490 LIVING TORPEDOS IN BERLIN. 



The result could not be considered decisive, because the experiments 

 were made in the winter 1883-4 with the last fish and on the second 

 day, when the organ had no longer its full functional activity, and 

 for this very reason, they could not be repeated at that time. 



I resumed the thread of this investigation at the first opportunity, 

 when I received a fresh supply of Torpedos in the following summer. 

 The preparations employed in the following experiments were still 

 not all that could be desired, for they were taken from the first 

 fish which came to hand and which was in a state of opisthotonus 

 (see above, p. 479), and again, 24-27 hours had elapsed since 

 death ; they still gave however a strong organ current, an infallible 

 sign that their functional activity was maintained. 



In order to work under simpler conditions, I began by substituting 

 Helmholtz' arrangement of the inductorium for the usual one. I 

 did not however obtain closing and opening shocks which were as 

 congruent with each other as I desired, for if great exactitude is 

 required, this is not so easy in practice as in theory. For reasons 

 which may be deduced from my formulas 1 , the closing discharge 

 was now the shorter and stronger, while the opening discharge was 

 the longer and weaker. In accordance with this, the closing 

 discharge now played the same part as the opening one had done 

 before: if it was homodromous, then after tetanus of 5" there 

 ensued strong absolutely and relatively positive polarisation ; if it 

 was heterodromous, feeble absolutely positive, relatively negative 

 polarisation. The former action diminished very rapidly on 

 frequent change of direction. 



But now I replaced the inductorium by Saxton's machine, which 

 I have frequently mentioned and most recently in the treatise on 

 Secondary Electromotive Phenomena (see No. V) . This instrument 

 was constructed by Oertling for Dove, and I acquired it for the 

 physiological institute at the sale of his effects after his death 2 . 

 The turn-table was removed from the machine, and its axis was 

 connected by a pulley with the spindle of a water-motor, which 

 turned the armature seven times a second. The pachytrope 3 stood 



duration by means of the switch, employed on a former occasion (see No. V of this 

 work, par. x), was excluded here, as is self-evident, because the secondary coil would 

 have furnished a derivation to the galvanometer. 



1 Gesammelte Abhandlungen, etc., vol. i. p. 233 f. 



2 Sitzungsberichte, 1883, vol. i. p. 360. 



3 [The pachytrope is a contrivance, by which the coils of wire surrounding the two 

 legs of the armature can be connected in two ways, either so that the one is a con- 

 tinuation of the other and they are equivalent to one wire of double length, or BO 



