The authors have in the following pages endeavoured to indicate the Chemical relationships, composition and properties of most of the better-known pigments. During recent years they have given a great deal Of attention to the examination of painters colours, and 'have from time to time found some difficulty in obtaining reliable information on the subject. This led to a considerable amount of work in obtaining and examining specimens of pigments, and it was felt that the information thus gained might usefully be published.
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