Complex sentence: Tornwaldt's disease was noted by Mayer in 1840 in autopsy specimen but founded as a pathologic entity by German physician Gustavust L. Tornwaldt in 1855.
Split into simpler sentences: Tornwaldt's disease was noted by Mayer in 1840. He noted it in an autopsy specimen but founded as a pathologic entity by German physician Gustavust L. Tornwaldt in 1855.