The method therefore has been adopted only after serious reflection and has been directed mainly by practical considerations. Recent cases which have either been reported or come to the knowledge of the author have been given, with particulars as exact as possible. Cases dating back some time have been omitted intentionally so as to exclude everything which did not correspond with the present conditions of industry and trade. Historical facts only receive consideration in so far as they are fundamentally important and necessary for the sake of completeness. The details given in Part I of actual instances will supply material for fresh efforts, renewed investigation, and new points of attack. INDUSTRIAL POISONING PART I _DESCRIPTION OF THE INDUSTRIES AND PROCESSES ATTENDED WITH RISK OF POISONING; INCIDENCE OF SUCH POISONING_ I. THE CHEMICAL INDUSTRY GENERAL CONSIDERATIONS AS TO INCIDENCE OF INDUSTRIAL POISONING The chemical industry offers naturally a wide field for the occurrence of industrial poisoning. Daily contact with the actual poisonous substances to be prepared, used, stored, and despatched in large quantity gives opportunity for either acute or chronic poisoning—in the former case from sudden accidental entrance into the system of fairly large doses, as the result of defective or careless manipulation, and, in the latter, constant gradual absorption (often unsuspected) of the poison in small amount. The industry, however, can take credit for the way in which incidence of industrial poisoning has been kept down in view of the magnitude and variety of the risks which often threaten. This is attributable to the comprehensive hygienic measures enforced in large chemical works keeping abreast of modern advance in technical knowledge. A section of this book deals with the principles underlying these measures. Nevertheless, despite all regulations, risk of poisoning cannot be wholly banished. Again and again accidents and illness occur for which industrial poisoning is responsible. Wholly to prevent this is as impossible as entirely to prevent accidents by mechanical guarding of machinery.