A detailed analysis of the 'origins' of the quote is at the following link:
The Truth About Tytler
It is an excellent analysis and rather disproves the nebulous assertion that Tyler/Tytler made the quote in a book that he didn't write.
aarable,
If you were my researcher I'd fire you for incompetence. You actually have no idea of how to carry out research or how to check the veracity of your statements. The Internet is an excellent tool for research as it saves me a lot of time going into the Bodleian Library, but you must not take everything you read at face value.