The Influence of Ammonia. 61 



THE INFLUENCE OP AMMONIA ON THE 

 MUSCULAR FIBRES OF THE HEART. 



It has been universally acknowledged by physiolo- 

 gists, that irritation of a nerve by ammonia vapour 

 does not cause the muscle which it supplies to contract ; 

 but abundance of evidence has come forward to show 

 that the application of ammonia to the muscle itself 

 gives rise to immediate contraction, more or less pro- 

 longed. 



The following experiment was recently made by 

 Mr. Price : 



A rabbit was injected with ^ grain of tiger-snake 

 poison into the external jugular vein. Death took 

 place within one minute. On opening the chest, the 

 heart and arterial vessels were found filled with clots. 

 The movements of the ventricles were insufficient to 

 get rid of their burden. The movements getting slower 

 and slower, the apex was cut off, and a drop or two of 

 a weak solution of carbonate of ammonia let fall into 

 the opened ventricles. Immediately increased contrac- 

 tions of the ventricles took place. 



This is in harmon}^ with what Dr. Sydney Ringer 

 has stated of the influence of ammonia on the muscles 

 themselves, rather than on the nerves ; arid, therefore, 

 this experiment agrees with what I have previously 

 said on the effects of the intra- venous injection of 

 ammonia. 



