Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. More attention than usual is paid to the development of first principles. It was rather surprising to find how far the natural development of chemical conceptions coincides, on the one hand, with their historical development, and on the other hand, with the demands of rational pedagogics. The explanation of the fundamental conceptions - substance, solution, mixture, their properties and characteristics - not only forms the logical basis of chemical instruction, but makes possible, as well, the system atic description of the more important chemical operations and methods bf separation, which must be understood before a good knowledge of chemistry is acquired. The first third of the book contains a simple, experimental development of these general chemical relations, and the experiments chosen for illus trating and demonstrating these relations are performed, for the most part, with well-known substances. They suffice, at the same time, to make the beginner so well acquainted with such phenomena that a sound empirical basis is obtained for the systematic study of chemistry, and thereby a feeling of progress is obtained. In this way, the student acquires a certain amount of thorough knowledge, which is more advantageous for future work than a much greater accumulation of half - digested fragments of isolated facts.
