^-*^i 1*^ '"x-M m m 1, 1 1 S v.^ 1 i m^ m ^^xirr-:" iPk ^^Wf^^^:mM ki^S^ I. Stbftavid^^'ftoo^no^.A^^m'aM (^iiaifia/ ,;^iaynH/n^ ^^. Ma^ia/i^ . M.HAUY. ltiJ)lj..h.-d Ik 4IVJo,-A,J,tmiAry,ji.tSti<. THE PHILOSOPHICAL MAGAZINE: COMPREHENDING THE VARIOUS BRANCHES OF SCIENCE, THE LIBERAL AND FINE ARTS, GEOLOGY, AGRICULTURE, MANUFACTURES AND COMMERCE. BY ALEXANDER TILLOCH, M.R.I.A. F.S.A. Edin. anp Perth, &c. ** Ncc arancarum sane textus ideo melior quia ex se fila gignunt, ncc nostcr vilior quia ex alicnis libamus ut apes," Just. Lips. Monit, Polit, lib. i. cap. i. VOL. XXXV. Tor JANUARY, FEBRUARY, MARCH, APRIL, Mi and JUNE, 1810. --"^ ^^ ^ - ,^- ^^ [ i*\ LONDON: FEINTED BY RICHARD TAYLOR AND CO., SHOE LANE: And sold by Richardsons; Cadell and Da vies; Longman, Hurst, Rees, and Orme , Vernor, Hood, and Sharpe; Murray; Higuley; Sherwood and Co.; Harding; London; Constable and Co. Edinburgh: Brash and Reid, and Niven, Glasgow: ii GiLBKRT & H0JDG£S,Dublua. C O N^ T E N T S OP THE THIRTY-FirTH VOLUME. On the Means of counteracting the Effects produced ly the Formation of the Gases found in Coal Mines . . 3 On Expectorated Matter, Abridged from the Philosophical Transactions for \mo • •• •• ^^ Memoir on the lest Method of decomposing the Chromate of Iron, obtaining Oxide of Chrome, preparing Chromic Acid, and on some Combinations of the latter ... 20 Observations on loaded and unloaded Barges, Boats, Beams, or Jlodti?ig Bodies descending with Streams or Currents, and why the heavier End will go foremost . , , . 31 On Nwvi Materni 35 Memoir on the Mineralogical Geography of the Environs of Paris . , , , 36 Account of an extensive Organic Lesion of the Brain, tho- racic and abdominal Viscera, unaccompanied ly the Symptoms usually observed in similar Affections 59 On Dr, Pearson's Proposal for an Institzitionfor obtain* ing an equal Temperature in Houses 62 Description of a new Cupping Instrument , , . , 81 On that Power of the Eye, ly which it is adjusted to see Objects distijictly at different Distances .. .• 82 On a native Arseniate of Lead ,, &7 Description of a reflective Goniometer , 94 Chemical Analysis of a Black Sand, from the river Dee, in Aberdeenshire , . , gS Analysis of the Gray Copper Ore of Airthrey, in Stirling- shire , 105 Vol, 35. No. 146. June \B\0. a Hints CONTENTS. Hints on the Suhject of Jnima^ Secretions . . . . 108 Geohrrfral Rf marks avd Queries o?i Messrs. Cuvier and Brogniart's Memoir on the Mineral Gcograp'ty of the t'viro7fs (f Paris i 13 Report on (7 ne'r Vavigable Canal proposed to he rut from Okeham to Stamford^ and frnrn thence to the Town of Bosnm 140 OnCri/sta/logniphy. By M,Uavy. Translated from the . laU Paris Edition o//:/s TraitedeMineralogie, 14 5, 187, 261, 342, 452 On a hard Artificial Stone that generates a considerable Quantity of Uei- during its Consolidation ; with the Ap' plication (f this Fact to the Cause of Volcanic Fires 153 On Injuries of the Brain I6l On Sal^^on- Leaps .. i63 On Platina and Native Palladium from Brasil . . . 164 On an Improvement in the Manner of dividing astronomical Instruments ....... ... 168 On M, Bemetzrieder'vS erroneoiis Calculations of the Magnitudes of certain musical Intervals .. .. 175 On the Culture of Parsnips, and their Utility in feeding Cattle 176 Analysis of the Carbonated Chalybeate IVell, lately disco- vered at Middleton Hail, the Seat of Sir William Pax- ton, Kt.y near Llanarthney in Carmarthenshire 179 On the Preparation of a FibroTis Substance from Bean Stalks, applicable to the Uses for uhich Hemp is employed 18Q On the Identity of Columl'ium and Tantalum . . . . 201 Description of a Method oj ft ting up in a portable Form the Electric Column lately invented by J. A. De Luc, Esq. Also an Account of several Experiments made ivith it 205 On the comparative Influence of Male and Female Parents on their Offspring .... . . . . 210 On the Fossil Bones of Horses and Wild Boars . . 215 J^xtracl CONTENTS. ' Extrart from a Me7noir by M. Mathieu, on the Dhctrverf of several Blocks of Orbicular Granite recently found in Corsica • • . . 2:23 On the Torpidity of Animals ., 241 Description of a Hydro -pnenmatic Table for collecting and tranif'crr27ig Gases, and for experimenting on permanently elastic Fluids 24/ On Salmon Fry : in Answer to a Correspondent .. 251 On the supposed Fresh-wafer Origin of the Gypsum Strata in the Environs of Paris ; on the Geological Characters and lielations of the Alum Shales on the Northern Coasts if Yorkshire: and on the Orbicular Blocks of Sienite on Mount- Sorrel Hill, in Leicestershire • • , , 256 On a Method (f examining the Divisions of astronomical Inst'^ummts 277 On Azimuthal Refraction .. 287 Second Findication of Dr, HerscheVs Theory of Colowe^ Rings, in Answer to aT anonymous Reviewer , : 289 Report made t<) the French Institute on a Memoir uf • . Dklaroche on the Air -bladder of Fishes ... 29.1 Description of an improved Apparatus for t lie Deco^r^posl- tion of Potash and Soda .. , 321 On the Composition and Decomposition of Forces, Trans'- lated from " Traite elementaire dc Statiqut*, par Gas- pardMonge.. .. .. 323 Pescriplion of the French Telegraphs used on the Coasts of Flanders, &^c. with Observations on ilie same, and a Plan of a Polygrammalic Telegraph on a new Construction 339 Account of the Uliynn Dykes in the Neigh hour hood of the Giant's Causeway, Bally castle, and BelfiSt ., 364 The Bakerian Lecture for 1809. On some new Electro-che- mical Researches on various Objects, particularly the me- lallic BodteSffrom the Alkalies, and Earths, and on some Combinations of Hydrogen ,, •• ,, ,, . 401 Obsei'vor CONTENTS. Ohservatwns respecting a New Scale for the Thermmne- ter 415 On the Properties of Furze or Whins 427 jiddiiional Observatiojisfor the Purpose of as certain ivg the Value of growing Timber at different and distant Periods of Time 428 A List of about Five Hundred Collieries in and near to Der- byshire 431 The Croonian Lecture , 439 Comparative Tables of the Beats of the Tempered Conso- nances in M, Kirnberger^s and the Isotonic or Equal Temperament Systems of Tuning ; uith Remarks on the common System used by Organ Tuners, compared ivith thai of M, Kirnberger 448 Notices Inspecting New Books . . . , 66, 302, 382, 467 Proceedings of Learned Societies 74, 154, 225, 303, 383,460 Intelligence and Miscellanegjis Articles 76, 157, 232, 317, 399, 468 List of New Patents . . 79> 158, 237, 319, 399, 470 Meteorological Tables •, ..80, 160, 240, 320, 400, 473 THE THE PHILOSOPHICAL MAGAZINE. I. On the Means of counteracting the Effects produced hy the Formation of the Gases found In Coal Mines. To Mr. Tilloch. Sir, 1 AM induced to request you to lay the following pages before the public, from a desire to put a subject of much importance in a train for investigation. Little has hitherto been written on the subject, calculated to do away the frequency of the dreadful accidents to which miners are incident ; and what has been written has come from the pens of those who were not every way qualified to do justice to what they have taken in hand. As the manner of working mines varies according to cir- cumstances, many things herein will ajjpear to some as redundant, while to others much will seem to be omitted. But let it be remembered that I lay no claim to general knowledge: what will be advanced is chiefly the result of practical observation in a particular district. To men of considerable experience in mining, probably, nothing will be found worthy of attention : but if a few in- dividuals should chance to reap any benefit, or should it prove the. means of preventing one single accident, my t;nd will, in no small degree, be obtained. With regard to the experimental part, it may be proper to observe, that my Situation renders it in many instarices impossible to pro- cure apparatus of the best kinds; and hence, if any inac curacies should chance to be discovered by the scientific reader, it is hoped ample allowances will be made. In endeavouring to accomplish the important and de- sirable object before us, we ought to adopt those measures which have a tendency to prevent the accumulation of the Vol, 35. No. 141. Jaw. 1810. A 2 noxious 4 On preveni'ing AceideiH^ noxious gases ; for wherever they are suffered to accumu- late, there is continual danger*. I do not know of any vehicle, neither do I think it pos- sihle to devise one, at all comparable to that with wnich Nature has wisely provided us, namely^ atmospheric air. This offers itself so abundantly, and requires such simple arrangements to convey and apply it to the purpose, that we raav be considered as extremely deficient in our duty, if we do not make the best use of it, before weturnoqr attention to matters of speculation. Tn fact, no contrivances can supply its place. A salubrious atmosphere is so necessary to the healthy action of the human system, that in mines where a due proportion of its vital principle in a given space is soiTietimes wanting, it is the cause of numbers lingering out a life of diseasef. Every remedy which tends materially to increase the ex- pense of working a mine, or which throws considerable obstacles in the way oi getting and convey'mg the minerals out of the mine, cannot on these accounts in the present day be adopted. Of this kind we may reckon the schemes for neutralizing or destroying the gases by chemical agency; such, for instance, as the one of oxy-murialic acid for destroy ing^re- Jaw//, proposed by Dr. Trotter J. The ex- pense attending such a process would be enormous, the mode of practice unmanageable, and thcrenaedy, if it could be successfully employed, would be worse than the disease. The quantity of hydrogen gas^orjire-damp, evolved during one day in a mine subject to it, is almost incredible to persons unacquainted with the fact ; and as we cannot rea- sonably expect to procure chemical reagents at a much cheaper rate than this gas may be obtained artificially, the idea of applying them to this purpose must therefore be entirely abandoned. There are also other modes which might be adopted, such as procuring light accompanied by a heat below the temperature requisite to fire the inflammable gas; or by • This requires no proof, because accidents can never happen but where there is an accumulation of gas. The idea of preventing their formation is too ridiculous to deserve the least notice. f Working in mines, vrhere Jtre-damp is very prevalent, is the occasion of violent headachs, and sometimes of sore eyes. Choke-damp is considered .as producing asthmas, headachs^ &c. \ '* A Proposal for destroying the Fire- and Choke-damps of Coal Mines, &c., &c., on the Principles of modern Chemistry, by T. Trotter." N:w~ castle. form in from Flre-danip in Mines i 6 forminsj an insulated atmosphere round the flame of a lamp or a candle; admitting the air of the mine thereto in such proportion, and so diluted with the insulated and incom- bustible air, as to prevent explosion. This last plan has often been proposed ; and I under- stand that a gentleman of Sunderland has completed a contrivance of this kind. Although these modes of ob- taining the end in view are in a great measure free from the difficulties inseparable from reagents, yet there are others which render them also objectionable. With regard to the first method, the only one with which I am acquainted is the steel mill as it is called, which consists of a number of flints, so placed with respect to a circular steel pulley or wheel, to which a handle is fixed, that, when it is turned, a considerable quantity of light is given out. The manual labour attendant on this plan, to- gether with the expense of renewing the apparatus, (to say nothing of the imperfect light procured,) renders it inappli- cable to ordinary purposes. Indeed I believe it is seldom or ever used_, except in peculiar situations, when a part of the mine is incapable of v^entilation, without great expense or difliculty. Moreover, it cannot be considered as entirely free from danger of exploding the gas; and that this has actually happened, I am well informed. Reflectors are sometimes used to convey light, in thril" ling (or thurling) between two shafts of no great depth, or for other works of a like nature, where the quantity of fire- damp is considerable, and incapable of being carried off with facility. Concerning lamps constructed so as to burn in an insu- lated atmosphere, nothing deduced from practice can be said. They must necessarily be expensive, and extremely liable to be broken by pieces of coal, &:c., flying from the workmen, or from accidental falls; and should this happen in a part of the mine where the gas was accumulated in a quantity suflBcient to render the use of such a lamp neces- sary, what would be the consequence? Besides, compli- cated machinery is ill calculated for ignorant and careless miners: an instrument of this, nature must needs require nice adjustment and frequent trimming, which last could not be done with perfect safety where any danger was to be apprehended. In short, men who have ever been accus- tomed to the use of a candle, and a piece of clay as the ready means. of fixing it where circumstances require, will not willingly be incumbered with a lamp, even of a com- mon construction. There is another serious objection to A3 be 6 On preventing Accidents be urged against all the foregoing modes of obtaining light, naiiiely, the pre- supposed want of a siifUcicnt quantity of oxygen in the atmosphere; this, addetl to the positive had qualities of the gases present in such situations, would greatly endanger ihc health and lives of the workmen. Let us now turn our attention to the more practicable iknd effectual plan of ventilation ; and in pursuing this sub- ject we will commence with the first opening of a colliery. It should be understood, that hydrogen and carbonic acid gaiionE; the invariable advanie in men's wages, as some compensation lor the great dangers to which thty are exposed, may all be placed to this account, superior 10 On preventing Accidents superior strata takes place, and the waste fills up, it is well, as then no damp vviil accumulate, and thereby en- danger the lives of the neighbouring workmen. Too much caution cannot be observed, by men who are working near such old hollows, never to introduce their candles into any cavities which may happen to be pene- trated, hut immediately extinguish tiicm and retire, until proper means can be adopted to ensure safety. What ac- cidents have occurred for want of this simple precaution*! It may be, and in fact is, at times necessary, owing to increase of temperature or levity in the atmosphere, to ob- tain a greater supi)ly of air than is wanted in the ordinary course of things, or, more properly speaking, to preserve an imilbrni circulation. Here we have an admirable contrivance, whose powers are unlimited ; and this consists in rarefying the column of air in the ascending shaft by means of a fire. There ap- pears to be a difference of opinion as to the best mode of acconiplij^hing this. Some build a chimney or cupola upon or near to the shaft, making the top thereof so close that the air must pass up the chimney, at the bottom of which a fire is placed : others hang, by means of a chain, &c., a circular grate filled with burning fuel, down the shaft; and some fix a grate in the bottom of the shaft, in a heading, driven a few yards for the purpose; while others cut a groove in the shaft side, which, when built up it\ front, forms a chimney. If we are to judge of the comparative merit of the fore- going plans from their respective powers of rarefaction, we must give to the last method but one a decided prefe- rence. By it we are enabled to produce the greatest diffe- rence in weight between the two columns of air, on which ventilation solely depends ; and if the grate be placed a tolerable height, and opposite to the current of air passing into the shaft, we shall obtain the quickest draught for the fire. The chimney not only greatly increases the effects of the fire, but is a sort of guard to the ropes, which might be damaged by coming too near the naked fire. 1 shall conclude this imperfect sketch, with offering a few general remarks, which, to those who put them in practice, will not be found useless. In all cases where danger from fire-damp is to be ap- prehended, the miners should never work naked. It is not * This is a very common trick of miners, owing to an idle curiosity; and but too many have paid dearly for their temerity aud want of considera- tion. SO from Fire- damp in Mines. 1 1 so much the depth of the burn as the extent of it, which proves fatal : a covering of thin flannel would be found almost invariably to conline the injury to the face and ex- tremities. Some miners cannot aflbrd to do this, and others u'ill not, considering clothing as an incumbrance; but where men's lives and the interest of the proprietors are so much at stake, it ought to become a matter of com- pulsion. Should it so happen, that through some unforeseen ac- cident an explosion takes place, the persons in immediate danger ought to throw themselves down, covering them- selves as well as the spur of the occasion will permit, and then with all speed make their nearest way to that part of the mine from whence the air proceeds, taking care to creep as low as possible : by this means, suffocation from the azote, which remains after combustion, will be avoid- ed. Should any one be so unfortunate as to fall thus for want of respirable air, or by the choke-damp, every exer- tion ought to be made to cause the air to circulate through the place, so as to enable the sufferer to be brought out ; and when this is effected, resuscitating means should be immediately employed. Instances often occur, of men being stifled by the azotic gas, who were little or none the worse from the effects of the explosion. In every instance, where a miner penetrates any new or neglected cavity whatever, the precautions before men- tioned ought to be strictly observed, whether the mine be much subject to Jire-damp or not. The practice of laying scaffolds over or in a shaft, in. ©rder to do some necessary repairs, without being cautious to ventilate the underside, should be carefully avoided ; ter- rible explosions have been known to follow this negligent practice. These and other similar remarks, which will occur to every one conversant with mining business, if properly modified, would form a code of rules, with which every miner should be acquainted. December 19, 1809. *** We shall at all times be glad to recei^fe papers of the above description from practical men, on the subject of their pursuits, and shall think little of our trouble m rounding a period, or correcting grammatical inaccuracies, for such as may chance to need this assistance, owing to the devotion of their time to other important objects,— Editor. II. On t 12 ] II. On Expectorated Matter, By George Pearson, M.D., F.R.S, Abridged from the Philosophical Tratis- actions for I8O9. *^ J. HE attentioin of physiologists has been very much withdrawn, for the last half century, frotn the consideration of the different states of the circulating and secreted fluids^ in consequence of the opinion that the nervous and fibrous or muscular systems can afford satisfactory interpretations oi the phaenomena of living beings ; and on account of the disgust produced by the visionary properties and groundless hypotheses, originating in the humoural doctrines of Galen. But late experiments have manifested, that various things taken into the stomach can be made at pleasure to produce considerable effects, by impregnating sensibly the blood and urine, as well as the milk, sweat, and perhaps saliva. Further, the tine experiments of Professor Colman have shown, that the contagious glanders may be excited in the ass by the transfusion of the blood of a glandered horse^ and the matter from the nose of the glandered ass can produce this disease in the horse or the ass*. Hence I ap- prehend it is reasonable to expect, that the further investi- gation of the properties of the animal fluids will afford gratifying instruction to the researcher in natural science, and important practical information to the physician. " On the present occasion, I desire the honour of com- mutiicating the knowledge I may have acquired, by inves- tigating the properties of expectorated matter secreted by the bronchial membrane. 'Jlie appearances of this sub- stance serve to regulate the judgement of the physician con- cerning several diseases of the Tungs ; but especially of that of pulmonary tubercles, which yearly destroys 120,000 to 140,000 subjects of the United Kingdom* It is fit that I remark, that I do not notice in this paper the ingenious experiments of several learned chemists, because by so doing I should be led into a detail of too great extent for my design. '' The numerous varieties of expectorated matter, ac- cording to my observation, may be arranged and characte- rized under the following seven heads : '^ I. The jelly-like semi-transparent kind of ablucish hue,- excreted in the healthy state. • Mr. Colman alleges, that there is not a sufficient quantity of blood, in a single glandered ass, to excite the glanders by the transtusiou of blood into the liorse. ^' II. The On Expectorated Matter » 13 *' II. The thin mucilage-like transparent matter, so copiously expectorated in bronchial catarrhs. " III. The thick opaque straw-coloured, or white and very tenacious matter, coughed up in a great variety of bronchial and pulmonary affections ; especially in that of tubercles. '* IV. Puriform matter secreted without anv division of continuity, or breach of surface of the bronchial membrane, very Gommonly occurring in pulmonary consumptions. ^' V. The matter which consists of opaque viscid masses, together with transprjrent fluid ; or the second sort above etated. wiih nodules of the third or fourth kind. '' VI. Pus from the vomicae of tubercles. " Vil. Pus from vomicae by simple inflammation of the lungs, and without tub;rrcles. " Other kinds of matter are occasionally coughed up, such as calculi — masses of self- coagulated lymph — serous fluid — blood itself — and perhaps the vascular substance of the lungs ; but I do not write on these matters, because they either do not belong to any particular recognized dis- ease ; or they are rare occurrences in some well known disease, and are too obvious to require description, *^ § I. Sensible or obvious Properties, " 1. The jelly-like matter, as already said, is excreted in the best health, as well as sometimes in disease. It is mostly coughed, or hawked up, in a morning soon after a night's repose, during which it seems to accumulate. A few masses, or nodules, then appear of the consistence of jelly, and of the size of a pea to a hazle nut. It is also at any time liable to be excreted, in consequence of various extraneous matters irritating the fauces, to the amount of a few nodules. It is of a grayish colour or inclining to blue, with black specks; audit is rarely whitish in no- dules. The consistence is that of jelly, but of much greater tenacity. It has a barely perceivable taste of common salt, or muriate of soda. It commonly floats on water, but by agitation to disengage air bubbles, it sinks. It has no smell. To the naked eye, or assisted by a single magni- fier, this matter seldom appears uniform, but consists of a mixture of opaque and transparent masses of irregular fi- gures. With the compound microscope, spherical parti- cles were perceived, though few in number, when duly diluted, 'fhe presence of an alkali I could in no instance perceive, by nicuiis of the usual test^, namely, turmeric paper. 14 On Expectorated Matter, paper, litmus paper slightly reddened by vinegar, and cloth siaiued wiih violet juice ; nor was an acid denoted by means ct' litmus paper, except when I had reason to believe it was derived from various acid substances taken with the food, or drink, adhering to the inside of the mouth and fauces. " 2. 7'he mucilugp-tike expectorated matter^ according to rny observation, occurs much less frequently than the other sorts. Tt appears suddenly in great abundance in certain bronchial catarrhs. I have seen it to the amount of two or three pints in twenty-four hours. It is also secreted, but less copiously, in paroxysms of spasmodic asthma, and of ihc hooping-cough ; and but rarely in pneumonic or pleu- ritic inflammations, and in some chronical organic diseases of the heart and lungs. *' This matter is a transparent uniform fluid of the con- sistence of white of egg; or of a mucilage compounded of about- one part of arabic gum, and four or five parts of water. It is colourless — has a fleshy smell — has a brackish taste. After .standing eight or ten hours, a depoJiit takes place of ftbrous, leaf-like, or curdy masses, some of which are seen suspended in the clear fluid. In some cases no* dules of opaque thick ropy matter, at certain times, ac» company this mucilage-like matter. Under the simple magnifier I perceived irregular figured masses partly in motion and partly suspended. With the microscope, globules were seen ; but larger considerably than those of the blood, and iimch less numerous. With the usual tests there were no "indications of alkali nor of acid, provided the matter was un- mixed with other things. It usually floated, or was suspend- ed in water, when first expectorated ; but on standing in the water it fell to the bottom, evidently owing to the disen- gagement of air-bubbles. *•' By standing exposed to the air in warm weather, it sooner grew foetid ihan pus of abscesses ; without becom- ing opaque. Neither could I render it opaque or thicker, by exposure to a stream of oxvgen gas for an hour ; or by exposure of it in ajar of this gas for a month. "3. The opaque ropy matter above mentioned. ** 1st. It is secreted most copiously in that very common, and extensively epidemial disease of our climate, Xhtwinter- cough, occasioned by tubercles, to the amount of half a pint to a pint in twenty-four hours; especially during the winter season for several successive years, and sometimes during the whole of a long life, after the age of forty or fifty years. 2dly. It is oTien the expectorated matter of the On Expectorated Matter, l5 the pulmonary consumption of young persons, also oc* casioned by tubercles, but frequently mistaken for the pus of abscesses or vomicae. 3dly. It appears, oftentimes, in pneumonic or bronchial inflammation with fever, seemingly bemg a beneficial discharge ; as well as in some instances at the close of a fever without concomitant inflammation of the lungs. 4thly. A severe paroxysm of spasmodic asthma is often terminated in the excretion of this kind of jiiatter. 5thly. A secreted substance of this sort is some- times expectorated in various chronical organic diseases of the lungs, the heart, aorla, and parts contiguous to the lungs, which occasion difficult transmission of blood through them. " In ail these instances the matter by expectoration is of the consistence of thick cream, or of thin toasted cheese; so tou2,h as to hang in the form of \ rope, four or five inches m length, on pouring it from one vessel into an- other. Its aggregation is such that it is readily detached in large masses from the vitreous surface of vessels. It is not unusual for small black, or reddish spots, and streaks, to appear on the surface of this sort of expectorated substance, A pretty large bulk of it is seldom throughout uniform; but it is frothy, and exhibits opaque masses of various hues with transparent matter interposed. The colour is yellow- ish, straw-coloured, and white, or gray : it also, though seldom, is greenish and blueish. The taste asserted by pa- tients, is, in their own terms, various, namely, saltish, na?ty, faintish, sweetish, luscious, or like that of a sweet oyster, — a sharp or sour taste is the most rare. The only smell which I have perceived is that of flesh, but very fre- quently there is none. When any offensive or pungent smell was perceived, immediately after expectoration, I have always found that it was owing either to the foulness of the vessel in which it was received ; or it was from ex- traneous matters in the mouth, and from decayed teeth. *' This opaque viscid substance, being duly diluted with distilled water, was examined with microscopes of common- as well as of very great powers : by means of any of them crowds of spherical particles were seen passing to and fro, in currents, not unlike those of the blood -, except that they were larger. These globules I could not destroy, nor alter in form, by trituration; nor by long boiling in water; nor by exsiccation, and again dissolving in water; nor even by coagulation with mineral and vegetable acids, with alcohol, with sulphuric ether, or with tannin, and alum ; nor by mixture with caustic alkalies in a proportion which leaves the liquor 16 On Expec I orated Matter, liquor turbid ; nor for some time after the putrefactive pro- cess had appeared. But these globules disappear with such a proportion of sulphuric acid as detaches charcoal ; or of ni- tric acid, and of liquid potash, as produce a clear solution r altio by charring by fire. It is perhaps superfluous to re- mark, that these atomic globules are quite different from the air bubbles usually entangled in this kind of matter, as perceived by the microscope ; the latter differ much from the former, in being of far greater magnitude — in being less numerous — in being transparent, and disappearing on agi- tation, or heating the matter, or even by mere standing. '' For the most part this expectorated substance swims on water; but by agitation or stirring to disengao;e air bubbles, or by merely standing, it sinks. Some of the lumps suddenly hawked up, immediately fall to the bottom of a vessel of water. No signs of either acid, or alkali, appeared on the trials of this matter with well known re- agents, provided it was free from extraneous matter; but it was apt to betray acidity from things taken with the food or drink. " 4. Puriform matter, 1 have seen this matter expec-. torated in several diseases in the quantity of two or three ounces to half a pint in twenty-four hours, on some rare occasions, vvithout any breach of surface. I believe it would be considered by every one to be pus^ having the properties commonly admitted to be those of this sub- stance. It will, however, perhaps, only be just to call it pur'ijhrm, for the present, as it appears to me probable, that I shall hereafter be able to show that it possesses pro- perties not belonging to pus of abscesses, although in the obvious, or sensible properties, it is similar to such pus. Accordingly this expectorated matter is not only opaque, white, or yellowish, and thick as the richest cream, but it also has not more tenacity than cream. It is not apt to entangle air, and therefore it immediately mingles with water, rendering it milkv ; and presently subsides to the bottom, leaving the water clear, or at least whey-coloured. It appears to the naked eye uniform in its texture ; and nearly so under the simple lens : but under the microscope thou- sands of globules similar to those of the blood are seen, which are indestructible as those above related belonging to another kind of expectorated matter. *< The substance, of which I am now speaking, is most frequently excreted in the latter stages of pulmonary phthi- sis, for many weeks successively. It is taken for granted that this matter is from a breach of surface or ulceration > but On Expectorated Matter, 1 7 but on examination after death, snch a state was not found, in many instances, under my observation, although the lungs were as usual full of tubercles and vomicse. This puriform matter is occasionally expectorated in certain other diseases. The last summer my colleague, Dr. Ncvinson, furnished me with several ounces of this sort of substance, but of a greenish hue, and of the consistence of thin cream ; which was expectorated by a woman in the third week from the attack of the measles. In a few days she died. On examination of the lungs very carefully, by the excel- lent house surgeon of St. George's hospital, Mr. Dawes, no ulceration could be discovered in the trachea or in the bronchial tubes ; nor were any tubercles or abscesses found in the lungs. The patient, according to my information, had expectorated more than a pint of this fluid every twenty- four hours for a week before death. In another hospital case, a man laboured under a cough with spitting of mat- ter, which all who saw it called pus, and as usual it wa3 considered to arise from an ulceration, or suppurated tu- bercles; but, on examination after death, the disease was. ascertained to be condensation of the lungs, to the con- sistence of liver, with water in the cavities of the chest, and nothing more. ''5. Opaque viscid matter of a third, an d^ perhaps fourth sort, above distinguished, appearing in nodules, and irre- gular figured masses, mixed with transparent slimy matter of the second sort. '*• It is not unusual to see the mixture of these two different kinds, from severe fits of coughing in that constant epidemy of the British islands, the winter chronical pneumonia. " Different parts of the bronchial membrane being in different states, may account for the secretion of the two different matters. This seems more probable than that thes» different matters should be secreted from the same part; although it is true that the same part does secrete at one period transparent thin slime, and at another an opaque thick matter. The former is occasioned by great irritation of the membrane, and the latter is the effect of a more gradual secretion with much less irritation. " For the sake of brevity, I avoid a further description. The practical application of these observations, however important, would not be suitable in this place. '* The sixth and seventh kinds of expectorated substances being secreted after a quite different manner, and being very different in their nature from the preceding five kinds, I shall not give an account of thera in this paper/' Vol. 35. No. 141. Jan, 1810. B [Th« 18 On Expectorated Matter, [The author then 'describes at large, and with much pre- cision, the effects produced on expectorated matter bv the agency oF caloric; oF alcohol of wine, oF water; and oF- acetous acid — also some experiments with different objects from any of these: but we confine the remaining part of the present extract to his. Conclusions, as containing that kind oF information which will l^e most acceptable to the generality oF our readers.] '' Conclusions, ^' 1. From the preceding experiments and observations, and From others which I might have related, it does not appear that the various kinds ot expectorated matter, page 12, differ in the ingredients oF their composition^ but merely in the proportion of them to one another. " 2. It has been shown that expectorated matter consists oF coagulable, or, as it is also now frequently termed, albu^ minous animal substance^ and oF water impregnated- with several saline and earthy bodies; — that the largest proportion of the animal substance, which may justly be called an oxide, amounts to one-twelFth, and in some very rare cases to one-tenth of the expectorated matter, reduced to a brittle stale by evaporation ; and that the smalles* proportion of this oxide, in rare instances, amounts to one forty-fifth of the expectorated matter; but that the usual proportions of it vary between one-twentieth and one-sixteenth of this coagulable oxide to the evaporable water, that is, between five and six per cent, of the expectorated matter. '' 3. The impregnating substances have been shown to be muriate of soda, varying commonly between one and a- half to two and a half per 1000 of the expectorated matter — Potash varying between one-half and three-fourths of a part per. 1000— Phosphate of lime about half a part of looo —Ammonia,' united probably to the phosphoric acid ; phos- phate, perhaps of magnesia; carbonate of lime ; asulphate; vitrifiable n^^tter, or perhaps silica; and oxide of iron. But the whole of these last six substances scarcely amounting to one part in 1000 of the expectorated matter, it would be useless to estitnatethe proportion of each of them. Jt is very probable that the proportions and quantities of these ingredients vary much more than now represented in dif- ferent states of disease and health*. It is very probable aUo, that some of the ingredients may occasionally be ab- • In one case, the opaque expectorated matter in a pulmonary consump- tion havir.fT been exsiccated to bfittleuew, beeanje almost li'iuid aftw a night's •Kposutr to the air, sent^, ' ' On Expectorated Mailer. 19 sent, and others of a different kind be present, agreeably" to the different stutes, on different occasions of the other secretions. " 4. It is manifest that the different states of consistence of expectorated matter are owing to the proportion of al- buminous orcoagulable oxide; but I purposely avoid giving an account of the different conditions of heallh> on which' the differences of consistence depend. '*' 5. The thicker the matter, the smaller I <*ommonly found the quantity of sahne impregnation. . Hence, in sudden and copious secretions of the bronchial membrane, the niatrer is asserted to be salt, and to feel hot. In such instances., the proportion of coagulable matter was small,' but that of the saline impregnations, particularly of the muriate of soda, and neutralized potash, so great, that the exsiccated expectorated substance tasted very salt, and pre- sently grew moist, or even partially deliquesced ; but the opaque ropy or puriform matter atTorded a much larger proportion of exsiccated residue, which was but slightly salt, and generally only became soft on exposure tu the air. This property of growing moist depends upon the potash. " 6. Each of the human fluids, according to my experi- ments, contains neutralized potash ; at least, tliis is the fact of the blood, dropsy ffuid, pus of abscesses, and pus se- creted without breach of surface; the fluid effused by vesi- cating with cantharides; the urine; and in course in the very abundant secretion from the nose by a catarrh. The alkali beuig united to ox'^le of animal matter in these fluids, it is easily demonstrable. " 7* Although I think I have discovered many proper- ties by which expectorated secretic;n may be distinguished from expectorated pus, 1 shall not speak of them, on this occasion, further than just to observe that the saline im- pregnation of pus, particularly that of potash, and muriate of soda, is in very much less proportion than in expectorated secretion ; and hence it does not become moist after exsic- cation, on exposure to the air. " 8. It has been, I believe, uniformly asserted, that the circulating and secreted fluids are impregi-ljated with soda; that it is especially in the matter secreted by the bronchial membrane. The experiments of others must confirm or disprove mine. It seems, however^ much more reasonable, that the human fluids should be found to contain potash than soda, united to some oxide or destructible acid ; be- cause the former alkali is daily introduced with the vege- b 2 table flO On ihe lest Method of decomposing table food, and with the drink of termenleil hqiior; and ft is as little likely to be destroyed, as the muriate of sodaalsa induced in the very name way. But our food and drink do not, commonly at least, contain the soda united to a de- structible acid, or an oxide. ^< 9. It is plam, from the preceding experiments, that expectorated matter belongs to the class of coao;ulable fluids, and not of ge.atinizable, or, as commoi\ly as>erit'd, mu- cjous fluids. It difl'ers from the coagulable fluid, strum of blood, in forming a much thicker fluid with a much larger proportion of water : for serum, and aUo the water of blis- ters, is quite liquid, although they afford, on exsiccation, one-twelfth to one-eleventh of their weight of brittle resi- flue, while some kinds of expectorated matter, of the con- sistence of mucilage, afford only one- fortieth of dry residue, and others of the consisteu'ce of thin paste affbrd only one- fourteenth of residue. " 10. But for the unavoidable extent of this paper, I should trouble the learned Society with various other con- clusions and remarks^ especially concerning ihc glnbularit'if of expectorated matter, which seems to indicate organiza- tion. Although Antonius Van Lewenhoeck, above a cen- tury ago, discovered the globularity of the blood, and even noticed it in olher animal fluids, neither he^ nor any other person, as far as I know, investigated the subject in any- fluid but the blood, till by Mr. Home's aeutencss and in- dustry, at a Very early period of life, it was observed in pus i have in this paper related, that expectorated matter, especially the opaque ropy kind, >s well as the piriform, is full of globules, and that, except by such agents as de- stroy charcoal, they are scarcely destructible. Do these spherical particles consist chiefly of organized carbonaceou* ftiatter?" Ill* Memoir on the lest Method of decomposing the Chro^ mate of Iron, obtaining Oxide of Chrome, preparing Chromic Acid^ and on some Comhinalions of the Latter^ By M* VAuai>ELiN *. W HEN I made my first experiments on chrome, I had such a small quantity at my command that i* was impossi- ble to vary them so as to biiiig all its properties before my ?iew. • From AnnalM-dt Chimie^ tome Ixx. p. 70.- The the Chromate t)/ Iron, &€* 2! Tlie importance, however, of the oxide oF chrome, on account of its beauty and solidity as a green pigment f'of 'Carlhenware, and in forming imitations of emerald, added to the discovery of large quantities of chromate in the de- partnient of the Var, determined me to resume the subject, and to study the properties of chrome at greater length. In the experiments about to be detailed I was assisted hj M. Robiquet, an eminent chemist of Paris. Process for decomposing the Chromate of Iron. Chromate of iron is generally employed in order to pro- cure a large quantity of the oxide of chrome : this ore has for its matrix a kind of steatite, which, from its colour and some other physical properties, might be confounded to a certain extent with chromate itself, the more easily becausa these two substances at first sight seem to form one and ih© «ame mass : after a little attention, however, we find that the matrix is composed of long and pearl-like laminae, whereas chromate of iron is very fine grain^, shining, and denser than the matrix. I had formerly employed, in preparing the oxide of chrome, three parts of nitre to one of the ore reduced to fine powder; but I have since found this proportion was by far too large : indeed, as we can isolate the matrix but very im(3erfectly, it happens that the nitre, by means of the alkali which it sets free, attacks not only the chron)ate of iron, but also the aUnnine and silex, which are there in large proportions ; and thus the chromate of potash is mixed with an alkaline solution of all these earths, from which two inconveniences result : in the first place, we are under the necessity of employing, in the separation of these earths and the saturation of the excess of alkali, a great quantity of nitric acid, and if it happens that we go beyond the quantity of acid necessary to the exact saturation of the potash, we redissolve a portion of silex, but principally of alumine : in the second place, these earths, on bemg pre- cipitated, carry down with them chromate of potash, which cannot be freed from them by washing: a third incon- venience occurs, particularly when we operate on a large scale, and when the heat is necessarily long continued, — this excess of alkali attacks the crucible and melts it. Thus the oeconomy and success of the operation require that we should employ only one half part of nitre to one of chro- mate : by these means the mass does not enter into fusion, »nd the chromate is well attacked. It has often happened B 3 tha( SS On the lest Met hqd of decomposing that the potash has been entirely saturated with chromip acid. This decomposition being effected, the mass is to bp well lixiviated, ihe residue is then to be treated, when hot, with muriatic acid diluted in water, which takes up the iron, magnesia, alumine, and silex, divided by the action pf the potash and the subtraction of the cl^romic acid. The solution being terminated, the acid liquor is speedily "decanted, otherwise it would go into a jelly, and it would then be very difficult to separate the undecomposed chro- niate : the latter is to be once more treated as at first ; but instead of? employing the same quantity of nitre, a fourth part will be sufficient. When the chromate of iron is twr .^irely discomposed, we mix the solutions of alkaline chro- mate, m order to saturate them by the nitric acid, after .which it is proper to crystallize this chromate, as wrll in .order to separate some portions of earth which would' have .be<.'n dissolved by the excess of acid, as to take up a little phromate of iron, which is separated in brown dust by the progress of evaporation. We redissolve in water, filter, and precipitate the liquor by a solution of nitrate pf mer- cury at i\\Q minimum , containing the least possible quantity of acid in excess. Even supposing that the chromate of potash has been purified as we have indicated, i. e. that it contains neither earthy substance nor muriate, the chromate of mercury is precipitated in a more or less intense colour, accordmg to the state of concentration of the solutions, their tempera- ture, and excess of acid. In some circumstances the mole- cules of this salt, by approaching each other more slowly, assume more acfgregation, even crystallize, and thereby acquire a deeper red colour. We niay also remark that the first portions precipitated are the palest, because, in pro- portion as we subtract chromic acid, it has the same efiect on chromate of potash as if we diluted the liquor. To con- clude, the colour has no influence on the quality of the chromate of niercury. When the mercurial solution is employed at the mini' mum of oxidation, and as neutral as possible, there re- n)ains nothing in the mother water exce()t nitrate of potash and nitrate of mercury when a superabundance of these has been introduced : but in general these mother waters retain an amethyst colour, aiid yield with the alkalis a pale green precipitate, which, when heated, leaves oxide of chrome. I have the Chromate of lion, ^c. " 23 . I have attentively examined this precipitate, in order to become better acquainted with its nature and properties. When treated cold with caustic alkali it dissolves, and communicates a fine green colour to the liquor : a red pow- der remained which presented all the characters of oxide of mercury at the maximum. The alkaline solution, being fil- tered and subjected to ebullition, deposited a great quantity of green flakes of oxide of chrome, and preserved a line golden yellow colour: this was chromate of potash. Having d'iluted in water a portion of the precipitate ob- tained by the alkali of the above mother waters, I remarked that it was composed of two different substances ^ the first was flaky and light; the second, which always occupied the bottom of the mixture, was formed .of small crystals of a violet brown. These last presented the following proper- ties: 1st, When thrown on burning charcoal, they are entirely volatilized and condensed in small purple needles on such cold bodies as are exposed to their fumes. 2d, When heated more slowly in a retort, they furnish mer- cury, and leave green oxide of chrome as a residue : they are dissolved in weak nitric acid, communicating to it a fine yellow colour: if we pour into this solution nitrate of mercury at the minimum, common chromate of mercury is precipitated. 3d, When we treat this substance by^a caustic alkali, the latter acquires a yellow colour, and a red powder remains which is oxide of mercury at the 7naximum^ while the common chromate of mercury givt;s black oxide by the same process. The greenish precipitate obtained by the saturation of th^ mother waters, by means of an alkali, contains therefore green oxide and chromate of mercury at {hit maximiim. From what is above stated, we- may easily explain what takes place when the mother waters, although containir>g mercury in excess, nevertheless give a precipitate of chro- mate of mercury by the addition of fresh nitrate. The reason of this is, that although the nitrate of mercury at the maxi^ mum precipitates the chromate of potash, it requires but a very small quantity of acid in order to be dissolved : this in cjined me to think formerly that this' precipitation had not taken place, because t he mercurial solution, containing always an excess of acid, and being rarely at the perfect minimum^ the chromate at the maximum, on account of an excess of acid, is kept in solution ; but when we add a fresh quantity of nitrate of mercury, the portion at the minimum takes off the chromic acid from the red oxide which is deposited : if B 4 on £4 On the lest Method of dtcomposlng on the contrary we add alkali, we precipitate this chromat?! at the maximum. It now remains to explain how oxide of chrome is fomid in this precipitate: — the following experiment seems adapted to give a demonstration of it. When we treat chromate of mercury at the mininmm, by the nitric acid, the solution is eftectod without the extrication of nitrous gas ; but if we reduce the quantity of alkali necessary for the saturation of the acid, we obtain in the first place a brownish-red sedi^ ment formed of chromate of mercury at the rnaximum : the solution by this subtraction becomes areen, and preci- pitates, on the addition of a fresh quantity of alkali, green oxide of chrome, which is easily redissolved in an excess of caustic alkali. In this case, to all appearance, a portion of the chromic acid is de-oxygenated in order to hyper- oxidate the mercury, from which result chromate at the maximum and oxide of chrome. It is therefore certain that the chromatti of mercury at the maximum, found in the mother water, may arise from two causes ; either it results from the mercurial solution, if it contains oxide at the maximum, or it proceeds from the solution of the nitrate at the minimum, on account of the excess of acid, and then it is found mixed with oxide of chrome. The solubility of the oxide of chrome in the alkali fur- nishes the explanation of what passes, when on lixiviaii ng cold, the product of the decomposition of the chromate of iron by nitre, we obtain agrecn liquor which becomes yellow on ebullition; this is because the green oxide is deposited, which lays us under the necessity of fdtrating these lixi- viums before heating them, in order to separate this oxide in the state of purity. This last phaenomenon inclines us to tliink, with M.Godon de St.Memin, that the chromate of iron, so called in commerce, conta:ins chrome in the state of oxide; for it is improbable that the chromic acid is re- duced at the same time with the nitre. What still confirms the opinion of M. Godon is, that the acids extract a green oxide only from the chromate of iron. To return to the subject. We shall observe that it is es- sential to wash the chromate of mercury with a good deal of water, in order to free it completely from the nitrate of potosh, which, by the calcination of mercurial chromate, would again form chromate of potash, which produces a commencement of fusion in the oxide of chrome, conse- quently gives it a deeper bbade^ and renders it heavier, which we the Chromate of Iron, &c. fS we may avoid when the chromate of mercury is prepared witli proper care. I{ is sufficient, in order to obtain the oxide of chrome' very pure and of a very dne colour, to heat strongly in a well luted earthen retoit the pure chromate of mercury, un- til no more oxvgen is extricated, and to keep uj) the fire so much (he longer in proportion to the depth of the shade we wish to obtain : it seeins that there really exist two kinds of oxide of chrome, for by heating it a very long time the green is so weakened, that it passes to a dead- leaf yellow. Combination of the Chromic Acid with Barytes. In-order to prepare the chromate of barytes, we em- ploy with success chromate of potash well purified and very neutral ; we mix with it nitrate of barvtes until no more precipitate is produced : we must collect the latter, decant the liquor, and wash several times, until it is en- tirely freed from all extraneous saline j)articles. No harm is done by employing great quantities of watery even warm, in order to wash the salt, for it is not very- soluble. Analysis of the Chromate of Barytes, Five grammes of this salt, dissolved in the nitric acid and precipitated by sulphuric acid, gave four grammes and four tenths of sulphate of barytes. Admitting with M. Klaproth 68 parts of barytes in 100 parts of sulphate, we shall have, in 100 parts of chromate of barytes, 62-2 of base, and 37*4 of acid. According to this account, the five grammes of chromate of barvtes contain one gramme 87 centiemes of concrete acid, and the latter convened to the state of green oxide by a strong calcmation, is reduced to one gramme 56 cen- tiemes, which gives a difference between the quantity of oxvjren contained in 100 parts of oxide and 100 parts of acid of 16-6, i. e. in order to convert 100 parts of oxide of chrome into acid, we must combine with it 16*6 of oxygen. In order to effect the analysis of the chromate of barytes, we must dissolve it in weak nitric acid, aided by a little heat, and j)our into the solution sulphuric acid in excess; we then wash the sulphate of barytes, and weigh it after having dried and calcined it. With the same view, we may gently evaporate the !i- quor to dryness, in order to drive off the nitric acid ; re- ilis^lve the residue in water^ saturate it with ammonia,- and S6 Gn the best Method of decpmpos'r^ and calcine slrongly in order to evaporate the sulphaie of animouia and conjpletely deconij^ost' the chroiiiate oF am- jnonia : lastly, weigh the oxide of chrome. The latter, when boiled with nitric acid, onght to give no sign of sul- phuric acid with the nitrate of baiyics. If the proportions of the chromate of barytes which wc^ have obtained are very exact, as there hi every reason to believe they arc, the same analysis may serve for those of other chromates which are soluble in water. Process for ollainhg the Chromic Acid pure. Among the various methods which may be employed for preparing ihis acid, the most preferable, in our opinion, consists in decomposing the chromate of barytes by the sul- phuric acid : all other processes were attended with more or jess difiTiculties. We must therefore dissolve the chromate of barytes in weak nitrous acid ; afterwards carcj^ully precipitate it by means of sulphuric acid, so that all the salt may be decom- posed without the sulphuric acid being in excess. If by iihance we exceed this point, we must separate the superabun- dance of the acid by barytes water. We shall then find whe- ther we have seized the point at which the precipitate formed by chromic acid in barytes water is redissolved entirely iu nitric acid, and at which the sulphuric acid does not disturb ihis chromic acid. We then filter the liquor and carefully evaporate it, par- ticularly towards the latter part of the operation, that vie may not decompose the chromic acid : this evaporation must be repeated several times to dryness, in order to expel all the nitric acid. When the chromic acid is highly concentrated, irregular {mammeloniiees) nmsses are formed, in which we see small red crystals grouped together, but they are not permanent in the air, as they. attract humidity from it. The chromic acid thus purified is .of a deep red colour, has a very acid, but austere and metallic taste; ii is solu- ble in alcohol, which speedily deconsposes it, for the so- lution becomes green. luusy Method of determining the Quaniiiy of Chromic Acid combined or mixed loith several Saline Substances. We must put into the solution containing chromic acid a slight excess of nitric acid, if the salt be not of itself so- luble nor acid : we must then pour in a little hydro-sulphu- ret uf amuiouia, and auicer«ite for iouic lime iu a el'>sG, flasks after the Chromate of Iron, ^c, 27 after w?ilch we must boil in order to drive off ibe super- abundant sulphuretted hydrosien, filter in order to separate the sulphur, pour into the filtered liquor some drops of caustic potash, and thus obtain the green oxide of chrome ; filter again, wash caretuliy, dry and calcine carefully. Oil 4ddingto the quantity of oxide obtaine/J the l6*6 centiemes of its weight, we have the quantity of chromic acid which any given salt comained. We may easily see that in this operaiion the sulphuretted hydrogen makes the chromic acid pass to the state of green oxide, which the excess of acid takes up again in proportion as it is precipitated : if some portions of it remain, we succeed in separating it from the sulphur by ebullition, which serves at the same time to drive t»fi' the sulphuretted hydrogen. The potash after- wards added only serves to decompose the salt of chrome- ■\yhich is formed. Action of Sulphurous Acid on Chromic Add, IF into chromic acid we pour a great quantity of sulphu- rous acid, its ycllowish-red colour passes to a dirty brown; and if" at this period we pour caustic alkali into the liquor, we obtain a reddisfi-brown precipitate, which is dissolved in the acids. A greater quantity of sulphurous acid immediately changes the red colour of the chromic acid to a pale green. Thus it should seem that two kinds of oxide of chrome exist, but wUich scarcely differ in the quantity of oxygen*. Action of the Acids on Oxide of Chrome. In general the oxide of Qhrome obtained by the calcina- tion of the chromate of mercury is attacked by the acids with very great difficulty : we at length succeed, however, in dissolving it; but in order to form combinations we made use of the oxide obtained from the decomposition of the chromate of potash by means of the hydro-suiphuret, according to the process above described. We have seen that this oxide, when recently precipitated, is dissolved with the greatest facility even in trie weakest acids. The s«jiphate of chrome presented nothing reuiarkable; we merely observed that it is easily decomposed by heat ; for, when slightly calcined, it is no longer redissolved in watt.-. • We obtain an oxide similar to that which is produced by sulphurous acid in the former case, by passing oxygeaizcd muriatic acid into an acid sblutiun of green oxide of chrome, and into v.Jiich we gradual v pour a little pt»ta;sh. ...'.' - The tS On the lest Method of decomposing The muriate is so far remarkable, that when evaporated lo dryness, it gives a red powder which attracts humidity iVonv the air; Us soUuion is of a fine green colour. If we calcine it rather strongly, it gives out a smell of oxygenized niuriaiic acid, acquires a great bulk, and is transferred into small micaceous brilliant yellow fibres: finally, if we heat it still more, it is totally converted into green oxide. We boiled several times, and in large quantities, nitric acid over oxide of chrome recently precipitated, and it was completely dissolved; but when we separated the oxide by means of caustic potash, the supernatant liquor was co- lourless : the contrary is the case when we evaporate to dryness and slightly calcine: by redissolving in water, the latter assumes a reddish colour ; and after the separation of the oxide, the liquor remains of a fine golden yellow. We also dissolved oxide of chrome in phosphoric and in oxalic acids: the first combination was of a splendid eme- rald green colour, and the other, when viewed in the mass, presented an amethyst hue. Sulphurous acid also dissolves oxide of chrome with great facility. Action of the Caustic Alkalis on Oxide of Chrome, Tf into a solution of chrome a little diluted we ponf caustic potash in a quantity above what is necessary for the saturation of the acid, the oxide is redissolved in this aU kali. We also obtain an alkaline solution of oxide of chrome on taking it recently precipitated, diluting it with a little water, and dissolving in this water some pieces of caustic potash ; on afterwards diluting the combination with water and filtering, we obtain a liquor of a fine green, which, on ebullition, deposits the oxide it contains, and the liquor remains colourless. Chromate of Potash. There are two kinds of chromate of potash ; the one neu-* tral is of a citron yellow, and crystallizes in small prisms. This salt, on the addition of heat, assumes a fine red, but xetufns to its natural colour when cooled. The second has an excess of acid j its colour is orange-red, and it crystal- lizes in beautiful prisms of the same colour. Chromate of Ammonia. When we saturate ammonia by the chromic acid, an4 abandon the liquor to a spontaneous evaporation, an ar- borescent salt is formed out of the liqucjr, composed of tufts of fine yellow-: somelimes it is presented in the form of pearU the Chromate of Iron, ^c* 99 pearl-like laminse. To conclude, this salt is easily decom- posed by heat; even when it is dissolved, brown flakes are •eparated, which are oxide of chrome, and which become green by calcination. Chromate of Lime. Chromic acid forms a very soluble salt with lime ; its so* lution furnishes by evaporation silky flakes of a yellowish brown, which are easily dissolved in water r this salt is de* composed by the fixed alkalis. Chromate of Magnesia, Magnesia easily combines with chromic acid : the sail which results from it is very soluble in water; the solution crystallizes in prisms with six faces perfectly tran>parent, and of a fine topaz yellow : when they are in considerable quantity the colour is orange yellow. Magnesia is separated from the chromic acid by the fixed caustic alkalis and the alkaline earths. Metallic Chromaies, If into a solution of sulphcrttj of iron at the mim?num we pour chromate of potash, we obtain a fawn-coloured precipitate, which, when treated with caustic alkali, gives no trace of chromic acid : this precipitate is dissolved with 'great facility in muriatic acid, from which the alkali sepa- rates it completely without the least trace of alkaline chro- mate remaining. The nitric acid dissolves a part of the precipitate, and assumes a fine green colour : this precipi- tate therefore is not a chromate of iron, but a mixture or combination of oxide of iron and oxide of chrome, which seems to resemble strongly what is presented to us by na- ture. It is evident from the result of this experiment, that the chromic acid has been decomposed by the oxide of iron, which, in passing to the maximum^ has reduced the rather to the minimum, or to the state of green oxide. If we wished therefore to form chromate of iron, it vi'ould be necessary to employ this last metal saturated with oxvgen, in order that it may not be able to act upon that of the chrome. Chromate of Lead, This combination assumes different shades, accordins; to the manner in which it has been prepared. • If the chromate of potash be neutral, we obtain an ^range-^yellow colour; if it has an excess of acid, the co- lour 30 On decomposing the Chromate of Iron, ^c. lour is deep citron yellow : if the alkali on the contrary be predominant, the sluide is a reddish vellow , and sometimes a fine deep red ; the shades iilso vary in proportion as we operate in the hot or cold manner; Chromate of lead made vMih a solution slightly acid is that whieh is most in request by painters, and ii is m fact the most solid/ .We may heignicn its colour, either by a little alkali, or by precipitating it hot v\ith acetate of leadJ In the latter case it should seem tliat a part of the acetic acid is separated, and that the ox'de of lead which it aban- dons is i.iuted to the common cliromate and heightens its colour. We should conceive that the chromates which contain an excess of oxide of lead must be more alterable by sulphu- rous vapours than those in which this oxide is saturated by the chromic acid. Cliromale of Copper* The simplest way of forming chromate of copper is to mix a soluhon of neutral chromate of potasii with a solu- tion of sulphate of copper: a brownish-yellow precipitate is formed, which, when well washed and driedj assumes a bistre brown colour. Chromate of Silver, Chromate of silver is prepared by decomposing, nitrate of silver by neutral chromate of potash : a reddish-brown precipitate is produced when the operation is performed with heat, and of a pur|)le-red when done in the cold: lastly, it is of a carmine- red colour if the solution of chromate of potash contains a sligiu excess of acid : in the latter case the precipitate is not so quickly formed, and is less abun- dant, but it is crystallized in small semitransparent grains. This salt becomes brown on exposure to light; it is so- luble in the nitric acid, and from which the muriatic acid separates the oxide of silver. Uses to ivliich the Preparations of Cftrome are applied. This oxide is now G,enerally ertiployed in the porcelain manufactories throughout France. It supports better than any other metal, and without undergoing any alteration, the intense heat employed to prepare hard porcelain : it produces an extremely beauiirul green, which has not yet been obtained with any of the other metals. A very line enamel resembling in colour the emerald of Peru is made with the oxide of chrome. Another enamel is On Floating Bodies , &ci 31- U also made with it, which, when apphed upon copper or •ilvcp, furnishes a colour precisely similar to that uf fine gold, and imitates this bright metal extremely well when applied in thin leaves to other metals: a colour which, I think, cannot be obtained in the same degree of perfection with any other metal. I shall not dwell upon the difTerent varieties of chromates of lead used in painting: they arc already well known to- artists, and arc in great request on account of their beau- tiful colours, the facility with which they may be applied, and their great inalterability. It is very probable that several other metallic chromateg would also furnish beautiful colours if they were properly examined by painters. IV. Ohscrvations on loaded and unloaded Barges, Boats^ Beams, or floating Bodies descending with Streams or Currents, and wtiy the heavier End will go foremost^ By George Orb, Esq, In addition to what I have already said on this subject, I. now submit what follows to the consideration of scientific men : and as my object is an endeavour to attain the truth on so interesting a subject, I am ever ready to admit mv errors where 1 am wrong, but hope that reason and good temper, free from peevishness and personality, will evciv regulate the discussion of philosophical subjects. Wiien bodies of the dcscrintion alluded to, or in fact any bodies that are specifically lijibter than water*, float in it, there are two powers always opposed to each other, that is, the specific g'-avities oF the fluid and of tb.e floating body; and in proportion as these differ more or less, in the same proportion will the two bodies oppose each other : for the less specifically heavy any float in^' i)ody is, the less power will it possess to contend against the fluid in its endeavours to sink or descend ; and of course it will follow that it will float nearer the surface. When water is perfectly at rest, it has found its level, and its surface presents ahf^rizontal plane; or in other words, all its particles press or gravitate toward;r the centre of the earth in pcrpemliculir and right lines; but on any change from this slate of rest taking place, the particles of water are, by the force of gravitation, put in nioiion, and will endeavour to find their levari again, or continue to move on an inclined plane; and all bodies suspended in the fluid, •r fi^oating on the . surface more or less deep, beiiig subject. * * to 32 Oil Floating Bodies^ &c. to the same laws of riavit?ilon, take their direction with the moviiiii; fiuid, and thus pass dijwn tie sauje incliiied plane, wlih a motion mure or less ac derated as such bo- dies are heavier or ligluer ; thai is, as they po^?cssa greater or less power to overcome the resistance that may be op- posed to thtm. I think it is manifest from what is here said, that ihe motion which takes place with reirard to hotli duid and solid, is owing- to the attraction of gravitai.on ; anl as the velocities oi bodies arising fnjm this power are ijrtati'st in descendino" the perj)endicular to the plane ot the honz .n, 90 it will follow that these velocities will be diminished un- til the hue, along which they may descend, being carried from the perpendicular round the whole quadrant or right angle, arrives at the level or parallel to the horizon, Where, if the power of d(sce.iding be toiallv opposed, or the centre of gravity altogether supported, no niotion will take place. Hence it will folio. v that the vt^locitv of a stream, river, or current, and of course of bodies that fio.it in them, wiil be i^rc-aler or less, as the inclination of the plane on which ihey descend departs more or less from the line bounding the horizontal plane. Loaded barges, beams of heavv wood, &:c., without towing, and that float with the tide, will make a quicker progress than the tide ; the same will take place in a river or stream where there is no tide. Captain Burney having asked the bargemen on the Thames the reason of this, their reply was, '* That loaded barges had more hold of the tide from their floating deeper than unloaded ones." This was but a bad way of accounting for it ; but some reason must be assigned by those who continually observed this, and who Vv*ere ignorant of the real cause of it. The reason of this quicker progress seems to me to be this: any solid floating in a fluid, and descending with it, acts altogether in one mass ; and its particles thus acting together conspire to overcome the resistance they meet, and to divide the fluid, which, easily yielding to any pressure, will make way for the body in its descent pressing forward. Besides, the particles of the fluid do not act m conjunction, and being easily separated thev will roll about and impede each other by their friction, not only against each other, but also agiiinst the sides of the river, and the bed on which they descend. To this may be added, that less friction takes place between the fluid and solid, as they attract each other less, than between the innumerable particles of the fluid ; consequently the solid will glide on^ or slip through the liquid On Floating Bodies, ^e, 33 liquid body with a greater degree of velocity than the fluid, under the circumstances already enumerated, can attain. Captain B. savs, this greater progressive motion in the floating body is not owing to a iDore rapid under-current. I think not, but to the causes already assigned. Captain B. says, the surface of the ocean is an incfmed plane. I have stated in some letters several months ago in the Phi- losopliical Magazine, that the surface of the ocean, owing to the attraction of gravitation and its laws, and to the im- pression of the winds, &c., consists of an infinity of in- clined planes, or ascents and descents. No collision could take place between a heavier and lighter barge or body passing London bridge wiih the ebb of the tide, let them be ever so near, provided the heavier body were foremost, because on its descent it will, from its greater wcipht, acquire a momentum which will carry it on more rapidly than the lighter body ; but if the lighter body were foremost and very near, it might be overtaken, and a collision take place. When the wind blows strong into any bay, or against an embayed coast, there must be an under-current, because the wind prevents the return of the accumulated water along the surface. All pressure on bodies floating with streams must, whether the pressure be perpendicular oi- oblique, increase their progress : — if the pressure be perpen- dicular, it adds to tlie weight, and consequently to their power of overcoming resistance on the part of the fluid : if the pressure be obli(|uc, and in direction of the motion^ it will, besides increasmg the weight, give impu'se. The reason why ships at sea that are deeply loaded make less progress on a voyage than those that are lighter, and uhich seems to be in contradiction to what was last stated, seems to me to arise from the following cause : that is, that what they gain by their gravity over a lighter vessel in descending from the top of the wave or inclined plane, they lose in ascending the next; for it is manifest that the sur- face of the ocean consists of innumerable inclined pla^ies, or ascents and descents; but in a river or running si ream thf? whole progress is on a descent. Two pieces of wood of the same kind and of the same weight, but of difterent shapes, the one, for instance, a cy- linder with all its transverse diameters equal, the other of a conical form, with its transversediametcrsorlines all unequal, would, in my opinion, differ considerably in their progress in the same fluid, the cone making greater way than the cylinder; and to this I presume it iiiay be principally at- Vol. ^5. No. 141. Jan, 1810. C tributcd S4 Oh Floating Bodies, ^c. tribiited why one ship sails better than anothet*, andl which, on some future occasion, 1 may attempt to demon-* Btrate. Timber used at sea to find the direction of any current ought to be in its shape conical, and a good deal so, but the base of the cone to be rounded, or the sharp angles laken off, in order that it may pass more fairly through the water; for wood of this fhape vviil take the direction better, and be more easily observed : in such cases there should always be two conical timbers, and if they both take the same di- rection, the tendency of the current is certainly proved. No experiments can be made on this subject with South Sea clubs, such as captain B. used, nor with anything that will sink in water, 'that is, with any body specifically heavier than water. Supposing a barge loaded at one end and empty at the other, and without a helm, if it floated in a fair and regu- lar stream without currents, it would certainly proceed with the heavy end foremost, for the same reasons that a conical piece of wood, or even a cylindrical one loaded at one end, would go with their heavy end foremost in a fluid, though originally placed in a contrary direction : it would be the same with the cone and cylinder, if placed across a dry inclined plane ; that end containing the greatest quantity of matter, from its pov\er of overcoming resist- ance, would always have a tendency to be foremost. The inclined plane of rivers and streams must, from the number of inequalities at bottom, be a very irregular one — the cur- rent will partake of those irregularities, and the motion of bodies that float in them must be affected by them in a cer- tain degree. Lastly, Does a body floating down a stream or current, and which has a quicker progress than the stream or cur- rent, receive any addition to its motion from the motion of the fluid ? I think it docs not ; that it is only indebted to the fluid for its suspension, but that it is to its own gravity, and acting in one mass, that it is indebted for its greater progress. On the contrary, I think it loses in its velocity or progressive motion ; for though the floating body be specifically lighter than the water, and of course one would imagine that it would move slower, still, owir>g to the causes already enumerated, its progress is quicker : but there is a drawback on this progress ; because, if the solid overtake the water, part of its force must be wasted against that body which moves slower, but in the same di- fccliou. This cai» »6 analogous to that of two balls moving ivi On Ncevi Maiemi, 35 411 the same direction with dlfiferenl velocities ; that with the {greater velocity, on overtaking the other, cominunicatea part of its force^ and of course loses, so much in its ve- locity. V. On Ncevi Materni. To Mr,, Tilloch. tt-R, 1 HE last Number of your Philosophical Magazine contains a discussion, by one of your ingenious correspon- dents, in support of the old prejudice that certain congeni- tal marks or excrescences, commonly called 7icBvi materni, originate from the influence of the mind of the parent-. As the paper, no doubt, vvas written with a serious object, I comply with the writer's request in forwarding 'to you for publication some observations on the subject. It is agreed that ncevi materni resemble known objects m nothing more thanyb?^; although, as Enceps (the wri*- ter's signature) observes, " more than one volume has been filled with reputed instances of the effects of the mother's imagination upon her olTspring." The/orm^, however, of vcevi materni in general are so far from having a resem- blance to any known object^ that the experience of practi- tioners, who are in the daily habits of operating on some, and seeing many others, proves as much as extensive ex- perience can prove, that the relations of Ticevi materni re- sembling a bunch of grapes, or a bit of bacon, are to be classed with tne idle tales of the nursery. Even Enceps himself '^ vvas for a long time prepossessed with the same notion,'' viz. that such fanciiul forms of ncevi materni were ^* idle tales,*' till a case " was related to him by an mtelligent friend who had seen a child born with only one leg, as well as its mother, who declared her firm belief that the cause of this imperfection in her child was a violent fright which she experienced from seeing a beggar suddenly un- 'cover the wounded slump of his thigh." This, however, is not an example of nceuvs- maternus, but ot monstrosity, Kow 1 will seriously ask Euceps, at what period of preg- nancy this unfortunai.e mother received such a violent fright. In the latter mc^nths of pregnancy, ry/ifer. the limbs of the fcetus had been formed? The separation of a limb, and its siill more extraordinary annihilation, must then be explained as the efiects of imagination, — or in the early months of pregnancy, lefur@ the ovum had become organ- C2 ized] t6 On the Minemlogical Geography ized ! The i magi nation must then be supposed to act on a part of ihe foetus before such a part had any existence. The common opinion is, that monstrosity depends on original conformation of the ovum ; nor is it by any means intelli- gible that a metamorphosis or annihilation of any part of the foetus can lake place from an impression on the imagi- nation of the parent. I have said that Enceps's object in writing was not levity ; but when I came to the tale of the cat and the kittens, my suspicions were somewhat roused. *' A preg- nant she cat" had its tail trodden upon, and \o\ when she littered she had an even number of kittens ; otherwise the surprising things that did happen, coidd not have happen- ed— that " half of her kittens had their tails bent in the middle!" and that half hsid not. The circumstance which roused my suspicion was the gravity with which Enceps suys " this fact (or rather this tal^) seems to be very im- portant, and to prove nearly to a demonstration^ that the imagination of pregnant females has the power of acting on the bodily conformation of their young 11" As a medical man, I had reason to hope that the old prejudice of the perfection of the foetus being in anywise contingent on the imagination of the parent was at an end ; and having long been a. reader of your respectable Maga- zine, I could not observe Enceps*s reasoning in favour of such a prejudice, without presuming that it was subject to ■animadversion. I remain, sir, your humble servant, CfllRURGICUS. December, 1809. VL Memoir on the Mineralogical Geography of the Envi- rons of Paris, By Messrs, Cuvier and Brogniart*. X HE country in which Paris is situated is perhaps one of the most remarkable hitherto observed, from the succession of the various soils which compose it, and from the extraordinary remains of ancient organizations which it contains: myriads of sea shells, regularly alternated with fresh-water shells, form the principal mass : bones of ter- restrial aninials, entirely unknown even with respect to their genera, fill certain parts : other bones of species remarkable il'om their size, and the counterparts of which are only • AimaUtdu Musiuin d^Uistoirt NaturelUf tome xi. p. 293, foUlKi of the Environs of Tarts . 3 7 found in very distant countries, are scattered in the strata nearest the surface: a strongly- marked character of a great eruption proceeding from the south-east is imprinted on the forms of the eminences and the directions of the val- leys : in short, there is no district better adapted for making us acquainted with the final revolutions which put a ter- mination to the formation of our continent. This country has nevertheless been very little studied under this point of view ; and although so long inhabited^ by many enlightened men, whatever has been written on the subject has been confined io some detached fragments, and ahnost all of them are either exchisively mineralogical, without any regard to organized fossils, or purely geologi- cal, without reference to the position of these fossils. A memoir of Lamanon, on the gypsums and their fossil bones, may perhaps form the only exception to this classification : we are bound, however, to acknowledge that the excellent description of Montmartre by M. Desmarets, the information given by the same author as to the basin of the Seine, in the Encyclopcdie Mcthodique, the mi- neralogical essay on the department of Paris by M. Gillet- Laumont, the extensive researches on the fossil shells of theenvirons of Paris by M. Lamarck, and the geological description of the same district by M. Coupe, have been advantageously consulted, and have several times directed our steps. We presume to think that the task of which we are about to present the class with a sketch, will not be without in- terest, notwithstanding the works above alluded to. Four years ago we commenced our labours; and although we have persevered in them by making numerous excur- sions, collecting specimens and information from every quarter, we are far from thinking we have done enough, and we earnestly desire that our readers may not confound the abridgement which we are about to give, with the full details which we propose to publish. Some circumstances compel us to present this abridgement at this moment, and to assign a date* to such tedious and laborious researches, before the happy period at which we shall think them brought to a conclusion. From the nature of their object, our sketches were li- mited according to the nature of the soil, and not according to arbitrary divisions. We thought it right therefore, in the first place, to de- * Thi» Memoir was printed in Jan. 1809. — Edit. C 3 termine 3«! 0?i the ^Hneralogkal Geography^ terniiue the physical bouodaries of the district which it wa* our oLject to study. The basin of the Seine is separated for a long space from that of the Loire by an extensive high plain, iho greater part of which vulgarly bears the name of Beauce, and the middle and driest part of which extends from the north-west to the south-east, over an extent of more thaa forty leagues, from Courville to Montargis. This plain is bounded towards the north-west by a higher, and in particular a more broken district, from which the rivers Eure, Aure, Hon, Rille, Orne, Mayenne, Sarte, Huine, and Loire, arise. The highest part of this district is between Sees and Mortagnes, and which formerly com- posed the province of Perche, and a part of Basse-Nor- mandie, and which now belongs to the department of the Orne. The line of separation between Beauce and Perche pa«:ses close by the towns of Bonnevalle, Alluye, Iliers, Cour- ville, Pontgouin, and Verneuil. On all other sides the plain of Beauce overlooks every surrounding district. Its slope towards the Loire is not interesting to our sub- The slope towards the Seine is divided into two incli- nations, one of which on the wer^t looks towards the Eure, and the other on the cast looks towards the Seine. The first proceeds from Dreux towards Mantes. The other begins from the neighbourhood of Mantes, passes by Marly,, Meudon, P.daiseau, Marcoussy, the Ferte-Alais, Fontainebleau, Nemours, &c. But it must not be concluded that these two inclined plane* are straight or uniform ; on the contrary, they are in all direc- .tions unequal and rugged, to such a degree that, if this vast plain were surrounded with water, its edges would furnish gulfs, capes, and straits, and would be every where sur- rounded by small islands. In the same manner in our environs, the long mountain on which are situated the woods of St. Cloud, Ville- d'Avray, Marly, and Aluets, and which extends from St. Cloud to the confluence of the river Maulde in the Seine, would form an island separated from the rest by the strait in which Versailles is situated, the little valley of Sevres, and the great valley containing the park of Versailles. The other mountain in the Torm of a fig leaf, on which are situated Bellevue, Meudon, the woods of Verriere, and ^hgse of Chaville, would form ^ second island separated fro^^ cf the Bnvirons of Paris* 2$, from ihc continent by the valley of Bievre and that of tho hills of Jouy. But afterwards, from St. Cyr to Orleans, there is no longer ciuy complete interruption, although the rivers Bievre, Ivette, Orge, Etampcs, Essonne, and Loing, cut deeply into the continent on the east coast, while the rivers of Vesgre, Voise, and Eure, do the same towards the west. 'I'he most rugged and uneven part of the surface, and that which would furnish most islands, would be what h vulgarly called the GatinoU Frangois^ and particularly that part in which the forest of Fontaincbleau is situated. The slopes of this immense platform are generally very abrupt ; and all the ravines which we find in them, as well as those of the valleys, and the wells dug in the high parts, show that its physical nature is the same every where, being formed of one prodigious mass of fine sand which covers the whole surface, passing equally over all the other soils or inferior platforms which this great plain overlooks. The edge of this platform towards the Seine, from th« Maulde to Nemours, will therefore form the natural limit qf the basin which we are about to examine. From below its two extremities, ?*. e. towards theMaulde and a little beyond Nemours, immediately issue two portions of a platform of chalk, which extends in every direction and to a great distance, in order to form the wholt? of Haute Normandie, Picardy, and Champagne. The interior edges of this great girdle, which pass from the east by Montereau, Sezaime, and Epernay ; from the west by Montfort, Mantes, Gisors, and Chaumont, in order to approach Compiegne, and which form at the north-east a considerable re-entering angle which embraces the whole of the Laonnois, complete, together with the sandy coas^ now described, the natural liniit of our basin. But there is tliis great difference, that the sandy platform which comes from Beauee is higher than the others, and is consequently the most modern, and finishes completely the stretch of coast which we have marked ; while, on the contrary, the platform of chalk is naturally more ancient and lower than the rest, only ceasing to appear outside of tlie girdie above mentioned ; but so far from being at an end, it visibly sinks under all the other strata : we find it in short wherever we dig sufficiently deep under the latter, and it ev^en rises up in some places, piercing as it were through the other strata. We may therefore conclude that the materials which •ompose the basin of Paris, in the directions to which our C 4 incjuiric* 48 On the Mirwalogkal Geography inquiries were limited, have been deposited in a vast hollow or gulf, the bottom of which was ot chalk. This gulf perhaps formed a complete circle, or a kind of great hike ; but we cannot ascertain this, in consequence of its edges on the south-west having been covered, as well as the materials of which they were composed, by the great sandy platform first mentioned. We may add that this great sandy platform is not the only one which has covered the chalk ; there are several in Champagne and Picardy, which, although smaller, are of a similar nature, and may have been formed at the same time. Like it, they are placed immediately over the chalk, in the places where the latter was so high as not to admit of its being covered with the materials ot the basin of Paris. We shall in the first place describe the chalk, the most ancient of the substances which we have in our environs, and conclude with the sandy platforuj^ the most recent of our geological productions. In the intermedium between these two extremes we shall speak of less voluminous but more varied substances, which, had covered the great cavity of the chalk before the platform of sand was deposited on some of them. These substances may be divided into two soils (elages). The first (which covers the chalk wherever it was not suf- ficiently hiofh, and which has filled the whole of the bottom of the gulf,) is itself subdivided mio two parts of equal level, and placed not upon one another, but end to end : viz. The platform of siliceous lime containing no shells. The plati'orm of lime with coarse shells. We are sufficiently well acquainted with the limits of this soil on the chalky side, because the chalk does not cover it; but these limits are marked in several places by the second s©il, and by the great sandy platform which forms the third, and which covers a great part of the two others. The second soil will be named gT/pso-marle7/. It is not generally spread, but merely scattered from space to space, and as it were by spots ; these spots also, are very different from each other in thickness, and in the details of their composition. Ttiese two intermediate soils as well as the two extreme soils are covered, and all the vacuities which thcy.hav^e left are partly filled, by a fifth sort of soil, mixed also with niarle andsilex, and which we caWfres/i-water soily because ft abounds in fresh-water sheila only. We of the Environs of /^ans, 4f We have the honour to present the class with the first of 'Hi series of mineralogical charts, in which each kind of soil is coloured diifereutly. The sand is fawn-coloured; gypsum blue ; shelly lime yellow; siliceous lime violet; chalk red colour; fresh- water soil green streaked vviih white. We have here marked in plain green, ihe worn or alluvial sands which have not been tranquhly depo.sfted, but brought from other quarters by currents; and m dark brown the j)eaiy soils formed along the nvulets and round the pools of water. This fihe Environs 0/ Paris, %f The k)wermost strata of calcareous foritiatioji are the ' best characterized : they are very bandy and frequently ^en, rather sandy , than calcareous. When they are soHd, they are decomposed and fall into dust on the first ex- posure : this kind of stone therefore is not fit to be used. The shelly limestone which composes it, and even tl^ sand which sometimes supplies its place, almost always contain green earth in** powder or in small grains. Thisr earth, from our experiments, appears to be analogous to terra veronica. It owes its colour to iron ; it is found iit the lower strata only : we do not find it in the chalk, ia the clay, nor in the middle or upper calcareous strata, and we may regard its presence as a certain indication of the proximity of plastic cls^y, and consequently of chalk, 'But what characterizes still more particularly this system of strata, is the prodigious quantity of fossil shells which it contains. In order to give an idea of the number of species which these strata contain, it will be sufficient to say that M. Defrance has found more than six hundred species, all of which have been described by M- La- marck. W'e have to rcir^ark that most of the shells of the lowest of these strata are much further removed from the present existing species, than those of the upper strata. We shall mention among the fossils peculiar to these lower strata, periwinkles, oysters, muscles, pinnae, calyptreae, pyrdce, large tellines, tcrcbelloe, porpytes^ madrepores, and iparti- cularly nummulites and fungites. Such are the names of the most remarkable shells ta this stratum : we ought to remark that it was not in the depot of Grignon alone that we gathered the specimens we has'e described ; such examples would not have charac- terized the system of straia which we wish to make out readers acquainted with : we chose them from the quarries of Sevres, Meudon, Issy, Vaugirard, Gentilly ; in the strata of Guespelle; in those of Pallcry near Chaumont, &c. It is in this same stratum that we find the cameririeS'. They are either by themselv-es ol'mi'xed with madrepores and the preceding shells. ^ hey are always the lowe-st, and consequently the first which are deposited on the chalky formation ; but this is not the case every where. Wc hav® found some of them near Villers-Cottefet, in the valley of V^aucienne ; and at Chantilly on the flectivity of the mountain. They are mixed here with shells in good pre« scrvaiion, and with coarse grains of quartz, which, to-, gcihcr;^ make it -a kind of .puddingstune, on Mount Ga- ♦I ueloii 4S On the Mineralogical Geograpui/ fielon near Compicgne, and Mount Ouiii near Gi-* 8drs, &c. Another character peculiar to the shells of this stratura is, that they are mostly very entire and well preserved, be- ing easily detached trom their rock_, and some of them have preserved their pearly state. In all th^j preceding places, and in others, this is less remarkable ; because we ascertained that the sandy calcareous strata, which containt these shells, immediately follow the plastic clay which covers the chalk ; and it is by these multiplied observations that we recognized the generality of the scale which we have laid down. The other systems of strata are less distinct, and we have not as yet been able to arrange the numerous obser- vations which we have made, in order to establish witli precision the succession of the different fossils which ought to characterize them. We can announce, however, that, from our inspection of the quarries to the south and west of Paris, from Gentilly to Villepreux and Saint-Germain, the strata above those which we have described succeed each other in the following order. 1. A soft stratum frequently of a gree^iish colour, this is called the green bank by the workmen. It frequently ex- liibits on its lower surface brownish marks of leaves and stalks of vegetables. 2. Gray or yellowish strata, sometimes soft, sometimei very hard, and containing chiefly roundish venuses, cam- preys, and particularly luberculated cerites> which last arc sometimes in prodigious quantity. The upper and middle part of this stratum, frequently hard, is a very good stone building, and is known by the name of the rocfi. 3. Lastly, and towards the upper part, a stratum, not thick but hard, which is remarkable from the prodigious quantity of small long and striated tellines which it pre- sents in its seams. These tellines are laid horizontally, and closely wedged against each other. They are generally white. Above these last strata of coarse limestone we find hard calcareous marlcs divided into fragments, the faces of which are generally covered with a yellow coating and with black dendrites. These niarles are separated by soft calcareous- marles, by argillaceous marlcs, and by calcareous sjind, which is sometimes agglutinated, and it contains horny silex with horizontal zones. We refer to this system the stratum of the quarries of Neuilly, in which we find crystals of quart* and rhomboidal crystals of variegated carbonate of lime. r)f the Environs of Paris, 49 But what characterizes more particularly this last system of" strata of calcareous tbrmation, is the absence of every shell and of every other fossil. It results froin the observations which we have related: 1st, That the fossils of coarse limestone have been de- posited slowly and in a calm sea, since these fossils are deposited by regular and distinct strata; that they are not indiscriniinatcly mixed, and that most of them are in a Slate of perfect preservation, however delicate may be their texture; the points of the prickly shells being very often, unbroken. sdly, That these fossils are entirely diiTerent from those of the chalk. Sdly, That in proportion as the strata of this 'formation were deposited the number of the species of shells dimi- nished until no more are found. The waters which formed these strata either have not contained any, or have lost xh^ property of preserving tb.em. There can be no doubt that things went on very differently in these seas from what they do at present in the waters of the j>resent day ; where no strata are formed, the species of shells found in them are always the same in the same regions; we do not find, for example, since we began to fish for oysters on the shores of Concale, that this kind of shell-fish has been replaced by other kinds. Art. IV. Gypsous Formation, The soil which we are now about to describe, is one of the clearest examples of what is meant by the word forma- tion. Here wc find strata very different from each other ia their chemical nature, but evidently formed together. The soil which ^we call gypsous is not composed of gyp- sum alone, it consists of alternate strata of gypsum ai?d of argillaceous and calcareous marie. These strata have pursued an order of superposition, which has been always the saiiie, in the great gypsous girdle which we have studied, and which extends from Meaux to Triel and Grisy. Some strata are wanting in certain districts ; but those which re- main are always in the same respective position. The gypsum is placed immediately above the limestone, and it is impossible to doubt this superposition. The posi- tion of the gypsum^quarrics of Clamart, Meudon, and Ville- d'Avray, is above coarse limestone wrought in the same places ; that of the quarries of the mountain of Triel, the superposition of which is still more evident; lastly, a well Vol. 35. No. 14U*^/i. 1810, P dqg 50 On the Mineralogical Geography dug in tlic garden of M. Lopez at Fontenay-aux-Roses, which first passed through the gypsum, and afterwards the limcsioue, are ample proofs of the position of the gypsum on the limestone. The gypsous hillocks have a peculiar appearance, which renders ihcm conspicuous at a great distance : as they are always placed upon the limestone, they form on the higher eminence a kind of second conical or elongated hillock, always distinctly marked. We shall exhibit the details of this formation, by taking, as an example, the mountain which presents the most complete collection of strata; and although Montmartrc has been already well described, it is still the best and the most interesting example that can be selected. Wc have recognized, both at Montmartre and on the hillocks which seem to form the continuation of this emi- nence, three masses of gypsum. The lowermost is com- posed of alternate and thin strata of gypsum, frequently selenitous, of solid calcareous marles, and of very scaly argillaceous marles. It is in the former that we chiefly see the coarse crystals of lenticular yellowish gypsum, and it is in the latter that we find the menilite silex. We are not acquainted with any fossil in this mass, which is the third, of the quarries. The second or intermediate mass differs from the fore- going only because the gypsous beds are thicker, and the marlcy strata are less numerous. We ought to remark that among these masses, that which is argillaceous, compact, and of a marbled gray appearance, serve* for building-stone. It is chiefly in this mass, that fossil shell-fish have been seen. No other fossils, however, are found in it ; but sulphated sirontian has lately been discovered in it, in scattered frag- ments, in the lower part of the marble-like marie. The superficial mass, which the workmen call the first, is in every respect the most remarkable, and the most im- portant. It is, besides, much more extensive than the rest, iince it is m some places 25 metres (S2 feet) thick, inter- rupted only by a small number of marley strata; and in some places, as at Dammartin and Montmorency, it is si* tnated almost immediately under the vegetable earth. The lo\v;ermost beds of gypsum in this first mass con- tain silex. The silex and gypsum seem as if mutually dissolved in each other. The intermediate beds arc na- turally divided into coarse prisms, with several pbnes, which M. Desmarets has drawn extremely well. They are called ih^ high pillars^ Finally, the uppermost strati are t)f the Environs of Paris, 51 £lr(y ihlcrlaic! witli marie: they are but thin? and are alter- iiateti wiih slratn oK inaric ; thefe are gqiieraily five such, which are continued to greai distanccsi But tiicst: facts, which are already known, are not the most important : we mention li^cui onlv thai they may be brought under view at one glance. Tiie fossils which this mass contains, and those coniidned in the marie that covers it, present obfcrvations oF a thlTcrent interest. It is in this first mass that we daily find the skeletons of unknown birds and of quadrupeds, which have been already described by one of us (M. Cuvier) in a separate memoir'^"* 1\) the northward of Paris they are in the gvpsous mass itself; here they have preserved their solidity, and are only surrounded by a very thin stratum of calcareous marlc ; but ill the quarries to the southward, they are frequently in the marie which se}>aratcs the gypsous strata : they have then a great de«iTce of friability. We 'shall not revert to the manner in which they are situated in the mass ; upon their state of preservation, species, &c. these objects having been siifficientlv develoi)ed in the Memoirs wliich wc have men- tioned. We have also found in this mass, bones of tortoises and skeletons of fish. But what is much more remarkable, and much more im- portant from the consequences that result from it, is, that we find, althouirh very rarely, fresh-water shells. Indeed^ one only is snflicient to demot^strate the truth of the opi- nion of Laniitnon and some other natur;ilists, who think that the gvpsums of Montmarlre, and of the other liillocks of the basin of l^aris, have been crystallised in fresh- water lakes.* We shall relate new facts in confirmation of this. \\\ the last place, the superficial mas^i is essentially eharac- •te^rized by the presence of the skeletons of mammiferss. These fossil bones serve to point it init where it occurs in isolated masses ; for we have never been able to discover that they have been found in the lower masses. Above the gypsum are placed strong strata of marle^ sometinjcs calcareous, .-^nd sometimes aigillaeeous. ft is in the lower beds, and in a while and friable calca- reous mass, that we have at various times met with trunks of palm- trees converted into silcx. They were lying flat, and of a large bulk. It is in this same system of strata that we found (hut onlv at Rdujainville) shells of the genus lijmiwa And pld/iorbes, v\hich seem to differ in no respect from the species now existing in our marshes. One of us has already comnumicated this important fact to the class. * V\.\b\:shed in ytunales'ru Muivufn. . JD 9 St On the Mhieralogical Geographic It proves 'that these marles are of fresh-water formaiiorify like the gypsums which they cover. Above these white marles a e also seen very nunncroua and frequently thick argillaceous or calcareous marles, in which no fossil has been as yet discovered. We aFterwarcb met with a small bed six decimetres (24 inches) thick, oi a scaly yellowish marie, which contains towards its lower part scraps of earthy sul phased strontian, and a little above a thin bed of sn>all elongated tellines, which are lying flat, packed closely into each other. This bed, which seems to be unimportant, is nevertheless remarkable in the first place from its great extent : we have observed it over a space more than ten leagues (27i miles) long and more than four ( 1 1 miles) broad, al way9 in the same place and of the same thickness. It is^so thin, that we ought to know pre- cisely where it lies, in order to find it out. Secondly, because it serves as a limit to the fresh -water formations, and indi- cates the sudden commencement of a new marine formation. In fact, all the shells wliich we meet with above this bed of tellines are also marine. We find at first, and immediately afterwards, a strong and constant stratum of greenish argillaceous earth, which from its thickness, colour, and continuity, may be recog- nized at a great distance. It serves as a guide to the tellines, since it is beneath it that we find them. It contains no other fossil, but merely argillo- calcareous geodites and scraps of sulphated strontian. This earth is employed in the manufacture of coarse pottery. The four or five beds of marie which succeed the green earths are not thick, nor do they seem to contain fossils ; but these beds are immediately covered by a stratum of yeU )ow argillaceous marie, which is strewed with fragments, of sea shells which belong to the genera ceritcs, trochi, mactrcs, venus, cardium, &c. We also meet wiih frag- ments of the bones of a thornback. Almost all the beds of marie which succeed the latter present fossil sea shells, but they are bivalves only ; and the last strata (those which arc inmiediately below argilla- ceous sand) contain two very distinct oyster beds. The first and lowerniost is composed of very thick large oyster- f hells: some of them exceed a decimetre (4 inches) in length. Afterwards comes a stratum of whit is*!) marie, without shells, then a second very strong oyster bed, but subdivided int'elopes. Article IX. Formation of Alluvium {Atlerissemeni), Not knowing how to designate this formation, we have given it the name o{' alluvmm, which indicates a mixture of ^laltpr deposited by fresh water. In I'act^ the slime of al- luviatioa 58 IMineralogical Geography of the Environs oj Paris, hiviation is composed of sand of all colours, niarle, or even of the mixture of these three substances, impregnated with carbon, which mves it a brown and even black appear- ance. It contains rounded flints ; but what characterizes it more particularly is, the remains of the huge organized bodies wirh which it abounds. It is in this formation that we find large nunks of trees, bones of elephants, of oxen, antelopes, and other large mammiier^. It is also to this formation that we may ascribe the ac- cumulation of flints at the bottom of valleys ; and probably also those of Siome plains, such as the Bois de Boulogne, the plain of Nanterre at Chateu, and certain parts of the forest of St. Germain. This alluvium is not only found in the bottom of our present valleys, but it has covered valleys or excavations which have been since filled up. We may observe this ar- rangement in the deep cutting made near Scran, for the ca- nal of Ourque. This cutting shows an ancient cavity, filled with the substances which compose the alluvium, and it is in this kind of marshy bottom that we have found bones of elephants and large trunks of trees. It is to the existence of these ruins of organized bodies which are not yet entirely decomposed, that we ought to ascribe the dangerous and frequently pestilential emana- tions which are extricated from these soils, when they arc stirred up for the first time since the period of their forma- tion ; for it is the same with this formation, which appears to be so modern, as with all those others which vvc have examined. Although very modern in comparison with the other soils, it is still anterior to any historic jsra ; and we may say, that the alluvium of the old does not in any re- spect resemble that of the present world, since the wood and animals found in them are ei'itirely different, not only from the animals of the countries where they are found de- pobitedj but also from all those hitherto known. VII. ^fc- L 59 ] VIT. Account of an extensive Organic Lesion of the. Brain, thoracic and abdomiiial Viscera, nnaccojnpanied ly the Syntptvvis usually olserved in similar Aff'ections, ^7/ John Taumton, Escj. Ledwer on Analomy, Surgeon to the Cily and Finslury Dispcmaria^, and to the City Iruss Society, ^c. To Mr, Tilloch. Sir, In the course of my various communications to your Journal, I have more than once had occasion to describe casts of injuries to vital parts, which are generally suj.v- posed to produce a suspension if not a total deprivation uf the reasoning faculties *. In detaiUnfi; the remarkable appearances I am about to lay before tlie public, it is not my ^vish to be regarded as espousing a doctrine contrary to the generally received opi- nions respecting the connexion that subsists between the oriranic structure and intellectual faculties of mankind : — I am anxious, however, that the anomalies which daily fall under the observation of medical practitioners may excite them to further inquiries. It has been my lot to witness cases in which the bones of the cranium havelicen sodemolislied, that large portions of the brain escaped from the wound; and on other occasions besides the one I am about to de- tail, 1 have found tumours of an inch and upwards in di- ameter, formed on the surface and substance of that viscus, and yet no symptoms of mental derangement, stupor, or even loss of sight, hearing, &c., supervened. (On the other hand, I am free to aduiit, that 1 have seen lesions of this dcb'cription, nay even the most trifling depressious of the skull, producing all the disagreeable consequences which we are taught to expect from injuries of the head. May there not be sonie chasm in the theory of physiologists oji this point, wliich is re«erved to future observers" to frli wp ? In November last I was called to a M. De la Roche, a foreigner, who described his age as 67. He detailed the circumstances of his case, with a firmness and precision, which perhaps no patient, labouring under such a compli- cation of disorders, ever before evinced. On examination I found a fistulous sinus in the i>lutii muscles, which h^ informed me had existed for many years : he had long complained of great pain in thp left -eavity of the thorax, * Sec Philosophlciil Magazine, vol. xxix. p. 169,. and vol. xxx. p. S63. ofterx 60 Account of an extensive often placing bis band on tbe aflfcclecl part : — in other re- flpects bis healib bad been previously good. He was re- garded as a most active man : be bad a general knowledge of literature and science ; spoke several languages ; was dislinguisbed for tbe facility witb which be could converse upon most subjects, and reasoned so closely that bis intel- lectual powers were generally regarded as of a superior kind. He had been repeatedly employed by the late Mr. Pitt ou missions to various j)arts of the contmcnt, and had invent- ed several improvements in mechanics, which had gained ^im considerable notoriety. About two months previous to my seeing him he had been seized witb what was pronounced by •: medical gen- tleman who visited bin), to be peritoneal inflammation. This gentleman bavins; discontinued bis attendance. I was sent for by the patient ; not so much with a view lo admi- nister any professional aid, as to express my consent tQ ^'anatomize bis body" alter his dissolution, which he jicvcr ceased to contemplate as rapidly approaching, with a firmness of mind peculiar to himself. This singular, and I believe almost unprecedented request, was even com- mitted to writing by tlie patient, and delivered to a parti- -cular friend. On further inquiry I learned that be felt considerable pain also in the abdomen, and on aj^plying my hand ex^ ternally I felt a tunKuir in the scrobiculus cordis, extending to about midway between that part and the unjbilicns j but ibis tumour was not sensible to the mere casual touch. His pulse was good, and did not indicate inflanmvuion ; but be appeared to be gradually sinking } he look but little nourish- ment, and did not rest well. The njedicines administered were opiates witb aperients, ^vbich aflbidid some temporary relief. A lew days previous lo bis death he bad several convulsive fits: be lost the use of his left side before death ; but the ciienlation and beat in that part of his body were uninterrupted ; the lower ex- Utmiiies at this time i«lso becanie anasareous. He con- linued perieclly sensible to tbe moment ot his dissolution, ETamination of the Body, On sawing off the upper part of the cranium, the boncg appeared periectly diaphanous : — the membranes and surface of tbe brain were in their natural state '1 lie generaf sub- stance oF the brain was lirm. On separating the hemispheres, there appeared attached .K> the ri^ht hcaii«phere a dark-coloured tumour of at least Organic Lesion of the Brain, &c. 6i ^iri inch in diameter ; it was of a granulated, fibrous and grumous consistence. VVirhin ihe substance of the sann(* hemisphere thtre appeared several other tumours, whicli^ on being cut into, exhibited nearly the same appearances. The general substance of the brain was firm and sound : the olfactory nerves were uncommonly firm, not having the usual fibrous texture, but rather resembling pieces of nar- row tape, of a dead white colour ; the other nerves were equally firm. In the thorax the left lung was entirely obliterated, ap- parently resulting from long continued inflammation. The right lung and the heart were in their natural state. The eoronary arteries were ossified to a considerable extent*. In the abdomen there was about three quarts of a dark-* coloured serous fluid; the viscera were of a very dark co- lour. The structure of the alimentary canal was not in- jured: the kidneys, bladder, and spleen, were in the na- tural state : the liver was completely scirrhous; the pan- creas was also scirrhous, which must have formed the tu- mour felt while the patient was alive. The gall bladder wa» much distended with bile. There were no symptoms of a scirrhous pancreas during life. With respect to the diseased appearances of the trunk in: the above case, perhaps little doubt can arise; but it may not be improper, before I conclude, to call the attention ©f my fellow practitioners to the peculiar state of thebrain^ The tumours in this organ were exhibited in various ttages of progression to the size of the largest, and that which was first described. The whole of them must have «?iisted for many years, and it w^ill perhaps be difficult to ex- plain— Why these tumours did not produce symptoms of compression, considering the space they occupied? Or are we to suppose that absorption of the surroandinc parts took jplacc in unison with the growth of the tumour ? 1 am, See, John Taunton f. • Although thU OFsificailon vrz3 extensive, no 53'mptoms of angina pec- t^iris could l)e traced as havinrj ever existed. Sever;:i prcparatiaus in my pcsiession, when considered with reference to the hiitories of the patients, furnish results pert<:ctly analog-ous. ■f The preparations of the various diseased parts in the above case arc f rduM-Yf^ m »> Mbs€ui», tvke«e thejr rnncy ba seca. Vin. Qa t C2 ] Vni. On Dr, Pearson's Proposal for an Instiiulion fof obtaining an equal Temperature in Houses, To Mr, Tillocli. Sir, 1 WAS much gratified by Dr. Pearson's letter in your last number, announcing the probable erection of a large building, capable Of having its atmosphere kept at an equable temperature, for the use of consuniptive patients. Though no medical man myself, I have more than once had my attention directed to this subject; and I have long been of opinion, that such a building as Dr. Pearson alludes to, would be, in most cases, a palliative, if not remedy, superior to the removals to a milder foreign climate, which are sa frequently painfully undertaken. That a combination of the architectural and philosophical sciences existing in England is adequate to the erection of a building, in which the air could be constantly maintained of a temperature as mild as that of Montpeliier or Madeira, and of which the superior equability would more than compensate for any slight deticicncy in freshness and purity, there can be i\o reasonable doubt ; and how infinitely more, if this could be effected, a quiet residence at home, surrounded by at- tentive friends, must contribute to the care and restoration of a sufferer by a consumptive attack, than a harassing voyage, succeeded by an uncomfortable sojourn amonrst strangers, need not be pointed out. But, though I entertain sanguine hopes that, under the auspices of Dr. Pearson and the eminent architect he re- fers to, the consumptive rich may be shortly accommodated nmongst us with a splendid erection of another Albany^ of which while the air is as mild and balsamic as that of southern France, the extent and arranii;ements will admit of the indulgence of fashionable habits, and combine within itself the luxurious enjoyments and comforts of home, with, the licalthful influence of foreign climes; it would greatly detract from my satisfaction, if I conceived that these bless- ings were to be confined to the rich, and that the con- struction of a splendid and expensive edifice was 2isine qua- ?i07i to their attainment. I am persuaded, however, both from Dr. Pearson's hints and my own observations, that at least the remedy of a mild and equable temperature may be compassed by persons in the middle station of life, in their own houses, and at an expense not exceeding what they would of necessity expend in applications far less efTica- cious. The first csseiuial seems to be merely a suite of twq aic- On Dr, Pearson's Proposal, <^c, 6^ air tight apartments and an anti-room opening into each other, and having no other communication with the rest of the house than through the anti-room. Ot" these the: first would servd'for a sitting-, tlie innermost as a lodging- room. It is quite obvious, tliat all attempts at maintain- ing an equable temperature must be nugatory, if the patient have to pass from his sitting- to his lodging-room through a cold windy pasi?age or staircase ; and if the atmosphere of both be not kept at the same degree of warmth. There arc few houses, of modern construction that could not sup- ply two rooms on the sanie floor opening into each other : afid as the anti-room, which is essential for the purpose of preventing a cold draught of air on opening the door of the outer apartment, and for renewing itie air of that apartment gradually, may be very small, there are few houses which would not admit of its erection on the stair- head of the first' floor. The next essential is to make the rooms air-tight. This may be readily accomplished by doulde windows, the outer closely caulked, by walls accu- rately plastered and papered, and doors tightly fitting and listed if necessary. An equable temperature is the third essential. \\\ effecting this, fires in an open stove seem clearly inadmissible, if from no other cause than this, that in an air-tight apartment it is almost impossible to prevent their smoking ; besides which, it is equally diffi- cult to regulate their heat properly. S'/oye^ of all kinds are open to the last objection, and frequently cause an unpleasant and unwholesome smell, even when the smoke dot's not escape. Steam would doubtless be the most ef- fectual and elegant, as well as simple and piirhaps cheap mode of heating the ap^irtments. All that is waiued is a plain and intelligible description of the mode of its appl'f- cation, which could be practised by any ordinary workman. Here 1 confess my ignorance : indeed niv chief reason for now addressing you is to request of Dr. Pearson, or some other of your intelligent correspondents, the requisite in- formation. We were told long ago, that some eminent cal)inet-maker was able to warm'a large suite of rooms, even the garrets of his warehouse, fron) the steam of a single copper ; and 1 understand steam is applied also in warmmg the Royal Institution: so that the practicability of applying it in this way is undoubted. What is wanted is the man- ner of its aiij)lication, on a small scale, in private houses. I should conceive that a boiler, which might be fixed on one side of the kitchen-fire, would heat water sufikieut to warm the air of. two moderate-sized rooms. From this 6 boiler 64 On Df, p€arso7i*s Proposal for an Insttiulion boiler a tin pipe mighl be conducted, being wrapped with wool, or some non-conducting substance, until its en- trance into the apartment to be warmed, and then unco- vered to give out its beat. If sufficiently long or wide, and made always to incline towards the ooiler, I should conceive that the greater part of the steam would condcn^fe and run back into the boiler; but of course there ought to be some outlet or valve to prevent the pipers bursting* The chief data wanting are the size of the boiler and quantity of water necessary to heat a given space; the proper dia- meter of the pipe, the length to which it ought to extend in the room to be warmed, and its situation, whether near the floor or the cielins:, Sec. &c. It is clear, that as little of the steam o:ight to escape uncomli-nsed as possible ; and for this purpose, the tube in the room should be either ver^ long or very wide, but which I know not. If the appa- ratus could be so contrived that the condensed water would return to the boiler, it u-ould be a material point; for the great difficulty in adopting such plans is the impossibility of gettmg servants to attend to any directions which re- quire frequent and precise observance. It is on this ac- count that the steam-boiler should be immovcably fixed, and constantly heated without any particular care. A steam apparatus, something on the plan above de- tcribedy would, 1 conceive, be far more effectual, as well as less troublesome, than the pots of hot water temporarily .used by Dr. Pearson ; and a simple and cheap mode of applying it is highly desirable, not merely as a mode of heatinu: the apartments of consumptive patients, but for General adoption in many other cases ; in particular, for heating rooms where collections of plants, 8cc. are to bo kept dry, but free from the dust and dirt which an open fire never fails to make. In concluding this part of the subject, I \N ish to inquire whether the Pcnjisylvanian stove, invented by Dr. Franklin, and which, from his discoveries^ seems to conibme the warmth and cleanliness of a stove with a sight of the fire, so essential to an Englishman's comfort, has ever been adopted in this country, or had a lair trial given to it ? Though there can be little doubt tluit a suite of rooms warmed \\\ the manner indicated above would be a very good succedaneum during an Eniiiish winter for an ex- pensive voyage to Madeira or Lisbon, and though they who are in:pressed with a proj)er sense of the honors pf con- ' siJinpiion would deem the consequent eonllnement as a trilling price for the advantage derived; it is kiot to be de- nied for obtaining mi equal Temperature in Houses, 65 nied that it would be found very difficult to induce con- sumptively-inclined patients to tbrgo the pleasure of out- door exercise, and submit to such a confining regimen. But it has long struck me, that means might be devised to enable this numerous class, who purchase every sunny walk innvinter with the risk of their existence, to enjoy their present liberty with far less danger. It is well known, that the great source oF harm to persons with tender lungs is the sudden and great changes of temperature, especially i\oi\\ cold to IieLitf which no one who stirs out in an Eng- lish winter can well avoid. The succession of a cold frosty air to the hot temperature induced by a large fire and tea; then perhaps a walk on the sunny side of a street, ex- changed for the piercing cold of the shaded and exposed side ; and the whole ended by entering into a hot room, and rushing to a large fire, where the irritability, or whatever we call it, of the botly is extraordinarily condensed : — sucli is the succession which thousands are every winter repeat- edly exposing themselves to : And can we wonder at the result to those who are of a consumptive habit? But how to avoid these changes and yet stir from home is the ques- tion. In one way this may be certainly effected : — by the application of a handkerchief to the mouth and nose, so as to prevent the air from ever passing into the lungs when in its coldest state, much of the danger of short excursions in the, open air maybe prevented. Of, this fact I have had ocular demonstration in the case of a friend, who, before his adoption of this plan, had constant and severe colds through every winter, but, smce he pursued it, has been nearlv if not altogether free frgm them. And this gentleman is now able comfortably to accept winter invita- tions, which formerly he was under the necessity of de- clining, or of looking forward to with horror. But would it noi be practicable to invent a substitute for the pocket-handkerchief, which it is tiresome to hold, and too closely confines the breath ? Might not a kind of mask consisting of a frame, which should closely apply to the lower part of the face, covered with three or four thick- nesses of gauze, be very advantageously employed for the same end ? Such a veil would, I conceive, constantly keep the lungs in an atmosphere never much below sixty, while the interstices of the gauze would readilv admit of the re- quisite quantity of uir, which, thus gradually mixed with the interior warmer mass, could never, even in the coldest weather, cool the membrane of the lungs so as to make it dangerous to come into a warm roora^ or approach a fire. Vol. 35. No. 141. Jc/i. IblO. E The 66 Nbticei respecting New Books, The only objection that I can see, is the ridiculous figure that persons liimished with such masks rvould at first be thought to cut. But this would soon hnve an end. The adoption of such veils by a few ot" the great would be suffi- cient to induce even the robust to wear them ; and in re- ality there would be much less to laugh at than there was at the tirsi use ot umbrellas, inasmuch as a man's lungs are somewhat better worth protecting than his coat. I shall he glad if these hasty and indigested hints prove of any value in furthering the laudable views of Dr. Pearson. I am, sir, your most humble servant, .Jan»ary 15, 1810. CeNEPS. IX. Notices respecting New Books, ^^ The Hudiments of Chemist ry, illustrated by Experiments, and eight Copper-plate Engravings of Chemical Appa- ratusJ* By Samuel Parkes. Price bs, in Boards. X here is much to commend in this little volume, which contains the principal chemical, facts, detailed with pre- cision and perspicuity, and illustrated with apposite expe- riments : but alter the luminous discoveries of Mr. Davy, — discoveries which have entirely changed the relation and dependence of the various facts w hich constitute chemical science, — we cannot but express our surprise that Mr. Parkes «hould have adopted such an arrangement as the following : — Introduction; Atmospheric Air; Caloric; Water; Earths; Alkalies ; Acids ; Salts ; Simple Combustibles ; Metals ; Oxides ; Combustion ; Chemical Affinity. In typography and mechanical structure the present work is an exact pic- ture of Blair's Grammar of Chemistry, nor could a better model have been followed for an elementary work of this kind ; but justice demands that we should add, it is far more' correct in its detail of facts. ''^ A?i Essay on the Effects of Carbonate, and other Pre- parations of Iron, upon Cancer : with an Inquiry into the . Nature of thai and other Diseases to which it hears a Re- ,latw?i,'* By Richard Carmichaki, Surgeon, Second Edition, considerably enlarged and improved, _ 8i/o, Dublin printed, and sold by Murray, London, Though subjects of medicine may fijid their way to the public by publications confined to that science, yet, as a branch of natural philosophy, we have always been ready to receive a selection. The disease to which this work rc- ler3 , Nbiices respecting NetO Boohs, 67 fers ir> too wdl known in its fatality to require any intro- ductory remarks, but the remedies have for ihe most part heen eoncealed lrr)m the public. Hcnee, i?/)litary suecess- tiil cases. ou'y having been published with care, the faculty have been unable lo judiie of the comparative value of a. remedy th-ev could know but imperfect Iv". Nothing there- fore could be more desirable than a p-.ri'orniance like Mr. Curnncha^l's, nor could anv thing be ushered into the. world with more modesty or pn^prietv. *' When I first published," iays the author, *' my Essay on the Etfecls of. Carl)onale of Iron upon Cancer, there was naihing I so much dreaded as the loo sanguine expectation ot the public, and that a remedv that succeeded in one instance would he required in every other tt) overcome this disease in all its stages, or be rejected as useless because it could not per- form impossibihtics. My own hopes were but moderate, and 1 v^as careful that they should not wander far beyond the certainty of my CNperience; but my experience was sa circumscribed, that 1 could merely gues^ at the virtues of the medicine rather than appreciate its value. 'I'his is a misfortune I have not now to complain of; — many and va- rious are the cases a short interval has i)rougbt vvi-hin my c.^re or ooservalion — alike in their sympfoms, hcnvever dif- ferent their circumstances-— and variable the event of suc- cess or disapp')intinent. But if experience has taught me, that in particular instances the medicine may prove ineffi- cacious, and must, where the, ravages of the malady are great and expensive, yet I had almost universally the satis- faction of discovering its efficacv, wherever tiic cancerous mass was not verv much enlarged : and even wbtn this was the case, instances \\ ere not wanting of a perfect recovery, and seldom indeed did it happen that the disease was unal- leviated by the medicine," It is no small compliment to the author, that his pro- posed remedy has l>eeu pretty iienerally adopted bv many of the mo?t eniinent of the London faculty, and that this adoption is becoming d.ady mora treneral. The plan pursuedin the arrangement of the work is as follows : Ist. A detail of the most remarkable cases within the author';? knowledge, — These are subdivided into such as U'ere cur<^d by iron — such as were alleviated^ and such as i^ere neither cured nor alleviated. 2d. 'I'he opinions of the ancients and moderns concern- iiis cancer. 3d. Coitsideration ')f the nature of cancer. E 2 4th. ^8 Notices respecting New Booh, 4th. Treatment of cancer. These arc fbllowed by some miscellaneous remarlcs on the predisposition to cancer, and its connexion with other diseases ; and an attempt to answer the queries of the so- ciety formed in London for the cure of cancer. The cases of cancer cured by preparations of iron amount to 50, all well authenticated; and many of them tom- municatcd to the auihor from various respectable sources. The number alleviated is eleven, and those in which the remedy pniduced no good effects are seven. We shaij pass over the account of the ancient opinions concerning cancer, and even ot the moderns. Of the lat- ter our auihor remarks : " Theories founded on such uncertain arguirients scarcely ileserve attention, only that they prove how frequently the symptoms of this disorder have given the notion of its pro- duction by the action of living animals. They seem to have nearly dropped into oblivion, till revived by Dt, Adams, who supports with much ingenuity and appearance of truth, opinions peculiar to himself on this subject. As the foun- dation of this theory, he premises, that hydatids possess the simplest form in which animal life can well be sup- posed to exist; and as the experiments of Doctor Hunter only prove in ihem a contractile force, which is allowed tci be sufficient evidence of their life ; so if a similar property can he proved in the contents of a cancerous tumour^ thebr separate vitality is equally deducible. *' In cancerous breasts, he remarks, there is always found a quantity of yellow greenish fat, which is contained in cysts, these together he denominates Carcinomatous Hy- datids ; and to prove their contractile power, he directs the following experiment to be made. ' Immediately after the operation, take the amputated part, and cut it in a trans- verse, or indeed in any direction, and wherever you dis- cover this fatty appearance, you will see the surface at first Rmooth under your knife. In an instant after you will find a papillary appearance all over this yellow green surface. Each of these papillce you will find the contents of a cap- sule, the contraction of which has produced this conical figure.' ** The other observations in support of his theory chiefly tend to prove, that those parts usu.illy affected with cancer ire endued with but httle powers of life; and which there- fore we would, a priori, suppose to be best adapted for the nidus and support of beings possessirtg a separate existence. 'Among those arc the organs subservient to the preservation .Notices respecthg New Boohs* ^ of the species and not necessary to the existence of the in- dividual, as the breasts and uterus in women and the testi- cles in men, which are most succptihie of the disease at that period of hfe when they become useless, and consequently possess but a small porlion of vitality; hovvever, that the cancerous predisposition may he anticipated by injuries, which render them entirely or in part incapable of per- forming their usual functions. *' As to the scirrhous structure which forms the most considtrabie portion of cancc, and possesses somewhat the appearance of softened cartilage, he argues, that ^ if carcinoraata pass through the same stages as Dr. J. Hunter has remarked of the connnon or lymphatic hydatid, is it not probalde thai on the death of any of them suppuration will follow, and that this suppuration may expose the living hydatids in such a manner that many of them may die from not being surrounded by living animal mat- ter? To prevent this, he conceives a fuogus is formed, which incloses individuals or clusters of them in senarate conijiartmenis, so that the death of one set produces no effect on the rest.* However, the Doctor does not inforrr^ ns whether this fungus is produced by the hydatids for their own preservation, or by the surrounding parts for the pur- pose of preventincr the departure of those troublesome visi- tors ; if the latter is the case, it at least proves, that we do not always profit by the assistance of the vis medicatrix naturae. . " But when the mind rests a length of time on any fa- vourite theory^ it is too apt to seize only the evidence that may confirm, and to neMX\\ ammonia escapes in great abundance rioni cancevouiii^ as well as other malignant ulcers*.'* *^ 1 have thus," says our author, ^^ extensively consi'- dered the opinions of Dr. Adams, which, notwithstanding the objections thatoccur, appear to explain the phjenonjena of the disease mor^j satisfactorily than any that fiave yet been ofiered; and I. confess I cannot but agree with him in the fundamental part of his theory, the independent life of cancer ; but my sentiments are somewhat ditferent t'on- cerning ihe part in which that life is resident." Mr. Carmichael then proceeds to offer his opinion of cancer as a parasytic animal (a term, we believe, first used by Doctor Adams), This leads to a very interesting history of parasyiic plants and animals, which he traces through all the writings of Darwin, Willdenow, Hunter, atid several others. In the succeeding chapter the author enters more parti- cularly into the evidence of the viiaiiiv of cancer, 'i'ite first of these is, that the cancerous substance has no communi- cating vessels with the parts in which it grows, and the in- sensibility of the person in whom it finds a nidus to any injury confined to the cancerous mas?, 2d. Iliat carci- noma arises in parts naturally endued with little life, or which, from their nature, are more inclined to run into decomposition, particularly the organs in each sex subser- vient to generation, after the period is passed in which they can be used for such purposes. 3d. From the fair presump- tion that when suppuration takes place, it is not of the can- cerous subslance Itself, but of the neighbouring parts, which are stimulated to suppuration by the previous death o'i one part of the carcinomatous mass, according to a law first discovered by Mr. Hunter, that a living animal confined within the substance of another animal does not .stimulate to suppuration ; but that the same asiimal when dead sti-. mulates like any other extraneous substance. 4th. '* The origin of carcinoma first commencing in a point — the forma- tion of xiysts ill its texture, containinore than counterbalanced by the extra quantity of sul- phates of lime and magnesia in foreign salt : the latter sub- stances also exist in British salt, but generally in* much •Jess proportions, particularly the sulphate of lime. Hence Dr. H. concluded that our native salt is in every respect equal to foreign salt for the preservation of provisions^ and that Society of AntlquarUs, • Y% that tbc vulgar prejudice against it should be instantly re- tiu),ved bv everv ralional ai^d practicable means, as injurious to the coninierce and prDsperiiy of the kingdom. In the pr(^cess of manuiaciurinir, he observed that in the Nonh of Scotland, where the lire to the pans is allowed to be- come low by neglect on Sundays, a species of very strong salt has been produced in consequence, which has obtained the name of " Sunday sail," which he ihinks even more pow- erful than any foreign salt. The cause of this superiority he atiril)utes to the slowness of evaporation, which make* the grain of the salt larger. Large-grained ?alt is best for curing dry meat, as it dissolves more gradually, and always afibrdmg fresh supplies of saline moisture; small-grained, on the contrary, is best for making brine. The decrepita- tion of all salt Dr. 11. found nearly alike ; the water of crystallization being ni very small quantities, not exec, ding two or three percent, in salt dried at the usual temjrerature of :212. The fipccific gravity is i^lso vitry little ditlereni ; that of St. Ubes was 1^-08, while the British varied from 20-23 to 20- 88. In concludn?g, the author related some of the tedious and complex operations which he adopted in these researches, in order to ascertain the relative and constituent principles of the various kinds of common salt. Luna cornea, or muriate ol" silver, was one of his principal tests ; but tke experiments to detect the sulphates of magnesia ai:d of lime were tedious and complex, especially in ascertaining the presence of an annnoniacal sulphate of magnesia. Among many other curious exj)eriments by this- able operator, he ascertained the cowprzr/Y'i/i/j/of sulj;hate of soda andsulphate of magnesia in the same liquid, contrary to the chemicai axiom laid down by Mr. Kirwan. it was iu)t, however, till after two days digesting that a very small quantity of these salts was found to be partially unned, and from this experiment the author does not seem disposed to question the truth or utility of Mr. Kirwan's pos.iion in regaul. to ^alls in their natural slate. SOCIETV OF ANTiaUARIES. Some curious particulars respecting the former perquisites at the Board of Green Cloth, and the conduct of Sir Gil- bert 'I'albot, keeper of the king's plate during the reign of Wilham II f., were read. The only useful facts which thi^j paper established were, that in iormeras well as the present times, avarice, intrigue, violent passions, and love of places arid perqui>sites prevailed. '70 IJnncenH Society. — Flint Gloss. Mr. Douce exhibited to the society a French marriage token, never used as a coin, and consequently not noticed in any work on coins or medals. On the one side it bore the circular inscription " Pour Epouse," round Henrs de lys, with a D at the bottom j and on the other '* Denirs de Foy," with united hands. These tokens were formerly given in betrothing brides. JVIr. D. quoted several decrees and ceremonies relative to the performance of marriage, and among others a decree of the council of Toledo, pro- hibiting the queens of Spain to marry a second time. The Kight Hon. Sir J. Banks, Bart. President of the Iioyal Society, communicated a curious parchment roll, ex- hibiting the marks itiade on the berdcsof swans and cvgnets in all the rivers and lakes in Lincolnshire, accompanied with an account of the privileges of certain persons keeping swans in those waters, and the duties of the king's swanherd in guarding these fowls from depredation, and preventing any two persons from adopting the same figures or marks on the bills of their swans. The number of marks con- tained in the parchment roll amounted to iig, all of which were diflftrent, and confined to the small extent of the bill of the swan. The outlines were an oblong square, circular at one end, and containing dot?, notches, arrows, or such likefigures, to constitute the difference in the marks of each person's swans. Laws were enacted so late as the 1 2th of Elizabeth, for the preservation of the swans in Lincoln- shire. LIXN.?EAN SOCIETY. January l6.-^Dr. Maton, vice-president, in the chair. Head a description of some new species of plants from New Holland, by Edward Rudge, esq., F.L.S. Part of a paper Uy William Spence, es(j., F.L.S , was also read, on a ge- nus of insects named Choleva by Latrci.llc, with a descrip- tion of eighteen British species, which was prefaced bv feome remarks on the comparative merits of the different eysiems of entomolojzv. XL Intelligence and Miscellaneous Aitichs, FLINT GLASS. X HE French artists still continue their exertions to manu«^ J'acture flint glass to rival if possible that of this country. In our 33d volume we gave a report of a committee aj)- pointed by the French Institute to examine some attempts of Mernia, 7? of this kind made by a M. Donfourgerai^. A similar re- port has been recently published by the Institute on a spe- cimen of flint glass presented by Messrs. Kraines and Lan^on. It is described as of great purity, and totally de- void of strire : its specilic gravity is to that of the English flint glass as 37 to 33 : dispersive powers very great, being as 5 to 2 with common glass, while the proportion of com- mon glass to flint glass is 2 to 3. Its refraction being descrii)ed as very strong, the foci of the glasses made with this glass are one-fourth shorter than common glass. M. Delambre informs the Institute that he has made ex- periments with an -achromatic glass of the above mate- rials, and pronounces it to be far superior to a telescope of equal size ujade by Dollond. HERNIA. ]\\ a recent foreign journal the following new remedy for hernia has been proposed by a M. G. Tarenne : — ■ " The author of this proposal has made a number of cxperinients on snails, and on ihe singular properties of their slimy juice, which has for a long time been used with success in disorders of the breast. The viscidity of this juice, its astringent virtue, and its reproductive faculty, in- duced him to suppose, that when applied externally in cer- tain infirmities it would easily penetrate the skin, and spread itself throughout the part affected. He presumed that this juice would in some way close hernial openings ; and to assure himself of this property he undertook the care of several persons afilicted with hernia. He had the happiness to succeed in curing them radically in the space of three months. ** This discovery appearing to him too important to be kept secret, he did not hesitate to publish it. We are obliged here to abridge his manner of proceeding, and refer our readers to the work published by M. Tarenne, entitled- * Cochlioperie ; Recueil d 'Experiences tres-curieuses sur Ics Helices terrestres, ou Escargot/ Sec. 1 vol. Svo. Paris,. 1808. ** The first thing necessary Is to be assured of the na- ture of the hernia by consulting some experienced surgeon. If the ruptured part cannot be returned by any means, or if it is dangerous^ to confine it in the body, this specific must not be made use of, as it would in this case only augment the evil. " A truss is then to be made, having the ball at the end Concave instead of convex, as is usual, to receive a kind of /^ Ihrnia, cup of an equal diameter with that of the orifice of the hernia. This cup may bt of porcelain, earthenware, or glass, in order that ttie liquor wiiich it is to contain may not penetrate it, nor lose any of iis viitue, nor undergo anv aheration. 'J Ije educs of this cup arc widened a little, that they may not incommode the patient when it is placed in the truss. It is to be filled with wool, which must b(i .changed every other day. " About two, three, or four hundred snails, according to the size, are then to be procured, and kept in a place where ihey may derive nutriment, because only two or three are l^sed everv day, or six or eight if they are small. They are more easily procured, and of a better quality, in spring-, which is the most favourable season for this business. *' The patient every day before he rises, and after be is in bed, takes away the cup from the truss, and with a pin wounds the snail at intervals in different places. From each wound the snail gives out, through theopenine: in his shell, sometimes a blueish sometimes a gray- coloured water, which must be caught on the wool in the cup. If the snaii onlv gives out a thick froth, it must be thrown aside and another taken insteatl. " TItc cup being sufficiently filled with liquor is to be placed on the part affected, always very exactly in the same situation ; it is then to be covered with a while linen cloth, and apply on it the ball- of the truss. This truss, without being too tight, must be sufficiently so to prevent the fluid from escaping between the edge of the cup and the skin in any posture. ^* During this treatment, which will last three or four months or more, the patient need not be kept to any par- ticular regimen. 'J'he oi\ly precautions necessary, are to fhav^ the part once every four davfi, and never to leave tlie hernia lone; uncovered, m order to avoid cold. To press more or less with the hand on the truss wb.cncver the pa- tient is going to cough or sneeze, or make any effort what- ever. If the cup rubs ofi' the akin on account of being badly made, or on account of the hair being suffered to grow too long, this treatment must be suspended until the skin is well again. In this case the patient will take away the truss altogether, if it can be done without the intestines escaping through the opening ; this wili depend on the position in which he is accustomed to lie in his bed. Du- ring the day he will wear the truss dry, by filling the concar viiv w'ith wool and putting a bit of cloth on the hernia. *' By this kiud of treataient a conniHiii hernia niay be cured Lectures, -^Patents, 7a pnred in three or,- at most, four months, unless somethiMg eise ails the patient which tends to prevent the aperture from closing. The cure will he found complete when, hy' app^ying the finger to the place, we find it closed or almost closed. ** Although the aperture be closed, it will be proper for the patient to continue wearing his truss six weeks or tw and other particular* may be learnt at the respective hospitals. LIST OF. PATENTS FOR NEW INVENTIONS. To William Cotton of Linichouse, manufiicrurcr, for a new and improved mevhod of regulatinu; the texture of all kmds of cloih in the procesS{)f weaving. — Jan. 15, 1810. To William Murdock of Soho Foundry, in the- county of StaiVord, engineer, for a process for boring and fornnng pipes, cyluulers, columns, and circular dib*ks out of solid blocks and slabs of stqne of any kiud or description. — January 1,5, METEORO- to Meteorology* meteorological tablb, By Mr. Carev, of the Strand, For Jamiary 1810. Davs of the Month. Thermometer. P 5 ^ bi) r ( U) u u • 'C4 ~ u ITeieht of u_ , 1 E the B^iom^ ij form us, that "if a good eyp vie^vs an object at the least distance it can be seen .distiiictly, and then at twice that distance, and then at an infinite distance, there is about the same alteration made in the figure of the eye between the two last cases, as there^ is between the two first. "ForletBCDE (PI. IT ) be tiie axis of the eye infinitely produced ; B C, B D, BE, the three distances of the pb; }ect from the cornea AB; and C A, DA, EA', thret? rays falling upon any given pyji^, of ll^!^^^cpr»qa j ^V^^^eof ^'^ - is parallel to the axis. - ^ , \ .,,: .,,;,».'• .,'/ * ^Jf^: ••^ Now to produce distinct .vision of the points G, D,.E; it is plain that every one of the rays C A, DA, E A, miist be successively refracted to the same point F, upon the re- tina, where it is cut by the eve\,j||cis, ■ At first let us sup- Kcj F'3'" ■ ' pose , 64 On the Adjustment of the Eye to see pose the point F to be given, or the length of the axis B F to be imiputable, and tnen the quantity of the refraction of each ray must be varied. And because the distance CD is supposed equal to C B, or C A, the angle C A D is equal to C D A, and consequently to DAE. Therefore, con- ceiving each ray to come back again from the fixed point F, to the points C, D, E, successively ; the whole quantity of its refractions must first be lessened by the angle CAD, and then by the equal angle DAE; and so the changes of the figures of the refracting surfaces must be much the same when the object is removed from C to D, as when it is removed from D to E*." Hence it may be demonstrated, that objects at various distances, as C, D, and E, may be seen distinctly with- out any alteration in the humours of the eye, or in its out- ward form, 1. It has been proved in a former paper f, that when a good eye views an object at the least distance it can be seen distinctly, the rays w^hich enter the pupil are parallel, or such as differ very little from being so; whence it is evi- dent, that the rays from the object C falling upon the eye at B are parallel. 2. Rays issuing from the object E, a planet or a star, at an infinite distance are parallel, consequently the angle DA E is infinitely small: and 3. As the angle CD A is equal to the angle DAE, the angle CD A is infinitely small ; therefore the line DA co- incides with the line DB, and the rays falling upon the eye from D must also be parallel ; consequently the rayt from the object D, and also those from E and C, are re- fracted to the same point F upon the retina : for parallel rays falling upon the eye near the axis of vision have the same focus, whether they come from objects that are near or remote. Whence it is evident that vision perfectly di- stinct is produced only by parallel rays ; but the means by which the eye admits such rays only as are parallel, or nearly so, and rejects the rest, come next to be considered. III. — If a small circular object be viewed with too large a pupil, which may be done by placing the object much within the limits of distinct vision, it will appear larger than perfect vision would represent it, by a penumbra of light, which is called the circle of dissipation. Now if the pupil be contracted, by means of a perfora- * Smith's Opticf, Remarks, p. 2. I Philosophical Magazine, vol, xxix. p. 342. - tioB Oljects distinctly at different Distances, 85 tion made in a card of such magnitude as to prevent the lateral rays from entering the eye, the object will appear distinct. But if the aperture in the card be made as large as the pupil, the circle of dissipation will appear as large as before. This circle of dissipation is formed by those rays which enter the eye remote from the axis of the crystalHne lens. Thus, when the pupil is too large for distinct vision, the most refrangible of those side rays will cross one another in the vitreous humour, and, by falling upon the retina in a diverging state, will be disperses! over a larger space than the true image, and consequently form a penumbra round it ; and the least refrangible rays of the same pencil will be dispersed over the interior parts of the circle ; whence that indistinctness of vision which is experienced by people ad- vanced in years. No writer has paid more attention to the theory of distinct and indistinct vision than Dr. Jurin. This philosopher says, that '' the radius of dissipation is, cofteris paribus, always proportional to the radius of the pupil. Consequently, when the pupil is narrow, the radius of dissipation and the penumbra arising from the dissipation will be smaller, that IS, vision will be rendered either distinct, or at least less indistinct than it would otherwise be*." IV. — Many philosophers have maintained that we have the power of viewing objects at different distances, by a conformation of the eye for this purpose, independent of a variation in the pupil; but they vary much in their opi- nions respecting the means by which this effect is pro- duced. Dr. Matthew Young says, that " the power of seeing distinctly at diff*erent distances t5t^ of the eye decav or shrink by old age, which causes the eye of the short-sighted to grow flatter till it comes to a due figure. For short-sighted men see remote objects best in old age*. And this opinion has been adopted by some of our best writers on the theory of vision. But let opinions give place to facts. a .m. Mr. Adams says, *^ It is generally supposed,' thai 'the short-sighted become less so as they advance in years, as the natural shrinking and decay in the humours of the eye lessen its convexity, and thus adapt it bettcrfor viewing distant objects : but among the great number of short- sighted that I have accommodated with glasses, I have ever found the reverse of this theory to be trae, and the eyes of ■the myopes never required glasses less concave, but gene- rally more concave, as they grew older, to enable them to see at the same distance f." Hence it is evident, that the humours of the eyes of the short-sighted undergo no change as they grow older, and that visi'on generally becomes less perfect. For, as the iris )oses some part of its. contracting power w^th age, the pu- *' Sec Newton's Opti'cs, p.'lS. I Adams on Vision, p. 126.'" — pil Onanative ArseniateofLead, Bf pil becomes larger, the circle of dissipation increases, and consequently remote objects appear less distinct than they = did in tlie early part of life. '. ri VI.— From this investigation it manifestly appears, tl^at the eye is in reality no more than a michine of a fixed and., determinate form, without any power to alter iis outward^ dimensions, or to move any of its internal humours ; and'- that the only adjustment necessary to form a distinct pic- ! ture of an object upon the retina (whether the object be ^ near or remote) is to prevent diverging ray^ from entering' the eye, and to admit such onlv as are nearly parallel. , ' This office is performed by the iris, which contracts th« pupil to exclude the side rays when we view near objects, and enlarges this aperture to give us a distinct view Qf such remote objects as are but faintly illuminated: it is also well known, that whenever the eye is exposed to a strong light, the pupil contracts, but it expands as the light de- creases. These contractions and dilatations of the pupil, according ' to the distances of objects and strength of light in which they are seen, are directed bv that volition of the mind which presides over and regulates all the other motions of the eye. Ez, Walker, Lynn, Januarys, 1810. • XIV. On a native Arsenmte of Lead, By the Reverend William Gkegor Comrmmicated by Charles Hat-" CHET, Esq,, F.jR.S.* I. JL hat the oxide of lead and the arsenic acid might be found in the state of natural combination, is a supposirioa highly probable, from the strong affinity which subsists, between these two substances. But the existence of such a compound has not, as I conceive, hitherto been established.' by such proofs, as entitle it to be ranked amongst the der-, cided cases of mineralogical science. I trust, thereforCj,, that the observations, which I have the honour of sjibmit- , ting to the Socie y, on a new f ore of lead lately discovered * From Philosophical Transactions for 1809, Part II. f It isnevv at least to the miners in Cornwall; nor was there, previously to this discovery, any are resembling it to be found in that splendid collec- tion of minerals, which my valuable friend Philip Rashleigh, esq., has fo liberally formed, and as liberally employed in th« promotion of science. I' 4 i;^ 6^ On a native Arsenlate of Lead. \n the county of Cornwall, so justly celebrated as well for the variety as for the richness of its mineral productions, will not be deemed superfluous. This mineral was raised in the mine called Huel-Unity^ a very rich copper mine, in the parish of Gwennap. Ac- cording to the information with which 1 have been favoured by Mr. William Davy, c. very intelligent and experienced miner in that district, it was found in a lode south of Muel- Unity principal lode, at the depth of fifty fathoms below the surface, which lode underlay about two feet in the fathom south : at the depth above mentioned, this lode fell in or formed a junction with another small lode or vein to the south, and when the junction look place this lead ore was found. The veins of it are, in general, from six to ten inches wide, and they diverge on going west. Some particles of this lead ore have been found in tlie southern part, after tha separation of the lodes ; but the northern lode does not contain any until the junction takes place. This ore is intermixed with some native copper, very rich gray copper, and black copper ore, and some is mixed with quartz. The walls of both veins are killas. II. Description, Tliis mineral is regularly crystallized. The form of its most perfect crystals is an hexahedral prism , they are of different sizes, from one-tenth of an inch in diameter to the size of a hair. The longest which I have seen do not exceed three-tenths of an inch in length : these terminate in a plane, at right angles, with the axis of the prism ; but the crystals of a smaller size are frequently drawn out into a very taper acumination, which appears to be a six-sided pyramid. A number of smaller crystals are often closely packed together in bundles, which are bent in different di- rections, and terminate in a point. The larger crystals cither stand alone, or adhere, on their lateral planes, to the gangue, or are confusedly matted together in a mass. Some of them are hollow, as if an internal nucleus had been destroyed ; and sometimes this internal nucleus over- tops the external laminae. The gangue is a white quartz, which frequently exhibits on its surface the appearance of a partial decomposition. The red octahedral copper ore, and the copper into which that ore passes, are often intermingled with the crystals of this lead ore and imbedded in them. The colour of these crystals consists of a variety of tints of yellow. Some are of a beautiful wine yellow resembling the On a native Arseniate of Lead. Qg the Brazilian topaz : this, in the greater nuinher of speci- mens, passes into a delicate Isabella- colour : whilst, in other cases, we have the honey -yellow mingled with brown hues ot'difTcrent intensities : so tliat we meet with crystals re- sembling dark brown sugar-candy, or common resin. Some of the crystals are beautifully transparent, whilst others possess this quality in part only, at their extremities, or in inferior degrees throughout their whole lengths. The external lustre, in some specimens, is vitreous; in others, resinous : but in some instances their surface is partially covered by tender and delicate filaments of a silky lustre. These filaments are sometimes found in a separate state loosely adhering to quartz ; and they form a variety of this fossil. The crystals vary as to hardne^js. The angular frag- ments of the most transparent are sufficiently hard to scratch ^^f^\ ...» This mineral is easily reduced to powder, which has the appearance of pounded resin ; it contracts a yellower tint by long exposure to the air. The specific gravity of the purest crystals, taken at the temperature of 50° Fahrenheit, was 6*4 1. in. A fragment of crysta), exposed to the flame of the blow- pipe in a gold spoon, melted into a brownish-vellow mass, which on cooling did not assume any angular figure. It remained in a state of ignition apparently unaliered; but when a piece of it was exposed to the flame on charcoal, a rapid decomposition took place, arsenical vapours were ex- tricated, and globules of a metal, possessing the common properties of lead, were left behind. This mineral, in a state of fine powder, is soluble in nitric acid, even without the aid of heat. Care, however, must be taken, that it does not concrete into lumps. The vessel therefore which contains it must be frequently shaken, and the nitrate of lead produced must be, from time to lime, dissolved in water, and poured oft^ froni the residuum. The process of solution is, however, accelerated bv a di- gesting heat. Some silica remains, which, as the (juantity of it is variable according to circumstances, appears not to be an essential inoredicnt of this fossil. The nitric solution is colourless; its transparency is not disturbed by nitrate of barytes. Nitrate of silver renders it turbid, and a small quantity of white curdly matter is de- posited. Sulphuric acid and the liquid sulphates produce copious OO Oil a native Arseniuie of Lead, copious precipitates of a white heavy matter. If the fluid be poured off* from this subsided matter, and it be freed fn^m the superfluous sulphuric acid, by the means of nitrate of barytes, it will yield, on the affusion of liquid nitrate of lead, an abundant white precipitate, which, urged by the flame of the blow-pipe on a support oF charcoal, resolves itself into reduced lead and arsenical vapours. These preliminary experiments led me to the probable conclusion, that this fossil. chiefly consisted of oxide of lead, ilrsenic acid, and a small quantity of the muriatic acid. IV. Analysis, A, 1. Fifty grains, carefully selected from crystals of a pale Isabella-colour, were reduced to a fine powder, and exposed to a low red heat for about an hour. Their weight was di- minished by 0*15 of a grain. 2. The yellowish powder was now transferred to a vessel of pure silver, and mixed with a lixivium containing fifty grains of potash, prepared by the means of alcohol ; a quan- tity, which 1 had previously ascertained to be sufficient to effect a complete decomposition of this mineral. The ley was gradually evaporated to dryness in a sand-bath. The soluble part was extracted by distilled water, and poured off from a yellowish white matter, which was sufficiently edul- corated (a). 3. Liquid nitrate of ammonia was now dropped into the alkaline fluid, as long as it produced any cloudiness : the clear fluid was now decanted from a small quantity of white matter, which had subsided, and rendered acid by nitric acid; ammonia, added to excess, produced a slight turbid- ness. These precipitates, after sufficient edulcoration, were added to the yellowish white residuum (a). 4. The liquid was now rendered slightly acid by nitric acid, and a solution of nitrate* of lead in distilled water was dropped into it, as long as it separated any precipitate. The clear fluid was poured off, and evaporated nearly to dryness, and a small quantity of white matter, thus ob- tained, was added to the former precipitate, which dried, • If the colourless liquid oxy-nttrate of lead be .dropped into a dilute so- lution of arsenic acid, or of arseniate of potash acidulated by nitric acid, no immediate precipitation of an arseniate of lead is produced; but crystalline grains are, after a time, gradually deposited at the bottom of the vessel. But liquid nitrate of lead causes an immediate and abundant precipitate from these same dilute solutions. These two combinations therefore must be ♦iilferent. and, On a native Arseniate of Lead, gi and exposed to a low red heat, weighed, whilst still warm, 40'8, which, according to the proportion of 33 : 100, esta- bhshed by Mr. Chenevix, implies 13*46 of arsenic acid, f' 5. The superfluous lead was now separated from the fluid by sulphate of soda, and filtered off. Ammonia precipi- tated a minule portion of flaky matter ; it weighed, after ignition, 0*2 of a grain; it consisted of silica and oxide of lead, and must be attributed tb the nitrate of lead employed. B. 1. The yellowish white residuum (a) (A, §2.) was dis- solved without efl'ervescencc iii nitric acid, except a minute portion oF silica, whicn, afier ignition, = 0* 8, A white heavy maUer Was thrown down from this solution, by -liquid sulphate of soda. The clear decanted fluid was eva- porated to a small volume, and sulphate ot soda produced a further separation of white matter ; it was sulphate of lead, which, after exposure to a low red heat, and weifrhed, whilst warm, = 47'<5, whic4i, upon the supposition that cue himdred parts of sulphate of lead contain 69*74 of lead + 3*48 of oxyv::;en, is equivalent to 34*77 of oxide of lead, 2. The fluid, now frted from lead, deposited, oai the affu- sion of ^mmonia, a greenish matter, which, after ignition, became red, and = 0*033 of a grain. It was oxide of iron. ■ 1. One hundred grains of larger crystals, some of which were liollow, aild the surfaces of which were slightly and pdrtially covered with silky filametits, treated in the same way yielded 95*283 of sulphate ot lead, equivalent to 6Q'7Q *oF oxide, and 80 of arseniate of lead, which indicates 26*40 Vif arseiiic acid. The oxide of iron, in this case, amounted *to only '05 of a grain, and the residuary silica was in too small a quantity to be weighed. 2. I have endeavoured to decompose this fossil by boiling it to dryness in a solution of four times its weight of the purest subcarbonate of potash, and exposing the dry mass, for a very short time, to a low red heat ; but I found, that only a part of the arsenic acid had united to the alkali ; the larger portion of it was detected in the nitric solution of the residuum ; but the relative proportions of the oxide and the acid, were found to correspond almost exactly with the foregoing statement of them. 3. I found ako, that carboilafe of amrnonia precipitated' jthis mineral^ in an unaltered slate, from its solution in nitric ^ On a native Arsmiate of Lead, nitric acid : as no arsenic acid bad united with the precipi- tant. The solution of I he nitrate of ammonia was evapo- rated to dryness, and exposed to a red heat in a platina crucible ; but nothing was left, except a shght trace of oxide of lead. Wc may infer from hence, the absence of both the fixed alkaHes. 4. I found in one specimen only of this fos&il any no- table diti'erence in the relative proportions of the oxide of lead and of the acid to which it is united. It consisted of crystals confusedly matted together in a more compact mass than this fossil generally assumes. One hundred grains were dissolved in nitric acid ; the marine acid was separated by nitrate of silver, and any redundant silver by muriate of ammonia. The lead was separated by sulphuric acid, and the superfluous portion of that acid by nitrate of barytes, and the arsenic acid was combined with the oxide of lead by the affusion of nitrate of lead. The muriate of silver = 9*8; the sulphate of lead = 97*6, and the arseniate of lead = 72, equivalent to 1*63 of muriatic acid, 71*46 of oxide of lead, and 23*88 of arsenic acid, respectively. The quartz = 0*35, and the oxide of iron 0*2, nearly. Another portion taken from the same specimen, treated with an alkali, gave very nearly a similar result. D. It will now be necessary for me to speak concerning an ingredient of this fossil, which I may have seemed to over- look. I mean the muriatic acid : I have found some diffi- culty in ascertaining the proportion which it bears to the other constituent parts, and from a cause which I did not suspect. I considered that the only sure mode of deter- mining this point, was to have recourse to nitrate of silver, which might effect a direct separation of the marine acid from the nitric solution of this fossil. But I found, in many experiments upon given quantities of this mineral, that the results, which I derived from this most valuable chemical test, were variable and uncertain. At last, I was enabled to trace the error and uncertainly up to two sources. In the first place, I found that the mu- riate of silver was more abundant in the cases where I employed a vessel v^-ith a long neck for the solution, and did not expose it to heat. I concluded, therefore, that when the process was con- ducted under different circumstances, the predominating mass \ On a native Arseniate of Lead, 93 mass of nitric acid produced its effect, and volatilized a portion of the niuriatic. Another source of error I found in the following anoma- lous circumstance, viz. a simultaneous precipitation of a portion of arseniate of lead takes place with that of the mu- riate of silver. Whatever combination this may be, it is a weak one, and may be severed by nitric acid, which dis- solves the arseniate and leaves the muriate ; or by ammonia, which takes up the muriate, to the exclusion of the arseniate. The conclusion to which many experiments have led me is this, that the muriate of silver produced in the nitric so- lution of one hundred grains of arseniate of lead by nitrate of silver, amounts to about 9'5. E. In order to prove that the acid, which is combined with the oxide of lead in^ this mineral, is the arsenic acid, and that it is not combined with phosphoric, I decomposed some of its acid, which had been combined with lead in ihe foregoing experiments, by means of sulphuric acid, and filtered off the sulphate of lead. The fluid which passed through the filter v\ as evaporated nearly to dryness, and it assumed the appearance ot cryslalline grains. Some of it was exposed to the flame of the blow-pipe in a gold spoon ; at first it became like a white dry powder, which melted before an increased heat : placed on charcoal and ignited, ii was totally dissipated in arsenical fumes. Some of it was dissolved in water, and, dropped into liquid sulphate of tilanium, a white precipitate was pro- duced : combined with soda, it precipitated silver from. the nitrate of silver, of a brick colour. It precipitated mer- cury from its nitrate, of a yellowish colour, which after- wards became reddish. This precipitate, exposed to the flame of the blow-pipe on charcoal, exhibited the same phcenomena as arseniate of mercury. I precipitated magnesia from its muriate, and redissolved it by carbonate of ammonia, perfectly saturated with car- bonic acid. I divided this liquid into two portions, and dropped into both a solution of the combination of the acid of this mineral and ,!^oda. No precipitate was produced. I dropped into one of the vessels some liquid phosphate of soda, and a separation of saline matter was instantly pro- duced. I soon, however, found, that this mode of di- stinguishing the phosphoric from the arsenic acid could not be depended upon. For in the other vessel, in which no phosphate of soda had been dropped, in a short lime, saline tufti ^4 Description of a refieciive Goniometer, tufts made their appearance, and an abundant deposition of saline matter was formed. I found also, that if the solu- tioa had been more concentrated, the precipitation would have immediately taken place. On making a comparative experiment with arsenic acid, I found that it forms a triple salt with ammonia and mag- nesia, analogous to the phosphoric salt described by Dr. Wollaston. The figure of the arsenical salt, as far as I could determine it from a confused crystallization, is a trihedral prism. We are therefore, I think, authorized from the experi- ments herein detailed, to conclude, that the fossil which is the subject of this paper is an arseniate of lead, and that, if we state that the relative proportion of the constituent parts of it is in one hundred, as follows, we shall not be far from the truth : Oxide of lead - 6976 Arsenic acid - 26*40 Muriatic acid - 1'5S The silica and the oxide of iron, which account for a portion of the loss, and the alumina and copper which are sometimes found in an analysis of this fossil, 1 do not con- ceive to be essential to it. The existence of a minute portion of muriatic acid as a constant ingredient of it, is a curious fact: and it is still more curious, when we consider it in connexion with the analogy that, in this particular, it maintains with the natural phosphates of lead. XV. Description, of a reflective Goniometer, By William HyDE Wollaston, M.D,, Sec, i?.S.* X* ROM the advances that have been made of late years In crystallography, a very large proportion of mineral sub- stances may now be recognized, if we can ascertain the angular dimensions of their external forms, or the relative position of those surfaces that are exposed by fracture. But though the modifications of tetrahedrons, of cubes, and of those other regular solids, to which the adventitious aid of geometry could be correctly applied, have been determined with the utmost precision, yet it has been often a subject of regret, that our instrurrjLUts for measuring the angles of crystals are not possessed of equal accuracy, and that Iii applying the goniometer to small crystals, where the radius «^- From Philosophical Traa»actions for 1809, Part II. IB Description of a reflective Goniometer, 9 J in contact with the surface is necessariW very short, the measures, even when taken with a steady hand, will often deviate too much from the truth to aid us in determining the species to which a suhstance belongs. A means of remedying this defect has lately occurred to me, by which in most cases the inclination of surfaces may^ be measured as exactly as is wanted for common purposes; and when the surfaces are sufficiently smooth to reflect a distinct image of distant objects, the position effaces only ^th of an inch in breadth may be determined with as much, precision as those of any larger crystals. For this purpose, the ray of light reflected from the sur- face is employed as radius, instead of the surface itself, and accordingly for a radius of -^'^th of an inch, we may sub- stitute either the distance of the eye from the crystal, which would naturally be about twelve or fifteen inches ; or for greater accuracy we may, by a second mode, substitute the distance of objects seen at a hundred or more yards from us. The instrument which I use, consists of a circle gradu- ated on its edge, and mounted on a horizontal axle, sup- ported by an upright pillar (Plate II). This axle being perforated, admits the passage of a smaller axle through it, to which any crystal of moderate size may be attached by a piece of wax, with its edge, or intersection of the surfaces,, horizontal and parallel to the axis of motion. This position of the crystal is first adjusted, so that by turning the smaller axle, each of the two surfaces, whose inclination is to be measured, will reflect the same light to the eye. The circle is then set to zero, or ISO^, by an index at- tached to the pillar that supports it. The small axle is then turned till the further surface re- flects the light of a candle, or other definite object, to the eye; and lastly, (the eye being kept steadily in the same place) the circle is turned by its larger axle, till the second surface reflects the same light. This second surface is thus ascertained to be in the same position as the former surface had been. The angle through which the circle has moved, i§ in fact the supplement to the inclination of the surfaces ; but as the graduations on its margin are numbered accord- ingly in an inverted order, the angle is correctly shown by the index, without need of any computation. It may here be observed, that it is by no means neces- sary to have a clean uniform fracture for this application of the instrument to the structure of laminated substances ;• for since p6 Description of a reflective Gmiiometer, since all those small portions of a shattered surface^ that are parallel to one another (though not in the same plane), glisten at once with the same light, the angle of an irregfu- lar fracture may be determined nearly as well, as when the reflecting fragments are actually in the same plane. In this method of taking the measure of an angle, when the eye and candle are only ten or twelve inches distant, a small error may arise from parallax, if the intersection of the planes or edge of the crystal be not accurately in a line with the axis of motion *; but such an error may be ren- dered insensible, even in that mode of using the instru- ment, by due care in placing the crystal ; and when the surfaces are sufficiently smooth to reflect a distinct image of objects, all error from the same source may be entirely obviated by another method of using it. For this purpose, if the eye be brought within about an inch of the reflecting surface, the reflected image of some distant chimney may be seen inverted beneath its true place, and by turning the small axle may be brought to correspond apparently with the bottom of the house (or with some otljer distant horizontal line). In this position the surface accurately bisects the angle, which the height of that house subtends at the eye (or rather at the reflecting surface) ; then, by turning the whole circle and crystal together, the other surface, however small, may be brought exactly into the same position ; and the angle of the surfaces may thus be measured, with a degree of precision which has not hitherto been expected in goniometry. The accuriicy, indeed, of this instrument is such, that a circle of moderate dimensions, with a vernier adapted to it, will probably aiford corrections to many former observa- tions. J have, already remarked one instance of a mistake that prevails respecting the common carbonate of lime, and I am induced to mention it, because this substance is very likely to be employed as a test of the correctness of such a goniometer, by any one who is not convinced of it» accuracy from a distinct conception of the principles of its construction. The inclination of the surfaces of a primitive crystal of carbonate of lime is stated, with great appearance of pre- * I cannot omit mentioning, that Mr. Sov/erby had thought of employin;^ reflection for ihis purpose, nearly at the same lime as myself; but did noE j*iicceed to his satisfaction, in conseijuence ot an attempt to fix the positiou of the eye. For when the line of siglit u determined by a point connected ■with the apparatus, the radius employed is thereby limited to the extent of xhd insuumeut, and the error from parallax is manifestly increased. cision. Description of a reflective Qoniomeicr, 97 cision, to be 104° 28' 40'' : a result deduced from the sup- posed posuion Oi its axis at an angle of 43^ with each of the surfaces, and from other seducing circumstances of appa* rent harmony hv simple ratios. But however strong the presumption might he that this angle, which by measure- ment aj)proaches to45*', is actually so, it must nevertheless be in fact about 45° 20'; for I find the inclination of the surfaces to each other is very nearly, if not accurately, 103^, as it was formerly determined to be byHuygens*; and since the measure of the superficial angle given by Sir Isaac JsTcwton t corresponds with this determination of Huygcns, his evidence may be considered as a further confirmation of Ihc same result ; for it may be presumed, that he would not adopt ih& measures of others, without a carefql examina- tion. IN THE ANNEXED PLATE, ab. Is the principal circle of the goniometer graduated on its cdgQ. c c. The axle of the circle, d. A milled head by which the circle is turned. ee. The small axle for turning the crystal, without mov* ing the circle. f A milled head on the small axle. g, A brass plate supported by the pillar, and graduated SLS a vernier to every five minutes. /z. The extremity of a small spring, by which the circle is stopped at 180**, without the trouble of reading off. a and k k. Are two centres of motion, the one horizon* tal, the other vertical for adjusting the position of a crystal : one turned by the handle /, the other by the milled head m* The crystal being attached to a screw-head at the point n (in the centre of all the motions), with one of its surfaces as nearly parallel as may be to the milled head w, is next rendered truly parallel to the axis by turning the handle I till the reflected image of a horizontal line is seen to be ho- rizontal. By means of the milled heady", the second surface is then brought into the position of the first; and if the reflected image from this surface is found not to be horizontal, it is rendered so by turning the milled head tn ; and since this motion is parallel to the fir^t surface, it does not derange the preceding adjustment. * Huygenii Opera Rdi(jua, torn. i. p. 73. — Tract, de Limine. f Newton'i Optics, 8vo. p. 329. Qu, 25, concerning Iceland Crystal, Vol.35. No. 142. Feb. 1810, G XVI. O** [ 98 ] XVI. Chemical Analysis of a Black Sand, from the River Dee, in Aberdeenshire* By Thomas Thomson, JW.D., Lecture^' on Chemistry , Edinlurgh*. JL HE specimen which formed the subject of the first of the following analyses was brought from the banks of the river Dorr, about seven years ago, by my friend Mr. James Mill, who at that time resided in Aberdeenshire. By him I was informed that considerable quantities of it are found in different parts of the bed- of that river, — that it is called by the inhabitants iron-sand, — and that they use it for sanding newly written paper. I tried some experiments in the year 1 800, in order to ascertain its nature ; but was too little skilled at that time, both in mineralogy and prac- tical chemistry, to manage an analysis of any considerable difficulty. The black powder is mixed with a good many small whitish, reddish, and brownish grains, which, when ex- amined by means of a glass, prove to be pieces of quartz, felspar, and mica. From this it would appear, that the sand of the river Dee consists chiefly of the detritus of gra- nite or gneiss. When a magnet is passed over the sand, some of the black grains adhere to it, and are by this means easily ob- tained separate. But after all that can be attracted by the magnet is removed, the greater part of the black powder still remains. This residue is indeed attracted by a power- ful magnet, but so very feebly, that it is not possible by means of it to separate it from the grains of sand with which it is mixed. Thus we learn, that the black matter consists of two distinct substances ; one of which is power- fully attracted by the magnet, the other not. As this se- cond substance was obviously specifically heavier than the grains of sand with which it was mixed, I placed a c^uan" tity of the powder on an inclined plane, and by exposmg it cautiously, and repeatedly, to a jet of water, T succeeded in washing away most of the grains of sand> and thus ob- tained it in a state of tolerable purity. The first of these minerals we may call iron-sand, and the second iserine, as they belong to mineral species which oryctognosts have distinguished by th^se names, I. Iron-Sand, The iron sand is much smaller in quantity than the ise- • From Trai»4?tioji8 of Royal Society, Ediuburghj 1807, rine. Analysis of a Black Sandjrom the River T e, 99 fine, and does not exceed one- fourth of the mixture at most. Its colour is iron-black. It is in very small angu- lar grains, commonly pretty sharp-edged, and sometimes having the shape of imperfect octahedrons. The surface is rough; the lustre is feebly glimmering and metallic; the fracture, from the smallness of the grains, could not be accurately ascertained, but it seemed to be conchoidal, Opake, semi-hard, brittle, easily rciduced to powder. Pow- der has a grayish -black colour ; powerfully attracted by the magnet ; specific gravity 4*765. 1. As acids were not found to act upon this mineral, 100 grains of it were reduced to a fine powder, mixed with twice its weight of carbonate of potash, and exposed for two hours to a red heat in a porcelain crucible. The mass, being softened in water, was digested in muriatic acid. By repeating this process twice, the whole was dissolved in muriatic acid, except a brownish-white matter, which being dried in the open air weighed 19|- grains. 2. The muriatic acid solution, which had a deep yellow- ish-brown colour, was concentrated almost to dryness, and then diluted with water. It assumed a milky appearance; but nothing was precipitated. Being boiled for some time, and then set aside, a curdy-like matter fell. It was of a i)]ilk-wliite colour, weighed, when dry, seven grains, and possessed the properties of oxide of titanium. 3. The residual liquid being supersaturated with am- monia^ a dark reddish-brown matter precipitated, which being separated by the filter, dried, drenched in oil, and heated to redness, assumed the appearance of a black mat- ter, strongly attracted by the magnet. It weighed 93*7 grains, and was oxide of iron* 4. The 19'5 grains of residual powder, being mixed with four times its weight of carbonate of soda, and exposed for two hours to a red heat, in a platinum crucible, and after- wards heated with muriatic acid, was all dissolved, except about a grain of blackish matter, which was set aside. .*). The muriatic solution being concentrated by evapo- ration, a little white matter was separated. It weighed one-fourth of a grain, and possessed the characters of oxide of titanium. 6. When evaporated to dryness, and redissolved in water, a white powder remained, which proved to be silica, and which, after being heated to redness, weighed one grain. 7- The watery solution being supersaturated with potash, Aud boiled for a few minutes, was thrown upon a filter, to G 2 ^ separate 100 ' Anahjsis of a Black Sand^ ceparate a reddish -brown matter, which had been precipi- tated. The clear hquid which passed through the filter was mixed with a solution of sal ammoniac. A soft white matter slowly subsided. It was alumina, and, after being heated to redness, weighed half a grain. 8. The brown -coloured matter which had been precipi- tated by the potafh, when dried upon the steam-bath, weighed 20*2 grains. It dissolved with effervescence in muriatic acid. The solution had the appearance of the yolk of an egg. When boiled for some time, and then diluted with water, it became white, and let fall a curdy precipi- tate, which weighed, when dry, 4*6 grains, and possessed the properties of oxide of titanium. 9. The residual liquor being mixed with an excess of am- monia, let fall a brown matter, which, after being dried, drenched in oil, and heated to redness, weighed six grains. It was strongly attracted by the magnet, but was of too light a colour to be pure oxide of iron. I therefore dis- solved it in muriatic acid, and placed it on the sand-bath, in a porcelain capsule. When very much concentrated by evaporation, small while needles began to make their ap- pearance in it. The addition of hot-watei made them dis- appear j but they were again formed when the liquor be- came sufficiently concentrated. These crystals, when se- parated, weighed 1'3 grains, and proved, on examination, to be white oxide of arsenic. During the solution of the six grains in muriatic acid, a portion of black matter sepa- rated. It weighed 0*2 grains, and was totally dissipated before the blow- pipe in a white smoke. Hence, it rausi have been arsenic. These 1'5 grains are equivalant to ra- ther more than one grain of metallic arsenic. Thus, it ap- pears, that the six grains contained one grain of arsenic, •which explains the whiteness of their colour. The rest was iron. It can scarcely be doubted, that the proportion of arsenic present was originally greater. Some of it must have been driven ofi' when the iron oxide was heated with oil. 10. Th« insoluble residue (No. 4.) was with great diffi- culty dissiolved in sulphuric acid. When the solution was mixed with ammonia, a white powder fell, which weighed 0*8 grains. It was accidentally lost, before I examined its properties. But I have no doubt, from its appearance, that It was oxide of titanium. 11. Thus, from the 100 grains of iron-sand, the follow* ing constituents have been extracted by analysis ; Black /roTTi the River Dee, in Alerdeenshire. ,101 Black oxide of iron, - 98*70 White oxide of titanium, 12*65 Arsenic, * - - i 'OO Silica and alunmina, - 1'30 Total, 113-85 Here there is an excess of nearly 14 grains, owing, without doubt, to the combination of oxygen with the iron and the titanium during the analysis. Had the iron in the ore been in the metallic state, the excess of weight, instead of 14, could not have been less than 30. For the black oxide is known to be a compovmd of 100 metal and 37 oxygen. Hence, I think, it follows, that the iron in our ore must have been in the state of an oxide, and that it must have contained less oxygen than black oxide of iron. A guod many trials, both on iron- sand, and on some of the other magnetic ores of iron, in- duce me to conclude, that the iron in most of them is com- bined with between 17 and 18 percent, of oxygen. This compound, hitherto almost overlooked by chemists, I con- sider as the real protoxide of iron. Thenard has lately de- monstrated the existence of an oxide intermediate between the black and the red ; so that we are now acquainted \vii]i four oxides of this metal. But the protoxide, I presume, does not combine with acids like the others. Analogy leads us to presume the existence of a fifth oxide, between the green and the red. ' As to the titanium, it is impossible to know what in- crease of weight it has sustained, because we are neither acquainted with it in the metallic state, nor know how much oxygen its different oxides contain. It is highly im- probable, that, in iron-sand, the titanium is in the metallic state, if it be made out that the iron is in that of an oxide. The experiments of Vauquelin and llecht, compared with those of Klaproth, have taught us thar there are three oxides of titanium, namely, the blue, the red, and the white. From an experiment of Vauquelin and Hecht, and from some of my own, I am disposed to consider these oxides as composed of the following proportions of metal and oxygen : Metal. Oxygen. 1. Blue, 100 \Q 2. Red, 100 33 3. White, 100 49 I find, that when the white oxide of titanium is reduced ta G3 the t02 , Analysis of a Black ^and, the state of red ox'ule, it loses one-fourth of its weight j and that red oxide, when raised to the state of while oxide, increases exactly one-third of its weight, It was the know- ledge of these facts, that led me to the preceding numbers. And I think they may be used, till some more direct expe- riment lead us to precise conclusions. Red oxide being the only state in which this metal haa yet occurred separate, we may conclude thai it combines, jn this state, with metallic oxides, and that the titanium ia iron-sand is most probably in this state. But while oxide, diminished by one-fourth, gives us the equivalent quantity of red oxide. On that supposition, the titanium present, before the analysis, in the 100 grams of ore, weighed 9*5 grains. The appearance of the arsenic surprised me a good deal, as it was altogether unexpected. I am disposed to ascribe it to some particles of arsenic pyrites which might have been accidentally present. This conjecture will appear the more probable, when we reflect, that arsenic pyrites very frequently accompanies iron-sand. Before the microscope, the iron-sand appears to contain some white shining par- ticles, which, probably, are arsenic pyrites. The small quantity of silica and alumina, I ascribe, without hesitation, to grains of quartz and felspar, which had adhered to the iron-sand, and been analysed along with *it. Some such grains were actually observed and separated.^ But others, probably, escaped detection. 12. If these suppositions be admitted as well founded, the iron-sand was composed of Protoxide of iron, 85'3 Red oxide of titanium, 9*3 Arsenic, - ro Silica and alumina, 1*5 Loss, - - 2*7 100-0 The loss will not appear excessive, if we consider, that a portion of the arsenic must have been sublimed, before the presence of that metal was suspected. Upon the whole, I think we may consider the specimen of iron-sand examined, as composed of nine parts prot- oxide of iron, and one of red oxide of titanium. The pre- sence of titanium in this ore had been already detected by Lampadius, though, as I have not seen his analysis, J cannot say in what proportion, II. Iserme^ from the River Dee, in Aberdeenshire* 103 II. Iserine, The colour of this ore is iron-black, with a shade of brown. ' It consists of small angular grains, rather larger than those of the iron-sand, but very similar to them in their appearance. Their edges are blunt ) they are smoother^ and have a stronger glimmering lustre than those of the iron-sand. Lustre semi-metallic, inclining to metallic. The fracture could not be distinctly observed, but it seemed to be conchoidal ; at least nothing resembling a foliated fracture could be perceived. Opake, semi-hard, brittle, easily reduced to powder; colour of the powder unaltered; specific gravity 4*491 *; scarcely attracted by the magnet. 1. A hundred grains of the powdered ore were mixed with six times their weight of carbonate of soda, and ex- posed for two hours to a red heat, in a platinum crucible. The mass obtained, being softened with water, dissolved completely in muriatic acid. When the solution was con- centrated, it assumed the appearance of the yolk of an egg. It was boiled, diluted with water, and set aside for some time. A white matter gradually deposited, which, when dried on the steam-bath, weighed 53 grains, and possessed the properties of oxide of titanium. 2. The liquid thus freed from titanium was evaporated to dryness, and the residue redissolved in water, acidulated with muriatic acid. A white powder remained, which, after being heated to redness, weighed 16' 8 grains, and possessed the properties of silica. 3. The solution was precipitated by ammonia, and the brown matter which had separated, boiled for some time in liquid potash. The whole was then thrown on a filter, to separate the undissolved part, and the liquid which came through was mixed with a solution of sal-ammoniac. A white powder fell, which, after being heated to redness, weighed 3*2 grains. It was alumina. 4. The brown substance collected on the filter was dried, drenched in oil, and heated to redness. It was strongly attracted by the magnet, and weighed 52 grains. 5. It was digested in diluted sulphuric acid; but not being rapidly acted upon, a quantity of muriatic acid was added, and the digestion continued. The whole slowly dissolved, except a blackish matter, which became white when exposed to a red heat, and, as far as I could judge * If, as the following analysis would lead us to expect, the specimen ex- amined was a mixture of four parts iserine, and one part quartz and felspar, the specific gravity of pure iserine should be 4i)6"4. - G 4 from 104 Analysts of a Black Sand from the River Dee* from its properties, was oxide of titanium, slightly con- taminated with iron. It weighed rs grains. 6. The acid solution being concentrated by gentle eva- poration, a number of small yellowish-coloured needles made their appearance in it. By repeated evaporations, all the crystals that would form were separated. They weighed six grains. I redissolved them in water, and added some ammonia to the solution. A fine yellow powder fell, which I soon recognized to be oxide of uranium. Jt weighed 4*2 grains. 7. Thus it appears, that the 52 grains (No. 4.) attracted by the magnet contained 46 grains of iron, and six grains- of uranium and titanium. 8. The following are the substances separated from 100 grains of iserine, by the preceding analysis : Oxide of titanium. Oxide of iron, - Oxide of uranium, Silica, Alumina, Total, 12.5-0 , Here is an excess of no less than 25 grains, to be ac- cpunted ft^r by oxygen, which must have united to the three metals during the process. As to the silica and alu- mina, there can be little hesitation in ascribing them to grains of sand, which had been mixed with the ore. The pure iserine, in all probability, was composed of iron, ti- tanium, and uranium. If we suppose that each of these metals existed in the state of protoxide, we must diminish the titanium by one-fourth, the iron by one-seventh nearly, and the uranium, according to Bucholz's experiments, ty •ne-fifth. This would give us. Titanium, • Iron, Uranium, Silica and alumina 103-9 Here, tUeiir is still an e-icccss of nearly four per ecnti JBut this I am disposed to ascribe to the oxides of titanium iind uranium, having been only dried upon the steam-bath, LTpon the whole, it appears, that in the specimens of iserin« analysed^ Anulijsis of the Cray Copper Ore of Alrthreij, 105 analysed, the proportions of titanium and iron were nearly equal, and that the uraniCim did not exceed four per cent. The appearance of uranium surprised me a good deal. I perceive, however, that it has iilready been detected in this ore, from an analysis published by Professor Jameson, in the second vohmie of his Mineralogy, which, I understand, was made by Lauipadlus. The specimen examined byLam- padius yielded very nearly 60 pans of titanium, 30 of iron, and 10 of uranium. Whereas, in mine, if the foreign matter be removed, there was obtained, very nearly, 48 titanium J 48 iron, 4 uranium, 100 But there can be no doubt, that the iserine which T ana- lysed was still contaminated with a good deal of iroii-sand ; for it was impossible to remove the whole. XVII. Analysis of the Gray Copper Ore of Jirthrey, in Stirlingshire, By Thomas Thomson, M\D,, Edifi- I'urgh *. JL HE copper mine of Airthrey, near Stirling, consists of a thin vein, which runs through the west corner of the Ochils. It has been twice wrought, by two different companies ^ but, in both cases, was abandoned, after a few years' trjal. I went to it some years ago, and examined the ore, at the- -request of one of the proprietors. The specimens which were employed for the subsequent analysis, were the purest that I could select, out of a considerable quantity. I wag told, however, that from the lower level, which was at that time full of water, much richer ore had been extracted. But, afterwards, when the lower level was free from its water, I went down to it myself, and found the ore precisely of the same kind as in the upper, with this difference, that it was more mixed with calcareous spar, and perhaps, on that account, more easily smelted. The veinstones in the Airthrey mine are sulphate of ba- rytes and carbonate of lime, and with these the ore i» al- iiioer had been laid before the Society. 1 was led to the present investigation, while preparing my lectures on the Kunterian Museum, in which the secretion* in different animals are ta be considered. In September last, I engaeed Mr. \Villiam Brande to assist me in prosecuting the inquiry. In Noveniber, I communicated my opinions to Sir Joseph Banks, aud stated that I should bring them forward in my leC' . , , turesj Hints on the Sulject of Animal Secretions, I09 the idea that the animal secretions may be produced by the same means. ' To prosecute this inquiry with every advantage, requires a knowledge of an.iiomy, physiology, and chemistry, rarely to be met with in the same person. [ have the 2 lb re availed myself of the assistance of the different members of this society, the object of which is the improvement of animal chemistry. Their intimate acqiiaint:^ncc with ihesebranchcs of science renders them peculiarly fiued for such an un- ilertaking. It is one of the most important subjects to v;hich Mr. Davy's discoveries can be applied, and he has given it the consideration it deserves. The Voltaic haltery is met with in the torpedo and elec- trical eel; and although it is given only as a means of catching their prey, and defending themselves, and there- foVe not imnn-^diately applicable to the present inquiry, yet it furnishes two important facts: one, that a Voltaic battery can be formed in a living animal ; the other, that nerves are essentially necessary for its management; for, in these fish, the nerves connected with the electrical organs exceed those that go to all the other |)aris of the tish in the pro- portion of twenty to one. The nerves are made up of an infinite number of small fibres, a structure so different from that of the electric organ, that they are evidently not fitted to form a Voltaic battery of high -power; but their struc- ture appears to Mr. Davy to adapt them to receive and pre- serve a small electrical power. That the nerves arranged with- muscles, so as to form a Voltaic battery, have a power of accumulating and com- tures ; at that time Dr. Young's Syllabus was not published, and Dr. Wol- laston's opinions were unknown to me. Dr. Berzelius, professor of chemistry at Stockholm, published a work on Animal Cliemistry, in the year 1806, in the Swedish language, in which he states, in several places, that he believes the secretions in animals to depend upon the nerves,, although he is unable to explain how the effect is produced. In proof of his opinion, t'le following experiment is adduced : " Trace all the nerves leading to any secretory organ in a living animal, and divide them, b«;ing careful to injure the blood vessels and the structure of the organ itself, as little as may be ; notwithstand":ig the continued circu- lation of the blood, the organ will as little secrete its usual fluid, as an eye deprived of its nerve can see, or a muscle whose perve has been divided cai\ move. We may therefore easily conceive, that any trifling alteration in the nerves of a gland may materially affect its secretion, the supply of blood being in every way perfect." He says, the agency of the nerves in secretion has generally been disre- garded, because our attention is only called U) their secret mode of acting^ when we discover the insufficiency of all other explanation. Dr. BerzeUus*% Tiyorjc was shown to jne by Mt. Pavy while ihis paper was in the press. municating 110 Hmts on the Subject of Animal Secretions, municating electricity, is proved by the well-known expe- riment of taking the two hind legs of a vivacious frog, im- mediately after they are cut off, laying bare the crural nerves, applyins: one of these to the exposed muscles of the other limb, and then when the circle is completed by rais- ing the other crural nerve wiih a glass rod, and touching the muscle of the limb to which it does not belong, the muscles of both are excited to contractions. There are several circumstances in the structure of the nerves, and their arrangements in animal bodies, which do not appear at all apphcable to the purposes of common sen- sation, and whose uses have not even been devised. Among these are the plexuses in the branches of the par vagum v-'hich go to the lungs, and in the nerves which go to the limbs. The ganglions, which connect the nerves belong- ing to the viscera with those that supply the voluntary muscles, and the course of the nerves of the viscera which keep up a connexion among themselves in so many diffe- rent ways. The organs of secretion are principally made up of arte- ries and veins ; but there is nothing in the different modes m which these vessels ramify, that can in any way account fe)r the changes in the blood, out of which the secretions arise. These organs are also abundantly supplied with nerves. With a view to determine how far any changes could be produced in the blood by electricity, at all similar to se- cretion, Mr. W. Brande, who has begun his career in ani- mal chemistry with so much success, made the following experiments, in the suggestion of which Mr. Davy afforded him every assistance. Experiment!, Middle of January, I8O9. The conductors from twenty-four four-inch double plafes of copper and zinc, charged with a very weak solution of muriatic acid, were immersed in four ounces of blood, im- mediately on its having been withdrawn from a vein in the arm. The temperature of the blood was kept up at 100** during the experiment. The apparatus was so constructed as to admit of the products at the negative and positive wires being separately collected and, examined. When the electrization had been carried on for a quarter of an hour, all action seemed to have ceased. The blood which had • surrounded the negative wire was of a deep red colour and extremely alkaline; that surrounding the positive wire was slightly acid, and of a brighter hue. In Htnls on the Subject of Animal Secretions, J 1 1 In this experiment, the coagulation of the blood was not materially affected by the electrical power alluded to. Experiment l\» 8th of February, 1809. Finding it necessary to submit perfectly fluid blood to the action of electricity, the following experiment was un- dertaken with a view of keeping it the longest possible time in that state. A deer having been pithed, the abdomen was immediately "Opened into, and a length of about four inches of a large vein in the meso-colon was detached from the neighbouring parts. Two small platina wires, connected in tlie usual way with forty three-inch double plates, were inserted into this detached portion of vein, and secured by ligatures, having their points at a distance of about one inch from each other. The communication with the battery was kept up for one quarter of an hour, a third ligature was then tied in the centre of the detached vein, in order to cut off the connexion between the positive and negative ends. On removing the portion of the vein included by the ligatures, and containing the conductors, it was found that the gaseous products had forced out nearly the whole of the blood, at the part through which the wires were inserted ; alkaline and acid matter were readily detected^ but no new product could be discovered. Finding the coagulation of the blood an insurmountable obstacle to the long-continued electrical action, the serum only was employed in the following experiments. Experiment Ml, lOth of March, 1809. The conductors from one hundred and twenty four-inch double plates, highly charged, were brought within two inches of each other, in some recent serum of blood, ob- tained free from the colouring matter, by carefully pouring it off from the coagulum. Coagulated albumen was rapidly separated at the negative pole, and alkaline matter evolved : at the positive pole, a small quantity^ of albumen was gra- dually deposited, and litmus paper mdicated the presence of acid. These are the effects produced by a high electrical power upon serum. Experiment \Y , 14th of April, 1809. Was undertaken to ascertain the effect of a low power : a battery was employed, consisting of twelve four-inch double plates of copper and iron. In this case, there was at fir$t no appearance of coagulation at either pole ; in fivt minutes' 119 Wnts on the Subject of Animal Secretions^ minutes, the positive wire became covered with a film of albumen, and in fifteen minutes a filament of about a quar- ter of an inch in length was seen floating in the fluid_, and adhering to the same wire. Experiment V. 6lh of May, 1 8O9. Two small plalina cups, connected by a large quantity' of cotton well washed, and each containing one ounce of jterum, were rendered positive and negative, by thirty double three-inch plates very weakly charged. The process was continued during twenty-four hours. This power had not been sufficient to produce coagulation at the negative pole. On examining the fluid in the negative cup, it was found to consist principally of an alkaline solution of albumen. The fluid in the positive cup was rather turbid, it red- it has in pact don^ our Paris mineral surveyors, that si'pcr-positian alone can H 2 iifttrurt 1 1 6 Geological Remarks on the answers to an assemblagt- of contiguous* and allied strata, as the genera of plants and animals do to their species. I shall begin with the names of the material places mentioned, and refer to the pages of the Memoir in your Magazine in e^ich instance : adding, occasional remarks of my own, in parentheses. Aiitonl, 11 miles SW. by W. of Paris, has plaster quarries at the edge of the gypsous soil; wherein the remains of manimiferai are found, and whose intervening marles are without lenticular gypsum; probably this is the upper or first mass of the quarryman, p. 33. Ailinont has sand-pits, pure, without fossils, p. 56, Bagueux, (Bogneux by mistake) 4^ miles SSW., has plaster quarries in the first mass, (sec ^/z/owf above). p. 53. Beance is a very extensive and high platform of (alluvial) Sand, whose extremities are Courville N W., and Mon- targcs SE., (which should have been described in ar- ticle X. if the memoir had not abruptly terminated) to the westward of Paris, whose very indented north- eastern i^(^^Q', from the Maulde river to Nemours, forms the south-western limits of the district called the Bason or Environs of Paris, which is the subject of this Memoir, p. 38 and 39. Boh de Boulogne^ 4-\ miles NW. by \V,, is on a plain co- vered by flint gravel, p. 58. Bonglval near Marly, 10 miles W., has chalk-pits, in distinct beds, with few flints : the chalk here has no covering, except in some places (alluvial) marly sand, containmg small and large blocks of calcareous stones of a very fine grain, (perhaps the gray-wethers or cherly blocks of our Wiltshire and other chalk hills)* p. 41 and 43. Chmnpagne Province, to the eastward of Paris, Is a very large district of chalk (forming large plains) having isolated patches (or hummocks) of (alluvial) sand upon them. p. 39 and 40. Ckampigmjy 8 miles SE. by E., has quarries and lime- kilns ; instruct us,, as to the relative ages of particular soils. The formations or »oil8, numerous as they are, which the Werneriaiu describe in the order of their respective ages, according to his theory, are found inapplicable by most correct ol>servers, in districts distant from those on wiiose soils they were originally founded ; and hence the Derbyshire limestone is not found by Mr. W. Martin to accord with the Wernerian Hypothesis, p. 158 : or the gyppums of Paris observed by M. Cuvier and M. Broguiart, with any of M. Werner's Formations, p. 53. ♦ In the order of super-positioo. the Siratzfication tf France and England. J 1 7 theHmestoneis fine-grained, and was porous (cavern€UT)f but is now compact, owing to the infihration of silex into its cavities ; it is without fossils, p. 55. Chantuly, l ^ miles N., lias madrepores, with camerines and other well preserved shells:, on the declivity of the mountain, and coarse quartz grains, Fonning a sort of puddingstone. p. 47. C/za/oz^ (Chaieu by mistake), Smiles NW., has flint gravel accumulations, p. 5S. Chaumonty 29 miles NW., is on the north-western cdi>e of the bason or environs of Paris, described in the Me- moir; having chalk strata as its boundary; with the coarse limestone strata of Fallenj in its vicinity, p. 39 and 47. Chelles has plaster quarries, at the extremity of the gyp- seous soil, in the first mass, (see Aiitoni above), p. 53. Clamari, 5\ miles SW., has quarries of coarse limestone, and above these, quarries of plaster; which are at the edge of the gypseous soil, in the first mass, (sec yl't- toni above), p. 49 and 53. Compieg?ie, 33 miles NE.,is at a reentering angle or inden- tation of the NE. side oF the district, called the bason or environs of Paris in the Memoir. Mount Ganelon, with a puddingstone of quartz and shells on it^ is near this place, p. 39 and 47. Concale Bay near St. Maloes, 1 60 miles W., produced oysters on its shores since the earliest records, which have not given place to other shell- fish. p. 49. Conde , has pits of gray potters* or plastic clay. p. 44. Dammnriin^ 14 miles NE., has plaster-pits in the first mass, which have no covering strata of marie, &c. p. ,50. Esperiiay (Epernay), 56 miles NE. by E., is at the eastern ^d^Q of the bason of Paris;, which is described in the Memoir; having chalk strata as its bounds, p. 39. Etampes, 23 miles SSW., has sand-pits, pure, without fossils, p. 56. FojilaJnelleaii, 24 miles SSE.— ditto ditto ditto. Fonta'webleau Forest, SSE., a rugged and une'-cn district : siliceous limestone is here found, producing bur- stones, (French Burs, used here in making n)ill-stones): sometimes the covering or superficial strata are allu- via or argillaceous marles, and sometimes free- stone without shells, which last alternate with sand, which- H 3 is 118 Geological Remarks on the is sometimes displaced, leaving the blocks of stone lying in confusion : sometimes these free-stones arc coloured or rendered calcareous or argillaceous by in- filtration from the covering strata, p. 30 and 36. iFontenay-auoc- Roses y b\ miles hSW. : here M. Lopez silnk a deep well in his garden, through the gypsum and coarse limestone formations, p. 50. Ganelon Mountain, near Compiegne, NE., has (alluvial) puddingstone on it^ of coarse quartz grains and shells, &c. p. 47. >Gentilly, 3 miles S., has pits of coloured potters' clay, which stratum extends in a range to Meudon : it has also quarries of coarse limestone that produce in their lower beds periwinkles, solens, (omitted in the transla- tion) oysters, muscles, pinnae, calyptrae, pyrulse, large tellines, terebellse, porpytes, madrepores, nummulites, and fungites ; above which are strata of greeiv earth with some vegetable impressions, then gray or yel'- lowish strata containing venuses, camprcys, and nunie- rons tuberculated cerites : beds of good building-s^tone ; , above these is a stratum containing an entire bed of small long and striated tellines : the fossils are the same in these quarries as at Grignon and Meudon^ and on the top of Montwartre, p. 44, 47, 48 and 5b. Oisors, 35 miles NW., is at the extreme NW. corner of the bason of Paris described, and adjoining the chalk di- stricts. Mount Oz/i«, with a puddingstone of quartz and shells in it, is near this place, p. 39 and 48. Grignon , has quarries of coarse limestone, whose lower beds contain periwinkles, and the twelve other kinds of shells and fossils mentioned at GentiUy, with the addition of cerites (as mentioned p. 54) ; also the fossils agree with those of the quarries at Matdon and . on the top of Montmarire. pages 47, 54 and 55. Grisy is situated at one extremity of the gypsous district and Meaux at another ; it has only the first mass of gypsum in its quarries, p. 49 and 53. Guespelle , the strata of this place answer" to those of Gentilly, above, p. 47. fiigk Normandy province, to the north-west of Paris, is wholly composed of chalk (forming the N W. border of the basin of Paris), p. 39. Houdan, 28 miles W., has pits of gray potters* or plastic clay. p. 44. Jssyy 4 miles SW. by W.^ has quarries of coarse lime- stone. ,Sf ratification of Franpe and ^ngland^ 119 P 'stoDe, with periwinkles and the twelve other fossil re- mains in their lower beds, that are mentioned of Gentilly, p. 47. Ldofinois is a district (of chalk) NE. of Compiegne be- tween the rivers Oyse and Anre, which bound the basin of Paris, and tbrnns therein a consklerahlc reen* tering angle, p. 39. LofigjjimeaUy 9 miles SW. by W., has 'siliceous freestone and sand, containing the 13 kinds of shells, &c., found at Gent'dh/ and Grignon, with the addition of balani : towards the top of the hill a sand (probably alluvial) contains lymnece and planorbis with siliceous wood, and other parts of vegetables, p. 54 and 57- Mantesy 22 miles WSVV., is on the NW. edge of the basin of Paris, and adjoins the chalk district without it. p. 38 and 39. Maiilde Kiver, which empties itself into the Seine, is a^ that place the limits of the basin of Paris, attheNW. end of the (alkivinl) sands of Beaiice, which form its crooked boundary SE. tlience to Nemours, p. 38 and 39. Mcanxy }g miles NE. by E., is situate at one extremity of the gypseous district within the basin of Paris, and Grissy is at another, p. 49« Meudon. Q miles SW., has chalk-pits, in which are layers of flints about 6y feet apart, but no detached fiints in its mass ; the upper part of the chalk is in a rubbly state, with the clay of the superior strata in its inter- stices. A stratum of coloured potters* clay, without fossils, covers the chalk here, and extends south-east- wardly to Gent illy : above this clay, coarse limestone strata here occur, and the lower beds in the quarries contain calyplreae, fungites, madrepores, muscles, nummulites, oysters, periwinkles, pinnje, porpvtes, pyrulae, solens, large tellines, and terebcllae; which fossils are of the same kinds as those of the quarries of GeiitUly and Grignon and on the top of Montmar' ire* The gypsum soil occurs here upon the coarse limestone soil ; there are only thin beds of plaster in it, but which are sufficient to fix the relative super-posi- tion of«these soils, pages 41, 43, 44, 47, 49, 53 and 55. Montmartre, 2| miles N., has had its strata and fossils de^ scribed by M. Desniarets ; it has large plaster quarries in which are three principal masses of gypsum, the low- est of whieh is without fossils, and has only thin bedsof j;ypsum, frequently sclenitous, with intervening strata H4 of 120 ^ideological Remarks on the pf solid calcareous marles, that contain course crystals : , pi lentkular yellowish gypsum ; and with very scaly argillaceous niarlcs that contain nienilite silcx. The middlcfniass has thicker and more numerous beds of gypsum, the intervening solid calcareous marles have in them numerous coarse crystals of lenticular yellow- ish gypsum : some pF these beds, those that are marbled with gray and are compact and argillaceous, are used lor scouring- stones (not building). It con- tains scattered nodules {rognojts) of gulphated strontian ill its lower beds ; and it is chiefly in this mass that fossil fish (not shcll-fish) arc found, ^he upper mass is very thick, diiefiy of beds of gyp- sum, interlaid with a lew marley strata : its lower beds of gypsum are intermixed with siliceous masses, its middle beds are columnar, and its upper gypsum , beds are usually interlaid with five strata of m^rle : this upper gypseous mass contains astonishing collections of the skeletons of birds, of quadrupeds, niammiferae, and fish, tortoise bones, and a few shells, agreeing with those of the fresh-water fish of our lakes. A large mass of marles occur above these, imbedding dif- ferent fossils (for which I must refer to page 31 and 52, to the Section, and to what follows herein). Above thcs.e marles, freestone and sand here occnr, that contain the 13 kinds of fossil remains, menticmecl at Gentilli/f Meudon and Grignon, with the additioii of balani shells, pages 37, 50, 51, 52, 54 and 55, Montmorency^ 10 miles NE., has the upper mass of gyp- sum, and its fossils (see Montmartre) forming the surface, in s.ome parts";, in others, it has above the gypsums and marles, the freestone and sand which contain the 14 kinds of fossil remains that are found on Montmartre &c. p. 50 and 54. MoJitereau, 22 miles SE., is at the south-eastern edge of the basin of Paris described by our authors, and ad- joins the great chalk districts in Champagne : gray potters' clay is here dug, upon the chalk, p. 39 and 44, Montfort, 18 miles VV., is near the western edge of the basin of Paris*, p. 39. "Mont Valerian , has plaster quarrier*. near tlie edge of the gypsous district, where only tb^ first or upper mass of gypsum appears, p. 53. Morel, in Dreux Forest, has pits of very white potters* (or pipe-)clay; it covers the chalky and is withoul. fo3- - . sils. p. 44. Nanlerrcy Stratification of Prance and England. 12 J Nanterre^ 71 miles NW^., has a plain covered by flint- gravel, p. 58. Nemours, 32 miles SSE., is at the limits r)f the basin of Paris, and at the SE. ead oF the (alluvial) santone and the blue Lias soils, in this country, there is a stratum of limestone called by Mr. Smith the blue marle-stotw, which contains very perfect belemnitc5, MTJall cornu-ammoni and asteria. The limestone of Oakham, and of Maidwell, between Northampton and Alarket-Harborouj^h, belongs I believe to this itratum, but 1 never had the opportunity of collecting any specimens at tha latter place. Camprey Stratification of France and England, 135 Camprey shells, at Gentilly, Saint Germain, Villepreux, &c. ill the building-stone rock above the coarse lime- stone, p. 48. Cardium shells are found in the yellow argillaceous marie, some distance above the green potter*s earth of the gypsous soil, near its top. p. 52. Caryophylla^a (a polypicr) in the chalk strata, p. 42. Ceriie^ shells, often in fragments, at Gentilly, Grignon, Meudon, Montniartre, &c., in Uie lower beds of tlie coarse limestone, and in the freestone, p. 34 and 55, , tuberculat^'.d, at Gentilly, Saint- Germain, and Villepreux, &c. in great numbers in the building- stone rock, above the coarse limestone, p. 48. -, often in fragments, in the yellow argilla- ceous marie near the upper part of the gypseous for- mation, p. 52. Cranium, or skull, of yonoe animal, in the chalk strata, p. 42. Elephants* holies of unknown species, at Scran, 6:c, in the alluvium (of valleys), p. 58. Filrous shells, resembling very thick pinns, in fragments, in the chalk strata, p. 42. Fish (not shell-fi-sh), at Montmartre in the marbled gray gcouring (not building) stone of the middlemost gyp- sum mass, having scattered nodules [rognons) of sul- phatcd stroniian in it^ lower beds. p. 50. — — skeletons, at Montmartre, Dammartin, Montmorency, &c., in the gypsum or intervening marles.ofihe upper gypsum mass or tirst of the quarrymen. p. 51. Fie^h-nater shoW'i (resembling recent species of such shells) Lynmeae and PJanorbes, at Montmartre, Komainville, &c., in the upper gvpsum mass, or the niarles which , cover it ; and from the decomposing stone at Trappe, near Versailles, (denominated fresh-water by our Au- thors) resembling siliceous limestone, when first dug. p. 51 and bQ, Fipjgites, at Chaumont, Gentilly, Grignon, Gucspelle, Issy,, Meudon, Palkry, Sevres, Vaugirard, 8cc., in the lower beds of the coarse limestone, p. 47. Ceodes, round stones, some hollow, of a very fine-grained limestone, c(mtaining multitudes of small spiral uni- valves ; whose cavities contain a new variety of cry- stallized sulphate of stroniian, called apotamous sul- phated strontian ; these gcodes are found in**a marley (alluvial) sand, in some places,at Bougival near Marly, covering the chalk strata, which are themselves not found 135 Geological Retitarks oil the foutrd to contain any simple aud regular spiral ant-* valves, p. 42 and 43. Gyrogonhes, small round hollow (furrowed) bodies, re- sembling no known recent body, found at Trapped near Versailles, in the decomposing soil (denominated fresh- water soil by our Authors) which, when fresh dug, resembles hard siliceous limestone, p. 57. Leaves of vegetables and stalks, at Gentilly, Saint-Ger- main, Villepreu.\, &c., brownish, in the lower beds of the green earth, that underlay the building-stone rock of the coarse limestone soil. p. 48. ■ ' and parts of vegetables are found, changed into silex, near the top of the hill at Longjumeau, in (al- luvial) sand. p. 57. Lituoliies of two species, in the chalk strata, p. 42. Lymnece shells agreeing with recent species, at Romainvllle, in a white and friable calcarer-us mass above the gyp- sums ; and at Trappe near Versailles, in amarle therd used in af:;ricultnre, which when fresh dug resembles hard siliceous limestone, p. 51, bQ and 57. — coarse shells in silex, are found in the (allu- vial) sand, on the tops of the hills at Longjumeau. p. b7. Mactre shells are found in the yellow argillaceous marlc that is above the thick green potters' earth of (he gyp- seous formation, p. 32. Madrepores, at Chaumont, Gentilly, Grignon, Guespelle, Issy, Meudon, Pallery, Sevres, Vaugir^rd, &c., in tiic lower beds of the coarse limestone, p. 47. J[laJ7imiferce, bones of, at Antoni, Bagneux, Chelles, Cla* mart, Grisy, Montmartre, Triel, Valerain-mont, &c. in the upper gypseous mass. p. 51 and 53. — skeletons, of large unknown kinds, are found in the putrid alluvium (of some of the valleys), of the basin of Paris, p. 58. Jilillepora, (a polyper) of decomposing pyrites, in the chalk strata, p. 42. Mollusci of the chalk strata are quite different from the testa*- ceous mollucsi of the strata above the chalk, p. 54.- Muscles of one particular species are found ia the chalk strata, p. 42. I ■ ■' at Chaumont, Gentilly, Grignon, Guespelle, Issy, Meudon, Pallery, Sevres, Vaugirard, &c., in the lower beds of the coarse limestone, are found to be of other species, p. 47. Stratification of France and England, 1 27 Kumn^iUtes are found at Chaumont, Gentilly, Grignon^ Guespelle, Issy, Meudon, Pallery, St^vres, Vaugirard, &c. in the lower beds of the eoarse Hraestone strata, p. 47. Qxen (bulls or cows), skeletons of unknown species, in the alluvium (of valleys), p. 58. Oysters of two different species are found in the chalk strata, p. 42. — ' at Chaumont, Gentilly* Grignon, Guespelle, Issy, Lonajumcau, MeuJon, Montmartre, Montmorency, Pallcrv, Uomainville, Saint Prix, Sevres, Vaugirard, &c. Other kinds of oysters are found in the lower beds of the coarse limestone, and also in the freestone, p. 47, 54 and 55, '*■ arc found in the marlcs that are immediately be- low the argillaceous sand, at the top of the gypseous formation, in two beds, the lower containing large, and the other small oyster shells ; thuy are met with over all the district wherein the entire gypseous forma- tion is found, p. 52. Palni'trees, trunks of large size, are found converted into silex^ lyir^g along in a whitish friable calcareous mass above the gypsums, p. 5 J. Periwinkles are found at Chaumont, Gentilly, Grignon, Guespelle, Issy, Meudon, Pallery, Sevres, Vaugirard, &c., in the lower beds of the coarse limestone, p. 47. Finncs shells of a particular species are found in the chalk strata ; in which also, fragments of thick shells of a librous structure are found, which our- Authors con- sider as more like pinnx than any other known genus* p. 42. -— of different species are found at Chaumont, Gen- tilly, Grignon, Guespelle, Issy, Meudon, Pallery, Sevres, Vaugirard, &c., in the lower beds of the coarse limestone, p. 47. Planorhis shells, analogous to the recent species of lakes and marshes, are found at Romainville, in a white and friable calcareous mass above the gypsums ; also, .^t 'iVappe near Versailles in the husbandry marle|. which though very decomposing, resembles a hard si- liceous limestone when fresh dug.' p. 51, 56 and 57. — coarse siliceous shells are ft;)und at the lops of the hills at Longjumeau, in a sand (which is probably al- luvial), p. 57. Poll/ filers of live or six difierent sorts are found in the wl^alk strata, p. 42. Porpyte^ I2& Geological Remarks on the Pvrpi/les of different kinds are found in the chstlk strata,* p. 42. at Chauntont, Gentinvy Grignon, Gtiesptlle, Tssy^ Mcudon, Pallery, Sevres, Vaugirard, &c. of different Fpecies from thr)se in ihc ehalk, are found, in the lower beds of the coarse limestone, p. 47. Fyrulce shells arc found at Chauniont, Geritilly, Grignon^ Guespelle, Issy, Meudon, Pallery, Sevres, Vaugirard, &:c. in the lower beds of the coarse linicstone, p. 47. Ouadntpcds, skeletons of, at Antoni, Bagneux, Chelle?, Clainart, Grisy, Montn^artre, IViel, Valeram-nionnty ^cc. of several kinds, are found in the upper gypsunir mass. p. 51 and .53. • , I he skeletons of various large on'ea, are found in the (vallev) alluvium of the basin of Paris, p. 38. Sea^shells (resembling recent genera or species of such shells), viz., cardiums, cerites, mactrcs, oysters, ve- / nuses, and other bivalves, are found in the marles that are below the argillaceous sand at the top of the gyp- seous formation, p. 52. ■■ of various kinds abound in the lower beds of the coarse limestone at Chaumont, Gentilly, Grignon, Guespelle, Issy, Meudon, Pallary, Sevres, Vaugi- rard, &c. p. 47 and 54. Shark\<: Teeth, see Teeth. SoUmce shells (omitted in the translation), at Chaumont/ Gentilly, Grignon, Guespelle, Issy, Meudon, Pallery, Sevres, Vaugirard, 5cc. in the lower beds of the coarse stone, p. 47. Spirorbis^ a species of these shells is Found in the chalk strata, p. 42. Stalks of vegetables, see Leaves. Teeth of Squali are found in the chalk strata, p. 42. Telline shells of different species are found at Chaumont, Gentilly, Grignon, Guespelle, Issy, Longjumeau, Meudon, Montmartre, Montmorency, Pallery, Ro- mainville. Saint Prix, Sevres, V^augirard, &c., in the lower beds of the coarse limestone, p. 47 and 54. — small, long, white, and striated, are found iii vast numbers in seams, close to each other, in a stratum that covers the building-stone rock of the coarse limestone formation at Gentilly, Saint-Germain, \^il- lepreux, Sec. p. 48. ——-small and elongated, closely packed in a very thin scam, below the thick green pollers' earth of the gyp- seou,*i Straiification of France and England. 1 29 seous formation ; which thin seam can be traced in the quarries, over a space of 27| miles long and 11 miles broad, p. 52. TcreltUcB are found at Chaumont, Gentilly, Grignpn, Gucspelle, Tssy, Meudon, Pallcry, Sevres, Vau- girard, 8cc., in the lower beds of the coarse lime- stone, p. 47. Terehrnlula, see Anomites. Tliornhatk fish, fragments of the bones of, found in the yellow argillaceous marie, above the thick green pot- ters' earth of the gypsous formation* p. 52. Tortoise bones are found at Dammartin, Montmartre, Montmorency, &c., in the gypsum or mtervening marles, of the upper gypsum mass. p. 51, TreeSy trunks of, large palms (apparently), converted inla silex, are found lyuig flat in a white and friable calca- reous stratum, above the upper gypsum mass. p. 51. , large trunks of, of unknown species are found at Seran, &c.,inihe putrid alluvium (of the valleys). p. 58. — ■ — sec Wood. Trochi shells are found in the yellow argillaceous marie, near the upper part of the gypsous formation, p. 52. Vegetables, see Leaves. Funis shells, roundish, are found at Gentilly, Saint-Ger- main, Villepreux, &€-, in the building-stone rock of the coarse limestone formation, p. 48. « , sometimes in fragments, are found in the yellow argillaceous marie near the top of the gypsous forma- tion, p. 52. FirmiculUes^ of three speci<5s, are found in the chalk strata. p. 42. IVbod, bituminous, at Rolleboise, by the Seine river, in the potters' or plastic clay formation, in which no other organized remains have been found, p. 44. F siliceous or petrified, at Longjunjcau, on the tops of the hills in (a;luvial) sand. p. 5/. , sec IVi es. In order to supply, in some degree, the want of vertical Sections across tt»e basin c»»' Paris, in some determinate di- rections, best adapted for exhibiting the thicknesses and re- lative positions of its several strata; (wliich section:, it is to he hoped, will accompany the promisee; Memoir of M.Cuvier and M. Bmgniart) ; 1 have, in the mean fmc, attempted an arrangement jrom their abridged M» moir, which, per- haps, you may deem worth a quarto na^e, to enable it to be folded out at the end of this Letter, In this table, I Vol. 35. No. 142. PeZ'. 1810, I have 130 Geological Remarks on the have "Separated the IXth and Xth soils or formations by a double line, to mark the distinction between them and the remaining eight soils ; which our authors seem to consider as composed of rci^ular or undisturbed strata, that is, such as exhibitno marks of violent attrition or mecha- nical mixture, a:-: the alluvial soils almost invariably do; and they, besides, never underlay regular strata. r shall now, [ hope, be excused in offering freely, a few of the observations which have occurred to me, in thus analysing the hasty but valuable Memoir of our able and industrious neighbours on the continent ; and comparing it with what 1 know of the ten'cstrial stratification, and which is indeed limited in a great measure to the British Islands. England presents us with the opportunity of ex- amining the out-crop, or appearance on the surface, of a vast succession of strata, among which the fourth, or lowest Derbyshire limestone, is,perhaps three miles of per- pendicular depth, below the part of the chalk strata, which are described as the lowest that have been seen or reached in the basin of Paris : for it was ascertained by Mr. IVil- liam Smith several years ago, that 200 feet or more of the lower part of the chalk strata are entirely without layers or nodules of flint ; and that some of these beds contain large cornu-ammonis, nautili, and numerous other shells : this he has proved by an actual examination of very near 700 miles in length, of the basset or out-burst of these lower and hard beds of chalk, without flints, reckoning from the Isle of Wight to the westernmost points of the chalk in Dorsetshire and Somersetshire, and thence for the north-east angle of Norfolk ; through Lincolnshire, and Yorkshire to Flamborough-Hcad ; and including the edges of our great southern denudation ''• from Bcachy- IJead in Sussex, to near Petcrsfleld and Alton in f Jamp- shire, and Farnham in Surry; and thence again to Hythe in Kent. And here it may not be amiss to observe, that before I knew Mr. Smith, he had ascertained the peculiar fossils that belong to several of the thin strata, underlaying the whole extent of tb.e edges of this vast mass of chalk, in the same rp.aimcr as the Paris strata overlay it, had col- lected a series of specimens of each fossil, marked and brought together from ns many places; and was well en- titled, and did in fact often exclaim, though perhaps, ia, • This denudatipn is shortly mentioned iu the CycjJop.tdia, article Coal, and is further exemplified bv ?. manuscl"i',.it section of the atrata between London and Brightan, made by me in IbOo, which is in the hands of many. Other Stratification of France and England, 131 other words : ** This constancy in the order of superposi- tion of the thinnest strata, and over an extent of" 700 miles in leni^th, ** is one of the most remarkable facts which" I *' have established. From this, there ought to result most intcresliug consequences to the Arts, and to Geology." But let us return to our chalk strata, which, as they form the basis of the Paris observations, require some further notice. I am mvself, unfortunately, not sufficiently ac* quaintcd with the French coast, to state the exact point where the chalk terminates on the shore to the south of Bolognc : and whether its termination there is occasioned by its edge rising, passing inland, and exhibiting the under strata on the coast, or whether the chalk by siul^ing down permits its upper strata to cover it at the level of the shore *; the former should perhaps seem the most probable, from the circumstance of M. Cuvier aiid his associate being able to assign a limit of naked chalk on all the north side of the natural district, which they huve rendered so interest- ing to science, under the appellation of the basin of Paris. On the north-east of Calais, tlie great plain of chalk seems to decline northward, and either its upper strata or alluvial matters, of no immeasurable thickness I apprehend, pro- gressively cover it as we proceed along the coast, or across any part of the Netherlands, from France to the southern part of the coast of Denmark. The chalk having, some- where in this immense flat, obtained its lowest point, as the bed of the German Ocean, it begins to rise again north- ward, finally to terminate in the Dogger-Bank and the other shoals which are seen in good charts, stretching across from the coast of Yorkshire to the Danish coast, where the chalk rises again, and its northern edge passes inland and across the island of Zealand, as I have been informed, the coast northward becoming occupied by the lower strata, which also pass over from the Yorkshire coast, further north than Flamborough Head. Flow then does it happen, that this vast plain of chalk (which' it still is, if we neglect its local inegularities) extending froni Normandy to Denmark, from the confines of Hanover to Dorsetshire, and from the south- ern border of Champagne to the middle of the Yorkshire coast, exhibits the strata and astonishing organic remains of the basin of Paris, only within that spot ? which is small compared with the whole space in which the chalk lies buried under other strata, either regular or alluvial. Is it ♦• Perhaps some of yovir ccrrcspondents can jT^ratify me and the other geological inquirer* among your readers, by an answer to these questions. 1 2 because 13i Geological Heinatks oh the because the edges and accessible parts of the sirata snperin- cumbent upon chalk, have not been sulFrciently till novr any where explored, to delect the peculiar and interesting indications of these strata, which we have now the autho- rity of two most able naturalists, it* saying, exist in such profusion, and are each disposed in such unerring regula- jritv, that a very thin bed of lelline shells was observed hy them over a district more than 274^ miles long, and more than 11 broad ? This I think would hardly seem likely, v^s fpr as Great Britain is seated upon the chalk strata, alter the \ouz ^nd indefatigable researches of Mr. Smith and of bis followers, as well as of other En.glish naturalists, who seem always to have been alive to preserving and de- scribing the bones, teeth, and other rare fossil remains, which accident or the miner exposed ; though in few in- stances, perhaps, with all these acute discriminations, which our authors are able to bring into this importaiit field of in- quiry. Again, is it because the Paris strata, though depo- sited alike on the English chalks, either never did here holdy or now preserve no traces of the myriads of organized r^e- mains, which are so perfectly preserved in the French part of these strata, although they once existed here also ? And again, are the London clays, aad the sands beneath and above them (in some places), to l>.e considered as the Paris strata in a modified state ? * Or, should the Paris strata be wholly wanting in England, in that case, are the matters* fcere covering the chalk, belonging lo the alluvium ? or are they local strata placed by tlie side, or parallel with, the Paris strata, as our authors maintain to be the case with two t)f their soils or formations, viz., the Vth and Vlth ? I shall only offer a few remarks, and not aUempt, at pre- sent, a full discussion of the above six queries, but beg ra- ther to throw them out, as subjects worthy the researches and consideration of your readers and correspondents, and particularly of the members of the London Royal and Geo- logical Societies, who will, I hope, excuse me in hijiting, that the national honour seems to call upon them, to bestir themselves, in the accurate investigation of the strata on which thery are seated : and in the discussions necessary for truly fixing their relations to those, on which the Parisian Institute have thus lamentably been suffered to take the lead . It will be gathered from the imperixct sketches, to which * Perhaps as grp:\t dissimilarity hi the state and api)erirance of some par- xicuUr strata, in distant places, lias in other ins-t.tnces been observed in Bri- tajMr where the inferior and superior strata pj>>vc the identity. I have Si ratification of France and England. ? 3 3 1 have referred, as well as recollected by Mr. Smith's pupils and acquaintance, that he considers and teaches, that the western edges oF t-he several strata on the south and east- ern parts oF England, are their natural endings, and that such strata never did proceed further towards the north- west than they do at present, and that all the strata are not entire or perhaps ever were, some having large and deep holes or patches wanting within their limits, as well as in their deeply fingered or indented edges; while other strata, particularly about Bath, have detached parts beyond their continuous mass forming hummocks, or capping the adja-^ cent western hi. Is. These facts or appearances of the strata' have accorded, generally speaking, with the several English districts which \ have of laie years examined ; but many of the minuter circumstance? attending the holes or denudated patches in the strata, which have been more particularly the cKbject of my researches, such for instance as the strata around and under these denudations, rising on all sides io» wards some central point or ridue; their edges being so often abrupt and straight, like fractures rather than tht rounded endings of strata: these denudations, as far at least as ob* servations extend, being all elongated in a marked manner from SE. to N\V., or very nearly so; and others, besides thosewhich I have elsewhere mentioned as tiie characters of denudation, and above all^, the vast extent to which I iind these denudations extending, in the southern and \uid- die parts of England, have occasioned me to hesitate consi- derably,-as to the real distinctions, between the natural endings and the denudated edges of our strata: and it should seem, that the idea so natural and general among neptnnists, of the strata having been originally level and concentric^ iTiay, by extending the magnitude of the denudation^" (to which no limits have yet been assigned), account for all the external forms of the English strata, and perhaps for the admirable form of its valleys, although I may again invite the sircastic lash of a certain class of writers, in frankly owning that I am unable to guess, much less to describe the mechanical operations b.y which this has been brought about ; and in referring it to the finishing and all-wise ope- rations of Creative power, on the mass of the earth, or old world, as our authors have denominated it; which had been the theatre of such a long and astonishing series of the creation and extinction of animated beino's, durmg the ac- cumulation of its matter, for purposes which are perhaps to us inscrutable. Whether the isolated hillocks or hummocks of gypsous T 3 and 134 Geological Remarks on the and other strata, which our authors have tlescribed in th6 basin of Paris, are the detached endings of similar and connected strata, that lay to the south and west of Paris, and may either be concealed by vast alluvial tracts (p. 40), or i7)ay occupy countries where nice observations have not yet been made ; or, whether such hummocks be occasioned by irregular or compound denudation*, such as I have noticed several instances of in Derbyshire, and as Mr. Smith has observed about Bath, and Dr. William Richardson in the north of Ireland f, it is of course difficult to determine, Rm\ its discussion must be deferred, until a numerous train of facts are better understood. Our authors, it will be seen, recur to a local inundation or lake oi fresh- water % U)X explaining the deposition of the matter composing their gypsous hillocks: to me, how- ever, much better evidence seems wanting, of the probable existence of such a lake or local pool of fresh-water than they offer, and particularly of the several successive /re5/^- and salt-water inundations which they mention, at pages 54 and 55. Has it, or can it be proved, that fish nearly or exactly resembling in the genera, or even the species, those that are noiP peculiar to cnhtrjresh- or salt- wafer, may not have had other powers and habits in the old world P and that all the animals and even birds hitherto known of the primitive creation, and its vegetables also, may not have been ado})ted by their great Author, to a sub-aqueous ex» isience ? And again, Who has or perhaps can, determine, whether the fluid surrf>undii'»g the earth, during its formation which I have caHcd aqueous above, was either fresh or salt, in the sense that we now use those terms? Does it not seem more probable, that this fluid varied essentially from time to time in its nature and composition, and whicli per- haps occasioned the extinction of the beings adapted to its prior state, as well as the alternations of the strata, espc- pecially, if the matters of the strata were, ever in chemical solution in it, as our authors seem to imply (p. 51), in * Perhaps the ba:^in of T:irh may He within the southern vcr^e of the great 8i>uth-!.'a'tcrn denudation of En^^hind, that readies far into Hampshire, and has apparently s:ilpt olF;.!! the chalk strata, from near Alton to Bologne on the Frjnih coast. I See our 33ril volume — Eoit. ^ U -secruK inrprobal^le that gynsum sh.ould be a produce of fresh-water, when we refiect, that the red soils or gypsous marles of Knpland produce boih sea s^'.t and g-ypsinn in vast ahu?!dHncc, and tiiat salt rocks and springs are the common accompanin^.cnts r,t' g^'psuni in various oilier parts of the work- 1 we are not told, whether there are any brackifch or salt springs with- in the baaia of i'aris. speaking Slraiificalion of Fra7ice and Ungknd, 1$S speaking of the cvp^sums being crystallized fronn the waters oF their l*arisian lake ? The candid confession of ilie essential differences between the seaSf the fresh- waters and (lie alluvium o^ the old world, and the seas, fresh-waters and alluvia of the present world, made bv uux auttjors, in the concluding paragraphs of iheir II Id, Vllfih, and IXlh articles, do them credit, and give some weiglit to my suggestions above, which are not here made for the first time. Our authors say (p. 3 7), 'that *^ a strongly marked cha- racter of a great eruption proceeding from the south-east i^ imprinted on the forms of the eminences," f)n which subject it may be proper to remark, tliat soon after Mr. Smith had commenced liis investigation of the Britisli strata, he discovf.red an important law regulating all the knoum alluvia, or that which consisted of or contained the frag- ments and rehquia of known strata, were moved /707W the south-cast towards the south-west : the matters of any particular stratum being rarely if ever found as allnvinni upon tiiaistratnui, l>ul such matters are found more or less plentifully on the surface, beyond its w^estern edge: in- stances arc numerous m blngland of considerable and un- broken masses of soil or clayey known strata, being moved many miles and lodged in the alluvia ; stones of large size thus moved, and scarcely at all rounded, are exceedingly common in some districts, and such are often lodged on the highest hills, but the most common state of the native alluvia, is in small water-worn and mixed fragments: nu- merous hills in Bedfordshire of considerable extent are thus formed or raised higher, by alluvia of the chalk strata and ^Jhose which cover it, including a vast variety of limestone holders that are full of shells, many of which, if properly examined, would I suspect aiircc with the coarse Tunestones of the basin of Paris : nw researches in the midland conn- ties, have detected many isolated patches of exacily similar alluvia, pariicularlv on the height NVV. of Leicester town, where an innneuse cap of alluvial clay, so abounds with hard chalk and these holders of limestone, that at Burstal Cliflf- house on the road to Thurnby» they have been dug for burning lime : the covering matter at Chellaston gyp- sum (juarrles S. of Derby, is of 'this same clay ; but lune- bolders do not there so much abound, as they do near Lei- cester and tJicnce in isolated paiches towards Market Har- borough, forming there the principal material for repairing the public road. The above wiih others are indications I think of vast tidal currents which have swept over all the surface I ^ from 186 Geological Remarks ow the from SE. to N\V., since or at the time, that the deposition of regular strata ceased, as observed p. 37. It struck me, as among the curious circumstances of the basin of Paris, that the strata throughout it are horizontal, at least only one itistance to the contrary is mentioned (p. 43), and that faults or such like derangements of the strata are nowhere mentioned. All ihe southern parts of Derbyshire and part of Lei- cestershire adjoining, abound with red carih or gypsous marie (entirely without fossils I believe) that is 7n like manner horizontal throughout, with three exceptions only, that I could discern : viz. at the S. of Burton Trent bridge on the E. side of Catton in Croxall, and MW. of Stretton- le-ficlds 5 the second of these only has any considerable inclination : although tilts of the strata are so rare in our gypsous strata, yet itiany faults seem to occur in them : a most tremendous one fcrms the northern limits of the i^^vp- sous miarle for 40 or 50 miles, and four or five isolated Time and coal districts witliin it, seem surrounded by great faults and to be intersected by numerous others, occasioning as inclining and dislocated strata at Breedon, Cloud's hill, Measham, Sec. as can almost any where be found. It is stated by our authors (p. 54 and 5 't), that their Vlh and Vlth soils are placed side by side of each other : if these be really different soils, and not the same somewhat naodilied in their substances, the fossils in one of them also not being preserved, (of which I entertain some sus- picion) a fanlt must, in all probability, ranse between the two places where these soils have been noted, which ele- vates one of ihe soiis or depresses the other. 1 would also here suggest as a query, whether their Vlllth soil be not a similar repetition of pan of these same soils? Its fresh-water shells are not sufficient^ I think, to prove it an upper soil ; and in the latter p?irt cyf the Memoir we are not presented with the same evidence pf the superpc^sition of the different soils as we are with respect to the first In'c, which may hov/ever have arisen from the haste in which the Memoir seems to have been pre]-)ared. I do not rc*member to have seen any where, the appear- ance of limestone strata Upon the chalk in England, or to have heard of any such from Mr. Smith, or otherwise : of gypsum T think we may safely say that there are no strata: but crystals of selenite abound in the London clay, and there are numeious patches of plastic clav, used in some places on our ciialk hil'^ for potttry and brick-making, which geem to answer pretty well to the description of some Si ratification of France and England, 137 <»oiTie of that within the basin of Paris ; but we cannot I think infer, that tliis same plastic clay underlays the Lon- don clay, in the neighbourhood of London, as there is ee- iieraliy a sand here imrnediaiely upon the chalk, but which varies greatly in thickness, from nmny yards (as in the sand-pits by the Thames between Greenwich and Wool- wich) to a few feet only or perhaps inches, in the borings oF some of the modern wells in and near the metropolis : still however this sand has always I believe be?'n found in this district, and it has generally been forced up wiih q;reat vio- lence into the well, by the water issuing from the joints in the chalk beneath, on first pricking this spring with the au- gef, or on any after occasion when the column of v/ater in the well is much and suddenly difninishctl, as often happens by the pumping at Mcux's brew house and Oiher places. Mr. Smith and myself have been nsed to consider the London clays as regular strata, and the layers of small re- gular flattened chert-stones which it contains, as nodules peculiar thereto, and not As rovnded pebbles and indicating an alluvial origin to these clays: I thought these coiiclu- gions well warranted by the regular beds of which this clav in many places consists; its regidar layers of Indus helmonti ; the uniformity in the shape of its chert pebbles, many of which appear concentric in their structure, and by their having an external coat or covering, which is nearly simi- lar in all of them: but an able student undcr>Mr. Williaiu Smith, of the same standing with myself, Mr. Benjamiii Bevan of Leigh ton Buzard, Beds., whose situation as engineer to the Grand- Junctio!! Caa*il Company, has for some years past given liim better opportunities of examining the north- ern edcic of the London clays than I have possessed, has for some time held the clays and sands above the chalk to be alluvia, and produces instances of chert pebbles taken from their bed on Rislip-common, Middlesex, in a pit uherb sand containing layers of ihese pebbles has chalk in its bot- tom, to piove these pebbles to have been rounded, and even some oF them to have been broken and since partially rounded (which is perhaps the most unerring test of round- ing, that we nieet with). It has also been suggested hy this gentleman, triat the peculiar dark-coloured and uneven coat of these pebbles, is occasioned by a partial decomposi- rion which they liavc sufi'ered, since their rounding, the cfieets of which are also visible in the concentric stains within many of them, which give them so very nearly llie appearance of original nodules. In candour 1 ought also to state, that the accounts which I have collected of thi; sinkings iS8 Geological Remarks aa the sinkings of various new wells, (on sonve of which I have been consulted) near the metropolis, have exhibited less of rtgularitv in the succession and thicknesses of the strata, than I had been led to expect: also, that at Alford in Lin- cohishire, where numerous very shallow wells are sunk and holes in them bored, through this clay and the sand under it into the chalk, from whence the water rises and perpe- tually overflow's the surface, I fonnd this clay and sand niuch thinner than it usually is about London. It is my wish, to suspend entirely my opinion on the above interest- ing questions, until many more facts are collected, and especially until the situations ofour principal assemblages of fossil shells above the chalk at Hordel, Reading, Woolwich, in the shell marles of Suffolk, &c. he. are ascertained, and they have been examined and minutely described by a com- petent conchologist^ and. such descriptions have been care- fully con) pared with tho^drawings and details by our author* and M. Lamarck :, an; undertaking which 1 wish nmch to press on the innncdiate attention of the societies above mentioned. If no part of the qhalk be elevated more than 50 feet above the Seine (p. 43), it should seem probable, that the 50 chalk fossils mentioned (p. 42) belong to about only one-eighth of the whole thickness of the chalk strata, at its top. In commencing a very extensive Mineralogical Survey, like Mr. Smith's manuscript Map of England, Wales, and part of Scotland, it will perhaps be best to foliow his exam- ple, in selecting only such strata as usually form distinct ranges of hills through tlie country, by their bold or sudden endmgs, to form his classes or principal assemblages of strata, that are to be distinguished each by a different co- lour in his Map and Sections, without much regarding the mineral characters, or characteristic fossils of the several thin strata that compose each of them, leaving these to be enumerated and described in written details and in local sections on a large scaler In commencing more local, but yet considerable surveys, such as my square of map includ- ing Derbyshire, or the basin of Paris, the bold endings of particular strata ought 1 thinlv still to have a principal share in determining the selection of such as are to have a difier- cnt colour assigned to them; the other considerations slu^uld be the width or extent of surface which is made by the se- veral strata, and the distinct mineral characters of particular thick strata or beds: a few thin beds or strata which hap- pen t«j have very striking character^ cither in their appear- ance. Siratification of France and England. 139 ance, economic uses, or conspicuous fesils, may have a colour assigned tliem^ especially if such Fall between, and not so as to subdivide thick masses, selected for separate soils, or fi^enera on the principles 4ibove. In coaf-districts or others, where grit or limestone alter- nate with argillaceous strata, it will be found right perhaps, to select all ihe thick masses of rock, which are sufficiently separated by clay-shists and other argillaceous strata, to have diflcrent colours assigned thcni, either using some general colour for the clays formed on the surface by all the argillaceous strata, or assigning a colour to each of these aroillaceous assemblages, according to the number of the strata and thicknesses of them, so that the map be not over crowded. The transitions frc^ni light to heavy or dry to wet latul, made by the above two classes of strata, are the best deHu(;d characters that we meet w ith in mineralogical sur- veying ; and arc indeed almost the only ones by w hich the fanners and occupiers of the lands can give any assistance by their information, except while pacing over every part of the surface with the surveyor, in answer to his questions, as they may arise. The plan which M. Cuvier and M. Brogniart seem to have followed, in assigning colours to their soils (p. 41), and dividing some parts of the Paris strata into their ten forma- tions or soils, seems to me much inferior to the above ; and in particular their sea sands, freestone without shells, and fresh-water soils, appear calculated to lead to no useful re^ suit, but rarher to mislead. The more popular and obvious the divisions of the strata are made on mineralogical maps and sections, the sooner will the geological facts thev con-* vey be understood and rendered useful ; for after all that can be said, they must, in the present state of our know» ledge at least, be but arbitrary classes or divisions, exhibitiuc'' the order of super-position, principally. llie freedom of the remarks v.hich I have ventured to make on the opinions and writings o? geological observers of such high celebrity, will J trust in candour be ascribed to their true motives, — a desire to render justice to a valuable friend and to our c'oimtry, and to advance and perfect the science; which of all others seems to me to claim our seri- ous cultivation and attention. An apology may perhaps be necessary to your other correspondents and readers for the great number of your valuable pages which I hav^e occupied. I am, sir. Your obedient servant, John Fa uey. FeVriiarv !?.rh, IRIO, l^a. 12, Upper Crown-street, Westminster, n [ I'io ] 'XX. Bcpurt on a vew ,Naingalle Canal proposed to he cut from Okaluwi to Stamjord^ and from ilience to llwToLvn of Boston, i?y Thomas Tkifobd, Esq, JL HE gcnllcnien of Lincoln and Rutland having for some time been turning their attention to the diseuvery ol the best means for extending and iniproving the benefits al- ready resulting from, inland navigation, in such a manner that the greatest local advantages to the town of Stamford niay be imitcd \v;itb the general increase of the agricultural and commercial prosperity of a large district of surround- ing country, and having employed Mr. Tel lord to take a view of the dilferent lines (;F country embraced by their plan^ have received the following RLrORT. *' Having, in compliance with the directions of the committee, carefully exan}ined the districts of country, ex- leiiding from Stamford westwardly to Okeham, and east- warciiy to Peterborough, Spalding, the Foss Dyke, and Boston j — I shall slate my ideas with regard to the sundry lines of inland navigation, which appear best calculated to promote the most perfect intercourse, and, consequently, the general prosperity of the country. " The whole of Leicestershire being already intersected from north to gouth by an inland navigation, and also from west to east by a line of canal, passing by Melton Mowbray to Okeham in Rutlandshire j there now only remains to be considered and determined, the most ad- viscable mode of proceeding from the last point, eastwardly, to the ports situated upon the great bay or inlet, called the ^Vash ; and thereby opening a direct and commodious communication with a point on the east coast, nearly cen- trical between the Trent and the Thames. " The town of Okeham, at which the last- mentioned canal terminates, being situated upon the summit of the ridce of land which occupies this part of the country, ani from which the adjacent streams have their course to the river Welland, aflbrds an opportunity of choosing a line of canal, either dowy the river Wash, or Gnash, which falls into the river Welland, about a mile and a half below Stamford bridge ; or down the river Chater, which unites Avilh the Welland about two miles and a half above Stam- ford. ^* Th& river Wash, occupving the valley nearest to tliC Report on the proposed Okeham and Boston Canal, 1 4 1 the town oF Okehani, bas induced Mr. Whitworth, in his survcv, to follow that stream to its junction with the Wcjiand ; but by that line, though sufficiently regular in its descent, being obliged to skirt the north side or the high ridtze of land which lies to the north of Stamford, an awkward circuity is created before it can reach the town, so that the distance by the navigation between Stamford and Okehani would be nearly nineteen miles. " In proceeding from the sea-const to the interior of the country, the vessels navigating that line must either pass at the distance of about one mile and a half from Stamford ; or having come up to the town, nuist return the same distance, along the same line, to get into the valley of the Wash. " These circumstances, in my opinion, render that line objectionable, and inferior to another line which may be ob- tained by means which Mr. Whitworth has himself partly- pointed out. This is by continuing the head level from Okeham over the south field, along the before- mentioned line, about -a mile and a quarter from Okeham ; and from ihence, instead of locking down the Wash valley, to conti- nue through Egleton iiuo Gunthorpe, and there locking down to reduce the embankment across the Wash valley, so that the cutting through the ridge, at Maninsthorpe, shall afford earth sufficient for its construction. This will enai^le the line to be carried into the Chater valley,, without being encumbered wiih a tunnel, which Mr. Whitworth, from a tursory view, apprehended necessary. The valley between Gimthorpeand Martinsthorpe will also be a convenient place to receive the feeder from the reservoir proposed to be formed at Braunston. " This line, having crossed the ridge at Martinsthorpe^ should be locked down nearly to the bottom of the val- ley of the Chaier, and be carried down the north side to near Kclion, where, in order to avoid the village, it should cross lo the south side of the valley. After passing the village, it itiust be again brought to the north side, and be contmued to the mcist favourable point for crossing the river Welland, below where the Chater has fallen iiUo it» After crossing the Welland, the line should be carried along the skirts of the vvood, as nearly as possible, in the di\ i.-^ioii between the uplands and the meadows, and it should fall into the river above Stamford bridge, in the most ccnive-f nient way, to enable wharfs to be formed on each side of the river. For accomplishing this object the opportunities ^re ample, without interferini^- with buildings. I prefer th(» * south 142 Report on the proposed Okcham and Boston Canal* south hank of the river Welland/ from near the junction of the Chater, because it is more favourable ground for a canal than the north bank-, which is composed of loose rock; and bc^^ause, if the proposed hne to Harhorough be executed, the last-mentioned t\vo miles and a half vould answer the purposes of both navigations. The length of tlie line between Stamford andOkehani, as near- ly as I can at present make out, would not exceed ilfleen miles, being shorter than the line laid down by Mr, Wliitworth by four miles. ' Besides that this line arrives nt Stamford from Okeham by a shorter distance than the other, it will be more satisfactory to the principal land- owners in the county of Rutland ; it bears more equally upon the general population of that county than the other does : and it will for ever fix, more directly, the inter- course by inland navigation through the town of Stam- ford. ** Proceeding from Stamford towards the sea coast, it will be necessary to continue upon and improve the present jnavigation of the Welland to the second lock, being a distance of about three miles ; buf from thence to the sea, it will cost more to render the old navigation perfect, and acquire a proper outlet to the sea, than will construct an entirely new canal navigation to the town of Boston. *^ I am therefore of opinion, that, at or near the se- cond lock, a line of canal should depart from the north bank of the Welland, and, — passing along a line between the uplands and the nieadows to the westward of Tailing- ton, and inmiediately eastward of Barholm, to the west of Kate's Bridge, — it should enter the Car Dyke, along which it should be carried, until that ancient work ap- proaches the South forty-foot drain; and opposite Billing- borough, or llorblinii, and then should proceed along that excellent drain, to , the town of Boston. *' From the Welland to Car Dyke, an entirely new canal must be formed. Its parsing, as much as practicable, be- tween the uplands and meadows, will be favourable to the adjoining properties, and afford irood ground for the ne- cessary works. Along the Car l5yke, in many places, it has been preserved as a drain, and will beconve a part of the proposed navigation. It will then also form a more perfect bountiary to the fields which have always been sepa- rated by it, and when thev are accommodated by necessary bridges, the adjacent properties will be much improved. Along the South forty-foot drain, with the exception ©f deepening Us bottom from half a yard to two feet, and widening Beport on the profKtsed Okeliam and Boston Cav/il, 143 widening the lock at Boston, to suit the breadth and draft of vessels which navigate the liciccstefshire canals, very lit- tle more is required to render it an excellent navigation. '* By the canal, line being carried along the Car Dyke, it will not at all interfere wiih the navigations ol" the rivers Glen and Bourne, because it passes above the places where those navigations terminate : and as the waters of those rivers will be passed under the canal, no apprehensions can be entertained that their usual supplies will be lessened. *' The river Welland cannot be injured, because, during winter and rainv seasons, the superabundance of water will be more than sufficient for all purposes: and, in dry seasons, as the supplies of water for this navigation are proposed to be drawn from reservoirs situated near the -summits of the country, they will be passed through locks in the upj)er country, whicF\ are at least double the , depth of those in the lower country, so that unless there is more than double the quantity of business in the Fens, to what is carried through the upper country, no additional water can be required. Besides, the leakage from the upper locks will be much more than from the lower ones, consequently the surplus water must fall into the Welland, ** The South forty-foot drain proprietors will have no apprehensions of too great increase of water, in their drain, when they consider the interest the canal proprie- tors will have to preserve their water, by constructing very shallow and perfect locks, and by adding to this, the great extent of surface each lockfull has to spread over, and the regulation which will constantly be taking place by the lock at Boston. '' The conservators of the port and haven of Boston, besides the certain prospect they will have of increasing the prosperity of the place, must be sensible of the evident advantage of deriving additional supplies of water to assist in scouring out and maintaining the bed of the river be- tween Boston and the sea. ** The communication between Stamford and Boston, by passing along the line of division between the Upland and Fen countries, where the most populous market towns and villages are situated, will (exclusively of the thorough trade) be of great advantage to all the district of country through which it passes, and afford adequate tonnage dues In return ; so that, upon the whole, this ap>pears to be an improvement \vhich will be generally beneficial, and will interfere, as little as possible, with any established rights. " In order to render th.e inland navigation of this di- strict 144 Reporl on the proposed Okeham and Boston Canal, strict uf country, and the connections with the interior districts more perftct, and to afford a lair competition of local advantages, I am of opinion that a canal should be carried between the Welland and the Neno : and the coun- try appears to be ])articularly favourable for this junciion. Tins hne should de{)art from the Welland precisely where the branch to Boston does, and in a manner similar thereto. It should be carried m a line dividing the upland from the flat country, and terminating at or near Peterborough, By these means, tl)e elevation would be small ; atid proper ground would be obtained for the canal works : and the canal, being supplied with waters, which now pass partly into the Welland and pauly into the Nene, those waters would be turned by lockage to the respective rivers, so as to Injure neither. The country through which the canal would pass is very populous, and requires conup.unication : and the towns, and whole population of the valleys of theW^el- land and the Nene, would thereby have an Ojiportunity af- forded them to benefit by the navigation of all the rjvcrs which fall into the great bay — with the choice of such of them as should best suit their interest and convcniency, " Having, I trust, stated satisfactory reasons whv the former surveyed line of canal should be abandoned, and having hitherto been enabled to recommend other lines only from a 2:c"^'»'cd inspection of the country, the committee will readilv conceive, that, until regular and careful surveys and sections have been made, of the new lines, it is im- possible for me to enter into a more minute detail, either with re^^ard to the precise situation f)f the lines, or the na- ture of the works required, or to form any correct estimate of the expense. But if it be judged adviseable, after this general explanation, to authorize me to proceed in getting these surveys and sections made, no time shall be lost iu perfornnng the service, and furnishing the committee with all nece;3sary data lor making an application to parlia- ment. " In the mean time, I may venture to slate, that althon2;h from the quantity of lockage necessary to ascend to the canals, already made upon the sumnlit of the country, the expense of the line from Stamford to Okeham wdl be fuilv eq*al to the general average of canals of similar di- UKusion? ; yet those from Stamford towards Boston and Peterborough, from their sniall elevations — the favourable Ijiuure of the ground-™-and fre ereatlv On Crystallography, 143 greatly under the general average of expense ; so that, upon the whole scheme, (embracing an inland navigation of from CO to 70 milesj) taking into view its extensive connexions, tiiere appears a fair prospect of ample remuneration for the adventurers. Thomas Telford. Stamford, 8th Jan. 1810. In consequence of the foregoing Report, it was resolved^ at a meeting of the committee held at Stamford on the 8th of January, 1610,— -That it appears to this committee to be impracticable to go to parliameni in the now ensuing Session for the sanction of the legislature to the plan which Mr. Telford has proposed, in.Wnuch as the necessary sur* veys cannot be in due time prepared, nor the notices given> nor the plans delivered, which are recjuired preparatory to the mtroduction of navigation bills into parliament : but that Mr. Telford be directed to take the steps proposed in his report, and that every other proper measure be pursued for the introduction of the bill into parliament in the session following. XXI. On Crystallo^rap/iy, By M, Hauy. Translated from the last Paris Edition of his Traite de Mineralogie. [Continued from vol. xxxlv. p. 466.] If these ridges were subject to a different law, which gave rise, for example, to sublractions of two ranges, the sign 'i L'-O would become De E P B ^. According to this it has been considered as settled, that the decrements represented by a large letter accompanied by any cypher would not implicitly contain similar decrements represented by the small letter of the same kind, or vice versa, i. e. for example, that B would not implicitly contain by or, vice versa, that when the second letter would not enter into the expression of the sign with a difterent cypher, we should not use the same cypher accompanied by a zero. In the first case each of the two letters expresses a decrement which is peculiar to the ridge or to the angle which it indicates ; in the second^ that which is affected T)y a zero shows that the angle or the edge to which it exclusively relates undergoes no decrement. Thus eEPBZ', B expresses a decrement by one jange, which only takes place on the ridges contiguous to the upper summit A (fig. 73) ; b indicates a decrement by Vol. 35. No. 142, Feb, 1810. K two 14(5 On Crystallography. two ranges, which only acts hi the same way on the ridge* conliguoas to the lo\ycr summit. Finally, the quantities e and E ouglit to be thus considered independently of eack other ; the first as expressing a decrement by two ranges on the angles e solely, and the second as indicating zero of decrement, on the angles E opposite to the foregoing. I have enlarged on the detail of the principles of the me- thod, in order to leave nothing to be desired, if it were possi- ble, of what can be of use in enabling my readers to have a clear idea of the art, and put an observer in possession of the method of instantly representing a secondary crystal of a given form. But if any person confined himself to the simple comprehension of the signs employed in the system, and was only anxious to read without being able to write them, he would only require some simple and easily under- stood rules, which we shall here succinctly explain ; — they will form a kind of recapitulation of the preceding details. 1 . Every vowel employed in the sign of a crystal designates the solid angle marked with the same vowel on tl>e figure which represents the nucleus ; and every consonant indi- cates the ridge which bears this same consonant, or the face the middle of which it occupies. 2. Every vowel or every consonant is accompanied by a cypher, the value as well as the position of which indicates the law of decrement which the corresponding angle or edge undergoes. We must except the three consonants P, M, T, each of which, when it forms part of the sign of a crystal, indicates that this crystal has faces parallel to that which bears this same letter. 3. Every letter comprehended in the sign of a crystal i& marked below with ihe cypher that accompanies it, on all tho angles or all the edges which perform the same function with that which on the figure is marked immediately with the letter in question. 4. Every number added to a letter indicates a decre- ment, the angle or edge of which marked with this letter is the term of departure. If the number be entire, it indicates iiow many rows are subtracted in breadth, with the condi- tion that every lamina has only the thickness of one mole- cule ; if the nmiiber be fractionary, the numerator makes known how many rows are subtracted in breadth, and the denominator how many are subtracted in height. 5. According as the number is placed below or above the letter which it accompanies, it indicates that the decre- ment OnVnjstallography» 147 Ittent descends* or ascends, setting out from the angle, or from the t(\g'^ marked with this letter. If it be placed to-» uards the top and to the right or left of the letter, it designates a decrement which takes j)lace in the lateral di- rection to the right or to the left of the angle which bears the same letter. 6. When a letter is found written twice successively with the same cypher placed on two different sides, such as ^G G% or G* «G, ^A A% or A^ ^A, the two edges or the two angles which it designates, ought to be considered on the figure according to the same relative positions, i, e.^ for example, as in the sign ^G G% the quantity ^G indi- cates the effect of the decrement on the edge G situated on the left, and the quantity G^ the effect of the decrement on the edge situated on the right. 7. When a letter bears the same cypher repeated both on the right and left, as ^G% it is applied indifferently to any one of the ridges G which it designates. It is the same \('ith the letters which belong to the angles. ^ 8. The parenthesis in such as (OD' F^) designates an in- 3 termfidiary ,diecrement. The letter O expresses in the first place, that the decrement takes place by three rows on the angle O, and that its effect is ascending. JD ' F^ make known that for one rid2;e of molecule subtracted along the side marked D, there are two ridges subtracted along the side marked F. 9. Every small letter comprehended in the sign of a crystal, indicates the angle or edge diametrically opposite to that which bears the large letter of the same kind, or the figure in which the small letter in question is omitted as su- perfluous. We must except the letter e, which is always employed on the figure of the rhomboid, and which indi- cates, according to the principle, the angle opposite to that which bears the letter E. 10. When a sign contains two letters of the same kind, the one large and the other small, with different cyphers, the two opposite edges or the two opposite angles to which these letters answ^, are considered as each undergoing ex- clusively the law of decrement indicated by the cypher added to the letter. * We only allude hereto thegdneral progress of decrements, to which the particular cases refer that seem to form an exception. For instance, if the decreaient be produced by one row on the anjjie at the summit of a rhom- boid, then the face produced will he horizontal. But this, decrement com^s within the description of those that are descending, and of which it is as it were the limit. K 2 11. Every i 4 8 On Cnjstallographtf, 11. Every letter, whether large or small, marked with a cypher which has a zero after it, shows that the decrement indicated by this cypher is null on the particular angle or edije to which this letter refers. We have omitted the applications which would be neces- sary for understanding these rules, if they had been pre sented on our first setting out. These applications are found already in the detailed explanation, which we have previously given, of the principles of the system, and the perusal of which is presumed to hare preceded that of these same rules. OF INDETERMINABLE CRYSTALLIZATION, When the crystalline molecules disseminated in a liqiiid experience obstacles which affect their tendency to reunite in conformity to the laws of their mutual affinity, the forms which result from their aggregation have no longer that regularity which belongs to an exact and precise deter- mination. Their ridges are obliterated, their faces are curved, tlseir pyramids are sharpened. Hence the crystals called lenticular, or which imitate the form of a lentil ; cylindroids^ the prism of which is rounded off^ acicular, or similar to needles ; Sec. If a multitude of small indeterminable crystals are so in-- timately connected with each other that they form only one body, we then consider this body as a particular being, and hence the substances which we call striated, fibrous, he, and which are formed by the junction of an infinite number of crystalline needles, sometimes parallel, some- times divergent, and at other limes crossing; in different di- rections. Lastly, The appellation amorphous hs^shetn given to sub- stances which present, as it were, the last degree of con- fused crystallization, and the vague and indefinable form of which is, as it were, mzite to the eye of the observer. Of CoNCR.ETfONS. — ^The formation of the bodies which we have hitherto mentioned, particularly of crystals pro- perly so called, essentially depends on two conditions only : one of which is, that the molecules of these bodies should be in the state of integrant molecules ; and the other, that they should be kept in suspension in a liquid capable of abandoning them to the attraction which solicits them to- wards each other. In short, every thing is regarded as passing in the same manner as if, the force of gravity being null, the liquid was not coerced by the sides of any sur- rounding waiter^ and as if the crystal iiself remained iso- lated On Crystallography* 14 ^ lated in the liquid, without having occasion to be sup- ported. This is not the case with the bodies which we are now about to consider. The modifications which they present are owing to certain local circumstances, such as points of attachment, props or moulds which influence their form. We unite ail these modifications under the common de- nomination of concretions, which in the ordinary accepta- tion signifies a congealed or fixed substance. But in order to fix in a more precise manner our ideas on this head, we shall comprehend under the term concre- tion^, the different bodies, the aspect of which depends, partly at least, on their molecules being in contact with other bodies. We shall now give an idea of the various circumstances which contribute to vary this appearance. 1. Stalactites, The water which filters into the fissures of stones situated in the arched part of subterranean cavi- ties, or which oozes through the lax and porous texture of these vaults, arrives at the surface after hollowing out ccrtaiil stony molecules which are united to it in any way. The drops which remain suspended from the arch during a cer- tain time, undergo a desiccation, which commences on the external surface -, and the stony molecules which the li- quid gets rid of, exerting their attraction on each other, and attracted at -the same time by the side of the vault which they adjoin, form in this place an initial tube, or kind of small ring. This rudiment of tube increases and grows longer by the intermedium of other drops, which succeed to the first, conducting new molecules which th^ orifice of the tube attracts in its turn. Sometimes this tube preserves the form of a hollow cylinder, similar to a quill. But frequently it increases in size, and is enveloped with concentric layers, the matter of which is furnished by the liquid which descends along the external surface. . It then becomes a thick cylinder or cone ; and sometimes the mo- lecules iTollowed out by the drops which thus flow into the interior of its canal, finish by obstructing it entirely. These different modifications are peculiarly sensible in bodies which belong to carbonated lime. But a part of ^he liquid, on falling from the arch upon the ground, forms there other depositations composed of strata generally undulated, or protuberances, the figures of which vary ad infinitum. Lastly, the liquid which flows along the lateral partitions gives rise to bodies, tiie form of which w^e might compare to that of a drop of congealed water, K 3 Stalactites 1 50 On Crystallography, Stalactites are those bodies which are formed in the arch of the vauh ; and stalagmites are those which originate from the falhng of the hquid on the ground. It is, how- ever, much mit)re convenient to call both stalactites, as it is sometimes difficult to distinguish between the two kinds of formation, when the bodies under consideration have been removed from their original position. 2. Iiicr7istationSj In the preceding concretions, the aggre- gation of the molecules depends more especially on the evaporation of the liquid which has flowed over them. Other concretions, which have been called incrustations, iufs, and si?itcrs, proceed from a kind of precipitaticm of the molecules originally suspended in the liquid. The latter are sometimes deposited on the surface of different organized bodies, particularly on those which belong to the vegetable kingdom, and sometimes cover .the inside of certain bodies, such as sewers or drains. When the liquid is introduced into a subterranean cavity of small dimensions, ^ where it can remain, the stony mole- cules incrust the sides of this cavity, which is generally of a round form, and sometimes end by studding it with crystals. This IS what has been called geode. Some of these bodies contain a solid and moveable nucleus, or a pulverulent earthy matter* ; of this description also are certain pieces of silex found in marie. Sometimes also the geode is en- tirely filled with a matter which may be distinguished by the naked eye from that of which it is itself composed. It may also happen that a substance may be incrusted with crystals of a different nature, by being as if moulded along with them. For instance, we are acquainted with crystals of metastatic carbonated lime incrusted with quartz, and sometimes the quartzous envelope remains empty after being separated from the crystals which it concealed. 3. Pseiidomophoses, There exists a third order of concretions which we call pseudomorphoses, i. e., bodies ■which have a false and deceitful figure ; because the sub- stances which belong to this order present in a very remark- able manner foreign or strange forms, which they have in some measure obtained from other bodies which had re- ceived them from natur^. ' ■ When the type of this apparent transformation is a shell, it happens frequently enough that the shell still covers in whole or in part the substance, which is as if moulded ♦ It is probably from this that the term geode is derived, i. e., a body Vhich contains earth, into On Crystallography. 1 5 1 into its interior*, and then nothing appears simpler than the explanation oF the fact, by the introduction of a liquid charged with stony molecules into the cavity of the shell; and this observation leads to a similar explanation of the formation of the kinds of nuclei modelled into shells, which we meet with isolated and stripped of every envelope. Sometimes the shell itself has been penetrated by another matter sjenerally siliceous, which has been subsiituted for the cartilaginous substance of which this shell had been partly composed f; and it may happen in this very cast> that the interior of the shell has remained empty. It is no longer, properly speaking, a pseudomorphosis. It is a fossil which has merely become n)ore stony than it was before. This last kind of modification takes place equally with respect to the bones and to the other solid pans of animals which are found immured in the bowels of the cartfi ; i. e., they may pass to an almost entirely stony state; hy the help of a substance which supplies the place of th^^ir cartila- ginous part. The case cannot be the same with vegetable productions as with shells. They have no testudo, or envelope, which can exist after the destruction of the interior substance, and serve as a mould to a stony or other substance for re- ceivifLig an impression of their form. If we supposed that one of these productions, such as a portion of the branch of a tree, were entirely destroved, so that the cavity which it occupied in the bowels of the earth remained empty, we could conceive that a stony matter might afterwards fill thi^ cavity and there be modelled to it. In this case the new body would resemble externally the branch of a tree; it would have the appearance of knots and wrinkles, but its inside would not present any trace of organization, and it would only be, as it were, the statue of the vegetable production, which ;t would have displaced. What is generally called petrified wood is a much more faithful imitation of real wood. On a transverse section we distinguish the appearance of concentric layers, which in the living tree must have proceeded from its increasing in thickness; all the principal lineaments of organization are preserved to such a degree, that they sometimes serve tor* enable us to ree6gnize the spocies to which 'the tree be- longed which has undergone petrifaction. * De risle Crystall. tome ii. p. 161. f We know that shell?, as well as the bones of ani'mals,'are formed of two substances; the one calcareous, whiclj is not susceptible of patrefnction ; the other cartilaginous, membranous, or flashy, whicii may beflearroyed Uy fcfipentation. . " " K 4 Among 152 On Crystallography, Amon^ the, different explanations which have been given of this pYviienomcnon, that which seems \o be nio:^t gene- rally admitted, although not exempt from objections, con- sists in supposing that the stony matter is substituted for the vegetable in proportion as the latter is decomposed; and because the substitution take* place succcasivcly, and as it were molecule by molecule, the stoin' panicles, in arranging themselves in the places rendered empty by the disappearance of the ligneous particles, and by moulding themselves into the same cavities, take the impression of the vegetable organization, and :;opy the traits of it precisely. The mineral kingdom also has its pseudomorphoses. We find some substances of this kingdom under crystal- line forms, which are only borrowed ; and it is probable that, in some cases at least, the new substance has been substituted gradually for that which has ceded its place to it, as we suppose takes place with respect to petrified wood. The various pseudomorphic bodies imprint their form on the matter which surrounds them, and frequently also the impression serves as a cell for an organic substance which is simply in a fossil state, or which has received a certain degree oF alteration only. This takes place in particular with respect to the ferns and other plants of the same family, the form of which is moulded on a schistous matter, as we shall afterwards more fully detail. We generally denominate petrifactums all the variously modified substances which we have mentioned, even those which' only present impressions of animal or vegetable productions. Daubenton applies this term only to bodies which, in their natural state, being partly stony and partly cartilaginous, such as shells, have become entirely stony. As we merely purpose to mention a few examples of the ipiodifications in question, and not to unite then) methodi- cally under one aqd the same point of view as several authors have done, we shall confine, ourselves to the enunciation of some of them in speaking of the substances which have formed their secondary matter, and shall adopt the no- menclature to this method of classifying. We ought not to omit that there are also pseudomor- phoscs, which, arise from the substitution oF a metal in the room of an organic body. Sulphurated iron presents se« vera! examples of this kind of metallization. By referrmg to all that has preceded, we may define in the followiiig manner the different concretions of which wc have given the description : — • The On Artificial Slone, 153 The stalactite is a concretion composed of successive layers of a circular or undulated form, which is the effect of desiccation. The i?icrustation is a concretion in the form of a crust applied to the surface or to the interior of a body. To this we may refer the geode, which is a concretion in the formof an envelope, spherical or nearly so, sometimes empty and sometimes containing a nucleus. The pseiidomorphQsis is a concretion endowed with a form foreign to its substance, and for which it is indebted to its molecules filling a space formerly occupied by a body of the same form. [To be continued.] XXII. On a Hard Artificial Stone that generates a consider rahle Quantity of Heat during its Consolidation; with the Application (if this Fact to the Cause of Volcanic Fires*-, X HE artificial stone about to be described presents a re- markable example of the great degree of solidity which water, in certain combinations, can acquire. Water forms more than half the weight in the composi- tion of these stones : the other ingredients are one part of sulphuric acid, and two parts of burnt clay (bricks or earthen-ware) reduced to powder. The mixture of these substances yields, in fact, a solutioa of sulphate of alumine : but when in the mixture circum- stances are favourable to their reciprocal action, heat is speedily produced, and the quantity evolved is sometimes so considerable as to produce ignition in the mass. If from 25 to 30 hundred weight of materials be em- ployed, this extraordinary phaenomenon lasts for more than an hour. The most remarkable circumstance is, that if no water be added to the mixture, when the reaction of the sub- stances upon ench other is the strongest, themas$, although still liquid, suddenly acquires a great degree of solidity: the heat which jt produces is augmented, and the substance afterwards becomes almost entirely insoluble. This last property being acquired by a mixture calculated to yield ver) soluble salts, |)roves that there is a great pene- tration of the earth by the water and acid, as the whole jiiass forms a stony composition only. • From M. dc la Mcthc-ric's Journal df. Physuiuc. Tht 1 54 Koyal Society, The stories here all u Jed to, although apparently pos- sessing all the properties just described, are not inso- luble : they were prevented from acquiring that state, as they would then be useless. But as this composition, witlj the exception ot its insolubility, has all the external cha- racters of the hardest stones, it possesses^ some claim to atteniion. Might it not, after having been softened by a heat superior to that of boiling water, he employed with much advantage as a cement, or to cast into models of statues or vases, &c. ? Bodies formed of this artificial stone must be protected, however, from the influence of water or moisture. What also contributes to the inlcrcst excited by this com- position is, that its analogy wiih the stones of solfaierra, and the peculiar theory of its formation, will not require lis to recur to the hypothesis of subterranean fires, to ac- count for volcanic eruptions. In short, as water, by merely passing in an instant from the liquid to a solid state, develops sucli a considerable de- gree of heat, may it not be the inunediate cause of volca- nic eruptions ? May it not also be to the slow and progres- sive passage of water to the solid state, that the heat found at great depths in the interior parts of the jzlobe is owing ? Lastly, Mav not the heat developed in the animal and vege- table organs be also owing to water? The above suggestions are thrown out with a view to call the attention of chemists, mineralogists, natural philoso- phers, and physiologists, to a subject which cannot fail to derive much lio;ht from their concurrent observations. XXI 11. Proceedings of Learned Societies, ROYAL. SOCIKTY. X HIS society on the 1st and 8th of February was occu- pied with reading a letter from Mr. Gibson of Manchester to Mr. Thomas, describing an extraordinary foetus, having two heads, only one body, two arms, two legs, and of both sexes. There was nothing in the physical organiza- tion of this monster which could apparently have impeded the vital functions; its two heads were perfectly formed and joined side by side, that on the right being masculine and that on the left feminine ; both were united to one gpine 3 and' although it had two hearts, only one stomach was Society of Antiquaries. 155 was found. Th^, nerves from the head on ibe right side passed to the right arm and leg ; th<>se on the lett to the left arm and leg ; so that, had the creature lived, one head and mind would have directed the right side, and the other the left. The organs of the two sexes were very distinct, and the uterus was found in the bladder of the male. The author described the physical structure of this lusus naturce. very minutely, but the details would not be interesting. Feb. 15. A paper on uric acid, by Mr. Brande, com- municated by the Sociely'for improving Anin)al Chemistry, was read. The author related the etiects of the alkalies and linie on the uric acid and phosphats, in patients la- bouring under the influence of calculi, but in none of the four cases which he stated were they successl'ul in giving relief or curing the disease. JN'lagnesia, however, had the desired effect, and brought oft' in the urine great quantities of uric acid and phosphats, in the form of triple salts. The discharge of these salts, after taking small closes of magnesia, was so copious, that ihe patients were radically or effectually cured in two or three weeks. The suggestion to use njagnesia was made by Mr. Hatchet, who knew of nothing so capable of acting on uric acid, and experience has confirmed his conclusion. Feb. 22, In consequence of the indisposition of Sir J. Banks, Mr. Marsden was in the chair, when the reading of a supplementary paper, by Dr. Flerschel, on coloured concentric rings, commenced. The present object of the author is to explain and elucidate the positions laid down in his former papers on this subject, and in some measure to insure to himself more completely the sole me- rit of discovering the red bow, as Newton did the blue one. The introductory remarks chiefly referred to the 42d and 43d sections of the author's preceding paper, in which the nature of the red rings, the transmission of light, and the prismatic colours, were particularly discussed. The con- clusion of this paper was postponed till next meeting. SOCIETY OF ANTiaUARIKS, Mr. J. A. Repton presented to the society a scries of de- signs of wooden houses, windows, or other parts of buildings constructed of wood, in order to show the .origin and pro- gress of architecture in wood throughout England. His views included the principal structures of tjinber in London, Essex, Suffolk, Norfolk, and Lincolnshire. In the expla- natory observations which were read to illustrate the views, i( was stated that sash-windows were not introduced into this 156 IVernerian Natural History Society, this country till the age of Charles T., anrf that they did nof become general before the beg'mning of tlie last century. The sashes were originally constructed of very thick timber, and the joinings were left in square pieces in order to add 10 their strength, as it was then believed. As an appendage to these views, the design of Melk- house-street, a curious old rustic building, entirely of tim- ber, near Ashford, Kent, was exhibited to the society. 'J'hc drawing was fexecuted by the late F. Grose, and pre- sented considerable variety in its architectural ornaments. The design was made in 1 7C0, and has not yet been en- graved. WERNERIAN NATURAL HISTORY SOCIETY. At the meeiine: of this society, on Saturday the 13th of January, the Rev. Dr. Macknight read a mineralogical ac- count of Ben Ledi, and the environs of Loch Ketterin. The description of the rocks in that district (which consist of mica- slate and clay-slate, with an overlying conglo- merate, formed at a lower level from the debris of primi- tive mountains) tended, in the author's opinion, to illus- trate one branch of the Wernerian doctrine respecting the order of formations in the mineral kingdom. It alL>o ap- peared, in confirmation of another principle in the Geo- gnosy, that the direction from SVV. to NE. of the strata composing the Highland mountains, corresponds to what has been observed in general relative to the bearings of the primitive strata in the crust of the earth. Such an imiformity of direction, it would seem, could have resulted only from the action of powers in nature that are slow and regular in their operation; and must be referred to some original law, which later discoveries render it probable may be found to depend on the constitution of the terra- queous globe in regard to magnetism and electricity. At the same meeting the secretary laid before the society a communication from Mr. William Scoresby junior, of Whitby, comprising a meteorological journal of three Greenland voyages , with remarks on the ctrecls of the weather on the barometer in Greenland, and on the diflTercnt crystallizations of snow to be observed in high latitudes. XXIV. Ih cm] X^^^IV. Intelligence and Miscellaneous Articles, ON PROCURING AN EaUAL TEMI^ERATURE, To Mr. TillocL Sir, vJn accidentally looking over a volume of the Me- dical Journal For 1801, I found a short but pleasing account of the effects of the climate of Madeira in cases of pulmo- nary tubercles. The communication is. dated in January in the above year, and is addressed by Dr. Adams, then resi- dent in that island, to a medical friend in this country. It concludes wijh the following suggestions ; — *' These are, I believe, the principal inquiries you wished to make ; — it is true they are of little consequence compared to the in)por- tant fact you have in view, ft is however satisfactory to trace probable causes, and it may be luell worth your while to try whether spacious buildings, regularly heated^ -Srt/e^ ventilated, and large enough to admit of necessary exercise, may not answer the purpo'ie Jor such ivhose want of means, of courage, or of leisure, prevents their taking a voyage to a, more genial climste." It r?; not my wish, by sending yon the above, to detract from the claims of Dr. Pearson, with ^A/hom the same idea seems to have originated : perhaps that truly respectable practitioner is noX even aware of the existence of the passage m question. It is but fair, however, that the claims of others should be recognized, when the public, as in the present in- stance, begin to reap the benefits of their suggestions. I am, &c. X.Y. MAGNETISM. Mr. Leopold Vacca has discovered a method of com- municating magnetism to a bar of iron without a magnet. He takes a bar of iron of about three feet in length, which gives no sign of possessing any magnetic virtue as long as it lies in a horizontal position : but it possesses this in a very sensible degree when placed perpendicularly. These signs disappear again when it is laid down horizon- tally, and appear again when it is lifted up vertically. A small bar of s:eel rubbed several times in the same direction, against the extremity of the other bar, when situated vertically, acquires magnetisan : whence the dis- coverer concludes, that magnetism may be communicated tV a body, without cither a natural or an artiiicial magnet. COBALT. %5S Cobalt, — Patents, COBALT. Those interested in the prosperity of our porcelain ma-» nufacturcs will rejoice to be informed that a mine of very excellent cobalt bus been discovered in this country. We have been int'ornied by Mr. Hume of Long-Acre, to whom a specimen has been submitted for examination, that on analvsis he has found it to contain nearly 30 per cent, of that metal. LIST OF PATENTS FOR NEW INVENTIONS. To Thomas Bayley, of Birmingham, for certain improve- ments in sliding pulleys for window blinds, and for other purposes. — Januar\' 15. To Peter Cox, of Fairford, in the county of Gloucester, civil engineer, for certain iniprovements upon the thrashing machine. — January 23. To Joseph Manton, of Davies-street, Berkeley-square, gun-maker, for an improvement in telesco})es. — Jan. 23. To David Cock, of Dean-Street, Soho, in the county of Middlesex, stert-otype manufacturer, for vessels of a new construction, for melting and heating fluids. —Feb. 1. To Augustus Frederick de Heine, of Moor Lane, Fore- Street, in the city of London, gent., for certain improve- ments on printing and stamping-presses. — Feb": 1. To John Craigie, of Quebec, in our province of Lower Canada, in North America, esq., now residing in Craven Street, in the county of Middlesex, who in consequence of communications made to him when residing abroad, and certain inventions by himself, is in possession of a me- thod of making an improved kitchen fire-place, — Feb. 1. To Stedman Adams, in the city of Hartford, in the state of Connecticut, in North America, esq., at present residing in Carey Street, Lincoln's Inn Fields, in the county of Middlesex, for certain improvements on steam-engines, and in distillation. — Feb. I. To William Muller, of the Hay Market, in the county oi Middlesex, for certain improvements in the construc- tion of pump.=. — Feb. ')9., To John Slater, of Birmingham, in the county of War- wick, coach-spring maker, for an improvement in hanging and securing grind stones from breaking in the middle or centre. — Feb. 12. To William Doughty, of Birmingham, in the county of Warwick, engineer, for his improvement in the combina- tion of wheels for gaining mechanical power. — Feb. 12. To George Wyke, esq., of the city of Bath, for certaia J ' ' improve-- List of Patents for New Inventions, 1 59 improvements in the construction of wheel carriages of va- rious descriptions. — Feb. 12. To Peter Warburton, of Corbriclge, in the county of Staflford, china inamifaciurer, for his new method of de- corating china, porcelain, earthenware, and glass, with native pure or aduhcrated gold, silver, platina, or other metals, or fluxed, or lawered with lead, or any other sub- stance ; which inventior. leaves the metals after bein^ burned in their metallic state. — Feb. 13. ^\) Richard Witty, of the town of Kingston-upon-Hull, gent., for certain improvements in making, arranging and combining certain parts oF rotative steam-engines, by which means the most complex parts of the steam-engines - now in use are dispensed with and rendered unnecessary, and the whole of the mechanism made much njore simple, less expensive, and not so liable to be out of repair, as that of the steam-engines now in use, and a|)plicable to giving motion to all sorts of mill-work or machinery. — Feb. 14. To Eneas Morrison of the town of Greenock in Scot- land, for a machine for conveying persons frOm the upper parts of houses on tire, and for lowering goods from ware- houses, and other purposes. — Feb. 22. To Peter Stuart, late of Fleet Street, in the city of Lon- don, printer, for his method of engraving and printin<»" maps of counties, charts, or other plans or designs, music, mathematical diagranisor figures on wood, metal, orany other substance, so that they may be thrown off in a common printing press or presses, either for books, newspapers, or any other printed paper vybaiever. — Feb. 26.' To William Bainbridge, of the parish of St. Andrew Holborn, in the city of London, nuisical instrument maker, for certain improvements on the English flute and flageolet. — Feb. 26. To Major Pratt, of Spencer Street, St. George's-in-ihe- East* in the county of Middlesex, tarnur, for certain me- thods of manufacturing njachines for perforniing various agricultural operations by. mechanical powers.-^Feb. 26. To Augustus de IJeine, of Burr Street, in the county of Middlesex, gent., for certain apparatus by the applica- tion of known principles to preserve animal food,vegetabie food, and other perishable articles, along time from perish- ing or becoming useless. — Feb. 26. To Charles le Caan, of the town oF Llanelly, in the county of Carmarthen, gent., for certain apparatus to be added and united to the axle-trees and u heels or naves of wheels of carriages, so as to impede, resist, or clieek their action. — Feb, 26. metkoro- 160 ^ Meteorology, METEOROLOGICAL TAIJLE, Br Mr. Carey, of the Strand, For February 1810. Thermometer. Height of the Baiom. Inches. DegreesofDry- ness by Leslie's Hygrometer. Days of the Month, c 1 j:2 Weather. Jan. 27 32 32^ 31« 30-21 0 Cloudv 28 29 31 30 33 33 30 30 •22 •28 7 6 Cloudy Cloudy 30 S3 33 30 •40 4 Cloudy 31 32 43 47 •25 0 Cloudy Feb. 1 47 47 46 •02 0 Rain « 46 47 44 29.90 0 Rain 3 45 47 46 •70 0 Rain 4 45 46 26 •92 10 Fair 5 33 45 44 30-00 10 Fair 6 46 47 44 29-96 7 Fair 7 8 47 46 47 47 46 45 •94 •90 4 0 Cloudy Rain 9 44 47 46 •70 0 Rain 10 47 50 44 •78 0 Rain 11 44 44 .40 •81 0 Rain 12 40 41 40 •42 0 Rain 13 38 42 38 28-95 6 Stormy 14 a6 39 36 29-50 5 Fogsv 13 35 37 30 •90 7 Cloudy 16 26 38 27 30-00 10 Fatr 17 27 35 26 •JO 9 Fair 18 27 33 36 •11 0 Snow 19 28 36 28 29-98 5 Fair 20 27 30 24 30^22 7 Fair 21 19 30 26 •40 10 Fai* 22 26 34 28 •08 5 Fair 23 35 45 40 29-40 0 Rain 24 40 49 47 •50 ' 0 Small ram 25 47 51 40 •46 35 Fair 26 37 K. B. The Barometer's height is taken atone o'clock. [ 161 ^"^ XXV. On Injuries of the Brain, To Mr. TillocL Sir, In the last Numi)er of your Magazine, there is a very interesting case recorded of considerable derangement of tlie structure of tlie brain, thoracic and abdominal viscera.* — The former it is my intention particularly to advert to. The person in whom this disease (tumours in the me- dullary substance of the brain) existed, is noticed to have been an acute reasoner, a man of good understanding : — in short, to use the author's own words, ** distinguished for the facility with which he could converse upon most sub* jects ; and reasoned so closely that his intellectual powers were generally regarded as of a superior kind.'' Lately I exaanned the brain of a person who died of in- sanity. It was a fesnalc between Co and 70 years of age, who, as far as I could learn, had been deranged for some considerable time (at least 10 years) ; but, as I had not an opportunity of seeing her whilst alive, cannot distinctly say of what species : — ouffice it to observe, it was of the raving kind. . Upon removuig the calvaria (or upper part of the cra- nium), and raising the dura mater. I discovered the tunica arachnoides to be very opake ; I could easily distinguish it upon the superior surface of the brain, which cannot be done with facility in the natural state, or where no disease is prfsent. The vessels of the pia mater were loaded with blood, but no effusion was apparent between the mem- ' branes. Upon separating the hemispheres to observe the corpus callosunii I found the arterial callosse considerably enlarged, and in that state which precedes ossification, and there was no appearance of raphe. 1 then proceeded to remove part of the left hemisphere, in order more readily to examine the ventricles; in doing which I nearly cut through the whole of a tumour, which 1 found to be situated partly in the cineritiou's and partly in the medullary substance of the brain, opposite to ihe temporal fossa. The tumour was about the size of a half-crown piece, and somewhat of that shape, though inclining to oval; it was of a granulated appearance, liighly vascular, and around the edge presented a dark blue colour; it was in structure precisely similar to those (for I had an opportunity of ex^ amining them in the recent state) described by Mr. Taun- ton ; — there was an artery entering at the outer sicle which was in a state of ossification. Vol. 33. No. 143. March 1810. L It 1 62 On Injur tes of th$ Brain, It is necessary to observe, that the substance of I he brairt was of a very soft consistence, whereas in the case related by Mr. T. it was of a pecuhar hardness. I do not imagine that this softness arose from the mental derangement; as it has occurred to my lot to examine the brain of many per- sons who have died insane, where this organ has been of Sts nsual texture, and sometimes unusually firm. ^^ Many other diseased appearances were observed during the dissection, but which are generally attendant in cases of mania; such as water in the ventricles, opacity of the septum lucidum, bloody points in the medullary substance of the brain, &c. besides opakencss of the tunica arachnoides, and turgescence of the vessels of the pia mater before men- tioned. The whole of the nerves arising from the brain were un- commonly firm, and the olfactory (as in the instance re- corded by Mr. T.) were in appearance similar to a piece of narrow tape, adhering strongly to the crihriform process of the ethmoidal bone^ and aflbrded some Httle resistance to the knife. Mr. T.'s case appears to establish the fact, of the brain, the most delicate organ in t4ie whole structure of man, be- ing capable of accommodating itself to an extraneous sub- stance without producing any visible alteration in the ope- rations of the mental faculties. The question which seems naturally to arise from this circumstance is : Whether the substance of the brain was not absorbed in proportion to the quantity of deposition secreted by the arteries? — andj Whether this could be effected sufficiently gradually, iiot to" impede the functions of that wonderful and anomalous organ*? placed (as Harwood elegantly expresses it) on the doubtful confines of the material and spiritual worlds ! That the brain may become absorbed in proportion to the growth of the tumours, appears to me highly probable ^ and that these tumours (in Mr. T.'s case at least, if not in mine) were in the first instance exudations of lymph, which in course of lime became organized. It is an interesting subject, and 1 hope will be considered by more able ana- tomists and physiologists than mvself. Wuh respect to the abdominal viscera : — That the pan- creas as well as many other of the organs contained in the abdomen may he diseased and not suspected, I have wit- nessed in several instances. I have in a number of case§ *.That the artefies perfofmed this secretion In a very slow manner must ^e obvious, as no symptoms of compression were present during life. after On Salmon- Leaps, 163 after death upon examination found that organ in a consi- derable btate oK disease, where the only symptom that ex- isted during life was a slight degree of dyspepsia/ I am yours, &cc. Reet Street, Feb. 10, 1810. T. J. PeTTIGREW. XXVI. On Salmon-Leaps. To Mr, Tilloclu Sir, W hoever carefully peruses Mr. Cam's paper " On the 'ascent of salmon over the elevations in the course of rivers called salmon-leaps," as given in your Magazine for November last, must needs Le astonished indeed at the ra- pidity of the growth of young salmon, from the period of their being spawned to their departure out of the rivers. As he is not precise as to the time when these occurrences happen, I must beg leav^c to state them : — The spawn is deposited chiefly in December and January, and the salmon depart in the beginning of April, being on an average a space of about fourteen weeks. Now admitting the eggs to be hatched in eight weeks (which I believe is much too hitlc), we have only six weeks for the young fry to arrive at the length oi six or eight inches ; an increase which is ab- solutely incredible, more especially v;hen we consider the comparative want of food incident to the season. The fact is; the young fry do not descend the rivers with. the old salmon, in the spring after they are spawned ; for in the month of October following they are no bigger than a minnow. Mr. John Clayton of Stockport (who is reckoned to be one of the most experienced anglers in the kingdom), and others, have frequently caught them of the size, and at the time stated, and are fully satisfied of their being young salmon. In the months of June and July they are caught about five or six inches in length : this I know to be fact ; and it is not till the ensuing spring that they pass with the old ones down the rivers with the floods into the sea. Their growth is there very rapid, as they are found on their return, in the months of August and Sep- tember, to weigh from 14 to SO ounces. This statement, if not established beyond all doubt by incontrovertible facts, is highly probable, and accords more with their progressive growth, and rational conjecture, than the account given lo us by Mr. Carr. I am, &c. feb.lO, I80i. PiSCATOR. L2 XXVII. Gn [ 164 ] XXVIT. On Platina and Native Palladium from Brasil, By William Hyde Wollaston, M,D, Sec,R.S* Although platina has now been known to mineralogists for more than 6o years, yet it had not been discovered in any other places than Choco and Santa Fe, whence it was originally brought, until' about t\X'o years since M. Vau- quelin discovered it in some gray silver ores from Guadal- canal in Estremadura. In analysing these ores, he found some fragments that contained as much as one-tenth of their weight of platina, but he did not find it accompanied by any of the new metals that have lately been discovered in the Peruvian ore of platina. The specimen which I am now about to describe is de-r rived from a third source, and it is rendered the more in- teresting by having grains of native palladium mixed with it. This new mineral has lately been received from the gold mines in Brasil, by H. E. Chev. de Souza Coutinho, ambassador from the court of Portugal, resident in this country ; and I am in hopes that some account of it may be acceptable to the Royal Society, although the analysis must necessarily be very imperfect, from the small quantity to which my experiments have unavoidably been confined. The general aspect of tJiis specimen is so different from the common ore of platina, that I could form no con- jecture of what ingredients it might be found to consist. Its appearance was such indeed, as at first sight to induce a suspicion of its not being in a natural state, for it had very much the spongy form which is given to platina from imperfect attempts to render it malleable by means of arsenic. One circumstance, however, occasions a presumption that no art has been employed in giving the grains their present appearance ; as upon close inspection many small particles of gold are discernible, but there is none of the magnetic iron sand with which the IV.ruvian ore abounds, nor any of the small hyacinths, which 1 have formerly no- ticed as accompanying that mineralf. It is very well known, that the connnon ore of platina in general consists of flattened grains, that appear so much worn at their surface, as to be in a considerable degree po- lished, and the roughness observable in some of the larger grains arises from concave indentations of a reddish brown ♦ From Philosophical Transactions for 1809, Part II. . I Fhil. Trans, for 1805, p. 318. or On Platina and Native Palladium from BrasiL 165 or black colour. The Brasilian platina, on the contrary, lias no polish, and does not appear worn j but most of the grains seem to be small fragments of a spongy substance, and even those which are yet entire aud rounded on all sides, present a sort of roughness totally different from that of the former, as their surface consists of small spherical protuberances closely coherent to each other, with the interstices extremely clean, and free from any degree of tarnish. The first portion that I employed for solution was taken without any selection, and being digested with a small quantity of nitro muriatic acid, two of the grains were acted on much more rapidly than is usual with platina, and seem- ed to give a redder colour than that metal alone. These grains were consequently taken out, washed, and reserved For separate examination, and the solution was allowed to proceed till the rest were entirely dissolved. By the addi- tion of muriate of ammonia an abundant precipitate was formed of a bright yellow colour. This precipitate was evidently platina, and its colour satisfied me that the grains had not been brought into their present state from Peruvian platina by means of arsenic; for where arsenic has been employed, I have observed that the iridium contained in that ore is rendered more soluble than before, and hence communicates its red colour to the precipitate. From the grains thus examined, there appeared not ta be any iridium dissolved, nor any black pbwder containing iridium undissolved. T next endeavoured, by prussiate of mercury, to ascertain the presence of palladium ; but though a precipitate which occurred indicated a certain quantity, it remained doubtful whether it was derived from the grains of platina them- selves, or from the two small fragments that had been in part dissolved before they were separated from the rest. By addition of ammonia to the solution, no iron was precipitated 5 and when the solution was afterwards al- lowed slowly to evaporate, 1 could discern no crystals or colour that f could ascribe to the presence of rhodium. In short, it seemed that these grains are really native platma nearly pure. In order to discover whether the grains themselves con- tained any portion of gold, I selected three of the largest, weighing together eight grains and a half; and after a so- lution and precipitation, as before, by muriate of ammonia, I added a solution of green sulphate of iron, and obtained a precipitate of gold. Il was, however, far too small in quan- L 3 tity I(x6 On Plainia and tity to be estimated with correctness, but certainly did not exceed the -y-^of a grain. This, it is to be observed, is another circumstance in which tlie present mineral differs from the Peruvian ore of platina, which I beheve never contains (in the ore itself) the smallest quantity of gold. In this experiment also, I tried to detect the existence of palladium in the solution, and by prussiate of mercury aj^ain .ascertained it^ presence; but it was in too small quantity for estimating the proportion it bore to the whole mass. It may deserve to be remarked, that though neither the Peruvian nor Brasilian grains of platina contain any silver, yet the gold which accompanies them is in each instance so much alloyed with silver, that from about thirty small scales of gold picked from Peruvian platina, weighing two c^raiiTS, I obtained as much as four tenths of a grain of silver, or one fifth part of their weight. Native Palladium, The two fra?"ments, that had been separated from the first solution, next claimed my attention, and evidently de- served a careful examination. They were each placed in a drop of nitric acid, aiul each communicated a deep red colour, which, by the tests of prussiate of mercury and ^reen sulphate of iron, I was satisfied arose from palladium. The smaller fragment was then divided, and one portion •allowed to remain in the acid till it seemed completely dis- solved, and the other examined by the blow-pipe. The utmost Iveatlhat could be given, appeared to have no effect : but when a small piece of sulphur w-as applied to it, it fused instantly; by continuance of the heat, it parted with the sulphur, and became completely malleable In short, it perfectly resembled palladiuni ; aiid as it retained its bril- liancy in cooling, I judged it to be nearly pure. But as the surfaces which had beeir acted upon by nitric acid had a degree of blackness, that might be owinc to some insoluble impurity, 1 have since that time dissolved the larger fragment for the sa'.ce of discovering the cause of this a[)pearance. Hot nitric acid dissolved by far the greatest part ; but there remained a black powder on which a fresh addition of this acid alone had no further effect. But when a drop or two of muriatic acid was added, the •whole was very soon dissolved. By i;he addition of muriate of ammonia, it became evident from the precipitate that .the residuum was principally platina. But this precipitate, instead or bemg yellow, had the Jeep red colour, which is usually occa«>ioned by the presence of iridiuna. The pla- tina Native Palladmnjrom Brasll, 1 6t tina reduced from this precipitate was, also too black, for pure platina, and when it was again dissolved, the solution •was of a deep red, and the precipitate by muriate of am- monia red, as before; so that although the grains bf Bra- silian platina appear to be free from iridium, aS well a5 from many other impurities that form part of the Peruvian ore, yet the grains of native palladium that accompany them, alTord a trace of this ingredient, and occasion a presumption that osmium and rhodium may hereafter appear, when we can obtain this mineral in larger quan- tity. Since the whole weight of metal employed in the last experiment did not exceed lyV grain, it is in vain to at- tempt to estimate the proportion of the ingredients ; but if I am near the truth, in considering the quantity of the red precipitate as about one fifth of a grain, of which less than ialf is platina, those who are best acquainted with the in- tense colouring power of iridium may endeavour to form i conception oi the extremely small quantity that can be present. , . \ ^ ' * - ..;.,,. As soon as I had ^ascertaiived lhe,eikistehGe.o)F native ^^^^^^^ Jadium, I endeavoured, by examinatiou of its external cha- racters, to distinguish its appearance from that of the sur- rounding substances, and I found it by no means difficulty although no difference of colour could be discerned. Hav- ing remarked that the larger fragment appeared rather fibrous, and that the fibres were in some degree divergent from one extremity, I examined the remainder of the small upecimen which had originally been given to me, and by this peculiarity of structure I soon detected a third frag- ment, which upon trial proved to be the. same substance. By favour of the Chev. de Souza I was also ])ermltted5 with this view, io examine the specimen which remained in his possession, and had soon the satisfaction of discovering two more fragments of the same mineral ; and as I was in no one instance deceived in my choice, by attending to the radiating fibres, I am in hopes that this external character will enable persons to distinguish that metal, in situations where they have not an opportunity of deciding by chemical experiment* hi XKVIII. On t 168 ] JCXVIIT. On an hnprovement hi the Manner of divulrng astronomical Instrmnents* By Henrv CAViiNDisH, Esq.^FJlS.* J- HE great inconvenience and difficulty in the common method oF dividing, arises from the danger of bruising the divisions by putting the point of the compass into them, land from the difficulty of placing that point mid-way, be- tween two scratches very near together, without its slipping towards one of them ; and it is this imperfection in the common process, which appears to have deterred Mr^ Troughton from using it, and thereby gave rise to the in- genious method of dividing described in the preceding part of this voUnnef 1 Thi* induced me to consider, whether the above-mentioned inconvenience might not be removed, ^y using a beam compass with only one point, and a mi- croscope instead of the other ; and I find, that in the fol- lowing manner of proceeding, we have no need of ever setting the point of the compass into a division, and con- sequently that the great objection to the old method of di- viding is entirely removed. In this method, it is necessary to have a convenient sup- port for the beam compass : and the following seems to me to be as convenient as any. Let C C C (Plate V. Fig. 1.) be the circle to be divided, B B B a frame resting steadily on its face, and made to slide round on it with an adjusting mo- tion to bring it to any required point ; d^ is the beam com- pass, having a point near ^, and a microscope m made to slide from one end to the other. This beam compass is supported at d, in such manner as to turn round on this point as a centre, without shake or tottering , and at the end $ it rests on another support, which can readily be lowered, so as either to let the point rest on the circle, or to prevent its touching it. ft must be observed, however, that as the distance of of from the centre of the circle must be varied, according to the magnitude of the arch to be divided, the piece on which d is supported had best be made to slide nearer to, or further from, the centre; but the frame nmst be made to bear constantly against the edge of the circle to be divided, so that the distance of d from the centre of this circle, shall not alter by sliding the frame. This being premised, we will first consider the manner of dividing by continued bisection. Let Fandy be two • From Phllosopliical Transactions for 1 809, Part II. I jSee Phil. Mag. vol, >xxiv. pages 8 ( and 163. points Improvement in dividing astronomical Instruments, 169 points on this limb which are to be bisected in and having lowered the support at $, make a faint scratch with the point. Having done this, turn the beam compass round on the centre d till the point comes to D, where it must rest on a support similar to that at $ ; and having slid the frame till the wire of the microscope bisects the point f, make an- other faint scratch with the point, which, if the distance of the microscope from the point has been well taken, will be very near the former scratch ; and the point mid-way be- tween them will be the accurate bisection of the arch Ff; but it is unnecessary, and better not to attempt to place a point between these two scratches. Having by these means determined the bisection at (p, we must bisect the arches F

tance from the centre of ination d, as ihe point; but removed from it sideways, by nearly the semi-dinmeter of the object glass ; so that hav- ing made the division, wc may move the beam compass tiJI tlK- division conties within the fiield of the microscope, and |Iie,p sec whether it is bisected by the wire, and consequently pee whethertlie microscope has altered its place. In the operaiic^n of bisection, as above described, it may •be observed, that if the two scratches are placed so near to- gether, that in making the second the point of the compasa runs into the burr raised by the first, there seems to be some danger that the point may be a little deflected from its true course; though in Bird's account of his method^ 1 do not find that he apprehends any inconvenience from it. One way of obviating this inconvenience, if it does exist, would be to set the beam conipass not so e ,o^craich j', then bring the microscope to f, and drAw th^ ^cratch € ; and in the same manner make the scratches d an<3 ^. 'I'hen turn the beam compass halF round, and hav- in«g brougVfi the microscope to a, make the scratch ^ ; and proceeding as beFore, make the scratches ^, s and nd will be distant Frojn o by two fii'ihs of rf 5, and so on. • Then, iii subdividing these arches, and striking the true divisions. Manner ofdlvid'mg astronomical Instruments, 171 tJlvisions. the wirc^ of the microscope, instead of bisecting the interval between the two scratches, must be brought four times nearer to j8 than to h. But in order to avoid the contusion which would otherwise proceed from this, it will be necessary to place ujarks on the limb opposite to all those divi^i()ns, in which the interval of the scratches i» nut to be bisected, shown}g in what proportion they are to be divided; and these marks should be placed so as to be vi- sible through the microscope, at the same time as the scratches. Perhaps, the best way of forming these marks, would be to make dots with the point of the beam com- pass contiguous to that scratch which the wire is to be nearest to, which may be done at the time the scratch is drawn. Perhaps an experienced eye might be able to place the wire in the proper manner, between the two scratches,^ without further assistance; but the most accurate way would be to have a moveable wire with a micrometer, in the focus of the microscope, as well as a fixed one; and then having brought the fixed wire to h, bring the move- able one to /3, and observe the distance of the two wires by the micrometer; then reduce the distance of the two wires to one fifth part of this, and move the frame till the moveable wire comes to j6, and then the fixed wire will be in the proper position, that is four times nearer to ^ than lo h. It will be a great convenience, that the moveable wire 'should be made in sucti manner, as to be readily distin- guisned from the fixed, without the trouble of moving it. In this manner of proceeding, 1 think a careful operatOFf can hardly make any mistake : for if he makes any con- siderable error in the distance of the moveable wire from the fixed, it will be detected by the fixed wire not appearing in the right position, in respect of the two scratches; and as the mark is seen through tlie microscope, at the same time as the scratches, there is no danger of his mistaking which scratch it is to be nearest to, or at what distance it is to be placed from it. To judge of the comparative accuracy of this method with that of bisection, it must he considered that the arches «|S, /3 ^, &c. though made with the same opening of the Compass, will noi be exactly alike, owing partly to irregulari- ties in the brass, and partly to other causes. Let us suppose, therefore, that in dividing the arch a a, into five parts, the beam compass is opened lo the exact length, but that from the abovementioned irregularities the arches, a /3, /S (^, ^s, and 172 On ^n Improvement in tlie and s p are all too long by the small qtjantity s, and thsi the arches nf, fe., e d, and d b are all too short hy the same quantity, which is the supposition the mostuntavour- able of any lo the exactness of the operation; (hen the ^rror in the position oF ,6 =± g, and the point /» errs 4s in the game direction, and therefore the point assumed as the true point ot quinquesection, 'will' be JTt th^ distance of -4- from /3, and the error in the position of this point = s x If. By the saine way of reasoning, the error in the position of the point taken between d and ^ = g x 2^-. In trisecting the error of each point = e X 1-^j and in bisecting, the error = s; and in quadrisecting, the error of Vhe middle point = 2 s. It appears therefore that in trisecting, the greatest error we are liable to does not exceed that of bisection in a greater proportion than that of 4 to 3 ; but in quinquesecting the error of the two middle points is 2f times greater than m bisecting. It must be considered, however, that in the method of continued bisection, the two opposite points must be found by quadrisection ; and the error of quinque- section exceeds that of quadrisection in no greater propor- tion than that of six to five; so that we may fairly say, that if we begin with quinquesection, this method of di- viding is not greatly inferior, in point of accuracy, to that by continued bisection. Second Method, This differs from the foregoing, i n placing dots or scratches in the true points of quinquesection and trisection, before we begin to subdivide. For this purpose, we must have a niicroscoi|ie placed as in page 170, first par. at the same di- stance frfMT) the centre of motion as the point is ; and this microscope must be furnished with a moveable wire and micrometer, as in page 171 ; ^nd then having first made the fixed wire of this microscope correspond exactly with the point, we must draw the scratcht^s b and /3, d and ^, &c. as before, and bring the fixed wire lo the true, point of quinquesection between b and /3, in the manner directed in page 226, and with the point strike the scratch or dot : and if we please, we may, for further security, as soon as this is done, examine, by means of the moveable wire, whether this intermediate scratch or dot is well placed. The advantage of this method is, that when this is done, we may subdivide and cut the true divisions, by making the wire of the microscope bisect the intermediate scratches, instead of being obliged to^ use the more troublesome ope- ration Manner of dividing astronomical Instruments, \ 73 ration of placing it in the proper proportion of distance between the two extremes. This method certainly requires less attention than the former, and on the whole seems to be -attended with con- siderably less trouble ; but it is not quite so exact, as we are liable to the double ^iror of placing the intermediate point and of subdividing from it. As in this method tlie iniermediate points are placed by means of the micrometer, there is no inconvenience in placing the extreme scratches b autl jS, &c. ^lt such a di- stance from each other, that the intermediate one shall bfe in no danger of running into th^ burr raised by the ex- tremes. Third Method, Let a a (Fig. 3.) be the arch to be quinquesected ; \vf down the arches uh, d b^ and de, as in the first method; then turn the beam compass half round, and lay down the arches a jS and /3 ^ ; then, without altering the trame, move the moveable wire of the microscope till it is four tunes nearer to iJ than to i?, and, havinfi^ first rubbed out the for- mer scratches, lay Ihem down again with the com^H^si*. thus altered: but as this meihod possesses not much, if any, advantage over the second, in point of ease, and is certainly inferior to it in exactness, it is not worth while saying any thing further about it. It was before said*, that the centre of motion of the beam compass is to be placed, so that the point and axis of the microscope shall both be in the circle in which the di- visions are made ; but it is necessary to consider this more ac- curately. Let A^ (Fig, 4.) be the circle in which the scratches are to be made, ^ the point of the beam compass, which we will suppose to he exactlv in this circle, d the centre on which it turns, and Mm the wire in the focus of the mi- croscope, and kt m be that point in which it is cut bv the circle; and let us suppose that this point is not exactlv in the line o?^, then, when the beam compass is turned round, the circle will cut the wire in a different point ja, placed as nuich on one side of t/ J, as m is on the other, so that if the wire is not per[)endicular to d^, the arch set off by the beam compass, alter beini: turned round, will not be the same as before; but if it is perpendicular, there will be no differenct ; for which reason, care should be taken to make the wire exactly perpendicular to c?^, which is easily ex- anjined by observing whether a point appears to run alon^*- • Page 168. i(. 174 Improvement in dividing astronomical Instruments. it, while the beam compass is turned a little on its centre. It is also necessary to lake care thai the point $ is in the arc of the circle, while the bisection is observed by the microscope, which may most conveniently be obtained, by placing a stop on the support on which that end of the beam compass rests. If proper care, however, is taken iiv placing the wire perpendicular, no great nicety is required either in this or in the position of d. Another thing to be attended to, in making the wire bisect two scratches, is to take care that it bisects them in the part where they cut the circU- ; for as the wire is not perpendicular to the circle, except in very small arches, it is plain, that if it bisects the scratches ai the circle, it will not bisect them at a diatance from it. There are many particulars in which my description of the apparatus to be employed will appear incomplete; but as there is nothing in \e which seems attended with dif- ficulty, I thought it best not to enter further into particu- lars, than was necessary to explain the principle, and to leave the rest to any artist who may choose to try it. It is difficult to form a proper judgement of the con- veniences or inconveniences of this method, without ex- perience; but, as far as I can judge, it must have njuch advantage, both in point of accuracy and ease, over that of dividing by the common beam compasses : but it very likely may be thought that Mr. Troughton's method i? better than either. Whether it is or is not, must be left for. determination to experience imd the judgement of artists. Thus much, however, may be observed, that this, as well as his, is free from the difficulty and inaccuracy of setting the point of a compass exactly in the centre of a division. It also requires much less apparatus than his, and is free from any danger of error, from the slipping or irregularity in the motion of a roller; in which respect his method, notwithstanding the precautions used by him, is perhaps not entirely free from objection ; and, what with some artists mav be thought a considerable advantage, x it is free JTom the danger of mistakes in computing a table of errors, and in adjusting a sector according to the numbers of that table. XXIX. Oh C J75 ] XXIX. O?! M. Bemetzrteder's erroneous Calculaihm of the Matmkudks of certain musical Mtervals, By Mr, John Farkv. To Mr. Tilloch. 55"iR, VV HEN r some time ago took up my pen*, to combat the erroneous principles advanced by Earl Stanhope, re- specting: the accuracy of expressing musical intervals \^y the difference oF tht lengths of strings producing the sounds, I thought that his lordship had an exclusive claim to this, and other similar and '^ important musical truths,** which" he has advanced ; but a folio work opening the long- way- was this day put into my hand)?, entitled, '* General In- structions in Music/' by M. Bemetzrieder, printed at Lon- don, about the year 1780 (as I have been told j, price one guinea. Who ailer statmg, at page 92, that a major tone u ~ 3 3 9 27 — taken from a minor fourth ~, ov '— x -^ produces — (which he calls a minor third) and which taken from a fifth 2 3~ -, or — X — produces — (which he calls a major third), tmd mentioning, that -^ and -.- are ratios usually as^xgntdi to the 3**. and III'^., thereon subjoins these remarks : ^' It i$ '^ probable, that \.\\q facilhy of arithmetical calculation has ^^ been preferred to geometrical exactitude ; besides, the 4 64 " difference of the two (major) thirds -- and — - is no more *^ than — ^ (being the difference o^ ^^ and ^-_) the 90th *^ part of a tone (because — ^— - = ^ = --7 which is let- *^ ter perceived by the understanding than by the ear ; the *^ (major) third - is a 90Th part of a tone lower than the ^^ third --> The difference of the two minor thirds — ol 6 " and -~ is -—; the (minor) third—, is —too acute;*' 32 96 ' ^ ' 6 96 for as above, -[^ - -^ = -L = -L, and still proceeding as >Above, ~— = — 5 or, — is more than — by an 83} part of the same tone (~) as above. Now, if instead of taking jhe numerical differences of the thirds, in Mr. B.'s erroneous * See our 27th Volume, pr;r mentioning it here, that, though the water in .which bean straw has been put to steep, in a fe\V days generally acquires a black colour, a blue scum and a peculiar taste, yetcatile drink it greedilv, and seemed fattened by it. But my experiments have hitherto been on too hmited a scale to be able, in a satisfactory manner, to ascertain this last circumstance. When the water in which bean straw has been put to steep, becomes foetid, which I find it lif^^carcely more a])t to become than common stag- nant water, on bc-:ng stirred by driving horses or cattle through it, by a stick, or in any other way set in motion, (as is the case v^ith all putrid water, even the ocean itself,) the fcetid particles fly oif, and the effluvia dies away." ''-When straw is to be steeped for bean hemp, the bean^ are a Fibrous Sttbstancs from Bean Stalks, 183 are to be thrashed in a mill : the bcarrs should be put to the rnill, not at right angles^ but on a parallel., or nearly so, with the rollers, eli?e the stravt', particularly it" the beaiis are very dry, is apt to be much cut. If the straw \s not to be steeped, on putting the beans to be thrashed at right angles, or nearly so, with the rollers of the mill, a certain proportion of the fibres, or hemp, may easily be got from the , straw, these being in general not so much cut as the straw ; but often f/uid torn off and hanging about it like fine sew- ing threads. The hemp thus taken off, though its lying under waier for months would do it no harm, requires only to be steeped a few minutes, drawn through a hackle and washed, previous to its being laid up for use. If ihc hemp, or fibres, collected in this way (which is a fine light busi- ness for children, and such as are not able for hard work, and which requires no ingenuity), are intended only for making paper, they require -neither steeping nor hacklings, but only to be put up into parcels and kept dry till sent off to the manufacturer. The straw of beans contains a saccharine juice, and is highly nutritive, perhaps more so than any other; and, like clover, the prunings of the vine, the loppings of the fig- tree, &c. produces a rich infusion, and commonly fine table-beer, as well as an excellent spirit by distillation. It is the hemp or fibres that prevents cattle from eating it. These, like hairs in human food, make cattle dislike it. The collecting of it, therefore, should never be neglected, nor the boys and girls in workhouses and other places be permitted to be idle, while business of this kind would evi- dently tend both to their own and their employers' ad- vantage. It is a fact, that about the generality of mills for beating and dressing hemp and flax, a large proportion, in some in- land places both of Great Britain and Ireland, ajiiounting nearly to one-half of what is carried thither, is either left there to rot, under the name of refuse, or thrown away as of no use, because too rough and sho^t for being spun and converted into cloth. Now, from the experiments I have tried, and caused to be tried, I have uniformly found, that though too rough and short for being convened into cloth, even of the co^irsesi kind, the refuse of hemp and flax, on being beat and shaken, so as to separate the strawy from the stringy particles, which can be done in a few minutes by a mill or hand labour, as is most convenient, becomes thereby a« soft and pliable, and as useful for making paper, as the longest, ancl what is reckoned the most valuable part of the M 4 plant. 1 84 On the Preparation of plant, after it has been converted into cloth and worn for year$. In its natural state, it is true the refuse of hemp and flax is generally of a brown and somewhat dark colour. But what of that ? Bv the application of muriatic acid, oil of vitriol, or other cheap ingredient, well known to ihe che- mist, as well as to every bleacher, such refuse, without being i?i the least injured for making paper, can, in a few hours, if necessary, be made as white as the fiiv;st cambric. There are, at a medium, published in London, every morning, 16,000 newspapers, and every evening about 14,000. Of those published every other day there are about J 0,000. The Sunday newspapers amount to about 25,000, and there are nearly 20,000 other weekly papers, making in all the enormous sum of 245,000 per week. At a me- dium 20 newspapers are equal to one pound — hence the whole amount to about 3 tons per week, or 260 tons per annum. But though this, perhaps, is not one-half of the paper expended in London on periodical pubHcations, and what may be called fugacious literature, and not one-fourth part of what is otherwise consumed in printing-houses in the country at large, yet there are materials enough in the refuse of the hemp and flax raised in Britain and Ireland for all this and much more. Nor is this all : for as the bine or straw of hops, a cir- cumstance well known to the Society, contains an excellent hemp for making many articles, so also will it prove a most excellent material for making all kinds of paper. i\nd,it is a fact, that were even the one-half of the bine of hops raised in the counties of Kent Sussex, and Worcester, instead of being thrown away, or burnt, after the hops are picked, as; is commonlv done, steeped for ten or twelve davs in water, and beat in the same way as is done with hemp and flax, in- dependent of what might be got from bean- hemp, and a variety of articles well-known to the Society, there would be found annually materials enough for three times the quan- tity of paper used in the British dominions. I have the honour to be, with much respect. Sir, Your most humble servant, James Hall. Strcatham, Jan. 9, 1809. To C. TAYLORi M. D. Sec. -^- Certificates a Fibrous Subs iance from Bean Stalkss 185 Certificates of the Truth oftheforegohig Statement. Streatham, Surry, Jan. 9, 1809. Wk, the undersigned, do liereby certify, that the speci- ments of hemp inclosed and sealed np by us, addressed to Dr. Taylor, secretary to the Soeiety for the Encourage- ment of Arts, Manufactures, and Commerce, Adelphi, Strand, are the produce of conmion bean straw : — That \vc never saw nor Jieard of bean hemp till lately ; when the Rev. James Hall, wlio resides here at present, was trying experiments respecting it at Mr. Adams's farm, Mount Nod, and other. pans of this parish : — That, in the present ob- structed state of commerce with the continent, it appears to us the discovery of bean hemp may be extremely useful to the manufacture of canvass, ropes, paper, &c. ;--and that, as it affords a new and important prospect of employment for the poor, we think Mr. Hall, the discoverer, is deserv- ing of the approbation of the public. We shall only add, that as the Society for the Encouragement of Arts, Ma- nufactures, and Commerce, have contributed so often in a high degree to the exertion of genius, the improvement of the arts, and the public good, we have no doubt but they will not only take the proper steps to prosecute the discovery and encourage the manufacture of bean hemp, but also, by some mark of their favour, show their approbation of Mr. HalTs merit in the discovery he has made, as well as of his high public spirit and liberality in communicating the dis- coveryM:o the public without reserve. William Adams, Mount Nod. Edward Bullock, Curate. Wm. Gardner, Surgeon. Streatham, Surry, Jan. 9, 1S09. These are to certify to the Secretary of the Society for the Encouragement of Arts, &:c. London, and all whom it may concern, that having seen (at first to our astonishment) the Rev. James Hall, who has resided here for some time past, procuring hemp from common bean straw, steeped some days in water, we steeped some also, and easily got hemp from it ; there being no mystery in the matter more than merely steeping the straw, peeling off the hemp, and then washing and cleaning it, by pulling it through a hackle or comb. These are also to certify, that having tried bean hemp, and 186 Preparation of a Fibrous Substance from BeanStalksl and found it to take both wax and rosin, we have sewed with it, and find the fibres of which it consists in general so strong, that the leather never failed to give way sooner than the seam. We have only to add, that as hemp has of late become uncommonly dear, while much of it is bad, we anxiously wish the prosecution of the discovery, and the appearance of bean hemp in the market ; and shall, so soon as we hear of its being spun and on sale, be among the first to purchase and use it. JohnHoune, Shoemaker. Thomas Altord^ Shoemaker. Letter from Mr, Htime, of Long Acre, to the Rev, James HalL Sir, I INCLOSE a specimen of the bean filaments or thread which have been submitted to the bleaching process. The texture and strength seem not in the least to have been im- paired, but retain ihe primitive tenacity ; and I am persuaded this substance will prove an excellent substitute for hemp and flax, for the manufacture of various kinds of paper, cordage, and other materials. I did not find more difficulty in accomplishing the bleaching of this than in other vege- tables which 1 have occasionally tried, and I believe this article is susceptible of a still greater degree of whiteness. I remain, sir. Your very obedient servant, Jos. Hume. Long Acre, Feb. 24, 1807. Letter from Mr, H. Davy to the Rev, James HalL Sir, I SHALL inclose in this paper a small quantity of the bean fibres, rendered as white as possible by chemical means. It seems to bear bleaching very well ; and, as to chemical properties, diflfers very litile from hemp. The question, Whether it is likely to be of useful applica- tion, is a mechanical one, and must be solved by experiments on its comparative strength. lam, sir. Your obedient humble servant, H. Dayv. XXXIII. On [ m I XXXIII. OnCrystaUographTj. By M.Ua\5Y. Translated from the last Paris Edition of his Traite cle Mineralogies [Continued from p. 153.J OF MINERALOGICAL METHODS. xjLll the productions of nature, considered in the point of view in which she presents them (Hrecily to our eyc», form a picture complicated with a multitude of details, in the midst of which the eye is lost at the first glance, and sees everv thing at once without distinguishing any thing. With the view of facilitating the study of this picture, there have been contrived, with respect to mineralogy, as with zoology and botany, methodical distributions of the subjects which are therein embraced ; their different pans have been dissected in imagination, so as to form a kind of factitious table, with which we may afterwards compare the former, and which serves it as a kind of explanation. However slightly we reflect on the progress of these methodical arrangements, we may easily perceive that thev are founded on the faculty possessed by the human mind of regarding certain qualitic? m an object, by abstracting others; and of raising ourselves gradually from particular to general ideas. Thus, when speaking of an oak as a determinate object which I can point out with my finger, I make no abstrac- tion ; I consider in the object which I name, all the qualities that can accord with it : in a word, I designate an indivi- dual, i. e.j a being which has a particular existence. But if, in pronouncing the word oak, I have not seen any par- ticular oak, then 1 abstract the idea of a particular ex- istence ; I designate in general a collection of individuals similar in all their parts, and this collection is what is called a SPECIES. The tiense in which I have taken the word Oak (or Quercus) is that which every body attaches to it in ordinary language. Now, on comparing the individuals of the species in question with those of another species, to which the name of Holm Oak {Iltx) has been given, I remark that the latter have the organs of the flower similarly con- structed, and that their fruits are acorns also ; but that they ditfer from each other in several respects, and particularly in the form and consistence of the leaves ; which in the former are broad, soft, and tern)inated by round lobes, and in the latter narrow and indented at the edges. I can, tliercfore, fix n\y attention solely im the resemblance of the flower 1 88 0« Cnjstdllograpfnj, flower and the fruit in the individuals of the two species, keeping separate in my iniaginalion all the parts which tlifler; and in order to adapt the nomenclature to this resemblance, which alone occupies my mind, I shall extend the name of oak to both the sj)e.cies. Reierring my mind afterwards to the differences which I have left on one side, 1 shall keep an acconnl of them in language, distinguish- ing by ibe name of common oak the individuals of the first species, and by the name of green oak those oF the second. I shall then have a genus, of which the common oak and the green oak will he two species. By a new abstraction I can consider in the two oaks no- thing but their size, ligneous consistence, and the faculty which they have of existing a certain nnmber of years ; and observing that several kinds of productions, different from oaks, hare also a great consistency and are very long lived, while a multitude of other species are of lower stature, more pliant, and exist a year or two only, I shall unite, un- der one and the same idea, the first by the name of trees y and I shall designate in common all the others by the name of skrubs. I shall thus have two great classes*, each of which may be subdivided into a certain number of genera, which will be groups of species. Finally, if I have no longer any regard but to the faculty which all these ob- jects have of vegetating, and of being nourished from the juices of the earth, 1 shall include them under the general denomination plant, and I shall thus attain, by a scries of ideas alwavs more abstract, the most elevated point of view of the vegetable kingdom. Human languages present a host of examj)les of similar abstractions, which a natural spirit of analysis has suggested even to the vulgar; and it is by directing their views in the same manner that the learned have formed their systems and methods. They have merely subjected these luethodical arrangements to more precise and more rational principles; tliey have multiplied their divisions and subdivisions, and have in some measure arranged them by the indication of the characters peculiar to the objects which each division contains. We see from what precedes, that in proportion as we ascend into the course of .abstractions, we connect together a greater number of beings, according to the relation or character analogous to the degree of abstraction. Thus the * I do not pretend to establish rigorous limits here between the divisions of bodies, hut merely to give a sketch of the progress of ideas by examples taken from fanxiliar objecis. idea On CrysiaUography* Itg idea which the worcl tree expresses, embraces incomparably more plants than that which is attached to the word oak^ . and the latter has a greater latitude than the idea presented to the mind by the word green oak. Reciprocally, every abstraction from an inferior degree compresses into a smaller space the number of the objects to which it is ex- tended. What does methodizing effect then ? — It divides and subdivides sncccssively the assemblage of objects, ac- cordincr to their various characters or relations, so that, at every division, all the characters enunciated in the preced- ing divisions being regarded as still subsisting, the method adds the expression of a new character, a new trait of re- semblance, which detaches the objects contained in this division. The more the sum of the relations increases, and the more on the contrary the number of objects with which these relations agree are diminished, and when this sum is the greatest possible, when it is extended to all the faces of the objects which it includes, each of ihese objects is considered as representing all the others, and we say that all these objects are of the same species. On the other hand, in proportion as the degree of abs- traction is raised, the number of subdivisions which an- swers to this degree diminishes : and it was this manner of regarding methodical order that the illustrious Bacon had in view, when he compared Nature to a pyramid the base of which was occupied by an almost infinite number of individuals : above this base rise the species formed by the assemblage of individuals, and which are consequently ex- tended over a narrower space than the base ; afterwards come successively the genera composed of species, then other superior genera (which answers to our orders and classes); until Nature, after having become narrower and narrower, terminates in a point, or in unity*. .We may also be able to see that the character which served to connect with each other the productions of one and the same division, distinguished them from those of another division. Hence, and from all that precedes, re- sult two remarkable advantages of the method. The first is, to make us acquainted with objects not only by them- selves but also by comparison, each of them being placed by the method in such a manner that it turns in some measure towards the rest the side in which it resembles them, and presents in an opposite direction that by which it is distin- • Bacon, De Avement. Scient. t. ii.c. 13. See the work which has for iu title " Le Ciiristianisme dc Fran9ois Bacon." Paris, an 7, t. i. j). i. guished 1 90 JQn O'ptallographij, giiisheil from ihcm. The second advantage is, that JiFter >\'e have been exorcised in making applications from the iD&thocl to a certain number of objects already known, we may attain a knowledge even of that which would be new to lis, by consulting succes>ively the characters which ac» company each division, and by making nse of the method to inqviire into the subject, and to learn from the object it- self the place which it occupies in the method. The series of divisions and sul)clivisions in n)ineralogicaf distributions is nearly the same as in those which reeard organic bodies. This .Series, taken by descending from generals to part icularsj gives ihc following gradation: classes, orders, genera,- 'species, .varieties. But there is a sensible difl'erenee relative to ihe methods used in these two departments of science, relative to the manner in which we consider objects, or to the choice of the method^'Cim- ployed to classify and characterize these objects. ' Thus, in botany, we cwW species the succession of plants which, reproduce each other. In ntinefalogy, there Ts nei- ther reproduction nor species, if xv£ take this i^xiw in «i rigorous acceptation. There is nothing, however, to hinder us fron) follou ing the example of Linnaeus, Bervj^man, and several other celebrated naturalistSj in applying the word species in a wider sense, to an .assemblage of inorganic beings which have a common basis, and ihe differences of which ought to be regarded as purely accidental. But this leads us to an important question, to which it does not seen) that sufficient attention has hitherto been paid. In what consists in the present case the type of the species; — and when are we justified in regarding several mi- nerals as belonging to one and the sanie species* ? It seems at first view as if chemical coiDposilion was the basis of this union ; so that the true notion of the species con- sists in conceiving an assemblage of minerals formed of the san)e principles united to each other according to the same laws. But we shall see how much this idea is sus- ceptible of restriction, and to what point even we should wander from our object, in a multitude of circumstances, on taking it for our guide, in assembling of varieties which ought to bear one and the same specitic name. * I shall by and by recur to the rhate'l banjtcs, Sec. It is sulVicicnt for my purpose at present to point out such of the divisions and subdivisions of l-he uitthod to -which 1 give the denociiuation sy.cdes. In ' On Cry st allograph^', tpt In order that T-may be better understood, I sball take aa example from lildspar. Mi*. Kirvvan, to whom we are in- debted for a treatise on mineralogy, in which that cele- brated author lias brought together, in the development of the science, the external characters of minerals and the results of his own researches as well as of those of othci^ chtmiists, as to the composhion of these bodies, cites 13 analyses of the substance in question, to which we may add a 14lh made by Vauquelin. No\V^ not only do the products vary among each other in the proportions of the same principle?, but there are ingredients which are found in certain products, and not in others. Thud Mr. Kirwan has procured from a reddish feldspar eleven per cent, of barytes and eight of magnesia ; whilst the re- sult obtained by Wieglicb in another feldspar of a red co- lour, furnished neither of these earths, but only silex and alumine, with a small quantity of oxide of iron and fluoric acid. Vauquelin found about one seveiMh of potash in the feldspar called adular^ and in the green feldspar of Siberia, and yet no other analysis has presented this alkali. Besides, this expert chemist has discovered neither magnesia nor barytes in the same mineral. Mr. Kirwan concludes, from the diflferent analyses quoted by him, that every compound of silex and alumine (the silex being predominant) to which is added a slight pro- portion of lime and magnesia, or of lime, of magnesia and barytes, (but sufficient to render tlie whole fusible at a de- gree of heat not exceeding 140'',) would form a feldspar ;'and we ought not to hesitate m giving it this name, if at the same time it presents a lamellous texture. But he adds that iron seems in this case to be an accidental principle. I do not observe that this rule laid down by Mr. Kirwan leaves any thing to be desired, so far as simplicity and pre- cision are concerned; but in spite of the efforts of the author to render it general, at the hazard of loading it with conditions, it is no longer applicable to the result of the analysis made by M. Vauquelin of the feldspar known by the name of adulary ; and finally, if we should undertake to give similar rules for all minerals, the result would be a complication from which it would be difficult to extricate ourselves, and it would even very probably, happen, that a rule which should have for its object such a particular species might be applied nearly equally well to an entirely different species. I shall not examine if all the analyses alluded to by Mr. Kifwan deserve an equal confidence. But we may at least conclude 193 On Cnjstallograpliy, conclude that they indicate perceptihlc dlfTerences of com- position between the specimens analysed. I could produce other examples of a mineral, the different analyses of which made by skilful operators have given difierent products ; and we shall presently sec that this must necessarily take place in a variety of circumstances. Now I return, and I ask, on what foundation Mr.Kirwan gives the name oF feldspar to the various specimens which have been the subjects of the analyses above mentioned. This intimacy surely \% not founded on the results of these analyses; since we should rather be inclined to infer, from the differences which they have presented, that a \'q\y at least of the substances to which they are referred, con- stitute distinct species, Iti a word, it is visible that Mr. Kirwan has tacitly supposed that, abstracting all considera- tion of the analyses, the substances in question had been regarded as feldsj->ars. On perusing what has been written by naturalists on the subject of this mineral, we see that its place was assigned according to a certain assemblage of characters, such as a hardness capable of producing sparks with steel ; a leafy texture added to its breaking into rhomboidal fragments : a specific gravity of about 2*5 ; a fusibility into a white enamel ; &c. But these characters arc for the most part variable to a certain point; and this variation may even be extended far enough, in certain cases, by a consequence of that which the component substances undergo. These are so many useful ways of assisting us to recognize bodies which be- long to one and the same species ; but in addition to their not presenting to the mind a sufficiently simple and precise idea of what constitutes this species, their results are not always proper for tracing the limit which separates one species from another: and it is on account of our being re- stricted to consulting them only, that we have confounded the pyroxene with the amphibolus, the chabasie with the mesotvpe, and so on with several other relative con- nexions, the fault of which will become evident from what wc shall ^ay under the respective heads of the substances to which tht-y are referred. There exists a character much more solid and much more proper by its invariability, to serve as a rallying point to the different bodies, which belong to one and the same species. This is derived from the exact form of the inte- grant molecule, because this form subsists, without any sensible alteration, independently of all the causes which may 0/1 Crysiallography, JD3 tnay cause the other characters tO; vary* Thus, in order that we may not quit the example of feldspar, such in this substance is the arrangement of the natural joints, that the molecule resulting from it is an oblique-angled parallelopi- pedon, in which the three plane angles which concur to the formation of one and the same solid angle, form among them a first angle of 90°, a second of 120°, and a third of inland a half; and these angles will be constantly the same in specimens variously crystallized ; in those which will give by analysis barytes or potash, as well as in those which will exhibit no vestie^e of it. And not only may we estimate by observation combined ■with theory the angles of the integrant molecule, but we even succeed in ascertaining the relations between its di- mensions, and there results a geometrical form perfectly determinate, which is the same in all the individuals of the species, and which presents as it were a fixed point in the midst of the oscillations of all the other characters ; so that we may even say, that in general the bodies of each species touch closer in the rip-sults of the theory relative to their structure than in those of chemical analysis. T do not pretend to raise the character I have just mentioned above its real importance. I am even led to suspect the predilection which 1 ought naturally to have for that character which belongs to a branch of mineralogy which I have cultivated with particular care. But this predilection does not prevent me from stating a trutl^ which T think useful to the progress of science ; which is> that this character, borrowed from the structure, ought to have a great influence in the distinction of the species; and by neglecting it we deprive ourselves of one of the most advantageous methods for the formation of an exact and re- gular system. It may be objected, that the determination of the inte- grant molecule of a body is frequently a delicate operation, which requires minute experiments, and besides presup- poses a knowledge of calculation which the whole world is not in possession of. But chemical analysis has also its difficulties, and is not the affair of a moment. It requires a good deal of art to employ the most proper agents for seizing and coercing principles invisible, and, if we may l>e allowed the expression, impatient to escape from the bands of the chemist: it requires art also that the operation may take nothing from the result that bek>ngs to it, and a then wanted ^o determine them, except characters less certain than that which is de- rived from the structure, it merely results that we ought to regret that this hst character has not a greater generality;- and' this very regret is a kind of avowal of its preeminence, ill every case in which it can be employed'*. Will it be said that there are forms of integrant mole- cules which are common to substances of different natures? I si^aU observe, in the first plao», that this does not take place except with respect to solids which have a peculiar character of regularhy,. m such a manner that in all the other cases the form of the integrant molecule is sufficient of itself for determining the species. I shall answer after- wards, that most of the substances which have one com-^- mon molecule (and this may be said of aH those which, like- the ductile metals, never Imve a lameHous texture) may be easily distinguished by other characters. For example, the cube agrees best as the integrant molecule with boraied magnesia, muriated' soda, sulphurated lead, sulphurated iron, &c. ; all of thera ascertainable independently of me- chanical division. In a wor(> : alf that I wish to infer from this discussion- is, that the character drawn from the structure ought to occupy a very distinguished rank among those which are made use of to njark the general charactsr {triage) of • Sometimes the rareness of crystals is alleged as a proof of the scanty resources furnished" l)y tbe character drawn from crystallization. This difficulty does not scan'i to be well founded, since a single crystal clearly de« fined, is sulficient to determine a nuilritude of irregular masses, wKiirh, with this crystal, would have relations indicative of an identity in nature: and if, by object in)^ that crvstali are rare, it is meant- to say that there are several- niineralo^^cal species which arc never presented under crystalline forms, I shall ask if these are properly species per ye, and not on the other hand* mixed species, in the production of which diffbrent species hare- coocurred ^ original OnCrystalhgraphy* 193 tirlginal bodies of one and the same species. It certainly has its obscure sides, and there are circumstances in which it disappears. Uut wherever it shows itself, there is a ray of light against which we ought not to shut our eyes. I shall add, that, with a hitle expertness in applying cal- culation to theory, we may decide if a given form enters into, or ought to be excluded from^ any given species* Thus we shall find that the cube which has been quoted among the varieties of carbonated lime is foreign to the crystalHzation of this substance*. Now it is easy to see of what service this adaptation of calculation must be, in order to separate the crystallized minerals into their re- spective species, assigning to each what belongs to it, and tVeeing it from what it nught have usurped. All that precedes leads us to an interesting consideration relative to the chemical composition of minerals : viz. that the principles which concur to form their integrant mole- cules must, as I think, be constant, both as to their quan- tities and their qualities, in such a manner that the sub* stances which cause a variation in the products of the analysis are foreign to the molecules, and merely interposed among them in the mass of the mineralf. We may com- pare a substance mixed with these additional principles to t^ertain salts with which other salts are accidentally united, as is the case with nitre of the first formation. When We make this salt undergo successive solutions and cry- stallizations in order to purify it, the liquid in no respect alters the figure of its molecides ; it only separates them from each other, and frees them from those of the other salts which were associated with them, and which had gone for nothing in their composition. In the same way the principles on which ihe differences between the analyses of various pieces of one and the same mineral depend, merely form with the substance peculiar to the latter a simple mixture, from which the integrant molecules would come out untouched, if power were not given to us to re- gulate, it' we may be allowed the expression, their de- parture];. From • Vide under the head Carljonated Lime, the variety which we have called ciiloid. t 1 even think that, irt the case in which we say that there is an excess of One of the principles in other respects ess&ntial to the composition of a mineral, the superabundant pait goes for nothing in the formation of the molecule, and ought to be ranked among heterogeneous and purely acci- dental princi|)les. ^ These are the accidental principles wl^ich produce a variation in cer- tain eiteri^l characters; such as colour, lustre of external surface, of frac- N 2 tur^, 196 On Crystallography. From these considerations it appears to me that we may define a species in mineralogy to be, A collection of bodieSy the integrant molecules ofuhich are similar., and com- posed of the saine elements united in the same proportion. This last condition generalizes the dcfinijion, and extends it to substances which, ha\'ing their molecules of the same configuration, differ essentially in the principles which compose these molecules. Some mineralogists are of opinion that these collections?- which I have called species ought rather lo be regarded as genera. But where then would be the species which would Subdivide the genus? Would these be crystals of cUfTercnt forms? It seems to me that these modifications, which in truth are the results of so many determinate laws, butTvhich after all belong only to local circumstances, such as the density or other qualities of the liquid, — do not fur- nish a sufficient reason for establishing specific distinctions between them. Thev do not touch the substance, and are confined to the giving of different envelopes to one and the same nucleus. Besides, on the supposition in question we^ should be embarrassed with unshapen masses, which surely do not deserve to be erected into species. The same an- swer applies to the hypothesis on which the species would form groups, one of which, for example, would compre- hend Bodies regularly crystallized; a second, concretions, ^c. But let us conceive that the molecules which pro- dviced the concretion had been freely suspended in a tran- quil liquid ; they would have assumed another arrange- ment, and might have formed crystals. The idea originated by the word species goes straight down .o the bottom of the substance, and dues not stop at simple windings. We should not be better founded in regarding as so many species the mixtures of a substance with accidental prin- ciples, which only modify the principal species, but do not transform it into another which may be really distinguished from it. Even these mixed bodies only belong to the ture, &c. Thus we fin4 at mount Vesuvius crystals of pyroxene (Auglt of Weruer), the surface and fracture of which have a very shining appearance, ■whereas amongst those of i^Iorway several liave a rough and dull surface, and their interior is not very shining. Nevertheless both are divided under the same angles, and have forms eitiier similar, or which may be referred to the same molecule; s) that the species to which they belong pieserves its unitVi in spite of the ditlerences of aspect which we have mentioned } and consequently these differences are all of them 3t mo^^t the index of a varia- tioain the principles which concur in 'any given way to the composition of the subsiance, but they do not anuounce any variatiou in the essential iind truly coiiotiluent priucif le». ' principal On Crystallography, \§1 principal specie?, because they admit of the existence, at least in part, of the predominant characters. If this was not the case, they ought no longer to occupy a place in the method: they ought to be thrown into the general appen- dix, in which are placed the mixed substances called rocks. And this shows how contrary it is K) the spirit of the me- thod, to place on the same line (as so many particular species) with the true species, marles, argils, schists, and other bodies, which are only fortuitous aggregates of species already classed in other places in the method, and no one of which imprints its character on the whole; so that we are even unable to decide to what species they ought to be referred, as being but a simple appendage. From all that I have said, we shall easily conceive how important it would be to determine by the aid of analysis, (with respect to each species) those principles which concur by themselves to the formation of the integrant moleculcj by operating on picked pieces, the composition of which contains only what cannot be dispensed with, without ceasing to be what it really is, and which had borrowed nothing, if we may be allowed the expression, from the liquid in which it had originated. We should thus have the Tnnit from which the analyses of other pieces remove more or less, according as the latter contain principles purely accidental, or if one of the constituent principles i« found there in excess. This limit would give what would be called the analysis of the mineral submitted to experiment, and the other results would make known the accidental diversities of which the composition is susceptible : they would serve to indicate to what term a certain principle has varied in its propor- tions, and to unveil the principles which have only a trans- itory existence, and are rather a surcharge with respect to the nuneral which contains them, as they do not contri- bute to its huegrity. I think I have sufficiently shown how much strength may be acquired by chemistry and mineralogy by their mutual cooperation. Without the former we should be ignorant in what class a mineral ought to be placed if it contains an acid, or if earths only enter its composition, or if it does not conceal a metallic substance under the ap- pearance of a simple stone. Without the latter art, it would frequently be difficult to refer to the type of the species the varieties which appertain to it. The one indi- cates the first link of the chain, and marks the point to which it ought to be attached ; but the intervention of the N 3 other IQS QnCTystaUography* other is necessary for continuing this chain and arranging the different hnks of it. I trust that this long discussion will be forgiven. T thought it necessary, because it appeared to nie that at no tin)e has the influence been sufficiently ackno\vledged,which mineralogy ouglit to have on a well -arranged mt-thod ; and because, if there are cases in which the mineralogist cannot refrain from saying to the chemist, Make me acquainted tvit/i the substance nhick you have analysed, — there are others in which the chemist, if he is cautious, ought to say to the mineralogist^ Make me acquabited tvith the sub- stance which I have analysed. M. Vauquelin, who adds to dexterity of operating a great accuracy of reasoning, ha's proved more than once, that he did not regard th£ consequences inferred from the geometry of crystals as useless in assisting us to fix the term at which the analysis ought to begin. Placed by circumstances beside each other, we have frequently consulted together on the subject of our inquiries, and the results which we attained, by two methods of interrogating nature so different, were mutually of service as guarantees by their conformity. I feel strongly the advantages which this cooperation has produced, and I am anxious that it should be publicly known, that it is m the Ecole des Mines in PVance that chemistry and crystallography, so long se- parated, have contracted a strict alliance, which bids fair to be of long duration. If we now resume the comparison between the me- thods of botanists and those of mineralogists, we may observe that the former are entirely founded on charac- ters furnished by observation of the external form, but the latter having a necessary connexion with the internal organization, which is constant in all the individuals of one and the same species, each of them may serve as a conmion model, in order to paint as if at a single stroke the entire species. In the mmeral kingdom, on the contrary, in which the external characters undergo continual variations, in which even the best defined forms are only evanescent disguises, nothing that speaks to the eye can serve as a foundation to the method. It belongs to analysis to lay this founda- tion, and to regulate the order of classification, making use on all occasions of the light afforded by crystallography. But this object once attained, the observer must be able to ascertain the substances classified by methods independent of 'Oti C'i'ystallograpU^, 1 99 by the close observation of every On the Identity of Columhlum and Tantalum, 201 every thing which may be presented in nature ; and the art of advantageously applying the method, leads an " expert eye to (ind the art of knowing how to dispense with it altogether, [To be continued.] _,, , - .^ . . . <__ • tlt't, i I t r«i I I >«. XXXI V. On the Identity of Columlium and Tantalum. By William Hvde VVollaston, M./). SecR.S,* W iTHiN a short time after the discovery of columbium by Mr, Patchett in ISOlfj a metallic substance was also discovered in Sweden by M. EkebergJ, differing from every metal then known to him; and accordingly he described the properties by which it might be distinguished from those which it most nearly resembled. But although the Swedish metal has retained the name of Tantalum giveu to ii by M. Ekeberg, a reasonable degree of doubt has been entertained by chemists, whether these two authors had not in fact described the same substances ; and it has been regretted that the discoverers themselves, who would have been most able to remove the uncertainty, had not bad opportunities of comparing their respective minerals, or tlie products of their analyses. As I have lately obtained small specimens of the two Swedish minerals tantalite and yttro tantalite. from which I could obtain tantalum, and was very desirous of com- paring its properties with those of columbium, Mr. Llat- chett very obligingly furnished me with some oxide of the latter, which remained in his possession. The resemblance was such in my first trials, as to in- duce me to endeavour to procure a ftirther su})ply of co- lumbium ; and by application to the trustees of the British Museum, I was allowed to detach a few grains from the original specimen analysed by Mr, Hatcheit. Notwithstanding the quantity enipioyed in my analyses was thus limited, I have, nevertheless, by proportionate oeconomy of the materials, been enabled to render my ex- periments sutlicienlly numerous, and have found so manjr points of agreement in ihe modes by which each of these bodies can or cannot be dissolved or precipitated, as to prove very satisfactorily that these American and Swedish specimens in fact contain the same metal : and since the » From Phil. Trnnf. 1809, Part IL + Phil, Trans, for 1 ao2. + Ffienkups j^cadcmia^s Ha7ullingar. 1802, Tp. 6H.—Juiirnal '^des Mines, vol. lii. p. 2*15. ** re-agents 90i On the Id or paste made over the fire with flour and water. The following experiments were made with a rod of five hundred series of plates, — whether with the one ivi which were two hundred plates of Duch metal, or in which there was none, but silver-leaf instead^ it is not necessary to* mention. 2 1st Sept. I8O9. One leaf of an electrometer made of Dutch metal kept flapping to and from the side of the 2;lass many times, when connected \\'\i\\ the electric rod. The ends of the rod being placed upon two* electrometers, — when the top of either of them vvastouched, the electrometer at the opposite end diverged more imme-*- diately, 22d Sept. The rod was placed at the tfottom of an electrometer ; one leaf was attracted to the side and flapped several times. — This experiment shows that the electric^ power of these piles or columns acts through a portion of air : I held the upper part of the electrometer in my hand during this experiment. 24th Sept. A small piece of Dutch metal was attracted up to the ball at the zinc pole of the rod, and adhered to it. 4th Oct. A very light, ivory needle, turning on a point (like a magnetic needle), was attracted by the rod ; when a finger or a key was placed near one end of the needle, and the ball at the en(l of the rod also near the same end on the opposite side, the needle vibrated backwards and forwards. The needle was insulated, I believe, by a piece of anTiber. ■ The needle, after having been touched by the silver-end pole, evidently receded from that pole; or, as it is commonly called, was repelled, having been charged with Method of fit ting vp Mr, Jbe Luc*s Electric Column, SOY with the same kind of electricity as that end of the rod pos- sessed : — the same effect was perceived when charged by the zinc pole. One leaf of an electrometer (Dutch leaf) moveJ, when one of the balls on the rod was placed over the top, without being in contact with it. 15ih Oct. The ivory needle vibrated between the balls oF two rods, one of which was at the zinc pole, the other at the opposite pole. One column which I have made, consists of about 50O plates, each about ^th of an inch in diameter, I have put at the zinc end a piece of cork cut Hke the head of a snake of eel, and at the other end anmher to resemble a tail. Thi* column may be called an artiticial electric eel (Gijmnotus electricus) : it is not inserted ii> a tube Hke the others, ai silken string runs through the centre of the plates, which may be drawn tight ; then womid round a pin which is m the mouth, or may be loosened if desirable. This eel act* powerfully on the electrometers. The power appears to me to vary much more than that of the columns in tuixes : pro- videtl the outside of these tubes be dry, I do not know thar the strength of their electric power changes, 18th Oct. Three rods, each of 50Q series, were supported apon insulated stands, and a plate of copper suspended afe the silver pole of the combined apparatus ; another plate was placed under this, (as in the common electrical experiment of the dancing images,) one very small piece (or more) of tissue-paper was attracted up and fell down, and a little image of the same paper reared up, and once remained sus pendeJ to the upper plate, but I could not make it dance up and down. 22d Oct. One ball or both ? of Cavallo'^s pocket electro^ meter diverged, when three rods were combined ; the pith* balls are on wires. With th^se three rods I could not per- ceive the metallic taste in the mouth, whidi is so perceptible even with a single piece of zinc and silver placed against the- tongue. When the ball or baits ? of the electrometer moved^ the opposite end of the apparatus was touched. A small pith-ball, suspended I believe with 2bsingh thread of a silk- worm, vibrated between two fixed pith- balls, one of which was connected with the apj>aratus, the other communicated with the tabfe. ead Oct. A coated jar had a shght charsje ffiven to it with one of the electric rods. When the zii^c pole charged the inside of the jar, that side gave signs of a iJiirms- stare (a«pring, at the birth, were perfectly consistent with the theory of Mr. Cline; they were remarkably large : and 1 observed, that the length of their legs, when they were only a few days old, very nearly equalled that of the legs of their fe- male parents. I examined the same animals when five years old, and in the depth of their chests and shoulders they very little exceeded their male parent; and they were consequently of little or «o value ; whilst other mules, which were obtained from the same male parent (a Spanish ass), but from mares of small stature, were perfectly well proportioned. 1 have never seen the little mule, which is uropagated from the female ass and the hor^e, nor even a delineation or description of its form ; but I do not enter- tain any doubt that its chest and shoulders are excessively deep anu strong, conjparatively with the length of its Icgsf and that, on account of this peculiarity in its furm, it has been so frequently shown on the Continent, under the^ liame of a jumart, as the pretended offspring of the marfe) and the bull. "1 . h In opposing the theory advanced by Mr. Cline, it is not by any means my intention to enter the lists with him, as 4 physiologist ; but, as a farmer and breeder of animals of different species, I have probably liad many advantages, 0 3 which till On the comparative Ififlumce, ^c* which he has not possessed ; and my conclusions have been drawn from very extensive, and, I believe, accurate obser- vation. There is another respect in which the powers of the fe- male appear to be prevalent in their influence on the off- spring, and that is relative to its sex. In several species of domesticated, or cultivated animal (I believe in all), parti- cular females are found to produce a very large majority, and sometimes all their offspring, of the same sex; and I have proved repeatedly, that, by dividing a herd of thirty cows into three equal parts, I could calculate, with confi- dence, upon a large majority of females from one part, of males from another, and upon nearly an equal number of males and females from the remainder. 1 frequently en- deavoured to change these habits by changing the male 5 but always without success ; and I have in some instances observed the offspring of one sex, though obtained from different males, to exceed those of the other, in the propor- tion of five or six, and even seven to one. When, on the contrary, I have attended to the numerous offspring of a single bull, or ram, or horse, I have never seen any consi- derable difference in the number of offspring of either sex, I am therefore disposed to believe that the sex of the off- feprin^ is given by the female parent ; and the probability of this seems obvious in fishes, and several other species of animals which breed in water ; and though the evidence afforded by the facts adduced is not by any means gf suflficient weight to decide the question, it probably much exceeds all that can be placed in the opposite scale. In oviparous animals, I have had reason to think the in- fluence of the female parent quite as great as amongst the viviparous tribes, though my observations have been more limited, and less conclusive. In viviparous animals, the size of the foetus is affected by the influence of the male parent, and, in some instances, not inconsiderably; but the size and form of the eggs of birds do not appear to be in any degree changed or modified by the influence of the male; and therefore the size of the offspring, at the birth, must be regulated wholly by the female parent ; and this circumstance permanently affects the form and character of the offspring! The eggs of birds, and those of fishes and insects (if such can properly be called eggs), appear to resemble the seeds of plants, in having* their forms and bulk wholly regulated by the female parent ; but nevertheless their formation appears to depend on very different laws. For the eggs, both of birds and of fishes and insects, attain their On the Fossil Bofies of Hoi'ses and Wild Boars f 2 1 5 tiieir perfect size in total independence of the male, ancl the cicatricula, the vitellus, and the ctialazae have appeared (I believe) to the most accurate observers, to be as well organized in the iinimpregnated as in the impregnated egg: in the seed, on the contrary, every thing relative to its internal organization appears dependent on the male parent. Spallanzani has, however, stated, that many plants produced well organized seeds, and even seeds which vegetated perfectly, under circumstances in which it is not easy to conceive how the pollen of the male plant or flower could have been present. But the Italian naturalist ap- pears to have blundered most egrcgiously in his experiment; or (which I conceive to he more probable) he became the dupe of the refined malice of his countrymen ; for, I re- peated his experiments under very favourable circumstances, and with the closest. attention, but I fiiiled to obtain a single seed. The gourd alone produced apparently perfect fruit, and the seed-coats acquired their natural size and form; and in this respect the growth of its seeds appeared to be> like that of eggs, wholly independent of the influence of the male. But the seed-coats of the gourd were perfectly empty, and T could not discover, at any period of their growth, the slightest vestige either of cotyledons, or plu- mule, nor of any thing that appeared to correspond with internal organization of a seed of the same plant, under different circumstances. Spallanzani has not, I believe, mentioned the species of gourd upon which he made his experiments: the common, or orange gourd of our gardens, was the subject of mine. In comparing the mode of the formation and growth of eggs with the observations I had previously made on the growth of seeds, I have been favoured with the very able assistance of Mr. Carlisle, for which 1 have on this, as on many other occasions, tg acknowledge much obligation. 1 am, my dear sit*, with great respect, sincerely vours, Downton. May 20, 1809. ThOMAS AnD. KnIGHT, OCXXVII. On the Fossil Bo?/es of Horses and Wild Boars, By G. A. CuviER*. -I HE above are the only species of animals which remain to be described, in order to complete the history of qua- f Jan. du Museiim, tome xiv. p, 83. O 4 drupeds 216 ,' 'v \ >i \ . On the Fossil Boms ^^xr-\\. yl:. ' dmpedft with' hoofs, whiqh .l)ave been foivnd in the fossil state; and our task will be the easier, as they have been dug up.frohi loose soils only, for ,the most part of recent for- mation j and such of their remains as have been collected, canwot enable us to distinguish them from living species. Article T. Fossil Bones of Horses. These are as common in loose strata as the bones of any other large animal, and yet little mention has been made of them in workfe on fossil bones; either because their pre- sence was regarded as a very simple occurrence^ not de- serving of attention, or because they were not recognized as being the bones of horses. There are various proofs of this last oversight,which would appear very extraordinary if we were not aware how super- ficially fossils and petrifactions have been examined. Thus we find in the Traile des Monstres of Aldrovandus, published by Bernier, p. 37? two horse's teeth given as the teeth of giants, while in the Museum metallicum of this author, published by Ambrosinus^ p. 830, teeth of the^same animal are represented correctly. In another memoir we have said that Lang, in his His- toria Lapidum Jiguratorum Helvetice, tab. XI./". 1, 2, had taken a horse's tooth for the tooth of a hippopotamus. We may add that Kundmann has engraved others, without knowing what to make of them {Rar. Nat. et Art, tab. IF. f. 4 and 5) ; and that Walch, who bad received them from Quedlimbourg, confines himself to remarking their resem- blance with those of Lang and Kundmann, without endea- vouring to determine them more precisely [Monumens de Knorr, II. sect. II. page 152). The number of authors who have been more adventurous is very small ; such as Bourguet, who quotes a single jaw- tooth found at a depth of 60 feet, on digging a well near Modena {Traite des Petri ficaiions) ; and Kome de Tlsle, who reckons in the number of the subjects in the Cabinet of Davila, a fossil horse's tooth in its alveolus, near Caii- stadt. {Cat. de Davila, III, page 230). It is certainly to this silence. oV most naturalists, with respect to the fossil bones i>f horses, that we are indebted for the silence preserved by M. Faujas on the same subject in his Geologic, although he nnght have lakt-n great advan- tage of it to support his favourite opinion respecting the identity of fossil animals with those of the present tinjc. In fact, the fossil bones of horses cannot be distinguished from the bones of living horses 3 and nevertheless we find them of Horses and Wild Boars, %\1 ijiem most assuredly in the same strata which contain un- known an inn al 3. We have already said that there were thousands of horses' teeth in the celebrated depot of bones of elephants, rhino- ceroses, tiy^ers, and hyaena^, discovered in 1700 near Can- Stadt in Wirtcniberg: their association , with the elephants seemed to be a general occurrence. We have seen wjth our own eyes hundreds of bones and teeth of horses dug up from the canal of the Ourcq, in the spot from. which elephanis' bones also had beea taken ; and among the horses* bones there were some com-; pletely peirlfied. In the quarry of Fouvent le Prieure, in the department of the Haute-Saone, from which bones oi elephants and of hyaenas have been procured, several bones and teeth of horses were at the same time found, which have been also sent to our Museum. M. de Dree is in possession of a piece of a horse's jaw found at Argenteuii, nearly in the same spot wiih an ele- phant's jaw. M. Fabbroni has sent me drawings of several similar portions dug up in the upper Vdl d'Arno, with bones of elephants, rhinoceroses, and mastodonti with straight teeth. Fmally, M. Fischer has procured me scmie drawings of horses' teeth brought from the Bergstrasse, and jilaced in the Cabinet of Darmstadt. I am convinced from these observations, that if we have not more frequently heard of horses' bones dug up with those of elephants, it has arisen from the former having been regarded as less interestmg. We shall not repeat what we have said of those which we sometimes find in osseous strata : but it is in recent al- hivialions that most of them are found, as might reasonably be expected. There is scarcely any valley into which we can dig in any direction, without finding horses'bones in the depositations made by rivers : the valley of the Seine, that of the Somme, and without doubt several others, are full of them, , M. Traulle sent me several specimens from the banks of the Somme ; aud I have seen them myself dug up from the foundations of the bridge now constructing opposite the Military School. These last are not interesting, because they have been de- posited since our continents assumed their present form : the former, however, being those which accompany the l)ones of elephants and tigers^ are of an anterior order of things. f 1 » On the Fossil Bones things. Did the horses to which they belong rciemble those of the present day in every respect ? I must confess that comparative anatomy cannot answer this question. T have carefully compared the skeletons of several va- rieties of the genus Equus, those of the mule, the ass, th6 zebra, and the couagga, without being able to find in them a character sufficiently fixed to entitle me to hazard a de- cision. If we could obtain an entire fossil head, we might perhaps set on foot some comparison ; but with the other bones, most of which are mutilated, we can obtain no result. We may therefore rest assured, that one species of the horse genus served as a constant companion to the elephants or mammoths, and to the other animals of the same aera, the bones of which fill our large basins; but it is impossible to say in what respects they resembled any of the species koown at present. It only now remains to point out the characters by which we may distinguish the bones of horses. As it is with the ox and the buffalo that they are most liable to be con- founded, it is with these that we must compare them. The upper grinders of horses are prismatic, like those of the ox and buffalo, and marked in the same way with four crescents ; but they have besides a fifth, in the midst of the inner edge. The lower grinders are more compressed, and have four crescents in the horse as well as in the ox ; but instead of being parallel in pairs, they are alternate, the first of the inner edge corresponding to the interval of the two of the outer edge. The shoulder-blade of the horse has its spine more ele- vated at the upper third part of it, and decreases from thence to the acromion. In the ruminating animals there is also an elevation at the same spot ; but it is at the lower extremity, and at the acromion, that the spine is most pro- niinent. In the humerus of the ox, the great tuberosity rises far above the rest of the upper head, and there is only a groove? for the biceps humeri ; in the horse this tuberosity does not rise more than the rest, and there are two different grooves in. front. The camt-I and other ruminants resemble the horse more than the ox in this respect. The cubitus of the ox, although attached to the radius, may be distinguished throughout its whole length ; that of the horse is entirely lost from its superior third part, being •nlv marked afterwards by a kind of thread. The of Horses and Wild Boars. 510 The lower head of the radius of the horse is divided into two fncels, by an almost perpendicular ridge ; thjtt of the ox is divided into three^ by two very oblique ridges. The ox has one bone less in the carpus than the horse, because its os trapezoides is confounded with the great bone. Every person is acquainted with the difference of their me- tacarpus and their hoofs. The ischion of the ox has its tuberosity higher than that of the horse, and the os ileum oFthe latter, on the contrary, is higher at its upper angle : this occasions the striking dif- ference in the crupper of the two animals. The femur of the horse has three trochanters ; that of the ox has only two, and the great trochanter is less elevated. The lower head of the tibia of the ox is rectangular, and has at its inner edge a facet for the articulation of the fi- bula ; that of the horse is very oblique, and almost trian* gular. The same difference of obliquity is discernible in the astragali : that of the horse, besides, has but a very small facet for the os cuboides ; (hat of the ox rests on this bone nearly the half of its inferior head. The OS scaphoides of the horse is much larger than it» cuboides, and remains always distinct from it : in the ox these two bones are equally large, and are always com* pounded. The horse has only one os cunciforme, and the ox has two. The differences of the metatarsus and of the hoofs, which have occasioned those of the tarsus, are known to all natu-» ralists. By means of these short and simple characters we may easily distinguish the bones of the extremities of the two species. Each of the vertebrae, separately examined, would also furnisli characteristics ; but the detail would be endless, and it is very rare that we find vertebrae isolated from other bones. I think I have now furnished geologists with all that is requisite. Article II. Of the Fossil Bones of Wild Boars, I do not find many indications of the teeth of these ani- mals in authors : all those that I have seen, came from peat mosses, or other recent soils ; and I do not know if thev ever accompanied the bones of elephants. Walch mentions the vertebrae of a petrified hog, alluded toby Luid, and after him by Argenville; but we cannot trust to such authors or their descriptions. Gmelin, Wal- lerius. fpo On the Fossil' Bo7ie^ '■ lerius, and others whom I have consuUed, do notspeak at all of this kind of fossil. There is ncvcrlheless in the Museum Beslerianum, plate XXXI, a piece of the fossil tooth of a wild boar, under the singular name o'i pscudo-coroua-augiuna ; and Grew says that the cabinet of the Royal Society of London has similar specimens : but neither of these authors assigns the origin or the species. M. Delannay, in his Memolre sur VOrigive des Fossiles accideiiteU des Provinces Belgiques, p. 36, relates, that in the. environs of Alost,on digging into a moss, *' they found the osseous part of a wild hoar unknown in Europe, and they considered what must have been the extraordinary size of the animal when alive.'* He adds, that what made the animal be recognized, " were the luhks, of a length in every respect astonishing.'' It would have been very easy to have added the length of these tusks, and some figure or description of this head. But geologists have rarely de- scended to what they considered as minutiae, and prtterred spending their tin^e in contriving; systems, to employing it in accurate researches : thus the above fact, which might have been made interesting, is totally useless. For my part, I have some teeth of wild boars which seem to, have remained long in the earth. I have some also stained black by the moss in which they certainly had been immersed ; but I am not acquainted with the precise origin of any of them, except of a tusk found on digging the foundations of the bridge of Jena, opposite the Military School, with several bones of horses, pieces of boats, and other artificial fragments. I have also a piece of a jaw brought from the mosses in the department of the Oise, deposited in the cabinet of the School of Mines. Both are therefore of very recent strata, and they do not differ iii the least from the living analogy. Adrian Cainper sent me the drawing of the lower half of the humerus of a hog or a wild boar, wliich had been trans- mitted to him from Hartz, but as to its precise position he knows nothing certain. The head of the Sus genus is so easily distinguished from all others, that we have no occasion to give its' characters. Its grinders represent on a small scale those of the masto- dontus with straight teeth, having also blunt tubercles furnished on their edges with smaller tubercles. In the wild boar, domestic pigs, Siam pigs, and Mada- gascar wild boars, the natural and complete number of grinders is seven. The of Horses and IF ild Boars', 221 The posterior lower grinder has five groups of tubercles ; that of the iippeY has six. The eight which precede" them have each four groups rapged in pairs. The iburih on each side has three groups ranged in a triangular form ; anc) ^the three anterior, having their tubercles on a single line, ^r^ almost sharp-edged; ,id-o io A'ycld biiJhlriJtri 3rji 1 The anterior tooth fall? very edifly in pur European pi^s j and I never found ii;,in the babirous'^a, the number of which; should be six, but it is frequently five only, in consequence^ of the casting of the anterior tp.Qtb : I found but six als» in two peccaris. ;-i)r': .. ., notriyj.f; -jiU .mii r>'Mv.>.jU oJ The wild boaraf Ethiopia llaS'dnly,|brechteeth^ all cotp-j posed of cylinders lied together like, the jvamins? of tho^e o^ the elephant, and presenting circles at their, surface wherib, they are filed down. They are very Uneqi>,al ; for the ]i\^t has no less than twenty-three circles ranged in three lines..j Every species has its peculiar form of tusks ; but all the tusks and all the grinders which I have pbserved, were siipi- lar to those of the common wild boar. .- The extremities of the Sus genus have a great resemblance. to those oF the ruminating animals. As it is most hkely that the.;bones of the former may be;cpnfounded with thpse of ' stags and sheep, it is with these last that we ought, to; compare them. ' .. The shoulder blade, like that of the horse, has the spine flattened in iVont, and more prominent in the upper third, part, where it forms a hook bent backward. The great tuberosity of its humierus is very high, as in the sheep ; but it becomes broader behind, and is followed by a broad reentering arc. S ,% . '.' ,-: •: The cubitus is very broad ' ai)d 'distinct throughout its, whole length ; the greatest part of it in the sheep is attached.. In the stag it is at least itiu.ch more slender. The carpi have a close resemblance, with this diflference,' that the trapezoidal bone is distinct in the Sz^i genus, where-; as it is close in the ruminating animals; and the unciform bone is narrower, whereas the os scaphoides is broader. The differences in the femurs are almost incapable of de-. scription in words ; but the tibia may be recognized be- cause it is shorter ; its inferior head is square, and does not decrease from back to front, and has no articulation for the fibula. The chief ditlerence of the tarsus depends on the small cuneiform bone, on the sole of the fifth toe, and on ti)e OS scaphoides remaining distinct from the cuboides. As to the metacarpi, the metatarsi, and the toes, they cannot ke confounded. XXXVIII. JSx- [ 222 ] XXXVTIT. Extract from a Memoir by M, Mathieo^ ofi the Discovery of several Blocks of orbicular Granite re" cent ly found in Corsica *, J. HE insulated block of orbicular granite which was found in Corsica in 1785, on the small plain of Talavo, half a league from the sea, on the shores of the Gulf of Valin- co, on the Istria road, not far from a place called la Stan- 2ona, and which Messrs. Sionville and Barral \vcre the first to describe, fixed the attention of mineralogists, from the singular form assumed in this rock by the white semi- transparent feldspar and the amphibole or horne blende of a deep black, a little greenish, arranged in several concentric circles, which had given rise to species of round or oval bowls, immersed in a confused mixture of the same two mineral substances which form the basis of the rock. This stone, so singtilar by the system of its formation, and by the effect which it produced when polished, made it very much sought-after for cabinets, and it soon became rare and of high price. In vain did Messrs. Barral, Sionville, and after them Do- lomieu, Besson, and several other mineralogists, make in- quiries after the rock which had given birth to the insu- lated and partly smooth block, which some convulsion had transported and buried in the small plain of Talavo 5 — all iheir pains were useless. Notwithstanding their want of success, a Corsicanna- tnralist, M. Ram passe, was more fortunate ; because his knowledge of the language and manners of the inhabitants of the mountains admitted of his pursuing, with a hammer in his hand, the chain of mountains from which he pre- sumed that the block of the orbicular rock of Talavo must have been torn at a very remote period by the action of the sea. M. Rampasse has executed this arduous journey, during which he collected a fine series of rocks and other mine- rals ; but he was not more fortunate than the rest with re- spect to the globular granite. His inquiry, however, made us acquainted with the position of a porphyritic rock crowded with globular bodies, in general larger than those of the stone found at Talavo ; and the formation of which, without being absolutely the same with the latter, never- theless resembled it considerably j but the rock, of a differ-r * Annalti du Mutium d'HisloiTt NaturelUf tome xkv. p. 82, cut Blocks of orbicular Granite discovered in Corsica* ^$ Itnt colour, was softer^ and did not receive the brilliant polish of the orbicular granite. M, Rampasse brought to Paris some magnificent specimens of this porphyry with large globules. This variety was not to be found in any cabi* nets. It results from these details, that all hopes were given up of other masses of granite similar to that of the plain of Talavo, when a particular circumstance brought to view several other blocks, which are said to exist in their naiiva position, a leage from Talavo, and resting on the same rock which gave birth to them. It is to M. Mathieu, captain in the imperial artillery^ and commanding at Ajaccio, that we owe tlie first infor- mation on this discovery, consigned in a manuscript me-» inoir, accompanied with a topographical plan, and a verjs excellent specimen of this granite, which is of precisely the same form with that which was formerly discovered. " This superb production,'* says M. Malhieu, " is found in considerable masses on the estate of Sartene, the pro- perty of M. Jean Paul Roccaserra : its present situation is about three fourth parts up a very steep mountain, from which it has been msulated by accident; it is in blocks smoothed (arrondis) i?i consequence of decomposition, which blocks are comprised within a space which does not extend beyond four himdred square metres. The base is a granite composed of semitransparent quartz, of amphibole with large crystals, and of mica in a small quantity : sometimes shades are discovered which give a feeble appearance of the globulous system. The rest of the mountain is, like thosa. adjacent, composed of a granite of quartz, feldspar, and mica." M. Mathieu adds, that the lichens and mosses which covered the blocks of this new orbicular granite and con- cealed its characters, did not permit those who visited the same mountain to see that the discovery was owing to tho recent separation of tivo parts of one block* The distance of the position of the ancient block of Talavo from the Rizenare, a river which washes the foot of the mountain oa which the recent discovery has been made, is one myria- metre and a half. M. Mathieu does not think that this liver has ever been capable of transporting this old block of granite to such a distance; and he is perfectly right : but when he presumes that, " in very remote ages, this same block has been discovered in the Rizenare, and thence trans- ferred by the care of an architect to the spot where it was to he cut with the cA/^e/,"— this conjecture does not seem to rest 824 Blocks of'orhicidar''GrdnitiB- he retamed his activity of body and all his energy and sagacity of intellect; He was warndy interested in all new subjects of science ; and several times, in the course of the last year, witnessed or assisted in some experiments that were carried on in this theatre, or in the laboratory below. ^^ Smce the death of Newton, (if I might be permitted to give an opinion,) England has sustained no scientific loss" so great as that of Cavendish ; but this loss is less to be re- gretted, since, like his great predecessor, he died full of years and of glory : his name will be an object of more venera- tion in future ages than in the present moment :— though it was unknown in the busy scenes of life, or in the popu- lar discussions of the day, it will remain illustrious in the- annals of -science, which are as unperishable as that natur»^ to which they belong : and it will be an immortal honour to his house, to his age, and to his country." WERNERIAN NATI;RAL HISTORY SOCIETY. At the meeting on 3d February, the Rev, Dr. Macknight laid before tlie socitity a sketch of the mineralogy of the highlands of Scotland, from the Pass of Leny to Balahelish. Tbe general rock in this tract is mica. slate, with its usual subordinate beds, such as, of granular limestone, horn- blende slate, &c. It contains also, in some districts, beds and veins of leadglance, and indications of ironglance. Be- yond Zyndrum, the mica slate approaches to gneiss, till we pass Inverouran, where sienite appears, hi the neigh- bourhood of King's House, newer granite, feldspar, por- phyry and hornstoue are found ; and the adjacent country, as might be expected from the decomposition of these rocks, presents, for many miles, an unusual aspect cf bleakness a,nd sterility. Glencoe, which is singularly interesting, both in a picturesque and in a mineralogical point of view, consists of hornstoue and compact feldspar, in beds subor- dinate to the primitive rocks, and capped with porphyry. At the bottom of Glencoe, mica slate again appears, and is ^ covered Hackney Literary and Philosophical Sociaty, 23 r covered with the formation of clay-slate, which affords the well-known quarries of Balahelish. Thus, according to Dr. Macknight;, it appears, that the relative positions of the great formations which occur in, the highlands of Scot- land, correspond to the principles of the geognosy of Werner. At the same meeting, Professor Jameson read some ob- servations on the universality of rock and metalliferbus formations, preliminary to a short account of some speci- mens of a particular formation of lead-ore found within' fifteen miles of Dunkeld in Perthshire. The formation ap- peared to be almost the same with that which occurs at Strontian in Argyleshire ; and it is therefore possible that- it maybe a source of wealth to the proprietor. y-' At this meeting also thi^ secretary read some new and in-' tcresting observations on the natural history of the common Greenland whale, by Mr. Willian Scoresby, junior, of Whitby ; and exhibited a correct drawing of that animal by the same gentleman, differing materially from the figures hitherto published. . HACKNEY" LITERARY AND PHILOSOPHICAL SOCIETY. We have great pleasure in announcing the formation of institutions calculated to diffuse useful knowledge. Of this description is the Hackney Society. It consists of two classes. First, Ordinary members, who contribute to the funds, enjoy the use of the books, &c. Secondly, Honorary, consisting of such gentlemen uhose association may re-;- fleet honour on the society, and whose opinion of the la-, hours of its members may be such as to impress them with: sentiments of regard for such a mark of the society's re- spect. Ladies are admissible as members. ' The officers of this society consist of a president, .tw<^ vice-presidents, two secretaries, a treasurer, and six com* njittee, who are to be chosen from the ordinary meni*- bers by ballot or^croll at every anniversary meeting. ; The meetings on Tuesday evenings are to be principally; occupied by literary conver?ations, and reading such papers on scientific or literary subjects as the society may be fa- voured with. The subjects for conversation, and books for the library, are to comprehend the mathematics, natural philosophy and history, chemistry, polite literature, antiquities, civil history, biography, questions of general law and policy, commerce, and the arts. The purchase of philosophical instruments, aud patro-. P 4 nizing S32 French National Institute. — New Books. nizing lectures on philosophical subjects, also form a part of the plan of this society. FRENCH NATIONAL INSTITUTE. The clar A of history and ancient literature of the French Institute has proposed the following as the subject of a prize dissertation : " What were the people who inhabited Cisalpine and Transalpine Gaul, at the different epochs of history anterior to A. D. 410? — Determine the position of the capital cities inhabited by these people, and the extent of territory which they occupied. — Trace the successive changes that took place in consequence of the divisions of the Gauls into provinces.'' — The prize will be a gold medal of the vajue of 1500 francs. The memoirs may be written in Latin or in French, and must be transmitted to the Secre- tariat of the Institute at Paris on or before the 1st of April, 1811. XL. Intelligence and Miscellaneous Articles, JVIr. Brown, the botanist who accompanied Capt. Flin- ders in the late voyage of discovery, has just published the first volume of a work on the plants of New Holland, &c. under the following title ; " Prodromus FlorcB ' Novw Hoi' landice et Insulce Van-Diemen ; exhibens characteres plan- tarum quas annis 1802 — 1805 per oras utriusque insulae collegit et descripsit Rohertus Brown ; insertis passim aliis speciebus auctori hucusque cognitis, sen evulgatis, sen in- editis, praescrtim Banksianis^ in primo itinere navarchi Cook detectis." M. Ebel, of Bavaria, has recently published a geological work on the structure of the Alps, which is reported by the continental journalists to contain much novelty, and to co- incide entirely with the experiments made by Humboldt. According to Messrs. Ebel and Humboldt, it is not true that granite is the nucleus of the surface of the earth : on the contrary, we find as many strata of granite as of any of the other integrant substances of mountains. These strata of stones in the mountains have been formed by crystalliza- tion in the Sea of Chaos, and are found in "a great measure on the same line from Savoy to Hungary. According to these ideas, the earth resembles a prism of crystal, the edges of which have been worn away by the flux and reflux of the waters, without the ruins of these points having entirely filled up the hollows made. These ideas are c;cpected to lead Discoveries' at Pompeia, 233 lead to Important results ; but they will at the same time discourage those who still hope to find the solid nucleus of the earth. The geologists on the Continent now begin to abandon their own system, in order to embrace that of Humboldt and Ebel. Mr. Parkinson has withdrawn the Introduction to ike Kfwivledge of Fossils, announced at the end of his first volume oi Organic Remains of a former World, considering its publication as entirely superseded by Mr. Martin's ex- cellent systematic Outlines ot" the same subject. The third volume of Organic Remains is in considerable forwardness. In the month of October last, the viceroy of Italy and his consort visited the ruins of the ancient Pompeia, ac- companied by chevalier Arditi,superintendant of the Royal Neapolitan Museum. A fresh search having been made for antiquities a few days before by order of iheir majes- , ties, M. Arditi presented on the above occasion several pieces of ancient pitch, a vessel full of wheat, a piece of coral, several beautiful paintings, and a lamp of baked earth in the form of a leaf, and bearing a Latin inscription. This lamp was covered with a very fine varnish or vitrifica- tion, which gave it a silvery or pearly appearance. It seems to be a mistake therefore of some authors, when they inform us that this vitrification was not invented until the fifteenth century by hue de la Rubria, a Florentine sculptor. Their majesties having expressed a desire to have some of the ruins dug up under their own inspection, the workmen had the good fortune to find several pieces of money of va- .xious denominations : a qu^tntity of bronzes, among which was a very fine vase, and an urn for wine : some articles formed of bones ; a great quantity of glasses of various dimensions and shapes ; and in particular a great number of vases improperly called Etruscan, on which were Latin inscriptions. On the same occasion, their majesties found some works in marble, and in particular some comic masks : a few small but elegant altars, adorned with bas-reliefs and weights marked with cyphers in the upper part. Hitherto only a single subterranean apartment had been discovered at Pompeia, improperly called a cantino, but which ought rather to have been named crypto-portico: in the recent diggings one was discovered consisting of several storied. It is remarkable for having a pipe or tube of stucco placed in a corner, and intended for the conveyance of smoke. 234 Foreign Schools o smoke. This discovery seems to set at rest the question so long agitated by the learned ; namely : whether the ancients were acquainted with the use of vents or chimneys for car- rying off smoke ? In the same apartments were also found several pieces of marble and alabaster, valuable on account of the bas-reliefs and inscriptions with which they are adorned. Their majesties afterwards proceeded into a triclinium op dining apartment recently discovered. The walls of this magnificent saloon are covered with paintings of the most exquisite taste, and representing fishes, birds, and game of all kinds. Here there are three couches of mason work in perfect preservation, being the places in which the ancients rested during their meals. Adjoining the three beds, there Still exists a marble foot, which must have served as a sup- port for the table on which the dishes were placed. His majesty on quitting the ruins expressed a most ar- dent desire that the exertions made to expose them topuWic view should be continued, and has since issued the neces- sary orders to his ministers of finance. . The following account of the present state of the uni- versities and other seminaries of education in the new- kingdom of Westphalia, is published in the foreign jour- nals. The universities of tlalie, Gottinaen, Heluistadt,- Marbourg and Rinteln, contain in all 1207 students. There are, also, 52 gymna^na or classical schools in the kingdom, at which are educated 6, S3 1 children : the inferior schools, at which reading, writing, and arithmetic are taught, amount to 3,600, and are frequented by 233,338 children of both sexes. In each of the two great cities of Brunswick and Magdeburg there are 33 public institutions for every branch of education, besides private seminaries. In the public schools the hours of teaching are so arranged, that the children who attend them are generally able to earn their livelihood at the intervals. In the above two cities alone 900 scholars are instructed in the sciences. In short, on a moderate compulation there is a teacher for every 30 chil- drei; throughout the kingdom. The university of Jena is also described as being in a very flourishing condition. The number of students, which in 1807 scarcely exceeded 100, is now quadrupled. The Mine- ralogical Society established at Jena a few years ago is in great repute. In September last this society held its anni- versary Caution to apothecaries and Dmggislf, $35 VersarVj at which the celebrated M. Goethe was present. This ingenious author nv)w devotes ,the whole of his time to the study of natural philosophy. ' A society for the education of the blind has been lately established at Zurich in' Switzerland. The number of pu- pils is at present 50 : and what is singular, the chief master, M. Funke, is blind. He is described as an excellent teachcP and an ingenious mechanic. ^ ' The calamities experienced at different times in Switzer- land from the sudden rolling down of huge fragments of rock and other component parts of the mountains in the Grisons, have suggested to the government the propriety of employing M. Escher, a geologist of Zurich, to sur** vey that district. He has accordingly published the result of his inquiries, and it appears that the valley ofNolla; behind the village oi Thusis, and the valley of Plesner be- hind the town of Caire in the Grisons, are threatened with the visitation of avalanches> which can only be averted by the prompt adoption of the measures of precaution which h€ has suggested. - The following short article on volcanos appears in a re- cent French journal : — ** It has bec"n observed that, in the year 1806, at the moment of the dreadful eruption of mount Vesuvius, all the other volcanos with which we are acquainted vomited an increased quantity of flames, ^tna spread terror throughout Sicily, and covered Calabria with lava. Hecla in Iceland was as violent as ever, and the Peak of Teneriffe threw out red hot stones. Volcanos which were thought to be extinguished awoke with new fury. ^' The communication of volcanos with each other is hot doubtful. But are we acquainted with the conductor of the electrical fluid r — Is this communication effected by Subterranean passages, or by the medium of the atmo- sphere ? How does it happen that the above unusual phae- nomena take place at the same moment i" CAUTION TO APOTHECARIES AND DRUGGISTS. For the subjoined information, which we consider our- •elves imperiously called upon to circulate as widely as possible, we are indebted to a most respectable manufactur-* ing chemist, Luke Howard, esq., of Flaistow. A very large quantity oi' glass of lead has, by some means, found its way into the London market, as glass of antimony. This criminal imposition is sure to be delected, jn the ope- ration 538 Caution to Apothecaries and Druggists, ration to which the glass of antimony is chiefly applied, the making of emetic tartar; but it is highly needful, for the sake of the consumers of smaller quantities, as in the vi- tnun ceratuvi, and v'murti antimonii, that the following di' stinctive characters of the two be extensively circulated, in order that those, who may have bought the article withiiv twelve or eighteen months past, may assure themselves of its being genuine. The public health, and even the lives of some patients, may be considered as at stake on the occasion. Glass of antimony has a rich brown or reddish colour, with the usual transparency of coloured glasses. The glass of lead in question is of a deeper and duller colour against the light, is much less transparent, and even, in some samples, quite opake. The specific gravity of the true never exceeds 4*95, that of \)[iit spurious, or lead glass, is 6*95 : or, in round num- bers, their comparative weights are as 5 to 1, Let twenty grains be rubbed fine in a glass mortar, add- ing half an ounce of good muriatic acid. The true dissolves, with an hepatic smell, the solution is turbid, but has no sediment. The spurious turns the acid yellow, giving out an oxymuriatic odour, and leaves much sediment. Let a little of each solution be separately dropt into wa- ter. The true deposits oxide of antimony, in a copious white coagulum ; or, if the water has been previously tinged with sulphuret of ammonia, in a fine orange preci- pitate— The spurious gives no precipitate in water, and in the other liquid, one of a dark brown or olive colour. A solution of the spurious in distilled vinegar has a sweet taste, together with the other properties of acetate of lead. A very small mixture of the spurious may be detected, by its debasing, more or less, the bright orange colour of the precipitate, thrown down by sulphuret of ammonia from the solution in any acid. The sanjples of the spurious, hitherto detected, are of a much thicker and clumsier cast than the genuine ; but the appearance is not to be trusted, and no specimen should be allowed to pass, without a trial either of the specific gravity, or chemical properties. John Morison, living at 143, Holborit Bars, who had the misfortune to lose both arms by the discharge of a can- non, has invented a curious set of instruments, so well adapted for almost every purpose of life, that the want of those limbs to him is wonderfully supplied ; and he under- takes to maka artificial legs, arms, and instruments, on a new List of Patents for new Inventions. 237 new principle. The Society for ihe Encouragement of Arts, Manufactures, and Commerce, being convinced of their great utility in affording help and comfort to unfor-' lunate persons in his situation, lately voted him their silver medal and 40 guineas for his ingenuity. LIST OF PATENTS FOR NEW INVENTIONS. To Joseph Stephenson, of Mortimer Street, Cavendish Square, in the county of Middlesex, p]nm!)er, for a machine for filtering and purifying of water.— Feb. 27, 1810. To John Justice, of Dundee, in North Britain, ironmon- ger, for his improvements in the construction of stove-grates calculated to prevent or cure smoky chimneys, and pos- sessing other advantagQS over the stove-grates in common use. — March 6. To Thomas Scott, of Holborn, in the county of Mid- dlesex, musical instrument maker, for his improved Ger- man flute, ciarionette and oboe. — March 12. To Thomas Robinson, of Roberts-Bridge, in the parish of Salehurst, in the county of Sussex, brewer, for his mash- ing machine. — March 12. To John Kent, of Southampton, architect, for his new and expeditious method of moving all kinds of goods or materials to high buildings or from deep plrices. — Mar. 12. To Thomas Grant, of Bideford, in the county of Devon, esq., for his method of making paint or varnish from a new discovered fossil, which will be of great public utility ' in painting of ships and in various manufactories. — Mar. 22. To Michael Shannon, of Berwick Street, in the county of Middlesex, architect, for certain improvements in the art of brewing, which were conniumicated to him by a Jearned foreigner since deceased. — March 22. To- Johann George Deyerlein,. of Long Acre, in the county of Middlesex, tool-maker, in consequence of cer- tain inventions by himself, and of communications made to him by a native of Germany, for a machine, new prin- ciple, or method of making bricks and tiles, and also by means thereof, and of clay, loam, or similar materials to those commonly used in potteries, to make all sorts of mouldings, beads, tubes, gutters, channels or cylinders to convey water, smoke, or any fluid or soft substance.— jS'Iarch 22. To John Gregory, of Islington, in the county of Mid- dlesex, builder, for his new method of tunning or cleansing ales and beers into casks. — March 22. Rairi ^S Meteorology^ Rain Table, ly the Uev. J. Blanchard, of Nottingham, . (U 1809. u s 15 u c 1— t Ox 11 e g ^ M a 1 X u i 1 C d 0 •a 1 '^ 3-98 2-61 4-66 6-58 5-27 Jan. 8-44 2-91 5 22 3-50 1-57 4-48 1-80 Feb. 4-31 1-86 3-29 2-59 2-94 2-58 1-96 3-11 4-53 4-28 5-74 1-69 Mar. 0-00 0-94 0-44 0-82 0-48 0-43 0-35 0-53 i-13 0-72 0-62 0-7^5 April 3.95 3-46 1-70 2-10 3-05 2-11 0-96 1-59 2-20 1-69 1-50 2- 1-5 May 1-07 0-S6 1-83 1-59 0-45 2-9G 3-42 3-39 3-85 4-55 2-66 1-80 June 2-38 1-20 2-06 2-24 3-24 2-01 2-45 3-10 4-26 3-2.4 3-79 2-45 July 3.45 3-58 2-00 2-87 2-38 2-28 1-79 400 3-45 3-28 3-08 1-44 Aug. 3-70 2-64 4-38 4-53 588 4-61 3-85 6-12 7-25 9-73 9.59 4-50 Sept. 3.34 2-90 4-13 3.90 3-10 4-29 4-22 4.75 5-57 6-3t 6-11 3.1^3 Oct. 0-60 0-22 0-28 0-75 0-56 1-41 0-61 0-87 1-66 1-16 . MO 0-31 Kov. 1-30 1-38 1.91 1-70 1-90 2-25 2-14 3-87 -2-80 4-11 2-56 MS Dec. 1 5-53 3-00 2-67 i-79 2-42 2-74 4-68 5-74 7-08 8-02 8-85 1-81 38-07 24-95i29-91 28-38 27-97 31-65 29-10 41-73 ,30-36 52-41 50-08 23-01 Meteorological Table, by Dr. Clarke, of Nottingham, ■ Thermometer. Barometer. Weather. Winds. S S 1 a* 0 1 3 i •1 13 ^ ^ § ^ 0) >>, Is :5 w CO • r, ^ ^\^ H H 43 17 35-29 14 30-05 28-65 29-44 MS 18 13 14 18 9 5. 54 30 43-00 14 30-33 28-68 29-62 0-74 18 10 2 3 33 16. 62 30 44-00 10 30-38 29-00 29 -9P 0-40 26 5 22 6 9 15 56 28 42-76 13 30-36 28-97 29-73 0-54 13 17 16 1 14 18 77 38 57-6! 9 30-26 29-23 29-84 0-43 24 7 10 13 19 13 74 45 57-71 18 30-45 29-27 29-84 0-62 21 9 11 7 15 14 78 46 59-64 10 30-12 29-39 29-8{^ 0-24 17 14 24 4 10 18 76 48 60-69 8 29-97 29-23 2964 0-45 12 19 3 8 31 8 72 34 .50-46 12 29-87 29-05 29- 4 f; 0-63 25 5 2 5 11 17m 67 30 52-00 10 30-25 29-77 30-0<- 0-38 25 6 13 6 17 4 54 26 42-10 11 30-41 29-03 29-89 0-77 18 12 12 2 6 2? 53 33 40-12 IS 30-00 28.25 29-45 0-90 17 234 14 1 6 79 23 197 15 48.78| 29-74 131 jiso 165 ANNUAL Met ecology. 2^9 ANNUAL RESULTS. THtRMOMET£U. WlND*; Highest Observation, July 27th 78°S. Lowest Observation, Janxiary 2-2d - - - - 17«N. Greatest Variation, in twenty-rfour hours, June \st''2d . - - - 18* Annual Mean .-.------------- 48-78 Barometer. Wind. Highest Observation, June 25th --- f5045NE!; Lowest Observation, December 17ih --.----- 28'25W. Greatest Variation in twenty-four hours, January SOth-Slst - 1-13 Annual Mean 29-74 Rain. Inches. Greatest Quantity in August - - - - 4*50 Smallest ditto in October . - - - - .31 Total Quantity for the Year . - - - 23-01 Weathtcr. Days. Wind. Times. Fair - - 2fJ4 - - N. & NE. - 130 Wet - - 131 - . E. &SE. - 79 S.&SW. - 197 365 W. & NW . 165 571 REMARKS.—On the 22d of January, the Thermometer, within two miles of Nottingham, stood at 14°. April 19th, Snow had fallen to the depth of one foot. May 2d, Snow fell this morning. August 6th, the Rain that fell from 9 A.M. to 5 P.M. amounted to 1 -72. Loud peals of thunder at noon, increased at 4 P.M., when the lightning became extremely vivid— the thun- der tremendous— the rain descending in torrents, and continuing so most part of the night. December I7th, the Barometer at U P.M. stood at 28-L)5f. "^rhe following are comparative observations on the fall of the mercury:*— Barometer. Kesivick. Kendal. January 1788 - - 28-35 - - 28-38 Januarvl789 - - 28-09 *• - 28-12 December 1809 London. - 28-89 - 28-58 Nottingham, 28-21 N. B. I'he Barometer is firmly fixed to a stand^trd wall, over a stair-case, i-a level of 130 feet above the sea. The Pluviameter is placed in a earden. ona level of 130 feet above tne sea. on an elevation of 140 feet from the level of the sea. Quantitij of Rain in 1S08, at the following Places in- Scotland: BolhivelL Gordon 1803. Dalkeith. Cast{e. Glasgow. Castle. Larps. Inches. Inches. Incht'S. Inches. Inches. January - - 1.29 1-278 1-246 1-27 February - 1-905 1-461 -778 1-62 March . - -452 1-26 •082 •71 April .- 2-805 1-923 1-535 2-97 May - - - 2-22 1-887 1-371 •78 June - - - 2f288 1-579 1-814 1-62 July - - - 4*12 1-83 31 18 2-91 August - - 3-451 5-827 5-597 2-92 September - 2f65l '655 •616 5-31 1-452 October - - 2-393 3-8i8 2-171 3-21 8-033 November - 1-48 '1-993 2-135 1-68 3-664 December - 2-44 1-507 1-342 £•21 5-488 27-995 24-598 21-795 27-21 18-637 Meteorological •40 * Meteorology. METEOROLOGICAL TABLE, Bv Mr. Carey, of the Strand, For March 1810. Thermometer. Height of the Barom. Inches. DegreesofDry- ness by Leslie's Hygrometer. Days of the Month. P o Z h Weather, Feb. 26 .38 47° 47° 29-89 23 l-air 97 47 53 44 ^65 19 Cloudy 28 40 52 48 •99 32 Fair March 1 47 53 47 •78 16 Cloudy 2 48 54 49 •69 10 Small rain 3 49 51 41 •55 0 Rain 4 41 50 40 *SQ 18 Cloudy 5 40 45 39 •16 19 Cloudy 6 35 38 41 28-95 0 Snow 7 40 45 42 •81 0 Hain 8 45 49 46 •99 15 Cloudy 9 52 54 49 29*28 10 Stormy 10 50 54 50 •76 36 Fair 11 50 54 50 •90 30 Cloudy ^ 12 52 52 46 "J5 10 Stormy 13 40 42 40 30-00 32 Cloudy 14 39 41 38 30-00 25 Cloudy 15 38 38 35 29-64 20 Cloudy 16 35 39 34 •55 10 Cloudy 17 35 40 33 •65 30 Fair 18 32 44 36 •90 22 Fair 19 29 44 43 30-00 19 Fair 20 34 50 40 29-95 33 Fair 21 35 49 41 •65 21 Cloudy 22 34 42 34 •98 19 Fair 23 32 49 36 •72 34 Fair 24 33 47 37 •72 2f Fair 25 32 42 37 •81 25 Fair 26 35 42 39 •85 27 Fair >J. B. The Barometer's height is taken at one o'clock. [ *4l ] XLt. On the Torpldihj of AnhriQls. By Benjamin Smith Barton, of Philadelphia, M.D, To Mr. Tilloch. Sfr, 1 LATELY purchased, and have just finished the read- ing ut, *' An Kssav on the Torpidity of vVninials, by Henry Keeve, M.D." The work has a Horded nie much amuse- ment, and some instruction ; and may, doubtless, be read with greai satisfaction and advantage by the yoimoer das* of nat\iralists. It is, however, I think, kss replete with new facts and experiments, and with original and enlarged views of the nature and phtenomcna of torpid, life,, that! might have been expected, considering the respectable au-^ thor's opportunities of acquiring information, and the length ot tinie that he has had the subject under his con- sideration. *- j imIj iiiiiJoijp -(^i •;!. 'ioi 'aJii'J Having myself, for several years^ bieii e^n gaged. vm)irfi fjuiries relative to the same subject, in various classes •♦ An Essay, &c. section ii. pages 39, 40. f Fragments of the Natural History of PennsylvaiJa,- Part First. Ap- |»«ndix L pages IS and 19. Philadelphia, 1799. ( fragmeius, &c. Appendix I. page 18, persons. On the ToTp Idity of Mm alt* 240 fjtrsons, that wh6le flocks of the Carolina parrot, or para- Keet, (psittacus caroUitensiSf) continue in a torpid state, in the hollows of trees, in the state of North Carolina, and in some other parts of the American Union. I believe en- tire dependence may i^ plated upon this slatement ; though it would not be difficult to show, that these birds arc often seen abroad, and pretty active, when the ground is whitened by snow. I could mention not a few other birds, the torpid state of which has been spoken of by na- turalists and others ; and these birds I shall mention Iti my ^' Facts, Experiments, and Observations, relative to the Torpidity of Animals." But " what" (says Dr. Reeve) " is the eviderice in fa- vour of so strange and monstrous a supposition ? Nothing but the most vague testimonies, and histories repugnant to reason and experience.'' This, surely, is not the proper language to be employed in the investigation and discussion of physiological ques- tions. Authorities are facts in natural, as well as in civil, history. And in favour of the torpidity of some of the birds which [ have mentioned, the authorities are, some^ times at least, highly respectable: nor are they few in number. Tn regard to the swallows, I shall say but little ai present. I have, at this time, in the press, a memoir on the migration and torpidity" of these birds. I am confident that I shall be able to convince every candid philosopher, that great numbers of swallows, of different species, do occasionally pass into a state of torpidity, more or less pro- found, not merely " in some remote quarter of America,'** but in the vicinity of our capital cities, where there are Some men of genuine observation and inquiry, and who are as little prepense to believe the marvellous in natural history, as any philosophers elsewhere. I do not suppose, that all the swallows of North Ame- rica become torpid. It is my present opinion, and it was my opinion when I published the " Fragments" in 1799> that the swallows, in general^ are migratory birds*. But subsequent and very extensive inquiries have conviticcd me, that the instances of torpid swallows are much more frequent than I formerly supposed they were ; and that there are two species of the genus Hirundo, which are pe- culiarly disposed to pass the brumal season in the cavities of rocks, in the Uollo\vs of trees,. and in other similar sittir * See Fragments, &c. Appendix I. page 16. See, a^so, Introduction to thi« \York, [)ag€»^,^^ xiii, § xxiv, xxv, xxvi. .S:L:ii'.i Qa ationi. C944 On the Torpidity of An m ah. arioiis, where tTiev have often been found in a soporose state. These species are the hhiuirlo ripnria^ or sand- swallow, commonly called, in the United States, hank- svvallovi^ and Ixnik^ martin ; and the Ivruvdo pela^gia^ or aculeattd svNallow, which we call cliirnncy-bird and chim- ney-swallow. /There is no fact in ornithology leifer esta- JiHshedy than the fact of' the occasional torpidity of these two species of Hirundo. ■' I sav hot;hing of the torpiditv of swallows ** under water.** But I do not wholly deny this fact. And I take much «pkaslirc in referring Dr. Reeve to a short paper, in the Transactions of the American Philosophical Society, vol. vi. parti.,' relative to the discovery of a torpid swallow under a qijarnity of mud and leaves. The author of that paper was ai most'. worthy and respectable man; and a man so religiously attached to truth, that I heheve him to ha\^e been Incapable of tutering a falsehood; He was, n)oreover, a man of nice observaticm, and of a philosophical turn of naind. I do not wisli to lirgc this part of the swallow's history any J fupther. I have nothing to sav in support of the ** swallow song.*' But when, in page 44, Dr. Reeve as- serts, that no swallows '*' were ever found in all the rivers and lakes of England, Wales, Ireland, Scotland, or Switz- erland, although fishermen are constantly employed on these their supposed iiiding-places," does he mean to say, that it has never been asserted by any of his countrymen, that swallows have been found torpid, under water, in_ England P Swallows are said to have been found torpid ^' in the river Thames;" and the fact seems to have been credited by some illustrious Endishmen in the 17th cen- tury; and among others, if 1 do not mistake, by the im- mortal William liarvey*. But I will take my leave of the swallows. — Since I pub- lished my Fragments, I have obtained much information re- lative to the torpidity of the humming-bird. I have hinted at this subject, and have, indeed, most pointedly admitted the fact, in my letter to Mons, la Cepede, published in your Philosophical Magazine. I am now fully persuaded, that * In Dr. Birch'-= Tlist'^ry of the Rnyal .9of?>/y, vol. iv., there are some cu- rious notices about swallows. The foliovvin.(» mav not be deemed wholly unworthy of Dr. Rce\ e's att«jntion. " Sir John Hoskyns proposed, that h n'^ight be duly examined, what becomes of the swallows, :>.nd in what state they are during the winter. In answer to which Mr. Henshaw affirmed, that the chancellor of Deumnrk told him, as an undoubted truth, that in Iceland, there had been taken out of the ice swallows, which being afler- ward»"brought into a warm stove- recovered and flew about the room." — Mr. Henihaw observed, " that he hud nn account like the former concerning •walloVfs froiu our waternicu, via. cliat they have found them in the river Thames ; . 0?i tMTorpldUy ofA/iimdls, 04 5 that instances of the torpidity of the trochilui arc by.no me^ns uncommon in the United Slates : and I regret i\^y ^laving treated with so httle respect, the upinion of tk^ Conneciicut gentleman already aliuded to. It "is certain^ at least, that the trochilus, hkc the generality of the SA\ial- Jows, >is very impatient of cold; and that it sometimes, even in our houses, very suddenly passes into a profound slumber, from which, however, it awake*, to enjoy all the j)rivileges of its life. — I say this is certain. And this, so far as his sentiments may be collected from his Essay, is more than Dr. Reeve is willing to admit of a//y species in ^ the great class of Birds. The fact of the torpidity of the trockilus was not un- known above two centuries ago. It is related by the Spanish historians Herrera, Ximtnes, and bcveral others, though it must be confessed tbat these vvriters have mixed witn the truth, souin Jable. I have lately conversed with an intelligent genileman, who was born, and has long re- sided, in the kingdom of Mexico. He assures me, that the fact of the torpidity of the trochihis is known to every one in that country, and in the adjacent provinces, ll^i added, that he had himself seen one of these little birds in its brun;al sleep, m a tree. — ! shall discuss this subject at length, and shall illustrate it by actual experiments, in my work on the torpid state of animals, to whith I have al- ready alluded. In the mean while, I flatter myself that the following lines, a part of which imrnediately relates to the somnus of the trockilus, will not be wholly unaccepta- ble to some of your readers. The author is Raphael Laii- divar, a native of Guaiimala; and his poem, entitled Rusti- caiio MexiQarta, in fifteen books, besides an Appendix, in verse also, deserves to be nmch belter known than it ap- pears to be. It is, indeed, well worthy of an English trans- lation; and I sincerely wish that the elegant JMr. Sothebv, whose translation of the Georgics ot V'lrgil has so deserv- edly procured him a high reputation,, could bejinduced tp Tliames; and that towards the end of the ycnr they aseemble in jrreat num- bers on the little UUutls of the river, and then submerge theaiselvts in ll»e water." — " Upon reading the minutes of the last meeting, ^.r. Henshaw remarked, that Dr. Harvey h:Aci considered the state of swallows in the win:er, and had di.'^.'.ecied some of them, which Irad Jjecii found under water, and could not observe that there waseither waruiih or motion in them."— ♦♦ Mr. Chefwynd, of Inj^stree, being present (at a meeting of the Royal Society), obierved, that daring I'he time that the swallows are laid up fcir the winter, tliey moidt, and return in the spring with all new teatiiers." 'J'he History of the Royal Socifty of London, &c. &c. By Thomas Birch, J).D. Secretary to the K:n •jj Society, vol.iv. pajjes 5;3:J, 534. 5i\7. Q 3 undertake 54(1 (hi the Torpidity ofAnhnals, undertake the task. My copy of LancUvar's work, whicfi is, I believe, a very rare one, would be ;n his service. The public pulse might be tried, by the publication of a version of one or two of the books. In his 13th book the author treats of Birds. And here it is that he speaks of the humming-bird, its manners, iis^ sleep. See. '^ Nil tamen exiguo novit praestantius orbi.s CoUhrio dulcis spoliato niur'mure vocis*, Sed claro tenues penna radiante per artus. Exiguum cqrpus, forsan non pollice majus, (Ouod rostro natura parens munivit acuto Atque artus ferme totos eequante vokicris.) Induit aurato viridantes 1 amine plumas, Et varios miscet tractos a sole colores. lUe volat rapidum Zephyriim supcrante volatu, Et raucum penna tollit stridentc susurrum. Eoscida si vero fragranti educere flore Mella velit rostro, viresque reducere membris, (Ouippe alia quacumque negat se pascere mensii) Sistitur in medio concussis acire pennis, Neetareum donee tercti trahat ore liquorem. Ast adeo promple subtiles concutit alas, Ut vigilcs fugiant oculos, ludantque citata; ; Suspensamque putes volucrem super setherafilo. Sin autem sylvis borealis bruma propinquet, Plusque vagus solito frigescat Jupiter imbrc, Frigida prascipiti linquit Colibrius arva Nostra fuga, linquitque levi viridaria penna, Et longum niontis nigris absconditus umbris Indulget placido, ceu Progne arguta, sopori, Dum luces Aries stellatis noctibus tequet, Yerque novum pratis antiquum reddat hororem.*' Rusticatio Mcxicaaa, lib. xiii. v. 217 — 242. All this. Dr. Reeve will perhaps say, may do very well in poetry : but somethint> more positive on the subject of the " placidus sopor" of the colibri is required. Some facts, and therefore something more positive, [ have already mentioned: and many additional facts, wiih experiments, I promise to give in another place. At present I will only add, that Mr. Landivar mentions the torpidity of the humming-bird, not as a fable, but as an established truth. For in the short Moniium prefixed to }iis interesting work, * « Avicula hrtc Colihri in America Merldionali, in Scptcntrloxiali vero Qhtpa-viirio;y, intended to facilitate the practical Analysii Q,i Mincrab," by ¥. Accuui, ^d edit, page :iij. with. fof collecting and transferring Gases, f 45 V/Ub the utility of the instrumems before named, to render any further observations concerning them necessary. ,4t is in consequence of such reflections, and the invita- tions I have received from others, whose judgement I re- spect, that I take the freedom to lay before the public the annexed sketch of a pneumatic table, which in the routine ot niy profession I have found extremely useful in operating on ^ases, which I flatter myself will be found aaacquisitioa among the apparatus to the laboratoty. Tlie discovery of the gases, and their great importance In the researches of modern chemistry, have occasioned, as is well known, the necessity of some peculiar instruments, by means of which these bodies may be caught, collected, transferred, and. submitted to the action of other bodies, Aniong these _the very simple aad ingenious reservoir, in- vented by Dr. Priestley, and named by him the pneumatic trough, is the most intlispensable. Several alterations have been proposed in the structure of this vessel, to reader it more. convenient for use ; but these, it may be said, relate either to its form only, or to its !\eatness and general ap- pearance,and not to its principles, or application and utility,^ as connected with the operations of pneumatic chemistry. Fig. I. (Plate VII.) represents a wooden table three feet six inches high, two feet ten inches long, and one toot eight inches broad. At each end of this table, and at a depth of ten inches from its upper edge, is a moveable board or platform d d measuring 18 inches by IC^. These platforms are supported horizontally by swing-brackets e e, which may be turned aside to allow the platforms d d to fall down between the inner sides of the legs of the table. The brackets e e are then concealed from view. The platforms d d serve to support table furnaces, retorts, and stands,, or other apparatus employed in the production of gases. Fia:. 2. is i^w ceconomical lamp furnace with its retort in action, to show the use of the platforms. The upper part of the pneumatic table is siuTounded by a broad rim or border xx two inches and a half deep, ^o as to form a shallow tray. It is of rather larger dimensions than the table, projecting over the frame of it about three fourths of an u^h. This tray (as 1 shall call it) is divided into two unequal compartments, namely, a cistern a a occupying one end or side, and a stage or shallow plain b occupy mg the other. The cistern a a is 16 inches deep, J 9 wide, and 16 broad ; the stage or plain b occupies the l'em;iining part of the tray b. When the table is intended to be fSa Description of a Hydro-pneumatic Table, be used, the X.T^.y x x x^ together with its cistern a (7, and stage or plain ^, is to be filled with water, so as to stand at least three fourths of an inch deep over the shallow plain or stage b in every direction. Across the cistcrii fl a is a shelf, marked c in the drawing; it is five inchei? broad, and perfectly level with the stage b. This shelf slides backwards and forwards horizontally within the cistern a, so that it may be placed at any convenient di- stance from the lamp furnace, fig. 2, or other vessel from which gas proctcd^. It is provided on its foremost edge with a row of holes, into which from underneath, broad short-necked funnels are fixed ; it serves to sup- port the receivers standing on the shelf r, with their open ends turned downwards upon the before-mentioned holes, through which afterwards the gas conveyed by the funnels is made to pass into the jars de3tined to receive it. As this shelf is level with the stage, and may, by its sliding motion, be brought close to the stage b where it terminates in the cistern, the jars placed upon this shelf, when filled with gas, may be slided along without further trouble to a distant part on the adjoining plain b, whilst other vessels previously filled with water in the cistern a a, and standing also on the plain b, may in return instantly be itioved on the shelf c ; and thus the trouble of removing the jars into and out of the cistern is totally av^oided. From this statement it will be seen that the advantages of the pneumatic table are considerable. It enables the operator to fill jars or vessels with the utmost neatness, convenience and expedition. The necessity of trans-, ferring them when iilled with gas, olit of the trough; is avoided, and the danger of suffering part of the gas to escape, as well as the almost unavoidable spilling of \V'ater whilst the vessels are removed, is completely guarded against. It enables the operator also to fill jars of almost any size, which cannot be done in the common trough,- without rendering ft unwieldy and very cumbersome, oi* without being at least obliged to immerse the jars pre- viously into a deeper troligh, and thence conveying them upon a plate or saucer into the reservoir in which the^ are to be filled with gas. Thus the constant danger of having either too much water, so as to overflow the trough, or loo little, so as to admit common air to enter into the jars when the water sinks belovv the ^helf, is effec- tually remedied. In thl* common trough the vessels are also exceedingly liable tO' be overset by the prcsi^ure of th^ waterji On Salmon-Pry, 951 water, the height of which rapidly increases when large jars are filled, and require continual removing. When large quantities of gases are required, as in public lectures, this^ pneumatic table has been found exceedingly useful , 'I'he operator not being restrained for room in the jqnanagement of his experiments, nor being obliged to trans^- fer the vessels continually in and out of the apparatus, and being enabled to perform his operations within a con- fined space and without encroaching upon any surroundittg furniture, are likewise no small advantiiges, which entitle it to the attention of those who have no access to the la- boratory of the operative chemist. 7'he shelf yy* is very ferviceable as a receptacle for holding whatever utensils may be deemed necessary to be near at hand during the experiment. Compton Stree>j Soho, March 12, 1810. FREDRICK AcCUM. XLIfl. On Salmnn-Fry : in Jmiuer to a Correspondent whose Communication appeared in our last Number, By JojHN Carr, E,sq.^ of Manchester*, To Mr. Tilloch. /Sir, a liberal discussion of subjects in British natural history certainly affords a very amusing variety amongst the (more abstruse branches of scientific research, which obtain so deserved a preference in your select journal ; and it is with this view that I submit my present observations, rather than from a wish to attain any triumph over the brief and illusory remarks on Salmon-leaps, in your Maga- zine for last month. What I formerly stated, and shall now offer, is the result of my own personal observations in the Tweed, Coquet, Tyne, Eden, Esk, and several other northern rivers which swarm with salmon, and I mention this only as increasing the responsibility for what I shall advance. Were it really a fact, as contended for by the writer I am opposing, that salmon-fry actually continue upwards of twelve njonths in the same river where they are spawned j then during the summer njonths, (when the streams ar(; * Mr. Carr 15 respectfully informed that, if we have not misunderstood his allusion, he is mistaken respecting t^he author of the paper to which he has sent this as an ans-Acr. We have therefore suppresspd his introductory parnj;Yaph.— EiUT. f52 On Salmon- Fry. half dried up, and the water transparent,) however dlniinn- tive might be their size, vSuch are their nicredlble mukitudes that they could no more rqniain concealed than the pebbles over which the streams flaw ; and yet daring ihis season, so favourable to exposure and discovery, I believe not one solitary individual of the preceding spawning season can be met with. In the Tweed, more than two hundred thousand salmon are annually caught ; and ihe^e, astonishing as the number may seem, probiibly bear but a moderate proportion to the whole quantity that enters the river. Every female de-. pcisiis many thousands of ova; hence it is obvious w])at myriads of progeny niust be the result; and accordingly in the months of March and April the amount of fry in the river fully corresponds with these data; but after the vernal floods, no vestige remain^ of the true salmon-fry, the whole of the immense body being swept down into the ocean. The writer in your last Number seems to he unacquainted with the spawning months, which are not the two which he conceives, but the last four months of the year. The fibh by no means all spawn at or near ihe same time, there being conside'rable diversity in that respect, some com- mencing and even finishing two or three months before others. This diversity probably has two very dift'crent cir- cumstances for its cause, — the dificrent ages of the fish, and the different periods of their entrance into the fresh waters. The weather, and state of the rivers as to floods, have also an evident influence. It is in the months of June and July that the old fish, recovered from the great expenditure of health and substance in the preceding spawning season, first begin to ascend the rivers. What are called fresh fish, indeed, conie into the rivers even in December, and in all the following months, but these are fish which have not spawned in the last season. In' Sep- tember the females are all "exceedingly distended with ova, and a few of them even begin spawning in that month, more in that following, but .November and December are the princi[)al spawnnijx montiis; and tliat the ova then de- posited are the germs of the same fry which ap})ear so abundantly in the. spring, is a truth as well known, and ascertained, as that the fish themselves have heads and tails. The very rapid growth of the fry i specially noticed, as an extraordinary circumstance ; 1)ut we shall advance a very' short way indeed intt) natural research, if the character of e;t/J»ordinary is to beat us back. The average weight of th«- On Salmon- Fnj> ^ , 255 Ihe fry In spring will not amount to btie ounce ; and th^ writer who has made it necessary for nie to offer these ob- servations, admits that the spring Fry in the following July and August attain a weight of from M to 20 ounces. This latter fact I know to be much greater than stated ; and surely the writer who can cavil at the acquisition of the first ounce, and imrriediately admit its multiple by twenty in h'ttle more than the same period, must have very incon- gruous notions on the subject. His paper was professedly" written to exhibit what he calls a more rational and cre- dible account of the matter than I had given ; and its owrt contradiction and improbability are strikingly manifest, as will be seen by contrast ng the following two passages: *'The fact is. tl^ie young fry do not descend the rivers with the old salmon in the spring after they are spawned, for in 'the October following they are no bigger liian a min- now.'*— '' In the months of June and July they (the fry) are about five oi-'slk inches in length : I his I know to be fact." ^ .-;••-■.:. • . • These paragraphs contain the bonis of a piercing dilem-^ ma, and I ofi'er the writer his choice of being gored with that which he may prefer. Either the same fry which were five and six inches long in June and July have, hy some strange means, been wasted down to the size of a minnow in the following October, or the fry then no bioirer "than a minnow continue in the river till the following June and July : and in this latter case, whence have those shoals of fry originated which the same writer sends down to the sea in spring ? The fish which he speaks of in the months of June and July, is an abundant and well-known visitor in our rivers at that season ; but it is a perfectly distinct species of tself, and by no n^eans the salinon-fry, with which, however, it has long been, and with the ill-intornied it still is, con- founded. It is the samlet. Few animated productions of nature have had a more contested, origin, or been subjected to more wild and extravagant assumptions. Most e:enerally it was considered as a backward and spurious brood of the salmon, that always remained dw^rf ; never bred j and even all the individuals wer^ absurdly deemed males. Its na- tural history is now, however, well ascertained, and, ex- cepting in size, it certainly does approximate, in all re- spects, very nearly to the salmon. Likfe the latter, it ascends our rivers, from the ocean, in sunmier, continues in great al)undance throusih the autunin, .afterwards spawns, and in the fir^t two months of the year again descend^ to the iea. t54 tn Saimon-Prt/. sea. It probably never exceeds nine, but averages only stjjf inches in length. Though every tvhere the same precise epccies, its dubiou:? history has assigned it a number of provincial nan)es. In Scotland they are called par^, iri CuniberUnd bremliusi in Northumberland Wrack-riders (Irpni their lying on the wrack or river ueed), in the Se* :Vf rn ^o?n$OHSf and in the Wye .skir lings Or lasprings, Mr. Pennant, whose industrious research after iatts has fo seldom been equalled, in cond)ating the notion oi" their being Sfihnon-fry makes the following observations : '* The samlet is the least of the trout kind. It is by several \w?t^ gined to be the fry of the salmon : but our reasons for dis- senting from that opinion are thege. First, it is well knowfi that the salmon-fry never continue in fresh water t'tie whole- year : but, as nnmerous as they appear on their first escape' from the spawn, all vanish on the first vernal flood that happens, which sweeps them into the sea, and scarce leaves one behind. Secondly, the growth of the salmon-fry is so quick and so considerable as suddenly to exceed the bulk of the largest samlet: for example, the fry that have quitted the fresh water, in the spring, not larger than gudgeons^ return into it again a foot or more in length. Thirdly, the i^almon attain a considerable bulk before they begin to breed: the samlets, on the contrary, are found, male and female (distinguished by the milt and roe), of their com- 5non si?e. Fourthly, they are found in the fresh waters in #il tinpes of the year." These observations! of Mr, Pennant I can fully confirm from my own experience, excepting the last, which I must directly contradict ; for I believe it would be absolutely im- possible to find a single sanjlet in any of our rivers in the months of March and April, the very period when the waters are teeming with the proper salmon-fry. This little ititeresiing fish, the samlet, in natural habitudes, figure, and even oily fatness, is truly a salmqn in miniature; but, never>- theless, it does contain several discriminative marks, — in so much that were a samlet and salmon- fry, of equal size^ placed toi;ether, the most cursory eye would readily recog- nise a difierence. The samlet is thicker and fuller made than the fry, so much so as to be one third heavier in equal lengths : but what would instantly distinguish the one from the other, are several broad light blue bars crossing the jiides from the gills to the tail. These the samlet never is without, nor does (.he fry ever possess them, though similar i)juemaiks may often be seen on small trout. The back and iiniof the fry are also more dusky, and the few red spots On Salmon- Fry, ^$^ spots along the lateral lines far more dull and obscure than in the samlet. The latter are of all fish one of the easiest prey to the angle. They arc incessantly on the feed ; and an expert angler with artificial flies, in some of our rivers, will take eight or ten dozen in a few hours. Besides the salmon and samlet, the bulltrout, seatrout, and whitling, all very distinct species of the same genus, also quit the ocean and ascend our rivers, to spawn, ii^ great numbers, and their fry are frequently mistaken, by incautious observers, for the true salmon-fry ; from which, however, they exhibit several specific differences. I shall now drop the subject, having, I presume, suffi- ciently shown that my former account of the salmon was strictly correct. Even the writer who has dravyu from me the present remarks, will, I trust, by this lime have dis- covered hov/ much more easy it is to derange and embar- rass thum to elucidate an obscure case. It is worth observing, that the papers on the breeding of fish, published in the Philosophical Magazine for October and November, very sati«factoriiy illustrate an obscure fact in the natural history of the trout. It is well and very generally known, that trout, when confined in ponds and lakes, attain a size very far beyond what they ever arrive at in rivers and brooks, and that in these confined situations they never breed. This is well accounted for by the proof that they can only spawn in a swift-running current on gravel, and that there only the spawn will attain anima- tion : and doubtless the fish not being exhausted with breed- ing, in situations where no sufficient currents exist, is a principal cause of their extraordinary growth. These con- siderations are very encouraging for stocking large pools \yith trout-fry procured in the easy way pointed out in the papers I have alluded to, and by which trout of a very su- perior size may be obtained. A most sino'ular anomaly in the history of British fishes has lately occurred, by a very splendid and meritorious work, under that title, having issued from the press, wherein two species of our most abundant and interesting fish, the salmon and common eel, are purposely disregarded, under the inadequate excuse of making room for a few scarce, obscure, and immaterial species. My own cursory remark* on the two proscribed species will sufficiently establish, that, to an industrious and intelligent inquirer, they yet offer much of new and interesting matter. The most, I was about to say the only, valuable portions oF natural hi.9tory consist in a kuowlcdge of the singular and various habi- tudes- S50 Origin of the Gypsum Strata tudes and prculiar modes of existence in each distinct class, — a sort of animal biography, vvherein the species i* personified in the diversified details of ihe individual : nm\ applying this to the case under consideration, surely the animals which almost daily appear upon our tables hkv^ a paramount claim to our consideration, 6\er those which can never extend beyond administering to, certainly a laudable but yet, a mere curiosity. 1 am, sir. Your most obedient lunnble servant, Pi-incess Street, Manchester, JoHN CaRB April 6,1810. XLIV^. On the supposed Fresh-wafer Origin of the Gypsurri Strata in the b^nvirons of Paris ; on the Geological Cha- racters and Relations of tJie Alnm Shales on the Northern Coasts of Yorkshire: and on the Orbicular Blocks of Sicnite on .Mount- Sorrel Hilly in Leicestei'shife, B^ Mr, John Fare7. To Mr, Tilloch, Sir, It has given mc great pleasure to find, that the doiibt^ which I ventured to express in pages 134 and 139 of your Philosophical and Geological Magazine, as to the accuracy uf Messrs. Cuvier and Brogniart's opinions, on \h^ fresh- water origin of the lower part of tlie series of strata de- scribed in the IV^th article of their memoir on the basin of Paris*, are in the way of being cleared np, by the researches of Messrs. Dcsmarets, the elder and younger, and M. Pre- vost, who have found numerous sea-shells \n the third or lowest gypsum mass, notwithstanding M. Cuvier and his associate had said (page bO of your transla:tion) '^ we are not acquainted with any fossil.in this mass, which is the third of the quarries ;** what therefore must become of the opinion of M. Lamanon, adopted by them and others, as to the gypsums of Montmartre and the other hillocks of the basin of Paris, having been crystallized in fresh- water lakes ? or, thought of the unphilosophical expression used on the oc- casion, that one fresh- water shell therein, was *' sufficient to demonstrate the truth of the opinion of M. Lamanon ?" In a calcareous niarl, below what is called the little plaster bed in this mass, the fossils appear numerous, and are, ampullariac, calyptrce, cerites, citheres, cockles, corbufaD, crab's shells and claws, echini spatangus|, glosopetrte, * Pajjc -19 of tfec present volume. f At Gri^uou lime quarricj ;p. 1 13) our authors observc-U ccbini cypeastra. uiuriceSj i?i the Envh'ons of' Paris. 257 niurices, solens, tellinae, turritellae, vertebrae of fish, vo- lutes, &c. Below the above, three small beds oF plaster and some strata oF marie occur, without shells ; and lower, a bed ot" calcareous marie, in ilie midst of which is a plaster or gypsum bed, which contains cerites of the genera petri- colum and terebrale; many of which sea shells are per- fectly similar to those in coarse limestone at Grignon, and other places, not only in made? here, lying between beds of gypsum, but in the gvpsum itselF, although several na- turalists have {]ue3tioned the reality of such an occurrence. The above particulars I have learnt, from a notice in Mr. Nicholson's Journal of the present month, which contains other interesting particulars. Should M. Desmarets and Prevost have presented any memoir on the above subject, you will not, I hope, fail to translate it at length, on its reaching this country. In the respectable journal above mentioned, Mr. Richard Winter has given an interesting account of the manufacture o^ alum in ihe neighbourhood of Whitby, and of the strata whence the raw material or alum -shale for making this useful article is procured ; of which geological particulars I beg to present a brief sketch, for the purpose of soliciting further information, through the medium of your Magazine, such that may enable us to fix the place of these strata in the British series. Alum-shale, a blueish gray argillaceous schistus, occupies the coast of Yorkshire for about ten miles southward, and 18 miles northward of the town of Whitby, and extends inland a great distance ; cliffs of this shale appear on the shore which are from 100 to 750 feet high, and on which the sea is continuing to make its inroads. A ferruginous sand-stone (perhaps the same with that of Woburn), iron- stone, and shale, or clay ot its decomposition, covers the alum-shale stratum, having an easy dip to the southwest. T!)e sand-stone appears from 4 to 50 or more yards thick, producmg ochrey springs at its bottom ; it hardens by ex- posure in buildings : a thin bad scam of coal or jet, (pro- bably bituminized wood,) seldom exceeding tuo inches in thickness, is sometimes found under or in the lower part of the sand-stone: the slines or length-way joints of the strata of stone and shale range N. and S., and the end or cross joints E. and VV. The alum shale contains several species of ammoniice, abundance o\ belemnitce, hones of animals, iiautHi of two or three species, shelU of various kinds, trochit(^^ and veriebrce of fishes or animals. It likewise holds nodules of Vol. 35. No. 144. April 1810. R indurated 2.5 i On Alum' Shales incUiratccI clay, which contain native alum; geodes of iron- stone that contain vaplulia ; pieces of petrified, charred and bituminated ivoody ox jet : red iron-stone, in strata of a few- inches to two tcct thick, four or five in number, at about 200 feet from the top ot" the shale: calcareous spar, about half an inch thick, in the vertical slincs and end-joints of the shale above mentioned : whin-dykes arc said also to traverse these strata, and to have charred the coals in their vicinity? The specific gravity of the alum-shale is about 2*48 ; it decomposes into clay on long exposure : its upper part is richest in sulphur, and produces about oiic ton of alum from 130 tons of shale, or 00*77 percent.: the lower part of the shale is very bituminous, hard and slaty ; a spontaneous and slow combustion ensues when the alum-shale is mixed and sprinkled with sea-water. Such arc the interesting geological facts, which Mr. Winter has laid before the public, respecting the aluminous shale strata of Whitby ; concerning which, it is further desirable to know, the names of the different species of im- bedded shells and other organic remains, with reference to published descriptions and plates of them, or drawings and descriptions of such as have not yet been described by na- turalists ; and an account of the strata that underlay the alum-shale, as well as of those which overlay the ferru- ginous sand-stone. To ascertain these last particulars, it may be necessary to examine the extremities of the alum- shale on the sea- shore, and to trace its edges or boundaries for some miles inland ; carefully distinguishing between the alluviaL matters, properly so called, consisting of or containing rounded stones and broken and heterogeneous mechanical mixtures, and the regular stratified matters, which will somewhere be found in a regular range, covering the ferruginous rock and other strata which Mr. Winter has described ; the nature and peculiar fossils of which strata, it will be very desirable to obtain an account of. In Derbyshire, some arc of opinion, that the great or limestone Shale which there covers the mineral limestone and basaltic strata, as shown in Plate if of your thirty-first volume"^, (and of Vvhich Mam Tor is composed,) is the same soil or assemblage of strata, which produces alum at * And is de^^rlbed by Mr. Whitehurst in his "Inquiry conccMiing the £arth," iid edit. p. 18:5; v^here however he is wroii^ in saying, that thissJialc contains no vegetable imprcsbioiis, since such occur at Shaw-Engine mine there mentioned, and numerous other places. Mr. Mawc, in his '* Minera- Jogy of Derbyshire," p. i!-3, has copied this error, and added a still greater oce, vi2. tbat litis shale " is not stratiiicd." Whiiby in Yorkshire, ^c. 259 Wiiilby and the adjacent parts of Yorkshire; and at Shavv Engine mme in pariicular, near Eyam N. (where this stra* turn has been penetrated 360 feet deep to come at the vein of lead ore in the first limestone) alum is said to form a crust on the parts of the shale exposed. T cannot however consider this shale, and that at VVhitby, as belonging to the same soil, but believe the latter to correspond with the great or clunch Clay of Bedfordshire, Cambridgeshire, Lin- colnshire, &c., underlaying the Woburn Sand and fer- ruginous sand-stone strata, as hinted above: which clay abounds with selcnilc and pyrites, and at its exit from the island on the south coast in Dorsetshire, if 1 mistake not, takes fire on contact with the sea-water, as at Whitby ; and whose highly bitutninous shales, towards its lower part, have occasioned the useless expenditure of such immense a»ums of money ni search of coals in this and past ages, in all its course through the English counties. At the east end of BoJinbroke town in Lincolnshire, in 1607, 1 observed these- bituminous shale beds, and within a few miles, an expensive boring was at that time making, in search of coal-seams, which existed only in the ideas of the adventurer. Ludi Hel- montii of various sizes and shapes, some long and cylindrical in shape, (of which sir Joseph Banks has specimens at his seatatUevesby) with thin shells investing them, which seem to prove their animal origin, are found at Bolinbroke, and elsewhere : Quere, — Are ludi found in the Whitby shales? or large anomia gryphus, perforated, or worm-eaten as it is called, near to the sand-stone ? Mr. Winter mentions the Whitby strata, as passing into the interior of Yorkshire and into Lancashire 5 but is it not more probable, that the ancient alum-works in Lancashire and the western parts of Yorkshire, which he alludes to, were situate on the shale of Castleton Mam Tor, above mentioned ? and not on the Whitby shales ; since the former contains sulphur sufficient for the production of the sulphuric acid, necessary in the production of alum* An alphabetical list of all the places, exactly describing their situation, where alum has at any time been made in the north of England*^, which perhaps Mr. Winter by the as- sistance of his friends could furnish, would prove of con- siderable use towards deciding the geological questions above stated, as to the number and relations of the rich alu- • Benjamin Martin's Natural History of England, vol. li. p. 2^9, men- tions alum as among the mineral products of Derbysiiire ; but I found no lilrorks, Dor heard of any, in my recent cxajninsitioii of the Whitby jtrata I have never !)acl an opportunity of seeing, or any oth«r where aluin is manulacturecl ; nor do I reeollect what Mr. William Smith has ascertained, relative to the Whitby and other aluin -shales. 1 he valuable information which ^J^. Winter has already given on this subject, is, as I hope, but the prelude to further details, which would greatly oblige, Sir, your obedient servant, No. I'J, Upper Crown Street, JOHN FaREY. Westminster, April 5, 1810. P. S. The perusal of an extract in your last Number (p. 222) , respecting the orbicular blocks of granite of Talavo and Sartene, and the doubts expressed, whether the latter received their present form by the effects of attrition or de- con)position, induce me to state, that in a cursory exami- nation of Charnwood Forest in Leicestershire, in August 1S()7, previous to entering on my Derbyshire survey, I found on Mount-Sorrel common, on the north and north- west of the windmill, several isolated blocks of sienite, from one to several feet of solid content each, which ap- peared at first sight like rounded stones, almost half im- bedded in the soil ; but on a closer examination I found them to be perfectly similar in kind to other blocks nearly cubical, which were lying about on the grass, of which blocks seats are made at the doors of many of the houses in Mount- Sorrel town, which most travellers that way must have observed. Seeing reasons for referring the rounding of the blocks in question to decomposition rather than attrition, I attempted, and succeeded in two or three instances, in turning over these blocks, by which it appeared evident to me, that attrition had had no share in giving ihen> this semi-orbicular form ; the bottom in contact with the soil, presenting a perfect face of the cubical form peculiar to these blocks, and no appearance of breaking or other vio- lence : in a further search on this common, I found such a series of these blocks in all stages of their decomposition, as to leave no doubt on my mind on the subject. In the progress of my subsequent survey, 1 have found' ^ numerous instances of round masses of granite, of very different species apparently, some very large,' but none of these boulders admitted of any hesitation in referring their form to attrition, or in considering them as the alluvial ruins of very distant regions. One of these granitic boulder* I found in the Buts pasture at Ashover, on the limestone, joiiie in Breiby Park, on the red marie, some on Maccles- field On Crystallography, ^dl field common, Cheshire, on the coal-measures, some in al- luvial marie on Werneth-Low HiJl in Cheshire, (as men* tioned vol. xxxiv. p. 50,) and in vast numbers in the vale of the Goyte from Whaley-hridge downwards, and in its various branches in J)erbyshire and Cheshire: in nu- merous other places, single blocks are found. What I wish to impress on geological observers is, the necessity of stricter attention to alluvial matters, and not hastily to con- clude whether round stones are boulders, or were formed by decomposition. — J. F. XLV. On Crystallography, By M, Hauy. Translated from the last Paris Edition ofkis Traite de Mineralogie. [Continued from p. 201.] ON THE NOMENCLATURE OF MINERALS. JVJiNERALOGY and the other natural sciences have been cultivated during a long course of years, without men of science being aware of the great influence possessed by words, the signs of our ideas, in facilitating the acquisition of their ideas themselves. The language of the sciences was not submitted to any fixed rule; the caprice of the nomenclators themselves decided both the choice and the number of the words which composed each denomination; and these words, frequently improper, or even calculated to lead to a fallacious interpretation, presented the double in- convenience of injuring the operation of the meniory and of obscuring intellectual perceptions. At length Linnaeus undertook to make natural history speak a rational and methodical language, by reducing every denomination to two words, one of which should be com- mon to the species denominated, with all those which bcr longed to the same genus, and the other should serve as the distinguishing sign of this species. The example of this illustrious man has been followed by all those who have since cultivated the study of nature with most suc- cess ; and the authors of modern chemistry have adopted a similar precision in the idiom of that science, in which it is conjoined with a peculiar advantage originating from the very basis of the subject. It consists in this, that here, to name and to define are one and the same thing 5 and a mere collection of the names, such as fluate of lime, sulphate of barytcs, &c. presents an abridged treatise on the science. R 3 We tlJ? On Crystallography. We have adopted this nomenclature wherever the know- ledge we have acquired would admit of it; and amidst a crowd of examples which we could quote, in order to prove how much mineralogy has gained by this adoption, we shall confine ourselves to what is furnished by the word spar. Originally several species of minerals which had a lamellousand opal-like [chatoyavt) texture were united under this head. Thus there were calcareous spars, heavy spars, fliLor sparsy shining spare same bodies, having been better known, were separated from each other and placed in different genera, or even in different classes, and nevertheless they were not allowed to preserve their common denomination of spar; and the inevitable alter- native occurred, cither to parcel out a genus in order to disperse its members, which is contrary to all the principles of the method, or to confound under one and the same name, genera which in other respects had nothing common, which IS not less opposite to the principles of a good no- menclature. And as if there was not enough of confusion occasioned by the spars of the ancient mineralogy, the abuse of this word has, as it were, multiplied in modern denominations^ and hence we have boracic spars, adaman- tine spars, &c. The language of modern chemistry, by suppressing the word spar in the acidiferous substances, has given a kind of signal-post for extending the same reform lo some of the earthy substances which still remained ob- scured by this erroneous appellation*. As to the names of these last substances, they ought to be founded, at least for the present, on considerations foreign to the chemical nature of bodies; and it is even to be presumed that we shall not be yet able to refer them to the results of analysis, always supposing that we are not stopped by the prolixity of those which should be applied to substances composed of three or four earths intimately combined with each other. Whatever may be the case, names are wanted which could serve durinj^ an indefinite tinje, and this was one reason for also making in this part • We have preserved this word in the denominatif»n of fehhpnr onljt which has been now too generally used not to be respected, and about which there can be oo ambiguity, because it is no longer employed on any other occasion. Oh Cnjstallogrciphy, 26$ of tTic language of the science all the changes which should not produce too many inconvenicnc(:s. But in order the better to show the advantages of those which I have fixed upon, it will not He useless to explain^ before any thing else, the principles to which, in my opinion, the formation of names independent of analysis ought to be subjected. For a long time, persohs have been irt the habit of giving to mineral substances, names borrowed from those of thti places uhere they were discovered. It seems to me that this is to invert the use of these names, which ought only to serve for designating individuals or particular bodies, as, when speaking of an idiocrasis the locality of which we wish to point out, we say that it is an idiocrasis from Ve- suvius, or an idiocrasis from Siberia. If we substitute instead of idiocrasis the term vesiwiaii, which is adopted in Germany, the former expression will have the air of a j;' -onasm, and the second will appear contradictory. Others derive the new denominations from the colour nnder which the substance is presented to the first observers. . This is to transfer to the species the name of the variety. Tor example, yanoliie (violet stone) is the substance which we call axinile. But there are crystals of this substance which are green, and in this case the name of green yanolite merely expresses an imaginary substance. We ought also to avoid confounding the name of on,e mineral with that of another, with a different inflection; as when persons called hyacintliine the substance whiclv we call idiocrasis, without doubt in order to recall the ap- pearances ascribed to it in common with the hyacinth (zir- con in tliG present system), with which it had been at first united. The truth is, that it differs from it very sensibly, cither by its component principles or its structure, or everi by the angles of its crystals ; and it is sufficient to regard it for a moment in order to decide with Rome de I'lsle, that they ought to be separated from each other. So far therefore from indicating by the resemblance of the names a pretended connexion, which to good eyes does not exist, we ought rather to mark betv/een the two substances a di- stinct line of separation, by a new name which could have nothing in common with the first, and which would make ns forget, if possible, an error which mineralogists ought never to have committed. With respect to insignificant names to which several na- turalists give the preference, there is nothing to prevent their adoption. Of this number are the names derived from fable, l\ 4 SlicU 564 On CrysiallographiJ. feuch as titanium, uranium, &c. The ideas which they present are so far from carrying us to the objects which they serve to designate, that they can neither occasion mistake nor contusion; so ihat they are in the same situation as if they were purely imaginary. Sometunes also persons ascribe to a natural production ihe name of the person who discovered it ; but it would be rather too severe to condemn entirely this way of paying a kind of homage for a favour Conferred on science. It appears to me that there is more advantage in em- ploying significant words, which recall some cliaracteristic property of the mineral to be denommaied, or some cir- cumstance relative to its history. But because this mineral is frequently distinguished from others only by its general characters, we ought not to require tliat the name, which can bear upon a single character only, should make the object it ^lesignates apparent without ambiguity. Moreover, if we consider that the characters of minerals are susceptible « f variation, we must admit that the nomenclator mav here allow himself considerable latitude, and it is sufficient that each word should rest -on. some idea connected with a knowledge of the object. Without this latitude, it would be almost impossible to make significant, i. e. reasonable, names. In a subject so fraught with difficulty, every thing is admissible, except what is inexcusable. Now it must be confessed that the French language is not well adapted to furnish significant words without the help of periphrases, which exceed the narrow bounds within which true .names ought to be confined. Let this language display in the descriptions of objects the clearness and precision which characterize it; but let the specific names be furnished by the Greek, which has the eminent advantage of moulding several words into one, so as to paint in miniature the object which it serves to denominate. fn this way a multitude of words have been formed which are used in the arts and sciences. Every day ihese words are multiplied ; the in- strument which transmits ideas to a distance in the twink- ling of an eye, is the telegraph; the art of writing written words with rapidity is called stenograp/ii/, &c. Wherefore then should we banish the Greek language from the coun- try of the sciences, where it has been so long naturalized, and where every new expression introduced by necessity, finds itself as it were in the same family with a thousand others which preceded it ? It is frona the same source that I have derived the names which Ori Crystallography, S65 which I have added to the nomenclature of mineralogy. Different motives suggested their formation ; and there were two circumstances in particular, in which it was mdispen- sahle to compose new names : viz. when a species hitherto unknown was the subject of dericripiion, and when several different species had been confounded. In the latter case I generally left to one of the species the name which they nad borne in common, and I designated the rest by parti- cular denominations. 1 was almost confined to these changes ff-om absolute necessity, in the extract which formerly appeared of this treatise; and besides, I har^ allowed all the names already printed, to remain, however improper they might be. But, since, it has been observed to me that it would be proper to reform in the same manner several names which I had omitted, such as Imcite and leucolite, one of which signifies a white hody, and the other a 'white stone, smaragdi'te, which is nearly synonymous with enter aid, oisanite, andreo- lite, thallitej and some others borrowed from the localities or from the colours. These names were found vicious in a twofold degree, either from their impropriety when con- sidered in an isolated point of view, or from the monotony of their terminations when they happen to resemble each other closely. Besides all this, they were very few in num- ber, and are only found in very modern works. In a word, it was ihouiiht that the interests of science, which had deter- mined the first changes, would also suggest those which were proposed to me. I hesitated no longer from the moment I found myself supported by men of science whose reasons seemed to me to be decisive, and whose authorities alone have the weight of reasons; and I am the more anxious ihus publicly to declare the motives which actuated me, because it would give me pain to be accused of allow- ing myself to be led away by neologism. 1 certainly think there is a great difference in every respect between niaking new names and advancing new theories. The one is the result of a mere technical labour, which interferes with the dictionary of science only ; the other presupposes views which lend to aggrandize the edifice. A truth newly made known is instantly adopted, because it insinuates itself into the mind by means of persuasion. But the novelty alone of words which reach the ear for the tirst time, throws a shade of disapprobation over them : he who proposes them seems to assume an authoritative air ; they are re- jected without reflection and without examination, or they arc censured perhaps^ while at the same moment all are agreed 566 On Crystallography. agreed as to the utility oi' a change. But naturalists, tv'ho attcr long consideration undertake a task so painful, so fastidious, and so little calculated to indemnify them for their trouble, ought to have nothing but science in view, desiring no advantage but that of being useful, and dreading the reproach alone of not having done all that a true re- gard for science demands of ihem. To conclude : — Those who would siill cherish a predi- lection for the suppressed denominations, will f^nd them in the same line with those which I have substituted, and may Still continue to use them. But I hope that beginners, on comparing both nonicnclaturcs, will store their memory, ac- cordmg to my plan, with names so constructed as to en- lighten their minds. I have taken care to add to these names their etymologies, and I have done the same vviili all the rest, whether new or old, whenever ibcre was a pos- sibility of ascertaining their origin. OF THE NOMENCLATURE OF CRYSTALS. If the language of mineralogy has been so long defective, from the bad choice of specific names, the almost total de- ficiency of names with respect to the varieties of crystalli- zation has left a void, which was no less an inconvenience. There was no exception, except with respect to a small number of these varieties, the forms of which were so simple that they would suggest as if of themselves the epithets of cubical, octahedral^ dodecahedral, he, which Ought to be added to the names of the species. The more compound forms were indicated by definitions, the length of which was in some measure proportional to the number of the facets; or, if it was warited to abridge these defini- tions, by borrowing them from a resemblance between the crystal and some familiar object*, this was done with so little rationality, that it would have been desirable for the honour of the comparison if such names were less known. Convinced of the necessity of introducing the utmost precision into this part of mineralogical language, so much neglected hitherto, J have ai tempted to desiornate the va- rious crystalline forms by simple and significant names, taken from the characters of these forms, or from the pro- perties which i;esult from their structure, dnd from the laws of. decrement on which they depend. 1 shall herb present rrry readers with the series of these names, undei- the form of a methodical system. I hope that those who peruse it with attention will find an assistant for engraving * The following are exatnples of this kind : nad-hcaied calcareous spar, dog'loullud calcareous spar, ^q, the§^ On Crystallography. '^67 these nam^s on their memory, by connecting them with considerations which arc easily classified in the mind. They will perceive that, by a kind of oeconomy of language^ ' extremely useful in such eases, the same name is frequently apphcable to varieties taken in different species. It is true- that on one hand the word which serves to designate such a variety might also serve another variety of the same species. For example : I denoniinaie binary^ a form which, depends on a decrement by two ranges. Now supposing this decrement to take place on the edges, it is possible, that another variety of the same substance may be owing to a decrement vvhich takes place by two ranges on the angles. But in this case the system will present for the- latter another name borrowed from adiBercnt consideration* The inconvenience just mentioned is common to all no- menclatures, and seems unavoidable. Thus, in the language of botany, one variety will bear ihe name of crassijolia, or of rot undi folia, while another variety of the same species shares with the first the character which has served to di- stinguish it. The essential requisite is, that the method should be copious enough to furnish at least to all the known wants of science. I even expect'that, by means of the labour I have performed, a great part of the forms which "shall be discovered in future will be found to have been named bef-)rchand ; and as to those which require new names, we shall have at least a system from which to de- signate them. In all descriptions of researches, it becomes easier to go forward when the route is traced. Principles of the nomenclnitLve, — The primitive form of any given substance is alwavs designated by the word pri- mitive added to the name of the species. Examples : — primitive zircon, primitive carbonated lime, primitive sul^ pluirated lime, &c. We may consider secondary forms : — J . With respect to the modifications of the primitive form, when the faces of the latter are combined with - those which result from the laws of decrement. 2. By themselves, and as purely geometrical forms. 3. With respect to certain facets or certain ridges remarka* ble by their assortment or their positions. 4. With respect to the laws of decrements on which they depend. 5. With respect to the geometrical properties which they present, p. Finally, with respect to certain particular accidents, |-. Secondary 8(58 On Crystallography. I. Secondary forms considered with respect io the mod'ifica- t'wns which then/ present of the primitive form, TliC crystal is called, a. Pyrnniidafcd {pyramidt')^ when the primitive form being a prism, has on each of its bases a pyramid which has as many faces as the prism has panes. Example: Py- ramidatcd phosphated lime. b, Prismaied {prismc), when the primitive form being com- posed of two pyramids joined at their bases, these py- ramids are separated by a prism. Ex. Prismated zir- con, prismaled quartz. Semi'prismafed, when there is only the half of the number of riclges situated around the common base, which are intercepted by panes. Ex. Semi-prismaled S'llphated lead. f. Based {base), when, the primitive form being a rhomboid, or an assemblage of two pyramids, the summits are intercepted by facets perpendicular to the axis, and performing the function of bases. Ex. Based carbo- nated lime, based sulphur. d. Poinfed {epointe), when all the solid angles of the primitive form are intercepted by solitary facets, Ex. Pointed mesotvpe. We shjill also use the terms hi-pointed {his^porntc) y tripointcd (friepoinle), quadripointed {quadricpointe)y according as each solid angle may be intercepted by . two, three, or four facets. Ex. Tripointed analcime, quadripointed sulphurated iron. e, Margimited (emargine), when all the ridges of the pri- mitive form are each of them intercepted by a facet. Ex. Marginated garnet. We shall also use the term li-marginated, iri^ marginated, as each ridge is intercepted by two or three facets. Ex. Trimarginated garnet. f Peri-hexahedral, peri-octahedral, peri-decahedral, peri- dodecahedralf when the primitive form being a prism with four panes, is changed by the effect of decrements into a hfxahedral, octahedral, decahedral, or dodeca- hedral prism We also denominate peri-dodecahedron a crystal the nucleus of which being a regular hexa- hedral prism, has its'six longitudinal ridges intercepted by as many facets. Ex. Peri-hexahedral sulphated copper, peri-dodecahedral emerald. g. Recurved (racconrci) , when the primitive form being a prism with rhombic bases, the longitudinal ridges con- tiguous On CrystallographT/, 269 tigiious to ihe grand diagonal are intercepted by two facets, which make it apj)ear diminished in the di- rection oF its length. Ex. Recurved sidphated barytes, h. Retreated {retreci)^ when the primitive form being a prism with rhombic bases, the longitudinal ridges contiguous to the small diagonal are intercepted by two facets which make it appear diminished in the direction of its breadth. Ex. Retreated sulphaled barytes. 2. Secondary forms considered in themselves, and as being p2trely geometricaL The crystal is called, a. Cubical, when it presents the form of the cube, which in this case is always secondary. Ex. Cubical flualed lime. b. Ciihoidal, when its form differs a little from the cube. Ex. Cuboidal carbonated lime. c. Tetrahedral, when it presents the form of the regular tetrahedron, as a secondary form. Ex. Tetrahedral sulphurated zinc. d» Octahedral, when it presents the form of this soiid_, as secondary. Ex. Octahedral muriated soda. e. Prismatic, when it has the form of a straight or oblique prism, the panes of which are inclined li'O'^ amonj each other- Ex. Prismatic carbonated lime, prismatic feldspar. f. Dodecahedral, when its surface is composed of twelve triangular, quadrangular, or pentagonal faces, all equal and similar, or solely ot" two measurements of different angles. Ex. Dodecahedral quartz, dodecahedral zir- con, dodecahedral sulphurated iron. If the dodecahedron had not all itslaces of the same number of sides, it would be sufficient to brin2:thcmto this aspect in imagination, by varying its dimensions. g. Icosahedral, when its surface is composed of twenty triangles, of which twelve are isosceles and eight equi- lateral. Ex. Icosahedral sulphurated iron. h. Trapezoidal, when its surface is composed of twenty-four equal and similar trapezoids. Ex. Trapezoidal garnet» i, Triacontahedral, when its surface is composed of thirty rhombuses. Ex. Triacontahedral sulphurated iron. k, Enneaco?itahedral, when its surface is composed of 90 faces. Ex. Enneaeoniahedral idiocrasis. /. BirhomboidaL when its surface is composed of twelve faces, which being taken by sixes, and lengthened in imagination until they intersect, would form two difr- fereut rhomboids. Ex. Birhomboidal carbonated lime. Wc SiO On Crystallography* Wc say irhhomhoidal in the same manner. Ejc^ Trirhoniboidal carbonatLci lime. «i. Bfform, triform, when it contains a combination of two or three remarkable forms ; such as the cube, the rhoniboid, the octahedron, the regular hexahedral prism, Sec. Ex. Triform su]|>hated alumine. n, CuhO'Octahedraly cuho'dodt'cakedral, cubo-tetrakedral, &c., when it contains a combination of the two forms indicated by these expressions. Ex. Cubo -octahedral fluated lime, cubo^dodecahcdral sulphurated iron, cubo-tetrahedral gray copper. h. Trapezia?ii when its lateral surface is composed of tra- pezia situated on two rows between two bases, Ex. Trapezian sulphated barytes. p. Diieirahed/al, \.G. iw'ict telrahedral, when its form i* that of a tetrahedral prism with dihedral summits, Ex. Ditetrahedral grammatite. q. Diliexahedral, when it forms a hexahedral prism \vitb trihedral summits. Ex. Dihexahedral feldspar. We say in the same manner, diocialiedral, d/de- cahedralf didodecakedraL Ex, Dioctahedral topaz, di- decahedral feldspar, didodecahedral phosphated lime. r, Trihexahedral, ietrahexalwdral, pentahexahedral, hepta- hexahedral^ when its surface is composed of three, lour, five, seven rows of facets disposed in sixes the one above the other. Ex. Trihexahedral nitrated potash, pentahexahedral quartz, heptahexahedral ni- trated potash. We also say in the same manner, iridodecahedraL Ex. Tridodecahcdral sulphurated antimoniated silver. — Trloctahedral. Ex. Trioctahedral sulphated lead. Sy B'lgeminated, when it presents a combination of four forms, which, taken by twos, are of the same species. Ex. Bigeminated carbonated lime. t. Amphikexahcdral, i.e. hexahedral in two ways, when by taking the faces according to two diflfercnt direc- tions, we have two hexahedral contours. Ex. Am- phihexahedral axinite. a., Scxdec'irnal, when the faces which belong to the prism or to the middle part, and those which belong to the two summits, are the former six in number, and the latter ten in number, or vice versa. Ex. Sexdecimal feldspar. In the same manner we say octodechncL Ex. Oc- todecimal feldspar. ScxduodecimaL Ex. Sexduode- ciinal Ctjrbonaled lime. Octodaodeclmal. Ex. Ocio- * duodecimal On Crystallography, 271 duodecimal sulphated copper. Deciduodecimal. Ex. Deciduodecimal feldspar. ' jc. Peripolygoval, when the prism has a great number of panes. Ex. Peripolygonal tourmaline. y. Super composite, when the form is very much com- pounded. Ex. Supercomposite tourmaline. rs. Antiemieahedrnl, i. e. having nine faces on two oppo- site sides, is a name peculiar to a variety of the tour- maline^ in which the two summits are of nine faces, and the prism of twelve panes j whereas^ generally, the prism is enneahedral. aa, Prosenneahedral, i. e. having nine faces on two adja- cent parts, is another variciy of the tourmaline, ia which the prism and one of the two summits have each nine faces. II, Recurrent, when, on taking the faces of the crystal by annular rows, from one extremity to the other, we have two numbers, which succeed several times, as 4, 8. 4, 8, 4. Ex. Recurrent oxidated tin. cc. Eiiuid'ifferent, when the numbers which designate the faces of the prism and those of the two summits^ which in this case differ from each other, form the commence- ment of an arithmetical series, as 6_, 4^ 2. Ex. Equi- different amphibolus. dd. Converge7it, when in the foregoing case the series is sensibly convergent, as 15, 9, 3. Ex. Convergent tourmaline. ee. Unequal {Impair), when the numbers which designate the panes of the prism and the faces of the two sum- mits, considered as different from each other, are all three unequal, without being in other respects in pro- gression. Ex. Unequal tourmaline. ff. Hyper- oxidated, i.e. aaite to excess, is a variety of carbonated lime, which contains the combination of two rhomboids ; the one acute, which is the inverse ; the other incomparably more acute. gg. Spheroidal, is said of the diamond with 48 bombaled faces. hh. Plano-convex, is the diamond with' some plane and some curvilinear faces. 3. Secondary forms considered relatively to certain facets, or certain ridges, remarkable for their arrangement or position. The crystal is called, «. Alternate^ w'h^n it hasonitst\^o parts, the one supe- rior J 7 2 On Crys lallog rap hy . rior and the oihcr inferior, faces which alternate among each other, but which correspond on both sides. Ex. Ahernate quartz. Bisaltermite^ when in the foregoing case the alternation takes place, not only among the faces of one and the same part, but also among those of the two parts. Ex. Bisalternate carbonated iin)e, bisalternate quartz. Biiisalternate, when there are on both sides two orders of bisalternate facets. Ex. BibisaUcrnate sulphurated mercury. I, Annulary, when a, hexahedral prism has six marginal facets ranged in form of a ring around each base. Ex. Annulary emerald. We say the same of an octahedral prism with eight marginal facets around bases. Ex. Annular oxidated tin. c. Monastic, when a prism of any given number of panes has, in the contour of each base, a row of facets in number diflerent from that of the panes, and which may be all marginal, or some marginal and others an- gular. Ex. Monosiic topaz. Dislic, when in the same case there are two rows of facets around each base. Ex. Di^tic topaz. Siibdistic, when among the facets arranged on one and the same row around each base, two are surmounted . each by a new facet, which is as it were the rudiment of a second row. Ex. Subdistic peridot. d. Plagt/iedral, when the crystal has facets situated in a slanting direction. Ex. Plagihedral quartz, plagihe- dral zircon. e. Dissimilar, when two rows of facets, situated the one above the other, towards each sunnnit, have a defect in svmmetry. Ex. Dissimilar topaz. f. Squared {tncadrt)^ when it has facets which form kinds of squares around faces of a simpler form already ex- isting; in ttie same species. Ex. Squared fluated lime. g. Slighfly promintui [proyniiiuie), when it has ridges which form a very slight eminence. P^x. Slightly prominent sulphated lime. h. Zonnry, when it has around its middle part a row of facets, which form a kind of zone. Ex. Zonary car- bonated lime. i. Jpophamms, i.e. »??/, when certain facets or certain ridges i)resent some indication useful for ascertaining the position of the nucleus, which would otherwise be difficult to find out, or even to determine, either in point On Crystallographyi, 273 point of direction or the measurement of the decre- ments. Ex. Apophanoiis feldspar, apophanous sul- phurated antinionialed silver, apophanous gray copper. L Blunted {e?nousse)y when it has facets which intercept, and render as it" bkinted, some parts which would otherwise be sharper than the rest. Ex. Blunted axinite, bhuited carbonated lime. m, Contracted^is a dodecabedral variety of carbonated lime, in which the bases of the extreme pentagons undergo a kind of contraction, in. consequence of the incli- nation of the lateral faces. ?;. DUatady is said of another dodecabedral vanety of car- bonated hme, in which the bases of the extreme pen- tagons undergo a kind of dilatation, in consequence of the inclination of the lateral faces. 0. Acutemigled, is a variety of carbonated lime in a hex- ahedral prism, the solid angles of which are inter- cepted by very sharp triangular facets. /?. Defective, is a variety of borated magnesia, in wliich four solid angles of the primitive cube are intercepted hy facets, while ihe opposite angles remaining un- touched, are subject to a kind of defect. q. Superabundant, is another variety of borated magnesia, in which the solid angles which were untouched in th« defective variety, are intercepted each by four facets, in such a way as to make a superabundance where there was a defect. 4. Secondary forms considered relatively to the laws of decrement on which they depend* The crystafi is called, «. Unitary, when it undergoes only a single decrement by- one row. Ex. Unitary telcsia. If there are two, three, four decrements by one row, we say bisunitary, tri- unitary, quadriunitary. Ex. Triunitary peridot, bis- unitary carbonated lime. 1. Binary. LiOifiary, trihinary, &c. in the case of one, two, and three decrements by two rows. Ex. Binary oligistous iron, bibinary feldspar. c. Ternary, biiernary, &c. in the case of one, two decre- ments, &c. by three rows. d, Unihinary, if tliere are two decrements, the one by one row, the other by two ',un'i ternary, if there is one by one row, and the other by three ; hinoternary , if there is one by two, and the other by three, &c. Ex. Uni- ternarv carbonated lime, binotcrnary carbonated lime^ Vol. 35/No. 144. April J 8 10. S The -274 On Crystallography* The nomenclature in all the foregoing expressions, - as well as in those which follow, makes an abstraction oF tlie faces parallel to those of the nucleus, which ex- ist most frequently in the secondary crystal. Among the forms in which the nucleus is entirel) disguised, some liave names borrowed from different consi- derations; and those which remain are so few in num- ber, that I thought it unnecessary to complicate the language by enijiloying a paniculardesignation for them. In order to avoid confounding the words which express the decrements with those which indicate the number of the faces, we may remark, that the former have their termination in hedral, as dodecahedral, or in «/, as octodecagonal, whereas the others end in ary. c» Equivalent, when the part visible {exposant) which in- dicates a decrement isrqual to the sum oF those which indicate the others. Ex. Equivalent sulphated iron. /. Suhtrociive^ when the part visible relative to a decre- ' ment is less by unity than the sum of those which in- dicate the others. Ex. Subtractive pyroxene. a. Additive^ when the part visible relative to a decrement exceed'-: by unity the sum of those vi-hich indicate the others. Ex. Additive sulphated copper. h. Progressive, when the parts visible forni a commence- ment (if arithmetical progression; as 1, 2, 3. Ex. Progressive tourmaline. i. Disjoif/tcd, when the decrements form an abrupt leap, as from 1 to 4 or to 6. Ex. Disjointed sulphurated an- timoniated silver. k. Partial, when there is some part which remains without decrements, while the other parts similarly situated undergo them. Ex. Partial sulphurated cobalt. hich 1 have uniformly received from persons, who 4iave had in oppor- tunity of examining some of'the modern instrumt»nls, have fully convinced me that my opmion w as just. But what- ever may be the nature of the methods which are now in use. or whatever their advantages over Bird's, F never could persuade nn'self that it would be safe to trust to an instru- ment, without a previous examination. To discover the means of accomplishing this" object, is what I have for some time been anxious to effect ; and though I fear my endeavours have not been very successful, f will neverthe- less take the liberty of presenting you with the result. You are aware, I believe, that I use a circular instru- ment for observing both in altitude and azimuth, which was made for me by Mr. Carey in the Strand ; that the ra- dius of both the altitude and the azimuth circle is one foot, and that each is divided into parts containing ten minutes. The construction of this instrument does not difier ma- terially from that of other similar instruments, with which you are well acquainted, and I shall not therefore waste your time by giving you a particular description of it. For the purjiose of examining the divisions upon the two circles, I procured an apparatus to be prepared by Mr. Carey, which will be very easily explained. To the face of the rim which surrounds the azimuth circle, and' with its left end close to the stand which supports the micrometer on the east side, an arc of brass, concentric with the circle itself, and a little more than 90° in length, an inch in breadth, and one eighth of an inch in thickness, is firndy fixed by screws, so as to have the plane parallel to the plane* of the circle, and 'a small portion of its lower surface resting upon the extreme part of the rim. The screws pass through a brass pre, which is fastened to this at right angles, and lies with its broad side against (he face of the rim. Upon the first-mentioned arc. a strong upright piece of brass, about six the Divisions of astronomical Instrumenls. 279 six inches in length, is made to slide, the lower part of it embracing the arc as a groove, and having a clamping, screw underneath, for the purpose of fixing it firmly 10 the arc at any point required. To the top of the upright piece of brass is attached a microscope, with aTnoveable wire in its focus, pointing down to the division upon the circle, not directly, however, but with an inclination to the left of about 30". This inclination is given to it, in order to make it point to ihe same division upon the circle, which is immediately under the micrometer itself, when it has been moved up as near to the micrometer as it is ca- pable of ap[)roachinir« The microscope has attached to it a small graduated circle of brass, and an index, by which the seconds, and parts of a second, moved over by the wirf are determined. To the vertical circle there is likewise an arc applied, of the same length and breadth as the former, but somewhat thicker, and of a radius exceeding that of the circle by about two inches. This greater thickness is given to it, on account of its being supported in a manner which ren- ders additional strength necessary. It is fixed with its broad convex side downwards upon two brass pillars, screwed fast to the plane of the aziniuth circle, and standing in a line parallel to the plane of the vertical circle at the distance of about four inches from it, and on the right sule of the pillars which support the micrometers belonging to » this circle. The pillar, to which the left end of the arc is fastened, is placed close to the lower micrometer of the vertical circle, and the other contiguous to the elevated rim, in which the divisions of the azimuth circle are cut. The right end of the. arc reaches beyond this pillar about ten inches. The pillars are of such a height, and so propor- tioned to each other, that whilst the left end of the arc, which lies horizontally, is raised to within about two inches of the height at which the lowest point of the vertical cir- cle is placed, the whole arc runs parallel to the circle through an extent of something more than 90°. Upon the arc a microscope, with a moveable wire in the focus, is made to slide as in the former case, and to point to the divisions upon the vertical circle, not directly, but with an inclination of about 30^ to the left, in order that the same division (which is the lowest upon the circle) may be seen througli it and through the lower micrometer at the same time. I will now proceed to show you in what manner the examination of the divisions upon either circle may be S 4 performed. 280 0?i a Method of examining performed. The process is precisely the same in both cases^ and will of course be described in the stme words. The first point to be examined is th.it. of \m°, uliich must be done in the usual way, by bringing the j)oints of O and 180° to the moveable wires of the opposite micro- iTietcrs, and then turning the circle half-way round, and bisecting the points again with the moveable wires ; and lastly, taking half the difference betwixt the distances of the wires in the two positions of the circle for the error at the point of 180^. Having now bisected the point of zero with the moveable wire of the micrometer, which »s in- tended to be used in the rest of the process (for wc shall have no further occasion for both), we must slide the mi- croscopo along the arc, till by moving the wire a little wc can bisect the point of QO'', and then the micrometer must be firmly clamped to the iirc. The circle must then be turned til! the point of 180^ is brought to the microscojx?, and that of 90" to the micromcicfr, so that we may be able to bisect each by a slight motion of their respective wires. This being done, we must observe, from the positions of the wires, how much the interval betwixt them has in- creased or decreased in the measurement of the new arc ; and this increase or decrease must be noted down with a 4- or — acc6rdmgly. In the same manner wc must pro- ceed through the remaining two arcs of 90", observing and noting down the diflerence betwixt each and the original arc. The point of zero must now be brought again to the micrometer^ and bisected by the moveable wire, and the microscope be made to slide back along the arc, till by moving the wire a little we can bisect the point of 60^ 5 and uhen this is done, ihe microscope must be clamped. We must then measure the arc of 60^ against every succeeding arc of 60" in the circle, precisely in the same way that we measured the first arc of 90" against the other three. The arc of 45*^ is next to be measured against every succeeding arc of 45°, and this will complete all that is necessary to be done in the early part of the morning before the heat of the sun can have affected the ten^perature of the instru- ment. The rest may be performed at onr leisure. You will immediately perceive the object of this kind of measurement. It enables us to determine, with any degree of accuracy that may be required, the proportion which the first and every succeeding arc of the circle, con- tained betwixt the micrometer and the microscope, hears ^o the whotp circle; and of course the absolute length of th« the Divisions of astronomical Instmmenls, 281 the arcs themselves. Lei a denote the real length of the first of these, and ±a\ ±a'^ ±«'", &c., the difference betwixt the first and second, the lirst and third, &c. re- spectively ; let A represent any other arc whose length is known, and which is a multiple of a, as marked upon the instrument, and let this muUiplc be expressed by n. Then will a -f {a + g') + (a + a") + (a + o!'') + &c. ... (a 4. a:'' "~') = A, and a = A-a--." -.^-^'-^^ ^^^^^ it is evident, that if there is no error committed in t!i» measurement of any oF these arcs, we shall have the value of «, and consequently of a -f a\,a -f af^ y a -\- a'/\ Sec, and of any arc, comprehending any number of these, accurately determined. But if there be an error of e in the measure- ment of the first, of e\ e'\ e^\ &c., in the measurement of the second, third, 8cc., respectively, then we shall have the following equation for determining «, viz a + {a -^ a -\-e +e) + (a + a'' + e 4- e'') + &c {a + a'"*"""~ ^ + e + ef'^'" ) = A, and consequently a will appear to be equal to , which differs from its true value by — 1 p + f' + e" + .. ....n-1 Hence it follows, that the value of the p^^ arc (p being greater than unity), as deduced by this process, will differ irom Its true value by -. ■■ ^e—e^^^'"^^" , and that if we add any number p of these arcs together, in order to determine the value of the arc which is equal to their sum, we shall have an error in this value (and the expression holds when p is unity, or the first arc only is taken) equal to p ,„.... p „,...« — 1 n — i .e -k- e -^ e + p^],e-e'-^e''--,„e"'-'^- '•— e— f— ... e ' + V-f ^ + e ^ + ...e , NoW, 11 if wc suppose e to be the greatest error to which we are liable in the measurement of any arc, and each of the sue- cccdiner errors to be equal to it, and likewise that e', ^^ 889 On a Method of examining ...e^'"'"^"" are all negative^ then it will appear that ^^~^x 2pt probable error, and to ascertain the amount of the greatest to which the process can in any case be liable. Let the arc of 30° be now measured against every suc- ceeding arc of 30° in the first, third, fourth, and sixth arcs of 60°, and let the length of each be determined from a separate comparison with the arc of 60^, in which it is comprehended, and not from a general comparison with all the four. The arc of 15° must then be measured against every succeeding arc of 15° in the first, third, fourth, sixth, seventh, ninth, tenth, and twelfth arcs of 30% and the value of each deduced from a comparison with the arc of 30^, in which it is contained. When this is done, we shall have determined the length of every succeeding arc of 15% of the first arcs of 30, 45, 60, 75 (= 60 + 15), 90, 105 (= 90 + 15), 120 (= 60 + 60), 135 ( = 90 + 45), 150 (= 120 + 30), 165 (= 150 + 15), and 180^ in each semi- circle. We must next measure the arc of 5^ against every suc- ceeding arc of 5® in the whole circle, and deduce the values of the first, and of the sum of the first and second, in each succeeding arc of 15% from a comparison with the arc of 15" in which they are contained. We must then proceed to determine the values of the first arc of 3° in each 15% and of its multiples the arcs of 6, 9, and 12°. We must also put down the value of the last arc of 3° in each arc of 15°, and then deduce the values of the first and last arcs of 1° in each ?rc of 15°, tVom a comparison with the arc of 3° in which they are respectively cwnlained. We shall now have measured in each arc of 15° the first arcs of 1,3, 5, 6, 9, 10, 12°, and by taking the la&t arc of one degree, which has likewise been determined, from the arc the Division^ of astronomical Inslrumenis. 283 arc of 15% we shall obtain the first arq of 14°. ThQ first 7° of this arc being measured against the second, we as- certain the value of the first 7"; and then, by measuring the first 4'' of the remaining arc of 8^ against ihe second, we shall get the value of the first 4°, which added to the arc of 7°, before determined, will give us the length oF the first arc of 11°. The first -2° of the remaining arc of 4^ must then be measured against the second, and we shall get the value of the first 2", and by adding this arc to the arc of 11°, we shall obtain the value of the arc of 13^. By taking away the first arc of 1° from the arc of 15°, we get the remaining arc oF 1 1^; and then having determined the length of the first 7^ of this arc, by measuring them aeainst the second, we must add it to the arc of 1°, and we shall obtain the arc oF 8°. The length of the first 4^ of this arc will then be easily known, by measuring them against the second, as will aFterwards that of the first 2° in the arc of 4° itself, by measuring them against the second in the same arc. We have still to ascertain the lengths of all ihe first arcs of 10, 20, 30, 40, and 50 minutes contained in each de- gree, for I shall only consider the case in which the circle is divided into parts oF 10 minutes. Now the length of the first arc of 30' will be obtained by measuring it against the second, and the lengths of the first and second arcs of 20' (whose sum will give the arc of 40^) by measuring the first against each of the remaining arcs. The length of the third arc of 20' must likewise be put down, and then the first arc of lO' being measured against the second of the arc of 20*, in which it is included, and also against the two arcs of lO' contained in the last arc of 20', its own value, and that of the last lo' in the de2:ree will be deter- mined from a comparison with the arcs of 20', in which they are respectively comprehended. The length of this last arc of lO' being taken from that of the whole degree, will give us the length of the first 50', and complete the operation. In order to ascertain the greatest possible error to which we are liable in the examination, let s denote in parts of a second the greatest that can be committed in bisecting any point upon the limb ; then, since this error may occur at each end of the arc, it is evident that e in the expression deduced above O^—^ x '2pe\ will become 2e, and the ex- pression itself -^^ — X 4/)£. Hence the possible error will be f 84 On a Method of examining be ^ 4£ = 2s at 180^; --- 4- ^- x 4s = 3£ at 90" j 2i 3 1 2 3—2 — 4--^- X 45 = 3-33a at6(P;--.X 2s + -^ X4 X 5f = 4sat 120\ The greatest error must therefore lie betwixt 90 and 120'% aiuT nearer to the extremity of the latter ihan of ihe former arc. At 103^ it will be d'dOs; at 11 F it will be 5*506 ~y . 1,3£ + ^^ x 4 x 2£ = 9,70 £ \ and at 1 1 1^ lo' it will be 9,70 ^ — -- • 1,0 4c (the excess of the error at IIP above that at 112^) + 3*33 e = •J2-86£, which will he found to be the greatest error l)et\vixt 105 and 120% and of course the greatest in the tirst semi- circle. In the other semi-circle, the process being the same, the possible errors must necessarily be the same at the same distances from the tirst point, reckoning the con- trary way upon the circle. I'he magnitude of the quantity e will of course vary upon circles of the same radius, according to the excellence of the glass employtd, and the accuracT of the examiner's eye. It will seldom, however, exceed one second upon a circle whose radius is one foot; and in general it will not amount to sd much. I find that 1 can read off, to a certainty, within less than three fourths of a second ; and hence I conclude, that I could examine the divisions of my circle without being liable to a greater error than ^'^3 seconds, and those of a circle of three feet radius wiuDut the risk of greater error than 3*21 seconds 'o those people who are accustomed to entertain such exalted notions of the accuracy with which astronomical instruments can v^ith a certainty be divided, this error, f dare say, will appear very considerable; but for my part, I am perfectly satisfied that it bears but a small pro- portion to the accumulated error which may take place, in spite of tlie utmost vigilance of the artist, in an instrument divided according to any metliod which has hitherto been made public. I wfnidi not, however, remark upon the very great iniprobability that the error of examination should ever attain, or ap[)roach, to its extreme limit, as this must be sufficiently obvious to any person who is in the least degree conversant with the doctrine of chances ; but it may be proper to observe, that we have it in our power (and in this respect the examiner possesses a most iniportant ad- vantage over the divider of an instrument) to diniinish its probable amount, as nnich as we please, by bringing the jjfioveablc wires of the micrometer and microscope several timvs the Divisions of astronomical Instruments* S85 times, to. bisect iheir respective points in the measurement oF every arc, and taking a mean oi' the different readings^ o^'for the true position oi' the wire at the real bisection of the point. The wire n)ay be niovcd in this manner eight or ten times at each point (it" such a degree of caution should be thought necessary) and the mean taken in little more tlian a minute ; so that the lime of performing the work will not be so much increased as might perhaps have been apprehended ; and when it is con^pleled, wc may rea- sonably presume that the distance of every point from zero (whilst the temj)crature of the circle continues uni- form) will have been determined with sufficient exactness for every practical purpose. OF the time necessary for the examination, a pretty cor- rect idea may be formed by considering how many mea- surements are required, and allowing about a n)inuie and a half for each ; i. e. a quarter of a minute for bringing the extreme points of the arc to the micrometer and the mi- croscope, and a minute and a quarter for making the se- veral bisections. Now, in dividing the whole circle into arcs of 15° each, it wilj ai)pear that forty-four measure- ments must be performed; and to examine every point in each arc of 15°, there will be l6l required, making in all 3y0S measurements ; and consequently the time necessary for completing the whole work will be 3S62 minutes, or about 98 hours. The time and labour required for this examination are^ 110 doubt, very considerable; but it ought to be recollected, that it will render any great degree of precision, in dividing the instrument, totally unnecessary. Whoever indeed employs this method of examination, will be virtually the divider of his own ir.strument ; and all that he will ask of the artist, is to make him a point about the end of every five or ten minutes, whose distance from zero he will de- termine for himself, and enter in his book to be referred to when wanted. We may likewise observe, that by this €xaa)ination we shall not only be secured against the errors of division, but against those which arise frt)m bad center- ing, and from ilie imperfect figure of the circle, and which , in general are of too great a magnitude to be neglected. It will,. I dare say, have occurred to you, that whenever we are desirous that an observation should be particularly exact, we may guard it against the effects of unequal ex- pansion or contraction in the metal, by means of the ap- paratus which I have described : for wc have onlv to mea- sure the.arc which has been. determined by the observation against S86 Oil ilie Divisions of a$tronoiniccd Instruments, against the whole circle, or against the muliiple of it, which appn^achcs nearest to the circle, and from thence to deduce its value in ihc manner explained above, and we shall either have entirely excluded tlie error which we apprehended, or have rendered it too snudl to bo of any importance. Sup- pose, for instance, that the arc determined by the observa- tion was 4 8"^; then by measuring it against the whole cir- cumference increased by an arc of 24-, we shall obtain a result free from any greater error of unequal temperature, than one eighth of the increase or decrease of this arc of 24^ beyond a due proportion to that of the circle itself. This expedient gives us all the advantages of the French circle of repetition, without the inconvenience arising from being obliged to turn the instrument, and move the tele- scope, so many times in the course of the observation. Nay, r am p;rsuaded that the result may be made more accurate in this way than by the French method, because not only can the object be more frequently observed, but the contacts or bisections, it may be presumed, will be more exact when the observer is not disturbed by the hurry attendant upon the use of the repeating circle ; and with respect to any error in the instrument, from whatever cause it may arise, it will be as effectually excluded by the process which I recommend, as by moving the telescope round the circle. Besides, this method is applicable either to the azimuth or altitude circle, or iudeed to any circle which turns upon its own axis ; whejeas the French method can never be applied to the azimuth circle, nor to any other circle which does not turn both upon its own axis and upon one which is perpendicular to it. After all, however, it is possible that the process which I have been explaining to you may be no new discovery, and that you may be already acquainted with it. If this should be the case, you will be kind enough to inform me. At any rate, indeed, I should esteem myself greatly obliged, if vou would favour me with your sentiments upon the subject, as soon as you can do it with perfect convenience to yourself. I am, dear sir, yours, 8cc. William Lax. XLVIL Or, [ 287 ] XLVII. On Azimuthai Refraction, ^ ToMr.Tillocli, Sir, idAViNG recently directed my attention to the sub- ject of retraction in azimuth, and having mentioned the subject to Mr. Williams, ofWells (at piesent residing in Islington), I have received the following letter, stating phasnomena observed by hinj on the 28th ult. depending on aziinuihal as well as vertical refraction. Similar effects were observed on the same day in the north environs of London, by Messrs. Whites of Finsbury-square, and my- self; but being at that time in the prosecution of other in- quiries, we could not attend particularly to the subject. Mr. W. however, between one and three o'clock, observed three sets of angles (in which the churches of St. Paul, St. Mary Islington, Hampstead, and Stoke Newingtoa formed principal objects), without having any reason to suspect error arising from azimuthai refraction, the fog by this time being more uniformly dispersed, forming a general haziness in the horizon, but not reaching so high as the tops of the above spires. I am, sir, Your obedient ser\''ant, 26, Garlick HIU, March 10, 1810, Jos. StEKVENS. Mr, Steeveiis, — Sir, Although I stated to you at our last interview, that in a very great number of observations, (probably a hundred,) made on Harrow, Hampstead, and another church lying S. W. of Primrose Hill, distance about four miles, I co^ld discover no azimuthai refraction as you term it ; yet I have since, viz. on Fast-day, observed it twice in a very striking manner,- and must do you the justice, before I quit towri, to say I am quite satisfied as to the fact. On tlic above day about nine A.M., in my way to Kil- burn crossing some high fields to the south of Primrose Hill, I observed, from the interposition^ of the fog, that se- veral ol)jects put on a strange distorted appearance, and that the spire of Islington church appeared crooked (see Jirist aj)pearance^ PI. VI 1) ; and in less than a minute, about 20 fett ot the upper part appeared insulated and not imme- diately over the under part, but as in the margin. (See second appearance,) I immediately screwed my telescope into the post of a fence which was near me ; but before I could adjust it, the • ' , spire 288 On Azimiithal Rcfractkiu spire became indistinct, being now wholly enveloped in the foe;. I now directed the telescope to llamjistead (Harrow beTncr invisible), the upper part of wliicb was tolerably di- stinct, ahhougii there was a tliick fog at the bottom of the hill. As soon as I had a tolerably good intersection, I quitted hold of the telescope, and found it remarkably steady, it being quite calm ; f soon observed the tower to increase in its height, and shortly after the upper part ap- peared separated from the lower; the lower part retiring a little to the left, while the upper part v/as stationary in azimuth, but increased in altitude; in three or four minutes the top was considerably elevated, but still coincided with the vertical wire, and began to become indistinct as if rising into a cloud ; but before it was quite obscured, I thought I discovered it to be a little to the left of the wire ; the bottom part was now hazy, and still more to the left, apparently about ^ of the whole diameter of the tower; in which situation it disappeared. Islington spire was now just visible: it appeared upright, but as far as I could judge by intervening objects was much elevated. The telescope remained unaltered until the fog sufficiently cleared up for further observation on Hamp- stead, which was near three-quarters of an hour, i now found the top and bottom joined, and nearly in the same situation where the bottom ai:)peared just before its obscu- ration, viz. considerably to the left of the wire, where it remained until the telescope was removed It would thence appear, that when I first made the intersection the tower had acquired its greatest elongation, and perhaps might even then have been on its return. 1 learnt from a gentleman in the course of the day, that one end of a row of houses near Holloway appeared to him first much higher and afterwards much lower than the other, although he did not change his situation : — and from another, that the top of Primrose Hill, with some per- sons on it, appeared to him separated from the bottom and floating in the air, and that he had seen a similar efiect on Qther hills several times before. I am, sir, Your obedient servant, Vpper Street, Idiugto% , ClIARLES WlLLIAM^S. March 5, 1810, XLVIII. Second [ 289 ] XLV^III. Second Vindication of Dr. HerscheVs Theory of Coloured Rings j in Answer to an anonymous Reviewer, :. To Mr, TillocL Sir, X HE rhembers of the club who, formerly addressed; you, have lately seen, in the twenty-firstNumber of the work called The Retrospect, some strictures on their vii>dication of Dr. Herschel's Essay on the Newtonian concentric 00-^ loured rings, which you honoured with a place in yovir Magazine for November last*. , , Our main ohjeci in that communication, was to assert the validity of Dr. Herschel's important e;xperiment de- scribed in the thirty-first article of his Essay. This ex--, periment, the retrospectors, in their thirteenth number, at;- tcmpted to set aside as nugatory^ by affirming that the wedge, of air described by Dr. Herchel was much too thick for' exhibiting the coloured streaks which, according to the Newtonian doctrine of the fits of easy reflection and easy transmission of the rays, would have been seen in it, had it been sufficiently thin. In our former paper we showed^ on the authority of sir Isaac Newton himself, that the re- trospectors had asserted what was not just; and that Dr. Herschel's wedge, according to his measures minutely stated, was sufficiently thin for exhibiting the coloured streaks, if the Newtonian fits had a real existence; and that, according to this hypothesis, the author had a right to expect such coloured streaks ♦ which failijigj or not ap- pearing, he had a right, as he contended for, to conclude that these fits are imaginary. One proof concerning the competent thickness of his wedge being so complete, and so much held up to view by appearing in your excellent philosophical miscellany, the retrospectors have thought it necessary, as it would ap- pear, to strike to it, by saying in number twenty-one, page 403, '' We now come to the last and the most plausible objection that Dr. Herschel's friends have advanced to our remarks ; and here we grant, that such a wedge as they have described ought to have produced the effi^cts which Dr. Herschel expected from it." Now wc must observe that the wedge of air we described was no other than the wedge described by Dr. Herschel: and what he expected from it, and what every body else must have expected, was this ; namely, coloured sireaks, — provided the Newtonian • Philosophical Maj^aziue, vol. xxxiv. p. 359. Vol. 35. No. 144. Jpril 1810. T fitfl 59© Second p^vidicationlpf Dr, lUrscheVs Theory , ^e, ^ts really existed, bi^t wg^cQlourctJ freaks if such fijt^w^re imaginary. Tbe experiment was most careFuily made, as appears by tlie thirty- first articlcj and no symptoms what- ever of such coloured streaks were perceivable. Hence t!ie author considered it as an cxp^rimentmn crucisj dis- proving the reality of tlie Newtonian fits. After this result of the experiment, am\ the admission of the retrospectors as above quoted, it niiirh.t have been expected that they would no longer have resisted such evi- dence, or the just conclusion from it : — but no such thing ;f' we now find them disputing the point as much as ever, by 7tetv assertions and contradictions, as totally groundless as that whose fallacy we have convicted them of. They imme»* diately after the aijove quotation, now allege, that on ac- ■ count of corpuscular repulsions, &c., the wedge of air de- scribed by Dr. IJerschcl could not have been so thin as his measures, which before they did not challenge, show it to be; or so thin as to jiroduce streaks accordinq^ to the Newtonian doctrine of the fits ; than which nothing can be more wide of the fact. ; .. , But, in another place, \te find something prodigiously inconsistent with all this contention for extreme thinness of the wedge, before it is capable of showing streaks. In page 410, where the retrospectors want to set aside Dr. Herschel's explanation of the bow streaks which he has shown to be occasioned by the application of a plain re- flecting surface under the base of the prism, how do they do so? Still i)y resorting to the Newtonian doctrine o?' the fits. An(\ now'theywould have these bow-streaks tai be produced by the plate of air between thebase of ihfe' prism and the reflecting surface applied to it, in conse- quence, they say, of i\\*t great thickness of this very plate, occasioned by their corpuscular repulsions. We shall say no more of such flagrant contradictions. In the sanjc spirit, in the concluding paragraph, page 412, they deny that wfiat Dr. Herscliel calls th^ critical separation is ca- pable of producing the bows; not perceiving that sir Isaac Newton has explained the formation of his blue bow on this verv principle, as Dr. Hersthei has explained his red bow. ' ' ' ^ ' 'i In short, both attacks of the retrospectors abound with- siTTiilar inconsistences and conti;adictions, which we think' w^holly undeserving of notice ;• as' with such'tippoitents we cotisider fiirther drscussi'ons tcf-bc^Vairi. 'XLIX. On £ .291 ] XLtX. Ucport made to the French Institute on a MenwiT of i\[. Dklarochr 071 the Air- bladder of Fishes, Bv X HE mathematical and physical class instructed Messrs. "Lacepctlc, Vauquelin, and myself, to render an account of a mcmjir by M. Francis Delaroche on the, air-bladder of lishes. As several naturalists have been of late employed in di- recting their attention to the organ which is the object of this rnenioir, and to its functions, we do not think it will be improper to preface our report by a historical view of what has been said on the subject ; a recapitulation for which M. Dclaroche himself has furnished ua with ample materials. The air-vessel of fishes is too remarkable, it strikes the eye too forcibly on the first opening of the animal, and dif- fers too much from every other organ, not to awaken the attention of naturalists ; but, like most objects in compara- tive anatomy, it has long produced more conjectures and hypotheses than exact observations and experimental re- searches. Rondelet * confined himself to the observation, that it existed more constantly in fresh than in salt-water fishe^, and that it probably serves to assist them in swimming. ,f Marcus Aurelius Severinus risks an opinion that the air. of this vessel was produced along with the animal; which proves that he had never perceived any communicalion with it outwards. Gauthier Needham (in 1668) was the first who entered into more detailed inquiries, and inserted them in a book, where no one would expect to find them ; namely, Dejor^ mato fcetu f. Adopting the general idea of the utility of this bladder for swimming, he explained how flat fish arc enabled to do without it -, he described the two tunics of this organ, as well as the varieties of its form, and the origin of the canal of communication. He shows that th« vessels are more abundant than are requisite for its own nutrition ; that it is probable that some organic function is exercised by them, and that the blood contained in them has some connexion with the air: but judging that it would be difficult for the air to penetrate into it from with- out, in certain fishes, through substances which fill the • Hi St. Pise. 1554, pp. 26 and T3. t Bilhoth. de MarigeL ii. pp. 713 and 714. T 2 Stomach 292 Report on a Memoir of M* Delarochey stomach, he conjcctureil lliat this fluid is secreted there,, and that it proceeds from thence into the stoniitch, where U assists in tlie prr)ce!is oF digestion : he even points out the red bodies which ojierate this stcrction in the snake. Borelli explained in detail, in 16/6, the method in which the bladder is used in swimming. Me observed that fishes, whose air-bladders burst, remain at the bottom of the vva- ter, as well as most of those which are naturally deprived of it ; and concludes that it is intended to render the body of the fish sufficiently light to be in equilibrium with the water: he added, that by compressing the bladder, or by abandoning the air whrich it contains to its elasticity, the ftsh can augment or diminish its total specific gravity, and assist it in its ascent or descent. He supposed, that the canal which establishes in certain fishes a communication between the air-bladder and the stomach, must be a me- thod of varying or renewing the quantity of air *. To conclude : he has neither described the varieties of the structure of the bladder, nor determined in what fishes it exists, and those in which it is wanting. Bedi resumes the observations of Needham. He added some details on those fishes which have no air-bladder, and on the red bodies in the interior of several of these organs. He also stated, that he had m vain sought for the canal of cottiiDunication in certain sea-fishes 5 but he thought that it was his fault, and this opinion of the generality of the existence of the canal has even reigned to the present time among some others. These remarks of Redi are still to be found in a book entitled, Ol>servatio7is sur les Ainmaux vi- vans contenus dans les Animaitx vivans. Florence, 1684. Ray and Willoughby, without making fresh inquiries, and without deciding on the manncF in which the air is introduced into the bladder, disputed the idea of this air bemg useu m digestion, and reduced the bladder to its em- ployment in swimming, according to the ideas of Borelli. They insisted on the muscles peculiar to certain vessels, aMd mistook for them the red bodies in the interior of some others f. The same opinion on the use of the bladder was sup- ported by Preston tj by Perrault§, and by Petit ||. Per- rault made the important observation, that there arc fishes * De Mot, j4nimaK cap. 23. De Nalatu. f Willoughby, thst. Pwc. 1686, pp* 12 et »eq. 1 Phil. Trans- xix. p. 4I>9. C Mt'Lanii/ue des /InimmuCy pail II. ch. iii. vol ii. p. 383 of his works, l721« il Mem, (It Cjicadt i733» without on the A'lr-hladder of Fishes, 293 wiihout any canal, and that it is in the latter that the red bodies are found, which arc intended for the separation of the air. He added, that in those which have a canal, the air does not issue from the bladder, although it be com- - pressed; a remark too much generalized. Petit, on the contrary, thought he had discovered in the canal of the carp, valvuli which admit of the air escaping, but not pf returning. Notwithstanding the observation of Perrault, Artedi still ascribed to all bladders a qanal destined, according to him, for the introduction of air: but, with the exception of Bo- relli's*, there is no opinion given respectmg their use. It is the same case with Gouan, Bloch, and a variety of other authors, who add nothing in other respects to the details previously acquired. But, admitting in its fullest extent this chief employment of the air-bladder, we might still suppose it to have acces- sory uses, and in particular we must defer giving any opi- nion as to the origin of the air which it contains. This was the conduct pursued by Vicq d'Azyr in 1773 J. He imagined that the air originated in the stomach, from whence it entered, charged with nutritive particles, into the air-bladder, in order to be absorbed by the vascular system. He was followed by Broussonnet in this idea§ under some modifications. Erxleben entertained the same idea respecting the propa- trs^ tome vii.; and hi*3 Pljysiological W^orks, tome ii. p,203, § Fz/r. Posf.t. rur. liespir. sect. V. ....,., , i \ \\ 1776, in a memoir on the subject; and also in his Natural History, edit. 1797. p. 279. ''- ' • '^ 1 Ncv. Conim. Petropqlit. tome xlx. 1775. ** Hist. Xat. 1T24, p.. 390..* T 3 Monro, «9* Report on a Memoir of M, DelarocJie, Monro, Av ho in his work on fishes oujrlit to have thrown a great deal oF light on this suhject, has 'added but little to what was known before on this subject. He made the same distinction with Perrault between bladders with secre- tory red bodies which have no canal, and those which have a canal and want these bodies ; but he does not mention any French anaioniist; perhaps because he had never read any of their \' orks on the subject. He remarked that the genus anguilla formed an excep- tion to the rule, from having the canal and red bodies. With respect to the other parts of the question, he did not decide upon the use of the bladder ; and merely inquired, if fishes could not, in swallowing, distinguish the bubbles of air from the mass of water, and make them pass in pre- ference into this oroan. JVl. Fischer, now professor at Moscow, published in 1 795, atLeipsic, a particular dissertation on this subject : in which after having given an cxtractof »he writing^s of his pre- decessors, and having comnmnicated his own observations on the carp and the tench, he hazarded the opinion, that the air-bladder, independent of its uses for motion, is also a supi)lementary organ of respiration, destmed to ab- sorb the oxygen from the atmospheric air contamcd in wa- ter, as the gills are destined, according to him, to absorb The oxygen of the water itself, by decomposing it. M. de Lacepede supposes, that certain fishes may at least fill their bladder with the gases resulting from the decompositions which their respiration occasions. He thought that it was frequently hydrogen with which it was filled, and he mentioned tenches in which he had collccied precisely this kind of gas. Finally, M. Duvernoy, editor of that part of Cuvier's comparative anatomy which has for its object the air. bladder of fishes, adopted, in common with M. Cuvier, the opinion of Needham and Ka^hlrcutcr, that the air is produced in the bladder by secretion. He also described some of the organs of this secretion in fishes not before observed ; but, from too much precipitation, he forgot to advance the principal argument, founded on the absence of all canal of communication in many species. He concludes, from the absence of the vessel itself in fishes belonging indis- priminately to all descriptions of families, aiid even to ge- tiera ll'iC o^her species of which art fiunished with it, that its iFunctions cannot be very essential to litf . By comparing Its proportional volume with the nature of tlu* movements of tyery .♦ish, and by examining the supplementary means grautecj on the Air-hh^ldps of Fishes^: \\ $95 granted to those who have it not> and the various eflfeots of th6se means, lie arrives at the conclusion that it is essen- tially an organ connected with loco-motion. lie expresses his astonishment at the discordance hetwecn the analysis hitherto given of the air contained in this blad- der; some, like M. Fourcroy, having found hardly any thing but azote; others, like M. Configliati, havjng found so much as 40*0 of oxygen ; while others, like Mr. Broadbcli, found the quantity variable in the same kind of fish ac- cording to circumstances. M. Duvernoy concludes with suggestnig that chemists should inquire into the causes and limits of these variations ; a precise knowledge of which could alone decide a great number of the questions in dispute. Messrs. GeoflT.oy and Vauquelin on one hand,,, and M. Biot on the other, have recently made a great part of the experiments which were pointed out as requisite by M. Duvernoy. M. Biot, in his first voyage to Tvica, examined the air in the bladder of several fishes of the Mediterranean, and found that it varied from pure azote up to S70 of oxygen, with very little carbonic acid, and without any hydrogen, and that in general the oxvgen is the more abundant, in com- parison to the azote, as the lish comes from a greater depth, althougl) the water at these great depths does not contain a purer air than that which is at the surface. ■ He also made the curious observation, that in fishes sud- denly drawn from a great depth, the air-bladder ceasing to be cx)mpressed by the enormous column of water which bore upon it, is dilated so suddenly that it tears the intes- tines, and is ejected from the mouth. As to the origin of the air contained in it, he seems tu think it has been se- creted. The experiments of Messrs. Vauquelin and GeofTroy, pub- lished by M. Biot, confirm his own on the subject, so far as the fishes on which they were made, living in our fresh waters and at very small depths, gave but very little oxygen. Thev agree also with other more ancient experiments of M. F(mrcrov, who had found nothinir in the bladder of the carp but az<;te ahnost pure, and with the analysis made by M. Humboldt of the air in the bladder of the gymnotus electricus, which consisted of 96-0 of azote and 40*0 of oxygen. Such WHS the whole of our knowledge of the air-bladder of fishes when M. Delaroclie read his memoir to the Instir tute. But in order to complete ,the. series of facts which are T 4 necessary 'Sflf6 Report on a Memoir of M. Delaroche, necessary to guide us in forming an opinion of his theory, we think it right to say a few words upon two memoirs pub- lished since. One of these, by M. GeoflTroy, refers to an earlier memoir, in which he develops, anatomical! v, the means by which the fish compresses or relaxes its bladder, in order to descend or ascend. Indeed, he says at the same time, in the intro- duction of'^his memoir, that the bladder is bv no means an organ of motion by itself; but this is because he thought that those who regarded it as such, suppose that it is dilated by the increase of the air which it contains, and vice versa, an opinion which no person seems to have entertained ; for it is always by the action of the muscles that it has been made to be compressed or dilated : on this subject, therefore, M . GeoflTroy is really of the opinion of Borelli, which is the commonly received idea. . The other memoir to which we have alluded, is by Messrs. Humboldt and Provencal, and has for its chief object the respiration of fishes ; but these authors have naturally been led to examine the air in the swinnning-bladder. They operated upon river fishes, and found the fax vari- able in composition from 99*0 of azote to 87*0. They have observed as much as 5*o of carbonic acid. They made some tench respire hydrogen, and yet their air-bladders when examined exhibited none; by keeping them in oxygen, however, the proportion of the oxygen in the bladder was somewhat increased. On removing the bladder fron) them, thev were not prevented from producing by their respiration the ordinary eifects upon the atmosphere; they were even able to raise themselves in the water, although they gene- rally remained at the bottom of the vessel. Thus, in the numerous works we have analysed, almost every possible hypothesis has been proposed, attacked, or defended, and examples have been given of almost all the combinations of organization that could be devised, M- De-aroche had only therefore to examine these organiza- tions a little further, in order to reduce them to general rules, and to weigh over agam the arguments advanced for or against every hypothesis. Let us see how he has acquitted himself of this task. — His residence at Ivica, Formentero, and on the coast of jBpain, with Messrs. Biot and Arrago, having furnished bini with opportunities of examining a great number of Mediterranean fishes not to be seen any where else, and their air-l;ladders having chiefly occupied his attention, he ^pptinued his inquiries after his return, on pur common .'■•-'• fresh- on the Air-lladder of Fishes, 297 fresh- and salt-wjiter fishes; hence he has furnished upwards of fifty particular descriptions oFthe air-bladders of as njany species of fi«ih, several of which have not hitherto'bccn de- scribed. These descriptions, added to those which former authors had given of" some species which M. Delaroche could not find, form the materials of his present memoir; and he has placed his own at the entl oF the work, as so many proofs of the 2;eneral propositions which he lays down. In the body of the memoir he treats successively of the anatomical structure of the air-bladder, of the nature of the sources of the air which it contains, and of the functions which it exercises. He speaks in the first place of its existence, and gives a list of those fishes which have it, and oF those in which h is wanting. The result? of this list, which a^lds several species to those which had already been adduced with respect to this subject, are nearly the same which had been alVeady drawn ; namely, that the existence or non-existence of the bladder does not correspond with the other afiinities of or- ganization which connect fishes with each other. He afterwards speaks of the various situations of the bladder, (^f its variation in size, and in the configuration of its tunics, (an article in which he compares the internal membrane to the serous membranes) ; and finally, of the particular muscles which it has in several fishes; and he gives a more detailed description of these muscles than is to be found in the comparative anatomy of M. Cuvier. What he says on the subject of the canal of communi- cation also presents a great number of novelties. On this head he has made some very acute remarks, and has as- certained that this canal is \Vanting in the greater part oF sea fishes. He did not find it in any of the jugular or thoracic classes, which compose nearly three- fourths of the total species of fishes with which we are acquainted. The lec- tures on comparative anatomy had assigned this canal to the nranoscnpe, which is a jugular ; but according to M. Dela- roche, the authors of' this work have made new inquiries, and found that they were mistaken. M. Delaroche has st^tdied in a particular manner the red bodies with which certain bladders are furnished. He found them, like Perrault and Monro, in all those which want the canal of communication, and in the anguilla genus although furnished with this canal. Our author gives a very detailed description of these bo. dies, in the gadi, the trigli, the perches, sonie lalri and holocentreSi as well as in the atkerina rhepsetus^ the Henm-us physis, 298 Report on a Memoir of M. Delaroche, physis, the orphius ct esox htlovus, aiul lastly in the ccl and the conger. We have verified that part of the descriptions which re- fers to the species with which we are Faniihar, orconld pro- cure, and have found them generally correct. It appears to us, however, that M. Delaroche grants too great a homogeneity to the inner texture of these bodies. One of our number, who, along with M. Duvtrnov, re- cently made some inquiries in order to verify this point of anatomy, found these bodies in the larger fishes formed of lobes flattened like ribands, placed almosi parallel on each other, very distinct from one another by clearly marked in- tervals, and proceeding obliquely in various directions from the proper membrane to the internal menibrane of the bladder. The distribution given by M. Delaroche of the vessels which issue from the red bodies of the eel, and from those which return to it, has also been verified, and found cor- rect ; but he passes rather too hastily over the red body it- self, which is also divided into flakes, separated by intervals, which are frequently found filled with blood. In short, Messrs. Cuvier and Duvernoy think they have found strongly marked relations in the red bodies of fishes wi;h the cavernous bodies ; but their inquiries posterior ti> the memoir of M. Delaroche, are only brought forward here that the Institute may not be ignorant of what has been done on this interesting subject. A full account of their experiments will shortly appear. The author of the present iMenu)ir speaks only from the lectures in comnaraiive anatomy as to certain branching air-bladders, entirely peculiar to one species of fish. M. Cuvier, who had described them w hen on the sea coast, where he had no books from which to determine the spe- oies of the fish, thought it was \hc pcrca lalrax; but other naturalists, besides himself, have since sought for it in vain in the fish so called in tljc systems (jf ichlh\<)l()gy. By unexpected good fortune, the true fish \\hieh was the subject of ol>!fervation was broucht to Paris son)e time ago, and proved to bel(;ng to die rare species denominated by M. Lacepede cheilodipitra, or sea eaulet, but which ought to he placed among the centroponjmcs, beside the lalrax* The bladder of this fish, unique of its kind, will be pre- sented to the Institute alnr.g with a description by M. I^u- vernoy, and which will be njore n)inute tiian any Intherto given under less advantageous circuuistanccs. In \\\s analysis of the air coniaincd iu the bladder, M» Delaroche on the Alr-lladder of Fishes. S99 Delaroche confirms in general the experiments of M. Biot; adding, that besides the varions decrees of depth at which fishes hve, there are other causes whieh concur to vary the proportions of the gases in their air-bladders. I'hus, of two fishes caught on the same spot, one has given 50*0 and the other scarcely 40 of oxygen. M. Delaroche also rec- tifies the idea that M. Biot had civen of the eruption of the bladder fruin ihe moulh, in fishes drawn up suddenly ironi great depths, when he says that a rupture of the blad- der then takes place, and that it is the air which forces up the stoniaci) to the mouth. As to the source of this air, -fuir authoF- (like Needham, Perrault, Monro. Koehlreuter, Duvernoy and Cuvier,) thinks it is produced in the interior oi' the bladder by a secretion of an unknown nature, of which tl)e red bodies seem to be the organs in such fishes as have these bodies. It is unnecessary to ask for a proof of this opinion in fishes which have no exterior canal, for in them it is de^ nionstrated by itself. We might also fairly extend it to those which have a canal and red bodies, like the eel. But in those which want the red bodies, as we mnst admit a new kind of exhalation, the analogy no longer takes place completely ; and perhaps many persons would be equally willing to have recourse to the aerial canal, in so much as it always exists in this description of fishes. As fishes of the same family frequently have the air-bladder, and others want it, it is probable that its functions may be supplied by different means. M. Delaroche, without considering that question as at all decided, nevertheless supports the argument of analog}', from the difliculty which any given gas would have in many «5pecies, in penetrating into the bladder by the canal ; from the still greater dlfiiculty which it would have of arriving pure, particularly when it was requisite for it to pass through * koyd! Societi/. sim trines which consiltnte the theory of ihe science. The hwg of cheniical action, which befall all bodies comprehended midiT the chemical domain of nature, have been detailed in the synthetic form oF propositions — the natural history of the most cljaraeteristic bodies stated — the processes em- ployed in the laboratory for obtaining them, described — and their physical and chemical attributes pointed out, so a« to interest the mind, and llx the doctrines in the memory/* ^_ ■ — ■ \,- . .^ . , LT. Proceedings of Learned Societies, KOYAL SOCIETY. IVIarch 28. — The President in the chair. A letter from Mr. Groombridge to the Astronomer Royal was read on the refraction of light. The author determines the mean as'tronomical refractions from the observations of fifty circumpolar stars ; as also from the zenith distance of the Sim at the solstices. The quantity he assumes at 45^ is 56^''; and this is corrected by the ditference of the errors of the co-latitude thence found. The mean refraction at 45° the author states to be 38-107'' X tang, zenith di- stance, — 3 times the refraction. He then corrects the formula of Bradley, by comparing the mean refraction of the pole star with star's at low altitudes ; whence he deter- mines the refraction from the zenith to the horizon to be 58*1 19" X tang 2 — 3*36 r, and which he shows to agree with the new French tables, by a more simple formula than that of M. de la Place. The author also proposes a ci^ircction for the thermometer, drawn from his observa- tions; something differing from that of Dr. Bradley. April 4.— A letter fronfMr. Brinckley oF Dublin to the Astronomer Royal was read, stating the discovery of the parallax of the annual orbit oF 13 circumpolar stars, which he has found to be 2 f seconds: he also ascertained their refraction somewhat similar to that of Mr. Groombridge, The letter concluded by saying, that the writer is pursuini^ his researches in order to verify the discovery here an- nounced. Some observations on the gizzards of swans, geesq, and herbivorous Fowls, compared with those of turkeys, were communicated by xMr. Home. They consisted oF" a brief description of the process of mastication and digestion in ruminating animals, by chewint^ their food slightly, then swallgwing it afterwards, bringing it up in round balls, mixing, 304 Society of Antiquaries of London . mixing them with saliva, and finally passing them to the fourth stomach, there to be digested. The process of di- gesiion in iicesc and swans is extremely slow, as it is ef- fected bv ihc action solely of the niuscles of their stomachs. Mr. Home examined the structure of their stomachs by filling ihcm with plaister of Paris, and boiling them ; when they appeared composed of straight muscles united by fila- Uients, as observed by Spallanjsani. April 11. — A part of a curious paper by Mr. Macartney on luminous animals was read. Mr. M. took a brief review of the different creatures in the animal kingdom which e'mit light, whether in or out of the sea, as the lampyris, fulgora, &c. He examined minutely the assertions of some French naturalists, who maintain that conmion earth worms have occasionally appeared luminous, and proved that they are unfounded. The luminous appearances in the sea, which have been so often noticed, and yet so imperfectly explained, were next discussed ; and also how far it is probable that the emission of light depends on the will of the insect 5 and whether nature has given this faculty to females in order to attract the males to them, as has been alleged. The reading of ihe remainder of this paper was postponed till next meeting, and the society adjourned till the 3d of May. SOCIETY OF ANTIQUARIHS. Monday, April 23, being St. George's Day, the Society of Antiquaries met at their apartments in Somerset-place, in pursuance of their statutes and charter of incorporation, to elect a president, council, and officers, of the society for the year ensuing : whereupon The most noble George, marquis of Townshend and ear! of Leicester, F. A. Barnard, esq. William Hamilton, esq. W. Bray, esq. Samuel Lysons, esq. Nich. Carlisle, esq. Craven Ord, esq. Sir H. C. Englelield, hart. Matthew Raper, esq. Anthony Hamilton, D. D. Joseph Windham, esq. Eleven of the council were re-chosen of the new council f and Charles Baratty, esq. JLdward Jerningham, esq. Right Hon. P. R. Carcw, Charles duke o"f Norfolk, William, lord bishop of Cloyne, John Towneley, esq. Henry Ellis, esq. Brig. -gen. T. H. Turner, Henry viscount Harberton, Key. Stephen Weston, len / Society for the Encouragement of Arts ^ &c, SOS Ten of the other members of the society, were chosen of the new council, and they were severally declared tQ be the council for the year ensuing ; and on a report made of the officers of the society, it appeared that the most no- ble George marquis of Townshend and earl of Leicester was elected president, William Bray, esq., treasurer, Mat- thew Raper, esq, director, rev. T. W. Wrighte, A. M. se- cretary, and Nicholas Carlisle, esq. secretary for the year ensuing. The society afterwards dined together at the Crown and Anchor tavern in the Strand, according to annual custom, SOClEXy FOR THE ENCOURAGEMENT OF ARTS, &C. At a late meeting of this society a premium of fifty gui- neas was awarded to Mr. John Davis of John Street, Spital Fields, for a most ingenious fire-escape, which promises to be of singular use in lessening the number of personal ac- cidents which occur so frequently in this great city in cases of fire. This contrivance consists of a most curious yet sim- ply constructed ladder, or rather three ladders so combined as to admit of their being slid out, like the tubes of a pocket telescope, to the height of from forty to fifty feet if re- quired ; carrying up at the same time a box to receive females, or children, or small valuables, (while the less timid can descend by the ladder). This box, by means of a chain and pulley worked by the people below, descends to the ground ; where being instantly unhooked, another box is sent up while the first is emptying. All this is per- formed in about two minutes. This apparatus is erected on a carriage with four wheels, g feet long and 5 feet wide, furnished with the usual apparatus and harness for yoking a horse to it, for the more speedy removal to the scene cj danger. The fire offices, much to their credit, assisted the inven- tor with money to construct a machine of this kind for real use, after having inspected his model. We have examined the machine, witnessed the facility with which it performs the destined operation, and we have no hesitation in re- connnending to every parish in London to provide one of them to be kept with their fire ladders and engines. This new fire-escape may be seen at Mr. John Bevan's, , carpenter. City Road, near Finsbury Square. WERNERIAN NATURAL HISTORY SOCIETY. At the meeting of this society on the 10th March, the rev. Dr. Macknight read a paper on the mineralogy of Vol. 35. No. 144. Jpril 1810. U Sirontiaa 80(5 Trench National Institute. Strontian and Ben Nevis, l^lie rocks which compoje the districts of Strontian are mica slate, gni.-iss, and granite ; and the lead-glance, which occurs in gneiss, is associated with iron pyrites, cross-stone, calc-spar, foliated zeolite, strontian, and heavy spar. Ben Nevis is an overlying massive formation, which rests on gneiss and mica-slate, approaching in some places to clay- slate. In this forma- tion compact feldspar is the leading ingredient. The infe- rior mass consists of sienite, passing from the sin)ple gra- nular to the granular porphvritic ; and the npper portion of the mountain, comprehending the summit, with about I'JOO feet of the perpendicular hv'ight below it, is composed of a dark-coloured rock, which, for the most part, is porphy- ritic, and seems to be intimately allied in its characters to compact feldspar. This appears from tlie gradual transition of the one substance into the other, which is distinctly ob- served under the tren>endous precipice of Ben Nevis to the NE. and demonstrates the identity and continuity of the whole formation. The colouring matter appears to be hornblende intimately mixed with the substance of th^ rock. At first view, the whole mass might be considered as a formation of clinkstone and porphyry-slate. But a more minute investigation discovers many oryctognostie characters of distinction from these substances, which are. less crystalline, and belong to a more recent sera of forma- tion . At the same meeting, Df. Arthur Edmonstone read an account of the peculiarities of the Zetland sheep; with re- marks on their diseases. And the secretary read a commu- nication from lieutenant-colonel Imrie, describing a vein pf greenstone, which occurs in Glencoe, and which appears to have been overlooked in the mineralogical descriptions of that district. FRl'NCH NATIONAL INST^TUT^. Analysis of the Lahours of the Class of Mathematical and Physical Sciences of the French Institute^ for the Year All the sciences which are founded upon facts have this distinguished advantage, namely, that every experiment and every observation contribute to their progress. Indeed^ properly speaking, there are no discoveries made in vain, 80 far as the physical sciences are concerned. Whatever • Translated from the original, distributed at the public sitting of the jlass, 2d Jan. 1310. may Prei7c/i Nbiional Instiluie. ^Of in ay be the consequences to which they lead, whatever are the resuUs ol)taiuecl, provided they be just, the instant ihey asiume a character ot" novelty, t;./y beeonie usetul : everv fact has a deierniinate place, uhich can be held by itself alone, and we ought to consider the edifice of the sciences as that of nature: every thing is infinite, every thing ne- cessary. We may go further: in short, the progress oF truth is not essentially retarded because those who devotQ their talents to philosophical subjects occasionally fall into erroneous roads. The most usciul discoveries have sprung from the greatest errors. Wc find the j)roof of this in the labours which have been undertaken to overturn modern chemistry, and to support the old theory of combustion* 'J'he complication of the phjsnomena in this latter science will even I e the cause that the proofs of this description will still continue to be multiplied : facts do not always present themselves imder the same characters; they are {studied under other points of view, they are seen with dif- ferent eyes, and the results' to which they learl are not similar. I'his is precisely the case at present with respect to the discussions which have arisen between Mr. Daw and associates Messrs. Gay Lussac and Thenard. CHEMISTRY. In former reports we have given an account of the dis- covery of Mr. Davy, as to the changes that potash and soda undergo by the action of the Voltaic pile, and of the pro- cesses by which Messrs. Gay Lussac and Thenard produced these changes without the help of the above instrument. Mr. Davy thought that in these experiments the potash and soda were subjected to a deoNygenation, and tliat a true metal resulted from it, which was particularly distin- guished from other substances of this kind by an extreme affinity for oxygen. He called these two nicials potassium and sodium. Messrs. Gay Lussac and Thenard, esta- blished on the contrary, by several experiments, but parti- cularly by the products obtained on analysing the combi- nation of the potassium with ammonia, were of opiihoii that the changes of potash and of soda were owing to a particular combination of these alkalis with hydroo;en» Mr. Davy, having repeated the experiments on whichlhis opinion is founded, has not obtained results conformable to those which had been announced by the French cheniists ; this ha? given rise to sonie observations bv Messrs. Gay Lusfcac and Thenard, in which they show that the dif- ferences found between the results of Mr. Davy's, experi- U 2 njcius >06 P^renck National Institute, ments and their own, appertain to causes which cannot in* fluence the consequences to w hich they have led. To conclude: — On tliher hypothesis, the discovery of Mr. Davy has produced an extremely active re- agent in chemistry, and which must produce, on other bodies, effects hitherto unknown. This new discovery gave rise, therefore, to very different experiments, but which led to the s^me end: some had for their objects to ascertain the action of the pile on the other alkalis, on the earths, and generally on all the simple non-metallic substances which we might suppose to be oxides, like potash and soda. The object of the other? was to decompose, by means of the new metals, substances oxygenized, or supposed to be such, and particularly the boracic, fluoric, and muriatic acids. We informed the public last year, that Messrs. Gay Lussac and Thenard had succeeded in effecting the de- composition of the first of these acids, and had ascertained its radical. Since that time their inquiries have been di- rected to the fluoric acid. They began by studying the physical and chemical pro- perties of this acid more precisely than had been done by any one else. The afiinity of water for this gas is extreme: as soon as it is mixed with other gases which contain some portions of this liquid, abundance of vapours is formed : nevertheless, this gas cannot coijimunicate its expansive force to water ; it cannot be dissolved nor gazify the smallest quantity, and in its aeriform state it is absolutely dry: but it is impossible to obtain this acid pure; it al« ways retains some portions of those bodies with which it has been in contact ; and in the labours which Messrs. Gay Lussac and Thenard have undertaken on the subject of this acid by means of potassiuiT? they made use of si- liceous fluoric gas in preference, as not containing any foreign body susceptible of being decomposed and obscuring the results of the experiments. In the reciprocal action of these two substances, there is a great absorption of fluoric icid, very little hydrogen gas extricated, and a transforma- tiori of the metal int® a solid matter the colour of which i^ reddish browt). ^Jessrs. Gay Lussac and Thenard regard this new com- binatioa as a compound of potash, of silex, and of the ra- dical of the fluoric acid; but they have not been able to obtain this last substance in a separate state. '* It appears," say they, (after several experiments which we cannot give Jjere,) '' that when thjs radical is combined with potash only. French Nalionallnstilufe. 90^ only, it may decompose water like the phosphures; but when it is combined with potash and silex, it does not de- compose it : doubtless, because this triple combination ia insoluble." Mr. Davy has also made attempts to obtain in a free state the fluoric radical, and has obtained results analogous to those above referred to : he ascribes the hydrogen pro- duced in the combination of the potassium with the gas, to the water which he thought was contained in this acid, and which the metal had decomposed. The muriatic acid has also been the subject of numerous and interesting experiments by Mr. Davy and Messrs. Gay Lussac and Thenard. • All three have made some fruitless attempts to dect)mpose this acid, and to insulate the radical which has been considered as forming one of its elements. But Messrs. Gay Lussac and Thenard have ascertained that the nuiriatic acid could not exist without water in the state of gas ; that it then contains one fourth oF its weight; and that water alone possessed the property of taking it up from its dry combinations. Jt nmst be remarked, that in all the experiments made with the metals, the water, on being decomposed, has always produced a quantity of oxide equal to what was required by the acid in order to neu- tralize it ; so that, for every result, hydrogen and a neutral salt were obtained. The limits of this report do tiot admit of our detailing all the experiments made bv Messrs. Gay Lussac and Thenard ; but we ought not to pass over the happy application which these chemists have made, in the decompositions of the nuiriate of soda, ot" the affinity which the muriatic acid has for water. We know that soda enters as a primary matter into several branches ot" manufacture, and it is very important to possess a simple and direct me- thod of extracting this alkali from common salt. As to the oxygenized muriatic acid, Messrs. Gay Lussac and Thenard subjected it to numerous experiments: — " These,'* they inform us, *' ought to give an idea of the constitution of this acid totally diflerent from that which has been formed. It has been regarded as the most easily decomposed body, and on the contrary it resists the action of the most energetic agents. We cannot extract the niuriatic acid from it in the state ot gas, except by means of water or hydrogen." This acid weighs 2*47 more than air. It contains the half of its volume of oxygen gas, and all the water which it can form with the hydrogen is re- tained by the muriatic acid which it contains. This water .makes one fourth qf the weiciht of this last acid. U 3 The ,f 10 Preiich National Instiivte. The acli;>ii or the metal of the potash on the oxltlcs and the inetalhc sahs, and on the eavlhy and alkahne sails, has also been particularly examined bv Messrs. (Jay Lvissac tnd 'I'henard. It results iVoni their inquiries, that all the bodies in which we know (he presence of oxvgen are de- composed by this metal ; that this dccompf)sifion almost always takes place with an extrication ollightand heat ; that this extrication is the more considerable in proportion as the oxvgen is less condensed ; and that, consequently, this might furnish a method of appreciating the degree of con- densation of the oxygen in any body. After having operated on potasli antJ soda, by means of the Voltaic pile, the charges mentioned in the early part of this memoir, it was natural to endeavour to produce analogous efleets on the other alkalis, and on the earths. Jn short, ]\ir. Davy undertook numerous experiments, in order to discover, aceordino- to his svstem, the metals of bnrytes, strontian, lime, magnesia, silcx, alumine, zircon, and glucine. After several fi'uitless eflbrts, he succeeded in de-oxy>:;enizing the first four of these substance^, and in forming amalgams of the new metals which resulted. He thinks that the other four are also metallic oxides ; but his experiments, as he confesses, do not prove this in a satisfactory nianner. Another amalgam produced by an>monia was dis- covered last year, at .Jena, by Dr. Sceheck. This after- wards became the subject of certain researches bv Messrs. Berzclius and Ponlin of Stockholm, and by Mr. Davy in England : all three agree in ascertaining am- monia to be a metal. In the ordinary temperaluje of the atmosphere this amalgam has the consistence of butter, and in the cold it crystallizes in cubes ; but the new metal has not yet been obtained in a separate state. Messrs. Gay I.ussac and Thenard have repeated and proved the correct- ness of the above experiments. But this amalfram, which had been formed by the action of the pile onfy, has been produced by the French chemists by the action of the metal of potash, and they have a>ceriained that a slight agitation was sufficient to decompose it. By this simple actit;n the mercurv once more becomes tluid, and ammonia and hydrogen are liberated in the proportion of 2S to 23. The mercury absorbs 141 times its volume of hydrogen gas, and 88 limes ils volume of anuTjoniacal gas, in order to pass to the state of amalgam : whence it results, according to our authors, that in this combination the mercury in- 'creases about 0*0007 of its weight ; v.hereasj accordin<]: to Mr. French N'aiional Institute. SIX Mr. Davy, it should only increase one I20001I) part. Thus the theory by which Messrs. Gav Lussac and Thenard ex- plain the formation of potassium may be applied to the iormatir)n of ammonium. This new metal, according to them, is nothing but anunonia and hydrogen. b'mally, Mr. Davy has also directed his attention to suU phur, phosphorus, pknnbago, charcoal, and the diamond* The chief experiments relative to these two first substances have been made on hydrogen, sulphuretted and phos- phuretted uases, by means of potassium ; and he concludes, from the results obtained by him, that these two inflam- jnalile bodies are combinations of hydrogen, oxygen, and an unknown base, and which has not yet been obtained in a separate state. As to the other substances, he is inclined to regard plumbago as an alloy of iron with a peculiar metal which is found in charcoal combined with hydrogen, and in the diamond with a small part of oxygen. These ideas were too strongly contradictory of those which are conmionly received, not to excite the inquiries of other chemists. Messrs. Gay Lussac and Thenard therefore made sulphur and phosphorus the subjects of a very extensive series of experiments ; and as Mr. Davy had employed the hydrures in his experiments^ the French chemists in the first place endeavoured to determine the elements of these substances with precision. They ascer- tained that sulphuretted hydrogen gas contains a volume of hvdrogen equal to his quantity ; that the phosphurettcd hydrogen gas contains at least one and a half of its volume ; that the former of these gases may be absorbed by potas- sium and sodium ; and that in this absorption there is de- veloped precisely the same quantity of hydrogen which the metal alone would give with anunonia and with water ; lastly, that phosphureiled hydrogen gas is decomposed by potassium and sodium, so that the phosphorus is combined with this metal, and the hydrogen is set free. But these chemists have not confined their researches to the sub- stances employed by Mr. Davy : they made experiments on arseniated hydrogen gas, and found that this gas acts with I he new metals in the same way with phosphurettcd hydro- gen gas ; and that the metallic arsenic may be combined with hydrogen so as to form a solid hydruret, which has the form of light flakes of a brown colour. They con- cluded that sulphuretted and phosphuretted hydrogen gas, as vvell as sulphur and phosphorus, contain no oxygen, or at least that the experiments of Mr. Davy do not demon- *trate it. They are of opinion, however, as has been al- U 4 ready 312 French National Institute, ready suggested, that sulphur, and perhaps phosphorus, contains hydrogen. We shall not presume to decide between the opinions of Mr. Davy and of Messrs. Gay Lussac and Thenard ; but it will not fail to be remarked, although this cannot lead to any consequence injurious to modern chemistry, that hydrogen, which frequently in the theory of Stahl was nothing else than phlogiston, produces combinations which have all the characters of the metals. In addition to the labours we have mentioned, we are indebted to M. Gay Lussac for some observations on the combination of gaseous substatices with each other, which led him to prove that the gases, in such proportions as to render them fit for combination, always produce com- pounds the elements of which are in very simple ratios with each other. Thus, 100 parts of oxygen gas saturate ex- actly 200 parts of hydrogen ; the fluoric and muriatic gases, mixed with the ammoniacal gas, saturate a volume of the latter equal to their own, and form neutral salts, &c. But he observes, that, when we consider the proportions in weight, we obtain no simple ratio between the elements of a similar combination. Moreover, he shows that the apparent contractions which the gases undergo on combining, also form very simple ratios with the primitive volume of the gases, or only with the volume of one of them ; and he af- terwards makes the remark, that the apparent contraction does not indicate the real contraction which the elements have undergone in combining. These observations have b^-en followed up by a particular inquiry as to the nitrous vapour and nitrous gas considered as a eudiometrical method. Here we see in a very evident manner the influence of the quantities on the result of the combinations. If we mix 200 parts of nitrous gas with 200 parts of oxygen gas, nitric acid is produced; and 100 parts of oxygen remain at liberty. If, on the contrary, wc mix 100 parts of oxygen and 400 of nitrous gas, an ab- sorption of 400 parts takes place, which produces nitrous acid, and 100 parts of nitrous gas remain free. Thus we obtain nitric acid, or nitrous acid, according as either of the gases of which these acids are composed is predominant. But in both cases the absorptions are always constant. Thus, the nitric acid is composed of 100 parts of azotic gas and 200 of oxygen gas, or 100 of oxygen gas and 200 nitrous gas. The nitrous acid results from the combina- tion of 100 parts of oxygen gas and 300 of nitrous gas. And if we add that the nitrous gas is composed of equal parts French National Institute* 3 IS parts of oxygen gas and azotic gas, as M. Gay Lussac had already demonstrated, we shall have a complete history of the combinations of oxygen and azote. M. Guyton de Morveau, in a course of experiments on the diamond and the substances which contain carbon, has endeavoured to determine the action of the diamond on water at a very high temperature. The water was decom- posed, and carbonic acid produced. M. Sage has connnunicated to us his researches on the revivification of silver by mercury in the nitrate of silver; on an acetate oF ammonia, extracted from wood by distilla- tion ; on the analysis of the calcareous stone, called the printing stone; on the magnesia contained in shells, madre- pores, limestone and the arratronite ; on an ore of arena* cemis \xQii 'y on an unknown petrifaction ; and on the ana- lysis of a petrified wood which was both cupreous and fer- ruginous. We regret that our limits do not permit us to enter more into the details of these numerous inquiries. When chemistry descends from crude to organized bodies, the phaenomena which come under its observation are more complex, and the. results obtained more obscure. Thus has this branch of chemistry been neglected until lately ; and most of the observations and discoveries with which it is enriched are undoubtedly owing to the labours of M. Fourcroy, (whose loss we have now to deplore,) and to his distinguished friend M. Vauquelin. This last chemist has lately been occupied with the ana- lysis of tobacco, with a view to ascertain the principles which characterize this plant, and which have recommend- ed it to general use ; and^ finally, with a view to a[)preciate the modifications which it undergoes, in order to prepare it for becoming an article oF commerce. It results, from M. Vauquelin's inquiries, that the broad-leafed tobacco plant (ISlicotiana latifotiaj contains an animal matter of an albuminous nature, some malate of lime, with an excess of acid, acetic acid, nitrate and muriate of potash, a red mat- ter the nature of which is unknown, muriate' of ammo- niac, and, lastly, an acrid and volatile principle, which seems to be different from all those known m the vegetable kingdom. It is this principle which gives to tobacco the qualities which we know it possess ; we may separate it from the plant by distillation, and employ it separately. Prepared tobacco presented more sensibly, than when un- prepared, carbonate of ammonia and muriate of lime. M. Vauquehn, thinking that the juice of bclla donna, from having effects on the animal oecouomy analogous to those 314 French National InstUute* those of tobacco, contained the same acrid principle, pro- ceeded to analyse it; but he found only an animal sub- stance, salts with a base of potash, and a bitter substance; IVom which the juice of the belladonna receives its narco* tic properties. Under the head Physiology, we shall allude to the expe- riments made by M. Vauquelin, on animals^ with ihi^ juice. M. Chevrcul has presented to the class some very exten- sive experiments on vegetable substances. Some have for their objects, the bitter principle produced by the action of the nitric acid on organized bodies which contain azote, and which had already occupied the attention of Messrs. liaussman, Welther, Proust, Fourcroy, and Vauquelin. M. Chevreul thiidcs that this bitter principle is composed of nitric acid and a vegetable oily or resinous substance; and he ascribes the property which this substance has ol* detonating, to the decomposition of nitric acid, to the formation of ammoniacal gas, of prussic acid, and oily hy- drogen gas, &€. This agrees partly with the observations of Slessrs. Fourcroy and Vauquelin. But along with this bitter principle, a resinous matter and a volatile acid are produced, on which M. Chevreul has made various experiments, and which \\2 regards as dif- fering from the bitter principle only in consequence of ita having a small portion of nitric acid. A second inquiry of M. Chevreul has for its object tlie substances formed by the action of the nitric acid on charry or resinous bodies, and which have the property of preci- pitating gelatine. The first observations on this subject were made in England by Mr. Flatchett ; and they in- duced a belief that these substances were analogous to tan- nin. M. Chevreul is of opinion that this is erroneous, and that they differ from each other, not only according to the kind of acid and other substance with vvliicli thev have been prepared, but also according to tlie quantity of 4ic;d vvhicli has entered inj;o their coniposition. Lastly, pursuing alwi^s the same kind of experiments, M. Chevreul directed ^is attention to the difltrent com- pounds formed by the inaction of the sulphuric acid on canq>hor. All the above •researches obtained the appro- bation of the class, and were ordered to be inserted in the Alt' moires des Savans Et rangers. We ouiiht to speak, perhaps, of the supposed discovery made by M. Vinterl, of an earth which he calls andronia, ijul \n which he think? he has found some extraordinary properties; French NationM tnstiinte, S ! ^ properties; and of the memoir of M. Pitaro, in which he tiidcavours to dcmonatratc, that a substance discovered in the Grotto de I'Ar^, and analysed by M. Langier, origi- nates from the deconiposition of the insects and reptiles which this crrolto contains. But there are errors someiimea so palpable,~lhat it is best perhaps to say nothing of them. Every year has added to the store of knowledge we pos- sess on the snbject of the application of chemistry to the arts ; and thus new proofs are afforded of the assistance which our wants, added to our industry, may derive from llie sciences. M. Chaptal, to whom manufacturers are already indebted for so manv useful processes, has published some interest- ing observations on distillation from wines. We find, from the history which he gives of this art, by the descrip- tion of the apparatus f:)rmerly employed, and that of the. present day, that the processes for the production of spirits have been ameliorated in proportion to the improvements in chemical apparatus. One of the most important of these injprovements, adopted in the South of France, consists of scarcely any thing else than the apparatus of Wo u If on a large scale. The laws of evaporation, and the processes by means of which the liquids are heated by steam, have been ingeniously combined, in order to effect the distillation of spirits in an (Economical njanner; but the observations of M. Chaptal will undoubtedly lead to new improve- ments in the preparation of spirits, and will contribute to preserve to this important branch of French trade, the su- j>eriority which it has acquired. The same member has analysed seven specimens of co- lours found at Pompcia, which had been sent to him by the impress Josephine*. M. Sage has been occupied in ascertaining the best pro- jcesses for extracting quicklime, in order to obtain a solid mortar. He has also examined the nature of different . pieces of stucco; the best method of givii^g the polish of marble to artiticial stones ; and, finally, he has given an account of a process for reducing white wax into soap. The san)e author in a memoir, and iNlessrs. Guyton and Vauquelin in a report, have comnumicated some observa-» lions on the advawiages and disadvantages of employing iinc in covering houses !• ^ nd on the request of the minister of the interior, the committee for chemistry has ♦ See Plii!. Ma^, vol. xxxiv. paire 411. f This is not a French discovery, nor is it new. Sec an ingenious paper ¥y Mr. Randall oo this iubjcct in our 'JSth volume, p. 344. — Edit. should 316 French National Institute. shown what arc the descriptions of manufactories which are injurious to the hcahh of the surrounding inhabitants ; and measures have been suggested for removing such as are nuisances, without compromising the interests of the pro- prietors. A report has been made to the Institute on a memoir by M. Tarrv, relative to the composition of writing ink. The author has succeeded in making an ink which cannot be destroved by the acids or alkalies, and which has only the slight inconvenience of allowing its colouring matter to be deposited rather too easily. ** 1 he discovery of M. Tarry," says the reporter, " promises a great benefit to society ; viz. the introduction of an ink, which, not being susceptible of being obliterated by the chemical agents at present known, will put an end to the falsification of writings, which is but too common.'* Another, on the artificial turquoises of M. de Sauviac, gives reason to hope that art will shortly rival nature in these productions, and furnish a new source ot riches. A committee has been busily employed in examining a process of the late M. Bachelier, for the composition of a preservative plaster of Paris. Houses built of stone are (]uickly covered with an earthy coating, of a dirty gray colour ; and this first change is the cause of the deteriora- tion which thev soon atterwards undergo. A sniall kind of spider fixes his web in the hollows on the surface of the stone : these webs accumulate, and, with the dust which they collect, form the earthy crust just mentioned, in, which lichens tsouielimes take root, and which naturally retain a constant humidity at the surface of the stones : the frosts then produce considerable injury, and give occa- sion for those raspings, which are in themselves a real de- terioration. A plaster therefore became a desideratum, which should fill up the inequalities o*^" the stone without making the angles look clumsy, or deadening the carvings, and which should resist rain and other effects of weather. The late AI. Bachelier had made some interesting experiments on this subject ; and the above committee, aided by his son, have succeeded in producing a plaster which has resisted the tests to which they exposed it, and which gives fair C^rouncJs to expect that our buildings will in future be pro- tected from the causes of decay above enumerated. MINERALOGY. Our labours i;i mineralogy will appear inconsiderable in comparidoa De Luc*s Electric Column, 317 tompanson with those of which we have had occasion to give an accouui in former years. M. Guylon has made us acquainted with a new crystal- line form of the diamond. We know that the forms under which it is most frequently presented, are tlie regular octa- hedron and the dodecahedron with rhomboidal faces. The variety discovered by our associate is formed of two demi- sphcroids, the returned position of which, imperfecilv ter- minated at one of its extremities, pre^^ents at the other very clear re- entering angles, which characterize the form called hemitrope by M. Hauy. The same member, having directed his inquiries to the tenacity of metals, was led to some new experiments on the diminution of specific gravity in lead, in consequence of being put into a vice, as proved by Musclienbroek ; and the cause of which remained unknown. Pieces of this metal were dr'.ven into ferules ; and when the dies and the latter were adjusted, so that there could be no oozing out of metal, nor was the lead permitted to become soft, the lead in this case was found, like all the other metals, to in- crease in specific gravity by the operation. M. Sage has communicated to the class his inquiries re- specting emery, and the substances which are calculated to supply its place in polishing. It results from his observa- tions, that the pulverized chrysolite of volcanoes mav supply^ the place of emerv. All the artists who employed it have been satisfied with its effects. [To be continued.] LI I. Intelligence and Miscellaneous A?' tides, DE LUC*S ELECTRIC COLUMN, We learn, by a communication dated 23d April, that the small bells which were connected to De Luc's electric co- lumn^ mentioned in our last number, ceased to ring for about a minute on the 24th March; and again on the same day for about three minutes. They were also supposed to have stopped for about half a minute the next day ; but this is much doubted. Since that tnne they have been known once to cease ringing. On the 15th April, the closet where they are placed was opened, when he clapper was observed to vibrate with very great velocity. It is thought that the loudness of the sound is considerably inert ased of late ; also that the vibrations of the clapper are quicker" than when the apparatus was put into the closet on the 1 4th MarcU. [April 28.] The 318 Lecturer, The cranium of a Iiorned animal, tl'.e race of which seems to be extinct, has been recently dug up at Oeltre, nenr Ninava, in Russia. From the description given of this part of the skeleton, the animal nuist have been at least 10 or 1'2/^1'eet long; the horns which are allaehed to the bead, and which have partly passed into a fossil state, far exceed in size those of the oxen of the present day: when measured at the root, they are a foot and a half in circum- ference, and two feet and a half long. After finding the cranium, several efforts were made to recover the entire skeleton, but two teeth only were found. Foreign natura- lists are of opinion, that the head in question nuist have belonged to the race of Urus or ^^iirocliSy meutioned by CiEsar in the 6th book of his Commentaries, and which are supposed to exist still in the mountains of Siberia^ and even in the forests of Poland. Sir George Mackenzie, accompanied by Mr. Henry Holland, and Mr. Richard Bright, of the university of Edinburgh, has sailed from I.eifh for Stromness ; from whence they are to proceed to Iceland, in a vessel which is expected there from London. The object of this arduous undertaking is to explore part of that inhospitable country, which, without British com- miseration, would, in consequence of the war, be deprived of the absolute necessaries of life. In the circumscribed state of our commerce, this country is very well worth the attention of Great Britain. Fn re- turn for our coarse fabrics, wc might procure such articles as Iceland, under proper management, would afford in great plenty; such as fish, oil, feathers, and sulphur, the scarcity ot which last article has been such as to have al- ready attracted the attention of parliament. MTDICAL AND CHEMICAL LECTURES. Dr. Cluttei^r^'CK will beoin his Summer Course of J^ectures on the Theory and Practice of Physic, Materia Medica, and Chemistry, on Monday, .June the 4th, at a quarter before Ten in the morning, at his hougCj No- I , Crescent, New Bridge Street; where further particulars piay be had. Mr. Taunton will commence his Summer Course of Lectures on Anatomy, Pnysiologv, Pathology, and Sur- gery, on Saturday, May 2f)th, 1810, at 8 o'clock in the evening precisely. The Lectures will be continued every succeeding Tuesday, Thursday, and Saturday^ at the samq hour, until the completion of the Course. \\i the above Course of Lectures it i§ proposed to. take a CQinj^rfe', List of Patents for new Inventions, 3(|^ comprehensive view of the structure and ceconomv of the Jiving body, and to consider the causes, syuiptoms, nature, and treatment of surgical diseases, with the mode of per- forming the dirt'crent surgical operations : forming a com- plete course of anatomical and physiological instruction, tor the medical or surgicial student_, ihe artist, the piofes- sioml or private gentleman. An ample field for professional edification will be aflfordei by the opportunity which pupils may have of attending ihe- clinical and other practice of both the City and Finsbury Dispensaries. Particulars niaybcliad on applying to Mr. Taunton, Grc- ville-Streei, Ilatton Garden. LIST OF PATENTS FOR NEW INVENTIONS. To Frederick Koenig, of Camden Town, in the county of Middlesex, printer, for a method of printing by means of machinery. — March 29, 1810. To Jonathan Kidgway, of Manchester, plumber and glazier, for an improved method for preparing rollers and blocks used for calico printing. — April 6. To John Stanch fie, of Cains College, Cambridge, ba- chelor of physic, for certain improvements in apparatus for combination and condensation of gases and vapours ap- plicable to processes of distillation. — April 6. To John Woodhouse, of Bromsgrove, in the county of Worcester, for several improvements relative to canals. —April fi. '^J'o William Specr, late of the city of Dublin, but now of the citv of Westminster, esq., for a new or improved method or process of increasing the inflammability and combustibility, and of improving the light of oils used for burning, particularly applicable to the oils refined ac- cording to the patent process, wliich will also improve oils refiiied according to the patent process, and oils when used for burning. — April 6, To James Fussel, of Mells, near Frome, in the county of Somerset, iron manufacturer, for a method of making and working foige and other bellows. — April 6. To Charles Fiedeiick Davis, of the parish of Itchcombe, in the county of Gloucester, clothier, for an improvement in the manufacture of woollen cloth. — April 6. To William Parr, of the Portland Hotel, Great Portland Street, in the county of Middlesex, esq., for his improved gunpowder. — April 11. METj:ORO^ 320 Meteorology . METEOROLOGICAL TABLE, Br Mr. Carey, of the Strand, For April 1810. Th ermom etcr. , vy a^ t Days of Month. j2 w P o 8 8 z Hciirht of tlie Baiom. Weather. , 2; Z'z Inches. *- ^ Sl ^e^ c^a ** Q cu. March 27 44 52° 42° 29-59 0 Rain 28 4i 50 40 •78 22 Fair 29 40 51 39 •90 20 Showery 30 40 49 4t2 •85 25 Cloudy 31 43 51 45 •62 0 Showery April 1 43 49 42 •40 0 Showery 2 40 45 40 •72 15 Cloudy 3 43 bQ 46 •60 21 Cloudy 4 45 47 39 •30 0 Rain 5 37 47 45 •69 36 Fair 6 42 45 42 •22 0 Stormy 7 41 53 43 •30 31 Cloudy « 44 51 43 •58 20 Cloudy 9 45 48 44 •45 0 Rain 10 44 42 39 '55 0 Uain U 37 42 36 •65 5 Showerv 12 33 41 34 •90 25 Cloudy' 13 34 42 35 •89 20 Cloudy 14 36 47 39 •81 26 Cloud'y 13 44 49 40 •71 36 Fair 16 39 47 40 •48 10 Showery 17 42 52 45 •64 20 Showery 18 48 56 46 •70 35 Cloudy 19 49 57 47 •80 42 Fair 20 48 57 45 30-10 39 Fair 21 49 59 47 •17 46 Fair 22 50 63 54 •16 40 Fair 23 54 66 55 •20 39 Fair 24 54 63 44 •13 40 Fair 25 44 58 43 •14 57 Fair 26 47 59 45 •12 65 Fair K.B. The Barometer's height is taken atone o'clock. [ 321 ] LIII. Description of an improved apparatus for the De- composition of Potash and Soda. By William Johns, Esq, To Mr. TillocL Sir, J. HE publicity of the Philosophical Magazine in- duces me to transmit for insertion the following account of some successful attempts to repeat the brilliant experi- ments of professor Davy^ in the decomposition of potash and soda, an a more oeconomical plan than has before been suggested*, and which I hope will enable your readers to obtain potassium, &c. for their use at a very moderate ex- pense, I am yours, &c. April 16, 1810. William Johns, No. 3, Orford Row, Kent Road. EaiTLv in the present year, wishing to decompose potass with the bent gun-barrel as is done at the Royal Institution, and not enjoying the ample resources of its excellent che- mical professor; it became a desideratum to construct an apparatus, which might serve for the repetition of the ex- periment, instead of cutting the gun-barrel in pieces, as ia the method before in use, — a practice attended with consi- derable expense, and which could not but check the ardour of^ those who are fond of chemical researches, and prevent the frequent repetition of the experiment : the disappointment resulting from an unsuccessful experiment being always Ttruch heightened when accompanied with the loss of an expensive apparatus. Having succeeded in constructing an apparatus simple and efficient, and which has met the approbation of several eminent chemists, I herewith send you a drawing and de- scription of it. The apparatus consists of a common gun-barrel wTth one bend, and one of the ends inclining downwards a little. The inclining straight part is cut off from the bent portion at about three inches distance, is ground into it, beings made to fit air-tight. Underneath is a small thin iron tube open at both ends, made a little conical, which when the ap- paratus is taken to pieces is placed within the interior of the straight piece, one half of it going into this part; the other will be received in the opposite part, when the apparatus is again put together. This small tube is to collect the potas- ♦ See Phil. Mag. vol. xxxii. p. 276. .Vol, 35, No. 145. May 1810. X slum 322 Dc5criptio7i of an improved Jpparatus^ <^c. sium in, and which purpose it answers exceedingly well, obviating an inconvenience and waste which sometitnes hapj)en From its being dispersed through the barrel. In the first apparatus which I had ci)nsiructed on thii plan, I had the pans made to screw together : tliis answered exrreftiely well, but it po.'^sesscs no advantage over a ground joini, and is more expensive. llie first attempt to use this apparatus, I obtained less than 20 grains of the potassium : this was, however, encou- ragement, my apparatus being in every respect perfect as when I began the process; it served me twelve times very completely, and in the last experiment I collected HO grains of the metalloid from eleven drachms troy of the al- kali. Having succeeded in preserving my apparatus (it at length was melted in a small place, the lute having fallen off in the process), my object was to substitute the conmioii caustic potass instead of the pure potass which had been generally used. I tried it; and to my satisfaction obtained the result just mentioned. At this I was much pleased, the kali purum being sold at one eighth of the price of the pure potass. In my subsequent experiments twelve drachms yielded the extraordinary produce of 170 grains, the apparatus being taken out of the fire entirely free from being acted on. Having attempted the caustic soda alone, and not suc- ceeding with it, J used the proportions of two drachms of soda to six drachms of potass, and obtained CO grains of a beautiful compound nearly fluid, of considerable lustre, and which lustre was inconsiderably diminished some days after ; it nearly floated in the naphtha, being apparently of the same specific gravity. From one p4rt of soda to seven of potass, the proportiori |jsed by Mr. Davy in a similar experiment, I oblaint^d from ten drachms 150 grains of metalloids, in appearance resem- bling quicksilver, equally fluid at a low temperature, though with this striking difTerence, of less specific gravity than some very pure naphtha, in which it floated. The furnace 1 use i? the comtrion black-lead crucible, about eight inches diameter; I generally leave off the upper section as well as the flue. The furnace u^ed at the li*- stitution is, if I do noL mistake, above 20 inches. The double bellows are small in proportion, about 36 inches {ly 14 inches. In performing the experiment, it may be observed in addition to what has bcea said, 1 leave the stopper out of ' try€ I On Vie Camposition and Becomposilion of Forces* 323 the pptas§ tube till ne^r the end of the process, bring it to a red' heaf, before any of the alkali is supplied; then the iron turniuj^s being at a white heat, I introduce pieces of the potass in succession : these arc immediately brought into igneous fusion, adniitting of part of the water contained in it to pass oOT, and in this state it drops down on the iron. When the last portion is introduced, and this also is hocome red hqt, the stopper is put into the tube and luted over. This is all done m less than ten minutes, froni the first supplying of the potass tube with alkali: at th^ other end a glass tube passes down into some olive oil : here the hydrogen escapes, often in a siate of brilliant com- bustion, and potassium deposits in the glass tube : this however should be prevented by wet cloths applied to the straight part of the gun -barrel. Description of the Drawing (Plate IX.) A. Potass tube. B. Stopper to be put in at the end of the process. C. The situation of the iron turnings. D. The fire-place. E. The grate. F. The pipe of the bellows. G. Straight part ground to the bent part. H. Thin iron tube to be placed within the joint, to collect the potassium. I. Glass tube. K. Olive oil. L. Tht part where the gun-barrel begins to decline down- ward. N. B. This inclination should commence precisely at the point where the tube emerges from the furnace, to prevent the potassium from flowing back on the iron turnings. M. Stop-cock screwed into a socket fixed in the gun- barrel, which is shut the moment gas ceases to be given off, and which is known by tlte consequent absorption*. ^IV. On the Composition and Decomposition of Forces, Translated from '' Traitc elcmentaire de Staiique, par Gaspard MoNGEj" by Mr,W» Marrat, of Boston^ Lincolnshire^* \, When a force P, (fi^. 1 and 2,) applied to a deter- Ujiined point .C, of the solid body AB, draws, or pushes * Coramunicated by Mr, Marrat. X 2 this 324 On the Composithn and Decomposition of Threes • this body in any .Hrcction CF ; we inay be permitted tp consider this force as if it were applied to any other point D^ in the body , \\\\\(z\\ is in the direction of this force. For as the several points of the lx)dy which are in the right hne CF can neither approach to\^'ards nor recede from one another, it is evident that no point wha:tever in this line can move without moving all thf, others, in the same manner as if the force were immediately applied to them. We may also be permirtcd to consider the force P as if it were applied to any other point G out of the hody, in the direction of the force, provided that this point be invariably attached to the body. 2. It follows then, that if in the direction of the force P there be found cither in the body a fixed point D, or out of it an immoveable obstacle G, provided that in this lattcf case the obstacle be invariably attached to the body, the force will be destroyed, and the body remain at rest; for we may regard the force as immediately applied to the fixed point, and its effect will be destroyed by the resistance of that point. 3. Reciprocallv, if the force P applied to the body AB Jae destroyed by the resistance of a single fixed point, this point will be found in the direction of the force ; for this point could not destroy the effect of the force unless it opposed the motion of the point of application C, and it could not prevent this motion unless it were in the right line in which the force tends to move the point of applir cation. AXIOMg. I. 4. A point cunnot move several ways at once. 5. Therefore, when several forces diff'erently directed are, applied at the same time to the same point, this point either remains at rest, or it moves in a single direction, in the same manner as if it were moved by a single ibrce in that direction, capable .of producing the same effect. 6. Thus, whatever may be the number and direction of forces applied at the same time to the same point, there always exists a single force which can move it, or which tends to move it, in the same manner as all the forces to- gether. This single force is called the resultant, and the several forces which compose the system, and act all together, are called composants. The operation by which >ve seek the resultant of several given composant forces, • is On the Composition and Decomposition of Forces, 325 is called the composition op forces, and that by which we find the composants when we know the resuhant, i$ called the decomposition of forces*. II. 7. Two forces equal and directly opposite, applied at the same time to the same point, destroy each other and are in equUihrio. Reciprocally, when two forces are in equili- brio, they are equal and directly opposite. 8. If, therefore, several forces differently directed are applied to the same point, to produce an equilibrium, that is to destroy the effect of their resultant, we must apply to this point a single force equal to their resultant, and di- rectly opposite to it; or else we must apply several forces the resultant of which may be equal and directly opposite to the resultant of the first. 9. Reciprocally, when several forces, differently directed/ ^nd applied to the same point, are in equilibrio, their re- sultant is nothing, or, which comes to the same, any one of these forces is equal and directly opposite to the result- ant of all the others, or lastly the resultant of any number, of forces is equal and directly opposite to the resultant of all the others. ;.:.,,;,; m. 10. If several forces applied to the same point have all the same direction, and all act the same way, the effect produced upon this point is the same as would be produced by a single force equal to their sum, acting the same way^ and in the same direction 5 consequently this single force i^ their resultant. 11. Hence, to produce an equilibrium with all these forces, we must apply to the same point, and in an oppo- site direction, a force equal to their sum; for this force will be equal and directly opposite to their resultant. 12. It follows then, First, that when two unequal forces are applied to the same point, but in opposite di- rections, the resultant will be in the direction of the greater, and equal to their difference. For the greater of these twd forces may be considered as coniposed of two forces, di- rected the same way, one of which is equal to the less and the other equal to their difference ; now of these two latter forces, the first is destroyed by the less (7) ; therefore, there remains to move the point, only the difference, which acts in the same direction as the greater. 13. Secondly, That if ever so many forces be applied to the same point, some of which act one way and the * English author* call thi» resoluliijn of forces, X 3 0th CTJ} S26 On the Composition and Decomposition of Forces, 6lbers the contrary; after having found the smli of all those which act one way, and also the smn of all those which act the contrary way, the resuhant of all these forces is equal to the difference of these sums, and is directed the same way as the greater. 14. Therefore, to produce an equilibrium with all thestf forces, we must apply to the same point, and in the di-» rection of the less sum, a force equal to the difference of the sums. For this force will be equal and directly oppo- site tatheir resultant. THEOREM. 15. If to the extrt^tnities off dn inflexible right line AB, (fig. 3) two equal forces P, O, be applied, both of which ^ct the same way, and the directi'orts of which AP, BO, are parallel to each other : 1. The direction of the resultant R of these forces is pa- rallel to AP, BO, and passes through the middle of AB. 2. The resultant is equal to thelipm P+Q of .jhese twd forces. ^..;^) h.in «£-n.>^ .•^•:.r...ii '^ Demonstration of Tf^HE iftks^ Part, li^t anothet' inflexible right line DE perpendicular to the direction of the forces be invariably attached to the right line AB, and produce the direction of the forces P, Q, till they meet the tight line DE in D and E; we may consider these forced as applied at D and E. Divide DE into two equal parts in C, and on that side to which the forces tend to move this right line place an im- moveable obstacle at C, and the right line ED will be ct rest 3 for, the parts of the line on each side of the obstacle being equal, there is no reason why one of these equal forces should overcome the other; therefore the resultant will he destroyed by the obstacle C, or the resultant will pass through the point C. In the same manner it may b4 shown that the direction of the resultant of the two forces passes through I, the middle of any other right line GH parallel to DE. Therefore, it passes at the same time through the two points C, T, which are equally distant from the direction of the forces P, Q, of course it is parallel to them, and passes also through the middle of AB. Part II. The direction of the two forces P, Q, and that of their resultant R, being parallel, we may consider them as concurring in a point at au infinite distance, and the two forces P, Q, as both applied to this point: now thcx resultant of two force*! apjiiied to the sair.e point is equal to their-sum (10): therefore tlie resultant of the two forces 1*. O. is equal to the sum P-f Q of those forces. '^^^^ ^ 16, Cor. On ilie Composition and Decomposition (f Forces, Sf 7 1(5. Co^, J .. To prodiTce an equilibrium with the forces Sfi8 On the €o?npositton and Decomposition of Forces, coniposants, and is equal to their sum: therefore, the re- sultant of the forces P, Q, is equal to their sum, and its direction, which passes throu";h C, is parallel to BQ or A P. 2. The right line AB bemg the half of EF, we have AB=EC, and by subtracting from each of these equal quantities thc»part AC, which is common, vve have BCx= EA=AD. Also, because AB=CF, by taking away the common part CB, we have AC = BF=BD, and because, bv suppo- sition, P I O : : AD : DB, we shall have P : Q : : BC : AC. But the resultant of the two forces P,Q, has been proved to pass through C : hence the point of application of this resultant divides the right line AB into two parts which are reciprocally proportional to the two forces. 19. Cor, 1. Therefore, to produce an equilibrium with the two forces P, Q, we must divide the right line AB in C, so that the two parts may be reciprocally proportional to these two forces, and apply to the point C a third force equal to the sum P-fO, in a contrary direction but parallel to AP or BQ. 20. Remark, If the relation of the forces P, O, and the length of the right line AB be given in numbers, and we want to determine the distance of the point C from A or B, the proportion P:Q::BC:AC cannot be immediately applied, because in this proportion we only know the two first terms : but since P ; O : : BG : AC, by composition P+g : Q : : BC-hAC=AB : AC; also P + Q: P: : AB :BC; in each of which the three first terms are given. 21. Cor,^, When a single force R is applied to a poii^t C, in the inflexible right line AB, we can always resolve it into two others P, Q, which being applied to the two given points A, B, and directed parallel to RC, will pro- duce the same effect; for the force R may be divided into two parts which are reciprocally proportional to the line AC, BC, by means of the two following proportions AB : BC : : R : P AB : AC : : R : O. In each of which we know the three first terms. And the resultant of the two forces P, Q, has the same quantity and direction, imd acts the same way as the force R. 22. Cor. 3. Every thing being (in fig. 5) as in the pre- ceding corollary, if wc apply to the point C, of the right lin« On tJie Composition und Decomposition of Forces, 32t) line AB, a force S equal and directly opposite to the re- sultant of the two forces P, O, in such a manner that S = R = P + Q; the three forces P, Q, S, will be in equilibrio (19), and either of the two forces P, g, may be regarded '■'^* SoLUTroN. Take any two of the forces, as P, Q, ai^rj determine (SO) their resuhant T ; ibis resultant \Vdl be equal to P ; O. and its direction will be parallel to tha't of the two forces P, Q, and we find its point of aj^plication E by the lollowing proportion, P-f O : g : : AB : AE. Instead now of the two forces P and O we may substitute their resuhant T, and having dmwn the light line EC, we must determine the resultant V of the two forces T, R ; this resultant V will also be that of the three forces P, Q, R; its quantity equal to T-l R or =P + 04-R, and it's point of application F will be found bv this proportion, T + K or P4Q + R : R : : EC : EF. Instead of the three forces P, O, R, we may now subst?- tivte their resultant V, and after having drawn the right line FD, we must find the resultant X of the two forces V, S ; this resuhant X will be that of the four forces P. Q, R, S, and its quantity equal P-fOH-R + S ; and we delere- mine upon FD its point of application G, by the propor- tion, V+S or P + O-f R-fS : S : : FD : FG. In the satTie manner we may proceed for any numbei- of forces whatever, and the quantity of the last resuhant will- be equal to the sum of all the forces in t^e system. 26. Cor. 1 . Henccy by supposing that the point G is invariably connected to the points A, B, C, D . . . we shall have an equilibrium with all the forces P, O, R, S . . . by applying to the point G a force, the direction of which is parallel lo that of the original forces, which acts the contra- ry way, and which is equal to their sum P-f Q + Rh-S . . .v ' 27. Cor. 2. If among the forces P, Q, iC^, . , . the and, consequently, the force which, if applied in a contrary direction, would keep the whole in equilibrio. The ge^ neral resuhant being equal to the difference between th* two On the Composition and Decomposidon of Foi'ces. 331 two particular resultants (22), and each of these being equal to the sum of those which compose it (25), it fol- lows that the general resultant is ecjuai to the excess of the sum of the forces which act one way, above the sum of the forces which act the contrary way. 2S. Cor. 3. If the forces P, g, R,'S remain parallel among themselves, and without changing in quantity, tak6 ?4)other direction, and become/?, q^ r, .9, . . . ., the resultant t of the two first will still pass through E and be equal to their sum p + ^. Likewise thtr resultant v of the three forces p, q^ r passes through the point F, and is equal to p + g-^r, Ii) the same manner the resultant r of the fo^f forces p, q, ^, s will pass through the point G and will be eqtial fo the isum p -{-q + r-^s. Hence the general resultarit of all the forces pj y, r, s . . will alwa^'S pass through the same point as the genera(ttesaltint of the first foi*cfes:PiQ', H, S, &c.... •■-;>•' .*'" '■' • , We see then that when the qiiantities and the points of application of parallel forces remain the same, the resultant of these forces always passes through the same point what* ever may be their direction, and the qo-lntiiy of this re- sultant is always equal to their surfj.* * '' '" ■ ' The point through which the resultant of parallel forces always passes, whatever may be their direction^ is called the centre of parallel fen' ccs. It is easy to perceive that if the points of application A, B, C, D, . . . of the parallel forces P, O, R, S . . . .are in the same plane, the centre of these forces is in the same plane; for this plane contains the right line AB, and con- sequently the point E in this right line, which is the centre of the forces P, Q ; it contains als'o the right line EC, and of course it contain? the centre F of the forces P, Q, R: it also contains the right hue FD, and consequently it con- tains the centre G of the forces P, Q, R, S ; atnd so on. J f the points of application are in the same right line, we can demonstrate in the san:e manner that the centre of parallel forces is in the same right line. THEOREM. 29. Two forces applied to the satne body cannot have a resultant, unless their directions concur in the same jpornt, and are contained in the same plane. Demonstration. When the directions of two forces i3o not concur in the same point, they cannot be considered as destined to inove a single point; therefore a single force cannot produce the same eilect, and consequently they have iio resultant. thkokiim. 332 On the Composition and Decomposition of Forces^ THEOREM. 30. If the directions of two forces P, Q, applied to two points A, B, (fig. 7 and 8) of the same body, are contained in the same plane and concur in a certain point D : Istly. The direction of the resultant of these forces will pass through the point of concourse D ; sdly. The direction of the resultant is in the same plauc .as the two forces P, Q, which are its composants. Demonstration of I. The point D being found in the direction of both the forces, if we suppose that thi* point is connected to the body in an invariable manner, we may consider the two forces P, Q, instead of being ap- plied to the points A, B, as applied to the point D, and that tiiey have no other cflect than a tendency to move this point; therefore, their resultant may also be consi- dered as having no other eifect. Now a single force can- not net upon a isingle point unless it be immediately applied to this point. Therefore the resultant of the two forces \*, Q, may be regarded as appiied to this point. Hence, the direction of this force passes through the point of con- course of its two composants. Demonstkatiojs of the 2D. If at the two points of application A, 13, we conceive an inflexible right line to be attached, in an invariable manner, the effect of the two forces PjQ, and consequently that of their resuhant, is evi- dently a tendencv to niove the right line AB. Now a single force cannot move a right line unless it be immediately applied to some point in this line. Therefore, the resultant of the two forces P, Q, may be considered as applied to some point in the right line AB. Hence the direction of this force passes at the same time thrfi)ugh the point D, and also through a point in the right line AB j it is therefore comprised in the plane of the triangle ABD, determined by the directions of the two composants P, g. 31. Cor. It follows then that if three forces P,Q, R, applied to the same body, are in equilibrio among them- selves, the directions of these three forces concur in the same point D, and arc comprised in the same plane. For these three forces being in equilibrio, any one of them is equal and directly opposite to the resultant of the other two; consequently any two of these forces have a resultant; therefore, (29) the directions of these two force* are comprised i^i the same plane, and concur in the sam© point ; and the direction (30) of the resultant of these twa forces, and conse^^uently that of the third force which keeps- On the Composition and Decomposition of Farces, 333 kfeps them in equilibrio, passes through the point of con- course, and is comprised in the plane determined by their tlircctions. LEMMA. 32. If a power P he applied to the circumference of a circle moveable about its centre A (fig. 9), according to the direction BP, which is a tangent to the circle at the point B ; this power has the same tendency to turn the circle about its centre, as if it were applied to any other point C^ and in the direction CQ, which is also a tangent at the point C. THEORE^f• 33. When the directions of two forces P, Q, are in tht same plane, and concur in the same point A (%. 10), if we take upon these directions the right lines Af], AC^ pro- portional to these forces, in such a manner that P:Q: : AB : AC; and having completed the parallelogram AB DC; the direction of the resultant of these two forces will be ac- cording to the diagonal AD of the parallelogram. Demonstration. Conceive for a moment that the point D is an immoveable obstacle, and from this print upon the directions of the two forces let fall the perpendi- culars DE, DF;. the triangles BED, CFD are similar, because the angles at B and C being each of them equal to the angle A, are equal to each other; therefore we have DC:DB::DF:DE; & by the supposition P : Q : : AB : AC or : : DC : DB j^' therefore, P : O : : DF : DE. From the point D as a centre, with the radius DF, de- scribe the circular arc FG, meeting ED produced in G; tlien, regarding this arc and the right line EG as inflexible lines invariably connected to the point A ; conceive that the force P is applied at E, in the direction EP, and that a force M, equal to the force O, is applied to the point G, in a direction parallel to AP, and consequently in the direc- tion of a tangent to the arc FG ; and because the force M=Q, and DF=DG, we have P : M : : DG : DE. Therefore (I8) the resultant of the two parallel force* P, M, passes through the fixed point D, and is destroyed by the resistance of this point; also these two forces are in equilibrio about this point. Now the force Q^ the direction of which is a tangent to the arc FG, and which we may regard as being applied to the $$4 On the Composliion and Dccowposition of Forces* the point F of its direction, tends to turn this arc in the eamc manner as the force M (32), and may be substituted for it in order to counterbalance the force P : therefore the two forces P, Q, are also in equilibrio about the fixed point P, and their ;;esultant will be destroyed by the resistance of this point, and consequently the direction of this resuhunt will pass through the point D, But we have seen that the resultant of the two forces P, O, passes through the point of concourse A of their dircctioiTS (30) ; therefore this resultant will be directed according to the diagonal AD. 34. Cor. 1. If from any point D taken in the direction AD oF the resultant of two forces P, Q, we draw the right lines DB, DC, parallel to the directions of these forces, we shall have a parallelogram A BCD, the sides of which AB, AC, are proportional to the forces P, Q; that is, we shail have P : Q : : AB : AC or : : DC : DB. For if these sides are not proportional to the forces, their resultant will be directed according to the diagonal of the parallelogram, the sides of which are proportional to these forces (33), and not according to ADj which is contrary to the supposition. 35. Cor, 2. If from the point D, taken npon the di- rection AD of the resultant of two forces P, Q, we let fall tlie perpendiculars DE, DF, upon the directions of these forces ; these perpendiculars will be reciprocally propor- tional to the forces P, Q. For it has been shown above (34) that P : O : : DC : DB j and the triangles DBE, DCF, being similar, give DC :DB : : DFrDE^ therefoFe P : Q : : DF : DE. THEOREM. 36. When the directions, of two forces P, Q, are com-^ prised in the same plane, and concur in a point A (fig. 11); if we take upcn these directions the right lines AB, AC, proportional to these forces, in such a manner that we havt: P;Q::AB:AC; and having finished the parallelogram AB DC; the rei- sullant R of these two iorces will be represented in quantity ind direction by the diagonal AD of the parallelogram ; thatift, we shall h^ve ,. V > / P : Q : R : ; AB : AC : ADi Df.monstration. We have already seen (33) that the resultant of tb^e tw(i ibrces P, Q, will be directed according to the diagonal AJi) bf the parallelogram; il therefore re- mains. On the Composition i abolished, in order to make room for this new establish- ment. Every telegraph consists of one upright post, to which are attached three arms exactly similar to each other, moving each upon its own distinct spindle or axis. The axis of one of these arms is near the head of the post. The distance from the centre of motion of each of the two up- permost arms to that of the one imrtiediately below it, is rather less than double the length oi' one arm. The highest of the three arms (A) can exhibit seven distinct positions, but the other two arms (B and C) can only ex- hibit six positions each. The total number of combiuH- tions, or of distinct signals, which can be made by this • Communicated by Capt. P.nsley. y 2 tdegraph, 340 Description of the French Telegraphs tfiegraph, will consequently be three hundred and ninety- one*. As only three bodies are cmplewed in the French telegraph, it may therefore appear superior to the Admiraliv telegraphs used in England, which by the combination of double that number of bodies caw only make sixty-three distinct signals, The meclianisni of the French telegraphs just described, must either be imperfect, or the men employed in working them must have been very unskilful, for the signals were made and repeated in an awkward manner, wiih, what seemed to me, much unnecessary loss of time; but these defects, it will be evident, detract nothing from its merit as an invention. In regard to the mechanical construction, I could only ob.-erve that the arms, which are painted black, and appear solid at a distance, are made in the fashion of a Venetian blind, in order, it may be presumed, to di- minish the action of the wind in bad weather. Each arm has a counterpoise of thin materials painted, white, which, unless the observer is very near the telegraph, becomes in- visible. In the annexed Plate, fig. 1 shows the telegraph in a state of rest, the dotted lines marking the several positions in which the arms can be exhibiied. Figs. 2 and 3 are a specimen of the telegraph at work. Fig. 4 sho^vs the construction of one of the arms on a larger scale, DE being the part which is fashioned like a Venetian blind, and EF the counterpoise. From the above descriptiou it will appear, that the French have adopted, in the arms of their new telegraph, the same principle of motion used in the polygrammalic telegraph invented by me, of which an account is contained in the xxixth volun)e of this work ; the only difference being, that in my telegraph two arms are placed on the same axis, instead of one, to whicli they have confined themselves. Instead of using several posts, which appeared to me the most eligible mode, a polygrammatic telegraph may also be constructed upon one post. Fig. 5 shows how^ this may be done, on comparison of which with my former invention, (fig 6,) it will be seen that the same signals can in some cases be nicule by both. The disadvantage attending a polygrammatic telegraph • A naval officer who ha« been lately employed in the Mediterratrtan informs me, that he doca not believe that the arm A is ever shown ifi its fourth position. I thmk 1 have seen it myseU' in that position, but am not certain. If the French confine themselves to only six positions upon that arm, the total number of signals will be reduced from 391 to 34'i. constructed Description of the French Telegraphs, 341 constructed upon one post instead of several, is, that in the former the combinations are more hmited in num» her. The signal made at A in fig. 5, for instance, can- not be made" cither at B, C, or D in the same figure, ahhough it may be made on all the posts A, B, Cand D in fig. 6. Hence, wliilst each post in fig. 6 can make twenty-eight distinct signals, that niunber in fig. 5 is li» niited to the part A alone, the signals that may be made at B, C or D, in fig 5, being only twenty-one. A polygram matic telegraph upon one post, on the prin- ciple shown in fig 5^ may be thought, however, sufficiently powerful and copious. If four pair ot arms are used, the. total number of di- stinct signals that may be made by the parts A, B, C and D con)bined, will he no less than 308,791 If only three pair of arms are used, in whi:;h case the upper part ot the telegraph niay be supposed cut off at the letter B in fig. 5, the number of distinct signals that may be made by this kind of telegraph (by the various com- binations upon the parts B, C and D) will be 13,935. If we suppose all the upper part of the telegraph to be cut off a little above the letter C in fig. 5, so that only two pair of arms are used, the number of distinct signals that may be made by this telegraph (by the combinations upon the parts C and D alone) will be 637. Hence, even in this reduced state, ' my polygrammatic telegraph, whether constructed upon one or upon two posts, will preserve a considerable superiority over the French as well as over the British Admiralty telegraphs; and it may perhaps be allowed, that, in all cases, it will be perfectly clear, and as little liable to mistake, as any other telegraph that has been invented. A disadvantage attends the polygrammatic telegraph upon four posts, in the form in which it was originally published (fig, 6), arising from the great space upon which the posts must stand ; so that, if the arms are supposed to be six feet long, (measuring from their centre of motion,) the distance AD in that figure can hardly be less than forty feet. This disadvantage will be done away by making the posts of unequal freights, in the manner shown in fig. 7. By this method, the arms being still sup- posed «ix feel long, the distance AD may be reduced to twenty-two feet; so that the telegraph may be conveniently (itted to the roof of the sm.allest building. C. W. Pasley, Captain Royal Engmeers, Y 3 LVI. On [ 342 ]' LVI. On Crystallography, By M. ITauy. Trnvslaied from the last Paris Edition of his Traitc de Mineralogie. [Continued from p. '277.J OF THE CHARACTERS OF MINERALS. >V E understand by the term characters of a mineral, every thing that can be the subject of an observation proper for making it known. We could not refrain, in treating of the mineralogical methods in the preceding article, from giving an idea of the characters which are the soul of the system. But it is necessary to enter into more extensive details on this important subject. If we consider the characters relative to the various branches of science which furnish them, we must distm- guish them as physical, geometrical, and chemical cha- racters. The physical characters are those the observation of which proouces no remarkable change in the state of the substance which presents them, or with respect to which this change is only a condition necessary for observing an effect which in other respects belongs to physics. Thus the phosphorescence produced by throwing the dust of a mineral upon burning coals, although it occasions an alter- ation in the state of the mineral, wilTbe a physical character, like that which arises from the mutual friction of two pieces of quartz. In cases of this kind, where physics and chemistry are so closely allied that it would be dif- ficult to discern their respective limits; we have had it particularly in view to preserve the analogy of the cha- racters, by bringing together those which give rise to ob- Bervations of a similar nature. Properly speaking, we ought to denominate as geome- trical characters those only which are drawn from the de- termination of the primitive fornis, and from the measure- ment of the angles which form by their meeting the faces of the crystals and the sides of these same faces. But we have thought it right to give to this chari^^cter a greater extent than that which seems to agree with it when we take it in a rigorous sense, and to include within it every thing which has a reference to the configuration ; such as the aspect of the fracture, w hich sometinies forms con- vexities and concavities, and «ometimcs presents points or asperities, &c. Besides, we consider, independently of this aspect, the direction in which the fracture takes place, >\hich is soiijetimcs longitudinal, 6r parallel to the axis of ■'■■■■'-■ the On Crystallography, 343 the crystals, sometimes transversal, or perpendicular to the same axis, which also tends to rctcr it to the geometrical charactcTS. Perhaps it may be said that it would have been more agreeable to change the word geometrical into another, which would liave mdicated in a looser manner the modifications depending on the configuration. Bu; this word is so well adapted to those of" physical character and che7nical character, that we have preferred preserving it, by explaining tlie signification which it ought to havt in the language ot mineralogy. The chemical characters are those which are proved by the decomposition of a mineral, or a sensible alteration in its nature, or a rupture of aggregation between its molecules. Such are the characters which are drawn from the action of the acids, from fusion wiih or without addition, by the intermedium of the blowpipe, &c. It is from the assemblage of these three orders of cha- racters that the character will be formed which we call specific^ or that which will serve to distinguish all the bodies comprehended within one and the same species. We ought not to be afraid, from the reaspns which we have already given, of multiplying the particular indications of which it is the assemblage, in order to procure the facility of making them serve for mutually verifying each other, or even of substituting the one for the other. But is it not also an inconvenience, that the table of the characters of a mineral is so overloaded, that we are obliged to run over the whole of it without fixing on any thing which can give a precise knowledge of this mineral, and assist the mind in representing it as it were in miniature?' It is with a view to obviate this inconvenience that I have adopted a character which 1 call essential, and which is composed of the smallest possible number of particular characters taken from among those of the species which are proper for distinguishing the latter from all others. Thus the essential of the teltsia consists in its having a specific gravity of about 4, and presenting joints only in a direction perpendicular to the axis of the crystals : — that t)f the cha- basy consists in its dividing into a rhomboid a little obtuse, and it mtlls easily in the -blowpipe : — that of borated mag- nesia consists in the crystals of this mineral being electrical by heat in eight points opposed to each other in pairs; — that of sulphurated molybdenum is to leave metallic traces on paper, and to conmiunicate electricity to resin by fric- tion. The characters which compose what I call essential^ will not be observable in all cases : but it will be always Y 4 correct 344 On Crystallography, correct to say that they belong exclusively to a certain $pecies of mineral, in such a manner that the idea which they originate will be the faithful rejiresentation. The character in question will be placed at the head of those which compose the specific character. It would, perhaps, be pushing the matter too far, to require that it should always distinguish precisely the substance to which it is applied, not only from all those of the same class, but in general from all the minerals. It would seem to be allowable to understand the classical name from its repre- sentative (enoncS)^ in such a way as to form with this name the entire definition of the substance for which ii has been chosen. In this manner \vc define telesia, an earthy sub- stance with a specific gravity of about 4, and which only presents well defined joints perpendicularly to the axis of Its crystals. We shall see, however^ that in a great number of cases the essential character taken by itself gives an ex- dusion to all the minerals different from that which it de- signates. To conclude : — ^I do not flatter myself with having al- ways succeeded in making the best possible <:hoice of the characters which ought to form that which I call essential; and they will be found sometimes a little vague, when they refer to substances of which we have as yet but a slight notion. Time will add to our stock of knowledge, and this will serve to give more edge to those parts of the pic- ture which are too feebly marked in the present state of science. Still, however, this was not enough ; and one of two things may have happened. Either the observer, who wished to determine a mineral, would proceed straight for- ward to the species of which this mineral formed a part, and then he would have nothing else to do but to consult the essential and specific characters, to ascertain that he was right; or, deceived by a false resemblance, he would be led 10 a foreign species. To bring him back to the right path in this last case, we have added, at the end of the specific character, another which we call distinctive, com- posed of the principal differences which may enable us tq pick ■out a mineral froqn among those with which we should be tempted to confound it. We have also placed at the head of each class a general view of the substance^ which it contains, with the enume- ration of the characters, the assemblage of which may serve to distinguish this class from the others ; and we have en- deavoured \o restrict llieSe characters, §o that there may not On Crystallography. 345 not result a picture too much overcharged. Our method being founded on analysis, it is only as it were bv accident that certain divisions suit an assortn)ent of characters which fiiost frequently vary in a resjx!ct quite dift'erent from that to which the combination of the component principles i$ subjected. After all, if we examine the sy^^tcms in which arbitrary terms most prevail, those in which the characters themselves have led the way for the distribution of bodies instead of following it, we shall perceive thiU it will oftea "happen that general divisions are therein clearly circum- scribed. Alntost continually we find substances eirtergmg from the limits within which they were supposed to have been confined. The important pouU is, that the species are well determined ; because, as we have remarked, the number not being considerable, it is much easier to study the system, and to render it always sufficiently present to our minds, to apply it easily as occasion may require, par- ticularly when on the one hand the progress is traced ac- cording to fixed principles, which second the efforts of the memory bv connecting it with the understanding, and when on the other hand the methods which it emplovs for /characterizing the bodies belong lo interesting observations or experiments, which leave upon the mind durable traces of what has once spoken as it were to the eyes. We hav-e collected under one and the same point of view the principal characters which may serve for the description of a mineral, and we have formed ft tabic of them, v^hich will be foimd prefixed to the plates. We have arranged this table according to the methodical order oi the different branches of knowledge to which it refers; this order hav- ing appeared more favourable for assisting us in seizinc; the whole at a glance, and to render it present to the me- piory. VVe shall here subjoin a series of annotations, intended to give a more developed idea of certain characters, or details relative to the method of verifynig those which, in order to become evident, require experiments. These annotations will be followed by several distinct tables, which wilj present successively the indicarion of the specific gravities of minerals reduced to their limits, that of their hardness, the enumeration ot the substaiices which possess double refraction, of those which are electrical by beat, of those which have for their primitive form a rhom- hoi'd, an octahedron, or a solid of another kind. &c. These various tables will serve as a kind of supplement to the ?y$iemj pa|-tic«larly with ;espect to the second class, uhich 346 On Cri/stallographp. which has remained without subdivisions; or rather they wili form by themselves a kiud ot" system, which will have the advantage of midtiplying the points ot" view under whieh minerals n)ay be regarded. AN.NOTA'TIONS KKLATIVl^ TO THE GENKRAL TABLE OF WINEUALOGICAL CHAllACTKRS. Physical cliaructers, 1. Specific gravity^ Lei us stippose a series of bodies of different natures, which h^n'e equal volumes. If we weigh all these bodies successively by means of common scales, it will be necessary, in order to e*labli$h the equili- brium, to employ weights more or less considerable, ac- cording as these bodies are more or less dense. Let us suppose, moreover, that, having taken as a term of com- parison one of these bodies, for instance the lightest, we represent its weight by unity, and we express the weight of all the other bodies by nun)bers proportional to that unity. We shall have the relations between the weights of the diflerent bodies of equal volume, or the specific gravities of these bodies. Bui the hypothesis, that all the bodies of which we would propose to determine the specific gravities have equal volumes, not being capable of being reahzt-d, it will be- come necessary to seek for another method in order to at- tain the same object. We might succeed equally well, were we to estimate exactly the volume oF each body ; after which it would be easy to bring the results of the different weighings to what they would have been on the hypothesis of there having been an unity in the volutTie, But as this method presents obstacles which are insurmountable in practice, we supply its place bv an ingenious process, whieh consists in seeking for the relation between the weight of each body when weighed in the air, and the loss of weight Avhich appears when the same body is weighed in water, which we here suppose to be respectively ligliter than it. This loss proceeds from the eflbrt made by the water to sustain the body in part ; and this effort being equal to that which it exercised in order to keej) in equilibrium the volume of the same liquid displaced by the body, it results that the loss in question represents the weioht of a volume of wa- ter equal to that of the body. We liave therefore the re- lation between the weight of the body and that of the water in equal volumes ; and this liquid thus serves as a common measurement, in order to compare with each Other the specific crravities of the different bodies. It On Crystallography, 347 I( is in this Way that the tables of specific gravities pub- lished bv several authors have been made up. OF these the tabic of M. Brisson is the amplest and the most correct. We employ in these experiments the hydrostatic balance. The body to be examined is suspended by means of a horse- hair to a small hook under one of the scales, which pro- cures the facility of plunging this body into water in order to weigh it. Nicholson has suggested in these experiments the use of an areometer of tinned iron, represented in fig. 75, and the static of which, B, is a brass wire, which has at its ex- tremity a small cistern A. This stalk is marked in the middle by a line h made with a tile. The lower part keeps suspended an inverted cone EG, concave at its base, and balanced within by a piece of lead*. The weight of the instrument ought to be such that, when we plunge it in water and leave it to itself, a part of the tube floats above. The cistern at the top of the stalk, and which has the form of a spherical shell, is fixed to it by means e property possessed by certain substances, and particularly by the metals, of resisting without being broken the action of a force which draws them by one extremity while they are fixed at the opposite extremity. Of this kind is the re- sistance presented to breaking by a harpsichord string which we are tuning. This property is but little susceptible of bein^ employed as a character, but it is right to mention, in the description of a mineral, to what degree it possesses it in comparison with others. 7« Adiitrence to the tongue. Certain bodies adhere to the bnCrystauographtj, 353 the tongue when brought in contact with it, and a slight, resistance is experienced when we separate them. This eflfect is produced by the facuUy which the body has o,f/ absorbing the saliva which moistens the tongue, and thu8r> bringing the substance into more immeiHate contact with this organ. If wc put a drqp of water on one of these bodies, we shall observe that it is imbibed in an instant, and this proof may suffice instead of applying it to the tongue. . ,M,; bov: 'I. 8. Colo2trs, In order to fix the degree of confidence ^ which these characters deserve when borrowed from this nrtodification, too much neglected by some, and overvalued by others, we ought to consider it in two very different points of view, according to the various natures of the bodies which are furnished with it. Tn a certain number of these bodies, and in particular in. the earthy and acidi- ferous substances, the colours are owing; to the molecules of a foreign principle, which is frequently iron, and some- times chrome or manganese, disseminated among the mo- lecules peculiar to the coloured body. Hence it happens that one and the same substance, for example fluated lime> is colourless in certain pieces, and in others presents alter- nately the red, yellow, green, violet, &c. In this case the colour is only a transient accident, which may merely serve to distinguish certain varieties. But in other minerals, such as metallic substances, sul- phur, amber, some saline substances, the reflection of the rays which produce the colour is made upon the proper parts of the coloured body; it depends on its texture and on the degree of the tenuity of its molecules. It may then he ranked among the specific characters. We sometimes find muriaicd soda coloured red. If you dissolve it in this state, it will be stripped of its colouring principle, and the new crystals which it will form will no longer reflect any thing but white light. The operation only frees it from a superfluity, without which it does noti- cease to be of the same nature. On the contrary, sulphated,; copper subjected to the same experiment, as often as we please, will always reappear blue, because this colour i3 inherent in its nature. Thus those who have said that the true colour of the spinel ruby, for instance, was red mixed with orange, have only designated the sione which pleases amateurs most. , But to say that the true colour of gold is pure yellow, is , to speak the language of the naturalist. If this colour does not uniformly exist in gold, this must arise from the pre- Vol, 35, No. 145. May 1810. Z shic« 3i4 On Crystallography, sence of a foreign substance which has altered the metal ifself. I have met with naturalists, however, who, admitting the variations to which the colour is subject, with respect to one part of the minerals, do not warrant us in attaching much importance to the character v^hich it furnishes; as much because it is that which first speaks to the eyes, as because there is always, according to them, relatively to each substance, a colour which is predominant, and which agrees with the greatest niunber of varieties. But the more the observations shall be mukiplied, the more fre- qnenily will it happen that this character will not speak to the eve, except to deceive it and make it take the chancre. No further proof of this is requisite than what happens with respect to the emerald. Grass-green seems long to have been ranged among the general characters of this sub- stance, and, in short, it is not astonishing that every thing which was emerald was of thp same colour. We were not acquainted with any thing else, properly speaking, under this name, than the crystals from Peru, which being form- ed in the same circumstances had received the impression of the same colouring principle. A discovery in which mineralogy and chemistry have concurred, unites the beryl with the emerald ; and from his moment we have emeralds, some greenish-yellow, others blucish, and others of a de- cided yellow; and the number of the crystals of these dif- ferent tints, particularly of the first, which exist in our cot- lectjons, far exceeds the ancrent emeralds. The jargon of Ceylon identified with the hyacinth, according to the analysis of Klaproth, has also disturbed this fast substance in the place it occupied, namely, that of being exhibited of an orange brown colour oidy, excepting in, one variety which was whitish : and it would be as easy to adduce other ex- amples of this kind*, as it is to foresee from the moment that these examples will still continue to be multiphed. The indication of the colour, in the case of the latter being owing to an accessary principle, ought therefore to be dis- missed from the specific character ; and wc shall have a new reason to exclude it, if we consider that every thing * Laiinoy brought from Spain several small orange crystals which be- long-to phosphated lime, known in Germany by the name of spar^el-sfnti, bec^.usetlie colour of tlie variety of this substance found at first in the same country inclines to that of asparagus Messrs. Abildgaard and Mant hey have since given me some crystals of this substance which are ireuuently met wifh in certain granitic roCks of Norway, and the colour of which. is iometimes of a greenish blue, sometimes brown, 6c c which On Cryslallography* 35 i which enters into this character ought to be so much the niore taken into the account, the purer the substance is, or the more it approaches the hmit which really constitutes its species : and that in the case of this limit the colour would disappear*. As to the diversities oF which the character is suscepti- ble that is derived from colours, it would be superfluous to enumerate them, because we find on this head in daily ob- servation, and in the commonly received language, every thing that can be required by science and its nomenclature. Thus, in order to designate any. given shade of colour, sometimes we add a simple adjective ; as when we say pure green, bright red, dark blue : sometimes we refer the colour to a term of comparison taken from among familiar ob- jects ; as when we say sky blue, saffron yellow, leek green, &c. : on other occasions we give the two colours of which the object in question seems to partake, and say, for ex- ample, greenish yellow, or yellowish green, by calling in the predominant colour first. 9. Cat's eye colours. This expression alludes to the eyes of a cat which shine in the dark. We say of a sub- stance that it is cat's eyed, when, in proportion as we vary the position of its surface, the reflections of light which it iiives off are in some measure moveable, or appear and disappear alternately. JO. Metallic lustre. We may distinguish the true from that which is apparent only, in so far as the mark of a file or any sharp instrument with which we have scratched a metal does not cease to shine, whereas it is dirty, and as it were powderv, when the body is not of a metallic nature. 11. Limpid bodies. VVe have given the name oi white to diaphanous and colourless minerals properly so call- ed, such as the (j^w2^x\z Q.d\Wi\ Madagascar crystal. We shall cajl these limpid minerals, and reserve the deno- ♦ We must confess that there would have been some advantage in quot- ing at the head of the description of a Species, the character derived from the modiiication in qaerion, it the j^reater number of the varieties presented cne and the same colour, or nearly so. in such a way that the difffrences which would have taken place in other varieties might have been regarded as exceptions; because, this character being that which first strikes the eye, its indication would tb.eieby be very proper for becoming as if the first stroke of the pencil in giving the portrait of a mineral. But if we are obh'ged to quote :\t onct- eight or ten diflereat colours, which are shajed by various individuals of the species, wiil it not appear that the dcscriptioa commences by falling into absurdity, and by failing in its principal object, which is to admit of a facilitv of ascertaining at one glance the »ubstance indicated ? ' ^ Z 2 mination 3'56 - On Cnjitallography , ininalion of il kite for those which reflect without order the assemhiage of all the colours, like statuary inarhle. 12. Dofthle refraction. When a ray of light passes obliquely from one medium into another of a diHerent den- sity, it is diverted from its route, forminir a kind of fold, Ths deviation, which we call refraction, is subjected to a constant law which is known to all naturalists. ' Certain substances have the singular property to solicit the ray which penetrates them to divide itself into two parts which follow two different routes. This is called doithle refraction. When the refraction is simple, we only perceive a single image of an object seen through two faces of a transparent piece of the mineral employed on this occasion, whereas, if it were doable, we might in the same case see two images of the object. But in order to obtain this eflect with most of the substances endowed with the property in question, we must choose two faces inclined towards each other, whether we employ a crystal giveii by nature or a piec« cut by the lapidary. The quantity of double refraction, or, what comes to the^ same thing, the opening of the angle formed between each other by the rays, by means of which the eye sees the two images, varies froiTi one substance to the other, every thing else being considered according to the nature of the sub- stances themselves. In zircon, for instance, the double refraction is very strong, whereas it is much less percepti- ble in the eitierald. Besides, this quantity varies in every substance, from various causes. In general it increases or diminishes, according as the rcfrangent angle, or that which is formed between each other by the two faces, through which we view objects, is more oy less open. But there is another cause of variation, which is combined with the foregoing, and which depends on the position of the refrangent surfaces relatively to the faces of the pri- mitive form ; and such is the influence of this cause, that under two equal refrangent angles difierently situated, we may have distances evidently unequal between the imao:es of the same object, and there is even a limit at which Fhe effect of the double refraction becomes null, i. e. the two images are then confounded into one. This limit takes place, for instance, in the quartz and in the emerald, when one of the faces which belong to the refrangent angle is perpendicular to the axis. It takes place in sulphated barytes^ when one of the^anie faces being ■^ -parallel On Crystallography* 357 parallel to the axis, is at the same time parallel to a plane which should pass by the great diagonals of the bases of the priniiiive form. T have but a verv few observations ou this subject as yet ; but it is probable that all the substances which have the double refraction fall within one or other bf the fore^goiiig cast-s, which s\vt of themselves the limits 'of all the positions which refrangent surfaces may have relatively to the prin^itive ibrm. But as the position pa- rallel to the axis is variable in its turn among several limits, which correspond with the diagonals and the Fides of the bases of the primitive form, it will be requisite to know which of these last limits is that which agrees with every substance. F shall explain, when I come to the article emerald, how a mistake led me to these results ; and 1 even confess that T am still in uncertainty as to the refraction of some sub« stances, not having had time sufficiently to multiply my inquiries, in order to ascertain if a crys.tal of this de- scription which presented only a single image of the ob- jects, would not exhibit two alter having been cut in a cer^ tain manner. I shall detail, in speaking of every substance, what I have observed with respect to its refraction, and I propose to make some fresh experiments on this delicate point con- nected with minerals, which I have been only able to glance at as yet. We shall find, under the article carbonated lime, the detail of the particular results which [attained re- lative to the double refraction of this acidiferous substance, which suits njore easily than the others this kind of in- quiries. Another observation, which will not be altogether useless when we are occupied with generalizing the theory of the phsenomenon in question, consists in this — namely, that all the substances in which the integrant molecule is re- markable for i'.s symmetry have the simple refraction. Of Ihis kind are those which have for their primitive furm the cube, the regular octahedron and the rhomboidal dodeca- hedron. As yet we have only subjected to the experiments which concern this object, bodies taken from among those which we coinmonlv designate by the name of stones. I have Extended tht^e experiments to several of those which are Called salis^ as well as to inflammable substances, and to metallic substances oxidized and united to other principles, and I have foe. :i 'hat there is no class of minerals w^hicli lioes not present bodies endowed with double refraction. Z 3 There 358 On Crystallography. There are various ways of observing the double refrac- tion. One of the most simple consists in taking a pin by the point, and presenting it against the window at a cer- tain distance from the eye, against which we shall keep At the sanie time the mineral applied bv one of its faces. By making the pin assume various positions, we shall fin^ that there is one in which we see two distinct images of this pin parallel to each other, and generally prismatic (?m%5*). Then, if we gently turn the pin until it is per- pendicular to its first position, we shall see the two images approach by degrees, until they fall upon one and the same line, in such a manner, however, that one of the two heads will frequently exceed the other. We may also m^ke use of a card on which we have traced a line with ink of a good tint. The separation between the images is more sensible, the distance between the object and the eye and all other cir- jcumstances being alike, when the diaphanous body used in the experiment is of a greater thickness. And if we sup- pose this thickness, in its turn, to be constant, and the ob- ject removed from the eye, the two iniages will be more and more removed from each other, at the same time that they will be diminished in distinctness. The following is a third advantageous process for short- sighted people. Place a lighted candle at a certain distance in a dark room. Having afterwards made a hole in a card with the point of a pin, apply it to one of the faces of the stone, so as to make the hole correspond to a point of this face ; then having approached with the eye the ppposite face, seek the position proper for enabling you to perceive the flame of the candle. You wilj then have the two images distinct and well defined, because the effect of the hole made with the pin is to dismiss the kind of irradiation which dazzles them, when we employ the, stone by it- self. : It would be difficult to find a character more prominent than that which is drawn from the double refraction, since it belongs to the very essence of the minerals in which it exists. But ue cannoi always observe it on taking these bodies in the natural state. Several require to be prepare4 • When the double refraction is not ccnsiderahle, it may happen that the two images touch each other. B«it, upon attentively exan\iniug the head of the pin, we can distinguish at this place as it were two small circles which intersect each other : and be^des, we shall observe that the same co- four which edges on one side the prismatic band reappears on the line of the middle part, where the same series reconmicuces. for On Crystallography, 355^ for inspection by cutting. Those which are called gems, ^and which have come through the hands of the artist, tliereby becom<; susceptibht of presenting the effect of ■siniple or double refraction, when we know how to guard against the illusion produced by the multiplicity of tiie fa- cets; and it is even an advantage to be able by ttie help of this multiplicity to vary the refrangent angle, because, if any one of the facets was situated in the direction of the Jimits where the two refactions are reduced to one only, other facets would present themselves in order to dispel the doubt. We shall thus avoid confounding a piece of cry- stal of Madagascar with the gem called by lapidaries while sapphire, their Brazilian ruby with the lalass ruby, the topaz of Saxony with what is called oriental topaz ; the first stone of each of the above pairs having the double re- fraction, while the second has the simple : it is fortunate to be able in these cases to make up for the disappearance of the crystalline forms by a physical observation, and to read in a manner into the interior of the stone,when its ex- terior speaks no longer to the eye. 13. Phosplwrescenoe hy the action of Jive. In order to observe this character, we must throw on red-hot char- coal a small quantity of the dust of the mineral we wish to examine. The phosphorescence in question is not sim- ply a scintiJlation, like what is produced by the sawings of wood thrown upon the flame, but a mild and agreeable light similar to that of the glow-worm, the tone of colour excepted, whie.h varies in different substances. This ex- periment scarcely ever succeeds except in the dark. We must also take great care to pound the mineral well, lest any decrepitation might throw the fragments into the eyes of the by-standers, 14. Electricity, There are three ways of exciting the electrical virtue in bodies ; namely, by friction, by commu- nication with a body already in a state of electricity, or by heat. This last method takes place only with respect to certain mineral substances. We distiniruish two kinds of electricity : the one which we call vitreous^ ajid which Franklin called positive, is that which friction produces in glass ai^ other viireous sub- stances. The second, which we call rennous, and which Franklin described by the name of negative, is that which is acquired in the same case by resin, sulphur, silk, &:c. These two electricities exercise contrary actions ; so that two bodies, both of which are solicited by vitreous electri- city or by resinous electricity, are repelled, whilst two Z 4 bodies 360 On Crystallography . bodies one of which possesses the vitreous and the other the resinous electricity are mutually attracted. Amony: the number of bodies capable of receiving elec- tricity by friction, \vc find some, which, after having been simpfv presented to the fire for a moment, or dipped into hot water, have acquired the electrical virtue. These bodies have in this case one side solicited by vitreous electricity, while the side diametrically opposite gives signs of resinous electricity. One general observation made on such of the same bodies as are crystallized, consists in this ; namely, that their forms take from the symmtlry of the ordinary crystals, in the same manner as the parts in which the two species of elec- tricity reside, although similarly situated on both sides, differ in their configuration. The one undergoes de- crements which are null on the opposite part, or to which some decrements answer which follow another law. It results that on a simple inspection of one of these crystals, U'e may indicate hcTorehand the side which will give signs of vitreous electricity, and th^t which will manifest resinous .electricity. ' Electricity separates the whole mineral kingdom into three great divisions, which follow nearly the methodical order generally adopted for the classification of bodies of this kingdom. Almost all the substances known by the names of stones and salts acquire by friction the vitreous electricity, provided they enjoy a certain *(Jegree of purity. The inflammable substances properly so called, with the exception of the diamond, being rubbed in the same man- ner, receive on the contrary the resinous electricity. The metallic substances possess in general in an eipjnent de- gree the conducting property of electricity. A few of then), which being mineralized approach the saline state^ such as carboriatcd lead, also enter into analogy with the salts, by the facuhy of acquiring the vitreous electricity by means of friction. I ought to premise that we here allude to the ordinary inethods of exciting electricity ; as when we employ the friction of the hand, or that of a piece of cloth. I sup- pose also that the bodies rubbed are polished; for there are some kinds of quartz, gems, and other analogous sub- stances, such as glass, v\hich acquire the resinous electricity by means of friction when its surface is dull. It results from all that has been said, that the electrical property furnishes characters useful in several respects for jtjie distinction of minerals. ' ' Electricity On Crystallography , 361 Electricity by communication, employed alone, may ^erve to discover the presence of a metal mixed in a con- siderable quantity with a sionc, as takes place with the iron which enters into the composition of jaspers. In order to ascertain this character, we insulate ihe sione on a small stalk, so as to bring it in contact with an electrical conductor, and we judge whether the stone is electrical or not by communication, according as the touch of the fin- ger or the ball of the discharger draws sparks from it. The electricity by friction observed comparatively in two different stones may assist in distinguishing them from one another. The cymophane when polished but not cqt^ which presents nearly the same appearance wiih mother-of- pearl feldspar, called moon-stone, ditfers from it by the great facility which it has of being electrified by friction, whereas the same method succeeds but ineiFectually and feebly on feldspar. The simplest apparatus for experiments of this kind consists of a small copper needle a h (fig. 76, A) termi- nated hy two bowls and moveable on a pivot. After hav- ing rubbed the mineral several times on a piece of cloth, we must present it to one of the bowls, and we may judge pretty nearly of the strength of the electricity, by the di- stance at which this bowl bes^ins to be attracted. With respect to substances electrical by heat, such as the tourmaline, we make use of the same apparatus when we merely wish to ascertain what they are. But it is in- teresting to be afterwards able to determine the parts in which the two electricities reside. To effect this lake a stick of sealing-wax, to the extremity of which a silk thread is attached little better than one eighth of one inch in length : after having rubbed this stick, present by turns jhe two opposite sides of the substance, for example, the two summits of a tourmaline, at a small distance frf)m the silk thread. If the summit which faces the thread be the seat of resinous electricity, there will be repulsion. In the contrary case the thread will be attracted. We mav vary this experiment, by placing the stick of wax, after having rubbed it, below one of the two bowls which terminate the needle, at the distance of about a quar- ter of an inch. For the greater simplicity, we may give such a height lo the stand of the needle, that the stick of wax \yhen resiintr by the rubbed extremity on another stick or on a glass tube placed transversely, and by the other ex- .trcmiiy on the table which holds the apparatus, is ar tiie distance 362 On Crystallography, distance required for tlie success of the experiment. In this case, the wax acting on the bowj comrnunicalcs to it an electricitv contrary to its own ; whence it follows that we have inverse cfiecis to the f'oregoino-, f . ^. the side of the stone sohcited by the \ifreous electricitv repels the needle to which we present it, and that which possesses the resinous electricity attracts this needk to it. This niethod is preferable to the first, when the electrical body is very sni;ill, or has but a feeble virtue. Fig. 76 B represents the experiment described. We^ there «Jee the tourmahne //' caught by pincers supposed to J)e held in the haiuis of the observer, in such a way that the pole ^ is at a small distance from the bowl a of the needle. C^ is the stick of wax which rests by one of its extremities on a tube of glass U//, and which ads by its part C on the bowl a, in order to produce the vitreous electricity. In what has gone before wc have considered the effects of the action exercised on a mineral by another body, so that the former may lie regarded as passive with respect to the latter. What we now call active electricity is that which the mineral excites of itself in the sealintr-wax, by means of friction. In order that rhe experiment ir>ay succeed better, we must, after having heated the stick of wax, flatten it at one end by pressing it on a smooth body. We must afterwards rub this same end with a part of the mineral, which is itself smooth, or at least free from aspe- rities ; then we shall present the wax to the copper needle under which we have placed before-hand another electrified stick of wax, as has been already mentioned. Every body, the friction of which thus communicates to wax a certain species of electricity, acquires at the same time the contrary electricity; so that v^e might consider this last electricitv in preference, or, what comes to the same thing, consider the tnineral as being passive with re- spect to tlie wax. But the mineral in which this experi- ment becomes interestins; being conductors of electricity, It is simpler to examine their action upon wax, either be- cause without this expedient we should be obliged to in- sulate them, or because when their vf)lume is somewhat considerable their electricity, by being diflfused over a large surface, would not be sufficiently palpable. VV^e have as yet but a small number of substances which excite the vitreous electricity in wax, whereas other sub- stances of an analogous nature produce in it the contrary electricity^ On Crystallography, 36S electricity. These are exceptions as it were to the ordinary results, susceptible even on that very account of accurately designating: the minerals which present them. 15. Magnetism. We know that two magnetic needle?, when they turn towards each other their north or their south poles, are repelled ; whereas there is an attraction, if the poles facing each other are one of them south and the other north. In consequence we recognize a needle, i,e, a piece of iron in the state of permanent magnetism, from the same side of this piece of iron presented successively to the two poles of a magnetic bar suspended freely, at- tracting the one and repelling the other, or vice versa. But if we employ a piece of common iron, there will be aiiractioniu both cases; the pole nearest the iron will communicate to the part turned towards it a magnetism contrary to its own, so that there will then be two mag- netic needles which will face each other by opposite poles. The magnetism thus acquired is merely instantaneous : it gives place to the contrary magnetism the moment the iron passes from the neighbourhood of one pole to that of the other, and is dissipated tjie instant the iron is no longer in the sphere of activity of the bar. 7n Tex peri ments of this kind it is preferable to use a needle in the form of a lozenge, three or four inches long, instead of a b^r, the former being more sensible. But the bar would be preferable, if it were requisite for instance to pick out some specimens of iron scattered in ^ piilverulent mass. 1 shall shdw under the head of oxidulated iron, that most of the crystals, or even the rude masses of this metal, locked up in the bowels of the earth, provided they are not too much oxidized, are two magnets, but of which we cannot observe the polarity except by using a needle slightly magnetic, and this for a reason which I shall give at the ^ame part of my work. (Tc be continued.] LVII. Account .[ 364 ] LVII. Account of the IVhynn Dykes hi the Kt'ighhourhood of the Giant's Causeway, Batly castle, and Belfast : in a letter to the Lord Bhihup of Droniorc, fro7n William Richardson, D.D» late Fellow of Trinity College, Duhlin^, ^1t Lord, W hen I last had the honour of conversing with you on basalt subjects, you were surprised when I told you that the whynn dyhcs^ whieli of late have so much occupied the attention of naturalists in the western isles of Scotland, originated on our Irish coast, and t'Bpecially about the Giant's Causeway. As your lordship expressed a wish for furtlier informa- tion of the subject, I promised to communicate to you •such observations as J should make when I had examined the coast a second time, in order to ascertain i\\Q facts with the utmost precision. Previous to my entering into a particular account of our dykes, I will take/ the libcrtv of making a few general ob- servations on those in both countries. The whynn dykes in the Hebrides are seen under very iliflferent circumstances fron> those on the northern coast of Ireland, There they are found on, and above, the surface, generally a few feet; and often serve as fences, whence they obtain their najue. In this form they run northwards quite to the extremity of these islands, ascending and de- scending mountains, crossing seas ; and where these are narrow, the dykes that run into the water at one side of a channel, are seen rising out of ii at the other side, steadily pursuing their formed rectilineal course. With us they are sometimes exhibited in a very different manner. Their first appearance is in the faces of our vast perpendicular precipices, where they are seen cutting ver- tically the several strata of which these are composed, and then burying themselves in the northern ocean. The observations made on these whynn dykes in the two countries, taken together, make our information on the subject complete. In the Hebrides we are surprised at the incredible length to which these mighty walls proceed, * Dr. Richardson's paper on the Basaltic Country in the Counties of Derry ane, of spending some time with me at the Giant's Causeway, you will be able to judge for yourself as to the truth of these contradictory assertions. The advocates for igneous operations over the surface of our globe are so prejudiced, that it is sometimes sufficient to refute them merely to quote their own words. As Mr. Mills's paper is now before me, [ will give your lord- ship an instai^ce : He says, (page 98,) '< In short, from the very rude and irregular appearance of the summit of the hill (Loffit hill), from its rising so suddenly from the lime- stone strata, and from the whynn dyke that runs through it, I am strongly inclined to believe it of volcanic origin." Now, as limestone and volcanic matters are not very con- genial, and as we do not find that a whynn dyke has been met with in the neighbourhood of any volcano, I conceive, with great deference to Mr. Mills, that if he was deter- mined to draw a conclusion' from these data, it should have been a contrary one.— But it is time to proceed to facts. The westernmost vvhvnn dyke I have met with on our coast, is near what is called the Black Rock, at the end of the Bush Strand. The perpendicular precipice is there not very high (probably 6() feet) ; it is composed of hori- zontal strata of table basalts, separated from each other by red ochreous layers. The dyke (which is inaccessibTe) i.^ seen from the water- tu cut all these strata rertically, each of them bemg inter- rupted I Neigklourhood cf the Giant's Causeway^ ^c, 367 rupted in its course by this wall, and resumed on the other side ot it, precisely at the same level. The second dyke is three or four hundred yards further on, towards the north-east; it is a much finer one, and so happily marked that it cannot be mistaken. A solitary rock, about 200 yards distant from the main, and visible from a greai |)art of the ^oa.st on each side, h called the Milestone, from its supposed distance from tlie Giant's Causeway, but in reality it is much nearer to it. The precipice here has considerably increased in height, being near to 100 feet, accurately perpendicular, and stra- tified as at the other dyke. This second dyke reaches from the summit to the water, beneath which we can see it continued northwards, until it reaches the Milestone, which is a part of ii. Though this dyke be also inaccessible, it is plainly form- ed of prisms laid horizontally, and extending quite across; its thickness seems to be about twelve feet. The strata are interrupted here, and resumed again, with* out disturbance, at the other side, as before; nor in either case does the slightest separation appear where these dykes meet the contiguous strata, all forming one solid niass. The third dyke is situated near the wesleru point of the bay, by which we begin to descend to the Giant's Cause- way ; of this an isolated fragment alone remains, about 100 feet long by 30 feet high ; like the rest it is composed of rude prisms laid horizontally. Our fourth dyke is at the Giant's Causeway itself ; it divides vertically part of the clilf, at the foot of which the cau«:eway is situated and descends quite down to it. The precipice is not perpendicular here, as at the other dykes, by which means our view of this one is partially in- terrupted ; there is, however, enongh of it laid bare to as- certain its nature beyond a doubt, and especially as vt is composed of horizcmtal prisms^ a j>roperty that seems es- sential to all whynn dykes. Where this dyke divides the upper part of the columnar stratum which forms the Giant's Causeway, the basalt pillars on the west side of it have fallen from their original vertical position, until they lean forward almost hori- zontally ; while on the east side of the wall they stand steadily vertical. .; The basalt septs, which frequently divide the strata in n)ines, and apjiear to be of the same nature with our whynn dvkes, are oenerallv attended bv a sinking or subsidinii; of the strata on one side of them, without disturi)iug the paralleliini- ^Cs Atcounl oftheWhynn Dykes in the parallelism of these strata. Tliis too is the case with out* own whynii dykes at Fairhead ; but oF the six dykes at Bengore pronrontory, this fourth is the only one where any thing like a subsiding or depression of the strata can be observed. This dyke is so accessible, that we are enabled to exa- mine its material and internal construction, from which we are precluded in the former cases ; the basalt of which this is composed, though contiguous to, or rather mixed with, the Causeway- pillars, is very different from the Cause- way basalt ; it is somewhat coarser, more granular in the fracture, and though darker than the gray whynn-slone of the Fairhead pillars, it resembles their colours, more than the fine blue of the Causeway basalt. The Causeway dyke is 13 or 16 feet thick, sometimes quite solid, sometimes shivery; it is entirely composed of ^mall trapezoidal prisms, their sides about an inch each, aiid their axes horizontal ; they are stronglv agglutinated together; and when this wall is attacked by the^slcdge, it sometimes breaks into fragments composed of an accumu- lation of the smaller prisms, abundance of which are scattered about the foot of the precipice. The fifth dyke is at the eastern point of the semicircular bay, of which the Giant's Causeway forms the western pomt; it is inaccessible, and visible only from the water; it cuts vertically three or four strata of table basalt, also a great stratum of red ochrcous matter, and is then lost in the precipice*. ♦ When I discoA'ered this wh^nn dyke in the year 1801. 1 was prevented fron\' examining it Hccurntely hy a heavy snrf,'>?vhich deterred me from venturing among the sunken rocks at the foot of the precipice ; the next summer I was more fortunate, and enabled twice to reach the bottom of the cliff, where the dyke inmiergcd into the water perpendicularly. 1 traced it downwards a's it cut the horizontal strata of table basalt verti- cally, aad observed each of these merging into its solid mass without any the least separation of the material; each stratum, having then as it were passed through the dyke, resumed its former position on the other side at the same level it held before, about forty yards from the place where the dyke immergcd in deep water; it arose again ten or twelve feet above the surface, continuing its course due north for thirty yards, exactly Hke a wait, showing the horizontal prinns of which it was constructed, whose bases formed the siirface of the wall. The most curious part of this dyke is discovered by tracing it up the clifF, whose summit it reaches a little to the eastward of its original course; here it projects boldly from t!:e face of the rock like the rectangular corner of a miehtv wall afbout twenty feet thick: yet this curious wall is not entirely dyke, but only its west side, which, at its termiriation, shows the horizontal, prisms composing it ; the east side is formed by a range of vertical pillars fifty feet loirg, pari 9f ^a great columnar stratum which the dyke there cuts through. The Neighbourhood of the Giant's Causeway ^ ^c. 369 The sixth whynn dyke is at Port Spagna, the third semi- circular bay east from the Causeway; this is the only one of our whynn dykes that has ever yet been noticed. Mr. Mills (Phil. Trans. 1790) saw from the top of the cliff a kind of uhyim dyke,' which ran into the sea towards the N.N'.'E; but he did not go down to examine it, and it is from below only that any observations can be made upon it. This dyke runs into the sea, like a quay about 20 feet broad, formed of huge black stones; its direction near the water is S.S.W. and its two sides accurately parallel: having proceeded thus about 60 yards from the water, the eastern side deflects a little, forming an obtuse angle, while the western side proceeds further in its former direction; the breadth of the dyke thus increases for a little, but the western side is soon resumed parallel to, and at its former distance from, the other side, and the dyke proceeds now due south : all this is best explained by a figure. N.N.E. S.S.W. The dyke, after having proceeded a short way in its new The upper surface of this tremendous wall is easily approached from the top of the hill, and covered with high verdure. I have frequently dined upon it, as fortunately the surface is hollow in the middle, by which the dread of a perpendicular precipice, above 200 feet high, (and on three ^des not more than eipht or ten feet distant,) is considerably abated ; the height of -the point of the wall from the sea immediately under it is 320 feet. I dwell upon this dyke both because it is so easy of access from above, (for even carriages can drive to the edge of the clifF,) and also because it is so happily marked as not to be mistaken : il forms the middle point between the Giant's Causeway and the solitary pillar called the Chimney, or, in other words, the common horn of the two crescents or semicircular bays next to the Causeway on the east side, I will add an account of another dyke lately discovered by my friend capt. R. O'Neil: it is situated S or 400 yards N. W. from the beautiful villa called Seaport on Port Ballinstay, a mile and a half west from the Giant's Causeway. The face of the precipice here seems about 50 feet high, composed of horizontal strata of coarse basalt or trap, abounding with zeolite, and of a reddish tinge, friable, and decomp(i!iing ; all these strata, from the summit to the sea, are cut through obliquely at an angle of about 45 degrees, by a dyke of sound blue basalt, very fine at its edges, but coarser in the middle, and nearly five feet thick .- the fine basalt of this dyke and the coarse trapp of the strata, notwithstanding the difference of their grain, unite solidly on both sides of the dyke : this important fact is more easily ascertained here, than in any other dyke I know, it is so accessible. I must observe, that this dyke is not accurau'ly rectilineal. Vol. 35. No. 145. May 1810. A a direction. 370 Account of the Whynn Dykes in the direction, is lost under the rubble that has fallen from above; but whenever the precipice becomes perpendicular, it appears again in its last directron, cutting the strata v^t- tically from the bottom ot the precipice to the top, above 200 feet ; the height ot the upper part of the cliff above Uje se?i is here 330 feet. These strata are almost all columnar, and the horizontal prisms of the dyke are strongly contrasted with the vertical pillars of the strata. The basalt ot this dyke is very nearly of the same grain with that of the dyke at the Causeway, rather coarser, its fracture granular, and full of shining points ; but it differs materially from it in another respect^ the latter having but one principle of construction, to wit, the njinute prisms into which it breaks, and the agglutination of these form- ing it into a mere wall ; while the dyke at Port Spagna has, like some other varieties of our basalt, a double prin- ciple of construction, being first formed into huge massive prisms four and five feet in diameter, and these again being divided into small quadrangular prisms whose sidfcs do not ' exceed an inch. This property possessed by some varieties of our basalt, and other curious circumstances attending them, — as for instance, that some of our prismatic basalt in thin strata abound with marine exuvise, shells, and impressions of cornua ammcnis*, while others, columnar and prismatic, but not articulated, and others columnar, prismatic, and articulated, coiitain cavities full of ftvsh water to the amc'unt of a thimble-full : all these facts have hitherto escaped notice. Naturalists, who visit our coast, rarely allow themselves time enough to examine any thing, and, while there, are occupied in looking for arguments to support the theory they patronize, not in studying nature for information : they never examine any of our basalts but that of the Giant's Causeway ; this, it is true, has none of the properties I mention, it has but one principle of construction, to wit, * The nature of this stone is, I know, not yet fully ascertained. Sir Joseph Banks informe nie, that the specimens 1 sent to him are pronounced by his friends not lo be grnm/!€ or legitimate basalt. An eminent Scotch naturalist, who -visited the spot last summer, I am told, asserts this stone to Lc chi.' • t. petrcfiitx or arkislus. On the other bide, Mr. Kirwan, to whom I gave specimens, asserts in a late publication, that it is br.salt: our ingenious Mr. Hig-gins is of the same opinion, and tne celebrated Professor Pictet of Geneva, who did me the Jbcnour of a visit last summer', considers it to be basalt containing a greater portiou of siUx thau usual, 1 believe Mons. Pictet is right. the Neighbourhood of the Giant's Caziseway^ &c, 371 the visible prismatic form so much admired; this after- wards breaks indifferently in all directions. To return to my subject : — Though the basalt septs in mines in giMieral, and every one of our own whynn dykes at Ballycastle, are attended by a depression of the strata on one side ; yet those I have described at Bengore Head are accomj^anied by nothing similar, except the one at the Causeway; and proceeding further eastward, coasting this promontory, we meet vv'ith three depressions of our strata, where nothing like a whynn dyke is to be foui>d. The first is singular and beautiful ; it is near a mile east from the Causeway, and a quarter of a mile beyond the last dyke. The precipice here is uncommonly magnificent^ its height more than 350 feet above the water ; and the upper part of this, which Is accurately perpendicular and extends half a mile on either side, is 150 feet. This whole face is composed of three strata, two of them formed of superb basalt pillars 45 and 55 feet long, with an intermediate stratum, near 60 feet, of another variety of basalt ; the lowermost of these strata, when produced westward, dips, and at its intersection with the sea forms the Giant's Causeway. This grand facade, together with the whole promontory, is as it were cut down and bisected by a vertical plane, ort the west side of which the promontory and all its strata have sunk and subsided about 40 feet, without any othei* shake or disturbance, all the strata in the subsided part still remaining accurately parallel to the permanent strata, and proceeding westward in their former direction, only from points 40 feet lower. An account of the variety, arrangement, and alternations of these strata, so completely displayed in the superb face of this precipice, where nature seems to have intended to exhibit to the philosopher the order in which she has dis- posed her materials, without putting him to the trouble of penetrating into the bowels of the earth, would lead me far beyond the limits of a letter. How these strata, with their ascent, culminations, dip, and immersions, have hi*- tlierto escaped the observation of naturalists is quite be- yond my comprehension*. The two depressions further east are much inferior to this } I shall only observe that there is not the least ap- pearance ♦ I cannot avoid quoting a passage from a late traveller, who seems to possess two qualities very necessary in a naturalist, to wit, attentive observa^ tian -jLud freedom Jrom st/stem. He says, " No subject is more interesting or A a 2 useful 372 Account of the IVIiyfin Dykes in the ' pearance of crack or disruption, the strata on both side* of the depression are all consolidated into one mass. When searching for whynn dykes upon our northern coast, I was obliged to omii about four miles of it lying between Beng(ire-Head and Carrickarede, as bcingf too distaiU from Porlrush and Ballycastle, where I was used to take boat, and totally void of shelter, even for the smallest craii. To the westward of Ballycastle I saw only one dyke. On the east side of Kcnbaan Point, a rock emerges from the water, which I have no doubt is part of a dyke, from the appearance it made ; and as I approached it, I perceived it was formed of horizontal prisms : here too a ncv.- feature occurred, common indeed in the dykes further eastward, but which f had not observed in any of those I had yet examined: the centre and sides of this one were con- structed differently, the prisms in the centre being larger than those in the sides, and all very neat, the grain too probably, as in other cases, also differed ; but I was pre- cluded from examining any «)f the circun)stances which attended this cuiious little solitary rock, by the violent surf which then broke upon it. Hitherto the precipice cut through by the whynn dykes, and the rocks from among which they sometimes emerge, were all basalt, uniformly stratified ; but the accumulation of these strata, after regularly dipping, immerges beneath the sea to the westward of Ballycastle, and a new system of materials arises at the end of the strand to the eastward, to wit, alternate strata of freestone and coal ; these are cut through exactly in the same manner the basalt strata were, bv vertical whynn dykes, which all run into the sea, across the l)t.ach at the foot of the precipice. The first of these is about tw'O iliilcs from Ballycastle, and though a rude imperfect one, it is not to be overlooked ; the black or dark blue of the basalt being strongly con- trasted with the brown colour of the freestone it passes through on the beach j here the high road runs close un- der the precipice, and affords a gt)od opportunity to ex- amine the contacts of the basalt dyke with the freestone it cuts through. 'i he next dyke, some hundred yards further east, is more useful than an exammation of the intestine position of strata and veins: — in short, ui>ou' this is louaded aH our knowledge of ;^oIugy ; it is, however, rtUendcuTviili jfieat lal>our and di?u:aiiy/' ^Jameson's Mineralogy, of Scot- Lad and Arrau, [jaj^e -. - " ':::amiaatiou isattciidcd ncith'.r witK Lboui- :*Ji- difiicU' per feet J NeigklourTiood of the Giant* s Causeway^ &c, 373 perfect, and so accessible on 1 he beach, that its singular construction can be examined without any trouble ; it is of the same breadth with mo^t of the others, that is, about twelve feet; it more accurately resembles a ('juay than any of them, its surface is fiat and its sides perpendicular, it is divided in its whole length by three right lines, one bisect- ing it through its middle^ and one on each side of this, about a foot distant. These three hnes determine the style of masonry (if I may use the expression) with which it is built, to wit, ho- rizontal prisms about five feet long, laid in rows on each side, and in the middle two rows of prisms about one foot square each. 1 attempt a skccth of these lines thus : 1 1- 1 1 1 1 1 1 1 M 1 1 1 1 M 1 1 1 1 1 1 i II 1 • 1 i i i 1 1 1 1, The bases of the long prisms show their polygonal figures on the sides of the dyke, and, if taken up and laid hori- zontally, would exhibit a rude pave : these prisms are ob- viously composed of smaller ones like those at Port Spagna, but I had not a sledge sufficiently weighty to ascertain th*i fact with precision. When I was on the spot, Mr.Magawly, who is concern- ed in and superintends the colliery, told me they were then cutting across this dyke 700 yards within the pre- cipice. The next dyke is of ruder bas^alt, and more imperfect 5 it seems to exhibit nothing remarkable. The fourth Ballycastle dyke, or as it is called there the Great Gaw, emerges from beneath the precipice, of the same breadth and of the same rude material and construc- tion with the first and third ; but it is soon joined by what the colliers call its wing, that is a new wall annexed to it on each side, by which it becomes triple ; these wings are of a very ditlerent material from the centre, being precisely the same in grain with the very fine Portrush stone, which sometimes contains shells and impressions of cornua am- mouLs, but in these wings I did not observe any, A a 3 When 374 Account of the IVlujnn Dykes in the * When this dyke enters the Water, it accumulates into an island, or rock, of much greater height and breadth, still the two materials keeping distinct, though so united at the contact as to form but one stone: thus the arrangement of the coarse and very fine basalt here and at Portrush, is precisely the same, saving only one difference, that at the latter place the planes of the strata are horizontal, while at the Great Gaw of Fairhead they are vertical, and in both places grow into each other without interrupting the con- tinuity or solidity of the material, yet leaving the line of ilemarcation distinct. Though the precipice at this part of Fairhead be not so accurately perpendicular as at Bengore, yet the depression of the strata on one side of this dyke is visible from the water ; and what is curious, a range of massive pillars, near 3 00 feet each, appears over the permanent part, while over the depressed part nothing is to be seen ; whence it is plain that these strata have not been depressed by incum- bent weight. The miners tell me there is also a fifth dyke here, faintly marked without the precipice, while the gaw, or sept, wiihin the mine is to them very important, and has also its depression on one side, like all the others at Fairhead, while at Bengore head no depression is found but in the dyke at the Causeway ', all these depressions, as well as those at Bengore, where no dyke is found, are on the west side of the line, or plane, sep:?rating the permanent from the sub- sided part. J nienlion this curious fact for the informa- tion of geologists who may possibly make some use of it. These singular walls are not confined to the northern coast of our basalt country ; its eastern side abounds with them still more. It w^s not in my power to examine any of those ejfcept such as lie in the bay of Belfast, but my . ingenious friend Dr. M'Donald (a zealous mineralogist, whose pursuits in that line have of late been much im- peded by great success in his profession,) informs me that they commence near Murlogh, where my tour on that side .ended ; that they are very numerous about Torr point, Garron point, and in general on all projecting points on that coast; and he conceives (I think judiciously) that points being found where the dykes are most numerouSj • I mentioned before that some naturalists have denied this Portrtif^h stone to b'e basalt ; but its bpin^j found here in a wliynn dyke aeenis strongly to support the affiniative, as I have never heard of a whynn dyke composed pf any material but basah alone. arises Nelghlonrhood of the Glanfs Causeway, &c, 375 trises fmni the protection they give the land in those places,' -preventing the sea iroin making the same inroads there it did on the adjacent parts. Dr. M*Donald and I examined together the dykes at White iiouse point, four miles from Belfast; several of them arc crowded together, three or four run parallel in an E. S. C. direction at about 150 yards from each other, and are in one place crossed by another at acute angles; several of these dykes, I am told, are traced across the county of Down on the op[X)site side of Belfast lough. Though these dykes were so near, yet they dffTcred mate- rially from each other; in many the middle part and the sides were not of the same grain, nor constituted on the same principle; in some we found zeolite in the centre, but not in the sides ; in others the middle part was formed by cutting it across (no doubt into prisms), while the sides were a rude mass studded with coarse round stones, about the size of an eighteen-pound ball ; these last Dr. M'Do- nald assured me he had often broken, and found them composed of concentric spheres, like the pellicles of an onion; some of the dykes were of solid massive prisms laid quite across, while one or two had a longitudinal di- vision running through their middle, as in the second dyke at Fairhead. In all, the lines marking the construction of the dykes, whether accurate or faint, were across at right angles to their directions, but the perfection of the workmanship was very different ; and when we attacked them with a light sledge, we found some to crumble, being in a state of de- composition, others resisted our efforts, while some broke into small quadrangdlar prisms, like the dykes at Port Spagna and the Giant's Causeway. Dr. McDonald showed me in his cabinet prisms he had taken from a quarry (no doubt a dyke) near Belfast ; they were nine or ten inches long, and entirely composed of triano:ular pyramids of the same length, put together as if to illustrate Prop. 7. lib. 12th Eucl. Elem. I had found two or three small triangular pyramids among the quadran- gular prisms at the Giant's Causeway dyke, but at the Belfast dyke triangular pyramids were the sole eleiiientary figure. As the shore in Belfast lough is low, there are but few opportunities of examining the materials that come in con- tact with the basalt dykes ; in fact I noticed but two, stra- tified clay and freestone ; this clay is very plentiful on the ghore and the adjacent country; it is arranged in very thin A a 4 horizontal S76 Account of the IVIiynn Dykes in the horizontal strala, and when t a posed to the air hardens al- most to the consistence of stone. At the contact the basalt and freestone were stronglv united together, and for two or three inches the basalt had in some sort acquired the colour and grain of the sand- stone : I was particularly attentive to this fact, as Mr. Wer- ner alleges the transition of basalt into other stones, and Mr. Jameson found in Arran (pages 131 and 135) basalt sometimes mixed with, and at others penetrated by, sand- stone; but on this occasion Dr. M'Donald, by some ex- periments, found that notwithstanding the freestone ap- pearance the stone remained pure basalt. The basaltic area, from the north and east sides of which these singular walls diverge in such abundance, compre- hends a considerable part of the country of Derry, and a much greater of the county of Antrim ; its breadth varies from 20 to near 30 miles, and its length exceeds 35 ; it seems composed almost exclusively of vast and steady ba- salt strata accumulated upon each other; in one' place wc count 16, in others we conjecture more, especially at Ma- gilligan rock, as wc know the basalt to be 1200 feet deep there. This whole mass rests upon a vast stratum of while limestone about 200 feet thick, of the same extent with the basaltic area, but discoverable only at its periphery, which extends above 80 miles. This mighty stratum ascends to the southwad, until its lower edge acquires on the east side a height of 800 feet, and on the west at least 1700; the country below the limestone stratum, and without it, is on the west sitle mostly schistus, on the east sandstone and clay peneti^aled by basalt dykes, which furnish stones in abundance for all purposes. The Scotch whvnn dykes have been generally supposed to originate m Ireland. If this f;ict be admitted, we can easily trace them by attending to the directions of our own; thus those that issue from the coast west of Ballycastle, proceeding north with a slight inclination to the east, are to be sought for in Islay, Jura, Mull, 8cc., where Mr. Mills actually found them in great numbers. Our dykes which are seen at.Murlog, Torr, and Cushen- dun, are obviously those which, having crossed rhe Mull of Cjutyre, were observed by Mr. ^ajiieson in such abun- dance in the Isle of Arran. Dr. Hutton also mention* 20 or 30 whynn dykes he found '* in the shifc of Ayr to the north of Irvine on the coast," These correspond with the numerous dykes about Gar roil Neighlourhood of the Giant* s Causeway, &c, 377 Garron point and its neighbourhood, whose rectilineal course is directed towards that part of the Scotch coast. The dykes about Larne may be expected to be found on the Mull of Galloway, while those I examined far up in Belfast lough, on account of their S. E. dnection, probably do not catch Scotland, nor meet land until they arrive on the coast of Cuniberland. Whether our whynn dykes be identically the same with those on the Scotch coast opposite, is not easily ascertained, though highly pn^bable ; but even C()nl]niag ourselves to our own country, we Hud sufficient matter for astonish- ment in conteu^plating our basaltic area, formed by accu- mulations of horizontal strata, with numberless vertical planes radiating from it : had Dr. Beddoes been acquainted with this structure of our basaltic country, I think he would scarcely have asserted, that *' a right knowledge of basaltcs is conducting us fast to a just theory of the earth." 1 think very difl'ttrcntTy Irom Dr. Bcddocs, and conceive that instead of assisting^ basaltic facts are throwing new diffi- culties in the way of cosmogonists, who flatter themselves they have developed the secret of nature; and that those in my country, (to which I confine myself) are utterly irre- (9ancileable to any theory I have met with. Two sects of naturalists, distinguished by the names of Volcamits and Plutonists^ have of late taken possession of all the basalt in the world, and have divided it between themselves, under the descriptions of en/pted and uneriipied lava 'j and they have so convinced Dr. Beddoes of the vali- diiy of their cuiim, that he says, *' I shall assume the origin of basahes from subterranean fusion to be thoroughly esta- blished." After such a round assumption it may be deemed uncivil to question the igneous origin of our basalt dykes ; but natural history is not to be sacrificed out of respect to con- fident assertion : 1 will therefore try by the test oi Jacts whether that description of basahes (which your lordship wishes for information upon) ever was in fusion. Foreigners seem to know little of whynn dykes except in mines. Mr. St. Fond found at Chamarelle in Vivarci^ what is obviously a whynn dyke, and it embarrassed hini more than any fact he ever met wiiii ; it will be found en- tertaining to look into his Vol. ex, de Vivarois, and into h\fi M in. des Vol, to sec. the difficulties into which this cow ant de lave compact e, this ruisseau de lasalie en fusion has thrown him, and the swingeing postulates he is obliged to make, in order to get over them. Dr. Hamil- 375 Account of the IFhynn Dykes in the Dr. Hamilton on behalf of the /-'o/raw/VA?, andDr.Hiittoii the great advocate for the FliUomc system, arc more ready at their expcdicnrs ; the first of these forms our whxnii dykes bv pouring in erupted lava at the upper aperture of mightv chasms ; while Dr. Mutton conceives these chasms were fiTled up by his own unerupted lava, forced up at the lower. In discussing the opinions of these gentlemen, I will make them the most liberal concessions; for instance, I will concede to both, that they have discovered the process by which nature has formed chasms of immeasurable length, innneasurable depth, and of inconsiderable, tliough uniform, breadth. i will concede to Dr. Harhilton that he has brought to the edge of the chasms his lava, *' th's foreign substance, which issuing from the vast mass of basahes that forms the northern extremity of Fairhead, has descended over the adjoining strata,'' and that he has it ready *' to Jill up each deft and vacuify." (Ham. Antrim, let. 5, part I .) I will also admit in favour of Dr. Hutton, that he has his unerupted lava ready at the bottom of these chasms, that he has his machinerv prepared for forcing it up, and ^ that he has surmounted his great difficulty, and discovered a mode of supporting such a mass when raised ; a point upon which, having failed himself, he would discourage others from forming conjectures. (Edinburgh Trans, vol. i. page 285.) Notwithstanding these concession?, it will not be difficult to show that these gentlemen have not discovered the secret of nature in the construction of these singular walls, and that they were not formed by liquid lava filling up mighty chasms. 1st. Many of our contiguous dykes differ materially from each other, yet iheir proximity is such, that, according to the theory of either Dr. Hamilion or Dr. Hutton, they must have been filled up from the same source, and with the snme material. 2dlv. Many of these dykes, both in Ireland and Scot- land, show a material difference between their middle parts and their sides, both in grain and ii^ternal principle of construction ; the chaiige too is not gradual, but per sai'.um, as if the dissirrnlar parts were separated from each other by planes parallel to their sides: all this is perfectly incompatible with the high state of fluidity in which rhe lava must have been, to enable it to fill up vast chasms of such diminutive breadth. 3dly. Neighhourkood of the Gian.t*s Cauaeway, c^c. 37^ 8dly. Our whynn dykes come in contact with a great variety of diflerent substances, without producing such efFect upon any one of them as might be expected froni the contiguity of so glowing a mass ; hut however this araument mav bear against the Folcunists, the Plntonists will say it does not apply to them, for the chemical opera- tions of nature are carried on in Dr. Hutton's subterranean Jaboratorv very diflferentlv from what we see on the surface of our globe : in the former Dr. Hutton says calcareous strata are covsoUdaied by the operation of heat atid simple fusion, and again, having proved that these strata had been consolidated by simple fusion^ (page 253.) Dr. Hutton however confesses it is not easy to comprehend this : "^and to be convinced that this calcareous stone, which calcines so easily in our fires, should have been brought into fusion by subterraneous beat without sufTering calcination, "mus't require a chain o( rcRsomng which every 07ie is not able io comprelievd," (page 271.) But it is not necessary on this occasion to enter into the mysteries of a laboratory, to which we have not access, nor to calculate the force of Dr. Hutton's great agent com- pression; for our observations on the contacts of the matter of our whynn dykes with the substances they encounter, being made on the surface of the earth, in the open air, even admitting tho«e dykes to be formed as Dr. Hutton supposes, his uncrupted lava is now become erupted, and of course, to use his own words, *^ those substances which palcine and vitrify in our fires, should suffer similar changes when delivered from a compression which renders them fixed." (Edinburgh Trans, page 280.) . I am aware I must fatigue your lordship by dwelling so long upon the question of the igneou? origin of our whynn dykes ; but as most modern writers and travellers call them lava veivs, and ihe facts 1 have observed with much atten- tion, induce me to combat so general and so popular an -opinion, I hope you will excuse me for adding a fourth ' argument, which I conceive to be conclusive. All substances, when ignited, are in a high state of di- latation ; this is followed, when they cool, by a contraction, 7/77^ retraile, bv which they occupy le:?s space than they did Kvhcn heated; of course, had our dykes been chasms filled lip with glowing lava, when this material cooled and con- tracted, it could no longer fill up these chasms as before, but must crack and separate from their sides, Icavino- in- tervals and disruptions^ byt nothing like this is observed, the 360 Account of the JVhyvn Dykes in the the dyke and contiguous matter, whatever it be, arc solidlv united together, forming but one mass. These whynn dykes suggest other curious questions: Were they formed at the same tinie \vith the contiguous materials ? Were they posterior to them, as Dr. Hamilton and Dr. Hutton suppose? Or, were they antecedent to the stratified masses, that every where come in contact with tijem ? The inutility of such speculations deters me from enter- ing into them. I must however confess, that the facts seem to give stronger negatives to the two first questions, than to the last. But who would hazard so bold an opinion, as that these mighty walls were the first part of our world that was formed. What an idea must it convey to us of lh\?> frame- ti'ork or sktleton of our globe ! A new theory I conceive more likely to be a nuisance than an acquisition to natural history ; and that tlie road to the advancement of the science would be better laid open by destroying some of those we have already. Should therefore your lordship ihiiik that the arguments I have adduced against the igneous origin of our whynn dykes are of any weight, I will probably make further in- roads into the territories o{' Fulcajii and question the ig- neous origin of basalt in general. To this y^Hir lordship will very likely reply, that the topic is w'orn threadbare ; that most modern writers, without entering into the question, pronounce it to be already de» cided in the affimative ; and that I shall never obtain atten- tion to so stale a subject. My opportunities, however, to procure information upon it have been superior to those of any other person ; I have lived very many summers in the most important basaltic country in the world, and mv fondness for the sea, and possession of boats, have enabled me repeatedly to explore our coast, which 1 know that no other naturalist ever did. It is to this coast and country that the advocates for parti- cular opinions come to look for arguments to support the theories they patronize; it is painful to follow such gentle- men, correcting their statements, and contradicting their assertions; nor are they cursory travellers alone who mis- represent our facts; it will appear that men of science and ability are equally disposed t«) support their opinions at any expense; — a favourite theory is an adopted child, that must be maintained. But Neighloiirhood of the GlanVs Causeway^ &c. 381 But it is not by exposing the errors of others that science, and especially natural fmtory, is to be advanced ; nor is it by puzzHng ourselves to find out in what manner, and by what process, nature has exec uted her work ; let us rather examine attentively what she has actually done; let us quit disputing abcmt the whimsies of our own brains, and siudy the code of facts. In our basaltic country these are curious, as well as abun- dant; and it will be from such of these alone as have escaped the attention of my predecessors, and from the geological construction of the country, that the arguments to be applied to the question of the igneous origin of basalt will be drawn ; atid whatever may be their weight, at least they will have the merit of novelty to recommend them, I am. with great respect. Your lordship's Most obedient humble servant, Portrush. W. Richardson. P. S. When I found an opportunity for examining the whvnn dykes to the northward of VVhiiehouse-poinl, I omitted several under the demesne called Macedon, which were much covered by sea-wrack ; here I knew the surfaces of the dykes were decomposed, and their distinctive cha* racters defaced. Between Macedon and Carrickfergus there are many, all as usual differing from each other; some not so recti- lineal in their course as those I have hitherto described ; iu one or two the prismatic construclif)n wai? scarcely perceiva- ble, while in the greater number the arrangement of these prisms laid across the dyke was most distinct. In two contiguous dykes I observed, that the axes of these prisms were not horizontal as usual, but in one greatly elevated to the north, and in the other towards the south, Hutnan attention could not follow the variety which na- ture has displayed in the tormalion of these dykes; there- fore, not to fatigue the reader, I will describe but two more particularly ; I select these, both on account of the new circumstances attending them, and also because thev are easy of access, being within a few yards of the great road from fiell'ast to Carnckfergus. The first of these runs eastward along the strand, about 400 yards south of the gallery ; we approached it from the north, and found it composed of louii; well-formed hori- zontal prisms, lined on the north side by a sort of basaltic wail about 18 inches thick: this a military gentleman of * ' our 382 • Koike respecting Neto Books, our party called its revetement ; I adopt the word on ihw occasion for convenience. After we had traced the dyke eastward for several yards, we observed this revetement separate from it, and diverge at a considerable angle, then, forming a curve, disappear beneath the sand to the north-east; this new circumstance exciting our attention, we traced the revetement back, to the dyke, then along it to the westward, when after -^ome time we perceived, it entering the dyke at an acute angle, and crossing it diagonally ; when across, it formed for se- veral yards a revetement on the south side of the dyke, then diverging from it, and curving as before, it was again lost under the sand to the south-west. The second dyke I will describe particularly, lies about 500 yards north from the silver stream, and about three miles from Carrickfergus; it seemed composed of four or five distinct walls, agglutinated together; in each of these the prismatic construction was dilferent from that of the others, and in one the axes of its prisms were not as usual at right angles, but oblique to the ihrection of the dyke. A new circumstance occurt'ed here too ; this dyke, about 25 feet broad, had a revetement of freestone on each side, and was also twice or thrice penetrated by walls of freestone similar to, and in the same direction with, the basalt walls between which they lay ; these freestone walls were more than a foot broad, and sometimes composed of horizontal laminae, and at others of vertical. I have since discovered a magnificent dyke in the face of the stupendous precipice of Cave hill* which it cuts verti- cally near 200 feet, and is afterwards to be traced a great way down the hill. Though this dyke be attended by very curious circum- fttances, I will take no further notice of it, as I hope to see it soon accurately described by my ingenious friend Dr. McDonald, who was with me when i discovered it, and whose vicinity affords him better opportunities of accurately examining this beautiful and interesting fa9ade. LVIIT. Notice respecting New Books. A. NEW edition of Dr. Henr)''s chemical work is in the press, and will be published in the course of a few weeks* * A stratified basaltic mountain, nearly hanging; oYer Belfast; it is well worth Uie attem.ion of natiiralisw. "Royal SoQiety, 3^3 He has found it impossible to give a sufficiently ample and distinct view of the numerous and important discoveries which have been made in the science during the two last years," without extending the work to a second volume. And as its original title would but ill accord with the en- larged form under which the book will now appear, it will be changed to that of '* Elements of Experimental Chemistry." LIX. Proceedings of Learned Societies, ROYAL SOCIETY. vJn the 3d, 10th, and 17th of May, the reading of Mr. Macartney's observations on luminous insects was con- tinued. The result of the author's researches has enabled him to state that J 2 dift'erent genera of insects, which in- clude an immense number of species, emit light. Seven of these genera belong to the order of moLlusca^ and the other five to the hemipterous, as the J u Igor ce ; the apte- rous, as the cancer pulex and Julge?iSj &c. Mr. Macartney took an historical survey of what has been written on lu- minous insects, related the discoveries of different voyagers, such as those of Sir Joseph Banks, who discovered two species, the cancer pulex near Madeira, in 1774, with capt. Cook, and the medusa noctiluca, Capt. Horsburgh also discovered two species in the Arabian sea, which he gave to the author, one of them like a wood louse, the other he called medusa scintdlans. The same accurate ob- server also noticed various luminous appearances of the sea, and some insects, which on being pressed eniit a lumi- nous fluid. He also gave to Mr. M. a drawing of one of the insects, which he took out of the water at a time when the sea appeared almost white, like a vast field of ice covered with snow. This appearance is ascribed by the author to immense quantities oi medusa scinlillanSf which emit flashes of light, and so frequently as to assume a con- tinued brightness. To this species of medusa the author attributes the sudden flashes of light which are occasionally seen on our own sea shores. Mr. M. has also discovered three different species of luminous insects on the southern coasts of Kngland. In the course of his inquiries, he ap- pears to doubt the luminousness of the cancer pulex, but notices the pyrosoma ataLantica^ a worm -shaped luminous 384 . Royal Society, — Linncean Society, insect, observed by IvI. Perot, of which only one genu^ or species has yet been discovered. In summing up some concluding remarks on the caus^ oF this luminous qualily in insects, Mr. M. expresses him- self with great diffidence, and from the experiments of Kumford, and his own obbcrvations, hesitates in stating whether tight is not rather a quality than a substance, as all the phsenomena of luminous insects tend to give probability to the former opinion. The medusa^ he observes, cai> emit light for any indefinite time : their liglit and that of other sea-insects appear of no specific use to the animal, but that of glow-worms and flics serves to make them known to each other in the night. All luminous animals, shun the light of day, and hence the author infers that they cannot have imbibed solar light sufficient to emit so much during the night; that the luminous matter of the sea, or medusa^ has nothing in it phosphoric or inflammable; that the manner of secreting this luminous matter (if so it be) is yet wholly unknown ; that the sudden death of the ani- TDals, and consequent extinction of their luminousness ; pre- vent all anatomical or microscopical observations, and that the number ot creatures possessing this peculiarity is very considerable. He related a great number of experiments, all of which tended to denionstrate that this light has nothing in it of a phosphorescent quality, as universally believed, and that, whatever it may be, it is no longer attributable to the presence of phosphoric or inflammable matter. May 24. The introduction to a paper on the sexual or- gans and mode of generation 'if the squaliis genus, or dog- fish, by Mr. Home, was read. It related principally to a description of those organs in the fishes, of which Mr. H. has before given some general accounts to the Royal Society. LIN N^ AN SOCIETV. April 17. — The President in the chair. The following papers were read : Observations by Olof Swartz, M.D. on some former Species of Andromeda, properlv belonging to the Genus Menziesia: — On the supposed Etfects of Ivy on Trees, by Hum])hry Repton, Esq. : — On the Fasciola Hepatica, by Mrs. Cobbold. May 1. — A paper was read On the Genus Androea, with Descriptions of four British Species, by W. J. Hooker, Esq., F.L.S. I'hurfday, May 24, being the anniversary of the birth- day of Linnasus, the Linnasan Societv met at their house in iVernenan Natural History SMety, 385 in Gerard Street, in pursuance of their laws and charter,' t3 elect a president, council, and officers for the ensjing year: when tlie following five new members of council were elected : — John Blackhurne, esq. Edward Forster, esq. George Milne, esq. Kdward lludge, esq. and Edward Lord Stanley. And the following were chostn as officers : James Edward Smith, M. D. president; Thomas Mars'mm, esq. treasurer; Alexander JVlacLcay, esq. secretary; and Mr. Richard Taylor, under secretary. The society afterwards dined together at Freemasons* Tavern, as usual. WERNEBIAN NATURAL HISTORY SOCIETr. At the meeting of this society, on the JthApril, Dr. Macknight read a niineralogical notice, on the tract of the Highlands from Killin to Braemar, by the way Of Glen Tilt. V)C\\ Lawers is comj)osed of undulated, mica-slate, which at the sun)mit is yellowish gr ly, and in some varie- ties so full of quartz as to resemble a sandstone. Towards Logierait, beautiful garnets begin to appear. Beyond Mul- Icnearu^, gneiss occurs ; also limestone, hornblende-slate, an4 sienit'e. Besides the substances first mentioned, Glesrjllt jsl remarkable by a peculiar aggregate of feldspar, hornblend:^,-; and occasionally quartz ; in which the various proportion^: of these ingredients cxliibit the rock under various asj^ecls: of the sienitic and greenstone species. It is distinguished from granite (for which it has been n}istaken) not only by: the uncrystallized state of the feldspar, but by the preser)ce> of hornblende, and the absence of mica. Professor .fame-, son has entitled it sieniiic greenstone. Tt occurs, in con- formable beds ; particularly one of great size, which inter- sects the channel of the river at different places, near the lodge. Crossing the mountains from Glen Tilt .to the course of the Dee, we find hornstene, feldspar-porphyry, and limestone, subordinate to mica-slate and gneiss ; liil we reach the Castletown of Braemar, where the graiiite of the Grampians at length appears. At the same meeting, a communication from colonel Tmrie was read, descrioing the conglomerate-rock of the Grampians, and tracing it from near Stonehaven to the Burn, and again at Callender, 80 miles distant. The po- sition of this conglomerate- rock is nearly vertical ; and of this fact, in col. Inuie's opinion, no satisfactory explana- tion has yet been given. — At this meeting, also, there was laid befot'c the society an accurate section of the coal-field at Alloa, accompanied with interesting remarks^ bv Mr. Vol. 33. No. 143. May ISIO. Bb RobeifC 386 French Nuii(7nal Ihsfktvie. Robert Bald, civil engineer, ^nd manager of Mrv ^ri^feii^ of Mar's extensive coal-works. The depth o J; the section is 704 feet; the alternating strata arc 14.1 in nimiber ; and the total; amount of the difl«reiit bed,s of coal is 59 feet 4 inches^ — Captain Laskey likewise presented to the so- ciety a series of the remains of a curiowo fossil Encrinu% found iii.slatercUy near D,«nbar. FRENCH NATIONAL INSTITUTE. [Continued from p. 3^17.], GEOLOGY. The observations tVgm which geology can. derive the most important advantages, are certainly those which are directed to the subjects of fossil animals, but more particu- larly those which lived upon dry land. M. Cuvier has con^ tinned ti^e investigation of this important subject. He has brought to a termination, in conjunction with M. Brong- fiiart, the mineralogical geography of the environs of Pa^- ris, a slight sketch of which was- given in the account o¥- the labours of the Class for the year 1 808 *. He afterwards* directed his attention to the osseous heaps ifireches) on the- chores of the Mediterranean. Rocks similar to those which are to be seen at Gibraltar, near Terruel in Arragon, at Gette, at Antibes, at Nice, in Corsica, inDalmatia, and in- the isle of Cerigo, have been found in the fissures of the compact limestone which constitutes the principal soil o^ these various places, and they are all composed of the same- elements : it is a red cement, like brick, which conneats in a confused manner numerous fragments of bones and of' limestone in which these heaps^ are contained. All the bones found in these rocks belong to herbivorous animals, most of whidh are known still to exist oh the adjoining soil; thev are mixed with fresh- water shell s^.. This inclines us to think that these heaps are posterior to the last conti- nuance of the sea on our continents, but very ancient ne- vertheless ; since nothing proves that similar heaps have- been recently formed, and some of them, such as those \\v Corsica, contain even unknown animals. Alluvial earths also contain bones of herbivorous ani- mals: they bftve been discovered in the peat-mosses of the valley of tiic Somme, with slags* horns and heads of oxen, and in the envi"rons of Azoph, near the Black Sea. These bones have l)clonoed to a species of beaver : the former re- semble tho>e of the common beaver; the others, which .!* See, page 86 of the present volume of i\\t Phil. Mag^. Prench National InstUuie. i^j fofiri a complete hedcf, see'm to have belonged to i. much larger species than we are acquainted with ; and M. Fischer, who discovered this animal, has given it the natne of tro- gontherium, which M. Cuvier adopts as the specific name. Bones of herbivorous animals have also been found iri schists. Three kinds have been described. M. Cuvier saw the figure of one which some authors regarded as having ap- pertained to an Indian boar, and others to a polecat. M. Cu- vier rather gives it the character of a herbivorous animal; but he ha§ not oeen able to ascertain the genus nor species. Among the fossil bones of ruminating animals found in loose strata, M. Cuvier has recognised a kind of elk different from that with which we are now acquainted. The bones of this animal have been found in England and Ireland, near the Rhine, and in the environs ot Paris, in beds of marl at no great depth, and they seem to hav^; been deposited in fresh water. Some horns discovered in abundance in the neighbourhood of Etampes, in sand sur- mounted by limestone of fresh water formation, prove the existence of a small species of rein-deer which seems no longer to exist. M. Cuvier has besides observed remains of horns of goats, fallow-deer and stags^ which do not seem to differ essentially from the horns of the existing species : " Nothing," says our author, " is more abun- dant: all the recent alluviations dug up have furnished theni ; and if we do not find plenty of testimony as to these fossil bones, it is because from presenting themselves at trifling depths they have not been thought worthy of much notice.*' In the fossils of ruminating aiiimals with hollow horns, M. Cuvier has recognised crania of aurochs, disaovered" in the banks of the Rhine and the Vistula, in the envi- rons of Cracow, in Holland, and in North America. These crania exceed in size those of the aurochs; but, as M. Cuvier observes, this difference may be ascribed to the abundance of food which these animals formerly possessed, when ranging at pleasure through the vast forests and paij- turages of France and Germany. There is another kind of fossil cranium differing only from our present oxen from the size, being larger and the horns being in a different direction. These crania have been found hi the vallev of the Somnie, in Suabia, Prussia, England, and Italy. " If we recollect," says M. Cuvier^ ** that the ancients distinguished in Gaul and Germany two kinds of wild oxen, the urus and the bison; may we not suppose that one vf the two, after furnishing our present B b 2 rac« 383 French National Institute. race of oxen, was extirpated in his savage state; while the ojher, which could not he siil)dued, still subsists in small numbers in tlie forests of Lithuania alone?'* In loose soils we also meet with bones of horses and of wild boars: the former almost always accompany the fossil elephants, and are found along with the mastouonti, tigers, hyenas, and other bones of fossil animals discovered in alluvial soils : but it was impossible to ascertain if these dorses' bones belonged to a species different from our present race. The bones of wild boars have been for the most part procured from peat- mosses, and do not in the least difier from those of the wild boars of the present day. Other bones have been found, which M. Cuvicr has as- certained to belong to an vmknown spee'.cs of la man tin of manati. They have been discovered in strata of coarse ma rine limestone on the banks 'of the Layon, in the environs of Angers ; and they were mixed with other bones, some of which seemed to have belonged to a large species oi phocas, a,\u\ the others to a dolphin. The skeletons of three species of oviparous quadrupeds, preserved in calcareous schists, have also been the object of M. Cuvicr*s researches. The first was found in the schists of Qi^nigen, situated on the right bank of the Rhine, at the mouih of the lake of Consrance. It had been described and engraved as the skeleton of an antediluvian man; but this error was refuted. M. Cuvier proves by a series of osteological inquiries that this reptile was analogous to a salamander, and belongs to the genus proieiis. The second, also found in the same place, seems to have belonged to the toad genus, and resembles the biifo calamita. The third, and most singular, which was discovered in the (juarrics of Altmuhl, near Aichtedt and Pa[)penheim, in Franconia, and which had been described and drawn by Collini in the Memoirs of the Manheim Academy, is re- garded by M. Cuvier as having belonged to a species of otter. The length of its neck and head, its long^ snout armed with sharp teeth, and its long paws, indicate that this animal fed on insects, and that it caught them when flying : the size of its orbitary sockets also shows that it mu?t have had very large eyes, and that it was a nocturnal animal, like the bat. No beast of the present day has the least resemblance to it. M. Cuvier, has also published a Sn[)plement to his Me- moirs on the Fossils of Montmartrc; in which he gives the figure and description of an ornhholitc, much more com- plete than those which have been hillierto published. It is probaljJe Ftench National Insiltute, 389 probable that it belonged to the class of gallinacei, and the common quail is the modern species whicli it resembles. M. Sage has given us the description of some carpolites, or petrified fruits. One of them was the kernel of a nut becoa.e calcareous, and found at Lous-le-Saulnier: another seemed to have been the fruit of a wild nutmeg-tree, which grew at Madagascar and in some of the Moluccas ; its substance was also calcareous: the third seemed to have be- Jonged to something resembling the durion of India; it was transformed into jasper. To these new facts he subjoins some of the remarks which had been already made on carpolites,, and conchides that the petrified fruits found in our climate are exotics. He also enters into some chemical details, by means of which he explains how these petrifactions look place. BOTANr. Order and method will always be two objects of the first importance in natural history, and particularly in botany: they serve at one and the same time to establish the rela- tions which bodies have with each other, and to guide the observer in the midst of the innumerable productions of nature. The most celebrated naturalists have made it the particular object of their studies ; and the knowledge which the real science of the various systems requires^ could never have been embraced but for them. / M. Jussieu, who has so just a title to be considered as the legislator of botany, has formed a new order of plants under the name of Monimise : the genera of which it is composed are, the ruizia, the monimia^ the ambora, and perhaps the cUrosma, the pavofiia, and the atherosperma. 'I'his or- der ouglit to be placed immediately before the family of the Utriceae; but after the Monimias M. Jussieu places the caly- cantkus, heretofore united to the Rosaceie ; he considers it as the type of a new order, which will serve as a stage be- tween the Monimise and the Utricese. M. Palisot Beauvois has proceeded wiih his inquiries into the order of Gramineae. He has studied their organs of fruciification more exactly than any person had done before him ; has founded on the organization ol" each of the parts of these organs the characters which ought to distinguish them from each other, and obiaiiied the means of divuling the different species of this order into genera, much more natural than those which had been hitherto adopted. M. Lal)illardiere has* made us acquainted with a new B b 3 pi rait ^9Q French National Instiiuie. plant of the family of Palm-trees, of which be has made a genus under the name oF ptijckosperma, and placed it next the elati and arccas. This plant was discovered by the author in New Ireland : it rises frequently to the height of do feet and upwards, and yet its trunk is only two or three inches in diameter. These proportions induced him to give it the name of gracilis. It is astonishing, as M. Labillar- diere remarks, that so slender a tree can support itself; but we know that in all the monocotyledons, the hardest of the ligneous part is external, and this structure ^\ives to the plants of this class a strength which those cannot possess whose most solid fibres are in the centre. M. Lamouroux has presented to the Class a very exten- sive work on marine plants. Little or no attention has been paid to these singular vegetables, and tho.y have been arranged in rather an awkward manner: M, Lamouroux, by forming into a single group all the plants known to ex- ist in the sea, sd^enni to have wrought an advantageous change. The little progress which had been made in the study of the algae, was the cause of the disagreement among bota- nists as to the organs which serve to the reproduction of these Cryptogamia. M. Correa, in a work written expressly on this subject, had recognised male and female organs in the tubercles placed at the extremities of the ramifications of these plants. M. Ivamouroux partakes of this opinion ;but he characterizes with precision the different parts ef these organs, and thus throws a great deal of clearness on the gtudy of these singular vegetables. This author has besides observed that the kind of algae which grow on granite, are never the same with those found on calcareous stone or on sand, and vice versa. As to their interna) organization, M. Decandolle had ascertained that it was devoidof vessels, and entirely fornied of cellular texture. M. Lamouroux di- stinguishes tvvo kinds of cellules ; thp one being long hexa- gons, which form the stalks and the nervous parts (ncr- pures) of the ramifications; the other kind is of the same form with the foregoing, hut has sides almost equal, and which constitute the membranous or Ibliaceous substance. M. Lam()urt)ux thinks that the foriner niay be analogous to the vessels, and the second to the uiricular texture oi the most perfect vegetables. Tnese general labours led the author to form in this family several new genera, which he jias also presented to the Class for their approval. M. Mirbcl has continued his researches on vegetable phy- giologv. Formerly it hud been ascertained that the albumen - " '' ■ ■ ' ^ <>f i French NhtionQl Ihsfkute, 3^1 inif tlie -seed generally served for the noiirishtnent of the younu- plant after germination: but this opinion perhaps had still need of support from posnive observations ; and M. Mirbel, by means of an experiinent equally simple at ingenious, seems to have dispelled }ill doubts on the sub* ject. The embryo contained in the grain of the a|biuin cepa becomes curved on being developed, so as to ionn a tail which issues from the ground, while the radicle and plumule stiU remain under it. If at this period of vegeta- tion we make any mark at an eqdal height on the two l>randies of the geriti, we shall see the speck nearest the tradicle rise alone in the case where the plant receives no Tiutriment except from the juices of the earth : if, on lh« contrary, it be only kept up by liie albumen of the seed, the speck of the plumule will rise above the other ; lastly, the specks will rise nearly equallv, if thje earth and the seed •concur to the development of the germ. It is this last phasnomenon that takes place ; it ceases when the albumen is eii+irely absorbed: in that case the young plant has suffi- cient strength to derive from the earth, or from the atmo- sphere, the nutriments which it will immediately recpiire. This memoir is accompanied by interesting observations on the ii^ermination of the asparagus, and on ihe manner in -which tlie leaves of thi-s plan:, sheathing themselves at first like all those of the monocotyledons, become by the growth of the stalk, lateral atid opposite^ and afterwards lateral and alternate. In another memoir M. Mirbel has undertaken some nC\v enquiries respecting the germination of the nelumbo. Bo- tanists were not agreed as to the class to which this plant ought to be referred, and as lo the nature of the two fleshy lobes in the nndst of which il takes its origin. Some, not observing^ any radicles developetl in the germination of this plant, thought that it was entirely devoid of them; som« regarded tlie lobes just mentioned as roots ; and others re- -garded them as peculiar organs, and analogous to the viteU ius. It is by means of anatomical observations that M, Mirbel endeavours to di-pel the doubts which these various opinions have raised. He recognised in the first place, iu the nelumbo, all live characters which distinguish the plants with several cotyledons from the plants with a single coty- ledon. He afterwards found in the lobes of this plant ves^ sels analogous to those of the cotyledons, and he observed, ;*t the point where these lobes join, oth'ir vessels which are united in the same manner with those which characterize the radicles la the cmliryos furnisheii witb thi$ organ : .Bb4 and 3$ 2 French Na I tonal Ins titute, and he conduces that the nelumbo docs not differ essen* lially from the other plants of its class. M. Correa, although he agrees with M. Mirbel that the nelumbo is a plant with two colvledons, does not share in his opinion respecting the nature of the lobes : he thinks, withGasrtncr, thatthese organs have a considcrablearialogy wiili the vitcllus, and he compares thcn» with the fleshy tubercles of the roots of the orchis. The plants, as this learned botanist observes, have a double and relative organic zalion. — on the one hand, wiili the earth in which they ought to take root, and on the oiher hand, with the air in which their folia 2:e is developed; the roots as allotted to the ascending vegetation, and the leaves to the descend- ing vegetation ; and it is at the point where these two sy- stems of organization unite, that the cotyledons are gene- rally placed : — Now the lobes of the nelumbo arc at the most inferior part of ihe plant, and consequently m the svstem of the ascending vegetation, or of the roots. This view of regarding the neluuibo would indeed take away the means of recognising the cotyledon;* in it ; but the example of many other plants deprived of these organs, shows that they are not at ail essential to vegetation, and that the cha- racters which have been derived from them, in order to separate the vegetable kingdom into three divisions, are insufficient, and that they ought to be replaced by those which give the direction of the vessels and the medullary radii. It is also with the view of dispelling the doubts arising from the differeiU opinions of several learned botanists, that M. Poiteau has undertaken a work, which he has submitted to the Classy on the germination of the Graniinere. Bota- nists were not agreed as to th^ part of the seed ot th-, se plants which ought to be regarded as the cotvledon ; but ('bserv- -^ ing that the escutcheon, which Gyertner took for a viiellus, and M. Richard for the bodv of the radicle, was placed in tiie point where the pluniiiie and the radicle separate, 'he considers thisorgan as a true cotyledon, riiese inquiries have besides led M. Poiteau to an observation, which, al- tliough accidental, is not the less interesting, since it is connected vvith one of the pha^nomena which are n)ost ge- neral in vegetation. At the nioment when the radicle of the (jrannneae is fleveloped, it takes the figure of a(one, and .represents the principal root or tiie pivot of the other plants ; but soon afierwards, and the instant the lateral roots acouire a certain growth, this cone is obliterated and de&troyed, so that no plant of this family has a pivot : aifd as Frendh National Institute. 393 as M. Poitcau has made the same observation on several other plants with a single cotylechm, we may suppose that this substitution of" nunjerous roots and secondary to a principal root takes place, because each fasciculus ot" fibres ot" the jiionoeotyledonous plants has its proper root. This naturally recals to our minds the fine oljstiivation of M, dii Petit- Thouars on the increase in size of the dracxna, which has been discuss-jd in the reports of preceding years. ZOOLOGY, The researches of M. Cuvier respecting fossil animals have generally led him to preliminary discussions as to the species admitted by nalnraiists, and they have been al- most always the source of some valuable observations m zoology properly so called. Thus in his Memoir on the osteoloejy of the lamantin, when considerino; the orp-aniza- . . . . , . '-^ ^ tK)n of the amphibious mammiferae, he is led to separate phoci and viorsi, the dugous, the lamantins and the species described by Stelfer which' had been coiiKounded with these last animaii. The.se three genera form a tannly which u distinguished among its members by the absence of the pos- terior extremities, and by the teeth of herbivorous animals: he reduces to two the four species of lamantms esiabhshed by Buifon, and gives precise characters to those winch he admits into these different genera. In another Memoir, on cats, the same author gives the osteological character of the head of the chief species of this genus, and he gives an account of one which had not been recognised by modern naturalists. This new species has received the name of leopard, which had become syno- nymous wiih panther, for want of a precise application. It difiers from ibis last species in being of a smaller size, and having more numerr»us spots. M. GeoflVov had long formed under the name of At(^les a particular division of apes devoid of thumbs, which had been formerly confounded with the sapajons, from the catching tail which is common to all these animals. He has added two ncxv species to those wliich heh.ad already given an account of, and lias ii;iven figures and descriptions of" them. One of these only, to which he gives the name of Arachnoides, and wliich is yellow, had been descibed by Kdvvards and B.own. The other denominated E/icadrce ib entirely new; it is black with white iiair around ih.Q face. The same author has given a description of two birds, the one scarcely iinovvn^ and tht; other entirely new; this last 3<)4 French National Insiituie. last has a rescnvblance to the corvvs nudttSy and to the ff)r- vus calvvs ; hui they difl'tT suOlciently to form three di- stinct genera, wiiich M. GeoflVoy establishes by the nanie^ of cephalop/trus^ being his new species, gymnoderns, which he apphcs to the coruus luidus, aud gymnoccpJialus, by which he distinguishes the a/r/7/5 calvus. The cephalopierus is black, with a very high crest, which falls forwards upon the beak, and a kind of dewlap, also covered with feathers. The feathers of both these parts are of a metallic violet hue. The second bird, which like the above is al«o from Mex- ico, had been d-cscribed but inipcrrecfly by Marcfyrave un- der the name of cariama. M. GeolVroy from this descrip- tion had considered it as closely connected with the agami ; but now that it is to be seeii in the collection of our Mu- seum of Natural History he regards it as forming a distinct genus, to which he gives the Latin name of 7nicrodacfyli/s, Tortoises have also been one of the subjects of M. Geof- frov's researches. Having observed in Eirypt the tortoise of the Nile described by l^orskahl, he was induced to fonn a distinct genus, of all the other tortoises which like thd? latter have the extremity of the sides at liberty and a soft calipash. He calls them irionix, and has added several new species to these already known. M. Brongniart in bis trrcat work on reptiles had joined the latter to his Emydes, observing always the characters which distinguished them from the other species of this genus of which the calipash is complete and covered with scales. M. GeoffVoy, in ad- dition, joins to the genus C//e/>/s of M. Dumeril, the tor- toise descrilx-'d by Bariram under the name of tortoise with large soft scales, and disco veu.d by this traveller in North Anrerica. These animals present a striking example of the progress of zoology oF late yeais. The number of tortoises known 20 years ago was scarcely 30, and now it has been at least doubled. This among other circumstances has been com- municated to us by a work of M. Sweiger, in which he has undertaken to give a general monographv of all the tor- toises. This fine work, accompanied by precise descriptions of a very extensive synonymy and embellished with figures excellently drawn bv M. Oppel, has been submitted to the in!>pccti(m of the Institute, and highly approved of. The class of fishes has also been enriched with many new species. Messrs. Hisseau and Delaroche, v»'ho have particularly directed their attention to this branch of zoo- losy, have coinn)uniealed iheij obsi^rvations to u»» 'J'hose French National Instltuie. 895 of tb€ former hav€ been made on fishes in the Gulf of Nice, and those of the latter were maxle on the fish<.*s in the sea around the Balearic Islands. But the labours of these naturalists have not been -confined to bringing new species to light :— from their accounts there are grounds for supposing that each species of fish, like terrestrial animals, has a region, in tbe midst of which its existence is circum- scribed, and that those of the south are never met with in the north, and vice versa. M. Risseau, however, has dis- covered in the Mediterranean some fijhes which had not hir iherto been found except in the Indian or in the Northern 'seas. M. Delaroche has made some interes'ting researches as to the depth at which each species of fish lives habitually, as to the modes of fishing, and on the subject of the swim- ining-bladder. PHYSIOLOGY. Physiological experiments of all others are those which require most leisure and patience, while the rigorous exacti- tude so important and necessary in the sciences is more xiifficult of attainment in physiology than in any other branch of experimental philosophy. Humboldt, however, while occupied on a voyage in which obstacles and danger^ were daily increasing, directed his attention to some deli- cate experiments on several of the phasnomena of life. He has communicated the researches which he made in America on tb» respiration of the crocodile with the sharp beak : he was led to ascertain *' that this animal, nolwith- , standing the volume of its bronchiae and the structure of its pulmonary celluli, suffers in an air which is not re- newed ; that its respiration is very slow : — in the space of lan hourand 43 minutes, a young crocodile, three decimetres in length, took up only about 20 cubic centiemcs of oxy- gen from the surrounding atmosphere." Since his return to France, M. Humboldt, in conjunction with M. Provencal, has made some additional inquiries into ihe respiration of fishes. The experiments of these gentlemen, which are numerous, and remarkable for their accuracy, have led them to very important results. The experiments of Spallanzani, and of our colleasjuc, liad demonstrated that it is not by decomposing water that fishes breathe, as some naturalists thought ; but by taking up the oxygen dissolved in this liquid, or by corning to the surface ot the water they collect it immediately from the atii^osphere. To these observations all our knowledge pi\ altering the- same. May 2. To William Clerkj esq. advocate, for hrs method for pre- venting smoke, dust, and the danger of tire, and for in- ci'easing and regulating heat from stoves and chimney fire- places for heating rooms^ halls, passages, and stair- cases in public-buildings and daelling-houses, and all other apart- menis where regulated heat and cleanliness are desirable,, without obstructing the viewof the burning fuel. May 2. To Sebastian P>ard, of Great Marlborough Street, in the county ot Middlesex, for certain improvements on piano- fortes and harp. May 2. To John Maiben, of Perth, in the county of Perth, Sadler and ironmonger, for certain apparatus for makiii/*- carbonated hydrogen gas from pit- coal, and for using the same for lighting njills, factories, houses, lamps, &.c. the lights being regulated by means of syphons. May 2. METEOnO- 40O Mcteorohgy* METEOROLOGICAL TABLE, Br Mr^ Carey, of the StraiND, For May 1810. Thermometer. | Height of the Barom. Inches. D?vs of Mouth. § 2. .J . Weather. April i>7 44 .58^ 47° 30-16 67 Fair 28 47 64 48 •14 74 Fair iXJ 48 69 52 •05 76 Fair 30 51 68 54 29-98 86 Fair May 1 49 67 44 •85 68 Fair 2 44 52 4ey •80 45 Cloudv 3 44 49 45 •70 29 Cloudv 4 45 47 40 •76 26 Cloudy 5 40 51 36 •80 36 Fair tJJ 40 50 40 •80 35 Fair f 71 41 48 46 '55 0 Rain 8[ 41) 62 50 •67 51 Fair 9i; 52 61 50 •80 40 Cloudv I0| 52 65 51 •98 42 CU)udy 11 4T 55 42 30-08 43 Fair 12 42 56 45 29-97 41 Cloudy 13 50 47 47 •72 22 Cloudy 14 49 59 49 •60 51 Fair 15 49 55 50 '35 15 Cloudy 16 48 61 49 '45 25 Fair 17 49 54 52 •46 0 Rain IS 40 43 44 •56 0 Rain 19 42 59 44 •98 41 Fair 20 45 60 48 '95 47 Fair 21 57 61 52 •6i 40 Fair 22 54 60 49 •87 37 Showerv 23 50 60 48 30-10 42 Fair 24 49 61 47 •13 76 Fair 25 47 60 49 •05 46 [Fair 26 46 68 47 29-93 61 [Fair ■ N.B. The Bnrometcr's height is taken atone o'clock. ERRATUM. Page 303, of the present volume— Article Royal Society, Mr. Groombridge*» formula— for " tar.g. 2 — .'i-.'^G r" read <* tang. Z— 33G r"— — Z representing Zenith distance. [ 401 ] LXI. The Bakerian Lecture for I8O9. On some new Electrochemical Researches on various Objects^ particU' larly the inetaliic Bodies , from the Alkalies ^ and Earths y and on some Combinations of Hydrogen. By Hum- phry Daw, Esq. Sec, R,S. F,R,S. £. M.R.LA.* I. Introduction* X HAVE employed no inconsiderable portion of the time that has elapsed, since the last session of the Royal Society, in pursuing the train of experimental inquiries on the ap- plication of Electricity to Chemistry, the commencement and progress of which this learned body has done me the honour to publish in their Transactions. In this communication I shall, as formerly, state the re- sults. I hope they will be found to lead to some views, and applications, not uncormected with the objects of the Bakerian lecture : and though many of them are far from having attained that precision, and distinctness, which I could'wish, yet still I flatter myself, that they will afford elucidations of some important and abstruse departments of chemistry, and tend to assist the progiress of philoso- phical truth. II. Some new Experiments on the Metals from the fixed Alkalies, In the paper in which I first made known potassium and sodium to the Royal Society, I ventured to consider these bodies according to the present state of our know- ledge, asundecompounded, and potash and soda as metallic oxides, capable of being decomposed and recomposed, like other bodies of this class, and with similar phsenomena. Since that time, various repetitions of the most obvious of the experiments on this subject have been made in dif- ferent parts of Europe. The generality of enlightened chemists have expressed themselves satisfied both with the experiments, and the conclusions drawn from them : but as usually happens in a state of activity in science, and when the objects of inquiry are new, and removed from the common order of facts, some inquirers have given hy- pothetical explanations of the phaenomena, different from those I adopted. MM. Gay Lussac and Thenard, as \ have mentioned • from JPhilospphical Transactions for 1810, Parti. Vol. 35. No, 146. June 1810. C c on 40-2 On some new Eleclrochemical Reseafches on a former occasion, suppose potassium and sodium to he compounds of potash and soda with hvdrogen; a similar opinion seems to be entertained by M. Ritter. M. Curau- dau* aflccts to consider ihem as combinations of charcoal, or of charcoal and hydrogen, with the alkalies; and an Inquirerf in our own country regards them as composed of oxi/gi'?i and Jiydrogen, I sliall examine such of those notions only as have been connected with experiments, and f shall not occupy the time of the society with 'any criticisms on matters of mere speculation. In iiw two last communications, I have given an account of various experiments on the action of potassium upon ammonia, the process from which MM. Gay Lussac and Thcnard derive their inferences. At the time that these papers were written, I had seen no other account of the experiments of the French chemists, than one given in a number of the Moniteur ; and as this was merely a sketch, which I conceived might be imperfect, I did not enter into a minute examination of it. I have since seen a detail of their inquiry in the second volume of the Mem. d'Arcueil, a copy of which M. Berthollet has had the goodness to send me, and the publication of which is dated June 7? 180^: and from this detail, it seems that they still retain their opinion; but upon precisely the same grounds as those to which I have before referred. That no step of the discus- sion mav be lost to the society, I shall venture to state fully their meihod of operation, and of reasoning. They say, that they heated potassium J in ammonia, and they found that a considerable quantity of ammonia was absorbed; and hydiogen produced; and that the -potassium became converted into an olive- coloured fusible substance; by healing this substance strongly, they ob- tained three-fifths of the ammonia again, two- fifths as ammonia, one- fifth as hydrogen and nitrogen; by add- ing a little water to the residuum, they procured the re- iiiainhig two-fifths, and found in the vessel in which the operation was carried on, nothing but potash. — Again, it is stated, that by treating a new quantity of metal with the ammonia disengaged from the fusible substance, they again obtained hydrogen, and an absorption of the annnonia; and by carrying on the operation, they affirm that they * Journal de Physique^ Tune 1808. + Nicholson's Journal, Au£^st 1809, p, 258, \ Mf/n. (V^rcudl, torn. ii. page 309. can on various Ohject$, 403 can procure from a given quantity of ammonia, rhore than its volume of hydrogen. Whence, they ask, can the hydrogen proceed ? — Shall it be admitted that it is from the ammonia? But this, say they, is impossible; for all the ammonia is reproduced. It must then conie from the water which may be supposed to be in the ammonia, or from the metal itself. But the experiments of M. BerthoUet, jun. prove that ammonia - does not contain any sensible quantity of water. There- fore, say they, the hydrogen gas must be produced from the metal; and as, when this gas is separated, the metal is transformed into potash, the metal appears to be nothing more than a combination of hydrogen, and that alkali. It is obvious, that even supposing the statement of these gentlemen correct, their conclusions may easily be contro- verted. They affirm that all the ammonia is reproduced; but they do not obtain it without the addition of water. And of the oxygen which this would give to the potas- sium, and of the hydrogen which it might furnish, to re- produce the ammonia, they take no notice. I have shown, by numerous experiments, many of which have been repeated before members of this society, that the results obtained, by applying heat to the fusible sub- stance, are very different from those stated by the ingenious French chemists, when the operations are conducted in a refined and accurate manner. In proportion as more precautions are taken to prevent moisture from being communicated to it, so in proportion is less ammonia regenerated ; and I have seldom obtained as much as yV ^^ ^^^ quantity absorbed. And Ihave never procured hydrogen and nitrogen, in the proportions in which they exist in ammonia ; but there has been always an excess of nitrogen. The processes which I have detailed in the last Bakerjan lecture, and in the appendix to it, show this ; and they likewise show that a considerable quantity of potassium is always revived. I have lately performed the experiments^ in a manner which I proposed, page 458 of the last volume of the Transactions [Phil. Mag. vol. xxxiv. p. 344.] and ^the re- sults have been very satisfactory; as far as they relate to the question of the nature of potassium. I employed a tube of platina bored from a single piece, "Which having a stop-cock and adaptor of brass, connected with the mercurial apparatus, could be used as a retort; the C c 2 potassium 404 Oh some new Eleclrochemical Researches potassium was employed in quantities of from three to four grains, and the absorption of the ammonia conducted as usual, in a retort of glass free from metallic oxides; and in a tray of platina. In some of the processes, in which the heat was rapidly applied, some of the gray matter, which I have formerly described as a pyrophorus, passed over in distillation, and in these cases there was a considerable deficiency of hy- drogen, as well as nitrogen, in the results of the experi- ment ; but when the heat was very slowly raised, the loss was much less considerable, and in several cases I ob- tained more than four- fifths of the potassium which had been employed ; and very nearly the whole of the nitrogen, existing in the ammonia that had been acted upon. I shall give an account of one process, conducted with scrupulous attention. The barometer was at 302'"', ther- mometer at 54^ Fahrenheit. Three grains and a half of potassium were heated in 12 cubical inches of ammo- nia, 7*5 were absorbed, and 3*2 of hydrogen evolved. The fusible substance was not exposed to the atmosphere, but was covered with dry mercury, and immediately intro- duced into the tube; which, with its adaptors, was ex- hausted, and filled with hydrogen. They contained to- gether -jSg- of a cubical inch. The heat was very slowly applied by means of a fire of charcoal, till the tube was ignited to whiteness. Nine cubical inches of gas were given off, and ? of a cubical inch remained in the retort and adaptors. Of the 9 cubical inches, ^ of a cubical inch was ammonia, 10 measures of the permanent gas, mixed with 7*5 of oxygen, and acted upon by the electrical spark, left a residuum of 7'5. The quantity of potassium formed, _ was such as to generate by its action upon water three cubical inches and -p^-g- of hydrogen gas. Now if this experiment be calculated upon, it will be found, that 7*5 — •2= to 7*3 of ammonia, by its electrical decomposition, would afford about 13*1 of permanent gas, containing 3*4 of nitrogen, and 9*7 of hydrogen. But the 3*2 cubical inches of hydrogen, evolved in the first part of the process, added to the 5*8 evolved in the second part of the process, ---9; and the nitro'gen in the 8*8 cubical inches of gas (or the 9 — '2 of ammonia) will be about 3, and if we estimate '34 of hydrogen, and '16 of nitrogen, in the *5, remaining in the retort; there will be very little difference in the results of the analysis of ammonia by electricity, and by the action of potassium ; aud calculating upon on various Oljects, 405 upon the -^^ of hydrogen pre-existing in the lube and adaptors, the loss ojf' hydrogen will be found proportionally rather greater than that of nitrogen. In another experiment in which three grains of potassium were employed in the same manner, 6*78 cubical inches of ammonia were found to be absorbed, and 2*48 of hydrogen only iienerited. The distillation was performed, the adantors and tube heing full of common air: 8 cubical inches of gas were pr«;;aced; and there must haife remained in the lubes and adaptors, the same quantity of residual air as in the process last described. The 8 cubical inches of gas contained scarcely -S- of a cubical inch gf ammonia; and the unabsorbable part de- tonated with (^xvgcn, in the proportion of 1 1 to 6, gave a residuum of 7'5. — The barometer was at 30*2'"', thermo- meter at 52^ Fahrenheit. Dr. Pearson, Mr, Allen, and Mr. Pepys were present during thq whole of these opera- tions, and kindly assisted in the progress of them. Now 6*78 — '4 of ammonia = 6*38, and this quahtity of gas decomposed by electricity, would afford 11*4 of per- manent gas, consisting of 2*9 nitrogen, and 8*5 hydrogen; but there are produced in this experiment,, of hydrogen, 2*48 in the first operation, and 4*28 in the second, and considering the nitrogen in the permanent gas as 3*32, '8 must be subtracted for the common air; which would give 2*52 for the nitrogen generated; and to these must be added, the quantity of hydrogen and nitrogen in the tubes and adaptors. The quantity of potassium regenerated was sufficient to produce 2*9 cubical inches of hydrogen. In all experiments of this kind, a considerable quantity of black matter separated, during the time the potassium in the tube was made to act upon water. This substance was examined. It was in the state of a fine powder. It had the lustre of plumbago, it was a con- ductor of electricity. When it was heated, it took fire at a temperature below ignition ; and after combustion, no- thing remained but minutely divided platiiia. I exposed some of it to heat in a retort containing oxy- gen gas ; there was a diminution of the gas; and a small, quantity of moisture condensed on the upper part of the retort, which proved to be mere water. I made two or three experiments, with a view to ascer- tain the quantity of this substance formed, and to deter- mine more fully its nature. I found that in the process in which from three to four grains of potassium were made C c 3 to 4o6 On some neiv Electrochemical Researches to act upon ammonia in a vessel of platina, and afterwards distilled in contact with platina, there were always from four to six grains of this powder formed ; but I have adr vanccd no further in determining its nature, than in as- certaining, that it is platina combined with a minute quantity of matter, which affords water by combustion iia oxygen. In the processes on the action of potassium and ammo- nia, in which iron tubes were used, as appears from the experiments detailed in the last Bakerian lecture, and the appendix, there is always a loss of nitrogen, a conversion of a portion oF potassium into potash, and a production of hydrogen. When copper tubes are employed, the hydro- gen bears a smaller proportion to the nitrogen 3 ^nd more potassium is revived. In these experiments, in which platina has been used, there is little or no loss of potassium or nitrogen 5 but ^ loss smaller or greater of hydrogen. It will be asked. On what do these circumstances de- pend ? Does the affinity of certain metals for potassium prevent it from gaining oxygen from ammonia, and do platina and copper combine with a small quantity of hy- drogen, or its basis ? Or are there some sources of inac- curacy in those processes, in which nitrogen has appeared to be decomposed ? The discussion of these difficult pro- blems will be considered in that part of this lecture, in which the nature of ammonia will be illustrated by some new experiments. The object of the present part of the inquiry is the demonstration of a part of chemical doctrine, no less important and fundamental fo a great mass of rea- soning, namely, that by the operation of potassium upon ammonia, it is not a metallic body that is decompounded but the volatile alkali, and that the hydrogen produced does not arise from the potassium, as is asserted by the French chemists, but from the ammonia, as I have always sup- posed ', the potassium in the most refined experiments is recovered, but neither the ammonia nor its elements can be reproduced, except by introducing a new body, which contains oxygen and hydrogen. I have niade an experiment upon the action of sodium on ammonia, with the same precautions as in the experi- ments just detailed, a tray, and the same tube of platina being employed. 3-_3_. grains of sodium I found absorbed 9*1 of ammonia, and produced about 4'3 of hydrogen, and the fusible sub- stance, which was very similar to that froni potassium, distilled. GTi various Objects, 407 tlistillecl, did not give off* -g-^ of the ammonia that had dis- appeared; and this small quantity I am inclined to attri- bute to the presence c^f moiaiure. The permanent gas pro- . duced, equalled twelve cubical inches, and, by detonatiou with oxygen, proved to consist of nearly two of hydrogen to one of nitrogen. Sodium was regenerated, but an ac- cident prevented me from ascertaining the quantity. Whoever will consider with attention, the mere visible phaenomena of the action of sodium on ammonia, cannot, I conceive, fail to be convinced that it is the volatile alkali, and not the metal, which is decompounded in this process. As yodium does not act so violently upon oxygen, as potassium ; and as soda docs not absorb water from the atmosphere, with nearly so much rapidity as potash, so- dium can be introduced into annnonia, much freer froni moisture, than potassium. Hence, when it is heated in ammonia, there is no elFervesccnce, or at least one scarcely perceptible. Its tint changes to bright azure, and from bright azure to olive green, it becomes quietly and silently converted into the fusible aubstance, which forms upon the surface, and then flows ofif into the tray. It emits no elastic fluid, and gains its new form, evidently, by combin- ing with one part of the elementary maltejr of ammoni.i, whilst another part is suffered to escape in the form of hydrogen. It will not be necessary for me to f nter, into a very mi- nute experimental examination oFihe opinion of M. Curau- dau, that the metals of the alkalies are composed of the alkalies merely united to charcoal ; the investigation upon which he has fojand.ed his conclusions, is neither so refined, nor so difficult, as that which has been ju'st examined. This gentleman has been misled by the existence of char- coal, as an accidental constituent in the metals he employed, in a manner much more obvious, than that in which MM. Gay Lussac and Thenard have been misled by the moisture which interfered with their resuUs." M.Curaudau states, that when sodium is oxidated, carbo- nic acid is formed. This I have never found to be the case, except when the sodium was covered by a film oF naphtha. I burnt two grains of sodium in eight cubical inches of oxvgen : nearly two cubical inches of oxygen were absorbed, and soda in a state of extreme dryness, so that it could not be liquefied by. a heat below redness, formed. This soda did not give out an atom of carbonic acid, during its so- lution in muriatic acid. Three grains of sodium were made to act upon water; they decomposed it with th^ C c 4 phsenomenji 408 On some new Electrochemical Researches phaenomena which I have described in the Bakerian lecture for I807. Nearly six cubical inches of hydrogen were produced. No charcoal separated; no carbonic acid was evolved, or found dissolved in the water. Whether the metals of potash or soda were formed by electricity, or by the action of ignited iron on the alkalies, the results were the same. When charcoal is used in experiments on po- tassium or sodium, they usually contain a portion of it in combination ; and it appears from M. Curaudau's method of decomposing the alkalies, that his metals must have been carburets not of potash and soda, but of potassium and sodium. M. Ritter's argument, in favour of potassium and sodium being compounds of hvdrogen, is their extreme lightness. This argument I had in some measure anticipated, in my paper on the decomposition of the earths ; no one is more easily answered. Sodium absorbs much more oxygen than potassium, and on the hypothesis of hycjrogenation, must contain much more hydrogen ; yet though soda is said to be lighter than potash, in the proportion of 13 to 17 nearly*, yet sodium is heavier than potassium in the pro* portion of 9 to 7 at least. On the theory which I have adopted, this circumstance is w^hat ought to be expected. Potassium has a much stronger affinity for oxygen than sodium ; and must con- dense it much more, and the resulting higher specific gra- vity of the combination is a necessary consequence. M. Ritter has stated, that of all the metallic substances he tried for producing potassium by negative Voltaic elec- tricity, tellurium was the only one by which he could not procure it. And he states the very curious fact, that when a circuit of electricity is completed in water, by means of two surfaces of tellurium, oxygen is given off at the posi- tive surface, no hydrogen at the negative surface, but a brown powder, which he regards as a hydruret of tellurium, is formed and separates from it; and he conceives that the reason why tellurium prevents the metallization of potash is, that it has a stronger attraction for hydrogen than that alkali. These circumstances of the action of tellurium upon waler, are so different from those presented by the action of other metals, that they can hardly fail to arrest the at- tention of chemical inquirers, i have made some experi- nients on the subject, and on the action of tellurium on ♦ Hasscrtfratz, Annal. de Chim. tome xxviii. p. 11. potassium, on various Objects. 409 potassium, and T find that instead of proving that potassium IS a compound of potash and hydrogen, they confirm the idea of its being as yet like other metals undecompounded. When tellurium is made the positive surface in water, oxygen is given off; when it is made the negative surface, the Voltaic power being from a battery composed of a number of plates exceeding 300, a purple fluid is seen to separate fioin it, and diffuse itself through the water; the water gradually becomes opake and turbid, and at last de- posits a brown poXvder, The purple fluid is, I find, a so- Kuiou of a <:omp()und of tellurium and hydrogen in water; which, in being diffused, is acted upon by the oxygen of the common air, dissolved in the water, and gradually loses a part of its hydrogen, and becomes a solid hydruret of tellurium. The compound of hydrogen and tellurium pro- When these metals were gently heated in a retort of green glass, filled with hydrogen gas, they combined with great energy, producing most vivid heat and light, and they composed an alloy of a dark coj:)- per hue, brittle, infusible at a heat below redness, and possessing a crystalline fracture. When the tellurium was in excess in this mixture, or even nearly equal to the po- tassium in quantity, no hydrogen was evolved by the action of the alloy upon water; but the compound of telluretted hydrogen and potash was formed, which remained dis- solved in the fluid, and which was easily decomposed by an acid. The very intense affinity of potassium and tellurium for each other, induced me to conceive that the decomposition of potash might be easily effected, by acting on the oxide of tellurium and potash at the same time, by heated char- coal; and [soon proved that this was the case. About 100 grains of oxide of tellurium, and £>0 of potash, were mixed with 12 grains of well burnt charcoal in powder, and heated in a green glass retort ; before the retort be- came red there vvas a violent action, much carbonic acid was given off, a vivid light appeared in the retort, and there was found in it the alloy of tellurium and potassium. In attempting to reduce some oxide of tellurium by char- coal, which Mr. Hatcheit had the kindness to give me for the purposes of these experiments, and which must have btien precipitated by potash, or from a solution in potash, I found that a sufficient quantity of alkali adhered to it, even after it had been well washed, to produce an alloy of potassium and tellurium ; but in this alloy the potassium was in very small quantity. It was of a steel gray colour, very brittle, and much more fusible than tel- lurium. i shall not arrest the proc:ress of discussion, by entering at present into a minute detail of the properties of the aeriform compound of tellurium and hydrogen; I shall mention merely some of its. most remarkable qualities, and ao-encies, which, as will be shown towards the close of this paper, tend to elucidate many points immediately connected with the subject in question. The compound of tellurium and hydrogen is more analogous to sulphuret- ^J hydrogen, than to any other body. The smell of the two on various Ohjecls* 411 two substances is almost precisely the same*. Its aqueous solution is of a claret colour; but it soon becomes brown, and deposits tellurium, by exposure to air. When disen- gaged from an alkaline solution by muriatic acid, it reddens moistened litmus ; but after being washed in a small quan- tity of water, it loses this property ; l)ut in this case like- wise it is partially decomposed by the air in tlie water; so that it is not easy to say, whetlier the power is inherent in it, or depends upon the diffusion of a small quantity of muriatic acid through it. In other respects, it resembles ~ a weak acid, combining with water, and with the alkalies. It precipitates most metallic solutions. It is instantly de- composed by oxymuriatic acid, depositing a film, at first metallic, but which is SQon converted into muriate of tellurium f. As arsenic has an affinity for hydrogen, it occurred, ta me as probable, that it would present some pheenomena analogous to those offered by tellurium, in its action upon potassium, and in its operation upon water, when electri- fied. Arsenic made the negative surface, in water, by means of a part of the new battery, containing 6()0 double plates, became dnrk-coloured, and threw down a brown powder j but it likewise gave off a considerable quantity of inflam-r mable gas. Arsenic negatively electrified in a solution of potash, likewise afforded elastic matter ; but in this case the whole .solution took a deep tint of brown, and was pellucid; but it became turbid, and slowly deposited a brown powder, by the action of an acid. When arsenic was made the negar * In some experiments, made on the action of tellurium and potassium, ia the laboratory of my frieiid John George Children, esq. of Tunbridge, in which Mr. Children, Mr. Pepys, and Mr. Warbutton co-operated, th^ ana- logy between the two substances struck us so forcibly, as for some time to induce us to conceive that tellurium mi«;ht contain sulphur, not manifested in any other way but by the action of Voltaic electricity, or by potassium ; and some researches made upon the habitudes of difFerent metallic sul- phurets,at the Voltaic negative surface, rather confirmed the suspicion ; for most of the sulphurets that we tried, which were conductors of electricity, absorbed hydrogen in the Voltaic circuit. Tlic great improbability, how-r ever, of the circumstance that sulphuric acid, or sulphur in any state of oxy- genation could exist in a metallic solution, which was not manifested by the action of barytes, induced me to resist the inference ; and further researches, made in the laboratory of the Royal Institution, proved that the substance jn question was a new and singular combination. + From the results of one experiment which I tried, it seems that tel- lurium, merely by being heated strongly in drv hydrogen, enters into com- bination with it. An accident prevented me from ascertaining whether the fomp'ound so formed, is exactly the same as that described m the text. ' tivp 413 On some new 'Electrochemical Researches live surface, in contact with solid potash, an alloy of arsenic and potassium was formed of a daik gray colour, and per- fectly metallic ; it gave off arseniuretted hydrogen by the action of water with inflammation, and deposited a brown powder. When potassium and arssenic * were heated together in hydrogen gas, they combined with such violence as to pro- duce the phaenomena of inflammation, and an alloy was produced of the same kind as that formed by means of the Voltaic battery. As tellurium and arsenic both combine with hydrogen, it appeared to me probable, that by the action of alloys of potassium, with tellurium and arsenic, upon ammonia, some new phsenomena would be obtained, and probably, .still further proofs of the decomposition of the volatile al- kali, in this process afforded ; and this T found was actually the case. When the easily fusible alloy of tellurium with potas- sium, in small quantity, was heated in ammonia, the sur- face lost its metallic splendour, and a dark brown matter was formed, which gave ammonia by exposure to air; and the elastic fluid, which was generated in this operation, consisted of four-sixths nitrogen, instead of being pure hydrogen, as in the case of the action of potassium alone. The alloy of arsenic and potassium, by its action upon ammonia, likewise produced a gas which was principally nitrogeA ; so that if it be said that the metai, and not the volatile alkali, is decomposed in processes of this kind, it must be considered in some cases as a compound of nitro- gen, and in others a compound of hydrogen ; which are contradictory assumptions. None of the chemists who have speculated upon the imaginary hydrogenation of potash, as far as my know- ledge extends, have brought forward any arguments of analysis, or synthesis. Their reasonings have been found- ed, either upon distant analogies, or upon experiments in ♦ In reasoning upon the curious experiment of Cndet, of the production of a volatile pvrophorusby the distillation of acetite of porash, and white oxide of arsenic, FourcroyConnais Chem. torn viii. p. 197,1 C(^nceivcd it probable, that this pyrophorus was a volatile alloy of potassium .iiid arsenic. But from a repetition of the process I find, that though potash is decompounded in this operation, yet that the volatile substance is not an alloy ot potassium, but contains charcoal and arsenic, probably with hydrogen. The galses not absorbable by water given ofF in this operation, are peculiar. 1 heir smell is intensely foetid. They are inflammable, and seem to contain char- coal, arsenic, and hydrogen: whether ihey are mixtures of various gases, or a single compound, I am not at present able to decide. which on various Objects, *15 which agent, which they did not suspect were concerned. No person, I believe^ has attempted lo show that when potassium or sodium is burnt in oxygen gas, water is form- ed, or that water is generated when potassium decomposes any oi the acids *j and no one has been able td form potas- sium, by combining hydrogen with potash. I stated itt the Bakerian lecture for 1807, that when potassium and sodium were burnt in oxygen gas, the pure dkaVies wqtg formed in a state of» extreme dryness; and that 100 parts of potassium absorb about 18 parts of oxygen, and iOO parts of soda about 34 parts. Though, in the experiments from which these deductions were made, very small quan- tities only of the materials were employed ; yet still, from frequent repetitions of the process, I hoped that they would approach to accuracy ; and I am happy to find that this is the case; for the results differ very little in some ex* periments which I have made upon c msiderable portions of potassium and sodium, procured by chemical decom- position. When potassium is burnt in trays of platina, in oxygen gas that has been dried by ignited potash, the absorption of oxygen is about i^ of a cubical inch for every grain of the metal consumed ; and when sodiuiii is burnt in a si- milar manner, about a cubical inch is taken up for every grain f. The alkalies so formed, are only imperfectly fu- sible at a red heat; and do not, like the easily fusible alka- lies, give indications of the presence of moisture. M. D'Arcet has shown by some very well conducted inquiries, that potash and soda J, in tlicir common state, contain a considerable proportion of water; and M. Ber- * When in October 1807, I obtained a dark-coloured combustible sub- stance from boracic acid, at the ii'eg-ative pole m the Voltaic circuit, I con- cluded that tlie acid was probably decomposed, according to the common law of electrical decomposition, lnMar:li 1308. I made turther experi- ments on this substance, and ascertained thai it produced acid matter by- combustion; and I announced the decomposition in a public lecture de- livered in the Royal Institution March 12. Soon after I heated a small quantity of potassium, in contact with dry boracic acid, no water was given off in the operation, and I obtnined the same substance as I had procured by electricity. MM. Gay Lussac and Thenard have likewise operated upon boracic acid, by potassium, and they conclude that they have decompounded it; but this does not follow from their theory, unless they prove that water is given off in the operation, or combined with the borate of potash: the legitimate conclusion to be drawn from the processes, on their hypothesis, was, that they had made a hydruret of boracic. acid. f The quantities of gas given out by the operation of water, are in a si- milar ratio. See page 43 of the last Bakerian lecture [PhiJ. Mag. vol. xxxiii. p. 432,] and page 26 of this paper [p. 407 and 408 preceding.] I Aanales de Chimie, Nov. 1808, page l75. thollet 414 On sorne Jietv Etecti'dchemicdt Researches thollet concludes, that 100 parts of potash, that have be^fl kept for some time in fusion, contain 13*89 parts of watcr^ which is lost when the alkali enters into combination with muriatic acid; and the same sagacious observer, from some very minute experiments, infers, that jnuriate of potash^ which has been ignited, contains in the 100 parts 6669 potash, and 33-34 muriatic acid, a determination which diflfers very little from that of Bucholz. To determine the relation of the dryness of the potash, formed from potassiiim, to that which has been considerei as freed from the whole or the greatest part of its water, in muriate of potash, I made several experiments. I first at- tempted to convert a certain quantity of potassiurrt into J)otash, upon the surface of liquid muriatic acid ; but in this case the heat was so intense, and hydrogen holding potassium in solution was disengaged with so much ra- pidity, that there was a considerable loss of alkali ; yet even under these circumstances, I obtained from ten parts of potassium 17*5 of dry muriate of potash. The most successful and the only mode which I employed, that can be entirely depended upon, was that of converting potas- sium into muriate of potash, in muriatic acid gas. I shall give the results of two experiments made in this manner: Sve grains of potassium inserted in a tray of platina, were made to act upon 19 cubical inches of muriatic acid gas> that had been exposed to muriate of lime; by the appli- cation of a gentle heat, the potassium took fire, and burnt with a beautiful red light*; and the whole mass appeared in igneous fusion ; a little muriate of potash in the state of awhile powder, sublimed and collected in the top of th«? vessel in which the experiment was made. Nearly 14 cubical inches of muriatic acid gas were absorbed, and about five of hydrogen were produced. The increase of weight of the tray was about 4*5 grains; and it did not lose any weight. by being ignited. The second experiment was conducted with still more attention to minuteness. Eight grains of potassium were employed ; above 22 cubical inches of muriatic acid gas were consumed ; the potassium burnt with the same bril- liant phsenomena as in the last experiment, and the in- crease of weight of the tray was 6\ grains. The muriate of potash was kept for some minutes in fusion in the tray^ * As a retort exhausted of common air was used, the small qunntity of residual common air may have been connected with this vividness of com- bustion, . . till on various Objects, 4 1 5 till a white fume began to rise from it, but it did not lose the Vo- o^ ^ grain in weight. After the muriate of potash had been washed out ot ihe tray, and it had been cleaned and dried, it was found to have lost about a third of a grain, which was platina in a metallic state, and that had alloyed with the potassium where it was in contact with the tray, during the combustion. There was no appearance of any water being separated in the process. A little mu- riate of potash sublimed ; this was washed out of the re^ tort, and obtained by evaporation : it did not equal l of a grain. Now if the data for calculation be taken from this last experiment, 8 grains of potassium will combine with 1*4 grains of oxygen, to form 9*4 grains of potash, and 6-6 — 1*4 = 5*2, the quantity of muriatic acid combined with the potash, which would give in the 100 parts in muriate of potash, 33*6 of acid, and 64-4 of potash; but 35*6 of murialic acid, according to M. Berthollet's estimation, would demand 71*1 of alkali, in the state of dryness in which it exists in muriate of potash, and 71*1-— 64*4 =: fi*7— so thatthe potash taken as a standard by M. Ber- thollet, contains at least 9 per cent, more water ' than th.at existing in the p©tash formed by the combustion of potas- sium in muriatic acid gas, which consequently may with much more propriety be regarded as the dry alkali*.' After these illustrations, I trust the fonncr opinions which I ventured to bring forward, concerning the me- tals of the fixed alkalies, will be considered as accurate, and that potassium and sodium can with no more pro- priety be considered as compounds, than any of the common metallic sulstances; and that potash and soda, as formed by the combustion of the metals, are pure me- tallic oxides, in which no water is known to exist. Thess conclusions must be considered as entirely inde^ pendent of hypothetical opinions, concerning the existence of hydrogen in combustible bodies, as a common principle of inflanmiability, and of intimately cotnh'ned water, as an essential constituent of acids, alkalies, and oxides : this part of the inquiry I shall reserve for the conclusion of the lecture, and I shall first consider the nature of the metal of ammonia, and the metals of the earths. [To be continued.] * Consequently M. Berthollet's fused potash must contain nearly 23 per cent, of water. From my own observations I am inclined to believe, that potash kept for some time in a red heat contains J6 or 17 percent, of wa- ter, taking the potash formed by the combustion of potassium as the dry standard. LXIf. Oh^ f 416 ] LXir. Observations respecting a New Scale for (he Tlief^ mometer. By Richard Walker, Esq, of Oxford. JL HERE are four different thermometers in use at this lime, viz. Fahrenheit's, Reaumur's, Celsius's, and De risle's. Fahrenheit's scale, which is used in Great Britain, has the zero, or commencement of the scale, placed at 32 degrees be- low the freezing point, and 2 1 2 is the boiling point of water* Reaumur's, or the French scale, modified by De Luc, in which the 0 is placed at the freezing point, and from thence to the boiling point are 80 degrees*. Celsius's scale is used in Sweden; in this 0 is placed at the freezing point, and from thence to the boiling point are 1 00 degrees. De risle's scale is used in Russia; in which 0 is placed at the boiling point of water, and the freezing point is 150. With respect to Fahrenheit's scale, it may be considered, now, as having no foundation whatever in any principle, and is in fact upon that account universally disapproved of, and evidently upon (he decline. Reaumur's scale, and others in which the freezing point of water has been adopted for placing the O, or com- mencement of the scale, has been hitherto deemed the least objectionable, on account of its being an invariably fixed point. In the construction of thermometers two fixed points are required : accordingly, the scales of all thermometers have hitherto been, and probably ever will be, adjusted by- means of the freezing and boiling points of water; the latter, as is well krvown, being an equally fixed point with the former, under certain circumstances well known to the philosopher and the artist. The freezing and boiling points of water, then, may be considered as applicable only to the due arrangement of the proportions and precision of a thermometrical scale, and consequently either of them unfit for the place of com- mencement of it : hence the place where 0 should be placed is yet a desideratum. Considering the thermometer as a measure of heat, leav^ ing the negative term cold out of the question, the pro- * A thermometer called the centigrade has lately been hitroduced in> France, which is in fact uo other than that of Celsius,^ with the addition of decimal divisions. per Observations on a New Scale for the Thermometer, 417 per place for O would undoubtedly be that point at which heat commences ; but the physical causes, which are known to exist, to prevent that point being ever ascertained, ex^ elude entirely the hope ot" fixing it there ji, to say nothing of the inconvenience which must arise trOm the scale be- ing incumbered with a multiplicity of figures, at that part which is most familiar and in most frequent use. Hence we are under the necessity here, as in many other instances, of uj;ing the positive and negative signs. Having been for a v^ery long time engaged in thermome- trical experiments and observations, — the imperfection of all the scales in use, and the consequent dissatisfaction of V/ario»us persons respecting them, frequently occurred to me; and it is long since that I was impressed with the opinion, strengthened by ihat of several of my friends, of the pre- ference which was due to the one I am now about to men- tion. It has been ascertained by physiologists as a fact, and of which I have perfectly satisfied myself, by repeated ex- periments on others as well as myself, that 62 of Fahren* heit is that point at which the human body in a state of health is unconscious of either heat or cold, that is, in a state of rest, or when free from any considerable bodily exertion ; and this is really the case at all seasons of the year, in this climate, and probably in all other climates; for the temperature of the human body, or blood heat, as it is called, is determined every where to be 98, and it has been found that the vital functions have the power of regulating the sensation of heat; so that any temperature above 62 of Fahrenheit, under ordinary circumstances, shall give a sensation of /leat, and any temperature below 62 of Fahren- heit a sensation of cold*. * Dr. Cullen, in speaking- of the influence of temperaUtre on the human body in this climate, says : *' If the temperature at any time applied is undef 62 degrees, every increase of temperature applied will give a sensation ot* heat ; but if the increase of temperature docs not arise to 62 degrees, the sensation produced will not continue long, but be soon changed to a sen- sation of cold. In like manner, any temperature applied to the human body lower than that of the body itself, gives a sensation of cold ; but if the temperature applied doe» not go below 62 degrees, the sensation of cold will not continue long, but be soon clianged to a sensation of heat." CuUen's Practice of t>hysic, vol. i. 1 784, p. 9 1 , 92. This point is so nicdLy balanced, and so accurately jU^t,Tiz- at 9€ degree* below blood-heat, or 98, that a variation of one, or at most two degreesj above or below that point, actually produces a sensation of heat or cold ; and which, by experiment pTQpcxly made, would be found to be equally the case in the lorrid and frigid zone as in temperate climates : hence this point may be considered as the actual, or natural nought^ with respect to heat and cold on the thermometer. Voi. 35, No. 146. June 1810. Dd Upon 418 Ohsa'vations respecting a New Scale Upon this principle the pre and the results are so very discordant with P M each 422 Observations respecting a New Scale each other, t^at any idea of ^xing the 0 there, I should think, must be entirely relinquished. With respest lo the freezing point of mercury being, as has been suggested by several philosophical persons, a fit place for the zero, it perhaps may be sufficient to observe, that this would be adapting a scale of heat to a particular thermometer, instead of applying a thermometer to a scale of temperature. The table of temperatures applies more particularly to the different degrees of latitude specified, from the equator to the north pole in the eastern hemisphere, where the gra- dations or diminutions of heat are tolerably uniform. In the western hemisphere, the diminutions of heat from the equator to the north pole are found, from causes well known, to be very irregular or anomalous; and in general the cold is considerably greater on the same parallels of latitude in this, than in the eastern hemisphere. From the equator proceeding towards the south pole, the diminutions of heat are found to be tolerably uniform ; the chief difference consisting in the cold being somewhat greater in the higher latitudes, on the same parallel, than on the north side of the equator. Notwithstanding the irregularity as to diminution of temperature which is observed in the latitudes betweeu the equator and the polar regions in the western hemi- sphere, and the difference before mentioned on the south of the equator ; there is good reason to suppose that, at thet poles, as at the equator, the variation of temperature is not considerable, because the maximum of cold (or minimum of heat) is at the poles, as the maximum of heat is at the equator *. Hence, although every latitude between the equator and the poles yiay be liable to considerable anomalies or irre- gularities, with respect to heat and cold, according as they are more or less exposed, so as to receive the currents of air from higher or lower latitudes ; yet at those two points where there is only one of these causes operating upon each, the variations in the temperature, at the same seasons, in different years, may be but small, comparatively with the others, particularly the middle latitudes. In latitudes, therefore, even at some distance from the * The maximum of cold at the poles is perhaps; mnrc complete thaji the maximum of heat, from a well-known cause, is at the equator: viz. the sun's annual path, respectively to the earih, being not confined to Ihf line of fhe equator. poleS| Jor the Thermometer. '42$ poles, (as in latitudes at some distance from the equator,)- the temperature may be nearly or quite the same as at the poles : thus, at Albany Fort, Hudson's Bay, N. latitude 32, W. longitude 82, the thermometer has sunk to —50, which is the greatest degree oF natural cold ever observed; and is within eighteen degrees of that which I i^ve esiimated io he the greatest natural cold, . •! , Table T. A Table of the Temperattires of different Latitudes, OJ 3 w ? i6 1 'J ^1 1 0 0 QJ CO 1^3 '/3 Is 90 31- 31- ~6i b^2 78 95 21 26 4 80 32-«- 33- -32 55 82 85 22 27 6 70 37-2- 37- — 38 60 88 75 23 28 8 60 44-3- 44- — 21 68 97 65 24 29 10 50 52'9' 53- — 2 78 108 35 25 30 12 40 62- 62- + 17 88 1 19 45 26 31 12 30 70-7- 71- + 36 98 130 33 27 32 10 20 77-8- 78- + 33 106 139 25 2S 33 8 40 82-3- 82- + 67 \\\ 145 15 29 34 6 0 84- 84- + 79| »14 149 5 30 35 4 A B c D E F d e / ^ Notabene, — A is the latitude, in tenths of degrees, from the equator to the pole. B is Kirwan*s table of the mean annual temperature of -each latitude in A : the heat increasing, but hi a diminish' ingratio^ from the middle latitude, viz. 45, the mean an- nual iempefi'ature of which is 57*5 to the equator; and the <:old increasing, but in a diminishing ratio, fjom latitude 45 to the pole. C is Kirwan's table B xeduce^ to the nearest whole ai umbers. D is the greatest cold of each .latitude A, deduced bv subtracting the number iu d, from the parallel number ia C, up to latitude 40, and from thence up to latitude 90, subtracting the number in C from the number in d; the first producing the plus degrees^ and the latter the minus .degrees. £ is the greatest heat in the shade of each latitude A, D d 4 deduced 464 Observations respecting a new Scale deduced by adding the number in e to the parallel num- ber in C. F is the greatest heat in tJw sun of each latitude A, de- duced by adding the number in f to each of the parallel puinbers in E., d \s an increasing series of ninety, in number corre- sponding \yith the degrees of latitude from 0 to 90, in co- lumn A, viz. from 5 to 95. £• is a decreasing series oi nine, in number from latitude 0 to 90, viz. from 30 to 21. y is a decrtasi?ig scries of 7iine, in number from latitude P to 90, viz. from 35 to 26. g is a decreasing series of nine in number from the midr -^lle latitude of 45 up to 90, and the same down from lati- tude 45 to 0— latitude 45, being 13. The temperatures marked in columns D, E, F, give the temperatures of ordinary years ; in order to give the defec^ or Gxceas of extraordinary seasons the parallel number in g must be subtracted, or added to either of the columns rnD,E,F. Mr. Kirwan has given the mean annual temperature of every latitude, from the equator to the north pole : in this table each tenth only is given, but the temperature of each intervening latitude may be obtained easily by calculation from those given, viz, by allowing one- tenth for each der gre& of latitude, in the columns c?, e,f, p^, N. B. The thermometer, in taking observations, is sup- posed to be placed at about 5 or 6 feet from the ground, and perfectly insulated or detached from any body which can cause reflected heat, when pdaced in the sun j and for observations in t^e shade, placed ip a north aspect, where the sun never reaches. Hencp, according to this calculation, the greatest cold at the poles, or the greatest natural cold, is at —68 of Fah- renheit, or 100 degrees below the freezing point of water ; therefore, in order to reduce Fahrenheit's scale to this, 68 inust be added to every degree of Fahrenheii-s above the O5 and for any degree helotp the p of Fahrenheit, that nun^- ber must be subtracted from 68. It might be expected, as the gradations in the above table are unifofm, and calculated from the equator to the poles, that the temperatures in thjs table should correspond with considerable exactness with actual observ^tior>s in pvery instance; but it should be recollected, that a dif- ference must occasionally arisp from various causes, viz, ' ' . ' difTerence i for iheThei'momeler. 493, difference of elevation; vicinity to^ or distance from, the seat; the intervention of mountainous and woody coun- tries, intercepting the currents. of hot or coid air, from lower or higher latitudes];; difference of soil, as to its power of absorbintX, accumulating, or reflecting heat, &c. All of which irregularities, however, it might perhaps be possible to calculate and allow for. From the equator to 23^ degrees on each side of it, the progressive variations in temperature differ somewhat from the other latitudes ; this is allowed for in the columns of the mean annual temperatures, and likewise in the three succeeding columns, which may be considered as emanations from ihe first. I shall now conclude by presenting the following Table, {see next page) which exhibits a comparative view of the spale of Fahrenheit's thermometer with jnine. JEocplanatlon of the four Columns, Nbta bene, — A is my proposed scale, having the zero at mean temperature. B is Fahrenheit's scale, C is the centigrade measure, adapted to ci)lumn A. D is my former scale, having the zero at the point t have estimated to be the greatest natural cold. The four additional points marked thus * are appropriate to this climate, viz. the greatest degree of cold, which was observed on the morning of December 25, 1 796 : and the tivo greatest decrees of heat, viz. in the shade and in the sun^ observed m the afternoon of July 13, 180S. — The temperature of springs, means of course the constant tem- perature of ordinary (nnmediated) springs, which in all cUmates corresponds pr^^ty exactly with the mean annual temperature of the place, which iu London is .51'9. N. B. Thermometers have a point marked temperate^ viz. at 50 of Fahrenheit; but 57| is the tniddle point of the scale, that being the mean annual temperature of lati» tude 45t. Richard Walker. Oxford, May 31, 1810. f Hence it follows that in islands, particularly small j>Zti/;J*, surrounded by a large extent of sea, the winters are warmer, and the summers colder. than on continents. \ The winters in those parts of North America which have been culti- vated, are much less rigorous now than fo.merly, principally in conser quence of the destroying of forests, occ. which present several sources of (:v|d, amoDgst vyhich tvap^ralwi'h no iucousiderablc one. Table 42(J Observations on a new Scale for the Thermometer* Table II. ^ Table of the most essential Points in a Scale of Heat, W. F. W. W. 4-150^ Builb. > 4-212. . + 100. . .sso a. 1 14. Spirit 4-176. .. + 76. 94.4 -J- 1 1* ~ Boils. « « ^ ^ X Greatest Solar ■4-126. .. + 43. ..194 -t" O'i Heat in England. . 1 Kf\ __ Fever - 4-112. ..133. . .180 't ou — " Heat. I o/:. Blood ■ 4-98. . . + 24 . ..166 -f-oo *— Heat. ,1 qn Greatest Shade - 4-92., » . . + 20 . , ifirt fJ-OU— " Heat in England. 1 . 1 \j\j i_ 14 Summer 4-76., ... + 9.. ..144 4-14 — Heat. f\ — Mean - 4-62., ... + 0.. ..130 0 — Temperature. * Temperature of Springs in Fngland. 4-35 -7.. . .120 nf\ _^ Water - 4-32 -20.. . .100 ^6\J —~ freezes. -64*- Greatest Cold in England. — 2 -43 66 «,101 Quicksilver -39 -67 29 ^■^ A \/ X - Freezes. _! lO Greatest Natural -50 -75 18 •" 11^ ■— Cold observed; 1 2rt *» Greatest Cold -68 -86 O — loU ••" Natural. 1 ^d ._— Greatest Cold -91 — 102 -23 — 153 — Artificial. A B c D LXIII. On , t 427 ] LXIII. On the Properties of Furze or Whins. By Major Spencer Cochrane, of Muirfield' House, near Had- dington *• Sib, X HE Society having honoured me by publishing iu their 23ih vokime my comniunication, stating the advan- tages arisine: from the culture oF poppies, and that seven ciinces of fiiie salad oil were furnished by expression from two pounds of the seed ; I now beg leave to add^ that J am informed, considerable quantities of poppy seeds have been Jately bought up, in different parts of the country, and the expressed oil from them sold at the price of Florence oil ; and that emulsions made from poppy seeds answer in every respect the purposes of those made from almouds. The following communication may perhaps be deemed worthy the notice of the society ; it relates to the use of Whins or Furze. Its'utility as food for cattle has been long known, though probably^ not sufficiently appreciated; butas a medicine, I never till within a few^ years heard of it. My information was first received from a gentleman who has been an officer in the army, a friend and relation of mine ; he is seventy-five years of age, and in good health, and what he says may be depended upon. In October 1806, he informed me that his sight had been much strengthened by drinking an infusion of whin or furze blossoms, dried in the sun in sumnjer. The infusion is made from a tea- cup full of the blossoms, in a tea-pot in the manner of tea, and the dose half a tumbler at night ; that he never had a cough since he first used it, which was fifty years ago ; it acts as a diuretic, and by perspiration, and, when the dose is in- creased, promotes sleep. In October ISOS, he informed me that he still continued the use of the whin -tea, that hb had no cough, and ihat his skin was remarkably fine and goft, which he attributes lo its use. I have also used the whin blossoms with good effect my- self, and can safely .recommend them. My friend supposes the young shoots of furze may an- swer if the blossoms cannot be got ; he informs me, that when an epidemical cold came from Germany, and destroyed many horses in England, the east wind continued six weeks, ^nd the infection came over to Ireland, where he had the care of a troop, in so poor a village that he could get * From Transactions of the Socv'ty for the Encouragemenl of Ails^ Maimfao furesj and Coi/inuice, for J SOU. neither 438 blservaiionf 9n growing Timber, neither bran nor malt for mashes, which were ordered for the horses with sulphur, after bleeding: That he ordered the men to cut furze, and ordered them to give it to the horses, after they had beat it well on the pavement : that at first they had to ujix it with oats, but that in two days the horses devoured it like clover. That by these means he recovered them all, though every other troop lost two or three; and that his was the only troop in good condition at the review. I remain with esteem, sir, ' ' Your sincere and humble servailt, Muirfield, Jan. 22, 18C9. SpKNCER COCHRANE^' To C. Taylor, M.D. Sec. LXIV. Additional Ohservatioiis for the Purpose of ascer- tmning the Fahie of growing Timber at different and distant Periods of Time, Bi/ Mr, Charles Waistell^ of High Holboniy London *. Sir, In the Society's last volume, under the head of Agri- culture, are some tables and observations of mine, on the growth of timbcrf ; and I have given one instance of six acres of very bad land, pl.inied with Scotch firs under my directions, which at 29 years growth, and at the small price of U. a foot, had paid the owner 5/, per acre per annum compound interest. My motive in communicating these tables, observations and facts to the public, was to promote the planting of inferior and almost useless soils, in order to obtain from them timber of our own growth, sufficient for at least many of the purposes for which foreign tim- ber is imported at an immense annual expense. For instance, much of such inferior soils will be found on Con- nock Heath in Staffordshire, on the moor lands in the north of that county, and on the moors in Derbyshire, Yorkshire, and northwards to Scotland, also on Bagshot Heath, Salisbury Plain, the heaths and wastes in Sussex, Hampshire, and Dorsetshire, and in many other counties in England, and also in Scotland and Wales. In that pa- per I suggested, that information of very great value on the subject of planting, might be obtained from noblemen and gentlemen to whom the Society had given medals and premiums for plantins^ trees, if they would communicate to the Society (heir subsequent observations on such plan- ♦ From Transactions of the Society for the EncQuragemtnt of Arts, Mam fac* tures, and Commerce^ for 1809. f See Philosophical Magaziue, vol. xxxiii. mions| Ohservatimts on growing Timt&r, 4^$ lations ; but it is to be regretted that the Society have not yet received any cominiinications on the subject. I have been solicited to republish my tables, &c. by different gentlemen, who I have reason to believe are very competent to judge of them, and I have in consequence several additional tables in forwardness with this view; but, previous to such publication, I wish to be furnished with a great variety of facts as to the growth of timber^ and the management of plantations; and I shall feel much obliged to any persons who will have the goodness to send me their observations and statements of facts, respecting the growth and management of plantations ; or, if they prefer it, they may send them to you at the Society of Arts, &c« The names of those who send such statements will be either given or suppressed as may be requested. I will recapitulate nearly in the words of my former com- munication, several particulars on which mformation is wanted. It would, for instance, be desirable to have the nature of the soil and under strata described, on which plantations have been made; its value per acre; the mode in which it was prepared for planting; the sorts of trees planted thereon, and which of them were found best suit^ -ed thereto ; the distances at which the trees were first planted; at what periods they were thinned, and how many cut out at each thinning ; and their measure and value ; the present height, distance, measure and value of the trees now growing on an acre; what distances are found most advantageous ; also to what proportion of their heights they should be pruned up, and the best and most expedi« tious mode of performing the operation. Great loss is frequently sustained by omitting to thin plantations properly, and indue time, but I am not in pos- session of facts to calculate with accuracy what this loss may be; I will however venture to give a short statement of some calculations I have made, as to the loss that would now be sustained by letting trees grow to a great age. In Miller's Gardener's Dictionary, it is stated that in sL fall of oak timber in Lord Bagot's woods, Mr. Marshall counted the rings of one tree, which wassound at the butt, and found the number to be about 200. Its bole was 22 feet long, and 108 inches in circumference in the middle. Its contents 110 feet, which at 2i. amounts to 11/. I think it was last year, that a tine sound oak-tree was cut down, between Shrewsbury and Oswestry in Shropshire, of 300 years of age, and sold by auction for 32/. 5s, — And under my direction, many oak trees were cut down, some years 430 Ohseruations on growmg TimleY, years ago, that could not be less than 300, and some of them probably 400 years of age, and even more. In Hun- ter's Evelyn's Silva is given the circumference of 10 trees, and not one of which was probably less than 500, and sonle of them probably 1000, years old. Lord Bagot*s tree of 200 years old, above mentioned, would, at the present price of 35. a foot, be worth 16/. 109. Supposing that 3.v. a foot should continue to be the ppice of oak-timber for the next 200 years, we will inquire what sum might be raised by growing four oak-trees in succession, upon the same spot of ground, each tree to be cut down when 50 years of age, and that their boles should be of the same length as that of Lord Bagot*s, viz. 22 feet. I fix on fifty years of age, as being convenient for my calculation ; and nearly the most profitable period at which to cut down trees of 22 feet bole, which haVe grown at the medium rate of one inch in, circumference, and 12 inches in height annually. After its 52d year, such a hole ceases increasing, after the rate of 5 per cent, per annum* : but the whole tree, in- cluding the top part above the bole, may continue increas- ing after that rate until its 6 1st yearf. I do not fix on 50 years of age as being the most profit- able ase at which to cut down trees ; probably 60 or TO years of age would in some instances be preferable. Sup- posing an oak-tree haS increased as above mentioned, its bole of 22 feet would, at 50 years of age, measure 39 inches In circumference at the middle, and one-fourth of this, namely 9f inches, squared and multiplied into 22 feet, its length gives 14 feet 6 inches for its contents, which at 35. a foot, its present value, amounts to 2/. 35. GcL, Sup- posing 2/. 3s. Qd. to be the value of each of the four tree* of 50 years of age, grown in succession upon the same spot of ground, in the period of 200 years, w^e will calculate to what the three first trees would amount, if their value was placed out at compound interest, for the respective terms of 150, of 100, and of 50 years. £, s, d. ^. s. d. 2 3 6 Accumulating during 150 years, at 5 per cent, per annum compound interest, will amount to - 3,280 O 0 2 3 6 Accumulating as above for 100 years, would amount to - 286 0 O ♦ See Table 12 cf a bole of 24 feet, in the 2Cth volume of the Society'*. Transactions, page 68. t See niy firrt Tablfe in ditto, page 49. Accu* Observations on growing Timler, 43 1 ^, s, d, •>*/r. :ry- j^, s, d» 2 3 6 Accumulating as 'kbove for >50 years, will amount to - 24 0 0 ; Add the value of the tree to be cut down at the end of 200 years 2 3 6 Total amount in 200 years — 3,592 3 6 And carrying forward this calcu- lation, the total amount of the produce in 300 years t\ould amount to — i^". 4 72,408 0 0 In former times, when the value of oak-woods was eitimaied by the number of hogs their acorns would fat- ten, the greai age of trees would be of small consideration; but in the present limes, I am persuaded, that if gentlemen who have many. trees standing of the age of 150 years and * upwards, would give this subject its due consideration, they will be aware of the immense loss to which they are voluntarily subjecting themselves. — And this great loss is much to be regretted, in a political point of view, espe- cially as the produce of this island is insufficient for its necessary consumption. My motives for troubling you with this hasty production are, to promote the good of the public, bv endeavouring to persuade gentlemen to bring forward well ascertained facts, respectmg the most profitable management of grow- ing timber trees, and to induce them to mvestigate, with accuracy, this very curious and, important subject. If you think it is likely to have those effects, I shall thank you to lay this paper before the Society of Arts, &c. for their consideration. I am, sir, your obedient servant, No. 99, High Hc.lborn, ChARLES WaISTELL. Oct. 1809. LXIV. A List of about Five Huiidred Collieries in and near- to Derbyshire, By Mr, John Farey, Mineraiogicfll . Surveyor. To Mr. Tilloch, Sir, X INCLOSE a list, of such collieries as I have either visited or obtained information concerning, in the course of my recent examination *of the county of Derby, and the borders of the seven adjacent counties. Should you deem the 4Stf List of Collieries in and near Derbyshire* the same worthy of a j^Iace in your Philosophical and Geo- logical Magazine, it may be proper to observe, that the names of the places in the first column, arc not always those of the parish in which the coal \vorks are situate, but of the nearest or most convenient place, shown in ge- neral maps, by which to refer to the precise site of the collieries. Also, that many of these works are now dis- continued : yet as in almost every instance, more of this valuable mineral remains still ungotten, in or near to the same spot, the recording of all places where coals have at any time been wOrked, seems an object of some im- portance. In the report on the county of Derby, which 1 am at present employed in preparinsf, for the Board of Agriculture, I intend to give in one alphabetical list, the bearings and distances of each of these collieries, from the towns mentioned in the first column, with the particular place in the series of strata to which each colliery is to be referred, as far as I am able in the present instance : the collating of the ^reat mass of information which I -have been favoured with, from the several coal-masters, and their agents and workmen, being yet unfinished, as well as the reexamination of some parts of the interesting coal- fields, within the limits of my intended map, in districts where the alluvial coverings, the faults and stupendous dis- locations of the strata, have presented great, but as I trust, not insuperable difficulties, to the complete elucidation of these highly important strata. In the report I shall di- stinguish such of the above collieries as now arc, or recently have been, in work. Where no county is mentioned to the places in the lirst column, Derbyshire is to be under- stood; in which county I find the coal strata or measures, distributed over not less than 190,000 acres of its surface! T shall esteem it a great favour, if proprietors of estates, or others, who happen to be possessed of correct accounts of the sinkings or measures at any of the collieries below, in documents to which I may not have had access, or respect- ing any ancient collieries within these limits, which may have eluded my inquiries, that they will communicate co- pies of such particulars (addressed as below) as soon as convenient; carefully distingishing the bearing and di- stance from one at least of the above places; the time of ceasing to work, old collieries, if known, &c. The borings or sinkings, where trials to any depth have been made, whether successful or not, would be alike acceptable, such being the materials from which, principally, a correct ac- count Names of Collieries in and near Derbyshire, 433 count of the subterranean geography of thfe district, or the kaowledge of its strata, is to be drawn. I am, sir. Your obedient servant, ja^Uppci Crown Street, West- JOHN FaREY. nuiistcr, June 5, 1810. Places' Names. Narr.es of Collieries. f Alfreton, Four - lane - ends, Green- I hill-lane, High-field-lane, Nether- jilfreton \ Birchwood, Oakerthorpe, Riddins, I Svvan\vick-grcen,Swanwick- delves, l^ Somcrcotes, Somercotes-furnace. Asfiover Alton, Birkin-lane. jl km3-w0od_, Smithv-wood-engme, ^"^^^^''^ [ ThorncliflT. rDelph-house, East-wall, Eaes, Mov-, Cheadalcy Staff. . . < berley, Shaw (or Sbamrr), Shstw, \_ Woodhead. nL jjj J. o^ £c { Crown- point, Cun^al-wood, New- Cheddlefon, Staff, A , lou^i xir.i •* ^ \ stead, Shaffeiiong, Wetlcy-moor. Ash-gate, Boythorpe, Chesterfield- town'^s-end, Chesterfield -furnace, Calow, Dunston, Grass -hill, Hady, Ilasland, Little-common, Lotjns- CfiesterfieM ..... .^' ley-jrreen, Moor-top, New-Bramp- ton, Newbold-common, Newbold- field, Stone-gravel, Tapton, Wal- ton, VVingerworth-park, Winger- ^ worth -furnace. ^T , ^ 7 f Gresley, Grcsley-hall, Round-hole, Clotvn '. . . . Clown. ^ , C Benty-field, Coch-ior nether- park, * * * ' L Codnor upper-park. Cole^Orton, Leices f. Cole-Orton, Lount new, Lount old. Conhhorovgh, Yorks. Conisborough, Dennaby. Cossall, Notts Cossall, Robinets. Crick Plaistow-Grecn. T^ 7 ^7, /Dale-Abbey, Has:, Lower -Hag, jyale^^hhey j p.^^^^^ >^ Denltf 'Dilhorne, Stqff^^ Names of Collieries in and near Berly shire, 455 Places' Name*. Names of Collieries, p. J CDenby, Denby hall, Roby east-field, ^^^^y I Roby west- field. Smithy-houses. Dilhorne, Parsons - field, Swetley (Lowes'). Allington, Bank-end, Diglee, Fuff Bislev Chp^hifp <: nace-clough, Gee, Hag-bank, Hoo- Visley, Lfiesfufe . .< j^^^^ Lyme, Lyme-park, Norbury, L Poynton, Red-acre, Worth. Dore Dore, Ringing-low-bar. rApperknowl-common, Cole-Aston, DroTifield < Dronfield, Hill-top, Ounston, (, Stubley, Woodhouse. rDuckingfield, Dunkirk, Flowery- JDuckingfield, C/iesA field, Hough-hill, Newton-moor, V. Rabbit-hole, Score-wood. n , ^ ,, . CAdelphi- furnace, Duckmanton-com- Duckmanton (long) | ^^^_ Middle-Duckmanton. Eastwood, Notts. . |Be|gerlee,^Brinsley new, Brinsleyold, Eccleshall Barlow^ '\ Grey - stones. Mill - house, Moss, (m Sheffield,) > Smelting, Trap-lane, Whitley- Yorkskire J wood. rArbor-lands,Bole-hill,Bramley-moor, Eckington ,,»,., .< Coldwell, Eckington, High-lane, (. Mossborough-moor, Troway. f Birchen -booth, Black -clough (or r,7 , ,. .;" I Beat), Blue-hills, Chest, Dane-head, ^'^/''c^^^ < Dane-thurn, Diamond-hill, Gold- Jieid), btcijr I j,|^^^^ j^32le - barrow, Notbury, L Penny-hole, Whiteshaw. r. ^ a. /r J L ^ Cloug^h-head, Foxton-wood, Stilc- Foxton, Staffordsh. -J ^^^^^ Fullivood' Chapel, \ ^ {in Sheffield) Yorks, ] ^^^"^^o^- Glossop Combs, Simondie>^. Greasborough, "^ Cinder-hill (or IVliddle-field), Haw- Yorks J wood. Greasley, Notts. . . Beanvale-abby, Greasley, Limes. r Bally field, Gkedless-commonv Hans- Hanmiorth, Yorh> < worth, Hanswovth - woodhouse, "^ ' l_ Intake, Orgrave, Woodthorpe. Hart hill, Yorks. . .^ Woodhall-moor. Hartshorn .... ^^. Gosley- waste, Hartshorn. Hathersage . . • . T."^ Stanage-pole. E e 2 Hay 436 Kam^s of Collieries in and near Derby sltlre. Places Names. Names of Collieries. Hen/ field (m Glos-' sop) Heage >Aspinsh.iw, Burn'd-edgc, Moor-top, Heagt', Heage-bent, Morley-park, Town-field. ;^^„„^j, j Aldercar, Heanor, Langley, Miln- '' I hay, Shiplev. Heath Heath, High -house. Heather, Leicester. Heathtr. Higham HighaiVi. HoJd'rook Holbronk. Holmesjield Rank, Sahers-sitch, Thickwocd. TT I S Hor^lt■v, Horslcy-woodhouse, Slack- ^^^^^^U I fields. Hyde-Chapel, { Bioonistcer, Denton, Hyde-lane, Cheshire 1 Werneth-low, VVoodley. jj, . f Colmanhay-wood, Ilkeston, llkeslou- ^ ** 1 covnnion, Little- Hallan}. 't^ . ct ^' [ Cro\v-c;utter, Hav-house, Ipstonc, ipstone, Sta£ | Kn.pe, Nether-iield. rGander-laiic, Killamarsh^ Nether- Killamarsh < moor, Kii-lamarsh old-delpb, Over- C thorpe. Kimlerivorih, i Blackburn-bank, Bradgate, Kimber- Yorh 1 worth, Meadovv-hali. /'Froghall, Garstone, Hazles-cross, Kingsley, Staff. . .^ Hodge-hay, Jack-elm, Kingsley- (. bank, Lees, Rake-edge, Ross-bauk. f Blake-low, Hollinrion, Chif-bank, I Eastborough-lane, Hurdsfield, Mac- Macclesfield, Cites. <{ clesiicld- coiiinioir, Riley - clongh, [ Shrigley-fold, Suanco, Throtles- L nest. Marple- Chapel, Ches. Brabins, Chapel-house* Matlock Lea, Liunsdale, Tanslcy-green. Aleasham I^'l"7fh°'-X^'' M^'aslK.m/Meashain. I lields, Uaktliorpe. r Bore-lane, Broadhuist-edgej,. Comp- Mellor {in Glossop) < stal-bridge, Ludworlh, Old-hali- C wcx^d, Shaw -hay. Mexhdrough, Yorks. M ex borough. Morley . . Morley. Mosstcy,lMncash. ^ *^'"g-'^\"'5' fark> R»":hcs, Seoul- •^ f luul, wmdy-bnnk. Mctlram, ChesJure, Hague- bank, llill-end, Hodge-hall. Newall Names of Collieries in and near Derhj^hire, 437 Places' Names. Names ot Collieries. rBreiby, Hall-fields, Newdl, Newall- Ncivall {in Stapen) park, Perkins, Stanton, Sv.adlin- hill) I cote, Water- titid. Wooden-box, L Wood-field. JN'eW'Milk {hi > Eaves - know! , Lower - hou'se^ Tor- Glossop) I mine, Warps-nioor. Norton^ Staff. .... Bow-green, Whitfield. Norton Lees-halt r A nkerbold, Berrisford-mooi*,. ' Clay- North'lVinJield . . A cross, Hcnmore, Loco-lanej Pilsley- v.. lane, Tupttni -green, Woodlhorp^ OakmooT' Mills ■^ {near yUveton) vBeeluw, Car- wood. Staff.,.,.....,} Over-Stal, Leicest. Warren-hill -finnace. Packin^ton, Leicest. Packington. ♦ ro / 71 f Tf/ i" Brown-hills, Essins:ton. new CoHierv, ^PeLsall hi ear Blox- I ^ ■ ' r /^ . t i • /\ \v /^' \ LsbH^iTton-wood, Cjoscot, Lords- "^''^^ ^^^^ L hay, Pelsall, Wyrl.v-bank. '; Penistone Yorks -^ P'"^^"^^'^"^^* Flash-house, Fu•llsha^y; ' ' ' ' i Law, Midhope-slones, Paw-hill. Pentrick Casile-hiil, Harts-hay, Pentrich. Pinxton Carter-lane, Pinxton. -rt .. ^, • 7 r Bakestone-dale, Berristow, Harrop, Ch h I Pott -hall, Spons - moor, Spons, (_ Stvpersun. RainoiV'Chapcl, S Kerridge-cast-side, Kerridge -north- Ches/i i end, New-post, Rainow-low T, t ^ I ^Netl;er-Hoiio;h, O^'er-Houtrh, Raw- Rawmarsn, Yorks, \ , r« 1 1 • i xxuuyuLUf^n, ^^,no, ^ marsh, Snibbing-lane, T>-^7 /• D * ■ L, 5Batterly-park, Birtterly-c.ar, Green- Ptpley{tnPentrwh)^ wich, R.pley. rClough, Herringthorpe, Hill-top, Rotherkam, Yorks. < Kimherworth-park, Mossborongh- (^ common. Rudgley^ Staff. . . Bruerton. rCrooks-nioor^ De-ep-pits, Harbour- s'e^e/ J, YarA^. . .< thorn, Manour,Pafk-f4ifnace,Ponds, C Sandy-gate. SInrland Shirland, Smithy-moor, Stretton. Silkstone, Yorks, . . Silkstone. Skegbiji Notts Shilo, Dirty-Hucknale, Skegbv. „ ,, iSmallev, Smallev-conimon, Simon- pm^l^-y \ f^eld, Woodho'use-lane. E e 3 Smithsby 438 Names of CoU'icries in and near Derly shire » Places' Names. Names of Collieries. Smithshj Pistern. South' Nbrmanton . Berristow, South-Normanton. c,, • . TA / ^Armitacre, Diinorworth, Low-asl), Slanmngton,Yorks.-^ Storri, Wadslly. Stanton {Oi/ Dale) . Hallam-bridge (or Nutbrook). Slanton-liarM, ) Heath-End, Stanton-Harold. Leicester ) ' Slapleford, Notts. . Bramcote. Staveley Norbrigs, Staveley, Woodthorpe. Sutton {in Scars- ^Sutton, Sutton-common, Wood- dale) i nook. Swepston, Leicester, Swepston. '^Zkhhire ^"'^' \ P°>«s^^'°<-'h, Waverton, Wilneeote. Tankersley, Yorks, Tankersley-park. Taxhall, Cheshire. Castedge, Gap-si tcb. Temple-N^^manlon\^'^^"l°°'' Grass- moor (Piatt's), TeversaUy Notts. . . Dunshill. Thursfield, Staff. . Bernersley-green. Ticknall Ticknall, White-holly-coppy. Todwick, Yorks, . . 'I'odwick-moor. Tibshelf Biggin, Harsloft, Tibshelf. Treton, Yorks Cat-cliff. JVales, Yorks Wales. Wathy Yorks Abdy, Wath-wood. WentworthXhapelA^'''''''''\^Y''^:^ ^°^f?^^' ^^^:i- Y .h Y wood, rark-gate, Swailovv-wood- " C nook, Wentworth-park. 7T/:.,.* tj 77 5 Stanley - common. West - Hallam, West-Hallam \ West-Hallam windmill-hill. IVhiston, Yorks. . . Royds-moor. IVhtttinston 5 Glass-house-common, Whittington- ° ( moor. Wicker sley. Yorks, . Brecks, Hollings-moor. Win cle- Chapel, j Green-hill, Hay, Latche, Mouse- trap, Cheshire i Rohins-clough, Quarnford. Wirksworth Aldcrwasley, Wig well. WollatoVy Notts. . . Aspley, Trowel-moor, Wollaton. Woodhead, Cheshire Crowden-clough. Worsljorot/gh, Yorks. Siainborough-park, Worsborough, Yorks' ' S ■'^^^P"^^^^ Hunshelf, Westwood. LXVI. The [ 439 ] LXVI. The Croenian Lecture. Bu William Hvdk %. WoLLASTON, M.D, Sec ± AM aware that the remarks, which I have to offer on the present occa?;ion, may be thought to bear too little direct relation to each other for insertion in the same lecture; yet any observation respecting the mode of action of voluntary muscles, and every inquiry into the causes which derange> and into the means of assisting the action of -the heart and blood-vessels, must be aHowed to promote the design of Dr. Croone, who instituted these annual disquisitions. And it has always appeared to be one great advantage at- tending the labours of this societv, that it favours the pro- duction of any original knowledge, however small, in a detached form ; and enables a writer to say all that he knows upon a particular subject, without inducing him to aim at the importance of a long dissertation. I shall therefore make no apology for divi-ding the fol- lowing lecture into three distinct parts. In the first of which I shall treat of the duration of vo- luntary action. In the second, I shall attempt to investigate the origin of sea-sickness, as arising from a simple mechanical cause deranging the circulation of the blood. In the third, I shall endeavour to explain the advantage derived from riding, and other modes of gestation, in as- sisting the health under various circumstances, in pre- ference to every species of actual exertion. Part I. On tlie Duration of Muscular Action, The necessity of occasional intermissions from a series of laborious exertions, is within the experience of every one ; the fatigue of continuing the eifort cf any one voluntary muscle without intermission even for a few minutes is also I sufficiently known; but there is a third view of the dura- lion of muscular action which appears to have escaped the notice of physiologists ; for I believe it has not hitherto been observed that each cfibrt, apparently single, consists in reality of a great number of contractions repeated at ^extremely short intervals : so short indeed that the inter- mediate relaxation cannot be visible, unless prolonged be- yond the usual limits by a state of partial or general de- 'bility. • From Philosophical Transactions for 1810, Parti. K e 4 J havt 440 On the Duration of Muscular Action. I have been led to infer the existence of these alternate potions from a sensation perceptible upon inserting the extfi'mity of the finger into the ear. A sound is then per- ceived which resembles most nearh- thai of carriages at a great distance passing rapidly over a pavement. The rapidity of the motion varies according to the degree of force with which the finger is retained in its place. The sound thus perceived is not at all dependent on the de- gree of pressure upon the tympanum; for, on the contrary, the vibratorv sound is most distinct v»hen that pressure is slight, if the linger be at the same time rendered rigid by the forcible action of antagonist muscles; and when the ear is stopped with great Force without the presence of muscular action, no such sound is produced. For instance, if the head be rested upon the hand in such a position, as to press with jts whole weight upon the ball of the ihun»b applied to the ear, no noise is perceived, unless the extremity of the thumb be at the same time pressed against the head, or unless the action of some other muscles be communi- cated to the ear, by any inadvertence in the method of cbii-r ducting the experiment. When I endeavoured to estimate the frequency of these vibratory alternations, they appeared to be in general be- tween 20 and 30 in a second; but it is possible that the method \ employed may be found defective, and it is to be hoped that niy estimate may be corrected, by some means better adapted to the determinaliou of intervals that cannot actually be measured. It was by imitation alone that I was enabled to judge of their frequency. For this purpose I contrived to render the v'rbration itself, and the inniative sound, both audible by the same ear. While my ear rested on the ball of tpy thumb, my elbow was supported by a board lying horizontally, in which were cut a number of notches of equal size, and about one-eighth of an inch asunder. Then, by rubbing a pencil or other round piece of wood with a regular motion along the notches, I could imitate pretty correctly the tremor pro- duced by the pressure of my thumb against my head ; and by marks to indicaie liie number of notches passed over iri five or ten seconds, observed by my watch, I found re^ peated observations agree with each other as nearly as could be expected ; for I could not depend upon exerting the same degree of force in different trials. That I might not be deceived by the resemblance of tre- mors, which coincided only at alternate beats, and there- for^ On the Duration of Muscular Action, 441 fore might be considered as octaves in music to each other, I sometimes employed notches at greater and sometimes at less distances from each other, bui the result was noverthhil.Trsnb. vokU 610) It beeins thai the vapours to which these tremendous concussions are owing, inimeirse i*i qurintity, and uf prodigious I'orce, btiug for a time coii- lineJ on all sides, elev .le the suiface of a tountry to a vast eitent unt't thev either find venr,or meet with some partial cmjreof condensation ; and hence the alreiivite htaviu'^ and subiidence of the ground will produce ijiudi iIa; sit.ji«i cilicti as »i'C r;j;i)j, uad fJIizig of the swell at sea. thi 446 On the salutary Effects of Riding, the term gestation is employed by medical writers, as {t general term comprehending riding on horseback, or in a carriage, and although the merits of such motions, espe- ciallythe former, were clearly noticed, and perhaps even over-rated, by the discernment of Sydenham, I believe that no explanation has yet been given, of the peculiar ad- vantages of external motion, and am persuaded, that the benefits to be derived from carriage exercise are by na means in so hiffh estimation as they ought to be. Under the common term exercise, active exertion has too frequently been confounded with passive gestation, and fatiguing efforts have consequently been substituted for motions that are agreeable, and even directly invigorating, when duly adapted to the iitrength of the invalid, and the peculiar nature of his indisposition. The explanation which I am about to offer of the effects of external motion tipon the circulation of the bloo(ii5 is founded upon a part of the structure observable in the ve- nous system, the mechanical tendency of which cannot be doubted. The valves v/hich are every where dispersed ihrough those n'ssels, allow free passage to the blood, when propelled forward by any motion that assists its progress; but they oppose an immediate obstacle to such as have a contrary tendency. The circulation is consequently helped forward by every degree of gentle agitation. The heart is supported, in any laborious efibrt that may have become necessary, by some obstacle to its exertions ; it is assisted in the great work of restoring a system, which has recently strug-ffled with some violent attack : or it is allowed, as it were," to rest from a labour, to which it is unequal, when the powers of life are nearly exhausted by any lingering disorder. In the relief thus aff'orded to an organ 8o essential to life, all other vital functions must necessarily participate; and the various offices of secretion, and assimilation, by ■yvhatever means they are performed, will not fail to be pro- moted during such comparative repose from laborious ex- ertion. Even the powers of the mind itself, thotigh apparently- least likely to be influenced by mere mechanical means, are manifestly, and in many persons most immediately, affected by these kinds of motion. It is not only in cases of absolute deficiency of power to carry on the customary circulation, that the beneficial effects of gestation are felt, but equally so when com- parative inability arises from redundancy of matter to be propelled. and other Modes of Gestation. 44Y propelled. When from fulness of blood the circulation is obstructed, the whole system labours under a feelinc: of hurry and agitation, with that sensibility to sudden un- pressions which is usually termed nervousness. The mind becomes incapable of any deliberate consideration, and is ini])ressed wiifi horrors that have no foundation but in a disteinpered imaginaliou. It is in moderate degrees of this species of affection that the advantages of carriage exercise are most sensibly felt/ The composed serenity of mind that succeeds to the pre- vious alaru), is described by some persons with a degree of satisfaction that evinces the decided influence of the remedy. With this steadier tone of mind, returns its full power of cool reflection ; and if the imagination becomes more alive than usual, its activity is now employed in con- ceiving scenes that are amusing and agreeable. As an instance of direct relief to a circulation labouring from mere fulness of blood, I may adduce that of a person, whose friends, as well as himself, were apprehensive, from the violent and visible throbbing of his heart, of the ex- istence of some organic mischief, and were in some mea- sure alarmed for the consequences. He was persuaded, and not reluctantly, to go without delay for medical advice, and was accordingly conveyed in a carriage to the house of some physician of eminence^, but did not succeed in fniding him at home. As the sym- ])toms did not appear lo admit of delay, and were at least not aggravated by the motion, it was hoped that the wished- for advice might be obtained at a part of the town which hap- pened to be at some distance. But the second attempt proved as fruitless as the former, and a third was made with the same event. Since the throbbing had by that time considerably abated, he was contented to postpone any further efforts to the following day, and directed the carriage homewards. By the time that he returned to his friends, he found that ilie motion of travelling over several miles of pavement bad apparently removed the complaint. Tlie pulsation of the heart and arteries had subsided to their natural standard, aiul he congratulated himself, that his search of a remedy had not been ineffectual, although he had been disappointed as to the source from which he thought he had most reason to expect relief. If vigour can in any instance be directly given, a man may certainlv be said to receive it in the most direct mode, when the important service of impelling forward the eir- onlation of his blood is performed for him by external means. 44S Moaes of Tuning Instrunienls. means. The main j;pring, or first mo\rer of the System, h thereby, as it were, wound up; and although the several subordinate opcratiousj of so complicau'd a machine can- not be regulated in det:ii! by mere external agency, thev nuist eaeh be performed with greater frecdoni, in conse- quence of this generaf supply of power. In almost every treatise on the subject of chronical dis- eases, are to be found numerous instances of the benefit produced by the several modes of gestation which have been most generally adopted ; as riding on horseback, i!i carriages, sea-voyages, and swinging. And in many cases which might be adduced, it has appeared too clear to admit of a doubt, that the cure of the patient has been owing Sdleii/ to the external agitation of his body, which must be allowed, at least, to have had the effect above ex- plained ; that of relieving the heart and arteries from a great part of their exertion in propelling the blood, and rnatf theref^jre have coutributcd to the cure, by that means only. The different modes above mentioned are adapted from their nature to ditferent degrees of bodily strength ; -and if there are cases in which that which appears most eligible may not suit ihf situation or circumstances of the patient, it cannot be difficult to contrive other means of giving motion, so as least to incommode, and yet to give the greatest relief. A very gentle and long continued, or even incessant motion, may suit some cases better than any more violent and occasional agitation ; and in this way, probably, it is, that sea-vovaG;es have sometimes been at- tended with remarkable advaniai^e. LXVir. Comparative Tables of the Beats of the Tempered Consonances hi M. Kirnberger's and the Isoiojiic or Ecjual Temperament Systems of Tuning ; i/Jith Remarks on the cominon System ?ised by Organ Tuners, compared with thaf of M. 'Kir/fhrger, By the Uev, C. J. Smyth, Minor Canon of the Cat'icdral, Norivich. JL HE opinions of profound theorists are ever entitled to attention ; but sliould not be received with implicit faith. If such a man as Sir Isaac Newton was capable of a mis- take, so is an Emanuel Bach, or a Kollmann. To the latter gentleman the musical world is under the greatest obliga- iiouf for reducing tht theory of Composition to a degree of Modes of Tuning Instmments, 44^ of simplicity, before his writings unknown. But the opi'» nions he has advanced, wiih respect to the temperament of the musical scale, require that n)inute investigation and submission to calculation, which, if they had been advanced by a person of less celebrity, might have been passed over m silence. One of the grand objects at which he appears to aim, is to establish an equal temperament on the piano-forte (that is, that all chords of the same kind shall be alike, as to their degree of imperfection) : to this I raise no objection; the rage for modulation at present exertmg its energies, to their utmost possible extent ; a rage ;very favourable to the talents of those, who have not invention sufficient to pro- duce novel and beautiful melodies, and yet aspire to the character of interesting composers. I shall first presume to ofier a few observations on the tmequal temperament of Kirnberger, which Mr. Kollmann «

r»'e> '^ one of the best hitherto kjiown." Not having; the happiness to be able to read German, I know not what M. Kirnberger has offered in its behalf; or those impor- tant observations which major Templehoff (in an Essay in, that language published in 1775, Berlin) is said by Dr. Robison in the Encyc. Brit., art. Temperament, to have made, on Kirnberger's system. Preferring at all times experiment to theory, T tuned my piano-forte according to Mr. Kollmann*s printed directions, with a view to hear the effect of one of ^' the best unequal temperaments.*' I cannot speak favourably of the result. T will below subjoin a table oi the heatings of the tempered consonances, in order to give those professors who may feel no inclination to submit to the drudgery of calculation, some idea of what the effect of this temperament would be on an organ, where those heatings are most distinctly heard: a formidable host of foes, inimical to correct, and, even tole- rable tune. It appears to me, in the outset, doubtful whether a tempered system should have anv perfect chords (but the octaves); aa those chords, whenever ihey are h"ard,will render the ear less disposed to be pleased with the iraperfisct harmony which follows. We will suppose the performer on the 0T2;an, to begin with Kirnberger's system in the key of C, answering. to the tenor clif ; here is a chord absolutely perfect ; so also is the chord of G, the fifth of the key; but the chord of the fourth of the key ranks, in point -of importance, next to the key-note and its fifil^; and here unfortmiately is a chord of which A, the major third to F, beats 149 time». Vol, 3d, No. 146. June IS 10. Ff in 430 Modes of Tuning Instruments. in \o\ From ihe key of C a modnlaliou will naturally be expected into the key of G ; ^vhich modulalion will re- quire the donunant ot'G, viz. the chord of D with a major third, fifth, and seventh. Now the A is half a comma top flat, as A fifth above D, and will beat 73 times in \5^\ And this we may take, as the first instance of '' a very fine va- riety of pcrfcctioD." Surely Mr. Kollniann would have been more consistent in the use of terms, if he had said •* varieties of impv.'.rfcction." Tiie next chord which oc- curs is that of E, the fifth of which is perfect, but the major third beats 255 in 15'\ The chord of F has already been spoken of; proceed we then to examine the chord of Bb ; the titth is perfect, the major third beats 391>. This ojiord on El> beats 266. Now let us com[)are this temperament with that upon organs tuned in the usual manner. 1 do not give the beats in extreme keys, because they are too rapid to be heard as t'catings, except in the lowest part of the scale, and have a rough effect, which is more tolerable than beatings not loa rapd to be perceived as beatings. One chord, viz. that of Ab or G* has a peculiar character, (it is called the wolf) the fifth being almost the fifth part of a minor tone too sharpy and the beatings are distinctly heard in the middle and lower part of the scale. Chords on ihe Organ, as tuned in the usual Manner^ C, G, D, A, and E, good. B, F#^ C* aLid G*. The major thirds almost one fourth of a minor tone too sharp, and Ab (or G«) has also a fifth ahiiost F, Bb and Eb, good, one-lifth of a minor tor.e Joo siiarp, as before observed. When we hear an o?gan tuned in this manner, we may consider our'relves at a feast^ i\\ which there are dishes of various qualities j while in M. Kirnberger's feast of ffa;ry7//»v7^, viands, but eight dishes are very palatable, and those who are fond oi^ sour crout and oliveSy and, like many of our best ( omposcrs, have no objection to a slice of wolf, though ihey would not choose to dine entirely upon that outlandish aninjal, have an opportunity of gtatifying their peculiar palates. Until, therefore, some irrefragable arguments are produced, to prove the superiority ol M. Kirnberger's tem- perament to that in common use, 1 presume our organ- builders and organ-tuners will, in spite of any charges of obstinacy, ignorance, or policity, continiit: to tune as tlieir ancestors did before them : as I cannot flatter myself ih^ Modiss of Tuning tnstnlments. 451 pjablic will ever go to an enormous expense, for many ad- ditional pipes, in order that our old and young organists may perform their wonderful feats of modulation (which require as little genius as application) without torturing those who prefer tolerable tune, to the parade of science. Further observations, on mean-tone temperaments, may be offered hereafter. C. J. Smyth* M. Kirnberger's Temperament, Beats in 15' TThe Vibrations communicated by Mr. Faret.) Keys. Vibrations in 1". 3ds. lllds. 4ths. Vths. 6ths. Vlths. C 480 B 450 0 383 0 0 0 383 Bb 426-6667 474 399 0 0 574 399 A 402-4922 224 153 150 112 299 188 Ab 379*2593 383 355 0 0 510 355 G 360 399 0 0 0 533 0 Gb 337-5 188 287 0 17 0 287 F 320 355 149 0 0 474 300 E 300 0 Q55 112 0 0 255 Eb 284-4444 287 266 0 0 383 266 D 270 300 0 0 75 399 0 Db 252-8395 255 237 17 0 153 2S7 C 240 266 0 0 0 355 112 3131 2484 2484 279 204 36SO 2782 279 204 3680 2782 12560 Sum total -r i Ffd The 455 On Crystallography* The Isotonic Scale*', Beats in 15'', (The Vibrations communicatee] by Mr. Faret.) Keys. Vibrations in 1". 3ds. ' IITds. 4ths. Vths. 6th.v VIth«. c 480 B 433-0613 366 269 30 22 428 308 * 427-6307 345 254 28 21 403 291 A 403-6312 326 240 27 20 381 274 * 380*9784 308 226 23 19 360 259 G 359-5939 291 214 24 18 339 244 « 339*4127 274 201 22 17 320 230 F 320-3612 259 190 21 16 302 218 E 302-3819 244 180 20 13 285 205 * 285-4090 230 169 19 14 269 194 D 269*3913 218 160 18 13 254 133 * 254-2725 203 151 17 12 240 173 C 240 194 3260 142 16 12 226 163 2396 267 199 3807 2692 2396 267 199 / 3807 2692 Sum total. 12621 LXVIU. On Crystallography. %M. Hauy. Translated from the last Paris Edition of his Traite de Mineralogie. [Conunuedfrom p. 363.] GEOMETRICAL CHARACTERS OF CRYSTALS. 16. Forms, Nucleus or primitive form. It is very rare to find a mineral under its primitive form fiven immediately by nature, and there is a certain num- er of species in which this form is known only from the results of mechanical division and by theory. The just measurement of actions susceptible of producing it is only as * See our ixviihb volume, p. 65, and our xxixth volume, p. 347.— Edit. it On Crystallogi-aphy, 453 it were a point which frequently escapes in the process 6f crystallization, amid that multitude of circumstances which infliience in so many ways the progress of this operation* The diversity of the primitive forms ought to be re- garded as a certain indication of a difierence in nature be- ' tween two substances, and the identity of primitive form indicates that of nature, at all times when this form is not one of those which have a marked character of regularity, such as the cube, the regular octahedr«)n, &c. Secondary forms. In order to describe more easily the secondary iornis, we shall suppose them always situated in such >a mariner that the line which may be considered as their axis has a vertical position, and then the faces parallel to this axis will themselves bear the name oi vertical faces ; we shall call hmizotital faces those which will be perpcn- dicular^ and oblique faces [host which will be inclined to- wards it. We are sometimes in the situation of indicating the in- cidence of a face which is presented in front in the pro* jection of a crystal, on that which is adjacent to it behind the same crystal. We shall then give to the latter the name oi returned fnceL Suppose, for example, that in the distich topaz represented flJg. 61, PI. VII) it is requisite lo indicate the angle formed by one or other of the panes o, o, with that which is contiguous to it in the posterior part, we shall say that the incidence of o on the returned pane is 93° 6'. The forms of crystals are subject to various kinds of al- terations purely accidental. One consists in certain laces being nearer to, or more distant from, the centre in one crystal than in another which belongs to the same variel^'i in such a way, however, as constantly to preserve a certain character of symmetry. In several cases these variations only fall on the dimensions of the faces, and not on the number of their sides. This happens with certain dodecahedral garnets, which in the case of perfect symn^etry would have ttieir surface composed of twelve equal and j^imilar rhombs, and which are lengthened in the direction of an axis which would pass by two of their opposite solid angles taken among those which are formed of three plane angles. The dode- cahedron is then presented under the appearance of a solid with six panes which are elongated rhombs, with summits of three faifes each which are true rnombs. In other cases, the faces tnemselve*^, or some of them at least, change theit figure, by the increase or diminution of the number of F f 3 their 454 On Ci'ystallographi/, their sides. Thus, upon the hypothesis that the cube per- forming the function of the primitive form undergoes a decrement by a simple range around its eight sohd angks, it may happen that the effect of tlie decrement remains m- terrupted, at the term at which all the faces which it pro- duces are eq\iilateral triangles far enough removed from the centre to avoid meeting, and then the faces parallel to those of the primitive cube will be octagons. If, on the contrary, the same faces come in contact, the primitive planes will preserve the form of the square : finally, if they intersect each other, they will be changed into hexagons, without the primitive faces ceasing to be squares, and these variations might pass through an infinity of degrees which will be as many approximations, with respect to the form of the complete octahedron, which is the object towards which the law of decrement tends. But amid all these diversities of positions, the mutual in- cidences of the faces of the crystal are constant. This truth, which has been placed beyond all question by the numerous observations of Rome de I 'Isle, is a necessary consequence of the integrant molecule being itself invari- able in its form, and also from the law of decrement in its turn having a constant progress, which is only arrested more or less far from its limit in the different crystals re- lative to one and the same variety. A second cause of variations is that which disturbs the symmetry and regularity of the crystalline form, and the effect of which is to destroy the equality of the analogous faces, in such a way that some take a very visible extension, while otherg almost entirely escape the eye. The ifieory ought to make an abstraction of these variations, and re- gard them as null : but they are visible enough to confuse the mind of a person not much habituated to these exer» cises, and who cannot easily distinguish the type from the true form through the traits which disfigure it, and this is the source pf the greatest difficulties which the study <>f crystallography presents. The projections traced from re- gular crystals, and the copies in relievo of these bodies, may be of great use to the naturalist, in order to bring back the rest, by an exercise of imagination, to the symmetry from which they are separated. These imitations of the work of nature will serve to obviate a difficulty of another kind, namely, that which arises from the grouping of crystals partly concealed by pach other, or from their slight projection above tiie mar On Crystallography. 455 trix, in which they seem to be more or less fastened, so that it l)ehnv'js ai^ observer to complete, in his imagination, each of ihtf-o partial lorms. (n short, I have been more ihan once surprised to see with what Facility vonng mineralogists, who have joined to a tasic tor the science an aptitude for geometrical con- ceptions, have referred every thing to its right place in crystals the faces of which were the most deranged, or have profited from the trifling part of a crystal sunk in its matrix, fn order to guess at the rest. It would even seem thai there is a peculiar satisfactiou attached to the solution of these small problems : every person is pleased uith giving proofs of sagacity, and with understanding Mature as if by half a word. In order to determine the mut«al incidences of the faces of a crystal, or of its salient angles, an instrument is used which was invented bv M. Carangeau. This instrument, which strongly rcsenibles the graphometer, is composed of a semicircle MTN (t brass or silver, divided into degrees, and which has f.vo arms A B, FG, one of which V Cy is slit from u to R, excepting at K, where a small piece is left unslit in order to give more solidity to the instrument. This arm is attached at R and at c to a brass rule situated behind, and winch is of a piece with the semicircle. The junction of the arm with this rule is produced by means of two screws which are inserted into the slit. The other arm A B is slit in the same manner from X to c, where it is attached abo /c the former by means of the screw at this place, and which traverses the two slits. On loosening the screws, we can shorten at plea- sure the parts c G, c B, of the two arms, as circumstances require. The arm AB having only a single point of attachincr at c, where the centre ot" the circle is, has a movement around this centre, while the arm G F remains constantly in the direction of the diameter which passes by the points zero and 180°. It may be useful to remark, that the upper part of the arm A B ought to be bevilled ofl* towards its edge sz^ the direction of which being prolonged bciow, pa-ises by the centre c of the instruiiient. The reason of this is, that this edge is what is called Hie index line ^ i. e. that which indi- cates on the Q;raduated circund'-'renee the measurement of the angle wanted. Let us now suppose that we wish to measure on a crystal jthe angle formed by twoadioining plants. \Vc know that F f 4 ^ thi$ '450 On Crystallography . this angle is equal to th^t of two lines drawn from one and the same point of ihe edge which joins these planes, with the condition that they are perpendicular to this ridge and laid down on the same planes. In order to have this ^gle, we shall arrange the instrument so that the portions c G, c B of the two arms may leave no lii^ht between them and the planes in question, and at the same time iheir edges ma) be perpendicular to the edge of junction. In this case, the faces wh.ch embrace the crystal are tangents to the two planes whose incidence we seek for. This being done, we shall seek on the circumference of the instrument, the degree which the index hue sz marks, or the angle which this line forms with that, which passes by the centre c and by the zero point, which angle is equal to that formed by the two portions' G c, cB of the arms, since it is opposite to it at the summit. It is an advantage to be able to shorten these parts at pleasure, to avoid the obstacles which would render the operation impracticable, and which might be occasioned either by the matrix to which the crystal adheres, or from the adjoining crystals in which it is partly fastened. But there are cases in which this precaution is not suf- ficient, and in which we should find ourselves constrained by the part of the semicjrcle situated towards M, if its position was invariable. The ingenious inventor, of the instrument has guarded against this inconvenience by the following contrivance. . The stalk at c has, besides the two arms, a stay or rod of steel placed below the copper rule on which the arm GF is immediately applied. The upper extremity of this rod, or that which is situated towards O, has a hole into which a steel peg also enters, furnished with a screw in a similar manner. In addition to ttiis the semicircle is di- vided at 90% so that, by means of a hinge with which it is provided at the same place, the quarter of the circle TM is folded below the quarter of the circle T N, and is as it were suppressed. When we wish to e;(ecute this move- ment, we must loosen the screw which fastened the upper '^^art of the rod cO, we must disengage the hole at the end pf this rod from the screw which is inserted into it, and •we must pull down the rod until it is beneath the copper rule ^.hich has the arm G F. When the angle measured exceeds (>0^, we must return the quarter circle TM to its* place, in order to ascertain its value. It will be easy to appi-eciate the utility of the goniometer, if we reflect how inteicsting it is that descriptions of cry- stals On Crystallography, 457 stals should indicate the angles which their faccg m;ike with each other. Such are the indications which niake the dcscri|)Uou Start up, as it were, hy palpable and truly cha- racteribtic traces. Without these requisites, a de^eription would be a rude and imperfect sketch, which nnght be re- iern d to many diiferent ol)ject8. 'rhus v/e do not describe dodee.ihedral zircon v\ hen we merely sav that it is a prism with lour panes ternimated by summits with four rhombs which arise on the longiiudinal ridires. This character would also suit the harmotome '(the cruciform hyacinth), the htilbile, oxidized tin, i^cc. : but if you add that the panes form right angles with each other, and the fares of the summit are inclined to taclf other by 124° 12% the description will be restrained to zircon. If you say that the inclination is 121" b^\ it will be the harmotome ; or, if you say that there are two dif- ferent inclinations, the one 123'' 32\and the other 112* 14% it will be the siiibite. There are several varieties of one and the same substance which may present forms of the same kind, and wh.ch will only be distinguished by the measurements of their angles. Of this description are the six rhomboids on one hand, and on the other the two dodecahedrons with rhombib faces which are found in carbonated lime. How can we exactly describe all the varieties which differ froui each other more or less, if we do not precisely mark the dif- fereiKt s ? And there are even cases in which the use of the gomometer is the only vva\ to avoid an error which would not -fair to slide into the description. -Thus the calcareous rhon^^boid, the angles of- which only differ ia about 2 : 18' from the right angle, w^as at first taken for a cube, and wouhl have continued to be called cubical calcareous spar, if geometrical measuremenis had not rec- titied ihis denonhnarion, doubly deieciive, either in itself,' or with relLienee to the theory which demonstrates tiiat the existence of" the cube does not agree here with that of any symmetrical laws (if decrc^mtnt. One of the principal cau>es of this neglect o? gonio- metry arises from the kind of rule to w-hkCh some mmera- Jogisis are restricted, of con lining tlicmselves to cnaracters susceptible of being dttermineci solely by a refercrce to the senses : and .on this account we are deprived of the re- sources presented by the instrumeiits \'. hich g.ve to our organs a new degree of d iicacy, and render them capable of attaining, in the dctennniation of the distmguishing characters of minerals^ that precision which is in its turn tne 438 On Crystallography , the principal character of the sciences. I have known some admirers of simjile and imaided ocular demonstra- tion, nevertheless, approve of using an eye-glass. Now what is a goniometer but a kind of {geometrical eye-glass, which enables us to percci^^e those minute diflerenccs, and imperceptible gradations, which escape the eye? With respect to ])lanc angles, we have sometimes indi- cated them also*, particularly those of primitive forms, and those which imprint on secondary forms a character of simplicity and regulariiVj such as the angles of 90°, 60\ 8cc. We shall conclude from what precedes, that every cry- stalline form, when we consider only what is invariable in \t,i.e. the number and the respective inclinations of its faces, is so truly characteristic, that it may serve of itself to determine, independently of every other consideration, the species to v/hich the crystal belongs that presents it, provided it be not a cube, a regular octahedron, a regular tetrahedron, a rhomboidal dodecahedron, or a regular hexa- hedral prism. Thus the form '^f the dodecahedron with triangular scalene faces inclined arriong each other alier- iiately by li4" 2(/ 20'', and 101" 28' '40", indicates by itself a variety of carbonated lime. Hence it would be possible to compose a method, by means of which, any crystallirve form bejng given, we might succeed in ascertaining in what species if ought to be placed- It is easy to perceive, that by considering the faces of crystals relative to their number which varies froin four to 60 and upwards, with ihcir vertical positions, inclined or horizontal, with the other modes of existence of which they are susceptible, we should have divisions and subdi- visions so much the clearer, if geometrv was called in to determine and circumscribe ihem. A method of this kind would be purely factitious, but it would fulfil its principal object : and we might even conceive that a geo- iDctrician with its assistance, who was no naturalist, and who had only before his eyes the collection of crystalline forms executed in wood, might succeed in arranging this eollection. There would only be the forms conmion to various species which would lead to several names, amoiig which we could only choose from the inspection of th« natural crystals, by combining with the form a second • V\e may nensurc these anHes by means of a card properly cut, or by tn^'o very thin rules of steel; whicji turn on each other by means of a hinge, character On CrystaUographj . 459 character on which the last step would dcpciul, by which to attain our object. Thus the tnste joined to the cvibical form would instaiiilv indicate inunatc oFsoda. A metallic colour of a bronze yellow reflected by a body oi' the sauic form would characterize sulphurated iron. I". Struciure. Mechanical Division, The character furnished by this operation is, as we have already re- iTiarked, the onlv one which does not participate in the variations produced by the mixture oF heterogeneous sub- stances, the influence of" which modifies the hardness, spe-ific gravitv, fusibility, &c. and even the results of the analysis. It n»ay perhaps disappear in the unshapen masses which have undergone a confused crystallization ; but wherever it is possible nicrely to have a glimpse of it, it is susceptible neither of more nor of less. It removes in some measure every thing which is merely accessary in the composition of a substance; and uhite in alt other respects this substance marches through a succession of shades, the measurement of the primitive angles stops at the same degree ; and as soon 'as the substance changes its nature, there is an abrupt leap in the value f)f the ancles. VVe may venture to hope, iftat those who peruse this treatise with attention will perceive the advantage which we have made of the character in question, for the deter- mination of the species. In our lirst researches we had nothing further in view- than to make it the basis of a theory fitted for throwing lights on crystallography. But the various applications which we have made of this theory led us to exclude from such a species crystals uhich h.ad been rei'erred to it, and which rejected the laws of structure of which the forms relative to this species were suscepti- ble; whereas other crystals, hitherto placed in diiVcrent species, were subject to laws which solicited ihcir iiuin^acv; and fron) that moment we conceived that this theorv, \vhii7h at first appeared restricted to a simple branch of mineraloefv, could extend its influence to the whf)le science, and con- tribute to give more regularity and justness in the distri- bution of the subjects which it embraces. IS. Fracture. This ouglu not to he confounded with structure. Having broken a mineral, wlien we |)erceive internally a scaly, granulous or fibrous texture, this is the cflect of an arrangement which preexisted in- the body. But if we find an undulated surface, or a species of small .scales, which are nothing else than vcrv thin frai^ments, ^\\\\ partly adhering to the substance, this aspect is the effect of fracture. But as it depends origii>allv on a certain mode 46o Royal Society. mode of aggregation, it is generally discovered in al! the pieces of the same substance, and it is this which may serve as a character for recognising it. Minerals in which there is wanting some one of the sections nticessary for completing the primitive form, pre- sent a fracture properly so called at the place where these sections ought to exist. For example, in the amphibole, the joints parallel to the panes of the prism are very di- stinct, whereas we perceive none in the direction of the bases ; so that the crystal is broken, instead of allowing itself to* be divided in the same direction. There are there- fore, in these cases, longitudinal joints with a transverse fracture. In other cases trhe joints are parallel to the bases, and the fracture is longitudinal. We shall point out the different directions according to which the fracture takes place; and when ihere will be no joints visible in any di- rection, as takes place with respect to agate-quartz, we shall say that the fracture is indefinite. [I'o be continued.] LXIX. Proceed'mgs of Learned Societies. ilOYAL SOCIETY. JVlAY 31. — The conclusion of Mr. Home's paper on the organs of q^eneration in ovi-viviparous animals, particularly the squalus or shark genus, and the opossum, was read. Mr. H.*s observations chiefly applied to the squalus acan- ihius, or picked dog-ti.sh, conimon on the shores of Nor- folk; a.id the kangaroo, particularly the latter, the young of which not deriving its nutriment by a navel-string, or from the uterus of its mother, is supported by external agents, of which air forms an essential part. He also no- ticed the fact, that fish deposit their eggs on rocks and plants near the surface of the water, which there contains ■more atmospheric air, and thkt this air is necessary to the life of the young fish, which are enveloped in a gelatinous fluid. June 7, — was occupied in reading Mr. Brande's appen- dix to Mr. Home's paper, consisting of a chemical analysis of the peculiar gelatinous-like matter in which the ova of sharks, spawn of frogs, &c. are nourished. By the friendly assistance of Sir Joseph Banks, Mr. B. obtained some of what is called star-shot jelly from Lincolnshire (that sub^ stance found near marshes, which Mr. Pennant justly con- jectured to be the excrement of herons after feeding on frogs) ; the matter which envelops frog-spaAn, and that which Royal Society. 461 -which includes the 6va of sharks : these he respectively analysed^ and found them to possess similar properties, but all very different from gelatin, however analogous in their external appearance, and which he concluded to be a pe- culiar animal innttcr not yet described. This jelly-like matter is insoluble by water, but it absorbs water in great quantities, and iaecomes proportionally enlarged in conse- quence: acids and alkalies, however, dissolve it; but in. none of its characters does it evince any identity with ge- latin or albumen. A mathematical paper on multi-nomials, by Mr. Knight, was communicajed to the secretary (Mr. Davy), and laid before the society ; but it was not of a nature to be read. Mr. Hubbard communicated a letter from Sir John , containing a plan fur purifying the air of coal-mines. The author, having observed that workmen descend into wells with the greatest safety after throwing a quantity of water into them, proposes the like expedient to purify coal- mines, by projecting water, in quantities sufficient to absorb the choke-damp (carbonic acid gas), against the cieling of mines, by means of an instrument like a fire-engine, made with an end like that of a watering-pot, to throw the water like a shower-bath, and thus present the greatest possible surface to the noxious air. This machine, the writer con-' eludes, might be both supplied with water and v/orked by the steam-engines in all coal-mines. Several other minute operations and less important advantages were stated as likely to result from the adoption of this plan j on con- cluding which^ the society adjourned till June 21. — when a part of a, paper by M. Delille, translated from the French, was read, describing the lohan upas, or poison-tree, of Java. The author is a French physician, a member of the NationalTnstilute of Egypt, and transmitted this paper from the East Indies to the Royal Society, by means of an English lady. The botani- cal account of this poisonous plant he received from one of the French naturalists who accompanied Capt. Baudin, ^nd who resided sometime in Java; where he visited the interior of ihe country/ and with much difficulty succeeded in prevailing on the natives to show him the different poi- son plants, which they carefully conceal in order to use them diu^ing war. Hence the reason of so many fables as have been repeated respecting the extraordinary destructive- ness and influence of the zipas, which in the language of the Javanese signifies vegetable poison, and is applied only' to the juice of the bohan tree, and atiother twisled-stemnleci plant. 46ff Royal Society. plant. The bohan is a large tree, which this writer (i(Jii» siders a new genus : the other plant, yielding an equally powertul poison, is ol the woodbine genus. 'J'he vpas, or poisonous juice, is extracled by an incision in the bark with a knite, and carel'ully collected and preserved by the natives to be used in their wars. As to its dilfusing noxious efflu- via in the atmosphere, and destroying all vegetation around it, the absurdity of these stories is best exposed by the fact, that the climbing species requires the support of other plants to attain its usual growth. Dr. Delille made several experiments with the upas on dogs and cats. An incision was made in the thigh of a dog, and eight grains of upas dropped into it : shortly after the dog began to vomit, and continued vomiting at intervals, till he became convulsed, the muscles of his head greatly distorted, and he died in 20 minutes. Six grains were put into the thigh of another dogi which also vomited first his undigested food, next a white foam, and died contracted and convulsed in 15 mi- nutes.— A cat was also treated in like manner; but she was still sooner and more convulsed, and her nmscles con- tracted : she continued leaping up for a few minutes, and fell down dead. All these animals died crying and in great agony. — After repeating a number of experiments on the deleterious and prompt effects of this powerful poison when applied externally ; the author gave a grain and a half to a dog, which he took into his stomach, but it only pro- duced a slight purging. To another four grains were given, which in about four hours produced both vomiting and purg- ing, and the dog died in the course of half a day. On examin- ing the bodies of these animals after death, no very extra- ordinary appearances were discovered; the ventricles of the heart were full of blood, and some slight traces of inflam- mation appeared in the stomach; but "the derangement was not so great as might have been expected from such a violent and sudden death. From this circumstance, the author concluded that the absorbents had transmitted the poison to the nerves of the stomach, and that this peculiar vegetable poison acts exclusively on the nerves. *^* In the account we gave (in our last number) of Mr. Macartney's paper on luminous animals (not insects nierely) there were some mistakes. He stated that they belong to several classes, as mollusca, insects, worms and zoophytes*-— There is but one species of mollusca luminous, the pholas dactylus. The medusie that were ranked by Lmnaeus amongst mollusca are now placed more properly with zoophytes. — Th$ medusa scintillans, one of the lu- mi nous Eoyal Tiistilution, — Wernerian Nat, Hist, Society, 4<)3 niinoiis ?|)ecies, was not given to Mr. Macartney by Capt. Jlorsburg, but discovered by himself. The pyrosoma at- lauticiim of Pcron was called, in our account, the pyro- soma allant'ica ot Perot, A great part of Mr. Macartney's interesting paper is lakcii up with the anatomical description of the organs from whence the light issues in certain species. ROYAL INSTITUTION. In the concluding lecture at the Royal Institution, the large V^oltaic apparatus, consisting of 2000 double plates of four inches square, was put into action for the first time. I'hc effects of this combination, the largest that has ever been constructed, were, as might have been expected, of a very brilliant kind. The spark, the light of which was so intense as to re- semble that of the sun, struck through some lines of air, and produced a discharge through heated air of nearly three inches in length, and of a dazzling splendour. Se- veral bodies which had not been fused before, were fused by this iiame ; the new metals discovered by Mr. Tennant, iridium, and the alloy of iridium and osmium. Zircon and alumine were likewise fused; — charcoal was made to evaporate, and plumbago) appeared to fuse in vacuo. Charcoal was ignited to intense whiteness by it in oxy- nuiriatic acid gas, and volatilized in it, but without eiTcct- ing its decomposition. A large Leydcn battery, conlaininfr 24 coated jars, was charged by a momentary contact of the wires to a degree that reqiured from 20 to 30 turns of Nairne's electrical machine of eight inches diameter. All the electrical phienomena of the passage pf electricity to a distance; the discharge through aTorricellian vacuum; the attractions and repulsions of hght bodieSjWere denjonstrated in a distinct way by means of this apparatus. It may be hoped that the apj)iication of so powerful an instrument, and such easy methods ot producing the most intense heat,, will lead to some new tacts in analytical science, WERNERIAN NATURAI. HISTORY SOCIETV. At a meeting of this Society, 19th May last, the Rev. .Tohn Fleming, Brcssay, read an account of several rare ani- mals found by him in Shetland, particularly Plturonectes punctatus,a specimen of which he exhibited to thaSociety ; Luccrnaria quadricornis; Echinus miliaris, &:c. ; and some nndescribed species, particularly a Flustra, which he pro- posed to call flustra Rilisih in honour of Mr. Ellis, the illustrator 46 i French Nationallnstitute, illustrator of the corallines. — At the same meeting, Dr» John Barclay read remarks on some parts of the structure of the large marine animal cast ashore in Stronsay last year. At a meeting on the 26th May, Dr. John Yule read a summary of experiments and observations on the germina- tion of the GramincaPj in which he stated some new facts respecting the oeconomv of this useFul class of plants, il- lustrated by a series of drawings and specimens of the ger- minated seeds of the Cerealia or cultivated species ; and of the buds of the stem, and panicle of viviparous Grasses. — '<- And the secretary read a communication from William Fitton, esq. on the porcelain-earth of Cornwall. FRENCH NATIONAL INSTITUTE, [Concluded from p. ^99.] Messrs. Majendie and Delisle have communicated to th^ clas^:; their experiments made on animals by means of the matter vvith which the natives of the Isles of Java and of Borneo poison their arrows. [See Royal Society, two pages back.] M. Vauquelin has also made some experiments of this fanufacture of tht arhphori and alcazaras used by ihe Spaniards for keeping their liqhors cool, has communicated them, with the addition of some ini port ant reflections as to the utility of these ves- sels, and on the influence which they exercise on the li^ quids they' cohuin. LXX. 'N'olkes C 467 ] JLXX. Notices respecting New Books, U .R. LEYBOtJRN, of the Rov^.! Military College, has just published the tenth number of the Mathematical Reposi- tory» coutaining solutions to the mathematical questions Uroposed in the eighth number, and a scries of new questions to be answered in a subsequent ??an\ber; an essay on polygonal numbers ; a new demonstration of the binomial theorem; an illustration of the forty-seventh pro- position of the second book of the Principia ; a curious indeterminate problem; solutions to a curiouF. problem in dynamics ; and a continuation of Le Gendre's memoir on elhptic transcendentals. Mr. W. Moore, of the Royal Military Academy, has in ft good state of forwardness, A Treatise on the 'doctrine of fluxions; with its application to all the most useful parts of the true theory of gunnery, and other very important matters relating to military and naval science. The fluxions will be preceded by such parts of the science of mechanics as are necessary for reading the wor^c without referring to other authors ; and the whole will be so arranged, that any person moderately skilled in algebra, geometry, and trigono- metry, and having a knowledge of the most common pro- -perties of the conic sections, may proceed to these inquiries •v/iih every interest and success. The whole will be printed in one volume octavo, and will be particularly adapted to -all military institutions of eminence. Mr. Marrat, of Boston, Lincolnshire, has in the press a work on mechanics, which is principally intended for •the use of schools, $cc. The author*s principal aim in composing this work, has been to make the subject easy to be understood by students, •to facilitate the business of instruction, and to condense as much useful matter as possible into a small compass. In order also to blend theory with practice, and to remove the irksomeness which students mostly complain of in study- ing the theory, a great number ofexarnples w\\\ be given in ahnoyt every section ; these will be found of service iri fixing the principles in the mind, and cannot fail of ren- dering the subject more easily attainable, ^rid_, conse- quently, of creating ;i stimulus to further ex^rtiqns. , The work will be divided into five books ; the first of which treats of statics, the second of dynamics^ the thir^ Og2 ' of 46s Intelligence atid Miscellaneous Articles. of hydrostatics, and'' the fourth of pneumatics. In these four books the subjects are prosecuted as far as could be dqne without introducing the fluxional calculus ; but to render the work of more general utility, and to accommo- date students in the higher classes, a fifth book is added, ill which several branches in the preceding books are very much extended. The work wilt be comprised in one oc- tavo volume, and will be accompanied by thirteen copper- plates. M.ViBOUG, professor in the Royal Veterinary School, in Sweden, has published a dissertation " On the use of the flesh of horses/' — The publication of this paper has had the effect of introducing: the use of this article as food throughout Sweden, and the butchers' shops are now sup- plied with the carcases of horses, in addition to those of oxen. M. Viborg assures his readers, that the flesh of those animals, when roasted, is preferable to that of oxen. LXXI. Intelligence and Miscellaneous Articles, DE LUC'S ELTXTRIC COLUMN. J- HE small bells noticed in our last three numbers, still continued to ring on the 25th instant (June), as they had done since the 23th of March, without being known to have once ceased ringing. We are happy to be enabled to add, that those who wish to possess electric columns, fitted up in the form of rod.-^, as described in our number for March last, may obtain them of Mr. Blunt, optician, Cornhill. The success of the several charitable institutions for the relief of the indigent blind, has suggested the humane idea of bringing forward, for the equal relief of their opulent brethren in this country, a plan, similar to that by which M. Haiiy, in Paris, taught them, several years ago, reading, writing, arithmetic, music, and the rudiments of the sciences generally. LOCUSTS. Rome, 29th May, 181C. For some days past crowds of people, excited by curio- sity^ have been thronging the b'anks of the Tiber to wit- ness a singular phaenomenon. A wind from Africa has brought into these countries an immense swarm of locusts. These insects, having wasted the country, and now unable to find subsistence, have waged war among themselves, and devour each other. The weaker party take flight, and, pur- sued Intelligence and Miscellaneous Articles, 4Q9 sned by the vanquishers, throw themselves in myriads into the Tiber. The day before yesterday this river was covered w ith them. Ucport to the Committee, of the Honourable House of Com- 7nons, on the Fefition if the Trustees of the British Museum; respecting the Purchase of Mr. Qreville's Col^ lection of Minerals, London, May 9, 1810. We the undersigned, liaving been requested by the com- mittee of the honourable hous^e of commons, on the pe- tition of the trustees of the British Museum, to make a careful examination of the colitction of minerals belonging to the right honourable Charles F. Grcville, and to put a value upon the same with as much fairness and accuracy as possible ; — have now to report : First. — That on the 2d of this month we assembled at the house of the late Mr. Grcville on Faddington Green, commenced our inspection of the collection of minerals ; and continued the same, day after day, up to the yth in- stant. Second. — That we have found the specimens scientifi-. caily arranged, for the greater part, in glazed drawers,' which are contained in cabinets miide of beautiful maho- gany. Third. — ^That, exclusive of tbe^e cabinets, there are two others, containing models in wood and in clay, the for- mer having been most accurately made by the Count de Bournon tor the late Mr. Grcville, exemplifying and elu- cidating the various figures and modiiications of crystal- lized mineral substances; a series of great importance to mineralogical science. Fourth. — That, m addition to the minerals contained in the drawers, there are arranoed on the upper part of the cabinets manv lariie anJ niai'iiificent specimens, several of which are uneommonlv rare and highly valuable. Fifth. — ^That the whole collection consists of about 20,000 specimens. Sixth. — 'I hat the specimens in gejjeral throughout the collection appear to us to have been scleeted with very great judgement, both as to their utiliiy and beauty. Seventh. — That the series of crystallized iiibics, sap- phires, emeralds, topazes, rubeilites, diamond^, and r»''e» cious stones in general, as well as the series of the vi tons ores, far surpass any that are known to us in the diticrent European collections. Gg3 Eighth. 4ff> List of Paients foj' liew Inventions, fcighth. — That \ve consider the entire collection to he ^qual in most, and in many parts superior, to any other similar collection which any of its have had oppt)rtunitie3 of viewing in this and other countries. Ninth. — That having accurately examined and ?oparat^ly ir^llued the diflfereiit cabinets and detached specimens, vvc find the total aniount to be thirteen thousand seven hundred and twenty -seven pounds, j£'l3,7^)7. Wm. Babington. RoBEiiT Ferguson. L. Comte De Bournon. Charles Hatghett. Richard Chenevix. Wm. H. VYollaston. Humphry Daw. We whose names are underwritten, and who have sigfted the foregoing report, think it but an act of justice on ouf Jjart, to request permission to state to the committee the very great services which have been rendered by the Count de Bournon, during the whole of the inspection jthd valuation of the collection, with which he alone was well acquainted, having principally contributed to form it, and having bedn occupied for several years in arranging it for the late Mr. Greville. Wilh^^ut the able assistance of the Count de Bournon, so justly celebrated for his profound knowledge in mineralogy, *the inspection and valaatiori Vvould have required a very great length of time, and after all would most probably have been less accurately performed. We therefore unanimously concur in giving this public testimony to the merits and services of Count de Bournon. We also have to make our acknowledgments to Mr. Lowry and Mr. Jonville, who obligingly attended the in- spection at our request, ^nd rendered us much valuable ?^s- sistance. Wm. Babington. RosERt FERGusot?. Richard Chenevix. Charles E^a ichett. Humphrey Davy. Wm. H. Wollastqn. LIST OF patents FOR NEW INVENTIONS. To Joseph Halliday, master of the band belonging to the Cavan regiment of militia, for certain improvement? in the musical instrument called the bugle horn. — May 5, 1810. To William Chapman, of the town and county of New- castle-upon-Tyne, civil engineer, for a wheel or wheels to be moved by water, steam, or any other suitable fluids or gases, and to be applicable to mechanic or other purposes where a moving force is required. — May 9. To John Bosworih_, of Biimingham^ in the county of "VVarwiQki List of Tatentsfor new Inventions, 471' Warwkky coal cksler, for ira proferments in carriages fo facilitate the unloading of heavy coalt and other things.— May 0. To Sir Isgac CofRny bart. vice admiral of the blue squa* dronywho, in consequence of a communication to him by a cerla'in person residing abroad, is become possessed of i new invention of a perpetual oven for the making of all kinds of bread, apateni for the same, dated the 15th of May. To Jajiies Eel), of Fieklgaie- street, Whitechap 1, sugar- refiner, for his certain iniprovements in the manner of refining sugar, and of forming sugar loaves of a particular jJdscfiption.— May 17* To Charles Stewart, of the parish of St. Ma^^tin in the Fields, iu the cotinty of Middlesex, cabinet-maker, for cer- tain improvements in the construction of dining- and other tables.-— May 22. To John Onions, of Broselcy, in the county of Salop, iron-master, for his machine for thrashing corn and other grain, on a new construction. — May 22. To William Docksey, of the city and county of Bristol, millwright, for improvements in the proce^^s of manu- facturing an article commonly called ivory black, and for pulverizing, grinding, or reducing to a subtle and fine pow- der, all articles cap^ible oT a more easy separation of their parts or constituent principles by lorrcfaction, heating, or calcination in open or close kilns, ovens or furnaces, espe- cially potter's clays, flints, colouring and glazing materials* -^May 22. To Joseph Anthony Berrollas, of Cowper*s-row, Clerken- well, in the county of Middlesex, watchmaker, for his warning^ watch on a new construction. — May 26. To George Hickford, of Chadacre- Hall-Farm, in the parish of Strumpling, in the county of Suffolk, farmer, for his improvements upon the plough heretofore used for draining land, and the machine for drawing the same through the ground, whereby a horse will be able to per- form a much greater quantity of woyk in thp same time than by the methods now in use. — Jime 8. To John Williams, of Cornhill, in the city of London, Stationer, for certain apparatus or additional parts to be ap- plied to and used with wheel carriages in order to render the same more safe and commodious. — June 8. To Mary Townley, of Ramsgate, in the county of Kent, for the prevention or cure of smoky chimneys. — June 8. To Arthur WoolF, of Lambeth, in the county of Surry, engineer, for certain improyemenU in the construction ani working 472 Lisl of Patents for new hiveniloHs, working of steam engines, calculated to lessen the con- sunipti(»n of fuel. — June 9. , . To Joseph Warren Revere, of Poston, in the United Stales of America, at present residing ju London, for a new and improved method of spliiiing hides and shaving leaiiicr — June 10. To Joseph Clsild Daniell, of Frome, in the counlv of Somerset, clolhicr, for certam improvements on machmes called gigs and shearing frames, used ior drei»smg cloths, and in li^e clothing manufactory. — June 19. , To Malcohn IVf'Gregor, of Viell Yard, Carey-street, in the county of Middlesex, nmsical instrument maker, for certain fiiite or musical wind instruments with improved keys, which keys are also applicable to tlutes and various other wind ini^iruments now in use. — June 19. To George Adams^ of tin- VVoodlamls, in the parish of Liiidridge, in the county of WorceUer, faimer, for an im- proved method of cultivating of land, and of feeding and 'consuming the produce thereof hy cattle and. sheep, and of preserving and applying the manure of and made by such cattle and sheep, by means of certain houses made and built for the protection of cattle and sheep from weather, and feeding the same thereon, and moveable by nieans of wheels, slides, iron railways, or otherwise, invented and found out by him. — June 19. To John Lincisey^ (late lieut. -col. of the Tls^t res^t.) af Grove House, in the county of Middlesex, for his boat and various apparatus, whereby heavy burthens can be con- veyed on shailoW water on tivers wherein shoals and other tiifficulties imjK^ie navigation, whereby the lives of men will be saved from wrecks and other situations of immi- nent danger at sea or on rivers, whereby the apparatus above specified n)ay, in its consequences and constructions, embrace other important results highly beneficial to the British navy and commerce, by enabling the bottoms of «hips to be examined with accuracy and expedition without the neressity of moving the masts or cargo. — June I9. To William Bell, of Handsworth, near Birmingham, in the county of Warwick, engineer, for his improved machine for the purpose of cutting pasteboard, or cards out of pasteboard ur paper, and for cutting various other articles. — June 19. To Janus Frost, of Little Sutton-street, Clerkcnwell, brass-fo!i;.:!' r, and James Frost the younger, his son, also brass-founder, for improvements upon cocks, or an im- proved lock cock. — June 32. / meteOro- 'Meteorology, 47a meteorological table, By Mr. Carey, op the Strand, For June 18 JO. ' Th ermometer. Height of •ne Barom. eesofDry- by Leslie's rometer. D.iys of Month. c s - bJi Weather. ^ '^^ Inches. &e| oc '^ " 0 c E Mav 27 47 60« 46*^ 29-95 40 Fair '28 48 56 45 30-13 53 Fair 29 46 51 46 •40 71 Fair 30 49 65 51 •30 66 Fair 31 52 66 50 •30 60 Fair 1 53 65 52 .09 77 Fair 2 54 69 54 •25 79 Fair 3 53 66 50 •22 63 Fair 4 52 65 55 •20 90 Fair 5 54 55 50 •24 41 Cloudy 6 51 70 55 •19 79 Fair 7 54 67 56 •n 55 Fair 8 56 70 60 •05 76 Fair 9 59 73 55 29-94 52 Fair 10 59 70 53 •72 41 Clou J V II 58 63 54 •82 53 Fair 12 54 66 53 •94 59 Cloudy T3 55 60 ' 50 •S5 0 Rain 14 50 63 54 30- 1 5 70 Fair 15 54 66 51 •19 79 Fair 16 52 62 46 •03 55 Fair 17 50 60 54 29' 95 51 FaiF 18 56 70 60 •95 65 Fair 19 60 70 60 •95 51 Cloudy 20 63 72 63 •95 42 Cloiidv ■ 21 64 77 66 39-20 92 Fair . 22 66 73 55 •30 55 Cloufly . 23 54 69 55 •38 57 Fair 24 56 73 60 •25 61 Fair 23 59 73 66 •09 77 Fair 26 59 61 55 •05 "°i Cloudy N. B. The Barometer's heif»-ht is taken at one o'clock. ERRATUM. !n Mr. D»vy'» article (see page 409) for Plates IX and X, read Plates XH u-.d:f;ij. t 47* 3 INOEX TO VOL. XXXV. MCCUM*S Hydro'pvettmniic table, 247; ana^sisof a chaiyoeate well, 179 Acid^ chromict to obtain, 20; action of sulphuric acid on, 2^ ; fiuoric, esper. on, S08 ; muriaiic, do. S09; axymuriatic, do. 809; bvradcy do. 413 /tf^ndluve. Pap€^-son, 73,-466 Air-Uadderofjishes. On, 231,398 ^/«jn shales, in Yockshire, 2,'}6 Alumine fused, 46.'5 jdmmonium , On, 3»10 Analysis of black sand from river Dee, 98 ; of iserine, 103 ; of gray copper ore, !05; of crude platiua, 164; of chalybeate v/eJl at Middleton HslH, 179; of tobacco, 3 1 3 ; of belladon- sa, 314; of ancieat pi^-ments,3i5 ; of star-shot jelly 430 Anatomy, 59, 161 Animal secreHom. Home on, 108 Animal torpidity. On, 2,41 Apothecaries. Caution to, 235 Architecture in ivnod. On, 155 ^rms arid legs. Substitutes for, 236 Arseniatc of lead, native, described, 87 Arsenic in the Voltaic circuit, 411 Artificial stone. A singular, 153 AstioKomical instruments. On divid- ing, 168, 277 AstronoTnicalrefrcctioiis.Orooiribridge on, 303 Azi mil thai refrattion. On, 287 Bakerian lecture. Davy's, 401 Blanchard's rain table, 2C>tin.!j power of, 83 Farcy's ^ gcologkA remarks on the stratification of France and En* gland,.113,.i:5o; on musical inter- val, 173; on alum shales in York- shire, and orbicular sicnitc, 256; on collieries, 431 Fire escape, Davis's, 305 Fishes. On air-bladder of, 9.01 ; respi- ration of,Sr, 416 Thomsons analysis of black sand from the river Dec, 98; ditto ol iserine, 103; ditto of gray copper ore, 105 Trmher, growii'g. On vmIuc of, 428 Titanium found in the river Dee, 99 Torpidity of auimah. On, 241 Travels of discovery, 318 Tuning of musical mstruments, 448 Universities in Westphalia, 234 Uranium found in the river Dee, 103 Fanquelin on chromate of iron, &.c., 20; on air-bladder of fishes, 291 Fegetables. Exper. on, 313 Fulcanoes connected with each other, 235 TVaisteli on growing liriber, 428 ffalker, F , on adji sting powei O-f the eye, b3 ; new thermometer, 416 Ifernerian Society, 156, 'J?P, 305, 885, 463 IVestphalia. Universities in, 234/ Whales. Notice on, 23 1 ; Home on, 460 PJ'hinns. Properties of, 427 IVnyrtn dykes. On natural, 364 H'inter on manufacture of alum, 257 H'olJastor. s Croonian lecture, 439 ; goniometer, 94 ; paper on paJa- diun., 164; on identuy of colum- bium and tantalum, 201 Zircon fused, 468 Zoology J 393 '-i'^ ,%s, V, a END OF THE THIRTY-FIFTH VOLUME. l*nfUed by Richard Taylor and Co* Sh»€ Lane, Lcndon. 7. // ^ M , 3i Faiiyll.7. S8 Ihilo.Ma^.roljJI\'. n . / 59 T lowrif Sc. Th II. MTa^. Vol. -X^^ll'l. 11. <$/0^ e^^UyCZ-if ou/i/z^^rMT 4^M^l^^9^^e^:^^ '/n^e^?2^ ■1-^ SForUr fc. mioMaq. imYolIIIF. Eaiiy 11.8. lo-nry Sc. JV^4. EaMy.Flg. Ih£lcMa^.niVrolJIIK mi.Moff. Vol .xsxv; n .V. I/: ('ijvrn.ff'if'^' Diviiiinq l?i.';ti'iurfcnt . \ -1: FhU.Maa. Vol . SCQT: Fl TJl . W NuioJSa^.irmroLiixr. . Eaiiy Il.io. Iig.27. Icwry Sc A4 \3 AS A4 Cap^Taslejs J^ele^raph. nui.MoM. vci.iss^.n.iL. S-Jmrtm-.J^. Composition^ Jfc Decornposidon^ of For c^^. ^9 31AU Y PLATE If. ^^-^^^ '^^^^ J'^.Mof.Voi.jxxsr j'i.:xK Trofefscr Davfj .Uledro- chemical Apparatuj . rha.Ma^.Vol.73X/.n.:S3a, t Irofefjor Davys .Electro- chemical ApparatUif. U€. J.I^fta: . \..