418 LIVING TORPEDOS IN BERLIN. 



living electrical fish is under these circumstances not so useful as 

 might be expected 1 . Dr. Hermes, however, was so good as to arrange 

 recently for supplying the Physiological Institute with Torpedos 

 through the Aquarium at Trieste, so that I might be able to make 

 such experiments on them as seemed desirable. It is scarcely neces- 

 sary to observe what an admirable prospect is thereby opened for the 

 advancement of the knowledge of electrical fishes, and consequently 

 of the physics of nerve and muscle. A single Torpedo at one's 

 disposal in a German physiological laboratory is possibly capable of 

 yielding more for the progress of our science than, to adopt Shylock's 

 mode of expression, the Adriatic full of Torpedos could do at a place 

 where you must first set up a galvanometer, and where, on account 

 of some piece of apparatus left at home or broken in the journey, 

 the most admirable plan of experiment becomes futile. 



In this way I have already worked out two Torpedos during last 

 summer, and three during the winter, and by means of them have 

 answered several questions which had been long present to my mind, 

 and I have also begun the observation of the secondary electromotive 

 actions of the electrical organ. Although these last researches are 

 not completed, I publish the results already obtained as, even in 

 their present condition they constitute an important supplement to 

 my previous communication on secondary electromotive phenomena 2 . 

 Moreover, the very small measure of completeness which I was 

 able to give to the researches on the same subject in muscles and 

 nerves did not appear to be attainable as regards the Torpedo for 

 reasons which I shall give later (p. 446). 



The animals employed belonged to the species Torpedo marmorata : 

 they varied in length from. 25-36 cm. The latter is the measure- 

 ment of a medium sized European Torpedo. 



2. General observations on experiments on Torpedos. 



The transport of living Torpedos from Trieste to Berlin is not pos- 

 sible in all weathers. Frost is no less injurious than summer heat. 

 Consequently the season for successful conveyance of the animals 

 is limited to the months of April, May, September, and October. 



The Physiological Institute in Berlin possesses its own fully- 

 equipped Aquarium. However, I thought it better to take advant- 

 age of Dr. Hermes' kind offer to keep the Torpedos in the tanks of 

 the Berlin Aquarium, which is only a few minutes distant. Here, 



1 Monatsberichte der Akademie, 1858, p. 94. 

 3 See No. VI. of this work. 



