516 



ANTAGONISM BETWEEN ALKALOIDS AND SALTS 



The results obtained with nicotine are shown in Fig. 1. The lower 

 curve shows that after 18| hours the resistance of the tissue has 

 dropped to 10 per cent (the death point) in 0.52 m NaCl, as well as 

 in 0.52 M NaCl to which sufficient nicotine has been added to make 



2 Has., 



18H Hrs. 



10'^ 



.o2 



04 



.06 A 



Fig. 1. Curves showing antagonism between NaCl and nicotine. Ordinates 

 represent net electrical resistance of Laminaria (expressed as per cent of the 

 normal); abscissae represent concentrations of nicotine added to 0.52 m NaCl. 

 The resistance of the control at IS-i- hours was 94 per cent. Average of two ex- 

 periments; probable error less than 3 per cent of the mean. 



the concentration 0.01 m. In NaCl 0.52 m plus nicotine 0.002 m the 

 resistance has dropped to 49.5 per cent {i.e., the tissue is about 

 half dead). It is evident that nicotine antagonizes the action of 



