Source: Hope, James. A Treatise on the Diseases of the Heart and Great Vessels: And on the Affections Which May Be Mistaken for Them : Comprising the Author's View of the Physiology of the Heart's Actions and Sounds, As Demonstrated by His Experiments on the Motions and Sounds in 1830, and on the Sounds in 1834-35. London: John Churchill, 1839.
Shown in this plate is figure 3, "the interior of the left ventricle and the mitral valve." Sprinkled around it are figures 4a-c, diagrams illustrating the book's description of valvular disease: "It is suggested to the young student to carry these diagrams, with their descriptions, in his pocket, until he is master of the subject."