Tue Errect oF MANGANESE COMPOUNDS ON SOILS AND PLANTS 383 
TABLE 4. ManGanesEe SAutts AppEpD To NUTRIENT SoLuTions ConTAINING 961 Parts 
PER MiLuion oF NUTRIENT SALTS 
Increase 
Average in weight Relative 
Parts per million of manganese dry weight | during the | increase in 
(grams) two weeks weights 
(grams) 
Davee swat ca heht Siete eee cee eet | 0367 .0073 100 
Manganese sulfate 
Tl go aco ove dn eos GARD BREE ee RET nee a .0392 .0098 134 
Be 0 Such 0.5 BTS CIEE Ea Ee IP iS ce ERIC op ea .0404 .0110 151 
HD« o.cie-6 6:9. 6-6 bb ere eee ee tee I Rete Pr 0423 .0129 177 
QO. 6 o sb ece ccd 5 kis See Ea na Ceo gr ieee .0400 .0106 145 
TOO PR ea case bbe Fas .0368 .0066 90 
Manganese chloride 
Toro 9 606.5 5 6-6 Abie eh SLR Aone ote te ee PG eee .0385 .0091 125 
& 3 avo) Aca @ Sie As STEN eae ee .0419 .0125 171 
5 UD. o4.0.68-08:88 Se on ee ee eee .0395 .0101 138 
OORT rt yr et Se ee .0387 .0093 127 
WODOs o'c's oie esc ieee BiG AN Gaerne one suber ren .0320 .0026 36 
Manganese carbonate 
PPMP rere rae SN es a .0367 .0073 100 
Bao wine die 8 a6. 6 Di Dice ee teen eae ene) oe .0376 .0082 112 
NO MMPPPRNED econ ees fio) o 0 ee .0387 .0093 127 
BO). oo dob 00/8 SR RO eS Ce aE CL te mee .0455 .0161 220 
It will be noticed that by this procedure it has been possible to show 
an actual decrease in the weight of the seedlings grown in the solutions 
of highest concentrations of the sulfate and the chloride. 
An examination of tables 3 and 4, giving the results of this series of 
experiments, shows that these results agree in general with those of the 
first series; that is, as the concentration of the manganese decreases, the 
total dry weight increases. The figures show clearly the greater toxic 
effect of the manganese in the absence of the endosperm. The results 
here reported agree closely with those of Miss Brenchley (1914). 
Effect of manganese compounds on wheat grown in soil 
- The determination of the effect of a given factor when added to the 
soil is complex. The effect of this factor on the growth of plants is but 
