For some time now, some of my on-line friends have advised me to provide a version of CassidySlangScam without the invective aimed at Cassidy and his supporters. In response to that advice, I am working on providing a glossary of the terms in Cassidy’s ludicrous book How The Irish Invented Slang with a short, simple and business-like explanation of why Cassidy’s version is wrong.
Daniel Cassidy, in his etymological hoax How The Irish Invented Slang, claims that the carnival slang term poke for a bag comes from the Irish póca, which means a bag or pocket. In reality, of course, it is the other way round. Poke is an ancient term in English for a wallet or money bag, which dates back to the early 13th century. It probably derives from some Germanic source via Old North French.
Incidentally, several of the words given by Cassidy here such as poc and poca are Scottish Gaelic, not Irish. They are different languages and there is little evidence of Scottish Gaelic being spoken in America in the 19th century.