Moritz Nagel (1808–1871): A faceless name in the history of the adrenal glands.

This article focuses on the historical identification and attribution of the introduction of the terms Rindensubstanz (cortical substance) and Marksubstanz (medullary substance) in reference to the adrenal glands. It establishes that Moritz Nagel (1808–1871), a student of the German physiologist and anatomist Johannes Peter Müller (1801–1858), was the author of an 1836 article that first published these terms, derived from his 1834 medical dissertation. Although Nagel’s work was the first printed description distinguishing the adrenal cortex and medulla, both Nagel and Jakob Henle acknowledged that Müller had previously observed and described this anatomical distinction by 1832. Consequently, the article concludes that credit for this discovery should be jointly attributed to Müller and Nagel, recognizing Müller’s prior findings and Nagel’s role in formally publishing and illustrating them.