380 HK. P. Dratrick 
in quadruple and was run for a period of two or four weeks. The nutrient 
solutions were made up from the following formulae: 
Salt lesCalciumagmibrate ewes ts soe onsen eee 27 += grams 
Salt 2: Maenesnimysulfa tes: sane). ns esr a cones 6 grams 
Salt 3. Potassium phosphate (monobasic)..... 15 grams 
SaltAweric culfatenmeete aaa ay ee orem ree 0.5 gram 
Salts; 2 Potassium: chlorides 2). )0. 4 ee 7.5 grams 
Salts 1 and 5 were dissolved together in 3 liters of water; salt 2 was 
dissolved in 13 liters, as was also salt 4, and both of these were mixed 
with salts 1 and 5. To the mixture was then added salt 3, after it had 
been dissolved in 3 liters of water. The total quantity was then increased 
to 10 liters by adding 1 liter of water. This solution contains 4656 parts 
per million of salts. 
The wheat seedlings were placed in cultures containing 10, 20, 100, 
200, 400, and 1000 parts per million of manganese in the form of manganese 
sulfate, and were harvested after remaining in the greenhouse for four 
weeks. The results are given in table 1: 
TABLE 1. Wueat SeEpLIncs (ENDOSPERMS NOT REMOVED) GROWN IN SOLUTIONS OF 
MANGANESE SULFATE. No Nutrients PRESENT 
Length Weight of four plants Total 
Parts per million (in centimeters) (in grams) ak Relative 
of manganese ac weight weights 
Leaves Roots Leaves Roots 
Olen ee es cee Se 18.2 .0784 .0514 . 1298 100 
LORS Nee ee en cies 10.6 10.3 .0940 .0460 . 1400 108 
QO WEG epee eee IS 5.6 .0967 .0319 . 1286 99 
OOM ete atregets: 10.6 4.2 .0658 .0211 .0869 67 
ZOO rears etseec 12.4 4.6 .0873 .0163 . 1036 80 
ADO) paterees 3 Serpents 10.9 Ba .0770 .0222 .0992 76 
ik OO e ae erase nace 9.8 Bats 0641 .0171 .0812 63 
As shown in table 1, solutions of manganese sulfate containing no nutri- 
ents were found to be toxic. All the manganese cultures, at the termina- 
tion of the experiment, might be characterized as dead or dying. There 
was no great increase in growth, if any increase at all, even in the lowest 
concentration. The total dry matter was reduced in all cases except 
with a concentration of ten parts per million. The first symptom of the 
toxicity of manganese is the yellowing of the tips of the lower leaves. 
