ducing and arranging them. He therefore took the rough observations with him, and availed himself of an interval of leisure to arrange them in the same form as his other catalogues. The stars observed are less in number than those of his former catalogues, but they are in some respects more interesting, from the greater number of delicate and difficult objects comprised; the measures of which, with those in Struve's great work on Double Stars (said to be in course of publication), it will be important to compare. The catalogue contains 105 new double stars, as well as the observations of several others that were previously known; the positions and distances of which, as observed by Sir J. Herschel, are here recorded: some of the stars, however, inserted in Struve's catalogue, he has been unable to find in this review of the heavens.

Sir J. Herschel states, that he has nearly gone over the whole south circumpolar region, to 60° from the pole; the observations of which are in the course of arrangement. He is somewhat surprised at the extraordinary paucity of close double stars, which cannot arise from want of power in the telescope, or from the nature of the climate: for he considers his mirrors as perfect as it is possible to make them; and he represents the beauty and tranquillity of the climate to be such, that the stars are reduced to all but mathematical points, and thus allow of their being viewed like objects under a microscope. But although the number of double stars is so small, considering the richness of the southern heavens in stars, yet he represents the nebule as very copious; and has accordingly collected a numerous list, which will doubtless, in due time, be laid before the public.

II. A Letter from the Superintendent of the Nautical Almanac to the Secretary, of which the following is a copy:

"Nautical Almanac Office, Dec. 6, 1835. "MY DEAR SIR,—I have the pleasure of forwarding, for distribution, some copies of an Ephemeris of Halley's Comet, founded on the revised elements of the orbit, which appear, as far as I have yet tested them, to represent the observations very well; so well, indeed, that I shall not hesitate to adopt them as the basis of my future proceedings with the cometary calculations.

"An accurate Ephemeris for the period of the Comet's apparition is now absolutely necessary, to enable observers to identify the stars with which the Comet has been compared, to determine parallax, and, finally, to settle their observations. It may, therefore, be as well to apprise you, that such an Ephemeris, founded upon the revised elements, and embracing the period between Aug. 1, 1835, and March 31, 1836, is now in progress, and will be published next week.*

"It is my intention afterwards to determine, for the same period, the effects produced upon the right ascension and declination by a minute variation of each of the elements of the orbit; and, finally, to compute the effects of the disturbing forces of the old planets. These tables will be prepared and published with all possible dispatch. We

This Ephemeris has since been completed and printed.-SFc.

shall thus have an accurate representation of the Comet's track, derived from good approximate elements, and corrected for perturbations; together with the most ample means of rectifying the orbit, as soon as astronomers shall be prepared with their reduced observations. "There are many observers who are either unaccustomed to, or have a distaste for, the labour of reducing observations; and very few persons, I apprehend, who will undertake the task of resolving the final equations of condition. I therefore take this opportunity of inviting observers to transmit their observations to me, with a full statement of all particulars necessary to an accurate estimate of their value; and of making known my intention, as soon as the observations can be collected, to get out the best orbit that they are capable of yielding.

"Yours, very truly,

"A. DE MORGAN, Esq., Sec. Royal Ast. Soc."

"W. S. STRAtford."

III. Extract of a Letter from Captain Smyth to the President, containing the translation of a notice from M. Cacciatore:

"One important thing I must communicate to you. In the month of May I was observing the stars that have proper motion; a labour that has employed me several years. Near the 17th star, 12th hour, of Piazzi's Catalogue, I saw another, also of the 7-8th magnitude, and noted the approximate distance between them. The weather not having permitted me to observe on the two following nights, it was not till the third night that I saw it again, when it had advanced a good deal, having gone further to the eastward and towards the equator. But clouds obliged me to trust to the following night. Then, up to the end of May, the weather was horrible; it seemed in Palermo as if winter had returned: heavy rains and impetuous winds succeeded each other, so as to leave no opportunity of attempting anything. When at last the weather permitted observations at the end of a fortnight, the star was already in the evening twilight, and all my attempts to recover it were fruitless: stars of that magnitude being no longer visible. Meanwhile the estimated movement, in three days, was 10" in R, and about a minute, or rather less, towards the north. So slow a motion would make me suspect the situation to be beyond Uranus. I was exceedingly grieved at not being able to follow up so important an examination.'

İV. Report on the new Standard Scale of this Society, drawn up at the request of the Council, by Mr. Baily.

The commencement only of this Report, which is very long, was read; the remainder of it being deferred till the next meeting of the Society. An abstract of the whole will be given in our next Number.

V. Observations of Moon-culminating Stars, made at the Observatories of Greenwich, Edinburgh, and Cambridge, during the month of November, 1835.

Third Series. Vol. 9. No. 54. Oct. 1836.

2 M

"

ZOOLOGICAL SOCIETY.

(Feb. 23, continued.)—A paper by Mr. Owen was read, entitled, Descriptions of some new or rare Cephalopoda, collected by Mr. George Bennett, Corr. Memb. Z.S." The subjects referred to in it included specimens of Cranchia scabra, Leach; a small nondescript Loligo; the head and principal viscera of a Decapodous Dibranchiate Cephalopod from Port Jackson; a small nondescript species of Octopus; and a very small specimen of Argonauta hians, with its Cephalopodous inhabitant (Ocythoe Cranchii, Leach), and a large cluster of ova: all of which were exhibited, in illustration of the communication, by permission of the Curators of the Museum of the Royal College of Surgeons, of which collection they now form part.

The specimen of Cranchia scabra was taken by Mr. George Bennett in a towing net in lat. 12° 15′ S., long. 10° 15′ W.; and was at first regarded by him as a species of Medusa: and Mr. Owen observes, that from the uncommon form which this very remarkable Cephalopod presents, one cannot feel surprised that it should have been, at the first view, referred by its captor to a Radiate family, with which the Cephalopods bear, in more than one respect, an analogical relation.

As the type of its genus Mr. Owen considers the Cranch. scabra with reference to the generic characters that separate Cranchia from the neighbouring groups: from Loligo and Onychoteuthis it is distinguished by the continuity of its mantle with the dorsal parietes of the head; and from Sepioteuthis, Sepiola, and Rossia by the proportions and position of its fins. The form of the fins alone is evidently insufficient in Cephalopods for generic distinctions, as will appear from considering the variations in this respect that occur in the several species of the well-marked genus Onychoteuthis, Licht.; and also in the several species of Loligo as at present restricted, some of which, especially Lol. brevis, Blainv., make so close an approximation to Cranch. scabra in the rounded contour, as well as the terminal position, of their fins, that were it not that the exterior margin of the mantle is in all of them free on its dorsal aspect, the latter Cephalopod, notwithstanding its singular form, could not be separated generically from the Loligines on external characters alone. As in the figures published by Férussac of the Cephalopods named Cranch. cardioptera by Péron and Cranch. minima by himself, the anterior margin of the mantle appears to be free on its dorsal aspect, similarly to that of the true Loligines, it must be doubted whether these species are correctly referred to the genus Cranchia: and the same doubt may perhaps be extended to Cranch. Bonelliana, Fér., in the description of which no mention is made of the adhesion or otherwise of the mantle to the posterior part of the head. This adhesion Mr. Owen regards as an essential character of the genus.

The specimen of Cranchia scabra on which the genus was founded by Dr. Leach, having been imperfect in some of its parts, Mr. Owen carefully describes the species anew from the perfect individual ob

acid and then dried, without suffering any alteration in its colour. But if boiled with this water, it yields protonitrate of mercury, and becomes quite white. If a solution of protonitrate of mercury be poured upon this white precipitate and left at rest on it at ordinary temperatures for several hours or longer, the precipitate gradually becomes as blue as it was at first; and after some days the intensity of this colour increases, if the nitrate of mercury remains in excess: if the precipitate be heated with the latter it remains white, but after the evaporation of the water of the nitrate of mercury, it becomes blue, and if the heat be increased, orange red.

When the blue and orange red precipitate is strongly heated on a piece of platinum foil, it detonates, giving out sparks and smoke, and flying on all sides like sky-rockets, with a hissing noise. It is dissolved in heated muriatic acid, with the formation of nitric acid and hydrocyanic acid, and forms a colourless solution which is not rendered turbid by alcohol nor precipitated by muriate of ammonia.

The white precipitate kindles when heated on platinum foil without detonating, burns away without flame, and leaves behind about 38 per cent. of spongy platinum, strongly disposed to ignition. Boiling muriatic acid dissolves it, but without development of nitric or hydrocyanic acid, and forms an almost colourless solution, which a solution of potash turns yellow, and which, on evaporation to dryness, gives a residue, appearing partly red, partly yellow, and partly blue, and this by a strong heat is decomposed into hydrocyanic acid, chloride of mercury, and cyanuret of platinum.

The solution of the alkalies and alkaline earths decompose the coloured and the bleached precipitates, and separate, from the first, protoxide and peroxide of mercury, from the latter, only peroxide; at the same time they leave their radical in combination with the cyanogen of the cyanuret of mercury, and in this combination form, with the cyanuret of platinum, easily crystallizable double cyanurets of platinum. When the white precipitate is gradually heated to redness in a glass retort, it is decomposed into cyanogen gas, fluid mercury, and cyanuret of platinum. The quantity of the latter is about 48 per cent. (4-8 grains from 10 grains on which I experimented); we may therefore consider the white precipitate as a combination of

= Pt Cy+ Hy Cy, or Pt Hy Cy2,

48 Cyanuret of Platinum 52 Cyanuret of Mercury and we may consider the blue (and red) precipitate as a combination of this double cyanuret with protonitrate of mercury. I have not yet examined in what relation these salts stand to one another, and whether the blue colour belongs to the whole combination or merely to one of its products (perhaps the oxide of platinum).

The cyanuret of platinum which remains after the pyro-chemical decomposition of the colourless cyanuret of platinum and mercury, is a fine olive-yellow pulverulent substance, insoluble in water, acids, or alkalies, combustible, and when burnt in the air leaving 78 to 79 per cent. of pure platinum, and when heated with oxide of copper in the pyro-pneumatic apparatus giving carbonic acid and nitrogen gases nearly in the proportion of 2 to 1; it therefore consists of one atom Pt Cy. of platinum and one of cyanogen

1

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the trunk: their superior contour is an obtuse angle; their inferior margin is rounded.

In the Cephalopod described as Cranchia cardioptera, Pér., to which the species under consideration has a superficial resemblance, the terminal fins have a semicircular contour, and their origins are widely separated anteriorly; they also extend beyond the termination of the trunk: the trunk, moreover, is broader in proportion to the head, and does not diminish gradually to a point, but is rounded off at the posterior extremity. The Cranchia minima of Férussac may be at once distinguished from Lol. laticeps by the extension of the trunk beyond the small rounded fins, which gives a trilobate contour to the termination of the body.

In internal organization Lol. laticeps agrees with the other Loligines whose anatomical structure has been ascertained.

The fragments of the Decapodous Cephalopod obtained at Port Jackson are too imperfect to allow of their being satisfactorily referred generically: they may, however, have belonged to a species of Loligo or of Sepioteuthis. As in some species of both these genera, the outer lip was characterized by eight short processes, on the inner surface of which, at the extremity of each, were three or four small suckers, attached by peduncles, and having precisely the same structure as those of the eight large exterior arms. In this repetition of the structure of the external series of cephalic processes there is an evident analogy to the different series of labial processes of Nautilus. In some species, as for instance Lol. Pealii, Le Sueur, the acetabuliferous labial processes are more developed than in Mr. George Bennett's specimen. In Lol. corolliflora, Til., they have been compared by Bojanus to the internal shorter series of tentacles of a Medusa; affording another evidence of the analogy, though remote, between the Cephalopods and the Radiata.

The two lateral processes at the termination of the rectum being, in this instance, evidently adapted to form a valve for the closure of the anus, Mr. Owen was induced to examine the corresponding structure in other species; and to conclude, from his examination, that similar appendages, although varying in form and position, perform the same office in other Decapoda. The slenderness of the anal processes in Onychoteuthis and Loligopsis being such as to preclude the possibility of their acting as mechanical guards, it is inferred that they may perform the function of instruments of sensation, and convey the stimulus to contract to the muscular parts that close the outlet of the alimentary canal. In the Octopoda the anus is not similarly provided; and, indeed, it may be generally remarked that valvular or other guards are developed among the Cephalopoda only in such as have the power of propelling themselves forwards in the water.

The generative apparatus forming part of the fragments referred to, Mr. Owen examined it with some care. His most important observation relative to these organs relates to a small round flat fleshy body, attached near the anterior aperture of each of the two nidamental glands, destitute of any outlet, and of an orange colour.