...alone the yield was a thousand tons per annum. It was proportionate in Holland, Prussia, Sweeden, and Germany. The practice of extracting nitre from beds is still kept up in Europe, especially in Prussia and Sweeden, where it (nitre) is received in the payment of taxes at a stipulated price. It is true that one or more cargoes of nitre may pass the inefficient Lincoln blockade, but as the suppl...