WATER FILTRATION VS. CHLORINATION

To the Editor:  I have noted with interest the editorial which appeared in the October 31 issue of The Journal entitled "Water Filtration vs. Chlorination." Owing, however, to the occurrence of a factual error in the reference to the 1892 epidemic of cholera in Altona, Germany, and the consequent reflection on the effectiveness of filters in the purification of water, it is thought that you might wish to present the following comment to your readers.The cholera epidemic occurring in Germany in 1892 was the first practical demonstration of the effectiveness of filtration in the prevention of water-borne disease. The city of Hamburg, supplied with unfiltered water from the Elbe River, experienced a severe epidemic of cholera, whereas no such epidemic occurred in the neighboring community of Altona, served with the same water after filtration through slow sand filters. Furthermore, the editorial mentioned may be misleading in that it implies