nected are strongly characterised and well defined-or those derived from the names of places, where the beds are fully displayed and have been sufficiently examined:-as in the case of the Portland limestone, the Purbeck beds, and the Hastings sands. I am upon the whole disposed to prefer denominations of the last mentioned description, since the very terms them selves point to the types in which the characters of the strata are best exhibited; and if the place which furnishes the name be easy of access, geologists will find no difficulty in recurring to the standard, for the purpose of verification, in doubtful cases. From these combined considerations, I should propose to distinguish all the strata which form the subject of my last communication by different names; and, for the present, not to group them together. And as the firestone beds are well displayed at Merstham, near Reigate, a place within a few hours journey from London, while the cliffs at Shanklin and its vicinity, in the Isle of Wight, exhibit very distinctly almost every form of what has been called greensand,-in a district which must always be interesting to geologists,-I would suggest the adoption of the following series of names, with the hope of preventing ambiguity in future : Proposed names of the strata. 1. Chalk Synonymes. Including chalk with and without flints(the craie blanche of the French) and grey chalk-chalk marl of Mr. Webster. 2. Merstham beds. Firestone.-Greensand of Mr. Webster, Isle 3. Gault. of Wight.-Tuffeau.-Craie-chloritée or Glauconie-crayeuse of the French.* Folkstone-mari.—Blue marl of Mr. Webster in the Isle of Wight.-Golt-brick-earth of Smith's county maps.-Tetsworth-clay?; 4. Shanklin sands. Greensand-commonly so called.-Upper part of the ferruginous sands of Mr. Webster.-Glauconie crayeuse ? 5. Weald clay... (By some considered as the same with the clay of Tetsworth, which, however, is probably the gault?) ́ [ *T 6. Hastings sands. Iron sands.-Lower part of the ferrugi nous sands of Mr. Webster, I. of Wight, The presence 1 of chert is mentioned by Mr. Brongniart as characteristic of the craie-tufau: but the relations of the Glauconie-crayeuse are rendered doubtful by what the same author has mentioned of its separation in some cases from the Tufau by a bed of bluish clay marl. (See Ann. des Mines, i. 254-5, 257-8, and vi. 550, 547 ; or the translations in Mr. De la Beche's" Selections," &c. 1824.) ARTICLE XII. (To the Editors of the Annals of Philosophy.) GENTLEMEN, FEELING extremely anxious that my reply to Dr. Fitton should be inserted in the Annals of this month, I am sorry to find that your previous arrangements have rendered that impossible. Since several geologists are concerned in the question, and may write upon the subject, I trust that my reply will find a place in the next number, and that your readers will suspend their judgment until they read my paper, which is connected only with that by Dr. Fitton already published in your last. I am, Gentlemen, yours, &c. T. WEBSTER. ARTICLE XIII. Answer to Mr. Phillips's Observations on the London Pharmacopaia. By Mr. G. Whipple. (To the Editors of the Annals of Philosophy.) GENTLEMEN, London, Aug. 11, 1824. IN reply to a few of the hints given in the Annals of Philosophy for June, by way of improvement on the formulæ constituting the New London Pharmacopoeia (1824), I should esteem it an obligation, if favoured with a translation of the first nineteen lines of the paper, the parvum in multo. On the formula for the preparation of sulphate of potash, the writer of the paper is most fatally mistaken. In my opinion, the College have acted most judiciously in directing that the excess of acid be saturated with potash, instead of lime, for, in this instance, they employ a salt of a very inferior value to obtain one of a greater, (and, by the bye, of some considerable importance to every manufacturing chemist), and, therefore, contrary to the opinion of the writer (of that paper), who says, "The College would have acted economically in imitating the directions of the Edinburgh Pharmacopoeia, by saturating the excess of acid of the bisulphate, with lime instead of potash; by this the waste would have been avoided of using a salt of greater value to obtain one of less." A single importunity to any of the drug warehouses will convince him of his error. Moreover, I would ask, since economy be the maximum on which he has founded his examination, whether this salt could not be more economically obtained by employing potash in the process for forming the ferrum præcipitatum. To attempt a definition of his remark on the preparations of iron, would be Aquam arare, wherefore 1 shall be obliged, if favoured with information, as to its abstract tendency. What must be the inference of an assertion like the following? “That in the preparations of iron, there have been some alterations which are to be considered as amendments; but I am apprehen) sive that the good which has been done is more than counterba lanced by the omission of improvements, or the commission of errors." Surely, if in the formula, that is, such as have been altered, amendments have taken place, how can we ascribe to the College a want of ability, or the commission of error? My remark relative to the ferri subcarbonas, will be seen in the note on sulphate of potash. The acidum aceticum fortius diluted with water does not answer for the purpose of making the liquor plumbi subacetatis...! I have frequently tried it, and ever been unsuccessful, for ash soon as it assumes the density, as required in the Pharmacopoeia, it becomes opaque, which cannot be removed by filtration. Anticipating the insertion of this paper in the Annals of Philosophy, by the which an elucidation of the several paradoxes complained of may be obtained,* I remain very respectfully, Gentlemen, G. WHIPPL ED ARTICLE XIV. Proceedings of Philosophical Societies. ROYAL SOCIETY. THIS Society re-assembled on the 18th of November; when Douglas C. Clavering, Esq. Capt. R. N. was admitted Fellow, and fi the Croonian Lecture, by Sir E. Home, VPRS. was read it related to Mr. Bauer's discovery of nerves on both the foetal and maternal surface of the Placenta: a paper, by the same authorb as also read, On the Changes undergone by the Ovum of the 2 wFrog, during the production of the Tadpole. We shall give some account of these papers in the next number of the Annals. LINNEAN SOCIETY. The first meeting of this Society for the present session took to place on Nov. 2; when W. J. Broderip, Esq. was admitted * I shall probably take some notice of this communication in the next Number.R. P. ra vd kompido yllesimonosa Fellow, and a paper was read, On three Species of Birds, one hitherto undescribed, and the others new to the Ornithology of the British Islands. by N. A. Vigors, Jun., Esq. FLS. We shall present a report of this paper in our next. i domchi diw ha vola, alt GEOLOGICAL SOCIETY, und teună Nov. 5.-A paper was read entitled "Observations on aw Comparison between the Beds below the Chalk in the Isle of Wight, and in the Counties of Surrey, Kent, and Sussex; by Thomas Webster, Esq. Sec. G. S. Mr. Webster stated, that in a late visit to the Isle of Wight, he had been so fortunate as to discover a rock of the same {} nature as the calciferous sandstone of Hastings, a circumstance that has furnished him with a fixed point, by means of which he t had been enabled to compare the beds in the Isle of Wight with those of the south-east part of England more correctly than had been done before; and he presented a table of what he considered as the equivalent beds in these two places. He imagined that these equivalents had been hitherto stated erroneously by several geologists and he attributed this chiefly to the following causes 1st, The imperfect state of the science of geognosy which had not as yet established fixed principles of classifica tion: 2dly, The want of acknowledged types of beds or formations, to which all other parts might be referred: 3dly, The difficulties attending actual examinations, arising from the deficiencies or want of continuity of some beds, and the variation in the composition and structure of others; difficulties which had, in his opinion, been underrated. W The author then proceeded to point out in detail what he conceived to be the history of some of the errors that had been fallen into. Thus, until lately, the descriptions given by various geologists of the rock called green sand were supposed to be applied to one bed only, whereas, in fact, there are two beds dis tinct from each other, the undercliff of the Isle of Wight, and f the rock of Folkstone, each of which had received this denomi-i nation, baAlso in the groups which it had been found necessary lot to form, they had not agreed with each other as to the indivi-t dual beds enclosed in one group. Thus, some had formed a groups (which they called the ferruginous sand) of the sands v above and below the weald clay; while others had attached the name of ferruginous sand to those below the weald clay only. He had also reason to fear, that an error had been committed in not identifying the beds which are called the ferruginous sand,}' on the west of the chalk, as the Carstone, Wobourn sand, and l as the ol the Faringdon bed, with the beds in the wealds of Kent and Sussex to which the name of green sand had been given.site 1* -redmu.jan att si dvinas auk New Series, VOL. VIII. 2 H to The following is the table of equivalent beds above alluded to : Nov. 19. A paper was read, "On the Purbeck and Portland Beds;" by T. Webster, Esq. Sec. G. S. The author observed, that the great general features of the geology of the Isle of Purbeck had been already traced but by him in his letters to Sir Henry Englefield. He now confined himself to some details respecting the series of limestone beds in the Isle of Purbeck, and to those in the Isle of Portland. i He then proceeded to give a description of the strata from which the well known Purbeck stone used in London, for side pavements, &c. is derived. This stone is composed almost entirely of fragments of shells. The Purbeck marble contains chiefly univalves in a compact limestone, and these in general are smaller than the univalves in the Petworth marble, both having been supposed to belong to freshwater shells; but the author possessing specimens that contain a mixture of marine with freshwater shells, he cannot consider this as a decided freshwater formation, a term that, in his opinion, ought to be restricted to those beds supposed to have been formed in takes only. The common Purbeck stone appears to consist of fragments of small bivalves, of which the ongin is doubtful. Mr. Webster then gave a detailed account of the quarries in the Isle of Portland, which furnish the Portland stone much |