498 
THE SALIVARY GLANDS. 
Parotid Gland- 
Saliva flow every 
30 sees, in mm. 
Nerve stimulated 
-Dog — Stimulation of the Sympathetic after Stimulation 
of Jacobso?i's Nerve. 
35 
J. 
14 
Sy. 
3 
Sy- 
o 
Sy. 
31 
J. 
(interval 11 1 
"i minutes )" 
32 
Sy.Sy. J. 
10 
Sy. 
A brief rapid increase in the flow of saliva is obtained by stimulating 
the sympathetic during the action of pilocarpine and other alkaloids 
which cause a continuous free flow of saliva. After the first rapid rise 
the secretion becomes slower, and in the parotid gland of the dog stops 
altogether: in the submaxillary gland the secretion slowly continues. 
Parotid Gland — Dog- 
Rise of saliva 6 6 
-Pilocarpine Injected. 
35 7 3 
stim. symp. 
Effect of Peotracted Stimulation on the Amount and 
Percentage Composition of Saliva. 
During protracted stimulation, as was shown by Becker and Ludwig, 1 
the percentage of solids in the saliva diminishes. They found a marked 
diminution in the percentage of organic substance ; and generally, but 
not always, some diminution in the percentage of salts. The most striking 
experiment given by them is the following. The chorda tympani was 
stimulated, and successive portions of the saliva were analysed : — 
Amount 
of Saliva 
Collected. 
Percentage of 
Organic 
Substance. 
Percentage 
of 
Salts. 
Percentage 
of 
Solids. 
1st portion .... 
2nd ,, .... 
3rd ,, .... 
4th , 
10-6 
13-2 
14-4 
13-9 
1-19 
1-26 
0-62 
0-27 
0-79 
0-63 
0-54 
0-48 
1-98 
1-89 
1-16 
0-75 
The decrease in the percentage of salts is probably connected, as 
Heidenhain has pointed out, with the slower rate of secretion of saliva 
in the later portions collected. 
Heidenhain 2 showed that the percentage of solids sinks during pro- 
tracted secretion, not only in chorda saliva, 3 but also in sympathetic 
submaxillary saliva. In the following experiment the sympathetic was 
stimulated at short intervals during five and a half hours ; the first and 
the last portions of saliva collected were analysed : — 
Time of 
Collection. 
Amount 
Collected. 
Percentage 1 
of Solids. 
First portion . 
Last ,, 
SO minutes 
88 
0-68 grm. 
0-89 „ 
3-73 
1-49 
1 Ztschr.f. rat. Med., 1851, N. F., Bd. i. S. 278. 
2 Stud. d. physiol. Inst, zu Breslau, Leipzig, 1868, S. 65. 
3 We have to refer so frequently to the saliva obtained from the submaxillary gland— 
(1) by stimulating the chorda tympani, (2) by stimulating the sympathetic, (3) by 
injecting pilocarpine — that we are driven to adopt the terms, chorda saliva, sympathetic 
saliva, and pilocarpine saliva, for the saliva obtained respectively in these circumstances. 
