LIVING TORPEDOS IN BERLIN. 44-7 



The first result of these experiments is that internal polarisation 

 of the organ follows the passing of a current through it in the 

 direction of the columns, which like the polarisation of muscles, 

 nerves and the organ of Malapterurus, is under different circum- 

 stances sometimes relatively positive, sometimes relatively negative, 

 the conditions required for the appearance of both polarisations 

 being generally the same in the latter as in the former. With a 

 long closing time, polarisation is in all circumstances relatively 

 negative ; with a short closing time, particularly of stronger 

 currents, relatively positive polarisation arises under certain condi- 

 tions. Under certain other conditions which cannot be intentionally 

 brought about, action in two directions results first negative then 

 positive, thus proving that here also negative polarisation is the 

 more transitory. As the functional activity diminishes positive 

 polarisation disappears, though it is a considerable time before it 

 is quite absent and negative polarisation alone remains. All these 

 effects are in general observed in equal strength to whatever part of 

 the columns the clay points are applied, provided that they are 

 kept at a constant distance. With a sufficient resistance of the 

 galvanometer - circuit, which is secured by the leading-off clay 

 points, these effects are the greater the greater the distance in 

 other words, we have to do with electromotive forces arranged in 

 pile. Finally, with an oblique direction of the polarising-current 

 along with an oblique position of the leading-off clay points, only 

 weak results in indefinite direction are met with. The proofs of 

 this are put together in the Appendix. 



The relations of polarisation to the direction of the polarising- 

 current are so marked in all these experiments, that one cannot go 

 into detail as to the phenomenon without first entering on this 

 point. My experiments had generally the same form as those on 

 the upper and lower half of the group of muscles, or on the anterior 

 and posterior roots of the spinal nerves 1 , that is to say the homo- 

 dromous and heterodromous currents are sent alternately through 

 the columns at definite intervals of time. The stronger the current 

 and the longer the closing time, the greater the interval must be 

 in order to give time to the preparation to return to a sufficiently 

 natural condition for comparative observations 2 . 



1 Sitzungsberichte, 1883, vol. i. pp. 363-383. 



2 Long continued series of experiments which have to be broken at definite 

 intervals are the more fatiguing from the necessity of constantly looking at the 

 clock to see whether the time for a fresh observation has arrived. After having 



