76 
Walter Stiles 
Table XXXIII 
Absorption of Tons by Living Plants. (Data from Pantanelli) 
Duration 
Absorption 
Concentration 
of ex¬ 
in mg. 
ions 
in gm. mols. 
periment 
.A 
- % 
Species 
Salt 
per litre 
in hours 
Ration 
Anion 
Elodea 
Calcium chloride 
0-05 
2 
3-0 
0-41 
canadensis 
Potassium sulphate 
0-05 
2 
3-44 
0-29 
,, 
Ammonium sulphate 
0-05 
2 
0-29 
2-05 
Azolla 
Calcium chloride 
0-05 
2 
0-26 
o-oo 
caroliniana 
Potassium nitrate 
0-05 
2 
1-89 
0-91 
Aluminium nitrate 
0-0125 
2 
0-16 
0-23 
,, 
Potassium sulphate 
0-025' 
2 
2-67 
2-5 
,, 
Ammonium sulphate 
0-025 
2 
0-17 
2-28 
,, 
Magnesium sulphate 
0-025 
2 
3-58 
2-48 
,, 
Ferrous sulphate 
0-025 
2 
0-76 
o-6i 
,, 
Aluminium sulphate 
0-0125 
2 
o -95 
0-062 
Phaseolus 
Calcium chloride 
o-oi 
8 
1-18 
1-50 
multiflorus 
Barium chloride 
o-oi 
8 
0-04 
0-77 
Cicer 
Potassium chloride 
0-025 
8 
o -35 
0-23 
arietinum 
Calcium chloride 
0-025 
8 
0-025 
0-14 
yy 
Potassium nitrate 
0-025 
8 
2-74 
i -95 
y t 
Aluminium nitrate 
0-0125 
8 
o-68 
2-31 
Ulva lactuca 
Calcium chloride 
0-025* 
2 
3-29 
2-79 
„ 
Potassium sulphate 
0-025* 
2 
1-48 
0-18 
* io c.c. of 0-25 M salt +90 c.c. sea water. 
The unequal absorption of the ions of calcium chloride by Pisum 
sativum and Zea Mays was shown by Miss Redfern (1922 a), who 
examined the influence of the concentration of the salt on the degree 
of inequality of absorption by the former species. She found that 
the more dilute the solution the less the divergence between the 
absorption of the two ions. Her results for the edible pea are shown 
in tabular form below (Table XXXIV). 
Table XXXIV 
Influence of Concentration on the Absorption of the Ions of Calcium 
Chloride by the Roots of Living Plants of Pisum sativum. 
(Data from Redfern) 
Percentage absorption after 36 hours 
Initial concentration ( - N 
of solution Calcium Chloride 
o-i N 
o-oi N 
o-ooi N 
i7'74±I'376 
19-61 ±2-33 
23-10 ±5-30 
3 - 57 8 ±0-506 
12-47 ±i - 66 
I5-09 ±3-736 
It appears likely that the excess absorption of one ion is accom¬ 
panied in some cases by the solution developing an equivalent 
quantity of hydrogen or hydroxyl ions so that the solution becomes 
