Pinning down a quote

[womzilla]

Huh--I'd never seen this in the original, though I had seen its target correctly identified:

It was Lord Melbourne . . . who said, "I wish I was as cock-sure of anything as Tom Macaulay is cock-sure of everything."

--anon., The Spectator, 30 November 1889.

(Amazingly, the Spectator included the Wikipedia links. Very forward-looking magazine, that.)