HOWTO: Search Pidgin's logs for a regular expression

I wanted to search all of Pidgin's logs for mention of a subject I remembered was discussed a few months ago.

From within the directory for Pidgin's log files - ~/.purple - I tried the following command:

grep -R <regex> *.txt"

Sadly this failed miserably so I asked for help. Immediately someone came up with the answer:

grep -R <regex> **/*.txt