CHEMICAL REAGENTS ON AUTONOMOUS PULSATION 325 



other cases, again, an earlier re-introduction of fresh air into 

 the chamber is sufficient to restore the specimen to its 



FlG. 131. Photographic Record of Effect of Alcohol 



Pulsations to left show normal response, f Marks application of 5 per 

 cent, solution ; f ' application of 10 per cent. ; f" application of 15 per 

 cent. 



natural pulsatory activity. I give here (fig. 132) a photo- 

 graphic record of the effect of this gas on a vigorous speci- 

 men, in which its action 

 is seen to be somewhat 

 gradual. One curious phe- 

 nomenon which I have no- 

 ticed in connection with 

 the effect of this gas, is 

 that when it remains stag- 

 nant in the chamber its 

 depressing effect is much 

 more rapid than when a 

 current is allowed to stream 

 through. 



In the manner which I Fig. 132. Photographic Record of Effect 



of Carbonic Acid Gas 



have just described, I have Arrow marksmomento f application, 

 carried out further a number 



of experiments on the action of various gases and vapours, 

 such as ammonia, carbon disulphide, and others, all of which 



