A collection of short, accessible essays that explain scientific concepts, report recent discoveries, and correct popular misconceptions across zoology, geology, medicine, and technology. Through clear explanations and anecdotes the author discusses the scientific method, the value of curiosity, laboratory work and public attitudes toward science, and specific topics such as infectious diseases, parasites and vectors, fossils and extinct creatures, gems and pearls, glaciers, animal variation and selection, and photographic and luminous phenomena. Interspersed are reflections on practical applications, experiments, ethical issues, and reminiscences of fellow scientists, all aimed at making technical subjects intelligible to general readers.