chew the fat

今日取り上げるのは以前（11/1/2010）にも取り上げた慣用句で、昨日と同様にReader's Digest ３月号の記事 'Scamming The Scammers' に出てきた "chew the fat" です。
I live in London, so I thought I'd just pop round and give you the $900 in person. Be good to meet up and chew the fat. I stopped by your corporate offices in North London, only I couldn't find an office there. Just a cul-de-sac. What's the deal?
...
Oddly enough, that was the end of our correspondence.
今回は語源が気になったので、語源に触れている次の辞書の説明を引用します。
The American Heritage Dictionary of Idioms: Also, chew the rag. Chat in a friendly, leisurely way, as in Let's get together for coffee and chew the fat, or John and Dave spend hours just chewing the rag. Before the 1880s in Britain, chew the fat meant "to grumble or complain," and chew the rag also has been used in this way. Today both expressions are largely synonyms for a friendly talk or gossip session. Why this idiom uses fat and rag is not known, but some speculate that fat refers to juicy items of gossip and rag to ladies' sewing circles and the cloth they worked on while chatting.