The relation in which Dr. Rittenhouse now stood to the American Philosophical Society, of which he had attained to the honour of being the President, renders it proper that some account should be given, in this place, of an institution heretofore distinguished by its Transactions. The following are the leading features in its history.

This Society was instituted on the 2d day of January, 1769, by an union of two literary societies that had subsisted some time previously, in Philadelphia. In the same year this united body petitioned the general assembly of the province to grant them the privilege of erecting a building, suitable for their accommodation, on some part of the State-House square. But the Library Company of Philadelphia, also a very useful and respectable institution and a much older corporation, having about the same time made a similar application to the legislature, in their own behalf, the prayer of neither was then granted. The latter have, long since, erected for their accommodation a large, commodious and elegant structure[[247]], on a lot of ground purchased by them for the purpose, in the immediate vicinity of the public square originally contemplated for its site.

A second petition was presented to the general assembly by the Philosophical Society, for the same purpose, soon afterwards; though without success. But, finally, in pursuance of another application to the state legislature by the Society, for the same object, a law was enacted on the 28th of March, 1785; by which a lot of ground (being part of the State-House Square) was granted to them, for the purpose of erecting thereon a Hall, Library, &c. “for their proper accommodation.”

The ground appropriated by the legislature, for this purpose, contains seventy feet in front on (Delaware) Fifth-Street, (and nearly opposite the Hall of the Philadelphia Library-Company,) and fifty feet in depth; on which the Society erected, between the years 1787 and 1791, a neat, convenient, and spacious edifice: it was completed under the direction and superintendence of Samuel Vaughan, Esq. formerly a vice-president of the Society; and by means of this gentleman’s disinterested exertions, principally, somewhat more than $3500 were obtained from about one hundred and fifty contributors, towards defraying the expense of the building. Dr. Franklin gave at sundry times, towards this object, nearly $540 in the whole amount.[[248]]

The act of assembly of 1785 having, however, restricted the corporation of this Society, not only from selling or transferring, but from leasing, any part of the ground thus granted to them, or of the erections to be made on it, a supplement to that act was obtained, on the 17th of March, in the following year; authorizing the Society to let out any part of their Building, for such purposes as should have an affinity to the design of their institution; but restricting the profits arising from any such lease to the uses for which the Society was originally instituted. The cellars and some of the apartments in the house, have been leased accordingly; and the profits arising from these leases constitute a considerable part of the Society’s funds, which are of very moderate extent. The resident members pay to the Treasurer a small annual assessment, fixed by a by-law of the Society: these payments, in addition to occasional donations in money, made by members and others,[[249]] form the residue of the funds of the Society; besides which, they receive from time to time valuable presents, in books, astronomical and other instruments, &c. Their library, philosophical apparatus, and collections of various kinds, are now respectable.

The objects of this institution are readily comprehended, from its name; the style of the corporation being—“The American Philosophical Society held at Philadelphia, for promoting Useful Knowledge:” And with this view, in its formation, the fundamental laws (passed on the 3d day of February, 1769,) direct, that “The members of the Society shall be classed into one or more of the following committees:

1. Geography, Mathematics, Natural Philosophy and Astronomy.

2. Medicine and Anatomy.

3. Natural History and Chemistry.