634 



l)v tliyroidiii upon the action of adcenalin on the rise of blood pressure. 



We wished to know whether larger doses of lobelin had a stronger 

 potentiating effect than smaller ones. With a view to this several 

 injections of 0.1 mgr. of nicotin were administered, subsequent to 

 an atropin injection, to a number of decapitated cats, and then again 

 varying amounts of lobelin and finally again O.J mgr. of nicotin. 

 The results are given in Table 11. in which we have expressed the 

 rise of the blood pressure in m.m. Hg after the several injections. 



In Table III we have tabulated for different doses of lobelin the 

 difference in blood pressure afforded by 0.1 mgr. of nicotin before 

 and after the lobelin. 



TABLE 111. 



Mean values of the rise of blood pressure by 0.1 mgr. of nicotin 



before and after lobelin. 



Lastly the curve in Fig. 2 represents graphically the ratio between 

 the amount of lobelin and the change in the nicotin action, brought 

 about by those amounts, so this curve shows the relation between 

 the values in columns a and d of Table III. 



From the table and still more so from the curve it is evident 

 that the effect of the amount of lobelin is very considerable. In our 

 opinion the shape of the curve in Fig. 2 cannot be a basis for 

 further speculation, for which we need the mean values of a larger 

 number of experiments. 



Since the publication in 1909 of Bürüi's investigations other 

 researchers and himself have detected a number of combinations of 

 potentiating drugs. As expatiated upon by one of us in another 

 paper, only in a very few cases has the presence of such a "poten- 

 tiation" been proved. 



Since "potentiation" is doubtless one of the most remarkable 

 phenomena in modern pharmacology, we thought fit to communicate 

 this new. striking instance of true potentiation. Further research 



