[5] In January 1782, Irving was working as a surgeon on Prosperity, a British slave ship owned by John Dawson.
[2] Dawson went on to give Irving his first captaincy on Anna, a slave ship that was registered in Liverpool in April 1789.
He also wrote: "O I hope you can feel for us, first Suffering shipwreck, then seized on by a party of Arabs with outstretched Arms and Knives ready to stab us, next stripped to the skin, suffering a Thousand Deaths daily, insulted, spit upon, exposed to the Sun and Night Dews".
In December 1790, he had become the captain of another of Dawson's slave ships, Ellen, which set sail for Africa on 3 January 1801 from Liverpool.
[11] James Baillie, her third mate, but by then the ranking officer, replaced Irving as master, and Ellen arrived at Trinidad and Tobago on 11 January 1792.
The letters, intended only for private consumption, offer a unique account of life aboard slave ships in the 18th century.