DEAR SIR: According to the directions of the Academy of Natural Sciences of Philadelphia, we transmit you a copy of the resolutions passed relative to your" Notice of the Academy," recently read before it. While we offer you our assurance of the pleasure afforded us in listening to the pleasing details of the" Notice," we would congratulate you upon the gratification you have been enabled to confer, not only upon the members of the Academy, but also upon all other persons interested in the progress of science, by the rescue from oblivion of facts connected with the infancy and growth of the Institution, which must become more and more valuable every year: as well as by the satisfactory manner in which the records of its more recent events and present condition are portrayed. With much regard, we remain your fellow-members, WM. S. VAUX, ROBERT BRIDGES, ROBERT PEARSALL.