Observations on the slave trade and a description Of some Part of the coast of Guinea, during a voyage, Made in 1787, and 1788, in Company with Doctor A. Sparrman and Captain Arrehenius, by C. B. Wadstrom, Chief Director of the Royal Assay and Refining Office; Member of the Royal Chamber of Commerce, and of the Royal Patriotic Society, for Improving Agriculture, Manufactures, and Commerce in Sweden