34 
BOTANICAL GAZETTE [JANUARY 
is a considerable reduction of stimulating effect caused by the presence 
of the quartz. Again the killing strength in solution is about n/ 100, 
Fic. 25.—Iron nitrate series in 
5 
Sept. 15-27. 1905. 
while in soil it is from 
6n/100 to 4n/100. 
In comparison with 
ZnSO, and AgNO, iron is 
a weak poison. And it Is 
interesting to note that 
solution. there is not nearly as great 
aa absorption of the 
poisonous elements in the Jatter as in the former. Fig. 22 shows 
EEE 
TH 
the Fe,(NO,). soil series after 
growing’ five days. It will be 
noticed that some elongation has 
taken place in the culture farthest 
to the left, which is #/1o. Further, 
3n/ 1000 : 
7n/ 1000 | | 
/ 1000 Ll, f 
gn, | its 
YS A 
ae Be 
n/ TSO 7 one 7 
ae WEES 
2n/ / Z fl 
f 100 ? 
VAY | 
seine LAr 
lA iv 
. ~~ 
4n/ too oe bi | 
mes 
52/100 : + 
Avi | 
fan / - oe 
O/ T00 + AT 
AA | 
; will, | é 
7#/ TOO - 
= 15 20 
—o 20 40 60 3 
oa eines ° 490 Boo 1200 300 ‘ 
pierce - 60 go 20 Seca | 35 65 9 ; 
G. 26.—Iron nitrate series in soil with nutritive _—Tron nitrate series in soil withow 
Fic. 
solution. Oct. 14-Nov. 8. 1905. 
Fis. 27 
tive solution. Oct. 29g—-Nov. 24- 1995- 
nutri 
