536 LIVING TORPEDOS IN BERLIN. 



The foremost duty enjoined seemed to be to establish more com- 

 pletely the dependence of absolutely positive polarisation upon the 

 current density, but at the close of the first communication, I still 

 needed systematic experiments on this subject. I have now made 

 such experiments in such a manner, that I sent a momentary 

 current of always the same duration through the same preparation, 

 but the current was produced by a Grove's battery with a number 

 of cells increasing- from. I. up to L. and decreasing again to I. 

 The following numbers give a picture of the results : 



I. 



4. Torp. Fresh. 00 + 0.0102. I'-P. 



CT o"-o764. 

 V. X. XX. XXX. L. XXX. XX. X. V. I. 



n 



500 + tf 



3-5. 20 



250 250 



38 || 87 



- 315 

 148 || 322 



125 41 10-3 



152 || 78 || 35 II 18 



XX. XXX. L. 



8. t +60 |S +43 || +173 

 \ I 78 



-P. I 78 II 173 II 319- 

 The preparation was very vigorous as the strong organ current 

 shows ; it shocks perceptibly the two first times, when excited by a 

 current of only one Grove, and shows from thenceforward absolutely 

 and relatively positive polarisation rising and falling regularly 

 with the current density. A disturbance occurred with thirty 

 cells, but it did not detract otherwise from the usefulness of the 



whole series. 



II. 



All as in Series I, except OC +0-0341. 

 I. V. X. XX. XXX. I. X. 



t +35+3J -"II IJ- 55- 3 



J- 5J- 

 1+19; + 



10 



3-5 i 2-5 || I I5-55I5 



-13 



+ 22 



- 13 



32 



I have given the second series, chiefly because it presents the 

 example of absolutely negative, relatively positive polarisation by 

 the heterodromous current ; this is the instance mentioned above on 

 p. 503, and though apparently incontestable, it is hitherto unique. 

 The occurrence of this polarisation is all the more significant, as 

 a relatively negative preliminary deflection precedes the relatively 

 positive principal deflection. Thence we may infer, that the relatively 

 positive heterodromous polarisation is always present, and is only 

 concealed by the homodromous, relatively negative polarisation. 



The first series shows in a very pronounced way, the phenomena 

 which were described in general language in the first communi- 

 cation. It appears to support the assumption of an absolutely and 



