comet, and stated, that he (Mr. Walker) had been engaged in deducing the elements of the orbit of the comet, which accorded with results of European observers, but did not perfectly correspond with those of Prof. Loomis.

The following gentlemen were duly elected members of the Society:

PAUL BECK GODDARD, M.D., of Philadelphia.

W. H. C. BARTLETT, Professor of Natural and Experimental Philosophy, West Point.

WM. R. FISHER, M.D., of Philadelphia.

GEORGE M. WHARTON, of Philadelphia.

FRIEDR. WILHELM BESSEL, Director of the Observatory, Königsberg.

Rev. WM. H. FURNESS, of Philadelphia.

Captain FRANCIS BEAUFORT, R. N., Hydrographer to the Admiralty of Great Britain.

HARTMAN KUHN, of Philadelphia.

GEORGE WASHINGTON SMITH, of Philadelphia.

Stated Meeting, May 1.

Present, twenty-one members.

Mr. DU PONCEAU, President, in the Chair.

Mr. Vaughan, on presenting a transfer of page 524 of Schaaf's Syriac Lexicon (Leyden edition, 1717), &c., by Mr. Joseph Dixon, of Taunton, Massachusetts, on the plan of the transfer process of Mr. Dixon's invention, read sundry extracts of letters from him on the subject.

A notice of this invention was first published in the Salem Gazette, by the editor of that paper, on the 25th day of May, 1832; but the inventor has not yet made the process public.

The Committee, consisting of Mr. Walker, Dr. Patterson, and Mr. Bache, to whom was referred a paper, entitled “Observations on Nebula, with a Fourteen Feet Reflector, by H. L. Smith and E. P. Mason, during the year 1839, by E. P. Mason," reported in favour of publication in the Society's Transactions, which was directed accordingly.

The object of Messrs. Smith and Mason was to furnish a minute description of some of the principal nebulæ in the heavens, in order that future changes in their appearance, should any occur, may be detected. The process employed was- -1st. To prepare an accurate chart of all the stars in and about the nebula, capable of micrometrical measurement. 2dly. To fill in with the smaller stars down to the minimum visibile, by estimation. 3dly. To lay down the nebula on this chart with such care and precision, that the errors of its delinea

4

tion may not far exceed those of original vision. The author, Mr. Mason, states at length the expedients used to effect the latter purpose, viz.,-the drawing of lines of equal brightness, as a guide to the engraver; the examination of each portion of the nebula by several persons; and, lastly, the repeated comparison of the drawings with the original, on successive evenings, till no further improvement seemed to be practicable.

The telescope used by Messrs. Smith and Mason, was of their own construction. It was 14 feet in length, and had 12 inches clear aperture, being a Herschelian, mounted somewhat rudely on the plan of Mr. Ramage. The difficulties experienced by Messrs. Smith and Mason, as amateur artists, in casting and polishing specula at New Haven, are stated in detail. The telescope was capable of separating Orionis, Bootis, 7 Virginis in 1838, à Ophiuchi, and others of a distance of less than 1". For such purposes, however, the use of diaphragms was necessary, owing to an imperfection of the casting, and the full light of the telescope could not be employed. This circumstance directed their attention to the subject of this paper.

A cursory examination of the principal nebulæ described, and, in some instances, figured by the Herschels, pointed out discrepancies between their descriptions and present appearances, which must be attributed either to a change in the nebula themselves, or to the want of sufficient minuteness of examination on the part of the Herschels, whose object was rather the formation of a complete catalogue of the nebulæ in the heavens, than the full and perfect description of any of the individuals. Thus, the paper contains a drawing of the "nebula trifida," h. 1991: the triple star does not occupy the same position in the cleft as given in the figure in Sir J. F. W. Herschel's paper, Phil. Trans. 1833, but rather adheres to the left of the three divisions; and what is more remarkable, the small star about 30' north of this triple star was surrounded with a nebula not much inferior in size and brilliancy to the "nebula trifida." A drawing is also furnished of the nebula, h. 2008 (the shape of which resembles the capital Greek 2), with a critical examination of Herschel's figure of the same.

The most remarkable discovery of Messrs. Smith and Mason, was that of the junction of the two nebulæ, h. 2092 and 2093. These great nebulæ, or "milky ways," aré described on several occasions by the elder Herschel, and are also described and figured by the

younger. They are distant about two-thirds of a degree from each other. Messrs. Smith and Mason, however, distinctly saw the nebulous matter extending from one to the other, making the whole one conspicuous nebula of more than a degree in length, being among the most remarkable in the heavens, and inferior only to the great nebulæ of Orion and Andromeda.

Mr. Mason remarks, that it is difficult to conceive how the com

panion of the nebula trifida, and the junction of the two last men

tioned, should have been overlooked by such observers as the Herschels, with instruments so far superior to his in optical capacity. The supposition that the nebulous space, noticed by Messrs. Smith and Mason, was not brought under the immediate inspection of the Herschels, seemed inadmissible. That the greater clearness of the atmosphere of New Haven should more than compensate for the inferior light of the telescope employed was hardly probable; the only remaining supposition was, that the nebulous matter, in the space examined by all these observers, has recently undergone a change in shape and brilliancy.

In making the chart of the stars to which the nebulous space is referred, Mr. Mason used the ten feet Dollond refractor, of five inches aperture, belonging to the Philosophical Department of Yale College, with a Dollond's illuminated line micrometer. With this he has determined the relative position of the stars down to the 16th magnitude, by repeated observations, and has furnished a catalogue of the correct places of 15 stars in the first chart, 30 in the second, and 182 in the third.

Dr. Dunglison stated that the horse, with the filaria in the aqueous humour of the eye, to which allusion was made at the last meeting (see Proceedings, p. 200), was in the city, and that he had had an opportunity of verifying the statement then made. Dr. Dunglison referred to several similar cases, most of the observers believing the entozoon to be a filaria papillosa, but some a lesser strongylus.

Dr. Hays referred to cases of entozoa found not only in the eye, but in other parts of the body, and alluded briefly to the practicability of the germs being received from with

out.

Dr. Chapman, as chairman of the Committee to collect do

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cuments connected with the political and historical state of the country, reported that he would be able to procure for the Society the Correspondence of Robert Morris. He farther stated his expectation to be able to present important documents from Virginia, calculated to throw valuable light on the history of the colony and the country.

Mr. Vaughan reported the death of Mr. William Maclure, a member of the Society, who died in Mexico on the 23d of March last.

Dr. Dunglison, Reporter, presented No. 11 of the printed Bulletin.

Stated Meeting, May 15.

Present, twenty-six members.

Mr. DU PONCEAU, President, in the Chair.

The following donations were received:

FOR THE CABINET.

A Plaster Bust of Alexander Hamilton.-From Mrs. Astley. Specimens of Crystallized Carbonate of Lime and Pipe Iron Ore ; found at the Iron Works of William Reed, Perrysville, Mifflin County, and by him deposited at the Bank of the United States, with N. Biddle, Esq.-From Mr. Dunlap, with the assent of Mr. Biddle.

Two Daguerreotype Portraits, the one of Mr. Du Ponceau, the other of Mr. Vaughan, taken by Mr. Cornelius.-From Dr. Goddard. The Committee to whom was referred the paper of Dr. Hare, entitled "Engraving and description of an apparatus and process for the rapid congelation of water," &c., reported in favour of its publication in the Society's Transactions, which was ordered accordingly.

A communication was read from Professor Bonnycastle, of the University of Virginia, entitled "On the insufficiency of Taylor's Theorem, as commonly investigated, with objections to the demonstrations of Poisson and Cauchy, and the as