wy * ENN SE hha al eceR =o of ng sx MO Te ME TR ny Sy PRR Soe THE ANNALS OF PHILOSOPHY. NEW SERIES. JULY TO DECEMBER, 1824. VOL. VIIL. AND TWENTY-FOURTH FROM THE COMMENCEMENT. ——EEE Ee aLanvon : Printed by C. Baldwin, New Briige-street ; FOR BALDWIN, CRADOCK, AND JOY, PATERNOSTER-ROW. TABLE OF CONTENTS. NUMBER I.—JULY. Page Biographical Account of Assessor John Goitlieb Gahn ..... MM che shire VTL Col. Beaufoy’s Astronomical Observations......-- eset wha oils aléje 'oie's eb. $4 Mr. Weaver on the Older Red Sandstone Formation. ......-s-0eeeeee epee Mr. South’s Corrections in Right Ascension of 37 Principal Stars. ..,... 23 M. Bonsdorff on the Chemical Composition of Red Silver Ore.....-+++- 29 Mr. Children on the Characters of some Mineral Substances before the Blowpipe. ...-++-0eeeeeneee gine big bUle cea mRVSse We BEw CEMA Ys Has hini> 36 MM. Ampere and Dulong on M. Rousseau’s New Method of measuring the Power of Bodies to conduct Electricity ......++++ssseerererseeees 39 M. Bequerel on the Electro-motive Actions produced by the Contact of Metals with Liquids. ...--.+-++++++ee+ee5: RIMMee bottle ale Riate Seer 42 M. Pfaff on a deoxidating Property of the Vapour of Water ...--------- 45 Mr. Woodward on the Transmission of Electricity through Tubes of Water 48 Mr. Smithson on Mr. Penn’s Theory concerning the Formation of the Kirkdale Cave .....-+++- eae ppeaatay saunas'ss segeels Rabesteetclel des Srna Analytical Account of the Rev. J. Topham’s Epitome of Chemistry..... 60 Proceedings of the Royal SOGGY sinigia araierecinesiasnis osnine sing sie ieioln ain 4 6s 63 Linnean Society .....+++- Seaplane eee aha te 63 —_—. Astronomical Society....se++eeerereeeeee Gale diwain 4 64 _——- Geological Saciety.,... 2:20 --srccenensnreenarts see 65 Nature of the free Acid ejected from the Human Stomach in Dyspepsia.. 68 Pyroxylic and Pyroacetic Spirits sseu dea yosinge oem abe ee 69 Argillaceous Iron Ore.....e+ee-eserrereretcesre seen caivabe tae WEONE 72 Aberthaw Limestone ....-seeeeeeereererree® Zeteyietaie'y sfaisels sine aMelstn® & ne Composition of Tourmaline......eeeeereeeees RRR ARPR ere en sodas hone Wistalits sees cua Tek wenaes canes Seta th ome eve decries Scare due sie eS Wate Minna 73 New Localities of American Minerals ....+++++seererertesrr ere ine wie On the Cause of the Rotatory Motion of Camphor in Water. «..-+++++- 75 Improvement in Clocks...+.-+++seseuerrerssestense et ets 76 Method of cleaning Gold Trinkets, and preserving engraved Copper-plates 76 Rees Goipntifie OOKG).ns.c sar csamerrrmcpeciss sss c cence sermses cones |” 77 RR tn Are en OOO bs 1k tad 78 Mr. Howard’s Meteorological J ournal,...- deo hoband ane Diese lareraisiaars 79 —= NUMBER 11.—AUGUST. Mr. Powell’s Remarks on Solar Light and Heat (continued). ..+r.eeee0e2 Sh Sir H. Davy on the Corrosion of Copper Sheeting by Sea Water. ....+-++ 04 Mr. Davies on the Application of Mathematics to Chemical Analysis.... 99 iv CONTENTS. Page M. Vauquelin’s Analysis of the Metal of the Statue found at Lillebonne.. 101 M. Lewenau on Selenium............00.cseeeee wfs\d’eiaiapoalesel aie ccoeaetaaiat ears 104 Mr. Gray on the Pulmonobranchous Mollusca ............seee cess seco LOK Mr. Chilton on an improved Rain Gauge.......... Palateposenicemibiats ou wee eRtOO Mr. Brooke on Baryto-Calcite ....... Me ee sescsene LOG Mr. Lewthwaite on the Transmission of Electricitythrough Tubes of Water 116 Dr. Prout on the Nature of the Acid and Saline Matters in Animals. .... 117 Mr. Gray on the Arrangement of Papilionida..........0.eeeeee eens eens 119 M. Berzelius on the Decomposition of Silica ........ Buco a Se oes 2 Ditto on the Mineral Waters of Carlsbad...... Helsiehs taxsresa tome Stee 2 0.128 Col. Beaufoy’s Astronomical Observations, ............. seve inlomtopneleteieia te 141 Mr. Children’s Reply to an erroneous Assertion..........ceceeecceeeece 141 Analytical Account of the Philosophical Transactions for 1824, PartI.... 144 Proceedings of the Astronomical Society ...........ceeceeeececeeeees ve 145 PEP ICIOMEAGEU EN ccies ss. cabin cas vulvle es oles SUL cE Seba safailcielele 146 Note on a Contradiction in Thomson’s System of Chemistry respecting Phosphuretted Hydrogen Gas ........ rere eur idee 147 Seeposed New Metal, Taschiains )... 22. veeens0edaceudoaeeus atelee tate 148 Chalybeate Preparations of the London Pharmacopoeia............ veeeses 149 eircom lack Pepper <>. ve .aicakies tticle camelese eee euch ileioe Sete oosisee AO Wee GF Nittons Oxide in Rudiometrys 5.26522. «dates ts doe uabaude scat 149 Sera taniZedyA MtliOMY, 00 o's Siaialaras dis ayaje: «| iejelaie Artic.xe III. Additional Remarks on the Older Red Sandstone Formation, or Group, of foreign Geologists, and the Carboniferous Series of the English. By Thomas Weaver, Esq. MRIA. MRDS. MWS. MGS. HMBI. (To the Editor of the Annals of Philosophy.) SIR, Tortworth, June 1, 1824, THE rapid progress that geology has made within some years: past, may be mainly attributed ; first, to the greater precisiom introduced into the researches of geologists, and the consequent greater accuracy of their descriptions; and secondly, to the comparisons which they have thus been enabled to draw betweeit classes and groups of formations, in different parts of the world. The ground-work has thus been laid for correct generalization. Most of the errors that have crept into geology have confessedly proceeded from a hasty desire of deducing general inferences from imperfect or merely local data, without taking that enlarged view of the subject, which, comprising all the modified details observable in different countries, secures alone a safe foundation fcr legitimate induction. The spirit of inquiry which has gove forth has led to discussion, and to that conflict of opinion in which zealous minds are prone to engage, when instigated by a sincere desire of eliciting the truth. Continental and English geologists thus mutually assist in elucidating the positions of each other. An instance of the kind may, perhaps, be found in the more exact determination of the relative position, characters, and organized remains of the muschel-kalk and quadersandstem of Germany, and other parts of the Continent, from which, so far as they have lately been investigated, there appears reason to 12 Mr. Weaver on the [JuLy, think that they constitute formations that are distinct from, and wholly wanting in, the geological series of England ; being in the order of succession interposed between the new red sand- stone and the lias limestone. For the clearer development of this position, so far as it has proceeded, we are in a great degree indebted to the active researches of Dr. Boué. Further researches, however, seem to be required before this question can be considered as satisfactorily and definitively settled, inas- much as the terms muschel-kalk and quadersandstein have both been avowedly very loosely applied in different parts of the Continent. But at present, I confess, I rather lean to the view of the subject entertained by M. von Humboldt and Dr. Boué. The preceding remarks may not appear wholly inapposite as a preliminary to what I am about to offer. In presenting in an English dress, and ina compendious form, a Selection from the Annales des Mines of a number of very valuable geological memoirs, Mr. De la Beche has performed a most acceptable service to the British public ; and the interest- ing geological map of France and of the adjoining countries, constructed by M. Omalius d’Halloy, and prefixed to the work, forms a very appropriate introduction, being also convenient as a subject for general reference. The book, I doubt not, will shortly be, as it justly deserves, in the hands of every British geologist. In this map, M. Omalius d’Halloy has distributed the whole of the formations, which constitute the crust of the globe, into six groups, which (taken in an ascending order) are as follows : 1. The primordial, comprising the primary and transition rocks. 2. The todte liegende or red sandstone group. 3. Comprising the zechstein (magnesian limestone), new red sandstone, muschel-kalk, quadersandstein, and oolite formation. 4, The iron and green sand, and chalk formation. 5. The formations posterior to the chalk, whose aqueous origin is not doubted. 6. Comprising all basaltic and trachytic rocks, and the pro- ducts of existing volcanos. In this order of arrangement, the todte liegende or red sand- stone group (occupying the position of the carboniferous series), is distinguished by Mr. De la Beche both on the map, and gene- rally throughout the work, as identical with a new red sandstone conglomerate. Yet the documents contained in this book alone not only afford a direct confutation of that statement, but it will be seen that in the construction of the text, Mr. De la Beche is, on this point, at variance with himself. It is important that this subject should be placed in its true light, for where authorities are balanced against each other, it becomes the more necessary that facts alone should be allowed to preponderate. 1824.] Older Red Sandstone Formation, &c. 13 It might indeed be supposed from the structure of the map that the group in question was intended by its author to repre- sent the carboniferous series ; and such will clearly be found to be the case, if we compare the corresponding coloured districts with the memoirs which tend to elucidate them, whether relat- ing to France, or to Germany. See the memoir of M. Omalius d’Halloy in illustration of his map; that of M. de Bonnard on the Geology of the Western Part of the Palatinate ; of M. von Hoff on the Thuringerwald ; of M. Beaunier on the Coal District of St. Etienne; of M. Le Chevalier du Bosc on the Coal Mines of the Basin of the Aveyron.* It will be sufficient for our purpose if we confine our attention to the memoir of M. de Bonnard on the Palatinate, selecting such parts as bear immediately on the question, and adding a few observations. P. 220, et seq. ‘“ The mountainous country on which I pro- pose to offer some geological remarks, is limited on the west and north-west by the course of the Brems and that of the Nahe on the south by the frontier of France ; on the east by the pro- longation of the Vosges chain to the foot of Mont Tonnerre; lastly, on the north-east by a curved line passing within the limits of the small towns of Gelheim, Alzey, Weellstein, and Creutznach.” ‘© On the left bank of the Nahe, and at a short distance from its bed, the schistose and compact quartzite formations com- mence, which form the mountains of the Hundsruck. On the right bank, and also at a short distance from the river, are situ- ated the coal measures and red sandstones of the Palatinate.” “ The Hundsruck, bounded by the Rhine, the Moselle, the Sarre, and the Nahe, forms part of the great schistose zone which is prolonged from the department of the Ardennes across the north of Germany, and which appears in a great measure composed of transition rocks. The red sandstones of the Pala- * In a former memoir on the North of France and the adjacent Parts of the Nether- lands (Journal des Mines, vol. xxiv), M.Omalius d’Halloy had erroneously applied the term rothe todte liegende to the gypseous and saliferous red sandstone which is found in Luxemburg, extending toward the Sarre, &c. But in the present map, and in the memoir by which it is accompanied, the saliferous or new red sandstone is placed in its correct position, while the term rothe todte liegende is employed in the appropriate German sense. There is, however, unfortunately, one great inconsistency in the map, upon which Mr. Dela Beche has justly remarked ; the carboniferous series of the north of France and of the Netherlands being, in conformity with the former view of M. O. d’Halloy (Journal des Mines, vol. xxiv), included in the transition series. It is also to be regretted that in the construction of the map, so important a group as the carboniferous series should in several cases have been wholly omitted, e. g. in Ger- many, in the tract extending from the Hartz to the banks of the Saale, that adjacent to the river Ruhr; in France, on the Loire between Angers and Nantes; at St. Litry, south-west of Bayeux, &c. , Their distinct introduction, wherever omitted, would have added to the value of the map, however small the scale might have been. The same indeed may be said of other groups, the scale of which, as omitted, must also necessarily have been small, 14 Mr. Weaver on the (Jury, tinate join on the E those which constitute the mountains of the whole northern part of the Vosges, the eastern slope of which is rapid, but which gradually declines to the W toward the coun- try which especially forms the subject of this notice. In this chain, the granite, long hid beneath the secondary rocks, ap- pears for the last time between Landau and Annweiler; it there forms near Alberschweiler an isolated mountain, in which the granite rock is seen to pass into porphyry. This mountain rises im the midst of the red sandstone that surrounds it, and which immediately rests upon it. Proceeding from this place toward the N to the foot of Mont Tonnerre, or toward the W to Sarre- bruck, red sandstones and quartzose conglomerates are only found, the whole of which is commonly known by the name of the red sandstone formation. They are covered, but only in a few points, in this direction, by horizontal shelly limestone (muschel-kalk), as at Bischmissheim, near Sarrebruck, or by limestone and marly clay, as in the environs of Deux Ponts, or by gypsum placed between the red sandstone and limestone, as at Omersheim, between Sarrebruck and Bliescastel. Not far from Sarguemine, on the right bank of the Sarre, is situated the small sa/ine of Relchingen, near the limit common to the red sandstone of the Palatinate, and the horizontal limestone of Lorraine. Still more west, the red sandstones envelope the southern part of the coal measures, are prolonged on the left bank of the Sarre, to and beyond the environs of Treves, and even penetrate on the right bank of this river, into the basin of the Brems and its confluents. They are also, in some points, covered with horizontal limestone, as at Nalbach (two leagues to the north of Sarre Louis), at Wahlen (between Mergiz and Wadern), &c. It is probable that this great mass of arenaceous rocks comprises the two formations of red sandstone, known in Germany by the names of rothe liegende and bunter-sandstein ;” meaning by the former, the ancient red sandstone, and by the latter, the new red, or variegated, or saliferous sandstone. That such is the interpretation to be given, the preceding description has partly tended to show, the old red and new red sandstones appearing in some places in direct contact with each other, and the new red sandstone partly overlying also the coal measures. But the relative position of the old red sandstone itself is com- pletely established by what follows. “ The coal measures form a zone which extends from SW to NE, 25 leagues in length, from the southern bank of the Sarre, a little below Sarrebruck, to beyond the Nahe in the environs of Sobernheim. The breadth of this zone of coal varies from four to seven leagues, according as it is more or less confined by the two chains between which it occurs. At about a third of its width, it is traversed by a band of the red sandstone formation, which constitutes some elevated summits, among others that of 1824.] Older Red Sandstone Formation, &c. 15 Hocherberg, near Waldmohr, and which divides the coal measures into two basins very different from each other.” “The southern coal basin, which sheds its waters into the Sarre, belongs: to the best characterized and richest coal measures. The general direction of its beds is SW and NE. On the N and E it would appear that this formation rests upon the red sandstone that surrounds it, and whose beds appear in some places on the banks of the Blies, near Neunkirchen, to the SE of Ottweiler, to dip beneath the coal measures. These are principally composed of alternating beds of argillaceous schist, slaty clay, and schistose sandstone, in which are observed nume- rous impressions of ferns and other plants common to this formation; of micaceous sandstone, or coal measure sandstone ; and of argillaceous and quartzose conglomerates. The formation contains good and numerous beds of coal worked in the envi- rons of Sarrebruck, and also beds and abundant masses of earthy carbonate of iron ore, in the nodules of which are sometimes remarked impressions of fish, particularly in the upper part of the coal measures, as in the environs of Lebach. This forma- tion also contains, but only between its upper strata, beds of compact limestone, grey or black, with a splintery fracture, and sometimes a schistose structure. On the SW the coal measures dip beneath the red sandstone, and are found by traversing the sandstone ;” being overlaid, as it would appear, by the new red or saliferous sandstone. “ The northern or Glane coal basin, which principally com- prises the banks of the Glane and its confluents, sheds its waters into the Nahe. No general direction can be observed in the stratification of its beds. The most southern coal beds, which are the best of the whole basin, incline to the N, and thus appear to rest on the band of red sandstone which separates them from the Sarre coal basin; but more on the N, the beds of coal worked often incline nearly parallel to the slope of the moun- tains that contain them, and the general disposition of the beds appears to be determined by the inequalities in the surface of an inferior rock situated at a slight depth. In this basin, beds of compact limestone, of a dark colour, occur very frequently in the midst of the schists and conglomerates, and even in many places appear (near Wolfstein, Rothseelberg, &c.) beneath the whole coal formation. They resemble those met with in the western part of the basin of the Sarre, placed there between the upper strata of the coal measures. But the principal mass of the Glane coal formation is often formed of argillaceous schists, with little or no impressions, and commonly alternating with schistose sandstone; but the variety of sandstone especially known by the name of the coal measure sandstone, is rather rare. A coal almost always dry and of bad quality often occurs in these rocks, forming in each mountain one, or at most two 16 Mr. Weaver on the [Jury, small beds of a few inches thick, in general situated near the surface. The coal is nearly always immediately covered, and also sometimes divided into two beds, by a limestone of a dull- yellow or blackish-brown, or presenting different mixtures of these two colours; so that in numerous mines the coal and limestone are worked together. Bituminous schists have also been observed in this formation, sometimes presenting impres- sions of fish penetrated with sulphuret of mercury. On its north-eastern limit the coal formation is covered in the enyirons of Alzey by horizontal limestone, which extends on the N and E to the banks of the Rhine ;” belonging, as it appears, to the formations posterior to the chalk. The preceding description by M. de Bonnard shows distinctly that in the tract which forms the subject of his memoir, we have the old red sandstone supporting two coal basins; in the north- ern of which, or that of the Glane, the carboniferous limestone not only appears in many places forming the immediate base of the coal formation, but is also interstratified with the coal mea~ sures, then commonly serving as the immediate roof of the coal. In the southern, or the Sarre coal basin, on the other hand, the carboniferous limestone occurs only between the upper strata of the coal measures. Now, this extensive carboniferous series is distinguished on M. Omalius d’Halloy’s map, and in his memoir as the todte liegende or ancient red sandstone group, including the coal measures, quite in conformity with the German sense of that term.* Indeed Mr.. De la Beche himself cannot avoid admitting (see the note, p. 223), that the old red sandstone sup- ports the coal measures of the Palatinate, thus invalidating his own position on the map and elsewhere, that the todte liegende, or rothe liegende, group denotes a new red sandstone conglome- rate. I think it needless to point out the repeated instances of this misconstruction of the term in other parts of the work, since what has been said admits of general application. I will, therefore, merely add, that in thus applying the term mew red sandstone conglomerate to the ancient red sandstone group of Werner (which includes the coal tracts), a violence is done to * See the construction of Freiesleben and of other German authors on this subject in the Annals of Philosophy for Aug. 1822, and May, 1823. See also the memoir of M. von Hoff in Mr. De la Beche’s Selection, p. 92, where, after describing the primary and transition rocks of the Thuringerwald, he proceeds thus :—‘* Those conglomerates, and micaceous or quartzosered sandstones (conglomerat, rothes und graves liegende), which together compose the formation named red sandstone, considered the most ancient of the secondary (floetz) formations, are the most extensively spread of all the rocks in the Thuringerwald ;” and p. 93, ‘* The coal formation of the Thuringerwald appears to belong, as a subordinate member, to the preceding.” If we combine also the valuable description given by M. de Bonnard, of the primary and transition tracts of the Hartz (p. 262—273 of the Selection), with Freiesleben’s account of the carboniferous series of the Hartz and the adjacent districts (as abstracted by me in the numbers of the Annals of Philosophy referred to above), the geological succession of the primary transition, and carboniferous series, will be found as obvious there as it is in M, von Hoft’s description of the Thuringerwald. 1824.]. Older Red Sandstone Formation, &c. 17 nature; while in the construction of the term rothe todte lie- gende, a double error is committed ; namely, a positive one, in applying it at all to the weissliegende (the calcareous, or new conglomerate, the lowest bed of the alpine or magnesian lime stone), an error sufficiently exposed by Freiesleben (vol. ii. p 239); and a negative one, in not applying it where alone it is strictly due; namely, to the red sandstone of the carboniferous series in general. It follows that the rothe todte liegende and porphyry of the Synoptical Table of Mr. De la Beche, are both superfluous and out of place, the todte liegende being, as already repeatedly observed, but an adjunctive designation of the red. sandstone of the carboniferous series, and porphyry occurring both among the coal measures and in the old red sandstone. It will be seen from the memoir of M. de Bonnard, that the carboniferous series of the Palatinate is also associated with trap rocks, maintaining in this respect likewise its analogy to the same series in other countries, The porphyry of Mont Tonnerre, &c. upon which this carbo- niferous series reposes on its eastern confines, appears to be of primary origin, containing veins of tin and other metals, Near Alberschweiler the porphyry passes into granite. French geologists have generally, until very lately, been in the habit ofreferring the carboniferous limestone and the old red sandstone to the transition series, and hence the former has been designated by them as transition limestone, and the latter as a ereywacke. The memoir of M. de Bonnard, and the map and memoir of M. Omalius d’Halloy, are indicative of more correct views. That their former persuasion may have been mainly influenced by the declaration of M. von Humboldt, respecting the English carboniferous limestone and old red sandstone, appears very probable.* The opinion of this distinguished naturalist respecting the Derbyshire limestone appears to have been adopted at a very early period, before its relations had been well ascertained; and with respect to the old red sandstone of Herefordshire, considered by him as transition or greywacke, it has evidently been confounded with the real transition red sandstone of that county. Indeed M. von Humboldt expressly states (p. 107 and 159 of the Essai), that the transition red sandstone of May Hill, the transition limestone of Longhope, the old red sandstone of Mitchel Dean, and the mountain lime- stone above it, are but repetitions or alternations of the same sandstone and limestone, all belonging to the transition series. This is a view, however, that will not receive support from any British geologist ; and that the two latter formations are essen- * See the Traité de Géognosie of M. d’Aubuisson, vol. ii. § 256; and the Essai sur le Gisement des Roches dans les deux Hémisphéres, of the Baron Alexander yon Hum- boldt, passim. New Series, vou, Vi1l c 18 Mr. Weaver on the (Jury, tially distinct from the two former, will, I trust, be made suffi- ciently evident in a paper of mine, which will appear in the con- cluding part of the first volume (New Series) of the Geological Transactions, now in course of publication. That the opinion of M. von Humboldt is altogether founded in misconception, particularly of the language of Prof. Buckland, must, I think, clearly appear from the following extracts :— “The old red sandstone of Herefordshire of Mr. Buckland, placed below the transition limestone (mountain limestone) of Derbyshire, is a transition sandstone, as has been very well indicated by this excellent geognost himself, in his Memoir on the Structure of the Alps” * (Annals of Philosophy, June, 1821); in which Prof. Buckland is made to say directly the reverse of what he intended to express; namely, that some foreign geolo- gists (especially of the French school) had erroneously denomi- nated as greywacke and transition limestone the old red sand- stone and carboniferous limestone of the English, which, on the contrary, are but the leading members of a totally different series ; namely, of the carboniferous, or, in other words, of the grande formation de grés rouge. Had M. von Humboldt himself had an opportunity of studying the relative position, characters, and freedom from fossil shells, of the old red sandstone of the British Isles, it is impossible that he could have avoided recognizing it as representing neither more nor less than the fundamental por- tion of the carboniferous tracts. His own language indeed may be adduced to prove this, being directly at issue with his former position: “ the red sandstone formation (meaning the carboni- ferous series, see Dr. Boué sur l’Ecosse, p. 376), which occupies the greater portion of Ireland, is common in the north of Ger. many, in the Black Forest, and in the Vosges.”+ Now these tracts all belong to precisely the same series as the correspond- ing tracts of Great Britain, and the old red sandstone of the one has just as much pretension to a transition character, or the name of greywacke, as the other. { may on this occasion advert to the extremely loose manner in which the term greywacke is employed by many German geologists, who are apt to include sandstone in this designation, when found in the transition period, and, as it appears (though unintentionally), when found out of it, e.g. in the old red sandstone. If we are to speak a language that shall always be intelligible, it becomes necessary that each term should retain its own peculiar signification. A * P. 157 ofthe Essai. ‘* Le vieux grés rouge (old red sandstone du Herefordshire) de M. Buckland, placé sous le calcaire de transition (mountain limestone) de Derby- shire, est un grés du terrain intermédiaire, comme cet excellent géognoste l’a trés-bien indiqué lui-meme dans son Memoire sur la Structure des Alpes.” + P. 212. ‘* La formation de grés rouge qui constitue la majeure partie de ]’Irlande, et qui est si commune dans l’Allemagne septentrionale, dans la Forét-noire et dans les Vosges, manque (de méme que la formation des porphyres) presque entierement dans las hautes Alpes de la Suisse.” 1824.] Older Red Sandstone Formation, &c. 19 second misconception of the language of Prof. Buckland is no less remarkable. “ The new red conglomerate of Exeter is the red sandstone of French mineralogists, or dodte legende of German mineralogists ; it is the first secondary (floetz) sandstone ; that is to say, the sandstone of the carboniferous tract, which is intimately con- nected with secondary porphyry, and hence the latter is called the porphyry of the red sandstone.” * But the position of Prof. Buckland is directly the contrary ; namely, that the red conglo- merate of Exeter does not at all belong to the carboniferous series, and is altogether of an origin posterior to it, and hence denominated new. With respect, however, to the real period, to which the red conglomerate in the vicinity of Exeter may more appropriately be referred, should its connexion there with the amygdaloidal trap be ascertained beyond dispuie, I confess I should rather side with the opinion of M. von Humboldt ; namely, that both belong to the carboniferous series. But should there be no such decided connexion, it may yet appear that the amygdaloid belongs to the transition tract of that coun- try, and the conglomerate itself to the gypseous or new red sand- stone, that is known to prevail in that part of the kingdom. _ I have more than once found it necessary to show, that English geologists have misunderstood the true import of the older red sandstune group, or rothe todte liegende, of German authors; and additional evidence of this fact is to be found in the construction put upon these terms throughout the very inte- resting and important work of M. von Humboldt. See in parti- cular the first division of the Terrains Secondaires, p. 205, et seq. from which, in addition to preceding extracts, I select only the following :—“ It is difficult to assign a general type for the order of the different beds which constitute the great formation of coal, red sandstone, and porphyry (with interposed beds of amygdaloid, greenstone, and limestone). The coal appears most commonly below the red sandstone, and sometimes it is evidently placed either in this rock or in the porphyry.” This last sentence appears more particularly referable to certain parts of Germany, where only a portion of the carboniferous series is displayed, e. g. in Thuringia ; but from such merely local facts no general inference can be drawn. “ Sometimes the great depusit of coal is not covered by-porphyry and red sandstone ; sometimes it occupies great basins surrounded by hills of red * P. 157. “ Le nouveau conglomérat rouge (new red conglomerate d’Exeter) est le grés rouge des minéralogistes francois, ou dod/e liegende des minéralogistes Allemands ; e’est le premier grés du terrain secondaire, c’est a dire le grés du terrain houiller, qui est intirmement lié au porphyre secondaire, appelé pour cela porphyre du grés rouge.” See also p. 205. + P. 209, “Tl est difficile d’assigner un type général a l’ordre des differentes assises oy constituent la grande formation, § 26, La houille paroit le plus souvent au-dessous u grés rouge ; quelquefois elle est placée évidemment ou dans cette roche ou dans le porphyre.” c2 20 Mr. Weaver on the [Juny, sandstone and porphyry, and presents in its roof only alternating beds of slate-clay and carbonated shale, the former containing numerous impressions of ferns. Thin beds of coaly shale, beds of quartzy sandstone passing into granular quartz, of large- grained conglomerate (coal measure conglomerate), and of fetid limestone also, are met with in the midst of the slate-clay before the coal is attained.””* On the other hand, it is equally certain, that Continental geologists have misconceived, in some instances, the purport of the language employed by English writers. Hence has arisen a double confusion ; when, after all, if the language of each had been correctly apprehended, there would have been as little discrepancy in description as there is in the appearances of nature, since the facts themselves are perfectly reconcileable to each other. To attempt to clear away difficulties and dispel obscurity is both an irksome and ungrateful task; and the love of truth alone has impelled me to it. If it shall be found that I have in any degree succeeded in throwing a clearer light upon a com- plicated subject, my purpose will be fully answered. The researches of M. Constant Prevost, an eminent French geologist, and FMGS. who is at present engaged in examining the geolo- gical relations of this country with a critical eye, will, I have not a doubt, conduce to the same desirable end. I have upon former occasions remarked, that all the esta- blished relations of the old red sandstone, carboniferous lime- stone, and coal formation, to each other, as founded upon the researches and descriptions of naturalists in different countries, prove that they constitute one group of the same era; yet vary- ing much in the modes of their association, as being found in one tract distinct from, and in another more or less interstratified with each other. The following view, which may be of some value in reference to practical and economical purposes, will be found to embrace a summary of those relations. 1. Old red sandstone, carboniferous limestone, and the coal formation, in separate and distinct succession, not interstratified upon their several confines ; e. g. the general case in Ireland. This may be considered as the distinct type of the series. N.B. The bed of sandstone and conglomerate, found in some . 4 fo) tracts interposed between the limestone and the coal measures, * P, 207. “* Souvent le grand depét de houille n’est pas recouvert de porphyre et de grés rouge. Souvyent il est placé dans les basins entourés de collines de grés rouge et de porphyre, et n’offre dans son toit que des couches alternantes d’argile schisteuse (schie- ferthon), tantot gris-bleuatre, tendres et remplies d’empreintes de fougéres, tantét com- pactes, carburées (brandschiefer) et pyriteuses, Des minces strates de grés charbonneux (kohlenschiefer), de grés quartzeux passant au quartz grenu, de conglomérat 4 gros fragmens (steinkohlen-conglomerat), et de calcaire fétide, se rencontrent au milieu du schieferthon avant qu’on atteigne la houille.” 1824,] Older Red Sandstone Formation, 8c. 21 and designated in England as the millstone-grit, is wanting in Ireland. N. B. This peculiar application of the term mil/stone-grit is bad as a distinction, since a similar compound is generally found in beds in the fundamental or old red sandstone, and in some countries also frequently interstratified with the coal measures, e. g. in Germany. 2. A base of old red sandstone, supporting limestone, which alternates with sandstone, a considerable bed of the latter, with conglomerate, forming the immediate foundation of the coal measures, which are distinct; e. g. the Gloucestershire south coal basin. N. B. The more common coal bearing measures are in this basin separated into a lower and an upper series by an interven- ing thick bed of reddish sandstone, locally known by the name of Pennant-stone. N.B. A similar occurrence, on a larger or smaller scale, is not uncommon in Germany, and when the red sandstone thus occurs immediately under the magnesian or alpine limestone (with its calcareous or new conglomerate, the werssliegende), it is known by the name of todte liegende, or rothe liegende, or rothe todte liegende, in the same manner as these terms are applied to the fundamental red sandstone when also directly covered by the calcareous conglomerate and magnesian limestone. But the term rothe todte liegende has also been often erroneously applied, as already noticed above, to the calcareous or new con-~ glomerate itself.* 3. A base of old red sandstone, supporting and alternating with some beds of limestone, succeeded by a coal formation, composed, in an ascending order, as follows : a. Of coal measures alternating with limestone, and with red- dish sandstone, the coal being inconsiderable in quantity. b. Productive coal measures, alternating with numerous beds of limestone. * M. von Humboldt correctly distinguishes the weissliegende, as the bed which intervenes between the coal formation and the zechstein, or magnesian limestone (see p. 224 of the Essai). It thus corresponds with the calcareo-magnesian, or new conglome~ rate of England, appearing as its only representative. On the other hand, however, both M. von Humboldt and Dr. Boué speak of the zechstein, or magnesian limestone, as occurring sometimes interstratified with the coal measures. his is a position utterly at variance with all experience in the British Isles, and seems quite untenable, if we consider that the calcareous conglomerate, or weisslie- gende, is commonly found in an unconformable position, overlying both the coal measures, and the carboniferous series in general; being the first member of a new series; namely, of the gypsco-saliferous. In the instance quoted, e. g. in Lower Silesia (p. 34, 213, &c.) it is true that, in the year 1802, M. von Buch considered the limestone in question as zechstein, and as such as of an origin posterior to, and placed above the coal formation ; but M. von Raumer in 1819 clearly showed that this lime- stone was repeatedly interstratified with the coal measures, and therefore not zechstein ; and certainly no two series can be generally more distinct from each other than the car- boniferous and the gypseo-saliferous series. Other instances cited, probably rest upon no securer foundation than misconception, or fallacious description, 22 On the Older Red Sandstone Formation, &c. [Jury, c. Coal measures, abundant in coal, but free from limestone. E. g. in the Scotch great coal tract. 4. A base of old red sandstone, supporting limestone, which not only constitutes the -foundation of the coal formation, but alternates with the coal measures, often forming the immediate roof of the coal seams: e. g. the Glane coal basin, described above. 5. A. base of the same old red sandstone, supporting a coal formation, composed, in an ascending order: a. Of productive coal measures alternating with beds of sand- stone conglomerate. b. Of coal measures alternating with limestone. E. ¢. the Sarre coal basin, described above. N. B. The coal measures of this basin are overlaid on the W and § by the new red or saliferous sandstone; so that if the series of coal measures be continued in that direction, and toward which they dip, they are withdrawn from observation. Could we follow them, it appears not improbable that the suc- ceeding coal measures might be found free from limestone. But be this as it may, it is remarkable that in this coal field, the greatest number of the coal seams are found above the funda- mental red sandstone, and beneath the limestone bearing strata, being thus directly connected with the former. The carboniferous series of all countries, whose members are complete, will probably be found referable to one or other of the preceding modes of association. In addition to those which relate to the alternation of the carboniferous limestone with the coal measures, may be cited analogous appearances in Silesia and Hungary, as described by MM. von Raumer and Beudant. The New Continent also presents, it seems, similar relations ; e.g. in the coal formation of the Ohio, in the great basin of the Mississippi, where coal seams are represented as occurring both above and beneath the limestone.* The preceding examples refer to tracts where all the members of the series are present; but in some districts, the carbonife- rous limestone is found altogether wanting, the coal formation being directly connected with the old red sandstone; while in others, both the limestone and old red sandstone being absent, a simple coal formation is only met with. But in all cases, the series, whether complete or incomplete, reposes either on tran- sition, or on primary tracts, or on both of these conjointly. The occasional association of trappean, amygdaloidal, and porphyritic rocks, both separately with the individual members, and conjointly with the series in general, is now too well known to require more than the simple notice of the fact. * See the Account of an Expedition from Pittsburg to the Rocky Mountains in ' ts : and 1820, by Edwin James, Botanist and Geologist to the Expedition. London, 1824.] Corrections in Right Ascension. 23 Art. IV.—Corrections in Right Ascension of 37 Stars of the Green wich Catalogue. By James South, FRS. y Pegasi| Polaris | « Arietis|“ «Ceti [Aldebaran] Capella | Rigel @ Tauri | Orionis Mean AR? h. m. s. [b. m h h 1824. -S. |l.m. s. |hem. s. |hem. s. |h. m. s. |h. m. Ss. |h.m.s. |b. m. s. 0 4 11°17) 0 58 2°66 |) 57 16°42/2 53 5°44 |4 25 50°01/5 3 42°21] 5 6 5°11] 15 15 1052/5 45 38:93 July 1)4+ 2°79 + 3:27"| + 2°33") + 192/14 1-76") + 2:00") + 1:24) + 1°81”) 4 1-47” —_ aby 2 82 4:07 36 95 18 03 26 83 Ag 3 85 4-86 40 97 8l 06 28 85 50 4 88. 5°66 AZ 2:00 83 09 30 88 52 5 91 6-46 46 03 85 12 32 90 53 6 95 7°26 49 06 88 14 34 92 55 7 98 8:05 53 09 90 17 36 94 57 8} 3:02 8:85 56 12 93 20 38 97 59 9 05 9°65 59 15 95 23 40 99 61 10 08 10-44 62 18 98 26 A2 2°02 63 1] ul 11-22 66 21 2-01 29 44 04 65 12 14| 12°01 69 24 03 32 46 OT 67 13 17 12-79 72 27 06 36 A9 09 69 14 20} 13°58 15 30 09 39 51 12 71 15 23 14-39 79 22 12 42 53 15 13 16 26} 15:20 82 35 15 A5 55 17 15 17 29 16:01 86 38 18 48 57 20 V7 18 32 | 16°82 89 Al 20 5] 60 22 19 35 | 17°63 93 44 23 55 62 25 81 20 38 | 1840 96 Al 26 58 64 28 83 21 4l 19°17 99 50 29 62 67 3l 85 22 43 | 19°94 3°03 54 32 65 69 33 ST 23 A6 | 20-72 06 57 35 69 ve 36 90 24 49} 21:49 09 60 38 72 74 39 92 25 52 | . 22°25 12 63 4l 16 76 42 95 26 55 | 23-01 15 66 44 19 719 45 97 27 57 | 23°77 18 70 AT 82 81 47 99 28 60 | 24:54 22 73 50 86 84 50 2°02 29 63 | 25°30 25 76 52 90 86 53 04 30 65 | 26:03 28 719 55 94 89 56 OT 31 68 | 26°76 32 82 58 98 91 59 09 Aug. | 70 | 27:48 35 85 61 301 94 62 11 2 73 | 28-21 38 88 64 05 97 65 14 3 75 | 28°94 Al 91 67 09 99 68 16 4 78 | 29°66 45 94 710 13 2:02 ue! 19 5 80 | 30°39 A8 97 73 16 05 TA 21 6 83 | 31-11 51 3°00 76 20 08 vic 24 if 85 | 31°84 54 03 19 24 10 80 26 8 88 | 32°56 58 06 82 28 13 84 29 9 90 | 33:23 61 3) 85 32 16 87 32 10 92 | 33:90 64 12 88 36 19 90 35 11 95 | 34°57 67 15 91 40 21 94 37 97 | 35:25 70 18 94 44 24 97 40 99 | 35:92 13 21 9% 49 27 3:00 43 4-01 | 36°58 16 24 3-01 53 30 03 A6 15 03 | 37-24 12 27 04 57 33 06 49 16 05 | 37:90 82 30 OT 61 35 09 51 17 08 | 38°56 85 33 10 66 38 13 54 18 10 | 39-21 88 35 13 710 Al 16 57 19 12 | 39-81 91 38 16 74 44 19 60 20 14 | 40-41 94 Al 19 18 AT 23 62 21 16 | 41-00 96 43 22 82 49 26 65 22 18 | 41-60 99 46 25 86 52 29 68 23 20 | 42:20 4:02 49 28 90 55 32 71 24 22 | 42-77 05 52 31 95 58 35 TA 25 23 | 43°34 08 55 34 99 61 38 16 26 25 | 43-90 11 58 31 4-03 63 42 19 27 27 | 44-47 13 61 40 OT 66 45 81 28 29 | 45-04 16 63 A8 11 69 49 84 29 30 | 45°54 18 66 46 15 12 52 87 32 | 46:05 46°55 24 Corrections in Right Ascension of - ‘[Juxy, Sirius Castor | Procyon | Pollux | Hydre| Regulus | @ Leonis [8 Virginis |SpicaVirg+ MeanAR)|h. m. s. |h.m.s. |h. m. s. |h.m. s. |h.m. s. /h.m. s. Jh,m. s. {h.m. s. them, s. } 6 87 23°49|7 23 21°46] 7 30 5°32|7 34 32°18]9 18 56°44/9 58 59°57]11 40 4°73/11 4) 31°86}13 15 56°07 24. July 1} + 0:89") + 1-78”) + VAL’) 4 1-74) 4 151 + 1°93 4 2:35) + 2°37 + 291! a} 90 719 42 15 51 93 34 36 90 3} 9 80 43 76 51 92 33 35 89 4| 93 81 43 76 51 92 32 35 88 5] 94 82 A4 11 50 92 31 33 87 6| 95 82 45 78 50 91 30 33 86 "| 96 83 45 78 50 91 30 32 85 8} 98 84 46 79 50 91 29 32 84 9} 99 85 At 80 49 90 28 31 83 10| 1-00 86 48 81 49 90 27 30 82 11] 02 88 49 82 A9 89 26 29 81 12] 03 89 50 83 49 89 25 29 80 13, 4 91 52 85 49 89 24 28 19 14] 06 93 53 86 49 89 23 27 "9 15] O07 94 54 87 49 88 23 26 18 16| 09 96 55 88 49 88 22 26 17 1i| 10 91 56 89 49 88 21 25 16 is} 12 99 58 91 49 88 20 24 15 19} ~=-13 | 2:00 59 92 49 87 19 23 74 20) 15 02 60 94 49 87 18 22 13 2i| 17 03 62 95 50 87 17 29 72 22) 18 05 63 97 50 81 17 21 7 23) 20 07 64 98 51 87 16 20 70 24, 99 09 65 | 2-00 51 87 15 19 69 25| 24 10 66 ol 51 81 14 19 68 26| 26 12 68 03 52 88 13 18 66 271| eT 14 69 05 52 88 13 17 65 98] 29 15 71 06 52 88 12 17 64 29} 3 17 72 08 53 88 1 16 63 30| 33 19 14 10 54 88 10 16 62 31| 35 al 15 12 54 89 10 15 61 Aug. 1| 37 23 17 14 55 89 09 15 60 a} 39 25 19 15 56 89 09 14 59 a 41 97 81 17 BT 89 08 14 58 Al 43 29 82 19 51 89 07 13 57 5} 45 31 84 21 58 90 06 13 56 6} 47 33 86 23 59 90 05 12 55 "| 50 35 87 25 59 90 05 12 53 8} 52 38 89 21 60 91 04 11 52 9} 54 40 91 29 61 91 04 11 51 10| 56 43 93 31 62 92 03 10 50 11] 58 45 95 34 63 92 03 10 49 1Q) «GL |* AT 91 36 64 93 03 10 48 13) 63 50 99 38 64 93 02 10 AT 14, 65 53 | 202 40 65 94 02 09 46 15] 67 55 04 42 66 4 02 09 45 16, 70 51 06 45 61 95 ol 09 44 7} 72 60 08 AT 68 95 ol 08 43 18) 74 62 10 49 69 96 00 08 42 19] 76 65 12 Bl 10 97 00 07 41 20) 78|° 67 14 54 71 98 00 06 40 21; Si 10 16 56 73 99 00 05 39 22} 83 72 18 58 74 | 92-00 00 05 38 23; 85 15 20 61 15 ol 00 04 37 24] 87 77 |! 99 63 16 02 00 03 3T 25] 89 80 24 65 18 03 00 02 36 26, 91 83 26 68 719 04 00 ol 35 2i| 94 85 28 70 80 05 00 | 1-98 34 28] 96 88 31 13 8! 06 00 97 33 29} 99 91 33 "6 82 07 00 98 32 30] 2-02 95 36 78 84 08 00 99 32 31| © 05 98 38 81 85 10 00} 201 31 1824.] Thirty-Seven Principal Stars. 25 Arcturus |2 a Libre|aCor.Bor.| Serpent.| Antares |aHerculis|2Ophiuchi] a Lyre |y Aquile h. Mean AR m. s. |h. m. s. |h.m. s. }h. m. s. |h. m. s. |h. m. s. jh. m. s. [he m. s. [hom s. 14 7 38°33]14 41 9°63)15 27 14:45) 15 35 36°47]/16 1827°91|17 6 37°72|17 26 46:24) 18 30 58-99) 19 37 53°68 1824. July + 2°97 4+ 3°52"! + 3°23”) + 3-484 4-44") 4 3-62!" + 3°68") + 3-49" 4 3°74! 96 51 22 AT 44 62 68 AQ 75 95 50 21 AT 44 62 68 43 16 50 21 46 43 62 68 A3 18 93 A9 20 46 43 62 69 AA 19 92 48 19 AS 43 62 69 AA 80 91 AT 18 A5 43 62 69 Ad 81 89 AT 18 AA A3 62 70 45 83 88 46 17 44 AZ 62 710 46 84 OMADHD Sr 09 We | =) r=4 10 87 45 16 43 4Q 62 10 A6 85 il 86 AA 15 49 Al 61 10 46 86 12 84 43 14 AQ Al 61 70 A6 87 13 83 AQ 12 Al AO 61 50 46 88 14 82 Al 11 40 40 61 69 46 89 15 81 AO 10 39 39 60 69 46 90 16 80 39 09 38 39 60 69 45 91 17 79 38 08 37 38 60 69 45 92 18 tft) 38 06 37 38 59 68 45 93 19 76 37 05 36 37 59 68 45 94 20 15 36 04 35 36 58 68 A5 95 21 73 35 02 34 35 57 67 44 95 22 72 34 ol 33 35 57 67 44 96 23 71 33 | 2:99 32 34 56 66 43 96 24 69 32 98 31 33 55 66 43 97 25 68 31 96 30 32 54 65 AQ 97 26 66 30 95 29 32 54 65 42 98 27 65 29 93 28 31 53 64 4l 99 28 63 28 92 27 30 52 64 4l 99 29 62 26 90 25 29 51 63 40 | 4:00 30 61 25 89 24 28 50 62 39 00 31 59 24 87 23 27 A9 61 38 00 Avg. | 58 22 86 21 26 48 60 31 00 2 57 21 84 20 24 AT 59 36 OL 3 55 20 83 19 23 46 58 35 Ol A 54 19 81 18 22 Ad 57 34 OL 5 52 18 80 17 21 44 56 33 Ol 6 51 17 78 16 20 43 55 32 02 7 A9 15 17 14 18 42 54 31 02 8 48 14 15 13 17 Al 53 30 02 9 46 13 73 12 16 40 52 29 02 10 A5 11 71 10 14 38 51 27 Ol 13 40 08 65 06 10 34 48 23 Ol 14 39 07 64 05 09 33 AT 22 00 15 37 06 62 03 07 31 A6 20 00 16 36 04 60 02 06 30 45 19 3:99 17 34 03 58 ol 04 28 44 17 98 18 32 | 56 | 9-99 03 27 42 16 98 19 31 00 54 98 02 26 41 14 97 20 29 2-98 52 96 00 24 39 12 96 21 28 97 50 95 | 3-99 23 38 if 96 22 27 96 48 93 97 21 36 09 95 23 25 95 46 92 96 20 35 07 95 24 24 94 44 90 94 18 33 05 94 25 22 92 42 89 93 17 32 04 94 26 21 91 40 87 91 15 30 02 93 27 19 90 39 86 90 14 29 00 93 28 18 88 37 84 88 12 27 | 2-98 93 29 17 87 35 83 86 10 25 96 92 26 Corrections in Right Ascension of [Juty, -m. & 2156 44°67 + 2:81" 77"| 4 3°78"| 4 4912" 4 3-30” + 3-49” July 1/4 3° + 361" |+ 3°10” 18 80 51 64 13 84 80 81 54 67 16 88 81 83 56 71 19 91 82 84 59 74 22 95 84 86 61 77 24 98 85 87 64 80 27 | 3-02 86 89 66 84 30 05 88 90 69 87 33 09 89 YI 71 90 36 12 90 92 73 94 38 15 91 93 15 97 41 18 92 94 18 4:00 44 21 93 95 80 03 AT 24 95 97 82 07 50 28 96 98 84 10 52 31 97 99 87 13 55 34 98 | 4:00 89 16 57 37 99 01 91 20 60 40 400 02 93 22 62 43 00 03 95 24 64 AG 01 03 96 26 66 49 02 04 98 28 69 52 03 05 4-00 30 71 55 03 06 02 32 13 58 04 07 04 34 15 60 05 07 05 36 78 63 05 08 07 37 80 66 06 09 09 39 82 69 06 09 10 Al 84 72 06 09 12 43 86 74 07 10 15 Al 90 80 OT 10 16 49 92 83 07 10 18 52 94 85 07 10 19 54 96 88 08 11 21 56 98 91 08 11 22 58 | 4:00 94 08 11 Q4 60 02 96 0s 11 25 62 04 98 07 ll 26 63 05 | 400 07 11 28 65 07 03 07 10 29 67 09 05 07 10 30 69 11 07 06 10 31 70 13 09 06 10 32 72 15 12 06 09 33 74 16 14 05 09 34 15 18 16 05 09 35 17 19 18 04 08 36 18 20 20 04 08 36 79 21 22 21 03 OT 37 81 22 24 03 07 37 82 23 26 02 06 38 83 24 28 02 05 39 84 26 30 ol 05 39 85 21 32 00 04 40 87 28 34 27| 3:99 04 40 88 29 36 28 99 03 Al 89 30 38 29 98 02 Al 90 31 40 30 97 01 Al 90 32 Al 31 96 00 42 91 32 43 1824.] y Pegasi Mom t h.m. s. |h 1824. 0 41117 Sept. 1) 4 4-35” 2} 36 Thirty-Seven Principal Stars. 2 Polaris a Arielis a Ceti |Aldebaran} Capella | Rigel @Tauri jx Orionis m -m, s. |h.m.s. |h. m.s. |h. m. s. |h, m.s. |he m.s, |h. m.‘s. [ho m. s. 0 58 2°66 |1 57 16-422 53 5°44/4 25 50°01/5 3 42°215 6 5°11)5 15 10°5215 45 38:93 | +47:06"| + 4:26" + 3°73") + 3:55’ 4 4:29" + 2:80”| + 3-63" 14 2-95” 47°56 29 716 59 48°03 31 19 62 48°50 34 82 65 48°96 36 85 69 49°43 39 88 12 49-90 4\ 90 15 50°30 43 92 18 50-70 46 94 81 51°10 48 96 84 51°50 50 98 87 5191 52 | 4:00 90 52-26 55 02 93 52°61 5T 04 96 52°96 59 06 99 53°32 62 09} 4:02 53°67 64 11 05 53°96 66 14 08 54-25 68 16 11 54°53 70 19 14 54-82 72 21 17 55°11 TA 24 20 55°35 TT 26 23 55+59 19 29 26 55°83 81 31 28 56:08 83 34 31 56°32 85 36 34 56°49 86 38 37 56°66 88 40 39 56°82 89 42 A2 33 38 42 46 51 55 59 63 67 10 74 18 83 86 89 92 95 98 3-01 04 06 09 12 15 18 20. 23 26 29 32 34 37 40 43 A6 48 51 54 57 59 62 98 3°01 04 OT 10 13 16 19 22 25 28 30 33 36 39 42 45 48 Castor | Procyon Pollux | a Hydre h. m. s. h. m. s. |h. m. s. jh. m. s. | 7 23 21467 30 5°32\7 34 32:18/9 18 56°44) S 38 A 39 Pi 40 6 42 7 43 8 44 9 45 10 46 1) Al 12 48 13 49 14 50 15 51 16 52 17 53 18 54 19 55 20 56 21 56 22 57 23 58 24 59 25 60 26 60 27 61 28 61 29 62 30 62 | Sirius Mean AR) jh. m. s. 1824, § |6 37 23-49 Sept. 1|+ 2-07 2 10 3 13 4 16 5 19 6 22 7 25 8 28 9 30 10 33 11 36 12 39 13 42 14 44 15 47 16 50 17 52 18 55 19 58 20 61 21 64 22 67 23 10 24 13 25 15 26 18 27 81 28 84 29 87 30 90 + 3°01"| + 2°41”) 4 2°84") 4 1°87” 04 43 87 88 OT 46 89 90 10 48 92 91 13 51 95 93 16 53 97 94 18 55 *300 96 21 58 03 98 24 60 06 99 27 63 09 2°01 30 65 12 03 33 68 15 05 36 10 18 06 39 73 21 08 42 76 24 10 46 18 27 11 AQ 81 30 413 52 84 33 15 69 9T 48 26 12 3:00 52 28 15 02 55 30 18 05 58 33 82 08 61 35 Regulus | 6 Leonis é@ Virginis |SpicaVirg. h. m. s. |h. m. s. |h. m. s. |h, m. s. 9 58 59°57|11 40 4°73/11 41 31°86/13 15 56°07 + 2°11"| + 2:00") + 2°02’) + 2-31 12 30 30 29 Rd ° a ° ° . 28 Cofrections in Right Ascension. [Jury, Arcturus |2 a Libre |« Cor.Bor./ Serpent.| Antares |aHerculis|aOphiuchi] a Lyre | y Aquile Mean pet h. s. [ho m. s. jh. m.s. {b. m. s. |h.m. s. /h,m. s, |h. m. s. {/h. m, 5, |h. m, 5s. 1824. \4 7 38:33/14 41 9°63/15 2714-45115 35 36° the 18 27:91/17 6 37°72|17 26 46°24/18 30 58-99) 19 37 53°68 Sept. 1) + 2°13”| + 2-83’) + 2:30” | + 2-78" | + 3°82} + 3:05" | + 3-21 |+ 2°89") + 988” 2 12 82 28 hel 80 03 19 87 3 1] 81 26 15 19 02 18 85 a 4 10 80 24 TA 7 00 16 83 85 5 08 18 23 72 75 2:98 14 81 84 6 07 17 21 71 TA 97 .oA3 18 82 7 06 76 19 69 72 95 >a 76 81 8 05 15 17 68 70 93 09 A 80 9 04 14 15 66 69 91 07 71 18 10 03 13 14 65 67 90 06 69 V7 11 02 72 12 63 66 88 04 67 16 12 ol 71 10 62 64 86 02 65 15 13) 1:99 69 08 60 63 84 00 63 13 14 98 68 06 59 61 82 298 60 12 15 97 67 05 57 59 81 97 58 vel 16 96 66 03 56 58 19 95 55 10 17 95 65 ol 54 56 iC 93 53 68 18 94 64 1-99 53 54 15 91 51 67 19 93 63 98 52 53 74 89 48 65 20 93 63 96 50 51 72 88 46 64 21 92 62 95 49 50 70 86 44 62 22 91 61 93 A8 48 68 84 41 61 23 90 60 91 AT AT 67 82 39 59 24 89 59 90 46 45 65 81 36 58 25 89 59 88 44 AA 63 719 34 56 26 88 58 87 43 A2 62 q7 3] 55 27 87 57 85 42 40 60 15 29 53 28 87 56 84 4l 39 58 13 27 51 29 86 56 82 40 37 57 72 24 50 30 86 55 81 39 36 55 10 22 48 a Aquilée } @ Aquile |2 aCapricor} a Cygni | Aquarii |Fomalhaut | « Pegasi iti + Mean AR) {h. m. s. |h. m. s. |b. m._s. |h. m. s. |h. m. 8. h. m. s. {h. 1824. § {19 42 1188/19 46 40°23 20 8 17:02/20 35 26-21/21 56 44°67/22 47 5 4:34/29 56 0° 7 2 39 8 67 Sept. 1)+ 3:95”) + 3-99""| + 4:49” |4+ 3°59”)+ 4-42” +491" |+ 4:33") + a-44" 2 94 98 48 58 AQ 92 34 46 3 93 97 48 57 42 93 35 AT A 92 96 AT 56 42 94 36 49 5 91 96 46 55 43 94 37 51 6 90 95 A6 53 A3 95 37 53 7 89 94 45 52 43 96 38 54 8 88 93 A4 50 43 96 38 55 9 86 9 43 A9 A3 97 39 56 10 85 90 42 AT 42 97 39 57 1] 84 89 Al 45 42 97 39 58 12 83 88 40 43 42 98 AO 59 13 81 86 39 42 42 98 40 60 14 80 85 38 40 42 98 40 61 15 79 84 37 38 Al 98 40 62 16 TT 82 36 37 Al 99 Al 63 17 16 sl 35 35 Al 99 Al 64 18 75 80 34 33 40 99 Al 65 19 73 18 33 31 40 99 Al 65 20 72 77 31 29 39 98 Al 66 21 ve 76 30 27 39 98 Al 67 22 69 44 29 25 38 98 Al 68 23 68 Wee 28 23 38 98 Al 68 24 66 71 27 21 37 98 Al 69 25 65 70 25 19 36 7 Al 70 26 63 68 24 17 36 97 Al 70 27 62 67 23 15 35 97 Al 71 28 60 65 21 13 34 oF Al (lt 59 64 33 _ 5T . 62 . 33.. 1824.] Onthe Chemical Composition of Red Silver Ore. 29 ARTICLE V. New Investigation of the Chemical Composition of Red Silver Ore.* By P. A. v. Bonsdorff. In consequence of the analysis of red silver ore by Klaproth and Vauquelin, this mineral has been considered as a compound of sulphuret of silver, sulphuret of antimony, and oxide of anti- mony. Klaproth’s last analysis of this mineral from Andreas- berg (Beitrage, v. 197) makes its constituents as follows : CN ce etatba bin sn s'awein sies erta hs Te Py PAIMATLLODY ao are: 4 aa Qn ah Pod 4B cigla.e'¥ie 44) ae, SUT ee i eines ie ae ay fy | SPCR levy; sininieig & «\adie ayainin ee * oe 100 But both in this analysis, and in the others made upon the same mineral, although the quantities of constituents obtained were unequal, no positive proof was obtained of the presence of oxygen, or of oxide of antimony. It was merely concluded that the great loss sustained during the analysis was owing to the presence of oxygen. In this way Vauquelin reckoned the whole loss, which was about 12 per cent. as oxygen. And Klaproth, for the same reason, reckoned 4 or 5 per cent. of oxygen in his different analyses. But as the result of these analyses do not agree with any atomic proportions; and as both the existence and amount of the oxygen still depend upon imperfect and uncertain evidence, I was in hopes that a new analysis might not be destitute of all interest. In Prof. Berzelius’s laboratory, I lately enjoyed a fortunate opportunity of undertaking the ana- lysis of the dark red silver ore from Andreasberg ; and I propose in this paper to give an account of the analytical experiments which I undertook, and of the result of them. The first attempt was to extract the supposed oxide of anti- mony from the mineral by means of dilute muriatic acid. Picked specimens of the ore were reduced to the finest possible powder,+ and digested with muriatic acid, rendered so weak as not to be able to decompose sulphuret of antimony. This degree of dilu- tion was determined by means of a paper dipped in acetate of lead ; but it was found that the acid when thus diluted would dissolve nothing whatever from the mineral. a Translated from the Kongl. Vetenskaps Academiens Handlingar for 1821, p. + The pulverisation of this mineral is attended with considerable difficulty, because the parts of it become at last scaly, after which it is far froma easy to reduce them to 4 finer powder, even under water, 30 M. Bonsdorff on the {Juny, The next attempt was to expose the mineral to the action of hydrogen gas, while at the same time heat was applied to it, in hopes that the hydrogen would reduce the oxide of antimony to the metallic state and form water, by the weight of which the quantity of oxygen in the mineral could be determined. But in order to satisfy myself in the first place that this theoretic spe- culation would accord with the nature of the bodies present, I undertook a set of experiments on the reduction of an artificial mixture of sulphuret and oxide of antimony by means of hydro- gen gas. The apparatus which was employed in these processes was constructed on almost the same idea as that described by Prof. Berzelius in his experiments on nickel glanse, arsenical nickel, &c. ; an outline of which is here given. (a ts pea pg Og Heese \ AEE EA ET PRY TTY yy yey WT Y/Y It consisted of a globular vessel, A, in which the gas was generated, a tube, C, filled with chloride of calcium, and a small apparatus for distilling. But this last apparatus, distinguished in the figure by the letters D E FG H, was, in my experiments, not terminated by the ball, F, and the crooked tube, G H; but had on that side merely a straight tube rather more than two inches long, which was fastened to the ball, E, by a caoutchouc tube in the same way as the apparatus, D E, only somewhat greater. This tube was filled with chloride of calcium in the same way as the tube C, and from A there passed a crooked tube to allow the gas evolved to make its escape. The gas was 1824.] Chemical Composition of Red Silver Ore. 31 enerated by dissolving granulated zinc in dilute sulphuric acid. All the different pieces of the apparatus were carefully weighed in the first place to enable me to determine what might be driven off, or what addition might be made to the substances operated on during the process. Experiments with a Mixture of Sulphuret of Antimony and Oxide of Antimony. Antimonious acid prepared from subantimonite of potash (crocus antimonii elota) by digestion in nitric acid, was mixed by trituration with its own weight of metallic antimony in fine pow- der, and put into a glass globular vessel blown by the lamp, having a capacity of fully a cubic inch, the mouth of which was. afterwards drawn out into a capillary tube. This glass vessel was put into a crucible, and was raised to a red heat, which was kept up about ten minutes. When the glass was broken in pieces, there was found in its upper part white or yellowish-white crystals, of two different forms ; namely, octahedrons and pris- matic needles. The mass found at the bottom consisted of a metalline regulus lying undermost, and overit an oxide consist- ing of a fused yellow-grey mass, having a crystallized fracture,. and containing drusy cavities, lined with white, short, needle-- shaped crystals. Sulphuret of antimony was prepared from this: regulus by mixing it with 40 per cent. of pure native sulphur, andi heating it in a little glass globular vessel. It was crystallized, and all excess of sulphur had been driven off by heat. ' The purest portions of the oxide thus obtained were pulve~ rised, and exactly mixed with the sulphuret of antimony, accord- ing to the proportions which Berzelius has given for the consti- tution of red ore of antimony (Rothspeissylanserz), Sb + 2 Sb S*; namely, 100 parts sulphuret with 43-2 parts of oxide. A quantity of this mixture was put into a glass globe blown by the lamp. This quantity after being gently heated weighed 2335 grammes. The glass was exposed to the flame ofa spirit-lamp, and as soon as the mixture became fully red-hot, it melted, and was found after cooling still to weigh exactly 2°335 grammes. The product of this operation was a glass having the metallic lustre and a dark steel-grey colour with a shade of red, very similar to the dark variety of red ore of antimony. It appeared” opaque, except those portions which had formed a thin crust on. the inside of the glass. These were translucent, and had a yel-- lowish-red colour. When reduced to powder, it had a dark reddish-brown colour. As the weight was not altered by the: fusion, it is obvious that it had lost no sulphur nor oxygen dur-- ing the process. A portion of the powder of this crocus, or compound of sul-- phuret and oxide of antimony, was put into the part of the: apparatus marked E, which, after being gently heated, weighed 32 M. Bonsdorff on the (Jury, 1-27 gramme. The caoutchouc tube was now fixed on, and all the other parts of the apparatus were adjusted to their places. After the hydrogen gas had passed over a good while, and the whole atmospherical air had been driven out of the tube, the powder was gradually heated by means of a spirit-lamp. Water began very quickly to be formed, and was deposited in the form of vapour on the sides of the glass globe. When the hydrogen gas passed over briskly, the aqueous vapour was carried off b the current, and was naturally absorbed by the chloride of cal- cium in G; but when the hydrogen gas passed over slowly, or only at intervals, the water collected in drops in the pipe. After the process had continued two or three hours, the antimoniacal mass had in part passed through the glass globe, and a little sulphur began to appear on its outside. The fire was of neces- sity withdrawn, and the process stopped. During the whole continuance of the operation sulphuretted hydrogen gas was disengaged, and conducted by means of the crooked tube into a glass containing liquid ammonia in order to prevent it from making its way into the room. Into the tube beyond the glass globe, 0°04 gramme of water had condensed, and the tube con- taining the chloride of calcium had increased considerably in weight. But it is needless to state this increase, because the portion of the chloride nearest the ammoniacal water had deli- quesced in consequence of the evaporation of a portion of that liquid into it. The residual matter in E weighed 1-005; and consequently it had lost in oxygen and sulphur 0:265 gr. It consisted of a multitude of small metallic reguli, and of a brass- yellow crystallized sublimate, which seemed to have the octahe- dral form. There was also a little sublimate in the tube, which had more of the metallic lustre, and was more shining, and which probably was merely sulphuret of antimony. The yellow crystallized substance dissolved with ease in aqua regia, and seemed to consist chiefly of sulphur. Decomposition of Red Silver Ore by Hydrogen Gas. When it was thus ascertained that hydrogen gas is capable of reducing oxide of antimony fromits combination with sulphuret of antimony, the same process was undertaken with red silver ore, and at the same time measures were taken to collect and decompose all the sulphuretted hydrogen formed during the process, that the quantity of sulphur in the ore might be like- wise determined. For this purpose a somewhat concentrated solution of sulphate of copper was prepared, and a portion of it (previously deprived of its atmospherical air by boiling) was put into two phials; and another portion supersaturated with am- monia, so that a clear solution was obtained, was put into two other phials. A new portion of chloride of calcium was put into the tube G, and its weight was again determined, and from 1824.) Chemical Composition of Red Silver Ore. 33 it there was a communication by means of glass tubes with the phials holding the solution of sulphate of copper. These again communicated with the ammoniacal solution of copper in the other two phials, by means of glass tubes passing through corks in the mouths of the phials, precisely as in a common set of Woulfe’s bottles. Into the glass globe E, a quantity of pulverised red silver ore was put, which, after having been gently heated, weighed 1-504 gramme. Then the whole apparatus was put in its place. When the evolution of the gas had continued for halfan hour, and the atmospherical air had been expelled, a spirit-lamp was applied to the ball E, and a stream of gas was made to pass equably and slowly. On the first application of the heat, a light coloured smoke appeared, and passed over into the pipe from E, but it vanished immediately, and left no trace behind it. Sulphuretted hydrogen gas was immediately formed, and instantly rendered the first phial turbid. Soon after a deposit began to appear in the second, then in the third, and at last even some deposit appeared in the fourth phial. In the ball and tube not the least trace of water made its appearance, and indeed nothing whatever but an exceedingly small quantity of smoke- like matter. After the heat had been continued without inter- ruption for eight hours, the mineral kad assumed the form of a metallic regulus, which easily melted by the heat of the spirit- lamp. And in the throat, and tube of the little apparatus E, an inconsiderable quantity of a greyish matter with the metallic lustre had sublimed. When the hydrogen gas ceased to be sulphureous, and the mineral to diminish any more, the gas was still allowed to pass for some time. The lamp was then put out, and the apparatus taken to pieces. The residue in the retort was found to weigh 1:2365 gr. The glass ball was broken, and the regulus taken cut; it weighed 1:2255 gr. It had externally the metallic lustre; but was here and there covered with a little black powder; but its quantity was so small that it could not be separated. Probably it was nothing else than small reguli in very fine mechanical division. The tube beyond the glass ball, though it contained the smoke-like matter, was not sensibly increased in weight. The chloride of calcium had become heavier by 0-010 gr. and it was observed that the partie cles of salt were a little soiled by a fine brownish-grey matter, The hydrogen had taken from the mineral 1-504 — 1:2365 = 02675 gramme, which amounts to 17°785 per cent. A set of experiments was now undertaken on the regulus, which exhibited all the characters of an alloy of silver and anti- mony. The object in view was to remove the antimony by cupellation, and leave the silver. But in the first place a set of experiments was made upon an artificial mixture of silver and antimony. New Series, vou, Vill. D 34 M. Bonsdorff on the [J ULY, Experiments to separate Antimony from Silver by Cupellation. Of this alloy, which was so formed as to contain about 31 _ cent. of antimony, and which in its fracture and aspect per- ectly resembled the regulus obtained from red silver ore, 0°738 gr. was placed in a bone-earth cupel, which was introduced into a red-hot muffle in a cupellating furnace. The heat in the muffle was increased by means of an air tube introduced into the muffle through a piece of charcoal placed in its mouth. The antimony was speedily driven off, and in great quantity; and when on increasing the heat, and blowing on the cupel with a bellows, no more antimonial fumes appeared, the silver regulus was withdrawn, and found to weigh 0°512 gr. It was ductile, and on the surface dull and greyish, showing that it was not quite free from antimony. It was, therefore, enveloped in five times its weight of pure lead, and exposed to the usual cupellat- ing process till it assumed the appearance of pure silver. The regulus now obtained was silver-white, had a strong metallic lustre, and weighed 0°507 gr. It amounted, therefore, to 68 per cent. of the antimonial alloy ; and the regulus first obtained contained about | per cent. of antimony. An experiment was made with another portion of the same alloy. It gave, after the first process, a dull regulus, whose weight was very nearly in the same proportion as in the experiment already described ; and when it was dissolved in nitric acid, it left behind it alittle oxide of antimony. The pure regulus obtained in the first experi- ment dissolved in that acid without leaving any residue what- ever. After these preliminary trials, 0-511 gr. of the regulus obtained from red silver ore was taken and treated in precisely the same way. The first process gave a regulus weighing 0°375 gr. dull, and with a yellowish-grey colour on the surtace ; and when it was cupellated with five times its weight of lead, it became silver-white and splendid, and weighed 0:370 gramme. It dissolved in nitric acid without any residue whatever, and gave with muriatic acid horn silver, weighing after fusion 0°490 gramme, equivalent to 0369 silver, and thus corresponding very nearly with the original weight of the regulus. According to this experiment, the whole regulus, weighing 1:2255 gramme, contained 0:8866 gramme silver, and the antimony driven off weighed 0°3389 gramme. The matter which had passed into the tube E weighed, as has been already mentioned, 0-011 gramme. The fragments of the glass to which that grey metallic-looking substance adhered, were digested in nitric acid, which dissolved a little sulphur, as was evident from the action of muriate of barytes on the liquid. What remained was dissolved in muriatic acid, and contained, as far as so small a quantity of matter could be tested, nothing 1824.] Chemical Composition of Red Silver Ore. 35 else than antimony. The sublimate, therefore, consisted of sulphuret of antimony. Its weight (determined by weighing the glass fragments before and after the digestion in the acids) was 0:0065 gramme. It consisted of course of 0:0047 antimony and 0-:0018 sulphur. When we subtract this 00065 from the 0:011 (the total weight), there remain 00045, which consisted of a brown-coloured earthy matter, but too small in quantity to be submitted to any tests to determine its nature. The sulphuret of copper which had precipitated in the differ- ent phials was collected on a filter, and well washed with water. It was then dissolved in aqua regia, which, after long digestion, left a light-yellow powder, consisting of sulphur. It weighed, when well dried, 0-106 gramme, and burnt easily, leaving a black- greyish residual matter, weighing scarcely a milligramme. The solution in aqua regia was precipitated warm by muriate of barytes. The sulphate of barytes obtained weighed 1-04 gramme, equivalent to 0°143 gramme sulphur. Thus the whole quantity of sulphur amounted to 0248 gramme. The matter deposited on the chloride of calcium might also contain a little sulphur, left on it by the warm sulphuretted hydrogen gas ; but it is impossible to determine its amount with accuracy. The preceding analysis of red silver ore gives us the following constituents : SSOWEER. cA RS o.cis\\0.0108 45,06 0:8866 or 58°949 Antimony oeeeereeeeeeee 0°34386 22°846 Sulphur........-eeeeeee 0:2498 16:°609 Earthy matter. ......+++- 0-0045 0:289 NS Cas co bates aaa @ * 00195 1:307 15040 100-000 If we examine this mineral in a theoretic point of view, we find that 58949 silver combine with 8°76 sulphur; and that 22-846 of antimony unite with 8-549 sulphur.. We see further that the sulphuret of silver is a compound of 1 atom silver and 2 atoms sulphur; while the sulphuret of antimony consists of 3 atoms sulphur and 1 atom antimony. ‘The chemical formula for red silver ore, therefore, must be, 3 Ag S* + 2 Sb 8%, which gives us its constituents as follows : BLIVED. a «a6 ss oipep sees s955 5 ini ean . 58°98 ANtiMONY ..eeerereeeeeeerererrres 22°47 Sulphur. ......eeseees dt bon RAG 17°55 99°00 Appendix. To explain the composition of red silver ore to the English readers, it will be merely necessary to substitute the atomic p 2 36 ‘Mr. Children on the Characters of some [Jury, weights of silver, antimony, and sulphur, as determined by Dr. Thomson, for the more complex numbers employed by Bonsdorf in the preceding calculations. The atom of silver weighs .......... 13°75 ANUIMONY « sienuceveese | OO sulphur. ..sscnecovsese 20 Red silver ore is a compound of 1 integrant particle of sul- phuret of silver and 1 integrant particle of sulphuret of anti- mony. Sulphuret of silver is composed of Patont silver. Og ee 04 E00. POTS 1 atom sulphur’. Soeed ei ieee le 20 15:75 Sulphuret of antimony of 1 ’atGht ANGMMUNY «5a aN daptiee sl as 4a.a8 1 LAfOI SUIDDUT » on.c5 act at pacar a 470M Hence the constituents of red silver are: 1, Atom SIVeR.. * « iiss.c mem cesien Lo (Ol Ose 1 atom antimony .......... 5°50 23°65 2 atoms sulphur. .... 02... 400° » 17-21 23°25 100-00 The numbers in the last column are exceedingly near the result obtained by Bousdorf. Indeed, if the loss in his analysis was sulphuret of antimony, as is exceedingly likely, the theoretic numbers almost coincide with those derived from the analytical experiments. AnTIcLE VI. On the Characters of some Mineral Substances before the Blow- pipe. By J.G, Children, PRS. Xc. Tux blowpipe, when skilfully handled, is the most convenient chemical instrument for mineralogical researches on a small scale that has hitherto been invented. By its means we are enabled in a few minutes to determine the principal ingredients in any mineral submitted to our examination, even though it be composed of several elements. By merely directing the flame of a small lamp on a fragment about half the size of a pepper- corn, supported on a piece of charcoal, or in the platina forceps, most of the volatile substances, as sulphur, arsenic, zinc, cad- mium, antimony, bismuth, and tellurium, may be detected ; 1824.] Mineral Substances before the Blowpipe. 37 baryta will be known by the greenish-yellow, and strontita by the crimson colour it imparts to the flame. By employing only three fluxes, carbonate of soda, borax, and the triple phosphate of soda and ammonia (salt of phosphorus), with the occasional use of the nitrate of cobalt, we can readily ascertain the presence of silica, alumina, magnesia, and almost all the fixed metallic oxides; and by the further examination of the fused globule, especially that with carbonate of soda, by dissolving it in a drop of muriatic or nitric acid, on aslip of glass, and applying the proper tests, unequivocal evidence may be obtained of the presence of any of the other earths or oxides of which the sub- stance 1s composed, and even a tolerable estimate may fre- quently be formed of their respective proportions. By substi- tuting nitrate of baryta as the flux, end using a slip of platina foil for the support, instead of the wire, the presence of either of the alkalies may, by the usual well-known processes, be de- tected, with equal ease and certainty, on the same minute scale of operation. An advantage peculiar to this microscopic chemistry is the very small quantity of matter that is sufficient for examination, which may generally be detached from rare and costly speci- mens without injury, whereas for operations on a larger scale, it is necessary wholly or in great measure to destroy them. When the exact proportions of the ingredients of a mineral are required, recourse must necessarily be had to more elaborate processes, but even then previous examination by the blowpipe is of essen- tial service, since by indicating the different substances present, it enables us to determine the most advantageous method to be adopted in the subsequent analysis. Convinced of the utility of this sort uf investigation, I propose, from time to time, to pub- lish in the Anna/s the blowpipe characters of such minerals as have not already been so examined. For those which form the subject of the present communication, [ am indebted to the kindness of Mr. Brooke. 1. Arfwedsonite. (Phillips’s Mineralogy, p. 377.) Alone in the glass matrass, gives off a very little moisture at a red heat : no decrepitation ; appearance of the assay scarcely at all altered. Alone in platina forceps, swells up, and fuses with great ease into a brilliant, opaque, black globule. With soda, on platina wire, in the oxidating flame, fuses readily into a dark-brown opaque globule, while hot; olive- green, cold. By the addition of nitre the green colour becomes much brighter. In the reducing flame the colour changes to a dark, slightly greenish-brown. With borax, dissolves readily, and gives a transparent globule of a garnet-red colour, hot, which changes to a deep wine-yellow 38 On some Mineral Substances before the Blowpipe. [Juty, on cooling. In the reducing flame, the colour is a deep bottle- reen, ~ With salt of phosphorus, the action is very slow and imperfect; the globule is transparent, and, while hot, has a deep wine- yellow colour; when cold, it is colourless. In the reducing flame the colour is lighter, and more inclined to green, while hot ; when cold, colourless. A considerable portion of the assay remains undissolved, in the form of a dark-grey silica skeleton. 2. Latrobite. (Phillips’s Mineralogy, p. 380.) Alone in the glass matrass, ata red heat, gives off pure water; no decrepitation. Alone in forceps, fuses easily into a white enamel. With soda, fuses into a semi-transparent, irregular globule, of alight azure colour, when cold. The colour of the globule is not uniform, spots of a deeper colour than the rest appearing scat- tered over the surface. By the addition of nitre, the blue colour is at first much exalted, and assumes a very slight greenish hue; but by long continued flaming, the blue colour disappears, and is succeeded by a peach-blossom red colour, very similar to that of the mineral. In the reducing flame, the colour is wholly destroyed. With borax, dissolves very slowly, into a perfectly transpar- ent, very light amethyst-coloured globule. In the reducing flame, the colour entirely disappears. With salt of phosphorus, action slow, and solution imperfect ; elobule transparent, very light-yellow, hot; colourless and slightly opaline, cold. In the reducing flame, the globule is colourless and transparent, both hot and cold. An undissolved silica skeleton remains in the globule. With nitrate of cobalt, the assay gives a fine blue colour, intensely deep on the fused edges. By dissolving the soda globule in muriatic acid, &c. | obtained silica, alumina, lime, iron, and manganese. The latrobite is accompanied by a dark-coloured, nearly black substance, dispersed through it, here and there, in minute specks, which have an uneven, shining fracture, but are too small to allow me to distinguish any thing more of their external characters. With salt of phosphorus, they presented before the oxidating flame the phenomena detailed above, but in the reducing flame, they gave a transparent glass, colourless while hot, and of a fine, rather deep-amethyst colour when cold. This colour flies instantly on the globule being heated, and on its cooling to a certain point, returns as instantaneously. These dark specks, therefore, appear to be an ore of titanium. I examined the mica, which is another concomitant of latro- 1824.] On the Power of Bodies to conduct Electricity. 39 bite, thinking it possible that it also might contain titanium ; but it gave no indication of that metal, either when fused in the reducing flame, with salt of phosphorus alone, or with the addi- tion of a small morsel of tin-foil. 3. The Matrix, or greyish-coloured substance, in which the latrobite is imbedded. Alone in the matrass, behaves like latrobite; appearance unaltered. In forceps, bubbles up, and fuses into an irregular greyish globule. — With soda, in proper proportion to the assay, fuses into a greenish-grey, semi-transparent globule, which in the reducing fiame is colourless. On platina foil, with soda and nitre, very slight indication of mangarlese. ith borax, dissolves very slowly ; globule transparent, and deep-yellow, hot 5 colourless, cold; in the reducing flame nearly the same, but colour lighter, and more inclining to green. With salt of phosphorus, nearly as with borax, except that the action is still slower, the yellow colour, in either flame, lighter, and without any tinge of green. A silica skeleton remains undissolved. With nitrate of cobalt, dirty-rose colour; the fused edges purple. From the last result, the grey substance appears to contain a considerable portion of magnesia. I hope before long to give the analysis of the three preceding minerals. —_—_—— ArticLE VII. Abstract of the Report on M. Rousseaw’s Memoir respecting a new Method of measuring the Power of Bodies to conduct - Electricity. By MM. Ampere and Dulong.* M. Rousseau, who has been occupied several years in the construction of dry voltaic piles, with the view to discover the circumstances which modify the energy and duration of their action, conceived the idea of employing those instruments to appreciate the different degrees of conducting power of the sub- stances arranged in the class of bad conductors of electricity. For this purpose he has contrived the apparatus we are about to describe. The dry pile, which forms the principal part of it, is made of discs of zinc and tinsel, separated by pieces of parch- ment, soaked in a mixture of equal parts of oil of poppies, and essence of turpentine; the whole is covered laterally with resin to prevent the contact of the air. The base of the pile * Fromthe Annales de Chimie. 40 On anew Method of measuring the [Juny, communicates with the ground. Its upper extremity may be connected by a metallic wire with an insulated vertical pivot, carrying a weakly magnetic needle, balanced horizontally. On a level with the needle, and distant from the pivot, about half the length of the latter, 1s a metallic ball, also insulated, but communicating with the pile. It is evident that by this arrangement, the electricity accumulated at the upper pole of the pile, is communicated to the needle and the ball, and con- sequently repulsion ensues, tendmg to separate the needle, which is moveable, from the ball which is stationary. If we place the pivot and the ball in the magnetic meridian, the needle touches it, and remains at rest as long as the apparatus is not connected with the pile; but the instant the communication is established between them, the needle is repelled, and after some oscillations takes its position of equilibrium, depending on its magnetic power and the energy of the pile. These two quanti- ties remain constant for a considerable time, with the same appa- ratus, as may be ascertained, by determining the angle which the needle makes with the magnetic meridian, after it has assumed a fixed position, by means of a divided circle adapted to the cage which covers it. A simple conducting needle suspended by a metallic wire of proper diameter and length, might be substituted for the magnetic one; but M. Rousseau’s apparatus is much more convenient, and sufficiently sensible for the kind of effect which it is his object to measure. To use it for ascertaining different degrees of conducting power, it is sufficient to place the substance submitted to expe- riment in the electrical current, taking care that the thickness which the electricity has to pass through be always equal. If the flow of the quantity of electricity necessary to produce the greatest deviation be not instantaneous, the time required by the needle to assume its fixed position, may be taken as the measure of the degree of the conducting power of the substance em- ployed. To submit liquids to this kind of examination, M. Rousseau places them in small metallic cups, communicating by their foot with the needle and the ball: he then places in the liquid one of the extremities of the metallic wire, covered with gum lac, that the same surface of metal may always be in contact with the fluid, and measures the duration of the needle’s motion from the moment when the communication is established with the pile by the other extremity of the wire. By submitting the fixed vegetable oils employed in the arts and in domestic economy to this kind of proof, M. Rousseau has established a very singular fact, which may be useful in com- merce ; it is that olive oil possesses a very inferior degree of conducting power to that of all the other vegetable or animal oils, which nevertheless present, in all their physical proper- 1824.] Power of Bodies to conduct Electricity. 4] ties, the strongest analogies to that substance. For instance, every thing being equal in both cases, olive oil required forty minutes to produce a certain deviation, while poppy oil, or the oil of the beech-mast, required only twenty-seven seconds to produce the same deviation. One-hundredth part of any other oil added to oil of olives reduces the time to ten minutes. It would, therefore, be easy to discover by means of this mstru- ment the smallest traces of any oil fraudulently mixed with oil of olives. If the proportion of the foreign substance be considerable, the difference of time necessary to produce the maximum of effect would no longer be sufficiently great, and could not be measured with sufficient precision to indicate the proportion of the elements ; but the apparatus might easily be modified so as to adapt it to this kind of determination. The solid fats are worse conductors than the animal oils, aris- ing no doubt from the large proportion of stearine contained in the former; for M. Rousseau is satisfied, by comparative trials with stearine and elaine, prepared by M. Chevreul, that the conducting power of the latter much exceeds that of the former. The fat of an animal becomes a worse conductor in proportion to the age of the individual which afforded it. By means of the same apparatus, we may also observe a nota- ble difference between resin, gum lac, and sulphur, the most insulating of all known substances, and silk, crystal, and com- mon glass. j M. Rousseau has not found any difference in the conducting power of liquids, whether spirituous or aqueous, acid, alkaline or neuter, the time required by the needle to arrive at the maximum of deviation being too short, in every case, to ascertain the inequality of its duration. But a modification of the apparatus, similar to that for determining the proportions in an oleaginous mixture, would easily appreciate that difference. It would be equally possible, and very curious, to try the effect of the two kinds of electricity on different substances ; all that would be necessary would be to place the two poles alter- nately in connexion with the ground. According to Ermann’s results, it is probable that a difference would be found between some substances. 42 M. Bequerel on the Electro-motive Actions [Juny, Articte VIII. Abstract of M. sa hich Paper on the Electro-motive Actions produced by the Contact of Metals with Liquids, and on a Pro- cess for ascertaining, by Means of the Electro-magnetic Effects, the Change which certain Solutions undergo by Contact with the Air. (Read before the Royal Academy of Sciences, April, 1824.)* In former papers presented to the Society, M. Bequerel had attributed the electrical effects observed during chemical action, solely to the play of affinities exerted between the combining bodies ; concluding that during such action the alkali takes positive, and the acid negative electricity, and neglecting to take into the account the effect resulting from the contact of the acid with the platina cup which contained it, and that of the alkali on the jaws of the forceps (which were also of platina) in which it was held, an action, however, which must by no means be overlooked. The apparatus which M. Bequerel employed in his present experiments is similar to the electroscope invented and described by M. Bohnenberger, in the Bibliotheque Universelle, Nov. 1820 (see also Annales de Chimie, 1821, vol. xvi.), but instead of two drv piles placed vertically, he uses only one placed in a horizontal position, on a wooden support ; to each pole a metal- lic plate, about three inches long, is fixed vertically, between which the gold leaf is suspended, in contact with the lower plate of the condenser; the condensing plates being nine inches in diameter. The delicacy of this instrument is such that it is sensible to the action of an excited glass tube at the distance of eight or ten feet. A brass capsule, containing an alkaline solution, was placed on the upper plate of the condenser, and a communication esta- blished between it and the ground by touching it with the finger, or a moistened slip of gold-beater’s skin, the lower disc being also in connexion with the ground ; in a few seconds after, the upper plate was removed, and the gold leaf flew to the positive pole; consequently the alkaline solution had become positive from contact with the copper, and the metal negative. When sulphuric acid was substituted for the alkaline solution, the electricities were reversed. To ascertain the electro-motive action of different metals by contact with acid and alkaline solutions, a capsule of the metal containing the solution was placed on the upper plate of the condenser; the lower plate was then touched with a slip of the * From the Annales de Chimie, 1824.] produced by the Contact of Metals with Liquids, &c. 48 same metal, and the liquid with the finger; thus the electro- motive action arising from the contact of the metal under exa- mination with the copper was destroyed, and only the electricity which it had acquired by its contact with the solution remained on the upper plate of the condenser. It is sometimes necessary to place a slip of paper between the metal experimented on and the copper, for the apparatus is so sensible, that a very slight difference in the state of their surfaces would modify the electro- motive action. Operating in this way, it was found that by contact with an alkaline solution, the metal, whenever its electrical state can be determined, becomes negative; and positive with an acid; but with silver, and in many other instances, the electro-motive action is too feeble to be rendered sensible. These results confirm and extend the observations formerly made by Sir Humphry Davy on the electrical effects produced by the contact of metals with acids and alkalies, in a perfectly dry and solid state, between which there is consequently no chemical action; for they prove that similar effects ensue when - the latter substances are in solution, and even when in some cases the contact is accompanied by incipient chemical action. In order to understand what is the influence of the fluids in- terposed between the plates of the voltaic instrument, and whether it has any other action than that of a mere conductor to transmit the electro-motive action of the metals from one to the other, it is necessary to ascertain what happens when an acid or alkaline solution is placed between two dissimilar metals. For this purpose, the copper capsule, filled with either an acid or alkaline solution, was placed on the upper plate of the conden- ser, as before; the solution was then touched with a plate of zinc (taking care not to touch the copper with it), and the lower plate of the condenser with the finger, and after a lapse of twenty seconds, the upper plate was removed; the gold leaf flew to the positive pole ; consequently the copper capsule had become positive. The experiment was reversed by using a capsule of zine filled with either solution ; and the lower plate of the condenser was touched with a plate of zinc to destroy the electro-motive action between the capsule and the plate, and a plate of copper, held between the fingers, was immersed in the solution. On raising the upper condensing plate, the gold leaf flew to the negative ee and consequently the zinc capsule had become negative. e see from these two experiments, that when zine and copper are separated by an acid or alkaline solution, the copper becomes positive and the zinc negative ; just the reverse of what takes place between these metals by simple contact. “We have also,” says M. Bequerel, “ examined what takes place on the contact of a metal with a saline solution; as cop- 44 M. Bequerel on the Electroemotive Actions, &c: [Juy, per with solution of sea salt; the copper becomes negative, and the solution positive. This result explains why a plate of cop- per in contact with zine or tin, as lately ascertained by Sir H. Davy, is less acted on by the sea-water than when not in contact | with an electro-positive metal. It cannot be denied, that two substances at the moment they combine are in different electri- cal states, and that there is a certain relation between those states and the chemical affinities. Now if we can modily those electrical states, it is almost certain that we shall also modify the play of affinities ; but we have seen that a plate of copper, by contact with a solution of sea-salt, becomes negative ; it follows that if we touch the same metal with an electro-positive metal, the copper will be placed between two bodies, each tend- ing to impart the same kind of electricity, a condition which we know will tend to annul the electro-motive action of the copper on the solution of sea-salt. Thus, according to the electro-chemical theory, circumstances are so arranged as to weaken the chemical action of the solution of sea-salt on the copper.” The memoir concludes with pointing out a method by means of electricity, of ascertaining the changes which some solutions experience by contact with the air. Dissolve iron in nitric acid; filter the solution, and immerse into it two lamine of platina, each communicating with one of the extremities of the wire of the galvanometer ; leave one of the wires in the solution, withdraw the other, and again immerse it ; it will be positively electrified. The nitrates of copper and lead give similar results for a short time ; nitrate of zinc produces no such effect. When the experiment is made in an atmosphere of hydrogen, no electrical current is established, though all circumstances, except the want of contact with the atmosphere, are precisely similar in both experiments. “ Hence the contact of atmospheric air is indispensable to the production of the electrical current by the immersion of platina lamine in several fresh-prepared nitrates; but what is the modification that is instantaneously effected in the liquid adhering to the surface of the lamina withdrawn from the solu- tion? We can, toa certain extent, explain this: The solution of a metal in nitric acid gives rise to several compounds : take iron, for instance ; first deutoxide of azote is formed, and soon after nitrous acid, a protonitrate and a deutonitrate ; by degrees the deutoxide of azote passes to the state of nitrous acid, the proto- nitrate to that of deutonitrate, and, after a certain time, only deutonitrate remains in the liquid. According to this state- ment, when we withdraw one of the platina lamine from the solution, the liquid which adheres to it immediately, in conse- quence of the thinness of the stratum, experiences changes from 1824.] Deoxidating Property of the Vapour of Water. 45 the action of the air, which do not take place till after several hours in the bulk of the solution. It follows, therefore, that when we re-immerse the lamina, we bring in contact two dissi- milar liquids, and nothing in that case opposes the production of an electrical current. “ On the other hand, since the immersion of platina lamin in a solution of nitrate of zinc does not produce any current, although it contains deutoxide of azote and nitrous gas, it is probable that this may be owing to the nitrate not suffering any change by contact with the air, in consequence of the metal being capable of forming only one oxide.” ArtTicLe IX. On a deoxidating Property of the Vapour of Water. By C. H. Pfath* Ir was remarked by Hermbstadt, while making the experi- ments from which he deduced the existence of a peculiar colour- ing principle in sea-water, and its superincumbent atmosphere, that if that liquid be boiled in a retort, and if, by means of a glass tube attached to the beak of the retort, the gases and aqueous vapour evolved be made to pass through a solution of nitrate of silver, the latter by degrees assumes the colour of ved wine, and at the end of 24 hours, a brownish-yellow coloured sediment is deposited. I observed the same appearance, on repeating this experiment with sea-water from the bay at Kiel. As, however, I had reasons for suspecting that this change is not occasioned by any peculiar gaseous constituent, I prepared an artificial mixture of solutions of the muriates of magnesia and scda, in the proportions which constitute sea-water, and on making the ex- eriment with this, I still obtained the same result. I cbserved also that the colour imparted to the solution of nitrate of silver at the beginning, and towards the conclusion ofthe experiment, is different: at first it is a weak violet, but after the experiment has gone on for some time (provided there be a sufficient quan- tity of the metallic salt in the vessel through which the vapours ass), it has a considerable infusion of reddish-brown, tence considered it not unlikely, that in these experiments there are two distinct causes which produce discoloration. This induced me to repeat the experiment in a variety of ways ; which at last conducted me to the following very interesting results. The experiments themselves are extremely simple. The * Schweigger’s Journal fiir Chemie und Physik, xxxvi. 68. + This opinion was refuted by Pfaff in a small pamphlet, entitled Day Kieler See- bad verglichen mit andern Seebiidern an der Ostsce und Nordsee, Kiel, 182. 46 M., Pfaff on a deoxidating Property of [Juny, liqiids were boiled in clean glass retorts, and great care was taken to prevent any portion of them from being carried over mechanically in the state of drops. The solutions on which the action of the gases and vapours expelled by boiling was to be determined, were contained in Woulfe’s bottles, and, in general, the vapours passed through two or three of these in succession. The tubes of communication between the retort and the first bottle, and between the bottles themselves, were plunged to a sufficient depth in the solutions. 1. The mere vapour of pure distilled water when passed through a transparent solution of nitrate of silver, has the property of communicating to it a discoloration, in proportion as it heats the solution to the temperature of ebullition; and the intensity of this discoloration varies from yellow to dark-brown, according to the concentration of the solution, and to the length of time during which it has been exposed to the action of the vapour. 2. This discoloration is inconsiderable, so long as the solution of nitrate of silver remains under the boiling point, but it becomes exceedingly striking, the instant ebullition commences. The colour which first appears is yellow, but it rapidly becomes darker. The colour of the solution of nitrate of silver, when sufficiently diluted, has a close resemblance to red wine. 3. In the same manner, the solutions of nitrate of silver in the remaining bottles may be discoloured; because the vapour, after heating the liquid contained in one bottle, passes over into the next, and raises its temperature also to the point of ebullition. 4. This discoloration is caused by a deoxidation of the nitrate of silver, and except that it. takes place with much greater rapi- dity, it is similar in all respects to the effect produced by light. In proof of this we may mention, a. The similarity of the colours with those produced by the action of mere light. 6. The com- plete removal of the colour, and restoration of transparency, by the addition of nitric acid. c. The similar deoxidizing effect of the vapour of water upon other metallic solutions, which are easily deoxidized, either by light, or by some chemical action. d. The disengagement of oxygen gas during the process. 5. The most convincing of all proofs is furnished by a solution of muriate of gold. A solution of this salé so much diluted as scarcely to retain a shade of yellow, when heated to the boiling point by a stream of the vapour of water, acquires a beautiful blue colour, exactly similar to the colour produced in it by tinc- ture of nutgalis, oxalic acid, Xc. 6. After the expulsion of the atmospheric air, I collected the gas which was disengaged in a constant stream of minute bubbles, from the boiling-hot solution of nitrate of silver. It proved to contain a considerably greater quantity of oxygen than common air: 100 volumes of it mixed with 100 volumes of nitrous gas, sustained a diminution amounting to 91, whereas common air sustained a diminution of only 80. 1824.] the Vapour of Water. 47 7. Of the other solutions whose colour is changed by deoxi- dation, I examined acetate of silver, which became discoloured, like the nitrate, but more feebly; and muriate of platinum, which underwent no alteration. 8. Sea-water and solutions of common muriate of soda and of muriate of magnesia, when boiled, and when the disengaged vapour is passed through a solution of nitrate of silver, occasion appearances of a more complicated nature. In this case, the metallic solutionis decomposed, not merely by aqueous vapour, but by the muriatic acid which is disengaged from the boiling liquid ; and a quantity of chloride of silver is formed, which the action of the aqueous vapour subsequently renders violet- coloured, provided it at the same time raises the temperature of the solution of nitrate of silver to the boiling point. Should any portion of the nitrate of silver be left undecomposed, it is deoxi- dized by the vapour of water, and a yellow or brown colour is developed, which mixes with the violet, and imparts to it various modifications of shade. My original opinion, therefore, that the change of colour is caused by the muriatic acid which distils over along with the water, is confirmed, but at the same time restricted, by this experiment. Muriatic acid 1s also dis- engaged from a boiling solution of the common muriate of soda, although in much smaller quantity, than from a solution of muriate of magnesia. Whether in the case of muriate of soda, the acid proceeds from a small residue of muriate of magnesia, or muriate of iron, I do not venture to determine. Neither of the bases (soda, magnesia) appears to pass over: at least, the distilled water leaves ne residue when evaporated. 9. This yellow, reddish-brown, or dark-brown coloured solu- tion of nitrate of silver, produced in so remarkable a manner by the deoxidizing action of aqueous vapour, retains its colour fora long time unaltered, but it at last deposits a dark-brown oxide of silver. 10. If previously to the introduction of aqueous vapour the solution of nitrate of silver be raised to the boiling point by the immediate application of heat, it does not completely retain its transparency after having been exposed as usual to a current of the vapour, but the discoloration which it sustains is greatly inferior. \ The deoxidizing property of aqueous vapour, demonstrated beyond a doubt by the foregoing experiments, deserves to be still further investigated, and would, perhaps, already admit of some practical applications, It is my intention to continue my experiments on the subject. Before concluding, I may observe, that the vapour of water does not appear to produce auy change upon a solution of corrosive sublimate, or upon solutions of the protoxide or peroxide of mercury in nitric acid. 48 Mr. Woodward on the Transmission of (Jury, ARTICLE X. On the Transmission of Electricity through Tubes of Water, &c. By Mr. C. Woodward. (To the Editor of the Annals of Philosophy.) SIR, June 5, 1824. On perusing the last number of your Annals, 1 okserved a letter signed T. J., informing me “ that the experiment of firing loose gunpowder by passing the charge of a leyden phial through tubes filled with water, and also on the conducting power of alcohol, ether, and acids, were made by a Mr. Lewthwaite, in May 1821; and are published in the eleventh volume of the Institution Journal:” the natural inference of which, I appre- hend, is, either that I published some experiments as new, which were not so; or that I gaye as my own, the experiments of another. If T, J. will refer to my letter, I think he will perceive that my object was to offer a theory in explanation of a singular phenomenon, and not merely to state the fact of the inflamma- tion of loose gunpowder, or the conducting power of alcohol, ether, and acids. For this purpose I introduced the subject as briefly as I could, and then enumerated the experiments, which led me to conclude that the theory I offered was the cor- rect one. “It was (observes T. J.) from reading this letter that I be- came acquainted with the experiment.” This, however, was not the case with myself, as the effects of electricity on loose gunpowder, when transmitted through tubes of water, were communicated by me to Mr. Lewthwaite some time previous to the publication of his letter. It is extremely painful to speak of one’s self; therefore, in my last communication, I avoided any allusion to what I had done elsewhere; but considering myself now called upon to explain, allow me, through you, to inform T. J. that | intro- duced the experiment in my concluding lecture on Electricity, at the Surry Institution, in December 1820; observing at the same time, that I could not offer any theory in explanation, the experiment having been but a few hours communicated to me by my much esteemed friend, Mr. Knight Spencer, the Secre- tary to the Institution. Early in 1821 I instituted a series of experiments to ascer- tain the cause; and, although I had then no explanation to offer, my experiments would have been presented to the public through the medium of one of the philosophical journals, had not the appearance of Mr. L.’s letter in the Institution Journal 1824.) Electricity through Tubes of Water, 49 superseded the necessity of it—In 1823 I again introduced the subject in my course at the Surrey Institution—when the experi- ments and theory noticed in my former letter to you, were offered in explanation—and I was induced to suppose my com- munication would not prove unacceptable, by the recent in- quiries of some scientitic friends who were anxious to know if I could explain the cause of so singular an effect—among whom was Mr. Lewthwaite, the writer of the letter alluded to by T. J. _ I now turn to a more pleasing part of the subject, that of investigating experiments. “ Would suggest (continues T. J.) that Mr. W. should re- peat the experiment with the water tube. I am disposed to think Mr. W. is in error, when he says the intensity (measured we are to suppose by a pith ball electrometer), indicated, was from 10° to 15°.” The supposition in the parenthesis is per- fectly correct, and I can assure T. J. I have too often repeated the experiment, and made too many notes upon the subject in con- junction with my electrical friends, to be im error, I have very frequently succeeded in the experiment with a quart jar, when the electrometer has indicated an intensity of only 10°, but not inyariably ; hence I stated in my letter, “ an intensity of from 10° to 15° is generally sufficient.” Had I noticed all the minute peculiarities I have observed on this head, my communication would have been much too long for insertion, and as no particular point turned upon the question, I con- sidered it sufficient to express myself in terms to be understood by an Electrician, without unnecessarily intruding upon your valuable pages. I must, however, inform T. J. that the success of the experiment, with a low degree of intensity, will greatly depend on the quality of the gunpowder, as well as the care taken to prevent the dissipation of the electrical fluid, for with very coarse powder I have been unable to perform the experi- ment at all. T. J. lastly observes, ‘ it would have been more satisfactory if the degree at which the jar spontaneously discharged itself, had also been stated.” This 1 confess myself at a loss to comprehend, for I have always found the spontaneous discharge of a jar, when mounted in the usual way, to depend as much upon what may be termed casual circumstances, as any ex- periment connected with electricity. At one time I have seen a spontaneous discharge take place at 50°; at another, the same jar, with the same electrometer, has been charged to 90°, without a spontaneous discharge. This suggestion, if reduced to practice, would be rather an expensive one to me, as my jars are all furnished with internal paper rims, according to r. Singer’s plan—the metallic rods communicating with the inner coatings are passed through stout glass tubes, cemented New Series, vou, VIIl. E 50 Mr. Smithson on Mr. Penn’s Theory concerning [(Juuy, in the caps of the jars, and the uncoated surfaces are var nished, so that a spontaneous discharge seldom or ever takes place without fracturing the jar. I am aware that the Pith Ball Electrometer is a very un- certain standard; and if my theory had depended on the degree of intensity required to produce the effect with a jar containing a given extent of coated surface, I should have used the balance electrometer, invented by Mr. W. S. Harris, of Plymouth, a description of which may be seen by referring to page 77 of “ Observations on the Effects of Lightning on Floating Bodies, by W. 8. Harris. London, 1823.” I trust T. J. will continue the experiments, which, when well matured, he has promised shall be submitted to your con- sideration; and, if he thinks I am in error, or has discovered any facts which may militate against my opinions, I will either most cheerfully answer them in the true spirit of philosophy, which teaches us “to agree to differ,” or I will prove to him that T am not wedded to any system, and that no one would more readily sacrifice a favourite theory, at the shrine of truth, than myself. Should he, on the other hand, require any information on a subject which has been for some years my favourite study, [ shall feel much pleasure in making the communication, if im my power. I am, Nir, your obedient servant, CuarLes Woopwarp. ARTICLE XI. Some Observations on Mr. Perm’s Theory concerning the Forma- tion of the Kirkdale Cave. By James Smithson, Esq, FRS. (To the Editor of the Annals of Philosophy.) SIR, June 10, 1824, No observer of the earth can doubt that it has undergone very considerable changes. Its strata are everywhere broken and disordered; and in many of them are enclosed the re- mains of innumerable beings which once had life; and these beings appear to have been strangers to the climates in which their remains now exist. In a book held by a large portion of mankind to have been written from divine inspiration, an universal deluge is recorded. It was natural for the believers in this deluge to refer to its action, all, or many, of the phenomena in question; and the more so as they seemed to find in them a corroboration of the event, Accordingly, this is what was done, as soon as any desire to account for these appearances on the earth became felt. 1824.] the Formation of the Kirkdale Cave. 51 The success, however, was not such as to obtain the general assent of the learned; and the attempt fell into neglect and oblivion. Able hands have lately undertaken the revival of this system ; Mr. Penn has endeavoured to reconcile it with the facts of the Kirkdale Cave, which appeared to be strongly inimical to it. Acquainted with Mr. Penn’s opinions only from the “ Ana- lysis of the Supplement to the Comparative Estimate” in the Journal of the Royal Institution for January, not having seen this Supplement itself, the Comparative Estimate, nor even a review of this in a former number of the Journal, and knowing of Mr. Buckland’s Relique Diluviane, only the account of the Kirkdale Cave published in the Philosophical Transactions for 1822, I have hesitated long about communi- cating the present observations, which presented themselves curing the perusal of the above-mentioned slender abstract. I have yielded to a sense of the importance of the subject in more than one respect, and of the uncertainty when I shall acquire ampler information at more voluminous sources—to a conviction that it is in his knowledge that man has found his greatness and his happiness, the high superiority which he holds over the other animals who inhabit the earth with him, and consequently that no ignorance is probably without loss to him, no error without evil, and that it is therefore preferable to urge unwarranted doubts, which can only occasion additional light to become elicited, than to risk by silence to let a ques- tion settle to rest, while any unsupported assumptions are in- volved in it. If I rightly apprehend Mr. Penn’s ideas, they are these: Secondary limestones were originally in a soft state. The waters of the deluge while elevated above England, de- posited on it a layer, or bed, of “ a soft and plastic” calcareous matter. On their departure from the earth, by flowing away towards the north, they floated over England the carcases of a number of tropical animals, clustered together into great masses. These masses became buried in the calcareous mud. On the sinking of the waters of the deluge below the sur- face of England, the bed of calcareous mud began to dry, and on doing so completely, became the present Kirkdale rock. The clustered animal bodies enclosed in the calcareous paste, by putrifying, evolveda great quantity cf gas, which forced the limestone paste in all directions from them, and thus generated the Cave in which Mr. Buckland found their bones. Soft State of Secondary Limestones. That secondary limestones have been in a state to admit fo- E2 52 Mr. Smithson on Mr. Penn’s Theory concerning (Jury, reign bodies into their substance, their existence in it is evi- dence. Every shell and stone on the beach tells by its rounded form the attrition to which it is subject at each flood and ebb of the tide ; and that a subtil powder is abraded from it which is col- lected somewhere. From the immense multitudes of marine bodies which exist in some of these limestones, from others consisting in fact entirely of them, from in general little or nothing but calcare- ous matter being present, it becomes highly probable that it is to the calcareous part of marine animals, more or less com- minuted, that secondary limestones owe their origin. Deposition of the Calcareous Mud. The waters of the deluge had not, surely, either a duration or power, to obtain the matter of this supposed layer of mud, No shores any longer existing, shells could not be pulve- rised by the beat of the wave, for it is not deep under water that such destruction is effected; nor, was it. so, would the short period of a year have been sufficient to produce the ma- terial of all the secondary limestones of the earth ? To have harrowed up this matter from the depths of the ocean, would have required an agitation of the waters, which nothing warrants us in giving to them, which every thing denies their having had. No hurricanes, no tempestuous winds, no swollen billows, are recorded. ‘To drown mankind they were superfluous, A wind having arisen at the termination of the calamity tells that none existed before; and this wind must have been a most gentle one, a very zephyr. A vessel, bulky beyond all the efforts of imagination to figure, so laden, so manned, could not have lived in any agitated sea, least in one which out-topped the Alps, and the Andes, all that could curb its fury, and mitigate its violence. Had the ark not foundered, which is impossible, what yet had become of the millions which its sides enclosed? Few had survived to repair the effects of the divine wrath, The waters must have been at rest when the ark continued stationary for many mouths on the mountains of Ararat. Nor, do the agitations of a sea extend far below its surface. What navigator has told of the storm in which the sea became thick with its own sediments ? But had such a deposit been made on our island, it would not have continued on it, Standing like a little turret in the bosom of the waters, each agitation of them would have pre- cipitated part of it down its sides. Their gigantic tides must alone have washed it away, and on the rush of their final depar- ture, not a vestige of it could possibly have remained behind. 1824.1 thé Formation of the Kirkdale Cave. 53 If dhe waters of the deluge placed a bed of calcareous matter on England and Germany, they must have done so over the entire earth. It must have been an universal stratum. Yet so total was the deficiency of it at Botany Bay, that the first settlers, for the very little lime which a few structures of immediate necessity required, were compelled, though spare as were the hands, and much as they were wanted for other purposés, laboriously and tediously, to collect shells along the beach, Where a limestone nodule was so anxiously sought and could not be found, great strata could not be near. But the sediment of the deluge waters would not be mere calcareous matter. It must have consisted of every thing which they could receive, suspend, and deposit. Tf over the earth were spread such a layer of mire, Noah and the animals could not have landed upon it. Or had the not stink into it and been smothered; where yet had the retil found refuge from the voracious; where had the herbivorous found food ? What a tite must have elapsed before Noah could cultivate the vine! Nor is it from such a soil that the wine would have intoxicated the holy Patriarch. Had things so been, Ham never had offended, nor Canaan incurred the fatal curse. Sinking of the Bodies into the Mud. Supposing, however, such a bed of “soft and plastic” caleareous matter deposited by the waters on England, the im- mersion of the bodies into it is of no small difficulty. Animal bodies bloated with gas from decay, which water had “floated on its surface,” are not easily conceived to have displaced a stony powder of a specific gravity of 2-7, and to have fallen below it. “ Turbulent vortices,” which are imagined to have lent their aid on the occasion, would have disseminated the clustered animals, and dispersed the powdery stratum. That the bodies should in every case have descended into the calcareous pulp, in one uabioker eroup; that in none a fragment, even a lock of hair, should have parted from the putrid mass, and stopped by the way, cannot certainly plead probability in its favour. Yet what cabinet shows even the slen- derest bone of a water-rat bedded in the solid stone? What limestone stratum has astonished the learned, by presenting them, in its substance, with an antediluvian hywna’s bristles, or lion’s mane? Formation of the Cave. If the limestone pulp was too thin, the gas would pass through it and escape, and the pulp fall back upon the bodies ; if too thick, the elastic force of the gas would be insufficient to repel it from them, A precise point of induration, at 54 Mr. Smithson on Mr. Penn’s Theory concerning {Jury, which it would at once yield and resist, was indispensable. This exact condition would but rarely occur; would, at least, often not do it, and consequently bodies buried in the solid rock must be frequent, if not most so. It is incredible that in every case the gas should have driven away from the bodies the whole of the mud in contact with them. Some of the mud must have insinuated itself between the several individuals of the cluster, some have penetrated by the mouth, by lacerations, into the cavity of the bodies, and isolated pieces of rock must now occur among the bones, bearing the impression of the parts with which they had been in contact; as at Pompeii, indurated ashes presented the cast of a woman’s breasts. As the parts receded from the bodies, it would carry with it some adhering fragments of them—bones, teeth, hair, feathers ; and which would now be fixed to the sides and roofs of the caves. Bodies which had been -previously putrefying for twelve months in a tropical temperature, would not probably have still afforded, after their interment, sufficient gas for the sup- posed purpose. From some experiments, made a great number of years ago, on the decay of animal muscle confined over mercury, I am inclined to believe, that in no case, when secluded from oxygen, is any great volume of gas evolved by it. Subjected to the imagined pressure, would the matters of the gases have been able to expand to the elastic form? Would they not rather have assumed the fluid one? Under these circumstances, would the muscular part of the bodies have entirely disappeared? Would not some portion of it have altered to adipocire? In such a state some of it must at least sometimes be met with. That fish have, in some cases, been inclosed in strata, in- vested with all their muscular part, seems indubitable, from the presence of the scales; but they are scattered singly through the stratum, and have blown up no caves round themselves. Indeed, the clustering of the quadrupeds during their voy- age, appears to be by no means a certain event. If they sunk below the surface, they would sink to different levels; borne on the surface, they might assemble together, but no adherence would take place between them, and upon the slightest impulse they would part again. If the bodies were deposited with their integuments, the bones must be nearly all of them entire. How should they have become broken, enveloped in a soft mass, rendered ad- ditionally elastic by the gases of a putrefying state, and float- ing on a sea which, high above all land, bore them out of the reach of every means of concussion, especially become shivered as are of those of the cave? The force which could thus 1824.) the Formation of the Kirkdale Cave. 55 destroy the bones, had reduced the muscular matter to pulp, and the waters had carried it off, and the cave had had no efficient cause. If the bodies were deposited entire, every bone of each must be forth coming, and its complete skeleton admit of being mounted. Between “the animal remains discovered buried singly in strata of gravel and clay, and those found in multitudinous masses in the cavities of rocks,” there exist the important differences of the former not being in caves, and of the strata in which they occur being fresh-water ones. These remains may consequently be supposed those of animals washed from heights by inundations, and buried in the earthy matter trans- ported with them. Nor can the bones of the cave be -assimilated to the « shells kneaded into the limestone rock of Portland.” For the comparison to hold, the bones must be “ kneaded into the limestone rock” as the shells are, and as are the bones in the Stunsfield slate, which have been placed in it by the sea. Lf the stalactites had been produced by the descent of por- tions of the calcareous pulpy mass yielding to eravity, they would, like the stalactites of lava, formed in this way, bave the texture of the rock. The stalactites of limestone strata are clusters of crystals, which have generated from solution in water. Induration of the calcareous Stratwn. The calcareous paste is supposed by Mr. Penn to have petri- fied by simple drying; and on this ‘supposition mach of the hypothesis concerning the formation of the Cave reposes. Experiments will convince that a paste of calcareous powder and water does not dry to marble, but to whitening. An in- durating faculty must not be aitributed to time, it has it not. Chalk strata cannot be assigned a less age than the rocks of Yorkshire, and they have not dried to stone, nor seem hasten- ing to become such. Each particle of powder is a diminutive pebble, and an inter- vening cement is required to connect it with the neighbouring ones. : Carbonate of lime dissolved in water by means of an excess of acid is the element of agglutination, which nature has in these cases made use of. The acid solvent exhales or becomes saturated, and the neutral salt, ceasing to be soluble, crystal- lizes on the particles of the powder. It is thus that the sands of the Calabrian shores are consoli- dated. The sea water loaded with the calcareous salt, carries it into them, It cannot be by drying since they are wetted 56 Mr. Smithson on Mr. Penn's Theory concerning [Jury, by every wave; and sand wetted with ordinary sea water and dried is not converted into millstone. The great hardness is due to the silicious part. I brought a mass of sand from the sea at Dumbarton, inclos- ing a recent razor shell with its epidermis on it, and fragments of coal, cemented to stone by carbonate of lime, so that the cala- brain process takes place on that coast. In limestones consisting of considerable-sized fragments of shells, the sparry cement which connects them is perfectly evi- dent. It is this cement which appears as regular crystals where cavities occur in the mass too large to have been filled by it. Beds of sediment can by this means become rock at the utmost depths of the ocean, and it is in all probability there that most of them havedoneso. The workings of contiguous volca- nos have supplied the carbonic acid. Oolites have been evidently formed in a sea much loaded with dissolved carbonate of lime, and which on the escape of the dissolving acid has crystallized round floating particles. When the weight of the grains has become such as to occasion their subsidence, they have been cemented together, every thing taking place in all respects as in the case of the pisolites of Carlsbaden. The Kirkdale rock being composed of oolites must have had this origin. Such a formation cannot be assigned to the time of the deluge. Besides the violence of bringing within the compass of a few months, operations whose accomplishment seems to have required centuries of centuries, the necessary conditions must have been wanting. Had not all the volcanos become extin- guished, they could not, and in such a time, have poured forth carbonic acid to saturate the immensity of its waters ; and itis also utterly impossible to believe that tne beings in the ark, already not a little inconvenienced for respiration, could with- stand the suffocating effluvium. Coming of the Animals by Sea. Of the animals having been tropical ones no testimony is offered. The elephant of Siberia bemg now ascertained to have been a very hairy animal may be supposed to have been a northern one, and if there were formerly northern elephants, there may have been northern hyenas and northern tigers. If the bodies were brought by water, no reason appears why they are, with the exception of a few birds, exclusively those of quadrupeds. Reptiles, insects, trees, even fish, for all of them must have perished from the mixture of salt and fresh water, must have entangled in the clusters. As the bodies must have been macerated for about a year in the tropical seas, before the retreat of the waters transported 1824.] the Formation of the Kirkdale Cave. : BY them towards the north, those of the smaller animals, as the water-rats, must have been so completely decayed as to be reduced to the bones. solely, which water would not float. The voyage from the tropics of the balls of album grecum in an entire state, is what will not, under any circumstances, be easy to admit; to suppose it amidst “ turbulent vortices, by which the framework of the animals was shattered, dislocated, fractured within the integuments,” reduced to splinters, is utterly impossible. The entire state of the balls of album gre- cum, and the extremely fractured one of the bones, are totally incompatible on Mr.Penn’s system. And such an ablution would not have leftin these bails a trace of the triple phosphate. But quadrupeds are not the only animals of tropical features found in northern latitudes. Every shell in the strata, the nau- tili, the cornu ammones, the belemnites, the anomia, are now as foreign to the surrounding seas, as are the others to the land. If one then came from afar, both did. What must have been the mass’ and impetuosity of the wave which could buoy a huge oyster, a massive brain stone, from the equator to the British Islands, and at an elevation to depo- sit it on Shotover Hill, or at Kingsweston ? Such waves had tumbled down the mountains of the earth, shivered its islands and its continents, and choked up the bed of the ocean with their ruins. Surely it is a far less difficulty to “ bring the cli- mate to the exuvie, than the exuviz to the climate.” The existence together of the bones of many species does not necessitate the conclusion of the animals having been associates in the cave. If hyenas “ do not always resort to the same den,” neither is it probable do other wild beasts. A succession of inhabitants is admissible. Nor is it required to believe that any of the animals whose bones were found in the cave died there. If hyenas collect bones round their dens, it must be allowed not very improbable that they sometimes, often even, carry them a little further. Alarmed by the roar of a more mighty devourer, or even by that of one of equal strength, it seems natural for them to retreat with their spoil to their last refuge. Why, but to be able to do this, do they bring them near their dens ? The smallness of the cave’s mouth, admitting it to have been always what it now is, would indeed oppose the idea of elephants having walked into it, but no entire skeleton requires the admis- sion of their having done this ; and hyznas who feed on putrid careases, may have found no difficulty in parceling such ; or they may have collected “ the Bushman’s harvest,” or the bones may have been carried into the cave by animals more powerful than hyzenas. If animals as ravenous of bones as hyenas are said to be did not, inany hour of dearth, devour those of the water-rats, 1¢ may 58 Mr. Smithson on Mr, Penn’s Theory concerning [Jury, he because those became tenants of the cave only when the water had expelled the hyenas. It is alike improbable that animals of such contrary habits should dwell together, and that hyzenas should carry so diminutive a prey as a water-rat, to their den to devour it. The small quantity of the album graecum can afford no argu- ment against the animals who produced it having lived in the eave. So brittle a substance could not last long under the trample of numerous animals of such bulk. The water which subsequently entered the cave may have destroyed a part.. The existence of any is astrong circumstance in favour of the suppo- sition of their having lived in the cave, and such as it would scarcely have dared to hope for, in its support. If bones of quadrupeds are found inclosed in no rocks but limestone ones, which it may, however, require more extended observation to establish, the reason may be, that in no other rocks are caverns, in which wild beasts can take shelter, so com- mon. ‘These are likewise the only rocks in whien the formation of stalactite would close the openings, and preserve the bones through a long course of ages, and so as to have reached our times, from the decay and all the accidents to which in an open cave they would be exposed. Of the Deluge. Should every argument which has been adduced to establish that the animals were not brought from remote regions by water, that they lived and died in the countries in which their remains now lie, have appeared insufficient for the purpose, yet, that it is not to the Mosaical flood that their existence, where they now are, is to be referred, two great facts appear to place beyond controversy. One is the total absence in the fossil world of all human remains of every vestige of man himself and of his arts. The magnitude of the chastisement, the order of nature sub- verted to produce it, proclaim the multitudes of the criminal. Human bodies by millions must then have covered the waters ; they must have formed a material part, if not the principal one, of every group, and human bones be now consequently met with everywhere blended with those of animals. Objects of human industry and skill must likewise continually occur among the bones. Of the miserable victims of the disaster numbers would be clothed, and have on their persons articles of the most imperishable materials ; and the dog would retain his collar, the horse his bit and harness, the ox his yoke. To men who wrought iron and bronze, who manufactured harps and organs, these things must have been familiar. But more ; embalmed within the substance of the diluvian mud, entire cities, with their monuments, with a great part of 1824.] the Formation of the Kirkdale Cave. 59 their inhabitants, with an infinity of things to their use, would remain. Every limestone quarry should daily present us with some of these most precious of all antiquities, before which those of Italy and Egypt would shrink to nothing. How greatly must we regret that this is not the case, that we must relinquish the delightful hope of some day finding in the body of a calcareous mountain, the city of Enoch built by Cain, at the very origin of the world, with what awful sentiments had not present generations contemplated objects which once had been looked upon by eyes which had seen the divinity ! The other great fact which forcibly militates against the dilu- vian hypothesis is, that the fossil animals are not those which existed at the time of the deluge. The diluvian species must have been the same as the present. The multifarious wonders of the ark had for sole object their preservation; while of the fossil kinds, not perhaps one, or quadruped, or bird, or fish, or shell, or insect, or plant, is now alive. “« Amazing proofs of inundations at high levels ” are appealed to. Had they being, of the deluge they could at most speak but to the existence; on its influence in the contested cases, they would be silent; but it appears that this stupendous prodigy, s¢ Tike the baseless fabric of a vision, Left not a wreck behind,”’ Of the occurrence of marine depositions at great altitudes, the elevation of the stratum by volcanic efforts, furnishes a far more easy solution than the elevation of the sea, as it refers the phe- nomenon to a natural cause, and does not require the immediate interposition of the divine hand; and the ruptured state and erect position of the strata on all these occasions, testify strongly in favour of the simpler supposition. To collate the revered volume with the great book of nature, and show in their agreement one author to both, was an under- taking worthy of the union of piety and science. If the result has not been what was anticipated ; if we look in vain over the face of our globe for those mighty impressions of an universal deluge, which reason tells us that it must have produced and left behind itself, to some cause as out of the natural course of things as was that event, must this doubtless be attributed. By his entering into a covenant with man and brute animals, -and having for ever “set his bow in the cloud,” as a token that the direful scene should never be renewed, the Creator appears to have repined at the severity of his justice. The spectacle of a desolated world,—of fertility laid waste,-— of the painful works of industry and genius overthrown,—of infantine innocence involved in indiscriminate misery with the hardened offender,—of brute nature whose want of reason pre- cluded it from the possibility of all offence, made share in the 60 Analyses of Books: (Jury, forfeit of human depravity, may be supposed to have touclied his heart. j Under the impression of these paternal feelings, to obliterate every trace of the dreadful scourge, remove every remnant of the frightful havoc, seem the natural effects of his benevolence and power. As a lesson to the taces which were to issue from the loins of the few who had been spared,—races which were to be wicked indeed as those which had preceded them, but which were promised exemption from a like punishment, to have pre- served any memento of them would have been useless. To a mitacle then which swept away all that could recall that day of death when “the windows of heaven were opened” upon mankind, must we refer what no natural means are adequate to explain. ? Articite XII. ANALYSES OF Books. An Epitome of Chemistry, wherein the Principles of the Science are illustrated in 100 Entertaining and Instructive Expert- ments, §c. &c. By the Rev. John Topham, MA. (of St. John’s College, Cambridge) Head Master of Bromsgrove Grammar School, Worcestershire. Second Edition. 24mo, pp. 134. Contrary to the expectations we had formed when we first saw this publication, it has (according to the title page at least) reached a second edition; we consider it, therefore, proper to exhibit its true nature to the public, and to warn them of the numerous errors which it contains :—errors greater in number and importance than in any work of the same size that ever appeared on the subject of which it treats. We shall not pretend to go minutely through the book ; a few passages, taken almost at random, will be sufficient to show the nature of the work, and that the author, without intending to be original, is so gteatly in error, that he does not possess even the slender requisites for a copyist. With respect, first, to chemical action, it is stated, in p. 4,that “ chemical action will not take place between two bodies, except one of them be in a fluid state, or at least contain water.” Now this is not the fact; ttumerots examples might be given of the contrary, but one will suffice, viz. the mutual action of lime and muriate of ammonia. In p. 5, it is asserted that “if two bodies, g and y, unite in the proportion of 4 to 6, then these numbers express the weight of their atoms.” This again is an error; oxygen and phosphorus unite in the proportion of 4 to 6, but these numbers do not express the weights of their atoms; they only show that phosphorus combines with two-thirds of its 1824,] Rev. J. Topham’s Epitome of Chemistry. 61 weight of oxygen, but the weight of the atoms depends upon that of the standard assumed: thus the weight of an atom of hydrogen being 1, that of oxygen is 8, and phosphorus 12, but ae atom of hydrogen being 0°125, oxygen is 1, and phosphorus ib. *“ When combination takes place between two bodies in various proportions, the numbers indicating the greater are exact simple multiples of that denoting the least. Thus 100 parts of carbon unite with 1321, or 265 parts of oxygen, and no other. Again, 100 parts of sulphur unite with 50, or 100, or 150 parts of oxygen ; and in the intermediate ones no combination ensues.” Now it happens that the greatest proportion is sometimes not a multiple, but one-half more than the least ; this occurs with respect to iron, of which 28 parts unite with 8 of oxygen to form protoxide, and with 12 to form the peroxide. Again, the exact quantity of oxygen with which 100 of carbon unite are 133 to form oxide of carbon and 266 to form carbonic acid, but there is an intermediate compound, namely, oxalic acid, composed of 100 carbon and 200 oxygen. Once more; 10) of sulphur unite with 125 of oxygen to form hyposulphuric acid, as well as with the three proportions above stated, In p. 12 we have a marvellously easy method of making sul- phuric acid ; sulphur “ by combustion in atmospheric air over water, unites with oxygen, and forms sulphuric acid.” How foolish then have our manufacturers been in using nitre at a vast expense! We must, however, I believe, for sudphuric read sz(- phurous, Iodine appears also to have undergone a wonderful change of properties ; according to Mr. Topham, it “ is abundantly ab- sorbed by water;” the fact is, that water absorbs about 1-7000th of its weight. In the chapter on the alkalies, potash, soda, and ammonia are mentioned; and after incorrectly. stating that the last “next to hydrogen gas, is the lightest known ponderable body,” we are informed, that “ the other alkalies are lithina, delphine, brucine, vauqueline,” and then we are instructed that “the bases of the other alkalies [meaning the four last named], except vauqueline (which is of vegetable origin) have also been formed into amalgams with mercury, and are found to be metallic.” From this we might conclude that delphia and brucia are not of vegetable origin, and that the seeds of stavesacre, and the bark of the brucia antidysenterica have been “ found to be metallic.” The sentence which we have last quoted is followed by “oxygen, therefore, in one proportion is the cause of alkalinity ; in another (as will be seen) of oxidation ; and in a ¢hird of acidity.” It is difficult to conceive how so much error could have been crammed into sosmall a space. Ifthese statements were true, then we may take any substance which is capable of uniting with oxygen; let it be hydrogen, sulphur, or potassium, and by combining them in 62 Analyses of Books. | (Jury, different proportions produce a mere oxide, an alkali, or an acid, with the same base. Mr. Topham will find that he has incor- rectly stated with respect to different proportions of oxygen, what is true only with regard to different bases. This erroneous view of the case is also contained in the chapter on oxides, in which it is stated that “ any simple substance, in union with a less quantity of oxygen than is necessary for the formation of an acid, is termed an oxide.” Now acidity does not depend upon the quantity of oxygen, but upon the nature of the base which unites with it. Six parts of carbon combined with 16 of oxygen form an acid, but 6 parts of hydrogen combine with 48 of oxygen to form water. In the next chapter we again meet with the erro- neous statement that sulphuric acid is formed by the combustion of sulphur over water; and sulphurous acid is said to be “ con- stituted of 1 atom sulphur and 2 of oxygen in 100.” We would inquire whether it is not so constituted in 10, 100, or 1000 parts? or whether its atomic constitution is altered by the quantity sub- jected to analysis, so that what is true of two portions of 50 parts each added together would not be true of 100 parts ? Nitric acid is said to be a compound of one atom of nitrogen and two of oxygen, instead of five of oxygen; but carbonic acid is one of the most extraordinary we have ever met with: “it is widely diffused through nature, being combined with chalk, limestone, gypsum, magnesia, &c.” Of these four statements, one only is correct; chalk and limestone are not combined with carbonic acid, they consist of lime combined with it, and gypsum is neither combined with, nor contains carbonic acid; we need hardly say, that it consists of sulphuric acid and lime. In speaking of nitrous oxide, it is stated to consist of “ two atoms of nitrogen and one of oxygen.” We suspect that cour author has mistaken volumes for atoms; for this gas, although composed of two volumes of nitrogen and one volume .of oxygen gas, is generally allowed to consist of only one atom of each. It appears from Exp. 4, that our author does not know that nitric oxide and nitrous gas are different names for the same elastic fluid ; for he says at p. 64, nitric oxide on coming into contact with atmospheric air receives a further portion of oxygen, and becomes nitrous gas. We have neither time nor inclination to pursue our observa- tions upon this work any further ; and after what we have stated it would be superfluous to offer any additional opinion respecting it; but we cannot refrain from expressing our surprise, that a gentleman who must have distinguished himself in order to have acquired the degree of Master of Arts, should so far have for- gotten what was due to his own reputation and to public utility, as to venture to write a book upon a subject, his ignorance of which he must have felt, and all conversant with chemistry must discover.—(P.) 1824.] Proceedings of Philosophical Societies. 63 Articite XIII. Proceedings of Philosophical Societies. ROYAL SOCIETY. May 27.—The reading of Mr. Abrahams’ paper on Magne- tism was concluded ; and a paper was read, On the Direction of the Eyes in Portrait Painting; by W. H. Wollaston, MD. VPRS. June 3.— Lemon, Esq. was admitted a Fellow of the Society; the name of Charles Macintosh, Esq. ordered to be inserted in its printed lists; and a paper was read, “On the Generation of Fishes ; by J. L. Prevost, MD.” The Society then adjourned to June 17, in consequence of the ensuing holidays. June 17.— Edgeworth, Esq. was admitted a Fellow of the Society, the name of Major Charles Hamilton Smith, ordered to be inserted in its printed lists ; and the following papers were. read, several of them in an abridged form, On the Organs of Generation of the Axolotl, and of other: Protei; by Sir E. Home, Bart. VPRS. On the Effects of Temperature on Magnetism and on the diurnal Variation of the Needle; by 8. H. Christie, Esq. MA. = communicated by the President. On the Preservation of the Copper Sheathing of Ships, andi on some Chemical Facts connected with it; by the President. On the Application of Deebereiner’s new Discovery to Eudio- metry ; by William Henry, MD. FRS. The Society then adjourmmed, over the long vacation, to meet again on the 18th of November next. LINNEAN SOCIETY. May 4.—M. G, St. Hilaire was elected a Foreign Member. A notice from Mr. Wood was read respecting the Golde Oriole, Oriolus Galbula, shot on the 26th of April, flying in: company with some Blackbirds, at Aldershot in Hampshire, The reading was continued of Mr. Vigors’s papers on the: Natural Affinities of Birds; and of the Catalogue of Norfolk: and Suffolk Birds, by the Rev. Messrs. Sheppard and Whitear. May 24.—On this day, being the birth-day of Linneus, the: Anniversary of the Society was held at one o’clock, in con- formity with the Charter, the Right Rev. the Lord Bishop of Carlisle, Vice President, in the Chair. The following gentlemen were re-elected Officers : Sir James Edward Smith, President ; Edward Forster, Esq. Treasurer ; Alexander Mac Leay, Esq. Secretary ; Mr. Richard Taylor, Assistant Secretary. 64 Proceedings of Philosophical Societies. [Ju.y, The following were elected to be of the Council for the en- suing year :—Edward Barnard, Esq.; H. T. Colebrooke, Esq. ; Major-General T. Hardwicke ; Daniel Moore, Esq.; and Philip B. Webb, Esq. An extensive and interesting series of the various species of Rhubarb from Chelsea Garden was exhibited by Mr. Anderson. The Anniversary Dinner of the Society took place at Free- masons’ Tavern, and a considerable number of the Fellows, in- cluding many from distant parts of the kingdom, participated in the pleasure of this meeting, which was alloyed only by the absence, owing to indisposition, of their highly esteemed Pre- sident, whose excellent qualities, great attainments, and invalu- able labours for the promotion of science, have long endeared him to those who know him, and especially to the lovers of Natural History. The chair was filled on this occasion by the venerable Prelate, who from the first foundation of the So- ciety has been one of its most zealous supporters. June 1.—The reading of Mr. Vigors’s paper was concluded ; and that of Messrs. Sheppard and Whitear’s Catalogue conti- nued. June 15.—The meeting of this evening, which was an ex- tremely numerous one, was honoured by the presence of His Royal Highness the Prince of Saxe-Cobourg, and several other personages of distinction. The reading was commenced of a paper, On the Structure of the Tunicata; by W.S. Mac Leay, Esq. MA. FLS. and the Society then adjourned, over the summer recess, to meet again on the 2d of November next. ASTRONOMICAL SOCIETY. May 14.—The whole of this sitting of the Society was occu- pied by the reading of the conclusion of Mr, Baily’s paper On the Method of detérmining the Difference of Meridians, by the Culmination of the Moon; this paper having been commenced at the last meeting in April. The author, after briefly alluding to the nautical methods of determining the longitude, including those by means of chro- nometers, adverted to five distinct astronomical methods which have been pursued, viz. lst, By the eclipses of Jupiter’s satel- lites. 2dly, By eclipses of the moon. 3dly, By eclipses of the sun, 4thly, By occultations of the fixed stars. And Sthly, By meridional transits of the moon, The first three of these, by reason of their inirequency and obvious sources of inaccu- racy, are of very limited utility; while the fourth method is rendered uncertain from its involving a doubtful datum, the com- pression of the earth, as well as other difficulties which the au- thor pointed out, He then proceeded to point out that the fifth method was greatly superior to any of the others, in which 1824.) Geological Society. 65 opinion he was supported by the testimony of Dr. Maskelyne, Bernoulli, and many eminent astronomers who were quoted, Notwithstanding its high recommendations, this method has not been successfully adopted in practice, and has even ted to some awkward anomalies, on account of its having been customary to take the moon’s centre reduced to the meridian, and to com- pare it with the apparent places of stars passing the meridian about the same time in any parallel of declination. The newly proposed method consists in merely observing with a transit instrument, the differences of right ascension between the border of the moon, and certain fixed stars previously agreed upon, restricting the observations to such stars as differ very little in declination from the moon, and denominated moon culminating stars. The attention of astronomers has been called to this method by M. Nicolai, of Manheim, in several numbers of Schumacher’s Nachrichten. 1t is quite independent of the errors of the Lunar Tables (except so far as the moon’s horary motion in AR is concerned). It does not involve the quantity of the earth’s compression. It does not require a correct knowledge of the position of the star observed, nor does an error of a few seconds in the clock sensibly affect the result. Hence much trouble is avoided, many causes of error pre- cluded ; besides all which, the method 1s unzversal. GEOLOGICAL SOCIETY. May 21.—The reading of the paper “ On the Geology of the Ponza Islands in the Mediterranean; ” by George Poulett Scrope, Esq. MGS. was concluded. The Ponza Islands lie off the coast of Italy, opposite Terra- cina and Gaieta. They consist of Ponza (anciently Pandataria), Palmarola, and some islets; Ventotiene and San Stefano con- nect them with Ischia. The harbour of Ponza is excellent. Dolomieu’s Memoire sur les Isles Ponces excited curiosity, but is too general to satisfy it. These islands are composed of rocks, of the Trachytic series, and presenting fine sections along their coasts, enabled the author to clear up many doubts and errors which the mere investigations of inland localities have caused to be affixed to this formation. The Isle of Ponza is long and very narrow, and is eroded by the sea into deep concavities. Harder masses left along its shores show that it ence was broader, and protruding ledges mark its former connexion with Quannone and La Gabbia. Prismatic trachyte, variously coloured and disposed, forms the ossature of the island. It 1s constantly accompanied by, and alternates with, a semi-vitreous trachytic conglomerate, formed of minute pulverulent matter enclosing fragments of trachyte. The prismatic trachyte seems to have been forcibly injected through the conglomerate, and wherever it touches the latter New Series, vou. Vill. F 66 Proceedings of Philosophical Societies. [Juny, its earthy base is converted from two to thirty feet deep into a pitchstone-porphyry ; sometimes it becomes a pearlstone, at others encloses a true obsidian. These rocks are connected with a silicious trachyte, resembling in appearance the silicious buhrstone of Paris. Resting on the semi-vitreous trachyte and forming the base of the Montagna della Guardia, is a rock 300 feet thick, which the author distinguishes mineralogically from common trachyte, and proposes to call greystone. In Jannone the trachyte overlies a limestone, which Brocchi describes as transition limestone ; at the point of contact this latter becomes dolomite. Having described the whole of this group, the author terminates his paper by connecting their eological structure with that of the neighbouring continent of taly. cones was read, entitled, “ Notes accompanying Specimens collected on a Journey through Part of Persia and the Russian Tartaries ;” by James B. Fraser, Esq. MGS. June 4.—A paper was read, entitled, “ Description accom- panying a Collection of Specimens made on a Journey through the Province of Khorosan in Persia;” by J. B. Fraser, Esq. GS, On quitting Teheran, the road passed by the roots of the chain of Elburz, through the pass Gurdunee, Sirdara to Sem- noon and Shahrood, over gravelly hills, having to the south a salt desert, and appearances of salt on all sides ; thence by Mey Omood, Abbassabad, Muzenoon, and Subzawar to Nisha- pore, about 40 miles west of which place are found the cele- brated torquoise mines, which are worked along the sides and ridges of a narrow valley. The principal mine is called Abdool Rezakee. The calaite is found pervading a soft yellow stone and a mouldering reddish rock, as also a rock of much firmer texture resembling quartz rock of a grey colour with reddish streaks, and containing specular iron. A conglomerate rock occurs in the vicinity, The mineral is found sometimes in veins, sometimes mammillated in fissures, and at other times irregu- larly dispersed through the rock. The author describes all the mines actually worked; they are the property of the crown, and were valued, when Mr, Fraser visited them, at the annual rent of 2000 tomauns of Khorosan, or about 3500/. sterling, and are farmed to the highest bidder. At Derroad, 25 miles from Nishapore, the primitive rocks of Elburz appeared sunilar to those seen in the lofty range between Ispahan and Cashan. A paper was then read, entitled, ‘ Geological Observations on the Sea Cliffs at Hastings, with some Remarks on the Beds immediately below the Chalk ;” by T. Webster, Esq. Sec. GS. This paper commenced with a geographical description of the cliffs on each side of the town of Hastings, from the White Rock on the west to the end of Fairlee cliff on the east, which 1824.} Geological Society. 67 form a very instructive natural section of an elevated tract in Sussex, surrounded by, and coming out from under, the clay of the Wealds. These cliffs consist of alternating beds of sandstone, shale, and clay, more or less charged with oxide of iron, and carbon- ized vegetable matter. The iron is most abundant in the lower part, where there are beds of two or three inches thick of rich argillaceous iron ore that were profitably worked before the fuel of this part of the country became scarce. The middle beds of the cliff have much less iron, the greatest part consisting of very white friable sandstone. In the upper part of the series, there are many large blocks of a grey calci- ferous sandstone, the surfaces of which exhibit a mamillated structure: and this rock may be considered as a variety of the chaux carbonatée quartzifére of Hatiy, having much analogy with the crystallized sandstone of Fontainebleau. The mamillated ap- pearance is very well seen at the white rock, and has (though erroneously) been usually attributed to the action of the sea upon the fallen blocks. The fossils, in the cliffs of Hastings, are not numerous ; the shells being confined to two or three species of small bivalves, and a univalve resembling that in the Petworth marble. Thin layers of lignite are frequent, and fragments of a very singular silicified wood of the monocotyledon kind, the cavities of which are filled with minute transparent crystals of quartz. Bones of large Saurian animals, and of birds, also occur, though rarely, together with scales of fish. The author observed, that the grey calciferous rock has not hitherto been noticed in any part of the formations between the chalk and the Purbeck, except in this district; and from its not being co-extensive with the rest of the ferruginous sand series, and the want of continuity and correspondence in many of the beds, he took occasion to remark, that it may be fre- quently more correct to consider the subdivisions of some formations rather as irregularly lenticular than as tabular masses. A June 18.—A paper was read entitled “ Notes on Part of the opposite Coasts of the English Channel, from Deal to Brighton, ry: wie Calais to Treport;’ by Wm. Henry Fitton, MD. GS. This paper was accompanied by a connected series of views or elevations of the coast, drawn by Mr. Webster, from the place where the chalk rises near Calais, to where, after being cut off near Blanc Nez, the chalk again appears upon the shore near Treport; and, on the English side, from the rise of the chalk near Deal, to where it sinks at Brighton. The author expresses his acknowledgments to the Baron Cuvier, through whom he obtained permission from the French authorities to ¥ 2 68 Scientific Notices—Chemistry. (Juny, pass along the coast by sea, and experienced everywhere the greatest attention from the officers of the French customs. The paper briefly describes the leading geological features of the coast, reciting the partial descriptions already published, and referring, for an account of the cliffs near Hastings, to a me- moir by Mr. Webster, read at the last meeting of the Geolo- ee Society ; and for a detail of the beds which form the cliffs rom Gris Nez to Equihen, to an account of the lower Boulon- nois to be read at a future meeting. From Equihen to the mouth of the Somme, the coast is altogether occupied by dunes of sand, the sand hills being, in some places, especially in the vicinity of Etaples, more than 100 feet in height. These hills are, in general, somewhat crescent shaped, the back of the crescent being turned towards the prevailing wind, and the slope on the lee side much more rapid than the opposite one. The immediate base of the dunes seems to be peat, which is found both on the land side of them, and without, just on the verge of the sea, and in some places, below the level of high water: but no rocks have yet been discovered along the coast beneath the dunes. A list of heights obtained by the barometer is subjoined to this paper, and some detached sketches are an- vorpal to it of interesting geological appearances on the French shore. ArTICLE XIV. SCIENTIFIC NOTICES. CHEMISTRY. 1. On the Nature of the free Acid ejected from the Human Stomach in Dyspepsia. Our readers know from the notice of the proceedings of the Royal Society in the Annals of Philosophy (Feb. 1824), that in December last, Dr. Prout read a paper before that learned body, the object of which was to prove, that the acid usually found to exist in the stomach of animals, during the digestive process, is the muriatic. An acquaintance of mine, who occa- sionally suffers severely from dyspepsia, and was somewhat scep- tical as to Dr. Prout’s conclusions, lately requested me to exa- mine the fluid ejected from his stomach during a violent dyspep- tic paroxysm the day before, with the view of ascertaining the nature of the free acid it contained. The fluid which had been thrown from the stomach in the morning, fasting, when filtered, was perfectly clear, and nearly colourless ; it gave a decided red tint to litmus paper. I dis- tilled about six ounces of it almost to dryness, at a gentle heat, receiving the product in three separate and nearly equal portions. 1824.} Scientific Notices—Chemistry. 69 One-half of each portion was treated with nitrate of silver. The first had no effect on litmus paper, and scarcely gave the slight- est cloud with the test. The second became slightly cloudy by the test, but was equally without any action on the blue paper. The third portion reddened the paper strongly, and produced an abundant dense cloud, when I dropped into it the nitrate of silver, and a pretty copious precipitate collected at the bottom of the tube. The remaining half of the third portion was evapo- rated by a gentle heat to about halfa fluid drachm. The preci- pitate which a drop of it, placed on a slip of glass, occasioned with a drop of nitrate of silver, was insoluble in nitric acid, and perfectly soluble in ammonia. Another drop, similarly treated with muriate of barytes, gave no precipitate, nor cloud. The remainder was neutralized with pure ammonia, further evapo- rated, and poured on a slip of glass; when it afforded a multi- tude of well-defined crystals of muriate of ammonia. The precipitate from the first half of the same portion by nitrate of silver, being collected, washed, and dried, fused on a slip of platina foil before the blowpipe into horn silver. The presence of free muriatic acid in the ejected fluid, and consequently the accuracy of Dr. Prout’s conclusions, seem to be fully confirmed by the preceding experiments. J.G.C 2. Pyroxylic and Pyroacetic Spirits. In a paper read before the Society of Physics and Natural History of Geneva, on the 16th Oct. 1823, MM. Macaire and Marcet have given a description and analysis of two fluids, ana- logous in many of their properties to alcohol, particularly in being pp like it, of forming ethers when acted upon by acids. Pyroxylic spirit, the first of these, is obtained during the rectification of pyrolignous acid; the second was described long ago by M. Chenevix under the name of pyroacetic spirit, and may be prepared by subjecting the greater number of the ace- tates to distillation. Pyroxylic spirit is colourless and transparent. Its smell is strong, pungent, and ethereal, and has a strong resemblance to that of ants. Its taste is strung, hot, and slightly pungent, leaving a distinct impression of the flavour of oil of peppermint. Its specific gravity, after having been distilled off dry muriate of lime, is 0°828, It boils at 150°. It reddens litmus paper very slightly ; but this effect is probably produced by a minute resi- due of acetic acid ; for when the spirit is distilled off litharge, a small portion of the oxide is rendered soluble in water. The dissolved salt is not precipitated by barytes, nor by nitrate of silver, and it contains no nitric acid: it appears, therefore, to be an acetate.. When heated, the spirit burns with a fine blue flame, without leaving any residue. Alcohol dissolves. it in % 73) Scientific Notices—Chemistry. [Juny, every proportion, and the addition of water renders the solution ’ in and the spirit gradually ascends to the surface. ater alone converts the spirit into a semi-opaque fluid, resem- bling an emulsion, which persists for an indefinite length of time in this state, without a separation of the two fluids taking place, and without becoming transparent. It is equally insoluble in oil of turpentine. Camphor dissolves in it with great facility. Olive oil does not dissolve in it, either when cold or hot. Potash dissolves in it without producing any sensible alteration, except causing it to assume a yellowish tinge, and producing a slight elevation of temperature. ‘Pyroxylic spirit, when mixed with its volume of sulphuric ‘acid, may be distilled over unaltered ; but if thrice that quantity of acid be employed, it blackens, and is decomposed, and a small quantity of a gas is evolved, which is a mixture of hydru- ret of carbon and hydrogen. The gas contains no olefiant gas ; for it burns with a feeble blue-coloured flame, and sustains no speedy diminution of volume when mixed with chlorine. When distilled with its volume of nitric acid, there passes over an ethereal fluid, together with a considerable quantity of nitrous vapours. This new fluid has an agreeable odour, reddens litmus paper even after having been distilled off litharge, burns with a dull heavy flame, and dissolves in all proportions in water and alcohol, communicating to them a sweet taste, like that of sugar. It differs, therefore, in all its properties from nitric ether. The spirit is not altered by being exposed to a current of nitrous gas; neither does it yield an ether when repeatedly dis- tilled with its volume of muriatic acid. A current of chlorine sent through a quantity of the spirit, at first imparts to it a deep-yellow colour; but after the process has gone on for a few minutes, the liquid suddenly becomes again colourless. By this treatment, its volume augments one- twelfth. The new fluid thus obtained is colourless and trans- parent, and smokes with ammonia. It has a peculiar and very pungent smell, and excites tears. Its taste is hot, leaving an impression exactly similar to that of horse-radish. After distil- lation off litharge, its speciiic gravity is 0°889. It burns with a blue flame and a white smoke, which gives thick vapours with ammonia. Water andalcohol dissolve it. It is precipitated by nitrate of silver; and it becomes more acid, and acquires a slight yellowish tinge by exposure for some time to the air and light ; but by distillation off a little litharge, it may be restored to its original purity. These two liquids, formed by the action of nitric acid and chlorine, appear, therefore, to be ethers, endowed with peculiar properties ; and the mode in which the pyroxylic spirit is de- 1824.] Scientific Notices—Chemistry. 71 composed by acids appears also to be completely analogous with the decomposition of alcohol, in the formation of those 9p to which the name of ether has been already appro- riated. : Pyroacetic spirit is strikingly distinguished from the pyroxylic in many of its most important characters. Its specific gravity is inferior, being only 0°786. Its taste and smell are also differ- ent; and it burns with an intense white flame, very different from the blue flame of pyroxylic spirit. It is also completely soluble in oil of turpentine. Sulphuric acid neither blackens it, nor renders it turbid, but communicates to it a fine orange-yellow colour; and the mix- ture continues transparent, even after the application of heat. When distilled along with muriatic acid, a volatile fluid passes over having the odour of that acid; but this is completely removed by re-distilling it off potash. A current of chlorine, sent through the pyroacetic spirit, communicates to it a slightly-yellowish shade, but without pre- senting the subsequent phenomenon of a sudden discoloration. The resulting fluid has a suffocating odour, somewhat similar to that of the chloro-pyroxylic ether, but stronger. After a few instants, it separates into two distinct fluids; the one, thick, heavy, oily, and transparent ; the other, lighter, and slightly opalescent. The latter burns with a light flame, of a bluish colour, and leaves an abundant acid residue. It dissolves in water, and imparts to it a hot taste, followed by a sensation of sweetness ; but it does yield a trace of the horse-radish flavour, which characterises the ether formed by chlorine and the pyr- oxylic spirit. The oily fluid, after a few days, acquires a slight yellowish colour, and burns with a thick flame of a deep-green colour, emitting suffocating fumes, which contain abundance of muria- tic acid. It is soluble in alcohol, but insoluble in water. When poured into the latter, it subsides to the bottom in separate drops. oth of these spirits were analyzed, by volatilizing a known weight of them through red-hot oxide of copper. The pyroxylic spirit, decomposed in this way, was found to consist of SE AEINOTN GAS 60) «ia altel Aid/adaelaeeBiis.eos-nmxeie Do ERED wo 5.0 sie pla doh ih incknrose «nn Hydrogen isisicissadssvorseseces. 916 100-00 Or very nearly, of 6 atoms of carbon, 4 of oxygen, and 7 of hydrogen. The pyroacetic spirit was found to consist of 72 Scientific Notices—Mineralogy. [Juny, Carbon.. eeoeoeveveetesneeee eee eeeeae ee 55:30 Oxygen. eeeoveeeveveeveereevr ee eeeeeeee 36°50 Hydrogen ...seveccsecvescvscsnee 8°20 100:00 Or very nearly, of 4 atoms of carbon, 2 of oxygen, and 3 of hydrogen.—( Bibliotheque Universelle, Oct. 1823.) 3. Argillaceous Iron Ore. The analysis of this ore, given in the last number of the Annals, was incorrectly stated. The reader will perceive that the quan- tities of lime and carbonaceous matter, having been obtained from 200 grains of the ore, should have been divided by 2; and a small quantity of alumina separated from the precipitated oxide of iron being added, the composition will be nearly as follows, and as it will be found stated in Phillips’s Mineralogy, Pp: 237, viz. Protoxide of iron, with a trace of man- Panes to's. Hse wee J eiveceeee ve 43°26 Carbonic acid... sc. ee ees 8 HS SU SSG Silica and alumina ...... Sar Sarre 20°78 Carbonaceous matter ...... Set, eat ayy "OF AGM R ET ete Vee. & eee ee UE UD Bie Momture 1.60 ole. oa Ne SR ST POU SORE. Sree Se I, BE RS Me aes 1:10 100:00 R. P. 4. Aberthaw Limestone. This limestone, which is highly esteemed for the goodness of the lime which it yields, I have found to consist of Carbonate of lime. ........ ae Ree BE? Alumina) ss... sake otdialevcnkse 31s. Saeiaiena 20 Slew isd. vol natl'ey Seis eidie de evo ldveetn ee aU Carbohaceous matter oso cee we wre Monstirés:; 04 degli ads ects SOS Oxide -ofmon-ic As Fo Orbe k Hawes 2 0:66 100:00 R. P. MINERALOGY. , 5. Composition of Tourmaline. M. Gmelin, who has devoted a good deal of attention to the analysis of this mineral, deduces the following conclusions from his researches. All the tourmalines hitherto examined by him contain from two to six per cent. of boracic acid, which appears to be quite an essential ingredient. All of them contain also 1824.] Scientific Notices—Mineralogy. 73 two alkaline bases, which are a mixture in some cases of potash and soda, in others of potash and lithia. Magnesia also exists in mostspecimens, but does not appear to be so essential an ingredient as the preceding. Oxide of iron is sometimes pre- sent in a very large proportion; sometimes it is altogether wanting. The rubellite, from Rozena,in Mahren, consists, according to his analysis, of DETTE OR TT: IR eae ee PP ME 9 yc Es BETIS a og a aise Aan ein a0 0 oo aint » 42°127 Alumina ......--eeeees ee eeeecees 30°430 Oxide of manganese....+..eeeee- 6320 DA in adie binvase-aini tao nmin ok €re wee LEU 1 CLS | SPE ar IAD 2-405 Lithia. «over ccccscecncences seco 2043 Volatile matter ..ceeseseees roi ats 97-582 This mineral does not contain a trace ofsoda. The substance which Klaproth and Bucholz mistook for that alkali was in fact a mixture of boracic acid, potash, and lithia. The schorl from Eibenstock, in Saxony, which was more recently analyzed by Klaproth, consists, according to Gmelin, of ESOP ACG CAG i 6 doe pidie d 4-0 we aa a-ak oe . 1890 EE tre niaican ofcist che ame ca ns eres PUOATIEE Visa’ o cis ss sine «op di tras bowie 38°235 PTOURIde BY WON sar sie Hes are siice ora hs 23°857 Soda with potash........... Sariats 3175 Lime with traces of magnesia ...,.. 0°857 101-062 The tourmalines examined by him were six in number, and were all from different localities.—(Schweigger’s Journal, vol. XXXvill. p. 514.) 6. Petalite. Dr. Bigsby has discovered Petalite on the north shore of lake Ontario, on the beach in front of York, the capital of Upper Canada. It is a rolled mass weighing about a ton. The mineral has been examined by Dr. Troost; it occurs in crys- taline masses, of a greyish white colour, with a tinge of green, and resembles some varieties of Tremolite, for which indeed it was first taken.—(See Jour. Acad. Nat. Sciences, No.8, vol. 3.) 7. New Localities of American Minerals. By John W. Webster, MD. MGS. Lond. Zircon and Green Felspar of Beverly (Mass). In a former 74 Scientific Notices— Mineralogy. [Juxy, number of this Journal, page 390, we have noticed the dis- covery of green felspar at Beverly in this state. The speci- mens first found were met with in a stone wall; it was ascer- tained that the materials for the construction of the wall were taken from the common, or parade ground of Beverly, many years ago. Application was made to the proper authorities for permission to open the ground and make a thorough examina- tion. The result of this undertaking has been highly satisfac- tory. The green felspar has been found in narrow veins tra- versing sienite, accompanied with crystals of zircon, and some other substances, the nature of which has not as yet been satis- factorily determined. The crystals of zircon have an amber-brown colour, a resin- ous and oily lustre, with a fracture somewhat conchoidal and foliated. The cleavages, in some of the crystals, are tolerably distinct and indicate the octohedral primitive form. A few per- fect octohedral crystals have been found. The largest crystal in my possession, weighs 30 grains -3,ths, and its specific gravity is 4:06 ; it is a four-sided prism termi- nated by a four-sided pyramid; the terminal planes being set upon the lateral edges of the prism. With the reflective goniometer I find the angle of inclination 130° 12’. The angles scratch rock crystal. The hornblend and felspar which accompany these interest- ing substances, very much resemble those of the zircon sienite cf Von Buch, with a specimen of which in my collection I have carefully compared it. The structure of this rock, and its geo- logical connexions, are highly interesting. The following is Von Buch’s description of the Norway zircon sienite. It is strongly distinguished from every porphyry by the magnificent, coarse granular, and sometimes large granular felspar, partly of a pearl-grey, and partly of a red colour, which always strongly characterises the blocks by its high degree of lustre. It is equally distinct from granite, sienite, or other similar granular stones, by the preponderance of thefelspar. All the other ingre- dients seem to be sunk in this as a basis, and they often appear only occasionally ; but hornblend is never wanting, and this hornblend is generally pretty characteristic and distinct ; long black crystals, which possess a double foliated fracture by way of discrimination from mica—folia of mica also make their ap- pearance but very rarely; and quartz shows itself in small grains, so as not to be altogether missed. It appears, in gene- ral, accidentally in the composition, and we search through whole hills without finding it again. Wherever the grains of the felspar meet, there remains almost always a small angular cavity into which crystals project. Among these, are the crys- tals of zircon, which give name to the rock. Epidote is asso- ciated with them in fine needles. 1824.] Scientific Notices— Miscellaneous. 75 In the rock at Beverly, there is a great tendency of the com- ponent parts to assume regular crystalline forms, and a few per- fect crystals of green felspar have been obtained. Phosphate of Lime.—I have lately found a few pretty distinct crystals of phosphate of lime near the village of Stow, in this state. The crystals are disseminated in rolled masses of a coarse grained granite. They are portions of hexedral prisms, of a greenish-white colour. The fracture in the direction parallel to the base of the prism is distinctly foliated, and the powder phosphoresces on burning coals. The same granite contains well defined crystals of beryl, and here and there a small crystal of tourmaline. Andalusite.—This mineral I found in a rolled mass of white quartz, in small imperfect four-sided prisms, near Lancaster. The colour is a reddish-brown. Spodumen.—A notice of this mineral has lately been published in the Journal of the Academy of Nat. Sci. of Philadelphia. I have visited the locality at Sterling, and find it very abundant. The principal rock in which it occurs is a compound of quartz, mica, and spodumen, weighing probably about thirty tons. It may be called spodumen rock. Cleavelandite occurs in small quantity at Sterling (Boston Journ. of Philos. and the Arts, No. 6, May, 1824.) MiscELLANEOUS. 8. On the Cause of the Rotatory Motion of Camphor in Water. (To the Editor of the Annals of Philosophy.) SIR, If your Cambridge correspondent E. A. (see Annals of last month) will look at page 51 of the first volume ef Nicholson’s Journal, 8vo. series, he will find that he is mistaken in supposing that no cause has been hitherto assigned for the rotatory motion of a particle of camphor when placed on the surface of water. Several eminent men, as he will there see, have turned their attention to this curious subject, amongst whom are Benedict Prevost, Venturi, and Caradori; and the results of their experi- ments will, I dare say, both interest and amuse your friend E. A. The paper alluded to is an abstract of M. B. Provost’s inquiries on the subject, by M. Biot, who considers that we may infer from them, as an established fact, that “ camphor is moved upon the surface of water by the effect of the emission of the particles which compose it; an emission that becomes per- ceptible to our senses by the smell which it produces, and by the repulsions which it exercises against small bodies floating upon the surface of water. As the effect resulting from these different impulses does not pass through the centre of gravity of the piece of camphor, this centre has a progressive motion, an the body revolves round it,” &c, E. A. conceives the rotatory 76 Scientific Notices—Miscellaneous. [JuLy, motion to be wholly produced by the centre of gravity of the piece of camphor, and of the fluid displaced by it not being in the same vertical line. If that were so, an irregular piece of any substance capable of floating on water should, under the same circumstances, exhibit the same phenomena as.a piece of camphor, which is not the case. Another, and .co- operating cause must, therefore, be looked for; and there seems no reason to doubt that it is correctly assigned in M. Biot’s abstract. Yours, F. B. 9. Improvement in Clocks. The public papers, sometime since, contained information of an improvement in timekeepers, invented by Mr. Dyer, of this city. We hope hereafter to furnish our readers with a more particular account of this invention than is contained in the following brief notice :— . The most important feature in this improvement. consists in the application of the spiral teeth to the wheel-work of clocks, and in this the pinion is reduced to a single tooth. By this happy idea, Mr. Dyer has greatly reduced the wheel-work necessary to a clock, and the friction is diminished in a still greater degree ; as all who are acquainted with the spiral gear- ing are aware that the point of contact, between two wheels with spiral-teeth, always coincides with the line of centres. Mr. Dyer has also contrived a very ingenious method of sus- pending the pendulum, in place of the spring, or knife-edge suspension. This method is to hang the mass constituting the pendulum to a plane, the under surface of which rolls at every oscillation upon a fixed convex body. He proposes to give such a curve to the convex surface, that the pendulum, in vibrating, shall be accelerated at every moment of its descent by a force proportional to the arch between it and the lowest point ; this condition being required to render the vibrations isochronal. Mr. Dyer has not yet demonstrated the curve necessary to obtain this result; but from the constant variation of the centre of oscillation, in a pendulum suspended in the above method, the cycloid is not the curve required. He is aware that his suspension cannot be executed with such accu- racy as to render the vibrations perfectly isochronal; but he may undoubtedly obtain a near approximation to a curve which would render them so.—( Boston Journ. of Philosophy and the Arts, May, 1824.) 10. Method of cleaning Gold Trinkets, and of preserving engraved Copper-plates. The method used by artists for cleaning gold trinkets is the application of a mixture of neutral salt, intended to disengage nitric acid, with the assistance of heat. Dr. Mac Culloch re- commends instead to boil the trinkets in water of ammonia, 1824.} New Scientific Books. 97 which dissolves the metallic copper of the alloy to a certain depth on the surface, so that after the operation the metal is in fact gilded, nothing but pure gold being visible. In this pro- cess the waste of gold, which is dissolved by the acid, in the process usually employed, is avoided. Dr. Mac Culloch observes, “ that it is an unaccountable omission of chemists not to have observed that metallic copper is soluble in ammonia. The solution takes place rapidly in the heat at which the water of ammonia boils.” Copper-plates are apt to be injured by laying by; a thin coat of oxide forms on the surface, which is rubbed off by the hand of the workman in the first inking, when the plate is again called into use ; and by repetition of the formation of oxide, and its removal, the fine lies on the plate are soon injured, and ultimately obliterated. Dr. Mac Culloch recommends the ap- plication of common spirit varnish to the surface when the plate is laid by ; itis easily applied, and can be removed when requi- site by spirit of wine.—(Edinburgh Journal of Science.) ARTICLE XV. NEW SCIENTIFIC BOOKS. PREPARING FOR PUBLICATION, The Fourth Volume of the New Series of the Memoirs of the Man- chester Literary and Philosophical Society. A Compendium of Medical Theory and Practice, founded on Dr. Cuilen’s Nosology, which will be given as a Text Book. By D, Uwins, MD. in a duodecimo volume. Muscologia Britannica: containing the Mosses of Great Britain and Ireland. By W. J. Hooker, FRS. ASL. &c. and T. Taylor, MD. MRIA. FLS. &c. 8vo. With Plates. Mr. Swainson will speedily publish in an octavo volume, with six Plates of the most beautiful humming Birds of Mexico, the “Zoology of Mexico,” illustrated by general Remarks and scientific. Descrip- tions of the Animals collected by Mr. Bullock; to whose ‘fravels the work is intended as an Appendix. JUST PUBLISHED. Wade’s Observations on Fever. 8vo. 4s. Woodford’s Catalogue of Phenogamic Plants in Edinburgh. [2mo. 3s. 6d. _ Harrison’s Surgical Anatomy of the Arteries. Vol. I. 12mo,. 5s. Sandwith’s Introduction to Anatomy and Physiotogy. 12mo, 9s. The Butterfly-Collector’s Vade-Mecum. 12mo. 5s. Stevenson’s Historical Sketch of the Progress of Discovery, Navi- gation, and Commerce, from the earliest Records to the beginning of the 19th Century. 8vo. 14s. 78 New Patents. — [JuLy, Otter’s Life and Remains of the Rev. E.D. Clarke. 4to. 3/. 3s. The Encyclopedia Metropolitana, Part XII. containing, among other subjects, the completion of the article on Magnetism, Electro- magnetism, and Electricity; and from Car to Cur in the Miscella- neous Division. ArTIcLeE XVI, NEW PATENTS. J. Crosby, Cottage-lane, City-road, for his improvement in the con- struction of lamps or lanterns, for the better protection of the light against the effects of wind or motion.—May 5. ut Viney, Shanklin, Isle of Wight, for improvements in water-closets. —May 6. W. Cleland, Leadenhall-street, for his improvement in the process of manufacturing sugar from cane juice, and in refining of sugar and other substances.—May 6. J.T. Paul, Charing Cross, mechanist, for improvements in the me- thods of generating steam, and in the application of it to various use- ful purposes.—May 13. J. Potter, Smedley, Lancashire, spinner and manufacturer, for cer- tain improvements in looms.—May 13, J. Perkins, Fleet-street, engineer, for his improved method of throw- ing shells and other projectiles.—May 15. W. Church, Birmingham, for improvements in the apparatus used in casting iron and other metals.—May 15. J. H. Ibbetson, Smith-street, Chelsea, for improvements in the ma- nufacture of gas.—May 15. L. W. Wright, Wellclose-square, engineer, for improvements in machinery for making pins.—May 15. J. Luckcock, Round Cottage, Edgebaston, near Birmingham, for his improvement in the process of manufacturing iron.—May 15. W.H. James, Cobourg-Place, Winson-green, near Birmingham, engineer, for his improved method of constructing steam-carriages.— May 1b: T. Parkin, Bache’s-row, City-road, merchant, for improvements in machinery for printing. —May 15. J. Dickinson, Nash Mill, Hertford, for his method of cutting cards by machinery, and also a process for applying paste or other adhesive matter to paper by means of machinery.—May 20. J. Cook, Birmingham, gun-maker, for improvements in the method of making and constructing locks for guns, pistols, and other fire- arms.—May 20. T. Marsh, Charlotte-street, Portland-place, saddler and harness- maker, for an improvement in the making of saddles——May 20. J. Viney, Shanklin, Isle of Wight, for his method of supplying water or fluids for domestic or other purposes in a manner more extensively and economically than has hitherto been usually practised —May 22. B, Black, South Molton-street, Hanover-square, lamp manufacturer, for his improvement on carriage-lamps.—May 25. 1824.) .. | Mr. Howard’s Meteorological Journal. 79 ArtTicLe XVII. METEOROLOGICAL TABLE, ee BAROMETER, THERMOMETER, | 1824, Wind. Max. Min. Max. | Min. | Evap. | Rain. 5th Mon | May 1S W){ 30°05 30°00 66 51 as 11 2) N 30°00 29°71 61 Al — 24 3N Wi 29°77 29-69 47 40 _— 28 AIN WI] 29°98 29°77 52 39 = — 5iS W! 30°01 20:98 62 oS ees 08 6s Wj 3001 | 2999 | 66 | 42 | — 05 71 ON 30°27 30°01 68 43 — si N 30°40 30°27 68 48 5 9S E 30°40 30°13 62 39 | — 10N E| 3013 30°09 69 42 84 | 1 |B 30°09 30:03 54 44.) — — LOIN .n. Bly £3003 29°99 53 40 | — 17 13IN- E! 29°99 29:70 50 42 —_ 48 14IN- E} 29°70 29:67 48 43 — 59 15IN- E| 29°91 | 29°65 46 42, — 1°67 16| N 30°05 29°91 56 37 jo=— = 17IN W)\ 30°06 $0°05 | 55 44 — 18IN W| 30:06 29:93 | 55 37 —_ _ 19N W| 29°93 29°87 56 40 — 20.N WI 30:00 29°87 57 29 a 21) E 30°07 30-00 61 32 — | 22\IN E| 30°07 50°03 56 32 —_- i —_ 23IN W! 30°03 30°02 | 61 | 42 —|— 24, N 30°26 30°02 58 | S4 04 11 25IN E| 30°49 30:26 62) “|, 948 —_ 26| N 30°64 30°49 72 | 46 — QIN Wi 30°64 30°61 70 40 — 285 W) 30°61 30°40 | 76 41 —_ 29IN EE! 30°40 29°98 69 ; 51 — 30} E 29°99 29:98 68 48 — 01 3118S W{ 30°23 29-99 70 48 | <2 30°64 29°65 76 | 29 | a60! 379 The observations in each line of the table apply to a period of twenty-four hours, beginning at 9 A. M. on the day indicated in the first column. A dash denotes that the result is included in the next following observation. 80 Mr. Howard’s Meteorological Journal. (Ju1yx, 1824. REMARKS. Fifth Month.—1. Fine. © 2, 3. Rainy. 4, 5, Showery.. 6—8. Fine. 9. Fine: a solar halo, coloured, a little before sunset. 10, Fine: a lunar halo of the largest diameter. 11. Overcast: cold wind: a lunar halo at night, with a bright spot on each side, at the same height as the moon. 12. Showers. 13. Rainy. — 14, Rainy. 15, Rain, without ceasing, all day. 16. Cloudy. In consequence of the heavy rains of the last four days, amounting on the whole to 2°91 inches, a flood was naturally ex- pected this morning ; and towards evening the waters rose suddenly in the sea, and passing over all the banks of the level, soon filled the marshes, and in the course of the night rose to an unprecedented height, being 25 inches higher than in the flood of 1809. The houses in the marshes south of the road were filled nearly to the chamber floors, and some of the inmates removed with great difficulty: the flood remained stationary for nearly 24 hours. On the 17th in the afternoon, it began very gradually to subside, and on the 18th, in the morning, was much abated ; the marshes still presenting the appear- ance of a bed, the tops of the trees appearing in places only, 17—19. Cloudy and fine. 20—23. Fine. 24. Morning showery. 25—29. Fine, 30. Fine: a slight shower in the morning. 31, Cloudy and fine. RESULTS. Winds: N, 6; NE, 8; E,3; SE,1; SW, 5; NW,8. Barometer: Mean height For the month. ....-..sseseceeceseeserecccsceees 30-070 inches. For the lunar period, ending the 20th. ..........--+++ 29°916 For 14 days, ending the 8th (moon north). .......... 29°972 For 14 days, ending the 22d (moon south), ........«- 29°978 Thermometer: Mean height For ‘the month. . 0355/00 ase sfsaie side oc ge aphid uae’ ge cidivee Dl OREO For the lunar period. ......00.0-scocesseessecsesess Ol'O00 For 31 days, the sun in Taurus........ deaees aces 51-693 EXVRWRWALION, o.0\c0 cane ein aaieisige amuayine 5» siaeiencanstel sieisaia was'sisisisees 2:00) alts Rain 2 os), hac ce ebee ita tase mtceideld caus ord Cicacoseitee waleicalceiee seememontet Laboratory, Stratford, Sixth Month, 24, 1824. R. HOWARD. ANNALS 3 OF PHILOSOPHY. AUGUST, 1824. ArTICLE I. Remarks on Solar Light and Heat. By Baden Powell, MA. of Oriel College, Oxford, and FRS. (Continued from vol. vii. p. 406.) (27.) In the conclusion of a former paper I alluded to some further experiments which were to follow, relative to the ques- tion of the proportion obtaining between the heating and illumi- nating effects of the solar rays. The method of experimenting alluded to is one which I have not been able to apply to any extensive series of different intensities. It consists in compar- ing the effect produced on a blackened thermometer by the focal light of different lenses, with the relative calculated inten- sities of the rays in those foci. Thus we may ascertain whether at these high intensities the same proportion is maintained. Without proof we cannot assume that it is; and a very few comparisons may be sufficient to show, whether the proportion is nearly preserved, or whether there be any considerable devia- tion from it. (28.) When thermometers are exposed to the action of radiant matter there are several considerations to be attended to in comparing their observed risings ; and it will be convenient in the first instance to bring these considerations into one point of view, A thermometer exposed to radiant matter absorbs heat only on one-half of its surface, while the other half is radiating again its acquired heat, and the observed effect depends upon the equilibrium which obtains between them. In particular cases only part of one surface may be exposed to heat: the difference between such part and the whole surface, together with the absorbing and radiating powers of the surface, must, therefore, be taken into consideration, as also the rate of communication of heat dependent on the mass. New Series, vow. Viit. G 82 Mr. Powell on Solar Light and Heat. [Aue. Let the portion of the surface of the bulb exposed to radiant matter ....... re ee PR ree Diameter of the bulb. ...... slat wala no ss Dis BUPfAce.. ss 6.0 wien Miele fee Pel WQUM ed ow SEER The observed rise in a 2 given SNE ohe'na dha wheteia ty ieemtal The power of the coating for absorbing heat (of what- ever kind)...... a a a eee eam coy’ vaiati NT Abit FAG Seis tits Udicsc'ors Se Miele eee The intensity of heating power ........0eceeeee 22% Qs Pp k h The general formula easily deduced on the above considera- tions will be, fe . @.p.d* RS h Gaye 2 a.p d(s—a)k he = ba nd the! B 4 When the whole bulb is eaten And. Lard. Comparing two different cases, hpk, _ t.d,a,(s — a) hypyk oe T,. dy. a (8; — a) ; k If h = h, we thus obtain the value ot Sar 1 + a, (s — a) .a(s — 4) And if the coating be the same, it = - and ifh = h, it = 1. DG vai ee If the bulbs are equal, this = pais et See When the whole bulb is exposed, we have hpky _ red hp,k r+ dy eorrereerereree ee eer e see eee (C) Tf in this last case the thermometers be exposed to simple radiant heat, assuming the universality of the law, that the absorptive is proportional to the radiating power of a surface, we shall have = k,and p, = k, And if h = h, then ** = 1, or = 2h Or hence we might derive a neat and simple method of veri- fying that law. The relative values of p and k as compared with a surface of glass in particular cases, may be obtained by coating only half 1824.)] Mr. Powell on Solar Light and Heat. 83 the surface of the bulb, and exposing either the plain or coated side to the same intensity of heat. The ratio= may be obtained by heating two bulbs completely coated to the same point, and observing their rates of cooling. The case (C) is the same as that investigated in the Phil. Trans. 1800, No. 19, note, p. 447. (29.) Comparison of the Focal Effect of Two Lenses on a Ther- mometer coated with Indian Ink. Focus, Min. Lets 1. t Lens 2. ars ia 4, eed iehet Diff. 0 18 —_ 18 oom: 1 50 320 27 11-0 nowg 15 dactiotto 1p 16 bein allt yon 1 45 30°0 26 10:0 Sy a, 19 ar Fin i she cant din aes 1 5] 32°0 26 10:0 ee Mea ee te In order to proceed to this comparison, we must first observe, that when in the formula we take a. d*, it is on the supposition that parallel rays impinge on a spherical surface. With the focus this is not the case, and from the convergence of the rays, as well as from their greater intensity at the outer edge, we may in this case assume, without fear of error, that a = the area of the section of the rays impinging, and thus apply the formula. Thus we have the following data : From the above experiments, 7, = 10, 7 = 31: it is also evident, thatp = p,andk = k,. By measurement, the diame- ters of the focal disks were : Lens 1. Lens 2. 0°25 inch 0:16 inch .”. the areas 0°049 == a 0:021 = a, d = 0°45 «.s = °636. Hence s — a, = °615 8s — a = ‘587, and we have to apply the case of the formula (B) bP iee My LE RAs ork ati SOA 1 6s > SOL) Pee ee (30.) In order to calculate the respective intensities of light, or number of rays collected in the focus of each lens, we may easily proceed by the well-known theorem, G2 84 Mr. Powell on Solar Light and Heat. [Avc. Let d = diameter of aperture, JS = focal length of lens, No.1. And d’, f’, those of lens, No. 2. I, and I’, = the respective intensities of the rays collected in the sun’s image, or focal luminous disk. Then we have Ia. f? P< ge P By measurement I found In Lens, No.1, d = 3:25 in. .. d? In Lens, No. 2, d’'= 1-75 ins ocd” | f’ oe | coo } ~“ Hence Z. = 2086 x 9 _ 95:04 ence 7 = 3-06 x 5625 17212 ~ Tel If we admit the validity of certain experiments which seem to prove the existence of an exterior heat surrounding the luminous cone of rays, this would affect the bulb in each case by a small quantity in addition to the direct effect of the light. But since the total effect has been shown to be very closely in proportion to the intensity of focal light, it would follow that this exterior heat must be in extent, or in energy, exactly in the same pro- portion, supposing its absolute value sufficiently great to produce a perceptible effect. These experiments prove for the two particular intensities under examination, that the proportion of heating to illuminating intensity is closely maintained. It might be satisfactory to extend the comparison with lenses of other powers, qualities, &e. but as the above result is not of a nature which requires the admission of any new principles, and agrees with what we should be prepared to expect, I conceive it unnecessary at present to carry the examination any further. (31.) With a similar object in view in some subsequent expe- riments, I employed such a difference of intensity as is afforded by two sections of the luminous cone formed by a lens, one being made near the lens, and the other near the focus. In two such positions, one, at } inch from the lens, the other near the focal point, or at about seven inches distance, the thermometer, blackened as before, was placed successively. The rise in 30 seconds was (mean of three trials), At. inch fromplens.aeiiiea dite. PQS or Near focus. eceeeeresew esr eeeees 40 — To obtain the proportions of light in the two cases, I measured the diameter of the luminous circle formed by the larger section when the rays were intercepted by a plane at the distaace of one-quarter of an inch below the lens. The diameter was very nearly 2°8 inches = d, whose square = 7:84; the diameter of nearly. 1824.] Mr. Powell on Solar Light and Heat. 85 the bulb (as before) = 0°45 inch; the diameter of the section near the focus = d, = 0°3 inch; its square ‘09. In order to obtain the true ratio of the heating effects, we have to apply the case of the formula (B). By experiment, we have — = Le by measurement a, = 0706. And s = 6361 «.s — a, = *5655. Here also the case of the formula (C) applies, and we have SE = 2; thus on the whole since p = p,,and k= k, h 2 x ‘0706 Rs 1 iz, = ( “5655 =) =m Hence also we have for the intensities of light in the two cases, Dheh At, ts 0, td i” @” 784” 8 In obtaining this ratio, however, there are evidently several sources of error; the loss of many rays before they arrive at the focus; the less intensity towards the central part of the cone (where the thermometer was placed), on these, and, perhaps, other grounds, it would be necessary to reduce the ratio obtained. The former ratio (as also in other instances) is subject to some uncertainty, owing to the difficulty of observing accurately the rise of the thermometer under the strong impression of focal light ; but upon the whole it is evident that here also an equality of ratio may be inferred as nearly as the nature of the operations will allow. If there be an exterior heat about the focus, this should affect the above ratio; but since the proportion obtaining is very close, we may infer that the ratio of the intensities of light is really greater than that of the heating effects, but that the pro- portion is preserved by the sum of the heating effect of the focal light, together with the exterior heat. The above experiment cannot be considered sufficient to enable us to determine such a point, but I hope shortly to be able to give it a more complete examination. (32.) In like manner we might proceed to compare the effects of the rays in their natural diffuse state, and when brought to a focus, if we had any tolerably accurate method of allowing for the quantity of light lost in passing through the lens, and in not converging accurately to the focus. The former datum might, perhaps, be supplied from Sir W. Herschel’s determination (Phil. Trans. 1800), and the latter we might probably estimate by successively diminishing the aperture till the focal effect on the thermometer becomes S sminishied. The least aperture with which it continues undiminished, compared with the whole, would give nearly the proportion of rays brought to the focus. (33.) In the preceding instances we have compared the pro- 86 Mr. Powell on Solar Light and Heat. [Auc. portion of heating to illuminating effect in respect to light of different intensities. Another point of inquiry which appeared to me not uninteresting in relation to the same subject, is the similar question with respect to the proportions of heating effect developed by differences of light in respect of the light or dark colour of surfaces: and whether the same proportion which is observed in the heat produced on a black and on a white sur- face at ordinary intensities is preserved or not at higher degrees of concentration in the rays. The heating effect of light is commonly said to be produced by the absorption of the rays, and is supposed to be proportional to the degree of that absorption. In order to advance towards a clear and systematic knowledge of the subject, it would be necessary that this should be proved, especially as we may thus become better acquainted with the nature of the heating effect developed or excited when light impinges on surfaces of different colour. We have not, perhaps, any very precise idea as to the mode by which light exerts its heating power; nor can it be assumed that any exact proportion is followed by the absorbing power of surfaces, with the degree of heat produced. It is obvious that a variety of laws may be supposed to obtain. The heating effect may not be in proportion to the quantity of light absorbed, or the quantity absorbed may not be in the pro- portion ofthat impinging, or both may take place jointly. It, therefore, becomes necessary to inquire, first, whether on the black and the white surface the heating effects are in the same ratio as that of the intensities of light acting upon them; secondly, whether, in the case of the diffuse and of the concen- trated rays, the black and white surfaces receive heating effects in the same ratio as that of the light which acts upon them in respect to their colour. : (34.) In order to follow up these inquiries, the following expe- _ riments were tried. I employed two thermometers, one having its bulb coated with Indian ink, and the other with a thin paste of chalk and water. They were both fixed on one mounting, so that it might be safely assumed, that they were both equally exposed to the heating power to which they were subjected ; and the bulbs were completely free from any contact with the mounting, more than one-eighth of an inch intervening on all sides. By measurement, the following data were obtained : Diameters of the bulbs....... d=°55in. d,="45 Whence the surfaces ........ 8=°950 5, = "630 Diameter of the focal disk = -25, whence its areaa = °049.., —+049 —+049 ‘001las—a 587 a5, a Anda = «a,~° 1824.] Mr. Powell on Solar Light and Heat. 87 Substituting these values in the formula (A), we have, with the focus, the correction P s—a 55 901 1000 18T Pi) seep eae 4 587 Sel baie With the diffuse rays, : DECOIRES pends css ccgese OD 1000 192 z = pis ° Oo j00° (35.) To compare the heating effects, the following sets of experiments were made : Focus. Rise in 30 seconds. paow rays. Rise in 2 minutes. Th. A. White.| Th. B. Black. ‘Th. A. White.|Th. B. Black, eae eae | pi psicalan-tahcasninstbd 4 12 47 25 6°5 11 44 2 5°5 11 42 1 25 11 45 2:75 7 12 48 1:25 3 10°5 40 3 7 12 47 12 47 The ratios of these respective quantities in each case agree very nearly among themselves. We may obtain the mean ratio in each case by takin Mean 11-4} 45 pee. 5'6 , 1 r 1 ; Hence 5g 7 26 Hence, since in each case, h = h, we obtain in the ont chee, Se See SS ok ~~ 3°9.°* 582 72:07? ‘ pk, 1 1000 1 And in the oth =— x — ===. shi eek k 2°6 x 318 2-12 (36.) Another set of experiments in which the coatings were mutually changed, were as follows: EE a ee a ce Focus. Rise in 30 seconds. {Diffuse rays. Rise in 2 minutes. Th.A. Black,|Th, B. White.|Th. A. Black. vanied bined B. White. ——_——_ a 25 18 5°25 2 28 16 4°25 2 27 16 7:6 3 28 17 5 1°75 28 17 6 2:75 26°5 17 7°75 o5 Mean 6 ex. 27 16°8 595 25 ee 1 r 1 r, 16 ae phy i 100 1 pk, 1 100 1 pik 6 * 187 ~ 29 pk 23 ™ Te = 96 88 Mr. Powell on Solar Light and Heat. [Auc. The former set of experiments gives the ratio in the focus somewhat less than in the diffuse rays, the latter somewhat greater. We may, therefore, fairly infer, that the ratios are very 5 1 ] nearly equal in the two cases. The means are 57; and =: The small difference between these two sets of experiments must be attributed to the impossibility of laying on the coatings in the second instance so as to be sure that they are of precisely the same thickness, roughness, &c. as in the first; but the dis- agreement is so small as to show that such an equality was as nearly attained as perhaps was possible. (37.) Being in possession of these two sets of experiments, we might have deduced the result without any reference to the formula. Proceeding by this method, therefore, we may ascer- tain the accuracy of the data, and thus also tend to show how far the other investigations here made are to be relied on. It will be evident that we have in these two sets, with the foci, pk, 1 m Pa anaes tua Ist set. And 2" = x " 2d set py k 16 m : (pki)? _ 1 1 Whence @.bi 39x 16 * GRP pa? ky ps yh ej And. rae o nearly. In the same way with the diffuse rays, k 1 ' atery x — Ist set. I k 1 G And 2 = — x — 2d set. py k 23 m (p ky ! Hence, as before, a wie S ey : And. een nearly, results which agree very closely with those otherwise obtained. (38.) In order to separate from this result the value of = I I ascertained 7 by independent experiment: heating the two thermometers to the same point, and then observing their-rates of cooling, as follows : 1824:] Mr. Powell on Solar Light and Heat. 89 Th. A. White. Th. B.. Black. Diff. Dit Heated toh fo 284.5. 23 93 Cooled in 2 minutes to | 21°25 1°75 21 | 2 98 pdeechesih dicho 25 3 DA: 75 ues:25 24 5 1 a ct iD Pats DAIS 2°5 93 93 20 es 19°75 320 Mean Defy 2°75 Tr I Hence ag are Hence on the same principles as before (r and 7, being now the respective rates of cooling), we have k rd : . Saag 0 Ae and since by experiment Teg. tt d _ 1000 Sas ae ae" Pk 2 HOO We obtain = = : p ky 1 Whence taking ce ae get y ian as Here again if when the focus was thrown on the bulb, it was encompassed by a sort of penumbra of a heating effect, this being of the same nature as simple heat, acted on the black and white surfaces in the inverse ratio of the diameters, and, there- fore, tended by the addition of very small quantities in that ratio to each of the terms of the ratio, to increase it, though probably the effect was altogether too small to be perceptible. (39.) We now proceed to compare these heating effects with the intensities of light absorbed by the black and white surfaces. In the first instance, I attempted roughly to estimate the pro- per aor of light reflected, and thence reciprocally absorbed by lack and white surfaces in the following manner: On a red round were fixed a black and a white small circular disk ; also two similar disks on a blue ground. Remaining ata fixed dist- ance from them, having first darkened the room completely, L increased by degrees the aperture of a sliding shutter, till first the white disk, and then the black, became visible. This was repeated several times, and the mean ratio of the size of the 90 Mr. Powell on Solar Light and Heat.. fAue. aperture necessary for the two effects would give the proportion of light reflected by the disks. In the same way also I tried the distances from the eye at which the disks became invisible in a room partially darkened. Such trials, however, can never be susceptible of any accuracy from the difficulty of saying precisely when the object is visible or not. I, therefore, conceive it unnecessary to detail them further than to mention, that the results uniformly gave a ratio not very different from that above given, as the ratio of the heating effects produced respectively by’ the proportions of light which we suppose absorbed by the surfaces. It became necessary to seek for some other method of ascer- taining this point ; and in this I succeeded as follows : (40.) Assuming that within ordinary limits, the heating effect is precisely as the number of rays impinging, we may proceed to a simple and, perhaps, sufficiently accurate method of esti- mating the relative proportions of light absorbed by the black and white surfaces employed on the thermometers from observ- ing the quantities reflected. These data I obtained by placing the photometer in the sun’s light having the bulb protected by a small screen from the direct rays, and, therefore, affected only by the light reflected from a surface of paper, painted in one instance with Indian ink, and in another with chalk; and fixed in contact with the outside of the glass case of the instrument, on the side opposite the sun, and extending round two-thirds the circumference of the cylinder. The following are the results of a set of experiments conducted in this way : Rise in 1 minute by light reflected from Exp. = eel ae Be hee Ce Black surface, White surface. 1 6 14 2 6 12 3 6 3 4 7 14 5 6 14 To obtain the mean ratio : 6:2 : 13°4 i Or 1 2°1 nearly Hence we may take the proportions of light absorbed by the two surfaces in the inverse of this ratio. This ratio may, however, possibly be rather too small, from the circumstance that a small portion of light would be reflected upon the bulb from the inner surface of the glass, which would be the same in both cases. If on this consideration we take it = this ratio, it will 1 Bae eee ee ee eee 1824.] Mr. Powell on Solar Light and Heat. 91 be evident, agrees as nearly as we can expect with that before obtained for the heating effects developed upon or by the black and white surfaces under examination; and which was shown to be nearly the same, whether the light was in its ordinary inten- sity, or at a high degree of concentration. (41.) We have thus established that with considerable differ- ences in the intensity of light acting, the heating effects on a black and a white surface maintain the same ratio very closely. It has also been shown that on the same surface, with different intensities of light, the heating effect is proportional to the intensity of light. At one intensity it is shown that the heating effects on the black and white surfaces are proportional to the quantities of light respectively absorbed by them. Hence the heating effect is proportional to the light absorbed by the surface in respect to its colour, at all éntensilzes. Hence also the light absorbed at different intensities 1s propor- tional to that impinging on the same surface. These conclusions contain, perhaps, no information absolutely new ; but in establishing experimentally what seems hitherto to ‘have been only taken for granted on loose grounds, I conceive we may best prepare the way for investigating the nature of the heating power of light, and for examining whether it be analo- gous to any other phenomena. One step appears to me to be gained in having, as f think, clearly shown the exact proportion- ality in the heating effect to the quantity of light acting, and shown to be actually absorbed by the surfaces. These experi- ments also confirm (if further proof be wanting) the conclusion that the sun’s heating effect is of a simple nature. (42.) It may not be altogether superfluous here to remark, the dependance of the results in the former portions of these inqui- ries (see (18) of the paper inthe Annals for June), upon the con siderations laid down in the present paper (28). It will be thence evident that without knowing any thing of the relative powers of the surfaces for absorbing simple heat or radiating it again, if any such heat were intercepted by the glass, the effect on removing it would have been a diminution of ratio by the addition of equal quantities to its terms ; supposing that the heat were instantaneously communicated from the front to the back of the bulb. If this were not the case, but a certain time were required for the effect to be produced, it would at the first moment be an addition of quantities in the ratio of the absorptive powers of the surfaces for simple heat ; this, in the present case, would be a ratio of “ greater inequality,” and as appears from (38) nearly = a é Again, with respect to the subsequent experiment (Annals, 92 Mr. Powell on Solar Lighi and Heat. [Aue, June, (19), (20), it is equally obvious that the same distinction must be attended to ; but if the lower bulb were only coated on the half of its surface exposed to the sun, the effect (if any were produced) would be greater, since here the ratio of “ greater inequality ” must operate. In this way I have repeated the experiment with a half coating of chalk, but with results so pre- cisely the same as before, that no diminution was perceptible. In order to try the effect with a coating of still greater absorp- tive power, I repeated the experiment with a bulb half coated with white silk pasted on; the other being entirely painted with Indian ink. No diminution took place, as will be evident from the following results. The instrument was of a larger construc- tion, and not graduated by Prof. Leslie’s scale. Large differential thermometer. Bulbs, Indian ink; and white silk on half. Graduation from white. Glass over white bulb, 3 inches. Both exposed. 14° eeoeeeeeee eee eae ] 4° 15° esvpeeoeeveeeeeeee 1 iB, fn Acai ct et Seah: Seine | leans ee es ga Spey hap peel page i 16° a 4 ects ale ieeiel . (43.) The question above alluded to (31, &c.) as to the exist- ence and magnitude of a heating effect exterior to the cone of light formed by alens, is one of the greatest curiosity and inte- rest, especially as connected with what appears to be the analo- gous effect in the case of the prismatic spectrum. In a supple- ment to a paper on the latter subject, communicated some months since, and now before the Royal Society, I recorded a few imperfect experiments, in which it appeared to me that this phenomenon was clearly perceptible with a lens of about three inches aperture, and 7°5 focal length, by means of the differen- tial thermometer; and I have since repeatedly observed the same thing, though from the smallness of the effects observed J am inclined to suppose that they could hardly have interfered in any sensible degree with the experiments described in the present paper. From the very small intensity of the effect in question, { have experienced great difficulty in applying both the test of its transmissibility through glass, and that of its relation to sur- faces, so as to come to any decisive conclusion. I hope shortly to be able to bring forward some investigation of these points. Meanwhile, as connected with the subject of the present paper, I may be permitted to give the results of a few experiments, which clearly establish the existence, and convey an idea of the quantity of this effect ; and which were made with a different instrument, and under different circumstances, from the few just alluded te. 1824.) Mr. Powell on Solar Light and Heat. 93 (44.) Observations of the heat exterior to the cone of light formed by a lens. Aperture, 3°25 inches ; focal length, 7-5. Bulb of photometer coated with Indian ink, in glass case. r Indication of photometer. Distance without the) Distance from lens. Exper. 1. Exper. 2. 7°5 inch (at focus) 17° 16° 6 12° 129" $19 4 12° 10° g° go 7° go go Close under lens. g§° 7° Te % inch, 75 inch (lens covered) Bors 1-25 inch (under the furthest part of the 7:5 (lens open) 4° shadow). The two last observations show how much of the effect is to be attributed to reflected light. (45.) The experiment of Sir W. Herschel, from which a maxi- mum heating effect further from the lens than the focus of greatest light is inferred, will be found in the Phil. Trans. 1806,. No. 15, Ex.23. It there appears that sealing-wax was scorched in the same time in the focus, and at half an inch further from the lens ; whilst at half an inch nearer, no effect was produced in double the time. It can, perhaps, scarcely be inferred, that this effect is due to the same cause as that which operates outside of the luminous cone; since it is obvious, that beyond the focus the light again diverges, and we cannot with certainty distinguish the effects due to light under the peculiar modifications to which it may there be subjected, from those which may arise from some peculiar development of heat in the same position. The mere inspection of the adjoining diagram will illustrate the di- rections which the differently coloured rays, separated by the dispersive power of the lens, are made to assume ; and with their different combinations it is highly probable that very different heating effects are produced. This is a topic of great interest, and one which, if more thoroughly examined, seems likely to lead to a more complete acquaintance than we at present possess with the nature of the heating effects developed both by the rays of light themselves, and at short distances from them. 94 . Sir H, Davy on the Corrosion of ‘[Aue. Artic.e II. On the Corrosion of Copper Sheeting by Sea Water, and on Methods of preventing this Effect ; and on their Application to Ships of War and other Ships. By Sir Humphry Davy, Bart. ou TES,, Ba Se 1. Tux rapid decay of the copper sheeting of his Majesty’s ships of war, and the uncertainty of the time of its duration, have long attracted the attention of those persons most con- cerned in the naval interests of the country.. Having had my inquiries directed to this important object by the Commissioners of the Navy Board, and a Committee of the Royal Society hav- ing been appointed to consider of it, I entered into an experi- mental investigation of the causes of the action of sea water upon copper. In pursuing this investigation, I have ascertained many facts which J think not unworthy of the notice of the Royal Society, as they promise to illustrate some obscure parts of electro-chemical science; and likewise seem to offer important practical applications. 2. It has been generally supposed that sea water had little or no action on pure copper, and that the rapid decay of the cop- per on certain ships was owing to its impurity. On trying, however, the action of sea water upon two specimens of copper, sent by John Vivian, Esq. to Mr. Faraday for analysis, I found the specimen which appeared absolutely pure, was acted upon even more rapidly than the specimen which contained alloy : and, on pursuing the inquiry with specimens of various kinds of copper which had been collected by the Navy Board, and sent to the Royal Society, and some of which had been considered as remarkable for their durability, and others for their rapid decay, I found that they offered very inconsiderable differences only in their action upon sea water; and, consequently, that the changes they had undergone must have depended upon other causes than the absolute quality of the metal. / 3. To enable persons to understand fully the train of these researches, it will be necessary for me to describe the nature of the chemical changes taking place in the constituents of sea water by the agency of copper. When a piece of polished copper is suffered to remain in sea water, the first effects observed are, a yellow tarnish upon the copper, and a cloudiness in the water, which take place in two or three hours: the hue of the cloudiness is at first white ; it gradually becomes green. In less than a day a bluish-green precipitate appears in the bottom ofthe vessel, which constantly * From the Philosophical Transactions for 1824, Part I. 1824.) Copper Sheeting by Sea Water, &c. 95 accumulates ; at the same time that the surface of the copper corrodes, appearing red in the water, and grass-green where it is in contact with air. Gradually carbonate of soda forms upon this grass-green matter; and these changes continue till the water becomes much less saline. The green precipitate, when examined by the action of solu- tion of ammonia and other tests, appears principally to consist of an insoluble compound of copper, (which may be considered as a hydrated sub-muriate) and hydrate of magnesia. According to the views which I developed fourteen years ago, of the nature of the compounds of chlorine, and which are now generally adopted, it is evident that soda and magnesia cannot appear in sea water by the action of a metal, unless in conse- quence of an absorption or transfer of oxygene. It was therefore necessary for these changes, either that water should be decom- posed, or oxygene absorbed from the atmosphere. I found that no hydrogen was disengaged, and consequently no water decom- posed : necessarily, the oxygene of the air must have been the agent concerned, which was made evident by many experi- ments. Copper in sea water deprived of air by boiling or exhaustion, and exposed in an exhausted receiver or an atmosphere of hydro- gene gas, underwent no change; and an absorption in atmosphe- rical air was shown when copper and sea water were exposed to its agency in close vessels. 4, In the Bakerian Lecture for 1806, I have advanced the hypothesis, that chemical and electrical changes may be identi- cal, or dependent upon the same property of matter: and I have farther explained and illustrated this hypothesis in an elementary work on chemistry, published in 1812. Upon this view, which has been adopted by M. Berzelius and some other philosophers, I have shown that chemical attractions may be exalted, modi- fied, or destroyed, by changes in the electrical states of bodies; that substances will only combine when they are in different electrical states ; and that, by bringing a body naturally positive artificially into a negative state, its usual powers of combination are altogether destroyed; and it was by an application of this principle that, in 1807, I separated the bases of the alkalies from the oxygene with which they are combined, and preserved them for examination ; and decomposed other bodies formerly supposed to be simple. tag? ge t was in reasoning upon this general hypothesis likewise, that I was led to the discovery which is the subject of this paper. Copper is a metal only weakly positive in the electro-chemical scale; and, according to my ideas, it could only act upon sea water when in a positive state; and, consequently, if it could be rendered slightly negative, the corroding action of sea water 96 Sir H, Davy on the Corrosion of [Auc. upon it would be null; and whatever might be the differences of the kinds of copper sheeting and their electrical action upon each other, still every effect of chemical action must be prevented, if the whole surface were rendered negative. But how was this to be effected? [ at first thought of using a Voltaic battery ; but this could be hardly applicable in practice. I next thought of the contact of zinc, tin, or iron: but I was for some time pre- vented from trying this, by the recollection that the copper in the Voltaic battery, as well as the zinc, is dissolved by the action of diluted nitric acid ; and by the fear that too large a mass of oxidable metal would be required to produce decisive results. After reflecting, however, for some time on the slow and weak action of sea water on copper, and the small difference which must exist between their electrical powers ; and knowing that a very feeble chemical action would be destroyed by a very feeble electrical force, I resolved to try some experiments on the sub- ject. I began with an extreme case. 1 rendered sea water slightly acidulous by sulphuric acid, and plunged into it a polished piece of copper, to which a piece of tin was soldered equal to about 1-20th of the surface of the copper. Examined after three days, the copper remained perfectly clean, while the tin was rapidly corroded: no blueness appeared in this liquor; though, in a comparative experiment, when copper alone and the same fluid mixture was used, there was a considerable corrosion of the copper, and a distinct blue tint in the liquid. If 1-20th part of the surface of tin prevented the action of sea water rendered slightly acidulous by sulphuric acid, I had no doubt that a much smaller quantity would render the action of sea water, which depended only upon the loosely attached oxy- gene of common air, perfectly null; and on trying 1-200th part of tin, I found the effect of its preventing the corrosion of the copper perfectly decisive. 5. This general result being obtained, I immediately instituted a number of experiments, in most of which I was assisted by Mr. Faraday, to ascertain all the circumstances connected with the preservation of copper by a more oxidable metal. I found, that whether the tin was placed either in the middle, or at the top, or at the bottom of the sheet of copper, its effects were the same; but, after a week or ten days, it was found that the defensive action of the tin was injured, a coating of sub-muriate ee formed, which preserved the tin from the action of the iguid. With zinc or iron, whether malleable or cast, no such diminu- tion of effect was produced. ‘he zinc occasioned only a white cloud in the sea water, which speedily sunk to the bottom of the vessel in which the experiment was made. The iron occa- sioned a deep orange precipitate ; but after many weeks, not the smallest portion of copper was found in the water; and so 1824.) Copper Sheeting by Sea Water, &c. 97 far from its surface being corroded, in many parts there was a regeneration of zinc or of iron found upon it. 6. In pursuing these researches, and applying them to every possible form and connexion of sheet copper, the results were of the most satisfactory kind. A piece of zine as large as a pea, or the point of a small iron nail, were found fully adequate to preserve forty or fifty square inches of copper; and this, where- ever it was placed, whether at the top, bottom, or in the middle of the sheet of copper, and whether the copper was straight or bent, or made into coils. And where the connexion between different pieces of copper was completed by wires, or thin fila- ments of the fortieth or fiftieth of an inch in diameter, the effect was the same; every side, every surface, every particle of the copper remained bright, whilst the iron or the zinc was slowly corroded. A piece of thick sheet copper, containing on both sides about sixty square inches, was cut in such a manner as to form seven divisions, connected only by the smallest filaments that could be left, and a mass of zinc, of the fifth of an inch in diameter, was soldered to the upper division. The whole was plunged under sea water; the copper remained perfectly polished. The same experiment was made with iron: and now, after a lapse of a month, in both instances, the copper is as bright as when it was first introduced, whilst similar pieces of copper, undefended, in the same sea water, have undergone considerable corrosion, and sie a large quantity of green deposit in the bottom of the vessel. A piece of iron nail about an inch long was fastened by a piece of copper wire, nearly a foot long, to a mags of sheet cop- per, containing about forty square inches, and the whole plunged below the surface of sea water ; it was found, after a week, that the copper was defended by the iron in the same manner‘as if it had been in immediate contact. A piece of copper and a piece of zinc soldered together at one of their extremities, were made to form an arc in two different vessels of sea water; and the two portions of water were con- nected together by a small mass of tow moistened in the same water: the effect of the preservation of the copper took place in the same manner as if they had been in the same vessel. ' As the ocean may be considered, in its relation to the quan- tity of copper in a ship, as an infinitely extended conductor, I _ endeavoured to ascertain whether this circumstance would influence the results ; by placing two very fine copper wires, one undefended, the other defended by a particle of zinc, in a very large vessel of sea water, which water might be considered to bear the same relation to so minute a portion of metal as the sea to the metallic sheeting of a ship. The result of this experi- ment was the same as that of all the others; the defended New Series, von, vin. H 98 Sir H. Davy on the Corrosion of Copper Sheeting. [Aue. copper underwent no change; the undefended tarnished, and deposited a green powder. ; Small pieces of zinc were soldered to different parts of a large plate of copper, and the whole plunged in sea water: it was found that the copper was preserved in the same manner as if a single piece had been used. A small piece of zinc was fastened to the top of a plate of polished copper, and a piece of iron of a much larger size was soldered to the bottom, and the combination placed in sea water. Not only was the copper preserved on both sides in the same manner as in the other experiments, but even the iron ; and after a fortnight, both the polish of copper and the iron remained unimpaired. 7. I am continuing these researches, and I shall communi- cate such of them as are connected with new facts, to the Royal Society. The Lords Commissioners of the Admiralty, with their usual zeal for promoting the interests of the Navy by the application of science, have given me permission to ascertain the practical value of these results by experiments upon ships of war; and there seems every reason to expect (unless causes should inter- fere of which our present knowledge gives no indications) that small quantities of zinc, or which is much cheaper, of malleable or cast iron, placed in contact with the copper sheeting of ships, which is all in electrical connexion, will entirely prevent its cor- rosion. And as negative electricity cannot be supposed favour- able to animal or vegetable life ; and as it occasions the deposi- tion of magnesia, a substance exceedingly noxious to land vegetables, upon the copper surface; and as it must assist in preserving its polish, there is considerable ground for hoping that the same application will keep the bottoms of ships clean, a circumstance of great importance both in trade and nayal war. It will be unnecessary for me to dwell upon the econemical results of this discovery, should it be successful in actual prac- tice, or to point out its uses in this great maritime and commer- cial country. I might describe other applications of the principle to the preservation of iron, steel, tin, brass, and various useful metals ;, but I shall reserve this part of the subject for another communi- cation to the Royal Society. 1824,] Application of Mathematics to Chemical Analysis. 99 - Artice III. An Application of Mathematics to Chemical Analysis. By Mr. John Davies, M.W.S. Member of the Literary andPhilosophical Society of Manchester, &c. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Manchester, July A, 1824, To determine the quantities of lime and of magnesia when they occur together, has been regarded as a problem of some difficulty ; and though several eminent chemists, who have paid particular attention to the subject, have suggested peculiar methods for the purpose, an accurate and a direct process is, if I mistake not, still a desideratum. It occurred to me a short time ago that the object might be best attained by the aid of calculation, applied in a manner which, though very simple and easy, has not, I believe, been hitherto attempted. The method which will be explained in this paper will furnish another example, in addition to the many already known, of the value of the atomic theory in its subser- vience to chemical investigation. I designate by the name of atomic multipliers those numbers, whether whole or fractional, by which if we multiply the weight of an atom of any base, we shall obtain that of the correspond- ing salt. Now it appears from the table * of chemical equiva- lents, that when the number denoting the weight of an atom of magnesia is multiplied by 3, and that of an atom of lime by 1 ; 2 ; : = we obtain the numbers representing the relative weights of the sulphates of those earths. Suppose, then, that we have a quantity of lime and magnesia weighing together 96 grains, and that, when converted into sulphates, their joint weight is 2651 grains; it is required to determine by calculation the quantity of each earth. Assume « = the quantity of magnesia, and lime. Y= Then « + y = 96, And 3 2 + —y = 2651. Hence x = 56, the quantity of magnesia, and y = 40, that of lime. {f any objection be conceived to arise from the difficulty of procuring the earths in a pure state, it might evidently be obviated by taking the bases in the state of nitrates or any * Henry’s Chemistry, vol. ii, pp. 637 and 638, n 2 100 Application of Mathematics to Chemical Analysis, [Auc. other salts, and then converting them into sulphates. Having determined in this way the respective quantities of the given salts, those of the earths may be deduced by simple proportion. It is easy to get a general formula for all similar cases. Let. the atomic multiplier of any simple body, A, to form a given salt, be a; and that of another, B, 6; and let the joint weight of the simple bodies be m, and that of their salts $ ; the absolute weights of A and B may be found as follows: r+y=m, axc+by=8, from which equations we obtain y = ““~*, and x = = bm. av-b awxnb The preceding question may be readily answered by means of the general formula, the use of which it will serve to illustrate. s—bhm 1856 — 1632 224 eb att, 3 17 Te 4 et hs 56, the quantity of magnesia, as before: and 96 — 56 = 40 = the lime. The algebraical result from the general equation furnishes the following Rule. Multiply the joint weight of the bases by the atomic multi- plier of one of them (A); then. the difference between this pro- duct and the weight of both salts, divided by the difference between the atomic multipliers, will give the absolute weight of the other base (B). The base A may be found by subtraction. The principie upon which the above rule is founded may be extended to three or more bodies. Let a, 6, c, be the multipliers of the sulphates, And a’, U’, c’, nitrates. Then, by denoting the respective quantities of base by 2, y, and z, we have, ai a al {! e+by+cz% au + by + cx Hence the respective values of x, y, and z, may be deter- mined, tl Wl z%* 3 Seatinagi! ES 1824.] Analysis of the Metal of the Statue found at Lillebonne. 101 ArticLe IV. Analysis of the Metal of the Statue found at Lillebonne, near Caudebec, in the Department of the Lower Seine, on an Estate belonging to M. Holley. By M. Vauquelin.* M. VavuQuELIN received a portion of the metal from M. Revers, who described the statue, and a further supply from the proprietor, M. Holley. The whole quantity weighed about 340 grains. Its surface had a slight green coat of carbonate of copper, and some traces of gilding still remained. Internally, there were cavities lined with the green carbonate, and several grains of metallic copper were disseminated through the mass. By treatment with diluted sulphuric acid, the red-brown colour of the metal assumed at once a purple hue, which as the liquor became clear changed to blue. Consequently the metal did not consist wholly of protoxide of copper, as in that case the acid would not have been coloured. Hydrochloric acid was scarcely coloured green by digestion on the residuum ; the solution deposited on cooling crystals of chloride of lead, and a considerable quantity of white proto- muriate of copper. The remainder, which was perfectly metallic, dissolved in nitric acid, leaving a residuum of white oxide of tin. The separate analyses of several small portions of the metal gave the proportion of lead always the same, whence M. Vau- quelin concludes that it is uniformly distributed through the whole mass, and not derived from solder, of which he could not discover any indications on the portions sent to him.+ He supposes the lead to have been contained in the tin, with which the copper was originally alloyed, and that its proportion to the tin is as 1: 4, a proportion very different from that employed to form common solder, but nearly the same as is used by the pewterers for their pewter. It may, indeed, be said that the solder of the ancients was not like ours, and that their pewter contained no lead; but the contrary seems most probable. From the preceding experiments the metal appears to consist of peroxide and protoxide of copper, metallic copper, lead, and oxide of tin. M. Vauquelin found the proportion of the gold derived from the gilding on the piece he received from M. Holley, to amount to rather more than 1-1000th part of its weight, a quantity so small that he considers it could not have been applied by means of mereury, which penetrates to a certain depth into copper, and other metals, when applied to them, and carries a portion of the * Extracted from the Annales de Chimie. + M. Labillardiére, who first examined the metal of the statue, attributes the lead to the solder, 102 M. Labillardiére on the Lillebonne Statue. [Avuc. gold with it, of which there is no appearance below the surface in the Lillebonne statue. It was, therefore, probably, gilded by means of leaf gold, applied without the intervention of mercury, as appears also to have been the case with the Corinthian horses, which were for some time at Paris. “T conceive that it is not necessary to have recourse to the intervention of the gilding to explain the cause of the oxidation of the statue ; the presence of tin and lead appears to me to be sufficient ; moreover, a metal completely gilded, does not form a voltaic pile, since the circle is closed, and the metals are in immediate contact. It is true that in the course of time solu- tions of continuity may take place.* “ Anincipient oxidation at the surface was sufficient alone to effect the oxidation of all the parts of the statue, provided it were in a moist aerated ground. We often find in the earth copper, which externally is in the state of peroxide, internally in that of protoxide, and metallic in the centre. Iron also is frequently seen peroxidated at the surface, and in the state of protoxide in the interior. As soon as oxygen has seized on a metal in a moist place, it is propagated successively towards the interior, like, as it were, a gangrenous point, and is replaced by that at the surface, as is particularly remarkable on iron; the moment a spot of rust is formed on it, it extends in all directions.” To this abstract of M. Vauquelin’s paper, we shall add a note on the same subject addressed by M. Houtou Labillardiére to the Editors of the Annales de Chimie. The subject receives additional interest at the present moment from its analogy to the important question that has for some time occupied the attention of our illustrious countryman, and afforded him another oppor- tunity of exalting the splendour of his own fame, and of benefit- ing his country. Our readers will see in another part of this number of the Annals the details of Sir Humphry Davy’s expe- riments on the means of preventing the action of sea water on the copper sheeting of our ships, and the simple but sagacious train of reasoning which led to their institution. We must confess that M. Labillardiére’s explanation of the oxidation of the Lillebonne statue, is much more satisfactory to us than M. Vauquelin’s. Indeed that gentleman’s hypothesis seems irreconcileable to the fact ; for tin and lead being positive metals with respect to copper, should rather prevent than dap ar its oxidation. ——— i Note on the Lillebonne Statue. By M. Houtou Labillardiére, Professor of Chemistry at Rouen, We cannot, with any probability, suppose that the ancients * M. Labillardiére ascribes the oxidation to the galvanic influence of the gilding. 1824.) M. Labillardiére on the Lillebonne Statue. 1038 formed the Lillebonne statue of matter so friable as that of which it is now composed, since a slight effort is sufficient to break off pieces of it of considerable thickness : it is besides impossible to admit that conclusion, for many parts of the statue have been fixed by rivets ; neither can we imagine that the oxi- dation of the metals, which in some parts is complete, and in others partial, can have been occasioned by any accidental cal- cination that the statue may have undergone. Theory and experience prove that were the oxidation owing to the combined action of heat and air, those parts completely oxidated in which the copper is found in the state of protoxide, ought to be in that of deutoxide. * There is a fact which deserves to be collated with the present subject. Most bronze medallions found under the same circum- stances as the statue, have suffered an analogous alteration, which we may attribute to their having also been gilded (as we know they frequently were), for common medals which were not gilt, though found likewise under similar circumstances, either retain their metallic properties, or pass to thé state of verdigris, like copper utensils exposed to air and moisture. The oxidation of the metals of which the statue was originally formed, is derived from a particular cause ascribable to the galvanic effects produced by the contact of the gold leaf with which one of its surfaces was covered, with the copper or bronze, which forms its basis. We know that two dissimilar metals develope electricity by contact; that they assume different electrical states; and that in the case of copper and gold, the gold becomes negative, and the copper positive. A voltaic pile constructed of those two metals, and having its copper extremity, or positive pole, terminated by a copper wire, and its gold extremity, or negative pole, termi- nated by a gold wire ; if we place these two wires in a vessel of water, and put the pile in action, the water is decomposed, its oxygen goes to the positive pole, and combines with the copper wire, while the hydrogen, being incapable of combining with the gold wire of the negative pole, to which it is determined, flies off in the form of gas. The Lillebonne statue, formed chiefly of copper alloyed with asmall quantity of tin, and covered with leaf gold, may be con- sidered as a voltaic pile, capable of producing the same effects as a pile whose elements consist of gold and copper. The statue having been buried for twelve or fifteen centuries in moist earth, determined the decomposition of the water by galvanic action, like the pile in the preceding case. The oxygen of the decom- posed water went to the copper and combined with it; the hydrogen went to the gilded surface, and from thence escaped into the atmosphere. The number of years that the statue laid 104 M,. Lewenau on Selenium. [Avc. buried allows us to conclude that this action, though siow, has been sufficient to produce such marked effects of oxidation. The same reasoning is applicable to many other phenomena, which are daily occurring before our eyes. It is for this reason, for instance, that we are obliged to attach the copper sheeting of our ships with copper nails, and not with nails made of iron, that the contact of two dissimilar metals may not give rise to an electrical action, which, by the decomposition of the water, would speedily determine the oxidation of the iron, the copper in this case being negative. ARTICLE VY, Extraction of Selenium from the sulphureous Deposits left in the Manufacture of Sulphuric Acid from Pyrites. Translated from the German of M. Lewenau, by M. Robinet.* M. Luwenav has presented a monograph on selenium to the Société de Pharmacie. Having been desired to extract what- ever is interesting and new in the Memoir, I have been occu- pied in examining the work. It gives a complete history of the discovery, properties, and modes of obtaining selenium, con- densing in one view all that is known of this substance, from the several accounts that have been published respecting it, since M. Berzelius discovered it in 1818. But independently of what he has borrowed from others, M. Lewenau’s treatise contains observations which belong to himself alone, and have appeared nowhere else ; they deserve the attention of chemists in general. M. Lewenau has been principally occupied with the methods of preparing selenium, and the following is the process he has adopted. I give it exactly as he has detailed it. “One pound of the deposit was introduced into a tubulated retort, of the capacity of four pints, taking care that none should adhere to the sides ; the retort was placed on the sand-bath, and a large globular receiver, united by a Woulf’s tube to a flask full of water, adapted to it. The apparatus being luted, the acid was introduced, in the proportion of eight pounds of muriatic acid, sp. er. 1°200, to four pounds of nitric acid, sp. gr. 1-500. To avoid the effects of the violent action which suddenly takes place, only a fourth part of the acid was introduced at first, and carefully poured over the bottom of the retort by means of a funnel with a long neck. The mass immediately began to heat and swell up, and to give off a considerable quantity of red vapours. The liquid assumed « dark-grey colour, and * From the Journal de Pharmacie, 1824.] M. Lewenau on Seleniwn. 105 the water in the Woulf’s bottle soon became reddish-yellow. When the action of the acid had moderated, a pound and a half more was added; the same phenomena occurred again, and were followed by a fresh introduction of acid. Next, to complete the action of the acid, and get rid of the now inert liquid, it was dis+ tilled over into the receiver, with a gentle heat; the distillation was accompanied by the disengagement ofa reddish-yellow gas; towards the end of the process, the neck of the retort was lined with small yellow stellated crystals, very probably a binary compound cf selenic and muriatic acid, which disappeared on increasing the heat. When almost the whole of the exhausted liquid was thus separated, the remainder of the acid was intro- duced, in separate portions, as before. The action was always very violent on each addition of fresh acid, and it was necessary several times to change the water in the flask, as it became satu- rated with the acid vapours. At last, all the liquors were returned into the retort andredistilled. The insoluble residuum, and the sides of the retort, appearing of a deep-red colour, as if occasioned by pure precipitated selenium, the solubility of which in fuming nitric acid had been demonstrated by direct experi- ment, a pound and a half of that acid was introduced into the retort, and distilled with a gentle heat till no supernatant liquid remained, but without entirely reducing the residuum to dryness. Distilled water was affused over the residual mass at the bottom of the retort, made to boil, and the whole then poured out and filtered, and the residuum washed, till the washings passed off perfectly insipid. The filtered liquid had a light-yellow colour ; that which had been distilled into the receiver was found to be slightly seleniferous. “In order to separate the selenium from the filtered liquor, in which it existed as selenic acid, without regard to the metals it might contain, sulphite of ammonia, recently prepared, was employed, which threw down the selenium, in the form of large flakes, of a cinnabar-red colour. The colour was proportionately brighter, as the quantities precipitated were smaller. The pre- cipitation was instantaneous, and preceded by slight turbidness for a few moments, when a concentrated solution was acted on ; but if the solution was diluted, precipitation did not ensue for some time, although a large excess of sulphite of ammonia were added, and, which is advantageous in all cases, the liquor, at first clear, became coloured (sometimes at the expiration of many hours), and at last turbid, and deposited selenium. Ina certain state of dilution, the precipitate was black or dark-grey. The selenium thus obtained was washed with cold distilled water, till the washings ceased to precipitate muriate of barytes ; five or six washings are commonly necessary ; the selenium was then dried in the shade. uke “To obtain the small portion that might still remain in the 106 M. Lewenau on Selenium. [Avue. solution from which the selenium was precipitated, it was evapo- rated to two-thirds of its bulk in a retort ; by these means small grey spangles were obtained, possessing a metallic brilliancy, and friable between the fingers: they were metallic selenium, The concentrated liquor, mixed with sulphite of ammonia, afforded a fresh quantity, but this had a dirty-brown colour. The acid products of this distillation, collected in the receiver, not giving any precipitate, nor becoming turbid with sulphite of ammonia, bars of zinc were immersed in it; the liquor being previously divided into several portions, and diluted, to avoid a too violent action: selenium was thus deposited, in dark-grey flakes, with a brisk disengagement of hydrogen gas, of a pecu- liar odour. It is necessary to separate these flakes speedily from the liquor, or they soon disappear. The selenium thus obtained was washed and dried. It must be observed in this operation, that immediately after the precipitation of the sele- nium, the bars of zinc should be removed from the acid, other- wise there is danger that it may mix with the metallic particles; in that case, it is advantageous to wash them with water acidu- lated with sulphuric acid. Finally, it may happen that all the selenium may not be obtained by this method, for zinc does not appear to be capable of precipitating it wholly from the solution. “« By the preceding process, one pound of the sulphureous deposit afforded, in } hes \ Gros. grs. . Grs. troy, Red selenium, precipitated by sulphite a 8 14 == 484-16 ammonia ..... bid) d scinh hpdia iw eahe fue embtara tds 0 0 Dark-grey, obtained Dy FAG yo 6; ara sibs bbe wad eis PRONG itis inthe: eaiamsishe Sahbd maldoiviee mites Ai EOD Rea ANE OWT A | oy 6\0:0j015:0hmjsibjn) ibn sing Heaney i ASE *10 2 = 592-82 “‘ If we compare M. Lewenau’s process with those successively adopted by M. Berzelius, we find it very superior to any of them. In fact, by the old methods, we perform many useless operations for the purpose of freeing the solution of selenium from all foreign substances, in order to precipitate it in a pure state. This mode had serious inconveniences, in consequence of the difficulty of separating the sulphuric acid, and the metallic oxides, without at the same time their carrying with them a por- tion of the selenium. M. de Lewenau avoids this, and at the same time obtains a larger product by simplifying the operation.” * The sulphureous deposit on which M. Lewenau made his experiments, was procured from a sulphuric acid manufactory in Hungary. M. Henri, jun. has repeated the pro- cess on the seleniferous sulphur from Fahlun, and obtained a much smaller proportion of selenium than was obtained by the author.— Note by M. Robinet. > 48 =. 39-67 : 1824.] Mr. Gray onthe Pulmonobranchous Mollusca. 107 ArtTicLe VI. On the Natural Arrangement of the Pulmonobranchous Mollusca. By John Edward Gray, MGS. (To the Editors of the Annals of Philosophy.) GENTLEMEN, July 5, 1824, BeinG dissatisfied with the arrangement of the air-breathing mollusca proposed by Ferrussac in his showy work on the Land and Freshwater Shells, which he appears to have thought imper- fect himself, as he has proposed a new one in one of his late numbers, which I consider to be more artificial, and consequently inferior to his former order, I have sent you a sketch of their circular disposition, which I had considered as the proper linear disposition of them before the publication of Mr. W.S. Macleay’s excellent views. The animals of this order of mollusca are at once distinguished by their closed pulmonary cavity, on the parietes of which the aerating vessels are reticulated. They all breathe free air; for those animals which live constantly. in water rise to the surface to replenish their stock of that fluid so essential to life. They have no operculum, and this latter character at once distin- guishes the shells of this family from the Cyclostomide, which appear to be the connecting family between them and the T'ur- binide. The true land animals of this group, as the slugs and snails, which may be considered as the type, are characterized by their tentacula always heing capable of being withdrawn into them- selves, as the finger of a glove, and by their eyes always being placed on a pedicle capable of similar retraction ; whereas those which are almost constantly found in or floating on the surface of water, as the Land-ears, the Pond and Shield-snails, are fur- nished with contractile tentacula and have their eyes usually sessile at the base of them. The groups of this order may, there- fore, be thus characterized :-— 1. Tentaculis retractilibus, oculis pedicillatis. Terrestres. Mollusca gasteropoda..........eeee00: .e.. LIMACcIDE. sllus a, pallit marginibus in- Mollusca trachelipoda, pallii marginibus ir Haticin CIASSALIS «cece ce se cect pv eccreee ee oees 2. Tentaculis contractilibus. Aquaticee. Mollusca trachelopoda, pallii marginibus in- ; : ‘it A.URICULADA crassatis, teste labio multiplicato ....... } 108 Mr. Gray on the Pulmonobranchous Mollusca, [Awe. Mollusca trachelopoda, pallii marginibus tenui- bus, teste labio sub uniplicato. ........6. Mollusca gasteropoda, pallio scuti-formi. .... ONCHIDIADA. LYMNEAD. The affinity between these families is so close that I shall not have much difficulty in pointing out their connexion one with another. Commencing with the Slugs; they are connected with the Snails by means of the genus Testacella, and indeed it is exceedingly difficult to draw the line of demarcation between the Limacide and the Helicid@ in the present imperfect state of our knowledge with regard to the animals of the latter family. But their shells may be known from those of all the other families by their mouth being closed, when the animal is at rest, by a peculiar membrane which is called an Epiphragma, or Poma. The Snails are connected to the Auriculadé by means of a genus named by Ferrussac, Partula, which has the eyes sessile, as in the latter family, and also has the peculiarity of being ovo-vivi- parous : therefore, we are thus led to the Auriculade, which are mostly aquatic, or at least found in marshes. I should cer- tainly exclude from this family the genera Pyramidella and Tornatelia, which Ferrussac has added to it, and place them in the family Turbinide, for the former has an operculum like the Trochi, formed of many gradually enlarging, and the latter like the Nautica, formed of a few rapidly increasing whorles, and they both have the pectinobranchous animals of the latter group ; but I would retain the genus Pedipes of Adanson, which is said to be marine, in this family, on account of its near affinity to the Aur?- cula nitens of Lamarck (the Voluta triplicata of Donovan), which, like several of this family, is found in salt marshes, or estuaries, and [ would also add to it the Voluta fluminea of Dr. Maton, which, by the peculiar form of its outer lip, may perhaps form a new genus. From this family, by the general similarity of the animals, the general habitat, and particularly by the peculiar form of the shell of Auricula Dombeyana, 1 proceed to the Lymneade, which are all truly aquatic, and usually called Pond Snails, and which, by the addition of the genus Planorbis to the divisions pointed out by me in Sowerby’s Genera, will form a very complete circle. From thence, by means of the much shifted genus Ancylus, we are led to the Onchidiade which only differ from them in being destitute of any shell; and by means of the land section of this family, which Ferrussac has placed with the Limacide, we are led to return to that family, thus completing the circle, which, at another opportunity, I shail attempt further to illustrate. It is impossible, till more is known of the animals of the Snails, to point out distinctly the analogy between the genera of the 1824.] Mr, Chilton on an improved Rain Gauge. 109 families Limacide and Helicide; but as a proof that such ana- logy does exist, I need only observe that Ferrussac has named two of the genera of the latter family Helicarion and Helicolimax, on account of their similarity to the genera Arion and Limax of the former family. ARTICLE VII. Description of an improved Rain Gauge. By Mr, George Chil- ton, Lecturer on Chemistry.* THE quantity of_rain that falls in any particular district being an important item in Meteorology, any improvement in the instruments of observation by which that quantity can be deter- mined correctly must be acceptable to the cultivators of that department of science. In the common construction of the rain gauge several causes of error are manifest, which when taken separately, might be deemed trivial, but whose combined effect is such as every accurate observer must be desirous of avoiding. It is well known that fluids undergo changes in bulk by changes of temperature, as well as by those of barometrical pressure ; and that any mode of measuring the dimensions of a fluid, ex- posed to the influence of these fluctuating causes, provided it does not make due allowance for them, must be erroneous. In addition to these causes of irregularity, the cohesion of the fluid, which is necessarily connected with the measurement by graduated rods, renders it impossible to determine the true height of it. But besides these obvious causes of inaccuracy, the fluid in the common construction of the rain-gauge is too much exposed to spontaneous evaporation. This might, in part, be remedied by narrowing the neck of the funnel, but here another difficulty arises : if the aperture, by which the water enters the gauge be too small, the funnel, in a smart shower, might be filled to over- flowing ; by which a part of the water would be lost. The following is a description of a rain gauge constructed on principles, by the help of which, the quantity of rain that falls into it can be accurately determined in inches of altitude with~- out being affected by the causes of error alluded to above, An essential part of the rain gauge is a prismatic vessel, figs. 1 and 2 (see p. 113), whose top and bottom are, each 10 inches square, inside measure, with any convenient height. This is all that is necessary for occasional experiments, as for instance, to determine the quantity of rain, snow or sleet, that may fall in winter when the evaporation is inconsiderable ; or * American Journal of Science. 110 Mr, Chilton on an improved Rain Gauge. [Ave. the quantity of rain that falls in a single shower, at any other season. But to answer all purposes, it must be provided with a cover, in the centre of which is inserted a funnel, whose top has the same area as that of the top or bottom, of the prismatic vessel above. To prevent evaporation, the orifice of the funnel is furnished with a valve against which a weak spring, attached to the inside of the cover, presses with a force just sufficient to close it, but which is overcome by the weight of a few drops of rain. It is evident that in a shower the water will open the valve, and after it has passed into the body of the gauge, the valve will close the orifice again, suffering, however, the drain- ings of the funnel to pass along the pendant wire by cohesive attraction. This top, with its funnel and appendages, may be fitted on the body of the gauge, like the lid of a common tea-canister. The water being thus introduced into the gauge, the method of determining its altitude in inches and decimal parts depends upon the following fundamental statements, in connexion with the simple operation of weighing the water in the gauge. Fundamental Principle. A cubic inch of distilled or rain water, under a medium pres- sure and temperature, weighs 252°525 grains, according to the Jatest corrections. Now this number, multiplied by 100, the area of the funnel, in square inches, or that of tue top or bottom of the body part of the gauge, gives 25252°5 grains for the weight of 100 cubic inches of water. Supposing this quantity of water in the gauge, it would evidently form a stratum on the bottom of one inch in height; and if we conceive this stratum to be divided by horizontal sections into 100 equal parts, these parts would form strata, each of which would be the —!,th of an inch in height ; and, being equal to a cubic inch, would weigh 252°525 grains. Let us further suppose that one of these strata is subdivided into 10 equal parts by sections in the same direc- tion, each of these parts would evidently forma stratum of water, whose height would be only the -,,th part of an inch; and being equal to the 10th part of a cubic inch, would weigh 252525 grains. Having then the weight of 100 cubic inches corresponding to one inch in altitude ; the weight of one cubic inch to the -4,th of an inch; and the ~,th ofa cubic inch to the ,,4,,th part of an inch ; it is easy to see that the height of the water in the gauge may be obtained by making one or other of the above numbers a divisor to the corrected weight of the water, in troy grains. But aus trouble is rendered unnecessary by the use of the following tables :— 1824.] Mr. Chilton on an improved Rain Gauge. 111 TABLE 2. For reducing Avoir- TABLE 1. Troy Weight. dupois Weight. Grains. Troy grains. One pound troy, = 5760 | One pound avoir- One ounce, = 480 dupois, = 7000 One drachm, = 601! Half pound, = 3500 One scruple, = / 20) of a pound, = 1750 Two ounces, = 875 One ounce, = 04570 Half ounce, = 218°75 Quarter ounce, = 109°375 TABLE 3. Corrected weight of Corresponding alti-|| Corrected weight of |Corresponding alti- water in grains troy.|__ tude in inches. water in grains troy.| tude in inches. 25°2525 0-001 2525°250 0:10 50°5050 0-002 5050-500 0:20 75°7575 0-003 7575°750 0-3 101-0100 0-004 10101-000 0-40 126-2625 0-005 12626250 0:50 151°5150 0-006 15151-500 0-60 176°7675 0°007 17676°750 0:70 202-0200 0-008 20202000 0-80 227°2725 0-009 22727-250 0-90 252°525 0-010 25252°500 1-00 505-050 0-020 50505-000 2-00 7397°575 0-030 | 75757:600 3°00 1010-100 0-040 101010:000 4:00 1262-625 0-050 126262-500 5:00 1515°150 0 660 151515-000 6:00 1767:°675 0-070 176767-500 7:00 2020200 0-080 202020-000 8:00 2272°725 0-090 227272°500 9:00 252525°000 10-00 An Example showing the Use of the Tables. Suppose the weight of the water in the gauge corrected by subtracting the weight of the gauge, to be 20lb. 54 ounces avoirdupois, required the height or number of inches of rain ? 1 lb. = 7000 grs. which x 20 = 14000 1. From Table 2. | 4 oz. — 1750 lb. oz. 1 do. = 437°5 20 5+ — aa do. — 21875 The sum = the weightin grs. 142406:25 112 Mr. Chilton on animproved Rain Gauge. [Aue. 2. If the weight, reduced to grains, be found in Table 3, the corresponding height will be found opposite to it in the adjoining column ; but as, in this example, it is not, take the nearest, less, number to it from the table, and subtract it from the weight of the water, marking the corresponding height in inches, &c. Enter the table a second time with the difference and take the nearest /ess number to ¢¢, together with its correspondent height, which subtract from the difference, and with the remainder enter the table again, if necessary, thus, Corres- Weight of water pondent in grains. height. The nearest number in the table, less than 142406:25, which must be subtracted, is.......2.++. 126262°5 500 Diereneeic ing cn qisses'® hea ceulek 16143:75 The next number in the table, less than the GUIBEONCG, IS... eSer ee ye cvagesaseagar LOLOL a 0:60 —_— which, when subtracted, leaves the re- mainder . eeentevoeevevn eevee eeeevre eee eee e es 992:95 The nearest number corresponding to the remainder in the table, is. ..........-. lOLO1] 0-04 The sum of the corresponding heights gives...... Inches 5-64 It is obviously not necessary to be restricted to either the form or the size of the above described gauge. If the cylindrical form be thought to possess any advantages over that of a square prism, it is easy to find the diameter of a circle whose area shall be equal to 100 square inches, by the well-known rule, viz. d = \/ sare where d represents the diameter, a the area, and *7854 the area of a circle, whose diameter is unity. If any other size should be thought more convenient, as, for instance, one whose area is only half of that of the above-described gauge, the same rule, if cylindrical, will give the corresponding diameter, or ifa square-mouthed one be preferred, the side of the square is obtained by extracting the square root of fifty. But it must be remembered that whatever relation the area we pitch upon may bear to 100 square inches, the same relation will subsist between the final result, and that which is given by the tables : thus ifthe area of the gauge be fifty square inches, as this is the half of 100, we must take half the sum of the tabular heights for the true altitude. ‘It is not necessary to be very particular in the choice of a balance ; a pair of good common scales will answer, with true weights, either troy or avoirdupois. The gauge may be made of 1824.] Mr. Chilton on an improved Rain Gauge. 118 tin, or sheet iron painted or japanned, but copper is more dura- ble. The area of the funnel, ‘and that of the top of the body part, are the only parts that need attention in the construction. These ought to be made tolerably exact. A strong hoop should be fixed around them on the outside to preserve their figure true. In every operatior of weighing, the weight of the gauge, moistened in the inside, must be deducted from the gross weight; the remainder is the corrected weight of the water with which the tables must be entered. In the case of hail, snow, sleet, or frozen water, being in the gauge, it is not necessary to melt its contents into water, as the changes effected by temperature and pressure make ro differ- ence in the weight. The use of scales and weights may be dispensed with, by sub- stituting a steelyard, so constructed that the movable weight on its arm might indicate by its position, not the weight, but the inches and decimal parts of its corresponding altitude, without reference to the tables, and without calculation. The advantages of this method of finding the quantity of rain in linear inches of altitude, will be appreciated by adverting to the circumstance of our having a tangible quantity, as an unerr- ing guide to that which is nearly imperceptible. Twenty-five grains and a half, a sensible quantity in a good balance, point- ing out the difficultly visible division of the —,',,th part of an inch. Suppose the problem reversed ; that the cubical contents of the water, or its weight, were required, from the observed altitude. ‘Tne chances of error would all be against the accuracy of such a determination. The ditficulties of the task, indepen- dently of the aforementioned causes of variation, would evidently be insurmountable. I had a gauge constructed on this principle, twelve or fourteen years ago, for my friend Dr. Akerly, who informs me that it answered the end extremely well. This testimony in iis favour is not among the least of those considerations that have induced me to make it more generally known. G.C. Fig. 1. Fig. 2. (0. In ches_—_—_—. New Series, VOL. Vill. 1 114 Mr. Brooke on Baryto-Calcite. [Aue. Fig. 1, represents the rain gauge in perspective. Fig. 2, is a vertical section. G the body of the gauge, F its funnel, L the lid or cover, » the valve, hinged to the lower orifice of the funnel, s the spring to close the valve, wa wire to conduct the drainings of the funnel into the body of the gauge. * Articte VILL. On Baryto-Calcite. By H. J. Brooke, FRS. &e. (To the Editors of the Annals of Philosophy.) GENTLEMEN, July 15, 182A. Mr. Broventon, before he left London, favoured me with specimens of a mineral from Cumberland which had been con- sidered to be carbonate of barytes, but it was very evident that the crystals did not resemble the ordinary figures of carbonate of barytes, and the substance was, therefore, regarded by Mr. Broughton as something new. The external surface of the specimens is coated with sulphate of barytes ; but the internal mass frequently contains cavities which are lined, and nearly filled with crystals. The primary form of these is an oblique rhombic prism, as shown in the annexed figure, the cleavage being parallel to the planes P, M, and M’. on Mor Me eas Ue, Be Sy Fe a oe eR oe PO he kc ee POM are EVE nt olen See's aay DE ee ge) ile ghinae hiapee gant 143 27 All the crystals I have seen are modified on some of the edges and angles, and are lengthened in the direction of the edges of the modifying planes, presenting the character of prisms termi- nated by the bright planes P, a, M, and h, of the figure. The modifying planes are, however, so numerous, irregular and dull in my specimens, that I have not obtained sufficiently good or corresponding measurements to enable me to ascertain their character, and they are, therefore, omitted in the drawing. The mineral is translucent with a slight tinge of a yellowish- brown colour. Its lustre rather more waxy than carbonate of barytes. Its hardness is between that of carbonate and fluate of lime. Its specific gravity, as ascertained by Mr. Children, is 3°66. The name baryto-calcite has been given from its chemical composition, as ascertained by Mr. Children. * The mean specific gravity of carbonate of barytes and carbonate of Itme is 3°5.—C ee. ee ee ss ae Ss a 1824.] Chemical Examination of the Baryto-Calcite. 115 Chemical Examination of the Baryto-Calcite. By J. G, Chil- dren, FRS. &c. With the blowpipe this mineral exhibits the following cha- racters. In the forceps, in the oxidating flame, it neither fuses nor decrepitates ; its surface becomes green, and the point of the flame, beyond the assay, assumes a light greenish-yellow colour. In the reducing flame the superficial green colour disappears. The assay, after being ignited, browns moistened turmeric paper. Heated to redness, in a glass tube, it merely gives off a little moisture. By heat the assay becomes strongly phosphorescent, shining with a pale-yellow light, very similar to that of the common glow-worm. With soda, on the platina wire, in the ovidating flame, it gives a bluish-green opaque mass. Inthe reducing flame the green colour is discharged. With borax, in the oxidating flame, dissolves readily into a perfectly diaphanous globule of a beautiful light amethystine colour. The globule retains its transparency in the reducing flame, but entirely loses its colour. With salt of phosphorus, dissolves very readily ; the globule is perfectly transparent, and in the oaidating flame yellow while hot; when cold, colourless. In the reducing flame the globule is colourless, and, while hot, transparent ; when cold, its trans- parency is slightly disturbed. Analysis. To ascertain the proportions of its elements, I dissolved the mineral in muriatic acid, diluted the solution very largely with distilled water, and precipitated the barytes by sulphate of ammonia ; boiled the precipitate to take up any sulphate of lime that might have been thrown down, filtered, and washed. the precipitate, till the washings ceased to give any cloud with oxa- late of ammonia, adding the washings to the solution from which the sulphate of barytes had been separated. The solution, being first reduced by evaporation, was then boiled with a solution of carbonate of potash, which threw down the lime in the state in which it originally existed in the mineral. Treated in this manner, 20 grs. gave Grains. Sulphate of barytes 15°55 grs.=carbonate of barytes 13-18 Carbonate Of lime... ..cs..cbevcccecsevevsveves O72 19-90 A minute portion, not exceeding one or two-tenths of a grain, 12 116 Transmission of Electricity through Tubes of Water. [Ave.- remained undissolved, and consisted chiefly of sulphate of barytes. Traces of iron and manganese were also obtained, as previously indicated by the blowpipe, but I could not detect any appearance of magnesia. The mineral effervesces of course very strongly with acids, and, when finely pulverised, its powder has a very light flesh-coloured or rosy tint. According to Brande’s Table of Prime Equivalents, the weight of the atom of carbonate of barytes is to that of carbonate of lime as 100: 50, or as 2: 1. The theoretical composition of this mineral, therefore, (disregarding the insoluble sulphate, and the metallic oxides, as not essential to it) accords very nearly with that obtained by experiment, as appears below : Theoretical. Experimental. Carbonate of barytes........+. 66°66 ...... 65°90 Carbonate of lime. ............ 33°33 ...... 33°60 99-99 99-50 Hence we may consider it as containing an atom of each element. ARTICLE IX. On the Transmission of Electricity through Tubes of Water, &c. By Mr. Lewthwaite. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Rotherhithe, July 9, 1824. ALLOW me to intrude myself on your pages to correct an error committed by Mr. Woodward in the last number of the Annals. Mr. W. says, the effects of electricity on loose gunpowder when transmitted through tubes of water, were communicated by me to Mr. L. some time previous to the publication of his letter. The natural inference to be drawn from this sentence is, that I am indebted to him for the experiment in question. This, I can assure Mr. W. is not the case; it was originally communi- cated to me by Mr. Tuther about fourteen years ago. The experiment relative to the conducting power of ether, alcohol, and acids, published in the Institution Journal, originated while I was experimenting with the water tube, nor had I the least idea that Mr. W. was investigating the conducting power of those fluids until some time after the publication of my letter. I am, Gentlemen, your humble servant, Joun LEwruwalTeE. P. 8. An account of the experiment of firing loose gunpowder by the water tube may be found in Imison’s Elements of Science and Arts, vol. i. p. 469, —— ee ee ee 1824.] Nature of the Acid and Saline Matters in Animals, 117 ARTICLE X. On the Nature of the Acid and Saline Matters usually existing in the Stomachs of Animals. By William Prout, MD. FRS.* Tar a free, or at least an unsaturated acid usually exists in the stomachs of animals, and is in some manner connected with the important process of digestion, seems to have been the gene- ral opinion of physiologists till the time of Spallanzani. This illustrious philosopher concluded, from his numerous experi- ments, that the gastric fluids, when in a perfectly natural state, are neither acid nor alkaline. Even Spalnneaci however, admitted that the contents of the stomach are very generally acid ; and this accords not only with my own observation, but with that, 1 believe, of almost évery individual who has made any experiments on the subject. With respect to the nature of this acid, very various opinions have been entertained. Some of the older chemists seem to have considered it as an acid, sui generis; by others it was supposed to be the phosphoric, the acetic, the lactic acid,} &c. No less various have been the opinions respecting its origin and use ; some supposing that it is derived from the stomach itself, and is essential to the digestive process ; others, that it is derived from the food, or is a result of fermentation, &c.; in short, there seems to be no physiological subject so imperfectly understood, or concerning which there has been such a variety of opinions. The object of the present communication is to show, that the acid in question is the muriatic acid, and that the salts usually met with in the stomach are the alkaline muriates. As to the origin and use of these principles, as well as the occasional appearance of other acids, &c. in the stomach, I reserve what I have to say on these subjects till a future opportunity, and shall merely remark at present, that the facts now adduced seem to be intimately connected, not only with the physiology and patho- logy of the digestive process, but with other important animal functions. Having ascertained the circumstances above-mentioned in a general manner, and by means which it would be here unneces- sary to detail, an attempt was made to contrive some unexcep- * From the Philosophical Transactions for 1824, Part I. + After I had discovered the principal fact related in this paper, I was surprised to find how nearly Scopoli had come to the same conclusion. He did not indeed come to the conclusion, as far as I can ascertain, that free muriatic acid exists in the stomach, but he advanced the opinion, that the muriatic acid, in union with ammonia, found in such abundance in the stomach of ruminating animals, is secreted by that organ itself. The only account of Scopoli’s experiments I have seen is in Johnson’s Animal Che- mistry, 1. 183, 118 Nature of the Acid and Saline Matters in Animals. [Ave. tionable method by which their truth might not only be satis- factorily demonstrated, but at the same time that the relative quantities of the different principles might be determined : after various attempts, the following processes were adopted for these purposes, The contents of the stomach of a rabbit, fed on its natural food, were removed immediately after death, and repeatedly digested in cold distilled water till they ceased to impart any thing to that fluid. The whole of these different portions of fluid, which always exhibited strong and decided marks of acidity, were then intimately mixed together, and after being allowed to settle, were divided into four equal portions. 1. The first of these portions was evaporated to dryness in its natural state, and the residuum burnt in a platinum vessel; the saline matter left was then dissolved in distilled water, and the quan- tity of muriatic acid present determined by nitrate of silver in the usual manner ; the proportion of muriatic acid in union with a fixed alkali, was thus determined. 2. Another portion of the original fluid was supersaturated with potash, then evaporated to dryness, and burnt, and the muriatic acid contained in the saline residuum determined as before. In this manner the fotal quantity of muriatic acid present in the fluid was ascertained. 3. A third portion was exactly neutralised with a solution of potash of known strength, and the quantity required for that purpose accurately noticed. This gave the proportion of free acid present ; and by adding this to the quantity in union with a fixed alkali, as determined above, and subtracting the sum from the total quantity of muriatic acid present, the proportion of acid in union with ammonia was estimated. But as a check to this result, the third neutralised portion abovementioned was evaporated to dryness, and the muriate of ammonia expelled by heat, and collected. The quantity of muriatic acid this con- tained was then determined as before, and was always found to represent nearly the quantity of muriate of ammonia as before estimated; thus proving the general accuracy of the whole experiments beyond a doubt. 4. The remaining fourth portion of the original fluid was reserved for miscellaneous experiments, and particularly for the purpose of ascertaining whether it con- tained any other acid besides the muriatic. The experiments abovementioned seemed to preclude the possibility of the pre- sence of any destructible acid; and the only known fixed acids likely to be present were the sulphuric and phosphoric; the muriate of barytes, however, neither alone, nor with the addition of ammonia, produced any immediate precipitate,* showing the * It may be proper to remark, that ammonia, after some time, caused a flocculent precipitate, consisting of the earthy phosphates in union with vegetable and animal mat- ter, and that after combustion, traces of sulphuric acid, the result of that process, were very perceptible. But it is evident, from the experiment related in the text, that nei- ther of these acids previously existed in the original fluid in a free state. 1824.] Mr. Gray on Papilionde. 119 absence of these two acids in any sensible quantity, and still further confirming the results as before obtained. In this manner the three following results, selected from a variety of others of a similar nature, were obtained, No, 1. | No. 2. | No, 3. grs. grs, grs. Muriatic acid in union with a fixed alkali* ,.| 0°12 | 0°95 } 1:71 —————_—_—— _ with ammonia ......| 1°56 | 0°76 | 0:40 —__——_—— ina free or unsaturated state. .| 1°59 | 2°22 | 2:72 Total | 3-27 | 3-93 | 4-83 These results then seem to demonstrate, that free, orat least unsaturated muriatic acid in no small quantity exists in the stomach of these animals during the digestive process; and I have ascertained, in a general manner, that the same is the case in the stomach of the hare, the horse, the calf, and thedog. I have also uniformly found free muriatic acid in great abundance in the acid fluid ejected from the human stomach in severe cases of dyspepsia, as the following examples show. The original quantities of the fluids operated on of course were various, but for the sake of comparison they are reduced, in the following table, to one pint, or 16 fluid ounces, which quantity, in three instances (selected from many others), was found to contain of No. 1.| No, 2.} No. 3, gts. | grs. | grs. Muriatic acid in union with a fired alkali... .}12°11)12-0 {11-25 ——-— with ammonia} ....++| 0:0 | 0:0 | 5:39 —— ina free or «unsaturated state ..| 5°18) 4:63) 4:28 Total |17-24|17-03'20-92 ArxticLe XI. On the Arrangement of Papilionide. By J. E. Gray, MGS. (To the Editors of the Annals of Philosophy.) GENTLEMEN, July 7, 1824, Mr. F. Cuvier has observed that sufficient attention has not been paid by modern naturalists to the works of Linneus, and * For the sake of analogy, the chlorine, in union with the basis of the jived alkali, is reduced in this table and the following to the state of muriatic acid. + Ihave never in more than one instance (No. 3, of the above table) been able to detect any sensible quantity of the muriate of ammonia in the fluids ejected from the human stomach ; and upon inquiry of Sir Astley Cooper, who was kind enough to fur- nish me with the fluid for examination, I was informed that the patient was in the habit of frequently taking ammonia as a medicine, 120 Mr. Gray on Papilionide. [Auc. there is a great deal of truth in this remark ; for it is too much the fashion to abuse without consulting them. The fact is indeed fully verified in the butterflies which Linneus divides into five groups, the Equites, Heliconii, Danai, Nymphales, and the Phebeji, which could only have taken place by his secretly observing their habits, according to his own maxim, for his cha- racters are only taken from their size, colour, and the difference of the edge of the wing. Latreille has divided this family from their manners and habits into exactly equivalent groups, only placing the Danai between the Equites and the Heliconii, and placing the second section of the Plebeji in a family by them- selves under the names of Hesperiade. I have observed that whenever a group formed a good linear series, the two ends would meet, and thus form a circle, by which fact I have convinced several persons who have been disposed to doubt the truth of the circular disposition of nature. Thus we find that several series forms circles which their authors never appeared to have the slightest idea of. It is so with the slight alteration proposed by Latreille with regard to the Papilionide ; and the Linnean position of the Hediconii in them is similar to his position of the Cetacea in Mammalia; it prevented the continuance of the series, and thus obscured their natural disposition. In the Equites and the Danai, the larve are long and cylindri- cal, and the chrysalis is angular, and inclosed in a kind of case, or suspended by a transverse thread ; in the former of these, the lower pair of wings are generally extended at their hinder angles into a tail, in the males at least, and in both they are furnished with aconnecting nerve. From the latter of these groups by means of some of the Pontie of Fabricius as P. sinapis, we pass to the ‘Heliconti and the Nymphales, in both of which the chrysales are suspended without any case by their hinder extremity, and their front pair of legs are folded up, in the males at least, so as to be useless in walking, and the lower pair of wings, like the Danai, are usually destitute of tails and connecting nerve. From these last, by means of the genus Libithea of Fabricius, we pass to the Plebeji, where the larva and pupa are short, and the latter is inclosed in a case, and where the lower wings are destitute of any connecting nerve, but are often provided with several tails ; from these we may return to the Equites, for this last group has the cased pupa and the tailed wings of that tribe, and some of them appear to have a very great affinity to it. The Hesperiade has very great affinity to the Plebeji, of which Linneus regarded them as a section, but I am inclined to consi- der them as the osculant group between the Papilionide and the Spingide, excluding from it the genus Urania, which appears to be the osculant on the other side between the Papilionide and the day-flying Phalenide, but adding to the Hesperiade the genera Castnia of Latreille, and Agarista of Leach. 1824.) M. Berzelius on the Decomposition of Silica. 121 ArTIcLE XII. On the Results of some Chemical Analyses, and the Decomposition of Silica.* In an Extract of a Letter from M. Berzelius to M. Dulong.+ ......l HAVE undertaken some experiments on uranium, in order to determine certain points which M. Arfwedson had left undecided in his excellent memoir on that metal. You are pro- bably unacquainted with that work, though it well deserves to be known. Arfwedson has found the means of obtaining metal- lic uranium ; he has studied its properties, and determined the composition of its oxides. With respect to the yellow oxide, however, his results are not always invariable. I have resumed the inquiry, and have completed the analysis of the uranite of Autun, which I find isa double subphosphate of lime and yellow oxide of uranium. It contains, besides, the phosphates of barytes, magnesia, manganese and ammonia. ‘The green uranite from Cornwall is a similar compound, except that the lime is replaced by an equal number of atoms of oxide of copper. It is, therefore, a double subphosphate of copper and uranium, iso- morphous, but not identical with the uranite from Autun. I have examined the combinations of acetic acid with oxide of copper, in consequence of the analyses of those compounds published by Mr. Phillips. I have found no less than five dif- ferent acetates of deutoxide of copper, in which the multiples of the base are, 1, 14, 2, 3, and 72}; the third is the blue verdi- gris; but as it is decomposed either by cold water, or by a heat of 60° centigrade (140° Fahr.), I consider it to be composed of neutral acetate, and hydrate of copper. You will see the reasons which have induced me to form this conclusion more fully stated when you receive my memoir. During the last six months I have been occupied on a great work on fluoric acid. One part is already printed in the Me- moirs of our Academy ; another is finished, but not yet pub- lished. I have examined the combinations of fluoric acid with bases, and have discovered that what were taken for fluates are double salts. I have analyzed fluo-silicic gas, and its com- pounds with bases. They are all formed in the same manner, and contain a quantity of fluoric acid combined with the silica, equal to twice the quantity combined with the base. Fluoric acid gives analogous compounds with the acids of titanium, colum- * From the Annales de Chimie. + A letter to Sir Humphry Davy on the same subjects, from M. Berzelius, was read before the Royal Society, May 20. (See Annals of Philosophy, vol. vii. p. 458.) ¢ A very extraordinary multiple, and probably a mistake; but so it is given in the Annales de Chimie.—C. 122 M. Berzelius on the Decomposition of Silica. [Ave. bium, tungsten, molybdena, chromium, selenium, antimony, and arsenic; with the hyposulphurous and sulphurous acids, and probably with the phosphorous and hypophosphorous; but I have not yet examined the latter. Fluoric acid is one of the most convenient reagents for the analysis of inorganic substances, since it dissolves every thing that is not attacked by the other acids. It has enabled me to determine more accurately the weights of the atoms of many of those substances about which I was still in doubt. To extract alkali from minerals, it is sufficient to treat them with fluoric acid, or a mixture of fluate of lime and sulphuric acid. In attempting to reduce fluoric acid by potassium, | have succeeded in reducing silica, zirconia, and the other earths, but I have only been able to insulate siliclum and zirconium, The rest decom- pose water with great energy. Pure silicium is incombustible, even in oxygen gas. Itis not attacked by water, nitric acid, nor aqua regia, nor by caustic potash; but fiuoric acid has a slight solvent action on it, particularly with the addition of nitric acid. It does not decompose saltpetre, unless in a yery intense fire, but it detonates with carbonate of potash at an incipient red heat: carbonic oxide gas is disengaged, and charcoal set free, When silicium is heated with nitre, if a morsel of dry carbonate of soda be plunged into the mixture, detonation immediately ensues, By passing the vapour of sulphur over silicium heated to redness, the metal suddenly becomes incandescent. If the combination be complete, which seldom happens, the compound appears as a white earthy mass; it decomposes water with extreme rapidity, the water dissolves the silica and sulphuret- ted hydrogen gas is evolved. In this way we may obtain so concentrated a solution of silica in water that it thickens and coagulates during evaporation, and lets fall portions of that earth in the form of a gummy transparent mass. Siliciuret of potassium, heated with sulphur, burns vividly, and leaves, when dissolved, pure silicium. In chlorine, silicium takes fire at a red heat, and there is formed a colourless, or slightly yellow liquid, with an odour similar to that of cyanogen, extremely volatile, and which sets with water and deposits gelatinous silica. I have not yet examined how silicium conducts electri. city and heat, nor its specific gravity, &c. Nothing is easier than to procure this substance; the following is the method I have adopted :—The double fluate of silica and potash, or soda, heated nearly to redness to drive off the hygrometric water, is put into a glass tube, closed at one end. Bits of potassium are added and mixed with the powder by fusing the metal and gently rapping the tube. It is then heated by the spirit-lamp, and before it is red-hot a feeble detonation ensues and the silicium is reduced. ‘The mass is suffered to cool, and then treated with water as long as it dissolves any thing. Hydrogen 1824, ] On the Mineral Waters of Carlsbad. 123 gas is at first evolved, in consequence of siliciuret of potassium having been formed, which cannot exist in water. The washed substance is a hydruret of silicium, -which, at a red heat, burns vividly in oxygen gas, although the silicium is not thereby com- pletely oxidated ; it is then heated in a covered platina crucible, the heat being slowly raised to redness. The hydrogen alone is oxidated, and the silicium is now no longer combustible in oxy- gen ; but chlorine attacks it readily. The small portion of silica that is formed may be dissolved by fluoric acid. If silicium has not been exposed to a strong red heat, the acid dissolves it, with a slow disengagement of hydrogen. According to my synthetical experiments, silica contains 0°52 of its weight of oxygen. Zir- conium is obtained by an analogous process. It is as black as charcoal, is not oxidated either by water or muriatic acid, but aqua regia and fluoric acid dissolve it; the latter with disen- gagement of hydrogen. It burns with extreme intensity at a slightly elevated temperature. It combines with sulphur. Its sulphuret is chesnut-brown like silicium, insoluble in muriatic acid and the alkalies, It burns brilliantly, and the products are sulphurous acid gas and zirconia. ARTICLE XIII. On the Mineral Waters of Carlsbad. By Jac. Berzelius.* CARLSBAD is situated in a deep and very narrow valley, not far from the place where the latter terminates in the valley of the river Eger. Through the middle of this spot, there flows the little river Tepel, on both of whose banks, and within a short distance from one another, the hot springs first issue from the earth. The springs themselves are extremely numerous, but those resorted to by the strangers at Carlsbad are only the fol- lowing; the Sprudel, the Hvgeian spring, the Mull spring (Mihlbrunn), the New spring (Neubrunn), the Empress There- sa’s spring (Theresienbrunn), St. Bernard’s spring (Bernhards- brunn), and, but much seldomer than the others, the Hospital spring (Spitalsbrunn). All of them issue from a species of limestone, and into each of the outlets there has been inserted an artificial pipe, through which the water, impelled by the internal pressure, is thrown up into the air in an uninterrupted jet, in a manner very convenient for those who drink it. This limestone is formed by the water itself; for the latter, in proportion as it loses carbonic acid, is incessantly depositing a concretion of a compact and crystalline texture, on every substance with which it Comes in contact. * Abridged from the Kongl, Vet, Acad, Handl, 1822, p. 139. 124 M. Berzelius on the fAue. About the commencement of last century (in the years 1713 and 1727), this calcareous incrustation was suddenly burst open in consequence of the accumulated pressure from within, and the hot water flowed down immediately into the river Tepel. It was determined at that time to bore through the limestone, partly with a view to investigate the cause of these eruptions, and, if possible, to obviate the recurrence of a similar accident, and partly also with the hope of discovering the source in which the apparently inexhaustible supply of water originates. Scarcely had the external crust been broken, when the water rushed out with great violence, and numerous cavities were discovered under it, all of them filled with water, and the partitions be- tween which rested upon a thick calcareous incrustation, simi- lar to the one already penetrated. This also was broken through, and cavities were found beneath it, of exactly the same nature with those already described; all of them full of water, which was discharged from them with a still greater degree of force, and having another calcareous incrustation for their basis. The opening of the third vault disclosed an immense reservoir of water, which on its first discovery received the name of the Sprudelkessel. These three calcareous layers were in all from one to two yards in thickness, and consisted of a hard body, sometimes alabaster-white, sometimes brownish-coloured and striped, which commonly received the name of Sprudel-stone. They did not rest over one another in a regular concentric man- ner, but constituted numerous unequal cavities, which were separated by the intervening partitions: so that their general arrangement approached considerably to what would be exhi- bited by a number of flat basins of different sizes, when turned upside down, and heaped in an irregular manner over one another. The water in this reservoir was in a state of violent ebullition, and the copious volumes of hot steam which rushed through the opening made in it, completely prevented an accu- rate determination of its extent. Its depth from the outermost crust of limestone was estimated to be between three and four yards, after making allowance for the irregularities of its bot- tom; but it could not be fathomed in any direction by a rod 60 yards in length, and pushed forwards horizontally. Indeed, its great extent may be judged of pretty accurately from the cir- cumstance, that in the greater part of the little town of Carlsbad, one cannot dig to any considerable depth, without meeting the calcareous shell, and when this is penetrated, the hot water instantly rushes up with its customary impetuosity. In many places the carbonic acid gas makes its way through natural clefts in the limestone, in such abundance, as to fill the cellars of the houses ; and in the river Tepel (which flows to some dist- ance immediately over the reservoir), particularly in the neigh- bourhood of the Sprudel, there may be observed a constant 1824.] Mineral Waters of Carlsbad. 125 succession of air bubbles rising to the surface of the water. The openings made in the course of this examination were built over wit mason work, every joint of which became speedily stopped up with the carbonate of lime deposited by the water. It still continues to retain the water completely, and to constrain it to flow through the pipes, which have been placed in the reservoir. These pipes also become by degrees incrusted with the sprudel- stone, and must be cleared four times every year to prevent their being clogged up altogether. What is called the Sprudel is merely an opening in the reser- voir, from which, however, the water rises only at intervals, in such a manner that air and water are discharged from it alter- nately. This remarkable phenomenon is occasioned by the car- bonic acid gas, which gradually accumulates in the upper vault of the reservoir, and which, owing to the diminished pressure, the water is constantly emitting, in proportion as it recedes from the interior of the earth. This gas, having no means of exit, of necessity reacts upon and presses down the expanse below, until it at last escapes through the canal which, until then, had fur- nished a passage for the water. Hence air and water are dis- charged through the opening successively, in proportion as the elasticity of the gas accumulates and is expended.* This alter- nation takes place at the Sprudel 18 or 19 times every minute. There are many other openings in the immediate neighbourhood, from which the water is discharged even in greater abundance ; but it proceeds from them all in an uninterrupted stream. The quantity of hot water which flows from these springs is altogether astonishing. Many attempts have been made to es- timate it; but all of these are of so indirect a nature, that they do not deserve to be regarded as even approximations to accuracy.} Analysis of the Water. The water employed for this analysis was taken from the Sprudel, and was preserved in bottles furnished with ground glass stoppers, in order to prevent the diminution in the quan- tity of oxide of iron, which is always occasioned by a common cork. The Carlsbad wateris clearand colourless. When newly drawn its taste resembles that of weak chicken broth, but after some hours it becomes unpleasantly alkaline. It has no peculiar smell, nor can any reagent detect in it the minutest trace of sul- * An ingenious illustration of a similar natural intermitting spring will be found towards the conclusion of the introductory portion of the article Steam Engine, by Prof. Robison, in the Encyclopedia Britannica; or in his System of Mechanical Philosophy, edited by Dr. Brewster, vol. ii. p. 43. + Klaproth’s estimation of this quantity is certainly twenty times toohigh. From a measurement made on the spot, Noy. 1, 1811, it was calculated that the Sprudel and the Hygeian spring alone discharge 1923 millions of German cubic feet of water every 24 hours, 126 M. Berzelius on the [Ave. phuretted hydrogen. After being kept for some time in close vessels, it deposits a very slight bright-yellow sediment, whose colour depends obviously on oxide of iron. Its specific gravity at 641° is 1:004975 ; and the specific gravity of the water col- lected at allthe different springs is identically the same. 625-4 grammes of the water were concentrated in a platinum capsule, until it began to deposit crystals. It was then thrown upon a balanced filter, and the insoluble earthy precipitate, after being strongly dried, was weighed along with the filter in a platinum crucible, in order to prevent the accession of hygros- copic moisture during the weighing. Its weight was found to be 0°324 gramme. The filtered liquid was cautiously evaporated to dryness in a balanced platinum crucible, and the residue was ignited until it began to enter into fusion, which took place before the crucible became visibly red-hot in day-light. The fused saline mass weighed 3-058 gramme. Hence 1000 parts of the water contain Soluble salts... 4 .csseecseeceverss 4890 Earthy matter .....-cecssecsoveses O518 ——— 5408 In many other experiments performed in a similar way, the uantity of solid ingredients was found to vary from 5°407 to 5-476. These differences are probably caused by the unequal quantities of carbonic acid which are expelled from the mag- nesia during desiccation. (A.) The Salts soluble in Water.—Having ascertained by pre- liminary experiments that these contained no other base than soda, and no other acids than the sulphuric, muriatic, and car- bonic, I proceeded to the analysis in the following manner: —The fused saline mass was dissolved in water; the solution was turbid, owing to the presence of some magnesia, which, collected upon a filter and ignited, weighed 0-006 gramme. The filtered liquid was saturated with acetic acid, and evaporated to dryness, with a view to determine whether the alkali retained any silica; but the dry salt redissolved completely in water without leaving any residue. Murizte of barytes being now added, precipitated a quantity of sulphate of barytes, which, washed and ignited, weighed 2°646 grammes, equivalent to 1-618 gramme of sulphate of soda. The filtered liquid was now strongly acidulated with nitric acid, and the muriatic acid was thrown down by nitrate of silver. The precipitated chloride of silver weighed 1°58 gramme. As it might be suspected that a portion of the muriatic acid had been expelled by the acetic acid, a corresponding quantity of the water (625-47 grammes) was supersaturated with nitric acid, and precipitated by nitrate of silver, 1:588 gramme chloride of silver was obtained. That 1824.] Mineral Waters of Carlsbad. 127 this quantity is slightly in excess over the former, is more pro- bably caused by the difficulty of conducting the evaporation, ignition and filtrations in the course of the experiment, without loss, than by the decomposition of any portion of muriate of soda by the acetic acid. These 1°588 gramme represent 0°6495 gramme of chloride of sodium. The deficit in the total amount must have consisted of carbonate of soda: the quantity of this salt was, therefore, 0°7845 gramme. (B.) Lhe earthy Salts insoluble in Water.--a. These being mixed with nitric acid in a platinum capsule dissolved with effervescence. In order to prevent any loss of the liquid, I am in the custom, when making a solution accompanied with effer- vescence, and also at the commencement of the evaporation, to cover the dish with a watch-glass, the convex side of which is undermost. By this means, the whole of the liquid driven up in consequence of the disengagement of the elastic fluid, is collected upon the watch-glass, and gradually drops down from its central point, while the glass itself is washed by the water which successively condenses upon it during the evaporation. In this experiment the glass happened to have been left on the capsule until the solution had attained a state of dryness. On taking it off, its under side was found to be covered with dull spots, exhibiting distinctly the edges of the drops of water which had condensed upon it during the evaporation. As the same glass had been repeatedly employed for a similar purpose, without sustaining any alteration, it was obvious that, in this instance, fluoric acid had been disengaged, and had corroded it. 6. The dry mass was moistened with nitric acid, heated, and then dissolved in water. A dark-grey coloured silica remained undissolved, which, after ignition, became white, and weighed 0:044 gramme. c. Ammonia produced in the filtered solution an exceedingly slight yellow-coloured precipitate, which, after ignition, weighed 0:004 gramme, and presented the appearance of oxide of iron. As fluoric acid, when occurring in the mineral kingdom, 1s almost always accompanied by phosphoric acid, I examined this oxide of iron before the blowpipe, and obtained from it a fused regulus of phosphuret of iron. We shall, bye and bye, find that this oxide of iron contained also silica, alumina and oxide of manganese. d. The liquid which had been treated with ammonia was mixed with oxalate of ammonia so long as any precipitation ensued. The oxalate of lime was calcined, moistened with a solution of carbonate of ammonia, and again heated until it became just visibly red. The carbonate of lime thus formed weighed 0:195 gramme. It was dissolved in nitric acid, the solution was evaporated to dryness, and the residue was dis- solved in alcohol of the specific gravity 0°793, A dark-brown 128 M. Berzelius on the {Auc. coloured substance remained, which was thoroughly washed with alcohol. Water extracted the greater portion of this sub- stance: the solution gave with oxalate of ammonia a white pre- cipitate, which was converted by calcination into carbonate of strontitan ; but its quantity was so small that I could not deter- mine its weight, nor indeed could | have satisfied myself com- pletely that it consisted of strontitan, had I not succeesed in obtaining it in larger quantity from a different source. The substance insoluble in water was oxide of manganese, but also in too inconsiderable quantity to adinit of being weighed with precision. e. The solution precipitated by oxalate of ammonia was evaporated to dryness, and the saline residue decomposed by calcination. A white earth was left, weighing 0-054 gramme. Water dissolved from it 0:005 gramme of an alkaline carbonate, which neither attacked the platinum crucible in a red heat, nor did it yield a difficultly soluble salt with muriate of platinum. It was, therefore, soda; and it appears to have formed, during the evaporation of the water, an insoluble compound with the silica and the magnesia, or lime, which was first decomposed by the nitric acid. Jf. The remaining 0-049 gramme of magnesia was dissolved in nitric acid, and the solution evaporated to dryness. By this means there was separated 0:002 gramme of silica, impregnated with a trace of manganese. There remains, therefore, for mag- nesia only 0-048 gramme. The following are the results of this analysis : MUpiAte OF ROGA AE Ur.eisue tis beanie 1-618 aro nate GrsOUas.\c.kaieatlen sce 0-790 Chloride of sodium 2). Ee 0:649 Carbonate of lime. \. s csis ssauaa cee’ 0-195 Pule CUB Mella’. sce. eke sos en 0-054 Peromde'of won sii) ee bh 0:004 BE Slee 8 ek boas Ja ate ee ne .. 0°046 3°356 The difference between 3°356 and 3-382 arises partly from unavoidable loss, and partly from the magnesia being regarded in the tabular result as completely free from carbonic acid. Although the substances which made their appearance unex- pectedly in this analysis are inconsiderable in quantity when compared with the others, it may nevertheless be worth while to examine each of them more particularly, and, if possible, to determine its amount. 1. Quantity of the Fluoric and Phosphoric Acids, and the Manner in which they exist in the Water.—In order to ascertain with still greater certainty that fluoric acid constitutes an ingre- 1824.) Mineral Waters of Carlsbad. 129 dient of the water, I pulverized a quantity of the sprudel- stone which is deposited on the evaporating pans, mixed it in a platinum crucible with concentrated sulphuric acid, and co- vered it with a bit of glass coated with etcher’s wax, and on which I had scratched a few delineations. At the end of half an hour the glass was found to be distinctly etched, and the air within the crucible had also the smell of fluoric acid. I made numerous attempts, but for a jong time fruitlessly, to separate fluoric acid immediately from the residue obtained by ' evaporating the water, and, in particular, from the precipitate which is produced by ammonia in a solution of the earthy mat- ter in nitric or muriatic acid. For this purpose I ignited the precipitate, and treated it with sulphuric acid. My failure arose from the silica in the analysis of these residues, being in a peculiarly soluble condition, forming doubtless a fluosili- cate, which was so thoroughly saturated with silica, that when the precipitate was calcined, the whole of the fluoric acid was volatilized in combination with the earth. Hence when I de- composed the precipitate, without subjecting it to a previous ignition with sulphuric acid, and made the extricated gas to pass through a solution of carbonate of soda, I obtained both the silica and the fluoric acid, the former diffused through the liquid, the latter in a state of solution, and easily precipitable by the usual treatment with a salt of lime. The quantity how- ever was too small to admit of its weight being determined with precision ; nor had I at my disposal a sufficient stock of the water for repeating the analysis on a larger scale. I had there- fore recourse to the sprudelstone, in which [ had reason to believe the carbonate and fluate of lime exist in the same rela- tive quantities as in the water; because, as shall be subse- quently proved, they are both held in solution by carbonic acid, and must therefore precipitate together in proportion as the solvent is dissipated. The sprudelstone selected by me for this examination had been formed in the establishment where the Carlsbad salts are prepared. This establishment consists of a large basia, through which the whole of the annexed water of the Sprudel is made to flow, and in which there are placed side by side a number of flattish tin vessels also filled with the water. The tin vessels are thus situated in a kind of balneum marie, and they are main- tained in this temperature, until the solutions contained in them begin to crystallize. On the outer side of these vessels the water in the basin deposits an inerustation of sprudelstone, which gradually increases in thickness. The thickness of the specimen which I analyzed was about a quarter of an inch. Its fracture was crystalline and striated, and its svecific gra- vity was 2°84: in both of these characters, therefore, it had a striking resemblance to arragonite. New Series, vou. vil. K 130 M. Berzelius on the {Aue. To determine how far the sprudelstone represents the sub- stance deposited by the water, when deprived of its carbonic acid, I mixed a quantity of the water with caustic ammonia. It instantly became turbid, and at the end of twenty-four hours there had subsided a granular and slightly yellowish coloured precipitate. The filtered liquid when concentrated deposited a white earthy matter. The first of these precipitates contained carbonate of lime and oxide of iron, but no magnesia. The second dissolved without effervescence in acids, and left a gelatinous silica. The solution contained magnesia; oxalate of ammonia produced no alteration in it, but phosphate of am- monia precipitated from it the well known double salt of mag- nesia. This experiment demonstrates that the substances held in solution by the carbonic acid are precipitated in proportion as the acid is dissipated, independently of the concentration of the liquid; but that the magnesia and silica do not make their appearance until a portion of the water has been evapo- rated. That the magnesia in this experiment was precipitated in the state of silicate, proceeded obviously from the presence : of ammonia. | The constituents of the sprudelstone represent therefore the- carbonate of lime and oxide of iron obtained in the analysis; and, consequently, by analyzing a larger quantity of that incrus- tation, it might be possible to discover the proportion in which the fluoric acid, the phosphoric acid, the oxide of iron, and the strontian, exist in the water, when compared with the carbonate of lime. a. I reduced a quantity of the above incrustation (pannsten) to an impalpable powder, and boiled it repeatedly in distilled water, in order to separate any soluble saline matter which the water might have deposited among its particles. This was afterwards thoroughly dried. 10 grammes of the powder thus purified were dissolved in dilute nitric acid. Some oxide of iron remain undissolved, but was speedily taken up on the ap- plication of heat. After the carbonic acid gas had been com- pletely expelled, the solution, which had a slight tinge of co- lonr, was filtered. A grayish powder, weighing 0:001 gramme, was by this means separated: before the blowpipe with car- bonate of soda in platinum foil it gave traces of manganese, and on charcoal it left a globule of tin. b. The filtered liquid was decomposed in a close vessel with caustic ummonia. A light yellowish coloured matter precipi- tated, which, after ignition, became brown, and weighed 0:157 gramme. It was analyzed in the following manner. Sulphuric acid.mixed with it in a platinum crucible occasioned after a few moments the disengagement of fluoric acid, and a glass prepared in the usual way, when placed over the crucible, became deeply etched. As the gas was not expelled instanta- od 1824.] Mineral Waters of Carlsbad. 131 neously and with effervescence, it is probable that the precipi tate contained no silica. When the fluate of lime had been fully decomposed, the residual saline mass was boiled in as much water as was sufficient to take up the whole of the sul- phate of lime. The solution, mixed with ammonia, gave a yellow coloured precipitate resembling oxide of iron, and weigh- ing after ignition 0:06 gramme. c. The solution, separated from the above precipate, was de- composed by oxalate of ammonia. The oxalate of lime thus formed, left, after calcination, 0°127 gramme of carbonate of lime, equivalent to 0°099 gramme of fluate of lime. d. The oxide of iron from 6, was dissolved in muriatic acid ; a white matter, weighing 0°00] gramme, remained undissolved, which, when heated with an alkali on charcoal before the blow- pipe, was converted into a globule of tin. The solution was combined almost to saturation with sal ammoniac,* and triple prussiate of potash was added, until the whole of the oxide of Iron was precipitated. The whole was then filtered, and the precipitate was washed with a solution of sal ammoniac. The filtered liquid, mixed with ammonia, gave a white flocky pre- cipitate, weighing after ignition 0'015 gramme. This was dis- solved in muriatic acid, and the solution was mixed with an excess of caustic potash. 0:006 gramme phosphate of lime precipitated. What remained dissolved in the alkali was sepa- rated by saturation with muriatic acid, and by the subsequent addition of ammonia. It fell as a white precipitate, which, however, gradually became pale amber coloured on being dried. Before the blowpipe, nitrate of cobalt developed in it a deep but rather impure blue colour, with carbonate of soda on the platinum foil it indicated traces of manganese, and with boracic acid and iron it yielded a fused button of phosphuret of iron. It consisted therefore of subphosphate of alumina, containing traces of phosphate of manganese. The liquid from which the subphosphate of alumina and phosphate of lime had been preci- pitated, being mixed with lime water, gave 0:003 gramme of phosphate of lime, whose acid (0:00135 gramme) must have been combined with oxide of iron. Subtracting this along with the weight of the other substances separated in d, from the 0-06 gramme in b, we obtain for the quantity of oxide of iron 00426 gramme. The sum of the weights of all these sub- stances corresponds almost exactly with the quantity originally submitted to analysis : an additional proof that the fluoric acid existed in the precipitate uncombined with silica. Had the contrary happened, a considerable loss would have been sus- _ ™ Salammoniac was added, because a liquid containing un excess of the triple prus- siate has the property of dissolving a considerable quantity of the blue precipitate ; but this is prevented by the presence of the dissolved salt. K ‘ 132 _ M, Berzelius on the [Ave. tained, because the fluosilicate of lime, which is precipitated by ammonia, colitains much less lime than the fluate of lime. e. Another quantity of the pulverized sprudelstone was heated to redness in a small apparatus, in which the gaseous substances disengaged were made to pass over fused muriate of lime. The total loss amounted to 2°39 per cent ; of which 1:59 consisted of water, and 0°8 of carbonic acid. By subtracting the former of these quantities 1-59 from the portion of the dis- solved sprudelstone which was not precipitated by ammonia, it is easy to obtain the quantity of carbonate of lime. Hence we find that the powder subjected to analysis contained per cent. 96:77 of carbonate of lime, 0:06 of phosphate of lime, 0°99 of fluate of lime, and 0-1 of phosphate of alumina. The oxide of tin is here neglected, because it does not proceed from the water; so also is the oxide of iron, because the sprudelstone does not always contain it in the same proportion with the other ingredients of the water, its deposition appearing to be more influenced by the accession of atmospheric air, than by the expulsion of carbonic acid. This is the reason why the sprudelstone contains a variable quantity of oxide of iron, and why it is in general marked with brown stripes. According to these data, 1000 parts of the Carlsbad water analyzed by me must_have contained PUdte OF MING soc ce ncaa a snes CUED Phosphate of lime ..........2.+. 0°00022 Subphosphate of Alumina........ 0°00032 As no silica is deposited along with the fluate of lime in the sprudelstone, it follows that the water itself contains no fluo- silicate of lime. 2. Determination of the quantity of Strontian—I employed for this purpose the liquid which had been precipitated by ammonia, in the foregoing analysis. It was evaporated to dryness, and the saline residue was treated with a slight excess of nitric acid, in order to decompose the carbonate of lime, which had been formed in consequence of the ammonia having absorbed carbonic acid during the evaporation. The nitrate of ammonia was now destroyed by ignition; and the nitrate of lime, which constituted nearly the whole of the remaining salt, was dissolved out by alcohol. A small quantity of a white matter was left behind ; being dissolved in water and precipi- tated by oxalate of ammonia, and the precipitated oxalate being calcined, it was converted into an earthy carbonate weighing 0-03 gramme. That this was carbonate of strontian, and that it did not proceed from any salt of lime which had been left undissolved by the alcohol, was demonstrated by the following circumstances : with muriatic acid it gave a salt in 1824.] Mineral Waters of Carlsbad. 133 radiated crystals, which was not deliquescent; these were somewhat soluble in alcohol, and cotton, moistened with the solution, burned with a red coloured flame; and finally, which indeed I consider the most decisive character of all, they dis- solved in a saturated solution of sulphate of lime, but at the same instant rendered it exceedingly turbid, in consequence of the formation of a difficultly soluble sulphate of strontian. Muriatic acid rendered the liquid again transparent: in proof that the precipitate did not consist of sulphate of barytes. It follows from this experiment that 1000 parts of the water con- tain 9:00096 of carbonate of strontian. 3. Quantity of the Oxides of lron and Manganese.—The ana- lysis of the sprudelstone already demonstrated that the 0-004 gramme regarded as oxide of iron in the original analysis of the water, was not that substance in a state of purity, but contained sensible quantities of silica, phosphate of alumina, phosphate of manganese, and phosphate of lime. To determine the quan- tity of oxide of iron with greater precision, 4:107 grammes of the insoluble earthy matter from the Carlsbad water were dis- solved in nitric acid, and the solution was mixed with an excess of ammonia. From the unignited precipitate sulphuric acid expelled some fluosilicic acid, which, with a view to ascertain its quantity, was made to pass through a solution of carbonate of soda. The sulphuric solution being precipitated by ammo- nia, the filtered liquid contained no lime: consequently the fluoric acid and silica had been combined with oxide of iron. Potash boiled on the precipitate, left 0°02 gramme of oxide of iron undissolved; and, from the alkaline solution, there was separated in the usual manner 0-004 gramme phosphate of alu- mina, mixed with some manganese. Lime water added to the remaining liquid, threw down a small quantity of phosphate of lime. As the oxide of iron might have been contaminated with phosphate of lime, it was dissolved in muriatic acid, and pre- cipitated by the triple prussiate of potash; but no traces of phosphate of lime could be detected in the filtered liquid. The solution from which the oxide of iron and alumina had been precipitated, was now mixed with oxalate of ammonia. IJt vielded 2°514 grammes of carbonate of lime. If we estimate the quantity of oxide of iron according to this quantity of lime, we shall find its amount in 1000 parts of the water to be 0:00248. The quantity of phosphate of alumina here found is rather greater than that obtained in the analysis of the sprudel- stone; but this is partly owing to its not having been so com- pletely freed from silica. That in these analyses the oxide of iron was always mixed with subphosphate of iron, is no proof that such a salt existed in the water : it is merely in consequence of the property which oxide of iron possesses, when precipitated from a solution con- 134 M. Berzelius on the [Aus. taining phosphoric acid, of carrying along with it a portion of that acid, of which it cannot afterwards be completely deprived even by the most powerful bases. The quantity of oxide of manganese was ascertained by dis- solving the above 2°514 grammes of carbonate of lime in nitric acid, evaporating the solution completely to dryness, and treat- ing the dry mass with alcohol. A brownish coloured substance remained undissolved ; and the oxide of manganese contained in it was thoroughly freed from any adhering nitrate of lime or nitrate of strontian, by being washed first with alcohol, and afterwards with acidulated water. It weighed after ignition 0-004 gramme. The oxide of manganese exists in the water in the state of carbonate: it never forms an ingredient in the sprudelstone, because the carbonate of manganese is almost as soluble in water as the carbonate of magnesia. According to these several analyses, the solid ingredients in | 1000 parts of the Carlsbad water are as follows : Sulphate of soda...........06: .. 258713 Carbonate at p00d, ..... cea nce ose Ck caer Chloride of sodium............- . 103852 Carbonate of lime, ...4.. 600005 .. 030860 Fluate of lime...... ena Wa fits thaccccrome 0:00320 Phosphate of lime ..........24+ 0:00022 Carbonate of strontian........... 0-00096 Carbonate of magnesia .......... 0:17834 Subphosphate of alumina ........ 0:00032 Carbonate of FON. oss siete ccelewe «0 MUGS Carbonate of manganese. .....-. . 000084 RMU x Carma oetecstad esuen sresenisie einer 5°45927 The excess of 5:45927 over 5:408, the quantity obtained by the direct evaporation of the water, is occasioned by the mag- nesia, and the metallic oxides being regarded in this estimate as combined with their full proportion of carbonic acid. I have examined in a similar manner the water from the Mill spring, the New spring, and Theresia’s spring, but found in them all, not only the same constituents, but these constituents also in exactly the same proportions, as in the water from the Sprudel ; a further confirmation that all the Carlsbad waters proceed from one common main stream, or reservoir. As it was not improbable that the Carlsbad water might con- tain a small quantity of potash, I converted a portion of the soluble salts into muriate of soda, and added as much muriate of platinum as was sufficient to form a double salt with the * Under the silica I have included a small quantity which was separated from the oxide of iron, and from the phosphate of alumina, ee eto ah ne cel ’ 1824.] Mineral Waters of Carlsbad. 135 soda The solution was then evaporated to dryness by a mo- derate heat, and the dry mass was treated with alcohol of the specific gravity 0°84. Nota trace of muriate of platinum and potash remained undissolved : the water therefore contained no potash, for that double salt is quite insoluble in alcohol. Potash must, however, on some occasions, constitute an ingredient of the water, for [ have detected the fluosilicate of that alkali in several sprudelstones. Although no circumstances gave occasion to a suspicion that lithia existed in the water, its presence was still possible. To ascertain the point, I mixed a quantity of the soluble salts with a solution of subphosphate of ammonia: the liquid neither be- came turbid, nor did it yield a precipitate by evaporation. When, in a comparative experiment, this salt was mixed with a solution of lithia, there was deposited during evaporation a crystalline powder, the greater povtion of which remained un- dissolved, on treating the dry saline mass with water. When the salt examined in this manner had not been previously fused in a red heat, it always gave with phosphate of ammonia a slight precipitate, similar to phosphate of lithia; but on examining this substance before the blowpipe, I found that with nitrate of cobalt itfused to a pale red coloured pearl, and that when it was treated on charcoal with carbonate of soda, the latter salt was absorbed, and left an earthy matter behind. Phosphate of lithia fuses with nitrate of cobalt to a blue pearl, and is absorbed by the charcoal at the same instant with the carbonate of soda. This precipitate proceeded therefore froma residue of carbonate of magnesia in the alkaline liquid. It still remains to make some observations upon the manner in which these different ingredients were combined with one another in the water. Murray first directed the attention of chemists to the fact, that the analysis of a mineral water often gives the ingredients in the state of compounds, totally different from those which existed originally in the water. This is very true; but he overlooked the difference between the results of analysis, and the actual relations of the substances. Berthol- let’s investigations respecting the action of chemical masses in conjunction with that of the relative affinities, had already, long before, given a satisfactory answer to this question. He has demonstrated that if a number of salts which do not decompose one another according to the usually admitted laws of affinity, be dissolved in water, a decomposition nevertheless ensues to a certain extent ; a portion of each acid uniting with a portion of each base, so that combinations are formed between the whole of the substances, individually, which exist in solution. Thus, if caustic soda be mixed with sulphate of potash, a certain quantity of sulphate of soda is formed, and the acid is divided between the bases in such a manner, that the uncombined por- 136 M. Berzelius on the [Aue. tions. of each correspond. If the soda were previously com- bined with muriatic acid, the decomposition would be still more extensive, because a portion of the muriatic acid would at the same time unite with the potash. Two salts were originally dis- solved in the water, but these constitute four, so long as they re- main in solution; if the water be evaporated, the two are again recovered, for the reasons which have been so ably developed by Berthollet. Should it be asked what quantity of each of these four salts exist in solution? We must allow, that so long as their amount cannot be ascertained by actual analysis, the question must re- main unanswered, These quantities depend, in the first place, upon the respective quantities of the two salts originally mixed, and, in the second, upon the relative attractive forces of the acids and bases. The former of these points may be easily ascertained, but we as yet possess no data for a precise deter- mination of the latter. Could we express the relative attractive forces of each individual substance in numbers, in the same manuer as we express its specific heat or its specific gravity, it would then become easy to perform this calculation from the re- sults of an ordinary analysis. As yet, however, not one of these relative aflinities is so thoroughly understood, that its precise amount can be compared with that of another; and, it is there- fore altogether impossible to determine with certainty, from the results of an analysis, toewhat extent the acids and bases had been combined with one another in the original solution. At present, the utmost we can accomplish, is to state the direct re- sults of an accurate analysis. Theory informs us, that the sub- stances constituting our result are different from those which actually existed in the water; but we should be wrong to asso- ciate them with one another in any other manner, because such an arrangement could have for its basis nothing better than un- certain conjecture. In the Carlsbad water, one of the bases, the soda, preponder- ates so considerably over the other, that the real constitution of the water must correspond pretty closely with the result of ana- lysis. Nevertheless, we may be certain that the water contains small quantities of sulphate and muriate of lime, as also of sul- phate and muriate of magnesia, and a correspondingly larger quantity of carbonate of soda than the analysis indicates ; although these salts are gradually decomposed, in proportion as the quantity of water is diminished during evaporation. The substances which the water contains in such extremely minute quantities, must be subject to the same law of mutual decom- position, only the action of the law will in the case of these be much less perceptible. In stating the result of my analysis, I have given the alkaline carbonates as I found them in the dry salt, obtained by eva- 1824.] Mineral Waters of Carlsbad. 137 porating the water: in the water itself, however, they all exist in the state of bicarbonates. Neither fluate nor phosphate of lime is soluble in water, but their solubility in acids led me to suppose, that, in the Carlsbad water they are held in solution by the uncombined carbonic acid. To prove this, I diffused a quantity of recently prepared and still moist fluate of lime through water, and impregnated the liquid with carbonic acid gas. The filtered liquid, on being heated to ebullition, deposited an exceedingly minute trace of fluate of lime. I now put a quantity of carbonate of soda and fluate of lime into another portion of water, and saturated the mixture with carbonic acid. The solution in this experiment became most distinctly turbid when boiled, and deposited fluate of lime. It is obvious from this, that bicarbonate of soda is the real solvent of the fluate of lime in the Carlsbad water. Phosphate of lime, both when precipitated by ammonia from its solution in acids, and by lime water from a liquid containing phosphoric acid, dissolves in water impregnated with carbonic acid with much greater facility, and to a much greater extent, than fluate of lime: and I could perceive no difference in this respect, whether the water contained soda or not. Both the phosphate and subphosphate of alumina are soluble to a slight degree in water, and are precipitated by the addition of a con- siderable quantity of any salt. No phosphate of alumina exists in the sprudelstones; it would appear that carbonic acid is its solvent while in the water. Perhaps, also, the protoxide of iron, in proportion as it becomes peroxidized, shares the acid with the alumina, and renders it insoluble; and, perhaps, the lime may act in the same manner, at the instant when it ceases to be a bicarbonate. Quantity of Carbonic Acid in the Carlsbad Water. The want of a mercurial trough, and of the other necessary apparatus, prevented me from ascertaining this point on the spot experimentally ; I hoped, however, to have attained my object by less direct means, but, on making the attempt, I encountered greater difficulties than had been at first anticipated. It ap- peared te me, that if we could determine the nature and relative amount of the gases which stand over the water in the subter- raneous reservoir, it would be easy, from the knowledge we possess respecting the solubility of gases, at given temperatures and pressures, to calculate the quantity of carbonic acid in the water which lies in contact with this atmosphere. A small opening which has been made in the vault of the reservoir, in the neighbourhood of the Sprudel, and from which gas and water are discharged alternately, enabled me to collect a suffi- cient quantity of gas for my purpose. On my return, I let up a determinate quantity of this gas into a glass tube standing over 138 M. Berzelius on the [Ave. mercury, and introduced into it a bit of hydrate of potash. It was so completely absorbed, that the minute bubble of air re- maining could not be accurately measured, and could not at the utmost have amounted to more than a thousandth part of the original volume. A quantity of gas collected in a similar way at Theresia’s spring, left one per cent. of a gas which appeared to be azote, as it was not sensibly absorbed by a solution of sul- phuret of potash. I now calculated the quantity of carbonic acid gas which the water in the reservoir should contain, on the supposition that 100 volumes of it absorb 104 volumes of the gas, at the tem- perature 1642°, making allowance at the same time for the addi- tional pressure to which it is subjected, and which may be esti- mated by the height to which the jet of the Sprudel rises above the surface of the water in the reservoir. The result was, that the disengaged carbonic acid gas, takea at the temperature 32°, should constitute three-fourths of the volume of the water. If we add to this the carbonic acid of the bicarbonates, which by weight constitutes 0°075 per cent. of the water, and at 32° would occupy 0°396 of its volume, it will follow that the water, when boiled, should emit at least 1,!, times its volume of car- bonic acid gas, measured at the temperature of 32°. But the taste alone of the water is sufficient to convince us that the quantity thus indicated is greatly in excess. By direct experi- ment, Beccher found precisely as much gas im the water as would be requisite to convert the whole of the carbonates into bicarbonates ; Klaproth found rather less than this quantity ; Reuss found rather more. I am of opinion that the quantity of gas contained in the water when it first issues from the earth, is rather greater than what would convert the carbonates into bicarbonates. This seeming anomaly is probably occasioned by a circum- stance, to which no attention has hitherto been paid in deter- minations respecting the solubility of gases in water, because it exerts but little influence at the ordinary temperatures. Water, under every temperature and pressure, possesses a determinate tension, and any gas standing over the surface of water, always contains an admixture of its vapour, which in this situa- tion acts in exactly the same manner as a permanently elastic as. When a mixture of carbonic acid gas, and of the gas (or vapour) of water stands over the surface of water, the inter- stices of the liquid must contain a portion of this gaseous mix~ ture, that is, both of the carbonic acid gas, and of the gas of water. The apparent absorption by water, therefore, of any pure gas, as for example, carbonic acid gas, in a given tempe- rature and pressure, is in fact the quantity which, in that tem- perature and pressure, is necessary to maintain the equilibrium between the carbonic acid gas and the gas of water, both 1824.] Mineral Waters of Carlsbad. 139 throughout and over the surface of the liquid. Every pure gas which is placed in contact with water becomes instantly a mixed gas in consequence of the evaporation of the liquid, and the proportion of the aqueous to the permanently elastic gas augments with the temperature. Unless this happened, it would be impossible to expel by boiling, a greater quantity of gas from water, than the difference between the augmentations of volume which the elevated temperature induces upon the gas and the water. But ebullition, we know, expels every particle of a gas from water ; and for precisely the same reason that a gas when passed through the aqueous solution of another, gradually expels the latter, and finally occupies its place, so does gas continue to be expelled from water in a state of ebullition, until the interstices of the latter become completely occupied by the newly formed vapour. But respecting the capacity of water for its own peculiar gas, we, at present, know nothing: were it known, it would be easy to ascertain by calculation the quan- tity of carbonic acid which is contained in the Carlsbad water, while confined within its subterraneous reservoir. The precipitate which always makes its appearance in the Carlsbad water, when kept for some time, consists of silicate of peroxide of iron, subphosphate of peroxide of iron, and subphosphate of alumina, mixed with a substance of organic origin, which is naturally colourless, but which by slow degrees becomes black when exposed to the action of the atmosphere. This substance appears to constitute a very common ingredient in mineral waters of this nature. I have found it, for example, in the sediment deposited by the water of the mineral spring Schiersauerling, in the neighbourhood of Koningswart; and the silica obtained in the analysis of this water is always more or less dark coloured, until the organic substance has been de- stroyed by ignition. It appears to possess a peculiar affinity for silica, and to associate itself with this earth in preference to any of the other ingredients of the water. The silica, when in combination with it, is almost black before being reduced to a state of dryness; it is then greyish coloured, but darkens again when moistened. Examination of some Sprudelstones. The sprudelstone is a radiated crystalline species of lime- stone, which exhibits no traces ofa foliated texture. Its colour is sometimes white and sometimes brown, and not unfrequently alternates in white and brown stripes. The texture varies extremely in different specimens ; sometimes it is most deci- dedly radiated, at other times it is almost compact ; and speci- mens of the latter description are not unfrequently transparent when in thin fragments. Some of the white varieties possess 140 On the Mineral Waters of Carlsbad. [Auc. an uneven fracture, and bear a close resemblance to magnesite [dolomite?] or gurhofite. Before the blowpipe, the sprudelstone swells somewhat, loses its colour, and either falls to powder of itself, or may be reduced to that state by the slightest pressure. If the experiment be made in a small glass matrass, some water is rendered visible; and the quantity of water disengaged is proportional to the radiated structure of the stone. Now this is a_ distinctive character of arragonite ;* between which and the sprudelstone there is a remarkable similarity in their fibrous texture, in their total want of any foliated structure, in their specific gravity, in the alterations which they undergo when ignited, and in their containing a certain quantity of water, and of carbonate of strontian. The compact sprudelstones contain little or no water; and acquire no tendency to disintegration by being calcined. 1. The following I ascertained to be the composition of two sprudelstones, which approached pretty closely to one another in the nature and relative proportion of their constituents. The first is the incrustation which is deposited upon the exterior sur- face of the tin vessels mentioned in p. 129. The second is a brown, fibrous, and very compact variety, which is frequently cut into ornaments. Specific gravity 2°863. Water. ¢eceee en aecee Vitae creeds treo Chonan Carbonate of lime. .... 96°47 ...... 97:00 Carbonate of strontian. 0-30 ...... 0°32 Fluate of Lime. .).,e.s:a:0194\0 HOD iene ie ae Phosphate of lime .... 0°06 ......? Phosphate of alumina.. 0°10 ..... ; 0°59 Oxide GUILE vs iea eeivien 10,2 ohne Mixide. Of. 1D. os eave emul eo Oxide of manganese.. Trace 100-00 100-00 2. A white variety, partly granular and partly delicate fibrous in fracture, on being dissolved in muriatic acid, left a semitrans- parent substance, which was converted into a white powder by desiccation. This substance was fluosilicate of potash ; for it was fusible before the blowpipe, sulphuric acid disengaged from it fluosilic acid, and the residue consisted of sulphate of potash, Ammonia threw down from the solution a yellow-coloured pre- * That this property is not possessed by every variety of fibrous limestone may be easily proved by heating fragments of sattin spar, arragonite, and sprudelstone, in a small glass matrass before the blowpipe. ‘The arragonite, and soon after the sprudelstone, fall to powder; but the sattin spar continues wholly unaltered. The richer the arrago- nite is in strontian, the speedier is its disintegration. 1824.] Col. Beaufoy’s Astronomical Observations. 141 cipitate, constituting 0:6 of the weight of the stone, and com- posed of 0:47 fluate of lime, 0:07 of the phosphates of lime and alumina, and 0-06 of oxide of iron. The ammoniacal liquid, on being concentrated, deposited an additional quantity of the fluo- silicate of potash, but the difficulty of washing it prevented me from ascertaining its weight. 3. The white compact variety resembling magnesite does not contain a trace of magnesia, agreeing; in this respect, with all the other varieties of the sprudelstone. The carbonate of strontian also, and the earthy fluates and phosphates, exist in it in the usual proportion. 4, A very peculiar variety of sprudelstone, which is formed by the combined action of oxidation and evaporation, was found to be composed of Carbonate:of lime. .), «i004 ses vee SOOO Subphosphate of peroxide ofiron .... 1:77 Peroxide Gf iron \ id. Fsiic ds caeebente 200 Carbonate of protoxide ofiron. ...... 12:13 Phosphate of alumina....... sfetin st OU POPOL. ciate Pisie\ > xa daisabpe Cadere alcifaleca 1 aD ME ALES fa iotats.t a df clble, catabte etd baie wed See 100-00* ARTICLE XIV. Astronomical Observations, 1824. By Col. Beaufoy, FRS. Bushey Heath, near Stanmore. Latitude 51° 37’ 44:3” North. Longitude West in time 1’ 20:93”. Moon eclipsed. a. 29’ 18” Mean Time at Bushey. July 10, Beginning .........++0-e2+0- 15 30 39 Mean Time at Greenwich. ARTICLE XV. ane to an erroneous Statement respecting Sir Humphry Davy’s ethod of defending the Copper Sheeting for Ships’ Bottoms. Since Sir Humphry Davy’s paper (see p. 94) was printed, the 32d number of a weekly publication, called the Mechanic’s * The sum of these quantities (correctly copied from the original) is only 90, Should the carbonate of lime be 53°2 ?—Edit. 142 Reply to an erroneous Assertion. (Aue. Magazine, has been put into my hands, which contains an atti- cle, signed Samuel Deacon, and entitled “‘ Sir Humphry Davy’s Remedy for the Decay of Copper Bottoms, not original.” . The assertion is founded on the following advertisement in “ The World ” newspaper, of April 16, 1791 :—*‘ By the King’s patent, tinned copper sheets and pipes, manufactured and sold by Charles Wyatt, Birmingham, and at 19, Abchurch-lane, Lon- don.” These sheets, amongst other advantages, “ are particu- larly recommended for sheathing of ships, as possessing all the good properties of copper, with others obvivusly superior, which the following extract from a report founded on actual experiment, by Dr. Higgins, clearly demonstrates, viz. that this coating of tin powerfully resists the action of salt water, and, by’ preventing the corrosion of the copper, operates as a preservative of the iron placed contiguous to it.” The best answer to this attack we have given already, by laying Sir Humphry Davy’s paper, from the Philosophical Transactions, before our readers, from which it is most obvious, that his views have nothing in common, except their object, with those of the patentee aforesaid. As far as the extract given by his advocate, Mr. Deacon, enables me to judge, it seems that the superiority claimed by Mr. Wyatt consists merely in coating the surface of the copper sheets with some substance less subject to corrosion by sea water than that metal, and his idea was probably borrowed from the common practice of tinning culinary copper vessels,—a practice known to, and adopted by, the Romans.* As Mr. Deacon gives no particulars of the mode of applying or preparing these tinned plates, it is fair to infer that there was nothing peculiar to them in either respect, and all the claim that he can possibly make out to originality is in the application of an old fact to a new purpose, But it is not on the substitution of tinned copper for plain copper, that Sir Humphry Davy’s pretensions to originality rest : it is in the principle on which that substitution, or rather an equivalent and, as we shall presently see, a superior process is recommended, that his claims are founded. For the explana- tion of that principle, I refer the reader to Sir Humphry Davy’s paper; but I will ask, did Mr. Wyatt know, that even though nine-tenths of the tin be worn away from a copper saucepan, and the copper exposed, the vessel may still be used with safety ? Could he have explained the cause, if he knew the fact ? When he prepared his sheets, did he carefully tin the whole surface, or was he aware that if the preservative metal were applied toa comparative speck of it only, it would be equally effectual? Or, lastly, had he the remotest idea that, so applied, it would act as * Stannum illitum zneis vasis saporem gratiorem facit, et compescit «ruginis virus, &c,—(Plin. Hist. Nat. lib. 34, c. 17.) 1824.] Reply to an erroneous Assertion 143 a preservative at all? If he did know all this, he knew much more than one of the ablest chemists of the day; for Dr. Watson, in the seventh edition of his Essays, published in 1800, insists very strongly on the danger of tinned copper vessels, in case of abrasion of the tin; and so apprehensive was he of the consequences of the minutest portion of copper being uncovered, that he says that “a new copper vessel, or a copper vessel newly tinned, is more dangerous than after it has been used; because its pores, which the eye cannot distinguish, get filled up with the sub- stances which are boiled in it, and all the sharp edges of the prominent parts become blunted, and are thereby rendered less liable to be abraded.” Dr. Watson, therefore, was so far from being aware of the principle on which Sir Humphry Davy’s invention is founded, that he obviously was not even aware of the fact alluded to, and the Birmingham patentee was probably not much better informed than the Bishop of Llandaff. At the date of Mr. Wyatt’s patent, and for many years after, all the world was ignorant of the principle of action of the defending meta!; nor was it developed till the instrument of Volta, in the hands of Davy, furnished the clue; and its present important application is, in fact, an extension of the same train of reason- ing that led to his preceding discoveries in electro-chemical science. . It isin the principle, therefore, I repeat, that. the merit and ori- ginality of SirH. Davy’s method is founded, and the importance of the principle is confirmed by a circumstance which would have rendered a mere mechanical covering, like Mr. Wyatt’s, useless and abortive. The defended copper is more liable to become fowl from the adhesion of barnacles, weeds, &c. than the unde- fended. Had Mr. Wyatt’s tinned sheeting been adopted, it would have been subject to the same pest, nor is it probable that in the then state of chemical science, he could have suggested a remedy for the evil. With the light thrown on the subject by Davy, the antidote is obvious. Barnacles, &c. do not adhere to the undefended copper, because the oxide on its surface poisons them, but the clean metallic surface of the defended copper does them no harm. All that is necessary, therefore, is to weaken the defensive action, by diminishing the extent of defending surface, to such a point as to allow a slight oxidation of the copper, sufticient to repel the animalcule, but not sufficient to occasion a serious waste of the metal. J ihr a 144 Analyses of Books. [Aue. ArticLte XVI, ANALYSES OF Books. Philosophical Transactions of the Royal Society of London, for 1824. Part I. Or the papers contained in this part of the Philosophical Transactions, two are given entire in the present number; we purpose to reprint two others, of similar value, in the ensuing numbers of the Annals; of three others copious reports have already been presented to the reader: whilst the remainder, being on subjects of Astronomy and Mathematics, cannot usefully be epitomized. We shall, therefore, confine our extracts in this place to the titles of these papers. I. The Croonian Lecture.—On the Internal Structure of the Human Brain, when examined in the Microscope, as compared with that of Feshes, Insects, and Worms. By Sir Everard Home, Bart. VPRS. (See Annals, N.S. vii. p. 65.) II. Some Observations on the Migration of Birds. By the late Edward Jenner, MD. FRS. (See ibid. p. 66.) Ill. On the Nature of the Acid and Saline Matters usually existing in the Stomachs of Animals. By William Prout, MD. FRS. (See present number, p. 117.) IV. On the North Polar Distances of the principal Fixed Stars. By John Brinkley, DD. FRS. &c. Audrew’s Professor of Astronomy in the University of Dublin. V. On the Figure requisite to maintain the Equilibrium of a Homogeneous Fluid Mass that revolves upon an Axis. By James Ivory, AM. FRS. VI. On the Corrosion of Copper Sheeting by Sea Water, and on Methods of preventing this Ljfect ; and on their Application to Ships of War and other Ships. By Sir Humphry Davy, Bart. Pres. RS. (See present number, p. 94.) VII. A finite and exact Expression for the Refraction of an Atmosphere nearly resembling that of the Earth. By Thomas Young, MD. For. Sec. RS. VU. The Bakertan Lecture.x—On certain Motions produced in fluid Conductors when transmitting the Electric Current. By J. F.W. Herschel, Esq. FRS. 6a. wen oe: a. oish Oe donee ast, 4 oe VE EEN ex 50h 2d atin tis ® ded) OS clans te ca, le Saha e aan) eee The quantity of oxide of copper alone indicates decidedly to which of these two calculations our salt ought to be referred. In order, however, that I might not depend entirely upon pre- ceding experiments, according to which the composition of this salt has been calculated in the tables (although there was no reason for doubting their accuracy), I made a new experiment with a view to determine with certainty the quantity of oxide of copper; and I employed for this purpose crystals of a salt which had never been dried otherwise then by long keeping : 100 parts of this salt were dissolved in dilute sulphuric acid ; and after evaporation to dryness, the excess of sulphuric acid was expelled, by ignition over the flame of a spint lamp. The sulphate of copper, which was in the state of small white crys- talline grains, weighed 79 parts ; and on being again exposed to a moderate red heat, it sustained no additional loss of weight. 79 parts of sulphate of copper are equivalent to 39°29 parts of oxide of copper; if we now abstract the water of decrepitation, which the crystals of this salt sometimes contain in considerable quantity, my result will be found to coincide still more closely with calculation. The formula and compo- sition which I have given in my Chemical Tables for the acetas cupricus c. aqua, are therefore accurate. 2. The Subacetates obtained by treating Verdigris with Water. Verdigris, when put into water, swells up, and is converted into a doughy mass, composed of minute crystalline scales. The filtered liquid, when’ m a state of- concentration, has an 1824.] Acetic Acid with Peroxide of Copper. 193 intense dark blue colour; but it is difficult to wash the inso- luble portion thoroughly by this means, because the crystals speedily close up the pores of the filter. If verdigris be washed with water for a number of times in succession, the filtered liquid continues to retain its original intensity of colour; a proof, that it extracts to the last a compound which requires for solution a large quantity of water. This circumstance, together with the blue colour of the liquid, demonstrates suf- ficiently, that the solution does not contain merely the neutral salt, as has been stated by Phillips. When the blue liquid is heated almost to ebullition, it lets fall a flocky liver-brown coloured substance ; after this it becomes green, and holds in solution the neutral salt. If, on the contrary, the blue liquid be evaporated in so moderate a heat, that it shall never appear brown, which is easily done, so long as it continues dilute, it deposits on the sides of the vessel, just at the edge of the solution, a confused blue coloured saline mass, of a peculiar. dendritic appearance: the same salt accumulates on the edges of the filter, and shoots up into moss-like excrescences. By allowing this gradual evaporation to proceed to a state of dry- ness, the blue saline mass is also obtained, but mixed with crys- tals of the green neutral salt. After the washing of the insoluble portion of the verdigris has been protracted for a considerable length of time, the liquid at last passes through colourless; and there remains upon the filter a blue coloured powder, which has usually a blackish tint, where it lies immediately in contact with the paper. Hence it follows that cold water converts verdigris into three distinct salts, namely, into the neutral acetate of copper, and into two sub-salts, one of which is soluble and the other insoluble in water. Verdigris when diffused through a small quantity of hot water does not become black. The solution has a dark blue colour, and contains a large quantity of the soluble sub- salt; on cooling, nearly the whole of this compound separates in the state of a blue coloured mass, which does not exhibit the slightest indications of crystallization. If the verdigris be boiled with a large quantity of water, it is rendered brown; and in proportion as the quantity of water employed for this pur- pose is augmented, the lower is the temperature necessary to produce this alteration, so that when the water is in great excess, it may be completely effected in a temperature so low as 104° (Fah.) In this experiment there is formed a brown sub- salt with a great excess of base, and the solution, provided it be very dilute, contains even a quantity of uncombined acetic acid, mixed with the neutral salt. The Sub-salt soluble in Water.—This salt may be prepared in the following manner :—a. A solution of verdigris in distilled water is to be concentrated in a very gentle heat, until the New Series, vow. viii. o 194 M. Berzelius on the Combinations of (Sept. greater portion of its saline contents is deposited. The liquid, together with this deposit, is now to be heated, until the whole of the latter, which may consist of a mixture of the neutral and sub-acetates, is redissolved, and the concentrated solution thus obtained is to be mixed with alcohol. After about an hour, there is found deposited a bulky gelatinous looking mass, com- posed of an aggregation of minute ‘crystals. These are to be collected upon a linen cloth, and thoroughly washed with alco- hol. When dry, they have rather a pale blue colour.—b. A boiling-hot aqueous solution of the neutral acetate of copper is to be mixed with ammonia, so long as the precipitate thereby produced continues to be redissolved. The liquid is then to be filtered. On cooling, it deposits an. regular uncrystallized mass, and alcohol separates from the cold supernatant liquid a considerable quantity of the same compound, in the form of excessively minute crystalline scales. The salts thus obtained must be washed with alcohol, in order to free them from any adhering portions of the neutral salt; after this treatment, caustic potash disengages from them no traces of ammonia. If, during the preparation of this salt, the solutions are em- ployed in a state of too great dilution, there separates, both by evaporation, and by the addition of alcohol to the solution of the neutral salt, a quantity of the insoluble sub-salt, which, when obtained in this manner, cannot be distinguished by its external appearance, from the soluble sub-sait precipitated by alcohol. The salt, prepared by either of these processes, when ex~- posed for some hours in the state of a fine powder to a tempe- rature of 140°, lost in different experiments 9:5, 10, and 10:3 per cent. of its weight. The residue, which had acquired by this treatment a greenish tint, was boiled for an hour. in water along with hydrate of barytes: the mixture was then filtered, and the oxide of copper washed. The filtered hquid was freed from its excess of barytes by a current of carbonic acid gas, after which it was evaporated to dryness with a moderate heat. The acetate of barytes, redissolved in water and filtered’from the insoluble carbonate, gave with sulphuric acid 84 of sulphate of barytes, representing 36°8 of acetic acid. The oxide of copper was dissolved from the filter by an excess of muriatic acid. The solution, after filtration, was heated nearly to ebul- lition, and a slip of polished iron plate was introduced into it, with a view to precipitate the copper. The metallic copper, after having been thoroughly washed and dried, was transferred into a small apparatus prepared for this experiment, in which it was ignited, first in a current. of atmospheric air, in order to burn away the charcoal deposited by the iron, and afterwards in a current of hydrogen gas, in order to reduce the oxide of cop- per. In this manner, I obtained 34°35 of metallic copper, ee we a ee ae Se se en 1824.] Acetic Acid with Peroxide of Copper. 195 equivalent to 43°19 of oxide of copper. (In other experiments I obtained from 86-6 to 86:8 of sulphate of copper, which gives a similar result.) The oxide of copper and the acetic acid amount together to 79:99, and 10 of water had been expelled in the temperature of 140°; consequently 10-01 of water still remained in combination, that is, the salt lost one half of its water of crystallization, by the application of heat. 43°19 of oxide of copper contain 8°/1 of oxygen, and 36°8 of acetic acid contain 17:3 of oxygen, that is, twice the quantity of the oxide of cop- per, for 8°71 x 2 = 17-42. The oxygen in the whole quantity of water amounts to 17°78, in one half of the water, therefore, it amounts to 8°89; a slight excess over the oxygen of the oxide, which is occasioned undoubtedly by the presence of some hygroscopic moisture. The salt, after having been ex- posed to a temperature of 140°, is constituted therefore of 3 atoms of oxide of copper, 4 atoms of acetic acid, and 6 atoms of water. The salt, before exposure to heat, contains 12 atoms of water, and is composed of By experiment. By calculation. Atoms. Mult. ofoxy. Peroxide of copper .. 43:19 .... 43°24 .... 3 2... 1 PUG ACG, oa ere > GOBO. vege GLE ie osie Eiyvee 2 eos comes: mt ado pre SOU ME crorahstaig teen Paced Reeeiia ge ie all The insoluble Sub-salt.—-This compound may be prepared by allowing verdigris to swell up in water, and afterwards filtering it through coarse linen, which retains any impurities which may have existed in the verdigris, but allows the minute scaly crystals to pass freely between its threads. The crystalline scales are now to be separated by pouring the whole of the filtered portion upon fine cambric. They should be pressed closely together and washed a few times with water; after this, they should be transferred upon a paper filter, and thoroughly washed with alcohol. When obtained in this manner, they constitute a mass of small light blue shining crystalline scales, having a deeper and purer blue colour, than the preceding solu- ble sub-salt. Dried in a temp. of 212°, they lose only an incon- siderable quantity of hygroscopic water, and sustain no altera- tion in their appearance. When put into water, they swell up, as happens with verdigris, into a pasty mass. Calcined in a balanced porcelain crucible, this salt left 64°25 per cent. of its weight of peroxide of copper. This calcination can be advantageously accomplished only when the sub-salt is in the state of hard lumps, and when the crucible is covered pretty closely with its lid until the whole of the acid be expelled: unless these precautions be attended to, the combus- tion of the mass is accompanied with slight detonations, and a portion of the oxide of copper is carried off mechanically by the disengaged gases. In another experiment, I obtained 02 196 M. Berzelius on the Combinations of (Serr. 129-4 parts of sulphate of copper by saturating 100 parts of the salt with sulphuric acid, expelling the excess of acid by evapo- ration, and exposing the dry mass to a low red heat. This corresponds with 64:36 peroxide of copper. A different quan- tity of the same salt, decomposed by hydrate of barytes in the manner described in the analysis of the sub-salt, yielded 63 per cent. of sulphate of barytes, equivalent to 27-6 per cent of acetic acid. For the water, therefore, there remains 8-04 per cent. The oxygen of the oxide of copper is 12°98, of the acetic acid 12°97, and of the water 7°15; consequently, the acid and base contain equal quantities of oxygen, and the water contains half as much as the oxide. The composition of this salt is therefore By experiment. By calculation. Atoms. Mult. of oxy. Peroxide of- copper, 0. «64° BB» ss sine G4:82,» wn msy' id gee Hed iO O1NC (ACI 6 aice ann bi ainace ¥y ol: plein a. aL DEAS le bbe ada AN TACT es epee ee ana ame | eh kA cuditiniis ils tsa wel al clea oie geen If the salt contained 4 atoms of water, in which case it might be regarded as composed of 1 atom of neutral anhydrous acetate of copper, and 2 atoms of hydrate of peroxide of cop- per, the quantity of oxide would amount only to 63°27 percent.; but in the analysis both of this specimen of the salt, and of others prepared on different occasions, I have invariably ob- tained more than 64 per cent. of peroxide of copper. At the commencement of my examination of this salt, I felt disposed to suspect that the differences‘of colour which it exhibits might be occasioned by a compound of this nature with hydrated per- oxide of copper, which would probably possess a blue colour, and that, on the contrary, the green variety might be nothing else than an ordinary sub-salt. But experiment does not appear to corroborate this conjecture. If a boiling hot solution of acetate of copper be mixed with caustic ammonia so long as the precipitate continues to be redissolved, and if after this treatment it be kept for some hours in a temperature of about 140°, there is deposited a blue crystalline salt, agreeing in composition with the preceding. If the liquid be now allowed to cool, it deposits the neutral acetate in crystals, and the soluble sub-salt in a cohering spongy uncrystallized mass. if a solution of the neutral salt be precipitated by caustic ammonia, with the precaution that the whole of the acetic acid shall not be combined with the alkall, we obtain a green coloured gelatinous substance, which after having been washed becomes light blue coloured, but is never in the slightest degree crystallized. Towards the conclusion of the washing, alcohol must be employed in place of water, otherwise it will become black. This compound does not swell up when put into water, a property which seems to belong peculiarly to the crystalline 1824.] Acelic Acid with Peroxide of Copper. 197 scales. On being examined, it was found to possess exactly the same composition with the salt last analyzed. This sub-salt I have besides obtained by still different pro- cesses. For example, when hydrated peroxide of copper is macerated for some hours ina solution of the neutral acetate, it is converted into a light-grey coloured, heavy, pulverulent powder, which, when taken from tke liquid and washed, becomes green. If a concentrated boiling hot solution of acetate of copper be mixed with caustic ammonia, with the precaution that no excess of the alkali be added, we obtain a heavy granular precipitate, of a dull greyish green colour, and which is uncommonly easily washed. Under a microscope this compound appears to consist of transparent, cubical crystals, having their corners rounded off. When heated, they decrepi- tate. All these dissimilar varieties, when treated with sulphuric acid, yielded 129°4 parts of sulphate of copper for every 100 parts of the dried salt: they all appeared therefore to consti- tute the same sub-acetate. This combination, therefore, is the most easily formed, and possesses the best defined composition of all the sub-acetates of copper. The acetic acid is combined ia it with thrice as much oxide as inthe neutral salt. Since in this salt, the oxygen of the water of crystallization is only one half of what is contained by the peroxide of copper, I attempted, by digesting sub-sulphate of copper ina solution of acetate of soda, to produce an analo- gous compound, in which the oxygen of the water and of the oxide would be equal; but no mutual decomposition took place between the two salts. In the three salts now analyzed we have found, therefore, that the oxide of copper combines with the acetic acid in the multi- ples in which bases usually combine with acids containing 3 atoms of oxygen, namely, 1, 1-5, 3, What is the constitution of verdigris ? 3. Verdigris. Verdigris occurs in commerce under very different appear- ances ; sometimes it is green, sometimes it is bluish green, and very frequently it has a beautiful blue colour: Sometimes it dissolves in acetic acid, without leaving any residue of mecha- nically intermixed impurities, while, on other occasions, it leaves undissolved a considerable quantity of protoxide of cop- per. Ingeneral, however, we may refer it to one or other of two principal varieties, the green and the blue. These colours are most accurately distinguished, when the compounds are in the state of powder. What difference in the processes of ma- nufacture occasion this dissimilarity in appearance, | have been unable to discover ; because I procured the specimens for my experiments from merchants who were ignorant of the places 198 M. Berzelius on the Combinations of. —- [Serv. from which their stock of verdigris had been obtained. I satis- fied myself, therefore, with selecting for this examination the greenest and the purest blue coloured specimens in my pos- session. 1. The Green Variety.—Dried in the state of powder, in the open air, this variety left after calcination from 44 to 44-6 per cent. of peroxide of copper. When previously dried in a tem- perature of 140°, it left from 49 to 50 per cent. 100 parts of a quantity dried in this manner, on being analyzed by hydrate of barytes according to the process already detailed, yielded 83°33 parts of sulphate of barytes, and 49°86 narts of peroxide of cop- per. This variety of verdigris, therefore, when dried in a tem- perature of 140°, was composed of Peroxide of copper ...... 49°86 containing oxygen 10:07 PACE HIG) BUGIS caiorre Bp .. 36°66 17:23 Water, including loss .... 13°48 11-88 The quantity here stated as water, comprehends also certain foreign admixtures, which were in too minute a state of division to admit of being separated without loss. The result demon- strates pretty decisively, that the mass was a mechanical mix- ture, in which the sub-salt soluble in water formed a_ principal constituent. The property which the soluble sub-salt possesses of giving off half its quantity of water when dried in a tempera- ture of 140°, is an additional proof that it constitutes a chief ingredient in this variety of verdigris, because the latter itself loses about 10 p. c. of water when exposed to a similar degree of heat. 2. The Blue Variety.--1 obtained a remarkably pure speci- men of this variety, which, when examined under a magnifying glass, was found to consist of an aggregation of very minute, shining, crystalline scales. Its powder had an uncommonly beautiful and pure pale blue colour, resembling that of the blue carbonate of copper when pulverized. Dried in a temperature of 68°, and analyzed by hydrate of barytes and by the precipi- tation of metallic copper, in the manner already described, 100 parts of it yielded Atoms, Peroxide of copper.. 43°34 containing oxygen 8°74 ...... l Acetic, REI sc se nin ops 27°45 1290 Re Seer 1 Witer. v. sss temo ee Pe helt bt 6 This result coincides with that of Phillips, and demonstrates that the oxygen of the acetic acid is |+ times that of the base, and that the oxygen of the water is thrice that of the base. The blue species of verdigris, therefore, constitutes an indis- putable exception to the empirical law. So long as we continue unacquainted with any other varieties of this compound, it will Ae eae ae ee 1324.] Acetic Acid with Peroxide of Copper. 199 be difficult to decide with perfect certainty, whether its consti- tution forms an actual exception to the law, or whether its component parts may not be considered to be in conformity with the law, but merely associated in more complicated com- binations. I shall here, without however professing to attach to it any particular importance, explain the view which I have endea- voured to take of the constitution of this compound. I dried 100 parts of the pulverized blue verdigris in a steam bath in the temperature of 212°, until it ceased to sustain any farther loss of weight. The residue weighed 76°55 parts. The powder had by this treatment diminished considerably in volume, and had acquired a fine green colour. These 76°35 parts are com- posed according to the preceding analysis of Peroxide of copper ...... 43°34 containing oxygen 8°74 Mee MC ACI. “fete rers va an 2040 12:90 BNET shed ci seins plaka vies (1 OF 70 5°12 The oxygen of the water possesses no determinate relation to that of the oxide of copper: but if we suppose that the blue variety of verdigris is resolved, in consequence of the separa- tion of water, into neutral acetate, and insoluble sub-acetate, (in which the acid saturates thrice as much base as in the neu- tral salt,) both retaining their usual quantity of water of crystal- lization, the mixture would consist of an atom of each, namely, Cu A? + 2 Ag Cus A? + 3 Aq. That is, the oxide of copper existing in it would contain 8 atoms of oxygen, and the water 5. Now 8: 6:: 874: 5-46. That the experimental determination of the water falls some- what short of the theoretic, is occasioned probably by all the verdigris of commerce containing a slight admixture of the inso- luble sub-acetate. The calculation is of course made on the supposition that the verdigris is in a state of complete purity. It is therefore pretty certain, that a temperature of 212° alone, without requiring the intervention of water, decomposes verdi- eris into an atom of neutral, and an atom of sub-acetate. We have also seen that water, both when cold and hot, is capable of accomplishing the same alteration. It cannot be doubted then, that in this compound the constituents are retained in union by very feeble affinities. 1 at first conjectured, that, in the preparation of verdigris, the accession of oxygen is so limited, that an acetate of pro- toxide of copper only (Cu A) is in the first instance formed, and that this compound, by absorbing oxygen from the atmo- sphere, is gradually converted into a salt of peroxide, through a 200 M. Berzelius on the Combinations of [Sepr. process similar to that by which epigenous crystals are pro- duced in the mineral kingdom: it was easy to conceive that since the salt of protoxide retains its solid form during the whole period of its transformation, the constituents of the com- pound into which it is finally changed might be held together mechanically in very different proportions from those in which they would naturally combine, when enjoying a state of com- plete freedom. 1 had previously ascertained that when verdi- gris is distilled in close vessels with a very slowly augmented heat, there is obtained at a certain period of the process a white sublimate, which sometimes fills the cavity of the retort with a light aggregation of crystals, resembling wool. This sublimate is anhydrous acetate of protoxide of copper (Cu A). I attempted, by exposing it to a moist atmosphere, to convert it into a compound containing the acid and base united in the same manner as in verdigris, but it underwent no alteration. When kept in water, it is decomposed, hydrate of protoxide of copper separating in the state of a yellow powder, and neutral acetate of peroxide of copper passing into solution, in propor- tion as the salt of protoxide absorbs a maximum of oxygen from the atmosphere. 1 stratified thin plates of polished copper with pulverized neutral acetate of peroxide of copper made into a paste with water, and exposed the whole for two months to an atmosphere which was constantly changing, but taking care, during the whole of that period, to preserve the mass in a state of saturation with moisture. At the conclusion of the experi- ment, the metallic plates were found covered with an incrusta- tion of small, silky, shining, blue-coloured crystals of the blue variety of verdigris ; and these, being separated and dried in the open air, yielded precisely the same analytical results as the verdigris which occurs in commerce. This result totally refutes the idea of an epigenous formation of verdigris, and demon- strates that copper, with the assistance of acid and water, acquires the property of combining with the previously formed neutral salt. f It appears to me not unlikely that the opinion of Proust, who regarded verdigris as a compound of the neutral salt with hydrated-peroxide of copper and water of crystallization, may, perhaps, prove the most accurate. I have already endeavoured to show that the blue carbonate of copper (azure copper ore) is composed of an atom of hydrate of peroxide of copper, and two atoms of neutral carbonate of copper; and also that the artifi- cial carbonate of zinc and magnesia alba are both analogous compounds of hydrate and carbonate.* More recently, an English philosopher + has discovered a blue crystallized mineral * Afh, i Fysik, &e. vi. 12, et seq. + Brooke, Annals of Philosophy, Aug. 1822, p. 118. —— ee a ee 1824.] Acetic Acid with Peroxide of Copper. 201 composed of an atom of sulphate of lead and an atom of hydrated peroxide of copper (C Aq® + Pb 8). Is it not equally possible that hydrated peroxide of copper may combine, under favourable circumstances, with acetate of copper! It may be objected that the quantity of water is greater than is required to form a hydrate ; but such also is the constitution of the combinations of oxide of zinc and of magnesia already alluded to, and it is surely not assuming too much to admit an excess of water which is only double the water of crystallization contained by the two compounds when separate. On this supposition, the for- mula for the constitution of verdigris would be Gu A? + Cu Aq", instead of Cu A + 6 Aq.* We may add, that if the constitu- tion of verdigris were correctly represented by the latter simple formula, it would be difficult to expect so remarkable a mobility among its constituents, that the weakest chemical force dis- unites then, and causes them to combine in different proportions 4, Black Sub-acetate of Copper. When the soluble sub-salt is heated in a dilute solution, it deposits a flocky liver-brown coloured substance, which, when received upon a filter, washed, and dried, appears black, and soils strongly every thing with which it comes incontact. This substance passes readily through the filter, and renders the water turbid whenever we begin to wash it. If it be washed so long as the water continues to dissolve out any copper, and if the filtered liquid be evaporated to dryness, there is left upon the glass a thin, transparent, colourless film, resembling a coat- ing of varnish. This proceeds from the brown salt, which had been dissolved by the water. If it be prepared by boiling verdigris or the insoluble subsalt in water, the filtered liquid is more easily obtained transparent ; but, in this case, a portion of the insoluble green salt always escapes decomposition, and remains, therefore, intermixed with the precipitate. 100 parts of this black subsalt dried in a temperature of 150°, on being analyzed by hydrate of barytes, and by precipitating the copper with a plate of iron, yielded from 5°6 to 5:7 parts of sulphate of barytes, and from 91-6 to 92:5 parts of peroxide of copper. In another experiment, in which the salt was decom- posed with sulphuric acid, I obtained 183-95 parts of sulphate of copper = 91°46 peroxide of copper. The mean of these analy- ses indicates 92 per cent. of peroxide of copper, whose oxygen * I think it probable that compounds may hereafter be formed containing a still larger proportion of hydrated oxide of copper 5 for in the verdigris which I prepared, I observed portions of an intense and pure dark blue colour, whose quantity, however, was too inconsiderable for purposes of an analytical examination. 202 Combinations of Acetic Acid with Peroxide of Copper. (SEPT. is 18:55. 5°6 parts of sulphate of barytes are equivalent to 2:45 parts of acetic acid, whose oxygen is 1151; but 1-151 x 16= 18-416. For the water there remains 5°55, whose oxygen is 4-934: this again is only a very little more than four times the oxygen of the acetic acid, or one-fourth of that of the peroxide of copper. This salt is therefore composed cf By experiment. By calculation. Atoms. Peroxide of copper sin: 92-00: «008. 92i8Qiea8 cain 28 Aceticiacid:, «,..iniay 24d isiamad) seth twwheamanad Wabkeniciiimolasist cities.) (D°9D3 ppacoms ob e Oebou ws vesetele The following is a summary of the results to which | have been conducted by the experiments detailed in this memoir, 1. Acetic acid is capable of combining with peroxide of cop- per in the following proportions : 1. Neutral acetate of peroxide of copper = Cu A? +2 Aq 2, wlalue verdigris...5'y a »,si\s'p.on0 eee eee CuA + 6 Ag Cu? At + 12 Aq 4. Insoluble subsalt .....0....e0e005 = Cu? A? + 3 Aq | 5. Black, ox DLOWMSMDSIE «sss. cole Cut A + 123 Aq If the quantity of base in the neutral salt be regarded as unity, its quantity in the others, when compared with the same quantity of acid, will be found to constitute multiples of the unit by the numbers 114, 2, 3, and 24 (482). In the first salt, the base is combined with twice as much acid as in the second ; and in the third, with twice as much as in the fourth. 2. Of all these salts the second has the simplest composition, and consists, if the calculation be made directly from the weight of its component parts, of the simplest number of atoms ; but it possesses a property which is directly contradictory of this sup- posed simplicity of constitution, for its ingredients are retained in union by weaker affinities than in any of the other combina- tions of acetic acid and peroxide of copper, and have a greater tendency to separate, and to recombine in other proportions. A temperature of 140° decomposes it, with the loss of a portion of its chemically combined wate1, into an atom of the first and an atom of the fourth salt. A sufficient quantity of cold water decomposes it into an atom of the first, an atom of the third, and two atoms of the fourth salt; and asufficient quantity of boiling water decomposes it into a large number of atoms of the first salt, and a very few of the fifth. From all these circumstances, together with this, that in the salt the oxygen of the acid is not a multiple by a whole number, but by 1+ of the oxygen of BSoluble subsalt sea, Ne. 1824.) Dr. Thomson’s Reply to M. Vauquelin. 2038 the base, it appears probable that the blue variety of verdigris does not possess so simple a constitution as is indicated by the foregoing formula, but that it may be a compound of the first salt with hydrated peroxide of copper and water of crystalliza- tion; on these grounds, its composition would, perhaps, be more accurately represented by the formula Cu A? + Cu Aq? + 10 Aq, in the last term of which, the water of crystallization is distinguished from the portion which acts as an acid when in combination with the peroxide of copper. ArtTicLeE VII. Reply to M. Vauquelin’s Remark on a supposed Contradiction in Dr. Thomson’s System of Chemistry. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Glasgow, Aug. 10, 1824. On my return home yesterday from Berwickshire, I found the number of your journal for the present month lying on my table. My attention was naturally attracted to the notice in p. 147 translated from the Ann. de Chim. and entitled “ Note ona Contradiction in Thomson’s System of Chemistry respecting Phosphuretted Hydrogen Gas. By M. Vauquelin.” M. V. ob- serves, that I state in the first place that phosphuretted hydrogen contains its own volume of hydrogen united to a volume of phosphorus vapour; that when it is exposed to the direct rays of the sun, a quantity of phosphorus is deposited, and bihydro- guret of phosphorus obtained ; and that when sulphur is heated in bihydroguret of phosphorus, the bulk is doubled, and two volumes of sulphuretted hydrogen obtained. M. Vauquelin then goes on to show, that these two statements are inconsistent with each other, and that when sulphur is heated in phosphuretted hydrogen gas, only a very slight increase of bulk takes place. tle mentions also that the deposition of phosphorus takes place without any exposure to the sun’s rays, and more rapidly during the night and ina dark place than during the day. Had M. Vauquelia paid attention to the account whioh I have given of bihydroguret of phosphorus in the passage of my System of Chemistry which he quotes, he would have seen the cause of the apparent contradiction which he notices. It is owing to my having supposed that phosphuretted hydrogen gas, when altered by keeping, is converted into the gas which Sir H. Davy obtained by heating hydratea phosphorous acid, and which he described in Phil. Trans. for 18]2, p. 408. ‘To this account I referred in my System, thus pointing out the source whence { 204 Dr. Thomson’s Reply to M, Vauquelin. (Serr. derived my knowledge of the properties of bihydroguret of phos- phorus. Davy found that the bulk of this gas was doubled when potassium was heated in it, or when sulphur was sublimed in it. He states that three volumes of it require for complete combus- tion more than five volumes of oxygen gas; and that it is a compound of one part by weight of hydrogen and five parts of phosphorus. Now this (when the requisite corrections are made) is the same as if he had said that it is a compound of two atoms hydrogen and one atom phosphorus. In consequence of these statements of Davy, I thought myself entitled to conclude that the gas which he described was a compound of two atoms hydrogen and one atom phosphorus, and [ called it in conse- quence bihydroguret of phosphorus. I had myself determined by experiment that when phosphu- retted hydrogen gas is left for some time over water or mercury, it deposits phosphorus without any perceptible alteration in its bulk, loses the property of burning spontaneously when mixed with atmospheric air, and yet still continues a compound of phosphorus and hydrogen. Hence I inferred that it had become the identical gas described by Davy. But I made no experi- ments on the effect produced on it by potassium and sulphur, relying on the accuracy of Davy’s statements. But I still considered that it would be necessary to determine the point by direct experiments ; and more than two years have elapsed since I setabout examining the subject. I left a quan- tity of pure phosphuretted hydrogen in a graduated glass jar over mercury for six months; namely, from January to August. The mercurial trough was placed nearly in the middle of my laboratory, which is a large room, and so that the sun never shone on the gas. Another jar filled with the same gas was placed over mercury im the dark, and left for the same length of time. But it must have been accidentally overturned, and again replaced by some person ; for when i examined the gas, I found it to be common air. The gas standing in the middle of the laboratory had not sensibly altered its bulk; but a portion of phosphorus had been deposited on the inside of the jar. It did not burn when mixed with common air or oxygen gas; but still had the peculiar smell which characterizes phosphuretted hydrogen gas. Its bulk was not in the least altered by sublim- ing sulphur in it, so that in this respect (as Vauquelin states) it resembles phosphuretted hydrogen, and differs from Davy’s gas. One volume of it required tor complete combustion 14 volume of oxygen gas. When a volume of itis mixed with 0°75 volume of oxygen, and an electric spark is passed through the mixture, detonation takes place, and the oxygen disappears ; but the resi- dual gas is within one-seventh of a volume, and on adding another half volume of oxygen gas, it may be detonated again, ~~ ite Se | 1824.] Onthe Combination of Potassium and Oxygen. 205 and the whole disappears. Thus it cannot be consumed com- pletely by two different proportions of oxygen gas, which dis- tinguishes it from phosphuretted hydrogen gas. The effect produced by subliming sulphurin this gas shows that it contains its own volume of hydrogen gas. Hence the hydrogen in a volume of it will require for combustion half a volume of oxygen gas. The remaining 0°75 volume of oxygen eas must have combined with the phosphorus vapour, and con- verted itinto phosphoric acid. Now phosphorus vapour requires for this its own volume of oxygen gas. ‘Thus it is evident that phosphuretted hydrogen gas when left standing over mercury loses one-fourth of its phosphorus, and becomes a compound of 1 volume hydrogen gas.......+++++ 0°0625 8 volume phosphorus vapour. ...... 0°6250 0:°6875 So that its specific gravity is reduced from 0-9027 to 0-6875, and it contains just ten times as much phosphorus by weight as of hydrogen. It is a compound of 4 atoms hydrogen and 3 atoms phosphorus. M. Vauquelin will see from the above statement that the gas in question is not the same as Davy’s gas to which I gave the name of bihydroguret of phosphorus (a harsh term, but expres- sive of the composition of the gas). We may call it, for the sake of distinction, subphosphuretted hydrogen gas. Thus phosphorus and hydrogen gas unite in at least three proportions; viz. Hydrogen. Phosphorus. i? Phosphuretted hydrogen composed of. .. 1 atom + 1 atom 2. Subphosphuretted hydrogen. .,......+. 4 +3 3. Bihydroguret of phosphorus. ........+. 2 +1 I am, &c. Tuomas THOMSON. Articite VIII. On an Anomaly presented by the Combination of Potassium and Oxygen; with some general Observations on Combination. By the Rev. J. B. Emmett. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Great Ouseburn, Aug. 6, 1824, In estimating the specific gravity of oxygen as it exists in different solid compounds, potash presents a remarkable pheno- 206 «Rev. J. B. Lemmett on an Anomaly presented by (Serr. menon. According to the tables in Brazde’s Chemistry, which seem to be generally very exact, the atomic weight of oxygen is 7°53; the atom of potassium is 37°5; its specific gravity *85. Protoxide of potash, by the combustion of potassium in dry oxygen is 45, and its specific gravity is 2°5. Now the volume its weight of abody = ~ : Its Sp. gt. q 37:5 Therefore the volume of an atom of potassium = _— = 44:1], 45 and the volume of an atom of dry potash = 5 = 18. The volume occupied by the atom of oxygen in this compound = volume of potash — volume of potassium = 18 — 44:1] = — 26:11; so that 37:5 parts by weight of potassium occupy a volume which may be represented by 44°11; by combustion, it combines with 7°5 parts by weight of oxygen, and the volume becomes 18; consequently the space occupied by the oxygen 1s negative, i. e. 26°11 of space less than 0, which is absurd, Since the above numbers are the result of the most careful experi- ments, the subject is of great importance, inasmuch as it is a singular anomaly, and intimately connected with the first princt- ples of chemical philosophy. Ifthe particles of all solids be at all times in contact with each other, as | have supposed in all my former papers, so extraordinary an effect cannot result from any known property of combination; for (as 1 have proved in a former paper) if a solid be heated to its fusing point, and its temperature next reduced to the true zero, the utmost possible diminution is + of the original volume; or volume at the melting poit : volume at zero :: 1 : 2; and in the combination of bodies, unless their atoms be very unequal, no diminution greater than this can be produced. ‘Therefore on this principle the effect cannot be produced. By the generally received hypothesis, that the particles of solids are never in contact with each other, the phenomenon may appear to be accounted for; for since the attraction between the two bodies is evidently very powerful, a great diminution of volume may be supposed to take place, since there is no limit to that which may take place, except the distance between the particles, which some philosophers bave supposed to be extrava- gantly large. But here arises a great difliculty: suppose the force of attraction to vary according to any assumed law, the simplest investigation will show that there can he no force of cohesion, unless the particles of the solid actually touch each other; that is, it is only in contact that the particles can be powerfully urged together by a force, which is indefinitely dimi- nished, when the distance between their centers is increased by any indefinitely small quantity. This hypothesis then being opposed to every known principle of philosopliy is untenable. 1824.] . the Combination of Potassium and Oxygen.’ 207 - Boscovich has presented it under a different form, and which, ifit were correct, would readily explain the phenomenon under consideration. He supposes the particles of matter to attract each other, and the force of attraction at all greater distances to be smaller than at nearer distances, and to repel each other, by reason of the elastic force of caloric, the repulsive force dimi- uishing more than that of attraction, when the distances are increased; he supposes that upon the surface of a particle of matter, the repulsive force is greater than the other; hence at a certain distance, there will be an equilibrium, and this will be the distance of the particles from each other. Having made this supposition, he thus accounts for the force of cohesion: the par- ticles, being at that distance from each other at which the oppo- site forces are equal to each other, are at rest. Ifa force be applied which tends to separate the particles from each other, if their distance be by it increased by the smallest quantity, an attracting force resists it, which force is called cohesion, because, since the force of repulsion varies inversely as some higher power of the distance than attraction does, beyond the distance at which there is an equilibrium, the force of attraction is greater than the other. Were this hypothesis accurate, the phenome- non might be explained; but there are many serious objections to it. When particles are balanced by the equilibrium of two opposite forces, they will constitute a liquid, but never can form a solid; because they have perfect freedom of motion round each other, will yield to every impulse, arrange themselves so as to have a horizontal surface, by the action of gravitation, and press upon the vessel containing them equally in all directions ; all which are properties of liquid substances, but have no resem- blance whatever to those of solids. Besides, a long rod of metal ought to be visibly stretched by a very small force, and the cohesive force ought to increase continually, until the very instant of its being overcome. Again, suppose the distance between two adjacent particles to lave any assumed ratio to the diameter of either of them, in any given solid; form two equal large solids of the same substance, and suppose the force of ; 1 attraction to vary as p- (D being the distance from the centre) ; place these at such a distance that they shall be similarly situated to the particles of the solid; then if d be the distance between two particles, since in both cases the diameters are proportional to the distances, the force of attraction between two particles : Bin IDF force between the spheres :: = > Dar 50 that unless the attract- ive force vary inversely as a higher power of the distance than the fifth, the attraction between the spheres must be very great; for although no force is visible at the distance d, since the forces are equal and opposite at that distance, the forces must 208 Onthe Combination of Potassium and Oxygen. [Supr. be very great, if so vast an effect as that of cohesion be their difference, when d is very little increased ; and since the repul- sive force is corpuscular, and cannot operate between the large spheres, the force must inevitably be enormously great, if the hypothesis be true ; but none whatever is observed. Again: according to this hypothesis, take away the force of repulsion, and that of attraction is very great, at a distance equal to the distance between two adjacent particles ; increase this distance (by breaking the solid) and the force totally vanishes ; break rods of glass or other brittle matter at different temperatures ; the same effect results ; but at different temper- atures, the particles are at different distances from each other ; therefore this force of attraction ceases to operate at different distances, although the weight of the body does not vary. Nothing need be said to prove that no such force is known to exist; it is totally unlike any force of which we can form an idea; for let a force vary inversely as any power or function of the distance, the only place where a body can attract another in such a manner that by increasing the distance by the smallest quantity, the force shall vanish or be indefinitely reduced, is on the surface; but here we have to suppose one at a distance, which cannot result from a variation according to any function whatever of the distance (except the force increase directly as some power of it, then cohesion would be produced at an infinite distance), and this is not the only difficulty, for we have to sup- pose this distance to be moveable. Hence this hypothesis is more untenable than the other. Therefore we must suppose the particles of solids to be in contact with each other, and upon this hypothesis it is impossible to see how the phenomenon in ques- tion can be produced; in fact, there is no parallel. In no case of combination, where one of the bodies is solid, do we meet with a condensation nearly so great as in this instance. Even were we to suppose the particles of solids not to touch each other, the condensation so very much exceeds that which takes place in every other case, that we should naturally expect to find some peculiarity in potassium, which gives rise to the anomaly, which certainly appears to favour the supposition that potassium is a compound of hydrogen and a base hitherto unknown. However, future experiments only can ascertain the cause of so singular a phenomenon; and until experiments point out the cause, whatever is supposed at present must be very uncertain and unsatisfactory. 1824.] Capt. Beaufoy’s Aerial Excursion. 209 ArTICLE IX, An Account of some Observations made during a late Aerial Excursion. By Capt. Beaufoy, Coldstream Guards. (To the Editors of the Annals of Philosophy.) GENTLEMEN, London, July 31, 1824. I po myself the pleasure of forwarding you an account of some observations which I made during a late aerial excursion ; and if you should think it worthy of insertion in the Annals of Philosophy, 1 cannot but feel much flattered at such a circum- stance. Ihave the honour to be, your obedient servant, Mark Beavroy. —=I— On Thursday, the 17th of last June, at five minutes past six in the evening, the balloon rose from the gardens of White Conduit House, Islington ; the barometer being then 29°8 inches, the thermometer 66°, and the hygrometer 17° dry. Wind very high from the north. { felt no motion whatever! All objects seemed to sink from the car; and inashort time quite lost their altitude. At eight minutes past six, the barometer was 27:4 inches, or 2257 feet, thermometer 46°, hygrometer 15° dry, when every thing was perfectly distinct, but flat like a military map; and at twelve minutes past six, barometer 25°5 inches, or 4235 feet, thermometer 45°, we passed through some thin mist. The balloon soon after entered a different current of air, which caused it to make about half a revolution, slowly ; occasioning a slight sensation of sickness, that went off in one or two seconds, when the machine became steady. At sixteen minutes past six, barometer was 23°3 inches, or 6605 feet, thermometer 39°, hygrometer 20° dry, when the machine became enveloped in clouds ; which were by no means dark, nor had the approach to them been gratifying. Soon after a disagreeable sensation of singing in the ears was felt by Mr. Graham and myself, and continued the whole voyage; the application of cotton not removing it. ntil this moment, every thing had been distinctly visibie from the balloon; trees, houses, ships, &c. had length and breadth, but no height. Roads seemed like footpaths of an orange-colour, fields of corn as if ruled with lines of vivid green ; the hedges looked thicker and darker. On rising above the clouds, a most magnificent sight met the eye! One vast expanse of frozen snow, with enormous masses towering above the rest like mountains, having every summit New Series, vou. vii. P 210 Capt. Beaufoy’s Aerial Excursion. [Sepr. burnished by the rays of the sun, which shone most brilliantly from a sky of a deep-blue colour. At twenty minutes past six, barometer 21:6 inches, or 8608 feet, we heard the report of a cannon, but no reverberation after it; and the balloon again revolved gently. At twenty-six minutes past six, when the barometer was 20:2 inches, or 10,416 feet, another gun was heard; and the clouds below rolled over each other into the most fantastic shapes, while between their fissures the earth was clearly discernible. At thirty-one minutes past six, barometer 19-5 inches, or 11,298 feet, thermometer 32°, hygrometer 25° dry, I let loose a pigeon, which flew away with ease and rapidity, its wings mak- ing a great noise from the perfect stillness around. After one or two circles, it darted through an opening in the clouds; and I was assured by the owner that it reached its nest in the City- road at twenty minutes past seven o’clock the same evening. At twenty minutes to seven, barometer 19-2 inches, or 11,711 feet, thermometer 32°, hygrometer 31° dry, Mr. Graham judged we were as high as we could ascend without throwing out ballast ; and as we were far above every object interesting to the ey@g, the cord of the valve was slightly pulled, and we commenced an extremely gradual.descent. At this elevation, 757 feet higher than Moutt Etna, & heard the report of a gun, and could distinguish the metropolis when clouds did not intervene. The balloon seemed to be over Kennington, and I found nothing disagreeable in looking about, except at objects perpendicularly under the car. By: At eighteen minutes to seven, the barometer was 19°5 inches, or 11,271 feet, and thermometer 31°; when our descent was so imperceptible, that it could only be ascertained by throwing out very little bits of silver paper; and I in vain endeavoured to find out from the compass the direction the balloon was taking ; as though the needle pointed north, it could not tell whether we floated to or from that point. At nine minutes to seven, the barometer was 22°3 inches, or 7784 feet, thermometer 38°, and hygrometer 23°, when we approached the clouds ; which had a most beautiful effect from the masses of vapour seeming to rise up in eddies to meet us. At five minutes to seven, barometer 24 inches, or 5822 feet, the machine was quite enveloped in a thick mist, which, at four minutes to seven, barometer 24-5 inches, or 5263 feet, became dark; and gave rise to an unpleasant feeling, of floating in space without any defined objects to rest the eye on. The voice also appeared much weaker and lower than at any other period of the voyage; but I did not feel any oppression at the chest, as I coughed two or three times on purpose to ascertain whether it pained me. At seven o’clock, barometer 25 inches, or 4714 feet, we 1824.] Capt. Beaufoy’s Aerial Excursion. 211 emerged from the clouds; and getting into a new current of air, the balloon turned round again. At three minutes past seven, barometer 26°5 inches, or 3130 feet, every object on the earth became perfectly distinct; and Mr. Graham let down his grap- pling iron, at the end of a cord 160 yards long. At seven minutes past seven, barometer 28°3 inches, or 1385 feet, thermometer 50°, hygrometer 22° dry, the height of houses and trees became apparent; and one minute afterwards, the grapple having caught in the boughs of an oak, brought the car to the ground with considerable violence ; and after rebounding two or three times, Mr. Graham and myself stepped out without any difficulty into a field near Godstone. In this aerial excursion, | was much surprised to find the atmosphere become drier as we ascended, except only at the height of 2257 feet. After our descent, I had occasion to use my handkerchief, when the sound in my ears was like the report of a pistol. The balloon was 63 feet high, by 374 in diameter, which lemon-shaped figure contains 46,388 solid feet; and as each cubical foot of common air equals 1+-0z. the whole weighed 3479 lbs. But the inflammable airgused, was 21 lighter ghan commonair; therefore, te ig SO extew 2 of 3479 = 1392 lbs. weightofgas “fs . * 630 lbs. weight of silk, car, aeronattgisse. "2022 lbs. total weight suspended, which, deducted from 3479 lbs. givés 1457 Ibs. for the power of rising. Now the highest point we attained was 11,711 feet, at which elevation the density of the air is *652; and by calculation, it appears, we might have reached 14,142 feet without lightening the machine at all; but if 150 lbs. had been thrown out, to the height of 16,146 feet, or rather more than three miles. It does not seem probable that any individual was ever raised in a balloon much beyond this last point. First, because that belonging to Mr. Graham, in te I ascended, is larger than those generally used; and secondly, the inflammable air becomes so much distended in the rarer atmosphere above, that a great deal escapes out of the safety valve, and more is expended in accomplishing the descent ; so that on approaching the earth, the balloon collapses, and falls with an alarming rapidity. It is true that many balloons are supposed to have reached a far greater elevation; and one French gentleman was particu- larly fortunate in that respect. But, perhaps, the gas he used P2 212 Le Comte de Bournon on (Serr. to inflate the silk was seven or eight times lighter than common air, which would of course make a great difference ; though as the second objection of the machine collapsing on appruaching the earth could not be got rid of, I am apt to believe him wrong in his calculations. ARTICLE X, Description of the improved Goniometer of M. ddelmann.* (With a Plate.) Tur first goniometer was that of Carangeot, which was made under the direction of Romé de Lille, who niay justly be regarded as the father of crystallography. This instrument (the only one ever used by Haily) was much improved by M. Gillet de Lau- mont, who increased the size of the semicircle, and made the divisions more sensible, but still it partakes of the imperfections of the original instrument. One of these consists in the diffi- culty of placing the two legs of the instrument perfectly perpen- dicular to the edge which unites the two planes of a crystal, whose angle of incidence we wish to measure ; another in plac- ing them on the faces of the crystal, so that the whole flat sur- face of the legs, and not merely their edges, shall touch the face of the crystal in every point, without which it is impossible to obtain an accurate measurement. “ The reflective goniometer, for which we are indebted to Dr. Wollaston, to whom the sciences owe so many other obliga- tions, isa much more perfect instrument, but it requires condi- tions in the crystals to be measured by it, not easily met with ; such as perfectly plane faces, free from strie, and sufficiently brilliant to reflect the light in such a manner as to present a distinct image of the lines of observation. If we attempt to measure a crystal with this instrument, whose faces are striated, however slightly, which unfortunately is but too commonly the case, or which are not perfectly flat, we may be certain of obtaining results more or less inaccurate—a circumstance which itseems to me has already often occurred.+ I admit, however, * Extracted from the Memoir of M. Le Comte de Bournon. + The author of the Review of the third edition of Phillips’s Mineralogy (Journal of Science, vol. xv. p. 324) seems to entertain very different notions of the merits of the reflective goniometer from those of Count Bournon, ‘The review contains a copy of Mr. Phillips’s elaborate figure of a crystal of humite, selected, says the author, “first, because its form has never been described before;’’ secondly, Count Bournon, in his Catalogue, says, that ‘¢ all its planes are striated, whereas not one of them is so; for what he mistook for strive, are, in fuct, so many planes, as has been proved by subjecting the crystals to the reflective goniometer ; thirdly, it shows, therefore, the value of that instrument in astriking degree, and that the use of it quickens the sight of the observer, who, while measuring without a glass, finds planes, where an old, and generally sup- ’ posed accurate observer saw only sirie.”—-J. G. C. ho 2998) -erlt ao. ui Pulecct brig + oleds T.4 oie i ND SE vs ny 1824.] Adelmann’s improved Goniometer. 213 that as this instrument can only be destined (ne peut étre destiné) to establish the primitive form, the type of all those which the observed object can present, and which serves as the basis for calculating all the secondary faces, a single crystal of the sub- stance, although very small, which fulfils all the necessary con- ditions, would be sufficient; still, however, some secondary planes are requisite to determine the dimensions, and, in a great number of substances, especially if they do not admit ofa perfect and easy cleavage, such a crystal is yet to be sought for.” “M. Adelmain’s goniometer has none of the inconveniences of the instruments I have mentioned, and, moreover, possesses advantages which in them are wanting. 1 consider that I shali do a service to the science by describing it, and the manner of using it.” The instrument consists of a small mahogany box, (1) see Plate XXX, eleven inches long, six wide, and three high, con- taining a drawer (2). The top of the box (3) is covered with a plate of brass, at least two lines thick, to prevent its springing, and to render the base sufficiently heavy. The rest of the instrument is made of brass. Two pillars (4), nine lines in diameter, and at least four inches and a half high, are fastened to the brass plate, at the distance of three inches from each other, and are united and fixed at the upper end by a plate (5). At the top of each column is a box (6) in which a steel rule (7), seven lines wide and one line thick, moves horizontally ; the rule is placed edgeways, in order to render its motion more smooth and regular. For the same purpese, each box has a roller at the bottom, on which the rule slides. A semicircle (8) is fixed to the rule by its diameter, the length of which is six inches, four lines, and its broad part (9) seven lies wide. The semicircle is not in contact with the moveable rule, but separated from it by an interval of about three lines. This interval is necessary on this side of the semicircle, in order to adapt to the other extremity of its axis (10) the moveable radius (11), which, at its upper end, carries the nonius (12). On this first semi- circle, which is fixed, is placed a second, divided into degrees, minutes, and half minutes, which, from its size, are perfectly distinct. The second semicircle (13) is fixed by its radius (14) to the centre of the first, and is moveable; but its motion on the fixed semicircle is perfectly smooth, and free from jirks. The radius of the moveable circle is produced beyond the centre, by a steel arm (15) adapted to it, which may be called the measuring radius. The part (16) of the fixed semicircle is necessary to enable the moveable nonius to travel round the moveable semi- circle. A screw (17) placed behind the nonius serves to fix it at pleasure ; (18) is a button for moving the graduated semi- circle. Two detached pieces are added to this instrument; one of 214 On Adelmann’s improved Goniometer. (Seer. them (19) is a support with a hinge, to receive at its upper _ extremity the crystal to be measured (21); this support slides in a groove (22) in order to bring it nearer to, or further from, the ‘measuring radius, or to withdraw it altogether. The other (20) is a sight-vane, by means of which we can ascertain, after the erystai is fixed on its support, if the edge which separates the two planes, whose incidence is to be measured, be ina perfectly horizontal position. To use the goniometer, we place the crystal on the support, in the position just mentioned, then slide the support along the groove, till the measuring radius lies exactly above it, and turn the graduated moveable semicircle, having previously removed the nonius (12) that its motion may be unobstructed. The rest of the operation consists in placing the arm of the measuring radius very accurately on the plane of the crystal, which is opposed toit. This is done by moving the rule (7) to which the semicircle is fixed; and to do this more easily, and avoid jerks, it is necessary to use both hands, one placed at each extremity of the rule.* Ifthe radius be not placed exactly on the face of the crystal, it is to be gently withdrawn, in order to elevate or lower the moveable semicircle, which is to be done in like man- ner, by using both hands, seizing with one the extremity of the measuring radius, and with the other, the opposite extremity of the moveable circle, till the measuring radius lies so evenly on the face of the crystal, that no day-light can be seen between them when examined with a lens. That done, the moveable nonius (12) is lowered till it meets the stop (23) placed at zero of the moveable semicircle, and fixed by the screw (17). The support is then to be withdrawn, in order to pass the measuring radius on the other side of the crystal, when it is replaced, and the business finished, by repeating on that face of the crystal the same operation as was performed on the other.. The value of the angle of incidence of the two planes, in degrees and minutes, is then read off on the graduated semicircle and its nonius. The instrument is represented in the figure as having finished its operation on one otf the faces of the crystal, and with the nonius fixed. The use of this goniometer is very easy; it has the advantage of being fixed, and of not depending for the accuracy of the observations on the manual dexterity of the observer ; nor does it require that perfect brilliancy of surface, in the crystal to be measured, which it is often so ditticult to find. As the measur- ing radius, when once placed on the face of the crystal, remains * A regulating screw, with its carriage, was at first used to adjust the motion of the rule, as shown in the figure, at the place where it was fixed ; but it was found not to be necessary, as the adjustment can be made quite as accurately, and much more quickly by hand, provided the rule itself, and the rollers on which it slides, be made perfectly true. a 1824.| Remarks upon Mr. Daniell’s Work on Hygrometry. 215 fixed in that position till the obverser changes it, if his eyes be fatigued by the operation, he can leave it as long as he pleases, and examine the accuracy of his work at a future occasion, or have it verified by an assistant. ‘Tbe great condition necessary, is that the faces of the crystals be perfectly plane, which unfor- tunately is not always so easily fulfilled as might be wished. ArTICLE XI. Remarks upon Mr, Daniell’s Work on Hygrometry. (To the Editors of the Annals of Philosophy.) As none of the Scientific Journals in their notices of Mr. Daniell’s work on Hygrometry make any remarks on a part of that work which, if I mistake not, is erroneous, I beg leave to direct the attention of your readers to the subject. A principal object with Mr. Daniell, is the application of his improvements to the correction of the barometer when that instrument is used for ascertaining the heights of mountains ; but it is not alittle surprising that he should have erred in his manner of computing what is commonly the greatest and most important correction required in using the instrument. That to which I allude, is the compensation for difference of temperature at the two stations, which Mr. D. considers as a case of apparent dilatation of the mercury, and gives, for the purpose of correction, a table calculated by Mr. Rice, from the results of Dulong and Petit’s experiments: now, besides that the last mentioned gentlemen are egregiously wrong in their way of deducing the apparent expansion, it is not only inappli- cable to the present case, but is as a standing number quite use- less for every other purpose, varying as every one knows. It has always been understood that, other circumstances being alike, mercury in the barometer will have its altitude affected by the existing temperature in no other way than as that tempera- ture alters its specific gravity ; so that whether the tube expand or contract, or were it possible, do neither, whatever the material of which it is made, whatever its sectional form, equality or inequality of calibre, still the absolude dilatation and not the appa- rent must regulate the correction for difference of temperature. After a detailed account of the many operations gone through by Mr. Daniell and his fellow-labourer Mr. Newman, while making a barometer for the Royal Society, during which every thing is done to attain accuracy, we are told that “a scale is engraved on the front, of the correction to be applied for the dilatation of the mercury and the mean dilatation of glass, by which the observation may be at once reduced to the standard 216 Remarks upon Mr. Daniell’s Work on Hygrometry. (Sur. temperature of 32°;” that is to say, the barometer for the use’ of the Royal Society so carefully made, is to have its observed height corrected for temperature, by using the constant denomi- nator 11,664 (64:8 x 180) for each degree of Fahrenheit, or by Mr. Rice’s table. This number, however, has no connexion with the computation in question, for seeing that Mr. D. is partial to Dulong and Petit, their number 9990 (55:5 x 180) ought to have been Mr. Daniell’s choice ; and with regard to the mean dilata- tion of glass, repeated so mal da propos, D. and P. take no mean whatever, asserting its uniformity, and besides do not deduce the number which Mr. D. ought to have used from any such consideration, but on the contrary and conversely, use that num- ber and the apparent dilatation falsely taken, to find that of glass, where they again err. At pages 358—9 examples are given for the various correc- tions, but all those for temperature are on the same erroneous principle as that engraved on the instrument; and previously, page 183, there occurs one where =, seems to be taken as the fraction of dilatation. This example I profess not to understand, unless it be intended to show that we may take any number at random for this correction. In taking the liberty of making these remarks on Mr. Daniell’s meritorious work, it may be admitted that, though he and Mr. Rice have inadvertently assumed 2... as the fundamental number on a false principle, still it may not beso far from the truth as it might have been, since the absolute dilatation of mercury is given so variously, that in adopting the right principle, Mr. Daniell might have a number still more erroneous. Important as a knowledge of the real amount of the dilatation of mercury would be, in many scientific determinations, in none perhaps is it of such consequence as in this correction for the mountain barometer, respecting which, nevertheless, there is too much cause for regretting that, even in this age of refined experimental knowledge, we are so embarrassed with conflict- ing authorities, as to be forced to entertain more than a suspicion that the real quantity is still unknown. Mr. Dalton calls it 2, ; Dulong and Petit —.,; and General Roy 4, ; while philosophers, of equal and undoubted reputation, vouch for the authenticity of almost every intervening denominator, and some for even a greater. If such be the actual state of our knowledge with regard to the quantity of the absolute dilatation of mercury, it is difficult to conceive how Mr. Daniell can so confidently assert, that “this effect has been most minutely appreciated, and its correc- tion applied with the utmost ease and precision.” M. Biot fixes this number at 5!_., which is generally received in France, and by many here; yet even this celebrated philosopher is wrong, by having made a false conclusion from his own pre- 1824.] Remarks upon Mr. Daniell’s Work on Hygrometry. 217 mises, Traité, tome i, page 52. From what he there states, a different number ought to have been obtained; and the error affects many of his subsequent formulz relating to the barome- ter, expansion of fluids, of gases, &c. {n common with many others, Mr. D. seems to think that boiling the mercury in the tube of a barometer is of great con- sequence ; this is at least doubtful, but certain it is that no human art can render a mass of this fluid such mere mercury that it shall not contain something, which in all its mechanical effects may not be called air. Sir H. Davy is in the right when he says so; and it is not a little to his credit to have perhaps by induction inferred that such is the fact, when there is no reason to think him aware of certain proofs to which it were needless here to appeal. Mr. Daniell speaks also of filtering the mercury ; though per- formed a thousand times no good effect can follow this practice. A knowledge of this metal gained from a peculiar application of it, warrants the assertion, that the mercury of commerce is not improvable by either distillation or filteration, in so far as its application is purely mechanical, and that its fitness for baro- meters can be completely known by bare inspection. There is a probable source of error in the barometer hitherto little attended to, and of which Mr. D. takes no notice; in making the correction for temperature, it has ever been taken for granted, that the expansion proceeds par? passu, or that the fraction of dilatation is, for example, the same from — 20 to — 30, as it is from 90 to 100. This is, however, quite a gra- tuitous assumption ; and although there are reasons for here suspecting something different from the utmost degree of pre- cision, itis possible that the experimental means which we at present possess are inadequate tu ascertain any appreciable discrepancies. Much learning has been brought to bear on the other cor- rections requisite in using the mountain barometer ; and Mr. Daniell could not have conferred a more substantial benefit than by having set the question at rest, as to the absolute dilatation of mercury, without a certain knowledge of which, all other minute attentions are little better than mere drivelling. Mr. Daniell’s account of the manufacture of barometers and thermometers is most certainly not overcharged. Throughout the continent, and even in England, the business is im the hands of itinerant Piedmontese; and these artists supply not only the general public with their glittering baubles, but furnish the greater part of the most reputable instrument-makers with their whole stock of meteorological wares. Such of these as choose to graduate their own scales, must confide entirely as to the quality of their tubes and the excellence of the filling, in one who has but indirect interest in the matter, or equivocal 218 M. Gay-Lussac on the Chloride of Lime. [Sepr. reputation to lose; responsibility is thus shuffled from both, and rests on neither. Such, however, are the people who by unaccountable prescription supply the city cf London, and the philosophers of England, with the instruments which Mr. Daniell so well describes. If common notoriety did not bear Mr. Daniell out in his as- sertions, the shameful disagreement of the thermometers used by Captain Parry in his last voyage, would fully do so. On one occasion this amounted to no less than 13 degrees ; Capt. Parry could do nothing else than give a mean, though im such a case — 48° had as good a chance of being the truth as — 35°. ARTICLE XII. Insiructions for the Assay of Chloride of Lime. By M. Gay-Lussac.* THe uncertainty which has hitherto existed in the modes of ascertaining the quality, and consequently the commercial value of chloride of lime, and in no small degree retarded its coming into general use, has determined me to publish the following instructions on the subject. I shall divide the work into two parts ; in the first 1 shall expose the principles on which the assay of the chloride of lime is founded, and in the second L shall describe the instrument which I call a Ch/orometer, and the manipulations necessary for making the assay with sufficient accuracy for the purposes of those arts in which chlorine is employed. PRED Principles on which the Assay of Chloride of Lime by means of Indigo is founded, It is known that chlorine destroys vegetable colours, by form- ing new compounds with their component principles. It is in consequence of this property which it possesses, whether im the state of gas, in solution in water, or in combination with an alcali, that it is employed in the arts of bleaching, calico print- ing, &c. The same quantity of chlorine, in either of those three states, destroys the same quantity of colouring matter; and since by combination with an alcali, it becomes fixed, has scarcely any smell, keeps better, is more portable, and more capable of concentration, the advantages of preparing it in that form are obvious. Caustic potash, soda and lime, and even their carbonates, combine very readily with chlorine. Its combination with the * From the Annales de Chimie. 1824.] M. Guy-Lussac on the Chloride of Lime. 219 potash, or soda of commerce, has long been known in France by the name of eaw de javelle ; that with lime was called oxy- muriate of lime ; but it is more accurate to denominate the first, as is now generally done, chloride of potash or soda, and the latter chloride of lime. The chlorides of potash, soda, and lime, have very little sta- bility of composition ; the two first, indeed, can only be obtained in the liquid state, in a large quantity of water. If, for instance, we pass chlorine into a concentrated solution of potash, at first chloride of potash will be formed; but this chloride will soon be decomposed, and converted into chlorate of potash, and chloride of potassium. The two latter compounds, not having the pro- perty of destroying colours, must be avoided, and the only means of preventing their formation is to employ:a very weak solution of the alcali, which, at most, should not exceed the proportion of 125 grammes to a litre of water. (In round num- bers, about 44 oz. potash to 24 pints of water.) Lime has not, like potash and soda, the inconvenience of con- verting the chlorine into chloric acid ; it may consequently be combined with the chlorine en masse. Lime, if perfectiv dry, does not absorb chlorine, but it com- bines with it rapidly when in the state of hydrate, that is, after it has imbibed a sufficient quantity of water from a moist at- mosphere, to split and fall to powder. Supposing it to be in the state of hydrate, it forms, according to M. Welter, a sub- chloride only, which is composed of 2 proportions of lime = 2x 35:603 8 =>) 71-206 2 water = 2 x 11°:2485 = 99-487 1 chlorine = 44-2653 137°9583 When mixed with water it is immediately decomposed; one half of the lime is precipitated, and the other half remains in solution, combined with the whole of the chlorine, and conse- quently forming a neutral chloride. Hence there are two com- binations of chlorine with lime, a sub-chloride, and a neutral chloride. ‘The sub-chloride is obtained by saturating hydrate of lime with chlorine, and the neutral chloride by dissolving the sub-chloride in water, or by saturating lime, dispersed through water, with chlorine. The neutral chloride, or more simply the chloride, is very soluble ; it may, however, be made to crystallize in small prisms. Its solution, left in contact with the air, is gradually decom- posed, one part of the lime combines with the carbonic acid of the atmosphere, whilst its chlorine is disengaged. This de- composition of the chloride is retarded by constantly keeping an excess of lime in the solution. From these properties of the 220 M. Gay-Lussac on the Chloride of Lime. [SEprv. chloride, the advantage of manufacturing the sub-chloride only is obvious; its preservation and transport are much more easily effected. The quantity of chlorine in combination with water, or a base, may be estimated by several processes; but im the arts, in which dispatch is important, the preference has been given to M. Descroizilles’ process, founded on the property of chlorine to discolour indigo. One part of indigo dissolved in 9 parts of concentrated sulphuric acid, and then diluted with 990 parts of water, forms the coloured liquid usually employed to ascertain the quality of the chlorine. Under the same circumstances, chloride of lime discolours a quantity of this solution proportionate to its own; but if they vary, the results also are very variable. Thus, if we pour the chloride s/owly into the indigo, a much smaller quantity of it is necessary to effect the discoloration than if we proceed dif- ferently. The minimum of discolouring effect, is obtained by pouring the indigo very slowly into the chloride, and the max- imum by pouring the chloride very slowly into the indigo. Re- peated trials have proved that the best process for obtaining constant and comparable effects, is to pour the solution of in- digo rapidly into the solution of chloride, or the latter into the former. I shall explain the mode of operating by and bye. If the indigo of commerce were pure, or always of the same quality, the quantity of its solution employed m each assay would give the relatiye quality of the chloride; but since its quality is very variable, the results of trials made with different indigos cannot be compared together. To avoid these incon- veniences, I have followed the example of M. Welter, and taken as unity of discolouring power that of pure, dry, chlorine, at the barometrical pressure of 0°76 m. (29°92 inches,) and temperature of 0°. (82 Faht,) I prepare a solution of any of the best indigos of commerce of such a strength that the chlorine discolours exactly ten times its volume of it, and I call this solution the proof tincture; and each volume of proof tincture that is dis- coloured I call a degree, and I divide the degree into ten parts. Thus, if we take 10 grammes* of chloride of lime and dis- solve it in such a quantity of water as to form 1 litre of solution, the number of degrees, or volumes of indigo discoloured hy one volume of the solution of chloride, will indicate the number of tenths of a litre of chlorine that the solution contains. Con- sequently, 1 kilogramme+ of chloride of lime, whose quality had been determined by this method, and found to be of 7:6° or =45,ths, would contain 76 litres of chlorine. Each degree therefore is equal to 10 litres, per kilogramme of chloride, and each tenth of a degree to 1 litre. Supposing the sub-chloride * Or 1 decagramme, Tr. + Or 100 decagrammes, Tr. 1824.] M. Gay-Lussac on the Chloride of Lime. 221 of lime to be perfectly pure, and formed as stated in page 219, it contains per kilogramme 101:21 litres of chlorine. The base I have adopted appears to deserve the preference, from the simplicity and precision of expression that it admits of in chlorometry, which may remain unchanged, whatever means may be used to measure the strength of the chlorine. We obtain more precision in general with a weak solution of chloride, marking for instance 4 or 5 degrees, than with a very concentrated solution. [f, therefore, onthe first trial we find that the chloride much exceeds 10°, we must add a known volume of water to the solution, for instance, twice its bulk; we then make a fresh trial, and triple the number of degrees obtained to get the true value of the chloride. Assay of the Oxide of Manganese. The purity of the oxides of manganese, employed in pre- paring the chlorine, is very variable, and consequently that of any particular ore must be ascertained by experiment, which may be easily done in the following manner. Pure peroxide of manganese is formed of, Manganese ............ 3°5578 grammes RORMTEDL tise,» nine 6 eat otabi ig STU 55578 and furnishes 4:4265 gram. of chlorine,-oy 1°3963 litre, at the temperature of 0°, and under a pressure of 0°76 m ; consequently 3°980 gram. would produce 1| litre of chlorine, and 1 kilogramme would produce 251:23 litres. We take, therefore, 3°98 gram. of the oxide of manganese which we wish to assay, and treat it with muriatic acid, with a gentle heat, receiving the disengaged chlorine in rather less than alitre of milk of lime ; towards the end of the operation we make the acid boil, to drive the chlorine from the vessels into the milk of lime, and add water to make its quantity just one litre. The quality of this chloride will exactly give that of the oxide of manganese. The value of the manganese does not depend wholly on the quantity of chlorine it is capable of furnishing, but also on that of the muriatic acid required for its production. But the ope- ration is delicate, and the low price of muriatic acid makes it unnecessary. I shall only remark, that the peroxide of man- ganese often contains the carbonates of lime, barytes, and iron, which saturate to mere loss a portion of the muriatic acid; moreover, as the manganese is not always in the state of per- oxide, the quantity of muriatic acid required will not in that case be proportionate to that of the chlorine obtained. 222 M. Gay-Lussac on the Chloride of Lime. — [Surpr. Parr II. Description of the Chlorometer, and of the Method of proceeding in the Assay of the Chloride of Lime. A. (Plate XX XI.) Small balance. B. Weight of 5 grammes. C. Mortar to pulverize the chloride of lime; by this opera- tion we ensure greater accuracy in the assay, as the chloride often contains lumps which dissolve slowly. D. Jar, with a foot, containmg exactly half a litre when filled to the circular line m, terminated by two opposite arrows ; the surface of the water must coincide with this line, and not its upper edge, which is indicated in the figure by the dotted line. The jar must be placed on a horizontal table. E. Stirrer, to stir the solution of the chloride and make it homogeneous: it is to be plunged down into the liquor, and raised up again, alternately, without being taken out of it. F. Small measure, or tube, of 2+ cubic centimetres, which is unvarying for the chlorometer in question; it is intended to measure the solution of chloride of lime. ‘To fill this tube, it is plunged into the chloride to just above the circular line n, which terminates its capacity, and the chloride made to rise in it by suction; when filled, the fore finger, which should neither be too dry nor too wet, is placed on the upper orifice, the tube raised out of the liquid, and its lower extremity supported against the margin of the jar, as seen at G, or against the finger. By a little management of the pressure, and a slight alternate circular motion of the stem between the fingers, the liquid de- scends slowly, and when the lower part of the concave curve which terminates it is in the plane of the little circular line, the stream is immediately stopped, by increasing the pressure and the tube emptied into the drinking glass H.* H. Large drinking glass for mixing the indigo proof tincture with the chloride. It should be placed on a sheet of white paper, in order more easily to observe the changes of colour which the indigo undergces by the action of the chlorine. I. Tube for measuring the proof tincture: each great divi- sion, or degree, is equal to the capacity of the smali tube P, and is divided into 5 parts, which is sufficient for practice ; but for calculation, the fifths are reduced to tenths. ‘This tube is filled with the proof tincture up to the degree 0, which is easily accomplished, by putting into it rather more tincture than is necessary, and pouring off the excess, drop by drop, by the beak, the extremity of which should be covered by a shght layer of wax or tallow, to assist the running off in drops. * When the tube becomes opaque, it is cleared by dipping it in muriatic acid, or vinegar. pet LM I ! Sve etna = m 1 SF. SHULV, SC, 5 Engraved wor the hinds G LMR MY TT BUA MO RMIK IOV SPD “W2g, pack ; 4 A avila be atin EY 9, ah x mt a es ete oF iN ‘ : ‘“? ‘ tee ; Nis Ch Wie cot wey We oer ait , . 2 2 yy ; ee oe oh a asi _ 1824.] > M. ‘Gay-Lussac on the Chloride of Lime. 923 K. Another tube graduated like I, but in a contrary direction. Its use is to hold the proof tincture which is to be poured briskly into the chlovide, For conveniently obtaining the de- sired volume of the tincture, the tube L, drawn out toa point at its lower end, is employed; the excess of tincture is removed by plunging the tube to the necessary depth into it, and closing the upper orifice with the finger before it is withdrawn ;_ in the same manner a deficiency may be supplied from the vessel con- taining the indigo. Preparation of the Solution of Indigo, and of the Proof Tincture with that Solution. Take a determinate quantity of indigo, sifted through a silk Sieve, put it in a matrass with nine times its weight of con- centrated sulphuric acid, and heat it in a water-bath, at the temperature of boilmg water, for six or eight hours. Dilute a part of this solution with such a quantity of water that 1 volume of chlorine may discharge the colour of exactly 10 volumes of the solution: this will be the proof tincture. The simplest, and at the same time sufficiently accurate methed of preparing a liquid containing its own volume of chlorine, is to take 3:98 gram. of well crystallized manganese, and treat it with muriatic acid, receiving the chlorine in milk of lime, whose volume is to be reduced to that of 1 litre after the operation, as mentioned in the assay of the oxides of manganese ; but if we wish to ope- rate with the utmost accuracy, the chlorine must be prepared in the state of gas, and absorbed by water in which a little lime has been infused ; the temperature, pressure, and moisture of the gas being noted. Important Observation. The proof tincture, being gradually discoloured by light, must be carefully kept secluded from it in stone jars ; but for the use of the chlorometer it may be preserved in a half litre glass phial, always taking care not to expose it to the direct rays of the sun: it had better be kept in a dark closet. Process of Assaying the Chloride. Take several specimens from the mass of chloride to be exa- mined, and weigh off 5 grammes, and pound them in the mor- tar, with a sufficient quantity of water to make thin cream ; then dilute it with more water, and decant it into the half-litre jar. In order not to lose any liquid in this operation, rest the edge of the motar against the pestle, as seen in the figure D. Triturate the residual chloride remaining in the mortar with water, and decant as before, and repeat these operations till no more is left in the mortar. Rince it out and pour the rincings 224 M. Gay-Lussac on the Chloride of Lime. [Supr. into the jar. Make up the volume to exactly half a litre, and stir it to render it perfectly homogeneous. Fill the tube (I) with proof tincture up to 0°, and pour a portion of it, less than that which you suppose will be discoloured by the chloride, into the glass H, for instance, 5°. Take one measure of chloride in the small tube F, and make it flow quickly into the proof tincture, by blowing into the tube, agitating the mixture the whole time. If the tineture be com- pletely discoloured, add quickly from the tube I, such a fur- ther quantity as to give the liquid a slightly greenish colour; the quantity of proof tincture taken from the tube I, will be the measure of the quality of the chloride, provided the second por- tion added be not considerable, nor amount to three-tenths of a degree. But if the second portion of proof tincture added to the chlo- ride, exceed the quantity of three-tenths of a degree ; if, for in- stance, it amount to 1°2°, the assay must be begun again. Fill the tube I with the tincture, and pour as much of it into the glass H, as is equal to the quantity discoloured in the former experiment, and some hundredths over. Then complete the operation in the manner already described. The assay has not attained the utmost precision it is capable of, till the proof tinc- ture assumes the slightly greenish tint, ¢mmediately on the chloride being added, without a fresh quantity being required. By these successive operations we approach as near as we- please to the true quality of the chloride; nevertheless, I do not think that we can in general be certain of it beyond =,th. These operations may, perhaps, appear complicated, but I must remark, that each of them may be executed in two or three minutes; that when we previously know pretty nearly the quality of the chloride, two operations are sufficient, and that in the current labours of a manufactory one assay will be enough. Moreover, the object is to ascertain the quality of the chloride, in order to fix its commercial value, and in that case we must not be niggards either of our time or our pains. The same process is directly applicable to the assay of a so- lution of chlorine in water; but it is better to begin by adding a little powdered quick-lime to the liquid to convert it into chlo- ride. The tube K, which forms part of the chlorometer, is intended for assaying the chloride, by pouring the indigo quickly into the chloride. For this operation the quantity of tincture re- quired to saturate one measure of chloride must be previously ascertained by the tube I. 'The assay is then begun again by putting into the tube K, a quantity of tincture equal to that which has been discoloured, and a small quantity over, which must be poured quickly into a fresh measure of chloride; as much tincture must then be added 1824.] M. Gay-Lussae on the Chloride of Lime. 225 as is necessary to give the greenish colour, and the assay once more renewed by putting into the tube a quantity of the tincture, equal to that discoloured in the preceding assay. The mani- pulations of this experiment are precisely the same as those of the first; but since the results are similar, and it requires the tubes K and L in addition, I do not consider it as preferable to the former. ———— it may be convenieut to some of our readers if we reduce the French weights and measures employed by M. Gay-Lussac, in the preceding very valuable paper to equivalent English ones. 100 cubic inches of pure dry chlorine, at the mean pressure and temperature of 30 inches and 60° Faht. weigh 75°375 grains, 1 volume of which discolours 10 volumes of the proof tincture. Suppose we take 250 grains of chloride of lime and dissolve it in 100 cubic inches of water, and that we find the value of this solution to be denoted by 7°6°, or, in other words, that 1 cubic inch of the solution discolours 7°6 cubic inches of proof tincture ; then the whole quantity, or 100 cubic inches of the solution of chloride, would discolour 760 cubic inches of tinc- ture, one-tenth of which, or 76 cubic inches, is the quantity of chlorine it contains. 250 grains = 4th of a pound avoirdupois; consequently, lib. of chloride of lime of the above quality would afford (28 x 76) = 2128 cubic inches of chlorine, or rather less than 14 cubic foot, or about 138 cubic feet per cwt. Assay of the Oxide of Manganese. Pure peroxide of manganese is composed of Manganese........ . 28 grains Oxygen leita Edaniesia 16 ie and affords 36 grains of chlorine, or 47°76 cubic inches at mean pressure and temperature ; consequently 92°127 grains will give 100 cubic inches, and | lb. will give 4°397 cubic feet. We take therefore 92°127 of the oxide to be assayed, and treat it as directed, p. 221, receiving the disengaged chlorine in rather less than 100 cubic inches of milk of lime, which, after the operation, must be made exactly equal to that quantity by pure water, and assayed as above. ‘The result will indicate the quality of the oxide of manganese in cubic inches of chlorine per 92°127 grains of ore. To coincide with these weights and measures, the small weight B should be equal to 125 grains: the capacity of the jar G to the arrows, 50 cubic inches, and that of the little mea- sure or tube F, 2, 0f a cubic inch. Each of the large divi- sions on the tubes [and K, must also be equal to (%; of a cubic inch, to correspond with the capacity of the small measure F, New Series, vou. Vili. Q 226 Corrections in the last Number of the Annals. [Surr. To prepare the liquid containing its own volume of chlorine, instead of the 3°98 grammes, &c. p. 221, we must take 92:127 grains of well crystallized oxide of manganese, and receive the chlorine in 100 cubic inches of milk of lime ; and in the pro- cess of assaying the chlorides, (p. 223) we must employ 125 grains of the mixed salts, and decant the solutions into the 50 cubic inch jar D. ‘jaca Se ArticLe XIII. Corrections in the last Number of the Annals. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Aug. 18, 1824. PxeRmMiIrT a constant reader to point out a few oversights that occur among the Scientific Notices in the last number of the Annals of Philosophy, viz. for August. Your candour, added to your wish to render the journal as free from error as possible, will find an excuse for the hberty now taken. 1. In Article 4, p. 140, where the table exhibiting the quan- tity of each chalybeate preparation containing | grain of oxide of iron is given, the numbers that ought to have been attached to Ferri Subcarbonas and to Ferrum Ammoniatum are transposed, and thus absurdly erroneous quantities are set down for these substances. 2. The title of Article 5, p. 140, is erroneous, “‘ On the Use of Nitrous Oxide in Eudiometry.” It ought to be Nitric Oxrde. 3. Article 8, p. 151, “Inflammation of Sulphuretted Hydrogen by Nitric Acid.” In this title, as well as in the description of the experiment, I apprehend that you have substituted nitric for nitrous acid. The experiment is not a new one, and it is not due to Berze- lius. I remember well having seen it above twelve years ago in the lectures on chemistry in the University of Edinburgh, and I am certain that Dr. Hope made use of strong fuming nitrous acid. It may be mentioned by the way that the exhibition is remarkably striking and brilliant when made ona large scale. To the best of my recollection, the Professor, instead of using a flask containing four or five cubical inches of gas, as recom- mended by Berzelius, employed a large wide-mouthed receiver of nearly 200 cubical inches capacity, and poured into it about half an ounce of the strongest fuming nitrous acid, covering the orifice slightly with a piece of paper. The explosion is not violent, but the flame in the interior of the vessel is beautiful. I remain, Gentlemen, your obedient servant, A.B. We thank our friend A, B. for his good opinion of our can- 4 f 1824.] Proceedings of Philosophical Societies. 227 dour, and for the trouble he has taken in pointing out our errors. We hope they are not unpardonable. A. B. is right as to the transposition of the two salts of iron, It should be 1 grain in 66 of ferrum ammoniatum, and 1 in 1-2 of ferri subcarbonas. The erratum respecting nitric oxide has been already marked for correction. The third error, if one, does not originate with us ; the article is copied verbatim from the Journal of Science. ArTICLE XIV. Proceedings of Philosophical Societies. ROYAL ACADEMY OF SCIENCES OF PARIS. Tue Royal Academy of Sciences of Paris not having adjudged the prize proposed in 1822 to any of the memoirs delivered in, decreed in the sitting on the 7th of June last, that the same subject shall be proposed afresh for the prize for 1826, viz. 1. To determine by multiplied experiments the density which liquids, particularly mercury, water, alcohol, and sulphuric ether, acquire by pressures, equal to the weight of several atmospheres; and 2. To measure the effects of the heat produced by those pres- sures. The prize is a gold medal of the value of 3000 francs. The subject for the mathematical prize for 1826, is, A method for calculating the disturbances of the elliptical motion of comets, applied to the approaching return of the comet of 1759, and to the motion of that observed in the years 1805, 1819, and 1822. The prize is a gold medal of the value of 3000 francs. Both these prizes will be adjudged in the public sitting on the first Monday in June, 1826; and the memoirs must be sent in before the Ist of January of that year. The subject for the prize in the class of natural history, for 1825, is, Yo determine by a series of chemical and physiological experi- ments, the nature of the phenomena which successively occur in the digestive organs, during the process of digestion. The candidates will first ascertain the chemical, or other modifications which the immediate organic principles undergo in the digestive organs, particularly those which enter into the composition of food, as gelatine, albumen, sugar, &c. Their researches will next be directed to the alimentary sub- stances themselves, in which several immediate principles are united, carefully distinguishing between liquid and solid aliments, giz 228 Scientific Notices—Chemistry. (Serr. The experiments must be pursued in the four classes of verte- brated animals. The prize is a gold medal of the value of 3000 franes, to be decreed in the public sitting on the first Monday in June, 1825. The memoirs must be sent to the Secretary of the Institute before the Ist of January in that year.—(Annales de Chimie.) ARTICLE XV. SCIENTIFIC NOTICES. CHEMISTRY. 1. On the Means of detecting the Presence of Acetate of Morphia, in Animals poisoned by that Substance. By M. Lassaigne. THE process adopted by M. Lassaigne is as follows :—The contents of the stomach, or the fluid ejected from it, were fil- tered, the fluid carefully evaporated, and treated with boiling alcohol of the specific gravity of ‘837, which separated the ani- mal substances. The alcoholic solution was evaporated to the consistence of an extract, and treated with distilled water, to separate the fatty matter; the solution was then filtered, and deposited, by a gentle evaporation, prismatic crystals at the bottom of the capsule, which possessed the following properties. They had a bitter taste, and were precipitated in white flakes from their solution in water by ammonia; treated with concen- trated sulphuric acid in a small glass tube closed at one end, they exhaled a decided odour of acetic acid: they immediately give a yellow solution with nitric acid, which, with an increased quantity of acid, deepened to orange, and afterwards exhibited a fine reddish-yellow, blood colow. These characters belong to the acetate of morphia, and amply attest the presence of that substance. To free the alcoholic extract from colouring matter, M. Lassaigne poured acetate of lead into its solution in water (as practised by Pelletier in his experiments on strychnia), which threw down the colouring matters, and left the morphia and the excess of precipitant in the supernatant liquid, which was easily cleared of the latter by a few bubbles of sulphuretted hydrogen gas. The solution was then evaporated in vacuo over a surface of sulphuric acid, and the fixed alkaline substances were thus obtained free from colour derived from any foreign matter. The action of nitric acid then readily demonstrated by its orange-red colour the pre- sence of the acetate of morphia. On examining the stomach, intestines, heart, and blood of a cat poisoned by 12 grains of the acetate, the morphia was only detected in the stomach. The thoracic cavity of a dog which 1824.] Scientific Notices—Chemistry. 229 died in 10 minutes after the injection of 14 grains of the poison, contained acetate of morphia, as did also the small intestine of a cat, and the duodenum of a dog, after the poison had been injected into those parts. ; Thirty-six grains of acetate of morphia were injected into the crurai vein of a dog, and 30 grains into the jugular vein of a horse, but none could be detected in the blood, drawn 1+ hour after injection from the opposite vein; but on repeating the experiment, and bleeding the animal in 10 minutes after the poison was injected, it was found in the blood. M. Lassaigne concludes from his experiments, 1. That in many cases of poisoning by acetate of morphia, sensible traces of that vegetable poison may be chemically detected. 2. It is always found in the viscera in which it was first depo- sited. 3. The contents of the stomach, ejected by vomiting soon after the imjection of the poison into it, contain ponderable quantities of the acetate of morphia. 4. All attempts to detect its presence in the blood of animals poisoned by acetate ofmorphia, have been ineffectual.—(Journ. de Pharmacie.) 2. Cause of the Odour of Hydrogen Gas. In our last number we quoted some observations by Berze- lius respecting the oil which communicates to hydrogen gas, its peculiar odour: as the circumstance, although well known to chemists, has been seldom adverted to, we shall lay before our readers a brief account of some facts which had been pre- viously ascertained respecting it. About the year 1800, Proust stated, in a memoir read be- fore the National Institute, that this peculiar odour resides in avolatile aromatic oil, of a bituminous flavour, which is held in solution by the gas; and in support of his opinion, he ad- duced the following facts. 1. During the solution of cast iron in sulphuric or muriatic acid, the neck of the retort, and the sides of the receiver, have a greasy appearance, in consequence of their being coated with minute drops of this oil. 2. When a considerable quantity of metal is dissolved at once, as from 12 to 15 0z., drops of this oil are obtained floating on the liquid in the receiver. 3. The carbonaceous matter remaining after the digestion of cast iron in either of these acids, yields a por- tion of this oil by distillation: alcohol also extracts the oil from it, and the solution is rendered milky by the addition of water. —(Mem. Pres. a’ Inst. des Scien. i. 205.) Vauquelin, about five years after, confirmed the preceding observations, and communicated some additional information respecting the properties of the oil. He prepared it by dissolv- 230 Scientific Notices—Chemisiry. [Sepr. ing cast iron in dilute sulphuric acid, and digesting the residue in very strong alcohol: the solution was filtered while hot, and the alcohol was distilled off with a very gentle heat. Thus ob- tained, the oil was clear and transparent, had a slight lemon- yellow colour, and an acrid taste. It appeared to hold a mid- dle rank between the fat and volatile oils. He remarked the formation of a similar oil during the solution of tin in mumiatic acid.—(Journal des Mines, No, exix. p. 392.) Doebereiner ascertained more recently that hydrogen gas may be rendered completely inodorous, by being kept in con- tact for some time with newly ignited charcoal—(Schw. Journ. iii. 377)—and Mr. Donovan, that the same object may be ef- fected by passing the gas successively through lime water, ni- tric acid, solution of green vitriol, and water. Neither of them alludes to an oil as occasioning the peculiar odour: the latter, indeed, ascribed it wholly to sulphuretted and phosphuretted hydrogen.—(Phil. Mag. xlviii. 138.) Before concluding, we may observe, that although this olea- ginous principle is probably formed invariably during the solu- tion of the sub-carburets of iron, and also of other metals, such as manganese, nickel, &c. which combine with small quantities of carbon, there are besides other circumstances under which the hydrogen evolved during the solution of metals will possess a peculiar odour. This will take place whenever the metals contain traces of phosphorus, sulphur, selenium, tellurium or arsenic. The solution of those varieties of iron, so common in France, which contain phosphorus, is always ac- companied with the odour of phosphuretted hydrogen. Most of the tin which occurs in commerce, even those refined spe- cimens sold under the name of grained tin, occasion the evo- lution of a considerable quantity of sulphuretted hydrogen gas when dissolved in muriatic acid. We think it not improbable that the doubtful compound described by Kastner and others, under the name of stanniuretted hydrogen gas, is nothing else than arseniuretted hydrogen; which, of course, must make its appearance whenever the tin happens to be contaminated with arsenic. This would account for the prejudicial vapours which are occasionally emitted during the solution of tin in muriatic acid, and which are so much complained of by those who pre- pare solutions of muriate of tin on a large scale, for the use of the dyer and calico printer. 3. Selenium, an Attendant of Sulphur. Pleischl (in Schweigger’s Neues Journ. ix. 348,) expresses his opinion that selenium is not an uncommon attendant of sulphur : we are inclined to think, from the observations of Berzelius, Stromeyer, Gmelin, Wahler, Lewenau, &c. that the fact is already pretty satisfactorily established. 1824.] Scientific Notices—Mineralogy. 231 A foreign admixture of this nature would account for the very deleterious qualities which the French chemists ascribe to sul- phuretted hydrogen gas, and for their antipathy against in- haling the slightest particle into the lungs. (Thenard, Traité de Ch. 3d edit. 1.722—729.) That the odour of the gas is suffi- ciently unpleasant must be admitted; but we have repeatedly remained in atmospheres copiously impregnated with it, without experiencing any injurious consequences, and we do not hesi- tate to assert, that the antidote which they recommend, namely, the continual emission of chlorine into the open air so long as the gas is preparing, is a much more serious inconvenience than the one which it is intended to correct. It can searcely be doubted, that their sulphur contained either selenium or arse- nic ; and as Thenard has described this extremely noxious qua-~ lity as one of the inseparable characteristics of sulphuretted hydrogen gas, it appears probable that the contamination is far from unfrequent. MINERALOGY. 4, A Superb Collection of Minerals for Sale. Dr. Joseph Guillaume Waagner, of Vienna, has announced the sale of the superb collection of minerals, late the property of M. Jacques Frederick Von der Niill, deceased. This collection is well known, both for the magnificence of the specimens, and by its having been arranged and described by Professor Mohs, in 3 vols. 8vo. Vienna, 1804. When that work appeared, the collection contained 3926 spe- cimens, exclusive of the cut precious stones which form a valuable collection by themselves, and do not belong to the great collection. Since that time, to the death of the owner in May 1823, the cabinet has been continually increasing, and the number of specimens it now contains amounts to 5047, of which 3427 are ticketted with numbers corresponding with M. Mohs’ catalogue, and the remaining 1620 are briefly de- seribed in a catalogue by M. Partsch. The average size of the specimens is about three in. by two, and they are contained in three cabinets of 48 drawers each. The specimens of gold, silver, and tellurium, and the minerals in general found in the Austrian empire, particularly Hungary and Transylvania, are said to be remarkably fine. The price is fixed at 3000/. sterling, and time will be allowed for payment on satisfactory security being given. Persons wishing to treat for the purchase, are requested to apply to Dr. J. G. Waagner, Hohenmarkt, No. 511, 3°™* étage. 5. New Locality of Tellurium. During a recent arrangement of the collection of minerals be- longing to the Royal Academy of Sciences of Stockholm, there 232 Scientific Notices—Miscetlaneous. [Serr. were observed several specimens of a broad foliated mineral from Riddarhyttan, having a silver-white colour, and the me- tallic lustre. Berzelius instantly recognized it as being iden- tical in its external characters with the mineral first described by Von Born, under the name of molybdenous silver, which Klaproth considered as a sub-sulphuret of bismuth, but which he himself ascertained a few years ago to Le an alloy of bis- rauth and tellurium, mixed with some selenium. (The Use of the Blowpipe, Eng. Tr. p. 152.) The mineral from Riddarhyt- tan proved by a blowpipe examination to contain rather more sulphur than Von Born’s, but the other constituents appeared to be exactly the same, and in exactly the same proportions in both. It is remarkable as being the first instance in which this rare metal has been found in Sweden.—(Kongl. Vet. Acad. Handl. 1823, st. I.) MiscELLANEOUS. 6. Hydrophobia cured by Acetate of Lead. Dr. Fayerman, of Norwich, had a patient under his care, labouring under the most dreadful symptoms of confirmed hy- drophobia, in consequence of the bite of a mad dog upwards of three months hefore he was taken ill. Having tried the usual methods without success, Dr. Fayerman, to use his own ex- pression, “‘ took time to consider what was best to be done ; my pescne observations confirmed me in the previous idea which had entertained, that hydrophobia ts a disease specifically of the nervous system. I felt more strong in the belief, from the know- ledge that local irritation from wounds in irritable habits, espe- cially when conjoined with a perturbed state of the passions, and also violent, affections of the mind, independently of corporal in- jury in hysterical and hypochondriacal constitutions, have at times produced all the pathognomic symptoms of canine madness.” “« Having witnessed the powerful effects of lead on the nervous system, I determined at once to give this mineral a trial in the terrific disease before me.” “ At nine o’clock,”’ (the patient being in a state of comparative quiet, from exhaustion) “ I gave him 35 drops of the liquor plumbi superacetalis, vulgo Goulard’s extract of lead, on a lump of sugar ; the pulse at this period was tremulous and irregular, and at 105; the power of deglutition at this period was greatly impeded by the frequent spasms affecting the glottis, and it was at least 15 minutes before the medicated sugar had passed into the stomach. At 10 o’clock the dose was increased, and he took 40 drops of the extract of lead, in the same manner as before, pulse 98. He slept from half-past 10, to within a few minutes of 11. He was awoke by severe pain about the scrobiculus cordis, great thirst and heat about the fauces, but there was absence of 1824.] Scientific Notices— Miscellaneous. 233 spasmodic’ contraction which had previously threatened suifo- eation. Atoneo’clock, on the 13th of August, I repeated the venesection eight ounces, and gave 45 drops of the extract of Jead, mixed in a.small portion of honey. At three, this morn- ing, the dose was repeated, and notwithstanding the powerful astringency of the medicine, there was certainly less difficulty in the act of swallowing. The pain about the stomach had been reduced in violence, since the use of the lancet a second time, and the mind had become more calm and collected. At five o’clock the thirst having increased beyond endurance, he expressed a desire to drink; a little weak brandy and water, mixed in a tea-pot, was presented to his notice; but the mo- ment the fluid had been taken to the lips, a violent spasm came on, he seized the vessel with the fury of a maniac, and bit the spout off. In 25 minutes after this paroxysm had subsided, 50 drops of the solution of lead was administered. At nine o’clock the patient complained of coldness along the spine, and of a peculiar tingling sensation in the lower extremities, and soon after of total inability to move his limbs—the pulse at this time was at 84. I examined his legs and found them completely paralyzed. The symptoms of hydrophobia became every hour after this crisis materially lessened. I fully succeeded at half- past 10 in getting down three tablespoonfuls of castor oil. reduced the solution of lead in doses of 20 drops every three hours; at 12 o’clock the bowels were evacuated ; at two P.M. we again attempted the introduction of the weak brandy and water, the patient made a bold and resolute effort to conquer or die in the struggle. He armed his mind with the strongest courage and fortitude; he carried the vessel to his lips, and although his countenance fully displayed the most horrid re- pugnance, yet from a total absence of spasm, he succeeded in getting down a considerable portion of the fluid. From this moment I considered the cause gained, and I hailed with joy the triumph which such a conquest inspired. I gradually de- scended the scale of my remedy to 10 drops, and | had the satisfaction to find, that 2 the space of 48 hours from the first exhibition of the solution of lead in this case of hydrophobia, all the more urgent symptoms of this monstrous disease had abailed. In four days, not the feast appearance of hydrophobia malady existed, the patient had the look of a person enervated and debilitated to an excessive degree; the wound in the hand” (occasioned by excision of the bitten part, and the application of caustic,) “ was suffered to remain open for some weeks. On the 26th September, the patient recovered the use of his limbs and was discharged.” (Signed) ARNALL THOMAS FAYERMAN. We have extracted the preceding from the account which 234 Scientific Notices—Miscellaneous. [Sepr. appeared in the Morning Herald of the 7th of last month. It cannot be too generally known ; for if further experience prove the efficacy of the remedy, Dr. Fayerman’s name will stand deservedly high, as a benefactor of mankind. The subject is rather more exclusively medical, than we are in the habit of admitting amongst our miscel/anea, but our great object is to make the pages of the Annals of Philosophy, the medium for communicating interesting and useful matter in every depart- ment of science, to the world at large, whether that matter be original, or selected from respectable cotemporary journals, foreign or domestic, and other works of merit and reputation ; and we shall continue to pursue that object, equally indifferent to the worthless praises and contemptible criticisms of hebdo- madal quacks and sciolists. 7. Extraordinary Tide. About 10 p. m. on Tuesday, the 13th inst. wind ESE. light airs and variable ; barometer 30°0, thermometer 70, a sudden flux of the tide was observed at this port, which rose several feet, and in its reflux, aided by the ebb, its rapidity was such as to sweep every thing before it. The chain conductor of the flying bridge on the Lairy, gave way, and for a time rendered its bridge useless; but by the exertions of the men it was soon repaired. However, about one o’clock, it being then near low water, the same occurrence again took place, and the bridge was again torn from its position. Boats, timber, &c. were swept away by the great flux and reflux of the tide, which con- tinued at intervals until four o’clock on Wednesday morning (being about three-quarters flood), when it began to assume a more formidable and terrific appearance. The ordinary velo- city of the tide being not more than two knots per hour, was now observed to run from seven to eight, at intervals of from 13 to 15 minutes, and sometimes 20 minutes. As the time of high waterapproached, the flux and reflux was more powerful, and of longer duration, probably occasioned by the unfinished ends of the Breakwater being at that time overflowed. From nine till about twelve o’clock, the river of Catwater was impassable, excepting by taking advantage of going with the current, and the , same inreturning. Boats were torn off the shore, and in a few moments hurried out of sight. The appearance of the elements now was truly wonderful; distant claps of thunder, heavy low- ering clouds, some rising in different positions, and others floating in a horizontal direction, occasioned, no doubt, from the extraordinary variations of the wind blowing fresh in puffs from every quarter of the compass in a short space of time, with intervals of calm. Some idea of the extraordinary rapi- dity of the current may be imagined, when it is asserted, from the minutest observations, that the flux or fresh of the tide at 1824.] Scientific Notices— Miscellaneous. 235 times, was 2 feet 2 inches perpendicular in five minutes, and again actually made a reflux of 3 feet 6 inches in the same short space of time, tearing up the soil from the bottom of the river, the agitated thick surface of which resembled the boiling of a pot. The vessels at the Breakwater one minute were afloat, and the next lying high and dry on the body of the works ; and but for the great exertions of the workmen and crews, much damage must have been done. Indeed, was there a possibility of lifting that stupendous structure from its position only for an hour, not a ship could have been safe either in Plymouth harbour or in the Pool! and although it must appear strange, at the same time the sea in the offing was particularly smooth. About half- ast two, p. m. the tide began to resume its regular course. No doubt we shall soon hear of some extraordinary convulsion of nature in some part of the world. In 1798, a similar occurrence took place, about the time of the dreadful earthquake in Sienna, which swallowed up many thousands of our fellow creatures.— (Plymouth Journal.) 8. Unequal Distribution of Heat in the Prismatic Spectrum. That the different portions of the prismatic solar spectrum possess different heating powers, has been universally admitted by every philosopher who has examined the subject experiment- ally ; but a great diversity of opinion has prevailed respecting the precise point where this power resides in its greatest mten- sity. Landriani, one of the first who investigated this subject, placed the maximum heating power in the yellow rays, Rochon in the orange or orange yellow, and Senebier also in the yellow. Herschel, on the contrary, found the heating power of the red to be superior to that of all the other coloured rays; but that there is a certain point of the spectrum, situated immediately beyond the red and invisible, which elevates the thermometer still higher than any of the visible rays. His experiments were directly contradicted by Leslie, but were soon after in a great measure confirmed by Englefield. Dr. Seebeck, in a memoir read to the Royal Academy of Sciences in Berlin, which with numerous ori- ginal experiments combines a copious discussion of the opinions of preceding inquirers, appears to have ascertained the cause of those anomalous statements. It exists im the particular nature of the medium by which the rays of light are decomposed ; a circumstance so little regarded that few experimenters have even deemed it necessary to record the material of their prism. The following is a summary of his results. In every part of the prismatic spectrum, there is a percepti- ble elevation of temperature, and this is uniformly least in the outermost edge of the violet. From the violet it gradually increases, as we proceed through the blue and green, into the yellow and red. In some prisms, it attains a maximum in the yel- 236 Scientific Notices— Miscellaneous. [Sepr. low, as, for example, in those filled with water, alcohol, or oil of turpentine. In others, as in those filled with a transparent solu- tion of sal ammoniac and corrosive sublimate, it attains a maxi- mum in the orange. Prisms of crown glass and of common white glass have the maximum of temperature in the centre of the red; others, which appeared to contain lead, have the maxi- mum in the limit ofthe red. Prisms of flint glass have the maximum beyond the red. In all prisms, without exception, the temperature regularly diminishes from beyond the red; but it still continues perceptible at a distance of several inches from the extremest limit of that side of the visible spectrum. (Schweigger’s Nenes Journal, vol. x. p. 129.) 9. Distinction of Positive and Negative Electricity. Positive and negative electricity may be readily distinguished by the taste, on making the electric current pass by means of a point on to the tongue. The taste of the positive electricity is acid; that of the negative electricity is more caustic, and, as it were, alkaline. Berzedius.—(Journal of Science.) 10. Description of two Surfaces composed of Siliceous Filaments incapable of reflecting Light, &c. The surface was produced by the fracture of a large quartz crystal, two inches and a quarter in diameter, of a light smoky colour, but impervious to the light, except in small pieces. The surface of the fracture is absolutely black, and was at first supposed to have been occasioned by the interposition of a thin film of opaque and minutely divided matter that had insinuated itself into a fissure of the crystal; but this opimion was over- turned when Dr. Brewster observed that both surfaces were equally and uniformly black. He therefore suspected the phe- nomenon to be occasioned by the surfaces being composed of short and slender filaments of quartz, of such exceedingly mi- nute diameter, as to be incapable of reflecting a single ray of the strongest light; and he verified his conjecture by plunging the fragment in oil of anniseeds, which approaches to quartz in its refractive powers, and examining the light reflected at the sepa- rating surfaces of the oil and the quartz. The blackness dis- appeared ; and the fragment, whether seen by reflected or trans- mitted light, comported itself like any other piece of quartz of the same translucency. On removing the oil from the surface it assumed its original blackness. Dr. Brewster calculates the diameter of the fibres to be about sostsosth of aninch, or one-fourth of the thickness of the aqueous film of a soap bubble previous to its bursting.—(Edin Jour. of Science.) > 1824:] New Scientific Books. 237 ArTICLE XVI. NEW SCIENTIFIC BOOKS. PREPARING FOR PUBLICATION, In a few days will be published ‘‘ Commentaries on the Diseases of the Stomach and Bowels of Children;”’? by Robley Dunglison, MD. &c. &c. The papers printed in the Transactions of the Royal Society during the last three years, detailing the Discoveries of the Functions of the Nerves, will be immediately republished with Notes, and a general Introductory View of the Nervous System; by Mr. Charles Bell, Pro- fessor of Anatomy and Surgery to the Royal College of Surgeons, and Surgeon to the Middlesex Hospital. The Topography ofall the known Vineyards; containing a Descrip- tion of the Kind and Quality of their Products, and a Classification, From the French. 12mo. The Travels of General Baron Minutoli in Lybia and Upper Egypt ; in 8vo. Columbia: its present State of Climate, Soil, Productions, Popula- tion, Government, Commerce, &c. &c.; by Col. Francis Hall, Hydro- grapher in the Service of Columbia. S8vo. A Practical System of Algebra for the Use of Schools and Private Students ; by Peter Nicholson and J. Rowbotham. Illustrations of Conchology, according to the System of Lamarck, in a Series of Engravings ; by E. A. Crouch. The Century of Inventions of the Marquis of Worcester, from the original MSS. with Historical and Explanatory Notes, and a Biogra- phical Memoir; by Charles F. Partington, of the London Institution. The Brewer’s Director; a Chemical, Experimental, and Practical Essay; by a London Brewer. JUST PUBLISHED. Historia Itievallensis, containing a Dissertation on the Animal Remains lately found in the Cave at Kirkdale, with original Thoughts on the Geological Evidence of it, &c. &c. With Plates, from Draw- ings by J. Jackson, RA. 13s. Boards. Principles of the Kantesian or Transcendental Philosophy. By T, Wirgman. 8vo. 6s. Observations on the Rebuilding of London Bridge. By J. Seaward. 7 Plates. 8vo. 12s. fron Bridges of Suspension now erecting over the Strait of the Menai, at Bangor, and over the Conway. By J. G. Cumming. 5s. sewed. Bland’s Elements of Hydrostatics. Crown 8vo. 7s. Shute’s Principles of Medical Science and Practice. PartI. 8vo. 18s. Herculanensium Voluminum, Pars Prima. Royal 8vo. 11. 5s. 6d. Hirnschadel’s Encephalology. 12mo, 5s. 938 New Patents. [Szpr. ArtTIcLeE XVII. NEW PATENTS J. Gibson, woollen-draper and hatter, Glasgow, for manufacturing an elastic fabric from whalebone, hemp, and other materials combined, suitable for making into elastic frames, or bodies, for hats, caps, and bonnets, and for other purposes.—June 15. W. Bally, the younger, Lane End Staffordshire Potteries, for his improved gas consumer, for the more effectually consuming the smoke arising from gas burners or lamps.—June 15. J. Hobbins, Walsall, Staffordshire, ironmonger, for his improvements in gas apparatus.—June 22. H. Austin, Alderley Mills, Gloucestershire, manufacturer, for cer- tain improvements on shearing machines.—June 22. J. B. Higgon, Gravel-lane, Hounsditch, for his improvement in carv- ing-knives and other edged tools.—June 22. W. Busk, Broad-street, merchant, for certain improvements in the means of propelling ships, boats, or other floating bodies.—June 29. W. Pontifex, the younger, Shoe-lane, coppersmith and engineer, for his improved modes of adjusting or equalizing the pressure of fluids or liquids in pipes or tubes, and also an improved mode of measuring the said fluids or liquids.—July 1. J. L. Bradbury, Manchester, Lancashire, for his mode of twisting, spinning, or throwing silk, cotton, wool, linen, or other threads or fibrous substances.—July 3. P. Taylor, City-road, engineer, for certain improvements on steam- engines.—July 3. J. L. Higgins, Oxford-street, for certain improvements in the con- struction of the masts, yards, sails, and rigging of ships and smaller vessels, and in the tackle used for working or navigating the same. —July 7. W. Hirst and J. Wood, both of Leeds. manufacturers, for certain improvements in machinery for raising or dressing of cloth.—July 7. J.C. Daniell, Stoke, Wiltshire, clothier, for his improved method of weaving woollen cloth.—July 7. C. Phillips, Repnor, Kent, for certain improvements on tillers and steering wheels of vessels of various denominations.—July 13. C. R. Baron de Berenge, Target Cottage, Kentish Town, for cer- tain improvements in the method of applying percussion to the purpose of igniting charges in fire-arms generally, and in a novel manner, whereby a reduction of the present high price of fire-arms can be effected, and the priming is also effectually protected against rain or other moisture.—July 27. A. Nesbitt, Upper Thames-street, broker, for a process by which certain materials may be manufactured into paper or felt, which mate- rial is applicable to various useful purposes.—July 27. T. Wolrich Stansfeld, Leeds, merchant, for certain improvements in power looms, and the preparation of warps for the same.—July 27. E. Cartwright, Brewer-street, Golden-square, engraver and printer, for improvements to roller printing presses.—July 27. at ae 1824.) ‘Mr. Howard’s Meteorological Journal. 239 ArticLteE XVIII. METEOROLOGICAL TABLE. = fi BARoMETER, THERMOMETER, 1824, Wind. Max. Min. Max. Min. Evap. | Rain. 7th Mon. July 1/8 Wj 29°95 29:70 73 55 —_ 10 2'S WwW) 29°72 29:70 76 46 aes 05 3IN W 29°84 29-72 72 54 — 26 4\IN W} 30:08 29°84 66 46 — 02 5N W| 30:08 29:98 (22 54 — 09 6| £E 20:98 29:98 66 56 — 02 7| W 30°10 20°98 70 56 — 04 8| W 30°10 30°05 77 61 — 9S WI 30:05 29:98 82 55 OO) fee 10.N W! 30°17 50°05 75 AQ — 11) W 30°17 30°17 80 55 — 13S W! 3015 30°08 84 53 == 1i3IN WI! 30:08 30°01 88 56 poe 14 Var. | 30°01 29°95 85 59 — 63 15S W| 3018 29°97 vies 55 05 16N WI 30°32 30°18. re | 55 == 02 ize N 30°34 30°32 77 53 _— 18| N°} 30°51 30°34 74 49 == 19S W > 3051 30°46 75 49 — 20, N 30°46 30°33 74 51 = 21) N 30°34 30°33 vs 54 ‘78 22; E 30°33 30°29 78 50 = 93| S 30°29 30°03 82 54 — 24\N E| 30:03 29°94. 78 52 — 25IN W| 29:97 29:97 77 54 — 26, E 30°12 29°97 73 52 — 30 27,N. EE) 30°37 30:12 68 44 — 2SN E| 30°37 30°21 78 42 05 29, E 30°21 29°84 78 AA — 30,N E! 29°84 29°70 75 AA — “| E 29°82 29:76 76 56 10) 15 | 3051 | 2970 | 8s | 42 | 398 | 1°68 The observations in each line of the table apply to a period of twenty-four hours, beginning at 9 A. M. on the day indicated in the first column. A dash denotes that the result is included in the next following observation, 240 Mr. Howard's Meteorological Journal. [Suvr, 1824. REMARKS. Seventh Month—1. Fine. 2—4. Showery. 5. Fine. 6, Cloudy, with showers. 1. Showery. 8, 9. Cloudy and fine. 10—{2. Fine, 13. Fine: sultry. 14. Sultry : some thunder atintervals, with large drops of rain, during the day.. About nine, a tremendous storm of thunder, lightning, and heavy rain: the lightning extremely vivid, and almost continuous from the NW to the SE by the S: the thunder abated between eleven and twelve; but the lightning was visible for several hours ‘after: 15. Cloudy and fine. 16—22. Fine. 23. Sultry. 24, 25. Fine. 26. Cloudy: showery. 2T, Cloudy. 25—30. Fine. 31. Cloudy: showers. RESULTS. Winds: N,4; NE, 4; E,5; S,1; SW,6; W,3; NW,7; Var. I. Barometer: Mean height Tor the month. ..... ele sede woiae cc cid erders ble cas bin sieie DO ORCUEIENER, For 13 days, ending the Ist (moon north). .......... 29-810 For 14 days, ending the 15th (moon south), ....... .. 30-006 For !3 days, ending the 28th (moon north)...... eee. 30'248 Thermometer: Mean height For the month, ......seeccsessscscccccccssserces -. 64°435° For the lunar period. ..... He ae coecnrccccccncocess G0 166 For 31 days, the sun in Cancer.......+.--ese0--+-- 63°322 Evaporation. v..-2csccccccccccccececccccsoecscctessesverssssecs SOS IN, Bain, goctidshakannkbdane paudeineislssnminiswiseieenieclets's Seltuwishie-ets cickiee MT Ce Laboratory, Stratford, Eighth Month, 23, 1824, R. HOWARD. ANNALS OF PHILOSOPHY. OCTOBER, 1824. ARTICLE I. Ona new Mineral Substance. By Mr. A. Lévy, MA. of the University of Paris. (To the Editors of the Annals of Philosophy.) “ GENTLEMEN, Newman-street, Oxford-street, Sept. \7, 1814. Mr. Hevuianp had put aside a long time since a specimen of Mr. Turner’s collection, from the Bank mines, in the government of Ecatherineburgh, in Siberia, considering the small emerald green transparent crystals which are upon it as differing from any described substance. Upon detaching and measuring some of them, I have ascertained that their form was incompatible with those of the arseniates and green carbonate of copper, with which their external characters bear some resemblance, and I am led, therefore, to consider them as belonging to a new mineral species, to which Mr, Heuland proposes to give the name of Brochantite, in honour of a mineralogist as well known here as in his own country. The appearance of the crystals is that of thin rectangular tables, bevelled on the edges with the angles truncated, such as is represented by fig. 7 (Pl. XXXII). Their colours are emerald green, they are transparent, and their hardness is about the same as that of green carbonate of copper. The planes M are blackish and dull; all the others are brilliant and fit for measure- ment by the reflective goniometer. I have not been able on the very minute crystals I have examined to ascertain the directions of the planes of cleavage, and { have, therefore, assumed as the primitive aright rhombic prism, fig. 6, the lateral planes of which correspond, i believe, with the planes marked M, fig.7. The planes ¢' and a' are then the results, the first ofa decrement by four rows on the angles e of the base of the primitive; the other of a decrement by one row on the angle a. The angles I have New Series, vou. viii. R 242 Mr. Lévy on a new Mineral Substance. [Ocr. measured are the incidences of e* and a! on the base, and it is from these data, and from the supposition that 4 and 1 are the indices of these planes, that the angles and dimensions of the primitive arededuced. I have thus found that the lateral planes of the primitive were inclined to each other at an angle of 114° 20’, and that the height was to one side of the base nearly in the ratio of 25 to 12. The other angles are (a’, p) = 104° 75’, (e* p) = 148° 30’. lt may appear strange that in the want of sufficient data to determine the primitive form, and being obliged to make a sup- position upon the laws of decrements which produce the faces e* and a', I have not chosen the simpler hypothesis of each of these faces being the result of a decrement by one row. In that case the lateral planes of the primitive would have been inclined at an angle of 162° 18’, and had I supposed 2 instead of 4 for the index of the face e*, the incidence of the lateral planes would have been 145° 25’. Now though I could not measure the angle of the planes M, fig. 7, their incidence appeared to me much nearer to the angle 114° 20’, which I have chosen, than any of the other two very obtuse angles; this circumstance added to some indications of cleavage in the direction of the same planes, determined me to adopt the number 4. The crystals are placed upon mamillated green carbonate of copper lying upon massive red copper. Upon a specimen of wavellite, from Cornwall, belonging to the same collection, I have observed some minute white trans- parent crystals in the form of acute rhombic octahedrons, with their summits replaced by a plane, see fig. 8. This form is not incompatible with wavellite, whose primitive form is a right rhombic prism. However, in trying to split some of the crys- tals, I could not perceive any indication of the cleavages which exist in wavellite. The only means to ascertain whether their form could be derived from that of wavellite was in the follow- ing manner. First, it is obvious that, in that case, one of the parallelograms ABCD, A BCE, BEDF, must be parallel to the base of the primitive of wavellite. Secondly, one of them must be similar to that base, or at least must be such that when placed in the plane of that base so that its diagonals be parallel to the diagonals of the base, the sides must be found parallel to lines drawn from one of the angles of the base to some simple multiple or part of the opposite sides. If none of these condi- tions be satisfied, then it may be safely inferred that thé two forms are incompatible. But the application of this method supposes that the incidences of the faces of the crystals can be measured with great accuracy, and here the planes were not sufficiently brilliant to answer in the measurements of less than half a degree. Dr. Wollaston kindly undertook an examination of this substance, and the results of his: observations were as — a. ee 1824.] Examination of Brochantite by the Blowpipe. 248 follow. His experiments were performed upon two or three small crystals, the largest of which weighed about 1-80th part of a grain. The only substances he could detect in them are alumina and fluoric acid. He also measured the refractive power comparatively with that of wavellite, and found the index of refraction to be 1°47, whilst that of wavellite is 1°52. Heis, therefore, of opinion that these crystals belong to a distinct species, for which he proposes the name of fluedlite. He also measured the crystals, and found (b, 6’) = 144° (6, 6”) = 109° (6, 6b) = 82. Hence the primitive form may be assumed to be a right rhombic prism, the lateral planes of which are inclined to each other at about 105°. I shall conclude this short paper by mentioning, that upon a specimen from Mendip, near Churchill, Somersetshire, I have found a white laminary substance which cleaves with great faci- lity, and brilliant surfaces parallel to the lateral planes and shorter diagonal of a rhombic prism of 102° 25’, and thus differs from sulphate of lead to which it bears a great resemblance, and is very likely the substance, from the same locality analyzed by Berzelius, a notice of which was inserted in the number of the Annals of Philosophy for August last. I could find no cleavage in the direction of the base. —_——- Examination of the preceding Mineral by the Blowpipe, &c. At Mr. Lévy’s request, I have examined the Brochantite by the blowpipe, but the quantity which he could supply me with was so very small, not exceeding two-tenths of a grain in all, that I have been unable to obtain satisfactory information as to the true composition of the mineral. The results, however, such as they are, I lay before our readers. A minute crystal, not half the size of the smallest pin’s head, heated alone on charcoal, immediately lost its fine green colour, and became dark brown, slightly inclining to areddish hue, but did not fuse. The heated particle was not attracted by the magnet. Another particle cemented to the end of a fine platina wire by alumina, in the manner recommended by Mr. Smithson, fused readily, and alloyed with the platina. With soda on the platina wire, and in the vxidating flame, the assay gave a brown opaque globule, which was not perceptibly altered in the reducing flame. With boraz, in the oxidating flame, the assay gave a transpa- rent, very deep green glass. When the flux was not in large proportion to the assay, the globule appeared black, from the intensity of the colour. In the interior flame the green colour R 2 244° Examination of Brochantite by the Blowpipe. [Oct quickly disappeared, and the globule became red from reduced copper. With salt of phosphorus, the same as with borax, except that the green colour was not so intense, The quantity being so minute, I could not expect to detect the presence of arsenic by its odour. I, therefore, sought for arsenic acid by treating a few minute fragments of the crystals on a slip of glass, with potash and nitric acid, &c. but no indica- tion of its presence was afforded by nitrate of silver. With nitrate of lead, the solution gave a considerable precipitate, inso- luble, when largely diluted, in excess of nitric acid. The crystals dissolved completely in muriatic acid without the slightest effervescence, and the solution, diluted with a large quantity of water, gave a white precipitate with muriate of barytes, apparently perfectly insoluble in excess of acid. To ascertain, however, if phosphoric acid be present, I digested the precipitate by muriate of barytes in diluted muriatic acid with heat, decanted the clear fluid, and added ammonia, but not the least cloudiness, indicative of a phosphate, ensued. ‘To be still more certain, I tried the converse of Dr. Wollaston’s beautiful and delicate process for detecting the minutest portion of mag- nesia ; that is, I dissolved a portion of the crystals in nitric acid, and to the clear solution added a solution of nitrate of magnesia, and to the mixture an excess of bicarbonate of ammonia. Letters were then described with a giass rod in the solution on the slip of glass, and the mixture slightly warmed over the lamp, Lut no traces whatever were discernibie on the glass. A com- parative experiment made with a similar particle of phosphate of copper gave distinct and strong lines on the first impression of the heat. As from the experiment with muriate of barytes, a sulphate appears to be present, a portion of the crystals was heated in pure water, and the liquid tested with muriate of barytes, but no precipitate ensued; the water did not appear to have dissolved any thing; the appearance of the crystals was wholly unaltered. I could not detect any trace of lime, magnesia, manganese, or iron, in the crystals, nor any decisive indications ofalumina or silica; in short, nothing but copper and sulphuric acid; and yet they appear to be wholly insoluble in water. A particle of a crystal laid in a drop of water on a clean polished bar of iron, and the water evaporated to dryness left no trace of copper, nor any more mark than another drop of the same water evaporated to dryness beside it. Prussiate of potash indicated nothing in the solutions but copper. From the insolubility of the crystals in pure water, and their fine green colour, it can hardly be doubted that they must con- tain something else besides sulphuric acid and oxide of copper ; 1824.] On the Heat produced by firing Gunpowder, &c. 245 but what the ingredients may be that have escaped detection, I must leave to future experiments, if hereafter I may obtain a larger supply of the crystals, to determine. J..G..€- P.S. From some very indecisive appearances that occurred in the examination of the globule with salt of phosphorus, I am inclined to think that alumina or silica, or both, may be consti- tuent parts of the crystals; but I have no means of confirming or disproving the conjecture. ArTIc.eE II. On the Heat produced by jiring Gunpowder, and on the intense Heat of Blast-furnaces. By W.T. Haycraft, Esq.* Tur following explanations on these subjects are suggested by Mr. Haycraft, towards the conclusion of his paper on the “ Specific Heat of Gases.” The increased capacity of air, when under lesser degrees of atmospheric pressure, has been properly: made use of to explain the extreme cold which exists in high regions ; and its decreased capacity under mechanical pressure also satisfactorily accounts for the heat evolved under that condition. This principle, so far as I know, has not been used to explain one cause of the intense heat produced during the combustion of gunpowder and other explosive mixtures. If we reflect a moment, however, we shall perceive that the resistance of the pressure of the atmo- sphere to the expansion of the nascent gases produced by the combustion, will cause them to exist in a state of greater den- sity than when the resistance of the atmosphere has been finally overcome. It is during this state of potential compression, if I may use the term, that the intense heat is produced. After the first explosion, however, the gaseous products will expand, and then there will necessarily be absorption of caloric, and conse- quently comparative coldness produced. In order to ascertain whether there is a permanent evolution of caloric, occasioned by the combustion of gunpowder, [ made the following experiment. Having a receiver containing 528 cubic inches, filled with water of a temperature of 52°, placed in a pneumatic trough, the surrounding atmosphere being also 52°, I introduced 240 inches of the aeriform fluids, produced during the combustion of that composition of gunpowder which is used for pyrotechnical purposes. After the explosion, the gas in the upper part of the receiver had acquired a temperature of nearly 54°, and the water not so much. This experiment shows that though heat is * From the Transactions of the Royal Society of Edinburgh. 246 On the Heat produced by firing Gunpowder, &c. [Ocr. evolved in the combustion of gunpowder, its quantity is not nearly so great as has been imagined. Again, if we consider that the products of the combustion of gunpowder have not, by direct experiment, been proved to have a greater specific heat than the ingredients of that composition, the phenomenon of heat being produced during that combustion should not be urged » as an objection to the hypothesis of Black and Crawford. Indeed, it appears very probable, from the inspection of the Table of Specific Heats of Different Bodies, that those elastic products have a less capacity than the ingredients of gunpowder from which they are produced. For example, azote, which composes two-thirds of the elastic products, has a capacity of 2669, and carbonic acid, comprising one-third of the products, if my experiments are to be trusted to, has a capacity of only 1751, water being 10000. Nitric acid, of a specific gravity of 1354, has a capacity of 5760. The azote, therefore, and oxygen, which is produced from the decomposition of one of the ingre- dients forming the elastic products of not half the specific heat of that ingredient, should, according to the hypothesis of Black, evolve heat. This might take place even if we make allowance for the lesser capacity which nitric acid has in its state of one of the ingredients of the nitrate of potash. The same condition of potential compression may also contri- bute to the intense heat which takes place in a blast-furnace. This heat is known by all conversant with the phenomenon to be, not in a ratio of the fuel consumed, but of some compound ratio, This may be explained in the following manner: 1. A quantity of air is forced into contact with the coals in a state of ignition, and its temperature is suddenly raised extremely high. 2. In this condition, were it not for the pressure of the atmosphere, it would become as suddenly expanded. 3. Had this expansion taken place, it would have acquired an increased capacity, and would consequently have absorbed a considerable portion of the caloric evolved by the combustion, tending thereby to lessen the capacity of the heat. 4. But the heated air being prevented by the pressure of the atmosphere from expanding in a ratio equal to the temperature acquired, the absorption of caloric is lessened, and a greater proportion of the heat of combustion is rendered free. Thus, although the total quantity of caloric evolved at, and consequently to combustion, may be in a direct ratio of the quantity of fuel consumed; yet the intensity of the thermome- trical heat at the moment, and at the place of combustion, will be greater in a compound ratio, directly as the pressure of the atmosphere, and inversely as the times of expansion of the air employed in the blast. These times are, of course, inversely as the intensity of the blast. The thermometrical heat then, at the moment and place of combustion, will be ina compound ratio of the quantities of fuel consumed, the weight of the atmosphere, 1824.] Dr. Thomson on Subphosphuretted Hydrogen Gas. 247 and the quantity of air employed in the blast in a given time. The same rule will hold even in what are called chimney fur- naces; and it is ascertained by experience, that those furnaces of steam-engines through which a greater quantity of air passes in a given time, consume a proportionally less quantity of fuel to produce the same effect. Probably blast-furnaces might be advantageously employed in lessening the quantity of fuel used for those valuable machines. Although, according to the foregoing experiment, it appears contrary to my original expectation, that, by volume, oxygen gas has the same specific heat as carbonic acid, it by no means follows that caloric should not be evolved during the formation of the latter by combustion. This formation does not consist of a conversion of oxygen into carbonic acid, but of a union of two ingredients into a compound, having an absolute capacity for caloric equal to one of the ingredients only, namely, the oxygen gas; consequently the whole absolute heat of the carbon is ren- dered free. Articte III. On Subphosphuretted Hydrogen Gas. By Dr. Thomson, FRS. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Glasgow, Sept. 9, 1824. In the account of subphosphuretted hydrogen gas, inserted in the last number of the Annals, I observe a mistake into which I had fallen while hastily transcribing the account from my common-place book. I have misstated the specific gravity of hydrogen gas. The statement in page 205 of the last number should have been as follows : “ Subphosphuretted hydrogen gas is composed of 1 volume hydrogen gas............ 0°0694 0°75 volume phosphorus vapour. .... 0°6250 oe 0°6944 So that its specific gravity is reduced from 0:9027 to 06944, and it contains just nine times as much phosphorus as hydrogen. It may be reckoned a compound of 4 atoms hydrogen and 3 atoms phosphorus,” Your noticing this error in your next number will much oblige, Gentlemen, yours truly, THomAs THOMSON. 248 Corrections in Right Ascension of [Ocr. | ArticLte IV. Corrections in Right Ascension of 87 Stars of the Greenwich Catalogue. By James South, FRS. y Pegasi| Polaris | Arietis| « Ceti |Aldebaran| Capella | Rigel @ Tauri |x Orionis Mean ARQ|!- ™. §- b.m.s. |ivm. s. |h.m.s. jh.m. s. jhe m. s. |l.m. s. them. s. |h. m. s. ~ 1824, Yo 4 11'17| 0 58 2°46 |1 57 16-42|2 53 5-44 [4 25 50°01)5 3 42°21) 56 6 5-11 [5 15 10429 45 33-93 + 56:99" + 4°90") 4 4:43/"|4 4°45” + 5:54"| + 3°64” + 4°64"| + 3-83” 62 | 57-16 92 Ad 48 58 67 67 86 3) 63) 5T-27 93 41 | 50 62 69 70 89 4) 63 | 57°38 95 49 53 66 72 73 92 5| «63. | 57-48 96 5) 36 70 75 17 95 6| 64 | 57-59 98 53 58 74 11 80 98 "| 64 | 57-70 99 55 61 18 80 83 | 4-01 s| 64| 57-74 | 5:00 51 64 8! 83 86 04 9] 64] 57-78 02 59 66 85 85 89 OT 10} = 64. | 5782 03 60 69 88 88 92 69 11] 64.| 57-86 o4 62 7 92 90 95 12 12} 64] 57-90 05 63 14 95 93 98 15 13} 64. | 57-88 06 65 16 98 95 | 5:02 18 14] 63 | 57-85 08 66 79 | 6-02 98 05 20 15] 63 | 57°83 09 68 82 05 | 4:00 08 23 16] 63 | 57:80 10 69 85 09 03 11 26 17} +63 | 57°78 12 7 87 12 06 14 29 18} 63| 57-71 13 72 89 16 08 17 32 19} 63 | 57-64 13 74 91 20 il 20 34 20| 63| 57°57 14 75 94 24 13 23 37 21} 62] 57°50 15 7 96 28 16 26 40 99} 62] 57-43 16 78 98 32 18 29 43 93} 62) 57-25 17 79 | 5:01 36 20 32 45 24| 62| 57-08 17 8] 03 40 23 36 AS 25| 61 | 56-90 18 82 05 4A 25 39 50 26, 61| 56-73 18 83 08 48 Q1 42 53 91} 61 | 56°55 19 85 10 52 30 AD5 56 98| 61| 56:34 20 86 12 55 32 48 59 99} 60| 5613 20 87 14 58 34 50 61 30| 59 | 55-92 21 &8 16 61 37 53 63 31, 59 | 5571 22 89 18 65 39 56 66 Nov. 58 | 55:50 22 90 20 68 Al 59 68 58 | 55-22 23 91 22 71 43 61 71 57 | 54-94 24 92 24 14 AS 64 13 57 | 54-67 25 93 26 78 48 66 76 56 | 54:39 25 94 28 8] 50 69 79 56 | 54-11 26 95 30 84 52 72 82 55 | 53-79 26 96 32 87 54 14 84 54| 53-46 27 97 34 90 56 11 87 54.| 53:14 21 98 35 93 58 79 89 53 | 52°81 28 99 37 96 60 81 92 52 | 52-49 28 | 5-00 39 99 62 84 94 51 | 52:10 28 01 41 | 701 65 86 97 50 | 51-71 28 01 AQ 04 67 89 99 50 | 51-32 29 02 4A 07 69 91| 5-02 49 | 50-93 29 03 46 10 1 94 04 48 | 50:34 30 04 48 13 2 96 OT 47 | 5011 30 04 BO 15 15 98 09 46 | 49°68 30 05 5 18 76 | 6-00 il 45 | 49-24 30 05 53 20 78 02 13 44| 48:81 30 06 BA 23 80 04 15 43 | 48-38 30 06 56 25 81 06 17 42 | 47-89 30 07 BT 28 83 08 20 42 | 47-40 30 07 59 30 85 11 22 41 | 46-92 30 0s 60 33 87 13 24 40 | 46°43 3 08 62 35 88 15 26 39 | 45-94 30 09 64 38 90 17 2s 38 | 45-41 30 09 6! 40 91 19 30 31 | 44-88 29 09 66 Al 92 20 31 36 | 44°36 29 09 67 43 93 22 33 35 | 43°83 28 09 68 A5 95 23 35 1824.] Thirty-Seven Principal Stars. 249 Sirius | Castor Procyon | Pollux | Hydre} Regulus | g Leonis | Virginis |SpicaVirz. Mean AR) h.m.s. |i.m.s. |h.m. s. him. s. |h.m. s. [h.m. s. [hom s. |hom. s. {hem so 1824. § |6 87 23°49)7 23 21°46] 7 30 5°32 7 34 3218/9 18 56°44/9 58 5957/11 40 4°73]11 41 31°86]13 1556-07 Oct. 1) + 2°92") + 3°95") 4 3° al + 3°74") + 2:44" 4+ 2°59" 4 217") 4 9-95" 4 2-01" 2 95 99 TT 46 61 18 27 21 3 98 4:02 ip Sl A9 63 19 28 21 A) 3-01 06 28 84 51 65 20 29 21 5 04 09 30 87 53 67 22 30 22 6 OT 13 33 91 56 69 23 $1 22 7 10 16 36 94 58 val 24 32 22 8 13 20 39 97 H 14 26 34 23 9 15 23 AQ 4:0) 63 76 Q7 35 24 10 17 27 A5 04 66 19 29 37 24 1] 20 30 48 07 68 81 30 38 25 12 23 34 51 10 7 84 32 AO 26 13 26 37 54 14 13 86 34 42 27 14 29 4] 57 17 16 89 35 43 28 15 sl 45 60 20 78 9] 3ST A5 28 16 34 A8 63 24 Sl 94 38 46 29 17 37 52 66 all 83 95 40 48 30 i8 40 56 69 31 86 99 AQ 50 3l 19 43 59 72 34 89 3'01 Ad 52 32 20 46 63 (8) 38 91 04 46 54 33 21 49 66 78 Al 94 OT 48 56 34 ad 52 70 81 A5 97 10 50 58 35 23 55 T4 84 48 3-00 12 51 60 36 24 58 17 87 52 02 15 53 61 37 25 61 81 90 55 05 18 55 63 38 26 64 84 93 59 08 20 57 65 39 27 67 88 96 62 11 23 59 67 Al 28 70 91 99 65 14 26 61 69 42 29 72 95 4-02 €9 17 29 64 ie At 30 15 98 05 12 20 32 66 7A 45 31 18 5-02 08 75 23 35 68 76 AT Noy. 1 81 05 10 719 26 38 71 18 A8 2 3 09 13 82 29 Al 13 81 50 3 86 12 16 86 32 A4 76 83 51 A 89 16 19 89 35 AT 78 85 53 5 91 19 22 92 38 50 81 88 54 6 94 23 On 96 Al 53 83 90 56 im 97 97 28 99 A4 56 86 93 58 8 99 30 31 5:03 AT 59 88 95 60 9) 4.02 34 34 06 50 62 91 98 62 10 05 ST) 37 10 53 65 94 3-01 64 ll 08 Al 40 13 56 69 97 02 66 12 ll AA A3 16 59 12 99 04 68 13 13 48 A6 20 63 75 3-02 09 10 14 16 51 AY 23 66 78 04 12 12 15 18 55 52 27 69 81 OT 14 7A 16 21 58 53 30 72 8&4 10 17 76 VW 23 61 58 33 Le 87 13 20 78 18 26 65 61 36 78 91 16 23 sl 19 28 68 64 AO 82 94 19 26 83 20 31 val 67 43 85 97 22 29 85 21 33 14 70 AG 88 AOL 24 32 88 22 35 78 43 AY 9] 04 27 35 90 23 38 81 16 52 94 08 30 38 93 24 40 85 19 56 97 lI 33 4) 95 25 43 $8 $2 59 AOL 15 36 44 98 26 45 91 85 62 04 18 39 AT 3:00 21 47 94 87 65 07 21 AQ 50 03 28 49 97 90 68 10 24 A5 53 06 29 51 6-00 92 val 13 Q7 48 56 08 30 53 03 95 ve} 16 31 51 59 11 250 Corrections in Right Ascension of (Ocr Arcturus |2a* Libre|a€or.Bor.|zSerpent.| Antares |wHerculis|jaOphiuchi} a Lyre |y Aquile h. m. s. fh. m, Ss. /h, m. s- 17 26 46°24} 18 30 58-99] 19 37 53°68 Mean AR} |b. m. s. {h. m. 5s. h.m. s. [he m. s. jh. m. s. |h. m. S. 1824, § [14 7 38°33)14 41 9°63)15 27 14-45]15 39 86°47/16 1827°91]17 6 37°72 + 2-68" 4 2-19" 4 3:46” 66 17 44 Oct. 1] 4 1°85") +.2°55!| + 1°80") + 2°38 + 3-354 2°53" 2 84 54 79 37 34 51 3 84 53 V7 36 32 50 64 14 A2 4 83 53 76 35 31 AS 63 12 Al 5 83 52 15 3 30 46 61 09 39 6 §3 52 73 32 28 A5 60 O07 37 7 82 51 72 31 27 A3 58 04 36 8 82 51 71 30 26 AQ 56 02 34 9 82 50 70 30 25 AO 55 1:99 33 10 82 50 69 29 24 39 53 97 31 1] 82 50 68° 28 23 37 52 95 30 12 82 50 67 27 21 36 50 92 28 13 82 49 66 27 20 34 49 90 26 14 82 49 65 26 19 33 AT 87 25 15 82 A9 64 25 18 31 A6 85 23 16 8Z AS 63 25 17 30 Ad 82 22 7 82 48 62 24 16 28 42 80 20 18 82 48 61 24 15 20 Al 78 18 19 83 48 61 23 15 26 AO 75 16 20 83 A8 60 23 14 25 39 13 15 21 84 48 60 22 14 23 37 11 13 22 84 48 59 22 13 22 36 69 Il 23 84 48 59 22 13 21 35 66 09 24 85 50 58 21 12 20 34 64 OT 25 85 50 58 21 12 18 32 62 05 26 86 50 58 21 il 17 31 59 04 27 86 50 57 20 10 16 30 57 02 28 87 51 57 20 10 15 29 55 OL 29 88 52 57 20 10 14 28 53 2°99 30 88 52 57 20 10 14 27 51 98 31 89 a 57 20 09 13 26 49 96 Noy, ] 90 54 57 20 09 12 25 48 95 2 91 55 57 20 09 11 24 46 93 3 91 56 57 20 09 10 23 Ad 92 4 92 57 57 20 09 10 22 42 90 5 93 58 57 20 08 09 21 40 89 6 94 59 57 20 08 08 20 38 87 | 7 95 60 58 21 c8 08s 20 36 86 | 8 97 61 58 21 08 07 19 35 85 | 9 98 63 59 22 09 07 19 33 84 | 10 99 64 59 22 09 O07 19 32 82 1}} 9201 65 60 23 09 07 18 30 81 12 02 67 60 23 09 06 18 28 80 13 04 68 61 24 10 06 18 26 19 14 05 69 61 24 10 06 17 24 78 15 OT 70 61 25 10 06 17 23 16 16 08 12 62 26 11 05 16 21 75 17 10 74 63 27 12 05 16 20 74 18 12 75 64 28 13 05 16 19 13 19 14 es 65 29 13 05 16 17 72 20 16 79 66 31 14 05 16 16 71 21 18 81 67 32 15 05 16 15 70 22 20 82 68 33 16 05 16 14 69 23 22 84 69 34 17 06 16 13 68 24 24 86 70 35 17 06 16 12 67 25 26 87 val 36 18 06 16 11 66 26 28 89 73 38 19 06 16 10 66 27 30 91 74 39 20 06 16 09 65 28 32 93 76 4l 22 07 17 08 65 29 34 95 17 42 23 07 17 08 64 30 37 97 719 A3 25 08 17 07 63 * Mean AR of 1 « Libre, 14" 40’ 58-21”. 1824.] Thirty-seven Principal Stars. 951 x Aquile | @ Aquile Mean AR} h. m. s. [h. m. s. 1824. | {19 4211°88/19.46 40-23 22% Capri.| « Cygni |« Aquarii |Fomalhaut| @ Pegasi |.Androm. in m. s. /h. m. s- |h. m. s [h. m. s. » jh, m. S&. 23 59 18°67 + 4:17") + 3:06") + 4:32") 4 4:95") 4+ 4:40’) 4 4°720 2) 53 59 15 03 31 95 12 3 51 58 14 ol 30 94 72 4 49 56 12| 298 29 94 72 5 48 55 ll 96 29 93 13 6 46 53 09 3 28 93 13 q 45 51 08 91 27 92 13 8 A3 49 07 89 26 91 13 9 42 48 05 86 25 91 13 10 40 AG 04 $4 “24 90 73 i 39 A5 73 12 31 43 13 13 85 42 13 14 34 40 72 15 32 39 72 16 31 31 72 7 29 35 72 18 27 33 72 19 26 32 71 20 24 30 val 21 €2 29 10 22 20 21 10 23 19 25 69 24 17 24 69 25 15 22 68 26 14 21 68 27 12 19 67 28 11 17 66 29 09 16 66 30 08 14 65 3l 07 13 64 Novy 1 05 11 63 2 04 10 63 3 02 08 62 4 ra 07 61 5| 2:99 05 61 6 98 04 60 7 91 03 59 8 95 01 58 9 94 00 58 10 93 | 2:99 5T 1 92 98 56 12 90 96 55 13 89 95 54 14 88 y4 54 15 86 92 53 16 85 91 52 17 84 90 51 18 83 89 50 19 83 89 49 20 82 88 A8 21 81 87 AT 22 80 86 A6 23 80 85 Ad 24 19 85 43 25 18 84 AQ 26 17 83 AS 27 16 82 40 28 15 81 38 29 15 sl 31 30 14 80 36 * Mean AR of I « Capricor. 20" 1 53°23”, 252 Corrections in Right Ascension of [Ocr, ei F- y Pegasi | Folaria a Arietis | a Ceti |Aldebaran Capella | Bee gTauri |x Orionis Mean AR) |h.m. s. h. h.'m.s. /h. m.’s. {h. mn. 's. th. bh. m. s. fh. m. s. 1824. 5/0 4 11170 BS 2-68 |1 57 16°42 2 53 5°44/4 25 50-015 3 42-21 5 é 5 5 15 10°52/5 45 38:93 Dec. 1) 4- 4-33" + 43-30" + 5° 28" +509"\+ 5:69") 4 7 46" 4. 4-96! + 6:25”14 5:36" 2 32 | 42-72 27 09 70 A8 | 97 26 38 3 31 42-14 QT 09 val 50 98 28 40 A 30 | _ 41-56 26 09 a2 51 5-00 30 Al 5 29 | 40-98 96 10 13 53 Ol 32 43 6 28 A040 25 10 74 55 02 33 45 7 27 39°80 25 10 75 57 03 34 A6 8 26 39°20 24 10 75 58 04 36 48 9 25 | 38°60 24 10 76 60 05 37 49 10 24 38°01 23 09 17 61 | 06 39 51 1] 23 3T°Al 23 09 ell 63 O07 40 52 1g 22 36:75 22 09 78 64 08 42 54 13 20 36:09 22 09 719 66 09 A3 55 14 19 39-43 21 09 80 67 09 A4 57 15) 18) 34-76 21 08 80 69 10 46 58 16 17 | 34-10 20 08 81 70 il AT 59 17 16 33°45 19 08 8 {pl 12 48 60 18) 15 32°80 18 07 8l 72 12 49 61 19 4) 32:15 17 OT 82 73 Ts 49 62 20 13 31-49 16 06 82 TA 14 50 63 21 12 | 30°84 15 06 82 74 15 51 64 22 Il | 30-15 15 05 83 73 15 52 65 23 10 29-46 14 05 83 76 16 53 66 24 09 28°77 13 04 §3 17 | 16 53 67 25 08 | 28-08 12 04 54 78 17 | 54 68 26) O07 27°38 11 03 84 TY | 17 55 69 27 06 | 26:69 10 03 84 80. 17 56 70 28 05 26:00 09 02 84 81 17 56 ‘71 29) 04 25°31 09 02 84 82 17 57 ql 30) 02 24°62 08 Ol 84 83 18 57 72 31) OL 23°98 O07 00 84 S4 | 18 58 13 Sirius | Castor — | Procyon Pollux | a Bate | Regulus | if Leonis F Visgaila Spicay tee Mean AR) |h. m. s. |h. m. s, Ih. h. m. s. |h. lb. m. s. j|h. m. s. |h. m. »m. Ss. 1824, § |6 37 23-49|7 23 21-46 7 30 53 2)7 34 32°15/9 18 56" “a 9 58 59°57)11 40 4°73/11 41 31 "86 13 15 56°07 Dec, 1\+ 4°55 |+ 6-06” | + 4:97|4 5°77") + 4°19" + 4:34” 4 3°54") + 3°63”/+ 3-14” 2 58 09 5:00 80 22 37 57 66 17 3 60 12 02 83 25 AO 60 69 20 4 62 15 05 86 28 Ad 63 12 23 5 64 18 OT 89 32 AT 67 15 25 6 66 21 Te) 9g 35 50 70 18 25 q 68 o4 12 95 38 53 73 $l 31 8 70 26° 15 97 Al 56 17 85 34 9 val 29 17 6-00 Ad 60 80 88 37 10 73 3) 19 03 AT 63 83 91 AO 1] 75 34 21 06 50 66 87 94 43 12 17 36 o4 08 53 69 90 97. A6 13 18 39 26 1] 55 72 94 4:00 49 14 80 42 28 14 58 16 97 03 52 15 82 As 31 16 61 19 4-01 07 His) 16 84 47 33 19 64 82 04 11 58 7 85 AQ 35 21 67 85 07 14 61 18 87 51 37 23 69 88 11 17 64 19 88 54 39 26 12 91 14 21 67 20 89 56 Al 28 75 94 17 24 70 21 90 58 AS 30 18 97 20 27 73 22 92 | 60 AA 32 80 5:00 24 30 76 23 93 | 62 46 34 83 03 27 33 19 24 94 64 A8 37 86 06 30 3T 82 25 96 67 50 39 88 09 | 34 40 386 26 97 69 52 Al 91 12 ST 43 89 27 98 val 54 43 93 15 40 A6 92 + 28) 99 | 13 56 A5 96 18 43 AQ 95 ; 29; 5:00 | 15 58 AT 98 21 | 46 53 938 20| ~~ 02 17 59 49 | 5-01 24; 50 56} 4:02 31) 03 79 61 51 04 27 53 59 06 1824.] Thirty-Seven Principal Stars. 253 pervs Pane |e Ca. ae = Sepent, Antares jaHerculis|aOphiuchi a Lyre | y Aquile Mean’AR 1 |b m. s. /h.m. s. |h.m. s. |h.m. s. him. s. (he ms. 1824, J 4 7 3833 li aT 9" 63 3 are “45 15 35 3647 1618 27:91:17 6 37°72\17 26 46°24 18 3058°99 19 37 53°68 Dec. 1) + 2:39" | + 9-99" + 1°80” | + 2-45" | 4 3-26/| + 2:08"| + 2-17” |+ 1:06”| + 2°63! 2 Al| 301 82 AGi tives. 2 09 17 05 62 3 43 04 83 48} 29 09 18 04 61 4 Ad 06 85 49} 30 10 18 04 61 5 A8 08 86 50) |e a8 10 19 03 60 6 50 | 10 §8 52 33 11 19} o2| 59 7 Ser inn | 18 90 54 | 35 12 20 ju. 02 59 8 55 | 15 92 56 | 37 13 21 02 59 9 58 18 94 | 58 39 14 21 | 02 | 58 16) «G1 | 20 96; 60, 41 15 22 02 58 Hig h644)-4; 23 98 62}. 43) 16 22|.) 01 |.) 58 12 66 25 | 9.00 | 64| 45} Vin om Paci Ol 57 13 69 28 02 66! 46 | 18 | - 94) Ol 57 14 72 30 04 68 | 48 19 25) Ol 5T 15 14 33 06 70 50 20/ #26) 00 57 16). 17 36 08 12, 52 22 | 281i, 00 56 12 80 39 10 74 | 54 23 | -_-98')". 00 56 18 83; 42 13 it | 56 25 30, +00 56 19 86 | 45 15 79 | 58 26 lial F100 56 20| 89! 48 17 | 81 |), Gt 28 $2 |. 00 56 21 92 51 20 83 | 63 99 | 34 00 56 Qs 94 53 22 86 | 65 31 35 ol 56 23 91 56 25 88 | 67 32 SIN O1 57 24, 3:00 59 Q7 90 | 170 34 SS ay 401 5T 25 03 62 30 93 nee TS 35 40 01 57 26 06 65 32 95 | 14 37| 4 01 51 27, 09 68 35 98 | 77 39 43 02 58 28 12 i 38 | 3:00 79 Al A4\} 02 58 29} 15 74| 40 03 82| 42 46; 02 58 30 19 7k 43 05 84 44| 48 03 59 31 22 SOMOS AGH) “OSL Ois ST. Mae) 2O750 03 59 |a Aguile | ¢ Aquile eet anieae a Cyyni ja Aquarii |fomashaut | a Pegasi | -Androm, Mean abl lh. m. s. he am. s._h. s. hem. s. hom. os {h. m. os. |hom. s. [ho m. s. 1824 _ eal $8) 19 46 40° 23,20 8 ‘W7 “0220 39 26°21/21 56 44°67)22 4754-34) \22 56 0°17|23 59 18 67 Dec, 1 |. 2:73! | + 279" 4 3-37” |4 1:61"\ + 3627, 4-24” |4 3:81" 4 4350 er fe 78 36 59 61 22 80 34 3 a) AGC See 57 60 21 79 32 4 aoe wot Soe 54 58 19 77 31 5 70 U6ell, 233 52 57 18 16 30 6 69 15| 32 50| 56 16 75 28 | i.) 1b | 38 48 55 15 74 QT epearGese ys. Ta ORS ins | SAT 54 14 13 26 9) 68 WAS A St 45 53 19). OP Oe a 10; «68 74 31 A4 52 11 7 23 1] 68 13 31 42 5) 10) |e? S710!) 25798 12 67 "3 30 Ay 51 09 68 Qi 13 67 13 30 39 50 its} 67 20 14, ‘67 13 30 38 49 07 66 19 15, 66 72 29 36 48 05 65 17 my Ge |) Ya’ ° 28 35 Aq 04 64 16 17} «66 7 6 8B 4, ) (S$4.]2 5 46 03 63 15 18 BGOie oie Tes|! | OGte |) MASaier AD Ol wiawase 13 19) 66 2» Seg 32 45 oo | 61 12 203i 66| 72 29 30 44} 399 | 60 11 21 66| 72)| 29 29 43 98 59 09 22 66 73 29 28 42 96 58 08 23) 67 13 28 27 42 95 57 06 24) + 6T 13 28 26 Al 94 | «- 56 05 25 67 Ra. | od Moi 24 AO 9g 54 03 26 «67 13 28 93 39 al 53 02 27 67 13). &8 22| 38 90 | 52 Ol ao Ge | TS 88 gi 38 89 | --5h| 3-99 29) 68 14 98 | 90 3 SB’. 41}, oD 98 30 68 | 14 29 19 3 87 49 97 31 69 | 4 29 | 18 36 86210. SAB 95 254 Rev. Mr. Emmett on the Expansion of Liquids. [Oct, ARTICLE V. On the Expansion of Liquids. By the Rev. J. B. Emmett. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Great Ouseburn, Aug. 14, 1824. Ir the temperatures be taken in arithmetical progression, the volumes of a liquid at those temperatures are the logarithms of a certain series of numbers in arithmetical progression, which latter are, of course, the reciprocals of a series of numbers in harmonical progression. This estimate is sufficiently accurate for the graduation of thermometers which require the true scale, the approximation being so near the truth, that for mercurial or alcoholic thermometers, the deviation will not be perceptible, except very near the boiling and freezing points. The rigorous law is connected with some mathematical investigations, which have not yet been published, but which will appear as soon as my health will allow me to make some requisite experiments and calculations. The true law is this: if the temperature increase in arithmetical progression, the volumes will increase according to the following law, an increasing geometrical x increasing arithmetical progression. As the common difference of the latter series is very small, it may be neglected, except for changes near to the two points named. This closely coincides with the table of expansions given by Dr. Thomson: the first column is the temperature ; the second, the volume of the liquid from the above tables; the third, the numbers to which column 2 are logarithms ; the fourth, the differences of the successive numbers of column 5. Mercury. Temperature. Volume. Log. of Diff. of numbers, BOs wat ok POQHAS aa oors 12594°5 9:48 See es Leb = 1 Seca 12603-98 *"°""" ee LI R ws cet == GED a es ws LeU Pecan 8 8:9 TAQ oa feos ae i ee aie TF ay Aka aa IY Ae ys ea eae —]424°...... LaBS0*O 2" ee 89 DOL ihe EE aeons 126395 **7°"" Sulphuric Acid. Temperature, Volume. Log, of Diff. of numbers. BO? 4. arc 100000 ...... 12591-6 ont BS oe abies aaa . 1RS12-6 5457109 Sia No RRR 6, | ae 19633:9.0° 73,1: Sag aes, ted EIEN isectite «(ADAH fs Ee 20:6 Ly he eer QED ceca 8's 12680-0a0.)* * 93+] 200 eooevee —3911 eeeeee 12703°1 -— 1824.] Mr. J. H. Patten on a new Air Pump. 255 Nitric Acid. Temperature. Volume. Log. of Diff. of numbers. HO? ncaa LOOQ0D: os 050 12589-2 44-4 TIS, vivax alas bin 5 heed BOIS nhs ane save EAL esc FBS hae an 126822 <*'°°° pete 140 gees —O182 ec cas 12788:9), °° ° "°° Water. Temperature Volume. Log. of Diff. of numbers a ss IGG cris, 12590-0 sik poetry (pent 12594 "ot SY acy aida — 694 ...... [os ot ies Alcohol. Temperature. Volume. Log. of Diff. of numbers. 20? dees is 10.1155 i eee 12604°8 ay, (Ue —1688 ...... 1208852 bo pairces 351 yee Fe 1673-3 its aaa Dy a k.d.9,5 —4162 ...... Wad Fe a ae a On account of the great expansion of alcohol, and the lowness of its point of ebullition, the expansion arising from the arithme- tical series, which has to be multiplied into the geometric, is very perceptible; in all the others, the equality of the differ- ences in the fourth column is less than the inevitable errors of observation. To show the comparative expansions, the volumes of the liquids should not be equal at a given temperature, but should be the volumes of weights which are proportional to the atomic weights ; then the above numbers will enable us to determine the relative quantities of caloric contained in the above volumes. These points will form the subject of a separate communicas tion. I am, &c. J. B. EMMETT. ArticLe VI. Account of a new Air Pump. In a Letter to the Editor from Mr. Joseph H. Patten.* (With a Plate.) I inctose for your inspection the draught of a pneumatic pump, which, | think, will, in a considerable measure, obviate the defects of those in common use. The construction is so simple that it will require but a small share of skill or ingenuity to put it together, and it will be less liable to get out of repair than the pumps now in use. The valves which in other machines * From the American Journal of Science. 256 Mr. J. H. Patten on a new Air Pump. [Ocr. are a great source of difficulty, may be made larger and stronger, and the apertures, of course, will be more accurately closed, without at all affecting the degree of exhaustion, The vapour arising from the oil necessarily used in all pneumatic instru- ments, is in this completely excluded from the receiver, and the vacuum in the exhauster being torricellian, that in the receiver will approach as near to it as the elasticity of the air will permit. The glass parts of the instruments can be obtained from any glass house, and the barrel (which would be more elegant of glass) can be made at any steam-engine or gun manufactory, and a clock maker will be competent to construct the brass work. The subjoined sketch, although not drawn by an adept in the art, will, | hope, give you an idea of it. It represents a vertical section of a ¢able pump, supposed to be divided directly through the centre, with one half of the wood work, to which it is attached. It is a number of months since I first thought of it; I then had one constructed with a barrel of sheet brass, and the plate of the pump of tinned iron; it was very coarsely done, and the exhauster was filled with linseed oi/, but notwithstanding its roughness, it far exceeded my expectations. I have never yet been able to get an iron barrel, as it cannot be procured here, and numerous avocations have prevented its being obtained elsewhere. Figs. 9 and 10 (Pl. XXXII) correspond in their lettering. In fig.9, AB, C D, EF, represent a vertical section of the instrument, G is a barrel of cast iron or glass, screwed firmly to the table EF, in it is the solid piston H moved by the rack work I. K is a glass globe. resting upon the table CD, of a little less capacity than the barrel G with which it communi- cates by the glass tubes L and M firmly cemented into the piece N and into the bottom of the barrel G. To the top of the globe K is cemented the thick cap O, through which are made two apertures, into one of which is screwed the stop-cock P com- municating with the plate of the pump R; over the other aper- ture rests the valve S opening into the atmosphere (the construc- tion is seen in fig. 10). In the globe K is a stiff wire ascending into the cock P a short distance, and on it is screwed the valve T; the other end descends into the tube L, and to it is attached the wooden or cork ball U. We will now suppose the piston H withdrawn, and the barrel G filled with quicksilver; the tubes Land M being open will be filled to the height of the dotted line. Put the piston carefully in so that no air shall be between it and the mercury. As the piston descends, the mercury rises, and when it reaches the ball U it floats it, and by means of the wire forces the valve T against the aperture that communicates with the receiver R, and as the mercury continues to rise, the air driven before it has no way of escaping but through the NS PLATE XE ail = moe TU Ooon goo oAoana Nas ; ee o f (— We ; as » happens to be even or odd, or between a = 0 or l and a = n — 2, the increments of a being 2. It is also evident if m be an integer, that the number of functional roots will be , and if x be a fraction, the number of roots wiil be equal to the units in the numerator of this fraction; so that if 2 be irrational or imaginary, the number of functional roots will be infinite. This solution being performed by the coeflicient may be called the coefficiential solution. § 2. Taking « v« = 2°, we have sin —_* a, if we expound k by ge Sy — eh whatever be the value of. Hence if b = 1, and introducing v Yr O71. Oa ceaeeees (6) ¥ 2 324 Mr. Herapath on the Solution of Wx = a. [Nov. which is another general solution of (1), and being obtained by means of the exponent may be called the exponential. The exponent in this case being put under the same form as the coefficient in the former case, admits the same observations with respect to the functional roots, &c. We may combine these two solutions, and have v Pipceion Alo atewbh ale any In this solution the coefficient 1" may be, but is not necessa- rily the same root as 1" the exponent; thatis, the indeterminate integers k of the coefficient and exponent are not necessarily the same. Hence the number of functional rocts in this expression is 2. For example, ifm = 2,v = 1, and ¢x = a, the number of roots is four, } I 1 Xv, — 2, ir ere This remark, therefore, destroys the opinion derived from the analogy of algebraic equations, namely, that the functional equa- tion J" « = 2, x being a positive integer, has as many roots only as m contains integers. It is indeed evident from the nature of arbitrary functions, that the number of functional roots is inde- finite, when the arbitrary function has its full scope; but when the arbitrary function is excluded, and not in any way antici- pated, the number of functional roots is the same as the number of algebraic roots of an equation of equal dimensions. In the preceding instance the arbitrary function is in part anticipated by the double solution ; and hence the reason that the number of functional roots exceeds those denoted by the index. § 3. If we set out with a function of the form a+ be e+du the 2d, 3d, 4th, &c. functions will evidently be of the same form. And because a, b, c, d, are indefinite, any function of this form may be conceived to be the 2d, 3d, or 7th function of a like form ; so that we may suppose xs ay + by, 2 t r= and Yr = —_— v CG. id. x + cet dau athe whatever be the values of 7 and f. Because VioHeVVr=Vt'z, it is manifestly immaterial whether in the value of J” x we sub- stitute for x the value of J‘ x, or in the value of J‘ xv we substi- tute for x the value of J’ x2; both results will be the same. Making, therefore, these substitutions, and equating the corre- sponding terms of the results, we obtain 1824.] Mr. Herapath on the Solution of {x = x. 325 BA Se As aie} a0) He ap tys es. «6 si (8) BO Be a, d= 0G adie) is tee) ES fame Sag ab Se a aI Se ese ee (10) Uh t= Ohal, -f-sohide== Othe iG, Gwe Oe ev (11) By (9) or (10) a, d, = a, d,; therefore, when a, = 0, d, = 0, and by (8) or (11) at the same time 6, = c,. This circumstance has been noticed by Mr. Horner. If also a, = 0, d, = o; for = = - = i = — = some finite positive or negative quantity. Supposing ¢ = 0, equas. (8) and (11) give ¢, = 0, d, =0, and b, = c, = 1, which brings out the obvious case v° his Because when a,,, = 0, 6,,, = c,,,, we have (9) and (10) bb, = c,c, Thatis the product of any two, and, therefore, of any other number of the component values of 6 which give a resultant value for a = 0 is equal to the product of two, or of the same number of corresponding component values of c; conse- be b, bo quently if b, = o,¢, = 0; for oat ath Assuming A, = — and ¢ = (v—1)r, we obtain by (8) A, —= A b, or Cw=1)r 41 Of, A=A._, b+ d, dy,_») snty ee Ciy—2) ee 1 b+ a, d, A,_.+¢, C(—2) i by taking ¢ = (v — 2) rin (10). Again substituting v — 1 for vin the preceding value of A, and putting the value of c,_., thus derived for its equal in the second value of A,, we shall have Baim pi As), PAs 2 Otero ce: (12) supposing p = 6, + c,and gq = a,d, — b,c, In like manner it is found that Piet Gs ee OS aie sh hes (13) Cem p OK 9 Cig B60 ees eer-erere Hh) ) DAES Sy OS a A) 7 en (15) where B, = b,,,C, = c,,, and D, = wr, Each equa. (12), (13), (14), (15), is evidently an equa. of differences of the second order with respect to v, the coefficients p, 7, being constant in relation to this v. The solution of either of them (13), for instance, by the usual methods, is ory ys HORN Ea cet Vn nanan eS r 326 Mr. Herapath on the Solution of Y'x =x. [Nov. in which Q; Q; are the arbitrary constants. Now if we assume q= —(5% ii and identify (16) with the well-known theorem 2 cos z (cosz + /—1 sin z)=cosuz + ¥ —Isinve we get 2B, = ( 2 cos z wl] sin 9) be ade s wine ve cn (17) Determining now Q, Q, from the conditions of (17) when » = oandv = ], we shall find after due reductions ee edt) ee Q= 1 (0, + ¢,) tan z aot (5, os cy) V/=1 Ql Dawe tan 2 And if R, R, be the corresponding arbitrary constants in the solution of (14), we easily perceive that VE) aide, =e ) -£Q (os vz+ 7 —1 sinvz) +Q, (cosv Consequently (b, + ¢,)° \ faa age (b, — c,) cos Z. Sin v z B. = aay’ 1605.8 2 hizcorenenann: : eceeceeees (18) and C, is the same expression with a negative instead of a plus sign before the second number under the vinculum { . In the same way if P, P, be the arbitrary constants of (12), it appeats that P = — P, and P = (7-* J =1sin2)~ 2 cos % Whence by + cy\?—! sin vg a he a eee. Ser (19) f Guy day F : ; Moreover since ry =, we obtain by introducing for d, its r r ++, Dy Cy - 5 5, + c,)? value “~**) and substituting for g its value — ae 4, (2 cos z)* (b, + cy)°—" . (2b, c¢ cos 22 — b,? — c,?) sin v z d,D.=d,,= (2 cos 2)"— 1, 2 a,(cos 2% + 1) sin 2 —~ se ee eee (20) Having now obtained general values for the coefficients in de” a, let us consider a little the limitations of the indeterminate quantity x. In the first place, it is plain that x must vary inde- 2 ond ; P : nesied : on Ee « ee pendently of v ; and in the next, it appears from g = (2 tos 5 (hy, + 0) . ¢ ee ap ee d,. — b,c, that x must never be ie &e. because then (cos z)? = 0%, which, unless b, = — c,, gives a,d, = — (@)*, that is, both a, and d, infinite, the one negative, and the other positive, Thirdly, x must never be 40, 1, 2,3, &c. OO b, . KK 2hkar e 2e08 — (6,.+ c,) sin =e 2 a, ( cos coe | 1) sin =r as, + Cr vkn. 1824.] _ Mr. Herapath on the Solution of |" x = «. 327 multiple of A, for that would give a,, = va, avalue Qv—1 which could never become = 0 by any finite value to v, unless at the same time 6, = — c,; and, therefore, the function could never be periodic. Fourthly, x must be such that when v = n, the order of the periodic function, sin vz must be = 0. Assume therefore x = =, and it is evident the first condition is satisfied by & being any independent variable ; the second by its never 5 ; 2? 2? 9? being a 0, 1, 2, 3, &c. multiple of the same index unless simulta- neously 6, = — c,. Finally, the fourth case is satisfied by k having integral values only ; for otherwise & varying indepen- becoming a &c. multiple of, and the third by its never dently of v could not generally give sin —<", and, therefore, a,, = o whenv = 2. Moreover it may be further observed, since by (13), (14), a, d, = a, d,, and consequently 6,,, — 6,6, = ¢,4. — ¢ ¢,, that k must be the same in a,, as in d,,, and the same in 6,, asin ¢,,; but not necessarily the same in a,, or d,, asin 6,, or c,,. This, therefore, gives the number of functional roots n° for the same form of ¢, and is another instance of deviation from the algebraic analogy. It arises from a similar catise to the preceding devia- tion, an anticipation in part, as it will presently appear, of the arbitrary function in the constants a,, b,, ¢,. For the sake of brevity, we shall adopt one common indeter- minate integer which will enable us to give our final result some- thing simpler. us Pars sn— 2'cos — (5, + €,) sin — n n n kn. vka y 2ha .. ukA (b,—c,) cos = Sin — (a—20-¢, cos —— + c?)sin =e n ee kn n * This formula is in many instances better adapted for practice and printing under the following form. is _k =——.Ccos —. n Vre = ce } . vk~ ki vk~ kK kn ,. vka sin =~ + cos qe ant $(6,+6,) cos, ——. sin—— + (b,—¢,) cos rr ethaes = kn vkn n n ( 2Qkr a, { cos — + 1) n i | vkn., BAG. 3 ¢ | @,+c,) cos ees i, —(b,—c,) cos Te sin — — ——————- —_—__—_——_-9 1 i) produced from the other by merely multiplying the terms of the numerator and denominator Aa kia n baiig ying 2 aa. vee (32-2 b,c, COS — + ct) sin —- .cOs — n : | y 328 Mr, Herapath on the Solution of Wx = 2. [Nov. This is another general expression for determining "x from " x= whatever be the value of v, r, orn, rational, irrational, or imaginary. Ifwe putr = v = 1], we easily deduce Mr. Horner’s expression for J x, namely, ( sqiLe-e- sah Beat iil Dit 2X b+ —2bcecos — +c? | | ae = Cr ye n — gr pct tees (22) 2a( cos ~~ +1) j which was investigated for positive integral values only of n, but which our general views show to be true for every value real or even imaginary. Let us now apply these theorems to a few examples. Suppose first that n = 2, and k = 1; then cos — =—1, and the value (b + c)? >=—————— which since the denominator vanishes 2a(cos A + 1) for d becomes must have b= — c. Differentiating the numerator and deno- minator twice with respect to cand a respectively, we obtain d= 8c? 2asr? are mutually independent, this value of d may be any thing, and hence d denoting differentiation. Therefore, because 3c and 2a F Bh Sa box pr=o@ badou tres ttre (23) is the solution of 22 =. It is rather curious that this solu- tion is obtained on the hypothesis of k= ; which Mr. Horner thinks cannot be, and obtained also from his own theorem. Again, let nm = 5 and k = 1, then by Gauss’s division of the 2 2 eel circle cos = = Z> aud therefore, a+bGex pr=o-' 28? —be(y 5—l) + 22? ! cC- —- — PP a(y 5+ 3) which is the first and only solution I have seen of )° « = x. I shall not for brevity’s sake stop to compute other cases of integral functions, but shall just give an instance, the first, I believe, that has been given, of the solution of a fractional func- 3 Sha. * See tion. Suppose » = zand& = 1, then cos —~ = cos-> = 1 : By ey and, therefore, (22 1824.] Col. Beaufoy’s Astronomical Observations, 329 phe cae ne vur= ¢ Be DCH Oe eee eee. (24) a which coincides with Mr. Babbage’s solution of {3 2 = a. And because > =1— : it is evident that /-* x ought to be the in 4 ; 1 verse of (24). Put therefore in (21) r =1, v = — G, and of course making k as above = 1. From these data, we have v ys V3 aoe BX Phat / 3 —_—_— = .- > Tr re sn —=> sn -—__- = — 5 2 n 3 2 Qa BAI , a We py Lae 1 baer pry Bey —_— = ad s —= — cos co 3 ) 3 3 . Whence b — =a ie: = § 1 a ox poitr=o Aide b pnt era 3 1 b—c ae re ? : BP—he+e ae ee rp Baris Pe at ree which it may be easily shown is the inverse of (24), or equal to | gee This method of solution may, for the sake of distinction, be called the algebraic. j (To be continued.) Articie III. Astronomical Observations, 1824. By Col. Beaufoy, FRS. Bushey Heath, near Stanmore. Latitude 51° 37’ 44:3” North. Longitude West in time 1’ 20:93”. Oct. 2. Immersion of Jupiter’s second § 13h 50’ 50’ Mean Time at Bushey. BARGER. a siirais'~ > evatieietele> Deis 13. 52 11 Mean Time at Greenwich. Oct.13. Immersion of Jupiter’s first §17 Ol O8 Mean Time at Bushey. BAfCLIStey cai ee as cine eivevel= ; 17 02 29 Mean Time at Greenwich. 330 M. Berzelius on Fluoric Acid: [Nov. ArTIcLE IV. On Fluoric Acid, and its most remarkable Combinations. | . By Jac. Berzelius.* I. Compounds of Fluoric Acid with Electropositive Oxides, or with the Saline Bases properly so called. Fruoric acid, which may now be regarded either as a hydracid, or as an oxygen acid, is distinguished before every other substance by its great capacity of saturation, which, according to my earlier experiments, amounted to so much as 72°71, and, as will be subsequently demonstrated, is even some- what higher than this quantity. With alkalies, it forms salts which are soluble in water, and which, when in a solid erystal- lized form, invariably possess either an acid or an alkaline reac- tion, as is the case with the borates, seleniates, arseniates, and phosphates. Ifa solution of a fluate be saturated until it pos- sesses a perfectly neutral reaction, and if it be thea committed to evaporation, there is always obtained, either an acid salt, while the supernatant liquid becomes alkaline, or the contrary, The fluates which I shail in this memoir style neutral, are those in which 100 parts of fluoric acid combine with a quantity of a base containing 74°72 parts of oxygen. Those containing an alkaline base, react as alkalies, and have a saline and weakly alkaline taste. Those whose base is an alkaline earth, are gene- rally insoluble in water, and in that case possess no reaction whatever. Fluoric acid forms acid crystallizable salts with all the alkalies, which possess a strongly and purely acid taste, and whose solutions in water rapidily corrode glass. All the colour- less crystallized fluates approach closely in refractive power to that of water: hence, when immersed in water, they appear semitransparent, and indeed their presence frequently remains unobserved, until the liquid is decanted. All the experiments alluded to in this memoir were made in vessels of platinum, ese when the employment of glass vessels is expressly men- tioned. : Fluate of Potash—a. The acid fluate may be prepared by mixing with fluoric acid a quantity of potash insufficient to pro- duce neutralization. During evaporation, a portion of the acid is dissipated, but the greater part crystallizes with the alkali on cooling. When obtained hastily in this manner, the salt forms an apparently solid mass, composed of broad plates, intersecting one another, and leaving numerous trapezoidal interstices, which * Abstracted from Kongl. Vet. Acad. Handl. 1823, St. II. Want of room obliges us to omit a comprehensive historical sketch of the experiments and opinions of preced- ing inquirers. 1824.] M. Berzelius on Fluorie Acid. 331 are filled with liquid. If a saturated solution be abandoned to spontaneous evaporation, the salt gradually crystallizes in rect- angular four-sided tables, with truncated lateral edges ; resem- bling the form which we would produce by truncating two oppo- site apexes of an octahedron so deeply, as to convert it into a table. Sometimes also it crystallizes in cubes. [tis very soluble in water, but its solubility is diminished in a remarkable degree by the presence of an excess of acid. When heated, it melts, ves off its excess of acid, and again becomes solid. The resi- due weighs 74-9 per cent. and consists of the neutral salt. When the salt is incorporated with six times its weight of oxide of lead, and ignited, there is expelled 11-6 per cent. of pure water, which, according as we consider fluoric acid to be an oxide or a hydracid, may be supposed either to have constituted a basis for the excess of acid, or to have been generated by the union of the hydrogen of the acid with the oxygen of the oxide of lead. The acid salt is composed, therefore, of an atom of fluate of potash and an atom of hydrous fluoric acid. b. The neutral fluate of potash is most easily prepared by supersaturating bicarbonate of potash with fluoric acid, evapo- rating the solution to dryness, and expelling the excess of acid from the residue by ignition. It has a sharp saline taste, reacts strongly as an alkali, and is excessively deliquescent. It is very difficultly crystallizable ; but if a solution be allowed to evapo- rate in a temperature between 95° and 104°, the salt may be obtained in crystals, which are sometimes cubes, and sometimes rectangular four-sided prisms. If 4 concentrated solution of this salt be neutralized with acetic acid, it may be evaporated to dryness without any of the acid separating ; nor can the acetic acid be completely expelled, or the original salt regenerated, except by subjecting the residue to ignition. The solution of this compound salt is strictly neutral while in a state of concen- tration; but if it be largely diluted with water, it actjuires a strongly acid reaction, and the acetic acid becomes at the same time disengaged. I consider this property to be very remark- able. A solution of this salt, even when cold, slowly attacks glass, and destroys its polish. This property, for which I can conceive no satisfactory explanation, at first appeared to me to be occasioned by a tendency in the neutral fluate to combine with an excess of base. To determine, therefore, if it be possible to produce a sub-fluate, I mixed a concentrated solution of the neutral salt with an alcoholic solution of potash ; but I could not perceive that any alteration was produced on its properties by this addition: 1 then fused a mixture of the neutral salt and subcarbonate of potash; but no carbonic acid was expelled, nor did the mixture sustain any diminution of weight. Hence it appears that a subsalt cannot be easily formed, so long at least 332 M. Berzelius on Fluorie Acid, [Nov. as the excess of potash is in a situation to combine either with carbonic acid or with water. Fluate of potash in a red heat dis- solves silica, and forms with it a transparent mass; and no sili- cated fluoric acid is disengaged, in temperatures below that necessary to melt glass. The mass on cooling has a white porcelaneous aspect, and water extracts from it a deliquescent salt. Fluate of Soda.—a. The acid fluate may be crystallized in transparent rhomboids. It possesses a sharp and purely acid taste, and is but sparingly soluble in cold water. It is composed of an atom of fluate of soda, and an atom of hydrous fluoric acid. b. The neutral fluate of soda is most economically prepared by mixing 100 parts of dry silicated fluate of soda and 112 parts of anhydrous subcarbonate of soda with as much water as will form with them a thin pap, and boiling the whole until it ceases to effervesce. After about an hour, the mixture concretes to a solid mass: this must be reduced to powder, and again boiled in water, so long as it effervesces. By this means we obtain a mixture of fluate of soda and silica: the former is to be sepa- rated by repeatedly washing the insoluble portion with water.* The solution, when slowly evaporated, deposits the salt in crys- tals. But with whatever precautions the preparation of this salt may be conducted, a small quantity of the silica invariably passes into solution : hence after the greater portion of the fiuate of soda has crystallized, the liquid becomes opalescent, being unable to retain the whole of the uncombined silica in solution. It must be evaporated to dryness, and the residue ignited, in order to render this silica insoluble. If any of the double fluate had escaped decomposition at the commencement of the process, it forms a part of this dry mass, andits excess of acid is expelled during the ignition ; the dissipation of the last portions may be ereatly facilitated by introducing into the crucible, while red- hot, a bit of carbonate of ammonia, and immediately after covering it up with its lid. Fluate of soda crystallizes in cubes and regular octahedrons: the crystals are transparent, and have sometimes the lustre of mother of pearl when viewed with reflected light. It is always obtained in octahedrons, when the solution contains carbonate of soda. Itis remarkable that the fluates of potash and soda are isomorphous with the muriates of the same bases (chloride of potassium and chloride of sodium), and also, so far at least as can be concluded from what has been already ascertained, with the analogous compounds formed by iodine. This salt is less fusible than glass. Water dissolves it very slowly ; and its solu- * The object of this process is to prevent the silicate from gelatinizing ; the gelatinous silica resulting from the decomposition of fluosilicates being sensibly soluble in water. 1824.] M. Berzelius on Flioric Acid. 333 bility is not in the least degree augmented by an elevation of temperature. At the temperature of 61°, 100 parts of water are capable of retaining in solution four parts of the salt. It is almost completely insoluble in alcohol. Fluate of Lithia—a. The acid fluate is a crystallizable salt, but little soluble in water. 6. The neutral fluate dissolves with great difficulty in water, resembling in the degree of its solubility the carbonate of lithia. The solution is converted by evapora- tion into a white mealy-looking mass, composed of opaque rranules. Fluate of Ammonia.—a. The acid fluate is a deliquescent salt, which may be obtained in the form of granular crystals by allow- ing a solution to evaporate in a temperature about 100°. 6. The neutral fluate cannot be procured by the humid way otherwise than dissolved in water; because when a neutralized solution is exposed to the open air, even in the ordinary temperatures, it gradually loses a portion of its ammonia, and is converted into the acid salt. It may, however, be easily prepared in the dry way by the following process. . Mix in a platinum crucible 1 part of sal ammoniac and 21 parts of fluate of soda, both tho- roughly pulverised, and in a state of complete dryness ; and cover the crucible with an inverted lid, filled with water, in order that it may be preserved sufficiently cool. Leta gentle heat be now applied to the crucible by means of a spirit-lamp : the fluate of ammonia will speedily volatilize without the slightest admixture of sal ammoniac, and will condense upon the lid in a mass of small prisms. This salt is permanent in the air: it is copiously soluble in water, but only slightly so in alcohol. When heated, it melts before it begins to sublime. In glass vessels it cannot be preserved even when dry, without corroding them. Ammonia, in the gaseous state, is rapidly absorbed by it, and the product is a subsal’, which is decomposed by subli- mation. Hluate of barytes is most easily obtained by digesting newly precipitated carbonate of barytes in an excess of fluoric acid: the carbonate is gradually converted into fluate of barytes, which remains undissolved. This salt is only very slightly soluble in water, or in an excess of fluoric acid. It dissolves abundantly in muriatic acid, and ammonia precipitates from the solution a chemical compound of fluate and muriate of barytes. The same compound may be formed by mixing solutions of fluate of soda and muriate of barytes. It is much more soluble in water than fluate of barytes, and by evaporating the solution, may be reco- vered in granular crystals. Repeated washings decompose it artially ; the residue upon the filter, however, when dissolved in water, retains to the last the property of precipitating nitrate of silver. I found it by analysis to be anhydrous, and to be composed of an atom of muriate and an atom of fluate of barytes. 334 M. Berzelius on Eluorie Acid. [Noy. It is, therefore, a double sak with two acids, or at least an -ana- logous compound. . { did not succeed in forming either a super or a subfluate of barytes. : Fluate of strontian may be prepared in the same manner as the preceding, which it closely resembles in its.inconsiderable solubility in water, or an excess of fluoric acid. Fluate of Lime.—The best method of obtaining this salt arti- ficially is to digest newly precipitated carbonate of lime in an excess of fluoric acid. When thus prepared, it constitutes a granular powder, which may be easily washed. When we attempt to prepare it by mixing solutions of a neutral salt of lime and a neutral fluate, it always precipitates as a jelly, which it is impossible to wash, because it speedily stops up the pores of the filter ; and it retains this gelatinous form even after having been evaporated to dryness, and digested in water. Its deposition is somewhat promoted by the addition of ammonia. Acids dis- solve it slightly when newly formed, and the addition of an alkali precipitates it from the solution unaltered. Sulphuric acid incorporated with finely pounded fluate of lime, whether prepared artificially or the native spar, converts it into a transparent syrupy mass, which may be drawn into threads; but no expulsion of acid takes place until the mixture is heated to a temperature of about 100°. The addition of water to the liquid renders it opaque, and causes the disengagement of fluoric acid. Concentrated nitric and muriatic acids render fluor spar transparent in,a similar manner, but the liquid is not so gluti- nous, and the mineral is precipitated unaltered by water. Ifthe fluor spar contains the slightest admixture of silica, it instantly effervesces when mixed with sulphuric acid. Fluate of lime appears to be isomorphous with the fluates of potash and soda. . Fluate of magnesia is insoluble in water, and in an excess of fluoric acid, Fluate of glucina is difficultly soluble in water ; but a solution saturated in a temperature of 212° deposits on cooling minute crystalline scales, which possess an astringent taste, and redden moistened litmus paper. Neither this nor the preceding salt is decomposed by ignition. : Fluate of ytiria is nearly insoluble, even in an excess of acid ; before being ignited, however, it has an astringent taste, and reddens moistened litmus paper. . Fluate of alumina is very soluble in water. A solution of it when concentrated forms a clear uncrystallizable syrup, and when evaporated to dryness, it leaves the salt in the state of a transparent, yellowish coloured, friable mass, resembling gum arabic. Thus prepared it is tasteless, and when put into water, appears at first to be insoluble, but in the course of about an hour, oe 1824.) M. Berzelius on Fluoric Acid. 335 it is completely dissolved, and it dissolves still more rapidly in boiling water. A subfluate may be obtained either by igniting the neutral fluate, or by digesting it in water along with hydrate of alumina. Fluate of xirconia is very soluble in water. The solution when evaporated deposits crystals, which when digested in water are decomposed into an acid salt which passes into solution, and a subsalt which remains undissolved. Fluate of Oxidule of Manganese-—A crystalline powder, per- manent in a red heat, and soluble in water, with the assistance of an excess of acid. Fluate of Oaide of Manganese-—A solution of the native hydrated oxide in fluoric acid has an intense red colour, and by spontaneous evaporation deposits this salt in transparent prisma- tic crystals, which are dark brown coloured when large, but ruby red when minute. In a minimum of water it dissolves with- out decomposition ; but if the solution be heated or diluted, a -subsalt precipitates, and an acid salt remains dissolved. Fluate of oxidule of iron may be prepared by dissolying. the metal, with the aid of a gentle heat, in fluoric acid; the salt gradually separates in small crystals, which appear to be rect- angular four-sided tables. When first obtained, it is white, but acquires a yellowish shade on exposure to the air. Water dis- solves it sparingly. Ignited, it gives off water of crystallization, and a smail quantity of acid : after this, it becomes red coloured, and sustains no further decomposition. Fluate of oxide of iron is obtained in the form of a crystallized pale flesh coloured powder, by dissolving the hydrated peroxide in fluoric acid, and evaporating. It has a sweet and astringent taste. Water dissolves it slowly, but completely ; the solution is colourless even when concentrated, and ammonia does not develop in it a deep red colour, as happens with solutions of the ordinary salts of oxide of iron. Ammonia added in excess pre- cipitates from this solution a subfluate. Fluate of oxide of zinc forms small white opaque crystals, which are difficultly soluble in water, but are copiously dissolved by ammonia. Fluate of oxide of cadmium is obtained by evaporating a solu- tion in the state of a white crust, which exhibits no indications of a regular crystallization. . Fluates of the Oxides of Cobalt, Nickel, and Copper.—The colour of the first is rose red; of the second light green ; of the third light blue ; in other respects their properties are so closely similar that a description of one may be accurately applied to the rest. They may be prepared by mixing the carbonated oxide with fluoric acid: it dissolves with effervescence, and the fluate is soon after precipitated in the form of a heavy powder. Tf an excess of carbonate be added, and especially if heat be at 336 M. Berzelius on Fluoric Acid. [Nov. the same time applied, the fluate thus formed is gradually con- verted into a subfluate. The neutral salts are only sparingly soluble in water. A small quantity of water dissolves them unaltered ; but an excess decomposes them into salts which are held in solution by the disengaged acid, and insoluble subsalts. The subfluates of nickel and copper have a pale green colour. The fluate of copper, when decomposed by sulphuric acid, yields 116 per cent. of sulphate of copper, and when ignited with ten times its weight of oxide of lead, gives off 26:3 p. c. of water. Hence it is a neutral fluate of copper combined with four atoms of water. The insoluble salt obtamed by boiling the preceding in water yields, by a similar mode of analysis, 158°2 p. c. of sul- phate of copper and 9:3 p. c. of water. It is, therefore, a sub- salt, composed of two atoms of peroxide of copper, one atom of fluoric acid, and two atoms of water.* Fluate of oxidule of copper may be formed by treating the hydrate with fluoric acid : it instantly becomes red, and does not dissolve in an excess of the acid. It must be washed with alco- hol. When ignited it assumes a dark cinnabar red colour. When exposed in a moistened state to the air, it at first becomes yellow, in consequence of half the base forming with the acid neutral fiuate of oxidule, while the other half forms hydrate of oxidule ; after some time it becomes green, and is wholly con- verted into the subfluate of oxide of copper. This saltis soluble in muriatic acid: the solution is black, and water precipitates the salt in the form of a pale rose red coloured powder. Fluates of oxidule and of oxide of cerium correspond in most of their characters with the fluate of yttria. Both occur native. The fluate of oxide of cerium has a yellow colour. Fluate of lead is slightly soluble in water, but not in an excess of fluoric acid. [t melts in a low heat, and after fusion appears yellow. Ammonia converts it very readily into a subsalt. This subfluate is soluble in water; when the solution is exposed for some time to the air, it becomes turbid, and a crust 1s formed upon its surface, composed of carbonate and fluate of lead. If a solution of fluate of soda be mixed with a boiling hot solution of muriate of lead, a double salt precipitates, which is to a small extent dissolved, but is not in the least degree decomposed by washing. This salt is white and pulverulent, and may be fused without losing either acid or water. I found it by analysis to be composed of an atom of fluate oflead and an atom of mumiate or chloride of lead. Fluate of oxide of chromium may be prepared by dissolving * Berzelius considers the atomic weights of oxygen, fluoric acid, oxide of copper, and water, to be 100, 270-34, 991-39, and 112:4354, If we represent them by the num- bers 1, 1°3517, 5, and 1°125, the neutral salt will be composed of one atom of acid, one of base, and two of water; and the subsalt, of one atom of acid, two of base, and one of water. 1824.] M. Berzelius on Fluoric Acid. 337 the newly precipitated oxide in fluoric acid. The solution has a rose red colour, and affords a pale rose red coloured salt by evaporation. _ Fluate of Oxidule.—A. green crystalline mass, easily soluble im water. Fluate of antimony is very soluble in water, and may be obtained in colourless crystals by spontaneous evaporation. Its taste resembles that of tartar emetic. Fluate of ovidule of tinis easily soluble in water, and crystal- lizes in white, shining, opaque prisms. It becomes rapidly per- oxidized when exposed to the air. Fluate of Oxide of Uranium.—A_ white pulverulent salt, readily soluble in water, and affording a yellow coloured solution. Fluate of Silver—A very soluble deliquescent salt, whose properties have been already sufficiently described by Gay- Lussac and Thenard. . Fluate of oxide of mercury crystallizes in dark yellow coloured prisms. Water decomposes these crystals, and a portion of the oxide remains undissolved, in the state of a beautiful yellow subsalt, resembling turpeth mineral. Ignited in a platinum vessel, the neutral salt sublimes, and forms light yellow coloured crystals ; but a portion of it at the same time undergoes decom- position, and the platinum is corroded. Ina glass retort it is instantly decomposed, and there distils over a mixture of sili- cated fluoric acid gas and metallic mercury. Ammonia con- verts this salt into a white coloured double salt, containing an excess of base. Fluate of Oxidule of Mercury.—I could not succeed in pre- paring, either by distilling the fluate of oxide with mercury by treating calomel with a solution of fluate of soda, or by evapo- rating over mercury a mixture of fluoric acid and a solution of nitrate of oxidule of mercury. In the last experiment, the nitrate of mercury reappeared in crystals, and the fluoric acid did not produce the slightest decomposition. Fluate of Ovide of Platinum —It is generally considered difficult to combine oxide of platinum with any other acid than the muriatic: this object may however be easily effected by dissolving in water a quantity of the salt of potash whose acid we wish to combine with the oxide, and by mixing the solution with muriate of platinum so long as it continues to produce a precipitate. A small quantity of the muriate of platmam and potash remains in solution, but by evaporating the clear liquid, the whole of this may be made to separate in crystals. 1 had recourse to this method in preparing the fluate of platinum. The clear liquid was evaporated to dryness, and the residue was treated with alcohol, which dissolved the fluate, but left the New Series, vow. vin. Z 338 M. Berzeiius on Fluoric Acid. [Nov. double muriate untouched. The alcoholic solution mixed with water, and abandoned to spontaneous evaporation, was gradually converted into a bright yellow coloured uncrystallized mass. This salt forms a double salt with fluate of potash. Saturating Capacity of Fluoric Acid—Frcm some experi- ments made, on a former occasion, with the utmost attention to accuracy, 1 concluded that 100 parts of pure fluor spar, when decomposed by sulphuric acid, yield 173-63 parts of sulphate of lime. I had still in my possession the specimen which had fur- nished materials for the preceding determination, and on repeat- ing the analysis with it, I obtained precisely the same result ; but being now better apprized of the circumstance that fluoric and phosphoric acids almost invariably accompany one another in the mineral kingdom, I was induced to examine the specimen more narrowly, and found that it was in fact contaminated with half a per cent of phosphate of lime mixed with some phosphate of oxidule of manganese. I ascertained the presence of these substances by digesting the gypsum in muriatic acid, precipitat- ing by ammonia, and treating the precipitate with water so long as any sulphate of lime passed into solution: the phosphates remained undissolved, and were instantly recognized by their behaviour before the blowpipe. The unavoidable errors attend- ant upon this method of analysis, however, rendered it impossi- ble for me to determine the quantity of the phosphates with perfect precision: I was, therefore, unable to deduce from the experiment the exact saturating capacity of fluoric acid. On this account, I resolved to repeat the analysis with a quantity of artificial fluate of lime, prepared with the utmost precautions to ensure the absence of every foreign admixture.’ ‘The acid which I employed for this purpose was prepared from pure fluor spar, and distilled sulphuric acid, in a distillatory apparatus of plati- num; and was received in distilled water, until the liquid began to smoke: in order still more to obviate the possibility of the presence of silica, the first fourth of the acid which distilled over was kept separate. This acid was mixed with a quantity of carbonate of lime insufficient to saturate it completely; and the fluate of lime thus formed was washed in a funnel of plati- num. On the supposition that the salt might still retain some silica, I mixed it with cold concentrated muriatic acid, and at the conclusion of an hour, washed it thoroughly with water. Had the slightest trace of silica been present, it. would have been dissolved out by this treatment, in the form of a double salt with the fluoric acid and lime. If fluate of lime, after ignition, can be moistened with fluoric acid without sustaining any elevation of temperature, it may be regarded as absolutely free from silica ; for if the smallest quantity of silica be present, this treatment always occasions asensible evolution of heat. Of all the fluates which I have examined, the fluate of lime was the 1824.] M, Berzelius on Fluoric Acid. 339 only one which I succeeded in freeing completely from the last portions of silica. 100 parts of the fluate of lime thus prepared and purified were digested in the state of an impalpable powder in concentrated sulphuric acid, and after a considerable interval, the mixture was evaporated to dryness and ignited. In different experiments, I obtained 174-9, 175, and 175°12 parts of sulphate of lime. Of these numbers, I consider the middle one, 175, to be the most accurate. According to this experiment, fluate of lime is com- posed of Phuonie, Qe vise ek 0 27225 y ccs. ty LOD Limes fly di dotece(s eit. oss 22°C RL Gy «css os BOG And the atomic weight of fluoric acid is 270°34, instead of 275, the number which { had previously given in my tables. It may, perhaps, be objected that the number 270°34 is not an equimul- tiple of 6:25, which has been considered as the true atomic weight of hydrogen, and which many philosophers are of opi- nion ought to divide without a remainder the atomic weights of all other substances. I do not think that any argument of general application can be deduced from the circumstance that the atomic weight of oxygen is divisible without a remainder by this number, and that the atomic weights of several other sub- stances approach very nearly to equimultiples of 6:25.* This number is so small, when compared with the atomic weights of most other substances, that it is generally exceeded by the un- avoidable errors of experiment; consequently, more decisive proofs than any hitherto obtained are required from this source, before the question can be finally answered. We are as yet acquainted with no physical circumstances which render this simplicity of relation a necessary law of nature, and uatil this be proved, we must continue to regard the supposed system of mul- tiples as very possibly nothing else than a seducing hypothesis- Be that as it may, the former atomic weight of fluoric acid, 275, which is an equimultiple by 44 of 6:25, is unquestionably too high. Those chemists who will be disposed to correct the new atomic weight in conformity with the supposition alluded to above, will make it 268°75, a number which certainly differs very Tittle from 270°34, but is in so far arbitrary, that it does not result from any direct experiment. Double Salts of Fluoric Acid with two Saline Bases.—The acid fluates of the alkaline bases possess a remarkable tendency to combine with a different base, in the proportion requisite to * From the experiments which I made in company with M. Dulong on the composi- tion of water and on the specific gravity of hydrogen gas, it follows that the atomic weight of hydrogen is 6-2177._ This number I have adopted in my tables, and it is obvious that a very inconsiderable deficiency in the number 6°25 would overthrow the whole hypothesis. z2 340 M. Berzelius on Fluoric Acid. [Nov. saturate their excess of acid ; nevertheless these combinations cannot be effected in the humid way with all the saline bases, for the mixture, in some instances, separates either by precipi- tation, or by crystallization, into two distinct fluates. The fluates of potash and soda do not combine, and if either of their acid salts be saturated with ammonia, the whole of that alkaliis gradually dissipated, even when the evaporation is performed in the ordinary atmospheric temperatures, and we again obtain the acid salts unaltered. One of the most interesting of these double salts is unques tionably the combination of jlwate of soda and fluate of alumina, which occurs in the mineral kingdom, and is known to mineral- ogists by the name of cryolite. It may also be prepared artifi- cially. Thus if a solution of acid fluate of soda be cautiously mixed with hydrate of alumina until it loses its acid reaction, the liquid becomes littie more than pure water, and when eva- porated leaves a mere film of the double salt, which had remained ‘in solution, As both the fluate of soda and fluate of alumina are readily soluble in water, this experiment of itself demon- strates that in the double fluate which precipitates the propor- tion of its constituent salts is such that both conta the same quantity of acid ; otherwise an excess of one or other of the two salts would have remained in solution. This compound may also be formed by digesting hydrate of alumina in a solution of neutral fluate of soda. If the experiment be made in a close vessel, the liquid, when the decomposition is effected, possesses an alkaline and caustic taste; if under free exposure to the atmosphere, the liquid attracts carbonic acid, and is found to be a solution of carbonate of soda. During the digestion, the alumina rapidly assumes the appearance of a semitransparent mass; but when dried, it loses the whole of its gelatinous aspect, and becomes white and pulverulent. To satisfy myself of the identity of these double salts with the one formed by nature, i subjected a quantity of cryolite to analysis. When ignited, it gives off neither chemically com- bined water, nor silicated fluoric acid. 100 parts were digested with sulphuric acid so long as fluoric acid continued to escape ; the mixture was then evaporated, until the greater portion of the excess of sulphuric acid was dissipated. The saline mass being redissolved in water, and the solution decomposed by ammonia, gave 24:4 parts ofalumina. The filtered liquid was now evapo- rated to dryness, and the residue was cautiously ignited, m order — to free the sulphate of soda from sulphate of ammonia and excess ofacid. The salt after fusion weighed 101 parts, equivalent to 44-25 parts of soda. Consequently 100 parts of the mineral are composed of 1824,] M. Berzelius on Fluoric Acid. 341 Fluoric acid (including loss) ........ 31°55 Sddais i. veces gai delaware be bine. A628 Alumina. s io.siecwe ey Adianysidns b.0RA4N 100-00 The two bases, therefore, contain equal quantities of oxygen, and saturate equal quantities of fluoric acid. A similar compound may be obtained by treating the acid fluate of potash with alumina; but it seems to depend upon weaker affinities than the preceding, for a dilute solution of the salt dissolves the hydrate without becoming turbid, and if the hydrate be employed in sufficient quantity to supersaturate the acid, the liquid filtered from the mixture is found to contain a large portion of neutral fluate of potash. The insoluble double salt may however be obtained in a state of purity, either by boil- ing the mixture, or by evaporating the liquid in contact with hydrate of alumina. Like the preceding it is semitransparent while moist, but white and pulverulent when in a state of dry- ness. Gay-Lussac and Thenard have stated that a solution of alum is precipitated by fluate of potash, but this precipitate can be made to appear instantaneously only by reversing their expe- riment ; for when a solution of fluate of potash is added gradually to a solution of alum, it does not occasion the slightest turbid- ness until its quantity is sufficient to form with the alumina the insoluble double fluate.» They mistook, therefore, this double salt for the simple fluate of alumina. In the analysis of minerals which contain at once alumina and fluoric acid, and whose decomposition has been effected by potash or soda, this combi- nation of the two fluates is always precipitated along with the alumina; and when this precipitate is violently ignited, the alumina displaces the fluoric acid from its union with potash, and there is obtained the usual sublimate of silica mixed with a little alumina around the lid of the crucible. The silica proceeds from a small quantity which had been precipitated along with the alumina, and both it and that earth are separated from the fluoric acid by the water which is formed by the hydrogen of the combustible, and are deposited around that part of the edge of the crucible, along which the gases make their escape. A double finate of ammonia and alumina may also be prepared by digesting hydrate of alumina either in the acid, or in the neutral fluate of ammonia. While still moist it has a semi- transparent appearance, like gelatinous silica, but is converted into a white powder by drying. When ignited, it gives off first ammonia, then acid fluate of auimonia, and subfluate ofalumina remains. It dissolves to a certain extent in pure water, but not in the liquid from which it is precipitated, nor in ammonia. The _ double salts of soda and potash are also soluble in water, but t0 a much smaller extent; indecd the latter may be washed with- 342 M. Berzelius on Fluoric Acid. [Nov. out any sensible loss. That lithia forms an insoluble double salt with fluoric acid and alumina is already well known; for the mineral called amblygonite consists of a compound of this nature mixed with a double subphosphate of the same bases. Fluate of alumina possesses a similar tendency to form double salts with the metallic fluates. I have examined its compounds with the fluates of the oxides of copper, nickel, and zinc. ‘They are in general more soluble in water than the simple metallic fluates; and, contrary to what takes place with the latter, they pass into solution without undergoing decomposition ; neverthe- less, like the fluate of alumina, after they have been once reduced to a solid form, a long time elapses before they can be again redissolved by cold water. The double salt of copper is pale bluish green, that ofnickel pale apple green, that of zinc colour- less ; and they may be all obtained crystallized in long prismatic needies by spontaneous evaporation. Ammonia precipitates from the aqueous solution an aluminate of the oxide. [have not entered more minutely into the investigation of these compounds than was necessary to demonstrate the remarkable tendency of , fluoric acid when in union with oxides which act not only very feebly as acids, to form double salts with the fluates of a differ- ent class of oxides, which invariably possess the characters of bases when combined either with the electronegative oxides, or with the weaker acids. Other oxides also, which, like alumina, contain three atoms of oxygen, as, for example, oxidule of chro- mium, oxide of iron, yield similar series of double salts, which are in general either insoluble, or very difficultly soluble in water. In most cases these compounds do not precipitate until the mixed solutions are heated. The double salts formed by fluate of oxidule of chromium with the alkaline fluates are grass green pulverulent precipitates ; those of oxide of iron are pale straw yellow, or almost colourless. The alkaline fluates containing an excess of acid resemble the acid sulphates, tartrates, and oxalates of potash or soda, in the great readiness with which they combine with other bases, par- ticularly metallic oxides, in order to form double salts. 1 have examined the double salts which they form with the oxides of iron, copper, nickel, cobalt, manganese, and zinc. They are in general difficultly soluble in water, and possess only a faint shade of the colour of their metallic oxide. ‘The alkaline fluates form double salts also with the fluate of oxide of platinum. They crystallize only from a very concentrated solution, and the crys- tals have a dark brown colour, more intense even than that of the simple salts of platinum. They are insoluble in alcohol. The fluate of uranium forms double fluates with the utmost faci- lity: most of them dissolve in water, and those containing an alkaline fluate shoot in yellow coloured crystals. Oxide of antimony also forms a series of double salts, which are crystalli- tf a: i a ~ ) 1824.] On Mr. Batiley’s Method of preparing Morphia. 343 zable, but are more difficultly soluble than those of oxide of uranium. The occasional differences observable between the preceding and Gay-Lussac and Thenard’s descriptions arise principally from these chemists having formed some of their fluates by double decomposition, by which they obtained double in place of simple salts. (To be continued.) ARTICLE V. Remarks on Mr. Battley’s Method of preparing Morphia. By W.A. South, Esq. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Aug. 10, 1824, In the Medico-Chirurgical Review for last June, I find a paper from Mr. Battley, professing to show “ the constituents of opium.” Mr. Battley states that “twenty-six pounds (avoir- dupois) of dry opium imparted to distilled water twenty-three pounds ” (rather more than usual, I think), “ leaving a residuum weighing three pounds when dried ; this residuum, or refuse, I apprehend to contain the morphium, and to the exposition of ¢his fact my present and immediate purpose is confined.” The fair inference to be drawn from this statement, the definite article the being used, I conceive to be, that the morphium is contained in the residue alone. How far this assertion is correct I will leave those to determine who have obtained morphia from the for- mulz of Robiquet, Choulant, Thomson, and others, when the aqueous infusion alone was ordered, and from which it would appear they were successful in obtaining the desired salt. That Mr. Battley might obtain morphia from the residuum of the opium after it had been submitted to the usual processes given for that purpose, I am perfectly aware, and as far as I canjudge, he might have added, in a greater state of purity. “The residuum of three pounds having been macerated in acetic acid produced, on the addition of ammonia in excess, a precipitate amounting to 38 drams 20 grains when dried, from which Mr. B. obtained morphia at the rate of 29 grains per dram. Mr. B. then “ proceeds to show a similar result from ‘the residual matter of tincture of opium, tincture bottoms.” This appears to be at the rate of 28 grains per dram of precipi- tate. So far Mr. B. seems to have been particularly fortunate, in showing “a similar result ;” but coupling it with the con- _ eluding paragraph of his paper, viz. “I must not now conclude, Without stating that Jaudanum, tincture of opium, does not con- 344 Dr. Henry on the Analysis of some of [Nov. tain any, or if any, only a very small portion of morphium,” he is I think particularly unfortunate. If Mr. Battley mean to say that the distilled water in which he had infused the opium did not contain any morphia, how does it happen that so many have obtained it from such a solution? and if he admit that it does contain morphia, where is the corresponding quantity from the opium infused in spirit, if it be not held in solution by the spirit? Unless Mr. Battley can state by what means the morphia can make its exit, I must consider that his experi- ments prove directly the reverse of his conclusions. W. A. Sours. Artic.Le VI, Experiments on the Analysis of some of the Aériform Compounds of Nitrogen. By William Henry, MD. FRS. &c. &c. (Concluded from p. 303.) 2.—Of the Analysis of Nitric Acid, Tue evidence of the composition of nitric acid, on which the view, now most commonly taken of its constitution, is founded, is derived almost entirely from synthetic experiments. Sir H. Davy long ago stated,* that 4 in volume of nitrous gas and 2 of oxygen gas, condensed in water, absorb 1 in volume of oxygen to become nitric acid. But 4 in volume of nitrous gas being’ equivalent to 2 of nitrogen and 2 of oxygen, the whole oxygen in nitric acid will be 5 volumes to 2 of nitrogen, or 2:5 volumes to one volume. The smallest proportion of nitrous gas found by Mr. Dalton to unite with oxygen gas, viz. 13 nitrous to 10 oxygen, gives the ratio in volume of nitrogen to oxygen, in nitric acid, as 1 to 2°53. M. Gay-Lussac also determined by the test of the red sulphate of manganese, which is deprived of colour by the nitrous but not by the nitric acid, that the latter acid only is generated when 134 measures of nitrous gas are made to com- bine with 100 of oxygen, proportions which indicate almost exactly 1 volume of nitrogen and 2°5 volumes of oxygen in nitric acid. But though the synthetic proofs rest on such high authori- ties, and all tend to the same point, yet it is desirable to confirm evidence of this nature by that of analysis, whenever it can be obtained; and the object appeared to M. Gay-Lussac sufli- ciently important to induce him to seek for this additional proof in two different ways, viz. by the decomposition of nitrate of * Elements of Chemical Philosophy, p. 264, + New System, p. 328, 364. $ Ann. de Chim, et de Phys. i, 404, 1824.] the Aériform Compounds of Nitrogen. 345 lead and also of nitrate of baryta, each without addition, at high temperatures. The results, however, for reasons which he has stated (same work, p. 405) were not satisfactory. Onagain reading his memoir, it occurred to me that a more complete decomposition of nitrate of baryta would probably be obtained by exposing it to a sufficient heat, in a state of intimate mixture with charcoal ; and that the elements of the nitric acid would be evolved in the state of carbonic acid and nitrogen gases, products which admit of being easily and exactly separated from each other. In my first trials of this process, I failed from the employment of too little charcoal, in consequence of which much nitrous acid vapour passed over, and acted upon the mercury over which the gases were collected. After repeating the operation several times, with various proportions of the materials, I found that by using at least 1 part of charcoal to 24 of the nitrate of baryta, nitrous acid vapour was no longer evolved. Inanexpe- riment made with great care, the barytic salt was finely pulve- rised, and exposed for a whole day, with surfaces frequently renewed, to a temperature of 212° Fahr. It was then mixed with the powdered charcoal, which had been recently ignited in a close vessel, to expel any moisture it might contain, and which was still hot ; and a portion of quartz in very small grains, equal in weight to the nitrate, was added to prevent the deflagration from being too rapid. The mixture was put into a green glass tube of the diameter of a common quill, into the upper part of which, before bending it so that it might pass beneath the mercury of the trough, a known weight of iron wire coiled into a spiral form was introduced. Under this part of the tube a double row of burning spirit lamps with flat wicks was placed ; and when the iron wire appeared red hot, the mixture at the bottom of the tube was heated by another lamp, at first mode- rately to expel any moisture, that might have been absorbed from the air while the tube was being filled, and then more strongly so as to set the mixture on fire. By slowly moving the flame of the lamp under that part of the tube which contamed the mixture, from above downwards, the combustion spread gradually through the whole, and the gaseous products were not more rapidly evolved than was consistent with their being wholly collected. They proved to be more complicated than expected; for not only carbonic acid and nitrogen were obtained, but nitrous gas, carbonic oxide, and a very small quantity of hydrogen, the last of which would indicate the presence of water in the proportion of about 0°7 of a grain to 100 of the nitrate and the materials added to it. In the tube there remained, besides charcoal, carbonate of baryta, with a very small quantity of that earth in its pure state, but no undecomposed nitrate. After separating the pure baryta 346 Dy. Henry on the Analysis of some of [Nov. by boiling water, the carbonate was dissolved out of the excess of charcoal by muriatic acid ; the solution decomposed by sul- phate of soda; and, from the quantity of sulphate of baryta, its equivalent in carbonate, and the quantity of carbonic acid in the latter compound, were determined. The analyses of the mixture of gases was made with the greatest care, and was thrice repeated. Reckoning up the oxygen contained in all the different products, and the nitrogen both free and in the nitrous gas, the volume of the latter was found to be to that of the former as 7:9 to 19°85, oras 1 to 2°51; thereby fully confirming that view of the proportion of the ele- ments of nitric acid, which had previously been derived from synthetic experiments. If then nitrous oxide be taken as the binary combination, in which the elements, nitrogen and oxygen, exist atom to atom singly, two volumes of mitrogen will contain the same number of ultimate particles or atoms as one volume of oxygen. And imagining the smallest possible volume of each of those gases, or a volume containing only a single atom, the ultimate volume of nitrogen will be double the ultimate volume of oxygen. Two measurable volumes of nitrogen, when chemically united with one of oxygen, or with two, three, or more volumes, will afford compounds of nitrogen and oxygen, in which the atoms will bear the proportion of one to one, or one to two, to three, or to more atoms. And as two volumes of nitrogen are, in nitric acid, combined with five of oxygen, that acid is justly consi- dered as constituted of one atom of nitrogen, the relative weight of which is 14, and five atoms of oxygen weighing to- gether 40. 3.—Analysis of Ammonia. Another combination of nitrogen, the exact analysis of which is of great importance, from the connection of the results with the law of volumes, as well as with the atomic system, is that into which it enters with hydrogen. Only one compound of those two elements, viz. ammonia, has yet been discovered, the decomposition of which, when existing as a permanent gas over mercury, may, as is well known, be effected by subjecting it to a long continued succession of electrical sparks, or of dis- charges from a Leyden jar. This method, originally discovered by Dr. Priestley, has been employed by the late Count Ber- thollet, by Sir H. Davy, by Mr. Dalton, and by myself, with a view to the accurate analysis of the gas. The process, how- ever, being one into which sources of error may easily be in- troduced, there is not so perfect an agreement, as might have been wished, among the results of different observers. Without entering into a detail of these discrepancies, or a statement of their causes, it may be sufficient to observe that the view of 1824.] the Aériform Compounds of Nitrogen. 347 the constitution of ammonia, taken by M. Gay-Lussac, repre- sents it as consisting of ] volume of nitrogen and 3 volumes of hydrogen condensed into the space of 2 volumes. In order to satisfy myself on a point, the determination of which is so essential to a just view of the atomic constitution of the compounds of nitrogen, I have lately made fresh expe- riments on the decomposition of ammonia by electricity, using every precaution that occurred to me as likely to insure the accuracy of the results. The gas was collected over recently boiled and dry mercury, and was transferred for decomposition into graduated tubes, filled with mercury, which had beem heated in the same tubes and still remained hot. To prevent any ammoniacal gas from lodging beneath the surface of the quicksilver in the tube, the flame of a spirit lamp was passed slowly along the part containing mercury, a precaution which was shown not to have been unnecessary by the ascent of a few bubbles of gas. In four experiments, conducted with a degree of caution, to which J am not aware that any thing could have been added,, the volume of the ammoniacal gas was fully doubled. In the first, 44 measures became 88 +; in the second, 157 became 320; in the third, 60 became 122; and in the fourth, 120 be- came 240, The evolved gases, carefully analyzed by combus- tion with oxygen, were found in each case to consist of ] vo- lume of nitrogen and 3 volumes of hydrogen. I repeated, also, with the greatest attention, a process for analyzing ammonia, which, with various other methods capable of being more quickly executed than that of electrical analysis, I have de- scribed in the Philosophical Transactions for 1809. It consists in firing, by the electric spark, a mixture of the alkaline gas with nitrous oxide, the latter being employed in rather less proportion than would be necessary for perfect decomposition, in order to prevent the formation of nitrous acid vapour, which is always generated when the nitrous oxide is in excess. For example, 10 measures of ammonia were deflagrated with 12 or 13 of nitrous oxide, the full proportion of the latter being, if pure, 15 measures. All the oxygen of the nitrous oxide was transferred to the hydrogen of the ammonia, water was formed, and the whole nitrogen of both gases remained as the acriform product, mixed with a small quantity of hydrogen gas, for the combustion of which the nitrous oxide had not supplied suffi- cient oxygen. ‘This quantity of hydrogen being too small to form a combustible mixture, it was necessary to make an addi- tion of that gas, and to employ, for the second combustion, more oxygen than was requisite to saturate the hydrogen added. The quantity of hydrogen, originally in the mixture, was thus easily determined, and, when added to the volume of pure ni- 348 X’s Reply to Mr. Daniell. [Nov. trous oxide expended, the sum expressed the whole hydrogen’ of the alkali. In this more summary method of analysis, results were ob- tained, which fully confirmed those established by electrical agency, all concurring to prove that ammonia affords, by de- composition, a quantity of nitrogen and hydrogen gases equi- valent to twice its volume, and consisting of | volume of ni- trogen and 3 of hydrogen. To preserve, however, an agree- ment between the theory of volumes and that of atoms, it is necessary rather to view ammonia as constituted of 2 volumes of nitrogen and 6 of hydrogen. For since 2 volumes of hy- drogen unite with 1 of oxygen to form water, every ultimate volume of hydrogen, (on the supposition that water is consti-' tuted of an atom of each of its elements) must, like the ulti- mate volume of nitrogen, be double that of oxygen. Two appreciable volumes of nitrogen, and two of hvdrogen, will contain then the same number of ultimate particles or atoms, and multiples of 2 in volume of either gas, will be multiples of the numbers of single atoms of hydrogen or nitrogen. It must’ be acknowledged to be remarkable that the only known com- pound of nitrogen and hydrogen should, according to this view, be constituted of one atom of the former element and three of: the latter; and that, during the decomposition of ammonia by’ electricity, those elements, disunited from each other, should not recombine in new proportions, as happens to the elements. constituting the aeriform compounds of nitrogen and oxygen, when subjected to the same decomposing influence. ArticLe VII. Reply to Mr. Daniell. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Oct. 15, 1824. Mr. Daniexu having replied to my remarks on a part of his work, { hope you will give a place to what follows: In Mr. D’s first quotation he might have put the words “ other circumstances being alike,” in italics, the scope of my paper plainly showing that no effect of heat, except that of dilating the tbe and its contents, was to be matter of discussion in as far as he was concerned. This restriction being now accurately understood, f proceed. In the matter at issue between us, I must take the liberty of saying, that Mr. D.’s reply is totally incomprehensible and irre- levant. Mr. D. is the first who ever used the fraction of the apparent dilatation of mercury for correcting the observed height of the barometer; and since all writers, without excep= 1824.] X's Reply to Mr. Daniell. 349 tion, have taken the absolute quantity as the foundation of the requisite correction, it is needless here to name individuals who sanction the practice. There is reaily no imaginable case in which any other fraction can be applied, as it, and it alone, indicates that alteration in the specific gravity of the mercury, from which solely the necessity arises for the correction m question. It would seem that Mr. D. confuses the nature of thermome- tric dilatation, with that which takes place in the barometer ; perhaps he has not duly reflected that the fluid in the one in- strument is isolated, and in quantity definite, whereas the ba- rometric tube being an open vessel, allows the mercury to have free egress and ingress, whether these motions are caused by. change of temperature or pressure of the atmosphere. Were a column of mercury contained in a tube closed at, the lower end, then indeed its expansion would be expressed by the fraction which Mr. D. contends is the proper one for baro- é ; I ; metric correction (ar 2 ), but this would be a thermometer, the action in which depends on vicissitudes of temperature alone ; not like that in a barometer, which is modified, or rather mainly produced, by a cause altogether different. A case, however, shall be taken which will, I presume, be deemed conclusive. Suppose three barometer tubes standing in a reservoir, and filled alike with mercury, but that one of the tubes expands by heating, that another contracts, and that the third neither expands nor contracts: no one will pretend to say, that if this apparatus be exposed to various temperatures, the columns in all will not rise to precisely the same height ; here, therefore, as in every other case, the expansion or non- expansion of tubes may be utterly disregarded. Moreover, as Mr. D. trusts to M. Biot in another matter, (of which below,) he may like to hear his opinion in this, by way of argumentum ad hominem; M. Biot says, tom. i. p. 86, “ Dans cette recherche, 7/ est znutile d’avoir egard a la contrac- tion du tube du barométre. Ce tube il est vrai, se resserre aussi par le refroidissement ; mais sa largeur n’énflue pas sur la hauteur de la colonne du mercure soulevée par l’atmosphere,” and in accordance with this decisive explication, he constantly ; , : 1 j uses the fraction of absolute dilatation is for correction as to temperature of the column. There is but one conceivable way in which the expansion of glass would require to be attended to: if the graduation, or inches for measuring the height of the column, were engraved : 1 MG tee? asta P on a plate of that material, then ye (¢/ 1 = lig) or hi- neal expansion, becomes the compensating quantity for 180 350 X.’s Reply to Mr. Daniell. [Nov. degrees of difference of temperature ; whence is obtained for the number of degrees which the existing temperature is above : d : or below 32°, the small fraction sa160 3) 2nd not a fraction de- + rived from that of the cubic dilatation of glass sai , the number for which Mr. D. would insist, and which is in effect used also as one of the elements in the construction of Mr. Rice’s table. For a scale on a plate of glass, the correction would be affirm- ative for degrees above 32°, and negative for those below that standard point, because in the former of these cases any line on the scale would be zz advance of absolute or unexpanded distance, and vice vers. This, however, is contrary to what Mr. D. says, if I have been able rightly to conjecture what he means by measuring upon a scale of glass. As there is something portentous in the manner in which Mr. D. alludes to M. Biot, I shall, with due deference show where his error lies ; to that gentleman truth will be acceptable from ‘whatever quarter it may come. In treating of absolute dilatation M. Biot says, “ Elle est plus forte que la dilatation apparente, comme cela doit étre,” but precipitately he adds, “ puisque celle-ci n’est réellement que l’excés de la dilatation propre du mercure sur celle du verre ;” in one sense this may be true, but not in the way M. ‘Biot understood it, he having made that a case of addition, which is one of division. In the preceding page (51) this ap- parent dilatation of mercury is stated to be =, and it appears 1 = is taken as the cubic dilatation of the from page 161, that 3 1 i vessel, (ie = (en. of course, to find that of the mer- 1142 380 } ] 1 1 ; cury M. Biot makes Src begant Shue Now,.not to mention an immaterial slip in this summation, the rule itself is fal- : i Ves ae . ; lacious, , + | 18 not the absolute dilatation in question ; AV i ERA ‘ —__. — M* being the legitimate formula, which, as well as A+V+1 S 8 ? its two converse forms, holds universally true. In M. Biot’s 1 - aw eran 5yi9? the number used in the subsequent parts of his work. This oversight is not exclusively M. Biot’s: Dulong and Petit, together with every writer on the subject, whose works I have perused, agree with the most ex- 1 lalaiens 1 case therefore — is —— and not * Whoever chooses to investigate this, will perceive that the symbols represent the volumes at 32°, as each of them plus unity does at 212°; or in other words, they are severally denominators of the fractions of the apparent dilatation of mercury, and of the absolute dilatations of the vessel and of mercury. ; ; ; 1824.] On Steam- Engines. 35) emplary uniformity in perpetuating the error. Mr. D. however, seems “ perfectly assured that they are fully competent to de- fend themselves, if they think it worth while.” With regard to the depuration of mercury, Mr. D. mentions how I may extend my knowledge. [I am myself a workman, although of name too obscure perhaps, ever to have reached Mr. D.’s ear; half a century, however, of experience in the habitudes of mercury, has enabled me duly to appreciate all available sources in information. Surely Mr. D. does not imagine that any personal allusion was intended by the words mentioned in his concluding para- graph ; they were used merely in odium philosophorum, and still must I be permitted to think the expression most appropriate. Even at this hoar no one knows with certainty whether mercury expands = or Le and in choosing a number each must be guided by vague predilection. Hoping, however, that Mr. Daniell and I part good friends, I promise, in the event of his coming to take the altitudes of the Grampian range near which I reside, that he shall be shown how to detect the most minute impurity existing in mercury, by inspection of a single drop of that metal. ; Articue VIII. On the Advantages, the Inconveniences, and the Comparative Danger of High, Mean, and Low Pressure Steam Engines. (Extracted fromthe Report to the French Institute, by MM. Laplace, Prony, Ampére, Girard, and Dupin.) Tue subject resolves itself into the two following questions : 1. What are the relative advantages of mean and high pres- sure steam engines? and 2. What is the danger that attends them ? First Parr.—Comparative Advantages of High Pressure Engines. Amongst the advantages of high pressure engines, that of occupying the least possible space must be enumerated, and will be the more important, as the space for their erection is more confined, or the ground more valuable: where manufac- tories, and private houses, are so crowded together that each establishment can obtain but a very limited space, and great power is at the same time necessary, this advantage is particu- larly felt; and it is no less important in the interior of mines, for the same reason. 352 On Steam-Engines. [Nov. - A second advantage of high pressure engines, and one that is even greater than the former, is the economy of fuel which results from the effects of a high temperature. This will be readily granted, when it is stated that the repairs and expenses of the steam-engines employed in draining a single large coal- mine in England, amount annually to the sum of 25,5000. On this account several large proprietors of copper and tin mines, in Cornwall, adapted machinery to their engines, in 1811, by which an account is regularly kept of the work which they perform ; and, from the results of these experiments, con- ducted on the largest scale, the comparative effect of the dif- ferent kinds of engines has been ascertained for more than ten ears. In the month of August, 1818, the Cornish steam-engines raised 15,760,000 lbs. one foot high, for each bushel of coals consumed. From December of the same year, the improvements were so material, either in the management of the engines, or in some of their parts, that the mean total product was increased to 17,075,900 Ibs. By a series of similar improvements, and by the construction of new and more perfect engines, the product was, In December, 1812, 18,200,000 lbs. -———_——- 1814, 19,784,000 1815, 20,766,000 and since 1815, the product is even still larger, in conse- quence of the improvements that have been made in the con- struction of the fire places, and boilers, and in short in every part of the machinery. At the present day, it is calculated that Watt’s improved steam-engines raise more than 30,000,000 lbs. of water one foot high, by the consumption of one bushel of coals. By the side of this augmentation we must place that which results from the employment of Woolfe’s steam-engines, which, as is well known, are condensing engines, and work with a pressure intermediate between that of the high and. the low pressure engines. Such a machine, with a double cylinder, has been constructed for the mine Whealvor, in Cornwall; the diameter of the large cylinder is 53 inches, and that of the small one 5:3 inches. This engine has raised 49,980,822 lbs. one foot high, by one bushel of coals, whilst the mean product of the other engines was only 20,479,350 Ibs. raised to the same height. In 1815 the mean product of two of Woolfe’s engines was 46,255,250 Ibs. One of the inconveniences attending engines of mean and high pressure, is loss of power by the wear of the more delicate parts of their structure, and the consequent loss of steam; at a. eo . 1824.] On Steam- Engines. 358 the same time it must be admitted that the improvements in the construction of the steam vessels have materially lessened this serious evil. The preceding statements respecting the Cornish steam- engines, is taken from the reports published by Dr. Tilloch, in the Philosophical Magazine; and the more recent English En- cyclopeedias confirm the facts which have been stated. Experiments made in France support the truth of these re- ports. MM. Girard and Prony have made separate compara- tive experiments on the power of low’pressure engines, and the condensing engines of mean pressure on Woolfe’s system, as unproved by Edwards. ‘They find that the latter deserves the preference, as to economy of fuel, though their results do not exactly agree as to the extent of the saving in this respect; their conclusions, however, tend to the same end, and their dis- crepancies are referable to particular circumstances. Instead of estimating the power of a steam-engine by assum- ing the vague and ill-defined power of a horse as unity, it would be better to assume a given weight, raised to a given height in a given time ; as !00 weight raised one yard in a second, which might be called a power. The working force of the engine would thus be indicated by the number of powers it is equal to, which may easily be ascertained by loading the piston with a sufficient determmate weight, and marking the space it passes through, so loaded, in one second of time. The tension of the vapour beg measured by its relation to the pressure of the atmosphere, taken as unity, it must always be referred to the standard barometrical pressure of 30 inches, and the temperature of 32°. According to the preceding details, it may be assumed as incontestable, that it is most economical to employ steam at such a temperature, that its tension shall be equal to that of several atmospheres ; but it is not so easy to decide to what exact tension it should be raised ; or what is the mathematical law which expresses the product of steam-engines’ powers in the function of the temperature, and the tension resulting from it. “ We have hitherto,” says the report, “‘ compared low pres- sure engines only with those of mean pressure ; we now proceed to compare them with high pressure engines, which, as is well known, act without condensation of the vapour. Mr. Trevithick, in England, and Mr, Oliver Evans, in Ame- rica, are the persons who first made high pressure engines, In 1314 Mr. Trevithick exported to Peru nine of these engines, for the purpose of clearing the mines of water, from the accumulation of which many of the richest had been aban- doned ; so effectuul were the engines, that the treasurer of the province proposed to erect a silver statue to Mr. Trevithick, as New Series, vow. Viti. 2a 854 On Steam-Engines. [Noy. a memorial of the gratitude of the new world, for the services he had rendered it. In Philadelphia, the saving in fuel by the substitution of one of Evans’s high pressure engines for the low pressure one pre- viously employed, amounted to about 1256/. perannum. This engine raises 20,000 tons (¢onneaux) of water, about 98 feet in height, every 24 hours, and consumes about 1585 cubic feet of wood per diem. The prime cost of the machine was rather more than 5000/.; whereas, according to M, Marestier, a low pressure.engine, of equal power, would cost considerably more than 8000/. Eyans’s engines work with a pressure of from eight to ten atmospheres ; several of them have been constructed in Ame- rica; and in 1814 the Congress of the United States extended Mr. Evans’s patent 10 years beyond the usual period, as an acknowledgment, on the part of the republic, of the benefit his invention has conferred on his country. A similar extension was granted in England, to Messrs. Boulton and Watt, for their condensing engines. ‘«¢ More lately Mr. Perkins, an American, well known by his ingenious processes for employing steel plates instead of copper in engraving, has surpassed all his predecessors by the boldness of his conceptions. He employs, for his moving powers, steam under a pressure of more than 30 atmospheres, and apparently with great advantage. «‘ With respect to economy of fuel, we must, therefore, con- sider the high pressure engines, hitherto constructed, as not having attained the maximum. The use of condensed steam is yet in its infancy; and, notwithstanding the services it has already rendered us, we must consider them as far below what may still be expected, when we shall be more capable of avail- ing ourselves of the full benefit of its effects.” Srconp Panr.—Measures of Safety. Habit reconciles us to danger. Hundreds of sailors perish annually by the power of the wind on the sails of our ships, and we think nothing of it, because we are become familiar to that mode of navigation. But if a steam-boat be blown up, or burnt, the accident is reported in the public prints to every corner of the world; the alarm is given, and that is looked upon as the most dangerous of all mechanical powers, which perhaps is the least so inthe common course of nayigation, and especially on nearing the land. But destruction in some shapes is more appalling to the ima- ination than in others. Death from explosions, accompanied with noise and confusion, seems more horrible than when it comes in a more tranquil form; and in all our discussions on the relative dangers of different machines, we should divest 1824.] On Steam-Engines. 355 them of those accessary circumstances, which frequently pro- duce the greatest effect on the minds of the yulgar and ill- informed. Whenever man accumulates natural powers to effect certain purposes, they may, by mischance, be diverted from their proper courses, and become the cause of serious accidents; and no machine, by which those powers are concentrated, was ever constructed that has not its peculiar dangers. To wish to employ only such machines as might be secure from the consequences of want of skill, imprudence, and rash- ness, were to wish to deprive ourselves of the happiest fruits of human skill and industry ; at the same time it were a culpa~ ble neglect to suffer any man, for the sake of attaining an end of secondary importance, to employ means which might obvi- ously endanger the lives and property of his neighbours. In such a case, public authority has a right to interfere, and exer- cise a beneficial and protecting influence. Does this observation apply to steam-engines in general, or only to a particular class? Should the use of high and mean pressure engines be restricted to certain situations ? The British Parliament has lately taken this subject into serious consideration, and has adopted most of the precautions recommended by a Committee of the House of Commons, appointed to inquire minutely into it, particularly with the view ef obviating the dangers to which steam passage-boats are liable from ill-constructed machinery, carelessness, or misma- nagement. The Committee particularly recommended, that the boilers of the steam-engines shall be made of wrought iron or copper, and furnished with safety valves, of proper size and form, one of which shall be so secured as to be inaccessible to the workman who has charge of the engine: it also recom- mends that this valve shall be loaded only with such a weight that the pressure shall never exceed one-third of that, which the boiler has been found, by actual trial, to be capable of supporting without bursting, or one-sixth of its calculated strength ; and that any person overloading the valve shall be liable to punishment. Altiough the British Legislature has not forbidden the use of high pressure steam-engines, either in passage-boats or ma- nufactories, the preference has been given, especially for boats, to low pressure engines; and much prejudice has been excited against the former from deplorable accidents which have occur- red in America, in England, and France. Mr. Evans, however, according to Mr, Marestier, has defied his opponents to produce a single instance of the explosion of one of his engines, although they work with a pressure of 10 atmospheres. ut serious accidents are not confined to high pressure engines—they have happened with those of low pressure, both 2Az 306 On Steam-Engines. [Nov. in England and America; and more than once, explosions occasioned by the latter have been attributed to the former. An account is given by Mr. Stevenson, in the Edinburgh Philosophical Journal,* of a dreadful explosion which oc- curred near Edinburgh, of a high pressure steam boiler; and in France accidents have happened both with low, mean, and high pressure engines, which require our particular attention. Explosions, which have cost many persons their lives, have happened with what are called low pressure engines, but which in reality cease to be such whenever the fire is strongly urged, and the escape of the condensed steam prevented, either by the accidental derangement of the safety valves, or by its being purposely overloaded. Amongst others, we may mention the deplorable accident which happened at Creusot, by which many individuals were killed, by the bursting of the boiler of a low pressure engine. Let us turn to the other engines. At Péronne the balance beam of an English high pressure engine having broken, the steam in the cylinder drove up the piston and its rod through the planks and roof of the building in which it was placed ; but no person was killed or hurt. At Paris the lower part of the boiler of a mean pressure engine having split, the water flowed into the fire-place, and put out the fire ; the walls of the furnace were not even shaken, and no noise was heard except that of the rupture of the boiler. A similar accident occurred about three years since in another establishment, unattended by any more serious consequences. But at Essonne a more serious accident happened lately with a mean pressure engine, the boiler of which had been cast at a foundry not calculated for such work ; and it has been satis-' factorily proved, that the mischief was occasioned solely by the clumsy construction of the boiler, and the faulty manner in which its parts were put together. It results, from all the details which we have collected, that no mean or high pressure steam boiler, constructed in any regular establishment in France, has ever met with an explo- sion ; although they are more numerous than those imported from foreign countries. During the last year 36 of these en- gines have been made in one manufactory at Paris, and a still greater number are making in the present year; and the more they are used the more they are approved of. Since 1815 more than 120 mean and high pressure engines have been made in the French manufactories. Since 1815, 32 mean pressure engines have been sent to. St. Quentin, from one manufactory at Paris ; and the purchas- ers are universally well satisfied with the service they perform. * Vol. v. p. 147. This boiler was erected for boiling the stills of the Lochrin Dis- tillery, by high pressure steam.—C. 1824.] On Steam-Engines. 357 It became important to ascertain if the safety of the French engines, from their introduction to the present time, be merely owing to chance, or if it be the necessary consequence of mul- tiplied precautions in their manufacture, and the previous trials to which the boilers are submitted. On this point the following information has been obtained respecting the cast iron boilers, which are considered as the most unsafe. The mean-pressure, condensing engines, on Woolf’s con- struction, are those which are made in the principal manufactory in France. With these engines the pressure may be varied from that of one atmosphere to two and a half, or three atmo- spheres, and is indicated by a mercurial gauge. The true boiler and boiling pipes in Woolf’s engines (which must not be confounded) are made of the purest cast iron. The form of the boiler is cylindrical, its axis being horizontal. The thickness of the boilers and boiling pipes of large and small steam-engines, varies from about an inch and a quarter to an inch and three quarters. The diameter of the boiling pipes is much less than that of the boiler; for small engines it is less than half, for large engines less than one-third of the diameter of the boiler. The axes of the boiling pipes are parallel to the axis of the boiler ; they are placed below it, and immediately over the fire- place, in such a way that the flame is in contact with the pipes only. rf the boiler is less exposed to the fire than the pipes, it is less subject to injury from its action; and if any part give way from that cause, it is the lower part of the pipes and not the boiler; the consequence of which is the inundation of the fire- place, and extinction of the fire, as happened in one of the accidents mentioned above. The parts of the engine are united with every possible atten- tion to strength, and to closeness at the joints, so that there may be no loss of power from the escape of steam. Before the pipes and boiler are used, they are separately submitted, by a hydraulic press, to five times the pressure that they will have to support when the engine is at work. Before any conclusions are drawn from the preceding facts and observations, it may be well briefly to recapitulate them. High-pressure steam-engines are employed with most adyan- tage. flat, Because the greater the compression of the steam, the less is the space the engine occupies. 2d. Because it produces an equal power to that of a low- pressure engine, with a smaller quantity of fuel. But they are considered as more dangerous than low-pressure engines. Nevertheless engines may be constructed, with which 358 On Steam- Engines. [Nov. explosions, if not absolutely impossible, are at least extremely rare; and with which nota single instance of an explosion has occurred in France, since they have been used in that country. Such are the mean-pressure engines, of three or four atmo- spheres, made in France, on Woolfe’s construction, as improved by Edwards, with boilers four or five times stronger than can be burst by the force of the steam which they have to resist. Such also are the high-pressure engines of 10 atmospheres, constructed on the plan of Oliver Evans, of the United States of America. With these engines the boiler is capable of resist- ing ten times the force it is daily subjected to. But engines constructed with less care, or managed with less prudence, have occasioned dreadful accidents, especially in Great Britain. In France only one accident has ever happened, by which any lives were lost, which were those of two individuals engaged - in the service of the engine; and not one single instance has occurred in that country, in which any damage has been sus- tained by any individuals, from the explosion of a steam-engine on the adjoining premises. Although it appears, from the preceding statement, that no one in the neighbourhood of a steam-engine, in France, has ever suffered either in his person or property from any explo= sion, yet the impossibility of such consequences has not been proved ; and the bare apprehension of the danger is a real evil, attendant on the erection of a mean or high-pressure steam- engine in the neighbourhood of a dwelling-house. To reduce that apprehension as much as possible the following precautions should be adopted. ' 1, Every steam-engine boiler should be furnished with two safety valves, one of them inaccessable to the workman who attends the engine, the other under his command, in order that he may be able to diminish the pressure on it, as occasion may require. If he attempt to overload this valve, it will have no effect, since the steam will find vent through the other, which is out of his reach. The reporter, M. Dupin, suggests in this place, that if any apprehension of danger be entertained, from the possibility of the inaccessable valve becoming fixed by rust, or negligence, it may be obviated, by fixing in the upper part of the boiler two plugs of fusible metal, formed of such an alloy, as to melt ata few degrees above the working temperature of the steam. One of these plugs is to be considerably larger.than the other, and. to be made of a rather less fusible alloy, so that if the steam does not escape with suflicient rapidity on the fusion of the smaller, it may have ample room to fly off, as soon as the larger has given way. The temperature, at which the least temp 1824.] Dr. Torry on Columbite. 359 fusible alloy melts, must of course be considerably below that at which the increased elasticity of the steam would endanger the safety of the boiler. 2. All the boilers should be proved by being submitted, by means of the hydraulic press, to four or five times the working pressure, for engines that work with a pressure of from two to four atmospheres. Beyond that term the proof pressure should as much exceed the working pressure, as the latter exceeds the simple pressure of the atmosphere. _ 3. Every steam-engine maker should be obliged to make known his method of proving the boilers, as well as whatever may guarantee the solidity and safety of his engines, especially as regards the boiler and its apperidages. He should also des clare this working pressure, estimated by the number of atmo- spheres, or in pounds, on each square inch of surface exposed to the action of the steam. 4. For further security, the boilers of very powerful engines, when near a dwelling-house, may be surrounded by a thick wall, at the distance of between three and four feet from the boiler, and at least as far from the party wall of the adjoining house. Lastly, if an exact account were taken, and published by the proper authorities, of all accidents that happen to steam- engines of every kind, mimutely detailing both the causes and effects of such accidents, with the names of the proprietors, and the makers of the engines, it would mainly tend to render unfrequent, though it cannot wholly obviate the evils that may arise from the use of mean and high-pressure engines. ARTICLE IX. An Account of the Columbite of Haddam (Connecticut). By John Torry, MD.* - Tue history of columbium is recorded in almost every work on chemistry and mineralogy, and is familiar to all who have made those sciences their study. Though it is now twenty years since Mr. Hatchett made his interesting discovery, the only North American specimen of columbite known until lately, was the original one in the British Museum, and even the precise locality of that is not known. It is said to have been sent many oa: since by the late Governdr Winthrop, of Connecticut, to ir Hans Sloane, thet? President of the Royal Society; after whose death it was deposited in the Museum, where it. still remains. According to a notice in the eighth volume of the New York Medical Repository, the locality is said to be near a . * Annals of the Lyceum of Natutal History, New York, 360 Dr. Torry on Columbite. [Nov. spring not far from the house of Gov. Winthrop, near New . London. It has, however, been many years sought for without success; and some mineralogists have doubted whether the specimen in the British Museum was found in Connecticut, or in any part of this country ; but that it was a Swedish specimen of tantalite, which had by mistake been labelled as North American. Ina collection of minerals which I sent many years since to Count Trolle Wachtmeister, this distinguished savant informed me, that in one of the specimens from Haddam, containing cymophane, beryl, &c. Prof. Berzelius had detected the tanta- lite, and that it exactly resembled that of finbo, in Sweden. A notice of this discovery I published in the fourth volume of Silli- man’s Journal, but it has been overlooked by Cleaveland in the second edition of his excellent work, and also by Phillips, in the last edition of his Mineralogy. As soon as I received this inte- resting information, I carefully examined the one or two speci- mens of the Haddam rock remaining in my possession ; but without finding the substance which I supposed Berzelius alluded to; and since that time until lately, 1 had made no other search forit. A few weeks since, however, in examining some splendid specimens of the above-mentioned remarkable rock, presented to me by Col. Gibbs, I observed, disseminated through one of them, several small masses of a blackish substance, hav- ing the appearance of an ore of manganese. On a more atten- tive examination, it presented some unusual characters, and at length I discovered a considerable number of minute crystals, which were evidently of the same mineral with the masses. It occurred to me that this was the tantalite of Berzelius, and a chemical examination of the small portion of the mineral which I could sacrifice for this purpose, left little doubt on the subject. The following is a more particular description of the mineral. It occurs m small amorphous masses, and in minute crystals, disseminated in a granitic aggregate, consisting of quartz, albite,* talc, friable manganesian garnet, beryl, cymophane, Xe. The amorphous masses, which are probably very imperfect crys- tals, are from one-fourth to half an inch in diameter, of a greyish black colour, with the surface always more or less irised. It is opaque. Its structure is imperfectly foliated. Its fracture is somewhat conchoidal. It is not magnetic, either before or after being heated by charcoal. It is sufficiently hard to seratch glass, but not to strike fire with steel. The powder of the mineral is very dark brown. Specific gravity 5°90. Before the blowpipe, it is nearly infusible, the smallest fragment being * Cleayelandite of H. J. Brooke, Esq. as proposed in the last edition of Phillips’s Mineralogy. Itis a subject of regret that this name must be given up for that of albite, the latter having been several years since proposed by Hisinger and Berzelius for these varieties of feldspar having a base of soda, 1824.] Dr. Torry on Coiumbite. 361 slightly rounded on the edges. Borax dissolves it very slowly, forming a pale yellowish glass. The crystals are very minute, being seldom greater in diameter than a common pin, and often much less ; yet many are extremely perfect. The greater num- ber of these crystals is imbedded in the singular friable garnet, which Mr. Seybert has ascertained to contain 30 per cent. of manganese. In one instance, I found them long, very slender, and disposed in a radiating manner. They are often grouped, or intersecting, and are very brittle. The form of the crystal is that of a compressed rectangular prism, usually truncated on the lateral edges, or a four-sided pyramid, two sides of which are, in most instances, unduly extended. According to Phillips, the primary form of the columbite is a right rectangular prism. The annexed figures represent two of the crystals with the measure- ment of the angles taken with the reflecting goniometer. No. 1 is the most common. This, it will be seen, much resembles a figure of columbite in the third edition of Phillips’s Mineralogy, except in some minor truncations. Fig. 1. Fig. 2. PromMy ior T. secede 90600 NoneD 533 UR 90 00 T on di orM on d3.. 157. 00 T on d2 or M on a2... 129 +50 Pid dai BON IS 102" 50 A small quantity of the powdered mineral was fused with six: parts of potash and one cf borax. A mass of a deep green colour was obtained. Muriatic acid poured on this left a white: powder, which, from the small quantity of the ore operated upon, could not be particularly examined, but it appeared to be oxide: of columbium. The muriatic solution was found to contain iron and manganese. I regret exceedingly not having a suffi- cient quantity of the mineral to make a complete analysis, but its external characters, crystalline form, and the few chemical experiments I have made, together with the great probability of the substance I examined being the same alluded to by Berze- lius, leave little doubt that it is columbite. Still, I hope, by examining a considerable number of specimens, to find a suff- cient quantity of the ore to undertake a detailed analysis. If I am correct in my determination of the Haddam mineral, we have a clue, perhaps, to the discovery of the long-lost colum- 362 Copper Sheathing. [Nov. bite. ' The original specimen is said to have been found in New London, which place is not more than 26 miles from Haddam. It is true that the largest piece of ore yet seen from the latter locality, does not much exceed half an inch in diameter, while that in the’ British Museum is said to weigh several ounces; * but itis reasonable to expect, that when the new locality is tho» roughly explored, masses of considerable size will be discovered. There is another circumstance which favours the opinion that the mineral analyzed by Mr. Hatchett is of the same variety, and from the same locality, as that of Haddam, which is, the specific gravity of the latter. The North American columbite was found by Dr. Wollaston to be much. lighter than that of Sweden; the cause of which was supposed to be small cavities in the former ; and in confirmation of this opinion, | would mention that the Haddam columbite, when immersed in water, continued to give out minute bubbles of air for a considerable time, after which the specific gravity was much increased. ARTICLE *X. On the Misstatements in the Morning Chronicle and Times News- papers respecting Sir Humphry Davy’s Method of protecting the Copper Sheathing of Sktps’ Bottoms. In my answer to an attack on the originality of Sir Humphry Davy’s plan for defending the eopper sheathing of ‘ships,} I have said that the defended metal is more liable to become foul from the adhesion of weeds, barnacles, &c. than the undefended. Such a statement first appeared in a provincial paper about June or July last, and was copied into some of the London daily prints, but I cannot now recollect the names of either the one or the other, a circumstance, however, of no consequence to my present purpose. The fact was stated in positive terms, and I, was informed by what I believed to be good authority, that it was correct. 1 was the less anxious to inquire more particularly into it, because, even if true to the full extent, I felt convinced that Sir Humphry Davy would find no diiiiculty in obviating the evil, by reducing the energy of the defensive action; and my conviction on that head remains unshaken. Had my inquiries,. however, been more minute, I should have been more guarded. in admitting the fact.as a general result; for I have since learned that the assertion requires much qualification to make it consist- ent with trath. I do not know whether or not the passage in question has, * Tt weighs exactly 302°46 grains. —C. + Annals of Philosophy, vol. viit. (New Series) p, 14}. * ; , ie ; | i Ny ri 4) eS | h 1824.] Copper Sheathing. 363 given rise to several erroneous statements which have lately appeared in some of the London papers ; but the subject having been revived, and as it appears to me m no very laudable spirit, Iam anxious at least to do away any false impressions that I may have unintentionally occasioned, by putting our readers in possession of such facts as have recently come to my knowledge, and on the accuracy of which they may rely. _ But, first, a word or two as to the newspaper assertions, In the Morning Chronicle of Oct. 10, an extract is given from a weekly publication, called “‘ The Chemist,” which, after deny- ing to Sir Humphry the merit of originality, concludes; “There is, however, a more serious objection to the method proposed. Té has been tried, and it has failed.” This is a short way of settling the question at all events, and when we are indifferent whether the decision be just or not, is, perhaps, as good as any other. Pretty much to the same purpose, and perfectly in the same spirit, is an article in the Times newspaper, Oct. 16, on the same subject. After stating Mr. Muscheti’s experiments, it speaks thus of Sir Humphry’s:—“ The experiment so far suc- ceeded as to protect the copper from decay, but it was soon found out that vessels covered on this plan have returned after short voyages perfectly foul; their bottoms covered with sea weeds, barnacles, and other worms. The remedy, therefore, is worse than the disease.” A little further, we have another therefore. ‘‘ The learned President’s experiments may, therefore, be regarded as a failure, so far as advantage to navigation is concerned, however useful they may be to chemical science, and however pleasant they may have been to himself in procur- ing a summer excursion at the public expense to the North Sea and the Baltic.” Whether these and similar attempts to prejudice the public mind against an invention which there is every reason to believe will afford an effectual remedy for a serious national evil, are to be attributed to sheer ignorance, or a less venial origin, | know not; but whatever bears the impress of superior intelligence, is sure to provoke the spleen of invidious sciolism. It was so with another important discovery of Sir Humphry Davy’s, for even the precious boon of safety to thousands could not protect his Lamp from the sneers of certain petty cavillers. Posterity will be more just ! But to the facts, and by their evidence let our readers judge of the accuracy and justice of the newspaper statements, and the bold assertion, that the experiments have failed. The two harbour boats which gave rise to the original exag- gerated account, were purposely over defended by a surface of zine in the proportion of about 1-25th of that of the copper, the object of those preliminary experiments being solely to ascertain the efficacy of the plan as a preservative of the copper, without 364 Copper Sheathing. [Nov. reference to any ulterior effects. These boats were stationed in Portsmouth Harbour, and the copper remained bright for nearly three months, when it became coated with carbonate of lime, to the rough surface of which, the conferve, always floating in the summer months in Portsmouth Harbour, adhered, and these soon caught other weeds ; but they were all /oose, and there were neither barnacles, nor any other shellfish, nor any worms, amongst them; and it is more than probable, that the same weeds would have adhered even to carbonate of copper. Except in harbour, there is every reason to think that carbo- nate of lime could not adhere to the copper, even with excess of protection, and the conferve: must have been washed off in a ship at sea. Copper, until it is worn in holes, corrodes so fast that no permanent surface remains to which weeds can adhere; but when there are inequalities in the surface, they adhere readily enough even to the poisonous oxide of copper. 1 do not believe that any of the protectors placed upon s/zps are in such excess as to occasion any deposit, and if they are a little posi- tive, or nearly in equilibrio, the whole surface remains smooth, and the adhesion of weed and shell-fish is prevented. As far as the experiments hitherto made enable one to judge, the requisite proportion of protecting surface to that of the copper is somewhere between --1, and ~1,, but even 1, willsave more than half the copper of the navy. In reply to the assertion that protected ships have returned after short voyages perfectly foul, and the delicate insinuation that Sir Humphry Davy has been amusing himself by a voyage to the Baltic at the public expense, I subjoin the following note to the Seeretary to the Admiralty, and his answer. = MY DEAR SIR, British Museum, Oct. 22, 1824. You have seen, no doubt, a paragraph in the Times newspaper of the 16th instant, stating “ that vessels coppered on Sir Hum~ phry Davy’s plan with protectors have returned after short voyages perfectly foul.” in the same paragraph, it is also insinuated, that Sir H. D.’s late voyage to the Baltic was made at the public expense. Pray allow me to ask you if these state- ments, or either of them, be correct or otherwise ? I am, my dear Sir, your faithful servant, J.G, CHILDREN. John Barrow, Esq. &c. &c. &c. Admiralty. i MY DEAR SIR, Admiralty, Oct. 22, 1824. th answer to your inquiries respecting vessels coppered on Sir Humphry Davy’s plan with protectors having returned after short voyages perfectly foul; and whether Sir Humphry Dey . My hing y, a os asta wibltangl apse Sos tans = SRE yee, ere ee ae ae ew | Fig.1 Beachy Hout Howtings Aldingtor | Gatk Firestone Bull Rock Gault, (Claus ot the widercti? / Green Sand ater apis Cowlease © Weald Gay Hastings Sands Beds below the Sands Brook: leslie Section at Swanage Bay “reversed / Fig. 3. f ‘ fo Hii LE Fig. 6. : ie Worbarrow Bay \ Dundle ove 7 Mile Scale of Miles 2 1824.] Dr. Litton on the Strata below the Chalk, &c. 365 made a voyage to the Baltic at the public expense, I have to state, that with regard to the former, no report whatever has been received at this office from any one vessel supplied wiih protectors, nor am I aware that any one of them has returned into port. And with regard to the second point, I can safely say, that Sir Hum- phry’s passage to the Raze of Norway (not to the Baltic), was not attended with any expense either to this or any other department of government. The fact is simply this:—the Comet steam vessel having been ordered to proceed to Heligoland at the express request of the King of Denmark, for the purpose of fixing with precision, by means of numerous chronometers, the longitude of that island, in order to connect the Danish with the British survey; and the Board of Longitude having recommended that the voyage should be extended as far as the Raze of Nor- way, for the purpose of ascertaining the longitude of that important point, Sir Humphry Davy volunteered to proceed in her, at his own expense, to enable him to attend in person to certain experiments which he was desirous of making on the action of sea water on the copper of a vessel passing rapidly through that medium. If any illiberal construction should have been conveyed to the public, as your note would seem to imply, you are at liberty to make use of this reply in any way you may deem fit. I am, my dear Sir, very sincerely yours, Joun Barrow. J. G. Children, Esq. Verbum non amplius addam. J.G. C. ArticLE XI. Inquiries respecting the Geological Relations of the Beds between ihe Chalk and the Purbeck Limestone tn the South- east of England. By William Henry Fitton, MD. FRS. MGS. &c. (With a Plate.) I. Tue geological relations of the beds of sand and clay which are interposed between the chalk and the Purbeck limestone have been of late the subject of considerable discussion ; and various opinions have been formed respecting the difference of structure supposed to exist in the two principal tracts, where this part of the British series of strata is visible upon the coast, namely the southern shore of the Isle of Wight, and the space getween the chalk cliffs near Folkestone and at Beachy Head. Nothing can more strongly show the necessity of further in- ation upon this subject, than the discrepancy in the mts of these two districts, and the general obscurity of all 366 Dy. Fitton on the Strata [Nov, that relates to the beds between the chalk and the Purbeck lime- stone, in the “ Outlines” of Messrs. Conybeare and Phillips; a work so very remarkable for the judgment and success with which its multifarious contents have been brought together and ren- dered consistent. In the account of the wealds of Kent and Sus- sex, described for the first time by Mr. Conybeare in that pub- lication, the tract between the chalk and the Hastings sands is said to be occupied by aridge composed of ‘Green sand,’ quite distinct from the ‘ Iron sands’ of Hastings, and separated from them by a well-marked valley, containing the ‘ Weald’ clay. But in. the description of the Isle of Wight,+ the very same denomina- tions are applied to strata entirely different; the author adopt- ing the arrangement of Mr. Webster, and regarding the lower part of that island as composed of one series only of ferruginous sands, which he identifies with those of Hastings: so that, the reader of the descriptions afterwards given of other parts of England, in which these sands and clays occur, must connect with those terms a different meaning, according to the dis- trict which he may happen to have first seen, or may adopt as the type of his comparison. Mr. Conybeare indeed has himself admitted the obscurity in which this part of the British series of strata is involved; and has ascribed it, not merely to the. imperfect state of our information, which seems to me to be the true cause, but to a greater variation of structure and composi- tion in these beds, when occurring in different quarters, than has been observed in other members of the series,—or than will, I believe, be found in reality to exist. The standard publication to which Mr. Conybeare and all other geologists have referred, in treating of the Isle of Wight, is the weil known letters of Mr. Webster to Sir Henry Engle- field,t{—a work which has given to that instructive district an almost classical celebrity, and has contributed most essentially to the recent.progress of geology in this country. It seems to me, however, from what [ have recently seen, that Mr. Webster’s arrangement of the lower strata of the Isie of Wight has been adopted without sufficient examination ; for though he has iden- fied in a general manner the sands of Hastings and Tunbridge Wells with his ferruginous sands, and stated that the weald clay belongs to this formation, and has also mentioned grit stone as occurring in it, he does not appear to me to have duly appre- ciated the relations of the different members of this part of the series; having overlooked the important natural features re- sulting from the presence and situation of the weald clay, and mentioned the Purbeck beds as constituting the lowest strata of the Island. From a paper recently presented to the Geological Society by Mr. Webster, an abstract of which has been pub- * Outlines of the Geology of England and Wales, p. 144, &c. A + Page 135. $ London. 4to. 1816. “ee 1824.] below the Chalk, &c. 367 lished in The Annals of Philosophy,* it would also appear that he is of the same opinion with Mr. Conybeare as to the want of continuity and correspondence of those formations in dif- ferent quarters; for he states that the siliceous limestone of Hastings had not been noticed in any other place, and describes it as not being coextensive with the rest of the ferruginous sand. It is unnecessary to enter further into the history of this sub- ject, as the subjoined list enumerates the principal authors who have published any thing relating to it, and will show the con- nexion of their several arrangements. But I should hardly have ventured to differ from such authorities, if the structure of those tracts in Kent and Sussex which are composed of the beds under consideration were not obscure; and if, also, it did not appear from Mr. Webster’s own account, that the portion of the Isle of Wight to which my observations relate, had compara- tively escaped his notice ;} since it is not possible to examine the country which he has more particularly described, without admiring the fidelity of his observations, and admitting the general soundness of the inferences he has deduced from them. II. The fact is, that there exist, in the isle of Wight, as in the wealds of Kent and Sussex,—besides the beds of greenish sand- stone immediately beneath the chaik,—two distinct series of sands which differ from each other considerably in composition; and that the features of the surface also correspond with the geo- logical division of the strata, although local circumstances have rendered this connexion less conspicuous in the Isle of Wight than in the wealds of Kent and Sussex. Both of these sands are separated from the beds above them to which Mr. Webster has confined the denomination of green sand, by a stratum of blue clay; and the two sands themselves are again distinetly separated by a second stratum of clay, precisely corresponding, both in situation, and in the fossils which it contains, with the weald clay of Kent and Sussex. It is the inferior of these sands alone which is the equivalent of the Hastings beds; and these constitute the lowest formation visible in the Isle of Wight: the true Purbeck beds not appearing at all upon the coast, nor, I have reason to believe, any where in the interior of the island. * July, 1824, seep. 67 of the present volume. + See Letter, pp. 148, 154. &c. The sources of misconception upon this. subject have not improbably been, the confused state of the lower beds at Sandown Bay, where Mr. Webster began his observations in the Isle of Wight, and the strong resemblance of some of the beds which there occur in the weald clay to the Purbeck limestone ; by these circumstances, Mr. Webster, and, perhaps, subsequent observers, have been misled as to the true relations of the lowest strata of the island, and prevented from examining _ other parts of the coast where they are better displayed. 368 Dr. Fitton on the Strata [Nov. The annexed map and section (Plate XXXII], fig. 2,*) will show the relative situation of the strata, and will explain the circumstances which render the exterior of the low country, at the back of the Isle of Wight, somewhat different in appearance from that of Kent and Sussex, which it really does resemble. The ridge of vertical chalk strata which traverses the whole of the Island from east to west, is succeeded on the south by a parallel range of low hills, consisting of sand, and separated from the chalk by a narrow valley occupied by blue clay: this lower range resembles both in composition and relative place, that which occurs between the chalk hills and the Hastings sands, throughout the greater part of Kent and Surry; and near the coast of the island, itis succeeded by a still lower tract, denoting the situation of the weald clay—from beneath which, as in Sus- sex, the Hastings-sands rise distinctly near Brook Ledge, and also, but less obviously, in Sandown Bay. If, where the chalk recurs in the south of the island, its inclination had been similar to that of the central beds, we should probably have had between the two chalk ranges a parallel ridge of iron sand, with a succes- sion on both sides of similar beds in the same order; and the section of the coast at the back of the Isle of Wight, both on the south-west, from Compton Bay to Rocken End, and on the south-east from Chine Head to Culver, would have corresponded exactly to that of the shore between the cliffs of Dover and Beachy Head. (Fig. 1.) But the southern platform of chalk being nearly horizontal,—its distance from the central ridge inconsiderable, and the outcrop of the two ranges not parallel but converging towards the interior, the beds of sand which come from beneath it, meet the corresponding strata which rise from under the central chalk, so as to conceal the lower beds of the series. It is, therefore, only where the streams have cut deeply through the surface, or on the coast, where the upper strata have thinned out, that the Hastings sands can make their appearance; and when they do occur upon the shore, their section exhibits lines of unequal curvature, with the greater inclination, on both sides, next to the central ridge of chalk. In looking westward from the heights above Rocken-End, the structure now described is plainly discernible :—the Green sand thins off gradually to Atherfield Point, but forms in the interior a continuous range of low hills from Walpen Chine to Kingston, on the west of which place are some eminences of sand; and from thence the range of sand hills already men- tioned can be traced without interruption to the shore at Compton Bay. The low country of the weald clay is also seen * This map is reduced from the ordnance survey, cclourcd after Mr. Webster, with the necessary alterations on the coast ; the general relations of the strata being the object, accuracy of local detail has not been attempted, a = pera ts, ALK TO THE Ha s of different Geologists. Names according t Buckland. (Synoptic Table.) ‘¢ Chalk.” ‘¢ Chaik marl.” “¢ Grey chalk.” chalk ;—or taken for the Green| sand, No. 4. In the Isle of Wight, taken for Tetsworth clay, No. 5. ” In other places, regarded as a va- riety of the chalk marl. ‘« Green sand.” In the Isle of Wight; not distin- guished from the Iron sand, No. 6. “ Tetsworth clay.” the Undercliff No. 3, is taken for this bed. } =| | ‘ Tron sand.” add ?In the Isle of Wight, tie clay of i Isle of Wight ; ‘* Green sand.” Me ik In other places a variety of the grey taken for Sedgwick. (Annals, May, 1822.) ~ °° Chalk.” °° Golt.” ee In the Isle of Wight, ‘Green sand.” In Cambridgeshire, “‘ Indurated chalk marl.” eee “ Golt,” Cambridgeshire. In the Isle of Wight, considered as the Tetsworth clay, No. 5. eee eee Seep ) In the Isle of Wight, not dis- tinguished from No. 6. Fossils described as belonging to the Iron sand. 7 Ko sils described as belonging to the Tron sand. a © Tron sand.” i Tron sand supposed to possess | the fossils of No. 4 LIST OF STRATA FROM THE CHALK TO THE HASTINGS SANDS. With the Synonymes of different Geologists. without flints, grey (marly). bluish. Greenish sand and sandstone ; th concretions of chert, and enestone. Firestone, (lay of the undercliff; Wluish, unh to the touch; in the Isle of, Fight, with few fossils lve; green, with numerous ma- i¢ fossils, in the lower part. wy of the Wealis, Slaty clay and stone; with various fossils, prin gully of freshwater (Cypris, Palu- or, Cyrenm, oysters, hones of pies, Kc), Bedsofshelly limestone, dof ironstone. Pyrnitized wood, bel lignite, Huns and sand rock ; frequently muginous; with numerous alter vions of reddish and variegated edy clays, and concretions of Wood, — Iron- mt. Mveshwater shells. Bones foley, and of Saurian anime , as they exist in the Tale of “Wight CHALK, with flints. ferruginous and reddish | Swanage Bay, south of Punfield, iB y Names according to different Geologists. Other places of their occurrence. | Webster. (Letters to Sir H. Englefield.) | Smith. (Maps, sections, &c.) Greenough. (Geological map.) Buckland. (Synoptic Table.) Mantel. (Geology of Sussex.) Conybeare and Phillips. (Outlines of the Geology of England, &c.) -— In the Isle of Wight. “~ In other places. =——-—| — Sedgwick. (Annals, May, 1822.) Bethersden, Kent. Petworth, Sussex. f Punficld, north of Swanage Bay The limestone as probably bi longing to the Purbeck series. C- t“* Oaktree clay,” considered as the same with the Kimmeridge clay. “ Tetsworth clay,” In the Isle of Wight, the clay of the Undercliff No. 3, is taken for this bed. Probably regarded as subordi- nate to the sands. “© Weald clay.” the Tron sand. “ Tron sand Ye Chalk.” ny | Passim fines }1 ts Chalk.” e Chalk.” be Chalk.” bee chatke bcm” te Chalk.” \ © Chalk.” f : on AGG Eastern foot of Beachy Head. Swa- He Chalk marl.’” Ning S Chalk: marl Grey chalk marl.” Oia nage Bay ; footof Ballard-hill, | J Grey chall Golt. Cambridgeshire. Lower part of the |) : A } eT | (Jfailatone, Geol, ** Green sand, at the edge of the OU ohis tt. 4 ” ou - a ie fowieotay oe chalk hills.” —(Table:—Maps || LO CENE SERENE DLIne Ree Hein Part of the “ Chalk marl." In the Isle of Wight, “ Green sand.” SEE RC I Pe PS eensand. f Sussex and Wilts.) =] z a=) ! East foot of Beachy Head eathneloteners : . 7 We yeenis | ye! In other places a variety of the gre Exclusively, ‘* Gree’ a.” - ‘he . c gate, &c. Gand land diveatone’’) (Sect zg n other places a variety ie grey }Exclusively, ‘* Green sand, s oe E sitakens f © Vecar e¢ Shfcre; near Guildford (Geol. Trans. v. p. 353.) (ie andan ts BHsttecN cee [3 chalk ;—or taken for the Green | Probably the ‘ Malm rock” of | BSornstimes| appears to oa ake foe) EA Cen at ge he ag cara Metin Eine Ts Ee aiweniy etalk ickrestone meee ||| sand, No. 4. Western Sussex. (p. 84.) ae : Swanage Bay. b 2 Worbarrow Bay, &c. J Berks.) & J ite se ee ee = 4: g : Cambridgeshire. Gault. ) re - ) : ‘ S¢ In the Isle of Wight, taken for + Te 9 (7 A . Shiere, near Guildford ‘iT durnted “wibarecus Wick earth (Ee nt, F Serr “ Golt,” Cambridgeshire, Nutfield, Surrey, Fs (Strata identified, p. 13.) AWE Peerera ery Nee. | Blue cali ma | considera as the “‘ Weald clay,” | part of the “ Chalk marl.” 5 Folkestone. >“ Blue marl. Ptr aii ” Ma ella 3 SCS No. 5. (Outlines, p.158.), i In the Isle of Wight, considered as Golt brick earth. (Map of || In other pl. ded a va- | | Gol Pp. Beneath Si houses, Sussex cS 2 n other places, regarded as a va. olt. the Tetsworth cla No. 5. bela Sussex, Wilts, Section, &c.) 3 riety of the chalk marl. YaiNOa.oe wanage Bay. Worbarrow Bay \J 5 J = - =|} == = = = sama (IGS Range of hills intermediate between >) ** Sand and sandstone.” (Maps | | & ) ) 4 RAs : the chalk: and the wealds of Kent |] of Sussex and Surrey, &c,) ¢ @ mets In the Isle of Wight, not dis- y 6 a. eo . ‘ 7 7 ; 4 Teen sand, tinguished from No. 6. and Sussex. This bed, almost exclusively, de- “Sand beneath, the Golt brick I Wee G 1.” Part ofthe “Tron sand? < Greenieand? nie NAT) ” U7 ‘ sa “ and. ** Gree! l peti as A a le ip ety ME In the Isle of Wight; not distin. |? Gree" 0% ea any Fossils described as belonging the ‘¢ ferruginous sands. The position correct; but the guished from the Iron sand, No. 6. | to the Iron sand. lower part erroneously stated _ |} to contain the Portland rock. | J J = = ; : “ Tetsworth clay.” i Hythe, Fossils described as belonging to ** Oaktree clay,” Hastings. Winchelsea. Rye, Sussex. Partially included, with Nos. and 5, under thename of fe ruginous sands, The beds not supposed to be continuous or identical different situations. A T- in > | ee *¢ Tron sand.”” ‘* Sand and sandstone beneath the oak tree clay.” > This bed, in some of Mr. Smith's county maps, appears'to be con- founded with No. 4? }** Tron sand.” J ** Tron sand.”* —S——— | > ** Iron sand.” J Part of the ‘ Tron sand.” —————-——_—_—- Exclusively, ** Iron sand,” _ Se Iron sand supposed to possess | the fossils of No. 4. 1824.] below the Chalk, &c, 369 : to form a Continuous valley, from the west of Atherfield rocks through Brixton, and thence to Brook ; and from this depression: the ground rises gradually on all sides to the coast, so as to resemble a portion of a flattened dome. A similar structure, and the same succession of beds, may be seen on the other side of the island, from the heights above Bonchurch, eastward to Culver; but the sands there occupy a much smaller space, and form only an insulated patch, surrounded by the weald clay, which passes into the interior from the shore beneath the village of Sandown, and in returning to the sea divides the cliff, about midway between the fort and Culver, and imme- diately on the west of Red-cliff. The whole of the intermediate tract between the two chalk ranges, from New Church, through Godshill, and theuce to Kingston, is probably occupied by the Green-sand alone,—except perhaps in the deepest places, where the weald clay may appear in the beds of the streams. ; III, The strata then, of which the south of the Isle of Wight consists, are the following :-- Names given by Mr. Webster. Rypohalkili. 6 wd weiwe ss dais Sais ....++ Chalk and chalk marl. 2. Sandstone, with chert, &c. (J%restone) Green sand. 3. Clay (of the undercliff) (Gault) .... Blue marl. 4. Sand,with various fossils (Greensand) 5. Clay (of the wealds and Tetsworth) 6. Sands (of Hastings) the lowest bed mnitheasland (iis. wees 2k wie, & Ferruginous sands. I cannot give a full description of these beds, but the following observations may assist for the purpose of recog- nising them, where the order is less distinct than in the Isle of Wight: more detailed sections, accompanied by specimens, have been laid before the Geological Society. The shells which I shall mention have been named by Mr. Sowerby, who will give figures in his Mineralogical Conchology, of such as have not already appeared. ; . Firestone.—This formation is obviously of such importance as to require a distinct name; and it seems better to adopt that which I have given, than to retain the term green-sand employed _ by Mr, Webster, which has been almost universally appropriated _ to alower stratum; the /restone, of Ryegate &c. exhibiting a sort of average character, between that of the lower part of the Cambridge Clunch, and of the greener beds of the Isle of Wight. The formation in the latter place has been so well de- qeilbed by Mr. Webster, (p. 140.) that I need only mention the importance of extending the list of its fossils, for the purpose of _ more completely distinguishing it from the lower beds of the _ Preen ey | with which it has been frequently confounded, New Series, vox. Vil. 28 . 370 Dr. Fitton on the Strata [Nov. The Firestone holds its place, and is visible every where along the coast of Dorsetshire, as far as Whitenore Point, where the chalk retires from the sea; and it exhibits the same-cha- racters throughout. It can also be traced through the greater part of Sussex and Surry; but in Kent seems gradually to become less conspicuous, and to lose some of its more pro- minent characters as it approaches the sea, on the east of Godstone. There can, I believe, be no doubt of its geological identity with the lower part of the Cambridgeshire Clunch :* The fossils, so far as they are known, are nearly the same in both ;—and they are in both cases different from those of the green-sand, Gault.—Clay of the Underclif—Kither of these denomina- tions for the marly clay, which immediately succeeds the fire- stone, appears preferable to that of b/we marl, which is taken from a character neither constant nor peculiar to this stratum; and all the evidence that I have had an opportunity of examining, is in favour of its identification with the Cambridgeshire gault, and the blue marl of Folkestone; the principal ditterence, which certainly is remarkable, consisting in the great abundance and variety of the fossils at the place last mentioned, and their com- parative rarity inthe clay beneath the Firestone of the Isle of Wight. Mr. Webster has mentioned this peculiarity, and though I searched carefully in various parts of the island, I could not find any of the more characteristic Folkestone shells ; the place of the bed, however, is not only remarkably well defined along the whole southern coast, but is plainly discernible also to the west, as far as Durdle Cove. Its characters in all these places are very uniform: the clay being of a dull bluish grey colour, harsh to the touch, adhering not very strongly to the tongue, and containing numerous minute elittering par- ticles, which have been taken for mica, but which | believe are more frequently crystalline plates of gypsum,—distinct crystals of that substance being found in it in great abundance, originating probably in the decomposition of the pyrites,+ which it every where contains. It effervesces strongly with acids, and besides the shells, which (in the Isle of Wight) are dispersed through it in small numbers, frequently exhibits traces of slender cylin- drical ramifications, probably derived from organized bodies. The fossils which | succeeded in preserving (for in general they are very fragile), are the following : * See Hailstone and Warburton, Geol. Trans. vol. iil. pp. 248—250. + The specimens, however, have been generally taken in places where the clay has been long exposed to the action of air and moisture: its characters may be different when freshly opened, at considerable depths from the surface. Mr. Aikin has informed me, that at the Highgate Tunnel, the london clay when fresh dug out was uniform, soft, and saponaceous to the touch, not containing any crystalline particles; but after ex- posure for a few weeks to the air, the surface was found to be covered more or less with small rhomboidal crystals of gypsum. EOE eee —n EE Ln i Oe 1824.] below the Chalk, &€. 371 Mya mandibula.—(Min. Conch. Plate 43.) Corbula pisum ?—(Ibid. Plate 209, fig. 4.) A thin shelled bivalve : perhaps a pecten. A very thin shelled ammonite. Scales and bones of a fish. The Gault has, in the Isle of Wight, been sometimes con- founded with the weald clay; from which, however, it is distin- guished by several internal characters, and is every where sepa- rated by the stratum next to be described. Green Sand.—This term, although objectionable as being derived from a character, which is not only variable, but in reality does not belong to the greater part of this stratum,—has been adopted so very generally by the geologists of England, that it seems almost necessary to retain it ;—-keeping always in view the great occasional variance between the name, and the true character of what it is intended to signify. Mr, Webster’s description of what he has named ferruginous sands, relates almost exclusively to this stratum; for he has but slightly noticed the inferior (Hastings) sands, and considers the intervening clay as of subordinate importance: with these ex- ceptions, his descriptions are very instructive. The upper part of the series is principally distinguished by an abundance of ferruginous matter; some of the beds ap- pearing to consist, in a great measure, of particles of brown hematitic iron ore, the surfaces of which are highly polished, mixed with a somewhat coarse quartzy sand. These are especiaily remarkable in the red cliff near Culver, and m the corresponding elevated beds at Compton Chine. Near the top of the formation also, some of the sandy beds are of a very dark colour; probably from an intimate admixture of car- bonaceous matter, for the specimens become whitish on being heated, without any bituminous smell. In the lower portion, calcareous matter occurs in greater quantity ; and though traces of organic bodies, especially of those allied to Alcyonia, occar throughout the formation, it is rincipally from the lower beds that the shells described as Eianainc to it have been procured ; and these beds also parti- cularly abound in green particles. The characters of the whole series are fully displayed on the shore of Sandown Bay; the fer- ruginous portion appearing in the most striking form at Redclitf, and the lower beds on the shore immediately to the east of Shanklin, between the Chine and the Village of Sandown ;— where among the debris fallen from the vertical cliff specimens may be found of almost every variety of green sand, from a cal- careous rock resembling the Kentish rag, to a stone composed almost exclusively of green particles. The upper and more ferruginous beds correspond, I believe, with what is called Car- stone, at Hunstanton, in Norfolk ; and the contrast between the different parts of the formation is conspicuous in various parts of 2B 2 372, Dr, Fitton on the Strata [Nov, Surry and Hampshire:—so that Mr. Conybeare’s description of the green-sand between Leith Hill and Dorking,—where the more ferruginous beds are stated to appear ‘ hike a second formation of iron sand resting upon the green sand,’* is most correctly applicable also in the Isle of Wight. One of the most remarkable of the lower beds of this forma- tion seems to occur at the very bottom of it, and is indeed detached from the superior strata, by a group which forms, as it were, a transition to the weald clay; consisting of greenish grey sand in very thin beds, intimately mixed with a small proportion of clay, and of bluish slaty clay. This detached bed is itself composed of large irregular concretions of greenish sand, with much calcareous matter, and contains numerous petrifactions. It rises about 1000 paces from the chalk in andown Bay, and may be traced upwards in the face of the ruined cliffs on the west of Red cliff. The same fossils abound also on the shore to the east of Shanklin Chine, and ina bed which rises on the west of the central chalk, and may be traced from Walpen Chine to Atherfield Point. It is, proba- bly, from the corresponding part of the series in Surry and Sussex, that a great many of the green sand fossils of those counties will be found to have come: several of the shells found near Ashford, in Kent, and at Parham Park, in Sussex,} being the same with those of the vicinity of Shanklin, &c. ; One feature of this formation, which is very conspicuous on the coast of the Isle of Wight, and might ‘lead into error in situations less favourable for examination, consists in the great variation of aspect and solidity in different portions of the same continuous beds ; one part not unfrequently appearing as avery dark greenish, or almost black, sandy clay; while the very same bed has in other places, where the fracture is recent, a bright reddish and yellowish hue. ‘This appearance has been noticed by Sir H. Englefield and by Mr. Webster, and is ascribed by them, I believe correctly, to the effects of moisture and exposure, on the variable proportion of clay and ferruginous matter which the beds every where seem to contain. The greater part of the fossils assigned to the Iron sand, in Prof. Sedgwick’s valuable paper on the Isle of Wight, belong to the lower part of the green-sand formation.t I have * Outlines, p. 154. + See Mantell, p. 71, &c. t Annals of Philosophy, May, 1822, p. 329, &c. They are as follows :— Cylindrical concretions, probably A palmated cockscomb oyster, from organized bodies, Trigonia dedalea, Stems of the tulip alcyonium, T. aleformis, A compound madrepore, Astarte excavata ? An obscure coralline body, Sphera corrugata, Vermicularia, Terebratula pectita ? Ammonites, Perna aviculiides ? — Rostellaria, Gryphza sinuata. Casts of three or four other univalves, | The other fossils of Prof, Sedgwick’s enumeration belong to the Weald clay. The 1824.] -- below the Chalk, &c. 373 found in it, besides those contained in that list, the follow- ing :— A crustaceous animal, about the size of a small shrimp; near Atherfield, Serpula, two species; from the same place. Corals; probably of different species. | Ostrea Bellovacina? (Min. Conch, Plate 388, figs. 1 and 2.) East of Shanklin. Terrebratula, two species ; Atherfield Point, Gervillia —————? Shanklin. A murex. Another univalye. Weald Clay.—The clay of this formation, both at the top and bottom, seems to be mixed with a considerable portion of sand. Tt contains within it at the upper part an insulated bed of green sand ; and, about an equal distance from the bottom, a bed of sand rock, which may be considered as the forerunner of the Hastings sands: but the central portion is very well charac- terised, and the formation may be traced distinctly in its pro- per place, all along the southern coast of the Isle of Wight: nor does any clay, at all approaching to it in characters or thickness, occur between the Gault and the Purbeck series. The first beds appear to rise on the east of Sandown Bay, about 1000 paces from the junction of the chalk with the firestone beds; the formation occupies a considerable space in the ruined cliffs which succeed the precipice of Red-Clif; but the land-falls at this place render it difficult to trace the beds in continuity, and on the shore below the clay is in general con- cealed by the gravel of the beach :—nor is it again visible till, after giving place to the small portion of the Hastings sands disclosed there, it recurs in the flat space to the west of the fort ; where, at very low tides, beds of clay may be seen upon the shore beneath the inn at Sandown village, sinking to the west- ward under the prolonged cliffs of the green-sand between that place and Shanklin. The clay rises again from beneath the green-sand on the west of Whalé Chine, between Ather- field-high-cliff and Atherfield Rocks,—where the bed of green sand included in the upper part is very distinet, and rich in a great variety of fossils: and from thence for about a mile westward, the clifis afford a most instructive section of the weald clay,—perhaps the best that can be found in England ; moulds of several of these shells (and, perhaps, others) which appear to have been occu- pied by pyrites, occur together, in remarkable ferruginous nodules, which are found in the upper part of the cliff immediately on the west of Shanklin Chine, and in the corre- sponding place within the chine itself. 374 Dr. Fitton on the Strata [Nov. the shore being divided by two considerable ravines, or chines, which greatly favour the examination of it.* The uppermost part of this formation, on the confines of the green sand, consists of bluish-grey sand and clay, in very thin alternating courses, frequently not more than a-tenth of an inch in thickness, or of fine greenish grey, mottled with lighter co- loured sand ; the lighter portion sometimes occupying what ap- pear to be the moulds of minute ramified organic bodies, which exist in great numbers, but are indistinct in all the specimens that I could obtain. These upper beds are, altogether, perhaps thirty or forty feet thick. They are succeeded by the bed already mentioned as the last of the green sand series; and this is immediately followed by a considerable thickness of slaty clay, which varies in hue and consistency, but is in general of a dark bluish grey colour, smooth to the touch, scarcely ad- hering to the tongue, yielding very easily to the nail, and effervescing with acids. The lamine of this clay are coated with the remains of a minute bivalved crustaceous animal, the Cypris faba of Desmarest,+ in vast profusion ; and it contains also various shells. In the clay, there occur subordinate beds of lime’ stone ; { ‘some of which are from five to nine or ten inches in thickness, consisting principally, of bivalves, probably cyrenz,—and con- taining also a small Paludina; one at least of these beds is coated with a thin, somewhat fibrous crust of impure greyish carbonate of lime, approaching that which in a more distinct form occurs between the beds of the Purbeck limestone ;—to which indeed this limestone of the weald bears altogether a very striking resemblance. Another bed of limestone consists almost entirely of a small species of oyster, retaining its shelly lustre. And a third variety must also exist in this formation, either in the form of a bed, or of concretions, though I could obtain only portions of the latter description scattered on the shore ;—but these were numerous, and had evidently come from the immediate neighbourhood: they consist of sparry limestone almost wholly made up of casts of a Paludina, closely resembling the P. vivipara (Sowerby, Min. Conch. Pl. 31), and are scarcely to be distinguisked from some varieties of the Bethersden stone of Kent. This same stone at Sandown Bay contains also casts of the Cypris faba, so abundant in the slaty clay; and I have had since the satisfaction of finding that remarkable fossil in almost all the specimens of Sussex marble, * The state of the weather was so unfavourable, during wy visit to this place, that the following characters have been taken principally from the beds at Sandown Bay. + Hist. Naturelle des Crustacés Fossiles, p. 140, Pl. XI. fig. 8. t This shelly limestone is known in the neighbourhood of Chale Bay by the name of the ‘¢ Platnor stone,” or ‘* Black lake,” or both ; for some of my informants applied the former term to the slaty clay—The resemblance of the calcareous incrus- 1824.] below the Chalk, &c. 375 which I have had an opportunity of seeing :—its occurrence indeed in that of Petworth has been long since mentioned by Mr. Sowerby, in the description of his plate of the Vivipara (Min. Conch. Pl. 31, vol. i. p. 78), though it seems to have escaped attention, as a fossil of this formation. Subordinate to the clays, especially in the lower part of the formation, are also several beds of clay iron stone, some of which contain, disseminated, the same species of cypris as that of the shale, and also in considerable abundance, the casts of a species of Paludina (elongata), which seem to have been filled with pyrites ; one of these beds at Sandown Bay was remarkable in having attached to it irregular concretional masses of a hard calcareous grit, containing numerous casts of a Palu- dina, filled with lamellar sulphate of barytes.* Towards the bottom of the formation, very thin courses of a hard calcareous grit alternates with greyish clay ; and below them is a bed, from ten to twenty feet in thickness, of sand rock or slightly coherent sand, of alight greenish grey colour, butin some places ferrugi- nous, contaiming concretions of grey calcareous grit ; this bed, the forerunner, as it were, of the iron sand, is insulated in the clay,}+ and is followed by thin beds of mottled greenish sand, containing a small proportion of clay, and of blue clay; the whole about forty feet in thickness. And these are finally succeeded by sand rock, containing a large proportion of con- cretional calcareous grit of a greenish hue,—the commencement of what may be considered as the proper Hastings sands; after which no more blue clay appears. The succession of the beds, near Atherfield Point, where they are best displayed, seemed to me to resemble that above de- scribed; and the fossils there were the same with those of Sandown. In Compton Bay, the section is perplexed by a con- siderable subsidence, or perhaps a fault ; which after the first vise of the iron sands, brings down the weald clay again to the shore, so as to produce the appearance of an alternation :— _ but the order of the beds, and the fossils they afford, are still the same. The following are the fossils which I have found in this forma- tion in different places :—The concurrence of the vivipara and cypris, in such great abundance, with several other shells in no tation to the Curl (cr ‘“‘ Cone in Cone”) of Staffordshire, &c. is mentioned by Prof. Sedgewick (Annals of Philosophy, vol. iii. p. 332) 3 and there appears to be a grada- tion, from the indistinctly fibrous incrustations of this place, to the highly crystalline fibrous carbonate of Purbeck. * My attention was directed to this fact, and to the occurrence of the crystals of sul- phate of barytes in the fuller’s earth of the Nutfield green-sand, by Mr. Sowerby.—I have myself a specimen of crystalline sulphate of barytes, with carbonate of lime, from the firestone beds of Worbarrow Bay; so that this mineral appears to be generally, though sparingly, diffused throughout these formations. + It is not impossible that the occurrence of this or similar detached beds of sand rock, within the lower part of the weald clay, may have occasioned obscurity, where the state of the surface prevents their relations from being perceived. 376 Dr. Fitton on the Strata [Nov. small quantity, may tend to supply a geological: desideratum of some importance, by furnishing distinctive characters for the weald clay, which hitherto it has not been easy to recognize in doubtful situations. Cypris faba. (Brongniart and Desmarest. Crustacés, p. 141. pl. xi. fig. 8.)— Hythe — Bethersden.— Petworth.—I. of Wight. _ —Swanage Bay (see hereafter, p. 382). Cardium turgidum? (edge toothed) Min. Conch. pl. 343.— Lf, of Wigikt. — a larger species (edge plicated),— Swanage Bay. Cyrena mecia (a new species).—J. of Wight Swanage Bay. ——— a larger species.—I. of Wight—Swanage Bay. membranacea !—Swanage Bay. Melania attenuata.—Swanage Bay. - tricarinata.—J,. of Wight—Swanage Bay. Paludina elongata.—J. of Wight.—Swanage Bay. — fluviorum. Min. Conch, pi. 31.—_Bethersden—Petworth. —Sandown Bay. Pinna ?—Swanage Bay. Venus ?—Swanage Bay. A short univalve, like a Helix.—J. of Wight. A transversely elongated, almost cylindrical bivalve.-—Swanage Bay. Tooth of a Crocodile.—Swanage Bay. The following are mentioned i Mr. Sedgwick’s paper already referred to :— Ostrea ; an undescribed species, somewhat resembling O. tenera. Min. Conch. pl. 252. fig.2 & 3.—T. of Wight. ‘———— a small flat species?—J. of Wight. The only other place in which the Cyprisis stated to have been found in a fossile state, is in the Department of the Allier, in the south-east of France ; where it occurs in the greatest profu- sion, and is mentioned by Brongniart * as composing almost exclusively the mass of a coarse fresh water limestone—(cal- caire lacustre). In another part of the same district, land and freshwater shells were observed, and veins of fibrous arragonite, but without the cypris: and Mr. Brongniart considers the whole tract as of freshwater origin. The occurrence of a fossil hitherto so rare as the cypris, in such profusion, in counties so distant from each other, is remarkable; and renders it very desirable to determine the geological relations of the strata where it has been found in France. Hastings Sands.—The terms ‘ ferruginous’ and ‘iron sands,’ denote a character that really belongs to the upper portion of the green-sand ; and the former has been applied by Mr. Web- ster to a series which includes three strata at present known to RE BH TEN Ae ee ale IE RENO INTL ER EE NL SES Pe re rasp * Description Geologique des Environs de Paris—Cuvier ossemens fossiles, &c tome ii, Edit. 2%, p. 536, : ag 1824,] below the Chalk, &c. 377 be distinct: It may be advantageous, therefore, to relinquish altogether both of these denominations, and to adopt one from a place where (as at Hastings) the strata are well developed and conspicuous. Names thus derived, do not mislead ; they keep in view and facilitate reference to the original type, and have in fact been adopted for some other strata,—as the Pur- beck, and Portland limestones, the Oxford clay, &c. The Hastings sands in the Isle of Wight may be described as consisting of an alternating series of beds of sand,—more or less abundant in ferruginous matter, and containing courses generally in a concretional form, of calcareous grit,—with beds of clay, much mixed with sand, of a greenish or reddish hue, or of a mottled and variegated appearance. Subordinate beds con- taining or consisting of fuller’s earth, occur along with these clays ;—and wood more or less changed, wood-coal, and iron stone, occur in several parts of the series. in the Isle of Wight apart only of the formation is visible: but at Swanage, a sec- tion of the whole is exposed; and in both cases, the proportion of the clays to the more promiment sandy beds is so great, that if composition only were regarded, the formation ought to take its name from the former. In this respect the sands of Hast- ings differ considerably from the upper part of the green sand series, which contains much less clay ; nor do any of the Hast- ings beds at all resemble those sands at Red Cliff and Compton Bay, which abound so remarkably in particles of iron ore. There is also a more general difference of hue and aspect, be- tween the greater part of the Hastings strata, and the nchly coloured sands in the upper part of the green-sand, which can be recognized, I think, by an eye acquainted with both; but the difference between the fossils of the two formations is for- tunately so great as to afford a much more certain distinc- tion. The section of this formation visible in Sandown Bay, though of small extent, resembles perfectly that of the opposite side of the island, between Cowleaze and Compton-Grange Chines. The prominent land on the west of Southmore, (called, not very correctly, Southmore Point,) is the central part of the series, and the beds thereabouts are the lowest in the island ; the section of them on the shore from Bull-rock to Brook Chine, being a very flat curve, declining on both sides towards the chalk :—but an appearance of greater curvature than really exists is occasioned by the projection of the land, and the gradual rise of the beds from the interior. The principal vari- ation in the features of this part of the coast, is produced by the successive rise of the beds of sand rock with calcareous rit; which, as the clays between are much less durable, orm ledges extending considerably into the sea. It is to the 378 Dr. Fition on the Strata [Nov. superior solidity of these beds,—the bony skeleton as it were of the formation, that its resistance to the denuding furces which have swept away such large portions of the adja- cent clay, must be ascribed, in the wealds of Kent and Sussex, and on a smaller scale in the Isle of Wight.—Thus the bed, called the “ upper sand rock,” which rises very gradually near Cowleaze Chine, may probably have contributed to the support of Atherfield Point; and the successive ledges of Barnes’s sand rock, Ship ledge, the Bull rock (about 20 feet in thickness), and the very remarkable ranges at Brook Point, all owe their promi- nence and solidity to a concreted calcareous grit, precisely resembling that of Hastings; at which place also reefs of the same description occur upon the shore. In Swanage Bay four or five reefs, consisting of the same kind of rock, run out from the sands into the sea; and even at Sandown Bay, a few such ledges can be seen at very low tides. The grit is, in all these cases, of the same general character, and is evidently nothing more than sand agglutinated by a cal- careous cement which has crystallized within it; so that in a certain stage of decomposition, a double structure is discern- ible, the masses of stone becoming fissile so as to disclose the original stratification of the sand, while the fresher pieces show the crystalline fracture of carbonate of lime; and in some cases the parallel faces of the crystals distributed through the mass give by reflection the lustre of carbonate of lime, from a surface which, in other positions, appears to be composed of grains of sand. In the Isle of Wight, the varieties of grit are numerous, and of various shades of grey inclining to biue and green. They all effervesce with acids: but differ considerably in hardness, probably from variation in the proportion of sili- ceous matter. The only fossils that I have found in the Hastings’ sands and limestones, belonging also to the weald clay. I have added to the following list a few others, from the beds of clay and limestone below the Hastings sands, in Sussex. Ryprisstaoas 2) Ue ek ey Paludina lenta ?—smaller and more pointed than P, flu- VIDEUI is armoreiai sibs oer Gyrend Mietlia sca eon. ts In calcareous grit; between In calcareous grit; at Holling- ton, near Hastings. Cyrena media...... byayai earn Battle and Brightling, Sus- Cyrena, a larger species. .... sex ;—and Brook Bay, Isle of Wight. Remains of fishes. Remains of plants. 1824.) below the Chalk, &c. 879 From the beds below the Hastings’ sands, north-west of Battle, Sussex. Riggers medians... 3 sf.» - 2 +2 A thin elongated pearly bivalve | : In slaty clay between the beds like a compressed muscle. | Ey ee Potamides ventricosus? (M.C. | uw vinBRON near Darvel aly fy Way a3) PRY AT He | zine Vertebra of a crocodile ......J Scales (of a fish?) large, quadrangular, imbricated : in lime stone, from the same place. A comparison even of this short list with that of the green sand fossils, points out a distinction between that formation, and the Hastings sands, which may, perhaps, deserve attention, in the grouping and arrangement of the strata :—the organized productions of the former, so far as we are acquainted with them, being all marine: but of the latter, almost exclusively of fresh- water origin, And in fact if a line be drawn between the green sand andweald clay, the whole series, from thence downward to the Portland limestone, may be regarded as one great suite of fresh- water formations :—with the exception principally of those beds of oysters which occur, in small proportion in the weald clay, and more remarkably about the middle of the Purbeck strata,—~ where a bed, about twelve feet in thickness, well known to the quarry men under the name of “ cinder,” consists almost en- tirely of oysters. The resemblance observable in the Isle of Wight, between some of the beds above the chalk ana some of the Hastings sands, ‘seems tofavour the hypothesis, of the mixed origin, at least, of the latter. The light greenish grey and variegated clay of the two series, are very much alike; and among the fossils some of the most abundant in both are of the genus Paludina. The calcareous grit also is not without a parallel in the superior beds; for the stone of East Cowes quarries, which is there called ‘rage,’ comes very near to some varieties of the Hastings’ grit ;* and among the freshwater shells which it contains is a helix resembling the vivipara.— But, on the other hand, some of the Hastings sand beds are scarcely to be distinguished from those of the new red sand-stone (red marl).—This recurrence of beds of the same character, in parts of the series which we are in the habit of considering as so remote, should never be lost sight off; as affording proof of that uniformity in the ope- ration of the causes which have produced the strata, which the * When I visited this place, the pits in Lord H. Seymour’s grounds had been filled up, but the specimens I found there were sufficient to shew this resemblance.— See Webster: Letters, p. 231. 380 Dr. Fitton on the Strata {Nov. artificial divisions of scientific arrangement not unfrequently keep out of view. ' The Wealds. IV. The coast section between the chalk cliffs near Folke- stone, and Beachy Head, is so much concealed by marshy tracts throughout the portion corresponding to the place of the green sand and weald clay, that the examination of it is difficult and unsatisfactory ; but I have coloured the section (fig. 1), in con- formity with that of the Isle of Wight,—in part from observations of my own, with the hope of suggesting further inquiry ; since there is strong reason to expect, from the perfect correspondence of the interior, that the arrangement of the beds upon the coast also, will prove to be throughout the same. ‘At Beachy Head there is no difficulty, the chalk being there succeeded by, and almost passing into beds of firestone, of inconsiderable thickness, but corresponding to those of Culver, &c. in the Isle of Wight, and of Ryegate, in Surrey :* these are followed by blue clay, harsh to the touch, somewhat sandy, and apparently containing few fossils. From thence to a consi- derable distance eastward, the strata are concealed ; but there can be little doubt that the low sand hills which occur at Lang- ley, and from thence run inland through Arlington, Selmeston, &c. (Mantell, p. 76), in a line nearly parallel to the chalk, belong to the green-sand formation. Mr. Smith’s maps of the interior, and his section from London to Brighton, accord with this identification. The list which he has given of the beds within the denudation of Kent, Sussex, and the adjoining counties, corresponds exactly, though under different names, with that of the section, fig. 1; and the range of “sand and sandstone,” represented in his map of Sussex as passing through Barcombe, is obviously the continu- ation of the sands of Langley above-mentioned. The shore on the east of Beachy Head, nearly to Bexhill, is so low and flat, that the beds can be examined only (under favourable circumstances) at low water; the Hastings sands, however, rise about the latter place, and the upper part abounds with reddish and greenish clays, like those already described as forming so large a part ofthis formationin the Isleof Wight.+ The sands decline to the eastward, and subside about Stone Cliff on the east of Rye, and there again the country becomes difficult of examination; what may be considered as the true coast being separated from the sea by Romney Marsh. But the character- * The firestone at Sea-houses has been generally taken for green-sand, and supposed to represent the ridge between the chalk and iron sand of Kent and Sussex, which begins at Folkestone and Hythe. (Conybeare, Outlines, p. 147). - ++ The cliffs at Hastings have been fully described by Mr. Webster, in a paper read before the Geological Society. See Annals, July, 1824, p. 66 of this volume. 1824.] _ below the Chalk, &c. 381 istic fossils completely identify the limestones of that tract with those of the Isle of Wight; and there can be no doubt as to the place where the formation commences, the Cypris faba being found in the clay immediately beneath the green sandstone, above the town of Hythe. a eae In pursuing the boundaries of the chalk around the great denudation of Kent and Sussex, the same succession of beds can be recognized in several other places.—Thus the description iven by Mr. Mantell, from Mr. J. Hawkins, of the ‘Malm rock’ of Western Sussex, accords with the succession represented in Sections ] and 2. A similar section has been communicated to me by Mr. Lyell, from the village of Shiere, between Dorking and Guilford, on the north western side of the weald district : the following being the order of the beds,—chalk, green sand with calcareous chert (firestone); blue marl (gault) of dark colour, with a few fragments of shells; and ferruginous sand (the upper beds of the green sand).—The section (fig. 1), it will be seen, corresponds essentially with that given by Mr, Web- ster,* and by Mr. Phillips (“ Outlines,” p. 150, &c.) of the tract between Merstham and Nutfield, in Surry—And Mr. War- burton informs me that he has traced the upper ferruginous por- tion of the green-sand eastward,—from Guildford through Red- Hill (Ryegate), River-Head, Seal, Ightham, and Wrotham Heath, to Aylesford, in the neighbourhood of Maidstone. On the east of Godstone however, the structure of the county must still be considered as, in some degree, uncertain, for the following reasons: ]. That the firestone beds have not been traced to the west of the point above-mentioned ; though their equivalent will probably be found among the harder beds at the bottom of the grey marly chalk. 2. Notwithstanding the many evidences of correspondence,—the great abundance of fossils in the Folkestone marl, and their comparative scarcity throughout the Isle of Wight, is a variation of such amount as to demand the strongest evidence of geological identity.+ 3. The ferrugin- ous beds at the top of the green-sand formation, have not yet been observed in the vicinity of Folkestone ; while on the other hand, calcareous matter exists there in much greater propor- tion than in any part of the lower beds in the Isle of Wight :— The fossils; however, are the same. But I have observed some appearances on the shore between Sandgate and Folkestone, * Geol. Trans. vol. v. p. 353. + On the opposite coast of France, the Folkestone marl occurs beneath the chalk without the intervention of the fire stone, at least in a prominent form. I have traced it with most of the characteristic shells of Folkestone, all round the denudation of the lower Boulonnois, from the foot of Blanenez, through Boursin, Colemberq, Lottin- ghen, &c. to the vicinity of Samer ; and have found in several places beneath it traces of green sand.—In Mr. Smith’s maps of Kent and Surry, the gault is continued, without interruption, from the west of Dorking to the coast. 382 Dr. Fitton on the Strata [Nov. which seemed to render this part of the series deserving of fur- ther examination. . Coast of Dorsetshire. V. The progressive condensation, and thinning out of the strata towards the west,* is such, that the space occupied by the beds between the chalk and the lowest visible part of the Hast- ings sands,—which is in Sussex (from Folkestone toWinchelsea, fig. 1), more than twenty miles in extent,—is reduced success- ively ;—in the Isle of Wight (between Rocken-End and South- more), to about eight miles ;—at Swanage Bay, fig. 3, to less than one mile and a half;—at Worbarrow, fig. 5, to less than three-quarters of a mile; and finally at Durdle Cove, fig. 6, where these beds appear, for the last time, on the coast, to less than a furlong :—the horizontal distance in a direct line between Folkestone and Durdle Cove, the extreme points of this series, being about 170 miles. This convergence, it is true, appears much greater than it actually is, in consequence of the high in- clination of the strata on the coast to the west of Purbeck, where at last they become very nearly vertical ;+ but the con- densation is really sufficient to make 1t more extraordinary that so many members of the series have been retained, than that some beds should be wanting. At Worbarrow, and in the coves to the west of that place, I could not detect any trace of the weald clay, between the sands below the gault ; the sections (fig. 5 and 6) affording only one continuous series of sandy beds, from the gault to the commence- ment of the Purbeck strata. But at Swanage (fig. 4 and 5) I was more successful, having found there distinctly the equivalent of the weald clay ;—beds of bluish slaty clay containing the cypris faba, and other shells of the same species with those of the Isle of Wight; and limestone in thin strata, composed of bivalves, with small paludine, and of oysters, and in some cases en- crusted with obscurely tibrous carbonate oflime. Beds, also com- posed of mottled greenish-grey sand and grey clay, like those of Sandown and Cowleaze chines, occur in this part of the section.— But the sands interposed between the wealdclay and the Gault are not in themselves distinguishable, at Swanage Bay, from the in- ferior (Hastings) beds; the green particles being wanting, and the sands differing only in colour, fineness of grain, and a vari- able admixture of clay. There are among them some remark- able courses of a very fine grained calcareous grit used by the Swanage quarry-men for sharpening their tools : but I have not * See Webster, Letters, p. 194, and Plates. ++ The difference as to the impression produced on the observer, by beds of the same thickness when nearly horizontal, and when highly inclined,—which arises from our habit of estimating heights and horizontal space by very different scales, deserves the attention of those who are not much accustomed to geological observation. Thus a bed, or group, 200 feet thick, if horizontal, forms a very striking cliff; but as part of an highly in- clined series, it may be passed by with comparatively little notice, 1824.] - below the Chalk, &c. 383 yet had an opportunity of comparing the specimens, with those of the Whetstone quarries at Blackdown, in Devonshire, which are in the green sand. Fig. 3, 1s a section southwards from the chalk near this place to the town of Swanage, but reversed, for the purpose of showing its correspondence with that of the Isle of Wight at Compton Bay: and I have also copied a portion of Mr. Web- ster’s accurate view of the coast, for the purpose of pointing out more precisely the situation of the clays.*—In this sketch (1g. 4) the spectator is supposed to be placed upon the firestone where that bed first rises from under the chalk, and to look along the shore towards Swanage. Masses of fallen chalk are seen between this place and the commencement of the Hastings sands :—but these are easily accounted for,—being in fact an undercliff, produced exactly in the same manner as in the Isle of Wight:—and the firestone and gault rise and hold their place with as much regularity as I have any where else remarked. The section of the Hastings sands, in Swanage Bay, com- prehends the whole of the formation, and gives one of the most distinct views of it that can be obtained in England. It corresponds completely, at the upper part, with the beds which are visible in the isle of Wight, and at Hastings. V1. Very little is yet known of the strata which form the subject of this paper, in the interior of England; but an atten- tive perusal of Mr. Conybeare’s descriptions will show that some of the obscurities connected with them, may be re- solved by referring to the order in which the beds are exhibited in the Isle of Wight. Iam in fact unwilling to abandon the ex- pectation of finding in this part of the series the same steadi- ness of arrangement, that is known to exist in other portions of it: the reasoning which implies, that less of regularity is to be expected in a suite of sands and clays than elsewhere, hay- ing always appeared to me to be insufficient. It is the fact alone, established by extensive observation, that could have rendered credible the identity and constancy of succession of any porlion of the strata; and we really know so very little of the mode in which they have been formed, that our estimate of the comparative probability of regularity in one description of beds, of sand, or clay, or limestone, more than another, is matter of the very slightest conjecture. * The place where all the beds above described occur is called Punfield. ‘The ex- amination of it is rendered difficult by the position of the strata, which retire obliquely inland, and at the same time, when seen from the shore, rise towards the eye; so that the weald clay lies behind the upper beds of the Hastings sand, in a nook, where it is so much obscured by the fall of the incumbent substances, that without the assistance of quarry-men I could not haye obtained a view of the beds in situ. 384 Scientific Notices—Chemistry. [Noyv. ArTICLE NII. SCIENTIFIC NOTICES. CHEMISTRY. 1. Juice of Elder Berries as a Test. Tue juice of the elder berries seems to possess important properties as a delicate reagent. The following process was employed :— Take any quantity of the ripe berries, picked clean from the stalks, and after having bruised them, press the juice into a clean well-tinned vessel. Add a fourth part of its weight of alcohol, and evaporate the mixture to one-half. Remove it from the fire for ten or twelve minutes, and add as much alcohol as you have of concentrated juice. A copious precipitation of the parenchymatous and gummy parts will take place, which will permit the liquor to be strained with ease through a fine cotton cloth. The filtered liquor is now fit for use. It consists of the sac- charine and colouring principles of the berries, in solution with alcohol and water. It is of a beautiful violet colour. In order to ascertain its utility as a test of acids and alkalies, the follow- ing experiments were made :— ; To one pint ofrain water a single drop of the tincture of elder berries was added. The blue colour was too pale to be per- ceived; but the addition ofa single drop of sulphuric acid pro- duced a decided red colour, To the liquor employed in the last experiment, a minute quantity of alkali was added, when it immediately changed to a bright lively green. Ifa quantity barely sufficient to neutralize the acid be employed, the original blue or violet colour -is restored; hence this test possesses all the delicacy of the tinc- ture of litmus, or blue cabbage, and has this additional valuable property of keeping unaltered, during the hottest season of the year. The species tried as above was the Sambucus canadensis; the juice of the common elder berry (Sambucus nigra) will probably answer as well.—(Annals of the Lyceum of Nat. Hist. of New York.) 2. Volatility of the Salts of some of the Vegetable Alkahes, Ferrari states that all the salts of Strychnia, when dissolved in water, are volatile in temperatures below that of boiling water. The volatilization is most considerable when the solution is concentrated, and when it contains an excess of acid. The salts which he examined were the sulphate, muriate, nitrate, and acetate. He remarked also that the muriate ofchinin is so vola~ tile that the steam which rises from its aqueous solution ina ee Je a ee 1824.] Scientific Notices—Chemistry. 385. state of ebullition, has a decidedly bitter taste. The volatility of the sulphate of chinin had been previously taken notice of by Callaud.—(Giornale di Fisica, &c. vi. 457.) 3. Existence of Manna in the Leaves of Celery. Dr. A. Vogel finds the following substances in the leaves of this plant (Apium graveolens). 1, A colourless volatile oil, in which resides the peculiar odour of the plant. 2. A thick fatty oil, partly combined with chlorophyle.* 3. A distinct trace of sulphur. 4. A tremulous jelly, or bassorine, which acquires a gelatinous consistency, by the action of weak acids or of water. 5. A brown extractive matter, soluble in alcohol, and precipi- tated by solutions of tin and lead. 6. Gum. 7. Manna. 8. A very considerable quantity of nitrate of potash. 9. Muriate of potash. The manna may be extracted by boiling the filtered juice of the leaves in order to precipitate the chlorophyle and vegetable albumen, and evaporating the liquid thus purified, to the con- sistency of honey: it separates on cooling in greyish white acicular crystals. Butthe most accurate procedure is to digest this thick liquid for a few minutes in alcohol, and to filter the solution while boiling hot. After some hours it concretes into a soft white coloured mass, resembling a cauliflower : this may be rendered considerably purer by squeezing out the alcoholic liquid, redissolving the solid portion, and crystallizing a second time. Thus obtained, it possesses all the properties of manna purified by solution in alcohol. Like this, it has a sweet taste, is very soluble both in cold and hot water, dissolves but sparingly in cold, and to a large amount in hot alcohol, and on cooling sepa- rates from the solution in the form of a soft white mass, resem- bling a mushroom. The solution also is quite incapable of the spirituous fermentation. The fresh leaves of celery yield rather more than one per cent. of manna, purified by repeated crystallization. He could not succeed in detecting a trace of manna in the leaves of common parsley (Apium Petroselinum), or of the com- mon leek ( A/liwm porrum). This is the first well authenticated instance of manna occur- ring in the leaves of an European plant—(Schweigger and Meinecke’s Jahrbuch der Chemie und Physik, vii. 365.) * This is the name which Pelletier and Caventou have applied to the green colouring matter of leaves, and which would appear from their experiments to be a peculiar vege- i ie gene Journal de Pharmacie, iii. 486.) ew Series, VOL. Vill. 2k % 386 Scientific Notices—Chemistry. (Nov. 4. lodous Acid. Il Sig. Sementini, of Naples, has published an account of a combination of iodine and oxygen, containing less of the latter principle than iodic acid. It is obtained in the following man- ner :—Equal parts of chlorate of potash and iodine are to be triturated together in a glass or porcelain mortar, until the form a very fine pulverulent yellow mass, in which the metallic aspect of the iodine has entirely disappeared. If there be excess of iodine, the mixture will have a lead colour. This mixture is to be put into a retort, the neck being preserved clean, and a receiver is to be attached with a tube passing to the pneumatic trough. Heat isthen to be applied, and for this purpose a spirit lamp will be found sufficient ; at first a few violet vapours rise, but as soon as the chlorate begins to lose oxygen, dense yellow fumes will appear, which will be condensed in the neck of the retort into a yellow liquid, and run in drops into the receiver ; oxygen gas will at the same time come over. When the vapour ceases to rise, the process is finished, and the iodous acid ‘obtained will have the following properties :— Its colour is yellow, its taste acid and astringent, and leaving a burning sensation on the tongue. It is of an oily consistency, and flows with difficulty. Itis heavier than water, sinking in it, It has a particular odour, disagreeable, and something resembling that of euchlorine. It permanently reddens vegetable blues, but does not destroy them as chloric acid does. It is very solu- ble in water and alcohol, producing amber-coloured solutions. It evaporates slowly, and entirely in the air. At 112° Fahr. it volatilizes rapidly, forming the dense vapour before mentioned. It is decomposed by sulphur, disengaging a little heat, and libe- rating violet vapours. Carbon has no action on it at any tem- perature. Solution of sulphurous acid decomposes it as well as 1odic acid, precipitating the iodine as a brown powder. It is characterized by the manner in which potassium and phosphorus ‘act on it: the instant they touch it they inflame ; the potassium producing a white flame and dense vapours, but little or no libe- ation of iodine, and the phosphorus, with a noise as of ebulli- tion, violent vapours appearing at the same time. The odorous nature of this acid, its volatility, colour, and its power of inflaming phosphorus by mere contact, show that some of the principal characters of iodine are retained, and that it is oxygenated, therefore, in a minor degree, and deserves the name -of iodous acid. ~ . . Its composition has not been experimentally ascertained. M. Sementini endeavoured to analyze,it by putting 100 grains -into the end of a long sealed tube, and then dropping a small piece of phosphorus in, iodine was disengaged, and condensed inthe upper part of the tube, and this was found to amount to 45 grains; but this can furnish only very uncertain results. - —— ————— 1824.) Scientific Notices—Chemistry. 387 Iodous acid dissolves iodine, becoming of a deep colour, more dense and tenacious, and having more strongly the odour o iodine. When heated, the iodine partially rises from the iodous acid, but they cannot be separated in this way. « M. Sementini believes also in an oxide of iodine, and has given the name to the black powder, which is produced by the action of sulphurous acid on iodous acid, and which still contains oxy- gen, but he mentions that this and some other points still require investigation. The following are the properties of the iodic and iodous acids, by which a judgment may be formed of their specific difference. Lodic acid is solid, white, without odour, reddening blue colours, and then destroying them. | Volatile at 456° Fahr. with decom- position ; heated with charcoal or sulphur, it is decomposed with detonation. Jodous acid is liquid, yellow, odorous, reddenin blue colours, but not destroying them; volatilizing at 112° Fahr. and even at common temperatures without decomposition; heated with sulphur it is decomposed without detonation, and inflames potassium and phosphorus by mere contact. Bib. Univ. xxv. 119.--(Journal of Science.) wat CaP 5. Inflammation of a Mixture of Oxygen and Hydrogen under >>» Water. tea Every one is acquainted with the oxyhydrogen blowpipe. Mr. Skidmore, of New York, has observed that the luminous jet obtained with that instrument may be introduced under water, without being extinguished. The only precaution necessary is to introduce it slowly, that the flame may not be repelled into the receiver. The flame viewed under water is globular, It burns wood, and heats metallic wires to redness. Mr. Skidmore thinks that his observation may be adyantageously employed in maritime war- fare. . 6. Advantageous Mode of using Alcohol in Vegetable Analysis. MM. H. Petroz and Robinet, in their examination of the fruit of the lilas, treated the decoction of the grains with a large quantity of alcohol gradually added while in the state of a thick a alegre reducing it to a further degree of dryness. By this mode the product of the decoction is at once divided into two portions, one soluble in alcohol, the other not. The decoc~ tion should not be evaporated to a very thick syrup, for in that case the precipitated matter retains some of the substances which should be taken up by the spirit. The alcohol must be of such a strength as not to be too much weakened by the water remaining in the aye Goprnel de Pharmacie.) c 388 Scientific Notices--Mineralogy. [Nov. MINERALOGY. 7. Garnet. To the numerous analyses which have already been published of the individuals belonging to this important class of minerals, we have to add the followmg :— 1. Green trapezoidal garnet from the mine Gamla, in Sala. Silica ..... vevecsoss OOO2 seseee LOS? Cavan Alumina ....... veces 703 000000 10.33 Oxide of iron....... @ DIS Faas Dafoe. ic scked SedeawabodsOQil serie f Magnesia. sc. sserenae i095 enter oe 100-08 2. The same, from the same locality, but obtained at a differ- ent period. SIGE: ajeiniden, nines 04 oie GOLD. aaiee ae 6) bo) ORME. Alumina...seeeseres 278 weeeeeL g.99 Oxide of iron......+. 25°83 nth ( Lime. bia: afb sejaiee eygin nied A Dy dpm blew 9-93 Magnesia. .e.+eeeeee 12°44 ila 99°57 (Bredberg, Kongl. Vet. Acad. Handl. 1822, p. 83.) 3. Calcareous garnet, from Lindbo, in Westmannland. Colour, black and blackish brown. Crystal, the primitive rhom- boid, sometimes with truncated lateral edges. Silica occ. ceeeeees 37°55 «2... 18°78 oxygen Oxide of iron’........ 31:35:09 Janos -werOr6h Lames ie icahete Ce 26°74 eeeeee 8:65 Oxidule of manganese. 4°78 ...... } 100-42 (Hisinger, ibid. 1821.) These three analyses accord sufficiently with the formula which has been deduced as representative of the constitution of garnet; namely, an atom of a silicate of a base containing two atoms of oxygen + an atom of a silicate of a base containing three atoms of oxygen. The mineralogical formula for the Sala garnet is eh rue wpS+R} and for the Lindbo garnet, mets +FS 1824. Scientific Notices— Mineralogy. 389 It is greatly to be wished that this extensive genus were sub- jected to a more systematic examination than it has hitherto received, and as has already been done so successfully in the case of the pyroxenes and amphiboles. The accuracy of the weimee formula is indeed supported by strong arguments ; ut many, particularly of the older analyses, are contradictory of it, and the simplicity of the crystalline form of garnet renders peculiarly necessary a severe induction of facts, before it can be regarded as demonstrated that there are not at present con- founded under this name several genera of minerals, which are essentially distinct from one another, even on the broad basis of the isomorphous theory. 8. On Meionite. Our mineralogical readers are aware that within these few years analyses of this mineral have been successively published by Arfwedson, Gmelin, and Stromeyer. The results of the last two chemists were almost identical; but those of Arfwedson disagreed with both so materially, that it was obvious that either heor they must have beenengaged with a different mineral from meionite. M. Arfwedson, ina letter to Schweigger, acknowledges his mistake, and states, that on repeating the analysis with an authentic specimen, he had obtained results which indicated exactly the same formula with those of Gmelin and Stromeyer. It is singular that the mineral which he originally analyzed, although scarcely differing in composition from leucite, was easily fusible before the blowpipe; whereas leucite is quite infusible-—(Jahrbuch der Chemie und Physik, ix. 347.) 9. Erlanite, anew Mineral. Lustre, feebly shining to dull. Streak shining, with a fatty lustre. Colour, light greenish grey: streak, white. Massive. Sometimes compact, sometimes in small and fine granular dis- tinct concretions. Fracture in some specimens foliated, in others splintery and even. Its structure is distinctly crystalline, but no specimen has yet been observed which admitted of regu- lar cleavages. Hardness, between that of apatite and actyno- lite. Sp. gr. from 3:0 to 3:1. Before the blowpipe, it melts easily into a slightly coloured, transparent, compact pearl, and resembles gehlenite more closely than any other known mineral : from felspar it is distinguished by its greater sp. gr.; from Saussurite, by its inferior sp. gr. and hardness. It was discovered in 1818 by Briethaupt in different parts of the Saxon Erzgebirge. It forms a part of the oldest gneiss formation, and is always mixed with more or less mica. Between Gros-Pohle and Erla there exists a bed of it at least 100 fathoms in thickness. It has been used for upwards of 200 years as a 390 Scientific Notices—Mineralogy. [Nov: flux by the iron smelters, and until its examination by Brie- thaupt, it had been uniformly mistaken for limestone, According to the analysis of Prof. C. G. Gmelin, it is com- posed of SaLIGe: initia Aiwt, dadetieis ie w i sleaisheel bine ANGOIND .cwialindd Oaad ceeieks wbads uate HOt sin dh cidade 0:9 costs aes Halen ae MOUs . aewa decade srsi eis’ slo i: terre: oa ee Magnesia: « 004 «aiesléea «ote hidowtameneelre Oxide -of eG aicioneeces fe ty Qs Oxide of manganese.......++ seth sa NebEe Volatile matter ..... DRS Bt Peo amigo O08 Loss. eeoeoeoaeeresv eevee eaeeee eeeene 1-995 100:000— (Schweigger and Meinecke’s Jahrbuch der Chemie und Physik, vil. 76.) 10. Native Compounds of the Oxides of Uranium and Sulphuric Acid. These new mineral bodies, alluded to by Berzelius, are thus described by Prof. John, their discoverer. (1.) Sulphate of Oxidule of Uranium.—It always occurs crys- tallized, and most commonly in flattened prisms, from one to three lines in length, which are arranged in eccentric druses. Colour, beautiful emerald green, sometimes passing into apple green. Lustre considerable, glassy. Transparent; sometimes, also, opaque and dull. Brittle, and easily pounded. Soluble m water. The solution is precipitated chesnut brown by the triple prussiate of potash, yellowish green by alkalies, and in brown flocks by infusion of nutgalls. Nitrate of silver and metallic iron occasion no alteration; and a solution of barytes precipi- tates a white powder, insoluble in nitric acid. When ignited, it undergoes partial decomposition ; for if, after this treatment, it be digested in water, a yellow coloured powder remains undis- solved. It accompanies the following mineral, which had here- tofore been erroneously regarded as an oxide of uranium. (2.) Subsulphate of Oxide of Uranium.—It forms a thin, botryoidal, intense sulphur-yellow coloured coating over the surface of the minerals on which it is found. It is friable, and soils the fingers. Digested in water, a portion of it passes into solution. The residue dissolves in nitric acid; and both solu- tions possess the properties of a solution of sulphate of oxide of uranium. Both minerals occur in Elias’s mine, at the distance of about a league from Joachimsthal, in Bohemia. ‘The examination of these compounds, observes Dr. John, 1824.] Scientific Nottces— Mineralogy. 391. affords a new proof of the superiority of the chemical over the external characters of minerals, for many other ores, as, for, example, those which are usually styled nickel ochre, zinc ochre, black copper, most of the oxides of manganese, Xc. are in a similar situation, not one of them being pure oxides.—(Schweig- ger and Meinecke’s Jahrbuch der Chemie und Physik, ii. 245.) 11. Notice of the Lenzinite from the Neighbourhood of Saint- Sever. This mineral differs extremely in its appearance; it is most commonly met with in amorphous masses, from the size of the fist to that of the head: it is much lighter than limestone, and covered externally with a yellowish brown coating of oxide of iron. Internally, it is ofa fine dead white, opaque, homogene- ous, compact; of a fine grain, and soft and soapy to the touch; it is susceptible of being polished by rubbing with the finger. It adheres strongly to the tongue, and may be cut with the knife; but is sufficiently brittle to break under the hammer into sharp angular pieces. Its fracture is dull, and often conchoidal. When dipped in water, and then held near the ear, it crackles remarkably, but does not split, like the argzllaceous lenzinite of John. It gives no effervescence with acids, becomes hardened by fire, but not sufficiently so, to scratch glass. According to Pelletier’s analysis, it consists of Tica ED ae eee ian a0 Pei 2 EY On) a ae Mater ein Sg Fe ED ASB Spee Woe UPPER ASS SONALI A Ne eee te 100 In its external appearance, it has much resemblance to the compact carbonate of magnesia, M. Leon Dufour describes three varieties of this mineral.— (Annales des Sciences Naturelles.) 12. American Localities of some Minerals. Mr. Shepard has found, what he considers as yenite, at Cum- berland(R.I.); at Chesterfield, fine specimens of green feldspar and siliceous oxide of manganese, containing occasionally small octohedral crystals of magnetic iron. These two were found near the spot where the sappare is obtained. Beautiful green feldspar has been recently found at Beverley (Massachusets), by the Rev, Elias Cornelius; small portions of purple fluor are disseminated in its fissures. ide Mr. Jacob Porter gives the following localities :— Calcareous tufa, exhibiting impressions of vegetables, hasbeen found. at Semphronius, New York. » 392 © Scientific Notices—Mineralogy. [Nov. _ Limpid quartz, in good crystals at Saratoga Springs, and at Sand Lake, New York; and the following chiefly in Massa- chusetts. Blue quartz, ferruginous quartz, fetid quartz, chalcedony, hornstone, grey and red jasper, prismatic mica, black tourmaline in milky quartz, silver-grey scapolite, black hornblende, graphite, and oxide of manganese. Mr. Steuben Taylor found feldspar in large crystals, actyno- lite in potstone, graphic granite, and ferruginous quartz, at Berk- hampstead; black mica and prismatic mica, at Hartford ; radiated quartz, at Canton; kyanite, at Chatham; garnets in mica slate, at Middle Haddam; epidote and gneiss, at Plain- field; galena, at White Creek (N. Y.); smoky quartz, at Kil- lingly ; ferruginous sand in great abundance at Black Island; and green talc, at Smithfield, R. I. To this list we shall add some other localities given by Dr. Emmons. . Siliceo-calcareous oxide of titanium (sphene) in oblique four- sided prisms, of a light brown colour, associated with augite and actynolite, and also in sienite, at Chester. Phosphate of lime, in an aggregate of grey epidote, zoisite, hornblende, and quartz, same place. Manganese, chabasie, stilbite, carbonate of lime, in various forms, at Cummington ; beryl, at Norwich and Chester; in an aggregate of carbonate oflime, chlorite, and feldspar ; prismatic and tabular mica, indicolite? garnets and staurotide, of every variety, in mica slate, Norwich. A .curious variety of cyanite occurs here, in a very fine soft mica slate (resembling potstone), often in hemitrope crystals, colour, greyish blue ; also ferrugi- nous oxide of titanium (nigrine?) in granite, and oxide of tita- nium (titanite ?), in flat plates, in mica slate. Augite abounds here in amorphous masses. Sahlite and coccolite occur in mica slate ; magnetic oxide of iron is abundant in mica slate, serpentine, &c.; rhomb spar is found in dolomite at Middlefield, anda large mass or rock of the rhomb spar of the same place, contains fibrous tremolite. Agate, at Chester, a large mass found near the village, in the sand. It consists of yellow jasper and chalcedony, and weighed upwards of 180 lbs. after several large fragments had been broken off. Another large mass of the same materials, partly agatized, almost twice the size of the preceding, was found near the same place.—(American Journal of Science.) 13. Vesuvian Minerals. (Extract of a Letter from Signor Mon- ticelli.) The torrents of water which followed the eruption of Vesuvius in 1822 exposed several minerals, some of them new, to view. They consist of lapis lazuli, found in the midst of the red sand, 1824.] Scientific Notices— Mineralogy. 393 thrown out on the 24th of October; different varieties of quartz (flint and menilite, and specimens passing from those substances to a lava of amphigene and pyroxene); phosphate of lime in hexahedral prisms; melilite in cubes, similar to those from Capo di Bove (the last two found in a.current (of lava?) on the declivities of Mont Somma, above Pollena); gehlenite, similar to that from Fassa ; specular iron, octohedral oxidulated ‘iron ; antimonial iron and glass of antimony combined with a little osmium.—(Bulletin des Sciences Naturelles.) 14. On the Contractions of Crystals by Heat. M. Mitscherlich has observed that the mutual inclination of the faces of Iceland spar vary in a sensible manner by the effect of heat, and that between 0° and 100° (32° and 212° Fahr.) the change from the dihedral angles to the extremities of the axis of the rhomboid is 81’. It results from this, that if we suppose the dilatation of the crystal perpendicular to its axis to be nothing, its cubic dilatation should still exceed that of glass by nearly one-half; but on measuring the cubic dilatation of Iceland spar with M. Dulong, M. Mitscherlich found, on the contrary, that it is less ; which leads to the smgular consequence, that while heat dilates the crystal in a direction parallel to its axis, it must cause it to contract perpendicularly. M. Mitscherlich has ascertained this to be the fact, by measuring with a spherometer, at different temperatures, the thickness of a plate of Iceland spar, cut in a direction parallel to its axis. It is very probable that sulphate of lime may present an analogous phenomenon, but the reverse of the preceding ; that is, that elevation of tem- perature may produce a sensible contraction in the direction of its axis. 4. [’—(Annales de Chimie.) 15. On the Inclination of the Line dividing the Optical Axes of certain Crystals, It is known that the optical ares of crystals, improperly called crystals with two axes, do not coincide with the axes of crystal- lization; and it has been hitherto regarded as a general law,. that the right lines which divide the angle contained between the optical axes into two equal parts must be equally inclined on the corresponding faces of the crystal. M. Mitscherlich has found that these lines, symmeirical with respect to the double refraction, are uot always so with respect to the faces of the crystal, and that in some salts, such as the sulphate of magnesia, they are more inclined to one side than the other, without any want of symmetry in the crystalline form, leading one to presup- pose any such deviation. A. /’—(Annales de Chimie.) 394 Sctentific Notices—+Geology. ENov; GroLoey. 16. Onthe Accuracy of the Inference that certain Formations have been deposited from Fresh Water, deduced from the Organic Remains found in them. Dr. Mac Culloch, in a very interesting paper, on the Possibi- lity of changing the Residence of certain Fishes, which appeared in the 34th number of the Journal of Science, having shown, that several species of salmon spend a large’portion of their time in fresh water; that the smelt has been familiarised entirely to fresh water, in which it has been kept for three years by Colonel Meynell, in Yorkshire, propagating and thriving abundantly ; that the pike is found in the Caspian Sea; and that many other fishes live and thrive indifferently either in fresh or salt water, concludes with the following judicious observations :— “‘ There is a subsidiary question arising out of these specula- tions respecting the convertibility of the habits of marine ani- mals, highly interesting to geology, and on which it will not be out of place to say a few words, although unfortunately not much solid information can be procured respecting it. This relates to the power which many, perhaps all the vermes inhabiting shells, possess of residing indifferently in salt or fresh water. , It is well known to geologists that with respect to many, if not all of those deposits supposed to have been formed, like that of Paris and of England, under fresh water, the question mainly. rests on this, namely, whether the shells now supposed, from certain analogies and peculiarities of structure, to have been inhabitants of fresh water lakes, may not have equally existed in salt lakes, or even in the sea, Some experiments towards the elucidation of this subject have been instituted in France, but I need not detail them, as they must be fresh in the recol- lection of all the readers of this journal. It has also been recently ascertained by M. Freminville, that in the gulf of Livonia, the shell fish which usually inhabit the sea, and those which belong to fresh waters, are found living together in the same places. While these confirm the general presumption which forms the basis of this communication, their general pro- bability is also strengthened by that analogy. A few facts of common occurrence on our own shores seem to add additional weight to the opinion that the testaceous fishes in general are not rigidly limited to one kind of water, but are capable of living in both. “On our sea coasts, the common muscle is invariably larger and fatter at the entrance of fresh water streams into the sea, particularly if these bring down mud, and in these places the water is scarcely salt; yet they live also and propagate in abun- dance on shores which receive no fresh water. The oyster is | 1824.] Scientific Notices—Miscellaneous. 395 transported from the sea to brackish water, where it also not only lives, but improves in condition. “In the same manner the common cockle inhabits indiffer- ently the muddy sand-banks near the estuaries of rivers, which are always soaked with fresh water, and those sandy or half muddy shores where no such water is found. These are by no means the whole of the instances which might be enumerated in support of an opinion, of which the determination is so important in the present state of geological science ; but as this subject is too important to pass lightly over, and as the bounds of this communication are already exceeded, I shall leave it to those who may have the means and the inclination to examine it in greater detail. I will only add, that the same considerations will lead to similar doubts, where it has been attempted by geologists to determine the nature of strata, as to their marine or fresh water origin, by that of the remains of fishes found in them.”—-(Journal of Science.) . . MIscELLANEOUS, 17. Fulminating Powders employed as Priming for Howling Pieces. The fulminating substances which have hitherto been em- ployed for this purpose are four in number. 1. Fulminating sil- ver; 2. Fulminating mercury; 3. A mixture of 100 parts of chlorate of potash, 12 of sulphur, and 10 of charcoal; 4. A mixture of 100 parts of chlorate of potash, 42 of nitre, 36 of sulphur, and 14 of lycopodium. A variety of experiments on their comparative advantages have been recently made in the chemical laboratory in the University of Halle, by Lieut. P. W. Schmidt. The following appear to be the most useful conclu- sions at which he arrived. Fulminating mercury answers the purpose completely, but he does not agree with Mr. Wright in considering it as to fulminating silver. On this point, however, we feel disposed to differ with Mr. S. By his own admission, it never fails to inflame the gunpowder, and as it is not nearly so explosive as fulminating silver, the risk attending its employment must be proportionally less. The first mentioned mixture of chlorate of potash is much preferable to either of the metallic fulminating owders. It is not so liable to accidental explosion; it leaves ehind it less acid matter, and does not corrode the iron so rapidly ; and, contrary to what takes place with fulminating mercury, its explosion is not followed by a deposition of mois- pes: The facility and certainty of the explosion is the same in oth. ‘The second mixture of chlorate of potash is not nearly so effi- cacious as the first; although this is chiefly a consequence of the ordinary construction of the touch-hole, The method of 396 Scientific Notices—Miscellaneous. [Nov. filling the copper caps, recommended by Mr. Wright, is not only tedious but dangerous ; a much preferable one is to mix up the explosive compound into a thick liquid, with any adhesive solu- tion or tincture, and by means of a hair pencil to introduce a large drop of this mixture into the bottom of each cap. The Germans, we suppose by way of practical refutation to the hackneyed reproach of national dulness, have anticipated their neighbours in making a novel application of fulminating powder. A good many years ago, an attempt to murder was made by sending by post to the obnoxious person a box containing a quantity of the powder, and within which several of the common fulminating papers were cemented in such a manner, that they must have exploded on removing the lid. Fortunately, however, although the explosion took place, it did not communicate to the rest of the powder. The criminal was detected, and, after a judicial trial, was suitably punished.—(Schweigger’s Neues Journal fiir Chemie und Physik, xi. 66.) 18, On a new Method of destroying Calcult. Dr. Civiale introduces a straight silver sound into the bladder through the urethra. This first sound incloses a second, also of silver, and straight and hollow like the first, and furnished at its extremity with three spring branches, which lie close. toge- ther whilst ensheathed in the principal sound, but when pushed out they separate and form a sort of cage, in which, with some dexterity on the part of the operator, the stone is caught, when the cage is immediately closed by his drawing the sound towards him. The second sound, in its turn, incloses a long steel cylinder, terminating, at the end next the bladder, and between the jaws of the cage, ina little circular saw, or file, of such form as may be most applicable, according to circumstances. When the stone is well fixed, the steel cylinder is pressed against it, and by means of a small pully fixed at its exterior extremity, a watch- maker’s turn-bench, on which it is mounted, and a drill bow, it is worked like a drill for piercing a hole in a piece of metal. A dull sound is immediately heard proceeding from the abrasion or splintering of the stone. A spontaneous discharge of urine, or an injection of tepid water into the bladder, usually termi- “nates the operation, and occasions the expulsion through the urethra, dilated by the introduction of the large sound, of the fragments of the calculus. This process was first tried before the Commissioners of the Academy on the 13th of last January, on an individual of the name of Gentil, thirty-two years old. On the 3d of February, when the operation was repeated for the third time, the calculus was entirely removed. The pain was almost nothing, and dur- ing the progress of his cure, M. Gentil always went on foot to the house of M. Ciyiale. 1824.] Scientific Notices— Miscellaneous. 397 19. White’s Floating Breakwater. Among the practical and useful inventions of the present day, the floating breakwater of Mr. White, for which he has received a patent, promises to hold a respectable place. This contrivance consists of a series of square frames of tim- ber, connected by mooring chains, or cables, attached to anchors or blocks ; they are disposed so as to inclose either a rectilineal or a curvilineal space for the reception of ships, which may ride there, protected from the breaking of the sea or surf. These frames consist of logs of Quebec yellow pine, from thirty to fifty feet long, and from eighteen to twenty inches thick. The logs are bolted together so as to form a square frame, consisting of two parallel frames. The separate frames are connected by ropes or chain cables, secured to anchors or moving blocks. The height of these frames may be increased by logs, or pieces of timber, on the tops of the frames, not exceeding five tiers in a vertical position, for the purpose of breaking the waves more completely in places where the water is violently agitated. The advantages of this breakwater have been actually expe- rienced at Deal, and certified by some respectable persons of that place. The jnventor recommends it particularly for fishing coasts, where the surge often prevents boats from putting off and land- ing; and also for bathing places, where it will always produce smooth water, and protect the machines. A drawing and more minute description of this invention will be found in Newton’s London Journal of Arts, &c. vol. vii, p. 232.—(Edin. Jour. of Science.) 20. Marobia. The ‘ Marobia” is an extraordinary phenomenon, most pro- bably deriving its name from Mare Ubbriaco, or Drunken Sea, as its movement is apparently very inconsistent. . It occurs princi- pally on the southern coast of Sicily, and is generally found to happen in calm water, but is considered as the certain precursor of a gale. The marobia is felt with the greatest violence at Mazzara, perhaps from the contour of the coast. Its approach is announced by a stillness in the atmosphere, and a lurid sky ; when suddenly the water rises nearly two feet above its usual level, and rushes into the creeks with amazing rapiulity ; but ina few minutes recedes again with equal velocity, disturbing the mud, tearing up the sea weed, and occasioning noisome effluvia: during its continuance the fish float quite helpless on its turbid surface, and are easily taken. These rapid changes (as capri- cious in their nature as those of the Euripus) generally continue from thirty minutes to upwards of two hours ; and are succeeded by a breeze from the southward, which quickly increases to heavy gusts. Smyth’s Memoir of Sicily—(Kdin. Phil. Jour.) 398 New Patents. [Nov. ARTICLE XIII. NEW SCIENTIFIC BOOKS. PREPARING FOR PUBLICATION, Dr. Thomson has in the press a new work, entitled An Attempt to establish the First Principles of Chemistry by Experiment. Dr. Prout is preparing a greatly enlarged edition of his Inquiry into the Nature and Treatment of Calculus. Outlines of a System of Medico-Chirurgical Education, containing Illustrations of the Application of Anatomy, Physiology, and other Sciences to the principal practical points on Medicine and Surgery ; with Plates. By T. Turner, Member of the Royal College of Surgeons of London, Lecturer on Anatomy, &c. Mr. Maund, of Bromsgrove, well known as a practical disciple of Flora, will commence on the Ist of Jan, 1825, a monthly publication, to be entitled, The Botanic Garden, or Magazine of Hardy Flowers; intended as a popular Manual for Botanists and Florists. A Manual of Pharmacy. By T. W. Brande, Esq. 8vo. A Dictionary of the Apparatus and Instruments employed in the various Operations of Philosophical and Experimental Chemistry, is about to be published by a Practical Chemist. JUST PUBLISHED. An Essay on Instinct and on its Physical and Moral Relations, By Thomas Hancock, MD, 8yo. 12s. ATreatise on the Use of the Natural and Fictitious Waters of Carls- bad, Emms, Marienbad, &c. By Dr. F. Kreysig, of Dresden, Part IT, Royal 8vo. 5s. 6d. The Natural History of the Bible. By Thaddeus Mason Harris, DD, of Dorchester, Massachussetts. 8vo. 10s. 6d. Letter on the projected Rail-road between Liverpool and Man- chester. By Joseph Sandars. 1s. ARTICLE XIV. NEW PATENTS. F. H. W. Needham, David-street, Middlesex, for his improved me- thod of casting steel.—Oct. 7. W. Foreman, Bath, Somersetshire, commander in the Royal Navy, for improvements in the construction of steam-engines.—Oct. 7. F. Benecke, Deptford, verdigris manufacturer, and D. T. Shears, and J. H. Shears, Fleet-market, coppersmiths, for improvements in the making, preparing, or producing of spelter or zinc.—Oct. 7. P. Alegre, Commercial-road, Middlesex, engineer, for his economi- cal method of generating steam applicable to steam-engines and other useful purposes.—Oct. 7. H. Jeffreys, Park-street, Bristol, merchant, for his improved flue or chimney for furnaces and other purposes.—-Oct. 7. I on eae ee ve - fh 1824. Mr. Howard’s Meteorological Journal. 399 ARTICLE XV. METEOROLOGICAL TABLE. Te BAROMETER, THERMOMETER, - 1824, | Wind. Max. Min. Max. | Min. | Evap. | Rain. 9th Mon. . Sept. 1|S FE] 30°12 30°11 85 5 = . 2; &E 30°12 50:09 86 54 == 3\IN E| 30:09 30°01 80 64 = 10 4) W 30°01 29°89 75 52 _— 5| W 29°89 20°65 72 55 — 6\S E| 29°66 29°65 72 56 MCh 14 7\IS Wi 29°65 20°54 72 53 _ 105 s| Ss 29:79 29°54 66 48 — 14 9} W 29:92 29:79 66 48 — 34 10\N W)| 29:92 29:81 68 54 — 54 11/55 W\ 29:81 29:76 70 57 _ 32 1255 WI! 3018 29°76 68 48 = 04 13'S W| 3018 30°15 70 52 — 14, S 30°16 $015 72 63 — 03 15S Wj 30°35 30:16 73 53 — 16} N 30°35 30°25 72 55 "75 17| E 30°25 30°17 i 59 — ISIN. E| 30°17 30°05 75 58 — 19} W 30°05 29:98 67 55 —_ 24 20] N 29'98 29°97 63 A5 — 12 21| W 30°15 29:98 60 46 — 02 22IN WI 30°15 30°05 65 53 — 12 Q3IN E| 3013 30°04 65 52 — 24) N 30°13 30°12 66 52 — — 25IN WI 30°13 30'12 60 39 —_ — 26IN WI] 30°12 20°72 50 37 — 17 Q7IN- EE] 29°94 29°67 48 34 — 19 2siN WI 30°04 29°94 52 27 — 29/8 E| 30°04 29°76 61 43 i 30| S 29°76 29°32 70 52 “80 21 —_ —_———_— 30°35 29°32 86 27 232 One The observations in each line of the table apply to a period of twenty-four hours, beginning at 9 A.M. on the day indicated in the first. column, A dash denotes that the result is included in the next following observation. ’ 400 Mr. Howard’s Meteorological Journal. [Nov. 1824. REMARKS. Ninth Month.—], 2. Fine. 3. Cloudy: a few drops of rain at one, p.m,: a shower in the night, 4. Cloudy and fine. 5, Fine. 6. Morning showery: afternoon fine. 7. Showery: very wet night, with thunder and lightning. 8—11. Showery. 12. Showery morning: afternoon fine. 13—I8. Fine. 19. Cloudy. 20. Showery morning: fine afternoon. 21, 22. Cloudy. 23. Fine, 24, 25. Showery. 26. Fine. 27. Showery: aclap of thunder at half-past three, p.m. followed immediately by a heavy shower of hail of the size of peas: rain afterwards with thunder: the quantity of hail was sufficient to cover the ground in places. 28—30. Fine. RESULTS. Winds: N, 3; NE, 4; E,2; SE,3; 8,3; SW,5; W,5; NW, 5. Barometer: Mean height < Rorthel mo onthis yjaip odie eeteieterig's Gehwe ovsing siesta ecu 29-974 inches. For the lunar period, ending the J6th.........-.+++ -- 30°038 For 14 days, ending the 8th (moon south) .........-- 29°986 _ For 13 days, ending the 2]st (moon north)........ -» 30°055 Thermometer : Mean height For the month........ Sep Note walwiste/d ninaigpielp 9.8 sic Gas Oma - For the lunar period. ..........-. cecesnencwccescons O3'300 For 31 days; the sun in Virgo. ...+..sescesseeeeees 62°870 Evaporation... icssccccsccecacecnerscecscceuseretecs casbececeess 2°32 in. Rain atts Ebieiale le ais Wiatpivia cine Gale nid iatew.eneie Sin lori ts laa disaterels welelekye & if fe Laboratory, Stratford, Tenth Month, 22, 1824. R. HOWARD. - ANNALS OF PHILOSOPHY. DECEMBER, 1824, ARTICLE f. Biographical Sketch of the late Rev. E. D. Clarke, LL.D., Professor of Mineralogy in the University of Cambridge, &c. Epwarp Daniet CLarke was born June 5, 1769, at Wil- lingdon, in the county of Sussex, and was descended from a line of ancestors, whose learning and abilities reflected, for a lon series of years, the highest credit upon the literature of their country. The celebrated Dr, William Wotton was his great- grandfather. His grandfather, ‘ mild William Clarke,’ was one of the most accomplished scholars of his age; and his father, the Rev. Edward Clarke, was distinguished in the same honour- able career. fle is represented to have been from his infancy a most amusing and attractive child; and particularly to have exhibited in the narrow sphere of his father’s parish, the same talent for playful conversation and narrative, which ever after- wards distinguished him in the various and extensive circles through which he moved. He showed, when very young, a decided inclination to those objects of science which were the favourite studies of his later years. Having received the rudi- ments of his education at Uckfield, a small town within his father’s parish of Buxted, under Mr. Gerison, who had been his grandfather’s curate, and his father’s preceptor, he was removed, when somewhat more than ten years old, to the grammar-school of Tunbridge, at that time conducted by Dr. Vicesimus Knox. But his progress here was not very satisfactory: his attention appears io have been engrossed by various attractive subjects, some of a scientific nature, which were altogether inimical to his progress in classical literature. In the year 1786, when only sixteen years of age, he obtained, through the kindness of Dr. Beadon, then Master of Jesus College, and now the venerable Bishop of Bath and Wells, the situation of Chapel Clerk in that Society. The three years which Edward Clarke spent in College, before he took his Bachelor’s Degree, present no incidents of life, or New Series, Vou. ViIt. 2D 402 Biographical Sketch of the [Dec. points of character, sufficiently important to occupy a place in this brief memoir ; nor has there been found a single academical composition written by him at. this time, in any department of learning, either in prose or verse, which would be considered worthy of his subsequent fame. Indeed, it is not the least extraordinary circumstance in his history, that this critical period, which generally lays the foundation of other men’s fortunes, aad exercises the greatest influence upon the conduct of their future lives, was by him sufiered to pass, not only without academical honours or distinctions of any kind, but apparently without fix- ing any character whatever upon his literary views; and evidently without even those moderate advantages which a com- mon mind might have derived from it. The loss itself, however, is much more easy to account for, than the singular vigour of mind, with which he afterwards redeemed it. Mathematical studies formed the principal path to College honours and emolu- ments, but for these, unhappily, Edward Clarke had no taste, and therefore made little progress in them; and with respect to classics, in which, as intimated above, he came up with a moderate knowledge, there was nothing at that time, either in the consti- tution or the practice of his College, calculated to encourage a taste already formed for them, much less to create one where nothing of the kind was felt before. Under these circumstances, with a strong literary passion, and at sea, as it were, withouta pilot, upon the great waters of mental speculation, it was natural for him to form his own plans, and to steer his own course, Though he made little progress in the appropriate studies of the place, his literary ardour was not directed to unworthy objects, nor conducted upon a narrow scale. His active mind ranged lightly over a wide and interesting field of literature: history, ancient and modern; medals, antiquities, with all the variety of oe learning which is comprehended under the name of the elles Lettres, shared by turns his attention and his time. But English Poetry was the natural element in which his youthful and ardent imagination delighted to expatiate. To these pur- suits may be added Natural History in some of its branches, particularly Mineralogy; but, as he had few books, and no assistance in these subjects, it was not probable that he could make much progress in them. About the end of the year 1789, he took his degree of Bachelor of Arts, and within a few months afterwards, through Dr. Bea- don’s recommendation, he became the tutor of the Hon. Henry Tufton, with whom he made the tour of Great Britain in the summer of 1791. This was undoubtedly a most important epoch in Mr. Clarke’s life; it was the first opportunity he had of gratifying a passion which was always uppermost in his mind, but which he had hitherto been unable to indulge; and it necessarily threw in his way many opportunities of acquiring ——_ —— 1824.] late Rev. Dr. Clarke. 403 information in those branches of natural history, for which he had early shown a decided taste, and to which he afterwards owed so much of his celebrity. 1t was likewise the cause of his first appearance before the public in the character of an author ; he kept a journal of his tour, and at the request of some of his young friends, upon his return, was induced to publish it. The work is now exceedingly scarce, the greater part of the copies having been destroyed or lost within a short period after its publication. Indeed, Mr. Clarke himself soon learnt to have a lower opinion of its merits than others perhaps, more considerate, would be disposed to entertain, when the age and circumstances of the author are taken into the account. In October, 1791, Mr. Tufton’s brother being about to join Lord Thanet in Paris, Mr. Clarke and his pupil seized the oppor- tunity of passing over with him to Calais, and thus he who after- wards traversed so large a portion of the globe, first set his foot on foreign ground; a circumstance which imparted to his ardent mind the most delightful sensations. In the spring of the year 1792, his engagement with Mr. Tufton terminated ; and Lord Berwick, who had been of the same year with him in College, and was now of age, proposed that Mr. Clarke should accompany him, in the capacity of a friend, to Italy. This proposal was soon agreed to, and about the middle of July, they set out on their intended tour. As it was necessary to avoid the French terri- tory, which was then agitated throughout by the paroxysm of its ferocious revolution, they took the route of the Low Countries to Cologne, and then ascending the Rhine to Schaffhausen, passed from thence through Switzerland, by the way of Lucerne and St. Gothard, to Turin. To a mind like that possessed by the subject of this memoir, panting for foreign climes, and glowing with all the warmth of poetic imagery, it was no small achievement to have thus passed. the barrier of the Alps, and to tread in the paths which had been hallowed in his eyes by the footsteps of Addison and Gray. But this was only a part of his enjoyment while on this tour. The country which he had entered, abounded in scenes and objects calculated, above all others, to awaken every pleasing association connected with his early studies, and io gratify his prevailing taste. The precious remains of antiquity dispersed throughout Italy, the fine specimens of modern art, the living wonders of nature, of which even the descriptions he had read, or the faint resemblances he had seen, had been sutficient to kindle his enthusiasm, were now placed before his eyes, and submitted to his contemplation and inquiry; nor were the springs and resources of his own mind unequal to the excitement which was thus powerfully acting upon them. At no period, even of his subsequent life, does he seem to have exerted himself with more spirit, or with better effect. He made large and valuable addi- , 2D 2 ~ 404 Biographical Sketch of the (Dec. tions to his stock of historical knowledge, both ancient and modern. He applied himself so effectually to the French and Italian languages, as to be able ina short time to converse fluently, and to obtain all the advantages of acquirement and information in both ; and, what was less to be expected, by dint of constant and persevering references to those classical authors, whose writings have contributed, either directly or indirectly, to illustrate the scenery or the antiquities of Italy, he made greater advances in Greek and Latin than he had done before, during the whole period of his education. He studied with great atten- tion the history and progress of the arts, and, more particularly, of the different schools of Painting in Italy; reading carefully the best authors, conversing frequently with the most intelligent natives, and then, with all the advantage of his own good taste and discernment, comparing the results of his inquiries with those of his own actual observation. Nor was his attention less powerfully attracted towards those rich treasures of Natural History, which the peculiar resources of the country, or the industry of collectors daily presented to him. Vesuvius, with all its various phenomena and productions, was his particular study and delight. He was the historian and the guide of the mountain, to every intelligent and distinguished Englishman, who came to Naples during his stay; and connect- ing, as he did, a considerable degree of science and philosophy, with all the accurate local knowledge, and more than the spirit and adroitness of the most experienced of the native guides, his assistance was as eagerly sought after as it was highly appre- ciated by his countrymen. He made a large collection of vases and medals, many of which have since found their way into different cabinets of Europe; and besides numerous valuable additions which he made to his own specimens of minerals, he formed several complete collections of Italian marbles and vol- canic products for his friends. With his own hands he constructed models of the most remarkable temples and other interesting objects of art or nature in Italy ; and one particularly of Vesu- vius, upon a great scale, of the materials of the mountain, with such accuracy of outline and justness of proportion, that Sir William Hamilton pronounced it to be the best ever produced of the kind, either by foreigner or native; it is now at Lord Ber- wick’s seat at Attingham, in Shropshire. These things he did, and much more, within an interrupted space of two years, during which, as it appears from his journal, so many of his ‘hours were placed by his own good nature at the disposal of his countrymen in their literary or philosophical inquiries, so many others were dedicated as a matter of duty to Lord Berwick and his concerns, and so many more were devoted to the pleasures of society, and to those active amusements which our country- men usually assemble round them whenever they take up their 1824.7 tate Rev. Dro-Clarke. ~ 405: abode together, and for which the fine climate of Italy is so well. adapted, that it must be a matter of surprise to learn, that he was able to do so much for himself. Nor will this surprise be lessened, when it is known, that besides his journal, he left behind him a great number of manuscripts connected with this tour, including some maps of his own construction. In the winter of 1793, Lord Berwick having formed a plan of a voyage to Egypt and the Holy Land, and submitted the prepa- rations for it to Mr, Clarke, his whole time and thoughts were, for several weeks, almost exclusively occupied in this project. In the month of November he left Naples for England, on some particular business for his lordship, which he had undertaken to execute, in order to facilitate their journey to the east, and was landed at Dover on the 30th. Having arranged the business in question, he was on the point of setting off on his return, when he received a letter from Lord Berwick, intimating the sudden postponement, or, in other words, the abandonment of the voyage. “ It would require a very intimate knowledge of the sanguine character of Mr. Clarke,” his biographer, Mr. Otter, remarks, ‘and of his passionate desire for seeing Egypt and Greece, to ap- preciate adequately the effect of this communication on his mind; butit may suffice to say, that the disappointment was felt by him more bitterly than any which he had ever before experienced in his life; that for many years it was even breaking out in his letters and conversation, and that it could never be said to be entirely overcome till under other auspices, and at a maturer age, he had been permitted to drink freely of that cup which was at this time unexpectedly dashed from his lips.” Mr. C, set off on his return for the Continent on the 20th of January, 1794, and arrived at Naples early in March. His residence there with Lord Berwick, however, continued only for three weeks more ; and travelling by Rome, Aosta, and St. Remy, through Switzerland to Manheim, and thence by Mayence to Cologne and the Low Countries, they landed at Harwich on the 8th of June. In the autumn of the year 1794, at the recommendation of the Bishop of St. Asaph, Dr. Bagot, Mr. Clarke was requested to undertake the care of Mr. Mostyn (now Sir Thomas Mostyn), at that time a youth of about seventeen years of age. He accord- ingly went to reside with Sir Roger Mostyn’s family, at Mostyn, in Wales, but, for some unexplained reason, the connexion ended in little more than a year. In the course of the general election of 1796, he was one of a large party assembled at Lord Berwick’s seat in Shropshire, at that time a scene of prodigious interest and agitation, in consequence of the contest for the borough of Shrewsbury, between the Hills of Attingham, and the distinguished family of the same name, and of a kindred race, 406 Biographical Sketch of the [Dec. at Hawkstone. This contest was the means of exhibiting Mr. Clarke’s talents in controversy,—a field in which they had never been exercised before, and in which, happily for himself, they scarcely ever appeared afterwards. The occasion of it was this : a long and laboured pamphlet, called “ Hard Measure,” had just issued from the opposite party, written as was supposed by Sir Richard Hill himself, and containing many sharp and cutting reflections upon the Attingham family and cause, with some strong documents in support of them. To this it was necessary to reply without delay; and for the sake of greater dispatch, several literary friends of Lord Berwick, who were in the house, undertook to divide the task amongst them, each taking the part which he thought himself most competent to answer; but as it was afterwards evident that this scattered fire would be much more effectual, if skilfully brought together, and directed by a single hand, Mr. Clarke was fixed upon for this purpose, and to him was confided the delicate and difficult operation of select- ing, shaping, and combining, from the materials so prepared ; with permission, of course, of which he availed himself largely, to add whatever arguments of his own he might think likely to increase the general effect. Accordingly, he set himself to work with his usual spirit, and having scarcely slept while it was in hand, he produced, in a very short time, matter enough for a quarto pamphlet, of a hundred closely printed pages, which, having been carefully revised by the lawyers, was rapidly hur- ried through the press, and immediately published, under the happy title of “ Measure for Measure.” This work answered completely the object it had in view: it produced a great sen- sation at the time, was a source of no inconsiderable triumph to the party whose cause it advocated, and, as it is believed, received no reply. Mr. Clarke accompanied Lord Berwick to Brighton, in the autumn of the same year, and there commenced a periodical work, entitled, ‘‘ Le Bivenr, or the Waking Visions of an Absent Man.” It proceeded no further than the twenty-ninth number, the first of which was dated Brighton, Sept. 6, 1796, and the last, London, March 6, 1797. With the exception of a single number, or at most two numbers, furnished by his valued friend the Rev. George Stracey, and two short poems, one by Miss Seward, the other by Dr. Busby, afterwards Dean of Rochester, it was entirely the production of his own pen. The principal materials upon which he depended, were the substance of the information he had gathered, and of the observations he had made in the different situations in which he had lived, whether at home or abroad, since the publication of his tour; but as these were of a nature soon to be exhausted, and as the contri- butions of his friends came in but slowly, we cannot wonder that it was brought to a conclusion within the compass of a few 1824.] late Rev. Dr. Clarke. 407 months. Before it had extended so far, also, the author was engaged in an occupation which required the greatest part of his time, and all the attention he couldcommand. The work is now no longer to be found: the separate numbers, which obtained no great circulation, have, it is thought, perished long ago, with few if any exceptions: and the volume in which they were afterwards reprinted collectively, was stifled by an aceident in its birth ;—some cause of delay had intervened to prevent its publication, and the whole impression was found in the book- seller’s warehouse, so injured by the damp that nota single copy could be made up for sale. By this time, however, Mr. C.’s fears respecting the success of his work had begun to predomi- nate over his hopes ; and he afterwards confessed to a friend, that he was never more delighted in his life, than when this accident so completely put an end to both. The next occurrence to which the history of Mr. Clarke’s life conducts us, is his connexion with the family of the late Lord Uxbridge; a connexion formed, it is uncertain under what auspices, or upon what terms, but eventually not less honourable to Mr. Clarke, than satisfactory to many members of that family, to whom, in the course of his engagement, he became intimately known. The first object of his care was the youngest son of the family, the Honourable Brownlow Paget; a boy of tender age, and of a constitution so very delicate, as to render it advisable that his education should be commenced as well as continued at home. In this view an engagement of some standing with Mr. C. was contemplated by the family ; and rooms having been expressly prepared for their permanent residence together, at Beau-Desert, the seat of Lord Uxbridge, in Staffordshire ; he joined his pupil at that place, in the autumn of 1796. In the following spring, however, Mr. Paget’s health, which had hitherto been considered as only delicate, began visibly to decline, and before that season was far advanced, his disorder arrived at a fatal termination, Mr. Clarke’s connexion with Lord Uxbridge, though interrupted, was not broken, by this unhappy blow. The family had too much regard for his past services, and were too sensible of his many excellent qualities and talents,—which had been displayed in a manner endearing to them when his services as a tutor had ceased to be of any use to his pypil,—when the exercise of his kindness as a friend was alone available, —not to desire to profit by them, so long as any occasion should remain; and, on the other hand, Mr. Clarke was too deeply impressed with the value of their friendship, not to acquiesce readily in any similar arrangement which could be proposed. Happily, ina few weeks, an opportunity offered itself for gratifying the wishes of both. The next youngest son of the family, the Honourable Berkeley Paget (now one of the Lords of the Treasury), had finished his education at school, and had 408 Biographical Sketch vf the [Dec.. been admitted at Oxford: and, it having been thought advisable that the summer before his residence in College should be spent in travel, Mr. Clarke was desired to undertake the tour of Scot- land with him, and the plan was carried into execution without delay. This journey, which was begun in the summer, and concluded in the autumn of 1797, furnishes considerable extracts for Mr. Otter’s work. ‘“ Mr. Clarke’s journal,” he observes, “is very full and particular, and evidently drawn up with a view to the publication of it by himself. At several subsequent periods of his life, preparations were made by him for this purpose ; and so late as the year 1820, an advertisement was drawn up, announc- ing it to the public, and a part of the manuscript was actually transcribed for the press. Beyond this, however, no farther step was ever taken towards the completion of the work, and in the pressure of other Jabours, which occupied him to the last moment of his life, abundant reason might be found for the delay ; but in truth, there was another obstacle, which requires some explanation, because, whatever share it may have had either in delaying or preventing the publication of the journal by himself, it certainly led to a restriction, which must diminish the interest of the extracts, when selected by another. ‘This obstacle was the unsettled nature of his opinions respecting certain facts, connected with geology, accidentally a preminent feature in the tour. In the course of his Italian travels, his attention was frequently and specially directed to the two great theories, which at that time divided, and have since continued to divide, the judgment of philosophers, in every part of Europe. To this subject allusions are often made in his Italian journal, as well as in his letters after his return ; and the interest thus excited in his mind, although afterward apparently suspended, was revived with much greater force, when the journey to Scot- land was proposed to him. It was not that he attached an undue importance to any opinions he might form in that early stage of his knowledge; but he was eager to engage in the inquiries to which the controversy had given rise; and having had frequent occasion during his residence in Naples, to notice the observations of Scotch gentlemen, relative to the resem- blance which they affirmed to exist between the minerals of the Western Islands and the productions of Vesuvius, he was willing to believe, that by a stricter scrutiny of this tract than it had hitherto received, he might be able to ascertain more cor- rectly the nature and extent of this resemblance, with its proper bearing upon the controversy ; and he was the more sanguine in this hope, because after the particular attention which he had paid for nearly two years, to the operations of subterraneous fire, both in a state of activity in Vesuvius, and in the traces of its influence among scenes no longer subject to its immediate. 1824.] late Rev. Dr. Clarke. 409: agency, he thought himself so far competent to recognize them in any other country, if they were to be found. This is the substance of his own acount, and one natural consequence of his pre-occupation was, that his attention was more alive upon the journey to geological facts, than to any other; and that a larger portion of his time and labour was hestowed upon this question, than it would naturaily have claimed, in a tour not undertaken expressly with a view ‘to it. Had this, however, been the only objection, the reader might not have lost much ; for whatever value might be attached to his inferences at that time, his researches are often curious and minute, and his reasoning always ingenious and amusing; but it unfortunately happened, that the leaning of his judgment in the course of his tour, seems to have been in a different direction from that which it afterwards took, when, in a maturer state of his own know- ledge, the learned and accurate labours of Dr. Maculloch had been submitted to him. Hence the difficulty, which applied to himself, and hence the restriction enjoined upon his friends ; in conformity to which they feel themselves compelled to withhold, not only those parts of his journal in which his arguments are directly stated, but even ull the more general remarks from which his mode of reasoning might be inferred.” The limits to which we are necessarily confined preclude us from enlarging on this northern tour, which occupied Mr. Clarke and his companion three months, from June 22 to Sept. 26, 1797. The narrative of it in the work is carried on from the isle of Ailsa to the conclusion of the journey, from Mr. C.’s journal; written in an extremely animated and pleasing style, and describing the scenery of the Western Islands and of the country through which they passed, in an interesting and vivid manner. At Easter, 1798, having been elected a Fellow of Jesus College before his departure for Scotland, Mr. Clarke prepared to take up his residence there. Inthe mean time a new engage- ment was proposed to him, which led eventually to important consequences; being the cause of his undertaking, and the means of his completing the extended tour in Europe, Asia, and Africa, from which the fame he subsequently acquired was principally derived. ‘The object of the proposal was a young man of his own neighbourhood, in Sussex, Mr. Cripps; who having lately succeeded to a considerable estate in that county, was desirous of placing himself under the guidance and instruc- tion of Mr. Clarke for three years, in the meritorious hope of supplying the defects of an indifferent education, by those means, which though late were still within his power. In the pursuit of this advantage, the place was of secondary import- ance to him, and he was easily induced, at Mr. Clarke’s recom- 410 Biographical Sketch of the [Dec. mendation, to admit himself a Fellow-commoner of Jesus College, and to accompany his tutor to Cambridge; with an understanding, which was equally agreeable to both, that after a certain time spent in preparatory study, they should undertake some journey to the Continent together. The pecuniary part of the proposal was very liberal; the plan was entered upon without delay; and during the next twelvemonth, Mr, Clarke resided constantly with his pupil at Jesus College. Mr. Clarke and the early and intimate friend who has become his biographer, the Rev. W. Otter, had long entertained a scheme of going abroad together, and during this year of his residence in Cambridge, he often urged upon Mr. O. the imme- diate execution of this plan. As no part of the Continent was then open to English travellers, but the north of Europe, it was at length determined, after various plans had been proposed and rejected, that they should visit Norway and Sweden, with as much of Russia besides, as could be comprehended within the extended limits of a long summer vacation. Mr. Cripps was of course of this party from the beginning, and with it was after- wards associated a gentleman since highly distinguished in the literary world, Professor Malthus. The party set out from Cambridge on the 20th of May, 1799, and the journey which was at first intended to occupy only SIX or seven months, was continued by Mr. Clarke and his pupil for more than three years and a half, having been concluded in the latter end of November, 1802. Their companions, adhering to the original arrangement, left them near Lake Wener, inSweden, and thence proceeded to the south of Norway. Dr. Clarke’s “ Travels” having been so extensively perused, and the general course of the tour being in consequence so well known, we shall dismiss the subject with the following brief state- ment of its extent, extracted from a letter to Mr. Otter, dated Con- stantinople, Feb. 15, 1862 :—‘ Inexamining the extent of our tra- vels by Mercator’s chart, I found they comprehend _ no less than 45 degrees of east longitude, from the meridian of Greenwich to that of Cape St. Mary, in the isle of Madagascar ; and 38° 30/30” of North latitude. We have visited three of the four quarters ; Europe, Asia, and Africa; and certainly in Asia, the tract we passed over comprehends no small field of inquiry. The globe offers very little variety of climate, to which we have not been exposed, and in the examination of its productions, we have the satisfaction to hope, that you will neither reproach us with idle- ness nor neglect.” The travellers left Constantinople in the suite of the Ottoman Ambassador to France, and passing through Bulgaria, Wallachia, Transylvania, and Hungary, arrived at Vienna in May, whence they set out for Paris in the beginning ef. July, and returned to England in October, 1802; Mr. C. 1824.] ' late Rev. Dr. Clarke. 411 commencing his permanent residence at the University towards the end of the following month. For some time Mr. Clarke took no College office, nor was such an employment essential to, or even compatible with his views, for Mr. Cripps still continued with him as his pupil, and the engagements arising out of his travels were quite sufficient to oc- cupy all the time he had to spare: amengst these his first care was to collect and examine the cases and packages, containing their acquisitions in the various departments of antiquity, art, and science, which had been awaiting their arrival at the different; eus- tom-housesof the country. Mr.C. had sent to England more than seventy cases of his own before he left Constantinople, whilst his companion had upwards of eighty, obtained under his advice and influence ; and considering the’ remoteness of the places from which they had most of them been dispatched, and the variety of conveyances to which they had been entrusted, so little had been sustained by them, either of loss or of injury, as to be matter of just congratulation to the collectors. Ofall these treasures, the first place in Mr. Clarke’s mind was given to the Eleusinian statue of Ceres; and this, not only on account of the high distinction to which the statue was destined in the University, but for the rank he assigned to it, amongst the monuments of the purest age of Grecian sculpture, and the many classical associations connected with its history. By the liberality of Government, it was allowed to be taken out of the custom-house duty free; and when at last a place had been assigned to it by the University authorities in conjunction with the donors, and the proper preparations had been made for its reception, it was securely placed upon its pedestal, with all due form and honours, in the most conspicuous part of the vestibule of the Public Library, on the Ist of July, 1803 ; and the names of Dr. Clarke and Mr. Cripps were, by the desire of the Univers sity, inscribed upon the base. The public appearance of the statue was quickly followed by a tract from Mr. Clarke’s pen, which naturally grew out of the transaction, and was indeed important to the illustration of it. In this work, which is enti- tled “Testimonies of different Authors, respecting the Colossal Statue of Ceres,” the monument in question is clearly proved to be the very individual bust, described as lying at Eleusis, by Wheler and Spon, Pococke, Chandler, and others, and consi- dered generally as the representation of the Goddess. In the winter of this year a grace was passed unanimously in the senate of the University, for conferring the degree of LL.D. upon Mr. Clarke, and that of MA. upon Mr. Cripps; and to mark with more distinction the sense of the University, in conferring these honours, a third grace was subsequently carried, to defray the whole expense of Dr. Clarke’s degree from the University chest. 412 Biographical Sketch of the [Dec. * The next object connected with his travels to which he directed the public attention, was the celebrated Sarcophagus, now in the British Museum, captured from the French at Alex- andria. It is well known how instrumental Dr. Clarke had been in discovering this noble monument of Egyptian art, when it bad been clandestinely embarked for France, on beard a hospital ship, in the port of Alexandria, and in rescuing it from the hands of General Menou, and the French Institute, who clung to it with a degree of obstinacy almost incredible: and it was very natural that the interest he had taken in it in Egypt, should revive with its arrival in England; especially as the origin of the monument soon became the subject of much spe- culation and perplexity amongst the learned, and Dr. Clarke conceived himself to be possessed of evidence calculated to throw light upon it. Under this impression he drew up, in 1805, a Dissertation on the Sarcophagus in the British Museum, brought from Alexandria. It was inscribed to Lord Hutchinson, under whose authority he had acted in Alexandria, aud the main object of it was to vindicate the pretensions of the monument to the title of the tomb of Alexander. To this hypothesis he had beea first Jed by the name it bore (the tomb of Iscander), amongst the most ancient race of the neighbouring inhabitants, coupled with the extreme veneration felt for it as such by the Turks and other persons of every description in the city of which. this hero was the founder; and having been afterward partially confirmed in his opinion by the reports he found in the works of early travellers, as well as by the conversation of learned men on the continent, and at last more decidedly by an accurate examination of such classical authors, as had treated of the subject of Alexander’s death and burial, he collected his proofs and arguments in a manuscript, which, after being handed about among his friends, in 1804, was by their advice published in the following year, under the title already mentioned. The work had been placed in the hands of Lord Hutchinson, with a view to its being printed by the Antiquarian Society, but was afterward withdrawn at the suggestion of his friends, who thought it would appear more expeditiously, as well as advanta- geously, from the University press, the managers of which undertook to print it. “Tt was ornamented with an accurate coloured engraving of the tomb, from a drawing by Alexander, and accompanied with several appendices, in one of which was inserted a learned and ingenious illustration by Dr. Parr, of a Greek inscription found among the ruins of Tithorea by the author; and being the first book m which the name of Edward Clarke had appeared in the title page (all his former publications having been anonymous), it was. otherwise got up with great care, and at no inconsiderable cost. But this over-nursing was in one respect injurious to it. 1824.] late Rev. Dr. Clarke. 413 The subject, though excellent for a pamphlet, was neither popu- lar nor comprehensive enough for the expensive form in which it was thus obliged to appear (the price was 1|$s.), and the intro- duction of such topics as the ruins of Sais and Tithorea, how- ever interesting in themselves, was so far injudicious, that it injured the unity of the piece, and added to the expense without furnishing any ground for the argument: thus, notwithstanding the advantages under which it came out, the work was by no means lucrative, either to himself or his publisher, Mr. Mawman, in whose hands a large number of copies remained for many years. To the author, however, it was productive of essential advantage in many ways. By the few who read it, it was, for the most part, well received and highly estimated: amongst whom are mentioned by himself, Porson, Parr, Dr. Zouch, Lord Aberdeen, Dr. Henley (Principal of Hertford College), Dr. Knox (his early tutor), Mr. Tyrwhit, Mr. Matthias, &c.; all of whom eave their countenance and approbation, and some their assist- ance or advice in the work. It was the means, also, of making him more favotrably and more intimately known to other men of learning and genius, whose friendship he never lost. . Above all, it gave him confidence in his own powers, and enabled him’ to stand upon much higher ground, when soon afterwards he had to treat with the booksellers for his travels. Nor can it be denied, that his position was maintained with great ingenuity : by many learned persons, the proofs were considered conclu- sive, as their letters show; others, more reserved, readily expressed their surprise that such a mass of evidence existed ; and all were disposed to allow, that a vague and obscure tradi- tion had been elevated in his hands to the rank of alearned and probable conjecture. The extraordinary activity of Dr. Clarke’s mind enabled him, in the very midst of a controversy to which this publication gave rise (Easter, 1805), to compose and send to press “a treatise on Mineralogy, principally intended for students, of which the following notice is given in a letter to Dr. Henley :— ‘T have already sent another work to the press, very different in its nature, which will be mere play to me this Easter vacation. It is “an easy and simple method of arranging the substances: of the mineral kingdom,” by which | hope to make mineralo- gists, as fast as Bolton makes buttons. ‘The introduction only 1s addressed to persons rather above the class of students, and is intended to develope the theory of elementary principles, the cause and origin of the fluid matter of heat, the formation of atmosphere, &c. &c. [It is a portable volume, small and plea- sant for travellers.’ The work was never published, and its existence is scarcely known to any of his friends, but one or two copies were found amongst his papers, and a slight view of it is sufficient to show that it must have cost him considerable time 414 Biographical Sketch of the [Dec, and labour, at the moment his hands appeared to be full of other things.” Dranaiatenenig’ conaexion which Dr. Clarke had now for some time contemplated, rendering it necessary for him to enter into professional life, he determined to take holy orders, and was or- dained by his old friend, the Biskop of Bath and Wells, in Dec. 1805, and immediately instituted to the vicarage of Harlton, belonging to Jesus College. On the 25th of March, 1806, he was married to the lady of his choice, Miss Angelica Rush, the fifth daughter of Sir Willian Rush, of Wimbledon; and to this union, from which, and for reasons apparently cogent, unhappy consequences had been anticipated by his friends, his future life was indebted for its greatest happiness, and even its prosperity. The course of Dr. Clarke’s life now turns from this happy union to a department of his labours, which had long been upper- most in his own thoughts, and next to his ‘ Travels,’ obtained for him his highest distinctions, as a literary man :—viz. his Lec- tures on Mineralogy. During the whole course of his travels, that science, and the objects connected with it, obtained everywhere the greatest share of his attention, and had been cultivated by him with the greatest success ; to which several circumstances had contributed. Low at that time as was this branch of natural history in our Universities, it had risen under a variety of encouragement and patronage—the result of policy as well as of taste—to a high degree of importance in every pub- lic establishment for education on the Continent; and, as Mr. Clarke brought letters of recommendation to the most eminent professors wherever-he went (an advantage which his own spirit always contributed to improve), he was in all places cheerfully admitted to a participation ofall the local discoveries or improve- ments, and supplied with specimens of all such minerals as they respectively produced. But this was not all; the course of his travels often led him to remote districts, particularly in the eastern and southern parts of Russia, not accessible to the ordi- nary mineralogist; and as he spared neither pains nor money in his researches, besides a very ample store of minerals more or less known, he brought to England several rare and valuable specimens, which were for some time almost peculiar to his collection : and it may be affirmed generally, that of all the fruits of his travels, his acquisitions in this department were infinitely the most precious in his eyes. To bring forward, therefore, this collection before the public eye, and with more advantage than his own limited apartments would permit,—to communicate to, others the lights which he himself had obtained, and to dissemi- nate throughout the University a portion of that flame which burned within himself, were, from the first, subjects infinitely more pressing in his mind, than the hope of reputation or advantage from any other quarter; and as the only obvious means of 1824.] late Rev. Dr. Clarke. 415. embracing at once these objects was the delivery of lectures under the patronage of the University, it was to the attainment of this, that his best efforts, from a very early period after his return, were uniformly directed. But the task was not an easy one. The subject was little known and less studied, and. by no means popular in the University ; nor was there any room suited to the purpose, but what was either pre-occupied or ‘appropriated ; and besides, there was an apprehension of the. Lectures interfering with the Woodwardian Professorship, at that time occupied by a gentleman for whom Dr. Clarke had justly a very great respect. By degrees, however, all these: difficulties gave way. Every facility was afforded by the Uni- versity to the plan ; Dr. Martin, the Botanical Professor, gave up his room in the Botanic Garden, which his age and infirmi- ties prevented him from using himself; and the Woodwardian Professor, whose proper department was Geology, so far from considering these Lectures as an interference with himself, kindly concurred in every measure which was required for their establishment. In short, as soon as he could enter upon it, Dr. Clarke had the happiness to find, that the field was open to him without either opposition or ill-will, and the fiat of the Vice- Chancellor followed almost as a matter of course. Having, therefore, finished his preparations, which were both expensive and laborious ; and having published a new synopsis of the mineral kingdom, and an extensive syllabus, he at last announced a day for the opening of his Lectures, the 17th of March, 1807. They were crowned with complete success; and in the course of the following year, his reputation as a Mineral- ogist, in the University, was so far established, as to encou- rage his friends in the hope of obtaining for him the establish- ment of a new Professorship in his name. This measure met at first with some opposition, and having been prema- turely pressed, had in the first instance failed; but in the latter end of 1808, the second year of his Lectures, the sense of the University having been previously tried, a grace to that effect was brought up to the senate by the Proctor, the Rev. G. D’Oyly (now Dr. D’Oyly, Rector of Lambeth, &c.) and carried almost unanimously. Thus were his most sanguine wishes crowned with success, and thus were his spirit and perseverance rewarded with one of the rarest and the highest honours which the University could bestow. Not long afterwards the rectory of Yeldham, in Essex, was presented to him by Sir W. Rush. The next important concern in which he engaged was the disposal of the manuscripts he had collected im his travels. These, after having been examined by Prof. Porson, and other eminent scholars, were purchased in 1809 by the Curators of the Bodleian Library, at Oxford, for 1000/. His Greek coins, the 416 Biographical Sket ch of the (Dec. fruits of the same travels, he disposed of to the late Mr. Payne Knight, in the course of the next year, 1810. On both these occasions Dr. Clarke displayed great liberality during the nego- ciation, with much anxiety for the ulterior use and destination of the collections. Early in the year last mentionéd, the first volume of his ‘Travels’ appeared, the second in 1812, the third in 1814, the fourth in 1816, the fifth in 1819: of the sixth only twelve chapters were finished at his death; the rest were added by his friend the Rev. Robert Walpole, to whom the pub- lic are indebted for many interesting and valuable notes in the former volnmes. The year 1817 opened with a most flattering testimony of the esteem in which he was held in the University, by his election to the office of Sub-Librarian, vacant by the death of Mr. Davies, and the promotion of Mr. Kerrich to that of Principal Librarian. His attention during this year was principally occu- ied by his experiments with the ‘ Gas Blowpipe,’ most of which he described in the Annals.* In the same year he con- tributed two papers to the Society of Antiquaries, and one to the Geological Society; all which have been noticed in the Annals: (vol. ix. p. 395, and N.S. vol. vii. p. 73). In 1819 he collected his experiments with the ‘ Gas Blowpipe’ into a small octavo volume, which was published under that title, with engravings of the instrument, the safety apparatus, &c. This year also produced his Dissertation on the Lituus, read before the Antiquarian Society in 1820, and published in the Archeologia for i821. _ Dr. C. was one of the most zealous founders of the Philo- sophical Society of Cambridge, and drew up, for the first meet- ing, an address explanatory of the design and objects of the Institution. This address is given in the Annals for March, 1821. He afterwards communicated three papers to the Society, which were printed in the first volume of its Transactions. The history now advances towards the close of a life which had been long struggling with labours disproportioned to his strength, and was at last seen to sink under the workings ofa mind too powerful and too active for the mortal part with which it was united. The progress of his disorder was slow, but the steps of it were strongly marked. At no time since his return from his last journey, could his health be considered as well established ; and besides many other occasional derangements of his system, there was scarcely a single year in which the exertions and confinement attending his Lectures did not bring on some serious illness, frequently accompanying, but generally following them ; and when these were over, instead of relaxation * See vol. viii. p. 313, 357; vol. ix. p. 89, 162, 194, 326; vol. x. p. 373. Both series of the Annals contain papers on various other subjects by Dr. C.; and the last he ¢ver wrote will be found in the number for March, 1822 ; N.S, vol. ili, p. 195. 1824] late Rev. Dr. Clarke. 417 and repose, he often found such long arrears of composition, or correction for his Travels as required the strongest application to recover. It was not so much the number and variety of his employments that broke down his health, as the extreme and intense anxiety with which some of them, particularly the philo- sophical, were pursued by him; an anxiety which intruded upon his hours of rest, and rendered him insensible to those corporeal warnings, which usually guard other men against too continued or too intense an employment of their faculties. In the autumn of 1821, his wife, far advanced in pregnancy, and three of his younger children, sickened one by one with a typhus fever; and in a few days were all reduced by the violence of the disorder to a state of the most imminent danger. All happily recovered ; but the fatigue and anxiety which Dr, Clarke underwent, aggra- vated the symptoms of his disorder, on its return in the winter of this year. This was succeeded by a sort of crisis, during which he was more thoroughly sensible of the perilous state of his health, than at any other period either before or after. “ A short and deceitful interval of ease followed, in which the intermitting of the disorder gave him reason to hope that he was slowly recovering ; under which impression he entered once more, in the middle of the month, upon a course of chemical experiments, preparatory to his Lectures, which were to begin im March; and from the moment he had stepped within the circle of these fascinating operations, there was no longer either thought or power of retreating ; for the usual excitement attend- ing this preparation co-operating with the effects of the disorder, which ultimately terminated in an affection of the brain, brought on a course of unnatural efforts, infinitely exceeding all his former imprudencies, and partaking strongly of the delirium which quickly followed. ‘1 have left him in an evening,’ says a friend, ‘ about this time, with a promise that he would go to bed, and on the following morning have found that he had been up a considerable part of the mght, engaged in a series of unwholesome operations with sulphuretted hydrogen.’ In this melancholy state of self-abandonment, deaf to the remonstrances of his friends, insensible of his own danger, almost incapable of self-control, and intent only upon the due performance of his approaching duties, he supported _an ineffectual struggle with his disorder till the middle of February, when his strength entirely failing him, and being no longer able to stand up, he sunk reluctantly into his bed, and from thence dictated to his servant the course of operations he wished to pursue, and there received from him the results. Up to this time, however, the arrangements of his mind seem to have been vivid and distinct as far as philosophy was concerned, and its energies unabated. His last paper, in the Annals of Philosophy (N.S. vol. iii. p. 194), is dated the 6th of February, and contains a clear statement of New Series, vou. viii. 25 418 Biographical Sketch of the late Rev. Dr. Clarke. [Dxc. a complicated operation in chemistry, for obtaining cadmium from sheet zinc. On Tuesday the 12th, he wrote from his bed upon the same subject to the Rev. Mr. Lunn (who had frequently assisted him in his operations); and on Thursday the 20th, another letter to Dr. Wollaston, reporting his last operation. On Friday the 21st, Mr. Lunn saw him, when he was quite rational upon this subject, as far as he was permitted to speak, though sick and in bed. On Saturday he was carried to town for advice, by Sir William and Lady Rush, where he was at- tended by Sir Astley Cooper, Dr. Bailey, and Dr. Scudamore. But their efforts to save him were in vain; the rest of his life, about a fortnight, over which a veil will soon be drawn, was like a feverish dream after a day of strong excitement, when the same ideas chase each other through the mind in a perpetual round, and baflle every attempt to banish them. Nothing seemed to occupy his attention, but the syllabus of his Lectures, and the details of the operations, which he had just finished : nor could there exist to his friends a stronger proof that all control over his mind was gone, than the ascendancy of such thoughts, at a season when the devotion so natural to him, and of late so strikingly exhibited under circumstances far less trying, would, in a sounder state, have been the prime, if not the only mover of his soul. One lucid interval there was, in which, to judge from the subject and manner of his conversation, he had the command of his thoughts as well as a sense of his danger ; for in the presence of Lieut. Chappel and Mr. Cripps, he pro- nounced a very pathetic eulogium upon Mrs. Clarke, and recommended her earnestly to the care of those about him; but when the current of his thoughts seemed running fast towards those pious contemplations in which they would naturally have rested, his mind suddenly relapsed into the power of its former occupants, from which it never more was free. At times indeed gleams of his former kindness and intelligence would mingle with the wildness of his delirium in a manner the most striking and affecting ; and then even his incoherences, to use his own thought respecting another person, who had finished his race shortly before him, were as the wreck of some beautiful decayed structure, when all its goodly ornaments and stately pillars fall in promiscuous ruin. He died on Saturday, the 9th of March, and was buried in Jesus College Chapel, on the 18th of the same month. “< He left seven children ; five sons and two daughters; the eldest not fifteen years ofage at the time of his death. “Few persons have left the world more honoured or more regretted. The tears of genius have been shed around his tomb, and every mark with which respect or kindness can honour departed merit is preparing to grace his memory. ** Amonument, erected in Jesus College Chapel, near his grave, 1824.] Col. Beaufoy’s Astronomical Observations. 419 at the expense of the Master and Fellows, will serve to stimu- late the youth of that Society in the paths of enterprise and science : a bust, executed by Chantrey, at the cost of his literary friends, principally members of the Philosophical Society, at Cambridge, will perpetuate the honour of one of its most distin- guished ornaments and founders: while his collection of mine- rals, fixed by the liberal suffrages of the University within its precincts, will remain an appropriate memorial of the respect paid by that body to their first mineralogical professor. But the best proof of the many excellent qualities of his heart, is the sincere and ready kindness shown towards his family since his death—kindness not less honourable to human nature, than to the individual for whose sake it has been exerted—derived not from the wealthy or the great, by whom it would be lightly felt, but from persons of his own rank and means, and involving sacrifices which nothing but friendship and affection could warrant. : A memoir, originally intended for publication in the Annals, having been the foundation of Mr. Otter’s “ Life and Remains of Edward Daniel Clarke, LL.D.” the foregoing imperfect sketch of Dr. Clarke’s life and labours has been selected from that work, almost entirely in the words of his biographer. A consi- derable proportion of the volume is occupied by Dr. Clarke’s journal of his residence at Naples, and of his tour in Scotland; and by his Jetters to his friends while on his grand journey. These are extremely interesting ; and Mr. Otter’s narrative is perspicuous and well written ; the arrangement of the work is altogether excellent : and we recommend it to the possessors of Dr. Clarke’s ‘ Travels,’ as an indispensable companion to those volumes. E.W. B. ARTICLE II. Astronomical Observations, 1824. By Col. Beaufoy, FRS, Bushey Heath, near Stanmore. Latitude 519 37’ 44°3” North. Longitude West in time 1’ 20-93”, Oct. 17. Immersion of Jupiter’s third oni 59’ 23” Mean Time at Bushey, SHLEIMLE Ps ss cadet a's ake eee f 17 OO 44 Mean Time at Greenwich. Oct. 29. Immersion of Jupiter’s first §15 16 04 Mean Time at Bushey. BALCUILC) Daishs 5 hers inte dintsipaass j 15 17 25 Mean Time at Greenwich. Noy. 2. Immersion of Jupiter’s second $13 26 35 Mean Time at Bushey. Batelite: Seg attos Nine coset ¢13 27 56 Mean Time at Greenwich. Noy. 5. Immersion of Jupiter’s first §17 09 25 Mean Time at Bushey. RALCRLIEE oats Srnisit-< mare iaiey gita 17. 10 46 Mean Time at Greenwich Noy. 14. Immersion of Jupiter’s first ¢13 30 48 Mean Time at Bushey. ts MAelitGs). te citintels s o.ceceieine 5 18 32 09 Mean Time at Greenwich. Occultations by the Moon, Nov. 2. Emersion of 19 Pisces,........ 2h 10’ 13°8” Siderial Time. 420 Mr. Herapath on the Solution of Vx = 2 ([Dxc. Artic.e III. On the Solutionof Y" x = x. By John Herapath, Esq. (Concluded from p. 329.) § 4. Ifin our primitive equation }" x = x we assume & = 4, and J’ x2 = u.,,, g being any quantity, and w a function to be determined, there results “la Prarie a, and by integration wu. = 1" x A, A being the arbitrary constant. But because A is any quantity, and 1" is a well known function of sin 2*** and cos ~4~* it is 3 Qkaz also a function of sin or cos ; and therefore ahi x A 2p Je) aig gy eae n where f is an arbitrary function, and consequently g. Again since . B@Bkazw - 2ZkKAG+v x= u, = 9 sin——, and yr = u,,, = 9 sin — we have n . 2+ v= —— até or Tt chaps G B+ 2Qkva and yx = @sin } Sone Ale Oe tah wees es (25) a solution, with the advantage of being direct, and considerably more simple, is equally as general as either of the former. For instance, in the case of m = 2, if v = 1 and & any odd number, ate Marcin gh ra, Hae where it depends on the form of ¢ to have almost any algebraic form we please for }. Thus if we assume a+be ats ov ? ao ae See OT, our form of y will come out the same as (23), excluding the arbitrary function. And if we consider that : sin (a + 6) =sina.cosb + sind.cosa and cossin~' y= / 1 — 7%, we have 2kva 2Zkva + O~' £&. COS 2 (26) which, from the facility of giving finite and often rational values to the transcendental parts, by choosing proper values for f/, is po=e {Vv 1—¢-* 2°. sin . 1824.) Mr. Herapath on the Solution of Wx = x. 421 frequently preferable to either of the preceding formule in developing algebraic values of ” x. These very simple expressions at once give several of the properties of the functional root. Thus from the manner in which kis introduced, it may be any integral number 0, 1, 2, 3, to infinity ; and therefore, generally, | x will have k functional roots, k being the least integer that will make = an integer. If, therefore, n be an integer, the number of roots will be n; if a fraction, they will be equal to the numerator of the fraction ; and if an irrational number they will be infinite. And since k may be = 9, it follows that whatever be the values of n and v, one value of ¥’ xis x. It should however, in the solution of problems, be carefully considered, whether the conditions of the problem will admit the property ~’x = x when Wao=a. A very skilful mathematician in this branch of analysis, has fallen into error in the solution of one of his problems from not attend- ing to this. Again, because either expression (25) or (26) is symmetrical with respect to v and 4, if k remain constant, and 0, 1,2, .... be substituted for v, the results will be the same as if v remained constant, and 0,1, 2,3, .... be substituted for k. Consequently whatever be the value ofx, the several values of Wz will be equal to f° a,Pa,¥ a, 2, .... This conclusion Mr. FAR ah by 4 arrived at by a very different process in his paper in the Philos. Transac. for 1817, when is an integer; but such a limitation is evidently unnecessary. Let us assume our expression (25) or (26) to be a function of k,v,and x. Then ve=f (=) and }"« = f (=) ; supposing that in the former instance /" x = x; and in the latter v"a =a. If therefore n = pn, RE ai gai fa RRL lak yx =f (=) =f (=) =r and a = v2, Vax = Fu pia — y+ @; ih ens & But if p be an integer, ’ x, W’’ x, .... are, by what we have just shown, functional roots of }" 7 = x. Therefore and because y, 2, 0,° 2, .... are the functional roots of }," © = x, it fol- lows, that if the order of a periodic function be an integral multiple of the order of another periodic, the roots of the latter are roots of the former, whatever be the values of the orders of periodicity. Mr. Babbage has drawn, in the above-mentioned paper, the same inference for integral orders. If in }" x = x we substitute }~" for « we have "v= 4; 422 Mr. Herapath on the Solution of " « = x. [Dec. the }~' x, }~? x, .... values of which are evidently equal to the functional roots of the former. All the preceding properties are analogous to the properties of the roots of unity ; but it would not be correct to conclude from hence that the parallel is strictly true in all cases. For instance, all the roots of unity, except one or two at most, are imaginary. In the case however of a periodic function, every root is real, if the order be real. / It is not one of the least remarkable features of our solutions that every order of the function positive, negative, Xc. is given by the same formula, without the necessity of algebraic resolu- tion ;—a circumstance that has not been accomplished in any other solution with which I am acquainted. Several other con- sequences of high importance also readily flow from our last very simple solution, which I presume it would be in vain to expect from any other. Thus the extraction of any functional root of a periodic function @ x of a given form and order ; and the reso- lution of the equation )" « = 2, so that any order W" x of it may have one given form only, are questions easily resolved from the preceding solution, and obviously much too important in their consequences to need the notice of any particular instances, especially as I have treated on the subject in another place. I shall, therefore, merely indulge myself in the solution of a ver common form, but more general functional equation of the kind than Ihave yet seen solved. Let the equation be DS ae lle Oe ot irene | where a" x = 2, and n, 7, are any numbers. By our (25) we have Qrkia n a’ x = Bsin § + sin? B~" xf vvuees ko0) 6 being the particular form of the arbitrary function which gives the solution in the rth order, the form 2’ x and k' being any one invariable integer. Let usassumexv = u,andax = u.,, Then or = U5) and bac )u, = 9 sin =" iiss Aeamghiteon But the condition «* x = x gives u.,, = u,, and therefore 2hiazan 6 RS ROMEO) n - 2Zhsr as wellas a’ x =u,,, = Bsin———. x=u,= 6 sin is PN hE yt | and 2% A= = sin Arete. Substitute this value for 2 z a in (29), and we have yx = ¢sin { sin" Boat yah mie cae 1824.] Mr. Herapath on the Solution of " x= x. 423, the solution of (27) free from the symmetrical form, and therefore possessing many advantages over it in point of practical conve- nience ; besides being complete for all values of rand n, which no other solutions, hitherto given of (27), are. The solutions analogous to those usually given for a more limited form of (27), are Piri ota Gia Gale Vwi aM TT EEN. vives (92) and ea OL, Ls ay Dew nee OT Eee Saleen sO) . . n : where q is the prime numerator of —, and ¢, x= perfectly arbitrary functions, the latter being limited to symmetrical forms. These solutions are therefore confined to rational values of r and n, or at least of the quotient = and cannot hence be called complete. Their multinomial forms too render them much inferior to (31), especially when they involve a function to be determined. Our (51), it will be seen, demonstrates the practicability of applying Laplace’s method to periodic functions, which has been much questioned. On this method I have some observations to make, which, for the present, brevity obliges me to withhold. §5. From what we have said in deducing (25), it appears 2kraz Zkaraz Os n ? that sin ,and 1", the expressions usually given for the integral of Ciel UN eae (Oe) zpn z are only particular cases of the general integral f (1") or ¢ sin Zkre n Even I ul nl iy, 2 a o ae = pairimact aot ane x S¢ a Tore Tae e3 nm? Ps VEIS IV Vv VI VII 2Zkraz 2k Sz ZkXAz 2krAz aye ——, $, Covers ———,, $, SEC ———, $, Cosec — piss. (85) which is also an integral of (34), and contains eight independent integers k, k', .... and nine arbitrary functions x, ¢, $,, .... is virtually contained in ¢ sin : “- -. For though k, k', .... have no necessary dependence, yet during the time z changes to x + n, which time is simultaneous for each part of (35), they must be relatively constant. Therefore, during this time, cos * Ina letter to Mr. Babbage, dated Feb. 26, 1824, I committed, through haste, an oversight, in stating the last term of this solution, which I here take an opportunity of acknowledging, 424 Mr. Herapath on the Solution of Wx=xr. [Due. Zk Az 2kIAz , tan Qkrart ) +++. are respectively functions of sin 5 and consequently whether we admit ¢, ¢,, .... to be compre- hended in ¢ or not the whole expression (35) sinks to an arbi- Qkrz < And the same coincidence might easily be shown to be true of any other apparently different integral, which from the nature of (34) must contain circular or equivalent periodic functions, so taat (34) has really but one integral, involved, however, in an arbitrary function. This is likewise confirmed by a very simple, direct, and general method that has occurred to me of integrating equa- tions of differences of, I believe, all orders and degrees; and which method is applicable to the direct numerical resolution of algebraic equations of all degrees as well as to other purposes, of which I may say more hereafter. Hence (25) or (26) does not admit of variety from variety of integral, but being obtained directly and without any limiting conditions from the integration, it must possess an equal degree of generality with the integral itself, that is, the integral being of the most general kind, the functional solution must be so too, or in other words complete. A complete solution, therefore, of " x = x has only one arbi- trary function. A direct proof that our (25) is the complete solution may be given thus. Let ¢ a°9~' a denote (25), or any other solution wherein a” is the particular form of }° 2 when¢g a = 2. Sup- pose f” x is also any solution whatever that will fulfil the condi- tionf*2 =a. Putf* « = 6° o-* 2, and changing 2 into 9 2, we have f° ¢ x = ¢ a’ a, in which ¢ is the function to be deter- mined. Now because / and @ are periodics of the same order, this equation is always possible, whatever be the forms of f and a3 and indeed I have in another place given general solutions of “this very problem. It is, therefore, evident, that such a form can be given to the arbitrary function in (25), that this solution shall coincide with any other solution whatever. Consequently (25) comprehends every solution, and is, therefore, the complete solution. This I believe is the first direct and legitimate demonstra- tion that has been given of the completeness of a functional solution. Hence it follows, that the arbitrary constants a,, ,, ¢,, in (21) form a part of the arbitrary function in (25). This is further confirmed by the assumption with which we set out at the com- mencement of § 3, which, being arbitrary, of course gives an arbitrary form to the functional root. Arbitrary functions, therefore, of whatever kind or quantity they may be, substituted for these constants, merely clog the solution without at all con- tributing to its generality; since these functions, and the trary function of sin , that is to @ sin ih ee ee oe — a ee 1824.] Mr. Herapath on the Solution of "x = x. 495 consequences that can in any way flow from them, are naturally comprehended in the arbitrary function of the direct solution. I cannot refrain here, while on the subject of periodic fune- tions, from mentioning two curious cases of periodic solutions which are perfectly successful when the operations are merely indicated but not performed, and yet fail when developed; though the developed and undeveloped values are the same. The first I shall mention was noticed in elucidating some diffi- culties in this calculus to my promising friend and pupil Mr. Mervyn, Crawford, and the next occurred while considering the source of what Mr. Babbage denominates “a very difficult subject.” It was mentioned to him ina letter dated March 22, 1824. Let | x be a periodic of the second order whose solution is evidently F (ayab x)= 0; where the form of F is to be determined. Substitute J x for 2, and it becomes Fipa, Yap = Ffpr, xe} =>o= F fx, bat F is, therefore, symmetrical with respect to and x. Conses quently a solution is, ba" + 2” = 0, in which 7 is unlimited, or ee eS i” es By Ab oe dk go oe oe (Gey Now in all cases the first of these values "7 — x" answers the conditions of the question; for}? «7 = ¥—(Vv— avy = */ a" = x. But in the second valuew. */ — 1, we have Par=xr.(— 1", which if n be of the form, 2 p becomes J? a = x. ty — |, an expression that cannot, with any integral value at least to p, be = a. It may be asked, in what this unexpected anomaly con- sists ? The answer, I conceive, is obvious, if we seek it from the nature of the functions in question. Periodic functions are algebraic expressions whose property of periodicity depends not on the value but the form of the expression. If, therefore, the value be the same but the form be changed, the expression may no longer be periodic. Thus it happens in the above instance, the values of the two expressions are the same, but the forms different—the negative sign in the one case being a mere sign or subtraction, and in the other a factor. This reasoning will appear still clearer in the following case. Suppose we have the equation i oY wee eb iiale d0'(87) ‘ 426 Mr. Herapath on the Solution of V'x =a. [Derc. Ne os Ae eid hae c being a constant. By changing x into -, it appears when n = — 1, that c can only be + 1 or— 1. If, however, Lap- lace’s method of differences be followed, we have for the solution of (37) log? A, — log? x bax = A, C~ Toga IIE) A,, A, being the constants of integration. If now we change x into 23 the solution becomes, putting p for the former exponent, wv e 1 EL —1 a a = A, c? Multiplying this by c, we have che =A, c = 12, which, therefore, satisfies the conditions of equality of the ques- tion without any apparent limitation to c, that is, without the necessary limitation the question requires. A part only, there- fore, of the conditions of the question are satisfied ; and this arises from the periodicity of the exponent being destroyed by the development ofp. if we consider that by changing a into - twice successively, p returns into itself, and suppose p by one such change to become g, we may easily find that Gn e=eCUOL bas 4 And in the same way if x = 1/1, we should have c= V1], provided the value of c be sought by the non-development of the function. These illustrations will, I hope, obviate the difficulty noticed by Mr. Babbage in Phil. Trans. 1817, without having recourse to the ingenious but, I presume, controvertible idea of the func- ‘tion Y x, having simultaneously different values in different parts of the same equation. The same may be said of Mr. Herschel’s views, p. 120, vol. ii. of the Examples. As this is a subject of considerable importance in the theory of functions, [ shall here briefly notice another more general instance of my observation ; namely, that the same expression may be periodic or non-periodic according to its form. In our solution (25), k and 9 are perfectly arbitrary. Take then ® x = sin~' x, and we have Qkva 2k i x = sin—' sin ~*4+0....(39) the former value of which is periodic for every value of 2, pro- vided sin and siz~* act separately and distinctly, but the latter is not. I am aware it will be contended that the arithmetical values of »)° x in (39) when differently developed, are not neces- sarily the same. This may be true in the present case, but it + sin7! sin a} = 1824.] M. Gay-Lussac on Conductors of Lightning. 427 will not hold in (36) or (38), and, therefore, does not militate against the general truth of my position, that the same expres- sion may be periodic or non-periodic according to the form under which it is put. Joun HERAPATH. ArmTicLeE IV. Instructions respecting Paratonnerres, or Conductors of Tightning. Extracted from the Report of M. Gay-Lussac, in the name of a Commission appointed by the Royal Academy of Sciences of Paris.* (With a Plate.) Tue principal object of the report (which was drawn up at the request of the Minister of the Interior), is to direct workmen in the construction and mode of fixing conductors on buildings, &c. It is divided into two parts, one theoretical, the other practical. Theoretical Part. Principles respecting the Action of Lightning, or Electric Matter, and of Conductors. Lightning is the sudden passage of electric matter through the air, with the evolution of great light, from clouds highly charged with that fluid ; its velocity is immense, far surpassing that of a ball at the moment it leaves the cannon, and is known to be at the rate of about 1950 feet per second of time. The electric matter penetrates bodies, and traverses their substance, but with very unequal velocities; through some, which are therefore called conductors, it passes with great rapidity ; such are well burnt charcoal and water; vegetables, animals, and the earth, in consequence of the moisture they are oo with, and saline soluticns; but, above all, metals afford the readiest passage to the electric fluid. A cylinder of iron, for instance, is a better conductor than an equal cylinder of water saturated with sea salt, in the ratio of at least 100000 : 1, and the latter conducts a thousand times better than pure water. Non-conductors, or insulating bodies, oppose great resistance to the passage of electricity through their substance ; such are glass, sulphur, the resins, and oils ; the earth, stones, and bricks, when dry; air and aeriform fluids. No bodies, however, are such perfect conductors of electricity as not to oppose some resistance ; which, being repeated in every portion of the conductor, increases with its length, and may exceed that which would be offered by a worse but shorter * From the Annales de Chimie. 428 . M. Gay-Lussac on [Dec. conductor. Conductors of small diameter also conduct worse than those of larger. The electric particles are mutually repulsive, and consequently tend to separate and disperse themselves through space. They have no affinity for bodies, they determine only to their surfaces, where they are retained solely by the pressure of the atmosphere, against which, they in their turn exert a pressure proportionate at every point to the square of their number. When the latter pressure exceeds the first, the electric matter escapes into the air in an invisible stream, or in the form of a luminous line, commonly called the electric spark. The stratum of electric matter on the surface of a conductor is not of equal density at every point of its surface, except it be a sphere. On an ellipsoid the density is greater at the extremity of the great axis than on the equator, in the ratio of the great axis to the smaller; at the point of a cone it is infinite. In general, on a body of any form, the density of the electric mat- ter, and consequently its pressure on the air, is greater on the sharpest or most curved parts, than on those that are flat or round. The electric matter tends always to spread itself over con- ductors, and. to assume a state of equilibrium in them, and becomes divided amongst them in proportion to their form, and principally to their extent of surface. Hence, if a body that is charged with the fluid be in communication with the immense surface of the earth, it will retain no sensible portion of it. All that is necessary, therefore, to deprive a conductor of its elec- tricity, is to connect it with the moist ground. Of several conductors of very unequal powers the electric fluid will always choose the most perfect ; but if their differences be small, it will be divided amongst them in proportion to their capacity for receiving it. A Paratonnerre * is a conductor which the electric matter of the lightning prefers to the surrounding bodies, in order to reach the ground, and expand itself through it: it commonly consists of a bar of iron elevated on the buildings it is intended to pro- tect, and descends, without any divisions or breaks inits length, into water or a moist ground. An intimate connexion of the paratonnerre with the ground is necessary, in order that it may instantly transmit the lightning as it receives it, and thus defend the surrounding objects from its attacks. When lightning strikes the surface of the ground, for want of a good conductor it does not spread over it, but penetrates below it till it meets with a sufficient number of channels to carry it completely off. * J adopt the French term, as we have none in our language to express in one word, a conductor of lightning, meaning thereby not merely the metallic rod, but the whole apparatus complete. At least we may as well use it as parasol, parachute, parabouc, &c.—Tr. 1824.] Conductors of Lightning. 429. It sometimes leaves visible traces of its passage, even at a depth of more than 30 feet. When also a paratonnerre has any breaks in it, or is not in perfect communication with a moist soil, the lightning, having struck it, flies from it to some neighbouring body, or divides itself between the two, in order to pass more rapidly into the earth. Frequent instances of serious accidents have occurred from both these causes. Before the flash ensues, the influence of the thunder cloud disturbs the natural electrical state of all the bodies below it at the surface of the earth, and brings them into a state contrary to its own; and thus every object becomes acentre of attraction towards which the lightning has a tendency to direct itself. In order that this effect may be suddenly produced, it is indispensa- ble that the bodies influenced by the cloud be good conductors, and in perfect communication with a moist soil. 3 A paratonnerre perfectly connected with the ground, and ter- minating in a very sharp point instead of being rounded off, may become so intensely electrified by the influence of a thun- der cloud, as to give otf a continual stream of electric matter, which sometimes 1s visible in the dark, appearing as a luminous pencil at the extremity of the point, and must certainly tend, in part at least, to neutralise the electrical state of the thunder cloud. A rounded point may exert an equal, or even a greater attraction on the thunder cloud than a sharp one ; but if the ow of electric matter from the point become very rapid, the lightning will strike sooner, and from a greater distance between the cloud and the paratonnerre, than ifits extremity were rounded ; at least electrical experiments lead to this conclusion. Thus the most advantageous form that can be given to a aratonnerre appears evidently to be that of a very sharp cone. he higher a paratonnerre is elevated in the air, other circum- stances being equal, the more its efficacy will be increased, as is clearly proved by the experiments with electrical kites, made by MM. de Romas and Charles. It has not been accurately ascertained how far the sphere of action of a paratonnerre extends, but, in several instances, the more remote parts of large buildings on which they have been erected, have been struck by lightning at the distance of three or four times the length of the conductor from the rod. It is calculated by Charles, that a paratonnerre will effectually protect from lightning a circular space, whose radius is twice that of the height of the conductor; and they are now attached to build- ings after that rule. A current of electric matter whether luminous or not, is always accompanied by heat, the intensity of which depends on the velocity of the current. ‘lhis heat is sufficient to make a metallic wire red hot, or to fuse or disperse it, if sufficiently thin; but it scarcely raises the temperature of a bar of metal, on 430 M. Gay-Lussac on (Dec. account of its large mass. It is by the heat of the electric current, as well as by that disengaged from the air, condensed by the passage of the lightning through it when not conveyed by a good conductor, that buildings struck by it are frequently set on fire. No instance has yet occurred of an iron bar, of rather more than half an inch square, or of a cylinder of the same diameter, having been fused, or even heated red hot by lightning. A rod of this size would therefore be sufficient for a paratonnerre, but as its stem must rise from 15 to 30 feet above the building, it would not be of sufficient strength at the base to resist the action of the wind, unless it were made much thicker at that art. : An iron bar, about three-quarters of an inch square, is suffi- cient for the conductor of the paratonnerre. It might even be made still smaller, and consist merely of a metallic wire, pro- vided it be connected at the surface of the ground with a bar of metal, about half an inch square, immersed in water or a moist soil. The wire indeed would pretty certainly be dispersed by the lightning, but it would direct it to the ground, and protect the surrounding objects from the stroke. However, it is always better to make the conductor so large as not to be destroyed by the stroke, and the only motive for substituttng a wire fora stout bar is the saving in point of expence. The noise of the thunder generally occasions much alarm, although the danger is then passed ; it is over indeed on the appearance of the lightning, for any one struck by it neither sees the flash, nor hears the clap. The noise is never heard till after the flash, and its distance may be estimated at so many times 368 yards, as there are seconds between the appearance of the lightning and the sound of the thunder. Lightning often strikes solitary trees, because, rising to a great height and burying their roots deep in the soil, they are true paratonnerres, and their shelter is often fatal to the indivi- duals who seek it; for they do not convey the lightning with sufficient rapidity to the ground, and are worse conductors than men and animals. When the lightning reaches the foot of the tree, it divides itself amongst the conductors that it finds near it, or strikes some in preference to others, according to circum- stances, and sometimes it has been known to kill every animal that had sought shelter under the tree; at others only a single one out of many has perished by the stroke. A paratonnerre, on the contrary, well connected with the ground, presents a certain security against the lightning, which will never leave it to strike a person at its foot, though it would not be prudent to station one self'too close to it, for fear of some accidental break in the conductor, or of its not being in perfect communication with the ground. \ setts \ £2 ter 1824.] Conductors of Lightning. 431 - When lightning strikes a house, it usually falls on the chim« neys, either from their being the most elevated parts, or because they are lined with soot, which is a better conductor than dry wood, stone or brick. The neighbourhood of the fire place is consequently the most insecure spot in a room during a thunder storm, where it is safer to station oneself in a corner opposite the windows, at a distance from every article of iron or other metal of any considerable size. : Persons are often struck by lightning without being killed, and others have been wholly saved from injury by silk dresses, which serve to insulate the body, and prevent the access of the electric matter. PRAcTICAL Part. Details respecting the Construction of Paratonnerres. A paratonnerre is a metallic bar, A BC D EF (Pl. XXXIV), _ fig. 1, rising above a building, and descending, without any breaks, to the ground, its lower end plunging into a well of water, or a wet soil. The vertical part B A is called the stem, and projects into the air above the roof, and the part of the bar BC DEF which descends from the foot of the stem to the soil, is called the conductor. Of the Stem. The stem B A is a square bar of iron, tapering from its base to the summit, in form of a pyramid. For a height of from 20 to 30 feet, which is the mean length of the stems placed on large buildings, the base is about 21 inches square.* Iron being very liable to rust by the action of air and moisture, the point of the stem would soon become blunt, to prevent which a portion, A H, is cut off from the end, A B, fig. 2, about 20 inches in length, and replaced by a conical stem of brass or copper, gilt at its extremity, or terminated by a small platina needle, A G, two inches long.} The platina needle is soldered with silver solder to the copper stem ; and to prevent its sepa- rating from it, which might sometimes happen, notwithstanding the solder, it is secured by a small collar of copper, as seen in fig. 3. The copper stem 1s united to the iron one by means of a gudgeon, which screws into each ; the gudgeon is first fixed in the copper stem by two steady pins at right angles to each other, and is then screwed into the iron stem, and secured there also by a steady pin (see C, fig. 4). If the gilding of the point cannot easily be performed on the spot, nor the platina readily obtained, they may both be dispensed with without any incon- * The best way of making a pyramidal bar is to weld together pieces of iron end to end, about two feet long each, and of successively decreasing diameters. + Instead of the platina needle, one of standard silver may be substituted, composed - of nine parts of silver and one of copper. 432 M. Gay-Lussac on [Duc. venience, and the plain conical copper stem only be employed. Copper does not rust to any considerable depth in the air, and even if the point become somewhat blunt, the paratonnerre will not thereby lose its efficacy. : A stem of the supposed dimensions being difficult to trans- port to a distance, it is cut into two parts AI, I B, fig. 2, at about one-third or two-fifths of its length from the base. The upper part, A D, fig. 4, fits exactly bya pyramidal tenon, D F, seven or eight inches long, into the lower part, E B, and is kept in its place by a pin. The stem should, however, always be made of a single piece whenever that can be done.* Below the stem, three inches from the roof, is a cap, M N, fig. 4, soldered to the body of the stem, and intended to throw off the rain water which would flow down the stem, and prevent its running into the interior of the building, and rotting the rafters. Immediately above the cap, the stem is rounded for about two inghes to receive a split collar, with a hinge O, and two ears, between which the extremity of the conductor of the paraton- netre is fixed by a bolt; the plan of this collar is seen at P below the stem. Instead of the collar, we may make a square stirrup, which embraces the stem closely ; the vertical projection of this is seen at Q, fig. 5, and the plan at R, fig. 6, as well as the mode by which it is united to the conductor. Lastly, in order to save labour, we may solder a tenon, T, fig. 7, in the place of the collar ; but care must be taken not to weaken the stem at this part, where it has to oppose most resistance, and the collar and stirrup are preferable. The stem of the paraton- nerre is fixed on the roof of buildings, according to circum- stances. If it is to be placed above a rafter B, figs. 7 and 8, the ridge must be pierced with a hole through which the foot of the stem passes, and is steadily fixed against the king- post by means of several bridles, as seen in the figure. This disposition is very solid, and should be preferred if local circum- stances permit. If the stem be to be fixed on the ridge at A, fig. 8, a square hole must be made through it of the same dimensions as the foot. of the stem; and above and below we fix, by means of bolts, or two bolted stirrups, which embrace and draw the ridge toge- ther, two iron piates about three-quarters of an inch thick, each having a hole corresponding to that in the woodwork. The stem rests by a smiall collet on the upper plate, against which it is strongly pressed by a nut, which screws on the end of the stem against the lower plate; fig. 9 shows the plan of one of * The hollow part, E G, fig. 4, which receives the pyramidal tenon, D F, is made thus :—A strong iron plate is rolled into a cylinder, and soldered at G to the bar B G ; then by means of a mandrill of the same form as the tenon, and at successive heats, it is easy to unite its edges and to give it, inside and out, the pyramidal shape. + To make the cap, an iron ring is soldered to the stem and drawn out all round on * the anyil, inclining the edges so as to form a very flat truncated cone, 1824.] Conductors of Lightiing. 453. these plates. Butif we can rest against the brace C D, fig. 8, we should solder two ears to tke stem to embrace the upper and lateral faces of the ridge, and descend to the brace, on which they are fixed by means of the boli, E. Lastly, if the paratonnerre be to be fixed on a vaulted roof, it should be terminated by three or four feet, or spurs, which must be soldered into the stone, with lead, in the usual manner. Of the Conductor of the Paratonnerre. The conductor, as has been stated, is an iron bar about three- quarters ofan inch square, B C D EP, fig. 1, or B’C’ D’ EF’ F’, reaching from the foot of the stem to the ground. It is firmly united to the stem, by being tightly jammed between the two ears of the collar O, fig. 4, by means of a bolt; or it may be terminated by a fork M, fig.6, which embraces the tail, N, of the stirrup, and the two pieces bolted together. As the conductor cannot be formed of a single piece, several bars are united end to end. The best method of doing this is seen at fig. 10. The conductor is supported parallel to the roof, at about six inches distance from it, by forked stanchions, which, in order to prevent their letting the rain into the building, are fashioned as follows : Instead of terminating in a point, they have a foot, figs. 11 and 12, formed of a thin plate about 10 inches long, and 12 inch broad, at the extremity of which rises the stanchion, making either a right angle with the foot, fig. 11, ov an angle equal to that which the roof forms with the zenith, fig. 12. The foot slips in between the slates, but for greater firmness a plate of lead is substituted for the lower slate, and the foot of the stan- chion and the lead are nailed down to one of the rafters. ‘The cenductor is kept in the forks by pins rivetted through them, and the stanchions are placed at about 12 feet distance from each other. The conductor, after turning over the cornice of the building, fig. 1, without touching it, is brought into the walls, down which it passes to the ground, and is fixed by means of cramps let into the stone. When it has reached to D or D’ in the ground, about two feet below the surface, it is bent at right angles to the walls in the line D E or D’ EF’, and carried in that direction about 12 or 15 feet, when it turns down into a well, E F, or a hole, E’ F’, about 12 or 15 feet deep in the ground, if no water be met with, but a less depth is sufficient if there be water. The iron buried in the ground in immediate contact with moist earth becomes covered with rust, which, by degrees, penetrates to its centre, and destroys it. This is prevented by -placing the conductor in a trough filled with charcoal, D E, or New Series, vou. Vii. QF 434 . M. Gay-Lussac on [Dec. D’ EF’, which is represented on a larger scale at fig. 13, ~The trough is constructed in the following manner :— ‘ ' Having made a trench in the soil about two feet deep, a row of bricks is laid on their broad faces, and on them others on edge; a.stratum of baker’s ashes (braise de boulanger) is then strewed over the bottom bricks, about two inches thick, on which. the conductor is laid, and the trough then filled up with more ashes, and closed by a row of bricks laid along the top. Tiles, stone or wood, will serve for making the trough, as well as bricks. Iron thus buried in charcoal will undergo no change in the course of 80 years. But charcoal not merely prevents the iron from rusting, for being a very good conductor of electricity, after having been heated to redness (and that is the reason why we recommend the use of baker’s ashes), it facilitates the pas- sage of the lightning into the ground. After leaving the trough, the conductor passes through the side of the well, and descends into the water to the depth of at least two feet below the lowest water line. The extremity of the conductor usually terminates in two or three branches, to givea readier passage to the lightning into the water. If the well be situated in the interior of the building, the wall of the latter must be pierced below the surface of the ground, and the con- ductor passed through it into the well. If there be no well at hand, a hole must be made in the ground with a six inch auger to the depth of 10 or 15 feet, and the conductor passed to the bottom of it, placing it carefully in the centre of the hole, which is then to be filled up with baker’s ashes rammed down as hard as possible all round the conductor. -But if expense be no object, it is better to sink a much wider hole, EH’ F’, at least 16 feet deep (unless water be met with at a less depth), and make the extremity of the conductor terminate in several branches, which must be surrounded by charcoal as before, if not immersed in water, and the conductor itself be similarly surrounded by it, by means of a wooden case filled with the ashes. In a dry soil, or ona rock, the trench to receive the conductor should be at least twice as long as that for.a common soil, and -even longer, if thereby it be possible to reach moist ground. Should the situation not admit of the trench being much increased in length, others, m a transverse direction, must be made as seen at A, figs. 17 and 18, in which small bars of jron surrounded by ashes are placed, and connected with the conductor. In all cases the extremity of the conductor should terminate in several branches, and pass into a wide hole well filled with the ashes or charcoal that has. been ignited. In general the trench should be made in the dampest, and consequently lowest spot near the building, and the water- 1824.] Conductors of Lightning. 435 gutters made to discharge their water over it, so as to keep it always moist. Too’great precautions cannot be taken to give the lightning a ready passage into the ground, for it is chiefly on this that the eflicacy of a paratonnerre depends. As iron bars are difficult to bend according to the projections of a building, it has been proposed to substitute metallic ropes in their stead. Fifteen iron wires are twisted together to form one strand, and four of these form a rope, about an inch in diameter. To prevent its rusting, each strand is well tarred Separately, and after they are twisted together, the whole rope is tarred over again with great care. It is attached to the stem of the paratonnerre in the same manner as the bar-iron conduc- tor, by means of the collar B, fig. 15, the ears of which, in this case, are made rather concave in order better to embrace the rope. Instead ofa fork, the stanchions which support it over the roof, are terminated by a ring, O, fig. 12, through which the rope passes. At about six feet deepin the ground, it is united to an iron bar, about three-fourths of an inch square, in which the conductor terminates as seen at C, fig. 16, for the rope would soon be destroyed in the ground. Bars of iron, however, are preferable to the rope, but if, from peculiarity of situation, it be absolutely necessary to adopt them, copper or brass wire is a better material for their construction than iron. If a building contain any large masses of metal, as sheets of copper or lead on the roof, metal pipes and gutters, iron braces, &c. they must all be connected with the paratonnerre, by iron bars of about half an inch square, or something less. Without this precaution, the lightning might strike from the conductor to the metal (especially if there should be any accidental break in the former), and occasion very serious injury to the building, and danger to its inhabitants. Paratonnerres for Churches. For a tower the stem of the paratonnerre should rise from about 15 to 24 feet, according to its area; the domes and steeples of churches, being usually much higher than the sur- rounding objects, do not require so high a conductor as build- ings with extensive flat roofs. For the former, therefore, thin stems, rising from three to six feet above the cross or weather- cock, will be sufficient, and being light they may easily be fixed to them, without injuring their appearance, or interfering with the motion of the vane. When difficult to fix, the stem of a paratonnerre for such buildings may even be omitted altogether, and merely the foot of the cross or weathercock be well connected with the ground. This arrangement requires little expense, and is well adapted for eountry churches. ‘Bin. 23 represents a steeple without any stem to the paratonnerre, its cross being connected with the 2F2 436 M. Gay-Lussac on [Dec. ground by means of the conductor which is attached to its foot. Fig. 24 is a steeple with the paratonnerre stem fixed to the cross. Churches not defended by a paratonnerre on the steeple, require stems from 10 to 24 feet high, similar to that of a flat building. Fig. 25 represents a paratonnerre so constructed as to be ornamental, with a vane, &c. Paratonnerres for Powder Magazines, These of course require to be constructed with the greatest care, but in principle are perfectly similar to the one we have described at length. They should not be placed on the build- ings, but on poles at from 6 to 10 feet distance, fig. 26. The stems should be abont seven feet long, and the poles of such a height, that the stem may rise from 15 to 20 feet above the top of the building. It is also advisable to have several paraton- nerres round each magazine. If the magazine be in a tower, or other very lofty building, it may be sufficient to defend it by a double copper conductor, A B C, fig. 27, without any paraton- netre stem. As the influence of this conductor will not extend beyond the building, it cannot attract the lightning from a dist- ance, and yet will protect the magazine, should it be struck. A common magazine, or any other building, may be defended ina similar manner, fig. 28. Paratonnerres for Ships. The stem of the paratonnerre for a ship, fig. 29, consists merely of the copper point, A C, fig. 4, already described. It is screwed on a round iron rod, C B, fig. 30, which enters the extremity, I, of the pole of the top gallant mast, and carries a vane. An iron bar, M Q, connected with the foot of the round rod, descends down the pole, and is terminated by a crook, or ring, Q, to which the conductor of the paratonnerre is attached, which, in this case, is formed ofa metallic rope, and is supported at intervals by rigging, gg, fig. 29, and after having passed through a ring, 0, fixed to the chains, is united to a bar or plate of metal, which is connected to the copper sheathing on the bottom of the vessel. Small vessels require only one para- tonnerre; large ships should have one on the mainmast and another on the mizenmast. General Disposition of Paratonnerres on a Building. It is allowed from experiment, that the stem of a paratonnerre effectually defends a circle of which it is the centre, and whose ~ radius is twice its own height, from lightning. According to this rule, a building 60 feet long, or square, requires only a single stem of 15 or 18 feet, raised in the centre of the roof, figs. 14 and 17. In tig. 17, the conductor is a metallic rope. 1824.] Conductors of Lightning. 437 A. building of 120 feet by the same rule, would require a stem of 30 feet, and such are sometimes used ; but it is better, instead of one stem of that length, to erect two of 15 or 18 feet, one placed at 30 feet from one end of the building, the other at the same distance from the other end, and consequently 60 feet apart from each other, fig. 18. The same rule should be fol- lowed for three, or any greater number of paratonnerres. For churches with steeples, although the paratonnerre on the latter must from its great height extend its influence to a con- siderable distance, yet as nothing decisive is at present known from experiment as to the greatest distance to which it may extend, it will be prudent to consider it as only protecting a space, whose radius is equal to the height of its stem above the ridge of the roof, and to erect other paratonnerres, on the roof itself, according to the rule already given (see figs. 19 and 20). General Disposition of the Conductors of Paratonnerves. Although the necessity of establishing a very intimate com- munication between the paratonnerre aud the soil has already been repeatedly insisted on, its importance is such that it may be well to revert once more to the subject. If this condition be not rigorously observed, the instrument will not only become much less efficacious, but even dangerous, by attracting the lightning without being able to convey it to the ground. What other conditions remain to be stated are less important, but nevertheless deserve attention. The lightning should, always be conducted by the shortest possible road from the stem of the paratonnerre to the ground. Agreeably to this principle, when two paratonnerres are placed on a building, and terminate in one common conductor (which is quite sufficient), the point from which its branches diverge to the two stems, should he evenly and at equal dist- ances on the roof between them; the common conductor and its branches may be formed of an iron bar, of the same dimen sions as for a single paratonnerre (see figs. 18 and 19). If there be three paratonnerres on a building, it will be pru- dent to give them two conductors, tig. 20. In general each pair of paratonnerres requires one conductor. Whatever number of paratonuerres be placed on a building, they should all be connected together by establishing an intimate communication between the feet of all their stems, by means of iron bars of the same dimensions as those of the conductors, figs. 20, 21, 22. When the situation will admit of it, the conductor should be placed on the wall of the building most exposed to the rain, which, by wetting it, renders it, though imperfectly, a conduc- tor, and if the conductor of the paratonnerre be not in intimate communication with the ground, it is possible that the lightning 438. M. Gay-Lussac on Conductors of Lightning. [Decy may abandon it for the wet surface of the wall. A further motive for selecting this side of the building is, that the direction of the lightning may be determined by that of the rain, and moreover, the wet surface, being a conductor, may attract the lightning by preference to the paratonnerre. Observations on the Efficacy of Paratonnerres. The experience of fifty years demonstrates that when con- structed with the requisite care, paratonnerres effectually secure the buildings on which they are placed from being injured by lightning. In the United States, where thunder storms are much more frequent and formidable than in Europe, their use is become general ; a great number of buildings have been struck, and scarcely two are quoted as not having been saved from the danger. The apprehension of the more frequent. fall of light- ning on buildings armed with paratonnerres is unfounded, for their influence extends to too small a distance to justify the idea that they determine the lightning of an electric cloud. to discharge itself on the spot where they are erected. On the contrary, it appears certain from observation, that buildings furnished with paratonnerres are not more frequently struck than formerly. Besides, the property of a paratonnerre to attract the lightning more frequently, must also imply that of transmitting it freely to the ground, and hence no mischief can arise as to the safety of the buildings. We have recommended the use of sharp points for the para- tonnerres, as having an advantage over bars rounded at the extremity, by continually pouring off into the air, whilst under the influence of a thunder cloud, a current of electric matter. in a contrary state to that of the cloud, which must probably have some effect towards neutralizing the state of the latter. This advantage must by no means be neglected; for it is sufficient to know the power of points, and the experiments of Charles and Romas with a kite flown under a thunder cloud, to be convinced that if sharp pointed paratonnerres were placed in considerable numbers on Ja.ty places, they would actually diminish the elec- tric matter :i the clouds, and the frequency of the fall of light- ning on the surface of the earth. However, if the point of a paratonnerre should be blunted by lightning, or any other cause, we are not to suppose, because it has lost the property we have mentioned, that it has also become ineffectual to protect the building it is intended to defend. Dr. Rittenhouse relates, that having often examined the points of tlte paratonnerres in Phila- delphia, where they ate very frequent, with an excellent tele- scope, he has observed many whose points have been fused ; but that he never found that the houses on which they were erected had been struck by lightning since the fusion of the points. 1824.] Mr. Daniell’s Reply to X. 439 ARTICLE V. Reply to X. By J.F. Daniell, Esq. FRS. Xc. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Nov. 6, 1824. Tue illustration of your correspondent X. is so extremely apposite, that I at once agree with him in thinking it conclusive. I suppose, with him, “ three barometer tubes standing in a reservoir, and filled alike with mercury, but that one of the tubes expands by heating, that another contracts, and that the third neither expands nor contracts.” But then, I pretend to say (in defiance of the odium philosophorum), that if this apparatus be exposed to various temperatures, the columns in all will not rise to precisely the same height as measured upon their respect- ive tubes. X. does me too much honour in supposing that I am the first who ever used the fraction of the apparent dilatation of mercury for correcting the observed height of the barometer : it has long been known to all those moderately acquainted with the subject, that the expansion of the scale must be taken into account for all nice purposes. ce I trust that X. will not wait for my visit to the Grampian Hills to disclose his method of detecting “the most minute impurity existing in mercury by inspection of a single drop of that metal,” but that he will be induced, for the good of science, to communicate so important a discovery to the Annals of Phi- losophy.* I remain, Gentlemen, faithfully yours, J.F. Danie. ArTICLE VI. Account of a new Mineral Substance. By M. Lévy, MA, of the University of Paris. (To the Editors of the Aznals of Philosophy.) GENTLEMEN, Nov. 10, 1824, You will, perhaps, be able to spare room in the next number of the Annals of Philosophy for a short description of a new mineral substance, which I propose to name Rosélite, in honour of Mr. Gustavus Rose, of Berlin. The only specimen where | have observed it belongs to Mr. Turner’s collection. It occurs in small well-defined translucent crystals of a deep rose colour, on amorphous greyish quartz. # We concur heartily in the wish expressed by our friend Mr. Daniell. (Cs fad P. 440 M. Lévy on anew Mineral Substance. [Dec. The form of the crystals is represented by fig. 2, but the plane marked g" is wanting in most of them. There is a distinct and brilliant cleavage parallel to p, but I could not find any other. The hardness of the substance is about the same as that of car- bonate of lime. The faces a® are dull, and, asit were, hollowed towards the middle: their determination has been deduced from the parallelism of their intersections with the faces 6’. All the other faces are sufficiently brilliant to obtain their incidences by means of the reflecting goniometer. From these incidences, as 4 well as from the different characters of the faces a’, e°, and the occurrence of the face g', without the edge of intersection of the faces a® being replaced, I was enabled to infer that the primitive form was not, as | had thought at first, an octohedron with a square base, but might be supposed to be an octohedron with a rect- angular base, or more simply a right rhombic prism. This last hypothesis I have adopted, and determined the dimensions of the prism by assuming that the faces 6! are the result of a decre- ment by one row on the edges of the base of the primitive. In this supposition the primitive form, fig. ], is a right rhom- bic prism of 125° 7’, in which one side of the base is to the height nearly in the ratio of 13 to2Y. The face a? is on account of the parallelism already mentioned, the result of a decrement 4 by two rows on the angle a of the primitive, and the face e” on account of its incidence on p, the result of a decrement by four rows in breadth and three in height on the angle e. The incidences I have taken as data are, * = p, & = 109° 40’ = p,e” = 112°30" =—B', e* = 129° and I calculated the following, my observations. PD BAY 2a OY BY 79° 15". “pa? = 11S oO. ; m, m= 125° 7’, The specimen comes from Schneeberg, in Saxony, but must ofsextreme scarcity, beivg the only one ever seen-by Mr. : ng which very nearly agreed with Se en ee ee es 1824.] Mr. Children’s Chemical Examination of Roselite. 441 Heuland. Its great resemblance with the arseniate cobalt from the same locality had hitherto caused its being placed with it. —=—— Chemical Examination of Rosélite. By J. G, Children, FRS. In glass matrass, decrepitates and gives off water ; the fine deep rose colour changes to black. With borax, on the platina wire, and in the oxidating flame, the assay dissolves readily, and gives an intensely deep blue glass. In the reducing flame, the colour becomes lighter ; no appearance of reduced copper. With salt of phosphorus on the platina wire, the assay dissolves readily and completely, and gives results similar in both flames to those with borax. The assay dissolves with facility in muriatic acid, and, after evaporation to dryness, the residuum is wholly soluble in water. A minute fragment digested in a solution of caustic potash, on’a slip of glass, evaporated to dryness, redissolved, and the alkali neutralized with nitric acid, gave with nitrate of silver and ammonia, a brown red precipitate of arseniate of silver. Another minute fragment gave with a drop of muriatic acid a fine blue solution; by dilution with water, the colour disappeared. A drop of the diluted solution gave an abundant precipitate with oxalate of ammoniz. Another drop, evaporated to dryness on a polished steel blade, left no trace of copper. Another drop gave with prussiate of potash a yellowish green tint, without any indication of copper. Another drop, treated with bicarbonate of ammonia and phosphate of soda, gave decided evidence of the presence of magnesia. * These experiments are sufficient to show, that the composition of Rosélite consists of arsenic acid, united to oxide of cobalt, _ lime and magnesia, elements which, according to Phillips (Mineralogy, p. 178), constitute the Picropharmacolite of Stro- meyer, who found their proportions to be : WaT G Sy oyck anc het o| abs iecatha tee dit obavebebttes 24°64 MAP TERIA ao 6 iis osm nse seas & aadas to berae Shy Arsénic acid . ......«« ee eee ee CORTE DE COBGIE. ccs awerne wares corre ou AOD Waters: shsise cp eed ocQe 88 oc THs o Oe 99°78 The whole quantity of Ros¢lite that M. Lévy could afford me for my experiments, consisted of three or four minute crystals, about the size ofa small! pin’s head, so that any attempt to ascer- tain the relative quantities of the ingredients would haye been 442 On the rapid Descent of the Barometer in October, [Duc absurd. Judging, however, from the results obtained by the blowpipe, and the appearance of the precipitates, the respective quantities of magnesia in Rosélite and Picropharmacolite, in proportion to those of the lime, must be nearly alike, but that of the oxide of cobalt much greater in the former than in the latter mineral. As the results obtained by M. Stromeyer do not well accord with any probable atomic proportions, some error may, perhaps, have crept in, in the course of his analysis, which even his acknowledged ability may have failed to detect. : ArticLe VII. On the rapid Descent of the Barometer in Oct. 1824. By M. P. Moyle, Esq. (To the Editors of the Annals of’ Philosophy.) GENTLEMEN, Helston, Oct. 30, 1824. Berne struck with the rapid descent of the barometer in the early part of this month, and its accompaniment by a thunder storm, I take the liberty in sending you an extract from my meteorological journal on that occasion, and am, : Geutlemen, your obedient servant, M. P. Moy ez. Barometer, 1824. {corrected to} Ther. |Hyg.| Wind. - ——_ | ———__-_- ee | |) | 9 a, m.| 29'6820 | 55 | 93 | NW |Gentle Very fine 3 p. m.| 29-7127 59 | 82| W |Brisk Showery 10 p.m.| 29°6664 | 58 | 96] W_ Gentle Cloudy Sa. m.} 29-2640 | 56 | 98 | SE |Very brisk/Rain 2p.m.} 28-1160 | 59 | 83 | NW |Ditto Fine 5 p.m.}| 28°9905 | 56 | 86 S_ |Ditto Cloudy 8 p. m.| 28-9007 55 | 91 S_ |Ditto Clear — 10 p. m.| 28:8150 | 54 | 90 S |Stormy {Cloudy midnight] 28°7647 +) 55 SW Stormy {Heavy rain, lightning, &c. Aa. m.| 28-4089 | 57 | 92 | SW |Boisterous |Thunder and lightning 8 a. m,| 28-4976 | 57 -|91 | SW |Ditto © |Showery 11 a. m.| 28°6620 57. |.65 Fresh Slight showers 3 p. m.} 28°7921 48 | 86 Ditto Showery 10 p. m.| 29°1166 | 49 | 93 Very fresh |Showery Ew t ’ i 4 1824.) Mr. Harvey on Naval Architecture. 443 ArTICLE VIII. Observations on Naval Architecture. By G. Harvey, Esq. FRSE. (To the Editors of the Annals of Philosophy.) GENTLEMEN Plymouth, Nov. 6, 1824. ) y In the Annals of Philosophy for October, Col. Beaufoy, with his usual zeal for advancing the naval interests of his country, - has favoured us with a paper on the experimental ships lately built according to the plans of Sir Robert Seppings, Professor Inman, and Capt. Hays;. and has expressed a hope, that this attempt to increase the stock of our information respecting naval architecture, by facts drawn from accurate and unquestionable experiments, may be productive of all the benefits to this import- ant branch of knowledge which the most sanguine of its culti- vators may desire. In this hope | most cordially and heartily join; and so doubtless must every well-wisher of his country. In the same paper, the learned gentleman has also referred to the important subject of the resistance of fluids, and to the advantages likely to result to naval architecture, by the institu- tion of a judicious course of experiments ; and it is to this part of his communication that I wish more particularly to refer on the present occasion. The practical information we possess respecting the resistance of fluids, is unfortunately very limited and confined ; and consi- dering the immense importance of the subject, and the intimate connexion it bears to ship building, it is most singular, that during a period distinguished for uncommon experimental acti- vity, scarcely an effort should have been made to place it on a level with those interesting departments of science to which it is so intimately allied, both from its interesting practical applica- tions, and the fine analytical investigations to which it is likely to give birth. ’ Had the subject been one which individual industry and talent could have successfully prosecuted, there can be no doubt but its complete solution would have been long ago achieved, or at least some large and important steps made towards its completion. But unfortunately, for the sake of science, and, I may add, unfortunately for the naval service of the country also, this is not the case. The problem is one, in the point of view in which Col. B. is probably desirous of contemplating it, involving too many difficulties for an individual to contend with, unless that individual possessed talents of the highest order, uninterrupted leisure, and the necessary command of money ;— three elements, I believe, not often united in the same person; and as the past has not afforded a fortunate example of the 444 ‘Mr. Harvey on Naval Architecture. [Dec. kind, we may almost fear the future will not be more pro- pitious. This great problem, with all its important applications, may, therefore, always remain in its present imperfect condition, unless the necessary funds for its investigation be atforded b the country; and judicious and proper persons be selected for its investigation. It is not indeed too much for the man of science to expect, that some steps at least should be taken towards its completion, when he reflects on the national benefits likely to result from it, by the new aspect it would give to naval architecture, and the important practical rules that would most probably be deduced, to improve the form and the sailing quali- ties of our ships of war. We may hope indeed, from the liberal spirit which now animates our Public Boards, and from the various improvements which have been latterly introduced into our dock yards, that the difficulties which have hitherto impeded the march of this important branch of knowledge, may be in some degree surmounted ; and by a steady perseverance, that all the elements of the problem may be crowned with a perfect and satisfactory solution. {In speaking of this important branch of knowledge, I would not be understood to overlook the splendid efforts which have been already made by mathematicians, to enlarge and extend its boundaries. On the contrary, I cannot too much admire the attempts of that noble race of men to increase our stock of information on the subject, in spite of the clouds and difficulties which surround it. Talents indeed of the most splendid order have been engaged on it; the most beautiful and varied inven- tion has been displayed, and the richest treasures of analysis been unfolded, to elucidate the theories which have been from time to time advanced. Mathematicians, however, have not failed from lack of talent, or want of ardour, to pursue the ques- tion in all its bearings, but for want of experimental data on which to ground their investigations. It cannot be concealed, that there are difficulties in the way of this problem, which no calculus can reach, however refined may be its principles, or however ample and extended may be its powers, unless exper?- ment previously furnishes its properly corrected elements. With these, the mathematician would be enabled to work with the same certainty and success as distinguish his efforts in so many other departments of physical science. Nor can it be till then that ship building can assume a character suited to the genius and scientific intelligence. of the age. No longer the sport of accident, and guided by rules, if rules they may be called, which have no other authority and foundation than what an imperfect experience has afforded, we shall see it gradually assuming a new aspect; and instead of having to contemplate —— 1824.] Mr. Harvey on Naval Architecture. 445. the immense variety of external forms, which our harbours and naval arsenals now present, we shali find every ship pos- sessing a figure adapted precisely to her class, and to the pecu- har purposes for which she was primarily intended.* With respect to the proper mode of conducting such experi- ments, supposing the undertaking to be sanctioned by the Admiralty, one of the dock yards would of course be selected from the numerous facilities which such an establishment must: afford. But no little consideration would be necessary in the selection of the proper persons to conduct the investigation. Practical knowledge alone would be insufficient ; nor would the highest theoretical skill be all that would be required. The two must be united,—cordially and harmoniously united. Practice must not decline the assistance of theory, nor must theory disdain to be taught by the lessons of practice ; and every result must be deduced from as wide and as extended a basis, as the maturest con- sederation may deem proper. It is truly of importance to improve to the utmost the sailing qualities of our navy, and the money that may be bestowed on it, cannot be more properly employed. At present few fixed or determinate principles exist on the subject; and various inte- resting problems present themselves for investigation on its first consideration. The best figure of the bow, so as to. unite every necessary and proper quality for dividing the fluid in which it moves with the necessary capacity for stowage, has never been determined ; nor has the figure or position of the middle section been discovered ; and it is not too much to say, so far as the practical details of the subject are concerned, that at the present moment al/ is darkness and uncertainty ; and in darkness and uncertainty the subject must remain until such experiments are undertaken. Some experimental attempts have indeed been made to elucidate the problem, and to give something like a practical aspect to its investigation; but they have been either. too limited or confined, or too little attention has been bestowed on some of its most essential conditions. Amidst the general efforts for improvement that are now tak- ing place, the improvement of the sailing qualities of our ships of war, and of the vessels of our mercantile marine, is of para- mount importance. By the former, as Colonel Beaufoy has judi- ciously observed, a colony may be conquered, or a valuable settlement saved, by the celerity of the ships employed in the expedition ; and for the latter, it may be added, swiftness of * I exempt from this censure the efforts that have been made by Sir Robert Seppings to improve naval architecture; since every one conyersant with the subject must be aware, that the introduction of the diagonal trusses, the improved bows, and circular sterns, mark the first dawn of scientific improvement in our dock yards. The opposi- tion, however, that the introduction of his plans experienced, proves the truth of the observation in the text; and nothing but his cornmanding talent and power enabled him successfully to surmount it. 446 Mr. Moyle on the Temperature of Mines. [Dec. sailing, combined with the proper capacity for stowage, is of no less importance. At no antecedent period did so many ships navigate the uncertain bosom of the deep. Every nation almost is aiming ata maritime character, and the sea is become one of the high roads of civilization. To the first maritime people on earth, the improvement of naval architecture addresses itself with peculiar force, and with higher claims to attention, than any other, EORGE HARVEY. ArTICLE IX. On the Temperature of Mines. By M. P. Moyle, Esq. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Helston, Oct. 30, 1824. In consequence of my having communicated to the Annals some experiments and remarks on the temperature of mines, involving the disputed subject as to the natural heat of the in- ternal strata of the earth, I conceive that your readers are entitled to whatever additional proofs I may be enabled to advance in support of my original opinion, although it forms the substance of a paper read before the Royal Geological Society of Cornwall at their last anniversary meeting. Perhaps the minds of most of your readers have been made up as tothe probability of one cr the other theory, de- duced from the experiments already detailed in the Annals, and which have been tried in this county within the last two or three years. I shall in the first instance endeavour to prove the dubiousness of the one conclusion in a tenfold degree over that of the other, for the high temperatures observed at the bottom of mines, must be, and indeed is, acknowledged on all sides, much influenced by local causes, not easily got rid of, or allowed for ; whereas, on the other hand, the low degrees of heat somé- times met with, seems to be beyond the pale of uncertainty ; and if we can adduce a solitary instance only of temperature not exceeding the annual mean of the climate, at a considerable depth below the surface of the earth, and more particularly beneath the level of the sea, I shall be apt to infer a difficulty insurmountable by my opponents. I would suggest that in all endeavours to elucidate this sub- ject, our main object, in proving the correctness of either theory, should be in obtaining the coldest situations possible, instead of those possessing a high temperature, for the presence of work- men, the boring and blasting of rocks, the burning of candles, &e, together with the lengthened column of the atmosphere, must much influence the latter cause, while no operation with 1824.] Mr. Moyle on the Temperature of Mines. 447 which we are acquainted, but that of evaperating, can by any pos- sible chance controul the first. Hence if a low temperature is met with, it would seem to be 2 more true criterion of the actual state of the earth generally than we could possibly infer from occasional instances of high temperature, because, were the internal strata of the earth augmented in temperature according to the descent, the emanation of whose caloric is said to be sensible in our mines, a low degree of heat could in no one instance occur. The act of boring holes in the solid rock at the bottom of the mine, or in any other situation, to observe the temperature, must be fallacious ; unless the hole is bored to a considerable depth, and in the course of the lode, so that a body ‘of water shall issue ina full and powerful stream through it.. The heated air of the spot must penetrate, and the sides and bottom of the hole soon acquire the same temperature as the external walls of the gallery itself. This circumstance I have so often proved, that [ have always omitted the results as being deceit- ful. The only way in which this experiment can succeed, so as to supply a true data appears to be in the manner just stated, with the proviso that the end of an extensive gallery, or some other situation, is chosen the most remote from any working part, and far beyond the perpendicular from the galleries which lie above it as at A. B the perpendicular shaft. cccc are various galleries. Bt eeu — <1 SUSIE? PE aon fi eae nj Ee a Now if a hole is bored horizontally at A, on the course of the lode, and so as to allow a full stream of water to pass through it, it will be less liable to be influenced by the percolation of the water from the galleries above it ; whereas should it be done in any part at D, and there should exist a solid barrier of earth ‘from that place to the gallery above it, the water which ‘lodges at the bottom of the superincumbent gallery generally ‘finds its way perpendicularly to D, and consequently must bring with it a medium temperature of what it possessed before, an ‘that of the stratum of earth through which it has passed, while the water at A most probably will be free from all these objec- tions. ; Bearing in mind these circumstances, I shall proceed to detail a few experiments which I performed in the course of the last 448 Mr. Moyle on the Temperature of Mines.’ {Dec. summer, and to which i referred in my last communication.* I there stated the temperature of Oatfield engine shaft 182 fathoms from the surface, to have been whilst at work 77°, and in a few months after that period, when this part had ceased working, and all below was full with water, to be only 66°, and the water at 12 fathoms in depth 67°. This mine has now been relinquished for many months, and on sinking a registering thermometer, properly secured, as in my former experiments, to precisely the same depth, the temperature was found to be only 54°, and this degree of heat was uniform throughout the water. Thus adding to the number before given of the confor- mity of temperature throughout relinquished mines, and evinc- ing upon the grounds before stated} that did the earth in reality possess a natural and a greater heat, the temperature of 54° could not exist. I also stated the temperature of the water in the then relin- quished mines of Herland and Huel Alfred, the former 54°, and the latter 56°. The reworking of these mines hassince taken place, and the following are the experiments made on the occasion. The water in Herland engine shaft, being drained 20 fathoms below the adit, making 52 fathoms from the surface, was found to be 58°, while at 8 or 10 fathoms below the surface of the water, it was still 54°. The mud in a gallery at this level was also 54°, while the air was, as in the shaft, 58°. Experiments of this nature were tried as opportunities occurred in the drain- ing of this mine. Few of the galleries could immediately be penetrated to any considerable distance on being first exposed, in consequence of being choked from various causes ; but in no one instance was the mud found to exceed 56° of temperature, where immediate access could be had, and previously to the approach of workmen; while the air of the galleries generally approached to within 1° of that in the engine shaft. The surface of the water in the shaft gradually increased in temperature as it descended, so that after having drained 100 fathoms of water, it was found to be 66°, while at 10 fathoms in depth it still retained its former standard of 54°. Experiments of precisely a similar description were carried on at Huel Alfred from its recommencement, They had in September last accomplished the draining of more than 100 fathoms in depth, and no oppor- tunity was lost in proving, by every possible method, the accu- racy of the experiments, because they appeared to differ in some respects from those of Herland. Huel Alfred was formerly found to be at all depths 56°, two degrees above the water in the old engine shaft at Herland, but on an equality with another. ® Annals, vol. vy. p. 34, N. S. + Ibid. CE ee ee oC ee) el Be, Be 1824.] Mr. Moyle on the Temperature of Mines. 449 Most of the levels, &c. were tried in a similar manner to what has just been stated, and the mud was always found to be 56°, so also was the water 8 or 10 fathoms below its surface. The surface of the water in this mine as well as the air never exceeded 59° throughout its descent, being only an increase of 3°, although the water was originally 2° warmer than that of Herland, while Herland increased 10° in draining to the same depth. The reason for this appears to arise from the rapidity with which Huel Alfred engines raised the water in comparison with that of the other. Huel Alfred doing more in one month than Herland did in five or six, consequently the surface of the water. in the shaft had less time to be exposed to the operation of local causes. I caused two holes to be bored in the lode at Huel Trumpet tin mine ; one in the end of the 80 fathoms level, and the other in the 94 from the surface. They were each two feet in depth, and so situated that the water should flow through them. These spots were selected because they yielded the greatest quantity of water, and because they extended to the greatest distance, and consequently most free of all the levels from the draining of the water from the superincumbent ones. The 80 extended many fathoms beyond the deeper one, and yielded its water in a very powerful stream through the hole. The temperature of this water at the bottom of the hole was only 52°, and that. at the 94 under similar circumstances, was 56°. A short intermediate gal- lery was in full work, and no doubt influenced the temperature of the water in the one below, as all the water of this gallery was found to enter the ground, and doubtless filtered to the one beneath. . If further proof was required as to the similitude of tempera- ture soon acquired by water, it may be found in Capt. Parry’s late voyage to the north, where he tried the temperature of the sea at various and considerable depths. In lat. 59°26 he sunk a registering thermometer to the depth of 2100 feet, and the tem- perature was found to be 502°, precisely similar to what it indi- cated at and near the surface, while the air was 53°. Having now adduced so many instances of temperature at and near the annual mean of this climate, and that at considerable depths even below the sea level, I leave it to be confuted, or to have a clear demonstration why those low degrees of heat should exist. ] am, Gentlemen, your obedient servant, M. P. Moye. New Series, vou, vit. 2c 450 M. Berzelius on Fluoric Acid.: [Dec. ARTICLE X. On Fluoric Acid, and its most remarkable Combinations. 3 By Jac. Berzelius. (Continued from p. 343.) : Il. Compounds of Fluoric Acid with Acids or Electronegative Oxides. Tue fluoric acid is distinguished from every other by its pro- pensity to combine with the weaker acids in such a manner that the latter act as bases; and these compounds again unite with the fluates of the electro-positive oxides, and form with them double salts. These peculiar salts of fluoric acid and the electro- negative oxides are farther characterised by this circumstance, that, when in a similar degree of saturation, they are partially decomposed by water ; an acid solution being formed, while the negative oxide precipitates in an msoluble state, either uncom- bined, or in union with a smaller quantity of fluoric acid.. During these decompositions, a portion of water combines with the acid, and there is obtained in fact a double salt, im which water acts the part of a base; this water again may be displaced by any of the more energetic bases, and a new double salt is formed, in which both of the bases are metallic oxides. In all cases where, after the decomposition ofa neutral fluate by water, an acid fluate remains in solution, we may remark in the latter a strong tendency to form a double salt, by the substitution of a different basis for the water. Perhaps a similar property may be possessed by the neutral salts of other acids, which are in a similar manner decomposed by water: it is not the case, how- ever, with the salts of antimony and bismuth, from which water produces an almost complete precipitation of the oxides. We have long been aware that fluoric acid in union with silica forms a distinct class of salts with the alkalies, such as potash and barytes ; but the nature of these compounds has been hitherto misunderstood. In what follows, I shall demonstrate, that although characterised by peculiar properties, they are funda- mentally analogous with the fluates of the saline bases. A. Fluate of Silica, or Silicated Fluoric Acid, and its Combina- tions with the Salhne Bases. The circumstance that silica and fluoric acid have been found existing together in certain combinations, has caused them to be regarded as constituting, while in that situation, a double acid, capable of uniting with bases, and forming with them a class of compounds to which [ applied the provisional name of fluosili- cates. In reality, however, this compound must be regarded as a fluate of silica, for unless it undergo a previous decomposition, li i i 1824.] M. Berzelius on Fluoric Acid. 451 in which a portion of the silica is separated and replaced by some other basis, which may be either an alkali, an earth, a metallic oxide, or even water, it is incapable of entering inte combination with any other substance except a neutral fiuate. I have kept the gas in contact for many days with the pulverised carbonates of potash and soda, without the slightest absorption eusuing ; and a similar result was obtained with lime and with the bicarbonates of potash, although I expected that the water of crystallization of this salt might have facilitated the combina- tion, On the contrary, the pulverised fluates of the alkalies, earths, and metallic oxides, even when anhydrous, instantly absorb the gas, and become saturated with it at the end ofa few hours. Consequently the fluoric acid and silica, when asso- ciated in the proportions which constitute the gas, have no ten+ dency to combine with an additional quantity of base; and the class of salts styled fluosilicates, instead of being combinations of a fluate with a silicate, are combinations of fuate of silica with the fluates of different bases. Quantitative Composition of Fluate of Silica.—The silica preci- pitated by water from this compound is so voluminous, and is moreover so decidedly soluble in water, that it is impossible to conduct an analysis by this process with any degree of precision. The most advantageous method appeared to be to precipitate the fluoric acid and silica by soda, im the state of the difficultly soluble salt, and afterwards to separate by double decomposition the silica which remains dissolved in the liquid; but this pre- supposes a knowledge of the double salt, which would obviously render a separate analysis of the gas superfluous. After ascer= taining this necessary preliminary, | proceeded to the analysis in the following manner: A quantity of water was impregnated with the gas, until it became converted into a thick coagulum. During the process, the liquid was incessantly agitated, and care was taken to prevent it from ever coming in contact with the conducting tube. The mixture was now thrown upon a filter, and the silica was washed until the filtered liquid ceased to redden litmus paper. Ignited, it weighed 1:263 gramme. No trace.of fluoric acid is expelled during the ignition. I con- sider it necessary to mention this circumstance, because Gay- Lussac and Thenard’s experiments might lead to the supposi- tion, that the silica separated by water from the gas is in combi- nation with a smaller proportion of fluoric acid. The filtered acid liquid was mixed with carbonate of soda as long as it effer- vesced, and the double salt which precipitated was collected upon a balanced filter, washed, and dried in a balanced platinum crucible. It weighed 8°99 grammes, and is equivalent to 3°053 grammes of fluoric acid, and to 2°994 grammes of silica, provided we make the calculation from my former number for the atomic weight of that substance, which, however, is a little 2e@ 2 452 M. Berzelius on Fluoric Acid. [Dec. too high. The remaining liquid, together with the last washings of the silica, was supersaturated with carbonate of soda, mixed with a solution of carbonate of zinc in ammonia, and evaporated nearly to dryness. The silica by being thus combined with oxide of zinc, was not only rendered insoluble, but was reduced to so condensed a state that it could be easily washed. The silicate of zinc, after having been kept in contact for some time with hot water, was transferred upon a filter, and washed. It was then dissolved in nitric acid, the solution was evaporated to dryness, and the residue was digested in acidulated water. The silica, which now remained undissolved, weighed, after ignition, 1-297 gramme. The alkaline liquid filtered from the silicate of zinc consisted of a mixture of carbonate and fluate of soda. It was saturated nearly but not completely with acetic acid, and evaporated to dryness. The object of not rendering it fully neutral was to avoid the possible dissipation of fluorite acid during the evaporation. The dry mass was treated with a mix- ture of alcohol and acetic acid, in erder to extract the slight residue of carbonate of soda, and the fluate of soda obtained by this means in a state of purity, was ignited. It weighed 2-912 grammes, equivalent to 0°787 gramme of fluoric acid. Conse- quently the whole fluoric acid amounted to 3°053 + 0°787 = 3-84 grammes, which-had been combined with 5:554 grammes of silica; that is, in the fluate of silica, 100 parts of fluoric acid are combined with 144°6 parts of silica. This number, as will be subsequently shown, is not strictly accurate, yet it is a suffi- cient approximation to demonstrate that in this compound, the atomic weight of the fluoric acid has to the atomic weight of the silica the same relation which it has to that of the base in all neutral fluates. One of the objects of this analysis was to ascertain the pro- portion of silica which is separated from the gas by the action of water; but the considerable quantity of this earth which is dissolved by the water employed in washing it prevented me from placing any confidence in my direct experimental results. I had recourse, therefore, to the liquid which separates sponta- neously from a saturated aqueous solution of the gas, as it was obvious that from a comparison of its composition with that. of the gas, it would be easy to infer the amount of silica which is deposited. If this liquid be accurately saturated with carbonate of potash, nearly the whole of the acid and silica are precipitated in the state of the insoluble double fluate of silicate and potash, and the remaining fluid, when evaporated to dryness, is fund to contain only a mere trace of the same compound. A still more complete precipitation is oktained when the liquid is mixed with an excess of muriate of barytes: here the whole of the acid and silica are precipitated in the state of the double fluate of silica and barytes, and the supernatant fluid contains nothing except ——_ "Ss eee ee 1824.] M. Berzelius on Fluoric Acid. 453 uncombined muriatic acid and muriate of barytes. If the same experiments be made with the dilute acid which is washed from the silica, a similar precipitation of the double salts is obtained, but the remaining liquid uniformly gelatinizes when concentrated, in consequence of the presence of the dissolved silica. Conse- quently. the gas is converted by the action of water into a liquid acid, in which the fluoric acid and silica exist in the same rclae ' tive proportions as in the insoluble double salts of fluoric acid and silica with potash or barytes. This proportion, as will be subsequently demonstrated, is such, that one-third of the silica is separated and replaced by water. It is obvious, therefore, that this acid can be obtained pure only when concentrated, and that in proportion as the filtered acid liquid becomes diluted, the greater will be the excess of silica which it will hold in solution, I consider these experiments to have demonstrated: lst, That in the gaseous silicated fiuoric acid, the acid and silica contain equal quantities of oxygen, that is, 3 atoms of acid are combined with 2 atoms of silica; and 2dly, That in the formation of the liquid acid, one-third of the fluoric acid loses its silica, and com- bines with water ; that is, it is composed of 3 atoms of hydrous Jluoric acid and 2 atoms of fluate of silica.* Water absorbs this gas at first with great avidity, but the pro- cess becomes more and more tedious, in proportion as the mobi- lity of the liquid is lessened by the deposition of silica. On exposing to the gas a very small quantity of water, 0°1835 grm. in a small balanced glass vessel over mercury, I found that about 48 hours elapsed before absorption had completely ceased. It had now entirely lost its fluidity, and smoked slightly when exposed to the air. The increase of weight was 0:258 gramme ; consequently 100 parts of water are capable of absorbing 140-6 parts of the acid gas, or, by abstracting the 27°65 parts of silica which are deposited at the instant of the absorption, 112-95 parts of the liquid acid. Ihave made many attempts, but unsuccess- fully, to obtain the acid in its highest degree of concentration, * That the latter part of each of these enunciations may be understood, it may be necessary to state that Berzelius considers fluoric acid to be composed of | atom of fluo- ricum (70°34) + 2 atoms of oxygen (200) = 270°34; and silica, of ] atom of silicium (277) + 3 atoms of oxygen (300) = 577. The compound of fluoric acid and silica which he styles the fluate, is that in which the acid and base contain equal quantities of oxygen, or in which 3 atoms of acid are combined with 2 atoms of silica. A much less complicated view of the constitution of these two compounds may be taken by consider- ing, with Dr. Thomson, the atomic weight of fluoric acid to be represented by one-half, and that of silica by one-third, of the numbers adopted by Berzelius. On this supposi- tion, the gas would be composed of | atom of fluoric acid + 1 atom of silica; and the liquid acid, of 2 atoms of this simple fluate + 1 atom of hydrous fluoric acid. The for- mule by which Berzelius represents the composition of these two compounds are 3 Fs and 3 F Aq + 2 S$? F3. The formula by which they would be represented in confor- mity with the numbers of Dr. Thomson, are SF, and 2S F + ¥ Aq. 454 M. Berzelius on Flioric Acid. (Dec. that is, containing no water, except the quantity which acts the part of a base. Thus I have distilled the silicated fluate of harytes with concentrated sulphuric acid, but there was disen- gaged at the commencement of the process a large quantity of the gaseous fluate of silica, which gelatinized in water, and towards the conclusion, there passed over an acid liquid, which consisted in a great measure of concentrated fluoric acid. Even the silicated fiuates, such as those of copper or nickel, which contain much water of crystallization, afforded similar results. The dilute acid may be concentrated by evaporation, but after it attains a certain degree of strength, it begins to evaporate in an equal proportion with the water: it may also be concentrated over sulphuric acid in vacuo, but long before it acquires the above-mentioned strength, it evaporates along with the water, and corrodes the receiver. The best method of obtaining this acid in a state of concentration is to add finely pulverised silica in small quantities at a time to fluoric acid, diluted with twice or thrice its weight of water, and artificially cooled. It dissolves the silica readily until it attains the composition of the liquid acid; what it takes up beyond this point is immediately after- wards dissipated in the form of gas. When the double silicated fluates which contain water of crystallization are exposed in a glass vessel in so high a temper- ature that the fluate of silica begins to be expelled, there is obtained a white sublimate which might be readily mistaken for an ammoniacal salt, but which, when examined by a micro- scope, is found to consist of transparent drops. This liquid may be distilled unaltered from one part to another so long as the vessel is filled with the gaseous fluate of silica, but it deposits silica as soon as the gas is replaced by atmospheric air. It requires a pretty high temperature for volatilization. ‘There is a particular degree of concentration which the liquid acid uniformly acquires when exposed for some time to the air ; when weaker than this, the excess of water evaporates; when stronger, it very rapidly absorbs moisture from the atmosphere. Ina temperature of about 104°, it slowly evaporates without leaving any residue, and towards the conclusion of the evapora- tion, it deeply corredes any glass vessel in which it may have been kept. The gaseous fluate of silica is rapidly absorbed by alcohol without decomposition, but as soon as the liquid becomes nearly saturated, it stiffens to a clear transparent jelly. The alcohol when saturated contains more than half its weight of the gas, and has an odour of ether. Petroleum also absorbs the gas unaltered, but only in small quantity. The liquid silicated fluoric acid combines with all the bases, and forms with them peculiar salts. I have subjected to a regu- lar analysis the double salts of potash, soda, barytes, and lime, 1824.] M., Berzelius on Fluoric Acid. 455 and found the constituents in them all to be combined in similar proportions. I believe, therefore, we may conclude, that all the double salts obtained by saturating bases with this acid possess an analogous constitution. I shall here state the details of these analyses. The analyses of the salts of soda and barytes are the most easily executed, and afiord the most decisive results. Silicated Fluate of Soda.—a. 100 parts, decomposed by sul- phuric acid, gave 74°85 parts of sulphate of soda = 32°844 parts of soda. The sulphate of soda dissolved in water without leay- ing any residue, and was exactly neutral. b. 100 parts dissolved in boiling water were slightly supersaturated with carbonate of soda, and the liquid was mixed with an excess of a solution of carbonate of zincin ammonia. The whole was now evaporated until the ammonia was expelled, and the silica was separated in the manner which has been already described. It weighed, after being ignited, 316. c. The filtered alkaline liquid was evaporated nearly to dryness ; the excess of carbonate of soda was saturated with acetic acid, and the acetate of soda was separated by alcohol. The fluate of soda, isolated by this means, weighed, after ignition, 134 parts. As 32°844 of sodais equivalent to 44°2 of neutral fluate ofsoda, and as 44-2 x 3 = 132°6, it follows that in the double salt the soda is associated with thrice as much fluoric acid as is requisite for its neutraliza- tion. It is impossible by this analytical process to separate the silica completely; hence the quantity indicated by the experi- mental result is always rather Jess than the truth, while, on the contrary, that of the fluate of soda is slightly in excess. Silicated fluate of barytes, when ignited in a glass retort, gives a trace of the sublimate already mentioned, which consists of water supersaturated with the acid gas. The expelled gas does not corrode glass, and therefore contains no disengaged fluoric acid. a. 100 parts of the salt, in two successive experiments, left, after ignition, 62°25, and 62:26 parts of fluate of barytes. Consequently the fiuate of silica which had been expelled, amounted to from 37°74 to 37°75 parts. 6, 100 parts, decom- posed by sulphuric acid, gave 82°933 parts of ignited sulphate of barytes. Silicated Fluate of Polash,—-100 parts were converted by sul- pliuric acid into 78°85 parts of sulphate of potash = 42-634 otash. Silicated Fluate of Lime.—100 parts gave with sulphuric acid 63°69 parts of sulphate of lime; and by strong ignition, 36:2 parts of fluate of lime. Both these quantities represent 26-4 parts of fluate of lime. 100 parts were incorporated with 600 parts of oxide of lead, covered with an equal quantity of the oxide, and exposed to a low red heat. The mixture fused, and gave off 16:25 parts of water. Consequently this salt contains 456 M. Berzelius on Fluoric Acid. [Dec. a quantity of water of crystallization, whose oxygen is double that of the lime. In other respects, the composition of all these salts is strictly analogous. The composition of these double salts affords a simple expla- nation of a phenomenon which at first appears very paradoxical. If a solution of superfluate of potash or soda be digested with as much silica, as is sufficient to saturate the excess of acid, it loses altogether its acid reaction, and becomes alkaline. This reac- © tion, however, is not occasioned directly by the silica. The excess of acid in the salt is exactly sufficient to form a silicated fluate of potash or soda with one-half of the neutral fluate: in proportion, therefore, as this excess combines with silica, the double salt precipitates, while the other half of the neutral fluate, which remains in solution, exhibits its characteristic alkaline reaction. Zeise had already shown, that a similar change is produced upon the acid fluates by boracic acid. The double fiuates of silica with the other bases have all an acid bitter taste, which in most instances cannot be distin- guished from that of cream of tartar, They all redden litmus paper, and the greater number of them are soluble in water. The only difficultly soluble salts which I found, were those of potash, soda, lithia, barytes, lime, and yttria. Many contain water of crystallization, and a few of them fatiscerate.* In a high tem- perature they all undergo decomposition, gaseous fluate of silica being expelled, while a neutral fluate of the stronger base remains. Ifthe salts contain water of crystallization, it passes off along with the fluate of silica, and there is obtained a con- centrated liquid, silicated fluoric acid, which deposits silica when it comes in contact with water. ‘The quantity of water of crystallization may be determined by heating the salts along with oxide of lead, in which experiment there is formed an actual fluosilicate of the oxide. This compound is so remarka- “bly fusible, that it becomes liquid in a temperature below a visible red heat, particularly when the ingredients are propor- tioned with some exactness. The aqueous solutions of these double salts are all of them decomposed by alkalies. The alkaline salts are decomposed in such a manner, that the silica is precipitated, while the acid with which it had been combined remains in solution, in the state of a neutral fluate. From the earthy salts the earth is precipitated in the state of fluate, mixed or combined with the * This term is applied by Berzelius to certain compounds containing water of crystal- lization, which lose a determinate quantity of it, but not the whole, when exposed to a temperature considerably under 212°. ‘Thus citric acid, sulphate of ammonia, oxalate of ammonia fatiscerate, when exposed to a low heat, losing by this treatment exactly one-half of their combined water. ee eS ee ee ee 1824.] M. Berzelius on Fluoric Acid. 457 silica, whose acid remains in solution. From the salts of the earths proper, and of the metallic oxides, the base is precipi- tated in the state of a bisilicate, while the whole of the fluoric acid remains dissolved, in combination with the alkali. Even when the metallic oxides are soluble in ammonia, a determinate pertion of them is carried down by the silica. When the solu- tions of certain of these salts are mixed with a less quantity of acid than is requisite to produce complete decomposition, pecu- liar subsalts are precipitated, but I am uncertain whether these are mixtures of silica with a subfluate, or actual fluosilicates, in which the same base is shared between two acids. In most cases I prepared these salts by digesting the liquid acid -over the carbonate or hydrate of the base, until it was nearly saturated : the solution was then concentrated to a cer- tain point in a flat platinum capsule, and allowed to crystallize of its own accord in a temperature between 64° and 68°. When the gelatinous silica on the filter has been pretty thoroughly washed, so large a portion of it is dissolved, that the solution of the salts prepared from the liquid acid not unfrequently gelati- nizes during concentration. This excess of silica may be redis- solved by the addition of a few drops of pure fluoric acid, and the compound thus formed is volatilized by the subsequent eva- poration in the form of gas. Fluoric acid does not decompose these double salts, and when the mixture is evaporated to dry- ness, the whole excess of acid flies off, and leaves the salts unaltered. Sulphuric acid instantly acts upon these double salts, and disengages gaseous fluate of silica: the decomposition is ren- dered complete by the application of heat, and there is expelled at the same time a quantity of liquid acid, which rapidly attracts moisture from the atmosphere. The salts of lime and barytes are not decomposed by sulphuric acid, except in temperatures above 212°. Nitric and muriatic acids decompose these double salts only partially. On the contrary, the liquid silicated fluoric acid, in the humid way, completely deprives these acids of the bases with which it forms difficultly soluble con pounds ; in other cases the decompositions which it also produces are only partial. (To be continucd.) 458 Dr. Fitton’s Additional Remarks. [Dec ‘ARTICLE XI. Additions to a Paper in the last Number of the Annals of Phi- losophy. By William Henry Fitton, MD. FRS. MGS. &c. (To the Editors of the Annals of Philosophy.) GENTLEMEN, 20th November, 1824. I sHALL be much obliged by your inserting the following paragraphs connected with my paper in the Axnals of Philoso- phy for the present month, if possible, in the ensuing number of your journal, that they may be placed in the same volume with the paper to which they refer. I remain, Gentlemen, your obedient humble servant, Wixriiam Henry Firron. I had stated in a memoir read at the Geological Society during the last Session,* before I had examined the Isle of Wight, that I was indebted to Mr. Lyell, one of the Secretaries of that body, for complete evidence of the identity of the greenish beds below the chalk between Beachy Head and Sea-Houses, in Sussex, with what I have denominated Firestone, at Culver in the Isle of Wight; and in your last number (p. 381), [ have men- tioned my obligation to the same gentleman for a section of the beds below the chalk at Shiere, near Guildford, in Surrey. I was not then aware, nor was | till Mr. Lyell’s return to London during the last week, fully informed upon this subject, that his observations in the Isle of Wight were more extensive than I at first supposed; since he had not only found at Sandown Bay the calcareous nodules inclosing univalves, which I have mentioned (p. 374), but had deduced from his observations the same inferences respecting the real order of the strata below the chalk, and their correspondence in the isle of Wight with those of Kent and Sussex, as I have been led to, by considering the features of the surface, and by subsequent examination of the strata. Mr. Lyell’s observations were communicated by letter to Mr. Mantell, of Lewes, so far back as in July 1822; and during a tour in the Isle of Wight in the spring of 1823, with the Hon. H.G. Bennett and Prot. Buckland, Mr. Lyell pointed out upon the spot to those gentlemen the facts on which his views were founded: which, as they accord with most of the essential points that I have mentioned, would no doubt, if followed up, have led to the same results—Had I been informed, as I am at present, of these circumstances, I should unquestionably have mentioned them in my paper; and I now think it is due, both * 19th June, 1824.—See p. 67 of the present yolume. 1824.] Dr. Fitton’s Additional Remarks. 459 to Mr. Lyell and to myself, to acknowledge unequivocally the priority of his observations and deductions. I take this opportunity also of correcting an omission of importance, and some errata in that part of the table at the end of my paper, which refers to Prof. Sedgwick’s valuable memoir in the Annals of Philosophy for May, 1822.* The first three divisions of the column under Mr. Sedgwick’s name should stand thus :— Beds as they exist in the Isle of Wight. Sedgwick. ] . CHALK, with Aints. | bohalk. without flints. grey (marly). “ Indurated chalk marl.” bluish. 2. Greenish sand and sand- | In the Isle of Wight, “ green- stone, with chert.( fvrestone.) sand.” In Cambridgeshire, “a very thin bed of tenacious blue clay, which is mixed with greensand, and contains a great many fossils.”. — 3. Clay of the undercliff. | In the Isle of Wight, consi- (Gault.) dered as the same with the weald-clay, No. 5. In Cambridgeshire, “ tena- cious blue clay. (Gault.)” I fave intimated in the concluding paragraph of my paper (p. 383), the probability that the order of the strata now recog- nised in the Isle of Wight would serve to clear up the obscurity, in which some other districts, consisting of the beds below the chalk, have been hitherto involved ; and it is obvious, that as the firestone has been frequently confounded with the lower beds, and the Hastings sands with the upper ferruginous portion of the greensand,—and the gault with the weald clay, it will be ne- cessary again to examine the strata to which any of these names have been applied, for the purpose of deciding upon their true relations.—It seems to be highly probable, from Mr, Smith’s geological maps of Berkshire, Oxfordshire, Bucking- hamshire, and Bedfordshire, that a part at least of what has * Mr. Sedgwick has himself been so obliging as to point out these inaccuracies in the Table, which were, in part, occasioned by an oversight of the person who transcribed the paper for the press. ‘I'he order of the beds in the vicinity of Cambridge, corresponds precisely with that of the Isle of Wight and of Sussex. 460 Dr. Fitton’s Additional Remarks. been denominated “ iron sand,” in those counties, and regarded. as the equivalent of the Hastings-beds, belongs in reality to the greensand of the Isle of Wight: since the outcrop of the chalk . is continued without interruption through the tract just men- tioned, with firestone in several places immediately below; and a bed of clay is also represented as being continuous and pa- rallel to the chalk throughout,—with the sands contaiming “ carstone,” likewise in continuity, immediately beneath it :— just as in the counties of Surrey, Kent,-and Sussex.* It deserves inquiry, therefore, whether that part of the range of sands passing through Oxfordshire, which shoots beyond the © general line to Shotover Hill, may not also belong to the green- sand ;—the Tetsworth-clay in the same county, which has generally been considered as the equivalent of the weald-clay, being expressly identified by Mr. Smith with the gault of Cam- bridgeshire.—In Buckinghamshire, the sand below the gault is continued towards the north-east, from Thame to Woburn, but the true nature of the portions which are most remote from the gault seems more doubtful; and some of these may possibly be referable to the Hastings sands.—In Bedfordshire, the sands adjoining the gault would seem to belong to the Shanklin- beds; but the place of some detached portions of clay, in the midst of the sands of this county, corresponds with that of the weald-clay, and would consequently lead to the expectation of the true Hastings strata on the north-western verge of this sandy district—In Norfolk, the tract of sand which extends with an irregular outline from near Downham to the sea at Hunstanton, ranging nearly parallel to the chalk, and bearing upon it several detached portions of blue clay with the cha- racteristic belemnite of the gault (see Smith’s map), seems to be referable to the Shanklin sands.—In Lincolnshire from Spilsby to near Barton, a similar remark may be applied.—And in the south-east of Yorkshire, the long range of the chalk from the north bank of the Humber to the shore on the south of Filey Bay, is succeeded by sands, and these again by clay, the true relations of which are still to be ascertained. An examination of the Ordnance Surveys, and of the geolo- gical maps of the south-eastern counties, Wiltshire, Dorsetshire, and Devon, in which the structure of the surface is more com- * [have had occasion to remark, that the local division of the beds in Mr. Sinith’s county maps, is generally correct, in that part of the series which is at present under consideration.—But unfortunately his names and colours are not always applied with consistency ; and his erroneous identification of the green-sand of Kent with the Port~ land sands, and of the Kentish rag with the Portland limestone, has caused his boundaries of the strata also to be considered as erroneous, and thus diminished the usefulness of a very valuable publication. The bed which I have traced in the text from Berks to Cambridgeshire, under the name of gau/t, and which is so denominated in Mr. Smith’s county maps, is, in his reduced map of England, named oak trec-clay, and identified with the weald-clay of Kent and Sussex. Dr. Fition’s Additional Remarks. 461 plex, will make it evident that a great deal is still to be deter« mined respecting the beds below the chalk in those districts.— “And since it is probable that a greater consistency of structure than has hitherto been suspected will be found to pervade the whole of the extensive tract now mentioned, even this rapid view of what remains to be done, will show how much there is to reward inquiry in this department of the geology of England. It has been suggested to me, irom different quarters, that the terms upper and /ower greensand would be preferable, for the denomination of the beds which I have named firestone and greensand ; and that these two strata, together with the inter- vening gault, might form one group, in the general arrangement, under the name of “the greensand formation.” But the mis- application of the term greensand has really been the source of so much confusion, that 1t seems much better to give it up alto- gether, and to choose for the beds in question names entirely new.—I know indeed that some of the principal geologists in England concur in this opinion. And the propriety of group- ing together the firestone and greensand is also doubt- ful:—because the firestone beds are not in general separated from the chalk by any well marked natural feature, but pass into the Jower part of it almost insensibly. They sometimes, -it is true, project beyond the foot of the chalk escarpments so as to form a sort of step or lower plateau, as at St. Catherine’s Down in the Isle of Wight ;—but there never is between the two strata a well defined valley, such as that which contains the gault, and separates the firestone from the greensand,—a natural and characteristic feature that is seldom wanting. It may be added in support of this objection, that the French naturalists consider the firestone as a variety of the chalk itself, and have named it accordingly craie-tufau, glauconie-cra- yeuse, &e. I have employed the term firestone to designate the beds above ailuded to, merely for the purpose of distinction; but it is, perhaps, objectionable, inasmuch as the true firestone forms a part only of the beds to which the name of the stratum is intended to refer, and is probably not coextensive with the stratum itself-—The principles of geological nomenclature seem to require, that significant terms derived from external characters should be avoided; since, from the great diversity of composi- tion and appearance which exists in the same stratum in different districts, such terms are very seldom correctly applicable to any great extent :—Of this the greensands, as they have been hitherto denominated, afford a remarkable proof.—The best names, therefore, at present in use, are either those (like gault and lias), which are insignificant themselves, but locally em- ployed, in districts where the strata with which they are con- 462 Dr. Fitton’s Additional Remarks. nected are strongly characterised and well defined—or those derived from the names of places, where the beds are fully dis- played and have been sufficiently examined:—as in the case of the Portland limestone, the Purbeck beds, and the Hastings sands. Iam upon the whole disposed to prefer denominations of the last mentioned description, since the very terms them- selves point to the types in which the characters of the strata are best exhibited ; and if the place which furnishes the name be easy of access, geologists will find no difficulty in’ recurring to the standard, for the purpose of verification, in doubtful cases. From these combined considerations, | should propose to distinguish all the strata which form the subject of my last communication by different names ; and, for the present, not to group them together. And as the firestone beds are well dis- played at Merstham, near Reigate, a place within a few hours’ journey from London, while the cliffs at Shanklin and its vicinity, in the Isle of Wight, exhibit very distinctly almost every form of what has been called greensand,—in a district which must always be interesting to geologists,—I would suggest the adoption of the following series of names, with the hope of preventing ambiguity in future :— Proposed names of the Synonymes. strata. 1. Chalk ........ Including chalk with and without flints— (the crate blanche of the French) and grey chalk—chalk marl of Mr. Webster. 2. Merstham beds . Firestone —Greensand of Mr. Webster, Isle of Wight.—Tuffeau.—Craie-chloritée or Glauconie-crayeuse of the French.* 3. Gault......... Folkstone-mari.— Blue marl of Mr. Webster in the Isle of Wight.—Golt-brick-earth of Smith’s county maps.—Tetsworth-clay? 4. Shanklin sands. Greensand—commonly so called.—Upper part of the ferruginous sands of Mr. Webster.—G/lauconie crayeuse ? 5. Weald clay.... (By some considered as the same with the clay of YVetsworth, which, however, is probably the gault ?) 6. Hastings sands. Iron sands—Lower part of the ferrugi- nous sands of Mr. Webster, I. of Wight. * The presence of chert is mentioned by Mr. Brongniart as characteristic of the craie-tufau: but the relations of the Glauconie-crayeuse are rendered doubtful by what the same author has mentioned of its separation in some cases from the Tufau by a bed of bluish clay marl. (See Ann. des Mines, i. 254-5, 257-8, and vi. 550, 547 ; or the translations in Mr. De la Beche’s “ Selections,” &c. 1824.) 1824.] Mr, Whipple’s Reply to Mr. Phillips. 463 ARTICLE XII. (To the Editors of the Annals of Philosophy.) GENTLEMEN, FEELING extremely anxious that my reply to Dr. Fitton should be inserted in the Annals of this month, I am sorry to find that your previous arrangements have rendered that impos- sible. Since several geologists are concerned in the question, and may write upon the subject, I trust that my reply will find a place in the next number, and that your readers will suspend their judgment until they read my paper, which is connected only with that by Dr. Fitton already published in your last. I am, Gentlemen, yours, &c. T. WEBSTER, . ARTICLE XIII, Answer to Mr. Phillips’s Observations on the London Pharma- copata. By Mr. G, Whipple. (To the Editors of the Annals of Philosophy.) GENTLEMEN, Loudon, Aug. 1), 1824. IN reply to a few of the hints given in the Annals of Philoso- phy for June, by way of improvement en the formule constituting the New London Pharmacopeeia (1824), I should esteem it an obligation, if favoured with a translation of the first nineteen lines of the paper, the parvum in multo. On the formula for the preparation of sulphate of potash, the writer of the paper is most fatally mistaken. In my opinion, the College have acted most judiciously in directing that the excess of acid be saturated with potash, instead of lime, for, in this instance, they employ. a salt of a very inferior value to obtain one of a greater, (and, by the bye, of some considerable importance to every manufacturing chemist), and, therefore, contrary to the opinion of the writer (of that paper), who says, “The College would have acted economically in imitating the directions of the Edinburgh Pharmacopeeia, ‘by saturating the excess of acid of the bisulphate, with lime instead of potash ; by this the waste would have been avoided of using a salt of greater value to obtain one of less.” A single importunity to any of the drug warehouses will convince him of his error. Moreover, I would ask, since economy be the maximum on which he has founded his examination, whether this salt could not be more 464 Proceedings of Philosophical Societies. [Dec. economically obtained by employing potash in the process for forming the ferrum precipitatum. To attempt a definition of his remark on the preparations of iron, would be Aguam arare, wherefore I shall be obliged, if favoured with information, as to its abstract tendency. What must be the inference of an assertion like the following? “That in the preparations of iron, there have been some alterations which are to be considered as amendments ; but I am apprehen- sive that the good which has been done is more than counterba- lanced by the omission of improvements, or the commission of errors.” Surely, if in the formula, that is, such as have been altered, amendments have taken place, how can we ascribe to the College a want of ability, or the commission of error? My remark relative to the ferri subcarbonas, will be seen in the note on sulphate of potash. The acidum aceticum fortius diluted with water does not answer for the purpose of making the liquor plumbi subacetatis. I have frequently tried it, and ever been unsuccessful, for as soon as it assumes the density, as required in the Pharmacopeeia, it becomes opaque, which cannot be removed by filtration. Anticipating the insertion of this paper in the Annals of Philosophy, by the which an elucidation of the several paradoxes complained of may be obtained,* I remain very respectfully, Gentlemen, Your most obedient servant, G.WHIPPL FE ArtTIcLeE XIV. Proceedings of Philosophical Societies. ROYAL SOCIETY. Tus Society re-assembled on the 18th of November; when Douglas C. Clavering, Esq. Capt. R. N. was admitted Fellow, and the Croonian Lecture, by Sir E. Home, VPRS. was read: it related to Mr. Bauer’s discovery ofnerves on both the foetal and maternal surface of the Placenta: a paper, by the same author, as also read, On the Changes undergone by the Ovum of the wFrog, during the production of the Tadpole. We shall give some account of these papers in the next number of the Annals. LINNEAN SOCIETY. The first meeting of this Society for the present session took place on Nov. 2; when W. J. Broderip, Esq. was admitted ee shall probably take some notice of this communication in the next Number.— 1824.} Geological Society. 465 Fellow, and a paper was read, On three Species of Birds, one hitherto undescribed, and the others new to the Ornithology of the British Islands; by N. A. Vigors, Jun., Esq. FLS. We shall present a report of this paper in our next. GEOLOGICAL SOCIETY. Nov. 5.—A paper was read entitled “ Observations on a Comparison between the Beds below the Chalk in the Isle of Wight, and in the Counties of Surrey, Kent, and Sussex ;” by Thomas Webster, Esq. Sec. G.S. Mr. Webster stated, that in a late visit to the Isle of Wight, he had been so fortunate as to discover a rock of the same nature as the calciferous sandstone of Hastings, a circumstance that has furnished him with a fixed point, by means of which he had been enabled to compare the beds in the Isle of Wight with those of the south-east part of England more correctly than had been done before ; and he presented a table of what he consi- dered as the equivalent beds in these two places. He imagined that these equivalents had been hitherto stated erroneously by several geologists ; and he attributed this chiefly to the follow- ing causes :—I|st, The imperfect state of the science of geognosy which had not as yet established fixed principles of classifica- tion: 2dly, The want of acknowledged types or beds or forma- tions, to which all other parts might be referred: 3dly, The difficulties attending actual examinations, arising from the defi- ciencies or want of continuity of some beds, and the variatiomin the composition and structure of others; difficulties which had, in his opinion, been underrated, The author then proceeded to point out in detail what he conceived to be the history of some of the errors that had been falleninto. Thus, until lately, the descriptions given by various geologists of the rock called green sand were supposed to be applied to one bed only, whereas, in fact, there are two beds dis~ tinct from each other, the undercliff of the Isle of Wight, and the rock of Folkstone, each of which had received this denomi- nation. Also in the groups which it had been found necessary to form, they had not agreed with each other as to the indivi- dual beds enclosed in one group. Thus, some had formed a group (which they called the ferruginous sand) of the sands above and below the weald clay; while others had attached the name of ferruginous sand to those below the weald clay only. He had also reason to fear, that an error had been committed in not identifying the beds which are called the ferruginous sand, on the west of the chalk, as the Carstone, Wobourn sand, and the Faringdon bed, with the beds in the wealds of Kent and Sussex to which the name of green sand had been given. New Series, vou. Vitt. 24H 466 Proceedings of Philosophical Societies. [Dec. The following is the table of equivalent beds above alluded to : Q Localities in the Isle Localities in the SE| Names proposed for (_ & of Wight. part of England. | the Equivalent Beds. < —— — none Culver Cliff. Guildford, Chalk with flints. 7) = at a = a Ditto. Ditto. Chalk without flints. : 5, — _ = o om Ditto. Ditto. Chalk manl. P Undercliff. Riegate, Merstham,| Upper green sand. and Beachy Head. ' — — 7 | Ea mt wt ae | 2 8 Redcliff, Atherfield, Folkstone, Leith Hill,| Lower green sand, o ee and Blackgang. &c. ferrugino-greensand, Sandown Bay and Wealds of Kent and Weald clay. 7 Brixton Bay. Sussex. 2 — onee oa — Q: Cowleaze Chine. Hastings. Hastings limestone, | +4 Guiiéen. Brook nas Hastings and Fair- | Hastings sandstones r 5 Point, light. and clays. 5 aE = = = Isle of Purbeck. Purbeck beds. J Isle of Portland. Portland beds. Nov. 19.—A paper was read, “ On the Purbeck and Port- land Beds;” by T. Webster, Esq. Sec. G. 8. The author observed, that the great general features of the ecology of the Isle of Purbeck had been already traced out by him in his letters to Sir Henry Englefield. He now confined himself to some details respecting the series of limestone beds in the Isle of Purbeck, and to those in the Isle of Portland. He then proceeded to give a description of the strata from which the well known Purbeck stone used in London, for side pavements, &c, is derived. This stone is composed almost entirely of fragments of shells. ‘The Purbeck marble contains chiefly univalves in a compact limestone, and these im general are smaller than the univalves in the Petworth marble, both hav- ing been supposed to belong to freshwater shells; but the author possessing specimens that contain a mixture of marine with freshwater shells, he cannot consider this as a decided freshwater formation, a term that, in his opinion, ought to be restricted to those beds supposed to have been formed in /akes only. The common Purbeck stone appears to consist of frag- ments of small bivalves, of which the origin is doubtful. Mr. Webster then gave a detailed account of the quarries in the Isle of Portland, which furnish the Portland stone much 1824.] Scientific Notices—Chemistry. 467 ‘used in our public buildings. The Isle of Portland consists ofa mass of limestone lying upon a bed of bituminous clay and limestone identical with the Kimmeridge beds. The lower and more considerable part of the limestone in the Isle of Portland above the Kimmeridge clay, is chiefly oolitic, and contains beds of chert; but the upper part consists of a yellowish calca- reous stone nearly compact, which contains in it a bed of earthy lignite abounding in silicified portions of trunks of trees, about two or three feet in length, some of which are erect, and others lie flat. As far as he could ascertain, the fossil wood was nearly confined to this stratum, and is not dispersed through the oolite as had hitherto been supposed. These upper beds of the Isle of Portland he considered as belonging to the same forma~ tion as the Purbeck beds, having found some very similar in the Isle of Purbeck. ' Considering the fossil shells of the Portland oolite to be marine, while those of the Purbeck limestone are chiefly fresh- water, together with the great difference in the mineralogical character, the author stated his opinion that these two series of beds should be kept in separate groups in classing the English strata. ARTICLE XV. SCIENTIFIC NOTICES. CHEMISTRY. 1, Minerals produced by Feat. It has been very often observed, that the analyses of minerals are of comparatively little value, as long as we are not capable of reproducing by composition what had been dissolved. Prof. Mitscherlich has accomplished this important object. We have been gratified by the sight of beautiful and well-defined crystals of greyish white pyroxene, which had been obtained by mixing the constituent parts indicated by analysis in the necessary proportion, and exposing this mixture to the high degree of heat of the porcelain furnaces of Sevres. By this means, Prof. Mitscherlich has succeeded in obtaining several species that occur in nature. He has likewise observed among the different kinds of slags more than forty species in a crystallized state, yarticularly of such minerals as are found in primitive rocks, but Me wire a good many others which have not hitherto been observed. We propose giving in our next number a full state- ment of the further details of these most important experiments. —(Edin. Jour. of Science.) 2. Berzelius’s Analysis of the Sulphato-tri-carbonate of Lead. This eminent chemist, in analyzing some specimens of this 2u2 2u 2 468 Scientific Notices—Mineralogy. [Dec. interesting mineral, sent to him for this purpose by Dr. Brews- ter, obtained the following results : Carbonate of lead ...... PEE Le ar ie sulphate of lead .........5.4e0s PPV AY 1:9) CRUE NE oT POO RE a fatielmmriting = 1 Aa eek RPE any Wiih. ip Mega Rae betcha i 10 = 101-1 In the letter with which M. Berzelius has favoured us on this subject, he remarks, that his result accords with that of Mr. Ir- ving, of Edinburgh, who found the carbonate of lead to be 73, and the sulphate 29, giving an excess of 2-°0.—(Edin. Phil. Jour. vol. vi. p. 388.) He hkewise remarks, that as he had an excess of 1-1 of weight of the stone, it is probable that a part of the oxide of lead in it is in the form ofa subsalt. ‘ The result,” he adds, “‘as it is, dces not agree with the definite proportions ; and the small quantity of the mineral did not permit me to make ulterior experiments.” Mr. Brooke, in his analysis, makes the results agree perfectly with the definite proportions (Edin. Jour. iii. 118), viz. about 72:5 of carbonate, and 27:5 of sulphate of lead. He had no excess of weight, and did not observe either the trace of muriatic acid or of lime.—(Edin. Jour. of Science.) MINERALOGY. 3. Localities of Scottish Minerals. In No. 2 of the Edinburgh Journal of Science, Dr. Maccul- loch has given a list of localities of some Scottish minerals. Among these several of the substances which formerly belonged to the zeolite family, are incorrectly named. Under Stilbite Dr. M. includes a red mineral from Kilpatrick Hills, and a colourless or slightly tinged substance found at Strontian, These minerals differ essentially from each other in their specific characters. The first is described in Phillips’s Mineralogy, under the name of Heulandiie, and the second as Brewsterite. In reference to Comptoniie, Dr. M. says, “ If this be a new mineral, it is the supposed stilbite of Strontian;” that is, it is not anew mineral. But if Dr. M. had ever examined Compéon- ite, and compared it with Brewsterite, he would have found sufficiently marked distinctions between them to have prevented his confounding them with each other; and he would also have ascertained that Comptonite differed from every other kuown mineral. Among the localities of Nadelstein, Dr. M. refers to Kilpa- trick Hills, and he also includes under this species the natrolite from Staffa. it is evident that Dr. M. has looked-at this tribe of minerals 1824.) Scientific Notices—Mineralogy. 469 very cursorily, or he could not have erred so widely as he has in arranging them under the heads in which they stand in his list. Is he not aware that natrolite and mesotype are the same mineral, and that the Kilpatrick mineral differs both from mesotype and from nadelstein, and has received the designation of T’homsonite. Had this list proceeded from less authority in these matters than Dr. M. we should not have noticed its inaccuracies. But we consider that by thus correcting it, we are rendering a service to mineralogy. 4. On the Pyro-electricity of Minerals, Haiiy gave the following list of pyro-electrical minerals, with the names of those who first noticed their pyro-electrical pro- perty : Tourmaline ............ Lemery. GPS tists wis.