Patrick Matthew wrote in the preface to his 1831 book 'On of Naval Timber and Arboriculture':
The anonymous author of the Edinburgh literary Journal (1831), who wrote a review of Matthew's book, found that completely implausible and said as much when they wrote that Matthew had copied the work:':
'...in the original works on planting, from whence they are copied, namely those of Miller, Marshal, Pontey etc, authors that Mr Matthew never had the "curiosity" to examine.'
Therefore, the anonymous author of that review was, in effect, claiming that Matthew had plagiarized the work of others, which he thought Matthew claimed not to have read.
But did Matthew claim in the above paragraph from his preface that he had not read those works. I think not. Because, on a careful reading he seems to be saying that others who had not read those works would find Matthew presumptuous.
To date, therefore, it seems that there is no evidence that Matthew (unlike Charles Darwin) ever wrote a deliberate falsehood (lie).
Indeed, seven days later the Edinburgh Literary Journal (1831, July 9th, p. 28) describe Matthew as being honest:
"Our friend the Editor has already found our familiar of considerable use. Its swiftness fits it admirably for reconnoitring the operations of any enemy. Last Monday we sent it across to Perthshire, that it might keep an eye upon Mr Patrick Matthew's motions. The honest gentleman had cut a most respectable bludgeon from one of his crab-trees, but was sitting irresolute in his garden chair."
That Matthew's own imaginary stick is imagined to have been cut from his crab apple tree is unlikely to be of insignificance to whoever implied, jokingly, on July 9, 1831, that Matthew was an enemy, since on pages 283 to 285, Matthew (1831) explains that Siberian crab apple wood is the strongest apple timber by far.
Why was Matthew described by the the Edinburgh Literary Journal as an enemy? There are many possible reasons for that assertion - from Matthew's natural selection heresy on the question of the origin of species, his mocking of the Scots hero Sir Walter Scott, to his radical libertarian politics They are all discussed in Nullius in Verba: Darwin's greatest secret.