Coleridge on Ballads

Where did Coleridge remark this? I'm hoping it was in conversation, or in a lecture, and that it has not otherwise been recorded (offhand I can't place it otherwise; but I may well be wrong about that):

There are many masons why ballads are likely to be better than any other species of poems. As being composed for the people, they would be in the language of the people, the language of life and passion. Passing from one recitor to another, from generation to generation, frequent additions would be made, and such only as improved the poem would adhere to it. And as we heard well remarked by Mr. Coleridge; in oral recitation all the feebler parts would be dropt in process of time, and hence they have obtained that boldness with which they so frequently open, and those exquisite transitions which we so justly admire; while all other compositions of the same age are weakened by prolixity.
['Scottish Historical and Romantic Ballads', The Annual Review for 1808 7 (1809), 457]