V. While Section V., Chemistry pure and applied, is more extensive

than the other six combined, it is the least satisfactory to the editor. Besides pure chemistry it comprises works in every department of chemistry applied to the arts, but not works on the arts themselves ; thus agricultural chem- istry is given place, but not agriculture : pharmaceutical chemistry, physi- ological chemistry, etc., find place, but not the sciences of pharmacy and medicine. It is of course often impossible to draw the line sharply and in doubtful cases the tendency has been to include rather than exclude ; hence many works on technology are included especially when chemistry lies at their foundation. It is probable, however, that this has not been done uniformly, owing to the difficulty of selection.
Readers should not expect to find in this Section complete lists of the works of a given author ; though some pains have been taken in the case of prominent men to catalogue their writings fully. (See under Berzelius,
PREFACE. Vlt
Fresenius, Liebig, Johnston, Orfila, Stockhardt, etc.) The names of many eminent chemists will be found wanting in Section V. simply because they have published no independent works, although voluminous contributors to periodicals.