The work opens with a broad historical review of the microscope, tracing its evolution from simple seventeenth-century magnifying glasses to the sophisticated compound instruments of the nineteenth century. The author explains the fundamental laws of light, propagation, refraction, and reflection, detailing how spherical and chromatic aberrations distort images and how early opticians attempted to correct them through lens combinations and doublet designs.
A significant portion of the text is dedicated to the human eye, examining its dioptric mechanisms, chromatic errors, and the optical phenomena that govern visual perception. The narrative then transitions to Jabez Hogg's detailed analysis of Professor Abbe's theories of microscopical vision, aperture measurements, and the revolutionary role of diffraction in forming images of minute structures. The text contrasts dry objectives with water and oil immersion systems, establishing numerical aperture as the true measure of resolving power.
Subsequent chapters provide practical instruction on the handling and construction of microscopes, detailing the various stands, mechanical stages, and sub-stage condensers produced by leading English and Continental makers. The author examines the specific requirements for biological and bacteriological laboratories, emphasizing the necessity of precise fine adjustments and rigid mountings to eliminate vibration during critical observations.
The volume also addresses applied accessories, including polarizing apparatus, camera lucida drawings, micrometer scales for measurement, and goniometers for determining crystal angles. The latter sections explore the microscopic structure of various kingdoms, from minute vegetable cells and diatoms to animal tissues, protozoa, and mineral formations, offering exhaustive instructions on staining, mounting, and preparing specimens for examination.
Throughout the text, the author maintains a balance between theoretical optics and practical laboratory utility, illustrating the arguments with hundreds of detailed engravings. The work concludes with comprehensive tables of metrical measurements, thermometric values, and chemical formulæ, serving as a definitive guide for students and researchers of the Victorian era.
