u. * • 1- THE LONDON, EDINBURGH, and DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF SCIENCE. CONDUCTED BY SIR DAVID BREWSTER, K.H. LL.D. F.R.S.L.&E. &c. RICHARD TAYLOR, F.L.S. G.S. Astr.S. Nat.H.Mosc. &c. RICHARD PHILLIPS, F.R.S.L.&E. F.G.S. &c ROBERT KANE, M.D. M.R.I.A. " Nee aranearum sane textus idee- melior quia ex se fila gignunt, nee noster vilior quia ex alienis libamus ut apes." Just. Lifs. Polit. lib. i. cap. 1. Not. VOL. XXIII. NEW AND UNITED SERIES OF THE PHILOSOPHICAL MAGAZINE, ANNALS OF PHILOSOPHY, AND JOURNAL OF SCIENCE. JULY— DECEMBER, 1843. LONDON: RICHARD AND JOHN E. TAYLOR, RED LION COURT, FLEET STREET, Printers and Publishers to the University of London; SOLD BY LONGMAN, BROWN, GREEN, AND LONGMANS J CADELL; SIMPKIN, MARSHALL AND CO. J S. HIGHLEY ; WHITTAKER AND CO.; AND SHERWOOD, GILBERT, AND PIPER, LONDON : BY ADAM AND CHARLES BLACK, AND THOMAS CLARK, EDINBURGH J SMITH AND SON, GLASGOW; HODGES AND SMITH, DUBLIN: AND G. W. M. REYNOLDS, PARIS. The Conductors of the Philosophical Magazine have to acknowledge the editorial assistance rendered them by Mr. Edward W. Brayley, F.L.S. F.G.S., &c. Librarian to the London Institution- CONTENTS OF VOL. XXIII. NUMBER CXLIX.— JULY, 1843. Page Captain James's Remarks on the Variegated Appearances of the New and Old Red Sandstone Systems 1 Dr. Kane on the colouring Matters of the Persian Berries .... 3 Prof. J. R. Young's Demonstration of the Rule of Fourier. ... 6 The Rev. Brice Bronwin on the Problem of Three Bodies 8 Prof. Johnston on the Sugar of the Eucalyptus 14 Mr. W. J. Cock on Palladium— Its Extraction, Alloys, &c 16 Dr. Liebig on the Formation of Fat in the Animal Body 19 Mr. W. Kemp's Observations on the latest Geological Changes in the South of Scotland 28 Mr. M.J. Roberts on the Analogy between the Phenomena of the Electric and Nervous Influences 41 Notices respecting New Books : — Mr. Noad's Lectures on Che- mistry, illustrated by 106 Wood-cuts 45 Proceedings of the Royal Society 47 Geological Society . . 57 Chemical Society 71 New Analyses of the Cymophane (Chrysoberyl) of Haddam, by M. A. Damour 77 Action of Nitric Acid on Carbonate of Lime, by M. Barreswil 78 Meteorological Observations for May 1843 79 Meteorological Observations made at the Apartments of the Royal Society by the Assistant Secretary, Mr. Roberton; by Mr. Thompson at the Garden of the Horticultural Society at Chiswick, near London; by Mr. Veall at Boston; by the Rev. W.Dunbar at Applegarth Manse, Dumfries-shire; and by the Rev. C. Clouston at Sandwick Manse, Orkney .... 80 NUMBER CL.— AUGUST, Dr. R. D. Thomson's Examination of the Cowdie Pine Resin. . 81 The Rev. B. Bronwin's Reply to Mr. Cayley's Remarks 89 Dr. R. Hare's Additional Objections to Redfields Theory of Storms 92 Dr. Pring on a Method of Etching on Hardened Steel Plates and other Polished Metallic Surfaces by means of Elec- tricity 106 Series of Propositions for rendering the Nomenclature of Zoo- • f IV CONTENTS OF VOL. XXIII. Page logy uniform and permanent, being the Report of a Com- mittee for the consideration of the subject appointed by the British Association for the Advancement of Science 108 Mr. Murchison on the Geological Structure of the Ural Mountains 124 Proceedings of the Royal Irish Academy 135 , . Royal Astronomical Society 145 On the Variation of Gravity in Ships' Cargoes in different La- titudes ' 154 On Olivile, by Mons. A. Sobrero 156 On some new Combinations of Cyanogen, by Mons. A. Meillet 157 Meteorological Observations for June 1843 159 Table 160 NUMBER CLL— SEPTEMBER. Dr. Draper on the Decomposition of Carbonic Acid Gas and the Alkaline Carbonates, by the Light of the Sun ; and on the Tithonotype 161 Dr. O'Shaughnessy on the use of Lightning-Conductors in India, with reference to a passage in Mr. Snow Harris's work on Thunder- Storms 177 Mr. A. Kemp's new Process for preparing Cyanogen 179 Dr. D. D. Owen, Mr. Lyell, Dr. Mantell, Mr. W. C. Redfield, and Mr. J. H. Cooper on the Geology and Palaeontology of North America, in abstracts of a series of papers recently communicated to the Geological Society of London 180 Mr. Bray ley on the Geographical Distribution of the Megathe- rium 193 Mr. W. G. Armstrong's Account of a Hydro-electric Machine constructed for the Polytechnic Institution, and of some Ex- periments performed by its means 194 Letter from Dr. Hare on Professor Daniell's Defence of the view taken by the latter of certain Electrolytic experiments, which have been represented as proving the existence of a compound radical (oxysulphion) in certain sulphates 202 Mr. W Brown on the Storms of Tropical Latitudes 206 Mr. J. D. Smith on the Composition of an Acid Oxide of Iron (Ferric Acid) 217 Experiments and Observations on Moser's Discovery, by Messrs. Prater and Hunt 225 Observations on M. Millon's Memoir on Nitric Acid, by M. Gay-Lussac 23 1 On the Action of Chlorides on Protochloride of Mercury, by Mons. A. Larveque 233 CONTENTS OF VOL. XXIII. V Page Scientific Memoirs, Part XII. — Mr. Babbage's Analytical En- gine 234 Meteorological Observations for July 1 843 239 Table 240 NUMBER CLIL— OCTOBER. Prof. C. G. Mosander on the new metals, Lanthanium and Didy- mium, which are associated with Cerium ; and on Erbium and Terbium, new metals associated with Yttria. 241 Prof. Wartmann's Experiments on the mutual relations of Electricity, Light and Heat 254 Mr. Joule on the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat 263 Mr. W. Brown on the Storms of Tropical Latitudes {concluded) 276 Dr. L. Playfair on the Changes in Composition of the Milk of a Cow, according to its Exercise and Food 281 Mr. Drach's Places of Saturn computed by Hansen' s Formula 298 Proceedings of the Geological Society 300 Royal Astronomical Society 311 On the non-precipitation of Lead from solution in Sulphuric Acid by Hydrosulphuric Acid, by M. Dupasquier 314 Halo round the Sun, seen by Mr. Veall, Boston 316 Crystallization of Octahedral Iodide of Potassium, by M. Bou- chardat 317 On the presence of the Sulphate of Tin in the Sulphuric Acid of commerce, by M. Dupasquier 317 On the Oxidizing Action of Chlorate of Potash on Neutral Sub- stances 318 New Books 319 Meteorological Observations for August 1843 319 Table 320 NUMBER CLIII.— NOVEMBER. Dr. R. D. Thomson on the Results of the Panary Fermentation, and on the Nutritive Values of the Bread and Flour of dif- ferent countries 321 Dr. J. M. Winn on the Production of Heat by the Contraction of Elastic Tissue 326 vi CONTENTS OF VOL. XXIII. Page Mr. T. Everitt od the Leaf-stalks of Garden Rhubarb as a Source of Malic Acid 327 Dr. Stenhouse's Examination of Astringent Substances 331 Mr. J. W. Stubbs on the application of a new Method to the Geometry of Curves and Curve Surfaces 338 Mr. Joule on the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat (continued) 347 Prof. Ludwig Moser on the so-called Calorotypes, with Ani-.^^y madversions on the Papers of Mr. Hunt and Prof. Draper lately published in the Philosophical Magazine 356 Sir W. R. Hamilton on an Expression for the Numbers of Ber- noulli, by means of a Definite Integral ; and on some con- nected Processes of Summation and Integration 360 Mr. E. Solly's Note on the Changes in Colour exhibited by So- lutions of Chloride of Copper 367 Proceedings of the Royal Society 368 Chemical Society 385 On a Change produced by Exposure to the Beams of the Sun, in the Properties of an Elementary Substance, by Prof. Dra- per, of New York 388 Account of Clegg's Differential Dry Gas-light Meter, by Prof. Vignoles, C.E. ' 388 Action of Sulphurous Acid on Metallic Oxides 397 Extraction of Palladium in Brazil 398 On the Influence of Temperature on the Production of Iodo- form, by M. Bouchardat 398 Meteorological Observations for September 1843 .... ..... 399 Table 400 NUMBER CUV.— DECEMBER. Dr. Draper's Description of the Tithonometer, an instrument for measuring the Chemical Force of the Indigo-tithonic Rays 401 Mr. R. Hunt on the Spectral Images of M. Moser ; a Reply to his Animadversions, &c 415 Dr. Stenhouse on Theine and its Preparation 426 Mr. Joule on the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat (concluded) 435 Professor Grove's Experiments on Voltaic Reaction 443 The Rev. W. Bruce's Occasional Notes on Indications of the Barometer and Thermometer during Stormy Weather at Belfast, from November 1833 to January 1843 446 Prof. J. It. Young's New Criteria for the Imaginary Roots of Numerical Equations 450 CONTENTS OF VOL. XXIII. Vll Page Notices respecting New Books : — 1 . Philosophical Theories and Philosophical Experience. 2. Connection between Physio- logy and Intellectual Philosophy. 3. On Man's power over himself to prevent or control Insanity 452 Proceedings of the Geological Society 457 Royal Astronomical Society 472 On the Composition of Pechblende, by M. Ebelman 475 On the Composition of Wolfram, by M. Ebelman 477 On the Products of the Decomposition of Amber; by Heat, by MM. Pelletier and Philippe Walter 477 Meteorological Observations for October 1843 479 Table 480 NUMBER CLV.— SUPPLEMENT TO VOL. XXIII. Mr. W. C. Redfield on Dr. Hare's " Additional Objections" relating to Whirlwind Storms 481 Mr. R. W. Fox's Notice of some Experiments on Subterranean Electricity made in Pennance Mine, near Falmouth ...... 49 1 Mr. J. D. Smith on the Constitution of the Subsalts of Copper. — No. I. On the Subsulphates 496 Mr. W. Beetz on the Spontaneous Change of Fats 505 Mr. J. T. Cooper on Improvements in the Instrument invented by the late Dr. Wollaston, for ascertaining Refracting In- dices 509 Proceedings of the Geological Society 512 On the Phosphorescence of the Glow-worm. 543 Action of Potassium and Sodium on Sulphurous Acid, by Messrs. Fordos and Gelie 545 Action of Zinc on Sulphurous Acid, Sulphite of Zinc, by Messrs. Fordos and Gelis 545 Index 547 Vlll CONTENTS OF VOL. XXIII. PLATE, Illustrative of Captain James's Paper on the Variegated Appearances of the New and Old Red Sandstone Systems. Errata. Vol. XXII. Page 464, paragraph 81, line 4, for cathion read anion. Present Volume. P. 274, line 2 from the bottom,/or B C, C D, &c, read B C, D E, &c. THE LONDON, EDINBURGH and DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF SCIENCE. [THIRD SERIES.] JULY 1843. I. Remarks on the Variegated Appearances of the New and Old Red Sandstone Systems. By Captain James, Royal Engineers, F.G.S., $c.* [Illustrated by Plate I.] TJTAVING in company with Sir Henry De la Beche and •*•-*• Professor Phillips, examined a large tract of country last year, including Herefordshire and Gloucestershire, where both the Old and New Red Sandstone systems are so well developed, I observed that that peculiarity in colour which has obtained for the New Red Sandstone group the name of Variegated or Poikilitic, was not due to any peculiarity of colour in the nature of the sand or marl deposited, nor to any peculiarity in the mode of deposition, but that it was due simply and solely to a cause coming into action since the de- position of the strata ; and in point of fact this variegated ap- pearance is produced by causes which have discharged the colour from groups of strata which were originally of a nearly uniform tint. I shall proceed to illustrate this view of the subject by sketches. At Garden Cliff, near Westbury-on- Severn, where a beau- tiful section of the lower beds of the lias and the upper beds of the New Red series presents itself, I observed that the pe- culiar bluish-green colour (which at a distance gives the cliff' the appearance of being composed of alternate strata of red sandstone or marl, and strata of this colour) was not in reality confined to the strata, but, on the contrary, that it extended two or three inches on either side of the dividing planes of the strata ; and again, that the same colour appeared at about the * Communicated by Sir Henry T. De la Beche, F.R.S., F.G.S., Con- ductor of the Ordnance Geological Survey. Phil. Mag. S. 3. Vol. 23. No. 149. July 1843. B 2 Capt. James on the Variegated Sandstone Systems. same distance on either side the great cross lines, a, b (Plate I. fig. 1), whether a fault was produced or not, and this not only in the vertical section, but also along the strata as looking down upon them, at the foot of the cliff, at b, c*. The same appearance, or rather the same fact, may be seen in the Old Red Sandstone in the cliff lower down the Severn near Purton passage ; and it is almost impossible to look at this and not to see that the fissures, whether it be those between the strata, or those which intersect the strata vertically, have acted as chan- nels through which something has been introduced to dis- charge the colour on either side ; but if we arrive at this con- clusion by looking at the matter on a large scale, the exami- nation of the separate slabs brings the fact home to us even more strikingly, for example, in fig. 2. Looking down upon a slab of Old Red Sandstone, which I sketched in company with Professor Phillips, we see cracks extending across it and branching, and this bluish-green colour extending at a nearly equal distance on either side, following every turn and branch, whilst there is no crack or alteration in the structure of the rock at the boundary of the colour. Again, in fig. 3, in marl (and this is a sketch the size of the original), we see the same central crack along the bluish-green colour ; and even this may be sometimes observed in the circular spots (fig. 4), they being the sections of pipes such as one of those in fig. 2. One might multiply such examples to any extent, but enough have been given to establish the fact, that the original red colour has been discharged or altered ; and this has taken place fully to the same extent in the fine sandstones and marl of the Old Red, as it has in those of the new, though perhaps the colours are not so vivid. May 15, 1843. Henry James, Capt. R. E. Since writing the above, I learn from Mr. Mallet, whose scientific acquirements are so well known, that the colouring matter of these light greenish beds in the New Red Sandstone is the protoxide of iron ; and he says, " If [through] a fissure in a rock containing peroxide of iron a stream of water should pass containing an earthy sulphate and organic matter, the sulphate will be decomposed, and sulphuretted hydrogen evolved, which might reduce the peroxide of iron to a lower oxide." This seems to offer the most satisfactory explanation of the chemical action which has taken place, Earthy sulphates * In cases where the strata are not equal to twice the distance at which the colour is discharged, the whole stratum will of course appear of the light colour, as at c. FhU.Mcu/.S.Z.VolM&WI L a hoid 2/£ h/fJJ Fig.8. Fig-h Natural Si^r. Capto J asm*; deli, Jfias/s"? htii Variegated Appwraticas of ttie Yew and Old Red Sandstone. Dr. Kane on the Colouring Matters of Persian Berries. 3 abound in the New Red Sandstone series itself, as well as in the lias and other rocks above j and water from the surface of the earth passing through the strata must be constantly trans- porting organic matter from the surface, small in quantity perhaps in a limited time, but large enough for the ob- served effect when supposed to be in constant action for thousands of years; and this applies with equal force to the Old as to the New Red series, in which, as I have said before, the same effect may be observed. May 23, 1843. H. James. II. On the Colouring Matters of the Persian Berries. By Robert Kane, M.D., M.R.I. A* T^HESE berries, the fruit of the dyer's buckthorn, Rhamnus -■- Tinctoria, are imported from the Levant and from the south of France, for the use of dyers, to whom they furnish a yellow colour of great brilliancy, though not so permanent as some others. The appearance of the berries, as found in commerce, varies considerably; some samples, and those the most valuable, being larger, fuller, and of a light greenish- olive colour, whilst others are smaller, as if shrivelled, and dark brown in tint. The former I consider to have the ap- pearance of being gathered before complete ripening, whilst the latter owe their altered character to being allowed to re- main longer on the stem, or to having been incautiously dried. The colouring matter in these two kinds is essentially dif- ferent. The unripe berries yield but little colour to pure water, and when digested in aether give abundance of a rich golden yellow substance, to which I give the name of chryso- rhamnine. The dark -coloured berries contain little of the sub- stance soluble in aether, but give out to boiling water an olive- yellow material, to which, in its pure form, I give the name of xanthorhamnine. This substance is produced, however, only by the decomposition of the former : thus, if the unripe berries be boiled for a few minutes in water, they, when dried, yield to aether scarcely traces of chrysorhamnine^ this principle being, by contact of air and hot water, changed into xantho- 7'hamnine. Omitting the details of methods of purification and of ana- lysis, the properties and composition of these bodies may be expressed as follows : — * Read before the Royal Irish Academy, Feb. 28, 1842, and now com- municated by the Author. B2 4 Dr. Kane on the Colouring Matters Chrysorhamnine is of a rich golden yellow colour, of a cry- stalline aspect, and may be obtained in brilliant stellated tufts of short silky needles. It is but very sparingly soluble in cold water, and when boiled with water the portion which dissolves does not separate on cooling, but is found to be changed into xanthorhamnine. It dissolves in alcohol, but is not obtained by its evaporation, without being much altered. In aether, how- ever, it dissolves abundantly, and by the spontaneous evapo- ration of its solution is deposited in a pure form. It has no acid reaction, but dissolves in alkaline solutions, in which, however, it appears also to be mostly altered. Dried at 212° Fahrenheit it consisted of i. ii. Carbon 58*23 57*81 Hydrogen 4*77 4*64 Oxygen 37*00 37*55 100*00 100*00 These numbers give the formula C23 Hn On, by which there should be C^ = 138 58*23 Hn = 11 4*64 On = 88 37*13 237 100*00 On adding an alcoholic solution of chrysorhamnine to a so- lution of acetate of lead, a rich yellow precipitate is formed, which, when dried at 212°, was found to be expressed by the formula C23 Hn On + 2PbO, the numbers being as follow: — Theory. Experiment. Carbon 138*0 29*98 . . . 29*62 Hydrogen ... 11*0 2*39 ... 2*19 Oxygen «... 88*0 19*11 . . . 19*59 Oxide of lead . . 223*4 48*52 . . . 48*60 460*4 100*00 100*00 A little water appears to have been lost in the analysis, which, however, does not affect the formula deduced. By the decomposition of a more basic acetate of lead, a yellow precipitate is obtained, which consisted of one equiva- lent of chrysorhamnine united to three equivalents of oxide of lead. The chrysorhamnine may be easily observed in its natural state of deposition in the berry ; it lines the interior of the capsule-cells with a brilliant resinous-looking pale yellow and semitransparent coating. Xanthorhamnine is formed by boiling chrysorhamnine in of the Persian Berries. 5 water, in a capsule, so as to admit of free access of air. It dissolves with an olive-yellow colour, and on evaporating to dryness, remains as a dark, extractive-looking mass, quite in- soluble in aether, but abundantly soluble in alcohol and water. It may be procured also from the berries, without previous separation of the chrysorhamnine, by similar treatment, but it is then rendered impure by a gummy substance being mixed with it. It is very difficult to determine when this sub- stance can be considered anhydrous. Prepared by evapora- tion over sulphuric acid in vacuo, it is quite dry, and may be powdered, but if heated it liquefies below 212°, and continues giving out watery vapour until the temperature is raised to 350°, beyond which the organic matter itself cannot be heated without decomposition. On cooling it reassumes its perfectly dry aspect, and may be easily powdered. It was hence analysed in all these stages of desiccation, with the following results. It contained — Dried in vacuo. Carbon 34-74 Hydrogen 6*93 Oxygen 58-33 100-00 Dried at 212°. Carbon .. 49-97 51*20 Hydrogen . 5'18 5-28 Oxygen . . 44-85 43-52 100-00 100-00 Dried in an oil-bath at 320°. Carbon 52-55 Hydrogen ...... 5-15 Oxygen 42-30 100-00 By adding a solution of xanthorhamnine to solutions of acetate of lead, two combinations may be formed, one by neutral acetate of lead, the other by using the tribasic salt. But it is difficult to obtain either unmixed with some traces of the other, and thence the analysis of both vary a little from the true atomic constitution. Thus the tribasic salt gives — Dried at 212°. Formula deduced. Carbon. . . . 26*58 Hydrogen . . 2*86 Oxygen . . . 25-97 Oxide of lead 45-36 44-59 100-00 Formula deduced. ^23 = 138 34*78 Hw = 27 6-80 o29 = 232 58-42 397 100-00 Formula deduced. ^23 = 138 50-92 H18 ss 13 4-80 0,6 = 120 44-28 271 100-00 Formula deduced. C23 = 138 52-67 H12 = 12 4-58 o14 = 112 42-75 262 ] 00-00 C23 = 138-0 26-93 H15 m 15-0 2-93 017 = 136-0 26-54 2.PbO = 223-4 43-60 6 Professor Young's Demonstration The tribasic salt gives — Dried at 212°. Carbon . . . 21*89 Hydrogen . . 3*06 Oxygen . . . 23*75 Oxide of lead 52*30 100*00 100*00 Formula deduced. 22*07 Cgg = 138*0 21*20 2*82 H! = 18*0 2*76 23*73 O20 = 160*0 24*57 51*38 3.PbO = 335*1 51*47 651*1 100*00 If we consider the xanthorhamnine, as dried in the oil-bath, to be then anhydrous, the bodies analysed become Xanthorhamnine, dry = C23 H12 0]4. dried at 212° m C^ H12 014 + Aq. dried in vacuo = C^ H12 014 + 1 5 Aq. 1 st lead salt, C23 H12 014 + 2. PbO + 3 Aq. 2nd lead salt, C^ H12014 + 3.PbO + 6 Aq. The xanthorhamnine is thus formed by the addition of one equivalent of water and two of oxygen to the chrysorhamnine, as C23 Hn On + HO + 02 = Cc^ H12 014. And if we were" to consider the substance dried in the oil-bath at 320° still to retain an atom of water, it should be simply oxidated chry- sorhamnine, being, when dry, III. Demonstration of the Rule of Fourier. By J. R. Young, Esq., Professor qf Mathematics in Belfast College*. T^VERY thing relating, to the analysis and solution of nu- -•" merical equations has at length been brought under the dominion of common algebra, with the single exception of the rule which Fourier has proposed for discovering the character of a pair of roots indicated in a given interval. The investi- gation of this rule has hitherto involved the analytical theory of curves, or else the theorem of Lagrange on the limits of Taylor's series. It is desirable that this rule be stripped of its transcendental form, and be reduced to a level with the other general principles that now constitute the doctrine of numerical equations. It is the intention of the following proof to effect this object. Let a, b represent the numbers which bound the doubtful interval comprehending the two roots sought. We may con- sider these numbers to be positive, giving rise to the following variations in the three final functions : — * Communicated by the Author. of the Rule of Fourier. 7 (a.) + - + {b.) + + + Let a -f h be one of the intervening roots ofy (x) = 0 — the least — and b — k the other : we shall assume h and k to be real. From common algebraical principles we have /« [a + h) =/2 (a) +f, (a) h +/4 (a) £ +/5 (a) Jl yJn-2 + /w(a) 1.2.3... n-2; and the right-hand member of this is the second limiting po- lynomial derived from these limiting polynomials being ■A to * +/a W 1 +/4 (iJofK' /• ^2.3...;-l [2'] A2 Aw-2 /»(«)+/8^)^+/4(«)^+— /»(«)2,3.„w,2 • M The positive roots of the equations [1.] = 0, [2.] = 0, [3.] = 0, when written in ascending order, are known to arrange themselves as follows : — 0 0 ax a2 0 bx bA-= A + & + a negative quantity /i («) § /i (6) ; 1 J therefore, regarding only absolute numerical values, /,(«)+77M* + But 6 — a is necessarily not less than 7z + Jc: consequently the condition which must be fulfilled whenever, as assumed above, the doubtful roots are real : and this is the criterion of Fourier. Belfast, May 13, 1843. IV. On the Problem of Three Bodies. By the Rev. Brice Bronwin*. LET M, m, and ml be three bodies acting upon each other with forces as the reciprocal square of the distance ; let x, y, and z be the coordinates of m, x1, y\ and z' those of m\ both referred to M as their origin ; also let .2" = x' — x, y" =y — y, 2" = j? — z be those of ml parallel to the former, having m for their origin ; and let r= vV+j/2 + z2,V''= W2+*/'2 + 3,2,y = ^*"2+y'2 + ^ To abridge we shall make M + m = fx,, M + ml — /J, m + mi mfif1iH+m+mf=lS, lhemfQ = — — + — J ^ '- — jj, the differential equations of the motion of m about M are r d^ dQ_ ^y dQ_ d*z dQ_ dt* + dx ~ U' dt*+ 1$ "' dt* + 1z~-U' • Communicated by the Author. Problem of Three Bodies. 9 Making x, y, z, and m change places with #', y'f z' and ml ; d2x' dQ + = 0, "v+4^ = o, **■+*£*• -z'd2x ~ x" d2z" -z" d2x"' x d2y -yd2x _ a/ d2y> -y'd2x' _ x" d2y" -y" d2 x" y d2z - z d2y ~ y d2 z' - z' d2y' ~ y" d2 z" — z" d2y"' From these two, dividing the one by the other, we obtain a third set. From the same source also we find (x1 z — z1 x) (x d2y —yd2x) = (x1 y — xy') (xd2z — zd2 x), (x'z-z' x) (V d2y' -y' d2 x1) = {a? y -y1 w) (x1 d^z1 - z' d2 x% (x'z - zlx) (x"d*y"-y"d*x") = (x'y -y'x) {x"d*z"-z"d*x"), (y'z — z'y) (x cPy —y d* x) = {rfy—y1 x) (yd2 z — z d2y), and several others. (D.) 10 The Rev. Brice Bronwin on the With equal ease we find from (B.), integrating results, ,, xdy—ydx ,, .x'dy'—y'dx' ,x"dy"—y"dx" Mm — 2__Z — -j- Mm' — Z—rf (- mm' ^— jf = c, dt dt dt M m xdz—zdx ~dt + Mm' x'dz'—z'dx' ~di -f mm ,x"dz"-z"dx" — J dt HI _. ydz—zdy , A, .y'dz'—z'dy' .y"dz"—z"dy" ., M;»- — 3- — - + Mffl'^ tt — — + mm'Z — ^- = c". dt dt dt These last are known. ,, , mx + m'x' my + m'y' mz+m'z' Make ■ 7- = «, — — • — r- = v, ■ — j- m to ; m + m m + m' m + m! u, v, and ydz-zdy _ x'dy' -y'dx' , IT — ~C3' — ~dt~ -ci'&c" x"dy" -y"dx" _ „ dt = c"v &c. The following are identical : — h * — c* y + ci * = °> ^s d - ^y + ^i *' = °» c"3.r" - c\y" + c"x *" = 0, .*• de3 - y dc% + * c^ =0' ^ (G.) a?d(?a-y'd" NMm'(c'3^-c'^+ dA z)z=/J(d'x—dy + cz) —m' {d'x1 — dy' + cz')> NMm{c3x"—Ccly" + c1z")=fjt,(d'x'—dy' + cz')—m(d,x—c'y + cz)9 Nmm'(c"3.r— c"2y +d'1z)=m' (d'x1 —dy' +cz') +m(c" x—dy+cz), and two others. The second members, where c", d, and c are constant, manifest how these equations are formed. We might derive from (B.) many other curious results, but we shall only notice the following : — c Mm^ + Mm'^+mm'^j± = 0, ^ + Mm'^+mm'^ = 0, M m —^ + Mm' —~ + mm' —^ = 0. M»» (K.) However convenient the perturbating function of Lagrange may be for the purposes to which it is applied, it is not adapted to the finding of integral equations of the first order. Make R = Mm Mm' mm' + + may be put under the following form : — d?x dR dR and the equations (A.) Mm dt* d* = ^+m^" Mmd¥ d2y dR dR dy dy' dR Mm-— = //,—=— dt* dR alu+mlu''> Mm = fi' M m' — A — u! " + rn'^< M m df- dR ''"'dy' dR dy9 ,d*x' _ ,dR dt2 ' ,d*z' dt2 + ml dR dx3 d x ,dR ,dR fi' -7-j + m' -j— . az' dz Wl. These may be put under the following form : — Mm d*x + mm d?x -d*x' _ „dR dt* = dx* ,, .d^x1 .d^x-d^x1 M m -r-o — mm' dt* dt* „dR 12 The Rev. Brice Bronwin on the Tvr d*P , ,d*y-d*y' „dll M m^T% + m m ,,2 — — = N -7—, dt2 at2 dy Tvr ,d*y' ,d*y-d*y' XTdR Mm -jw — mm' — V—r-s — y- = N-r-7, dt2 dt2 dy ,, d*z ,d*z-d*z' „dll M m To. + mm' -j-z = N -^— , dt2 dt2 dz ,, ,d*z' ,d*z-d*z' XTtfR M m tj — mm' -j-s = N -r-.. dr dt2 dz1 Whence we easily obtain ,, dx2 + dy* + dz* ,T . da!* + dy12 + dz12 Mm rf? +Mm tfc ,dx"* + dym+ dz"2 „XTO . + m ml * 2NR = i, dt2 the result being integrated, and x" put for #' — x, &c. If we eliminate dx, dy, dz, dal, &c. by their values in 11, v, and w; 11', t/, «/, as in (F.), we shall have M/i„^±^±*f+ iw «w±f«!_2NR=i.(M.) Thus the square of the velocity of the centre of gravity of m and m! about M, multiplied by M {m + m'), added to the square of the velocity of m! about m, multiplied by m m! -t — , is equal to 2 N R plus a constant. Two other similar formulas may be found relative to the centres of gravity of M and m, and of M and m! By the nature of the function R, we have dR dR ,dR ,dR x -j— — y -5 1- x' -r—. — y' -=— 1 = 0, dy y dx dy1 * dx1 ' dR dR ,dR ,c?R_ dz dx dz' dx1 -'■ ' dR dR ,dR ,dR '* * dz dy u dz' dy' By the aid of these properties we may easily derive from (L.), or the equations following them, the equations (E.) relative to the areas described. We find from (A.), ,, xd*x + yd2y + zd?z , ,, ,x' d% x' + y' d2y' + z' d*z' M m y,,g + M ml ,,a dt2 dt2 Problem of Three Bodies. 1 3 ,x"d*x" + y"d*y"+z"d?z" , XTT3 rt- H .. + 7ww' ,^ hNR = 0. If we combine at1 this with the equation immediately preceding (M.), we have 4- mm' ai~ r~- • • (N.) „XT/Mm Mm' wm'\ „. If § be the distance of the centre of gravity of m and m' from M, we have mr2 + m' in sa ft," g2 H y- r"2. By this elimi- nating d2 (r2) from (N.), there results „ d2 (g2) Nmw' its properties are dP dP c?v d# rfr ^ «?*/' = o, <*P f*P ^/^P_ ;rfP e?# rf<2? c?^ da' 0, dP dP , ,tfP ,rfP v dz dy " dz' dy' Equations (A.) will be replaced by d2x imx _ ,dP d*V , py _ ,dP d2% fiz _ ,dP Jp + 73 - m jp -Jp + -7a - m jjn JJ2+ 73 ~ m -J3 ; dV tl^__ dP d^_ M dP d?J f£* _ d_P dt2 + P5 ~m dx> dt2 + r'3 ~m dy9 dt2 + r'3 ~~m dz' From these, by the aid of the foregoing properties of P, we without difficulty find x dd3 — y d d2 + z d dx = 0, x1 d c3 — y1 d c2 + z' d cx = 0. These we have before found in a different manner. They are only introduced here to give an example of the use of differ- ent perturbating functions. On some occasions perhaps the following form may be used 1 ™i m with advantage : V = — T ITT'" d2 x fix __ d V dx» d^y A6 y _ d V d2 z fJbz _ dV 14 Professor Johnston on the Sugar of the Eucalyptus. But V will not serve for the equations of the disturbing body. If we wish to find integral equations of the first order, we should have a perturbating function which will serve for two at least of the three sets of equations (A.). My paper on M. Jacobi's Theory of Elliptic Functions, printed in the Number of this Journal for the present month, is not very intelligible. I wish, therefore, to subjoin a few words in the hope of making it plainer. The expressions sin amtico, cos am n oo, mean sine of amplitude of n w, cosine of amplitude of n ca. So also s au, c au mean sine and cosine of the amplitude of u. They should have been printed thus : — sin am n ca, cos am n co, s au, c au. These faults run through the paper. Moreover the a m and a for amplitude should not have been in italics, as italics appear to denote quantity only. Denby, near Huddersfield, April 11, 1843. V. On the Sugar of the Eucalyptus. By James F. W. Johnston, Esq., M.A., F.R.S.* TN Van Diemen's Land a species of sugar or manna falls in drops or rounded opaque tears from several species of Eucalyptus. This is collected in considerable quantity, but it is doubtful still I believe whether it is a natural exudation of the trees from which it falls, or, like the different kinds of honey-dew in our own country, is the consequence of punc- tures made by insects. I am indebted for a portion of this manna to Sir W. Jackson Hooker, to whom also I owe the above information regarding its origin. It is soft, slightly yellowish, opaque, is inferior in sweetness to cane-sugar or to ordinary manna, and is in small, rounded, slightly cohering masses. iEther extracts from it only a minute portion of wax, alcohol leaves behind only a small quantity of gum, while water dissolves it without sensible residue. The aqueous solution crystallizes on evaporation in minute radiating prisms and prismatic needles which form rounded masses having a crystalline structure. It is obtained however from water in distinct crystals with much greater difficulty than from its solution in ordinary alcohol. In boiling alcohol it dissolves in considerable quantity, and is in a great measure precipitated in beautiful white but minute prismatic crystals as the solution cools. It not unfrequently deposits itself also in the form of a white hard and solid crust on the bottom and sides of the bottle into which the hot solution is filtered. This sugar as it crystallizes from the alcoholic solution has * Communicated by the Chemical Society; having been read De- cember 20, 1842. Professor Johnston on the Sugar of the Eucalyptus. 15 the same constitution as grape-sugar, C12 H14 014, or C24 H28 028, but it differs from grape-sugar in its appearance, in its relations to alcohol as above described, in the ease with which it can be obtained in a pure crystallized form, and in its relations to heat. When suddenly heated at once to 200° or 212°, it melts and loses 5 atoms of water, whereas grape-sugar loses only four. But if it be first gradually heated and kept for two or three hours at 180° only, it will part with seven atoms of water without melting. In that respect it resembles a salt, which if heated suddenly will melt in its water of crystalliza- tion, but by a cautious regulation of the heat may be dried without undergoing fusion. If once melted, this sugar may be kept for several hours at 212° without losing much more than the five atoms, and it must be raised to 240° or 250° before it parts with the whole seven, and in every case in which I have made the experiment has even assumed a brown colour, owing to incipient decomposition before the seven atoms have been altogether removed. When die seven atoms have been driven off by a heat not higher than 200°, the dry powder may be heated to 280°, when it begins to fuse, and may be kept for several hours at 300° without further loss or any change of colour. After being thus heated the sugar attracts moisture rapidly from the air, and if left over night in a damp room it will assume the form of transparent globules of syrup, which gra- dually crystallize into colourless radiated masses having the original weight of the portion of sugar experimented upon. We may conclude therefore that the seven atoms are alto- gether water of crystallization. When mixed with oxide of lead moistened with water and then gradually dried and heated to 300°, it appeared to lose two additional atoms of water without undergoing decom- position ; but when exposed to the air on cooling, the mix- ture rapidly attracts water again from the air. When this mixture after thus heating is boiled with distilled water and thrown upon the filter, a solution of sugar passes through in which hydrosulphurets detect no trace of lead. The following formulae exhibit the constitution of this sugar and the loss of weight it undergoes at different temperatures : — Loss by experi- Crystallized sugar before! n „ 0 merit, per cent. or after heating . . .J U*4 "21 ^21 + 7 HU Fused at 212° to 220° . C24 H21 021 + 2 HO 11-23 Dried without fusion be-~l r H n tween 180° and 300° J ^24 "21 Uai 15'88 16 Mr. Cock on Palladium. Loss by experi- ment, per cent. D™?„ ir„; .ra/.00:}^ h„ ^ o„ ? ^ ? Tthe rbecaer.Sed *}<>» H» P*s O,, + 7 HO? This sugar, in its relations to alcohol, in the ease and rea- diness with which it crystallizes from an alcoholic solution, and in the appearance of its crystals, has much resemblance to manna-sugar (Mannite). It is more soluble however in boiling alcohol than mannite, and is therefore obtained in larger quantity on the cooling of the alcohol in which it has been dissolved by the aid of heat. Mannite also, if heated gradually, may be raised to 300° (I do not know how much igher) without either melting or undergoing any loss of weight. Eucalyptus-sugar gives a precipitate of a slightly brownish tinge with caustic baryta ; and a white precipitate is also ob- tained by mixing it with a solution of ammoniacal trisacetate of lead. This salt of lead I am at present preparing for ana- lysis, and I hope to have the honour of submitting the results to the Society at a future meeting. In the mean time the formulas presented in this notice must be considered as open to correction. VI. On Palladium — Its Extraction, Alloys, Sec. By William John Cock, Esq.* THIS metal was discovered by Dr. Wollaston in the year 1803f, as one of the alloys of native platinum, which for some time after this discovery appears to have been consi- dered the only source of palladium ; and as the quantity of the latter metal so alloying the native platinum is very small, it was then considered as a very rare metal : of late years, however, the importation into this country from Brazil of gold dust, alloyed with palladium, has occasioned a much more extensive supply of this metal, as it exists in some specimens of gold dust to the extent of 5 or 6 per cent., and in one instance (that of the gold from the Candonga mine) it constitutes the only alloy of the gold. The operation of refining is conducted in the following manner: — The gold dust is fused in charges of about 7 lbs. * Communicated by the Chemical Society ; having been read January 3, 1843. t Dr. Wollaston's original paper on Palladium, reprinted from the Philosophical Transactions, will be found in Phil. Mag. S. 1. vol. xx. p. 163; see also vol. xv. p. 287.— Edit, Mr. Cock on Palladium. 17 troy, with its own weight of silver and a certain quantity of nitrate of potash ; the effect of this fusion is to remove all earthy matter, and the greater part of the base metals con- tained in the gold dust and in the silver melted with it. The fused mixture is cast into ingot moulds, and when cooled, the flux or scoria (containing the oxides of the base metals and the earthy matter, combined with the potash of the nitre) is detached. Two of the bars thus obtained are then remelted in a plumbago crucible, with such an addition of silver as will afford an alloy containing one-fourth its weight of pure gold, and which being first well-stirred to insure a complete mix- ture, is poured through a perforated iron ladle into cold water, and thus very finely granulated ; it is then ready for the pro- cess of parting. For this purpose about 25 lbs. of the granu- lated alloy is placed in a porcelain jar, upon a heated sand-bath, and subjected to the action of about 25 lbs. of pure nitric acid, diluted with its own bulk of water: after the action of this quan- tity of acid, the parting of the gold is very nearly effected ; but to remove the last portions of silver, &c, about 9 or 10 lbs. of strong nitric acid is boiled upon the gold for two hours. It is then completely refined, and after being washed with hot water is dried and melted into bars containing 15 lbs. each. The nitrous acid gas, and the vapour of nitric acid arising during the above process, are conducted by glass pipes (con- nected with the covers of the jars) into a long stone-ware pipe, one end of which slopes downwards into a receiver for the condensed acid, the other end being inserted into the flue for the purpose of carrying off the uncondensed gas. The nitrate of silver and palladium obtained as above is carefully decanted into large pans, containing a sufficient quantity of solution of common salt to effect the precipitation (as a chloride) of the whole of the silver, the palladium and copper remaining in solution in the mother liquor, which is drawn offj and when clear is run off, together with the sub- sequent washings from the chloride of silver, into wooden vessels, and the metallic contents are then separated in the form of a black powder, by precipitation with sheet zinc, as- sisted by sulphuric acid. The chloride of silver, when washed clean, is reduced by the addition of granulated zinc Washed on the filter with boiling water, dried and melted in plumbago crucibles, with- out the addition of any flux. From the black powder obtained as above, the palladium is extracted by resolution in nitric acid and super-saturation with ammonia, by which the oxides of palladium and copper Phil. Mag. S. 3. Vol. 23. No. 149. July 1843. C 18 Mr. Cock on Palladium. are first precipitated and then redissolved, while those of iron, lead, &c, remain insoluble. To the clear ammoniacal solu- tion, muriatic acid is then added in excess, which occasions a copious precipitation of the yellow ammonio-chloride of pal- ladium, from which, after sufficiently washing it with cold water and ignition, pure metallic palladium is obtained. The mother liquor and washings contain all the copper and some palladium, which are recovered by precipitation with iron. Pure palladium is of a greyish-white colour, rather darker than that of platinum ; it is both malleable and ductile, though inferior in those qualities to pure platinum ; its specific gra- vity is 11*3, which may be raised by hammering or rolling to 11*8. When perfectly pure it cannot be fused even in small quantities in an ordinary blast furnace, but may be brought into such a state of agglutination as to bear laminating or drawing into wire. It may be completely fused by means of oxygen gas, and being kept some time fused, is said to burn with the production of brilliant sparks ; it is not tarnished by exposure to sulphu- retted hydrogen, nor oxidated by the air at the ordinary tem- perature, or at a bright red heat ; but it has the singular property of becoming oxidated by exposure to air at a dull red heat, the surface becoming coloured in the same manner as iron or steel ; and by continuing the process cautiously for some time, the metal becomes coated with a brittle crust of oxide of a brown colour; this oxide is, however, reduced by a temperature very little higher than that necessary for its formation ; and the surface of the metal regains its original colour upon being heated to a bright red, and cooled out of contact with the air. It is with difficulty soluble in nitric acid when pure and fused, or in a state of aggregation, but is readily so when al- loyed to some extent with silver or copper, and still more so when in the form of the black powder above referred to, in which state it is also soluble with the aid of heat in sulphuric and muriatic acids; but its proper solvent is nitro-muriatic acid, which, if it be not very much alloyed with silver, dis- solves it readily. It is of all the metals that which has the greatest affinity for cyanogen ; and by means of cyanide of mercury, it may be separated from all its solutions. It may be alloyed so as to be malleable with gold, silver and copper, several of its alloys with the two latter metals being of great use in the arts from their hardness and elasti- city, and non-liability to rust or tarnish. When added to gold or copper, it whitens both those metals in a very great Prof. Liebig on the Formation of Fat in the Animal Body. 19 degree, about 20 per cent, being sufficient in either case to destroy the colour of those metals. The uses to which the alloys of palladium have been ap- plied, are for the points of pencil-cases, for lancets for vacci- nation, for the graduated scales of instruments, as a substitute for gold in dental surgery, or for any purpose where strength and elasticity, or the property of not tarnishing, is required. VII. On the Formation of Fat in the Animal Body. By Justus Liebig, Ph.D., M.D., F.R.S., $c* T N my published work on ' Organic Chemistry, in its ap- ■■■ plication to Physiology and Pathology,' I have endea- voured to explain the nutrition of the human and animal organism, according to the present state of organic chemistry. I have pointed out the relation between the nitrogenous food and the nitrogenous constituents of animal bodies, and have considered the non-nitrogenous constituents of the food as the means of the formation of the non-nitrogenous constituents of animals. The circumstance, that the large class of carnivorous ani- mals do not take any sugar, starch, or gum in their food, leads of itself to the opinion that these substances are not required for proper nourishment, namely, for the formation of blood; and as it appears from the analysis of plants containing nitro- gen, that they possess a similar composition to the substances of the blood, it follows also that in the bodies of herbivorous and graminivorous animals, the carbon of the sugar, gum and starch cannot be applied to the formation of the blood. The nitrogen of the nitrogenous ingredients of the food is therefore in a state of combination, in which the elements necessary for the production of the albumen are already present both in number and relative proportions ; in the food of the gra- minivorous animals, we know after all of no other compound, which can supply nitrogen to starch, sugar, or gum, for the production of albumen. As sugar, gum and starch, in their normal state, disappear in the vital processes of graminivorous animals, and as they are given out of their bodies as carbonic acid and water, it follows from such a conversion that they serve by means of the respiration for the production of animal heat. The disappearance of fat in animals in consequence of * Translated from the German original by Mr. E. F. Tesehemacher, and communicated by the Chemical Society; having been read January 3, 1843. On the subject of this paper see a translation of M. Dumas' s memoir On the Chemical Statics of Organized Beings, in Phil. Mag. S. 3. vol. xix. C2 20 Professor Liebig on the disease, or of an increased absorption of oxygen, and its being given out in the form of carbonic acid and water, is a proof that that non-nitrogenous body is converted to the same use as sugar, gum, or starch in animal bodies, and for want of other non-nitrogenous food is applied to the respiration. The further consideration, that the flesh of the carnivo- rous, which of all animals eat most fat, contains no fat, and is not eatable ; that the fat in the bodies of graminivorous animals increases when the process of respiration, and with it the absorption of oxygen diminishes, through a want of exercise or an increase of temperature, leads to the conclusion that the fat has its origin in the non-nitrogenous food, the carbon re- maining in the body in the form of fat when there is a defi- ciency of the necessary quantity of oxygen to convert it into carbonic acid. Supported by the example of what certainly takes place in the processes of fermentation and putrefaction, in which sugar and starch, by giving out oxygen or carbonic acid, form new combinations, which, like aether and fusel oil, more resemble fat in their properties than any other known compounds, I have endeavoured to trace out the formation of fat, on the supposition that the carbon of non-azotized substances re- mains in the animal body in the form of fat. According to my statement, the fat consequently originates from the non-nitrogenous constituents of the food : let us suppose from sugar, then this must have undergone a che- mical change in conformity with my proposition. The formation of wax from honey which contains none, in the body of the bee, of which, from the experiments of M. Grundlach of Cassel, there can be no doubt, appears to remove every objection to the possibility of such an action taking place. I never had the least idea of defending in my book the opi- nion, or even of expressing it, that the fat which was taken in the food of animals did not contribute to increase the quantity of fat in their bodies; but I was not aware of any supply of butter in the grass which is daily consumed by cows, or of tallow, of lard, or goose-fat in potatoes, barley and oats ; in the analyses of these substances as at present given, they con- tain only waxy substances, and that in such a small quantity that I consider the formation of fat could not be attributed to it. These ideas concerning the origin of fat in animal bodies took a new dix-ection from a note which M. Dumas appended in the Annates de Chimie (new Series, vol. iv. p. 208) to my treatise on the nitrogenous food of the vegetable kingdom ; Formation of Fat in the Animal Body. 21 in this note M. Dumas says, — " M. Liebig is of opinion that graminivorous animals produce fat out of sugar and starch, while MM. Dumas and Boussingault consider it as a fixed rule, that animals, of whatever kind, produce neither fat nor any other alimentary substance ; that they receive from the ve- getable kingdom all their aliments, whether it be sugar, starch, or fat. " Were the proposition of M. Liebig founded upon fact, the general formula of chemical equivalents of both kingdoms, as defined by MM. Dumas and Boussingault, would be false. But the commission on gelatine has dispelled all doubt, that the animals which eat fat are the only ones in which fat is found to accumulate in the tissues." The origin of fatty compounds in animal bodies has, through this note, become a question of dispute. As far as regards myself, I have neither time nor inclina- tion to engage in it ; the object of my observations was to leave no doubt of the physiological importance of the fat of animal bodies, as regards the process of respiration. In this view MM. Dumas and Boussingault agree with me. I think it now right to explain the reasons which induced me to consider that little or no increase of fat in animal bodies was to be ascribed to the ingredients of the food containing fat, consumed by graminivorous animals. The food which, according to the experience of physicians, has a decided influence on the formation of fat in animal bodies, is that which is richest in starch, sugar, and other substances of a similar constitution. Rice, Indian corn, beans, peas, linseed, potatoes, beet are used in husbandry in large quantity with great effect for fat- tening, that is, for the increase of flesh and fat. In Bavaria beer is used as a stimulating food for the increase of fat. Whether much or little importance may be ascribed to the universal experience of husbandry, it is certain that animals which are fed upon these different substances, under certain conditions (abundance of food, little exercise, high tempera- ture, &c), after some time become much fatter than before. This fat proceeds from the food. Rice, beans and peas have been carefully analysed by various chemists. Braconnot found in Carolina rice 0*13 per cent, of oil, in Piedmont rice 0*25 per cent.; Vogel found in rice 1*05 per cent. According to these analyses, the organism received from 1000 lbs. of Carolina rice 1*3 lb. or 2*5 lbs., or according to Vogel lO^lbs. of fat. Peas contain, according to Braconnot, 1*20 of a substance soluble in aether, which he calls leafgreen (chlorophyll). The 22 Professor Liebig on the bean of the Phaseolus vulgaris, according to the same chemist, contains 0'70of fat soluble in aether. Fresenius obtained from peas 2*1 per cent, of a substance soluble in aether, from linseed 1*3 per cent. For every 1000 lbs. of peas or beans the organism receives, according to Braconnot 12 lbs., according to Fresenius 21 lbs. of fat, and from as many beans only 7 lbs. of fat. Beer, as far as I am aware of, contains no fat : Fresenius obtained from the pulp of the beet-root 0*67 per cent, of a substance soluble in aether. According to further direct examinations made in our laboratory, 1000 parts of dried potatoes gave 3*05 parts of a substance soluble in aether. This substance possessed all the properties of resin or wax; we will, however, assume that potatoes contain y^jo" of their weight of fat. Three one-year- old pigs, fattened with 1000 lbs. peas and 6825 lbs. potatoes fresh boiled, which are equal to 1638 lbs. of dried potatoes, increased in weight in thirteen weeks from 80 lbs. to 90 lbs. each. A fully fattened pig averages in weight from 160 lbs. to 170 lbs., and after killing the fat weighs from 50 lbs. to 55 lbs. The three pigs have consumed 21 lbs. of fat, con- tained in the 1000 lbs. peas, and 6 lbs. in the 1638 lbs. of po- tatoes, together therefore 27 lbs. Their bodies, however, con- tained from 150 lbs. to 165 lbs. of fat. There is an increase of from 123 lbs. to 135 lbs. more fat than the food contained. A pig one year old weighs from 75 lbs. to 80 lbs. ; suppose it to contain 18 lbs. of fat, there still remains, leaving entirely out of question the matters soluble in aether contained in the ex- crements, 69 lbs. to 74 lbs. of fat* ; the production of which in the organization cannot be doubted, and whose formation remains to be accounted for. M. Boussingault's examinations concerning the influence of food on the quantity and composition of the milk of the cow, furnish other more important grounds for the opinion that animals produce fat out of certain food, which is neither * M. Vogt, a butcher at Giessen, in answer to some questions of mine, gave me the following as the result of his experience, which has been con- firmed by other intelligent persons: — A restless pig is not adapted for fat- tening, and however great the supply of food it will not grow fat. Pigs which are fit for fattening must be of a quiet nature ; after eating they must sleep, and after sleeping must be ready to eat again. When a pig is a year old it weighs from 75 lbs. to 80 lbs., and if the fat is intended to be used as lard, it must be fed daily for thirteen weeks with 20 lbs. to 25 lbs. of boiled potatoes, and about a measure of peas (2 litr.); towards the end of the time the food may be somewhat diminished. A pig so fattened weighs from lb'OIbs. to 170 lbs., and contains of fat and lard, taken altogether, from 50 lbs. to 55 lbs. A pig of a year old has a lard membrane under which the lard is secreted, but at that age it does not contain lard. Formation of Fat in the Animal Body. 23 fat itself, nor contains fat (Annates de C/iim. et dePhys. t. lxxi. p. 65). M. Boussingault' s experiments correspond with universal experience, and I believe are to be relied upon ; it is, there- fore, the more inconceivable to me that he has placed himself by the side of those who support the opposite opinion. A cow was fed at Bechelbrunn during eleven days upon daily rations of 38 kilogrammes of potatoes, and therefore in eleven days upon 418 kil. Also 3*75 kil. chopped straw; in eleven days, 41*25 kil. In these eleven days she gave 54*61 litres of milk, which contained 2284 gram, butter. As 418 kil. of fresh potatoes are equal to 96*97 kil. of dry potatoes (potatoes contain, according to M. Boussingault, 76*8 water and 23*2 solid matter, Annates de Chim. et de Phys. 1838. p. 408); further, as 1000 gram, potatoes contain only 3*05 gram, of soluble matter, and the straw, according to expe- riments made here, contains only 0*832 per cent, of a substance soluble in aether (a crystalline wax), the cow had, therefore, in eleven days consumed 291 + 343 gram. = 634 gram, of substance, soluble in aether. There was contained in this milk however 2284 gram, of fat. In another case, in a trial carried on in winter, the daily rations of the cow was for a long time 15 kil. of potatoes and 7^ kil. of hay. The quantity of milk amounted in six days to 64*92 litres. These 64*92 litres of milk contained 3116 gram, of butter. In six days the cow consumed 90 kil. of fresh potatoes, equal to 19*88 of dried; in the same time 45 kil. of hay were consumed. Suppose that the 19*88 kil. of potatoes supplied to the cow contained 60 gram, of fat, the other 3056 gram, of butter must have originated from the 45 kil. of hay. According to this, hay must contain nearly 7 per cent, of fat. This is easily ascertained by experiment. From hay of the best quality, in the state in which it is consumed by the cows, 1 '56 per cent, of a substance soluble in aether was obtained in the Giessen laboratory. Taking the hay to contain 1*56 per cent, of butter, the 45 kil. of hay could supply the cow with only 691 gram., there remains, therefore, to discover whence the other 2365 gram, of butter originated which M. Boussingault found in the milk. In a note which M. Dumas has appended to a communi- cation of M. Romanet's (Comptes Rendus de V Acad, des Sciences, 24 Oct.), the following remarks are made: — " Hay contains in the state in which it is consumed by the cow, nearly 2 per cent, of fatty matter. We will show (MM. Dumas and Payen) that the ox which is fattened and the milch cow furnish a smaller quantity of fatty material than 24 Professor Liebig on the the fodder contains. As regards the milch cow in parti- cular, the butter in the milk corresponds very nearly with the quantity of fatty material contained in its food ; at least as far as in that of the food we have yet studied, namely hay and Indian corn, which last the cow does not usually obtain as food." After the foregoing facts, which I could considerably mul- tiply, it will be very difficult for MM. Dumas and Payen to prove that the cow, for instance, furnishes from the fatty matter contained in the food only the corresponding quantity of butter. The proof of the supposition, besides, that animals receive the fat in their food in the same state as it is found in their bodies, is impossible. Nothing is easier to decide than the question whether or not the butter which the cow produces, is contained as butter in the hay. Hay gives after exhaustion by aether a green solution, and on evaporation a green residue, with a strong agreeable smell of hay, which possesses no properties characteristic of fatty substances. This green residue consists of various substances, of which one is of a waxy or resinous nature, known under the name of chlorophyll ; another ingredient of the same crystallises from a concentrated aethereal solution in minute laminae, and is the crystalline wax which Proust obtained from plums and cherries, from the leaves of cabbages, from a spe- cies of Iris, and from grasses, and which is probably identical with the wax that Avequin collected in such large quantities from the leaves of the sugar-cane. M. Dumas has analysed this substance, and found it to differ both in composition and properties from any of the known fats ; in consequence of which he felt justified in giving the name cerosine to this substance. M. Presenilis obtained by means of aether from straw, and M. Jagle, of Strasburg, from the fresh plant, Fumaria offici- nalis (in the Giessen laboratory), by means of alcohol, a cry- stalline wax, very similar to cerosine. The occurrence of wax in the vegetable kingdom is very extensive, generally ac- companied by chlorophyll. Margaric or stearic acid, the principal ingredient of the fat of animals, is neither found in the seeds of corn, nor in herbs nor in roots which serve as food. It is evident that if the ingredients of the food soluble in aether are convertible into fat, margarine and stearine must be formed out of wax or chlorophyll. As far as our experience goes, the chlorophyll of the food taken in a green state is given out from the body unchanged; even in man the excrements retain the colour of the green vegetables consumed. It is also considered that the wax does Formation of Fat in the Animal Body. 25 not experience any change in the organism. All doubt may be removed by the simplest experiments; it may be shown that the excrements of the cow contain as much of the substances soluble in aether as has been consumed in the food. The ex- crements of a cow which was fed upon potatoes and grass were dried and exhausted by aether; a green solution was obtained, somewhat darker in colour than that given by hay, which upon concentration owed its consistency to a white crystalline waxy substance, which was surrounded by a dark green mother liquor. Upon further evaporation it gave out an unpleasant smell, and left when dried at 100° C, 3*119 per cent, of the weight of the excrements of fat and similar substances. As M. Boussingault has found that the dried solid ex- crements {Annal. de C/iim. et de Phys. t. lxxi. p. 322) amount to four-tenths of the weight of the dried fodder, it is evident that these excrements contain very nearly the same quantity of fatty substances as the food consumed. 1\ kilogr. of hay contain (at 1*56 per cent.) 116 gram, of fat. The 15 kilogr. of potatoes contain further 10 gram, of fat. In the whole, therefore, 126 gram, of fat. The solid daily excrements weigh 4000 gram. ; they contain (at 3*119 per cent.) 124*76 gram, of fat. A cow which pro- duces in six days 3116 gram, of butter, consumes in its food during the same period 756 gram, of substances soluble in aether, and gives off in her excrements 747*56 gram, of sub- stances of the same nature and properties ; it must therefore follow, that in the production of 6£ lbs. of butter in the milk, these ingredients of the food can have no share. I consider I have now demonstrated that the fat which accumulates in the bodies of animals during the fattening process, and that the butter daily produced in the milk, do not originate from the wax or chlorophyll of the food, but from the other ingredients of it. I think I should be giving myself unnecessary trouble to look after facts to correct M. Dumas's peculiar opinion, because upon further consi- deration it is of a nature to correct itself. It is similar to the idea of M. Payen, that the oil of po- tato spirit (fusel oil) is ready formed and contained in po- tatoes. But since it has been found that the last syrup arising from the preparation of beet-root sugar produces in the distillation of brandy a considerable quantity of fusel oil, no one will doubt its formation during the process of fer- mentation. The opinion of M. Dumas is a necessary consequence of the exclusive hypothesis, that animals produce in their or- ganism no substances serving as food (note quoted above), 26 Professor Liebig on the but that they receive all sustenance, whether sugar, starch, or fat, from the vegetable kingdom. I agree perfectly in opinion with M. Dumas in relation to the substances which serve for the formation of blood; but differ from him in considering it as fully proved, as far as observation extends, that wax is formed in the body of the bee, and fat in the stall-fed cow. In regard to the principle of M. Dumas, that the organism of an animal is not able to produce any substance serving as food, it is equivalent to saying that the organism produces nothing, but only transforms it ; that no combination takes place in its body, when the materials are not present by means of which the metamorphosis originates. Thus the for- mation of sugar of milk in the bodies of carnivorous animals cannot take place, for dog's milk, according to Simon, con- tains no sugar of milk. Thus also fat cannot be produced in their organism ; because, besides fat, they do not consume any non-nitrogenous food. But starch, gum and sugar con- tain, even with their large quantity of oxygen, all the ingre- dients of fatty bodies; and the formation of butter in the body of the cow, and of wax in that of the bee, leave hardly any doubt that sugar, starch, gum, or pectine, furnish the carbon for the formation of the butter or of the wax. It is further certain that the brain (Fremy), the nerves, the blood (Lecanu), the faeces, and the yellow of the egg (Chev- reul), contain a substance in considerable quantity with a far smaller proportion of oxygen than the known fatty acids, a substance which hitherto has not been found in the food of graminivorous animals. The formation of cholesterine from fat cannot be supposed without a separation of oxygen or of carbonic acid and water; it must be derived from a substance far richer in oxygen in consequence of a process of decomposi- tion or metamorphosis, which, applied to the case of starch or sugar, explains their conversion into fat in the simplest manner. In the before-mentioned note to the observations of M. Ro- manet, M. Dumas attempts, from the facts quoted in the pre- face to my Pathology, to weaken the conclusion to which I had arrived concerning the formation of fat in the animal body. These facts concern the quantity of fat in a goose fed upon Indian corn (maize), which corn 1 have alleged not to contain a thousandth part of fat or fatty substance. The ex- periments of M. Liebig, says M. Donne in the Journal des Debats, are throughout inexact and false, as MM. Dumas and Boussingault have obtained 9 per cent, of a yellow oil from Indian corn, which M. Dumas had the honour to exhibit to the Academy. Formation of Fat in the Animal Body. 27 It must be evident to every unprejudiced person, that the fact mentioned in the preface has no necessary connexion with the discussion, concerning the production of fat, in the work itself, or in the appendix ; it is not employed in the ar- gument. While writing the preface, a friend of mine com- municated to me the result of fattening geese with Indian corn. I found in the Jour, de Chim. Medicale, i. p. 353, an analysis of maize by Lespes, in which no trace of a fatty substance is mentioned. I further found by an examination by Gorham, in the * Quarterly Journ. of Science,' xi. p. 205, that maize contained a particular substance, which he called zein, which was extracted by alcohol and could not be fat, as, on the authority of Gorham, this zein was not miscible with fat oils. Gorham does not mention any fat oil. Therefore, according to every fact of which I was aware, maize contained neither fat nor any substance similar to fat. I had not myself at that time entered into any examination of it. The results obtained by MM. Dumas and Payen induced me, however, to undertake an examination of Indian corn, which was grown in my garden. 67 gram, of maize were exhausted by aether. The aether left behind, on evaporation on the water bath, 2'849 gr. of a thick yellow oil. The weight of this oil amounted to 4*25 per cent, of the seed. The difference in this experiment from that of MM. Dumas and Payen is very great ; 9 per cent, is so much that this seed might be used with advantage in the manufacture of oil. I consequently altered the mode of examination by a proceeding which insured a perfect extraction. The seeds were treated with dilute sulphuric acid kept at nearly a boiling heat until they had almost disappeared. The residue was washed, dried and exhausted by aether. 77 grm. produced in this man- ner 3*594' grm. of a substance soluble in aether. Maize grown in the fruitful fields of Giessen, therefore, does not contain more than 4*67 per cent. I found since also an analysis by Bizio (Brugnatelli Giornale, t. xv. pp. 127, 180) which gives for Italian maize 1*475 per cent of fat oil. Maize belongs to those seeds which produce a decidedly favourable influence on the formation of fat; some maize con- tains no fat (Lespes, Gorham), some contains above 4 per cent, of oil, and other maize contains 9 per cent, of fatty oil. According to each individual's view, arguments may be drawn from these observations favourable or unfavourable to the for- mation of fat in the animal body ; but as the analysis of the ex- crements of the geese was not made, they cannot be taken into account. 28 Mr. W. Kemp's Observations on the latest The fatty oil obtained in the Giessen laboratory from the seeds of the maize, completely dissolved in an alkaline car- bonate and formed a perfect soap ; it consisted of a fatty acid, which probably is formed by the influence of the air on the fat contained in the seed on its becoming rancid. According to the analysis of Dr. Fresenius, this oil consists in 100 parts of — Carbon 79*68 Hydrogen 11*53 Oxygen 8*79 and possesses, therefore, a composition similar to known fats. I consider it certain, that the fat which animals take in their food contributes to increase the quantity of fat in their bodies. We have of this certain and decided proof, in the patholo- gical treatment of persons who daily take a considerable quan- tity of cod-liver oil. I further consider it probable that oily fat may pass into crystallized fatty acids ; and Wohler's observation, that fusel oil from corn contains a considerable quantity of margaric acid, finds a satisfactory solution by the experiments of M. Mulder, which make the conversion of cenanthic acid into margaric acid probable. In the Giessen laboratory the observation was made some years ago, that the oleic acid, in the state in which it is ob- tained from stearic acid manufactories, produces upon rapid distillation more than the half of a fluid product which on cooling becomes as hard as tallow, and upon expression pro- duces 35 per cent, of margaric acid. These experiments, which are well worth a closer investi- gation, render it not improbable that hard tallow might be formed out of liquid crystallizable oil. Whether similar processes take place in animals, in relation to the formation of many of their compounds, to those that take place in plants, is hardly to be doubted. The observation by Wbhler of the giving out of oxygen by the infusoria, which led him to put the question, whether the nourishment of these creatures was not dependent upon a similar decomposing process to that of plants, might by ac- curate examination be soon brought to a decision. VIII. Observations on the latest Geological Changes in the South of Scotland. By Mr. William Kemp *. INHERE is certainly no department in geological investiga- - tion less understood, while at the same time there is none that has been more frequently treated of, than the last bene- * Communicated by the Author. Geological Changes in the South of Scotland. 29 ficent and beautiful re-modeling of the earth's surface, by which it was adapted for the habitation of man. All see and acknowledge that some powerful agency has been brought to bear upon it over its whole extent (during the aera) while it was slowly emerging out of the bosom of the troubled deep ; but various phenomena have been pointed to which the tidal wave and rapid currents could never accomplish. Floating icebergs and glaciers have of late been likewise alluded to by master minds of the science, which are now hailed by many, and as observation progresses, will throw much light upon certain phaenomena which formerly appeared so dark and dubious. It is with the greatest diffidence that the writer presumes to give his opinion upon such an abstruse subject, but the field is open to all ; and as the faculty of comparing and judging of cause and effect is not confined to the great and learned alone, obscure individuals have sometimes given hints which have led to splendid results, and he submits the following observations to the public from no other motive than an anxious wish for the elucidation of truth. He is aware that such a subject will attract little notice, unless introduced by some great familiar name; however, the pleasure arising from years of patient investigation has been a rich reward, let its reception be what it may. Perhaps there is no part of Great Britain where the later changes upon the earth's surface can be studied to greater advantage than the district around Galashiels. Upon every hand we have vast accumulations of boulder clay flanking the hills, together with beds of gravel and sand overlying the lower declivities, besides numerous examples of what is called crag and tail, profusely strewed over with erratic boulders radia- ting fan-like towards the east ; we have likewise broad and well-defined terraces high up the hill-sides, which in them- selves are objects of great interest; and lastly, there are the hitherto unaccountable, tortuous, angular ridges of gravel parallel with, or partly stretching across the valleys. All these taken together combine to give evidence well worth the attention of the profoundest intellect, as so many written cha- racters of a past aera of the world's history traced by the hand of that all-pervading Power, whom alone all the laws of na- ture obey. Placed in such a favourable locality for observa- tion, the writer has had his mind strongly impressed from time to time, as he followed up the investigation of the varied and striking appearances around him. His judgement may be at fault respecting the cause of some of those appearances, but at all events he would disdain to give willingly a woven tissue of theory unbased upon facts ; his conclusions, therefore, 30 Mr. W. Kemp's Observations on the latest are such as naturally arose from oft- repeated visits to the various localities, and from a careful examination of their posi- tion, formation, and general and particular features. Many hasty ideas had to be rejected as subsequent investigation proved them to be erroneous, and consulting writers was oft- times rather a stumbling-block than a furtherance. However, several writers of late seem clearly to have pointed towards the truth, though they commonly appear to impute too much to any one cause. The following are the deductions which the writer feels at present warranted to make from his own per- sonal investigations. Previous to the emerging of this island out of the bosom of the ocean, of course the greater portion of its surface would be bare rock, most likely strewed over with a considerable accumulation of stony debris; and whatever may have been the cause of the denudation, or scooping out of the lower valleys, it is evident that it must have been going on previous to, or at the time the higher hills were emerging above the surface of the water, for it is clearly evinced by the fact that the sub- sequent debris of the hills rests upon these lower tracks. Long before the emerging of the land, volcanic action had been very prevalent, as is shown by the numerous ridges and co- nical hills of trap, which have all been thrown up under a deep sea ; indeed there is no evidence of any one in all Britain having burst forth in the open air. But after these subma- rine eruptions had ceased, that mignty internal power which occasioned them was still in existence, and as its expansive force was no longer relieved by bursting through the surface, it seems to have acted in another manner and elevated simul- taneously the whole island. However, from various appear- ances we are enabled to conclude, that this elevation was not accomplished by a few overwhelming convulsions, but by slow degrees through the lapse of ages ; and indeed for anything we can know it may be still slowly progressing. The most striking peculiarity, and one which is very ob- vious to all observers, is that of oceanic currents having swept the detritus of the rising heights from west to east, so that it is universally seen flanking the eastern declivities of the hills, distinguished by that peculiarity of form known by the desig- nation of crag and tail. Such peculiarly formed accumula- tions are spread out in many places to a great extent and thickness; we have examined places where water has worn it down for about 100 feet deep in ravines, and along the sides of the valleys. It is the opinion of some eminent geologists that this boulder clay is of various ages, arising from a difference in the appearance of the mass j to this we give assent so far, that Geological Changes in the South of Scotland. 31 is, as to ages, but not as to different epochs of geological time; for as we have before stated, the scouring out of the valleys had taken place previous to the deposition of the boulder clay, as is clearly shown by the latter being less or more spread over the former. But there is another consideration which we cannot overlook ; the detritus seems all to have been driven in the same direction, and locally the boulders are mostly all of the same material . Again, it is so frequently interspersed with such huge masses of rock as are never found in any of the older strata, which gives strong ground for believing that those extraordi- nary masses have been struck off the prominent rock, and borne to a distance at a comparatively recent sera, by such a combi- nation of powerful agents as more primaeval time does not ex- hibit. At some places there is a well-marked distinction in the mass, where the lower beds differ in colour, and are more or less argillaceous than the superior ; the lower, likewise, rises with a higher inclination towards the hills, while the incumbent beds are generally of a lighter colour, and more arenaceous in com- position. We can frequently detect small boulders of foreign rock, such as sandstone, &c. of the coal districts, and various rolled fragments of the trap family ; the first must have tra- velled a great distance from the west, or north-west, while the latter may belong to the numerous trap dykes which intersect the district. These are chiefly to be found along the valleys, but seldom upon the steep escarpments of the hills. We com- monly observe that boulders of a large size are not so plenti- fully interspersed in the clay, where it has evidently been driven to a considerable distance, and where they do occur they do not appear to have been rolled. At many places we can scarcely pick out a boulder exceeding two or three lbs. weight, the deposit being a homogeneous mass of clay and small pebbles : in other places, where the debris has been driven to a considerable distance, the boulders are exceedingly well-rounded, while the opposite is the case with that resting upon the escarpments of the hills, where fragments of all sizes are seen indiscriminately mixed, with scarcely a rounded angle. But in order to understand these remarks, it will be neces- sary to examine the appearance of the hills, and describe their various features downwards. It is not requisite to point to the denuded summit of the hills with respect to this part of the subject, for that those summits have been much denu- ded is what none can deny, it being so striking and ob- vious to all. While the denudation was going on, the grosser debris would be forcibly driven over and rolled down the sheltered side of the declivities, and the finer water-borne 32 Mr. W. Kemp's Observations on the latest matter would be carried to a greater or less distance, accord- ing to its specific gravity ; so while the rocky fragments were being deposited upon the flanks of the adjacent heights, the finer sedimentary ingredients borne along from the more di- stant peaks would gradually subside and be deposited along with the grosser fragments ; and in this manner would the coarse and fine become indiscriminately mixed, as we find them. As the hills arose and their higher summits had be- come elevated above the action of the sweeping water, the cur- rents would take different directions from their former onward course, removing a part of the earlier wreck, which, together with the spoil still derived from the hills, would be laid over the more distant parts of the former deposit, containing many boulders more rounded and smoothed by attrition. At last, when the land became so far elevated that only partial currents swept through the lower straits, there would in many places be a still further remodeling, for the finer particles would be swept into sheltered localities according to circumstances, while the fragmentary debris would be rolled along and thrown up in banks of gravel. From the same denuding and sweeping cause do we account for the greater part of those large boulders, which are so plentifully scattered over the surface along the declivities to the east of the eminences, where in many moorish districts they lie yet unremoved. East from the village of Fans they may be counted in thousands ; and so thick do they lie upon the surface, that a person may almost walk along continuously from one to another. They are of all sizes, from a few pounds to several tons in weight ; the greater part are rather well- rounded, but that does not argue against the above theory, as there can be little doubt that many of them would be well smoothed over upon the one end before they were torn from the living rock, and upon examination many of them appear to have been so. Fans occupies a rather elevated situation, being built upon a broad flat knoll of hard crystalline green- stone. A quarry at the west end of the village opens up a fine view of the rock, which is of a beautiful columnar struc- ture. The columns are about 30 inches in diameter, standing nearly perpendicular, and although closely joined can be easily separated, which shows that its denudation would be much more easily accomplished than that of a rock of a more mass- ive structure ; and hence the vast number of these blocks radiating towards the east of that place. A question may arise, how comes it that those boulders are so thickly scattered over the surface — not imbedded in the clay, but lying upon it ? That question has already been partly answered. As the rock Geological Changes in the South of Scotland. 33 wore down, the fragmentary deposit behind becoming ex- posed to the current would be partly carried away, rolling the boulders further along, and finally leaving them upon the surface. At the same time it must be understood that they are not confined to the surface alone, as they are plentifully found at various depths. Such is that part of the phsenomena in question, which is the most obvious, and which has been so frequently treated of by various writers ; but there are other appearances yet to be noticed of an extremely interesting character, which, taken in connection with the foregoing, seem to shed a ray of light upon those long past revolutions of ancient time. In order to point to those we must again ascend the hills, and draw atten- tion to the deeply engraved characters upon their rocky shoulders. We here in the first place allude to the terraces, which in many places are so broad and well-defined upon the hills in the district around Galashiels*. The writer has care- fully taken the level of those various shelves from hill to hill, across valleys, &c, over a wide district, and has ascertained beyond a doubt that they are correctly level or parallel in elevation throughout. The cause is very obvious why those terraces have remained so long undiscovered ; their situation is very different from those celebrated ones of Glen Roy ; at the latter place they are visible to the spectator for many miles along the steep grassy banks of that Highland glen. But here no such appearance is presented to the eye, as we have no continued range of hills ; the highest are only a few insulated peaks, overtopping a number of rounded and irregular undulating hills; it is only upon some of the sides and projecting shoulders of these that those terraces are to be seen. He that would wish to survey them, requires to provide himself with a proper levelling in- strument, and to travel patiently from hill to hill, and then, but only then, will he be satisfied with the truth of our as- sertions : we proudly appeal to those faithful and enduring witnesses, whether for or against us. These terraces are not a single range but a series, extend- ing from the summit of the hill downward ; they average 54 feet in perpendicular height one above another, some less and others more. We assume each of those to have been success- ively the level of the ocean for an indefinite period of time. We do not mean to state that the land had been raised 54- feet at once by any sudden movement ; but that during its eleva- * For a more particular account of those terraces, see Chambers's Edinburgh Journal, No. 444. Phil. Mag. S. 3. Vol. 23. No. 149. July 1843. D 34- Mr. W. Kemp's Observations on the latest tion it had been stationary at those levels for a longer period than while it was emerging through the less-worn spaces be- tween. It is a remarkable feature in those terraces, that they can scarcely be traced but upon the north and south project- ing shoulders of the hills, such as have been most exposed to the sweeping currents from the west. The most distinguished of those terraces is one upwards of 800 feet above the level of the sea ; as a great number of our lesser hills considerably exceed that height, it might be expected to be pretty generally marked ; and not only is it so, but in a very remarkable degree. Ac- cording to the situation of the hills, we have traced it from where it was merely visible to where it was 300 feet broad ; in many places it exceeds 100 feet, and everywhere it seems chiefly scooped out of the solid rock. As we ascend to the superior levels, the traces of each terrace become fewer and more distant as they overtop the hills ; still upon some higher eminences they are very well defined, as for instance where they are so remarkable upon the north side of the Eildon hills. From the first-mentioned terrace downwards they become gradually less and less distinct, which is a further confirma- tion of the theory in question, because the abrading action would become gradually less powerful as the land towards the west arose and checked the current. Owing to the detached and rounded form of the hills, those shelves are nowhere of any great length ; few of them exceed 300 yards, and many are not so much. However, upon Ruberslaw, a high conical hill about 6 miles west from the town of Jedburgh, there are two terraces upwards of 800 paces in length by 30 in breadth, and another 600 still broader. These are very beautiful, and in some respects they are the finest in the district. To the east is the valley of the Rule, and on the other side the ground rises to a high ridge, extending eastward to the town of Jed- burgh. Near the north summit of this ridge, a finely marked terrace runs along its whole length, which is about 1^ mile, and which correctly corresponds with one of those upon Ruberslaw ; indeed so truly does it agree with the instrument, that we can detect no deviation along its whole course. Let us conceive in the mind's eye an immense body of rushing water sweeping along like a mighty river, would that be sufficient to account for those terraces ? certainly not. We cannot suppose that flowing water alone would run out those shelves, as it would scour indiscriminately the surface over which it swept, or rather it would act more powerfully upon the lower depths by the superincumbent pressure of the water. Then let us suppose that the sea was comparatively tranquil, just as it is at present, being occasionally raised into fury by Geological Changes in the South of Scotland. 35 the driving blast : on this supposition, the lashing of the stormy waves together with the tidal action would certainly in the course of time excavate a beach of less or greater mag- nitude, according to the nature of the ground and its exposed situation. But a close observer must reject that idea also, as he will at once perceive that powerful currents must have swept along, which is incontestably proved by the vast mass of ruins so universally thrown to the east, enough in many cases to afford material for a city. During our first examination of the terraces, we were frequently puzzled by a singular appear- ance they presented.' In almost every case, whether those shelves were of greater or less extent, their extremities were always observed to be rounded over, especially at their west- ern end, and whenever the ground trended back, they still kept a nearly straight course by bending down hill for some distance. From this mysterious form and other inexplicable appearances, we were, after repeated examinations, at last obliged to abandon the idea of water alone having run out those terraces. Early in the spring of 1841, as the writer was wandering upon one of the finest scenes of the kind in the district, it then occurred to him, that probably floating ice- bergs was the cause of the extraordinary denudation around him ; gradually the mystery seemed to vanish, and shortly after he became so thoroughly convinced of the truth of the theory, as to be surprised at his obtuseness of intellect in not having caught the idea earlier, so plainly did that place seem to tell its own tale. The scene alluded to is upon a saddle- backed ridge or spur of Williamlaw hill, which stretches its denuded spine and terraced front boldly south into the Gala valley. The grooving over the summit of that ridge is the most remarkable of any we have seen ; at one place the rock is worn down about 10 feet below the adjoining strata, and 36 feet broad. The rock everywhere bears strong marks of attrition. The grooving runs in the direction of the tilted strata, which is nearly east and west. The west side descends at an angle of 26 degrees, and the grooving continues downwards for about 76 feet, gradually diminishing in depth as it descends. The east side has much the same appearance, but is nothing like so strongly marked. Some adjoining ledges of great hardness project several feet high, completely rounded over. The rock is greywacke, the strata nearly vertical, and harder than many kinds of granite*. That place is by no means a solitary in- * In the face of this evidence, there are not wanting some who assert that the rounded form of those prominent blocks has been occasioned by weathering, " for (they say) had the place been subjected to the powerful denudation of floating icebergs, the surface would have been as smooth as a D2 86 Mr. W. Kemp's Observations on the latest stance of the kind ; it is certainly unequalled in this district for showing much in little space ; however, we could point to many places having the same characteristics, and many of them scarce inferior in appearance; and as all the terraces are rounded over in the same manner at their extremities, we may infer the cause to have been the same. Moreover, all these are highly elevated and exposed to the open west, where float- ing icebergs borne along by a tumultuous sea would strike orF and abrade the rock exposed to their action with almost irre- sistible force ; and as masses of considerable size sail deep in the water, their bottom would first strike the ground, and be driven over the still sunken ridge with vast increased press- ure*. Such a process going onward for an unknown period of time, for a few months in each succeeding year, seems clearly to account for these phasnomena, and we should think that the most sceptical would concede to it upon inspection. There is another division of the subject which has attracted much attention, and one which we think cannot be solved without the aid of floating icebergs. We now allude to those large angular masses of stone which are so frequently found in situations far from the parent rock, and which differ very much in appearance from such rounded boulders as have been rolled along the declivity behind the height they were torn well-polished flagstone, and all the protuberant blocks would have been dressed down to an even surface : " as proof, they allude to such polished surfaces upon the Swiss Alps. In answer to the above objections, in the first place we must admit of weathering to a certain degree ; however, it is known that the hard blue rock in this district almost defies the penetrating tooth of time. There are many old towers in the neighbourhood built with that stone, whose aged walls have withstood the vicissitude of the seasons for many ages, and where the edges of the stones are as sharp, and the dint of the hammer as legible as if they had been erected recently. Besides, we have examined rocks that had been previously covered with a coating of debris, which presented the same rounded appearance. In the second place, why compare this rock with granite ? Granite being an unstratified rock, con- sequently if not upon a steep precipice, will almost resist any conceivable power to tear it away, except the mechanical wearing down of the surface; hence its polished appearance. But very different is the case with the broken edge of the stratified greywacke, where in this district few of the beds exceed 18 inches in thickness ; besides, the beds are crossed in all di- rections by fissures (joints'), so that the larger blocks may resist denuda- tion for a time; at last they are borne away, but a hollow is left in their place, while the next in height becomes prominent until it yields in its turn, and so on continually. * We were much pleased to see the same idea taken by that able geo- logist, Mr. Maclaren. Describing the striated rocks of Corstorphine hill, he says, " An iceberg, for instance, deep enough to scratch the lower part of the slope, and forced by a current over the higher level, must have been partly lifted out of the water, and its pressure here would be enormously augmented." — Scotsman Newspaper, June £5, 1842. Geological Changes in the South of Scotland. 37 from. Of course they have all taken the same direction, but those alluded to retain angles so sharp as to forbid all idea of their having been rolled. Besides, such are frequently perched upon situations quite adverse to the rolling theory : we some- times meet with such amongst the round boulders upon the surface, and not unfrequently in the boulder clay, so very flat and angular, that they must have been borne there by a very different conveyance from the others. We need not dwell upon this part of the subject which has been so frequently treated upon by far abler writers, we shall therefore pass on with pointing to one remarkable instance. There is a large angular fragment of green-stone seemingly upwards of ten tons in weight, close by the side of the old road to Jedburgh, and about a mile south from the Teviot. Upon comparing specimens we find that it must have come from Ruberslaw, a high hill about seven miles direct west. The deep valley of the Rule intervenes, besides a considerable extent of rising ground, so that the stone must have been floated over and dropt upon the spot it now occupies. It is in two pieces which are separate a few inches : that fracture possibly took place when it fell upon the ground ; certainly it has not been broken recently, and not likely ever by the hand of man. We now come to the last, but certainly not the least, inter- esting feature in the district, that is, the mounds or moraines of gravel which from time to time have elicited so much specu- lation, but which have until of late as it were mocked all at- tempts to account for their formation. The honour of having first interpreted their true character is due to M. Agassiz, the celebrated Swiss philosopher, whose experienced eye soon de- tected them upon his memorable visit to this country. Those mounds stand out in bold relief, often in a tortuous steep ridge- like form, which, together with the local situations where we find them, at once testify that they have been thrown up by a very different cause from any which have yet been alluded to. They are totally distinct from the debris which have been swept into the rear of the hills by the combined action of water currents and floating icebergs. The latter is commonly a broad undulating mass, sloping to the east of the rocky heights ; or behind a conical hill it takes the form of a flattish rounded ridge, denominated the tail of the crag, which is often flanked with gravel in low swelling undulations. But those mounds now under consideration are frequently as narrow, high and steep as the loose material composing them will admit of. We cannot suppose water to have thrown up those mounds into such a sharp ridge, so equal in breadth,, so tortuous in their course, and of such a length as some of them are. More- 88 Mr. W. Kemp's Observations on the latest over, they frequently extend across valleys where currents of water had formerly swept along. There are some very con- spicuous moraines to be seen in this district ; in the valleys of the Tweed, the Teviot, the Ettrick, and the Gala, &c. As examples of such we point to those very fine ones near Gala House, and the Fairy knolls by the Allen water. A very re- markable one extends partly across the valley a little below the town of Galashiels; it exceeds 140 feet in height by 600 feet in length, extending from the north bank at a right angle across the valley: that is only its remains, for it is evident that it had once crossed from side to side, for opposite upon the top of a high bank a portion of it is still very prominent. However, as it would form a barrier to the Gala, it has sub- sequently carried a great part of it away. The turnpike road passes over the north end of this mound, and as its steepness there has long been a cause of complaint, last summer work- men were engaged in excavating the height, and have opened up a highly interesting section about 12 feet deep where it bends to the west, adjoining what may be termed the lateral moraine. At the east side, below a mass of gravel and sand, there is exposed a large quantity of rolled stones each from about 5 to 13 pounds weight, which appear as if they had been tumbled together without any admixture of smaller ma- terial, so that we may thrust in our hand between the boulders. These are seen along the lower edge of the cut about 1 4* feet, and 3 feet high, — how deep we cannot say. The bank above those stones, although having visibly a stratified appearance of small and coarse gravel alternating with intervening por- tions of boulder clay, is yet so strangely contorted, especially a little further west, where the thin beds of fine gravel become quite vertical at more than one place, as to confound all idea of its having been finally laid there by aqueous deposi- tion. In fact we have therein displayed the formation of that mound in characters infinitely easier to understand than those of the ancient Egyptians. It is well known that a glacier bears a considerable quantity of debris upon its surface, which it grinds off the ground in its course, beside what rolls down upon it from the adjoining bank; in this case we see that a current of water has run along its surface carrying away the lighter material, while the glacier bore along the grosser debris which would be deposited at the extremity. Anon the water has changed its course, while sand, clay and stone were next deposited, and so on alternately in a greater or less degree ; and after that semi-stratified mass was laid there, the immense pressure of the glacier had thrust it up in the contorted man- ner above described. Geological Changes in the South of Scotland. 39 Perhaps there is not a finer example of those moraines in Britain than that celebrated mound known by the name of the Bed Shiel Karnes : that beautiful moraine, taking in all its sudden bendings, is about 2£ miles Jong ; its height is from 15 to 60 feet; besides, a great part of it is buried to an un- known depth in the morass. It runs along the middle of an extensive swamp called Dogton Moss in Berwickshire, about 3 miles north from the village of Greenlaw, and near the south base of the Lammermuir hills, from whence the debris com- posing it is chiefly derived. Having lately been informed by a very intelligent gentle- man at Rule water, that he supposed he had discovered a fine moraine in the south border of Roxburghshire, in a late tour, in following up other investigations in that district, we made a point of visiting that locality, and were not disappointed. By its striking appearance we soon caught a view of it, although still at a considerable distance, by the aspect of the vegetation which clothed it, which differed so much from the neighbouring hills, or the black heathy moor around it. As we approached the place we found the gentleman's account of it to be exceed- ingly correct ; it is situate upon the lower corner of an up- land vale which rises with a considerable acclivity towards a crescent bend in the Carter fell, which is about a mile distant south. Close by the moraine to the north-west and west, the ground rises rather rocky and precipitous to a height of about 40 feet ; two small mountain burns join their waters at a short distance behind the moraine, and run down a narrow gorge that the mound must once have choked up; but those streams have subsequently cleared their way and rounded the mound to its present form. However, it is evident that ages have elapsed, and may again roll by, without those tinny rills making any further alteration upon it. That mound is known by the name of the Scaud-law ; it is of a circular form, about 635 paces in circumference, and 80 feet high. From base to summit it is wholly composed of the rocky debris of the neighbouring hills, which debris is of all sizes, from coarse sand to blocks of many ton weight, consisting of sandstone, shale and lime, confusedly tossed together, lying at all angles, and peering out of the surface like tombstones in a country church- yard. We have been particular in describing this singular mound, as we deem it one of the strongest evidences of the glacier theory we have witnessed. The drifted debris there as well as elsewhere seems likewise to have been driven to the eastward, but that composing this mound has been carried in a nearly opposite direction, that is, to the north-west. Nor is that a so- 40 Latest Geological Changes in the South of Scotland. litary exception ; for wherever we have observed those mounds, they are always situated according to the natural declivity of the ground in the vicinity of elevated ranges, without regard to any direction. We could direct attention to many more of a similar character, but as we have drawn out this paper to a greater length than was anticipated, we hasten to conclude as briefly as possible with a recapitulation of the principal points. When the summits of our hills were emerging out of the ocean, strong currents (perhaps periodically), accompanied with numerous floating icebergs, seem to have been furiously driven along, denuding their summits and sweeping the debris to the east, forming the beds of boulder clay commonly de- nominated til ; still as the land was upheaving and the higher peaks rising above the denuding action, the onward wave and ice, ever lashing against their western faces, rendering them bare and precipitous, and sweeping round their sides, cutting out the rocky terraces, grinding down and rounding over those saddle-backed ridges as they were raised to near the surface, while occasionally from some overhanging precipice masses of the rock would fall upon the ice, and be borne along with it until its floating raft gave way, or until it was dashed from its seat and dropt upon the bottom. Anon, while the land by inter- nal throws was rising step by step, a part of the older ruins would be removed to a greater distance, and be again lodged over its lower flanks, and while the lighter debris was being swept away, the larger blocks would be further rolled along and finally left upon the surface. And lastly, by shallower currents, part of the debris, where it was exposed to their ac- tion, would be further removed, and thrown up in beds of sand and gravel into sheltered situations. In the course of time, when the valleys had become elevated above the ocean, the accumulating snow upon the hills would commence descend- ing down the declivities in the glacier form, to those land straits where the moraines are still to be seen, bearing along with them a part of the debris which they had collected in their course, and finally retreating after their beneficent task was accomplished, leaving those imperishable records to attest that they had once been there. . We understand that the glacier theory is rejected by some, who reason in this manner : — Animal and vegetable life, during the rem of the carboniferous system, was such even in our northern latitude as could only have existed in a climate such as the tropics, and although a progressive change had been going on until the aera of the newer tertiary, still even then it had been much above the present. We hold that argument Mr. M. Roberts on the Electric and Nervous Influences* 41 to be by no means conclusive, but rather the reverse: during the tertiary formation our island had been submerged in the bosom of the ocean, and as we know not how many ages may have elapsed between that period and its subsequent elevation, may not the temperature in that interval have been reduced to a sufficient degree as to become suitable to the formation of glaciers ? Certainly, without seeking proof for either side, which is not yet obtained, we may as readily ad- mit that at the asra in question the temperature had been a few degrees lower than it is at present, as that at the car- boniferous epoch it had been so much higher ; for any thing we know there may be a cycle of change going onward in the roll of time unknown to man, who seems to be but a creature of yesterday. But to conclude : do we not see in those later changes a great and grand design ? Had the land been elevated with all its hard and serrated rocks unreduced by attrition of a very powerful kind, what may we suppose it to have been but so many piles of rugged rock, ever and anon sending down some loose fragments covering over their flanks with a totally barren and impenetrable crust, rendering the greater part for ever a howling desert? We see that the whole operation has been guided by a mighty mind ; the various elements of nature have each been called upon to act their destined part, and well we see they have been performed. What is more beautiful than our finely rounded hills, covered with verdant turf to their very summits, together with the smoothed undulating uplands, and the fertile and smiling valleys, altogether forming a rich and beautiful dwelling for man ? Galashiels, Jan. 25, 1843. WlLLlAM Kemp. IX. On the Analogy between the Phenomena of the Electric and Nervous Influences. By Martyn J. Roberts, Esq., F.R.S. Ed* [Continued from vol. xix. p. 38.] 31. TN my last communication on this subject I pointed out the striking analogy that exists between the nervous and electric influence as displayed in the action of electricity upon fluids flowing through capillary tubes, — the corresponding ac- tion of nervous influence upon the circulation of the blood through capillary vessels, — the explanation the phaenomena of inflammation receives from this view of the subject, — the elucidation of that of turgescence ; — and the probable cause of * Communicated by the Author. 42 Mr. Martyn J. Roberts on the Analogy between suffusion in the act of blushing was shown when the action was viewed as analogous to or identical with electric phaenomena. I now proceed to consider this analogy as displayed in reflex action, premising that at present the heads merely of the theory are given, reserving for a future occasion the development of the subject in its fullest details. Theories are often condemned without a hearing by some who pride themselves upon being mere practical men, to such with all due respect I will quote the words of a learned author: "Where a definitive explanation of phaenomena is yet impossible, an hypothesis which is not op- posed to the facts, but on the contrary accords with them and which opens a new field for research, is admissible even in an exact science founded upon facts." 32. We may consider reflex action as merely motion ex- cited in muscles by irritation of sensitive or incident nerves in these or adjacent parts, and that sympathetic action is motions referrible to the same cause. All these reflex motions, whether of the sympathetic or other parts of the system, appear to me to bear the closest resemblance to electric induction, and that the current in the sensitive and incident nerves induces an ac- tion in the nerves of motion that lie contiguous to them. S3. Suppose A A to be a wire through which a current of electricity can be passed, and that A————— —————— ——A another wire, B B, placed close to P ^ B the first forms part of a closed cir- cuit that is offering a perfectly con- tinuous path for the transmission of the electric fluid ; then if a current be passed through A A in the direction of the arrow, it is found that at the moment of the first passage of the current it creates or "induces" another current in B B, and in a direction contrary to the primary current in A A; but this secondary or induced current is only of momentary dura- tion, no trace of its existence appearing after the first instant of passage during the whole continuance of the primary cur- rent; nevertheless the moment we annihilate the current in A A a new current is induced in B B, but in an opposite direction to the first induced current. Such are some of the phasno- mena caused by the action of a current of electricity upon neigh- bouring conductors, and such also there can be no doubt is the action of nervous currents upon nerves contiguous to others conveying these currents. 34. It will be seen that one condition necessary to the pro- duction of these phaenomena in wires by electricity, is that of a perfect continuity for conduction in the channel conveying the electric fluid ; for if the wire B B be broken no current can be induced in it; and I think it will be found the Phenomena of the Electric and Nervous Influences. 43 That every voluntary motor-nervous filament forms a di- stinct closed circuit. That every sensitive filament forms a distinct circuit. That every incident filament forms a distinct circuit. That every reflex filament forms of itself a distinct closed circuit. That every incident filament of the sympathetic system (if I may be allowed the expression), which conveys the impres- sion to its centre, forms in itself a closed circuit; and lastly, that every reflex sympathetic filament in proceeding from its cen- tre forms a closed circuit. These several nerves are each of them looped at the extre- mity of their course, and no doubt looped in their centre, such as the spinal cord ; and it is highly probable that the mass of the spinal cord is but a congeries of these loops completing the circle, or at all events that the mass of the gray matter closes the circuit of the several nerves leading into it. If a nerve be divided all reflex action ceases, because the conditions neces- sary to the production of inductive action no longer exist. 35. Another condition necessary to galvanic induction, is contiguity of the channels conveying the primary and the in- duced currents. It will be found that reflex motion exists only in muscles whose motor nerves are contiguous to those sensi- tive or incident nerves which conveyed the impression of the irritation that produced the so-called reflex motion. I might venture to assert, that in most instances where reflex action is produced, the nerves conveying the impression and those of motion are bound up in the same sheath ; and it is probable that the plexuses in the axillary and inguinal region of animals are for the purpose of adjusting these nerves in their conti- guous groups before their distribution to the organs. I have used the term " reflex," it being a word well known as desig- nating this species of involuntary motion ; but I would be in- clined to prefer the expression of induced motion for all that class of nervous action which proceed from the centre to the periphery, excited by currents in the sensitive and incident nerves proceeding from the periphery to the centre. 36. The conditions necessary for inductive action having been shown strictly to exist in nerves that produce involuntary motion, it can also be demonstrated that the peculiar action produced by induction occurs whenever involuntary, reflex or induced motion is produced : in Section 33 it has been shown that electrically induced currents are of momentary duration, and of a like kind are all involuntary motions ; even tetanus is a rapid series of spasmodic interrupted contractions. We have also illustrations of these interrupted actions in the rhythmic 44 Mr. M. Roberts on the Electric and Nervous Influences. pulsation of the heart, the action of the alimentary canal, the ducts of glands, and, in short, in most of the muscular con- tractions of the organic life. 37. When speaking of these as " reflex actions," I do not in using their term follow the theories of either Prochaska or Dr. Marshall Hall*, who have classified these motions under this head : so far from agreeing with Dr. Marshall Hall in consi- dering the spinal cord as the seat of the power of reflex action, I believe it merely closes the circuit of the nerves; and when we find reflex action suspended, from injury to the spinal cord, it is not that the seat of power has been destroyed, but that the closed circuit (as explained in sect. 34-) has been broken, and that the spinal cord is not more essential than any other part of the circuit to the production of induced motion. 38. A case of pure induction of one nerve upon another, and this attended with the peculiar phasnomena of an induced ac- tion produced by the annihilation of the primary current (sect. 33), may be shown by a simple experiment : — Place a piece of zinc upon the tongue and a piece of silver between the upper gums and the upper lip ; turn the eyes towards a dark place ; then, while the metals are in this position, bring their contigu- ous extremities together : at the moment of contact a bright momentary flash of light will be perceived; continue the con- tact, and the sensation of light ceases ; but separate the metals, and now a bright flash of light is again perceived at the instant of separation. Here then we have an excitement of the gusta- tory branch of the fifth pair which induces an action upon the optic nerve, all sensation in which appears to us as light, But it is worthy of observation, that this induced action is only at the first moment of irritation of the gustatory nerve ; for al- though the contact of the metals is continued, and consequently a galvanic current is constantly circulating through this nerve, yet no light is perceived ; but separate the metals, we then stop the current of electricity, and at this very moment another flash is seen. What can be more analogous, (may I not say identical?) than these nervous phaenomena with the case of electric induction in sect. 33 ? it cannot be said that this is only an effect of the irritation of the optic nerve by the cur- rent of galvanism ; for were this the case, the sensation of light would be continuous during the passage of the electric current ; whereas we find it apparent only at the moments of making and breaking contact; and beside, the galvanic current is not applied to the optic nerve; indeed, we have a flash when the * On Dr. M. Hall's theory of the reflex action, see Phil. Mag. S. 3. vol. x. p. 51. — Edit. Notices respecting New Books. 45 current ceases, and therefore it cannot be the irritation caused by it that produces the sensation oflight. 39. If light impinge on the iris only and not upon the re- tina, no contraction of the iris ensues ; but if it fall upon the re- tina, then the iris contracts, even if no light has access to the iris itself; therefore the motions of the iris are governed by sensations traversing the optic nerve, and this sensation induces a current in the motor-nerves of the iris. 40. In the motions of respiration induced by the action of the atmospheric air on the incident nerves of the lungs, in the contraction of the sphincters by the induction of the nerves irritated by the contents of the canal or bladder, — in cough- ing from irritation of the larynx, in sneezing from irritation of the nose, and in many like instances, we see cases of induced motion; and these facts, with those I have before adduced, may at present suffice to point out the perfect analogy, if not iden- tity, between the nervous and electric influences : the more ex- tended details of its application to many other interesting vital phaenomena in the healthy and diseased condition of organic bodies will be given hereafter. London, Jan. 5, 1843. X. Notices respecting New Books. Lectures on Chemistry, illustrated by 106 Wood cuts. By Henry M. Noad, Member of the Chemical and Electrical Societies of London ; Lecturer on Chemistry ; Author of Lectures on Electricity, &c. WERE it possible we would gladly bestow commendation on any attempt, however humble, to enlarge the boundaries of science ;' but when books are presented to the public, we must, if we notice them at all, speak of them as we find them. It is with regret that we are obliged to withhold our approbation from the work, the title of which is above given ; but we are sure that when we have pointed out its true nature, the author himself will scarcely be surprised at our opinion, and that the public will agree with us that this book has been got up with too great haste or too little knowledge ; and in some cases we think it will appear that both these formidable obstacles to a successful undertaking have lent their combined aid. We cannot afford sufficient space to notice the numerous state- ments which require correction ; we shall, therefore, offer a few ob- servations on the author's History of Chemistry, and then confine ourselves chiefly, if not altogether, to the chapter on oxygen, as af- fording numerous instances of inaccuracy on a subject of great in- terest, and yet nowise complicated or difficult. In the historical sketch, of which the first lecture consists, an ac- count is given of the labours of nearly forty chemists ; with all of these but one, discordant as their theological opinions must have 46 Notices respecting New Booh. been, our author seems to agree, for Dr. Priestley alone is selected for reprobation on this subject, with which, we may remark, the author had no business to intermeddle. It is, he says, " upon his philosophical writings the reputation of Dr. Priestley must rest ; his theological opinions are most deservedly condemned." Does the author thus go out of his way to anathematize Dr. Priestley for heterodoxy, lest his own reputation for orthodoxy* should suffer by having lauded the Doctor's discoveries in science ? We cannot imagine the existence of any motive more favourable or more weak. We may remark that no mention is made of the labours of the late and lamented Dr. Henry ; and Dr. Wollaston is stated to have died in the 53rd instead of the 63rd year of his age. We now proceed to consider the chapter on oxygen, and in page 140 the following statements occur : " Every human being on the face of the earth consumes nearly twenty- five cubic feet of oxygen every twenty-four hours (45,000 cubic inches daily, according to Lavoisier, Seguin and Davy), and one hundred weight of charcoal requires for its combustion thirty-two cubic feet, yet notwith- standing this immense hourly consumption, the quantity of this essential principle is not diminished in the atmosphere, but bears the same proportion to the nitrogen the other ingredient, now, as it did centuries ago." We shall not object to the statement that 25 cubic feet of oxygen are in twenty-four hours consumed by every adult, but we may ob- serve that this quantity is equivalent to only 43,200 instead of 45,000 cubic inches. The experiments of Messrs. Allen and Pepys give only 39,354 cubic inches, while according to Liebig's statement, that 14 ounces of carbon are daily discharged from an individual, the oxygen consumed in twenty-four hours will amount to 47,480 cubic inches ; we will therefore take Mr. Noad's statement of 25 cubic feet, which would combine with nearly 12- 75 ounces of carbon ; if then 12" 75 ounces of carbon require 25 cubic feet, 112 pounds of charcoal, or 1792 ounces, will combine with three thousand five hundred and thirteen cubic feet of oxygen, instead of 32, as stated by our author. It is not easy to imagine how so enormous a blunder could have been perpetrated in the first instance, but it is truly marvellous that it did not occur to the author in correcting his proof, that according to this statement " every human being on the face of the earth " must by respiration give out ff of 112 pounds of charcoal, or 87£ pounds in every twenty-four hours. The assertion of Mr. Noad, though probably true, that the quan- tity of oxygen in the atmosphere is the same that it was centuries ago, is utterly incapable of proof.; for oxygen itself not having been discovered 70 years, we presume Mr. Noad will admit that no ex- periments could be made on its quantity before it was known. There is much requiring correction in the author's statement re- specting the means to be employed for procuring oxygen gas : for ex- ample, we are informed that a pound of peroxide of manganese of good * As he sets up for an authority in theology, it is to be hoped he is freer from errors on the subject than we have found him to be in chemistry. Royal Society. 47 quality will yield four gallons of oxygen gas, and that this is about "the maximum obtainable quantity." But the author states that 1638 grains of peroxide of manganese yield 200 grains of oxygen gas, consequently 7000 grains, or one pound, will give 854 grains ; then as 34"4 grains occupy 100 cubic inches, 854 grains will give 2482 cubic inches, which divided by 277 \3, the cubic inches in a gallon will give 8-^ gallons of oxygen gas. Of course this is supposing the per- oxide of manganese to be pure ; but even if the impurity amounts to 50 per cent., the quantity of oxygen will be greater than that stated as the maximum obtainable from peroxide of " good quality." Mr. Noad also states that the 1438 grains of oxide left after heating 1638 grains of peroxide of manganese is " a mixture of 992 grains of deutoxide and 446 grains of protoxide of manganese." The fact however is that the 1438 grains are red oxide of manganese, which are certainly equivalent to, but are not a mixture of, the two oxides named, for deutoxide cannot exist at the temperature re- quisite to produce 1438 grains of red oxide from the stated quantity of peroxide. Several errors occur in the author's statements respecting the production of oxygen gas from chlorate of potash : we are informed that half an ounce (218*75 grains) should yield 270 cubic inches of oxygen gas, he having just before stated 1532 grains yield 600 grains of oxygen, 218*75 therefore give 85-7 grains, measuring only 249 instead of 270 cubic inches. The following note on this subject at p. 144, exhibits an extraor- dinary degree of confusion of per-centage, weight and measure : — " I find that the best chlorate of potash yields from 96 to 98 per cent, of pure oxygen." For some time we were puzzled to attach any meaning to this statement, but at length we concluded that the fol- lowing is what the author meant : — " I find that 100 grains of the best chlorate of potash yield from 96 to 98 cubic inches of pure oxygen gas." Confusion of a somewhat similar kind, though not quite so glaring, is observable in the following statement : " from an equivalent of the oxide [of mercury] we get 100 grains, or nearly 300 cubic inches of oxygen gas, and 1266 grains of mercury are found in the re- ceiver." It should have been stated that from 1366 grains, which may be considered as representing an equivalent: but according to the author's method equivalents are not relative merely, but absolute weights. We had noted many other statements contained in this work for observation, but the length to which this notice has extended pre- cludes our further proceeding. XI. Proceedings of Learned Societies. ROYAL SOCIETY. [Continued from vol. xxii. p. 490.] Feb. 23, r I ^HE following papers were read, viz. — 1843. ■*• 1. " Researches on the Decomposition and Disinte- gration of Phosphatic Vesical Calculi ; and on the introduction of 48 Royal Society. Chemical decomponents into the living Bladder." By S. Elliott Hos- kins, M.D. Communicated by P. M. Roget, M.D., Sec. R.S. The object of these researches was the discovery of some chemi- cal agent, more energetic in its action on certain varieties of human calculi, and less irritating when ejected into the bladder, than any of the fluids hitherto employed. These indications not being fulfilled by dilute acids, or other sol- vents which act by the exertion of single elective affinity, the author investigated the effects of complex affinity in producing decompo- sition, and consequent disintegration, of vesical calculi. For this purpose an agent is required, the base of which should unite with the acid of the calculus, whilst the acid of the former should combine and form soluble salts with the base of the latter. The combined acids would thereby be set free in definite propor- tions, to be neutralized in their nascent state, and removed out of the sphere of action, before any stimulating effect could be exerted on the animal tissue. These intentions the author considers as having been fulfilled by the employment of weak solutions of some of the vegetable super- salts of lead ; such as the supermalate, saccharate, lactate, &c. The preparation, however, to which he gives the preference, is an acid saccharate, or, as he calls it, a nitro-saccharate of lead. The salt, whichsoever it may be, must be moistened with a few drops of acetic, or of its own proper acid, previous to solution in water, whereby alone perfect transparency and activity are secured. He furthermore states, that the decomposing liquid should not ex- ceed in strength one grain of the salt to each fluid-ounce of water, as the decomposing effect is in an inverse ratio to its strength. Having by experiments which are fully detailed ascertained the chemical effects of the above class of decomponents on calculous concretions out of the body, the author briefly alludes to the case of three patients, in each of whom from four to eight ounces of these solutions had been repeatedly, for weeks together, introduced into the bladder, and retained in that organ without inconvenience for the space of from ten to fifty minutes. It not being the intention of the author to enter into the medical history of these cases, he merely cites the above facts as sufficient to establish the principle originally laid down ; namely, chemical decomposition of phosphatic calculi, by means of solutions so mild as to be capable of retention in the living human bladder without irritation or inconvenience. 2. " A Method of proving the three leading properties of the Ellipse and the Hyperbola from a well-known property of the Circle." By Sir Frederick Pollock, Knt., F.R.S., Her Majesty's At- torney General. Communicated in a letter to P. M. Roget, M.D., Secretary to the Royal Society. In this communication, the author first demonstrates the well- known property of the circle, that if from a point in the diameter produced there be drawn a tangent to the circle, and from the point of contact there be drawn a line perpendicular to the diameter ; and Royal Society. 49 if from any point in the circumference there be drawn two lines, one to the point without the circle, and another to the foot of this perpendicular, the former of these lines will be to the latter, as the distance of the point without the circle from the centre, is to the ra- dius of the circle. By means of this property, and assuming that the ellipse is the curve whose ordinate, at right angles to its axis, is to the corresponding ordinate of the circle, described upon this axis as a diameter, in a constant ratio, the author proves the following propositions relating to this curve : — 1. The rectangle of the abscissae is to the square of the ordinate, as the square of the semiaxis major to the difference of the squares of the semiaxis major and the excentricity. 2. The distance of any point in the curve from the focus, is to its distance from the directrix, as the excentricity is to the semiaxis major. 3. The sum of the distances of any point in the curve from the two foci is equal to the axis major. By a method nearly similar to that employed for the ellipse, and assuming that the hyperbola is a curve in which the rectangle of the abscissas is to the square of the ordinate, as the square of the ordi- nate in a circle, described upon the axis major as a diameter, is to the square of the subtangent, the author shows, first, that the distance of any point in the curve from the focus is to its distance from the directrix, as the distance between the foci is to the axis major ; and secondly, that the difference of the distances of any point in the curve from the two foci is equal to the axis major. 3. " On the diurnal Temperature of the Earth's surface, with the discussion of a simple formula for ascertaining the same." By S. M. Drach, Esq., F.R.A.S. Communicated by John Lee, Esq., LL.D., F.R.S.* The author investigates the several causes which influence the daily temperature of any point at the earth's surface. He employs the term Thermal establishment to denote the retardation of the effects of solar light caused by atmospherical conduction and by local cir- cumstances, in the same manner that the term Tidal establishment has been used to express the local constant by which the astronomical effects on the waters of the ocean are delayed. After explaining the formation of the tables and diagrams given at the end of the paper, and detailing the conclusions derivable from them, the author enters into a review of the perturbing causes, investigates the analytical expression for the daily heat, and concludes with some observations on isothermal lines, on the influence of the friction resulting from the rotation of the earth about its axis, and on the agency of elec- tricity. March 2. — 1. A paper was read, entitled, " On the laws of Indi- vidual Tides at Southampton and at Ipswich." By G. B. Airy, Esq., M.A., F.R.S., Astronomer Royal. The author gives the results of his own personal observations of the tides at Southampton and at Ipswich, in both of which places • See Phil. Mag., S. 3. vol.xx. p. 511.— Edit. Phil, Mag. S. 3. Vol. 23. No. 149. July 1843. E 50 Royal Society. they present some remarkable peculiarities. In conducting these in- quiries he obtained, through the favour of Colonel Colby, R.E., and Lieut. Yelland, R.E., the able assistance of non-commissioned officers and privates of the corps of Royal Sappers and Miners. He explains in detail the nature of his observations, and the method he pursued in constructing tables of mean results ; and deduces from them the conclusion, that the peculiarities in the tides which are the object of his investigation are not dependent on any variations in the state of the atmosphere, but are probably connected with the laws which regulate the course of waves proceeding along canals. 2. A paper was in part read, entitled, " On the Special Function of the Skin." By Robert Willis, M.D. Communicated by John Bos- tock, M.D., F.R.S. March 9. — 1. The reading of a paper, entitled, " On the Special Function of the Skin." By Robert Willis, M.D. Communicated by John Bostock, M.D., F.R.S., was resumed and concluded. The purpose which is answered in the animal economy by the cu- taneous exhalation has not hitherto been correctly assigned by phy- siologists : the author believes it to be simply the elimination from the system of a certain quantity of pure water, and he considers that the saline and other ingredients which pass off at the same time by the skin are in too inconsiderable a quantity to deserve being taken into account. He combats by the following arguments the prevailing opinion, that this function is specially designed to reduce or to regu- late the animal temperature. It has been clearly shown by the ex- periments of Delaroche and Berger, that the power which animals may possess of resisting the effects of a surrounding medium of high temperature is far inferior to that which has been commonly ascribed to them ; for in chambers heated to 120° or 130° Fahr., the tempe- rature of animals is soon raised to 11° or even 16° above what it had been previously, and death speedily ensues. The rapid diminution or even total suppression of the cutaneous exhalation, on the other hand, is by no means followed by a rise in the temperature of the body. In general dropsies, which are attended with a remarkable diminution of this secretion, an icy coldness usually pervades both the body and the limbs. A great fall in the animal temperature was found by Fourcauld, Becquerel and Breschet to be the effect of covering the body with a varnish impervious to perspiration ; and so serious was the general disturbance of the functions in these cir- cumstances, that death usually ensued in the course of three or four hours. The question will next arise, how does it happen that health and even life can be so immediately dependent as we find them to be on the elimination of so small a quantity of water as thirty-three ounces from the general surface of the body in the course of twenty-four hours ? To this the author answers, that such elimination is important as securing the conditions which are necessary for the enclosmotic trans- ference between arteries and veins of the fluids which minister to nutrition and vital endowment. It is admitted by physiologists that the blood, while still contained within its conducting channels, is Royal Society, 51 inert with reference to the body, no particle of which it can either nourish or vivify until that portion of it which has been denomina- ted the plasma has transuded from the vessels and arrived in imme- diate contact with the particle that is to be nourished and vivified : but no physiologist has yet pointed out the efficient cause of these tendencies of the plasma, first, to transude through the wall of its efferent vessels, and secondly, to find its way back again into the afferent conduits. The explanation given by the author is that, in consequence of the out-going current of blood circulating over the entire superficies of the body perpetually losing a quantity of water by the action of the sudoriparous glands, the blood in the returning channels has thereby become more dense and inspissated, and is brought into the condition for absorbing, by endosmosis, the fluid perpetually exuding from the arteries, which are constantly kept on the stretch by the injecting force of the heart. In an appendix to the paper, the author points out a few of the practical applications of which the above-mentioned theory is suscep- tible. Interference with the function of the skin, and principally through the agency of cold, he observes, is the admitted cause of the greater number of acute diseases to which mankind, in the tempe- rate regions of the globe, are subject. He who is said to have suf- fered a chill, has, in fact, suffered a derangement or suppression of the secreting action of his skin, a process which is altogether indis- pensable to the continuance of life ; and a disturbance of the general health follows as a necessary consequence. Animals exposed to the continued action of a hot dry atmosphere die from exhaustion ; but when subjected to the effects of a moist atmosphere of a temperature not higher than their own, they perish much more speedily ; being destroyed by the same cause as those which die from covering the body with an impervious glaze ; for, in both cases, the conditions re- quired for the access of oxidized, and the removal of deoxidized plasma, are wanting, and life necessarily ceases. The atmosphere of unhealthy tropical climates differs but little from a vapour-bath at a temperature of between 80° and 90° Fahr.; and the dew-point in those countries, as for example on the western coast of Africa, never ranges lower than three or four" degrees, nay, is sometimes only a single degree, below the temperature of the air. Placed in an atmo- sphere so nearly saturated with water, and of such a temperature, man is on the verge of conditions that are incompatible with his ex- istence : conditions which may easily be induced by exposure to fa- tigue in a humid atmosphere under a burning sun, of other causes which excite the skin while they prevent the exercise of its natural function. The terms Miasma and Malaria may, according to the author, be regarded as almost synonymous with air at the tempera* ture of from 75° to 85° Fahr., and nearly saturated with moisture. 2. A paper was also read, entitled, " On the Cause of the reduction of Metals from solutions of their salts by the Voltaic circuit." By Alfred Smee, Esq., F.R.S., Surgeon to the Bank of England. The reduction of a metal from its saline solution by the agency of voltaic electricity, has, the author states, been explained in three E2 52 * Royal Society. different ways. By Hisinger, by Berzelius, and by Faraday it has been ascribed to the liberation of hydrogen in this process : Davy and others considered it as resulting directly from the attraction of the metal to the negative pole : and Daniell conceives that the metal [so- lution?] is directly electrolysed by the action of the voltaic circuit. The author found that the ends of copper wires, placed in a solution of sulphate of copper between two platina poles in the circuit, mani- fest electric polarity ; so that while one end is dissolving, the other is receiving deposits of copper : he also found that platina was, in like manner, susceptible of polarity, although in a much less degree than copper, when placed in similar circumstances. With a view to determine the influence of nascent hydrogen in the voltaic reduc- tion of metals, he impregnated pieces of coke and of porous char- coal with hydrogen, by placing them, while in contact with a metal, in an acid solution, when they thus constituted the negative pole of the circuit ; and he found that the pieces thus charged readily re- duced the metals of solutions into which they were immersed ; and thence infers that the hydrogen is the agent in these reductions. From another set of experiments he concludes, that during these de- compositions, water is really formed at the negative pole ; a circum- stance which he conceives is the chief source of the difficulties ex- perienced in electro-metallurgic operations when they are conducted on a large scale, but which may be avoided by a particular mode of arranging the elements of the circuit so as to ensure the uniform diffusion of the salt. The author obtained the immediate reduction of gold, platina, palladium, copper, silver and tin from their solutions by the agency of hydrogen contained in a tube, with a piece of platinized platina in contact with the metallic salt : nitric acid and persalts of iron, on the other hand, yielded their oxygen by the influence of the same agent. The general conclusion which he deduces from his experiments is that, when a metallic solution is subjected to voltaic action, water is decomposed, its oxygen passing in one direction, and its hydrogen in the opposite direction ; the latter element performing at the moment of its evolution at the negative pole the same part with respect to a solution of sulphate of copper, that a plate of iron or zinc would per- form to the same solution. March 16. — The following papers were read, viz. — 1. " On the import and office of the Lymphatic Vessels." By Robert Willis, M.D. Communicated by John Bostock, M.D., F.R.S. That absorption is the special office of the lymphatic vessels was, until very lately, a universally received doctrine in physiology : but it is now admitted that if they exercise this faculty, it can be only to an inconsiderable extent ; and physiologists of high authority have even denied that they possess any absorbing power at all. This last is the opinion of Magendie, in which the author concurs. So lately as 184-1, Rudolph Wagner asserted that "neither anatomical nor physiological considerations render any satisfactory account of the import and office of the lymphatics," which thus, shorn of their ancient office, were repudiated as a superfluous apparatus in the Royal Society. 53 animal mechanism. The grand organs of absorption the author believes to be the veins ; and a principal object of his paper is to point out the mode in which they acquire this remarkable faculty. The principal condition which this faculty of imbibition implies, is a difference in density between the contents of the vessels which are to absorb, and the contents of those which furnish the matter to be absorbed. If the several constituent materials of the body, both fluid and solid, were to remain in the same unaltered state, both chemi- cally and physically, there could be no interchange among them : in order that mutual penetration may take place between two ele- ments, the one must differ from the other : that which is designed to absorb must be, with relation to that which is to be absorbed, more dense ; that is, must contain a smaller quantity of water in proportion to its solid ingredients. For the continuance of the de- licate processes concerned in the access and removal of the nutrient fluids, it is necessary that a difference should be established be- tween the arterial and the venous blood in respect of density. This purpose the author conceives is accomplished by the abstraction from the former of a portion of its water by the sudoriparous glands of the skin on the one hand, and by the lymphatic vessels on the other. That the separation of the lymph from the blood is calculated to increase its density, is proved by its chemical analysis ; lymph con- taining from 96 to 97 per cent, of water, and blood from 77 to 82 per cent. The author regards this separation of lymph from the blood as the result of a purely vital process of the same nature as that by which the saliva and the watery portion of the urine are secreted from the circulating mass. He considers that his views are supported by the anatomical distribution of the lymphatic system : for, on the principle that organs are found in the vicinity of the places whei-e their office is wanted, the office[of the lymphatics must be general, inasmuch as the system is general. These vessels may, in fact, be regarded as the essential element of an universally dis- tributed gland. The mode in which the lymphatics are finally con- nected with the blood-vessels appears also to indicate that the object in view is to keep their watery fluid separate from the blood as long as possible ; for, as is well known, they do not transfer their contents into the neighbouring veins, but pour their whole fluid into the superior vena cava at the moment it is about to enter into the heart. The remarkable manner in which the lymphatic system is de- veloped in some of the lower tribes of animals, whose bodies are en- cased in an impervious horny covering, such as turtles, lizards and serpents, is adduced in further corroboration of the author's views. He regards the serous membranes as contrivances for the accom- modation of a great number of lymphatics ; and the intimate con- nexion which the function of these vessels has with the life and nutrition of internal organs he thinks is shown by the remarkable amount of disturbance consequent on inflammation, or other morbid condition of serous membranes. Finally, the author adverts to the influence which the difference of endosmotic capability engendered 54) Royal Society. by the abstraction of a certain amount of water in the course of the circulation, (first between the blood corpuscles and the plasma in which they swim, and then between the liquor sanguinis and the containing channels,) must have on the capillary circulation, which he conceives it is calculated to facilitate. 2. " Further Observations on the descending fluids of Plants, and more especially the Cambium." By George Rainey, Esq. Commu- nicated by P. M. Roget, M.D., Sec. R.S. The author relates an experiment in proof of the sap descending from the upper to the lower part of an exogenous tree, through vessels which are continuous from the leaves to the roots ; the course of these vessels being shown by the addition of a solution of iodide of potassium after they had taken up by absorption a quantity of a solution of acetate of lead. The fluids in these vessels are, he con- ceives, separated from the sap, which is ascending from the roots, only by the membrane of which they are composed. When the leaf-buds of a tree are vegetating, large separations are observable between the cells of the bark, and also between the bark and the wood ; while no such separations are apparent when the leaf-buds are entirely inactive. These separations are various in size, and irregular in form ; their parietes consist of rows of cells, piled up one above another, like the bricks of a wall : and their cavities all communicate with one another. From these and other anatomical facts, which are given in detail by the author, he concludes that the propulsion of the sap along the vessels, resulting from the opera- tion of endosmose, will explain the descent of the cambium, which, being the nutritious portion of the vegetable fluids, corresponds in its nature to the chyle in animals. March 23. — A paper was read, entitled, " Notice of an Extraor- dinary Luminous Appearance seen in the Heavens on the 17th of March, 1843," in a Letter to S. H. Christie, Esq., Sec. R.S., by Sir John F. W. Herschel, Bart., F.R.S. Collingwood, March 17, 1843. My Dear Sir, — This evening, at half-past seven o'clock, I received notice from one of my servants of a luminous appearance in the sky, visible towards the S.W., which I immediately ran out to ob- serve, and which, as it differed in some remarkable particulars from any phenomenon of the kind I have ever before observed or seen described, I think it not unlikely to prove interesting to the Royal Society. The evening was one of uncommon serenity and beauty: the moon, only thirty-eight hours after the full, having considerable south declination, was not yet risen. In consequence, the sun being already far enough below the horizon to leave only a faint glow of twilight in the west, the stars shone with unsubdued brilliancy, no cloud being visible in any quarter. Orion in particular was seen in all its splendour ; and commencing below that constellation, and stretch- ing obliquely westward and downwards, nearly, but not quite to the horizon, was seen the luminous appearance in question. Its general aspect was that of a perfectly straight, narrow band of con- Royal Society. 55 siderably bright white cloud, thirty degrees in length, and about a degree and a quarter, or a degree and a half in breadth in the mid- dle of its length ; its brightness nearly uniform, except towards the ends, where it faded gradually, so that to define its exact termination at either end was difficult. However, by the best judgement I could form, it might be considered as terminating, to the eastward or fol- lowing side, at, or a very little beyond, the stars t, k, X Leporis, which stars (being of the fifth, or at most 5*4 magnitude) were pretty con- spicuously visible ; from which circumstance the degree of bright- ness of the ground of the sky in that region may be well estimated.. Between these stars and fx Leporis, the luminous band then com- menced, involving neither of them, but more nearly contiguous to k and \ than to /i. From thence its course was towards rr Eridani, which star must have been covered by it, and was not seen ; this judgement of its direction having been formed by noticing that it passed clearly above y Eridani, and as clearly below and parallel to the direction of c, e Eridani, which two stars being dimmed by the vapours of the horizon and the twilight, were so little conspicuous as perfectly to account for ir not having been noticed. At the point of its pass- age between y and 5 it was still considerably bright, and as it ter- minated with somewhat more abruptness at a point beyond e (then about 1 2° high) than at its upper extremity, I am rather disposed to consider this end as somewhat curtailed by the vapours. Making no allowance, however, for this, and estimating its visible termina- tion at a point on a celestial globe nearly opposite £ Eridani (which star however was not noticed at the time), the length above assigned to the luminous band (30°) has been concluded by measurement on the globe. I am thus particular in describing the course, situation and di- mensions of the band, not only as terms of comparison with other observations of it, should any have been made, but for another rea- son, in which consists the peculiarity of the phenomenon, and which is my sole motive for making this communication. The above situ- ation and course, relatively to those stars, remained perfectly unal- tered the whole time it remained visible at all, which it did for up- wards of an. hour from the time I first saw it, accompanying the stars in their diurnal motion, until the preceding end at length was extin- guished in the horizon vapours with the stars adjacent, and until the light of the rising moon dimmed and at length effaced the rest, though I apprehend its intrinsic lustre to have been in progress of diminution during the last quarter of an hour or twenty minutes. I should not forget to mention, that neither in the north-west, nor elsewhere, were any streamers or other appearances of Aurora Borealis perceptible during any part of the evening. The only other luminous appearance, the milky way excepted, was that of the zodiacal light, which I have seldom seen to greater advantage in this climate, and which extended high enough to involve the Pleiades, then about 55° from the sun. I have said that the general aspect of the phenomenon was that of a bright white cloud. In fact, my first impression was that such 56 Boyal Society, was its nature ; an impression immediately dissipated and ultimately converted into the contrary certainty by the following considerations and observed facts. For, in the first place, no ordinary cloud at such an angular elevation above the horizon could have received from the sun, even at the earliest hour when it was observed, any- thing like sufficient illumination to have presented so luminous an appearance; that luminary being then between 9° and 10° below the horizon, and the moon not yet being risen, even at eight o'clock, when I judged the light of the band by contrast with the increasing darkness of the ground of the sky to have attained its maximum, at which hour the depression of the sun was nearly 12°. Moreover, 2ndly, about a quarter of an hour after the band was first observed, being then on the roof of my house and having a very uninterrupted view of the western horizon, I noticed the for- mation of a small streak of cloud about the same apparent altitude, somewhat to the north of the pyramid of the zodiacal light, and therefore nearer to the place of the sun below the horizon. The direction of this streak was horizontal, not oblique, and its hue black, not white. This cloud enlarged and became projected as a dark space within the zodiacal light, and soon after others of a less defined character formed elsewhere, all, however, without exception, dark instead of luminous. 3rdly. At the rising of the moon, about half-past eight, the light of our band, already probably on the decrease, was almost wholly effaced. On the other hand, by this time numerous lines and cirrous streaks of light cloud which had been for some time in progress of formation, and had been either wholly unseen before or only noticed by their effacing the stars behind them, became illu- minated, and appeared as white streaks and patches, such as are usually observed in moonlight nights. 4thly, and lastly. Although the night was very calm, yet on watching narrowly the motions and changes of these real clouds with respect to the stars, they were perceived to rise very slowly from, the west, i. e. in a direction nearly or quite contrary to that of the declining band. From these united considerations, and from the extreme fixity of the band among the stars, I consider it impossible to regard it as a cloud illuminated by the sun through the medium of atmospheric refraction. The latter reason, too, is equally conclusive against its being classed with ordinary auroral bands and arcs, which, though they keep their position well enough to be regarded as at rest by a careless observer, yet, when compared with stars, are always per- ceived to be drifting, as it were, in some certain direction, or other- wise changing in figure and dimension. If we look to an origin for this phenomenon beyond our atmo- sphere, we become involved in speculations, which, however inter- esting, it is not the object of this communication to enter into. On the other hand, its purpose will be answered if either it should be the occasion of eliciting corresponding observations of the same, or notices of similar phaenomena already observed, or should lead Geological Society, 57 to increased watchfulness on the part of meteorologists to avail themselves of occasions (which perhaps occur oftener than we are aware) of noting anything analogous in future. I have the honour to remain, My dear Sir, Your very faithful and obedient Servant, J. F. W. Herschel. Saturday, March 18, 1843. P.S. — There having been no post today, and the above not having been finished in time for despatch last night, an opportunity is af- forded me for stating that the phaenomenon abovedescribed has again reappeared this evening, at the same hour and in the same situation, or rather a very little more to the north, so as to graze and partly to involve the stars *-, \ Leporis. It was also traceable in R. A. some little way beyond those stars on the following side. The horizon being more obscured by vapour tonight than last night, neither y, 3, nor e Eridani could be seen. The fixity of this object among the stars on the 17th, induced me to express to a member of my family this morning an idea that it might possibly be seen again tonight, in which event its extra-at- mospheric origin would become quite evident. If a thread be stretched on a celestial globe along the central line of the band as nearly as the above observations will enable us to fix it, and pro- longed to meet the ecliptic, it will strike on the actual place of tJie sun. The inference seems almost unavoidable, that our band is no other than the tail of a magnificent comet, whose head at the times of both observations has been below the horizon*. I await, there- fore, with extreme interest, the event of further observation, but al- though to afford others an opportunity of observing it, it will be neces- sary for me to make a more immediate and public announcement, I am still desirous to place on record my first impressions respecting so remarkable an appearance, in the mode originally intended, both as a mark of respect to the Royal Society, and as pointing inquiry to other luminous " streaks " and " columns " in the sky, which have been spoken of to me as having been seen during the last summer and autumn on more than one occasion, and which in point of fact caused me to desire every inmate of my family to give me imme- diate notice of the appearance of anything unusual in the heavens, and thus led directly to the observations above detailed. A paper was also in part read, entitled, " Researches into the Structure and Developement of a newly discovered parasitic Ani- malcule of the Human Skin, the Entozoon folliculorum" By Eras- mus Wilson, Esq. Communicated by R. B. Todd, M.D., F.R.S. GEOLOGICAL SOCIETY. [Continued from vol. xxii. p. 228.] April 6, 1842.— -A Memoir, entitled "A Second Geological Sur- vey of Russia in Europe," by Roderick Impey Murchison, Esq., * See Phil. Mag., S. 3. vol. xxii. p. 323.— Edit. 58 Geological Society. Mr. Murchison's Pres. G.S., F.R.S., M. E. de Verneuil, Member of the Geological Society of France, and Count Keyserling, was also commenced. April 20. — The reading of the Memoir on Russia commenced on the 6th of April was resumed and concluded. With the exception of a sketch of the Ural Mountains, to be given in a subsequent memoir, and of two short notices previously read, on the Freezing Cave of Illetzkaya Zatchita, and on the " Tchornoi Zem," or Black Earth*, the following abstract contains the chief results of a second examination of Russia in Europe. Following the same method as in the account of their first ex- amination, the authors describe the depositary strata in ascending order, successively adding to or correcting their previous know- ledge of each mass of deposits. Silurian Rocks. — The boundaries of these the most ancient fossil- iferous strata are more correctly defined than last year, and new localities are cited. The lowest subdivisions of blue shale and un- gulite grit, which were previously spoken of in certain inland spots only, are now described in the sea-cliffs of the Baltic between Reval and Narva, as well as on the banks of the rivers Narva and Luga, in which situations, as in the tracts S. and S.E. of St. Peters- burgh, they constitute the inferior masses or representatives of the Lower Silurian Rocks. The Upper Silurian Rocks, chiefly composed of thin-bedded lime- stone, occupy the summits of the coast-cliffs in question, and the platform on which the river Narva flows from the lake Peicpus to a chasm worn by its own action, where it constitutes the picturesque falls above the Castle of Narva. It is believed by the authors that this water-fall has receded (like those of Niagara, in America, and other places,) in consequence of a solid tabular rock overlying less coherent strata, which have been undermined and have occasioned the subsidence of the superior layers. In addition, however, to these conditions, the wearing away of the vertical cliffs of the Baltic and the retrocession of the falls of the Narva, are supposed, by the authors, to have been accelerated by another cause, viz. the direc- tion of the symmetrical joints in the overlying limestone. These joints present a number of salient and re-entering angles which are exposed on the surface of the impending cliffs, and when the softer supporting strata have been partially excavated, the dividing lines of these natural joints facilitate the fall of the calcareous beds into the abyss below. Besides the chief masses of limestone which extend over a con- siderable tract in the province of Esthonia, (including the Isles of Oesel and Dago,) the authors advert to a separate tract near the small town of Schavli, in the government of Wilna, occupied by upper Silurian rocks, which they discovered in their journey to St. Petersburgh, and which they place as the highest member of the system, or above the principal masses of the Orthoceratite and Tri- lobite limestone and beneath the overlying old red or Devonian * See Proceedings of Geol. Soc. of London, vol. iii. pp. 712-714 ; [or Phil. Mag. S. 3. vol. xxi. p. 357 j and vol. xxii. p. 71.— -Edit.] Second Geological Survey o/Bussia in Europe. 59 formation. In this limestone fifteen species of fossils were observed, including Pentameri, Terebratulce, and Orthidce ; and it is considered to be the representative of a calcareous rock which ranges to the north of Dorpat and Weissenstein, and is known at Oberpahlen, &c. Notwithstanding their almost perfectly horizontal position, the strata in the Baltic provinces of Russia indicate most clearly a passage from a lower horizon on the north to a higher on the south, where they are surmounted by the Devonian system. In announcing a large accession of Silurian fossils to their former lists, the authors advert to the labours of Professor Eichwald, who after a personal examination of the coast-cliffs and of the Isle of Dago, has been sedulously occupied in describing many new species. They also dwell upon the important addition to their knowledge of new forms contributed by Dr. Worth, the secretary of the Imperial Academy of Mineralogy, — forms which they purpose to figure and describe in the course of the ensuing winter; and they acknowledge their obligations to Colonel Helmersen and the officers of the School of Mines, for aiding them in their acquisition of fresh knowledge concerning the contents of these the most ancient de- posits of* the Russian empire. In their tabular list of fossils the authors give the following as characteristic of, and in part peculiar to, the Silurian rocks of Russia : — Asaphus expansus (Dalm.*), A. cornutus, Illcenus crassicauda (Dalm.*), Amphyx nasutus (Dalm.*), Orthoceratites vaginatus (Schloth. -j-), Lituites convolvens (Schloth.f ), Clymenia Odini (Eichw.J), Terebratula Wilsoni I (Sow. in Sil. Syst.), T. sphcera (Von Buch$), T. camelina (Von Buch§), Orthis anomala (Terebrat. Schloth.f), O. Uralensis\n.a., O.Panderi,n.s., O.cincta (Eichw.J), Leptana imbrex (Pand.,), Lepteena rugosa (Dalm.||), Spirifer bifo- ratus (Terebrat. id. Schloth.), Geological Society : Mr. Murchison's beds being stated in all cases to be subordinate to the mountain limestone series, whilst certain overlying shales, sandstones, &c, which were observed in one corner of the district, contain few or no traces of coal. At the western extremity of this region, the coal-bearing strata thin out into sandy masses, which repose unconformably on certain highly inclined quartzose, gneiss and granitic rocks, that appear on the banks of the river Voltchia, and extend to the Dnieper and the cataracts of that river near Ekaterinoslaf. To the south-west, near Karakuba and towards Mariopol, in a tract occupied by Greek colo- nies, similar primary rocks appear, penetrated both by granite and porphyry, whilst to the south-east and north the whole carbonaceous region is overlapped partially by red sandstone with gypsum, as near Bachmuth, but more generally by cretaceous and tertiary rocks. The former, in the state of white chalk, occurs in a large zone in the north, and in a smaller band at the southern limits of the coal tract. The dislocations and upheaval of the subjacent rocks extend to some distance to the north of the chief carbonaceous masses ; for at Petrofskaya, considerably to the north of the nearest outcrop of the chief coal-field, coal with carboniferous limestone is upcast to the surface in highly inclined positions, surrounded by nearly horizontal strata of the Jurassic and cretaceous epochs, and generally so ob- scured by drift and clay, that it is well seen in one ravine only. Coal, however, has been detected at adjacent places in sinking for water. The uppermost members of the carboniferous system are not observable in the North of Russia, or in the Moscow basin, where Jurassic strata repose at once upon true carboniferous limestone ; but in the southern coal-tract, just alluded to, there are, as before said, beds of shale and sand which overlie this limestone series, and yet are unproductive of coal (north of Gorodofka). On the western flanks of the Ural mountains, however, as will be shown in the next memoir, to the east of Perm, and at Artinsk, are sandstones and conglomerates with plants passing occasionally into calcareous grits with Goniatites, which, as seen on the banks of the Tchussovaya and near Artinsk, are superior to the great carboniferous limestone. Very thin courses of coal only are observed at intervals in this upper member of the system, and the Goniatites which it contains belong, as a whole, to that division of the family which characterizes the uppermost member of the carboniferous limestone and certain coal- fields (Coalbrook Dale) of Western Europe. There is a consider- able development of this subdivision on the flanks of the Guber- linski hills, and partially on the. south-western edges of the Ural east of Orenburg. Permian System. (Zechstein of Germany — Magnesian limestone of England.) — Some introductory remarks explain why the authors have ventured to use a new name in reference to a group of rocks which, as a whole, they consider to be on the parallel of the Zechstein of Germany and magnesian limestone of England*. They * " I have recently been informed by M. A.. Erman, that an erroneous Second Geological Survey of Russia in Europe. 65 do so, not merely because a portion of the deposits in question lias long been known by the name " grits of Perm," but because, being enormously developed in the governments of Perm and Orenburg, they there assume a great variety of lithological features, and con- tain the bones of thecodont Saurians and certain fishes, also a more copious fauna and flora than have ever been observed in their equi- valents in Western Europe. The Permian rocks of Russia which occupy so vast a region to the east of the river Volga, i.e. in the governments of Kasan, Viatka, Perm and Orenburg, are composed of white limestone with gypsum, red and green grits with shales and copper ores, magnesian lime- stones, marl-stones, small conglomerates, red and green sandstones, &c. By examining numerous natural sections between the neigh- bourhood of Sviask, Kasan, and Samara, upon the west, and the carboniferous limestone on the edge of the Ural mountains on the east, the authors have come to the conclusion, that however the lithological sequence may vary in different tracts, the whole of the vast region alluded to is occupied by deposits which belong to one class or zoological system of deposits. Thus, though the limestones are sometimes white, sometimes yellow and pure magnesian, and oftentimes pass into marl and marlstone, all of which can be observed to inosculate with strata of red sandstone, conglomerate, &c, the same fauna pervades the whole group. The Mollusca and Polypi- fers are clearly of a type intermediate between those of the carboni- ferous limestone and those of the Trias or new red sandstone group of Continental geologists. Among the most characteristic of these fossils may be enumerated Productus horrescens, n.s., P. Cancrini, n.s., Spirifer lamellosus (L'Ev.), Terebratula elongata (Schloth.), T. Roysii (L'Ev.) (T. Roysii, L'Ev. = Atrypa pectinifera, Sow. Min. Conch. No. 107), Natica variata (Phil.), Modiola Pallasii, n.s., Gervillia lunulata (Phil.), Ostrcea matercula, n.s., Corbula Rossica, n.s., Avicula Kasaniensis, n.s., A. antiqua (Schloth.), A. cheratophaga (Schloth.), Lingula parallela (Phil.), Limulus oculatus (Kutorga), Cytherina ; with Reteporajlustracea, Gorgonia,Millepora, &c. &c. In the conglomerates and sandstones, fishes have been found, some of which belong to the genus Palseoniscus, so characteristic of the Zechstein and magnesian limestones ; and the Saurian bones, portions of which have been figured by M. Kutorga, and more per- fect remains of which have been described by Professor Fischer von view has been communicated in my anniversary discourse, respecting the first use of the word ' Zechstein ' in reference to the deposits of Perm, that term having been used, as he assures me, by German viiners, who visited Russia long ago, though no proofs have been since offered to sustain its ap- plication in a geological sense. I also take this opportunity to state, that through a misapprehension of his views, derived from a perusal of the Bul- letin de la Societe" Geologique de France, I have been led into a mistake in supposing that M. Erman believed a large portion of the Russian rocks, now shown to be carboniferous, to belong to the Jurassic epoch. I willingly adopt this correction of my views in reference to the distinguished modern explorer of Siberia and Kamschatka." — R. I. M., Sept. 1842. Phil. Mag. S. 3. Vol. 23. No. 149. My 1843. F 66 Geological Society. Mr. Murchison's Waldheim (Rhopalodon Mantellii, Fisch.), have been pronouneed by Professor Owen to belong to the class of thecodont Saurians of that author (See Report on Saurians to the British Association, 1841, p. 153). Certain plants of this great deposit have been figured by M. Ku- torga, and referred by him to the carboniferous epoch ; others col- lected by Major Wangenheim Von Qualen have been named by M. Fischer de Waldheim, who, as well as their discoverer, felt great dif- ficulty in forming any decisive opinion respecting the age of the strata in which these fossils occur. Having examined the localities and sections, the authors convinced themselves on the spot, that all these plants are of intermediate character between those of the carboniferous and triassic seras*. These vegetables of the Permian system, and many undescribed species of shells with which they are associated, will be figured in a forthcoming work on the geology of Russia, and for this purpose M. Fischer has kindly contributed some beautiful drawings of new genera and species which he had prepared at Moscow. The publication of these new species will show that the epoch of the Zechstein was characterized by a flora peculiar to it. These fossil plants, although generally appearing to constitute an inde- pendent flora, offer some analogies in form to a few species belong- ing to the carboniferous series : one species cannot easily be distin- guished from the coal-measure plant, Cal. Suckovoii, which Bron- gniart considers to be very variable in form and to have a great geographical range. Among the characteristic forms may be men- tioned the Catamites gigas, Neuropteris Wangenheimii, N. salicifolia, Odontopteris Strogonovii, Sphenopteris erosa, Noeggerathia undulata, and some other species to be described. These plants are sometimes accompanied by thin courses of coal and lignite, which near Perm have some of the external characters of poor coal-fields. But while the carbonaceous appearances are evanescent and local, the fossil stems and leaves are very general indicators of the presence of copper ore, which, in the form of gray oxide and green carbonate, is often copiously disseminated through the vegetable matter, or arranged around the thicker branches in masses, from which it extends in fine filaments into the adjacent sands ormarls. In all cases, the copper ores of this region occur in laminae, inosculating with the other regular strata, in which respect they differ essentially from the chief copper ores of other countries. They are, in fact, regenerated ores, formed, it is conceived, by cupriferous streams and currents that flowed from the adjacent Ural moun- tains, which, it will be shown, were, during very early periods, the site of great copper veins f. As a solution of copper which was let loose by accident in modern * Mr. Morris, who has undertaken the description of the new species of these plants, completely confirms the views of the authors. (See letter of Mr. Murchison, dated Moscow, October, 1841. Phil. Mag. S. 3. vol. xix. p. 418.) ■f Among the mineral analogies between the Permian rocks and those of Second Geological Survey of Russia in Europe. 67 times upon an adjacent peat bog in North Wales specially affected and impregnated the vegetable fibre in preference to the accom- panying soil, so is it conceived that the forests washed into the sea in which the Permian deposits were accumulated, attracted around them the cupriferous matter contained in the transporting currents. This point will be reverted to in the subsequent sketch of the Ural mountains. The general succession of these Permian deposits is then described on several parallels of latitude between the Ural and the Volga, and also their outliers in the steppe between Orenburg and Sarepta ; and it is shown, that this vastly extended and diversified system, containing not only copper deposits but also large masses of gyp- sum, rock-salt and copious salt-springs, lies in an enormous trough bounded on the north and east, and south-west, by the carbonife- rous limestone on which it reposes. By their examination during the past year, the authors have cleared away some difficulties which obscured their former views. By reference to the abstract of their first memoir (vol. xix. p. 492), it will be seen, that they considered (though with much hesitation) certain limestones and beds of gypsum which occupy cliffs upon the Dwina to the south of Archangel, and extend to Pinega and to- wards Ust Vaga, to be upper members of the carboniferous lime- stone. By a comparison of the Producti and other fossils, and the great masses of gypsum which they contain, these northern beds are now brought into direct identification with the true Per- mian or Zechstein deposits. In the south-western termination of this vast basin near Samara, the Permian rocks, particularly at Usolie, rest in patches of a dolomitic conglomerate upon the steep escarpments of the carboniferous limestone, out of the mate- rials of which they have been formed, and do not present that regular succession which they exhibit when followed westwards from the slopes .of the Ural chain. It is also observed, that though gently undulating or horizontal over all the lower regions, these rocks, on approaching the Ural mountains, are occasionally thrown into anticlinal axes of some length, parallel to the direction of the palaeozoic rocks of the adjacent chain. In a sketch of the outliers in the Steppe of the Kirghiss, the base of the insulated hill of Monte Bogdo is shown to consist of a mem- ber of the Permian group, surmounted by fossiliferous limestone which probably belongs to the Jurassic system ; and it has before been shown that the rock-salt of Iltetzkaya Zatchita*, south of the magnesian limestone it appears, from Professor Sedgwick's description of the latter, that traces of lead ore and also of copper, are found in it in small quantities, which that author considers to have been derived from the large mineral masses of the same in the surrounding and more ancient car- boniferous limestones. Lead is also worked in the dolomitic conglomerate of the Mendip Hills, where it is associated with calamine. See memoir of Mr. Conybeare and Dr. Buckland, Geol. Trans., 2nd Series, vol. i. part 2. p. 293 ; also Mr. Weaver's memoir, ibid. p. 367. * Proceedings, vol. iii. p. 695, [or Phil. Mag. S. 3. vol. xxi. p. 357.1 F2 68 Geological Society : Mr. Murchison's Orenburg, is subordinate to this system, in which indeed the great- est saline springs of Russia occur. Red Sandstone, Marl, 8$c. — It is with hesitation that the authors make any separation between the Permian deposits and certain red and green sandstones, marls, marlstones and tufaceous lime- stones, which occupy the central parts of the great trough above described ; still less can they strictly identify them with the bunter sandstein, new red or trias of West Europe. It is however a fact, that the Permian rocks with their peculiar fossils are seen near Sviask, on the west of Cazan, to pass under red and green marls and impure limestones, which extend over a wide region by Nijny Novogorod, Juriavetz and Viasniki on the west, and to Totma and Ustiug on the north. In no part of the region so defined (and most of which the authors examined on a previous occasion), have any fossils typical of the Permian age been discovered, though the deposits in question abound in limestones generally of a tufaceous character. The gypsum which occurs in this member, differs from the massive white alabaster of the inferior rocks, and is usually in the form of small concretions of fibrous structure, often of brownish and pinkish colours. At only Vias- niki on the Kliasma could the authors detect any traces of fos- sils, and these are minute Cypridee, associated with apparently flat- tened Cyclades ? which are imbedded in blood-red marl. The thick cover of detritus which is spread over a very large area, ob- scures the junction of these red deposits with the eastern edges of the carboniferous limestone of the Moscow and northern regions. Whatever may be the precise age of the uppermost beds of these red deposits in reference to other strata in Europe, it is clear that a considerable portion of the full geological succession is wanting in Russia, for in various points upon the Volga, Jurassic shales are seen to repose on the denuded surface of these red deposits. Jurassic System. — In the sketch resulting from their survey in 1840 (vol. xix. p. 495), Mr. Murchison and M. de Verneuil were dis- posed to view certain deposits of shale and sand with concretions, which in some places overlie the last-mentioned red deposits, and in others rest at once on the carboniferous limestone, as the equiva- lents of the lias and lower oolites. This opinion is now modified, a more extensive survey having led to the belief that true lias does not exist in Russia ; but that the shale beds in question, whether studied in sections on the Moskwa near Moscow, on the Volga be- tween Kostroma and Jurievetz, or at numerous localities in the go- vernments of Simbirsk, Saratofand Tambof,are truly theequivalents of the strata from the inferior oolite to the Kimmeridge clay, in- clusive, of English geologists. It is this Jurassic group which is traceable at intervals so far to the north-east, and which has been found by Capt. Strajesski as far as even 65° N. lat. on the eastern flanks of the Ural chain. The upper members of the Jurassic system, as exhibited in the South of Russia, near Izium, where they were first recognised by Major Blode, differ both lithologically and zoologically from the Second Geological Survey of Russia in Europe. 69 dark shales and sands of the northern and central regions. They are chiefly light-coloured limestones and marls, and are charged with large Ammonites resembling those of the Portland rock with Trigonia clavellata, Nerinea, and other types closely allied to those which occur in the upper oolites of Great Britain and the Continent. Cretaceous System. — This system is very considerably developed in the central and southern tracts of Russia. In the government of Simbirsk, where it has been closely studied and its fossils carefully collected by M. Jasikof, it surmounts the Jurassic series, and the same order may be seen in the governments of Saratof and on the banks of the Donetz near Izium. Though the lithological sequence of the strata differs from that of the British Isles, the system, as a whole, bears striking analogies to that of the same age in Western Europe. The white chalk, for example, and many of the fossils which it contains, including Ino- ceramus Cuvieri, Belemnites mucronatus, and Gryphcea vesiculosa, is absolutely undistinguishable from that of France and England; but in the localities seen by the authors, it did not offer the same sub- jacent succession of gault and lower greensand as in Western Europe, though at Kursk the white chalk reposes on hard concre- tionary sandy ironstone, somewhat resembling the clinkers of the lower greensand of England. Nor are there any evidences of the existence beneath the cretaceous rocks of the " Systeme Neoco- mien " of the French geologists. Associated however with the white chalk, the authors observed, particularly between Saratof and Tzaritzin, many beds of marl and siliceous clay-stone, in which bodies like Alcyoniee were prevalent, and at Kursk they found that the white and yellowish subcalcareous marls which closely overlaid the white chalk contained a Belemnite, as well as certain polypifers common to the true white chalk of other parts of Russia (Volsk), and hence they concluded, that some of these overlying marls are possibly the representatives of the Maestricht beds of Europe. The white chalk alone has been pierced to a depth of upwards of 600 feet by an artesian shaft at the iron forges of Lugan, in South- ern Russia, in which tract the deposit lies unconformably on the uplifted edges of the carboniferous rocks. Tertiary Deposits. — The tertiary strata, as separated from diluvial and alluvial accumulations, are little known in the North of Russia, with the exception of the shelly strata of post-pliocene age which have been described in the government of Archangel, vol. six. p. 495. The lowest tertiary beds which the authors personally examined, are the marls with concretions forming clifts at Antipofka, on the right bank of the Volga below Saratof, where they were first noticed by Pallas. Among these shells are several species undistinguishable from those published by Sowerby from the London clay of Bognor and Hants, such as Cucullcea decussata, Venericardia planicosta, Calyptrcea trockiformis, Crassatella sulcata, Turritella edita, &c. The middle tertiary or miocene strata are spread, it is well known, over large tracts in Volhynia and Podolia, in which countries they have been described or alluded to by Prof. Eichwald, M. Dubois de 70 Geological Society. Montperoux, Major Blode, and others. Distinctions are, however, drawn between the more ancient tertiary strata, such as those of Antipofka and other places, and the recent Caspian shelly sands which cover the Steppes, the former having constituted a portion of the ancient shores of a more widely spread Caspian sea. The au- thors also entirely discard from residuary phaenomena due to the presence and retirement of these Caspian waters, the existence of certain great subterranean masses of rock-salt and salt-springs which issue from the bowels of the earth, both of which have their seat in purely marine deposits of much higher antiquity, chiefly Permian, and which can never be referred to the desiccation of comparatively modern, brackish, inland seas. The pliocene and post-pliocene strata, occupy a very large region in Southern Russia. The inferior division of this group is well ex- posed in the lowest part of the cliffs at Taganrog, on the sea of Azof, where beds of white and yellow limestone contain several species of Cardium, a Buccinum and large Mactrse, all of marine origin. The superior members, often reposing on sands and siliceous grits, con- stitute the widely spread " Steppe limestone," in which are many remains of Mollusca that must have lived in brackish seas. These beds, as seen at Novo Tcherkask, the capital of the Don Cossacks, and adjacent places, are considered to be the extension of similar shelly deposits in the Crimaea and the neighbourhood of Odessa, described by M. deVerneuil (See Trans. Geol. Soc. of France, vol. iii.p. 1.). The vast flat steppes of Astrachan traversed by Count Keyserling, who rejoined his companions at Sarepta, are proved, as suggested by Pallas, to have been the abode of the adjacent Caspian Sea at a comparatively modern period ; and in confirmation of this view, it is stated, that not only the low country is covered with shells, but that the cliffs at Monte Bogdo, which rise out above this steppe, are also corroded to a certain height in the same way as sandstones of simi- lar nature are affected by the surge of the present seas. Superficial Detritus, Bones of Extinct Mammalia, Northern Boul- ders, fyc. — It is shown that the mammoth alluvia are analogous to those of other countries in indicating, over large areas, a period when elephants, rhinoceroses and other gigantic animals of species now extinct, inhabited the surface of the earth not far from the spots where they are now interred, their bones, as demonstrated by their condition as well as by the matrix in which they lie, not having un- dergone distant transport. This subject will be again considered in a sketch of the Ural mountains, but in the mean time, lists of the animals, some of them peculiar to Russia, which are preserved in the museums of Moscow and St. Petersburgh, were given. Lastly, new data are offered in respect to the southernmost limit of the northern blocks described on a previous occasion (vol. xix. p. 496), and their further advance to the south in some situations than in others, is attributed to the form of the present con- tinent of Russia in Europe, nearly all of which, it is presumed, was under the sea during the distribution of these boulders. Chemical Society. 71 The authors adhere to the opinion previously expressed by them, that such blocks were transported to their present positions by huge floating icebergs, arrested, in some instances, by rising grounds and hills at the bottom of the then sea, and in others permitted to ad- vance further south by longitudinal depressions, which are traceable in the present configuration of the land. Proofs are given that in many instances blocks of trap and quartz rock advance to quite as southerly latitudes as those of granite, and that all these blocks can be traced back to their parent rocks in Russian Lapland and the northern parts of Russia in a north-north-westerly direction, the currents by which they were transported having therefore been di- rected to the south-south-east. The black earth or Tchornoi Zem, which forms the highest deposit of the central and southern regions of the empire, has been described in a previous memoir (See ante, vol. xxii. p. 71). A large geological map of Russia in Europe, coloured by the authors, and numerous sections and collections of fossils, illustrated this communication, and it was announced that other conclusions respecting the structure of Russia would follow the description of the Ural Mountains*. CHEMICAL SOCIETY. (Continued from vol. xxii. p. 323.) March 7, 1843. — The following communications were read: — 71. " On the Astringent Substances " (continued), by John S ten- house, Ph. D.t 72. " On ^Ethogen and the ^Ethonides," by William H. Bal- main, Esq. On the 6th of December, 1842, I communicated to the Society the discovery of a new compound of nitrogen and boron which was named " JEthogen," and which, like cyanogen, combined with the metals J. At that time hopes were held out that I should be able to furnish the Society with an analysis of sethogen and the results of further experiments, but I am still without the means of doing the former, and have been prevented by illness from working much at the latter. However, some experiments which I have been able to make have brought out very easy processes for preparing sethogen and the sethonides, which may be interesting to chemists, and will place at their disposal a ready means of obtaining these very stable compounds which may prove powerful agents. ./Ethogen was originally obtained by heating together a mixture of boracic acid and melon, and the principal difficulty attendant upon the process was the previous preparation of the melon. An attempt * On the Geology of Russia, see also Mr. Murchison's recent Address to the Geological Society, inserted in our Supplement to vol. xxii. pub- lished with the present Number. — Edit. T This paper, together with all those read before the Chemical Society, of which abstracts do not appear in these Proceedings, or which are not otherwise referred to, will be given entire in future Numbers of the Philo- sophical Magazine. — Edit. t Mr. Balmain's former communication was given in our last volume, p. 467.— Edit. 72 Chemical Society. having been made to form melon by heating together bicyanide of mercury and sulphur, it appeared that melon was formed, but was with difficulty separated from the sulphuret of mercury which accom- panied it ; but as the presence of the sulphuret of mercury does not interfere with the formation of aethogen from a mixture of melon and boracic acid, that substance may be obtained by simply heat- ing together 5 parts of sulphur, 58 of bicyanide of mercury and 7 of anhydrous boracic acid, or by heating together sulphocyano- gen and boracic acid. Having an easy process for preparing aetho- gen, it was advisable in the next place to have a more ready method of forming the aethonides than that of heating together aethogen and the metals, which is a long and uncertain process, and an attempt was made to form aethonides by heating aethogen with the sulphurets of the metals. As might be expected from the stability of aethogen and its strong affinity for the metals, the aethogen directly displaced the sulphur and formed the aethonide. Upon further experiment it was proved that the aethonides might be made by heating sulphur, bicyanide of mercury and boracic acid with the metallic sulphurets. The proportions should be such as would give rise to the presence of 2 atoms of the metallic sulphuret, 2 atoms of boracic acid (sup- posing its composition to be B03), 3 atoms of cyanogen, and 3 atoms of free sulphur. The aethonides when thus formed are not quite pure, but may be readily purified by boiling with a mixture of nitric and muriatic acids and afterwards washing carefully. In this way aethonides of sodium, iron, copper and lead have been formed. Common galena was used for the aethonide of lead ; and for that of iron, iron filings and an ad- ditional quantity of sulphur. These four aethonides are all perfectly white and infusible ; before the blowpipe they yield the very beauti- ful phosphorescent light alluded to in a previous communication, and in all respects resemble the aethonides of potassium, zinc, lead and silver which were described as being made by the other processes. In conclusion, I beg to draw the attention of the Society to the remarkable stability of these compounds and the very strong affini- ties of aethogen. ^Ethogen attracts moisture from the air with great avidity, and decomposes it so rapidly, that a portion of aethogen which I have kept in a moderately well-stoppered bottle smells strongly of ammonia. The want of means must still be my apology for not furnishing the Society with a quantitative analysis, but if any member of the Society will undertake one, I shall be most happy to supply him with a fair specimen of aethogen. 73. " On the Exhalation of Carbonic Acid from the Human Body," by E. A. Scharling, Professor of Chemistry in the University and Polytechnic School of Copenhagen. Communicated by S. Elliott Hoskins, M.D. With the view of ascertaining the quantity of carbonic acid ex- haled during the twenty-four hours, as well from the lungs as from the general surface of the body, Professor Scharling undertook the following experiments on six individuals, viz. four males and two females. Chemical Society. 73 The subjects of experiment were confined in an air-tight box, wherein they were perfectly at their ease, being enabled to speak, eat, sleep, or read without inconvenience ; a constant current of at- mospheric air was admitted into the box, and the deteriorated gases abstracted by means of an air-pump. The air withdrawn was con- ducted into a proper arrangement of bottles, some containing sul- phuric acid, others a solution of caustic potash. The quantity of carbonic acid, both previous to and subsequent to each operation, was carefully ascertained, by being received into three graduated tubes. The results were as follows : — 1st. The Professor himself, aged thirty-five years, exhaled 219 grammes* during twenty-four hours, seven of which were spent in sleep. 2nd. A soldier, twenty-eight years of age, exhaled 239*728 grammes = 8*45 oz. 3rd. A lad of sixteen, 224-379 grammes = 7*9 oz. 4th. A young woman, aged nineteen, 165*347 grammes=5*83 oz. 5th. A boy nine years and a half old, 133*126 grammes = 4*69 oz. 6th. A girl of ten, 125*42 grammes = 4*42 oz. In the two last cases the period allotted to sleep was nine hours. From these experiments the Professor deduces that males exhale more carbonic acid than females, and children comparatively more than adults. He also finds that less of this gas is given off during the night than during the day ; and that in certain cases of disease, which he does not specify, less carbonic acid is formed than during the healthy state. He is thence induced to hope that attention to this point may ultimately throw some light on certain forms of disease. It will be interesting to compare these results with Liebig's views, as well as with the experiments which have recently emanated from the French Academie des Sciences. March 21. — Col. Yorke exhibited a specimen of magnesium ob- tained by voltaic action on the chloride of magnesium. The following papers were read : — 74. " On Theine," by John Stenhouse, Ph. D. 75. " Observations on M. Reiset's Remarks on the New Method for the Estimation of Nitrogen in Organic Compounds, and also on the supposed part which the Nitrogen of the Atmosphere plays in the Formation of Ammonia," by Heinrich Will, Ph.D. (See Phil. Mag., S. 3. vol. xxii. p. 286. March 30. — Anniversary Meeting, the President, Thomas Gra- ham, Esq., F.R.S., in the Chair. The following Report of the Council was read by the President, and subsequently ordered for publication : — Report of the Council made to the Cliemical Society of London, March 30, 1843. The completion of a second year of the Society's existence in cir- cumstances of increasing prosperity enables the Council to congra- * = 7*72 oz. avoirdupois. 74; Chemical Society. tulate their fellow-members on the positive attainment of the prin- cipal objects for which they are associated. The Society continues to be augmented in numbers and influence by the election of new Members, and has been well supported by contributions of original papers read at its meetings. The papers presented appear to in- crease both in number and value ; and any apprehension of a want of papers, which formerly existed, has been in a great measure dis- pelled by the experience of the last Session. It is now sufficiently evident that ample materials exist in England for a Chemical So- ciety, and you have furnished unquestionable proofs of the utility of such a Society in its power to advance the cultivation of chemical research in the country. Thirty-one Members have been elected into the Society since the last Anniversary. Our present numbers are — 77 Members resident in London, 57 Members resident in the country, or "non-resident" Members, 10 Associates, and 3 Foreign Members, making a total of 147 Members, with an annual income of £211. The Society has thus early in its career to deplore the loss by death of two Members. HEisrRYHENNJ3LL,Esq., F.R.S., who took an active part in the esta- blishment of the Society, and was a member of the Council first elected. Mr. Hennell will ever hold an honourable place in the history of chemistry, as the discoverer of sulphovinic acid*, one of the earliest achievements in organic chemistry, and which has since formed the starting-point for numerous important inquiries. Mr. Hennell was destroyed by a lamentable accident, which no intelli- gence could have foreseen, in the discharge of his professional duties as Chemical Operator to the Apothecaries' Hall, in the 45 th year of his age. The shock of this deplorable event still unfits us from calmly estimating the scientific merits and highly amiable character of our lost friend. And Mr. Henky Inglis, of Kincaid Print Works, near Glasgow, who, besides cultivating successfully the chemistry of calico-printing, was distinguished for his accurate knowledge of the general science, in the progress of which he took much interest. Mr. Inglis, whose constitution was always delicate, did not outlive his 43rd year. At the conclusion of last Session the Council made a new arrange- ment with the Society of Arts for the use of two rooms for their meetings and a place of deposit for the property of the Society. These arrangements, they have reason to believe, have given general satisfaction to the Members. The Society published the Third Part of its Proceedings and Memoirs in August last, and has another Part at present passing through the press, the great extent of which has occasioned some delay in its publication. There have been received since last Re- port, 41 communications from 21 contributors, of which 20 are printed entire in the 3rd and 4th Parts, and full abstracts given in * Mr. Hennell's paper on the Mutual Action of Sulphuric Acid and Alcohol, reprinted from Phil. Trans., will be found in Phil. Mag., S. 1. vol. lxviii. p. 354. — Edit. Chemical Society. 75 the Proceedings of the remaining 21. These communications are the fruit of numerous and varied inquiries, and form, in the opinion of the Council, a contribution of some importance to the progress of the science. The Council would refer in particular to the full ex- amination and discussion which the process of MM. Will and Var- rentrapp for the determination of nitrogen has received by the ex- periments of Mr. Francis and Dr. Fownes, and more lately in Dr. Will's own comprehensive memoir ; — to the series of useful papers on astringent substances, which they, owe to their valuable con- tributor Dr. Stenhouse ; and to the papers on various subjects con- nected with the metals and the salts by Professors Liebig and Gre- gory, Messrs. Porrett, Croft, Cock, Balmain and Warington, and on organic substances by Professors Liebig, Johnston, Everitt, Drs. Playfair and Fownes ; on agricultural subjects by Dr. Schweitzer and Mr. Chatter! ey ; on voltaic electricity by Mr. Arrott, and on the heat disengaged in combinations by the President. The Council still presses upon these and other contributors not to relax their ex- ertions, and invites the Members generally to communicate the re- sults of their inquiries. The Society has also received presents of interesting chemical products and crystalline specimens for their collection from various donors, particularly Mr. Warington and Professor Liebig. They have also received several chemical works from their respective authors. The Council call attention to this nucleus of a collection which has been formed, and which they hope will be rapidly in- creased by the exertions and liberality of the Members. The Council has also lately made arrangements for procuring the leading chemical Journals and circulating them among the Members. The condition of the Society's finances is highly favourable. The following gentlemen were elected as Officers and Council for the ensuing year : — President. — Arthur Aikin, Esq., F.L.S., F.G.S. Vice-Presidents. — William Thomas Brande, Esq. ; John Thomas Cooper, Esq. ; Thomas Graham, Esq. ; Richard Phillips, Esq. Treasurer. — Robert Porrett, Esq. Secretaries.^— Robert Warington, Esq., and George Fownes, Ph. D. Foreign Secretary. — E. F. Teschemacher, Esq. Council. — Dr. Charles Daubeny ; Thomas Everitt, Esq. ; Michael Faraday, D.C.L. ; J. P. Gassiot, Esq. ; Dr. William Gregory ; Per- cival N. Johnson, Esq. ; James F. W. Johnston, Esq. ; Dr. W. B. Leeson ; W. Hallows Miller, Esq. ; W. Hasledine Pepys, Esq. ; Dr. G. O. Rees ; Lieut.-Col. Philip Yorke. The thanks of the Society were given to the Officers and Council for their exertions during the past year. April 4. — The following communications were then read : — 76. " On the Subsulphates of Copper," by J. Denham Smith, Esq. 77. " On the Spontaneous Decomposition of the Chlorate of Am- monia," by Mr. Joseph Wonfor. Having occasion lately to prepare a quantity of this salt, the phre- 76 Chemical Society, nomena which form the subject of this communication were ob- served. The salt was prepared by adding to a saturated boiling solution of bitartrate of ammonia a saturated boiling solution of chlorate of potassa, the liquor being strained from the precipitated cream of tartar and cooled as rapidly as possible, it being observed that the ammoniacal salt underwent a change if allowed to remain at a high temperature for any length of time ; the solution was then care- fully evaporated at a temperature below 100° Fahr., and again strained from a small portion of cream of tartar which separated as the liquor was concentrated. The chlorate of ammonia crystallizes in small acicular crystals, or in plates similar to the chlorate of po- tassa. The crystals are very soluble both in water and alcohol, and have a sharp cooling taste. This salt was partially examined by Vauquelin, but he does not appear to have observed the change it undergoes at the ordinary temperature of the atmosphere, which most likely arose from his using the salt immediately after it was prepared. In Murray's ' Elements of Chemistry,' vol. ii. p. 544, it is stated that Vauquelin examined this salt : the author remarks, " it crystal- lizes in fine needles, and appears to be volatile, as there is a consider- able loss on evaporating its solution ; its taste is extremely sharp ; it detonates when placed on a hot body with a red flame ; decomposed by heat it gives out chlorine gas, with nitrogen and a little nitrous oxide, hydrochlorate of ammonia with hydrochloric acid remaining." Brande states, in his ' Elements,' on the authority of Vauquelin {Ann. de Chim. xcv. 97), that " this salt probably consists of one proportional of each of its components, or 17 of ammonia -|- 76 of chloric acid ; but its composition has not been experimentally de- termined." I have analysed the salt, by decomposing it with caustic potash, collecting the ammonia in water acidulated with hydrochloric acid, and evaporating the solution carefully to dry- ness ; the chloric acid was determined by igniting the salt, after the action of potash, in a porcelain capsule ; then calculating the amount by the weight of the resulting chloride of potassium, my results gave one equivalent of ammonia, one of chloric acid, and one of water. After the salt had been prepared a few days, the colour was ob- served to have changed from white to lemon-yellow, and gave out an odour which powerfully affected the nose when held over the un- corked bottle, irritating the eyes much more than chlorine, and cau- sing a flow of tears ; this odour was dissimilar to that of any of the oxides of chlorine. The salt was put away till an opportunity should offer of examining the cause of this change. On going into the laboratory some days after the alteration in the appearance of the salt had been observed, the bottle, which contained about 4 ounces, was found broken into innumerable particles, and the remains of its contents strewed about the floor; on inquiry I was informed that during my absence it had exploded with a loud report. Imagining the explosion was produced by the bottle being closely stoppered, an ounce of the salt was introduced into a very strong phial, and con- Intelligence and Miscellaneous Articles. 77 nected with a vessel containing a solution of nitrate of silver, through which the products of the decomposition had to pass, the unab- sorbed gases being collected in a jar at the pneumatic trough, hoping to collect the gases as they were liberated. After gaseous matter had been quietly evolved for twelve hours, it exploded with greater violence than before, no portion of the bottle remaining (except the neck) larger than a pea. A quantity of chloride of silver had pre- cipitated from the nitrate, and the gas jar contained free nitrogen. Another portion of the salt was then placed on a sand-bath, the temperature of which was about 120° Fahr. ; this soon underwent decomposition, but only detonated slightly, giving off dense white fumes, with the smell of nitrous acid. Finding the salt was so easily decomposed, I proceeded to ex- amine more closely the nature of the changes that took place. 20 grains of the salt were introduced into a strong flask, connected, as in the previous experiment, with a vessel containing solution of ni- trate of silver, but with the mercurial instead of the pneumatic trough ; the flask was then very carefully warmed by a spirit-lamp ; the salt instantly exploded with great violence and a loud detonation, breaking the flask to atoms. Five grains of the salt were then ope- rated upon, without the vessel containing the solution of the silver salt, and the products of the decomposition collected over mercury ; they were nitrogen, chlorine, nitrous acid and water, with a little chloride of ammonium; but from the rapidity with which the gases were eliminated, it was impossible to collect the whole of the pro- ducts of the decomposition, though the experiments were repeated six or seven times, both with and without the vessel containing the solution of nitrate of silver. When five grains of the salt were em- ployed, the tubes (which were filled with mercury when no salt of silver was used) were not broken ; still the action was so energetic that it did not allow of accurate indications of the quantity of the gases evolved being obtained. From the presence of free nitrogen and chlorine, both in the pro- ducts of the spontaneous and produced decomposition, I am led to conclude that chloride of nitrogen is formed ; but as the whole of the products were in no case obtained, it was impossible to deter- mine this experimentally. XII. Intelligence and Miscellaneous Articles. NEW ANALYSES OF THE CYMOPHANE (CHRYSOBERYL) OF HADDAM. BY M. A. DAMOUR. THE author states, after reading the analyses of chrysoberyl by M. Awdejew*, he should not have completed the experiments previously commenced, if he had not observed that M. Awdejew's analyses were confined to the chrysoberyls of Brazil and Siberia ; but it appeared to him that it would not be useless to examine the composition of the mineral from Haddam, which occurs in well-de- fined crystals in the midst of the primitive rocks of Connecticut. Three analyses were performed in the following manner : — In ♦ S. 3. vol. xxii. p. 501. 78 Intelligence and Miscellaneous Articles. order to prevent any admixture of silica by using an agate mortar, the mineral was powdered in a steel mortar. The powder was di- gested in hot hydrochloric acid and carefully washed, in order to dissolve the iron acquired from the mortar ; it was then dried and weighed. It was then fused at a low red heat in a platina crucible with six times its weight of freshly-prepared bisulphate of potash. In half an hour the fusion and decomposition of the mineral were complete ; the mass was dissolved in boiling water and filtered ; there remained but a few unimportant particles of micaceous or siliceous matter arising from an accidental admixture. The clear solution was saturated with ammonia ; the alumina, glucina and oxide of iron were thus precipitated and separated from the bisul- phate of potash. In order to separate the alumina and oxide of iron from the glu- cina, they were at first dissolved in a slight excess of hydrochloric acid, and the solution was poured into a large quantity of solution of carbonate of ammonia, which precipitated the alumina and oxide of iron and retained the glucina ; but by this method only about 1 2 of every 100 parts of glucina could be obtained. This process was therefore abandoned, and the method employed by M. Awdejew was adopted ; this consists in dissolving the recently precipitated alumina and glucina in a cold solution of potash, the oxide of iron is thus separated ; the alkaline solution is then to be diluted, and on boiling it, glucina is precipitated in white flocks, which are easily washed ; it dissolves entirely in acids and in excess of carbonate of ammonia ; the alumina retained in solution by the potash is precipitated in the usual manner. The oxide of iron was observed in each operation to carry with it a notable quantity of glucina ; in order to separate them they were dissolved in hydrochloric acid ; the solution was supersaturated with carbonate of ammonia, and the iron was precipitated with hy- drosulphate of ammonia. The glucina was separated by boiling the solution from which the sulphuret of iron had been precipitated ; and after washing and heating to redness it was added to that px-e- viously obtained. The mean of three analyses gave as the composition of cymo- phane, — • Alumina 75*26 Glucina 18-46 Peroxide of iron .... 4'03 Sand 1-45 99-20 M. Damour remarks, that not knowing any mode by which to determine directly the degree of oxidizement of iron in minerals not acted upon by acids, he leaves undecided the question as to the mode of its existence in the cymophane, as to whether it is in the state of protoxide, or of peroxide isomorphous with alumina. — Ann. de Ch. et de Phys., Fev. 1843. ACTION OF NITRIC ACID ON CARBONATE OF LIME. BY M. BAR- RESWIL. It is generally admitted by chemists as a fact, that marble is not Meteorological Observations. 79 acted upon by nitric acid of the greatest density. M. Barreswil, desirous of ascertaining whether this anomaly was due to the same want of action of this acid on certain metals, kept a piece of marble in concentrated nitric acid, and it was not visibly acted upon. It was then removed from the acid, washed, dried and powdered, and the powder was put into fresh concentrated acid ; it was strongly acted upon, but not entirely dissolved. A little water was then added to the acid, the reaction again took place, and after some time ceased, but recommenced on the addition of more water. It may be concluded from these facts that marble is attacked by concentrated nitric acid with energy proportional to its surface, becoming covered with a varnish of nitrate of lime insoluble in concentrated nitric acid. This nitrate of lime concentrates the nitric acid in which it is produced, and renders it strong. The experiment performed in a direct mode was perfectly conclusive : dried nitrate of lime, put into nitric acid of moderate strength, concentrated and rendered it fuming. — Ibid. METEOROLOGICAL OBSERVATIONS FOR MAY 1843. Chiswick. — May 1. Cloudless : cold and dry. 2. Fine. 3. Very fine. 4. Cloudy and fine : rain. 5. Rain : cloudy: constant and very heavy rain at night. 6. Heavy rain : clear and cold at night. 7. Clear and fine : showery : frosty at night. 8. Hazy : heavy rain. 9. Drizzly: cloudy. 10. Slight haze : clear and cold at night. 1 1 . Light haze : clear. 12, 13. Very fine. 1 4. Cloudy and fine : heavy rain at night. 15, 16. Rain. 17. Heavy showers. 1 8. Densely overcast : cold rain. 19. Rain: cloudy. 20. Cloudy: showery: heavy rain at night. 21. Fine : heavy rain : clear and cold at night. 22. Heavy showers. 23. Cloudy: lightning with rain at night. 24. Heavy rain : clear. 25. Cloudy and fine. 26. Rain. 27, 28. Showery. 29. Hazy. 30. Light haze : very fine : showery. 31. Cloudy and mild. — Mean temperature of the month 3° below the average. The quantity of rain was greater than that which has fallen in any month within at least the last seventeen years. Boston. — May 1, 2. Fine. 3. Cloudy. 4. Fine. 5. Cloudy: rain early a.m. 6. Rain : rain a.m. and p.m. 7. Cloudy. 8. Cloudy : rain p.m. 9 — 11. Cloudy. 12. Fine. 13. Cloudy : rain p.m. 14. Fine. 15. Rain : rain p.m. 16. Cloudy : rain early a.m. 17. Cloudy. 18, 19. Cloudy: rain early a.m. 20. Cloudy. 21. Cloudy: rain early a.m.: rain p.m. 22. Fine. 23. Cloudy: rain a.m. 24. Windy : rain a.m. 25. Fine : rain a.m. 26. Fine. 27. Fine : rain, with thunder and lightning p.m. 28, 29. Fine. 30. Fine : halo round the sun 1 1 a.m. 31. Cloudy : rain early a.m. This has been the wettest May we have had since 1830. Sandwich Manse, Orkney. — May 1. Fine: fog. 2. Cloudy: fog. 3. Clear: cloudy. 4. Rain : cloudy. 5. Cloudy : clear. 6. Clear : cloudy. 7. Rain : cloudy. 8. Clear. 9. Clear : cloudy. 10,11. Clear : fine. 12—14. Cloudy. 15 — 17. Clear. 18. Cloudy : fine. 19. Cloudy: showers. 20. Bright : clear. 21. Bright: cloudy. 22 — 24. Bright: clear. 25. Rain. 26. Cloudy. 27. Damp. 28. Cloudy : sleet-showers. 29. Snow-showers : sleet-showers. 30. Bright: fine. 31. Clear: fine. Applegarth Manse, Dumfries-shire. — May 1 — 3. Fair and fine. 4. Fair till p.m. : rain. 5. Heavy showers. 6. Fair and fine. 7. A shower. 8, 9. Fair. 10, 11. Fair : hoar-frost. 12. Fine : rain p.m. 13. Fine and mild. 14. Fine, but cloudy. 15. Showers. 16. Cloudy and cold. 17. Cool : cloudy. 18. A shower. 19. Cold. 20. Cold : fair. 21. Cold: wet. 22. Milder, but showery. 23. Mild : cloudy. 24. Cold and rainy. 25. Soft rain. 26. Mild : showers. 27. Mild : showery. 28. Cold and rainy. 29. Clear: heavy rain. 30. Soft: growing : thunder. 31. 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OJOJOJ COCOCMCMCMCMCMCMCMWCOCNCMCMCNCMCMCMCMCMCMCMINCMCMOJWCMCMW ©■^< ^COtOCOCOOll-Nh — CO © on->» - - .. — « — — — o 01© cr.w© oico -t co c l00^-«^( !^tpOlQOCOtOtpl>^tptp^CO©©CO ■j Oj 01 © © 01 1CM(NC>IC>|CM«CMCOCOCOCN71CMCNCMCMC1C^CMCMCMCMCMCMCMCMCOCO( •oos -Xoy :uopuo'j ©tOCM»©CMtOtOCM^-#CMC0C0^01C0C COCO-T©CMOir^.Ol-T-^'CO©f-t,-f,CO — u «^OlXKrttO«0'00(NIN05CCmf'OQ ©X-ftOCOCCMtOT*1©© JO sXbq Sfi$M3nNia i^.to --o -r j ^ 1— i 01 30 l^cs (t?"J*J. »C to t^* tf! ifl Ol*1* I C © OlOjOlOlOlOlOl© © © OlOlOlOlOlOlOlOlOlOlOlOlOlOlOl OlOl© t C0COCNC^CMCNC^CMNC0C0C0C'»WCMCMCMC>l^CMCMCMCNC^C^«WCMC^ m n co ■** « to nco cf)©' ^' w n t" >«* and when compared with dammaran — Dammaran . . . C^ H31 Oe Dammarol . . . C40 H28 03 H3 03 = 3 HO shows the removal of 3 atoms of water. The analysis gives an excess of hydrogen from the retention of some water. The action of heat upon resins was known as early as 1688 (Memoires de VAcademie Hoy ale des Sciences de Paris, 1688), and the relative proportions of water and oil obtained by the distillation of these bodies was accurately noted. Colophon or common resin, for example, it is stated, when distilled in the quantity of 2 pounds, afforded 26 ounces 4 drachms of oil, and 3 ounces 1 dr. of an acid liquid. Neumann, a most sa- gacious chemical writer, whose works may even yet be con- sulted with benefit by modern chemists, was well aware of the nature of resin. " Essential oils," he says, " by digestion or heat (Neumann's Chemistry, by Lewis, 4to. 1758, p. 269) change into balsams, and at length into brittle resins. Di- stilled again in this state they yield, like most of the natural resins, a portion of fluid-oil." The effect of heat in removing water from resin, as now stated, enables us to explain the process for preparing copal Dr. R. D. Thomson on the Cowdie Pine Resin. 87 varnish. Copal in its natural state is insoluble in oil of tur- pentine ; but when fused and boiled until water is removed, the residual oil (Copalol?) is soluble in that menstruum. The nature of the product from the distillation of resins depends on the temperature. From a mixture of oils procured by di- stilling common resin at a high temperature I have obtained a considerable proportion of creasote. Dammarone. When dammara resin is finely pounded and mixed inti- mately with 5 or 6 times its weight of quicklime, and the united powders are distilled by the heat of a spirit-lamp care- fully, either in a tube retort or in a larger vessel, if the quan- tity experimented on is more considerable, dense white fumes speedily make their appearance, which condense in the re- ceiver first in the form of water, having an aethereal odour, and gradually as a thick amber-coloured oil, which floats on the surface of the water. By the application of heat the water soon disappears, while a dark oil remains, which may be further purified by rectification. This oil is exceedingly liquid when hot, but on cooling and exposure to the air it be- comes thicker. Its boiling point is above 270° F. It burns with a dense smoke, and is soluble in alcohol. 4*3 grs. gave when burned with oxide of copper 13*59 C02 and 4-465 grs. HO. This is equivalent to Carbon 86*22 Hydrogen 11*53 Oxygen 2*25 100- This corresponds nearly with Carbon .... 38 x '15 = 28*5 85*64 Hydrogen . . 30 x '125= 3*75 11*27 Oxygen .... lxl* ■ 1' 3*09 33*25 100*00 The comparative formula will then be Dammaran . . C40 H31 06 Dammarone . . C38 H30 O ~~2 I 5 = 2 C02 + HO. The experimental result gives a larger amount of carbon, which I believe to be owing to the difficulty of separating the whole of the carbo-hydrogen oil which forms the basis of the resin, and is disengaged in the first stage of the distillation. All those who are familiar with this branch of chemistry are aware of this obstacle to precise formulas. The experiment 88 Dr. R. D. Thomson on the Coisodie Pine Resin. shows that two atoms of carbonic acid and one of water have been removed by the action of the lime. That carbonic acid is fixed by the lime, is proved by the effervescence which takes place when acid is poured on the residue in the retort. Dr. French of London, in his * Art of Distillation,' pub- lished in 1664, was aware that by means of lime, oils might be extracted from " resins, gums, fat and oily things." To obtain them, he directs 1 lb. of any of these to be distilled with 3 lbs. of the powder of tiles or unslaked lime. I have not been able to find any notice of these facts in Glauber or any ante- rior writer. The preceding experiments assist in carrying out certain generalizations which had been deduced from a limited series of data, and serve to confirm the idea of the analogy of the resins, and of their derivation from an oil of the turpen- tine type. The resins perhaps are more interesting to the chemist than at first appears, from their analogy to other bodies of vegetable and animal origin. Whether their basic oils are derived from the deoxidation of other bodies in plants supplied with a larger amount of oxygen, or are formed di- rectly from their gaseous constituents, is a subject for inquiry. If it be true that plants evolve no heat (although it is not easy to comprehend how gases can be condensed without such a disengagement), then it would appear that no combination of carbon and oxygen, no proper combustion, such as occurs in the animal system, takes place in plants ; and hence it would follow that the essential oils are formed directly from their elementary constituents. But the statement ( Brongniart) which has been made that plants evolve heat in fertilization, that oxygen is absorbed and carbonic acid given out, would appear to favour the idea that combustion can occur in plants as well as in animals. The admission of the operation of this process in plants, would throw much light on the following table, representing a descending series, with the exception of the first, into which some bodies of animal origin are intro- duced for the sake of comparison. Protein C48 H^. 014 N6 Gum C48 H^ O^ Starch . C43 H40 O40 Base of cane-sugar . C48 Hgg O^ Fat CM H40 04 Bees-wax C40 H40 02 Dammaran C40 H31 Os Cholesterin C38 H32 O Dammarone C38 H30 O Base of resins . . . C40 H32 The Rev. B. Bronwin's Reply to Mr. Cayley's Remarks. 89 In reference to the preceding table, the analogies of starch, gum and sugar are sufficiently familiar, both in the artificial processes, by which the former may be transformed into the latter, and in the changes produced by vegetation. The con- version of sugar and honey into wax by bees was long ago shown by Huber, and has lately been brought forward with happy effect by Liebig, in evidence of the part which the sac- charine class of bodies performs in the respiratory ceconomy. The intermediate position which fat holds between sugar and wax would seem to point to it as a stage in the process of re- duction. The analogy between wax and cholesterin is suffi- ciently striking as products of reduction from an amylaceous or saccharine base ; and this idea has been strengthened by the circumstance of my having obtained from the latter bodies bearing a close analogy to the turpentine and naphtha type, while the opinion has gained support, which I entertain, that cholesterin is the wax of mammiferous animals. The corre- spondence of resins to these bodies is sufficiently apparent. XIV. Reply to Mr. Cayley's Remarks. By the Rev. Brice Bronwin*. A DESIRE to see the paper which I last transmitted to this Journal printed before my reply to Mr. Cayley, has occasioned this delay in noticing his remarks of the 13th of April ult. (inserted in the Number for May, p. 358) on a for- mer paper of mine. With respect to the second form of w, he says, that I by no means show that Jacobi's formulae fail, but rather confirm them. Now I did not say that they failed for it, but only that they were reducible till it disappeared, and that with it their second members were improper representa- tions of the first. And if this be correct, which Mr. Cayley does not deny, it is surely to be discarded from the theory. For the other three forms, Mr. Cayley thinks that when u = co, -^ might be p H + pf H' V — 1, and s a v = ± 1, 0, + oo \/_ i or + — • I presume he means — , not -^-. I consider that the structure of the formulas implies that s a «, c a rr do not exceed the limits + 1, and therefore reject * Communicated by the Author. 90 The Rev. B. Bronwin's Reply to Mr. Cayley's Remarks. + oo */ — 1 and + — . And as 0 relates to the second form A of ca, it is to be rejected. There is certainly room for discussion as to whether the quantities p and p' are to be determined or assumed. I assumed them, and took the least values, because it did not affect my conclusions. Were I to discuss the va- rious points to which this difference between me and Mr. Cay- ley gives rise, I should extend this paper to too great a length. And as I think I can place the subject in a clearer light by a much shorter process, I prefer doing so. But first I must beg to call Mr. Cayley's attention to a real transformation at page 54 of Jacobi's work. It is derived K' V^T by the aid of imaginary quantities, and from an co as , and is therefore of the third form. Will Mr. Cayley be pre- vailed upon to make trial of it in its simplest case, or when n = 3, and see if he find it to be a transformation ? It is but right to say that I have done so, and did not make it to be one. And if I am correct, this must be fatal to the third form of oo. And I must observe, that though Jacobi has shown the possibility of such a transformation as he has given, by show- ing that there are sufficient equations to determine the con- stants, he has not shown that any and every value of od will give one. Suffice it that there is one value, or a series of values, namely those included in the first form of this quantity. Nor has he assigned any reasons for the different forms of it which he has suggested. Moreover, he has set out from an assumed equation 1 —< g =y(a?), page 39, from which all the rest of the formulas are derived. In this assumed equation he has not actually determined the constants, but only assumed them. If they were actually determined, it might appear that they are not susceptible of that generality which their author and Mr. Cayley suppose. M. Jacobi's formulae, as Mr. Cayley has reduced them, are sausa (u + 2a>) sa (u + 2 (n — 1) w) . sav=s sfl(K-2«)s«(K-4eo)..sfl(K-2(«-l)«) "' I 5 cauc a(u + 2co) c a (u + 2 (n — 1 ) w) ,„ . c a v = 5 -r1 7T-, tt ' — - ... (2.) The numerator of (1.) when developed is sau (s* al2 a> — s* a it) and that of (2.) is ca«(s2fl(K-2w) -s2am) The Rev. B. Bronwin's Reply to Mr. Cayley's Remarks. 91 These formulae, therefore, by suitable values of u, are con- structed to fulfil the conditions s a » = 0, c av = _+ 1, and also sa»= + l, c a w = 0. And it must be possible to satisfy them both. For at page 40, in deriving the value of y — s a v from that of 1 — y, Jacobi finds y m 0 when u = 0, 2 co, &c. And at page 41, in finding the value of M, he makes x ~ s a u = 1, y = 1. Also the values of A, and of 1 ± ^y depend on those of M and of y. Both these condi- tions therefore are at the very foundation of Jacobi's theory. He also makes u, u + 2 w, &c, and even 0, 2 co, 4 co, &c, successive values of u. This decides the form of u. If the general form of co be , that of u is 1 - ; 0 and Q' being real elliptic functions, having the common amplitude >j, and the moduli h and k' respectively. When tj = 0, y, p, &c, 0 = 0, K, 2K, &c; fl'=0, K', 2K',&c; and m=0, w, 2 eo, &c. For the three forms of co which we have to consider these values of u fulfil the condition sav=0,cav=: + l. For the first form of w, when the denominator of (1.) reduces tosacosa3co , the values u = 0, 9 co, &c. satisfy the condition saw = jfl, cai; = 0 also. But for the third and fourth forms this denominator cannot be so reduced, nor can u be made to take any of the forms K — 2 co, K — 4 co, &c, or 2 co — K, 4 co — K, &c. For it could only assume them when »j has some of the values — , tt, &c, and conse- quently 6 and 9' some of the corresponding values K, K', 2 K, 2 K', &c. But for none of these values will u become any one of the quantities 2 r co — K. The third and fourth forms of co therefore will not fulfil the conditions to which the formulae have been subjected, and consequently they must be rejected. We might take a shorter course. It is sufficient to observe that the first form of co only will satisfy the conditions sau= 0 and sau = 1 required by Jacobi's theory, pages 40 and 41. Mr. Cayley says, I have brought no objection against any particular step of Jacobi's reasoning. I suppose them to be all quite correct. But any assumed form of co will not neces- sarily fulfil all the required conditions. It must be remem- bered that these forms are assumed, not determined. B. Bronwin. Gunthwaite Hall, June 15, 1843. [ 92 ] XV. Additional Objections to Redfield's Theory of Storms. By Robert Hare, M.D., Professor of Chemistry in the University of Pennsylvania*. 50. TNa communication to the London and Edinburgh Ma- *■ gazine and Journal of Science for December 1841, I endeavoured to point out various errors and inconsistencies in the theory of storms proposed by Mr. Redfield, or in the rea- soning and assumed scientific principles on which that theory had been advanced. Of these errors I will present a brief summary. 51. I conceive that Mr. Redfield has erred in ascribing atmospheric currents, whether constituting trade winds or storms of any kind, " solely to mechanical gravitation as con- nected with the rotatory and orbitual motion of the earth f." 52. In ascribing those atmospheric gyrations, of which ac- cording to his hypothesis all storms consist, to " opposing and unequal forces," without specifying the nature or ac- counting for the existence of these forces, although implying that they originate as above mentioned. 53. In assigning to all fluid matter a tendency to " run into whirls and circuits, when subjected to opposing and unequal forces," when this allegation, if true at all, can only be so in some peculiar cases of such forces. 54. In alleging all storms to be whirlwinds, and yet repre- senting a M rotative movement in air as the only cause of de- structive winds and tempests," so that a whirl is the only cause of its own violence %. 55. In averring, in reference to the alleged gyration and vortical force of tornadoes which are by him treated as hurri- canes in miniature, that " all narrow and violent vortices have a spiral involute motion quickening in its gyration as it ap- proaches the centre or axis of the whirl," whereas it must be evident that when gyration in a fluid does not result from a contemporaneous centripetal force, arising from an ascending or descending current at the axis, but on the contrary exists only in consequence of a momentum previously acquired, the consequent velocity in any part of the mass affected, will be less in proportion to its proximity to the axis : also that the only case in which it can increase with its proximity, is where the mass is fluid and it proceeds from some competent cause acting at the axis. 56. In representing that the upward force of tornadoes * Communicated by the Author. Mr. Redfield's papers will be found in Phil. Mag. S. 3. vol.xx. p. 353; vol. xxii. p. 38. t See paragraph 60 of this essay. J Silliman's Journal, vol. xxi. p. 192 : " Storms and hurricanes consist in the regular gyratory motion or action of a progressive body of atmosphere, which action is the sole cause of the violence which they may exhibit." Additional Objections to Redfield's Theory of Storms. 93 is the effect of a vortical or gyratory action *, when it must be quite plain that a " vortical" action or whirling motion in- stead of causing the air upon the terrestrial surface, necessarily subjected by it to a centrifugal force, to seek the centre, would induce that portion of the atmosphere which should be above the sphere of the gyration, to descend into the central space rarefied by the centrifugal force. 57. In admitting the gyration, which he considers as the cause of storms, to quicken as it approaches the axis of mo- tion, without perceiving that this characteristic is irreconcilable with his inference that gyration caused by forces acting re- motely from the axis is the proximate cause of all the phseno- mena in question. 58. In the number of Silliman's Journal of Science for April, 1842, Mr. Redfield has hinted that the pains which I have taken to confute his doctrines are disproportioned to the low estimation in which I have professed to hold them. I should be glad if this view of the subject should render my strictures agreeable to him ; and am sincerely sorry that, con- sistently with truth, I cannot directly take a course more fa- vourable to his meteorological infallibility. I admit that his essays have met with an attention which may have justified him in pluming himself on their success. Had it been otherwise, I should not have thought it worth while to enter the lists. It strikes me, however, that a fault now prevails which is the opposite of that which Bacon has been applauded for correcting. Instead of the extreme of entertaining plausible theories having no adequate foundation in observation or experiment, some men of science of the present time are prone to lend a favour- able ear to any hypothesis, however in itself absurd, provided it be associated with observations. But to proceed with the " reply," so called, the author alleges that in the absence of " reliable facts and observations" in support of my objections to what he considers as the " established character of storms," he had hesitated to answer them. This cannot excite sur- prise, when it is recollected " that the whole modern mete- orological school," and likewise " Sir John Herschel," are ac- cused by him of a " grand error," in not ascribing all atmo- spheric winds " solely to the gravitating power as connected with the rotary and orbitual motion of the earth." 59. For this denunciation he has no better ground than that on which he deems his theory to be above my reach, that is to say, because himself and others have made some observa- tions showing that in certain storms, agreeably to log-book records, certain ships have had the wind in a way to indicate * See paragraph 92 of this communication. 94 Dr. Hare's Additional Objections to gyration. Being under the impression, that in many instances no better answer need be given to Mr. Redfield's opinions than that created in the minds of scientific readers by his own lan- guage, I will here quote his denunciation of the opinions of the meteorological school and of Herschel. 60. " The grand error into which the whole school of me- teorologists appear to have fallen, consists in ascribing to heat and rarefaction the origin and support of the great atmospheric currents which are found to prevail over a great portion of the globe. * * * An adequate and undeniable cause for the production of the phasnomena * * I consider is furnished in the rotative motion of the earth upon its axis, in which ori- ginate the centrifugal and other modifying influences of the gravitating power, which must always operate upon the great oceans of fluid and aerial matter, which rest upon the earth's crust, producing of necessity those great currents to which we have alluded." — (See Silliman's Journal, vol. xxviii. p. 316.) Speaking of Sir John Herschel's explanation of the trade winds and others, Mr. Redfield alleges, " Sir John has however erred, like his predecessors, in ascribing mainly, if not pri- marily, to heat and rarefaction those results which should have been ascribed solely to mechanical gravitation as connected with the rotative and orbitual motion of the earth's surface." 61. Is it not surprising that it did not occur to the author of these remarks, that an astronomer so eminent as Sir John Her- schel would be less likely than himself to be ignorant of any atmospheric influence resulting from gravitation or the diurnal and annual revolutions of our planet — and that when he found himself in opposition to the whole school of meteorologists, a doubt did not arise whether the "grand error" was not in his views of the subject instead of that which they had taken ? 62. It seems to have been forgotten, that all the aqueous portion of the terrestrial surface being, no less than the super- incumbent atmosphere, subjected to the gravitating power and the rotary and orbitual motions of our planet, no impulse can be given to the one which is not received by the other ; and that as the heavier the fluid the greater the influence, if this be competent to create gales in the atmosphere, it must be no less competent to produce torrents in the ocean. Moreover, do not his opinions conflict not only with the whole school of meteorologists, but also with a portion of the modern school of geology? Agreeably to the last-mentioned school, the ex- ternal portion of the earth consists of a comparatively thin shell of earth and water floating upon an ocean of matter kept in fusion by heat ; the oblate spheroidal form of our planet being due to the perfect equilibrium of the " gravitating, ro- Redfield's Theory of Storms. 95 tary, and orbitunl " forces which are most inconsistently re- presented by Mr. Redfield as having upon the atmosphere an opposite effect. 63. But notwithstanding the opinions expressed in the pa- ragraphs above quoted, and in the following, Mr. Redfield alleges in his reply to my objections, that it is an error to con- sider him as rejecting the influence of heat. It is very possible that his opinions may have changed since he read my " objec- tions;" but that he did reject the influence of heat when the preceding and following opinions were published must be quite evident. " Were it possible to preserve the atmosphere in a uniform temperature all over the surface of the globe, the general winds would not be less brisk than at present, but would be more constant and uniform than ever." — (Silliman's Journal, vol. xxviii. p. 318.) 64>. Mr. Redfield alleges that the proper inquiry is, What are storms ? not How are storms produced ? And yet it will be found that his great object has been to show that they arise from gyration caused by unequal forces generated in some in- explicable mode by gravitation and the complicated motions of our planet. But suppose that before ascertaining how fire is produced, chemists had waited for an answer to the question what is fire, how much had science been retarded ! I do not therefore blame Mr. Redfield for pursuing both inquiries si- multaneously, inconsistently with his own rule above stated, but I am astonished that he should, without any new experi- ments or any demonstrations, by an ipse dixit undertake to make a novel application of the gravitating power, and the forces arising from the earth's motion ; and to inform one of the most eminent astronomers of the age that he had com- mitted an error in overlooking their all-important meteorolo- gical influence. 65. Turning from an endless controversy with a writer with whom I differ respecting first principles, I shall address myself to that great school of meteorologists who concur with me in the "grand error" of considering heat and electricity as the principal agents of nature in the production of storms, and who do not concur with Mr. Redfield in considering jjravita- tion and the earth's annual and diurnal motion as the great destroyer of atmospheric equilibrium. So far as it may con- duce to truth, I shall incidentally notice some parts of Mr. Redfield's reply; but my main object will be to show the in- consistency of his theoretic inferences with the laws of nature, and the facts and observations on which those inferences are alleged to be founded. To follow him in detail through all the misunderstandings which have arisen, and which would inevi- 96 Dr. Hare's Additional Objections to tably arise during a continued controversy, would be an Ixion task. 66. Speaking of the trade winds and monsoons, our author states, " It is to the operation and effect of these great and regular moving masses, that we are disposed mainly to ascribe the more active and striking meteorological phaenomena of every latitude." And again, " At these seasons the northern margin or parallels of the trade winds sweeping towards the gulf, must necessarily come in collision with the great archi- pelago of islands which skirt the Carribean Sea ; * * * (Silliman's Journal, vol. xx. p. 31,) the obstruction which they afford produces a constant tendency to circular evolution. * * * These masses of atmosphere thus set into active re- volution continue to sweep along the islands with increased rapidity of gyration until they impinge upon the American coast." " We have assumed that the leading storms of the northern and western Atlantic and theAmerican coast originate in detached and gyrating portions of the northern margin of the trade winds, occasioned by the oblique obstruction which is opposed by the islands to the direct progress of this part of the trade, or to the falling of the northerly and eddy wind upon the trade, or to these causes combined." — (Silliman's Journal, vol. xx. p. 48.) 67. I trust it will be sufficiently evident, that although great and regularly moving masses of air, by encountering obstruc- tions, may undergo a transient deflection, and that a portion accidentally caught in a strait with high cliffs on either side might, like the tide in the Bay of Fundy, acquire a local and temporary acceleration, yet that it would be utterly impossible for a durable whirlwind to be thus excited. Obviously for the endurance of a whirl, if not for its production, the continuous application of at least two forces would be requisite, of which one must be endowed with a centripetal efficacy in order to counteract the concomitant centrifugal momentum. It will be evident that although a local obstruction may cause an eddy or whirl in its vicinity, the rotary momentum thus created must soon be exhausted. But admitting that a blast by being deflected by an island could become a permanent whirlwind, obviously the resulting velocity could not be so great as that of the generating current. The moderately blowing trade wind could not, by contact with an inert body, acquire an in- crease of velocity adequate to form a furious hurricane capa- ble, as represented, of travelling circuitously for more than two thousand miles. 68. The hurricane once created, agreeably to the imagina- tion of Mr. Redfield, its subsequent progress is described in Redfield's Theory of Storms. 97 the following language : — " This progress still continues while the stormy mass is revolving around its own moving axis ; and we can readily comprehend the violent effects of its un- resisted rotation, while this velocity becomes accelerated by nearly all the oblique forces and perhaps resistances of the circumjacent currents or masses of moving atmosphere. These storms cover, at the same moment of time, an extent of con- tiguous surface, the diameter of which may vary from one to five hundred miles, and in some cases have been much more extensive. They act with diminished violence towards the exterior, and with increased energy towards the interior of the space which they occupy." (Silliman's Journal, vol. xxv. p. 114.) 69. Thus it is assumed, that a mass of air from " one to five hundred miles in diameter" being made to whirl with the velocity of a most furious gale, is not only " unresisted " by the waves, forests, hills and mountains which it may en- counter, but is actually "accelerated by nearly all the oblique forces and perhaps Resistances" which it may meet. Yet it must be quite clear, that any reaction with currents not moving the same way, or moving with an inferior velocity, or obliquely, could only be productive of retardation. 70. The following inconsistencies will show how far Mr. Redfield's account of the phenomena of storms is to be deemed sufficiently accurate or consistent to overset the established principles of science. 71. "The rotation of a continued whirlwind involves not only changes in the position and condition of its constituent particles, but a constant accession of the exterior atmosphere to the body of the whirlwind, together with a discharge equally constant spirally at one extremity of its axis of rotation." (Franklin Journal, vol. xix. p. 122.) Ibid., p. 120: " Nor is it my intention to deny any movement or upward tendency at the centre of a whirlwind storm, for of such a movement, apart from theory, I have long since obtained good evidence." Ibid., p. 122: " In regard to the depression of the barome- ter which I have ascribed to the rotary action of whirlwind storms, Mr. Espy has himself shown, that the centrifugal ac- tion in a storm which gyrates horizontally must tend to with- draw or rarefy the air at the centre by causing a transfer or accumulation towards the exterior of the storm, thus causing a higher state of the barometer around the exterior border, than at the centre of the gale. This connexion and result is in strict accordance with the facts of the case as exhibited in all storms of this character, so far as my observations and in- formation extend." Phil. Mag. S.3. Vol. 23. No. 150. Aug. 1843. H 98 Dr. Hare's Additional Objections to 72. On opposite sides of the same leaf we find the preceding quotations, Agreeably to the first, there is a constant acces- sion of air from the exterior atmosphere to the body of a whirlwind, attended by an upward force and compensated by a discharge at one extremity of its axis of rotation ; agreeably to the last, the centrifugal action tends to withdraw the air of the centre by causing a transfer or accumulation towards the exterior border. 73. In tornadoes the author admits the undeniable exist- ence of an ascending column at the axis (92.), and we are told that a whirlwind storm " operates in the same manner and exhibits the same general characteristics as a tornado* ;" but this idea is evidently irreconcilable with that of a withdrawal of air from the centre, agreeably to one of the contradictory allegations above cited. 74. Nor are the following observations more consistent. " During the passage of these eddies or storms over the place of observation the barometer sinks while under their first or more advanced portions and rises as they pass over or recede." (Silliman's Journal, vol. xxv. p. 129.) " The barometer, whether in higher or lower latitudes, always sinks while under the first portion or moiety on every part of its track excepting perhaps its extreme northern margin." " The mercury in the barometer always rises again during the last portion of the gale and commonly attains the maximum of its elevation on the entire departure of the storm." 75. But if " a higher state of the barometer be created around the exterior border of a whirlwind than at the centre," and if of necessity the exterior border be first encountered, how does it happen that precisely about this space, agreeably to the statement last quoted, the barometrical column should sink? And if, agreeably to the statement quoted previously, the air be rarefied about the centre and accumulated towards the border, in passing from the one border to the other through the centre, would not the mercury in the barometer first rise, then sink, and afterwards rise again, instead of falling during its exposure to one moiety of the storm, and rising during ex- posure to the other? 76. It may be presumed, that respecting the state of the barometer and the movement of the air, within the sphere of his whirlwinds, Mr. Redfield's views are not in accordance with any settled notions. His theory leads to the idea of a centri- fugal force, rarefying and removing the air from the centre, while his observation of the ascending current in tornadoes has tended to create an opposite impression. * Silliman's Journal, vol. xxv. p. 117. Redfield's Theory of Storms. 99 77. Considering the inconsistencies of Mr. Redfield's " re- liable facts and observations," I hope I may be allowed to show what ought to ensue according to his own premises. Evidently in a whirlwind, constituted as are those to which we have reference, the centrifugal force will cause an accumu- lation of air towards the exterior until the otherwise uncoun- teracted pressure of the accumulation, tending to restore the level, is in equilibrio with the centrifugal force. Moreover, the reaction of the fluid lying in the same plane beyond the whirl, will cause the fluid to be higher, or if elastic, denser at an intermediate point than the general level. In the case of an elastic fluid like the air, condensation will be substituted for accumulation, and will amount to the same thing in effect. It would follow, that as the whirl should advance, the baro- meter would rise until the front limb of the zone of greatest condensation should arrive ; subsequently it would fall till the central space should arrive, and then another rise and subse- quent fall would ensue during the approach and departure of the rear limb of the zone of greatest condensation. 78. One fact is mentioned among the contradictory evidence above quoted, which seems to be supported by universal ex- perience. The barometrical column does fall at the com- mencement of a storm, and of course this fact does not accord with the idea that storms are whirlwinds produced by me- chanical forces remote from the axis and attended necessarily by a centrifugal action which would accumulate the air to- wards the exterior. 79. Respecting another characteristic, the " reliable facts and observations of our theorist" are no less irreconcilable than in the case last considered. I allude to the changes in the di- rection of the wind which ensue from the commencement to the end of a hurricane, and especially on the outer limbs on each side of the line of progression. 80. Thus, speaking of the progress of a storm from south- west to north-east along the coast of the United States, he al- leges that " along the central portions of the track the first force of the wind is from a point near south-east, but after blowing for a certain period it changes suddenly, and usually, after a short intermission, to a point nearly or directly op- posite to that from which it has previously been blowing ; from which opposite quarter it blows with equal violence till the storm has passed over or abated." Again, " It is demon- strably evident, that at any point over which the centre of a whirlwind may pass, the wind must suddenly change to a di- rection almost exactly opposite to that which has been felt during the preceding part of its progress." (Silliman's Journal, H2 1 00 Dr. Hare's Additional Objections to vol. xx. p. 22.) " It sometimes happens, when the central portion of an extensive storm passes over or near the point of observation, that the comparative calm, or lull which prevails about the apparent centre of rotation is preceded by a gradual rather than a sudden abatement of the wind." " Every expe- rienced navigator will shrink with instinctive apprehension from the very idea of those moments of awful stillness which place him in the central vortex of the hurricane." (Franklin Journal, vol. xix. p. 116, and Silliman's Journal, vol. xx. 81. Amid the neutralization of evidence which inevitably results from the conflicting statements above quoted, I will endeavour to point out the results which ought to ensue if the inferences of the advocates of the whirlwind doctrine were correct. 82. When a rotary motion is communicated to a solid by a force applied to any part whatever, the tangential velocity at any point will be directly as its distance from the centre. In a fluid, when the force productive of rotation is applied at any point remote from the axis, the motion at the axis can be no quicker than in the case of a solid, but may be slower, since the parts do not of necessity move simultaneously. In the case of a fluid body kept in motion by a momentum re- sulting from forces previously applied, as in the instance of a Redfield whirlwind, any zone, which has been made to re- volve by the direct application of force, will be retarded until it causes, in the adjoining zones, a due proportionable velo- city. This will not be attained until the whole rotates like a solid. There is however this difference, that the external por- tions of the whirling zone being pressed by the centrifugal force against other portions of the same fluid, the one will conflict with the other, so as to cause the velocity to be com- municated and to lessen outwards from the zone (in which the moving power is or has been applied) till it becomes insensi- ble. This result must ensue the more speedily, since the mo- mentum I'eceives no reinforcement, while the mass which it actuates increases with the square of the distance from the axis. 83. It follows that at any station over which, or near which the centre of a whirlwind shall pass, there will be a breeze scarcely perceptible at first, but which will strengthen gra- dually into a gale of pre-eminent fury. Subsequently a declen- sion must take place until the centre arrives; here again there would be no perceptible wind. The centre having moved away, the wind must increase again to a maximum of force and then decline to a breeze. Redfield's Theory of Storms. 101 84. Mr. Redfiekl alleges, that the storm of August 17th, 1830, whirling to the left, travelled from south-west to north- east at the rate nearly of twenty-seven miles per hour ; that its greatest diameter was from five hundred to six hundred miles ; that of its severe part was from one hundred and fifty to two hundred and fifty miles. Thus it may be assumed, that in order for an observer to be exposed successively within the severe portion on the south-eastern and north-western limbs, the storm would have had to move at least one hun- dred miles, requiring nearly four hours. Hence if the storm in question were a whirlwind, instead of the change having been sudden, several hours would have been required for its gradual accomplishment. 85. To prove therefore that a sudden change ensued from one violent wind to another of the same character blowing in an opposite direction, is to demonstrate that the storm in which it took place was not an extensive whirlwind. Yet this cha- racteristic is universally admitted to belong to hurricanes, and especially to those upon our territory in which a south-easter is followed by a north-wester. Hence the seaman's saying which Mr. Redfield sanctions in quoting, " a north-wester does not remain long in debt to a south-easter." 86. But if the storm above alluded to moved from south- west to north-east as Mr. Redfield's doctrine requires, and the velocity of the wind on the south-eastern and north-western limbs of the whirl were as great as described, that on the south-western side must have been more than a fourth more violent, having the general motion of the storm superadded to its appropriate gyrating velocity. Yet there is no evidence that any such superiority existed. On the contrary, the vio- lence of the south-easter and north-wester seems to have been pre-eminently the object of attention. 87. Agreeably to Mr. Redfield, hurricanes have a diameter varying from one mile to five hundred miles, the diameter of the severe part of the storm of August 1830, being from one hundred and fifty to two hundred and fifty miles. Of course a portion of the eastern as well as the western limb of such a storm might be comprised between the Alleghany moun- tains and the Atlantic shore; and in no case would the inner portion of the south-eastern and more violent limb be beyond the cognizance of our merchants and insurers. It would be a matter of course that in every violent north-east gale, arising as represented from the progression of the north-western limb along our coast, fears would be entertained lest vessels, inward- bound, should be met by a much more violent south-wester. But experience shows, that every north-easter brings in a 102 Dr. Hare's Additional Objections to crowd of vessels having only to complain of the violence, not of the direction of the wind. 88. It has been assumed, that a storm whirling to the left and travelling north-easterly, must, at stations passing nearly under the centre, first blow as a south-easter and afterwards gradually change to a north-wester. Meanwhile on the south- eastern or left limb it will blow only from the south-west, and on the north-western or right limb it will blow only from the north-west. Consistently, when the storm travels from south- east to north-west, as hurricanes are represented to travel in proceeding from the sphere of their origin in the West Indies to the coast of North America, it will at stations within a cer- tain distance of a line described by the centre, blow from the north-east first. On the south-western limb it will blow first as a north-wester ; on the north-eastern limb as a south-easter. Moreover, that on the last-mentioned limb the greatest vio- lence will occur, since the general motion of the whirlwind will there cooperate with that of the whirl. Yet in the fol- lowing paragraph Mr. Redfield informs us (Silliman's Journal, vol. xxv. p. 128), that " in the West Indies hurricanes begin to blow from a northern quarter of the horizon, and then changing to west and round to a southern quarter and then their fury is over." 89. This account of the direction of the wind in West India hurricanes agrees with that quoted by Espy from Edwards's History of Jamaica, vol. iii. : " All hurricanes begin from the north, veer back to west-north-west, west, and south-south- west, and when got to south-east, the foul weather breaks up." 90. It must be evident, as stated among my " objections," that when a whirl is first originated, whether it describe a helix, as would result from its progressive circular motion, or a circle, as represented by Mr. Redfield in his charts*, it must at thirty-two stations equidistant from each other and the centre of gyration, blow from as many points of the com- pass. However, when once under way, it being granted that the whirling is always from right to left, evidently at any sta- tion near the line described by the centre, it will begin to blow at right angles to that line or from the north-east. As the centre advances this wind would gradually subside, and, after the centre should have gone by, it would begin to blow from the south-west with increasing force till the severe part of the south- eastern limb should be passed. On this part of the track only one change would take place. But at two stations sufficiently remote from the central line, the wind in passing from north- * Franklin Journal, vol. xix. p. 120. Redfield's Theory of Storms* 103 east to south-east would undergo an intermediate deviation, but necessarily of an opposite nature, since for the same rea- son that at one there would be first more northing and then more westing, at the other there would be more easting and more southing, pari passu. But on the outward north-eastern and north-western limbs, or in other words, on the right and on the left external borders, there would be no change. On the one it would blow from the north-west only, on the other only from the south-east. On this last-mentioned limb the blast would be pre-eminent in violence, since in that direction the gyrative and progressive motion of the whirlwind would concur. 91. Nevertheless, agreeably to the observations which have lifted the whirlwind theory above the reach of my strictures, hurricanes in the West Indies begin (at every place) from a northern quarter, and changing first west, and afterwards to a southern quarter, terminate their fury. Thus, agreeably to the evidence of Mr. Redfield, the fury of the hurricane is the least where, according to his hypothesis, it should be the greatest. 92. Having cited and endeavoured to show the futility of the only explanation which can be' found in Mr. Redfield's essays of the mode in which whirlwinds are induced, I will quote a passage from which it would seem that they are sup- posed capable of being self-induced. Whence it would follow, that without any extraneous aid, his "rotary movement, which is the sole cause of destructive winds and tempests," could spontaneously excite itself and the adjoining elements into a destructive commotion. From this statement, it appears that the author was not aware that in making it he gave a blow to his favourite idea of opposing and unequal forces, arising from gravitation and terrestrial motion, being the cause of stormy atmospheric gyration. 93. " We may observe, also, that whirlwinds and spouts appear to commence gradually and to acquire their full ac- tivity without the aid of any foreign causes; and it is well known they are most frequent in those calm regions where apparently there are no active currents to meet each other, and they are least frequent where currents are in full activity." (Silliman's Journal, vol. xxxiii. p. 61.) 94. Treating of whirlwinds excited by fire, the author thus expresses himself: — " The foregoing results can only be ex- plained by a violent vortical action steadily maintained. * * * The ascending power of the vortical column or whirlwind is strongly exhibited. * * * But the spire of a columnar vortex exhibits a penetrating and ascending power which far exceeds, both in its intensity and the extent of its action, any other as- 104 Dr. Hare's Additional Objections to cending movement that we witness. This effect appears to be owing to the spiral motion of the column which presses onward in the direction of its axis, till it reaches a limit of elevation yet unknown." (Silliman's Journal, vol. xxxvi. p. 56.) Would it not be as reasonable to expect the spiral of iron usually employed to open bottles, spontaneously to penetrate a cork without being actuated by the operator's hand, as that the aerial spiral, which agreeably to the description above given, constitutes a tornado, should, " without any foreign aid," " or any currents to meet each other," be endowed with the force which he has described ? Admitting the storm-producing efficacy of a collision between trade winds and islands, ad- mitting that gravitation, and rotary and orbitual force are to be substituted for all other agency, how are those causes to extend influence to his aerial isolated spiral, so as to beget the wonderful vortical force portrayed ? 95. I do not deem it expedient to enter upon any discussion as to the competency of the evidence by which the gyration of storms has been considered as proved. By Mr. Espy that has been ably contested. I have given some reasons for doubting the accuracy or consistency of Mr. Redfield's repre- sentations, though I have no doubt they have always been made in perfect good faith. I have already alleged, that were gyration sufficiently proved, I should consider it as an effect of a conflux to supply an upward current at the axis. Yet the survey of the New Brunswick tornado, made on terra firma with the aid of a compass, by an observer so skilful and un- biassed as Professor Bache, ought to outweigh maritime ob- servations, made in many cases under circumstances of diffi- culty and danger. In like manner great credit should be given to the observations collected by Professor Loomis re- specting a remarkable inland storm of December 1836. This storm commenced blowing between south and east to the west- ward of the Mississippi, and travelled from west or north-west to east or south-east at a rate of between thirty and forty miles per hour. There appears to have been within the sphere of its violence an area, throughout which the barometric column stood at a minimum, and towards which the wind blew vio- lently on the one side only from between east and south, and on the other only between north and west. This area extended from south-west to north-east more than two thousand miles. Its great length in proportion to its breadth seems irrecon- cilable with its having formed the axis of a whirlwind. The course of this storm, as above stated, was at right angles to that attributed by Red field to storms of this kind. (Trans. of the American Phil. Society, vol. vii.) Redfield's Theory of Storms. 105 96. Having said so much against the whirlwind theory of storms, it may be expected that I should, on this occasion, say something respecting the opinions which I entertain of their origin. To a certain extent this will be found in my com- munications published in Silliman's Journal, vol. xxxii. p. 153, vol. xl. p. 137, also in my Essay on the Gales of the United States. I still believe our north-eastern gales were correctly represented in the last-mentioned essay as arising from an ex- change of position made between the air of the Gulf of Mexico and that of the territory of the United States which lies to the north-east of that great estuary; and that the heat given out during the conversion of aqueous vapour into rain, by imparting to the atmosphere as much caloric as could be yielded by twice its weight of red-hot sand, is a great instrument in the production of the phenomena; also, that the cold resulting from rarefaction is a cause of the condensation of that vapour, and of course of clouds. On this last idea, derived from Dalton, Mr. Espy has founded his ingenious theory of storms; alleging, erroneously, as I think, the buoyancy, resulting from the heat thus evolved, to be the grand cause of rain, also of tornadoes, hurricanes, and other electrical storms. In the essay above mentioned, I erred in ascribing too much to vari- ations of density arising from changes of elevation, and twenty years' additional experience as an experimenter in electricity, has taught me to ascribe vastly more to this agent than I did formerly. 97. In November last, I verified a conjecture of my friend Dr. J. K. Mitchell, that moist, foggy or cloudy air is not a conductor of electricity, its influence, in paralyzing the efficacy of electrical apparatus, arising from moisture deposited on adjoining solid surfaces. 98. A red-hot iron cylinder, upon which evidently no moisture could be deposited, suspended from the excited con- ductor of an electrical machine, was found to yield sparks within a receiver replete with aqueous vapour, arising from a capsule of boiling water. 99. Hence it appears that bodies of air, whether cloudy or clear, may be oppositely electrified from each other or from the earth. This would explain the gyration on a horizontal axis which seems to be attendant on thunder gusts, and may account for the ascent of the south-easter and descent of the north-wester in the great storm of December 1836, described by Professor Loom is. 100. Such gyration may be a form of convective discharge, in which electrical reaction is assisted by calorific circulation and the evolution of latent heat, agreeably to Dalton and Espy. 106 Dr. Pring on Etching by Electricity. 101. Squalls may be the consequence of electrical reaction between the terrestrial surface and oppositely excited masses of air, and the intermixture of masses so excited in obedience to the same cause, may be among the sources of rain, hail, and gusts. The specific gravity of a body of air, electrified differently from the surrounding medium, may be lessened by what is called electric repulsion ; the particles inevitably moving a greater distance from each other, as similarly elec- trified pith-balls are known to do. 102. Hence a cause of rarefaction, buoyancy, and conse- quent upward motion, in a column of electrified air, more competent than that suggested by Espy. 103. Should it be verified that a gyration from right to left takes place during convective discharges of electricity in hur- ricanes, it may be referrible to the disposition which a positive electrical discharge from the earth to the sky would have to gyrate in that direction. I have prepared some strictures on Dove's Essay on the Law of Storms, which will be the subject of a future communi- cation. XVI. On a Method of Etching on Hardened Steel Plates and other Polished Metallic Surfaces by means of Electricity. By J. H. Pring, M.D. To the Editor of the Philosophical Magazine and Journal. Sjr, 1 HEREWITH transmit to you a rough specimen of what I conceive to be a novel employment of the power of elec- tricity, and shall be gratified should the process by which it was effected prove susceptible of any useful application to the arts. The method which I employed in the production of the characters on the accompanying plate * was the following : — Having six batteries of the kind invented by Mr. Smee, the platinized silver plate of each being about three inches square, I attached the steel plate to be etched upon to the zinc ex- tremity of the batteries, a coil of covered wire, of considerable length, being previously interposed between the steel plate and the zinc: then taking the wire connected with the plati- nized silver in my hand, I used it as an etching-tool on the steel plate, — an electrical spark of great brilliancy, accom- * This was a steel plate, on which the words M Etched by means of Electricity. Bath, 30th June 1843. I. H. P." together with some orna- mental devices, had been produced by the above method. It gave only a faint, just legible impression by the copper-plate press. — Edit. Dr. Pring on Etching by Electricity. 107 panied by a slight indentation on the steel, was the result of each contact of the wire with the plate. The wire by which the etching was made was of platina; the part at which it was held was carried through a glass tube for the purposes of affording a more convenient handle, and of protecting the hand from shocks to which it might other- wise have been exposed. By using the wire connected with the zinc of the batteries as the etching-tool, and attaching the steel plate to the plati- nized silver, a very different effect is produced. With the apparatus thus arranged, the spark that results from the con- tact of the wire with the steel plate is accompanied by a depo- sition of a minute portion of the substance of the wire on the steel; by using different wires, therefore, as of gold, silver, platina, &c, a variety of ornamental designs may probably be formed on polished steel surfaces. The effect of the electrical agency here described is not however confined to steel ; a somewhat similar one may be obtained by substituting plates of other metals. By augment- ing the quantity and intensity of the electrical current, it seems probable that the effect on the steel, or other metals, would be proportionally increased ; and it may be anticipated that, by other modifications of the process, its applications may be advantageously extended. I remain, Sir, yours respectfully, Bath, July 5, 1843. James Hurly Pbing, M.D. The accompanying sketch, in which the apparatus is re- presented lying ready for use, may perhaps serve to illustrate the foregoing description. A. The steel, or other metallic plate to be etched upon. B. The etching point of platina wire projecting from the glass handle. C. The coil of covered wire. D. The batteries. A t 108 ] XVII. — Series of Propositions for rendering the Nomenclature of Zoology uniform and permanent, being the Report of a Committee for the consideration of the subject appointed by the British Asso- ciation for the Advancement of Science*. LL persons who are conversant with the present state of Zoology must be aware of the great detriment which the science sustains from the vague- ness and uncertainty of its nomenclature. We do not here refer to those di- versities of language which arise from the various methods of classification adopted by different authors, and which are unavoidable in the present state of our knowledge. So long as naturalists differ in the views which they are disposed to take of the natural affinities of animals there will always be di- versities of classification, and the only way to arrive at the true system of nature is to allow perfect liberty to systematists in this respect. But the evil complained of is of a different character. It consists in this, that when naturalists are agreed as to the characters and limits of an individual group or species, they still disagree in the appellations by which they distinguish it. A genus is often designated by three or four, and a species by twice that number of precisely equivalent synonyms ; and in the absence of any rule on the subject, the naturalist is wholly at a loss what nomenclature to adopt. The consequence is, that the so-called commonwealth of science is becoming daily divided into independent states, kept asunder by diversities of language as well as by geographical limits. If an English zoologist, for example, visits the museums and converses with the professors of France, he finds that their scientific language is almost as foreign to him as their vernacular. Almost every specimen which he examines is labeled by a title which is unknown to him, and he feels that nothing short of a continued residence in that country can make him conversant with her science. If he proceeds thence to Germany or Russia, he is again at a loss : bewildered everywhere amidst the confusion of nomenclature, he returns in despair to his own country and to the museums and books to which he is accustomed. If these diversities of scientific language were as deeply rooted as the ver- nacular tongue of each country, it would of course be hopeless to think of remedying them ; but happily this is not the case. The language of science is in the mouths of comparatively few, and these few, though scattered over di- stant lands, are in habits of frequent and friendly intercourse with each other. All that is wanted then is, that some plain and simple regulations, founded on justice and sound reason, should be drawn up by a competent body of persons, and then be extensively distributed throughout the zoological world. The undivided attention of chemists, of astronomers, of anatomists, of mineralogists, has been of late years devoted to fixing their respective lan- * From the Report, of the Association for 1842, p. 105. The Committee appointed by the Council, Feb. 11, 1842, consisted of the following members: — Mr. Darwin, Prof. Henslow, Rev. L. Jenyns, Mr. Ogilby, Mr. J. Phillips, Dr. Richardson, Mr. H. E. Strickland (reporter), and Mr. Westwood : to whom were subsequently added Messrs. Broderip, Prof. Owen, Shuckard, Waterhouse and Yarrell. The Report states that an outline of the proposed rules having been drawn up, copies were sent to emi- nent zoologists at home and abroad, with a request that they would favour the Com- mittee with their comments ; and that many valuable suggestions had already been thus obtained. — Ed. Propositions relative to the Nomenclature of Zoology. 109 guages on a sound basis. Why, then, do zoologists hesitate in performing the same duty ? at a time, too, when all acknowledge the evils of the present anarchical state of their science. It is needless to inquire far into the causes of the present confusion of zoological nomenclature. It is in great measure the result of the same branch of science having been followed in distant countries by persons who were either unavoidably ignorant of each other's labours, or who neglected to in- form themselves sufficiently of the state of the science in other regions. And when we remark the great obstacles which now exist to the circulation of books beyond the conventional limits of the states in which they happen to be published, it must be admitted that this ignorance of the writings of others, however unfortunate, is yet in great measure pardonable. But there is another source for this evil, which is far less excusable, — the practice of gratifying individual vanity by attempting on the most frivolous pretexts to cancel the terms established by original discoverers, and to substitute a new and un- authorized nomenclature in their place. One author lays down as a rule, that no specific names should be derived from geographical sources, and un- hesitatingly proceeds to insert words of his own in all such cases ; another declares war against names of exotic origin, foreign to the Greek and Latin ; a third excommunicates all words which exceed a certain number of sylla- bles ; a fourth cancels all names which are complimentary of individuals, and so on, till universality and permanence, the two great essentials of scientific language, are utterly destroyed. It is surely, then, an object well worthy the attention of the Zoological Section of the British Association for the Advancement of Science, to devise some means which may lessen the extent of this evil, if not wholly put an end to it. The best method of making the attempt seems to be, to entrust to a carefully selected committee the preparation of a series of rules, the adoption of which must be left to the sound sense of naturalists in general. By emanating from the British Association, it is hoped that the proposed rules will be invested with an authority which no individual zoologist, how- ever eminent, could confer on them. The world of science is no longer a monarchy, obedient to the ordinances, however just, of an Aristotle or a Lin- naeus. She has now assumed the form of a republic, and although this revo- lution may have increased the vigour and zeal of her followers, yet it has de- stroyed much of her former order and regularity of government. The latter can only be restored by framing such laws as shall be based in reason and sanctioned by the approval of men of science ; and it is to the preparation of these laws that the Zoological Section of the Association have been invited to give their aid. In venturing to propose these rules for the guidance of all classes of zoolo- gists in all countries, we disclaim any intention of dictating to men of science the course which they may see fit to pursue. It must of course be always at the option of authors to adhere to or depart from these principles, but we offer them to the candid consideration of zoologists, in the hope that they may lead to sufficient uniformity of method in future to rescue the science from becoming a mere chaos of words. We now proceed to develope the details of our plan ; and in order to make the reasons by which we are guided apparent to naturalists at large, it will be requisite to append to each proposition a short explanation of the circum- stances which call for it. 110 Propositions for rendering the Nomenclature of Among the numerous rules for nomenclature which have been proposed by naturalists, there are many which, though excellent in themselves, it is not now desirable to enforce*. The cases in which those rules have been over- looked or departed from, are so numerous and of such long standing, that to carry these regulations into effect would undermine the edifice of zoological nomenclature. But while we do not adopt these propositions as authoritative laws, they may still be consulted with advantage in making such additions to the language of zoology as are required by the progress of the science. By adhering to sound principles of philology, we may avoid errors in future, even when it is too late to remedy the past, and the language of science will thus eventually assume an aspect of more classic purity than it now presents. Our subject hence divides itself into two parts ; the first consisting of Rules for the rectification of the present zoological nomenclature, and the second of Recommendations for the improvement of zoological nomenclature in future. PART I. RULES FOR RECTIFYING THE PRESENT NOMENCLATURE. [Limitation of the Plan to Systematic Nomenclature.^ In proposing a measure for the establishment of a permanent and universal zoological nomenclature, it must be premised that we refer solely to the Latin or systematic language of zoology. We have nothing to do with vernacular appellations. One great cause of the neglect and corruption which prevails in the scientific nomenclature of zoology, has been the frequent and often exclusive use of vernacular names in lieu of the Latin binomial designations, which form the only legitimate language of systematic zoology. Let us then endeavour to render perfect the Latin or Linnsean method of' nomenclature, which, being far removed from the scope of national vanities and modern antipathies, holds out the only hope of introducing into zoology that grand desideratum, an universal language. \_Law of Priority the only effectual and just oiie.~\ It being admitted on all hands that words are only the conventional signs of ideas, it is evident that language can only attain its end effectually by being permanently established and generally recognized. This consideration ought, it would seem, to have checked those who are continually attempting to subvert the established language of zoology by substituting terms of their own coinage. But, forgetting the true nature of language, they persist in confounding the name of a species or group with its definition ; and because the former often falls short of the fullness of expression found in the latter, they cancel it without hesitation, and introduce some new term which ap- pears to them more characteristic, but which is utterly unknown to the science, and is therefore devoid of all authority-)-. If these persons were to object to such names of men as Long, Little, Armstrong, Golightly, &c, in cases where they fail to apply to the individuals who bear them, or should complain of the names Gough, Lawrence, or Harvey, that they were devoid of meaning, and should hence propose to change them for more characteristic appella- * See especially the admirable code proposed in the ' Philosophia Botanica' of Linnasus. If zoologists had paid more attention to the principles of that code, the present attempt at reform would perhaps have been unnecessary. f Linnaeus says on this subject, " Abstinendum ah hac innovatione qua: nuncpiam cessa- ret, quin indies aptiora detegerentur ad infinitum." Zoology uniform and permanent. Ill tlons, they would not act more unphilosophically or inconsiderately than they do in the case before us ; for, in truth, it matters not in the least by what conventional sound we agree to designate an individual object, provided the sign to be employed be stamped with such an authority as will suffice to make it pass current. Now in zoology no one person can subsequently claim an authority equal to that possessed by the person who is the first to define a new genus or describe a new species ; and hence it is that the name origin- ally given, even though it may be inferior in point of elegance or express- iveness to those subsequently proposed, ought as a general principle to be permanently retained. To this consideration we ought to add the injustice of erasing the name originally selected by the person to whose labours we owe our first knowledge of the object ; and we should reflect how much the permission of such a practice opens a door to obscure pretenders for dragging themselves into notice at the expense of original observers. Neither can an author be permitted to alter a name which he himself has once published, except in accordance with fixed and equitable laws. It is well observed by Decandolle, " L'auteur meme qui a le premier etabli un nom n'a pas plus qu'un autre le droit de le changer pour simple cause d'impropriete. La pri- orite en effet est un terme fixe, positif, qui n'admet rien, ni d'arbitraire, ni de partial." For these reasons, we have no hesitation in adopting as our fundamental maxim, the " law of priority," viz. § 1. The name originally given by the founder of a group or the describer of a species should be permanently retained, to the exclu- sion of all subsequent synonyms (with the exceptions about to be noticed). Having laid down this principle, we must next inquire into the limitations which are found necessary in carrying it into practice. [Not to extend to authors older than Linnceus.~\ As our subject matter is strictly confined to the binomial system of nomen- clature, or that which indicates species by means of two Latin words, the one generic, the other specific, and as this invaluable method originated solely with Linnaeus, it is clear that, as far as species are concerned, we ought not to attempt to carry back the principle of priority beyond the date of the 12th edition of the ' Systema Naturae.' Previous to that period, naturalists were wont to indicate species not by a name comprised in one word, but by a definition which occupied a sentence, the extreme verbosity of which method was productive of great inconvenience. It is true that one word sometimes sufficed for the definition of a species, but these rare cases were only binomial by accident and not by principle, and ought not therefore in any instance to supersede the binomial designations imposed by Linnaeus. The same reasons apply also to generic names. Linnaeus was the first to attach a definite value to genera, and to give them a systematic character by means of exact definitions; and therefore although the names used by pre- vious authors may often be applied with propriety to modern genera, yet in such cases they acquire a new meaning, and should be quoted on the author- ity of the first person who used them in this secondary sense. It is true, that several of the old authors made occasional approaches to the Linnaean exactness of generic definition, but still these were but partial attempts ; and it is certain that if in" our rectification of the binomial nomenclature we once 112 Propositions for rendering the Nomenclature of trace back our authorities into the obscurity which preceded the epoch of its foundation, we shall find no resting-place or fixed boundary for our re- searches. The nomenclature of Ray is chiefly derived from that of Gesner and Aldrovandus, and from these authors we might proceed backward to iElian, Pliny, and Aristotle, till our zoological studies would be frittered away amid the refinements of classical learning*. We therefore recommend the adoption of the following proposition : — § 2. The binomial nomenclature having originated with Linnaeus, the law of priority, in respect of that nomenclature, is not to extend to the writings of antecedent authors. [It should be here explained, that Brisson, who was a contemporary of Linnaeus and acquainted with the ' Systcma Naturae,' defined and published certain genera of birds which are additional to those in the 12th edition of Linnams's work, and which are therefore of perfectly good authority. But Brisson still adhered to the old mode of designating species by a sentence instead of a word, and therefore while we retain his defined genera, we do not extend the same indulgence to the titles of his species, even when the latter are accidentally binomial in form. For instance, the Perdix rubra of Brisson is the Tetrao rufus of Linnaeus ; therefore as we in this case retain the generic name of Brisson and the specific name of Linnaeus, the correct title of the species would be Perdix rufa.~] £ Generic names not to be cancelled in subsequent subdivisions. .] As the number of known species which form the groundwork of zoological science is always increasing, and our knowledge of their structure becomes more complete, fresh generalizations continually occur to the natui'alist, and the number of genera and other groups requiring appellations is ever be- coming more extensive. It thus becomes necessary to subdivide the contents of old groups and to make their definitions continually more restricted. In carrying out this process, it is an act of justice to the original author, that his generic name should never be lost sight of ; and it is no less essential to the welfare of the science, that all which is sound in its nomenclature should remain unaltered amid the additions which are continually being made to it. On this ground we recommend the adoption of the following rule : — § 3. A generic name when once established should never be can- celled in any subsequent subdivision of the group, but retained in a restricted sense for one of the constituent portions. [^Generic names to be retained for the typical portion of the old genus."} When a genus is subdivided into other genera, the original name should be retained for that portion of it which exhibits in the greatest degree its essential characters as at first defined. . Authors frequently indicate this by selecting some one species as a fixed point of reference, which they term the " type of the genus." When they omit doing so, it may still in many cases be correctly inferred that ilwfrst species mentioned on their list, if found accurately to agree with their definition, was regarded by them as the type. A specific name or its synonyms will also often serve to point out the parti- cular species which by implication must be regarded as the original type of a genus. In such cases we are justified in restoring the name of the old genus * " Quis longo sevo recepta vocabula commutaret hodie cum patrum ? " — Linnceus. Zoology uniform and permanent. 113 to its typical signification, even when later authors have done otherwise. We submit therefore that § 4. The generic name should always be retained for that portion of the original genus which was considered typical by the author. Example. — The genus Picummis was established by Temminck, and in- cluded two groups, one with four toes, the other with three, the former of which was regarded by the author as typical. Svvainson, however, in raising these groups at a later period to the rank of genera, gave a new name, Asthenurus, to the former group, and retained Picummis for the latter. In this case we have no choice but to restore the name Picumnus, Tern., to its correct sense, cancelling the name Asthenurus, Sw., and imposing a new name on the 3-toed group which Svvainson had called Picumnus. [ When no type is indicated, then the original name is to he kept for that sub" sequent subdivision which first received it.'] Our next proposition seems to require no explanation : — § 5. When the evidence as to the original type of a genus is not perfectly clear and indisputable, then the person who first subdivides the genus may affix the original name to any portion of it at his dis- cretion, and no later author has a right to transfer that name to any other part of the original genus. [_A later name of the same extent as an earlier to be wholly cancelled.'} When an author infringes the law of priority by giving a new name to a genus which has been properly defined and named already, the only penalty which can be attached to this act of negligence or injustice, is to expel the name so introduced from the pale of the science. It is not right then in such cases to restrict the meaning of the later name so that it may stand side by side with the earlier one, as has sometimes been done. For instance, the genus Monaulus, Vieill. 1816, is a precise equivalent to Lophophorus, Tern. 1813, both authors having adopted the same species as their type, and there- fore when the latter genus came in the course of time to be divided into two, it was incorrect to give the condemned name Monaulus to one of the por- tions. To state this succinctly, § 6. When two authors define and name the same genus, both making it exactly of the same extent, the later name should be can- celled in loto, and not retained in a modified sense*. This rule admits of the following exception : — § 7» Provided however, that if these authors select their respective types from different sections of the genus, and these sections be after- wards raised into genera, then both these names may be retained in a restricted sense for the new genera respectively. Example. — The names (Edemia and Melanetta, were originally co-exten- sive synonyms, but their respective types were taken from different sections which are now raised into genera, distinguished by the above titles. [No special rule is required for the cases in which the later of two generic * These discarded names may however be tolerated, if they have been afterwards pro- posed in a totally new sense, though we trust that in future no one will knowingly apply an old name, whether now adopted or not, to a new genus. (See proposition q, infra.) Phil. Mag. S. 3. Vol. 23. No. 1 50. Aug. 1843. I 114 Propositions for rendering the Nomenclature of names is so defined as to be less extensive in signification than the earlier, for if the later includes the type of the earlier genus, it would be cancelled by the operation of § 4? ; and if it does not include that type, it is in fact a distinct genus.] But when the later name is more extensive than the earlier, the following rule comes into operation : — [^4 later name equivalent to several earlier ones is to be cancelled.^} The same principle which is involved in § 6, will apply to § 8. § 8. If the later name be so defined as to be equal in extent to two or more previously published genera, it must be cancelled in toto. Example. — Psarocolius, Wagl. 1827> is equivalent to five or six genera previously published under other names, therefore Psarocolius should be cancelled. If these previously published genera be separately adopted (as is the case with the equivalents of Psarocolius), their original names will of course pre- vail; but if we follow the later author in combining them into one, the fol- lowing rule is necessary : — \_A genus compounded of two or more previously proposed genera whose cha- racters are now deemed insufficient, should retain the name of one of ihem.~\ It sometimes happens that the progress of science requires two or more genera, founded on insufficient or erroneous characters, to be combined to- gether into one. In such cases the law of priority forbids us to cancel all the original names and impose a new one on this compound genus. We must therefore select some one species as a type or example, and give the generic name which it formerly bore to the whole group now formed. If these ori- ginal generic names differ in date, the oldest one should be the one adopted. § 9. In compounding a genus out of several smaller ones, the earli- est of them, if otherwise unobjectionable, should be selected, and its former generic name be extended over the new genus so compounded. Example. — The genera Accentor and Prunella of Vieillot not being con- sidered sufficiently distinct in character, are now united under the general name of Accentor, that being the earliest. So also Cerithium and Potamides, which were long considered distinct, are now united, and the latter name merges into the former. We now proceed to point out those few cases which form exceptions to the law of priority, and in which it becomes both justifiable and necessary to alter the names originally imposed by authors. \_A name should be changed tvhen previously applied to another group which still retains it.~\ It being essential to the binomial method to indicate objects in natural history by means of two ivords only, without the aid of any further designa- tion, it follows that a generic name should only have one meaning, in other words, that two genera should never bear the same name. For a similar reason, no two species in the same genus should bear the same name. When these cases occur, the later of the two duplicate names should be cancelled, and a new term, or the earliest synonym, if there be any, substituted. When iti s necessary to form new words for this purpose, it is desirable to make them bear some analogy to those which they are destined to supersede, as where the genus of birds, Plectorhynchus, being preoccupied in Ichthyology Zoology uniform and permanent. 115 is changed to Plectorhatnphus. It is, we conceive, the bounden duty of an author when naming a new genus, to ascertain by careful search that the name which he proposes to employ has not been previously adopted in other departments of natural history*. By neglecting this precaution he is liable to have the name altered and his authority superseded by the first subsequent author who may detect the oversight, and for this result, however unfortu- nate, we fear there is no remedy, though such cases would be less frequent if the detectors of these errors would, as an act of courtesy, point them out to the author himself, if living, and leave it to him to correct his own inad- vertencies. This occasional hardship appears to us to be a less evil than to permit the practice of giving the same generic name ad libitum to a multi- plicity of genera. We submit therefore, that § 10. A name should be changed which has before been proposed for some other genus in zoology or botany, or for some other species in the same genus, when still retained for such genus or species. \_A name whose meaning is glaringly false may be changed."] Our next proposition has no other claim for adoption than that of being a concession to human infirmity. If such proper names of places as Covent Garden, Lincoln's Inn Fields, Newcastle, Bridgewater, &c, no longer sug- gest the ideas of gardens, fields, castles, or bridges, but refer the mind with the quickness of thought to the particular localities which they respectively de- signate, there seems no reason why the proper names used in natural history should not equally perform the office of correct indication even when their etymological meaning may be wholly inapplicable to the object which they typify. But we must remember that the language of science has but a limit- ed currency, and hence the words which compose it do not circulate with the same freedom and rapidity as those which belong to every-day life. The attention is consequently liable in scientific studies to be diverted from the contemplation of the thing signified to the etymological meaning of the sign, and hence it is necessary to provide that the latter shall not be such as to propagate actual error. Instances of this kind are indeed very rare, and in some cases, such as that of Monodon, Caprimulgus, Paradisea apoda and Monoculus, they have acquired sufficient currency no longer to cause error, and are therefore retained without change. But when we find a Batrachian reptile named in violation of its true affinities, Mastodonsaurus, a Mexican species termed (through erroneous information of its habitat) Picus cafer, or an olive-coloured one Muscicapa atra, or when a name is derived from an accidental monstrosity, as in Picus semirostris of Linnaeus, and Helix dis- juncta of Turton, we feel justified in cancelling these names, and adopting that synonym which stands next in point of date. At the same time we think it right to remark that this privilege is very liable to abuse, and ought there- fore to be applied only to extreme cases and with great caution. With these limitations we may concede that § 11. A name may be changed when it implies a false proposition which is likely to propagate important errors. [Names not clearly defined may be changed.] Unless a species or group is intelligibly defined when the name is given, it cannot be recognized by others, and the signification of the name is conse- * This laborious and difficult research will in future be greatly facilitated by the very useful work of M. Agassiz, entitled " Nomcnclator Zoologicus." I 2 116 Propositions for rendering the Nomenclature of quently lost. Two things are necessary before a zoological term can acquire any authority, viz. definition and publication. Definition properly implies a distinct exposition of essential characters, and in all cases we conceive this to be indispensable, although some authors maintain that a mere enumeration of the component species, or even of a single type, is sufficient to authenticate a genus. To constitute publication, nothing short of the insertion of the above particulars in a printed book can be held sufficient. Many birds, for instance, in the Paris and other continental museums, shells in the British Museum (in Dr. Leach's time), and fossils in the Scarborough and other public collections, have received MS. names which.will be of no authority until they are published *. Nor can any unpublished descriptions, however exact (such as those of Forster, which are still shut up in a MS. at Berlin), claim any right of priority till published, and then only from the date of their pub- lication. The same rule applies to cases where groups or species are pub- lished, but not defined, as in some museum catalogues, and in Lesson's ' Traite d'Ornithologie,' where many species are enumerated by name, without any description or reference by which they can be identified. Therefore § 12. A name which has never been clearly defined in some pub- lished work should be changed for the earliest name by which the object shall have been so defined. [Specific names, when adopted as generic, must be changed.^ The necessity for the following rule will be best illustrated by an example. The Corvus pyrrhocorax, Linn., was afterwards advanced to a genus under the name of Pyrrhocorax. Temminck adopts this generic name, and also retains the old specific one, so that he terms the species Pyrrhocorax pyr- rhocorax. The inelegance of this method is so great as to demand a change of the specific name, and the species now stands as Pyrrhocorax alpinus, Vieill. We propose therefore that § 13. Anew specific name must be given to a species when its old name has been adopted for a genus which includes that species. N.B. It will be seen, however, below, that we strongly object to the further continuance of this practice of elevating specific names into generic. [Latin orthography to be adhered to.~\ On the subject of orthography it is necessary to lay down one proposition, — § 14. In writing zoological names the rules of Latin orthography must be adhered to. In Latinizing Greek words there are certain rules of orthography known to classical scholars which must never be departed from. For instance, the names which modern authors have written Aipunemia, Zenophasia, poioce- phala, must, according to the laws of etymology, be spelt JEpycnemia, Xeno- phasia and posocephala. In Latinizing modern words the rules of classic usage do not apply, and all that we can do is to give to such terms as clas- sical an appearance as we can, consistently with the preservation of their etymology. In the case of European words whose orthography is fixed, it is best to retain the original form, even though it may include letters and com- binations unknown in Latin. Such words, for instance, as Woodwardi, * These MS. names are in all cases liable to create confusion, and it is therefore much to be desired that the practice of using them should he avoided in future. Zoology uniform and permanent. 117 Knighti, JBullocki, Eschscholtzi, would be quite unintelligible if they were Latinized into Vicdvardi, Cnichti, Bullocci, Essolzi, &c. But words of bar- barous origin, having no fixed orthography, are more pliable, and hence, when adopted into the Latin, they should be rendered as classical in appear- ance as is consistent with the preservation of their original sound. Thus the words Tockus, awsuree, argoondah, kundoo, &c. should, when Latinized, have been written Toccus, ausure, argunda, cundu, &c. Such words ought, in all practicable cases, to have a Latin termination given them, especially if they are used generically. In Latinizing proper names, the simplest rule appears to be to use the ter- mination -us, genitive -i, when the name ends with a consonant, as in the above examples ; and -ius, gen. -ii, when it ends with a vowel, as Latreille, Latreillii, &c. In converting Greek words into Latin the following rules must be attended to:— Greek. ] at becomes ^atin. ae. ei OS >5 terminal, i. us. ov ov 01 becomes »5 um. u. ce. Greek. Latin. d becomes th. 0 »> ph. X n ch. K )} c. yx » nch. vv ng- h. v „ y. When a name has been erroneously written and its orthography has been afterwards amended, we conceive that the authority of the original author should still be retained for the name, and not that of the person who makes the correction. PART II. RECOMMENDATIONS FOR IMPROVING THE NOMENCLATURE IN FUTURE. The above propositions are all which in the present state of the science it appears practicable to invest with the character of laws. We have endeavour- ed to make them as few and simple as possible, in the hope that they may be the more easily comprehended and adopted by naturalists in general. We are aware that a large number of other regulations, some of which are hereafter enumerated, have been proposed and acted upon by various authors who have undertaken the difficult task of legislating on this subject ; but as the enforce- ment of such rules would in many cases undermine the invaluable principle of priority, we do not feel justified in adopting them. At the same time we fully admit that the rules in question are, for the most part, founded on just criticism, and therefore, though we do not allow them to operate retrospec- tively, we are willing to retain them for future guidance. Although it is of the first importance that the principle of priority should be held paramount to all others, yet we are not blind to the desirableness of rendering our sci- entific language palatable to the scholar and the man of taste. Many zoolo- gical terms, which are now marked with the stamp of perpetual currency, are yet so far defective in construction, that our inability to remove them without infringing the law of priority may be a subject of regret. With these terms we cannot interfere, if we adhere to the principles above laid down ; nor is there even any remedy, if authors insist on infringing the rules of good taste by introducing into the science words of the same inelegant or unclassical character in future. But that which cannot be enforced by law may, in some 118 Propositions for rendering the Nomenclature of measure, be effected by persuasion ; and with this view we submit the follow- ing propositions to naturalists, under the title of Recommendations for the improvement of Zoological Nomenclature in future. [ The best names are Latin or Greek characteristic words. ~\ The classical languages being selected for zoology, and words being more easily remembered in proportion as they are expressive, it is self-evident that § A. The best zoological names are those which are derived from the Latin or Greek, and express some distinguishing characteristic of the object to which they are applied. [ Classes of objectionable names.'] It follows from hence that the following classes of words are more or less objectionable in point of taste, though, in the case of genera, it is often neces- sary to use them, from the impossibility of finding characteristic words which have not before been employed for other genera. We will commence with those which appear the least open to objection, such as a. Geographical names. — These words being for the most part adjectives can rarely be used for genera. As designations of species they have been so strongly objected to, that some authors (Wagler, for instance) have gone the length of substituting fresh names wherever they occur ; others (e.g. Swain- son) will only tolerate them where they apply exclusively, as Lepus hiberni- cus, Troglodytes europ&us, &c. We are by no means disposed to go to this length. It is not the less true that the Hirundo javanica is a Javanese bird, even though it may occur in other countries also, and though other species of Hirundo may occur in Java. The utmost that can be urged against such words is, that they do not tell the whole truth. However, as so many authors object to this class of names, it is better to avoid giving them, except where there is reason to believe that the species is chiefly confined to the country whose name it bears. b. Barbarous names. — Some authors protest strongly against the introduc- tion of exotic words into our Latin nomenclature, others defend the practice with equal warmth. We may remark, first, that the practice is not contrary to classical usage, for the Greeks and Romans did occasionally, though with reluctance, introduce barbarous words in a modified form into their respective languages. Secondly, the preservation of the trivial names which animals bear in their native countries is often of great use to the traveller in aiding him to discover and identify speeies. We do not therefore consider, if such words have a Latin termination given to them, that the occasional and judi- cious use of them as scientific terms can be justly objected to. c. Technical names. — All words expressive of trades and professions have been by some writers excluded from zoology, but without sufficient reason. Words of this class, when carefully chosen, often express the peculiar charac- ters and habits of animals in a metaphorical manner, which is highly elegant. We may cite the generic terms Arvicola, Lanius, Pastor, Tyrannus, Regulus, Mimus, Ploceus, &c, as favourable examples of this class of names. d. Mythological or historical names. — When these have no perceptible re- ference or allusion to the characters of the object on which they are conferred, they may be properly regarded as unmeaning and in bad taste. Thus the generic names Lesbia, Leilas, Remus, Corydon, Pasiphae, have been applied to a Humming bird, a Butterfly, a Beetle, a Parrot, and a Crab respectively, Zoology uniform and permanent, 119 without any perceptible association of ideas. But mythological names may sometimes be used as generic with the same propriety as technical ones, in cases where a direct allusion can be traced between the narrated actions of a personage and the observed habits or structure of an animal. Thus when the name Progne is given to a Swallow, Clotho to a Spider, Hydra to a Polyp, Athene to an Owl, Nestor to a grey-headed Parrot, &c, a pleasing and bene- ficial connexion is established between classical literature and physical science. e. Comparative names. — The objections which have been raised to words of this class are not without foundation. The names, no less than the defini- tions of objects, should, where practicable, be drawn from positive and self- evident characters, and not from a comparison with other objects, which may be less known to the reader than the one before him. Specific names express- ive of comparative size are also to be avoided, as they may be rendered in- accurate by the after-discovery of additional species. The names Picoides, Emberizoides, Pseudoluscinia, rubeculoides, maximus, minor, minimus, &c. are examples of this objectionable practice. f. Generic names compounded from other genera.*— These are in some de- gree open to the same imputation as comparative words ; but as they often serve to express the position of a genus as intermediate to, or allied with, two other genera, they may occasionally be used with advantage. Care must be taken not to adopt such compound words as are of too great length, and not to corrupt them in trying to render them shorter. The names Gallopavo, Te- traogallus, Gypaetos, are examples of the appropriate use of compound words. g. Specific names derived from persons. — So long as these complimentary designations are used with moderation, and are restricted to persons of emi- nence as scientific zoologists, they may be employed with propriety in cases where expressive or characteristic words are not to be found. But we fully concur with those who censure the practice of naming species after persons of no scientific reputation, as curiosity dealers (e. g. Caniveti, Boissoneauti), Peruvian priestesses (Cora, Amazilia), or Hottentots (Klassi). h. Generic names derived from persons. — • Words of this class have been very extensively used in botany, and therefore it would have been well to have excluded them wholly from zoology, for the sake of obtaining a memo- ria technica by which the name of a genus would at once tell us to which of the kingdoms of nature it belonged. Some few personal generic names have however crept into zoology, as Cuvieria, Mulleria, Rossia, Lessonia, &c, but they are very rare in comparison with those of botany, and it is perhaps de- sirable not to add to their number. i. Names of liar sh and inelegant pronunciation. — These words are grating to the ear, either from inelegance of form, as Huhua, Yuhina, Craxirex, Esch- scholtzi, or from too great length, as chirostrongylostinus, Opeliorhynchus, brachypodioides, Thecodontosaurus, not to mention the Enaliolimnosaurus crocodilocephaloides of a German naturalist. It is needless to enlarge on the advantage of consulting euphony in the construction of our language. As a general rule it may be recommended to avoid introducing words of more than five syllables. k. Ancient names of animals applied in a wrong sense. — It has been cus- tomary, in numerous cases, to apply the names of animals found in classic authors at random to exotic genera or species which were wholly unknown to the ancients. The names Cebus, Callilhrix, Spiza, Kitta, Struthus, are examples. This practice ought by no means to be encouraged. The usual 120 Propositions for rendering the Nomenclature of defence for it is, that it is impossible now to identify the species to which the name was anciently applied. But it is certain that if any traveller will take the trouble to collect the vernacular names used by the modern Greeks and Italians for the Vertebrata and Mollusca of southern Europe, the meaning of the ancient names may in most cases be determined with the greatest preci- sion. It has been well remarked that a Cretan fisher-boy is a far better com- mentator on Aristotle's ' History of Animals' than a British or German scho- lar. The use however of ancient names, when correctly applied, is most de- sirable, for " in framing scientific terms, the appropriation of old words is preferable to the formation of new ones*." /. Adjective generic names. — The names of genera are, in all cases, essen- tially substantive, and hence adjective terms cannot be employed for them without doing violence to grammar. The generic names Jlians, Criniger, Cursorius, Nitidula, &c. are examples of this incorrect usage. m. Hybrid names. — Compound words, whose component parts are taken from two different languages, are great deformities in nomenclature, and na- turalists should be especially guarded not to introduce any more such terms into zoology, which furnishes too many examples of them already. We have them compounded of Greek and Latin, as Dendrofalco, Gymnocorvus, Mo- noculus, Arborophila, fiavigaster ; Greek and French, as Jacamaralcyon, Ja- camerops ; and Greek and English, as Bullochoides, Gilbertsocrinites. n. Names closely resembling other names already used. — By Rule 10 it was laid down, that when a name is introduced which is identical with one pre- viously used, the later one should be changed. Some authors have extended the same principle to cases where the later name, when correctly written, only approaches in form, without wholly coinciding with the earlier. We do not, however, think it advisable to make this law imperative, first, because of the vast extent of our nomenclature, which renders it highly difficult to find a name which shall not bear more or less resemblance in sound to some other ; and, secondly, because of the impossibility of fixing a limit to the degree of approximation beyond which such a law should cease to operate. We con- tent ourselves, therefore, with putting forth this proposition merely as a re- commendation to naturalists, in selecting generic names, to avoid such as too closely approximate words already adopted. So with respect to species, the judicious naturalist will aim at variety of designation, and will not, for ex- ample, call a species virens or virescens in a genus which already possesses a viridis. o. Corrupted words. — In the construction of compound Latin words, there are certain grammatical rules which have been known and acted on for two thousand years, and which a naturalist is bound to acquaint himself Avith be- fore he tries his skill in coining zoological terms. One of the chief of these rules is, that in compounding words all the radical or essential parts of the constituent members must be retained, and no change made except in the variable terminations. But several generic names have been lately introduced which run counter to this rule, and form most unsightly objects to all who are conversant with the spirit of the Latin language. A name made up of the first half of one word and the last half of another, is as deformed a monster in nomenclature as a Mermaid or a Centaur would be in zoology ; yet we find examples in the names Corcorax (from Corvus and Pyrrhocorax), Cypsnagra * Whewell, Phil. Ind. Sc. v. i. p. lxvii. Zoology uniform and permanent. 121 (from Cypselus and Tanagra), Merulaxis (Merula and Synallaxis), Loxigilla (Loxia and Fringilla), &c. In other cases, where the commencement of both the simple words is retained in the compound, a fault is still committed by cutting off too much of the radical and vital portions, as is the case in Bu- corvus (from Buceros and Corvus), Ninox (Nisus and JYoctua), &c. p. Nonsense names. — Some authors having found difficulty in selecting ge- neric names which have not been used before, have adopted the plan of coining words at random without any derivation or meaning whatever. The following are examples : Viralva, Xema, Azeca, Assiminia, Quedius, Spisula. To the same class we may refer anagrams of other generic names, as Dacelo and Ce~ dola of Alccdo, Zapomia of Porzana, &c. Such verbal trifling as this is in very bad taste, and is especially calculated to bring the science into contempt. It finds no precedent in the Augustan age of Latin, but can be compared only to the puerile quibblings of the middle ages. It is contrary to the genius of all languages, which appear never to produce new words by spontaneous ge- neration, but always to derive them from some other source, however distant or obscure. And it is peculiarly annoying to the etymologist, who after seek- ing in vain through the vast storehouses of human language for the parentage of such words, discovers at last that he has been pursuing an ignis fatuus. q. Names previously cancelled by the operation oj § 6. — Some authors con- sider that when a name has been reduced to a synonym by the operations of the laws of priority, they are then at liberty to apply it at pleasure to any new group which may be in want of a name. We consider, however, that when a word has once been proposed in a given sense, and has afterwards sunk into a synonym, it is far better to lay it aside for ever than to run the risk of ma- king confusion by re-issuing it with a new meaning attached. r. Specific names raised into generic. — It has sometimes been the practice in subdividing an old genus to give to the lesser genera so formed, the names of their respective typical species. Our Rule 13 authorizes the forming a new specific name in such cases ; but we further wish to state our objections to the practice altogether. Considering as we do that the original specific names should as far as possible be held sacred, both on the grounds of justice to their authors and of practical convenience to naturalists, we would strongly dissuade from the further continuance of a practice which is gratuitous in itself, and which involves the necessity of altering long-established specific names. We have now pointed out the principal rocks and shoals which lie in the path of the nomenclator ; and it will be seen that the navigation through them is by no means easy. The task of constructing a language which shall supply the demands of scientific accuracy on the one hand, and of literary elegance on the other, is not to be inconsiderately undertaken by unqualified persons. Our nomenclature presents but too many flaws and inelegancies already, and as the stern law of priority forbids their removal, it follows that they must remain as monuments of the bad taste or bad scholarship of their authors to the latest ages in which zoology shall be studied. [Families to end in idee, and Subfamilies in ina?.] The practice suggested in the following proposition has been adopted by many recent authors, and its simplicity and convenience is so great that we strongly recommend its universal use. § B. It is recommended that the assemblages of genera termed fa- milies should be uniformly named by adding the termination idee to 122 Propositions for rendering the Nomenclature of the name of the earliest known, or most typically characterized genus in them ; and that their subdivisions, termed subfamilies, should be similarly constructed, with the termination ince. These words are formed by changing the last syllable of the genitive case into idee or incc, as Strix, Strigis, Slrigidce, Buceros, Bucerotis, Bucerotidce, not StrixidcB, Buceridce. [ Specific names to be written with a small initial.] A convenient memoria technica may be effected by adopting our next pro- position. It has been usual, when the titles of species are derived from pro- per names, to write them with a capital letter, and hence when the specific name is used alone it is liable to be occasionally mistaken for the title of a genus. But if the titles of species were invariably written with a small ini- tial, and those of genera with a capital, the eye would at once distinguish the rank of the group referred to, and a possible source of error would be avoided. It should be further remembered that all species are equal, and should there- fore be written all alike. We suggest, then, that § C. Specific names should ahoays be written with a small initial letter, even when derived from persons or places, and generic names should be always written with a capital. [ Tfie authority for a species, exclusive of the genus, to be followed by a di- stinctive expression.'] The systematic names of zoology being still far from that state of fixity which is the ultimate aim of the science, it is fretpjently necessary for correct indication to append to them the name of the person on whose authority they have been proposed. When the same person is authority both for the specific and generic name, the case is very simple ; but when the specific name of one author is annexed to the generic name of another, some difficulty occurs. For example, the Muscicapa crinita of Linnaeus belongs to the modern genus Tyrannus of Vieillot ; but Swainson was the first to apply the specific name of Linnaeus to the generic one of Vieillot. The question now arises, Whose authority is to be quoted for the name Tyrannus crinitus? The expression Tyrannus crinitus, Lin., would imply what is untrue, for Linnaeus did not use the term Tyrannus ; and Tyrannus crinitus, Vieill., is equally incorrect, for Vieillot did not adopt the name crinitus. If we call it Tyrannus crinitus, Sw., it would imply that Swainson was the first to describe the species, and Linnaeus would be robbed of his due credit. If we term it Tyrannus, Vieill., crinitus, Lin., we use a form which, though expressing the facts correctly, and therefore not without advantage in particular cases where great exactness is required, is yet too lengthy and inconvenient to be used with ease and rapi- dity. Of the three persons concerned with the construction of a binomial title in the case before us, we conceive that the author who first describes and names a species which forms the groundwork of later generalizations, possesses a higher claim to have his name recorded than he who afterwards defines a genus which is found to embrace that species, or who may be the mere accidental means of bringing the generic and specific names into con- tact. By giving the authority for the specific name in preference to all others, the inquirer is referred directly to the original description, habitat, &c. of the species, and is at the same time reminded of the date of its discovery ; while genera, being less numerous than species, may be carried in the memory, or Zoology uniform and permanent. 123 referred to in systematic works without the necessity of perpetually quoting their authorities. The most simple mode then for ordinary use seems to be to append to the original authority for the species, when not applying to the genus also, some distinctive mark, such as (sp.) implying an exclusive refer- ence to the specific name, as Tyrarmus crinitus, Lin. (sp.), and to omit this expression when the same authority attaches to both genus and species, as Ostrea edulis, Lin.* Therefore, § D. It is recommended that the authority for a specific name, when not applying to the generic name also, should be followed by the di- stinctive expression (sp.). [New genera and species to be defined amply and publicly.] A large proportion of the complicated mass of synonyms which has now become the opprobrium of zoology, has originated either from the slovenly and imperfect manner in which species and groups have been originally de- fined, or from their definitions having been inserted in obscure local publica- tions which have never obtained an extensive circulation. Therefore, although under § 12, we have conceded that mere insertion in a printed book is suffi- cient for publication, yet we would strongly advise the authors of new groups always to give in the first instance a full and accurate definition of their cha- racters, and to insert the same in such periodical or other works as are likely to obtain an immediate and extensive circulation. To state this briefly, § E. It is recommended that new genera or species be amply de- fined, and extensively circulated in the first instance. \_The names to be given to subdivisions of genera to agree in gender with tJie original genus.~\ In order to preserve specific names as far as possible in an unaltered form, whatever may be the changes which the genera to which they are referred may undergo, it is desirable, when it can be done with propriety, to make the new subdivisions of genera agree inge?ider with the old groups from which they are formed. This recommendation does not however authorize the changing the gender or termination of a genus already established. In brief, § F. It is recommended that in subdividing an old genus in future, the names given to the subdivisions should agree in gender with that of the original group. [Etymologies and types of new genera to be stated.'} It is obvious that the names of genera would in general be far more care- fully constructed, and their definitions would be rendered more exact, if authors would adopt the following suggestion : — § G. It is recommended that in defining new genera the etymo- logy of the name should be always stated, and that one species should be invariably selected as a type or standard of reference. In concluding this outline of a scheme for the rectification of zoological nomenclature, we have only to remark, that almost the whole of the proposi- tions contained in it may be applied with equal correctness to the sister sci- ence of botany. We have preferred, however, in this essay to limit our views * The expression Tyrarmus crinitus (Lin.) would perhaps be preferable from its greater brevity. 124 Mr. Murchison on the Geological Structure to zoology, both for the sake of rendering the question less complex, and because we conceive that the botanical nomenclature of the present day stands in much less need of distinct enactment than the zoological. The admirable rules laid down by Linnaeus, Smith, Decandolle, and other botanists (to which, no less than to the works of Fabricius, Illiger, Vigors, Swainson, and other zoologists, we have been much indebted in preparing the present document), have always exercised a beneficial influence over their disciples. Hence the language of botany has attained a more perfect and stable con- dition than that of zoology ; and if this attempt at reformation may have the effect of advancing zoological nomenclature beyond its present backward and abnormal state, the wishes of its promoters will be fully attained. (Signed) H. E. Strickland. J. S. Henslow. June 27, 1842. John Phillips. W. E. Shuckard. John Richardson. G. It. Waterhouse. Richard Owen. W. Yarrell. Leonard Jenyns. C. Darwin. W. J. Broderip. J. O. Westwood. XVIII. On the Geological Structure of the Ural Mountains. By Roderick Impey Murchison, Esq., F.R.S.,Pres. G.S., M. E. de Verneuil, and Count A. von Keyserling*. A SHORT introduction explains, that although the true geological relations of the rocks which constitute these mountains were pre- viously little known, the Russians had become well acquainted with their mineral wealth and lithological structure. The skill and energy with which the mines have been worked having been adverted to, the authors dwell with pleasure upon the facilities which the Impe- rial Government afforded them by the instructions conveyed to all the mining establishments by the orders of Count Cancrine and the arrangements of Gen. Tcheffkine. They also acknowledge the advantages they derived from the co-operation of many officers at the different stations or zavods, several of whom prepared maps for their usef. They further express their obligations to many indi- vidual proprietors, and notably to M. Anatole Demidof, and the Prince Butera, for their very hospitable reception at the zavods of Nijny Tagilsk and Bissersk. They then proceed to state, that without the small general map recently published by Baron A. von Humboldt and his associates, the objects of the journey could not have been so well attained. These objects Were, to reunite the various frag- * From the Proceedings of the Geological Society, vol. iii. p. 742 ; being an abstract of a memoir read before the Society on the 18th of May, 1842. On the geology of Russia, see also pres. vol. p. 71, note. f Among these officers allusion in this brief notice can only be made to those in command, viz. Gen. Glinka, Commander-in-chief at Ekaterinburg; Col. Volkncr, formerly at Perm ; Col. Protassof at BogosJofsk, who first ex- plored the districts north of that station ; Col. Tchaikofski of Ekaterinburg, and Col. Galahofski of Turinsk. of the Ural Mountains. 125 ments of the Ural chain, to show of what sedimentary masses it was originally composed, and to explain by what agency the strata have been dislocated and altered. In the latter respect they are aware that their labours have to a great extent been anticipated by the researches of Baron Humboldt, and his companions M. G. Rose and M. Ehrenberg, as well as by their predecessors Colonel Hel- mersenandM. Hoffmann*, and various officers of the Imperial School of Mines f. Moving in two parties and upon separate but parallel lines of re- search, the authors examined both flanks of the chain simultane- ously, their force being brought together at the chief establishments by mutual converging traverses ; and thus, in less than three months, they acquired a general knowledge of the chain from Bogoslofsk on the north to Orsk and Orenburg on the south, a distance of about 550 miles. It is not pretended that this knowledge is precise in re- lation to the mineral structure of the mining tracts ; as such details either have been or will be worked out by Russian engineers. The authors merely hope to have succeeded in giving an unity of geolo- gical composition to the chain, so that the age of the chief masses may be effectively compared with the unaltered deposits of the plains of Russia, and by this means with the geological succession of sedimentary deposits already established in Europe. Physical Features. — Referring to Capt. Strajefski for his account of the northernmost and uncolonized part of the chain, which he ex- plored amid great privations to 65° N. lat., the physical geography of the civilized portion is briefly sketched, and the chief altitudes, as determined by Colonel Helmersen, are given. The general bearing of the chain, as well known, trends from north to south. Ekaterinburg, the chief town, is situated on the eastern side of the only very low depression in the range, from which point this dividing crest between Europe and Asia rises both to the north and south, and attains al- titudes occasionally of 2500 feet. The northern Ural, formerly occupied by Voguls, who still live in the wildernesses north of 61 degrees, is inhospitable in climate, and is chiefly occupied by dense forests, through which the rocks of the central water-shed are per- ceptible only at intervals. This monotony, however, is enlivened by knots of mountains which rise up on the sides of the parting ridge, and overtop it. Such are the Katch Kanar, the Pawdinskoi Kamen, near Bogoslofsk, 2784 English feet, and the Konjakofski Kamen, to the north of the same places, about 5700 feet above the seaj. Whilst the North Ural (or that north of Ekaterinburg) has one per- sistent direction with some lower flanking ridges parallel to the chief * See various works on given districts of the Ural mountains by officers of the Imperial School of Mines. f These works are referred to and ably condensed in a Russian work by Prof. Stsburofski of Moscow. X This mountain was once estimated tobave an altitude of 8000 or 9000 feet, but by the trigonometrical observations of Fedoroff and the barometrical cal- culations of KupfFer, it has been ascertained that it cannot exceed 5280 Paris feet above the sea. It was upon this point of the range that the authors saw much snow in the month of July. 126 Mr. Murchison on the Geological Structure one, the whole not occupying a breadth of more than from 45 to 70 miles, the South Ural, i. e. to the south of the mountain Jurma*, expands to much greater width, branching off into fan-shaped ridges, which trend to the south and to the east and west of that point. In this region, however, as in the north, the water crest or Ural-tau preserves a north and south direction, varying in height from 1800 to 2500 feet, whilst the broken ridges on its western flanks, such as the Taganai near Zlataoust, rise to 3800 English feet, and the Iremel to about 5136 English feet above the sea. From its configuration, and also from its latitude, the South Ural, inhabited by Baschkirs, is infinitely more picturesque than the North Ural ; but, with the exception of the environs of Miask and Zlata- oust, it is much less rich in mines than the North Ural. Geological Structure. — The Ural mountains consist of ancient se- dimentary strata, which, in the central parts of the chain and on its eastern or Siberian flank, are for the most part in a highly metamor- phic condition; also of various rocks of igneous or intrusive origin. Owing to the eruption of the latter at numberless points and along great zones of fissure parallel to the axis of the chain, the ancient deposits are so dismembered and altered, that it is at inter- vals only they can be deciphered. The rocks are described in de- scending order, or from the flanks to the centre of the chain. Carboniferous System. — By examining these mountains from their western slopes, where igneous rocks are comparatively scarce, the authors, in consequence of their knowledge of the palaeozoic strata of western Europe and Russia in Europe, had no great difficulty in reading off the true order of succession on the banks of the Tchus- sovaya, Serebrianka, and other transversely-flowing streams. In the first place, the beds of sandstone, conglomerate and calcareous flags alluded to in the former memoirf are seen to rise from beneath the Permian deposits, and containing in some parts thin courses of coal, and in others coal-plants, Goniatites and certain fossils, re- present the upper members of the carboniferous system. These strata are succeeded by a thick formation of hard quartzose grit and sandstone, very much resembling the millstone grit of some parts of England. Beneath this is the carboniferous or mountain limestone, properly so called', of English geologists, and which is recognised by containing many of the same typical fossils as in En- gland and other parts of Russia. Thus defined, the carboniferous system occupies, on the western side of the chain, a very wide zone, which to the south of Kongur is expanded into a large trough ex- tending beyond the parallel of 55° N. lat., and flanked upon the west and east by upcasts of the limestone, it contains in its centre the great undulations of the grits and conglomerates just spoken of. A third and less prolonged, but most remarkable zone of this limestone appears in four insulated hills extending north and south of Sterlitamak, and perfectly parallel to the chain. It is in the * About 3000 English feet above the son. All these heights are taken from Colonel Helmersen and M. Hoffmann. f See pres. vol. p. 64. of the Ural Mountains. 127 southern prolongation of this line of upheaval that the Permian red sandstones and limestones of Gre-beni and Orenburg are thrown into anticlinal positions, the axis of which is also parallel to that of the adjacent older rocks. For reasons' hereafter adduced, it is in- ferred that this anticlinal was formed subsequent to the chief ele- vation of the chain. Devonian Limestones, fyc. — The Devonian rocks of the North Ural are seen on the banks of the Tchussovaya in the form of limestones, grits and schists, which pass into the lower carboniferous limestone, the latter being always in highly inclined, sometimes in very con- torted and even inverted positions, the younger rocks dipping under the older. These Devonian limestones much resemble, in their dark colour and subcrystalline aspect, those of South Devon in England, and they contain fossils characteristic of this division both in the British Isles, in Belgium, Prussia and the Eifel ; but though perfectly identified both by position and contents with the Devonian rocks of the flat regions of Russia, the Uralian strata are as dissimilar from them in external aspect as the rocks of the same age in Devonshire are from the old red sandstone of the north of Scotland and of Herefordshire or Brecon in England. Nor are these Devonian rocks on the western flanks of the Ural separated from the lower car- boniferous limestone by any band of sandstone and coal as in the northern parts of Russia in Europe, but the grey limestone of the overlying group is at once succeeded by the dark limestone of the other, both undergoing the same flexures, and both forming parts of one great palaeozoic series. In their prolongation to the south, the limestones of this Devo- nian group thin out and inosculate with a considerable development of red sandstone, grit, fine conglomerate and schist, in some parts resembling the old red sandstone of the Highlands. A peculiar mineral character of these Devonian limestones is, that they retain their black colour even when in the state of dolomite. Silurian Hocks. — The schists and flagstones which underlie these limestones are considered to be of Silurian age ; with these strata are associated beds of limestone for the most part concretionary, and which are well developed on the banks of the Serebrianka from the zavod of Serebriansk to near its mouth. Among the predomi- nant fossils of this group and amid numerous corals, the Terebratula prisca (Atrypa qffinis, Sil. Syst.) is clustered together in great masses, as in the Ludlow rocks of England, and with it are associated the remarkable Leptcena Uralensis and other new species. The same descending sequence cannot be.so well seen in many parts of the North Ural, as on the banks of the Serebrianka. Immediately, however, to the east of the water-shed (viz. from Bogoslofsk to Nijny Tagilsk and Neviansk), broken masses of limestone, insulated amid plutonic rocks, are charged with large Pentameri, closely approaching to the Pentamerus/ Knightii of the upper Silurian rocks, and associated with Orthis, Terebratula and other fossils, which, from collections sent to him, M. de Buch has classed as Silurian forms (see Beitriige der Geb. Form, in Russ- 128 Mr. Murchison on the Geological Structure 5' land. Von L. Von Buch. 1840). Although then the clear strati- graphical sequence is interrupted, there is no doubt that the equi- valents, at least of the upper members of the Silurian rocks, exist in these mountains ; and in tracing such into the South Ural, par- ticularly by a transverse section from Verch-Uralsk to Sterlitamak, the authors convinced themselves, from the presence of Orthidse, Pentameri, &c, .that where not much interfered with by intrusive rocks, the central deposits of the chain (usually however in the state of slate and quartz rock) belong to the Silurian system, and probably to its lowest divisions. The symmetry which is developed on the western side of the water-shed is almost obliterated to the east by the greater frequency of eruptive matter and the abundance of metamorphic and metalli- ferous rocks. Thus in passing eastwards into Siberia on any paral- lel, from Bogoslofsk, Nijny Tagilsk, Ekaterinburg, Miask or Verch- Uralsk, no regular succession can be traced ; as large zones of igneous and crystalline rocks intervene, and thus different members of the palaeozoic series are met with upon the same strike. In some spots however, notwithstanding all this confusion, transitions can be traced from lower to higher formations. At Bogoslofsk, for ex- ample, a passage may be observed from Silurian to Devonian strata j and though all the formations are not in apposition to the east of Ekaterinburg, the section of the river Isset clearly shows, that, after various undulations, the Devonian limestones and schists on the west are succeeded on the east by true carboniferous limestone with large Producti, this latter deposit being in some instances based upon conglomerates and grit. Whilst this succession is ex- posed in a region penetrated by many points of eruptive trap and porphyry, the whole of the less altered group reposing on mica- ceous schists and other granitic rocks, a mass of Pentamerus lime- stone is thrown up in an insulated tract at a small distance ; and as this limestone is quite dissimilar from any visible in the* adjacent gorges of the Isset, where the Devonian and carboniferous lime- stones are fully developed, the authors conclude that it belongs to the Silurian epoch. On the eastern flank of the southern Ural the ancient sedimen- tary rocks occur in great undulations. At Troitsk in the steppes of the Kirghis, or beyond a chain of granite separated from and parallel to the Ural (see map), Silurian and Devonian limestones occur, whilst at Cossatchi Datchi, close to the eastern flank of the Ural, there is a small basin of palaeozoic rocks, the limestone of which is proved to be true carboniferous, by containing a vast pro- fusion of fossils, many of which are common to the VValda'i lime- stones of Russia, and the mountain limestone of the British Isles and Belgium. In following southward the eastern slopes of the chain where they border on the river Ural, promontories of carboniferous limestone rise up in undulations, supporting troughs of the coarse carboniferous grits and conglomerates before alluded to; and on passing the axis of the chain between Orsk and Orenburg, where it dwindles to a small height, the same carboniferous group of lime- of the Vial Mountains. 129 stones, conglomerates and grits is thrown off to the west upon the face of the igneous rocks forming the Guberlinsk hills. Jn travelling westwards to Orenburg, particularly from the limestone hills of Gourmaya, the authors found a most instructive section, developing the ascending order from the great carboniferous limestone through the overlying grits, flagstone and calcareous grits with Goniatites, into the beds with gypsum, which form the base of the Permian system, the whole being distinctly overlaid by conformably inclined strata of cupriferous grits, red sandstone, shale and limestones con- taining fossils of the zechstein. Upon the eastern flanks of the Ural, on the contrary, granitic and other igneous rocks rising (as before said) to the surface, that re- gion is entirely void of all those strata which in Russia in Europe are interposed between the carboniferous and Jurassic systems. Beds belonging to the latter system have indeed been detected at two very widely distant localities, the one in 65° N. lat. by Capt. Strajefski, trie other forming a plateau in the southernmost extremity of the chain north of Orsk, where they were first observed by Col. Helmersen*. It must however be observed, that the great mass of the chain is void of Jurassic strata, nor have its eastern flanks afforded any evidences of cretaceous or ter- tiary rocks, as identifiable by organic remains. From this last remark, the authors would except certain grits which occur in patches in the lower country of Siberia, notably at Kaltehedansk, east of Ekaterinburg. These grits, which are largely quarried for millstones, might almost be called " trachytic," as they resemble in composition some of the rough trachytes of Hungary, and like which they pass into an impure pitchstone grit. From the asso- ciated amber and beds of clay, it may however be inferred, that these rocks were formed under water, and that they owe the trachytic aspect to their having resulted from the detritus of the quartzose porphyries on which they repose. They are probably continuous masses of the grits described by G. Rose, near Verkhoturie. Sec- tions on the river Isset explain these phaenomena. Igneous, Metamorphic and Metalliferous Rocks. — As it formed subordinate parts only of the objects of the authors, either to study the details of the metamorphism of the sedimentary strata produced by the intrusion of igneous rocks, or the associated simple minerals, the relations of both of which have been so elaborately described by Mons. G. Rose, this portion of their memoir is chiefly confined to a sketch of some striking phaenomena of this class. No true granite appears in the higher mountains, the syenite which is seen at intervals being intimately allied to greenstone ; and the latter, with its various modifications, is by far the most abundant of the intrusive rocks which appear on or along the immediate flanks of the Ural ridge f. Whenever these greenstones and traps rise to the * The authors did not visit the last-mentioned spot, but, from the com- munication of their friend Colonel Helmersen, they have little doubt that this deposit is a fragment of the Jurassic range which they traced to the south and west of Orenburg. f The granitic region is in Siberia, to the east of the Ural. Phil. Mag. S. 3. Vol. 23. No. 150. Aug. 1843. K 130 Mr. Murchison on the Geological Structure surface, the strata in their proximity are highly altered. Thus even when studied on a small scale on the western flank of the moun- tains, as at the baths of the Zavod of Sergiefsk, the sandstone in contact is altered into quartz rock, and the limestone, so regularly bedded and full of fossils at a little distance, is converted into an amorphous, crystalline, splintery mass, charged with cross veins, and sulphureous saline waters flow from its base, the adjacent rocks being also much impregnated with iron ore. Similar but on a far grander scale are the phenomena of intrusion and metamorphism which are presented by the central axis of the Ural, and to a less extent by all the parallel ridges which flank it on the eastern or Siberian side. The Ural-tau or crest is to a very great extent a wall of schist and quartz rock diversified by points of igneous rocks, and though of no great altitude, it is very remarkable that throughout 17 de- grees of latitude this water-shed is not broken through by any great transverse valley. The Ural-tau marks, in fact, one long line or fissure of eruption. With the exception of the gold mines near Bissersk, on its west flank, all the gold alluvia of the chain occur on its eastern flank ; and when it is stated that this circumstance is connected with the fact, that all the great masses of igneous rocks have been evolved on the eastern flank, it will at once be seen (as insisted upon so well by Humboldt) that there is an intimate con- nexion between the eruption of plutonic rocks and the formation of the gold mines [veins ?] whence the local alluvia have been derived. That this connexion exists in regard to other mineral veins, is also equally apparent in the Ural mountains ; for with very rare excep- tions, it is only on their eastern or eruptive side that copper veins, malachite, platinum and magnetic iron prevail*. Without entering into all the lithological distinctions of the North Ural, they advert specially to the occurrence in the districts of Turinsk and Nijny Tagilsk of a stratified and regularly bedded por- phyry, which they compare with the " Schaalstein" of German geo- logists, and which on the banks of the Kakwa and east of Bogos- lofskf , as in the Rhenish provinces, alternates with limestone strata of Devonian age. In the copper mines of Turinsk, the veins and masses of ore are shown to be intimately connected with the intrusion of greenstone, between a thick mass of which and the metalliferous veins is a garnet rock. This phenomenon is a counterpart to that formerly described by Professor Henslow in the Isle of Anglesea ; whilst on the river Kakwa, the ordinary limestone (Devonian?) has been converted by a dyke of greenstone into white granular marble, in the same way as by the contact of syenite the lias limestone of the Isle of Sky has been changed. The Katch-kanar mountain (lat. 58° 44-'), which the authors vi- sited by a little-frequented pass, is composed of augitic greenstone * In sketching the chief relations of the plutonic and metamorphic rocks of the North Ural, much praise is given to a detailed geological map of the environs of Bogoslofsk by Capt. Karpiuski, of the School of Mines, with a copy of which the authors were furnished. t See Geol. Trans, vol. vi. pp. 246, 248. of the Ural Mountains. 131 and magnetic iron, the latter in so hard and crystalline a state that it is not worthy of extraction and manufacture. The most pro- ductive masses of magnetic iron are at the Government establish- ment of Mount Blagodat, and that of Nijny Tagilsk, belonging to M. Anatole Demidoft'. In both these cases the ordinary varieties of iron occur in great masses, occasionally with chromate of iron*, in contact with rocks of igneous origin, in which serpentine, compact felspar, greenstone, porphyry, &c. are apparent. At Nijny Tagilsk the chief intrusive rock (greenstone) is coated by prodigious masses of the iron ore, which is worked in open quarries, and is most mag- netic where it is in contact with greenstone. Copper ores also abound at this spot, and some of them are associated with Silurian limestone, often highly mineralized, but in which large Pentameri and other fossils are observed ; also with a bedded trappean rock or schaalstein, which is in parts highly cupriferous. It is from such ancient rocks that copper solutions are supposed to have flowed, in very remote periods, into the adjacent low countries on the west, then under the sea, and to have impregnated the sandstones and grits of Perm during their formation. The malachites of this place have long been celebrated, and, from their structure as well as their position, in cavities of the rock, they are supposed to have been formed by ancient stalactitic depositions. The ores of platinum, though hitherto found in alluvia only, always occur near the pro- trusive igneous rocks. Magnetic iron ore and copper ore are stated to occur at many other localities, and always under similar circum- stances. Gold Ores. — Though the great supply of gold which the Ural mountains afford, is derived from alluvia, the ore has been found in veins which are slightly worked at Berosofsk, near Ekaterinburg, and were formerly near Miask f. Wherever gold veins or gold alluvia have been discovered, the auriferous matter is flanked by rocks of intrusive origin, and these are very frequently serpentine. It has however been shown by Humboldt and Rose, who, in the first volume of their recent work, have described twenty-seven sites of gold alluvia in these mountains, that the auriferous detritus rests upon a great variety of rocks, viz. talcose, chloritic, siliceous, argillaceous schists and encrinite limestone, as well as upon granite, greenstone and serpentine, though most frequently on the last-mentioned rock. An observation also of these authors is im- portant, as bearing upon the relative date of the origin of gold, viz. that the veins containing it have been seen by them to cut through not only the schists and the beresite (according to them * The largest masses of chromate of iron occur in the South Ural, near the mines of Polikofski, south of Miask, and from whence from 6000 to 7000 " pouds " per annum have recently been sent to Moscow. f In the tracts around Miask and Zlataoust the authors were most cordially and judiciously assisted by General Anosof, an officer highly distinguished for the metallurgic processes and the manufacture of small- arms which he directs. His assistant, Major Lissenko, who has prepared a mineralogical map of the surrounding country, was also kindly serviceable to them. K2 132 Mr. Murchison on the Geological Structure a felspathic granite), but also the serpentine ; thus seeming to prove that the gold veins have resulted from one of the very last changes which have affected this region. (Rose, vol. i. p. 422.) It is stated, that as the alluvia containing gold are purely of local origin, or derived from the adjacent hills, theip accumulation can have no reference to the actual period, and present rivulets or waters, for the deposits lie at considerable heights above their beds, contain bones of mammoths, the extinct rhinoceros, and, in some instances, are even traceable over small ridges of intrusive and altered rocks from veins whence the detritus was doubtless derived, and ac- cumulated in its present state at the period when the large mammals were destroyed. Numerous sections are given at Berosofsk, Soi- manofski Zavod, and notably from the environs of Miask and Cos- satchi Datchi, all of which tend to establish these views, as well as those of the alteration, mineralization and crystallization of the palaeozoic strata by the intrusion of igneous matter, and prove that the alluvia were collected anterior to the existing epoch. Some of the gold alluvia are exclusively composed of carboniferous lime- stone replete with fossils (Cossatchi Datchi). In concluding this sketch of the Ural mountains, the authors ad- vert to the remarkable fact, that all the superficial detritus is local, and that no large boulders or blocks transported from afar are visible either in the chain or in the low countries on its flanks; and they also state, that they nowhere observed among the higher por- tions of the mountains any traces of those scratches or polishings of the rock which are common in some parts of Europe, and which are supposed to have been produced by glacial action. Original maps and sections of the districts around the mining establishments of Bogoslofsk, Turinsk and Blagod at Ekaterinburg, Soimanofsk, Zlataoust and Miask, prepared by the officers of the Imperial School of Mines, were exhibited, as well as a map of the North Ural to 65° N. lat., drawn by Strajefski, together with a most elaborate geographical map of the South Ural, executed by orders of General Perovski, under the superintendence of the officers of the staff of his government, directed by General Rakosofski*. From all these documents and others published in the volumes of the ' Journal of the School of Mines,' combined with their own ob- servations, the authors have coloured geologically the map of Hum- boldt, a reduction of the chief features of which will appear in a map now in progress, which will accompany their forthcoming work on Russia and the Ural mountains. General Conclusions. — In greatly extending the knowledge which they had previously acquired, the survey of last year has enabled the authors to modify their earlier views concerning the equivalents of some of the strata of Russia in Europe. With respect to their former account of the great tripartite palaeozoic series of beds which covers such large portions of Northern Russia, they have * This map is illustrated by a description of the physical features of South Ural from the pen of M. Khanikof, which Mr. Murchison has com- piunicated to the Royal Geographical Society of London. of the Ural Mountains. 133 nothing to retract. On the contrary, by adding to their previous lists a great number of typical organic remains well known in Western Europe, they are still more convinced of the accuracy of their first classification, and of the existence of large zones of Silurian, Devo- nian and carboniferous rocks, clearly separated from each other by their order and their imbedded fossils. The newly discovered dome of Devonian rocks in the centre of European Russia is a feature of great importance, in explaining the difference between the mineral basin to the north and that to the south of it. The carboniferous system, the most widely extended deposit of Northern Russia, has now been subdivided into stages, each characterised by its fossils ; and it has been clearly shown, that the most productive of the coal-bearing strata in the Russian em- pire, viz. those of the southern steppes, are associated with the mountain limestone ; whilst the uppermost member of the system, or coal-measures, which is so rich in coal in Western Europe, if indeed it exists, is nearly unproductive in Russia. The next great group of rocks in ascending order, is that which has been elaborated in considerable detail under the name of the Permian system, and which, as already shown, is to be considered as a vastly expanded equivalent of the zechstein and associated beds of Germany and the magnesian limestone of the British Isles. This system is rendered much more important by its fossil contents in Russia than by any remains which have been discovered in it in other parts of Europe ; for not only does it contain, like the zech- stein of Germany and the magnesian limestone of England, the re- mains of thecodont saurians and certain fishes (Palaeonisci), but also a fauna much more copious in other classes, and a flora in- finitely more rich than any which had been previously made known as pertaining to rocks of this age. This flora is shown to be of in- termediate characters between that of the carboniferous system and the plants which have been published as typical of the trias. The Permian system is also of high interest in setting before us the example of wide accumulations impregnated throughout great thicknesses with copper, and as this matter has manifestly been de- rived from the mineral masses of the adjacent Ural, so is it inferred that these mountains constituted dry land on which the plants in question grew, and that the latter having been washed down into these Permian deposits were there rendered the nuclei of the copper ores which are arranged around them. The thin layer of kupfer schiefer of Germany may be considered as the miniature representative of this great metalliferous deposit, whilst in its large masses of gypsum, the Permian deposits exceed even the zechstein on the south of the Hartz*. The Jurassic system of Russia reposes on the Permian and older rocks without clear evidence of the existence of any part of the Triassic group, there being no traces of the muschelkalk limestone nor yet of the keuper $ and it is with doubt even that the authors * The authors use the term " Permian" in reference to Russian deposits only, and they by no means seek to interfere with the general use of the word "Zechstein," which has been so long sanctioned by the highest Ger- man authorities. 134 Mr. Murchison on the Ural Mountains. refer any portion of certain red strata which partly overlie the Per- mian rocks to the " hunter sandstein,'' or new red sandstone of geologists. True lias has not yet been seen, but the Jurassic system is clearly divisible into upper and lower formations, and is followed by the cretaceous and tertiary systems, the latter including eocene, mio- cene and pliocene shells, and all these groups are copiously developed and clearly recognisable by their respective mollusca. The geological survey of the flat regions of Russia, add the authors, in affording the best proof which has yet been obtained in any part of the world of the same extent, that distinct forms of animal life were successively created and entombed in each succeeding de- posit, has also demonstrated that the successive obliteration of these classes was not caused by the outburst of contiguous plutonic rocks or great physical disturbances of the strata ; for in this region, as large as the whole of those districts of the continent of Europe where geology has been most studied, no intrusive rocks are visible, and the wide-spread formations from the Silurian to the youngest ter- tiary, which must have occupied so vast a lapse of time in their ac- cumulation, as well as the beds of retired modern seas, all repose conformably upon each other. And yet with this regular sequence throughout so vast a series and the absence of any great ruptures, the contents of each succeeding system of older strata are as clearly separable from each other as in those parts of the world where younger rocks are incumbent on the uplifted edges of those which had been previously dislocated. But whilst they offer no traces of great and violent upheavals, the horizontal rocks of Russia bespeak most clearly that their sur- face has been so far acted upon by elevatory or subsiding movements, that in some tracts great thicknesses of strata are omitted. Bounded as this large geographical basin has been in remote epochs by the plu- tonic eruptions of Lapland and Sweden on the north, of the Ural on the east, of the granitic steppe on the south, and of the trappean rocks of Poland and Silesia on the west, it is possible, however, that the changes which were evolved in these regions may have affected and influenced the distribution of animal life in the great Muscovite depression which they surrounded. As every geological phenomenon in the strata of the plains of Russia indicates a sub- marine succession, so does the surface announce the same conditions. In the far northern districts the bottom of the Arctic Sea has been shown, by the presence of many existing species of shells, to have once extended over a wide tract of land, now 150 or 200 feet above the sea-level ; and in the south-west it is known by like proofs that the Caspian once covered still wider districts of the steppes. Again, the authors have endeavoured to show that the mammoth alluvia, the boulders of the North and the black earth of Central and South- ern Russia, have all been accumulated under water. In reference to the question of the transport of the northern blocks, the authors conceive that their last survey has tended very materially to strengthen the opinions which they previously ex- pressed, that such material* were carried to their present position* Hoy al Irish Academy. 135 by floating icebergs liberated from ancient glaciers in Scandinavia and Lapland, at a period when Russia in Europe was submerged. The examination of the Ural has in the meantime convinced them of the utter inapplicability of a terrestrial glacial theory even to all mountainous tracts of the earth ; for these mountains, the peaks of which rise to upwards of 5000 feet above the sea, though situated in so cold a climate as to be now covered with snow during eight months in the year (and some peaks are never uncovered), show none of those signs insisted on by glacialists, of their having been at any period the residence of permanent glaciers. With the total absence of such proofs, so it is a striking confirmation of the con- nexion between glaciers and the blocks which in Russia in Europe are supposed to have been floated from Scandinavia and Lapland, that the flanks of the Ural chain and the adjacent plains are entirely void of all such far-transported detritus*. XIX. Proceedings of Learned Societies. ROYAL IRISH ACADEMY. [Continued from vol. xxii. p. 495.] Nov. 30, ''l^HE following communication " On the Compound Na- 1841 . * ture of Nitrogen," by George J. Knox, Esq., was read. Soon after the discovery of the bases of the alkalies and earths by Sir Humphry Davy, the compound nature of nitrogen began to be a subject of discussion amongst chemists ; but the arguments in favour of this supposition, deduced principally from the nature of the ammoniacal amalgam, led to no satisfactory physical results. The experiments of Sir Humphry Davy on the ammoniacal nitruret of potassium, and those of Despretz and Grove f on the compounds of nitrogen with iron, copper, &c, have shown that the metals singly (even when aided by the most powerful electrical induction) have not the power of decomposing nitrogen. There is one experi- ment, however, by Sir Humphry Davy, from which one might de- duce its compound nature. Upon heating ammonia-nitruret of potassium in an iron tube, he obtained more hydrogen, and less nitrogen, than the ammonia ought to have given. Again : on mixing this substance with a greater proportion of potassium, he obtained still more hydrogen, and less nitrogen ; whereas, on heating the same substance in a tube of platinum, the potassium alloyed with the platinum, and the ammonia was given off almost entirely undecomposed. How can these experiments be explained except upon the suppo- * The authors announced that the geological map of Russia and the Ural, as taken from their larger documents, would be published in a short time, and that their work descriptive of all the phaenomena alluded to in these notices would be prepared in the ensuing [1842-43] winter. [f Prof. Grove's paper here referred to will be found in Phil. Mag. S. 3. vol. xix. p. 97 ; and a notice of M. Despretz's experiments in Phil. Mag. S. 2. vol. vi. p. 147.— Edit.] 136 Royal Irish Academy. sition that the potassium and the iron had conjointly decomposed the nitrogen ? The latest experiments which bear upon this subject, and from which I received the idea which led me to this investigation, are those of Dr. Brown* " upon the conversion of carbon into silicon," an explanation of phenomena which appears to me most unreason- able, and contrary to all chemical analogy ; whilst the supposition of the carbon having reduced the nitrogen is not only a simple but an unavoidable conclusion to arrive at, if nitrogen be a compound sub- stance. To determine, by experiment, the correctness or incorrect- ness of this idea, it were only necessary to reduce nitrogen by some other substance than charcoal ; and should silica result from its de- composition, the problem might be considered to be solved. Exp. I. — A considerable quantity of ammonia-nitruret of potas- sium was formed, by passing ammonia over potassium heated in an iron tube ; the part which had not been in contact with the tube, having been examined for silica, contained none. Exp. II. — Ammonia was passed for several hours over pure iron, heated to a dull red heat ; examined for silica, it contained none. Exp. III. — Ammonia-nitruret of potassium was heated with pure iron in an iron crucible, for one half hour, over a large Rose's lamp ; the contents of the crucible, on examination, gave silicon and silica, the weight of which was not registered, as it might have been said to have derived a portion of silica from the inner surface of the crucible. Exp. IV. — Twenty grains of ammonia-nitruret of potassium were heated with twenty grains of pure iron in the same iron vessel for one half hour ; when treated with nitric and muriatic acids there remained insoluble a small quantity of a brownish colour, which, when fused with carbonate of potash, gave of silica 0*10. The solu- tion, supersaturated with potash, filtered, neutralized, evaporated to dryness, gave of silica 1450 ; sum total of silica 1*550. From these experiments, together with those of Sir Humphry Davy mentioned above, one might infer that nitrogen is either a compound of silicon and hydrogen, or of silicon, hydrogen, and oxy- gen ; to determine which, synthetically, a current of dry muriatic acid gas was passed over siliciuret of potassium (formed by heating silica with potassium), placed in a bent tube of Bohemian glass, the extremity of which dipped into a cup of mercury, lying on the bottom of a vessel filled with water. The atmospheric air had been pre- viously expelled from the apparatus by a current of hydrogen. The gases insoluble in water having been collected, were found, on examination, to be hydrogen and nitrogen, the relative propor- tions of which varied in different experiments. In two experiments the proportions of hydrogen to nitrogen were four of the former to one of the latter. In a third experiment, as six of hydrogen to one of nitrogen. In a fourth, as five of hydrogen to four of nitrogen. Observation. — White fumes appeared occasionally in the tube, indicating the presence of muriate of ammonia. L* See Phil. Mag. S. 3. vol. xix. p. 295, 388 • vol. xx. p. 24.— Edit.] Royal Irish Academy. 1S7 Professor Lloyd exhibited a specimen of rock from Terre Adele. Professor MacCullagh communicated to the Academy a very simple geometrical rule, which gives the solution of the problem of total re- flexion, for ordinary media and for uniaxal crystals. First, let the total reflexion take place at the common surface of two ordinary media, as between glass and air, and let it be proposed to determine the incident and reflected vibrations, when the re- fracted vibration is known. It is to be observed, that the refracted vibration (which is in general elliptical) cannot be arbitrarily as- sumed ; for, as may be inferred from what has been already stated (Proceedings of the Academy, vol. ii. p. 102. Phil. Mag. S.3. vol.xxi. p. 232), it must be always similar to the section of a certain cylinder, the sides of which are perpendicular to the plane of incidence, and the base of which is an ellipse lying in that plane and having its major axis perpendicular to the reflecting surface, the ratio of the major to the minor axis being that of unity to the constant r. The value of r, as determined by the general rule given in the place just referred to, is = vA where i is the angle of incidence, and n the index of refraction out of the rarer into the denser medium. The ellipse is greatest for a particle at the common surface of the media ; and for a particle situated in the rarer medium, at the distance z from that surface, its 2l? + r'3*/ du,\±-'rdr. F (r, w) = 0 being the polar equation of the given curve. It is convenient to distinguish the curves of the two series by calling those of the former positive, and those of the latter negative ; we may also generally denote their polar coordinates by the symbols If the given curve, which may be denominated the base of either system, be an ellipse whose centre is the origin, it will be found, by applying the above formula, that the negative curves will in general have their arcs expressible by elliptic integrals of the first and second kinds, whose modulus is the eccentricity of the base-ellipse. The arc of the first will involve only a function of the first kind : a result Royal Irish Academy. 1 39 which has been given by Mr. Talbot, in a letter addressed to 3VI. Gergonne, and inserted in the Annates des MatMmatiques, torn. xiv. p. 380. A function of the third kind, with a circular parameter — 1 + £+, where b is the semiaxis minor of the ellipse, its semiaxis major being unity, and the modulus of which is the eccentricity, enters into the arcs of all the positive curves ; and their general rectification depends only on that of the ellipse, and of the first derived, both positive and negative. The quadrants of the ellipse, and of the first two curves, positive and negative, are connected by the following relation : — (S^ + SJS.., = (3S-S_2)(2S-S2). */~5 I It is worthy of notice, that if the eccentricity be 1 the functions of the third kind disappear, and the rectification of both series depends only on that of the ellipse and of the first negative curve. If the base curve be a hyperbola, whose centre is the origin, the arcs of all the curves of the negative series will depend only on el- liptic functions of the first and second kinds. But the general ex- pression for the arc in the positive series contains a function of the third kind, the parameter of which is alternately circular and loga- rithmic ; the curves of an odd order involving the same function of the circular kind, and those of an even order the same of the lo- garithmic kind, if the real axis of the base-hyperbola be greater than the imaginary, and vice versd. Mr. Roberts also shows, that besides the case of the equilateral hyperbola, in which the first positive curve is the lemniscate of Bernoulli, and which has been the only one hitherto noticed, at least as far as he is aware, there are two others, in which the arc of the first positive curve can be expressed by a function of the first kind, with the addition of a circular arc in one case, and of a logarithm in the other. The first of these occurs when the imaginary semiaxis is equal to — (the distance between The centre and focus being unity), and this fraction is the modulus of the function. The other case is furnished by the conjugate hyperbola, and the modulus is complementary. In both these cases functions of the third kind dis- appear from the arcs of the positive curves. If the hyperbola be equilateral, and its semiaxis be supposed equal to unity, the general equation of the derived curves of both series may be presented under the form 2 + 2n-l r+M = cos \ + 2« — 1/ The successive curves represented by this equation are very curiously related to each other. The following property appears worthy of remark : — 140 Royal Irish Academy, Let P„_i, P;,; Pn+i be corresponding points on the (ra — l)th, nth, and (w + l)th curves of the positive series respectively, and V their common vertex, which is also that of the hyperbola, then will arc VP„_! + right line Pw_! P„ m l!Lzl arc V P»j.i, 2«+l Mr. Roberts states that he has demonstrated the property in a manner purely geometrical. This equation shows that the arcs of all the curves of an odd order will depend only on that of Bernoulli's lemniscate, or the function F { *2> P}> and those of an even order only on the arc of the second of the series. This latter arc is three times the difference between the corresponding hyperbolic arc and the portion of the tangent applied at its extremity, which is intercepted between the point of contact and the perpendicular dropped upon it from the centre : and the entire quadrant is three times the difference between the infinite hyperbolic arc and its asymptot. Also, Sw, Sn+i, denoting the quadrants of the rath, and (ra+l)th curves, the following very remarkable relation exists between them : S„ Src+i = (2 ra+1)— . The curves of the negative series enjoy analogous properties. Lastly, let the base curve be a circle, the origin being within it : and it appears that the rectification of the curves of both series, which are of an even order, can be effected by the arcs of circles ; and that those of an odd order, which belong to the positive series, will in- volve elliptic integrals of the first and second kinds in their arcs. The negative curves of an odd order contain a term depending on a function of the third kind, which is however reducible to a function of the first kind and a logarithm. By the particular consideration of the first negative curve in this case, Mr. Roberts was led to a very simple demonstration of the equation which results from the application of Lagrange's celebrated scale of reduction to elliptic functions of the second kind, and which is nothing more than the analytical expression of Landen's theorem. William Roberts, Esq., F.T.C.D., read a paper on a class of sphe- rical curves, the arcs of which represent the three species of elliptic transcendents. A cone of the second order, whose vertex is upon the surface of a sphere, and one of whose principal axes is a diameter, will inter- sect the sphere along a curve which admits of several varieties, ac- cording to the nature of the sections of the cone parallel to its prin- cipal planes, and the position of its internal axis. This curve may be made to furnish, by means of its arc, a geometrical representation of the three species of elliptic trancendents, including the two cases of the third. In the course of the investigations alluded to, Mr. Roberts was also led to consider two species of the curve called the spherical conic, which appear to possess many remarkable analogies to the Royal Irish Academy. 141 properties of the equilateral hyperbola. These cases occur when, the axis minor is a quadrant, and when the semi-axes a and b are connected by the relation sin a = tan b. A notice of the occurrence of a Metallic Alloy in an unusual state of aggregation and molecular arrangement, was read by Robert Mallet, Esq., M.R.I.A, Amongst the several classes of substances which chemistry at present considers as simple, the metals stand preeminently marked by their almost invariable possession of a nearly fixed and striking group of sensible qualities, which together constitute the well-known " metallic character." Some of these, such as lustre and fusibility, are common to every metallic body ; but by the occasional variation of nearly every other sensible quality of the metals, the law of con- tinuity remains unbroken, which unites them in different directions with the other classes of material bodies. Thus opacity, which is probably mechanically destroyed in gold leaf, is lost in selenium ; and so, in this most prevalent of their properties, the metals, through tellurium, selenium and sulphur, become translucent, and mingle with the non- metallic elements. So also their solidity, at common temperature, is lost in mercury ; their great density, in sodium and potassium ; their malleability, in bismuth, antimony, and arsenic ; while in tellurium, the power to conduct electricity is nearly wanting; and, lastly, hydrogen, to all intents a metal in its chemical relations, yet possesses not a single physical quality in common with these, but exists as an invisible and scarcely ponderable gas. But although different metals thus vary in sensible qualities, those which collectively belong to the same individual metal are as re- markable for their permanence. Unless selenium be admitted to be a metal, no approach to di- morphism has hitherto been recognized in any body of the class ; the only case recorded, that by Dufresnoy, of the occurrence of cast iron in cubes and rhomboids, not having been given by him with certainty, nor since verified by other observers. Hence any instance of such a character, or tendency towards it, is worthy of attentive consideration ; and it was with this view that the author brought before the Academy the following notice of the occurrence of an alloy of copper, in two states, having totally different sensible and physical qualities, while identical in chemical constitution. The alloy in question, in its original or normal condition, was in fact a species of brass ; and the particular specimen presented to the Academy was a portion of one of the brass bearings, or beds, in which the principal shaft of a large steam-engine revolved. The bearing, or bed of a shaft (as is generally known), consists of a hollow cylinder, generally of brass, divided in two by a plane passing through the axis ; its inner surface is finely polished, and sustains the shaft, during its revolution, which is also polished ; the cavity of the brass being completely filled by the shaft, which, in the present instance, was of cast iron, and about nine inches in diameter. 14-2 Royal Irish Academy. It frequently happens, notwithstanding the polish of both metallic surfaces, and the application of oil, that the friction due to their rapid passage over each other, while exposed to undue or irregular pressure, produces a considerable rise of temperature, and the brass becomes abraded. Its particles have no coherence, and much re- semble the " bronze powder " used by painters. In an instance, however, which some time since came under the author's notice, a different result took place. The minute particles of abraded brass were by the motion of the shaft, during a few hours, impacted into a cavity, at the junction of the two semicylinders of the bearing, where they became again a coherent mass, and when removed presented all the external appearance of an ingot or piece of brass which had been poured in a state of fusion into the cavity. On more minute examination, however, the mass was found to differ much in properties from the original brass, out of which it was formed. The mass or ingot of brass, thus formed by the union of particles at a temperature which had never reached that of boiling water, and a fragment of which was presented, possessed on that side which had been in contact with the shaft, a bright polished metallic surface, like that of the original metal from which it had been formed : its other surfaces bore the impress of the cavity in which it was found. It was hard, coherent, and could be filed or polished like ordinary brass. It was, however, perfectly brittle ; and when broken, the fracture, in place of possessing a sub-crystalline structure and me- tallic lustre, like that of the normal brass or alloy, was nearly black, and of a fine grained earthy character, and without any trace of metallic lustre or appearance. Examined with a lens, some very minute pores or cavities are found throughout its substance, which is uniformly of a very dark brown or nearly black colour, and devoid of all metallic character, except when cut or filed — that is, in minerological language, its co- lour is earthy black, and its streak metallic. The author remarked that the observed cases of aggregation in solid particles, without the intervention either of a solvent or of fusion, are extremely rare, and as bearing upon the little understood subject of cohesive attraction, are of much interest. The property of welding, which is possessed by all bodies, whether metallic or not, which pass through an intermediate stage of soft- ness or pastyness previous to fusion, and is not found in any sub- stance which readily crystallizes, and hence passes per saltum from the solid to the liquid state by heat, forms a " frontier instance " of cohesive forces, being enabled to act in the aggregation of bodies, by only an approach to liquidity, or by a very small degree of inter- mobility. Aggregation may also take place between portions of a body merely softened by a solvent, which is afterwards withdrawn, as in the familiar instance of Indian rubber, softened by naphtha for the manufacture of waterproof cloths ; where the former, after being moulded or united in any way required, is left in its pristine condi- Royal Irish Academy. 143 tion by the evaporation of the naphtha from amongst its particles. But the cases of aggregation of solids, without such elevation of temperature, or the presence of solvents, are so rare, that but two or three have as yet been observed. Of these the most remarkable is that recorded by Pouillet, of the gradual, but complete, adhesion of surfaces of clean plate-glass, when left to repose on each other for a considerable time. It has also been stated, that clean plates of lead or of tin, if pressed together by a considerable force when cold, require a proportionably great force to separate them. The case presented to the Academy, therefore, is another added to these rare instances of molecular aggregation in solids, independent of solution of fusion : the author therefore thought it worth while to examine with a little care the properties both of the original brass, and of the mass thus curiously formed from it, or, as he thenceforth called them, of the normal and the anomalous alloy. The normal alloy is of a bright gold colour, and sub-crystalline in structure, and of great toughness ; its cohesive force is equal to 21*8 tons per square inch, which is above the average strength of any of the alloys of copper and zinc, or copper and tin, as found by my experiments on the cohesive power of these alloys, published in the Proceedings of the Academy, and elsewhere. The cohesive force of the anomalous alloy is only T43 ton per square inch, or only about one-fifteenth that of the former. The specific gravity of the normal alloy is = 8" 600; that of the anomalous only = 7 '581. On submitting both alloys to analysis, their constitution proved identical ; it is as follows : — Copper 83-523 Tin 8833 Zinc 7-510 Lead 0-024 Loss 0-110 100000 Uniting the small amount of lead with the tin, and dividing by the atomic weights, the nearest approach to atomic constitution is, — Copper = 26" 3 atoms. Zinc = 2-3 ... Tin = 1-5 ... These alloys have therefore not a strictly definite constitution, but one more nearly so than is usually found in commerce. Both alloys are equally good conductors of electricity. The author examined their relative powers of conducting heat by the method which Despretz has employed with so much accuracy, and found that of the normal to that of the anomalous alloy as 36 : 35, numbers which are so nearly equal as to render it likely the differ- ence is only error of experiment. He also endeavoured to deter- mine their relative specific heats, using the method of mixture, which was the only one which the small size of the metals permitted, and eliminating the errors incident to this mode by first plunging the 1 44 Royal Irish Academy. alloy hot into cold water, and then cold into hot water. In this way, if W and t = the weight and temperature of the water, M and t' == the weight and temperature of the metallic alloy, m .... = the mean temperature of both, S . . . . = the specific heat of the alloy, there are two values, one where the metal is the hotter, s_ W(m-t) , M (t'—m) ' and another where the water is the hotter body, a _ W (t-m) M {m-t')' the mean of which is the specific heat of the alloy pretty exactly. The result gave the specific heat of the normal alloy = '0879, water as unity, and that of the anomalous alloy = '0848 ; both of which are below the specific heat assigned by Dalton to brass. The normal alloy is malleable, flexible, ductile, and laminable. In the anomalous alloy there is an absolute negation of all these pro- perties. The normal alloy readily amalgamates with mercury at common temperatures ; the anomalous alloy will not amalgamate with mer- cury even at 400° Fahrenheit. When the anomalous alloy is heated to incipient redness in a glass tube, a minute trace of water, and of a burned organic sub- stance, probably adherent oil, are discoverable ; it suffers no change, however, but a slight increase of density. The normal alloy suffers no change when so treated. The normal alloy, treated on charcoal with the blowpipe, fuses at once into a bead. On treating the anomalous alloy so, the fragment swells rapidly to more than twice its original bulk, on becoming bright red-hot ; it then glows, or be- comes spontaneously incandescent, in the way that hydrated oxide of chrome and some others do, and instantly contracts to less than its original bulk, and becomes a fluid bead, which, on cooling, dif- fers in no respect from the original alloy. The anomalous alloy, when pulverized in an agate mortar, forms a black powder, devoid of all appearance of a metal ; its filings also are quite black ; while those of the normal alloy, produced by the same file, possess the usual metallic lustre. These facts, in con- nexion with the black colour and fine earthy appearance of the frac- ture, bring to mind the case recorded by Sir David Brewster, of a piece of smoky quartz, the fracture of which was absolutely black, and yet was quite transparent to transmitted light, and whose black- ness, he found, arose from the surfaces of fracture, consisting of a fine down of short and slender filaments of transparent and colour- less quartz, the diameter of which was so small (not exceeding the one-third of the millionth - part of an inch), that they were inca- pable of reflecting a single ray of the strongest light. In describing this, Sir David Brewster predicted that " fractures of quartz and other minerals would yet be found which should exhibit a fine down of different colours depending on their size." Royal Astronomical Society. 145 It seems, therefore, extremely probable, that the cause of the near approach to blackness in the fracture and filings of this alloy, arises from the excessive minuteness of its particles, and thus fulfils the foregoing prediction ; the brownish tinge being produced by the reflexion of a little red light *. The polish and power of reflecting light of the anomalous alloy are not quite so great as those of the normal, but are still remarkable ; and, as it seemed a matter of some interest to determine whether both reflected the same quantity or intensity of light at equal angles, the author endeavoured to ascertain this point as respects heat, by means of Melloni's pile for the galvanometrical determination of temperature, assuming, as suggested to him by Professor MacCul- lagh, that what would be true of heat in this respect, would also be so of light ; but from the small size of the reflecting surfaces he had at his command, he found it impossible to arrive at any trustworthy result. He is, however, inclined to believe, that both metals reflect most at a perpendicular incidence. From the foregoing detail of the properties, in several respects so different, of this substance in its normal and anomalous states, the author thinks he is warranted in pronouncing it the first observed instance of an approach to dimorphism in a metallic alloy ; and one, the mode of production and characteristics of which present several points of interest. The conditions under which the alloy was aggregated, involved extremely minute division of the metal, great pressure in forcing the divided particles into contact, and nearly the exclusion of air. Considerable electrical disturbance may have also cooperated ; such, together with induced magnetism, being the constant accompani- ments of motion in heavy machinery. By re-establishing these con- ditions, under suitable arrangements, the author hopes to repeat the results thus accidentally first obtained, and so produce possibly di- morphous states of other metals or their definite combinations. There is but one body which occurred to the author presenting an analogy to this anomalous alloy, namely, indigo ; whose fracture, it is well known, is fine earthy, and of the usual blue colour, but becomes coppery, or assumes the metallic lustre on being rubbed or burnished. ROYAL ASTRONOMICAL SOCIETY. [Continued from vol.xxii. p. 570.] June 9, 1843f. — The following communications were read: — I. On a Self-acting Circular Dividing Engine. By W. Simms, Esq. The original graduation of a circle, notwithstanding the great improvements in the method invented by Mr. Trough ton, is still attended with very great difficulties, requiring not only the greatest * Since this paper was read, Professor Lloyd suggested to the author, the analogy between the appearance of the powder and filings of the ano- malous alloy and Platina Mohr, and those powders obtained by reduction of other metals by hydrogen. None of these, however, are coherent, which constitutes the peculiarity in the present case. T The proceedings of the Society in April and May will be noticed hereafter. Phil. Mag. S. 3. Vol. 23. No. 150. Aug. 1843. L 1 46 Royal Astronomical Society. care on the part of the operator, hut tending to injure his health hy the labours required in it, and thus not admitting of frequent re- petition. The necessary cost of an instrument produced by such an amount of severe labour is also another very serious objection. The author had long been of opinion, that to copy the divisions of a circle which had been graduated with extraordinary care, upon work of smaller dimensions, would in general be more satisfactory than original graduation. The latter process consists of several suc- cessive steps, in either or all of which a certain amount of error may escape detection, which in general may go far to balance one another, although there will be parts in almost every work where errors appear arising from an accumulation of those minute quantities. The author had long since determined, as soon as he could obtain sufficient leisure, to construct an engine sufficiently large for the graduation of all circles, excepting those of the largest class, and the object of this paper is to lay before the Society a brief notice of the successful termination of the work. The engine, in general arrangement and construction, is similar to that made by Mr. Edward Troughton, in the author's possession, though there are several additions and peculiarities which are pointed out by him. The circle or engine-plate is of gun-metal, 46 inches in diameter, and was cast in one entire piece by Messrs. Maudslay and Field, teeth being ratched upon its edge. The centre of the engine-plate is so arranged that it can be entered by the axis of the instrument to be divided, and the work by this means brought down to bear upon the surface of the engine- plate, which arrangement pre- vents the necessity of separating the part intended to receive the divi- sions from its axis, &c. — a process both troublesome and dangerous. Upon the surface, and not far from the edge of the engine-plate, are two sets of divisions to spaces of five minutes, one set being in silver and the other strongly cut upon the gun-metal face. There are also as many teeth upon the edge as there are divisions upon the face of the engine-plate, namely, 4320, and consequently one revolution of the endless screw moves through a space of five minutes. The silver ring was divided according to Troughton's method with some slight variations. In this operation it seemed to the author the safer course to divide the circle completely, and then to use a single cutter for ratching the edge ; and he believes that the teeth upon the edge have been cut as truly as the original divi- sions themselves. Another very important arrangement is, that the engine is self- acting and requires no personal exertion or superintendence, nothing being necessary but the winding up of the machine, or rather the raising of a weight, which, by its descent, communicates motion to the dividing engine. The machinery is so arranged that it can be used or dispensed with at pleasure, there being some cases in which a superintending hand is desirable. The author then proceeds with a description of the machinery, as represented in the drawings accompanying his paper, and draws particular attention to the contrivance by which the engine can dis- charge itself from action when it has completed its work. Royal Astronomical Society. 147 He concludes by observing, that as the machinery is simple, by no means expensive, can be made by an ordinary workman, is adapted to all the engines now in existence which are moved by an endless screw, as it lessens the labour of the artist and increases the accuracy of the graduated instrument, he trusts his communication will prove acceptable to all who are interested about such matters. II. Recomputation of Roy's Triangulation for connecting the Observatories of Greenwich and Paris. By W. Galbraith, Esq. The author considers from internal evidence that Roy's measure- ment of the base on Hounslow Heath was in his own scale, and that of Mudge in Ramsden's scale, and he has used in his calculations the mean of these in imperial measure, reduced to the mean level of the sea. He has also availed himself of the New Survey of France to obtain such data as it afforded to connect the two countries. Some of the most important of the results are as follows : — As- suming the latitude of Greenwich to be 51° 28' 38"*50 N., and the compression of the earth to be ^q, there results for Calais Lat. 50° 57' 27"*67 N. ; Long. 1°51' 17"*30 E. Dunkirk Lat. 51 2 6 -68 N. ; Long. 2 22 39 '72 E. I Again, assuming from the new Description Geometrique de la France, the long, of Calais to be 29' 0"*40 West of Paris, and that of Dun- kirk 2' 22*"66 East of Paris, h m ■ The long, of Paris by comparison with Dunkirk is 2 20 17*70 E. Calais 2 20 17-06 Calais, from Kater's New Survey 2 20 19- 13 h m s The Mean of which in Time is 0 9 21*20 E, Mr. Dent's Result by Chronometers was 0 9 21*21 And Sir J. Herschel's by five signals. . . 0 9 21*46 III. Occultations of Fixed Stars and the Planet Jupiter by the Moon. Observed at Hamburgh by C. Rumker, Esq. These will be found in the Monthly Notices of the Society, vol. v. p. 293. IV. The following communications concerning the Great Comet of 1843*:^- 1 . Notes on its Appearance made during a Voyage from the Cape of Good Hope to England. By M. Close, Esq., Commander of the Ship Ellenborough. It was first seen on the evening of the 4th of March, and before the discovery of the nucleus on the same evening was taken for a lunar iris. The nucleus was on this evening estimated to be of equal brightness with a star of the second or third magnitude, and the length of its tail 32° 30'. The tail had a darkish line from its nu- cleus through the centre to the end. Stars of the third magnitude were visible through the broadest part, but not near the nucleus. It was seen on several evenings, the last time being on the evening of the 31st of March ; it was occasionally brilliant enough to throw a strong light on the sea. The greatest length of tail estimated was on the 19th of March, it being then 43° 30', and it was observed to * See also p. 54 of the present, and p. 323 of the preceding vol. — Edit. L2 148 Royal Astronomical Society. have considerable curvature. The account was accompanied by a small sketch of its appearance on the 5th of March. 2. A Letter from John Belam, Esq., Master of H. M. Sloop Alba- tross, on the Great Comet of 1843. Communicated by G. B. Airy, Esq., Astronomer Royal. " On the 2nd of March, in latitude 18° 33' 18" N. and longitude 72° 17' 0" West of Greenwich, a meteor made its appearance in the western quarter of the heavens of a whitish colour. It became brighter each succeeding evening, and on the 7th we obtained the following observations : — In form it is like an elongated birch rod, slightly curved : the head or commencement of it being nearest the horizon at an altitude of about 19°, the tail pointing in the direction of Sirius, and measuring from the head 28°. That part of it from which the tail is produced is of a reddish appearance, but no star is visible through a common telescope. Greenwich Mean Time. Observed Distance between h m s o t a March 7. 11 54 56 The Comet and Sirius 83 12 10 11 56 33 ... aCanopus.. 75 25 40 Observed Azimuth South, 79° 10'. Greenwich Mean Time. Observed Distance between h m 8 o/i March 13. 11 52 46 The Comet and a Canopus 66 55 10 11 54 46 ... Sirius ... 67 1 40 11 55 46 ... Aldebaran 44 26 30 Its altitude appears to be about 23° ; its azimuth (observed), South 79° 11'. " It showed brightest on the 7th instant, and since then to the 13th it has gradually become fainter. " Since its appearance the generative point has been surrounded by a misty haze, from which cause the observations could not be taken with any great precision. ■ H.M. Sloop Albatross, Port au Prince, St. Domingo, 14th March, 1843." 3. Observations of the Comet by Mr. S. C. Walker and Professor Kendall, at the Observatory of the High School at Philadelphia. Communicated by Lieut. -Col. Sabine. The comet was observed with the 9-feet Fraunhofer equatoreal, and the observations are cleared of the effects of differences of re- fraction, but not of the effects of parallax and aberration. Latitude of the Observatory, 39° 57' 8"; longitude, 5h 0m 41s>9. ————— Date of Observation. Apparent Apparent Sidereal Time. Right Ascension. Declination. d h tii s h m s h m s March 19 7 32 67 2 57 2406 7 32 6-7 —9 27' 36-5 22 7 48 45-3 3 17 43-34 7 44 49-2 —8 36 3-4 23 7 40 33-7 3 23 43-97 7 40 50-1 -8 19 20-8 24 7 35 52-5 3 29 36-28 7 46 32-9 —8 3 330 26 7 57 24-3 3 40 30-54 8 6 54-5 -7 32 32-2 29 8 11 351 3 54 14-26 8 14 100 -6 50 3-1 Royal Astronomical Society. 14-9 The observations of the 19th, 22nd, and 24th, by computations made by the same gentlemen, give the following approximate elements : — Perihelion Passage, Feb. 26*0489, mean time Philadelphia. Ascending Node 1 66° 1' 25" Inclination 39 0 22 Longitude of Perihelion 292 50 31 Perihelion Distance 0*00834 Motion direct. 4. Notes on the Comet, accompanied by a Pencil Sketch, by Capt. Hopkins, commanding the East India Company's Ship Seringapa- tam, on a voyage from the Cape of Good Hope. Communicated by Sir John Herschel. The comet was seen first on the 2nd of March, but indistinctly. A good view of it was obtained on March 4, when it was very bril- liant. Its tail appeared separated through half its length by a dark line, and was, by rough measurement, found to be about 30° in length. After this it decreased in brightness, and was not seen longer than the 7 th of April. 5. Extract of a Letter, dated St. Kitt's, 6th of March, 1843, from Lieut. D. W. Tyler, R.E. 6. Letter from J. T. Austin, Esq., dated Funchal, Madeira, April 8, 1843, accompanying a sketch of the Comet. Communicated by Sir John Herschel. 7. Notes on the Comet as seen by M. Montojo, at San Fernando. Communicated by Sir John Herschel. The tail of the comet was first seen on the 6th of March ; the nucleus was compared roughly with two small stars seen in the same field with it on the 13th; on the 14th and 15th some observations were obtained with an altitude and azimuth instrument, and it was compared with some known stars ; the nucleus was not seen after the 1st of April. 8. An Account of the Comet as seen on board the ship Childe Harold on her voyage from Bombay to London. By Lieut. W. S. Jacob,. R.E. The tail was first seen on the 3rd of March, but a good view of it was not obtained till the 9th. On this evening, the nucleus seen in a night telescope appeared like a star of the sixth magnitude, and the following distances from a Eridani and a Orionis were measured with a sextant : — Distance from a Eridani. Time h m 8 15 16 by watch 46 11 12 25 8 26 10 18 19 56 35 34 21 23 34 34 Distance from a Orionis. ISO Royal Astronomical Society. Watch fast on Greenwich mean time (by estimated long.) 39s,0. The length of the tail 36°. From the above observations Mr. Jacob infers the following place of the comet : — At 7h 42m Gr. M.T. R.A. = lh 17m 9s Decl. = — 11° 59'. The nucleus was last seen on the 5th of April. 9. Letter from T. Forster, Esq., dated Bruges, April 22, 1843. Dr. Forster, with a view of drawing attention to the phenomena observed by him on the 20th of March in connexion with the comet, had accurately represented in a coloured drawing the appearance of the comet and of the surrounding sky, and had caused it to be copied by an artist, with the intention of presenting the same to the Society. The drawing has since been received, and is now in the possession of the Society. 10. An Account of the Comet as seen on board the ship Malabar on her passage from the Cape of Good Hope. By R. Pollock, Esq., Commander. The comet was first seen on the 2nd of March. On the 5th the nucleus was well seen, and appeared as a star of the fourth magni- tude ; the length of tail was 23°. The following measures of the distance of the nucleus and bright stars were made : — o / Dist. from Regulus 53 20 Sirius 74 33 30 \ Long. 7 22 W. Canopus 70 6 Sirius. . 71 41 Canopus 68 47 Sirius 67 0 0^LonS-9 5oW- Canopus 69 30 14. No observations Long. 15 55 W. 11. Letter from H. A. Cowper, Esq., H. M. Consul at Pernambuco in Brasil, dated 9th March, 1843. The comet was seen first on March 1 ; and on the 4th Mr. Cowper saw the nucleus very distinctly, and makes the following remarks on its appearance : — " It is particularly small, without any nebulosity, but of extreme brightness, of a golden hue, and a line of the same bright colour may be distinctly traced running directly from it into the tail for 4° or 5° : the tail is perhaps 30° in length, and is of a brilliant silver colour, perfectly opake, but becoming less and less dense until it is lost in space." Mr. Cowper adds the following observations, made with a sex- tant on March 9, at his request, by a master of a merchant vessel : Bearing of nucleus W. 7 45 S. Altitude of ditto 9 0 Length of tail 28 0 Breadth of tail at two-thirds of its length from the nucleus 1°. 12. Observations made at the Royal Observatory, Cape of Good h m March 10. 7 0 7 35 7 40 11. 7 35 7 40 13. 7 35 7 40 Royal Astronomical Society. 151 Hope, by Piazzi Smyth, Esq. Communicated by Sir John F. W. Herschel, Bart. The nucleus of the comet was first seen on the 3rd of March, but it set about ten minutes after its discovery. It was looked at with the 46-inch achromatic telescope, and an approximate observation was attempted, by leaving the telescope fixed, and measuring, the next morning, the azimuth and altitude of the point where it set. The nucleus seemed to consist of a planetary disc from which rays emerged in the direction of the tail. To the naked eye there ap- peared a double tail about 25° in length, the two streamers making with each other an angle of about 15', and proceeding from the head in perfectly straight lines. From the end of the forked tail, and on the north side of it, a streamer diverged at an angle of 6° or 7° towards the north, and reached a distance of upwards of 65° from the comet's head ; a star (probably r Ceti) was near the end of this appendage ; a similar, though much fainter, streamer was thought to turn off south of the line of direction of the tail. On the 4th of March, Mr. Smyth, accompanied by some friends, went to the Lion's Rump signal station, where the comet would set in a sea horizon, and several distances were taken with sextants and a reflecting circle. These not being reduced sufficiently are not in- serted here. On the 5th the comet was seen, and several sextant observations were made. The appearance of the comet on this evening appeared considerably changed ; the angle of the north streamer with the di- rection of the tail had been diminishing and was now south ; it had also diminished in brightness. The total length was about 35°. All the rays proceeding from the head were now of uniform brightness, excepting one bright streak, which could be traced along the tail. Though the observatory is very deficient in extra- meridional ap- paratus, Mr. Smyth succeeded, on March 6, by various expedients, in obtaining several comparative measures of the nucleus and neigh- bouring stars, of which the unreduced observations only are given. On this evening he makes the following remarks respecting the ap- pearance of the comet : — " The nucleus is now the broadest part of that end of the comet ; all the rays come from the posterior side, and are pretty equal in brightness, with the exception of a narrow bright streak in the middle, which runs for 3° or 4° along the middle of the tail, and then verges to the north side." The tail this evening was about 27° long. Several sextant observations of distance were made this day. On the 8th several differential observations were made. On the 9th some good differential observations and some sextant observations were made. The angle of the two sides of the tail at the head appeared to have undergone a gradual diminution, and the middle part was becoming more and more equal in brightness to the sides. The paper contains also some observations of Laugier's Comet, and some observations of occupations of stars by the moon. 1 52 Royal Astronomical Society. 13. Abstract, by the Secretary, of Newspaper Accounts of the Comet which have been forwarded to the Society. Some of these accounts are of considerable interest, and Mr. Main thought it desirable to collect and to bring them before the Society, which will thus be in possession of almost every thing that has been published relatively to the comet. The first is extracted from a newspaper of Tobago, and is signed M. Dill, Lieutenant Royal Engineers, Superintendent of Signals, and dated Fort King George, 8th March, 1843. " During the last few days our island has been visited by a very large and brilliant comet. It is said to have been seen first on Fri- day evening, but was more generally observed on Saturday, when it presented a most luminous appearance ; the nucleus of "the comet being, at about £ to 7 o'clock, in the direction of south-west, and the tail stretching to an immense length across the heavens in a south-east direction, and in opposition to the sun's light. On Sunday night it was observed by compass, when the nucleus bore west 25° 0' south at \ to 7 o'clock. On Monday an observation was taken with a theodolite at 1 6m£ past 7 o'clock, when the nucleus bore west 16° 7' south, with an elevation of 6° 4', and the end of the tail, as nearly as it could be caught, bore west 28° 14' south, with an elevation of 28° 21'." Similar observations were made of it on the following Tuesday and Wednesday. The following letter from Mr. Benjamin Pierce, dated Cambridge, March 31 , 1843, appeared in the Boston Courier of April 1, 1843 : — " The elements of the comet's orbit, which I send you, are roughly computed, and will need future correction. They agree very closely with Mr. Clarke's noonday observations of February 28, and were computed from Mr. Bond's observations of March 11, 18, 24, and 26. More correct calculations, in which all the observations will be thoroughly discussed, will in due time be presented to the American Academy. Long, of the Ascending Node 348° 33' Inclination 39 16 Long, of the Perihelion 280 31 Perihelion Distance 0'00872 Time of Perihelion Passage, Feb. 27d,01, mean time at Cambridge. Motion retrograde." In another American paper was the following account : — " A comet of unusual size and brilliancy was distinctly visible to the naked eye in this vicinity on Tuesday last, the 28th of February, 1843, at noonday, at a distance, as we should judge, of 5° or 6° east from the sun. It extended over a space in the heavens of nearly 3° in length, with little more than 1° in width, and appeared like a very small white cloud, with its nucleus, or densest part, towards the sun, and its luminous train in opposition to it. On viewing it through a common telescope of moderate power, it presented a distinct and beautiful appearance, exhibiting a very white and bright nucleus, Royal Astronomical Society. 153 and a tail dividing near the nucleus into two separate branches, with the outer sides of each branch convex, and of nearly equal length, apparently 8° or 10°, and a space between their extremities of 5° or 6°. Though viewed several minutes under these favourable circum- stances, no coruscations were perceived." The above American accounts were communicated to the Astro- nomer Royal by Mr. J. Cranch, at the request of Mr. Bond, of the Cambridge Observatory, near Boston. In an article by M. Plana, extracted from the Gazetta Piemontese of the 4th of April, are the following parabolic elements of the comet : — Perihelion Passage, 1843, Feb. 27*652, Munich mean time. Perihelion Distance 0-0056343 Long, of the Perihelion 189° 51' 25" Inclination 40 29 37 Long, of the Ascending Node .... 353 0 59 Motion retrograde. The following observations and elements of the comet, given by M. Carlini, Director of the Royal Observatory of Milan, are extracted from an Italian Gazette : — 1843. Mean Time. Right Ascension. Declination. Longitude. Latitude. March 19. 29. 30. h m 7 37 8 14 8 14 43 33 58 30 59 38 o / —9 31 —6 52 —6 38 s o / 1 8 18 1 24 34 1 25 51 o / —25 5 —26 32 —26 33 The above observations, together with one made at Munich on the 23rd of March, and another made at Padua, on the 24th, furnished the following elements : — Perihelion Passage, Feb. 27, 5h mean time of Milan. Perihelion Distance 0'1542 Long, of the Perihelion 243° 33' Long, of the Node 353 45 Inclination 38 0 Motion retrograde. In the Guiana Herald (city of Georgetown) of March 30, 1843, appeared a notice of the comet, dated Demerara, March 25, and signed J. Bamber, with observations of its distance from neighbouring bright stars ; the most important of which are as follow : — " Saturday, March 18*, at 7h 14m, the nucleus was brilliant; the coma, body and tail, very transparent. h m o i ii At 7 23 Sirius and the Nucleus, Apparent Distance 55 56 0 7 28yOrionis ... ... ... 40 16 7 7 45 Aldebaran ... ... ... 35 11 0 " Saturday, March 19. Appearance as before. The evening was beautiful. * Some of the dates in these Demerara observations are evidently erro- neous.— Edit' Phil. Mag. 154 Intelligence and Miscellaneous Articles. At h m o J /' t 7 7 a Orionis and Nucleus, Apparent Distance 47 0 0 7 11 y Orionis 9 , 38 14 0 7 14 Rigel • • • 32 32 9 7 17 Aldebaran • • • 32 2 0 7 22 Sirius • • • 55 9 0 Sunday, March 29. t 7 5 Rigel and Nucleus, Apparent Distance . . 0 / II 26 56 30 7 11a Orionis 38 4 0 7 22 Sirius 45 13 0 7 33 Aldebaran 26 32 0 7 57 Sirius 44 25 0 At " Monday 27. The nucleus very faint, as also the body and tail. h m o / / At 7 33 Rigel and Nucleus, Apparent Distance... 21 0 0 8 3 Procyon ... ... 52 50 0 " It appears that the comet was first seen in this colony on March 3." The newspaper containing the above account was received by the Astronomer Royal, and communicated to the Society by him*. XX. Intelligence and Miscellaneous Articles. ON THE VARIATION OF GRAVITY IN SHIPS' CARGOES IN DIF- FERENT LATITUDES. To the Editors of the Philosophical Magazine and Journal. Gentlemen, IN your valuable publication for April last (S. 3. vol. xxii. p. 326), you kindly inserted an article of mine entitled " On the Effect of the Variation of Gravity on Ships' Cargoes in different Latitudes." On turning to my manuscript, I find the article there headed, " On the Variation in the Weight of Ships' Cargoes in different Latitudes." As weight and gravity are not exactly synonymous, perhaps this title is less ambiguous than that which was printed ; but be that as it may, a very cursory perusal of the article is quite sufficient to show that its design was to exhibit the variation in iveight of cargoes in different places through which a ship may be supposed to pass. The table adverted to in your note showed the weight of the burden of dif- ferent vessels in each degree of latitude, they having a given tonnage in the latitude of London. Whatever may be the merits or demerits of the little article, I wish there to be no mistake ; the article states the circumstance that suggested it'. The table was constructed pur- posely to show how the weight of a body varies, supposing it to be carried through different latitudes ; without the table the communi- cation was rather incomplete, but as no room could be found to squeeze it in, it is useless to say more about it. Your Correspondent K. K., in the present (June) Number (vol. xxii. p. 503), in adverting to my communication, says, " the author * These communications relative to the Comet will be continued in our next. Intelligence and Miscellaneous Articles. 155 appears to Lave forgotten that two scales are commonly used in weighing goods, and that the weights in both must be equally af- fected by the ' variation of gravity.' ' I suppose I may take it for granted that your Correspondent read the article as well as its title ; if he did, I think he must have per- ceived its design, and if so, may not I ask, " Suppose I did forget the two scales in forming that communication, what then ? " What have two scales to do with the matter ? Besides, two scales are not absolutely necessary. Perhaps K. K. has seen large parcels weighed in coach-offices, &c. by being suspended to a piece of mechanism having a moveable indicator that points out the weight on a dial- plate. Now were this apparatus, and a heavy weight suspended to it, carried from London to Madras, does K. K. maintain that the in- dicator would point to the same figure at each place ? If I read his comment correctly it implies that such would be the case. I affirm that it would not, and beg to leave the question for your readers to settle. Your Correspondent also says, " a ton of any kind of goods weighed at the King's beam in London, and shipped for Madras, will on ar- riving there counterpoise a standard ton weight as it did before shipment, unless an addition or subtraction of weight has taken place during the voyage." I suppose this means if a ton of goods be put into one scale in London and a standard ton weight be put into the other scale, they will not only counterpoise each other at London, but in every other latitude ; a truism which, no doubt, is quite correct and very sage, and probably was intended to smash my unfortunate communication all to pieces. But your Correspondent has apparently omitted to consider what power supports the beam whilst the bodies are thus counterpoising each other. Some philosophers, it is said, suppose the earth to rest on an elephant, the elephant on a tortoise, and the tortoise on nothing : K. K.'s theory of counterpoising appears to be nearly similar. The scales support the goods and standard ton, and the King's beam supports the scales, but the beam hangs upon no- thing. If, however, two scales be attached to the King's beam sus- pended in the usual manner, a ton of goods be put in one scale and a standard ton in the other, perhaps K. K. will admit that the centre of the beam sustains two tons weight at London ; but does he mean to say that the centre of the beam would have to sustain the same pressure if the whole were carried to Madras ? I deny that it would, and here again beg to refer the point to the decision of your readers. The table that I sent indicated how this pressure varies in different latitudes : if K. K. can prove that the weight of a body is the same in all latitudes, he can show that I am in error, but I must see his proof before I can admit its validity. If two pendulums accurately beat seconds at London, their vibrations will be isochronous ; if they are suspended and made to oscillate at Ma- dras, will your Correspondent assert that they will vibrate each once in a second at that place ? This question is not irrelevant to the subject under consideration : if K. K. can prove that a body weighs 156 Intelligence and Miscellaneous Articles. the same at Madras that it does at London, he can also show that the vibrations of the same pendulum will be performed in the same time at each place. In forming the little table that I sent to you, I thought there was something novel in its showing how the weight of a body varies in each degree of latitude ; at all events it was new to me ; but that the weight of bodies does vary when they are carried into different lati- tudes, was I thought a recognised fact admitting of no dispute. Thus Newton, Principia, lib. iii. prop. 20, prob. 4, has " Invenire et inter se comparare pondera corporum in terra? hujus regionibus diversis." Having discussed the problem, he says, " Unde tale confit Theorema; quod incrementum ponderis pergendo ab sequatore ad polos, sit quam proxime ut sinus versus latitudinis duplicate, vel quod perinde est, ut quadratum sinus recti latitudinis." This problem would seem to have some reference to the subject, but Newton appears to have for- gotten the scales. The 227th question in the Leeds Correspondent is, " To find how much lighter the cargo of an East India ship, burden 1000 tons, will be at the equator than when she left the port of London." Two solutions were inserted ; they agree very nearly with the di- minution shown in my table. The accomplished editor states that true solutions were also sent by Messrs. Godward and Riley, names quite familiar to readers of mathematical periodicals. The editor however does not remind his correspondents that they have for- gotten the scales. I fear I have occupied too much of your valuable space, but I have been anxious to remove all ambiguity from my meaning. If I am in error, I hope I have shown no wish to conceal it. I am solicitous that your readers, without much trouble, should be enabled to form their own judgement upon the point under discussion : in addition to this, your Correspondent honoured my very trifling communication with an exposition. I trust I have been equally attentive to his pro- duction : but, upon the whole, I am sorry that the title of the article referred to was not more distinct ; and I regret it the more, because after all my endeavours to clear up the matter, I am obliged to con- clude my remarks quite in doubt as to whether that somewhat dubi- ous title did not mislead your Correspondent, or whether he had not altogether forgotten to make himself at all acquainted with the sub- ject before he wrote the comment that'was published in the last (June) Magazine. This too is a point which I must beg to refer to the judgement of your readers. I remain, Gentlemen, Your very obedient Servant, June 15, 1843. '. J. J. ON OLIVILE. BY MONS. A. SOBRERO. Olivile, discovered and analysed in 1 81 G by M. Pelletier, is very easily obtained by first digesting the powdered resin of the olive- tree in aether, afterwards dissolving the residue in boiling alcohol, and allowing it to crystallize by cooling after filtration. It is easily freed from the resinous matter by which it is rendered impure by washing it on a filter with cold alcohol, which dissolves but very Intelligence and Miscellaneous Articles. 1 57 little of it, and leaves it quite white. By re-dissolving and again crystallizing, it is obtained in small brilliant radiating crystals. Olivile is readily soluble in alcohol and in water, and crystallizes from either solution ; it also dissolves, but in small quantity, in aether, and in the volatile and fixed oils. Olivile possesses, like lithofellic and silvic acids and some other substances, the .property of fusing at different temperatures when crystallized and when amorphous. When crystallized its fusing point is 248° F. ; it assumes by this operation a resinous aspect, and neither gains nor loses in weight ; on cooling it does not lose its trans- parency, and splits without re-assuming its crystalline structure ; its melting point is then about 1 5 8° F. When it is dissolved in alcohol and re-crystallized, its original fusing point of 248° F. is again assumed. Olivile may be either anhydrous, monohydrated, or bihydrated ; the anhydrous is obtained by crystallizing it in anhydrous alcohol, or by fusing the olivile crystallized from water. Its composition is re- presented by C28 H18 O10. Olivile crystallized in water, and pressed between folds of filter- ing paper until it becomes pulverulent and dry to the touch, contains two equivalents of water ; it then has the composition indicated by the formula C28 H20 Ol*. Olivile by indirect means may be combined with oxide of lead ; the salt obtained is represented by an equivalent of anhydrous oli- vile and two equivalents of oxide of lead. The composition of olivile, stated by M. Pelletier, does not agree with any of those above stated : he gave its composition atomically as CI4H9 O2, and the composition in 100 parts as — Carbon 63-84 Hydrogen 8*06 Oxygen 28-10 100- No one of the three analyses above described agrees with this statement. — Journ. de Pharm. et de Chem., Avril 1843. ON SOME NEW COMBINATIONS OF CYANOGEN. BY MONS. A. MEILLET. The peculiar manner in which cyanogen acts towards iron, by forming two very stable acids with it, leads to the supposition that it is not the only metal with which cyanogen is capable of combining. In fact, some German chemists, and Gmelin among others, have dis- covered three new compounds, which are platino-cyanogen, cobalto- cyanogen, and chromo- cyanogen, and afterwards the hydrogenated acids analogous to ferro-hydrocyanic acid, and several other metallic salts. The processes employed were somewhat complicated, and they have not continued their experiments. The method which M. Meillet employed is, he says, simple, and there may be procured by it a great number of perfectly definite compounds ; the author states, as this inquiry requires much time and care, he shall on the present occa- sion give merely the principal characters of these salts, reserving their analyses for a future opportunity. 158 Intelligence and Miscellaneous Articles. Auro-cyanogen. Auro-cyanide of Potassium. — This salt is obtained by adding a perfectly neutral and saturated solution of chloride of gold to cyanide of potassium. On evaporation and on the cooling of the solution, the salt crystallizes in very white scales, of a pearly lustre ; the chloride of potassium and the excess of cyanide of potas- sium remain in solution. This salt gilds much better than those now employed in the arts. Platino-cyanogen. Platino-cyunide of Potassium. — Dcebereiner, who discovered this body, prepares it by heating to redness a mixture of equal parts of spongy platina and ferrocyanide of potassium. The residual mass is to be washed, and the undecomposed ferro- cyanide is to be obtained first by crystallization, and afterwards the platino-cyanide remaining in the solution, crystallizes when that is concentrated. This process is a long one, and it is difficult to pro- cure a pure salt. M. Meillet prepares it by adding concentrated chloride of platina to a saturated solution of cyanide of potassium ; there is immediately formed a precipitate of chloride of platina and potassium mixed with cyanide ; it is to be heated to ebullition, and then it redissolves with strong effervescence and disengagement of carbonate of ammonia. It may be supposed that, in this case, the cyanide of platina which is formed reacts like an acid on the atom of cyanate of potash (always contained in this cyanide of potassium), and sets free cyanic acid, which, by absorbing three atoms of water, is converted into bicarbonate of ammonia. Cyanic acid being C2AzqO, with three atoms of water H603, there will be formed an atom of bicarbonate of ammonia, C2 O4, Az2 H6. After the complete solution of the precipitate, the platino-cyanide of potassium crystallizes in blue needles, which are variegated by re- flected and yellow by transmitted light. Cupro -cyanogen. Cuprocyanide of Potassium. — This is prepared by dissolving either cyanide of copper, or carbonate of copper with heat in cyanide of potassium and evaporation ; on cooling the salt crystallizes in fine white needles. When, after having poured very concentrated hydrocyanic acid on hydrate of barytes, carbonate of copper is added, it dissolves with strong effervescence, and the liquor assumes a carmine-red tint of extraordinary intensity. On rapidly evaporating the solution, it is gradually decolorated, so per- fectly indeed, that on treating the residue with cold water, cupro- cyanide of barium is obtained entirely colourless ; the cause of this colour was found to be derived from the formation of a considerable quantity of murexide or purpurate of ammonia; M. Meillet endea- voured, but unsuccessfully, to explain the reaction to which its formation was owing, seeing that this body contains a large quantity of hydrogen. Once or twice he found some rudiments of crystals spontaneously formed, which had the colour of cantharides wings, a tint which sufficiently characterizes it. This solution of cupro- cyanide of barium, evaporated to dryness, moderately heated, and then treated with water, leaves a residue of carbonate of barytes. On adding a dilute acid, as the hydrochloric, to the cupro-hydrocya- nate and purpurate of barytes, purpurate of copper is precipitated, hydrocyanic acid is evolved, and hydrochlorate of barytes only re- Meteorological Observations. 159 mains in solution. This purpurate [of copper] is a powder of a fine deep violet colour. The red salt of barytes, treated with sulphate of soda, yields sulphate of barytes, and there remains a mixture of pur- purate and hydrocyanate of soda, which separate very well by spontaneous evaporation. The purpurate collects on the edges of the capsule ; it crystallizes like cauliflowers, and of a fine crimson colour unalterable in the air. The cuprocyanate of sodium remains at the bottom of the capsule in the form of small fine needles, which are also unalterable. Argento-cyanogen. Argento- cyanide of Potassium. — This salt cry- stallizes in tables analogous to those of chlorate of potash ; it is ob- tained by dissolving to saturation cyanide of silver in cyanide of potassium ; the solution is to be filtered, evaporated, and crystallized. Argento-hydrocyanic Acid.— -This is prepared by dissolving cyanide of silver in cyanide of barium, and precipitating the barytes with sulphuric acid ; it is a yellowish acid of considerable stability, pos- sessing the smell of hydrocyanic acid ; it is very weak, but still it combines very well with alkaline bases ; it acts upon carbonates with greater difficulty. Hydrargyro-cyanide of Potassium. — This salt is analogous to the preceding, and is prepared in the same manner ; it is white, very soluble, and assumes the form of small granular crystals. Similar compounds may be formed with a great number of other salts, as those of cobalt, nickel and cadmium. These the author proposes to de- scribe when he gives the analyses of those already mentioned. — Journal de Pharm. et de Chimie, Juin 1843. METEOROLOGICAL OBSERVATIONS FOR JUNE 1843. Chiswick. — June 1. Cloudy and fine. 2. Rain : dense clouds: boisterous, with rain at night. 3. Cloudy and line : clear. 4. Very fine. 5. Fine : heavy show- ers : clear. 6. Showery. 7. Fine : rain. 8. Cloudy : showery : boisterous, with heavy rain at night. 9. Cloudy and windy : boisterous, with showers and bright sunshine at intervals. 10. Fine : rain. 11. Cloudy and fine. 12. Hazy clouds: rain. 13. Heavy rain. 14. Foggy: cloudy : foggy at night. 15. Hazy : fine. 16— 18. Very fine. 19. Overcast. 20. Cloudy. 21, 22. Very fine. 23. Cloud- less, with bright sun. 24. Slight haze : fine. 25. Densely overcast. 26. Very fine. 27. Sultry, with hot dry air. 28. Cloudy and fine. 29,30. Overcast anil fine. — Mean temperature of the month about 4° below the average. Boston. — June 1. Cloudy : rain early a.m. 2, 3. Cloudy : rain p.m. 4. Fine : rain p.m. 5,6. Fine. 7. Cloudy. 8,9. Windy: rain early a.m. 10. Windy. 11. Cloudy: rain p.m. 12. Windy. 13. Windy: rain p.m. 14, 15. Fine. 16. Fine : curious halo round the sun 2 to 4 p.m. 17, 18. Cloudy. 19, 20. Windy. 21—23. Fine. 24—28. Cloudy. 29. Windy. 30. Cloudy. Sandwich Manse, Orkney. — June 1. Bright: damp. 2. Cloudy : drizzle. 3. Rain : showers. 4. Cloudy. 5. Bright : clear. 6. Bright : cloudy. 7. Cloudy : clear. 8. Rain: clear. 9. Damp: drizzle. 10. Showers. 11. Showers: damp. 12. Bright: cloudy. 13. Cloudy: fine. 14. Fine. 15 — 17. Fine: warm. 18 — 20. Cloudy. 21. Showers : cloudy. 22. Clear : cloudy. 23. Cloudy: drizzle. 24. Bright : fine. 25. Bright : clear. 26. Bright : cloudy. 27, 28. Cloudy. 29. Drops : showers. 30. Cloudy : damp. ■Applegarth Manse, Dumfries- shire. — June 1. Wet all day. 2. Slight showers : warm. 3. Wet nearly all day. 4. Fair and cold. 5. Bain all day. 6. Fair, but cloudy. 7. Rain : thunder. 8. Rain. 9. Showers. 10. 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I tj> .-) ^i CO CO • ) CN N»tO "^ -^ Ol © tO CO —• OS tO © C-l ' « © « 00 © ( i*r©towww^waw©NTi"T)i«o« IMCN^NWCTNCHriNWCNCNINWWWWl (N -^ N<© C0'-,C0tO'^'»OOl»CtMC0C0>--'NiflnOCDOH',1'OJ1,MOOSaDM«o ^NNOSKJ w n o> OlOSOsCCtO I-N.OSQ0 3SOS© ©©©©y ~* NNtptptp T}«©^—'OsOStptOt^ Os3s3l3sOsOS3s3s 3s '3s © ©©©©©© 3* 3i 3S3s3S3l©©©3s3l3S3l3S WiCCT«ON"5tO^N'*©NOOsN1< W«COtO00Q0-HC0^O3»flW 3stO OS ©3s3Sl^««'*-t,t>>ntO-f*^*C«C0-fl^»0i0«©C0tNCN*f»O©«C|->lCN & g*&0)i^&^^&&~ ~ ? ? ? V V ^^K*™ *P !>T *?* T* ? ? ^*^P 91 ">Ol3S3s3l3l3s3s3s© ©©©©©©3S3S3S 3S3S3S©© ©© ©OS3S3s ""'"ICSCNCOCOCOCOCOtN'NOl eoQCS 9 .z©©©©©©3!< C0C^ . -. . : Series 1 and 3|non.electrified surf< ^.^J difference +145 Definitive difference + 0"*50. I wished to control this result by another process, by sub- stituting a secondary for a direct electric tension. A copper vessel supported by a light tripod of wood was filled with olive oil, a Leyden jar was placed in the centre of the liquid, the exterior coating of which was in contact with the vessel and the interior connected with the machine. A rod of brass terminating on one side by a chain which descended upon the ground, on the other side presented a ball a little distance from the copper vessel in order to allow this complex appa- ratus to become charged. The machine was put in motion in such a manner that the deviation of the electroscope indi- cated a constant tension. Two series of observations gave 9 for 27° of cooling. Height of barometer . . 0m*7218 Interior temperature . . +16b 8C Exterior hygrometer . . 82° Numbers of the order Mean time of cooling 1° C. of the of the Series. Electrified Surface. Non-electrified Surface. 1 28"*70 27"*96 2 26 *48 26 *33 Mean ... 27 -590 , 27 *145 Definitive difference + 0''*445. Lastly, I wished to examine the case of porous bodies. The method which I adopted as the most simple and the least incorrect, after various trials, consists in placing some hollow cylinders of wood, such as oak and poplar, in the centre of a thin metallic grating, (that of a calorimeter of Lavoisier and Laplace) but wider by three quarters of an inch, placed on the wooden tripod near the machine. The cylinders were made of a single piece without varnish and provided with a 262 Prof. Wartraann on the Cooling of Electrified Bodies. cover pierced at its centre with an opening destined to receive the thermometer. Five of these apparatus were filled with boiling water and submitted to examination. Here is a re- sult, as an example, for 15° of cooling: — Mean time of cooling 1° C. of the Nature of Inter. Exter. Electrified Non-elect, the Wood. Barom. Temp. humid. Surface. Surface. Oak . 0m*7113 + 19°'l 100° 7l"'60 69"'27 Poplar 0 -7 174 + 19-0 90 66 "86 67*73 Mean ... 69 -23 68 -50 Definitive difference + 0"*73. I attribute the coincidence of sign of the definitive differ- ences to a fortuitous circumstance which would disappear by combining a greater number of series, although it is in favour of the duration of cooling of the electrified surface, in the examples already mentioned. Moreover, these differences are of so slight a kind that they may be reckoned amongst the possible, nay, I may say probable, errors of observation. This nullity of influence of the electro- static state of the porous or metallic parietes by which a calorific radiation is brought about at the time of its cooling, reminds us of the re- ciprocal indifference of electricity and of light when one of the two fluids produce a chemical action *. It tends to a con- clusion contrary to the opinion of some physiologists, that the electric state, whether of the human body or of the atmosphere, has no influence on the loss of animal heat in a given time, and consequently none on the ceconomy of the general state of health, nor on the functions of respiration and of digestion, which are perhaps the only sources of this heat f. In my experiments on organic parietes there has never been any ex- udation of liquid on the exterior ; a change in the chemical na- ture, and therefore in the temperature of this liquid, is not then to be expected; nor must we look for phaenomena of evapora- tion and of cooling, still less for internal lesions, the probable or certain existence of which had been alleged in more than one case by a skilful physicist %. # Archives of Electricity, vol. ii. p. 596. [ante, p. 254.] f See the remarks of M. Dumas on M. Dulong's researches on Animal Heat, and on the correction to be made of the coefficient of the calorific power of hydrogen. — Annates de Chimie et de Physique, 3me Ser. t. viii. p. 180. (June 1843.) % Peltier's memoir on different kinds of fogs, SS. 28-30. Mem. de VAcad. de BruxeUes, t.xv. ; Annates de Chimie et de Physique, 3me Ser. t. vi. p. 129. (Oct. 1842.) [ 263 ] XXXII. On the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat. By J. P. Joule, Esq.* "I T is pretty generally, I believe, taken for granted that the -*- electric forces which are put into play by the magneto- electrical machine, possess, throughout the whole circuit, the same calorific properties as currents arising from other sources. And indeed when we consider heat not as a substance, but as a state of vibration, there appears to be no reason why it should not be induced by an action of a simply mechanical character, such, for instance, as is presented in the revolution of a coil of wire before the poles of a permanent magnet. At the same time it must be admitted that hitherto no experi- ments have been made decisive of this very interesting ques- tion ; for all of them refer to a particular part of the circuit only, leaving it a matter of doubt whether the heat observed was generated, or merely transferred from the coils in which ■ the magneto-electricity was induced, the coils themselves be- coming cold. The latter view did not seem to me very im- probable, considering the facts which I had already succeeded in proving, viz. that the heat evolved by the voltaic battery is definite-^ for the chemical changes taking place at the same time; and that the heat rendered "latent" in the electrolysis of water is at the expense of the heat which would otherwise have been evolved in a free state by the circuit % — facts which, among others, seem to prove that arrangement only, not gene* ration of heat, takes place in the voltaic apparatus ; the simply conducting parts of the circuit evolving that which was pre- viously latent in the battery. And Peltier, by his discovery that cold is produced by a current passing from bismuth to antimony, had, I conceived, proved to a great extent that the heat evolved by thermo-electricity is transferred § from the heated solder, no heat being generated. I resolved therefore to endeavour to clear up the uncertainty with respect to mag- neto-electrical heat. In this attempt I have met with results which will I hope be worthy the attention of the British As- sociation. * Read before the Section of Mathematical and Physical Science of the British Association, meeting at Cork on the 21st of August 1843; and now communicated by the Author. f Phil. Mag. S. 3. vol. xix. p. 275. j Memoirs of the Literary and Philosophical Society of Manchester, 2nd series, vol. vii. (part 2.) p. 97. § The quantity of heat thus transferred is, I doubt not, proportional to the square of the difference between the temperatures of the two solders. I have attempted an experimental demonstration of this law, but owing to the extreme minuteness of the quantities of heat in question, I have not been able to arrive at any satisfactory result. 264 Mr. Joule on the Calorific Effects Part I. — On the Calorific Effects of Magneto-Electricity. The general plan which I proposed to adopt in my experi- ments under this head, was to revolve a small compound electro-magnet, immersed in a glass vessel containing water, between the poles of a powerful magnet; to measure the elec- tricity thence arising by an accurate galvanometer ; and to ascertain the calorific effect of the coil of the electro-magnet by the change of temperature in the water surrounding it. The revolving electro-magnet was constructed in the fol- lowing manner: — Six plates of annealed hoop-iron, each eight inches long, 1| inch broad, and y^th of an inch thick, were insulated from each other by slips of oiled paper, and then bound tightly together by a ribbon of oiled silk. Twenty-one yards of copper wire y^th of an inch thick, well covered with silk, were wound on the bundle of insulated iron plates, from one end of it to the other and back again, so that both of the terminals were at the same end. Having next provided a glass tube sealed at one end, the length of which was 8| inches, the exterior diameter 2*33 inches, and the thickness 0*2 of an inch, I fastened it in a round hole, cut out of the centre of the wooden revolving piece a, fig. 1. The glass was then covered with tinfoil, excepting a narrow slip in the direction of its length, which was left in order to interrupt magneto-electrical currents in the tinfoil during the experiments. Over the tinfoil small cylindrical sticks of wood were placed at intervals of about an inch, and over these again a strip of flannel was tightly bound, so as to of Magneto-Electricity. 265 inclose a stratum of air between it and the tinfoil. Lastly, the flannel was well varnished. By these precautions the in- jurious effects of radiation, and especially of convection of heat in consequence of the impact of air at great velocities of rota- tion, were obviated to a great extent. The small compound electro-magnet was now put into the tube, and the terminals of its wire, tipped with platinum, were arranged so as to dip into the mercury of a commutator*, consisting of two semicircular grooves cut out of the base of the frame, fig. 1. By means of wires connected with the mer- cury of the commutator, I could connect the revolving electro- magnet with a galvanometer or any other apparatus. In the first experiments I employed two electro-magnets (formerly belonging to an electro-magnetic engine) for the purpose of inducing the magneto-electricity. They were situated with two of their poles on opposite sides of the revol- ving electro-magnet, and the other two joining each other beneath the frame. I have drawn fig. 2 representing these Fig. 2. electro magnets by themselves, to prevent confusing fig. 1. The iron of which they were made was one yard six inches long, three inches broad, and half an inch thick. The wire which was wound upon them was ^ th of an inch thick ; it was arranged so as to form a sixfold conductor a hundred yards long. The following is the method in which my experiments were made : — Having removed the revolving piece from its place (which is done with great facility by lifting the top of the frame, and with it the brass socket in which the upper steel pivot of the revolving piece works), I filled the tube containing the small compound electro-magnet with 9| oz. of water. After * I had matte previous experiments in order to ascertain the hest form of commutator, but found none to answer my purpose as well as the above. I found an advantage in covering the mercury with a little water. The steadiness of the needle of the galvanometer during the experiments proved the efficacy of this arrangement. 266 Mr. Joule on the Calorific Effects stirring the water until the heat was equably diffused, its tem- perature was ascertained by a very delicate thermometer, by which I could estimate a change of temperature equal to about jx^th of Fahrenheit's degree. A cork covered with several folds of greased paper was then forced into the mouth of the tube, and kept in its place by a wire passing over the whole, and tightened by means of one or two small wooden wedges. The revolving piece was then restored to its place as quickly as possible, and revolved between the poles of the large electro- magnets for a quarter of an hour, during which time the de- flections of the galvanometer and the temperature of the room were carefully noted. Finally, another observation with the thermometer detected any change that had taken place in the temperature of the water. Notwithstanding the precautions taken against the injurious effects of radiation and convection of heat, I was led into error by my first trials : the water had lost heat, even when the tem- perature of the room was such as led me to anticipate a con- trary result. I did not stop to inquire into the cause of the anomaly, but I provided effectually against its interference with the subsequent results by interpolating the experiments with others made under the same circumstances, except as regards the communication of the battery with the stationary electro-magnets, which was in these instances broken. And to avoid any objection which might be made with regard to the heat, however trifling, evolved by the wires of the large electro-magnets, the thermometer employed in registering the temperature of the air was situated so as to receive the influ- ence arising from that source equally with the revolving piece. I will now give a series of experiments in which six Daniell's cells, each 25 inches high and 5| inches in diameter, were alternately connected and disconnected with the large station- ary electro-magnets. The galvanometer, connected through the commutator with the revolving electro-magnet, had a coil of a foot in diameter, consisting of five turns of copper wire, and a needle six inches long. Its deflections could be turned into quantities of current by means of a table constructed from previous experiments. The galvanometer was situated so as to be out of the reach of the attractions of the large electro-magnets, and every other precaution was taken to render the experiments worthy of reliance. The rotation was in every instance carried on for exactly a quarter of an hour. of Magneto-Electricity. Series No. 1. 267 - — Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of 5 turns. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Loss or Gain. Before. After. Battery con- tact broken. Battery in connexion. Battery con- tact broken. Battery in connexion. J600 JGOO J600 }eoo O 1 0 0 21 0 0 0 24 0 54-69 54-67 54-61 54-65 0-19+ 0-20 + 0-24+ 023+ 54-90 54-85 54-88 54-85 54-85 54-88 54-83 54-92 0-05 loss 0-03 gain 0-05 loss 0-07 gain Mean, Battery in connexion. Mean, Battery con- tact broken. 1 600 1 600 22 30 0 0 ... 0-21 + 0-21 + ... ... 0-05 gain 0-05 loss ' Corrected Result. } 600 22° 30' = 0-177* of cur. mag.-elect. 0-10 gain Having thus detected the evolution of heat from the coil of the magneto-electrical apparatus, my next business was to confirm the fact by exposing the revolving electro-magnet to a more powerful magnetic influence ; and to do so with the greater convenience, I determined on the construction of a new stationary electro-magnet, by which I might obtain a more advantageous employment of the electricity of the battery. Availing myself of previous experience, I succeeded in pro- ducing an electro-magnet possessing greater power of attrac- tion from a distance than any other I believe on record. On this account a description of it in greater detail than is abso- lutely necessary to the subject of this paper will not I hope be deemed superfluous. A piece of half-inch boiler plate iron was cut into the shape Fi2. 3. * Throughout the paper I have called that quantity of current unity, which, passing equably for an hour of time, can decompose a chemical equi- valent expressed in grains. 268 Mr. Joule on the Calorific Effects represented by fig. 3. Its length was thirty-two inches; its breadth in the middle part eight inches; at the ends three inches. It was bent nearly into the shape of the letter U, so that the shortest distance between the poles was slightly more than ten inches. Twenty-two strands of copper wire, each 106 yards long and about one-twentieth of an inch in diameter, were now bound tightly together with tape. The insulated bundle of wires, weighing more than sixty pounds, was then wrapped upon the iron, which had itself been previously insulated by a fold of calico. Fig. 4 represents, in perspective, the electro- magnet in its completed state. Fig. 4. In arranging the voltaic battery for its excitation, care was taken to render the resistance to conduction of the battery equal, as nearly as possible, to that of the coil, Prof. Jacobi having proved that to be the most advantageous arrangement. Ten of my large Daniell's cells, arranged in a series of five double pairs, fulfilled this condition very well, producing a magnetic energy in the iron superior to anything I had pre- viously witnessed. I will mention the results of a few experi- ments in order to give some definite idea of it. 1st. The force with which a bar of iron three inches broad and half an inch thick was attracted to the poles, was equal, at the distance of T]^th of an inch, to 100 lbs; at ^th of an inch to 30 lbs; at half an inch to 10^ lbs. ; and at one inch to 4 lbs. 13 oz.* 2nd. A small rod of iron three inches long, weighing 148 grs., held vertically under one of the poles, would jump through an interval of If inch; a needle three * The above electro-magnet being constructed for a specific purpose, was not adapted for displaying itself to the best advantage in these instances. On account of the extension of its poles (three inches by half an inch) many of the lines of magnetic attraction were necessarily in very oblique direc- tions. Theoretically, circular poles should give the greatest attraction from small distances. of Magneto-Electricity. 269 inches long, weighing 4 grains, would jump from a distance of 3^ inches. Having fixed the electro-magnet just described with its poles upwards, and on opposite sides of the revolving electro-magnet, I arranged to it the battery often cells, in a series of five double pairs, and, experimenting as before, I obtained a second series of results. The galvanometer used in the present instance was in every respect similar to that previously described, with the exception of the coil, which now consisted of a single turn of thick copper wire. Great care was taken to prevent, by its distance from, and relative position with the electro-magnet, any interference of the latter with its indications. No. 2. Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of one turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Before. After. Loss or Gain. Battery in connexion. Battery con- tact broken. Battery in connexion. Battery con- tact broken. Battery in connexion. Battery in connexion. Battery con- tact broken. Battery in connexion. J600 J600 1 600 1-600 J600 J600 J600 1-600 22 0 0 0 24 0 0 0 24 45 22 0 0 0 21 20 58-93 59-60 59-55 59-45 58-30 57-74 58-35 58-73 Mean, Battery in connexion. Mean, Battery con- tact broken. 600 600 22 49 0 0 017+ 0-40 + 1-23+ 019+ 005+ 0-32+ 0-49+ 0-78+ 58-20 60-02 59-90 59-78 57-35 57-28 58-83 58-83 60-00 59-98 61-67 59-50 59-35 58-83 58-85 60-20 1-80 gain 0-04 loss 1-77 gain 0-28 loss 2-00 gain 1-55 gain 0-02 gain 1-37 gain 0-51 + 0-36+ 1-70 gain 010 loss Corrected Result. 1 600 22° 49' = 0-902 of cur. inag.-elect. 1-84 gain The corrected result is obtained as before, by adding the loss sustained when contact with the battery was broken, to the heat gained when the battery was in connexion. I have in the present instance, however, made a further correction of 270 Mr. Joule on the Calorific Effects 0o,04< on account of the difference between the mean differences 0°'51 and 0°'36. The ground of this correction is the result of a previous experiment, in which, by revolving the appara- tus at 94° in an atmosphere of 60°, the water sustained a loss of 70,6, or about one quarter of the difference between the temperature of the atmosphere and the mean temperature of the water. With the same electro-magnet, but using a battery of only four cells, arranged in a series of two double pairs, by which I expected to obtain about half as much magnetism in the iron, the following results were obtained : — No. 3. In the next experiments a battery of ten cells in a series of five double pairs was used for the purpose of exciting the large stationary electro-magnet. But, dismissing the galvanometer and the other extra parts of the circuit, I connected the ter- minal wires of the electro -magnet together, so as to obtain the whole effect of the magneto-electricity. The resistance of the coil of the revolving electro-magnet being to that of the whole circuit employed in the experiments No. 2 as 1 : 1*13, and 0*902 of current being obtained in those experiments, I ex- pected series. of Magneto-Electricity. 271 to obtain the calorific effect of 1*019 in the new No. 4. pi © t— 1 Revolu- tions of Electro- Magnet per minute. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Loss or Gain. Before. After. Battery in connexion. Battery con- tact broken. Battery in connexion. j-600 j-600 j-600 5685 57-37 57*52 0-61 — 0-12+ 1-08 + 54-98 57-48 57*48 57-50 57*50 59-73 0 2-52 gam 0-02 gain 2-25 gain Mean, Battery in connexion. Mean, Battery con- tact broken. 1 600 Uoo ... 023+ 0-12+ ... ... 2-38 gain 002 gain Corrected Result. J600 1-019 of cur. mag.-elect. 2-39 gain It seemed to me very desirable to repeat the experiments, substituting steel magnets for the stationary electro-magnets hitherto used. With this intention I constructed two mag- nets, each consisting of a number of thin plates of hard steel, — an arrangement which we owe to Dr. Scoresby. My metal was, unfortunately, not of very good quality, but nevertheless an attractive force was obtained sufficiently powerful to over- come the gravity of a small key weighing 47 grs., placed at the distance of three-eighths of an inch. The following re- sults were obtained by revolving the small compound electro- magnet between the poles of the steel magnets. In order to obtain the whole calorific effect of the steel mag- nets, I now, as in Series No. 4, connected the terminal wires of the revolving electro-magnet, and interpolated the experi- ments with others in which that connexion was broken. The resistance of the coil of the revolving electro-magnet being to the resistance of the whole circuit used in the experiments marked No. 5 as 1 : 1*44, and 0-236 of current electricity being obtained in those experiments, I expected to obtain in the present series the calorific effect of 0*34 of current mag- neto-electricity. 272 Mr. Joule on the Calorific Effects No. 5. < to - I— i Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of 5 turns. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Loss or Gain. Before. After. Circuit complete. Circuit broken. Circuit complete. Circuit broken. Circuit complete. 1-600 J600 1-600 J600 J600 o I 26 0 0 0 29 0 0 0 27 0 59-72 59-82 59-95 59-58 59-65 0 o-o 020- 041 — 0-12— 025- 59-73 5970 5955 59-52 59-40 59-70 59-55 59-53 59-40 59-40 003 loss 0-15 loss 0-02 loss 0-12 loss 0 Mean, Circuit complete. Mean, Circuit broken. 1 600 1 600 27 20 0 0 ... 0-22- 016- ... 0-016 loss 01 35 loss Corrected Result. J600 27° 20' = 0-236 of cur. mag.-elect. 0-10 gain No. 6. W Revolu- tions of Electro- Magnet per minute. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Loss or Gain. Before. After. Terminals joined. Terminals separated. Terminals joined. Terminals separated. J600 J600 J600 J600 59-07 59-07 58-96 58-88 0-20- 022- 020- 0-18- a 58-82 58-92 58-75 58-78 58-92 58-78 58-78 58-63 010 gain 014 loss 003 gain 0-15 loss Mean, Terminals joined. Mean, Terminals separated. I 600 1 600 ... 0-20- 0-20- ... 0-065 gain 0-145 loss Corrected Result. 1-600 0-34 of cur. mag.-elect. 021 gain of Magneto-Bledricity. m Although any considerable development of electrical cur- rents in the iron of the revolving electro-magnet was prevented bjf its disposition in a number of thin plates insulated from each other, I apprehended that they might, under a powerful in- ductive influence, exist separately in each plate to such an extent as to produce an appreciable quantity of heat. To as- certain the fact, the terminals of the wire of the revolving electro-magnet were insulated from each other, while the latter was subjected to the inductive influence of the large electro- magnet excited by ten cells in a series of five double pairs. The experiments were interpolated with others in which con- tact with the battery was broken. As we shall hereafter give in detail experiments of the same class, it will not be necessary to do more at present than to state that the mean result of the present series, consisting of eight trials, gave 0o,28 as the quantity of heat evolved by the iron alone. We are now able to collect the results of the preceding experiments so as to discover the laws by which the develop- ment of the heat is regulated. The fourth column of the following table, containing the heat due to the currents cir- culating in the iron alone, is constructed on the basis of a law which we shall subsequently prove, viz. the heat evolved by a bar of iron revolving between the poles of a magnet is propor- tional to the square of the inductive force. Column 5 gives the heat evolved by the coils of the electro-magnet alone. No elimination is required for the results of series Nos. 5 and 6, because in them the iron of the revolving electro-magnet was subject to the influence of the steel magnets in the interpo- lating, as well as in the other experiments. Table I. <*« c O 01 CO x H 1 3 c'>-t u a~ a Heat actually evolved. s s . .2 c o ■% u oi c *-* U 01 as I n 13 o> 1 B E o O Squares of Num- bers proportional to those in co- lumn 2. Heat due to Vol- taic Currents of the intensities given in col. 2. «W 1 c; si* el No. 1. 0-177 o-io 0-02 0-08 0062 0-040 0053 No- 2. 0-902 1-84 0-28 1-56 1-614 1-040 1-386 No. 3. 0-418 0-45 009 0-36 0-346 0-224 0-299 No. 4. 1-019 2-39 0-28 2-11 2060 1-327 1-769 No. 5. 0-236 010 0 010 0-109 0071 0091 No. 6. 0-340 0-21 0 0-21 0-229 0-148 0-197 1. 2. 3. 4. 5. 6. 7- Phil. Mag. S. 3, Vol. 23. No. 152. Oct. 1843. 274 Mr. Joule on the Calorific Effects On comparing the corrected results in column 5 with the squares of magneto-electricity given in column 6, it will be abundantly manifest that the heat evolved by the coil of the magneto-electrical machine is 'proportional [ceteris paribus) to the square of the current. Column 7, containing the heat due to voltaic currents of the quantities stated in column 2, is constructed on the basis of three very careful experiments on the heat evolved by passing currents through the coil of the small compound electro-magnet. I observed an increase in the temperature of the water equal to 50,3, 5°*46, and 5°*9 respectively, when 2*028, 2*078, and 2' 145 of current voltaic electricity were passed, each during a quarter of an hour, through the coil. Reducing the first and second experiments to the electricity of the third according to the squares of the current, we have 5°-93, 5°*82 and 5°-9 for 2-145 of current. The mean of these is 50,88, a datum from which the theoretical results of the preceding and subsequent tables are calculated. But in comparing the heat evolved by magneto-, with that evolved by voltaic electricity, we must remember that the former is propagated by pulsations, the latter uniformly, Now since the square of the mean of unequal numbers is always less than the mean of their squares, it is obvious that the magnetic effect at the galvanometer will bear a greater proportion to the heat evolved by the voltaic, than the mag- neto-electricity; so that it is impossible to institute a strict comparison without ascertaining previously the intensity of the magneto-electricity at every instant of the revolution of the revolving electro-magnet. I have not been able to devise any very accurate means for attaining this object: but judging from the comparative brilliancy of the sparks when the com- mutator was arranged so as to break contact with the mer- cury at different positions of the revolving electro-magnet with respect to the poles of the stationary electro-magnet, there appeared to be but little variation in the intensity of the magneto-electricity during f of each revolution. The re- maining ^ (during which the revolving electro-magnet passes the poles of the stationary electro-magnet) is occupied in the conversion of the direction of the electricity. In the experi- ments all flow of electricity during this 4 is cut off by the di- visions of the commutator. In illustration of this I have drawn fig. 5, in which the direction and intensity of the mag- neto-electricity are represented by ordinates A#, &c, perpen- dicular to the straight line ABCDE; the intermediate spaces B C, CD, &c, represent the time during which the electricity is wholly cut off by the divisions of the commutator. of Magneto-Electricity. 2 75 Were A x x1 B, &c. perfect rectangles, it is obvious that the heat due to a given deflection of the galvanometer would be Fig. 5. K | of that due to the same deflection and an uniform current, and column 8 of the table would contain exact theoretical results. But as this is not precisely the case, the numbers in that column are somewhat under the truth. Bearing this in mind in the comparison of columns 5 and 8, it will, I think, be admitted that the experiments afford decisive evidence that the heat evolved by the coil of the magneto- electrical machine is governed by the same laws as those which regulate the heat evolved by the voltaic ap- paratus ; and exists also in the same quantity under compa- rable circumstances. Although very little doubt could exist with regard to the heating power of magneto-electricity beyond the coil, I thought it would nevertheless be well to follow it there, in order to render the investigation more complete : I am not aware of any previous experiments of the kind. I immersed five or six yards of insulated copper wire of ^nth of an inch diameter in a flask holding about 12 oz. of water. The terminals of the wire were connected on one hand with the galvanometer of five turns and on the other with the com- mutator, and the circuit was completed by a wire extending from the galvanometer to the other compartment of the com- mutator. The revolving electro-magnet was now subjected to the inductive influence of the large electro-magnet excited by ten cells in a series of five double pairs, and rotated at the rate of 600 revolutions per minute during a quarter of an hour. The needle of the galvanometer, which remained as usual pretty steady, indicated a mean deflection of 32° 40' = 0*31 of current: and the heat evolved was found to be 0°*46, after the correction on account of the temperature of the surround- ing air had been applied. Another experiment gave me 0°*4 for 0-286. The mean of the two is 0°*43 for 0*298 current magneto-electricity. By passing a voltaic current from four cells in series through the wire, I found that 2*02 of current flowing uniformly evolved 120,0 in a quarter of an hour. Reducing this to 0*298 of cur- T2 27d Mr. W. Brown on the Storms of Tropical Latitudes. fent We have ((t^\ x 125 = 0°-2Gl. The product of this by | (on account of the pulsatory character of the magneto- current) gives 0o,34-8, which, as theory demands, is somewhat less than the quantity found by experiment. [To be continued.] XXXIII. 0?i the Storms of Tropical Latitudes. By William Brown, Jan. [Continued from p. 217 and concluded.] ''l^HE storms of the tropics and of temperate regions, though thus referable to the same source, have yet some marked dif- ferences. The principal of these are : — the greater violence of the former ; the isolation of each individual storm ; the less extent of each particular portion of it, and the much greater extent and regularity of its progressive motion ; and the more rapid though less depression of the barometer. It may seem difficult at first to account for the violence of tropical hurricanes, but the difficulty disappears when we cease to compare the force of the upper current with that of the lower which sweeps oyer the earth, where the friction upon the surface prevents its gaining a great velocity by soon putting alimit to its acceleration. But as at the beginning of the hurri- canes which arise in the region of the trade-wind the lower cur- rent has not effected the change corresponding to that of the upper one, both therefore flowing in the same direction, the effect of friction must be so slight that we may almost disregard it ; as we may do also in other portions of the zone of the tropics, where a permanent reversal of the currents is effected; be- cause it must be supposed that the upper and lower currents of the atmosphere are separated from each other by an in- terval of calm air; therefore the upper current when confined to the upper strata of the atmosphere, subject as it is from the constant decrease in temperature it meets with to an ac- celerating force, may attain a very great velocity, more espe- cially in the former regions, before the effect of friction is sufficiently powerful to put a limit to its acceleration. Thus as it matters little whether the difference of tempera- ture, by which the wind acquires force sufficient to give the velocity of a hurricane notwithstanding the resistance of the air which it must displace, exists between columns of air nearly adjacent, or at the distance of many degrees of lati- tude, there seems no difficulty in conceiving the difference to be sufficiently great. The comparative exemption of the upper current from fric- Mr. W. Brown on the Storms of Tropical Latitudes, 277 tion may also be deduced from observation, being shown by its effect on the mean height of the barometer, as already ob- served in a former paper, though it is probable that amongst the causes there given as combining to produce this effect, due prominence was not given to this one ; for we find that the mean height of the barometer at latitude 32° is one-tenth of an inch above that at latitude 22° ; in opposition to the effect of the centrifugal force of the earth's rotation. Now as the greater part of this distance is within the zone of the trade-winds, the principal cause must be the excess of the in- flux of the upper current; the lower one being retarded by friction, to which the former is not exposed. But we have another instance more striking than this. In some compara- tive observations of the height of the barometer during dif- ferent seasons, inserted by W. C. Redfield in the American Journal of Science, vol. xxxviii. p. 267» it appears that the mean height of the barometer at Canton is 30*246 inches in winter, and 29*974- inches in summer : now Canton is situated in about latitude 23°, thus much nearer the northern verge of the monsoons than the southern : now the north-east mon- soon (or the trade-wind) blows in winter, and the south-west monsoon in summer ; thus, as the upper currents are of course the opposite of these, Canton is near the influx of the upper current in winter and near its egress in summer, and hence the barometer stands 0*272 inch higher in the former season than in the latter* . * The influence of the change in the direction of the currents is even greater than this, for omitting the months during which the monsoons change, the difference of pressure is increased to about one-third of an inch ; the amount which it is necessary to reduce the elasticity of the upper current in order to counteract the effect of friction upon the lower. In strict accordance with this variation are those of high latitudes, which are the opposite of those of the monsoons; for it appears from the obser- vations just quoted, that at Newfoundland, latitude 49°, the summer pressure is 0145 inch greater than the winter. The effect of friction upon the lower current, and that of the opposition given to it by the falling of the upper one being the same, — to cause in one part an accumulation of air and in another a deficiency, the accumulation will be in polar regions, and the deficiency in high latitudes ; and as these currents are of so much greater force in winter than in summer, their influence will of course be greatest in the former season; hence this deficiency of pressure is greatest in high lati- tude during winter, and the greater pressure of those near the pole ought to be at the same time increased. The apparent exception to this in the pressure at New York, which ac- cording to Redfield is 0*044 inch higher in winter than in summer, is pro- bably due to its vicinity to the northern verge of the region of the trade winds, and the position of the Gulf of Mexico with regard to the continent of America. The mean pressure in this country for the season is thus given by L. Howard :— summer, 29*883 ; autumn, 29833 ; spring, 29*800 ; winter, 29*778 (Climate of London, vol. i. p. 210.) The mean pressure in 278 Mr. W. Brown on the Storms of Tropical Latitudes. That this is the true explanation of this variation can scarcely, I think, admit of doubt ; it requires of course that the press- ure of the atmosphere near the southern confines of the mon- soons should vary simultaneously with that of the northern, but in the opposite direction, and that at the equator, or mid- way in the course of each monsoon, it should remain nearly stationary throughout the year; and also that the variation should be general throughout the zone of the tropics, because although the atmospheric currents in only some portions of it have the regular alternations of monsoons, they are everywhere more or less influenced both in force and direction by the movement of the sun in declination. I am not aware of any observations in the longitudes of India or China to enable us to answer the first of these questions with regard to the monsoons themselves, but the occurrence of the variations in the required order in the longitudes of the New World is shown by the observations given by Humboldt in his " Perso- nal Narrative;" the results of which with regard to this sub- ject, he thus states (English edit., vol. vi. p. 747) : — " It is in- teresting to compare the variations of the weight of the atmo- sphere in the vicinity of the two tropics. At Rio Janeiro (south latitude 23° 30') the extreme barometric mean of December and August, and at the Havannah (north latitude 22° 30'), that of September and January differs nearly 8 millimetres (0*315 inch), whilst at Bagota (north latitude 4° 30'), nearer the equa- tor, the monthly mean does not swerve 1| millimetre" (0*059 inch). And in a note to the above, these means are thus given : — "Rio Janeiro ; mean height in December, 337-02 lines (ther- mometer 25*7° Ct.); in August, 340-59 lines (therm. 22-1° Ct.); at the Havannah, in September, 761'23mm (therm. 28-8° Ct.); in January, 768*09mm (therm. 21-1° Ct.). Reduced to the temperature of zero (Cent.), the difference near the tropic of Capricorn is 8'3mm (0*327 inch), near the tropic of Cancer 7.9mm (0-311 inch)." But if this reasoning accounts for the violence of tropical storms, it also accounts for the less violence of those of high latitudes; because, as the south wind will sustain a loss of force by every descent, and as the north wind in the part of its course near its termination will frequently be an ascendino- current, and carry with it its motion from north, thereby retarding the progress of the air flowing in the opposite direc- tion; the frequent alternation of these winds upon the surface of the earth in high latitudes, prevents its attaining the force the regions of "variable winds" is, however, without doubt influenced by the prevalence of particular winds, but that this is not the sole cause of difference is very evident. Mr. \V. Brown on the Storms of Tropical Latitudes. 279 of tropical hurricanes, by checking the acceleration of the southern or upper current. The differences of the two descriptions of storms, with re- gard to the fall of the barometer and the extent of each parti- cular portion of the hurricane,are well compared by Professor Dove to those between a deep ravine with precipitous sides, and an extensive valley with gentle declivities ; a comparison however holding much more truly with regard to the views here taken, than to those adopted by Professor Dove in ad- vocating the hypothesis of a whirlwind*. It will be easily seen that these differences arise from the difference in the force of the wind. The more violent the wind the more rapid will be the fall of the barometer, but at the same time the resistance to the force of the wind will increase more rapidly also, and overcome it in less time than when the wind is less violent. The remaining differences are obviously referable to the same origin as those generally existing between the meteorological phenomena of these two divisions of the globe, — the great complexity of the causes which affect the distribution of heat and atmospheric vapour in temperate regions as compared with those of the tropics. Thus whilst in the latter each storm is generally one individual phasnomenon, the former are fre- quently visited by them in rapid succession, each succeeding one appearing before the subsidence of the last, and thus often preventing the regularityof the succession of the currents, here described as belonging to tropical gales and sometimes to these, being observed. An interesting observation regarding the locality of hurri- canes has been made by Col. Reid, which is the fact of the exemption from them of the region adjacent to St. Helena, whose position occurs on the line of least magnetic intensity, as drawn on Major Sabine's chart ; not however as Col. Reid appears to suggest, as pointing out the existence of a force not previously recognised as at work in the movements of the atmosphere, but as indicating the connexion between the lo- calities of storms and climate; Sir David Brewster having shown the relation existing between the isodynamic magnetic lines and the isothermal lines; both these series of lines agreeing in general in their deviations from the circles of la- titudes, the lines of greatest magnetic intensity following those of greatest heat. The dependence of the force of the wind on the relative difference of temperature of adjacent latitudes, has been before shown with regard to seasons; storms will be * Dove on the Law of Storms (Taylor's Scientific Memoirs, vol. iii. (part x.) p. 217). 280 Mr. W. Brown on the Storms of Tropical Latitudes. most violent therefore where this is the greatest ; and thus arises the great violence of the storms on the American coast, compared with that in general of British storms. If then I have been successful in my attempt to establish the views set forth in this essay, all the more important phasno- mena of the wind may be simply classed with those of the southerly and northerly breezes of our own climate, the various directions of the wind arising either from the simple deflection of one of the currents by the rotation of the earth, or from the collision of the two currents after being so deflected ; the barometer rising or falling, as the density of the one or the momentum of the other prevails. But there yet remains the ultimate step in this inquiry, to discover the immediate or proximate cause of the descent of the upper current at any particular time. The principal difficulty to be overcome seems to be, that the descending air is warmer, and therefore lighter than that pre- viously occupying its place ; there must therefore exist some cause capable of producing a descent of air in opposition to its density. Such a cause may perhaps be found in the dif- fusive tendency of aqueous vapour. There seems no reason to deny this property of perfect gases to the vapour existing, as it is now admitted, as an independent constituent of the atmosphere; and as the upper current contains the largest quantity of vapour, there will exist a tendency in the air of the higher and of the lower currents to intermix : according to the conclusions deduced by ThomasThompson (Phil. Mag. vol. iv. p. 321) from Prof. Graham's law of the diffusive force of gases, this force remains throughout all stages of the inter- mingling of the gases to be inversely as the square root of their densities. It would seem therefore in the present case to re- quire, in order that the upper air should be made to descend and the lower to ascend, that the quantities of vapour in the two currents (supposing the air of each to be of the same tem- perature) should be such, as to make the square root of the number expressing the density of the mixture of air and vapour of the lower current relatively to that of the higher, equal to the number expressing the density of the dry air of the same current relatively to that of the higher, at their real temperatures. This however would require too great a dif- ference to be allowed; but if the air itself does not at first descend, the vapour, by infiltrating through the particles of air, and arriving amongst comparatively cold air* will be partially condensed (perhaps the cause of the rain which so * The difference of temperature arising from the difference of elasticity of air of unequal elevations is here left out of consideration. Dr. Lyon Play fair on the Milk of the Cow. 281 frequently follows the change of the wind from north-east to south-east), and the latent heat emitted during the condensa- tion may raise the temperature of the air so as to diminish its density sufficiently to enable the diffusive force of succeeding portions of vapour to carry down some of the air of the upper current, which, by immediately checking the air flowing in the opposite direction by the force of its momentum, will be fol- lowed by another quantity of air to supply the want occa- sioned by the check; and thus when the difference in the quantity of vapour in the opposite currents is sufficient to cause a tolerably abundant flow of the vapour of the upper one into the strata of the lower, the upper current may, by the above process, gradually work its way to the surface of the earth. Although this hypothesis is offered as little more than a conjecture, observation has afforded me some rather striking instances of a change of wind from north to south immediately following a sudden dryness of the atmosphere ; and as rain so frequently occurs at the changing of the wind to south, it may receive some support from the results of some observations, inserted by Prof. Loomis in the American Journal of Science for October 1841, showing the frequent occurrence of rain very shortly after an unusual dryness of the air. It is not, however, proposed to the exclusion of other causes coopera- ting with it, as for instance an interruption of the lower cur- rent by a local elevation or depression of temperature, by which a deficiency of air would somewhere be produced; but that it is frequently opposed in its descent by the lower cur- rent, is apparently shown by the wind changing from north- east to south-east, the south wind being deflected by the force of that from north-east. * - XXXIV. On the Changes in Composition of the Milk of a Cow, according to its Exercise and Food. By Lyon Playfair, Ph.D., Honorary Member of the Royal Agricultural Society of England*. A S the principal object of this paper is to draw the atten- -** tion of practical men to the conditions which effect a change in their dairy produce, it has been written in a more elementary form than would have been done, had its purpose merely been to communicate facts to scientific chemists. The object of the Chemical Society is to examine the applications of chemistry to practice, as well as to assist in the advance- * Communicated by the Chemical Society ; having been read January 17th, 1843. 282 Dr. Lyon Playfair on the Milk of the Cow. ment of the abstract science. Many difficulties occur in the pursuits of a dairy farmer, which render his occupation pre- carious. Such difficulties arise entirely from an ignorance of the scientific relations of the practice in which he is engaged. I have endeavoured in the following paper to point out the causes which so often effect changes in the nature of his pro- duce. Boussingault and Lebel* instituted some experiments, with the view of proving that the composition of milk remains constant, when the food given to the cow contains the same amount of nitrogen : and their analyses established this fact, as far as regarded the casein in the milk ; although its other ingredients varied very considerably, according to the nature of the food. The mean of eight analyses described in the first part of their memoir, gives the following composition for the milk of a cow : — Casein 3'2 Butter 4*1 Sugar 5'1 Ashes 0-2 Water 87*4. The method employed by these chemists in their analyses did not differ from that used by Peligot in his examination of the milk of the assf. It consisted in treating the solid residue of a known weight of milk with aether, and afterwards with water. The loss in weight, after washing with aether, was estimated as butter, while that experienced by a similar treatment with water in- dicated the quantity of sugar; the dried insoluble residue being casein. The latter was incinerated, in order to obtain the ashes of the milk. There is an error in this method of analysis, which seems to have escaped the attention of Boussingault and Lebel. It consists in the neglect of the inorganic matters dissolved by the water. In washing with water the mixture of casein and sugar, all the soluble salts of the milk are dissolved. The insoluble salts remain in the residual casein, and these alone were obtained by its incineration, whilst those dissolved by the water were neglected. Consequently, in the analyses of Boussingault, the quantity of sugar in the milk is always too high, and that of the inorganic ingredients too low. The method of analysis employed in this paper was, with a few modifications, the same as the above. A weighed por- tion of milk, to which a few drops of acetic acid had pre- viously been added, was evaporated to dryness at the heat of * Ann. de Chim. et de Phys. lxxi. 65. f Ibid. lxii. 432. Dr. Lyon Playfair on the Milk of the Cow. 283 boiling water (212°). The solid residue was digested with aether, thrown upon a weighed filter, and well washed with hot aether. The mixture of sugar and casein remaining on the filter being again dried at 212°, indicated by its loss in weight the quantity of butter dissolved by the aether. The aethereal solution itself was evaporated to dryness, and con- sisted of butter with colouring matter, more or less intense, according to the character of the food. The mixture of casein and sugar was washed with hot water, and the casein remaining on the filter, after being dried at 212°, was weighed, then incinerated, its ashes determined and deducted from the weight of the casein. The solution of sugar, being evapo- rated by a heat of 212°, yielded a residue consisting of sugar of milk and of the soluble salts of the milk. This residue, after being weighed, was incinerated and its ashes deter- mined. These, deducted from the weight of the residue, yielded the amount of sugar, and added to the ashes of the casein, indicated the total amount of inorganic ingredients in the milk. The ashes of the filter were of course subtracted. The cow which was made the subject of the following ex- periments is of the breed of short horns. I am not aware of the number of days since she was delivered of her last calf. When the experiments were instituted, she was in good milking condition. In order to estimate the average amount of her milk, I measured it for several days previous to the experiments. During this time she subsisted upon after- grass ; the meadow being about half a mile distant from the cow-house. Morning's milk. Evening's milk. October 5 5 quarts 4^ quarts 6 5 4 ... 7 41 5 ... 8 5 4 9 5i 4 The weather was fine for the period of the year; but the nights being rather cold, on the evening of the 7th I directed that the cow should be driven to the house, and remain thei^e during the night. In the morning it was put out to grass, but brought back in the evening. On the evening of the 9th I commenced the analyses, and followed them up in consecutive days. In every case the specimen of milk analysed was taken from the milk-pail, after the cow had been thoroughly milked, and the milk well stirred. This precaution was necessary, because the separation of the cream from the milk takes place in part in the udder of the cow. Hence the milk 284 Dr. Lyon Play fair on the Milk of the Cow. last drawn from the udder contains much more cream than that first obtained*. 1st day. The cow, fed in the meadow upon after-grass during the day, was driven home to the cow-house in the evening. The milk then obtained amounted to four quarts. A portion of this was subjected to analysis. Specific gravity of milk, 1034". 1 1 *1 28 grammes of milk gave — In 100 parts. Casein ... •611 5-4 Butter ... •404 3-7 Sugar of milk . , •429 3-8 Ashes . . . •068 0-6 Water ... . 9-616 86*5 11-128 100-0 During the day the cow had considerable exercise. Before being milked, it had half a mile to walk from the meadow. The nourishment in after-grass being small compared with fresh grass, the animal had to eat a greater quantity than it otherwise might have done, and consequently had to traverse more ground in order to procure it. The exercise which it thus received, by increasing the number of its respirations, must have occasioned a greater supply of oxygen to the system. This oxygen, as we shall afterwards show, unites with the butter and consumes it; consequently less butter is contained in the milk of the cow than would have been the case had its pasture been rich grass. But, after being removed into the shed, less oxygen was respired, and the warmth of the house was equivalent to a cer- tain amount of unazotised foodf . The animal received nothing to eat during the night, and therefore the milk of the morn- ing must have been derived from the after-grass consumed during the day. This milk measured four and a half quarts. Specific gravity, 1032. 15*280 grammes yielded — In 100 parts Casein . . . . 0-610 3*9 Butter . . . . 0-864 5-6 Sugar of milk. . 0-468 3-0 Ashes . . . . 0-091 0-5 Water . . . . 13*247 87-0 15-280 100-0 * Schiibler says that the milk last drawn contains three times as much cream as that first procured. Dr. Anderson (Dickson's Practical Agriculture, vol. ii. p. 517) found the cream in the last cup of milk drawn from the udder, compared with that of the first cup, in the proportion of 16 to 1. f In this paper we take for granted that the leading features of Liebig's ' Animal Physiology ' are acknowledged as true. Dr. Lyon Playfaii* on the Milk of the CoWi M The butter, as we might have expected, is in larger pro- portion than in the previous analysis. The amount of casein is smaller. We shall defer the consideration of the causes which pro- duce a variation in the quantities of the latter constituent. 2nd day. The object of this day's experiment was to disco- ver whether an increase of butter would be procured by feeding the cow with after-grass in the stall. It refused, how- ever, to eat this food, and being removed from its companions, struggled for several hours to regain its liberty. To render it tranquil, a companion was introduced into the same stall, and it was then induced to consume 28 lbs. of good hay and •ed 3| 21 lbs. of oatmeal. The mil k of the : evening me quarts. Specific gi 22-684 grammes yielded — Casein . . . •avity, 1031. In 100 parts 1-124 4-9 Butter . . . 1-150 5-1 Sugar . . .- Ashes . . . 0-867 0-137 3-8 0-5 Water . . . 19-406 85-7 22-684 100-0 The milk of the morning amounted to 4 quarts ; but, owing to an accident, was not analysed. 3rd day. — A. The cow was kept in the shed, and consumed 28 lbs. of hay, 2| lbs. of oatmeal, and 8 lbs. of bean-flour. The milk of the evening amounted to 4 quarts = 10*34 lbs. Specific gravity, 1034. 23*160 grammes gave — In 100 parts. Casein . . . 1-262 5-4 Butter . . . 0-905 3-9 Sugar of milk 1-112 4-8 Ashes . . . 0-136 0-5 Water . . . 19-745 85-4 23-160 100-0 B. The quantity of milk obtained in the morning amounted to 41 quarts = 11*61 lbs. Specific gravity, 1032. 1 9-445 grammes of milk gave— In 10o parts. Casein . . . 0'758 3-9 Butter . . . 0-888 4-6 Sugar . . . 0-877 4-5 Ashes . . . 0-129 0*7 Water . . . 16*793 86-3 19-445 100*0 286 Dr. Lyon Playfair on the Milk of the Cow. 4th day. — A. The cow, kept in the stall as before, received this day 24 lbs. of potatoes (steamed), 14 lbs. of hay, and 8 lbs. of bean-flour. She gave in the evening 5 quarts of milk = 12-9 lbs. Specific gravity, 1033. 17*820 grammes of milk gave — in 100 parts. Casein . . . 0*707 3-9 Butter . . . 1*190 6*7 Sugar of milk 0*815 4*6 Ashes . . . 0*104 0*6 Water . . . 15-004 84-2 17-820 100*0 B. The milk of the morning amounted to 4 quarts = 10-32 lbs. Specific gravity, 1032. 19*641 grammes of milk yielded — In 100 parts. Casein . . . 0-535 2*7 Butter . . . 0-978 4*9 Sugar of milk 0-991 5*0 Ashes . . . 0-116 0-5 Water . . . 17-021 86-9 19-641 100-0 5th day. — A. The cow, kept as before, consumed 14 lbs. of hay and 30 lbs. of potatoes (steamed). She gave in the even- ing 5^ quarts of milk = 13' 18 lbs. Specific gravity, 1030. 18*141 grammes of milk yielded — in 100 parts. Casein . . ., 0'716 3-9 Butter . . . 0-845 4-6 Sugar of milk 0-713 3-9 Ashes . . . 0-099 0-5 Water. . . 15-768 87*1 quarts 18-141 100-0 B. The milk of the morning amounted to = 12-20 lbs. Specific gravity, 1030. 16-740 gn ammes yielded- In 100 parts. Casein • • . 0-600 3'5 Butter . , . 0-835 4-9 Sugar . . . 0-648 3-8 Ashes . . . 0-082 0-5 Water . . . 14-575 87-3 16-740 100-0 Before proceeding to the consideration of these experi- Carbon . . 38-47 Hydrogen . 4-20 Oxygen . 32-51 Nitrogen 1-26 Ashes . . 7'56 Water . . 16-00 Beans. Potatoes. Playfair. Boussingault. 38-24 12-30 5-84 1-74 33-10 12-04 5-00 0-32 3-71 1-40 14-11 72-20 Dr. Lyon Playfair on the Milk of the Cow. 287 ments, it is necessary that we should examine the composition of the various kinds of food given to the cow. The cow re- ceived, during the course of the experiments, grass, oatmeal, hay, beans, and potatoes. The following analysis exhibits the composition of these various substances. Hay. Oats. Boussingault. Boussingault. Playfair. 41-57 5-25 30-10 1-80 3-28 18-00 In a specimen of beans analysed by Boussingault, only 4 per cent, of nitrogen was found. But in the bean-flour, which I used in the experiments, there was as much as 5 per cent. It is obvious that if we multiply the quantity of nitrogen by 6^, the product will be the amount of casein or albumen in the various kinds of food ; and further, by deduct- ing this, together with the water and ashes, the remainder must indicate the quantity of unazotised matter. Albumen or casein. Unazotised matter. Hay . . 7-81 68'63 Oats . .11-16 67-56 Beans . . 31-00 51-18 Potatoes . 1-98 24-42 Finally, according to Liebig, good hay contains 1-56 percent. of a fatty or waxy substance. Braconnot found 0*70 per cent, of a similar substance in beans. Vogel found 2 per cent, in oats, and Liebig 0-3 per cent, in potatoes. Dumas, in an announcement to the French Academy, has lately advanced the theory, that the fat of animals is wholly derived from the fatty matter contained in their food. This opinion has been very ably combated by Liebig, who refers to an analysis of milk executed by Boussingault, and shows that much more butter was contained in it than could be accounted for by the fat in the food taken. As the theory of the formation of fat is of the first importance in the practice of dairy farming, we will shortly examine Dumas's theory with reference to the preceding experiments. 1 . On the 2nd day the cow received 28 lbs. of hay, which contains 0*436 lb. of fat and 2| lbs. of oatmeal, containing 0"050lb. of the same constituent. The cow produced (cal- culating according to its specific gravity) about 19 lbs. of milk, in which was 0*969 lb. of butter. But the food altogether 288 Dr. Lyon Playfair on the Milk of the Cow, Contained only 0-486 lb. of fat, so that 0*485 lb. of buttef nmst have been produced from other sources. 2. The food received by the cow on the 3rd day consisted of 28 lbs. of hay, 2^ lbs. of oatmeal, and 8 lbs. of bean-flour. 28 lbs. of hay contain . . . 0-436 lb. of fat. 2\ lbs. of oatmeal contain . 0-050 lb. of fat. 8 lbs. of beans contain . . 0*056 lb. of fat. In the food . . . . 0*542 lb. of fat. The milk of the evening amounted to 10*34 lbs., and con- tained 0*4 lb. of butter; that of the morning to 11*61 lbs., and contained 0*5 lb. of butter. The butter in the milk amounted, therefore, to 0*9 lb., of which only 0*542 lb. could possibly have been furnished by the food, assuming that the fat in the food could be converted into butter. 3. The cow received on the 4th day 14 lbs. of hay, 8 lbs. of beans, and 24 lbs. of potatoes. 14 lbs. of hay contain . . '. 0*218 lb. of fat. 8 lbs. of beans contain . . 0*056 lb. of fat. 24 lbs. of potatoes contain . 0*072 lb. of fat. 0*346 The evening's milk amounted to 12*9 lbs., and contained 0*86 lb. of butter; that of the morning to 10*32 lbs., and con- tained 0*50 lb. The cow, therefore, furnished during the day 1*36 lb. of butter. The fat in the food amounted only to 0*346 lb., and therefore 1*064 lb. must have been received from other sources. 4. On the 5th day the cow received 14 lbs. of hay and 30 lbs. of potatoes. 14 lbs. of hay contain . . . 0*218 lb. of fat. 30 lbs. of potatoes contain . 0*090 lb. of fat. 0*308 The milk of the evening amounted to 13*18 lbs., and con- tained 0*606 lb. of butter; that of the morning to 12*20 lbs., containing 0*597 lb. of butter. The cow, therefore, furnished 1*203 lb. of butter. The fat in the food amounted only to 0*308 lb. Hence 0*895 lb. of butter must have been pro- duced from other sources. From these calculations it must be obvious, that the butter in the milk could not have arisen solely from the fat contained in the food. Hence it must have been produced by a separation of oxygen from the elements of the unazotised ingredients of the food of the animal, in the manner pointed out by Liebig. We remark striking variations in the quantity of butter in the preceding analysis, and a similar result occurred in the Dr. Lyon Playfair on the Milk of the Cow. 289 experiments of Boussingault. In the milk of the first day there is a small amount of butter. The cow had been ex- posed in the field during the day, and hence required a greater quantity of unazotised food to support the heat of its body than would have been necessary had it been pro- tected from the cold. But in the evening it was removed into a warm and well-littered stall, where the warmth thus communicated was equivalent to a certain amount of food ; and hence we find, that the milk of the morning was consi- derably richer in butter. It is uniformly found to be the case, that a stall-fed cow yields more butter in its milk than one fed in the field. Besides the warmth of the shed, less butter is consumed by the oxygen of the air. In the stall the respirations of an animal are much less frequent than in the field, and consequently less oxygen enters into its system. The great care of all dairy farmers is to prevent an excess of this gas from entering the body. Hence the practice of milking in the field those cows which are distant from home, and of driving home to be milked only such cows as are close to the shed. The exercise required in walking home causes an increased play of the respiratory system, and therefore in- creases the amount of oxygen inspired. This oxygen unites with part of the butter and consumes it. The greatest care is taken by all good dairymen to allow the cows to walk home at their own pace, and never to accelerate it. By this means only a small amount of oxygen enters the system. When a cow is harassed and runs to escape from the annoyance, its milk becomes very much heated, diminishes in volume and in rich- ness, and speedily becomes sour. This is a fact well known to all dairymen. During running the cow respires a large quantity of oxygen. This unites with the butter, and the heat evolved by its combustion elevates the temperature of the milk and evaporates part of its water. The acetous fer- mentation is also induced, and cannot be restrained. For this reason cows are not turned into the fields in very hot weather, when the flies are apt to annoy them and produce restiveness. During such weather, it is not an uncommon practice to feed the cows in the stall during the day and turn them out to grass at night. By this means they are kept tranquil, and prevented from respiring a large amount of oxygen. There cannot be any doubt that the practice of stall-feeding cows during winter or in cold weather must conduce very much to the formation of butter ; but in sum- mer, when the pastures are rich and near the dairy, the slight exercise which they receive increases their health, and with it their appetite. They are thus induced to eat more Phil. Mag. S. 3. Vol. 23. No. 152. Oct. 1843. U 290 Dr. Lyon Play fair on the Milk of the Cow. food than they would do in the stall, and they consequently receive a greater flow of milk. The loss experienced by the greater absorption of oxygen is more than compensated for by the increased appetite of the animal. In these experiments it will be remarked, that potatoes were favourable both to the flow of milk and formation of butter. This quite accords with practical experience. They abound in starch, and therefore furnish the substance from which butter is formed. The increase of butter in the milk of the fourth day is very striking ; on this day 24 lbs. of potatoes formed part of the food. The butter is also in large quantity in the milk of the fifth day, though not so much so as in that of the fourth, though 6 lbs. of potatoes in excess were con- sumed. In these 6 lbs. of potatoes only li lb. of dry un- azotised matter were furnished, which could not compensate for 8 lbs. of beans (containing 4 lbs. of dry unazotised matter) which had formed part of the diet of the preceding day. The result is, therefore, exactly as might have been anticipated. When the food contained much starch, the sugar of milk in- creased in quantity as well as the butter. The large amount of butter in the milk of the second day is singular, and makes us regret the accident which happened to the milk of the morning and prevented its analysis. A remark has often been made to me by practical men (how far it is true I know not), that the milk of the morning is generally richer than that of the evening. As far as the limited number of analyses here given warrants any conclusion, there would seem to be some accuracy in this observation. The cause that it should be so is apparent: during the day, when exercise is taken, the number of respirations is frequent, and a large amount of oxygen enters the system — this is unfavourable to the for- mation of butter ; but at night, during sleep, the respirations are slow, and the amount of oxygen respired is trifling. Such a condition must favour the separation of oxygen from starch to supply the deficiency. All practical experience is against the theory of Dumas, regarding the formation of butter in milk, and of fat in cattle. In Scotland the system of stall-feeding cows is carried to a great extent. The Glasgow dairymen feed their cows in warm stalls, giving them malt refuse, a few pounds of beans, steamed tur- neps and potatoes, and as much pot ale (residuum after distil- lation, commonly called wash) as they will drink. The malt refuse consists of starch, gum, and a little saccharine matter, but it is not known to contain fat. This refuse is the principal food, and is very favourable to the production of butter, evi- dently from its great excess of unazotised matter. The beans Dr. Lyon Play fair on the Milk of the Cow. 291 furnish the nitrogenous matter, in which the other foods are deficient; and as they contain casein ready formed, they assist in the formation of the milk. Their value is fully appreciated by all Scotch dairymen, although their use is little known in this country. The pot ale contains sugar and alcohol, and therefore contributes to sustain the heat of the body. It thus enables the other food to be formed into butter. But its princi- pal use seems to be in diluting the secretions. Pure water does not readily enter the blood ; we know that it destroys the blood- globules. But acid water does not do so, and this pot ale is generally very acid. Hence it dilutes the secretions. The great object, therefore, in this kind of feeding, is to give the cows as much unazotised food as possible; and the food which is pre- ferred, consists of those very kinds in which fat exists in the least proportion. Porter and beer are well known to be favourable to the production of butter in the milk both of women and of cows; yet these fluids do not contain fat. We are, therefore, justified in asserting that practice is opposed to the theory of Dumas, but highly favourable to that propounded by Liebig. During stall-feeding we have it in our power to alter the composition of milk, even with respect to the casein. Thus in the second day the cow received in its food 2^ lbs. of albu- men, or of a substance of the same composition (28 lbs. of hay, 2^ lbs. of oatmeal). It produced 19 lbs. of milk, in which was 0*93 lb. of cheese. The next day it received 5 lbs., or double the quantity, of albumen in its food, and the milk, which amounted to 22 lbs., contained 1 lb. of casein*. Still theory would have led us to anticipate a larger increase than actually took place. The circumstance which favoured the produc- tion of casein in the milk of the first day will afterwards be considered. The cow received in the food given on the fourth day, 4 lbs. of casein and albumen (14 lbs. hay, 8 lbs. beans, 24 lbs. potatoes), and yielded 23 "22 lbs. of milk, which contained 0'75 lb. of casein. The fifth day she received considerably less albumen in her food, viz. 1»7 lb. (14 lbs. hay and 30 lbs. potatoes), but the amount of casein in the milk, though in less per centage than before, was equal in amount to the other, from there being a greater flow of milk. The milk amounted to 25 lbs., of which about 0*94 lb. was casein. Here, although the food did not contain much casein, it was such as to induce a great flow of milk, and the casein must have been derived from the albumen of the blood. Had the cow been continued on this food, there cannot be a doubt that the * Calculated according to the composition of the evening's milk, as that of the morning had not been analysed. U2 292 Dr. Lyon Play fair on the Milk of the Cow. quantity of casein in the milk must either have diminished, or the cow must have lost condition in giving this substance at the expense of its tissues. The value of these experiments is certainly very much dimi- nished by not being extended over a series of days on each kind of food. But in England, where the price of aether is so exorbitantly high, the expense of such experiments is a se- rious consideration for a private individual. As they were conducted under the same conditions with respect to tempe- rature and exercise, an indication of the effects produced by the various foods must have been obtained, although the final effects have escaped detection. Neglecting the second day, in which an abnormal increase of casein was produced by an accidental circumstance, we find the milk of the third day contained 5*4 per cent, of casein, that of the fourth 3*9 per cent., and of the fifth also 3*9 per cent. The food consumed on the third day contained a very large amount of casein, and this was immediately followed by an increased amount in the milk. Some peculiar cause fa- voured the flow of milk on the fifth day, in spite of the small quantity of albumen in the food ; the milk derived its casein from other sources. The milk of the second day contained 4*9 per cent, of casein, while that of the fourth day possessed only 3*9 per cent, of the same constituent, although on that day the cow had received 4 lbs. of albumen in its food, and on the former day only one half or 2 lbs. Such are the changes which constantly occur to the dairy farmer, and cause variations in the value of his milk, even when the conditions of feeding seem to be the same. It is for us to determine to what these seemingly discordant results are due. In experiments such as these, we must remember that the animal body is not a mere chemical laboratory, in which a chemist may operate as he pleases. But there is a power, — vitality, — superior to his, and it is only by its concurrence that the changes which he desires are effected. Now, on the second day the animal struggled violently to regain its liberty, and consequently expended much matter in the production of force. It is difficult to conceive that any waste of tissues can take place, without an alteration in their chemical composition. Still we cannot deny (in the present state of ourknowledge)]that an alteration in form might effect a waste, as well as a change in composition. We know little or nothing of the nature of secretion. All we know is, that certain glands have the power of appropriating particular parts of the organism or of food, and of producing fluids, which Dr. Lyon Playfair on the Milk of the Cow. 293 either perform some new functions in the system, or are sepa- rated from it; but we are entirely ignorant how these secre- tions are produced. Scherer has indeed pointed out that al- bumen may be converted into casein by digestion with caustic potash ; and it is possible that this may be the process em- ployed to form it in the organism. On this view, we might suppose that the waste of the tissues operated indirectly in its production. By their waste their alkaline constituents are libe- rated, and might act upon the albumen of the blood by con- verting it into casein. Be this as it may, there are many facts which induce us to believe that the waste of the tissues does favour the production of casein in the milk. The milk of a cow, fed in the stall, is not only absolutely but relatively poorer in casein than one fed in the field, where exercise in- creases the transformation of its tissues. During parturition all the muscles are thrown into a violent state of action. As the labour in a cow continues for many hours, there must be a great waste of tissues in the production of the force neces- sary to occasion these muscular exertions. Such being the case, if our view be correct there ought to be in the milk of a cow, immediately after parturition, an abundance of casein : and every one knows that such milk is quite thick with cheese. We are indebted to Boussingault for an analysis of the milk of a cow before the calf had been allowed to suck. He found it to contain as much as 1 5 per cent, of casein, while the milk of the same cow analysed a few days after its calving contained only 3 per cent, of the same substance ; therefore only one-fifth the quantity*. If then the waste of the tissues tends, directly or indirectly, to increase the amount of casein in the milk, then we are at no loss to understand why the milk of the second day should be unusually rich in casein. Beans contain 31 per cent, of casein ready formed. Hence it is that they have been found so practically useful in aiding the formation of the milk. The conditions necessary for the production of casein in the milk, are different from those which are favourable to the formation of butter. When butter is the principal object desired, the cow cannot be put upon too rich pastures. But in all cheese districts, it is agreed that poor land is best adapted for cheese. Land is called poor, not when the grass is deficient in nitrogenous bodies, but in constituents desti- * It might be objected to the view given, that the analysis of this milk indicates a very small amount of inorganic ingredients. Boussingault found only 0-3 per cent. To this it may be answered, that the alkalies which favoured the formation of casein are soluble, and therefore were neglected in Boussingault's analysis, by being included along with the sugar of milk. {Ann. de Ch. et de Phys. lxxi. p. 72.) 294 Dr. Lyon Playfair on the Milk of the Cow. tute of nitrogen. The " equivalent," as farmers term it, is higher; that is, the cattle are compelled to eat a greater quan- tity of poor than of rich grass, in order to sustain animal heat. They have also to traverse more ground to procure their food; this causes an increased respiration of oxygen and waste of the tissues. Hence the appetite of the animal is increased, and a larger quantity of food is consumed. If the view already given be correct, the waste of the tissues aids in the supply of casein to the milk. One great object in cheese-farms is to induce the cows to eat a large quantity of food, and for this purpose, in large farms, they are tempted with new pastures every day. The Cheddar, Cheshire and Stilton cheeses con- tain a considerable quantity of butter. In a celebrated cheese- farm, a few miles from Bridgewater, where Cheddar cheese is made in great perfection, I found it to be the practice (a prevalent one, I believe) to drive the cows in the morning to the pastures on dry sandy soil, and in the evening to those situated on soft peaty soil. The grass of the sandy soil being poor, the cows traversed considerable ground in procuring it. They therefore eat a quantity more than they would have done on rich land, where there is little exertion required in taking the food. By this means a large quantity of cheese was procured in the milk. But during the night they were allowed to feed on rich pastures, fitted for the formation of butter, and as the darkness prevented them from wandering, little oxygen was respired to consume the butter formed, or to prevent its formation. The milk of the evening and morn- ing being always mixed together in the preparation of the cheese, a proper proportion of both constituents was thus procured. In districts where inferior cheeses are manufac- tured, that is, in which the farmer depends upon his butter as much as upon his cheese, he is ignorant of the value of poor land. Thus it is that there is occasionally a contradiction amongst dairymen with respect to this point, though there is none with those who depend wholly on their cheese, and care little for the butter, except as a means of enriching the former. Chevallier's analysis of woman's milk (the only one of which I am aware) indicates a very small quantity of butter. As attention to diet and exercise must be very important to nurses, when we consider the trivial causes which produce a variation in the composition of milk, I was desirous of ascertaining whether the quantity of butter could be made greater than in the analysis given by Chevallier. Accordingly I selected a farmer's wife, a strong healthy female of twenty-eight years of age, who had been delivered of her third child. On the 19th day after her confinement she remained in bed, and thus di- Dr. Lyon Playfair on the Milk of the Cow. 295 minished the amount of oxygen respired, and was then fed upon gruel (oatmeal and water). On the 21st sufficient milk for analysis was procured. 23*945 grammes yielded— Casein . . . . 0-3695 1-54 Butter . . . . 1*0315 4*30 Sugar of milk . . 1*3770 5*75 Ashes . . . . 0*1270 0*53 Water . . . . 21*0400 87*88 23*9450 100*00 The butter in this milk was therefore quite equal to that in the milk of a cow. As the diet thus influences the compo- sition of the milk, may not the frequent occurrence of ricketty children in the higher classes of life be due to the circum- stance of the mothers living principally upon white bread — bread, therefore, from which phosphates have been in a great measure removed ? Had the woman been at her usual ex- ercise, it must of course have diminished. The milk of a woman possesses a very sweet taste, and is remarkable for its great amount of sugar of milk. In this and in other respects it closely resembles that of the ass. The following analyses exhibit the composition of the milk of various animals : — Woman. Ass. Cow. Casein . . . i Henry and Che. vallier*. 1-52 i Playfairf. 1-54 PeligotJ. 1-95 " > Henry and Che. vallier.* 1-82 i ■— » Bous. singault||. 32 Henry and Che. vallier*. 4-48 i Playfairf. 4-0 Butter . . . 355 4-30 1-29 o-ii 4-1 313 4-6 Sugar of milk 6-50 5-75 629 6-08 5-1 4-77 3-8 Ashes . . . 0-45 053 034 02 0-60 0-6 Water . . . 87-98 87*88 90-47 91-65 87-4 87-02 87-0 Before concluding this paper, I take the opportunity of making a few remarks to practical men on the mode of pre- serving milk, as this is a subject on which questions have been often sent to me. Milk consists of casein, of sugar of milk, and of certain salts dissolved in water, in which are suspended little globules of fat or butter. These globules are surrounded by a shell or skin, which is supposed (by Otto) to be coagulated casein. The soluble casein, being a nitrogenous body, is very apt to run into putrefaction. In summer it does not do so readily, because the temperature being elevated, the sugar of milk is converted apparently into grape sugar by the agency of lactic acid, then * Journal de Pharmacie, xxv. 333 et 401. f Supra. X Ann. de Ch. et de Phys. Ixii. 432. j| Ann. de Ch. et de Phys- lxxi. 65, § Average of analyses of the milk of a cow in the field. 296 Dr. Lyon Play fair on the Milk of the Cow. into alcohol, and the alcohol into acetic acid. These changes are induced by a primary action of oxygen upon the casein. This action is then imparted to the other constituents, the atoms of which being once set in motion, readily undergo the changes described. The acetic acid being formed by the agency of air on the alcohol, acts upon the soluble casein and coagulates it, or renders it insoluble. It is thus removed from the action of the oxygen of the air, and may be kept for some time without entering into putrefaction. Such are the changes which milk undergoes in summer, but they are quite different in winter. In winter the first action is that of oxygen upon the casein. The temperature is not sufficiently elevated to cause vinous fermentation. The decay of the casein generally passes over to putrefaction, that is, the atoms are transformed more rapidly than they unite with oxygen. A putrid smell now arises. Good butter cannot be made from milk which has under- gone this change. The cause is, that butter always contains a certain quantity of casein which it is difficult to remove. When incipient putrefaction has taken place, it cannot be arrested by ordinary means, and imparts itself to the bodies with which it is in contact. It is for this reason that the greatest part of the butter manufactured in winter has a rank putrid taste. The principal object in view in the preservation of milk in winter, is to prevent the commencement of this putrefaction. One method has been termed scalding the milk, and is gene- rally used in dairies. It consists in heating the milk until the oxygen of the air acts upon the casein, and forms a pellicle on its surface. The milk should then be left to perfect repose. The pellicle excludes the air from the soluble casein. The partial oxidation by which the pellicle was produced, is ef- fected at too high a temperature to enable the decay to pass into putrefaction. When this operation is skilfully performed, the milk remains quite good for four or five days. But there is a risk of failure in this process, and it is only adapted for small dairies. The best method, which I have seen used in practice with much success, seems to be to induce the acetous fermentation in the milk. For this purpose, the cream or milk, being placed in a proper vessel, should be surrounded with hot water. The heat which I find to answer best is from 100° to 110°. A cloth may be thrown over the whole to retain the heat, and as the water cools, it should be removed and reple- nished with hot water of the above temperature. In a few hours the cream acquires the smell and taste of vinegar. The changes which I have described above ensue. In large dairies Dr. Lyon Play fair on the Milk of the Cow. 297 a portion of this soured cream or milk maybe added to fresh cream or milk, which should be kept in a room possessing a temperature of 60°. By adding this soured cream to the fresh milk, we furnish an acid, by which the sugar of milk is converted into grape sugar. The curd then acts upon the grape sugar, and converts it into alcohol. The latter by oxi- dation becomes acetic acid, and thus the whole mass of milk is rendered sour, the casein coagulated, and therefore pro- tected from immediate putrefaction. The butter made from such soured milk is quite sweet and destitute of that rank taste which distinguishes our winter from summer butter. But if incipient putrefaction has once begun in the milk, all this will be of no avail, because it is communicated to the in- soluble casein. Milk perfectly fresh must therefore be used. Fresh milk soured in this way will last for many days, and give risings of cream for a considerable time. This practice, as far as I am aware, is not a general one, though it is well worthy of adoption. In summer of course no such operation is requisite, as it is done at a sacrifice of the skimmed milk. One great cause of the putrefaction in milk is the want of absolute cleanliness in the dairy. If a drop of milk fall on the table, it should be dried and washed off with care, for its putrefaction causes the evolution of a putrid gas, and this im- parts its state of putrefaction to the remainder of the milk. With respect to making butter, scientific explanations can be of little use to practical men. The theory of churning is very simple. By agitation, the globules of butter are broken, and made to unite together into a mass. The introduction of air during churning, aided by the heat at which the cream or milk is, occasions the formation of lactic or acetic acid, and this coagulates the casein, and thus assists the separation of the butter. In summer, when the heat prevents the ready co- herence of the butter, a quantity of cold spring water thrown in, after the butter-milk has formed, often effects the desired end. The temperature is thus depressed, the butter rendered solid and more coherent, while the air contained in the water aids in the formation of acid and coagulation of the casein. The only thing, in a scientific point of view, to attend to after the separation of the butter, is to free it from butter-milk or casein. If the casein be suffered to remain, putrefaction en- sues, and the butter acquires a rank putrid taste. Its sepa- ration is therefore of the first moment. The cause of the superiority of certain foreign butter, which retains its flavour and taste for a considerable time, is more due to its freedom from casein than to any mystery in its mode of preparation. [ 298 ] XXXV. Places of Saturn computed by Hansen's Formula. By S. M. Drach, Esq., F.R.J.S. To the Editors of the Philosophical Magazine and Journal. Gentlemen, TPHE new analytical methods proposed by M. Hansen having -*- of late attracted much attention, I have for some time employed myself in computing several places of Saturn rigor- ously from his formula; selecting for the dates those speci- fied in the Greenwich Observations for 1837-4-0, as the mean day of the monthly observations. M. Hansen having as- sumed the same elements as M. Bouvard (whose tables of Saturn are now used for the Nautical Almanac), we derive the great advantage of exactly testing the value of both methods by reference to observation. I have therefore made the com- putations for the London mean noons = Paris ones + 9m 21s,5 for the 21 dates of the annexed table, in the following man- ner:— The mean anomalies of Jupiter and Saturn gave the argu- ments for all M. Hansen's perturbations in longitude, to which adding M. Bouvard's Georgian part of the great equation, viz. — 34"'58 (sex.) sin {3n"t + 3e" —nt — e — 95Sr'08} and applying the sum tog' = Saturn's mean anomaly, there re- sulted the corrected anomaly, wherewith the equation of the centre and elliptical value of the radius vector was computed. M. Bouvard's tables furnished the perturbations produced by ]$, and adding the constant perih. long. 89° 8' 20", the sum gave the true perturbed longitude in the orbit from the mean equinox of 1800 = r;. After allowing for the reduction to the ecliptic, M. Bouvard's value of the precession = 0&r,01 5463 = 50"* 1001 (sex.) and the ephemeridal equation of the equinoxes (p. 266) were applied, whence the true longitude from the true equinox was ascertained, and its comparison with the Nautical Almanac value exhibited in column 3. The other two coor- dinates are exhibited in columns 6 and 9 in the same manner. The errors in Hel. lat. are immediately extracted from the Greenwich Observations, and likewise those in Hel. long, for 1837-39. The volume for 1840 being deficient in these, they were approximatively supplied as follows. The planet never being as far as lh 4m in Geo. R.A. from the solstitial colure, the variation in declination has little influence on the R.A. ; hence the effect of the small monthly average error in the latter on the Hel. long, could be found nearly by simple proportion: thus in No. 16, March 9 —March 8 = + 9s-40 in Geo. R.A. and + 108"'6 in Hel. long. Places of Saturn computed by Hansen's Formula. 299 823 .*. mean error in former = — 0S,823 produces — ■=— ^108"#6 9400 = — 9"'51 error in Hel. long. The accompanying table, which has been verified in se- veral particulars, shows that A — H in longitude is nearly Table. No. Hel. Long. Hel. Lat. Log. R.V. A— H. A-G. H-G. A-H. A- G. H — G. A-H. 1837. a a ;/ // o-oooo 1 Feb. 12. + 2161 + 2-52 -1909 + 13-50 -15-11 -28-61 —240 2 Apr. 13. +20-97 + 0-34 —20-65 + 12-99 -15-76 -28-75 —248 3 May 15. +21-92 + 1-31 —20-61 + 12-47 -15-48 -27-95 —251 4 June 14. Mean. + 20-16 + 0-54 -19-62 + 1206 -1519 -27-25 -243 +21-16 + 1-18 -19-98 + 12-75 -15-39 -28-14 -245 1838. 5 Feb. 12. + 19-14 -3-88 —23-02 + 9-66 — 16-12 —25-78 -249 6 Mar. 16. + 18-67 -2-93 -21-60 + 9-45 -13-72 -23-17 — 193 7 Apr. 16. + 19-00 -3-50 —22-50 + 9-25 -15-08 —24-33 —250 8 May 17- + 19-34 -2-95 —22-29 4- 9-02 -15-20 —24-22 —239 9 June 12. + 18-92 —3-91 —22-83 + 8-69 — 14-82 —23-51 —238 10 July 8. + 18-72 -3-93 —22-45 + 8-29 -14-30 -22-59 —221 Mean. + 18-97 -3-53 -22-50 + 9-06 -14-87 -23-93 -233 1839. 11 Feb. 25. + 2016 -5-66 —25-83 + 3-99 -13-99 -17-98 — 146 12 Apr. 19. + 18-14 -8-11 —26-25 + 4-55 -15-23 —19-78 — 124 13 May 18. + 18-15 -681 -24-96 + 4-13 -15-27 -19-40 — 109 14 June 18. + 18-36 —4.68 —2304 + 3-73 — 1460 — 18-33 -091 15 July 13. + 18-69 —4-75 -23-44 + 3-38 -14-67 — 1805 -086 Mean. + 1870 -600 -24-70 + 396 -14-75 —18-71 — 111 1840. 16 Mar. 9. + 1905 -9-51 -28-56 + 007 — 13-49 —13-56 + 051 17 Apr. 16. + 19-08 + 9-24 - 9-84 - 0-49 — 13-85 — 13-36 + 102 18 May 29. +20-40 + 9-27 — 11-13 — 1-18 -15-70 — 14-52 + 133 19 June 16. + 18-16 +3-65 — 14-51 — 1-35 — 15-25 — 13-90 + 150 20 July 17. +2002 +4-49 -15-53 — 1-79 — 14-90 — 13-11 + 168 21 Aug. 4. + 19-04 + 8-87 -1017 - 2-07 — 14-40 — 12-33 + 196 + 19-29 +4-34 -14-95 — 1-14 -14-60 -13-46 + 133 con stant, th e gener almea n being + 19"'4 2,adiffe >rencew hich an addition of I ° to the epoch of— 2845"-8. . sin {Bg'—Vg + 246°..) would nearly remove*. The differences in the latitude and log. * If the precession be taken as in Poisson's Mec. ii. p. 195 = 50"-2343 as on the moveable ecliptic, this would diminish the error A — H in long. 300 Geological Society. rad. vect. assume a periodic form ; and as a change of 1° in the long, occasions a change in the lat. ranging from — 55" to 35", another cause must be found for the discrepancy. Now the only considerable part affecting this subject is the term in t, which ranges from — 15"-213 in No. 1, to — 31"-000 in No. 21. These extremes agree with the nsr. A.i ... _.. Q10, . . r , 322°.23'\ , XG.O.J1' +0 8184/ism \vi + 3]2°.58'Jand + 0"-8184 t2l sm|r)21 -t 306o ^ 19, j- be assumed for those equations, i. e. if with the latter 309° and not 349° be the true epoch of M. Hansen's equation. S. M. Drach. London, 22nd June, 1843. XXXVI. Proceedings of Learned Societies. GEOLOGICAL SOCIETY. [Continued from p. 71-] May 4, A letter addressed to the President by Mr. Ick, F.G.S., on 1842. A some superficial deposits near Birmingham, was first read. While excavating that part of the New Junction Canal which passes through the valley of the Rea, at Saltley, a mile and a half north-east of Birmingham, the workmen at the depth of five feet came to a deposit of carbonaceous matter, consisting of compact peat, in which were imbedded rounded pebbles of white quartz, and branches as well as prostrated trunks of oaks, hazels and wil- lows, the former being occasionally upwards of six feet in length. The wood exhibited various stages of carbonization, some speci- mens being reduced to a soft state, while others, " consisting of oak, were scarcely so much changed as the timbers of the Royal George." The author did not observe an instance of coniferous structure. About 150 yards from the river the deposit is two feet and a half thick, and contains abundance of hazel-nuts. The horn of a stag, probably of the Cervus elephas, which was found there, measured from the base to the broken tip of the extreme antler one foot seven inches, and eight and a half inches around the base, and the brow antler was nine inches in length. At the distance of twenty yards, where the peat was mingled with gravel, the core of the horn of an ox was found, one foot in circumference at the base, and one foot eight inches long. At the bottom of the peat is generally a thin layer composed prin- cipally of angular particles of white quartz, beneath which occurs by i (from 4"'981 to 5"-447), and if we assume it = 50-3648, as on the fixed ecliptic of 1800, this diminution would rise to £ (from 9""824 to 10"774). Geological Society. 301 the usual marine drift of the district, the greater part of the boul- ders contained in it, consisting of Lickey quartz-rock ; and the whole rests on the new red sandstone. Above the carbonaceous bed is a stratum, from six to eighteen inches thick, of fine clay, frequently almost white, but in some instances of various shades of yellow and red. Upon the clay is occasionally a bed of coarse gravel com- posed of* the usual Lickey pebbles, and over it occurs a pale* red sand, which gradually passes upwards into a sandy vegetable soil. The average thickness of these overlying deposits is five feet. At a spot about 250 yards from the river, the place of the peat is occupied by a bed of gravel composed principally of boulders from eight to ten inches in circumference ; and above it lies the prevalent light-coloured clay eighteen inches thick. The next stra- tum, in ascending order, consists of very fine comminuted peat, with small fragments of hazel and oak twigs, the whole bearing the ap- pearance of a drifted mass. The highest bed, immediately under the vegetable soil, is composed of sandy clay, and is about seven inches thick. In some spots the lower vegetable deposit rests on a deeply orange-coloured, ferruginous clay, and where this has been re- moved, the action of water on the drift, Mr. Ick says, is very ap- parent, the larger pebbles standing in high relief exactly in the same manner as in the bottom of the present river, where a rapid current flows over the gravel. Mr. Ick has traced this peaty deposit in places along the banks of the river towards Birmingham, through Deritend, particularly at Vaughton's Hole, where it is eighteen inches thick. It has also been penetrated in making wells and culverts in the lower part of Dig- beth, and nuts and bones have been found there. The next communication read is entitled " A Postscript to the Memoir on the occurrence of the Bristol Bone-Bed in the neighbour- hood of Tewkesbury," by Hugh Edwin Strickland, Esq., F.G.S. Since the reading of the former communication (Phil. Mag. S. 3. vol. xxi. p. 540.) Mr. Strickland has ascertained that the bone-bed occurs at least ten miles further north, or at Defford Common, in Worcestershire, making a total range of 104 miles. At this locality are some old salt-works belonging to the Earl of Coventry, and the shaft, which was sunk about seventy years ago to the depth of 1 75 feet, was emptied a few months since of the brine with which it is wont to overflow. At the bottom of the shaft, which descends through the lias into the grey marl of the triassic series, but without reaching the red marl, is a tunnel that follows the dip of the strata for about 160 yards. The shaft, Mr. Strickland says, consequently intersects the horizon of the " bone-bed," and among the rubbish thrown out, he found considerable quantities of the peculiar white sandstone with bivalves (Posidonomya), shown in his former paper to represent in Worcestershire the bone- bed of Aust and Axmouth ; but he also found specimens of the sandstone charged with the same description of teeth, scales and coprolites so abundant at Coomb Hill and the localities just mentioned. 302 Geological Society. The occurrence of an abundance of pure salt water* within the area of lias, Mr. Strickland says, is an interesting phenomenon, and for a solution of it, he refers to Mr. Murchison's Account of the Geology of Cheltenham, p. 30. A paper on the high Temperature of Wells in the neighbourhood of Delhi, by the Rev. Robert Everest, F.G.S., was then read. The country around Delhi is remarkable for its great dryness; and if a line were to be drawn due west from the Jumna to the Indus, a distance of 400 miles, it would intersect no river, brook or spring, water being obtained only from wells. At Delhi these wells are generally about 35 feet deep ; 40 or 50 miles to the westward the depth is from eighty to ninety feetj and beyond that distance to Hauri, 95 miles, it increases to 150 feet. Mr. Everest did not visit the country further to the west, but he believes that the wells have a depth of 150 feet or more. The soil consists of a granitic alluvium, but the surface is covered in many places with saline efflorescences similar to those which the floods of the Jumna now leave behind them. The results of the author's observations are given in the following tables : — 1. Well at Delhi, 42 feet to the bottom. This table shows the amount of annual variation. Temp. Temp, of water, of ext. air, 1833. Nov. 12 79 Dec. 17 76 1834. Jan. 25 747 Mar. 2 76-8 Mar. 29 77 76 62 68 84 67 1834. Temp. Temp. of water. of ext. air May 12... .... 7°8-9 . 7% June 17... .... 80 . .... 86-5 July 25... .... 80-9 . .... 82-2 .... 81-3 . .... 92 .... 81-5 . Average temperature : water, 78-61 ; external air, 77-57. 2. Wells to the W.S.W. of Delhi, ten to fifteen miles apart, the first being the furthest, or 90 miles. 1834. Locality. Jan. Depth Depth to water, of water. Feet. Feet. Toolshaum 90 7 ... Baphoora 52 28 ... Dadnee 45 15 ... 20. Billoti 52 15 ... 22. Djuggur 44 5 ... 16. 17. 19. Total depth. Feet. .. 97 .. 80 .. 60 .. 67 .. 49 Temp. Temp, of of water, ext. air. 82 82 81 81 77 67 72 70 68 715 Average 70-6 80-6 General mean of twelve wells : depth, 96 feet ; temperature, 80°-2. 3. Wells situated to the west of Delhi. * An imperial gallon of the brine is stated to yield the following saline contents : — Chloride of sodium 58076 grains. Sulphate of lime 195-8 grains. Magnesia A trace. Dr Hastings' 's Paper in the Analyst, vol. ii. p. 384. The Rev. R. Everest on Wells near Delhi. 303 Dist.from Depth Depth rr. t 1 Temp. Temp. 1834. Locality. Delhi, to water, of water. * Fahr. of air. Miles. Feet. Feet. Feet. 0 o A riil4'}Bahadurghur,"2° 3° 3° 6° 75'2 76'2 „ 1. Samplah 35 69 19 88 81-5 90-5 „ 3. Moheim 65 96 39 135 82-8 95 „ 4. Moordahal 75 96 44 140 75 89-5 „ 5. Hausi 95 69 50 119 83-1 89 „ 7. Hausi 115 45 160 79-8 67 „ 9. Moheim 90 12 102 82 57 Average 115 799 The temperature of the water and air at Bahadurghur is the mean of two ob- servations taken at an interval of fourteen days. Respecting the last table Mr. Everest says, the irregularities in the temperatures may be explained by some of the wells being worked for the purposes of irrigation, and therefore supplied by a current of fresh water continually issuing from the ground ; whilst in those wells which were still, the surface of stagnant water exposed to the air was cooled by the evaporation dependent on so dry a climate. The general level of the country is said to be 800 feet above the sea, and the temperature of Delhi, as determined by the author from observations made during four years, to be 750,78, or 7t0,64> Fahr., taken as the mean between that result and another (73°*5) given in the * Gleanings of Science.' If to this 1°#8 were added for the depth of the wells (115 feet), according to the rule which holds good in Europe, the temperature would be 76°-44', or something less than that obtained by observation. Mr. Everest then proceeds to show, according to the formula of Mr. Atkinson*, that the temperature at the level of the sea, in the latitude of Delhi (28° 40'), should be 77°-84 (74°-64 + 3°'2 for the difference of 800 feet of altitude), and that the temperature of Sincapore, in the second degree of north latitude, is 80o,2, leaving, in comparison with that of the former locality, only 20,56 of temperature for above 26° of latitude. This discrepancy, he is of opinion, maybe partly explained by Sincapore being surrounded by the sea contiguous to the Pacific and Indian Oceans, and cooled by perpetual showers, and Delhi being in the midst of dry and burning plains. But, adds the author, the mean annual temperature of Cairo, in 30° north latitude, and situated in a dry and sandy continent, is not above 72°*5, leaving consequently yet a difference to be accounted for, and which he conceives may be owing to the tropical rains being limited west of the Indus to 23^° north latitude, but extending in India even beyond 30° of latitude. During the period in which the rain prevails, or from the 25th of June to the 15th of September, the south-west monsoon blows nearly from the equator and transports a large quantity of aqueous vapour ha- ving a temperature from 77° to 81°, or that of the rain as it falls and soaks into the earth, the evaporation being then very trifling. The quantity of rain during the other nine months is so small that it cannot counteract this effect, which, Mr. Everest says, may ac- count both for the high temperature of the surface, and for the tem- perature of the interior being greater than was to be expected. * Transactions of the Astronomical Society for 1826, vol. ii. p. 137 et seq. 304 Geological Society : — Mr. Lyell on the If this explanation be allowed, the author observes, it may easily be conceived that when a much greater portion of the globe was covered with water, and the evaporating surface consequently larger, currents of air charged with aqueous vapour prevailed still more, and modified the ancient climate even in still higher latitudes. In conclusion, Mr. Everest remarks, that Scandinavia presents another instance of the carrying power of fluids with respect to heat, the coast, and even the bays, being free from ice to the latitude of 71°, owing probably to a south-westerly current in the adjacent ocean j and he states, on the authority of persons who have win- tered at Spitzbergen, that south-west winds are usually accompanied by rain and thaw even in December and January. A paper was then read, "On the Tertiary Formations and their connection with the Chalk in Virginia and other parts of the United States," by Charles Lyell, Esq., V.P.G.S.* Having examined the most important cretaceous deposits in New Jersey, Mr. Lyell proceeded, in the autumn of 1841, to investigate the tertiary strata of Virginia, the Carolinas and Georgia, with a view to satisfy himself, first, how far the leading divisions of the tertiary strata along the Atlantic border of the United States agree in aspect and organic contents with those of Europe ; and, secondly, to ascer- tain whether any rocks containing fossils of a character intermediate between those of the cretaceous and the eocene beds really exist. The conclusions at which he arrived, from his extensive survey, are given briefly as follows : — 1. The only tertiary formations, which the author saw, agree well in their zoological types with the eocene and miocene beds of England and France j 2. he found no secondary fossils in those rocks which have been called upper secondary, and supposed to constitute a link between the cretaceous and tertiary formations. 1. Virginia. — The tertiary strata bordering the James River, Mr. Lyell says, have been well described by Prof. H. D. Rogers and Dr. Rogersf ; and, he adds, they are also noticed in Mr. Conrad's ex- cellent work on the tertiary strata of the United States. At Rich- mond, Mr. Lyell examined the remarkable bed of infusorial clay described by Prof. Rogers J, consisting of an impalpable siliceous powder derived from cases of microscopic animalcules. It varies in thickness from twelve to twenty-five feet, and is interposed between eocene greensands and miocene clays ; but Mr. Lyell agrees with Prof. Rogers in considering it as probably belonging to the former epoch. Similar eocene greensands, very much resembling the cretaceous greensand of New Jersey, occur at Petersburg, thirty miles south of Richmond, and are overlaid by a large deposit of miocene marls abounding in testacea different from those of the subjacent sands. Among the fossils of the latter deposit are a Venericardia scarcely distinguishable from V. planicosta of the London clay, also an Ostrea * For abstracts of a series of papers by Mr. Lyell and others on the geo- logy of North America, see present volume, p. 180. f American Phil. Trans., New Series, vol. v. p. 319 et seq. 1835, and vol. vi. p. 347 et seq. 1839. } States' Report, 1840. Tertiary Formations of the United States. 305 almost eqnally near to the Ostrea bellovacina and the 0. sellaformis, so widely disseminated throngh the eocene formations of South Carolina and Georgia, is found in the uppermost beds of the formation at Coggin's Point, on the James River. The part of Virginia to which these remarks refer, is a flat region, forty or fifty feet above the level of the sea. The miocene strata which compose the upper beds con- sist sometimes almost exclusively of shells, and in the neighbourhood of Williamsburg Mr. Lyell collected eighty species, which bear a great resemblance generically, and in their relative numerical force, to collections from the Suffolk crag and the Faluns of Touraine. Among these Testacea are several species of Astarte, some very analo- gous to those of Suffolk, the Voluta mutabilis, which resembles the V. Lamberti, also Conus diluvianus, Lucina squamosa, and L. divari- cata. Mr. Lyell says there are many other analogies among the Mollusca, besides the occurrence of several corals, Echinodermata, fishes' teeth and bones of Cetacea ; but he shows that the most im- portant point of comparison is in the proportion of recent to extinct Testacea. Out of eighty-two species which he collected at Williams- burg, sixteen are considered by Mr. Conrad to be recent, and found for the greater part living on the coasts of the United States. The existing species, therefore, are in the proportion of one-fifth of the whole, which agrees well, says the author, with the average per-centage in the shells obtained by him in 1 840 from the Faluns of Touraine. The entire number of American miocene shells known to Mr. Conrad is 238, of which thirty-eight have been identified with recent species. North Carolina. — In the neighbourhood of South Washington, on the north-east branch of Cape Fear river, Mr. Lyell found the dark, bluish marls of the cretaceous series, to which his attention had been directed by Mr. Hodge's paper in Silliman's Journal*. They closely resemble, in composition and organic contents, those in New Jersey, and abound with Belemnites mucronatus, Exogyra costata, and a spe- cies of Gryphsea resembling G. columba ; Mr. Lyell also found in them Ostrea vesiculous and O. pusilla of Nillson, likewise Anomia tellinoides, a species of Plagiostoma, and several new shells. These marls extend to the south of Lewis Creek, for several miles along the banks of the north-east branch of Cape Fear river, nearly to Rocky Point, where they are covered by the Wilmington limestone and conglomerate. This formation, which is overlaid by miocene strata, and ranges to Wilmington, as well as along the coast to Cape Fear river, has been considered by Mr. Hodge, and other geolo- gists, to be an upper secondary deposit, or interposed between the eocene and cretaceous series; but Mr. Lyell could find in it no or- ganic forms which supported this opinion, nor could he learn that any had been discovered. On the contrary, the only determinable species apparently agree with the Lucina pendata, an Alabama shell, and Peclen membranosus, both eocene fossils. The organic remains at Wilmington are only casts, but are referable to the genera Cardium, Nucula, Corbula, Cardita, Venus, Area, Natica, Oliva, Cypraea, Conus, Calyptraea, and Siliquaria. Associated with these remains * Vol. xli. p. 332, 1841. Phil. Mag. S. 3. Vol. 23. No. 152. Oct. 1843. X 306 Geological Society : — Mr. Lyell on the of Testacea are a species of Lunulites and several other corals, the claws of Crustacea, and teeth of the Lamna family. Many of these fossils occur at Rocky Point, including Pecten metnbranosus, with a Lunulite and a Vermetus subsequently found by the author in the limestone of the Santee canal in South Carolina. South Carolina and Georgia. — Charleston stands on a yellow sand, beneath which is a blue clay containing the remains of Testacea that inhabit the adjacent seas j and Dr. Ravenel informed Mr. Lyell that he had found in it the Gnathodon cyrenoides, not now known to occur in a living state nearer than the Gulf of Mexico. The author could not ascertain whether this post-pliocene formation rises above high-water mark ; but he states that, on the Cooper river thirty miles north of Charleston, there occurs beneath the superficial sand and mottled clay a freshwater formation, in which Dr. Ravenel has found the remains of the Cypress, Hiccory and Cedar, which must have grown in a freshwater swamp, although the formation is now six feet below the level of high water. No shells have been noticed in the deposit, but they are also commonly wanting in the marsh accu- mulations of that region. As the salt water of Cooper river must now cover much of this deposit, a very modern subsidence, Mr. Lyell says, must have taken place along the coast. At Dr. Ravenel's plantation in the low country near the mouth of Cooper river is a pulverulent limestone, artificially exposed, which Mr. Lyell thinks may be an eocene formation, though its fossils differ from those of other deposits of that epoch. Between this point and Vance's Ferry, on the Santee river, is a continuous formation of white limestone, which Mr. Lyell examined with Dr. Ravenel at Strawberry Ferry, Mulberry Landing, the banks of the Santee canal, Wantout and Eutaw. It varies in hardness, and consists of comminuted shells ; but it very rarely exhibits any laminae of deposition, and even where it attains a thickness of twenty or thirty feet there would be a difficulty in determining whether it were hori- zontal, if a bed of oysters, like that at Vance's Ferry, did not occa- sionally occur. At the Rock bridge near Eutaw springs, the lime- stone composed of comminuted shells, corals, the spines of Echini, &c, resembles so precisely the upper cretaceous formations at Timber Creek in New Jersey, that Mr. Lyell at first felt no doubt of the identity of the two formations, although the organic contents of the limestone prove that it belongs to the tertiary series. This resem- blance has led to the admission into Dr. Morton's excellent work on the fossils of the cretaceous group, of the Balanus peregiinus, Pecten calvatus, P. membranosus, Terebratula lachryma, Conus gyratus, Scutella Lyelli, and Echinus infulatus* , though they do not really belong to the chalk series ; and to several other similar mistakes, whereby, Mr. Lyell observes, beds of passage have been erroneously supposed to exist. Among the most widely distributed of the lime- stone fossils is the Ostrea sellaformis ; and he searched in vain at various points throughout a distance of forty miles for an admixture of characteristic cretaceous and tertiary organic remains, though the * See pi. 10. of Morton's Synopsis. Tertiary Formations of the United States. 307 chalk formation, containing Belemnites and Exogyrae, occurs between Vance's Ferry and Camden. The Santee limestone, he is of opinion, cannot be less than 120 feet thick at Strawberry Ferry, being verti- cally exposed to the extent of seventy feet in the banks and bottom of Cooper river, and to the height of fifty feet in the neighbouring hills. Its upper surface is very irregular, and is usually covered with sand in which no shells have been found. Mr. Lyell followed the limestone north-westwardly for twelve miles by Cave Hall and Struble's Mill to near Half-way Swamp. At Stoudenmire or Stout Creek, a tributary of the Santee, it has disappeared beneath a newer tertiary deposit of considerable thickness, consisting of slaty clays, quartzose sand, loam of a brick-red colour, and beds of siliceous burr- stone. Mr. Lyell is not aware of any published description of this formation, though he afterwards met with it on the Savannah river. In both localities some of the clays break with a conchoidal flinty fracture when dry, and even occasionally pass into a stone closely re- sembling menilite. The fossils which he found were in the state of casts. He does not determine whether this formation should be re- garded as an upper division of the eocene group or not ; but he has little doubt that it is of the same age as the burr-stone series of Georgia. In the notice of the cretaceous and tertiary strata of the Southern states, drawn up by Dr. Morton from the notes of Mr. Va- nuxem, the tertiary limestone and the burr-stone sand and clay are included in the same group, and Mr. Vanuxem informed Mr. Lyell that he had not been able to determine their relative position ; but from what Mr. Lyell saw on the Savannah river, he infers that the burr-stone formation is above the limestone. One of the strata at Stoudenmire is extremely light and of white colour and resembles calcareous tufa, but according to the analysis of Prof. Shepard it con- tains no carbonate of lime ; Mr. Lyell, therefore, states it may pro- bably be of infusorial origin. At Aikin, sixty miles west of Orangeburg, and near the left bank of the Savannah, an inclined plane in a railway has been cut through strata 160 feet in thickness, consisting of earth and sand of a vermi- lion colour and containing much oxide of iron ; also of mottled clays and white quartzose sand with masses of pure white kaolin. These strata are within ten miles of the junction of the tertiary formation and the great hypogene region of the Appalachian or Alleghany chain, and their materials, Mr. Lyell states, have evidently been de- rived from the decomposition of clay-slate and granitic rocks. No fossils were observed by him in the deposit at Aikin. A similar for- mation is extensively developed at Augusta, where the Savannah di- vides the states of South Carolina and Georgia, and it must, in some places, be more than 200 feet thick. Three miles above the town are the rapids, which descend over highly inclined clay-slate and chlorite schist, overlaid unconformably by tertiary beds. This point is the west- ern boundary of the supracretaceous series ; and Mr. Lyell observes, that on all the great rivers of the Atlantic border from Maryland to Georgia, and still further south, the first falls or rapids are along aline at which the granitic and hypogene rocks meet the tertiary, and which X2 308 Geological Society. — Mr. Lyell on the is nearly parallel to the Atlantic coast, but at the distance of 1 00 or 1 50 geographical miles. This great feature, Mr. Lyell states, was first pointed out by Maclure, but he adds that portions of the tertiary formations usually cover the hypogene rocks for a certain distance above the Falls, and that their outline is very irregular and sinuous. On Race's Creek near Augusta, the highly inclined clay slate, con- taining chloritic quartzose beds with subordinate strata much charged with iron, are decomposed to the depth of many yards into clays and sands which resemble so precisely a large portion of the horizontal tertiary strata of the neighbouring country, that the disintegrated ma- terials might be mistaken for them, if the veins of quartz which often traverse the argillaceous beds at a considerable angle, did not con- tinue unaltered. The only point at which Mr. Lyell saw any organic remains in beds associated with these upper tertiary red strata was at Richmond in Virginia, where he obtained casts of decidedly mio- cene fossils j but as he observed on the Savannah river thick beds of sandy-red earth beneath the burr-stone of Stony Bluff, he concludes that the same mineral character may sometimes belong to the upper division of the eocene group. At the rocks six miles west of Augusta, the tertiary beds derived from the hypogene rocks have the appear- ance of granite, and have been called gneiss by some geologists. They exhibit occasionally a distinct cross-stratification, and include angular masses of pure kaolin. Though the Savannah, in its course from Augusta to the sea, flows for the greater part in a wide alluvial plain, and has a fall of less than one foot in a mile, yet Mr. Lyell descended it to obtain infor- mation, by means of the Bluffs, respecting the superposition of the several masses, natural sections being otherwise difficult to obtain. After passing cliffs of horizontal strata in which the brick-red sand and loam prevail, the first exposure of a new deposit was observed at Shell Bluff, forty miles below Augusta. The height of the section was 120 feet, and its extent more than half a mile. The lowest ex- posed strata consisted of white, highly calcareous sand, derived chiefly from comminuted shells, but the beds passed upwards into a solid limestone, sometimes concretionary, and containing numerous casts of shells. In one place a layer of pale green clay showed the hori- zontal character of the formation. The upper part of this deposit is more sandy and clayey, and incloses a bed of huge oysters, Ostrea Georgiana, occupying evidently the position in which they lived. The total thickness of these lower strata is eighty feet. The upper portion of the cliff is composed of forty feet of the red loam which prevails at Aikin and Augusta, and yellow sand. Mr. Lyell did not find any fossils in this deposit, but he believes that it belongs to the burr-stone formation, and therefore to be an upper eocene accu- mulation. At his first inspection of the casts contained in the lime- stone, he inferred that they belonged to eocene species, without any intermixture of cretaceous or miocene forms ; but it was not till he had the advantage of Mr. Conrad's assistance that he was able to de- termine the following twelve species which are well known to be cha- racteristic fossils of the eocene beds of Claiborne and Alabama : — Tertiary Formations of the United States, 309 Oliva Alabamiensis. Corbula nasuta. Calyptreea trochiformis. Dentalium alternans. Venericardia planicosta. Cytherea Poulsoni. perovata Nucula magnifica. Crassatella praetexta. Ostrea sellaeformis. Alabamiensis. The same shelly, white, calcareous beds, overlaid by red clay and loam, are exhibited at London Bluff, nine miles below Shell Bluff, and a ho- rizontal bed of the large oysters is exposed in a cliff two miles farther down the river. At Stony Bluff, on the borders of Scriven county, the calcareous deposit is no longer visible, the cliff being composed of siliceous beds of the burr-stone and millstone series, resting upon brick-red and vermilion-coloured loam. This section, Mr. Lyell states, is of great importance, as it concurs in proving that the millstone of this region, with its eocene fossils, is an integral part of the great red loam and sand formation usually devoid of organic remains. The burr-rock of Stony Bluff abounds with cavities and geodes partially filled with crystals of quartz and agates. In the fragments scattered over the adjacent fields Mr. Lyell observed casts of univalves. At Millhaven, eight miles from Stony Bluff and five from the Savannah river, these siliceous beds again crop out and afford casts of the genera Pecten, Eulima or Bonellia, and a Cidaris. It had been pierced through to the depth of twenty-six feet, and was associated with red loam, white sand and kaolin, affording further evidence of these de- posits belonging to one formation. One mile west of Jacksonborough, in the ford of Briar and Beaver Dam Creeks, is a limestone passing upwards into white marl which appears to have been deeply denudated, and is overlaid by sand that belongs to a formation of sand, loam, and ferruginous sand-rock, re- ferred by Mr. Lyell to the red loam and burr-stone series. The limestone and marl, although rarely exposed in sections, are consi- dered to constitute very generally the fundamental strata of the re- gion on account of the not unfrequent occurrence of lime-sinks or circular depressions, formed in the beds of loam and sand by subter- ranean drainage. The fossils procured from the limestone of Jack- sonborough by Mr. Lyell, as well as those presented to him by Col. Jones of Millhaven, were for the greater part well-defined casts, and were specifically new to American palaeontologists ; nevertheless he has no hesitation, from their general aspect, to regard them as belong- ing to the eocene period. The genera enumerated in the paper are, Conus, Oliva, Bulla, Voluta, Buccinum, Fusus, Cerithium ?, Trochus, Calyptrsea, Dentalium, Crassatella, Chama, Cardium, Cy- therea, Lithodomus, Lucina, Pecten, and Ostrea. The Trochus is considered identical with the T. agglutinans which occurs in the Paris basin ; and the Lithodomus to be undistinguishable from the L. dac- tylus of the West Indies, one of the few eocene Parisian fossils iden- tified by Deshayes. All the Bluffs examined by Mr. Lyell on the Savannah river below Briar Creek belong to the beds above the limestone, and are refer- able chiefly, if not entirely, to the burr-stone formation. In white clays exposed a few hundred yards below Tiger Leap in Hudson's 310 Geological Society. Reach, the author found impressions of Mactra, Pecten and Cardita, also fragments of fishes' teeth, particularly of the genus Myliobates, likewise several teeth of the genus Lamna, and one belonging to a Notidamus or a nearly allied genus. At Sisters Ferry he observed not only the brick-red loam, with the red and grey clay and sand, but a highly siliceous clay, which though soft when moist, exhibits a conchoidal fracture when dry, and resembles flint j in some spots the clay also passes into a kind of menilite. In conclusion, Mr. Lyell offers the following general observations. The part of South Carolina and Georgia which lies between the moun- tains and the Atlantic, and of which he examined a portion near the Santeeand Savannah rivers, has a foundation of cretaceous rocks con- taining Belemnites, Exogyrae, &c, overlaid first by the eocene lime- stone and marls, and secondly by the burr-stone formation with the associated red loam, mottled clay, and yellow sand. According to Mr. Vanuxem's observations, a tertiary lignite deposit sometimes in- tervenes between the cretaceous and eocene series. The remarkable difference in the fossils of the eocene strata at different points, as the Grove on Cooper river, the Santee canal, Vance's Ferry, Shell Bluff, Jacksonborough, and Wilmington, might lead, Mr. Lyell states, to the suspicion of a considerable succession of minor divisions of the eocene period. That the whole are not precisely of the same age he is willing to believe, but he is inclined to ascribe the difference prin- cipally to two causes : 1st, that the number procured at each place is small and therefore represents only a fractional portion of the en- tire fauna of the period, so that variations in each locality may have arisen from original geographical circumstances ; and2ndly, no great eocene collection has been made from any part of the United States. Some of the burr-stone fossils occur in the limestone, and Mr. Lyell thinks the former may bear to the latter a relation analogous to that which the upper marine sands of the Paris basin bear to the calcaire grossier. With respect to the conclusion stated in the beginning of the pa- per, that he had been unable to find any beds containing an inter- mixture of cretaceous and tertiary fossils, Mr. Lyell says, it would require far more extended investigations to enable a geologist to de- clare whether there exist in the Southern states any beds of passage, but he affirms that the facts at present ascertained will not bear out such a conclusion. The generic affinity of the cretaceous fossils of the United States to those of Europe is stated to be most striking, and Mr. Lyell ob- served in Mr. Conrad's collection from Alabama a large Hippurite, a point of analogy not previously recorded. The proportion of recent shells in the eocene strata of the United States appears to be as minute as in Europe, and the distinctness of the eocene and miocene testacea hitherto observed to be as great. Mr. Lyell says, it is also worthy of remark, that the recent shells found in the American miocene beds are not only in the same proportion to the extinct as those of the Suffolk crag, or the Faluns of Touraine, but that they also agree specifically in most cases with mollusca in- habiting the neighbouring sea ; in the same manner as the recent Royal Astronomical Society. 311 miocene species of Touraine agree for the greater part with species now living on the western coast of France or in the Mediterranean, and as the recent testacea of the crag ave identifiable with species belonging to the British seas. This result appears to Mr. Lyell to confirm the accuracy of conchological determinations ; for if, on the contrary, it should be maintained, that the number of recent species is so enormous, and different species resemble each other so closely as to have produced identifications from the mere difficulty of effecting discriminations, he would suggest that in that case, according to a fair calculation of chances, nine-tenths of the American miocene species hitherto identified ought to have been assimilated to exotic shells, instead of having been found to agree with some portions of the limited fauna at present known on the American shores. The same argument, he adds, is clearly applicable to the identifications which have been made of fossil and recent shells in the European tertiary formations. May 18, 1842. A memoir "On the Geological Structure of the Ural Mountains," by Roderick ImpeyMurchison, Esq., F.R.S., Pres. G.S., Mons. E. deVerneuil, and Count A. von Keyserling, was read; an abstract of which has been given in the present volume, p. 124. ROYAL ASTRONOMICAL SOCIETY. [Continued from p. 154.] June 9, 1843. (Communications respecting the Comet concluded.) An article by M. Capocci, on the comet, of which the following is an abstract, is extracted from the Giornale della due Sicilie, of 1st May, 1843, and communicated by Colonel Jackson. The article gives an account of a paper read by M. Capocci before the Royal Academy of Sciences of Naples. M. Capocci first corrects a mistake into which some observers appear to have fallen, in over- estimating the length of the tail, to which some persons attributed an extent of 80° to 90°, but which certainly was not visible beyond 40° to 45° from the nucleus. With respect to the difficulty attending the orbit of the comet, he attributes it to the very small perihelion distance, and the consequently very rapid angular motion at the passage through the perihelion ; the comet, during the eighteen days following its perihelion passage (that is, prior to the time of its first observation on March 17), having gone through at least 170° of its angular motion round the sun ; while, during the whole of the time of its visibility afterwards, it described only 3°, from which the orbit was to be determined ; whence it has happened that astrono- mers of very high reputation have published results altogether false. With respect to the particular difficulty attending the circumstance of some of the sets of observations having given a perihelion distance smaller than the sun's semi-diameter, and the apparent consequence that the comet must thus either have passed within the luminous matter of the sun, or have been projected obliquely from his surface, M. Capocci considers that it is more seeming than real, as an error sufficient to accourft for such a paradox would have excited no sur- prise in an orbit with a greater perihelion distance. 312 Royal Astronomical Society, In the meanwhile, the parabolic orbit, which seems to represent est all the observations, is the following : — Perihelion Passage, Feb. 27*5643. Perihelion Distance 0-00538 Long, of the Perihelion 277° 52' 35" Long, of the Node 354 48 50 Inclination 35 56 55 Motion retrograde. M. Capocci thinks it probable, however, that the comet really moves in an elliptic orbit, and that it has appeared several times previously. He thinks it exceedingly probable that the comets of 1618, 1668 and 1702, were identical with the one in question, and that that of 1689 was still more clearly so, a probability which has not suggested itself to any one on account of the orbit of that comet inserted in the catalogue, calculated by Pingre, not being correct. But M. Capocci has found that, supposing the day of the perihelion passage in the year 1689 to have been December 3, the old observa- tions of that comet are sufficiently well represented by the elements of the present one. The physical characters of the comet coincide also perfectly with those of the present one. Now this new and undeniable recognition, observes M. Capocci, curiously modifies the supposed period ; and to make it satisfy all the returns of which we have an account, it is perhaps necessary to reduce it to one of seven years nearly. He does not deny the difficulty of explaining how it has happened that the comet has not been seen at its nineteen former returns ; but he contends that it is less difficult to do this than to account for the strange coincidence in the positions and in the physical appearances of the four comets above mentioned. The following is the whole series of the apparitions which may possibly belong to this one and the same body : — 1618, 1652, 1668, 1689, 1702, 1723, 1758, 1843. Without laying very great stress on this coincidence, he thinks it proper to draw the attention of other astronomers to it, to the end that each, deducing a corresponding ellipse from his own observations, may either confirm or destroy the hypothesis ; a circumstance so much the more important, as each may cherish the reasonable hope of seeing with his own eyes, within the space of seven years, the prediction verified. The following is an abstract of a notice of the comet from a Ma- dras paper received by the Astronomer Royal : — " The comet was first seen on the 2nd of March, but the only part seen above the horizon was part of the tail, and that faintly. " On the 3rd and 4th the nucleus was distinctly visible to the naked eye : the tail was divided into two distinct branches, the one long, but faint, the other much shorter, but broader and much brighter. " On the 5th the tails had apparently united ; but on a careful examination a less luminous band was detected between them. " On the 6th several stars were visible through the tail, which near the star r Ceti was about 40' in breadth. At this part it ap- peared through the telescope to consist of three luminous bands ; the one next to the sun being broad and bright, the other two fainter Royal Astronomical Society. 313 and more narrow towards the nucleus. These bands were less distinct, and not more than a single separation could be detected. The nucleus appeared like a star of the fourth or fifth magnitude : its light was pale, and it was surrounded by a luminous halo of no great extent." Observations of the Comet made at the Observatory of Trevan- drum, accompanied by a Drawing. By J. Caldecott, Esq., Director of the Observatory. The observations were made with an achromatic telescope of 1\ feet focal length and 5 inches aperture, made by Dollond for the Observatory. It is mounted equatoreally on exactly the same plan as Mr. Bishop's instrument, the ends of the polar axis (which is of brass) being supported on pillars of granite. The micrometer made use of is a reticulated diaphragm of gold wire. The instrument keeps its adjustments very permanently, and the place of a known star (after correction for collimation and index error) seldom differs more than a second of time in right ascension, and 15" to 20' in declination. The right ascensions and declinations of the comet are those read from the circles, after being corrected for instrumental errors, and for the effects of refraction, the instrumental corrections having been obtained almost every evening by observations of 6 Ceti, when at nearly the same hour- angle as the comet was observed afterwards. In addition, differential observations of small stars passing through the field within a few minutes before or after the comet have been obtained, and the results will be communicated after the places of the stars have been determined by meridional observations. The following is Mr. Caldecott's account of the observations : — Places of the Comet. Trevandrum Observatory, Lat. 8° 30' 32" N. ; Long. 5h 7m 59s East. Date. Trevandrum | Observed Observed Hemarks . Mean Time. Right Ascension. North P. D. 1843. h m s h m s O / ,, The N. P. D. is probably March 6. 7 4 35-30 0 33 56-4 101 58 0 erroneous this evening 7. Observations prevented by clouds. on account of interrup- tion from visitors. 8. 6 54 30-81 1 0 450 102 7 22 The corrections ob- 9. 6 48 27-13 1 13 48-7 102 0 44 tained from /3Ceti. 10. 6 50 47-96 1 26 22- 1 101 51 37 Ditto from ff Ceti. 11. 6 43 5335 1 38 19-4 101 41 47 Ditto ditto. 12. Observations prevented by clouds &rain. 13. 7 5 57-15 2 0 31-2 101 15 20 Ditto ditto. 14. 6 53 36-38 2 10 37-8 101 0 6 Ditto ditto. 15. 7 13 2-85 2 20 21-3 100 43 22 Ditto ditto. 16. 6 45 57-44 2 29 20-6 100 27 4 Ditto ditto. 17. 6 45 19-51 2 37 570 100 9 48 Ditto di tto. 18. 6 59 3001 2 46 11-7 99 52 2 Ditto ditto. 19. 7 11 56-56 2 53 59-7 99 34 43 Ditto ditto. 20. Not observed on account of clouds. Notes. — The comet was first seen (partially only) on the 4th of March, about half-past six p.m. ; but clouds over the head of it, which was besides very near the horizon, prevented any observations. 314 Intelligence and Miscellaneous Articles. On the 5th a larger portion of the tail was visible, and it was evidently higher than the evening before ; clouds, however, again hung over the head until it set. On the 6th the sky was free from clouds, and the comet presented a most magnificent appearance. Observations of it in Right Ascension and North Polar Distance were obtained this evening with the equatoreal ; but from the excitement at first view of so splendid an object, together with the confusion caused by a number of visitors at the Observatory, I do not consider them entitled to much confidence, especially those in North Polar Distance. The length of the tail I measured roughly with a sextant, by bringing down the image of a star which happened to be situated near the faint end of it, into contact with the head, and made it to be about ,36° ; but from a much better measurement made in the same way on the 13th, this was probably too small. The nucleus of the head (seen through the 75-feet telescope) presented rather a well-defined planet-like disc, the diameter of which I estimated to be about 12", and that of the nebulosity surrounding it at about 45". The tail had a dark appearance along its axis as if hollow,- and at about half-way from the head, it even appeared to separate slightly into two parts, the upper one being rather longer than the other. On the 13th, after the observations for position, I introduced a parallel wire micrometer, with a view to measure the diameter of the bright part, or disc, of the head, and, by a pretty fair measure, made it to be 11". The nebulosity about it I estimated to be about four times the diameter of the bright part. The length of the tail, measured carefully with a sextant, I found to be 45°; its breadth, at one-third its length from the head, 33', and at two-thirds its length, 60'. Since the 19th the weather has been unfavourable, and no observations have been obtainable. The comet appears to be getting somewhat fainter than it was on the evenings of the 6th and 8th, but only slightly, and very slowly so. Trevandrum Observatory, March 22, 1843. John Caldecott. A second letter has been received from Mr. Caldecott, dated April 21, giving the following additional observation : — h m s h m s March 26. 7 3 3635 Trev. M.T. R. A. = 3 38 7"3. N.P.D. = 97° 39' 12". From the observations of the 8th, 13th, and 18th of March, Mr. Caldecott computed the parabolic elements, which are as follow : — Long, of the Ascending Node 3° 7' Inclination 35 3 Long, of the Perihelion 279 6 Perihelion Distance 0-0048 Time of Perihelion Passage, Feb. 27'654, Trevandrum mean time. Motion retrograde. XXXVII. Intelligence and Miscellaneous Articles. ON THE NON-PRECIPITATION OF LEAD FROM SOLUTION IN SULPHURIC ACID BY HYDROSULPHURIC ACID. BY. M. DUPAS- QUIER. WHEN a current of hydrosulphuric acid is passed through, or an aqueous solution of this acid gas is poured into, commercial sulphuric acid diluted with an equal weight of water, only tin and Intelligence and Miscellaneous Articles. 315 arsenic, if they be present, are precipitated ; and the precipitate con- tains no sulphuret of lead. As to the iron which the sulphuric acid contains, it is well known to be the protosulphate, upon which hy- drosulphuric acid has no action. The non-formation of sulphuret of lead in this case had led the author to think, contrary to the general opinion, that commercial sulphuric acid does not contain sulphate of lead, and consequently that this metal is completely insoluble in it ; but on trial he adopted a contrary opinion. The following experiments were performed : — 1 . Recently precipitated sulphate of lead was put into a glass and covered with concentrated sulphuric acid, and exposed to the air during about six months, taking care to shake the mixture occa- sionally. The acid was considerably diluted by absorbing atmo- spheric moisture. This acid, rendered clear by standing, was sub- mitted to the action of a current of hydrosulphuric acid gas without occasioning any discoloration or precipitation of sulphuret of lead. 2. Sulphuric acid of sp. gr. about l-540, was boiled for an hour on sulphate of lead, and afterwards the experiment was repeated with concentrated acid. The liquids rendered clear by standing were treated with a current of hydrosulphuric acid gas, but neither precipitation of sulphuret of lead nor discoloration were produced. These experiments seem to prove that even boiling concentrated sulphuric acid does not dissolve sulphate of lead, and consequently that the acid of commerce cannot contain any ; but on adding water to the acids which had been boiled with the sulphate of lead, after they had become clear, a considerable white precipitate was formed ; this could only be attributed to the separation of the acid from the sulphate of lead which it had dissolved, an effect which is precisely similar to the precipitation of sulphate of barytes dissolved by con- centrated sulphuric acid. An aqueous solution of hydrosulphuric acid was then added to the acid which had been treated with water, and still holding in suspen- sion the white precipitate which had been formed ; but neither the liquid nor the precipitate was rendered brown by the hydrosulphuric acid : they remained perfectly colourless. From these facts M. Du- pasquier began to suspect that sulphuric acid prevented the forma- tion of sulphuret of lead ; that this is actually the case was proved by the following experiment : — Sulphate of lead was put into a glass and covered to about 1£ inch of concentrated sulphuric acid, agitation being used to effect their mixture. Being afterwards subjected to the action of hydro- sulphuric acid, both in its gaseous state and in solution, the mixture remained perfectly white. The same result was obtained by causing hydrosulphuric acid to react upon sulphuric acid, which had been boiled with sulphate of lead, and then mixed with this salt ; in neither case was there the slightest formation of sulphuret of lead. In order to prove that the discoloration both of the dissolved and undissolved sulphate of lead was owing to the presence of an excess of sulphuric acid, the following experiments were performed : — 1 . The precipitated sulphate of lead was washed with distilled 316 Intelligence and Miscellaneous Articles. water, and treated with hydrosulphuric acid, when it became imme- diately black. 2. Sulphuric acid which had been boiled with sulphate of lead was saturated with potash ; in this state a current of hydrosulphuric acid immediately^rendered it black, and on standing a deposit of sulphuret of lead was formed. It follows from what has been stated, — 1st. That a small portion of sulphate of lead is soluble in concen- trated sulphuric acid. 2nd. That hydrosulphuric acid does not react upon sulphate of lead dissolved in a great excess of sulphuric acid, or mechanically mixed with it. 3rd. That consequently, hydrosulphuric acid cannot be employed for the purpose of ascertaining the presence of sulphate of lead in commercial sulphuric acid. 4th. That boiling concentrated sulphuric acid dissolves some sul- phate of lead, the greater part of which is precipitated on the addition of water. 5th. That hydrosulphuric acid immediately reacts, and sulphuret of lead is instantly formed from the sulphate whether it is dissolved or not, when the excess of sulphuric acid is saturated by an alkaline base ; from which it evidently results, that it is the excess of sul- phuric acid that prevents the reaction of the hydrosulphuric acid on the oxide of the sulphate of lead. — Journal de Pharmacie et de Chimie, Aout, 1843. HALO ROUND THE SUN, SEEN BY MR. VEALL, BOSTON. S.W. At Boston, June 16th, 1843, at 2h 30m p.m., was seen a halo round the sun, with prismatic colours on the north-east and south- Intelligence and Miscellaneous Articles. 317 ■west, and a much larger circle, well-defined, of a pale white, having the sun in the south-west of its circumference. The interior of the halo, except the sun's disc, was of a much darker colour than the surrounding atmosphere. The centre of the larger halo was very near, if not in the zenith. CRYSTALLIZATION OF OCTAHEDRAL IODIDE OF POTASSIUM. BY M. BOUCHARDAT. By evaporating a saline solution containing iodine, iodide of po- tassium and acetic aether, M. Bouchardat obtained light yellow- coloured semitransparent octahedral crystals. These crystals, when heated in a tube, yielded traces of iodine, and the fused residue con- sisted entirely of iodide of potassium ; similar crystals were pro- duced from a solution of biniodide of potassium by spontaneous eva- poration ; in order to obtain them there must be a great excess of iodine in the solution, although they do not contain l-1000dth of their weight of free iodine ; but it is certainly curious to observe the iodide of potassium lose its usual form owing to the presence of so small and indefinite a portion of iodine. — Journal do Pharm. et de Chim., Juillet 1843. ON THE PRESENCE OF THE SULPHATE OF TIN IN THE SUL- PHURIC ACID OF COMMERCE. BY M. DUPASQUIER. It is generally known that the sulphuric acids of commerce con- tain lead, iron, and frequently arsenic ; but I am not aware that the existence of tin in them has hitherto been noticed. Nevertheless this metal may be obtained, and in somewhat considerable quantity, from most of the commercial acids ; and it will not be useless to be aware of this circumstance, which may have some influence in many operations, especially in those of dyeing, which should be taken into consideration. I found sulphate of tin in all the acids which I examined while engaged in the researches which I have published on the arsenife- rous sulphuric acids in the following manner : — In order to precipi- tate the arsenic of these acids, I diluted them with twice or six times their weight of water, and passed a current of sulphuretted hydrogen through them, which gave rise to a yellowish-brown pre- cipitate when the acid contained arsenic ; this precipitate was less considerable, and of a darker brown when the acid was not arseniferous. Thinking that sulphuret of lead might have been formed, and that the brown colouring of the sulphuret of arsenic should be attributed to that compound, I treated the precipitates obtained by the action of sulphuretted hydrogen on the sulphuric acids with nitric acid, and I constantly obtained a white residue, insoluble in water, soluble in aqua regia, which solution presented all the characters of the nitro-muriate of tin. With respect to the solution effected by the nitric acid, I found it to be arsenic acid when this sulphuret of tin 318 Intelligence and Miscellaneous Articles. was mixed with the sulphuret of arsenic. I could never detect a trace of lead, which circumstance will be accounted for in a subse- quent notice. Having always found sulphate of tin in the sulphuric acids sub- mitted to examination, I questioned myself as to its origin, and I soon ascertained that it was simply due to the action which the acid has on the solder of the leaden chambers. Now it is well known that the soldered portions are very rapidly corroded by the acid vapour with which they are in constant contact. The presence of tin in the sulphuric acid of commerce accounts for the traces of this metal which have sometimes been found in the green vitriol of commerce. — Jourti. de Pharm. for August. ON THE OXIDIZING ACTION OF CHLORATE OF POTASH ON NEUTRAL SUBSTANCES. M. Barreswill has communicated to the ' Journal de Pharmacie ' for August a very interesting fact which he had occasion to observe in conjunction with M. Kochlin, while investigating the mode of action of the chlorate of potash as an oxidizing agent. When a hot solution of this salt is mixed with a solution of the protosulphate of iron, likewise hot, the two perfectly-transparent liquids immediately become turbid, and exhibit in suspension a con- siderable red precipitate. The filtered liquor is also of a red colour. The reaction is one of the most simple and most precise that can be imagined; the chlorate of potash loses the whole of its oxygen, which goes entirely to the protosulphate of iron, causing this to pass into the state of the persulphate, in part neutral salt and in part basic, without any perchlorate being formed : — KO CIO5 + 12FeO, SO3 = KC1 + 3Fe2 O3, (SO3)3 (in solution) + 3Fe2 O3 SO3 (precipitated). The same reaction takes place in the cold, but more slowly. At the boiling temperature it is complicated, from the action of the neutral sulphate of the peroxide of iron on the chlorate of potash, which may be compared to that of sulphuric acid ; for, in fact, the neutral sulphate is converted into the subsulphate, and the two equivalents of acid react on the chlorate of potash. The subsulphate deposited from a hot solution is yellow, anhydrous, and dissolves with diffi- culty in acids, while the subsalt which subsides from a cold solution is red, hydrated, and is very soluble in dilute acids. All the neutral salts of the protoxide of iron behave in a similar manner, which indeed is the case with all neutral -substances susceptible of oxida- tion by exposure to the atmosphere ; the chlorate of potash aban- dons the whole of its oxygen to them. Iron and zinc become oxidized in a solution of the chlorate, and soon the liquid contains chloride only ; the action, which is some- what energetic, is singularly diminished by the layer of oxide which forms and protects the metal. Lead does not oxidize under the same circumstances, but if placed Meteorological Observations. 319 at the same time in contact with water, chlorate and carbonic acid, without the air having access, it is gradually converted into white lead, a fact which very much confirms M. Pelouze's theory of the formation of this compound. A solution of chlorate of potash in water is therefore a powerful oxidizing agent for neutral substances, abandoning both the oxygen of its acid and that of its base. Its action may be compared to that of air or weakly oxygenated water. This property will without doubt find numerous applications. — Journ. de Pharm. for August. NEW BOOKS. A Series of Tables of the Elementary and Compound Bodies, systematically arranged, and adapted as Tables of Equivalents, or as Chemical Labels. By Charles Button and Warren De la Rue. Part I. A Memoir of the Life, "Writings, and Mechanical Inventions of Edmund Cartwright, D.D., F.R.S., Inventor of the Power Loom, &c. &c. METEOROLOGICAL OBSERVATIONS FOR AUGUST 1843. Chiswick. — August 1. Very fine. 2. Cloudy and fine. 3. Cloudy: thunder, storm, with very heavy rain, the latter continuing throughout the night. 4. Rain : showery : clear. 5 — 8. Very fine. 9. Sultry : lightning at night. 10. Hazy: clearandfine. 11 — 14. Exceedingly fine. 15. Sultry: thunder-storm at night. 16. Thunder, lightning and heavy rain : clear and fine at night. 17. Foggy : sultry. 18. Foggy : hot and sultry : clear and fine. 19. Cloudless and very fine. 20. Overcast and fine. 21. Clear : cloudy and fine : clear. 22. Overcast : rain. 23. Fine : overcast : heavy rain at night. 24. Cloudy : clear and fine. 25. Very fine : cloudy : lightning. 26, 27. Very fine. 28. Rain : overcast and windy. 29. Cloudy. 30. Light haze and fine. 31. Hazy : very fine : clear. — Mean temperature of the month 10,1 above the average. Boston. — Aug. 1. Cloudy. 2. Fine. 3. Fine : rain a.m. and p.m. 4. Cloudy : rain a.m. and p.m. 5. Fine. 6. Fine : rain early a.m. 7. Cloudy. 8. Fine: thermometer 77° 2 o'clock p.m. 9. Cloudy : rain, thunder and lightning from 11 a.m. to 11 p.m. 10. Cloudy. 11 — 13. Fine. 14. Fine: rain, thunder and lightning at night. 15. Rain: heavy thunder-storm a.m. 16. Cloudy: heavy rain p.m. 17. Cloudy. 18. Foggy. 19. Fine. 20. Cloudy : rain p.m. with thunder and lightning. 21. Fine. 22. Cloudy : rain p.m. 23. Fine. 24. Rain: rain early a.m. 25 — 28. Fine. 29. Cloudy : rain early a.m. : rain a.m, 30,31. Cloudy. — N.B. This month shows the largest fall of rain in one month since July 1839. Sandwick Manse, Orkney. — Aug. 1. Cloudy: rain. 2. Cloudy: drops. 3. Fog: cloudy. 4. Cloudy. 5. Bright : rain. 6. Bright : cloudy. 7. Cloudy : show- ers. 8,9. Bright: clear. 10. Clear. 11, 12. Cloudy: clear. 13. Clear: cloudy. 14. Bright : cloudy. 15. Clear. 16. Clear: fog. 17. Cloudy: show- ers. 18. Damp: fog. 19. Bright: thunder. 20. Bright: cloudy. 21. Bright: drops. 22. Cloudy : clear. 23, 24. Clear. 25. Bright : showers. 26. Clear : thunder. 27. Thunder. 28. Showers : rain. 29. Showers : cloudy. 30. Drops : cloudy. 31. Cloudy. Applegarth Manse, Dumfries-shire. — Aug. 1. Wet all day. 2. Very wet. 3. Fair and fine. 4. Fine : one shower. 5. Fine. 6. Showers and sunshine. 7. Wet all day. 8. Wet. 9. Very clear and fine. 10. Very fine: one shower. 11. Very fine, but fair. 12, 13. Very fine. 14. Fine, but heavy rain p.m. 15. Fine, but fair. 16. Fine : fair : thunder p.m. 17,18. Fine. 19. Fine: thunder. 20. Heavy showers a.m. 21. Fair a.m. : rain p.m. 22. Heavy rain. 23. Rain: cleared p.m. 24. Very fine. 25, 26. Rain. 27. Shower. 28. Heavy showers. 29 — 31. Fair and fine. 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OOOOOOOOOlOOOOlOlOOlblO^OlOlOOOOO C0CNWCT»'X!Ol©>^C^CO-t,*OtOt>«COOlO--*C-)CO*+iOtOtN.CDOlO^H ^^pH^^^rt^^r-WCNWtNCNCNCNCNCNGSCOCO THE LONDON, EDINBURGH and DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF SCIENCE. [THIRD SERIES.] NOVEMBER 1843. XXXVIII. On the Results of the Panary Fermentation, and on the Nutritive Values of the Bread and Flour of different countries. By Robert D. Thomson, M.D., Conductor of the Laboratory and of the Classes of Practical Chemistry in the University of Glasgow* . SEVERAL years have elapsed since the author first had ^ his attention directed to the comparative chemical and medical values of fermented and unfermented bread as articles of food. The common idea, which yielded the palm of supe- riority to the former, did not appear to be based on solid data, and it was therefore considered desirable that, in reference to a subject of such importance to the nourishment of man, the arguments in favour of such an opinion should be subjected to a careful examination. Judging a priori it did not seem evi- dent that flour should become more wholesome by the de- struction of one of its important elements, or that the vesicu- lar condition of bread could alone be gained by a process of fermentation. When a piece of dough is taken in the hand, being adhe- sive and closely pressed together, it feels heavy, and if swal- lowed in the raw state, it would prove indigestible to the ma- jority of individuals. This would occur from its compact nature and from the absence of that disintegration of its particles, which is the primary step in digestion. But if the same dough were subjected for a sufficient length of time to the elevated temperature of a baker's oven (450°), its relation to the digest- ive powers of the stomach would be changed ; because the water to which it owed its tenacity would be expelled, and the only obstacle to its complete division and consequent subser- * Abstract of papers read before the Philosophical Society of Glasgow, 14th February 1842, and 26th April 1843; and now communicated by the Author. Phil. Mag. S.3. Vol. 23. No. 153. Nov. 1843. Y 322 Dr. R. D. Thomson on the viency to the solvent powers of the animal system would be removed. This view of the case is fully borne out by a refer- ence to the form in which the flour of the various species of Cerealia is employed as an article of food by different nations. By the peasantry of Scotland, barley-bread, oat-cakes, peas- bread, or a mixture of peas- and barley-bread, and also po- tatoe-bread mixed with flour, are all very generally employed in an unfermented form, with an effect the reverse of injurious to health. With such an experience under our daily obser- vation it is almost superfluous to remark, that the Jew does not labour under indigestion when he has substituted, during his passover, unleavened cakes for his usual fermented bread, — that biscuits are even employed when fermented bread is not considered sufficiently digestible for the sick, and that the inhabitants of the northern parts of India and of Affghanistan very generally use unfermented cakes, similar to the scones of Scotland. Such then being sufficient evidence in favour of the whole- someness of unfermented bread, it becomes important to dis- cover in what respect it differs from fermented bread. Bread- making being a chemical process, it is from chemistry alone that we can expect a solution of this question. In the pro- duction of fermented bread, a certain quantity of flour, water and yeast are mixed together and formed into a dough or paste, which is allowed to ferment for a certain time at the ex- pense of the sugar of the flour. The mass is then exposed in an oven to an elevated temperature, which puts a period to the fermentation, expands the carbonic acid resulting from the decomposed sugar and the air contained in the bread, and expels the alcohol formed and all the water capable of being removed by the heat employed. The result gained by this process the author considers to be merely the expansion of the particles of which the loaf is composed, so as to render the mass more readily divisible by the preparatory digestive or- gans. But as this object is gained at a sacrifice of the inte- grity of the flour, it becomes a matter of interest to ascertain the amount of loss sustained in the process. To determine this point the author had comparative experiments made upon a large scale with fermented and unfermented bread. The latter was raised by means of carbonic acid generated by chemical means in the dough ; but to understand the circum- stances some preliminary explanation is necessary. Mr. Henry of Manchester, at the end of the last century, suggested the idea of mixing dough with carbonate of soda and muriatic acid, so as to disengage carbonic acid in imitation of the usual effect of fermentation ; but with this advantage, that results of the Panary Fermentation. the integrity of the flour was preserved, and that the elements of the common salt required as a seasoner of the bread, were thus introduced and the salt formed in the dough. Dr. Hugh Colquhoun first, it is believed, carried this suggestion into practice, in 1826, and made numerous experiments on bread- making*. But it was not till within a very few years that the idea of using bread thus baked on a large scale was carried into execution. From the result of several experiments made at the author's request, it appears that upon an average there is a great loss sustained by flour when it is fermented. In comparison with the bread raised by carbonate of soda and muriatic acid, there is a loss in the sack of flour of 30lbs. 13oz. ; or in round numbers a sack of flour would produce 107 loaves of unfermented bread, and only 100 of fermented bread of the same weight. Hence it appears that, by the com- mon process of fermented baking, in the sack of flour, 7 loaves, or 6^ per cent, of the flour, are driven into the air and lostf. An important question now arises from the consideration of the result of this experiment, viz. does the loss arise entirely from the decomposition of sugar, or is any other element of the flour attacked ? It appears from a mean of 8 analyses of wheat flour from different parts of Europe by Vauquelin, that the quantity of sugar contained in flour amounts to 5*61 per cent. But it is obvious that as the quantity lost by baking exceeded this amount by nearly 1 per cent., the loss cannot be accounted for by the removal merely of the ready-formed sugar of the flour. We must either ascribe this extra loss to a conversion of a portion of the gum of the flour into sugar and its decom- position by means of the ferment, or we must attribute it to the action of the yeast upon another element of the flour; and if we admit that yeast is generated during the panary fermen- tation, then the conclusion would be inevitable that another element of the flour, besides the sugar or gum, has been affected. For Liebig has well illustrated the fact, that when yeast is added to wort, ferment is formed at the expense of the gluten, while the sugar is decomposed into alcohol and carbonic acid. Now in the panary fermentation, which is precisely similar to the fermentation of wort, we might naturally expect that the gluten of the flour would be attacked to reproduce yeast. * Annals of Philosophy, N.S., vol. xii. f In consequence of these and other facts brought forward by the au- thor, the unfermented system of baking has been introduced into many of the unions in England, where he believes it has been found that he has not overrated the saving, which the above experiments would indicate to be upwards of a fifteenth. Y2 324- Dr. R. D. Thomson on the The author has succeeded in forming a wholesome and palatable bread by the employment of ammoniacal alum and carbonate of ammonia or soda as a substitute for yeast. In this process the alum is destroyed by the heat; the bread is vesicular and white, and rises, according to the judgement of the baker, as well as fermented bread. It is obvious that none of the ingredients added can affect the integrity of the consti- tuents of the flour, an occurrence which possibly may happen in the preparation of bread by the common process of fermen- tation, as has been shown, even to the azotized constituents. The disadvantage of such a deterioration is sufficiently evident if we view these principles as the source of nutrition in flour. The first chemist who examined flour with any successful result was Beccaria of Bologna, who detailed his experiments in a communication to the Academy of that place, in 1742. " To endeavour to know oneself," observes he, " is to satisfy the obligation which the oracle of Apollo imposes on every one— to know oneself- — for, if we except the spiritual and im- mortal part of our being, and if we only take into considera- tion our bodies, is it not true that we are composed of the same substances which serve as our nourishment?*" From his subsequent remarks it is obvious that he considered the glutinous part of flour to be peculiarly of an animal and the starch of a vegetable nature; for when distilled, the gluten, he says, affords principles similar to those of all animals, while the starchy part yields products similar to those of all vegetables. We have thus, in the sagacious observations of Beccaria, the origin of the present idea, that animals are principally formed from the glutinous or albuminous principle of vegetables. The mechanical method of analysis which the Italian chemist discovered is the basis of our present process, and it affords undoubtedly the only test which we possess of the compara- tive value of flour as a baking material by the fermented plan. But it fails to inform us of the absolute nutritive value of flour. The most correct method of accomplishing this object is by the determination of the amount of azote present in the flour, by converting that element into ammonia, and precipitating by bichloride of platinum. In the following analyses, to de- termine the comparative values of different kinds of bread and flour, this process has been used, and the nutritive principles calculated by considering them to contain on an average 16 per cent, of azote, according to Dumas. I. Naumburg. Bread with a brown aspect. This town is situated in the south of Prussia, on the river Saale, in the neighbourhood of a fertile country. The specimen was ob- * Collection Academique, vol. x. p. 1, results of the Panary Fermentation. 325 tained by the author at the Preussischen Hof, on the 17th August 1842, and as harvest was only commencing, the flour of which it was baked would be in all probability of the growth of 1841. The same observation applies to all the German specimens : — 10 grs. pulverized and dried at 212° Fahr., being heated with a mixture of lime and soda, yielded, after precipi- tation of the ammonia formed by bichloride of platinum, wash- ing and ignition, 1 *80 grs. platinum = -2639 gr. azote. II. Dresden. White bread from the Stadt Rom, procured 21st August 1842, probably therefore of the growth of 1841 : — 10 grs. afforded 1*57 gr. platinum = -2289 gr. azote. III. Berlin white bread, procured 22nd August 1842, in the Stadt Rom: — 10 grs. gave 1*56 gr. platinum = -2275 gr. azote. IV. Canada flour, probably of the growth of 1842. The same observation applies to the subsequent specimens : — 9*9 grs. gave 1*5 gr. platinum = -221 gr. azote. V. Essex flour: — 9-l grs. gave 1*3 gr. platinum = '2175 gr. azote. VI. Glasgow unfermented bread, raised by means of mu- riatic acid and soda: — 10 grs. afforded 1*47 gr. platinum == -21437 gr. azote. VII. Lothian flour: — 10 grs. gave 1'35 gr. platinum = •1968 gr. azote. VIII. United States' flour: — 10 grs. gave 1*25 gr. plati- num = '182 gr. azote. This experiment appeared to place the United States' flour very low in the scale. The flour was therefore analysed by the mechanical method, and the following result obtained. The quantity used was 3 ounces. per cent. Starch 902-00 . . 68*73 ("Fibrin . . 116-80^1 Giute« fo5i£;d : JSi- 13°-40 • • 9-93 (jLoss (water) 5-29J Albumen 14-00 . . 1*06 Gum 60-40 • * 4-60 Sugar 16-30 . . 1-24 Water . ". 189-40 . . 14-44 3 oz. = 1312-50 grs. 100-00 By the first experiment the platinum obtained indicated the presence of ] 1*37 per cent, of azotized principles, and by the mechanical method the amount was 10-99, a very close ap- proximation. In the latter analysis all the products were dried at 212° until they ceased to lose weight. 326 Dr. Winn on the Production of Heat, Sfc. In the following table the results of the preceding analyses are collected, so as to exhibit the comparative value of each specimen. The first column gives the amount of azotized principles contained in each, and the second column repre- sents their equivalent values in the nutritive scale. 1. Naumburg bread . . . . 16*49 . . 100*00 2. Dresden bread 14*30 . . 115*31 3. Berlin bread 14*21 . . 116*04; 4. Canada flour 13*81 . . 117*23 5. Essex flour 13*59 . . 121*33 6. Glasgow unfermented bread . 13*39 • • 123*15 7. Lothian flour 12*30 . . 1 34*06 8. United States' flour . . . . 11*37 . . 145*03 Ditto, by mechanical analysis 10*99 . . 150*00 This table shows that the German and Canada flour con- tain most nutritive matter ; the Essex flour being only a slight degree lower in the scale. It must be borne in mind, how- ever, that this result may not be in consonance with the opinion of the baker in reference to the capacity of the flour for making good bread, because it takes in another element, the albumen, which is omitted in the baker's estimate. It is therefore quite possible that the specimen holding the lowest position in the table may answer the purpose of the baker in an equal or superior manner to those placed above it ; but the method of determining the comparative value of flour by the estimation of the azote may furnish us at once with data of utility both in commerce and ceconomy*. XXXIX. On the Production of Heat by the Contraction of Elastic Tissue, in reference to a former communication. By J. M. Winn, M.D. To the Editors of the Philosophical Magazine and Journal, Gentlemen, N Dr. Gregory's translation of Liebig's ' Animal Chemis- try,' I find at page 31 the following remark : — " The obser- vation has been made that heat is produced by the contrac- tion of muscles, just as in a piece of caoutchouc, which, when rapidly drawn out, forcibly contracts again with disengage- ment of heat." With the exception of an essay in the Lancet * The result of Sir H. Davy in reference to the quantity of gluten in British flour, is sometimes nearly the double of the numbers in the table. This may perhaps be ascribed to his mode of drying the gluten. 1 Mr. Everitt on Garden Rhubarb as a Source of Malic Acid. 327 for September 2, 1843, in which the writer attempts to appro- priate my views, I do not know of any observations to which the Professor can allude, but those which I published in your Journal for March 1839 [S. 3. vol. xiv. p. 174], and if he will refer to them he will perceive that he has not quite under- stood my notions. My experiments were made with elastic and not muscular tissue, and the increase of heat in the caoutchouc operated on was observed immediately after it had been elongated and before it had been allowed to re- contract. As the Professor's imperfect explanation of my views might bring them into some discredit, I shall feel obliged by your publishing this Note. I have the honour to be, Gentlemen, Your obedient Servant, J. M. Winn. Truro, Sept. 21, 1843. XL. The Leaf-stalks of Garden Rhubarb as a Source of Malic Acid. By Thomas Everitt, Esq.* THE large quantity of this substance which is brought to our vegetable markets for several months in the year, beginning very early in spring, and its powerful though agreeable acid taste, make it a subject worthy of a more minute chemical examination than any which it has as yet been sub- jected to. The leaf-stalks of garden rhubarb were first examined by Mr. Hendersonf, who discovered in them, as he thought, a peculiar acid; afterwards by M. LassaigneJ, who showed that the supposed new acid was oxalic acid. But these expe- rimenters examined only the precipitate obtained by putting chalk into the expressed juice; the first-named decomposing the insoluble precipitate thus obtained by sulphuric acid; the other, by boiling it with excess of carbonate of potassa, then neutralizing the solution with nitric acid, and precipitating by a salt of lead, decomposing the latter by sulphuretted hydrogen, and thus getting crystals which were oxalic acid. Now by both these processes, those chemists threw away, in the liquid which floated above the oxalate of lime, an important con- stituent in a large quantity, viz, malate of lime, with a great many other things of less importance, but which rendered the * Communicated by the Chemical Society; having been read February 7, 1843. f Thomson's Annals of Philosophy, vol. viii. p. 247. (1816.) % Annalet de Chimie et de Physique, torn. viii. p. 402. (1818.) 328 Mr. Everitt on Garden Rhubarb as a Source of Malic Acid. devising of a process for obtaining the principal ingredients pure, a difficult analytical problem. The details of the pre- liminary experiments (which occupied some time) for finding out what I had to deal with, would be both tedious and use- less ; I proceed, therefore, to give a summary of the method I adopted for the analysis of this substance, and of the best means of proceeding, if the extraction of malic acid be the only object. The stalks should have the cuticle taken off, as it would introduce a great deal of colouring matter if put into the press ; the peeled stalks are cut into small pieces about an inch long, put into a strong canvas bag, and then subjected to a great pressure ; by this means 20,000 grains of peeled stalks yielded 12,500 grains of juice, and left 3850 grains of damp fibre, which well washed and dried at 212°, weighed 800 grains, and is equal to 4 per cent, ligneous fibre. The liquid had a light green colour, was very acid, its density varied with the size of the stalks and the time elapsed since they were cut, it also varied in the same specimen at different periods of the pressing ; that which flows first I have had as low as 1-015, rising to that last yielded 1-022. I tried how much pure carbonate of soda and carbonate of potassa were required to saturate a definite quantity ; but as it afterwards was found to contain two or three acids, and some salts of soda and potassa also present, these results are of no use for determining the quantity of free acid. Some pure crystals of carbonate of lime were made into a neutral nitrate ; chloride of calcium being avoided as in a subsequent stage chloride of lead, and hydrochloric acid would be formed, to get rid of which would have complicated the process. To several pints of the juice bicarbonate of potassa was added, this salt being used because it is much purer than the carbonate, until all acidity was neutralized : a small quantity of greenish pulpy matter made its appeai-ance, which was separated by a cloth filter, and the liquid became much less coloured: 4000 grains measure, specific gravity 1-01 2, required 65 grains of crystallized bicarbonate potassa for neutralization: 4000 at 1-023 required 93 of the same for neutralization: nitrate of lime was now added and the solution boiled : this is necessary, because oxalate of Jime, when precipitated cold and thrown on a paper filter without boiling, passes through ; moreovei*, malate of lime requires only 65 parts of boiling water to hold it in solution. I found the separation of the oxalic acid perfect by these means, while all the malates re- mained in solution. The oxalate of lime collected on the filter, amounted to 24*2 grains, dried at 212°, or the proto- hydrate. It was tested in the usual way of boiling with ex- Mr. Everitt on Garden Rhubarb as a Source of Malic Acid. 329 cess of carbonate of soda or potassa, filtered, neutralized with nitric acid, and precipitated by nitrate of silver ; the powder dried and heated exploded feebly in the manner peculiar to the oxalate of silver, leaving metallic silver. Nitrate of lead was now added to the solution which had passed through the filter from the oxalate of lime, and a copious bulky precipitate was formed, which the next day, when it was cold, had formed on its surface a few of the beautiful flat pearly crystals cha- racteristic of malate of lead : it was brought to the boil, and the malate of lead assumed a consistency like dough before it goes into the oven ; and when that cooled it became as brittle as resin. The liquid above the solid mass was decanted and yielded good crystals on cooling. The whole malate of lead was carefully washed and elutriated. About two-thirds of it was acted on afterwards by sulphuric acid gently heated; then separating the sulphate of lead by a filter, the remaining third of malate lead was suspended in the liquid, and sulphu- retted hydrogen passed through it till all the malic acid was set free. This decomposition of some of it by sulphuretted hydrogen, renders the solution sufficiently colourless, while to do the whole in this way is very tedious. When operating on several ounces, after filtration to collect the sulphuret of lead, the free malic acid must be evaporated by a water or steam bath to the thickness of syrup ; and it was only obtained of the consistency of thick honey, by keeping it under the re- ceiver of an air-pump, near the surface of oil of vitriol, for nearly a week, occasionally taking out the capsule to warm it. Some of the original juice, evaporated in the same way, yielded beautiful crystals of binoxalate of potassa. After this the liquor still retained a small trace of citric acid, which I obtained in a distinct form by taking advantage of the difference of the solubility of malate and citrate of ba- ryta. No tartaric could be detected. 4000 grains of the original liquid evaporated and ignited in platinum, yielded 29*2 grains of ashes, of which 28*4 grains were soluble in water, and 0*8 insoluble. The solution of these 28*4 grains was alkaline, and required 12 real nitric, or 8*9 of sulphuric acid to neutralize it (these two acids were used of an exact strength so as to contain 1 grain of real acid in 100 grains water measure). To the neutral solution of the ashes in sulphuric acid nitrate of baryta was added; a precipitate was formed, part of which was so- luble on adding a little nitric acid, and turned out to be phos- phate. The insoluble sulphate weighed 39*73 grains: no lime salt was present. The nitric acid solution of the phosphate evaporated to dryness left 4*4 grains j it was well tested and 330 Mr. Everitt on Garden Bhubarb as a Source of Malic Acid. certainly proved to be phosphate, being made into an alka- line phosphate and tested by silver and other means. To the solution which filtered from the mixed sulphate and phos- phate, containing excess of nitric acid, nitrate silver was added and 4*1 of chloride obtained; to the solution filtered from the chloride of silver, excess of hydrochloric and sulphuric acids were added to remove the excess of silver and baryta : the filtered liquid evaporated to dryness and ignited, after putting on it excess of sulphuric acid, gave 39*3 grains of a white salt, quite soluble in water (sulphates of soda and potassa) ; these were dissolved in a minimum of water, and excess of crystals of tartaric were added; the granular pre- cipitate washed with dilute alcohol, weighed 33*3 ; the solu- tion from the bitartrate of potassa evaporated and ignited, then treated with sulphuric acid, evaporated again to dryness and ignited, gave of dry sulphate of soda 4*7 ; this was dissolved in water, and being slowly evaporated, the characteristic cry- stals were formed. From the above data, and from some subsequent experi- ments on a much larger quantity of juice, an imperial gallon (sp. gravity T022), contains nearly, of Malic acid dry 11 139*2 grains. Oxalic acid dry 320*6 „ Potassa combined with organic-chlo-" ride, soda, sulphuric and phosphoric acids, traces of silicon and a little vegetable extract 229*6 If to obtain malic acid be the only object, slaked lime made into a sort of cream with water might be added to the ex- pressed juice, till the solution became slightly alkaline ; it might then all be boiled and filtered, then proceed with the nitrate of lead and the rest of the steps above described. To procure the malate of lead in good crystals, some precautions are necessary. From the precipitate suspended in water and heated, a few grains only fall on cooling ; from 2 pints I only obtained 5^ grains; but if about 2 per cent, of acetic, or of some free malic, be added to the water, and finely divided malate of lead be added, and the whole warmed by a water bath, with constant stirring, the quantity of crystals will be doubled for the same bulk of liquid. It is proper not to raise the temperature higher than 160° Fahr. ; if boiled the salt loses two or three atoms of its water of crystallization, and then is quite insoluble in water hot or cold. The compo- sition of malic acid is exactly the same as that of citric acid, C4 H2 04. Dr. Stenhouse's Examination of Astringent Substances. 331 The crystals of malate of lead are thus constituted : — 1 proportion of acid ... 58 ... 29*68 I proportion of oxide of lead 112 ... 56*62 3 proportions of water . . 27 ... 13*70 100*00 100 grains of the crystals exposed in a thin stratum on a porcelain dish, can lose at 212° 9*2 water = 2 proportions, but it required to be heated in a thin glass tube, by means of an oil-bath to 356° Fahr. before it lost the other third. When the crystals are boiled in water, they lose also 2 proportions of water, and assume the form of dough after it has been kneaded ; the mass on cooling becomes as brittle as resin. XLI. Examination of Astringent Substances (continued). By John Stenhouse, Esq., Ph.D.* Black and Green f^* REENand black tea are said by Mulder, Tea. ^^ the chemist who has most recently ex- amined the subject, to be both derived from plants of the same species. The differences observable in them are, as he al- leges, chiefly owing to their being collected at different pe- riods of their growth, and to the greater or less degree of heat with which they are subsequently dried ; the black teas being strongly heated upon iron plates, while the green teas are exposed to a comparatively moderate temperature. If this statement is correct, it may serve to explain what has been long observed, that an aqueous infusion of black tea, though quite transparent while hot, becomes muddy on cooling, while an infusion of green tea retains its transparency even when quite cold. The reason of this difference probably is, that most of the essential oil of black tea is converted, by the partial roasting it has undergone, into a resinous matter, which though soluble in hot is nearly insoluble in cold water, while the essential oil of green tea, on the contrary, remains nearly unchanged, which is probably the cause both of the clearness of its solution and perhaps also of the more powerful effect which green tea is well known to exert on the animal ceco- nomy. The aqueous infusion of both green and black tea give dull olive-black precipitates with protosulphate of iron, which on standing become leaden black. Infusions of tea also, when evaporated to dryness and distilled, give crystals of theine * Communicated by the Chemical Society; having been read Feb. 21, 1843. The former part of Dr. Stenhouse's paper appeared in Phil. Mag., S.3. vol.xxii. p. 417. 332 Dr. Stenhouse's Examination which collect on the sides and neck of the retort, while the empyreumatic liquor which passes into the receiver gives pretty distinct indications of containing pyrogallic acid. The Tannin of Tea. — In order to separate the tannin of tea from the other proximate principles of the plant, its aqueous infusion was precipitated with acetate of lead, and the preci- pitate carefully washed with hot water. Green tea gave a bright yellow precipitate, but that of black tea had a brownish- yellow colour. The lead salts were decomposed by sulphu- retted hydrogen : the solution of the tannin of green tea had only a slight yellow colour, while that of black tea had a much darker colour, but in other respects the properties of both appeared to be the same. The following are the effects upon them of different reagents : — with solution of gelatine they gave white bulky precipitates, and they also gave copious white precipitates with tartar-emetic. Protosulphate of iron throws down bright bluish-black precipitates, nitrate and chloride of iron, olive black, and acetate of iron purple black preci- pitates. The solution of the tannin when evaporated to dry- ness on the water-bath, became of a reddish-brown colour, and was partially decomposed. When this tannin was subjected to distillation, it invariably yielded a quantity of pyrogallic acid, which sometimes ap- peared in crystals upon the sides of the retort, but which more frequently remained dissolved in the empyreumatic li- quor which passed into the receiver. In this it was easily de- tected by the usual reagents. It gave a fine reddish-purple colour when dropped on milk of lime, with protosulphate and protonitrate of iron, a fine indigo-blue colour, and with proto- chloride, a blue resembling ammoniuret of copper. As the quantity of pyrogallic acid obtained was always much less than that which the same quantity of the tannin of either galls or shumac would have yielded, I was led to suspect that it did not arise from the decomposition of the tannin in the tea, but resulted from some gallic acid with which the tannin was mixed. Of the accuracy of this opinion I was speedily con- vinced by the following experiment : — On treating a strong solution of the tannin with nearly half its bulk of sulphuric acid added by little and little at a time, a dark brown precipi- tate fell consisting of the tannin combined with the acid. It was however much more soluble than the corresponding com- pound of the tannin of galls. It was collected on a cloth filter, strongly compressed, and washed with a little cold water to free it as much as possible from adhering acid. When sub- jected to distillation it did not afford the slightest trace of pyrogallic acid, showing evidently that the pyrogallic acid of Astringent Substances. 333 I had previously obtained was not derived from the tannin of the tea. When another portion of the precipitated tannin was boiled with tolerably dilute sulphuric acid, it did not yield any gallic acid, but was changed into a dark brown substance, nearly insoluble in cold, and but very little more so in boiling water. It gave a grayish black precipitate with protosulphate of iron, but was not precipitated either by gelatine or tartar- emetic. It dissolved however pretty easily both in alcohol and alkalies, forming dark brown solutions. It is evident therefore that though in some of its properties the tannin of tea agrees pretty closely with that of nut-galls, still the pro- ducts of its decomposition are essentially different. The tea was next examined for the gallic acid which it evi- dently contained, and this I was always able to procure by either of the following methods : — The mixture of tannate and gallate of lead obtained by precipitating a decoction of tea by acetate of lead, was decomposed as before by sulphu- retted hydrogen and evaporated to dryness. It was then ma- cerated with a very little cold water which removed most of the tannin, but dissolved scarcely any of the gallic acid. The residue was again dried, reduced to powder and mixed with some sand, was repeatedly agitated with aether in a stoppered bottle. The aethereal solution was then poured off, and al- most the whole of the aether was recovered by distillation. The residue when left to spontaneous evaporation deposited crystals, which at first had a yellow colour, but which were rendered perfectly white by a second crystallization. The other process was somewhat more tedious, but by it very small quantities indeed of gallic acid can be detected. It consists in putting a number of bits of prepared skin into the mixed solution of tannin and gallic acid already mentioned, and al- lowing them to remain for nearly a fortnight till the whole of the tannin is absorbed by the skin. The gallic acid is then precipitated by acetate of lead, and the precipitate having been well washed, first with hot water and then with spirits of wine, is to be decomposed by sulphuretted hydrogen. When evaporated to dryness and treated with aether as before, crystals of gallic acid are readily obtained, which are at first much purer than those got by the former method. I examined several specimens both of black and green tea, and also one of Assam tea, in every instance with similar re- sults. It is evident, therefore, that tea, besides a species of tannin which gives bluish-black precipitates with protosul- phate of iron, invariably contains a small but constant quan- tity of gallic acid, a constituent which has hitherto been over- looked. 334- Dr. Stenhouse's Examination Myrobalans. — The name Myrobalans is applied to the fruit of several East Indian trees, the species of which are, I believe, not yet all accurately determined. That which I ex- amined was the yellow kind, the fruit of the Jerminalia Che- hula. The ripe fruit has a brownish-yellow colour, is pear- shaped, and deeply wrinkled. It consists of a white pentan- gular nut containing a small white oily kernel, and is covered by a mucilaginous and very astringent husk, nearly two lines in thickness. Each of the fruit weighs from 70 to 100 grains, and of this 50 or 60 grains are husk. It is in the husk that the whole of the astringent matter is contained, and it may be easily separated from the nut by slightly pounding or bruising the fruit. The powder of the husk is dark yellow, and its taste is very sharp and astringent. The colour of its aqueous infusion is deep yellow. With protosulphate of iron it gives a deep bluish-black precipitate, which is rather deficient in lustre. The dullness of the colour is owing to the presence of impurities in the husk, for on purifying the astringent matter by precipitating it with acetate of lead, and then decomposing the lead compound with sulphuretted hydrogen, the solution thus obtained gives as fine a colour as can be procured from infusion of galls. With gelatine it gives a very copious, slightly yellow precipitate, the quantity of astringent matter contained in myrobalans being very consi- derable. With tartar-emetic it also gives a copious brownish- yellow precipitate. With protonitrate and protochloride of iron, it gave bluish-black precipitates, which soon changed to olive-black, and with acetate of iron, a fine purple-black precipitate. When the decoction of myrobalans is evaporated to dryness and distilled, it yields abundance of pyrogallic acid ; this I found, however, to be derived, not from the decomposi- tion of the tannin it contains, but from a quantity of ready- formed gallic acid. Sulphuric acid occasions a very scanty dark brown precipitate in the infusions of myrobalans, if at all dilute, as the combination which this tannin forms with sul- phuric acid is pretty soluble. From concentrated solutions, the tannin is readily precipitated as a yellowish-brown tena- cious mass. Having been collected on a cloth filter, and freed as much as possible from adhering acid, it was dried and distilled. It yielded no pyrogallic acid, and scarcely any empyreumatic oil ; another portion of the same tannin, though boiled in dilute sulphuric acid, was not converted into gallic acid, but changed into a dark insoluble mass. Gallic acid may be readily obtained from myrobalans by precipitating its decoction with a solution of glue, filtering and evaporating to dryness. On treating the residue with of Astringent Substances. 335 aether, pouring off the solution, recovering the greater portion of the aether by distillation, and leaving the remainder to spon- taneous evaporation, crystals of gallic acid were deposited in a few hours. The quantity of gallic acid in myrobalans is pretty considerable. Besides tannin and gallic acid, myrobalans contains a good deal of mucilage, and a brownish -yellow colouring matter, which Dr. Bancroft states was employed in India in his time as a yellow dye. Myrobalans have long been employed by the calico-printers of India instead of galls, and from the large quantity of astringent matter they contain, I think perhaps they might be worth the attention of the tanners and calico- printers of this country. A decoction of myrobalans makes a very tolerable ink, which however, as we have already stated, is rather deficient in lustre. Bistort, Polygonum Bistortus. — The root of this plant, which is pretty common in Scotland, has a pale pink colour internally, but when it is exposed to the air for some time it becomes deep yellow. Its aqueous solution is yellowish at first, but on standing it assumes a fine red colour, and the same effect is immediately produced by boiling it with any of the alkalies. With protosulphate of iron it gives a bluish-black precipitate, a good deal resembling that of galls, but having a bluish-purple shade. Gelatine produces a copious brownish precipitate in a solution of bistort, which shows that the quan- tity of astringent matter it contains is considerable. With tartar-emetic it gives a brownish-white precipitate. When extract of bistort is evaporated to dryness and distilled, it gives distinct indications of pyrogallic acid. The pyrogallic acid however, as in the case of myrobalans, was derived not from the tannin in bistort, but from a quantity of gallic acid with which it was mixed, for on precipitating the tannin by sul- phuric acid, and distilling it alone, not a trace of pyrogallic acid was obtained, and when boiled with sulphuric acid it was not converted into gallic acid. The gallic acid it contains was easily obtained from bistort by precisely the same process as that already described. Its quantity, compared with that of the tannin in the root, was very considerable. Besides tannin and gallic acid, bistort contains a brownish- red colouring matter, and a quantity of mucilage. Bistort may likewise be made to .furnish' a very tolerable ink, which appears to stand very well. It has a bluish-purple shade, owing to the reddish colouring matter of the root. The Cashew 'Nut. — The outer rind of the Cashew nut, the fruit of the Anacardium longifolium, contains a considerable 336 Dr. Stenhouse's Examination quantity of a species of tannin which gives bluish-black preci- pitates with the sulphate, nitrate and chloride of iron, and a bluish-purple precipitate with the acetate. It is also readily precipitated by gelatine, but not by tartar-emetic. This tannin is mixed with a small quantity of gallic acid. The shell of the fruit also contains a good deal of a fatty matter, which is solid at ordinary temperatures and crystallizable. It is easily saponified when boiled with an alkali, its compound with soda crystallizes in large scales. This fat contains an acrid sub- stance which vesicates, but it contains no sulphur. When the fat is first expressed from the nut it is but slightly co- loured, but by exposure to the air it becomes first brown and then black, and loses much of its acrimony. Pomegranate Rind. — The rind of the pomegranate contains a considerable quantity of a species of tannin which precipi- tates gelatine copiously, but gives only a very feeble precipi- tate with tartar-emetic ; with protosulphate, chloride and nitrate of iron, it gives precipitates which are at first deep blue but almost immediately change to very dark olive. With acetate of iron it gives a purple precipitate. Reuss, who has made an analysis of pomegranate rind, states that he found it to contain a little gallic acid. I have been unable to find any, though I have sought it very carefully. LarchBark. — The bark of the larch is employed in Scotland to some extent in tanning. The quantity of tannin it contains is considerable, but the leather made with it is of inferior quality. The aqueous solution of the bark is strongly acid to test paper, and has at first a pale yellow colour, which ex- posure to the air renders brownish-red ; it gives a copious fawn-coloured precipitate with gelatine, but none with tartar- emetic. With the sulphate, chloride and nitrate of iron, it gives olive-green precipitates. Acetate of iron throws it down of a bluish-purple colour. Sulphuric acid precipitates it of a reddish-yellow colour. When boiled with the acid it dis- solves, and the liquid assumes a fine scarlet colour like the infusion of Brazil wood. The altered tannin precipitates on cooling in beautiful red flocks, as it is but little soluble in cold water. It is very soluble in alcohol and alkalies, and its solu- tions have a rich scarlet colour, which is the most character- istic reaction of this species of tannin. Larch bark also con- tains a good deal of mucilage and resinous matter. Birch bark, alder bark, and tormentil root, contain all of them con- siderable quantities of tannin, which closely resemble that of larch bark. All these species of tannin are readily precipi- tated by gelatine, but not by tartar-emetic. They give olive- green precipitates with most of the salts of iron except the of Astringent Substances. 337 acetate, which "throws them down of a bluish-purple colour, which on standing changes to a leaden .gray. When boiled with alkalies they immediately assume a fine red colour, but they differ from the tannin of the larch in not being reddened by sulphuric acid. I think it unnecessary to go into more minute details respecting them, as I have been unable to de- rive from them any determinate or crystalline compounds. I shall leave this subject, therefore, for the present with one or two general observations. The great difficulty of examining the different species of tannin with a view to classifying them, is chiefly owing to their amorphous nature, to the great similarity of their properties, and to the circumstance, that except in the case of nut-galls and shumac, the products of their decomposition are of a very indeterminate character. We think however that there are good grounds for believing that both nut-galls and shumac con- tain the same species of tannin, for the effects of reagents upon it are exactly the same, and the products of its decomposi- tion, when boiled with either sulphuric or muriatic acid, when destructively distilled, or when left to spontaneous decomposi- tion, are in every instance identical, from whichever of these sources it has been derived. It is remarkable also that in so many instances, in eight cases out of ten which I have ex- amined, the species of tannin which give bluish-black preci- pitates with protosulphate of iron are accompanied with larger or smaller quantities of gallic acid. In the present state of our knowledge it is impossible to say whether the gallic acid has originally existed in these substances, or has resulted from the decomposition of the tannin they contain. In the case of galls and shumac the latter opinion is probable enough, as we are easily able to effect this change by artificial means, and it also, as is well known, occurs spontaneously. In the case of the other species of tannin, however, we are still unacquainted with any instance of a similar transformation. It is to be hoped that subsequent researches may yet throw light on this very obscure subject. It is also rather singular that in the case of some of those species of tannin which give green pre- cipitates with salts of iron, a somewhat similar circumstance occurs. Thus the tannin of catechu is accompanied by a crystalline acid body, catechine, which also gives green preci- pitates with salts of iron. I have likewise observed that in the case of infusions of birch bark, alder bark, &c, when the whole of the tannin they contain had been removed by gelatine, the clear liquid when filtered still contained a substance which precipitated salts of iron olive-green, just as the tannin had done, and which threw down salts of lead as copious dark yel- Phil, Mag. S. 3. Vol. 23. No. 153. Nov. 1843. Z 338 Mr. Stubbs on a new Method in Geometty. low precipitates. When the lead salts were decomposed by sulphuretted hydrogen, I obtained an amorphous acid sub- stance of a bright yellow colour, which was soluble in water, alcohol and aether, but which did not appear to be crystal- lizable. XLII. On the application of a new Method to the Geometry of Curves and Curve Surfaces. By J. W. Stubbs, B.A., Trinity College, Dublin. To the Editors of the Philosophical Magazine and Journal. Gentlemen, f HAD the honour of reading a paper before the Philoso- -* phical Society of Dublin, on a new Geometrical principle, which as far as I am aware has hitherto escaped the notice of mathematicians. May I ask of you the favour of inserting it in your valuable Journal? The principle consists in taking the inverse of curves and surfaces, by meansof which we readily find conjugate properties to those possessed by every known curve and surface, the dis- cussion of many of which would be impossible by the ordinary methods. If in the plane of a curve we take any point as a pole and produce the radius vector, so that the rectangle under radius vector to the original curve and the whole pro- duced radius be constant or equal to k% we may call the locus of the extremity of this produced line the inverse curve to the one from which it is produced, and the extremity of the pro- duced radius the inverse point to the extremity of the origi- nal : as an example, the cardioide is the inverse of the para- bola, the focus being the pole ; the lemniscata in the inverse of the equilateral hyperbola. The inverse of a right line is a circle, except when the pole is on the right line, when it is'a right line. The inverse of a circle is a circle wherever the pole is situated, except it be on the circumference, when it be- comes a line perpendicular to the diameter through the pole. To draw a tangent to the inverse curve at the y( . inverse point to a given point on the direct or gene- rating curve, join the points, and on the joining line describe an isosceles triangle, one of whose sides is the tangent to the direct curve. The other will be the tangent to the inverse, as is seen by taking / two consecutive radii; from the property by which / it is generated the quadrilateral A M B C is cir- a1m> cumscribable by a circle; hence the angle A M C / equals the angle T B A, but in the limit the lines ro A M and B C become tangents : this is also clear 'o' 3^7 Mr. Stubbs on a neta Method in Geometry. 339 from this, that r r' — k% then r d r' = — K d r, and r r* rdQ r'dQ „ . ,. — — = j-.. or —j— = 3-r-. Hence the perpendicu- rfr rfr ar flr r r lars from the pole on the tangents are as the radii, and the first perpendicular being known, the second is so also. Having established these principles, I shall proceed to show the application of this method, first to the right line and circle, afterwards to curves of the second degree, and finally to surfaces. If a circle passing through the pole be f^g. 2. called a polar circle ; from the known theo- rem of the bisectors of the angles of a tri- angle meeting in a point, by taking the inverse of all these lines we come to the following theorem : if three polar circles form by their intersection a polar triangle ABC, the polar circles A O, BO, CO bisecting the angles meet in a point O, which is the inverse of the point in which the original bisectors meet. From the theorem of the three perpendiculars from the angles of a triangle on the opposite sides meeting in a point, we get by inversion the three polar circles perpendicular to the opposite sides of the polar triangle, and passing through the angles meet in a point. In like manner every theorem in plane geometry, com- prising only the right line and circle, gives a conjugate one, in which right lines and circles only are contained, — every theorem, I mean, which has relation only to position, without introducing lengths of lines. I shall not mention any more of them, as, when the principle is clearly seen, that to a line corresponds a circle, and to a point a point, to the contact of a line and circle, the contact of two circles or of a line and circle according as the pole is or is not on the circumference of the circle, and to the angle between two lines, the angle between the tangents to two circles at their point of inter- section, any one can multiply theorems at will. The general equation of a conic section being A^ + Btf^+C^ + D^ + Etf + F = 0, substituting for yf r sin 0, and for x, r cos 0, we get Ar2sin20 + Br2 sinflcos 0 + Cr2cos20 + Br sin0 + Er cos 0 + F = 0 A2 1 the pole being at any point, put r — —7-, or —7- for sim- plicity, and Z2 S40 Mr. Stubbs on a netio Method in Geometty. A sin2 fl B sin j cos 9 Ccos29 D sin 9 E cos 9 + F = 0, or multiplying by r4, A ?J2 sin2 9 + B r'2 sin 9 cos 9 + C in cos2 9 + D r'3 sin 9 + E;J3cos9 -f F/J4= 0 is the polar equation of the inverse conic section, its equation in rectangular coordinates being A y* + Bx y + C x* + D^ (.r2 + y2) + E x (.r2 + f) + (x*+f)'2 = 0. 1. If the focus be the pole, the distance from any point P to the focus is to its distance from the directrix in a constant ratio as e to 1. Fig. 3. Fig. 4. Now if we invert the line D O into a circle and the curve into the inverse focal ellipse whose equation is r = k(l — ecos w), we can construct the focal inverse ellipse by a circular direc- trix; (in fig. 4) let S be the pole (which is the focus), S O any circle passing through S ; (in fig. 3) produce S P to T so that S T = -J^ , and S D to R so that RS= ^-^ (which is the o P o J J same as to invert the curve and directrix) from the similar tri- angles R T S, DPS RT: RS::DP:PS::l:e v TRS = DPS = PSV. Hence the circle circumscribing R S T is a tangent to S V at S ; from this may be constructed the inverse focal conic section ; for (in fig. 4) draw any chord S R to meet the circular direc- trix S R O, through S and R describe a circle S R T tangent to S V (the axis) at S, and inflect R T in a given ratio to R S, T is a point in the curve. As the cardioide is only a particu- lar case of the focal conic section, this construction applies to it, making the ratio that of equality. From the focal properties of conic sections we may deduce by inversion the following properties of the curve whose equa- tion is r = k (1— e cos «.). In the parabola the perpendicular from the focus on the tan- gent meets it in the vertical tangent. Hence in the cardioide, if a polar circle be drawn tangent to the curve, the locus of Mr. Stubbs on a new Method in Geometry. 341 the other extremity of the diameter passing through the pole is a circle passing through the cusp or pole and touching the curve at the opposite point, and consequently the locus of its centre is a circle. In a conic section, if a point be taken inside the curve, and any chord be drawn, if we join the points in which it meets the curve with the focus, and also the given point with the focus, the product of the tangents of the half angles formed by those lines at the focus is constant; hence by inversion, if through a fixed point outside an inverse focal conic section we describe a polar circle, and join the points where it meets the curve with the pole, and also the given point with the pole, the product of the tangents of the half angles is constant. In a conic section, if a chord subtend a constant angle at the focus, the envelope of the chord is a conic section with same focus and directrix ; hence by inversion, if the arc of a polar circle contained between the points where it cuts the curve subtends a constant angle at the pole of a focal inverse conic, the envelope of this circle is an inverse focal conic with same pole and circular directrix. If three tangents be drawn to a parabola, so as to form a triangle, the three angles and focus are in a circle ; by inver- sion, if three circles be drawn through the pole of a cardioide touching the cardioide, the points of intersection are in a right line. Every property, in fact, of a curve, with respect to any pole, has its analogous property in the inverse curve with respect to the same pole ; to an asymptote in one, correspondsa circle passing through the pole and having its tangent at that point parallel to the asymptote, which the curve tends to approach as the radius diminishes ; to a point of inflexion in one curve corresponds the property of the osculating circle at the conju- gate or inverse point, passing through the pole; to a tangent in one corresponds a polar circle tangent to the other at the inverse point ; to a cusp corresponds a cusp, and the osculating circle of the inverse curve is the inverse of that of the direct curve ; so from the known properties of curves we can find the singular points of their inverse curves. I shall not dwell any longer on those properties, as they are all obvious when the principle is explained. I shall merely show what Pascal's celebrated Theorem of the Hexagon in- scribed in a conic section* becomes by inversion. If in any inverse conic section six points be taken and six polar circles be described through each two consecutive points and the pole, the intersections of each opposite pair lie in a [* See Phil. Mag. S. 3. vol. xxii. p. 168.— Edit.] 342 Mr. Stubbs on a new Method in Geometry. circle passing through the pole ; in the circle, the centre being the pole, this becomes a very remarkable theorem. In two inverse curves the differential elements of the arcs are connected inthe following manner: — d s' : d s : : r' : r, or d s' = —5- d s ; hence the differential element of the arc of a curve can be known when that of its inverse is known. This is remarkably connected with the theory of elliptic functions ; the arc of an ellipse being represented by an elliptic function of the second kind, the arc of the curve formed by the intersections of the perpendiculars to the diameters of an ellipse through their extremities, by one of the first kind, I have found by this method that the arc of an inverse central ellipse is represented by A II (w, ) — B . F . being the angle by which the amplitude of the arc is measured in the ellipse from which it is generated ; the x of the corresponding point of el- lipse being = a sin <£, y — b cos + F v(/ — Ftr = 0), viz. tt/ ^ , tty i\ nf \ 1 * _i rc 4/ a sin \J/ sin sin cos tan \f/ = a {a and b being the axes of the direct ellipse), is equal to the arc of a circle, which may be found by the following construc- tion : — let I be the intercept between the foot of the perpendi- cular from the centre on the tangent of the direct ellipse and the point of contact, P the perpendicular from the centre on the line joining the extremities of the axes of the direct ellipse, andL the line joining the extremities of the axes of the inverse ellipse; then taking a line = P, raising at its extremity a perpendicu- lar = I, and producing the line P v n until the whole line produced = L, with the common extremity O as centre, and L as radius, describe a circle, the arc of this circle in- tercepted between the other extre- mity, M, and the line joining O with the end of the perpendi- cular I, is the difference of the required arcs. The analogy of this theorem to Fagnani's with regard to the direct ellipse (by which the difference of the corresponding arcs of it is I) is obvious. The area of the inverse ellipse is an arithmetic mean between the areas of the circles described on its axes. To apply the inverse method to surfaces I will state the fol- lowing principles : if one surface be inverse to another, a tan- gent plane being drawn at one point, the tangent plane at the inverse point is had by bisecting the line joining the points by a plane perpendicular to this line, and through the line where it cuts the tangent plane to the first surface, and the inverse point we draw a plane ; it is a tangent plane at the inverse point: this is readily seen, as if through the common radius we draw any plane cutting the surfaces in two curves, these curves are inverse, and the construction which I gave for the tangents at inverse points makes this construction evident. Hence the normals at inverse points of surfaces are in the same plane and equally inclined to the common radius. From this construction for the tangent plane, it follows that if two surfaces cut at right angles their inverse surfaces cut at right angles. Hence if we describe the developable surfaces formed by the tangent planes and normals at the points of a line of curvature, since these surfaces cut at right angles their inverse surfaces cut at right angles at the inverse points of the line of curvature, but the surface formed by the tangent planes to the inverse surface at those points is touched by the inverse 344 Mr. Stubbs on a new Method in Geometry. of the corresponding surface in the first, and similarly the sur- face of normals by inverse of that in original surface ; hence it may be seen that the normals to the inverse surface along the inverse points of a line of curvature meet consecutively, or the inverse of a line of curvature on a surface is the line of curvature of the inverse surface; or if the line of curvature of a surface be known, that of its inverse surface is had by de- scribing a cone with the pole as vertex and passing through the line of curvature on direct surface, the line in which it pierces the inverse surface is a line of curvature. Hence the umbilici of one surface correspond to the um- bilici of the second ; and in general to a tangent plane cor- responds a polar sphere, and to all the singular points of one surface correspond singular points of the second. From the known theorems of surfaces of the second order may be deduced numberless theorems of surfaces of the fourth order by inversion, similarly as in plane curves. I shall con- fine myself to the inverse of the central ellipsoid, which is Fresnel's surface of elasticity in the wave theory of light. 1. By the construction for the tangent plane to an inverse surface, the tangent plane to the surface of elasticity may be found from knowing the tangent plane of the ellipsoid. 2. The lines of curvature on that surface may be found by producing the cone passing through the lines of curvature on the ellipsoid to meet it, but 3. The intersection of a confocal ellipsoid and hyperboloid determines the line of curvature on either, as they cut at right angles; hence as the equation of the inverse ellipsoid is Ou u & — 5- + tts- -\ s- = (#2 + y2, -+ 22)2> if two inverse central sur- er bl (r faces of the second order have their constants connected by the condition a2 — a'2 = b2 — bn = c2 — c'2, and they intersect, they cut at right angles, and their intersection is the line of curvature on either. 4. By subtracting the equations -^+^+-^=(*2 + y + *2)2> ™d we get in the case above mentioned, or a'" w 0"- c2 c12 ~ ' the equation to a cone of the second order: the intersection Mr. Stubbs on a new Method in Geometry. 345 of this cone with the surface inverse to the ellipsoid is the line of curvature. 5. By putting x* + y* -f s2 = a constant, we find — g- or tf , * + tb-H — 5- = const., or the intersection of the surface of o* c* elasticity and concentric sphere is a spherical conic, since it is the same as the intersection of the surface of second order and sphere. 6. The circular sections of the surface of elasticity corre- spond to those of the ellipsoid, and the umbilici of either are found by the intersection of the diameters conjugate to the circular section of the ellipsoid, as at the umbilici the ultimate section must be a circle, and therefore parallel to the circular sections. 7. As to the rectilinear generatrices of the hyperboloid of one sheet correspond circular sections in the inverse hyper- boloid, the latter has an infinite number of circular sections passing through the centre, but only two whose centre is at that point. 8. Hence the inverse hyperboloid of one sheet may be de- scribed by a moveable circle passing through a given point and moving on three others passing through the same point, which only cut in that point, and which neither lie in the same plane nor are circles of same sphere. 9. From the property that the sum of the squares of the reci- procals of three radii vectores at right angles to each other is constant in the ellipsoid, it follows that the sum of the squares of three rectangular semidiameters in the surface of elasticity is constant. 10. As the locus of the feet of perpendiculars from the cen- tre on tangent planes of an ellipsoid is a surface of elasticity ; by inversion, the locus of centres of spheres tangent to a sur- face of elasticity and passing through the centre is an ellipsoid. 11. From 8 and 5 it follows, that if planes pass through the centre of a surface of elasticity and cut out sections of a constant area, they envelope a cone of the second order, since the sum of the squares of the axes of the section is constant. The foregoing are a few of the general theorems that may be deduced by the method I propose ; they furnish a new in- stance of the duality that Chasles and others have remarked between the properties of figures ; but it is superior to any hitherto proposed, as we can by it arrive at once at the properties of curves of higher orders which surpass bur present power of analysis, from those of known curves; as from the known pro- 346 Mr. Stubbs on a new Method in Geometry. perties of curves of the second order, we come to those of the fourth with regard to polar circles, so by deducing those of the second order with regard to these latter, we might arrive at the properties of the higher curves with regard to lines. I shall not trespass on your limits any further by noticing new properties, many of which I have deduced in the paper before alluded to. I shall merely show the application of this method to physical investigation by two simple instances. 1. Since the ultimate elements of two inverse surfaces cor- responding to each other are inversely placed with regard to the common radius, by de- Fig. 6. scribing an infinitesimal cone having these ele- ments for their bases, —^ = -^ , m and m' being the masses of the bases, and dand d' the distances : hence the attraction of two infini- tesimal elements resolved in any direction are the same, or the whole attractions of the corresponding parts of two inverse surfaces on the common pole is the same. The application of this to the plane and sphere is obvious. 2. The second theorem I shall state regards the wave-theory of light. It is stated by Sir John Herschel in his Essay on Light, that the equation for determining the velocity of a wave perpendicular to a given plane z = m x + ny, is (V2 - a*) (V2 - £2) + m* (V2 - 62) (V2 - c9) + n* ( V2 - a2) and that this equation is had by an elimination which he states to be very complicated: it can be had at once by the following geometrical method. Taking with him the equation of the surface of elasticity to be R4 = a2 .r2 + i2^2 + c2z2; if we find the intersection of this with the concentric sphere, we get ■r2(a2-r2) + y*(b*-r*) + s2(c9-r2) = 0; but if we put r = to a constant, this represents a cone of second order. Now if we draw a tangent plane to this cone through the centre, the line of contact must be the axis of the curve cut out as the tangent to the sphere whose radius at r is perpendicular to it at its extremity; but this is also contained in the tangent plane, and therefore the intersection of these two planes is a tangent to the section perpendicular to its dia- meter, which is therefore an axis, but identifying the equa- tion of the tangent plane to the cone, viz. x xl (a2 —r2) + yy1 (62 — r2) + zz' (c2 — r2)= 0, with the plane Ix + my + nz = 0, I ;= x1 (a2 — r2) m =s i/ (62— r2), 8cc, x' y' z' being the coor- Mr. Joule on the Calorific Effects of Magneto-Electricity. 34? 7 dinates of the extremity of the diameter, but x12 (a3— V2) + ,/2(62__V*)+*/2(c2-V2) = 0, P ffl2 n2 M (a2_v2) + £>2-V2 + c2-V2 ~ ' which is the equation at- which he arrives when we make / = 1 . I remain, Gentlemen, yours, &c, Trinity College, Dublin, John Wm. STUBBS. Jan. 31, 1843. XLIII. On the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat. By J. P. Joule, Esq. [Continued from p. 276.] Part I. On the Calorific Effects of Magneto- Electricity. I" NOW proceeded to consider the heat evolved by voltaic -*■ currents when they are counteracted or assisted by magnetic induction. For this purpose it was only necessary to intro- duce a battery into the magneto-electrical circuit: then by turning the wheel in one direction I could oppose the voltaic current ; or, by turning in the other direction, I could increase the intensity of the voltaic- by the assistance of the magneto- electricity. In the former case the apparatus possessed all the properties of the electro-magnetic engine ; in the latter it pre- sented the reverse, viz. the expenditure of mechanical power. No. 7. 0) 2 Circuits complete. Circuits broken. Circuits complete. Circuits broken. Circuits complete. Mean circuits complete. Mean circuits broken Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of 1 turn. }600 }600 J600 }60Q J600 600 600 22 40 0 0 20 45 0 0 23 0 Mean Tempe- rature of Room. 57-43 57-45 59-40 59-40 59-10 Mean Differ- ence. 1-03- 0-41— 008- 0-51 + 1-29 + 0-06+ 0-05+ Temperature of Water. Before. After. 55-62 57-08 58-65 60-00 59-78 57-18 57-00 60-00 59-83 61-00 Loss or Gain. 1*56 gain 0-08 loss. 1*35 gain 0-17 loss. 1-22 gain. 1-38 gain, 0-12 loss. C°RSd}m 23°8' = 0-864 of current. 1*50 gain 3*8 Mr. Joule on the Calorific Effects In the preceding series I used the steel magnets previously described as the inductive force : and I had two of the large Daniell's cells in series, arranged so as to pass a current of electricity through the revolving electro-magnet and galvano- meter. The wheel was turned in the direction which it would have taken had the friction been sufficiently reduced to allow of the motion of the apparatus without assistance. The pre- caution of interpolating the experiments was again adopted. I give another series, in which everything else remaining the same, the direction of revolution was reverse, so as to increase the intensity of the voltaic electricity by superadding that of the magneto-electricity. No. 8. Circuits complete, Circuits broken. Circuits complete, Circuits broken. Circuits complete, Circuits broken. Mean Circuits complete, Mean Circuits broken. Corrected Result. Revolu- tions of Electro- Magnet per minute. J600 1-600 J600 J600 1 600 1 600 600 600 Deflec- tions of Galvano- meter of 1 turn. o / 30 15 0 0 29 40 0 0 29 50 0 0 29 55 Mean Tempe- rature of Room. 60-55 62-28 60-90 59-50 6185 60-90 Mean Differ- ence. 019+ 048 4- 003- 00 0-18- 0-49- Temperature of Water. Before. After, 59-30 62-92 59-50 59-50 60-33 60-50 62-18 62-60 62-25 59-50 63-02 60-33 Loss or Gain. 2-88 gain, 0-32 loss. 2*75 gain, 0 2-69 gain. 0-17 loss. 2-77 gain, 0-16 loss. 600 29° 55' = 1-346 of current. 2-93 gain Dismissing the steel magnets, which did not appear to have lost any of the magnetic virtue, which they possessed when newly made, I now substituted for them the large stationary electro-magnet, excited by eight of the DanielPs cells arranged in a series of four double pairs. The revolving electro-mag- net completed, as before, a circuit containing the galvanometer and 2 of DanielPs cells in series. The motive power of the apparatus was now so great that it would revolve rapidly in spite of very considerable friction. In order to give the re- of Magneto-Electricity. 349 quisite velocity it was necessary however to assist the motion by the hand. No. 9. June 1, May 31, A. M. P. M. Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of 1 turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Loss or Gain. Before. After. Circuits complete. Circuits broken. Circuits complete. Circuits broken. Uoo Uoo J 600 1 600 0 16 0 14 0 6°2-50 63-00 62-65 63-15 011 — 0-23- 011 — 0-20- 62-00 62-73 6218 62-90 62-78 62-82 62-90 63-00 0-78 gain. 0-09 gain. 0-72 gain. 0-10 gain. Mean Circuits complete. Mean Circuits broken. 1 600 1.600 15 011 — 0-21- 0'75 gain. 0-095 ga. Corrected Result. \ 600 15° = 0-543 of current. 068 gain. The following series of results was obtained with the same apparatus, by turning the wheel in the opposite direction. No. 10. Revolu- tions of Electro- Magnet per minute. Deflec- tions of Galvano- meter of 1 turn. Circuits complete Circuits broken. Circuits complete. Circuits broken. Mean Circuits complete Mean Circuits complete. Corrected Result. 600 600 600 600 600 600 35 10 0 0 37 10 0 0 36 10 Mean Tempe- rature of Room. 65-38 64-73 65-10 64 93 Mean Differ- ence. 0-62+ 075 + 1-40+ 1-23+ 1-01 + 099+ Temperature of Water. Before. 63-25 65-51 63-33 66-28 After. 68-75 65-45 69-66 66-05 Loss or Gain. 5*50 gain. 0-06 loss. 6-33 gain 0-23 loss. 5-915gain 0-145 loss 600 36D 10'= 1-845 of current. 606 gain. 350 Mr. Joule on the Calorific Effects I give two series more, in which only one cell was connected with the revolving electro-magnet, and the revolution was in the direction of the attractive forces. The magneto-electricity No. 11. 4 Revolu- tions of the Bar per minute. Deflec- tions of Galvano- meter of 1 turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Gain or Loss. Before. After. Electro-mag- net in action. Battery con- tact broken. Electro-mag- net in action. Battery con- tact broken. }eoo 1-600 j-600 j-600 2 l 70 55 70 45 67°38 6760 67-85 68-92 0?35— 0-23+ 0-67+ 0-30 + 66-37 67-77 67*85 69-18 67°80 6790 69-20 69-27 o 1*53 gain 0-13 gain 1 -35 gain 0-09 gain Mean, Electro-mag- net in action. Mean, Battery con- tact broken. 1 600 [-600 70 50 ... 0-16+ 0-26+ ... ... 1-44 gain O'll gain Corrected Result. j-600 70°'50 = 9-85 current. 1-31 gain Everything else remaining the same, I now used a battery of six cells arranged in a series of three double pairs to excite the electro-magnet. Phil. Mag. S. 3. Vol. 23. No. 153. Nov. 184-3. 2 A 854, Mr. Joule on the Calorific Effects No. 14. ft' < of. V c 3 Revolu- tions of the Bar per minute. Deflec- tions of Galvano- meter of 1 turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Gain or Loss. Before. After. Electro-mag- net in action. Battery con- tact broken. Electro-mag- net in action. Battery con- tact broken. J600 J600 j-600 1-600 o / 64 10 64 10 65°-42 65-55 65-42 65-75 o 017— 010— 0-17+ 0-03+ 65°00 65-48 65-33 65-80 65°50 65-42 65-86 65-77 0 0*50 gain 0-06 loss 0'53 gain 0-03 loss Mean, Electro-mag- net in action. Mean, Battery con- tact broken. 1 600 1 600 64 10 ... 003- 0-515 gain 0-045 loss Corrected Result. J600 64°-10' = 6-77 current. 0-56 gain I give another series obtained with a battery of two cells in series. No. 15. r h cT i— < « u c 3 1-5 Revolu- tions of the Bar per minute. Deflec- tions of Galvano- meter of 1 turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Gain or Loss. Before. /ftcr. Electro-mag- net in action. Battery con- tact broken. Electro-mag- net in action. Battery con- tact broken. J600 J600 J600 J600 o 54 54 63°-65 63-80 63-75 6407 0°43- 0-38- 020- 0-37- 63°12 63-40 63-45 63-68 63°32 63-45 63-65 0°20 gain 0*05 gain 0-20 gain 63-73 0*05 gain Mean, Electro-mag- net in action. Mean, Battery con- tact broken. 1 600 1 600 54 •- 032- 0-38- ... ... 0-20 gain 0-05 gain Corrected Result. J600 54° = 4-17 current. 0-16 gain of Magneto-Electricity. 355 The results of the preceding experiments are collected in Table III. the following table : — Series of Experiments. Current employed in exciting the Electro-Magnet. Heat Evolved. Square of Numbers proportional to those of Column 2. No. 13. 9-85 o 1-31 1-2290 No. 14. 6-77 0-56 05807 No. 15. 4-17 016 0-2203 1 2 3 4 It was discovered by Prof. Jacobi, and by myself also one or two months afterwards*, that the attraction of electro-magnets, either towards one another or for their armatures, is (below the point of saturation) proportional to the square of the electric force. The magnetism in an electro-magnet is there- fore simply as the electric force. Consequently the numbers in column 2 are proportional to the magnetic virtue of the electro-magnet. But on comparing columns 3 and 4 together, it will be seen that the heat evolved is as the square of the electricity. Therefore the heat evolved by a revolving bar of iron is proportional to the square of the magnetic influence to which it is exposed. After the preceding experiments there can be no doubt that heat would be evolved by the rotation of non-magnetic sub- stances, in proportion to their conducting power, Dr. Faraday having proved the existence of currents in such circumstances, and that their quantity is proportional, ceteris paribus, to the conducting power of the body in which they are excited. I have not made any experiments on this subject, but in the next part we shall have occasion to avail ourselves of the good conducting power of copper, in conjunction with the magnetic virtue of the bar of iron, in order to obtain a maximum result from the revolution of a metallic bar. [To be continued.!] * Annals of Electricity, vol. iv. p. 131 . Jacobi and Lenz communicated their report to the St. Petersburgh Academy in March 1839, — two months previous to the date of my paper. [f Mr. Joule requests us to insert the following erratum in the former portion of his paper : p. 27 4, for B C, C D, &c, read B C, DE, &c— Edit.] 2A2 [ 356 ] XLIV. On the so-called Calorotypes, isoitli Animadversions on the Papers of Mr. Hunt and Prof. Draper lately published in the Philosophical Magazine. By Prof. Ludwig Moser'*. WAS not a little surprised to find in vol. lviii. of these ■*• Annalen, an article by Mr. Robert Huntf of Falmouth on Thermography, and one on Calorotypes by M. Knorr, in which are communicated as discoveries facts which I had previously described at length in the same work. Mr. Hunt sets out from my first Memoir on Vision J, in which I demon- strated the existence of invisible light; he repeats the experi- ments which he read § in this Memoir, and gives them out as his own discovery. I cannot name a single experiment com- municated by either of the authors which I had not previously described, except it be that the one employs a jasper instead of an agate, which I used, or a bronze medallion instead of a piece of copper coin. In my Memoir on Vision, &c. of May 1842 (vol. lvi. of these Annalen), I communicated at page 206 [Sclent. Mem. vol. iii. p. 43] the fact, that when any body is warmed it depicts itself on metallic or glass plates ; that the same also occurs when the plate is warmed instead of the body. These expe- riments led me at first to believe that heat had some part in the production of these images, and Mr. Hunt, as also M. Knorr, who have repeated them, have stopt short at this erroneous view. Not so with me ; for the following page de- scribed the same experiment made without the intervention of any artificial temperature, adding the following observa- tions:— "The action of light wa3 therefore imitated and extended by my expe- riments; and indeed, as it appeared, by the employment of unequal tem- peratures. But this latter view could not possibly be long entertained ; it is only necessary to observe one of the above-described images, if well executed, in order to be convinced that such representations, in which the finest lines of the original may often be traced, could not possibly be pro- duced by differences of temperature, more particularly on a thin, well- conducting plate of metal. Moreover, the variety of the substances em- * From PoggendorfF's Annalen, vol. lix. part 1. Translated and com- municated by William Francis, Ph.D. f The paper referred to is a translation of Art. LXXXI. in the Phil. Mag. for Dec. 1842.— Edit. % A translation of the whole of this Memoir, and also of those on Latent Light and on Invisible Light, by M. Moser, were published in Part XL of Taylor's Scientific Memoirs, in Feb. 1843. § Mr. Hunt's paper, as just intimated, appeared in the Philosophical Magazine for December 1842. The first and very imperfect notice in this country of M. Moser's investigations was communicated at the Meeting of the British Association in June of the same year. It related solely to ex- periments and views detailed in the first of the three Memoirs. — Edit, Prof. L. Moser on the so-called Calorotypes. 357 ployed forms a great objection to this view of the subject. It was there- fore necessary to try whether the same phenomena could not be pro- duced without the application of heat, and in this I succeeded." [Scien- tific Memoirs, vol. iii. p. 443.] In the Addendum to this Memoir [Scient. Mem. vol. iii. p. 459], in which I advanced the hypothesis that the depict- ing of the bodies wa6 due to a light proper to themselves, I have spoken of the auxiliary influence of heat in such a man- ner as will I hope settle this point. Bodies become luminous when heated ; that is, they emit light of the refrangibility of ordinary light. After this it will hardly be admitted that this emission of light takes place suddenly; besides, the experi- ments prove the contrary; they show that light is radiated at all temperatures from bodies, that its intensity increases and its refrangibility decreases as the temperature becomes higher. According to my experiments the invisible rays of light pass very readily through aqueous solutions of various kinds, and through different oils, but they decidedly do not pass through the thinnest plates of glass, mica, amber or rock salt. [I have only recently made some experiments with the latter sub- stance.] But if the temperature be raised, they pass very readily both through glass and mica, which is perfectly in accordance with the supposition that their intensity is increased and their refrangibility approximated to those of visible light. [Substances such as white glass, mica, &c., consequently lose the character of perfect transparency ; they retain it only for a certain group of rays of light.] Should it be concluded from the influence of heat on light, — corresponding so closely in its other properties to other phy- sical forces, — that light and heat are identical, then let us see further on how the remaining phaenomena are to be explained. I would merely impress on the reader not to be led astray by the mass of proofs which might perhaps be enumerated in favour of such an identity ; they are all of them nothing more than variations upon the old fact of the incandescence of bo- dies at an elevation of temperature. With this I may at present take my leave of Mr. Hunt; the very title of his paper conveys the opinion of its being dependent on the in- fluence of heat, and he has not even entered into the subject so far as he read it in my first Memoir. As I have stated above, he has not devised a single new experiment, for even those which appear to him sufficiently important to be adopted as the running head to his paper, " Art of copying engravings from paper on metallic plates by means of heat," will be found nearly word for word in these A?male?i> vol. lvii. p. 570*. * Published in 1842. 358 Prof. L. Moser on the so-called Calorotypes. It is that experiment in which I caused a seal to depict itself on mercury with which a pure or silvered copper-plate had been coated, and afterwards produced the image in the iodine vapours. I now turn to the calorotypes of M. Knorr. As soon as I had found from my experiments the fact that the actions of the bodies were manifested without any elevation of temperature, I operated at the ordinary temperature and never employed heat, for the phenomenon appeared already to belong to a somewhat complicated class, which needed not to be rendered more intricate by the introduction of any foreign force. In one case only did I depart from this rule, and that was in order to determine the colour of the latent light of oxygen. Since the affinity of several metals for this gas is increased by heat, I warmed plates of copper and brass, on which the invisible rays had acted, and on their becoming iridescent, I obtained the images by means of the various colouring. I communicated these results to several persons about the 1 8th Sept. 1842, and among others to the Editor of these Annalen (Prof. PoggendorfF), who had the kindness to bring them before the notice of the Berlin Academy of Sciences, and to cause their publication in the Monthly Proceedings*. Now these are the calorotypes of M. Knorr, only, as I conceive, obtained in a more advantageous manner; for M. Knorr heats the plate with the body to be depicted on it until the former becomes iridescent. The image which is formed under these circumstances I have long been acquainted with, but even now in my opinion it affords no proof. If, for instance, a body is placed on the plate, at some points it will be in contact, at others not ; the oxygen to which the iridescence must be ascribed will be present in some places in sufficient quantity, or have free access, at other points not ; moreover, some parts of the plate will acquire a higher temperature on being heated than the others, so that if after all we see the image of a body on a plate, it may be owing to several cir- cumstances. In my experiments I have avoided these, for I allow the body in contact or at a distance to act first on the metallic plates by its peculiar light, and then heat the plate uniformly, the body to be depicted being absent, and the oxygen having free access. I may therefore assert that the calorotypes of M. Knorr are no new discovery, and that they do not in the least alter the state of the case; for the conclu- sions which might be drawn from the images produced by iridescence I have already communicated, while M. Knorr contents himself with the fact. * See Poggendorff's Annalen, vol. Iviii. Prof. L. Moser on the so-called Calorotypes. 359 As the question as to the identity of light and heat is now frequently discussed, I will communicate a fact on this sub- ject which in my opinion will prove decisive : it had escaped me when writing the paper on the question of the identity contained in these Annalen, vol. lviii. p. 105. Heat, as is well known, is emitted from bodies to which it has been conveyed, presupposing that it was not employed to produce a chemical change in them: the light, on the contrary, which effected that peculiar change on the surface c bodies which subse- quently is best rendered perceptible i»y the condensation of vapours, is not again radiated, and it must therefore be as- sumed that it has become extinct with this action. I have made numerous experiments to transfer the effect of the light from one plate to the other; sometimes I took iodized silver plates with a not yet perceptible image from the camera ob- scura, placed them in contact for a short or long period with other iodized plates, or with plates of other metals ; some- times I employed for the same purpose metallic plates on which the image produced by imperceptible light was in a far more advanced state. As soon as I became acquainted with the behaviour of the oils I tried them, and separated the two plates employed in the experiment by a layer of oil ; in no case have I succeeded in detecting even a trace of transfer of an image on to another plate. The light which has produced its effect radiates accordingly no more. Now what shall we say to the experiments of Dr. Draper, in which this re-radiation is assumed as something self-evident, and upon which indeed is principally founded a theory of ti- thonic rays ? I may inform those philosophers who are not acquainted with the investigations of Dr. Draper, that these new kind of rays are nothing else than the chemical rays which have often been said to have been discovered in the solar spec- trum. Dr. Draper has just as much discovered them, as the imperceptible and latent light; both of which species of light he likewise lays claim to, without there having been the least mention of them in his papers. But to keep to the subject, it is impossible not to be astonished at a physicist who con- ceives he has discovered a new force — the tithonic, and as- serts that it radiates without even having made one single ex- periment to prove this. Dr. Draper knows no more than what every person who has been engaged in experiments on light is aware of, that the image of an iodized silver plate, as it comes from the camera obscura, disappears after a time, and can no more be made to appear in the vapours of mercury. Does it hence follow that the image radiates from the plate ? This is so little the case, that, according to my experience, 360 Professor Sir William Rowan Hamilton on the disappearance of the image must rather be ascribed to a peculiar action of the oxygen of the atmosphere, on which subject I recently made a preliminary communication to Sir David Brewster and Professor Magnus, and intend shortly to publish the details in these Annalen. Dr. Draper is so con- vinced of the radiation of these images, that he pretends to preserve them by covering them, and in this scientific man- ner has discovered specific light analogous to specific heat ! Konigsberg, 30th April, 1843. XLV. On an Expression for the Numbers of Bernoulli, by means of a Definite Integral ; and on some connected Pro- cesses of Summation and Integration. By Sir William Rowan Hamilton, LL.D., P.R.I.A., Member of several Scientific Societies at Home and Abroad, Andrew^ Professor of Astronomy in the University of Dublin, and Royal Astro- nomer of Ireland. THE following analysis, extracted from a paper which has been in part communicated to the Royal Irish Academy, but has not yet been printed, may interest some readers of the Philosophical Magazine. 1. Let us consider the function of two real variables, m and n, represented by the definite integral P °° L /sin x\ m y =/ dx\ I coswx; . . (1.) in which we shall suppose that m is greater than zero; and which gives evidently the general relation Jm, — n "m, n* By changing m to m + 1 ; integrating first the factor x~m~ d x, and observing that x~m sin xm^"1 cos n x vanishes both when x = 0, and when x = oo ; and then putting the differential coefficient -, — (sin xmJt cos n x) under the dx ' form | sin xm{(m + 1 + n) cos (n x + x)-+ (m+l—ri) cos (nx — x) }; we are conducted to the following equation, in finite and par- tial differences, 2 m w . , ■" = (m + 1 4- n) y . . +(m + l—n)y •, (2.) and if we suppose that the difference between the two va- riables on which y depends is an even integer number, this equation takes the form an Expression for the Numbers of Bernoulli. 361 The same equation in differences (2.) shows easily that u . , =0, when n = or > m + 1, if y = 0, when ra — 1 > w* ; «* m, n — 1 but, by a well-known theorem, which in the present notation becomes Ki$T (4,,) it is easy to prove, not only that but also that ^i,« = 0' if »2>J; (60 we have therefore, generally, for all whole values of?«> 1, and for all real values of n, w =0, unless n <-m . . . . (7.) 2. If then we make Tm = ^^jw,m-2/t("" 0 » .... (8.) the sign 2 indicating a summation which may be extended from as large a negative to as large a positive whole value of Jc as we think fit, but which extends at least from Jc = 0 to Jc = mt m being here a positive whole number ; this sum will in general (namely when m > 1) include only m — 1 terms different from 0, namely those which correspond to Jc = 1, 2, .... m — 1 ; but in the particular case m = 1, the sum will have two such terms, instead of none, namely those answer- ing to Jc = 0 and Jc = 1, so that we shall have Multiplying the first member of the equation in differences (3.) by (— t) , and summing with respect to Jc, we obtain m T , ,, m being here any whole number > 0. Multiplying and summing in like manner the second member of the same equation (3.), the term mym mjt-2-2k°^ tnat memDer gives — m t T , because we may change Jc to Jc + 1 before effect- ing the indefinite summation ; Jc ym m _ 2 k gives t -j- T^ ; and(l-Jc)ymm + 2_2ligivest2TFTm; but -^Tffl + H^TM=(l+f^(l+/rTw; 362 Professor Sir William Rowan Hamilton on therefore M(l+,)--1Tffl + 1 = -n^(l+,r»*T„. . (10.) This equation in mixed differences gives, by (9.), T „i (1 + y (_±_)—ilJ=i. (u) m 4> 1.2.3... {m- 1) \d log t) 1 + *' * K } the factorial denominator being considered as = 1, when m = 1, as well as when m = 2. If ?w > 1, we may change j ( 2 ^ — — - to - -, from which it only differs by a constant; and 1 + t 1 + t J J h 2 then by changing also t to e , and multiplying by — , we ob- tain the formula : (12.) (eh+l)m (ay1-1 . 1.2.3... {m- 1) \dh) (e + l) 2 m-l A» /sinaAw, *v* , ' . 7T (A)l»/0 V or / v " which conducts to many interesting consequences. A few of them shall be here mentioned. 3. The summation indicated in the second member of this formula can easily be effected in general ; but we shall here consider only the two cases in which m is an odd or an even whole number greater than unity, while h becomes = 0 after the m — 1 differentiations of (ek -f l)-1, which are directed in the first member. When m is odd (and greater than one), each power, such as / eh\k in the second member, is accompanied by another, namely ( — e )m ~ , which is multiplied by the cosine of the same multiple of tc\ and these two powers destroy each other, when added, if h — 0: we arrive therefore in this manner at the known result, that \Th) (** + !)-1 = 0, when h = 0, if p > 0. . . (13.) On the contrary, when m is even, and h m 0, the powers (— el) and ( — el)m ~ are equal, and their sum is double of either ; and because (— 1);'{1 — 2 cos 2 # + 2 cos kx — ... + (-ir-12cos(2px-2x)\ = -COS(2Px-"\ * J COS X by making m = 2p we arrive at this other result, which per- haps is new, that (if p > 0 and h — 0) an Expression for the Numbers of Bernoulli. (d)2p ~Vi iri--i-g-8~(gg-ir *1» y"*00 , /sin #\ ^ cos (2 p x — x) 0 \ x J cos # 363 (14.) -1 Developing therefore (e -f 1) according to ascending powers of h ; subtracting the development from — , multiply- x ing by ^, and changing ^ to 2 /* ; we obtain h eh-e~h _ 2 P°> dx <»/hsmx\2p eh -u e~h~ **J 0 cos x Q>) 1 V x ) (15.) cos (2p x — x); that is, effecting the summation, and dividing by h , 1 eh-e~h _r2 h J1 a „~h ~~ n X ^a; sin # (1 — .A a? sin a? ) sin x cos 2x + h x sin 1 — 2 h x or, integrating both members with respect to h 4 » (16.) /„ hdhl_ 0 A A /^tan^log^/i 1 o o T o 1 + h x sin 2 a? + h x sinx a?- sin2^ + Zr x~ sin# (17.) It might seem, at first sight, from this equation, that the integral in the first member ought to vanish, when taken from h = 0 to h = 00 ; because, if we set about to develope the second member, according to descending powers of h, we see that the coefficient of h° vanishes; but when we find that, on the same plan, the coefficient of h~ is infinite, being = — / d x, we perceive that this mode of development is here inappropriate : and in fact, it is clear that the first mem- ber of the formula (17.) increases continually with //, while h increases from 0. 4. Again, since = 4,(2^)- 4, W, tf*(*iW-TT^J • • (18-) /:+! e" - 1 we shall have (for p > 0) the expression 364 Professor Sir William Rowan Hamilton on A ==21"2^"yc0^(giLf)2/,coS(2^^^) 2P 22*-W<> V * ) 3o7^ ' ' V9') if, according to a known form of development, which the fore- going reasonings would suffice to justify, we write -xL_ + _i=l +A2A2 + A4/*4 + A6/*G+&c. . (20.) e — 1 If p be a large number, the rapid and repeated changes of COS ( 2 79 T i v i sign of the numerator of the fraction i-J—. 1 produce n COS X l nearly a mutual destruction of the successive elements of the integral (19.), except in the neighbourhood of those values of x which cause the denominator of the same fraction to va- nish; namely those values which are odd positive multiples of — (the integral itself being not extended so as to include SB any negative values of %). Making therefore jra(S»-.l)-I + C0) . . . . (21.) in which i is a whole number > 0, and w is positive or nega- tive, but nearly equal to 0 ; we shall have cos (2p x — x) = (— 1)^ T * ~ sin (2p co — co), exactly, and cos x = (— I)*co, nearly ; changing also 2P to the value which it has when w = 0, namely /2\2p ~2v I — j (2 i — 1) ; and observing that /<>> 7 sin (2 p co — co) , d co v-£ '- = 7r, nearly, . . (22.) even though the extreme values of co may be small, if p be very large ; we find that the part of A2 , corresponding to any one value of the number z, is, at least nearly, represented by the expression {-\f-l2{2i-\)-2p (2^-1)^ 5 • • • (23.) which is now to be summed, with reference to z, from i — 1 to i = oo. But this summation gives rigorously the relation s(0><-ir,'=(i-8-*')S(07r2'' . (24.) we are conducted, therefore, to the expression e-^y an Expression for the Numbers of Bernoulli. 365 A2/,= (-l)'-12(2,)-2"2(l.)7i-^) . . (25.) as at least approximately true, when the number^? is large. But in fact the expression (25.) is rigorous for all whole values of p greater than 0 ; as we shall see by deducing from it an ana- logous expression for a Bernoullian number, and comparing this with known results. S. The development _L_ + | U h- \ + B,^ - B3T-^ + ftftj (26.) being compared with that marked (20.), gives, for the pth Bernoullian number, the known expression B2„_1 = (-l)i;-11.2.3.4...2i;A2i,;. . (27.) and therefore, rigorously, by the equation (19.) of the present paper, B (-l)p~11.2...2p (28.) /*" d /sin x\2p cos {2 p x - x) m J 0 \ X ) cos X a formula which is believed to be new. Treating the definite integral which it involves by the process just now used, we necessarily obtain the same result as if we combine at once the equations (25.) and (27.) • We find, therefore, in this manner, that the equation (in which, by the notation here employed, is at least nearly true, when p is a large number ; but Euler has shown, in his Jnstitutiones Calculi Differ entialis (vol. i. cap. v. p. 339. ed. 1787), that this equation (29.) is rigorous, each member being the coefficient of u p in the development of — (1 — w u cot 7r u). [See also Professor De Morgan's Treatise on the Diff. and Int. Calc, * Library of Useful Knowledge/ part xix. p. 581.] The analysis of the present paper is therefore not only verified generally, but also the modifications which were made in the form of that definite integral which entered into our rigorous expressions (19.) and 366 Sir W. R. Hamilton on the Numbers of Bernoulli. (28.) for A2 and B2 „__ j» by the process of the last article, (on the ground that the parts omitted or introduced thereby must at least nearly destroy each other, through what may be called the " principle of fluctuation,") are now seen to have produced no ultimate error at all, their mutual compensation being perfect; a result which may tend to give increased confidence in applying a similar process of approximation, or transformation, to the treatment of other similar integrals; although the logic of this process may deserve to be more closely scrutinized. Some assistance towards such a scrutiny may be derived from the essay on (i Fluctuating Functions," which has been published by the present writer in the second part of the nineteenth volume of the Transactions of the Royal Irish Academy. 6. It may be worth while to notice, in conclusion, that the property marked (7.) of the definite integral (1.), enables us to . cos^px — x) ^ . . . . .A. change — to sin 2p x tan x, in the equations(14.), (15.), (19.)> (28.); so that the pth Bernoullian number may rigorously be expressed as follows : — n ,(-l)p-1.1.2...3p »2P-l- 22^-1(22^-l)* /»" . (s\nx\2p . n I dx\ J sin 2 p x tan x ; under which form the preceding deduction of its transfor- mation (29.) admits of being slightly simplified. The same modification of the foregoing expressions conducts easily to the equation (30.) log « = e + e vfo d* tan x tan ' h sin x sin 2 x x — h sin x cos 2 x in which tan is a characteristic equivalent to arc tang., and which may be made an expression for log sec x, by merely changing the sign of h in the last denominator; and from this equation (31.) it would be easy to return to an ex- h e — e pression for the coefficients in the development of — - — e + e or in that of tan h, and therefore to the numbers of Ber- noulli. Those numbers might thus be deduced from the Mr. E. Solly on the Colour of Solutions of Chloride of Copper. 367 following very simple equation : 7rlogsec# = / dxy tan x; . . . (32.) in which y is connected with x and h by the relation sin y (h sin x\2 . • ,0 y r=( — J. . . . 33. sin (2 x — 3/) \ x / v ' Observatory of Trinity College, Dublin, October 6, 1843. XL VI. Note o? i the Changes in Colour exhibited by solutions of Chloride of Copper. By E. Solly, F.R.S. In a Letter to Richard Taylor, Esq. THE colour of the different salts of copper varies, it is well known, according to the proportion of water which they contain; thus the sulphate when anhydrous is perfectly white; whilst in its ordinary crystallized state, when containing five atoms of water, it is of a deep blue colour; most of the other soluble salts of this metal exhibit similar changes in colour ac- cording to their state of hydration, none perhaps exhibit them in a more remarkable manner than the chloride. I was re- cently misled, through ignoranceof one of the conditions which modify these changes ; and as the colour of solutions of copper has sometimes been supposed to indicate the state in which the metal existed in solutions, I have thought that a brief state- ment of the appearance of chloride of copper under different circumstances might save others from falling into the same error. Dry chloride of copper is of a yellowish-brown colour ; when dissolved in a small quantity of water it forms a dark brown solution ; if further diluted it becomes grass-green ; and if more water yet be added, the solution becomes bright blue. If, on the other hand, a blue and dilute solution be gradually evaporated, it passes through the various shades of green-blue, blue-green, green and brown. When in place of slowly eva- porating a blue and dilute solution it is suddenly heated, it immediately begins to change colour, and when boiling is bright green. This effect appears to be due to heat alone; that it is quite distinct from the change from blue to green, caused by concentrating the solution, is proved by the fact, that if a blue solution be made to boil in a flask it becomes perfectly green whilst boiling, but regains its original blue colour if allowed to cool ; this change from blue to green, and vice versa, may be repeated any number of times at pleasure, by alternately heating and cooling the solution, and without concentrating or diluting it. 368 Royal Society. When solutions of common salt and sulphate or nitrate of copper are mixed together at common temperature, the solu- tion remains blue; on applying heat to it, it gradually changes to green, and if allowed subsequently to cool, regains its ori- ginal blue colour. It has been supposed from this appear- ance that common salt does not at common temperature de- compose sulphate or nitrate of copper, but that at the boiling temperature it is able to effect their decomposition, and that the green colour of the boiling solution is evidence of the pre- sence of chloride of copper. The facts above stated, however, show that the green colour which the solution acquires when heated is no proof of the formation of chloride of copper, as a dilute solution of the chloride itself is blue when cold, and becomes green when heated. When the mixed solution of nitrate of copper and common salt is evaporated, it becomes permanently green ; hence it was supposed that under these circumstances the salts completely decomposed each other, whilst, when the solutions were dilute, the affinities remained so balanced, that a slight increase or decrease in the tempe- rature was sufficient to determine the arrangement of the acids and bases. The truth however evidently is, that the chloride is formed when the cold solutions are mixed, and becomes permanently green from concentration, like the blue dilute solution of the chloride. That this is really the case is also easily shown by taking, in place of solutions of the two salts, the dry sulphate of copper and chloride of sodium in powder ; mixing them and adding a small quantity of water, a deep green solution of chloride of copper, together with sulphate of soda, is immediately formed. When sulphate of copper is de- composed by chloride of calcium or barium, a blue or green solution of chloride of copper results, after separating the sul- phate of lime or barytes, the colour of which depends on the strength of the solutions originally employed ; if weak and blue, it acquires a green colour when heated; and if concen- trated, becomes permanently green. October 15th, 1843. XLVII. Proceedings of Learned Societies. ROYAL SOCIETY. [Continued from p. 57«] March 30, HPHE following papers were read, viz.— 1843. ■*- 1. " Researches into the Structure and Develope- ment of a newly discovered parasitic Animalcule of the Human Skin, the Entozoon folliculorum." By Erasmus Wilson, Esq., Lec- turer on Anatomy and Physiology at the Middlesex Hospital. Com- municated by R. B. Todd, M.D., F.R.S. Mr. Erasmus Wilson on the Entozoon folliculorum. 369 While engaged in researches on the minute anatomy of the skin and its subsidiary organs, and particularly on the microscopical com- position of the sebaceous substance, the author learned that Dr. Gustow Simon of Berlin had discovered an animalcule which inha- bits the hair follicles of the human integument, and of which a de- scription was published in a memoir contained in the first Number of Midler's Archiv for 1842. Of this memoir the author gives a translation at full length. He then states that, after careful search, he at length succeeded in finding the parasitic animals in question, and proceeded to investigate more fully and minutely than Dr. Simon had done the details of their structure, and the circumstances of their origin and developement. They exist in the sebaceous follicles of almost every individual, but are found more especially in those per- sons who possess a torpid skin ; they increase in number during sickness, so as in general to be met with in great abundance after death. In living and healthy persons, from one to three or four of these entozoa are contained in each follicle. They are more nume- rous in the follicles situated in the depression by the side of the nose ; but they are also found in those of the breast and abdomen, and on the back and loins. Their form changes in the progress of their growth. The perfect animal presents an elongated body, di- visible into a head, thorax, and abdomen. From the front of the head proceed two moveable arms, apparently formed for prehension : and to the under side of the thorax are attached four pairs of legs, termi- nated by claws. The author distinguishes two principal varieties of the adult animal ; the one remarkable for the great length of the abdomen and roundness of the caudal extremity ; whilst the other is characterized by greater compactness of form, a shorter abdomen, and more pointed tail. The first variety was found to measure, in length, from the one-lOOth to the 45th, and the second, from the one-160th to the 109th part of an inch. The author gives a minute description of the ova of these entozoa, which he follows in the successive stages of their developement. The paper is accompanied by numerous drawings of the objects de- scribed. 2. " On Factorial Expressions, and the Summation of Algebraic Series." By W. Tate, Esq. Communicated by the Rev. Henry Moseley, M.A., F.R.S., &c. This paper, which is wholly analytical, contains an investigation of certain general methods for the summation of algebraic series, which have led the author to the discovery of some curious and elegant pro- positions relative to factorials and the decomposition of fractions ; and also to a new demonstration of Taylor's theorem. 3. " Notice of the Comet ;" in a Letter from Captain John Grover, F.R.S., addressed to P. M. Roget, M.D., Sec. R.S., and dated from Pisa, March 21st, 1843. The author states that at Pisa, on Friday, the 17th of March, 1843, at eight o'clock in the evening, he saw a luminous arc in the heavens, extending from a spot about a degree to the south of Rigel to some clouds which bounded the western horizon. It was about 40 minutes Phil. Mag, S. 3. Vol. 23. No. 153. Nov. 1843. 2 B 370 Royal Society: Mr. Newport on the in width ; the edges sharply and clearly defined. On the 20th of March, the author could distinctly trace the extremity of the lumi- nous streak, which he concluded was the tail of a comet, below the lower part of the constellation Orion, and reaching to the star y\ Eri- dani ; while the stars I and e Eridani were distinctly seen with the naked eye through the coma. From r\ Eridani, it extended 47° 30' to a spot nearly equidistant from ■% Ononis and jj Leporis*. 4. " Variation de la Declinaison et Intensite Horizontales Mag- netiques observees a Milan pendant vingt-quatre heures consecu- tives le 18 et 19 Janvier, et le 20 et 25 Fevrier 1843." Par C. Carlini, For. Mem. R.S. 5. A paper was also in part read, entitled " On the general and minute Structure of the Spleen in Man and other Animals." By William Julian Evans, M.D. Communicated by P. M. Roget, M.D., Sec. R.S. April 6. — The following papers were read, viz. — 1. " On the general and minute Structure of the Spleen in Man and other Animals." By William Julian Evans, M.D. Communi- cated by P. M. Roget, M.D., Sec. R.S. After adverting briefly to the discordant opinions of Malpighi, Ruysch, and others regarding the structure of the spleen, the author proceeds to detail the results of the investigations on this subject, in which he has been for many years engaged. According to his ana- lysis, the following are the component parts of this organ : — first, a reticulated fibro-elastic tissue ; secondly, a pulpy parenchyma, con- taining the Malpighian glands and the splenic corpuscles ; thirdly, distinct cellular bodies ; fourthly, the usual apparatus of arteries, veins, lymphatics and nerves ; fifthly, certain fluids ; and lastly, the membranes or tunics by which it is invested. He describes the cells of the spleen as being formed of a lining membrane, continued from that of the splenic vein, and strengthened by filaments of the fibro-elastic tissue. The splenic vein communi- cates with these cells, at first by round foramina, then by extensive slits resembling lacerations ; and it ultimately loses itself entirely in the cells. The cells themselves communicate freely with one another, and also with the veins of the parenchyma ; and may therefore be considered as in some measure continuations of the veins. This structure constitutes a multilocular reservoir of great extensibility, and possessing great elastic contractility ; properties, however, which exist in a much less degree in the human spleen than in that of her- bivorous animals ; in which animals the cellated structure itself is much more conspicuous, and predominates over the parenchymatous portion. As the splenic artery has no immediate communication with the cells, these latter may be filled much more readily by in- jection from the vein than from the artery. In the ordinary state of the circulation, the blood, which has passed into the cells from the veins, is pressed into the branches of the splenic veins by a force de- rived from the elasticity of the fibro-elastic tissue which surrounds [* Other notices of the comet have appeared, in the present volume, pp. 54, 147, 311 ; and in the preceding volume, p. 3^3.] Development and Circulation of the Myriapoda. 371 the cavities of the cells, thus constituting a vis-a-teryo, which con- tributes to propel the blood onwards in its circulation through the liver. Should there arise, however, any obstructing cause which the resilience of the spleen is unable to overcome, a regurgitation must take place, leading to a congestion both in the mesenteric and splenic veins. The spleen may thus serve as a receptacle for the blood of the abdominal circulation during any temporary check to its free passage into the vena cava ; a purpose which is more fully answered in herbivorous animals in whom the abdominal circulation is more extensive, and the spleen is of larger dimensions and greater elas- ticity. The splenic corpuscles are thickly scattered throughout the cellu- lar parenchyma of this organ ; and from each corpuscle there arises a minute lymphatic vessel; the interlacing of adjacent lymphatics giving rise to a fine and extensive net-work. The trunks of these vessels enter into the Malpighian glands, and again ramifying, form a lymphatic plexus in the interior of these bodies. The fluid con- tents of these vessels, which had been before pellucid, is now found to contain white organic globules, similar in every respect to those observed in the fluid of lymphatic glands in other parts of the body. The author considers the secretion of this fluid, which appears to be identical with the contents of the lymphatic glands, as being the peculiar function of the splenic parenchyma. A few illustrative drawings and diagrams accompany this paper. 2. "On the Structure and Developement of the Nervous and Circu- latory Systems, and on the existence of a complete Circulation of the Blood in Vessels in the Myriapoda and the Macrourous Arachnida." By George Newport, Esq. Communicated by P. M. Roget, M.D, Sec. R.S. This paper is the first of a series which the author proposes to submit to the Royal Society on the comparative anatomy and the developement of the nervous and circulatory systems in articulated animals. Its purpose is, in the first place, to investigate the minute anatomy of the nervous system in the Myriapoda and the Macrou- rous Arachnida, and more especially with reference to the structure of the nervous cord and its ganglia ; and thence to deduce certain conclusions with respect to the physiology of that system and the reflex movements in vertebrated animals ; secondly, to demonstrate the existence of a complete system of circulatory vessels in the Myriapoda and Arachnida ; and thirdly, to point out the identity of the laws which regulate the developement of the nervous and circu- latory systems throughout the whole of the Articulata, and the de- pendence of these systems on the changes which take place in the muscular and tegumentary structures of the body, as, in a former paper, he showed was the case with regard to the changes occurring in the nervous system of true insects. The first part of the paper relates to the nervous system. A de- scription is given of this system in the Chilognatha, which the au- thor was led, by his former investigations, to regard as the lowest order of the Myriapoda, and approximating most nearly to the 2B2 372 Royal Society : Mr. Newport on the Annelida. He traces the different forms exhibited by the nervous system in the principal genera of that order, the most perfect of which are connected on the one hand with the Crustacea, and on the other with true insects. Passing from these to the Geophili, the lowest family of the Chilopoda, which still present the vermiform type, the nervous system is traced to the tailed Arachnida, the Scorpions, through Scolopendra, Lithobius and Scutigera ; the last of which tribes connects the Myriapoda on the one hand with the true insects, and on the other with the Arachnida. The brain and the visceral nerves, the coverings and structure of the cord and ganglia, and the distribution of the systemic nerves are examined in each genus, but more particularly in the Scorpion, in which the nerves of the limbs are traced to the last joints of the tarsi, and those of the tail to the extremity of the sting. Especial attention is bestowed on the structure of the cord and its ganglia, and their de- velopement during the growth of the animal. In the lowest forms of the Iulidse, in which the ganglia are very close together, and hardly distinguishable from the non-ganglionic portions of the cord, the author has satisfactorily traced four series of fibres, a superior, and an inferior one, and also a transverse and a lateral series. The superior series, which he formerly described in insects as the motor tract, he has assured himself is distinct from the inferior, which he regarded as the sensitive tract ; this evidently appears on examining the upper and under sides of a ganglionic enlargement of the cord. On the upper surface the direction of the fibres is perfectly longitu- dinal ; while the fibres on the under surface are enlarged, and cur- vilinear in their direction. But he remarks that it is almost impos- sible to determine by experiment whether these structures are sepa- rately motor and sensitive, as formerly supposed, or whether they both administer to these functions by an interchange of fibres. These two series appear also to be separated in each ganglionic enlargement of the cord by the third series, constituting the transverse or com- missural fibres, which pass transversely through the ganglia, and of which the existence was first indicated by the author in his paper on the Sphinx ligustri, published in the Philosophical Transactions for 1834*. The author states that, in addition to these, there is in each half of the cord another and more important series of fibres, which constitute a large portion of the cord, but of which the existence has hitherto entirely escaped observation. This series forms the lateral portion of each half of the cord, and differs from the superior and inferior series in the circumstance, that while those latter series are traceable along the whole length of the cord to the subcesophageal and cerebral ganglia, the former series extends only from the posterior margin of one ganglion to the anterior margin of the first or second beyond it ; thus bounding the posterior side of one nerve and the an- terior of another, and forming part of the cord only in the interval be- tween the two nerves. From this circumstance, the author designates the fibres of this series,Jibres of reinforcement of the cord. Every nerve proceeding from a ganglionic enlargement is composed of these four [* An abstract of which was given in Phil. Mag. S. 3. vol. vi. p. 55.] Development and Circulation of the Myriapoda. 373 sets of fibres, namely, an upper and an under one, communicating with the cephalic ganglia ; a transverse or commissural, which com- municates only with corresponding nerves on the opposite side of the body ; and a lateral set, which communicates only with nerves from another ganglionic enlargement on the same side of the body, and which forms part of the cord in the interspace between the gan- glia. The author had long suspected that this latter set of fibres existed ; but he had never, until lately, ascertained their presence by actual observation. Their action seems fully to account for the re- flected movements of parts both anterior and posterior to an irritated limb ; as that of the commissural set does the movements of parts situated on the opposite side of the body to that which is irritated. In the ganglia of the cord in lulus and Polydesmus, the fibres of the inferior longitudinal series are enlarged and softened on entering the ganglion, but are again reduced to their original size on leaving it; thus appearing to illustrate the structure of ganglia in general. In the developement of the ganglia and nerves in these genera, and also in Geophilus, the same changes take place as those which were formerly described by the author as occurring in insects ; namely, an aggregation of ganglia in certain portions of the cord, and shift- ing of the position of certain nerves, which at first exist at ganglionic portions of the cord, but afterwards become removed to a non- ganglionic portion. The nervous cord is elongated, in order that it may keep pace with the growth of the body, which is periodically acquiring additional segments : that this elongation takes place in the ganglia is proved by these changes of position in the nerves lying transversely across the ganglia. The author infers from these facts, that the ganglia are centres of growth and nourishment, as well as of reflex movements, and that they are analogous to the enlarge- ments of the cord in the vertebrata. A series of experiments on the lulus and Lithobius are next re- lated; the result of which shows that the two supra-oesophageal gan- glia are exclusively the centres of volition, and may therefore strictly be regarded as performing the functions of a brain : so that when these ganglia are injured or removed, all the movements of the ani- mal are of a reflex character. When, on the other hand, these gan- glia are uninjured, the animal movements are voluntary, and there exists sensibility to pain : there is, however, no positive evidence that the power of sensation does not also reside in the other ganglia. The second part of the paper relates to the organs of circulation. In all the Myriapoda and Arachnida the dorsal vessel or heart is di- vided, as in insects, into several compartments, in number corre- sponding to the abdominal segments. Its anterior portion is divided, immediately behind the basilar segment of the head, into three di- stinct trunks. The middle portion, which is the continuation of the vessel itself, passes forwards along the oesophagus, and is distributed to the head itself; while the two others, passing laterally outwards and downwards in an arched direction, form a vascular collar round the oesophagus, beneath which they unite in a single vessel, as was 374 Royal Society. first noticed by Mr. Lord in the Scolopendra. This single median vessel lies above the abdominal nervous cord, and is extended back- wards throughout the whole length of the body as far as the termi- nal ganglia of the cord, under which it is subdivided into separate branches accompanying the terminal nerves to their final distribu- tion. Immediately anterior to each ganglion of the cord, this vessel gives off a pair of vascular trunks ; and each of these trunks is di- vided into four arterial vessels, one of which is given to each of the principal nerves proceeding from the ganglion, and may be traced along with it to a considerable distance. Of these, the vessel situated most posteriorly is again connected with the great median trunk by means of a minute branch, so that the four vessels on each side form, with their trunks, a complete vascular circle above each gan- glionic enlargement of the cord. Besides these, which may be re- garded as the great arterial trunk and vessels conveying the blood directly from the anterior distribution of the heart to the limbs and inferior surface of the body, the author has also discovered a pair of large arterial vessels in each segment, originating directly from the posterior and inferior surface of each chamber of the heart. These vessels he has named the systemic arteries ; and in the Scolopendra he has traced them from the great chamber of the heart, which is situated in the penultimate segment of the body, to their ultimate distribution and ramification in the coats of the great hepatic vessels of the alimentary canal. After the blood has passed from the arteries, it is returned again to the heart in each segment of the body by means of exceedingly delicate transparent vessels, which pass around the sides of the seg- ments and communicate with the valvular openings of each cham- ber of the heart at its upper surface, where the valvular openings are situated, not only in all the Myriapoda, but also in the Scorpio- nidae. In Scorpions, the circulatory system is more complete and important than even in the Myriapoda. The heart, divided as in Myriapods into separate chambers, is lengthened out at its posterior extremity into a long caudal artery, and gives off a pair of systemic arteries from each chamber, precisely as in the Myriapoda. These arteries not only distribute their blood to the viscera, but send their principal divisions to the muscular structures of the inferior and lateral parts of the body, as well as to the pulmonary sacs. At the anterior part of the abdomen, the heart becomes aortic, descends suddenly into the thorax, and immediately behind the brain spreads out into several pairs of large trunks, which are given to the head, and to the organs of locomotion. The posterior of these trunks form a vascular collar around the oesophagus, beneath which they unite, anteriorly, to a strong bony arch in the middle of the thorax, to form the great arterial trunk, or supra-spinal vessel, which conveys the blood to the posterior part of the body, as in the Myriapoda. This vessel passes beneath the transverse bony arch of the thorax, and is slightly attached to it by fibrous tissue, which circumstance pro- bably induced Professor Muller, who observed this structure in 1828, to regard it as a ligament. In its course backwards, along the ner- Dr. Barry on the Blood Corpuscles. 375 vous cord, this vessel is gradually lessened in size, until it arrives at the terminal ganglion of the cord in the tail, where it is divided into two branches, which take the course of the terminal nerves, and these are again subdivided before they arrive at their ultimate distri- bution. In addition to these parts, the author found a hollow fibrous structure, which closely surrounds the cord and nerves immediately after they have passed beneath the arch of the thorax. From the sides of this structure there pass off backwards two pairs of vessels, that get beneath the peritoneal lining of the abdominal cavity and are distributed on the first pair of branchiae. A small vessel also passes backwards be«eath the cava, and, being joined by anasto- moses from the spinal artery, form the commencement of a vessel which the author formerly described in the * Medical Gazette' as the subspinal vessel. This vessel, extending along the under surface of the nervous cord, communicates directly, by short vessels, with the supra-spinal artery, and gives off, at certain distances from its under surface, several large vessels, which unite with others that convey the blood which has circulated through the abdominal segments, di- rectly to the branchiae, whence it is returned to the heart by many minute vessels that originate from the posterior internal part of each branchia, and, united into single trunks, pass around the sides of the segments to the valvular openings on the dorsal surface of the heart. In the tail of the Scorpion there is a direct vascular communication between the caudal artery and the subspinal vein, which, from the direction of the vessels, induces a belief that there is some peculi- arity in the circulation of the blood in this part of the body. Be- sides these vessels, the author found an arterial trunk that originates from the commencement of the aorta as it descends into the thorax. This vessel passes backwards along the alimentary canal, to which it is distributed, and gives off branches to the liver. This paper is accompanied by five drawings, illustrating the ana- tomical facts which are described in it. May 11. — The following papers were read, viz. — 1. "Variations de la Declinaison et Intensite Horizontale mag- netique observees a, Milan pendant vingt-quatre heures consecu- tives le 22 et 23 Mars, et le 19 et 20 Avril 1843." Par F. Carlini, For. Mem. R.S. 2. " Note regarding the Observations of T. Wharton Jones, Esq., F.R.S., 'On the Blood Corpuscles*.'" By Martin Barrv, M.D., F.R.S. L. & E. The author observes, that the structure of the blood-corpuscles can be accurately learned only by a careful investigation of their mode of origin, and by following them through all their changes in the capillary vessels, and especially in the capillary plexuses and di- latations, where all their stages of transition from the colourless to the red corpuscles may be seen. The filament which forms here and there in the corpuscles of coagulating blood he has shown to other persons, with Microscopes made by Ross and Powell. Dr. Barry denies that he meant certain general remarks in his paper, re- [• See Phil. Mag. S. 3. vol. xxii. p. 480.] 376 Royal Society. ferring to more than twenty delineations of corpuscles from various animals, to apply exclusively to those of man. 3. A paper was also in part read, entitled, " Experiments on the Gas Voltaic Battery, with a view of ascertaining the rationale of its action ; and on its application to Eudiometry." By William Robert Grove, Esq., M.A., F.R.S., Professor of Experimental Philosophy in the London Institution. May 18 — 1. The reading of Prof. Grove's paper, entitled " Expe- riments on the Gas Voltaic Battery, with a view of ascertaining the rationale of its Action," &c, was resumed and concluded. The author, referring to a paper published in the Philosophical Magazine for December 1842 [S. 3. vol. xxi. p. 417], giving an ac- count of a voltaic battery of which the active ingredients are gases, and by which the decomposition of water is effected by means of its composition, describes several variations in the form of the appara- tus recorded in that paper. The experiments he has made with this new apparatus, and the details of which occupy the greater part of the present memoir, he conceives establish the conclusion that the phenomena exhibited in the gaseous battery are in strict conformity with Faraday's law of definite electrolysis. They also confirm him in the opinion which he had expressed in his original paper, and which had been controverted by Dr. Schcenbein, in a communica- tion to the Philosophical Magazine for March 1843 [S. 3. vol. xxii. p. 165], as well as by other philosophers, namely, that the oxygen, in that battery, immediately contributes to the production of the voltaic current. Besides employing as the active agents oxygen and hydrogen gases, he extends his experiments to the following combi- nations : namely, Oxygen and peroxide of nitrogen ; Oxygen and protoxide of nitrogen ; Oxygen and olefiant gas ; Oxygen and carbonic oxide ; Oxygen and chlorine ; Chlorine and dilute sulphuric acid ; Chlorine and solutions of bromine and iodine in alternate tubes ; Chlorine and hydrogen ; Hydrogen and carbonic oxide ; Chlorine and olefiant gas ; Oxygen and binoxide of nitrogen ; Oxygen and nitrogen, with solution of sulphate of ammonia; Carbonic acid and carbonic oxide, with oxalic acid as an electrolyte; Hydrogen, nitrogen, and sulphate of ammonia. The author concludes, on reviewing the whole of this series of ex- periments, that, with the exception, perhaps, of olefiant gas, which appears to give rise to an extremely feeble current, chlorine and oxygen, on the one hand, and hydrogen and carbonic oxide, on the other, are the only gases which are decidedly capable of electro-syn- thetically combining so as to produce a voltaic current. He thinks that the vapours of bromine and of iodine, were they less soluble, would probably also be found efficient as electro-negative gases. Prof. Grove on the Gas Voltaic Battery, 377 He proceeds to consider, in the remaining part of his paper, the application of the gas battery to the purposes of eudiometry, founded on the circumstance already mentioned, that nitrogen gas, as well as several other gases, are absolutely without effect in as far as re- gards any alteration of their volume, and may therefore be ad- vantageously employed in the analysis of atmospheric air, or other mixed gases. Several experiments of this nature are described, and others suggested for future trial. Various theoretical views, arising from this train of inquiry, are then discussed ; particularly with re- ference to the contact theory, with which the author conceives that the action of the gas battery is not reconcileable ; and also to the source of the caloric evolved during voltaic action, which he is strongly inclined to think is in the battery itself. 2. A paper was also read, entitled " Contributions to Terrestrial Magnetism." No. IV. By Lieut.-Colonel Edward Sabine, R.A., F.R.S.* In the present number of these contributions, the author resumes the consideration of Captain Sir Edward Belcher's magnetic obser- vations, of which the first portion, namely, that of the stations on the north-west coast of America and its adjacent islands, was dis- cussed in No. 2. The return to England of H.M.S. Sulphur by the route of the Pacific Ocean, and her detention for some months in the China Seas, have enabled Sir Edward Belcher to add magnetic determinations at thirty-two stations to those at the twenty-nine stations previously recorded. The author first describes the experiments which he instituted with the different needles employed by Captain Sir Edward Belcher for determining the coefficient to be employed in the formula for the temperature corrections; and takes this opportunity of noticing the singular fact that, in needles made of a particular species of Russian steel, this coefficient is negative ; that is, in these needles, an increase of temperature increases the magnetic power. M. Adolphe Erman describes this particular kind of steel as consisting of alternate very thin layers of soft iron and of steel, so that when heated the soft iron layers increase their magnetic intensity and the steel layers diminish theirs. He next considers the more important question of the steadiness with which the needles may have maintained their magnetic condi- tion. By intercomparison of the results obtained at various stations with the different needles employed, he assigns corrections to be applied to the determination of the magnetic force deduced from the observed times of vibration. The magnetic force thus corrected, from the observations with each of the needles employed at the various stations visited by Sir Edward Belcher, is then given in a general table of results. The observations of the inclination of the needle are given in another table ; and a third table contains the [* A notice of No. III. of these Contributions was given in Phil. Mag. S. 3. vol. xx. p. 506; and of No. II. in vol. xviii. p. 549; for No. V. see p. 380.] S78 Royal Society : Dr. Stark on the supposed determination of the declination and inclination of the needle, the horizontal and total magnetic intensity deduced from the observa- tions at thirty-two stations, of which the latitudes and longitudes are given in the same table, together with the dates of observation. May 25. — The following papers were read, viz. — 1. "Meteorological Journal, from January to April inclusive, 1843, kept at Guernsey." By Samuel Elliott Hoskins, M.D. Com- municated by Samuel Hunter Christie, Esq., Sec. R.S. 2. " On the Respiration of the Leaves of Plants." By William Hasledine Pepys, Esq., F.R.S. The author gives an account of a series of experiments on the products of the respiration of plants, and more particularly of the leaves ; selecting, with this view, specimens of plants which had been previously habituated to respire constantly under an inclosure of glass ; and employing, for that purpose, the apparatus which he had formerly used in experimenting on the combustion of the dia- mond*, and consisting of two mercurial gasometers, with the addi- tion of two hemispheres of glass closely joined together at their bases, so as to form an air-tight globular receptacle for the plant subjected to experiment. The general conclusions he deduces from his numerous experi- ments conducted during several years, are, first, that in leaves which are in a state of vigorous health, vegetation is always operating to restore the surrounding atmospheric air to its natural condition, by the absorption of carbonic acid and the disengagement of oxygenous gas : that this action is promoted by the influence of light, but that it continues to be exerted, although more slowly, even in the dark. Secondly, that carbonic acid is never disengaged during the healthy condition of the leaf. Thirdly, that the fluid so abundantly exhaled by plants in their vegetation is pure water, and contains no trace of carbonic acid. Fourthly, that the first portions of carbonic acid gas contained in an artificial atmosphere, are taken up with more avidity by plants than the remaining portions ; as if their appetite for that pabulum had diminished by satiety. 3. A paper was also in part read, entitled " On the minute Struc- ture of the Skeletons or hard parts of the Invertebrata." Part II. By William B. Carpenter, M.D. Communicated by the President. June 1. — The following papers were read, viz. — 1. "Magnetic-term Observations for January, February, March, and April 1 843," made at the Observatory at Prague, by Professor Kreil. Communicated by Samuel Hunter Christie, Esq., Sec. R.S. 2. " Hourly Meteorological Observations, taken between the hours of 6 a.m. March 17th, 1843, and 6 a.m. of the following day, being the period of the Spring Tides of the Vernal Equinox, at Georgetown, British Guiana." By Daniel Blair, Esq., the Colonial Surgeon, transmitted by Henry Light, Esq. Communicated by the Lords Commissioners of the Admiralty. [* The paper in which this apparatus is described was inserted in Phil. Mag. S. 1. vol.xxix. p. 216.] Development of Animal Tissues from Cells. 379 3. " On the minute structure of the Skeletons, or hard parts of Invertebrata." By W. B. Carpenter, M.D. Communicated by the President. Part II. " On the structure of the Shell in the several families and genera of Mollusca *." The author here gives in detail the results of his inquiries into the combinations of the component elements of shell as they are met with in the several families and genera of the Mollusca ; and considers all these results as tending to establish the general propo- sition, that where a recognizable diversity presents itself in the ele- mentary structure of the shell, in different groups, that diversity af- fords characters which indicate the natural affinities of the several genera included in those groups, and which may therefore be em- ployed with advantage in classification, and in the recognition and determination of fossils. June 15. — The following papers were read, viz. — 1. "On the supposed developement of the Animal Tissues from Cells." By James Stark, M.D., F.R.S.E. Communicated by James F. W. Johnston, Esq., M.A., F.R.S. The author controverts the prevailing theory of the developement of animal tissues from cells, and denies the accuracy of the micro- scopical observations on which that theory is founded, as regards the anatomy of the adult as well as of the foetal tissues. He asserts that at no period of foetal life can rows of cells be discovered in the act of transformation into muscular fibres: and he denies that these fibres increase either in length or in thickness by the deposition of new cells. He contends that the ultimate filaments of muscles, as well as all the other tissues of the body, are formed from the fibri- nous portion of the blood, which is itself composed of globules that are disposed to cohere together, either in a linear series, so as to form a net-work of fine filaments, or in aggregated masses of a form more or less globular, composing what have been termed fibrinous corpuscles. These corpuscles have been considered to be the nuclei of cells ; but the author regards them as being merely accidental fragments of broken-down tissues, adhering to the filaments, and noways concerned in their developement. The more regularly dis- posed granules, which are observed to occupy the spaces intervening between the filaments composing the ordinary cellular tissue, he considers as being fatty matter deposited within these spaces. He, in like manner, regards the observations tending to show the cellular origin of the fibrous, cartilaginous, and osseous tissues, as altogether fallacious ; and maintains that the cells, which these animal textures exhibit when viewed under the microscope, are simply spaces occur- ring in the more solid substance of these structures, like the cavities which exist in bread. These views are pursued by the author in discussing the formation of the skin, the blood-vessels, and the nerves, and in controverting the theory of secretion, founded on the action of the interior surfaces of the membranes constituting cells. [* For a notice of Part I. of Dr. Carpenter's paper, see our preceding volume, p. 484.] 380 Royal Society : Lieut.-Col. Sabine on Magnetism. 2. " Contributions to Terrestrial Magnetism." — No. V. By Lieut- Colonel Edward Sabine, R.A., F.R.S.* In this paper the author details and discusses the magnetic obser- vations made on board Her Majesty's ships Erebus and Terror, between October 1840 and April 1841, being the first summer which the expedition under the command of Captain James Clark Ross, R.N., passed within the Antarctic Circle. The elimination of the influence of the ship's iron in the calcula- tion of the results of these observations occupies a considerable por- tion of the paper. Formulae for this purpose are derived from M. Poisson's fundamental equations, and the constants in the formulae are computed for each of the two ships, from observations made on board expressly with that object. With these constants, tables of double entry are formed for each of the three magnetic elements, namely, declination, inclination, and intensity, giving the required corrections of each, for all the localities of the voyage. These and other corrections being applied, the results are tabu- lated and charts formed from them. The full consideration of the charts is postponed until the whole of the materials collected by the Antarctic Expedition shall be before the Royal Society. Meanwhile the paper concludes with the following general remarks, viz. 1. The observations of declination, particularly those which point out the course of the lines of 0 and of 10° east, indicate a more westerly position than the one assigned by M. Gauss in the * Atlas des Erdmagnetismus,' for the spot in which all the lines of declina- tion unite. The progression of the lines in the southern hemisphere generally, from secular change, is from east to west ; the difference consequently is in the direction in which a change should be found in comparing earlier with more recent determinations. 2. The general form of the curves of higher inclination in the southern hemisphere is much more analogous to that in the northern than appears in M. Gauss's maps. For example, the isoclinal line of — 85°, instead of being nearly circular, as represented in the 3te Abtheilung of Plate XVI. of the ' Atlas des Erdmagnetismus,' is an elongated ellipse, much more nearly resembling in form and dimen- sions the ellipse of 85° of inclination in the northern hemisphere in the same work, Plate XVI. 2te Abtheilung. The analogy between the two hemispheres in the characteristic feature of the elliptical form of the higher isoclinal lines is the more important to notice, on account of the particular relation which appears to subsist in the northern hemisphere between the change in the geographical direc- tion of the greater axis of the ellipse, and the secular changes of the inclination generally throughout the hemisphere. The present di- rection of the greater axis in the northern hemisphere, is nearly N.N.W. and S.S.E., or that of a great circle passing through the two foci of maximum intensity. In the southern hemisphere, the present direction of the greater axis differs little from E.S.E. and W.N.W. 3. Captain Ross's observations of the intensity do not appear to [* See ante, p. 377.] Prof. Wheatstone on Voltaic Instruments. 381 indicate the existence anywhere in the southern hemisphere of a higher intensity than would be expressed by 2*1 of the arbitrary scale. In this respect also the analogy between the two hemi- spheres appears to be closer than is shown in M. Gauss's maps, Plate XVIII. With respect to the direction of as much of the line of highest intensity (2*0) as it has been possible to draw with any degree of confidence from the observations now communicated, it will be found to be in almost exact parallelism with the isodynamic line of 1*7 in Plate III. of the author's report " On the Variations of the Magnetic Intensity," in the Report of the eighth meeting of the British Association, for ] 838 ; which line was the highest of which the position could be assigned at that period for any considerable distance by the aid of the then existing determinations. 3. " An Account of several new Instruments and Processes for determining the Constants of a Voltaic Circuit," by Charles Wheat- stone, V.P.R.S., Professor of Experimental Philosophy in King's College, London, Corresponding Member of the Royal Academy of Sciences at Paris, &c. The author proposes in the present communication to give an ac- count of various instruments and processes which he has employed during several years past for the purpose of investigating the laws of electric currents. He states that the practical object for which these instruments were originally constructed, was to ascertain the most advantageous conditions for the production of electric effects through circuits of great extent, in order to determine the practica- bility of communicating signals by means of electric currents to more considerable distances than had hitherto been attempted. Their use, however, is not limited to this special object, but extends equally to all inquiries relating to the laws of electric currents and to every practical application of this wonderful agent. As the instruments and processes described by the author are all founded on Ohm's theory of the voltaic circuit, he commences with a short account of the principal results to which this theory leads, and shows how the clear ideas of electromotive forces and resist- ances, substituted for the vague notions of intensity and quantity which formerly prevailed, furnish us with satisfactory explanations of phenomena, the laws of which have hitherto been involved in ob- scurity and doubt. According to Ohm's system, the force of the current is equal to the sum of the electromotive forces divided by the sum of the resistances in the circuit. The several electromotive forces and resistances which enter into the circuit of a voltaic battery are then defined ; and having frequent occasion to refer to the laws of the distribution of the electric current in the various parts of a circuit, when a branch conductor is placed so as to divert a portion of the current from a limited extent of that circuit, the author directs particular attention to these laws. After recommending several new terms in order to express general propositions, without circum- locution and with greater precision, the author states the method of obtaining the constants of a circuit employed by Fechner, Lenz, Pouillet, &c, and then proceeds to explain the new method he has 882 Boyal Society. himself adopted. The principle of this method is the employment of variable instead of constant resistances, bringing, thereby, the currents in the circuits compared to equality, and inferring from the amount of the resistance measured out between two deviations of the needle, the electromotive forces and resistances of the circuit according to the particular conditions of the experiment ; a method which requires no knowledge of the forces corresponding to differ- ent deviations of the needle. To apply this principle, it is requisite to have a means of varying the interposed resistance, so that it may be gradually changed within any required limits. The author de- scribes two instruments for effecting this purpose ; one intended for circuits in which the resistance is considerable, the other for circuits in which it is small. The Rheostat (for thus the inventor names the instrument under both its forms) may also be usefully employed as a regulator of a voltaic current, in order to maintain for any required length of time precisely the same degree of force, or to change it in any required proportion ; its advantages in regulating electro-mag- netic engines and in the operations of voltatyping, electro-gilding, &c. are pointed out. Various methods of measuring the separate resistances in the cir- cuit, particularly that of the rheomoter itself, are next described ; and it is shown that the number of turns of the rheostat requisite to reduce the needle of a galvanometer from one given degree to another, is an accurate measure of the electromotive force of the circuit. It is then proved that similar voltaic elements of various mag- nitudes, conformably to theory, have the same electromotive force ; that the electromotive force increases exactly in the same propor- tion as the number of similar elements arranged in series ; and that when an apparatus for decomposing water is placed in a circuit, an electromotive force, opposed to that of the battery, is called into action, which is constant in its amount, whatever may be the number of elements of which the battery consists. The electromotive forces of voltaic elements formed of an amalgam of potassium with zinc, copper and platina, a solution of a salt of the negative metal being the interposed liquid, are given ; the last combination is one of great electromotive energy, and when a voltameter is interposed in the circuit, it decomposes abundantly the water contained in it. A still more energetic electromotive force is exhibited by a voltaic element, consisting of amalgam of potassium, sulphuric acid, and peroxide of lead. The author then shows, that if three metals be taken in their electromotive order, the electromotive force of a voltaic combination formed of the two extreme metals is equal to the sum of the electro- motive forces of the two elements formed of the adjacent metals. Among the instruments and processes described in the subsequent part of the memoir are the following. 1. An instrument for mea- suring the resistance of liquids, by which the errors in all previous experiments are eliminated, particularly those resulting from neglect- ing the contrary electromotive force arising from the decomposition of the liquid. 2. The differential resistance measurer, by means of which the resistances of bodies may be measured in the most accu- Dr. A. Farre on the Organ of Hearing in Crustacea. 383 rate manner, however the current employed may vary in its energy. 3. An instrument for ascertaining readily what degree of the gal- vanometric scale corresponds to half the intensity indicated by any other given degree. 4. A means of employing the same delicate galvanometer to measure currents of every degree of energy, and in all kinds of circuits. 5. Processes to determine the deviations of the needle of a galvanometer corresponding to the degrees of force, and the converse. 4. * On the Organ of Hearing in Crustacea." By Arthur Farre, M.D., F.R.S. The author finds that in the Lobster (Astacus marinus), the organ of hearing consists of a transparent and delicate vestibular sac, which is contained in the base, or first joint of the small antennae ; its situa- tion being indicated externally by a slight dilatation of the joint at this part, and also by the presence of a membrane covering an oval aper- ture, which is the fenestra ovalis. The inner surface of the sac gives origin to a number of hollow processes, which are covered with minute hairs and filled with granular matter, apparently nervous. A delicate plexus of nerves, formed by the acoustic nerve, which is a separate branch supplied from the supra-cesophageal ganglion, is distributed over the base of these processes and around the sac. Within the sac there are always found a number of particles of sili- ceous sand, which are admitted, together with a portion of the sur- rounding water, through a valvular orifice at the mouth of the sac, being there placed apparently for the express purpose of regulating the size of the grains. The author considers these siliceous parti- cles as performing the office of otolites, in the same way as the stones taken into the stomachs of granivorous birds supply the office of gastric teeth. Several modifications of this structure exhibited in the organs of hearing of the Astacus fluviatilis, Pagurus streb- lonyx, and Palinurus qvadricomis are next described, and an ex- planation attempted of the uses of the several parts and their sub- serviency to the purposes of that sense. The author concludes by a description of another organ situated at the base of the large antennae, which it appears has been con- founded with the former by some anatomists, but which the author conjectures may possibly constitute an organ of smell. The paper is accompanied by illustrative drawings. 5. " A statement of Experiments showing that Carbon and Ni- trogen are compound bodies, and are made by Plants during their growth." By Robert Rigg, Esq., F.R.S. The author, finding that sprigs of succulent plants, such as mint, placed in a bottle containing perfectly pure water, and having no communication with the atmosphere except through the medium of water, or mercury and water, in a few weeks grow to more than .louble their size, with a proportionate increase of weight of all the chemical elements which enter into their composition, is thence disposed to infer that all plants make carbon and nitrogen ; and that the quantity made by any plant varies with the circumstances in which it is placed. 384 Royal Society. 6. " Physiological inferences derived from Human and Compara- tive Anatomy respecting the Origins of the Nerves, the Cerebellum, and the Striated Bodies." By Joseph Swan, Esq. Communicated by Richard Owen, Esq., F.R.S. The author remarks that those parts of the nervous system which are concerned in motion and in sensation exhibit a great similarity in all vertebrate animals. To the first of these functions belong the anterior and middle portions of the spinal cord and medulla oblon- gata, including the anterior pyramids, the crura cerebri, and some fibres leading to the corpora striata and the convolutions, and also the cerebellum. To the function of sensation belong the posterior surface of the spinal cord, the posterior and lateral portions of the medulla oblongata, including the posterior pyramids, the ventricular cords, and the fourth and third ventricles. From a general comparison of the relative magnitude and struc- ture of these several parts in the different classes of vertebrated animals, the author infers that only a very small portion of the brain is necessary for the origins of the nerves, their respective faculties being generally derived near the place at which they leave the brain. These origins are traced in various cases, where, from peculiarities of arrangement or of destination, they present certain remarkable differences of situation. The author is led to consider the cerebellum as an appendage to the brain, rather than to the medulla oblongata and spinal nerves, for it does not correspond with either the number or the size of the sensitive or motor nerves ; and that it is not required for the intellect, for the special senses, for common sensation, or for volition, appears from its size bearing no proportion to the strength of any of these faculties. Neither is it concerned in digestion or assi- milation, nor does its size present any relation with the heart, the lungs, the muscles, the limbs, the vertebrae, the ribs, or any other organ, not even those of reproduction. As, however, its nervous connexions are principally with those parts which are exclusively subservient to the will, it is probable that it is concerned in the completion, and not in the commencement of the voluntary act. It is probable, also, that the principal crossing of impulses from one side to the other takes place in the medulla oblongata and the motor tracts of the brain. Some of the arrangements of its lobules may have reference to the paces and attitudes of different animals. The will, acting through the cerebral convolutions, sets in action certain muscles placed in proper directions ; but the influence of the cere- bellum is required for giving them steadiness amidst the alterna- tions from one set to another, and- especially when a slight change disturbs the centre of gravity, and until the balance is effectually restored by a subsequent act of the will operating on antagonist or other muscles. The cerebellum also constitutes an additional focus of nervous influence, and may, therefore, cooperate with the brain in increasing the vital powers, and imparting greater energy to the various functions of the body. The author regards the corpus striatum as being a centre for con- Chemical Society. 385 veying to the mind the perception of the motions of the limbs and of their different parts. He concludes with some remarks on the double crossings of the tracts of the centres of the nerves of the arms and legs, and the explanation given by these facts to various pathological phenomena. 7. " Nouveaux faits a ajouter a la Theorie de la Chaleur et a celle de l'Evaporation." Par Daniel Parat, Medecin a Grenoble. Commu- nicated by the President. The author commences by explaining his conception of the nature of heat, of which he gives the following definition : — " Mouvemens centraux obsculaires de la cohesion devenus extemporanement plus rapides, et dilatant de plus en plus tous les corps par une augmenta- tion ainsi acquise de toutes les forces centrifuges." He adopts the theory that the evaporation of water in contact with air is a process identical with chemical solution, and adduces as evidence supporting his views various circumstances which are common both to evapora- tion and to the solution of a salt in water. 8. " On the nature and properties of Iodide of Potassium, and its general applicability to the cure of Chronic Diseases." By James Heygate, M.D., F.R.S. The author has been led by his experience to estimate highly the medicinal properties of the iodide of potassium (which he prefers to the tincture of iodine) in various diseases, and thinks that when it is administered judiciously no deleterious effects are likely to arise from its use. 9. " Observations on the relation which exists between the Respi- ratory Organs of Animals, and the preservation of independent Tem- peratures." By George Macilwain, Esq., Consulting Surgeon to the Finsbury Dispensary. Communicated by W. Lawrence, Esq., F.lt.S. The author expresses his dissent from the prevailing opinion that the temperature maintained by animals above the surrounding me- dium is proportionate to the extent of their respiration ; and adduces many instances among different classes of animals in which he can trace no such correspondence, and others, on the contrary, where increased powers of respiration appear to diminish instead of raising the animal temperature. Hence the author is disposed to regard respiration as a refrigerating rather than a heating process. CHEMICAL SOCIETY. (Continued from p. 77-) April 18, 1843. — The following papers were read : — 78. " On the Spontaneous Change of Fats," by W. Beetz *. 79. " On certain Improvements in the Instrument, invented by the late Dr. Wollaston, for ascertaining the Refracting Indices of Bodies," by John Thomas Cooper, Esq. May 2. — The following communications were read : — * This and all other papers read before the Chemical Society, of which abstracts do not appear in these Proceedings, will be inserted at length in future Numbers of the Philosophical Magazine. Phil. Mag. S. 3. Vol. 23. No. 153. Nov. 1843. 2 C 386 Chemical Society, 80. " Some additional Remarks on Theine," byJ.Stenhouse,Ph.D. 81. "Note on the Preparation of iEther," by George Fownes, Ph.D. The beautiful experiments of Mitscherlich on the indefinite con- version of alcohol into aether by the same quantity of sulphuric acid, seem to point out the possibility of effecting a great improvement in the economical production of that important substance. It is well known that in the old process, in which equal weights of acid and spirit are subjected to distillation, a large quantity of alcohol escapes aetherification at the commencement of the process, owing to the low boiling-point of the mixture, and on the other hand, much is destroyed towards the end of the distillation by the excess- ive heat ; the limits of temperature within which aether is generated in quantity being, as is well known, rather narrow, ranging perhaps between 280° and 320°. In the continuous operation described by Mitscherlich such a mix- ture of alcohol and sulphuric acid is made that its boiling-point shall be well within the aether-producing limit, while into this mixture, maintained in a state of rapid ebullition, alcohol is suffered to flow in such proportion as exactly to replace the liquid which distils over, and which liquid is seen to consist of a mechanical mixture of aether and water with a very small quantity of unaltered alcohol. So long as the temperature is properly maintained by due regulation of the fire and the flow of alcohol, the distilled products do not vary, and the process itself may be, it is said, continued until the oil of vitriol becomes gradually destroyed by the impurities of the spirit, or lost by volatilization. In this experiment absolute alcohol is used ; in the practical manu- facture of aether, however, this is obviously impossible ; it occurred to me therefore to try experimentally how far the process might be carried if ordinary rectified spirit were substituted. It is stated in- deed by Liebig, that under such circumstances aetherification is put a stop to by the accumulation of the water, introduced with the al~ cohol, gradually depressing the boiling-point of the mixture below the temperature at which aether is formed, and that this happens when the whole quantity of spirit used amounts to four times the weight of the oil of vitriol (Annalen der Pharmacie, xxx. 136). It is difficult to see how this could happen if attention were paid to the temperature of the boiling liquid, since it would seem easy to regulate the point of ebullition so as always to maintain the acid of the same degree of concentration with respect to water. A mixture was made of 6 oz. by weight of concentrated sulphuric acid and 3f oz. by weight of rectified spirit of sp. gr. '836 at 60°. This mixture was introduced into a wide-necked flask fitted with a cork pierced with three holes for the purpose of receiving a thermo- meter, a narrow tube connected with a reservoir of alcohol of the same density as that mentioned above, and a wide tube for convey- ing the vapours to the condenser, which was a common metal worm immersed in cold water. These arrangements being completed, an Argand gas-lamp was placed beneath the flask, and the contents made to boil ; the thermometer speedily rose to near 300° F. A slender stream of spirit was now allowed to mix with the boiling Dr. Fownes on the Preparation of JEther. 387 liquid in such quantity as to maintain at once an invariable tem- perature and rapid and violent ebullition. It was soon found that by a little management the thermometer could be kept quite sta- tionary at any required point within the limits before referred to. At 300°, and thence to 360°, the separation of the distilled products into two strata was very distinct and beautiful ; at 280° to 290°, enough alcohol passed over unchanged to prevent this separation until a little water had been added. There was a slight trace of sulphurous acid, and the mixture in the flask gradually deepened in colour, until at last it became nearly black, without however in the slightest degree losing its efficiency. At this period the process had been kept up about fifteen hours ; more than a gallon of alcohol — twenty times the weight of the acid — had passed through the apparatus, and as the activity of the opera- tion remained to the last unimpaired, it seems fair to infer that its only limits are the loss of sulphuric acid by volatilization, and the formation, in small quantities, of secondary products, such as oil of wine, sulphurous acid, and defiant gas. The sether obtained was mixed with some caustic potash and rec- tified by the heat of warm water; its sp. gr. at 60° was *730, and it measured fully three pints. As merely water at 55° was used for condensation in place of ice, much loss of vapour must have oc- curred ; and since the residual alkaline liquid yielded a large quan- tity of alcohol by distillation, the process must be considered on the whole a tolerably productive one, although still very far from what might be desired. Of course, on a large scale much of this loss would be avoided. It was remarked that during the whole of the operation, even when the temperature was purposely kept so low as to allow much alcohol to escape decomposition, a considerable quantity of perma- nent gas made its appearance. By adapting to the lower end of the worm of the condenser a two-necked receiver furnished with a bent tube dipping under water, it was easy to collect and examine this gaseous matter. When purified from aether-vapour by washing with oil of vitriol, it was inflammable, burned with much light, and pos- sessed the peculiar alliaceous odour characteristic of purified defiant gas. Its production became much increased by a rise of tempera- ture ; at 310° it passed in a rapid succession of large bubbles. There appears no difficulty then in applying Mitscherlich's con- tinuous process to the economical manufacture of sether on the great scale ; it is very probable too, that by avoiding the use of a naked fire much of the secondary action to which allusion has been made might be prevented, while by a proper condensing arrangement the waste obvious in my own experiments would be avoided. The most advantageous temperature could be determined by experience in a very short time, and with this knowledge the process might be con- ducted ever afterwards in such a manner as to yield a perfectly uni- form product. A somewhat low temperature, about 280° to 290°, might possibly be the most advantageous, since it would be better to let a little alcohol escape setherification, than to use heat enough 2C2 388 Intelligence and Miscellaneous Articles. 'o to occasion the abundant production of oil of wine and olefiant gas. This alcohol is easily recovered after the rectification of the aether. It may be proper to mention also that the mixture in the distillatory vessel may be repeatedly suffered to cool, and again reheated with- out injury. May 16. The following papers were then read : — " On the Heat of Chlorine, Bromine and Iodine, developed during the formation of the Metallic Compounds," by Thomas Andrews, M.D., from the Author. 82. "On Ferric Acid," by J. Denham Smith, Esq. 83. " On the Action of Alkalies on Wax," by R. Warington and Wm. Francis, Esqrs. 84. " On the Action of Sulphuric Acid on the Ferrocyanide of Po- tassium," by George Fownes, Ph.D. XLVIII. Intelligence and Miscellaneous Articles. ON A CHANGE PRODUCED BY EXPOSURE TO THE BEAMS OF THE SUN, IN THE PROPERTIES OF AN ELEMENTARY SUB- STANCE. BY PROF. DRAPER, OF NEW YORK. AT the recent meeting at Cork of the British Association, a paper by Prof. Draper was read by Dr. Kane before Section A., Ma- thematical and Physical Science, of which the following is an ab- stract : — Prof. Draper's paper commenced with announcing that chlorine gas which has been exposed to the daylight or to sunshine possesses qualities which are not possessed by chlorine made and kept in the dark. It acquires from that exposure the property of speedily uniting with hydrogen gas. This new property of the chlorine arises from its having absorbed tithonic rays, corresponding in refrangibility to the indigo. The property thus acquired is not transient, like heat, but permanent. A certain portion of the tithonic rays is absorbed and becomes latent before any visible effect ensues. Light, in pro- ducing a chemical effect, undergoes a change as well as the sub- stance on which it acts ; it becomes detithonized. The chemical force of the indigo ray is to that of the red as 66' 6 to 1. The author remarked, that we are still imperfectly acquainted with the constitution of elementary bodies, inasmuch as we know in general only those properties which they possess after having been subjected to the influence of light. ACCOUNT OF CLEGG'S DIFFERENTIAL DRY GAS-LIGHT METER. BY PROFESSOR VIGNOLES, C.E. To those familiar with gas operations in general, there is no oc- casion to enlarge on the advantages of a good dry meter. It has been a desideratum ever since the use of a meter at all was first duly appreciated, and has often attracted the attention of many scientific and practical men, who have attempted to realize this desirable object. This will doubtless be deemed quite a sufficient justification for Intelligence and Miscellaneous Articles. 389 so experienced an engineer as Mr. Clegg to present himself before the public as the inventor of an instrument which he considers likely to realize what appears to be so much required. The construction and action of this meter are based upon the established facts, that the heat and light from the various kinds of carburetted hydrogen gas are strictly proportionate to each other ; and, by the application of that fact, in combination with an apparatus, act- ing on the same principle as the differential thermometer of Leslie. By this apparatus will be measured most delicately the smallest differences of heat, and consequently the consumption of gas will be registered in proportion to its illuminating power. Let two hollow glass cylinders, each about one inch in diameter and three inches long, be connected together in the centre of their lengths by a hollow bent tube of the same material (being such as will be afterwards described when treating of the mechanical ar- rangements for a six-light meter, and delineated in the accompanying figures). Let these cylinders and the connecting tube be perfectly exhausted of air, and let as much alcohol be introduced as will nearly fill one cylinder, leaving a vacuum in the other — or at least leaving it without air, and with only such vapour therein as may arise from the alcohol. Now as pure alcohol boils, in vacuo, at 56° of Fahren- heit's thermometer, the smallest excess of heat above this tempera- ture applied to the cylinder having the alcohol therein will cause the liquid to evaporate, and, by its consequent elasticity, will drive the spirit below the vapour into the colder cylinder ; and the velocity with which the alcohol will be driven out from one cylinder to the other will be in exact proportion to the quantity of heat applied, twice or three times the cause producing twice or three times the effect, and so on. For, let air or gas be heated to a uniform temperature (say to 150° of Fahrenheit), and, when so heated, let it be directed to impinge upon one of two glass cylinders (such as those above de- scribed) with any given velocity ; if this velocity be doubled, then double the quantity (or volume or body) of heat will be passed, and consequently double the effect (that is double the velocity with which the alcohol is driven) must be produced, such being an unerring and natural law. Although twice the effect be thus produced, the tem- perature of the air or gas has not been increased ; it is only the flow or quantity which has been augmented ; and this must be what is to be understood by quantity of heat. The best criterion of the sound- ness of the above statement is, that these facts have been determined from, and are founded upon, repeated and concurring experiments — the only true source of philosophical induction. Such, then, being established, it became a leading principle ; and the next step was to ascertain, by further experiments, how to apply this scientific fact to the art of measuring the quantity of heat applied to one of the above-described glass cylinders,and of registering the same ; for this being accomplished, there was at once obtained an apparatus, whereby may be determined the exact flow of air or gas in a given time ; in other words, a gas-light meter, such as the present instrument. The first consideration therefore was, how to heat a given quantity of gas to a certain uniform temperature, for the gas 390 Intelligence and Miscellaneous Articles. being thus heated, and allowed to flow out at a given velocity, a uniform flow of heat was obtained. Now, for the purposes of measuring this flow of heat, in the in- stance of a gas-meter, the source of heat is present by the inflam- mable gas itself ; and, after numerous experiments, it was fully and conclusively ascertained that a jet of gas, issuing out of an orifice, perforated in the side of a small solid brass cylinder (such as will be afterwards described, and shown in the annexed figures), will heat the said cylinder to a uniform given temperature, whatever be the height of the said jet : for, with a small flame, the jet clings, as it were, and is in immediate contact with the solid cylinder ; whereas, when the flame issues from the orifice with considerable velocity, still the longer jet only imparts the same degree of heat to the solid cylinder as did the smaller one ; the'increased (or lengthened) flame being, in this latter case, driven away from any closer contact by its own ve- locity, or rather by the velocity due to the pressure of the gas issuing from the orifice. This fact having been thoroughly established by repeated experiments and practice, the necessary apparatus of the gas- meter, for the practical application of the fact, became very simple. The next point expedient to be determined accurately, was the proper superficies of a receptacle, to be heated by or from such a solid cylinder as the one just described ; which surface would be sufficient to communicate the requisite heat to such portion of the whole quan- tity of gas to be measured, as it was necessary to pass through the receptacle, without altering the temperature thereof in any percep- tible degree. This point was ascertained, as the preceding ones were, by repeated experiments ; and, further, it was found advisable that the receptacle for heating the gas should be well clothed with the best non-conducting substance, to keep it at a proper tempera- ture. The proportionate surface of the receptacle having been de- termined, certain other proportions and dimensions were established, which, as applicable to a six-light meter, are given in the figures accompanying the subsequent mechanical description. Lastly, it remained to be found what quantity of gas, heated in the manner previously described, and discharged upon one of two such glass cylinders as before mentioned, would be sufficient to expel the alcohol therefrom, and drive it into the other cylinder. Numerous ex- periments and long practice have determined this quantity to be no more than about one- seventh part of the whole gas requisite to supply the number of burners, the consumption whereof is to be measured. This being conclusively established, led to the consequent arrange- ment of dividing the flow of gas as applied from the main, so as to pass them separately through two openings, one of which should have its area six times that of the other, whereby six-sevenths of the gas admitted from the main might flow towards the burners without passing through the working part of the meter, leaving the remaining, or one seventh, part to perform the necessary functions of registering the amount of the whole quantity. The simple manner in which this arrangement is carried into effect, is duly pointed out by the figures, and is described in the subsequent explanation of the whole of the mechanical contrivances for the proper working of the meter. Intelligence and Miscellaneous Articles. 391 Two openings, exposed to the stream of the same volume of air or gas, however they may differ in their respective areas, will always admit quantities thereof strictly proportionate to those areas. Thus, through a circular aperture of one inch in diameter, will pass precisely sixty- four times as much air or gas as through a circular aperture of only one-eighth of an inch in diameter ; and this will hold unerringly, and under all pressures, allowing only for the additional friction the gas is exposed to in passing through the "smaller opening, compared to its friction through the larger one. This theory is so well authen- ticated by practice, that it can require no further illustration here. It is only the smaller quantity, therefore, or one-seventh part, of the gas which it is necessary actually to pass through the working and registering parts of the meter ; and from this portion being very dry and at a high temperature, an immense advantage is derived ; for, as the decomposing action on the materials of the meter ceases when the gas is hot and dry, there will be little or none of that wear and tear, going on so rapidly in the ordinary water meter, from the am- monia, sulphur and galvanic action, which are the principal agents of deterioration, and which also act (though not to the same extent) upon other dry meters, only exposed to the usual aqueous vapour which gas absorbs at the ordinary temperature of the atmosphere. In hot dry gas the galvanic action ceases ; the ammonia, which exists in the form of a gas, will, when not exposed to aqueous vapour, pass off harmless ; but where there is moisture present, the ammoniacal gas is instantly absorbed, and becomes a strong alkaline solution, acting on the wrought iron parts of the meter. From Sir H. Davy's early experiments, it appears that (taking weight) 100 grains of water absorbs thirty-four grains of ammoniacal gas, consequently (taking bulk) one cubic inch of water takes up 475 cubic inches of that gas. [See Henry's Chemistry, vol. i. p. 397, third edition.) The sulphur in the gas, combining with hydrogen, forms sulphuretted hydrogen gas. Water absorbs twice its own bulk of this gas (see the same Avork] , and when so impregnated, the gas is very destructive to brass and copper ; but, when dry, it is harmless. It will be observed that, in the dry meter now describing, all those parts which are exposed to six -sevenths of the whole quantity of gas admitted, consist either of cast iron, pure tin, or German silver, none of which materials are acted on injuriously by gas in the usual state of the atmosphere ; and as there is no water, and the remaining (only one-seventh) part of the gas working through the meter at a high temperature, the action of decomposition on the materials is altogether avoided. All these requisites having been most conclusively determined production of iodoform by the mutual reaction of iodine upon al- cohol, under the influence of potash ; acetic aether only is formed. If, on the other hand, to an aqueous solution of carbonate of potash there be added alcohol, iodide of potassium, and iodine in excess (the alcohol not being sufficient to separate the saline solution), and the mixture be exposed to a temperature of 140° Fahr., there is an abun- dant production of iodoform in a few hours, iodine in excess always remaining. M. Bouchardat observes, that it was long before he could account for the difference of action under circumstances which appeared so similar, for while with caustic potash acetic aether only was obtained, whereas with the carbonate the product was iodoform ; it afterwards appeared that as it was requisite to employ a temperature of 140° with the carbonate of potash, whilst with the caustic potash it was only about 60° to 68° Fahr., this difference might account for the dif- ferent effects produced. To determine this a solution of iodine and iodide of potassium in water and alcohol was heated to 140° Fahr., and a solution of caustic potash was then added, in which the forma- tion of iodoform immediately took place ; it is therefore evident that the different reactions were occasioned by variations of temperature. —Journal de Pharmacie et de Chimie, JuUlet, 1843. METEOROLOGICAL OBSERVATIONS FOR SEPT. 1843. Chisurick. — Sept. 1. Foggy: sultry. 2,3. Slight haze : sultry. 4. Clear and fine. 5. Heavy dew : clear. 6. Cloudless. 7. Slight haze : cloudless and hot. 8, 9. Very fine. 10. Foggy : heavy thunder-showers. 11. Very fine. 12. Over- cast. IS. Clear and fine. 14. Overcast. 15 — 20. Exceedingly fine. 21. Foggy : very fine. 22, 23. Clear and fine. 24, 25. Overcast. 26. Fine: clear and cool. 27. Cloudy and cool : clear, with slight frost at night. 28. Very clear : over- cast. 29. Cold and dry : overcast. 30. Rain. — Mean temperature of the month 3°*81 above the average. Boston. — Sept. 1 — 6. Fine. 7. Fine: quarter-past 2 p.m. heat 77°. 8. Foggy. 9. Cloudy. 10. Fine: rain p.m. 11, 12. Cloudy. 13— 15. Fine. 16. Cloudy. 17 — 19. Fine. 20. Cloudy : rain early a.m. 21,22. Fine. 23,24. Foggy. 25. Cloudy : rain a.m. 26. Windy. 27. Cloudy. 28. Windy. 29. Cloudy. 30. Cloudy : rain early a.m. Sandwich Manse, Orkney. — Sept. 1. Clear. 2. Cloudy : showers. 3. Showers. 4. Showers: cloudy. 5. Damp : drizzle. 6. Damp: fine. 7—9. Clear: hot: fine. 10. Damp. 11. Haze : fog. 12. Fine. 13. Haze: clear. 14. Clear. 15. Clear: cloudy. 16. Clear. 17. Cloudy: fine : damp. 18. Showers. 19. Clear : aurora. 20. Rain. 21. Showers : cloudy. 22. Cloudy. 23. Damp i drizzle. 24. Drizzle. 25. Showers : drizzle. 26. Bright : cloudy : aurora. 27. Showers. 28. Showers i cloudy. 29. Rain. 30. Cloudy : rain. Ajijtlegarth Manse, Dumfries-shire. — Sept. 1. Fair and fine: one slight shower. 2. Fair and fine. 3. Showery. 4, 5. Fine harvest-day. 6. Fine harvest-day : one slight shower. 7. Fine harvest-day : fair. 8, 9. Fine harvest-days. 10. Fine harvest-day, but cloudy. 11. Fine : shower early a.m. ;12, 13. Fine har- vest-days. 14. Fine harvest-day : thunder. 15. Fine harvest-day. 16. Fine harvest-day: sheet lightning. i7. Showery. 18. Fair and fine : thunder. 19. Fair and fine. 20 — 24. Fine harvest-day. 25. Fine harvest-days : hoar-frost. 26. Fine harvest-day ! no frost. 27. Fine harvest-day : hoar-frost. 28. Dull : wet evening. 29. Cloudy : rain. 30. Cloudy. Sun shone out 28 days. Rain fell 7 days. Thunder 2 days. Hoar-frost 2 days. Calm 1 4 days. Moderate 9 days. Brisk 4 days. Strong breeze 3 days. Mean temperature of the month 56°*3 I* a. a o ~ u «- • •Stf a • •> 9 X <-» o S, H eg en ^B O 3= g o _ o Sir0 ») o ,« « k. ~ ^ ? -** -J 2 s « en j> S ^ 2 ^ §o c S « ,$«» "9 9 », ■6 g . B oj 5 ^ "B to « B CO B •id* 9 as uiH x«M Kg •UTB6 uubj -*"S *s •UI-B?8 •UOJSOtf •UIB6 •oos -Xoh : uopuo'i JO sXbq SJ2,'S.2<2 •>,? .93 .5 S3 .'S n B on-ff «N«oaoiNiMOiMna CO«3!0«iOOtOtOU • S I I*' B- B I 6 | § || g «• cJ «• | | B g cj « C- = -' = k % * | .~ ..- i* '". iC i . .J OlTt< -* co to <-» •-* IfiffiMifi^CM1?] OlN^fl O CO 'O X O O 'f '^'tOPO t^.WtO Tf K11 ifl O "" ■f CO OiO ^h 00 ■^«Tj',<3'»fl*OiO"5',J'1 }-<*T*o-*ftt'fch>.oooot>»t>*r>.i>.t>. »>.«o ncococokcon t>.« «o«coc^M«o««o«M'^>.^^to^^ot>.M^®pw«tp©coTt^« OPOP **S ic?OtOtO(0000»rttOtOmtOtOiO*Omirt»ra»0',T^r^',5,,T onoN^ocotonoooinNwpNpTfCc^tpNi'NNopNo « co r^ 00 co 60 « Tn co 4t< co b: w o> ^ co to 60 -^f ^f c*s ^ og Jg ,ij .'b **> IC ^ *> Wb>.t^l>i.^CtO KKNKNtO t^tO^l^l^t^Wt^Wt^tOt0tOtO»0 »0 rt W 55* to ©ib io«ttb2tototo'Otototctototototototo • ^tOOWO^COOHiflOWtO CO^ WOiOlO-f-COIMiMCOOFH MQOMnoQmia- Ot~>CTi©©© 0©©0!©©©©C7iC?)0)C7l©Ol^--'^1 ^»n«5to©»-ioiocN©©'--'to©cocoto©©r^'-'t>*'-t,'--'t>^-'-«©©'i'"i,OOt^COCO©CMtO©COtOtO(N©COCO»OiO N(N^nWWW«OCOHC10Cp»aOHiHCftlN^^«NOlKa)N^ ©©©©©0©©©0^©©©OiOlOi©©©Ol©©©©©OlC7)Oib;Oi COCOCOCOC0C0COC0COC^C0C0COC>»CNC^C0C0C0CNCOC0COCOeO«CNWCNN Ol^J" O^-^C0. )CNWCNCOCNC0C0COCOC0C0e0C0CNCNINi )O^"^C0Cj©»0tCC0 SIS © ( to -r t )-*^t©^'tCO©CNtOC WCNCNCNCTCNWCNCNNCMCNC^CNCICNC^WC^C^C^CNCOCNCNCNC C0t>»©tOCN i—tOe0tO:OCNC0<-'COtO-1'CN©C0Tf —t CO © t^.— t^*'-' mi^.00 1 HOiC ^ ift 1" OIC OlTj-COCOtOtO-ftOTCOCOCOGO tNC0C0C0C0C0C0C0C0CNWC0CNCNCNC^C0C0C0C0C0C0C0C0C0CNCN(NCNC^ TfC0'fl,©C0CN©t^.C0CNO©C0 t^'O CO X 00 CO t>t©tO OirN.OJTf»^H-»f00C0 CO CO CO CO X OH -wtO COCNl^©COT^^CNTftO© — f O© K5 0 CO «!0 C7J WCOCNCOeOtNCNCNT'ppCN^COC^©^-!^-'^-" — «^0^«©l^C»OlCO 0©©©©©©©©0©©©O^COJ©©©©©©©©©©©010". Ol CI COC0COCOC0C0C0COi?3C0COC0COWMCOC0C0COC0C0COC0COCOCOC^C>lC^C,< C0C0-rjrtOCNC0-^'TfT»<< i^ cn r» iO t^to >o >o ■* 5. . . C07*"C0C0'Tj«C0COCOCN©C ©b©cbbbbbbbboQi)6666b6666bbc?ic )C0C0CO«COCOCOC0C0C0WC0WCNC0COC0COCOCOCOC0WC0COWCNCOCN ^ WW*W©NCOOJO^Wnil»fl©KCCO>©'-" ©"CNC0^t»OtOl^.C0Oi© CNCN0NCNM©iCN©lCNCNCO THE LONDON, EDINBURGH and DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF SCIENCE. [THIRD SERIES.] DECEMBER 1843. XLIX. Description of the Tithonometer, an instrument for measuring the Chemical Force of the Indigo- tithonic Hays. By John W. Draper, M.D., Professor of Chemistry in the University of New York*. T HAVE invented an instrument for measuring the chemical force of the tithonic rays which are found at a maximum in the indigo space, and which from that point gradually fade away to each end of the spectrum. The sensitiveness, speed of action and exactitude of this instrument, will bring it to rank as a means of physical research with the thermo-multiplier of M. Melloni. The means which have hitherto been found available in op- tics for measuring intensities of light, by a relative illumination of spaces or contrast of shadows, are admitted to be inexact. The great desideratum in that science is a photometer which can mark down effects by movements over a graduated scale. With those optical contrivances may be classed the methods hitherto adopted for determining the force of the tithonic rays by stains on Daguerrotype plates or the darkening of sensitive papers. As deductions, drawn in this way, depend on the opinion of the observer, they can never be perfectly satisfac- tory, nor bear any comparison with thermometric results. Impressed with the importance of possessing for the study of the properties of the tithonic rays some means of accurate measurement, I have resorted in vain to many contrivances ; and, after much labour, have obtained at last the instrument which it is the object of this paper to describe. The tithonometer consists essentially of a mixture of equal measures of chlorine and hydrogen gases, evolved from and confined by a fluid which absorbs neither. This mixture is kept in a graduated tube, so arranged that the gaseous surface * Communicated by the Author. Phil. Mag. S. 3. Vol. 23. No. 154. Dec. 1843. 2 D 402 Professor Draper's Description of the Titlwnometer. exposed to the rays never varies in extent, notwithstanding the contraction which may be going on in its volume, and the muriatic acid resulting from its union is removed by rapid absorption. The theoretical conditions of the instrument are therefore sufficiently simple; but, when we come to put them into prac- tice, obstacles which appear at first sight insurmountable are met with. The means of obtaining chlorine are all trouble- some; no liquid is known which will perfectly confine it; it is a matter of great difficulty to mix it in the true proportion with hydrogen, and have no excess of either. Nor is it at all an easy affair to obtain pure hydrogen speedily, and both these gases diffuse with rapidity through water into air. Without dwelling further on the long catalogue of difficul- ties which is thus to be encountered, I shall first give an ac- count of the capabilities of the instrument in the form now described, which will show to what an extent all those diffi- culties are already overcome. In a course of experiments on the union of chlorine and hydrogen, some of which were read at the last meeting of the British Association, I found that the sensitiveness of that mixture had been greatly underrated. The statement made in the books of chemistry, that artificial light will not affect it, is wholly erroneous. The feeblest gleams of a taper produce a change. No further proof of this is required than the tables given in this communication, in which the radiant source was an oil-lamp. For speed of ac- tion no tithonographic compound can approach it; a light, which perhaps does not endure the millionth part of a second, affects it energetically, as will be hereafter shown. Proqfsqf the sensitiveness of the Tithonometer.-*— Thefollowing illustrations will show that the tithonometer is promptly affected by rays of the feeblest intensity, and of the briefest duration. When, on the sentient tube of the tithonometer, the image of a lamp formed by a convex lens is caused to fall, the liquid instantly begins to move over the scale, and continues its mo- tion as long as the exposure is continued. It does not answer to expose the tube to the direct emanations of the lamp with- out first absorbing the radiant heat, or the calorific effect will mask the true result. By the interposition of a lens this heat is absorbed, and the tithonic rays alone act. If a tithonometer is exposed to daylight coming through a window, and the hand or a shade of any kind is passed in front of it, its movement is in an instant arrested; nor can the shade be passed so rapidly that the instrument will fail to give the proper indication. Professor Draper's Description of the Tiihonometer. 403 The experimenter may further assure himself of the ex- treme sensitiveness of this mixture by placing the instrument before a window, and endeavouring to remove and replace its screen so quickly that it shall fail to give any indication ; he will find that it cannot be done. Charge a Leyden phial, and place the tithonometer at a little distance from it, keeping the eye steadily fixed on the scale ; discharge the jar, and the rays from the spark will be seen to exert a very powerful effect, the movement taking place and ceasing in an instant. This remarkable experiment not only serves to prove the sensitiveness of the tithonometer, but also brings before us new views of the powers of that extraordinary agent electri- city. That energetic chemical effects can thus be produced at a distance by an electric spark in its momentary passage, effects which are of a totally different kind from the common manifestations of electricity, is thus proved; these phaenomena being distinct from those of induction or molecular movements taking place in the line of discharge, they are of a radiant character, and due to the emission of tithonicity ; and we are led at once to infer that the well-known changes brought about by passing an electric spark through gaseous mixtures, as when oxygen and hydrogen are combined into water, or chlorine and hydrogen into muriatic acid, arise from a very different cause than those condensations and percussions by which they are often explained, a cause far more purely che- mical in its kind. If chlorine and hydrogen can be made to unite silently by an electric spark passing outside the vessel which contains them, at a distance of several inches, there is no difficulty in understanding why a similar effect should take place with a violent explosion when the discharge is made through their midst ; nor how a great many mixtures may be made to unite under the same treatment. A flash of lightning cannot take place, nor an electric spark be dis- charged, without chemical charges being brought about by the radiant matter emitted. Proofs of the exactness of the indications of the Tithonometer. — The foregoing examples may serve to illustrate the extreme sensitiveness of the tithonometer ; I shall next furnish proofs that its indications are exactly proportional to the quantities of light incident on it. As it is necessary, owing to the variable force of daylight, to resort to artificial means of illumination, it will be found advantageous to employ the following method of obtaining a flame of suitable intensity. 2 D 2 404 Professor Draper's Description of the Tithonometer. Let A B, fig. 4, be an Argand oil lamp of which the wick is C. Over the wick, at a distance of half an inch or there- abouts, place a plate of thin sheet copper, three inches in diameter, perforated in its centre with a circular hole of the same diameter as the wick, and concentric therewith. This piece of copper is represented at dd; it should have some contrivance for raising or depressing it through a small space, the proper height being determined by trial. On this plate, the glass cylinder e, an inch and three-quarters in diameter and eight or ten inches long, rests. When the lamp is lighted, provided the distance between the plate dd and the top of the wick is properly adjusted, on putting on the glass cylinder the flame instantly assumes an intense whiteness ; by raising the wick it may be elongated to six inches or more, and becomes exceedingly brilliant. Lamps constructed on these principles may be purchased in the shops. I have, however, contented myself with using a common Ar- gand study-lamp, supporting the perforated plate d d at a proper altitude by a retort stand. It will be easily understood that the great increase of light arises from the circumstance that the flame is drawn violently through the aperture in the plate by the current established in the cylinder. As much radiant heat is emitted by this flame, in order to diminish its action, and also to increase the tithonic effect, I adopt the following arrangement. Let A B, fig. 4, be the lamp ; the rays emitted by it are received on a convex lens D, four inches and three-quarters in diameter, that which I use being the large lens of a lucernal microscope. This, placed at a distance of twenty-one inches from the lamp, gives an image of the flame at a distance of thirteen inches, which is received on the sentient tube of the tithonometer F; between the tithonometer and the lens there is a screen E. Things being thus arranged, and the lamp lighted so as to give a flame about three inches and a half long, the experi- ments may be proceeded with. It is convenient always to work with the flame at a constant height, which may be de- termined by a mark on the glass cylinder. At a given in- stant, by a seconds watch, the screen E is removed, and im- mediately the tithonometer begins to descend. When the first minute is elapsed the position on the scale is read off' and registered ; at the close of the second minute the same is done, and so on with the third, &c. And now, if those numbers be compared, casting aside the first, they will be found equal to one another, as the following table of experiments, made at different times and with different instruments, shows : — Professor Draper's Description of the Tithonometer. 405 Table I. Showing that when the radiant source is constant, the amount of movement in the tithonometer is directly proportional to the times of exposure. Time. Experiments. 1. 2. 3. 4. 5. ii 30 7-00 7-00 10-25 5-25 60 800 7-75 11-50 11-75 6-50 90 7-50 8-00 11-50 ... 6-25 120 775 775 11-50 1300 600 150 775 7'25 ... 600 180 ... ... ... 1200 600 210 ... ••• ... ... 600 Mean 7-60 7-55 11-19 12-25 6-00 From this it will be perceived that, taking the first experi- ment as an example, if at the end of 30 seconds the tithono- meter has moved 7*00, at the end of 60" it has moved 8*00 more, at the end of 90", 7'50 more, at the end of 120", 7*75 more; the numbers set down in the vertical column repre- senting the amount of motion for each thirty seconds. And, when it is recollected that the readings are all made with the instrument in motion, the differences between the numbers do not greatly exceed the possible errors of observation. It may be remarked that the third and fourth experiments were made with a different lamp. Though a certain amount of radiant heat from a source so highly incandescent as that here used will pass the lens, its effects can never be mistaken for those of the tithonic rays. This is easily understood when we remember that the effect of such transmitted heat would be to expand the gaseous mixture, but the tithonic effect is to contract it. Next, I shall proceed to show that the indications of the tithonometer are strictly proportional to the quantity of rays that have impinged upon it ; a double quantity producing a double effect, a triple quantity a threefold effect, &c. A slight modification in the arrangement (fig. 4) enables us to prove this in a satisfactory way. The lens D, being mounted in a square wooden frame, can easily be converted into an in- strument for delivering at its focal point, where the sentient tube is placed, measured quantities of the tithonic rays, and thus becomes an invaluable auxiliary in those researches which require known and predetermined quantities of tithonicity to 406 Professor Draper's Description of the Tithonometer. be measured out. The principle of the modification is easily apprehended. If half the surface of the lens be screened by an opake body, as a piece of blackened cardboard, of course only half the quantity of rays will pass which would have passed had the screen not been interposed. If one-fourth of the lens be left uncovered, only one-fourth of the quantity will pass; but in all these instances the focal image remains the same as before. By adjusting, therefore, upon the wooden frame of the lens, two screens the edges of which pass through its centre, and are capable of rotation upon that centre, we shall cut off all light when the screens are applied edge to edge, we shall have 90° when they are rotated so as to be at right angles, and 180° when they are superposed with their edges parallel. Thus by setting them in different angular positions, we can gain all quantities from 0° up to 180°, and by removing them entirely away reach 360°. It will be understood that the effect of the instrument is to give an image of a visible object of which the intensity can be made to vary at pleasure in a known proportion. In order therefore to prove that the indications of the titho- nometer are proportional to the quantity of impinging rays, place this measuring lens in the position D, setting its screens at an angle of 90°. Remove the screen E, and determine the effect on the tithonometer for one minute. At the close of the minute, and without loss of time, turn one of the screens so as to give an angle of 180°, and now the effect will be found double what it was before, as in the following table : — Table II. Showing that the indications of the tithonometer are ■propor- tional to the quantity of incident rays. Quantities. Experiment 1. Experiment 2. Observed. Calculated. Observed. Calculated. 90° 180 270 360 2-18 4-27 6-70 8-90 2*22 4-45 6-67 8-90 2-69 5-75 8-25 11-00 2-75 5-50 8-25 1100 I have stated in the commencement of this paper, that the action upon the tithonometer is limited to a ray which corre- sponds in refrangibility to the indigo, or rather, that in the indigo space its maximum action is found. The following table serves at once to prove this fact, and also to illustrate the chemical force of the different regions of the spectrum : — Professor Draper's Description of the Tithonometer. 407 Table III. Showing that the maximum for the tithonometer is in the indigo space of the spectrum. Space. Ray. Force. Space. Ray. Force. 0 1 2 3 4 5 6 7 Extreme red Yellow Green-blue Blue •33 •50 •75 2-75 1000 5400 108-00 14400 8 9 10 11 12 13 14 Blue-indigo... Violet 204-00 240-00 121-00 72-00 48-00 24-00 1200 Extra-spectral In this table the spaces are equal ; the centre of the red, as insulated by cobalt blue glass, is marked as unity; the centre of the yellow, insulated by the same, being marked 3 ; the in- tervening region being divided into two equal spaces, and di- visions of the same value carried on to each end of the spec- trum. As instruments will no doubt be hereafter invented for measuring the phaenomena of different classes of rays, it may prove convenient to designate the precise ray to which they apply. Perhaps the most simple mode is to affix the name of the ray itself. Under that nomenclature the instrument de- scribed in this paper would take the name of Indigo-tithono- meter. There is no difficulty in adapting this instrument to the determination of questions relating to absorption, reflexion and transmission. Thus I found that a piece of colourless French plate-glass transmitted 866 rays out of 1000. Description of the Instrument. First, of the glass part.— The tithonometer consists of a glass tube bent into the form of a siphon, in which chlorine and hydrogen can be evolved from muriatic acid, containing chlorine in solution, by the agency of a voltaic current. It is represented by fig. 1, where a b c is a clear and thin tube four-tenths of an inch external diameter, closed at the end a. At d a circular piece of metal, an inch in diameter, which may be called the stage, is fastened on the tube, the distance from d to a being 2*9 inches. At the point .r, which is two inches and a quarter from d, two platina wires, x and y, are fused into the glass, and entering into the interior of the tube, are destined to furnish the sup- ply of chlorine and hydrogen ; from the stage d to the point b, the inner bend of the tube, is 2*6 inches, and from that 408 Professor Draper's Description of the Tithonometer. B A V 1 1> F AP 11 Fig. 4. Fig. 1. A Fig. 2. 7$e Tithonometer. Professor Draper's Description of the Tithonometer. 409 point to the top of the siphon c, the distance is three inches and a half. Through the glass at z, three quarters of an inch from c, a third platina wire is passed ; this wire termi- nates in the little mercury cup r, and x and y in the cups p and q respectively. . Things being thus arranged, the instrument is filled with its fluid prepared, as will presently be described ; and as the legs ab,b c are not parallel to each other, but include an an- gle of a few degrees, in the same way that Ure's eudiometer is arranged, there is no difficulty in transferring the liquid to the sealed leg. Enough is admitted to fill the sealed leg and the open one partially, leaving an empty space to the top of the tube at c of two and three quarter inches. A stout tube, six inches long and one-tenth of an inch in- terior diameter, ef is now fused on at c. Its lower end opens into the main siphon tube ; its upper end is turned over at f and is narrowed to a fine termination, so as barely to admit a pin, but is not closed. This serves to keep out dust, and in case of a little acid passing out, it does not flow over the scale and deface the divisions. At the back of this tube a scale is placed, divided into tenths of an inch, being numbered from above downwards. Fifty of these divisions are as many as will be required. Fig. 2 shows the termination of the narrow tube bent over the scale. From a point one- fourth of an inch above the stage d, down- wards beyond the bend, and to within half an inch of the wire z, the whole tube is carefully painted with India ink so as to allow no light to pass ; but all the space from a fourth of an inch above the stage d to the top of the tube a, is kept as clear and transparent as possible. This portion constitutes the sen- tient part of the instrument. A light metallic or pasteboard cap, A D, fig. 3, closed at the top and open at the bottom, three inches long and six-tenths of an inch in diameter, black- ened on its interior, may be dropped over this sentient tube; it being the office of the stage d to receive the lower end of the cap when it is dropped on the tube so as to shut out the light. The foot of the instrument k lis of brass, it screws into the hemispherical block m, which may be made of hard wood or ivory; in this three holes, p qr, are made to serve as mercury cups ; they should be deep and of small diameter, that the me- tal may not flow out when it inclines for the purpose of trans- ferring. A brass cylindrical cover L M, L M may be put over the whole; when it is desirable to preserve it in total darkness, it should be blackened without. Secondly, of the Fluid Part. — The fluid from which the mix- ture of chlorine and hydrogen is evolved, and by which it is 410 Professor Draper's Description of the Tithonometer. confined, is yellow commercial muriatic acid, holding such a quantity of chlorine in solution that it exerts no action on the mixed gases as they are produced. From the mode of its preparation it always contains a certain quantity of chloride of platina, which gives it a deep golden colour, a condition of considerable incidental importance. When muriatic acid is decomposed by voltaic electricity its chlorine is not evolved, but is taken up in very large quantity and held in solution; perhaps a bichloride of hydrogen results. If through such a solution hydrogen gas is passed in minute bubbles, it removes with it a certain proportion of the chlorine. From this therefore it is plain, that muriatic acid thus decom- posed will not yield equal measures of chlorine and hydrogen unless it has been previously impregnated with a certain vo- lume of the former gas. Nor is it possible to obtain that de- gree of saturation by voltaic action, no matter how long the electrolysis is continued, if the hydrogen is allowed to pass through the liquid. Practically, therefore, to obtain the tithonometric liquid, we are obliged to decompose commercial muriatic acid in a glass vessel, the positive electrodes being at the bottom of the vessel and the negative at the surface of the liquid. Under these circumstances, the chlorine as it is disengaged is rapidly taken up, and the hydrogen being set free without its bubbles passing through the mass, the impregnation is carried to the point required. Although this chlorinated muriatic acid cannot of course be kept in contact with the platina wires without acting on them, the action is much slower than might have been anti- cipated. I have examined the wires of tithonometers that had been in active use for four months, and could not per- ceive the platina sensibly destroyed. It is well however to put a piece of platina foil in the bottle in which the supply of chlorinated muriatic acid is kept ; it communicates to it slowly the proper golden tint. The liquid, being impregnated with chlorine in this man- ner until it exhales the odour of that gas, is to be transferred to the siphon a b c of the tithonometer, and its constitution finally adjusted as hereafter shown. Thirdly, of the Voltaic Battery. — The battery, which will be found most applicable for these purposes, consists of two Grove's cells, the zinc surrounding the platina. The following are the dimensions of the pairs which I use. The platina plate is half an inch wide and two inches long ; it dips into a cylinder of porous biscuit- ware of the same di- mensions, which contains nitric acid. Outside this porous Professor Draper's Description of the Tithonometer. 411 vessel is the zinc, which is a cylinder one inch diameter, two inches long and two-tenths thick; it is amalgamated. The whole is contained in a cup, two inches in diameter, and two deep, which also receives the dilute sulphuric acid. The force of this battery is abundantly sufficient both for preparing the fluid originally and for carrying on the titho- nometric operations ; it can decompose muriatic acid with ra- pidity, and will last with ordinary care for a long time. Before passing to the mode of using the tithonometer, it is absolutely necessary to understand certain theoretical condi- tions of its equilibrium ; to these in the next place I shall revert. Theoretical Conditions of Equilibrium.— The tithonometer depends for its sensitiveness on the exact proportion of the mixed gases. If either one or the other is in excess a great diminution of delicacy is the result. The comparison of its indications at different times depends on the certainty of evol- ving the gases in exact, or at all events, known proportions. Whatever, therefore, affects the constitution of the sentient gases alters at the same time their indications. Between those gases and the fluid which confines them certain relations sub- sist, the nature of which can be easily traced. Thus, if we had equal measures of chlorine and hydrogen, and the liquid not saturated with the former, it would be impossible to keep them without change, for by degrees a portion of chlorine would be dissolved, and an excess of hydrogen remain ; or, if the liquid was overcharged with chlorine, an excess of that gas would accumulate in the sentient tube. It is absolutely necessary, therefore, that there should be an equilibrium between the gaseous mixture and the confining fluid. As has been said, when muriatic acid is decomposed by a voltaic current, all the chlorine is absorbed by the liquid and accumulates therein, the hydrogen bubbles however as they rise withdraw a certain proportion, and hence pure hydrogen passed up through the tithonometric fluid becomes exceed- ingly sensitive to the light. There are certain circumstances connected with the consti- tution and use of the tithonometer which continually tend to change the nature of its liquid. The platina wires immersed in it by slow degrees give rise to a chloride of platina. It is true that this takes place very gradually, and by far the most formidable difficulty arises from a direct exhalation of chlo- rine from the narrow tube ef, for each time that the liquid descends, a volume of air is introduced, which receives a cer- 412 Professor Draper's Description of the Tithonometer. tain amount of chlorine which with it is expelled the next time the battery raises the column to zero; and this, going on time after time, finally impresses a marked change on the liquid. I have tried to correct this in various ways, as by terminating the end f with a bulb; but this entails great inconvenience, as may be discovered by any one who will re- flect on its operation. When by the battery we have raised the index to its zero point, if the gas and liquid are not in equilibrio, that zero is liable to a slight change. If there be hydrogen in excess the zero will rise, — if chlorine, the zero will fall. In making what will be termed " interrupted experiments," we must not too hastily determine the position of the index on the scale at the end of a trial. It is to be remembered that the cause of movement over the scale arises from a con- densation of muriatic acid, but that condensation, though very rapid, is not instantaneous. Where time is valuable, and the instrument in perfect equilibrium, this condensation may be instantaneously effected, by simply inclining the instrument so that its liquid may pass down to the closed end a, but not so much as to allow gas to escape into the other leg ; the in- clination of the two legs to each other makes this a very easy manipulation, and the gas thus brought into contact with an extensive liquid surface yields up its muriatic acid in a mo- ment. Directions for using the Tithonometer. Preliminary adjust- ment.— Having transferred the liquid to the sealed end of the siphon, and placed the cap on the sentient extremity, the voltaic battery being prepared, the operator dips its polar wires into the cups p q, which are in connexion with the wires xy. Decomposition immediately takes place, chlorine and hydrogen rising through the liquid, and gradually depressing it, whilst of course a corresponding elevation takes place in the other limb; this operation is continued until the liquid has risen to the zero. It takes but a few seconds for this to be accomplished. The polar wires having been disengaged, the tithonometer is removed opposite a window, care being taken that the light is not too strong. The cap is now lifted off the sentient ex- tremity a d, and immediately the liquid descends. This ex- posure is allowed to continue, and the liquid suffered to rise as much as it will to the end a. And now, if the gases have been properly adjusted, an entire condensation will take place, the sentient tube a d filling completely. In practice this pre- cision is not however obtained, and if a bubble as large as a Professor Draper's Description of the Tithonometer. 413 peppercorn be left, the operator will be abundantly satisfied with the sensitiveness of his instrument. Commonly, at first, a large residue of hydrogen gas, occupying perhaps an inch or more, will be left. It is to be understood that even this large surplus will disappear in a few hours by absorbing chlorine. But this is not to be waited for ; as soon as no further rise takes place in a minute or two, the siphon is to be inclined on one side, and the residue turned out into the open leg. Now, recurring to what has been said on the equilibrium, it is plain that this excess of hydrogen arises from a want of chlorine in the tithonometric liquid. A proper quantity must therefore be furnished by proceeding as follows. The sentient tube being filled with the liquid by inclination, connect the polar wires with p q, as before. These may be called generating wires. Allow the liquid to rise in b c, until the third platina wire z, which may be called the adjusting wire, is covered an eighth of an inch deep. Then remove the negative wire from the cup p into the cup r, and now the con- ditions for saturating the liquid are complete; hydrogen esca- ping away from the surface of the liquid at z, and chlorine continually accumulating and dissolving between x and d. This having been carried on for a short time, the gas in a d is to be turned out by inclination and the instrument re- charged. That a proper quantity is evolved is easily ascer- tained by allowing total condensation to take place, and ob- serving that only a small bubble is left at a. It will occasionally happen in this preliminary adjustment, that an excess of chlorine may arise from continuing the pro- cess too long. This is easily discovered by its greenish-yel- low tint, and is to be removed by inclining the instrument and turning it out. Thus adjusted, everything is ready to obtain measures of any effect, there being two different methods by which this can be done, — 1st, by continuous observation; 2nd, by inter- rupted observation. Of the Method of continuous observation. — This is best de- scribed by resorting to an example. Suppose, therefore, it is required to verify Table I., or, in other words, to prove that the effect on the tithonometer is proportional to its time of exposure. Put on the cap of the sentient tube a d, connect the polar wires with p q, and raise the liquid to zero. Place the tithonometer so that its sentient tube will receive the rays properly. At a given instant, marked by a seconds watch, remove the cap A D, and the liquid at once begins to descend. At the end of the first minute read off the division over which it is 414; Professor Draper's Description of the Tithonometer. passing. Suppose it is 7. At the end of the second do the same, it should be 14; at the end of the third 21, &c. &c. This may be done until the fiftieth division is reached, which is the terminus of the scale. Recharge the tube by a momentary application of the polar wires : but it is convenient first to remove any excess of mu- riatic acid gas in the sentient tube by allowing it time for con- densation ; or, if that be inadmissible, by inclining a little on one side, so as to give an extensive liquid contact. Of the Method of interrupted observation. — It frequently happens that observations cannot be had during a continuous descent, as when changes have to be made in parts of appa- ratus or arrangements. We have then to resort to inter- rupted observations. This method requires that the gas and liquid should be well adjusted, so that no change can arise in volume when extensive contact is made by inclination. The tithonometer being charged, place it in a proper posi- tion. At a given instant remove its cap, and the liquid de- scends. When the time marked by a seconds watch has elapsed, drop the cap on the sentient tube. The liquid si- multaneously pauses in its descent, but does not entirely stop, for a little uncondensed muriatic acid still exists, which is slowly disappearing in the sentient tube. Now, incline the instrument for a moment on one side, so that the liquid may run up to the cord «, but not so much as to let any gas escape. Restore it to its position and read off on the scale. It is then ready for a second trial. The difference between continuous and interrupted obser- vation is this, that in the latter we pause to wash out the mu- riatic acid, and though this is effected by the simplest of all possible methods, continuous observations are always to be preferred when they can be obtained. I have extended this paper to so great a length that many points on which remarks might have been made must be passed over. It is scarcely necessary to say that the sentient tube must be uniformly and perfectly clean. As a general rule also, the first observation may be cast aside, for reasons which I will give hereafter. Further, it is to be remarked, as it is an essential principle that during different changes of vo- lume of the gas its exposed surface must never vary in extent, the liquid is not to be suffered to rise above the blackened portion at d. If the measures of the different parts be such as have been here given, this cannot take place, for the liquid will fall below the fiftieth division before its other extremity rises above d. Mr. Hunt on the Spectral Images q/M. Moser. 415 The same original volume of gas in a d will last for a long time, as we keep replenishing it as often as the fiftieth division is reached. The experimenter cannot help remarking, that on suddenly exposing the sentient tube to a bright light, the liquid for an instant rises on the scale, and on dropping the cap in an in- stant falls. This important phasnomenon, which is strikingly seen under the action of an electric spark, I shall consider hereafter. In conclusion, as to comparing the tithonometric indication at different times, if the gases have the same constitution, the observations will compare ; and if they have not the value can from time to time be ascertained by exposure to a lamp of con- stant intensity. To this method I commonly resort. From the space occupied in this description the reader might be disposed to infer that the tithonometer is a very complicated instrument and difficult to use. He would form, however, an erroneous opinion. The preliminary adjustment can be made in five minutes, and with it an extensive series of measures obtained. These long details have been entered into that the theory of the instrument may be known, and optical artists construct it without difficulty. Though surprisingly sensitive to the action of the indigo ray, it is as manageable by a careful experimenter as a common differential thermometer. University of New York, Sept. 26, 1843. L. On the Spectral Images of M. Moser; a Reply to his Animadversions, Sj-c. By Robert Hunt, Secretary to the Royal Cornwall Polytechnic Society *. To U. Taylor, Esq. Dear Sir, [ CANNOT but regret that any remarks which I may have made on the very interesting discoveries of Professor Moser, should have so far disturbed the philosophic quiet of his mind, which it is so important to maintain, when engaged in the in- vestigation of truth, as my paper on Thermographyf appears to have done. I am, however, called upon to reply to M. Moser's remarks, which appear in your Journal for Novem- ber, in a way that is very unpleasing to me. However much men may differ in the interpretations they give to obscure phaenomena, I do not fancy they will approach any nearer the truth, or facilitate the progress of inquiry, by indulging in personal attacks. 1 have ever pursued my inquiries with, I hope, but one object in view. The investigation of curious phaenomena has ever been a pleasure to me, and an occasional discovery has been its own exceeding great reward. I never * Communicated by the Author. f Phil. Mag., Dec. 1842. 416 Mr. Hunt on the Spectral Images q/M. Moser, expected to be charged with repeating the experiments of others and giving them out as my own discovery. The mind of that man, who thinks to elevate himself by any paltry piracy of this kind, is of a low order, and the attempt to defraud the public by any such means is certain, sooner or later, to have its full amount of punishment in the contempt of the many and the pity of the few. But I feel myself put upon my defence. The note you have placed at the foot of page 356 partly re- lieves me from the charge *, but not entirely ; I must therefore presume upon your kindness, and as briefly as possible ex- plain the matter as it stands. Immediately after the meeting of the British Association at Manchester, I heard, for I was not present at that meeting, of the announcement of M. Moser's discovery, that " when two bodies are sufficiently near, they impress their images upon each other." I immediately tried some experiments, and was much interested in the results. Now, it will be re- membered, this announcement at Manchester was unaccom- panied by any statement of experiments. I had already made a great number of experiments when I received the Comptes Rendus for the 18th of July and the 29th of August, 1842, containing communications, " Sur la formation des images Daguerriennes," which I have distinctly referred to in the very first sentences of my paper on Thermography. These communications gave me M. Moser's views, but not the ex- perimental evidence by which he arrived at these views; and it was not until the publication of the Eleventh Part of the Scientific Memoirs, in February 1 843, that I gained any fur- ther information on this subject. M. Moser's memoirs appear to have been published in Poggendorff's Annalen about June or July 1842, but it is unfortunate for me, that the thoughts and labours of the thinking German nation are sealed books until they appear in my own language, owing to xmy entire ignorance of theirs. The valuable Annalen I have never yet by any chance seen. On the 8th of November I read my paper before the Royal Cornwall Polytechnic Society, the President, Sir Charles Lemon, in the Chair; and this commu- nication, which was immediately printed, and which appeared in many of the leading scientific journals for December, was, I believe, the first series of experiments on this subject pub- lished in England. * Our conviction, upon a comparison of dates, that the charge was groundless, did not deter us from publishing a translation of the paper containing it. On the contrary, we thought it more just towards those included in M. Moser's attack, that they should not remain unaware of misrepresentations which were in circulation abroad, and thus be enabled to meet them. — Edit. in reply to his Animadversions. 417 Now, with regard to the experiments themselves, surely Professor Moser will not claim as his own the experiments, of placing a coin on a glass or polished metal plate, or of writing on glass with a piece of steatite, and bringing out the images by breathing on them. Dr. Draper in 1840 published this*; and when a schoolboy, twenty years ago, I tried these expe- riments without ever suspecting their scientific value, which M. Moser was the first to call attention to. M. Moser, in his memoir ' On the Action of Light on Bodies,' states, ** Silver and other metallic plates were made warm, and cold bodies, variously cut stones, figures of horn, pasteboard, cork, coins, &c. allowed to remain on them for some time." It must be distinctly understood, that at the meeting of the British Association it was stated, that the images could be brought out by the vapours of water, mercury, &c; but with- out being, at the period of making my experiments, October 1842, aware of the above, which I did not see until February 1843, my first simple experiments convinced me that some connexion existed between the conducting powers of bodies, as it regards heat, and the strength of the impressions made by them. With this in view I tried good and bad conductors of heat, from copper plates and coins to platina ones, glass and charcoal. These constitute the experiments given in para- graphs from 2 to 7 of my paper. Now if M. Moser used all these materials, and I do not doubt but he may have done so, he certainly did not make his experiments with the same ob- ject in view, or he would not have neglected to observe the fact, which I was the first to announce, that " bodies which are bad conductors of heat placed on good conductors make de- cidedly the strongest impressions." I am quite ready to give up any claim to the experiments, but I reserve to myself the interpretation they afford. M. Moser says, " I cannot name a single experiment, &c. &c. which I had not previously described." Will M. Moser oblige by directing me to any of his memoirs, where may be found the experiments named in paragraph 8, which show the power of electrical discharges in evoking again these mysteri- ous images after they have been effaced ? Or that in paragraph 15, where a copper plate is described to have been so changed in its molecular constitution, by being warmed in contact with a piece of paper, that it readily amalgamated with mercury over the parts which the paper covered, but not so over the other portions of the plate? Nearly all the other paragraphs of my paper, to the 22nd, are details of experiments with coloured glasses and transpa- rent bodies, placed upon plates of unprepared copper and • In Phil. Mag., S. 3, vol. xvii. p. 217.— Edit. Phil. Mag. S, 3. Vol. 23. No. 154. Dec. 1843. 2 E 418 Mr. Hunt on the Spectral Images of M. Moser, silver. I find that M. Moser has also used coloured glasses, but principally upon iodized silver plates. It is to be lamented that he has made so great a number of very careful experi- ments in this way; for, by regarding the colour of the glass, and the colour of. the ray which permeates it, as the same, he has been led to some very incorrect conclusions, as the slight- est acquaintance with the valuable labours of Sir John Her- schel would have shown him. My use of coloured glasses in these experiments was confined to the heating powers of the dif- ferent colours, and these were contrasted with smoked glasses, and the like, the results showing, whether the experiments were made in sunshine or at night, that those glasses, the red and blackened ones, which admitted the permeation, or ab- sorbed the largest quantity of heat, made the most decided impressions on metal plates. I cannot see how M. Moser makes out his claim to these experiments, except it is upon the principle that Professors Faraday and Daniell are guilty of scientific piracy in publishing, in their valuable memoirs, re- sults obtained with zinc and copper plates, Volta having used the same kind of plates before them. I have only to deal with one more of Professor Moser's charges. He says, " He has not devised a single new experi- ment, for even those which appear to him sufficiently import- ant to be adopted as the running head of his paper, ' The art of copying engravings, or any printed characters from paper on metal plates,' will be found nearly word for word in the Annalen, vol. lvii. p. 570." The latest memoir of M. Moser with which I am acquainted, is the 18th article in the 3rd vol. of the Scientific Memoirs, which is stated to be "from Pog- gendorfF's Annalen, Band lvii., 1842, No. 9. p. 1." I presume M. Moser alludes to a more recent publication. He, how- ever, relieves me from a difficulty by saying, "It is that expe- riment in which I caused a seal to depict itself on mercury with which a pure or silvered copper-plate had been coated, and af- terwards produced the image in the iodine vapours." Now we will examine the similitude between this and my published ex- periment. A copper plate is amalgamated by nitrate of mercury, and a line or mczzotinto engraving, a wood-cut or li- thographed print, on paper, is placed upon it for a few hours. With certain precautions the plate is exposed to the vapour of mercury, this vapour attacks those parts of the plate which correspond with the white parts of the paper, and a faint image is formed ; the plate is now placed in the iodine box for a little time, and its vapour attacking and blackening those parts of the plate, which correspond with the dark portions of the paper, brings out a very decided and beautiful copy of the print. I am quite satisfied to leave it to yourselves and your readers to say if this "sufficiently important" experiment is in reply to his Animadversions. 419 M. Moser's, or otherwise. I have seen paragraphs stating that M. Moser has succeeded in copying engravings from paper, but I do not, even now, know his experiments. I shall not dispute with M. Moser the point of priority, but I trust he will do me the justice of acknowledging, that he has judged hastily in accusing me of having appropriated his experiments without acknowledgement. In the paper in question I thought I had sufficiently acknowledged the high merits of Professor Moser ; I again do so. He has opened a new and important path of physical inquiry, which promises to lead to some great truths connected with the constitution of matter, and the ope- rations of the imponderable elements ; at the same time, how- ever, that I admit the importance of his discoveries, I must be allowed, for the present, to dissent from his conclusions. It is not my intention to offer any further remarks in expla- nation of that portion of M. Moser's paper which particularly applies to myself, but I must be allowed this opportunity of reviewing some of the opinions he has put forth, and of ex- plaining my reasons for differing from him. M. Moser states that every body must be considered as self- luminous, and he appears to view the accelerating power ex- erted by heat, as stated in his own experiments, as the influ- ence of caloric increasing the intensity of the invisible radia- tions, whilst as " their temperature becomes higher their re- frangibility decreases." It becomes necessary, in the first place, to ascertain upon what evidence this self-luminosity of bodies is asserted. It has been long known, that light acting upon ioduret of silver, alters its condition, and renders it capable of condensing the vapours of mercury in a remarkable manner; — this constitutes the Daguerreotype. It has been shown that if we breathe over portions of a metallic plate, the other parts being covered, and then the vapour is allowed to dry off, the plate is in a condition to receive vapours over definite spaces, in the same manner as if it had been exposed to the light. Again, any solid body being placed for a short time on a po- lished plate of metal or of glass, either of them become sus- ceptible of receiving vapory deposits, which will mark di- stinctly the spaces occupied by the bodies in contact. " By these experiments, I think," says Moser, ** I have proved that contact, cotidensation qf vapours, and light produce the same effect on all bodies'" and hence he rushes to the conclusion that all bodies are self-luminous, and has even speculated on the co- lour of the latent light of vapours, in a way, which betrays his fears lest the hypothesis he has framed should be destroyed by his own results. Light, or rather, as I am inclined to think, some element intimately connected with light, and 2E2 420 Mr. Hunt on the Spectral Images of M. Moser, having its origin in the sun, but broadly distinguished from it by its producing no influence on the organs of sight, certainly *' so modifies the surfaces of bodies that they condense vapours otherwise than usual ;" and like modifications are produced by condensing vapours on parts of the surface, or by placing other bodies in contact with it. Whatever method we may adopt to disturb the surface of any body, be it metallic or vi- treous, we have an unequal condensation of vapour. If with- out touching the surface of a metal plate, we subject it to the disturbance produced by a blow or two on the back of the plate, we shall find an irregular deposit of vapour if we breathe on it. The molecular change which bodies undergo, under the most trifling circumstances, is certainly one of the most curious matters with which photography has brought us ac- quainted. By light, by heat, by electricity we can dispose plates to receive vapours over definite spaces; by lowering the temperature of parts of any body, the same effect is produced, and by any mechanical force we do the same. If we place a copper plate so that one half of it shall rest on a cold body, and apply the heat of a spirit lamp for a few seconds to the other half, carefully avoiding touching the polished surface, and then expose the plate, when quite cold, to mercurial va- pour, it will be found that a larger quantity of vapour is depo- sited over the half that was warmed than over the other half. If a piece of wood is placed upon a polished plate, and one or two gentle blows is given to it, the plate will exhibit, when submitted to vapour, not merely the shape of the wood, but a perfect picture of its fibres. Again, if we give a metal plate a few gentle blows upon the back, the surface will distinctly show, when exposed to vapour, the spaces corresponding with those on the back on which the hammer fell. If we sub- ject portions of a metal plate to any chemical action, even though it may be inappreciable to the sight, it will exhibit the spaces to which the action was confined, the moment it is ex- posed to the influence of vapour. These experiments afford us a sufficient amount of evidence to conclude, that any cause producing a change upon solid sur- faces disposes them to condense vapours unequally. They also prove the correctness of all the statements made by M. Fizeau, Professor Grove, Mr. Prater * and others ; and at the same time as they do this, they convincingly show us, that these observers have only been dealing with a few curious facts, which cannot be allowed to explain these remarkable phaeno- mena, to which, in particular, M. Moser wishes to direct at- tention, viz. the power which the solar rays have of produ- * See p. 225 of the present volume. — Edit. in reply to his Animadversions. 421 cing definite changes in the condition of the surface of solid bodies, and the remarkable property of two substances in juxtaposition, inducing upon each other changes which may be rendered evident to the senses ; and these changes, it must be remembered, are not confined to the surface merely, but they penetrate to a considerable depth into the solid structure of the mass, as I have already proved in several of my published experiments. These results, in addition to many which I have previously given, also show the impropriety of considering these spectral images as the effects of " invisible light" " light radiated in absolute darkness" as they have been by M. Moser. I must in this place express my conviction, that any term involving an idea contrary to our received ideas, is calculated to produce much confusion. Light is that element which affects the organ of sight, enabling us to distinguish objects; that which does not do this is no longer light. The prismatic spectrum has been proved to consist of one element giving light and colour, of another element affording heat, and of a third element, which is active in producing chemical change. Now M. Moser in- forms us that it is neither of these, but a class of rays which are still more refrangible than those which have been called the "invisible chemical rays." "According to my experi- ments," he says, "the invisible rays of light pass very readily through aqueous solutions of various kinds, and through dif- ferent oils, but they decidedly do not pass through the thinnest plates of glass, mica, or rock-salt, &c." Now, as M. Moser has not given us his experiments, it is very difficult to deal with them. In the first place, he has not, as it appears to me, as yet afforded any evidence of the existence of such a class of rays as those he speaks of; and if the " thinnest plates of glass, &c." are not permeated by these rays, upon what prin- ciple does he, by the use of coloured glasses, prove "that light and mercurial vapour are identical in their effects?" The prism must be useless in this inquiry on M. Moser's own showing; I am therefore quite at a loss to know by what means he has succeeded in establishing, with so much accu- racy, the refrangibility of these "invisible rays of light." I am very far from denying that the phaenomena in question have been produced by invisible solar emanations. I am not at all prepared to deny the absorption of such emanations by solid bodies, or their existence in a latent state, or their ra- diation in darkness. I contend only that light has nothing whatever to do with the phaenomena. In the present state of the inquiry it does appear to me that heat is a very active^ agent in producing the effects in question ; indeed M. Moser himself says " if the temperature be raised, they (the invisible 422 Mr. Hunt on the Spectral linages qfM. Moser, rays of light) pass very readily plates of glass and mica." I shall have to name an experiment or two presently which will show, in a striking manner, the influence of the "calorific rays" on metallic plates. I regard those emanations, which are the acting ones in all our photographic operations, as possessing powers of the most energetic and extraordinary kinds ; powers which are in constant activity, decomposing and recomposing, maintaining the conditions of growth and decay, of vitality and corruption; indeed, effecting that mighty system of change, which is the order of the visible creation, and these may be the radiations by which all the spectral images of Moser are pro- duced. Sir John Herschel* was inclined to attribute these phfenomena to a class of rays ranging above the red rays of the spectrum, and to which he gave the name of " parathermic rays." The evidence, however, of the existence of these rays, as a distinct class, is not sufficiently clear even to satisfy the mind of this talented and most indefatigable observer, to whom we are indebted, more than to any other person, for our know- ledge of the conditions of the solar spectrum. At the Cork meeting of the British Association I commu- nicated the results of some experiments made with the pris- matic spectrum itself, which is the only way in which, as far as I am aware, we can arrive at any satisfactory determina- tion on the point in question. A condensed pris- matic spectrum was, by means of a good heli- ostat, maintained in one place upon a very highly polished copper plate for three hours. At the expiration of that time, the plate was exposed to the action of mercurial vapour. This vapour was con- densed over the whole plate, but in very dif- ferent proportions be- yond and within the limits of the spectrum. The space occupied by the luminous image was evidently protected from that influence which disposed the other parts of the plate to condense the * Philosophical Magazine, July 1843, (pres. vol.) p. 510. in reply to his Animadversions. 423 vapour, but the space occupied by the extra spectral red rays, had undergone that change, which renders metals most suscep- tible to the action of vapours, and a thick white line of vapour very distinctly marked this calorific region, giving a spectral image similar to the accompanying figure. It does not appear that so long an exposure to solar influence was necessary, for a similarly condensed spectrum was allowed to traverse over a polished copper plate for a few hours. On submitting this plate to vaporization, a line of thickly-deposited mercurial vapour distinctly marked the path of the extra-spectral red rays. I should explain that I mean the extreme red ray of the spectrum, which is seen when it is looked at through a cobalt-blue glass, and which has been made the subject of much attention by Sir John Herschel, and some rays below this extreme red ray. These rays cover a space which cor- respond as nearly as possible with the large heat-spot in Sir John HerschePs thermographic spectrum. I have been ex- ceedingly anxious to repeat these experiments on other metals, but the unfavourable state of the weather, and the advanced season has compelled me to abandon this examination for the present. M. Moser has stated that this "invisible light" will not permeate glass. In my first communication on " Thermo- graphy " (Phil. Mag. S. 3., vol. xxi. Dec. 1842, p. 464), para- graph 9, I have shown that some influence is exerted through red glasses which is not exerted through blue glasses. It may be said that this was an influence radiated from the red glass, in greater quantity than from the blue. I think, however, that I have distinct proof of the permeation of the rays which are active in producing these spectral images. Three very large flat white glass bottles were provided, and filled with coloured fluids, blue, yellow and red. The light had to pass through about 1^ inch of fluid in each case, this was very carefully examined with the prism, and the depth of colour adjusted until they represented, very fairly, the three great divisions of the spectrum. Figures were cut in paper and placed upon highly polished copper plates, being pressed down by these bottles of coloured fluid. This arrangement being left in the dark during a night, the plates were sub- mitted to vapour, and they exhibited, each of them, impres- sions of the paper figures, in which little or no difference could be detected. The same arrangement was exposed for different periods, varying from half an hour to two hours, to the influ- ence of the sun's rays. Under the bottle containing the red fluid, a most perfect image was formed by mercurial vapour, even after the shortest exposure. Prolonged exposure gave a 4>24 Mr. Hunt on the Spectral Images qfM. Moser, faint image on the plate under the yellow fluid, but no trace of an impression could be detected, by the influence of the same exposure, under the blue fluid. Surely these results prove, that the calorific rays are the most active in these phaenomena ; and instead of inventing the purely conjectural notion of " invisible light," is it not much more rational, when we have distinct evidence of the powerful action of heat, to look for an expla- nation of these phaenomena in the calorific radiations, which are equally active in light or darkness ? Instead of assuming that bodies are all self-luminous for the purpose of explaining these curious facts, which " self-luminosity " we are not in a condition to prove, is it not more consistent with the spirit of inductive philosophy, to seek for the cause in the invisible ra- diations of heat, which we know take place under all cir- cumstances? And it is admitted, even by Moser himself, that heat is a powerful accelerating agent. M. Moser has not told us how he has determined that his dark light passes readily through aqueous solutions and oils. I have tried some experiments which are instructive, and I therefore record them. Having put an edge of wax around a polished copper plate, to the depth of one-eighth of an inch, I covered the plate with water, and upon two small pieces of glass I supported, by the edges, a silver medal, so that it just touched the upper surface of the water; in twelve hours the plate was much tarnished over every part, except that directly under the medal, which remained as bright as at first. Under one of the pieces of glass a very decided change of colour was produced, and from its whiteness I was at first inclined to think, that silver had been removed from the medal, and depo- sited on the plate; I have, however, since proved that it was an oxidation of the copper plate merely. The same arrange- ment was made with very fine olive oil, and the result was si- milar ; but upon leaving the medal and plate undisturbed for some days, the whole surface of the copper was oxidized, the oil became a very fine green colour, and the under surface of the silver was covered with a film of copper. Here we have analogous phaenomena to those we have been considering, but in these cases it is very evident the cause was neither light nor heat, but voltaic electricity. . The plates, after the water and oil were removed, were thoroughly cleaned and exposed to the vapour of mercury, which gave images of the medal in outline, and of the glasses. It may not be out of place here to say a few words relative to the explanation given by M. Fizeau of the production of these images. There is no doubt " if different parts of a po- lished surface are unequally soiled by extraneous bodies, even in reply to his Animadversions. 425 in an exceedingly minute quantity," that it will condense va- pours irregularly. But in the communication which I made to the British Association at Cork, I stated several experi- ments, which appear to me to prove that the images are pro- duced quite independently of any layer of organic matter. Copper plates were polished with water only and boiled, and all the things placed on these plates were boiled also, yet very perfect images were produced. I have since tried the effect of exposing the plates, &c. separately to a very strong heat, and when cold placing them in contact; there has been no apparent difference between the images formed under these circumstances, and those formed upon plates, and with medals, &c. which have been purposely covered with very slight films of organic matter. I have also repeated these experiments many times, in the best vacuum which could be maintained with a good air-pump, to avoid the action of any vapours on the metal or glass plates, and in every case the images have been well defined. I cannot imagine any volatile film of the kind described, exerting an influence to so great a depth into the solid metals as I find to be the case. Often I have, by polishing, removed layers of metal, and yet the images have been reproduced by exposing the plate to vapour; and in pa- ragraph 8 of my paper on Thermography, above alluded to, I have stated the result of an experiment in which electricity reproduced a succession of images which had been obliterated from the copper plate. It has been suggested that electricity may be engaged in the production of these spectral figures. I have just tried an experiment which appears to show the probability of this ele- ment's being involved in some way in these very complicated phaenomena. I arranged four electro-positive metals, nickel, bismuth, cadmium and silver, and two electro-negative ones, arsenic and antimony, on a copper plate, and they were allowed to rest upon it for three hours. Being removed, the plate was submitted to the vapour of mercury. The space covered by the nickel was marked, by being left free of vapour ; that on which the cadmium lay was still more decidedly marked in this way; where the bismuth was placed the image was ex- ceedingly faint, but still it was observable by a deficiency of vapour ; and the silver was more decidedly outlined with va- pour, but none on the spot it covered. On the contrary, the space occupied by the antimony was covered in a most remark- able manner with vapour, presenting a perfectly white spot, which in all positions distinguished it from the other parts of the plate, whilst the arsenic left no trace behind. I think I have now shown, that many different causes may 426 Dr. Stenhouse on Thcine and its Preparation. produce similar effects, and certainly I have established the necessity of examining all the phaenomena with great care and attention, before we attempt to establish a theory which shall embrace the whole class. I have given the name Thermo- graphy to these images, under a conviction that heat was most importantly engaged in producing them, and I see no reason for altering the name. At the same time I beg to be very di- stinctly understood, that I am not wedded to this opinion ; I feel conscious that we are dealing with some of the most sub- tile agents in nature, and that we cannot too jealously guard against the deceptions of the senses. That which heat appears to produce, may be the creation of some other element, which is excited only by calorific influence. But although I hold my judgement under suspense, particularly when I find light, heat, electricity, chemical action and mechanical force, all producing the same effects, I cannot at present entertain the idea of " invisible light," although M. Moser states, that in his memoir on Vision, he has demonstrated its existence. In con- clusion, I must hope that I have been successful in proving that I have not in this instance, or in any other, endeavoured to appropriate the experiments of another. I have ever stu- diously endeavoured to give the merits of even the slightest suggestion to its author, and if in any one instance, in the case of Professor Moser, I have not done so, I have erred through ignorance, and not by design. I cannot, however, detect any grounds for M. Moser's attack. I commenced my first paper with a statement of his results, and I concluded it by giving my opinion on the importance of the discoveries he had made. I cannot, however, allow myself to be led away from that which appears to me to be the legitimate path of inquiry by any unkind feeling. I shall pursue the investigation, and the moment I can convince myself that light is engaged in these phaenomena in darkness, I will acknowledge the correctness of Professor Moser's views with heartfelt pleasure. Falmouth, November 4, 1843. Robert Hunt. LI. On Theine and its Preparation. By John Stenhouse, Esq., Ph.D.* r|1HE process which I have found most suitable for preparing ■■■ theine, is both easy and productive, and is simply as fol- lows : — A decoction of tea is first treated with a slight excess of acetate of lead, which throws down the tannin, and almost • Communicated by the Chemical Society, having been read March 21 and May 2, 1843. Dr. Stenhouse on Theine and its Preparation. 427 all the colouring matters it contains. It is filtered while hot, and the clear liquor is evaporated to dryness. It forms a dark yellowish mass, which is to be intimately mixed with a quan- tity of sand, and introduced into Dr. Mohr's subliming appa- ratus. This should then be set upon a sand-bath, or still better on a metallic bath, and a moderate heat applied to it for 10 or 12 hours. The theine sublimes in beautifully white, anhydrous crystals, and is deposited upon the paper diaphragm which runs across the apparatus. The only thing to be ob- served is, that the temperature should never rise too high, as the more slowly the operation is conducted, the finer are the crystals and the greater is their quantity. The following are the results obtained by this process in four different trials. I. One pound of green Hyson tea gave 72 grains of per- fectly white theine, and 2 grains which were slightly coloured, in all 74 grains =1*05 per cent. II. 8 oz. of black Congo tea gave 34*5 grains pure theine, and 1*5 grain impure, in all 36 grains = 1*02 per cent. III. 6 oz. black Assam tea yielded 36 grains theine= 1*37 per cent. IV. 1 lb. of a cheap green tea called Twankay, gave 69 grains = 0*98 per cent. This last was sublimed too quickly, or it would probably have given a little more theine. We have four determinations of the theine in different specimens of tea by Mulder. He found in Chinese Hyson 0*43 per cent, theine, in congo 0'46 per cent, in Japanese Hyson 0*60 per cent., and in Japanese Congo 0*65 per cent. Mulder's process consisted in boiling the filtered decoction of the tea with magnesia, evaporating to dryness and then dissolving out the theine from the dry mass with aether. I have repeatedly tried his process, but found it very trouble- some and unproductive ; besides, the theine always requires more than one crystallization to render it quite pure, and the high price of aether, in Great Britain, at least, is a very serious inconvenience. It is to the presence of theine, I believe, that the bitter taste of tea is chiefly owing, and a tolerably correct idea of the quantity of theine in any specimen of tea may be formed from the degree of bitterness which it exhibits. The Assam tea, which yielded such a large proportion of theine, was remarkably bitter, but it appeared rather deficient in es- sential oil. Theine may also easily be made from coffee, by a slight alteration of the method just described; the coffee beans should not be roasted, as this would drive off much of the theine, but only slightly dried, and then ground or pounded, and repeatedly boiled with water till exhausted. The filtered 428 Dr. Stenhouse on Theine and its Preparation. decoction should first be precipitated while hot with basic acetate of lead. It should then be filtered and boiled with a little hydrated oxide of lead, which occasions a further preci- pitate, which is also to be separated by filtration. The clear liquor is to be evaporated to dryness, and sublimed exactly in the same way as the extract of tea. From a pound of coffee, in the course of several trials, I obtained from 12 to 18 grains of theine, which was sometimes not so perfectly white as that made from tea, as it was accompanied by a little more empyreumatic oil. It was easily rendered perfectly pure with scarcely any loss, by subliming it a second time at a very moderate temperature. A considerable quantity of theine may be easily made by sublimation, from either tea or coffee, in the course of two days, while the ordinary way of procuring it is both tedious and expensive. Several chemists have been induced to affirm that none of the beneficial effects which tea and coffee produced on the animal ceconomy, should be ascribed to the theine they contain, owing to the smallness of the quantity in which they supposed it to exist in these substances. Professor Liebig has, as is well known, recently advanced the very opposite opinion, and has rendered it highly probable that theine will yet be found to possess valuable medical properties. I hope that some medical practitioners may soon be induced to try if its utility in medicine will be found equal to the expectations which have been formed of it. In reference to the sublimation of theine, I may mention that I have found it advantageous to make a slight addition to Dr. Mohr's subliming apparatus, described in a previous paper. Instead of pasting the diaphragm of bibulous paper immediately on the rim of the iron pan, I paste it on a move- able rim of tin plate about an inch deep, which goes close round the outside of the pan, and which projects about one- eighth of an inch within it. When covered with the paper it exactly resembles a small sieve, and may be easily removed and replaced at pleasure. This enables us to stir the mass we may be subliming from time to time, and thus to heat the whole of it more equally. Now this could not be done in the usual apparatus without destroying the diaphragm. Theine in Paraguay Tea. — I am indebted to the kindness of Professor Christison for a quantity of Paraguay tea, or " yerba mate," as it is called. It consists of the leaves and small branches of the Ilex paraguayensis, which after being strongly roasted, have been reduced to a coarse powder. This substance is extensively used in South America as a substitute for tea. Its taste is very bitter, partly resembling Dr. Stenhouse on Theine and its Preparation. 429 that of ordinary tea, but also approaching somewhat to that of sumach. Its reactions were studied a number of years ago by Professor Tromsdorff, and are pretty fully stated in the eighteenth volume of the Annalen der Pharmacie, page 90. As my own observations coincide pretty closely with his, it appears unnecessary to give a detailed account of them. In proceeding to examine Paraguay tea for theine, acetate of lead was added to its decoction, which threw down a very dense greenish-yellow precipitate, and when this was removed by filtration, subacetate of lead also produced a considerable quantity of a bright yellow precipitate. The clear liquid when drawn off' and evaporated to dryness, left a good deal of a tenacious dark brown mass, which was very hygroscopic. When a little of it was subjected to distillation, a quantity of long flat crystals, exactly resembling the theine, sublimed into the sides and neck of the retort; and at the same time the very peculiar pungent smell which theine always emits when subliming became very perceptible. The remainder of the brownish-yellow substances already mentioned was reduced to fine powder, and intimately mixed with a large quantity of sand to prevent its agglutinating. It was then repeatedly agitated with aether in a stoppered bottle. The aethereal solution when poured off and distilled pretty low, deposited a quantity of crystals which were slightly coloured at first, but which were rendered perfectly white by repeated crystallizations. In their crystalline form, taste, so- lubility in water, alcohol and aether, and in all their reactions, they correspond exactly with ordinary theine. I may mention also, as an additional confirmation of the truth of this opi- nion, that in the course of some experiments upon theine, I have found an excellent test for that substance, by which its presence even in small quantities may be readily detected. It consists in the action of nitric acid upon theine, the effects of which are very different according to the quantity of the acid employed, and the length of time during which its action is continued. If theine is boiled for a ihw minutes with only twice or thrice its weight of fuming nitric acid, nitrous gas is given off in abundance, and a bright yellow solution is obtained. If a little of this liquid is taken out and gently evaporated to dryness in a porcelain basin, it leaves a deep yellow mass. If a drop of ammonia is then let fall upon it and a gentle heat is applied, a bright purple colour is immediately produced, which cannot be distinguished by the eye from that obtained from uric acid when similarly heated. This rich purple colour is permanent, its aqueous solution has a deep crimson shade. It also dissolves in 430 Dr. Stenhouse on Theine and its Preparation. spirits of wine, but it is not soluble in aether. Its colour is immediately destroyed by a solution of potash, which does not change it to an indigo-blue, as it does murexide. The substance which gives the red colour with ammonia does not appear to be crystal lizable. Now as I obtained the purple colour as readily from theine prepared from Paraguay tea as from that made from ordinary tea and coffee, I have not the least doubt that they are both identical substances. Unfortunately, from the smallness of the quantity of Paraguay tea in my possession, I have not been able to procure more than a few grains of the theine in a state of purity, and have been prevented therefore for the present from subjecting it to analysis. This however I have good reason to believe I shall be able to do in the course of a few weeks. The quantity of theine in Paraguay tea is by no means great, but no doubt much of what it originally contained had been destroyed by the injudicious way in which it is manufac- tured in Paraguay. The branches of the yerba tree are there cut down and spread upon a sort of wooden barbacue, under which large fires are kept burning. The yerba is therefore exposed to a very high temperature, and as theine sublimes pretty readily, it is plain that a good deal of it will necessarily be dissipated. It is somewhat singular, as Professor Liebig has observed, that the other three vegetable substances which are known to contain theine, tea, coffee, and guarana, though derived from plants of very different natural families, are all of them exten- sively employed as refreshing beverages. The circumstance that Paraguay tea, which is extensively applied to precisely the same purpose, also contains theine, is calculated, I should think, to give additional probability to the views of Professor Liebig on this subject. It is not unlikely that theine will soon be found to occur in other vegetables besides those in which it is already known. The easiest way perhaps to examine a plant for theine, which can be done in the course of a few hours, is to precipitate its infusion with subacetate of lead, to filter and evaporate the clear liquid to dryness. If a portion of the matter thus ob- tained be distilled, any theine it may contain will be imme- diately deposited in long flat crystals on the neck and sides of the retort. Camellia Japonica. — Through the kindness of Professor Balfour I was enabled to examine a quantity of the leaves of the Camellia Japonica, a plant whose botanical characters approach very closely those of Tea Bohea. I found that the Dr. Stenhouse on Theine and its Preparation. 431 Camellia does not contain any theine, and indeed its che- mical properties have very little resemblance to those of the tea plant. It has scarcely any of the bitter astringent taste by which both green and black tea are distinguished, and it ap- pears wholly devoid of any essential oil. It contains, how- ever, a small quantity of tannin, which gives olive-green pre- cipitates with salts of iron, and very copious yellow preci- pitates with acetate of lead. It occasions a very slight precipitate only in a solution of gelatine, and does not pre- cipitate tartar-emetic at all. Besides tannin the Camellia also contains a quantity of mucilage, some chlorophyle, and a waxy resinous matter. I have also examined the holly, the Ilex Aquifolium, for theine, but without success. Its chemical properties ap- peared pretty similar to those of the Camellia Jajponica. Action of Nitric Acid upon Theine. — As has been already mentioned, when theine is boiled with three or four times its weight of strong nitric acid, it is converted with copious evo- lution of nitrous gas into a deep yellow liquid, which when gently evaporated to dryness and slightly warmed, gives with ammonia a purple colour similar to that of murexide. This we have also mentioned is an excellent test for theine, and it forms a very pretty class experiment. The yellow liquid contains a very soluble crystalline body, which, when most of the nitric acid has been driven off, and the solution evaporated nearly to a syrup, crystallizes in long, hard, colourless needles. They have a rather sweetish taste, and when freed from ad- hering acid by repeated crystallizations, appear to be neutral to test paper, or at least only very slightly acid. Both this and the red colouring matter, however, appear to be the pro- ducts of the imperfect oxidation of the theine. If the theine is boiled for some hours in a great excess of nitric acid till a drop of the solution, when evaporated to dryness, is no longer yellow but white, the addition of ammonia does not produce any change of colour whatever. Both the yellow liquid and the substance which crystallizes in needles are then found to have disappeared. If the greater portion of the nitric acid is distilled off, and the liquor concentrated to a syrup as before, it readily concretes on cooling into a mass, containing a num- ber of large shining crystals. The mother-liquor which sur- rounds them appears to consist chiefly of very deliquescent ammoniacal salts. The crystals have a sweetish taste, grate between the teeth, and have a bright silvery lustre. Their crystalline form is not at all distinct, but they form large plates which readily crystallize. They dissolve in about three times their weight of cold water, but in a much smaller portion of 432 Dr. Stenhouse on Theine and its Preparation. hot water. They are readily soluble also in alcohol and aether, Their great solubility renders it a little difficult to purify them. The best way of doing so is by repeatedly crystallizing them out of water, and by pressing them between the folds of blotting-paper. When purified they are neutral, or at least redden litmus paper very feebly. The smallest portion of an alkali when added to their solution renders it alkaline. When heated they readily sublime, and are deposited in fine shining crystals on any cold object. They lake fire easily and burn with a bright flame. They do not give off ammonia when heated with potash. They occasion no precipitate or change of colour in solu- tions of nitrate of silver, acetate of lead, or sulphate of iron. I hope soon to subjoin the results of their analysis, with a more minute account of their properties. 5th. Two lbs. of coarse black bohea tea, such as usually sells for three shillings a pound, gave 99*5 grs. theine = 0*70 per cent. Analysis of the sublimed Theine. — 0*285 substance gave 0'5 125 carbonic acid, and 0*132 water = Calculated Number. Carbon ... 49*72 49*79 Hydrogen 5*14 5*08 Analysis of Theine from Paraguay Tea. — 0*2905 dried at 212° gave 0*525 carbonic acid, and 0*1345 water = Calculated Number. Carbon... 49*96 49*79 Hydrogen 5*145 508 The want of material unfortunately prevented me from de- termining the nitrogen also. Hydrochlorate of theine forms a double salt with chloride of platinum. It may be easily obtained in small but very distinct orange-coloured crystals by adding chloride of pla- tinum to a hot solution of theine in hydrochloric acid. In a few minutes as the liquor cools the crystals begin to form, and gradually subside as a mass to the bottom of the vessel. When dried at 212° and burnt, Calculated Per cent. Number. I. 0*461 grs. salt gave 0*112 of platinum = 24*29 . . . 24*48 II. 0*529 ... 0*130 ... = 24*57 111.0*5828 ... 0*143 ... = 24*53 IV. 0*458 ... 0*112 ... =24*45 These numbers lead to the rational formula C16 H10 N4 O4 H CI + Pt Cl% which gives 24*48 per cent, platinum, and double the ordinary atomic weight of theine. Dr. Stenhouse on Theine and its Preparation. 433 Atoms. Per cenl 16 C = 1222-960 10 H na 124-795 4 N = 708-160 4 O = 400-000 1 HC1 = 455-140 2 CI = 885*300 1 PI = 1233-26 = 24-48 5029-615 The salt employed for the first two determinations was washed with alcohol, and that for the last two with aether. This double salt appears therefore much more stable than the hydrochlorale of theine. I am proceeding to determine the quantity of its other constituents. Complete Analysis of the Theine prepared by Sublimation*. 0'285 gr. of the substance gave 0-5125 carbonic acid and 0-132 water. When burnt with oxide of copper, eight tubes gave carbonic acid and nitrogen in the proportion of four to one. Found. At. Calculated numbers. Carbon 49*72 16 Carbon = 49'798 Hydrogen 5-14 10 Hydrogen = 5-082 Nitrogen 28-78 2 Nitrogen =28-832 Oxygen 16-36 4 Oxygen =16-288 100-00 100-000 Theine from Paraguay Tea. Through the kindness of my friend Professor Gardner, I have procured an additional quantity of Paraguay tea, which has enabled me to complete the analysis of the theine it con- tains, and also to determine its quantity. The easiest and most ceconomical way of obtaining theine from Paraguay tea is by sublimation. The filtered infusion of the tea, after being treated with acetate of lead and the precipitate removed, should be boiled with an excess of litharge, the clear liquid evaporated to dryness and sublimed with the usual precau* tions. One quantity of two pounds yielded 1 2*5 grs. of anhy- drous theine, and a second quantity of equal amount, which was more successfully treated, gave 14-5 grs. = 0-13 per cent. This is about half the quantity which most kinds of coffee yield, which I have found to vary from 12 to 18 grs. for a pound, and about ten times less than Chinese tea, a pound of which yields from 70 to 90 grs. * The portion of this paper read May 2, begins here. Phil. Mag. S. 3. Vol. 23. No. 154. Dec. 1843. 2 F 434 Dr. Stenhouse on Theine and its Preparation. Analysis of Theine from Paraguay Tea. I. 0-2095 gr. of the substance dried at 212° gave 0*525 carbonic acid and 0*134 water. II. 0-3192 gr. gave 0*572 carbonic acid and 0-1487 water. "When burnt with oxide of copper, nine tubes gave carbonic acid and nitrogen in the proportion of four to one. Found. I. II. At. Calculated numbers Carbon 49-960 49-54 16 Carbon =49-798 Hydrogen 5*145 5*17 10 Hydrogen = 5-082 Nitrogen 28-927 28*68 2 Nitrogen =28*832 Oxygen 15-968 16-61 4 Oxygen =16*288 100-000 100-00 100*000 The following is a more complete analysis of the double salt of muriate of theine and chloride of platinum : — I. 0*4637 salt gave 0*412 carbonic acid and 0*1155 water. II. 0*4347 gave 0*386 carbonic acid and 0-1184 water. I. 0-461 salt gave 0-112 plat. = 24*29 per cent. II. 0*529 salt gave 0*130 plat. = 24*57. III. 0*5828 salt gave 0*143 plat. = 24*53. IV. 0*458 salt gave 0*112 plat. = 24*45. I. II. At. Calculated numbers per cent. C 24*56 24*55 16 C = 1222*9 24*32 H 2*76 3*02 11 H= 137*2 2*72 4 N= 708*1 14*08 4 O = 400*0 7*96 3 C\ — 1327*9 26*41 Pt 24*46 24*46 Pt 1233*2 24*51 5029*3 100*00 The rational formula for the salt is C16 Hn N4 04 CI H + Pt 2 CI. The formula for Theine,- 16 Carbon =1222*96 11 Hydrogen = 124*79 4 Nitrogen = 708*16 4 Oxygen = 400-00 Atomic weight= 2455*91 NitrO't/ieine. I have given the provisional name of nitro-theine to the substance crystallizing in large shining plates, produced by the long-continued action of an excess of boiling nitric acid upon theine. It is not necessary to employ fuming nitric acid to obtain this substance, acid of the ordinary strength answers equally well. Nitro-theine when crystallized out of water forms large shining plates resembling cetine, but having more Mr. Joule on the Mechanical Value of Heat. 435 of a pearly lustre. When sublimed, its crystals resemble those of naphthaline, and when formed by spontaneous evapo- ration from aether they are deposited in large, very regular rhombohedrons. I formerly stated that alkalies do not evolve ammonia from nitro-theine; I find that in this I was mistaken, for when boiled with solution of potash it gives off abundance of ammonia. When subjected to analysis, — I. 0*2628 gr. of the substance dried at 212° gave 0*398 carbonic acid and 0*1005 of the water. II. 0*2529 gr. gave 0*3855 carbonic acid and 0*0975 water. When burnt with oxide of copper, ten tubes gave carbonic acid and nitrogen in the proportion of five to one. I. II. Carbon 41*87 42*15 Hydrogen 4*24 4*28 Nitrogen 19*39 19*56 Oxygen 34*50 34*01 100*00 100*00 Nitro-theine appears to be a neutral body, and as I have not been able to determine its atomic weight, I have not thought it worth while to attempt to deduce any formula from these analyses. Theine does not yield more of this substance than from 5 to 6 per cent. LI I. On the Calorific Effects of Magneto-Electricity r, and on the Mechanical Value of Heat. By J. P. Joule, Esq. [Continued from p. 355 and concluded.] Part II. — On the Mechanical Value of Heat. TTAVING proved that heat is generated by the magneto- *■* electrical machine, and that by means of the inductive power of magnetism we can destroy or increase at pleasure the heat due to chemical changes, it became an object of great in- terest to inquire whether a constant ratio existed between it and the mechanical power gained or lost. For this purpose it was only necessary to repeat some of the previous experiments, and to ascertain, at the same time, the mechanical force ne- cessary in order to turn the apparatus. To accomplish the latter purpose, I resorted to a very simple device, yet one peculiarly free from error. The axle b, fig. 1, (p. 264) was wound with a double strand of fine twine, and the strings (as represented in fig. 8) were carried over very easily- working pullies, placed on opposite sides of the axle, at a di- stance from each other of about 30 yards. By means of weights placed in the scales attached to the ends of the strings, 1 could 2 F2 436 Mr. Joule on the Calorific Effects of Magneto-Electricity > easily ascertain the force necessary to move the apparatus at any given velocity ; for, having given in the first instance the re- quired velocity with the hand, it was easily observed, in the course of about 40 revolutions of the axle, corresponding to Fig. 8. r about 270 revolutions of the revolving piece,whether the weights placed in the scales were just able to maintain that velocity. The experiments selected for repetition first were those of series No. 2. Ten cells, in a series of five double pairs, were connected with the large electro-magnet ; and the small com- pound electro-magnet (restored to its place in the centre of the revolving tube) was connected, through the commutator, with the galvanometer. Under these circumstances a velocity of 600 revolutions per minute was found to produce a steady deflection of the needle to 24° 15', indicating 0*983 of current magneto-electricity. To maintain the velocity of 600 per minute, 5 lbs. 3 oz. had to be placed in each scale; but when the battery was thrown out of communication with the electro-magnet, and the motion was opposed solely by friction and the resistance of the air, only 2 lbs. 13 oz. were required for the same purpose. The difference, 2 lbs. 6 oz., represents the force spent during the connexion of the battery with the electro-magnet in over- coming magnetic attractions and repulsions. The perpendi- cular descent of the weights was at the rate of 517 feet per 15 minutes. According to series No. 2, Table I., the heat due to 0*983 (983\2 ) X 10,56 = 1°*85. But as the resistance of the coil of the revolving electro-mag- net was to that of the whole circuit as 1 : 1*13, the heat evolved by the whole conducting circuit was 1°*85 x 1*13 = 2o,09. Adding to this 0°*33 on account of the heat evolved by the iron of the revolving electro-magnet, and 0o,04 on ac- and on the Mechanical Value of Heat. 437 count of the sparks* at the commutator, we have a total of 2°*46. Now in order to refer this to the capacity of a lb. of water, I found — lbs. lbs. Weight of glass tube = 1*65 ss capacity for heat of 0*300 of water. Weight of water = 0-61= 0610 Weight of electro-magnet = 1-67 = ... ... 0-204 Total weight ... = 3-93= T\\i ... 2°*46 x 1*114 = 2°*74; and this has been obtained by the power which can raise 4 lbs. 12 oz. to the perpendicular height of 517 feet. 1° of heat per lb. of water is therefore equivalent to a me- chanical force capable of raising a weight of 896 lbs. to the perpendicular height of one foot. Two other experiments, conducted precisely in the same manner, gave a degree of heat to mechanical forces repre- sented respectively by 1001 lbs. and 1040 lbs. I now made an experiment similar to those of series No. 10. Eight cells in a series of four double pairs were connected with the large electro-magnet, and two in series with the small re- volving electro-magnet. The velocity of revolution was at the rate of 640 per minute, contrary to the direction of the attrac- tive forces, causing the needle to be deflected to 37° 20', which indicates a current of 1*955. A weight of 6 lbs. 4 oz. placed in each scale was just able to maintain the above velocity when the circuits were com- plete ; but when they were broken, and friction alone opposed the motion, a weight of 2 lbs. 8 oz. only was required, which is less than the former by 3 lbs. 12 oz. The fall of the weights was in this instance 551 feet per 15 minutes. According to series 10, Table II., the heat due to the cur- (T955\2 ■ ) x 50,88 = 6°'6. But I had found by calculations, based as usual upon the laws of Ohm, that, in the present experiment, the resistance of the coil of the revolving electro-magnet was to that of the whole circuit, including the two cells, as 1 : 1*303. Therefore the heat evolved by the whole circuit, including 0°*18 on account of the iron of the revolving electro-magnet, and 0°*12 on account of sparks at the commutator, was 8°*9, or 9°*92 per capacity of a lb. of water. Now when the revolving electro-magnet was stationary, the two cells could pass through it an uniform current of 1*483. * The heat evolved by sparks in the above and subsequent instances had been determined by previous experiments. 438 Mr. Joule on the Calorific Effects of Magneto-Electricity, The heat evolved from the whole circuit by such a current is /1*483\2 \!Fl45/ X 5°'88 * 1,3°3 X 1,114j = 4,°,°8 per lb# of water per 15 minutes, according to data previously given. Hence the quantity of heat due to the chemical reactions in the ex- 1*955 periment is x 4°*08 = 5°*38, instead of 9°*92, the quan- tity actually evolved. Hence 4° 54' were evolved in the experiment over and above the heat due to the chemical changes taking place in the bat- tery, by the agency of a mechanical power capable of raising 7 lbs. 8 oz. to the height of 55 1 feet. In other words, one de- gree is equivalent to 910 lbs. raised to the height of one foot. An experiment was now made, using the same apparatus as an electro-magnetic engine. The power of the magnetic at- tractions and repulsions alone, without the assistance of any weights, was able to maintain a velocity of 320 revolutions per minute. But when the circuits were broken, a weight of 1 lb. 2 oz. had to be placed in each scale in order to obtain the same velocity. The deflection of the needle was in this in- stance 17° 15' = 0*63 of current electricity. The perpen- dicular descent of the weights was 275 feet per 15 minutes. Now, calculating in a similar manner to that adopted in the last experiment, we have, from series 9, Table II., and other (630\2 — ) X 0°*50 x 1*303 = 0°*877, which, on applying a correction of 0°*012 on account of sparks at the commutator, and 0o,18 on account of the iron of the revolving electro-magnet, and then reducing to the capacity of a pound of water, gives 1°#191 as the quantity of heat evolved by the whole circuit in 15 minutes. The quantity of current which the two cells could pass through the revolving electro-magnet when the latter was /1'538\2 stationary, was in this instance 1*538 ; and f j x 5°*88 x 1*303 x 1*114 = 4°*38. Hence, as before, the quantity of heat due to the chemical reactions during the experiment is ^f- x 4°*38 = 1°*794, which is 0°*603 more than was ob- 1*538 tained during the revolution of the electro-magnet. Hence 0°*603 has been converted into a mechanical power equal to raise 2 lbs. 4 oz. to the height of 275 feet. In other words, one degree per lb. of water may be converted into the mechanical power which can raise 1026 lbs. to the height of one foot. and on the Mechanical Value of Heat. 439 Another experiment, conducted in precisely the same man- ner as the above, gave, per degree of heat, a mechanical power capable of raising 587 lbs. to the height of one foot. As the preceding experiments are somewhat complicated, and therefore subject to the accumulation of small errors of observation, I thought it would be desirable to execute some of a more simple character. For this purpose I determined upon an arrangement in which the whole of the heat would be evolved in the revolving tube. The iron cylinder used in previous experiments was placed in an electrotype apparatus constructed in such a manner as to render every part of it equally exposed to the voltaic action. In four days 1 1 oz. of copper were deposited in a hard com- pact stratum. The ends of the cylinder were then filed until the iron just appeared. Thus I had a cylinder of iron imme- diately surrounded by a hollow cylinder of pure copper nearly one-eighth of an inch thick. This was placed in the centre of a new revolving tube fitted up in precisely the same manner as the former one, which had been accidentally broken, and sur- rounded with 11^ oz. of water. I give the following series of experiments in which the above was rotated between the poles of the large electro-magnet excited by ten cells arranged in a series of five double pairs, a galvanometer being included in the circuit to indicate the electric force to which the electro- magnet was exposed. No. 16. Revolu- tions of the Bar per nunute. Deflec- tions of Galvano- meter of 1 turn. Mean Tempe- rature of Room. Mean Differ- ence. Temperature of Water. Gain or Loss. Before. After. Battery con- tact broken. Igoo o 1 67°50 0°15- 67°37 67°33 00°4 loss *l Electro-mag- net in action. j-600 72 35 69-32 0«42— 67-50 70-30 280 gain * r S 1 l Battery con- tact broken. J600 ... 68-80 016+ 6900 68-93 0-07 loss Electro-mag- net in action. J600 72 25 69-70 0-56+ 69-00 71-52 2-52 gain Mean, Electro-mag- 1600 72 30 0-07+ 2*66 gain net in action. J Mean, Battery con- tact broken. Uoo ... ... ... ... ... 005 loss Corrected Result. J600 72' 30' = 1 093 current. 273 gain 440 Mr. Joule on the Calorific Effects of Magneto-Electricity, I now proceeded to ascertain, by means already described, the mechanical power by which the above effects were pro- duced. First, I ascertained the current passing through the coil of the electro-magnet ; then the weights necessary to maintain the velocity of 600 revolutions per minute, both when the magnet was in action and when contact with the battery was broken. I have collected the results of my expe- riments on this subject in the following table. The first five were obtained with a battery of ten cells in a series of five ; the last two with a battery of five pairs in series. Table IV. Deflections of the Weight in each Weight in each Galvanometer of one scale, the scale, the turn completing the Electro- Magnet Electro-Magnet Difference. circuit of the being being Electro-Magnet. in action. not in action. o / lb. oz. lb. oz. lb. oz. 72 30 4 4 2 5 1 15 72 30 4 4 2 3 2 1 72 25 4 2 2 0 2 2 72 15 5 0 2 10 2 6 72 5 4 0 2 0 2 0 68 0 3 14 2 8 1 6 66 10 3 0 2 0 1 0 Mean of the first J72° 21' = 10- 82 current. 2-1 lbs. 5 experiments Mean of the last J67° 5' = 7*91 current. 1-19 lb. 2 experiments Referring to series 16, we see that 20,73 were obtained when the bar was revolved between the poles of the electro-magnet excited by a current of 10*93. Therefore the quantity of heat due to the mean current in the first five experiments of the •82\2 above table is /io_ \10 9 .'5 ) x 2°-73 = 2°-675. To reduce this to the capacity of a pound of water, I had in the present in- stance the following data : — lbs. ' lb. Weight of glass tube . = 1*125 = capacity for heat of 0-205 of water. Weight of water . .=0-687= 0-687 ... Weight of metallic bar = 1-688 = 0202 ... Total Weight = 3-500 = 1094 ... 2%926, the product of 1-094 and 2°*675, is therefore the heat generated by a mechanical force capable of raising 4'2 lbs. to the height of 517 feet. and on the Mechanical Value of Heat. 441 In other words, one degree of heat per lb. of water may be generated by the expenditure of a mechanical power capable of raising 742 lbs. to the height of one foot. By a similar calculation, I find the result of the last two ex- periments of the table to be 860 lbs. The foregoing are all the experiments I have hitherto made on the mechanical value of heat. I admit that there is a con- siderable difference between some of the results, but not, I think, greater than may be referred with propriety to mere errors of experiment. I intend to repeat the experiments with a more powerful and more delicate apparatus. At present we shall adopt the mean result of the thirteen experiments given in this paper, and state generally that, — The quantity of heat capable of increasing the temperature of a pound of water by one degree of Fahrenheit* s scale is equal to, and may be converted into, a mechanical force capable of raising 838 lbs. to the perpendicular height of one foot. Among the practical conclusions which may be drawn from the convertibility of heat and mechanical power into one an- other, according to the above absolute numerical relations, I will content myself with selecting two of the more important. The former of these is in reference to the duty of steam-en- gines ; the latter, to the practicability of employing electro- magnetism as an ceconomical motive force. 1 . In his excellent treatise on the Steam-engine, Mr. Rus- sell has given a statistical table*, containing, among other im- portant matter, the number of pounds of fuel evaporating one cubic foot of water, from the initial temperature of the water, and likewise from the temperature of 212°. From these facts it appears that in the Cornish boilers at Huel Towan, and the United Mines, the combustion of a lb. of Welsh coal gives 183° to a cubic foot of water, or otherwise 11,437° to a lb. of water. But we have shown that one degree is equal to 838 lbs. raised to the height of one foot. Therefore the heat evolved by the combustion of a lb. of coal is equivalent to the mechanical force capable of raising 9,584,206 lbs. to the height of one foot, or to about ten times the duty of the best Cornish engines. 2. From my own experiments, I find that a lb. of zinc con- sumed in Daniell's battery produces a current evolving about 1320°; in Grove's battery, about 2200° per lb. of water. Therefore the mechanical forces of the chemical affinities which produce the voltaic currents in these arrangements, are, per lb. of zinc, equal respectively to 1,106,160 lbs. and 1,843,600 lbs. raised to the height of one foot. But since it will be practically impossible to convert more than about one half of the heat of * Enc. Brit., 7th Edition, vol, xx. part 2. p. 685. 442 Mr. Joule on the Mechanical Value of Heat. the voltaic circuit into useful mechanical power, it is evident that the electro-magnetic engine, worked by the voltaic bat- teries at present used, will never supersede steam in an ceco- nomical point of view. Broom Hill, Pendlebury, near Manchester, July 1843. P.S. — We shall be obliged, after all, to admit that Count Rumford was right in attributing the heat evolved by boring cannon to friction, and not (in any considerable degree) to any change in the capacity of the metal. I have myself proved experimentally that heat is evofoed by the passage of water through narrow tubes. My apparatus consisted of a piston perforated by a number of small holes, working in a cylindrical glass jar containing about 7 lbs. of water. I thus obtained one degree of heat per lb. of water from a mechanical force capable of raising about 770 lbs. to the height of one foot, — a result which will be allowed to be very strongly confirma- tory of our previous deductions. I shall lose no time in re- peating and extending these experiments, being satisfied that the grand agents of nature are, by the Creator's fiat, inde- structible', and that wherever mechanical force is expended, an exact equivalent of heat is always obtained. On conversing a few days ago with my friend Mr. John Davies, he told me that he had himself, a few years ago, at- tempted to account for that part of animal heat which Craw- ford's theory had left unexplained, by the friction of the blood in the veins and arteries, but that, finding a similar hypothesis in Haller's 'Physiology*,' he had not pursued the subject further. It is unquestionable that heat is produced by such friction, but it must be understood that the mechanical force expended in the friction is a part of the force of affinity which causes the venous blood to unite with oxygen ; so that the whole heat of the system must still be referred to the chemical changes. But if the animal were engaged in turning a piece of machinery, or in ascending a mountain, I apprehend that in proportion to the muscular effort put forth for the purpose, a diminution of the heat evolved in the system by a given chemical action would be experienced. I will observe in conclusion, that the experiments detailed in the present paper do not militate against, though they certainly somewhat modify the views I had previously entertained with respect to the electrical origin of chemical heat. I had before endeavoured to prove that when two atoms combine together, the heat evolved is exactly that which would have been evolved by the electrical current due to the chemical action taking place, and is therefore proportional to the intensity of the * Haller's Physiology, vol. ii. p. 304. Mr. Grove on Voltaic Reaction. 443 chemical force causing the atoms to combine. I now venture to state more explicitly, that it is not precisely the attraction of affinity, but rather the mechanical force expended by the atoms in falling towards one another, which determines the intensity of the current, and consequently the quantity of heat evolved ; so that we have a simple hypothesis by which we may explain why heat is evolved so freely in the combination of gases, and by which indeed we may account "latent heat" as a mecha- nical power prepared for action as a watch spring is when wound up. Suppose, for the sake of illustration, that 8 lbs. of oxygen and 1 lb. of hydrogen were presented to one another in the gaseous state, and then exploded, the heat evolved would be about one degree Fahr. in 60,000 lbs. of water, indicating a mechanical force expended in the combination equal to a weight of about 50,000,000 of lbs. raised to the height of one foot. Now if the oxygen and hydrogen could be presented to each other in a liquid state, the heat of combination would be less than before, because the atoms, in combining, would fall through less space. The hypothesis is, I confess, suffici- ently crude at present, but I conceive that ultimately we shall be able to represent the whole phaenomena of chemistry by exact numerical expressions, so as to be enabled to predict the existence and properties of new compounds. August, 1843. J. P. J. LIU. Experiments on Voltaic Reaction. By W. R. Grove, Esq., M.A., F.R.S., Prof essor of Experimental Philosophy in the London Institution*. f~\ N the weekly evening meeting of the Royal Institution for ^-** March 13, 1840t5 1 communicated some experiments and observations on certain phaenomena which I collated under the general term Voltaic Reaction. I then stated, that in cer- tain (probably in all) cases of the development of a voltaic cur- rent a reaction was induced by the voltaic force itself, and that upon the cessation of the initial force the reacting force was apparent in an opposed direction. I showed, moreover, that the diminution or removal of this reaction was one means of increasing the power of the initial current. This reaction in electrolytes (though it is by no means confined to electrolytes) is what has been generally called polarization, and would be one of the resistances to be taken into account in calculating the resulting power of a voltaic current upon Ohm's theory. It recently occurred to me, that as one method of increasing the power of the initial current was to diminish (or, as it were, * Communicated by the Author. f A report is published in the Phil. Mag., S. 3., vol. xvi. p. 338. 444 Mr. Grove on Voltaic Reaction. Fig. 1. Fig. 2. absorb) this reaction, so another method of effecting the same object would be, to add the reacting to the initial force, which, from the separable character of the former, did not appear impracticable. After sundry devices the following experi- ments realized my views on this subject. Experiment 1. fig. 1. — db is a single cell of the nitric acid battery, exposing six square inches of each metal ; v is an ordinary voltameter, each electrode exposing half a square inch, charged with dilute sulphuric acid ; decomposition was allowed to proceed with this ar- rangement for six hours; the bat- tery, for greater assurance of con- stancy, being in this and the two following experiments recharged every two hours; the level of the liquid in the voltameter was carefully marked on the tube. Experiment 2. fig. 2. is the same nitric acid battery, d b the same volta- meter Vf but with an interposed pair of large platinum plates, a c, expo- sing each to each forty- two square inches of surface, and immersed in dilute sulphuric acid ; this arrange- ment was also set to work for six hours. A slight evolution of gas had taken place in the volta- meter in this expe- riment, and the water-level was also marked. Experiment 3. — The same appara- tus as fig. 2 ; but my assistant was di- rected to change at Mr. Grove on Voltaic Reaction. 445 a certain interval the wires clipping into the mercury cups gg', so as to reverse the plates a c, with regard to the direction of the current, making what was the anode the cathode, and vice versa, as shown by the dotted lines ; and at the expiration of a similar interval to restore them to their original positions, and to continue thus alternating the position of these plates with reference to the current during six hours. The interval was to be dependent upon the following ob- servation : — When first the circuit was completed, a marked evolution of gas was perceptible in the voltameter, this gradu- ally subsided, and when it had become nearly imperceptible the change was to be made, when a fresh burst of gas took place, as this again subsided the wires were to be again changed, and so on. At the expiration of six hours the water- level was marked, as in the previous experiments. The following is the quantity of gas evolved in the volta- meter, deduced from a mean of several experiments : — cubic inch. Experiment 1. = 0*15 Experiment 2. = 0*10 Experiment 3. = 0*23. In neither of the last two experiments was a bubble of gas perceptible on the large plates a c. It appears from these experiments, that the nitric acid bat- tery will decompose water across two pairs of interposed in- oxidable electrodes, provided one be of considerable size with reference to the other parts of the circuit, so as to lessen re- sistance. Whether this diminished resistance be occasioned by the mere increase of the sectional area of the electrolyte; whether by the increased facility for solution of the oxygen and hydro- gen ; whether the oxygen and hydrogen be not eliminated, but merely thrown into a state of polar tension, or made to adhere in a liquid or gaseous form to the plates; or whether any of these effects take place conjointly, I will not stop to inquire, but proceed to the more remarkable fact, viz. that the quan- tity of gas evolved in Experiment 3. is greater for a given time, not only than that evolved in Experiment 2, but even than that evolved in Experiment I ; thus we get the seeming paradox, that a battery performs more work with an inter- posed resistance than without it. While the battery is decomposing water in the voltameter v, it is polarizing the plates a c, or accumulating by its own force an antagonist force ; when the wires are changed this reacting force is united in direction with the initial force, in fact two voltaic pairs are constituted. The reaction being ex- 44-6 Indications of the Barometer and Thermometer hausted, a new polarization commences, to be added in its turn to the initial current ; and the reason why we get the increased work at the voltameter is, that 'while the polarization is pro- ceeding at a c water is decomposed in the voltameter, and although this may be somewhat less than the battery would produce without the interposed plates a c, still this deficiencv is more than made up by the action of the double pair at each alternation of the wires. If the view I have taken be correct, as reaction can never be greater than the action which occa- sions it, we should never get, in Experiment 3, beyond the quantity of gas given by two pairs of the battery d b, but we may indefinitely approach that maximum. A commutator might be easily arranged instead of the hand for effecting the alternation at the proper periods, which, by a little contrivance, may be made to work by the battery itself, but I prefer stating the experiment in its most simple form and free from mechanical complication. Although the experiment as here described is merely in il- lustration of a principle, it appears to me to promise results of some practical value; the ceconomy of this method of apply- ing force is evident, we get all but a double product with a single consumption; the principle in all probability is not con- fined to the voltaic force, but may perhaps be applied to mechanics. LIV. Occasional 'Notes on Indications of the Barometer and Thermometer during Stormy Weather at Belfast) from No- vember 1833 to January 1843. By the Rev. William Bruce*. 1833. Nov. 28 /~)NE of the severest storms that had been and 29. ^~* recollected. Wind began at about south- east, changed during night to north-west or west-north-west with tremendous rain. Barometer rose from 5 o'clock p.m. of November 28, full one inch and a half in thirty-six hours, having previously fallen with great rapidity, but the quantity not noted. By the Library Barometer there was a rise of 1*37 in forty-five hours, viz. from 2 o'clock p.m. on November 28 to 11 o'clock a.m. on November 30, but no account could there be taken of the additional fall from 2 o'clock to 5 o'clock, when the rise began. 1 834-. Nov. 5. — Barometer continued fallingduring the whole day till 1 1 o'clock p.m. On the morning of the 6th it had risen about four-tenths, and continued to rise till 11 o'clock p.m. (a beautiful day) ; on the morning of the 7th it had fallen nearly * Communicated by the Author. during Stormy Weather at Belfast from 1833 to 1843. 447 half an inch, with a tremendous storm of wind and rain, and continued falling till night; on the morning of the 8th it had risen three-tenths, and continued rising until night, when it was up half an inch higher than the preceding night, and so continued rising for several days. 1835. Jan. 17. — Thermometer exposed with northern aspect, stood at 20° at 10 o'clock p.m. Jan. 20. — Thermometer exposed with northern aspect, stood at 24° at 9 o'clock p.m. Jan. 23. — Thermometer exposed with northern aspect, stood at 48° at 10 o'clock p.m. Jan. 25. — Thermometer exposed with northern aspect, stood at 51° at 9 o'clock p.m. Feb. 1. — Thermometer exposed with northern aspect, stood at 56° at 4 o'clock p.m. 1836. Dec— Between 10^ o'clock p.m. of the 13th, and 10£ o'clock p.m. of the 14th, the barometer rose from 29° to 30°, one inch in twenty-four hours. 1839. Jan. 6. — Storm began about lOf o'clock ; barometer falling rapidly for some time before. It fell to 28*15 before 1 o'clock of the morning of the 7th, between which hour and 7§ o'clock a.m. it had risen to 28*62. Thermometer had stood at 31° at 9 o'clock a.m. of the 6th, and rose to 50° at 10 o'clock p.m. of the same day. I calculated that it fell one inch and then rose half an inch in twelve hours' time. At 9^ o'clock a.m. of the 7th, barometer stood at 28*75; at 10^ o'clock a.m. of the 7th, barometer stood at 28*81. Began to fall again at 1 1^ o'clock a.m; at 1 \ o'clock at 28*90 ; at 4 o'clock p.m. stood at 29*05. On Tuesday morning, the 8th inst., at 71 a.m., the baro- meter stood at 29*60, being a rise of \\ inch from Monday morning at 1 o'clock a.m. to Tuesday at 7 o'clock a.m. = thirty hours. Feb. 1. — At 1\ o'clock a.m., thermometer stood at 21°. Feb. 8. — At 8 o'clock p.m., thermometer stood at 54°, with a very high wind. Feb. 13. — At night and morning of 14th, barometer 29*85; thermometer 44°. At 1 1 o'clock p.m., in five hours after, viz. at 4 o'clock a.m., barometer 29*55; thermometer 51°. At 7 o'clock a.m. of the 14th, barometer 29*60 ; thermometer 47°. At 9 o'clock a.m., barometer 29*70. On the 15th and 16th a storm of snow and wind. 1840. Jan. 18. — From 11 o'clock p.m. to Jan. 19, at same hour, the range of the barometer was about eight-tenths of an inch, being a fall of five-tenths and a rise of three-tenths, with a gale of wind and severe showers. 448 Indications of the Barometer and Thermometer Jan. 26. — From 4 o'clock p.m. to 27th, at same hour, a range of fully eight-tenths' rise, with high winds and showers of sleet and snow. Oct. 18. — Barometer fell more than four-tenths. On the 19th, at 7 o'clock a.m., it had risen more than two-tenths; between this and 11 o'clock a.m., it had fallen again about a quarter of an inch, and between 1 1 and 1 2| o'clock it rose nearly as much. Wind very high from west-south-west to north-west. Nov. 12. — At night, and morning of the 13th (Thursday and Friday), there was a severe gale of wind with tremendous rain from north-east. South coast of England had the same storm from south-west. ' Nov. 15th (Sunday). — At night very heavy rain, and on Monday night (16th), a very severe gale of wind from south- west to west. Rise of barometer seven-tenths. Nov. 20 and 21 (Friday and Saturday). — On night of 20th and morning of 21st, tremendous rain, with a gale of wind veering from south-west to west. Fall of barometer more than five-tenths in nine hours. The wind had been north to south on Thursday night and Friday morning. Dec. 6 and 7. — A very severe gale of wind, and some rain from south-south-west to west-south-west or west; and on Tuesday preceding a severe gale also. Thermometer at 55° and 50°. 1841. Jan. 3. — On last night and this morning a very se- vere gale in tremendous gusts, beginning at south of west, and passing to west and north-west; thermometer in the course of a very few hours sinking from 44° to 32°. Gale continued all day of the 3rd, and also on the 4th, with a rise of the baro- meter = to about eight-tenths or more in twenty-four hours. Wind on the 4th, north-west and north-north-west. Sky electrical in appearance. On the 8th of January, and several days after, thermometer stood at about 20°. Jan. 16th. — At night a severe gale of wind, beginning early in the evening at east, or south-east, and going round by south to south-west and west-south-west or west. Barometer fell five-tenths in ten hours. March 30. — At night and following morning a very severe gale of wind, beginning at westward of south, and changing to west with tremendous rain. May 1. — Thermometer at 71° in the shade, north aspect, at 3 o'clock p.m.; on the next day, at same hour, 48°; differ- ence 23 degrees. Oct. 17. — At night and following morning a severe gale, beginningat south or south-south-westandendingat north-west. during Stormy Weather at Belfast from 1833 to 1843. 449 Barometer rose between 10£ o'clock at night and 7£ o'clock next morning (nine hours) from 28'95 to 2975 = eight-tenths; it had been falling pretty rapidly for some time before. Dec. 5. — Last night a gale of wind with rain from northward of west. Barometer rose about 1 inch in twenty-four hours. Dec. 6. — Another gale with heavy rain. Barometer y^// half an inch in twenty-four hours. Dec. 12. — A severe gale early this morning. Barometer fell four-tenths in nine hours, and thermometer rose from 40° to 50° in the course of the night. Dec. 14. — A gale last night from north-west. Barometer had fallen yesterday morning about three-tenths; between 4 and 5 o'clock it began to rise, and had risen eight-tenths at 8 o'clock this morning. Dec. 15. — Another gale last night with heavy showers. Wind south-west. Barometer fell more than four-tenths in the night. Dec. 19. — Thermometer last night at 10| o'clock stood at 19°, next morning at 8 o'clock at 28°. 1842. Jan. 25. — This night, and the morning of the 26th, a remarkably severe gale of wind with tremendous rain, parti- cularly between 5 o'clock and 7 o'clock. The barometer fell nine-tenths of an inch in nine hours, viz. from 1 1 o'clock p.m. to 8 o'clock a.m.; at 11 o'clock it stood at 29*7, and at 8 o'clock it was at 28'8, still falling. Wind south, veering to south-west and back. In the evening of the 26th, about 3 o'clock, the barometer began to rise, and for some hours rose at the rate of one-tenth per hour, with the wind north-north- west and a severe gale of wind and rain. Feb. 27. — About 4 o'clock a.m. a very severe gale of wind with heavy rain. On the preceding day the barometer was rising till 10 o'clock p.m., when I last observed it. At 8 o'clock on the following morning it had fallen five-tenths, viz. in ten hours. Heavy squalls" all day on Sunday; worst part of the storm nearly due west, sometimes west-south-west. Oct. 22. — A severe gale last night ; barometer fell half an inch in nine hours. Dec. 1 5. — Last evening a heavy gale of wind from south-west or west-south-west ; no remarkable fall of the barometer, but the heat unnatural; thermometer being 54°, succeeded by a fall of rain without any wind during the whole of this day and night. Dec. 22. — Last night and this morning a gale of wind at south-west ; barometer fell one quarter of an inch ; ther- mometer at 8 o'clock a.m. 50°. Dec. 26. — Last night a gale; wind west-south-west to west; fall in barometer about two-tenths, or two and a half; ther- mometer 48° at night, 45° in the morning. Phil. Mag. S. 3. Vol. 23. No. 154. Dec. 1843. 2 G 450 Professor Young's New Criteria Dec. 29. — Last night a gale, continuing in the morning; wind west-south-west. The fall in the barometer at the com- mencement was not more than one-tenth of an inch, and du- ring the night it did not fall at all, standing during the gale at 29*9. Thermometer yesterday morning at 34°, with a hard frost on the ground, which lasted till 11 o'clock a.m. At 10 o'clock p.m. thermometer was 48° (a difference of 14°), and this morning at 50°. Dec. 30. — Last night, but more particularly from 3 o'clock this morning, very heavy gusts of wind nearly west, without any rise or fall in barometer worth notice ; but the tempera- ture at night was 50°, and at half-past 7 o'clock this morning 52°. About half-past 6 o'clock in the morning I thought I saw patches or gleams of electric light along the grass. Gale continued throughout the day, barometer rising very slowly. Dec. 31. — Same storm continued all last night, with ther- mometer at 54° at half-past 10 o'clock p.m., and at 56° at 8 o'clock this morning; barometer did not vary more than half a tenth, standing still at 30°. A drizzling rain and damp at- mosphere so much illuminated that 1 could see my watch at any hour, though there were no stars and the moon at the change. I observe in the papers an account of a very ex- traordinary thunderstorm, doing much damage to houses and cattle at Ballyshannon, on Friday the 30th. In the evening of the 31st it became calm and the air cooler; weather continued very fine for two or three days. 1843. Jan. 13. — Last night barometer fell seven-tenths of an inch between 11 o'clock p.m. and 8 o'clock this morning (nine hours), when it was lower than I had almost ever seen it, except in Jan. 1839. A very heavy squall of wind and rain during the night, wind veering from south-east to south or south-west. Morning calm, but showers of snow during the day, and from 8 o'clock p.m. the wind began to blow a gale. I have heard from Dublin that the barometer was so low as 27'9, and I see in our own papers notices of an extraordinary state of the tides. LV. New Criteria for the Imaginary Roots of Numerical Equations. By J. R. Young, Professor of Mathematics in Belfast College*. IN a former Number of this Journal, and with fuller detail in a more recent publication f5 I have discussed some useful formulae for discovering imaginary roots in an equation from inspecting the coefficients of its terms. The new forms * Communicated by the Author. t Researches respecting the Imaginary Roots of Equations. for the Imaginary Roots of Numerical Equations. 451 proposed in the present paper will, I think, prove an accept- able addition to those previously given: they are not only of greater simplicity, but will often succeed in detecting the pre- sence of imaginary roots in cases where Newton's formulae — the basis of those adverted to above — would prove inefficient. These new forms are deduced as follows: — Let the equation A„*"+A„_1*"-1 + A„_2*-2 + A„_3.*»-3 + ...A,* + A0=0 be multiplied by x — «, that is, let a new undetermined real root a be introduced into the equation : whatever imaginary roots are indicated in the new equation, the same of course enter into the original. This new equation is Aw^+1 + (Aw_1-aAJ," + (Ara_2-«Aw_1)^-1 + (AM_3-flAM_2)/-2+...(Ao-flA1)a? + aA0 = O, in which a is entirely arbitrary, and may therefore be made to satisfy any condition we please. It may for instance be de- termined so as to render any one of these compound coeffi- cients zero; and if, in conjunction with this determination of a, the original coefficients be so related as to cause the com- pound coefficients on each side of this zero to be of like signs, we shall at once recognise the presence of imaginary roots in the proposed equation. Equating then the several coefficients to zero, one after the other, commencing with the second, and determining the ad- jacent pair of coefficients in each case conformably to this condition, we shall have the following sets of conditions, the existence of any one of which will imply a pair of imaginary roots : — An=+, A^-aA^O, A2„-l-A„Aw-2 = +> An-2-aAn-l = °> A2«-2-A„-lA„-2=+> An-3-«AM-2 = °> &c. &c. And therefore, a being always assumed so as to satisfy one of the middle equations, those on each side will furnish the following series of criteria of imaginary roots, viz. — A„=+, A,A,.!>A',.1...[1.] *\-2>K-iA«-V A„-2A„_4^A\_3... [3.] &c. &c 2 G2 A„ A„_2 — A2„-l = + , A„. -A- -3~ "A2n-2 = + , A„. -2A„- 4~ -A2« i- n — 6 &C. + , 452 Notices respecting New Books. Now assuming, according to custom, that An is always plus, it is plain, that if any one of the right-hand conditions have place, without regarding those on the left, a pair of imaginary roots will necessarily be indicated ; because, although the ac- companying left-hand condition should not have place, yet, by ascending to the preceding pair of conditions, and thence to that next in order, and so on, we should evidently at length arrive at a co-existent pair. It is equally evident that no two consecutive pairs can exist simultaneously, since the second condition in any one pair is opposed to the first in the pair next following. Hence, although all the right-hand condi- tions marked [I.], [2.], [3.], &c. were found to have place, yet only one pair of imaginary roots could be inferred : these con- ditions, therefore, can be regarded only as so many concurrent indications of the same thing. Whenever this concurrence ceases, by a failure of one of the right-hand conditions referred to, or which is the same thing, by a fulfilment of the left-hand condition next in order, then preparation is made for a new indication, totally distinct from those that have preceded ; and if such new indication offer itself, a distinct pair of imaginary roots may be inferred. Hence the series of conditions [1.], [2.], [3.],&c. furnish us with criteria of imaginary roots somewhat analogous to those of Newton ; much simpler, however, in form, but to be em- ployed exactly in the same manner. I shall give two examples of this application : — 1st. 5x8 — 2x7 + Sx6 — 24.r5 — 16x4 + a3— 4#2 — 2d? — 60 = 0. Applying the criteria to this equation, we discover the exist- ence of six imaginary roots ; the same as by the rule of New- ton (Researches, &c, p. 47). 2nd. 9 xr> — 5 x4 + 4 x3 — 3 x"2 + 6 x + A0 = 0. In this example Newton's rule detects only a single imaginary pair; the criteria above discover two pair, so that the equa- tion has but one real root. It may be added that, as in the rule of Newton, the sign > may be changed into ==. Belfast, November 7, 1843. J, R. YoUNG. LVI. Notices respecting New Books. 1 . Philosophical Theories and Philosophical Experience. 2. Connection between Physiology and Intellectual Philosophy. 3. On Man's power over himself to prevent or control Insanity. Pick- ering. AT a time like the present, when the general spread of education has put the keys of knowledge into the hands of many, to Notices respecting New Books. 453 whom half a century back they were utterly inaccessible, it ap- pears a strange anomaly that there should be less of serious and deep thought than in the days when little adventitious aid to study of any kind could be obtained ; yet those who have observed most closely, and reflected most deeply, agree in the opinion that such is the case, and that the present age, with all its " appliances and means " of knowledge, may be justly termed superficial. One ob- vious cause of such a state of things, and the only one which it is needful to our present purpose to notice, arises from the immense increase of our population — all struggling for maintenance, or for the good things of this world in some shape — all ashamed not to possess some slight acquaintance with the literature of the day, yet all too much engrossed by the immediate pressure of their daily con- cerns to give more than a passing thought to other matters. Among the many whose cases come under the above description, there must however be a large number who would gladly obtain more solid in- formation on subjects, both of science and general knowledge, than has hitherto been within their grasp ; but how can the evening of a day of toil, or a proper use of the needful and holy rest of Sunday, afford leisure for the study of voluminous writings, even were the demand on their pockets within the means of those who would learn if they could ? The strong conviction of the necessity of furnish- ing persons so situated with the mental nourishment they require in a condensed form, has induced a few friends to unite "for the pur- pose of supplying the deficiency," which, as their prospectus states, " could hardly be supplied in the common course of trade ;" and the three little works, whose names stand at the head of this article, have been already published by the Society. We willingly co-operate in a design so well intentioned, and so likely, we think, to be useful to the world, by introducing them to the notice of our readers, to whom, however, it is very probable that the 2nd and 3rd numbers may be already known, being the substance of two lectures delivered, one in 1841, the other in the spring of this year, at the Royal Institution, by the Rev. John Barlow. In the first treatise, " Philosophical Theories and Philosophical Experience," the ' Pariah ' (as the author chooses to style himself) discourses on those most important of all subjects, the present and future destiny of man ; and shows by a train of lucid reasoning that all true religion and all real philosophy must accord, since eternal truth is One, and admits of no contradictions ; and that the word of God and reason unite in pointing out to man wherein his real good consists. " The questions," says the ' Pariah,' " which have agitated mankind in all ages, and whose solution forms the basis of all sy- stems of religion and philosophy, .... may be resolved into three. " 1. What is the nature of the power exterior to ourselves ? " 2. What is the nature of the power within ourselves ? "3. What, with reference to these two, is the nature of the good which man ought to propose to himself as his aim and object?" (Phil. Theo. and Phil. Ex. pp. 11, 12.) In reply to the first query the author proves, that " by a legitimate 454 Notices respecting New Booh. course of reasoning we arrive at the certainty of one eternal, self- existent, all-wise, and all-powerful Being, whom our simple ances- tors, with a degree of philosophical accuracy which no other nation seems to have reached, named job, i. e. good." (Ibid. p. 19.) He shows that " Christianity goes further," but in strict accordance with those conceptions of the Almighty which the purest philosophy could form ; and that " it sets before man an exemplar of human virtue, made perfect by the indwelling of the Deity." (Ibid. p. 41.) In the solution of the second inquiry the ' Pariah ' classifies "the phenomena of man's nature into " 1. The instinctive emotions and appetites. "2. The faculties. "3. The will." (Ibid. p. 54.) The two former, partaking •* of the changes which the body un- dergoes," are assumed to be " bodily;" but " the individual and in- telligent will," which can control and restrain the emotions and direct the faculties, and also " that species of memory which forms the consciousness of identity, and which (however ordinary recollec- tions may be impaired by the injury or disease of the brain) never suffers any change from infancy to death " (ibid. p. 37), cannot be bodily, and are consequently considered by the ' Pariah ' as " spiritual and unchanging functions." The " practical results " which form the reply to the third query are such as, were they carried out in their full extent (and there is no insurmountable obstacle in the nature of things against it), would render our earth a paradise in comparison with its actual condition. "I have stated," says the Pariah, "that an essential part of the great Self-existent Cause of all things, is a free and governing will. Man there- fore in this bears the image of his Maker; and inasmuch as he partakes in a certain degree of the nature of his Creator, his happiness and his destiny must be of a kind somewhat analogous. The felicity of the Creator (as far as we can judge) must consist in the constant harmony of his nature with his acts. The will to do what is best, and the power to effect it, or, in other words, unbounded knowledge, power and benevolence. Now, though man's finite nature can follow but at humble distance, it can follow. He may act in conformity to his nature; he may delight in conferring happi. ness and in seeking knowledge ; and I believe all who have tried the expe- riment will bear testimony that this course confers even in this life a peace of mind, a joy, even in the midst of the turmoils of the world, which is more akin to heaven than earth." (Ibid, pp. 81, S2-) The great bearings of the second treatise, " On the Connection be- tween Physiology and Intellectual Philosophy," have been given in the lecture on Insanity, and we cannot do better than avail ourselves of a portion of the lecturer's notice of it. He says, "Two years ago I had the honour of submitting to you some views with regard to intellectual science, which appeared necessarily to result from the recent discoveries in anatomy In order to make myself clearly under- stood, it will be necessary to take a brief view of the structure and func- tions of the brain and nerves, as explained in my former communication." The author then gives the usual description of that structure, but Notices respecting New Books. 455 we may turn to the second essay for a summing-up of the whole, sufficient to show the general view of the matter taken by the author. A short account is there given of the arrangement of the nerves, &c, and the different functions they perform. "Thus we have three distinct systems of nervous mechanism in the living body, each dependent on the other, namely, " 1. The unconscious involuntary nerves oflife. " 2. The conductors of external and internal feelings to the brain. "3. The conveyers of volition from the brain to the organs fitted for action ; which are respectively termed the sympathetic, the sensitive and the motor nerves." (Connection between Physiology and Intellectual Philosophy, p. 11.) The immediate bearing of the second on the third essay will be shown by the following extracts : — " We have now traced the human animal through all parts of his struc- ture ; we have shown first a system of ganglia and nerves springing from them, by means of which organic life is carried on, and appetites excited for its maintenance ; we have further seen a set of nerves whose termina- tion* are to be found at the base of the brain, which supply the senses by which man communicates with the external world; we have seen another apparatus within the cranium by which these sensations are weighed and examined, and the result of this examination transmitted finally to the motor nerves for execution ; altogether forming the most perfect piece of machinery ever constructed; for these nice operations of thought are the work of fibres and fluids contained in them, merely set in motion by the impression made at one part, and thus transmitted through the whole series." (Ibid. pp. 50, 51.) Are our readers about to take alarm and to exclaim that we are here on the verge of materialism ? Let them pause ; the facts which the investigations of Muller, Solly, and a host of modern anatomists have proved, cannot be gainsayed ; but mark the inference the author draws from them. " Look at the astronomer in his observatory ! the night is far advanced, and he is chilled and fatigued, yet he remains with his eye at the telescope; for what ? to carry on a series of observations which perhaps in two gene- rations more may give as its result the knowledge of some great law of the material universe; but he will be in his grave long ere he can expect that it will be ascertained. He sits down to his calculations and he forgets his meals, sees nothing, hears nothing, till his problem is solved ! No sense prompts to this sacrifice of rest and comfort. But do we call these per- sons insane? No, we honour them as the excellent of the earth, and wish that when the occasion comes we may have courage so to die. " I know but of one solution of the difficulty : there must be some ele- ment in man which we have not yet taken account of; some untiring, un- dying energy, which eludes indeed the fingers and the microscope of the anatomist, but which exercises a despotic sway over the animal mechanism." (Ibid. pp. 53, 54.) We hardly need inform our readers that the intelligent will is the element here alluded to, nor will it require much penetration to di- vine how this bears on the subject of the third communication ; for in thus establishing the existence of an agent palpably superior to 456 Notices respecting New Books. the bodily functions, even the highest of them, the power of thought (inasmuch as it can control even that), it naturally follows "That a force which is capable of acting as an acceleration, a retarding or a disturbance of the vital functions, must have no small influence over so delicate an organ as the brain, and accordingly we find paralysis, inflam- mation, or brain fever, and a variety of other diseases of this kind, pro- duced in many instances by causes purely mental Now a force which can produce disease must have some power also in removing or prevent- ing it; and my business tonight will be to endeavour at least to mark out how far this force can be made available to so desirable an object." (Lecture on Insanity, p. 9.) From this it will be clear what is the line of argument taken up with reference to the awful subject of insanity ; and it is fully shown that many cases of mental delusion may consist with moral responsibility, and that " nothing but an extent of disease which destroys at once all possibility of reasoning, by annihilating or entirely changing the structure of the organ, can make a man necessarily mad." (Ibid.p.12.) That there are such states in which the material organs of thought are so affected as to reduce the unhappy person to a mere " helpless machine," is unfortunately but too sure ; yet " such extensive struc- tural disease is hardly compatible with life, and is of very rare occur- rence." The facts detailed in this latter lecture, and the opinions of Dr. Conolly and others whose attention has been long directed to the subject of insanity, are indeed well worthy the most serious con- sideration, and more than ever now, since this greatest of all human afflictions is said to " have nearly tripled within the last twenty years ! " and "that of the cases less than three hundred in one thousand are the result of disease, or of unavoidable circumstances ; thus leav- ing above seven hundred resulting from bodily excess or mental mis- government." (Ibid. p. 49.) We have been anxious to show the connection which exists in these " small books," because the three together form an abundant proof of two propositions most essential to the welfare of the human race ; the first, that it is the nature of truth not to be solitary. The discoveries of modern anatomists have placed us in possession of many of the laws which regulate the mechanism of the human frame, even to the workings of those delicate fibres which are found to be the mechanical instruments of thought. What is the result ? Are we hereby reduced to acknowledge that we are mere machines ? No ; we are enabled thereby to classify the phasnomena of our na- ture ; for the anatomist and the chemist alike acknowledge that, while tracing the laws of matter, they find a disturbing force which has its source in other causes ; which cannot be referred to any con- ceivable action of those laws, — nay, which is frequently at variance with them ; and we thus arrive at that wonderful agency of the will already noticed. Again, what are the observations of those whose attention has been turned to the morbid action of that established mechanism ? — that where sufficient motive can be adduced, that indo- mitable will is able even here to step in, and at least in some degree control or counteract the diseased action. Geological Society. 457 The second proposition then which we must arrive at, if the above reasoning be correct, is, that if this mighty will exist in every human being, its early regulation is a vital consideration. Could the con- viction be once firmly rooted in the mind, that on the training of that will to assimilate itself as much as possible to His from whom it is derived, depends the temporal and eternal welfare of the indi- vidual (and who shall say of how many other beings ?), would it not be the first care of every one how to govern his own, and to assist in guiding that of all dependent on him ? The compilers of the three essays we have noticed are evidently too well read themselves to hope that they have found for others a royal road to science of any kind ; but those who have no leisure to pursue even one science in its details, may nevertheless be clearly shown in a . short compass how much there is that may be known, and their eyes will thus be opened to a conception of the majesty and beauty of the works of God of which they had little previous idea. We hail the appearance then of these works as the commence- ment of an enterprize to which all who love their fellow- creatures must wish well — that of inducing men to think, and of affording them the means of doing so to good purpose. " Ages pass away, Thrones fall, and nations disappear, and worlds Grow old and go to wreck ; the soul alone Endures ; and what she chooseth for herself, The arbiter of her own destiny, That only shall be permanent." {Southeys Roderick.) LVII. Proceedings of Learned Societies. GEOLOGICAL SOCIETY. [Continued from p. 311.] June 1, A PAPER was first read entitled, '* Notice of some Ex- 1842. ■£*- periments on the Electric Currents in Pennance Mine, near Falmouth." By Robert Were Fox, Esq. Communicated by the President. The Pennance mine is situated in killas, but to its N.W. is a granite range. Two veins have been worked ; the more northerly, which is about five feet wide and has a slight northerly dip, to the depth of sixteen fathoms ; and the other, which is about two feet thick and dips apparently to the south, to the depth of eight fathoms. Both veins nearly coincide with the magnetic meridian in their horizontal bearing. They abound with arsenical and iron pyrites interspersed with oxide of tin and sulphurets of copper and lead, arranged in many parts in nearly vertical layers parallel to the sides of the veins. The author was assisted in his experiments by Mr. J. Fox. The apparatus employed was adapted only for experiments on not very feeble electric currents, and consisted of copper wires from ,-ijth to ^th of an inch in diameter, and plates of different metals, with other contrivances for varying the methods of producing contact with the ore-points selected in the veins. The galvanometer had only one needle 2% inches long, £th of an inch wide, and ^th thick, having 458 Geological Society: Mr. Fox's Notice of an agate cup and moving on a steel point. A fine brass wire was coiled forty-eight times round the box which contained the needle. The ore-points connected with the two extremities of the appa- ratus were, in some instances, only six or eight fathoms apart, but in others thirty, forty, and even 100. The small portion of the south vein which could be tried produced a deflection in the needle of about 20° from the point of rest, after the circuit had been repeatedly made and broken ; the currents passing from east to west through the ap- paratus. In the north vein the deflections amounted to 45°, 60°, and 80° in different levels, the direction of the currents being the same as in the south vein ; and in the eastern portion of the six- fathom-level the needle traversed completely round and continued to revolve a short time after the circuit was broken. Sulphuret of lead being much more electro-positive than arsenical copper or iron pyrites, contact was made with those ores, generally dry, without affecting the currents, when the ore-points thus varied were near together, and there was no defect in the contact with them. These results were not apparently modified by the method of making the contact, or by the metal employed to effect it, provided an adequate degree of pressure was employed. For instance, a point of a copper wire pressed against a given ore-point was mostly as effec- tual as a plate of that metal similarly treated ; and when zinc and platinum were successively substituted for copper no change was produced. It is, therefore, evident, Mr. Fox remarks, that these electric cur- rents were independent of extraneous causes, and were derived from the veins only. Towards the eastern part of the north mine arsenical pyrites abounded immediately under the surface. On one extremity of the apparatus being connected with it and the other with an ore-point to the westward in the six-fathom-level, twenty-four fathoms of wire being employed for this purpose, the current, which was from E. to W., deflected the needle fifty to sixty degrees. Again, contact was made with the ore-point in the six-fathom-level by means of a small plate of copper attached to one of the wires and wedged against the ore by a wooden pole, the other copper wire being firmly pressed against the arsenical pyrites at the surface by means of a brass screw passed through a block of wood, which was retained in its place by a pole wedged against it. This arrangement admitted of the screw being loosened in the block, and the metal in contact with the ore- point being changed without inconvenience. Zinc was used after the copper for making the contact with the ore-point, but without produ- cing any modification of the current, which continued to deflect the needle from fifty to sixty degrees; notwithstanding that any action be- tween the copper in the six-fathom-level and the zinc at the surface, if it h id existed, would have been in an opposite direction, and have tended more or less to counteract the influence of the actual current. Its energy, however, was sufficient to render a short bar of iron of a horse-shoe form, with several coils of copper wire around it, feebly magnetic, and affect a needle about two inches long, moving on a Electric Currents in Pennance Mine. 459 pivot in a close box. Each pole of the needle was about three inches from the extremity of the bar, and was deflected about 2° from its point of rest, on the current being made through the coils of wire ; and where the direction of the current was reversed, a similar de- flection of the needle to the opposite side was produced. The effect, Mr. Fox observes, would have been greater had the experiment been made entirely in the six-fathom-level, where the electric action was stronger, or if the needle had been suspended and not mounted on a pivot. Having removed the electro-magnet, and other things remaining the same, a glass tube in the form of a V, having moistened clay at the bottom, was placed in the circuit with water in one branch and a solution of sulphate of copper in the other. Small cylinders of cop- per pyrites, taken from the same piece of ore, were employed to con- nect these liquids respectively with the opposite wires, the ore at the positive end of the wire having been partly dipped in water, and that at the negative end in the solution of sulphate of copper. The wires were kept at some distance above the level of the liquids, and as a further precaution, the portions not in contact with the ore were coated with sealing-wax. The liquids in both branches were at the same level, and corks were inserted to retain the pyrites in the same positions. This apparatus remained undisturbed for three days, when the column of the solution of sulphate of copper was found to have increased in height at the expense of the water in the other branch, the difference being about one-tenth of an inch. On the copper pyrites in the solution of sulphate of copper being examined, it was found to be partly coated with metallic copper. Both these effects were, therefore, produced, Mr. Fox observes, solely by means known to exist in the earth, and the experiments, he adds, seem, therefore, to have a direct and unequivocal bearing, not only on the decomposition of metallic salts under the surface, but on the causes which affect the different levels of subterranean springs, and the purification of water from bodies which it may hold in solution. A memoir " On the Elevation and Denudation of the District of the Lakes of Cumberland and Westmoreland." By William Hop- kins, Esq., F.G.S., was then laid before the Society, an abstract of which has already appeared in the Phil. Mag. S. 3. vol. xxi. p. 468. June 15, 1842. — A paper was first read " On the packing of Ice in the river St. Lawrence ; on a Landslip in the modern deposits of its valley ; and on the existence of Marine Shells in those deposits as well as upon the mountain of Montreal." By W. E. Logan, Esq., F.G.S. 1. The paper commences with a general description of the river St. Lawrence, from the junction of the Ottawa in Lake St. Louis, above Montreal, to Lake St. Peter, fifty miles below it, with a more particular account of the rapids of Lachine and the Sault Normand, produced by ledges or floors of trap rock. The author then proceeds to give an account of the packing of the ice near Montreal. The frosts commence about the end of November, and a margin of ice of some strength soon forms along the shores $ and wherever the 460 Geological Society : Mr. Logan on the St. Lawrence, water is still, it is immediately cased over. The first barrier completed across the river below Montreal is usually formed about Christmas, at the entrance of Lake St. Peter's, where the St. Lawrence is divided into a multitude of channels by low alluvial islands. This barrier is rapidly increased by extensive fields of drift-ice, enormous quantities of which are heaped upon, or forced under, the stationary mass. The space left for the water to flow being thus greatly diminished, a per- ceptible rise in the river takes place, and by the time that the ice becomes stationary at the foot of St. Mary's current, opposite Mont- real, the waters in the harbour have usually risen several feet, and as the packing rapidly proceeds, they soon attain the height of twenty, and sometimes twenty-six feet, above the summer level. It is at this period that the grandest glacial phenomena are presented. In consequence of the packing and piling of the ice, as well as the accumulation of the moistened snow of the season, and the freezing of the whole into a solid body, sometimes more than twenty feet thick, the water suddenly rises, and lifting a wide expanse of the en- tire covering of the St. Lawrence, urges it forward with terrific vio- lence, piling up the rended masses on the banks of the narrower parts of the river to the height of forty or fifty feet. In front of Montreal is a newly built revt-tement, the top of which is twenty- three feet above the summer level of the river ; but the ice broken by it, accumulates on the surmounting terrace, and before the wall was erected the adjacent buildings were endangered, the ice sometimes breaking in at the windows of the second floor, even 200 feet from the margin of the river. In one instance, a warehouse of considerable strength and magnitude, having been erected without due protection, the great moving sheet of river-ice pushed it over as if it had been a house of cards ; and in another case, where a similarly situated and equally extensive warehouse, four or five stories high, had been provided with a range of oaken piles placed at an angle of less than 45°, the drift ice rose up the inclined plane, and after meeting the walls of the building, fell back, and formed, in a few minutes, an enormous but pro- tecting rampart. In some years the ice accumulated nearly as high as the roof of the warehouse. Several of these grand glacial movements take place, sometimes at intervals of many days, but occasionally of only a few hours, the permanent setting being indicated by a longitudinal opening of con- siderable extent in some part of St. Mary's current. This opening, which is never afterwards frozen over, even when the temperature is 30° below zero of Fahrenheit, is due to the water having formed a free subglacial as well as superficial passage, in consequence of its own action and the cessation in the supply of drifting ice. From this period the waters gradually subside, but seldom or never to their summer level ; and when they have attained their minimum, the trough of the St. Lawrence exhibits, Mr. Logan states, a glacial landscape of undulating hills and valleys. On the banks of the river, near Montreal, is an immense accumu- lation of boulders, chiefly of igneous rocks, the most abundant con- sisting of syenite ; and multitudes of them are stated to be " tons in and on the Modern Deposits of its Valley. 461 weight." As they appear also above the surface in the shallow parts of the river, Mr. Logan is of opinion that the bed of it likewise teems with them. Their position has been frequently observed to be changed, both in the St. Lawrence and on its banks, at the breaking up of the ice in the spring. Mr. Logan examined, in the autumn of 1841, the boulders between Montreal and Lachine, a distance of nine miles, and again in the spring of the present year (1842), when he missed some which had particularly attracted his attention ; but he adds, he may, from not having mapped their position, have inad- vertently passed them over. The author then offers some remarks on the power of ice in moving or traasporting boulders along the river, and furrowing the surface of the fixed rocks, as well as along the shores j but he is of opinion that the distance is limited to which they may in the latter position be conveyed annually. It is not only on the immediate banks of the St. Lawrence that boulders abound, as they are spread more or less over the whole island of Montreal, and the plains on the opposite side of the river. Mr. Logan states that he had not examined their position with sufficient accuracy to offer an opinion respecting the causes of their distribu- tion, but they appeared to him to be more abundant in the upper than the lower part of the island, and they are stated to cease altogether not many miles below it ; but their size is not less at the limit of their range than elsewhere. 2. Landslip. — The country for a considerable distance on both sides of the St. Lawrence, between Montreal and Quebec, is very level, and is generally covered to some depth by a highly levigated deposit composed of clay, sand, and calcareous matter resting on black shale and black and grey limestone belonging to the Silurian system. This flat region or trough is bounded on the north-west by granitic and syenitic hills about 500 feet in altitude ; and on the south-east by an undulating picturesque tract, composed of a hard quartzose conglomerate, which crops out from beneath the limestone, and is succeeded by pyritiferous clay-slate. The cleavage of this formation is stated to be from N.E. toS.W., or parallel to the general strike of the beds. Between Montreal and Lake St. Peter, the banks of the St. Law- rence have generally a height of twenty or thirty feet above the level of the water, but the plains near the margin of the river are occa- sionally so low as to permit the formation of marshes, and on the southern side the general surface does not apparently attain the same altitude as on the north-western. On this side, at a distance varying from one to six miles from the St. Lawrence, there is a sudden rise of 1 00 feet, forming the boundary of a terrace which extends to the granitic hills, where a second rise takes place of 200 or 300 feet. The terrace, composed of soft materials, has a very even surface over a great area, being only modified by the protrusion, at a few places, of the Silurian limestone. It is however intersected by the rivers which flow from the granitic range, and which, dashing down from the hills, cut at once into the terrace, nearly to the level of the St. Law- rence. The banks of these tributaries are liable to landslips, and an 462 Geological Society: Mr. Logan on the St. Lawrence, extensive one which occurred on the Maskinonge in 1840 is described in this part of Mr. Logan's paper. The waters of that river, after passing through a series of lakes, are precipitated from the granitic region in a beautiful cascade, and then flow along a deep valley in the terrace, the only interruption to their course being a collection of boulders combined with a mill-dam, pro- ducing a fall of about fifteen feet. The valley has a uniform breadth, the distance between the summit of the banks being about 200 yards, and the height of the banks is 120 feet. The point at which the landslip occurred is nine miles from the granitic hills, and where the river, ten to twenty yards wide, changes its direction from south to west, for 700 yards. The movement com- menced about eight o'clock on the morning of the 4th of April 1840, and when the winter snow was still on the ground. The mass of marly clay, first detached, was about 200 yards in breadth and 700 in length ; and it was followed, at intervals of a few minutes, by four others. The whole of the area thus affected amounted to about eighty-four acres, and the total length was 1300 yards; but the breadth varied, the narrowest part being nearest to the river, and the widest, equalling 600 yards, a considerable way from it. The moving mass first crossed the stream, and then splitting against the opposite bank, where it averaged a thickness of seventy-five feet, one-half turned up the valley for about three-quarters of a mile, and the other half down it for an equal distance, forming a dam half a league in extent. The whole operation was completed in about three hours. For some time after the movement began the surface of the great masses remained unbroken, and the sugar maple-trees, with which they were covered, preserved, for the greater part, an erect position. Two farm-steads were also carried away, and though the people escaped, the cattle, and other live stock perished with the falling buildings. The masses which moved along the valley had a height of about sixtv feet, and their surface was slightly raised, but the front of each terminated in a blunt point which projected in the middle and in the lower part. As these great double-acting plough- shares advanced, they turned up, Mr. Logan says, the soft mud from the bed of the river, casting it on the banks, and producing so into- lerable a stench that no one could approach within 100 yards. This odour, he conceives, arose from the sulphuretted hydrogen produced by the decay of vegetable matter. No sooner was this dam formed than the waters of the Maskinonge' began to rise, and the houses, with every other thing composed of wood throughout the whole of the nine miles to the granitic hills, were set afloat. It was two days, however, before the lake thus formed overtopped the barrier; but by October it had transported into Lake St. Peter so great a portion of the dibdcle that the river was not more than ten feet above its ordinary level. When Mr. Logan examined, in the subsequent autumn, the spot where the slip took place, the bottom of the widest part of the chasm was thirty feet below the level of the surrounding country ; and about 400 yards from the river, where the disturbed district narrowed, there . and on the Modern Deposits of its Valley. 463 was a sudden additional descent of fifteen feet. From this point the ground sloped gently to the water's edge. The only vestiges of the original surface then visible were a few patches of grass, and occa- sionally twenty or thirty yards of wooden fence, the superficies being composed of parallel mounds three or four feet high, and which over the central portion of the area ranged at right angles to the axis of the slip, but along the sides conformably with the bounding outline. A circumstance connected with the form of the disturbed district Mr. Logan considers worthy of attention. Around the whole of the area, except the most northern extremity, there was, previous to the slip, a depression of the surface, due on the eastern side to the slope of the right bank of the river, and a tract of low land ; and on the western side to a dingle traversed by a brook. After the slip, a ridge, not many feet wide, remained between these lower surfaces and the chasm, forming a marginal rim which was broken through at only one point, where it was intersected by a dingle which united with the one on the western side. The cause of the slip, Mr. Logan is of opinion, was pressure on an inclined plain, assisted by water ; and though he was not able to de- termine the nature of the subsoil, he is of opinion, from a. survey of the surrounding country, that it consists of the Silurian limestone, the dip of which, where visible, is in the direction of the slip. If boulders were at the bottom of a mass moved in the manner of the Maskinonge slip, it is easy to see, Mr. Logan observes, that parallel grooves and a polish on the surface of rocks may not, in all cases, be due to the agency of ice. 3. Marine Shells on Montreal Mountain. — After alluding to Mr. Lyell's account of the fossil shells collected by Capt. Bayfield* in the neighbourhood of Quebec, Mr. Logan proceeds to describe briefly the circumstances under which four of the same species of mollusks were found near Montreal. The spot from which they were principally pro- cured is stated to bear very much the character of a raised beach, and was determined barometrically to be 430 feet above the Montreal harbour, or about 460 feet above the Atlantic, the greatest height at which Captain Bayfield's specimens were found, being 300 feet above the level of the Gulf. The above altitude of the Montreal deposit is further stated to be 240 feet above the level of Lake On- tario and 7o feet above the Falls of Niagara, but to fall short of Lake Erie by about 1 05 feet. The four ascertained species obtained by Mr. Logan are the following : — ' 1. Saxicava rugosa, very abundant to the north of the road to the C6te de Nieges, in a bed of coarse sand inclined conformably with the side of the hill, and which has, above it, a layer of pebbles and small boulders. The altitude of this position is 430 feet. The shell occurs also, but not abundantly, above the village of St. Henry, on the road to Lachine, on the top of an elevated terrace along the bank of the St. Lawrence, and 120 feet above the river ; it has been also obtained on the same terrace at Logan's Farm. * See Phil. Mag. S. 3. vol. xv. p. 399, and Geol. Trans., 2nd Series, vol. vi. p. 135. 464 Geological Society. 2. Tellina Groenlandica, which is found abundantly at St. Henry, and to a less extent on Logan's Farm and on " the Mountain." 3. Tellina calcaria. — One valve of this shell was picked up on ** the Mountain." 4. Mya truncata. — Several hinges of this species were obtained at St. Henry. 5. Mytilus. — A broken valve was found on " the Mountain." The first four fossils, Mr. Logan says, he has been informed, were found by Mr. Murchison and M. de Verneuil at Ust Vaga, 250 miles from the White Sea, and 130 feet above its level. He also alludes to Mr. Lyell's comparison of the Quebec shells with species which occur at Uddevalla. A communication was afterwards made by Dr. Grant, F.G.S., " On the Structure and History of the Mastodontoid Animals of North America." The chief object of this communication was to point out the structural differences and zoological distinctions of the Mastodons and Tetracaulodons of North America ; and the inquiries were in- stituted in consequence of the favourable opportunity afforded by the temporary exhibition, in this metropolis, of Mr. Koch's barge collec- tion of organic remains from the State of Missouri, consisting prin- cipally of the relics of these two genera. After pointing out the important applications of the study of these remains, and the geological relations of Mastodontoid animals, and the discordant opinions of zoologists as to their specific distinctions, Dr. Grant entered into extended details regarding the general struc- ture and the peculiarities of the skeleton in the three principal Mastodontoid genera, Mastodon, Tetracaulodon, and Deinotherium, which are compared with those of the elephant and other allied ge- nera. The fifth section of the memoir is occupied with the descrip- tion of the development, forms, structure and changes of the dental system of Mastodontoid animals ; and each tooth and tusk of the three principal genera are described and compared, and the principal modifications they exhibit according to difference of age, sex, and species. After pointing out the necessity of including the entire se- ries of successive teeth, in the dental formula? of genera, where the teeth are constantly displacing and succeeding each other through the whole of life, the author announces the dental formulae of the four Proboscidian genera of Pachyderma to be 2 0 8—8 Elephas,Inc. -jr-, can. -^-, mol. -, = 34. Mastodon. Inc. -pr, can. -z~. mol. = ~, = 26. ' 0 0 o—o ,JT 2 ° ,6-6 Tetracaulodon, Inc. -77, can. -jr. mol. s ~, = 28. 2 0 6 — 6 x. . , • ,, 0 0 ,5-5 Deinotherium, Inc. _ , can. „ , mol. . _ ^-, = 22. Dr. Grant on Mastodontoid Animals. 465 For the determination of the dental formula; of Mastodon and Te- tracaulodon, Dr. Grant relied entirely on the splendid collection of jaws, crania, and teeth in Mr. Koch's possession, which afford ample means for the solution of that problem. For the dental formula of Deinotherium he has been indebted solely to the casts and fragments of that genus in the British Museum. After explaining the uncer- tainties and fallacies to which naturalists have been exposed in the identification of species, from not having ascertained the entire dental series in any Mastodon, the sixth section of the memoir describes the distinctive characters and the distribution of the Mastodon angusti- dens, M. latidens, M. Elephantoides, M. minutum, M. Tapiroides, M. Andium, M. Borsoni, M. Humboldtii, M. Turicense, M. Avernense, M. giganteum, M. Cuvieri, and M. Jeffersoni. The seventh section of the memoir is devoted to the examination and description of the generic characters of Tetracaulodon, as established by Dr. Godman, and as founded on the number and form of the teeth, the peculiarities of their microscopic structure, the form of the jaws, the tusks, the alveoli of the tusks, the intermaxillary fossa, the infra-orbitary fora- mina, and other influential characters. The eighth and last section of this paper is occupied with an account of the distinctive characters and the distribution of the known species of this genus ; viz. Tetra- caulodon Godmani, T. Collinsii, T. Tapiroides, T. Kochii, T. Haysii, and T. Bucklandi. June 29, 1842. — Seven communications were read. 1 . " Notices connected with the Geology of the Island of Rhodes." By Mr. T.A.B. Spratt, Assistant-Surveyor of H.M.S. Beacon. Com- municated by C. Stokes, Esq., F.G.S. The observations detailed in this paper were made during the sum- mer of 1 840. The geological structure of the Island of Rhodes, Mr. Spratt states, is simple, and the distribution of the deposits easily defined. The formations consist of mica schist, shales, limestones, trachyte with basaltic rocks, large beds of shingle, both anterior and posterior in origin to the volcanic aera $ and very extensive tertiary deposits. The mica schists occur in the central districts near Alleyermah and Sclipio, but do not form ridges of very great altitude. The limestones are scattered in detached masses and rest appa- rently on argillaceous shales of a black, light cream or reddish colour, but the positive order of superposition the author had np opportunity of determining. He failed also in detecting in them any organic re- mains, but he is of opinion that they are of contemporaneous origin with the strata near Smyrna, assigned by Mr. Strickland to the Hip- purite limestone. The shales are well developed in several places around the base of Mount Ottayaro, but more particularly in the valley west of the village of Embono. Both the schists and the limestones exhibit, Mr. Spratt states, proofs of great dislocations, and he is inclined to ascribe these effects to the outburst of the volcanic rocks which constitute^so large a por- tion of the central and southern districts of the island. He mentions as instances of these disturbed beds a thin stratum of limestone which Phil. Mag. S. 3. Vol. 23. No. 154. Dec. 1843. 2 H 466 Geological Society : Mr. Spratt on the projects, near Lardose, from the enclosing schists like a wall, and tra- verses several valleys as well as ridges 5 also some curiously con- torted strata on the north face of Mount Agramitty. The loftiest summits in the island are composed of limestone. Mount Attayaro (anc. Atabyrius), the highest, exceeds 4000 feet in altitude, and at least three-fourths of it are composed of horizontal beds of limestone. The other principal calcareous mountains are Elias, Agramitty, Archangilo and Lindo, all remarkable detached points, and believed by the author to have been islands during the deposition of the tertiary formations. Mr. Spratt likewise mentions in proof of the limestone mountains forming islands during the tertiary epoch, that at Mount Gallatah, near the north-east extremity of the island, fragments of the rock are honeycombed and perforated exactly in the same manner as the limestone on the shore of many parts of Asia Minor, being the ope- ration of a very minute boring animal. The igneous rocks constitute the ridges next in altitude, as the lesser Elias and the southern mount of Skathee, besides a great por- tion of the ridge connecting it with Attayaro and a few others. The tertiary deposits are assigned by Mr. Spratt to a period poste- rior to the outburst of the igneous rocks, and when only the higher ranges of hills were above the sea level. They consist of sands and marls tranquilly accumulated in horizontal beds, and are distributed in basins which occupy nearly a third of the island ; but having been extensively denudated, they are intersected by deep and wide valleys. The western basins are distinguished from the eastern by containing only freshwater remains. In the hill to the west of Kalavorda the author obtained similar testacea, marine shells being also apparently wanting, but his examination of it was limited. In some of the neighbouring ridges similar strata are also considered to be destitute of organic remains. No river now flows through the district containing the freshwater deposits, except a small stream about the size of the Bournarbashi of the Troad, nevertheless broad shingle beds traverse the longer valleys and form a remarkable feature in the western division of the island. Mr. Spratt is of opinion that these valleys were the channels of very considerable streams which once flowed from the mountains, and that the accumulations are too great to be accounted for by the torrents of the present winters. The eastern tertiary deposits contain only marine remains, but in vast abundance in some localities, as in the basins of Lardose, Archan- gilo, and Koskinou, which the author says, appear to have been inlets or channels protected hy the high peaks around the base of which the deposits now lie in horizontal terraces or zones. At Lardose the fossils are most numerous in an insulated hillock of loose sand behind the village, and Mr. Spratt procured there specimens of almost every species which he obtained elsewhere. A quarter of a mile to the northward he noticed a bed of gigantic oysters and " scollops "; the diameter of one of the largest being thirteen inches, and the thickness of one of its valves five inches. Geology of the Island of Rhodes. 467 Near Melona and Archangilo fossils may be procured in abun- dance, but the species are grouped ; and about a mile north of the latter place the author found on the end of a low ridge which pro- jected into the plain, a thin stratum of calcareous sand containing numerous fossil leaves, also marine shells and an ichthyolite. The leaves resembled those of the olive, oleander, and plane tree, now growing on the island. In the neighbourhood of Koskinou and Rhodes fossils are also very abundant, especially in the upper deposits. Mr. Spratt gives the following list of the strata exhibited in a hill near the town of Rhodes, and he says that it affords a type of the whole of the adjacent depo- sits, with the exception of the distribution of the fossils, which are sometimes wanting, sometimes plentiful, in the same bed. Top. — Calcareous conglomerate, containing Turbo rugosa in great abundance. Laminated marls in which fossils are sometimes numerous, but at this locality they are wanting. Coarse sand, inclosing species of Pecten, Turbo, Echini, and corals in great confusion and seldom perfect. Fine sand from which the author procured only a species of Venus. Marls without fossils, at this point sometimes indurated. Greenish sand. Fine brownish sand with numerous fossils. Total thickness about 300 feet. In the deposits along the north shore Mr. Spratt procured no fos- sils, though he very closely examined Mount Paradiso and Philielmo. The strata in these hills and in that overhanging Tholo and Soronee dip at a considerable angle to the north j and exhibit the greatest visible thickness of the tertiary deposits, Paradiso, the highest, having an altitude of 920 feet ; but in the basin of Archangilo they attain nearly the same vertical dimensions. The tertiary strata are apparently continuous along the north coast, so that no defined margin between the supposed western lacustrine deposits and those of decidedly marine origin is indicated by an inter- vening ridge or formation of a different character. The long ridge of Skathee is considered however by the author a natural boundary between the basin of Palatshah and the eastern deposits, but he was unable to determine if the strata around Katavyah with which it is believed to be connected, contain marine or freshwater shells. There are also in several parts of the island elevated shingle beds of considerable thickness ; some of them, composed entirely of rounded limestone pebbles, occurring on the sides of the calcareous moun- tains ; while others consist of limestone and volcanic materials, and others again wholly of volcanic fragments. These accumulations, Mr. Spratt says, are evidently of two epochs, one anterior to the great volcanic sera, and the other intermediate between it and the tertiary series, the sands and marls of that group being in several places around them. 2H2 468 Geological Society : Mr. Nasmyth on the Structure 2. " On the minute Structure of the Tusks of extinct Mastodon- toid Animals." By Alexander Nasmyth, Esq., F.G.S. The author, at the commencement of his memoir, acknowledges his obligations to Dr. Grant for having first called his attention to the minute anatomical structure of the tusks of Mastodontoid animals ; and for having placed at his disposal a copy of the Swedish edition of Retzius's demonstration of the typical structure of the dental or- gans of animals. Availing himself of the able tuition afforded by the Swedish Pro- fessor, Mr. Nasmyth says, he has prosecuted the subject, and that these inquiries, besides explaining to him the structure of that portion not completely investigated by Retzius, have unfolded to him some observations which [are now generally acknowledged to be truths in the valuable but intricate department of animal development. He further says, that he has been led to results differing somewhat from those of Retzius, so far as the physiology of the cellular tissues is concerned ; yet the general appearances exhibited and the manner of displaying them will remain, he adds, lasting memorials of the ta- lents and ingenuity of the Swedish Professor. The specimens to which Mr. Nasmyth's attention has been directed form part of the collection of Mr. Koch, and they were delivered to him as belonging to Mastodon giganteum, Teiracaulodon Godmani, T. Kochii, T. Tapiroides, and the Missourium. In the analysis of each specimen he considers— 1st. The constituent structures of the tusk. 2nd. The comparative extentof each of the constituent structures, as far as it can be ascertained. 3rd. Each constituent structure regarded separately in its minute and individual elements. 4th. The conclusions derived from the premises as to the place which the animal should occupy in zoological classifications. The principle upon which this mode of analysis is based, is that of the infinite variety which nature effects from limited materials, while the constancy of each variety throughout the same species is perfect. This constancy extends, Mr. Nasmyth observes, not only to the con- stituent structures of each tooth, but to the extent of each constituent, as well as to the peculiar arrangement of the minute elements of which each of these structures is composed. The examination of each tusk evinces so marked and peculiar a structure, that a cursory inspection will, the author thinks, sufficiently demonstrate specific distinctions, which he supposes must have been accompanied by concomitant peculiarities of organization subservient to separate and distinct habits. In the following descriptions the word corpascule is used to desig- nate those appearances constituting the characteristic of bone, but denominated by Retzius cells, because the author is persuaded that those appearances are truly of a corpuscular character ; and the word cell is used to designate the structure of the interfibrous material which was left almost entirely out of account by Retzius, and de- scribed by others as structureless, but demonstrated by the author to of the TusJcs of extinct Mastodontoid Animals. 469 be most characteristically organized in the different groups of ani- mals. The term fibres is used, moreover, to define those appearances which Retzius considers due to a tubular structure, because the au- thor has been unable to find anything which confirms this theoretical appellation founded on the existence of a series of continuous rami- fying tubes. This question therefore he leaves in abeyance. Mastodon giganteum. — The constituent structures of the upper tusks are only two, crusta petrosa and ivory. The crusta petrosa, in the specimens examined, is comparatively thin, or about half a line j but the extent of the investigation being necessarily limited, the au- thor considers that the observations on this head are incomplete. The corpuscules of the crusta petrosa are scattered irregularly ; but they are numerous and give off radiating branched fibres, tending generally either from the surface or to the surface of the tusk. There are hardly any independent fibres. The cellular structure of the in- terspaces is clearly marked. The junction of the ivory with the crusta petrosa is well defined by a clear line, succeeded by a plumose appearance arising from a con- geries of very minute ramifying fibres. This appearance looks, Mr. Nasmyth says, as if it arose out of, and formed the termination of, the main fibres which join the layer undivided. The compartments of which the main fibres are made up are par- allelograms resembling those of the Elephant, and are most easily observed in vertical sections, while the cellular structure of the interfibral spaces is clearest in transverse sections. Minute corpus- cular appearances are scattered over the substance, and so aggregated as to form at intervals concentric layers. The characteristic differ- ences between the structure of the tusks of the Elephant and Masto- don, Mr. Nasmyth observes, consist principally in the presence of transverse fibres in the crusta petrosa of the Elephant, and the greater number and regularity of its corpuscules in the Mastodon, as well as in the peculiar disposition to a transverse direction of its radiating fibres. In the ivory the most striking peculiarity consists in the nu- merous bands of corpuscular-looking bodies in its substance. These appearances, so frequently observed in ivory, Mr. Nasmyth is of opi- nion, depend, as pointed out by him, on the thickness of the animal matter of the interfibral cells. Tetracaulodon Godmani. — The author says there is a great dissi- milarity in the constituent structures of tusks of this Pachyderm and those of the Mastodon, while on a cursory examination of the mi- nute organization of these structures there is an apparent similarity. The crown of both the upper and under tusk is coated with enamel extending below the level of the alveolar process, with crusta pe- trosa external to it, the body of the tusk being composed of ivory. The alveolar process of the upper tusks is large and deep, greatly exceeding that of every other tusk which the author has examined, and showing, he says, that the actions in which these organs assisted, must have been very powerful. The habits essentially necessary to the exigencies of an animal being, Mr. Nasmyth observes, the same in youth as in adult age, the 470 Geological Society : Mr. Nasmyth on the Structure organization of the individual tissues is the same at hoth periods, though certain modifications of instruments are exacted at successive stages of existence. Thus, in early youth, when the frame is not powerful, every efficiency is given to the cutting edges of the dental apparatus ; and the author states a fact he believes never before re- marked, though long noticed by himself, that the tusks of the young Elephant and Walrus are tipped with a very thin layer of enamel. The head of the Tetracaulodon Godmani examined by Mr. Nas- myth is shown to have been that of an animal in which two of the adolescent teeth are well developed. The crusta petrosa of the tusk was about half a line thick, and extended over the whole of the visible surface. The corpuscules were irregularly disposed, but closely ag- gregated, and exhibited in the transverse section an irregularly circu- lar shape with occasionally angular points. The radiating fibres were numerous, ranging in all directions ; and the independent transverse fibres were also numerous, traversing with a curved course the whole substance. The cells of the interspaces were visible. The enamel on the upper tusk was a line thick. The parallel rows of constituent cells throughout the external half ranged in straight lines, but throughout the internal half they were curved diagonally. There was no clear space between the enamel and ivory, but the line of junction was well defined. A plumose layer of fibres, apparently the peripheral termination of the main undivided fibres of the ivory, suc- ceeded to the enamel. The component bulbs of the fibre were round, but not often visible, and were best seen in the longitudinal section. The fibres were placed at about the distance of two interfibral spaces, and curved in the transverse section as well as in the vertical, but in the latter direction slightly. A minute corpuscular appearance was scattered over the substance, and the cells of the interfibral material were visible. The crusta petrosa, enamel and ivory of the under tusk were similar to those of the upper, except that the constituents were so transpa- rent as hardly to betray any characteristic. The parietes of the cells of the enamel are more defined in the under tusk. Besides the important characteristic of the thick coating of enamel, the tusk of the T. Godmani presents manifest differences from that of the other species, in the elements of each of the constituents. The radiating fibres of the corpuscules differ from those of Mastodon gi- ganteum in being given off equally in all directions : in the M. gigan- teum the numerous independent fibres of the T. Godmani are also absent, and the zones or belts of minute corpuscules in the ivory of the M. giganteum are wanting in that of the T. Godmani. Tetracaulodon Kochii. — The tusks of this Pachyderm have only two constituents, crusta petrosa and ivory. The crusta petrosa varies in thickness, equalling in some parts an inch. In the vertical section the corpuscules are irregularly oval and irregularly disposed at the di- stance of three or four corpuscular diameters, and they give oft occa- sionally many fine radiating fibres. Numerous independent trans- verse fibres pass in a curved direction also throughout the substance, their beaded or minute corpuscular appearance being very visible, of the Tusks of extinct Mastodontoid Animals. 47i and they are of an irregularly twisted oval form. The cells of the interspaces are likewise visible. The ivory of the upper tusks consists of very slightly undulating, undivided fibres, with the cells of the interfibrous substance well marked, but semi-transparent. The fibres of the under tusk slightly undulate, and present occasionally an appearance of thorny projec- tions. The compartments of the fibres are easily seen, and are irre- gular in size, but rounded. Tetracaulodon Tapiroides. — The tusks consist also of only crusta petrosa and ivory, and the resemblance in the microscopic structure of this species with that of T. Kochii is great. The thickness of the crusta petrosa is considerable. The very irregularly-shaped corpus- cules, placed at intervals of two or three corpuscular diameters, are semi-transparent, and without radiating fibres in the external half j but those situated in the internal half are of the usual opacity, and give off numerous radiating fibres. Transverse, irregularly beaded, independent fibres traverse the substance, making one distinct curve in their passage across it. The cells of the interspaces are slightly visible. The ivory is so translucent and homogeneous as to exhibit generally very little character. The fibres undulate but do not divide, forming an abrupt line of junction with the crusta petrosa. The form of the beaded compartments of the fibre is oblong, not rounded, as in T. Kochii, and they do not exhibit thorny projections. These are the only marked differences in the two species. The cells of the semi-transparent interfibral space are generally visible. Missourium. — The constituents of the tusks are likewise crusta pe- trosa and ivory ; but their intimate structure, Mr. Nasmyth says, is more peculiar, so far as his examination has extended, than that of the tusks of the preceding animals. The crusta petrosa, in the section which the author was permitted to make, was more than three-eighths of an inch thick. Thecorpus- cules were very numerous, and generally within the distance of one diameter. The granulated compartments of which the corpuscules were composed, were very visible, and often without radiating fibres, but where these occurred they were of a coarse structure. The transverse independent fibres were beaded in coarse, somewhat tor- tuous, ovoid compartments, and ranged very close to one another, with interfibral spaces of about only two fibral diameters, and followed a straight, perpendicular and parallel course to the surface. The cells of the semi-transparent interfibral space were generally visible. The appearances presented by the ivory at its junction with the crusta petrosa, Mr. Nasmyth was unable to ascertain j but in the substance of the ivory the fibres undulated, and their beaded com- partments had a rounded shape : these fibres were frequently in- vested with an irregular congeries of granules distinct from the inter- fibral cells. Towards the central portion of the ivory the compart- ments forming the fibre were frequently so disposed as to give the fibre a peculiar tortuous appearance. The peculiarities of the tusk of the Missourium are given by Mr. 472 Royal Astronomical Society. Nasmyth as follows j and, he says, they would certainly indicate a di- stinct species of Mastodontoid animal : — 1. The great extent of the crusta petrosa. 2. The close aggre- gation of its corpuscules. 3. The granulated structure of these cor- puscules. 4. The coarse granulated structure of the compartments of the radiating fibres. 5. The close parallel perpendicular arrange- ment of the fibres of the crusta petrosa. 6. The irregular congeries of granules surrounding the fibres of the ivory. 7. The peculiar tor- tuous appearance occasionally exhibited by these fibres. On the whole, Mr. Nasmyth observes, the several species of ani- mals noticed in his paper seem to be nearly allied, and fitted to exist under nearly similar conditions ; and though the early aeras to which these Pachyderms must be referred, present, he says, consider- able uniformity of circumstance, yet they must have demanded some variety of detail in the animal organization. Finally, the characteristics in the minute structure of the tusks of all the five animals betray, the author observes, greater varieties than are found to exist even betwixt some genera possessed of tusks ; and if it be established that specific differences positively do exist among all these animals, then the value of this kind of observation is great; but if the five animals are all to be grouped in one category, then this mode of observation is of no value in palaeontological researches. ROYAL ASTRONOMICAL SOCIETY. [Continued from page 314.] June 9. (Communications respecting the Comet continued.) — ■ 15. Letter from Professor Kendall, containing Observations of the Comet made at Philadelphia. Communicated by Lieut. -Col. Sabine. Philadelphia, April 27, 1843. Sir, — I send you the result of the observations of the great comet of February 1843, made by Mr. Walker and myself with the Fraun- hofer equatoreal, at the Observatory of the Central High School, lati- tude 39° 57' 8", longitude 5h 0m 41s>9 west of Greenwich. The mea- sures were all made with the Fraunhofer filarmicrometer, power 75, except on the 9th and 1 Oth of April, when the extreme faintness of the comet compelled us to use the ring-micrometer. We first saw the nucleus on the 11th of March and brought the comet to the centre of the field, and read the graduations. The place given on that evening is liable to an error of two minutes of space. That of the 10th of April is liable to an error of about one minute of space. Those of the other evenings were the result of satisfactory measures. The nucleus on the 1.1th of March was near the star £ Ceti, of the third magnitude, and was of about the same brightness. The tail extended between Rigel and Sirius, about 1° south of its position on the 18th, when we saw it and also the nucleus, but made no measures. In the comet-searcher the nucleus appeared on the 11th, with a well-defined disc, larger than that of Jupiter in the same in- strument. In the 9-feet equatoreal it had no appearance of a disc, but only of a nebulosity gradually condensed toward the centre ; so that it was impossible to distinguish any nucleus. I have no doubt that this comet was seen in the day-time, on the 28th of February Royal Astronomical Society, 473 and the 1st of March. The particulars are stated at length in Pro- fessor Silliman's Journal. An observer at Woodstock, Vermont, saw the nucleus and tail in a good telescope, probably a 3^-feet Dollond. Mr. Clark of Portland- Maine, a teacher of navigation, measured its distance from the sun's limb at the time of culmination, and found it to be 6° 15£\ Professor Loomis, of Western Reserve College, Hudson, Ohio, has computed the intensity of the comet's light on the 28th of February, and finds it to have been twenty-four times brighter than on the 1 1th of March ; that is, twenty-four times brighter than a star of the third magnitude. Star of No. of Comet's observed No. of Mea- 1 Comet's observed Mean Time, Philadelphia. Comparison and Magni- Mea- R. A. corrected for Parallax, but not Dec. corrected for Parallax, but not tude. for Aberration. sures. for Aberration. 1843. d h m 8 ll 111 s O ' /. March 11 7 21 2079 1 43 35-00 — 11 35 2300 19 7 25 55-68 *b, 7-8 2 2 57 14-46 i" — 9 26 50-44 *c, 9- 10 i — 9 26 5302 22 7 46 48-46 *h, 8-9 7 3 17 44-47 2 — 8 35 58-55 23 7 39 59-79 *j, 8 14 3 23 50-21 3 — 8 19 13-16 24 7 26 51-79 *k, 8-9 4 3 29 36-44 2 -83 35-48 *l, 8-9 4 36-61 1 4035 *m} 8 4 36-74 1 54-90 26 7 36 10-32 *», 8-9 5 3 40 28-93 1 — 7 32 27-12 *o, 8 5 29*59 1 — 7 32 17-14 April 1 7 0 20-88 *s, 9 8 4 7 54-53 *t, 8-9 6 54-68 2 7 48 6-35 *u, 9 8 4 11 50-91 2 - 5 58 46-84 7 7 52 10-20 *v, 8 4 4 29 33-93 *y> 8 4 33-93 *z, 9 4 33-44 9 7 57 59-64 *A, 9 7 4 35 52-21 7 - 4 45 38-29 10 8 21 46-25 *A, 9 l 4 39 100 ] — 4 36 38 00 Apparent places of the Stars compared above with the Comet. Name. Right Ascension. Declination. h m s b 2 57 37-68 —9 33 31-84 c 2 57 47-57 —9 27 27-04 h 3 19 17-08 -8 32 6-08 i 3 24 2503 8 22 38-02 k 3 30 12-86 8 10 56-86 I 3 30 17-24 8 10 4-51 m 3 30 31-57 8 0 1308 n 3 40 9-48 7 29 53-63 0 3 41 8-18 7 30 2-58 s 4 8 15-74 t 4 8 57-61 u 4 13 21-22 5 56 13-37 V 4 27 36-41 5 3 4609 y 4 31 2113 5 7 25-53 z 4 31 2405 5 0 48-52 A 4 36 4-31 4 35 56-58 474 Royal Astronomical Society. From the observations of the 19th and 26th of March, and 2nd of April, we have computed the following elements : — Perihelion Passage, Feb. 27d,436953, Greenwich mean time. Long, of Ascending Node. . . . 1°55' 18"* 6 from mean equinox of [March 26. Long, of Perihelion 277 43 53*7 Inclination 35 34 0'8 Perihelion Distance 0-00701906 log q = 7'8462789 Motion retrograde. The ephemeris computed from these elements, after applying aberration, requires the following corrections in order to agree with our observations : — Correction in Correction in Right Ascension Declination t't A X. AS. March 19. -0-33 +38-3 22. -1-19 + 5-0 23. -1-38 +27-5 24. -0-94 + 1-8 26. —2-07 + 23-9 April 1 . + 1-99 2. + 4-50 -21-6 7. +7-82 9. + 9-25 -54-1 This corresponds well enough with the observations to be used in computing the parallax and aberration, and in reducing to a com- mon date the places observed during the same half hour. These ele- ments have some resemblance to those of the comet of 1 689 as com- puted by Pingre. The inclination, however, of the latter, 69° 17', differs too much to be consistent with their identity. Professor Ben- jamin Pierce, of Harvard University, Cambridge, Mass., has recom- puted the observations used by Pingre, and finds for the elements of the comet of 1689, Perihelion Passage 1689, December 2d,1403, Greenwich mean time. o / Longitude of Ascending Node. .. . 344 18 Longitude of Perihelion 271 16 Inclination 30 25 Perihelion Distance 0*0103 Motion retrograde. The elements of the comet of 1843, with a period from 1689, December 2d,14G3, to 1843, February 27dl4370, represent the places given by Pingre within 5°. Whether the errors of Pingre's places of the comet of 1689, together with the effect of perturbations, amount to 5°, is a subject worthy of investigation. It has never happened, I believe, that two comets have appeared with elements agreeing so well, without being found in the end to be the same. Respectfully, Lieut. -Colonel Sabine, R.A., Woolwich. E. O. Kendall. Intelligence and Miscellaneous Articles. 475 16. Observations of Distance of the Comet from known stars, made at Demerara by Captain Geale of the ship Isabella, Lieutenant A. S. Glascott, R.N., and James Donald, Esq. Communicated by- Sir John Herschel. March 11 at7h20raM.T. March 12 at 7 22 March 13 at 7 5 March 19 at 7 15 March 26 at 7 10 March 27 at 7 12 March 31 at 7 35 > rRigel = 50 23 Distance of comet from J g^Su^" = 77 30 LCanopus = 68 23 Length of tail 46°. rRigel = 47 24 Sirius = 69 0 Distance from < Aldebaran =46 40 Canopus = 67 H l Capella ... = 71 55 r Canopus... = 65 1 «*— ■•- ISfcrSS [ Aldebaran = 43 30 r Capella ... = 62 24 J Sirius = 54 14 1 Canopus.. = 59 17 LRigel = 32 6 Distance from. Length of tail 42°. r Sirius = 44 10 Distance from J £aPella '" = f_ fR j Canopus... = 55 46 Length of tail 32° Distance from Length of tail 30° iRigel = 21 35 {Sirius = 43 8 Rigel =20 30 Canopus... = 55 37 Capella ... = 56 28 f Canopus... = 53 28 J Sirius = 58 31 • I Capella ... = 54 41 L Aldebaran = 23 30 Length of tail 24°. 17 . Some Account of the Comet, in a Letter from J. Gimblett, Esq. Communicated by Sir John Herschel. 18. Extract of a Letter from Lieut.-Colonel Harvey, 14th Light Dragoons, dated Poona, March 13. Communicated by Professor Narrien. Distance from. LVIII. Intelligence and Miscellaneous Articles. ON THE COMPOSITION OF PECHBLENDE. BY M. EBELMAN. THE author remarks that the uranium in this mineral has hitherto been regarded as identical with the olive-green oxide of uranium, which before the experiments of M. Peligot was considered to be the protoxide ; but it is to be remarked, M. Ebelman observes, that pechblende, even when reduced to very fine powder, retains its deep black colour, as it also does when heated in a current of azote to deprive it of water, whereas if heated to redness in atmospheric air 476 Intelligence and Miscellaneous Articles. "5 it immediately becomes olive-green, and hence it may be concluded that pechblende is not identical with the olive-green oxide. The pechblende from Joachimstal in Bohemia, when treated with hydrochloric acid, yields at first carbonic acid gas, afterwards hydro- sulphuric acid, and eventually dissolves almost entirely, leaving only a little gelatinous silica, entirely soluble in potash. The filtered so- lution was found to contain lead, iron, manganese, lirne, magnesia, and a small quantity of soda. When pechblende is heated in a cur- rent of dry chlorine it yields only chloride of sulphur. Pechblende acted on by chlorine is partly soluble in water, and leaves a yellow residue of urinate of lime and magnesia ; the solution contains neither antimony, bismuth, arsenic, copper, or zinc. To analyse pechblende it was treated with nitric acid ; the silica was separated by evaporating the solution to dryness ; the residue was treated with hydrochloric acid and filtered. The lead was se- parated by hydrosulphuric acid, converted into sulphate and esti- mated ; to the solution after the separation of the lead hydrosulphate of ammonia was added, which precipitated the uranium, iron and manganese ; the method by which these three metals were separated will be presently stated. The solution from which they were pre- cipitated was boiled, then treated Avith oxalate of ammonia, the oxalate of lime converted into sulphate and estimated. The filtered solution was evaporated to dryness, and the residue heated to redness to expel the ammoniacal salts, sulphuric acid was then added, and the sulphates of magnesia and soda were obtained ; the alkali was sepa- rated from the magnesia by means of acetate of barytes. The sulphur was determined by a separate experiment, and its quantity was exactly proportional to that of the lead ; the carbonic acid was expelled by nitric acid, and its quantity determined by that of the carbonate which it precipitated from barytes water. The water is readily separated by heat ; it was obtained by heating the pechblende in azotic gas, and absorbing it by chloride of calcium. The uranium was separated from the iron and manganese by the following means : — the solution of carbonate of uranium in carbonate of ammonia is not rendered turbid by the addition of hydrosulphate of ammonia ; and this fact, which has not been before noticed, allows of the separation of uranium from several metallic oxides slightly soluble in carbonate of ammonia, such as those of manganese, cobalt, nickel and zinc, which hydrosulphate of ammonia completely preci- pitates from this solution : this separation of uranium from the above-named oxides is rendered very simple by this process. In the present case the uranium, manganese and iron having been precipitated by hydrosulphate of ammonia, were redissolved in dilute aqua regia, and the liquor supersaturated with carbonate of ammonia, precipitated peroxide of iron mixed with some manganese ; hydro- sulphate of ammonia added to the filtered liquor separated a little sulphuret of manganese, and it was then boiled till colourless ; the precipitate obtained is greenish, owing to the partial reduction of the oxide of uranium by the hydrosulphate ; it was obtained in the state of green oxide by calcination ; the iron and manganese were sepa- rated by succinate of ammonia. Intelligence arid Miscellaneous Articles. 477 M. Ebelman determined the state of oxidation of the uranium in pechblende, by a modification of a process which he has described in the sixteenth volume of the Annates des Mines, and the results of his analyses are — Black oxide of uranium 75*23 Sulphuret of lead 4*82 Protoxide of iron 3*10 Protoxide of manganese 0*82 Silica 3-48 Lime 524 Magnesia 2*07 Soda 0-25 Carbonic acid 3*32 Water 185 100-18 Ann. de Ch. et de Phys., Aout 1843. ON THE COMPOSITION OF WOLFRAM. BY M. EBELMAN. Until lately wolfram has been considered as a compound of tung- stic acid with the protoxides of iron and manganese ; but recently, M. Schaffgotsch {Ann. de Ch. et dePhys. ii. p. 532) has stated that it contains the oxide of tungsten and not the acid. He has deduced this from the results of his analyses, which all gave an excess of five or six hundredths when the tungsten was estimated as tungstic acid. M. Wohler arrived at the same conclusion from the action of chlorine on wolfram. M. Ebelman remarks, that an experiment which is easy of execu- tion appeared to him to be sufficient to decide the question : wolfram is acted upon by hydrochloric acid when boiling, and leaves a residue which is evidently tungstic acid. The mean of five experiments on wolfram from the environs of Limoges gave the following results : — Tungstic acid 76*20 Protoxide of iron 19*19 Protoxide of manganese 4*48 Magnesia 0*80 100*67 The mean of two experiments made upon fragments of a large crystal of wolfram from Zinnwald, gave Tungstic acid 75*99 Protoxide of iron 9*62 Protoxide of manganese 13*96 Lime 0-48 100*05 Ann. de Ch. et de Phys., Aout 1843. ON THE PRODUCTS OF THE DECOMPOSITION OF AMBER BY HEAT. BY MM. PELLETIER AND PHILIPPE WALTER. The authors remark, that the phsenomena of the distillation of amber have been observed with the greatest attention by MM. Robi- 478 Intelligence and Miscellaneous Articles. quet and Colin {Ann. de Chem. et de Phys., torn. iv. p. 326) ; they state, that when amber is heated in a glass retort it softens, fuses, swells up considerably and yields succinic acid, oil and combustible gases ; as the production of the acid proceeds the swelling up diminishes, and soon ceases altogether. If the fused matter be now examined, it is found to possess an even fracture of a vitreous and resinous aspect ; if, on the contrary, it be heated quickly, it boils rapidly with- out swelling, and produces so large a quantity of oil that it flows in small streams ; lastly, when the matter appears to be so completely carbonized that it yields scarcely any oil, and the retort be then heated till it softens, a yellow substance sublimes which has the con- sistence of wax. If this waxy matter be treated with cold aether the micaceous matter of MM. Robiquet and Colin is obtained, but if it be boiled in abso- lute alcohol, taking care not to use enough to dissolve the whole mass, it will be observed that the portion which does not dissolve is of a much deeper yellow, less micaceous and more pulverulent than the original substance ; it will also be seen that the first portions which crystallize, either by the evaporation or cooling of the aether, is of a much less intense yellow than the original matter ; lastly, by the almost complete evaporation of the aether, a crystalline matter of a still less deep colour is obtained. "When each of these three products is separately treated with al- cohol they behave in the same manner; a very yellow substance which does not dissolve, a less yellow substance which crystallizes first, a still paler substance remaining in the mother-water. Eventually, however, after numerous experiments, the authors ob- tained only two substances ; one in a very small quantity : this was pulverulent, scarcely crystalline, of a fine yellow colour, insoluble in cold alcohol, and scarcely soluble in it or aether when boiling ; the other substance is white, in very fine flattened acicular crystals, more soluble in alcohol and in aether. This last is the true peculiar cry- stalline substance which constitutes the pyrogenous wax of amber ; it is in quantity to the yellow matter insoluble in alcohol as 90 to 10. The authors then state, that by various modes of treatment with alcohol of different strengths and aether, they obtained from heated amber, — 1st, oil; 2ndly, yellow substance ; 3rdly, white crystalline matter; 4thly, a brown bituminous matter, very soluble in alcohol, and possessing the characters of the non-acid pyretin of Berzelius. Yellow substance. — The properties of this are that it is insoluble in water, scarcely soluble in boiling alcohol or aether ; it is rather pulverulent than crystalline ; requires a temperature of 464° Fahr. to melt it ; it then volatilizes, and the greater part of it is decomposed. When heated in nitric acid it is converted into a reddish yellow re- sinous matter. Cold sulphuric acid has no sensible action upon it ; when heated it dissolves it, acquiring a deep blue colour with a shade of green. By analysis it yielded Hydrogen .... 5 '8 Carbon 94-4 100-2 Meteorological Observations. 479 This analysis, and the properties of this substance, prove its iden- tity with that which M. Laurent calls chrysene. White crystalline substance. — This is inodorous, insipid, scarcely soluble in cold alcohol, very sparingly soluble in aether, but more so than the preceding substance ; soluble [fusible ?] at 320° Fahr. ; when heated in close vessels to above 576° Fahr. it is volatilized, a small portion, however, is decomposed with a small residue of char- coal ; it dissolves in the fixed and volatile oils, but the alkalies do not act upon it. The mineral acids when cold do not attack it ; when heated, sulphuric acid dissolves it, and assumes a deep blue colour without any shade of green, and it is soon carbonized. If before this effect is produced the acid be diluted, it becomes colour- less, but recovers its colour by concentration ; by hot nitric acid it is converted into a resinous matter. By analysis it yielded I. II. III. Hydrogen .... 5*6 5*8 5*5 Carbon 95-6 95'3 95-8 101-2 101-1 101-3 From these results the authors are of opinion that this substance is not merely isomeric, but identical with the idrialine of M . Dumas \ and they propose to call it succisterene. — Ann. de Ch. et de Phys. ix. 89. METEOROLOGICAL OBSERVATIONS FOR OCTOBER 1843. CMswick. — October 1. Fine : clear : overcast. 2. Overcast : showery. 3,4. Cloudy and mild. 5. Very fine. 6. Densely clouded : rain. 7. Cloudy: rain. 8. Boisterous : overcast. 9. Rain. 10. Clear : overcast : rain. 1 1 . Boisterous : heavy rain. 12. Boisterous: rain. 13, 14. Clear: cloudy and fine. 15. Foggy: cloudy : frosty and foggy. 1 6. Frosty : clear and cold : frosty. 1 7. Stormy, with rain. 18. Cloudless: clear and frosty. 19. Frosty haze : clear: frosty. 20. Frosty haze : fine : cloudy. 21. Cloudy: showery : clear. 22. Cloudy and fine : stormy at night. 23. Clear : cloudy : clear. 24. Densely clouded. 25. Cloudy : clear. 26. Frosty : very fine : clear. 27. Very fine : boisterous, with rain at night. 28. Boisterous : clear and fine. 29. Hazy : clear : foggy. 30. Hazy : rain. 31. Heavy rain. — Mean temperature of the month 2§° below the average. JJoston. — Oct. I, 2. Cloudy : rain early a.m. 3. Fine. 4, 5. Cloudy. 6. Cloudy : rain p.m. 7. Fine. 8. Cloudy : rain early a.m. 9. Rain : rain early a.m.: rain a.m. 10. Fine. 11. Rain. 12. Rain and stormy. 13. Fine. 14. Windy: ice this morning. 15,16. Fine. 17. Cloudy : rain early a.m. : stormy night, with rain. 18 — 20. Fine. 21. Cloudy: rain early a.m. 22. Cloudy: rain p.m. 23. Fine. 24. Fine: rain p.m. 25 — 27. Fine. 28. Stormy: rain early a.m. 29. Fine. SO. Cloudy: rain early a.m. : rain p.m. 31. Cloudy. Sandwick Manse, Orkney. — Oct. 1. Showers. 2. Showers : clear. 3. Showers: large hail. 4. Rain. 5. Drizzle. 6. Rain : showers. 7. Bright : showers. 8,9. Cloudy : clear. 10. Showers. 11. Frost : showers. 12. Showers : hail. 13. Large hail. 14. Bright: showers. 15, 16. Hail-showers. 17. Snow-showers: clear frost. 18. Clear frost: showers. 19 — 21. Showers. 22. Clear frost : showers. 23. Showers. 24. Showers : sleet : showers. 25. Showers. 26. Showers : aurora. 27. Cloudy : rain. 28. Drizzle. 29. Showers. 30. Showers : fine. 31. Showers : fine : clear. Applegarth Manse, Dumfries- shire. — Oct. 1. Cloudy : rain p.m. 2. Fine. 3. Dull. 4. Cold : dull. 5. Fine : mild. 6. Wet, but mild. 7. Rain. 8. Showers. 9. Clear: fair. 10. Dull : fair. 11. Wet. 12. Cold : snow on the hills. 13. Cold : hail-shower. 14, 15. Fine and clear. 16. Fine : dry. 17. Rain and sleet. 18. Fine: frosty. 19. Clear: fair. 20. Dull: wet p.m. 21. Clear and sunny. 22. Very wet : cleared p. m. 23. Boisterous : showers, 24. Wet. 25, 26. Fine : frost a.m. 27. Fine. 28. Fair : chill. 29. Heavy rain. 30. Fair : frost. 31. 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On Dr. Hare's "Additional Objections" relating to Whirlwind Storms. By W. C. Redfjeld*. T N my reply to Dr. Hare's first series of " Objections " and ■*■ " Strictures," I attempted to show that these could have no. weight or efficacy in disproving the whirlwind character of violent storms and tornadoes; and, furthermore, that con- vincing evidence of whirlwind action in the tornado of New Brunswick was found in those very facts which he had set forth and relied on for disproving its rotation f. Besides correcting, on that occasion, certain grave errors into which my opponent had fallen, I also referred to the ad- ditional proofs of rotation which are found in my published survey of the effects of this tornado J. This was deemed suf- ficiently conclusive in replying to Dr. Hare, who had chosen to " enter the lists " as my assailant and in support of his own and Mr. Espy's notion of the centripetal course of the wind in these storms; for the effects produced by the New Bruns- wick tornado had been greatly relied on by each of these writers, as proving such centripetal course in the wind of tor- nadoes. At that time I possessed, in my field-notes and surveys, abundant evidence of a constant rotative action in several other tornadoes, and plans or diagrams which exhibit portions of this evidence had long been prepared ; but I saw no defect in the proofs of rotation previously shown that required their publication. One of the tornadoes which I had thus prepared to illus- trate, was that which passed near Providence in 1838, some account of which had been published by Dr. Hare; and, as partiality for his own electrical hypothesis may have induced him to engage in this controversy, I now refer to a paper con- * Communicated by the Author, f This Journal for May 1842, p. 353-369. j For this survey, &c. see this Journal for January 1841, p. 20-29. Phil. Mag. S. 3. No. 155. Suppl. Vol. 23. 2 I J& 482 Mr. Redfield's Beply to Dr. Hare's taining what I deem decisive evidence of the whirling cha- racter of the Providence tornado, published since the first ap- pearance, in America, of his " Additional Objections," and found in this Journal for January 1843, p. 38-52. It has probably been perceived, that in advancing his " ad- ditional objections," which are found in this Journal for August last, Dr. Hare seems virtually to abandon the main question of rotation as an issue of fact, as rested on his pre- vious allegations relating to the New Brunswick and Provi- dence tornadoes: for he appears now to rely chiefly, on a petite guerre of criticisms, which have little, if any, relation to definite observations; the only evidence on which the ques- tion really depends. I might justly complain of that apparent want of candour which has prevented Dr. Hare from correcting, in any man- ner, the several mistakes and errors, whether of fact, quota- tion, or induction, which were pointed out, long since, in my reply to his first series of "objections" and "strictures." It is this want of candour in the discussion that seems to demand these defensive notices and remarks, which perhaps are more necessary from the fact that few persons, probably, engage in a careful and strict analysis and comparison of the observa- tions which have been made in storms. Dr. Hare now says he had "endeavoured to point out va- rious errors and inconsistencies in the theory of storms pro- posed by me, or in the reasoning and assumed scientific prin- ciples on which that theory had been advanced." But it has never been my purpose to " propose " or " advance " a " theory of storms " founded on " reasoning and assumed sci- entific principles." This has, indeed, been attempted by others ; with what success is best known to attentive inquirers : whereas I have mainly endeavoured to exhibit a matter-of- fact view of the actual phenomena of storms, so far as relates to their progress, the violent rotative winds which they exhibit, and the effect of these winds on the barometer. Referring to a supposed approval of my views by men of science, Dr. H. says [§ 58], "It strikes me, however, that a fault now prevails which is the opposite of that which Bacon lias been applauded for correcting. Instead of the extreme of entertaining plausible theories having no adequate founda- tion in observation or experience, some men of science of the present time are prone to lend a favourable ear to any hypo- thesis, however absurd in itself, provided it be associated with observations." As already stated, it is "observations" and their results which I have chiefly endeavoured to promulgate. But if it has been attempted to associate a favoured "hypo- " Additional Objections " relating to Whirlwind Storms. 483 thesis," whether " absurd " or otherwise, with observations on storms, I apprehend it has been by my opponents, notwith- standing that the seeming dislike to observations may appear unfavourable to this conclusion. In the same paragraph are alleged no less than three quota- tions in forms of words and connexion such as I did not use ; and at least three following paragraphs of the "additional objections " appear devoted to the unamiable attempt to render me obnoxious to distinguished men, which perhaps may ren- der proper the following statement and explanation. I had incidentally remarked, on the occasion of Mr. Espy's first attempt to discredit certain facts and results which I had stated *, that " the grand error into which the whole school of meteorologists appear to have fallen, consists in ascribing to heat and rarefaction the origin and support of the great atmo- spheric currents which are found to prevail over a great por- tion of the globe." And, in allusion to the views found in Sir John F. W. Herschel's treatise on Astronomy, I also said, " Sir John, however, has erred, like his predecessors, in ascribing mainly, if not primarily, to heat and rarefaction those results which should have been ascribed solely to me- chanical gravitation, as connected with the rotative and orbi- tual motion of the earth's surface, the influence of which he but partially recognizes in connection with this and another subject of inquiry." By the ill-chosen phrase " whole school," was simply meant, all meteorologists to whose writings I had obtained access. It was an inadvertent form of expression, not particularly noticed by me till after publication, and has probably given more pain to myself than to any one else. I have reason to believe that Sir John Herschel has not thought himself accused or denounced in these passing and somewhat hurried remarks. Even if Dr. H. could have succeeded by this ruse in cover- ing his apparent discomfiture on the main question of rota- tion, was it required for the elucidation of science, or consist- ent with the rules of candour and courtesy, that he should persist in repeated efforts to excite an odium in the minds of his readers ? I had pointed out Dr. Hare's error in alleging that I reject the influence of heat on winds. In now repeating this allega- tion [§ 63], he complacently intimates, that "It is very pos- sible that his opinions may have changed since he read my ' objections,' but that he did reject the influence of HEATf * Silliman's Journal, vol. xxviii. p. 316. f In cases of quotation, where it is proper to notice the bearing of par- ticular words or phrases, I adduce these in small capitals, as above. 2 12 484 Mr. Redfield's Reply to Dr. Hare's when the preceding and following opinions were published must be quite evident." And he then quotes, somewhat inac- curately, part of the subjoined extract as sustaining this alle- gation; the correctness, or pertinacious unfairness of which, I shall leave unprejudiced readers to determine from the very evidence to which he refers. I had said in immediate connec- tion with the foregoing, as follows : — " But, to prevent being misunderstood, I freely admit that heat is often an exciting as well as modifying cause of local winds, and other phenomena, and that it has an inci- dental or subordinate action (though not such as is usually assigned) in the organization and development of storms, and that, in certain circumstances, it influences the inter positions of the moving strata of the atmosphere. Its greatest direct influence is probably exhibited in what are called LAND AND SEA BREEZES, Or in the DIURNAL MODIFICATIONS which are exhibited by regular and general winds. But, so far from being the great prime mover of the atmospheric currents, either in producing a supposed primary north and south current, or in any other manner, I entertain no doubt, that if it were 'possible to preserve [this is the part Dr. H. quotes] the atmosphere at a uniform temperature over the whole surface of the globe, the general winds could not be less brisk, but would become more constant and uniform than ever.'" — Silliman's Journal, 1835, vol. xxviii. p. 317. — And with all this before him, he now reasserts that I then rejected THE INFLUENCE OF HEAT It appears to dissatisfy Dr. Hare that I should have deemed the first inquiry to be what are storms'? and not how are storms produced? He asks, " suppose that before ascertaining how fire is produced, chemists had waited for an answer to the question what isjire'i how much had science been retarded?" But, waiving any want of analogy between fire and storms, suppose that in treating of fire one chemist should ascribe it to the heat of combustion, another to the smoke and aqueous vapour evolved, while a third should view it as being caused by electricity; would not the proper inquiry then be, what is fire, and what are its obvious phamomena? It appears evi- dent that the laws and phaenomena of storms must be first as- certained and established, ere we can advantageously investi- gate their origin or primary causes. If Dr. Hare chooses to consider this an endless controversy which he has waged, and that to follow its misunderstandings would be an Ixion task, ought he not to reflect, that grace to acknowledge those "misunderstandings" which it had brought to light would doubtless have shortened its duration? " Additional Objections " relating to Whirlwind Storms. 485 Paragraphs 66 to 70 Dr. Hare has devoted to some super- fluous suggestions found in my earliest paper, 1831, which were virtually withdrawn more than three years since*. He has also joined [§ 68] a passage from that paper with another from a subsequent one, and quotes both as from the latter. The " unresisted rotation " here refers to the seeming non-re- sistance of the air to a body turning on its own axis ; and the rotative velocity of a moving body was correctly viewed as being sometimes " accelerated " by the oblique " resistances " of other bodies. In § 70-73 my opponent labours to convict me of inconsist- encies in passages culled from my reply to Mr. Espy; as if any inconsistencies of mine could disprove the rotative cha- racter of storms. The alleged inconsistencies result from his confounding cases which I view as distinct, and from some inaccuracies in my choice of terms. The like purpose is evinced in § 74-78, with a collection of passages on the baro- meter, where Dr. H. seems to confound the space "around the exterior border " of the gale with its " first portion " and "last portion." In his criticisms on my statements of the changes of wind in storms [§ 79-85], Dr. Hare fails to appreciate the proper distinction between "suddenly" and immediately, in passages which in their original state and connection are perhaps suffi- ciently correct ; and he would make the statement of an ex- ception which " sometimes happens," to be a contradiction or neutralization of the " evidence," or general result. Had he observed carefully he might have found that his fancied ana- logy derived from the rotary action of a solid is entirely in- applicable to the case of natural eddies and whirls, which are produced by a gravitating force acting from the exterior. He might thus have learned that his hypothetical statement of the law of rotation in fluids does not, at least in all cases, agree with fact, and can in no way alter or affect the vorticular or other rotative action exhibited in nature. Nor can he dis- prove or annul the fact, that an immediate or a sudden change takes place at the inner margin of the violent part of a regular and extensive whirlwind storm, at the border of the central lull or remission of the gale. His implied allegation [§ 86] that "there is no evidence" that the wind was more violent on the south-eastern f side of * See note prefixed to my article on Hurricanes in the Nautical Maga- zine for January 1839, and Silliman's Journal, vol. xxxv. p. 201-202. f This I believe to be Dr. Hare's meaning; for the word "south-west- ern," which he here uses, I deem to be a misprint; else Dr. H. fails to un- derstand himself in this passage; for there is nothing in my views, as set 486 Mr. Redfield's Reply to Dr. Hare's the gale of August 17th, 1830, than on its north-western side, is opposed by the testimony of Captain Waterman of the Illinois and by the log-book of the ship, as compared with observations made at the same time on the opposite or north- western side of the gale. It was on or near the central line or axis-path of this storm, that only south-easterly and north- westerly winds were successively exhibited ; a fact which ap- pears quite sufficient to settle the main question between me and my opponents. Dr. Hare infers that " in no case would the inner portion of the south-eastern and more violent limb" of a gale or hur- ricane " be beyond the cognizance of our merchants and in- surers;" and then says, that "experience shows that every north-easter brings in a crowd of vessels having only to com- plain of the violence, not the direction of the wind" [§ 87]. But do the alleged " crowd of vessels " come from for in the south-eastern offing? The storm of August 17th, 1830, was at New York a strong "north-easter'," and would the Illinois, in the Gulf Stream off Nantucket, have found no cause to complain of the " direction of the wind," if bound to New York or Philadelphia? — this ship having had the wind set in at "south" and veering "first to sotcth-west, then to west and north-west" a "perfect hurricane !" "Experience" has shown, in a multitude of cases, that in these violent gales, while blowing north-easterly on our shores, the wind is found more easterly, southerly, and south-westerly, in proportion to the increased distance from the coast. This produces a dan- gerous cross sea; and "our merchants and insurers" have, unfortunately, been too often cognizant of the destructive ef- fects. In [§ 88-91], Dr. Hare has succeeded in showing that a summary passage on the phases of hurricanes in the West Indies, from which he adduces an extract, is not reconcileable with all the local changes in such storms, considered as mo- ving whirlwinds. There are two ways, however, by which this labour might have been lessened or avoided: first, by quoting the next sentence, which suggests qualifications, and second, by referring to the same number of Silliman's Journal [vol. xxv. p. 114-121], where the phases of these gales in the western Atlantic are particularly set forth, together with a key for suiting these explanations to the storms while in West Indian seas, viz. that in the latter region, the direction of the wind, in the corresponding sides and phases of the storms, is forth, or in the nature of the case, that requires the wind to be stronger on the " south-western " side of a storm than on the " southeastern " side, but rather the contrary. "Additional Objections" relating to WJiirlwind Storms. 487 found "about ten or twelve points of the compass more to the left [on the compass card], than on the coast of the United States in the latitude of New York." In the next place, Dr. H. endeavours to show [§ 92-94] that I seem to suppose whirlwinds as capable of being "self- induced." Injustice to his readers, however, he should have quoted the entire paragraph from which he has cited my re- mark, " that whirlwinds and spouts appear to commence gra- dually and to acquire their full activity without the aid of any foreign causes" (Silliman's Journal, vol. xxxiii. p. 61). But can Dr. Hare prove to us "the aid of any foreign causes?" It is proper to note here, that by the above remark I did not intend to exclude the influence of atmospheric pressure and elasticity, nor variations of temperature and density in and about the body in which gyration is induced. Neither do I disconnect or "isolate" the spirally ascending central motion from the great body of the tornado or whirlwinds as he at- tempts to do for me. Dr. Hare finally declares [§ 95], " I do not deem it expe- dient to enter upon any discussion as to the competency of the evidence by which the gyration of storms has been considered as proved." The friends of science may well be surprised at this. For, if Dr. H. did not intend to discuss the "evidence" of gyration, for what useful purpose did he "enter the lists?" or why did he attempt to show facts in disproof? Was it more important to array a series of criticisms and speculations than to bring the question to the test of strict observation and induction? And will not this evasion be received as proof of the weakness of his cause? He says that the competency of the evidence has by Mr. Espy been "ably contested." But has it been so " contested " by that writer, as to be decided adversely in the mind of any strict and careful inquirer, or with such scrutiny and arrangement of the facts alleged as would allow them to speak in their own true language*? Even if Dr. H. should admit gyration to be " sufficiently proved," and "should consider it as an effect of a conflux to supply an upward current at the axis," would not this imply a self-elevating power in this "upward current?" And would not the admission of gyration decide the question in my favour? But he adds further : " Yet the survey of the New Bruns- wick tornado, made on terra Jirma with the aid of a compass, by an observer so skilful and unbiassed as Professor Bache, ought to outweigh maritime observations, made in many cases under circumstances of difficulty and danger." Now let me * Perhaps a partial exception ought to be acknowledged here as relates to one case. See Journal of the Franklin Institute (Philadelphia) for June 1839, p. 372-374. 488 Mr. Redfield's Reply to Dr. Hare's ask, Is gyration disproved by this survey? I trow not; and apprehend that I have sufficiently shown its results to have been accordant with a general rotative action*. Still unwilling to admit rotation, he refers to the storm of December 21, 1836, in the terms which follow. " In like manner great credit should be given to the obser- vations collected by Professor Loomis respecting a remarkable inland storm of December 1836. This storm commenced blowing between south and east to the westward of the Mis- sissippi, and travelled from west or north-west to east or south- east, at a rate of between thirty and forty miles per hour [?]. There appears to have been within the sphere of its violence an area, throughout which the barometric column stood at a minimum, and towards which the wind blew violently on the one side only from between east and south, and on the other only between north and west [?]. This area extended from south-west to north-east more than two thousand miles. Its great length in proportion to its breadth seems irreconcilable with its having formed the axis of a whirlwind [!]. The course of this storm, as above stated, was at right angles to that attributed by Redfield to storms of this kind [!] . (Trans. Am. Phil. Soc. vol. vii.)" We have it here asserted that ** this storm " . . . " travelled from west or north-west to east or south-east:" and that "the course of this storm, as above stated, was at right angles to that attributed by" me to other storms; while at the same time we are told that the area, " throughout which the barometric column stood at a minimum," . . . "extended from south-west to north-east more than two thousand miles." Now, in all storms which I have noticed in this part of Ame- rica, the course and progress of the barometric minimum ap- pears coincident with that of the body or axis of the storm ; and as the length of the track thus passed over is quite a di- stinct thing from the length of the storm itself, or from the "area" of the barometric minimum at any given moment of time, it appears to follow from Dr. Hare's own statement, that the course of the proper body or axis of the gale was north- easterly ; coinciding with the course of other storms. More- over, I have not yet seen any evidence which shows that even one storm of magnitude in the United States has proceeded in a south-easterly course; although such a conclusion has been suddenly adopted, ere uowf? apparently with the hope of escaping from a difficulty in which some favourite hypo- thesis had become involved. • Article on the New Brunswick tornado, in this Journal, January 1841, p. 20-29. f Not, however, by Prof. Loomis. "Additional Objections" relating to Whirlwind Storms. 489 I am aware that Professor Loomis alleges, in his elaborate account of this storm and its attendant phaenomena, which I greatly value, although dissenting from some of his conclu- sions, that " in this case there was no whirlwind." I will only remark, that to me the characteristics of this storm appear to be those of a diffused overland gale of the whirlwind cha- racter; the only observations obtained being evidently on the right-hand of the path of its axis. I understand, also, that other inquirers have been led by the evidence to the same result. The manner in which Dr. Hare has described this storm, and his erroneous allegation in regard to its course, show very strongly the importance of the inquiry, What are storms'? For, was it the area of the minimum depression of the barometer — or the area of violent winds — or the area of the rain — or the area passed over by the wave of barometric oscillation — or the area of extraordinary changes of temperature — which consti- tuted the proper limits or identity of this storm*? Those readers who may desire to ascertain the general course of the wind in the body of a great storm, without re- sorting to a process of induction from characteristic facts on one hand, or to the aid of ingenious hypotheses which regard certain alleged but unknown movements of the air in connec- tion with the higher atmosphere on the other, are referred to a schedule and map of observations made at about forty sepa- rate localities, at the hour of noon, in the storm of December 1839, which are found in this Journal for January 184-1. These observations are believed to exceed in number and ac- curacy any that have yet been obtained in equal limits, and they are arranged on the map so as to speak their own proper language as simultaneous observations f. Hence they appear to show conclusively, that the violent easterly winds in this American storm were resolved, through a circuitous geogra- phical course, into the strong north-westerly winds which im- mediately followed the easterly part of the gale; instead of mounting to unknown regions, before opposing winds, as has been alleged by others. * So far as definitions only are concerned, and these are important in science, it may be proper to adduce the following from Webster, the lexi- cographer : — " STORM, n. A violent wind; a tempest. Thus a storm of ivind is correct language, as the proper sense of the word is rushing, violence. It has primarily no reference to a fall of rain or snow. But as a violent wind is often attended with rain or snow, the word storm has come to be used, most improperly, for a fall of rain or snow without wind." f For more extended remarks relating to these observations, see Silli- nian's Journal for April 1842, p. 112. 490 Mr. Redfield's Reply to Dr. Hare on Whirlwind Storms. The arrows marked on the small geographical sketch which is here annexed, show the direction of wind at some of the princi- pal points of observa- tion eastward of the Hudson river, near the close of the day, when the body of the storm was further ad- vanced in its north- easterly course. The concentric lines, drawn at intervals of thirty miles, are de- signed to afford better means of comparison for the several obser- vations. The observations which I have obtained of this storm, and its remote effects, are far more extensive to the southward and eastward than the limits of the map ; showing also that in this portion of the storm, the winds in the early part of the gale were blowing from south-easterly and southerly quarters. It is worthy of remark, that if only those observations which are southward of the par- allel of Long Island had been obtained and considered, this storm would appear to show an inequality in its phases and an absence of violent north-easterly winds, similar to what is found in Professor Loomis's account of the storm of December 1836, which he was led to pronounce as no whirlwind. The observations on the map referred to have a further value, inasmuch as they belong to a case which Mr. Espy has exhibited as one of his inward and upward blowing storms; for they show, on a strict comparison and investigation as to time and locality in the storm, that, besides inaccuracies, the coup d'ceil of the observations delineated in his diagrams is illusory, and gives to consecutive winds, which follow each other over the same localities, or in different parts of the storm's path, the appearance of simultaneous and opposing winds, blowing in opposite courses towards each other. In the case of tornadoes it is necessary to resort to a pro- cess of induction to determine both the relative positions in the tornado of the several fallen bodies at the instant of their Mr. Fox's Experiments on Subterranean Electricity. 491 prostration, and the general character of the prostrating force which these may conjointly indicate. The course of induc- tion suggested in my two papers on the tornadoes of Provi- dence and New Brunswick, as taken together, are believed to afford sufficient grounds for a correct determination, when applied to the traces of other tornadoes. It is also satisfac- tory to find, that in the surveys exhibited in the above cases there are several traces of individual objects moving in the tornado, which fully confirm the accuracy of the more general induction. As regards Dr. Hare's own views of the electrical origin of storms, some notice has been taken of these in Silliman's Journal for October 1842, p. 261-263. Since the discoveries of Franklin, an electrical origin and character has often been conjecturally ascribed to storms. A want of originality in advancing this hypothesis will not weaken any evidence which shall be adduced in its favour; but until it shall have been satisfactorily supported by observed phamomena, it will pro- bably continue to be rejected by scientific inquirers. And were it possible to show an electrical origin in great storms and tornadoes, it would in no wise alter the known fact that a de- terminate rotative action has been noticed in these storms. LX. Notice of some Experiments on Subterranean Electri- city made in Pennance Mine, near Falmouth. By R. W. Fox, Esq.* I HAVE already communicated to the Geological Society of London t some results produced by the electric action of two nearly east and west metalliferous veins which have been partially explored in Pennance mine. I have since made other experiments in the same mine, in which ore-points, consisting of copper and iron pyrites in the two veins, were connected by a pair of copper wires, which in most instances acted on a galvanometer or other apparatus at the surface, an end of each wire having been brought up through a shaft for the purpose; about 50 fathoms of wire were employed, although the ore- points in the different veins were only about 14 to 18 fathoms asunder in a direct line. A galvanometer of not much sensibility was generally used ; the needle, which was 2| inches long, moved on a pivot, and had a coil of fine wire passed 48 times round it. Another galvanometer, consisting of a suspended astatic needle and 140 coils of wire, was also employed occasionally. * From the Transactions of the Royal Cornwall Polytechnic Society. f The communication here alluded to will be found in our report of the proceedings of the Geological Society, pres. vol. p. 457. — Edit. 4-92 Mr. Fox's Experiments on Subterranean Electricity When the former, which call No. 1, was placed in the cir- cuit, the needle was deflected so as to become stationary at 14° to 15° from zero; and it revolved rapidly round the circle when the circuit was broken and restored a few times, the direction of the electricity being from the south vein to the northern one. The other galvanometer (No. 2) suffered a permanent deflection of about 40° when in the circuit. The interposition of a plate of platinum or zinc at either of the ore- points, or of a point, instead of a considerable surface of me- tal, did not affect the direction or force of the currents; they were, moreover, constant in both these respects during more than eight months that the two veins were connected by the wires, and a part of this time the mine was filled with water in consequence of an accident to the machinery. Ore-points in the two veins situated within two or three feet of the others respectively, were at one time connected by a second pair of copper wires of the same lengths as the first ; both sets of par- allel wires being kept apart, and insulated from the sides of the levels or galleries by poles stretched across the latter at short intervals. When galvanometer No. 2 was placed in the second cir- cuit, No. 1 remaining in the other, the needle of the latter re- ceded at least 2°, standing at 12°, instead of 14° or 15°; and the former stood at 5° or 6° less than it did when only one circuit was established. On breaking either of the circuits, the deflection of the needle in the other circuit was increased to its original amount; and when both pairs of wires were con- nected with only one of the instruments, the effect was almost precisely the same as that produced by one pair alone, — not greater certainly. A copper and zinc pair of plates of about 6 inches surface, separated by a piece of cotton cloth moistened with water, was placed in the circuit, and when the currents from this source and the veins coincided in direction, the needle of galvano- meter No. 1 stood at eibout 10°, that is, at less than it did when acted upon by the subterranean electricity alone, and when the deflection caused by the latter was afterwards op- posed by the action of the plates, the needle went back to zero, and even sometimes passed a little beyond it in the op- posite direction. These anomalies may perhaps be referred to the low conducting power of the moistened cotton, which, small as its thickness was, very probably interrupted the trans- mission of the electricity more than the 14 or 18 fathoms of strata or "Country." On taking the voltaic elements from the circuit and con- necting them with the galvanometer, so as to form a separate made in Pennance Mine. 493 circuit acting in an opposite direction to the electricity from the mine, the deflection showed a difference in favour of the latter, and indeed this was the case when the interposed cloth was moistened by a very weak solution of common salt. The electro-magnetic and decomposing effects of these sub- terranean currents also afforded unequivocal evidence of their energy. A helix of copper wire fixed round a small horse- shoe-shaped bar of iron, was placed in the circuit formed by the wires from the veins, when the bar became so magnetized as to cause a compass needle l| inch long, at the distance of nearly half an inch, to oscillate through an arc of about 70°, when the circuit was alternately made and broken a few times. A solution of hydriodide of potash was found to have been decomposed after it had been left in the circuit for rather more than a day. The endosmose action occurred in various experiments, but it may be sufficient to give one example. Sulphate of copper in solution was put into both branches of a U-shaped glass tube with clay in the bent part of it, the surface of the fluid in one branch standing half an inch above that in the other. A piece of silver wire was plunged into each of them, the upper end passing out through sealing wax, with which the extremi- ties of the tube were stopped, and the apparatus was placed upright in the circuit, with the wire in the higher column of the fluid connected with the negative wire. In the course of a few days this column was found to have risen one-eighth of an inch, the other having fallen in an equal degree, showing that the greater pressure of the higher column was superseded by the force of the electric action. When small cylinders of copper pyrites were substituted for the silver wires in the branches of the bent tube, not only did the endosmose action occur, but the copper ore, forming the negative pole, had its surface gradually changed to vitreous copper in the course of two or three days*, the other ore-pole remaining unaltered. The same change was produced, and apparently with equal facility, when solutions of other salts, as carbonate of soda or common salt, were substituted for that of sulphate of copper in both branches of the tube. The cylin- ders of copper pyrites used in these experiments were long enough for the upper ends to project above the mouths of the tube, where the opposite wires were attached to them respect- ively, and these were well coated with sealing-wax dissolved in alcohol, to prevent the access of moisture to any part of the metal, and indeed all but the lower portions of the ore were coated in like manner. * Some of the ore thus changed was at the last Polytechnic Exhibition. 494 Mr. Fox's Experiments on Subterranean Electricity In some instances the cylinders of copper pyrites were al- lowed to remain in solutions of sulphate of copper in the bent tube for several weeks, when deposits of oxide of iron were found coating the inside of the tube about the negative pole. These results remind one of the ochrey appearance observed in rocks inclosing much vitreous copper, a fact noticed by my friend Joseph Carne ; and it may be worth while to inquire how far the proportion of "gossan" in copper veins may be connected with the quantity of vitreous ore contained in them. Since the foregoing experiments were made, I have obtained an electro-type copper plate J^ inch long, l£ wide and J$ of an inch thick, by the agency of these subterranean currents. The apparatus consisted of a porous earthenware vessel, rest- ing on wooden legs in a larger one; both were partly filled with solutions of sulphate of copper, an engraved copper plate attached to the negative wire being placed in the outer vessel, and another plate of copper attached to the positive wire in the inner one. After a few days it was observed that crystals of copper had been formed on the negative plate, but it was nearly two months before the apparatus was removed from the circuit, when the deposited metal was detached from the plate, having received its impression, vi insita terr^. Whilst this experiment was in progress at the surface, the water, as I have before mentioned, invaded the mine, but without inter- rupting the process ; it appeared, indeed, that the electric ac- tion was rather increased than diminished by this circumstance. Before the influx of the water, an ore-point in the north vein was connected with rock near the south vein (generally the wall of the vein), and an ore-point in the south vein was like- wise connected with rock near the north vein, in both which cases currents more or less feeble were detected passing to- wards the latter through the wires, which were insulated, as before, by wooden poles stretched at intervals across the gal- leries. It is probable that the moisture on the rocks con- ducted the electricity from the ore to the metal, however im- perfectly, and when different metals, as platinum and zinc, were successively substituted for the copper in contact with the rocks, the currents were modified in their force according to the metal employed, but were seldom changed in their di- rection. The action was most decided when the place of con- tact with the rock was near ore ; and sometimes the end of the wire, or rather the piece of copper attached to it, was rubbed by an assistant against the walls of one of the veins or the sides of a "cross-cut" between them. Under these circumstances the astatic needle was several times suddenly much deflected, and the parts of the rocks from which this increased action made in Pennance Mine. 495 proceeded having been marked, they were broken away, when iron pyrites was in every instance found imbedded in them ; and there can be no doubt that the smallest branch of copper or lead ore might have been detected in like manner. On several occasions the ends of the opposite wires were placed in contact with the rocks near the two veins, when there still appeared to be a tendency in the currents to pass in the same direction, but often they could not be detected, or were too feeble for their direction to be determined with certainty. Pieces of copper pyrites attached to the wires and imbedded in wood, were likewise used instead of the metal for producing contact with the rocks, and with still less effect; and when the contact was made with platinum and zinc in succession, the currents were in opposite directions, and in accordance with the action of those metals respectively ; so that the existence of independent currents under the circumstances described, though more than probable, was not clearly proved. Electri- city, generated by a pair of zinc and copper plates, was trans- mitted through the rocks between the two veins from north to south, and also from south to north, in order to detect any in- dependent currents traversing the rocks by a differential effect on the needle. This method appeared likely to be a very delicate test of electric action in rocks, but no decided results were obtained, the currents passing in opposite directions ap- parently with equal facility, at least the few experiments hitherto made in this way have not led to any satisfactory conclusions relative to the point in question. It should be remarked, however, that the astatic needle employed was in- conveniently sensitive, and was often set in motion when the cause was not very obvious. With needle No. 1 the case was widely different, as it could scarcely be moved by any subterranean currents that were not tolerably energetic, such as were produced when both the wires were in contact with ore-points, and then, as has been stated, it often revolved rapidly. It has been long known that electric currents will traverse a very considerable thickness of rock or strata*; but in what degree this property may be modified by the nature or tex- ture of the rocks, the saline contents of the subterranean water, or the proportion of ores included in the circuit, remains to be ascertained. If the influence of these different circum- * Many instances of this occur in my paper " on the electro-magnetic properties of metalliferous veins," published in 1830, in the Phil. Tran- sactions, p. 399. I have long ago seen a very feeble current act on a sen- sitive galvanometer after it had traversed nearly a quarter of a mile of strata, and stronger currents would probably be detected in like manner after having passed many times that distance under the surface. 496 Mr. J. Denham Smith on the stances should greatly vary, electric currents generated by given elements might be rendered available on various occa- sions;— to ascertain, for instance, the connection of saline springs not very distant from each other, often appearing at the surface or in mines; or of a metalliferous vein discovered in one place, with a vein which has been worked for ore in another. The conducting power of the circuit at Pennance mine, already described, was in this way found to equal that of a tolerably strong solution of common salt, the current in the latter experiment having to traverse an inch of the solu- tion and short copper wires to complete the circuit. The conducting power of the rocks or strata in this case, there- fore, appeared to be very great. When some sulphate of copper was added to the solution, the conducting power of the latter exceeded that of the strata. Glass tubes filled with solution of salts in different known proportions might be used as tests in experiments on the re- lative conducting power of different strata, and they might be referred to as standards in describing the results. LXI. On the Constitution of the Subsalts of Copper. — No. I. On the Subsulphates. By J. Denham Smith, Esq.* r|1HE results of several analyses of some of the basic salts ■* of copper made at a former period not agreeing with the constitution ascribed in many instances to these compounds, again directed my attention to their composition, and further experience has confirmed this disagreement, showing either that the anal v tic results are in one case incorrect, or that the composition of these salts, prepared at various times by the same method, is not constant. The mode adopted for determining the composition of the subsulphates of copper, was to dissolve one portion of the salt in pure hydrochloric acid, and ascertain the quantity of sul- phuric acid by a salt of barytes. To estimate the proportion of black oxide of copper, the course pursued in the experiments alluded to, was solution of another portion of the salt, under examination, in dilute sulphuric acid and precipitation by a caustic alkali from the boiling solution, carefully washing, ig- niting, and weighing the precipitate. This mode, however, is open to the objection of the possible adherence of portions of the precipitant, or other foreign matter, to the oxide ; and as I subsequently found that this class of salts when exposed to a lengthened and bright ignition, care being taken not to fuse the oxide, loses the whole of its sulphuric acid, I adopted * Communicated by the Chemical Society; having been read April 4, 1843. Constitution of the Subsalts of Copper. 497 this latter mode of estimating the oxide, it being one which appears to me free from objection : I would remark that the residual oxide after this ignition was always examined for sulphuric acid, and if any was detected the experiment was rejected. The deficiency of weight between that of the salt operated on and the sum of the sulphuric acid and oxide of copper, was estimated as water. This method of estimating the water may be objected to as an indirect one, but I consider it more likely to be correct, where a substance possesses so simple a composition as in the case of these subsulphates, than any mode would be that could be devised of actually obtaining and weighing the water; especially as these salts were thoroughly washed until no soluble matter could be detected in the washings, and dried either in a water-bath or on a porous stone, and expo- sure to the atmosphere at the temperature of the laboratory, 50° to 80° Fahr. In those instances where the results of my analyses were not in accordance with those cited by Berzelius, Graham, Kane, Thomson and others, the examination was at times repeated, sometimes thrice, and the mean of these analyses taken in estimating the composition of the salt. The modes of preparation and the constitution of these salts I shall clas- sify in the order of their composition, and at the same time notice discrepancies, when such occur, between my results and those of the analysts who have preceded me. Trisulphate of Copper. — By boiling an equivalent of oxide of zinc and two equivalents of sulphate of copper together, the subsulphate noticed by Berthollet, of a bright green co- lour with a shade of blue, is obtained. The mean of two ana- lyses gave, from 50 grs. of this salt, 33*97 grs. of sulphate barytes and 34T3 grs. of oxide of copper. The composition deduced from these results would seem to indicate the for- mula 2S03 6CuO, 3HO; but I am inclined to consider this salt as really consisting of SOa 3CuO, 2HO, a constitution almost exactly borne out by the second of these analyses, agreeing more nearly with Brunner's analysis of the subsul- phate obtained in this way, and also with the composition of some subsulphates prepared in a different manner, but which indicate the composition S()3 3CuO, 2HO, which will give — Theory. Experiment. Sulphuric acid . . . 1 1'24- 11*65 Oxide of copper . . . 33*72 34*30 Water 504 4*05 50*00 50*00 By precipitating 250 grs. of crystallized sulphate of copper Phil. Mag. S. 3. No. 155. Snppl. Vol. 23. 2 K 498 Mr. J. Denham Smith on the with excess of potash, washing the brownish-black precipitate with hot water until free from alkali, and boiling this with 250 grs. of sulphate of copper, a light green-coloured powder was produced, the boiling and digestion were continued for forty-eight hours, and the liquor was then evaporated to dry- ness. The mass was treated with water to dissolve out uncom- bined sulphate, and washed until free from soluble matter; this when dried gave a pale green powder weighing 172 grs. : of this — 36*32 grs. gave 23*8 grs. of sulphate barytes = 7*35 of sul- phuric acid in 32*52 grs., which quantities afforded by igni- tion 21*56 grs. of oxide of copper; this indicates the formula S03 3CuO, 2HO, or 32*52 grs. consist of Theory. Experiment. Sulphuric acid ... 7*31 7*35 Oxide of copper . . . 21-94 21*56 Water 3*29 3*61 32-52 32*52 This salt is also obtained when less than an equivalent of oxide of copper is boiled with an equivalent of sulphate of copper. In Dr. Kane's tabular view of the sulphates of copper (Transactions of the Royal Irish Academy, &c, vol. xix.), this salt, the trisulphate of copper, is not noticed ; but Ber- zelius has described one, assigning to it 3 equivalents of water. If such a salt exists I have been unable to obtain it ; and although I admit that such a composition is by no means im- probable, seeing that another subsulphate exists in which the number of equivalents of water and oxide of copper are equal, I am inclined to consider that the third equivalent of water in Berzelius's salt was hygrometric, as in no one instance, although this salt was prepared at several distinct periods and in the mode described by Berzelius, did I obtain results indi- cating an approximation to the constitution S03 CuO, 3HO. The composition I have assigned to this salt agreed with that quoted by Dr. Thomson, as arrived at by Brunner from the analysis of the subsulphate prepared by Berthollet's pro- cess. Tetrasulphate of Copper. — This salt is obtainable in a great variety of ways. It is precipitated when a cold solution of sulphate of copper is mixed with an insufficient quantity of carbonate or of caustic soda, or potash to completely decom- pose it. It may be prepared by digesting together cold, — equi- valents of sulphate of copper, and of well-washed precipitated oxide of copper ; by adding a solution of potash to a warm solution of sulphate of copper until a greenish-blue precipi- Constitution of the Sabsalls of Copper. 499 late falls, and no copper remains in solution; by treating a cold solution in the same manner; by acting on the ammo- niacal sulphate by a large quantity of water, &c. Numerous analyses of this salt, prepared by the various processes above mentioned, have only served to confirm the correctness of the formula, S03 4CuO, 4HO, assigned to it by Professor Graham and Dr. Kane ; it is therefore useless to quote any of these results. Dr. Kane, in the paper before mentioned, states that "this salt when heated does not lose water until the temperature rises above 300° Fahr., but then loses all." I find, however, by exposing this salt to a temperature of 400° — 470° Fahr., that it assumes a grass-green colour accompanied with the evolution of water. When 43*2 grs. of the dingy greenish-blue powder, ob- tained by digesting an equivalent of precipitated oxide of cop- per with an equivalent of sulphate in the cold, were exposed to the above temperature, it changed to a decided green co- lour and lost 1*63 grs., this is equal to 8*9 grs. of water from 236, the equivalent number of the tetrasulphate of copper, which indicates SOa 4CuO, 3HO as the constitution of this green subsulphate. 27*07 grs. of the blue subsulphate became of a grass-green colour and lost 1*04 gr. of water, equivalent to 9*07 grs. from 236 grs., and indicating the formula SOa 4CuO, 3 HO as the constitution of this green subsulphate, arising from the loss of an equivalent of water by the blue subsulphate, SQ3 4CuO, 4 HO. This green salt on analysis gave from 13*43 grs. 9*4 grs. of black oxide of copper, and 6*05 grs. of sulphate barytes from 1 1*62 grs., proving its composition to be as above stated, S03 4CuO, 3HO, or, Sulphuric acid . . Oxide of copper . . Theory. 2-37 9*47 Experiment. 2-4 9'4 1-63 13-43 13-43 This salt is similar to that analysed by Brunner, obtained by boiling equivalents of sulphate of copper and sulphate of potash together, until after repeated washings and boiling no sulphuric acid could be detected in the solution. When this green salt is moistened, or even boiled with water, it does not change colour, nor re-combine with the equivalent of water it had lost, as I had anticipated from the statement of Dr. Kane, that " at a temperature above 300° it loses all its water, and the brown powder, if exposed to the air, re-absorbs water slowly ; if moistened it combines with 2K2 Theory. Experiment. 4-79 4-51 19-19 19*33 5-40 5'54 500 Mr. J. Denham Smith on the the water, rapidly evolving heat, and regains its original pro- portion, and also its proper colour." There exists another hydrate of the tetrasulphate, obtained by precipitating a very dilute solution of sulphate of copper by a solution of potash, also much diluted, adding the alkali until the supernatant fluid restored reddened litmus to blue ; this when dried was an extremely light powder of a very pale blue colour, altogether differing in appearance to the other tetrasulphates ; 18'63grs. of this salt gave 8*28 grs. of sul- phate of barytes, and 29*38 grs. afforded 19*33 grs. of black oxide of copper, indicating the formula S03 4CuO, 5HO, or Sulphuric acid . . Oxide of copper Water 29*38 29*38 Pentasulphate of Copper. — This salt is obtained when potash is added to a solution of sulphate of copper, until the alkali is slightly in excess and a light blue-coloured precipitate is obtained ; this, unless rapidly washed, becomes gradually dingy, and finally turns to a dark greenish-black colour, pro- bably owing to the loss of combined water. This change often takes place, entirely or partially, during the drying of the precipitate, even when dried by exposure to air, without arti- ficial heat; when obtained free from this blackening effect it is a light powder of a blue colour, a more decided tint than that of the tetrasulphate with five equivalents of water; upon analysis, which was frequently repeated, the constitution of this salt was found to be SOa 5CuO, 6 HO. The results of two analyses of this salt, prepared at different times, are sub- joined: 32*2 grs. of the salt gave 21*6 grs. of oxide of copper, and 22-36 grs. gave 9*74 grs. of sulphate barytes, or Theory. Experiment. Sulphuric acid . . . 4*38 4*83 Oxide of copper . . 21-90 21*60 Water 5'92 5*77 32*20 32-20 24*3 grs. gave 16*47 oxide copper, and 17 grs. gave 6*52 grs. sulphate of barytes, equal to Theory. Experiment. Sulphuric acid ... 3*31 3*2 Oxide of copper . . 16*53 16*47 Water ...... 4*46 4*63 24*30 24-30 32*2 grs. heated on a sand-bath until it assumed an olive- Constitution of the Subsalts of Copper. 501 green tint lost 2* grs., and 36*1 3 lost 2*2 grs. of water, equiva- lent to 2 equivalents of water from 294, the equivalent num- ber of the pentasulphate of copper, SOs 5CuO, 6HO, thus altering its constitution to the formula SOa SCuO, 4 HO. Besides the subsulphates of copper already described, two others are stated to exist, a disulphate and an octosulphate of copper. Dr. Thomson describes the first, the disulphate, as produced " when crystals of the blue sulphate are dissolved in water and the solution boiled for a long time with a quan- tity of black oxide of copper, equal to that contained in the salt," and states it to consist of SOa 2CuO, but gives no water as a constituent of it. L. Gmelin, on Thomson's au- thority, directs that equal equivalents of the sulphate and oxide of this metal be digested together for some months to obtain the green disulphate. I tried both these plans ; by boil- ing, at various intervals during ten weeks, equivalents of sul- phate and oxide, I obtained the trisulphate of copper, SOa 3CuO, 2HO, a green-coloured powder; by digesting an equi- valent of each for thirteen weeks the tetrasulphate, SOa 4CuO, 4HO, was produced; even when excess of sulphate of copper was boiled with the precipitated and washed oxide still the subsulphate, SOa 3CuO, 2HO, was formed ; and when in ad- dition to these unsuccessful attempts to obtain it, the modes described being so distinct and easy of execution, we take into consideration that water is not mentioned as a constituent of this disulphate, which is also described as a green-coloured powder, — and no salt of copper whatever is known that pos- sesses a green or a blue colour unless water be present — I am compelled to deny the existence of Thomson's disulphate. Of the non-existence of the octosulphate of Dr. Kane I am not prepared to speak so decidedly ; the evidence of the exist- ence of such a salt is so complete and circumstantial, that on a prima facie view of the description and analysis of this salt in the paper " On the Compounds of Ammonia," it almost compels belief. The production of this very singular salt is dependent, according to Dr. Kane's description, upon " the quantity of alkali employed in the precipitation ; where potash had been used, there were two distinct precipitates produced, the one the bluish-green generally described, the other ' the octosulphate' of a clear grass-green, resembling that of hy- drated oxide of nickel. When ammonia was employed the former alone was produced, and the formation of the latter was found to occur where the whole of the copper had been thrown down, but the liquor had not yet begun to react alkaline It was found in the first instance accidentally, but I have since seldom failed in preparing it completely pure." The process 502 Mr. J. Denham Smith on the thus laid down I have followed; and have tortured it in every way, using hot and cold, weak and strong, solutions — adding potash till the solution was perfectly neutral, and also until it became distinctly alkaline, but all to no purpose ; I could in no way, nor in a single instance, obtain a salt containing less sulphuric acid than the pentasulphate^ SOa 5CuO, 6 HO. When an excess of alkali was added, the precipitate would often change to a greenish-brown tint, but all my efforts to obtain the green salt described by Dr. Kane were fruitless. The composition assigned to this salt, S03 8CuO, 12HO, is a most singular and extraordinary one, and on account of this singularity it deserves considerable attention; if a portion of this salt be sent to me I will submit it to analysis, and should it really be found to exist, shall be happy to bear witness to that effect ; but at present must confess that I do not believe in its existence. I perhaps may be pardoned the suggestion, but it is not impossible, if the solution of potash was not quite free from carbonic acid, that a mixture of subsulphate, hydrate, and carbonate of copper might be obtained, which on analy- sis, reckoning the carbonic acid expelled by the second heat- ing with spirit lamp as water, would afford results closely approximating to such a constitution as S03 8CuO, 12HO. On a review of these subsulphates, the question respecting the function of the water contained in them naturally presents itself, and it is one well worthy consideration on account of the highly distinguished authorities who have advocated par- ticular theories on this subject, which at present are usually admitted, or at least are not disputed. Professor Graham, in the paper " On the Constitution of the Oxalates," &c. &c, seems to decline the question, for speaking of the subsulphates of copper and zinc, he says, " When most successfully prepared they were found to con- tain four atoms of metallic oxide to one of acid (instead of three atoms of oxide, as M. Berzelius supposed)." Berzelius supposed rightly, there is a trisulphate, " together with four atoms of water. I have not hitherto been able to form a di- stinct idea of their constitution, or to decide between differ- ent views which may be taken of it ;" yet in the previous page Mr. Graham writes, " In a former paper upon water as a constituent of sulphates, I examined particularly the constitu- tion of hyd rated sulphuric acid and of the sulphates of the magnesian class of oxides" (copper is included in this class). " All these salts contain one atom of constitutional water;" and again, " all salts are neutral in composition." Now it appears to me that if these two laws be true, that not only should all these subsulphates of copper lose all their com- Constitution of the Subsalts of Copper. 503 bined water save one equivalent, but also, as all salts are neutral salts, that water replaces sulphuric acid with the oxide of copper, thus playing the part of an acid, or vice versa; the first view is not borne out by experiment, and the second ex- hibits either water or oxide of copper in a new and singular point of view, as possessing both basic and acid characters; in sulphate of water or sulphate of copper, a base; in the sub- sulphates of copper, either the water or the oxide of copper, an acid. Whether the true meaning has been attached to the laws quoted as laid down by Mr. Graham, I am un- able to say. If I have misunderstood his meaning, the mis- statement has been unintentional, and is owing to having ac- cepted these sentences for what they express, viz. that all sulphates of the so-called magnesian class of oxides contain an atom of constitutional water, and that all salts are neutral. I presume, however, that the subsulphates of copper will be added to the already somewhat long list of specified exceptions to this latter law. In his ' Elements of Chemistry,' p. 169, Mr. Graham, speaking of subsalts, says, " The compounds of the present class appear to be salts which have assumed a fixed metallic oxide in place of this water," that of crystalli- zation, " they may therefore be truly neutral in composition, the excess of oxide not standing in relation of base to the acid." And this passage surely bears out the meaning I have attached to the former expressions, and is wholly incompati- ble with the observed facts relative to the subsulphates of copper; for under this view there should be but one, viz. SOs HO + 5CuO, corresponding with the crystallized blue sulphate of copper, a compound at present not known to exist. I now come to Dr. Kane's views on this point. In the paper already referred to, he likewise assumes as a " general principle that the transition from the neutral to the basic con- dition in salts takes place by the replacement of water by me- tallic oxide, has, as I conceive, received the fullest confirma- tion." This is clear and distinct, but I submit that this " ge- neral principle" is overthrown by what we have seen to be the constitution of the various subsulphates of copper. Fur- ther on it is stated, that " a. great number of circumstances conspire to render the derivation of the basic sulphates of the magnesian class, from the neutral condition, exceedingly complicated. Thus the neutral salts crystallize with quantities of water variable within very extensive limits, and the pro- portion of metallic oxide by which it may be replaced is sub- ject to variations equally wide : moreover, the replacement of the water by metallic oxide may be but partial, and hence the 504 Mr. J. Denham Smith on the Subsalts of Copper. different hyd rated conditions in which the basic salts exist. From these causes may be deduced the possible existence of a very extensive series of basic sulphates varying considerably in type, and subject only to the one restriction, that in all their different conditions the sum of the equivalents of water and metallic oxide shall always be equal to the sum of the same constituents in some one of the forms in which the neutral salt may crystallize." To show how far the "one restriction" of this law holds good with the subsulphates of copper, we find that the blue and the green crystallized neutral sulphates of copper contain respectively 1 equivalent base and 5 water = 6 equivalents of water and metallic oxide to one of acid, and I equivalent of oxide and 1 equivalent of water equal to 2 equivalents to one of acid, whilst the subsulphates contain respectively five, seven, eight, nine, and eleven equivalents of oxide and water together, combined with one of acid ; thus in no one instance do the subsulphates of copper agree with the law laid down by Dr. Kane for regulating the constitution of basic sulphates. True it is that Berzelius assigns the com- position S03 3CuO, 3HO equal to 6 equivalents of water, and metallic oxide to one of acid ; but, as has been before stated, I believe one of these equivalents of water to be hygro- metric, and that its true constitution is SOs 3 CuO, 2 HO. Being thus compelled to differ from those distinguished chemists who have preceded me in these inquiries into the constitution of subsalts and of the subsulphates of copper, I would submit the following idea of the constitution of this class of salts, at the same time distinctly refusing to draw any general conclusion from a rule which I only know is in ac- cordance with observations upon one particular class of salts. I consider the subsulphates of copper to exist as anhydrous sulphate of copper combined with two or more equivalents of hydrated oxide of copper; these compounds, in most in- stances, unite with definite proportions of water, precisely in the same manner as some neutral and acid salts combine with water of crystallization, which like them they part with at stated elevations of temperature. This view is completely borne out by the subjoined ta- bular arrangement of all the subsulphates of copper I have been able to procure. Could I consent to consider either the water or the oxide of copper as standing in the same re- lation to the other as an acid does to its base, Mr. Graham's theory of the constant neutrality of salts, as applying in this instance, might readily be admitted ; but believing both of them to be only capable of acting as basic oxides, I am compelled to reject it, and admit the existence of basic as I do of acid salts. Mr. Beetz on the Spontaneous Change of Fats. 505 Sulphates of Copper. Anhydrous neutral sulphate. SOa CuO. Green neutral sulphate . S03CuO + HO. (Thomson.) Blue neutral sulphate . S03CuO + 5HO. Trisulphate S03 CuO + 2 CuO 2 HO. 1st tetrasulphate . . . SOa CuO + 3 CuO 3 HO. 2nd tetrasulphate . . . S03 CuO + 3 CuO 3 HO + HO. 3rd tetrasulphate . . . S03 CuO + 3 CuO 3 HO + 2 HO. 1st pentasulphate . . . SOs CuO + 4 CuO 4 HO. 2nd pentasulphate . . . SOs CuO + 4 CuO 4 HO + 2 HO. LXII. On the Spontaneous Change of Fats. By W. Beetz, Esq.* "YVTEi sometimes find in various parts of mines, which have T * not been worked for a considerable time, fragments of a white brittle substance having frequently the appearance of fat, but at times so changed that it presents more the aspect of a mineral body ; I am not aware that any one has examined this substance, and was consequently very much pleased at receiving some pieces of it from different mines. The first specimen was very brittle, so that it could be rubbed to a fine powder ; its appearance was that of tallow. The exterior was a little covered by sesquioxide of iron, but the interior was quite clean. It was found in the " Old Man" iron mine, Xiffau near Runderroth, in the district of Ober- berg. It was dissolved by boiling alcohol without residue, but on cooling was deposited as a flocculent precipitate. Warm aether dissolved it very easily, and from this solution it could be crystallized. When boiled with an alkali, it was converted perfectly, but not very easily, into soap. Submit- ted to destructive distillation the products were the same as those of all fats containing glycerine, as was fully evidenced by the intense and peculiar smell. It melted at 59° C. into a perfectly clear liquid. The analyses of this body showed its composition to be as follows : — I. 0*323 gr. of the substance gave 0*349 gr. of water and 0*904 gr. of carbonic acid. II. 0*314 gr. gave 0*352 gr. of water and 0*878 gr. of car- bonic acid. III. 0316 gr. gave 0*361 gr. of water and 0*878 gr. of car- bonic acid. These results, calculated to the hundred parts, give the following results : — * Communicated by the Chemical Society; having been read April 18, 1843. 506 Mr. Beetz on the Spontaneous Change of Fats. Carbon . I. . 76-32 II. 76-25 III. 75-78 Hydrogen Oxygen . . 12-00 . 11-68 12-45 11-30 1269 1 J -53 100-00 100-00 100 00 This composition is the same as that of stearine from mut- ton tallow, according to the authority of Lecanu. I insert here an analysis of stearine, made by Liebig and Pelouze, and the result of their calculation, in order to compare them with the analysis made by myself. Liebig and Pelouze. Calculated. 146 C =76-14 76-21 236 H= 12*30 12-18 17 O = 11-56 11-61 100-00 100-00 The solubility of the substance is also the same as that of stearine, and the difference of the temperatures at which the two bodies melt is very small. The melting point of stearine is 62°, that of the body under examination 59°, while that of tallow is not more than 37° C. A portion of the body was saponified by soda. The soap was solid and hard, and when dissolved in hot water it formed on cooling a gelatinous mass, even when the quantity of soap was very small. It was decomposed by hydrochloric acid, and the fat acid obtained in this manner was also hard and brittle ; its melting point was 60° C. On burning the acid with oxide of copper, the following result was obtained : — 0*3215 gr. of the substance gave 0*3715 gr. of water and 0-836 gr. of carbonic acid. This composition, calculated to the 100 parts and compared with the analysis and the calculation of stearic acid made by Berzelius, gives the following results: — Calculated. Berzelius. Found. 70 Carbon =79-963 80-145 79-40 134 Hydrogen =12-574 12-478 12-81 5 Oxygen = 7*463 7*377 7*79 It cannot be supposed that this fat came into the mine in the form of stearine, but most probably it had been a miner's candle, and had probably been changed into stearine by the continuous action of water, for the composition of stearine differs from that of tallow in its containing a greater percen- tage of carbon. Tallow contains to 100 parts of carbon, 14*81 hydrogen and 11*76 oxygen. Stearine to the same quantity of carbon, 16*02 hydrogen and 15*14 oxygen; so that this change can be accounted for by supposing that the tallow Mr. Beetz on the Spotitaneous Change of Fats. 507 had combined with water, at the same time that it lost car- bonic acid. The conditions necessary to this process are always found in mines, water is present, and the admittance of air is not required. Another piece of fat was found in the mine Frederic near Tarnowitz ; its appearance was the same as that of the first substance. By boiling alcohol and aether it was not perfectly dissolved. The substance was carefully cleaned outside, and then the exterior portions as well as the interior examined. From the exterior 0*317 gr. were finely scraped and boiled with alcohol, then filtered and washed. The filtered solution was precipitated by water, and weighed 0*057 gr. The residue was boiled with hydrochloric acid ; the weight of the fatty body that was hereby separated was 0*232 gr. The liquid contained nothing but lime in solution, which determined as carbonate weighed 0*044 gr., and is equivalent to 0*025 gr. of caustic lime. The melting point of the fat, soluble in alcohol, was 58° C, that of the fat acid, separated by hydrochloric acid, 60° C. The first fat was from all its reactions stearine, the second stearic acid, so that the substance was composed of 0*257 gr. stearate of lime and 0*057 gr. stearine, or in 100 parts of 17*98 stearine, 7*88 lime, and 73*18 stearic acid. The proportion of lime and stearic acid in the soap is the same as that in the soap prepared in the common manner; for if we calculate the composition of the 81*06 grs. lime-soap, which the substance contains, we obtain the following values : — Found. Calculated. Stearic acid . . 73*18 73*20 Lime . . . 7*88 7*86 Stearine . 17-98 99*04 This composition is confirmed by a second combustion of another portion of the same body. 0'317 gr. of the substance gave 0*833 gr. of carbonic acid and 0*338 gr. of water. If we calculate these numbers to their equivalents in 100 parts, and if the substance consists indeed of stearine and stearate of lime, the resulting values must be the same as those which can be calculated from the known composition of stearine and stearic acid. This is the case in the following table. Stearic acid. Stearine. Calculated. Found. Carbon . 58*54 13*70 72*24 71*66 Hydrogen 9*22 2*19 11*41 11-84 Oxygen . 5*42 209 7*51 8*62 CaO ... 7-88 7*88 73*18 17*96 99*04 100*00 508 On the Spontaneous Change of Fats. 0*986 gr. of the inner portion of the substance was boiled with aether, the solution evaporated and the fatty matter fused, it weighed 0*709 gr. ; the residue, 0*277 gr., was decomposed by hydrochloric acid ; it gave 0*249 gr. of a fat acid and 0*01-7 gr. of carbonate of lime, equivalent to 0*026 gr. of lime. If we calculate these values to the 100 parts and compare them with the numbers derived from the known composition of stearate of lime, and deduct the ascertained amount of the stearate, the remainder will represent the stearine. Found. Calculated. Lime .... 2-640 f 2*70 Stearic acid . . 25*25 J \25*39 Stearine . . . 71*90 71-91 99*79 100*00 In the inner part, consequently, the substance consisted more of stearine and less of soap than on the exterior parts, so that the saponification, which began through the medium of the adjacent lime, is not yet complete, but is more advanced in the exterior portions than the interior. This substance probably had the same origin as the first spe- cimen; it is very similar to [the] adipocire discovered by Four- croy, and which Chevreul has proved to be human fat partly saponified, the bases of which are ammonia, from the nitro- genous compounds of the human body, and magnesia and lime, from the bones. The process of saponification took place in this, as well as in the described substances, by the long-conti- nued action of the materials on each other, which action is not as yet perfected. The change of fats into stearine has many analogies in the manufacture of candles. The manufacturer of stearine candles prefers using tallow of from one to two years old, because it yields a larger profit, and the fat looks a little whiter than fresh tallow. If a piece of mutton tallow is broken asunder and lies in a warm room, the fracture-surface is soon covered with an oily substance, the elaine, which is present in great abundance. The surface of an old fat, treated in the same manner, remains dry and without this oily aspect, because it does not contain so much elaine. The fact that tallow candles become whiter after some time, is not of this nature, because it demands the presence of air, and the can- dles do not become hard, but tough. Another occurrence that gave rise to a product quite re- sembling the described fats must here be mentioned. In a manufactory of candles in Berlin the tallow was poured into a large box; the door of this, by which the fat was taken out, was one day not well closed, some of the fat consequently ran out, and remained under the box during ten years. After this On an Instrument for ascertaining Refractive Indices. 509 time the box was taken away, and the fat was now found quite hard and brittle. I have not been able as yet to obtain any of this substance in order to examine the changes it had under- gone. In a fat of a few years old it would be always difficult to show the change into stearine by an analysis of the elements, for the change could not as yet be very advanced, and the composition of the fat would not therefore be very different from that of stearine. The conditions necessary to the above- mentioned change are the same in the mine as in the cellar where the box stood ; in both water was present, but not a free passage of air. The change in the first two cases had been going on for a long time, for it can be shown that the fat had been in the mines during more than a hundred years. If this one condition could be supplied by another, so that the fat could be changed readily by an artificial process into stearine, it would not be necessary to consider the elaine as a disagree- able addition and to connect it to a bad and cheap product, but the whole substance could be worked as stearine, or from the whole quantity stearic acid could be obtained. The substances described prove the truth of the supposi- tion which Liebig has made in his last treatise " On the pro- duction of Fat," that liquid fats can be changed into hard ones. LXII. On certain Improvements in the Instrument, invented by the late Dr. Wollaston, for ascertaining the Refracting Indices of Bodies. By John Thomas Cooper, Esq.* THE ordinary physical characters of substances such as hardness, colour, lustre, fracture, specific gravity and some others, have been the means which chemists and mineral- ogists have long been in the habit of employing for the iden- tification both of inorganic and organic substances; and I think it will be acknowledged by all who give their attention to such matters, that any additional means added to the above modes of observation, if it be capable of being put into practice with equal facility, and with a certainty of giving results with a degree of precision little, if at all inferior to that which is capable of being attained by the balance, is a sufficient apology for occupying a short time of the Chemical Society. About forty years ago, the late Dr. Wollaston described in the Philosophical Transactions, an ingenious instrument by which the refractive indices of substances, either in a solid or liquid state, could be with facility determined, the method re- * Communicated by the Chemical Society; having been read April 18, 1843. 510 Mr. J. T, Cooper's improvements in Dr. Wollaston's quiring extremely small quantities of the matter to be sub- jected to experiment, was an additional recommendation for its adoption in practice, but it has never been generally brought into use ; and the cause which in my opinion has operated more than any other to prevent its more extended employ- ment in the laboratory of the chemist, is the limited extent of substances which, in the form he gave it to the world, could by its means have their indices of refraction determined with accuracy. It is with the view of rendering the method of Dr. Wollaston more generally known, and of putting the Society into possession of a knowledge of some alteration in the construction of the instrument, by which it is rendered of a more extended application, that I have ventured to call the attention of the Society to this subject. Instead of employing only one species of glass as recom- mended by Dr. Wollaston, I make use of several, each of which is suited to the nature of the substance under examina- tion, and that species of glass is selected for the purpose, which, when the substance to be examined is applied to the base of the prism, gives with the subject so applied, when viewed in its position, neither too acute or too obtuse an incidence ; for it is at extreme incidences, as far as I have been able to ob- serve by the means here employed, that erroneous results are liable to be obtained. The glass prisms which I am in the habit of using have respectively a refractive index for Fraun- hofer's ray b of 1*516, which is ordinary plate glass. 1*583, which is common flint glass. 1*635, a very heavy flint glass, which I made some years ago for optical purposes. 1*816, Faraday's borate of lead glass. Now in order that these different prisms may be used, a modification of the apparatus as originally proposed by Dr. g d e Wollaston is requisite, or otherwise each prism will require a separate and distinct instrument ; but to accomplish this ob- ject with but one instrument, I have changed the position of the indicator from the longer of the bars to the shorter, and constructed the longest bar a in such a manner that it is ca- pable of being extended in length from 15*16 to 18*16 inches, Instrument for ascertaining Refracting Indices, fyc. 511 while the height of the shorter bar b retains the original length proposed by Dr. Wollaston of ten inches, and the indicator c, as a consequence, has only the half of this length, that is to say five inches. The bottom bar d is about two feet in length, and has a dove-tailed groove or furrow ploughed in it through- out its whole length ; in this groove a piece e is made to slide easily, which may be clamped or made fast by means of a thumb-screw in any part that may be required. To this sliding piece is attached a hinge, and to this hinge is also attached one of the sliding bars 1, the other sliding bar 2 being hinged to the bar b. These sliding bars are capable of being fixed at any required length, by means of a clamping-screw. The bar b is hinged to an immoveable blocky of about two inches square, having an excavation of about three quarters of an inch square formed in it, for the purpose of preventing the sub- stances submitted to experiment, on being placed on the base of any one of the prisms, from coming into contact with the wood of which the block is made. Exactly in the middle of the bar b is hinged the indicator c, which is of brass and is filed to a very sharp edge ; it is precisely five inches in length from the centre of the hinge to its extremity. This indicator may be slid along the graduated scale g which is laid down on the upper surface of the bottom bar d, and by means of the pres- sure of the short bar b to which it is attached, will remain in close contact with the graduated scale in whatever position the bars are capable of being placed ; the sharp edge of the indicator is always perpendicular (provided the lengths have been duly attended to, by which is meant the precise distances of the centres of motion of the hinges from each other) to the axis of the hinge which connects the bar b with the moveable bar a. It now only remains to be stated in what manner the instru- ment is to be adjusted, which is to be effected in the follow- ing manner: — When a piece of glass has been selected that is capable of giving with the substance under examination a total reflexion at a mean incidence (by which is meant, when the total reflexion occurs at an angle varying from about 35° to 65°), supposing this to be the case with a prism whose re- fractive power is 1*635, such as would be required to obtain the refractive power of any or most of the fixed oils, then the adjustable bar is to be made sixteen inches and thirty-five hundredths of an inch in length between the centres of the pins of the hinges, and the bottom bar to be shifted until the brass edge of the indicator stands at *635 on the scale ; the substance on being applied to the base of the prism is then to be put into its situation on the block, and the whole ap- 5 1 2 Geological Society. paratus placed in such a way that the light from the sky may fall and be reflected from the base of the prism. The eye being directed along the upper edge of the short or ten-inch bar, the latter is to be elevated or depressed just until the faintest gleam of the substance is to be seen in the bright light reflected from the prism's base, and which, if pro- perly managed, will appear of a very pale blue or bluish- green colour ; when this occurs the indicator will point out the refractive power of the substance under examination. If a very volatile substance, such as any of the aethers or hydro- cyanic acid, should be the subject of experiment, I then am in the habit of employing a small piece of flat glass of a dark co- lour attached by means of the fluid, to be examined, with a very slight pressure to the base of the prism ; this will effec- tually prevent evaporation of the fluid for a period of suffi- cient duration to enable any one with ease and precision to determine the refractive index or power of such a substance ; and in general I prefer using this for all liquids, as it permits a more extended and uniform surface of the matter under examination, and diminishes the liability to error. LXIV. Proceedings of Learned Societies. GEOLOGICAL SOCIETY. [Continued from p. 472.] June 29, 3. " IVf OTICE on the Discovery of Insects in the Weakien 1842. -L^ of the Vale of Aylesbury, Bucks, with some ad- ditional observations on the wider distribution of these and other Fossils in the Vale of Wardour, Wiltshire." By the Rev. P. B. Brodie, F.G.S. In a former notice (Phil. Mag. S. 3. vol. xv. p. 534) Mr. Brodie announced the discovery of insects as well as a new genus of Isopods in the Wealden beds of the Vale of Wardour, and in this communi- cation he gives an account of additional localities in the same Vale, where he has found both the insects and crustaceans, and of the strata belonging to the Wealden series, in which he has obtained fossil in- sects, in the Vale of Aylesbury. Vale of Wardour. — The precise spot noticed in the former paper is a quarry at Dallards, and the first point to which the author now calls attention, is situated about two miles to the south-east of it. The fol- lowing section is given of the beds at the new locality, the dip being slightly to the south : — ft. in. 1. Top. Debris of rounded fragments of greensand and Portland stone, with their usual fossils, a few inches thick. 2. Chert, full of Cyclas ; it also contains occasionally Bufonites J 6 The Rev. P. B. Brodie on Insects in the Wealden. 513 ft. in. 3. Hard, brownish white limestone, with Ostreae and casts of other shells, some resembling those of Cy- clas major. The upper layers much disturbed .... 2 0 4. Black earthy clay, a few inches. 5. Purbeck stone, varying in character but containing Cyclades 5 0 C. Fissile, soft stone full of Modiolse, palates and other remains of fishes, also bones of a species of tortoise 1 0 7. White limestone, containing Isopods and elytra of Coleoptera 3 0 Hardstone. In an escarpment in the banks of the adjoining river are two beds of limestone, from the upper of which Mr. Brodie obtained small ely- tra, and from the lower Cypris, and from both carbonized wood, also a species of Cyclas. Under these strata is a very oolitic limestone, in which the author found a small Melanopsis and a seed-vessel. A mile distant Mr. Brodie procured from a bed of limestone, about five inches thick, Cyclades, Isopods, and a small fish of the species which occurs at Dallards ; and in a bed of clay, bones of a tortoise. The hard crystalline limestone of the Lady-down beds are noticed as yielding, but rarely, Cyclades and Cyprides. In the neighbourhood of Tisbury, in a soft, gritty, slightly oolitic stone, the author found Isopods of a larger size than elsewhere, likewise an elytron of a cole- opterous insect. Though the number of beds of limestone vary in different parts of the Vale of Wardour, yet Isopods and insects cha- racterise the whole of them ; and as respects lithological characters, notwithstanding the great varieties which occur at different localities, there is throughout the district that general peculiarity of aspect which is so remarkable in freshwater formations of very different ages, and which serves to identify detached quarries with each other. Vale of Aylesbury. — In Buckinghamshire the Wealden beds possess a certain similarity with those in Wiltshire, but with clearly marked local differences. At Quainton Hill Mr. Brodie could not discover any traces of fishes, insects, or Isopods. In a quarry near the village of Stone he obtained the following section : — 1 . Rubble, several feet. 2. Hard white stone, no fossils 2 to 3 feet. 3. Greenish stone, with Cypris 2 feet. 4. Black clay, containing bones of a Tortoise .... 1 foot. 5. White and blue limestone (Pendle), yielding Modiolse in abun- dance j also a few Cypris and Cyclas ; likewise bones and palates of fishes, coprolites, and, but rarely, remains of insects ; fragments of carbonized wood are common ; and Mr. Brodie obtained a speci- men of Sphenopteris Mantelli, and another minute but beautiful species of Fern. This limestone bears a close resemblance to one of the beds at Dallards. In his general observations on the fossils from these different local- ities, the author states, that though he has greatly added to the num- ber and variety of insect-remains since his former communication, yet Phil. Mag. S. 3. No. 155. Suppl. Vol. 23. 2 L 514? Geological Society: Mr. Lyell on the Fossil he has not found any of the larger kinds, almost every specimen re- quiring a high magnifying power to be seen distinctly. Next to the Coleoptera, the most prevalent orders are the Homoptera and Tri- chopteraj and Mr. Brodie observes, that this fact accords with the habits of the two latter orders, the first living on plants, remains of which are found abundantly in the Wealden, and the second hovering over the surface of streams. From the fragmentary state of these remains, and from the wings never being expanded in the more nearly perfect specimens, he considers it probable, that they were carried for some distance down the streams which flowed into the Wealden estuaries. A few of the insects which have been exa- mined by an eminent entomologist, have been pronounced to possess, with one exception, a decidedly European character, to differ from those at Aix, and to be less tropical than those found at Stonesfield. Since the reading of his prior communication, Mr. Brodie has ob- tained Isopods an inch and a half in length and an inch broad. These crustaceans, so interesting from the analogy to Trilobites, presented by allied genera, are rarely found in single specimens, but in groups, and therefore present this additional agreement with the habits of re- cent species. The fossils appear to have been deposited tranquilly at the bottom of the water which they inhabited, being always found imbedded with their legs downwards, and they are generally well-pre- served. The whole of the freshwater remains of these Wealden beds, including the testacea, afford the natural characters of such deposits bv yielding abundance of specimens, but few genera. Associated with the above-mentioned organic remains of the Vale of Wardour, Mr. Brodie has obtained three species of small fishes quite distinct, he says, from those found at Lady Down and Chicks- grove. With a single exception they were all procured at one spot. None of the localities mentioned in the paper afforded the least trace of the " dirt-bed," or of Cycadeoidea. 4. " On the Geology of Egypt." By Lieut. Newbold of the Ma- dras Army, F.R.S. [An abstract of this paper will be found in our preceding volume, p. 215.] 5. A letter, addressed to the Secretaries by C. Kaye, Esq., " On a Collection of Fossils discovered by the writer in Rocks in Southern India." The localities from which Mr. Kaye procured his suites of speci- mens are Pondicherry, Trichinopoly, and Verdachellum. Pondicherry. — From a limestone in the neighbourhood of this city, Mr. Kaye obtained Nautili in great abundance, belonging to at least three species ; Ammonites in even greater numbers and well-pre- served, and although assignable to thirteen distinct species, the au- thor has not been able to identify a single specimen with any Euro- pean Ammonites of which he has seen a description. Baculites like- wise occur in such quantities as often to constitute the entire mass of large blocks ; and Hamites in a great variety of forms, besides numerous genera of conchifera and mollusca ; likewise Echinidse, Polyparia, fishes' teeth, and considerable masses of calcareous wood bored by Teredines. Foot-prints of Birds, SfC in the Valley oftlie Connecticut. 515 All these fossils were discovered by Mr. Kaye and a friend within the last two years, and are entirely new to European palaeontologists. In the neighbourhood of Pondicherry and bordering on the lime- stone is a bed of red sand containing an immense quantity of the sili- cified wood long known to collectors. Trkhinopoly. — The spot in this district from which Mr. Kaye pro- cured his specimens he was not able to visit. The fossils occur also in a limestone, preserve their shelly matter with occasionally the colour, and belong principally to marine genera, but some are con- sidered to be of freshwater origin. Cephalopods appear to be of very rare occurrence, Mr. Kaye having obtained from the locality only one fragment of a large Ammonite. Wood bored by Teredines is also found in the limestone. Verdachellum. — From a calcareous rock near Verdachellum, forty miles from Pondicherry, Mr. Kaye procured a variety of marine shells, including a considerable number of Ammonites, considered by him to be distinct from those found near Pondicherry ; also a few imperfect Nautili and a few Echinidse, corals, &c. Among the testacea are several considered to belong to species found in the Trichinopoly deposit, and a few believed by Mr. Kaye to be identifiable with Pondicherry shells. This limestone is likewise bordered by a red sand which contains specimens of silicified wood. The formation was discovered only a short time before the writer quitted India, and he consequently considers his collection as defec- tive ; but he regards the deposit whence it was obtained as of interest, affording, by its position and organic contents, a link between the other two localities. 6. A paper " On the Fossil Foot-prints of Birds and Impressions of Rain-drops in the Valley of the Connecticut." By Charles Lyell, Esq., V.P.G.S. The deposit in which these impressions, long known on account of the researches of Prof. Hitchcock, occur, is situated in a trough of hypogene rocks, about five miles broad, the strata, which consist of sandstone, shale and conglomerate, dipping uniformly to the east at angles that vary from 5° to 30°. Mr. Lyell first examined the red sandstone at Rocky Hill, three miles south of Hartford, in Connec- ticut, where it is associated with red shale and capped by twenty feet of greenstone. Many of the beds are rippled, and cracks in the shale are filled by the materials of the superincumbent sandy layer, showing, the author observes, a drying and shrinking of the mud while the accumulation of the strata was in progress. The next quarries he examined were at Newark in New Jersey, about ten miles west from New York city. The excavations are extensive, and the strata dip, as is usual in New Jersey, to the north-west, or in an opposite direction to the inclination in the valley of Con- necticut, a ridge of hypogene rocks intervening. The angle is about 35° near Newark. The beds exhibited ripple- marks and casts of cracks, also impressions of rain-drops on the upper surface of the fine red shales. Mr. Lyell states, that he felt some hesitation respecting the impressions first assigned to the action of rain by Mr. Cunning- 2 L2 516 Geological Society: Mr. Lyell on the Fossil ham of Liverpool*, but he is now convinced of the justness of the inference, having observed similar markings produced on very soft mud by rain at Brooklyn in Long Island (New York). On the same mud were the foot-prints of fowls, some of which had been made before the rain and some after it. Mr. Lyell next visited the red and green shales of Cabotville, north of Springfield in Massachusetts, where some of the best Ornithich- nites have been procured, chiefly in the green shale. The clip of the beds is 20° to the east, a higher inclination, the author says, than could have belonged to a sea-beach. He observed in the same quar- ries ripple-marks as well as casts of cracks, and he was informed that the impressions of rain. drops have likewise been found. In company with Prof. Hitchcock, Mr. Lyell afterwards examined a natural section near Smith's Ferry, on the right bank of the Con- necticut, about eleven miles north of Springfield. The rock con- sists of thin-bedded sandstone with red-coloured shale. Some of the flags are distinctly ripple-marked, and the dip of the layers on which the Ornithichnites are imprinted, in great abundance, varies from eleven to fifteen degrees. Many superimposed beds must have been successively trodden upon, as different sets of tracks are traced through a thickness of sandstone exceeding ten feet ; and Prof. Hitchcock pointed out to the author that some of the beds exposed several yards farther down the river, and containing Ornithichnites, would, if prolonged, pass under those of the principal locality, and make the entire thickness throughout which the impressions prevail, at intervals, perhaps twenty or thirty feet. Mr. Lyell, therefore, con- ceives that a continued subsidence of the ground took place during the deposition of the layers on which the birds walked. It has been suggested, but the opinion has not been adopted by Prof. Hitchcock, that the eastward slope of the beds represents that of the original beach. With a view to this question, Mr. Lyell exa- mined the direction of the ripple-marks, and found that it agreed with the dip, or was at right angles to the supposed line of beach ; but he adds, though this agreement presents a formidable objection to the suggestion above alluded to, if the ripples were produced by waves, yet it does not disprove the opinion, as the ripples do not exceed in dimensions those which are produced by sand blown over a muddy beach, and often distributed at right angles to the coast-line. In- stances of this effect of the wind Mr. Lyell has remarked along the shores of Massachusetts. Nevertheless he is of opinion that the rippled layer of sandstone in question contains too much clay to have resulted from blown sand, and he is disposed to think that in most of these localities the strata have been tilted, instances of such dis- turbance having been pointed out to him by Prof. Hitchcock in the state of Massachusetts, and by Mr. Percival near Newhaven in Con- necticut. In reference to this subject, he says, that a few miles from Smith's Ferry a conglomerate, several hundred feet thick, containing angular and rounded fragments of trap and red sandstone, the base being sometimes a vesicular trap and trap tuff, passes upwards into * See Phil. Mag. S. 3. vol. xiv. p. 507. Foot-prints of Birds, fyc, in the Valley of the Connecticut. 517 the very flags on which Ornithichnites occur; and from this he infers, that there were eruptions of trap, accompanied by upheaval and par- tial denudation, during the deposition of the red sandstone. With respect to the impressions having been made by birds, Mr. Lyell states, that until he examined the whole of the evidence he entertained some scepticism, notwithstanding the luminous account given by Prof. Hitchcock. In proof of their being the foot-prints of some creature walking on mud or sand, he mentions, 1st, the fact of Prof. Hitchcock's having seen 2000 impressions, all, like those he had himself examined, indented in the upper surface of the layer, the casts in relief being always on the lower surface ; and 2ndly, that where there is a single line of impressions the marks are uniform in size, and nearly uniform in distance from each other, the toes in the successive steps turning alternately right and left. Such single lines, Mr. Lyell says, indicate that the animal was a biped, and the trifid marks resemble those which a bird leaves, there being generally a deviation from a straight line in any three successive prints ; and his attention having been called to indications of joints in the different toes, he afterwards clearly recognised similar markings in the recent steps of coots and other birds on the sands of the shores of Massa- chusetts. Prof. Hitchcock has shown, that the same impression ex- tends through several laminae, decreasing in distinctness in propor- tion as the layer recedes from that in which it is most strongly marked, or in proportion as the sediment filled up the hollows and restored the surface to a level ; and Mr. Lyell states, that he has observed a great number of instances of this fact. He also says, that he can scarcely doubt that some of the impres- sions on the red sandstone of Connecticut are not referable to birds, but he believes that the gigantic ones described by Prof. Hitchcock are Ornithichnites. At Smith's Ferry they are so numerous that a bed of shale many yards square is trodden into a most irregular and jagged surface, so that there is not a trace of a distinct footstep ; but on withdrawing from this area to spots where the same tracts are fewer, the observer, Mr. Lyell says, is forced to admit that the effect in each case has been produced by this cause. On examining the shores on some small islands about fifteen miles south-east from Savannah, the author was struck with the number as well as the clearness of the tracks of raccoons and opossums imprinted in the mud during the four preceding hours, or after the tide had be- gun to ebb. At one spot, where the raccoons had been attracted by the oysters, the impressions were as confused as when a flock of sheep has passed over a muddy road ; and in consequence of a gentle breeze blowing parallel to the line of cliffs composed of quartzose sand, the tracks had in many places already become half-filled with blown sand, and in others were entirely obliterated ; so that if the coast should subside, the consolidation of this sand would afford casts analogous to those of Storeton Hill in Cheshire, yet the im- pressions had been made and filled in a few hours. When considering the broad question whether the fossil foot-prints were made by creatures walking on mud or sand after the ebbing of 518 Geological Society. the tide, Mr. Lyell reminds his readers of the fact that in the United States, as in Saxony and Cheshire, the tracks in sandstone and shale are accompanied by littoral appearances, as ripple-marks, the casts of cracks in the clay, and often by the marks of rain. In regard to the age of the red sandstone of the valley of the Connecticut and New Jersey, the author states he has nothing to add to what had been previously advanced, by which its position had been shown to be between the carboniferous and cretaceous series. In the neighbourhood of Durham, Connecticut, he had col- lected in the sandstone, fishes of the genera Palreoniscus and Cato- pterus, but no other organic remains, except fossil wood. In conclusion, Mr. Lyell remarks, 1st, that the Ornithichnites of Connecticut should teach extreme caution in inferring the non- existence of land animals from the absence of their remains in con- temporaneous marine strata ; 2ndly, that when this red sandstone of Connecticut was deposited, there was land in the immediate vici- nity of the places where the Ornithichnites occur ; and that but for them it might naturally be inferred that the nearest land was several miles distant, namely, that of the hypogene rocks which bound the basin of the Connecticut. Now, the land that caused the sea-beach, Mr. Lyell says, must have been formed of the same sandstone which was then in the act of accumulating, in the same manner as where deltas are advancing upon the sea. In a postscript, Mr. Lyell states, that subsequently to writing the paper he had read the luminous report of Mr. Vanuxem on the Or- nithichnites described by Prof. Hitchcock, and though it agrees in substance with his own account in some particulars, yet that he has left his notice as it stood. 7. The following notice by Captain Pringle respecting the Ochil Hills : — A gentleman resident in the district had often remarked the oc- currence of sounds, which appeared to him to be subterranean, but which the country people attributed to noises from the river Divan, or to the machinery of iron-works some miles distant. At the time of the earthquake, however, which was felt at Comrie in October 1840, he was on the hill and heard a loud noise like the rushing of steam through a cavern, and the same noise was heard also by others two to three miles distant. On inquiry he ascertained that the noise was contemporaneous with the earthquake, and that the machinery at the iron-works was at that moment not in action. The Gaelic word ochain or ochail signifies moaning, howling, wailing (Armstrong's Dictionary) ; and hence it is inferred that the name of the " Moaning Hills " may have been given to the range from the sounds so frequently heard in the district ; and further, that the sounds are connected with the earthquakes felt in the neighbourhood, near Crief and Comrie. [On these Earthquakes see Phil. Mag. S. 3. vol. xx. p. 240.] November 2, 1842. — On the Geology of the Western States of North America. By David Dale Owen, M.D., of Indiana*. * Abstracts of this and of other papers on the Geology and Palaeonto- Lieut. R. B. Smith on the Delta of the Ganges. 519 Nov. 16, 1842. — A paper was read " On the Structure of the Delta of the Ganges, exhibited by the Boring Operations in Fort William, a.d. 1836-40." By Lieut. R. Baird Smith, B.E. Since the year 1804, a number of boring operations have been conducted in the Gangetic Delta, with a view to supply the deficiency of good fresh water in the vicinity of Calcutta, but, from mechanical obstacles, without success. The geological results of the last of these experiments, commenced in April 1836, and abandoned in 1840, after being carried on to the depth of 480 feet, are detailed by Lieut. Smith in this memoir. After penetrating to the depth of ten feet through the artificial surface soil, a bed of blue clay, close and ad- hesive in its texture, was entered. As the bore descended, the clay became darker in colour, till, in from thirty to fifty feet, large por- tions of peat, with decaying fragments of trees, were found. These Dr. Wallich identified with the common Soondri of the Sunderbunds, and the roots of some climbing tree resembling Brcedelia. The stra- tum of peat and decayed wood was therefore formed from the debris of forests which at a former period covered the entire surface of the Delta, as the existing jungles of the Sunderbunds cover so large a portion of it now. In one instance bones were found in the peat, but they were unfortunately destroyed by the workmen before exa- mination. Succeeding these peat-charged beds, a stratum of calca- reous clay, ten feet in thickness, is found, and intermixed with it are portions of the concretionary limestone, commonly known in India as kankur, which Lieut. Smith regards as formed by the se- gregation of the particles of calcareous matter disseminated through- out the body of the clay with which it is associated, and as nearly contemporaneous in -its origin with this clay. Underlying the bed of calcareous clay in which the kankur first occurs, there is a thin bedjof green siliceous clay, extending from sixty to sixty-five feet in depth. The clay then loses its colour, and continues to a depth of seventy-five feet, the lower portion of it furnishing nodules of kankur. At seventy-five feet, a bed of variegated, sandy, or arenaceous clay commences, and continues to the depth of 120 feet, occasionally traversed by horizontal beds of kankur. Beneath this is a stratum of argillaceous marl, five feet in thickness ; and succeeding it there is a bed only three feet in thickness, of loose friable sandstone, the par- ticles of sand being held loosely together by a clayey cement. Ar- gillaceous marl, twenty feet in thickness, follows the sandstone, ter- minating at the depth of 150 feet, when it passes into an arenaceous clay, intermixed with water-worn nodules of hydrated oxide of iron. Weathered mica slate is found attached to the clay of this bed, and throughout the entire range of strata penetrated, scales of mica have always been abundantly met with. At 175 feet, a coarse friable quartzose conglomerate occurs, composed of pebbles of different sizes, though none are very large, cemented together by clay. At 177 feet, this conglomerate becomes smaller grained ; and at 1 83 feet 3 logy of North America, by Dr. Dale Owen, Mr. Lyell, Dr. Mantell, Mr. Redfield and Mr. Cooper, read before the Geological Society from Nov. 2, 1842, to Feb. 1, 1843, have been given in the present volume, p. 180. 520 Geological Society. inches, it is found to pass into indurated ferruginous clay, which continues, with but little variation, to a depth of 208 feet. Here another layer of sandstone, soft in its upper portion, but becoming more indurated, and assuming the lamellar structure as it is passed through, occurs ; the thickness being, however, no more than three feet. Ferruginous sand, with thin beds of calcareous and arenaceous clay, prevail from 208 feet to 380. Kankur, with minute water- worn fragments of quartz, felspar, granite, and other indications of debris from primary rocks, are met with in the lower parts of this sandy de- posit, in which were also found three fragments of bones, of which one was considered by Mr. J. Prinsep to be the lower half of a humerus of some small quadruped like a dog, and another the fragment of the carapace of a turtle. At 380 feet, there occurred a thin layer, only two feet in thickness, of blue calcareous clay, thickly studded with fragments of shells; and at 382 feet, this was succeeded by a layer of dark clay, composed almost entirely of decayed wood. From the lower portion of it several fragments of coal, of excellent quality, were brought up. Underneath this stratum, and in the gravelly bed which immediately succeeds it, there were found several other fragments of fossil bones. One was considered to be a caudal ver- tebra of a kind of lizard, and the rest were fragments of turtles. These were discovered at the depth of 423 feet, and were associated with large rolled pebbles of quartz, both white and amethystine, felspar, limestone, and indurated clay. The gravel, composed en- tirely of the debris of primary rocks, continued to the depth of 481 feet, where the operations ceased. The fossils recorded above, observes the author, were found in two distinct deposits, separated from each other by the interposition of a bed of shelly, calcareous clay and a deposit of carbonaceous matter ten feet in thickness, the remnants of some extensive forest which flourished at a period anterior to the deposit of the 380 feet of su- perincumbent sands and clays. The lithological characters of the superior and inferior fossiliferous deposits differ considerably from each other, the former being a fine and slightly indurated sandstone, the latter a coarse conglomerate, formed of the debris of primary rocks, imbedded in an arenaceous matrix. The fossils of the upper bed, which is about eighty feet in thickness, furnish the only speci- mens of mammalia obtained during the operations. These were as- sociated with the remains of Chelonians, but no indications of the existence of saurian animals were discovered till the shelly clay and carbonaceous bed were passed through, and from the lower conglo- merate no mammalia were obtained. In drawing any conclusions, however, the limited space examined, the diameter of which wasjtot more than six inches, must be borne in mind. Lieut. Smith remarks the correspondence of the succession of the strata in the Gangetic Delta, at a depth of from 350 to 480 feet, with that observed by Captain Cautley at the base of the Himalaya. The nature of the fossil remains and the dimensions of the gravel found at 480 feet from the surface of the ground, the greatest depth hitherto attained, were such as to lead Dr. M'Clelland to the con- Mr. Trimmer on Pipes or Sandgalls in Chalk. 521 elusion, that when these were originally deposited hold rocky moun- tains existed in close proximity to the present site of Calcutta ; and taking his data from the results of personal observation on the trans- porting power of rapid currents, he estimates the distance of these mountains at not greater than twenty or thirty miles. Resting on the bed of coarse conglomerate, the entire depth of which is un- known, although it cannot be less than eighty feet, the bore having pierced it to that extent, there are beds of carbonaceous matter and lacustrine clay bearing the clearest evidence of having been quietly deposited on a marshy surface clothed with vegetation. Ere this could have taken place, the powerful currents indicated by the gravel must have been arrested, and as this could only be effected by a great lowering of the inclination of the bed of the river, we may infer the check arose from the entire subsidence of the range of hills above alluded to. The extent to which this took place it is impossible for us to estimate, but the deposits which the river continued to make would repose upon the depressed masses, and were boring operations to be carried on successfully in such localities they would ultimately expose these again to our observation. Supposing then, as without impropriety we may do, that the rocks of which these hills were composed stretched away beneath the conglomerate bed formed by the large gravel borne along by the torrent issuing from them, we are led to believe that had the Fort William boring operations been successfully carried through the entire depth of the conglomerate, the auger would then have impinged on the solid rock, and if so, would the experiment have terminated favourably ? " When we remember," observes Lieut. Smith, " that the con- glomerate was almost entirely composed of debris from primary rocks, admitting of the inference that the chain of hills itself was formed of members of this series, there can be but little hesitation in replying in the negative." " On Pipes or Sandgalls in Chalk." By Joshua Trimmer, Esq., F.G.S. In a former paper (Proceedings, vol. iii. p. 185) the author de- scribed two detrital deposits in Norfolk, which appear to have been produced by powerful currents of water. The lowest of these is marked on the surface with numerous furrows and penetrated by cylindrical and funnel-shaped cavities like those of the chalk, though in general of smaller dimensions. If these have been caused by the mechanical action of water, they indicate a pause between the two deposits of sufficient duration to allow of the consolidation of the lower bed before the other was thrown down upon it. Therefore, to learn the true history of the beds, we must discover the cause of the pipes ; the action is so similar in the chalk and the detrital de- posits that the one will explain the other. From recent study of the pipes or sandgalls in the chalk of a part of Kent, Mr. Trimmer has arrived at the conclusion that they are due to the mechanical, not to the chemical action of water ; and that this action was the breaking of the sea on a low shore antecedent to the formation of the eocene strata. This opinion he bases on the following grounds. 522 Geological Society : Mr. Strickland Having had an opportunity of observing the removal of its cover- ing from the chalk near Faversham, Mr. Trimmer found that the pipes were but the terminations of furrows from six to twenty-four inches deep in the shallowest parts exposed, but widening and deep- ening as they approached the pipes till they were lost in them. The diluvial covering spread over the chalk is a strong loam of a reddish brown colour, with numerous unabraded flints dispersed through it. The pipes were filled with loam of a more sandy nature and of a much lighter colour. The few pebbles found in them con- sisted of chalk flints much water- worn, and contrasting strongly with the unabraded flints of the diluvium. Their sides were lined with clay, tinged black. The lower part of the diluvial deposit, near its junction with the chalk, had in many places the same black tints. None of the pipes terminated downwards in a point, the apices of the inverted cones being three or four inches broad. These facts the author considers indicative of the mechanical action of water. He observed certain blocks of siliceous sandstone, derived from the sands of the London clay, marked with similar pipes and furrows, though of smaller dimensions, which could not have been formed by the action of acidulated water. In these the pipes occasionally com- menced from the opposite sides of the same block, perforating it, therefore not formed by rain. On the sea-shore near Reculver he saw similar blocks, presenting pipes in miniature. The waves charged with small pebbles and sand, wearing the surface with furrows like those of the chalk, the softer parts of the stone then giving way, first hollows are formed, then the rotatory motion of the contents of the hollows, set in action by the influx and reflux of the waves, drills the pipe. The pipes and furrows in the sandstone blocks Mr. Trimmer con- siders as having been produced by the same agency, and their perfo- ration, as caused in consequence of their reversion by a violent storm and the drilling operation then going on at the opposite side. The examination of a chalk bed near Canterbury convinced Mr. Trimmer that the same causes had produced the pipes and furrows in the chalk. He remarks, that the sand with which the pipes were filled contains much calcareous matter, and that it appears impossible that acidulated water, percolating from above, could have acted on the chalk without first removing all carbonate of lime from the sand. In all cases observed by Mr. Trimmer the sandgalls were confined to the edges of channels which are either now traversed by tidal currents like the trough of the Thames, or appear, like the dry combes, to have communicated with the sea at some remote period. From the above facts, Mr. Trimmer infers that the pipes in the chalk of the part of Kent examined were formed by the action of the sea on a low shore ; that they mark the boundaries of the ante- eocene sea, and that they were subsequently submerged and covered by the London clay. " On some remarkable Concretions in the Tertiary beds of the Isle of Man." By H. E. Strickland, M.A., F.G.S. The north extremity of the Isle of Man consists of an arenaceous pleistocene deposit, occupying an area of about eight miles by six, on Concretions in the Tertiary Beds of the Isle of Man. 523 bounded on the west, north and east by the sea, and on the south by the mountains of Cambrian slate which occupy the greater por- tion of the island. The arenaceous formation attains in some parts a height of about 200 feet above the sea, though the undulations of its surface prove that considerable portions of the deposit have been removed by denudation. This district, comprising about fifty square miles, furnishes perhaps the most extensive example in the British Isles of a marine newer pliocene or pleistocene deposit. In the Isle of Man the sea- cliffs on each side of this tertiary district afford a good insight into its structure and composition. On the north of Ramsey the cliffs average about 100 feet in height, and consist prin- cipally of irregularly stratified yellowish sand, sometimes clayey, with interspersed bands of gravel and scattered pebbles. The gravel is chiefly composed of slate-rock, quartz, old red sandstone, granites, porphyries and chalk flints, all of which occur in situ in the island except the last two, which may have been drifted, the former from Scotland, and the latter from the north of Ireland. About four miles north of Ramsey the cliffs attain 150 feet. Here the lowest portion, only visible at intervals, is a brownish clay loam, and the remainder of the cliff is sand and coarse gravel, less distinctly stratified than is the case near Ramsey, and containing rudely rounded boulders, some of which are upwards of a ton in weight. They consist of granite, and occasionally of carboniferous limestone. Organic remains are sparingly diffused in this deposit : Mr. Strick- land enumerates twenty species. Of these five, viz. Crassina mul- ticostata, Natica clausa, Nassa monensis, Nassa pliocena, and Fusus Forbesi are not known in the British seas. Crassina multicostata and Natica clausa are found living in the Arctic ocean, but the two species of Nassa and the Fusus are unknown in a recent state*. * Mr. Strickland gives the following characters of three species of shells found in the newer pliocene beds of the Isle of Man ; specimens of which have been examined by several eminent conchologists in London, who all concur in believing them to belong to extinct species. " 1. Nassa monensis, Forbes, in Mem. Wern. Soc, vol. viii. p. 62. Small; volutions about six, rounded; suture deep ; ribs, nine on the first volution, straight, rather distant, strong, subacute, and slightly oblique. The first volution has thirteen, and the second six, distinct, regular, thread-like, spiral striae, crossing alike the ribs and their interstices. Aperture orbicular-ovate, canal very short and oblique, pillar-lip simple, outer lip with about five slight marginal denticles on the inside, and an external rib slightly more developed than the ordinary ribs. Total length, 7 lines ; first volution, 3i, lines ; breadth, 4^ lines ; angle of spire, 40°. " Obs. Resembles the recent N. macula, but is larger, more ventricose, has fewer ribs, and the terminal rib is less suddenly developed. "2. Nassa pliocena, Strickland, 1843. Large; volutions about seven, rath;r flat, with a distinct thread-like suture ; ribs, twelve on the first volu- tion, straight, distant, rounded, very slightly oblique; the interstices flat, exceeding the width of the ribs by one-half. The first volution with thir- teen, and the second with about nine fine spiral striae, only visible in the in- terstices, the ribs being smooth ; but this may be due to attrition. Aperture ovate ; canal very short and oblique ; pillar-lip with about five obscure den- ticles, and a spiral groove immediately behind the canal, continued into the 524 Geological Society. Between three and four miles north of Ramsey, the beds of this deposit occasionally exhibit a very remarkable concretionary struc- ture. The sand has here been cemented into masses, which are ex- tremely hard, and even sonorous when struck, though the sand in which they are imbedded is perfectly loose. The cementing ingre- dient, which the application of acid proves to be carbonate of lime, seems to have been influenced in its operations partly by the planes of stratification, and partly by the direction in which the sand has been originally drifted by currents. In the former case the concre- tions are in the form of flat tabular masses parallel to the stratifica- tion, often mammillated on their surfaces, or perforated obliquely by tubular cavities. In the latter case they assume a subcylindrical or spear-shaped form, and occur parallel both to the stratification and to each other. A pebble is frequently attached to the larger end of the concretion, which springs from it as from a root, to the length of a foot or more, and gradually terminates in an obtuse flat- tened point. All these varieties are sometimes combined together into vast clusters of several tons weight, resembling masses of sta- lactite, the component portions being nearly parallel to each other. Mr. Strickland supposes that currents of water (or possibly of wind, operating during ebb tide), flowing in a certain direction, may have disposed the sand in ridges parallel to that direction, and the car- bonate of lime may have afterwards been attracted into these ridges in preference to the intermediate portions. This view is confirmed by the fact, that these concretions have frequently a pebble attached to the larger end, as though it had protected a portion of sand from the current, and caused it to accumulate in a ridge on the lee side, a circumstance which may frequently be observed where sand is drifted by the wind or water. Nov. 30, 1842. — " On the Bala Limestone." By Daniel Sharpe, F.G.S. interior of the shell. Outer lip with about eight internal marginal denticles ; no rib at the back. Total length, 1 inch 8 lines ; first volution, 8 lines ; breadth, 9 lines ; angle of spire, 40°. "3. Fusus Forbesi, Strickland, 1843. Fusus nov. sp. Forbes, Malacologia Monensis, pi. 3. f. 1. Middle-sized; volutions about six, slightly rounded, suture distinct; ribs, eleven on first volution, straight, rounded, smooth (perhaps from attrition) ; interstices concave, and hardly wider than the ribs. First volution with about fifteen, and second with about seven distinct, rather irregular spiral stria?, of which those on the first volution are alter- nately large and small. They are only visible in the interstices of the ribs. Aperture ovate, double the length of the canal, which is straight, and rather oblique to the left. Pillar-lip smooth, with one obscure denticle at the pos- terior end. Outer lip with about ten small linear denticles within, conti- nued a short way into the mouth, and a well-marked external rib remote from the margin. Total length, 1 inch 3 lines ; first volution, 7 lines ; breadth, 8 lines ; angle of spire, 43°. " Obs. This species belongs to a group of Fusus which seems closely allied to Nussa. First described by Mr. E. Forbes, from a worn specimen found on the coast of the Isle of Man, and supposed by him to be an existing spe- cies, but the discovery of additional specimens in situ proves it to be a genuine fossil." Mr. D. Sharpe on the Bala Limestone. 525 Before entering upon his own views, the author quotes the opinions published by others upon the age of the limestones of Bala and Coni- ston ; previous to the labours of Professor Sedgwick and Mr. Mur- chison, these two calcareous bands were thought to be of the same age, and to be nearly the oldest fossiliferous beds in this country ; but the first definite arrangement of them was made by Professor Sedgwick, whose views will be found in our Proceedings (vol. ii. p. 675), placing both these limestones in the Upper Cambrian system, which he stated to lie below the Silurian system of Mr. Murchison, and above the Lower Cambrian system, or old slate series of Car- narvonshire, Cumberland, &c, a view adopted by Mr. Murchison in his work upon the Silurian system, upon the authority of Professor Sedgwick. In 1839 Mr. James Marshall classed the Coniston limestone with the Caradoc sandstone, upon the evidence of fossils examined by Mr. J. Sowerby, and pointed out that it rested upon the Lower Cambrian rocks ; thus omitting the Upper Cambrian system in the North of England (Reports of the British Association, vol. viii. p. 67.). The second edition of Mr. Greenough's Map adopts Mr. Marshall's view of the age of the Coniston limestone, and omits the Upper Cambrians in the district of the Lakes ; but retains them in North Wales, under the name of Upper division of the lower Killas, in which is included the Bala limestone, thus placed in a different system from the limestone of Coniston. Professor Sedgwick's memoir of November 1841 follows the same view (Proceedings, vol. iii. p. 545) ; and in a note, p. 551, that author removes all doubt as to his opinions by apologizing for having for- merly placed the Bala and Coniston limestones on the same parallel. Notwithstanding the agreement of our best geologists in placing the Bala limestone in the Upper Cambrian system, Mr. Sharpe was induced to doubt the accuracy of this classification, by observing that everyone admitted that the Bala fossils agreed, as far as they had been examined, with those of the Lower Silurian beds, and that there was no clear line of separation between the Lower Silurian and Up- per Cambrian groups : but his attention was particularly drawn to this district by Mr. Bowman's observations on Denbighshire, laid before the British Association in 1840 and 1841, and since published in the first volume of the Transactions of the Geological Society of Manchester, p. 194, which Mr. Sharpe regards as the first indication of the true structure of this part of North Wales ; Mr. Bowman classes as Upper and Lower Silurian many beds before mapped as Upper Cambrian, showing that the previous classification of the rocks of North Wales could not be relied upon. Mr. Sharpe quotes largely from Mr. Murchison's Address from the Chair in February 1842, to show that the Upper Cambrian can- not be separated from the Lower Silurian beds by the help of organic remains, as " Lower Silurian species range through the Upper Cam- brian rocks, and throughout the whole of North Wales," and " pre- vailed during that vast succession of time which was occupied in the accumulation of all the older slaty rocks previous to the Upper Silu- rian period." 526 Geological Society. Mr. Sharpe points out, that up to the moment of his taking up the subject no one of the authors quoted had expressed a doubt of the existence of a great thickness of fossiliferous beds below the Caradoc sandstone and Llandeilo flags, although it was admitted that these supposed beds could not be distinguished by their fossils from the Lower Silurian ; and he states that the object of his communication is to show the error of this view as relates to the Bala rocks, which he proposes to prove to be the equivalent of the Lower Silurian beds described by Mr. Murchison, and not part of an older series ; and he infers from analogy that the same will be found to be the case in other parts of North Wales which he has not visited, where he conjectures that all the rocks containing shells of Lower Silurian species will also prove equivalents of the Lower Silurian beds. In- stead of continuing the Silurian system downwards through a vast thickness of slate rocks, Mr. Sharpe proposes to strike out one of its original members, regarding the Caradoc sandstone and Llandeilo flags as one and the same formation which has received different names according to its mineral character ; he observes, in confirma- tion of this view, that both formations are never equally developed in the same district, and that the fossils found throughout are too nearly the same to warrant the separation of the lower beds under a separate name. Still Mr. Sharpe believes that there are in Wales, as in Westmoreland and Cumberland, vast accumulations of slatv rocks below the Silurian system, in which no fossils have been found, and which must retain the appropriate name of Cambrian rocks. Mr. Sharpe did not map the district in detail, but he traced two sections to show the position of the Bala beds with regard to the Berwyns, as he considered the question to turn upon the accuracy or error of the statement of Mr. Murchison, p. 308, " that the Bala limestone dips under the chief mass of the Berwyns." The first section begins westward, at the igneous chain of Arenig Mawr, the natural boundary to the district ; it crosses the town of Bala, and ends eastward at the Calettwr, where a dark slate, the upper bed of the Bala series, abuts unconformably against the clay- slate of Moel-halog, which is referred to the Cambrian system. This section places the Bala beds in a detached trough, and shows that they do not dip under the Berwyns : but their succession is not well shown, owing to the disturbed state of the surface. The other section is in two parts ; from the head of the lake of Bala up the Twrch to Bwlch y Groes, and across the Dyfi by Dinas Mowddy and Mallwyd, which line the author recommends to those who wish to study this series, as the rocks are well exposed in the upper part of the valleys of the Twrch and Dyfi : on the west it begins at the northern prolongation of the igneous chain of Arran Mowddy, and continues eastward through a conformable succession of beds up to the Upper Silurian ; each section shows the whole of the Bala series, the upper bed of blue slate, which on the Calettwr rests unconformably against the Cambrian clay-slate, being the same which is overlaid conformably beyond Mallwyd by an Upper Silurian series of soft blue or liver-coloured shales alternating with hard, grey grits, without cleavage or fossils, dipping east-south-east, which Mr. Mr. D. Sharpe on the Bala Limestojie. 527 Sharpe identifies with the No. 2. of Mr. Bowman's lower division of the Upper Silurians, the probable equivalents of the Wenlock shale. Mr. Sharpe then describes the Bala series of rocks, beginning with the uppermost beds. 1 . Dark blue slate. — Worked at Craig Calettwr for good roofing- slates and flags ; in one quarry the beds dip W.N.W 35°, and the cleavage planes dip W.N.W 65° ; in another the beds dip W. 70° and the cleavage W. 80°. Between Dinas Mowddy and Mallwyd it is largely quarried for good slate and flags ; the beds dip S.E. or E.S.E. about 30° ; the cleavage is perpendicular, and strikes S.S.W. The lower beds pass into a soft argillaceous slate of no value. The whole is not less than 300 or 400 feet in thickness. 2. Upper Bala limestone. — A dark blue bed ten feet thick, accom- panied by calcareous slates and soft brown shales, with many fossils, among wbich are Orthis canalis and O. compressa, and several new species. Mr. Edward Davis, who accompanied the author, discovered this bed at Pen-y Dall Gwm, four miles south-east of Bala, dipping W.^S. 70° : it is supposed to follow a line bearing N.N.E., much broken up by faults*. 3. Rotten argillaceous schist and indurated shale. — Light grey, weathering to brown, with many joints and few fossils ; well exposed in the valley of the Dwm-lach, above its junction with the Dyfi : 400 feet thick. 4. Bala limestone. — A dark blue rock similar to No. 2, thirty or forty feet thick, with calcareous shales and grits full of organic re- mains, among which are Orthis pecten, anomala, vespertilio and bi- lobata, Leptcena sericea, duplicata and depressa, and Spirifer radiatus. This bed is much broken, and difficult to trace, but its general direc- tion from Y-Garnedd, 1| mile east of Bala, to the upper valley of the Cowarch, is nearly N.N.E. The line of limestone laid down, both in Mr. Murchison's and Mr. Greenough's Maps, is compounded of the beds No. 2. and No. 4. 5. Grey slaty grits. — Occasionally streaked or passing into brown, very hard ; well seen on both sides of the lake of Bala and in the upper part of the valley of the Twrch ; usual dip E.S.E. 45°, but much disturbed about the foot of the lake : the upper bed contains Orthis canalis, anomala and vespertilio. In the lower part is a bed thirty or forty feet thick of impure grey limestone with many frag- ments of Trilobites and other organic remains, among which Mr. Sharpe recognised Bumastus Barriensis, Trinucleus Caractaci, Illcenus crassicauda, Orthoceras approximatum, and Lituites cornu-arietis. This bed was only seen near Rhiwlas and Llan-y-ci, on the north-west of Bala. The grits below the limestone are similar to those above, and contain Orthis canalis and vespertilio, Leptcena sericea and Asaphus tyrannus. The whole exceeds 500 feet in thickness. 6. Rotten grey clay-slate, weathering to brown, forming the moor between Bala and Arenig, and exposed where Cwm Croes joins the valley of the Twrch : supposed to be 500 feet thick. * Mr. J. B. Morris has since met with the same bed in the valley of the Dyfi at Blaen-y-Pennant. 528 Geological Society. 7. Dark blue slate, of poor quality, covers the eastern flanks of Arenig and Arran Mowddy, quarried at Blaen-y-cwm, where the beds dip N.E. 35°, and the cleavage dips E.N.E. 55°: the lowest bed of the series. As the Bala beds are quite unconnected with the Cambrian rocks of the Berwyns, and are only overlaid by Upper Silurian deposits ; as most of their organic remains are known Lower Silurian species, and as the total thickness of the whole series is about the same as has been assigned by Mr. Murchison to the Lower Silurians, Mr. Sharpe concludes that they are the exact equivalents of the Lower Silurian formation, and do not carry the series down below the beds described by Mr. Murchison. Mr. Sharpe considers it as easy to prove their identity with the Caradoc sandstone as with the Llandeilo flags, and again endeavours to show that these must be regarded as the same formation under different names. This classification re- places the dark blue limestones of Bala and Coniston, on the same parallel from which they were separated when Professor Sedgwick adopted Mr. Marshall's view of the Silurian age of the Coniston limestone, but left the Bala limestone in its erroneous position as part of the Upper Cambrians. Mr. Sharpe adds comparative tables of the Silurian system as ex- hibited in three different districts : — in Westmoi'eland, as observed by himself; in Denbighshire and Merionethshire, the upper part taken from Mr. Bowman's memoirs, the lower added by himself; and in Shropshire, &c, as described by Mr. Murchison ; but he de- fers the full comparison of these till he lays before the Society the conclusion of his remarks on Westmoreland. Mr. Sharpe hopes that he has done away with an objection often made to the Silurian system, that it wanted a definite base, and was not distinctly separated from the Cambrian system ; this was not over- looked by Mr. Murchison, who states that the line drawn between the two systems was provisional. The difficulty arose from classing with the Cambrian system many beds belonging both to the Upper and the Lower Silurians, and it will vanish when this is corrected ; the lower boundary of the Silurian system will then prove as distinct in North Wales as in Westmoreland and Cumberland ; but to pro- duce this result, the country west of Llangollen and Welsh Pool must be remapped. Of the district now coloured as Upper Cambrian a small share will be given to the Ludlow and Wenlock formations, a larger portion to the Lower Silurians, and certain central bosses of older rocks will remain for the Cambrian system : but the Upper Cambrian of Professor Sedgwick, and its representative in Mr. Greenough's nomenclature, the upper division of the Lower Killas, must be struck out of our tables, and the Lower Silurians made to rest on the true Cambrian rocks. The igneous rocks of Arenig and Arran Mowddy are described as varying compounds of felspar and quartz. The two chains bear nearly north, and their eruption is supposed by the author to have modified the face of the country, and to have caused much of its pre- sent complication, the prevailing strike previously having been N.N.E. The Rev. P. B. Brodie on Insects in the Lias. 529 In the absence of direct evidence on the subject, Mr. Sharpe en- deavours to prove that Arenig and Arran Mowddy are at least as modern as the Ludlow rocks, by showing that the upheaving of these chains has broken up the parallelism of the cleavage planes of the slaty rocks resting on them : assuming that these planes had originally a constant direction in each district, their dislocation at any spot would show that it had been disturbed subsequently to the cessation of the cleavage process, and we may thus class igneous eruptions as prior to, or posterior to, the cleavage ; and may then connect them with the deposition of the formations, by observing at what epoch the cleavage ceased in the district. In North Wales and in Westmoreland, the cleavage only reaches into the Lower Ludlow formation ; in Devonshire and Cornwall it continued later : therefore Arenig and Arran Mowddy must have been upheaved after the epoch of the Lower Ludlow shale. The memoir concludes with a general list of the species of fossils found near Bala. " Notice on the discovery of the Remains of Insects in the Lias of Gloucestershire, with some remarks on the Lower Members of this Formation." By the Rev. P. B. Brodie, F.G.S. The lower beds of the lias, in which these organic remains occur, are extensively developed in the neighbourhood of Gloucester and Cheltenham, and occupy the greater part of the vale. In the upper part of the lower beds, in a hard blue limestone, was found the ely- tron of a coleopterous insect of the family Buprestidce, apparently a species of Ancylocheira of Escholtz. This was the only fossil of the kind met with by Mr. Brodie in this portion of the lias. With this exception, the numerous fossil insects he has obtained occur in the bottom parts of the lower beds near the base of the lias, which are seen at several points in the neighbourhood of Gloucester. At Wainlode Cliff, the lower beds of lias, resting on red marl, form a bold escarpment on the south bank of the Severn, and afford the following section in descending order : — 1. Clay; 3 ft. 2. Blue limestone, with Ostrea, &c. (the "bottom bed"): 4 in. 3. Yellow shale with fucoid plants: 6 in. 4. Gray and blue limestone, termed by Mr. Brodie "insect lime- stone " from its characteristic fossils, passing into yellow shale above, where it is nearly white, and has the aspect of a fresh- water limestone : 3 to 5 in. 5. Marly clay : 5 ft. 3 in. 6. Hard yellow limestone, with small shells like Cyclas, plants and Cypris : 6 to 8 in. 7. Marly clay: 9 ft. 6 in. 8. Bed with fucoid bodies : 1 in. 9. Shale: 1ft. 6 in. 10. Pectenbed: 4 in. Nine feet below this is the bone-bed, 20 feet above which is the yel- low Cypris limestone, and 26 feet 2 inches the insect limestone. The total height of the cliff is about 100 feet. Phil. Mag. S. 3. No. 155. Suppl. Vol. 23. 2 M 530 Geological Society : Mr. Strickland The insect remains consist chiefly of elytra belonging to the seve- ral genera of Coleoptera, which are not very rare ; and a few wings, not unlike the genus Tipula, which bear a close resemblance to some Mr. Brodie had previously found in the Wealden ; the latter are much rarer than the former. The elytra are generally of a light brown colour and small size ; in some cases both the elytra are at- tached. With these were found abdomens of some insects and larva apparently of the gnat tribe. Shells are not common, but Ostrea, Unio, and a small species of Modiola are the most abundant. The fossils from the yellow limestone, No. 4, bear a close resemblance to those from the Wealden. The real genus of the bivalve resembling Cyclas is undetermined. The plants belong to a species of Fucus, apparently an inhabitant of fresh water. At Combe-hill Mr. Brodie also observed both the insect limestone and that containing the small bivalves. To the south-west of this point the insect limestone is well seen, and yielded the greatest number and variety of insect remains. Here the yellow limestone was not traced, and the bone-bed was want- ing. The fossil insects are, as at Wainlode Cliff, for the most part re- mains of small Coleoptera, sometimes tolerably preserved, and in one specimen the eyes were visible. None of the beetles resemble those of the Wealden, but some wings of insects, allied to Tipula, are very similar. A few imperfect but large wings of Libellula occur : there are also numerous singular impressions of a doubtful nature, many of which may however owe their origin to the partially decomposed bodies of various insects. With these are numerous small plants, some resembling mosses, but very different from those in the yellow Cypris limestone, a few seed-vessels and leaves of fern. A small spe- cies of Modiola, probably M. minima, is exceedingly abundant. Re- mains of Crustacea occur, one of which resembles the genus Eryon from the Solenhofen slate. Near Gloucester the same strata occur at a much lower level. At Westbury, eight miles below Gloucester, the following section is presented : — 1. Bottom bed with Ostrea, equivalent to that at Wainlode and other places : 3 in. 2. Insect limestone with numerous small shells (here character- istic) : 4 in. 3. Clay: 5 in. 4. Green, yellow and gray sandy stone, in places becoming a limestone, with the small Cyclas-like bivalve, plants and Cypris, identical with those at Wainlode, about 1 ft. 5. Shale and clay : 10 ft. 6. Hard grit, bone-bed : 3 or 4 ft. A little further to the north the beds below this are more developed and are seen resting upon the red marl. If the Cypris found in these beds be of freshwater origin, it forms a new and highly interesting feature in the history of this deposit ; at any rate the occurrence of the remains of such delicate creatures as insects, many of which are well-preserved, and could not, there- fore, have been long subject to the action of the waves, or have been on Impressions in the Lias bone-bed in Gloucestershire. 531 carried far out into the water, gives a greater probability to the sup- position that this part of the lias may have been formed in an estuary which received the streams of some neighbouring lands, perhaps nu- merous scattered islands, and which brought down the remains of insects, Ci/pris, and the plants above referred to. The shells usually found in the insect limestone are Modiola and Ostrea, both of which frequently inhabit estuaries, and are capable of living in brackish water as well as in the open sea. The shells, however, so abundant at Westbury in the same stratum are exclusively of marine origin ; the wing of a dragon-fly from Warwickshire is a solitary instance of its kind. Mr. Brodie observes, that such stray specimens had pro- bably been carried out to sea, which might also have been the case with a small wing he discovered in the upper lias at Dumbleton near Tewkesbury ; which also proves the existence of insects during the deposition of the upper portions of this formation. Thus it will be seen that the remains of insects are of very rare occurrence in the upper beds, and in the higher portions of the lower ones in the lias, while at the base near its junction with the red marl they are abundantly distributed. The discovery of small elytra of coleopterous insects and portions of the wings of Libellula in the lower division of the lias near Evesham, by Mr. H. E. Strick- land, shows that these fossils are characteristic of the same beds in distant parts of the system. " On certain impressions on the surface of the Lias bone-bed in Gloucestershire." By H. E. Strickland, M.A., F.G.S. The singular markings described, which the author in a former communication suggested might be caused by the crawling of Crus- tacea, but which further opportunities and observations have induced him to refer to a different cause, have been noticed only at Wain- lode Cliff on the Severn. There they occur on the uppermost sur- face of the band of micaceous sandstone which represents the " bone- bed," and which appears to have consisted of a fine-grained muddy sand, capable of receiving the most minute impressions, while the pure black clay which forms the superincumbent stratum has pre- served this ancient surface in the most unaltered condition. The ripple- marks produced by currents on the surface of this bed of sand are very interesting, from their perfect preservation, and from often exhibiting two sets of undulations oblique to each other, indicating two successive directions in the currents, such as would result from a change of tide. The impressed markings were evidently produced by living beings, probably by fish or invertebrate animals. To determine their nature Mr. Strickland observed the progression of two species of Littorina among Gasteropodous Mollusca, and of Carcinus Manas among Crus- tacea, but the impressions produced were very different from those under consideration. The fossil impressions are of four kinds : — 1st. Lengthened and nearly straight grooves, about one-tenth of an inch in width, and several inches long, very shallow, with a rounded bottom. These, Mr. Strickland considers as caused by 2 M 2 532 Geological Society : Mr. D. Sharpe on the some object striking the surface of the sand with considerable impe- tus. They may often be seen to cut through the ridge of one ripple- mark, and after disappearing in the depressed interval, they are again seen pursuing their former direction across the next ridge. They may have been caused by fish swimming with velocity in a straight direction, and occasionally touching the bottom with the under part of their bodies. 2nd. Small irregular pits averaging one-fourth of an inch wide and one-eighth of an inch deep. These might have been caused by some small animal probing the mud and turning up the surface in quest of food. Mr. Strickland conjectures that some of the numerous species of fish found in the bone-bed may have produced them, the heterocene form of tail common to most of which, Dr. Buckland has suggested, enabled them to assume an inclined position with the mouth close to the ground. 3rd. Narrow deep grooves, about one-twelfth of an inch in width, the sides forming an angle at the bottom, irregularly curved and often making abrupt turns, apparently formed by a body pushed along by a slow and uncertain movement, such as might arise from the crawling of Mollusks. Mr. Strickland refers them to the loco- motion of Acephalous Mollusca, and supposes that the only shell found in this bed, a small bivalve named by him Pullastra arenicola, might have produced them*. 4th. A tortuous or meandering track consisting of a slightly raised ridge about one-tenth of an inch wide, with a fine linear groove on each side. These tracks are analogous to those formed by the crawling of small annelidous worms, as may often be seen on the mud of the sea or fresh water. About eleven feet above the stratum which presents the impres- sions above described, a second ossiferous bed occurs at Wainlode Cliff, which escaped Mr. Strickland's notice in the section formerly given (Geol. Proc. vol. iii. p. 586). It is a band of hard, grey, slightly calcareous stone, about an inch thick, containing a plicated shell resembling a Cardium, and scales and teeth of Gyrolepis tenui- striatus, Saurichthys apicalis, Hybodus Delabechei, Acrodus minimus, and Nemacanthus monilifer, all of which occur in the true " bone- bed" below. On the upper surface of that bed are numerous im- pressions, termed by Mr. Strickland fucoid, consisting of lengthened wrinkled grooves, variously curved, about three quarters of an inch wide, one-eighth Of an inch deep, and of variable length. The bone-bed seems to be a local deposit, not being met with in the other localities examined by the author, and being confined to a portion only of Wainlode Cliff, where it constitutes No. 9. in the following corrected section : — * Mr. Strickland describes this species as follows : — " Its form is nearly a perfect oval, depressed, nearly smooth, but with faint concentric striations towards the margin. The apex is about halfway between the middle of tbe shell and the anterior end. The general outline closely resembles that of the recent Pullastra aurea of Britain. Maximum length 7 lines, breadth 4£ lines, but the ordinary size is less." Silurian Rocks of Westmoreland and North Lancashire. 533 Ft. in. 1 . Blackish lias clay 3 6 2. Limestone, with Ostrea and Modiola mini- ma (the hottom bed) i. ... . 0 4 3. Yellowish shale I 0 4. Limestone, with remains of insects 0 4 5. Marly shale and clay 5 3 6. Yellowish limestone nodules, with occasional remains of Cypris 0 6 7. Yellowish marly clay 6 0 8. Black laminated clay 3 6 9. Stone, with scales and bones of fish, and on the upper surface fucoid impressions. ... 0 1 10. Black laminated clay 1 6 11. Slaty calcareous stone, with Pectens 0 4 12. Black laminated clay 9 0 13. Bone-bed and white sandstone, with casts of Pullastra arenicola 0 3 14. Black laminated clay 2 0 15. Greenish angular marl 23 0 16. Red marls with greenish zones 42 0 98 7 December 14, 1842. — On the Ridges, Elevated Beaches, Inland Cliffs and Boulder Formations of the Canadian Lakes and Valley of St. Lawrence. By Charles Lyell, Esq., V.P.G.S., F.R.S. January 4, 1843. — The reading of Mr.Lyell's memoir, commenced on the 14th of December, was resumed. An abstract of it has already been given, see p. 518, note. Notice on a Suite of specimens of Ornithoidicnites, or foot-prints of Birds on the New Red Sandstone of Connecticut-" By Gideon Algernon Mantell, LL.D., F.R.S. * Extract of a Letter from W. C. Redfield, Esq., on newly dis- covered Ichthyolites in the New Red Sandstone of New Jersey. Communicated by Charles Lyell, Esq., V.P.G.S.* A Letter was read from Mr. Charles Nicholson, accompanying some fossil bones found imbedded in the banks of the Brisbane River (New South Wales). Also an extract of a Letter from his Excellency George Grey, Governor of Adelaide, to Mr. Lyell, accompanying a section of the country between the eastern shore of St. Vincent's Gulf and Lake Alexandrina (New South Wales), and noticing some fossils obtain- ed from that district. January 18th, 1843.—" On the Silurian Rocks of the South of Westmoreland and North of Lancashire." By Daniel Sharpe, Esq., F.G.S. This communication is in continuation of a paper read by the au- thor on the 2nd of February, 1842f, a second visit to the district * Abstracts of these papers have already been given, see p. 518, note, t See Phil. Mag. S. 3. vol. xxi. p. 555. 534 Geological Society: Mr. D. Sharpe on the having enabled him to correct some errors committed on his first examination, and to extend his observations into Lancashire. On both occasions Mr. Sharpe took for his base-line the bed of Coniston limestone described by Professor Sedgwick*, being con- vinced that Mr. Marshall has rightly considered that limestone as the lowest bed of the Silurian system in this districtf, and in all his descriptions he adheres to the ascending order. 1st. Coniston Limestone. — It is doubtful whether this bed is continuous at its western extremity, or occurs only in detached patches. The two western portions of limestone at Water Blain and Low House are a mile and a quarter south of the bearing of the line of the bed east of the latter place, but are exactly on a line with the strike of the bed beyond Coniston ; a great fault between Low House and Greystone House being counterbalanced by the whole of the smaller faults between that spot and Coniston, which are pointed out in Professor Sedgwick's memoir. Mr. Sharpe gives a list of fossils collected in this bed and the shales above it at Torver Fell, Coniston, Long Sleddale, &c, in which are several of the spe- cies of Orthis, Spirifer, and Leptana, found by Mr. Murchison in the Lower Silurian deposits, and several undescribed species. 2nd. Slates, Shales, and Flagstones. — These are well exposed on Torver Fell, where the following series may be seen: — a. Brown shale. b. Dark blue slate of good quality ; the beds dip E.S.E. 40°, and the cleavage dips S.S.E. 80°; it contains many fossils, much com- pressed and distorted, nevertheless a few Lower Silurian shells are made out. c. Indurated brown shale. d. Blue flagstone rock, a bed well known in the district, and mentioned by Professor Sedgwick and Mr. Marshall ; at Torver, where it gives good roofing-slate as well as flags, the beds dip south-east 45°, and the cleavage south-east 80°. To the eastward of Windermere this bed and the lower bed of slate b run together, and the whole of the Lower Silurian formation diminishes in thick- ness. e. Indurated shale. /. Shear Bed, which supplies brownish-blue flags, taken along the bedding of the rocks, which is free from slaty cleavage. This series of slates, flagstones, and shales, may be traced above the Coniston limestone from the Dudden to Shap Fells, although the separate beds cannot always be distinguished. 3rd. Grey Slaty Grits, described in Mr. Sharpe's former paper as the " Lower division of the Windermere rocks," but now classed as part of the Lower Silurian formation ; they consist of a great thickness of hard gritty grauwacke, variously affected by cleavage, and may be traced from the Dudden, below Broughton, to Shap Fell. 4th. Blawitk Limestone, "the second band of calcareous slate" • Geol. Trans. Second Series, vol. iv. p. 47- f Report of the British Association, 1839, Sections, p. 67. Silurian Rocks of Westmoreland and North Lancashire. 535 of Professor Sedgwick ; a bed only found in two localities, at Meer Beck and a wood behind Low Hall, on the east of the road from Ireleth to Kirkby Ireleth, where it is a dark-blue limestone very like that of Coniston, dipping east 40°, of which only about a thick- ness of twelve feet is laid open ; and at Turtle-bank Heights, south- west of Blawith, where it has been quarried near the top of the south-east face of the hill, and is a dark gray limestone, twenty feet thick, striking north-east and dipping perpendicularly; from this spot it runs by Cockin's-hill to the side of Coniston Water, half a mile north of Water Gate. The fossils found by Mr. Marshall in this bed near Blawith were identified as Lower Silurian species. 5th. Flagstones and Slates of Kirkby Ireleth. — These are placed by Professor Sedgwick below the Blawith limestone, No. 4, but as Mr. Sharpe considers erroneously : nevertheless, although no fossils have been found in them, he considers them to be the upper- most bed of the Lower Silurian series, because they are always con- formable to the undoubted Lower Silurian beds below them, and are not equally conformable to the bedsabove. As this southern edge forms the boundary line of the Lower Silurian formation, Mr. Sharpe traced them carefully along their whole course, from their first appearance rising from under the mountain limestone, on the east of Ireleth, till they are hidden by the old red sandstone of Birkbeck-beck. Near Ireleth it is only used for building- stone, but at Kirkby Ireleth are quarries extending for a mile and a half along the range of the bed, supplying dark-blue slates of very good quality. At Horse Spital Quarry the beds dip south-east 80°, and the cleavage dips south-east 55°, both sets of planes striking north-east : this coincidence in the strike of the bedding and cleavage planes is common in all this district; yet at Lord Quarry, close to the last-mentioned, the beds dip N.N.E. 20°, while the cleavage dips S.S.E. 70°. Further east the rock is of inferior quality, and is rarely worked for roofing- slate: its usual course is north-east, passing by Suberthwaite, Blawith, Nibthwaite, at the foot of Coniston Water, where much building- stone has been quarried, and the rock is well exposed, being a dark- blue flagstone streaked with gray : between Oxen Park and Satter- thwaite it dips north 50°, and N.N.W. 70°, and is lighter and more striped than usual ; at Force Mill it strikes E.N.E. and dips N.N.W. 65°, and the cleavage has the same strike but is perpendicular : at Satterthwaite the dip is north 45° : between Esthwaite and the Ferry on Windermere the road runs near the upper edge of the bed, which is well exposed close to the Ferry House, north of which spot it reaches more than a mile up the shore of the lake. On the east side of the lake it has been quarried north of Bowness. Eastward of Bowness, Mr. Sharpe corrects an error which he committed in laying down this line too far south : he now traces it nearly E.N.E. by Ing's Chapel, Row Gill, and Hugill Hall, dip south-east 60° ; Monument Hill on the west side of Kentmere, dip S.S.E. 80° to Fellfoot in Kentmere. The flagstone crosses Long Sleddale at the Chapel, where it was found not worth working for slate : at Bonnisdale-head Farm it gives a slate of fair quality, the 536 Geological Society : Mr. D. Sharpe on the beds dip south-east by south 65°, and the cleavage dips in the same direction 80° ; from here it crosses into High Borrowdale half a mile above High House, dipping south-east by south 50° ; a fault down this valley throws the bed below High House on the east side of the valley : in the next Fells it is much concealed by the vegetation, but it is seen at a cutting of the road from Shap to Kendal on Hurd's Brow, between the ninth and tenth milestone, dipping south-east 75°, and the cleavage dipping north-west 85°. Near the Borrow the beds are thrown into several anticlinal ridges bearing north-east, by faults which disturb the cleavage planes as well as the bedding of the rock : this slate has also been worked in the upper part of Bretherdale. The boundary thus laid down nearly corresponds with that given in the new edition of Mr. Greenough's map. The lowest beds of the slate in High Borrowdale are calcareous, and may perhaps represent the Blawith limestone, which has not been found in conjunction with the slate eastward of Blawith. In High Furness, the district of Lancashire consisting of Lower Silurian rocks, the principal valleys run from south-west to north- east, parallel to the strike of the beds, each ridge of hills repre- senting the outcrop of a particular bed : this is not the case with the same formation in Westmoreland, where the valleys of Coniston Water, Esthwaite, Windermere, Troutbuk, Kentmere, Long Sled- dale, Bannisdale, High Borrowdale, and Brethesdale, all follow great faults across the strike of the stratification : these faults are con- tinued through the Windermere rocks, and sometimes into the Lower Ludlow rocks, but are lost before entering the Upper Ludlows. It is in High Furness that the Lower Silurian formation is best ex- posed to observation, and has a greater thickness than in Westmore- land, the beds gradually diminishing in their course eastward. In the same district of Lancashire the slaty character of the rocks is more developed than we find it in Westmoreland ; it is especially between Coniston, Old Mere and Kirkby Ireleth, that the crystal- lizing agency which has changed the rocks into slate has acted most powerfully, many beds in that district supplying good slate, which will hardly split up at all elsewhere. From the prevailing parallelism long known to exist between the planes of slaty cleavage over considerable areas, Mr. Sharpe considers it nearly certain that these planes had a uniform direction in each district, and that the cases of exceptions which are found are due to disturbing forces acting after the cessation of the cleavage action. In the district under consideration the mean dip of the cleavage planes is considered to be S.S.E. 70°, and the cleavage action is thought to have ceased before the formation of the Upper Ludlow rocks. Windermere Rocks. — The beds formerly classed by the author as the lowest division of this series are now placed in the Lower Silurian formation, and the middle and upper divisions are thrown together, for want of any distinct line of division between them, and some considerable corrections are made in their geographical boundaries. They rise, near Ulverston, from below the mountain limestone of Silurian Rocks of Westmoreland and North Lancashire. 537 Low Furness, dipping E.S.E. at high angles, and disappear in West- moreland beyond Bannisdale, during which course they rest on the Kirkby Ireleth slate ; but their southern boundary can only be under- stood from the map, as to the west of Windermere they are over- laid by large patches of mountain limestone, and in their range east- ward are gradually covered up unconformably, and concealed by the Lower Ludlow rocks. In some places the similarity of the rocks of the two formations, and the absence of fossils in both, makes it diffi- cult to determine the boundary between them, the best guide being the dip and strike of the rocks. In Mr. Sharpe's first map a portion of the Lower Ludlow rocks on the north-east of Kendal was errone- ously coloured as belonging to the Windermere series ; the error was pointed out by Cornelius Nicholson, Esq., of Cowan Head, who assisted the author materially in mapping the neighbourhood of his residence. The upper boundary of the Windermere rocks begins on the south- west at the lower point of Witherslack, and is marked by a great fault which crosses the valley between that hill and Whitbarrow, and appears to pass under the mountain limestone of Whitbarrow, then runs north-east through Underbarrow, by the Chapel, to Mount- joy : on the west side of this fault the Windermere rocks form high ridges of hard slaty grits of dark grey colour, with lighter streaks, dipping N.N.W., while on the east side of the fault is a gritty rock of uniform grey colour dipping E.S.E., overlaid with beds containing the fossils of the Ludlow beds. From Mountjoy the line turns to the north-west, and passes round Crook Chapel, which stands on a ridge of the Windermere grits ; at Crook Common it turns to the north-east, and follows that direction to near Borrowdale, where the formation is lost, being completely hidden by the Ludlow rocks, which there rest on the Lower Silurians. Crook Common is thrown into great confusion by the meeting of two lines of elevation, one coinciding with the E.N.E. strike of the Lower Silurian rocks, the other coming up from the S.S.W. through Cartmel Fell. At Backbarrow, below Newby Bridge, the upper beds of this series are slaty, with a wavy cleavage dipping N.N.E. 80°, the beds dipping south-east 80° ; these beds contain irregular calcareous nodules in great abundance, and Orthoceras articulatum was found in them. Mr. Sharpe refers to his former memoir for the description of the Windermere rocks on the east of the Lune, which extend to Grey- rigg Forest, Whin Fell, and Howgill Fell ; in these Fells are several axes of elevation which require further examination. Ludlow rocks. — These were described in the author's former paper ; the area covered by them is larger than was there stated, their lower boundaiy being now carried more to the north, and their eastern portion being extended in a sort of trough between the Lower Silu- rian slates of Shap Fell and the Windermere rocks of Whin Fell, crossing Barrowdale between High and Low Barrowbridge. In the lowest beds of the series in Fawcett Forest were found Lcptcena lata and Turritella conica, in a slaty rock. The Terebratula navicula is found thinly scattered throughout all the lower part of the 538 Geological Society. formation, and occurs in vast numbers in a bed which forms about the middle of the Ludlow series. Mr. Murchison has told us that this little shell is usually found in such numbers as to form a bed which lies above the Aymestry limestone, and it serves to mark the place of that rock where it is wanting : and Mr. J. E. Davis informed the author, that at Stapleton, near Presteign, where there is no Aymestry limestone, this species is found throughout the whole of the Lower Ludlow shales. Mr. Sharpe has made use of this shell in dividing the Upper from the Lower Ludlow rocks in Westmore- land, classing all the beds containing it in the lower series. The bed in which it occurs in greatest abundance was traced through Underbarrow, by Tullithwaite Hall and High Cray, across the west end of Rather Heath and a little south of Cowan Head, and also in Lambrigg Park ; it is usually accompanied by Atrypu affinis, Spirifer octoplicatus, Leptozna lata and depressa, Orthis lunata, and Terebratula nucula : the T. navicula seems to have died out -suddenly, as it is not found in the Upper Ludlow beds. The same division of the Ludlow rocks may be obtained by attend- ing to the direction and dip of the beds ; the lower series partakes of the north-east strike, which runs through the older Silurian rocks in these counties, and is traversed by many of the same faults as those formations, but the Upper Ludlow beds are thrown up in anti- clinal ridges with a different direction. Mr. Sharpe gives a list of the organic remains found in each divi- sion of the formation, which includes forty-four of the species de- scribed in Mr. Murchison's work from the old red sandstone and Upper Ludlow, fourteen of those from the Aymestry limestone, and twenty-two of those from the Lower Ludlow beds. Of the species of shells placed by Mr. Murchison in the old red sandstone*, all but two have now been found low in the Ludlow beds, proving that the red beds containing these species in Herefordshire must be elassed with the Upper Ludlow formation. Old Red Sandstone. — The only addition to the former paper which relates to this formation, is in mapping it in the upper valley of the Lune, where the tile-stones reach above the hamlet of Langdale, dipping N.N.E. 10°. The age of the large masses of gravel of a brown or red colour noticed in the valley of the Lune between Sedberg and Casterton, and of the Kent and Sprint, was before left uncertain ; the author now regards them as a modern surface drift. Mountain Limestone. — The description of this formation did not enter into Mr. Sharpe's plan, but he examined the portion of it which occurs in Low Furness, to ascertain the geological position of the Ulverston iron ore. The ore occurs in veins usually perpendicular, and bearing W.N.W., which cut through the limestone, but are not continued into the Silurian rocks. The following veins are mentioned : — Plumpton Hall ; now abandoned. Lindal Moor vein ; an exception to the usual condition, as it runs between the mountain limestone and the Windermere grits, striking * Silurian System, p. 603. and t. 3. Mr. Stevenson on the Stratified Rocks of Berwickshire. 539 north-west and dipping south-west 45° ; it is the principal and most profitable vein of the district. Stainton ; three veins separated by a few yards of clay, spar, and limestone, perpendicular, and bearing W.N.W. Lindal Court ; several perpendicular veins near together, bearing W.N.W. Crosthwaite ; a poor vein bearing W.N.W., thought to be the continuation of that at Stainton. Wet Flat ; the rocks near are much disturbed, and the vein, after running W.N.W., turns down a fault in the limestone to N.N.W., but soon thins out. Trap Rocks. — These are rare in the district ; Professor Sedgwick has laid down some masses of igneous rocks at Shap Fells, on the south side of the high road ; one of them consists of red felspar with some mica, quartz, and hornblende. The slate rocks are much disturbed in the neighbourhood, and the faults have broken up the cleavage planes as well as the bedding of the rocks, from which Mr. Sharpe infers that the trap is more modern than the eruption of the Shap gra- nite, which took place before the cleaving of the slates, as the cleavage planes run through all the faults connected with that eruption. At Biglands, south of Newby Bridge, there is a trap dyke running north-east, which has also disturbed the parallelism of the cleavage, and must be considered as of a modern date : it is not well exposed on the surface. The author concludes by a comparison of all the beds with those described by Mr. Murchison in the border counties of Wales, and adopted as the types of the Silurian system, and with those of Den- bighshire and Merionethshire, to which his attention was directed by Mr. Bowman's papers on Llangollen ; he points out the closest re- semblance between the Silurian formation in North Wales and in Westmoreland, while in mineral character they differ most mate- rially from those of Siluria : nevertheless the principal divisions of the Silurian system laid down by Mr. Murchison can be traced in each district by the evidence of the organic remains. " On the Stratified Rocks of. Berwickshire and their imbedded Organic Remains." By Mr. William Stevenson, of Dunse. Com- municated by the President. In this memoir the author gives an account of the characteristic features, the order of succession, and the nature of the organic re- mains of the stratified rocks of Berwickshire. The lowest of these are greywacke and greywacke slate, forming an extensive system of arenaceous and argillaceous strata of various colours, gray predo- minating, found almost everywhere among the Lammermuirs, of which chain they constitute the fundamental rock. In the rocks of this system no undoubted organic remains have been found, but some curious markings occur on slabs, for which it is difficult to ac- count without supposing the influence of organic agency. The grey- wacke presents the uniform appearance of a deep sea deposit, per- haps laid down upon the bottom of a wide-spreading ocean of great profundity, and therefore removed from the disturbing action of wind and tides. The thickness of these strata, as displayed among 540 Geological Society : Dr. Mantell the Lammermuirs, is very great, but the series is far from being com- plete, there being no appearance of the older strata on the one hand, and on the other their junction with the newer formations is always unconformable. The materials of which they are composed were pro- bably derived from the disintegration of the granites and primary schists to the westward. 2. The formation next in order is the upper division of the old red sandstone, the members of which rest unconformably upon the upturned ends of the greywacke. The lowest member of it is an old red sandstone conglomerate, consisting of fragments of grey- wacke and felspathic rocks, cemented by a paste which is generally arenaceous, sometimes calcareous. It varies much in thickness. 3. Red and greenish white sandstones succeed with soft red ar- gillaceous strata. Part of these seem to have been formed in a shal- low sea, since they exhibit ripple-marks, and contain remains of Holoptychius and Dendrodus. Another portion contains few traces of fossils, and was probably deposited in deeper water. Some curious spindle-shaped concretions and the impressions called Kelpie's feet occur, also traces of Fuci. Two localities near Preston-Haugh, and one at the foot of the Knock-hill, are all in which organic remains have as yet been found. 4. After the deposition of the strata containing the remains of the Holoptychius, &c, a subsidence to a considerable extent took place, after which a succession of strata of great thickness was de- posited above them. These rocks seem to have been formed in deeper water than the ichthyolitic beds. They consist of red and greenish white sandstones interstratified with beds of a softer and more argillaceous character, and of a deep red colour. They seem to contain no organic remains except vegetable impressions (Algee ?) which occur in abundance in a bed of red sandstone, perhaps 100 feet above the strata containing the animal remains. 5. Above the soft, red and white sandstones are calcareous shales, sandstones and cornstones, or impure concretionary limestones, with- out fossils. The junction of these with the sandstones is not seen, being cut off by faults and trap dykes. 6. The lower portion of the coal-measures succeeds, consisting of shales, marls, clays, and sandstones containing ironstone bands and gypsum, and abounding in vegetable fossils, consisting of Conifercc, Stigmarm, Lepidodendra, and other coal plants. This formation is well developed over the greater part of the Merse of Berwickshire. 7 . Next in order are some thick beds of reddish sandstone, under- lying > ■; 8. Carboniferous strata, consisting of sandstones, shales, &c, in- cluding three or four coal-seams. 9. The encrinal limestone, seen a little north of Berwick. Mr. Stevenson remarks that the Berwickshire carboniferous strata appear to correspond with the lower beds of the Fife and Lothian coal-fields, considered by Mr. Milne and others to belong to the mountain limestone, and to be considerably lower than the New- castle coal strata. With regard to the inquiry whether new red sandstone exists in Berwickshire, Mr. Stevenson is inclined to on Fossil Fruits from the Chalk formation. 541 answer it in the negative. He regards the beds at Cumledge, de- scribed by Mr. Milne as such, as old red, and considers the soft red clays and sands at Lintlaw, derived from the disintegration of the old red sandstone, referred by Mr. Milne to the new red sandstone, to be of undetermined age, from want of sufficient evidence in the absence of organic remains. The exact position of the greywacke strata of the Lammermuirs is for the same reason indeterminate. The author concludes by pointing out the great gap which occurs between the greywacke and the upper division of the old red sand- stone in Berwickshire, the middle and lower divisions of the old red and the whole of the Silurian system being deficient. Another cir- cumstance worthy of remark is the absence of any formations more recent than the coal-measures, if we except alluvial deposits and the undetermined red strata formerly mentioned. February 1, 1843. — A paper was read " On the Tertiary Strata of the Island of Martha's Vineyard in Massachusets." By Charles Lyell, Esq., V.P.G.S., &c* Letter from J. Hamilton Cooper, Esq., to Charles Lyell, Esq. V.P.G.S., " On Fossil bones found in digging the New Brunswick Canal in Georgia*. " Description of some Fossil Fruits from the Chalk-formation of the South-east of England." By Gideon Algernon Mantell, LL.D., F.R.S., &c. The fruits described are three in number, viz. — 1. Zamia Sussexiensis, Mantell. — From the greensand. A cone allied to the Zamia macrocephala, a greensand fossil from Kent, figured in Lindley and Hutton's 'Fossil Flora,' pi. 125, from which it differs in form and in the number, size, and shape of its scales, which are more numerous, smaller and more oblong than in the Kentish species. It is five inches long, and at the greatest circum- ference measures six inches. It was found about two years ago in an accumulation of fossil coniferous wood in a sand-bank at Selmes- ton, Sussex, at the junction of the Shanklin sand with the gault. Dr. Mantell having sent a cast of the only specimen found to M. Adolphe Brongniart, that distinguished botanist suggested that it might be either the stem of a young cycadaceous plant or the fruit of a Zamia, but the situation and small size of the stalk at the base and the appearance of the scales, induce Dr. Mantell to refer it to the latter. 2. Abies Benstedi, Mantell. — From the greensand near Maidstone, Kent. A beautiful cone found by Mr. W. H. Bensted in the quarry in which the remains of the Iguanodon were discovered in 1834, where it was associated with Fucus Targionii, and some indetermi- nate species of the same genus ; stems and apparently traces of the foliage of endogenous trees allied to the Dracana (Sternbergia), and of trunks and branches of Coniferee. The wood occurs both in a calcareous and siliceous state. The cone found is in every respect such a frait as the trees to which the wood belonged might have borne. It bears a close resemblance to a fossil from the greensand * Abstracts of these papers have appeared in the present volume; see p. 518, note. 542 Geological Society. of Dorsetshire, discovered by Dr. Buckland, and figured in the • Fos- sil Flora' of Great Britain under the name of Abies oblonga (Fos. Fl. pi. 1.). Unfortunately the outer surface is so much worn that the external figure of the scales cannot be accurately defined ; but the sections show their proportionate thickness. There is an opening at the base of the cone occasioned by the removal of the stalk, and an accidental oblique fracture exhibits the internal structure. In the longitudinal section thus exposed the scales are seen to be rounded and broad at their base and to rise gradually, and become thin at their outer terminations. The seeds are oblong, and one seed is seen imbedded within the base of each scale. Mr. Morris considers it to have a great affinity to Abies oblonga of Lindley and Hutton, but it is more spherical, and the scales are smaller, more regular and numerous. 3. Carpolithes Smithies, Mantell. — From the white chalk of Kent. An account of an imperfect specimen of this fruit was formerly given by Dr. Mantell in his ' Illustrations of the Geology of Sussex.' He lately detected a second and more perfect example in the choice col- lection of Mrs. Smith of Tunbridge Wells, in honour of whom he has named it. Dr. Mantell remarks, that a slight inspection was sufficient to determine its vegetable origin, for several seeds were imbedded in its substance, and others had been detached in clearing it from the chalk. Dr. Robert Brown suggested that the original was probably a succulent compound berry, the seeds appearing to have been imbedded in a pulpy substance like the fruit of the mul- berry, which is a spurious compound berry, formed by a partial union of the enlarged and fleshy calices, each inclosing a dry mem- branous pericarp. From the occurrence of the cones above described with the drifted remains of land and freshwater reptiles peculiar to the Wealden, Dr. Mantell infers that these fruits belong to the flora of the coun- try of the Iguanodon. " Notice on the fossilized remains of the soft parts of Mollusca." By Gideon Algernon Mantell, LL.D., F.R.S., &c. Substances presenting the same general appearance and composi- tion with coprolites, but destitute of the spiral structure, are thickly interspersed among the shells which abound in the rocks of firestone or upper greensand at Southborne in Sussex, sometimes occurring in the state of casts of shells of the genera Cuculleea, Venus, Trochus, iiostellaria, &c, from the soft bodies of which testacea Dr. Mantell considers them to have originated. They abound also in the layers of firestone which form the line of junction with the gault, and are not uncommon in the gault itself in several localities in Surrey and Kent. Dr. Fitton, in his memoir ' On the Strata below the Chalk ' (Geol. Trans, vol. iv. part 2. p. 11), has given an account of similar concretions from Folkstone, where he observed them in some cases surrounding or incorporated with fossil remains, and filling the in- terior of Ammonites. Dr. Mantell has observed them also in the Shanklin sand in Western Sussex, in Surrey, near Ventnor in the Isle of Wight, and in Kent, and they especially abound in the Igua- Intelligence and Miscellaneous Articles. 543 nodon quarry of Kentish rag near Maidstone, belonging to Mr. W. H. Bensted. Mr. Bensted having long paid attention to this subject, more than two years ago submitted to Dr. Mantell specimens of fossil shells, the cavities of which were filled with a dark brown substance in every respect identical with the nodular and irregular concretions of coprolitic matter which abound in the surrounding sandstone. Mr. Bensted expressed his belief that the carbonaceous substance was derived from the soft bodies of the Mollusca, and that the con- cretionary and amorphous portions of the same matter dispersed throughout the sandstone of this bed, were masses of the fossilized bodies of the animals which had become disengaged from their shells, and had floated in the sea till enveloped in the sand and mud, which is now concreted to the coarse sandstone called Kentish Rag. In proof of this opinion reference is made to an account published in the • American Journal of Science' for 1837, of the effects of an epi- demic among the shell-fish of the Ohio, which, killing the animals, their decomposed bodies rose to the surface of the water, leaving the shells in the bed of the stream, and floating away covered the banks of the river. Mr. Bensted points out that nearly the whole of the shells in the Kentish rag of his quarry appear to have been dead shells, and infers that their death might have been owing to a similar cause with that which destroyed the Uniones in America ; while their bodies intermingling with the drift wood on a sand-bank furnished the concretions described in this communication. The Rev. J. B. Reade submitted some of the substance of these bodies to an analysis by Mr. Rigg, who confirmed Dr. Mantell's suspicion of the presence of animal carbon in it, and states that the darker portion of the substance contains about 35 per cent, of its weight of carbon in an organized state. Dr. Mantell adds, that a microscopical examination with a low power detects innumerable portions of the periosteum and nacreous laminae of the shells of extreme thinness intermingled with the car- bonaceous matter, together with numerous siliceous spicula? of sponges, very minute spines of Echinodermata, and fragments of Polyparia, and remarks that these extraneous bodies probably became intermingled among the soft animal mass before the latter had un- dergone decomposition. He proposes to term the substance Mol- luskite, and states that it constitutes the dark spots and markings in the Sussex and Purbeck marbles. " On the Geological position of the Mastodon giganteum and as- sociated fossil, remains at Bigbone Lick, Kentucky, and other local- ities in the United States and Canada." By Charles Lvell, Esq., V.P.G.S.* M LXV. Intelligence and Miscellaneous Articles. ON THE PHOSPHORESCENCE OF THE GLOW-WORM. MATTEUCCI has performed numerous experiments on glow-worms, and has arrived at the following conclusions, * We have already given an abstract of this paper, see note, p. 518. 544 Intelligence and Miscellaneous Articles. some of which, he observes, are new in part, and others more accu- rately determined than heretofore : — 1. The phosphorescence of a glow-worm may cease hefore its death. 2. There exists in the glow-worm a substance which emits light, unaccompanied by sensible heat, and this does not require for its ex- hibition either the integrity or the life of the animal. 3. The phosphorescence of the insect ceases in carbonic acid and hydrogen gases in thirty or forty minutes, provided the gases are pure. 4. The light of the phosphorescent matter is decidedly brighter in oxygen gas than in atmospheric air, and it preserves its brilliancy for nearly three times as long. This occurs not only with the entire insect, but with the luminous segments separated from it. 5. The phosphorescent matter, when made to shine either in oxy- gen or in the air, consumes a portion of oxygen, which is replaced by an equal volume of carbonic acid gas. 6. The phosphorescent matter, when in contact with oxygen, but reduced to a state in which it cannot emit light, does not sensibly absorb oxygen, nor does it develope carbonic acid. 7. One proportion of oxygen and nine proportions of hydrogen or carbonic acid gas, form a mixture in which the phosphorescence continues for some hours ; it may therefore be concluded that it is on account of the alteration which happens to the phosphorescent sub- stance, that at the expiration of some days it ceases to shine, after ha- ving been put into pure oxygen, a portion of which is eventually re- placed by carbonic acid gas. The hydrogen in which several glow- worms were placed for twenty-four hours was analysed, the insects having shone for a few minutes only. The same happened if the gas was pure, in operating over mercury, carefully filling the receiver and reversing it two or three times to remove the air which adheres to the glow-worms. In this hydrogen it was found that its volume was slightly augmented ; with 8 cubic centimetres of hydrogen there was an increase of 0c,c-2 of volume which was absorbed by potash ; it was therefore carbonic acid which the insects had produced, and this oc- curred either because some oxygen remained in their tracheae, which combined with carbon and converted it into carbonic acid, or because the insects contained this acid ready formed. When the luminous segments were alone carefully put into hydrogen, they continued to shine for a few seconds only, and the gas suffered no change. 8. Heat, to a certain degree, increased the light of the phospho- rescent matter ; cooling produced the contrary effect. 9. When the heat is too strong the phosphorescent substance is altered, and the same occurs whether it be left in the air or in some gas for a certain time, provided it be separated from the animal. 10. This phosphorescent matter thus altered is not capable of emitting light or of becoming luminous ; these facts evidently deter- mine the nature of the phaenomenon ; the production of light in this insect is entirely dependent upon the combination of oxygen with the carbon, which is one of the elements of the phosphorescent matter. — Ann. de Ch. et de Phys. S 3. ix. 71. Intelligence and Miscellaneous Articles. 54:5 ACTION OF POTASSIUM AND SODIUM ON SULPHUROUS ACID. BY MM. FORDOS AND GELIS. When potassium or sodium is thrown into an aqueous solution of sulphurous acid, they act upon it in the same way as on pure water ; potash and soda are formed and hydrogen is evolved, which inflames ; the alkalies combining with the sulphurous acid to form sulphites, which remain in solution ; if the experiment be made in a tube with the pure metals, the phaenomena are similar, hydrogen and sulphites being obtained. The reaction takes place with so much violence, and the rise of temperature is so considerable, that it is natural to suppose that these two circumstances influence the results, and that if the reaction were less vivid different results would be obtained ; for such bodies as combine at common temperatures do not act upon each other when the temperature is raised. MM. Fordos and Gelis endeavoured therefore to bring potassium into contact with aqueous sulphurous acid, under such circumstances as should not raise the temperature, and they succeeded in the at- tempt, by operating with freezing mixtures and treating sulphurous acid with potassium which had been previously combined with metals that were incapable of decomposing water or sulphurous acid by themselves ; or in other words, they used the alloy of potassium and antimony, and that of potassium and mercury. These alloys decompose water which has been well cooled, regu- larly and without inflammation ; when they are treated with very dilute sulphuric acid containing sulphurous acid, hydrogen mixed with sulphuretted hydrogen is disengaged, the presence of which is ascertained by the smell and its action upon acetate of lead. If these alloys be treated with water containing sulphurous acid only, hydrogen is still disengaged, for the action cannot be so regu- lated as to obtain the perfect reduction of the sulphurous acid ; but no sulphuretted hydrogen is evolved, and acids precipitate sulphur in abundance from the solution ; consequently there are formed, under these circumstances, both a sulphite and a hyposulphite. — Journ. de Ph. et de Ch., Octobre 1843. ACTION OF ZINC ON SULPHUROUS ACID, SULPHITE OF ZINC. BY MM. FORDOS AND GELIS. An aqueous solution of sulphurous acid readily attacks zinc, espe- cially when the metal is in filings and the solution is concentrated ; there is increase of temperature but no gaseous product. Fourcroy and Vauquelin have stated, that when the action is rapid a notable quantity of hydrosulphuric acid gas is evolved ; but it is easy to prove that when this occurs it is from a totally different cause from that which they assign to it. Well- washed and recently prepared sul- phurous acid never produces this effect ; it occurs, on the contrary, when the acid employed contains sulphuric acid. In order to obtain a concentrated solution of zinc in sulphurous Phil, Mag. S. 3. No. 155. Suppl. Vol. 23. 2 N 546 Intelligence and Miscellaneous Articles. acid, the gas, well- washed, should be passed through Woulf s bottles, containing distilled water and cuttings of zinc. In this operation the following appearances occur : the metal at first tarnishes and is co- vered with a grayish crust ; the liquor then becomes slightly yellow, but not turbid ; the colour increases until it becomes as deep as that of a concentrated solution of chromate of potash, and it continues as long as there is great excess of sulphurous acid in the liquid. If the disengagement of gas slackens, or if by the increase of temperature the metal is more rapidly dissolved, the colour diminishes, and in the first case the liquid becomes turbid and a white pulverulent de- posit is formed ; if the operation be now stopped, or if the liquor be suffered to remain at rest during a night, this white powder is con- verted into white brilliant prismatic crystals, which collect on the sides of the vessel and on the undissolved portions of the metal. Examination of these Crystals. — They are easily obtained in con- siderable quantity, either by spontaneous evaporation or cautious evaporation in a water-bath ; much sulphurous acid is evolved, and the surface of the solution is covered with a thick layer of crystals. These crystals may be washed with water, for they are almost in- soluble in it ; but water containing sulphurous acid dissolves them readily, without becoming coloured ; these crystals are colourless, inodorous, transparent and insoluble in alcohol ; acids decompose them with the evolution of sulphurous acid, without any deposit of sulphur ; the solution in hydrochloric acid gives no precipitate with chloride of barium. When the crystals are moist they are readily converted into sulphate by exposure to the air, but when dry they may be long kept without alteration. The preceding facts prove that these crystals consist of sulphurous acid, oxide of zinc and water ; to analyse them the oxide of zinc was obtained by calcination, the sulphurous acid by converting into sul- phuric by means of iodine, and noting the quantity absorbed, and the water by calculation ; this it would be almost impossible to ob- tain directly, for the sulphurous acid is disengaged at about the same temperature. The salt appeared to be composed of One equivalent of sulphurous acid .... 32 One equivalent of oxide of zinc 40 Two equivalents of water 18 Equivalent .... 90 Examination of the Mother-water. — The solution from which the sulphite of zinc has been separated is colourless, transparent and in- odorous, contains no sulphuric acid ; and the examination proved that when sulphurous acid acts upon zinc two salts only are formed, the sulphite and hyposulphite ; when, however, the mother- water is further evaporated, it yields different products according to the tem- perature at which it is effected, yielding sulphurous acid, sulphite of zinc and other products. — Journ. de Ph. et de Ch., Octobre 1843. 5*7 INDEX TO VOL. XXIII. AdDS :—dammaric, 83; ferric, 217; nitric, 231 ; malic, 327. Miher, on the preparation of, 386. ./Ethogen and iEthonides, observations on, 71. Airy (G. B.) on the laws of individual tides at Southampton and at Ipswich, 49. Animal body, on the formation of fat in the, 19. Animal tissues, on the development of, from cells, 379. Animals, on the structure of the spleen in, 370. Amber, on the products of the decompo- sition of, 477. Armstrong (W. G.) on hydro-electricity, 195. Astringent substances, examination of some, 331. Babbage (Mr.), on the analytical engine of, 235. Balmain (W. H.) on aethogen and the aethonides, 71. Bark of the larch, chemical examination of the, 336. Barometer, indications of, during stormy weather, 446. Barreswil (M.) on the action of nitric acid on carbonate of lime, 78 ; on the oxidizing action of chlorate of potash on neutral substances, 318. Barry (Dr.) on the blood-corpuscles, 375. Beetz (W.) on the spontaneous change of fats, 505. Belam (J.), observations on the comet of 1843, 148. Bernoulli (M.), on an expression for the numbers of, 360. Birds, on fossil foot-prints of, 515. Blood-corpuscles,observationsonthe,375. Books, notices respecting some new, 452. Bouchardat (M.) on the octahedral crystal- lization of iodide of potassium, 317. Bread and flour of different countries, on the nutritive values of, 321. Brodie (P. B.) on the discovery of insects in the Wealden of the vale of Ayles- bury, 512, 527. Bronwin (B.) on the problem of three bodies, 8, 89. Brown ( W.) on the storms of tropical latitudes, 206, 276. Bruce (W.) on indications of the barome- ter and thermometer in stormy wea- ther, 446. Calculi, on the decomposition and disin- tegration of phosphatic vesical, 47. Caldecott (J.) on the great comet of 1843, 313. Calorific effects of magneto-electricity, observations on the, 263, 347, 435. Calorotypes,observationson the so-called, 356. Cambium, observations on, 54. Capocci (M.) on the comet of 1843, 311. Carbonic acid, exhalation of, from the human body, 72 ; decomposition of, by the light of the sun, 161. Cayley (M.) on some new formulae, 89. Cells, on the development of animal tis- sues from, 379. Cerium, observations on, 241. Chalk, on pipes or sandgalls in, 521. Chemical Society, proceedings of the, 71, 385. Chemistry : — colouring matter of the Per- sian berries, 3 ; sugar of the Eucalyp- tus, 14 ; extraction of palladium, 16 ; formation of fat in the animal body, 19; decomposition and disintegration of phosphatic vesical calculi, 47 ; reduc- tion of metals from solutions of their salts by the voltaic circuit, 51 ; on aethogen and aethonides, 7 1 ; exhalation of carbonic acid from the human body, 72; spontaneous decompositionof chlo- rate of ammonia, 75 ; analyses of cymo- phane, 77 ; action of nitric acid on car- bonate of lime, 78 ; on the Cowdie pine resin, 81 ; compound nature of nitrogen, 135 ; on a peculiar molecular change in a metallic alloy, 141 ; olivile, 156 ; new combinations of cyanogen, 157 ; decomposition of carbonic acid by the light of the sun, 161 ; new process for preparing cyanogen, 1 79 ; existence of acompound radical incertain sulphates, 203; on ferric acid, 217; on nitric acid, 231 ; action of chlorides on the protochloride of mercury, 233 ; on lanthanium,didymium, cerium, erbium, 2 N2 .548 INDEX. terbium and yttria, 241 ; on changes in the composition of milk, 281 ; non- precipitation of lead from sulphuric acid, 314 ; octahedral crystallization of iodide of potassium, 317; presence of tin in sulphuric acid of commerce, 317 ; oxidizing action of chlorate of potash, 318; on panary fermentation, 321 ; pre- paration of malic acid from the garden rhubarb, 327 ; on astringent substances, 331 ; on the changes in colour exhi- bited by solutions of chloride of copper, 367 ; preparation of aether, 386 ; action of sulphurous acid on metallic oxides, 397, 545 ; production of iodoform, 398 ; preparation and constitution of theine, 426 ; products of the decomposition of amber, 477 ; sub-salts of copper, 496 ; spontaneous change of fats, 505. Chlorate of ammonia, spontaneous de- composition of, 75 ; of potash, on the oxidizing action of, 318. Chloride of copper, on the changes in colour exhibited by solutions of, 367. Chrysene, composition of, 479. Chrysorhamnine, composition of, 4. Clegg's (Mr.), differential dry gas light meter, account of, 388. Close (M.) on the great comet of 1843, 147. Coal-fields of North America, observa- tions on the, 181. Cock (W. J.) on palladium, 16. Colouring matter of the Persian berries, on the, 3. Comet of 1843, observations respecting the, 147, 148, 149, 151,152, 311,472. Cooper (J. H.) on fossil bones found in Georgia, 189. Cooper (J. T.) on improvements in the instrument for ascertaining the re- fracting indices of bodies, 509 . Copper, on the constitution of the sub- salts of, 496. Cowdie pine resin, examination of the, 81. Cowper (H. A.) on the comet of 1843, 150. Crustacea, on the organ of hearing in, 383. Curves, on the application of a new me- thod to the geometry of, 338. Cyanogen, on some new combinations of, 157 ; on a new process for preparing, 179. Cymophane, analyses of, 77. Daguerreotype, observations on, 1 75. Dammaran, composition of, 85. Dammaric acid, composition of, 83. Dammarol, composition of, 86. Dammarone, composition of, 87. Damour ^M. A.) on new analyses of the cymophane of Haddam, 77. Daniell (Prof.) on the existence of a compound radical in certain sulphates 203. Didymium, observations on, 241. Drach (S. M.) on the diurnal tempera- ture of the earth's surface, 49 ; on the places of Saturn computed by Hansen's formula, 299. Draper (W.) on the decomposition of carbonic acid gas and the alkaline car- bonates by the light of the sun ; and on the tithonotype, 161, 356; on a change produced by exposure to the beams of the sun in the properties of an elementary substance, 388 ; descrip- tion of the tithonometer, 401. Dupasquier (M.) on the non-precipita- tion of lead from solution in sulphuric acid, 314 ; on the presence of the sul- phate of tin in the sulphuric acid of commerce, 317. Earth, on the diurnal temperature of the surface of the, 49. Ebelman (M.) on the composition of pechblende, 475 ; on the composition of wolfram, 477. Electric and nervous influences, on the analogy between the phaenomena of, 41. Electric currents in Pennance Mine, ex- periments on the, 457, 491. Electricity, on a method of etching on hardened steel plates by, 106. , on the relations which connect light with, 254. of steam, observations on the, 194. Electrified bodies, on the cooling of, 260. Ellipse, method of proving the three leading properties of the, 48. Entozoon folliculorum, on the structure and development of, 368. Equations, numerical, new criteria for the imaginary roots of, 450. Erbium, observations on, 251. Evans (W. J.) on the structure of the spleen in man and other animals, 370. Everest (R.) on the high temperature of wells near Delhi, 302. Everitt (T.) on garden rhubarb as a source of malic acid, 327. Eucalyptus, on the sugar of the, 14. Farre (A.) on the organ of hearing in Crustacea, 383. Fat, formation of, in the animal body, 19; on the spontaneous change of, 505. Fitzgerald (Capt.) on the accident by lightning to Government-house, Cal- cutta, 177. Flour of different countries, on the nu- tritive values of, 321. Fordos (M.) on the action of potassium, sodium, and zinconsulphurousacid,545. INDEX. 549 Forster (Dr.) on the comet of 1843, 150. Fourier, demonstration of the rule of, 6. Fownes (G.), notes on the preparation of aether, 386. Fox (R. W.), notice of some experiments on the electric currents in Pennance mine, near Falmouth, 457, 491. Fruits, fossil, descriptions of some, 541. Galhraith (W.) on the recomputation of Roy's triangulation for connecting the observatories of Greenwich and Paris, 147. Gases, on the detithonizing power of cer- tain, 176. Gay-Lussac (M.) on nitric acid, 231. Geiis (M.) on the action of potassium, sodium, and zinc on sulphurous acid, 545. Geological Society, proceedings of the, 57, 300, 457, 512. Geology : — variegated appearances of the new and old red sandstone systems, 1 ; on the latest geological changes in the south of Scotland, 28 ; geology of Rus- sia, 57 ; geological structure of the Ural mountains, 124; geology and palaeontology of North America, 180 ; superficial deposits near Manchester, 300 ; occurrence of the Bristol hone- bed, 301 ; tertiary formations of the United States, 304 ; packing of ice in the river St. Lawrence, 459 ; structure and history of mastodontoid animals, 464 ; geology of the island of Rhodes, 465 ; structure of the tusks of masto- dontoid animals, 468 ; on fossil insects in the Wealden, 512, 529 ; fossils from southern India, 514 ; fossil foot-prints of birds, 515 ; on the Ochil hills, 518 ; structure of the Delta of the Ganges, 519 ; on pipes or saudgalls in chalk, 521 ; on some concretions in tertiary beds of the Isle of Man, 522 ; on the Bala limestone, 524 ; lias bone-bed of Gloucestershire, 531 ; Silurian rocks of Westmoreland and Lancashire, 533 ; stratified rocks of Berwickshire, 539 ; fossil fruits from the chalk, 541. Glow-worm, on the phosphorescence of the, 543. Grant (Dr.) on mastodontoid animals, 465. Gravity, on the variation of, in ships' car- goes, 154. Grove (Prof.) on the gas voltaic battery, 376 ; on voltaic reaction, 443. Grover (Capt. J.), notice of the comet,369. Hamilton (Sir W. R.) on an expression for the numbers of Bernoulli, and on some connected processes of summa- tion and integration, 360. Hare (R.) on Redfield's theory of storms, 92, 481 ; on the existence of a compound radical in certain sulphates, 203. Heat, on the mechanical value of, 263, 347, 435 ; on the production of, by the contraction of elastic tissue, 326. Hennell (H.), notice of the late, 74. Herschel (J. F. W.), notice of an extraor- dinary luminous appearance seen in the heavens on the 17th of March, 1843, 54. Hoskins (S. E.) on the decomposition and disintegration of phosphatic vesi- cal calculi, 48. Hunt (R.) on the spectral images of M. Moser, 225, 356, 415. Hydro-electric machine, on some experi- ments performed with the, 194. Hyperbola, method of proving the three leading properties of the, 48. Ichthyolites, on some new, 186. Ick (Mr.) on some superficial deposits near Birmingham, 300. Iodide of potassium, octahedral crystalli- zation of, 317. Iodoform, on the production of, 398. Images, spectral, observations on, 225, 356,415. Indigo-tithonic rays, on an instrument for measuring the chemical force of, 401. Inglis (H.), notice of the late, 74. Insects, fossil, on some, 512, 529. Iron, on the composition of an acid oxide of, 217. J. J. on the variation of gravity in ships' cargoes, 154. Jacob (R. E.) on the comet of 1843, 149. James (Capt.) on the variegated appear- ances of the new and old red sandstone systems, 1. Johnston (J. F. W.) on the sugar of the Eucalyptus, 14. Jones(J. W.)on the blood-corpuscles, 375. Joule (Mr.) on the calorific effects of mag- neto-electricity, and on the mechanical value of heat, 265, 347, 435. Kane (R.) on the colouring matters of the Persian berries, 3. Kaye (C.) on a collection of fossils from southern India, 514. Kemp (A.) on a new process for preparing cyanogen, 179. Kemp(W.)on the latest geological changes in the south of Scotland, 28. Kendall (Prof.) on the comet of 1843, 148, 472. Keyserling(Count)onthe geological struc- ture of the Ural mountains, 124. Knox (G. J.) on the compound nature of nitrogen, 135. Lanthanium, observations on, 241. Larveque (A.) on the action of chlorides on protochloride of mercury, 233. 550 INDEX. Lead, occurrence of, in sulphuric acid, 314. Lemniscates and other curves, on the rec- tification of, 138. Liehig (J.) on the formation of fat in the animal body, 19. Light, on the relations which connect electricity and heat with, 254. , invisible, observations on, 225, 356. Lightning conductors, on the use of, in India, 177. Lime, action of nitric acid on the carbo- nate of, 78. Logan (M.) on the St. Lawrence, and on the modern deposits of its valley, 459. Luminous appearance seen on the i/th of March 1843, on a, 54. Lyell (C.) on the ridges, elevated beaches &c. of the Canadian lakes and valley of the St. Lawrence, 183 ; on the geo- logical position of the Mastodon gi- ganteum, 190 ; on the tertiary forma- tions of the United States, 305 ; on the fossil foot-prints of birds, &c. in the valley of Connecticut, 515. Lymphatic vessels, on the import and office of the, 52. MacCullagh (Prof.) on the solution of the problem of total reflexion for ordinary media and for uniaxal crystals, 137. Magnetism, terrestrial, contributions to, 377, 380. Magneto-electricity,on the calorific effects of, 263, 347, 435. Malic acid, on the preparation of, from the garden rhubarb, 327. Mallet (R.) on the occurrence of a me- tallic alloy in an unusual state, 141. Mantell (Dr.) on American fossils, 186 ; on fossil fruits from the chalk forma- tion, 541. Mastodon giganteum, on the geological position of the, 190. Mastodontoid animals, on the structure and history of, 464 ; on the structure of the tusks of, 468. Matteucci (M.) on the phosphorescence of the glow-worm, 543. Meillet (A.) on some new combinations of cyanogen, 157. Menabrea (M.) on Mr. Babbage's analy- tical engine, 235. Mercury, action of chlorides on the pro- tochloride of, 233. Metallic alloys, observations on some, 141. Metallic oxides, action of sulphurous acid on, 397. Metals, reduction of, from solutions of their salts by the voltaic circuit, 51 ; on some new, 241. Meteorological observations, 79, 159, 239, 319, 399, 479. Milk, on the changes in composition of, 281. Millon (M.) on nitric acid, 231. Mollusca, on the fossilized remains of the soft parts of, 542. Montojo (M.) on the comet of 1S43, 149. Mosander (Prof.) on cerium, lanthanium and didymium, 241 ; on yttria, ter- bium, and erbium, 251. Moser (Prof. L.) on the so-called caloro- types, 356 ; experiments and observa- tions on the discoveries of, 225, 415. Murchison (R. I.) on the geology of Russia, 57 ; on the geological structure of the Ural mountains, 124. Myriapoda, on the structure and develop- ment of the nervous and circulatory systems in, 371. Nasmyth (Alex.) on the minute structure of the tusks of extinct mastodontoid animals, 468. Nerves, on the origin of, 384. Newport (G.) on the development and circulatory system of the Myriapoda, 371. Nitric acid, observations on, 231. Nitrogen, on the compound nature of, 135. Nitro-theine, composition of, 434. Noad's (H. M.) lectures on chemistry, re- viewed, 45. Observatories of Greenwich and Paris, recomputation of Roy's triangulation for connecting the, 147. Olivile, observations on, 156. Ornithoidicnites, on some specimens of, 186. Owen (D. D.) on the geology and palaeon- tology of North America, 180 ; on the geology of the western states of North America, 518. Palaeontology of North America, on the, 180. Palladium, extraction and alloys of, 16, 398. Panary fermentation, observations on, 321. Pechblende, on the composition of, 475. Pelletier (M.) on the products of the de- composition of amber by heat, 477. Pepys (W. H.) on the respiration of the leaves of plants, 378. Persian berries, on the colouring matter of the, 3. Phosphorescence of the glow-worm, ob- servations on the, 543. Pierce (B.) on the comet of 1843, 152. Plants, on the descending fluids of, 54 ; on the respiration of the leaves of, 378. Playfair (L.) on the changes in the com- position of the milk of the cow, 281. Pollock (R.) on the comet of 1843, 150. INDEX. 551 Pollock's (Sir F.) method of proving the three leading properties of the ellipse and the hyperbola from a well-known property of the circle, 48. Polygonum bistortum, chemical examina- tion of, 335. Prater (Mr.) on Moser's discovery, 227. Pring (J. H.) on a method of etching on hardened steel plates and other polished metallic Surfaces by means of electri- city, 106. Problem of three bodies, observations on the, 8. Rainey (G.), observations on the descend- ing fluids of plants, 54. Redfield (W. C.) on whirlwind storms, 92 ; on the palaeontology of North America, 180. Refracting indices of bodies, on an in- strument for ascertaining the, 509. Resins, examination of some new, 81. Rigg (R.) on the compound nature of carbon and nitrogen, 383. Roberts (M. J.) on the analogy between the phaenomena of the electric and ner- vous influences, 41. Roberts (W.) on the rectification of lem- niscates and other curves, 138 ; on a class of spherical curves, 140. Royal Astronomical Society, proceedings of the, 145,311,472. Royal Irish Academy, proceedings of the, 135. Royal Society, proceedings of the, 47, 368. Russia, geological survey of, 57. Sabine (E.), contributions to terrestrial magnetism, 377, 380. Sandstone systems, on the variegated ap- pearances of the new and old red, 1. Saturn, places of, computed by Hansen's formula, 298. Scharling (E. A.) on the exhalation of carbonic acid from the human body, 72. Scotland, on the latest geological changes in the south of, 28. Selenium, observations on, 141. Sharpe (D.) on the Bala limestone, 525 ; on the Silurian rocks of the South of Westmoreland and North of Lancashire, 533. Shaughnessy (W. B.) on the use of light- ning-conductors in India, 177. Simms (W.) on a self-acting circular di- viding engine, 145. Skin, on the special function of the, 50. Smee (A.) on the cause of the reduction of metals from solutions of their salts by the voltaic circuit, 51. Smith (B. R.) on the structure of the Delta of the Ganges, 519. Smith (J. D.) on the composition of an acid oxide of iron, 217 ; on the consti- tution of the subsalts of copper, 496. Sobrero (A.) on olivile, 156. Solly (E.) on the colour of solutions of chloride of copper, 367. Spleen, on the structure of the, 370. Spratt (T. A. B.) on the geology of the island of Rhodes, 465. Stark (Dr.) on the supposed development of animal tissues from cells, 379. Steam, on the electricity of, 194. Stenhouse (Dr.) on some astringent sub- stances, 331 ; on theine and its prepa- ration, 426. Stevenson (W.) on the stratified rocks of Berwickshire, 539. Storms, on the theory of, 92, 481 ; of tropical latitudes, on the, 206, 276. Strickland (H. E.) on the occurrence of the Bristol bone-bed, 301 ; on some remarkable concretions in the tertiary beds of the Isle of Man, 522 ; on im- pressions in the lias bone-bed in Glou- cestershire, 531. Stubbs (J. W.) on the application of a new method to the geometry of curves, and curve surfaces, 338. Succisterene, composition of, 479. Sugar of the Eucalyptus, composition of the, 14. Sulphates, on the existence of a com- pound radical in certain, 203. Sulphuric acid, on the non-precipitation of lead from, 314 ; existence of tin in, 317. Sulphurous acid, action of potassium and sodium on, 545 ; action of zinc on, ib. Sun, decomposition of carbonic acid gas by the light of the, 161. Swan (J.) on the origin of the nerves, the cerebellum, and the striated bodies, 384. Tate (W.) on factorial expressions and the summation of algebraic series, 369. Tea, chemical examination of, 321, 426. Terbium, observations on, 251. Theine, on the preparation and constitu- tion of, 426. Thermography, observations on, 415. Thermometer, indications of, during stormy weather, 446. Thomson (R. D.) on the examination of the Cowdie pine resin, 81 ; on the re- sults of the panary fermentation and on the nutritive values of the bread of different countries, 321. Tin, presence of, in sulphuric acid, 317. Tithonometer, description of the, 401. Tithonotype, observations on the, 161. Trimmer (J.) on pipes or sandgalls in chalk, 521. 552 INDEX. Ural mountains, on the geological struc- ture of the, 124. Vapours, on the detithonizing power of certain, 176. Veall (Mr.) on a halo round the sun, 316. Verneuil (M. de) on the geological struc- ture of the Ural mountains, 124. Vignoles (Prof.) on Clegg's differential dry gas light meter, 388. Vogel (M.) on the action of sulphurous acid on metallic oxide, 397. Voltaic battery, observations on a new, 376. Voltaic circuit, on the cause of the reduc- tion of metals by the, 51 ; on some new instruments and processes for deter- mining the constants of a, 381. Voltaic reaction, experiments on, 443. Walker (S. C.) on the comet of 1843, 148. Walter (M.) on the products of decompo- sition of amber, 477. Wartmann (Prof.) on the relations which connect light with electricity, 253 ; on some experiments to show that electri- city does not contain heat, 257. Wartmann (Prof.) on the cooling of elec- trified bodies, 260. Wheatstone (Prof.) on some new voltaic instruments, 381. Willis (R.) on the special function of the skin, 50 ; on the import and office of the lymphatic vessels, 52. Wilson (E.) on the Entozoon folliculorum, 368. Winn (Dr.) on the production of heat by the contraction of elastic tissue, 326. Wolfram, on the composition of, 477. Wonfor (J.) on the spontaneous decom- position of the chlorate of ammonia, 75. Xanthorhamnine, composition of, 5. Young (Prof. J. B.) on the demonstra- tion of the rule of Fourier, 6 ; on new criteria for the imaginary roots of nu- merical equations, 450. Yttria, observations on, 251. Zoology, propositions for rendering the nomenclature of, uniform and perma- nent, 108. END OF THE TWENTY-THIRD VOLUME. PRINTED BY BED LION E. TAYLOR, STREET. FUMMAM. w /J) ■ ^ p> "*S. -f^-^^m^: I ■^ik. KXk? S'^fC '