Dr Gy, a pioneer in every sense of the word, has spent 50 years studying the best way to take a truly representative sample. His greatest achievement perhaps has been to introduce science into the black art of sampling. The now famous and widely used formula bearing his name means that sampling is no longer a lottery but an essential analytical tool. This very readable and practical book, written by Pierre Gy himself, is the first simple guide to Pierre Gy’s method to be translated into English. Although Dr Gy’s formula was originally developed for the sampling of solid material in mines, etc., the theoretical arguments are equally valid for the sampling of liquids and multi-phase media. This book is as interesting as a historical perspective as it is useful for the practising modern day analyst.