534 
The Philippine Journal of Science 
1920 
Birner and Lucanus (Shive) : S1 MgS0 4 , KH 2 P0 4 , Ca(N0 8 ) 2 . 
Crone: 32 CaS0 4 , MgS0 4 , Ca s (P0 4 ) 2 , KNO s . 
The study to be reported in the present paper was undertaken, 
as has been stated, to throw more light upon the problem as 
to what may be the physiological influence upon plants of con- 
siderable amounts of potassium chloride in a nutrient solution 
that also contains other salts supplying all the essential 
elements. 
This investigation was carried out at the Laboratory of Plant 
Physiology of the Johns Hopkins University, under the direction 
of Prof. B. E. Livingston, to whom I am indebted for valuable 
assistance during its progress and for aid in the preparation 
of this paper. I am also indebted to Dr. H. E. Pulling for many 
suggestions. 
GENERAL METHODS 
The experimental work comprised four series of cultures 
carried out at different times. The first two of these were 
planned to furnish a general survey of the relations between 
plant growth and salt porportions with a single total concen- 
tration of the solution (osmotic value 1.60 atmospheres). The 
results obtained from these two series made it appear desirable 
to test the effects of higher partial concentrations of potassium 
chloride than had been originally planned, and the third series 
included such tests. Finally, the influence of the total concen- 
tration of the medium was studied for four selected sets of 
Salt proportions; these tests made up the fourth series. The 
present section will begin with an account of the general methods 
employed in all four series. This will be followed by a more 
detailed account of the methods employed, the results obtained, 
and a discussion of these results for each of the series taken 
in order. 
In the nutrient solutions of the present study the essential 
elements (besides iron) were supplied as monopotassium phos- 
phate, calcium nitrate, and magnesium sulphate, and the chlor- 
ide ion was added by the introduction of potassium chloride. 
81 Birner, H., and Lucanus, B., Wasserculturversuche mit Hafer. (In 
der agr.-chem. Versuchsstation zu Regenwalde i. J. 1864 durchgefiihrt.) 
Landw. Versuchsst. 8 (1866) 128-177. Shive, J. W., A study of physio- 
logical balance in nutrient media, Physiol. Res. 1 (1915) 327-397. 
82 Crone, G., Ergebnisse von Untersuchungen liber die Wirkung der Phos- 
phorsaure auf die hohere Pflanzen und eine neue Nahrlosung. Sitzungs- 
ber. Niederrhein. Nat.- und Heilkunde. Bonn. (1902) 167-173. 
