The first edition of this book (1958) described an analytical situation which had existed for a number of years for maintaining quality control on vulcanizates of natural rubber although the situation had recently been disturbed by the introduction of a range of synthetic rubbers which required identification and quantitative estimation. For the former purpose 'wet' chemistry, based on various imperfectly understood organic reactions, was pressed into service. Alongside this was the first introduction of instrumental analysis, using the infrared spectra of either the polymers or, more usually, their pyrolytic products to 'fingerprint' the material. The identification of a range of organic accelerators, antioxidants and their derivatives which had been intro­ duced during the 1920s and 30s was, in the first edition, dealt with by a combination of column chromatography and infrared spectroscopy or by paper chromatography. Quantitative procedures were, however, still classical in the tradition of gravimetric or volumetric assays with an initially weighed sample yielding, after chemical manipulation, a carefully precipitated, dried and weighed end product, or a solution of known composition whose weight or titre, as a percentage of the initial sample, quantified the function being determined. The second edition of this work (1968) consolidated the newer techni­ ques which had been introduced in the first without adding to them although, in other applications of analytical chemistry, instrumental analysis had already brought about a transformation in laboratory practice.