A Note on the Effects of Copper Impurities in Distilled Water on Growth of Plants.

The observation was made in certain controlled nutrient solution studies with sugar beet and barley, that toxicity was associated with the supply of distilled water. The toxic element was referred to copper. The condition arose from storage of the distilled water in tin-lined copper tanks in which areas of exposed copper were evident. Direct analysis, by the colorimetric sodium diethyldithiocarbamate method (2),' showed that the water issuing from the tin-lined copper still was relatively low in copper content, but increased in concentration the longer the water was retained in the defective reservoir. The approximate concentrations of copper which may be found in distilled water and artificial nutrient solutions are presented in table I.