ON THE SECRETION OP SALIVA. 
149 
Table XVII. 
Percentage of 
organic substance. 
Percentage of 
salts. 
Percentage of 
solids. 
I. 
•19 
1-34 
1-53 
II. 
•43 
•94 
1-37 
III. 
•34 
•94 
1-28 
, Since Werther’s are the only observations on the subject, we collected the saliva 
secreted by the left sub-lingual gland during the course of Experiment 12. In about 
if hour, 2‘6 c.c. of saliva were secreted. This was analysed, with the following 
result:— 
Table XVIII. 
Percentage of 
organic substance. 
Percentage of 
salts. 
Percentage of 
solids. 
•602 
1-034 
1-636 
The result confirms Werther’s observations as to the high percentage of salts; the 
percentage of organic substance is, however, somewhat higher than in his analyses. 
In the course of our experiment, 19 grin, of salts were injected into the blood; this, 
taken in conjunction with Werther’s observations, shows that the injection into the 
blood of a considerable amount of salts has very little effect upon the secretion of salts 
by the sub-hngual gland. 
The Rapidity of Secretion of certain Salts when Injected into the Blood. 
We have tried also two experiments on the rapidity with which substances injected 
into a vein appear in the,saliva. In these experiments pilocarpin was injected with 
the substances to be observed, and each successive three drops of saliva secreted 
collected separately and tested. We found that ; 
1. On injection of 50 c.c. of lithium citrate into the blood, the first drop secreted, 
both from the sub-maxillary and from the parotid gland, showed the lithium 
band in the spectroscope. 
2. On injection of 50 c.c. of potassium iodide into the blood, this salt was present 
in all the drops of saliva after the first six. The potassium iodide was first 
detected in the sub-maxillary saliva, as the secretion from this gland was more 
rapid than that from the parotid. The presence of potassium iodide was 
observed by adding to the saliva a little starch solution and then a drop or 
two of strong nitric acid. There may, of course, have been traces of potassium 
iodide in the first drops of saliva, which this test failed to show. 
