STIMl 7. . I TION OF THE S YMPA THETIC NER VE. 49 7 
sympathetic saliva may be obtained. It is convenient to have some 
name for this unusually rapid sympathetic secretion, and I have called 
it the augmented secretion? 
In the dog, the saliva of the augmented secretion is, in its physical 
characters and apparently in its percentage composition, intermediate 
between sympathetic saliva and that obtained by stimulating the 
cranial nerve. 
The augmented sympathetic saliva from the submaxillary gland of 
the dog is three to ten times as abundant as ordinary sympathetic 
saliva. In fifteen seconds about £ c.c. is usually secreted, but there 
may be as much at ', c.c. The amount of the augmented secretion from 
the parotid is one-third to one-half that of the submaxillary gland. 
The augmenting effect of stimulating the cranial nerve disappears 
in time, although the sympathetic is not stimulated in the interval. 
In the submaxillary gland of the dog the greater part of the effect dis- 
appears in ten to fifteen minutes. In the parotid, it has usually com- 
pletely disappeared in ten minutes. The rate of disappearance does not 
seem to be affected by the injection of atropine. 
Mere vascular dilation does not cause an augmented secretion, for 
if atropine lie given in sufficient quantity, to paralyse completely the 
cranial secretory nerves, stimulation of the cranial nerve, which still 
gives largely increased blood flow, does not increase to any considerable 
extent the sympathetic saliva obtained subsequently. 
When the sympathetic nerve is stimulated two or three times in 
succession for rather short periods, say of thirty seconds, the augmenting 
effect of a preceding cranial nerve stimidation does not necessarily cease 
with the first stimulation, but is visible, though to a much less degree, in 
the second, and it may be in later stimulations. In the case of the dog's 
parotid the third stimulation usually gives no secretion at all. 
The following extracts from the notes of experiments -will illustrate the 
statements made above with regard to the augmented secretion : — 
Submaxillary Gland — Dog — Stimulation of the Sympathetic after moderate 
Stimulation of the Chorda Tympani. 
Saliva secreted in mm. during 
successive 30 sees., 35A mm. 
= •25 c.c. . . . . H H 1 1 53i 20 1 20 4 2 1 
Nerve stimulated . . . Sy. Ch. Sy. 
In the second sympathetic stimulation the flow of saliva was 16 mm. 
during the first fifteen seconds, and 4 mm. during the second fifteen seconds. 
Submaxillary Gland — Dog — Stimulation of the Sympathetic after brief 
Stimulation of the Chorda Tympani. 
1 1£ J 
Sy. 
Longer stimulation of the chorda tympani has little effect upon the 
maximum rate of flow of the augmented secretion, hut it leads apparently to a 
less rapid fall after the maximum is attained. 
1 Joum. Physiol., Cambridge and London, 1889, vol. x. p. 291. 
VOL. I. — 32 
Saliva flow every 
30 sees, in mm. 
5 1 

15 
Nerve stimulated 
Ch. 
(for 2 to 3 sees.) 
Sy. 
