ON THE SECRETION OF SALIVA. 
117 
minute gives an increase in the percentage of salts of ‘026 per cent., i.e., the rate of 
increase is about ‘0037 per cent, of salts for ‘01 c.c. a minute of saliva. 
Here the first increase in the rate of secretion produces a greater proportional 
increase in the percentage of salts than does the subsequent additional increase in the 
rate of secretion. 
Taking similarly from Experiment 1 the three samples of saliva which were 
secreted with the least variation in rate during the collection of each sample, we 
have:— 
Table II. 
Rate of secretion 
per minute in c.c. 
Percentage of 
salts. 
Increase in percentage of salts corre¬ 
sponding to an increase of '01 c c. per 
minute in rate of secretion. 
V. 
•400 
•472 1 
•0035 
VI. 
•760 
•599 =1 
III. 
1-333 
•628 
-0005 
or inserting the calculated rates from I. and IV, :— 
Table III. 
Rate of secretion 
per minute in c.c. 
Percentage of 
salts. 
Increase in percentage of salts corre¬ 
sponding to an increase of 01 c.c. per 
minute in rate of secretion. 
V. 
•400 
•472 1 
•004 
I«. 
•500 
•512 = 
•0033 
VI. 
•760 
•599 ^ 
b. 
•900 
•616 . 
•0012 
III. 
1-333 
•628 . 
•0003 
We conclude then that the percentage of salts in saliva increases as long 
as the rate of secretion increases, but that the increment in the percentage 
of salts becomes less with each successive equal increment in the rate of 
secretion. 
We may now pass to consider the conditions under which the statement just made 
no longer holds. 
