This small educational and moralising volume on the subject of the tongue, written by the author of The Duty of Children to their Parents, contains a number of essays, one of which addresses the slave trade: "a subject, which is calculated to rouse every feeling of the human heart [...] upon which I wish to call forth all the energies of the tongue" (53). The essay is based on a series of visions, including an allegorical discussion between "Humanitus" and a slave ship captain, an "Invocation" to the British government calling for abolition, and a vision of hurricanes, shipwrecks, wars and disease striking the Atlantic world as divine vengeance for the slave trade.