Theory of circulation by respiration

The author argues that animal heat produced by pulmonary combustion causes expansion of blood in the lungs, generating a vapor-driven pressure that propels blood toward the left ventricle; the essay recounts the author's discovery process, critiques prevailing cardiac-centric explanations, and presents simple experiments and analogies—rubber tubes, valves, inclined planes—to show how respiratory expansion plus the heart's valvular regulation produce circulation. It traces the hypothesis' development, responds to objections, and applies the idea to pathological states such as cholera, emphasizing physiological reasoning and experimental demonstrations.