Complex sentence: Corpses and their component parts became a commodity, but although the practice was hated by the general public, since corpses were not legally anyone's property, this clandestine method of securing them for study occupied a legal grey area.
Split into simpler sentences: Corpses and their component parts became a commodity, but although the practice was hated by the general public, bodies were not legally anyone's property. This clandestine method of securing them for study therefore occupied a legal grey area.