1874. This volume contains the essays on the subject of physics. It relates to physics, or natural philosophy. It contains, in the most concise manner possible, must information in science and art that must otherwise be sought in numerous volumes on those subjects. The work is original in conception, comprehensive in plan, bold in character, vigorous in style, exhaustive in research, forcible in argument, poetical in dictation, and erudite in treatment. It challenges the scrutiny of savans, it is readable and instructive, and will repay many perusals.