THE ANTAGONISTIC ACTION OF ^lAGNESIUM AND 



POTASSIUM 



w. j. v. o s i e r h o u t 

 (with three figures) 



It has been previously pointed out' that potassium may inhibit 

 more or less fuUy the poisonous effects of magnesium and that the 

 abundance of potassium in the soil makes this inhibitory action of 

 importance in soil investigations. LoEW and Aso» have criticized 

 this statement. Their objections are that only chlorids were used 

 and that no flowering plants were investigated. In the present paper 

 these objections are fully met. The experiments extend over a wide 



inns 



of the above-mentioned action of potassium. 



The technique employed has already been described in previous 

 papers in this journal.^ The material was placed in glass dishes con- 



taining: ioo~ 



I'dUlU-i^ l(JU~^UU KJX Lilt. JV/J.L4L^Vy^X ^^^ ^ * 



exclude dust and hinder evaporation. Water twice dbtilled and salts 

 which were tested for purity were used throughout. The results given 

 in the tables are in all cases averages of several series of experiments. 



The first experiments were made upon a marine alga, Enlero- 

 morpha Hopkirkii, ^vhich is able to live in both sea water and dis- 

 tiUed water. It was taken from the sea water, rinsed in distiHed 

 water, and placed directly in the solutions. The solutions used were 

 -f .u *^.t;„« ^ ^-r-m whiVh has the same osmotic pressure 



plants naturally grow. 



V lived but four da\-s ; in pure 



hile 



experiment 



continued. It is evident therefore that both KCl and MgCl, have a 



poisonous acti< 



«:i 



mix 



'■SS 



♦>:t 



1 OsTERHOUT, Lmveraty oi i^auiuru^ - """-» ' - 



. LOEW ASi^ Aso. BoH. Imp. Coll. Agr. Takyo 7:39S- ^W- 



sOsxERHorr. Box. G.«et« 42:1.7-34. x9°6; "^^^S^^T-JT^ 



[Botanical Gaaetw, ^m 

 II 7I 



