55 
Table XYI illustrates in a general way the reaction of the pupil 
to mechanical stimuli. Soon after being placed in the container the 
eye dilates to a maximum (10.48); then constricts to a minimum, in 
which condition it remains for a long time if all influences be kept 
constant. But by gently pipetting the eye about as is done (11.48 
a. m.) it dilates, sometimes slowly, but in this case rapidly, after 
which it again constricts. The experiment was continued (1.9) by 
replacing the Kinger solution with a very dilute solution of adrenalin 
of the same temperature, disturbing the eye to about the same ex- 
tent as before. This again caused dilation similar to that following 
the mechanical stimuli just described. At first sight this last dila- 
tion might easily be attributed to the adrenalin since the eye not 
only dilates more slowly but the dilation persists. Other observa- 
tions, however, lead me to conclude that the adrenalin has but 
little action and that which it has is exerted in supplementing the 
mechanical stimuli and perhaps in retarding the after constriction. 
Since ordinary sunlight is unsatisfactory for quantitative work of 
this nature, artificial light was substituted. If the proper intensity 
be used and the eyes observed at 22 to 23° C. then, instead of con- 
striction, dilation may occur with very dilute solutions. The dila- 
tion sometimes present with a concentration of 1 of adrenalin to 
625,000 of Ringer or with weaker solutions is, however, not at all 
suited for quantitative determinations. 
Table XVII. — Mydriatic action of natural l-adrenalin. 
EXCISED FROG’S EYE. 
Experiment 39a. 
1:2,000. 
Experiment 41a. 
1: 5,000. 
Experiment 55b. 
1: 25,000. 
Time. 
Long 
Short 
Time. 
Long 
Short 
Time. " 
Long 
Short 
axis. 
axis. 
axis. 
axis. 
axis. 
axis. 
A. m. 
M. m. 
M. m. 
P. m. 
M. m. 
M. m. 
P. m. 
if. m. 
M. m. 
10. 12 
a 2. 135 
a 1.700 
3. 56 
a 2. 010 
a 1. 430 
2. 10 
a 1.760 
a 1. 660 
10. 15 
a 2. 115 
a 1. 690 
4.5 
a 2. 055 
a 1. 650 
2. 32 
a 2. 030 
a 1. 840 
10. 20 
a 2. 070 
a 1. 720 
3. 25 
a 1. 765 
a 1. 435 
10.21 
a 2. 125 
a 1. 730 
3. 30 
a 1. 730 
a 1. 510 
10. 26 
a 2. 135 
a 1 740 
4.8 
a 2. 100 
a 1. 650 
3.42 
a 1. 790 
a 1. 595 
10. 27 
In adrenalin. 
4.9 
In adrenalin. 
3.44 
i In adrenalin. 
10.29 
6 2. 185 
b 1. 750 
4. 11 
b 2. 105 
b 1. 805 
3.46 
6 1.900 
6 1. 795 
2 
CO. 050 
cO. 010 
2 
CO. 005 
c 0. 155 
2 
CO. 110 
cO. 200 
10. 31 
b 2. 250 
b 1. 935 
4. 13 
b 2. 510 
b 2. 305 
3. 48 
6 1.990 
6 1. 940 
4 
CO. 115 
cO. 195 
4 
CO. 410 
c 0. 655 
4 
CO. 200 
cO. 345 
a Actual length of axis measured in 2 c. c. of Ringer solution at 23 ° C. 
6 Actual length of axis at time measured. 
c Change in length of axis after the eye is exposed to 2 c. c. of adrenalin solution for the number of minutes 
indicated to left in time column. 
