For some time it had been known that Frances Reynolds, the sister of Sir Joshua Reynolds and a correspondent of the great Samuel Johnson, had printed as a pamphlet in 250 copies, an essay on taste. Very little was known of it, however. It seemed to be quoted by James Northcote in his early nineteenth-century Life of Sir Joshua Reynolds, but none of the quotations ever seemed very helpful; and people began to suspect that either Northcote was mistaken about the source (i.e., mistakenly thought the text he was quoting was by Reynolds) or he was quoting an early draft that may have been very different from the one actually printed. (It turned out they were right.)
In the meantime, scholars were trying to hunt down another, and even more mysterious, work of Reynolds's, which she had sent to Johnson for comments. Johnson had responded (8 April 1782) kindly but critically. The letter everyone had access to was that printed by Croker and later by Hill:
Your work is full of very penetrating meditation, and very forcible sentiment. I read it with a full perception of the sublime, with wonder and terrour, but I cannot think of any profit from it; it seems not born to be popular.
Your system of the mental fabric is exceedingly obscure, and without more attention than will be willingly bestowed, is unintelligible. The plans of Burnaby will be more easily understood, and are often charming. I was delighted with the different beauty of different ages.
I would make it produce something if I could but I have indeed no hope. If a Bookseller would buy it at all, as it must be published without a name, he would give nothing for it worth your acceptance.
High and low scholars looked for this otherwise unknown novel or short story about the plans of Burnaby. It never came to light.
Which is not surprising, as there was no Burnaby. Johnson's actual letter never said anything about the plans of Burnaby; it was a faulty transcription. The actual letter had, instead of 'The plans of Burnaby', 'The Ideas of Beauty'. The Burnaby story was really the essay on taste!
In any case, having more information in hand it was possible to identify the work. You can read it, and, in the introduction, James Clifford's account of the history of the work, at Project Gutenberg. It strikes me as a nice little parable for all scholars everywhere. Every discipline has its own versions of the plans of Burnaby, whether on a small scale or a grand one -- that stunning little piece of evidence that sends you on a wild goose chase because it is, unbeknownst to you, all wrong. Beware the plans of Burnaby!