Vlll PREFACE Laboratories of the Italian Customs Department were embodied in a Manual of Technological Analytical Chemistry, which was published in 1904 and has been out of print for some years. With a similar object the present treatise has been compiled. Much still remains to be done, and the methods now described cannot be regarded as final; in the present state of knowledge they do, however, satisfy prac- tical requirements with some degree of sufficiency. In the laboratories under my direction, most of the methods have been repeatedly tried and many of them carried out and studied almost daily by specialists who are already well known from their published work and are now assisting here with their valuable co-operation. To these and also to those colleagues and friends who have furnished unpublished analytical data and particulars of methods based on their practical experience, I desire to express my gratitude. This treatise is divided into two volumes. The first deals with the analysis of potable waters, chemical products, fertilizers, cement materials, metals and alloys, fuels, tar and its derivatives, mineral oils and I'utty substances and the industrial products derived therefrom. The second treats of flesh foods, milk products, flour and starches, sugars and saccharine products, beer, wine, spirits and liqueurs, essential oils, turpentine, var- nishes, rubber, tanning materials, leather, colouring matters, and textile fibres and fabrics. For each product considered a brief statement is first made of the different cases and the analytical problems commonly presenting themselves, as well as of the investigations and determinations to be made to .solve them. Detailed descriptions are then given of the methods to be followed. Some- times methods for groups of allied substances, to which they are applicable in general, are collected in one; and the same sub-chapter. As a rule but one method or at most two methods arcs given for each separate test or determination ; when it is deemed necessary to give a greater number, the reason for this is stated, and the. cases indicated in which ones method rather than the others should be followed. In some instances mention is made of details to be observed in special cases or of doubts which exist as to the accuracy of the methods, any factors and conditions influencing the results being pointed out. Whether the methods have been adopted by official or other bodies is also stated. Next are given criteria and standards, with the aid of which the indus- trial, commercial or hygienic value of the product may be ascertained from the analytical data obtained. For the same purpose tables are given con- taining examples of the analytical results relating to the ordinary com- mercial qualities of the product, It is my hope that this publication may be received cordially by Italian chemists, to whom I shall be grateful for suggestions of improvements or additions. G. VITTORIO VILLA VECCHIA. ROME.