The electrical phenomena accompanying secretion. \'.\\ 



Atropine, in the cat as in the dog, clearly shows that all the 

 variations observed are due to the glandular processes, as after com- 

 paratively small doses no electrical phenomena are observed on exci- 

 tation of the nerves. When the gland gives on chorda- stimulation a 

 pure first phase, this phase is very easily abolished by atropine, in 

 some cases as small a dose as 2 mgrms being sufficient. In the dog, 

 as we have seen, on chorda -excitation after the action of atropine in 

 small amount, a small second phase is observed which presumably 

 was not seen before owing to the magnitude of the first phase. 

 The second phase requires larger doses of atropine to abolish it 

 (e. g. 20 — 40 mgrms) so that if the gland is giving a diphasic variation 

 or a pure second phase, more atropine is required to abolish the ex- 

 citatory variation than if a pure first phase is alone present. Although 

 as a rnle this first phase is abolished by such doses as 2 — 10 mgrms, 

 yet occasionally a somewhat larger dose, e. g. 10 — 25 mgrms has to 

 be used, so that in those cases the first phase in the cat is rather 

 more refractory to atropine than the first phase in the dog. 



Thus although in the cat the activity of the chorda, as measured 

 by the secretion of saliva, is on the whole abolished by smaller doses 

 of atropine, than it is in the dog, yet, as measured by the electrical 

 phenomena, the chorda of the cat is more refractory to atropine than 

 the chorda of the dog; this being due to the fact, that the second 

 phase in the cat is much larger in amount. 



Sympathetic. — There is a marked difference in the electrical 

 phenomena produced by stimulation of the sympathetic in the dog and 

 cat respectively, as in the saliva secreted in the two cases. In the 

 dog excitation of the sympathetic only causes the secretion of two or 

 three drops of very viscid saliva (when, as in our experiments, the ex- 

 citation lasts but 10 — 20"), and there is a comparatively small and 

 slow electrical variation showing the outer surface of the gland to 

 become positive. In the cat a similar stimulation produces a copious 

 watery secretion, and a correspondingly large electrical effect. The 

 sympathetic electrical effect is always much greater than in the dog 

 and is frequently larger than the chorda- effect of the cat. Again it 

 is not nearly so constant in sign as in the dog, resembling in this 

 particular the chorda- effect in the cat, and showing very distinctly 



9* 



