1977 saw the publication of "A Collection of Methods for Water Analysis", a three-volume work in ring-binder form compiled by W. Fresenius and W. Schneider for the GTZ (Deutsche Gesellschaft fUr Technische Zusammenarbeit), 6236 Eschborn 1, FRG. This publication was geared to the needs of a project in Algeria. More recently, the editors were requested by the GTZ to produce, on the basis of the previous collection of the water analysis methods, which was published in French, an updated and revised version to be used in different partner countries and for publication in 1985/86. This was not only to take account of advances in water analysis and instrumental techniques, but also to include simple methods of analysis for use in the field, and methods suitable for use in laboratories with relatively unsophisticated equipment. The approach envisaged by the GTZ was to divide up information on water, water supplies and water analysis into three broad groups, namely: 1. Simple modules on the physics and chemistry of water, water hygiene and water analysis capable of being understood and applied in practice by the layman using suitable chemi­ cals and equipment (W. Schneider). 2. Information to supplement work by Rump-Krist, also commissioned by the GTZ, on water analysis methods which could be used in laboratories with simple equipment, particularly in the Third World (Verlag Chemie, Weinheim, FRG, 1986).