from Kamschatka south-east, perhaps more southerly than to 50° latitude; and On the Chinese Chronology and Astronomy. By the Rev. Mr. G. Costard. The affectation of some nations, in carrying up their histories to so immoderate a height, plainly show those accounts to be fictitious and without founda-. tion. This was the case of the Babylonian and Egyptian accounts; and probably it will be found to be the same with any other people that make the like pretensions. The only people in later times that have been thought to contradict this opinion, are the Chinese, of whose history the world has been taught to entertain very extraordinary conceptions. But that even they will be no exception to this surmise, but on the contrary a strong confirmation of it, will, Mr. C. thinks, appear from what he now offers.. Mr. C. then enters on a desultory discourse to show the improbability of the very remote æras of the Chinese historians, as well as of skill in their astronomers, to make any just and accurate calculations of the celestial motions; notwithstanding what has been said by the Jesuit missionaries on those heads. From what has been here offered, Mr. C. thinks, it is pretty evident, that how ingenious soever the Chinese may be in works of art, their talents do not 1 coat. The first sort may be considered as of the pebble kind; and they are said to be found near the beds of rivers, after great rains; the others are found in mines, and in the clefts of rocks. The gems of the first sort were what the ancients most usually engraved on: these are commonly called intaglios; and they are mostly of a long oval figure, inclining to a point at each end, convex as well on the engraved face as on the others, with a ridge running froin end to end on the outer side, which is thus as it were divided into two faces; both which are also, though not so distinctly, parted from the upper face, by another ridge running quite round the oval. The stone most commonly found engraved is the beryl; the next is the plasm or prime emerald; and then the hyacinth or jacinth. The chrysolite is sometimes, but rarely, found engraved; as are also, but that very seldom, the crystal, or oriental pebble, the garnet, and the amethyst. Of the beryl there are three species; the red, inclining to orange-colour, transparent and lively; the yellow, of an ochre-colour; and the white, commonly called the chalcedon, of the colour of sheer milk. These last two have less life than the first. The plasm or prime emerald is green, nearly of the colour of stagnated water; sometimes tolerably clear, but for the most part full of black and white specks, and rather opaque.—The jacinth is of a deep tawny red, like very old Port wine, but lively and transparent.-The chrysolite is of a light green grass colour, and is supposed to have been the beryl of the ancients, transparent, but not lively.— The crystal, or oriental pebble, is harder and more lively than the common rock crystal; is of a silverish hue, and but very little inferior to the white sapphire.— The garnet is of the same colour as the jacinth, but more inclining to the purple,. and not so lively. The amethyst is of a deep purple, transparent and lively. There were some other species of stones engraved on by the Romans; but rarely before the latter times of the empire, when the art itself was greatly on the decline. All the beforementioned sorts of stones are said to have been of the produce of Egypt, or of the East Indies; and to have been brought from the borders of the Nile, or of the Ganges. Here follows a general table of what are usually called precious stones. The beryl is red, yellow, or white.-The plasm is green.-The jacinth of a deep tawny red.—The chrysolite of a light grass green.-The crystal, or oriental pebble, of a silverish white.—The garnet of a deep red claret-colour.-The amethyst, purple. The diamond, white.-The ruby, red or crimson-coloured.The emerald, of a deep green.—The aqua marina, of a bluish sea-green, like sea-water.—The topaz, of a ripe citron yellow.-The sapphire, of a deep skyblue, or of a silver white.-The cornelian, red or white.-The opal, white and changeable.-The vermillion-stone, is more tawny than the jacinth. All these stones are more or less transparent; the following are all opaque: The cat's-eye, brown.-The red jasper, called also thick cornelian, is of the colour of red ochre.-The jet, black.-Agates, are of various sorts.-The bloodstone, is green, veined or spotted with red and white.-The onyx, consists of different parallel strata, mostly white and black.-The sardonyx, of several shades of brown and white.-The agat onyx, of two or more strata of white, either opaque or transparent.-Alabaster, different strata of white and yellow, like the agate-onyx, but all opaque.-The toad's-eye, black.—The turquoise, of a yellowish blue inclining to green.-Lapis lazuli, is of a fine deep blue. Of most of the species beforementioned there are some of an inferior class and beauty. These are commonly called by jewellers occidental stones; they are mostly the produce of Europe, and found in mines or stone quarries; and are so named, in opposition to those of a higher class, which are always accounted oriental, and supposed to be only produced in the more eastern parts of our continent. The onyx, sardonyx, agate-onyx, alabaster of two colours or strata, as also certain shells of different coats, were frequently engraved by the ancients in relief; and these sorts of engravings are commonly called cameos. They also sometimes ingrafted a head, or some other figure in relief of gold, on a blood-stone. Besides which, there are some antiques, mostly cornelians, that are covered with a stratum of white. This stratum has by some been considered as natural, but it was really a sort of coat of enamel that was laid on. This was used only in the times of the lower empire. The stones esteemed the best for engraving on, were the onyx and sardonyx; and next to them the beryl and the jacinth. The ancients engraved most of their stones, except the onyx and the sardonyx, just as they were found: their natural polish excelling all that can be done by art; but the beauty of the several species of onyxes could only be discovered by cutting. The merit both of intaglios and cameos depends on their condition, on the goodness of the workmanship, and on the beauty of their polish. The antique gems of Greek work are the most esteemed, and next to them the Roman ones, in the times of the higher empire. A New Method for a Mural Astronomical Quadrant, free from many inconveniencies to which former ones are subject. By Christian Lewis Gersten, F.R.S. N° 483, p. 507. From the Latin. The great usefulness of arches, firmly fixed to walls in the plane of the meridian, is well known to all who are the least conversant with astronomical observations. Hence it is that few observatories can be accounted well furnished without one. Yet it is commonly found that there is no wall so solid and firm, and no bond of iron or other metal so strong, as to keep this instrument perfectly true with respect to the earth's axis. Mr. G. has therefore devised this new contrivance for a mural arch, furnished with a telescope and micrometer, to be constructed so as to answer the following purposes, viz. 1. That at any time it may appear if the plane of the instrument be vertical. 2. Whether a perpendicular passes exactly through the centre of the quadrant and the beginning of the divisions on the limb. 3. To correct the aberration of the plane of the quadrant from the vertical line, without altering the position of the beginning of the divisions on the limb, with respect to the perpendicular. 4. And again, to correct the aberration of the beginning of those divisions, from the perpendicular, without changing the proper position of the plane of the quadrant with respect to the vertical line. 5. In like manner, to correct the deviation of the plane of the quadrant from the plane of the meridian, without altering the perpendicular situation of the plane of the quadrant, and of the beginning of the divisions. 6. That it may be quite free from the variation in the expansion of the metals by heat and cold. 7. That the instrument may easily be rectified, viz. that it may easily appear whether the line passing from the object, through the intersection of the threads in the tube to the eye, be exactly parallel to the line passing through the centre of the quadrant and the division shown by the rule; and to set it easily right when there is occasion; a division otherwise very laborious and difficult. To obtain all these requisites, Mr. G. then gives a very long and minute description of the several parts and contrivances of this instrument, with a vast multitude of references to a great number of plates and figures; in which it is not now profitable to follow him, as we apprehend we are possessed of better mural quadrants in this country, the description of which will hereafter occur. The whole quadrant itself is recommended to be of solid metal, by which means, Mr. G. says, when it expands or contracts by heat or cold, it will always remain similar to itself; and the free expansion or contraction will not be hindered by its suspension. Two Observations relating to Morbid Anatomy. By Albert Haller, Professor of Physic at Gottingen, and F. R. S. N° 483, p. 527. An Abstract from the Latin. In the first of these observations it is stated that in a woman 40 years of age, the vena cava, between the origin of the left renal vein and the iliac veins, was discovered to be contracted in so great a degree as scarcely to allow the blood to pass through it. A portion of coagulated polypose blood was found within its contracted cavity. On the other hand, the right spermatic vein was dilated to such an extent, as to supply the place of the vena cava, transmitting the blood, diverted from its natural channel, to the vein of the ureter (ureteris venæ) which in the sound state is a small vein, and arises from the right iliac. A similar instance of a constriction or obliteration of the cavity of the vena cava is recorded in Johan. Rhodii Mantiss. Anat. Obs. xxi. From both cases it is evident, that an obstruction may occur in the larger blood-vessels; and that when, by reason of such obstruction, the blood is diverted from its natural channel, it rushes with impetus into the smaller canals, which consequently become dilated. The second observation relates to the appearances noticed in the dissection of a woman, who was reputed to be 100 years old. The muscles, glands, nerves, and cellular membrane, were found to be very compact and hard. There was a very great enlargement of the aorta at its origin from the heart. 1. The arterious valves of the heart were partly indurated, partly interspersed with stony concretions (petrosis tumoribus) much the same as in one of Cowper's figures (Myolog. Reform. tab. xi). The other valves were nearly in a sound state. 2. The inner coat of the aorta, not only at its origin from the heart and in the thorax, but in the abdomen also, had the appearance of being ulcerated, and was beset with a number of loose squamæ, which were either of an osseous or of a stony compactness; and heaps of small tophaceous concretions blocked up the mouths of most of the vessels which branched off from the aorta. 3. In like manner a number of osseous crusta were found on the internal coat of the hypogastric and iliac arteries, and of the arteries which go to the pelvis, &c. And in all the arteries of the body were found hard coagulated portions of blood of a round figure, but of a smaller diameter than their containing canals.. 4. The gall-bladder was full of bile, scarcely bitter, and moreover contained 20 small angular calculi, by one of which the mouth of the ductus cysticus was completely obstructed. Professor H. remarks that he had generally found the bile to have a sweet taste, when concretions were formed in it. Concerning the Property of Water Efts* in slipping off their Skins as Serpents do. By Mr. David Erskine Baker. N° 483, p. 529. This animal is to be found in the spring, and during the whole summer season, in most ditches and shallow standing waters throughout England, being unknown to very few. It has long been known, that most of the serpent kind put off, or, as we commonly term it, cast their skins, at certain periodical times; though we are very little acquainted with the manner of their performing this work, since it is * The species of newt here intended is the lacerta aquatica of Linnæus, or common water-newt. + Son of Mr. Henry Baker before noticed. Vol. 8, p. 426. |