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Proceedings of Philosophical Societies.


June 6. On the Binomial Theorem, by John Walsh, Esq.

A paper, by Dr. Davy, was likewise read, entitled “'Some Observations on Corrosive Sublimate.” It is known that the liquor hydrargyri oxymuriatis of the London Pharmacopæia, on exposure to light, slowly undergoes decomposition ; and it has been asserted that light has a similar effect on corrosive sublimate itself. Dr. Davy relates a number of experiments made to investigate these points. He finds that corrosive sublimate remains unaltered on exposure to light; that it remains unaltered when exposed in solution in media, having a strong affinity for it, as alcohol, ether, muriatic acid, &c. and that decomposition takes place only under circumstances of complicated affinities, as in the instance of the liquor hydrargyri oxymuriatis, and in the aqueous solution, when calomel and muriatic acid appear to be formed, and oxygen evolved.

For the purpose of further illustration of the subject, Dr. Davy describes a series of experiments on corrosive sublimate with alcohol, ether, several oils, muriatic, and the mineral acids, many of the muriates, &c. the results of which hardly admit of being given in the form of abstract. In every instance that an oil, whether volatile or fixed, was heated with corrosive sublimate, mutual decomposition took place, charcoal was evolved, and muriatic acid and calomel formed. Besides, when oil of turpentine was used, some traces of artificial camphor appeared ; and when the oils of cloves and peppermint, a purple compound distilled over, consisting of the oil employed, and muciatic acid. With muriatic acid, common salt, and some other muriates, corrosive sublimate formed definite compounds remarkable for their solubility. : June 13.-On the State of Water and Aeriform Matter in the Cavities of certain Crystals, by Sir Humphry Davy, Bart. PRS. June 20. Some Experiments on the Changes which take Place in the fixed Principles of the Egg during Incubation, by W. Prout, MD. FRS.

The author, after a few preliminary remarks, proceeded to relate his experiments on the recent egg. The specific gravity of new laid eggs was found to vary from 1080 to 1090. Eggs, however, as is well known, on being kept for some time, become specifically lighter than water, owing to the substitution of air for a portion of their water which escapes. Thus it was stated that an egg exposed for two years to ordinary circumstances,

lost nearly two-thirds of its weight. Experiments were next related, the object of which was to attempt to ascertain the relative weights of the shell, albumen, and yolk. For this purpose the eggs were boiled hard in distilled water, and the different parts weighed in their moist state. The average of 10 experiments gave

for the shell 106.9, albumen 604.2, and york 288-9, on the supposition that each egg originally weighed 1000 grs. to which standard the weights of all the eggs were reduced. These experiments show that the relative weights of these different portions of the egg differ very considerably, particularly the shells, the weights of which were found to vary from 77.6 to 108, on the supposition that the original weights of the two eggs were equal. An egg, when boiled, and cooled in the air, always lost considerably in weight; and the water was found to contain traces of most of the saline contents of the egg

After these remarks on the recent egg, the author proceeded to relate the results of his analysis of the egg at the end of the first, second, and third week of incubation, and arrived at conclusions of which the following may be considered as an outline :

1. That an egg loses about one-sixth of its weight during incubation—a quantity amounting to eight times as much as it loses in the same time under ordinary circumstances.

2. That in the earlier stages of incubation, an interchange of principles apparently takes place between the yolk and a portion of the albumen ; that this interchange is confined on the part of the yolk to a portion of its oily matter, which is found mixed with a portion of the above-mentioned albumen. That this portion of albumen undergoes some remarkable changes, and is converted into a substance analogous in its appearance, as well as some of its properties, to the curd of milk; and, lastly, that a portion of the watery parts of the albumen is found mixed with the yolk, which becomes thus apparently increased in size.

3. That as incubation proceeds, the saline and watery matters again appear to quit the yolk, which is thus reduced to its original bulk, or even becomes less than natural; and that in the last week of the process, the greater portion of the phosphorus quits the yolk likewise, and is found chiefly in the animal, where it exists as phosphoric acid, and in union with lime, constituting, its bony skeleton, which lime amounting to about three grains,

does not pre-exist in the recent egg, but makes its appearance,

in some unaccountable manner, during the process.

The author then proceeded to make a few remarks on the source of the earthy matter, which, he observed, must be either derived from the shell, or from the transmutation of other principles. The great difference existing among the shells of different eggs rendered it impossible to determine by chemical means, and the application of averages, whether it was derived from the

New Series, vol. IV.


shell or not; but the extravascular position of the earthy matter of the shell, the separation of the membrana putamınis in the latter stages of incubation, and particularly the singular fact of the small quantity of earthy matter, originally existing in the egg, remaining unappropriated at the end of the process of incubation, rendered this opinion very improbable. The author, however, left this point to be determined by future observation.

GEOLOGICAL SOCIETY. April 19.—On the Formation of Vallies by Diluvial Excavation, as illustrated by the Vallies which intersect the Coast of Devon and Dorset. By the Rev. W. Buckland, F.R.S. F.L.S. V.P.G.S. and Prof. of Geology and Mineralogy, University, Oxford.

The author, on presenting the society with two sectional views of the coast on the east of Lyme, and on the east of Sidmouth, is led to consider the general causes to which vallies owe their origin, and particularly such as occur in horizontal and undisturbed strata within the limits of their escarpments.

Many vallies may be ascribed to the elevation or depression of the strata composing the adjacent hills, by forces acting at very remote periods from within the body of the earth itself; and to similar forces, principally we may refer the high inclinations and contortions of the strata that compose the most elevated mountains, and some also of the minor hills.

Other vallies have been occasioned by the strata having been originally deposited at irregular levels, and others to some partial slips or dislocations of portions of strata.

But at different periods of time, intermediate between the deposition of the most ancient and the most recent of the strata, the irregularities of level arising from the preceding causes, have been variously modified by the action of violent inundations, hollowing out portions of the surface, and removing the fragments to a distance. To such inundations, we must ascribe the water-worn pebbles of the red marl and of the plastic clay formations.

A cause similar to that last mentioned, has wrought extensive changes on the surface, however variously modified by preceding catastrophes, at a period subsequent to the deposition and consolidation of the most recent of the regular strata. For rocks of all ages bear on those portions of their surface which are not covered by more recent strata, the marks of aqueous excavation, and are strewed over with the mingled fragments of the most recent, as well as of the most ancient beds.

When one or more sides of a valley are formed by any of those abrupt escarpments, such as usually terminate the outgoings of our secondary strata, it is then difficult to say to what extent the discontinuity of the strata and the formation of the valley, beyond the limits of the escarpments are attributable to the last of the above recited causes; for we know not how far the strata originally extended beyond their present frontier, nor how much of the subjacent valley is referable to other causes than the most recent diluvian agency. But when a valley occurs within the limits of the escarpment of strata, which are horizontal, or nearly so, and which bear no marks of having been moved from their original position, by elevation, depression, or disturbance of any kind ; and when such valley is inclosed along its whole course by hills that afford an exact correspondence of opposite parts, it must be referred exclusively to the removal of the substance once filling it, and the cause of that removal appears to have been a violent and transient inundation. The author contends, that vallies, such as those last described, cannot have been formed in any conceivable duration of years, by the rivers now flowing through them, since each individual stream owes its existence to the prior existence of the valley through which it flows. But for further proofs and illustrations of the diluvian theory, he refers to the works of Catcott and Dr. Richardson, and of Mr. Greenough.

Of the same nature with those last described, are the vallies which form the principal subject of the present communication. Their main direction is from north to south, at right angles to the coast, and nearly in the direction of the dip of the strata in which they are excavated. The streams that flow through them are short and inconsiderable, and incompetent, even when flooded, to move any thing more weighty than mud and light sand.

The greater number of these vallies, and of the hills that bound them, are within the limits of the escarpment of the green sand formation, and in their continuation southwards cut down into oolite, lias, or red marl, according as this or that formation, constitutes the substratum over which the green sand originally extended.

There is usually an exact correspondence in the structure of the hills inclosing each valley, so that whatever stratum is found on one side, the same is discoverable on the other side, upon the prolongation of its plane. Whenever there is a want of correspondence in the strata on the opposite sides of a valley, this is referable to a change in the substrata, upon which the excavating waters had to exert their force. The section of the hills presents in general an insulated cap of chalk, or a bed of angular and unrolled chalk-flints, reposing on a broader bed of green sand; this, again, reposes on a still broader base of colite, lias, or red marl. With the exception of the very local depression of the chalk, and the subjacent strata on the west of the Axe at Beer Cliffs, the position of

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the strata is regular and slightly inclined, nor have any subterraneous disturbances operated to any important degree, to affect the form of the vallies.

The mass of chalk which at Beer Head composes the entire thickness of the cliff, gradually rises westwards, with a continual diminution of its upper surface, until after becoming more and more thin it finds in Dunscombe hill its western boundary: Beyond this boundary, on the top of all the highest table lands and insulated summits, from the ridges that encircle the vales of Sidmouth and Honiton, to the summits of Blackdown and even Haldon west of the Exe, angular chalk flints are found. Similar chalk Aints are found on the summits of green sand that encircle the vallies of Charmouth and Axminster; and large insulated masses of chalk itself are found along the coast from Lyme, nearly to Sidmouth, and in the interior at Wideworthy, Membury, Whitestanton, and Chard, at the distances of from 10 to 30 miles from the escarpment of the chalk. These facts concur to show, that there was a time when the chalk covered all those spaces on which the flints are now found, and that it probably formed a continuous stratum, from its present termination in Dorsetshire, to Haldon west of Exeter.

Similar observations are made by the author concerning the green sand, and similar inferences are drawn from them as to the former continuity and subsequent excavation of its strata.

May 3.-A Paper was read, entitled “ Additional Notices on the Fossil Genera Icthyosaurus and Plesiosaurus,” by the Rev. W. Conybeare, M.G.S.

This paper consists principally of anatomical details not susceptible of abridgment. It fills up the outline of the history of the fossil genera Icthyosaurus and Plesiosaurus, sketched in a preceding communication published in the 5th vol. Transactions Geological Society, and establishes five different species of Icthyosaurus, principally distinguished by the form of their teeth. A particular account of the dentition of this genus is given by the author, from which it appears that it resembles that of the crocodile in the general form of the teeth, and the general mode in which the secondary teeth replace the first set; but differs in the circumstance, that the latter teeth become in advanced age, completely solid, by the ossification of the pulpy matter filling the interior cavity, which in the crocodile always remains hollow, a constant developement of successive series of new teeth taking place in the latter animal. In this point the dentition of the Icthyosaurus agrees with the other

genera of the Saurian order, to which the term lacertian may most strictly be applied.

The comparative analogies of structure exhibited by the Icthyosaurus to both these branches of the Saurian order, are examined and illustrated in detail in the present communica

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