June 1, 1925 
Effect of Seeds on Hydrogen-ion Concentration 
1023 
values upon standing when the tem¬ 
perature varies. Because variations 
in temperature cause apparent varia¬ 
tions in ion absorption the question 
might be raised whether or not this is 
due to the comparative dryness of 
the seeds at the time of immersion. 
If the seeds are dry, water intake 
would presumably be greater and 
occur at a faster rate than when wet 
seeds are used. To test this point 
corn seeds were soaked for a certain 
period in distilled water before sub¬ 
mersion into potassium sulphate. After 
the immersion a fresh potassium 
sulphate solution was used again to 
see when the limit of ion intake was 
reached. Table IV gives some of the 
data secured. It will be noticed that 
the changes produced by previously 
soaked seeds were very similar to the 
changes in the case of the air-dry seeds. 
The same seeds were then quickly 
taken out of the solution and again 
placed in a KC1 solution of 7 atmos¬ 
pheres osmotic pressure. The ob¬ 
served changes of reaction were not as 
rapid and extensive as was the case 
during the first immersion. After 
15 minutes the initial P H value of 5.9 
was changed to 5.0 and had risen 
again after 60 minutes to P H 5.3. 
Immersion of these seeds in the same 
and in fresh solutions for 15 hours 
caused no further changes. There 
seems to be no doubt that the equilib¬ 
rium was reached. Previous soaking in 
water seemed to have no influence as 
far as ion intake is concerned. 
Table IV.— Corn seeds soaked in dis¬ 
tilled water for 30 minutes before 
submersion into potassium sulphate 
Time 
Ki- 
SO< 
(7 
atm.) 
Fresh 
solu¬ 
tion 
Time 
Ks- 
SOi 
atm) 
Fresh 
solu¬ 
tion 
Minutes 
Initial_ 
After 5_ 
After 10- - 
After 15-_ 
Ph 
5.9 
5.1 
4.9 
4.3 
Ph 
5.9 
5.3 
5.1 
5.0 
Minutes 
After 2d— 
After 30. _ _ 
After 45_ 
After 60... 
Ph 
4.1 
4.3 
4.2 
4.2 
Ph 
5.2 
5.2 
5.2 
5.3 
After the reaction changes were 
observed, the first impulse was to hold 
responsible the rapid changes of life 
phenomena in the dormant seed when 
brought in contact with the solutions, 
or possibly the action of enzymes which 
are characteristic during the processes 
of germination. The possibility of 
changing the salt solutions and acids at 
such a rate bv these agents seemed 
remote; but, to make sure, seeds were 
killed by subjection to a temperature of 
100° to 102° C. for periods of 48 and 96 
hours. To prevent all possibility of 
enzyme action, beans were subjected to 
similar temperatures and then placed 
in formaldehyde. The data secured 
for seeds dried for 48 hours are given 
in Table V. 
