224 
Journal of Agricultural Research 
Vol. XXIII, No. 3 
An examination of Table I shows that the only elements found in 
the Courtland greensand which were not present in the other two were 
chromium, nickel, and sulphur, and it might therefore be concluded that 
these were responsible for the toxic action. Such, however, does not 
appear to be the case, since an analysis of 1,000 gm. of the Courtland 
greensand showed only 0.63 gm. chromium oxid, 0.2504 gm. nickel oxid, 
and 1.6 gm. free sulphur. It must be stated, however, that with the 
large percentage of iron and aluminum present it was difficult to esti¬ 
mate the small quantity of chromium and nickel, and a close approxi¬ 
mation is all that is claimed for the figures here given. The part that free 
sulphur may play seems doubtful. Plants treated with a quantity of 
sulphur corresponding to that found in the toxic greensand, when mixed 
with the nontoxic greensands, failed to show any ill effects, yet it is 
possible that sulphur in intimate contact with some of the other elements 
concerned may be harmful. The Courtland greensand, however, was 
still toxic to plants after the free sulphur had been removed. 
The ferrous and ferric salt content differed but slightly in the three 
deposits, while the manganese content was much higher in the nontoxic 
Newcastle greensand than in the other two, and the calcium salt much 
less in the Courtland variety than in either of the others. 
EFFECT OF WATER-SOLUBLE SALTS OF GREENSAND ON GROWTH 
OF PLANTS 
To determine which compounds were water-soluble, and thus available 
to plants, portions of each variety of greensand were suspended in distilled 
water, constantly stirred for 12 hours by a. mechanical stirrer, and the 
solutions were filtered, concentrated, and analyzed. The results are 
given in Table II. 
Table II. — Analyses of washings of greensand from New Jersey and Virginia 
Constituents. 
Courtland. Va. 
Newcastle, Va. 
Red Bank, N. J. 
Si 0 2 . 
Per cent. 
60. 17 
Per cent. 
3 2 - 8 3 
Per cent. 
44.03 
2. IO 
2. 01 
5*40 
CaO.. 
I. 52 
l8. 42 
7. 70 
MgO. 
2.36 
I. 74 
I. 90 
Mn 2 0 3 . 
I. 18 
I. 02 
• 5 2 
p 2 o 5 . 
Trace. 
• 54 
•94 
N^O .. 
1. 05 
.49 
• 49 
k 2 o . 
2. 01 
1. 10 
1. 27 
Organic or volatile substances. 
9. 07 
13-91 
Plants grown in these washings were healthy and vigorous for three 
weeks, after which it was observed that those in the Courtland washings 
began to lag behind, and in another week they were dead. It will be 
observed (Table II) that the washings from the Courtland greensand 
showed a greater solubility of manganese than the washings from either 
of the others, although the manganese content as shown in Table I was 
greatest in the Newcastle greensand. Table II shows also that the cal¬ 
cium is much less in the washings from the Courtland greensand than 
from either of the others. 
From these data it was thought that the toxicity of the Courtland 
greensand might be due to manganese, iron, or aluminum in the absence 
of lime. 
