134 
MESSRS. J. N. LA41GLEY AND H. M. FLETCHER 
In this experiment the injection of normal salt solution into the blood veiy con¬ 
siderably increases the rate of secretion of saliva, and this increase does not lead to 
any corresponding increase in the secretion of salts. Comparing salivas VII. and 
YIII., we see that, although in VIII. the secretion of saliva is more than twice as fast 
as in VII., yet it contains a less percentage of salts. And all three samples of sahva 
obtained after injection of normal salt solution have a much less percentage of salts 
than corresponds to their rate of secretion; this is readily seen when these samples 
are compared with those similarly obtained, but before injection, as in the following 
Table :— 
Table X. 
Number 
of sample. 
Manner of producing secretion. 
Rate of 
secretion. 
Percentage 
of salts. 
VI. 
IX. 
II. 
X. 
VII. 
YIII. 
1 Stimulate cliorda f — before injecting NaCl ‘6 . 
J after pilocarpin given I — a/ier injecting NaCl'6 
1 . f — before iniectino’ NaCl '6 . 
j Pilocarpm • . • . | i^/ecting NaCl '6 . 
1 Pilocarpm . - • • | feting NaCl '6 . 
•110 about 
•700 about 
•3.55 
•327 
•086 
•206 
•2844 
•2092 
•4008 
•1528 
•1772 
•1344 
At the same time, when the three samples of saliva obtained after the injection of 
salt solution are compared together, instead of with those obtained earlier, it is found 
that the percentage of salts in them follows Heidenhain’s law. 
Here, as in Experiment 8, the rate of secretion of organic substance does not 
increase to the extent that it normally would, with the increased rate of secretion of 
water. 
Effect of Injecting into the Blood a 2 per cent. Solution of Na^COg. 
We have tried the effect of injecting a 2 per cent, solution of salt into the blood in 
one experiment only, but the result was quite decisive as regards one point: the 
injection considerably increctses the rate of secretioii obtained by a stimu¬ 
lation of given strength of the chorda tympani. The experiment was a con¬ 
tinuation of 5a [cf p. 123). Three samples of saliva were obtained, under normal 
conditions, by stimulating the chorda, the secondary coil being at 14 ; the rate of 
secretion varied from 1’4 to I'S c.c. in a minute. Then 250 c.c. of 2 per cent, 
solution of Na^COg were injected into the blood ; after this the chorda was again 
stimulated, the rate of secretion was 2'4 to 2'8 c.c. in a minute. Further injection of 
500 c.c. of a solution containing 1 per cent. KI and 1 per cent. NaCl still left the rate 
of secretion, on chorda stimulation, higher than normal. 
