E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
While Lockhart was writing Valerius, he was in the habit of taking walks with Professor Wilson every morning, and of supping with Blackwood at Ambroses, a small tavern in Edinburgh. One night Lockhart said, What a pity there has not been a short-hand writer here to take down all the good things that have been said! and next day he produced a paper from memory, and called it Noctes Ambrosianæ. That was the first of the series. The part ascribed to Hogg, the Ettrick Shepherd, is purely supposititious.