The Lethal Action of Soluble Metallic Salts on Fishes

Abstract

The work of several years on the fauna of streams polluted by lead-mining(1. 2, 3) has revealed the fact that the destruction of fish-life in such streams is neither a matter of starvation nor emigration for lack of food, nor of spawn-destruction, but is a direct consequence of the action of lead-salts in solution (probably as the sulphate) upon the fishes themselves. Further, experiments both in the field (using fish cages in the polluted streams) and in the laboratory (using filtrates of the flood waters and chemical solutions) have clearly demonstrated that one part of lead in three millions of water may be lethal to minnows, sticklebacks and trout. It seemed worth while, therefore, to investigate the physiological nature of the reaction in order to discover whether it followed the normal course of a toxic reaction.