A case of sirenomelia, or mermaid syndrome, with a folding plate

A striking medical dissertation by Swedish physician F. Josef A. Rossi (1774–1854), documenting a rare case of sirenomelia, or mermaid syndrome, a congenital condition in which the fetus’s legs are fused together, resembling a mermaid’s tail.

Rossi, who later became personal physician to King Charles XIII and crown prince Charles August, records the case in detail and illustrates it with a folding plate. This early medical account reflects the fascination of physicians with unusual malformations in an era when such cases were often both scientific puzzles and public curiosities.

Copies of Rossi’s dissertation are exceptionally scarce, making this a valuable addition for collections focused on the history of medicine, teratology, or congenital anomalies. Its combination of rarity, royal association, and visual documentation makes it an especially desirable piece.

Don’t miss the opportunity to acquire this rare medical dissertation—a unique witness to how 19th-century science sought to explain the extraordinary.