VI. The globular Bodies. These appear to be merely portions of the stone, embracing probably all its principles, which have been melted by intense heat, and being surrounded by solid matter, have become more or less globular, like the globules of metal which appear dispersed through a flux in a crucible, after an operation with a very high degree of heat, upon a very refractory metal. The globular bodies in this stone, although not attractable by the magnet, readily become so by being heated with the blow pipe. Is the iron in them too highly oxidized, to admit of attraction, and, are they partially reduced by ignition on charcoal? Finally, is there not reason to conclude, that these meteoric stones, originally presented nothing distinguishable by the eye, except pyrites and the enveloping earthy matrix, that by the operation of heat, the irregular black masses have been produced, by a partial decomposition of the pyrites, that by a still more intense heat in certain parts, the pyrites have been altogether decomposed, and malleable iron produced, that the crust is produced by a mere oxigenizement and vitrification, that the difference of colour in the earthy part, is owing to the unequal operation of heat, the pyrites being left, in some places, especially in the white spots, almost wholly undecomposed, and that the globular bodies have been formed by a complete fusion of certain portions, by intense ingition? Yale College, January 14th, 1808. POSTSCRIPT. February 22, 1808. In Nicholson's Journal for October, 1806, (No. 61, p. 147,) is an abstract of a memoir, by A. Saugier, taken from the 58th volume of the Annals of Chemistry, in which the author asserts the existence of a new principle in meteoric stones, viz. chrome. Before adverting to this subject it will be well to point out another assertion in M. Saugier's memoir, which appears Y to have been erroneously expressed. After remarking that all chemists who have examined meteoric stones, "have obtained similar results" he enumerates the principles which have been discovered in them, and says they are, "silex, iron, manganese, sulphur, nickel, with a few accidental traces of lime and alumine.' It seems plain that manganese has here been carelessly written instead of magnesia, for, neither Mr. Howard, nor any of the able chemists who succeeded him in the examination of meteoric stones, before M. Saugier, ever found manganese, but constantly magnesia, and as magnesia is not mentioned at all by this latter chemist, I think it plain, that magnesia is intended by him, where he writes manganese. Dismissing this for an inadvertency, we will therefore return to chrome. I have carefully repeated and somewhat varied and extended the experiments of Saugier on the discovery of chrome in meteoric stones. 1. A strong solution of caustic potash was boiled for an hour on a portion of the stone in powder, the fluid was filtered; it had a slightly yellowish colour. 2. Nitric acid was added, somewhat in excess, in order that the potash might all be saturated. 3. Nitrat of mercury, recently formed, without heat, was added, but there was no precipitate whatever; at this stage of the process, Saugier threw down a red, orange coloured precipitate, or chromate of mercury. 4. A small portion of the stone was now fused with pure potash, in a silver crucible, and maintained for some time in a red heat; every thing soluble was then taken up by water, the fluid was filtered, and had a green colour. 5. Nitric acid was added, a little in excess, and then nitrat of mercury, as before, but no precipitate ensued, these experiments were several times repeated, and with the same success. 6. Other portions of the fluid, resulting from the boiling of potash upon the stone, and from its fusion upon it, and subsequent solution, were now mixed with the nitrat of mercury, without the previous addition of nitric acid. A copious yellow precipitate was thrown down, this was heated to ignition in a platinum crucible, the oxid of mercury was decomposed, and its elements expelled, and a small portion of a green oxid remained in the crucible. In several repetitions of the process this, invariably, occurred. I had been led to suspect that this was the oxid of nickel, because the alkaline solution, from which it had been obtained, gave a black precipitate, with the hidro-sulphuret of ammonia; accordingly, on fusing a portion of this oxid, with borax, under the blow-pipe, it produced a glass of a hyacinth red; the same fact took place with a portion of a substance, known to be the oxid of nickel, which was fused with borax, for the sake of comparison. On fusing a portion of the chromat of lead, or Siberian red lead ore, with borax, and afterwards with vitreous phosphoric acid, glasses of an emerald green colour were produced. Hence it was concluded, that the meteoric stones of Weston do not contain chrome, but that the green oxid obtained, was the oxid of nickel. No. LII. Observations of the Comet which appeared in September 1807, in the Island of Cuba, by J. J. de Ferrer. The longitudes and latitudes of the preceding table, have been deduced from angular distances observed of Arcturus, Vega, Altair, a, B and in the Swan, with the circle of reflection, described in page 265 of this volume. The observations from the 1st Octr. till the 7th Novr. were made in the city of Havanna, the others at the plantation of Don Joseph de Cotilla, situated in latitude 22° 55′ 16′′ N. and 44",3, in time, E. of Havanna. The times of the observations were determined by a good chronometer, regulated by absolute and corresponding altitudes of the sun and stars, and the times observed at the plantation, are referred to the city of Havanna, by the difference of meridians. To determine the place of the comet, many series of observations were made with two or three of the above named stars, choosing those that made the most convenient triangles, and as the different observations could not be made at the same time, care has been taken, to refer all the distances observed, to the same instant, by means of the variation observed of the distances of the said stars from the comet. The distances observed were freed from the effects of refraction, corrected by reference to the state of the thermometer and barometer. The places of the stars were taken from the Connoisance de temps, of Paris, 1806; allowance being made for the proper motion, precession of the equinox, nutation and aberration. Further, the latitudes and longitudes of the said table are the apparent, that is, affected by the nutation and aberration. The elements of the orbit of the comet were calculated from the first observations which I made in Havanna, that is, from 1st Octr. to 7th Novr., by Don Francis Leamur, Lieutenant Col. of the Royal Corps of Engineers, and are the following: Passage through the perihelion, mean time at the city of Havanna, Septr. 18th 11h 58' 59', Longitude of the ascending node. Inclination of the orbit. Place of the perihelion. Perihelion distance, that of the sun being 1. 8$ 26° 39′ 09" After having concluded the observations, namely up to the 1st December, I determined to calculate the elements of the parabolic orbit, by the combination of all the observations, and the following elements are the results. Passage through the perihelion, mean time, at the city of Havanna, Septr. 18. at Greenwich, Longitude of the ascending node from the mean equinox=8$ 26° 42′ 12′′ Place of the perihelion. Perihelion distance, that of the sun being 1 63 12 51 .9 00 51 35 0,6462667. 12h 37′ 00′′ 18 06 40 Comparison of the observations with the results of the theory calculated by the above elements. The longitudes and latitudes observed and calculated in the following table, are freed from nutation and aberration. The two last columns shew the difference between the longitude and latitude, observed and calculated. 1807, Novr. 13 By 8 scries of O's double altitudes, observed near the meridian, with a circle of reflection. 22° 55′ 14" N. Mean Latitude. By astronomical observations, I have determined the bearing of the highest hill of Camoa, N. 13° 34' 10" W. The hill of Camoa, from the city of Havanna, according to the survey which was made by the order of Government, was determined 29250, Varas of Castilla 13,11 geographical miles, bearing S. 45° E. Latitude of Havanna, according to a great number of observations made with the same circular reflector. Hill of Camoa S. 45 E. 13',11 miles, difference of latitude Latitude of the hill of Camoa. By direct observations on the hill, with the circular. Mcan latitude of the hill. 23° 08′ 30′′ : 9. 16 22.59 14. 22 59 16 |