Critical and Historical Essays contributed to the Edinburgh Review, 5th ed. in 3 vols. (London: Longman, Brown, Green, and Longmans, 1848). http://oll.libertyfund.org/titles/363,
Collected in these three volumes are essays and book reviews Macaulay wrote between 1825 and 1841 for the Edinburgh Review.
The text is in the public domain.