The work opens with a rigorous account of the elementary constitution of matter, treating atoms and molecules, the relations between force and matter, atomic theory, chemical analysis and synthesis, and the application of spectrum analysis to gases, vapours, and stellar composition. It then surveys microscopic botany and marine forms, outlining structure, development, and reproductive processes across algae, fungi, lichens, Characeae, liverworts, mosses, ferns, horsetails, rhizosperms, club-mosses, and the general anatomy of flowering plants. Descriptions are supported by discussion of observational methods and numerous detailed illustrations that record form and microscopic structure.