A Ms. Catalogue of Minerals by the Comte de Bournon has lately come into my possession. From internal evidence the date of the volume may be fixed at 1811—three years after the publication of the Count's Traité de Minéralogié. The collection of minerals described in this catalogue was made for the Government of Brazil ; if the collection still exists, a careful comparison of some of the specimens in it with their descriptions in the catalogue would clear up some obscure points and lead to useful results. Without this aid to a clear understanding of Bournon's descriptions, many interesting facts may be gathered from the manuscript in question. It is, however, a voluminous work extending over 356 pages, and illustrated with a large number of careful drawings of crystalline forms. The author was a very laborious compiler of catalogues. One of these, known to the present writer, is still in existence in the Town Hall of Devonport, along with the magnificent collection of minerals (the St. Aubya collection) to which it refers. A few notes on the Brazilian catalogue may not be without interest.