EFFECT OF SEEDS UPON HYDROGEN-ION 
CONCENTRATION OF SOLUTIONS: 
W. RuUDOLFS 3 
In the course of a study on the effect of single salt solutions with 
definite osmotic concentration values upon absorption by seeds’, 
it was found that the H-ion concentrations of the solutions in which 
the seeds were immersed changed markedly during the process of 
imbibition. The general interest and importance of this phenom- 
enon in connection with seed studies made its further investigation 
highly desirable. Accordingly single salt solutions of magnesium 
sulphate, sodium nitrate, calcium nitrate, sodium chloride, potas- 
sium chloride, and potassium carbonate were prepared, ranging 
in osmotic concentration values from 0.001 of an atmosphere to 
7-0 atmospheres. The seeds used in connection with these solutions 
were corn, spring wheat, white lupine, watermelon, Canada field 
peas, Japanese buckwheat, dwarf Essex rape, and alfalfa. Fifty 
seeds of each of the larger kind and 100 each of alfalfa and rape were 
placed in small bottles each containing roo cc. of solution. The 
bottles were placed on a laboratory table, and the seeds were allowed 
to soak for a period of fifteen hours, after which the solutions were 
poured off and the H-ion concentrations determined by the colori- 
metric method, using the double tube standards of GILLESPIE’ and 
the apparatus devised by VAN ALSTINE.! 
The results of these determinations are given in tables I and II 
in terms of P, values. The initial P, values of the solutions are 
here compared with the final values determined at the end of 
* Paper no. 83 of the Journal Series, New Jersey Agricultural Experiment Station, 
Department of Plant Physiology. 
?Rupotrs, W., Effect of salt solutions having definite osmotic concentration 
values upon absorption by seeds. Soil Science 11: 277-293. 1921. 
’Grttespre, L. J., Colorimetric determination of od ata concentration 
age: buffer mixtures, with especial reference to soils. Soil nce 9: 115-136. 1920 
AN Atsting, E., The determination of hydrogen-ion concentration by the 
esas method and an apparatus for rapid and accurate work. Soil Science 
10: 467-478. 1920. 
215] [Botanical Gazette, vol. 74 
