This upper-division textbook describes the composition and evolution of material objects in the universe. The survey begins with a discussion of terrestrial materials and ends with the composition of quasars and distant galaxies. There are two main themes: chemical processes responsible for the abundances we observe, and nuclear processes in which the chemical elements originate. The author presents a total pedagogic synthesis of the subject, building on the basic information in the first chapters to lead into a fuller explanation of the composition of the planets and stellar and primordial nucleosynthesis. The later chapters treat the analytical methods of stellar and nebular spectra, and move on to the composition of stars and galaxies. The book is fully referenced and includes problem sets for the student.