228 BOTANICAL GAZETTE [SEPTEMBER 
in the ratio of 1:250, enabled the plants to resist still higher concentrations, 
as seen from the same table. 
TABLE A 
COMPARATIVE RESULTS AT THE END OF 30 DAYS 
SoImL NOT MANURED MANURE NOT STERILIZED 
TREATMENT 2 £ = 3 3 FE: b= ee 
Ss Z q gs 33 Sy a6 go 33 
s“|&°| 5" | 2° |e |e jo ie 
During yet POh ee ae 27 | 224 | 3.00] 0.41 | 16 | 220 | 3-5 0.48 
the entire roooPP™ Na,zHPO,| 9 152 | 3.05 | 0.45 | 6 60 | 3.8 | 0.50 
30 days ‘o00 “f ie 12 146 | 3.00 | 0.48 | 18 143 | 4-0 0.60 
#3000 ‘ es 10 122} 3.20 | 0,54-| 13 138 | 3-55 0.56 
During 4000 “ iy 1r | 135 | 3.10 | 0.42 | 17 | 143 | 3-5 0.38 
the last 5000 “ = 8 | 186 | 3.10] 0.42] § | 1801 3-5 oe 
7 days ese : 7 | 178 | 3.20] 0.41 | 4 | 187 | 3-8 | 05 
7000 “ . 26 | 190 | 2.90 | 0.38 | 15 | 195 | 3-7 mes 
Too0o “ “ 2s | 180 | 2.20 | 0.34 | 14 | 184 | 3-5 0.5 
b f the following set were watered with a 2000°P™ and the 
* Up to the last 7 days th 
odd ones with a roo0?P™ solution. 
That the increased tolerance of the wheat seedlings to the concentration 
of the salt is actually due, at least to a very great extent, to the absorpivt 
power of the soil is sustained by the following facts: 
(t) The analytical studies show that the soil actually removes large 
quantities of the phosphoric acid from the solution, as seen by the following 
table 
TABLE B 
ABSORPTION OF PHOSPHATE BY THE SOIL 
Sol MANURED 
: SoIL NOT MANURED pee 
P.M. OF P.O; eo ay 
gp pore awcogg METHOD Ppm. P.O, in |Per cent of P2O,| Ppm. P.Os in on jn D 
filtrate or in rhe — va ee 
absor 2 awe 
25-5 
TO90 A* 795 20.5 745 a 
— By 728 27.2 698 Se 
2000 rei 1740 26.0 it 32.6 
2000 16 1.0 1074 
T 90 3 a 
RS Oe eS eg occasional 
2 MeEtHop A.—25®™ of the soil mixed with 50°° of the corresponding sol ae 
shaking for 48 hours, filtered and the filtrate analyzed for phosphates. : only) and 2 
t Mernop B.—2oo% of the soil placed in a wire basket (paraffined along the sides O° hates 
fel 3. 14! rT a. p 1 “ss mes a4 the percolate analyzed 
; = oe igible 
(2) In the case of a nitrate salt, where the absorption 1S # mee 
quantity, the tolerance of the immersed and non-immersed plants, “ 
