This Spanish abolitionist text examines precedents for the abolition of slavery in the colonial legislation of other European countries, in order to encourage Spain to follow the example of Britain, France and other European countries in abolishing slavery in its colonies. Ahumada gives figures to show the numbers of slaves emancipated in 1833 in major British colonies such as Jamaica, Antigua, Guyana and Barbados, explaining how abolition was prepared and implemented through colonial law (including the apprenticeship system, abandoned in 1838). Particular attention is given to Jamaica, because of its proximity and similarity to Cuba. The recent end to slavery in the United States is also examined by Ahumada from a legal perspective, as well as the abolition of slavery and its aftermath in the colonies of France, Denmark, the Netherlands, Portugal and the former Spanish colonies of Venezuela, Ecuador and Peru. In this way, Ahumada intends to secure for Spain the "immense advantage" (165) of having an overview of the entire problem of abolition.