., gave a 
lecture on the “ Electric Organ in Fishes.” It was profusely illustrated 
with specimens, both dried and in spirits and also microscopical, by 
diagrams, and by lantern slides on the screen. The lecturer said that, 
like first-class and second-class men-of-war, there were first-class and 
second-class electric fishes. The three “ first rates ” known were the 
torpedo, a native of the Mediterranean, Bay of Biscay, Red Sea, and 
elsewhere; and two fresh water fishes, the electric eel of the Amazons 
and the electric barbel of the Nile. The common skate of our own 
shores was a “second rate” electric fish. He first gave a history of 
the torpedo and Nile electric barbel as known to the ancients. They 
were of opinion that the shock given by these creatures was a sudden 
frost or intense cold, sent forth at will. The electric barbel appeared 
in Egyptian hieroglyphics—unmistakeable from its very long barbels 
and antennae. The electric power of these fishes was first discovered 
by a French physician who lived in the Isle of Rhe. That the shock 
was indeed due to electricity was scouted as “impossible” by the 
English savants of the time, but the fact was soon conclusively proved 
by ingenious experiments. In the torpedo the electric battery 
consisted of four masses of short hexagonal columns, two at the head 
and two at the tail, the pair at the head being much the larger. In the 
eel about seven-eighths of the entire length of the fish were taken up by 
the battery, which lay on each side of the spine, only about one-eighth at 
the head being occupied by the digestive organs. These eels sometimes 
attained a length of seven feet or more. The barbel was quite a small 
fish, six to nine inches long, but very powerful, and a great deal of its 
body was taken up by its batteries. After briefly explaining the action 
of the electric current in the voltaic “ pile,” Mr. Gotch described the 
minute structure of the batteries of these fishes. They were made up 
of what were in fact “voltaic piles,” each column being one pile, con¬ 
sisting, as in the piles which we make, of plates with differing surfaces 
laid one on another. In the skate there were only sixty or seventy plates 
to the inch ; in the Nile barbel some 500. The electric power of the 
fish partly depended on the number of its plates to the inch, and partly 
on the number of successive shocks which it could give in a second ; 
the more plates and the more impulses, the greater the power. The 
plates were excited by the brain power of the fish; it only gave a 
shock “ when it was minded ” to do so. The shock given by the skate 
was very feeble--hardly perceptible to our senses—but a powerful 
torpedo, which would transmit from 105 to 130 impulsesper second, would 
give a man such a shock as to disable his arm or leg for the rest of the 
