168 Proceedings of Royal Society of Edinburgh. [sess. 
prevent the adrenalin rise, but also to cause a definite fall of 
pressure. This fall is not, however, very marked, as the vascular 
dilatation is being opposed |although not abolished by the adrenalin. 
(c) (d) 
Fig. 3. To show the neutralising action on the blood pressure of nitroglycerin 
and adrenalin. ( a ) Effect of adrenalin 0*0075 mg.; (5) effect of nitro- 
glycerin 0*6 mg. ; (c) effect of (a) and (b) combined ; (d) effect of adrenalin 
0*006 mg. with 0*6 mg. of nitroglycerin. 
The best antagonistic action is thus given with '5 c.c. of T5 per 
cent, solution of adrenalin combined with grain of nitro- 
glycerin — *0075 mg. of adrenalin is antagonised by *6 mg. of nitro- 
glycerin — that is, the nitroglycerin and adrenalin are as 80 to 1 . 
