The electrical phenomena accompanying secretion. Ill 



above the point where the fibres of the chorda tympani leave it to 

 pass to the gland, and the peripheral end was also arranged for ex- 

 citation : sometimes it was left undivided as will be mentioned below. 

 A cannula was placed in "Wharton's duct. 



The outer surface of the gland was next exposed, an opening 

 made in its sheath of cervical fascia, and a non-polarizable electrode 

 placed in contact with this surface, which we shall henceforth call 

 the outer or cutaneous surface. A second electrode was then placed 

 in contact with the deep surface of the gland close to the hilus, care 

 being taken that it did not press upon the duct. In our earlier ex- 

 periments we placed the second electrode upon the duct itself, but 

 subsequently found that better results were obtained when it was 

 placed upon the gland as close as possible to the hilus. The current 

 of rest was compensated in the usual manner and the excitatory 

 changes were observed on a Thompson mirror-galvanometer. For sti- 

 mulation we used an ordinary Du Bois Reymond coil worked by two 

 Danieli cells and provided with Helmholtz's side wire. One of us ob- 

 served the deflections of the galvanometer, and the other superintended 

 the stimulation and recorded the rate of flow and the character of 

 the secretion. 



{To be continued in the next) 



