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bones that present themselves in various parts of the globe, I should be very happy if some of your learned naturalists would take this subject into consideration.

1785, July.

M. M. M.

XXV. Fossils in the Vicinity of Oxford.

MR. URBAN,

Oxford, March 22, 1757.

IN your two last Magazines you have obliged your readers with some entertaining remarks upon fossils. Of late years greater attention has been given to that branch of natural history than formerly, as is evident from the valuable collections in the cabinets of the curious. Were these collections not made for amusement only, but also for the better investigation of the hidden cause of the dissolution of the earth, when it received these adventitious bodies into its bosom, we might entertain some hopes of coming at the true solution of that difficult problem, than which, perhaps, there is none in all natural history more intricate, though the effects of that dissolution are every where obvious.

It is true that extraneous fossils are found more abundantly in some places than others; but there is not a tract of land in the whole world entirely without them; and they are found at all depths, indifferently, so far as the miners have hitherto had occasion to follow them.

Hordel-Cliff is very productive of extraneous fossils, and affords great variety of them, as your ingenious correspondent observes: they are also more wonderfully preserved in that stratum of clay, than in any other part of this kingdom, being very little changed from their original state, and ap pear equally elegant with recent shells of the same tribes, saving the colour and polish, which are somewhat impaired. But I think we can boast of as great variety, (though in a very different state) at a small village called Stonesfield, near Woodstock, in this county. Most of these are entombed in slate stone, have a more striking aspect, and shew apparent tokens of far more remote antiquity, though I believe them to be of the same date with those at Hordel-Cliff.

In splitting this stone, the workmen find great variety of extraneous bodies, such as sharks teeth, which the naturalists call Lamiodontes; there are also found Lycodontes, or wolves teeth; Conichthyodontes, or tusks of sea animals;

Icthyperia, or palates of fishes; all of which cramp names with their icons, may be seen in Hill's Nat. Hist. Vol. I. There are also found at the same place, (but in different strata) Echini Ovarii, Cordati, Clypiati, &c. variety of Anomic Chama; oysters in abundance, of a crooked form, which has given them the name of the sickle oyster: belemnites, nautilites, jaws of fishes with the teeth perfect in them; bones of quadrupeds, ribs, vertebræ, &c. some of birds; the medullary cavities being larger than the others, they are more frequently compressed, I suppose, by the general subsidence of matter at the deluge. American ferns are also found in this slate-stone, with other vegetables. The plant on one side, and the impression on the other, has a pretty effect, and is a sure proof that the matter which formed the stone was once in a fluid state. It would take up more room than you have to spare, to enumerate all the varieties that are found in this slate-stone, and the strata above it.

About three months since, there was found in the same stratum, the thigh-bone of some large animal; it is twentyseven inches long, and by computation, (for it is bedded in stone) about 16 or 18 inches in circumference. One half of the bone is clear, and one end entirely detached from the stone, and perfect; so that it may be looked upon as a capital fossil, and a great rarity. I suppose it to be the thigh bone of the Hippopotamus, or sea-horse, though I have but little judgment in osteology.

I formerly met with two pieces of bone, and some vertebræ of the same kind, and of a proportionable bulk, at the same place, which are now in the collection of a gentleman in London.

All the way from the abovementioned village to Oxford, which is ten miles, the different strata abound with plenty of fossils and this famous seat of learning is surrounded with still greater variety, and, if possible, more curious; so that one would imagine providence had placed it in the midst of these natural rarities, to exercise and divert the minds of the curious, after their close attention to things of greater importance.

This city has on the north side, large beds of gravel, of singular use in making those beautiful walks and gardens in and about it, which are kept in very great order by the University. In this gravel are found porpites, fungites, astroites, and such like coralloid bodies. Pectines, anomiæ, ostracites, &c. are also found in it.

Near the east gate of this city, and in St. Clement's adjoining, the gravel beds are lost, and we find a stratum of

blue clay, which produces oysters of a different kind from those found in gravel, being remarkable for the convexity of their shells. Along with these oysters are found belemnita, ammonitæ, very small, and saturated with pyritical matter, which gives them a kind of shining-like armature.

On the south side of St. Clement's, the gravel appears again, and abounds with much the same fossils as those on the north side of Oxford. Hard by, in Cowley-Common, are found gryphitæ, or the crooked-bill oyster, of a very large size, and very thick, broader in the margin than those usually called by that name. They are remarkable for shewing the several laminæ or stages of their growth, being at first no bigger than a vetch, and proceeding to the size of six inches diameter. Either the world was less populous, or the use of oysters less known in the antediluvian times, than now; for we never find any recent shells arrived to that growth.*

Bullington Green, Headington Heath, Shotover quarries, and the stone-pits at Garsington, all adjacent, are equally replete with great variety of very curious fossils, such as pectines, great and small, echini, belemnitæ, pholades, coralloides, shrimps, claws and other parts of crabs; pinna marinæ, oysters remarkably large and flat, (found recently in Virginia;) naufilita, cochlitæ in abundance; a remarkable small serated tree-oyster, auriculares, vertebræ, jaws and teeth of animals, ammonitæ of various kinds, some turbins, strombi, and great plenty of mycetites, astroites, &c.

To close the whole, in our Museum we have the collections of Plot and Lhuyd, which contain great variety both of native and extraneous fossils, which now appear to great advantage, being lately reduced under their proper classes by their present keeper, a gentleman in every respect qualified for the work.

I am, yours, &c.

1757, March.

A. B.

* Some Rock-oysters are perhaps an exception to this observation.

XXVI. On the Coluber of Virgil.

Qualis ubi in lucem coluber, mala gramina pastus.
VIRG. En. ii. 471.

MR. URBAN,

BY Coluber is here meant not the common snake, but the viper, as is evident from the poet's supposing him to be replete with poison, acquired by feeding upon noxious herbs, whereas the snake is entirely destitute of poison. The venom, in his opinion, was gotten by the serpent's living upon deleterious plants, which is a great mistake, for the viper is carnivorous. However, in the Georgics, lib. iii. 425. et seq. he shews, that he was well aware that the chersydros of Calabria, a poisonous species of serpents, lived upon animal food, such as fish and frogs.

It has been thought, till of late, that the viper had a fascinating power, whereby it charmed its prey into its mouth, being neither quick in its motion, nor having any feet to assist it in the management of any animal that could struggle with it for its life. And it is certain, that this opinion receives great countenance from two papers in the Philosophical Transactions, Vol. xxxi. one by Paul Dudley, and the other by Sir Conrad Sprengell. But the truth is now found to be, as appears by a later narrative from North America, and inserted likewise in the Transactions, that the rattle-snake, which is a species of the viper, gets his prey in this manner. He first bites the animal, and at the same instant the poison pressed out of a bag at the roots of his fangs, runs, through an aperture in the fangs, into the wound; after this he keeps his eye upon the creature, and waits for the operation of the instilled poison; and when it has brought on the death of the animal, he then begins to lick it, and prepare it for deglutition. This is the provision which the all-wise providence has contrived for the subsistence of a serpent, destined to live upon animal food, but incapable otherwise of contending with a creature of any vivacity or strength. But then I would ask, what is it that the common snake lives upon, and how does he get his living? He has many of the properties of the adder or viper, but wants his poison; for I presume it is generally agreed, that the snake is harmless. He is slow, he coils himself, he casts his skin, he sleeps in winter, and is as unable to cope with a

living animal as the viper is. It is said, indeed, that frogs and other creatures have been found in his belly; but the truth of this is what I am desirous of knowing, and as this is the season for their making their appearance after the sleep of the winter, I shall be obliged to any curious naturalist, that will open a few of them this spring, and look into their stomachs, to inform us what he finds there, for at present I can hardly think, if he feeds upon animal food at all, that it can be any thing more than worms and insects; for since he is not armed with poison, it is very difficult to conceive how he can master and manage any larger animal, though his gullet, I suppose, is as capable of distention for the swallowing either of a mouse or small bird, as is the viper's.

1757, March.

Yours, &c.

PAUL GEMSege.

XXVII. On the Phenomenon of Dew.

THE dispute concerning the origin of dew seems as yet to be left undetermined. Some philosophers have insisted that it falls from the middle region of the air, others as strenuously assert that it rises from the bowels of the earth in va pour, which never reaches the middle region of the air, but falls back condensed into water, after having risen a comparatively small distance above the earth's surface.

The former of these allege, in favour of their opinion, "that it is most natural; that we see the rain, which is of the same nature with dew, descending from the superior regions; and consequently ought not to suppose that the dew has any other origin, since it differs no otherwise from small rain, or misling, than in degree. That the atmosphere is continually replete with a vast quantity of vapours; and that, when the solar heat is withdrawn, the cold which occupies the superior regions immediately condenses and precipitates them, if not dissipated by the wind, in form of dew; and that those bubbles or vesicules, though imperceptible to us while separate, easily gather into larger drops (when they fall) by their own attraction; and are, in that state, found on grass, and on the herbs of the field and garden, in the morning, where they remain till they are again exhaled by the sun."

Those of the contrary party say, "That exhalations are continually flying off from the earth; being raised either by

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