258 



DR JAMES A. GUNN ON 



Experiment 28 (tigs. 4 to 7 inclusive). — Strength of solution, 1 in 10,000. 



This solution very soon reduced the rate of beat of the ventricle, and to a less extent 



Fig. 4. 



the amplitude of its excursus (figs. 4, 5, and 6). In twenty-two minutes the ventricle 

 ceased contracting altogether, in a position of almost complete relaxation. Two minutes 



Fig. 5. 



Fig. 6. 



later the normal solution was turned on, and in five minutes this completely reinstated 

 the ventricle to its normal action (fig. 7). A second introduction of the harmaline 



Fig. 7. 



solution produced the same poisoning effects more quickly, and the ventricle again 

 completely recovered when this was replaced by the normal solution. The normal 

 solution was now perfused through the ventricle for over two hours. To the harmaline 

 solution was then added atropine sulphate in the proportion of 1 in 100,000. This 



