518 



ANTAGONISM BETWEEN ALKALOIDS AND SALTS 



or less closely a monomolecular course. In the case of nicotine and 

 caffeine (where the experiment ran during the day and the following 

 night) this is not the case, except in the earlier part of the reaction. 

 This is perhaps explained by the fall of temperature which occurred 

 during the night and retarded the speed of the process. It should 



.Gin 



Fig. 3. Curves showing antagonism between NaCl and cevadine sulfate. 

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

 of the normal); abscissae represent concentrations of cevadine sulfate added to 

 0.52 M NaCl. ' The resistance of the control at 150 minutes was 100 per cent. 

 Average of two experiments; probable error less than 5 per cent of the mean. 



be noted that all the experiments in any set were begun at the same 

 time, so that all shared equally in the variations of temperature; in 

 consequence the form of the antagonism curve is not greatly affected 

 by such variations. 



In order to determine whether these alkaloids produce a decrease 

 in permeability they were added to sea water. The experiment was 



