A couple of links to Chinese practice -perhaps.

[daifu-orchid (imported)]

There seems remarkable doubt about the practice in China, given that it happened so often for so long.

http://listverse.com/2015/10/10/10-fate ... n-dynasty/

http://blog.mailasail.com/peregrina/52

Both include descriptions of the procedure, one early, one late.

(Word to the wise, regarding the first of these links: there appear to be two blocks of web code which no not execute on my browser. They don't affect the display, and do not appear to contain anything malicious. Be careful, but it's probably nothing bad. But then again, not a lot gets at Tor/Linux.)

[Paolo]

I had no problem with them.

Thanks.