38 
Comparing the analyses in the last table with those in the preced- 
ing table it appears that the green plants of the last table contained 
as much lime and as little potash as the plants grown under condi- 
tions which induced chlorosis, but differed in containing much more 
iron. 
Analyses were also made of chlorotic plants and of plants that were 
once chlorotic but that had become green by treatment with ferrous 
sulphate. These plants were all grown in soil containing 33 per cent 
of calcium carbonate and, previous to the treatment with iron, were 
all equal in size and equally chlorotic. Two months after the plants 
treated with ferrous sulphate had become green all the plants were 
cut and analyzed. 
The results of the analyses are given in the table below. The first 
two analyses are to be compared with each other and the final three 
with each other, as the treatments with ferrous sulphate were carried 
out at different times in these two cases. 
Analyses of the ash of treated and untreated chlorotic plants. 








_ 
° Analysis of carbon-free ash. Ash ae eer on ap substance of 
of E 
Ag Ao es 231 5 eae se: pet fod f(b Ovsel Gaal" eel aes 
eee a8 Pp 1 |asleo i. Onlin | S| ees] HS S SH 
: oO o oF RS a o>} Ons a 
om ~ oO Ae) Ay ww Oo Sesh | LO Aa} wv ® a 
© 3 ~ |aeo|ae| Ee |e ea SESS ees ll ie & 
3 8 | o |wsl/Bo) 2] L/S) o |usiBo| ge) ys 
By @.|4j/2°|83| 5.) &le | SS (e381 see 
< 4 y ja 1h & | 4 jo HA |e [em a 
P.ct.|P.ct.|P.ct.| P.ct.|P.ct.|P. ct.| P.ct.| P. ct.|P. ct.| P. ct.|P. ct.|P. ct 
Unitreated- 2-2. | Chlorotic. . 255} 30.10) 9.18) 3.14! 37.69) 0.68) 5.87) 1.77) 0.54) 0.18) 2.21) 0.04)..... 
Brushed wit h 
HeSQy csc. 2. 2ee | Green..... 254 20. 59} 6.09) 4.04) 46.25) 1.51) 5.63) 1.16} .34) .23) 2.60) .09)..... 
Untreated. .......- Chlorotic. . 276| 22.01) 9.62) 2.67) 46.46) .44] 6.09) 1.34) .59) .16) 2.25) .03} 0.79 
Brushed with 
WESOR a= aes sex Green...-- 277| 24.52) 7.25) 2.46) 42.09) 1.49) 7.30) 1.79) .53) .18] 3.07) .11) .94 
FeSO, applied to 2 
FOOUS 6-6 (2-4-6 Bes MOS aac 278) 28.76) 9.25) 2.90) 37.02) 1.01] 6.89, 2.10} .68) .21) 2.55) .07| 1.39 












The ash of the plants turned green by ferrous sulphate differs from 
the ash of the chlorotic plants only in containing more iron. Thus 
it would seem from this table that the chlorosis is caused merely by 
a lack of iron or by a lack of iron in some active form, and that the 
generally lower content of potash in chlorotic plants is not the cause 
but a result. 
Considering all the facts brought out by the ash analyses, it would 
appear that. the chlorosis is induced by an increased absorption of 
lime and a diminished absorption of iron. It is certain that the 
absorption of an unusual amount of lime is not alone sufficient to 
cause the chlorosis. It is possible that when an excessive amount 
of lime is absorbed by the plant that more iron is needed than under 
ordinary conditions. The work of Hiltner on lupines substantiates 
this view.! p 



1 Loe, cit, 
[Bull. 11] 

