Alcohol is prohibited over 2,337,500 square kilometres of Congo territory, the zone within which its sale is tolerated extending to only 12,500 square kilometres, where its abuse is guarded against by carefully devised restrictions, rigidly enforced. The sale of absinthe is absolutely forbidden in every part of the Congo Free State. It thus appears that, as the guardian of the welfare of its people, the Congo Free State has nothing to learn, either in theory or practice, from the most enlightened governments of the world. FOOTNOTES: [25] In the opinion of scientists, sleeping sickness is due to a trypanomous microbe, the propagating agent of which is the tsetse fly. CHAPTER XXVI TRADE, REVENUE, AND TAXES Among the earlier trading companies on the West Coast of Africa was the house of Regis et Cie., established at Banana in 1858, whose successors, Daumas, Béraud et Cie., were carrying on a considerable business when Stanley explored inland from the mouth of the Congo in 1878. The old Dutch house, the Afrikaansche Handels-Vennootschap, of Rotterdam, had a branch at Boma in 1860, and the Portuguese firm of Valle & Azvedo, and the agents of Hatton & Cookson, of Liverpool, opened trading depots near by a few years later. These firms had, however, very little direct trade with the interior of the Congo Basin, commerce in their early time being confined to the coast. Trade with the interior is almost entirely due to the Belgians. Before the Free State was founded the trade of Central Africa was chiefly in slaves. As a Belgian writer quaintly observes, the slave was at once the means of labour, the main capital, the vehicle of transport, the common currency, and the usual tribute given to satisfy the covetousness of native chiefs. The slave was the standard of wealth and the element of power. In order to estimate the influence of the slave trade as an economical factor in barbarous communities, and compare it with the trade _régime_ of civilisation, it would be necessary to imagine dealings in some object representing all these uses in our markets.[26]