Third. All my rough material for microscopic research, as contained in small boxes, paper, vials, and larger boxes, containing large masses marked with chalk, Richmond, Petersburg, Georgia, Florida, etc. .... Upon receipt of these materials the Society appointed a committee consisting of Augustus A. Gould, John Bacon and Silas Durkee to report on the bequest. On the basis of their reports (Proc. Boston Soc. nat. Hist. 6:194-200. 1857.) samples of diatoms were contained in the materials described in the first, second and thirds parts of the bequest. Bacon's report on the "Microscopical Collection" indicated that it contained 24 octavo slide boxes (Table 1), and it generally described the contents of 19 of them and specified that 550 slides were contained in 21 boxes. A description of the three octavo boxes unaccounted for in Bacon's report was misplaced into Durkee's report on the algae; these boxes contained 69 slides but apparently no diatoms. The only disagreement between the original descriptions of these 24 boxes and the 24 octavo volumes found in the Farlow Herbarium in 1976 is that Bacon reported that two of the boxes contained "Test Objects and miscellaneous Organic Bodies," whereas I have found the collection to contain only a single box with this title. In that none of the 24 numbered volumes is missing I believe Bacon's report was in error. In addition to the formally boxed slides, Bacon indicated that the collection contained more than 800 "specimens mounted on glass slides" and 200 other specimens "mounted as opaque objects." Assuming these 800+ and 200 specimens represented an equal number of slides, the total number of slides contained in the original bequest was minimally 1,619.