ii 4 RESPONSE IN THE LIVING AND NON-LIVING 



much earlier than that of B. The resultant curve R' 

 was obtained by summation. 



After taking the records of A and B separately, a 

 record of resultant effect R due to simultaneous vibra- 

 tion of A and B was next taken. It gave the curious 

 two -phased response positive effect followed by 

 negative after- vibration, practically similar to the re- 

 sultant curve R' (fig. 66, b). 



The positive portion of the curve is due to A effect 

 and the negative to B. If by any means, say by 

 either increasing the amplitude of vibration of A or 

 increasing its sensitiveness, the response of A is very 

 greatly enhanced, then the positive effect would be 

 predominant and the negative effect would become 

 inconspicuous. When the two constituent responses 

 are of the same order of magnitude, we shall have a 

 positive response followed by a negative after- vibration ; 

 the first twitch will belong to the one which responds 

 earlier. If the response of A is very much reduced, 

 then the positive effect will be reduced to a mere 

 twitch and the negative effect will become predominant. 



I give a series of records, fig. 67, in which these three 

 principal types are well exhibited, the two contacts 

 having been rendered unequally excitable by solutions 

 of the two reagents KBr and Na 2 C0 3 . A and B were 

 vibrated simultaneously and records taken, (a) First, 

 the relative response of B (downward) is increased by 

 increasing its amplitude of vibration. The amplitude 

 of vibration of A was throughout maintained constant. 

 The negative or downward response is now very con- 

 spicuous, there being only a mere preliminary indication 



