This pamphlet, published in Barcelona by Alexander and Madden, attempts to sensibilise Spanish public opinion to the continuing "complicated iniquities" (3) of the illegal transatlantic slave trade. The introduction summarises European and American abolitionist movements, while the text itself is a letter by Madden which details his eye-witness experience of colonial slavery in Cuba, and dismisses the idea of 'mild' slavery in the Spanish colonies. The authors argue that the abolition of slavery is the only sure means of stopping illegal slave trading to the Americas.