"Clear" and "turbid" in Chinese phonology, part 4

[This is a guest post by W. South Coblin in response to these questions which I asked him about the distinction between qing 清 ("clear") and zhuo 濁 ("muddy; turbid") in Chinese language studies: 1. when and how it arose 2. how it functions within traditional Chinese phonology 3. how it correlates with concepts in […]