34 ABSORPTION AND EXCRETION OF SALTS BY ROOTS. 
ture solutions below the equilibrium concentration and absorbed 
from solutions above this concentration, the results are very similar 
to those obtained with 
calcium alone (cf. ex- 
periment 2). 
10/7 
2 eos 
CONCENTRATION? CE SOLUTION BEFORE| GROWTH. 
N 
wy af a8 
~“ ss N N aq 
eb § % 
Ws lia tai 
— 15/7 
500,000 
EXPERIMENT 8. 
Solutions used in 
experiment 8 con- 
tained magnesium 
and calcium in the mo- 
lecular ratio 2, 1. ey, 
the ratio indicated in 
experiments 3 and 4 
as the most favorable 
for absorption. Con- 
centrations were de- 
termined after 6, 10, 
Fic. 20.—Curve showing relation of initial concentration of the cul- an d 13 days. Th e 
ture solutions to subsequent excretion and absorption of salts by pea 
9 temperature at the 
é beginning was 22.3°; 
on successive dates when concentrations were determined, 22.3°, 
WAL. POG Bin) = 
CHANGE [NM CONCENTKATION DUAING GROWTH. 
roots in solutions of Mg(NO3)2+Ca(N O3)2 in the molecular ratio 
TABLE VIII.—Statement of results, experiment 8. 
Number of culture sees see eee saee eee 1 2 3 4 5 6 Ff 
Concentration. 
iBelore erowthe: ee eee tee ee Distilled) _M_§|_2M_ |); 4M | 6M |_ 8M |, 10M 
water. | 500,000 } 500,000 | 500,000 | 500,000 | 500,000 | 500, 000 
Aiton OGaVS=cus! ae ee ee eS 10M 9M 9M 7M 5M 4M 2.5M 
500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500,000 
iNGter0) Gays ss2. eee ee ee 17M 22 M 17M 15 M 14M 14M 13 M 
500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500, 000 
Miter 13 days vse nes Bees 20 M 24M 20 M 19 M 16 M 19 M 19 M 
500,000 | 500,000 | 500,000 | 500,000 | 500,000 } 500,000 | 500, 000 
INumbernofeultine a. s-ssee eee ee | 8 9 10 11 12 13 14 
Concentration: 
Beloreerowthi.<.) 20.00) aa 4s ee 12M 14M 16M 18 M 20 M 22 M 24M 
500,000 | 500,000 | 500,000 | 500,000 | 500, 0U0 | 500,000 | 500,000 
INTLOTI GIG AY SO ene kes wey ek) ye 4M 2.5 M 2M _2M_ 15M _3M_ 3M 
500,000 | 500,000 | 500,000 | 500, 000 500, 000 000 } 500,000 | 500, 000 
Atior 10 davai hee ee 12M 12M 10 M 5.5 M 6M A5M | 4.5M 
500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500,000 | 500,000 
Miter 13. daystoust ee oe 19 M 18 M 18.5 M 14M 14.5M 11 M 9M 
500, 000 | 500,000 | 500,000 | 500,000 | 500,000 | 500, 000 | 500, 006 
231 
