In preparing this fourth edition, the text has been revised throughout and some slight rearrangement of the contents has been made, so that the course of instruction may follow a more rational order of development. For example, belladonna, stramonium and henbane have been put with the herbs, because they now consist of stems, leaves, flowers and fruits as do other herbs, such as lobelia. The insects, cantharides, mylabris and cochineal have been put immediately after the herbs, because they are whole insect organisms just as the herbs are whole plant organisms. Features ? Under quantitative analysis six new exercises have been introduced including analysis of herbal mixtures, ash and volatile oil determinations, yield of extractive to solvents and the testing of strophanthus ? A second appendix has been added, summarising those pharmacognostical numerical data which are now available