LABORATORY IJZET.IOIB OF INORGANIC CHEMISTRY -- 1909, -- PREPACE. THIS book outlines a course of laboratory work which is essen- tially synthetic in fiature and is designed to aid in acquiring a more adequate knowledge of inorganic chemistry than is to be obtained by practice in chemical analysis alone. The need of supplementing the work of analytical chemistry in such a way has indeed been recognized inmost chemical laboratories of the German technical schools and universities, in fact such instruction still persists as a part of the classic method of teaching chemistry. To-day a training according to these lines is considered de- sirable even for those students with whom chemistry is a minor subject. It has been the aim of the authors to enlarge the choice of suitable experiments by publishing the procedures which they have tested and found satisfactory in their own laboratories in the course of a number of years experience. The experimental part of the book is given in relatively com- plete detail, because in our opinion this does not materially lessen the self-reliance of the student, who has, as a rule, but a limited time at his disposal. The beginner obtains ample oppor- tunity for acquiring manipulative skill and for exeriising inge- nuity, in the carrying oh of the work and in modifying and improving the directions to correspond to the facilities at hand others who need particular preparations as starting material for further investigation can appreciate directions in which technical difficulties are guarded against. To aid in the study of the theoretical relations brief general discussions are interspersed throughout the book as well as ref- erences to the original literature and the text-books of inorganic and theoretical chemistry which should be freely consulted. As regards the arrangement of the material, we have departed from the disposition which is common to-day of treating the compounds in connection with the groups of elements. We have chosen to base the classification upon the different types of iii iv AUTHORS PREFACE. combination, and thereby have returned to the older usage. Among the early authors Th6nard in 1813 writes La mbthode, ,que jai constamment suivie, consiste h proceder du simple au com- pose, du connu Ec linconnu, Ec rdunir duns un mme groupe tous les corps analogues, et h les ttudier dabord dune maniBre gtnerale et ensuite dune manikre particdidre. Gmelin in 1817, however, took a different stand and in his Handbuch arranged the com- pounds according to the elements, and thus introduced the sys- tem of classification which has been followed by nearly all of his successors. Even to-day Gmelins reasons for departing from the older method of treatment probably hold equally well as regards elementary books for beginners the older method scatters the compounds of a single element in such a way that the student fails to get a distinct, coherent picture. This book, however, is intended primarily for those who have passed beyond the more elementary stage in their study of chemistry, so that it does not seem to us to be too daring to make the experiment as to how well our modern, inorganic chemistry will fit into the older framework. It seems as if thereby, aside from the old advan- tage of a better comprehension of analogous methods of prep- aration and analogous properties, there results a particularly intimate amalgamation of experimental and theoretical chemistry, for in this way we advance, as it were, from a one compo- nent system to one of several components...