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 

 have just described, I have 

 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 



Fig. 132. Photographic Record of Effect 



of Carbonic Acid Gas 



Arrow marks moment of application. 



