The Bactericidal Power of Nesfield's Method of Water Purification

I UNDERTOOK the following investigation at Lieutenant Nesfield's request, and although I found a bactericidal power for iodine on B. subtilis somewhat lower than that which he determined, yet the experiments afford strong evidence of the value of his processf for sterilizing water for surgical purposes and confirm all his other results:? 1. One tablet of mixed iodide and iodate of sodium weighing two grains and one two-grain tablet of citric acid were dissolved in two ounces of distilled water and the free iodine resulting estimated with standard sodium thiosulphate. It was found that all the iodine was liberated and the quantity agreed with the theoretical value given by the formula :? 5 Na I + Na I Os + 2Ci (COOH)g = 3 I2 + 2Ci (C00N.). + 3H80. ~~~