This article about tracing American slang words to their Gaelic roots seemed interesting at first but by the end I was wondering what the odds were that so many slang words came from Ireland. By chance shortly after I finished the article, Grant Barrett emailed me a piece he wrote in response to the article and its subject, Daniel Cassidy.
Cassidy's theories are insubstantial, his evidence inconclusive, his conclusions unlikely, his Gaelic atrocious and even factitious, and his scholarship little better than speculation. In short, his book is preposterous.