135 



that make iiidnction-sliocks are more effective than break-shocks (Fig. 4). 



To get an impression of the 



p' """■■^^^MMiMMMiM^|N/^»^l conditions on which the magni- 



i • tnde of the discharge depends, 



I first investigated the question 

 wliether oi'gans which had been 

 kept in different liquids for 

 some hours, as a result showed 

 a change of the discharge-shock. 

 Of course, the nerves were 

 alwajs stimulated with maximal 

 stimuli. 



Fig. 4. Example of discharge after 



indirect nerve stimulation with make 



and break induction shock. 



In this way it appeared that an organ (without skin) kept in: 



Experiment 1. 



2,5 % NaCl-solution lost its irritability after three hours. The same thing was 

 true for sea water. In Fiihner's solution -|- urea ') the irritability strongly diminished 

 after three hours. 



Experiment 2. 



Organ 1: in (NaCI 2,5*^/0 -f KGl 0.1 o/^) no shock could be obtained after 40 min. 



Organ 2; in (NaCl 2,5 7o + GaCU 0,2 o/q). After 40 min. the shock had diminished 

 slightly. 



Organ 3 : in F. sol. after 40 min. shock not changed. 



Experiment 3 (see fig. 5). 



/v_ 



Pulintrtr^i iploting * 0, 



Fig. 5. 



A preparation made from Torpedo marmorata (size 15 cm.) from 3.50—4.10, 

 Organ 1 is put into NaCl 3 %. From 3.50 — 5.28 four records were made (fig. 8. 

 a, b, c, d), the preparation was then put into Fülmer's solution + Og. After about 

 60 min. record e, after another 38 min. record /", alter 20 min. record g. 



1) Fühner Zeitschr. f. allgem. Physiol. (1908) Bd. 85. 485. 

 Used solution was: 



NagCOs 0.2 



CaClg 0.2 



KCl 0.1 ) per 1 L. water. 



NaCl 20. 



Urea 25. 



