Dr Pinckard's observations on slavery in the Americas, made during his voyage to Barbados and Guiana as a naval surgeon in 1796, were cited by abolitionists such as Wilberforce and Clarkson, and mentioned in British parliamentary debates. The Notes on the West Indies describe plantation slavery in the Americas as generally an inefficient and uncivilised society, with repulsive aspects. Pinckard describes many plantations as happy and well-run, but he is also horrified by public sale and ill-treatment of slaves. Despite these inconsistencies, his detailed notes on the punishments inflicted on slaves became useful eye-witness statements for abolitionists in Europe.