124 w - M - Ba y liss aüd J- E- Bradford, 



As has already been mentioned the electrical effect begins be- 

 fore the actual secretion and also reaches its maximum first; and 

 although on the whole the two processes run pari passu, neverthe- 

 less the electrical effect outlasts the secretion. On the other hand 

 an electrical effect may be produced without any obvious secre- 

 tion, e. g. by the employment of a stimulus which while too weak to 

 cause obvious secretion, as determined by the dropping of saliva from 

 the cannula, may yet produce a small electrical effect: the converse 

 however never occurs. 



The sign of the deflection obtained when the chorda is stimulated 

 by an excitation which is too weak to produce any obvious secretion, 

 is usually that of the main chorda phase, i. e. surface of the gland 

 becoming more negative, and it presents all the characteristics of this 

 phase, commencing quickly and rapidly reaching its maximum x ). 



Effects of chorda-stimulation on the current of rest. 



As has already been pointed out, from the nature of the experi- 

 ment a certain amount of injury is done to the gland and its surroun- 

 dings during the process of preparation, and since it is impossible to 

 eliminate this, it is difficult to interpret correctly the variations ob- 

 served in the current of rest. 



And, as was also before mentioned, it is frequently noticed at the 

 beginning of an experiment that the current of rest is very inconstant, 

 but that after the chorda has been stimulated a few times in suc- 

 cession the galvanometer-needle becomes quite steady. Another inter- 

 esting effect is also frequently observed, viz: — that after excitation 



*) Occasionally a different and remarkable effect is produced by these sub- 

 minimal stimuli. After a long latent period, a deflection small iu amount and slow in 

 its course is obtained, indicating that the outer surface of the gland has become 

 positive. Such an effect was recently obtained by one of us with the secondary coil 

 at the distance of 12.5 c, there being no accompanying secretion. On pushing the 

 secondary coil a couple of centimeters nearer the primary, the usual chorda variation 

 and a copious secretion were obtained. The deflection thus obtained with a submi- 

 nimal stimulus was very similar in its course to the one mentioned above as ob- 

 tainable after the action of atropine in small doses, resembling it in the length of 

 the latent period and in the slowness and smallness of the actual deflection : thus 

 giving the impression that they may be due to the same cause. 



