$£&. I JOURNAL OF CHEMISTRY, AND THE ARTS, VOL. XIL 3iliustrate5 foitf) (JEngm&ingg* BY WILLIAM NICHOLSON. LONDON: PRINTED BY W. STRATFORD, CROWN COURT, TEMPLE EAR ; FOR THE AUTHOR, AND SOLD BY HIM AT*NO, 10, SOHO-SdUAREJ AND BY H. D. SYMONDS, PATERNOSTER-ROW. 1805 PREFACE. X HE Authors of Original Papers in the present Volume, are, Davies Giddy, Esq. M. P.; Mr. O. Gregory; Mr. Wil- liam Close ; Mr. John Dalton; W. N. ; Mr. Charles Young ; Mr. J. Stodart £ Count Rumford, V. P R. S. ; Mr. G. I. Singer; J. P.; T. S. Traill, M. D. i G. Cumberland, Esq.; Mr. S. Clegg ; Mr. Dalton ; T. I. B. • T. Plowman, Esq.; R A. j N. D. Starck, R. N. £ John Gough, Esq. • A Cor- respondent ; An Enquirer ; Mr. Arthur Woolf ; Mr. Elizur Wright; Thomas Northmore, Esq.; Dr. Beddoes; Mr. Bancks. Of Foreign Works, Professor Proust ; J. H. Hassenfratz; G. A. Lampadius; Mr. Prony ; Beaunier; Gallois; J. B. Richter; Mr. Ritter; Citizen Bernoulli; Vauquelin; C. A. Prieur ; Guyton ; Morveau ; Chaptal ; Dr. Valli ; M. Vau- cher; M. Hauffman ; Biot; Thenard ; Descotils; C. L. Cadet; Professor Pfaff; Tromsdorf; M. Achard; M. Stein- acher; M. Giobert; Humboldt; M. Lagoux de Flaix; M. Dodun. And of English Memoirs abridged or extracted, Hum- phrey Davy, Esq. F. R. S. ; Mr. Rose ; Benj. Smith Barton, M.D.; Mr. John Hecke welder; J.C. Curwen,Esq.M.P.; Mr. William Bartram; Thomas Andrew Knight, Esq. ; Rev. D. Pape; William Herschel, L. L. D, F. R. S. ; Charles Flatchett, Esq. F. R. S. ; T. C. Hope, M. D, F. R. S. Ed. Of PREFACE. Of the Engravings, the Subjects are, 1. Apparatus for raising Water, by Mr. Close. 2 . Furnace for bending Wood . 3, 4. Blowing Engine by the Fall of Water at Poullaouen. 5, 6. Apparatus for analysing Vegetable Soils, by H. Davy, Esq. 7, Diagrams to explain the Doctrine of Heat, by Count Rumford, V. P. R. S. 8. Magnified Representation of Insects found on Corn, by G. Cumberland, Esq. 9. An improved Steam Engine, by Mr. Clegg. 10. Simple Register Thermometers. 11. The Framing employed to raise the Roof of Clapham Church. 12. An improved Sheep Fold, by T. Plowman, Esq. 1§. Applicative Compass, by Capt. Starck, R. N. 14. Section of a Drain, by J. C. Curwen, Esq. 15. Diagrams to illustrate a Series of Propositions re specting a Division of the Circle, by Mr. John Gough. 16. Schemes exhibiting the Positions of the new Planet Juno, by Dr. Herschel. 17. Mr. Pape's Improvement of Rye Har- bour. 18. A new Air Pump, by Mr. Wright of America. 19. New Valve and Parts of a condensing Syringe for the Gases, by Mr. Cuthbertson, with which Mr. Northmore's Experiments were made. 20. A very simple and improved Graphometer, by Mr. Bancks. Soho Square, London, January 1, IS 0(5, TABLE OF CONTENTS TO THIS TWELFTH VOLUME. E: SEPTEMBER, 1805. NGRAVINGS of the following Objects: 1 . New Apparatus for raifij>g Water above its Level by the Syphon., by Mr. Clofe j 2. Furnace for bending Wood j 3, 4. Two Plates of the Machine for producing a Blait by a Shower* of Water palling down a perpendicular Pipe. I. Letter from Davies Giddy, Efq. M. P. defcribing a lingular Fact of the invi- fibleEmiffion of Steam and Smoke together from the Chimney of a Furnace; though either of them, if feparately emitted, is vifible as ufual. Page 1 II. On a Meteoric Stone that fell in the Neighbourhood of Sigena, in Arragon, in 1773, by Profeflbr Proud. - - - . - 2 III. Farther Remarks on Mechanic Power, in Reply to Mr. J. C. Horn- blower. In a Letter from Mr. O. Gregory, Royal Mil. Academy. 7 IV. Defcription" and Effects of an Apparatus for rain ng Water by Means of. Air condenfed in its Defcent through an inverted "Syphon^ By Mr. William Clofe. From the Inventor. - - - - 1Q V. Remarks on Count Rumford's Experiments relating to the Maximum Den- fity of Water. In a Letter from Mr. John Dal ton. - - !>S VI. On the Art of bending Wood. By J. H. HafTenfratz. - - 30 VII. Experiments made in the great, in a reverberating Furnace on Caft Iron, confirming the eftablhried Theory reflecting the Difference between caft and malleable Iron. By G. A Lampadius, Prof, of Chemiitry and Metallurgy at Freyberg. - - - - - - - 34 VIII. Remarks on the burfting of two Mufquet Barrels by a Charge of Gun- powder confined by Sand. W.N. v - - - 40 IX. Report of a Method of meafuring the initial Velocity of Projectiles dif- charged from Fire-arms, both horizontally and with different Elevations, made to the Phyfical and Mathematical Clafs of the National Inftitute by Mr. Prony, Dec. 11, 1803. Abridged from the Original. - - 41 X. Fact, concerning the invifible Emiffion of Steam into the Air. W.N. 47 XI. Experiments made with the Water blowing Machines of the Iron Works of Poullaouen ; by Citizens Beaunier and Gallois, Mine-Engineers. - 48 XII. A Method of rendering the long and fhort Vibrations of a Balance, governed by a fpiral Spring, precii'ely equal in Duration. By Mr. Charles Young. In a Letter from. the Inventor. - • >- - 56 Scientific News, 58. — Compofition of Muriatic Acid, ib. — Literary and Philo- 'fophical Society of Newcaftle upon Tyne, 60. — New Procefs for fteeping Hemp, 61. — Medical Theatre, St. Bartholomew's Hofpital, ib. — Medical Inftitution, 62. — Properties of blued Steel not generally known, 63.— Pre- servation of fucculent Plants, 64. k OCTOBER ii CONTENTS. OCTOBER 1S05. Engravings of .the following Objecls : 1, 2. Apparatus for Analyfing Vege- table Soils* by H. Davy, Efq. Profeffor of Chemiftry at the Royal Inftitu- tion ; 3. Diagrams to explain the Do6irine of Heat, communicated by Count Rumford. I. Experimental Investigations concerning Heat. By Benjamin Count of Rum- ford, V. P. R. S. Foreign Affociate of the National Inftitute of France, &c. &c. Received from the Author. - - - Page 65 II. On pure Nickel, difcovered to be one of the noble Metals, and on its Preparation and Properties. By J. B. Richter. - - ' - 75 III. On the Analyfis of Soils, as connected with their Improvement. Bv Humphrey Davy, El'q. F. R. S. Profeffor of Chemiftry to the Board of Agriculture and to the Royal Inftitution. - - - 81 IV. Difcovery of a new Vegetable Subftance, by Mi\ Rofe. - 91 V. New Galvanic Difcoveries by Mr. Ritter, extracted from a Letter from Mr. Chrift. Bernoulli. - - - - - adopt ; in order that the very extenfive communications with which the Journal has been honored, might not prevent him from giving all the foreign difcoveries and fuch other general intelligence as the nature of the plan demands. It will cajily be feeii that the, additional copy will by this 'means amount to one half more than the former quantity ; and it is unnecefjary to point out the great advantages which muft refult from fuch an addition. The Editor takes this occajion to repeat his acknowledgments for the encou- ragement which has been given to his exertions, particularly within the lafi twelve months, in which the [ale has nearly doubled,* The quantity of original matter continues to increafer and amounts to more than half of the whole work. Great part vf the remainder confifts in foreign articles never before publijhed in this country, together with fame extracts and abridgments from our beft academical tranfaclions. The whole publication may therefore be conjidered as original, jince it is never made up by extracts from the periodical works of this country, which, on the contrary, very frequently copy from its contents. * It has been necefTary to reprint a confiderable part of the former volumes in order to make complete fets, which may now be bad, or any {ingle numbers or volumes, from the commencement* .-„ ■ ,„,,.,,.. „ U' , Ml M... , ill > ... ■ ■■ ... JOURNAL OP NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. SEPTEMBER, 1805. ARTICLE I. Letter from Davies Giddy, Efcj. M. P. defcribing a fingular FdSt of the invifible Emijfwn of Steam and Smoke together from the Chimney of a Furnace ; though either of them, if feparatelj/ emitted, is vifible as ufuaL To Mr. NICHOLSON. SIR, CUfton, Augujle, 1805. A RAVELLING, and a variety of occupations, have hi- Peculiar fa&s therto prevented me from fending you an account of the cir- , ved in « 1 ° J working one of cumftances obferved by myfelf and others, during the work-Trevith'ck's ing of an engine on Mr. Trevithick/s conftru6tion, at Merthynfteana ^"es. Tidwell in South Wales, and which I had the pleafure of relating to you, fome time fince, in Soho Square. I now tranfmit a it ulement of the fads, avoiding all comments or attempts at explanation. Mr. Trevithick having adapted his fleam engine to and that only for a (hort time ; nor were drops or mift vifible any where. It was propofed, that the regifter When the (hould be flowly clofed ; and as this was done, a condenfation off the fteam or" ^eara manifefted itfelf at a fmall diftance from the chimney, was vifible, and and finally appeared in the fame quantity, as if it had pro- was fliut oft' the ceec*ed immediately from the boiler. The experiment was fmoke was vi- then reverfed. The fteam was gradually confined to the lc# boiler; when fmoke became more and more vifible, till it equalled in quantity and appearance that commonly produced by a fimilar fire: and thefe trials were alternated a great The draft up number of times, with unvarying fuccefs. Laftly, it became the chimney was r r .' . , ,, . , . ,,/» increafed by the a matter or Jpeculation, whether or in what degree the draft admiflion of the was affected by the admiflion of fteam into the flue. To afcertain this, every one prefent looked as attentively as poflible into the fire-place; while the engine moved at the rate of a few ftrokes in a minute; and all agreed in de- daring, that the fire brightened each time the fteam ob- tained admiflion into the chimney, as the engine made its ftroke. I am, Sir, Your very faithful humble fervant, DA VIES GIDDY. II. On a Meteoric Stone that fell in the Neighbourhood of Sigena, in Arragon, in 1773, by Profejfor Proust*. Stones have JL HE author begins his paper by fome previous hiftorical fallen from the facis. N0 one novv queftions, that ftones have fallen from. atmofphere ta> , , 1- . ..S1 ' , , , _, various ages, »ie atmofphere in different parts of the world. The ancients * Abridged from the Journal de Phyfique, for March 1805. mention ON METEORIC STONES. 3 mention it as having occurred at various times, and later ages have recorded the time and authenticated circumftances of feveral fuch incidents. In ourowndays, (tones or mineral bodies termed meteoric, have been collected in the Eaft Indies, America, Scotland, England, France, Italy, Hungary, and and in all parts laftly in Spain : and that nothing may be wanting in future to0 * convince thofe who refufe their aflfent to the united teftimony of all ages and all countries, nature appears to have purpofely ordered a repetition of this furprifing phenomenon: no longer ago than the 26th of April, 1803, a (bower of thefe (tones Shower of ftones covered a fpace of ground two miles long and above a mile ln l8o3» broad, near l'Aigle in Normandy. The French Inftitute im- mediately nominated a eommiffioner, to examine into the fact on the fpot, to take the depofitions of witneffes, compare them with the circumftances, and bring forae of the (tones to Paris. As the firft thing to be done with a new mineralogical fub- AnaJyfis of itance, is, to analyfe it, the Prefident of the Royal Society of J^f ^ ! London, and feveral other gentlemen who had fuch (tones in Howard, their collections, put them into the hands of Mr. Howard, a Member of the Society, that he might fubject them to chemical examination. He found to his great furprife, that all thefe who found them ftones, from the remoteft quarters of the globe, contained ^ flnlllar "* .1 r • • i i'/r • i • ,• i . their comyofi- the lame principles, differing only in proportion; and, what tion. was (till more ftriking, that they all contained iron combined with nickel, a compound to be met with among none of the minerals in any part of the globe with which we are acquainted, Vauquelin has (ince confirmed by repeated experiments, the accuracy of Mr. Howard's observations. All men of fcience They have have hence been led to conclude, that thefe ftones muft have therefore a a common origin; but whence they originate is the queftion. comminonSin> Do they belong to that earth on which they fall? are they but whence ? formed in the atmofphere itfelf? or have they been projected from lunar volcanoes ? On thefe points men's fentiments are divided ; and the arguments have been collected by Dr. Izarn, in his Lithologie Atmofpherique. One of thefe ftones has been in the royal collection at °n* Jn tne co** Madrid -ever fince 1773. This the minitter has allowed MaS" Mr. P. to analyfe, leaving the principal part of it ftill in the collection for the fatisfaction of the curious. The following letter was fent with it to Don Manuel de P^oda, Minifter of State, by the captain-general of SaragofTa, B2 *« In £ ON METEORIC STONLS, Aecount of its '< In November laft an extraordinary occurrence, faid to have happened on the Seventeenth of that Month in a ploughed field at Sena, a village in the diltrict of Sigena, was the fub* jecl of converfation in this city. " The iky being perfectly ferene, three reports refembling thofe of cannon were heard, and followed by the fall of a itone weighing nine pounds and one ounce, at a little diftance from two labouring men. One of them went up to it, but the ftrong fmell it emitted (topped him a moment. " Recovering from his furprife he went nearer, raifed it up with his fpade, and waited till it was fufficiently cold for him to carry it to the village, where he delivered it to the prieft. V From inquiries made immediately afterwards on the fpot, and among the people in the neighbourhood, it appears, that the noife in the air and fall of the ftone were not accompanied with any ftorm, or with lightning." ^Another meteo- , To bring into one view all that is yet known of ftones fall- ric lho^cart°fell ,nS m Spain, the author fubjoins a letter of the Bachelor at Roa in Spain, Cibdadreal, on thofe that fell in the village of Koa, near in 1438, Burgos, in 14-38. in the view of " While the King Don John and his court were hawking the King of near the village of Roa, the fun was concealed behind white P**"* .clouds, and bodies refembling gray and blackifh ftones were feen to fall from the air, of fuch bulk as tooccafion the greateft furprife. The ground was " After this phenomenon had continued for an hour the thcm!d *"n re"aPPearecl> and tne falconers immediately rode to the place, which was not above a mile diftant. They brought back information to the king, that the ground was fo com- pletely covered with ftones of all fizes as not to be vifible. " The king would have gone thither, but his courtiers prevented him, obferving, that a place chofen by Heaven for the theatre of its operations might not be free from danger, and that he had better fend fome of his attendants. Gomez Thefc ftones Bravo, the captain of his guards, undertook the office. He were very brought four of the ftones to Roa, whither the king had already retired. They were of confiderable fize : fome were round, and as large as a mortar, others like pillows and half -f unique wctremely light, meafu res (fuch as contain about 4olbs weight of corn,) but what was moft afloniihing, was their exceffive lightnefs, fince 4 the ©N METEORIC STONES. 5 the largeft did not weigh half a pound. They were of fuch and of a tender a tender texture, that they refembled the foam of the tea texture' condenfed more than any thing. You might ftrike on them with your hand without tear or bruife, or pain, or the ilighteft mark. The king has ordered fome to be Tent you, &c." It feems from this defcription, that thefe ftones rauft have been very different from thofe of the prefent day. The ftone of Sigena, when delivered to Mr. Proud, weighed The (tone of fix pounds ten ounces. With it was a piece of three or four SlSenadefcnbcd» ounces, the only one remaining of thole that had been broken from it by curious perfons. It was interfperfed with fpols of Interfprrfeawhfr run1, both externally and internally, owing probably to its ru y po k* having been immerfed in water to try the effect of that fluid on it. From thefe however, fome inftru&ive inferences may be drawn refpe&ing the native place of thefe ftones. Its fhape is an irregular oval, {'even or eight inches long, Its figure* four or five broad, and four in its greateft thicknefs. One fide is flattim, a little deprefjed in the middle, and very round on the edges; the other is an obtufe triedral pyramid with un- equal fides, greatly rounded at the fummit and on the edges*. It appears to have had the black vitreous cruft common to It had a vitreous ftones of this kind, though from its fragility the greater part has fallen off in pafling through many hands and receiving occafional blows, fo that none remains except in the hollow of the bafe, and a little on the faces of the pyramid. On examining this cruft it is eafy to fee, that it muft have This mufthave been the efTed of heat fubfequent to the formation of the ^een produced , n riii by violent mo- ftone, and unqueftionably very powerful though momentary ; mentary heat fince the metallic and fulphureous particles immediately fi^ceits forr/u- beneath the cruft had not time to change colour, or even Iofe their luftre. It has all the porofity of an aggregated mafs of fan dy it is porous, particles without any cement, fo that the breath will eafily pafs through a piece held between the teeth. It will not n°t very hard, ftrike fire with fteel, and the fame may be faid of the pyrites it contains. Its colour is a uniform bluifti gray, like that of a black fub- of a bluifli gray. ftance enlightened by a white : it is the hue of an earthy com- pound tinged by iron oxideii at a minimum* * Does this defcription agree with what is faid above, that feveral pieces have been broken from it ? Apparently above a quarter of the ftone, on comparing its original and prefent weight. J. C. The It it a fandy roafs interfperfed with m?ta Ik and fulphurcous particles. Its granules arc cryftalHne. Heat deepened its colour) and oxided the metal. Greater heat tufed it. It contained anuch magnetic iron, combined with mckel. Conftituent parts of the remainder. ON METEORIC STONES, The ftone itfelf is a Tandy mafs, formed of rounded ova? grains, the largeft of which are fcarcely bigger than hpmp« feed, among which are interfperled metallic and fulphu- rious particles w-th all their primitive luflre, and particularly with that light tint of kupfernickel obierved in the other (tones. On examining the earthy grains by the microfcope, we perceive, that, far from having been fafhioned by the movement of water, they are globules rough with cryftalline or reflecting points, fo that they can by no means be con- founded with fand. A piece of about two inches being expofed to a red heat in a crucible for half a quarter of an hour was much changed : the fandy globules became of a darker gray, and the metallic particles, diverted of their luftre, were vifibly oxided. About two ounces were heated for half an hour in a forge fire, which converted the (lone into a femivitreous mafs, blackirti, and (lightly porous. It did not appear to have effervefced much previous to fufion, and was interfperfed with globules of iron, which had not time to defcend, though upwards of a hundred grains of a regulus were collected at the bottom. The iron attractable by the magnet was not uniformly mixed in the ft one, as from fome parts 22 in the 100 were extracted, from others not more than 17. This iron was combined with nickel in the proportion of about 3 per cent. No nickel was difcoverable in any other part of the ftone. After this alloy was feparated by the magnet, the remainder of the ftone was found by analyfis to confill of, Iron fulphurated at a minimum - 12 Black oxide of iron - - 5 Silex 66 Magnefia - - - - 20 Lime and magnefja in quantities loo fmall to be appreciated Newhypothefis, Their origin probab y in the polar regions, 103 On confidering the rapid alteration of thefe (tones by moifture, for a fragment kept twelve hours under water was taken out covered with fpots of ruft, which diftinguithed the grains of alloy from the fulphureous particles with which they were before confounded ; — it is obvious, according to the author MR. GREGORY ON MECHANIC POWER, j *«ithor, that they cannot fubfift in any of the habitable parts of the globe. But from the eternal cold of the polar regions, where water remains for ever a folid mafsi, and iron cannot ruft, he thinks we may reafonably look to thefe regions as the native place of fuch bodies. In this he infifts there is nothing impoffible, or even improbable. And why (hould thofe whence they i j j c i • . i -A. .1 • • are convcyc* t» meteors, he demands, ot which we know neither the origin, ptj,er p:.rts ^ the combuftibles that afford them aliment, the impulfe by meteors. which they are moved, nor the nature of the lines they defcribe in their courfe, be lefs capable of tearing them from fome part of the globe, than pf forming them, contrary to all physical probability, from elements which the atmofphere can neither create nor hold in folution ? III. Farther Re?narks on Mechanic Power f in Reply to Mr. J. C. Hornblowtr. //» a Letter from Mr.O. Gregory, Royal Mil. Academy. To Mr. NICHOLSON. SIR, J. AM forry to be under the neceflity of troubling you with Prefatory a few observations for infertion in your Journal, in confequencercmar *' of being called upon by Mr. Hornblower, as though it were to defend fome newfangled doctrine, when the pofitions in my former letter, which that gentleman thinks proper to cen- fure, are in perfect conformity with the principles aflumed or demonftrated by every correct writer on mechanical philofophy fince it has been placed upon its proper bafis in the Principi* of Newton. The fubje<5t I am now invited to difcufs, has fo frequently been exhibited in the cleareft light by various authors, both in England and on the Continent, that I fhould rvot think myfelf juftified in occupying many of your pages by an elaborate diflertation ; put of regard, however, to fo refpedtable a correfpondent as Mr. H. J cannot help entering a little into the difcuffion, though I am, I confefs, quite unable to afcertain whether his laft letter is meant tooppofe my former remarks, and thofe of Profeflbr Robifon with ferious argu- ments, or is merely intended as ajeu d'ejprit. It 5 MR. GREGORY ON MECHANIC POWER. It will not, I hope, be ex peeled thai I fliould point out ill what inftances Mr. H's remarks appear to me completely ir- relative lo the fubject in hand; or thofe in which he Teems to have milunderftood the arguments of the late leared Profeflbr : fuch a procedure would m\\y- lead into farther difcullinn, while I feel folicitous to avoid it, from a confeioufnefs that it would be very uninlerefting to moft of your readers. I {hall flrive to confine myfelf, therefore, to fuch of Mr. H's enquiries as bear upon the point in difpute, and for the fake of condenfing my labour, fhall begin vyilh that in his poftfeript. Arc animal Fhil then, I will endeavour to " (Jet Mr. H. right as lo the cxerti n and idenfiiy of animal exertion and mechanic power:" and to this iacntical'/0 ' en(* ll w'" ^e rfcqudile to anfwer the queflion, — what is me- chanic power? excluding, for the prefent, that acceptation of the term in which it is underflood lo denote one of the fix fimple machines, Now, it is pretty obvious, that the terms power, force, &c. when ufed in mechanical fcience are purely metaphorical ; for, as PiofefTor Dugald Steward re- marks, (Elements * Water h$ At earn of Air condcnftd in its Defccnt through an inverted Syphon. By Mr. William Close. From the Inventor. To Mr. NICHOLSON. SIR, Dalton, July 27, 1S05. •Reference to the IN one of my letters, fome time ago, I briefly noticed an en'ine * *p experiment I had made, to determine the practical value of the hydraulic machine, or inverted fyphon, reprefented and defcribed in the firft volume of the prefent feries of your Jour- nal *, obferving, that, at fome future period, I might pro- bably tranfmit to you a more particular account. Having fince repeated the experiment, I now fend you a letter upon the (ubject, for I am of opinion that a machine operating upon the principle, when conliruded in the manner herein de- fcribed, will anfwer very well, in certain fituations, to raife water for domeftic purpofes ; and although it may not be com- petent to perform half as much work as a bucket engine by a forcing pump, yet it may be kept continually employed, and be fubject to very little wear, as its operation will almoit be performed without friflion. Dffcrlption of The inverted fyphon when applied to raife water in the another appara- manner defcribed jn this letter, has its higher orifice placed in a tituation to receive both air and water at the fame time* The air being conveyed by the velocity of the aqueous column • See Philof. Journal, Vol.' I. p. 30, PI. IV, to APPARATUS FOR RAISING WATER. \J to the lowed part of the fyphon, and collected in a veflel, is employed as the medium for conveying preflure to raife water in another part of the apparatus. In May 1803, I determined to find by experiment, under being an invert- what degree of preflure it would be moft advantageous to colled ^hSfcar'nes the condenfed air, and likewife the proportion then exifting down air and between the two fluids moving in the fyphon. The appa- condenfes lt> ratus conftru&ed for this purpofe, is reprefented in Plate L Fig. 1. It required only a fmall fupply of water, but con- denfed the air fufficiently to be employed in the actual con- ftruction of a machine upon the principle. A round vertical pipe AB, half an inch in diameter, and 22 feet 5 inches in length, had its higher end placed in the ciftern A, and its lower connected to a fmall oblong veflel C, which had an inverted glafs bottle cemented upo: 4 pro- jecting cylinder on its upper tide. From the other end of the veflel afcended another vertical pipe D E, half an inch in diameter, and 18 feet 3 inches in length, and terminated in a crook, 4 feet 2 inches below the highefl part of the pipe A B. The whole apparatus being filled with water, the ciftern and this air Is having a conftant fupply fufficient to keep the furface of the fore^flne fluid juft above the orifice of the pipe A B, when the orifice water, of emiflion at E was opened, the water flowing through A B, carried bubbles of air into the veflel C, which afcending, dif- placed the water in the bottle, and afterwards that contained in the veflel C, above the lower ends of the pipes A B and D E. At the firft efflux, and after the defcent of every ma- terial portion of air, the jet at E was projected feveral inches from the adjutage, but its curve decreafed during the defcent of more air; for the bubbles did not rife inceflantly into the bottle, but after fhort intervals of reft, diflodging two or three ounces of water each time, with a guggling noife, which was very audible to the perfon regulating the fupply of the ciftern. After the water in the veflel C was deprefled to a level with the ends of the pipes, the denfe air carried down A B, afcended through D E, and caufed frequent interruptions in the jet; for, expanding under a light preflure, it expelled the water in the higheft part of the pipe with violence, and then the efflux ceafed for fome time after. Vol. XII.— September, 1805. C '" " The 1$ APPARATUS FOR RAISING WATER. The condenfed air, however, could any time be let out, by a fmall pipe which was placed within the bottle, and opened on the outfide of the vefTel C. The pipe A B had a joint above the bottom of the cittern, to facilitate the trial of mouth-pieces of various forms, to find by which the apparatus would lip the mod air : and it appeared that no form, or pofition, conduced more to this efFecl, than when the pipe was crooked at lop to receive the water in a horizontal current, and the higher fide of its orifice was not more than two lines below the furface of the water in the cif- tern. It alfo appeared, that no lefs quantity of air was col- lected, when the diameter of the orifice of emiffion was re- duced to four lines, than when it was half an inch. Experiments to After feveral experiments to determine the quantity of ihew how much water requifite to fupply the expenditure from the cittern, and ried down with keep the furface of the fluid accurately at the height beft he water. adapted to the operation of the apparatus ; feveral trials were made to afcertain the quantity of air a given quantity of water would convey into the bottle in a given time. The remits of feveral trials on the 2lft of May 1S03, were as follow : J. The fall being 50 inches, and the orifice of emiffion four lines in diameter, the inverted bottle above C, holding ten ounce meafures of water, was filled with air, under the pref- fure of a column 18 feet high, by 14 pints of water flowing out at the orifice of emiflion at E, in 143 feconds. 2. By 13 pints, in 133 feconds. 3. By 12f pints, in 125 feconds. By 12 pints. 5. By 1 1 pits, in 95 feconds. 6. By 14 pints, in 114 feconds. 7. By 12 pints, in 102 feconds. 8. By 12 pints, in 10S feconds. 9. The orifice of emiffion being half an inch in diameter, the bottle was filled by 12 pints. 10. By 13 pints, in 133 feconds. 1 1. By 12| pints. 12, 13. The fall being 44 inches, the orifice of emiffion four lines in diameter, 1 1 pints filled the bottle in 95 feconds ; and 14 pints, in 120 feconds. With an height The difference in the time, and the quantity of effluent of 18 feet and t required to fill the bottle with air, in thefe trials, was fall 50 inches, ^ . r . oo parts of water probably occafioned by a portion of the air being fometimes earned down contained in the higher, and at other times in the lower part •ne of condenfed , - * « 1 /* 1 /*• r jir. ol the pipe A B, at the commencement or the errunon : or, perhaps, APPARATUS FOR RAISING WATER. 19 perhaps, in part, by the water in the ciftern not being always of the fame height; for the ciftern did not overflow, but was fupplied with great care, fometimes by a pump, and fome- times by letting water out of a veftel, always keeping the fupply from agitating the contents of the ciftern as much as poffible. Had the bottle been larger, there had probably been more uniformity in the refults of the trials. In eftimation, I think, however, we {hall not overrate the operation of this machine, by taking 13 pints for the mean quantity of effluent water emitted while the bottle was filling with air; and then deducting the quantity expelled from the bottle, it will appear that 20 parts of water carried one of air down the pipe A B : and as one ounce meafure of condenfed air at leafl was col- lected in 14 feconds, fo 16 pints would collect every hour. Some few days after thefe experiments, the pipe A B was Trial with a lengthened to 24 feet 7 inches, and D E to 20 feet ; but upon grater length trial, the air was carried into the bottle fo much flower than before, that a fufpicion arofe that fome part of the apparatus was not air-tight ; and on this fuppofition the pipes were taken down. In February 1804, the pipes, &c. were examined, and fet I^fs air was ear- up again with confiderable care. AB was 24 feet 7 inches ned down* long; D E, 21 feet one inch ; consequently the difference for the fall was 3 feet 6 inches. With this apparatus, when the diameter of the higher orifice of the pipe D E was four lines, it appeared by four trials (Feb. 25, 1804), that the bottle loft only one ounce of water per minute. When the pipe D E was fhortened to 19 feet 7 inches, and had its higher orifice five feet below the furface of the water in the ciftern, four ounce meafures of condenfed air defcended into the bottle, during the emiffion of 16 pints of water, through the orifice at E, when half an inch in diameter. The diminution in the collection of air, in thefe laft experi- ments, was much more confiderable than was expected to happen, either from the abforption of the water, or the in- creafed condenfation of the air, which might be occafioned by fo fmall an addition being made to the apparatus. The jet at E was projected more fteadily in thefe laft, than in the pre- ceding trials; and the condenfed air, inftead of rifing into the bottle in large detached bubbles, afcended in a continual ftream, like the evolution of gas from the bottom of an effervefcing C 2 mixture. 20 APPARATUS *OR RAISING WATER* mixture. From the minute divifion of the air, it is not im- probable, that a fmall portion might be carried along with the current of water under the bottle, and afcend through the pipe D E j but this was not determined. If there was no defect in the apparatus, it appears, that it will not be fo ad- vantageous, in the conduction of a working machine upon this principle, to employ a condenfing column fo heavy as 24 feet, as one that is lighter. Other trials. Feb. 2S, 1 804. The pipe A B being fhortened to 22 feet 5 inches, and D E to 18 feet 3 inches, the orifice of the ad- jutage at E being four lines in diameter, the bottle was emp- tied by 13, 12£, 14, 13, 13, 12, and 14 pints of effluent water, in feven fucceffive trials, as in thofe of May, 1803. March 9. With a fall 3 feet 9 inches, AB being 15 feet one inch, half a pint of air was collected during the difcharge of 12^ pints of water. Again, the orifice of emiffion being four lines in diameter ; the fall 4 feet 2 inches ; A B 15 feet 8 inches ; D E 1 1 feet 6 inches ; nine ounce meafures of air were conveyed into the bottle, in one minute, during the dif- charge of 10 pints of water, in five fucceffive trials: and when the diameter of the higher orifice of the pipe D E was half an inch, the fame quantity of air was carried down in 50 feconds, by nine pints of effluent water, including that dis- placed from the bottle. When AB was 15 feet 8 inches; DE 13 feet 2 inches; the fall 2 feet 6 inches; nine ounce meafures of air were collected in the bottle, by the difcharge of 16 pints, in 90 feconds; in 105 feconds, by 18 pints; and again, by 18 pints, in 90 feconds. March 16. The fall being 2 feet; A B 8 feet 5 inches; D E 6 feet 5 inches ; and the diameter of its higher orifice half an inch ; ten ounce meafures of air were collected in one minute; again in 64 feconds, when the effluent water mea- fured 10 pints; and again in one minute, when 10 pints. Having now (hewn what power a machine operating upon this principle may be expected to pofTefs, I proceed to fhew how its principle may be applied to practice. Defcrlption of Fig, 2, Plate I. exhibits a machine for railing water above the machine as lhe ciftern# conftrudted ror -.•* . railing watr, R reprefenls a cittern (upplied by a Ipnng, where there are by air condenfed fQUr Qr fiye feet faJ] for tne water# in an inverted -^ ^,r fyphon. ' W n' Apparatus for raising water. 21 WW, a well or pit fituated below the bed or lower level Defcription of of the ftreamlet ; its depth varying from 6 to 20 feet, accor d- ^nfl^&^j fo! ing to the elevation to which water is to be raifed above theraifing water, ciflern, and the number of proereflive columns by which itby a,r.co"dcnie APPARATUS FOR RAISING WATER. Dcfcrlption of wider and others fmaller, and by felting fuch of thefe to work the michine as as are requifite, for whatever may be the increafe or diminu* eonftru&ed for . M ' J raifing water, tion of power, the turning of the cock will be duly regulated by air condenfej by lne float# fvphon. The water which fupplies the pipe I, and afcends in the apparatus, fhould be cleared, by filtration, from impurities and fubflances that would obftrucl the clofure of the valves, The ciflern mould have a moveable piece at the place where the water overflows, to accommodate the furface of the fluid to the ends of the pipes, that the full quantity of air may de- fcend with each column, and that the maximum of efiecl may be obtained from the fupply. To determine how well fuch a combination as that I have defcribed would anfwer the purpofe, I had a model con- structed upon the plan exhibited in Plate /. Fig, 2 ; but having no convenience for an overflowing well or ciflern, I was obliged to modify fome parts, in a manner tending to diminifli its power. The water from the ciflern R, falls into a capacious veflel, from whence, when the machine is at work, a hand-pump continually raifes it again into a veflel above, which fupplies the ciflern R through a pipe nearly half an inch in diameter, under a conflant preflure of 3| inches charge. The fupply keeps the ciflern continually overflowing, and the furface of the water is calm and always at the fame height. The pipe A A is 8 feet 3 inches in length, and half an inch in diameter. Its lower end is inferted into the veflel B, which is clofed at bottom, and conflrucled of fuch a form as to in- clude the lever which carries the float. Above that end of the lever bearing the counterpoifing weight, a vertical pipe 6 feet 3 inches, is connected to the top of the veflel ; and through this pipe, which is no wider than A, the water afcends and flows to the pump: A chain, confifting of pieces of wire four or five inches in length, looped together by the ends, alfo pafles through it, and connects the float-lever to that which moves the re-curved fyphon S. The bottoms of the buckets M are both together 14 inches long and 6 broad. The bale partition is 4 inches high. Each bucket has an end parallel with the bafe, one inch deep, pro- vided with a hole to let out the water when deprefled. The cock moves with lefs than a pint of water in the elevated bucket. The APPARATUS FOR RAISING WATER. Q*J The float in the veflel B, is a fmall cylindrical copper Description of veflel, one inch in height and two inches in diameter. It conftruftedVor was filled with water and clofed before it was fixed in its railing water, place. Though equal in bulk only to one ounce and three ^ a',r.condenfr . . " . r i. . in an inverted quarters of water, yet it is quite Uifncient to move the fyphon fyphon. which would work a larger machine. The pipe C is half an inch in diameter : E, K, G, L, are fmaller. The valves are leather. This machine, when in good order, raifes water nearly 12 feet above the ciftern, at the rate of 20§ pints per hour, and performs all its operations as well as can be defired. When. firft fet to work, the cock is fo placed as to clofe the top of the pipe C, until the condenfed air begins to collect in the veflel B, and then the communication is opened to the cham- ber F. If the communication was open at firfl, the water would be expelled from F into the ciftern, while the preflure was inefficient to clofe the valve in the pipe I. The chambers F H being fmall, the fyphon moves fre- quently ; but in a working machine thefe veflels fhould not only be broad and fliallow, but capacious, that the wear of machinery may be reduced to its ulmoft extent. To determine what quantity of water flows through the apparatus, I fixed a fpout upon the top of the afcending water pipe ; but in doing this I entangled the float in the veflel B, that it could not be made to work the fyphon. The effluent water, in this unemployed ftate of the machine, including half a pint difplaced from the veflel B, amounted to 8| pints. The fuperflucus water from the ciftern R meafured 8| pints alfo. If the machine had been working the wade water would have been Iefs^ as part would have been drawn off by the fyphon. From feveral trials, this model appears to raife water above the rate that might be eftimated by the experiment of March 6, previoufly related. In actual practice, I think the allowance for wafle and working the buckets, of one third or perhaps only of one fourth of the fupply, will be fufficient ; then fuppofing the apparatus fo adapted to the fupply, as 28 or 30 gallons from the cittern will raife one gallon 18 feet, fo 84- or 90 gallons will raife one gallon 44 feet, by three afcending columns. Th» gg ON THE MAXIMUM DENSITY OF WATER. The bucket-engine at frton-Hall, in Cumberland *, i$ faid to raife one gallon of water 60 feet high by 36 gallons fupply ; hence, if the wade water be included, it appears that our machine will not be competent to perform half as much work by the fame fupply, and its peculiar advantages muft depend upon its durability when conftantly employed. I am, Sir, Your's refpe&fully, WILLIAM CLOSE. V. Remarks on Count Rumford's Experiments relating to the . Maximum Denfity of Water. In a Letter from Mr, John Dalton. To Mr. NICHOLSON; SIR, Count Rum- IN your Iaft Number, page 225, is an interesting article on ncs onPthe ^e clue^:'on> At what point of temperature water is of greatefi max. denfity of denfity ? From the introductory paragraph I was led to expect, TJ"*f°** that all the material objections to the current doctrine were confidered and obviated, and that new and convincing argu- ments in its fupport would be adduced. In the former of thele expectations I was altogether difappointed ; and though the new experiments are ingenious and well worth attention, they are not quite fo demonnVative to me as they appear to be to Count Rumford. Perhaps we may both be too ftrongly biafied towards preconceived theories : however this may be, it feems proper that when new facts are brought forward, we ought to reconcile them to the theory efpoufed. Mr. Dalton's At page 93 of Vol. X. of this Journal, I have ftated a num- exper. in this ber 0f fa$s ancj experiments which appear to me irrecon- ftai^fobjedh cileable with the notion of water being denfeft at 40°. I believe it is denfeft at 32°, or the freezing point ; and it is my prefent intention to (hew how, on my hypothefis, I ex- plain Count R.\s refults. * See Philof. Journal, Vol. II. p. 60. Water ON THE MAXIMUM DENSITY OF WATER; 29 Water expands by heat from fome point (whatever it may. Count Rum- prove to be) by a law which is nearly that of the fquare of ^J "^aIi'„edf the temperature from the faid point, as is evident from Sir on Mr. Dalton'* Charles Blagden's table. Confequently the force of afc^^ftttery which water acquires by temperature, is at firft very fmall, \jtt\t change of but increafes to a very confiderable amount before ebullition, dimenfion* by J n c heat or c0'® near The cohefion of the particles of water is a conltant force; its max< denfity. there will therefore be a point of equilibrium between thefe two forces; that is, a point at which the increafed temperature will be but jufl fufficient to counteract the tenacity, in which cafe no internal motion can enfue. Whether a diminution in denfity in water to the amount of one hundredth or one thou- Jhndth, or one ten thoufandth or more, is the point alluded to, is to be determined only by experiment. I apprehend that This change at water of 40° is about one ten thoufandth part lighter than water ^^0™*^,." of 32°; but that this force of afcent is but juft fufficient a current j to counteract the tenacity, and confequently no motion takes place ; in fuch cafe the diffufion of heat through water is the fame as through a folid body. Whenever the difference in denfity exceeds thut jufl: mentioned, internal motion is thecon- fequence, and that greater in proportion to the difference of denfity, which we know may amount to J? of the whole. Count R.'s experiments therefore will be explained by ob- — and therefore ferving that the thermometer acquired heat by the proper con- ^d"^^* dueling power of water, as if it had been metal, or any other wards as if thro* folid body; the temperature acquired was greater in the 2d jfht't*** m experiment than in the lft, becaufe the heat of the ball was atures there wat greater; but in the 3d experiment the heat of the ball was a current, which fuch as to produce a current upwards that almoft precluded defcent. the defcent of heat, by carrying away the heated particles as foon as formed. The circum (lances of the two thermometers by the fide of plfficu^y re- ., , „ , jL ,, c a • , » • • 'pectingthe two the ball and the cup, in the two nrft experiments not acquiring thermometers. any temperature, is certainly remarkable, and not eafy to be explained, even upon Count R.'s principle; for, the fuppo- fed defcending current of warm water fliould have filled the cup and overflowed, fo as to affecf the collateral thermometer. One moft important experiment Count R. has omitted, and important expe- which it is particularly defirable that he, or fome one in pof- Let the wTieVbe. feffion of a fimilar apparatus, would perform, efpecially as it at 400 and the would go further than any other to eftablifh th# doctrine of cur- °' at 3Z • rents SO BENDING WOOD. rents in water, when the temperature varies from 32 to 40°. This is to repeat the 1(1 experiment, with the difference that the mafs of water fhould be at the temperature 40°, and the ball at 32° ; in which cafe the thermometer in the cup would not be at all afFeded upon Count R.'s principle; but if the explanation I have attempted above be accurate, no material difference in the refults of the two experiments would be ob- ferved. I am your's, J. DALTON. Manchejler, Augujl 17, 1805. VI. On the Art of bending Wood. By J. H. Hassenfratz.** Either live or JL HE operation of bending may be performed either on live blended. ""* or ^eac* w0°d> the proceffes differing however for thefe two fiates. I. On the bending of Live Wood, Live wood may Live wood has a natural elafticity f , which varies according ** to its fpecies, fize, and age. The larger and older the wood, the lefs elafticity it polTefles. This operation is performed on wood when growing, either to flraighten it, to give it a figure fuitable to the ornamental purpofe for which it is defigned, or to (hape it to the ufe for —bended for which the timber is intended when cut. Thus trees may be fhip-.build.ng, or bended, which are intended for the building of fliips, or for wheels &c making the felloes of wheels in one piece. Bv fattening When trees are yet young and pliable, their ftems are faft- dowh y«unS ened down by ropes, or poles, or flakes, or frames. In this fituation they are confined till they will retain when let loofe the curvature that has been given them. This themoft Of all the modes of bending timber the mod eafy and com- eafy procefs j modious is that applied to young growing trees: for their pli- * Tranflated from the Journal des Mines, N. 94, p. 475, July, 3 804. ■f In many parts of this paper the writer feems to have ufed the word elaflicite for the property of undergoing flexure without break- ing. T. antnefs BENDING WOOD. 31 dntnefs and elafticity enable them to acquire any form that may be defired ; fo that there are few to which the moll whimfical figures may not be given, with due care and the requifite pre- cautions ; but at the fame time we injure their natural confti- but injurious tution, retard their progrefs, and frequently reduce them to a t0 l e timbcr« ftate of conftraint and difeafe prejudicial to their growth. II. Of the bending of Dead Wood, The bending of wood that is cut down and dead, though The bending of ° • ° dead wood is more difficult, is yet more m ufe, becaufe we may choole fuch moft advantage- as is beft adapted to the purpofe for which it is defigned, andous# then give it the fuitable curvature. The procefs generally employed is founded on the property The principle is caloric poflTefies of augmenting the elafticity of wood by pene- he^,a ^Ich in- trating it, and diminiming this elafticity on quitting it. creafes the pli- Thuswhen we with to bend thin pieces, as the ftaves of ^nefs of tim' barrels, or the planks of boats, we heat them at the part that is to be curved, and bend them gradually as they grow hot. But heat applied to one part of the wood, while the other Pa«*»1 heat af- is in contact with the air, heats it unequally, and increafes the unequalj and pliablenefs but partially ; fo that on bending it, fome parts are occafions it to ftiff and others yield, occafioning an unequal curvature, andcrac or *Mner* fometimes cracks or fplinters in the infide or on the furface of the wood. The only method of remedying this inequality is to heat the wood equally throughout. Furnaces or ftoves gradually heated are adapted to the pur- Furnaces or pofeof affording a uniform heat, and confequently facilitating ftjvesheatit the curvature of the wood; but in ufing them there is reafon may fcorch it. to fear, that the caloric, while heating the wood, may expel from it the fluids contained in it, char it, and wholly deftroy its elafticity. The pliablenefs of wood is in proportion not to its temper- Humidity as ature alone, but to its humidity likewife. The fame wood at ceffary tQe render the fame temperature will be more or lefs pliable in proportion wood pliable. to the water contained in it; and at an equal degree of moif- ture its elafticity will be proportional to its temperature. We have an inftance of the double influence of heat and The lingular moifture in joining two pieces of wood with a tenon and mor- mortife^nd * tife, where the mbrtife is only a third of the breadth of the tenon, piece that is driven into it to form the joint. Thefe joints, fo extraordinary in appearance, furprife people fo much, that 3 moft \ / J£, 32 SENDING WOOD. Heat and moif- rnofl of thofe who life them make a myftery of thera. The ture are to bend 16 "timber- Proce^s employed in this operation has given rife to the method at prefent in ufe for bending with eafe the largeft and fiiffefr timber: it confifisin penetrating it with humidity, and at the fame time imparting to it a uniform temperature, then bending it, and letting it coo!, while it is kept in the form to which it has been brought. —In three dif- For heating and moiftening the timber, three different pro- entwajs: ceffes have been employed: firir, boiling water; fecondly, fleam; the third, wet fand heated. i ft. By boiling The flove for the firft procefs confi (Is of a large copper boiler, heated by three furnaces, clofed by a movable cover, and varying in its dimenfions according to the fize of the tim- ber for which it is intended. Cranes are ufed for raifing the timber, and putting it in or taking it out of the boiler, which is kept full of water. When the timber is in, the cover is put on and beaten down clofe, to diminish the evaporation of the water; the three fires make the water boil, the timber is heated and penetrated with moiflure, and it is then taken out to be bent. This diflblves This procefs, one of the flrft that was employed, has the fome of the com- defe6l of din-oIving a part 0f the proper fabflance of the wood ponent parts, and , > or ^ . lefiens the di- in the boiling water ; the timber (brinks in drying, fo as to mentions of the become narrower and fhorter ; its ftrength and elaflicity are confiderably diminiftied, and from thefe alterations occafioned by it the procefs is difufed. 2d. By fteam. Figures 2, 3, and 4, PI. II. reprefent the plan and ele- th^fteamer vations of a fleamer. It confifls of a large wooden box, formed of flout planks, held firmly together by fquare frames. Within are fupports for the timber that is to be expofed to the aclion of the fleam. The dimenfions of the box are regulated by the fize and quantity of the wood intended to be foftened. For fmall fleamers a boiler is fixed at one extremity of the. wooden box, and the wood is introduced at the other through an opening, the door of which either Aides in a groove or turns on hinges. For large ones the boiler is fixed in the centre, and there is an opening for the timber at each end. In the fide oppofite the boilers are openings aaa for arranging the tim- Ir fhouM be co- ber on the fupports. It is ufual to leave the wooden boxes ex- b^ccSuaor^of Pofed lo tlie aIr externaI,y 5 but il would be of advantage to L;at. COVet BENDING WOOD. 33 cover the planks with fome fubftance that is a bad conductor of heat, to confine the heat that is difengaged from the fleam within. Each boiler having a communication with the interior of the bt)x, by means of a pipe, the fteam is diftributed to each ftage by the tubes bb b, Fig. 3. The vapour arifing from the boil- ing water penetrates the timber with moifture> heats it, in- creafes its elafticity, and renders it fit to be bent. Steamers require little care, and little expenfe, but they This procefs Is cannot be ufed for timber of any great thicknefs, fince they no/expenfivc8" cannot impart a emperature higher than that of boiling water, but it is not hot and this is not fufficient to give large pieces the degree of pli- *™J J for u& ablenefs neceflary for bending them. This lownefs of temperature gave rife to the invention of 3d- By wetfcnd» the fand-ftove, which is formed of four ftone or brick walls, defcribed. In the middle are two furnaces, with which feveral circular flues communicate, for conveying the heat, the heated air, and the fmoke, to a chimney rifing from each end. On thefe flues are plates of caft iron, which form the bottom of the ca- vity in which the fand is placed ; the flame and fmoke circu- lating in the flues heat thefe plates, and thefe plates heat the fand. This is an imitation of thofe fand-baths which have been long employed in many chemical procefles and in feveral ma- nufactories. As the fand may be heated to a temperature above that of boiling water, it can communicate a greater heat to the tim- ber; but were there nothing but fand and timber in the ftove, all the gafefiable fubftances in the limber might be expelled by the heat, and the timber charred. To prevent this, one or two boilers filled with water are Steam mu ft be placed in the middle of the ftove. The water converted into ufed withthe fteam by boiling penetrates the fand with moifture ; this im- ' parts moifture to the timber; and thus the heat that pervades the timber expels from it no more moifture than is replaced by the fand, to that all the proper fubftances of the timber are preferved. We will not venture to affirm however, that no portion of and the timber the component parts of the wood is evaporated in this opera- J^yy injured, tion, and that confequently it undergoes no alteration; but with the precaution of taking out the wood to bend it asfoon as it is fufficiently heated and penetrated with moifture, the injury is imperceptible. Vol. XII.— -September, 1805, D The 3^ BENDING WOOD. The fand-ftove is covered throughout its whole length, to retard the evaporation of the moifture contained in if, and allow the heat to accumulate fuffieiently to give the wood the proper temperature. Manipulation The pieces of timber are introduced at the ends, placed in forthchcac tf,e niiddle of the flove in the direction of its length on bars fixed for the purpofe, and covered with fand. When the timber has been heated and penetrated with moifture to the proper degree for enabling it to aflame the de- gree of curvature required, it is bent to a line defignating the curve. The wood may The timber may be bent in two ways, either horizontally or zpntaMyor ver- vertically; the former is ufed for pieces of fmaller dimenfions tkally, and greater curvature. —by any me- In either way the force that produces the curve is applied chamc power; by means 0f ropes, tackles, or even capftans. The piece mud be kept in the (nape to which it is brought, and thus left to dry and grow cold, when it will retain the curvature given to it. -.which may be Frequently when the piece of wood is thin, prefTure by applied various hand, or by weights, will bend it fuffieiently, fo that it will retain its fliape on cooling. But the means of bending it may be varied to infinity, according to the elafticity of the timber, its fize, its temperature, and its humidity. VII. Experiments made in the great, in a reverberating Furnace onCafi Iron, confirming the ejlabliflied Theory refpecling the Difference between cuft and malleable Iron. By G. A. Lampadius, Prof, of Chemijlry and Metallurgy at Freyberg* The reverber«i- 1 SHALL firft defcribe the reverberatory furnace ufed in fcr7bedU.rnaCC dC~ thefe experiments. It had three principal parts: 1. the air tunnel * Extracted by J. F. Daubruflbn, in the J. des Mines, from the Sammlung PraSiifch-chemifcber Abhandlungen <■ Practical Chemical Eflays,' of Lampadius, Vol. II. p. 1 4j. Priiequeftion In l~y5, the Royal Society of Bohemia propofed as a prize quef- o( Bonemian tion to fettle the theery of the refining of iron, taking as abatis the Society, 1795. 1 abouis of Vandcrmonde, Beithollet, and Monge, on the different ilates OK CAST IROK. 35 funnel and afh-hole; 2. the fire-place; 3. the hearth and chim- Tt was an a'r »t, . . , , ' r i m ii s furnace having ney. I o obtain the proper degree of heat, the air was con- an hearth within dueled through a vertical tunnel feveral ells long (the Saxon ell and its chimney is near two Engl ilh feet), the lower aperture of which was was l6feethlgh • over a ftream of water, and confequently it brought rapidly to the fire-place a (upply of frefh and condenied air. The fuel was wood; the bottom of the furnace was an oval cavity, covered with a heavy coating, and capable of containing three or four hundred weight of metal. The flame, which traverfed the furnace with rapidity, efcaped afterwards through a chim- ney eight ells high. The furnace had an opening capable of being clofed at pleafure by an iron door. There was another above the fire-place, a few inches fquare, ferving to admit the nozzle of a pair of bellows, or the neck of a retort. In the ufe we made of this furnace I had an opportunity of11'10*'^ parti* obferving very diftin&ly, that in the flame of a clofed reverbe- ^"b°e ^[h^ ratory furnace there are always a multitude of unoxided par- flame of this tides of carbon, which impart to it the capability of reducingclofedfurnace* (difoxiding) metal. This opinion I had already announced on occafion of a memoir of Mr. Dacamdra. In fome of our trials, making ufe of the wood of the Scotch fir, we obferved, that the fmoke ifluing out was black and denfe, and this the more the freftier the wood ; but as foon as we made ufe of the bellows, the flame appeared clear, becaufe the oxigen intro- duced by the air or vapour oxided the carbon that was in the flame, and thus produced a greater heat. Firft Experiment with thefimple Fire of the Furnace, Exp. L The furnace having been heated for fome hours, and the fire GraY flne grain-' being very violent, about three hundred weight of metal was ** "f ^"be- taken from the crucible of the high furnace, and poured into ratory furnace, the reverberating furnace. This caft iron, when become folid, "veredwith r frothy lcona, was gray, and of a fine grain. At the expiration of an hour chiefly carburet a frothy fcoria appeared on the furface of the metal, which, to of iron* itates of iron. Mr. Lampadius fliared the prize. His memoir may be confidered in general as a confirmation and fupplement to the la- bours of the French academicans $ the experiments which he made at Muckenberg in Saxony, in the iron works of Count Von Ein- fiedel, affording him frefh proofs of this theory. Thefe experi- ments are hereprcfented to the reader. D. D 2 judge 36 ON CAST IRON. judge from appearances, confifted chiefly in carburet of iron. Not removable We attempted to remove it; but asfome of the metal adhered for adhering to j^ anci came away at the fame time, we defifted. Soon after, the furnace being clofed, we heard a continual boiling, refembling that of a vifcous fubftance in a clofe veflel. On The metal was opening the furnace, we perceived that the whole matter in brought to ebul- reality boiled, and that bubbles were continually rifing, which Carburated hi- burft on the furface with a beautiful bluith flame. Thefe jets drogen gas evol- of flame had the colour exhibited by carburated hidrogen gas. The boiling continued as long as the fire was kept up ; at the fame time a pretty large quantity of fcoria was formed, which however could not be removed, on account of the vifcous con- fidence now acquired by the metal. Befides, as the metal was frequently ftirred to prefent a frefli furface to the air, the fco- ln five hours it ria mingled with it. At the end of five hours it was no longer became white fluid, and appeared to be refined. It had loft its gray colour grained, and finenefs of grain, was white and coarfe grained, and and a little mal- fhowed itfelf more malleable, though it was not capable of be- This^was after- mS f°rged. The refiner carried it to his ordinary furnace, and wards refined there it was refined in lefs time, and required lefs labour than foonerthan com- common cafl ; mon caft iron. . As in this trial we were unable to feparate the lcoria, and refining °iron in no change had been made in the form of the hearth of the a reverberatory common refinery, which ought perhaps to have been done, nothing poiitive can be advanced with refpeel to the practical advantage of refining by the help of reverberatory furnaces ; we were merely convinced of its poffibility, and enabled to demonftrate the theory of this procefs, that is to fay, of feeing ft • th tear- c^ear'y wnat paffed in the operation. The caft iron was here bon is burned converted into malleable by means of the oxigen that was in oft# / the little atmofpheric air, which, jointly with azote and car- bonic acid gas, covered the metal in fufion. This oxigen combined with the carburet of iron, and then carbonic acid gas and oxide of iron were formed; this produced the bubbles of air and the fcoria. The lightnefs of the frothy fcoria, which arofe to the furface at the beginning, was the reafon of their leparation from the reft of the mafs j but as foon as the air be- gan to act they were deftroyed. Second ON CAST IRON. 37 Second Experiment ; the Fire of the Furnace being ajfijted by the Exp. II. Vapour of Water. I had attempted to decompofe carburet ofiron in fmall quan- The carburet of tities by the help of water in the ftate of vapour. By heating j,^ bAquwus the carburet red hot, the water was decompofed, and I ob-vapour. tained carbonic acid gas, hidrogen gas, and oxide of iron. As the chief difference between caft and malleable iron coniifts in Application of a certain quantity of carburet of iron contained in the former, ^JJ""'^' to and which mud be feparated to render the iron malleable, I was defirous of trying the effect of water in vapour on caft iron in a reverberatory furnace, principally in order to know how far the refining of iron might be carried on in this way. About three hundred weight of caft iron of the fame quali- ty as before, and juft taken from the high furnace, were put into the reverberatory furnace as in the preceding experiment ; we then took a large tubulated iron retort, put into it nine or Steam was in- ten quarts of water, fitted a gun barrel to its neck, and intro- troduced» duced the end of the gun-barrel into the little opening in the furnace. The water in the retort was made to boil, fo that the fteam diffufed itfelf with the flame over the melted metal. At the expiration of half an hour all the marks of refining that had been obferved before were perceptible ; the ebullition was by which confiderable, and the flame that iflued from the chimney more pr0ceededqu?ckp bright. Two hours after the commencement of the procefsly, freth water was put into the retort. In about three hours thp metal began to thicken, and at the end of four hours it exhi- bited the marks of refined iron, and we imagined the opera- tion to be finiOied. We found the grain of this iron finer, but the iron however, than that of the iron operated upon in the V^^^S^lof^kbf^' experiment, and the mafs was full of little blebs. We gave it to the refiner, who treated it like the former ; arm was lefs but to our great aftonifhment we found that it wrought worfe "|^de ^^"f in the refinery fire than caft iron the moft difficult to refine. It fore, required much more labour, and an hour's time longer. Having aflayed a fpecimen in the ftate in which it came out There was more of the reverberatory furnace, I found it to contain a much Jar- ^arTin other'* ger quantity of oxigen. Experience had already taught me, kinds of call that half a pound of gray caft iron, treated in a retort with110"* four ounces of charcoal from which all carbonic acid gas had been 38 ON CAST IRON. been expelled, gave 32* cubic inches of carbonic acid gas. An equal quantity of white cart iron afforded 165 cubic inches of the fame air. Four ounce* of the call iron juft taken from the reverberatory furnace, mixed with two ounces of charcoal, yielded 96 inches, or 192 inches to half a pound. Hence we may infer, that the proportions of oxigen con- tained in thefe different kinds of caft iron are, In iron fuper-refined by the vapour of water - 192 Common white call iron - - - - - 165 Gray call iron - - - - - - 96 Th'sfuper- To the iron produced in the experiment juft mentioned, I refined iron im- -e the epjtnet fuper-refined f, becaufe I conceive it to have bibed oxigen ? r from the de- been formed as follows: — The water in vapour was decom- compofed water p0fed, and deflroyed the carburet, asatmofpherie air does in which deftroyed , ,. . . , * > . . ■ - , its carburet. tne ordinary refining ; but at the lame lime this water imparted to the iron fo large a quantity of oxigen, that in the refinery it was neceflary, not only to feparate the fcoria, but to difoxide the metal like wife. This experiment farther confirms the pro- perty iron poffefles of becoming oxided in different degrees. If this experiment afforded nothing practically beneficial, it has at leali thrown fome new light on the properties of caft iron. Exp. III. Third Experiment ; the Fire of the Furnace being aJJJJled by the AStion of Bellows, Bellows applied The fame furnace was ufed, and the place of the retort in with the rever- ^e preceding experiment was fupplied by a pair of double beratory furnace. , ,, ' , . , . * , r ■ x i „ ,„ r bellows mounted with leather, 5 teet (4-r. 8 in.) long, 3 (2 r. 10 in.) broad, and 4 (3. f. 9 in.) high at the poflenor extremity when open. It was fo placed, that the dream of air was pa- rallel to the flame and to the middle of the furnace, and worked at the rate of eight or ten flrokes in a minute. We were de- firous of feeing how far the air thus allifled would carry the refining ; the furnace being managed and filled as before. The heat was -At the end of half an hour the heat was perceived to be much greater, much greater than in the firfl and fecond experiments. The phenomena of the refining already mentioned appeared in fuc- * Probably this is an error of the prefs in the original : as it does not agree with the proportion affigned in the next paragraph, one of the two muft be wrong. f Or furcharged with oxigen. ceffion; ON CAST IRON. 39 ceffion ; bat inflead of the frothy fcoria obtained in the firft The fcoria eflay, a very fluid ftratum was formed, which diffiifed itfelf m over the melted metal, and prevented its refining. This fco- It was blackirti ria, when grown folid, was of a blackifli brown colour and £™ ""j^a* *£ vitreous fracture. We endeavoured more than once to re- and not to be ■move it, but the flratum was fo thin as to render it impracVi-reraoved* cable : As foon as one ftratum was removed, another formed. Stirring pro- At the expiration of four hours, the metal being ftill very fluid, J^*^™ we began to ftir it, in order to bring its different parts fuceef- filiating com- fively into contact with the air ; this produced an extraordinary buftion. heat in the furnace, combuftion, and fcintillation, refembling that which takes place when iron wire is burnt in oxigen gas. This oxidation always produced freth fcoria : as foon as we defifted from ftirring, every thing became quiet, and the ftra- tum of fcoria prevented the oxidation. At length, after three hours longer, making feven in all, during which the melted niafs had frequently been ftirred, it feemed to thicken ; per- ceiving too, that it diminished confiderably in quant'* y, the fire was damped, and the matter left to cool in the furnace. It T!?e lton, had • i i r it • *°": muc« m was afterward weighed, and found to have loft much of its weight. weight. Its extraordinary fracture gave reafon to prefume a Its fracture com- high degree of oxidation ; for inflead of being gray and gra- p3 "'very, nulous, it was compact, and of a filver white. It was inter- Porous, fperfed with a large quantity of fpherical cavities, greater or lefs in fize, which evidently announced the exiftence of an ae- riform fluid, that had been extricated during the fu (ion. This mafs was too fmall to be refined. Having examined There was much the quantity of oxigen it contained in the fame manner as withyj^j^g,. ac_ the other fpecimens, I found that four ounces yielded 87 cubic quired much ox- inches of oxigen gas, and coniequently nine inches lefs thanisen> that which had been treated by means of aqueous vapour. Thus probably here too the oxidation was too powerful, and the iron was fuper-refined. As the metal did not become without pafling doughy in the courfe of the proeefs, it muft have been fuper- thvou§" tJje h J ,. malleable ftate. faturated with oxigen without pafling through the ftate of mal- leable iron. The carburet, it is true, muft have been totally The carburet deftroyed during the operation, which produced the fiivery deftr°yed* hue. Remarks 40 BURSTING OF TWO MTJSQVET BARRELS. VIIL Remarks(on the burfiing of two Mufquet Barrels by a Charge of Gun-powder confined by Sand. W. N. A thin mufquet A ART of ihe barrel of a mufquet of which the internal di-» barrel burft. ameter was fix and a half tenths of an inch, was corked at one end, and fine fand to the depth of twelve inches was poured in: upon this was poured two inches of gunpowder and a fmall tube (of glafs) was then ftuck in the gunpowder, and the bore of the tube, which was about one twentieth of an inch diameter, was filled alfo with gunpowder. The length of the tube was fufficient to reach clearly above the top of the gun-barrel, and all the reft of the fpace in the barrel, being about thirteen inches above the charge, was filled with fand lightly poured in. In this ftate the barrel was fet up in one corner of a furnace chimney, and a match ftuck into the glafs tube and lighted, afforded fufficient time for the affiftants to re- move out of the diredt line of explofion before the efFecT; could take place. The difcharge tore the barrel into feveral contorted pieces in the part near the charge ; the upper part fell unaltered, and its contents of fand ran out : the lower part alfo fell down, but neither its fand nor cork were difturbed, nor was that por- tion of the barrel afTe6led. As the thicknefs of the iron did not exceed one thirtieth of an inch, I was defirous of repeating the experiment with a ftronger piece. A thicker bar- A mufquet barrel, 2f feet long, diameter of bore five tenths rel charged with 0f an jnc|^ an(j thicknefs of metal at the breach full one quar- gunpowder and t r . , ..,<•,. . ,. , fand. ter or an inch, was charged with 278 grains, or a little more than half an ounce troy of gunpowder, which occupied the fpace of four inches. Upon this charge was poured fine fand to the depth of twelve inches, weighing 1151 grains, or about 2-J ounces troy, and upon this was lightly prefled down a foft wadding of gauze paper, for the purpofe of allowing the bar- rel to be placed horizontally without any fubfequent difturbance of its charge. It was fafely placed in an horizontal pofition and fired at the touch hole by means of a train. Effect of th ^ie karre' was torn amn^er f°r tne length of eight inches, explofion. the part neareft the breach-pin being opened nearly to flatnefs. The VELOCITY OF PROJECTILES, 4J The fand remained in the barrel. Its face neareft the blaft was confolidated to a very fmall depth, and I think the mafs ha4 |?een removed or elfe jammed more clofely together; for the fpace unoccupied between the place where the breach pin had teen and the furface of the fand was full nine inches. But as the fand was not immediately noticed, I cannot be fure that yone might have been driven or fallen out, during or after the blaft; ; though I am difpofed to think not. It muft be remarked, that the powder was a very full charge, Remarks, and that the fand weighed as much as fix muflteb-balls of half an inch diameter. I do not however apprehend that the barrel would have burft with fix balls. The blading of rocks, the fplitting of logs of wood, and Ufee, the deflruc^ion of artillery when on the point of being aban- doned to the enemy, are the leading purpofes in which the ap- plication of fand to confine gunpowder is likely to become ufeful. IX. Report of a Method of mcafuring the initial Velocity of Pra? jecliles difcharged from Fire-arms, both horizontally and with different Elevations^ made to the Phyjical find Mathematical Clafs of the National Inftitute by Mr. Phony, Dec. 11,1 803. Abridged from the Original*, AT is not much above fixty years fince experiment began to Robins firft esca- pe applied with fuccefs to' the theory of projediles. Mr. ™™*( *■ J^0* Benj. Robins, who may be efteemed the firft in this career, tiles by the pen- employed a pendulum to determine the initial velocity of "dulum» mulket balls, meafuring it by the arc of ofcillation. He like- and the recoil of wife meafured the recoil, by fufpending the gun-barrel from \^&tlz\k., the pendulum. About ten years after, the Chev. d'Arcy publifhed a feries D'Arcy made of experiments in the memoirs of the French Academy of fim,lar "J?6"" ... } ments with tw» Sciences, in which he employed two pendulums, againft one pendulums. of which the ball was projected, while the other, to which the gun-barrel was fufpended, ferved to meafure the recoil. * Journal des Mines 3 No, 92, p. 117, May, 1804. Fifteen 4*2 VELOCITY OF PROJECTILES. DwHutton with Fifteen years after this Dr. Hutton made many experiments cannon balls. at Woolwich with cannon balls by means of the pendulum. Count Rum- About the year 1778, Count Rumford improved this me- furd s improve- ^^j ^ (r\a]f anci invented a very fimple method of fufpending the gun-barrel fo that the recoil took place without the axis Chafing to be horizontal. Dr. Hutton's Laftly, Dr. Hutton refumcd the fubject, and made a number "oft complete ^experiments from 1783 to 1786, with much care, and at onthefubjed. great expenfe, on both kinds of pendulum. Thefe may be confidered as forming the fnofl complete and inftru&ive treatife we i)3ve on experimental balliftics. Antonys de- We have not mentioned the labours of Antoni, but we muft fcnption ot ■ z- m)t j)afs over a maci,jne Jofci ibed by him in his effay on gun- j)ovvdor. This, which he fays was invented by a mechanic named Mathey, con lifts of a horizontal circle, the centre of which is fupported by the fuperior extremity of a vertical axis, and ferves as a bafe to a cylindrical envelope of paper. A rotatory motion is given to this cylinder by means of a cord palling over a leading pulley ; and the projectile being dis- charged horizontally, when the angular velocity of the machine is uniform, in a vertical plane in which the axis is found, pierces the cylinder in two points, the di fiance of the fecond of which from the diameter palling through the firft meafures the arc defcribed by the machine during the paflage of the pro- jectile. Col. Grobcrt's The machine recently invented by Col. Grobert is con- newly invented flru(5led as f0U0WS . machine de- . fcribed. A horizontal rotatory axis about 34 dec. ( 1 1 feet) long carries Itconfiftsoftwoat each extremity a pafteboard dilk perpendicular to it, and pafteboard <«*» faftene &c. to his apparatus, by means of which the weight, when it has defcended to a certain point, puts in motion a fecond pendu- lum to count the time, and a fyftem of wheels and pinions connected with the wheel and axle to indicate the number of turns made by it. By fimilar contrivances it difcharges the gun, and flops the pendulum and the counter of the turns at the proper time. Thefe may occafionally be of ufe, but compli- cated machinery is always liable to get out of order, and it may be difpenfed with here, if the obfervers be ever fo little expert and attentive. The motion of It might be fufpected, that the motion of the fir ft difk would the diflcs does cau(e feme deflection of the ball from its true path before it asihof die bail, reached the fecond. To afcertain this, three fcreens were fixed at equal diflances, the fecond and third being placed before the fix fl: and fecond difks refpectively. Now it is obvious, that the hole in the third fcreen would not be in the fame vertical plane with thofe made in the firft and fecond, if any deviation took place. Experimental A bail being fired through the apparatus thus arranged, a Prcot* plumb line was fufpended before the centre of the hole in the firft fcreen, and the mod accurate obfervation could not dif- cover any deviation, but that the fame line cut the centres of all the three holes. This experiment was feveral times re- peated with the fame event. This owing to The fact no doubt is, that the extreme fhortnefs of the time, the velocity. (for the femidiameter of the ball is not the forty thousandth part of a fecond palling the difk) does not allow the difk fenfibly to affect the path of the ball ; much lefs can the ball hava any effect on the motion of the difk. It may not be amifs to obferve, that the difiance of the far- theft fcreen being about twelve yards only, the inflexions ob- ierved by Robins in diflances of a hundred yards were not likely to take place. Fad. INVISIBLE EMISSION OF STEAM. 47 ' Futt concerning the invifible Emifjion of Steam into the Air* W. N. DOON after Mr. Giddy had mentioned to me the very re- Steam wasvi- markable and curious facts of which an account is given at acurrent; page I of the prefent Number, I was engaged in the experi- ments on the fimmering of water related at p. 216 of Vol. X. I then made an experiment which may perhaps in a (mall degree elucidate thofe phenomena. A fmall glafs tube was ftuck through a cork, and this was then preHTed into the neck of the retort in which water was boiling over the lamp. The fleam was emitted through this fmaller aperture in a vifible jet of upwards of a foot in length. But when a candle was held with its It became In- flame immediately beneath the end of the tube, the jet became V1^ ^" ^ perfectly invifible. To determine whether the water might flame of a be decompofed, or the (ream (imply expanded fo far as to becandle» abforbed by the air, or if condenfed to form a vapour too thin lo be perceived, I fufTered the hot invifible current which had patted through the candle, to pafs through a larger glafs tube. In butthefl-eara this cafe vifible fleam iffiied plentifully from the farther end : wj£dn.ot *<*"■• Hence, I am difpofed to judge that the large tube having kept the very hot fleam together and cooled it fo as to render it vifible again, there was little if any decomposition of the water. But at the fame time, when we confider the d i fa p- Perhaps fome pearance of the denfe fmoke in Mr. Giddy's experiment, there £art m»y have feems to be great reafon to think that the charcoal was oxi- genated and gazifled. If fo, the produces muft have been ex- panded and invifible fteam, hidrogen and carbonic acid. By collecting the products in an experiment of this kind, thefe conjectures will either be verified or refuted. If the former, we (hall have the decompofition of water and oxigenation of carbon at a lower temperature than has hitherto been fhewn or expected. Experiments -48 WATER BLOWING MACHINE. XI. Experiments made -with the Water blowing Machines of the Iron Works of Poullaouen ; by Citizens Beaunier and Gallois , Mine- Engineers *. Theetpen- OuR objeft was to ascertain the differences in denfity of ments made to ,..,.,, . J &ewthe eft'efts the air within a blowing machine, under the various circum- of a blowing fiances by which it might be affected; and at the fame time, we1 endeavoured to find what may be the moft advantageous mode of conftrucling the maehine, to produce the greatefl effect with the lead expenditure of water. Former accounts One of the chief caufes of the doubts that have arifen re- are obicurc fpecling the fuppreflion or retaining of certain arrangements in the conftruclion, was the omitting to defcribe the machines, the experiments with which have been compared. We fhaU therefore previoufiy notice the principal diftin&ions that may be made between thefe machines, from the manner in which their effect is produced. Two kinds of Dr- Lewis obferves, that there are two general methods of water blowing caufing the air to be conveyed by the water in the blowing: engines, as the , . T , _ , J . . ° air is received machines. In the nrtr, the water receives the air by the autop, or from fummit of the machine; in the fecond it receives it by lateral apertures : and he lays it down as a principle, that thole circumftances, which promote the effect in the one cafe, are detrimental to it in the other. General ob- **e Stewed further, that if the water be at reft in the fervations of funnel of the machine, (fee Plate III. Fig. 2.) and afterward The engine is ^ave hbertv to run off> it carries little or no air with it ; that an upright pipe if the water have a gyratory motion in the funnel, it carries t Jhoichr of iCh down a conruierable quantity ; and that if it fall from a cer- water and air tain height, fo as to have been greatly divided, it carries ffill defended. more . tha( jf the water flow through a pipe with lateral apertures, it receives air through thefe apertures, even when its motion is flow : that if the pipe be of equal diameter throughout, the quantity of air thus received is inconfiderable ; Lateral apertures but if the diameter be diminiflied to a certain degree at the admitdr!* the part wbere the aPertures are made, the quantity of air is air. greater than could have been introduced through the funnel * Tranflated from the Journal des Mines, No, 91, without Water blowing machine. ^a Without any lateral openings to the air: laftly he obferveSi that air conveyed downward from the top of the tube, or the funnel, prevents the introduction of the frefh air by the lateral apertures, which in this cafe, inftead of receiving more air, let that which has been already introduced efcape. Lewis concludes, that the two methods by which air may be made to defcend with a ltream of water, ought not to be united in one machine ; and that the machine confirucled with a pipe, a funnel, and apertures to let the air enter around or below the throat, produces the molt powerful efTea. The machine on which we made our experiments was of The machine of the conftruaion which Dr. Lewis has deemed moll advantage- J-™^** de~ ous. See Fig 2. The height of the fall, taken from the bottom of the channel Height of the that conveys the water to the upper part of the barrel B, is u ' 21 feet 6 inches. The height of the funnel, from the bottom of the fame Funne! at top channel to the throat x, is feven feet. This funnel is of the ofthiPPe- fhape of a frufrum of an inverted cone, the larger diameter / of which is J 2 inches, the fmaller four. The remainder of the tube down to the barrel, is a cylinder eight inches in diameter. The plank N, 12 or 13 inches wide, is fixed one foot Barrel or ait below the head of the barrel. The barrel is fix feet high. V( frd* The water iffues out of the barrel by the triangular apertures The wit r flow* 1 1 1, and is conveyed away to a drain by the channel M, the oft beneath > bottom of which is four feet higher than that of the barrel* The air comprefTed by the external water, the level of and the air \% which, as will foon be proved, is from 27 to 30 inches above c°nveyed that of the water in the barrel, efcapes through the tube P, it top. Which is a hollow cylinder five inches in diameter. This tube P, called alfo the air-pipe, terminates in a conical Air-holes in tb* nozzle, having an aperture of two inches only. upright pipe. Immediately below the throat x, are four air-holes y y. This being premifed, we proceed to the inftrument em- ployed by us for determining the denfity of the air in the machines. It was invented by Citizen Vergnies Bouifchere, pro-Gagef?* prietor of the iron works at Vic-Deifos, in the ci-devant ^nfity'of th* Vol. XII.*-Sjb.FTEMBJiR, 1805. £ county air. 50 WATER BLOWING MACHINE. It is a thort ba- rometer gage inferted, the fluid being water. county of Foix, and is a particular kind of barometer, to which the name of water anemometer has been given. See Fig. 6. " It is compofed, lft. of a cylinder A; 2d. of a tube c, bent twice, the lower extremity of which is flightly conical, and terminates about two inches below the bottom of the cylinder; 3d. of a graduated tube d inferted in a vertical pofition into the cylinder, and reaching below the level n of the water contained in it. The tube c being inferted into an auger hole made in the fide of the blowing machine, and flopping that hole clofely, the internal compreiled air communicates with the water con- tained in the anemometer, prefles upon it, and in proportion to its denlity raifes to a lefs or greater height in the graduated tube. The cylinder A and the tube c are of tin. The lower part of the tube d to the height of nine inches is of the fame ma- terial, to which is fitted a glafs tube about 36 inches long. The cylinder A is four inches high and as many in diameter. The greateft diameter of the curved tube is half an inch, the fmalleft, at the extremity, a third of an inch. On obferving however, that the fize of this opening contributed to increafe the extent of the ofcillations in the graduated tube, we en- deavoured to diminim it as much as poffible. For this purpofe we clofed the lower part of the tube v with fealing wax, in which we afterward made a very fmall aperture by paffing a heated needle through it. The tube d was divided by a fcale of inches, beginning from the furface of the water contained in the cylinder *. .Experiments X with the blowing .machine. ACCOUNT OF THE EXPERIMENTS. Experiments relative to the Expenditure of Water, and the Quantity of Air difengaged. The blowing machine No. 1, fee the horizontal proje&ion, Fig. 1 . to which for the fake of clearness we (hall refer our different experiments, ferved for the trial. It was placed in a T, oppofite the machine No. 2, deflined for the fame pur- * The great difference between the diameter of the tube d, and that of the cylinder A allows the level n to be confidered as con- stant. pofe. WATER BLOWING MACHINE. $\ pofe. The afflux of water into each was regulated by means of the hatches a and b, and the diftant floodgate Q, placed in the principal channel D. See the plan Fig. I. Plate . The anemometer was placed in o, Fig. 2, in the direction of the vertical tube P protracted. The hatch placed in b was let down, fo as to prevent the patTage of the water that way. The hatch placed in a was raifed, and the flow of water re- gulated by means of the floodgate Q. This flow we varied, till we found the water in the graduated tube raifed as high as could be effected without any other change of circumftance. When we were certain we had attained this point, and that no variation in the quantity of water flowing off took place, we made the following obfervations. 1. The mean depth of the water in C, in the little channel, Obfervations, juft before the T, was 15 inches 6 lines. 2. The mean depth of the water in the great channel, was 18 inches 9 lines. 3. The water rofe to 26 inches in the graduated tube. The ofcillations varied between 25 and 27 inches, but feldom reached the latter height. 4. The velocity of the wafer in the great channel having been obferved, the following data were obtained. Examined by means of Ample floaters of paper, on an extent of 24 feet, we had, lft. The fpace pafled through in two minutes = 61 feet, 8 inches, 6 lines. 2d. The fpace palled through in four minutes = 120 feet, 6 inches. The fame velocity examined with cork floats, fupporting Method of mea- little balls of wax, the weight of which was augmented by fujinS the bits of lead, fo that they fwam in the middle of the ftream water. with a gravity little exceeding that of water, we had for a irean of the fpace pafled in two minutes, 63 feet, 7 inches, 4 lines. If we compare thefe different refults, we (hall find, that the mean velocity of the water may be estimated at 30 feet, 4 1 inches, 1 line, a minute : but as it appears to us, that the refults afforded by the cork floats muft approach neareft the truth, we will pay no regard to the quantities before obtained, and eftimate the mean velocity of the water in the greater channel, at 31 feet, 9 inches, 8 lines, a minute, E 2 Now 52 WATER BLOWING MACHINE. Confumptlon of Now the breadth of the channel employed is 3 feet, 6 water. inches, and we obferved, that the current, the velocity of which we have given, is J 8 inches 9 lines deep. Hence we may conclude, that the confumption of water by the ma- chine, under the circumftances above mentioned, is 173 cubic feet in a minute, the height of the column of water in the inftrument being 26 inches. Quantity of air From the method defcribed in the Hydrodynamics of Boflut, emitted. we caIculated the quantity of air which this mafs of water caufes to ifTue from the machine in a given time. This quantity of air was found to be 7.35 cubic feet in a fecond, or 441 in minute *. II. Experiments on the Effect of the Air-Holes. Effe& of the 1. On (lopping the four air-holes, the water in the tube of air-holes afcer- tne jnftrument defcended to nine inches, and ofcillatcd very tamed by ex- . periment. little. The effiux of the water from the machine acquired a velocity fufficient to diminifh the depth of the water in the little channel C, Fig. 1 and 2, near the T, fix inches. 2. One of the air-holes being opened, the water in the tube ofcillated between 22 and 24? inches. The mean = 23 inches. 3. A fecond air-hole being opened, the mean height of the water in the tube was 25 inches. 4. A third air-hole being opened, the columns of water in the tube rofe to its former height of 26 inches. 5. The fourth hole being opened, no perceptible altera- tion in the inftrument took place, which proves, that this hole has no effect on the machine. III. Experiments on the life of Cmffes placed at the fuperior Orifice of the Machine, ther crofs Some iron-matters are accuftomed to place two round bars bars in the top *n the form of a crofs at the upper orifice of the funnel of the ofthetubete machine. Xhefe they imagine increafe the effeft of the machine by dividing the water at the moment of its fall. Cylindrical bel- * If tnefe ^^^ be compared with thofe of the cylindrical bel- lows of Namur lows of the country of Namur, defcribed by Cit. Bailbet, in No. 16*, give more air 0f the Journal des Mines, it will appear, that, to give out an equal with lefs water. quantjtv 0f a;r> the quantity of water expended by the blowing machines, with a fall more than twice its height, is nearly double that employed to move the cylindrical bellows. To WATER BLOWING MACHINE, 5$ To judge of this in the cafe before us, we fitted in one of thele crofles, all the other circumftances remaining as above, and then obferved the progrefs of the inftrument. The column of water in the tube frequently defcended toThey diminifh 24 inches, and feldom rofe to 26 : whence we may eftimatetlle *■&&* the mean height, which before was 26 inches, only 2 4-J. Now this difference occafions a diminution of velocity in the em\ix of the air, and confequently (hews the faultinefs of this method" under the circumftances here mentioned. IV. Experiments on the Effect of Hatches placed near the Orifice of the Machine. The hatch a Fig. 1. was replaced in the grooves adapted Advantage ^f to the channel. We altered its height from the bottom of the \nf{ux if water, channel, obferving the movements of the anemometer, in order to find the pofition moft favourable for the effect of the machine. The mean height of the column of water in the tube never exceeded 28 inches, the elevation of the lower part of the hatch above the bottom of the channel, being then five inches one line; and it is remarkable, that the difference of a tingle line in this elevation lowered the water in the tube confider- ably. V. Experiments on the Crojfes when the Hatch is ufed. The hatch being placed as has juft been faid, we, fitted the When thus re* crofs again at the fuperior aperture of the funnel, when the8 ed* water in the tube of the anemometer funk. We then varied the height of the hatch above the bottom of the channel, obferving the progrefs of the inftrument, to determine the moft advantageous pofition for it under the prefent circum- ftances. The elevation of five inches eight lines was now found The crofs pro* the moft favourable to the effea. With this the water ofcil-duced more air> lated in the tube between 28 and 30 inches, moft frequently reaching the latter height, which we could never bring it to exceed, whatever changes we made in the arrangement of the parts that compofe the machine. If we compare the fituatton of the hatch before the addition *>«* expended of the crofs, with that which is moft fuitable in the ca/e™ewate* before us, we find an increafe of feven lines in the height > • 2 from 5^» WATER BLOWING MACHINE. from the bottom of the channel: now this addition to the height confiderably increafes the quantity of water expended by the machine. Conclvfvms from thefe Experiments. Genera! cnnclu- (A.) Under the circumftances related in the firft fet of fions. The experiments, engine by 173 » cube feet fall- I. The expenditure of water for the blowing machine jng through 21 with which they were made was 173 cubic feet in a minute. feet, drove out J . 441 cubic feet 2. I he air emitted from the aperture of the nozzle, being of air in a (W0 inches in diameter, when the anemometer was at 26 minute, under a., .' , 1 • r , . preffureof >6 inc*hes, was 441 cubic feet in a minute. inches of water (B.) Of the four air-holes in the machine, three only con- cury; which is (C.) The hatch placed near the orifice of the machine in- not quite one creafed ;ts effe6l when lhe | p t f h raifed fi pound per fquare , » inch. inches one line above the bottom of the channel to which it was fitted. (D.) A crofs placed at the upper orifice of the machine diminifhes its effect when the hatch is taken away: on the contrary they increafe it, if the hatch be fo placed, as to be five inches eight lines above the bottom of the channel, an elevation greater than that mentioned in the preceding paragraph (C.) and which increafes the expenditure of water. From thefe refults it may be inferred, that the crofs mould not be ufed in feveral cafes, where the quantity of water with which the machine is fupplied, is confined within certain limits. ANNOTATION. W. N. The water blow- The blowing engine defcribed in the preceding memoir ing engine a^s upon tne principle of the lateral adhefion of fluids, upon farther explain- * r ' . ed. which Venturi has fo ably written, m a treatile given entire in our Quarto Series of this Journal, and feparately publifhed afterwards by Taylor in Holborn. The fliower of water in its defcent through the vertical pipe carries down a mafs of air along with it, in the fame manner as a fhower of rain on the flat furface of the fea produces that temporary blaft of wind, 3 which WATER BLOW TNG MACHINE.. v 55 which teamen term a fquall, and is fufficiently violent to carry- away tlie -mails of a (hip, if the fails be net reduced in time. It is evident that this engine poffelTes the defireable qualities of cheapnefs and fimplicity; and Lewis who has written fomewhat fully upon it, in his Piiilofophical Commerce of Arts, from experiments of his own, afferts, that it requires much lefs water for working it than any other kind of bellows in ufe. I have no doubt but that many occafions muft offer in which it would be beneficial; but whether its expence of water be comparatively finall, and its power in any cafe equal to the fupply of our fmeiting furnaces, may be deferving of more enquiry. In the excellent paper of Mr. Roebuck on the Devon iron Numerical works, inferred in the fifth Volume of the Edinburgh Tranf. ?Tatemenf b* & Mr. Roebuck, actions, and alfo in the Quarto Series of this Journal, there 6f the effect or a are fome numerical fads refpe&ing the blaft afforded to iron team engine in furnaces by iron cylinder bellows worked by the fleam engine ; 0f air, and as they agree very well with others given in my Chemical Dictionary, under the article Trompe, I will flate them in this place.;- Mr. Roebuck affirms, that one iron furnace was excited by a blowing cylinder, which gave 155 cubic feet of air 16 times per minute, which numbers give a product of 24-80 cubic feet. This is §\ times the quantity emitted by the blowing engine in the text. The fleam engine was efiimated to act by a preflure of 13062 lbs. anfwering to 2| lbs. on the fquare inch of the air piflon, and this multiplied by four feet eight inches, the length of ftroke, and by 16, the number of ilrokes, gives 975296/or the weight multiplied by its fall in feet. Now the machine in the text was worked by 173 cubic compared with kett or 10812 lbs. of water falling through 21 feet, which jjj SjJJjT gives a product of 227052, or mote than one fourth of the fii ft mover of the fleam engine blafl, inftead of one fifth and a half. The blowing engine therefore confumed more water by one fourth than would have been required to produce its effect, according to what was done' by the fleam engine But the fleam engine drove out its air under a reaction of between five and fix inches of mercury in the gage ; a velocity which being more than Mr. Roebuck found neceffary, was a difadvantageous wafle of power. The velocity of the The fteam water blowing engine produced by its preffure of two inches, "JJ" " m0rC is moll probably too fmal! ; and if fo, the multiplication of thefe 5(J VIBRATIONS OF A BALANCE. thefe engines would not be advifeable, even if Lewis had been in the right in fuppoiing them to fave water. Thefe rough computations, or rather eftimates, are fufhciently near for data (o look: as thofe upon which we have operated ; and they appear to (hew that the principal, and perhaps the only recommendation of the water engines is, that many of them may be made and applied at a fraall charge, in fituations where water with a proper fall is plentifully to be had. XII. A Method of rendering the long and jhort Vibrations of a Balance, governed by a Jpiral Spring, precifely equal in Duration. By Mr. Charles Young. In a Letter from the Inventor. To Mr. NICHOLSON. SIR, Wo explannt'on 1 HAVE lately tried many experiments upon fprings, with ha-j be™ given a vjevv f0 obtain fome knowledge of the caufes which govern why the l> ng ° ° and fh< tt v;bra- an effect that is very troublefome to all makers of chronome- fionsof a ba- ters . namelv, that the vibrations of the balance through Qiort Unci are difler- "\ . . . Mti arcs, confuting or perhaps ninety degrees, are in iome m- ftruments performed in longer) and in others in fhorter times than thofe long arcs, fuch as of four hundred. It is certain that no fatisfaclory reafons have been given, either in England or in France, to (how how this irregularity is pro- duced. A balance fuf- * made a piece of brafs to ferve as a large watch balance, pendid by a and fufpended it by a bit of fpring wire, on which it could /trait wire had vjDrate as an axjs then having turned it four or five times, jts bng znn \ >••! ihort vibrations I left it to regain its natural pofition*. It performed all its equal. * This method of fufpenfion has been ufed for philofephical purpofes, by Mr. Mitchell, (fee Prieftley's Optics,) hy Mr. Caven- dilh, (fee Philof. Tranf. and alfo this Journal quarto II. 44-6.) by Mr, Coulomb, in his numerous experiments on Electricity and Magnetifrn} and by Mr. Berthoud, in his Time Piece, No. 24. See his Tjcatife de la Meanire du Temps, p. 50. It does not appear that this fpring has yet heen ufed by itfelf in time pieces. N. ofcijlations VIBRATIONS OF A BALANCE. 5& ©fcillations precifely in equal times, whatever was their (J / extent, whether they confided of thirty degrees, or of three thoufand. It therefore returned to the place at which it was at reft with velocity exa&Iy proportioned to the fortes employ- ed to remove it. From this experiment I concluded, that the balance fpring of a watch is not in a fituation to exert this natural quality, but that the diftortion into which it is thrown, is fuch as deftroy this valuable property oi' ifochro- nifm. The principal circumftanee by which the fpiral balance The fpiral fpring fpring appears to me to be cramped, and prevented from " jcra™Ped by operating by its natural action throughout, is, that the outer extremity is fixed by the ftud, fo that it cannot expand and contract in its coils every where alike, as it ought to do. To but wIlen jts remedy this, I attached the ftud to a ftraight fpring, lying in made free by a the direction of the tangent of the fpiral, continued from that ftraight fpring extremity. This fpring by its eafy aftion allows the fpiral to jjj j^ff^** approach the centre, and retire from it with great regularity ; and, what is moft material, it can with certainty be reduced to fuch a ftrength, that the long and fhorl vibrations of the balance will prove perfectly equal when this adjuftment is made. For upon the ftrength of this fhort fpring depends the freedom with which the axis of the balance is enveloped ' by that fpring which regulates its motion. The fpring ftud affords a good banking ; for the banking pin on the balance may be eatily placed fo as to ftrike upon the end of the ftud in the cafe of extreme vibration. I am, Sir, Your's moft refpeft fully, CHARLES YOUNG, Wood Street, Aug. 23, 1 805. SCIENTIFIC 53- SCIENTIFIC NEWS. SCIENTIFIC NEWS. Compojition of Muriatic Acid. Letter on the IN (lie third number of the Edinburgh Medical and Surgical competition of journaj publi{hed July I la ft, is the tran'flation of a letter for- rounatic acid. J . warded to the editors of' that work by the celebrated Fabbroni. It bears date from Pifa, May 9, 1805, and rs written by Dr. Francifco Pacchioni, profeffor of natural philofopy in the uni- verfily of that city, to Sig. Lorenzo Pignotti. Water decom- After fome prefatory observations, the writer announces pofed by gal- ^at he has fucceeded by galvanifm in obtaining fatisfaclory evidence or the nature of the conttituent principles ot muri- atic acid. He expreffes his confidence that the fimplicity of his apparatus and means have fecured him againft iilulion; but for want of time he forbears to relate the whole feries of his experiments. His refults are, — thatmumtic ]. Muriatic acid is an oxide of hidrogen. 2. In the oxige- ©T hidrogen*.1 * nate<^ muriatic acid and therefore, a fortiori, in muriatic acid there is a much lefs proportion of oxigen than in water.' ". Hidrogen may have very many and different degrees of oxida* tion. Some account of The author informs us that having, by accurate experiments, the experiment. afcertained the true theory of galvanifm, he readily difcovered a very limple and exa6l apparatus, in which he could diftinclly perceive the changes which happen to water, which, from the continued action of the galvanic pile, is conltantly lofing its oxigen at the furfaceof a wire of very pure gold immerfed in it. Water deprived With this apparatus, which I conjecture mull have been of oxigen firft t}ie fame as that of Davy, in which the oxigen and hydrogen ' were given off in feparate veffels of water, he obferved that pure oxigen was emitted from the gold wire, that the water became acid, and when by proceeding in the operation until the refidual fluid occupied about half the capacity of the re- ceiver (that is, I prefume, when half the fluid in one of the veffels had difappeared) the remainder was found to be of an orange colour, more deep the lefs quantity of fluid. It re- — and then ap- fembled a folution of gold. From the lower orifice of the peared to have veffel, which was clofed with a piece of taffetas and then with diflblved partof ,,,,,,, r n i r i • • the gold wire. double bladder, a Imell was emitted of oxigenaled muriatic acid. The gold wire appeared corroded. The bit of taffetas which SCIENTIFIC NEWS. 59 which had been in contact with the coloured fluid had under- gone an action which rendered iteahly to be torn. Round the edges of the veflel on the bladder there was a deep purple ring and within that a circular fpace rendered colourlefs or white. A drop of the fluid itfelf tinged the fkin of the hand after fome hours, of a beautiful rofe colour. The fame liquid, pofTeffing conftantly the fam« qualities, Qualities of th« was obtained in various repetitions of the experiment. It was ftuc^tained fhewn to contain a volatile acid by the white vapours which rlatic acid, were formed by ammonia placed near it. It threw down a curdy precipitate from nitrate of filver, which the author con- cludes to have been the muriate of that metal ; and from the whole of the facls he deduces the refults firft enumerated at the beginnig of this abftract., reflecting the competition of muriatic acid from water by depriving it of part of its oxigen. He promifes to treat of the other oxides of hydrogen in a me- moir fhortly to appear. The origin and nature of the muriatic acid being thus, as Hence the origin the author obferves, determined, there is no longer any myftery °f the fa!t0* ^ in its formation, nor in that of the muriatic falls in the vaft ex^ tent of the ocean. The editors of the refpectable Journal, from which I have Acid and alkali made this extract take notice of the early difcovery of Cruick- °bfe.rv,ei! b^ . n i . i in i i i • r • r > i • Cruickihank in thank (publilned by him in our quarto feries tor 1801) that in- iSoitobeform* fufion of litmus was reddened by one end of the pile and in- ed by galvanifm, fufion of Brazil wood rendered purple by the other, which he afcribed to the formation of nitrous acid and ammonia ; and they a!fo quote the difcovery of muriatic acid being formed by —and common the galvanic action by Mr. Peele of Cambridge, which was fa,t by Peele m announced in Mr. Til loch's Philofophical Magazine a few days before Profeflbr Pacchioni's letter was publiflied at Pifa. Mr. qt mm\zts 0f j Peele's letter bears date April 23, 1805. He took a pint of foda. diftilled water and decompofed half of it by means of galvan- ifm ; the other half, being then evaporated, left a fmall quan- tity of muriate of foda or common fait. Great attention had been paid to the purity of the water; and upon a careful re- petition the fame refult was again had. In a poftfeript he men- tions that a friend of his had tried the experiment and fuc- ceeded in the fame manner. Literary 60 SCIENTIFIC NEWS, Literary and Pfiifof optical Society of Neivcajlle upon Tyne. Twelfth report THE Literary and Philofophical Society of Newcafile- Wt!^ndVkil.ftlC uPon-Tyne have published their twelfth year's report. The Society. fpirited union of" literature, fcience and practical refearch con- tinues to form the character of their proceedings. Their li- brary encreafes no Iefs in value than in magnitude, and they have liberally refolded " that the fubicribers to the public If. " brary at North Shields (and to other fimilar inftitutions which " (ball afford an equal accommodation to the members of the ° Newcaftle Society) (ball be admitted to the rooms without " introduction on producing to the librarian a certificate of w their being members of fuch inftitutions." I will not fup- pofe that any of my readers will confider this information as merely local. The advantages of provincial focieties of efti- mable and well informed men is of high national importance, and it cannot but be of general intereft that fuch enlightened proceedings as are adopted in one part of the kingdom fliould be known and imitated in every other quarter, where fimilar circum fiances may render them defirable. Blafting rocks in I have much pleafure in adding the tefiimony of Northum- ^^ ops berland in favour of the improvement in blafiing rocks, which Mr. JefTop communicated lafl: December, through the chan- nel of our Journal. *— tried *ith At* the meeting in April, 1S04<, Mr. Fogget of "Sheriff. ?mb'r]and!°rth" Hil1 reP<>rted, that the new mode of blading with fand, de- fcribed in the Philof. Journal had been tried by him, and that, contrary to his expectation, it had anfwered every purpofe of the old mode, with a confiderable faving of powder, and of more than one-third of the labour, and with an entire freedom from rifk. At the meeting in May, Mr. Fogget prefented a feclion of two holes drilled and prepared for blafiing according to the new method: One perpendicular, in wbich. the charge of powder being introduced and the cornmunication-firaw placed, , the remainder of the hole is filled up with fine dry fand : the other a horizontal or alcending hole; in which the powder and fand, being made up into a cartridge, is in the a£t of being thruft up to the fartheft extremity of the hole, by a blunt- pointed pricker put in by the fide of the communication ftravv. * Report, page 5. At SCIENTIFIC NEWS. 6\ At the meeting in June an account was communicated by ^ngcr,of,thJ Mr. Thornhill of an accident having happened in GateQiead- ramm-,ng j0wrt Park colliery, by which one man lott his life and another had the charge, been feverely wounded, in confequenee of the powder hav- ing taken fire in the common mode of ftemming, or ramming down the charge with fragments of ftone. A cafe was alio cited by Mr. Horn of a perfon who had lately been brought from Aifton Moor with his fkull fractured by a timilar ex- plofion. New Procefs for Steeping Hemp, THE new procefs of M. Bralle for fleeping hemp, which j^pIn^ has the advantage of faving time, capital, and the health of numerous individuals, and of which an account w7as given at page 86 of our laft volume, has been repeated in one of the provinces of France, to the entire (atisfaction of the inha- bitants, who might be fuppofed the leaft inclined to deviate from their accu itemed habits. The ftaple was found to be excellent, and of a fuperior flrength and quality when fpun into thread, and alfo after it had parted the loom in the form of cloth. Medical Theatre, St. Bartholomew's, Hofpital. THE following courfes of Lectures will be delivered at this theatre during the enfuing winter. On the theory and practice of medicine, by Dr. Roberts and Dr. Powell, On anatomy and phyfiology, by Mr. Abernethy. On the theory and practice of furgery, by Mr. Abernethy. On comparative anatomy and phyfiology, by Mr. Macartney. On chemiftry, by Dr. Edwards. On the materia medica, by Dr. Powell. Anatomical demonftrations and practical anatomy, by Mr. Lawrence. The anatomical lectures will begin on Tuefday, October 1 ft, at two o'clock, and the other ledtures on the fucceeding days of the fame week. Further particulars may be learned by applying to Mr. Nicholson, at the apothecary's (hop, St. Bartholomew's faofpital. AN 62 SCIENTIFIC NEWS. Medical Injlituiion. AN Inftitution has been lately eftablifhed in London for the purpofe of promoting a liberal and ufel'ul intercourfe among Ihe different branches of the medical profeffion, and of af- fording a centre for the reception of communications, and for the formation of a fele£i and extenfive profeffional library. It is called the Medical and Chirurgical Society of London, and it comprizes a confiderable number of profeffional men of the flrft character. The meetings (which will commence in October) will be held at the Society's apartments, Verulam- buildings, Gray's-Inn, where any communications, or dona- tions of books are requeued to be fent, directed to the fecre- taries. The following is a lift of the officers and council for the pre- fent year. PRESIDENT, Wm. Saunders, M.D.F.R.S. John Abernethyt Efq. F.R.S. Vtcc-Pres. Charles Rochemont Aikin, Efq. Sec. Wm. Babington, M.D. F.R.S. Vice-Pres. Matthew Baillie, M.D. F.R.S. Thou. Bateman, M.D. F.L.S. Gilbert Blane, M.D. F.R.S. Sir Wm. Blizqrd, F.R S. Vice-Pres. John Cooke, M.D. F.A.S. Vice-Pres. Afiley Cooper, Efq. F.R.S. Treas. James Curry, M.D. F.A.S. Sir Walter Earquhar, Bart. M.D. Tho'mpjbn Forftert Efq. Algernon Erampton, M.D. John Heavifide, Efq. F.R.S. Alex. Marcet, M.D. For. Sec. David Pitcairne, M.D. F.R.S. lien. Revell Reynolds, M.D. F.R.S. II. Eeigh Thomasy Efq. James Wilfon, Efq. F.R.S. John Yclloly, M.D. Sec. Properties SCIENTIFIC NEWS. (J3 Properties of blued Steel not generally known. ' IN making fprin£s of fteel the metal is drawn or hammered Mcth°d °f »**« out and fafhioned to the defired figure. It is then hardened by ignition to a low red heat and plunging it in water, which renders it quite brittle. And laftly, it is tempered either by Hardening, blazing or blueing. The operation of blazing confifts in ^^gmm freearing the article with oil or fat, and then heating it till thick vapours are emitted and burn off with a blaze. I fup- pofe this temperature to be nearly the fame as that of boiling mercury, which is generally reckoned to be at the 600° of Fahrenheit, though, for reafons I (hall in future mention, I think this point requires to be examined. The operation of blueing confifts in firft brightening the furface of the fteel, and then expofing it to the regulated heat of a plate of metal or a charcoal fire, or the flame of a lamp until the furface acquires a blue colour by oxidation. The remarkable facls which I A blue fpring; have here to prefent to the notice of philofophers are that Mr. brightening an' pands more by that hard fteel is more expanfible by heat than foft. heau It is very difficult to reafon or even to conjecture upon thefe fa&s. They certainly deferve to be verified by a direct procefs of examination, which I intend to make, and (hali ftate the refults in our next number. N. * See his banking far time p:eces in our XI. Vol* page 114. Cor- fi£ sfclfcNTIFIC NEWS. Prefervation of Succulent Plants. Whether (lie facl be generally in pofleflion of the collectors of plants I know not, but it will certainly be inftruclive to many readers to be informed that green fucculent plants are much better preferved after a momentary immerfion in boiling water than otherwife. This treatment, which I am told is adopted for the economical prefervation of cabbage and other plants which are dried for keeping, deftroys the vegetable life at once, and feems to prevent an after procefs of decay or mortification, by which the plant would have been more con- fiderably changed, if it had not been ib fuddenly killed. Corrections to the 1 \th Volume. P. 1 59, I. 2, area r. era. — 1. 2 1 , Agy r. Acjy. — 1 .36, qxp—2* r# qJ^-p — <2n. — 1. 12, for r. of. — 1. 23, put a comma before that. — p. 2.36, 1. 20 from the bottom, after the words preferved a* add as perfecl as poffible, but the prefs recommended by Dr. Withering does not appear calculated, fyc. — Dr. BoftocVs eflay upon animal fluids which was communi- cated by the author and inferted in our laft number, appeared alfo in the third number of (he Edinburgh Medical and Surgical Journal. This by a cafual omiffion of the friend who for- warded me manufcript was not intimated to me until fevs- jaldays after the paper came to hand. TfiihoUonbThaLos. Journal . Yol^HJ%r.pi?4 '-• ( >//Vx JtiyOWV Off m * TfidwlSOIVS l'luL<,s:.loun,al.\-<>l. XII. I'l . .!.//. 6A u name /-./ fib • A> // r/ "//, tit v • ,> 6 _ &u/uw tu >/ '■ ViohoUmut Fhiloj.JownaL.YdlJSJI.FU t.p t>4- B..J — f. _ ////// ,v fitt. ffia/&L //////>.) y- Ltit..__vJi ZE gg?: EH71 - a : ft^ i?sr »"i *E?6 7^/7. 7. »PJ. ij-"~-flii-"fr---"fir{= .»• .i;-.f?i.i.\-st/ ex- ; in • ft A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND a ■ 1 "', THE ARTS. OCTOBER, 1805. ARTICLE I. Experimental Jnvcjligations concerning Heat, By Benjamin- Count of Rum ford, V. P.R.S. Foreign Ajfociale of the National Inftitute of France, tyc. fyc. Received from the Author, To Mr. NICHOLSON. Dear Sir, Munich, Augufi 29, 1 8 05. AaAVING learned by a letter which I received this day from England, that you have publifhed in your Journal of Natural Philofophy the memoir I fent you on the temperature at which the denfity of water is a maximum, 1 take the liberty to fend you herewith inclofed three memoirs on heat, which are def- tined to appear in the next volume of the publications of the firft claf's of the National Inftitute. — Three other memoirs of mine will appear in that volume, but as they contain little that would be new to you, I do not fend them to you. I continue my refearches on heat, and have lately made fe- veral new and very interefting experiments, the remits of which it is my intention to communicate to you, as foon as I fhall have compleated the particular courfe of experiments in which I am now engaged. I am, Dear Sir, with much efteem, Your moft obedient fervanf, RUMFORD. Vol. XII.— October, 1805. F Sect. 66 ON HI! AT. Sect. I. Short Account of a new Experiment on Heat. I have lately made a new experiment, the refult of which appears to me fuiliciently interefting to deferve the attention of the cla(#. Qa. Whether * Having found by experiments often repeated that metallic the heating and bodies Cxpofed in the free air of a large apartment are much ed°an' are clean and P0,imed» 1 was curIous t0 ^now whether fpacesasinfpaces the fame phenomena would take place when, inftead of ex- more enlarged ? p0fing t}iere bodies in the open air* they mould be placed in clofe metallic veflels furrounded by a certain thicknefs of in* eluded air, and thefe vefTels fhould be then plunged in a large a mafs of hot or cold water. In ojjjjer to clear up this impor- t tant point, I made the following experiment: A cylindrical A cylindrical veffel of brafs, three inches in diameter and veffel of thin, four inches long was enclofed in another larger cylindrical vef- portetTin the ^e'» m lne centre of which it was fufpended by its neck, fo as middle of a larger to touch it in no other part, leaving on all fides an interval of ta«'A" * . one inch belween 'he veffels- ter4l or* air be- The external veffel as well as the fmaller one included with- tween them. jn jt js mac[e 5^ fj1jn Qieets of brafs: its diameter is five inches and its height fix. It is one inch and a half in diameter and fix inches high. Its neck is one inch and a quarter in diame- ter and two. inches and a "half long. The interior veffei isfufpended in the centre of the externa! one by a ftopper of cork: This flop per is adjufted to the neck of the external veilei, and there is a cylindrical hole of three quarters of an inch diameter through the cork, and having the fame axis, which perforation receives the neck of the interior veffel and retains it in its place. The interior veffel was introduced and fixed in its place be- fore the bottom of the exterior veiiel was (bldered in. The larger veffel - At the centre of the bottom of the great veflel is a fmall me- was fupported tallic tube of three quarters of an inch diameter and one inch oa a foot. , J , '-' . r ...... _ . . . and a half long, by means or which this inftrument is attached to a folid heavy foot of metal which fupports it in a vertical pofition when the whole inftrument is fubmerged in a veffel of water. This inftrument, which greatly refembles that defcribed in my 7 th effay on the propagation of heat in fluids, which I have called ON HEA,T\ 61 called the Paflage Thermometer*, may be ufed to make a number of interefting experiments on the cooling of bodies through different fluids. In the prefent experiment I em- ployed it in the following manner: The interior veflel was entirely filled with hot water to the Jhe inner vef- ... rii/* .... , . ,, A id was filled height of half an inch in its neck, and a good thermometer, with hot water, having its cylindric bulb four inches long, was inferted therein, and a thermo- The inftrument was then plunged in a mixture of pounded ice ^neck!06 and water, and the time was noted by means of the thermo- The whole in- meter, during which the hot water in the fmall. veflel became f^pTun^d in cold. •• '• ice andjwater. I was careful to plunge the inftrument in this frigorific mixture, fo that the large veflel was completely fubmerged except the upper extremity of its neck ; and I added from time to time a fufficient quantity of pounded ice, to keep the |» frigorific mixture conftantly and throughout at the temperature of melting ice. The following were the refults afforded by two fimilar in- # « § ftruments employed at the fame time : Thefe two inftruments, which I fliall diflinguifh refpectively Rc/vks w'th by the letters A and B, are of the fame form and dirnenfions j one 0f ^hich there is no difference between them but in the (rate of their B, had the itite- furfaces. In the inftrument A, the exterior furface of the ^ ^ItLl fmall veflel and the interior furface of the great veHfel which and the exterior inclofes it, are bright and polifhed ; but in the inftrument B, J^*/™"" the exterior furface of the fmall veflel and the interior furface the other inftru- of the large veflel are black, having been blackened over the ,nent» A> h*d n c ii i <• i i r i - , the like furfaces flame ot a candle before the bottom of the great veflel was poiimed. foldered in its place. Having filled the interior veffel of each of thefe inftrument* The interior with boiling water till the water rote to the height of half an toU^g watet^ inch in the neck, I placed a thermometer in each, and then plunging both infiruments at the fame time into a tub filled with cold water mixed with pounded ice, I obferved the courfe of their refrigeration during feveral hours. Each of the inftruments was completely fubmerged in the The refrige-at- frigorific mixture, excepting about one inch of the fuperior in.8 v^el con* . . . \ F , ° . _ r tamed lee and extremity ot tbe neck of the exterior veflel, and I was careful water. * See our Journal Vol. IX. F2 to 01 Caution to in- fure equality of temperature. Method ofipb- femtion. Table of the courfe of cool- ing. ON HEAT. to add new quantifies of pounded ice from time to time, in order to keep the frigorific mixture conftantly at the precife temperature of melting ice. As the fpecinc gravity of water at the temperature of three or four decrees of the thermometer of Reaumur, is greater than that of melting ice, the water which lies at the bottom of a veflel Containing a mixture of water and pounded ice, is ufually warmer than the fluid which occupies the upper part of the veflel. To remedy this inconvenience my refri- geratory for the frigorific mixture was a tin veflel fupported on three feet of one inch in, length, and I placed this firft veflel in a larger of wood, containing a certain quantity of ice furrounding the bottom and part of the fides of the metallic veflel. . .^ As in the firft moments of the experiment the thermometers defcended too quickly to be obferved with precifion, I waited till each of them had arrived at the 55th degree of Reaumur; after which I carefully obferved the number of minutes and fe- COnds employed in pafling through each interval of five de- grees of the lower part of the fcaie of the thermometer to the filth degree above zero. The following table exhibits the depreflion of the thermo- meters during eight hours employed in the experiment. Degrees of the Ther- mometer* From 55 to 50 50 45 40 35 30 25 20 15 10 45 40 35 30 25 20 15 10 Time employed in cooling 7 from 55Q to 5°, j Time employed in cooling, By the Intern- ment A. By the lnftru. ment B. llm 6* 7m 50, 13 15 - 8 10 \5 12 9 5 19 ,10 10 50 22 24 12 18 27**50^ 15 10 37 6 21 15 54 15 - 28 15 80 25 ' - 41 25 183 45$ - 85 15 478 254 It mean tempera, ture more cor- ON HEAT. ()9 It is evident from the remits of this experiment, that the Tne blackened blackened body is conftantly cooled in let's time than the po- cook/more Jithed body ; but it appears by the courfe of the thermometers, quickly than the that the difference between the quick nefs of cooling of thefe ot er' two bodies varies, and that this difference was lefs confider- able in proportion as the temperature of the bodies was more elevated in comparifon to that of the medium in which they were expofed to cool. In cooling from the 55th degree to the 50th above the tern- The difference perature of the furrounding medium, the poltmed, body em- ^ loweft tem- ployed 1 lm 6s, and the blackened body employed 7ni 50s to peratures ; pro- pafs through the fame interval. But from the 10th to the 15th b*h}? becaufethe r ° 4 • thermo.neters degree above the temperature of the medium, the poliflied then mewed the body employed 183m 45% while the blackened body employed only S5ra 15s; but it is extremely probable that this difference redly, between the proportion of the times employed in cooling the two bodies at different temperatures, is only apparent, and that it depends on the greater or lefs time required for the thermometers in the veffels to arrive at the mean temperatures of the maffes of water which furround them. ■ ** In order to compare the refults of this experiment with thofe From thefe ex- I made laft year with metallic veffels poliflied and blackened, Perimen5s * ap- J ... . Pears *hat the and left to cool in the undifturbed air of a large chamber, it rate of cooling is neceffary to afcertain how much time the two bodies in J" the Pr)llflie£l queftion employed in cooling, from the 50th to the 40th de- with the other, gree of Fahrenheit above the temperature of the medium. ls nearly the Now I found by obfervation, that the polilhed veffel A egj-mer]y deter. ployed 391* 30s to pafs over that interval of cooling, while the mined with bo- biackened velTel B employed only 22m. Thefe times are in chamber **** the proportion of 10000 to 5810. "By one of my experiments made laft year, I found that the times employed in paffing through the fame interval of cooling in the o,pen air by a clean poliflied metallic veffel, and another of the fame form and Capacity, but blackened without, were as 10000 to 5654. Reflecting on the confequences which ought to remit from If the intenfitles the radiations of bddies, on the fuppofition thA trfc tempera- ^ ifvtfel ^f tures of bodies are a»vays changing by means of thefe radia- the fquaresof tions, I was led to the following conclufion : If the intenfity ^'^nces, ° ■* bodies will cool of the aclion of the rays which proceed from a body, be uni-in the fame time verfally as the fquares of the diftances of bodies inverfely, ina" enclofure J ^ . . . of the fame tern- 3 which 70 ON HEAT. perature, whe- which is extremely probable, a hot body expofed to cool in a foalfcrT C c^e place, or Cur rounded on all fides by walls, ought to cool with the tame celerity, or in the lame time, whatever may be the magnitude of this enclofure, provided the temperature of Thcfefaflscon- fae flcjes or vva|js bc at a conftant given temperature; and the firm that truth 5 «r . ,. , , , &. ., , ! ,.,,,, reiuKs ot the experiment here delcribed, in which the hot body was enclofed in a veflel of a few inches diameter, com- pared with thofe of feveral experiments made laft year, in which the heated bodies expofed to cool between the walls of a large-chamber, appear to confirm this conclufion. and that the air As to lne effe^ placed bf the air in cooling a heated body expofed to cool in a clofe place filled with that fluid, I have reafon to believe that it is much lefs confiderable than has been fuppofed. Former experi- I have (hewn by direct and conclusive experiments, that that lVrTcdves Doc^es co°l ar)d are heated, and that with confiderable cele- oniy 1.27th rity, when placed in a fpace void of air * ; and, by experi- pdrt* ments made laft year with the intention of clearing up this point, I Found reafons to conclude, that when a hot body cools in tranquil air not agitated by winds, one twenty-feventh only of the heat loft by this body (or to (peak more coreclly, which it excites in furrounding bodies) is communicated to The reft partes the air, all the reft being carried to a diftance through the y u ja ion. &.^ ^^ communicated by radiation to the furrounding folid bodies. m .-* *.. Sect. II. Experiments on cooling Bodies, It is only by careful obfervation of the phenomena which accompany the heating and cooling of bodies, that we can hope to acquire exact notions of the nature of heat and its manner of acting. \ ^ M< Condufting Many experiments have been made by different perfons at witlhre^ardto8 different times, with a view to determine what has been heat. called the conducting quality of different fubftances with re- gard to heat: I have myfelf made a confiderable number; and it is from their refults, often no lefs unexpected than in- terefting, that I have been gradually led to adopt the opinions on the nature of heat which I h^e prefumed to fubmit to the judgment of this illuftrious aflembly. The flattering attention * See my Memoir on Heat in the Philofophical Tranfa&ions for 1786, and in my eighth Eflfay. with ON HEAT. 71 with which ihe Oafs has honoured the three Memoirs I have lately preferred, encourages me to communicate the conti- nuation of my refearches. All philofophers are agreed in confidering glafs as one of Glafs is allowed the worft conductors of heat which exifis; and when it i Cor ft conduct propofed to confine the heat in a body of which the temitors. perature has been railed, or to hinder its diffipafion as much as poffible, care is taken to furround the heated body with fubftances known to be bad conductors of ..heat. The refults of many of my experiments having led me to fuf- Bodies are not, pea that the cooling' of bodies-, is not effected in the manner Jrobab'y,«c.oole(i r ™ • by conducting which is generally fuppofed, I. made the following experi-off. ment with the intention of clearing up this interefting part of the fcience. .* I procured two bottles nearly cylindrical, of the fame formExp™™™*1 and the fame dimenfions when meafured externally; one be- bottl^ahd a thin ing of glafs and very thick, and the other of tin or tinned iron, one gf tin, which was very thin. Each of them is three inches ten lines in diameter very nearly, and five inches in height, and each has a neck one inch three lines in diameter, and one inch two lines in height. The glafs bottle weighs 13 ounces 1 gros and J 8 grains poids de marc, and the other thin metallic vef- fcl weighs only 5 ounces J gros and 65 grains. Having very exactly weighed the bottle of tinned iron, I were prepared, found its exterior furface to be 54,462 inches, which give weighed, 0,21 142 of a line for the thicknefs of its fides, taking the fpe- cific gravity of the metal at 7,8404. The mean thicknefs of Ihe tides of the glafs bottle is more and meafured. than fix times as great, as may be ealily deduced from a calcu- lation founded on the weight of the bottle, the quantity of its furface, and the fpecific gravity of glafs. I Having filled thefe two bottles with boiling water, I hung They were filled, them up by {lender firings in the midft of the tranquil air of a ™f ^^JS" large chamber, at the height of five feet from the floor, and in the air. at the diftance of four feet afunder. The temperature of the air of the chamber, which did not vary a quarter of a degree during the whole time of the expe- riment, was 9| degrees of Reaumur's fcale. An excellent mercurial thermometer, with a cylindrical bulb, of four inches long and two lines and a half in diameter, fufpended in the axjs of each of thefe bottles, indicated the temperature 72 ON HEAT. temperature of the contained water; and the time employed in its cooling for every five degrees of Fahrenheit's thermo- meter, was carefully obferved during eight hours. The glafs being confidered as a very bad conductor of heat, and the tides of the bottle being fo thick, who would not have expected that the water in this bottle would have been more ilowly cooled than that in the very thin bottle of tin. The glafs bottle The contrary however was the event ; the bottle of glafs quick aTtW vvas cooIed almoft twice as quickly as that of tin. tin. While the water included in the bottle of tinned iron em- ployed 56 minutes to pafs through a certain interval of cooling, namely through ten degrees, between the 50th and 40th de- gree of the thermometer of Fahrenheit above the temperature of the air of the chamber, the water in the glafs bottle em- ployed only 30 minutes for the fame change. Inference. It appears to me, that the refult of this experiment throws great light on the myfterious operation of the communication of' heat. Heat is not If we admit the hypothecs that hot bodies are cooled, not material fub- ^y lofing or acquiring fome material fubftance, but by the itance. action of colder furrounding bodies, communicated by undu- lations or radiations excited in an etherial fluid, the refults of this experiment may be- eaiily explained ; but if this hypo- thecs be not adopted, I cannot explain them. Bodies are not it might perhaps be fufpected that the air attached by a furrounding air. Gerta'n attraction, but with unequal forces, to the furfaces of the two bottles, might have been the caufe of this remarkable difference in the time of their cooling ; but thofe who will take the trouble to reflect attentively on the refults of the experi- ments I have defcribed in a preceding memoir, which were made with a view to clear up this point, with a metallic veilel firfl naked, and afterwards with one, two, four and five coat- ings of varnith, will be perfuaded that this caufe is not fuffi- cient to explain the facts. AH metallic vef- By a courfe of experiments made at Munich lafl year, of famedi'fpofiUon which the. details are given in a Memoir fent to the Royal to cool. Society of London *, I have found that a given quantity of hot water included in a metallic veflel of a given form and capacity, always cools with the fame quicknefs in the air, * See our Journal, Vol. IX. p. 194. whatever ON HEAT. 73 whatever may be the metal employed to conftruct the veflel ; provided always that the external furface of the veflel be very clean, and the temperature of the air the fame. In order that the cooling fliall be effected in the fame time, The furface only nothing more is required than that the external furface of the veflel be truly metallic, and not covered with oxi4e or other foreign bodies. On the enquiry, what quality all the metals might have in This arifes from common, and poflefs in the fame degree, to which this re- ^g^801^ ot markable equality of their fufceptibility of cooling might be attributed, I found it in their opacify. The rays which cannot pene rate the furface of a body, by which the muft neceflarily be thrown back or reflected ; and as the rays ea lsre e of light, which have much analogy with the inviflble calo- rific or frigorific rays, eafily penetrate glafs, though they are reflected, at lead for the greateit part, by metallic fur- faces, I fufpecled beforehand the refult of the experiment with the two bottles, one of glafs and the other of tinned iron. A^ The ftate of a heated body, or a body which contains a Ufual comparl- certain quantity of caloric, has been compared to that of 'a. ^" °r .^ to fponge which contains a certain quantity of water. Sup- fponge. poling this comparifon to be juft, we might compare the lofs of heat by the emiffion of the calorific rays, to the lofs of water by evaporation. Let us try if this comparifon can fup- ply us with the means of throwing fome light on the interefting iubject of our researches. Inftead of the fponge filled with w^ater, let us fubititute The fame am- the earth, and fuppofe for a moment that the earth is every pi where equally heated, and its furface in all parts covered with a bed of the fame kind of foil equally moid. As a fquare league in a mountainous country contains more If it were true, furface or more fuperlicial acres than a fquare league fitualed wou?d emhmoxe in the plain, it is evident that more water would be evaporated heat than a from the whole furface of the earth in a given time^f the earth fmoochone« were covered with mountains, than if its furface were an im- menfe plain, and coniequently, that more caloric ought to be projected from the furface of any folid body broken with afpe- rites, than from the furface of another body of the fame form and dimeniions, which is fmooth or well polilhed. This 74 ON HEAT. But the fafts This reafoning appears to me to be juft, and if I am not are contrary. j • j i deceived, (lie conclufions which may be drawn from the facts in queftion, well confirmed by experiment, ought to be conli- dered as demon ftrative. I have taken every poffible care to eftabiifh thefe fads; and the refullsof all my experiments have conilantly (hewn that more or lefs perfect polith, or the greater or lefs brightnefs of the furface of a metallic veflfel, does not fenfibly influence the time of its cooling. A policed and I took two equal veflels of brafj arid polillied the external Jtiot'btrsc^ed furfacc of onc oi them as hiKh*y as P^^ble ; and I deflroyed in the fame time the polifli of the other by rubbing it 'in all directions with coarfe emery. When thefe two veflels were filled with hot water, I did run jinci that the unpoliflied yefTfci employed more or lefs time in cooling than that which waa polillied. Ciution. I was careful to wafh the furface of the unpoliflied velTel effectually with water before the experiment; as I knew that if I did not take the precaution of removing all the dirt which might be lodged in theafperites of (he furface, theprefence of thefe fmall foreign bodies would influence the refult of the ex- periment in a fenfible manner. A rough furface We ought carefully to diitinguifh thofe furfaces which appear may re tk a as unpoijftie(] to our eves but which in facl are not fo, from thofe much light as a \ •> ' imocther. which reflect little or no light. Metals not lefs It is more than probable that the furface of a metal is always [ofin durable, and little inferior to (hat on iron; but nickel become* ilfelf magnetieal, or acquires polarity, by the touch, and even in pari by finking it with a hammer, or filing it, with the pre- cautions fuitable for producing this eflreft. I difcovered the latter property by prefenting to the magnet a flip of forged nickel; when, notwithstanding it was poliflied by the file, it adhered more feebly to the magnet than other flips lefs poliflied ; but on my prefenting its other extremity to the magnet, it ad- hered to it with great force. It likewife attracted by either fide not only iron needle^ but plates of nickel half arUnch fquare, which it raufed to move about on a fmooth fable. The property which nickel poflefles of becoming magnetic Its magnetic ,/-.-, , , ., , . . Ui<# • , property weak- . is not deftrOyed, though weakened by its alloy with copper; ened by copper, but arfenic deftroys it completely. I had frequent opportuni- deftroyed by ties of making this obfervation in the courfe of my experiments. Magnetic and Some nickel, from which I had feparated the iron * and the malleable in Pro- arfenic in the humid wav, and which I had afterwards reduced porUon Co lts - ' purity» with the addition of a combufiible fubflance, was malleable, and attracted the magnet, though not fo forcibly as pure nickel. The fame metal, purified with lefs care, was lefs malleable, and proportionally lefs attractable by the magnet. Repeated expofure of the metal to the mod powerful heat of a porce- lain furnace did not in the ieaft reftore to' i t this property. — Some experiments, which I (hall hereafter relate, have con- Copper muft be vinced me, that copper cannot be entirely feparated from *5Parated by nickel in the humid way, and that the only means of feparat- ing them is to reduce the cupreous oxide of nickel by fire. The Tulphuric and muriatic acids have little action upon AcVionof the nickel. The oxide of this metal by the air does nqgdiflblve ^j^*011 even in the latter of thefe acids without the afliftance of a ftrong ebullition. The mod appropriate folvents of nickel are the nitric and nitro-muriatic acids. I have already mentioned, that impure nickel, particularly the cupreous is attacked by the nitric acid with heat and vivacity. The action of the fame acid on pure nickel is a little different, and particularly on the * The feparation of the iron fucceeds beft by a rapid evaporation Beit rst>de of of the nitric folution of the ferruginous nickel, by which the iron freeing it from k precipitated in the form of an inlbluble oxide. At the fame time U< ».* a little arfenic is feparated in union with the iron. It is preferable, however, to feparate the arfenic firft, which is cffe&ed by the help of a nitric folution of lead. The lead is afterward to be precipi- tated by a folution of fulphate of potafli. hammered so ON PURE NICKEti Characters of ieht. hammered metal. I have poured nitric acid on nickel both in buttons and laminated, expecting a very acVive folution; but it has proceeded flowly, and I have even been obliged to havei recourfe to the heat of a fpirit lamp to accelerate it. Thedif- foiution however having appeared to ceafe, I decanted the liquid and poured on the refiduum a frefh quantity of acid of the fame ftrength as the preceding, when on a fudden fuch a brilk action came on, accompanied with the evolution of heat *, that I could not remove the capfule to the fire-place quickly enough, 6 I (hall now go on to confider fome of the characters of pure nickel in the (late of oxidation. The nitric folution of pure nickel has a beautiful grafs-green oxide ot nickfcl. cojour> Carbonate of potafii feparates from it a pale apple Precipitate very greei'P^ recipkate. This precipitate well wathed and dried is ve'ri^i* t. A thoufand parts of metallic nickel reduced to this pre'eipfrtate weigh 2,927 parts. If this precipitate be expofed to a white heat it becomes of a blackith gray, fcarcely inclining to green, and weighing only 1,285. On continuing the fire, the mafs approaches the metallic ftate more and more, and becomes magnetic. This is effected much more fpeedily if the oxide be moiftened with a little oil. # On adding cauftic ammonia In excels to a nitric folution of nickel, a precipitate is formed, refembling in colour ammoni- ure of copper, but not fo deep. This colour fometimes changes in a couple of hours to an amethyft red, and to a vi- olet, which colours are concerted into an apple-green on the addition of an acid, and again to a blue and violet on the ad- dition of ammonia. If however we add to the folution of nickel a folution of copper, fo as to produce no perceptible change, the colour of the precipitate formed by ammonia ceafes to atTumea red tinge, and the red colour of the ammo- niure of nickel difappears on the addition of a little ammoni- ure of copper ; whence it follows, that every precipitate of nickel by ammonia, which retains its blue colour, has copper combined with it. Oil promotes its reduction. Precipitate by ammonia. Irs being a noble * From this it Is difficult to believe that nickel, under favour- cuaal ^ucition- able circumftances, would not become oxided by the combined in- ei* fluenceof air and fire. Van Mons, On ANALYSIS OF SOILS. 81 in. On the Analyfis of Soils, as connected wiih their Improvement. £y Humphrey Davy, Efq. F. R. S. ProfeJf>r ofChemiftry to the Board of Agriculture and to the Royal Injlitution. I. Utility of Inveftigation relating to the Analyfis of Soils. A HE methods of improving lands are immediately connected with the knowledge of the chemical nature of foils, and ex- periments on their competition appear capable of many ufeful applications. The importance of this fubject has been already felt by fome Analyfis of very able cultivators of fcience ; many ufeful facts and obfer- to by' Mr> vations with regard to it have been furniihed by Mr. Y ang; Young, Lord it has been examined by Lord Dundonald, in his Te on ^k™L™A the connexion of Chemiftry with Agriculture, and by Mr. Kirwan in his excellent eflfay on Manures : but the enquiry is (till far from being exhaufted, and new methods of elucidating it are almoft continually offered, in confequence of the rapid progrels of chemical difcovery. In the following pages I mall have the honour of laying before the Board, an account of thofe methods of analyfing foils which appear mod prectfe and fimple, and mod likely to to be ufeful to the practical farmer ; they are founded partly upon the labours of the gentlemen, whofe names have been juft mentioned, and partly apon fome later improvements. II. Of the Subjiances found in Soils. The fubftances which are found in foils, are certain mixtures Soils contain or combinations of fome of the primitive earths, animal and ^rdthvs' ™JJ£ vegetable matter in a decompofing ftate, certain faline com- remains, faKne pounds, and the oxide of iron. Thefe bodies always retain *<™P°*"**, and * J oxide of iron, water, and exift in very different proportions in different lands ; and the end of analytical experiments is the detection of their quantities and mode of union. The earths found in common foils are principally filex or the earth of flints, alumine or the pure matter of clay, lime, or calcareous earth, and magnefia. Silex, or the earth of flints, when perfectly pure, appears in Silex, ; the form of a white powder, which is incombuftible, infufible, Vol. XII.— October, 18Q5. G intoluble 82 .ANAtflTSIS OF SOILS. infolublein water, and not acted upon by common acids; It is the fubftance which conftitutes the principal part of rock chryftal ; it compofes a confiderable.part of hard gravelly foils, of hard -Tandy foils, and of hard ftony lands. Alum'mc* Alumint, or pure clay, in its perfe6t ftate is white like filex ; it adheres ftrongly to the tongue, is incombuftible, infoluble in water, but foluble in acids, and in fixed alkaline menftrua.- It abounds moft in clayey foils and clayey loams ; but even in the fmalleft particles of thefe foils it is ufually united to filex and oxide of iron. Lime. Lime is the fubftance well known in its pure ftate under the name of quicklime. It always exifts in foils in combination, and that principally with fixed air or carbonic acid, when it is called carbonate of lime ; a., fubftance which in the moil com- pact form conftitutes marble, and in its loofer form chalk. Lime, when combined with fulphuric acid (oil of vitriol), pro- duces fulphate of lime (gypfum), and with phofphoric acid, phofphate of lime. The carbonate of lime, mixed with other Tub fiances, compofes chalky Toils and marles, and it is found in Toft fandy foils. Magnefia, Magnefia, when pure, appears as white, and in a lighter powder, than any of the other earths ; it is foluble in acid, but not in alkaline menflrua;, jt. is rarely found in foils; when it does exift, it is either in combination with carbonic acid, or with filex and alumine. Animal decom- Animal decompojlng matter exifts in very different ftates, ac- pofing matter. COrding as the fubftances from which it is produced are differ- ent; it contains much carbonaceous fubftance, and may be principally reiblved by heat into this fubftance> volatile alkali, inflammable aeriform products, and carbonic acid ; it is prin- cipally found in lands that have been lately manured. Vegetable de- Vegetable decompofing matter is likewife very various in kind, compdfihg mat- it contains ufually more carbonaceous, fubftance than animal matter, and differs from it in the refults of its decompofition principally in not producing volatile alkali ; it forms a great proportion of all peats; it abounds in rich mould, and is found in larger or fmaller quantities in all lands. Saline com- The faline compounds found in foils are very few, and in poinds. quantities fo fmall, that they are rarely to be difcovered. They are principally muriate of foda (common fait), fulphate of magnefia (EpTom fait), and muriate and fulphate of potafti, nitrate of lime, and the mild alkalies. The ANALYSIS OF SOILS. S3 The oxide of iron is the fame with the ruft produced by Oxide of iron, expofing iron to the air and water ; it is found in all foils, but is molt abundant in yellow and red clays, and in yellow and red filiceous fands. A more minute account of thefe different fubftances would be incompatible with the object of this paper. A full de- fcription of their properties and agencies may be found in the elementary books on chemiftry, and particularly in the S) ftem of Chemiftry by Dr. Thomfon (2d Ed.) ; and in Henry's Epitome t)f Chemiftry. III. lnjtruments required for ike Analyfis of Soils. The really important inftruments required for the analyfis instruments for of foils are few, and but little expenfive. They are a balance fnaiyfi*- A ba- uir * • ■ . e ■ i c /• -i ,ance> w 'gh;s» capable ot containing a quarter or a pound of common loir, f,eve> ]amp> and capable of turning when loaded, with a grain ; a feries bottles, cru- of weights from a quarter of a pound Troy to a grain; a wire °^^ mortar* fieve, fufficiently coarfe to admit a pepper corn through its filters, knife, apertures; an Argand lamp and (land; fome glafs bottles'; app* or8aes* Heffian crucibles; porcelain, or queen's ware evaporating bafons; a Wedgewood peftle and mortar; fome filters made of half a fheet of blotting paper, folded fo as to contain a pint of liquid, and greafed at the edges ; a bone knife, and an apparatus for collecting and meafuring aeriform fluids. The chemical fubftances or reagents required for leparating Re-agents, the constituent parts of the foil, are muriatic acid (fpirit of Mur- and futp. fait), fulphuric acid, pure volatile alkali diflblved in water, pf^JJ^ ^ folution of pruffiate of potato, foap lye, folution of carbonate lye, caib. amm. of ammoniac, of muriate of ammonia, folution of neutral car- mu.r af"m* ' carb. pot; Donate of potam, and nitrate of ammoniac. An account of nitr. amm. the nature of thefe bodies, and their effects, may be found in the chemical works already noticed ; and the reagents are fold together with the inftruments mentioned above, by Mr. Knight, Fofter Lane, Cheapfide, arranged in an appropriate cheft. IV. Mode of collecting Soils for Analyfis. In cafes when the general nature of the foil of a field is to How famples of be afcertained, fpecimens of it ftiould be taken from different foils ^re to *• places, two or three inches below the furface, and examined as to the fimilarity of their properties. It fometimes happens, that upon plains the whole of the upper jftiatura of the land is G2 «£ g£ ANALYSIS OF SOILS. of the fame kind, and in this cafe, one analyfis will be fuffi- cient ; but in vallies, and near the beds of rivers, there are very great differences, and it now and then occurs that one part of a field is calcareous, and another part filiceous; and in this cafe, and in analogous cafes, the portions different from each other fhould be feparately fubmitted to experiment, and preferved if Soils when collected, if they cannot be immediately ex* needful. amined, mould be preferved in phials quite filled with them, and clofed with ground glafs ftoppers. The quantity of foil molt convenient for a perfect analyfis, is from two or four hundred grains. It fhould be collected in dry weather, and expofed to the atmofphere till it becomes dry to the touch. The fpecific The fpecific gravity of a foil, or the relation of its weight gravity t0 that of water, may be afcertained by introducing into a phial, which will contain a known quantity of water, equal volumes of water and of foil, and this may be eafily done by pouring in water till it is half full, and then adding the foil till the fluid rifes to the mouth ; the difference between the weight of the foil and that of the water, will give the refult. Thus if the bottle contains four hundred grains of water, and gains two hundred grains when half filled with water and half with foil, the fpecific gravity of the foil will be 2, that is, it will be twice as heavy as water, and if it gained one hundred and fixty-five grains, its fpecific gravity would be 1825, water being 1000. Is ofimportancc It is of importance, that the fpecific gravity of a foil fhould to be known. ^ jtnown> as lt affords an indication of the quantity of animal and vegetable matter it contains; thefe fubftances being always moft abundant in the lighter foils. Other phyfical The other phyfical properties of foils fliould likewife be ex- properties. amined before the analyfis is made, as they denote, to a cer- tain extent, their compofition, and ferve as guides in directing the experiments. Thus filiceous foils are generally rough to the touch, and fcratch glafs when rubbed upon it ; aluminous foils adhere ftrongly to the tongue, and emit a ftrong earthy fmell when breathed on ; and calcareous foils are foft, and much Ids adhefive than aluminous foils. V.Modt ANALYSIS OF SOILS. 8.5 V. Mode of ascertaining the Quantity of Water of Ahforption in Soils. Soils, though as dry as they can be made by continued ex- Evaporation of pofure to air, in all cafes ilill contain a confiderable quantity the airbed of water, which adheres with great obflinacy to the earths and jts quantity in* animal and vegetable matter, and can only be driven ofFfrom foils, them by a confiderable degree of heat. The firft procefs of analyfis is, to free the given weight of foil from as much of this water as poffible, without in other refpecls, affecting its compofition; and this maybe done by heating it for ten or twelve minutes over an Argand's lamp, in a bafon of porce- lain, to a temperature equal to 300 * Fahrenheit ; and in cafe a thermometer is not ufed, the proper degree may be eafily afcertained, by keeping a piece of wood in contact with the bottom of the dim ; as long as the colour of the wood remains unallered, the heat is not too high; but when the wood begins to be charred, the procefs mutt be (topped, A fmal] quantity of water will perhaps remajn in the foil even after this opera- tion, but it always affords ufeful comparative refulls j and if a higher temperature were employed, the vegetable or animal matter would undergo decompofition, and in confequence the experiment be wholly unfatisfactory. The lofs of weight in the procefs lliould be carefully noted, One- eighth is and when in four hundred grains of foil it reaches as high as an extreme pro- 50, the foil may be confidered as in the greateft degree abfor- P°r 10n* bent, and retentive of water, and will generally be found to contain a large proportion of aluminous earth. When the lofs is only from 20 to 10, the land may be confidered as only ilightly abforbent and retentive, and the filicious earth as moll abundant. VI. Of the Separation of Stones, Gravel, and vegetable Fibres from Soils. None of the Ioofe ftones, gravel, or large vegetable fibres Stones, &c. to fliould be divided from the pure foil till after the water is drawn be feParatt? a&- off; for thefe bodies are themfelves often highly abforbent and &c. retentive, and in confequence influence the fertility of the land. * In feveral experiments, in which this procefs has been carried on by diftillation, I have found the water that came over pure, and no feniible quantity of other volatile matter was produced. The \ 35 ANALYSfS OF SOILS. The next procefs, however, after that of heating, ftiould be their reparation, which may be eafily accompli (lied by the fieve, alter the foil has been gently bruifed in a mortar. The weights of the vegetable fibres or wood, and of the gravel and (tones (hould be feparately noted down, and the nature of the laft afcertained; if calcareous, they will eflfervefce with acids ; if filiceous, they will be fufficiently hard to fcratcfy glafs ; and if of the common aluminous clafs of ftones, they will be foft, eafily fcratched with a knife, and incapable pf effervefcing wiih acids. VII. Separation of the Sand and Clay, or Loamk from each other. Sand, day, and The greater number of foils, befides gravel and ftones, con- fr-m eTh^other ta'n 'arger or fmal'er proportions of fand of different degrees by eluiriation. of finenefs ; and it is a neceffary operation, the next in the procefs of analyfis, to detach them from the parts in a ftate of more minute divifjon, fuch as clay, loam, marie, and ve- getable and animal matter. This may be effected in a way fufficiently accurate, by agitation of the foil in water. In this cafe, the coarfe (and will generally feparate in a minute, and the finer in two or three minutes, whilft ihe minutely divided earthy, animal, or vegetable matter will remain in a ftate of mechanical fufpenfion for a much longer time; fo that by pouring the water from the bottom of the veffel, after one, two, or three minutes, the fand will be principally feparated from the other fubftances, which, with the water containing them, mud be poured into a filter, and after the water has pafled through, collected, dried and weighed. The fand muft Jikewife be weighed, and their refpeclive quantities noted down. The water of lixiviation muft be prelerved, as it will be found to contain the faline matter, and the foluble animal or vegetable matters, if any exift in the foil. VIII. Examination of the Sand, The fand fc?a- By the procefs of warning and filtration, the foil is feparated cLVLd ca-ci- 'nto two Portions» the moft important of which is generally the reous. finely divided matter. A minute analyfis of the fand is feldom or never neceffary, and its nature may be deteded in the fame manner as that of the ftones or gravel. It is always either (iiicious fand, or calcareous land, or a mixture of both. U it confifts ANALYSIS OF SOILS. gj confifts wholly of carbonate of lime, it will be rapidly foluble in muriatic acid, with effervefcence ; but if it confift partly of this fubftance, and partly of filiceous matter, the refpective quantities may be afcertained by weighing the refiduum after the action of the acid, which mud be applied till the mixture has acquired a four tafte, and has ceafed to effervefce. This refiduum is the filicious part : it muft be wathed, dried, and heated ftrongly in a crucible; the difference between the weight of it and the weight of the whole, indicates the proportion of calcareous fand. IX. Examination of the finely divided Matter of Soils, and Mode of detecting mild Lime and Magnefea. The finely divided matter of the foil is ufually very compound The findy di- in its nature; itfometimes contains all the four primitive earths treate(j. of foils, as well as animal and vegetable matter; and to afcer- . tain the proportions of thefe with tolerable accuracy, is the raoft difficult part of the fubject. The firfl procefs to be performed, in this part of the analytic Muriatic acid is the expofure of the fine matter of the foil to the action of the ™g" JJfJ' ™' muriatic acid. This fubftance fhould be poured upon the earthy iron, matter in an evaporating bafon, in a quantity equal to twice the weight of the earthy matter; but diluted with double its volume of water. The mixture mould be often ftirred, and fuffered to remain for an hour or an hour and a half before it is examined. If any carbonate of lime or of magnefia exift in the foil, they will have been diffolved in this time by the acid, which- fometimes takes up likewife a little oxide of iron ; but very feldom any alumine. jPl The fluid mould be patted through a filter; the folid matter Preclp. of iron collected, wathed with rain water, dried at a moderate heat, (lf £rdf,nt?. Ly ... pruff. alkah j and weighed. Its lofs will denote the quantity of folid matter taken up. The warnings muft be added to the folution, which if not four to the tafte, muft be made fo by the addition of frefh acid, when a little folution of common prufliate of potam muft: be mixed with the whole. If a blue precipitate occurs, it de- notes the prefence of oxide of iron, and the folution of the prufliate muft be dropped in till no farther effect is produced. To afcertain its quantity, it muft be collected in the fame manner as other folid precipitates, and heated red; the refult is oxide of iron. Into ss and earth, by carbonate of potajh. .A'uTijne if taken up. Carbonate of lime if in p'entv, jnay betftimated by ihe quantity ef carbonic acid. ANALYSIS OF SOIL?. Into the fluid freed from oxide of iron, a folution of neuT tralized carbonate of potato mufi be poured till all effervescence ceates in it, and till its tafte and fmell indicate a confiderable excefs of alkaline fait. The precipitate that falls down is carbonate of lime; it mutt be collected on the filter, and dried at a heat below that of rednefs. The remaining fluid mud be boiled for a quarter of an hour, when the magnefia, if any exifi, will be precipitated from it, combined with carbonic acid, and its quantity is to be afcertained in the fame manner as that of the carbonate of lime. If any minute proportion of alnmine fhould, from peculiar circumftances, be diflblved by the acid, it will be found in the precipitate with the carbonate of lime, and it may be feparated from it by boiling for a few minutes with foap lye, (ufficient to cover the Mid matter. This fubftance diflblves alumine, without acling upon carbonate of lime. Should the finely divided foil be fuffidently calcareous to effervefce very firongiy with acids, a very fimple method may be adopted for afcertaining the quantity of carbonate of lime, and one fuffkjently accurate in all common cafes. Carbonate of lime, in all its dales, contains a determinate* proportion of carbonic acid, i. e. about 45 per cent, fo that when the quantity of this eiaftic fluid, given out by any foil during the folution of its calcareous matter in an acid is known, either in weight or meafure, the quantity of carbonate of lime may be eafjly difcovered. When the procefs b) diminution of weight is employed, two parts of the acid and one part of the matter of the foil mufi: be weighed in two feparate bottles, and very flowlv mixed together till the effervelcence ceafes ; the difference between their weight before and after the experiment, denotes the quantity of carbonic acid loll ; for every four grains and a half of which, ten grains of carbonate of lime mult be eftimated. The beft method of collecting the carbonic acid, (o as to difcover its volume, is by the pneumatic apparatus, the con- flruclion and application of which is deicribed at the end of this paper. The eftimation is, for every ounce meafure o£ carbonic acid, two grains of carbonate of lime. X. Mode ANALYSIS OF SOILS. $£ JC. Mqdeof afcertaining the Quantity of infoluhle finely divided Animal and Vegetable Matter, After the fine matter of the foil has been a&ed upon by Ignition in ati muriatic acid, the next procefs is to afcertain the quantity of deftroys vege- iinely divided infoluble animal and vegetable matter that it table and animal contains. *uttcrs- This may be done with fufficient precifion, by heating it to flrong ignition in a crucible over a common fire til! no black- jiefs remains in the mafs. It mould be often ftirred with a metallic wire, fo as to expofe new furfaces continually to the air; the lots of weight that it undergoes denotes the quantity of the fuhfiance that it contains deftructible by fire and air. It is not poffible to afcertain whether this fubftance is wholly animal or vegetable matier, or a mixture of both. When the fmeli emitted during the incineration is fimilar to that of burnt The fmell fhews r , . . ....'. r r , whether it be leathers, it is a certain indication or tome animal matter ; an;mai Qr vegc, and a copious blue flame at the time of ignition, almoft always tabic. denotes a confiderable proportion of vegetable matter. In cafes when the experiment is needed to be very quickly per- formed, the deftruclion of the decompofible fubftances may- be aflifled by the agency of nitrate of ammoniac, which at the time of ignition may be thrown gradually upon the heated mafs in the quantity of twenty grains for every hundred of rehdual foil. It affords the principle neceflary to the combuf* tion of the animal and vegetable matter, which it caufes to be converted into elaftic fluids ; and it is itfelf at the fame time tlecompofed and loft. XI. Mode of feparating aluminous andfilicious Matter and Oxide of Iron. The fubftances remaining after the decompofition of the ^e refidual .iii-i 11 . . , tilex, aluminc vegetable and animal matter, are generally minute particles and oxide of of earthy matter, containing ufually alumine and filex with iron Separated. combined oxide of iron. To feparate thefe from each other, the folid matter mould be boiled for two or three hours with fulphuric acid, diluted with four times its weight of water ; the quantity of the acid mould be regulated by the quantity of folid refiduum D!,ute falphunc to be aaed on, allowing for every hundred grains two drachms two &ft! "P ** m one hundred and twenty grains of acid. The 90 ANALYSIS OF SOILS. The fubftance remaining after the adlion of the acid, may be confidered as filicious; and it muft be feparated and its weight afcertained, after wafhing and drying in the ufual manner. Carbonate of Thealumine and the oxide of iron, if they exift, are both n^cdi!W*diflblved by the fulPhuric acid; the)' mav be Separated by mine, carbonate of ammoniac, added to excefs ; it throws down the alumine, and leaves the oxide of iron in folution, and this fubftance may be feparated from the liquid by boiling. Should any magnefia and lime have efcaped folution in the muriatic acid, they will be found in the fuiphuric acid ; this, however, is fcarcely ever the cafe; but the procefs for detecting them and afcertaining their quantities, is the fame in both inftances. More accurate The method of analyfis by fuiphuric acid, is fufficiently procefs. precife for all ufual experiments; but if very great accuracy be an object, dry carbonate of potafh muft be employed as the agent, and the refiduum of the incineration muft be heated red for half an hour, with four times its weight of this fub- ftance, in a crucible of filver, or of well baked porcelain. The mafs obtained muft be diflblved in muriatic acid, and the folution evaporated till it is nearly folid ; diftilled water muft then be added, by which the oxide of iron and all the earths, except filex, will be diffolved in combination as muriates. The filex, after the ufual procefs of lixiviation, muft be heated red ; the other fubftances may be feparated in the fame manner as from the muriatic and fuiphuric folutions. This procefs is the one ufual ly employed by chemical phi* Jofophers for the analyfis of ftones. XII. Mode of difcovering foluble Animal and Vegetable ■ Matter, and Saline Matter, Matter* foluble If any faline matter, or foluble vegetable or animal matter, in water. »g fufpeftecj jn ,the foil, it will be found in the water of lixivia- tion ufed for feparating the fand. This water muft be evaporated to drynefs in an appropriate difli, at a heat below its boiling point. If the folid matter obtained is of a brown colour and inflam- mable, it may be confidered as partly vegetable extracl. If its fmell, when expefed to heat, be ftrong and fetid, it contains animal mucilaginous or gelatinous fubftance; if it be' white ANAtTTSIS OF SOILS, £j while and tranfparent, it may be confidered as principally faline matter. Nitrate of potafti (nitre) or nitrate of lime, is indicated in this faline matter, by its fcintillating with a burning coal. Sulphate of magnelia may be delected by its bitter tafte; and fulphate of potalh produces no alteration in folution of carbonate of ammoniac, but precipitates folution of muriate of barytes, XIII. Mode of detecting Sulphate of Lime (Gypfam) and Phofphate of Lime in Soils. Should fulphate of phofphate of lime be fufpecled in the Sulphate of entire foil, the detection of them requires a particular procefs iaie* upon it. /± given weight of it, for in fiance four hundred grains, muft be heated red for half an houi in a crucible, mixed with one-third of powdered charcoal. The mixture muft be boiled for a quarter of an hour, in a half pint of water, and the fluid collected through the filter, and expofed for fome days to the atmofphere in an open veflel. If any foluble quantity of fulphate of lime (gypfum) exifted in the foil, a white precipitate will gradually form in the fluid, and the weight of it will indicate the proportion. Phofphate of lime, if any exift, may be feparated from the Phofphate of foil after the procefs for gypfum. Muriatic acid muft beiim*4 digefted upon the foil, in quantity more than fufhcient to faturate the foluble earths ; the folution muft be evaporated, and water poured upon the folid matter. This fluid will dif- folve the compounds of earths with the muriatic acid, and leave the phofphate of lime untouched. It would not fall within the limits afligned to this paper, to detail any procefles for the detection of fubftances which may be accidentally mixed with the matters of foils. Manganefe \ is now and then found in them, and compounds of the barytic earth ; but thefe bodies appear to bear little relation to fertility or barrennefs, and thefearchfor them would make the analyfis much more complicated without rendering it more ufeful. XIV. Statement of Refults and Products, When the examination of a foil is compleated, the products Products iia$e!» mould be clafled, and their quantities added together, and if they nearly equal the original quantity of foil, the analyfis may be confidered as accurate. It muft, however, be noticed, 3 that 92 ANALYSIS OF SOILS. that when phofphate or fulphate of lime are difcovered by tho independent procefs XIII. a correction muft be made for the general procefs, by fubtracting a fum equal to their weight from the quantity of carbonate of lime, obtained by precipi- tation from the muriatic acid. In arranging the produd:?, the form mould be in the order of the experiments by which they were obtained. Thus 400 grains of a good filicious fandy foil may be fup- pofed to contain Grains. Of water of abforption - . 18 Ofloofe ftonesand gravel principally filicious 42 Of undecompounded vegetable fibres . 10 Of fine filicious fand .. 200 Of minutely divided matter feparated by fillral :ion and confifting of Carbonate of lime - 25 Carbonate of magnefia - - - 4 Matter deftru&ible by heat, principally ve- getable .... 10 Silex ..... 40 Alumine - 32 Oxide of iron - * Soluble matter, principally fulphate of pot- ato, and vegetable extract 5 pypfura - 3 fhofphate of lime - - « 2 125 Amount of all the produces 395 Lofs m - - 5, In this inftance the lofs is fuppofed fmall ; but in general, in actual experiments, it will be found much greater, in con- fequence of the difficulty of collecting the whole quantities of the different precipitates; and when it is within thirty for four hundred grains, there is no reafon to fufpect any want of due precifion in the procefles. XV. This general Method of Analyfis may in many Cafes be much jlmptifted. Simplification, When the experimenter is become acquainted with the ufe &c. of the 0f ijie different inftruments, the properties of the reagents, and ANALYSIS OF SOILS, 33 and the relations between the external and chemical qualities of foils, he will feldom find it neceflary to perform, in any one cafe, all the procelfes that have been defcribed. When his foil, for inftance, contains no notable proportion of cal- careous matter, the action of the muriatic acid IX. may be omitted. In examining peat foils, he will principally have to attend to the operation by fire and air X. ; and in the analyfis of chalks and loams, he will often be able to omit the ex- periment by fulphuric acid XI. In the firft trials that are made by perfons unacquainted with chemiftry, they muft not expect much precifion of refult. Many difficulties will be met with ; but in overcoming them, the mod ufeful kind of practical knowledge will be obtained ; and nothing is fo instructive in experimental fcience, as the * detection of raiftakes. The correct analyft ought to be well grounded in chemical information ; but perhaps there is no better mode of gaining it, than that of attempting original inveiligations. In purfuing his experiments, he will be con- tinually obliged to learn from books, the hiftory of the fub- ftances he is employing or acting upon ; and his theoretical ideas will be more valuable in being connected with practical operation, and acquired for the purpofe of difcovery. XVI. On the Improvement of Soils, as connected with the Principle of their Composition. . In cafes when a barren foil is examined with a view to its Improvement of improvement, it ought in all cafes, if poffible, to be compared known com- with an extremely fertile foil in the fame neighbourhood, and portion of fer- in a fimilar fituation: the difference given by their analyfes ^£ would indicate the methods of cultivation j and thus the plan of improvement would be founded upon accurate fcientific*. principles. If the fertile foil contained a large quantity of fand, in pro- portion to the barren foil, the procefs of amelioration would depend limply upon a fupply of this fubftance ; and the method would be equally fimple with regard to foils deficient in clay or ealcareous matter. In the application of clay, fand, loam, marie, or chalk to lands, there are no particular chemical principles to be ol- f a principle effential to their produdive- nefs, ought to be much greater in warm and dry countries, than in cold and moift ones; and the quantity of fine aluminous earth they contain larger. Soils likewiie that are fituated on declivities, ought to be more abforbent than thofe in the fame climate on plains or in valleys f . The produdtivenefs of foils muft likewife be influenced "by the nature of the fubfoil, or the earthy or ftony ftrata on which they reft ; and this cir* cumftance ought to be particularly attended to, in confidering their chemical nature, and the fyitem of improvement. Thus a fandy foil may fometimes owe its fertility to the power of the fubfoil to retain water; and an abforbent clayey foil may occafionally be prevented from being barren, in a moift climate^ by the influence of a fubftratum of fand or gravel. ^ XVIII. Of the chemical Compofition of fertile Corn Soils in the Climate. Aftua] compofi- Thofe foils that are moft productive of corn, contain always tion ot fame certain proportions of aluminous and calcareous earth in a fertile foils. ...... „ . . r Li finely divided ftate, and a certain quantity of vegetable or animal matter. • Phil. Tranfaftions for 1759, p. 305. This limeftone is found • abundantly in Yorkfliire, D-Jibyihire, and Som rfetthire, -| Kii wan. Tranf, Irim Academy, Vol. V. p. 175. \ The ANALYSIS OF SOILS. Q$ The quantity of calcareous earth is however very various, and in fome cafes exceedingly fmall. A very fertile corn foil from Ormiflon in Eaft Lothian afforded me in an hundred parts, only eleven parts of mild calcareous earth ; it con- tained twenty-five parts of filicious fand ; the finely divided clay amounted to forty-five parts. It loft nine in decompofed animal and vegetable matter, and four in water, and afforded indications of a fmall quantity of phofphate of lime. This foil was of a very fine texture/ and contained very few Hones or vegetable fibres. It is not unlikely that its fertility was in ibrtre meafure connecled'with the phofphate; for this fubftance is found in wheat, oats, and barley, and may be a part of their food. A foil from the low lands of Somerfetfhire, celebrated for producing excellent crops of wheat and beans without manure, I found to confift of one-nintli of fand, chiefly filicious, and eight-ninths of calcareous marie tinged with iron, and contain- ing about five parts in the hundred of vegetable matter. I could not dete6t in it any phofphate or fulphate of lime, fo that its fertility muft have depended principally upon its power of attracting principles of vegetable nourifhment from water and theatmofphere *. Mr, Tillet, in fome experiments made on the compofition of foils at Paris, found that a foil compofed of three-eighths of clay, two-eighths of river fand, and three*eighths of the" parings of Jimeftone, was very proper for wheat. XIX. Of the Compofition of Soils proper for bulbous Roott and for Trees. In general, bulbous roots require a foil much more fandy, Soils proper for- and lefs abforbent than the grafTes. A' very good potatoe foiI,'bulbous roots from Varfel in Cornwall, afforded me feven-eighths of filicious fand ; and its abforbent power was lo fmall, that one hundred parts loft only two by drying at 400 Fahrenheit. Plants and frees, the roots of which are fibrous and hard, and capable of penetrating deep into the earth, will vegetate to advantage in almoft all common foils, which are moderately dry, and which do not contain a very great excels of vege* table matter. * This foil was fentvto me by T. Poole, Efq. of Nether Stowey, It is near the opening of the river Parret into the Eritifh Channel j but, I am told, is never overflowed, I found 90 ANALYSIS OP SOILS, I found the foil taken from a field at Sheffield-place in Suffex, remarkable for producing flourifhing oaks, to confift of fix parts of land, and one part of clay and finely divided matter* And one hundred parts of the entire foil fubmitted to analyfis, produced Parts. Water ..... 3 Silex .*--.- 54* Alumine - 28 Carbonate of lime ... 3 Oxide of iron .... 5 Decompofing vegetable matter - * Lofs 3 XX. Advantages of Improvements made by changing the Com* pofition of the earthy Parts of Soils, Soils rendered From the great difference of the caufes that influence the fertile by chang- produaivenefs of lands, it is obvious that in the prefent ftate mg the compofi- r , , ' * . . of Icience, no certain fyftem can be devifed from their im- provement, independent of experiment ; but there are few cafes in which the labour of analytical trials will not be amply repaid by the certainty with which they denote the bed methods of amelioration ; and this will particularly happen, when the defect of compofition is found in the proportions of the primitive earths. In fupplying animal or vegetable manure, a temporary food only is provided for plants, which is in all cafes exhaufted by means of a certain number of crops ; but when a foil is render- ed of the belt pofiible conftitution and texture, with regard to its earthy parts, its fertility may be considered as per- manently eftabliihed. It becomes capable of attracting a very large portion of vegetable nourifliment from the atmofphere, and of producing its crops with comparatively little labour and expence. rion of the carrhy parts, are more per- manent than manured foils. Apparatus for c*£eriments» Dcfcription of the Apparatus for the Analyfs of Soils, A. Retort. B. B. Funnels for the purpofe of filtrating. D. Balance. E. Argaim's lamp. F. G, H, K. The different par's of the apparatus required for meaning the iiuantity of elaftic fluid given out during tho :new vegetable substance. Q"J the a&ion of an acid on calcareous foils. F. Reprefenls the bottle for containing the foil. K. The bottle containing the acid furnifhed with a ftopcock. G. The tube connected with a flaccid bladder. I. The graduated meafure. H. The bottle for containing the bladder. When this inftrument is ufed, a given quantity of foil is introduced into F; K is filled with muriatic acid diluted with an equal quantity of water; and the (lop-cock being clofed is connected with the upper orifice of F, whieh is ground to receive it. The tube G is introduc- ed into the lower orifice of F, and the bladder connected with it placed in its flaccid ftate into H, which is filled with water. The graduated meafure is placed under the tube of H. When the flop-cock of K is turned, the acid flows into F, and ads upon the foil; the elaftic fluid generated partes through G into the bladder, and difplaces a quantity of water in H equal to it in bulk, and this water flows through the tube into the graduated meafure ; the water in which gives by its volume ihe indication of the proportion of carbonic acid difengaged from the foil ; for every ounce meafure of which two grains of carbonate of lime may be eftimated. ^ L. Reprefents the ftand for the lamp. M, N, O, P, Q, R, S. Reprefent the bottles containing the different reagents. IV. Difcovery of a new Vegetable Subjlance, by Mr. Rose *. A CONCENTRATED decoaion of the root of elecam- Decoflion of pane, inula hcleniwn, after flanding fome hours, depofits a elecampane root i • • r i t> depofits a pow- white powder, appearing at fit It fight much like narch,,* but der refembling differing from it both in its principles and in its manner offlarch* comporting itfelf with other fubftances. 1. This fubflance is generally infoluble in cold water, it is infolubleia Being triturated with it a white milky liquor is formed, which cold water« foon depofits a heavy white powder, and leaves the fuper- natant water clear and limpid. 2. It diflblves very well in boiling water. On heating to Soluble ?n boii- ebullition one part of the white powder, with four parts of ,n§ Writeu * From Gehlen's Journal for 1804, Vol, IILp. 217. Vol. XII. — Octqbeu. \ H water, 9§ KEW VEGETABLE SUBSTANCE. water, a complete folution is obtained, which pafles through filtering paper while hot, but on cooling acquires a mucila- But much fub- ginous confiftence and a dull colour. In the courfe of forae fides on cooling. houf8 this folution depofits the greater part of the fubftance diflblved in the form of a compact white powder. Differs from A folution of one part of gum arable, in four parts of folution of gum- water is much thicker, of a more tenacious confidence, and froths lightly, which the folution of the powder from the elecampane root does not. Alcohol fepa- 3. On mixing the folution of the white powder with an rates it from equal quantity of alcohol, the mixture is at firft clear, but in a little time the powder feparates in the form of a tumid white does not gum- fediment, leaving the fluid above it tranfparent. A folution arabic. Qf gum-arabic on the addition of alcohol becomes immediately milky, and long retains this appearance, no kind of powder (eparating even in feveral days. Melts, emits a 4. When thrown on burning coals, the white powder melta thick fmoke, like fugar and evaporates, difTufin£a white, thick, pungent and leaves little , 6 \" ' Ar . • . r- refiduum.- fmoke, with a lmell of burnt lugar. After this combuftion a Thus differs light refiduum only remains, which runs into the coal. Starch 1 emits a (imilar fmoke, but does not melt, and leaves a coally and from gum. refiduum much greater in quantity. Gum-arabic under the fame circumftances gives out fcarcely any fmoke. On red hot iron Heated in an iron fpoon over charcoal the powder firft bums. melts, and' emits the fmoke above defcribed. As foon as the fpoon becomes red hot, it burns with a vivid light flame, and Starch. leaves a very trifling coally refiduum. Starch under the fame circumfiances does not melt, *is much longer before it burns, Gum. and leaves a conn" derable refiduum of coally matter. Gum- arabic only fparkles, does not take fire, and leaves a great deal of coal, which is readily convertible into grayifli allies. Drydlftillation 5. By dry difiillaticn we obtain from this powder of the produces an acid, e|ecampane root a brown empyreumatic acid, having the fmell of pyroxalic acid, but not an atom of empyreumatic oil. Niirid acid pro- 6. The nitric acid transforms the powder only into malic duces make, acjcj an(j oxajjc acid, and when ufed in great excefs into oxaiic, and in . , , . . ,. . r . . «. excefs acetic, acetic acid : but we do not obtain an atom of. the laccholactic Gum the fac- acid, which gum-arabic treated in the fame manner furnilhes Starch fat. ' ' f° abundantly ; or of the fatty matter which is generated by the aclion of nitric acid on fiarch. 2 From GALVANIC DISCOVERIES. Qg From all thefe phenomena it follows, (hat (his farinaceous Hence of a powder extraded from elecampane root, is neither fiarch nor "^^^ch gum, but a peculiar vegetable fubftance holding a middle and probably rank, between the two. It is probable, that it exifts in many exifts '" othcr other vegetables, and that feveral proda&s hitherto confidered as ftarch are of the fame nature as this farina. V. New Galvanic Difcovcries by Mr. Ritter, extracted from a Letter from Mr, Christ. Bernoulli*. 1 HERE tranfmit yon the information you requefted re- fpefting the late experiments of Mr. Ritter, to which I fub- join fome account of that gentleman. 1. Charging of a Louis d'Or by the Pile, The pile with which Mr. Ritter ufually makes his expert- Mr. Ritter'i ments confifts of a hundred pairs of metallic plates, two inches in diameter. The pieces of zinc have a rim to prevent the Uquid preffed out from flowing away. The apparatus i3 always infulated by feveral plates ofglafs. As Mr. Ritter at prefent refides in a village near Jene, I His grand have not been able to fee his experiments with his grand °atte;y> ir 'at*ge battery, battery of two thoufand pieces, or with his battery of fifty pieces, each thirty-fix inches fquare, the aclion of which con- tinues very perceptible for a fortnight. Neither have I feen his experiments with the new battery of his invention * con- fitting of a fingle metal, and which he calls the charging and charging pile. pite- I have frequently however, feen him galvanife loui# d'or Louis dVr lent him by perfons prefent. To effeft this, he places the Jarged hy. louis between two pieces of pafteboard thoroughly wetted, the galvanic and keeps it fix or eight minutes in the chain of circulation circuit, connected with the pile. Thus the louis becomes charged, without being immediately in contact with the conducting wires. If this louis be applied afterward to the crural nerves excites contrac- of a frog recently prepared, the ufual contractions will be tlons> * Tranflated from the Journal de Chimie and d* Phyfique of Van Mons, No. 17, p. 133, March, 1805. H 2 excited. JQQ GALVANIC DISCOVERIES. and tmythus be excited. I had put a louis thus galvanifed into my pocket, ainon^others, and ^r» Ritter faid to me a few minutes after, that I might find out this louis from among the reft, by trying them in fucceftion upon the frog. Accordingly I made the trial, and in reality diftinguifhed among feveral others a fingle one, in as it docs not vvhich the exciting quality was very evident. This charge is lofe its charge ... . J , f ' . . . °. for fome retained in proportion to the time that the piece has remained minutes. jn tne circuit of the pile. Of three different louis which Mr. Ritter charged in my prefence, neither loft its charge in lefs than five minutes. All thefe experiments fucceeded com- pletely, and nothing feemed fo eafy as to repeat them. This /Vows the This retention of the galvanic charge by a metal in contact nity ° r ,e with the hand, and with other metals, (hews this communica- galvanic with 9 . * the magnetic tion of the galvanic virtue fo have more affinity with mag- flutd, between neljfm t[)an wjth electricity, and afligns to the galvanic fluid which and the , , , , declr-c, it holds an intermediate rank between the other two. a middle place. jn the manner which I have j uft defcribed, Mr. Ritter can Several pieces +•/*«»• may be charged charge at once as many pieces as he withes. It is luthcient at once. if the two extreme pieces of the number communicate with the pile through the intervention of wet pafteboards. It is with metallic difes charged in this manner, and placed upon one another with pieces of wet pafteboard alternately inter- Ritterian pile, pofed, that Mr. Ritter conftru&s his charging pile, which ought in remembrance of its inventor to be called the Ritterian Metals thus pile. The'; conftru&ion of this pile fliows, that each metal charge acquire ga]vanjfeci jn this way acquires polarity, as the needle does when touched with a magnet. Though I have had no op- portunity of feeing this new pile, I have convinced myfelf of the reality of the phenomenon by an experiment of the higheft importance to fcience, and for the invention of which we are equally indebted to the fame ingenious philofopher. 2. Different Excitability of the Parts of Animals. Different exci- During the coupfe of feveral years in which Mr. Ritter has 'arts''©!* Animals ^een emP'°)'ed in galvanic purfuits, and during which he has made many thou fands of experiments on the excitation pro- duced in the frog by the contact of two different metals, for Mr. Ritter has not entirely abandoned the original mode of galvanifing, like moil other experimentalifts, who employ Volta's pile exclufively ; he had perceived not only a very linking difference in the excitability of the different parts of animals, GALVANIC DISCOVERIES. }Q\ animal?, but alio a difference of excitement between the extenfor and flexor mufcles, according as the pofitive or nega- tive pole was applied to them, or as they were acled upon the intrant after the metals were brought into contact or feparated from each other. When the excitability is at its hijrheft point of energy, as in When the exci- c c'J c , A ' tability of che very young frogs the moment after they are prepared, or in an;ma| is adult frogs during the coupling feafon, the flexors alone con- greateft, the tract, and in particular the flexor mufcles of that thigh to bypoficWe gaU which the filver or negative metal is applied, contract at thevanifm; inftant when the metais come into contact, while thofe of the thigh to which the zinc or pofitive metal is applied, contract at the inftant of their feparation,. Theoppoiite effects are obfervable in frogs, the excitability when it is lowed of which is on the point of being, extinguished, (Ritter's fifth *'£^f°r8 degree.) In this cafe the extenfors only contract, and the negative, flexors remain abfolutely motionlefs. At the moment of Contact of the metals the mufcles on the zinc fide alone are thrown into action, and at the moment of feparation thofe on the filver fide. Mr. Ritter diftinguiflies three degrees of mean excitability. When the ecci- At the fecond degree (the firft of the three mean degrees,) ^eVn^he me- when the metals are brought into contact, a ftrong excitement dium and either of the flexors is difplayed on the filver fide, ^nd a weak ^dtln ^ excitement of the extenfors on the zinc fide ; ana when the fl-xors and ex- melals are feparated a ftrong; excitement of the flexors is feen tcnfors fimulta- ; . L. " , . r i r neous but un" on the zinc tide, and a weak excitement or the extenlors on equal, the filver fide. At the fourth degree of excitability the contrary takes At the medium, place. At the third or middle degree the excitability appears ^^^^J5 to be equally diftribuled, the contractions on each fide appear equal, and at the moment of contact the flexors contract on the filver fide, the extenfors on the zinc fide ; while at the moment of feparation the extenfors contract on the filver tide, and the flexors on the zinc fide. Mr. Ritter fhowed me all thefe phenomena, and it was very eafy to diftinguifh the different contractions. I have not yet had time to repeat thefe experiments, but I am afraid, eafy as they appeared to be, they will require an experienced hand, to produce fuch diftinct effects as I faw. None of the experi- The experi- ments which Mr. Ritter performed before me fucceeded with m™yss f° "c°ee)J him on the firft trial. Mr. Ritter. 102 GALVANIC DISCOVERIES, Mr. Ritter's him (he firft time. Moft of thefe experiments have never yet ficTent"y°ap"f" been made Pub]ic> and fevv philofophers have juftly appre- preciated, ciated the value of thofe which have been given to the world. There are fome people, who, habituated folely to the linking effects of grofler phyfics, fuppofe it impoffible for a young philofopher to fee any thing more than themfelves in the delicate phenomena of a more refined order of phyfical ex- periments. What has greatly contributed to prevent Mr. partly owing to Ritter from attaining the high reputation he deferves is his his ftyle. ftyle, which, by endeavouring to give it preeifion, he has rendered obfcure ; but in converfation it is quite otherwife, as here he combines the ftricleft logic with the greateft fimplicity of expreffion. Account of Mr. Ritter is one of thofe men, who owe every thing to the infpiration of genius, nothing to education. He was intend- ed for a mechanical occupation, when the difcoveries of gaU vani excited in him that innate tafte for the phyfical fciences, which has carried him over every obftacle, and raifed him to rank among the firft natural philofophers. Deftitute of every fource for procuring himfelf the apparatus indifpenfable to ordinary phyfics, but fwayed by the enthufiafm of inquiry, he greedily feized the opportunity of obeying this impulfe by purfuing a feries of experiments, that require only a fimple and not a very expenfive apparatus. Europe has rung with the fuccefs he has obtained within the feven years he has given to his refearches. He muft have written much to procure himfelf a large pile, and the moft neceflary books of natural philofophy. Not lefs indefatigable as an experimenter than ingenious as a theorift, he has committed to writing thoufands of experi- ments, which his time divided between galvanic experiments, application to other branches of phyfics, and the ftudy of languages, has not yet allowed him to put in order for publi- cation. But this (late of confiraint is about to be at an end. The elector Bavaria, that enlightened prince, whofe philo- fophical beneficence attracts to his dominions the moft dif- tinguilhed men of fcience and learning throughout Europe, has juft appointed Mr. Ritter a Member of the Academy of Munich, with a falary of about 200l. a year. He is compo- Mr. Ritter has been employed thefe fix months in COW* fing a fyftermuc p0fJn^ a fyftematic work on galvanifra, but he does not think work, on gal- ' ° J ° . vanilin. • GALVANIC DISCOVERIES. 103 he (hall be able to finiih it in lefs than two or three years. When I left him he was going to publilh Tables of Galvanic Publishing Affinity, including all the fubftances on which he has made ^n" ^Jity. experiments. Thefe tables will be of as much importance to galvanifm as thofe of Bergman were to chemiftry : they will fhow, though not yet in a complete manner, the order in which fubftances follow each other with refpecl to exciting or re- ceiving the galvanic aclidn. But to return to the experiments refpecling the charging of The galvanifed , , ' ■ ' . . x n l • ■ "ft piece of metal metals. Mr. Ritter, alter having mown me his experiments has two poles. on the different contraclibility of various mufcles, made me obferve, that the piece of gold galvanifed by communication exerts at once the adion of two metals, or of one constituent part of the pile; and that the half which was next the nega. tive pole while in the circle became pofitive, and the half toward the pofitive pole became negative. I was completely convinced of the reality of thefe different phenomena, fo important to phytic in general, and to phyfiology in par* ticular. Mr. Ritter having difcovered the method of galvanifing Golden needles metals, as iron is rendered magnetic, and having obferved that fVanjCd an galvanifed metals always exhibit two poles, as the magnetic needle does, had the curiofity to obferve the effect of golden needles charged with galvanifm and balanced on a pivot. To his furprife he perceived, that thefe needles had a certain have totftdlP .. ... . . . , r . . j . and variation, dip and variation, and that the angle ot variation, the quantity but different of which I am forry I cannot recollect, was uniformly the *ro™ the ma£* fame in all his experiments. It differs however from that of "e ' * the magnetic needlej and the pofitive pole always dips. VI. Improvement in applying the Points in Electrical Machines. By Mr. G. J. Singer. To Mr. NICHOLSON. SIR, Princes Street, Sep. 19///, 1805, IN the ordinary conflruction of electrical machines, the col- lecting points are fixed, and by the leaft. accidental motion are liable to fcratch the glafs, to obviate this inconvenience, I place \Q4< ON LIGHT. place my points in a cylindrical wire, terminated by fmooth wooden balls, whofe femidiameler is lefs than the length of the points: This wire is moveable on its axis, by means of a fpring focket annexed to the Item which enters the conductor: The points may of courfe be placed at any required elevation, and the greateft intensity any variation in their fituation pro- duces, be obtained. When the points are elevated a little above the horizontal line, the danger of fcratching the glafs is effectually prevented, by the balls coming in contact while the points are kept at a fmall diftance. The fecurity this application produces, and the additional intenfity it affords, have induced me to trouble you with this communication. I am, Dear Sir, Your's, &c. G. J. SINGER. VII. Quefiion whether Light as a Body may not have its Temperature, raifed or lowered, and produce the Effects afcribed to refiecled Heat. By J. P. To Mr. NICHOLSON. SIR, Queftion re- Jt OSSESSING no differential thermometer, nor any time to> fpeding light. emp]0y j^ J cannot prove whether my opinion is well founded or not, refpecling the ingenious experiments of Mr. Leilie or of M. Pi&et, by which the reflection of invifible (not radiant) heat, and even of cold, appears to have been proved. Initead of there being an actual reflection of heat as a fub- ftance, or of cold as a fubftance, is it not in all thefe cafes a reflection of heated or of cooled light ? In the experiments with the heated cannifter, the light of the room is, I doubt not, heated by the cannifter; and if collected in a focus, muff, produce an effect on the thermometer, anfwerable to the in,- creafed quantity of heat with which it is impregnated. Thus alfo in Monf. Pictet's experiment, the light intercepted by the mirror and thence reflected, has been deprived of a portion of its caloric, or in other words cooled, by the ice ; at the focal EXPERIMENTS ON CERITE. J 05 focal point therefore will be a collection of cooled rays of light, which muft necelfarily occafion an effect on the thermometer, the reverfe of that of the former experiment. That light is a body capable of being united with caloric, and that heated or cooled light mould thus be reflected and occafion all the phe- nomena of Mr. Leflie's and of M. Picket's experiments, apT pears to be much more probable, than that this calorific and frigoriiic fluid {hould be the ambient air, or that cold, as a body, (hould be reflected from mirrors in fuch a manner as light is perhaps only capable of being reflected. Were the experiments Co made that no light ftiould be in the room, and pnly a fmall confined portion of light ufed to examine the thermometer^ thefe conjectures would be put to the trial, and I truft the myftery would be removed. Sir, your's, J. P* VIII. Experiments on a Mineral formerly called falfe Tungfiein, now Cerite, in which a new Metal has been found.* R. Klaproth, about eight months ago, fays Mr. Vauquelin, Klaproth fup- fent me word, that he had difcovered in the tungftein of Baftnas P?fed he had lt ,. , . , r i -i difcovered a new a new earth, to which he gave (he name ot ochroit, on account earth in the of the red colour it acquired by calcination. MetTrs. Hifinger fa,fe tungfteinj and Berzelius, hearing this, wrote to Mr. V. claiming the Hifinger and priority of difcovery, but affirming at the fame time, that what ^^lhxxsanmv they had found was a new metal. Thefe gentlemen afterward fent Mr. V. fpecimens of the mineral, which he analyfed in company wilh two experienced practical chemifts, Me/Trs. Taifaert and Bergman. The following were the refults of their analytis : The pure cerite f is femitranfparent, wilh a flight rofy tinge, Characters of pure cerite. * Abridged from a paper by Vauquelin in the Annalesde Chimie, Vol. LIV. p. 28, and another by Mcffrs. Hifinger and Berzelius in van Mons's Journal de Chimie, VoL VI. p. 142. — C. •\ Meffrs. H. and B. have given to the metal the name of cerion or cerium, from the new planet Ceres, and to the mineral in which they difcovered it that of cerite, or 10Q Treated with nitro-muriatic acid. The folution precipitated by prufliate of potafli and am- monia. Examined by different re- agents. EXPERIMENTS ON CERITE. or of a light or deep flem-colour *. It is fufficiently hard to (cratch glafsf, flrikes lire with difficulty, and its fpecific gravity is 4*530. It has no determinate cryfialline figure. Its fraclure is compact %, and a little {hining. Its powder is of a greyilh colour; it becomes yellow by calcination, and lofes twelve per cent §. Exp. I. Two hundred parts of this mineral treated with ni- tro-muriatic acid three times fucceftively, gave abundance of nitrous acid and oxigenated muriatic acid gas. The firft and fecond folutions being diluted with water were of a gold colour; the third was colourlefs. The former two being mixed depo- rted fpontaneoufly in time a fmall quantity of white fediment. The reiiduum left by the nitro-muriatic acid was of a gray co- lour with a flight rofeate tinge, and weighed 62, fo that 13S parts were diflblved. Exp. 2. The folutions being evaporated to the confidence of fyrup to volatilife, the fuperfiuous acid remained clear to the end of the operation. Their reiiduum, diluted with water, afforded a milky liquor, with a flight rofy tint, and a very afiringent tafle. Prufliate of potafh produced in it a greenifh blue precipitate : the colour of which was changed to a brown by a fmall quantity of ammonia. AW the liquor into which a fmall quantity of ammonia had been put to precipitate the iron alone was poured into a filter, but would not pafs through. It was heated therefore, and filtered, when it appeared of a gold colour, and had a very faccharine tafie. Prufliate of potafh and oxalate of ammonia threw down from it perfectly white precipitates. The matter left on the filter continued for a long time to impart a yellow tinge to the water with which it was waftied. It was of a red colour, and appeared like oxide of iron at a maximum of oxidation. The folution thus deprived of the red matter by ammonia, was examined by various reagents. Prufliate of potafli gave with it a white, ilocculent, gelatinous precipitate. Infufion • Opake, and fometimes but very rarely, yellowifti. Meffirs, H. and B. t Does not fcratch glafs. H. and B, X Unequal and angular. H. and B. § Six or feven. H. and B. ■of EXPERIMENTS ON CER1TE. \QJ of galls, a brown, floeculent fediment, unaffecled by muriatic acid. Carbonate of potafli, a very copious while gelatinous, precipitate. Cauftic potafli, the fame : and an excefs of this reagent produced no change. Oxalate of ammonia, a very copious, white, floeculent precipitate, infoluble in an excels of oxalic acid. Sulphuric acid, a yellow cryftalline precipitate foluble in water. Muriate of tin whitened the folution without forming any precipitate. Exp. 3. After this the folution was evaporated, when it Attempts to free inftantly became turbid, and formed an abundant flelh-coloured l rom iron* depofit. This was treated with acidulous oxalate of potafn to diflblve the iron without fuccefs : the addition of nitric acid was as unfuccefsful : but muriatic acid added to the preceding diflblved the precipitate with effervefcence and the emiffion of oxigenated muriatic acid gas. A white cryftalline fubftance however, remained, confiding of oxide of cerium with oxalic acid. The greater part of the excefs of acid in the folution being falurated with ammonia, oxalate of ammonia was added till no more precipitate was formed. This precipitate had all the properties of oxalate of cerium. Ammonia threw down from the filtered liquor oxide of iron. Exp. 4. The matter precipitated from the folution of cerium Muriate pred- by ammonia in Exp. 2, diflblved with effervefcence in muriatic faJ^f ammonia." acid. Oxalate of ammonia threw down from this folution oxide of cerium, and the filtered liquor contained oxide of iron tolerably pure. . Exp. 5, The liquor freed from the greater part of the iron Nitrate precipi- by ammonia and heat, which had notwithstanding a flight pp* ^j^J^T feate tinge, was precipitated by oxalate of ammonia. The precipitate at the moment of its formation had the appearance of muriate of filver, but Won became granulous and fubfided * in this form. The liquor patted through the filter colourlefs, and the rofy tinge remained in the oxalate.. Exp. 6. As the liquor from which the oxalate of cerium was Oxalate of lime precipitated contained an excefs of acid, it might be prefumed feparate ' to hold in folution mod of the oxalate of lime formed at the fame time, if the cerite contained any. Accordingly it was mixed with the water that had wafhed the precipitate and con- centrated by evaporation, when on the addition of ammonia a imal! quantity of oxalate of lime was thrown down. Exp. 7. As notwithftanding fome oxalate of lime might have Reft of the lime, been precipitated with the oxalate of cerium, a portion of the '^P313^'1, red ]08 EXPERIMENTS ON CERITE. red oxide- of cerium arifing from the decompofition of the ox- alate by calcination was diffolved in muriatic acid. A brifk effervefcence inftantly took place, with the evolution of oxi- genated muriatic gas, which continued till the whole was dif- folved, and differed in no refpect. from that prepared with oxide of manganefe. Muriatic folu- The fetation of cerium in muriatic acid was clear, and had re^deferj-oliTby onl>r a ljSht rofy tin£e- To Separate it from the lime, if there ammonia. were any, ammonia was added, when the folution, having been diluted with but a fmall quantity of water, congealed into a femitranfparent gelatinous mats, which it was neceflary to agi- tate with a great deal of water, before it could be gotten out of the bottle. The precipitate being wafhedand calcined was very com pa6r, and had a brilliant fracture. The liquor thus decompofed by ammonia contained lime, as appeared on precipitating it with oxalate of ammonia. Oxalate of ceri- At the inftant when the oxalate of cerium is precipitated by ammonia it is white and femitranfparent; but by agitation in the air and deficcation it atfumes a yellowifh colour, and be- comes opake. A remarkable circumflance is, that, if it be boiled with ammonia or potafli before it is dry, it becomes Does cot com- again perfectly white and opake. This is not owing to any combination of the aicalies with the cerium, for when it has been well warned, no trace of them can be difcovered by the mod careful analyfis. Component parts The reiiduum left untouched by the acids was afterwards examined ; when it appeared, that the pureft ore of cerium % UiV. bine with al kalies. from Bafmas contained in 100 parts, Oxide of cerium - 63 Silex - 17 '5 Oxide of iron 2 Lime - 3 or 4 Water 12 98*5 f Cerium, * Mr. Vauquelin analyfed other fpecimens, which were mixed with green aclinote and cupreous pyrites ; but as nothing particular occurred in thefe analyfes, it is unnecefTary to enter into them. f Meflrs. H. and R. fay : {ilex 23 parts, carbonate of lime 5*5, oxide of iron 22, and of oxide of cerium after calcination more than 50. EXPERIMENTS ON CEtUTB. 109 Cerium, like feveral other metals, appears fufceptible of two Cerium has two very diftmft degrees of oxigenation: the oxide which contains GXldes* lead oxigen is white; that which is Saturated with it is of a / fallow red. Though they differ confiderably in certain refpecls, their quantities of oxigen are not very difiimilar, whence they are readily and eafily commutable into each other. The white oxide expofed to the blowpipe foon becomes red,Expofed to the but does not melt, or even agglutinate. With a large propor- j^^pe w^h tion of borax it melts into a tranfparent yellow globule * : with lefs the globule becomes opake on cooling. On heating gently a tranfparent compound of borax and oxide of cerium it becomes milky like a tin enamel. i The white oxide of cerium becomes yellowifh in the open Takes oxigen air, but never fo red as by calcination, becaufe it readily com- *"id fronTthe bines wrth carbonic acid, which oppofes its union with oxigen air. to the point of faturation, and becaufe it always retains a por- tion of water, which diminithes its colour. Cauftic potalh by the alliiUnce of heat deprives the red oxide Alcalies do not of part of its oxigen, and renders it white. This being dried,3 on l ' however, and urged to the ftate of fufion, becomes red again. Alcalies have no other a&ion on it. £ Sulphuric acid diflolves the red oxide with great difficulty. Sulphuric acid Equal parts of it and of lulphuric acid diluted with four times *lth the red ox" its weight of water combine readily when heated : the whole mafs ailuming a cryftalline form and brilliant afpect. On adding frefti acid, and heating them together a long time, a complete folution takes place. This folution being evaporated by a gentle heat cryitallizes in very fmall needles, fome of which are Two fulphates, orange +, others of a lemon colour. If evaporated quickly, nothing but a yellow powder is obtained. 50. The increafe of weight they afcribe to oxigen abforbed by the iron and the cerium. ' ^ * Firft blood-red, then, as the heat decreafes, green, yellowilh, and finally coiourlefs. If it be kept in the middle of the flame it continues as clear and coiourlefs as glafs. Thefe phenomena are With a phof- more evident, if a phoiphoric fait be employed. If two coiourlefs phoric fait, tranfparent globules, one formed with borax the other with a phof- phoric fait, be fufed together, a tranfparent compound is produced, which on cooling becomes opake, and of a pearl colour. Meflls. H. and B. f Thefe Meffrs. H. and B. confider as an acidulous fulphate of cerium at a maximum of oxidation. The 1]0 EXPERIMENTS ON CERITfi. The iulphate of cerium is (bhible in water only by means of an excefs of acid. Its fade is faccharine and acid. With the white Sulphuric acid eafily combines with the white oxide, particu- ox.de. Jarly in the ftate of carbonate. The folution is colourlefs, or with a flight rofy tinge ; of a faccharine tafte without any per- ceptible acidity ; and readily affords white cryftals. Nitric acid with Nitric acid does not readily diflblve the red oxide unlefs the red oxide. affifted by hegL Jf the add bg fuperabundant> {he f0\ut\oh yields white deliquefcent cryftals: if not, no cryftals ate formed, but a yellowifh. fait is formed by deficcation, of which alcohol at 3S° will diflblve half its weight. The nitrate of cerium is decompo fable by heat, and leaves a brick-coloured oxide. With the white. The white oxide unites more readily with nitric acid, but this fait is not more eafily cryftallizable. Its tafte is at firft pungent, afterward very fugary. Muriatic acid. Muriatic acid diflblves the red oxide with effervefcence. The folution cryftallizes confufedly. The fait is deliquefcent, foluble in an equal weight of cold water, and in three or four times its weight in alcohol. The flame of this folution acquires no colour from the fait, but if agitated, white, red, and purple points appear ir^it *. Oxigenatrd mu- Oxigenated muriatic acid has no aclion on the red oxide, but riatic acid. diflblves the white, without yielding to it any of its oxigen. Carbonic acid. The oxide of cerium unites eaiily with carbonic acid. The mod Ample and ready method of forming this compound is to decompofe a folution of the nitrate or muriate of the white oxide by fatu rated carbonate of potafli, when a very white precipitate will be formed with effervefcence, which is very light, and on drying atfumes a fliining filvery appearance. Hidro-fulphures Sulphurated hidrogen does not combine with cerium : but ieparate^iron hidrofulphures may be employed fucceflively to feparate any iron that may be mixed with it ; for, when this is the cafe, the firft portions of hidrofulphure will throw down from the folution of cerium a greenifh precipitate till no more iron remains. Tartarous acid. The white oxide will unite direclly with tartarous acid, but requires an excefs of the acid to render it foluble f . Mr. * When this folution is concentrated it burns with a yellow fparkr ling flame. MefTrs. H. and B. f MefTrs. H. and B. have obferved, as well as Mr. V. that, if the .' EXPERIMENTS ON CERITE. 11 [ Mr. Vauquelin made feveral unfuccefsful attempts to reduce Reduaion of this metal ; at fir ft he ufed the oxalate made into a pafte with ^ metaI' fat oil. However, having mixed tartrite of cerium with a very fmall quantity of oil and lamp-black, he put it into a crucible of charcoal bedded in fand in an earthen crucible, and heated it for an hour and half in a forge furnace. A metallic globule fcarcely as large as a pin's head was now left in the coal, but no other trace of cerium could he difcovered, though the fand was examined with the utmoft care. None of the fimple acids acted on this globule, but it dif- The globule cx- folved, though with extreme difficulty, in aqua regia, after being triturated. The folution was reddilh, and exhibited unequi- vocal marks of iron : but it likewife gave evident figns of the exiftence of cerium, both by its faccharine tafte, and by the white precipitates which tartrite of potato, and oxalate of am- monia threw down. The metallic globule too was harder, much more fragile, more fcaly in its fraclure, and more white than pure caft iron. As from thefe experiments cerium appears to be volatile, a Volatile, but fimilar mixture with the addition of borax was heated in a blinw^it fruit- porcelain retort, to the neck of which a porcelain tube was lefs. adapted. Whether from the infufHciency of the heat however, or from the metal being volatilized without adhering to the neck of the retort, no trace of fublimate was found. But feveral very fmall metallic globules remained in the retort, ad- hering to a black varnifh formed by the borax. There were fame of thefe globules about the upper part of the veflel, to which apparently they had been fublimed by the force of the fire; but all thefe globules together would not have amounted to a fiftieth part of the cerium employed. the faits of cerium, decompofed by tartrite of potafh (till contain Simple and read/ traces of iron, the iron remains difiblved in the liquor, particularly method of free-* if a flight excefs of tartrite be employed. Accordingly they have Jng cer^ ob_r -\ propoled this method as the beft and fimplf ft for freeing the cerium taining the ox- from iron. The procefs they recommend for obtaining pure oxide "*e Pure« of cerium is, todiflblve in nitro-muriatic acid any quantity of cerite, carefully fele&ed and thoroughly calcined. To filter the folution, neutralize it by cauftic potafh, and then precipitate by tartrite and potafh. The precipitate well wafhed, and afterward calcined, is pure oxide of ceriunu Abpaft 112 CONSIDERATIONS ON COLOURS. IX. Abjlracl of a Memoir, entitled Confederations on Colours, and feveral of their fingular Appearances; read at the Clafs of Mathematical and Phyfical Sciences of the National Jnjlitute, March, IS05, by C. A. Prieur *. Object of the memoir. Begins with the coiouis refus- ing from a mix- ture of rays. For which we are indebted to Newton. Preliminary re- quisites. Complementary colours. VJ'LJR author here endeavours to account for feveral pheno- mena, which appear to him never yet to have been properly explained : or rather im% his object to exhibit a general theory, by means of which all cafes of coloured appearances, even the moft extraordinary, may be referred to certain principles. He lets out from the known opinions concerning the various Ipecies of luminous rays, the colours refuliing from a mixture of feveral of thefe rays taken at different parts of the folar Ipectrum, and among others the very remarkable cafe, where (he rays are fo chofen, that their union produces on the organ of fight the fenfation of whitenefs, even if two forts of rays only be employed. ^ For thefe ideas we are indebted to the difcoveries of the immortal Newton, and they flow immediately from the me- thod he has propofed for determining what colour would be obtained from a mixture of certain quantities of other given colours. If we would thoroughly comprehend what pafTes in the feeing of colours, it is indifpenfable in the firfl place to obtain a familiar acquaintance .with the (hades comppfed of feveraf iimple rays; to acquire precife ideas of black and of white, and of the complication thefe introduce into coloured appear- ances; and more efpecially to underiland the relation of co- lours, which, taken two and two in a certain order, are capable of forming by their union ,white, or if you pleafe any other compound lint. Two colours having this kind of relation to each other are reciprocally termed amiplementary colours: one of thefe being given, the other may be determined with more or lefs preciiion by various modes of experiment, calculation, or fimple reason- ing; and the confederation of them applies very ufefully to a great number of cafes, as will be feen farther on. * Tranflated from the Annales de Cbiinicy Vol. LIV. p. 5, April, 180j. 3 We CONSIDERATIONS ON COLOURS. US We here pafs over many particulars, which perfons verfed in the fcience of optics, or habituated to the practical applica- tion of colours, will eafily fupply. Befides, the fubfequent part of the memoir, of which we have undertaken to give an account, will furnifh an opportunity of repeating what is moft ueceflary for underftanding thefe fubjecls. After thefe preliminaries the author proceeds to obfervations Contrafts. on contrafts. He employs this word to characterize the effect of the fimultaneous vifion of two fubflances differently co- loured, when brought near together under certain circum- iiances. Contrail: then is here a companion, from which re- sults the fentiment of a certain difference, great or fmali. It is pretty generally known, and painters in particular are well aware, that a coloured fubftance occupying a fpace of little extent, and placed near or furrounded by a given colour, has not the fame appearance as in the neighbourhood of another colour: but whence arifes this difference ? Before we attempt to anfwer this queftion, let us make an •elfential diftin&ion. The colours in queftion muft be either homogeneal, that is formed of one fort of rays only; or com- pound, that is formed of a mixture of different rays. In the firft cafe, it muft be confefTed, we are ignorant, Contrafts of whether the approximation of different fimple colours would fin?ple colours 1 r r not yet exa- produce any alteration in their refpecVive appearance. As mined. we feldom have an opportunity of feeing exhibitions of co- Jour of this kind, and it is not eafy to arrange fuch at will, no experiments have yet been made on their contrafts. The iubjecl, however, is well worth iludying. \ As to compound colours, and fuch are almoft all thofe of Its effecl pro- natural or artificial fubflances, as our author (hews in the luc^. by^b' ftracting from a courfe of his paper, the new colours exhibited by contraft are colour the rays always conformable to the tint that would be obtained by ab- a"aIog°us to ftracting from the colour proper to one of the fubftances the wjth it. rays analogous to the colour of the other. Thus if" we place on red paper a flip painted orange-colour, Orange on red the latter will appear nearly yellow: on the contrary, the appeari yellow > fame ftrip placed on yellow paper will appear nearly red. If on yellow, red $ we place it on violet paper it will refume a yellowiih tint, on violet, yel- but different from the former ; and laftly, on green paper it lo ' 3 t> " " on green, an- ivill appear red, but in a different degree. ether red; 1 Vol. XII.— October, 1805. I The \l± CONSIDERATIONS OV COLOURS. bcctufe orange The explanation of thefe inftances by the rule propofed is x-Tf ftttfckle. ^*^7' & we foPF^* ^e wangc-colour of the little Grip to be compounded of all the rays except blue, which is commonly the cafe. A multitude of combinations of colours thus placed upon one another, bring out toe colour of contrail indicated by the O-mtnft motf- rule above laid down ; but there are feveral circumftances ficd by ciicum- lnat refJder (he effed more fir iking, or modify the refult. Degreeof light. Sometimes it depends on the degree of light by which the colours are obferved. They may be illumined uniformly, or fome more than others. The quantity of light entering fimul- taneoufly into the eye from ihe whole field of view, has like- Many contraftj wife its influence. £f die colours form feveral furrounding at once borders to each other, as a fcries of circles decreating.in tize and placed one upon another would do, they will act reci- procally on each other. At every junction there will be on each fide a border coloured by tfie contrail of the adjacent tint, Thefe borders will be of greater or iefs extent in proportion to the brigfatnefs of the colour. The effect, of a single one may be fuSicient to deaden or annihilate all the reft. EH'e& increased The colours of contraft will appear like wife with greater by Bight fatigue yjyjdnek aft^ having obferved them a few moments, or if the coloured fubftances be ihaken a little, io that they may pafs tlowly over the retina. It feems as if a certain fatigue of the eye, either inftantaneoufly with regard to the intensity of the light, or more (lowly by a prolonged vifion, concurred to But not by ex- produce the appearances in queftion. But an exceflive fatigue t&mct of the organ would produce a degeneration of the colours be- longing to another mode. ColoaronAe We ought not therefore to refer to contraft thofe impref- rcrma afterex- ^ons ,nentioned by Jipinus, which are propagated in the eye light, netfroxa with a certain duration, and a particular period or tints, when cootraft. we nave footed ftedfaftly on a very brilliant light, as that of the fun. Bufibn'cacel- But the colours termed by HufTmi accidental, on which dental colours ut Scherfer has written an interefting efiay, belong to the clafs of contrafts, or at lead conftantly obferve the fame law. toVnwed feaiows Coloured Jhadows are another phenomenon of the fame kind, •f the Awe «a- Count Rumford has eftabliOied this fa& beyond queftion in CONSIDERATIONS ON COLOURS. 1 15 wo effays, where he has treated the fubject in a very pleating manner.* Mr. Prieur thinks, that Ihofe appearances of the folar light alfo light received through a hole in a coloured curtain, which General loured curt "* Meufnier had remarked on account of their Angularity, are tain j alio to be afcribed to contrail. With this too he affimilates°Pals j feveral cafes of colours difplayed by opals, or, to fpeak more generally, by bodies including perceptible opake parts dtffe- minated through a tranfparent fubflance. In the fame way olddufton paper he explains the colours under which the grayith dull collected ° ' by age on papers, or oh coloured fluffs, appears; and he and bluenefs of draws the fame inferences with refpecl to the blueifh appear- c e veins» ance of the veins of the human body. Helikevvife propofes a new method of rendering the colours of contrafl very fenfible, more fo than even by the known procefs of accidental colours, and nevertheleis without occa- (ioning any extraordinary fatigue of the eye. This lad circum- stance is of no fmall confequence, for every one mud be aware, that fo delicate an organ cannot be flrained by over exertion without danger. This method confifts, the obferver being in a room with a Method of ren- good light, in placing againil the window the coloured papers, ^r^lenSe!**3 on which he means to obferve the contrails in the manner above mentioned. The coloured paper ferving as the ground will then poflefs a degree of femitranfparency, while the little ilip of a different colour placed upon it is more opake, and in the fthade, on account of the double thicknefs of paper: thus the colour produced by the contrafl is rendered much more flriking. From this arrangement loo refults the Angularly linking Slip of white effect of contact of a little flip of white paper applied fuc- f^£j°pa pe°r" celfively on paper, glafs, and cloth of a given colour. When glafs, &c the tranfparent body is red, the opake white appears blueilh green; if the ground be orange, it is decidedly blue; 6n a yellow ground, a kind of violet ; on a crimfon ground, green, &c. ; always correfponding exactly to the complementary colour. On this it mull be obferved, that, according to the rule al- Explanation, ready mentioned, if we abflract from white, which is a com- * See his Philofophical Works, Vol. I, p. 319, and following. I 2 pound 116 CONSIDER ATIONS ON COLOURS. Refleftcd light rauft be avoided pound of all the coloured rays, the red rays for example, th« remaining pencil ought to appear a very pale blueifh green-: but, as in the experiment above the little white flip is in the (hade, the black hence arifing may be of a proper degree to deftroy the effect of the white, and then the blueifli green ap- pears of a lively tint. The fame reafoning is applicable to the cafe of" all the other colours. To obtain the full effect in repeating thefe experiments, we mutt lake care, while procuring a favourable light, to guard againft the reflection oT adjacent bodies, and againft double coloured fringes. Thus when the bright light tranfmitted through the window furrounds the tranfparent paper, it may very fenfibly augment the bright nei* of the colour of contrail, or injure it by introducing another tint, according to the colour of the body under observation. We have it always in our power, however, to get rid of this fupercompofition, by taking a piece of black cloth or pafteboard to malk the object thus incommoded, or by looking through a blackened tube fo as to confine the field of vifion to the neceffary extent. This knowledge of contrail may be ufefully applied to thofe arts, which are employed on the fubject of colours. The painter is aware, that it is not a matter of indifference what colour is placed near another: but when he is acquainted with the law, to which their action on each other is fubjected, he will know better what to avoid, and how to difpofe his tints, fo as to heighten the brilliancy of that which he withes to bring forward. Contrafling them together in fuccefiion likewife affords us valuable indications of their nature and composition. This the author himfelf has put in practice with advantage in his manufactory of colours and paper-hangings. . White appear- Thefe confederations on contrails led him to the examination anceofaco- 0f a ver f1PgU|ar cafe, which Mr. Monge has mentioned and loured body J . . ... through glafs of treated with his ufual fagacity *. This ca(e is the white ap- the fame hue. pearance, which a coloured body fometimes exhibits when viewed through a glafs of the fame hue. There remained fome uncertainty relpecling the circumftances actually neceffary for producing this effect : thefe our author determines by par- ticular experiments, and he enumerates thole which have a favourable influence or the contrary. His conclufion is, that. How, Ufeful in the arts. * Annaki dc Cktmie, Vol. III. whea CONSIDERATIONS ON COLOURS. JJ7 when we have the perception of whitenefs in thefe cafes, it is owing folely to the action of contrafh, by which the impref- dion of the colour is deadened or annihilated ; while that of a certain degree of brightnefs (till fubiiOs, and is noticed from the oppofition of a greater degree of obicurity. This manner New definition of confidering the fubjeCt leads to a new definition of whitenefs0* whitenefs. which has certainly nothing in it incontinent : white is ivith re/pecl to us the Jen/at ion of light, ivhen no particular colour pre- dominates in it, or is perceived in it. In the fubfequent part of his memoir our author particularly Further fubjeijfc coniiders the colouring of different opake and transparent o{ in and correct ^j^^1 and extend others by farther refearches, new experiments, and profound reflections, is an ample field of improvement ; and this be will attempt, if bis powers and bi9 leifure wiH permit. it would fikewife be t>fef«?, as well as juft, ii> ghe at the feme time an abftraft of what we owe to the genius of the great Newton, who opened the career in fucb an admirable snanner, and to thofe phitofophers who have discovered new fec%, or removed difficulties. Greater precision alfo mould be introduced into the language which we employ refpe&ing colours, proportionate to the increafeof our knowledge, and the actual ftate of the arts and fciences. Laftly, in a fubjeel like the prefect, it would not be too much to add ihe resources €>i algebra and geometry to the treasures of experiment, and if pofiible to the advantages of a better method. Jieport made by (lie Phyficai and Mathematical Clafs of the Injii- tute in Anfxer to the Quefiion, whether thofe Manufactories, from which a difugreeable Smell arifes, may 'prove injurious to Health. Bead in the Sitting of January, 1805, by Mejfrs, Guyion-Mouveac and Chaptal.* HE minifter of the home-department has confulted the clafs on a queflion, the folution of which is of effentiai import to our manufacturers. QgdEon, The object is to determine, whether the vicinity of certain manufactories can be injurious to health. J»snif«rtJrnce, The folution of this problem mud appear of the more con- sequence, as, from the confidence which the decinons of the Inftitute naturally merit, it may hereafter form the bans of * Tranflated from the Annates de Chimie, vol. LIV. p. S6, for April, 18 OS. deci&ons INJURIOUS MANUFACTORIES. \23d djecifions in a court of juftice, when fentence is to be pro- nounced between the fate of a manufactory and the health of our fellow-citizens. The folution is fo much (he more important, it is become fo much the more necefTary, as the fate of the mod ufeful efta- blifhments, I will lay more, the exigence of many arls, has depended hitherto on fimple regulations of police; and that fome, driven to a diftance from materials, from workmen, or , t from confumers, by prejudice, ignorance, or jealoufy, conti- nue to maintain a difadvantageous ftruggle againft innumerable obftacles, by which their growth is oppofed. Thus we have feen manufactories of acids, of fal ammoniac, Manufactories of Pruffian blue, of beer, and of leather, fucceffively banith- obJe INJURIOUS MANUFACTORIES. that the emanations from them appear to be fo much the' Iefs dangerous, as the fubftances which undergo putrefaction are Iefs humid: in the latter cafe, aconfiderable quantity of carbonate of ammonia is evolved, which imparts its predominant charac- ter to the other matters volatilifed, and corrects the bad effects of fucli as are deleterious. Thus the decomposition of fter- coraceous matters in the open air, and in places the (ituation * and declivity of which allow the fluids to drain off, and that of the refute of the cocoons of the filk-worm evolve a vaft quantity of carbonate of ammonia, which corrects the virus of fome other emanations; while the very fame fubftances, decompofed in water or drenched with this fluid, exhale fweet- i ifli and naufeous miafmata, the refpiration of which is very dangerous. ->d clafs. The numerous arts in which the manufacturer produces and diffufes in the air, in confequence of his procefies and by the help of fire, vapours more or lefs difagreeable to breathe, con- ftilute the fecond clafs of thofe we have to examine. Thele, more interefting than the former, and much more intimately connected with the profperity of our national in- dustry, areftill oftener the fubject of complaints brought be- fore the magistrate for decifion, and on this account have ap- peared to us to require more particular attention. We will begin our examination with the manufacture of acids. jltffo. The acids that may excite complaints of the neighbours againft their preparation are the fulphuric, nitric, muriatic and acetous. „ , , . .. The fulphuric acid is obtained by the combuftion of a mix- bulphuriC acid* * J ture of fulphur and nitre. It is very difficult in this procefs to prevent a more or Iefs obfervable fmell of fulphurous acid from being diffufed around the apparatus, in which the com- buftion is performed; but in manufactories (kilfully conducted this fmell is fcarcely perceptible within the building itfelf, is not dangerous to trie workmen who refpire it daily, and can give no reafonable foundation for complaint to the neighbours. When the art of making fulphuric acid was introduced into France, the public opinion was ftrongly expreffed againlt the fiift eftablifhments for the purpofe; the fmell of the match with which we kindle our fires contributed not a little to ex- aggerate the effect that mult be produced by the rapid com- 2 bullion KK|UK COIFS If \N\jrXCTOR4ESi 121 tnsttrcn of feverai hundred weight of brimftone; but men"* fears on this head are now fo much allayed, that we fee fe- veral of thefe maiitifa&or ies profper in peace i« the raidft of our cities. The di filiation of aqua for lis and fpirit of fait, m other A«j«a forts* m words, of the nitric and muriatic acids, are not more danger- {P*'A °* **•' ons than that of lulpluirtc acid. The whole of the procekts performed in an apparatus of gfafs or earthen- ware, and it is nnqueftionably (he great intereti of the manufacturer to dirai- nifc the volatilization or tofs of the add as mach as potfibie. Yet, let him pay wh a tever attention he will to this, tl»e air breathed in the manufactory is always impregnated with tire fraeH peculiar to each of theie adds; but you may Tefyhe there freely and fafely, the men who work in it daily are not at all incommoded by it, and the neighbours would be very muds in the wrong to complain- Since the manufactories of white lead, of verdigri«, and of Vonegtu fugar of lead have increajed in franco, the demand tor vine- gar has been enlarged. When this acid isdiiliffed, to lit it for forae of the purpofes D?fc$e**3aB- for which it is ufed, it dilfufes to a diihnce a very ftrong fmeliS*1"* of vinegar, in which there k no danger; but when a foiution of lead la this add is evaporated, the vapours aflame a fweet- ith character, and produce in thofe who reipire them confianthr ah1 the effects peculiar to >the emanations of Jead itteJf. Hap- pily thefe elfeels are confined to the people who work in the manufactory and are unfelt by thofe who dwell in the vici- nity. The preparations of mercury and of iead, fbofe of copper, Miners V®- antimony, and arfenic, and the procefles of gilding on metals, Pw*^on% -*«* are none of them without fome danger to the perfons who re-~ fide in thofe manufactories, and are concerned in tUe opera- tions; but their effects are bounded by the walls within which they are carried on, and are dangerous only to the perfons concerned in the manufactories. It is an object well worthy the attention of chemifts, to investigate the means of prevent- ing thefe injurious eflfe&s, and indeed many of the inconvent- encies have already been prevented by the help of chimneys, which convey the vapours into the air out of (he reach ©f rel- pfrationi and at prefect the whole attention of adminiflraiion ought 128 Pruflun blue, and fal ammo- niac. Few injurious to health. Caution to magiftrates. They fhouM not Jiften too readily t© complaints. INJURIOUS MANUFACTORIES* ought to be confined to directing fcience toward the means oF improvement of which thefe proceffes are fufceptible with re* gard to health. The fabrication of Prufiian blue, and the extraction of car* bonate of ammonia by the diftillation of animal fubftances in the new manufactories of fal ammoniac, produce a large quantity of fetid vapours or exhalations. Thefe exhalations, it is true, are not injurious to health; but as it is not fuflieient lo conftitute a good neighbour, not to be a dangerous one merely, but not even to be a difagreeable one, they who un- dertake fuch manufactures, when they have to feek a (ituation for them, mould prefer one remote from any dweiling-houfe. But when fuch a manufactory is already eftablilhed, we would be far from advifing the magiftrate to order its removal: it would be fufficient in fuch cafes, to oblige the manufacturer to build very high chimneys, that the difagreeable vapours pro- duced in thefe operations may be diffipated in the air. This is particularly practicable for the fabrication of Pruffian blue, and by adopting it one of our number has continued to retain in the midft of Paris one of the moft important manufactories of this kind we have, againft which the neighbours had already leagued. . In the report we lay before the clafs we have thought it our duty to attend only to the principal manufactories, againft which violent clamours have been raifed at divers times and places. It is eafy to fee, from what has been faid, that there are but few the vicinity of which is injurious to health. Hence we cannot too ftrongly exhort thofe magiftrates who have the health and fafety of the public committed to their charge, to difregard the unfounded complaints, which, too frequently brought againft different eftablifhments, daily threat- en the profperity of the honeft manufacturer, check the pro- grefs of induftry, and endanger the fate of art itfelf. The magiftrate ought to be on his guard againft the pro- ceedings of a reftlefs or jealous neighbour; he mould carefully diftinguifh what is only difagreeable or inconvenient from what is dangerous or injurious; he mould recollect that the ufe of pit-coal was long prefcribed, under the frivolous pretence that it was injurious to health; in (hort, he mould be fully aware of this truth, that, by Iiftening to complaints of this nature, not only would the eftabli foment of feveral ufeful arts in France be INJURIOUS MANUFACTORIES. l2£ he prevented, but we fhould infenfibly drive out of our cities the farriers, carpenters, joiners, brafiers, coopers, founders, Difagreeabte weavers, and all whofe occupation is more or lets difagreeable°cc"PatIon,s. , . ,. ^ r .,, i ■ n fanftioned by to their neighbours. For certainly the employments jufttimc. named are more unpleafant to live near than the manufactories mentioned above, and the only advantage they enjoy is that of ancient practice. This right of toleration has been efta- blifhed by time and neceffity ; let us not doubt therefore, but our manufactures, when grown older and better known, will peaceably enjoy the fame advantage in fociety; in the mean time we are of opinion, that the clafs ought to avail itfelf of this circumftance, to put them in a particular manner under the protection of government, and declare publicly, that the manufactures of acids, fal ammoniac, Pruffian blue, fugar of Manufactures lead, white lead, ftarch, beer, and leather, as well as flaugh- neaith. ter-houfes, are not injurious to the health of the vicinity, when they are properly conducted. We cannot fay as much for the fteeping of hemp, making Injurious rnan*- catgut, layftalls, and in general eftablifliments where a large fdftures* quantity of animal or vegetable matter is fubjected to humid putrefaction. In all thefe cafes, befide the difagreeablefmell they exhale, miafmata, more or lefs deleterious, are evolved. We muft add, that, though the manufactories of which we Manufactures have already fpoken, and which we have coniidered as not in- not lnJll"ou$ J r require fome re* jurious to the health of the neighbourhood, ought not to beftrictions. removed, yet adminiftration (hould be requefted to watch over them ftrictly, and confult with well-informed perfons for pre- ferring to the conductors the mod proper meafures for pre- venting their fmoke and fmell from being diffufed in the vici- nity. This end may be attained by improving the proceflfesof the manufactures, raiting the outer walls, fo that the vapours may not be diffufed among the neighbours; improving the management of the fires, which may be done to l'uch a point, that all the fmoke (ball be burnt in the fire-place, or depoiited in the tunnels of long chimneys; and maintaining the utmoft cleanlinefs in the manufactories, fo that nothing mall be left to putrify in them, and all the refufe capable of fermentation be loft in deep wells, and prevented from any way incommoding the neighbours. We (hall obferve too, that when new manufactories of New raaaufac* Pruffian blue, fal ammoniac, leather, ftarch, or any other ar-tones* Vol. XII.— October, K tide ISO INJURIOUS MANUFACTORIES. tide by which vapours very inconvenient to the neighbours, or danger of fire or explofions are to be eftabliflied, it would be wife, juft, and prudent, to lay down as a principle, that they are not to be admitted into cities, or near dwellings, without fpecial authority; and that, if perfons neglect to comply with this indifpenfable condition, their manufactories may be ordered to be removed without any indemnification. Summary. It follows from our report, 1 ft, that catgut manufactories, Jayftalls, fteeping of hemp, and every eftablifhment in which animal or vegetable matters are heaped together to putrify in, large quantities, are injurious to health, and ought to be re- mote from towns and every dwelling houfe: 2dly, that ma- nufactories where difagreeable fmells are occafioned throqgh the action of fire, as in the making of acids, Pruffian blue, and fal ammoniac, are dangerous to the neighbours only from want of due precautions, and that the care of government (hould extend only to an active and enlightened fuperinlend- ance, having for its objects the improvement of their proceffes and of the management of the fire, and the maintenance of cleanlinefs: 3dly, that it would be worthy a good and wife government, to make regulations prohibiting the future efta- blifhment of any manufacture, the vicinity of which is at- tended with any eflfential inconvenience or danger, in towns or near dwelling-houfes, without fpecial authority previoufly obtained. In this clafs may be comprifed the manufactories of poudrette, leather, and ftarch ; foundries, melting houfes for tallow, (laughter houfes, rag warehoufes, manufactories of Pruffian blue, varnifh, glue and fal ammoniac, potteries, &c. Such are the conclufions which' we have the honour to lay before the clafs,* and addrefled to government, with invita- tion to make it the bale of its decifions. * Thefe conclufions were adopted by the Inftitute. Fdfti AMERICAN ALLIGATOR, ]3l XL Fafa relative to the Torpid State of the North American Alligator. By Benjamin Smith Barton, M. D. *. IT has not, I think, been remarked by the generality of the writers on natural hiftory, that the North American Alligator pafTes during the prevalence of cold weather, into the torpid ftale. This however, is unqueftionably the cafe in fome parts of the continent. Mr. Boflu, a French writer, after telling us that thefe Account by animals are numerous in the Red River, one of the weftern y branches of the Miffiffippi, fays, " they are torpid during the cold weather, and lie in the mud with their mouths open, into which the fifti enter as into a funnel, and neither advance nor go back. The Indians then get upon their backs, and kill them by ftriking their heads with hatchets, and this is a kind of diverfion for them f. Dr. Fofter, the tranflator of the work, obferves in the pre- ceding patTage, ou to judge : A cylindrical veflel was turned out of wood, having its tides 0.5 inch thick ; its height four inches, and its diameter two. It has a moveable wooden top or cover perforated with a hole in its centre a little more than an inch in diameter, into which an iron cylinder of one inch in diameter could be eafily introduced. This cylinder is fupported by a flight flanch or (houlder-piece, and can be taken up by means of a firing at- tached to its top. When the iron bar is in its place, its flat lower extremity is 0.5 inch diflant from the bulb of a delicate mercurial thermometer D E, which is fixed by wax, in a hole perforating the cylinder near its bottom. This thermometer, which was made by the late Ramfden, has a tube as fine as a human hair, and is bended to a right angle, fo that its bulb and part of its flem lie in the axis of the wooden cylinder. This fliape was preferred, becaufe the ftem could be little affected by the caloric tranfmitted by the fides of the veflel, till after the bulb was acted on by the caloric of the iron bar, A variety of experiments were performed with this apparatus Into various 11 - in the following manner: The temperature of the room being ,wids in fuccef- ftea(liiy 67o p. during the trials, a kettle of water was kept fion at 67* F. ,...-' . . & T , o , a cylinder of boiling over the fire : Its temperature was between 21 lu and metal at *ia° 212°, and into this the cylinder of iron was futfered to re- main. ON FLUIDS. 137 main, at each experiment, for 15 minutes. The liquid to be and the rife of examined, and all the apparatus (but the iron bar), were, ^^lachkiM each experiment, afeertained to be at 67°. The liquid was neath, was ob- poured into the wooden veffel, till it could rife 0.1 inch on (*r.vtd in threc the fide of the iron cylinder when in its place: The wooden top was put on, and the iron was drawn out of the kettle of boiling water by means of the attached firing, and inftantly let down through the hole of the cover. The time the ther- mometer took to rife through three degrees (to 70p) was ac- curately marked by means of a flop-watch, and the refults of my experiments on feveral fluids are exhibited in the fol- lowing TABLE. Table of refults, 1. Liquids. Minutes. Seconds. Waler, - 7 .5 2. Milk of a Cow, 8 25 3. Proof Spirit, - 8 nearly 4. Alkohol. London Pharm. 10 45 .5. Tranfparent Oiive Oil, 9 50 6. Mercury, - 0 15 7. Solution of Sulphate of Iron, one part of Salt to five of Water, ... 8 0 8. Saturated Solution of Sul- phate of Alumine, 9 40 9. Ditto Solution of Sulphate of Soda, - 6 30 10. Aqua Posafs. Puree. Lond. Pharm. - 8 15 11. Saturated Solution of Sul- phate of Soda, but the Liquid not touching the Iron Cylinder by 0.1 Inch, or nearly fo, 19 20 As the water in the firft experiment was employed at a The tempera- temperature above 42°, it could not affea the thermometer by t«re.wa» always J too high to pro- any change of denfity ; it may therefore ferve as a ftandard duce adefcend- to compare the other liquids. With regard to the differences inS current i« err i , . ,,„ ■ .... water by heat- ot a tew leconds, we need not infill on it as indicating any ;ng. material difference between the conducting power of the differ- rent fubftances ; becaufe the eye may not be able to mark it inftantaneoufly ; but where this difference amounts to nearly a quarter 138 ON FLUIDS. a quarter of a minute, much more when to feveral minutes, we may fairly conclude, that there is a difference in conducting power. In ah thefe experiments the fides of the apparatus fhould have produced equal increments, had this been the caufe of the rife of the thermometer ; and it is evident that currents downwards could not affect it. That the fides of the veffel could not communicate the temperature to the thermometer, nor even the radiant caloric affect it in the manner obferved, the eleventh experiment (which by the way arole from an error in the mode of conducting the trial with fulphate of foda) fuffi- ciently demonftrates. From an inflection of the table, it will be feen, that the aqueous folutions of different falls differ ma- terially from each other in the celerity with which caloric is pro- pagated through them. I attempted to meafure the conducting powers of feveral of the weaker acids, but I was foon convinced that their action on the iron might invalidate the accuracy of the refults. The fluids arc It will be unneceflary to obferve that if we find the thermo- propercon uc- meter reqUjr;ng different times for its elevation, in fuch cafes, we muft afcribe it to the conducling powers of the medium between it and the heated body. If I am not deceived, we may conclude from what I have above adduced, that liquids as well as folios are conductors of caloric ; that the tranfmifiion of it through them follows a par- ticular law depending on the properties of the particular liquid, but which is not in the exact ratio of any of their mechanical properties, though nearer that of their dcnjlty than any other. The Count's Such, Sir, are the principal arguments that feem to militate wdUxplained againft Count Rumford's hypothefis, which he has, with that by the flow con- ingenuity which diftinguifhes his refearches, applied to the *f fluids*^" y* fo!ut'on °f many important phenomena of nature. Thefe, its negation. however, may be equally well explained by fuppofmg liquids V ,-ry flow cur- very bad conductors of caloric ; and, if the currents caufed in "nt*£!1"Pk*ln liquids ^y changes in temperature, have even a very inferior Cbcicre of velocity to what he fuppofes, we may, I think, account iutri- Chamouni. ciently well for the appearance he obferved on the Glaciere of Chamouni, which he propofes as a left of his opinions, by the decreafe in denfity of water while its temperature de- fcends from 42° to 32°, (a facr which the Count's late expe. rir.ients confirm) without affenting to his opinions with regard tQ ACCOUNT OF A FEROCIOUS BEAST. 139 to the non-conducung power of fluids. An examination of (his would, however, extend farther this already too long letter; but if you deem fuch an enquiry interefting, it may be the fubjeel of a future communication, I am, Sir, Your's with refpecl, T. S. TRAILL. %* As this letter did not come to hand till above a fort- night after its dale, and the verbal defcription is very clear, jt was not thought neceffary to poftpone it for engraving the, puthor's fketch,— N. XIII. Indian Account of a remarkably fir ong and ferocious Beaft, ichich (they fay) exified in the northern Parts of the State of New York about two hundred Years ago. Collected and communi- cated* by Mr. John Heckewelder. 4- HE jagifhot (or naked animal, or bear, as fome of the Account of the Indians call it) was an animal much fuperior in fize to the^V."1"1*1 , ' r called jagifho by Jargeft bear. It was remarkably long-bodied, broad down itsthe American. fhoulders, but thin, or narrow at its hind legs, or juft at theIndians* termination of the body. It had a large head and a frightful look. Its legs were fliort and thick. Its paws (the toes of which were furnimed with long nails or claws, nearly as long as an Indian's finger) fpread very wide. Except the head, the neck, and the hinder parts of its legs, in all which places the hair was very long, the jagiftio was alrnoft naked of hair; on which account the Indians gave it the name of " naked." Several of thefe animals had before this time been deftroyed by the Indians, but this particular one had, from time to time, deiiroyed many of the Indians, particularly women and chil- dren, when they were out in the woods getting nuts, digging roots, &c. or when they were working in the fields. Hunters when fall purfued by this animal, had no means of efcaping * To the Editor of the Philadelphia Medical and Phyfical Jour- nal, whence this is taken. ~ f The Indian name of this beaft or animal* from J40 ACCOUNT OF A FEROCIOUS BETAST. Account of the from U except where a river or lake was at hand, by plunging calfed jj^Who by 'n'° ,ne waters> ar»d Swimming out, or down the dream to a the American great diftance, they effected their efcape. When this was the n jans. cafe, and the bean1 was not able to purfue his intended prey any further, he would fet up fuch a roaring noife, that every Indian who heard it trembled with fear. This animal preyed upon every beaft it could lay hold of. It would catch and kill the largeft: bear, and devour it. While the bears were plentiful the Indians had not fo much caufe to dread the jagifho; but when this was not the cafe, he would run about in the. woods, fearching for the track or fcent of the hunters, and follow them up. The women became fo much afraid of going out to work, that the men aflembled to deli- berate on a plan for killing him. This beaft had its refidence at or near a lake, from which the water flows in two different ways (or has two different out- lets), one northerly and the other foutherly. The Indians being well informed of this circumftance, a refolute party of them, well armed with bows, arrows, and fpears, made to- wards the lake". They ftationed themfelves on a high per- pendicular rock, climbing up the fame by means of Indian ladders, and then drawing thefe ladders up after them. After being well fixed, and having taken up with them a number of Hones, the Indians began to imitate the voices and cries of the various beafts of the woods, and even thofe of children, in order to decoy the jagifho thither. Having fpent fame days in this place without fuccefs, a detached party took an excurfion to fome ditlance from the rock. Before they had •reached the rock again, the beaft had gotten the fcent of them, and was in full purfuit of them. They, however, regained that pofition before he arrived. When he came to the rock, he was in great anger, fprang againft it with his mouth wide open, grinning and feizing upon it, as though he would tear it to pieces * * * *. During this time, numbers of arrows and ftones were difcharged at him, until at length he dropped down and expired. His head was cut off, and was carried in triumph by the Indians to their villages or fettlements on the North River, and was there fixed upon a pole that it might be feen. As the report of the death of the animal fpread among the neighbouring ACCOUNT OP A FEROCIOUS BEAST. 141 neighbouring tribes, numbers of them came to view the head Account of the and to praife the vidorious Indians for their warlike deed. caHfcd'jagSfco by N. B. The Mahicanni claim the honour of this acl. the American Indians. Remarks by the Editor. The preceding traditional accounts of the Indians, con- cerning the " naked beafr," are in fome refpe&s, fo very ex- travagant, that they may perhaps be deemed altogether un- worthy of any attention. I muft confefs, however, that I cannot but confider fuch traditions, though imperfectly handed down to us, and evidently disfigured by fable, as entitled to the notice of the naturalift and philofopher. That fuch an animal as the Jagifho i> defcribed to have been, has ever exifted in the (late of New York, may perhaps admit of a rational doubt ; but that the Indian tradkion relates to fome remarkable animal that is no longer to be feen in the country which it is faid to have inhabited, I think there is good reafon to believe. What this animal was, at what period it ceafed to be feen, and what was the more pure account of the Indians concerning it one hundred years ago, I do not pretend to determine. Poffibly the Indian tradition refers to the large animal, (I mean an individul of the fame fpecies,) fome of whofe bones have been found in a cavern in the back parts of Virginia ; the animal of which mention is made in the flrft part of this Journal*. Is is true indeed that the Indian accounts of the activity of the New York animal are not very favourable to the idea, that the animal was Mr. JerTerfon's Megalonyx, which I have fuppofed belonged to the order of Tadigrada, comprehending the Sloth, the Armadillo, and others. What is faid of the claws of the Jagirtio may be thought to favour the notion that this was really the Megalonyx, or Megathe- rium. But I would not be underftood to place any depend- ance upon the minute or defcriptive circumftances which are mentioned in the Indian tradition. Nor indeed do I think it at all probable that the Megalonyx (as it is called) or any of the fpecies of elephants whofe exuviae abound in various parts of North America, have been feen in a living ftate in this Continent, within the period of two, or even twice two hundred years. * Seaion Third, p, 152, 154. SCIENTIFIC 142 SCIENTIFIC NEWS. SCIENTIFIC NEWS, Sfc. Death of Profejfor Claproth. Khprotfc. fc30ME of the foreign journals have announced the death of the celebrated Klaproth of Berlin, who, for the benefit of the Sciences, continues in good health in his fixty-fecond year. Mr. Juftus Claproth, Profetfor of Jurifprudence in the Univer- sity of Gottingen, well known for feveral learned works on that fubjecr, died on the 10th February laft, in his feventy- feventh year. Agronomical Prize, Lalande's prize The medal founded by de Lalande for the beft agronomical given to Har- work, has been adjudged by the National Inftitute in its fitting of April laft, to Mr. Harding, for his difcovery of the laft new f planet. That able aftronomer has been appointed to the di- rection of the Obfervatory at Gottingen. ding Neiv Mufical Inftriunent* New mufical A Polifli clock-maker named Maftoufky, arrived at Berlin, inftrument. a^ the beginning of the prefent year, with the intention of ex- hibiting a new ftringed inlirument, of his invention. Not- wilhftanding a variety of advertifements, he did not fucceed in attracting the public notice; and he determined to exhibit the inftrument at a concert previous to his departure. About 300 auditors attracted by the names of Himmel and Seidien, who were to perform, attended, and towards the end of the concert nearly half the number retired. The artift proceeded to ex- hibit his Kcelifon, which is the name he gives the inftrument. Itconfifts of a found-board, on which the ufual fyftem of .wires of the piano are fixed. Between thefe wires are fmall wooden cylinders, which being „put into motion, communicate their vibrations to the wires. The tones are fo foft and enchanting that the harmonica cannot equal them, the forte and piano are given in every imaginable gradation, and the whole effect was no lei s furprifing than unexpected, and the maker Huhn re- ceived orders tor a number of the inftruments. The SCIENTIFIC NEWS. 143 The prefent article is taken from Millin's Magafui Encyclope* diqite, who does not fay whether the wooden cylinders were moved In rotation or otherwife, nor how they were applied and preffed againft the firings. The leading fact of this notice feems to be, that there are certain kinds of wood, and perhaps certain refinous or other matters to be applied to them, that will produce the effect of a bow upon wire firings in a fuperior manner. It is indeed probable, that we do not yet pofTefs much knowledge of the art of producing tones by the powerful expedient of bowing, or light friction; and mechanics have (till an ample field for applying this method with force, pre- cision, and rapidity to the more compounded inftruments. Saverien. On the 23th of May laft died Alexander Saverien engineer Death of of the French marine; who has been ftxty years known to the avenen* fcientific world, for his writings on navigation and the theory of building, rigging and maneuvering fhips. He has written accounts of the infiruments for making obfervalions at fea ; a marine dictionary ; a dictionary of the mathematics ; a dic- tionary of architecture; an hiftory of modern philofophers, and an hiftory of the progrefs of the human underflanding. His works indicate a confiderable fliare of talent and very ex- teniive knowledge. For many of the laft years of his life he was poor and infirm, and was much indebted to the cares of a fervant who continued with him from motives of attachment. He died at the age of eighty-five, leaving behind him a widow Iikewife very aged and in want. Pure and beautiful Centfe. Mr. Van Mons informs us, that, if lead afhes be diftblved ?\\xz and beau- ft -i fufficient quantity of dilute nitnc acid by the help of a tUui cerufc" gentle heat, filtered, and precipitated by chalk in impalpable pow ler^ the precipitate, when v. afhed and dried, will be the [Vurei: and mofi be iititul cerufe pofiibie. The queftion .which dtFers itfelfon \\ is occafion, is whether it could be afforded at a reatonable price. Chromate 144* SCIENTIFIC NEWS. Chr ornate of Lead and of Silver. Chromate of Count Mouflin Poufchkin has diflblved both the red lead fpar fcad and of filver ancj chromate of diver in nitric acid, by adding a little fugar y a fmall black fly found in it. Obfervations made on the fame Day on Grains, Difeafed grains were always found to be full and plump with- Difeafed grains out any aperture ; the fine ikin that holds the flour very green, c cn e * yet all black within ; the external furface of the black matter covered with a white concretion, perhaps the faccharine matter of the wheat. Sound grains found in difeafed ears, all the difeafed ears fmelt fifby. Obfervations made on the Straw. The difeafe always attacks the portion of the ftraw that Difeafed ftraw. peeps beyond the (heath leaf near the joint, and evidently commences at the pores, as old ftraws will (hew; but the fungus cannot, I think, be the caufe of the difeafe; becaufe < ^ where no fungi have taken root, the corn is compleatly cor* rupted. Thefe fungi grow it is true, fafteft on difeafed ears, probably becaufe when the ear is difeafed it draws lefs humi- dity from the draw, fo that the difeafed ears feem to affiit the growth of the fungi, not the fungi the difeafe. In facl, I believe they live on the fuperfluous moifture of the ftraw, or returning fap. On the 27th July Iaft, J 805. I examined at leaft twenty Blighted ears, blighted ears of corn, and could only find one among them *he ftraw not that had the fmalleft degree of rujl, and that only a fpeck r or two on the lower leaf that (heaths the third joint. The • fpots were orange colour and deep purple, and did not occupy Half the diameter of a fpace of three inches long. Upon again examining many healthy plants, I found not Healthy plants pnly their (heath leayes, but even the ftraw eaten away by -^"l the ftr** fome 152 Iwnculatcd plants, and others injured by violence, took no difeafe. Plants gathered -which have the #raw and the grain not in the fame (healthy or difeafed) ftate. Other inftances of found wheat withruftyftrawj and ihrivelled wheat with found ftraw. The ftrlvelled corn was never ii\r\y ripened. BLIGHT IW COJ.1I. fwne infefr, and at the fame time difcovered abundance of the green locuft like infect on the ears; of which, fee the magnified defign, Fig. % Plate IX. Some plants that I had lately innoculated were flill found: other* that I had pinched and bruifed in the upper joint mewed no alteration, but in all refpe&s refembled themoft healthy. > Aug 3rd, 1805, I went to a field of Mr. Oakley's, o Wefton, where the wheat had a general good afpeft ; and felccled and labelled, or1 ears green yet full. No. 1. Sound ears with difeafed flraws. - .■'* No. 2. Compleatly fmutty ears with found draws in every refpeCl. ■ No. 3. A fmutty arid a found ear from the fame rooL The found ear had a fpeck of fungus. No. 4. Ears with crooked tops, others twitted by fpiders ; others with crooked beards, fhort ftalks and long ; yet all oi them full of grain, green and found. No. 5. Ears half fmutty, viz. on one fide all the way up. No. 6. Ears half flagged, (flagged means here thofe that fhew only the flteleton of the ear and the crooked upper flalk from early blight, all but the bare poles being blown away) thefe ears were half flagged and half covered with grains. No. 7. Bare ftaggs, but with quite fine found draw. LaflJy ; in Auguft and September, 1805, at Allcombe near Minebead, j collected out of a field juft reaped, two bundles which with all the others I flill keep as proofs of my after- tions: One all of found wheat with all their upper flalk? very much covered with the ruft of Sir Jofeph Bank's, defcrip- tion, and the other all of black and thrivelled ears, yet all found in the upper ftalk. Thefe latter mentioned flalks, I think, throw great light. on my ultimate conjectures drawn from every observation through the whole feafon; viz. they prefent ihnvelled, blighted. grainy and exhibit fhort ears, beeaufe on examination they were, evidently never fufficiently expofed to light and heat : for, aH their ftraws though clean were green, not yellow as thofy of ripe wheat ought to be, and their fmoaky miferable ap- pearance (not having the lead fmell of the ftfhy fmutf) could only arife from their humble fitualion below the other ear.-, where air, fun, and light was deficient ; in fact, they never ripened properly. The ftraw remained green, and the fan- probably r BLIGHT IN CORN. 358 probably returned inftead of being intercepted by the drying of the upper joint; and to me it now appears to be a fair conjecture, that what is generally called blighted corn, or What is cal!c4 thofe ears that produce fo many fhrivelled grains, and whichfeemS1o be'corit we are called upon to feek a remedy for, is nothing more than prematurely the effea of a practice of late much recommended, viz. *oreaPed> from 1 ... avarice or igno« reap early, a practice not only promoted by the Miller, who rerance. eager for the new corn to come to market, but by the avarice of the Farmer, who fears that by letting it ftand too long the grain may fall in price, and reduce his profits; and, what is ftill more unfortunate, by fome agricultural writers of great reputation, who recommend it as (topping the progreis of the ruff, forgetting that the fun only can effectually deftroy that fuppofed evil, by well drying the ftraw. Far be it from the writer of thefe few remarks todifcourageft Is often ad- any attempt at faving in a remarkably wet feafon, or in re-J^j* c oreap markably wet fituations, wheat that has pafled the period ufually productive of ripe corn. He knows that in cafes of laid-wheat in fnady fituations, by reaping, it early, we may apcelerate the ripening of that which other wife would not have ripened at all, by the operation of turning and expofing the (heaves to the fun, and fo make good faving crops ; but what he wifhes to guard againft is, that eagernefs for putting in the fickle originating in the motives before alledged ; for, reafon- Argument In tng from analogy do we not always find, that in all other feeds ^"^1° aCC that are to be gathered, thofe alone are plump, found, and full of their proper flour, that are fuffered to receive the utmoft influence of the fun while on the (talk ; and he always thought many years ago, that we were in the habit of being too fearful of the latter feafons ; it is true that late harvefts are expenfive in collecting, but they are generally wcH matured, and the inftanceof barley that may be well faved (for colour can have little to do with the intrinfic value of grain) even as late as November, proves the juflice of the obfervation ; fruit gather- ed too foon, difappoints all views of profit or pleafure, and we might, he thinks, as well attribute the flirivellrng of our apples early gathered to the influence of the apple-tree mofs, as the (hrivelling of our grains of wheat to a fuppofed blight originating in the fungufes, that have of late fo much alarmed the theoretical agriculturifts, and ceconomifts of our day. X> On |54» COUNT RUMFORD's NEW EXPERIMENTS £onclufion. On the facls expofed I could greatly enlarge, but I think on all accounts it is bed at prefent to offer them in their prefent form to the reafoning faculties of your readers. At any rate they may ferve as data, and if they thou id fail to bring others to my opipion, may aft, I truft, as ufeful ftimu- lants to the further inveftigation of a very curious fubjecVof enquiry, as to what are the nature of the enemies tp the per-. feclipn 0/ pur wheat harvefl. With refpeft and efteem, I am, Sir, your moil obedient humble Servant, G. CUMBERLAND, T£c vicinity of ?• &' J*ougM to obferve, that on the grains of wheat fown th&barberry does near the barberry, I I ad no opportunity of making obferva-* stffedTgr in tions ; but that I have a dried root of wheat now by me, on which there are above 100 draws that are all clean and found, though it grew a few years ago in a garden where barberry bufhes were. II. Experimental Invejiigations concerning Heat. J?yBENJAMiT? Count of Rumford, V.P.R.S. 9c c, (Concluded from Page 75.) Sect. IIL Experiments tending tojhexv that Heat is communis cated through Jblid Hodies, by a Law ivhich is the fame as that uhkk would enfue from Radiation bttxeen the Particles. Objeil of in- AJlAVING made a confiderable number of experiments on. quiry j the laws the paffage of heat through fluids, and through different fub- tion o/heatln ^ances m lne ^ate °f powder, I was curious to afcertain the folids. Jaws of its propagation through folic! bodies, particularly me* tals. I hoped this difcovery would furnifli fome additional data, to confirm or refute the opinions I had adopted concerning hea^ and its manner of acling ; and it will be feen by the refults, that my expectations were not fruftrated. Ha vine ON HEAT AND LIGHT. 155 Having procured two cylindrical veflels of tin, each fixDefcnption of inches in diameter and fix inches high, I fattened them toge- ij?^ gyfindridl (her by means of a folid cylinder of copper fix inches long and tin veflels were an inch and half in diameter, which was fixed horizontally be- "nnefted by a ' / bar of copper. tween the two tin veflels. The extremities of the cylinder pafied through two holes an inch and half in diameter, made for the purpofe in the fides of the veffels, midway between the bottom and top, and were foldered faft in them. ,.^, , JEach of the veffels was made flat on the fide where the cop- per cylinder was fattened, fo that the extremity of the cylinder did not project into the veflel, but was level with the flattened part. This infirament wa,s fupported at the height of eight inches and half above the table on which it flood, by means of three het, two fixed to one of the veflels, and one to the other. One of thefe veflels being filled with boiling water, the pther The veflels -filled with water at the freezing point; as the two extremities of thewith woater> onj cylinder were placed in immediate contacl with thefe twoother at'320. mafles of fluid, a change of temperature mutt neceflarily take place by degrees in all the interior parts of the cylinder. For the purpofe of pbferving this change, three vertical holes wereThe changes made in the cylinder, into which were introduced the bulbs of marked by three A. - ,, ... _ ^ , , 1 • thermometers at three (mail mercurial thermometers. One or the holes was MeqUai diftanees. the middle of the cylinder; the others midway between the centre and either extremity. Each of thefe holes is four lines in ^iameter, and eleven lines and half deep; fo that the bulbs of the thermometers, which are three lines in diameter, were all in the axis of the cylinder. ' ^Io#»uk- When the thermometers were put in their places, the holes were filled with mercury, in order to facilitate the communi- cation of heat from the metal to the bulb of the thermometer. To keep the hot water conftantly boiling, a fpirit lamp wasfhe one water placed beneath the veflel containing it; and to keep the cold ^P1 boiling by water conflantly at the temperature of melting ice, frefh por-oth^ cold "by* tions of ice were added to it from time to time. addition of ice. Tiie thermometers are graduated to Fahrenheit's fcale, the freezing point being marked 32°, and that of boiling water 212". As the flrfl and mod important object I had in view was, to The thermome- team at what temperature the three thermometers would be- ters not noticed till nearly fta- COme tionary. 155 COUNT RUMFORD'S NEW EXPERIMENTS com© ftationary, I did not very carefully notice the progrefs of the thermometers toward this point ; but as foon as they ap- peared nearly flationary, I obferved them with the greateft at- tention for near half an hour. The thermome- To diftinguifh the three thermometers I (ball call that neareft ters diftingui/h- the boi!ing vyater B> thaL jn lhe cejUre ^ and that neareft the cold water D. Experiment, The following are the progrefs and refults of an experiment made the 23th of April, 1804, the temperature of the air being 73* of Fahrenheit. Tabulated re- fttiUa Time. Tempera- ture of the hot water. Tempera- ture marked by the ther- mometer B. Tempera- ture marked by the ther- mometer C. Tempera- ture marked by the ther- mometer D. Tempera- ature of the cold water. R. m. s. J 52 15 — 53 30 — 55 — 56 30 — 58 2 0 0 — 1 30 — 4, — 6 — 9 — \i — 28 Degrees. 212 Degrees. 160 16Q| 161 I6li 162 162 162 162 162 162 162 162 Degrees. 130 131 131% 132 ' 132f 132| 133 . mi 132 132 J 132| 132| i Degrees; 105 105| 106 1 06* 107" 1074 107| 106£ 106 106 § 106| Degrees, 32 .Account of the results that would have fol- lowed the hypo- Chcfil of heat being propagated through bodies by radiation from particle to particle. The particles of fulid bodies are difrant from each other. Before I proceed to examine more minutely the refults of this experiment, I will endeavour to (how thofe refults which it ought to have exhibited, on the fuppotition that heat is propa« gated, even in the interior of folid bodies, by radiations ema- nating from the furfaces of the particles compofing thefe; bodies. * *i < \ On this fuppotition we muft neceiTarily confider the particles thatcompofe bodies as being fepar&te from each other, and even to pretty confiderable diftances compared with the diameters of thefe particles; but there is nothing repugnant to the ad- miflion of this fuppofition ; on the contrary, there are many phenomena which apparently indicate that all the folid bodies with which we are acquainted are thus formed. To CN HEAT AND LIGHT* 157 To fee now by what law heat would be propagated In a folid'ff tne folld the calorific influences of hot bodies, and the frigorific influences of cold bodies, are exactly equal; and as thediftance from B to C is equal to the diftancefrom D to C, while the interval of temperature between Band C = 45°, is the fame as that between D and C=45°; it is evident that the temperature of the particle C, which is in the middle of the cylinder, can be no way affected by the introduction of the intermediate particles B and D. And by the fame By the fame way of reafoning may be proved, that the in- reaion it would troduction of an indefinite number of intermediate particles not be changed . \ by other pani- Would produce no change in the temperature of the middle of des interpoftd. the axis of the cylinder, or in any part of it; and if the intro- duction of an indefinite number of intermediate particles make no change in the flate of a thermometer placed in the middle of the axis of the cylinder, we may conclude that the ther- mometer would remain equally ftationary> if the number of intermediate particles were increafed till they had that proxi- mity to each other which is neceflary to conftitute a folid body. If, inftead of a iingle row of particles in a right line, there were a bundle compofcd of an indefinite number of fuch rows placed fide by fide, forming a folid cylinder, the temperature in the different parts of the line A E would remain the fame. But the tempf.r- From this reafoning we may infer, that the temperatures of ature of a con- tj]e differed parts 0f the cylinder lliould decreafe in arithmeti- tinued folid ' J fhould decreafe cat progreffion from one extremity of the cylinder to the other, from one parti- gut jt js evident, that this law of decrement of temperature arithmetical pro- could take place only in the tingle cafe of the furfaee of the grcflion. cylinder being completely ifolated, fo as to be no way affected onl^when1 the ky the action of furrounding bodies, which is absolutely im- folid is remote poffible* from other yj^ cjrcumftances under which the experiments were made Ourexperiments are very different from Ihofe here taken for granted. The arc always thus bodies influenced. ON HtAt ANtf LlGtiti 159 bodies we fubjedt to experiment are constantly furroundeo! oft all fides by the air and other bodies which act on air inftruments continually, and often in a very perceptible manner; and we can never hope to ifolate a cylinder fo completely that the ap- parent progrefs of heat in its interior (hall perceptibly obey the law we have juft difcovered. In common cafes it deviates wide- ly from this law. As the caufes of this deviation are well known, we will fee Appreciation of whether there be no means of appreciating their effects.. The furface of the cylinder being furrounded by the atmof- The atmofphere pheric air and other bodies, all which are of a known and fen- cylinder, fibly conftant temperature, we may determine the comparative effects of thefe bodies on the different parts of the furface of the cylinder. In thofe parts of the cylinder which are hotter than the air by cooling and other furrounding bodies, the furface of the cylinder will !ts h.otPart a*d » ".""" ', J heating its cold be cooled by the action of thefe bodies ; but if one of the ex- part, tremitics of the cylinder be colder than the atmofpheric air, thofe parts of the cylinder which are colder than the circum- ambient fluid will be heatedby its influence and that of the fur- rounding bodies. We will begin with examining the cafe where the coldeft If. one extre- ^ extremity of the cylinder is at the fame temperature as the fur- be' at ^he tern-1 rounding air. Let us fuppofe then, that the experiment with perature of the boiling water at the one end and freezing at the other be made hotter E ^^ when the temperature of the air is at the freezing point, or 32° of Fahrenheit. In this cafe it is evident that the furface of the cylinder mull the furface every where be cooled by the influence of the furrounding at- Wl'' beevery mofphere. The queftion then is to determine the comparative effects, or the relative quantities of refrigeration or lofs of heat, that mutt take place in the different parts of the cylinder: and in the firft place it is clear, that the hotter a given part of the cy- linder is, the more heat it muft lofe in a given time, by the in- fluence of the furrounding cold bodies; whence we may con-, —but moil fo elude, that the refrigeration of the furface of the cylinder by wheic the ke*: the influence of the air and other furrounding cold bodies muft ** ^* necetfarily diminith from the extremity of lh& cylinder A, which is in contact with the hot water, to its extremity E, which is io contact with the cold, From 160 The change Is in proportion to the difference oi temperature* Whence the temperatures will be in ge- ometrical pro- jgieflion, —and may be reprefented by the logarithmic curve. Figure con- ducted. Comparifon of the theory with the •xperiment. COUNT RUMFORD'S NEW* EXPERIMENTS From reafoning which appears incontrovertible, and which the refults of a great number of experiments appear to confirm, it has been concluded that the celerity with which a hot body placed in a cold medium is cooled, is always proportional to the difference between the temperature of the hot body and that of the medium. Conhdering this conclufion as eitablithed, we may determine a priori what ought to be the gradation of temperatures in the interior of a given folid cylinder furrounded by air, one extremity of which is in contact with a coniidera- ble body of boiling water, while the other is fimilarly in con- tact with cold. We have feen that, if the furface of the cylinder were per- fectly ifolated, the decreaie of temperature from the hotteii extremity of the cylinder A to its other extremity E, which is in contact with cold water would be in arithmetical progrejfion, and it has juft been (hewn, that the decreafe rauft neceflarily be accelerated by the action of the air and other furrounding cold bodies. But the acceleration of the decreafe of temperature in thofe parts of the cylinder which are toward the cold extremity, de- pending on the action of the air and furrounding bodies, muft be continually diminifliing in proportion as the temperature of the furface of the cylinder approaches nearer and nearer that of the air; and hence we may conclude, that if a given num- ber of points at equal diftances from each other, be taken in the axis of the cylinder, the temperatures correfponding with thefe points will be in geometrical progrejfwn. We may reprefent the progrefs of the decreafe of temper- ature by Fig. 2. PL VII. In a right line A E, reprefenting the axis of the cylinder, if we take the three points B, C and D, fo that the diftance* AB, BC, CD, and DE fhall be equal; and, erecting the perpendiculars A F, B G, C H, D I, E K, take A F= the tem- perature of the cylinder at its extremity A, BG=its tem- perature at the point B, and fo of the reft ; the ordinates A F, B G, &c. will be in geometrical progrefiion, while their cor- refponding abfeifles are in arithmetical progreffion ; confe- quently the curve P Q, which touches the extremities of all thefe ordinates muft neceflarily be the logarithmic curve. We will now fee, whether the refults of experiment agree with the theory here exhibited or not. To ON HEAT AND LIGHT. ]fjl To form our judgment with eafe, and as it were at a tingle glance, of the agreement of our theory with the refults of the experiment, of which I gave an account at the beginning of this memoir, we have only to reprefent thefe refults by a fi- gure in the following manner. On the horizontal line A E, Fig. 3. reprefenting the axis of Conftru£il)* of the cylinder employed in the experiment, we will take three ing by a curve>" points, B, G and D ; one, C, in the middle of the axis, being and its ordinate* thefituation pf the central thermometer, the other two, B and a&uaU^obkrv- D, at the intermediate points which the other two thermo- ed. nieters occupied between the middle of the axis and its two extremities; Erecling the perpendiculars A/, B^, C A, Di, and E&, on the points A, B, C, D and E; and taking the ordinate A/== 212, the temperature of boiling water; Bg:=162, the tem- perature indicated by the thermometer B; C /j=132|;, the tem- perature indicated by the thermometer C; Di=106f, the temperature given by the thermometer D; and laftly, E kz± ' 32, the temperature of water mixed with pounded ice; a curve, P Q, palling through the points/, g, h, i,k, ought to be the logaritlunic; that is, fupporing the temperature of the fur- rouudingair to be conftantly at the temperature of melting ice during the experiment. But the experiment in queftion was made when the temper- The curve has a ature of the air was at 78° F. cor.fequently, reckoning fi'om[oijta°Jrcontr8" a certain point, taken in the length of the cylinder, where the temperature was at 78°, to the extremity E, the influence of the furrounding air, inftead of cooling the furface of the cy- linder, heated it; and it is evident, that the curve PQ mull fteceflfarily in this cafe have a point of inflexion. In fact it appears on a funpie infpeclion of the figure, that It is likewife the curve P Q has a point of inflexion ; but we fee likevvife, irreSular* that this curve is not regular. That branch which is concave toward the axis of the cylinder is not fimilar to the adjoining portion of the curve, of equal length, which is convex toward that axis; as it ought to be according to our theory; and even the part of the curve which is convex toward the axis A E, differs fenfibly from the logarithmic, particularly toward its extremity P. It ought neceflarily to differ from this curve, as far asthede- The deviation is vifions of our thermometers are defedive ; but the deviation be- ^j ""^he de- Vot. XII.— November, 180$* M tween feds of ther- mometers. I6t COUNT RUMFORD's NEW EXPERIMENTS (ween the ordinates Kf and Bg, indicated by the refults of the experiment in queftion, appears to me much too confider- able to be afcribed to the imperfection of our thermometers. It differs greatly To fee how far the curve P Q differs from the logarithmic, /cWhe ^^ W6 haVC 0nIy t0 draw a logarithmic curvc R S thr0llgh the points g and i, and we fliall find, that the ordinates correspond- ing to the points A, B, C, D, E. Infiead of being 212* 162<* 1329£ 10S| 32° • Will be - 199.55 162 131 106f 86.35 Difference - -2*45 0 -lj 0+54*35 Afcribed to The very great difference that exifts between the temper- water being a ature of cold water, and that indicated by the refults of the ofdheatdU °r exPenment for tne extremity of the cylinder which was in contact with this water, led me to fufpeel, that it was owing to the quality poiTeffed by water in common with other fluids, which renders it a very bad conductor of heat. —and the cur- ^ lt ^e true> as ^ believe I have elfewhere proved, that rents in the cold.there is no fenfible communication of heat between the adja- Siderabl? m" Cent Particles of a fluid' from one t0 another J and that heat is propagated through fluids only in confequence of a motion of their particles, refulting from a change in their fpeciiic gravity, occafioned by their being heated or cooled : as the fpecific gravity of water is very little altered by an inconfiderable change of temperature when this fluid is near the freezing point, it might have been forefeen, that a folid body a little heated, and plunged into cold water, would be very flowly cooled. Experiment to The refult of the following experiment, which I made with prove this. a vjevv to elucidate this point, will put the fact out of all doubt. When the cold The three thermometers being ftationary, one, B, at 162°, water was brifk- the fecond, C, at I32|°, and the third, D, at 106j°, the thermometers water m contact with one of the extremities of the cylinder were all greatly being ftill boiling, while the water mixed with pounded ice, deprefled. which was in contact with the other extremity, was conftantly at the temperature of melting ice, I began to flir this mixture of ice and water pretty britkly with a little flick, and I con- tinued to ftir it uninterruptedly, and with the fame velocity, for two and twenty minutes. I had fcarcely begun this operation, when I had a proof, that . . ON HEAT AND LIGHT. 16$ that my conje&ures were well founded. The mercury in the three thermometers immediately began todefcend, and did not Hop till it had fallen very confiderably. The thermometer B fell from 162? to 152° ; C from 132^° Quantities of depremon. to 1 1 J.|p ; and D from 106|° to 7Sf°. On comparing thefe numbers we find, that, in confequence of the agitation of the cold water for two and twenty minutes, the thermometer B fell 10° of Fahrenheit's fcale, the thermo- meter C 23*,: and the thermometer D 28°. As foon as I had ceafed to ftir the cold water, the three thermometers began to rife, and at the end of a quarter of an hour they had all reached the points from which they let oat at the beginning'-of this operation. To facilitate the companion of the refults of thefe two ex- Diagram to re* periments, one made with cold water at reft, the other with ^ds?^ the fame water in a (late of conftant agitation, I have repre- fented them in Fig. 4. In the firft place we (hall learn feveral very interefting facls Obfervatlons by iiraple infpe&ion of this figure ; we fhall fee, 1ft. that the j^^18 ^zi progrefs of refrigeration, or, to fpeak more properly, the de- creafe of temperature, was every where much more rapid, when the cold water in contact with the extremity of the cylinder E was agitated when it was at reft. 2dly. That the extremity of the cylinder in contact with this water was conftantly near 30° colder in the firft cafe than in the fecond. • 3dly. We fhall fee, that the progrefs of refrigeration was every where, and in both the experiments, fuch nearly as our theory points out. The decreafe of temperature toward the middle of the cy- linder was fo regular, that it is more than probable the appa- rent irregularities toward the two extremities were occafioned folely by the difficulty which a body of water finds in commu- nicating its mean temperature to a folid, with which it is in contact. The boiling water being in continual motion owing to its Agitation In- ebullition, it had a great advantage over the cold water, which creafed tiie •*• B . . ? ; ' fed* of the boil- was at reit, in communicating its temperature to the extre- ;ng water j^ mity of the cylinder it touched; but I have found, notwith- wife. Handing this, that by agitating the boiling water ftrongly with a quill, and particularly when with the quill I made a rapid M 2 friaion 164? GOtfNT RUMTOHD^S NEW EXPERIMENTS friclion againft the end of the cylinder immerfed in the boi ing water, I occafioned all the thermometers to rife feveral degrees. The difference It-may perhaps be imagined, at fir ft fight of the refults of between the ex- . * ? ... periment and the t,,e experiment, that, as the three thermometers, which occu* theory confirm pied the parts about the middle of the axis of the cylinder, did pot indicate a decreafe perfectly agreeing with the theory, the theory itfelf cannot be true: but a moment's reflection wilt fhow, that this inference would be too hafty, and that the dif- ference between the theory and the refults of our experiments, far from proving any thing adverfe to the theory, ferve on the contrary to render it more probable, becaufe the The refults of fuch experiments can never agree with the thermometers ttteorv> except (he divifions of our thermometers be perfectly are defective. accurate: but it is well known to every one, who has any knowledge of natural philofophy, that the divifions of our ther- mometers are defective. To improve this One. of the objects I had in view in the experiments, of ©"btaTnm'or" wmch * have juft fe»*n an account to. the clafs, and in feveral tance. others, which I intend to make without delay, is to improve the divifion of the fcale of the thermometer, in order to render this valuable inftrument of greater utility in the delicate in- veftigations of natural philofophy. The air thermo- It appears certain, that the increafe of the elaflicity of air t^b* «. TT ky heat is much more nearly proportionate to the increafe of to. temperature, than the dilatation of mercury or any known fluid ; confequently it is the air thermometer we ought to en- deavour to improve, and which mud ultimately afford us the moft accurate meafure of heat, that it is poffible for us to procure. Sect. IV. The Heat produced in a Body by a given Quantity offular Light is the fame whether the Bays be denfer or rarer t convergent, parallel, or divergent. Whether the In all cafes where the rays of the fun flrike on the fur face quantity °f heat 0f an opake body without being reflected, heat is generated, the folar rays be and the temperature of the body is increafed : but is the proportional to quantity of heat thus excited always in proportion to the quan- forbed. *• iliy °f n£nt tnat ^as difappeared ? This is a very interesting queftion, and has not hitherto found a deciiive folution. When Otf HEAT AND LIGHT. \Q$ When we confider the prodigious intenfity of the heat ex- it does not fol- cited in the focus of a burning mirror or a fefcs, we are tempted !°w [j^t™f°£ to believe, that the concentration and condenfation of the folar f0iute power ef rays increafe their power of exciting heat; but, if we examine *}* raYst0 Pr0* , f ,- , ,i. r r i ■ r i duce heat can be the matter more eroiely, we are obliged to cornels', that loch increafed by an augmentation would be inexplicable. It would be 'equally condenfing fo on both the hypothefes, which natural philofophers have formed of the nature of light: for, as it has been proved both by calculation and experiment, that tw^p undulations in an elaftic fluid may approach and even crofs each other, without deranging either their refpective directions or velocities, if light be analogous to found, we do not fee how the concen- tration or condenfation of thefe undulations can increafe their force of impulfe : and if light be a real emanation, as its ve- locity is not altered, either by the change of direction it un- dergoes in paffing through a lens, or by its reflection from the furface of a polimed body, it feems to me, that the power of each of thefe particles to excite or impart heat, mutt necefiarily be the fame after refraction or reflection as before ; and con- fequently, that the heat communicated or excited muft be, in in all cafes, as the quantity of light abforbed. I have juft made Come experiments, which appear to me to Experimental eflablim this fa& beyond queflion. inveftigatkm. Having procured from the optician Lerebours two Ienfes Tw0 convex perfectly equal, and of the fame kind of glafs, four inches in fimiiar were diameter, and of eleven and a half focus, I expofed them at the ufed, fame time to the fun, fide by fide, about noon, when the ffcy was very clear; and by means' of two thermometers, or refer- voirs of heat, of a peculiar conftruciion, I determined the re- lative quantities of heat, that were excited in given times by the folar rays at different diftances from the foci of the lehles. The two refervoirs of heat are a ibrt of flat boxes of brafs to throw the filled with water. Each of thefe refervoirs is three inches ten £un's. ,ifht upon v i i ir ,- .- . flat tin boxes lines and a half in diameter, and fix lines thick, well polifhed containing water externally on all fides except one of its two flat faces, which ai>d blad"ned l i i i i i /- i r > . on their f«r# was blackened by the lmoke of a candle. On this face the faces. folar rays were received in the experiments. Each of thefe refervoirs- of heat weighs when empty 6850 grains, poids de marc, (near a pound troy), and contains 1210 grains of water (about 2 oz. 2 dwts. Taking J()(j COUNT RUMFORD's NEW EXPERIMENTS Taking the capacity of bra is for heat (o be to that of water as 0,11 to 1, it appears, that the capacity of the metallic box, weighing 6850 grains, is equal to the capacity of 622 grains of water; and adding this quantity of water to that contained in the box, we fliall have the capacity of the refervoir pre- pared for the experiments equal to that of 1932 grains of water. The tempera- Each refervoir is kept in its place by a cylinder of dry wood, ter in each was" Qne °^ tne extremities of the cylinder being fixed in a focket ihewn by a ther- in the center of the interior face of the refervoir ; and each refervoir has a little neck, through which it is filled with water, and which after receives the bulb of a cylindrical thermometer, that reaches completely acrofs the infide of the box in the di- rection of its diameter. The two refervoirs of heat, with their two lenfes, are firmly fixed in an open frame, which, being moveable in all directions by means of a pivot and a hinge, the apparatus is eafily di- rected toward the fun, and made to follow its motion regularly, fo as to keep the folar fpectra conftantly in the centers of the blackened faces of the refervoirs. Light admitted In order that the quantities of light palling through the two through equal jenfes fl10uld be perfectly equal, a circular plate of well po- lifhed brafs, in the centre of which is a circular hole three in- ches and a half in diameter, is placed immediately before each of the Ienfes. When the refervoirs of heat are placed at different diftances from the focufes of their refpeclive lenfes, the diameters of the folar fpectra, which are formed on the blackened faces of the refervoirs, are neceffarily different; and as the quantities of light are equal, its denfily at the furface of each refervoir is inverfely as the fquare of the diameter of the fpedrum formed on that furface. Experiment I. Experiment. In this experiment the refervoir A was placed fo near the With equal focus of the lens, between the lens and the focus, that the fdlar'i^ots from diameter of the folar fpedrum falling on it was only \ an inch, the lenfes were or 6 lines, while the refervoir B was advanced fo far before lines diam. ** ^e **ocus> lnat tne fpeftrum was two inches in diameter, or 24 lines. As ON HEAT AND LIGHT. 167: As the quantities of light falling on both were equal, the The denfities of ^ denfity of the light at the furface of the refervoir A was to the \x^St$o{ den.fi ty of that at the furface of the refervoir B, as the fquare light were there- of 24 to the fquare of 6, or as 16 to 1. forc as l6 t0 * 5 I imagined, that, if the quantity of heat, which a given quantity of light is capable of exciting, depended anyway on its denfity, as the denfities were fo different in this experiment, I could not fail to difcover the fact by the difference of time, which it would require to raife the two thermometers the fame number of degrees. Having continued the experiment more than an hour, on a but beth the very fine day, when the fun was near the meridian and Seated fo"qUai ihone extremely bright, I did not find, that one of the refervoirs times. was heated perceptibly quicker than the other. Erperiment II. I placed the refervoir of heat A ftill nearer the focus of the Experiment lens, in a fituation where the folar fpedrum was only 4| lines ^^"ofthc1*'" in diameter, and where blackened paper caught fire in two or fpots were as three feconds; and I removed the refervoir B itill farther from 4lt0 a7» the focus, advancing it forward till the diameter of the fpeclrum was two inches three lines. The denfities of the light at the furfaces of the refervoirs in The denfities this experiment were as 32 to 1 . of the uSht wer* as 32 to 1. The temperature of the refervoirs, as well as that of the at- mofphere, at the beginning of the experiment, was 54° F. = The refervoir A, after having been expofed to the action of The denfeft very intenfe light near the focus of the lens for twenty-four bght afforded . J ,. ,. .r , 1 i. rather lefs heat, minutes forty leconds, was railed to the temperature of 80° F. = 21°4.R. The refervoir B, which was much farther from the focus of its lens, was railed to the fame temperature, 80° F. a little more quickly, or in twenty-three minutes forty feconds. To raife the temperature of the refervoir A to 100° F. =■ 30° •§ R. it was neceflary to continue the experiment for one hour fifteen minutes ten feconds, reckoning from the com- mencement of it ; but the refervoir B reached the fame tem- perature in one hour twelve minutes ten feconds. The progrefs of this experiment from the beginning to the end is exhibited in the following table : Increafes 1<& COUNT RUMFORD'S NEW EXPERIMENTS The general re- ' — — . — , — fults tabulated. Increafes of Tem- Time taken 1 perature, By A. By B* « From 54* to 80° F. 24/ W 23' 40" 80 85 7 45 7 30 85 90 9 55 9 0 90 95 1 3 30 J 3 0 93 100 19 20 19 0 54 100 75 10 72 10 Time of the ex- periment. . Hence light does not give more heat abfolutely by being con- denfed. The rays were convergent in the preceding experiments. This experiment was begun at 7 minutes 30 feconds after II, and finimed at 22 minutes 40 feconds after 12, the iky being perfeclly clear during the time. On comparing all the remits of this experiment, we fee, that the refervoir A, which was placed very near the focus, was more flowly heated than the refervoir B, which was at a consi- derable diftance from it*. The differences of time however taken to heat them an equal number of degrees were very trifling, and I think may be eafily explained, without fuppo- fing the condenfation of light to increafe (qu. diminiih?) its faculiy of exciting heat. In both the preceding experiments the folar rays ftriking on the refervoirs of heat were convergent, and they were even equally fo on both fides. To determine whether parallel rays have the fame power of exciting heat as convergent rays, I made the following experiment. Experiment III. When one vefTel Having removed the lens from before the refervoir B, Ifuf- ScparaHefra^s fered the direa fa>'S of the fu" t0 h]l °U the b,ackened face of of the fun with- the refervoir, through the circular hole three inches and half out interception, ;n diameter in the round brafs plate, which had been conftantly placed before that lens in the preceding experiments. The refervoir A. was placed behind its lens as in the former experiments, and at the place where the folar fpe£irum had fix lines diameter. * Did not the elevated temperature of the fmaller furface fuftain its power of abforbing heat, conformably to the known laws of heated bodies? — N. Having ON HEAT AND LIGHT. | fj(J Having expofed this apparatus to the fun, I found, that the It was heated refervoir B, on which the dired rays fell, was heated fenfibly ™ore T:ck}7 • i , , r • * , • , r , , -. than the other quicker than the refervoir A, which was expoied to the action byafpeftrum of of the concentrated rays near the focus of the lens. 6 ,ines or onc* The temperature of the apparatus and of the atmofphere at diam. P the beginning of the experiment being 53° F. = 9° \ R. the refervoir A required twenty-three minutes thirty feconds to raife it to the temperature of 80* F. = 21° f R; but the refervoir B, which was expofed to the direct rays of the fun, acquired the fame temperature in eighteen minutes thirty feconds. To reach the temperature of 100° F. ~ 30° £ R. took the refervoir A one hour and three minutes, but the refervoir B forty* ("even minutes fifteen feconds only. The following table will fhow the progrefs of this experi- ment from the beginning to the end. Increafcs of Tem- perature. Time taken (^ By A. By B. > From 53° to 65° F. 8' 26" 7' 0" 65 70 4 10 S 15 70 75 5 10 3 45 75 80 5 40 4 30 80 85 7 0 4 45 85 90 7 30 5 45 90 95 10 30 8 0 95 J 00 13 10 * 10 15 100 105 20 0 14 45 53 3 05 «■ ■ ■ ■ - — — ■— • 81 36 62 30 • General reftilts. As a confiderable part of the light that fell on the lens before This difference the refervoir A, was loft in palling through it, it is evident, fenced to lighc ...,/- • iri i bei"g loft in that the quantity received by this reiervoir was lets than that pafijng through received by the refervoir B, which was expofed to the direct the lens, rays of the fun ; and we have feen, that the latter was heated more rapidly than the former. As we know not exactly how much light was loft in palling This experiment through the lens, we cannot determine from the remits of this is not 0° to G5y F. 65 70 70 75 75 80 4' 50" 4 55 5 27 6 13 4' 50" 5 0 5 25 6 15 60 80 21 25 21 30 From ART OF BLASTING ROCKS. 171 .From the refults of all the experiments, of which I have Conclufion. juft given an account to the clafs, we may conclude, that the j^ ^^laJs° quantity of heat excited or communicated by the folar rays is as the light ab- always, and under all circumftances, as the quantity of light that difappears. III. Obfervations on blafting Recks ; tcith an Account of an Improve- ment, whereby the Danger of accidental Explofion is in a great Meafure obviated. By Mr. William Close. From the Author. To Mr. NICHOLSON. SIR, Dalton, Oa. 14-, 1805. JL HE method of confining the force of gunpowder by a co- Practice of blaft- lumn of fand in blafting rocks, has been feveral years ufed in £8^ fandin this part of Furnefs : At one time it was a very favourite prac- tice; but at prefent, from the prejudices or indifference of workmen, or on account of the little danger attendant on working lime-flone in the common manner, it is lefs in repute. About two years ago, fuppofing this method not to be ge- noticed by the nerally known, I drew up a fhort account of it, and fliould au^hor elie- have lent it to the Philofophical Journal, had it not been con- nected with other mifcellaneous matter, which I had given to Mr. G. Athburner, the printer and proprietor of a new edi- tion of Weft's Antiquities of Furnefs, in which work the pro- cefs is defcribed and recommended*. Though * The pafTage alluded to is as follows, p. 393. " In breaking up the loofe rocks upon Baycliff Haggs, after the enclofure of that common, a method of employing fea-Iand, for the purpofe of con- fining the force of gunpowder in blafting, was ufed, which does not appear to be generally known, though it was undoubtedly in ufe in other parts before it was adopted in Furnefs. The method is briefly this : After the excavation is made in the ufual manner with a borer, the charge of powder is poured in j and a priming- ftraw of a proper length, filled with powder, is placed in the hole., having one of its fides near the lower end fo cut or thinned, that the 172 • IMPROVEMENT IN THE Improvement by Though this method is undoubtedly worthy of much alters* sounced." * " *'on* anc* ma^ °^tcn ^e employed with advantage ; yet, when a flrong charge is required, the common mode of ftemming muft be frequently adopted : And as the danger in bJafiing fome kinds of rocks in this manner is very confiderable, I am happy to notice an eafy method of obviating one principal ckute of accidental explofion, which was communicated to me in converfation, a few days ago, by Mr. Thomas Fiftier, a refpectable Hate merchant in this town, who allures me it is infallible, Caufcs of acci- The principal danger attendant on blading, does not con, Tfj£*e?P^fiUs** m liemming uPon t,,e char£e of powder, but in the fubfe- from the friction quent operation of drawing the iron rod, called the pricker, of the iron which makes the channel lor the priming-ftraw! For although ^rawing. *ne collifion of the firft fragments of Hemming fometimes pro- duces an explofton, yet this may be prevented by rjrevioufly ramming a thick cap of paper-, &c. upon the powder; by beating lightly upon the firft pieces of ftone that are thrown into the hole; or by ufing thole materials for Hemming which are leaft liable to give tire, fuch as rotten ftone, pieces of broken pots, or burnt clay. The pricker being hard preffed againft the rock, and in clofe contact wi-th the ftemming, can- not be drawn out by hand, but muft be ftruck out by the hammer, a ftrong piece of iron called a jumper being nrft placed in an eye or loop in the higheft part of the rod, io re- ceive the blows which are given in a proper direction to bring it out of its place. Now it frequently happens, that the fric- tion of the loweft part of the pricker againft the rock fires the powder at the firft or fecond blow. When the explofion happens at the commencement of ftemrning, the workman generally fuftains only a partial injury; but when in this part of the operation, when the powder exerts its whole force, and the charge may partially communicate with the fmall afcending co- lumn contained in the ft raw. After this, the remainder of the ex- cavation is filled, by pouring in dry fea-fand; and the explofion is given, by firing the priming-ftraw in any of the various ways which are in common ufe. " This method has been found to be equally effectual as ftem- ming with any of the common materials ; and where it can be ufed is certainly preferable : it is fafer, Ampler, and more expeditious." difperfe* ART OF BLASTING ROCKS. 173 difperfes pieces of the Mattered rock in various directions, his lite is in the utmoft danger, and his fituation is truly terrible to contemplate. Mr. Fither's improvement is to obviate this danger; and Mr. F.'s expe- confifls in the ufe of a copper rod, or pricker, for making ^ade "fro"^ the hole that receives the priming-ftraw, inftead of one ofwhichisnot iron, which before was every where employed in this part of h^J° fire the the kingdom. In our converfation Mr. F. obferved, that fome years ago, three explofions happened on drawing the pricker, in the courfeof a fortnight, at his quarry in Kirkby Ireleth, and that one man being killed and two wounded, feveral of the work- men were fo intimidated, that they refolved to abandon a place which they confidered as deftined to daily misfor- tunes. It therefore became highly requifite, on feveral ac- counts, to attempt fome innovation for the fecurity and en- couragement of the workmen. In meditating on the caufe of thefe accidents, it appeared moft rational to attribute them to the iron pricker giving fire- by its friction againft the rock, which was a hard blue rag, or w.hin(ione : and from this view of the caufe it was inferred, that fafety would accrue from the ufe of prickers conftrucled of thofemetals which are leaf! difpofed to give fire with ftone. Mr. Fifher, therefore, determined to make trial of copper, and having procured fome implements of this kind, found them to anfwer the purpofe completely. It is now upwards Ample.experl- of three years fince this improvement was adopted, and as no fnce h*s proved explofxon has happened at the end of ftemming in that period, at an extenfive work where accidents were frequent before, Mr. F. considers the means as alraofl infallible ; and is happy to think that many fad misfortunes have been thereby pre- yentedw ' There are eleven flate quarries in Kirkby Ireleth, at feveral of which copper rods are now ufed ; but at others they are not. At one of thefe a fatal accident happened a few months ago, from an explofion upon drawing a rod of iron. Prickers, fuch as ufed by Mr. Fifher, are eanly eonftrueled : A piece of copper being forged to the proper length, ftiape, and thicknefs for the body of the tool, is rivetted to an iron head or loop fimilar to that of the common pricker. Thefe implements, when carefully ufed, are nearly as durable a* thofe of iron. 5 Sand 174 PORTABLE STEAM-ENGINE; Advantage of ( Sand has not hitherto been ufed in blading at the flate quar- ^SroCck.rSeSinries in Kirkby Ireleth. The matters do not think it would fucceed well in their work. I have frequently Teen Mr. Fifher ufe it in limeflone rock near this town : He fays it anfwers the befl in deep holes, but thinks that fand is more liable to be blown out than (lemming. He alfo confiders it as the mofl advantageous method of working, in driving levels, and blad- ing in firm rock, to ufe ftrong charges of powder, that the Hone may be fufficiently broken by the explofion to be re- moved without much affiftance from the hammer, the pick, or the lever : For thus the expedition of the work amply com- penfates for the fmall addition which is requifite to a common charge of powder. I am, Sir, Your's refpeclfully, WILLIAM CLOSE. IV. Defer iption of a portable Steam-engine, invented by Mr. Samuel Clegg*, David Street, Manchejier. Communicated by Mr. Dalton, Lecturer at the Royal Injlitution, fyc. Defcription of a 'A HIS engine is worked by four copper valves in the ufual £«anjrcngi!ie. manner, but the mechanifm for lifting them is very different from any hitherto made : there are no levers employed for opening the valves, and there is no hand gear. The fleam and exhauflion valves are on the fame horizontal plane ; thofe which are vertical to each other are not like thofe hitherto ufed, both expofed to the fleam or both to a vacuum ; but by a iimple contrivance in the conflru&ion of the nozzles, the one is expofed to the fleam while the other has a communica- tion with the condenfing vefTel. From what has been faid it may eafily be perceived, if the two valves be connected to- gether by a ftraight rod, that when this rod is lifted,1 the pref- fure is given to the piflon, and the machine is put into mo- tion ; and if the other two valves be connected in the fame * Late apprentice to Meffrs, Boulton and Watts, of Birming- ham. manner Portable steam-engine. 175 manner and lifted at an appointed time, the engine is kept in Defcription of s motion. The outfide appearance of thefe nozzles may be feen eam"cn8me- at Fig. 1, c c, (Plate IX.) The rods which come out of the bottom of the nozzles are kept tight by vertical ftuffing-boxes, the. whole of which is hid in the drawing by the frame. The next is a new contrivance for producing a rotative mo- tion from a reciprocating one, which not only Amplifies the machine very much, but exceeds the power of the common crank by nearly one-third, in confequence of its acting always perpendicular to the radius of the wheel, which is done by a rack and wheel, as reprefented by Fig. 2 and 3 ; and as this plan of connexion diftributes the power uniformly, of courfe a much lighter fly-wheel is required, which diminifhes friction, &c. Explanation of the Plate. Fig. 1. is a representation of the engine: one of the cor- ner columns A A, which fupports the frame, ferves Iikewife for an eduction-pipe and condenfing-vefTel : the air-pump E is joined to the condenfing veflel by the pipe D ; e is the pif- ton-rod, and though it works out at the bottom of the cylinder, it is as eafily kept tight as if it worked out at the top ; b is a fimilar rod which keeps the rack perpendicular; da are the two radius bars on which the brafles are fixed that fupport the fhaft ; by this contrivance the wheel C eafily moves from one fide to the other of the rack F. Fig. 2. is a view of the rack on a larger fcale, where G re- prefents the wheel and D the fhaft; EE, a Hiding- bar, on which is fixed the fmall roller o, ferving as a connecting link to keep the wheel C always in gear ; for, when the wheel is in gear on the oppofite fide of the rack, the roller o is on the other fide of the plate a a ; but it will perhaps be more clearly underftood by the plan, Fig. 3. where the letters reprefent the fame movement as in the elevation, Fig. 2 : This defcrip- tion may be eafily. underftood by thofe who already pofTefs a little knowledge of a fleam-engine. Manchejler, OH. 5, 1805. Letter |7(J FRAMED TRUSS, V. Letter from Mr. J. C. Horn blower, defer ibing the framed IVork by which the Roof of Clapham Church was raifed to its original Situation, without difturbing the Interior of the Build- ing, %c. To Mr. NICHOLSON. Dear Sir, Framed trufs by &T ^jj ^e a p]eafure to you I know to record the productions ofciupham of genius or fancy in your valuable Work, and therefore I church was have no hefitation in prefenling the inclofed for that purpofe. »ifed, &c It Js the ;nvention of Mr. Watkin Bloore, one of the part- ners of Fothergal and Co. carpenters at Clapham, and was invented to raife the funk roof of Clapham church ; and its application to the purpofe intended, exhibits at once the means and the end that was to be accompli (lied ; as by it the roof was raifed and fecured in the fame procefs, without incom- moding the building with ihoors and fcaffolds, which muft have occafioned confiderable damage to the furniture of the church. The fhaded part of the drawing, Plate X. (hews the trufs, and the lines behind it the conftruclion of the roof. The middle piece in the trufs marked A, is joggled into the king-poft of the roof, and the two fcrews put into action raife it up, and with it the whole of the middle or funk part of the roof, all which is eafily comprehended by the drawing. The drawing, Fig. 3, (hews an improved mode of con- ftru&ing the trufs, by the riders A AAA being framed over the principals B B, by which the raiting fcrews are more firmly iupported in elevating the queen-polls C C in the roof. This muft be a valuable experiment in the art of carpentry, which, confidering how little fcience of it falls to the lot of Us pofleflbrs, cannot be too much regarded. I am, Dear Sir, Your very obedient fervant, J. C. HORNBLOWER. Remark* DRAINING OF LAND. J^ VI. Experiments on draining Land, by John Christian Curwen, Ejlj. M. P. of Workington-Hall, in Cumberland, with an Engraving *, Dear Sir, IViuCH having been faid, in the public Papers, relative Mr. Elkington'a to draining, on the improved method of Mr. Elkington, I beg^^0^"- & r ... ing is apphcaWc leave to offer you feme obfervations refpe£ting it, which have only where the fallen under my notice, and which tend lo prove it can be ap-ftrata are *,ttle . interrupted* plied, with fuccefs only, in fuch parts of the kingdom, as have tew, if any, interruption of the urata. In order to make my- feif intelligible, it may not be improper to explain what is meant by interruptions of the ftrata, or dykes and fitlures, as they Dykes and fif- are denominated in mining countries. They are produced fures* by the fraclureor difunion of the ftrala, and confift moft com- monly of the broken fragments of each fuperior ftrata ; and towards the furface are of (and, gravel, and (tones, which feidom or never fail of affording confiderable quantities of water. Thefe dykes may be approached within a few feet, Thefe Intermp- and afford no water, as will be Teen in two inftances in the t.10"s-.preve£tt£e . r xt • r draining off or plan lent you. No. 3 is a main drain, four feet deep, which the water. patted within a few yards of A, an extreme wet place, and did not affect it. The perfon employed, fuppofed the water to be below him, and brought in a lower level No. 1, which likewife failed. No. 2 was then made ftill lower, but with no belter fuccefs than No. 3, though with more advantage of level. As foon as it croffed the dyke, I C, but before the level was brought up, not being deeper than the main drain, it got a confiderable feeder. This proved that an interrup- tion in the ftrata prevented the water flowing, into a drain, which was of a depth otherwife to have drawn it. Another example occurs in the fame field, at letter B ; which is a funk fence, four feet below the furface of the adjoining field, which was extremely wet within a few yards of the funk * From the twenty-fecond rolume of the Tranfaclions of the Society of Aits j who awarded the gold medal to the author. The plan he refers to is at their houfe. Vol. XII.— November, 1805. N fence. ,178 DRAINING OP LAN©. Experiments of fence. A lower level was fuppofed neceffary to drain this water, and it was obtained at the dotted line. No water of any confequence was got, till it was within a few yards of the funk fence, when a prodigious feeder was cut, and the head of the drain was not fo deep at the time as the funk, fence. Many inftances to the fame effeel might be produced. In finking (hafts in places much troubled with water, it is endeavoured, if circumfiances will permit, to get near a d)ke, which ferves The drains muft as a barrier to the water; and if, in finking, the dyke be not IhVdykVs! Cr°f3cronre l»e water is kept clear off; but if otherwife, the water would be got at any depth, though not in fuch quantities as when near the furface. The fpot of ground, to which I have alluded, has above a dozen dykes, which may be traced from the out-burfts of water. They run in a direction of fouth to north-weft. I have made my drains eaft and weft. In one or two places, I was obliged to run a drain fouth. This pro- ceeds from an arm running from the dyke : but this feldom extends to any di fiance, and they gradually decreafe till they end ; and they rather make an interruption than a breakage of the ftrata, as the ftrata is the fame on each fide of it. In fuch a country, Mr. Elkington could draw no more water than what lay in the uninterrupted ftrata between any two of thefe Description of dykes. The method of making the drain is explained by the ferencT'to the*" engrav,ng- * na^ twenty years ago drained this ground with drawing. ftone drains, from 20 inches to two feet; but their direction having been moftly from north to fouth, and not fufficiently deep, I had got little more than the day water. The feeder which I have now got, might be made applicable to many purpofes. The drains are from two feet to nearly five feet deep. I have made 6000 yards in the laft twelve months; the cutting from 14d. to 18d. per rod, filling 8d. ten and a half fingle cart-loads of ftones, at 9d. each, making the coft 10*. per rod. The expence appears great ; but fewer drains are required, and the work is effectually done. By reference to the plan, it will be feen that the direction of the drains not being able to draw the upper water, I was obliged to extend them. I would advife beginning at the higheft level; for frequently that clears the whole, unlefs fome dykes intervene Springs of water in a contrary direction. I believe that all fprings and out- proceed from t>urfts 0f water proceed from dykes. The extent of thefe. is various. Some may be traced for many miles, and their effects feeq DRAINING OP LAND. 175 feen from the water that appears on the furface. Their origin is fcarcely perceptible, and they thicken to many yards as they are approached. The ftrata on both fides have a more rapid rife or dip, and are of a clofer and harder texture. If thefe obfervations appear to you worthy of attention, you may make what ufe you think proper of them. I by no means with to detract from Mr. Elkington's merit ; but it is not generally applicable; and in counties where the ftrataare much broken* Mr. Elkington's plan will be found to fail. I am, Dear Sir, Your obedient fervant, J. C. CURWEN. Feb. 3, 1801, Mr. Charles Taylor. P. S. The higheft drain is 120 feet above the level of No. 3. A certificate from Mr. William Hoodlefs, farming agent* accompanied this letter, Hating that upwards of fix thoufand yards of drains had been cut, and completely filled, on the farm of John Chriftian Curwen, Efq.; that the firft drains made according to that plan were done three years ago ; and that they ftand completely, and anfwer an admirable purpofe. Reference to Fig. 5, Plate XI. of the Manner in zdiich Mr, Cur wen's Drains are made. The Ioweft part of the drain below E E is twelve inches wide. E E 4 4 are the two fide-ftones of the drain, nearly four inches thick and nine inches high. F 9 is the aperture for the water, nine inches high. £>, the flag or thin ftone over the aperture, and which covers the fide-ftones of the drain. C C, the body of the drain, filled with loofe ftones till within nine inches of the furface. B 9, the top of the drain, twenty-two inches wide and nine inches deep, filled with grafs fod and foil. i N 2 Remarks Jg0 MAXIMUM .DENSITY Or WATER, VII. RetnarLs on a Letter of Mr, f) alt on, concerning the Maximum Dcnfihj of Water ; vdlh an Account of two Experiments of DrK. Hope, tending to Jhevj that it takes place at a Temperature above the freezing Point. In a Letter from T. I. B, To Mr. NICHOLSON. SIR, MrftDalto.fs ^N N°' ^ °f y°Ur Journa1' PaSe 28» Mr* Da,t°n haS Pub" letter. liflied forae remarks upon Count Rum ford's experiments, re- lating to the maximum denfity of water, where he explains the riling of the thermometer in the cup, by obferving that it acquired heat by the proper conducting power of water. This, I fhould think, is by no means probable ; for the con- dueling power of water is not futiicient to produce fuch a rapid effea. The circumftances of the two thermometers by the fide o thei ball and cup, in the Count's two firft experiments, I think are perfectly confident with his principle: the cup, very probably, did overflow, which might have been afcer- tained by a thermometer placed below. In the conclufion of this letter Mr. Dalton exprefles a wifli that Count R. or fome one in pofleffion of a fimilar apparatus, would repeat the Count's firft experiment, with this difference, that the mafs of water mould be at 40° and the ball at 32°, in which cafe, he fays, the thermometer would not be at all affected on the Count's principle; neither would it be affected (on Mr. D.'s principle) if the tenacity of the water counter- acts the force of defcent : and what conclufion could be drawn from fuch a variation of the experiment ? Experiments of The following experiment was made by Dr. Hope, pro- Dr. Hope. feflbr of chemiftry in Edinburgh, to afcertain the point at which water has the greateft denfity, — and it appears to me lo be perfectly decifive. He filled a jar with ice-cold water, and expofed it to the air of a room at 52° : he fufpended in it two very delicate thermometers, one at half an inch from the bottom, and the other at the fame diflance from the furface of the water : the thermometer neareft the bottom was firft affected, and con- - a 5 tinuetf SUPPOSED WELCH INDIANS. JgJ tinned to rife till it reached the temperature of 40°, when vt became flationary : the thermometer at the furface rofe more (lowly, but did not flop till it acquired the temperature of the room (52°)* . vv Dr. Hope, to render this point ftill clearer, expofed water at 52° to the air of a room 32° ; the refult correfponded per- fectly with the former experiment. If you fee no objection to the publication of this letter, by inferring it in your Journal, you will oblige *', Sir, your's, Edinburgh, OB. 10, ISO T. I. B. VIIL Obfirvatiuno and Conjectures relative to the fuppofed Welch Jndians in the wejltrn Parts of North America. Republ/Jlted from the " Kentucky Palladium," with additional Remarks and Conjectures, by the Editor of thC Philadelphia Medical ■and Phj/jlcal Journal f ,, s:x, i%IO circumfiance relating to the biitory of the Wefterri Traditional ac- Countrv, probably has excited, at different times, hitte>gtil ■^0fAmeri« neral attention and anxious curiofity than the opinion, that fuppofed to have a nation of white men, fpeaking tlvc Welch language, reside ^nsated from high up on the Mifotiri. B< tome the idea is: treated as no- thing but the fuggeiiion of bftW i liJJWftiiM and eafy credulity ; vv h i 1 it others regard it as a facl fully authenticated by Indian teitimony and the report of various travellers worthy of credit. The fad is accounted for, ihev fay, b) recurring to a palfage in the hiftory of Great Britain, whieh relates, that feveral years after the difcovery of America by Chriliopher Columbus, a certain Welch prince embarked from his native country with a large party of emigrants; that after forne time, a vefTel ■ * A fuller recount of the late experiments of Dr. Hope witt'toe ififerted when the Edinburgh Tranfa&ions appear. j- Extraaed from that Work, Vol. II. Part I. or 182 SUPPOSED WELCH INDIANS. Traditional ae- or two came back with the account that they had difcovererf tants of America acountry ^ar to lne weftward, and that they fet fail again with fuppofed to have a frefli reinforcement, and never returned again any more. w£tCdfr°m The country which thefe adventurers difcovered, it has been fuppofed, was the continent of North America; and it has been conjectured that they landed on the continent, fome- where in the Gulf of Mexico, and from thence proceeded northward, till they got out of the reach of the hoftile natives, and feated themfelves in the upper country of Miffouri. Many accounts accordingly have been published, within the Iaft thirty years, of perfons who, in confequence either by accident or the ardour of curiofity, have made themfelves ac- quainted with a nation of men on the Miffouri, poffeffing the complexion of Europeans and the language of Welchmen. Could the fact be well eftablifhed, it would afford perhaps the moil fatisfactory folution of the difficulty occafioned by a view of the various ancient fortifications with which the Ohio country abounds, of any that has ever been offered. Thofe fortifications were evidently never made by the Indians, The Indian art of war prefents nothing of the kind. The proba- bility too is that the perfons who conftrucled them were, at that time, acquainted with the ufe of iron : The fituation of thefe fortifications, which are uniformly in the raoft fertile land of the country, indicates, that thofe who made them were an agricultural people; and the remarkable care and fkill with which they were executed, affords traits of the genius of a people, who relied more on their military fkill than on their numbers. The growth of the trees upon them is very compatible with the idea that it is not more than three hundred years ago that they were abandoned. Thefe hints however are thrown out rather to excite en- quiry, than by way of advancing any decided opinion on the fubjeft. Having never met with any of the perfons who had feen thefe white Americans, nor even received their teftimony near the fource, I have always entertained confiderable doubts about the fact. Laft evening, however, Mr. John Childs, of Jeflamine County, a gentleman with whom I have been long acquainted, and who is well known to be a man of ve- racity, communicated a relation to me, which at all events appears to merit ferious attention. Aftef SUTPOSED WELCH INDIANS. ] g$ After he had related it in convention, I requefled him to Traditional ac- repeat it, and committed it to writing. It has certainly fome t°™ of Amc*-ic][ internal marks of authenticity. The country which is defcribed fuppofed to have was altogether unknown in Virginia when the relation was ^^ "on* given, and probably very little known to the Shawneea Indians. Yet the account of it agrees very remarkably with later difcoveries. On the other hand, the ftory of the large animal, though by no means incredible, has foraething of the air of fable, and it does not fatisfactorily appear how the long period which the party were abfent was fpent; though Indians are, however, fo much accuitorned to loiter away their time, that many weeks, and even months, may probably have been fpent in indolent repofe. Without detaining you any more with preliminary remarks, I will proceed to the narration, as I received it from Mr. Childs. Maurice Griffith, a native of Wales, which country he left when be was about fixteen years of age, was taken a prifoner by a party -of Shawnees Indians, about forty years ago, near Voiles Fort, on the bead of Roanoke river in Virginia, and carried to the Shawnees nation. Having ftaid there about two years and a half, he found that five young men of the tribe had a clefire of attempting to explore the lources of the Miflburi. He prevailed upon them to admit him as one of the party. They let out with fix good rifles and with fix pounds of powder a^-piece, of which they were, of courfe, j*ery careful. On reaching the mouth of the Miflburi, they were firuck with the extraordinary appearance occafioned by the inter* mixture of the muddy waters of the Miflburi and the clear tranfparent element of the Mifliflippi. They flaid two or ihree days arnufing themfelves with the view of this novel fight: they then determined on the courfe which they mould purfue, which happened to be fo nearly in the courfe of the river, that they frequently came within fight of it as they pro? needed on their journey. After travelling about thirty days through pretty farming wood land, they came into fine open prairies, on which no- thing grew but long luxuriant grafs. There was a fucceflion €»f thefe varying in (ize, fome being eight or ten miles acrofs fetijtone of them fo long that it occupied three days to travel through 184 SUPPOSED WELCH INDIANS. Traditional ac- through it. In palling through this large prairie, they were t3TstofAmeari>camuch diftrefled for water and provifions, for they favv neither fuppcNfed tohavebeaft nor bird; and, though there was an abundance of fait WakT^ tf°m *PrinSs' tlt'fll vvater was very Scarce. In one of the fe prairies the fait fprings ran into fmall ponds, in which, as the weather was hot, the water had funk and left the edges of the ponds f« covered with fait, that they fully fupplied themfelves with that article, and might eafily have collected bufliels of it. As they were travelling through the prairies they had like- wife the good fortune to kill an animal, which was nine or ten feet high, and a bulk proportioned to its heighth. They had feen two of the fame fpecies before, and they faw four of them afterwards. They were fwift-footed, and they had nei- ther tulks nor horns. After having palled through the long prairie, they made it a rvAe never to enter on one which they could not fee acrofs, till they had fupplied themfelves with a fufficiency of jerked venifon to laft feveral days. After having travelled a confulerable time through the prai- ries, they came to very extenfive lead mines, where they melted the ore, and furnifhed themfelves with what lead they wanted. They afterwards came to two copper mines, one of which was three miles through ; and in feveral places they met with rocks of copper ore as large as houfes. .^.hl . When about fifteen days journey from the fecond copper- 4 mine, they came in fight of white mountains, which, though it was in the heat of fummer, appeared to them to be covered with fnow. The light naturally excited confiderable afto- nilhment; but, on their approaching the mountains, they ilifcovered that, inflead of fnow, they were covered with im- menfe bodies of white (and. They had in the mean time palled through about ten nations iof Indians, from whom they received very friendly treatment. It was the practice of the party to exercife the office of fpokef- ■man in rotation ; and when the language of any nation through which they paifed was unknown to them, it was the duty of the fpokefman, a duty in which the others never interfered, to convey their meaning by appropriate figns. The labour of travelling through the deep fands of the mountains was excetfive ; but at length they relieved them- felves of this difficulty, by following the courfe of a (hallow river, the bottom of which being level, they made their way ip theiop of the mountains with tolerable convenience, Afte* SUPPOSED WELCH INDIANS. 135 After pafling the mountains 'they entered a fine fertile tra& Traditional ac- ©f land, whicli-'havimr travelled through tor levcra! days, they' coant ;)fAinhabi- . , ■ s ,. J / tants of America accidentally met with three white men in the ■ Ittttian oreis. fuopofrd to have Griffith immediately undcrftood their language, as it was ofjg'in:lte,M#t Whether his ideas be correct or not, we (hall probably have a better opportunity of judging on the return of Captains Lewis and Clark ; who, though they may not penetrate as far as Griffith alledged that he had done, will probably learn enough of the country to enable us to determine whether the account given by Griffith be fiction or truth. I am, Sir, Your humble fervanf, HARRY TOULMIN. Frankford, Dec. 12, 1S04-, Additional Obfervatiom and Conjectures by the Editor, THE ftory of a Welch colonization of America has excitetl much curiofity, both in Europe and the United States : By many it is believed, while by others it is thought unworthy of any attention. By reafon of the prefent rapid progrefs of ieU tlement in America, the time cannot be remote when the truth or fallity of this ilory will be completely eftablifhed. In the meanwhile I do not hefitate to conjecture, that no traces -of the defcendants of the Welch prince mil ever be difcovered in the iveftern parts of North America. It ISg SUPPOSED WELCH INDIANS. Traditional ac- It may not be improper (o notice the tale upon wtikh fo count nMnhdb^- aiai>^; perlons jn £ur0pe at leaft reft their hopes of proving, fuppoi.oto have '" the moft faiisfaclory manner, that the Welch have con- originated from tributed to the peopling of America. David Powel, a Welch hiiiorian, informs us, that on the deceafe of Owen Guyneth, king of North Wales, a difpute arofe among his ions concerning the fucceluon to the crown ; and that Madoc or Madog, one of the fons, ** weary of this contention, betook, him felt' -to fea, in queft of a more quiet fettlement */• We are informed, that '* he fleered due weft, leaving Ireland to the north, and arrived in an unknown country, which appeared to him fo defirable, that he returned to Wales, and carried hither ieveral of his adherents and com- panions. After thisneitber Madog nor his companions were ever heard of more. The voyage of Madog is faid to have been-performed about the year 1 170. i have not feeh Bowel's woik, but I learn that this hifto rian, who lived in the reign of Queen Elizabeth, and confe- quently at a great diftance of time from the event which he records, adduces no better authority in fupport of the voyage than a quotation from a Welch poet, '* which proves no more than that he (Madog) had diftinguiftied himfelf by fea and land f /' Some few Welch words, fuch as gu-randa, to hearken or liften, &c. are- very feebly or unfortunately adduced by Powel, as circumftances favourable to the truth of the Welch emigration. When we coniider " that the Welch were never a naval people; that the age in which Madog lived was peculiarly ig- norant in navigation;" that the compafs was then unknown; the dory of the voyages of the Welch prince mult I think be confidered as extremely imptobable. I am of Opinion with Mr. Pennant, that " the raoft which they could have attempted rauft have been a mere coalling voyage." But it asay be faid, we muft appeal to fads ; and that in- dependently: of the verfes of the Welch poet, and the argu- ments of the Welch hiltorian, it feerasnhigbly probable that 3, colony of white people who (peak the Welch language, does actually extft in the weftern parts of North America. * Dr. Robertfon. . \ • • ■•% f Pennant's Artie Zoology, Introduction, p. eclxiii. Sec. I canno^ SUPPOSED WELCH INDIANS. » (#89 I cannot, I rouft confefs, adopt this opinion. I readily allow, Traditional »c* that the relations publifned by Mr. Toulmin and many other JJ^^jjjJ^J perfons, both in Europe and in America, are extremely curious. foppofed to have But thefe relations are very incontinent with one another, ™*inated froni particularly in what relates to the a&ual flate of improvement of the fuppofed vYeHbmen. By Tome we are told they are very tar advanced in improvement; by others that their im- provement is not at all greater than that of the Red-men or Indians of America. At one time, they are faid to be in pof- feffion of manutcripts (and even printed books) at another time nothing of this kind is found among them. It muli be con> fefled that Maurice Griffith's relation is, in feveral refpe&s, more plaufihie than that of any preceding traveller; but it is not unincumbered with inconfiftencies, which I do not deem it neceflary to notice in this place. His aflfertion " that the white men of the Miflouri fpeak pure Welch," even though this afler- tion be qualified by the obfervation that "they occafionally make ufe of a few words with which he was not acquainted," is 40 me one of the moit improbable things that have ever been related of thefe people. His iilence about their religion Is altogether inexcusable. One would (uppofe that a perfon of Griffith's inquifitive turn of mind, would hardly have omitted to make fome inquiries refpecling the religious inflitutions of 4 people, whom he eonfidered as his countrymen. If thefe people be the- descendants of Madog, fomt traces of the Cbrif- tian religion may be expected to be difcerned among them ; for I think it requires many centuries to entirely efface from the memory of a people all veftiges of their religion, efpecially from a people fo tenacious of their language, and fo little dif- poted to intermix with their neighbours, as the Welch Indians are reprefented to be. But Griffith's relation is, I think, worthy of fome attention, I even think it not altogether improbable that future researches will eftabldh the fact, that there does exift in the weftern part,* of North America a race or nation of men, whofe complexion is much faiier than that of the furrounding tribes of Indians, and who fpeak a language abounding in Welch or^ Celtic words. But the complete eftablimment of thefe two points would not prove the eftablimment of the truth of the affertion, that prince Madog had ever made a voyage to America, or that 190 SUPPOSED WELCH INDIANS. Traditional ao that a colony of Celts had at any period prior to the difcoverj/ tantTof' Amerka of America bJ/ Columbus, parted into this hemi fphere from fuppofed to have Britain. W^«tCdfr°m It may be thought, from the flatement publifhed by Dr. Williams and fome other writers on the fubject, that the belief of the exiftence of a race of Welch Indians in America is ge- nerally admitted by the Welch Indians and others. But this is far from being the cafe. The late Mr. M'Gilivray, a man of no inconfiderable powers of mind, and whofe curiofity was by no means confined to his own relatives, the Mufcohge, or Creek Indians, informed me, in the year 1790, that he knew nothing of the exiftence of any white people in the trad of country beyond the Miffiflippi. The following is an extract of a letter (dated Downing, June 14, 1792) from my learned and excellent friend the late Mr. Thomas Pennant of Wales. " My countrymen are wild among the Padoucas, or Welch Indians, defcendants of Madog, now feated about the upper parts of the MiflTouri. I am rather in difgrace, not having the warmeft hopes of their difcovery. Pray what is your opinion and that of your philofonhers ?" In anfwer of the above I wrote a letter, of which the fol- lowing is a part : " I have heard a great deal about the Welch Indians. I very early imbibed your opinion, as delivered in your Arctic Zoo- logy*, and mentioned you on the fubject in a little work f which I publithed in England at the age of * * * *. I do not know whether you have feen that work. I do not mean to bint that it is worthy of your attention. I certainly think there is fome foundation for the ftory; but I have no doubt but the Mrhole affair will turn out very different from a difcovery of Madog's defcendants in America. ■« I have faid, that I think there is forae ground for the ftory. I mall explain myfelf. You know that many of the firft viiitors of the new world were ftruck with the refemblance winch * See the introduction to the work, pages 263, 9CA. •f Obfervations on fome parts of natural hiftory ; to which is prefixed an account of feveral remarkable veftiges, of an ancient date, which have been difcovered in different parts of North America; Part I. London, 1797. fubfifls fit'Pl'OSED WELCH INDIANS, ]$ j fubfifts between fome of the American nations and the Jews. Traditional ac- _ . . . . ,, count of inhabi- Some Hebrew Words were found in this continent, as they tantsof America have been every where elfe. The Americans were now faid fuppofedto have to be the defendants of the Jews and Adair laboured very ^yflTs!^ hard to prove the matter in a ponderous quarto which few people read, becaufe it is big with fyftem and extravagance, though, indeed, it contains fome curious and accurate matter. In like manner, in the languages of fome of the American tribes there are found fome words which are a good deal ana- logous to words in the languages of the ancient Celts. Wafer, who was a very refpeclable obferver, if we confider his oc- cupation in life, mentions the coincidence he found between the language of the Indians of Darien and that of the Highland Scots ; and I could produce inftances of their coincidence. Some Greek words are alfo found in certain of the American languages. I would not ftrain a point lb much as fome writers have, who mention the coincidence which fubfifis between the Greek T/uos and the Mexican Teotl. The word Potoiv- mack, which is the name of one of our great rivers, is a good deal like the Greek Potomos*. Thefe words (perhaps they are accidental refemblanees) have given rife to fome of the numerous theories which we have had concerning the peopling of this great continent : and I doubt not that fome * * * * or perfon who underftood the Welch language, finding Celtic words (a language fpoken by the Welch) among the Ame- ricans, in the fulnefs of his zeal would bring his countrymen among the Padoucas, Apaches, &c. *' Such, I believe, has been the origin of this wonderful ftory. I prefume, that, were an ignorant Highlander to vifit the Darien Indians, or fome other American tribes, he would fancy himfelf among his countrymen, whom painting, e:>- pofure to the fun, &c. he might fuppo.fe had exalted or de* graded to their prefent tinge. I lately converfed with an old Highlander, who faid, that the Indians fpeak the Highland language. Some Highland words were mentioned by him ; * The Abba Molina (in his Compendio de la Hiftoria Civil-del Reyno de Chile, &c. Parte Segunda, p. 334, 335.) has pointed out fome yery ftriking inftances of refemblance between the Greek and Chilefe languages. He has alio pointed out fome refemblance between the Latin and the Chilefe. — February 19, 1805. * * * * one JQ2 Mg. FtOWMAN's SHE£P-F01D* ***" qnkw,ord **** X recollect, the word Uine, w hid) in the Highland language, he faid, fignifies lire; now our Dela-» ware Indians call (ire tti i.day ; the refernblance in found is certainly not final!. The Celts have, undoubtedly, been very widely fjxead over the globe ; I believe they exified in this country, and (.hat their defendants are tome of, the prefenjt tribes *. That Celtic words fhould be found among the Americans, when Celtic words are to be found almoft every where elfe, is not I think to be wondered at." ~ - -:~: • " IX. Account of an improved Sheep-Fold, contrived amkconftrucled hy Thomas Plowman, Efq. of Broom in Norfolk, afid com- municated by him to the Society for the Encouragement of Jlrtsf. Advantages of JL HE model of Mr. Plowman's Sheepfold was forwarded to fold"eW ^ P" Uie Secretary °f lhe Society of Arts fell year with a letter defcribing its properties and conftrucYion. It is made on an improved and very fimple principle, combining many ad- vantages over the old and expenfive method of folding by hurdles ; and as the whole fold can be removed with eafe at all times, it is found peculiarly ufeful in feeding oflf turnips on the land in frofty weather, when hurdles cannot be ufed ; and, as the faving of labour in agriculture is a leading object, he has no doubt of feeing it, in a very few years, generally adopted. Durability. The expence, in the firft inftance, will exceed that of hurdles, for the fame given quantity of (he^p ; but having had one in ufe nearly three years, he is fatisfied the faving will be very confiderable : for, before he adopted this method of folding, he loft. from thirty to forty nights folding in the year, owing to the land being hard in dry feafons, fuch as the * Very confiderable fragments of the Celtic dialects are (till pre- ferved in America ;. particularly, if I do not miftake,. among the Ranticokes and the Katalba cr Katawbas. February 19, .1805. -r The Society awarded the gold medal for this ui'eful improve- ment, and infertcd his account. two MR. PLOWMAN^S SHEEP-FOLD, 193 two laft ; which renders folding almofl impracticable, as Saving of they never can be fet without great labour and deftruction of ^ ,cs» an hurdles. He is alfo clearly of ©pinion, that the (lock of (heep Will be greatly increafed when this method of folding becomes more known ; and that it will enable many fmall farmers to keep from 50 to 100 fheep, who now are deterred from it, greater profit Ira on account of the (mall quantity of feed they have, not an- jceepingflxee*. fwering to keep a man for that purpofe only ; but by this plan, they may keep a boy at 3s. or 3s. 6d. per week, who can at- tend on 100 or 200 (heep, and move the fold himfelf without any affiflance. In heavy gales of wind it frequently happens It is eafily that hurdles are blown down, and the ftieep, of courfe, being r,ab!etobeblov.n at liberty to range over the crops, do incalculable mifchiefj down j which cannot happen with this fold. In fome counties in England, where hogs arc folded, great refills hogs, difficulties are experienced for want of do wage, for them to feed off winter tares, &c. &c. as they root up every flake or hurdle; but from having tried the experiment, the inventor is certain his fold will keep them in, and defies their attempts to difplace it. From this drawing, which correfponds with the model, and from the defcription, it is feen that an aflonifhing quantity of time is faved ; for one man can remove a fold to contain 300 (heep with eafe in five minutes, which, by the old method, frequently takes fome hours to accomplith. Certificates of gentlemen, who ufe thefe new folds, were fent to the fociety, among whom is that of his Grace the Duke of Bedford. When the fold is wanted to be ufed on very hilly ground, Method of plac- it is beft to begin at the top, and work it down to the bottom, Ing it,onhllIJr . grounds. for the eafe of removing it, and then draw it up again with a horfe. This, however, the inventor has never had occafion. to do ; for the land in his county is ploughed in a contrary direction, and the fold is worked in the fame courfe as the ridges. By this mean, the inconvenience is avoided of crofs- ing the furrows, and they are alfo a guide to keep the fold in. a (traight direction. With refpecl to the flieep getting under, he does not re- coiled that circum (lance to have ever happened, nor does he conceive that any land, which is cultivated can be lb uneven as to admit of it. Vol. XII.— November, 180*. O Defcription lQ/t AMERICAN CROW. P ("caption with Dtfcvlption of the Shccpjbld. reference to the drawing. Hale XI. Fig. 1. Shows one divifion or part of this fence twenty-one feet long, and three feet eleven inches high, com- peted of the following parts : A. A top rail three inches deep and two inches thick. B. The upper bar, three inches deep, and three-quarters inch thick. CC, The two lower bars, four inches by three- quarters of an inch, which, with the upper bar, are morticed through the uprights. I3DDD, Which uprights are oak, three inches by two inches. E, The lower bar, three inches. by three. F, An upright bar, with the horizontal bars halved into it. GG, Two oak uprights, three by two inches. Fig. 2. Shows the oak uprights GG. II, The axletree, three inches by three, and three feet between the wheels. I, An oak knee, which connects the uprights, Q G with the axletree, by means of two fcrews and nuts, ' Fig. 3. A plan, in which the axle it is fiiown with two arms KK at right angles to H, which are made to act as pivots to the wheels, when intended' to be moved in a direc-. lion at right angles to the bars. Fig. 4. Is a view of the fame parts defcribed in fig. 3* The wheels marked W, in all the figures, are of cad iron, and coft 3s. 6d. each. — — " • " . ■" "■" ' '■ ■ " " '■"■ ■ ' ' —-»' X. Antzdoies of an American Croiv. By William Bar.tram*. Anecdotes of a IT is a difficult talk to give a hiflory of our crow. And I crow. hefitate not to aver, that it would require the pen of a very able biographer to do juftice to his talents. Before I enter on this fubjeel minutely, it may be neceflary to remark, that we do not here fpeak of the crow collectively, as giving an account of the whole race, fince I am convinced that thefe birds differ as widely as men do from each other in point of talents and acquirements, but of a particular kind of that fpecies, which I reared from (he ncft. * From the Philadelphia Medical Journal, Vol, L part I. He AMERICAN CROW. }$£ He was, for a long time, comparatively, a helplefs depend- Anecdotes of a ant creature, having a very fmall degree of activity or vivacity, xrow* every fenfe teeming to be afleep, or in embryo, until he had nearly attained his finiftied dimensions and figure, and the ufe of all his members. Then we were furprifed and daily amufed with the progreffive developement of his fenfes, ex- panding and naturating as the wings of the youthful phalaena, when difengaged from its nympha (hell. Thefe fenfes however, feemed, as in man, to be only the organs or in ft™ men ts of his intellectual powers, and of their effecls, as di reeled towards the accomplithment of various defigns and the gratification of the paffions. This was a bird of a happy temper and good difpoiition. He was tradable and benevolent, docile and humble, whilft his genius demonftrated extraordinary acutenefs and lively fenfations. All thefe good qualities were greatly in his favour, for they procured him friends and patrons, even among men whofe fpciety and regard contributed to illuftrate the powers of his understanding. But what appeared molt extraordinary, he feemed to have the wit to felecl and treafure up in his mind, and the fagacity to practice, that kind of knowledge which procured him the moft advantage and profit. He had great talents, and a ftrong propensity to imitation. When I was engaged in Weeding in the garden, he would often fly to me, and after very attentively obferving me in pulling up the fmall weeds and grafs, he would fall to work, and with his ftfong beak pluck up the grafs ; and the more fo, when I complimented him with encouraging exprefiions. Hd enjoyed great pleafure and amufement in feeing me write? and would attempt to take the pen out of my hand, and my fpeclacles from my nofe. The latter article he was fo pleafed with, that I found it neceflTary to put them out of his reach when I had done ufing them. But one time, in particular, having left them a moment, the crow being then out of my light, recollecting the bird's mifchievous tricks, I returned quickly and found him upon the table, rifling my inkitand, books, and paper. When he faw me coming, he took up my fpeclacles and flew off with them. I found it vain to pretend to overtake him ; but (landing to obferve his'operations with my fpeclacles, I faw him fettle down at the root of an apple- tree, where, after amufing himfelf for awhile, I obferved O 2 that crow. \Q(} AMEH1CAK CRO*V Anecdotes of a that he was hiding them in the grafs, and covering them wiib Hicks and chips, often looking round about to fee whether I was watching him. When he thought he had fufficiently fecrefced them, he turned about, advancing towards me at my call. When he had come near me, I ran towards the tree to regain my property. But he judging of my intentions by my a&ions, iiew, and arriving there before me, picked them up again, and flew off. with them into another apple tree. X now almoft defpaired of ever getting them again. However I returned back to a houfe a Hltle diftance off, and there fecreting fnyfelf, I had a full view of him, and waited to fee the event. After fome time had elapfed, during which I heard a great noife and talk from him, of which I tinderfiood not a word, he left the tree with my fpe&acles dangling in his mouth, and alighted with them on the ground. After fome time, and a great deal of caution and contrivance in choofi ng and rejecting different places, he hid them again, as lie thought, very effectually in the grafs, carrying and placing over them chips, dry leaves, &c. and often pufliing them down with his bill. After he had finifned this work, he flew «p into a tree hard by, and there continued a long time talking to himfelf and making much noife; bragging, as I fuppofe, of his achievements. At lafl he returned to the houfe, where not finding me, he betook himfelf to other amufements. Having noted the place where be had hid my ipeclacles, I battened thither, and after fome time recovered them. This bird had an excellent memory. He foori learned the name which we had given him, which was Tom ; and would commonly come when he was called, unlefs engaged in fome favourite amufement, or foon after correction ; for when he had run to great lengths in mifchief, I was under the neceffity of whipping him, which I did with a little fwitch. He would in general bear correction with wonderful patience and humility, fupplicating with piteous and penitent cries and actions. But fometimes when chaftifement became intolerable* he would fuddenly ffart off, and take refuge in the next tree. Here he would confols himfelf with chattering and adju fling his feathers, if he was not lucky enough to carry off with him fome of my property, fuch as a pen knife, or a piece of of paper; in this cafe he would boaft and brag very loudly. At other times he would foon return, and with every token of penitence AMERICAN CROW. Jf)7 )K»nitence and fubmiflion approach me for forgivenefs and Anecdote of a reconciliation. On-thefe occafions he would fometimes return crow* and fettle on the ground near my feet, and diffidently advance with foft foothing expreffions, and a fort of circumlocution, and (it filently by me for a confiderable time. At other times he would confidently come and fettle upon my (boulder, and there folicit my favour and pardon with foothing expreffions and carefiing gefticuiations ; not omitting to tickle me about the neck, ears, &c. Tom appeared to be influenced by a lively fenfe of domina- tion (an attribute prevalent in the animal creation) but never- .thelefs his ambition, in this refpect, feemed to be moderated by a degree of reafon or reflection. He was certainly by no means tyrannical or cruel. It mull be confefTed, however, that he aimed to be matter of every animal around him, in order to fecure his independence and his felf preservation, and for the acquifition and defence of his natural rights. Yet in general he was peaceable and focial with all the animals about him. He was the moft troublefome and teazing to a large dog .whom he could never conquer. This old dog from natural .fidelity and a particular attachment commonly lay down near me when Iwas at reft, reading or writing under the (hade of a pear-tree in the garden near the houfe. Tom (I believe from a paflion of jealoufy) would approach me with his ufual carefles and flattery, and after fecuring my notice and regard, be would addrefs the dog in fome degree of complaifance, and Jby words and actions ; and if he could obtain accefs to him, would tickle him with his bill, jump upon him, and compofe himfelf for a little while. It was evident, however, that this feeming fociability was mere artifice (o gain an opportunity to practice fome mifchievous trick, for no fooner did he perceive the old dog to be dozing, than he would be fure to pinch his lips, and pluck bis beard. At length, however, thefe bold and hazardous achievments had nearly coft him his life, for one time the dog being highly provoked, he made fo fudden and tierce a fnap, that the crow narrowly efcaped with his head. After this Tom was wary, and ufed every caution and deliberation in his approaches, examining the dog's eyes and movements, to be fure that he was really afleep, and at laft would not venture nearer than his tail, and jjien by flow, 3 filenr, 198 SEICHES OF THE LAKE OV GENEVA. iiJent, and wary fteps, in a tideways or oblique manner, ipreading his legs and reaching forward. In this pofition he would pluck the long hairs of the dog's tail. But he would always take care to place his feet in fuch a manner to be ready to ftart oft' when the dog was roufed and mapped at him. It would be needlefs (obferves my ingenious friend in the conclufion of this entertaining account of the crow) to re- count inftances of this bird's understanding, cunning, and operations, which certainly exhibit inconteftible demonftrations of aregular combination of ideas, premeditation, reflection,: and contrivance, which influenced his operations. ~ ~ XI. An Account of the Seiches af the Lake of Geneva. By M. Vaucher *.„'.. Sudden and ir- XhE inhabitants of the banks of the lake pf Geneva, de- regular nie and " ' fall of the lake fignate by the name of feiches certain fudden and irregular of Geneva called changes which take place in the level of the waters of the feiches. ° l lake, and have no relation with the regular and annual iff- creafe produced by the melting of the fnows. This phe- nomenon was defcribed at the beginning of the laft century. Fatio de Duilers in the 2nd vol. of Spoil's Hiftory of Geneva; and afterwards by Jalabert in the Academy of Sciences ; Serre in the Journal de Savans, Bertrand, and by De SaufTure in the 1ft vol. of his Travels in the Alps. But though feveral of thefe philofophers have attempted to explain the facl, as we (hall hereafter remark, yet no one has considered it with precifion, and as a general phenomenon. The editors of the Bulletin des Sciences, from whofe excellent ftieet I take the prefent account, have followed Mr. Vaucher, and after- wards prefent the different explanations. The numerous observations of that philofopher have led him to the following general refults. Particular detail 1. The feiches are not peculiar to the lake of Geneva, (hey of the faftsj arealfo obferved in the Lakes of Conftance, Zurich, Annecv, they are obferved " J ... __ . . , _ J in other lakes. IWeut-chatel, and in the lake Major, and there are ftrong reafons to think that I hey exift in moft lakes, though they may not have been fufficiently obferved. * From the Bulletin des Science, No. 96. 2. It SE/CHES OF THE LAKE OF GENEVA. 199 2. It appears, however, to be true, that the phenomenon But moft ,,,..ii c ^ .i l ftrikingly in tbe is more, remarkable in the lake of Geneva than any where lake Le^ai)4 .tflfe that it has been obferved. In fad, the level of the waters of Leman lake have been feveral times oblerved to rife at a given place in the couile of 15 or 20 minutes, three, four, and even five feel, and to fubfide forae lime afterwards, whereas the ftrongeft feiches oblerved in other lakes, have ,been four or five inches in the lake of Coniiance, eighteen lines in that of Zurich, four or five lines in that of Annecy, and only a few lines in the lake of Neuf-Chatel and lake Major. 3. In all thefe lakes, particularly in that of Geneva, the More confide*, feiches are moft fenfible in that part of the lake which 's ^"of efflux, neareft the outlet of its waters. Accordingly they are no more than one or two inches, at the diftance of two leagues from Geneva, and at the extremity near where the lake re- ceives its waters the feiches of the lake of Geneva are not Wronger than thofe of the other lakes here mentioned. 4. In thcfe different lakes they are moft fen fible in places and where the i ,i , , i li fhores are not where the lake is remarkably narrow. farafunder- t 5. The feiches may take place indifferently at all feafons of they happen at the year, and at any hour of the day; but in all the lakes ^™? and it has been obferved, that they are more frequent in the day than in the night, and in the fpring and autumn, than in the winter or fummer. 0. It has been obferved in particular in the neighbourhood but moft ftrik- of Geneva, that the ft ron^-eft feiches take place at the end of '"S1? when th* h r waters are Xhe fummer, that is to fay, at the time ol thegreateit elevation higheftj of its waters. ,^ \.A.# ufa' rj.3fj.The feiches are extremely frequent, but they are ufually a few lines, or at moil only a few inches, in which cafes they cannot be perceived without exact apparatus to obferve the level of the lake. It is from a want of this obfervation that they have been fuppofed to be very rare, as thofe feiches only could be obferved without apparatus which varied feveral feet. 8. The feiches take place without any agitation or motion attended with no af undulation or current in the furface of the fluid. ' _J 9. Their duration is very variable, feldom exceeding twenty anJ do not laft 4jr twenty-live minutes, and often much lets. 10. This 200 SEICHES OF THE LAKE OF GENEVA. theyfecmtobe Jo. This? phenomenon takes place in all temperatures, but weight of the at- m genera' >l refults from very extent! ve tables, that the feiches mofphere, and are more frequent, and more extreme, the more variable the foretelraia. ^ate °^ ^e atm°fphere. Remarkable variations of the barometer have been obferved to correfpond with confiderable feiches, and it is an opinion generally received among the filliermen, that the feiches are a fign of change of weather. In particular, they have been obferved to be very ftrong when the fun comes to thine very ftrongly on a fpot, a (hort time before obfcured by a thick cloud. Explanations by After this expofition of the phenomenon, fome notion may various autiors. ^ forme(j refpecling the value of the different explanations. M. Fatio attributes the feiches to violent gulls of wind which drive the waters into the narroweft part of the lake. Mr. Jalabert attributes them to fome fudden encreafe of the Arve, which falling into the Rhone at a (liort diflance from the lake, and entering the river at a confiderable angle, may in facr, fometimes ftop its courfe for a thort period, and in that manner raife the waters of the part of the lake neareft Geneva ; latily, Mr. Bertrand thinks this phenomenon to be occafioned by electrical clouds which attract the waters of the lake, and produce ofciliations more fenfible, the nearer its oppofite banks may be to each other. Without dwelling on the in- sufficiency of thefe three hypothefis to account for all the different facls before mentioned ; Mr. Vaucher obferves, that the true explanation ought to be two-fold ; namely, general in order to fhew the caufe of thofe left confiderable feiches which are obferved in all the lakes, and over the whole of their fur face ; the other mull be local, and explain why this phenomenon is much more fenfible at the weftern extremity of the lake of Geneva, than in any other known place. Mr. Vaucher With refpecl to the firft, Mr. Vaucher afcribes it to the afcnbes them to frequent variations which are fenfible in the weight of dif- preflure acting ferent columns of the atmofphere, and consequently in the more ftrongly on pretfure it exerts on different points of the furface of lakes *. rakePthan°at the ^e may eau'v conce»ve» that if the weight ol the atmofpheric place of rife. column be fpeedily diminifhed in a given part of a lake, with- * This caufe was hefore indicated concifely by De Sauffure. in his firft vol. of Travels in the Alps. out SEJCHES OF THE LAKE OF GENEVA. £01 out the fame thing happening over the reft of the furface; or ftill more if the weight fhould be augmented upon that remaining furface, the water will be forced to rile in that lafi place, and will again defcend when the atmolphere fliatl have returned its equilibrium. It is known, in fact, that thefe variations of the barometer are fo frequent, that it can never be faid to be exactly ftationary : it is known, that they can be produced by changes of temperature, and De Sauflure has calculated that a diminution of three degrees in the column of air will account for a variation of 0,85 of a line in the ba- rometer. It is known, that thefe variations are mod frequent in mountainous countries in autumn and in fpring, and ptevious to frorms, circumftances which coincide with the greater frequency of feiches at thofe times. This general caufe tends to explain the flight variations of level which are common to all the lakes; it is even of fuch a nature as to be applicable to all extended furfaces, and it is therefore probable, that thefe variations of level likewife take place in the fea, inde- pendant of the flux and reflux, which may have hitherto pre- vented their being obferved. The variations in the weight of the atmofphere may perhaps contribute to thofe fudden and local elevations of the waters of the fea, which have all been indiftinctly confidered as of the nature of water-fpouts. The fame caufe ought likewife to act or. rivers, but inftead of railing or diminilhing their level, it ought, according to Mr. Vaucher, to produce a momentary acceleration or retardation of their courfe; an obfervation difficult to be made, and not hitherto attempted. As to the fecond part of the explanation, namely, that which —and he fup- (liould account for the great intenfity of the phenomenon at pf)fes the Sreat€* i ,*ix ii ^> „„»,- rife in the lake the extremity ot the Leman lake, near Geneva, Mr. Vaucher of Geneva to be recurs to two circumftances peculiar to that lake, and which cau/ed by',ts Ps- are found in a lets degree in thofe of Zurich and Confiance, CU Uf g"re* where the feiches are moft remarkable after thofe of the lake of Geneva; namely, the contraction of a lake in a given place, and the defcent of its waters towards the place of their dilcharge. With regard to the fill} of thefe circumftances, it will be fufficient, if attention be paid to a chart of the Leman lake, to (hew that it is very remarkably contracted at its weft- em extremity, fo that at half a league diftance from Geneva, it has not one third of the breadth of that before Thonon. Now we *2Q£ SEICHE!, OF THE LAKE OF GENEVA. .WC may compare a lake of this form to a fyphon full of water, >of which the branches fliould very much differ in diameter; and it will be evident that if, for example, their inequality being as fourteen to one, the fmalleft branch fliould fuddenly receive by the augmentation of the almofphere a furcharge equal to that which dep relies the barometer one line, it would fall 11 lines, and the water which would be driven into the great branch would raife ,its furfaee only one line; whereas, on the contrary, a furcharge which fliould deprefs the level of the great branch only one line, would raife it for a moment four- teen in the fmaller. The effect would be double if at. the fame time the weight of the atmofphere fliould diminish on one of the branches, and encreafe on one of the other. We may therefore admit that in lakes, the breach:, of which is remark- ably contracted in fome part, the influer.'v »f the variations of the atmofphere to produce feiches will be greater in the narrow than in the wide part. And alfo by cir- A like effect will take place according to Mr. Vaucher, by cumftances at- reafon of the inclination obfervable in that part of the. furfaee tending the _* ; , : ' . fl>wingoff of °* t,ie m^g near the place where.it ducnarges its water. He the waters. remarks that every particle of a liquid on a flope may be con- sidered as folicited by two forces; one which tends to raife it to the level of the iuperior part of the dope or the refervoir, and the other which urges it in the direction of the current. If by the fudden depreffion of the fuperior fluid the current be for a moment fuppreffed, the particle will no longer find jlfelf urged but by the firft of thefe forces, and will rife to- wards its ancient level, and foon afterwards defcend. Now, as we have before feen, all the parts of lakes which have very perceptible feiches have a remarkable fiope; this dope is natu- rally more coniiderable at thole times of the year when the waters are higheft, and thefe are the periods when the feiches are. mod (hiking in the neighbourhood of Geneva, i Singular appear- Independent of the phenomenon of the feiches, the lake of ance which £,eneva and mod other lakes afford two other lingular pheno- [hTtetheeLTfaceSiTlenai the one is knqv™ b> tbunt to a greater quantity than that ot a water barometer, than the corref- by a jjke change, namely, about fourteen lines for every line fill of a water °* var»ation in the common barometer. That is to fay, if the barometer, barometer were to rife and fall again through half an inch, in tib 'than reatfy ^e murt t,me °* a ^e'c'ie* which I believe fcarcely if ever hap- ukes place. pens, the feiche itfelf could not rife above (even inches. The whole range of variation in the barometer could only caufe a rife of three feet and a half iniiead of five which fometimes happens. Another theory * would venture to conjecture that this phenomenon is one ctfered; that the among the numerous ofcillatory procelfes which take place •"toiretneron w',en two variable natural powers are oppofed to each other the rigidity of in the production or modification of any event. Moft fmall iity ?Ji dtfehar re" 'a^es are ^ormec* Dv l*ie enlargement of a river, by which the Jake is fupplied at one end and evacuated at the other. The quantity of water in the lake itfelf will, in thefe circumftances, be always more than would be fufficient to fill its capacity, taken from the level of the loweft point of difcharge. How much more it may be than this quantity will depend upon the ftreams which enter and pafs out. An increafe in the quantity of (apply will keep the level higher, and fo likewife will any increafe in the obftacles to its flowing off; and on the contrary, if the fupply be diminiftied, or if the facility of difemboging be encreafed, the level will be deprefled. Thefe eflfecls will take place moft ftrikingly at firft at that end of the lake where the efficient caufe operates. When any change has once taken place, fuch as that of the depreflion, it will continue for a thort time after the caufe has ceafed to act; fo that the depref- fion would itfelf be followed by a rife, even if the circum- ftances which caufecT it were not alfo fubjeel to a like variation. This effedr. is Changes of this kind, on a fmall fcale, are obfervable in mill- fctfl in brook-, dams, and even in the frnooth places in brooks or rivalets, as and anil-ponds. * may SEICHES IN THE LAKE OF GENfiVAi £05" may be obferved by taking notice of fome part of the bank where a gently riling fand may render the changes of level more conspicuous. The variablenefs of the weather at theltmuft be more i'pring and autumn, by occafioning more frequent changes in fp5ngCand'ail- the quantities of water, and confequently in the ftate of the tumn. rivers above and below the lakes in queftion muft render the feiches more frequent and extreme at thefe times. They will alfo be moil evident at the ends of a long lake; and the other circumftances will be modified by events that for the moft part wjould require to be afcertained by obfervations of the local circum fiances and events on the (pot. The diftinct poriions of rough and fmooth furface called The dlftin& fontaines, which are obferved on the lakes, are very ft rikingly j^ot" °Bd leen at fea whenever a breeze fprings up after a dead calm, rough furface on This effeel is very remarkable, and may perhaps be accounted ^Uti^ZVJux for on the fuppofition that the incipient motions of the air may a calm. be attended with eddies that may a 61 more ftrongly on one part of the furface than another. This however does not feem re- concileable with a certain fteadinefs of appearance with which the fmooth and rough furfaces continue diftincl from each other for certain lengths of time. I am not much fatisfied with the conjecture which offered itfelf to me, or which may have been mentioned by fome other perfon when I was at fea many years ago; but it at leaft deferves to be noticed here. It is well known, that the wind fcarcely takes hold of water which is covered with any oily film, and from the experiments of Frank- lin and others we have learned that a fingle drop of oil will Suppofed to arife rapidly fpread over a large furface of water, and caufe all the fron? 01'y .^"2 fmail primary waves to fubiide, rendering the furface extremely the water, fmooth. It feemed to me not unlikely that oily matter from animal remains might rife to the furface of the fea during a calm and fpread ilfeif irregularly over certain parts, which would continue fmooth for a confiderable time after the light commencing breeze had ruffled the other parts. I think from recollection that this appearance could not have lafted more than a quarter of an hour; but it is very common, and I often faw, it. May not a fimiiar caufe produce the appearance in —of the lake tfae lake of Geneva. alfo- The fonorous reports refembling difcharges of artillery feem The fonorous very likely to arife from the extrication of gas at the bottom reports refem- of the water, wrych rifes and breaks at the furface. I have fu'ppofed to be HO made by gafes. <20& MARKING COLOUR FOR LINEN*, &C. no remark to make on this fubjecl, but advert to it principally with a view to mention an eftecl not generally known, but/ calculated to fhew the agitation, which a (mall quantity of af- Remarkable ef- tending air can produce in water. If a i'wimmer (ill his lung?, feci of agitation with air by inhaling as much as poffible, and then dive down duclfby Sr°" or de*cend into the wattr t0 lhe deDth (>i fourteen, twenty or blown flowly more reet, and when at that depth flowly blow the air out of through the j^ mou^ }ie w[\\ himfelf hear a roaring noile, and the fpec- depth of feveral tators will fee with furprife the fur face of the water raifed mto feet beneath the a round or conical mafs about a yard in height, with the water- flowing round on all fides over a furface of (even: or eight fquare feet. I have little doubt but that the noile of this rifing co- lumn of water with the breaking of the bubbles of air would be very remarkable in one of the ftiil evenings or nights of fummer, when the efTec! of noifes is remarkably more im- prefiive. than when the louder founds of the day render them lek obfervable, and in many inftances altogether inaudible. xn. Experiments to aftertain the left Colour for marking the Heads of Pieces of Cotton or Linen in the rough, which jhalt be capable of re/ljUng the Operations of Bleaching, as ivell as the mqft complicated Procejfes of Calico Printingy without ^reading beyond the Limits of the Impreffion. By Mr. HauI*fmann«* Properties re- An order that a colour may be proper to maVk* j>iece good? quired in a good 0f every kind it is requifite that it (hould contain no fubftance or jnk. or drug capable of folution in alkalies ; it is equally neceffary that its component parts (hould not become white by oxygena- tion, and that they (hould remain infoluble in acids fufficiently ftrong for the bleaching procefies, as well as for the operations antecedent to the calico printing. Oil colours are Colours com po fed of drying oil cannot therefore, as I have' bad becaufc they found be ufefu! in thefe kind of marks, becaufe they are not yield to alkalies, . , J ■ &c. only attacked by alkaline and foapy liquids, but likewife be- caufe they dry (lowly, and by fpreading beyond the limits of impreffion, very often occaiion fpots. * Annates de Chimiej LIU. 208* * ' *■ ' *u' 5 If MARKING COIOUR FOR LINEN, &C. ^07 •If the colours of foirituous varnilhes were not fubjea 10 the- Varnifli colours v- - j j • i ? Tare equa||y faulty inconvenrence of too (peedy evaporation and drying they would in this rerpe&. be inadmiffibleon another account, namely, that the turpentine and refins are eafily converted into foap. Gum copal is equal- Copal yield* to ly unfit for marking colours, becaufe it quits the piece by boilinS water* fimple ebullition in water. But as the varnifli which I have made defends veflehr of copper or any other metal from the action of acids of a certain ftrength as well as from that of the atmofphere, I' have thought it might not be unacceptable to defer ibe its competition in this place. To obtain this varnifh Procefs for m^Ir- from copal as pale and as clear as water, this gum mud be re- j^* ^oplMn duced to very fine powder and expofed with twelve parts of powder is dif. the fineft oil of turpentine for feveral days, or until it (hall be {o]v/d }? ^at completely diflblved at a moderate heat on a land bath in a jn 0ii of turpen- capfule of brafs, (lone ware, or porcelain, taking care to ftir tine* it as- often as poflible with a rod of glafs. At the moment when the confidence of fyrup begins to take place, the entire folution of the copal is effected by agitation, particularly if a (mail quantity of oil of turpentine be added from time to time to fupply the lofs by evaporation. Three fourths of the oil of turpentine which is loft by evaporation when open veflels are ufed, may be faved by performing theprocefs in a long necked mattrafs, which is to be expofed on a fand bath a fufficient time to complete the folution of the copal, and fhaking it very often. The varnifh obtained by either of thefe methods be- comes yel.'owifh if the heat be urged too ftrongly; and as by its too glutinous confidence it would be difficult in its applica- tion, it is convenient, infiead of diluting it with oil of turpen- The copal var- tine, to mix it with one fourth or one fifth part of its weight of J1'?1,18 >° ,be ,dU r t> luted wan aico- alcohol, taking care not to ufe too much, becaufe an excefs hoi. would render it of a milky white by the precipitation of part of the copal, which cannot admit in its folution more than a certain quantity of alcohol without precipitating. VefTels of Metallic veffefe brafs or of any other metal may receive one, two, or three ^"bakS lu^' coatings of this varnifli, and mull be each time well dried in them may be the oven. After this treatment they may be wafhed with boil- exPofed t0 boi[- . J ing water with- ing water without injury, and may even be expofed to a ftill out injury, greater heat without the varnifli coming off; but thefe veffels muft not be rubbed with fand or other bud bodies. By means of oil of turpentine, which evaporates and dries Aa oily com- lefs fpeedily than alcohol, I fucceeded in making a black com- ^J^f^t' pofition other goods. 203 MARKING CdLOURS FOR tINEN, &C pofition, which I expected might be ufed with advantage tn marking piece goods. For this purpofe nothing more is need- ful than to diffolve flowly on the (and bath, and with conftant agitation. One fourth of its weight of afphaltum or bitumen, judaicum well pounded, and afterwards to mix as much lamp black, or any other dark coloured mineral in fine powder, . filch as black lead, galena, or the like. This colour may be had more or lefs thick, by due proportions of the oil of turpentine and bitumen; it prints very well without running, if the proper proportions be attended to, and a little oil of turpentine be added when it becomes too thick. This bituminous colour fupports- the action of alkalies and of oxigen very well, and refills all acids of moderate ftrength. As I thought it unnecefTary to continue my experiments on oil colours, I made my experiments on watery compounds in the following order. Sedion I. Flrft marking I dilToIved in four ounces of water one ounce of the fulphate procefs. An im- 0f Manganefe without its water of cryftallization ; that is to preffion is made /....„.—_,, of a folution of lay> it was in the ltate it poflefies when oxigen gas is pro- fulphate of man- cured from the black oxide of manganefe, by means of the with gum^ and6 lulphuric acid, and by raifing the heat to ignition at the end covered with of the procefs. This folution was thickened with one dram doth beinAhen °^ mie &um adragan m powder, and coloured with lamp dipped in alkali, black, in order to diftinguim exactly the impreffion which the manganefe be eaf. made wilh ^ bjatk fa|ine metaljjc mafs> 0f precipitates in V, f t ■■ . ■> --'. brown oxide which neverthelels, we cannot make effective ule without which affords a plunging the end of the marked piece into an alkaline ley, Sfcharged by taking care that it (hall not firft be wetted with water, which bleaching, or by would carry off the faline matter. The ley may be made «ocfffoa.Un* wil{l Potam or foda> in tne proportion of one part alkali to nine or twelve parts water. It may be ufed in the itate of carbonate, or rendered cauftic with half a part of quick lime. The precipitation of the oxide of manganefe from the marks by either of thefe alkaline folutions will take place (exclufive of the ftain from the lamp black) of a yellowilh white colour, which will become more and more brown by attracting the oxigen of the atmofphere. The change of thefe marks to the brown, and even to a deeper colour inclining to black, will MARKING COLOUR FOR LINEN, &CV %& will take place very fpeediiy by bleaching with the oxigenated alkaline muriatic ley, the pieces of which the ends have been plunged for a few minutes in the alkaline as before pre- fer i bed. Thefe marks of the brown oxide of manganefe refill not only all the bleaching materials, and all acids of a requisite force, but likewife the moft complicated procefs of manufacture of calico printing. Se&ion II. If the acetic acid had not a much ftronger affinity with The acetate ot\ manganefe than it has with iron, and if it difengaged it- "o^teufed with* ielf as readily from the acetate of manganefe as it does out the fame from the acetic folution of iron by evaporation and drying, ^aHtTsmore we mould be able to procure indeliable marks in the molt coftly itmuft be fimple manner, by depofiting the oxide of manganefe on reJefted» piece goods by means of the acetic acid, and afterwards iimply leaving the oxide to the attraction and faturation of oxigen from the air. The acetic folution of manganefe is very readily obtained by mixing a proper quantity of acetate of lead in a folution of fulphate of manganefe. But as .this acetic folution affords no advantage in marking piece goods beyond thofe of the fulphate of manganefe, and as it requires precifely the fame management as that defcribed in the Iaft fection, and it is likewife more expenfive, it deferves to be rejected. Scaion III. Two ounces of fulphate of magnefia diflblved in eight Sulphate of ounces of the acetic folution of iron, concentrated to the point ma"^ane[e. wIth ' acetate or iron indicated by twenty degrees, afford when thickened with treated as before, one fortieth part of gum adraquack, a deep yellow liquor Itdr^smore which becomes more and more brown, when treated ab- folutely in the fame manner as defcribed in the firft paragraph. The acetic folution does not, however, afford any other advantage but that of caufing the marks to dry a little more fpeediiy ; for the oxide of iron diflblves in acids accordingly, as it is oxigenated. I give the preference to gun>adragant for thickening colours, to other gums and to ftarch, becaufe thefe fubftances weaken the colours too much , if however, there mould be any objection to gum-adragan in Coarfe goods, Itarch may be then ufed. '■' ' f v ■' Vol. XII.— November, JS05, P Scftion IV. $IQt MARKING COLOUR yo* LINEN, &C* Section IV. Marks printed If care be taken in the procefs of difengaging oxigen gas Txide^f man- ^om a mixlure oi" llle H^k oxide of manganefe and fulphuric gancfe obtained a^io^ r^pt to carry the lire to ignition, the ("aline retidue re- wfi^S'fuVhate, ™^-S ^laVkin)' inftead of becoming yellowim white by thong afford fixed "eat. When this refidue is diffolved in water, it leaves marks i b) fimple behind it an oxide of" a deep grey, which acquires a very party continence on the filtre. This oxide mixed with a very little water thickened with gum adragant, may be ufed to print marks of a very deep grey, which dries fpeedily j and this colour does not wafh out with water, even though the fub- fequent dipping in an alkali be omitted. It is fo fixed that it not only fupports the action of all acids of the manufactur- ing ftrengths, but likewife all the bleaching and printing procefles without attracting the colouring matter of any dye whatever. Setiion V. Addition of the If there were no reafon to fear injuring in a {light degree nitro muriate of ^ jace wj)ere l}]e mafa js m^e \i VVOuId be advantageous tin to the mark- ■".-'./' « ing oxide. It to employ equal parts or the Iaft defcribed grey pafte, and affords a dye. 0f a ni[T0 muriatic folution of tin, containing one fourth part of the metal, and thickened with gum-adragalh. Tliis colour is as unalterable as that of the fourth feclion ; and it has the additional advantage, that its oxide of tin being fa- turated with oxide of oxigen, attracts the colouring parts of any tinclurc, and acquires a puce colour by madder. I muff, oblerve on this occafion, that by the fame madder dye, the colours of marks from the oxide of manganefe laturated with oxigen, become of a deep puce colour, inclining to black, whereas in a lefs oxigenated ftate they acquire fainter (hades. In all thefe circumflances however, it is requifite, that the quantity of metallic oxide mould be as great as polTible, other- wife the (hades will be various, and leis interne. Sea ion VI. Experiment ^s mally »nC°^D^ metallic oxides acquire the property of with the pre- adhering to -fluffs by means of acid, I did not fail to try whether cipiute or man- ^ p e vvon{j jje t|ie cafe wjtjj tj]e precipitate of manganefe tionoriron. faturated with oxigen. For this pvirpofe I ditfblved oue pari MARKING COLOUR FOR LINEN, &C. $11 of fulphate of manganefe in fix parts of water, and precipi- Experiments tated the metal by adding to the point of faturation a cauftic **lxztt ofmln- alkaline ley, made with half a part of quick lime, four parts ganefe and of water, and one part of calcined potalh of the (hops. The Nation of iron. precipitate was yellowilh white. To the whole aqueous mafs I then added a iufficient quantity of oxigenated muriatic alka- line lev, until the precipitate was completely faturated with oxigen, and its brown colour became no deeper. I afterwards collected on a filtre the precipitate or brown oxide of manga- nefe, where, by the drainage of its water, it became pafty. This brown pafte, mixed with half its weight of the molt con- centrated acetic acid no longer afforded any but a weak brown- ifh made; it was the (ame with a fmall addition of one or the other of the three ancient mineral acids in a ftate of folution. I did not fucceed better by mixing one part of the fame brown pafte with an equal quantity of the acetic folution of iron, marking 20° of the areometer of the faltpetre makers and thickened with gum adraganth. This acetic folution of iron containing only the quantity of oxigen neceiTary for the folu- tion of the metal ceafed by a fironger affinity, the excefs of oxigen of the brown oxide of manganefe, which in its turn became diflblved, and the mixture of the two metallic folution* afforded a yellow reddifh very deep and tranfparent liquid, which confirms the fact that a metal faturated with oxigen re- quires lefs acid for its folution than if it were in an oppofite ftate, and that being then furnilhed with an excefs of acid, the folution faturated with oxigen can admit a portion of another metal without becoming turbid. This mixed folution of the two metals afforded me only a rufty yellow* which was dis- charged by weak fulphuric acid completely, in fomewhat lefs time than was required to take out a ruft fpot in a lefs oxigen- ated ftate. In order to obtain from the mixture of thefe two metallic iolutions an indelible marking colour, it is necedarv that the marks mould be fteeped for feveral minutes in an oxi- t genated muriatic alkaline ley, to precipitate and faturate the oxigen of the oxide of manganefe. By mixing half a part of the brown pafte of manganefe to two parts of the folution -of the two metals the new portion remains untouched and renders the whole turbid. This turbid mixture left only a light brown- i(h mark on piece goods, which. hud remained long in the di- luted fulphuric acid* V2 B* L'l^! V OF 'OASES, &C The muriatic By means of the muriatic folulion of tin, which' has- the folntion of tin . . , , . . * , . . . tvk.es up the ox- ProPerty °' taking the oxigen from many vegetable, animal, ides ot'iron and and mineral fubftances, and which,"on this account," is- very o, ma gau.i.. ufefui Jn dying, as welt as in calico-printing. Wemaydif- colour and diflblve inftantly the deepen* oxide of manganefe and. of iron, which proves the preponderating affinity of '"iih towards oxigen beyond that of manganefe of of iron. N. B. There is no reafon to object to fteeping the marked goods in an alkaline ley ; the operation is fpeedily made with- out feniible lofs of potath or of foda, if the operation of lix- iviating be immediately proceeded upon, for which the re- mainder of the ley may be ufed. And generally, if the practice be ufed which has been adopted for a number of years, of rendering the alcalies cauftic with quick-lime, the faving will be confiderable and with better effect. , , , , , ,. — _^-- Alll. Aoff on the Formation of Water by mere. CompreJJlon; ivith Reflections on the Nature of the fileclric Spark. Bj/ M. • 'Brer * ■■'•SM***^4'^ '^ That oxigen IT was fome time ago that, in converfation with M. Ber- ma* unite?™ thollet on the nature and properties of heat, I communicated preflur*. to him the perfuafion I had, that the combination of hidrOgen and oxigen gafes might be determined without the aid of electricity, and merely by a very rapid compreffion. This remit appeared to me- a confequencc fo immediately follow- ing the obfervations already made on the heat difengaged from air by compretfton, that I thought it needlefs to afcertain it in any other manner. But having iince converfed with Mr. La Place, he appeared fo intereiled asftrongly to urge me to ^ a verification. I therefore made the experiment, which com- pletely fucceeded. "It wras made in the cabinet of the Poly- technic School. I am greatlv indebted to M. Haffenfratz, (uofeflbr of natural philofophy in that eftablimment, for the Read to the National Indicate of France, and inferred in the Annales de Ghimie. LIU. 321. •great COMBINATION "OF GASES, &C. 0\3 great attention he paid in caufing the requifite preparations to be made, and for hisperfonal affiftance in repeating it. We took the fyringe of an air-gun, the bottom of which Experiment In was clofed by a very thick' glafs, in order that we might ob- j^ngeof an air-" ferve the light difengaged as ufual by compreffion. This fy-*gun filled up fo ringe was of iron : it had a cock on one fide to introduce the as ,t0 reCj,Vj th„e ? m * gales and admit gates, and its lower extremity on the fide of the pifton was or infpeaion enveloped by a cylinder of lead, fufficiently weighty to acce- mto its chamber, lerate the fall and render the compreffion more rapid. This with common apparatus was firit tried by introducing atmofpheric air ; but air> though the experiment was made in the dark, no perceptible light was feen, probably becaufe the violent motion neceflary for the rapid compreffion, prevented the operator from look- ing fo directly through the glafs as to perceive the tranfient light which compreffion difengages, and which I myfelf had feveral times feen. -non-Mfm Immediately after this trial a mixture of hidrogen and oxigen and afterwards r i i - . „t ■'..«, v,a .- ,,• i n i • with a mixture -gales was introduced into the fyringe, and a itroke was given. o{ ox;gen and An extremely brilliant light appeared with a loud detonation : hidrogen. The glafs bottom was driven out: The copper fcreW which ?,jfceab ^ retained it in its place was broken ; and the perfon who held ftrong luminous the fyringe had his hand (lightly burned and wounded by the explofion. force of the explofion;" The experiment was repeated, by fubilituting a brafs bot- Repetition with torn of one entire piece fere wed on inftead of that of glafs. ThTfvringe^* and a new mixture of the gafes was introduced. The firft burft. tiroke of the pitlon produced an explofion, which was heard like the loud crack of a whip ; but a fecond itroke with a new charge of the gafes, cauled a detonation which broke or rather tore the body of the fyringe with a violent explofion. After thefe phenomena there can remain no doubt respect- ing the combination of the two gates;' as it is known that this combination produces the detonation by the immenfe quantity of heat difengaged when they pals to the liquid liate; a heat which is fufficient to reduce them immediately into vapour, and give them an exceffive dilatation in that ftate. It was not therefore thought neceflary again to repeat ^^^ this experiment, which is attended with fome danger. ^JH^The theory of thefe phenomena is extremely rimple. A Theory, the rapid compreffion forces the gafes ta abandon- a ^erygre«t|nfes kive out it»Hiw»T 5 quantity 214 COMBINATION OF GASES, &C. quantity of heat, which not being capable of immediate cHflfi- pation, raifes their temperature in the inftant fufliciently to inflame them in this Rate of com predion. Thus it is that we find in the two gafes all the elements neceflary for their combination, independently of the electric fpark or external heat. We might probably in the fame man- ner, and without any foreign agent, produce all the gafeous combinations which require an increafe of temperature. Deduction. This identity of refults has led me to a notion which I fpark may con- fubmit to the judgment of philosophers. It is known, and M. fift merely of BerthoIIet has fliewn it in his Chemical Statics, that electricity from coroprcfTcd '" Pau^ng through bodies, produces a true compreflion of their air. particles. This effect is produced with the moft extreme velocity, as may be proved by an affinity of experiments. Now eleclricity pofleifing a velocity fo great, it is impollible that it lhould not difengage light from the air, fince we Can difengage it by a compreilion fo much lefs rapid. In this way it is that we are led to a conclufion, that this refult of the electric fpark is the purely mechanical effect of compreilion. More ample ex- If we now compare what pafles in our condenfing pump Sanation. The an(J jfl tJie eudiometer of Volta, we fhall find that the analogy extreme velocity OJ of ele-ftric mat- is complete. Only that in the fir ft cafe we are obliged to ter will ftrongly confine the air, becaufe the velocity we can give to the pif- eomprefs tree ..... „TI . , *: . ._ . . . . . ai^ ton is limited. Whereas in employing electricity, the particles are comprelfed by a velocity (o great that they can never withdraw themfelves with fufficient fpeed from its effort. Therefore the compreffion may be equally well made in the open air, together with the difengagement of light or the fpark, which is its confequence. But this effect is local ; and if the gafes be not fufceptible of combining together, (liould after each explofion return to their primitive dimenfions, they muft immediately refume in this dilation all the heat they had before dilengaged, fo that there cannot be effected any lafling change in their conltitution. This explains why no alteration has ever been feen in very pure unmixed gafes, when fubjected to the action of the electric fpark. **id alfo the rare This light which eleclricity difengages from the gafes by urvi" compreffion, it mud alfo difengage from the more rarified gafes, and on account of its extreme velocity, it muft difengage it even from vapours, when experiments are made under the receiver ACCOUNT OF. THERMOMETERS. 2l5 . receiver of an air-pump or in the torricelian vacuum : For, w;e can never form a perfect vacuum with our machines, and even in the tube of the barometer mercury always exifts. in the form of vapours. Thefe vapours, though very rare, ilill con- lain a large quantity of caloric, which the electricity muft dis- engage in its paflage by com predion ; but the inllantaneous augmentation of electricity which remits, cannot become fen- iible on account of the little denfity of the medium ; but this increafe is perceivable in denfer air, as we lee in the inftru- ipent called Kinnerlley's thermometer. N The coniiderations which I have here made, appear to me Conclufion. to point out with fome probability, that the phenomenon called the eleclric fpark, is owing to the light difengaged from the air by compreffion during the paflage of the electricity ; fo that this phenpmenon is purely mechanical, and not at all eleclric in itfelf. This is the notion which I fubmit to the judgment of philosophers: if it be true, it muft lend consi- derably to diminifti the number of hypothefes which have al- ready been made, or may be made on the nature of electri- city. For this reafon it is that I have offered it to their con- sideration, requeuing that it may not be be thought that I contider it as of greater importance than their deliberate exar mmation may beftow upon it. XIV. Account of Thermometers for regijtcring (he highejl and lowefi Temperatures in the Abfence of the Obfrver. % F, A. - To Mr. NICHOLSQN. * the i- *>i i r i • . i • i • /■ it- fluid would hang direction by a force equal to that which is to employed in to it and draw it maintaining that concave figure; and if it were at liberty to baclc» move, it would be drawn back till the flat furface Was re- ftored. Let us fuppofe a fmall flick or piece of glafs to be Joofe within the tube, and to protrude into the vacant fpace beyond the furface of the alcohol. The fluid will be attracted alfo by this glafs, and form a concave between its furface and that of the bore of the tube. But the fmall interior piece being quite at liberty to move, will be drawn towards the fpirit fo long as the attractive force poffeffes any activity ; that is, fo long as any additional fluid hangs round the glafs ; or in other words, until the end of the flick of glafs is even with the furface. Whence it is feen that the fmall piece of glafs will be refitted, in any action that may tend to protrude it beyond the furface of the fluid ; and if this refinance begreater than the force required to Aide it along in the tube (as in fact it is), the piece mult be Aided along as the alcohol contracts ; fo as always to keep the piece within the fluid. And this fact is accordingly obferved to take place. Abftraft 3l& *N MILK AND BUTT1R. XV. Abftracl of a Memoir on Milk. By M* Then ard.* T » f mTntpart * rnenioir wh5cn * rca(* to tne Philoroalic Society in Praircal laft, I mewed that milk always contains the iieti acetous acid in a greater or lefs quantity. At the fame period Meflfrs. Fourcroy and Vauquelin found that it alio contains phofphate of magnefia, and that the lactic acid of Scheele, or that which is obtained from ferum of milk fpontaneoufly coa- gulated, is merely the acid of vinegar combined with an ani~ mal matter., So that in t{ie prefent (late of our knowledge we muft confider milk as coropofed of, 1. Water y 2. Acetous acid; 3. Cafeous matter; 4. Butteraceoijs matter; 5. Sugar of Milk; 6. Extractive matter; 7. Muriate of fad a and of potalh; 8. Sulphate of potath ; 9, Phofphate of lime; 1Q. Phofphate of magnefia. Of thefe eleven fubftances there is one whjch I particularly examined feme months ago, namely cream. I was defiroivs of ascertaining the circumftances which govern its feparation, and particularly its transformation into butter. The reparation J had before obferved that milk coagulates as readily in butter does'not p'°W as m °Pen ve^^s J I know that no gas is difengaged in require actefs of this decompotition, and that, in order to effect it with ra- **• pidity, it is needful only to raife the temperature to between 20° and 40° (Reaumur I fuppofe; and, if fo, anfwering to 77° and 122p Fahrenheit). It was clear, therefore, that the air contributes neither to the formation nor the feparation of cream, but that it exifts ready formed in milk; but it remained to be fliewn what are the principles which enter into its comr pofition. Being perfuaded, from various obfervations I had made, that it is only an intimate mixture of butter, cheefe, and ferum, I proceeded to ascertain this point by mixing a pint bottle (Englith quart) of recent cream nearly to its neck, from which I difplaced the remaining air by carbonic acid. I then clofed it well, and agitated it ilrongly in eyery direction for half an hour; at the end of which time the contents having loaoia ♦ Soc. Philomath, No. 06, become OVMIIK AND BUTTER. gj$ become very thick and adhering ftrongly to the fides ©f the bottle, gradually became detached, and foon afterwards were converted into a while liquid, in the midft of which fwam a yellow mafs of excellent butter. Hence it follows, that the butter exifts in the milk, and is feparated when the milk, • g being deprived of the vital action, is left to ilfelf. At this lime, either by the formation of an acid arifing doubtlefs from a decompotition of the extractive matter, or perhaps from the lefs fpecific gravity of the- butter compared with that of the cheefe; for the butter begins to Separate almofl at the moment that milk is poured into a veflel ;— -the milk is decompofed, the cream rifes to the top, and from thislaft, by agitation, and more particularly by the affiftance of a temperature between 15° and 20° (66° to 77° F.), butter is obtained together with Proeefs of totf. butter-milk, which is a white very mild liquor, in which fometerni ^ ' butter and cheefe are fufpended in a very divided flate. But the butter thus obtained is not pure : It ftill contains a portion of cheefe amounting fometimes to the iixth part of its weight; . and this is the caufe of its fpeedily becoming rancid, parti* cularly in Cummer. When the cheefy matter is feparated by fqfion, the butter may be kept a long time. It is true indeed, that by this fulion it acquires an acridnefs which greatly limits its ufes, and makes it unfit to be employed in frying; but this } ^ difadvantage might be remedied by keeping the temperature *"<* much lower than is ufual. Clouet firft made this observation; and hence the following procefs may be adopted for purifying butter, or feparating the cheefy matter without giving it a bad tafte. 1 . Let the butter be melted on the water bath, or at a degree 'Purification of Of heat not exceeding the 66° of Reaumur. 2. Keep it melted bu,tt(7b,y fufiort* till all the cheefy matter is collected in white flakes at the bot- the chce/y part. torn of the veflel, and the melted butter is tranfparent. 3. At this period decant it, or pafs it through a cloth. 4. Let it be cooled in a mixture of equal parts of pounded ice and fea-falt; or if ice cannot be procured, then in cold fpring-water, making ufe of broad mallow veflels. Without this precaution the butter would become lumpy by cryftallizing, in which Irate it could not be ferved at table. Beftdes which, the parts being con- denfed by this fudden cold, are found to reiift the action of the air more effectually. With this laft intention it is aifo proper to 1MB tj|S^£4HNTIF,JC »NEWS»ro tp cover the pot in. ytWich the butter is kept very exa&Jv, and to piacc il in a cold expofure, fucli as a cellar. By this treat- ment batter may be kept foj> fix months or more, and will be nearly as good as frefli butter,. particularly alter the top is taken off. it is even poiiible to give this fujjed butler to a certain point the appearance or frefh butter, by beating it with one iixth part or its weight of the cheefy matter ; and fo likewife rancid butter may be confiderably amended by the procefs of iuiion and cooling here prefcribed. .:^.t 1 km SCIENTIFIC NEWS. Temperature of the Sea. General farts 'i-V-lR. PIRON has lately communicated to the French Na- rcipefting the tional Inflitute a memoir on the temperature of the fea : an in- temperature of ■' m-ll) T1EV l >s J > • the fea. terelting lubject, capable ot bctng applied to -various menu purpofes, and which has accordingly engaged the attention of a coniiderable number of philofophical obfervers. His ge- neral facls are, I. The mean temperature of the fea at its fur- face is commonly more elevated than that of the air. 2* It \s higher the nearer to the continents and large iliands. 3. At a diltance from the (bore in deep feas the water is colder below than at its ftirfaee ; and the more the greater the depth. All ithe obfervations feem to (hew, that in the abyifesof the ocean, as well as on the fummits of mountains, even under the equa- te great depths tor> eternal froft prevails. 4. A fimilar cold is obferved in : c ernaliy exten.five lakes, and. even within the earth at great depths, but it appears to be lefsfudden. 5. Theie refults concur in proving, that the temperature within the earth is not every where the fame and equal to 931°, as has been long thought (about 50* Fajir, whether this be centigrade or Reaumur's fcale.) **^-. Spent Oil of the Curriers. Concerning the The procefs by which the carriers impregnate their fkins is pounds u°fed"in -•>* by ^mear'ng lne oil upon the wet iltin, into which it pene- currying leather, trates as the moifture evaporates. A pure oil could not perhaps ■ :'v be 1 . rr- SCIENTIFIC NEWS* be -thus fpread, and mod probably would not enter the fkm with thedetired effect; or render it as iupp-le as that oil which from experience : they are led lo prefer. The celebrated Seguin has directed his attention to this in- gredient of fuch extend ve manufacloring utility. He remarks, »V»nA that this material (by the name of Degras) is of two kinds in France; viz. the common fort and that of Niort. The RtfcQi* .casfei'lct the- immediate prod u 61 of the chamoying of (kins, which are cleared oi' their furplus oil by folution of potalli. It therefore contains not only foap, but likewife gelatine. It is evaporated' to dtynefs and then Md&Degras. At Niort it is decompofed by l'ulphuric acid, and the precipitate is called the Degras of that town. AVl* Mr. Seguin finds by analyfis, that this laft is oxigenaled oif, whereas the other is a compound of foap and gelatine. He fucceeded in giving to whale oil all the 'properties of the Degras of Niort, by boiling one pound for a few minutes with half an ounce of nitric acid at 2.5 degrees. He obferved that no gas is difengaged in this operation; but that water and ni- trate of ammonia are formed ; and he concludes that the oil was oxigenaled, nol by abiorbing the oxigen of the acid, but by yielding to it partof the hidrogen which was one of its own com- ponent parts. The refult is the more intcrefting, astheZtegrasof Niort being much more eftcemed th art the common fort,' the -t'uV' Ja^<;M curriers may hereafter, inficad of paying a great price for it, *-**r make it in as large quantities as they pleafe by following the procefs here indicated. .noil ahaooA ■ Jfqte re/peeling the Decompofdion of Sulphate of Lead % thz Muriatic Acid. By M. Descotixs *. :K,\ If the fulphate of lead be treated with muriatic acid rather Sulphate of lead concentrated, that metallic fait is totally diffolved) provided''!8 fo,ub!e!>yhfat the proportionof acid be rather in excels. This' folution re- Muriate of lead* quires heat to effect it. Upon cooling, the muriate of lead'feParates by cryftallizes in great quantity; and it is much more fpeedTly \^l\u Jje ^ obtained by the addition of a fmall quantity of cold water, water, and may If tb« Supernatant fluid be fenarated from the crvftallizea faf^Yf [n *■»"» ' * I **■># t»r ' ..^ofedbyfulph, * Soc. Fhilom,No. 9G, sail A '10 ID .IJc I K'rs\ Jim j I — it l [ja&d -(mi All twi !> u» fficJt.'IsoiiW Thilc*\ Journal. VoLXIEFl. VHT.p. S Z J. Huholumklfrilo*. Journal. VoI.XU.FIJX.jk 224- Fiq, Z. 3£ud*» SrJ!u,Jv71 , tfuhohrons- IfyUof. Jowrull.Tol.JnLPl.X p. 224 2 /'V '/t-f/'.l A'////;/ * /jufc ebffU77m&t/ymi Fig.l. 'f?\}*o\xe\vx> 00 Soy 0,60 40,40,30 xo\io\ 0 ,2o,g0.3l> T JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY AND THE ARTS. DECEMBER, 1805. ARTICLE I. On the Divijion of an Arch of a Circle into two fuch Parts, that their Sines, or Cofines, or Verfed-Sines, Jhall Iiave a given Re- lation. In a Letter from John Gough, Efq. To Mr. NICHOLSON. SIR, JDEING at prefent on a vifit to my friend Michael Fryer, Introductory teacher of the mathematics at this place, I have availed myfelf letter' of the opportunity to confult his very extenlive mathema- tical library, with a view to difcover how far the following theorems and problems are original ; thinking it poffible, at leaft, that fimilar propositions might be met with in the works of the early geometricians, particularly in the traces on An- gular Sections, by Viela, Oughtred, Wallis, and others, which I had never before been able to meet .with ; but I have found only one of them to have been already treated, of which no- tice (hall be taken in its proper place : neverthelefs, it is not improbable but that fimilar theorems and problems are fcatteted up and down in the different works on geometry at prefent in ^xiftence : As this eflay, however, may claim the merit of Voe. XII.— December, 1805. Q c*» 225 DIVISION OF A CIRCLE. exhibiting them in one view, and, which is equally defirabTe* of deriving them from a general principle, I have ventured to offer it for infertion in your Journal. JOHN GOUGH. Reeth, near Richmond, York/Jure, Augujl 28. Proposition I. Theorem. Divlfion of an Let A F be the arch of a circle, (See Fig. 1 , PI. XII.) A P fmo^oVam1* a ta°gent at A; FP a perpendicular toAP, then A P is having tfaeir equal to the fine of A F ; F P, the part of the perpendicular ^s,°^^^ intercepted by the tangent and the point F in the arch, is given ratio. equal to its verfed fine ; and the fame line, P M, intercepted again by the circle in M, is equal to the verfed fine of its fup- plement. Demonftration. Draw the diameter AK, and the fine FS perpendicular thereto ; alfo from the center O, draw O L at right angles to PMj then, fince PA touches the circle in A, PAK is a right angle, (Euc. 16. iij.) Aifo, the angles F PA, ASF, are right, by conduction ; therefore A S F P is a parallelo- gram, the oppofite fides of which are equal, namely, AP = the fine S F, and P F = the verfed fine A S, (Euc. 34-. i.) Again, fince O L is perpendicular to P M, it is parallel to A P and S F, therefore P L = A O, or OK; and F L = SO, (Euc. 34. I.)— But FL = LM, (Euc. 3. III.) Con- fequently P M =: S K, or the verfed fine of the fupplement AF. Q. E. D. Proposition II. Theorem. If A F B be an arch of a circle, (See Fig. 2.) and A P, B R, be tangents at A and B, from any point, F, in the circum- ference, draw FP, F R, perpendicular to the two tangents, and F Q alfo perpendicular to the chord A B, then will the reftangle PF X FR = F~Ql*; and the rectangles AP x B R, and A Q x Q B, will alfo be equal. g Demonstration, Join A F, F B, and the triangles P F A, Q F B, are equi- angular, becaufe they are right-angled at P and Q, by con- ftruaion ; and the angles P A F, Q B F, are equal, (Euc* 32, III.) therefore, DIVISION Or A CIRCLE* . 22? Therefore, as AF : FB: : PF : FQ. Divifion of an Alfo, the triangles QFA, RFB, are equiangular, for the ™££*™£ fame reafons. having their Therefore, as A F : F B : : F Q : F R. fincs> °r cofines, Confequently, as P F : F Q : : F Q : F R, (Euc. 11. V.) g0[vevn ™* w * And P.F x F R = F Q>, (Euc. 14. VI.) Q. E. 1° D. Again, by the fame triangles, as F A : F B : : A P : B Q, and asFA:FB::AQ:BR; hence, as A P : B Q : : A Q : B R, Whence A P x BR = B Q x A Q; Q. E. 2° D. Corol. I. Produce the perpendicular FQ till it meets the circumference again in G, and PA x RB = FQ x QG: For PA x RB = AQ x QB by the propofition; but AQ x QB = FQ x QG, (Euc. 35. III.) Corol. 2, If the lines P F, R F, meet the circle again in M and N, then will PMxRN =*Q"gV : For~AP}a = F P x P M, and~BR)2 = F R x R N, (by Euc. 36. III.) Therefore, as~AP)2 :FP*PM::FRxRN :""br\4 : But~XP\2 :FQxQG::FQxQG C$VK by Corol. 1 . And P F : F Q : : F Q : F R, by the propofition. Therefore, P F x P M : F Q x P M : : F Q x R N : F R x R N. Hence, FQxQG:FQxPM::FQxRN:FQxQG. Confequently, PM x R& = QG>. CoroL 3. Draw the diameters A K, B D, and make F S, FT perpendicular to A K, B D ; then A K x B T (the red- angle of the verfed fines) = Fq)2 ; S F x FT (the red- angle of the fines) = A Q x QB; andSKxTD (the re&angle of the fupplementary verfed lines) = QG)a. Thefe things follow from Props. I. and II. Proposition III. Problem. « To divide a given arch of a circle (A B) into two parts (A F, f B), fo that the redangle of their verfed fines (A S, B T} may be equal to a given magnitude, or fquare, (m x mj. Q 2 Conjlruaion. 0(2S 0IVISION OF A CIRCLE. Conftruftion, Dlvifionofan From any point, Y, in the right line A B, draw Y Wat arch of a circle r|ght angles to the fame, making it equal to the given right having their ' '»ie ** i through W, parallel to Y B, draw WF, and let it cut fines, or cofmes, the arcn a B in F, then will A F, F B, be the required arches, or v. fines, in a 8iven rati0' Demonjlration. Draw F Q perpendicular to YB, then F Q* = W Y* = m x m ; by Conft. and Euc. 34. I. ; but the rectangle of the verfed fines of A F and FB = F*qK (by Cor. 3. Prop. II.) ; therefore this re&angle is equal to m x m, the given fquare. Q. E. D. Proposition IV. Problem. To divide A F B, a given arch of a circle, (See Fig. 3.) into two parts, A F, F B, fo that the rectangle of their fines may be equal to a given fquare, (n x n) ? Conftruclian. To make the conftru&ion general, let AFB be greater than a femicircle, join A B, and in it take Q, making A Q X Q B = n x n ; alfo in A B produced take q, fo as to make AqxqR=nxn; draw Q F, qfg, perpendicular to A B ; then will A F, F B, or Ag, g B, or A/, /B, be the required arches. De7iion ft ration. This is evident from Cor. 3. Prop. II. and the conftrucVion. To find the limits, bifecl A B in Z, draw alfo the radius O N parallel to Z B, and make N E perpendicular to A B produced ; then, if ;n x n be greater than A Z x Z B, F is an imaginary point, becaufe A Q x Q B cannot exceed A Z X Z B, by Euc. 5. II. Again, if n x n be greater than A E X E B, the points/, gt are imaginary, becaufe Aq X q B cannot exceed A E X E B, feeing E N touches the circle in N, and is parallel to qg: Thefe things being premifed, it will be eafily perceived, that when A F B is lei's than a femi- circle, it can only be divided in one point to anfwer the con- ditions of the queftion, becaufe the point N will be in the op- pofite fegment; but when it exceeds a femicircle, it will ad- mit of being divided into one, two, or three points, according to circumftances, or even the conftru&ion may prove impof- fible. Q, E. D. Schojjum DIVISION OF A CIRCLE, 229 Scholium, This problem is conflrucled at page 342 of the Appendix to Division of an Simpfon's Algebra, 2d Edition; and at page 140 of his Seleft j^0 t^ V^,* Exercifes, 1ft Edition; but the conftrudions given by that having their able geometrician do not mew the various limits of the quef- ^"'^es^a tion with that degree of perfpicuity which appears in the pre- given ratio, lent method. Lemma. Let A B C D be a fquare, (See Fig. 4.) from any two ad- jacent fides of which, C B, CD, take the fegments T C, C S, then will the rectangle of the remaining fegments BT X S D = BCTl* + TCxCS-BCxCT-BCxCS. Demonjlration, Draw S G, T H, parallel to B C, C D, and let them inter,, fea in F ;— Then the Wangle FTCS=TCxCS, and the reftangle FHAG = BTx S D, Butf H A G -f G B C S -f H F S D = the fquare -ABCD; (Euc. l. II.) Add FTC S to both, ThenFHAG + GBCS-f TCDH = ABCD + FTCS; But. C D is equal to B C, Therefore F H A G =ABCD + FTCS-BC x CT- BC x CS; That is, B T x S D = Bey +TC x CS-BCxCT- B C x C S. Q. E. D. Proposition V. Problem. To divide A F B, a given arch of a circle, (See Fig. 5.) into two parts, A F, and F B ; fo that the reftangle of their cofines may be equal to a given fquare, k x k ? Conjiruclion, Join A B, and from the center, O, draw O Z perpendi- cular to A B ; in ZO take Z V equal to the given line, k, and join B V ; draw the diameter, H h, parallel to A B, and divide it in I fo as to make HI x lh = B V)2 ; from I draw I Q perpendicular to A B, and when produced let it meet the given arch in F -, then will A F, F B, be the required arches. PemonJlration9 £30 DIVISION OF A CIRCLE. Demonfiration. DivMon*fan Let FI meet the circle again in G, draw the diameters arch of a circle A j^ B j^ and the fines F S, F T ; having their ' Then the cofine O S = O A — A S, fines, orcofincs, and the cofine O T = O B -" B T = O A - B T ; gfvenratio! Hence SO X OT = AO^-f- AS xBT-AOxAS- AOx BT; But A S x B T = Fq)*, by Prop. II. Therefore, : SO x OT=Xo)24-Tq\»~ AOxAS-AOxBT. Again, KS = 2AO~AS, and DT = 2AO-BT; Hence, K S x DT = 4 AOY +ASxBT-2AOx AS-2AOxBT; But K S x D T = q"g)% by Cor. 3. Prop. II. Therefore, 4TA15V+TQV- 2AOxAS-2AOxBT=QG>;, , FQl2 Q"G> Hence, AO x A S -f AOxBT = 2XoV + --~ - -^— t ButS0xOT = AO2+FQ*-AOxAS-AOxBT FQ = FI-IQ = BP-OZ, andGQ = GI-HQ:=BV-f-OZ; FQa GO* s s Hence t-±- + H^L = BVY + 02)s; 2 2 } • Confequently, S O x O T ~!Tv]* + O^)2 - A3] * ; But a51* -~ol£8 = b oy -"o2|* ="bB* 5 Therefore S O x OT:=fBV\2 - "BZ] * zzVl!\ *, (Euc. 47. I.) r= k x k, by conftruction. Q. E. D. Limitation. — If Z V be greater than Z O, B V will be greater than BO; i. e, F Q will be greater than H h, which is impoffible, Euc. 15. III. therefore Z V, ork, cannot ex- ceed Z O. Proposition VI. Problem. To divide A F B, a given arch of a circle, (See Fig. 6.) into two parts, fo that the fum of their verfed fines may be equal to a given right line, u f ConftruBion. DIVISION Of A CIRCL1. gJJ Conflfu&ion. • Draw the radius AO, and the tangent BE; in A O take Diyifion of an A I equal to the given line, u ; and making I V perpendicular *xh ofacircle to A O, let it meet BE in V ; xlraw F V to bifecl: the angle having thwr **■ E V I, and let it cut the given arch in F; then will AF, F B, flne8> or cofines, betherequiredarcl.es. £$6** Demonftration. Draw the tangent AG, which is parallel to I V, alfo make F P, F R perpendicular to A G, B E, and let P F produced meet I V in H. Then fince AG, IV, are parallels, and the angle H P A is right, FHV is alfo a right angle, (by Euc. 29. I.) there- fore it is equal to the angle F R V, (by conftruction.) But the angles R V F, HVF, are alfo equal, (by conltruc- tion) ; confequently the triangles R F V, HFV, are equi- angular ; and they have one fide common, namely the fide V F ; therefore F R = F H, (Sue. 4. VI.) and PF-fFR = PH=AI, (Euc. 34?. I.) =z u, (by conftruaion.) But the fum of the verfed fines of AF, FB, .is equal to P F -f F R, (by Prop. I.) therefore this fum is equal to the given line, u. Q. E. D. Limitation.— -If A I be greater Mian the verfed fine of the whole arch A B, the point F will evidently fall in the oppo- site fegment, and the confiruclion will be impoffible. Again, fince the angle I VE is equal to the angle A O B, draw the radius O C, to bifect the angle A O B, and it will evidently be perpendicular to VF; therefore L C, a tangent at C, will be parallel to V F ; confequently if A I be fo taken* that V may lie in B L produced, the conftru6tion will alfo be impofiible; which will therefore happen when u is lefs than twice the verfed fine of the arch A C, or B C. Carol. Since the fum of the verfed fines of two arches is the fame with the difference of the diameter and the fum of the cofines, if the latter fum be given the problem may be conftrucled by the laft proportion. Proposition VII. Problem. To divide A F B, a given arch of a circle, (Fig. 7.) into iwo parts, fo that the fum of their fines may be equal to a given right line, iv f Conftruftion. 232 DIVISION OF A CIRCLE." Conjlruction, Ptvifion of an Draw the radii A O, OB, and the tangents AG, BE, in fntotwoparts^ Wh'ch take A S' B T' each e(luaI t0 the half ot" W J dfaW having their ' S N, T N, parallel to AO, OB; and through their inter- fmes, or cofmes, feflion, N, draw N F, parallel to ST, to meet the arch in given ratio.' ?» then A F, F B, are the parts required. Demonftration. Draw F K, F M, parallel to N S, N T, and let them meet S T in K, M, and A G, B E, iii P. R ; then it is eafily proved that the triangles K F M, S N T, are equal and fimilar, and that K M zz S T ; confequently SKrTM. But the angles K P S, M R T, are right, being equal to the angles O A G, O B E, by conftru&ion ; and the angles K S P, M T R, are equal ; therefore the triangles PSK, R T M, are equiangular, they are therelore equal, (Euc. 4. VI.) becaufeSKzzTM; confequently S P zz R T ; there- fore A P -f B R zz A S + B T zz w. But the fum of the fines of A F, FBzzAP + BR; this fum is therefore equal to w. Limitation. — Join A B, which will be parallel to S F, alfo let the radius O C bifed the angle A O B, when properly produced, or not, it will pafs through the point N. Now if N be in O C produced, N F, being parallel to ST, or A B, will not meet the circle ; on the other hand, if N lie beA tween O and A B, F will be in the oppofite fegment of the circle, confequently the construction is impoffible, unlefs N fall between C and the line A B, or in the verfed fine of half the given arch : Thefe things being premifed, it will be eafily perceived that the fine of the arch A F B is the lefs limit of the problem, and twice the fine of A C its greater Y-nit. Concerning STATE OF THE SAP IN WINTER. 233 II. Concerning the State in ivhich the true Sap of Trees is depofited during Winter. By Thomas Andrew Knight, Efq*. IT is well known that the fluid, generally called the fap in The common trees, afcends in the fpring and fummer from their roots, fprinVandfum- and that in the autumn and winter it is not, in any confider- mer, but not in, able quantity, found in them ; and I have obferved in a former wincer' paper, that this fluid rifes wholly through the alburnum, or fap-wood. But Du Hamel and fubfequent naturalifts have proved, that trees contain another kind of fap, which they have called the true, or peculiar juice, or fap of the plant. True or peculiar Whence this fluid originates does not appear to have been faP agreed by naturalifts ; but I have offered fome facts to prove that it is generated by the leaf f ; and that it differs from the common aqueous fap owing to changes it has undergone in its circulation through that organ : and I have contended that from this fluid (which Du Hamel has called the Juc propre, and which I will call the true fap,) the whole fubftance, which is annually added to the tree, is derived. I fba!l endeavour in exifts in the the prefent paper to prove that this fluid, in an infpiffated j b"rnum; * r r r " during winter: ftate, or fome concrete matter depofited by it, exifts during Its fubfequent the winter in the alburnum, and that from this fluid, or fub_ de^inat,0ft n t-rrii-i r l- r -i-i pointed out. itance, diflolved in the alcending aqueous lap, is derived the matter which enters into the compofition of the new leaves in the fpring, and thus furnifhes thofe organs, which were not wanted during the winter, but which are effential to the further progrefs of vegetation. Few perfons at all converfant with limber are ignorant, that That wJnter or the alburnum, or fap-wood of trees, which are felled in the autumn felled autumn or winter, is much fuperior in quality to that of other T°d haS ,ts . ' n J alburnum more trees of the fame fpecies, which are tuffered to fland till the firm, &c fpring, or fummer: it is at once more firm and tenacious in its texture, and more durable. This fuperiority in winter- commonly at- felled wood has been generally attributed to the abfence of the X*kmrt th* lap at that feafon ; but the appearance and qualities of the fap : * See Phil. Tranf. of 1S01, page 336. | Philof. Tranf. 1805, p. 88. wood 23-fc STATE OF THE SAP ftf WlNTEK. wood feem more juftly to warrant the conclufion, that fome —but probably fubftance has been added to, inftead of taken from it, and to its prefence. . -, ... „ ^ . many circumftances induced me to fufped that this iubftance is generated, and depofiled within it, in the preceding fummer and autumn. Full grown Du Hamel has remarked, and is evidently puzzled with the »oftSpPlentlifu ,. , ' , , ,/• been noticed, kinds, and more Ipeedy in others; but no one has yet obterved but not the va- whether it had any dependence on the constitution of the at- xiations from the r . , , _ . „ c . , r . . ftate of the air, motphere, the electric Hate or the air, the quantity ot caloric &c. it contained, if it was always the fame in any one fait, and if it regularly became weaker in proportion as faturation ap- proached, neither have any tables been, yet prepared, which might indicate the degree of deliquefcence, or of efflorefcence of the different falts. Of the hypothefes which could be made on thefe pheno- mena, the following feemed moft probable. Hypothefes that The falts which deprived the air of its humidity ought to ftoukTlttraa*118 a6t in this rerPe& in proportion to the quantity of water which water in propor- the air held in folution or in fufpenilon. The greater the no- tion as the hy- midity of the air, the more fhould the deliquefcent falts aug- grometer indi- -. »-,•>'« , , r , • •,«,., cated its pre- ment in weight, to that the degree or their weight fhould be fcnee. conformable to the 'progrefs of the hygrometer. Barometrical On the other hand atmofpheric preffure, which more or lefs c anges an oppofes evaporation, ought to have an influence on thefatura- * Journal de Phyficrue, LX* tionv ON SALTS* 241 Iron of the falts, fince It caufes thedcnfity of the air to vary; confequently there (hould be an agreement between the vari- ations of the barometer and (he deliquefcence of falts. The variations of temperatures, by dilating, or by conden- — thermomctri- fing the mafs of the atmofphere, fhould alfo occafion changes Jal &<>*]& alfo -7, . , , r ...... , i - i have their influ- in the proportion ot water abforbed by the ialts, on which ac- ence# count it would be ufeful to obferve the thermometer. I thought moreover that one fait had not only more or lefs Deliquefcent attra&ion for the water contained in the air than another, but falti fhou'd ar" .i i- ^- - . ,., •/--,/- r • • • tract moft when, that this attraction varied likewile in the lame talt in proportion ieaft faturated. as it had loft or abforbed water. I hoped by thus comparing the deliquefcence and efflorefcence of falts with the ftate of the different meteorological inftruments, to obtain refults fuffi- ciently conftant to eftablifh a theory of deliquefcence or ef- florefcence. I hoped alfo to be able to ufe the falts themfelves as inftruments of meteorological obfervation ; but experience Experience did. proved that reafoning apparently founded on the trueft theory ^/""ofSon frequently deceives expe&ation. It is neverthelefs neceffary to attend to negative facls, which fometimes areas ferviceable to fcience as thole of a pofitive nature. I did not find a tingle fait which feemed to have the Ieaft None of the falts conformity with the ftate of the barometer, hygrometer, or^'f^.V1'11 J _. ■ '■ . J ° or lofe weight in thermometer. Gn the lame day many falts increafed confider- conformity to ably in weight, while others indicated a flow progrefs. Some11^01"10 had but a fmall attraction, when the hygrometer {hewed a great degree of humidity, and were moft deliquefcent when the air feemed moft dry. Atmofpheric preffure never had the Ieaft agreement with the increafe of weight of a fait, and the thermometer having varied but half a degree during the courfe of the experiments, does not furniih any obfervation on the influence of temperature. It is therefore impoffible to explain by the meteorological changes any of the variations which I obferved in the deliquefcence, or the efflorefcence of falts. Efflorefccnt Salts. I weighed exa&Iy 288 grains of fulphate of foda, of phof- Experiments. phate of foda, aud of carbonate of foda, which three falts are fLts^phlte, confidered as the moft efflorefcent, and placed them in a dry phofphate and and airy fituation, after having carefully dried the capfules ^rpb^e of foda which contained them. I put alfo in the fame place an hygro- meter, a barometer, and a thermometer : the three ialts fhewed the following refults. Vol, XII.— December, 1805. R Sulphate 242 Off SALTS. X*ofs of weight in each by efflo- rescence. Left to efflorefce. Loir. Sulphate of foda - 61 days - 203 grains of water. Phofphate of foda - 39 - - 91 Carbonate of foda - 5 1 - - 86 It mould feem from this table that thefe three falts ought to be clafled in the preceding order ; but it muft be obferved that falts contain more or lefs water, in proportion as they cryftal- Confiderations ize flowly or*rapidly. The number of days which were em- ieemsto Sate pl°yed in the efflorefcence of thefe falls thould vary, both in no ufeful refult proportion to the water they contained, and to the extent of in deliquefcent mr face which they expofed to the aaion of the furroundinsr falts expofed. ,,,-,. r * ■ ^ r • air; ana thereiore the time or their emorelcence can give no appreciation of the force of their attraction for water. This reflection prevented my making experiments on any more ef- florefcent falts. - . , Deliquefcent Salts. I took 288 grains of each of the falts in the following table, (which are very fenfihly deliquefcent, fince they all abforbed more than half their weight of water), and placed each of them in a dried capfule, along with the before-mentioned me- teorological instruments, in a damp Situation, and after 150 days of obfervations noted what is included in the table. A Table of Deliquefcent Salts, in ike Order of their Attraction, ejliinated by the Quantity of Water abforbed. Days employed their fat u ration in Water abforbed. Table of the Acetite of potato increafe of Muriate of lime weight in each of », • . r r 19 different fpe- Muriate of manganefe eies, and the Nitrate of manganefe tjmeardpeft. Nitrale0f zlnc t •( it 146 124 105 89 124 * 700 grains. 684 629 527 495 ivcjjr. Nitrate of lime Muriate of magnefia - 147 139 £ 443 441 Nitrate of copper - 128 * 397 * Muriate of antimony Muriate of alumine - 124 149 •* 388 342 Nitrate of alumine - 147 - 300 • Muriate of zinc - 76 - 294 Nitrate of foda - 137 " 257 * Nitrate of magnefia 5 73 " 207 Acetite ON SALTS. Davs employed i their faturation. n Water aWbrbed. Acetite of alumine • - 104 - 202 Acid fulpliate of alumine - - 121 - 202 Muriate of bifmuth - - 114. 174. Acid phofphate of lime - - 93 - 155 Muriate of copper - . 119 - 14S 243. In examining this table it may be remarked that the dura- The times of ab- tion of the abforplion is not in any proportion to the quantity : ^ApmZn\^nl The muriate of alumine, for example, took 149 days to abforb to the quantities. 342 grains of water, while the nitrate of manganefe took but t 89 days to abforb 527 grains. That the force of attraction may beeftimated from the rapidity with which the bodies unite mud not be concluded from this ; for the fame table fhews that nitrate of magnefia faturated itfelf in 73 days, and only ab* forbed 207 grains of water, a much lefs quantity than that taken up by the nitrate of manganefe. Although the greater or lefs Though the ra- facility with which deliquefcent falls faturate themfelves with Son does not°in* water cannot be accounted for, (fince a fait half faturated, or dkate the pro- half deprived of water, is no longer the fame body, and con- ^^^2 fequently exercifes other attractions than what the fame fait ufeful. does in its ordinary Hate, or in a different ftate of faturation,) the rapidity of their faturation is not however an indifferent matter. In the experiments which have been made on pro- ducing artificial cold by muriate of lime, it has been remarked that the cold was greater in proportion as the ice was melted; but it is probable that the muriate, and above all the nitrate of^or'nftance>^e manganefe, which becomes liquid much quicker, would pro- *& may^ro* dnce with ice a more intenfe cold, and that certain liquors duce intcnfe re» which have hitherto refitted coagulation, would be folidified nSeratl0fl* by thefe two falls, which experiment is highly deferving of a trial. ^n order to examine whether deliquefeence depends on the It does not ap- proportion of the bafe, or of the acid which conftitutes the f.ear fhat th* de- falts, I compared with each other the different analyfes of falls pcnds on the publifhed by Bergman, Klaproth, Fourcroy, and Vauquelio, ProPortion °* and I faw that no induction could be from their compofttion ; part8> tor there are fome falts which have the bafe in a very conlider- able proportion, and which are lefs deliquefcent than fhofe whofe bafe is lefs; and many others in which the acid is in a fmall proportion, are more deliquefcent than thofe, in which this principle is predominant. The nature of the acids and of R 2 th* 24^ °1* SALTS. — nor on the pc- the bafes themfelves do not throw more light on the pheno- thelnTeiient^ mena °^ del'queicence than their proportions; for there arc themfcltes. deliquefcent falts,, the component parts of which taken fepa- rately, have not any remarkable .attraction for water, fuch is the nitrate of alumine; while on the other hand the fulphate of foda is efflorescent, although concentrated fulphuric acid, and cauftic foda each feparately attract humidity. Nothing better proves this axiom in chemi ftry, —Compounds have pro- perties peculiar to themfelves, and differing from thofe of their component parts. Generally the In general deliquefcent falts encreafe their weight in a di- dehquefcence nrinjfhing proportion, according as they approach faturation; when the fatu- thus the acetate of polafh, which in the hrft twenty days ex- «tion was leaft. hibited the following progreffion: 21. 34. 44. 54. 60. 70. S5. 100. 110. 120. 128. 138. 142. 148. 160. 169. 177. 186. 192. 198. did not (hew on the laft twenty days more than this, 647. 650. 655. 660. 663. 666. 669. 671. 676. 682. 684. 686. 688. 690. 692. 694. 696. 698. 699. 670. The falts which were but little deliquefcent preferred a lingular phenomenon, which none, I believe, has obferved before. Remarkable The acid fulphate of alumine, and the acid phofphate of facts s falts ljme, increafed and diminimed fucceffively in weight. which lofe part ' . ,,-.,, r cf the abforbed The muriate ot copper diminiQied during 45 days before it water and after- began to encreafe. Thefe ofcillations and retrograde move- more and en- ments take place but once, arid when the fait has abforbed a creafe till fatu- certain quantity of water, there is a progreffive increafe, al- though flowly, until its perfect faturation, which may depend on the attraction of water for water, an attraction which is not perceptible but in certain proportions. Expediency of Thefe anomalies deferve to be obferved again, and corn- further experi- pared with experiments made on other falts which do not ex- hibit them. They tend to make -us acquainted with all the caufes that produce efHorefcence and deliquefcence, fince they prefent each phenomenon fuccefiively. The falts which we fubmitted to their action, had certainly an attraction for water * very little different from that of air in a medium iiate cf heat and humidity. The point of equilibrium muft be decided by the ftate of the a'mofpliere, orA the falts would remain un- altered. Thefe will pro- I ftill however think that a relation exifts between the me- bably fhew that teorolc£ical variations and the alterations of the falts; and if I •mcrpnric vana- ° meteoric vana tions in the air .» '. was IMPROVEMENT OF RYE HARBOUR. ' O^ was not able to difcover it, without doubt this was caufed by do Influence th the (mall portions of falts which I expofed to the a6tion of the ch3ngts in faUs aUnofphere. Some chemift more fortunate vyill determine it, by operating on large mafles, comparing experiments made in many different feafons, and keeping a regifter of the electrical ftate of the atmofphere, of the water of cryftallization which the falts contain, of their divifion, and of the furface which they prefent to the air. In a labour which would require more than 3000 experi- Extenfive re- ments, the i;^vv fads which I have obferved are too few, earc * and perhaps too little important to engage any one to under- take fuch prolonged and minute experiments; but I have given a table of deliquefcent falts arranged according to their attraction for water, and I dare hope, that the refults of it w ill not be altogether ufelefs. IV. Account of the fmple and eafy Means by which the Harbour of Rye xvas rcftored, and made navigable for Ships of confiderabk Burthen. By the Rev. Daniel Pape *. Memorial of Rye Harbour. JtvYE Harbour, once fo very fafe and convenient for pafllng Decayed ftate of yeflels up or down the channel, to run to in diftrefs or in pre-. ye H,arbour* . r in 1796. carious weather, had been for many years, and from various caufes, in a gradual ftate of decay, infornuch that in the years (I believe) 1795 and J796, it was thought neceflary to fend Captain , from the Trinity-Houfe, to make a furvey, and report to the Board its then ftate, and the pro- Survey and bability of its improvement or redemption. The furvey wasrePort> made, I believe, with confiderable care and attention ; and the refult was, that the harbour was pronounced loft, or in that the Harbour fiich an irreparable decayed ftate, that it was an ufeIefsWas irreParab,e' expenfe to the (hips palling, which paid tonnage to it ; and therefore this tonnage was taken from Rye, and given to Ramfgate Harbour, leaving however a referve in the hands of tjie commiffioners of 6000/. * From his communication to the Society of Arts, who voted fcim the gold medal. See their Tranfa&ions, Vol. XXII. ThQ • ' £4-6 IMPROVEMBNT OF RYE HARBOUR. Adveitizement The confequence of (his was an advertifement, inviting provcmcnt. im" anv gen^eman to come forward with plans for the improve- ment of the harbour, and the draining of the upper levels. On the clay appointed for the prefentation of fuch plans, a very fenfible letter was laid before the Commitfioners by the Rev. Mr. Jackfon, of Rye, though impracticable on many The authoi's accounts, — and alfo a plan by myfelf, propofing to make the dinft-uiL and Prc^ent cut> and to *orm a dara °f foaw or hay and faggots, dam up the old as reprefented on the chart, for the fmali fum of 500/. On mouth. reverting to the enormous jums that had been already, from time to time, expended by able engineers to no purpofe, it was judged at the moment an impoffible attempt; and, after politely voting me their thanks, the Commiflioners feemed to The author decline carrying their plan into execution. — This, however, hifowTrifue* did n0t faiisfV me> a,ld therefore> confident of fuccefs, I undertook to perform what I had propofed, or lofe (he money, without ftipulaiing for any fee or reward (hould I fucceed. On entering upon this agreement, 1 fet to work, and choofing a Mr. Southerden, an active and perfevering man, as foreman, to affift me, I completed the work in three months, in the very depth of winter, at the expenfe of only 480/. though the ' works were twice filled up with fea-beach by the tides. and completed But, though thus was done to the aftonifhment and admiration of many, yet there were evidently an envious few mortified Farther feeurity and difappointed. The cut and dam being thus finifhed, it by a p/erhead was then thought necefiary, on my recommendation, to fecure andjutties, , r °. -,,,„ , •.. the cut from reverting to its late reduced ltate, by a pier-head on the eaft, and jutties on the weft fide of it; the execution of which was committed to the eminent (kill of a Mr. Suther- land, who performed the trull repofed in him, to the univerfal fatisfa&ion of his employers ; and I believe the whole was completed for forpething lefs than 3000/, in a very mafterly It proves to be and workman-like manner. Of this I think there cannot be bkfeaiy dJra" a better Proof adduced» than that il A111 ftands firm> without the lea ft apparent decay, and maintains its firft pofition without the fmalleft variation: and no doubt a very trifling annual expenfe will keep it in its prefent improved ftate. and admit fhips The advantages derived from it are particularly great; for of hve times the mjps of 260 tons burden, and even vefiels of 300 tons, run tonnage before " . gaxpitted. in with the greateft fafety at fpring tides : whereas, before, thofe of 50 tons could not pome in, but with the utmofi dif- ficulty and danger, That IMPROVEMENT OF RYE HARBOUR. 24? That part of Romney Marfh too, which lies contiguous, Other adv-m- and was threatened by every boifterous tide with a total over- taSes* flow, is now in fafety, and the drainage of the levels is rendered complete. I beg leave now to offer to your attention a fliort defcrip- Very eafy and tion or the Dam, the, form and materials of which may be method0fcon. uted with fuccefs in fimilar fttuations, whether in places ftru&ing the adjacent to the fea, or in gentlemen's nth-ponds, or rivers indam* the country, where weirs may be neceiTary for the prefervation a double roof or of the banks. The dam was merely formed of hay, ft raw, covering of hay, and faggots, pinned down to a foundation of /and or filt by ^nW*!0^"ncd fhbrt piles. I formed it as in the chart, of the fiiape of a foundation of doubfe-roofed houfe, firft putting down ftraw, and then over fand» &?« it hazel faggots, from 12 to 14 feet in length, and afterwards pinning down the whole with piles. I next filled the (pace The interface between the two roofs with gravel or fea-beach, and fecured J^J^n* this alio with faggots pinned down upon it, over which re- covered with iiftance being precluded from its peculiar form, the influx *ja§?ots fecure4 and reflux of the tides glided lb gently, that consequently every probability, not to fay poflibility, was annihilated of its being ever undermined or blown up. It was alfo necefiary that this dam fhould be put down in Difficulty that one tide, and that the mouth of the cut fhould be opened in £^ J^bL the fame time; for it was evident to me, that it was impoffible an the jilt brought in by Succefsfuj the tide; which being repealed by" each returning tide, the rcfult* dam foon became entirely fixed, beyond a poflibility of ever being deftroyed ; and it is now fo entirely covered, that if the pier is kept in lepair, the dam muft ever remain unimpaired by time, and proof again ft the molt violent floods of waters. For this work, the Commiilioners voted me fifty guineas The author's Jhaif of which I gave to my aftiftant) and alledged tfi£, on ^S^Jj*^ account . 24-8 ' INPROVEMENT OF RYE HARBOUR. attending the account of the lofs of the tonnage, and the poverty of the works: 50I. . fan&t tjiev were corry it was not more. This to me, under thefe circumftances, was a fufficient apology, and I was con- tent. I now offer it to the conftderation of the Society of Arts, as a body in fome degree interefted in the profperity of this kingdom. Should they deem what I have already re- ceived an adequate compenfation for fuch a work, and fuch an undertaking, at fo inclement a feafon, I am ftill content. But if they fhould think proper to grant me an additional remuneration, it will be received with peculiar fatisfa&ion, and confidered as a very great honour by, Sir, Your obedient and humble Servant, To Charles Taylor, Efq, DANIEL PAPE. ) Cambridge, Trinity Hallt April 2, 1803. Reference to the Engraving of the Rev. Mr. Pape's Improve- ment of Rye Harbour, Plate XIII. Fig* 1. AA. The double roof, filled with ftraw. BBB. Hazel faggots, 12 to 14 feet long. C. The fpace betwixt the roofs filled with gravel or fea* beach . D. The faggots which covered the gravel fo laid. E. Piles of wood driven through the faggots and ftraw into fc'arth, at the bottom of the river, the heads of which piles are united by crofs pieces of wood. F. The folid bed of the river. G. The river at low water. H. The high. water mark. I. The upper fide of the dam, which oppofes the current of the river, K. The lower fide of the dam, which refills the coming-in of the tide. Fig. 2. L. Shows the place where the dam was placed. M. The old courfe of the river reprefented by dotted lines, and which is now filled up with gravel by the tide. N. The new canal, cut by Mr. Pape's directions, anil which is now the regular channel for (hipping. O. The PFAFF ON RESPIRATION. S&49 O. The pier.head, on the eaft fide of Mr. Pape's cut. « PP. The two jutties, on the weft fide of Mr. Pape's cut. RR. The former canal, cut under the dire&ion of Mr. Smeaton, and other able engineers ; but which failed, and is iince blocked up by a bank made acrofs it, over which the prefent high road between Rye and Winchelfea patfes. New Experiments on the Befpiration of Atmofpheric Air, prin- cipally zvith regard to the Abforption of Azote, and on the Jlefpiration of the Gufeous Oxide of Azote. By Profejjbr Pfaff, of Kiel *. .1 He great difcoveries in pneumatic chemiftry, the ingenious Short hiftory of and ufefui applications of thefe difcoveries to explain *ne ^-Xf con- phenomena of organized beings, particularly the animal cerning vefpira- economy, and the valuable refearches of eminent philofophers tlon* have greatly contributed to throw light on the doctrine of the chemical effects of refpiration. In confequence of thefe refearches, phifiologifts are in general agreed with regard to the mod eflential points of this doclrine ; fuch as the produc- tion of carbonic acid, the ufe of oxigen gas, and the animal heat which refults from its abforption. But the activity of philofophical enquirers has not yet fucceeded in removing all the obfeurities of this fubjeel, and the difagreement between the refults of various experiments relating to them, fufficiently ihew, that new enquiries are requifite to afcertain the fources of fuch errors as ftill continue, and to remove them altogether. The experiments of the celebrated Davy have done much D.avy on . in this refpect, and the refearches on the nitrous oxide afford a new epocha in the chemical doclrine of refpiration. The celebrated editors of the Bibliotheque Brittannique, have thewn their conviction of the great value of thefe refearches^ by the ample and inftructive extract they have given, and th& manner in which Berthollet in the 45th volume of the Annates de Chemie has given an account of the fame, has fufficiently flxed the attention of philofophers on that excellent work. * This memoir was addteffed to the French National Inftitute, and read at theiv fitting of the 25th of Meflidar laft (July 13.) The gSO PSAFF ON RESPIRATION. The differences which exifted in the refults of former ex- periments, as to the quantity of carbonic acid produced in the act of refpiration were lets important, and might entirely depend on the conftitution of the different individuals upon whom the experiments were made ; and under this point of view, a revifion of the experiments was lefs neceiTary. But the part which is performed by azote gas in the acl of refpiration has been too little attended to. It has been generally fuppofed to be altogether without activity. Goodwin alone thought he had obferved a considerable abforption of azote gas ; but his experiments lyere not made with all the neceiTary accuracy, and were too directly oppofite to the experiments of Lavoifier, Seguin, Abernethy, Fothergill, Azote necefi'ary Menzies, &c. to fix the attention. The experiments on the combuftioa of ^ow combuftion of phofphorus, which does not fucceed in phofphorus. pure oxigen gas, but is fo greatly forwarded by the prefence of the azote gas of atmofpheric air, {hew to a certain degree the advantages which this great quantity of azote gas is likely to produce in refpiration ; and the unfortunately too concife refults of the laft experiments of the immortal Lavoifier on refpiration, in which it was found, that a much greater mafs of oxigen gas is decomposed in the fame time by ref- piration in atmofpheric air than in oxigen gas, ftand in con- firmation of the former facl. But hitherto we have potfeiTed only probabilities, or refults not fufiiciently connected with the fubjecl. To Davy it is that we are indebted for an exact and inconteftible knowledge of the a&ive part which azote gas performs in the procefs of refpiration. But in proportion to the novelty and interefting nature of thefe refults do they require to be confirmed by the experiments of others ; and it was in this point of view that I undertook laft winter a feries of experiments upon refpiration in atmofpheric air, and aifo in the gafeous oxide of azote ; the principal refults of which I now venture to communicate to the National Inftitute. . Experiments on the Refpiration of Atmofpheric Jir, and Oxigen Gas. Experiments of All the following experiments were made in the academical refpiratien. laboratory of the Univerfity of Kiel, which is provided with all the accurate apparatus of modern chemiflry, They were made PFAFF ON RESPIRATION 251 made for the moft part in the prefence of my pupils, par- ticularly one named Dierks, who was moil commonly the Tub- ject of experiment. In order to determine with precifion the changes which atmofpheric air undergoes by refpiration, and to decide re- fpecling the abforption of azote gas, we muft begin with ascertaining the diminution which a given volume of air undergoes by refpiration. Thisfirft point was to be determin- ed by accurate experiments. 1. The quantity of 170 duodecimal cubic inches of Paris* Quantity of were refpired from one of the great refervoirs of a gafometer, un(jergone j,y conducted at Paris after the model of that of Charles, over air by the water covered with oil, to prevent the abforption of thejjr^^ xe*" carbonic acid gas produced by refpiration. The refpiration was performed once only during the time of ten or twelve feconds. The diminution was 4,72 cubic inches, or -^ part of the firft volume. This experiment being repeated twenty times in the fame manner, afforded the fame refultf. 2. 144- Cubic inches were refpired once in the fpace of ten or twelve feconds. The diminution was four cubic inches or jJs part of the primitive volume. 3. The fame volume was refpired twice during 22 feconds, and the diminution amounted to eight cubic inches, or T*¥ part of the primitive volume. The fame volume having been refpired three times during 30 feconds, the diminution amount- ed to 12 cubic inches, or ^ part of the primitive volume. 4. 60 Cubic inches were refpired three times during 23 feconds, the diminution was fix cubic inches, or f5 of the primitive volume. 5. 170 Cubic inches were refpired four times during one minute, and the diminution amounted to 20 cubic inches. This experiment was feveral times repeated, and the dimi- nution was almoft conftantly the fame. Namely, IS, 19, 21 , and 20 cubic inches, or T*7. 6. 168 Cubic inches refpired during 50 feconds, by four great and four fmall refpirations, fufTered a diminution of 14, or T\- of the primitive volume. 7. 430 Cubic inches by 12 refpirations in 90 feconds, fufFered a diminution of 24, or -^ part. * As thefe quantities are merely relative, I haye not deduced them, J. Thefe <25Z PFAFF ON RESPIRATION. Thcfe refulls agree very well with thofe obtained by Davy on the diminution of air by refpiration. He found the diminu- tion by one fingle refpiration to be ^ part, and by refpiration continued for one minute -±s part. The magnitude of the diminution depends not only on the time during which a given volume of air is refpired, but principally on the magnitude of this volume itfelf ; it rauft be proportionally Iefs the greater the quantity of air infpired. A very efTential error is feen in the refults of Abernethy, who gives a greater volume to the expired than to the infpired air; and the calculations of Goodwin are founded on a miilaken bafis; for he fuppofes the two volumes equal. Diminution of jn or(]er to determine comparatively the diminution of refpiration. oxigen gas by refpiration, 170 cubic inches of oxigen gas obtained from manganefe were refpired in the fame manner, and under the fame circumftances as the 170 cubic inches of atmofpheric air in the 5lh paragraph. The diminution amounted to 30 cubic inches, and in other experiments, to 33, 29, 31. The mean term of which is T2T parts of the primitive volume. This diminution being eftablifhed with accuracy, may be applied to determine the abforption of azote gas. Experiments to 8. SO Cubic inches were refpired one time llowly during determine how t or 12 fec0nds, and the air expired was received over much azote is * abiwbed in the mercury. procefs of ref- ji^ relative quantity of the conftiluent parts of this refr piled air was in the centenary 4,16 carbonic acid, 16,55 oxigen gas obferved by the flow combuftion of phofphorus, 79,19 of azote gas. An eudiometric experiment made at the fame time, gave the following proportion of the parts in atmofpheric air, one carbonic acid, 21 oxigen gas, and 78 azote. The total diminution of the air was from the pre- ceding experiments ^. We may therefore find the true quantity of azote gas by the following proportion, 36 : 35 :: 79,19 : 76,99. If we fubtract this 76,99 from 78, the pri- mitive quantity of azote in the atmofpheric air before ref- piration, we find a lofs of 1,01 on the hundred parts of the whole mafs of air breathed. But as the quantity of air in- fpired was really no more than 80 cubic inches, the abfolute djrr;n,ution or difappearance of azote gas by one refpiration^ muft fcFAFF ON RESPIRATION. -*^3 mult be diminifhed in the fame proportion of 100 to 80, and thus proves 0,803 cubic inches. y. In another experiment 60 cubic inches were refpired once in the time of 10 or 12 feconds, and the lad portion of the expired air was received over mercury. The proportion of the conftituent parts after refpiration, were in the centenary 4,68 carbonic acid gas, 17,68 oxigen gas, and 77,74 azote gas. An eudiometric experiment made at the fame time on the atmofpheric air, gave I carbonic acid, 22 oxigen gas, and 77 azote gas. The true quantity of azote gas found as before, by diminishing the 77,74 T^, is, 75, 5S. And this being fubtracled from 77, the quantity of azote gas previous to the refpiration leaves 1,42 for the azote which difappeared, fuppofing the refpired air to be divided into 100 parts. Bat if we take the real number in inches, which was 60, this quantity will be exprefled by 0,852 cubic inches. 10. 30 Cubic inches were refpired in the fame manner three times during 16 feconds. The expired air contained in the centenary 5 ^carbonic acid gas, 14,5 oxigen gas, arid 80,5 azote gas. The atmofpheric air contained by experi- ment at the fame time, 1 carbonic acid gas, 29,75 oxigen gas, and 80,025 azote gas. This by the fame procefs of computa- tion gives, a diminution of 4,235 in the 100, or in cubic inches 1,2705. Thefe experiments which were feveral times repeated, and Remarks™ constantly with the fame refult, deciiively fliew that azote 3^, gas is abforbed in the aft of refpiration, and the active part it performs. Hence we may more eafily underftand, why azote gas compared with other mephitic gafes is lb little noxious to our lungs ; fo that according to the experiments of Lavoiner and Seguin, animals live very well in a mixture of 15 parts azote gas, and one part oxigen gas ; whereas the fame animals were fuddenly fuffocated in a mixture of 40 parts oxigen gas, 45 azote gas, and 15 carbonic acid gas. Hence we may i comprehend, at leaft to a certain extent, the extraordinary ehWts of the gafeous oxide of azote; we may form fome notion of the transformation of the chyle, which is lefs anamalized or azotized in the lymphatic part of the blood, but becomes more fo in the act of refpiration. But the quantity of azote gas abforbed by one (ingle refpiration is not very confiderable, v\ hich 254? PFAFF ON RESPIRATION. "which agrees perfectly with the experiments of Davy, who found that no more than 5,1 cubic inches of azote gas were abforbed by 19 refpirations of a volume of 161 cubic inches. Experiment* II, To determine the quantity of carbonic acid gas pro quantises of duced by the refpiration of atrnofpheric air, 60 cubic inches carbonic acid were refpired once during ten or twelve feconds, and received ■intioa m ^ " over mercury when expired. Lime water abforbed 4,68 parts in 100. Tins experiment being feveral times repeated gave the fame refult. The laft portion of expired air being feveral times transferred through lime water was dimiuilhed 4,9 parts in 100. 12. 20 Cubic inches refpired three fucceffive times during 10 feconds afforded no more than five hundredths of carbonic acid gas. 13. 170 Cubic inches were refpired four times during 50 feconds, the quantity of carbonic acid gas obtained was 5,8 hundredths. 1+. 1^0 Cubic inches were refpired from a bladder eight times in one minute. Lime water abforbvi 8,2 hundredths. This quantity of carbonic acid produced by refpiration, afforded a term of comparifon to afcertain the quantity of the decompofition of oxigen gas in refpiration from the fama quantities of atmofpheric air, and of pure oxigen gas. Oxigen gas The preceding experiments (7) had (hewn that the diminu- producesmore tion of oxigen gas was more coniiderable than that of atmofc refpiration^than pheric air. From this faft it might be expected, that that atmofpheric air production of carbonic acid gas would likewife be more con- ^" fiderable; and this was confirmed by direct experiments. 15. 170 Cubic inches of oxigen gas obtained from man- ganefe, were refpired four times during 50 feconds; the diminution was 30 cubic inches. The quantity of carbonic acid produced was 8,2 hundredths. Atmofpheric air refpired an the fame manner, and under the fame circum fiances, gave only 5,8 carbonic acid. 16. 70 Cubic inches refpired from a bladder during 50 feconds, alfo gave eight hundredth* of carbonic acid. Experiments on the Refpiration of the Gafeous Oxide of Carbon, Obfervatlons on The gafeous oxide of azote was obtained by the procefs of the method of p from CTyfa\\\zed nitrate of ammonia. This nitrate of obtaining J J gafeous oxide of ammonia affords very different products in different tem- axotc. peratures. PFAFP OW RES P4 RATION, Y <235 peratures. I have made a confiderable feries of experiments on this i'ubjeft, which I (hall ftiortly fubmit to the National Inftilute. I (hall only remark in this place, that the oxigenat- ed muriatic acid is obtained at the commencement, if the nitrate of ammonia be not entirely free from muriatic acid* that at a temperature not exceeding 220 degrees of ths centigrade thermometer, the gafeous oxide of azote is obtain- ed in great quantity, and very pure, without any mixture of ♦hole white vapours which have the taite of milliard; but that a temperature ftill higher, efpeeially at a red heat, the gafeous oxide of azote is no longer difengaged but nitrous gas is formed, and very peculiar white vapours which I am, at prefer) t examining. To prevent any exploiion, I always mix the nitrate of ammonia with very pure fand. To obtain the gafeous oxide of azote in a very pure itate, the diftillation. ttjuft be made on a fand bath, and the fire carefully managed. When every thing fucceeds properly, the gas is fo pure, that it may be refpired immediately; it has an agreeable taftc, almoft facchar vinous. If it be mixed with the white vapours produced by too ftrong a heat, time muft be allowed for them to be depofited. The effects which Davy has obferved, Davy's experl- and Piotet has defcribed with fo much interest in his fecond perfci^iy with, letter in the 17th Volume of the Bibliotheque Britannique, our author. were perfectly confirmed in my experiments. Several peffons who refpired this gas were exalted abfolutely in the fame manner. One of thofe who refpired it was very fpeedily in- toxicated, and put into a very extraordinary and mofr agree- able extacy. Others refitted fomewhat longer; one only feemed to be fcarcely at all affected. The exaltation arvvays patted over without leaving any perceptible relaxation. J ftill continue thefe experiments. Perhaps this gas may be- come a powerful remedy for melancholy aflfeclions. I (hail not fail to communicate the refults of my experiments to the National Inftitute. VI. Experiments Q56 6tJJ* -ARABIC AND GTJM ADRACANTH^ VI. Experiments on Gkm Arabic and Gum Adraca'nth. By M, Vauquelin *. Red gum adra- JL EN" grams of red gum adracanth produced on combuftion combuftion^f tl,ree digrams and a half of white allies. Thefe allies hundredths diflblved in muriatic acid with effervefcence, and gave forth ofnmir^t°haean odour of Sulphurated hidrogen. Their folution depofited little iron and a precipitate by ammonia, which was phofphate of lime and nme?11316 Qt °Xide ot ir0n* The oxalate of ammonia precipitated from it much lime. Thus red gum adracanth contains in 100 parts about 3f of aflies, which was compofed for the moft part of carbonate of Jime, a fmall quantity of iron, of phofphate of lime, and perhaps of a very minute portion of alkali. "White gum 2. Ten grains of white gum adracanth fubmitted to the adracanth left a fame proofs, gave three decigrams of alhes, which wese com- which contain- P°fed of the fame principles as the red kind, with the ad- cd the fame dilion of a little potafh. prmc^ples and fr Ten gft|n| of gQm ^^^ hmnt ^ ^ ^^ ]eft thrce Gum arable left decigrams of afnes, which were compofed of the fame 3 containing no e|ements as t^e preceding, except that they gave no fign of the prefence of alkali or of fulphur. Opacity and I formerly thought that the opacity of gum adracanth, and difficult folu- the difficulty of its folution in water, might be occafioned by bility of gum ,". „ , , r , r adracanth. a greater proportion of earthy matter; but after thele ex- periments it appears, that they are due to another caufe. The lime in Tof beet root with Si ounces of fulphuric acid diluted of ^ulPhur'c "■<* J . . * . r is added to the with one pound of water ; then pour it off, and let it ftand juice, and after for 12, 13, or 24 hours; 12 hours are fufficient, but 24 will Ending i-izth ... . . r 1 • . of wood ames, not be detrimental to the procels, as the acid prevents any and one part of change in the juice. In order to feparate the fulphuric acid, t'me« The put into the liquor 1\ ounces of wood aflies, to which add ^g^,/ foon afterwards, 2 ounces or 6§ drachms of lime flaked in feparated. water. The fulphuric acid coagulates the albumen, the wood afhes, confitling chiefly of lime, and the lime itfelf feparate in their turn the acid, in form of an almoft infoluble fait. It will here be recollected, that in the Weft Indies, in the fa- brication of coarfe fugar, and in the refining houfes of Europe, lime is ufed to aflift the feparation, and the crystallization of this article. After this firft operation the beet root muft be clarified ; Farther purifr- for which purpofe it muft be poured into a boiler fo placed fation by bo}1* as that the fire may ad equally upon all the whole furface of and' ito^nfr!** the bottom, in which it is to be heated to a ftate bordering upon ebullition, but muft not be fufTered actually to boil. After drawing oytt the fire, the fyrup is to be fkimmed till the lkum arifes in blackifh flakes. The liquor is now to be filtered through flannel, which muft be done with caution, left the dregs pafs through with the fyrup. The Ileum and the dregs are good for fattening fwine* * Van Mons's Journal, Vol, VI. Si Tbm \ '260. Brifk evapora- tion. Cooling and farther purifica- tion by Cub- fidence. Evaporation till the fyrup draws a thread. ACBARD ON SUGAR, CrvftallizaUon or graining in a warm apart- ment. The melaffes drawn oft* leave coajfc fugar. Jmprovsment. The fyrup, thus clarified and filtered, is placed In a (hallow cauldron, to the depth of not more than fix inches, and- evaporated over a brifk fire, whereby it is prevented from becoming a liquid faccharine mucus, which refills all attempts tocryftallize it. When reduced to about one half of its quantity, the fyrup is to be poured into tin vetfels about fix feet in height, and half a foot in diameter, with cocks about fix inches from the bottom. It mutt here be left for two or three days, during which lime it precipitates whatever remaining impurities" it may contain, particularly gypfum. At the end of this period, the liquid may be drawn clear off, and replaced in the fliallow boiler, but only to the height of three inches, to evaporate; the fire to be gradually augmented, as the fyrup thickens, until it be in a ftate of ebullition. The fire* is then to be damped to prevent the fugar from burning, which would render it unfit for cryftallization. When the fyrup becomes fibrous, the fire is to be ex- tinguiftied. In about half an hour afterwards, the fyrup is to be poured into cones, of which the mouths are flopped with linen cloths, and containing a little coarfe fugar-candy, grofcly pounded. Thele cones are fet in a room whofe temperature is from 10** to 20° of Reaumur. When the feveral operations have been dexteroufly ma- naged, the fugar will cryftallize in 24 hours: but if the eva- poration, or baking, has been too hafty, the whole becomes a granulous mafs, with the interfaces filled with melaffes. When the fugar is well cryftallized, the mouth of the cone is to be opened, and an earthern vetfel placed under to catch the melalies : this operation, according as the fyrup has been more or lefs baked takes three or four weeks. The fubftancc remaining in the cones, of a yellow colour, more or lefs tinged with while as the baking has been well or ill conducted, in granulated cryilals of various fizes, is the coarfe fugar of beet-root. Mr. Achard, in order to fave time, and to avoid the ufe of vefiels'for fettling the liquor, afterwards deviated from his original plan, by adding to the fyrup, when half evaporated as above defcribed, for every twelve quintals of roots ufed, - five NEW METAL NICKELINE. 261 five quarts of fkimmed milk, and (hortly afterwards one quart of vinegar. He then proceeded with the fecond eva- poration in the boiler. This fugar by refining may be made to anfwer all the ufes Subfequent re- of that of the Weft Indies, and may be rendered equally fi;iing as ufuaU white by the ufual procefs. IX. On Nickeline (Niccolanum), a Metal in many Re/peels refem- bling Nickel, lately dif covered by Dr, J. B. Richter.* 1 HAVE long fince conjectured in analyfing the cobalt ores Sufpicion of a of Saxony, that they contained, befides cobalt, arfenic, cop- j^™ 1H per, nickel, and iron, another metal which refembled nickel in many fits properties, but the means which I have hitherto employed to feparate it did not before afford me any fatisfac- tory remits. I was chiefly furprifed that nickel, after being purified by Remarkable the liquid procefs from cobalt, iron, and arfenic, and after f?a» that nickel i i • i i. • r n cleared of iron that reduced without the addition of a combuftible body, and arfenic and never formed a mafs, but was always found difperfed in (mall fufcd> is almoft particles in a hard heavy mafs, which had the appearance of final! globules the remains from vitrified copper, This hard matter had no metallic luftre, neither was it at- through a hard, traded by the magnet : Its colour was of a blackith grey on hreeav^^acklfll" the furface, with a fmall degree of brightness ; and in powder it was brown, greyifli, and greenifh. Some weeks ago I endeavoured to reduce per fe almoft half Experiment with a pound of oxide of nickel, which I had purified as well as a ,arSe quantity poffible by the liquid procefs, for the greateft part of a year, nickel, at a confiderable expence : as this oxide was not of a lively green, I thought this was caufed by the •« extractive matter" which might be in the potafh employed for the precipitation of the fulphate of nickel from the ammoniacal preparation : it is true that this triple combination had not that beautiful grafs-green colour which it commonly had ; but I thought this * Annates de Chimie, LXIV\ might £6*5 KKW METAL NICKELI^E. night be caufed by the fubftilution of the potafh to the am- monia mixed with the copper, which could not be feparated but by the reduction per fe. Only a fmall From thefe ideas I hoped to have at leaft four ounces of SSkdVa mafs Perfe<% Pure nickeI» b"1 *"■ difagreeably furprifed by find- was obtained, ing in the crucibles, which were deformed in the ufual "man- ner, and perforated by the vitrified copper, a rough mafs with the appearance I have before mentioned, and which contained only a morfel of about two and a half drams, and confequently only five drams of pure nickel in the t^. o cru- Thedenfe ac- cibles. I reduced to powder in an iron mortar the remaining pompanying mafs (which could not properly be called fcoriae), and fepa- matter was then \ , « , . , pulverized and rated from it by the tieve and the magnet, the particles of the nickel fepa- nickel which it might contain, which produced near two and magnet and by a na^ drams more; and that nothing might be loft, I treated nitric acid. the powder with nitric acid, which attacked it vigoroufly at plTeTfo^mafs1116 firft> and Save a button of nickel, but after that did not gave no more act on it in the leaft, fo that the powder was but little dimi- regulus. niftied in weight: in expofing this matter to reduction per fe, it produced no regulus, but merely agglutinated its parts. Themafsbeing Having again pulverized the mafs, which weighed almoft again powdered £t ounces> j mixe(] vvith it one ounce of charcoal in powder, was urged with ~ , . r .... charcoal, and ancl expofed to the nre of a porcelain furnace during eighteen afforded more hours, in a crucible clofed with a luted cover, in a part of weight of metal *ne furnace which feemed to me to have moll heat. After in one mafs. having broken the crucible, which was in a found ftate, I found, under a fcoria of a deep blackiuVbrown colour, a well fufed button of metal which weighed two ounces and three quarters : it was not at all connected with the adjoining parts of the fcoria, and had at its inferior part a particular fhape, which was caufed by cavitios which were not produced by the crucible. It was fteel co- This metal had the grey colour of fleel, inclining a little to lour, rather red : it prefented in its fracture a grain not very fine : it was malieabJe^ mag- ralner nard : could be extended a little under the hammer in fical, &c. a cold ftate: heated to rednefs it endured little the ftrokes of the hammer : it was attracted by the magnet, but not fo ftrongly as either iron or nickel : it had many properties com- mon to nickel, but it was diftinguifhed from it entirely by others. As many of thefe properties were fuch, that thofe not NEW METAL NICKELINE. 263 Hot well acquainted with nickel in its perfectly pure ftate might take it for that metal, I have called it Nickeline (Nic- Name Nickelm, colanum.) The nickeline was free from all the metals which are Yound in the cobalt ores, except a little copper. The fpecific gravity of caft nickeline, which enters more Specific gravity ••• . ,--..,.. , /• r j -l 8>6* Nitric acid readily into fufion than nickel, is 8,55 ; and oi forged nicke- dhTalves it* line 8,60. On putting it into nitric acid and heating it, it is attacked more quickly than nickel : I remember having obferved an equally violent adion of nitric acid on nickel reduced by charcoal, which I then confidered as pure, ancj which I diflblved in order to precipitate from it by potalh an oxide, which I might reduce per fe. The folution of the nickeline went on well; being come to the point of faturation, it had a black ifli-green colour, and aflumed a gelatinous confidence. I employed my firft care to feparale from it a part of the Separation by iron which I thought it contained, and left it to dry a little ac|d. Refidue over a fpirit lamp : the mafs became continually of a deeper * black powder. green, and in approaching to drynefs it gave out much red vapours, and the refidue became of a blackilh grey ; I added drilled water to it, which diflblved but little of it, and that which was diflblved was an infignificant quantity of nickel. I poured muriatic acid on the blackiQi powder well waflied, So,uble .m mu- * ' ' riatic acid, which gave a green folution, in difengaging a itrong odour Green folution j of oxigenated muriatic acid. which when , rWL '.' • r i ' '• ii i • • r i . 'dried gave a red- Ihe muriatic iolutipn was, as well as the nitric lolution, of difh mafs that a deep blackifli grafs-green colour: being evaporated to dry- turns 6reen ty nefs, it produced a reddifli mafs, which became green in a moill air, and which communicated the green colour to water in which it was diflblved. This dark-coloured oxide of nickeline was infoluble in nitric Da^k?xJde °* acid, and in fulphuric acid ; but if fugar or alcohol was added, fduble in nitric the folution took place with facility at the boiling point. or lulphuric The fulphate of nickeline, being combined with water, is combuftible alfo of a blackifli green ; but it aflumes a pale red colour on matter, bei rig deprived of the water. Jjj*" of nic* If carbonate of potafli be added to the preceding folutions Precipitate by of kickeline, it occafions a precipitate of blue carbonate of carb°naI;e of - ..... potam j nickeline, inclining a little (o grey and green, and or a pale tint ; Thjs combination is very light and foft, and ditTolves in, the l264< NEW METAL NICKELINE. the acids with a flrong eftervefcence. I remember to have had, fome years ago, this precipitate of a bad colour, and not then to have examined it, considering it as a mixture of iron; nickel, and arfenic, (which lad continually made itfelf noticed by its odour of garlic) : But at laft I fufpecled its I i nature. bv caufticpot- If the folution of nickeline is decompofed by eauftic potafh, ' it gives a precipitate which refembles in its colour carbonate of chrome j that is to fay, it is of a deep greenifli-blue, which does not change when it is warned : being dried with a gentle heat, it aftumes a pale colour, which becomes deeper when it is moiitened with v* iter. by ammonia* If any of the foregoing folutions of nickeline is mixed with ammonia to excefs, the liquor alTumes a pomegranate red co- lour, and remains transparent ; which proves that it does not contain any iron, beaufe that this latter is not foluble in ammonia. By candle-light this folution is with difficulty dif- tinguifhed from that of perfectly pure nickel ; but by day- light, this latter is of an amethyft red colour, as I have elfe- where remarked. Points of com- I (hall now compare the principal properties in which nic- f*3 keline refembles altogether, or in part, nickel or cobalt, and nickeline and » ' * ' nickel or cobalt, thofe in which it is diftinct from them. It refembles cobalt — Rcfcmbhnces of '- By *ts property of fuper-faturating itfelf with oxigen at nickeiine and the expence of the nitric acid, and thus forming a body which refembles the black oxide of manganefe with regard to its folubility in the acids: 2. By its property of not being re- ducible but by the intervention of a combuitible body. It differs from cobalt — Differences be- 1. By the blackifli-green colour of its folutions, even when ande'coba^elmC they are emire,v neutralized. It is known that the neutral folutions of cobalt in the fulphuric, nitric, and muriatic acids, are of a crimfon-red colour; and that the muriate of cobalt alone becomes of a greenifli-blue on being deprived of its water : from whence it happens that an excefs of acid pro- duces this colour, becaufe it combines with the water : With the muriate of nickeline precifely the reverfe takes place; when m xed with water it is green (although of a lefs beau- tiful coJbuY than the cobalt without water), and when de- prived of its water it becornes reddifh. — 2. By the colour of its HEW METAL NICKELINE. £55 its carbonate : that of cobalt is of a beautiful poppy-blue, but the carbonate of nickeline is a bluifh-green inclining to a pale grey. — 3. By the colour of its oxide precipitated without car- bonic acid : that of cobalt is of a deep blue, and changes on warning to a blackifh-brown ; but this oxide of nickeline is of a greeni(h-bJue, and its colour does not change. Nickeline refembles nickel — I. By its ftrong magnetic quality ; although this is not fo Refemblances great as that of nickel. — 2. By its malleability, which how- line and ™ci{^ ever is lefs than that of nickel. — 3. By the deep green of its folutions; although this colour is not fo beautiful as that of the folutions of nickel. — 4. By the lofs of this green colour when its neutral combinations are deprived of water. — 5. By the colour of the acid folution with an excefs of ammonia, which cannot be well perceived by candle-light. Nickeline differs very diftinftly from nickel — 1. Becaufe it cannot be reduced without a combuftible Differences t*» body added to it. — 2. Becaufe nitric acid attacks and oxidates a^Je^"i^i%c " it more eafily. Nickel is not near fo readily acted on by the nitric acid if it is not mixed with the nickeline, which almoft always happens with the magnetic nickel which is confidered to be in a ftate of purity, and which has not been reduced per ft before my difcovery. — 3. It alfo differs from nickel by the property firft mentioned of thofe in which it refembles cobalt. — U By the colour of its combinations with the acids, when deprived of water : This colour in nickel is almoft a buff (chamois), and in nickeline a reddifh, except in the nitrate of nickeline, which cannot be deprived of water with- out decompofing it. — 5. By the colour of the precipitates, men- tioned in the fecond and third articles concerning the proper- ties wherein this new metal differs from cobalt, which are in thofe of nickel of a green colour entirely different from thofe of nickeline. which latter are of a much more agreeable green, efp?~r -My thofe of the carbonate. Letter 266 •ON ROADS, litter from G. Cumberland, Ffij. on a Project for extended Roads on the Principle of the inclined Plane, To Mr. NICHOLSON. SIR, Oa. Q6, 1805. ' Wefion-fupra-Mcrc. Account of rail- j| \.BOUT ten years ago having frequent occafion to remark, and (lifter from, the miferable ftate of the roads from Staines to London during the winter feafon, I ventured to propofe (not having at that time either feen or heard of rai!-roads) a plan which I called a truck-road for the whole of that iiage, becaufe it was intended to convey all forts of goods and even carriages on trucks, going to town on one fide of the old road and re- turning by the other. communicated This plan I fent fome time after to Dr. Anderfon, with a toDf,Andwfon' drawing, for his Recreations, but by fome accident it was roif- laid and loft ; and the reward of my trouble was the fly fneers of my grave Windfor neighbours, to whom it was known, accompanied with a fort of pity for heads capable of propoting fuch eccentric inventions. Time however revenged my caufe, by (bowing them the practicability of fuch fchemes in the progrefs of the Surry undertaking. At the fame time another plan of expeditious conveyance occurred to my mind, but which I was deterred from then producing owing to the cold reception my firft contrivance met with — And as no one, as far as I can learn, hap hitherto brought forward any improvement of the kind (although fo very obvious that it might eaiily be fuggeftcd to the mind of a child who had heard of roads on inclined planes,) I take the liberty to recommend it to your patriotic publication, convinced that whatever may, at one time or other, be of fervice to man- kind, will be always fure of a favouiable reception at your hands. The plan I propofe then is this: — That all difpatches and tail. Difpatches p0ft_ietters may, wherever it is compatible with the inclina- may be rolled in \ . , ' a fpherical cafe tion of the ground, be conveyed ten or hlteen miles to and from down a long in- London by means of iron t>r wooden Jliells of a globular form, dined channel. * »• rolling Another plan by an inclined toad. Particular de- PROVINCIAL SOCIETIES, / <2$7 rolling in a cylinder of brick orfione. When clofed and locked, a due momentum being given at a proper elevation, it is eafy to iee that^ their fpeed and fecurity muft far furpafs any other mode of conveyance that we at prefent know of; and all that would be neceflary in addition to the machine would be to have proper beds of land or wool bags to blunt their projectile force at the end of their career. I (hall not at prefent enter into the difcuflion of the con- duction of the tube-road, or go to a calculation of their ex- pence; but if you think the bare hint worth publiftiing it will give me pleafure, mould the idea be approved, to go into all the minutiae of their utility in other refpecb, and the means of their ultimate accomplimment ; Being always, Sir, Your obliged humble fervant, G. C. XI. On the State of Provincial Societies for Scientific and Literary Improvement. By a Correspondent. To Mr. NICHOLSON. SIR, JOEING in the cuftom of vifiting Aberdeen, in one of my Great advantage laft tours, I inquired if there were any Antiquarian or Li- *h,at would rc- - . c i r • ■ T t i i i Mt to the town terary bociety, or bublenption Library there, and was much 0f Aberdeen furprized to find neither one nor the other; there is, I was from the efta- told, an Athaeneum, in which a good number of newfpapers, pubiiTlibra ry* and fome of the moft refpectable periodical publications, are &c. taken in, and in a room above that, a circulating library; this laft I knew to be the property of two very refpectable bookfellers in Aberdeen, and I believe the former is alfo, but the two united by no means effect the utility of either a lite- rary fociety, or a fubfeription library, in which the books, fyc, are the property of the members, and whofe concerns, fuch as choofing and ordering booksf and the like, areconducled by a com- mittee, chofen out of the fubferibers. Few of thofe who know that there is no fuch inftitution there, when they confider the j*fpe liability of the place, either in a commercial or literary , view. 26S PROVINCIAL SOCIETIES. view, but mud feel greatly aftonifhed ; and more particularly will the want appear, when it is alfo known, that in Mdntrofe, Arbroath, Dundee, and Perth, places much fmaller than Aberdeen, and not pofTefting any college eflablifhment, there are fubfcription libraries, on the above plan ; nay, that Perth hath alfo an Antiquarian Society ! Subjoined is a lift of fome other places in North Britain, .enjoying the advantages of fuch eftablifhments as I would recommend to Aberdeen ; fome of whom, it is obvious, have not near the profpecl of fuccefs that that place could command. Glafgow, Paifley, Greenock, Kilmarnock, Linlithgow, Haddington. On the borders of Northumberland, Dunfe and Kelfo, The annual fubfcription to none of theft is more, in fome cafes not fo much, as to the Athaeneum of Aberdeen and others, and they all pofTefs very excellent and increafing feleflions of books. I am, Sir, Your's refpe&fully, A TRAVELLER, York Hotel, Bridge Street, Black Friars. a«d to other re- P* S. I am forry to be informed that neither Invernefs, Banff, fpetfable and or Peterhead, pofTefs fuch inflilutions, particularly the firft, which prefents fuch an abundant number of objects to the antiquarian, and is furrounded by, and contains, fo many gentlemen of diftinguifhed liberality, and ingenuity; atthisplace thenorthern meeting was eftablifhed for the avowed purpofe o promoting intercourfe amongft difiant families, but how much more might be effected of general amelioration and comfort, by the efla- blifhment of a Literary and Antiquarian Society, iirwhich fub- jecls connected with general improvement might be difcuffed, and books in chemiftry, agriculture, and other more imme- diately ufeful parts of knowledge, collected. Notice WASTEFUL NEGLIGENCE, 2<)9 XII. Notice of certain Infiances of wafieful Negligence in fame Fiffteries in the North. % an Enquirer. To Mr. NICHOLSON. SIR, London, Oft. 10, 1805, AT is mentioned in the Statiftical Reports of Banff and Peter- Inftances of ^ head, that the fimermen there never think of carrying their fifth ^f^me" along the coafl fouthward, which they might do, to Leith, in fisheries. 24 hours, or with a good brifk wind to Berwick-upon-Tweed, or even Newcaftle-upon-Tyne : but when their refpe&ive towns are fupplied they throw the remainder upon the dunghills for manure ! this was pofitively affirmed to me as a truth, by a gentleman of great refpectability of Aberdeen. — At Arbroath another cuftom equally as extravagant in its kind prevails, and of which I have been a witnefs: the crab fifhery there is (o productive, that after boiling them, (he bodies of the crabs are thrown away, and the large claws only brought to table ! Ought not fuch amazing wafte to be remedied ? * Your's refpectfully, An ENQUIRER, XIII. On Bile. By M. Thenard/J-. -OlLE has been commonly confidered as a faponaceous liquor Bile eonfidered charged with albumen : but it has been found, upon clofer in- as a foaPwith veftigation, to prefent phenomena which cannot be accounted * $u. What may the value of manure procured from fifb atthefe plarts, compared with the price of the article at the neighbouring markets, fubject to the deduction of carriage (coaftwife), and the effect of a rival fupply from nearer parts of the coaft ? — The facts which would iblve this queftionfc would (hew whether the fifhermen neglect their interefts in thefe proceedings.— W. N. f Bulletin des Sciences, No. 95. for albumen. 270 ofo flrtt. for merely by the prefence of thefe principles : this is more particularly to be obferved on fubmitting it to the action of fire and of acid s. Deftruftive dif- Bile, if diftilled to drynefs, leaves a refiduum equal to |-th S^dJ^ln °fit8 oriSinal w^g1^; ^m 100 parts of which calcined is which is only obtained a carbonaceous matter, comprifing feveral kinds of fodafifand°fthis ^ ™ Inarine faIt» phofphate of foda, fulphate of foda, cannot faponify phofphate of lime, oxide of iron, and four parts of foda. Bile the oil. therefore contains no more than f£$ parts of its weight of foda. So final 1 a portion of alkali would not be fufficient of itfelf to dilfolve that quantity of oil which is known to exift in bile: a fair preemption may therefore be entertained that this li- quor contains fome other property to fupply the abfence of al- kali. This conjecture increafes to ftrong probability, if not to abfolute certainty, in attending to the action of acids on bile. Acid feparajtes If a kw drops of acid be mixed with bile, a liquor of a rYomtile^t'hT reddiftl tInt is opined, which ftains paper of a bright clear fluid is yellow. In this experiment little or no precipitation is per- JjJJJj ' and af~ ceived ; but on the addition of more acid, it takes place abun- arefiduum. dantly : the matter depoftted con lifts of albumen joined with a very fmall portion of oil, not at all correfpondent to the quantity of thefe fubftances to be found united in pure bile. The liquor remaining after filtration is of an extremely bitter tafte, and leaves on evaporation a refiduum equal to what is ob- tained from a like quantity of bile in its original (late. The oil with an On diflfolving the oil, which had been previoufly obtained alkali and aibu- from bile, in alkali, and adding to the lev produced, a portion ?aea is not bile. - - ° * *' , r r „ oi albumen, a combination took place which was decompofed by the mod feeble acids, and from which vinegar precipitated all" the oil. This combination, therefore, was not bile; con- fequently bile confifts not merely of albumen, oil, and foda; and this is the reafon why foluble falts, bariles, ftrontian, Time, and feveral metallic difp>lvents, make no impreffion upon bile. Bile contains a No longer doubting that there exifted in bile a matter peculiar peculiar matter, to itfelf. I endeavoured to feparate it ; and after a few trials, I fucceedcd, by me^ns of a combination of acetous acid with lead. Acetite of lead O:. pouring into bile acetile vyith a flight excefc of oxide of FdCi?b ^Vh lead ^llmt *S' aCf ite & common lead boiled with about the liquor by evap. Ctb Part °f lls ovvn weight of litharge deprived of its carbonic acid); ON BILE. 271 acid) the whole of the albumen and oil were precipitated; the gave a fubfanc* p . , i i-^ *r which whea liquor being filtered, the oxide of lead and acetite were iepa- purc rated from it by means of fulphurated hidrogen ; and by eva- poration, after having again filtered the liquor, a fubftance was obtained whofe flavour was at once faccharine and acrid, fomewhat fimilar to the juice of certain kinds of liquorice. But as this fubftance was ftill luppofed to be charged with the (alts of the bile, changed into acetite, by the acetite of lead, it was precipitated with acetite fuper-fatu rated with oxide of lead, containing one part of the quantity of acid found in com- mon lead ; tiie precipitate was diflblved in vinegar, to free it from the fulphurated hidrogen, filtered, and again evaporated ; by which means the matter was obtained in its greateft purity. Its principal qualities are : had the pecullar 1. Being folubie in water, and in alcohol, flightly deli- enumerated, quefcent. 2. It is not precipitated by acetite of common lead ; but is entirely fo by the faturated acetite of lead, which precipitate is folubie in acetite of foda. 3. It will not ferment with yeaft; will give no ammonia by diftillation ; and is not affected by the prefence of nut- gall. 4. It diflblves the oily matter of bile : but to facilitate this operation, it is necefiary to diflblve the two matters together in alcohol, evaporate, and warn, the refiduum in water. One part of the faccharine and acrid fubftance diflblves only three- fourths of the oily matter. Now, as thefe matters are nearly in equal proportions in bile itfelf, it mull be admitted that i foda contributes towards the complete diifolution of the oil; neverthelefs acids fcarcely, if at all, affect it. In reflecting on the above experiment and its refults, I con- Bile confifts of* eluded that bile was a triple compound of a little foda and ^Jj^f* aanndd much oily and faccharine matter; that acids decompofed it faccharine mat- but in part ; in other words, that it was capable of containing ter» *c% an excefs of acid without having its portion of foda neutralized. I therefore calcined bile that had been acidulated with fuJ- phuric, muriatic, and other acids, and found in each cafe the foda left in the calx : it is therefore very probable that the fac- charine matter, in conjunction with the oil, decompofed a certain quantity of marine fait, and deftroyed the power of the acid. It 272 ON BILE- Determination of component parts or bile. Analy/is. It would have been of little fervice to defcribe the con ft h tuent parts of bile, had their proportions been left unafcerlained; I have therefore endeavoured to determine them in the follow- ing anal)fis : By means of nitric acid, 1 feparated the animal fubflance, which is fuppofed to be albumen, with a very fmall portion of oil : this being foluble in alcohol and the other not, it was eafy to afcertain the weight of each. I then precipitated all the oily matter, with acetite and a fmall excefs of oxide of lead : this precipitate being mixed with the metallic oxide, I diflblved it in weak nitric acid ; after filtering the liquor, I deprived it of the lead which remained, by means of fulphurated hy- drogen; and by evaporation, I obtained the peculiar fubftance, mixed, indeed with the falts of the bile, which had moftly undergone a change by the acetite of lead, and whofe weight had noted. I afcertained the quantity of foda by calcining 100 parts ex- tracted from bile, and comparing with much care how much the refiduura would imbibe of acid at 16°, with the quantity imbibed by pure foda. I alfo, by means not necedary to ftate here, obtained the quantity of each of the other falts con- tained in bile ; from all which experiments, made with the utmoft care, I conclude that 800 parts of the bile of an ox contain — Numerical re» Water 700 Parts fult. Oily matter - . - - 43 Particular fubftance - 41 Animal fubftance - 4 Soda 4 Marine fait - 3.2 Sulphate of foda O.S Phofphate of foda - 2 Phofphate of lime - 1.2 Oxide of iron - - 0.5 799.7 N. D. This calculation is T\ deficient of the given quantify. Bile forms an interefting fubjeel for a number of other re- fearches : the varieties to be found in the feveral fpecies of animals, and which a multitude of circumftances, particularly a morbid affection of the organ which fecretes it, may modify ; 5 tM m CHINESE FIRE-WOR&S* the calculi which are there formed, and are of a pceuliar na- ture ; {he oleaginous and animal fubftances ; and that parti- cular matter, differing from all others hitherto known; wilt not fail to excite a lively intereft, and are the fubject of feveral other Papers which I purpofe fliortly to bring before the public. XIV. Quotation from Sir G eoroe Staunton's Einbajfy, containing a Defcription of Fire Works unknown in Europe. Propofed by a Correjpondent with a View to obtain Explanation of the Means by which they were produced. To Mr. NICHOLSON. SIR, J- prefume to think it will accord with the general aim of your Introduction* excellent collection to infert the following quotation ; and t indulge the hope that your compliance with my requeft for that purpofe may produce an explanation from fome of your ingenious correfpondents. I am Sir, Your conftant reader, P. M. After the ballets, Fire- works were played off; and even Remarkable fire- works of the Chuiefo, in the day-time had a ftriking effect. Some of the contrivances fiiewori were new to the Englifh fpeelators. Out of a large box, among other inffgnces, lifted up to a confiderable height, and the bottom falling out as if it were by accident, came down a multitude of paper lanterns, folded flat as they iffued from the box, but unfolding themfelves from one another by degrees. As each lantern affumed a regular form, a light was fuddenly perceived of a beautifully coloured flame, burning brightly Within it; leaving doubtful by what delufion of the fight thofe lanterns appeared, or by what property of combuftible mate- rials they became thus lighted, without any communication from the outride to produce the flame within. This devolution and developement were feveral times repeated, with a difference Vol. XII — December, 1805. T of 274 0N "CARBONATE OV rOTASlf. of/igure every time, as well as of the colours, with which the? Chinefe feem to have the art of clothing fire at pleafure. On each fide of the large box, was a correfpondence of fmaller boxes, which opened in like manner, and let down a kind of net work of fire, with drvifions of various forms, which (hone like burnifhed copper, and flathed like lightning at every im- pulfe of the wind. The whole ended with a volcano, or eruption of artificial fire, in the grandeft ftile." — See Staunton's Bmbajfy to China, Volume III, page 73. XV. On the Carbonate of Potajh. By M. Stein ac her *. Carbonate of « water, cryftallizes too quick, and before the precipitation of the file*. 4. The dofes of alkali and water moft favourable to a regu- lar cryftallization, at the temperature of from 5 to 10 above O pf Reaumur, are one part of diftilled water, and half a part of purified potato. If the refults of my experiments {hall improve the prepara- tion of carbonate of potafh, and if the difpofition of my appa- ratus prevents the neceffity of continually watching its direc- tion, by procuring without trouble that gentle and continued preflure, of which Pelletier perceived the efficacy for thefatu^ ration of the alkali, I have reafbn to think that the true friends of chemiftry, I mean thofe who pra&ife it, will confider m^ pbfervations with indulgence. tea ■ ■,■" .'.,■' ',, "■ .::,. , ,, ,..•.' ,\. &..J,, ■,. .,:&. XVI. Method of preparing a luminous Bottle, which long prefcrves its Effect* A luminous IT is eafy to prepare a bottle which fiiall give fufficient light bottle. # Put 3 during the night to admit of the hour being eafily feen on the phofphorus in a clial of a watch, as well as other objects, by the following. i°n?tPbailin 'ST mCanS' The fluid will A phial of clear white glafs, of a long form, fljould be give light in the chofen, and fome fine olive oil fliould be heated to ebullition whenever the m another veflel : A bit of phofphorus, of the fize of a pea, coik is pulled mould be thrown into the phial, and the boiling oil mould then be carefully poured over it, till the phial is one-third filled : The phial mould then be carefully corked; and, when it is to be ufed, it mould be unftopped, to admit the external air, and clofed again : The empty fpace of the phial will then appear luminous, and give as much light as a dull ordi- nary lamp. Each time that the light difappears, on removing the ftopper it will inftanlly re-appear. It is proper to ob» ferve, that in cold weather it will be necefTary to warm the bottle for a little while in the hands before the fropper is re- moved, without which precaution it would not yield any light, * Sonini's Journal, A phial XAGNESIAN EARTH. 277 A phial thus prepared may be ufed every night for fix months: there is no danger of fire from it, and its coft is very fmall. • XVII. Jnalyfis of the Magnejian Earth of Baudiffero in Canavais (in the Department of the Loire,) known by the Name of Porcelain Earth, and hitherto confidered as a Clay, By M. Giobert.* JL HE earth of Baudiffero, known by the name of porcelaih Porcelain earth earth, has been hitherto confidered as one of the pureft ar^il- co°fiderfd *! t " native alumine. iaceous earths known in the hiftory of foflils, and is arranged in our cabinets of minerals as native alumine. In a manufacture of ftone-ware pottery, which has been ufed as fucfc ia eftablifhed at Vineuf, this earth has been ufed for a long time, the ft°ne-ware *s a clay of extraordinary purity. The celebrated Macquer, neuf. and with him Baume, to whom fpecimens of this earth were fent from the above manufacture, pronounces poiitively that it Various chemift* was a clay of fuperior quality to that which they ufed in the ^^{j* fam* manufactory of porcelain at Sevres. Doctor Gioanetti continued to ufe it in the manufacture of fcis fine porcelain at the fame Vineuf; and he engaged in, if not ananalyfis, at leaft fome experiments on this earth, to at- certain raore precifely the proportions in it between (ilex and earth, which he believed to be pure alumen. Thefe experi- ments convinced Doctor Gioanetti, that, with the exception of a little carbonic acid which he found in it, the earth of Baudiffero was an alumen almoft perfectly pure, or at leaft the pureft that he had ever met with. This chemift, when I made enquiries of him relative to The alumine this earth, allured me frequently, that picked pieces yielded J£s * ~JJJ* him fometimes ninety per cent, of alumen, including a little carbonic acid, and that in the grofs it yielded conftantly at leaft 80. - On the perufal of the mineralogical defcfiption of the moun- Other authorl- tains of Canayvais by the Chevalier Napion, it will be found **• ihat this eftimable mineralogift has not hefitated to declare the * Journal de Phyfique, LX» earth. 278 MAGNESJAN EARTH. earth of Baudiflero to be the moft pure alumen ever found in piedmont; and again in his elements of mineralogy, he men- tions the earth of Baudiflero as native alumen. Contrary to thefc ^acls f° pofitively aflerted by fcientific men fo eftimable as afTertions this Maqucr, Baiime, and our colleagues Gioanetti and Napfon, taTnsnValur^ne a^ra»tted no doubt of the nature of this earth; to which au- at all. thorities might be added the fuccefs with which Gioanetti con- ftantly ufed"it in his porcelain manufacture. Amorig a number of refearches which I made relative to the artificial fabrication of fulpbate of alumen, I employed myfelf on this earth, and to my great furprize found that the earth gf Baudiflero not only was not pure alumen, but did not even contain an atom of it. I enfe ua*. Tne -0,vn °f ^audilfero isfifuated atleaft three leagues from tities of fulphu- Ivree and from ^rozo, this laft village, as celebrated for it* ret of iron at jron mines as for the manner in which they are 'wrought, con- Baudiffcro. . . . *' 1 . , n., . tains in a mountain, among other minerals, an inexhaunible mafs of fulphuret of iron of a remarkable purity, whefe there is eftablifhed a manufacture of fulphale of iron by the com- buftion of the fulphur. Efflorefcenccof Qn infpecling this manufacture Iaft year, I was (truck with the nefghbouring the Angularly powerful action, which the fplphureOus acid, by fulphureous f°rmed by tne combuftion of the fulphur, (and of which a part vapours. ■■ expanded itfelf to neighbouring places,) exercifed on the great blocks of (tone. Thefe ftones were a fort of granite fchiftus ; and the (uU phureous acid attacked them fo forcibly that it made them ex* foliate, and at laft reduced them to a fpecies of efflorefcence, or white powder evidently faline, in which its affringent tafte announced fulphate of alumen. Probability that This circumftance made me think that if a good argil was fulphate oi alu- expofedto thea&ion of the acid it would be alumcnated ; and Sght'teadJan- the earth °* Baudiflero, which I believed to be almoft pure tageoufly made alumen, being at fuch an inconfiderable diftance, made me from the porce- concejve the hope of being able to eftablifh with economy at Piedmont, a manufacture of artificial fulphate of alumen. V^y promifmg The idea of this eftabliihment appeared to me to befo much JocaJ advantages. tne more fortunate' as there was at the foot of the fame moun- tain which contained the pyrites, a great turbary, which ex- tended almoft as far as Chinfella, that is to lay, almoft to Baudiflero, and which might furnifh fuel at a very fmall ex, J ' ■ • penfej MACNfcSiAN EARTH. j 279 penfe; and it Teemed to me that nature, in placing at one fide an inexhauftible mine of fulphur, and at the other inexhautf- ible mafles of the proper earth of ?n extremely rare purity, and between them an abundant fupply of fuel, of the fort moil proper for this kind of work, had done its utmpft in fa- vour of the eftablifliment I intended. There only remained to make fome experiments with a view Experiments to afcertain the moll profitable way of proceeding ; and to preparatory. examine principally if the iron which is united to the fulpbur in the pyrites, would not be injurious to the fulphate of alu- - men obtained, » With this defign I began by examining the action of the earth of Baudiflero on the fulphate of iron, and the quantity of the earth neceflary for the decompofi tion of a given weight of ful- phur. In the different experiments the fulphate of iron diflblved The earth of in water, and boiled with this earth indifferent proportions ^^^fX became evidently decompofed after boiling for lefs than a quar- phate of iron in ter of an hour ; the iron was precipitated of a blackifli grey, the numid way. ,..,*,. \'%r * -i , • 'A little potafh while the lolution was colourlels, and ammonia dropped into was added and it formed only a very white precipitate, which did not an-t*ielWuor.fet nounce much iron ; I filtered the liquor, of which one part was mixed with a little potato* and placed fo as to cryftalize ; and to afcertain whether there was any potafh in the earth of JJaudiflero, I fet another part to cryftalize without any alkali. I ohferved that the liquors cryftallized immediately after be- jt gaVe fulphate coming cold; but in the place of octahedrons, I found the °* 'magnefia and mod perfect, the mod beautiful, and pureft cryfials of fulphate"0 a um* of magnefia. *JThe liquor which remained produced, on a new evapora- All the cryftals tion, the fame pure cryftals of fulphate of magnefia; and ™.er<: of ^ i- j . r re- • . n i- kind,- and hence did the lame on (uccefiive evaporations and cry (taiizat ions to magnefia is an the laft drop of the liquor, Jn this manner was a natural alu- e*cel3ent porep* men transformed entirely into magnefia, and at the fame in- ttant magnefia became at once an excellent porcelain earth. \f examples of this kind fhould multiply, the necefiity of che- mical analyu^s for the knowledge qf fpffils will become more ^nd more manifeft, and lefs reliance will be learned to be placed on their external and phyfical characters, w|)ich at p?$» ipnt feem§ to me to be too much abufed. J 280 MAGNESIAN EARTH. More careful The above unexposed refults engaged me to make a more the naSvewrUu careful examination of the earth of Baudifiero, and Which is the objeft of this memoir. At the lime when I found that the fuppofed alumen of Bau- difiero in Canavais, was really a magnefian earth, I knew of no other example of an earth truly magnefmn, but fehsfc of the earth of Salinelle, or of Sommieres, which Berard bid made known (Annulcs de Chimie, Tome XXX IX. p. 65,) Othw fpccimen* In this magnefian earth there is no mixture of any other nefia.UV6 ""^ eart^ excePfc fi!ex» and tliat- W a very .fmall proportion, of which fact there are but few examples. But on receiving the twelfth volume of Brochanl's Mineralogy, 1 found that the difcovery of a magnefian earth was announced in it, which is the native carbonate of magnefia found by Doctor Milchel at Roubfchitz in Moravia. From the analyfis which he made of if, and which is mentioned by Broehant, we are afiufed that the native carbonate of magnefia of Moravia is compofed only j of magnefia and carbonic acid in almoft equal parts; but the yellowilh grey colour fpolted with black, which Doctor Mit- chel gives to this earth, teems fufficiently to indicate the ex- igence of fome other conftiluent parts. On comparing the characters and nature of the magnefian earth of Baudifiero, it will be eafy to perceive the differences which diftinguim it from the other preceding magnefian earths. Local fituation of The magnefian earth of Baudifiero is found difpo fed in a the earth of ve;n jn a fteatite rock, of which the mountain is compofed that enclofes it. It is accompanied by an horn-frone, fome- times of a tranfparent pale colour, fometimes, when its de- compofition commences, of a white almoft opaque. In this ftate the horn-flone does not appear to be that of which Doctor Bonvoifin has given the defcription and analyfis, under the name of the Hydrophane of Piedmont. It is found in Our magnefian earth appears in mafies, fometimes in round- maffes, lumps, [fa lumps (mamelonnes) and fometimes in fragments more or " pr rasraents* lefs large'; the lumps and fragments are fometimes, but rarely, tuberculofe. Beautifully This earth is of the moil beautiful white, in which it differs yrhite. from that of Moravia, of which the colour is a yellowifli grey fpotted with black, and from that of Salinelle, or of Sommi- eres, which is of a chocolate colour, The lMf« Magnestan earth. 281 The hardnefs of this earth is variable, fometimes it is foft, Soft* or hard ft irt which ftale I (hall call it the earthy fort, and forne pieces of ^ra^ftecl. it have a confiderable hardnefs; as in all my experiments I % tried them comparatively, I (hall name this laft variety the ftomj kind, to diftinguifh it from the preceding. T! -e ftony variety is fcratched by ft eel, fometimes, on the contrary, it is hard enough to fcratch fteel. It can be eafily Pulverable, tha* reduced 10 powder; but with much difficulty to very fine pow- ranenTia the^ der, and this only takes place after long trituration in a mortar air. of porphyry. Its hardnefs neither increafes nor diminilhes by the action of the air; in this refpecl it differs from the magne- fia of Moravia, which is very friable, and from that of Sali- nelie, which is foft in its bed, and only grows hard on exfic- cation in the air. The fracture of this variety is conchoidal and unequal. Fraaure con- Its furface is dull ; fometimes, but Very rarely, fhining fpots p°j, ao* ke appear. It is conftanily perfectly opaque, and moderately moderately heavy; its fpecific gravity is variable. heavy. It is a little unctuous to the touch in the friable and earthy Slightly und*tu- fort, and but very little fo in the (tony variety. «us a»d *dhe- It fenfibly adheres to the tongue, though not much; it ac- quires this property in a considerable degree when it is mo- derately warmed at the fire. Plunged in water, the ftony variety does not abforb it at all ; The foftfped- the friable fort abforbs it greedily, and with an 'biffing, but themensabf?rb. & ' ' ° water and nux mixture does not grow hot. like clay. The friable fpecies mixes with water to a confiderable de- gree, in the fame manner as clay ; the fine particles of this earth, like thofe of clay, continue a long lime fufpended in water, with this difference from thofe of clay, that they do • ' not unite together. Urged by the blow-pipe, on a cianiteAre notfufible cryftal, it is infufible. by the blow. Treated in a mafs, on the fire in a crucible, efpecially in aP red hot crucible, it foon decrepitates, and divides into thick fcaly pieces, which leap out of the crucible; this does not happen if it is heated by degrees and moderately. If it is reduced to a fine powder, and then traited on the But apparently fire, as foon as the bottom of the crucible begins to grow red fo in a crucible. hot, this earth boils for a fhort time, and feems to unite toge- ihiT, as if moderately moiftened, A* 282 MAGNESIAN EARTH. With lofs of one An hundred parts of this earth treated in this manner, until the boiling ceafes, after an hour of incondefcence, became re* duced to 85, and 0,40.. The earth calcined in this manner throws out that blueifh light which has been obferved from common magnefia. Giving out car- If the calcination is made in a retort of earthen ware, to Jxmic acid. which a (yphon is adapted, and plunged into a bottle 61Ied with lime water, there is formed in the bottle carbonate of lime; fo that the diminution of weight is partly due to thedii* engagement of carbonic acid. & contains a A thoufand grains of this earth in fine powder were boiled S'fulDhlteof^ ]U flX Pounds of diftilfed water. The liquor being filtered, lime. * ?nti then eifayed by various reagents, prefented the following refulK With the folutions of the acetate, nitrate, and muriate of barytes, the mixture became troubled almoft inflantly, and formed a fediment of fulphate of barytes, but in a very fmall quantity, The oxalate of ammonia formed oxalate of lime with it, but alfo in a very fmall portion. Thefe experiments repeated different times, on the earth, fcotji of the ftony and friable varieties, conftantly gave thq fame refults. {Jme and fulphuric acid, or fulphate of lime, is therefore, although in a fmall degree, a conftituent part of the earth o£ Baudiflero both in the ftony and Toft ftate. A minute por* The nitrate of filver formed a precipitate equally with both tion of muriatic forts; but remarkable differences were obferved between its m&ntfnthe* *&&* in the vyaler ftom th^ ft°n? ^Pecies'- and on ihdt irom ftony variety, the foft variety ; with the latter it formed a precipitate, which collected in a powder at the bottom of the gl^fs ; but with the water from the ftony kind, betides the precipitate, 6Ia-? ments were produced conftantjy, which indicated the prefence of muriatic acid. Many times the " fuiphuric acid*" wa$ flrft removed by the acetate of barytes, and after filtration, or* being treated with the nitrate of filver, (till formed a precipe tate of muriate of filver. * It is not clear what the removal of the fulp/iuric acidmenUor\ei\ here had to do with making the appearance of the muriate of filver fecm extraordinary ; perhaps it is an error iathe original ; the trah-& l6t&n is literal and correct. B. 3 Th* MAGNESIAN EARTH. $8$ The infufion of the ftony fort afforded differences from the other, with ammonia alfo; this reagent did not ever trouble the infufion of the friable fpecies, but always troubled, though /lightly, the infufion of the ftony variety. It follows from thefe obfervations that, befides the fulphate of lime which both kinds of the earth of Baudiffero contained, the ftony variety held in union muriatic acid, perhaps in com- bination, partly with the lime, which there was not furficient fulphuric acid to faturate, and partly united to another earth, which was not lime, fince its folulion permitted itfelf to be decompofed by ammonia; and it will appear that this earth ^ was magnefia. The fulphuric, nitric, and muriatic acids attack this earth, The ancient mU when it is well divided into an extremely fine powder. "Yk ^ $n^t{y9 Their action however is but little apparent, but on the leaft earth, addition of heat it becomes ftrongly marked. Very fmall bub- bles of gas, which rife from the bottom of the liquor, a flight white fcurh which forms itfelf at the furface, and a fmall hiflZ. jng, (hews plainly that there is a difengagement of an aeri, form fluid or effervefcence. When the earth has been previoufly calcined in the fire, With great f$xe their action is very different. There is not, as may be fore- % P a telefcoPe ... can determine chiefly to ufe a ten -feet reflector, it appeared to be a defidera- the figure of an 4um highly worthy of investigation to determine how fmall aobiec^ diameter of an object might be feen by this inftrument. It is known that a very thin line may be perceived, and that objects may be feen when they fubtend a very fmall angle ; but the Cafe he wanted to determine related to a vifible dilk ; a round, well defined appearance, which might without hefitation be affirmed to be circular, if not fpherical. In April of the year 1774, the Doctor determined a iimilar The author's queflion relating to the natural eye : and found that a fquare unaffifte {11.} Many 288 Magnitude of small celestial bodies^ Other caufes (II.) Many o(her caufes will have an influence on the ap^ customers?" parent dIameler of tlie furious difks of the ftars, fuch as the goodnefs of the fpecula and lenfes ; but they are fo far within the reach of our knowledge, that with a proper regard to them, the conclusion he has drawn in Rem. (2.) " that un- der the fame circum fiances their dimenfions are permanent," will (till remain good. Similar experiments were made on the fpurious diameters of terreftrial objects, namely filver globules, which afforded the following remits : Spurious ditks (I.) The terreftrial fpurious diflcs of globules are his than of globules are the real difi whereas we have feen, in Remark (1.) of fmalJer than the , ' . *", ' , \ ' real difks. the celeftial fpurious di&s, that thefe are larger than the real ones.* Larger magni- (2) The lefs globule has the Iargeft fpurious difk. This tudes ; give larger agrees with the fpurious difks of celeftial objects : the ftars of *' ' ** the flrft, fecond, and third magnitude, having a larger fpurious difk than thofe that are of inferior magnitudes, coloured like the (3.) With refpecl to colours, the terreftrial alfo agree with celeftial » tne celeftial fpurious diiks. Lefs with ("M The. fpurious diameters of the globules, like Ihe fpu- greater mag. rious difks of the ftars, are proportionally lefTened by in- powerj creating the magnifying power, and increafed when the power is lowered. But not propor- (^*) When the eftimations are compared with the powers> tiooally. it will aHb be feen that the increafe and decreafe of the fpu- rious diiks of the globules is not inverfely as the powers, but in a much lefs ratio. Power afts (°*-) The effect of magnifying power is unequally exerted more on fmall on fpurious diameters; and that, as with celeftial objects, fo difks, Wlt^ terreftrial, this power a6ts more on the fmall fpuriou* ditks than on the large ones, and diminution (70 The fpurious terreftrial ditks alfo refemble thofe of the; of apertwre i ftars, by increaiing when the aperture is lefiened, and de- creafing when it is enlarged, greater on fmaH (8.) By thefe experiments it is proved, that the increafe **&*• and decreafe of the diameters occafioned by different aper- tures is not proportional to the diameters of the fpurious dilks. * It appears from the context, that this arifes from the terref- trial fpurious difks being formed by the fmall fpot of reffe&ed light from the metallic globule, am! not from its whole diameter. Planet juno. 289 (9.) But that the change of the apertures a£ls more on the fmall, and lefs on the large ones. (10.) The fpurious difks of globules are lofl for want of Thefe difks art proper illumination, but do not change their magnitude on J^j^^J/ that account. The brightnefs of the atmofphere in a fine day light. is fufficient to produce them ; though the illumination of the fun is generally the principal caufe of them. (II.) The diameters of fpurious difks are liable to change from various caufes; an alteration in the direction of the illu- mination will make the reflection come from a different part of the globule, which can hardly be expected to be equally po- lifhed in its furface, or of equal convexity every where, being very feldom perfectly fpherical ; but as upon the whole the figure of them is pretty regular, the apparent diameter of the fpurious difks will generally return to. its former iize. Globules of mercury were ufed inftead of thofe of filver, and Mercurial glo- with the fame refults. bules- The fpurious terfeftrial diffcs were then meafured by com- Mcafurement of paring them with circles on a tablet : and it was found that a ^g0^^ variation in their illumination did not affect their magnitude, diftinguiflied It was alfo found that the rays from the central part of the fr<>m real difks . . , J , r r . r by ufing firft a mirror gave a larger image than thole from its circumference, central, and So that when a central aperture of three inches gave an image then an annular correfponding with a circle of 0.465 inch, an annular opening g^ eu,[fa'rges a,^ from 6.5 to 8.8 inches gave only 0.1 S inch for the image : and thefecond di- the experiments werefufftciently varied as to the magnitudes mim 5S c enJ* and fituations of the apertures to fhew that this difference did cot arife from more or lefs light. This property of the mirror ferves admirably to diftinguifh a Trials. fpurious difk from a real one ; and proved to be fo on trial with terreftriat and celellial objecls. Obfervations on ike Nature and Magnitude of Mr, Harding's lately difcovered Star. On the day Dr. JH[erfchel received an account of Mr! Obfervations oft Harding's new ftar, which was the 24th of September, he ±c &*Mt Jun0i directed his telefcope to the calculated place of the new object, and noted all the fmall ftars within a limited compafs about it. They were then examined with a diftin£l high mag- nifying power ; and fmce no difference in their appearance Vox, XII.— Decemeer, 1805. XI was 290 PLANET SVHOi Obfervationc on was perceivable, it became necefTary to attend to the change* th« planet Juno. that m;ght happen in the fituation of any one of them. They were delineated as in Fig. 1 , (Plate XIV.) which is a mere eye- draught, to ferve as an elucidation to a defcription given with it in the journal; and the flar marked k, was the new object. Sept, 29. Being "the firfl clear night, he began a regular feries of obfervations: and as the power of determining fmall angles, and diflinctnefs in mowing minute difks, whether fpurious or real, of the inflrument he ufed on this occafion, had been fuffi- ciently invefiigated by the foregoing experiments, there could be no difficulty in the obfervation, with refources that were then fo well underflood, and have now been fo fully afcer- tained. '* Mr. Harding's new celeflial body precedes the very fmall liar in Fig. 3, between 29 and 33 Pifcium, and is a little larger than that flar ; it is marked A. fg h are taken from Fig. 1. I fuppofe g to be of about the 9Lh magnitude, fo that the new flar may be called a fmall one of the 8th." With his ten-feet reflector, power 496.3, he viewed it atten- tively, and comparing it with g and h, Fig. 3, could fund no difference in the appearance but what might be owing to its being a larger flar. By way of putting this to a trial, he changed the power to 879,4, but could not find that it magnified the new one more than it did the flars g and h. " I cannot perceive any difk ; its apparent magnitude with this power is greater than that of the flar g, and alfo a very little greater than that of h ; but in the finder, and the night- glafs g is confiderably fmaller than the new flar, and h is alfo a very little fmaller." , . He compared it now with a flar which in the finder appeared to be a very little larger; and in the telefcope with 879,4 the ., apparent magnitude of this flar was alfo larger than that of the new one. " As far as I can judge without feeing the afteroids of Mr. Piazzi and Dr. Gibers at the fame time with Mr. Harding's, ihe lafl miift be at leaf! as fmall as the fmallefl of the former, vvhieh'is that of Dr. Olbers." " The flar k, Fig. 1 , obferved Sept. 24, is wanting", and was therefore the object I was in fearch of, which by computation mufl have been that day in the place where I faw it." 3 "Th laANET JUNQ, *' The new ftar being, now in the meridian with all thofe Obfcrvatlons on to wliich I am comparing it, and the air at this altitude the planet Juno, being very clear, I ftill find appearances as before defcribed : the new object cannot be diftinguifhed from, the ftars by magnifying power, fo that this celeftial body is a true af- teroid." . Mr. Bode's liars 19, 25 and 27 Ceti are marked 7m, and by Comparing the afteroid, called Juno, withthefe ftars, it has the appearance of a fmall one of the 8th magnitude. With regard to the diameter of Juno, the author remarks that had it been half a fecond, he muft have inftantly per- ceived a vifible difk. Such a diameter, when he faw it magni- fied 879,4 times, would have appeared under an angle of 7' 19^,7, one half of which, it will be allowed, from the ex- periments that have been detailed, could not have efcaped his notice. . Oct. 1. Between flying clouds, the afteroid was feen, which in its true ftarry form has left the place where it was feen Sept. 29. It has taken the path in which by calculation it was ex- peeled to move. This afcertains that no miftake in the ftar was made when laft obferved. Oft 2, 7h. Mr. Harding's afteroid is again removed, but is too low for high powers. 8* 30'.. Viewed it now wiih 220,3 288,4 410,5 496,3 and £79,4. No other di(k was vifible than that fpurious one which fuch fmall ftars have, and which is not proportionally mag- nified by power, With 288,4, the afteroid had a larger fpurious diik than a ftar which was a little lefs bright, and a .f mailer fpurious iliik than another ftar that was a little more bright. Oct 5, with 410,5. Thefituation of the. afteroid is now as in Fig. 4. Its diik* which is probably the fpurious appearance of ftars of that magnitude, was compared with a larger, an equal, and a fmaller ftar. It was lefs than the fpurious dilk of the larger, equal to that of the equal, and larger than that of the frnaller ftar. The gradual difference between the three flars is exceedingly fmall. " With 496,3, and the air uncommonly pure and calm, I fee fo well that I am certain the di(k, if it be not a fpurious one, is lefs than one of the fmalleft globules I faw this morning in the tree/' U2 The %92 ' PLACET JUNO, ScfefaatI°n8 °A The clIameter of tIlIs grille was ,02. It fubtended air angle P ne Jnno'0f 0^429, and was of fealing-wax ; had it been a iilver one, it would have been ftill more vifible. With 879,4. All comparative magnitudes of the afteroid and flars, remain as with 496,3. The minute double ftar q Ophiuchi * was feen in high per- fection, which proves that the air is clear, and the telefcope in good order. The afteroid being now in the meridian, and the air very pure, the comparative diameter feems a little larger than that of an equal ftar, and its light alfo differs from ftar-Iight. Its apparent magnitude, however, can hardly be equal to that of the fmalleft globule obferved this morning. This globule mea- fured ,01353, and at the diftance of 9620,4 inches fubtended an angle of 0",214. When the afteroid was viewed with 879,4, more hazinefs was found than an equal ftar would have given : but this the Bo6tor afcribes to want of light. What he calls an equal ftar, is one that in an achromatic finder appears of equal light. Oct, 7. Mr. Harding's afteroid has continued its retrograde motion. The weather is not clear enough to allow the ufe of high powers. Oct, 8. If the appearance refembling the fpurious difks of fmall ftars, which I fee with 410,5 in Mr. Harding's afteroid, fhould be a real diameter, its quantity then by eftimation may amount to about 0",3. This judgment is founded on the fa- cility with which I can fee two globules often viewed for this purpofe. The angle of the firft is 0",429, and of the other 0",214 ; and the afteroid might be larger than the latter, but certainly was not equal to the former. With 496,3, there is an ill-defined hazy appearance, but nothing that may be called a difk vifible. When there is a glimpfe of more condenfed light to be feen in the centre, it rs fo fmall that it muft be Jefs than two-tenths of a fecond. To decide whether this apparent condenfed light was a real or fpurious difk, he applied different limitations to the aperture of the telefcope, but found that the light of the new ftar was too feeble to permit the ufe of tbem. From this he concluded * See Cat. of double Stars, I. 87. that t PLANET JUNO. * 293 tnat an increafe of light might now be of great ufe, and Obfervations on viewed the afteroid with a fine 10-feet mirror of 24. inches *hcPlanftt J1"1'* diameter, but found that nothing was gained by the change. The temperature indeed of thefe large mirrors is very feldom the fame as that of the air in which they are to act, and till a perfect nniformity takes place no high powers can be u fed. The afteroid in the meridian, and the night beautiful. After many repeated comparifons of equal liars with the afteroid, I think it (hows more of a difk than they do, but it is fo fmall that it cannot amount to fo much as 3-tenths of a fecond, or at leaft to no more. r - ' It is accompanied with rather more nebulofity than ftars of the fame fize. The night is fo clear, that I cannot fuppofe vifion at this altitude to be lefs perfect on the ftars, than it is on day ob- jects at the diftance of 800 feet in a direction almoft hori- zontal. x Oct. U. By comparing the afteroid alternately and often, with equal ftars, its di/k, if it be a real one, cannot exceed 2, or at moft 3-tenths of a fecond. This eftimation is founded on the comparative readinefs with which every fine day I have feen globules fubtending fuch angles in the fame telefeope, and with the fame magnifying power. *' The afteroid is in the meridian, and in high perfection. I perceive a well defined difk that may amount to 2 or 3-tenths ,_, H of a fecond ; but an equal ftar fhows exactly the fame ap- pearance, and has a difk as well defined and as large as that of the afteroid." Refuk and Application of the Experiments and Obfervations. We may now proceed to draw a few very ufeful concluflons from the experiments that have been given, and apply them to the obfervations of the ftar difcovered by Mr. Harding ; and alfo to the fimilar ftars of Mr. Piazzi and Dr. Olbers. Thefe kind of corollaries may be exprefled as follows. (1.) A 10-feet reflector will fhew the fpurious or real difks of celeftial and terreftrial objects, when their diameter is | of a fecond of a degree ; and when every circumftance js favourable, fuch a diameter may be perceived fo diftinclly, that it can be divided bv eftimation into two or three parts. (2.) A 294 ON STJAM-ENCINES. Obfervations on (2.) A difk of £ of a fecorid in diameter, whether fpurloug thcplanetJuno.orrea,^ m Qrder t0 be feen as a round> well denned body^ y ' requires a difiindr, magnifying power of 5 or 6 hundred, and mutt be fufficiently bright to bear that power. (3.) A real difk of half a fecond in diameter will become fo much larger by the application of a magnifying power of 5 or 6 hundred, that it will be eafily diftinguiflied from an equal fpurious one, the latter not being affected by power in the fame proportion as, the former. (4.) The different effects of the infkle and outride rays of a mirror, with regard to the appearance of a difk, are a criterion that will (how whether it is real or fpurious, pro- vided its diameter is more than £ of a fecond. (5.) When difks, either fpurious or real, are lefs than | of a fecond in diameter, they cannot be diftinguiflied from each other; becaufe the magnifying power will not be fufficient to make them appear round and well defined. (6.) The fame kinds of experiments are applicable to tele- fcopes of different forts and fizes, but will give a different refult; for the quantity which has been {rated at | of a fecond of a degree. This will be more when the inflrument is lefs perfect, and lefs when it is more fo. It will alfo differ even with the fame infirument, according to the clearnefs of the air, the condition, and adjuftment of the mirrors, and the practical habits of the obferver. ^ Mr. Woolf *s improvements in fleam-en- gines. XIX. Account of fame new Improvements on Steam-Engines. Arthur Woolp. By Mt. I N our eighth volume, p. 262, we gave a fhort account of a former improvement made by Mr. Woolf on the fteam- engine, founded on a difcovery that fleam, of any higher temperature than that of boiling water, if allowed to pafs into another veffel kept at (he fame temperature as the fleam itfelf, will expand to as many times its volume, and Jftili be equal to the preffure of the common atmofphere, as the num- ber of pounds which fuch fleam* before being allowed to ex- pand, could maintain on each fquare inch of a fafety-valve expofed ON STEAM-ENGINES. 295 expofed to the atmofphere : for example, that mafles or quan- Mr. WoolPs titles of fleam of the expand ve force of 20, 30, Or 50 pounds ^^7^° the fquare inch of a common fafely-valve, will expand to 20, 30, or 50 times its volume, and flill be refpeftively equal to the atmofphere, or capable of producing a fufficient a6lioh againft the pifton of a fleam-engine to caufe the fame to rife in the old engine (with a counterpoife) of Newcomen, or to be carried into the vacuous part of the cylinder in the im- proved engines firft* brought into effect by Meflrs. Boulton and Watt. In confequence of this difcovery Mr. Woolf was enabled to ufe his fleam twice (if he chofe), and with complete ef- fect; nothing more being necefTary than to admit high fleam, fuppofe of 40 pounds the fquare inch, into one cylinder, to work there by its expanfiye force, and then to allow the fame fleam to pafs into, and expand itfelf in, another cylinder of forty times the fize of the firft, there to work by condenfation in the common way. Or with only one cylinder, by admit- ting a proportionally fmall quantity of high fleam into it from the boiler, Mr. Woolf, found that he could effect a confider- »ble faving in fuel. In this firft improvement of Mr. Woolf, though the faving might be carried a confiderable length, it was ftill necefiarily limited by the ftrength of materials; for in the employment of high fleam there muft always be fome danger of an explo- jion. Mr. Woolf, however, by a happy thought, has com- pletely obviated every danger of this kind, and can now take the full advantage of the expanfive principle without the leafl danger whatever. This he effects by throwing into common ileam the additional temperature necefTary for its high expan- fion, after thefieam is admitted into the working cylinder, which is healed by means adequate to the end intended to be gained ; and the advantage which he thus gains he effectually fecures by a moft ingenious improvement in the pifton. It may be eafily conceived that fleam of fuch high rarity as Mr. Woolf employs, could not be made fully effective with the pifton in common ufe; for in proportion to its rarity fo muft be the facility w,ith whtch a portion of it would efcape, and pafs by the fide of \he pifton to the vacuous part of the cylinder : but Mr. WoolPs contrivance feems perfectly adapted to prevent the lofs of even the fmalleft portion of the fleam, * ■ * Befide* 29(5 SCIENTIFIC NEWS, Befides tliefe improvements on the common fleam-engine, he has alfo found means to apply (he fame principles to the old engine, known by the name of Savary's, in fuch a way as to render the fame a powerful and ceconomical engine for a great variety of purpofes. Such is the outline of Mr. Woolf's improvements on this ufeful engine: but, for the general information of practical engineers, we ftiall fubjoin a more technical ck fcription, in Mr. Woolf's own words, extracted from his fpccification of his patent. (To be continued.) . SCIENTIFIC NEWS. Geometry* Two theorems -O^UYGENS has given the two following theorems in his from the Ho- Horolo»ium Ofcillatorium, which are applicable to all folid rologium of o j > rr Huygens. bodies: " The center of of dilation, and that of fufpenfion are always reciprocal to one another. The fame body is always ifo- chronal to itfelf while it ofcillates round parallel axis's taken at equal diftances from the center of gravity. M. Biot has given a remarkable extenfion to thele two theorems. —extended far- All thefe parallel axis's form the furface of a right angled tner by M. cylinder of which the axis paiTes through the center of gravity. But the analytical expreflion under which M. Biot prefents the theorem of Huygens, made him inflantly perceive, that an arbitrary inclination might be given to this axis, the radius of the cylinder being fuitably changed at the fame time; and that thus according to the different degrees of inclination of the axis, an infinity of cylinders might be obtained. The fuperficies of which cylinders fliould have the fame property as that of the primitive cylinder. Befides this, the axis without changing its inclination may defcribe a conical furface about its primitive pofition, which will multiply the number of cylinders already found, as often times as right lines can be conceived to be drawn on the upper furface of the cone, 5 Aftronomy^ SCIENTIFIC NEWS. 297 AJlronomy. M. Pictet has made an obfervation of an occultation of the M. V\€ttt on pleiades by the moon, on the 19th of November, 1804, from ofthTpHadeTby the Obfcrvator^ of Geneva. the moon. An account of an occultation of v fcorpion, obferved on M. Mechain o the 17th of July, 1803, from the fummit of Cafuteta, a^^^J mountain in the kingdom of Spain, was found among the papers of the late M. Mechain, which will appear in the 6th Volume of the Memoirs of the French National Inflitule : this is the laft obfervation of this kind made by a man of fcience, whofe premature lofs thelnftitute will long regret. A long fucceffion of obfervations was alfo found among and of the comet his papers, relative to the comet which he had difcovered m ,793« from Barcelona in 1793, which will alfo appear in the fame publication. Geography, M. Humboldt has read before the Inftitute Nationale, A The longitudeof Memoir on the Longitude of Mexico, the capital of the king- Mexico deter- . ,. „ . * mined accurately dom to called. by M. Hum- Geographers difagree with regard to the pofition of this holdt. important point. The confiderable difference which M. Humboldt found between his firft obfervation, and the laft which had been formerly made by others before him, engaged him to repeat it as often as he could, and by different methods. The distances of the moon from the ftars, and feveral eclipfes of Jupiter's moons, always gave the fame refult, which is doubt! efsly preferable to all thofe which have appeared hitherto. Electricity. Since the difcovery of electrical conductors by Dr. Frank- Conductor con- lin, many philosophers have repeated experiments to eftablifh trived t0.Pre* . . . . r r ' . , - * ,. , , . , . A vent accidents, the identity of electrical nre and lightning, by experiments with iuch infolated conductors. , Thefe experiments fucceeded to the wifti of all who tried them ; but it was foon perceived, that they were attended with much danger : and fince the death of Profeflor Richman, of Peterfburg, who was ftruck by lightning from his con- ductor in 1753, few ha,ye ventured to repeat the experiment. M, Beyer 238 SCIENTIFIC NEWS. M. Beyer of Paris has formed in his garden an apparatus of this kind, which is very fimple, and at the fame time can be infolatcd perfectly, effectual without any danger: It is a conductor pk2e.at wnich can, alternately at pleafure be infolated, or not infolated, and made to aft either with a ball, or with a point. The communications between it and the earth are well eflablifhed, and as the obfervations can be made at more than an hundred feet from the apparatus, there is not the Jeaft danger of any accident. ..Mrpjlation. Balloon projeft. The celebrated Aeronaut Robertfon, who afcended from bertfon, 13* feet Pcterfburg lafl, year, is endeavouring to obtain the neceflary diameter, afliflance at that place for the conftruclion of an air balloon me""7 U? 5° on a vei7 Jar£e fcale; he propofes that it (hall be 732 feet in diameter, which he calculates will carry up 37 ton, and which he fuppofes, therefore, will eafily fupport 50 people^ and all neceflary accommodations for them, andaveffel It is to have attached to it a veiTel furnifhed with marts, yn ails, c. ^ajjs^ ancj every 0ther article requifite for navigating the fea in cafe of accidents, and provided with a cabin for the aeronauts, properly fitted up, galley for cooking,(proper ftores and an internal for flowing proyifians, and feveral other conveniences. To parachute1, render the afcent more lafe, it is to take up another fmaller balloon within it, and a parachute, which will render the defcent perfectly gentle, if the outer balloon burfls. From its conftruciion it will be calculated to remain in the air feveral weeks, in which time many experiments in natural philofophy, and agronomical obfervations may be made : It is alfo fuppofed, that geography may be confiderabiy improv- ed by its means, as the aeronauts will be neither flopped in their courfe by mountains or forefts ; and fome have even thought, that with the afliflance of the trade winds, a voyage round the earth might be made in it between the tropics. Its coft, it is calculated, will be nearly equal to that of a ftiip of the line. UuiverfUy of Charkow, The court of Petersburg publifhed the act of confirmation of the Univeriity of Charkow, on the 16th of May, of whicfy the following are the chief particulars. The SCIENTIFIC NEWS. 299 The Univerfity is under the care of the Minifter of public infttudion : It has, however, its own particular administration q^™^^ and jurifdiclion ; the ordinances, by which its members are regulations. governed, are regulated by itfelf: It has the right of cenfure ^usPrivi- both with regard to the books printed by itfelf, or thofe brought from abroad. All articles which it may want are allowed to pafs the frontiers without examination or tax. Its corrcfpondence is poft free, and its paper is not fubjeft to duty. The houfes of the profeflbrs are free from taxes and .all charges. The profeflbrs have the rank of the feventh Frovifion for clafs, and the fludents that of the twelfth, or that of fubaltem Profcir°rs> &c' officers, receive commiffion as fucb, and wear fwords. The profeflbrs after twenty-five years duty, or in cafe of incurable ficknefs, receive their penfions for life, and may even receive them while refident in other countries. On the death of a profeflbr, his widow and children continue to receive hiss penlion, until the widow marries again,, or the children attain the age of twenty-one years. The Emperor has granted a yearly revenue to the Univerfity of 130,000 rubles. Botanic Garden> fyc. at Copenhagen. A fura of 4,500 rix dollars, which the government had granted in \ 80:3, for the Botanic Garden at Copenhagen, has been employed, partly in paying the debts of the eftablifh- ment, and partly in conftrufiing a new hot-houfe. This has 5500 plant? garden, which pofleffes 3,500 plants of different kinds, js^^peOion, open one day in each week, for the curious, and every day for botanic ftudents. The directors in their laft report, hav- tng.made fome propofals for the improvement and eftablifh- ment of the garden, the government has granted them an additional fum of ' 4000 rix dollars, and an annual fum of additional grants £00 for repairs; and have befides fettled, that the appoint- ma ments of perfons employed in the garden, fliall be increafed to 720 rix dollars, to commence this year. M. Giefecke, a Pruffian mineralogifr, who ha$ been a Propofed mine- oonfiderable time at Copenhagen, is about to be employed raIoSlcal exPedi- . ° ' ,,, J tIon t0 Green- by government on a voyage to Greenland, where he is to land. pafs fome years in examining that country, with regard to its mineralogy and geology. Hitherto the Moravian religious miffionaries have alone been able to refolve to live fome years 300 SCIENTIFIC NEWS. years in that country for the converfion of the natives : It will be no little honour to the fciences, if M. Giefecke ftiall bring himfelf to make a like facrificc for their advancement. Charts printed The Royal Academy of the Fine Arts, and the Mechanical types!*6* C ^rts °^ Betlib; have received among their members M. F. H. Wagener, who has difcovered a new method of printing geographical charts by a fpecies of moveable types, which is found to anfwer better than engraving, -and will undoubtedly be much cheaper. . —*wm— ■ Prizes given by Marflial Berthier, war minifter of France, at the requeft the French 0f ger,era{ Marefcot, has again eftabliflied the prizes which war minifter for ° . * b ; r was given tor the belt works on fortification. a work on fub- Two prizes have been granted to the bell treatifes on fub- terranean for- terraneous izorks. The firft was adjudged by the committee ti cation, o^ fortification to Major Mouze, the fecond to Captain Gillot; the committee has adjudged a third treatife defer ving of honourable mention, which has for its infcription artem experienlia fecit ; the author of it is not known, and one on a Another prize on the fubject of a project for a fortified plan rorafom- iarrae/Cf nas Deen given to Captain Laurent. The com- mittee have judged the project of Captain Biofchevalier, -and that of Lieutenant Colonel Gefbert, to deferve honour- able mention. The committee has rejected, for not corref- ponding with the pTOpofed fubject, a project of Captain Mallet, for a barrack intrenchment ; but have thought it worthy of particular mention, as a work which gives a very ad van ta- geous idea of the talents of this officer. Many of the works which neither received prizes, or par- ticular mention, exhibit ingenious contrivances, and interest- ing obfervations. In general thefe two contefts have fully » proved the goodnefs of the Institution, of which the object is to exite emulation in all the corps of the army, to propagate knowledge among them, and to extend the perfection of all the branches of the military art. Catalogue of THE catalogue of the Leipfic fair, has this year contained Leipftc fair, con- ^vo flieets more than ufual. The mufical publications have turned 3647 been publications. w^w* SCIENTIFIC NEWS. 301 keen added to it. It contains 3,647 articles, furmthed by 380 bookfellers. The number of romances is 271, of thea- trical pieces 81, and muiic 95, forms 4-47 articles. The academy of painting and fculpture at Madrid, are Publication of about to publifti a compleat coile&ion of the Arabic antiqui-ti^ofspahir* quities of the kingdoms of Grenada and Cordova. In this work will be found not only views and plans of the monu- ments, and other remarkable matters of thefe countries, but alfo an explanation of all the infcriptions, cyphers and hiero- glyphics. THERE is foon to be publifhed at Lifbon, a Diaionary 0fDiaionary°f the Angola or Bunda language, with the explanation of al}gUage> fervice- the words in Portuguefe. There has never before been aabletothofe diaionary of this language. This will be publifhed for the jjg ^J^ life of thofe Portuguefe who have buiinefs to tranfaa with the eftablimments which their country pofleffes on the coaft of Africa. No language is fpoken there to fo great an extent as tikis. THE celebrated fculptor M. Canova, is engaged in erecl> Maufoleaimf ing at Vienna, the fplendid Maufoleum of the Arch-dutchefs^1'^^ Chriftina, an immenfe compofition of eight marble figures, larger than life ; the models and execution of which have been long admired at Rome, where they were formed. M. Canova before his departure from Rome exhibited a and his Thefcus coloflal group, reprefentingThefeus combating with a Centaur. an entaur* This group is to be executed in marble for the city of Milan. The artifts and connoifleurs of Rome feem to efteem this work fuperior to every other which has been executed by this ingenious and indefatigable artift. THE Magiftracy of Augfburg have had the honour of piracy of books being the firft government of fouth Germany, which have pumped at taken decifive meafures againfl the fhameful traffic of book-Au^Urg* piracy. It has- conflfcated the entire edition, confiding of 500 impreffions, of the work of Goener, on the political rights ift)2 SCIENTIFIC NEWS. rights of Germany, which was pirated by Krauzfelder, & dealer in fueh tranfactions, and has betides compelled Krauz- felder to pay 1o the legitimate editor, the price of the copies which he had fold* Ruffian marine Initiation. THE "Ruffian government have formed at Petersburg, art Inflitution, whofe deiign is the perfecting of all that belongs to naval armaments, and which is to be called the Marine Mufeum. This infiitution is not merely to be a fchool : all the fciences neceflary to a naval officer will be there taught and the Mufeum will befides publifh a journal which will treat of every thing relative to the marine. It will have alfo a cabinet of natural hiftory, which will be open to all the pupils. This eftablifhment will be under the direction of the miniiter of the marine, and its members are to wear the naval uniform. » Ruffian efta- Hi foments for education. Numbers of matters and pupils* ACCORDING to the report of the minifter of public in- struction, there is at prefent in Kuflia 494 inftilutions for educa- tion, direcled by J 475 matters, and attended by '334S4 fcholars. The expence of thefe eftablifhments cods government annually almoft two millions of Rubles. Among thefe are not reckoned thofe for the corps of cadets, or for pages, the Academy of Arts, the Schools of Commerce, nor the Infiitu- tion for Female Education. Thofe who know the ftate in which Ruffian education was at the acceffion of Alexander, may judge by this detail what he has done towards enlightning his vaft empire. The Ruffian catholics earneftly concur in feconding his views. At an ecclefiaftical affembly, convoked by the bithop of Lufk and Shetomir, various meafures have been taken in favour of the eftablifhments for education. Theatre in the Crimea, IN the town of Odefla in the Crimea, a theatre is building with much activity, according to the plans of M. Thomas de Thomon architect to the Emperor, and a profeffor of the Peteitburg academy*' This SCIENTIFIC N£W«. 303 (This (hews that the arts are even extending to this hitherto ttegle&ed part of the world, which certainly from its fine' climate, and many other advantages, merits every attention of its enlightened and humane matter.) THE third volume of the Geographical Dictionary of tlte Geographical Rufian Empire has been publifhed by the bookfellers, Gavy, Ru^°a"aryof Popow, and Luby, AN" important work is foon expe&ed to appear at Peterf- burg, by the fcientific M. Delaunay, counfelior of ftate, re- lative to Siberia, and the bordering countries. M. KOTZEBUE in his laft tour to Naples relates fome Ancient manu- particulars which he faw in vifiting the Mufeum of Portici, edat PorticTare which will be interefting to the admirers of ancient literature. " Eleven young men are at prefent employed in unrolling the manufcrips, and two copy them. An Englifhman called Haiter, is at the bead of the eitablifhrrient. He relates that his affiftants are much more expert and expeditious than they were formerly. He has great hope that he lhall have the 600 manufcripts, (which yet remain) deciphered, and has little doubt that he (hall difcover among them an Ennius and a Me- nander, as he flatters himfelf he has already a Poiybius in hands. On the day of the vifit, a Greek author, hitherto unknown named Kolotos, was difcovered; his work is on philofophy. As the names of the author are always inferted at the end of each manufcript, they can never be known until it is entirely unrolled. Seven latin authors have paflfed through the hands of Mr. Haiter, but all fo much damaged that it was impoflible to unroll them, which he the more laments as one of them appeared to be a' ' Livy, at leaft it was an hiftorical work ' written in his ftyle ; all that he can difcover of it, is, that it begins with an harangue, in which mention is made of the family of Acilius. They have to this time difcovered five authors ; Philodemus, mofl of whofe writings have been found, and among others, a treatife on the vices which are nearly, allied to virtues. Epicurus, Ph#drus, Demetrius Phalereus the works of and EPicurus» fjSdrus, 304» Scientific news, Demetrius, and* and his Kolotos above-mentioned. Mr. Hailer regrets that he* has hitherto only met with works on philofophy, although among thefe many historical ideas, hitherto unknown, occur , here and there : as happened in a differtation on anger, in , which is cited the example of Cadmus punifhed by Bacchus for having given himfelf up to this paffion, a circumftance hitherto unknown. IT has for fome time been an object of deliberation with me, to afcertain by what means I might molt effectually remedy an inconvenience which has arifen from the dif- tinguiflied patronage this Journal has been honoured with : The great extent and value of original communications can- not but be duly eftimated by the public ; though at the fame time it has neceflarily followed, that various articles of news and other fubje&s in the foreign Journals, have in many in- ftances been poftponed, and in fome rejected. To retain all •the peculiar advantages of this work, and to afford ample fpace for occafionai and foreign articles of value, the obvious means have appeared, that according to tlje practice of feveral other refpe6table works, each volume thould be concluded by a Supplementary Number ; containing fix (beets, or 96 pages of printed matter, and two plates. And, as many of the former plates, like thofe in the prefent number, have con- tained mathematical figures or outline delineations, capable of being advantageoufly condenfed, it is purpofed in all the future numbers to give two very full plates, and fixteen extra pages of matter, inftead ©f the four plates hitherto given. By this arrangement every volume will in future contain 30 iheets or 480 pages of matter, and 10 full plates ; inftead of 20 meets or 320 pages, with 16 plates lefs fully occupied. This addition of new matter to the amount of full one half Kiore, will admit the infertion of many interefting article* which want of 100m muft alfo have excluded. %* Tlie plate of Rye- Harbour could not be finijhed in time on account of the fudden illnefs of the Engraver, It mil bt given gratis in the Supplement, which will be fublijhcdjan, I* next, at the fame time as No, 50. ■ithoLronb Fhilvs. Journal. VolJUTUHEp. 306. Ty.l. Fig. 4. A. B T use J&itf. . Jc.Jtu&tB iic Mcfwlson^ Thilos. Journal. Vo l.XH.FlXIVp.306. £r £rfttyu^M^j^r& <^wry /minors trAecfa, Fig. I. *30 27 1/ Ofc 1%.2. *4(%fr*f68 b> m0vin£ one to admit air towards the duct A, forms a vacuum in the barrel. When it from the receive £-;s , t[ie du6l A. it opens a communication between the and the other to -*X*n * above what is to be met with in other pumps, happens only at the fma!J interval while the fpring pifton is paffing from its natural fituation to the du6t B. This need not be more than about four times greater than that which is requifite to over- come tbefri&ion of the pifton P, and will be eafily provided or by increafing the proportion between the diameter of the pinion wheel and the fweep of the handle. ELIZUR WRIGHT, C.A.S. Canaan (Connecticut in America,) March 12, 1805. II. Concerning the Stale in which the true Sap of Trees is depofded during Winter, By Thomas Andrew Knight, Efq* (Concluded from Page 240) bulbous andtu- VV E have much more decifive evidence that bulbous and berous roots tuberous rooted plants contain the matter within themfelves ter* that forms " wn*cn fubfequently compofes their leaves; for we fee them .leaves, vegetate even in dry rooms, on the approach of fpring; and many bulbous rooted plants produce their leaves and flowers with nearly the fame vigour by the application of water only, as they do when growing in the beft mould. But the water in this cafe, provided that it be perfectly pure, probably affords little or no food to the plant, and ads only by diflblving the * Phil. Tranf. of 1805, p. 91. matter STATE OF THE SAP IN WINTER. 309 tkmtter prepared anddepofited in the preceding year ; and hence the root becomes exhau (led and fpoiled: and Haflenfratz found that the leaves and flowers and roots of fuch plants afforded no more carbon than he had proved to exift in bulbous roots of the fame weight, whofe leaves and flowers had never expanded. As the leaves and flowers of the hyacinth, in the preceding —and it Is cafe, derived their matter from the bulb, it appears extremely ^f^ewtlm-* probable that the bloflbms of trees receive their nutriment from tain the nutri- the alburnum, particularly as the bloflbms of many fpecies me.nt 0^thc"v precede their leaves : and, as the roots of plants become weak- ened and apparently exhaufted, when they have afforded nutri- ment to a crop of feed, we may fufpect that a tree, which has borne much fruit in one feafon, becomes in a fimilar way exhaufted, and incapable of affording proper nutriment to a crop in the fucceeding year. And I am much inclined to believe that were the wood of a tree in this ftate accurately weighed, it would be found fpecifically lighter than that of a fimiiar tree, which had not afforded nutriment to fruit or bloflbms, in the preceding year, or years. If k be admitted that the fubftanee which enters into the The preparation corapofition of the firft leaves in the fprine- is derived from /? "u,m" m ' * ° me,nt in the trea matter which has undergone fome previous preparation within implies thatthe *he plant, (and I am at a lofs to conceive on what grounds this Julces circulate» can be denied, in bulbous and tuberous roofed plants at leaft,) it muft alio be admitted that the leaves which are generated in the fummer derive their fubftanee from a fimilar fource; and this cannot be conceded without a direcf admiflion of the •exiftence of vegetable circulation, which is denied by fo many eminent naturalifts. I have not, however, found in their writ- ings a tingle fact to difprove its exiftence, nor any great weight in their arguments, except thofe drawn from two important errors in the admirable works of Hales and Du Hamel, which I have noticed in a former memoir. I (hall therefore proceed to point out the channels, through which I conceive the circu* lating fluids to pafs. When a feed is depofi ted in the ground, or other wife expofed Explanation of , ... * t > c - the manner in to a proper degree of heat and moilture, and expofure to air, wWcj1 thejuiox water is abforbed by the cotyledons and (he young radicle or of plants circu- root is emitted. At this period, and in every fubfequent ftage J^ * c^n^g of the growth of the root, it increaies in length by the addition &c. of new parts to its apex, or point, and not by any general dif- * tend on 310 STATE OF THE SAP IN WINTER. Explanation of tenfion of its veflels and fibres ; and the experiments of Bonnet whicTtTej^ces and Da Hamd ,eave litt,e grounc^s of doubt, but that the new of plants circu- matter which is added to the point of the root defcends from the late, their habi- cotyledons. The fuft motion therefore of the fluids in plants is tudes, changes, , ' &c. downwards, towards the point of the root ; and the veflels which appear to carry them, are of the fame kind with thofe which are fubfequently found in the bark, where I have, on a former occafion, endeavoured to prove that they execute the fame office. In the laft fpring I examined almoft everyday the progrefiive changes which take place in the radicle emitled by the horfa chefnut: I found it, at its fir It exiftence, and until it was fome weeks old, to be incapable of abforbing coloured infufions, when its point was taken oft', and I was totally unable to dii- cover any alburnous tubes, through which the fap abforbed from the ground, in the fubfequent growth of the tree, afcends: but when the roots were confiderably elongated, alburnous tubes formed; and as foon as they had acquired fome degree of nrmnefs in their confidence, they appeared, to enter on their office of carrying up the aqueous fap, and the leaves of the plumula then, and not fooner, expanded. The leaf contains at leaft three kinds of tubes : the firft h what, in a former Paper, I have called the central veflej, through which the aqueous fap appears to be carried, and through which coloured intufions readily pafs, from the alburnous tubes into fhe leaf-ftalk. Thefe veflels are always accompanied by fpiral tubes, which do not appear to carry any liquid : but there is another veflel which appears to take its origin from the leaf, and which defcends down the internal bark, and contains the true or prepared fap. When the leaf has attained its proper growth, it feems to perform precifely the office of the cotyledon ; but being expofed to the air, and without the fame means to acquire, or the fubftance to retain moiflure, it is fed by the al- burnous lubes and central veflels. The true fap now appears to be difcharged from the leaf, as it was previoufl y from the cotyle- don, into the. veflels of the bark, and to be employed in the for- mation of new alburnous tubes between the bate of the leaf and the root. From thefe alburnous tubes fpring other central vef- fels and fpiral tubes, which enter into and poflibly give ex- iftence to, other leaves; and thus by a repetition of the fame procefs <.STA*E OF THE SAP IN WINTER. 311 procefs the young tree or annual (hoot continues to acquire Explanation of 1 J ° _ ,. the manner m new parts, which apparently are formed from the atcendmg ^-lch the juices aqueous fap. of P,ant? *j*" n . . . ~ tt , . , n -j r -i i late, their habi- But it has been proved by Du Hamel that a fluid, nmirar to tudeS) changes, that which is found in the true Cap veflels of the bark, exifts &c. alfo in the alburnum, and this fluid is extremely obvious in the fig, and other trees, whofe true fap is white, or coloured. The veflels, which contain this fluid in the alburnum, are in con- tad with thofe which carry up the aqueous fap ; and it does not appear probable that, in a body fo porous as wood, fluids fo near each other fhould remain wholly unmixed. I mutt there- fore conclude that when the true fap has been delivered from the cotyledon or leaf into the returning, or true fap veflels of the bark, one portion of it fecreles through the external cel- lular, or more probably glandular fubftance of the bark, and generates a new epidermis, where that is to be formed; and that the other portion of it fecretes through the internal glan- dular fubflance of the bark, where one part of it produces the new layer of wood, and the remainder enters the pores of the wood already formed, and fubfequently mingles with the afcending aqueous fap ; which thus becomes capable of af- fording the matter neceflary to form new buds and leaves. It has been proved in the preceding experiments on th.e afcending fap of the fyeamore and birch, that that fluid does not approach the buds and unfolding leaves in thefpring, in the ftate in which it is abforbed from the earth : and therefore we may conclude that the fluid, which enters into, and circulates through the leaves of plants, as the blood through the lungs of animals, confifts of a mixture of the true fap or blood of the plant with matter more recently abforbed, and lefs perfectly aflimilated. It appears probable that the true fap undergoes a confider- able change on its mixture with the afcending aqueous fap ; for this fluid in the fyeamore has been proved to become more fenfibly fweet in its progrefs from the roots in the fpring, and the liquid which flows from the wounded bark of the fame tree is alfo fweet ; but I have never been able to detect the flighteil degree of fweetnefs in decoctions of the fyeamore wood in winter. I am therefore inclined to believe that the faccharine matter exifting in the afcending fap is not immedi- ately, or wholly, derived from the fluid which had circulated through 312 STATE #F THE SAP IN WINTER. Explanatioa of through the leaf in the preceding year; but that it is gene- manner in which the juices ratec* Dv a procefs fimilar to that of the germination of feeds, of plants circu. and that the fame procefs is always going forward during the tudes, changes'" ^Prmg'ant^ fummer, as long as the tree continues to generate *c. new organs. But towards the conclufion of the fummer I conceive that the true fap (imply accumulates in the alburnum, and thus adds to the fpecific gravity of winter-felled wood, and increafes the quantity of its extractive matter. I have tome reafons to believe that the true fap defcends through the alburnum as well as through the bark, and I have been informed that it the bark be taken from the trunks of trees in the fpring, and fucli trees be fuffered to grow till the fol- lowing winter, the alburnum acquires a great degree of hardnefs and durability. If fubfequent experiments prove that the true fap defcends through the alburnum, it will be eafy to point out the caufe why trees continue to vegetate after all communication between the leaves and roots, through the bark, has been intercepted: and why fome portion of alburnous matter is in all trees* generated below incillons through the bark. It was my intention this year to have troubled you with fome obfervations on the reproduction of the buds and roo's of trees; but as the fubject of the Paper, which I have now the honour to addrefs to you, appeared to be of more im- portance, I have deferred thofe obfervations to a future op- portunity ; and I (hall at prefent only obferve, that I conceive rayfelf to be in pofleflion of facts to prove that both buds and roots originate from the alburnous fubftance of plants, and not, &s is, I believe, generally fuppofed, from the bark. I am, &c. T. ANDREW KNIGHT. Elton, Dec. 1, 1 804. * I have in a former paper ftated that the perpendicular moots of the vine form an exception. I fpoke on the authority of numerous experiments; but they had been made late in the fummer; and on repeating the fame experiments at an earlier period, I found the refult in conformity with my experiments on other trees. Singular BAKED HOUSES OF INDIA. 3\$ III. Singular Method of forming Walls and Hoofs of Rural Build- ing, in Indojtan, communicated by M. Legoux de Flaix, Officer of Engineers *. 1- HC nethod which the Indians have ufed for many years, Advantages of of forming their rural buildings, unites folidity, convenience, tuHdTng. ° ° and Miblefomenefs to economy, and facility of execution. Houfes ronttfJicled in this manner have alfo the advantage Refifts fire -ani of Toeing abu-utely Cafe from conflagration, and of refitting inUlKiations• ev^'i ie' molt /doiert inundations. In a fnntry where ftone is fca^ce, the rich build their hoi^< a'!) brick's which in many refpe<5ts are preferable to ftoni • but poor people, fuchasthofe employed in agriculture, canro» :n to that expence, even in India, where labour and materials are fo cheap. The habitations of villagers in moil parls of the globe are bu be of an uniform confidence. It is then moiftened with water. with water five or fix hours before it is wanted, and in the quantity neceffary for a (ingle day's work alone. The wills are The mixture thus prepared is carried to the place of build- rated al1 1<^°" ing, when the foundations are perfectly dry, and the walls are then built equally in every part at the fame time, on a perfect level, in courfes, and brought up perpendicularly : each courfe from two to four of earth is from eight to ten inches in depth, and the whole feet thick. breadth of the wall, which is feldom lefs than two feet thick, and never exceeds four; which ditnenfions are always re- gulated by the intended height of the building, and the force fnonetwoor of the floods, if it is near the river. When the walls are three courfes in three feet aml a half, or four feet thick, only one courfe is a day according * ' ■* *othe thicknefs. raifed in a day; but when they are from two feet and half to three feet thick, two courfes are railed, and if they are but two feet thick, three courfes are fometimes raifed in that fpace of time. This depends on the quicknefs of the defic- cation of the walls, which fpeedily takes place there, where the drynefs of the air is extreme : this would not perhaps happen in our moift climates ; if this method of building fhould be tried here, it would probably be neceflary to leave them longer to dry, in order to obtain the requifite tenacity. Spaces left for When the walls are built to the height for the roof, the beams, doors, pr0per openings are made for the beams and joifts. It is 2nd. windows* almoft needlefs to add, that the apertures neceifary for tke doors and windows are made while the walls are building. The walls when On the twelfth or fifteenth day, or when the walls are dry areenclofed fufficiently dry, or to the fame degree to which tiles are dried, in open work ,, r 11 1 • n • 1 " c L cafes of bamboa, the walls are iurrounded externally and internally with a iort of open work cafe, made of (pars of bambou, or of lome other hard and dry wood. In Indoftan, where this method of building is general, the workman have bars of iron, which they hire out, that ferve to fuilain the coffer work mentioned, at two or three and are placed at every three or four yards; the coffer work feetdiftancc, js raifed at two or three feet diftance from the furface of the fitted* with^cL w»i]s, according to their thicknefs, and the fpace between is filled up with firewood, turfs, and cakes made of cow and (heep dung worked together and dried in the fun. BAKED H0USFS OF INDIA. 315 This pile of combuftibles is arranged in feveral ftages, Arranged in of three, four, or five feet thick, feparated from each other J3^^"/*3 by layers of earth or half dried turf of from eight to ten earth. inches depth ; the upper ftages are firft fet on fire, fo that the The upper fhges wall is baked through its whole extent from top to bottom. ^kindled* The charge of the combuftibles for each of the ftages is fo managed, that the lowed is the greateft, and is diminished for each as it is nearer the top of the wall ; as the pile burns down the fire of the lower ftages ftill acts on the upper part of the walls, which permits tiae upper ftages to be of lefs thicknefs. The fire bakes the walls to a thicknefs of from Walls thus fcaked fix to ten inches, as tiles are baked in a kiln. And thus walls 0ffroem £ " are built in a fingle piece, and of the greateft folidity, which ten inches, have the more ftrenglh, as there are no junctures in them. Wherefore they ought to prevent the greateft poflible refift- ance to the action of the atmoiphere, the attacks of floods, and the fall of rain, which defcends in torrents in moll countries of Indoftan during the rainy feafon. Experience has conftantly proved, that the houfes built in Thefe houfes this manner not only laft much longer than thofe built blJjJftSjfijj? bricks, but that they alfo refill belter the attacks of the and refift floods periodical inundations, and thofe of tbe annual rains to which and raln bettcr# they are expofed in this climate. The method in which the terrace roofs (which are called Their roofs are in India argamace) are formed for thefe houfes, is the J£*ee byeis*1* following : Immediately after the baking and cooling of the walls, the allies and the bars which fuftained the coffer work are re- moved. ■ The beams and joifts are placed, and covered either with very thin boards, or elfe with fmall green branches; and upon this fupport the different layers of the terrace roof are placed. The firft layer is fim ply clay, with an equal Firft Jaycr cam- quantity of ok, afpecies of marl in powder, which is pounded a ^-mA ofmzr) '* in trough*, fuch as are ufed for preparing mortar. This firft layer four or five is four or five inches thick, and it is then levelled, and is mches thick* moiftened from time to time, in order- to beat it firm with fmall bats. As foon as this is dry, the fecond layer is laid on, which confifts of potters clay worked up in the fame manner Second layer as if prepared for making pottery; this layer is only two JJ^*1^^® or three inches thick at moft. It is levelled according to the thick, flope of the terrace, which is given it in placing the beams and 31G Third layer clay with one fourth brick duft and one fourth fine land 6 or S inches thick. Hbufes thus built cod 6 franks for the cubic fathom. May be made with many flo- ras. An houfeof this fort 430 years built feemed w temperature, or even from water itfelf, admitted into the fteam veflel or vefTels, all the elfecls that can be ob- • . ' tained from .fteam of a high temperature, without any of the «J|g GVf S1EA.M-ENGINCS, %U. Woolfs the "& wilii which the production of the" latter is accorri* improvement* panied, not only to the boiler and other parts of the ma. sines- chinery, but even to the lives of the workmen ; for fuch low fleam, or even water, (but in every cafe fleam is pre- ferable,) being admitted into a fteam veflel or veflels, or working cylinder or cylinders, kept at the requifile higher temperature by the forementioned means, wilt there be ex- panded in any ratio required, and produce an effect in the working of the engine which cannot otherwife be obtained but at a greater expenfe of fuel, or with the rifk of an ex- plofion. By this means I can make ule of fteam expanded in any required ratio, or of any given temperature, without , the neceffity of ever having the fteam of any greater elas- ticity than- equal to the preflure of the common atmo- fphere. *' Another improvement which I make ufe of in fteam- engines confifts in a method of preventing, as much as poffible, the paflage of any of the fteam from that fide of the pifton which is acted upon by the faid fteam to the other fide which is open to the condenfer; and this I ef- fect, in thofe fleam-engines known by the name of double engines, by employing upon or above the pifton mercury or fluid metal, or metals in an altitude equal to the preflure of the fteam. The efficacy of this arrangement will appear obvious, from attending to what mud take place in working fuch a pifton. When the pifton is afcending, that is, when the fteam is admitted below the pifton, the fpace on its other fide being open to the condenfer, the fteam endeavouring to pafs up by the fide of the pifton is met and effectually pre- vented by the column of metal equal or fuperior to it in preflure, and during the down ftroke no fteam can poflibly pafs without firft forcing all the metal through. In working what is called a tingle engine a lefs confiderable altitude of metal is required, becaufe the fteam always acts on the upper tide of the pifton. For tingle engines, oil or wax, or fat of animals, or fimilar fubftances, in futlicient quantity, will anfwer the purpofe, if another improvement, which conftitutes part of my faid in* vention, be applied to the engine, namely to take care that la either the double or Angle engine fo to be worked, the outlet that conveys the fteam to the condenfer fhall be io po- filed, and of fuck a iize, that the fteam may pafs without forcing OX STEAM-ENGINES. 819 forcing before it or carrying with it arvy of the metal or other M1"'^^1^ fubftance employed, thai may have pafled by the pifton; taking m fleam-en- care at the lame to provide another exit for the metal or other I»& fubftance colleded at the bottom of the fleam veflel or working cylinder to convey the fame into a refervoir kept at a proper heat, whence it is to be conveyed to the upper fide of the pifton by a fmall pump worked by the engine or by any other contrivance. In order that the fluid metal or metals ufed with the pifton may not be oxidated, I. always keep fome oil or other fluid Jubilance on its furface, to prevent its coming in contaft with the atmofphere ; and to prevent the neceffi.ty of employing a large quantity of fluid metal, I generally make my pifton of the depth of the column required, but of a dia- meter a little lefs than the fteam veflel or working cylinder, excepting where the packing or other fitting is neceflary to be applied ; fo that, in fafil, the column of fluid metal forms only a thin body round the pifton. In fome cafes I make a hollo vr metallic pifton, and apply an altitude of fluid metal in the infideof the working cylinder. " It may be neceflary, however, to ftate, that in apply- ing my improved method of keeping the fteam velTels of fteam- engines at any required temperature to the engine known byr the name of Savary's, in any of its improved forms, in which a feparate" condenfer has been introduced, I fometimes employ oil (or any other fubftance lighter than water, and capable of being kept fluid in the temperature employed, without being converted into vapour,) in the upper part of the tube or pi^e attached to the fteam veflel ; by which means fteam of any temperature may be ufed without being expofed to the rifle of partial condenfation by the admiffion of any colder body into the fteam veflel ; for the oil, or ether fubftance employed for this purpofe, foon acquires the requifite temperature j and to prevent unnecefTary efcape of heat, I conftrucl: of, or line with, an imperfect conductor of heat, that part of the tube or pipe attached to the fteam veflel which may not be heated ex- teriorly. And further, (as is already the practice in fome en- gines, and therefore not excluflvely claimed by me,) I caufe the water raifed by the engine to pafs off through another af- cen ling tube than tire one attached to the fteam veflel, but connected with it at fome part lower than the oil or other U5£C employed in it is ever fuflfered to defcend to in the working 320 MAGNESIAN EARTH; working of the engine. The improvement which I have judr mentioned, of introducing oil into the pipe attached to the fleam veiTel of fuch engines, may alfo be introduced without applying heat externally to the fteam veflfel ; but in this cafe part of the effect which would otherwife be gained is loft." v. On the Magneftun Earth of Baudijfero. By M. G i o e e r t. (Concluded from Page 284.) The earth of JL O afcertain the proportions of thefe conftituent parts of Baudiflerp ana- faQ magnefian earth, we lixiviated a given weight of it, and precipitated the fulphuric acid from one part of it by acetite of barytes, and the lime from the other part by oxalate of ammonia. It contains be- The weight of the oxalate of lime, and that of the fulphate fides magnefia, of barytes, obtained from it, fhewed us that it contained 1,60 fulphate of lime, of ^ fa,phate of jy^fi" The eXperiments before recited de- — with filex, termine the proportion of the (ilex contained. — d b 'c ^° Prove tnat °^ lne carbonic acid, we both calcined a given acid, weight of the earth in crucibles, from which fyphons paffed into bottles containing lime water; in order that the carbonic acid gas furnimed by the earth might be precipitated, and alfo dlflblved confiderable quantities of it in acids by the aclion of heat, and received the gas produced in bottles filled in like manner with lime water; the rirft method produced conftantly the moil. The carbonate of lime formed in thefe different experiments apprized us that 100 parts of the earth contained from 8 to 1 2 of carbonic acid, and fometimes a little lefs in the fiony fpecies. —and water. If this weight of the carbonic acid be deducted from the lofs of weight which this earth fuffers by the calcination in the fire, which was mentioned before, we (hall then have the quantity of water which the earth contains. In collecting the relults of the different experiments, it appears that the earth of BaudiflTero is comuofcd of MagnefJa MAGNESIAN EARTH. 3C2 1 Proportion* tabulated. Magnefia - - 63 Carbonic acid - 12 Silex - 1 5,60 Sulphate of lime - 1 ,60 Water 3 100,20 It is from thefe remits that I denominate this earth native It may be called magnefia. It is doubtlefs found mixed with a little filex; buf |jj* /gjjJSJ, if the title of native alumen is given to the alumenous earth of Halle in Saxony, which contains 24< parts of the fulphate of lime; if the name of native magnefia is given to that of Mo- ravia, announced by Mitchacl, of which 100. parts. contain 50 of carbonic acid; it appears tome that the earth which I de- fence has a much better title to the name which I have given it. The earth of Baudiflero affords a fubject for interefting ob- Suppofed to be fervations in the inveftigation of its origin. Many facts lead decompofition of me to believe that this earth and the Corneen (lone or Cacho- the Corneen long, defcribed and analy fed by my colleague Bonvoifin, are j*one or Cacli»- both of the fame nature. It appears to me that Cacholong at a certain point of its decompofition forms what Bonvoifin calls the hydrophane of Piedmont, and that in its complete decom- pofition it forms the magnetian earth of which I here give the analyfis. Bonvoifin has declared himfelf of an opinion pre- cifely contrary to this ; for he has fuppofed that this earth, far from being the product of the decompofition of Cacholong, is the element of its formation. Our colleague Gioanetti is of the fame opinion. In thefe two hypothefes, the change of one earth into another is manifeir, that is to fay, the change of filex and alumen into magnefia in my method of confider- And therefore ing the matter; (for it is principally of thefe two earths that that either alu- Cacholong and Hydrophane are compofed, from the analyfis -,s changed into of Bonvoifin ;) and the change of magnefia into alumen and magnefia, filex according to the hypothefis of Bonvoifin and Gioanetti. ~^£* e con* As this fubject appears to me to be very interefting, I intend to make a comparative analyfis of thefe Hones at the differ- ent degrees of their decompofition or entering into the ftate of agate (agatifation) which fliall be the fubjedt of another memoir. * 4 Voi. XII.— Supplement. Y , There 32l2 MAONESIAN EARTtf. There remains jet for me to examine the economical ufes for which this earth may be employed. The experiment which I related in the beginning of this memoir, of the decomposition of the fulphate of iron by this earth, wiiich produced an excellent fulphate ©f magnefia, in- dicates one of the methods in which it might be ufed to ad- vantage. Sulphate of mag-.. Twenty-five pounds of fulphate of iron coft only three francs nefia may be ^j, u<. wh\\e the price of the fame weight of fulphate of manufactured r . . . r r . r- n i • from it to ad- magnefia is eight franc?, from this it follows that this procels vantage by the may De followed to advantage. To this may be added that fulphate of iron, tne fulphate of magnefia of commerce, being impure, and defcribed before, mixed with much fulphate of foda, cannot be compared to that thaTof com- *" wrucn mav De procured in this manner, which equals the bed merce in general, fait from * * canal; fo that in this comparifon the more pure fulphate of magnefia thus obtained, may be valued at ten francs at leaft, and in reality is worth more. This however is not the belt method to purfue, wherr the operator has it in his power to follow the others, which I am going to recite. The following experiments make known two procefles much more economical. In the firft experiment I took two pounds of the earth of Baudiflero, reduced to a coarfe powder, with the fame quan-r tity of the fulphuret of iron of Brozo reduced to powder in like manner, I mixed them together carefully, and treated one half in a crucible on the Cue, and the other half in an iron capfule. Or by pounding In both the mixture heated to rednefs emitted fparks, efpe- thefe and heat- cially on being ftirred. It feemed to become reduced to a crucibles; vcrv ^ne powder; a fort of boiling took place, produced doubtlefsly by the difengagement of carbonic acid, and here and there appeared flames of fulpbur, which burned without exhibiting any fign of the production or' a fulphuret. The fulphurous odour was not however very troublefome, from whence it appeared that the magnefia abforbed with readinefs the. fulphuric and fulphurous acids in proportion as they were formed by combuftion. The mixture became of a black- ifh 'zrey, or more properly a black; but which appeared grey frfun the white particles which flill remained mixed with it. After MAGNESIAN £A-ftTH. 323 After being left three hours to coo!, it was moiftened with Leaving to digeft water and put away till next day, a part of it was then lixivi- ^ftenedwith aled ; the folution being made clear and treated with ammo- cold water, nia, gave an abundant and very white precipitate. This cir- Lixmatin£ > cumftance indicating that much of the magnefia was combined with fufphuric acid in the operation, all the remainder was lixiviated. The very clear lixivium, evaporated properly, produced at the firft cryftalization a pound of fulphate of mag- and cryfhruings nefia in beautiful cryftals. The remaining liquor gave on foe- ceffive evaporations a pound and half more of the fame fait in fine cryftals, very dry and very white. The liquor pro- fine cry (his in duced cryftals to the Iaft drop, and the mother-water never j^j"datfce are became foul. The mother- The mixture which remained after lixiviation was roafted watf ; fV3&" , rated lucce ffi veJy a fecond time, and again produced fulphate ot. magneua : It gjves cryftals to was then thrown away, although apparently it would have ths laft droP- • u j r i L < i re «i . c r The refiduurn yielded more fulphate of magnelia after another torrmcation. roaftecj again and In another experiment, pure fulphur was ufed inftead of the re-lixiviaud pyrites ; it was eafy to forefee that the refult would be the f™ more cry" fame; it was however defirable to prove it; and the refult Pure fulphur wa.perfeaiyfctUfeaory. > 'ttm^ The ufe then which may be made of this earth, confifts in iron anfwers forming with it fulphate of magnefia. The means by which J?"*11? ™dI* , this may be done are perhaps the moft fimple poflible. It is phate of mag- fuflicient to reduce to powder the earth and the fulphur, or nefia in the ,aree the fulphuret of iron, where it can be eafily procured, as may nefian earthed be done at EaudiiTero. Thefe fubfiances mould be mixed in pyrites, fimiJar almoft equal parts; for it is ufeful to proceed with an excefst0 e oies°!I,s* of the earth, and the more fo, as its coft is almoft nothing : The mixture mould be terrified in an oven or kiln, heated to the degree at which fulphur inflames, and when there appear no more jets of fiilphurous flames, the kiln is to be left to coot. The matter being then drawn out (hould be moiftened with water in citterns, and left for fome days, only taking care to ftir it in that time. The part of the fulphur which in burning had only paiTed to the ftateof fulphurousacid, oxigenates gradually, or the fait, which at firft was but a fulphite changes to a fulphate. The matter is then to be lixiviated, in the fame manner that is iifed j for nitrous earths, the liquor fufllciently evaporated, and left to cry ft ali ze by cooling. Y 2 Asoihsr 324 MAGNKSIAN EARTH* i^nththtlr e'wf ^no'her method may be followed in places where fulphurets where pyrites are are worked ; or where, as at Brozo, there is a manufacture of burned. fulphate of iron. The kiln, where the pyrites are burned, may be wvereYwkh ^e coverecl ^Hh an heap of the magnefian earth ; the fulphu- a heap of mag- ric acid, which is difengaged will be abforbed by the magne- nerian cart . fa . amj iQ ^ acjvantage of putting an end to the complaints of the owners of property near the manufacture, will be added Which- when that of julphatin pofure to the Its colour becomes by degrees a dull white, the fame as has air, been remarked of the earth of Bau diflero, t0 a dul1 whit« i Its femi-tranfparence is loft; its particles feparate, and in Lofes its femi- two or three weeks it is found to have abforbed carbonic acid tamfparence, t» that degree as to make as marked an eflervefcence with the DOnic acid, fo as acid t0 eftervefe wiu> acids, and be <>:26* MAG&KSIAN earth: com" ^ the . aeid as the eailh of BaudifTero. In a word, it is' completely earth of Baudif r * l J fero, with the the lame as this laft, with this foie difference, that phyfically fmall difference confidered it is lefs compacl. and becomes even friable, and noticed, • , . ,, ,-,,.. . , ■ ,.-, chemically confidered it contains a fitfle more (ilex. It appears then to be well proved that the earth of Bau- ditTero and that of Caftellamonte are each a true native mag- nefia, mixed with a little fii-.v. In the earth of Caftellamonte it is fufficiently demonftrated that it contains no carbonic acid Vvhen in the bofom of the earih; and that it only contains it when, after a long expofure to contact with the air, it can abforb it from the atmofphere. That of BaudifFero contains Earth of Bau» m truth carbonic acid, 'but tiie quantity is much inferior to that differo has not which it ought rceceflari.'y to contain to be confidered a carbo- be' carbonate of nate °^ magnefia ; befides the earth of Baudiffrro having been magne/ia. worked for a longtime, and Befog thus in contact with the air, it is from the atmofphere it mud have drawn it, and tltil in If dug from a proportion to the time it has been expofed ; at leaft I have no fufficient depth doubt that if the earth of Bouciiffero was dug up from a cer- would probably A . . . . . . , , , , ., . . . contain no car- ^in depth, no carbonic acid wowd be found in it. bonic acid. I vvill conclude this addition to the memoir, by obferving lette probably" that the earth of Mufinet at Cafe'ette, being produced by the magnefian a!fo. decompotition of the fame Corneen ftone or Cacholong, ought alfo probably to be a magnefian earth; bat I have not yet made any experiments en this earth ; Doctor Bonvoifin, who has given the analylis of it in its ftate of Cacholong and Hy- The author pro drophane ftone, propofes in conjunction with me to repeat the pofes to analyfe analyfis of this ftone, in the true ftate above-mentioned, and Hytopwf in itsearthy ftale5 vvbich fha11 be the (bbiea of a Particular and write a me- memoir.* moir of the re- * The laft ttfe which Mr. Giobert mentions, for magnefian earth }s of the moft confequence of the two, for as fulphate of magnefia is only ufed in medicine, the fale could not be fufficiently extenfive to produce much profit on a large fcale. The ufe of this earth for pottery is the more deferving of notice, as it has hitherto been fuppofed that argil was alone proper for this purpofe ; and though it was long known that magnefia is of a v«ry refractory nature in the fire, Mr. Giobert feems to be the firlt who thought of ufing it in crucibles ; which is the more extraordinary, as the lapis ollaris, which derives its name from its property of ferv- ing to make utenfils to bear the fire, is well known to contain a large proportion of magnefia. 5 As ARTIFICIAL TAN. , 327 VI. Firft Communication on an artificial Tan prepared fron Coal, chared Wood, refinous Subjlanccs, IfC. Abridged from the Original of Charles Hatchett, Efq. F. R. S.* IR. HATCHETT firft notices, that the natural tannin Firft difcovery was firft extracted from the matters which contain it, by M.Tegu^and Mr. Deyeux, who confidered it as a Ipecies of refin ; tbatDeyeux. Mr. Seguin firft di (covered it to be the fubftanee which in the procefs of tanning renders animal fkins infallible in water, and imputrefcible; but that Mr. Chenevix alone had noticed the effect of heat in giving coffee berries the power in decoction of precipitating gelaten. He then ftates, that Refult of ex- his experiments on lac, and fome of the refms having thewed foi"[-^0fj!£ him the powerful action of nitric acid on fuch fubftances, in- induced others duced him to try its efFed on afplialtum and jet; thefe with °"/S£a1^ it formed a dark brown folution, and a precipitate, which by nitric acid. digcftion in another portion of the acid became diholvec), and on evaporation produced a yellow vifcid fubftanee foluble in water and alcohol, and perfectly fimilar to that obtained by fimilar means from the reiins, excepting that when burned it had the colour of the fat oils. This refult led to the fuppofi- lion, that the dark brown folution was of the carbonaceous As native magnefian earth would doubtlefs be of great uCe to the potteries of this country, it is a pleafing con fi deration, that it is extremely probable it may be found in England, as well as on the Continent ; for not only fteatites and other magnefian ftones have already been difcovered here, but that fait, which it is M. Giobert's principal object to manufacture, is the natural produce of this country, and therefore the neighbourhood of Epfom; which gives it its name, may well be fufpecled of containing beds of an earth fimilar to that of Baudiflero. There is alfo fome reafon to fuppofe, that this earth may be one of thofe ingredients in china-ware, which the Chinde endeavour to keep fecret; indeed it is hardly probable they fliould be ignorant of its ufe, in a country, where the fuieft eaithern-ware. has heen manufactured in the greater! perfection., from period., antecedent to the dates of the authenticated hiftory of Europe, and where of 'courfe experiments relative to the compofition of this article, muit have been varied to the greateft extent. — B. * Ph'iiof. Tranf. 1805. matter 323 artificial Tam. matter, and that the yellow precipitate was the eiTential part of the bitumens, which was confirmed by refults from amber ; Pit-coal treated feveral experiments were tried with various forts of pit-coal, manner, ^rom a'l which the brown folution was obtained in abundance, but thefe which contained little or no bitumen did not yield the yellow precipitate. i Procefs with the Coal. 100 grains of coal, in each experiment, were digefted in an open matrafs in a fand heat, with an ounce of nitric acid (of thefp. gravity of 1.40) diluted with two ounces of water, which when warm produced effervefcence, and discharged much gas; after two days, a fecond, and fometimes a third ounce of the acid was added, and the digeftion continued for five or fix days, when nearly the whole was dilTolved, except the precipitate which was conftantly feparated. and charcoal. Charcoal was next tried, which dilTolved more readily than the pit coal, and left no refiduum. The feveral folutions from afphaltum, jet, pit coal, and charcoal, were evaporated to drynefs gradually to prevent burning the refidue, which from all were of a glofly brown fubiiance, of a refinous fracture, and had the following properties. Properties of the j. They were fpeedily diflblved by cold water, or alcohol. foSnsf thefC 2' Their flavour was aftl inSenL 3. Expofed to heat, they fwelled much, and gave a bulky coal. 4. Their folutions in water reddened litmus paper. 5. And gave copioufly precipitates from muriate of tin, acetite of lead, oxy-fulphate of iron, of a brown colour, except the tin, which was dark grey. 6. They precipated gold in the metallic Hate from its folution. v* 7. They alfo precipitated the nitrates of lime, and of barytes, and other earthy lalts. 8. The fixed alkalis, and ammonia added at firft, deepened their colour, and afterwards made them turbid. 9. They cau fed precipitates from glue or ifinglafs folutions in water, more or lefs brown according to their ftrenglh, whufh were foluble in cold and boiling water, fo that in their eflential ARTIFICIAL TAN. , 3QJJ eflfential properties they proved fimilar to thofe formed 'by the varieties of tannin hitherto known, except that they contained no galtic acid or mucilage. Animal coal from iiinglafs was alfo tried in the fame manner, Refiduumof this diflblved very (lowly, but left a little of the coal ^^^^^ changed, its folution was of a deeper colour, and managed as qualities, nearly, the others defcribed, produced fimilar effects with the re- agents, except fome difference in the colour of the precipi- tates; and alfo gave an infoluble precipitate from the folu- tion of iiinglafs; by which the curious fact is proved, that one portion of the (kin of an animal may be made to convert another into leather. Coak gave a fohition refembling that of pit coal, but did a"d of coak alfo. not produce the fame yellow precipitate. Thefe experiments (hew, that the tanning fubftance is beft Tanning fufa- . r , , . • ; , • , ftance beft pro- procured from carbonaceous matter when it is uncombmed «ured from car- with any fubftance but oxigen ; which was confirmed by h™> uncombined experiments on Bovey coal, SuiTex coal, Surturband from butoxken."* Iceland, and deal faw-duft, which being dilToKed in nitric acid, and evaporated, the refidues diffolved in water, neither precipitated gelalen, or (hewed any other figns of tanning matter; but when the fame materials are charred, and treated as before defcribed, they copioufly produced the artificial tan ; as did alfo teak wood, which Mr. Hatchett had proved to contain neither tannin or gallic acid in its un- chaired itate. Mr. Hatchett had made feveral experiments on the flow Carbonization of carbonization of vegetable matters in the humid way, princi- b^fufphuric* ^ pally by fulphuric acid, occafionally diluted.- Concentrated acid, fulphuric acid poured on any refinous fubftance reduced to powder, diffolves it in a few minutes ; the folution is trans- parent, of a )dlow brown colour, and a vifcid oil-like con- fidence, but after being placed on the fancl bath, grows darker, evolves fulphuric acid gas, and at laft becomes a thick liquid of an intenfe black. Sulphuric acid of the above ftrength poured on common Effects of folu- turpentine dilTolves it readily, if a portion of the folution is t|°" j°n fu]pPb"r';c then dropped into cold water, a precipitate of common yellow acid dropped iu to refin is formed ; if after another hour or two, another portion wateS* is treated in the fame way, the re tin produced is of a dark brown, and that thus formed from a folution that has flood £v« 330 ARTIFICIAL TAN. fwt or fix hours, is completely black. When the digeftion b continued for feveral days, until no more gas is given out, the refin will be converted into a black porous coal, which , without cracking when in the air, have convinced me, that my factitious puzzolona had all the good properties Propofed for ufe of that of Italy, without its faults. At this time I determine in the public e(j to prcp0fe its ufe in the public works, and demanded that comparative experiments mould be made between it a,nd PACTITIOUS rUZZOLANA. 333 the Italian puzzolana, In prefence of the Commiffaries of the and tried cam- Province of Languedoc, and of the Directors of the canal Sec'ommiffariw which joins the two leas. Great blocks of Beton compofi- of Languedoc. tion made with both cements, were thrown into the refervoirs l^ tch^J!0£ adjacent to the lock of Saint Roch, at Caftelmandery, being St. Roch. firft plaiftered over with the respective compofitions Six months after, the water was drawn off from the bodies Its fuperiority of mafonry, and it was then feen that the fa&itious puzza- £r^e Itahaft lona had acquired a folidity at leaft eqaal to that of Italy. The plaifter made with the Italian, puzzalona was cracked and chapped, but that formed from the factitious kind had entirely preferved the unity of its furface. The fiates of Elats of Languedoc altogether convinced of Teftlmony In its the authenticity of this difcovery, by the refults of the com- ftases of Ian' * parative trials of both kinds of cement which they had feen, gueioc, and by the certificates of their commiffaries, and perfuaded of the great advantage it would be to France,, decreed in 1789, in their laft meeting, that the factitious puzzolana fhould not only be ufed inftead of the Italian in the works under their direction ; but moreover, that it fhould be demanded in favour of the author of it, as a teftimony of public gratitude, that government fhould authorize the free circulation of it every where. The great confumption of this factitious puzzolana obliged E* J*jfi*» worhe me to extend its manufacture, I formed a partnership with the proprietor of the ground. The foundation of an eftablifh- ment on a great fcale was laid at the mountain itfelf. where the materials were found. The works carried on". in its vicinity were likely to farther reduce the coft of the article, .which was already one half lefs than that of Italy, and the public were about to enjoy the advantages of this manu- facture, when the revolution paralyfed every thing. • Stopped by the In J 791 I informed the constituent affembly of this dif- ™ol*?n- J . The difcovery covery; the certificates which proved it, and the refults of declared to the the experiments were dtpefited at the office; the matter was constituent af- femb/y* ordered to be examined by M. M. Pelletier aud Berthollet, and the affembly considering, that this factitious puzzolana might be of the greateft ufe to France, decreed that 2000 APF°ved of r ,, , , , , , . - . -i and rewarded, .irancs mould be granted to its author, wmch was paid ac- cording! y. SJ4f FACTITIOUS PVZZOLANi*. On this oceafion the celebrated Mirabeau declared the difcovery to be fo valuable, «• that if it had not yet been made, public encouragement Jhould be held out to excite it." The Conftituent Aflembly wiihed to have numerous fimilar eftabli foments fet on foot in France, fo well were they con- The troubles of vinced of its national importance ; but the misfortunes of the France retards . , ... • ^ . • , , j the manufacture t,mes prevented the execution of a project, which the grand of it. Chief of the empire may eafily realize, to the advantage of the country, whenever it feems good to him to do fo. Refearches on the amelioration of our cements, and parti- cularly on the nature of the materials proper to form artificial puzzolana, led me to try the calcination of various fchifts, of the bitumenous, ferruginous, and argillaceous forts. Examination of The black flatey fchift of M. Bragge, fo common in France, different, fchifts. ^ nQt forgoUen . jf js alffloft ^ fame as l{]at which ftfe elder M. Grathieu effaced at Cherbourg laft year ; but I have Contain too little Con Han tly found that thefe fchifts always contain too little jron^ r puzzo- gj^ j perceived that their repulfion of the water was flow and feeble, and that their folidification in the water was owing to the good quality of the lime. I was thus obliged to recur to my quartzofe oxides of iron, from their containing a greater quantity of ferruginous prin- Puzzolanas owe ciples ; and can aver with the (kilful Faujas, that the puzzo- the'iroaVon- ° 'anas owe tne'r property of hardening in water folely to the toined. ferruginous particles which they contain : of this I have had many proofs. This truth is farther demonftrated in the pud- ding-ftones, the brefcias, and generaHy in all the amygdaloides with a ferruginous bafe or cement. Theory of ce- The theory of our cements is but little advanced ; perhaps BMttOlktkad- we take fi(npie conjcaUres for proofs relative to them. We cried the regeneration of (ilex, and of the carbonate of lime; we know the acid gafes which perform the principal part in the affair : but in this important work we have been long ig- norant of the degrees of their reciprocal affinity, their quan- tity, and the mode of their refpedive combinations. Our knowledge on this matter is confined to a few facts. Two different Many experiments have proved to me that the puzzolana, S^omXm. which 1°onc(1 r°rias a body in the water> is not fit t0 be em* prowed in the open air, where it cracks and chaps in all di- rections. And that which is proper for the air, and which ac- quires FACTITIOUS PUZZOLANA, 335 quires and preferves its tenacity in it, fets but imperfectly m water. This difficulty, of which the Inftitute will perceive the caufe, lias obliged me lo keep two forts of the factitious puzzolana ; on the reciprocal ufe of which a memoir of in- duction will accompany the fa!e. The two forts may be diflinguiflved by their colour. The ■ factitious puzzolana proper for works under water, is One fit for of a reddifh-brown. That which is fit for works expofed to vvater-works. the air, is a dark violet. The latter is ufed for terraces, the Another for ex- embankments of bafons, for the compofition of inclofures, or amj proper fQ*ir* for light roofc. Bridges of a (ingle arch may be formed with terraces, roofs> it; and I have feen it adhere fo ftrongly to glazed tiles, that it was neceifary to break the tiles to detach it. The puzzolana proper for conftructions beneath the water, Water puzzola- forms the rtldft folid body in it. Three months after immer- £p^tfV^ fion it is an actual ftone capable of receiving a polim. The lift, lime in it is always regenerated into carbonate of lime in ten weeks. When it may be thought by any one that he has been de- Nullity of effect reived as to the certainty of thefe effects, it will always be^3ke°^.yth^ found, that he either has not obferved the quantities directed operator, of the puzzolana and the lime, or that he has ufed the reverfe of that kind of the cement proper for the work. I commonly ufed lime in the ftate of impalpable powder, Lime ufed in ^ flacked in Lafaye's manner, for works expofed to the airjpow r Wlt lt* and employed lime in the itate ofpulty, for works which were ar-d In Puttf« to be covered with water. Sometimes I ufed lime in powder for the fame work. This difference depends on the degree of goodnefs of the lime, on its greater or lefTer richnefs, or its proportional poverty. Outturn gives the advantage of know- ing the different kinds on mere infpection. The ufe of lime in powder appeared to me to merit a pre- ference in the preparation of mortars or cements. I prepared my factitious puzzolana in a certain quantity as foon as I knew the proper proportion of the lime; and I had thus the ad- Advantages of vantage of being able to work it in troughs in the fame man- ^liftl^^' ner as fulphate of lime. The whole was well mixed together mixed. and put into facks ; by which means the mafons had nothing to do with the mixture of the articles (which is too often left to unprincipled workmen) ; and being thus matter of the re- • fpective 336 FACTITIOUS PUiZOLANA, fpe&ive proportions of the puzzolana and the lime, I could always be alfared of the folidity of my cements. "Exterior charac- There remains for me to dclcribe the exterior characters of •addes uSw"01* lllC Suarlzi^r°us ferruginous oxides, which form the bafis of my factitious puzzolana, and to relate the analyfis of them winch I made about 18 years ago. I will content myfelf with offering the comparative ref'ults with the Italian puzzolana, both in the dry way and the moid. Exterior Characters of the quartziferous Oxides of Iron. Their colour is of a reddifh-brown before calcination, or Slight caki- Sightly violet. A light torrification gives them a clearer red tint them from brown or a deep violet : one more intenfe renders them of a deep to red. brown or of a violet-brown inclining to a black. The degree ch*m*^*em tc°^llie c*tainati • m crea»e of temp. gree. Between this point and the 42d or 43d, it (utters to about 4a0, fcarcely any perceptible change ; but when heated beyond the and then ex" laft-mentioned degree, it begins to expand, and increafes in ' volume with every fubfequent rife of temperature. During the abftraction of caloric, the peculiarity in the con- and fuffers the ftitution of water equally appears. Warm water, as it cools, "verfe change ftirinks, as other bodies do, till it arrives at the temperature of 43° or 42°. It then fuffers a lofs of two degrees without any alteration of denfity. But when farther cooled, it begins to di- late, and continues to dilate, as the temperature falls, till con- gelation actually commences, whether this occurs as foon as the water reaches the 32°, or after it has defcended any number of degrees below it. Suppofing this peculiarity of water to be eftabliflied, it muft This fdppofed appeal, indeed, a very odd circumftance, that heat fhould pro- Pecull4rlty has duce contraction in this fluid, while it caufes expanfion in other bodies *; and no lefs ftrange, that within one range of tempera- * Is this mode of change peculiar to water ? — I do not know of any experiments with other fluids, except that mentioned on page 343. Perhaps it may be common to all, or at leaft to all thofe which expand by congelation. Decifive trials of this point are thd more defirable, becaufe fome of Count Rumford's general induc*» tions require or fuppofe that feawater mould not be thus affected.:— -N. Z 2 ture 340 CONTRACTION OF WATER BY HEAT, tare it fhould contract, and in another expand, the very fame fubftance. Before a deviation from fo general a law (hould be .received as matter of lacl, the proofs of its exiftence ought to be . ckar and indisputable. been hitherto , The experiments hitherto publifhed, from which this fingula- exJerimentsTn &? lias ^een Placed, have all of them been performed upon narrow nctked water contained in inftruments (haped like a thermometer glafs, veilels, ancj confiding of a ball with a flender ftem ; and the axpanfive or contractive effects of heat and cold have been inferred, from the afcent or defcent of the fluid in the ftem. of which tbe «- To fuch experiments it has been objected, that the dimenftons paaties alfo vary an(j capacity of the inftrument undergo fo much change, from temperature. variation of temperature, that it is difficult, if not impoffible, to determine how much of the apparent anomaly ought to be imputed to fuch changes, and that it is not improbable that the whole of it may be afcribed to them. The author The object of this paper, which I have now the honour jhows the effect {o rea(j to the fQCiety, is to prove by a fet of experiments, ' conducted in a manner altogether different, that the common opinion is founded in Iritfh, and that water prefents itfelf as that ftrange and unaccountable anomaly which I have already defcribed. previous hiftory. It is worth while, before detailing my. experiments, to • . give a fliort account of thofe obfervations which led to the ' difcovery of the fact, and wnich in fucceflion have extended our knowledge of it, as well as of thofe obfervations which . have at different periods been offered to difcredit, and to bring . it into doubt. Dr. Croune firft The fir ft obfervation relative to this fubject was made by obfervedthat D Croune, towards the clofe of the 17th century, while water appears to . ' J expand before it engaged in investigating tire phenomena ot the great and freezes. forcible, though familiar, expanfion which happens to water at the inftant of freezing; a matter which occupied in a confiderable degree, the attention of his fellow-members of the Royal Society of London in the earlier years of that inftitution. Hit narrative. I (hall relate in his own words his firft obfervation : " I filled The experiment a ftrong bolt-head about half-way up the ftem with water, a day watertofe'in a or two before the great froft went off, marking the place where long necked tne vvater flood ; and placing it in the fnow on my leads, veOel by cool- wh;je j went to put fomei faU to the fnow, I found it above CONTRACTION OF WATER BY HEAT. 341 ibe mark fo foon, that I thought the mark had flipt down* which I prefently raifed to the water, and as foon as ever I mixed the fait with the fnow, the water rofe very fad, about one-half inch above it. I took up then the glafs, and found the water all fluid ftill : it was again fet down in the fait and fnow ; but when I came about an hour after to view it, the ball was broke, and the water turned to hard ice, both in the * ball and irera'V From this experiment Dr. Croune drew the conclufion, that Whence he in- water, when fubjected to cold, a&ually began to expand before ^xlliioh^% it began to freeze. On announcing it, however, to the Royal But Dr. Hooke Society, on the 6th of February 1683, Dr. Hooke immediate,y4StodtneVe£ exprefled flrong doubts, and afcribed the afcent of, the water .fel. in the neck of the veflel to the fhrinking of the glafs occafioned by the cold. To obviate this objection, and to preclude, as far as was pof- Dr. C. repeated {ible, the influence of the change of capacity in the aPParatus-^"PV![veiit from an alteration of its temperature, a bolt-head was immerfed in a veflel pre- in a mixture of fait and fnow, and into it, when cooled, was, V10ufly cooled; poured, to a certain height, water previoufly brought to near the freezing point. The water began inftarttjy to rife as before, and when it had afcended about one-fourth of,an. inch in the ftem, the veflel was taken out, the whole water remaining fluid. Thefe experiments, fupported by others of a limilar. nature, which gave fa- ; communicated by Dr. Slare to the Society on the 20th v0'ft"ftf*W*1 the fame month, appear to have fatisfied its members, in ge- neral, of this fact, that water, when on the point of congealing, and while flill fluid, is actually fomewhat dilated previous to the remarkable expanfion which accompanies its converiipn into ice. Dr. Hooke, however, continued unthaken, and retained the but not to Dr. doubts he had exprefled. ■ ■ Hooke' Remarkable as the fact, as now ftated, mull have appeared, it feems not to have excited particular attention, nor to have fo- licited more minute examination; and indeed though phi, lofophers did not lofe fight of it, yet for near a century no one inveftigated it1 more carefully. Mairan, in his treatife on ice in 1719, and Du Creft in lws difleriation on thermo, Birch's Hijiory of the Royal Society, Vol iv,p. 263. meters 34-2 CONTRACTION OF WATER BY HIAT. meters in 1757, appear to be well aware of this property Modem experU of water, but it is to M. De Luc that we owe the knowledge Luc!'° °^ the *eac*mg anc* more interefiing circumftances, (vide Re- cherches, &c. 1772.) Having devoted his attention to the examination and im- provement of the thermometer, he was naturally led to the inveftigation, while engaged in afcertaining the phenomena of the expanfion and contraction of different fluids by heat and cold. He ufed ther- He employed in his experiments thermometer glafles ; and aid^ound^he"' the incIllded water, at or near the term of liquefaction, de- water to defcend fcended in the flem, and appeared to him to fuffer a diminu- ^"Ta^then tioR of bu'k b> every increafe °f temperature, till it arrived rife till freeing: at the 41ft degree. From this point its volume increafed with its temperature, and it afcended in the tube. This fluid, when heated and allowed to cool, feemed to him to contract in the ordinary way, till its temperature funk to the 41°, but to expand and increafe in volume, as the temperature fell to the freezing point. Thedenfity of water, he thence inferred, is at its maximum at 41°, and decreafes with equal certainty whether the tempera- ture is elevated or deprefled. fo that its den- M. de Luc fays, indeed, that very nearly the fame alteration ^2® a° as 'n vo^ume ls occafioned in water of temperature 41 °, by a varia- the fame. tion of any given number of degrees of temperature, whether they be of increafe or of diminution ; and confequently that the denfity of water at temperature 50, and at temperature 32°, is the fame. His theory. This philofopher did not conceive that the constitution of water, in relation to caloric, undergoes a change at the tem- perature of 41°, fuch that (hort of this degree caloric mould occafion contraction, and beyond it expanfion. He imagined that heat in all temperatures tends to produce two but quite oppofite effects on this fluid, the one expanfion, the other contraction. In low temperatures, the contractive effects furpafs the expanfive, and contraction is the confequence : In tempe- ratures beyond 41°, the expanfive predominate, and the -vifible expanfion is the excefs of the expanfive operation over the contractive. In CONTRACTION OF WATER BY HEAT, 343 In 1788, Sir Charles Blagden added the curious obferva- |^"j.B^- tions, that water, which by flow and undifturbed refrigera- wat„ may be lion permits its temperature to fall many degrees beloVv its cooled^many de- freezing point, perfeveres in expanding gradually as the tem-3i? with©„t petature declines ; and that water having fome muriate of freeaing, and foda or fea-falt diflblved in it, begins to expand about the ^ *™t% M w* fame number of degrees above its own term of congelation that the expanfion of pure water precedes its freezing, that is, between eight and nine degrees. More lately, (Philofo- phical Tranfaaiom, 1801), he, or rather Mr. Gilpin by his direction endeavoured to afcertain, by the balance and weigh- ing bottle, the amount of this change of denfity caufed by a few degrees of temperature. Every one mult be familiar with the ufe which Count Rum- Count Rum- ford has made of this peculiarity in the conftitution of water, tions o{ ^-ir in explaining many curious appearances that prefented them- doctrine to the felves in his experiments upon the conducting power of fluids,^"0 y and in accountiug for certain remarkable natural occurrences. The Count, with his ufual ingenuity, has endeavoured to point out the important purpofes which this peculiarity ferves in the economy of nature, and to afiign the final caufe of fo remark- able an exception from a general law. In recording the obfervations and opinions that have been Mr* p*lton*s ,,.n , • • ' .. • \ t • Lf j *• experiments, pubhihed concerning this point, I might now, in order, notice thofe of Mr. Dalton of Manchefter, related in the fifth volume of the Moncheftcr Memoirs, which tended to confirm and enlarge our knowledge of it. But as Mr. Dalton himfelf has called in <{ueftion the accuracy of the conclufion which had been drawn from his experiments, and from thofe of preceding obfervers, I fliall only remark, that they are of the fame nature, and nearly to the fame purport, as thofe of M. de Luc. It was in contequence of a communication with which Mr, w^° 1ueft'oa* Dalton favoured me, three months ago, that my attention was conclufions, directed to this fubjeft, He informed me, that after a long train of experiments he was led to believe that he, and his predeccflbrs in the fame field of invefiigation, had fallen into a mifiake with regard to the contraction of water by heat, and its expanfion by cold, in confequence of overlooking or underrating the effect which the change in the capacity of the ihermometeNfliaped apparatus employed, rnuft occafion on the apparent volume of the fluid. He ftated, in general terras, that S4«i CONTRACTION OF WATER BY HKAT\ bttaufethr that on fubjefting water to different degrees of temperature, Jjpare°ntSdenfity in inftrumerits made of different materials, he found the point is different in of greateft derifity was indicated at a different temperature in different vcffels; • ■ • <-, vir. in earthen- ineaCh- ware at 34», In an apparatus, having a ball of earthen-ware, it was 46%tndlcbadfS at the SUh deSree *» of gldfs at the 42d 5 of brafs at the £o». 46th; and of lead at the 50th. And as water could not follow a different law, according to the nature of the fubftance of the inftrument, he conceived that the appearance of ano- maly in this fluid originated entirely in the containing veflel, which mil ft caufe the fluid in the ftem to fall or rife according as its expanfions are greater or lefs than thofe of the included liquor. A detail of thefe important experiments has, ere now, been tranfmitted for publication in ihejounmh- of the Royal Ivptution of London *. Mr. Dalton I have already noticed that Dr. Hooke endeavoured to ex- Hooke" r* P^am m the fame manner the original experiment of Dr. Croune. This explanation apparently gathers much force from thefe ex- periments of Mr. Dalton. Dc Luc and It is proper, however, to flate, that M. de Luc was perfeclly aware of the alteration in the dimenfions of hisglafs apparatus, but deemed the change loo trifling to have any material in- fluence. Blagdenwere Sir Charles Blagden paid greater attention to the eircum- vcffelT* ° fiance, and by calculation attempted to appreciate what allow- ance ought to be made for the change of capacity in the amount of the apparent changes of volume. When it isconfidered, that the whole amount of the apparent change is but very fmall, and that the expanfibility of the glafs is with difficulty afcertained, and is variable by reafon of the fluctuating proportions of its heterogeneous confthuenls, it muff be acknowledged, thatprecition in fuch a calculation cannot pot- and various rea- fibly be attained,- and can fcarcely be approached. On this ac- fons afford count, all the experiments already noticed are ope'n to the ground for • doubt. 'explanation of Dr. Hooke, and in fome meafure liable to the objection which he had urged. I confefs, that the experiments, of Mr. Dalton, in perfect concurrence with that explanation, * They were tranfmitted to our Journal by the author in Vol. X, psge 93. Created C40 $TR AQ'£IQ:N OF./ W:AsT&R BY H* At. 345 created confiekrirable doubts refpecling the exiftence of the pe- culiarity of water ; agai.nft the probability of which, circum- fiance, .all analogical, reafoning, and every argument a priori, ftrongfy: militate. Unwilling to remain in uncertainty, andconfidering it as a The author'* pojnt'di much euriofity and interetl, I have endeavoured to in- "/re'oo^macle veftigale thefubjecl by experiments conducted in a totally dif- uncertain by the Jerent manner, equally calculated to exhibit the jingular ^^s bcfwrc truth,, but free from the objections tq which the others are liable. In -them, it was my object to provide, that neither the changes of the .actual volume of the water,, nor the alterations in the dimenfions of the inftrument, fhoujd have any influence, whatever. . .,,-..• I have already taken occafion to flater that the purpofe of this, paper is to prove,; by experiments- on the principle now men- tioned, that in the confiitution of w-ater there really exifts the fingularity often noticed. I (hall fir ft fiat e the plan of the experiments, and then detail the pa/ticulars of the moft remarkable of them. When any body is dilated, whether hy heater cold, it necef- His attention farily becomes lefs denfe, or fpecifically lighter ; and the oppofite ^s%v JjS*? effects refult from contraction. This .is the circumftance, as eve- water rifes or ry one knows,. .which caufes various movements among the par- links ty *he tides of fluids, when any inequality of temperature prevails in changes of the mafs;. hence thefe particles are little acquainted with a ftate Feature s of reft. . i . If a partial application or fubtracYion of heat produce an in- equality of denhty in a mafs of fluid, the lighter parts rife to the furface, or the denfe.r fall to the bottom. It readily occurred, that I might avail to my felf of thefe move- ments, and upon ftatical principles determine the queftion in difpute. I had only to examine attentively water, as it was heated or which could be cooled in a jar, and to ©bferve, by means of thermometers, done by ^"r . " »i, , r mometers duly what fituation the warmer, and what the coojer. parts of this pUed. fluid affected. If I ihould find that ice-cold water, in acquiring temperature, fhowed, in its whole progrefs, the warmer parts near the top, it would indicate that water follows the ufual law, and is expand- ed like other bodies by heat. Or if I fhould obferve that warm water, in cooling to the For the cold tracing point, had the coldeft portion uniformly at the bottom, Port'onsof the 34<5 CONTRACTION OP WATER BY HEAT, change of tern perature would the fame conclufiou would follow ; while a different inference, and the exiftence of the fuppofed anomaly, would be deducible the bottom, if fhould the event prove different. The only circumftance, I can denfeft,through. figare i0 myfelf as tending in any meafure to render this mode •ut filch change. ? - • , , , r, . , ot examining the point doubtful, is, that water near its congeal- ing point may have fo little change of denfity occasioned by a fmali variation of temperature, that its particles may be prevent- ed by their inertia, or by the tenacity of the circumfluent mafs, from afiuming that fituation which their fpecific gravity would allot to them. It will appear, however, very clear, from the circumftances of the experiments which I fliall immediately detail, that no obflacle to the fuccefs and precifion of the experiments pro* ceeded from this fource. It is not neceflary for me to relate all the experiments I have made. I fliall reftricl myfelf to the detail of fix, which prefent varieties in the modes of procedure, and which afford the mod ftriking refults. Exp. 1. 1 filled a cylindrical jar of glafs 8f inches deep, and \\ in diameter, with water of temperature 32°, and placed it on Exp. ¥. Ice- cold water ex- Itmofphere, was a table, interpofing a confiderable thicknefs of matter poffeffed warmer |i£) Gf little power of conducting heat. 1 fufpended two thermo* meters in the fluid, nearly in the axis of the jar, one with its ball about half an inch from the bottom, the other at the fame diftance below the furface. The jar was freely expofed to the air of the room, the temperature of which was from 60"* to 62°. The experiment commenced at noon : Top Thermom below till 38' after which it was warmer at top. In. 10 minutes, __30 _50— — an hour, i and 10 minutes, — -. 30 50 — 2 hours and 10 minutes, , _ 30 * i .50 , — 4 hours, 32* 33+ 35.5 37 38 42 44 46 -f 43 50 • 30.5 54 Bottom do, 32° 34-f- 37 38-f 38-f 38.25 40 4T-f 42.5 44 45 49 Confiding CONTRACTION OF WATER IV HEAT* 347* Confiding in the indications of the thermometers, from thit experiment we learn, that when heat flows on all fides from the ambient air into a column of ice-cold water, the warmer por- tions of the fluidaflually defcend, and take pofleffion of the bot- tom of the veflel. This downward courfe proclaims an increafed denfity, and Whence It !s tefiifies that the cold water is contraded by heat. As foon, the ^idet (J^l however, as the fluid at the bottom exhibits a temperature of per) fluid was 38°, this courfe is retarded and foon Hopped, and with the rife "rer at the /, temperatures of temperature beyond 40Q is totally changed; for when the near freezing; mafs attains this degree, the exoeriment equally mows, that the *nd the warmer a • i r 5 J ' • c / u •, < (uPPer) Auid warmer fluid afcends and occupies the lttmmit, by its route an- was rarer ztt^c nouncing its diminiflied denfity, and proving that water is now higher part of* expanded by heat. e cae. Exp. II. I filled the fame jar with water of temperature 53°; and Exp. a. Water that I might obferve the phenomena of cooling, I placed it in *c 53 Tas the axis of a much larger cylindrical veflel, nearly full of water, cooled by enve- of temperature 41°, and, by an earthen-ware fupport, railed it ,0P'"? the veflel about three inches from the bottom, taking care that the water water, it was fhould be on the fame level in both veflels. As foon as I had warmer a* top adjufted the two thermometers, as in the former experiment, I which it was* obferved that the top of the fluid was ftill at 53°, but the bot- warmer (4?-H torn had fallen to 49°. bdow- Top* Bottom. In 9 minutes, 52° - 45 _ ]5 52 - 44 Now, to accelerate the cooling, I withdrew by a fyphon the water from the large cylinder, and fupplied its place by ice-cold water, mixed with fragments of ice, which by repeated cautious agitation was kept uniformly at the tempe- rature of 32°. In 23 minutes, 48° - 42+ — 38 44 - 40 _ 43 42-40 — 46 40 - 40 — 52 36 - 40 — 58 35_ . * 39 -—65 34 - 37 — 75 u_ 34,-36 * * 103 34 - 34 This 34$ contraction of, watjjr by heat, ■Tiiis ex penmen! is the counterpart of tlie foregoing, and fro;n theteftimony of the fame intfrurnents, it appears, that when a. cylinder of water of 53° is cooled by circumfluent iced fluid, the colder part of the water takes pofleflion of the bottom of the. veiTel, foas to eftablifli a difference of temperature from the fur- face, amounting fometimes to 8°-. And that as fop.n as the fluid at the bottom arrives at the 40th degree, the temperature of the . fluid in that fituation. is ifationary till the furface reaches the fame point. Whence the During the fubfequqnt refrigeration, the progrefs of the i^eductdasTn"0001"^ undergoes a total change. The thermometers tell the former ex- that the colder fluid rifes to the furface ; fo that the top gets peiimeut. the ftart of the bottom foon by 4°, and attains the lowed temperature of 34-° very long before the other talis to the fame degree. ■ Thefe circumftances, I think, lead to the conclufion, that by. thelofs of caloric, water at .53° is contracted and rendered fp«» cifically heavier, and that this continues to happen till the water come to the temperature. of 409, at which period an oppofite ef- feci is produced ; for now the water, as it cools, becomes fpecifi- cally lighter, or is expanded. In this, as well as the former experiment, the complete change in the fituation, which the warmer and colder parts of the fluid affected, in the progrefs both of the heating and cooU ing, while every external circumftance of the procefs con- tinued unaltered, is particularly worthy of temarL Exp. 3. A tall Ex/>. Ill.Itookaglafsjar, 17.8 inches deep, and 4.5 in diameter ^V^h'V8 internal meafure, having a neck and tubulature very near the containing water bottom. I provided alfo a cylindrical bafon of tinned ironA at 500, was _ 4, g jncnes deep, and 10 inches in diameter, with a circular upper fart by hole in the middle of the bottom, large enough to receive ice and fait. the top of the jar. By means of a collar and cement I ^refln^mckeftfecured this bafon, fo that it encircled the upper part of the at bottom, till jar. c°nt* u*d fta*- Tne objefl of the contrivance was to have the means of ap* tionary ; after plying a cooling medium to tlie fuperior portion of a cylinder which the fur- Qf water< anci jj anfwered the purpofe completely. I intrd- freezing, and duced the ball of a thermometer through the tubulature, tilt congealed, ^e extremity of it nearly reached the axis at three-fourths oi an inch above the riling of the bottom, and having fixed it in this iiiuation/1 rendered the aperture water-tight, by a per* forated cork and lute. This CONTRACTION OF WATER BY HEAT. This very tall jar was placed on a table, with the Interpol!- tidn of Tome folds of thick paper, in a *oom without a iire, of (he temperature 42°. I filled it with water of 50°, and- poured into the bafon, which embraced the lop, a mixture of powdered ice and fajt. From time to time I explored the temperature near the fur- face, by infertmg the/huib of a thermometer, to the depth of half an inch nearly in the axis. - . '■ .. fiottbrai Trtp. '50°^ 50° 3» One o'clock, In 11 'minutes', ___ 15 • :„2i — i — - — 31 -— — 41 ! — , — 1 hour 6 min. - _ 1 — 2o _^- Au i . 44- — — 4^§ hours, • Air. The experiment tafted 50hotift* — 5| hours, — 1 1 hours at mid jrs, j. e.~\ idnight, J i) |. e. "1 >rning, J 19 noun next morning, 4'5 ■ ***** 4-2 • 41 40- 39.5 49.5 39.5 39 39 39 •* .AS- 44 '42 ' pUihistimeatlrinfilmof 34- \ ice "bega.n to form in €0n- . |_tacl with .the gfafs. 34 f A cruft of ice of fome thick- < nefs now lined the glafs, l^and air had fallen to 40°, Cruft of ice complete. Air 40°. — 26 hours, — 32 40 40 40 41 !Air 40°. So much ice had melted that the cake was de- tached from the (ide of the veffel, and floated. Air 4lc\ Ice not all melted. Air 42°. Ice not entirely gone. This long protracted experiment prefents fome ftriking facts, Review of trie and its general import, with regard to the fubject: of inveftiga- fa^nd r*" tion, agrees with the preceding. In it we fee, that when the frigortfic mixture abftraded caloric from the upper extremity of a cylinder of water, nearly 18 inches long, and at-50p>'lhe re- duction of temperature appeared fooner, and advanced quicker, at its lower extremity than in the axis at the top, not two and a 5 half 350 ,eoNTRACTron or water by heat, half inches diftant from the cooling power. No one car* en- tertain a doubt that this is owing to a current of cooled and con- denfed fluid defcending, and a correfponding one of a warmer temperature afcending. Now, if water obferved the fame law that other bodies do, and had no peculiarity of conftitu- tion, the fame progrefs of cooling (hould continue. This, how- ever, the experiment teaches us, is not the cafe: as foon as the fluid at the bottom exhibits a temperature of 40°, it ceafes. The colder fluid remains at top, and quickly lofing 4s the fluid be- temperature, ere long begins to freeze. The continuance of nuedat top" it" ^e c0^er ^u^ at tr,e furface furely denotes, that it is not *na not denfer more denfe than thefubjacent warmer water. The legitimate thanthatat^' inference from this is, that water of temperature 40° is not contracted by being cooled to 32°. Did water obferve the ufual law, and lofe volume along with temperature, this experiment, by its long duration, afforded ample time for the manifeftation of it. For not lefs than two days did ice-cold water maintain pof- feffion of the top, and for the fame period the temperature at the bottom never fell below 39°. No current, therefore, of cold and condenfed fluid moved from the furface, to affect the inferior thermometer, or to atteft the contraction of water by cold. Yet the experi- This experiment, however, I muft remark, does not warrant rnent does not the conciuflon that the water is actually expanded, though it ihow that it was . g J t b rarer, ln no. degree oppoies it. It proves no more, than that the contraction ceafes at 40° ; and that water of 32° is not more It might be even denfc than of 39° or 40°. Nay, fome may perchance alledge, alledgcd that a that it does not prove fo much ; conceiving, that if at 40° the denfity pre- contraction, without ceafing altogether, becomes very incon- vailedj fiderable, the difference of denfity occafioned by the fubfe- quent reduction of temperature may be fo very trifling, as not to enable the cold particles to take that fituation which their gravity affigns to them, in oppolition to the inertia and tena- city of the fubjacent mafs ; and therefore that the colder, though heavier fluid, may be conftrained to remain above, but this is not That this allegation mould have no weight attached to it, the entitled to re- circum (lances of the fucceeding experiment will clearly iliow, as I (hall foon notice, Thathtatwhich Before quitting the confideration of the prefent experiment, paiTed by dire<3 it m ^ wurLn wnj|e to jemark, that it may feem rather fu.r- communicatioa * * .r pnfing, CONTRACTION OF WATER BY HEAT. $51 prifing, that the bottom of the fluid was not apparently affected rauft have beta in its temperature by the ice which fo long occupied its fur- JJJ^JjL face. It might be expected, though no cold currents de- fended from above, that the caloric (hould be conducted from below, and that the temperature fliould by that have been re- duced *. I fuppofe that the caloric did pafs from the lower ftrata upwards, but extremely flow, by reafon that fluids/ as Count Rum ford taught us, are exceflively bad conductors of heat, and fo very flowly, that the caloric entered from the atmofphere with fufficient quicknefs to prevent any depreffion of temperature below the 39th degree. This experiment, I may conclude with remarking, is very well calculated to exhibit the error of the popular opinion, that " heat has a tendency to afcend." * ANNOTATION, by the Author, f This experiment may perhaps be thought to give counte-The opinion »f nance to the opinion of the very ingenious Count Rumford, c°unJ- Rumf°r* 1- . , ,«.,i. ..i r that fluids can- that fluids cannot conduct heat, and that no interchange ot not condUcT: heat can take place between the particles of bodies in a fluid heat from par- irate, feeing that for two days the fluid at the bottom of thetic,et0 ^^ veflel never fell below 39°, though the furface was at 32°. From the circamftances detailed in his feventh eflay, the Count concluded, that heat cannot defcend in a fluid. From vthe prefent, it might with equal juftice be inferred, that heat cannot afcend. Had I not the fulleft conviction that this celebrated plulofo- appears to beh»~ pher has puthed his ideas too far, I might be difpofed to con- accuracc« tider this experiment as according well with the hypothec's. Soon after the interefting fpeculations of the Count ap- peared, I began to investigate the fubjeel ; and, by a pretty long train of experiments, which I have annually taken an opportunity of detailing in my lectures, fatisfied myfelf that he affigned to fluidity a character that does not belong to it. Though fmce the date of thefe experiments, the public has f As this note fubjoined at the foot of the page after the words temperature Jhould by that have been reduced, in the original, is of fuch considerable length, I have taken the liberty of putting it in die fame type, as the text.— N. become 354 CONTRACTION OT WATER BY HEAT. become poffefled of feveral feries, well devifed, and, in my opinion, of thctrifulves conclufive, it may yet be worth •while to ftate Jthe.tenor and refult of them, by which the value of their *tetlimon:y an favour of the conducting- power of liquids niay be eftimated. Experiments to ■ -The experiments were:of two defcriptiotts. «nWdefcendCin The oncfet> °'f the fame nature »early Wi^ thofe of Count fluids: Rmnford, was deiigned to examine, Whether heat, when applied to the • for face, can defcend.in.a fluid ; and the other ioidifcover, Whether, on the mixture of different portions of fluid at different temperatures, an interchange of caloric takes frlace between the. particles; — Water, oil and mercury, having been the fubjecls of the Count's experiments, were employed for the firft fet. To water (and to To explore the conducting power of water and oil, the communlcaLT3 aPParalus which l ufed confided of two veftels and. tnat water above 40 , by the lofs of heat, or by cold, is rendered fpecifically heavier ; and that water below 40° is, by the fame caufe, rendered fpecifically lighter. Such being the general import, the conclufion is irrefiftible, that heat, in low temperatures, caufes water to contract, and at fuperior temperatures to expand. The opinion, therefore, is founded in truth, that water pofleflfes a peculiarity of con- stitution in relation to the effects of caloric, and that it is, within a fhort range of temperature, an exception to the general law of. " expanfion by heat." Thegreateft So far as lean judge from thefe experiments, lam dif- denfuy Hesbe. rj to j,e]jeve tjlat tjie po;nt at which the change in' the tween 39!'' and r * , 1 1 i- 40?, conftitution of this fluid in relation to heat takes place, lies between 39l°, and the 4.0th degree. I am not at prefent aware of any objection to the method X have followed in eftablifhing this lingular anomaly, and in re- moving any doubts which may have arifen from the unavoid, able influence which the internment muft have in the mode of conducting the inveftigation that had previoufly been adopted. Thefe exneij- The plan of operation above defcribed, however, only af- ments /hew the certains the fact ; it gives no data for ascertaining the amount change, but not °f tne anomalous effect of heat. its amount. j have already ftated, that M. de Luc alledged, that from expanfions and tne temperature of 41°, the expanfion occafioned by colcj contractions be was very nearly equal to that produced by the fame number. ^uatintervals °^ degrees °f ^eat > anc* confequently that water poflelTes the from4o° ? fame denfity at any given number of degrees of temperature above and below 41p. The firft experiments of Mr* Daltorj appeared to confirm this opinion, and to enlarge the range to which it applied, by extending it to temperatures as far below 32°, as water allows itfelf to be cooled before it begins to freeze. From oue circumftance that constantly occurred, I am inclined to think, that the amount of the dilatation by cold is inferior to that caufed by heat. During the heating or cooling of water below 40°, the dif- ference of temperature between the top and bottom of the fluid was lefs than what occurred during the cooling or heat, in§ CONTRACTION OF WATER BY HL^AT. 35$ tng of the fluid through the fame number of degrees above k ; and I conceive that, when other circumftance s, but par- ticularly the rate of the change, are alike, the difference of temperature between the upper and lower parts of the fluid, as it depends upon, may prove a meafure of the difference of denfity. Alcohol, when heated or cooled, prefents, by reafon of its greater expanfibility, a greater difference of temperature in thefe fituations than water; and upon the fame principle I infer, that water from 40° is more expanded by an equal number of degrees of elevation than of depreflion. As the concurrence of the teftimony of the experiments it is a difficult above related with the general opinion, will probably remove problem toex- , , r ^- , r r r> • • plain, how thefe every doubt refpecting the matter of tact, it remains a very contrary changes difficult problem for thofe who are fond of philofophical in- by heat are veftigation, to explain how heat (hall occafion' in the fame fluid, without producing any alteration of mechanical form of chemical condition, at one time contraction and at another expanfion, and to reconcile the contractive effect to the con- ceived notions of the mechanifm of the operations of this .energetic agent. When heat caufes expanfion, it is imagined to act by indue- Tne queftioa ing a repulfion among the particles of bodies, which, oppofing and overpowering the cohefive attraction, caufes the particles io recede. x In what manner, then, the addition of heat can occafion, or allow, the particles of water to approach each other, and how the fubtraction of it can make them retire to a greater diftanGe, I confefs I can in no meafure comprehend. An explanation, abundantly plaufible at firft view, very s*r Charles i'i r r, • r ir i ex Blagden's ex- readily luggefts ltlelt to every one who is aware or the great ptanati0n j viz. and forcible expanfion which happens to this fluid at the moment of its congelation. It it jftated by §ir Charles Blag- den, in the paper already quoted. The remaikable dilatation which water experiences at the As water ex-^ inftant of being converted into ice, is very generally afcribed, by^h-tueof a'"S and I prefume very properly, to a new arrangement which the new arrange- g particles aim me, determined probably by their polarity ; by me"t|° * c which one fide of the particle A is attractive of one fide of B; %yhjle it is repulfive qf another. Now, 3<}0 CONTRACTION OF WATER BY HEAT, it is bable Now, if this polarity operates with fo much energy as t£ that the arrange- impart almoft irrefiftible expanfive force at temperature 3'2°, ment and the jt ;s reafonable to fuppofe that it may begin to exert its in- expanlion may . . ' . . jo begin before fluence, lliough in a far inferior degree, at temperatures lome- foJidity enfues, w}iat more elevated. The expanfion, therefore, that takes place, during the fall of temperature from 40°, may be im- puted to the particles beginning or affecting to aiTume that new arrangement which their polarity afligns them, in which arrangement thefe particles occupy more fpace than before. and the con- Again, when heat caufes water of 32° to contract, upon trary» the fame principle, it may be conceived to operate, by coun- teracting the fmall portion of the difpofition to polarity that furvives the liquefa&ion. I am afiaid that we cannot reft fatistied with this explana* tion. We mud not be deceived by the plaufibility of it. The ftate of perfect fluidity depends upon the circumitanci', /that the particles o( any body admit of ready motion upon each other, and that the change of relative fituation meets with little or no fenfible refiftance. Objection. This Water certainly poflefles fluidity in a great degree, and its advance towards partjcles muft of courfe encounter but little refinance, as they ought to Impair glide the one upon the other. But if thefe particles dial! the fluidity ; begin to exert any degree of polarity, by which certain faces become -more difpofed to attach to each other than certain others, this tendency would neceflarily oppofe that indifference with regard to pofition, which is eiTential to fluidity, and of courfe muft impair the fluidity, and induce fome degree of tenacity or vifcidity. which does not To appearance, however, water at 32° has its fluidity as per- appear to be the fe^ as at temperatures confiderably elevated. Unwilling to trull to appearance, where experiment might decide, I have attempted in various ways to afcertain whether the water fuffers any fenfible diminution in this refpeel while it is expanded by cold. The following method I deem the moft correct, Experiment! For the purpofe, I employed a gravimeter, the one contriv- with Nichols's ecj ^ j^r# Nicholfon for discovering the weight and fpecific gravime e . gravity of folids. This is a convenient inftrument, but, unfortunately, it is by no means fo ticklifh as a balance. Duly loaded, fo as to be equiponderant with the water in which it is plunged, Mr. Nichollbn CONTRACTION OF WATER BY HEAT, 36% Nicholfon fays, It is fenfible to the 20th part of a grain*. The one I have, though its ftem be flender, is fcarcely fenfible to lefs than two or three twentieths of a grain. The want of fenfibility in the gravimeter arifes, in a great meafure, though not entirely, from a certain degree of tenacity fubfifting among the particles of the fluid ; and any thing that tends to increafe this tenacity, muft, in the fame proportion, augment this want of fenfibility. To afcertain whether any fenfible change in the tenacity or it rofe and fell fluidity accompanies the expanfion of water by cold, which the ,nwarm> an* theory requires, I examined the mobility of the'inftrument when immerfed in water at different temperatures. I flrft plunged it into this fluid, heated to between 60° and 70*. Under due loading, which funk it to the mark on the ftem, it was not fenfible to a weight lefs than two or three twen- tieths of a grain, - I then tried it in ice-cold water, and found that its fenfibility in jce-coldwatet was in no perceptible degree impaired. The coldnefs of ihe^jlit^ua water, it muft be remembered, caufes fome degree of contrac- tion of the gravimeter. This contraction cannot fail to render the inftrument in fome fmali meafure more fenfible, and, fo far as it goes, to counteract the fluggiflinefs produced by any in- creased tenacity in the fluid. But as the body of the inftrument is made of glafs, the Whence the amount of the contradion muft be very fmall, and the change £jjj^5£ of fenfibility arifing from it fo very trifling, as certainly by no is not fenfibly r means to obfeure fuch an effect as an increafe of tenacity would chan2ed» occafion. I therefore with fome confidence conclude, that the fluidity of the water is not fenfibly diminifhed, and con- fequently that the polarity has not begun to exert any fenfible influence ; it can fcarcely, therefore, be accounted the caufe of the dilatation. * Perhaps the difference of fenfibility in my inftrument, and that of the learned Profeffur, may have arifen from a difference of the diameters of the ftems. Mine was of one-fortieth of an inch. It was well rubbed with a clean linen cloth, which rendered the furface equally difpofed either to defcend or afcend ; and the in- ftrument was not judged to be in equilibrio with the fluid, except when the furface about the ftem was neither prominent nor de- preffed. This was eafily known hy the reflected image of the window frame, or other objects being ken clofe to the ftem with- out diftortion.— N. h ANNOTATION, £$(52 CeNTRACTION OF WATER BY HEAT. Annotation. — W. N. Sir Charles It does not feem to me that Sir Charles Blagden's explana, Bbgden's theory tjon dow neceflarily imply that the fluidity of the mafs taken of expanfionor , , ft * ./ . ... ... water by heat as a whole, mould be lenfibly impaired when tried by the ap- does not fuppofe plication of a mechanical teft. It might be impaired in the that it fliould be r . _ ° . . V. ,. _ lefs fluid. fame manner as tne wafer is affe&ed by mixing fmall floating fragments of a folid along with it. When a faline folution which would become folid by cold, fuch for example as the fulphate of foda, is cooled below its point of congelation, the cryftals will be differently formed according to circumftances. Inflanee of cry- If the fluid be gently (haken or made to ofcillate, a mower of ftal«Mtion dif- minute cryftals will gradually fall through the fluid ; and the to circumftances. whole mafs will be a confiderable time before the cryftalliza* tion isfinimed; but if, inftead of this method of agitation, the glafs be fcratched by a quill underneath the fluid, in Sir Charles Blagden's way, or if a fmall inftrument, having a cryftal of the fait adhering to it, be dipped into the folution, the cryftals will radiate with great rapidity from that centre of perturbation, and in a few feconds the whole of the folution Whence it is will become rigid. This common and very linking experi- conjeftured that ment 0f chemical lecturers,, feems to me to indicate at leaf! a water by cold pofiibilily that fmall cryftals of ice may be formed and float may arifefrom diftinftly from each other in water, at 40 degrees and lower : 2 ^cVinthe and I think the metals afford us a number of inftances in which £uid, a confiderable interval of temperature is found to be between the commencement of cryftallization and the folidiflcation of the whole mafs. In pewterers folder the interval is not lefs than 40 degrees. This hypothefis of fuch difleminated parti- cles of ice, which feems to be nothing more than an expreflion of Sir Charles Blagden's theory in different words, will explain why the colder water mould be lighter ;— namely, becaufe it muft contain more ice, and alfo why the expanfion ought not to begin but at fome definite temperature. Ameafureof Though it does not appear to me that the theory of Sir the greater or Charles muft neceflarily imply a change in the mechanical re- fcadiefls1sTer0f *iftance of water frora what may be called rlgidity » yet there defuable. are many other reafons why philofophers fliould be delirous of meafuring the variations of fluidity in bodies ; that is to fay, the greater or lefs facility with which their parts are moved Dr. Hope's trial amongft each other. The ingenious attempt of Dr. Hope to may be modified tfCQl&m tfjjs fwm the refiftance made by a fluid to the perfo, ******* ration. CONTRACTION OF WATER BY HEAT. 363 ration oP its furface by a cylindrical folid, is liable to the ob- change in the jection that it fuppofes the attraction or repulfion between the puffion'bctweeii folid and the fluid to remain unchanged by variations of tern- the water and perature; whereas the contrary feems moft probable. The* ^^™^thc doctor's experiment mud be grounded upon a pofition that the greater the depreffion or the greater the elevation of a fluid round a fmall cylinder partly immerfed in it, the greater muft be the fefiftance from imperfect fluidity. But thefe effects are evidently as much governed by'the attraction or repulfion of the folid with regard to the fluid as by the refinance which the experiments are intended to meafure. I have fomewhere read Water clock- that water clocks and other inftruments for meafuring time, flower in cola by the paffage of water through fmall holes, go flower in cold weather; be- wealher. This may arife from contraction of the hole, though i^tfsfru'id*0* my author afcribes it to imperfect fluidity. After fome medi- tation on this problem it (till appears to me to be furrounded with difficulties. Perhaps it may be one of the beft methods to fuffer the fluid to drop from a capillary fyphon in different temperatures. I am difpofed to think that the drops would be Suppofition that" fmalleft and the whole quantity in a given time greateft wnen™ftflterwou!4 1 J ° ° drop from a ca- the fluidity was the mod perfect, or at leaf! when the adhefion pillary tube wheo of the particles of the fluid to each other was the Ieafh But " ^as moft even here the attraction of the fmall capillary extremity of the , tube from which the drop would fall would require to be con-' fidered; and on this account the method would be preferable (if fo) to Dr. Hope's only becaufe the repetition of u great number of drops or quantity of effluent water would give a greater degree of precifion to the refult. Is it likely that the rope pump turned regularly a certain Will the rope number of turns in a given time would raife more water when PU™P fte™ a t 0 . , difference in the coldeft and leaft fluid? If it did not might we not infer that tenacity or flu- the fluidity of water is not fenfibly affected by change of tern- !dity of ***? J J . r hot or cold } perature ? Obfirvations $64? ON 1TRF, IX. Obfa-vahom on Turf, from the German Rathbeger fur alie, Slrend. ^Doctor Collenbvsch, IT is not very probable that a man placed befide a fountain of pure water fiiould fuffer himfelf to die of thirft through neg- lecl of ufing it, or pofTeffing £ood in abundance, mould not appeafehis hunger with it; nevertheless inftances of this kind are not wanting. Wood fuel very Every one complains in Germany of the fcarcity of wood fcaree in Ger- for fuej# jt \s known that fubftances have been found in other Other matter places which can fupply its place, and that they have been may be fubfti- formerly ufed here; but all this cannot induce any one to fearch Mtedforit- for turf. Ungrounded Ifc ls eafily conceived that proprietors of woods, through the prejudices pre- fear of having their profits diminifhed, (hould endeavour to turf for futU perpetuate ancient prejudices, and to extend the opinion that the plague only ceafed its ravages (ince the ufe of turf for fuel has been difcontinued ; but it is difficult to imagine that magif- trates inftead of encouraging the preparation of this fuel, (hould endeavour to prevent thofe from doing (o, who wiflied to en* gage in it. Ufed in Ger- Jfc *s vei7 likely that the difcovery of the ufe of turf as a many from the combufiible was firfl due to chance; and befides the ufe of r?ods,rCm0tC PC" *ms ^ue^ m Germany nas Deen continued from periods more re* mote than any written documents extend to. Various errone- The principal caufes which have prevented the fearch after ou s opinions turft are the erroneous opinions which have been formed of production and *ne manner in which it has been produced, of its preparation, ufe. and its ufe; fome of which are as follow. iftThat turf * Some think, for example, that turf has been formed at the tfmind in veins morqent of the creation, fuch as it is now found in the earth, like metals. arMj that i|iere are veins of turf, as there are of iron, copper, tin, and other metals; but experience proves the falfity of this opinion, for there is found in almofl all parts of Germany turf covered with more or lefs earth, (if only a proper fearch be made for it) beneath which layers of trees may be feen, which proves that Ihcre formerly were forefts in the fame places. Others CN TURF. 365 Others believe that at the time of the deluge vaft forefts were *d That it was , . . . . . , formed at the ' overthrown, and afterwards covered with herbs, reeds, and ^0^p other plants, and that thefe vegetables having rotted by de- grees, became at laft this black combuftible mafs refembling earth, which muft have required an enormous quantity of ve- getables, as plains of many leagues fquare are tound covered with beds of it to the depth of more than 25 feet, beneath which trees are discovered of great hardnefs, and almoft pe- trified. Others imagine that it is more probable that the fea tranfport- 3d ThJt It was ed the materials of the turf from the weftern countries to the ^^^^ eafiern, and covered with them the trees which are found weft, buried beneath the turf. It is very true, that thefe trees have their roots turned towards the wed, and their heads to theeaft. But then it is1 difficult to explain how this fubftance could be carried to countries diftant from the fea, and even to the tops of the higheft mountains in upper Saxony, on the Brocktn and the Alps. Many perfons are of opinion that torrents and rivers have 4th That it ww drawn together and depoftted leaves and branches of trees on wafheddown t% 0 r torrents. the lowr grounds, and that they have thus accumulated the conftituent elements of the turf; but this cannot take place in countries in which no large rivers are found, nor on high mountains. The microfcope clearly mews that turf, efpecially The microfcope that kind which is from the fur face of the earth, is compofed fll^w,s -1' com" poles or veeeta- of mofles, herbs, rufhes, and other vegetables, and their roots ble fibres. ftrongly interlaced, of which the greateft partis changed into earth. Paper has actually been compofed from turf, and the water Papetthade from which has fettled in turbaries is u fed to tan leather, which Ja™^1"*^ proves that it is principally compofed of vegetables. Chemt- water. cal refearches have alfo difcovered in it a mineral refin which principally promotes its combuftibility. It appertains then partly to the vegetable, and partly to the mineral kingdom, Turf may be produced artificially, by digging trenches 6 Turf produced feet deep, and from 15 to 20 feet fquare ; the trenches become Jrt!fi.cia"Y hV . . , ^ unking deep and' filled with water, and produce the nm year a green (limy mofs, wide trenches, the fecond year this molTy vegetation covers the water to the whicn ?!1 UP*T height of two ieQtt and a great quantity of filaments are dif- covered in it mixed with leaves and flowers, in the third year a tfratura is eftabliflied, which attracts the dull and the feeds which $66 *>* turK which float in the air, and engender a quantity of marfh plants, of reeds, and of herbs, which the fourth year become fo heavy that they fall to the bottom. They then become comprefl'ed there, and by fucceflive repetitions of this operation, all the trench becomes filled up in the eourfe of 30 years; however this turf would probably require 100 years before it would equal the ancient turf. Three fpecies of* Although this turf is always the fame in its conftituent parts, lU it neverthelefs differs in having thefe parts varioufly mixed, which occaiions its being divided into three fpecies. The xftThefurface firft comprehends the fit rface turf, and is the moil common tur^ kind ; it is found almoft every where ; but it contains in fome places more combuftible matter, which makes its colour vary. Found wherever This fpecies is always fure to be found wherever places are and Is covered" discovered where the water Magnates, whether on plains, ele- vith weeds, vations, or declivities, in fuch a manner as to form a thick blueifli cruft, and depofits a yellow mud ; or where the foil is covered with mofs, reeds, rufhes, or ridges; and if at the fame time the feet of the paflenger finks into the loofe foil, if and where trees tne earth bends' beneath his feet; if trees are perceived (which covered with are commonly little pines or fir trees, or fometimes other kinds wp-rootedby the °^ trees>) covered with much mofs, inclined to one fide, and -wind. half rooted up at the other by the wind ; in all thefe places turf will be found near the furface, and it is only neceflary to re- move the fod to perceive it. But this operation may be per- formed more quickly and eafily with the Englifti borer, which alfo will (hew the depth of the bed. To procure it To procure the turf, the water thould be drained off, which the waw fliould js eaf., to (j0 jf the country is elevated or has valleys in its vi- be drained oft. ... . . ,.-« , , , ,. . cinity ; but the operation is more difficult when the earth is level. As perfons are not always to be found capable of tak- ing the levels of ground, the places fliould be remarked where the water fettled in fpring when the fnow melts ; thefe places Eafy method of ftypuld be marked by ftakes, and afterwards the trenches fliould Inding the de- be made to pafs this way which are to be dug, to let the water fcent tor the . - .„., „«• drains. ' 'Un off' Method of pre- To cut the turf an iron fpade is ufed, which fliould be nei- pa^ng the fur- ther round nor pointed, but terminating in a ftraight line ; this fho.uld be fcrewed down as far forwards as poflible, along the fide of a ftretched cord, by a line 14 inches long and fix broad j the detached part is feparated from the depth of three inches ON TUIlV. Q&t inches, at two ftrokes of the fpade, to the length of-16'inches, and 4,£ inches broad, and this piece of turf is afterward di- vided in two. In order that the pieces of turf may dry quickly, they mould Method of dry- be placed on planks, and difpofed fo that the air might freely ing lt* circulate between them, and that they could receive the rays of the fun. When the turf is thus dried to a certain degree, it is placed Should not he under (beds to compleat the drying; for if it was expofed to ^n'the'fuxT^ the fun till it was entirely dry, it would lofe its ftrength and burn like (haw. It is alfo difadvantageous to cut a large proviflon of it for or kept too many years, for the lafi made is always the Deft. The upper Upper and lowe- and lower beds are alfo obferved to be of inferior quality to beds of itthc thofe in the midft ; the belt turf is that of a brown colour in-^Jj. £ind d* j. dining to black, is heavy, and its texture is traverfed by a brown and fmall quantity of roots ; trhis kind produces a ftrong and laft ing heavy* fire, and its fmell is very fupportable. The more it is of aBr'ghtbrown or bright brown colour, the greater number of roots in it, and the lighter it is, the worfe is its quality. This fort confumes more fpeedily, and may ferve to advantage where a quick fire is wanted; its odour, it is true, is very difagreeable, but itsathes i are excellent. The turf which inclines to a grey or yellow colour, and 9rey' ™ ye1|?w which is mixed with reed, is always the worft fort, but always good enough to heat kilns or ovens, and itsathes are good; this fpecies is feldom found below the depth of two ells ; it is reproduced after feveral years. The fecond fpecies of turf is the crumbling turf (moder-torf) , Second fpecies, this kind is found more abundantly in Holland; its cutting and ^crumbling preparation require much more pains than the furface turf. The third fpecies, or the mountain turf, is dug up from pits Third fpecies, and galleries, and is reduced to regular forms like the preced- the mountain ing kind. It is objected to the ufe of turf that it cannot be employed Wood not pro- as a fuhftitute for wood in all the places where wood is burned; Pj* for fuel in but it mould not be forgotten that wood itfelf is not fit for every tftan turf, work where fire is required ; that in order to be employed in founderies it mutt be charred with much trouble, and with a Iofs of two thirds of its weight, and that wood as well as turf is of different qualities and produces different effecls. Turf 3 makers in London, Mr. Cuthbertfon, yet I began to fear, even at the outfet, that his fkill would be fet at defiance. The rirft infiruments which he made for the prefent purpofe Condenfing- were, a brafs condenfing-pump, with a lateral fpring forpumP* the admiftion of the gas by means of flop-cock and bladder; two pear-fhaped receivers, one of metal of the capacity of Receivers. feven cubic inches, and another of glafs of about three and a half: thefe were connected by a brafs flop-cock, having a fcrew at each end. The metallic receiver was foon found to Various objec- be of little or no utility, as well on account of its liability to tlons« be acted upon by the generated acids ; its being too capacious, apd thus confuming too large a quantity of gas : as becaufe, though the refult of an experiment might thus be known, yet the changes which the fubjects might undergo would necef? farlly elcape obfervation. The glafs receiver obviated all * " thefe difficulties, and one or two imperfect experiments were performed with it; but the ftop-cock fpeedily failed in its effect. For thepower of the compreffed gafes was fo great, partly from their elafticity, and partly (where affinities had operated) from their corrofive quality, as absolutely to wear a channel in the metal of which the plug was made, and thus r Vol. XII. — Supplement. Bb to 370 AFFINITIES OF COMPRESSED CASES. to effect their efcape. But not to trouble you any further with the obftacles that occurred, and which are mentioned only to prevent unneceflary expence to others, I have at laft, by Mr. Cuthbertfon's afliftance, procured a conne&ing-tube, to which a fpring-valve is adapted that has hitherto anfwered every purpofe. See Plate XIV. Fig. 2, 3, 4, 5, 6. Inftruments The instruments which I now ufe, are, lft. An exhaufling auLUr?d bythetyrmge; 2d- A condenfing-pump, with two lateral fprings for Pump. different gafes ; 3d. The connecting fpring-valve ; and laftly, glafs receivers, which (hould have been of various fizes, but the one mentioned above having burft, that which I have Glafs receiver, principally ufed in the following experiments, is of about five cubic inches and a quarter in capacity, and made of glafs well annealed and a quarter of an inch in thicknefs. Befides thefe infrruments, I have occafionally applied Mr. Cuthbertfon's Syphon gage, double fyphon-gage (See Fig. 6), by which the number of atmofpheres condenfed in the receiver, or rather the elaftic power of the gafes, may be meafured ; but this is rendered of lefs fervice, becaufe a flop-cock muft then be placed be- tween the receiver and fpring-valve, which frequently impairs the whole experiment; and alio becaufe, after a certain de- gree of condenfation, and more particularly upon the admix- ture of the gafes, new affinities ufualfy take place, which tend Eighteen at- to diminish the elaflicity : the greateft number of atmofpheres mofpheres rov gage j^g ^et meafured, is eighteen. Thefe, Sir, with fome bladders and flop-cocks, various iron fcrew-keys, and a wooden' guard for the legs in cafe of burfling, conftitute the principal part of the reqaifite apparatus. I now proceed to the experiments, premifing that the firft four were made with the imperfect apparatus, when the gas was continually making its efcape through the flop-cock. Experiment I. Erp. i. Hldro- Into the glafs receiver, of three cubic inches and a half gen, oxigen, capacity, were comprefled in, the following order : Hidrogen, gave water, and two (wine) pints ; oxigen, two pints ; nitrogen, two pints.* probably nitrous jhe refult was, water which bedewed the iniide of the re- ceiver; white floating vapours (probably the gafeous oxide • • * Thefe gafes therefore occupied about five times the capacity they were condenfed into. — N. of AFFINITIES OF COMPRESSED CASES. 371 of nitrogen) ; and an acid which reddened litmus paper. Mr. Accum was prefent at this experiment, and from his opinion, as well as from fucceeding experiments, I have reafon to think that this acid is the nitric. Experiment II. As a difference of arrangement in the order of the gafes Exp. 2. The tends confiderably to vary (he refult, I repeated the former^^ gUf* experiment (having firft poured a little lime-water into the receiver) by injecting firft the oxigen, about Jhree pints, then equal quantities of hidrogen and nitrogen. Much of this gas efcaped, owing to the imperfection of the inftrument; but upon the affufion of the nitrogen, the white vapours again appeared in the receiver ; water feemed likewife to be formed ; and fome yellow particles were feen floating upon the lime-water. Thefe particles probably arofe from the re- finous fubflance, ufed in fattening on the cap of the receiver, being diflblved by the nitrous gas formed during condenfation. I would juft obferve, that the magnet feemed to be affecled during this experiment; but as there is iron ufed in the ma- chine, this may be otherwife accounted for. Experiment III. Two pints , of Carbonic acid, and two of hidrogen, were Exp. 3. Carbo- fubjeaed to condenfation. The refult was, a watery vapour, ™&* ^water and a gas of rather ofFenfive fmeil. and a changed gas. Experiment IV. Trying to inflame phofphorus by the condenfation of at- Exp. 4. Phof- mofpheVic air, the bottom of the machine (where it had been £°™ j? con* repaired) burft out with an explofion. This happened when I had immerfed the apparatus in water to difcover where the air efcaped. The receiver was full of the fumes of the phof- phorus, which was itfelf difperfed in the veffel of water. I afterwards repeated this experiment with the more perfect apparatus, but I could not inflame the phofphorus, and the fumes which arofe at firft foon difappeared. There was juft enough acid (probably phofphoric) formed on the in fide of the receiver to tinge litmus. B b 2 Experiment 372 AFFINITIES OF COMPRESSED GASES, Experiment V. Exp. 5. Repc- Having now the fpring-valve, and new receiver of five ^n^rxp'I# cubic inches and a half capacity*, I poured in two fcruples paratus. of folution of potafh, and then injected two pints of hidrogen, two of nitrogen, and three of oxigen. This quantity was hardly fufficient for the capacity of the receiver, and the re- fult was only a fmell of the gafeous oxide of nitrogen, a few yellowifh fumes, and fcarce enough acidity to tinge the edge of the left paper : of courfe, I could not effecl the formation of nitrate of pota(h. Experiment VI. Exp. 6. Nitro- I now determined to begin with the nitrogen, which al- gen (firft) and wa«s appeared to me to undergo the moft important chemical then hidrogen . r .,,... rt , . J . and oxigen. changes, and therefore injected two pints of nitrogen, three of oxigen, and two of hidrogen. Upon the condenfation of the nitrogen, it fpeedily aiTumed an orange-red colour, which upon the acceffion of the oxigen, gradually diminilliecl, and at length difappeared, though at firft it feemed rather deeper. A moid vapour, coating the infide of the receiver, arofe upon the compreffion of the hydrogen, which moifture was ftrongly acid to the tafte, coloured litmus, and, when very much di- luted with water, acled upon filver. Experiment. VII. Exp. 7. The Nearly the fame as the laft, but with different arrangement. fame, but diffe- -j;\fc nitrogen, three pints and a half, was firft introduced; rent arrange- , • . . . , Jt . menu ^"e^ tne oxigen, two pints ; and next the oxigen, three and a half. The nitrogen formed the orange-red colour as before ; the hidrogen produced white clouds at firft (quare ammonia ?) which afterwards difappeared, and the orange-red colour be- came lighter; but upon the afTufion of the oxigen, the colour did not difappear as in the laft experiment, but, if any thing, became darker. I then injecled two pints more cf hidrogen, but this had little or no effect upon the colour. Some vapour was generated, which was, as ufual, ftrongly acid. Experiment VIII. Exp. 8. Nitro- Previous to the burfting of the fmall receiver, I had put in gen over lime- it a fcruple of lime, and condenfed upon it three pints o wattr. * One fifth part of a pint very nearly .-^N. nitrogen. AFFINITIES OF COMPRESSED GASES. 373 nitrogen. The refult was, a little reddifh colour at firft, which foon vanifhed. Upon repeating this experiment in the large receiver, I could produce no colour at all. In my pre- fent ftate of knowledge I am unabje to account for this cir- cumftance ; but as foon as I get my new receivers of a fmailer capacity, I mean to repeat the experiment. * Betides the above, I have made various other experiments with different gafes, but I think it right to repeat them with greater accuracy before I fubmit them to the eye of the public : if upon that repetition they appear to me to be attended with refults of fufficient importance to occupy a place in your Journal, I will take the liberty of communicating them to you, and am, Sir, Your raoft obedient fervant, • THO. NORTHMORE. P. S. I think it necefiary to add, that during the courfe of the above-mentioned experiments, there was a great varia- tion of temperature in the atmofphere, from the heat of TO degrees of Fahrenheit to the cold of 33. Explanation of the Figures, by Mr. Cuthbertfon. Fig. 2, 3, 4, 5. Plate XIV. reprefents feclions of the fe- Defcription of a veral parts of the fpring-valve for the condenfing fyringe ; a is ™lv!r for c#n" a female fcrew, intended to receive the male at the end of the fyringe ; b is a fquare, to which is a key to fcrew it per- feftly tight to the fyringe : d, Fig. 3. is a female fcrew fitted to the male c; e is a male fcrew fitted to the female of the glafs receiver ; Fig. 4. is a round Heel arbor, turned with a conical part and flat fhoulder at a; a b is a fpiral fpring; Fig. 5. is a hollow brafs cylinder ferving as a cover and guide to Fig. 4; the piece Fig. 2. has a fmall hole drilled through the center, and turned out at the end c, fo as to fill the cone a, Fig. 4; Fig. 3. is turned out at / fo wide as to receive Fig. 5. If the plane (hank of 4 be put into the hole a c till its cone (hut clofe into the hollow cone ate, Fig. 2. and the other, end with the fpiral, covered by Fig 5. fere wed tight upon the flat end of c, and d be fcrewed to c, all the joints being properly fupplied with oil, and leathers, it is fitted for ufe. Fig. 6. Reprefents a fe&ion of the condenfing or double fyphon gage, being a glafs tnbe bent into the form of the figures, 374 ACCOUNT OF A GRAFHORETER. figures, the end a is mounted with a brafs fcrew, having a hole through it correfponding with the infide of the tube, the leg b c is filled with mercury, and d is hermetically fealed: d c is divided into atmofpheres. XI. Account of a Graphometer for meafuring the Angles of Cryflah - In a Letter from Mr. Robert Bancks, No. 411, Strand. To Mr. NICHOLSON. SIR, Grc3t advantage \ N£ED not ;nt t t nd { {he learned readers ot dittinguilhing r J minerals by their ot your Journal, how great the advantage will be, whenever ngurc. ' the lame may be realized, of difiinguifliing fubjects of the mineral kingdom by their external appearance. This has long been done, with confiderable precifion, by operative men who have acquired their fkill from continued practice, but without being able to communicate the knowledge they poffefs by any fimple indications, fuch as might be given in writing, or through the medium of the prefs. Neither need I on this occafion point out how much we are indebted to the Cryftallography. labours of Bergman, Rome de l'lile, and above all, Haiiy, for fcientific inveftigations of the forms of cryftals, which at prefent bid fair to afford us criterions of the mod extenfive ufe. My prefent object is to communicate what I hope will be thought one ftep, however fmall, towards facilitating the CarangeatTs admeafurement of their angles. In your firft vol. at page 132, cr*ftabTCttr t0t y0Vi ^ave S'ven an account of the graphometer of Carangeau, which is now confiderably known and efteemed. I have rendered that inftrument fomewhat cheaper, and eafier in the execution, and more correct in its ufe. For the fake of thofe who may not have that volume at hand, I (hall briefly ftate, that the inftrument confiiis of a femi-circle, like that which I am about to defcribe, and a pair of compares or legs having their centre in the centre of the femi-circle, but capable of having their points drawn back, fo as to admit of their ap- plication to any fmall cryftals. The arc of the femi-circle is divided ACCOUNT OF A GRAPHOMETER. 375 divided into two quadrants by an hinge, fo that one part may be turned back out of the way of any mineral, which may require to be brought up towards the centre for admeafure- ment; and the fame arc can afterwards be reftored to its place, in order to (hew the degree and fraction of the angle. n my improved inftrument I avoid this joint, and obtain Improved gra» a much firmer framing by making my arc in the form of a femUclrcle s ' protractor, as in Fig. 1. Plate XV. having an hollow centre at entire, and the A, and a ftud at B, both lying in the diredion of that C0.mPaffes or r ^ . . i rp, cr callipers are ufed diameter which terminates the graduations. The compafles, feparately for or radii, or legs, are ftiewn in Fig. 2. fepatate from the arc. meafuring the "n* ^ • . .1 , r r , .. . cryftal, and lneir centre C is made like thole or the common proportional applied to the compafles, and admits of the legs C D, C F being confider- fcmkircle for ably lengthened or (hortened when the two pieces are applied rea ing ° to each other. D E the fixed leg is reprefented as beneath F G the moveable leg or radius, and the lower end of the centre pin is made to fit the hole A precifely, at the fame time that the ftud at B being admitted into the long perfora- tion towards E, the piece D E becomes fteadily attached to the femi-circle, as is feen in Fig. 3. The ufe is obvious. The cryftal mull be meafured by the detached compafles as in Fig. 2, which are much more handy for all defcriptions of minerals than Carangeau's entire in- ftrument; and when thus fet, if fig. 2 be applied to .fig I, "as before directed, the angle will be read of at the fiducial edge of G. I hope you and your readers will confider this as the ufeful (Amplification of a valuable inllrumenf, and fhall be happy to receive your fanclion by its appearing in a work fo generally known and efleemed as your Journal. I am, Sir, Your obedient Servant, >, : . ^ * ROBERT BANCKS. Nov. i, 1805. Accounts $76 NEW BOOKS, ACCOUNT OF NEW BOOKS, Kc. PliUqfopJiical Tranfuclions of the Royal Society of London for 1805. Fort II. Quarto 353 pages, with an Index, and Six Plates. NicoIJ. Tnnfaaio^of ^ HIS Part contains the following communications, 1. the Royal Abftra6t of Obfervations on a Diurnal Variation of the Baro- Society. mster between, the Tropics. By J. Horfburgb, Efq. 2. Concerning the Difference in the Magnetic Needle, on board the Inveftigator, arifing from an Alteration in the Direction of the Ship's Head. By Matthew Flinders, Efq. Commander of his Majefty's Ship, Inveftigator. 3. The Phyfiology of the Stape?, one of the Bones of the Organ of Hearing ; deduced from a comparative View of its Structure, and Ufes in different Animals. By Anthony Carlifle, Efq. F. R. S. 4f On an Artificial Subftance which poflefles the principal Characterise Properties of Tannin. By Charles Halchett, • Efq. F. R. S. 5. The Cafe of a full grown Woman in whom the Ovaria were deficient. By Mr. Charles Pears, F. L. S. 6. A Defcription of Mal-formation in the Heart of an Infant. By Mr. Hugh Chudleigh Standart. 7. On a Method of ana- lyzing Stones containing fixed Alkali, by Means of the Boracic Acid. By Humphry Davy, Efq. F. R. S. 8. On the Direc- tion and Velocity of the Motion of the Sun and Solar Syffem. By William Herfchel, L. L. D. F. R. S. 9. On the re- production of Buds. By Thomas Andrew Knight, Efq. F. R. S. 10. Some Account of Two Mummies of the Egyptian Ibis, one of which was' in a remarkable perfect State. By John Pearfon, Efq. F. R. S. 11. Obfervations on the lingular Figure of the Planet Saturn. By William Herfchel, li. L. D. F. R, S. 12. On the Magnetic At- traction of Oxides of Iron. By Timothy Lane, Efq. F, R. S. 13. Additional Experiments and Remarks on an Artificial Subftance, which poftefles the principal Characteriftic Pro- perties of Tannin. By Charles Hatchett, Efq. F. R. S. 14. On the Difcovery of Palladium, with Obfervations on other Subftances found with Platina. By William Hyde Wollafton, M. D. F. R, S. 15. Experiments on a Mineral Subftance, formerly fuppofed to be Zeolite, with fome Re- marks on Two Species of Uran-glimmer, By the Rev^ William Gregor, 5 Tranfaftion NEW BOOKS, &C* 377 franfaaions of the Royal Society of Edinburgh (being the Com- *™jj£*j°^of iinuation of Fart II. together with Part 111. of the i^A dety of Edin- Volume) Edinburgh Quarto 100 pages Continuation of Part ***&. //, and 126 Pages, Part III. No Plate's^ THE heads of memoirs and communications made to the Society fince their Iaft publication are difquifitions on the origin and radical fenfe of the Greek prepofitions, by Mr* James Bonar, and experiments on the contraction of water by heat, by Dr. Thomas Charles Hope* Thefe two papers of which the latter is inferted in our Supplement, complete the fecond part : and the third part contains the hiflory of the Society confiding of the following articles. 1 . Of the Diurnal Variations of the Barometer, by Mr. Playfair. 2. Aurora Borealis obferved in Day-Light, by the Rev. D. Patrick Graham. 3. Phenomenon of Two Rain-Bows interfering one another, by Mr. Playfair. 4. On the Combuftion of the Diamond, by Sir George Mackenzie, Bart. 5. Remark* on the Bafalts of the Coaft of Antrim, by the Rev. Dr. Riehardfon. 6. Rule for reducing a Square Root by a con- tinued Fra&ion, by James Ivory, Efq. 7. Singular Variety of Hernia, by Mr. Ruflel. 8. Concerning the Chartreufe of Perth, by the Abbe Mann. 9. Explanation of the Old Word Skull or SkoII, by the Rev. Dr. Jamiefon. 10. Bio- graphical Account of the late Dr. James Hulton, by Mr. Playfair. 11. Minutes of the Life and Character of Dr. Jofeph Black, by Dr. Fergufon. 12. Appendix Lift of Members elected fince the Publication of the laft Volume. 13. Lift of Donations. Academical Injlitutions in America. THREE Inftitutions for the promotion of Natural Phy* lofophy and the Arts, having been eftablifhed in the united ilates of America, not many months ago, of which no notice lias hitherto appeared in this work, it is hoped the following account of them will not be unacceptable. The firft is an Academy of the Fine Arts, of which the firft idea is due to Mr. Livingfton : The public were fo fenfible of its importance, that long before the arrival of the Vol. XII. — Supplement. Cc plaifter 378 NEW BOOKS, &C. plaifler of Paris cafts, which he preferred to the infant Society, the number of fubfcribers, at 25 piafters each, amounted to 180. The fecond InSUtution is a Botanic Garden in the neigh- bourhood of New- York ; as yet but a fmall part of -the treafures of the vegetable kingdom are to be feen in it, but the admirers of botany haften to fend to it every interefling plant which is to be found in their vicinity. The charier of incorporation of the fubfcribers, is entirely conformable to the views of the founders of this garden of plants, and ao cording to cufiom, enfures the permanency of the establish- ment : when the hot houfes are finished, it is expected, that the collection of every thing rare and moSt interesting, pro- duced by the fouthern ftates, will be compleated. The third Institution is an agricultural fociety, eftabliShed at Washington, under the fpecial protection of government. The prefident of the United States, who is a moft enlightened agriculturist, the chief men of the administration, the fena- tors, and the deputies of congrefs, are all members of it officially. The fociety being now wealthy from the fums granted by government, and the numerous fubfcriptions of affociates and correfpondents, have purchafed an handfome houfe, and a farm of thirty acres ; they have alfo began a library ; and are in poffeflion of the fine collection of ploughs, and other instruments of Agriculture, which formerly be- longed to general Washington : the form of its administration, the number and the fucceffion of its members, the capital which it may poSTefs (fpecified in buShels of corn) and its: whole organization is regulated by its charter of incorpora- tion; which constitutes this aSTociation a body politic, and fixes the perpetuity of its continuation: It is reported, that ihe anfwers which it returned to the numerous queftions propofed by the focieties of the different States foorw after its establishment, will form a very interefting work Which will foon be published. NEW BOOKS, &C? $^0 Criterion of Life. Pr. STRUVE has contrived an apparatus which is men- Criterion of tioned in the foreign Journals, but not defcribed. The Lif«* pbjeel of its application, is to fhew by means of galvanifm, whether the appearance of death be real; a purpofe fuf* ficiently interefting to every human being, who has for a moment reflected on the fatisfa&ion which recovery from, apparent death muft give to the friends and jelatives of thQ individual fuppofed to be dead | and on the ftill more im- preflive and dreadful incident of recovery after burial. Our galvanic and anatomical philosophers will find no difficulty in applying this powerful agent to fo good a purpofe, in whicl* the learned Doctor has the merit of taking the lead. Mr. SESSKEN who has fuccefsfully laboured in the con- duction of a reflecting telefcope of thirteen feet focus, ha* lately fupplied the Obfervatory at LUienthal, with two mirrors of fifteen feet focus and eleven inches aperture, which prove to be excellent, and bear the magnifying power of 200Q very well, on the proper objects, and at fuch feafons as a,re f]t for making obfervations of this nature. Numbering of Hovfes, A NEW mode of numbering houfes has lately been Numbering of adopted at Paris, which is attended with much advantage, and deferves to be followed in this country. Over each door the numbers are painted in large diftinct characters, and iri confpicuous colours; they 3re generally either brown or red, on a yellow ground, furrounded by a blue fquare ; but the principal iingularity, which is the object of this notice, is, that all the odd numbers are placed at one fide of the Irreet, and the even numbers at the other ; by which means, may be feen at once on entering the ftreet, at which fide of the waj the houfe is, which is fought for; by which much time may be faved, not only by its making it unneceflary ever to crofs the ilreet more thai) once, but alfo by its always preventing \ 380 *KW BOOKS, &C„ preventing the trouble ©f returning back again on the other fide of the ftreet from that already pafled, to find a particular number^ which often happens, where the old method of numbering is ufed, from the order of the numbers proceeding regularly down one fide of the ftreet, and back again in the reverfed direction on the other ; and which, when the ftreets are very long, as many are in this metropolis, is often at- tended with ferious inconvenience ; but in the new method ot numbering, this can never occur, as in it the numbers pro- ceed in the order of progreftipn in the fame direction at both Tides of the ftreet. Index Nicholsons Flulos. Jowrial . Vol.JZT.T IJJV.p. 378. ;' y/rtf/i/j 7UW» \j&i/ &• ■ E X TO) VOL. XII. A. Aberdeen, (m want of a public library, and th« advantages which might be derived from fuch an eftablifhment, 267 Abernethy, 250 Abforption of water rn foils, 85 Achard, M. on a new mode of obtaining fugar from beet-root, 259 Acids, manufactories of, how far pre- judicial to the health of the neighbour- hood, 126 Aeroftation, 298 Air, atmofpheric, new experiments on the refpiration of, 249. — Diminution of in the procefs, 251 Air-pump, on a new conftruttion, 305 Alligator of North America, turbid ftate of, 131 American animal, called Jagiflio, account of, 139 American Indians, on their fuppofed Welch origin, 181. — Improbabilities attending the idea, 187 Analyfis of meteoric ftones, 3. — Of mu- riatic acid, 58 — Of foils, 81.— Of porcelain earth, 277. — Of magnefian «arth of BaudjfleT-o, 320. — Of fac- titious puxzolana, 336 Animal exertion and mechanic power compared, as to their identity, 8 Antoni, 42 Aqua-fortis, diftillation of, 127 Arabic antiquities in Spain, 301 Arcy, Chevalier de, 41 Aftronomical prize, Lalande's, 142 Aftronomy, 297 A ffiburner, Mr. 171 Attraction of deliquefcent falts, table of, . £4* Vox.. XII. • Azote necefiary foT the flow combuftioa of phofphorus, 250. — Experiments to determine how much is abforbed in the procefs of refpiration, 252.— Remarks on its ufes, 253 Bailbet, 52 Balance, variations of, method of re- gulating, 56 Bancks, Mr. R. his inftrument for mea- furing the angles of cryftals, 374 Banff", in want of a public library, 268 Banks, Sir Jofeph, reference to his pam- phlet on the blight in com, 145 Barberry buffi productive of blight in corn, 145.— Doubt whether this dif- eafe affects the grain, 146, 154 Bartholomew's Hofpital, lectures at, 61 Burton, Dr. on the torpid ftate of the North American Alligator, 131 Bartram, Mr. 132, 194 Baudiffero, magnefian earth of, 284, 320 Baume, 278 Beaunier and Gallois, experiments made by, with water blowing machines, 48 Bedford, Duke of, 193 , Beet-root, new method of obtaining fagar from, 259 Bellows applied with the reverberatory furnace in refining iron, 38— Cylin- drical of Namur, 52 Bergman, 105, 374 Bernouilli, Mr. 99 Berthieic's prizes in fortification, 30a Berthollet, 124, 249 Berzelius, on Cerite, 105, 108 Beyer, Mr. 296 k Bile INDEX. Bile, on, 169.— .Former opinions refpect- ing erroneous, ib.— New experiments on, 270 Biot, M. on the formation of water by mere compreflion, 212.— His exten- iions of the theorems in the horologium of Huygens, 296 Blagden, Sir Charles, 29. — On the ex- panfion of water, 343,' 359, 362 Blafting Rocks, improved mode of, 41, 60.— panger of the old method, 61.— Farther obfervations, 171 Blight in corn, 145, 149. — Frequently miftaken for fhri veiled grain premature- ly reaped, 153 Bohemian Society, 34 Bonvoifin, on the Carneen ftone, or Ca- cholong, 321 Books, new, 376 Boflu, 131 Botanic Garden at Copenhagen, 299"" Boukon and Watts, 174 Bbunet, 39 Brale, Mr. 124 Bralle, Mr. his new procefs for fteeping hemp, 61 Breweries, 124 Brauer, Mr. his drawings of the difeafes. in corn, 146 Brugnatelli, 275 BufFon, 114, 120 Bulbous roots, compofition of foils pioper for, 95. — Blown in water, 308 Bunda Language, dictionary of, 301 Butter, procefs of making, 219.— Purifi- cation of by fufion, 2J9 Cadet, on the deliquefcence and Ef- florescence of falts, 240 Canova's fculptural exertions, 301 Carangeau's graphometer for cryftals, 374 Carbon, gafeous oxide of, experiments on tnCTelpiration of, 254 Carbonate of potafh, on the formation of, *74 Carbonic acid, quantity produced in ref- piration, 254 Cafeletta, earth of, 326 Caftellmonte, earth of, 324 Catgut manufactories prejudicial to the , health of the neighbourhood, 125 Celtic words difcoverable in the American dialects, 191 Cerite, experiments on, 105 Cerufe, pure and beautiful, 143 Chaptal, on manufactories injurious to health, 122.— Reference to his che- miftr7> 338 Charkow, Univerfity of, 29S Charts printed by moveable types, 300 Chenevix, Mr. on artificial tan. 327 Childs, Mr. his communication re- flecting the Welch origin of a tribe in North America, 183 Chimney, draft of, increafed by Steam, a Chinefe fire works, 273 Chromate of lead and fiiver,. diffolved in nitric acid, 144 Circle, divifion of an arch of, 226 Clapham Church, defcriptJon of the frame-work by which the roof was railed, 176 Claproth, fee Klaproth Clegg, Mr. his portable fteam- engine, 174 Clofe, Mr. W. his apparatus for raifing water, 16.— On blafting rocks, 17! Cobalt, pure, method of obtaining it, 258 Collenbufch, Dr. on Turf, 364 Colour manufactories, 124 Colour for marking the heads of pieces of cotton or linen in the rough, 206 Colours, abftract of a memoir on, 112. — Theory of, imperfect, 121 Compafs for taking bearings in a chart, 224 Conducting power of fluids, obfervations and experiments on, 133 Cooling, experiments on, 70 Copenhagen, botanic garden at, 299 Corn, difeafes of, 145, — Country names •f, 147 Cornecn Corneen Stone, or cacholong, 32 1 Correfpondent, a, on the ftate of pro- vincial, fcientific and literary focieties, Croiine, Dr. his difcovery of the expan- fion of water prior to freezing, 340 Crow, an American, Anecdotes of, 194 Cruickfhank, Dr. 59 Cumberland, G. Efq. on the difeafes of corn, 145. — On a project for extend- ing roads on an inclined plane, 266 Curaudeau, M. 374 Curriers' fpent oil, 220 Curwen, Mr. on draining lands, 177 Cuthbertfon's improved air-pump, 306, 369 Dalton, Mr. on Count Rumford's ex- periment relating to the denficy of water, 23.— -Remarks on, 180. — Experiments on fluids, 134, 343 Davy, H. Efq. on the analyfis of foils, 81. — On nitrous oxide, 249, 255 Decamdra, Mr. 35 Delauny, Mr. 303 Defcotils on the decompcfition of fulphate of lead by muriatic acid, 221 Devon iron-works, 55 Deyeux's difcovery of artificial tan, 327 Difpatches, propofed method for expedi- tious conveyance of, 266 Dodun, M. on factitious puzzolana, 331 Draft of a chimney uicreafed by the ad- mi fTion of fteam, 2 Draining land, experiments on, 177 Du Hamel, 233. — On the fap of trees, 309, &c. Dundonald, Lord, on the analyfis of foils, Si Dye-houfes, 125 INDEX. Electrical machines, improvement inj 103 Electrical conductors, 297 . E, Elecampaine r0ot, experiments on, 97 Electric fpark, may confift of light driven " from comprefied air, 214 Elkington, Mr. objection! to his mode of making drains, 177 Enquirer, an, on initances of wafteful negligence in certain northern fifheries, 269 Excitability of the parts of animals by- gal vanifm, 100 F. A, his account of thermometers for registering temperatures in the abfence of the obferver, 215 Faujas, on the eruptions of ancient voir canoes, 331 Fire-arms, on the initial velocity of pro- jectiles difcharged from, 41 Fire- works unknown in Europe, def- criptioh of, 273 Fifher, Mr. his improved method of blafting rocks, 172 Fluids, conducting power of, 133 Fogget, M. on blafting rocks, 60 Force, power, rife and application of the terms, 8.— Definition of, 9 Fortification, prizes in, given by the French minifter of war, 300 Fofter, Dr. 131 Fothergil, 250 Franklin, Dr. 297 Froft, perpetual, prevalent in the aby-fies of the ocean, 22,0 Fryer, Mr. Michael, 225 G. Gallois, fee Beaunier. Galvanifm, 59.— New difcoveries in, 99 Gafeous oxide of carbon, fee carbon Gafes, comprefied, affinities of, 368 Geneva, Lake of, fudden and irregular fall of, 198.— Explanations by various authors, »co,~ Singular appearance of, b * ac* INDEX. T02.— Objections to the theories quoted 203.— Another theory offered, 204 Geographical dictionary of Ruflia, 303 Geography, 297 Geometry, 296 Giddy, Davies, Efq. M. P, on the in- vifiWe cmiffion of fleam and fmoke, 1. Remarks on, by W. N. 47 Giefecke,s propofed expedition to Green- land, 299 Gilding on metals, detrimental to the health of the workmen, 127 Gilpin, Mr. his experiments on the ex- pansion of water, 343 Giounetti, Dr. 277 Giobert on the magnefian earth of Baudif- fero, 277, 284, 320, &c. Goener, 301 Goodwin, 250 Gough, John, Efq. on the divifion of an arch of a circle, 225 Graham, Mr. 132 Graphometer for meafurir.g the angles of cryftals, 374 Gravity, weight and heavinefs terms admitting of diftinction, 14 Greek words found in the American dia- lects, 191 Greenland, propofed mineralogical ex- pedition to, 299 Gregory, Mr. O. on mechanic power, in reply to Mr. Hornblower, 7 Griffith, Maurice, his relation refpecYmg the Welch American Indians, 183.— Obfervations on, 187 Grobert, colonel, his machine for mea- furing projectiles, 42, 45 Gums arabic and adracanth, experiments on, 256 Guyton, Morveau, on manufactories in- jurious to health, 122 H. Halter, Mr. 303 Harding, Mr* obtaining the aftionomical prize of Lelande, 142.— Hi* newly difcovered ftar, 288 Haffenfratz, J. H. on the act of bending wood, 30 Hatchett, Mr. on artificial tan, 327 Hauffman's experiments to afcertain the be ft colour for marking pieces of cotton or linen, 206 Hauy, 374 Heat, inveftigations rrfpecting, 65, 72, 54. — Apparatus for tranfmitting down- wards through fluids, 136 Heavinefs, fee Gravity. Hedwig, 239 Hemp, new procefs of fteeping, 61.—* Its manufacture injurious to health, &c. 124 Herfchel, Dr. his experiments on tele« fcopes, 285. — Obfervations on Mr. Harding's newly difcovered planet Juno, 289 Heringer on cerite, 105, 108, no) Hoodlefs, Mr. 179 Hooke, Dr. on the expanfion of water, Hope, Dr. on the denfity of Water, 18a —On the contraction of water by heat, 339* 36* Horn> Mr. 61 Hornblower, Mr. J. C. reply to his re- marks on mechanic power, by M. Gre- gory, 7. — His defcription of the framed work by which the roof of Clapham church was raifed, 176 Howard, Mr. on meteoric ftones, 3 Humboldt, on the longitude of Mexico, 297 Hutton, Dr. on the velocity of pro» jecticles, 42 Huygens^ theorems extended, 296 Hydraulic machine, by Mr. Clofe, def- cription of, 16 I. Identity of animal exertion and mechanic power, 8 Jndoftanj INDEX Indoftan, fmgular method of conftrucl- ing walls and roofs there, 313 Inftruments requifite for the analyfis of foils, 83 Invernefs, advantages which would refult from the eftablifhment of a public library there, 268 Invifible emiflion of fleam and fmoke, 147 Iron, caft and malleable, experiments on, 34 Izarn, Dr. 3 J- Jackfon, Rev. Mr. 246 Jagifho, an American animal of former times, account of, 139 Jefferfon, Mr. 141 Jeflop, Mr. on blading rocks, 60 J. P. on light as a body, 104 Juno, the planet, obfervations on the nature and magnitude of, 289 K. Kirwan, Mr. on the Analyfis of foils, 81 Klaproth on falfe tungftein or cerite, 305 —His death, 142 Knight, Andrew, Efq. on the fhte in which the true fap of trees is depofited during winter, 240, 308 Kcelifon, a new muficat instrument, 142 Kotzebue on the ancient MSS. found at Portici, 303 L. Lalande's agronomical prize, 142 Lampadius, G. A. on the difference be- tween caft and malleable iron, 34 Languages, elements of, 8 Lavoifier, 250 Lawfon, Mr. 132 Lead, fulphate of, on Its decomposition by muriatic acid, 221 Leather, compounds ufed in dreffing, 120 Legoux de Flaix, on the baked walls and roofs of rural buildings in lndoftan> 3X3 Leipfic fair, 30a Leverian Mufeum, to be fold, 244 Lewis, Dr. on water-blowing machines, 48 Light may be as ftrongly reflected by a rough furface as by a fmooth one, 74. — Queftion refpe&ing, 104. — • Experiments on, 166 Linen, &c. compound for marking, 207 Linnaeus, 131 Literary and Philofophical Society at New- castle upon Tyne, twelfth report, 60 Luc, M. de, his experiments on the ex- panfion of water, 342 Luminous bottle, method of preparing, 276 M. Mc Gilivray, Mr. 190 Macquer, 277 Madac, or Madog, the "Wtelch prince, on his fuppofed emigration to America* i83 Magiftrates, caution to, 128 Magnefian earth of BaudifTero, 284, 320 Manufactories, from which a difagreeable fmcll arifes, folution of a question con- cerning, 122 Marking linen, &c. compofition for, 207 Mafloufky's new mufical inftrument, 142 Mathey's machine for meafuring pro- jectiles, 42 Maufoleum of the Arch-Duchefs, Chrif- tiana, 301 Mechain, on the occultation of it fco/pio, 297 Mechanic powers, on, 7 Medical inftitution, 62 Menzies, 250 Metallic veflels, 72 Metals lofe not their power of reflecting with their polifh, 74 Meteoric ftones, on, 2.— Analyfis of, 3, &c. INDEX. &c.— New hypothefis refpe&ing their origin, 6 Meuimer, General, T15 Mexico, tongituue of, accurately determin- ed, 297 Mildew In corn, 147.— Docs not arife from an external caufe, 148 Milk, memoir on, by M. Thcnard, 2 18 Mineral preparations, how far pernicious to the health of thofe employed, and to the neighbourhood, IZ7 Mineralogical expedition to Greenland propofed, 299 Molard, 124 Monge, 224 M„->m, Van, information by, refpeeting cerufe, 143. — On the prevention of putrefaction, 144 Morning Chionicle, extract from, giving an account of the eruption of Vefuvius, 222 Mud walls of Indoftan, 313 Muriatic acid, compofition of, 58 Murray's experiments on fluids, 134 M.ufquet barrels burft by a charge of gun- powder confined by fand, 40 Mufical inftrument, new, 142 N. Namur, cylindrical bellows of, 52 Napion, 277 Newton, Sir Ifaac, 7, 112 Niccolanum, fee Nickeline Nicholfon's experiments on fluids, 134, Nickel, on, 75. — Malleable and magnetic, 77, 78. — External charter, ib. — Specific gravity, ib, — A ncble metal, 78, 80. — Its magnetic property weak- ened by copper, and destroyed by arfenic, 79.— Action of acids on, ib.— Beft mode of forcing from iron, ib.— Oxide of, 80.-— Precipitates, ib. , Nickeline, a newly difcovered metal, 261. •—Experiments on, ib. Noithmore, Mr. T. on the effects . take place in gaics, when compielTed, 36S Oakley, Mr. 149 Occultation of the pleiades by the moon* of it fcorpio, and of the comet in 1793, 297 O.bers, Dr< 293 Oughtred, 225 Oxigen and hydrogen may unite by pref- fure, 212 Oxigen gas more productive of carbonic acid, in refpiration, than atmofpheric air, 254 Pacchioni, Dr. on the compofition of muriatic acid, 58 Pallas, Dr. 133 Pape, the Rev. D. his improvement of Rye Harbour, 245 Paper manufactories, 124 Peele, Mr. on muriatic acid, 59 Pelletier's apparatus for obtaining car- bonate of potafh, 274 Pennant, Mr. extract of a letter from relative to the non-exiftence of Welch Indians in America, 190 Peterhead, in want of a public library, 268 Pfaff, Profeflbr, his new experiments on refpiration, 249 Piazzi, Mr. 293 Pictet on the occultation of the pleiade* by the moon, 297 Pignotti, Sig. Lorenzo, 58 Piracy of books puniihed, 301 Piron, Mr. on the temperature of the fesr, 220 Plowman, T. Efq. his improved Sheep- fold, 191 P. M's quotation of a defcription of fire- woiks unknown in Europe, 273 Porcelain INDEX. Porcelain earth, analyfis of, 277 , Portici, ancient manufcripts difcovered at, ,303 Poucrette manufactories, 125 f oullaouen iron works, 48 Poufehkin, Cou.nt, on the folution of chromate of lead and filver, 144 PowjI, David, his account of the emigra- tion of the Welch, under their prince Madoc, 18S Power, mechanic, on, 7.— Indentified with animal exertion, 8.— pRife, ap- plication, and definition of the term, ib. Prieur, memoir by, on colours, 112 Prince's improvement in the air-pump, 306 Projectiles, method of meafuring the initial velocity of, 41 Prony, M. 10 — His method of meafur- ing the initial velocity of projectiles difcharged from fire-arms, 41 Provincial focieties for fcientific and literary improvements, ftate of, 267 Prouft ProfefTor, on the meteoric ilone of Sigena, 2 Pruffian blue manufactories not pre- judicial to the health, 128 Putrefaction, animal, pernicious in pro- portion to its humidity, 125.— Pre- vented, 144 PuazoIanaf factitious, 331 Radiation of heat, 74 Rail roads, 266 Reaping, on, 153 Refpiration, chemical refearchcs concern- ing, and fliort hiftoryof, 249.— New ex- periments on, 250 Refleftion of heat by policed and blacken- ed bodies, 66 Reverberatory furnace for experiments on caft and malleable iron defcribed, 34 Rkhman, ProfefTor, 297 Richter, Dr. J. B. on pure nickel, 75— On a metal much refembling nickel, 261 Rilter, Mr. on galvanifm, 99.-— Biogra- • phical notice of, 101, 10a Roads on an inclined plane, project for, 266 Pvobertfoa, Dr. 188.— His balloon, 298 Robins, Mr. Benj. 41 Robinfon ProfefTor, 7. — Correction of a mi (take in 12. — Diftinction between gravity, weight, and heaviness, 14 Rocks, Mr. JefTop's improved mode of blaftmg, 60 Roebuck, Mr. on water-blowing ma- chines, 55 Rome de rifle, 374 Rofe, Mr* on the difcovery of a new vegetable fubftance, 97 Rumfbrd, Count, remarks on his ex- periments on the denfity of water, 28. — On the velocity of projectiles, 41. — On heat, 65, 154.— On coloured fhadows, 114. — His opinion on the non-conducting power of fluids con- troverted, 133.— On the expanfion of water by beat, 343, 351 . Ruffian marine inftitution, 302.—Efla- blifhments for Education, 302.— Geo- graphical dictionary, 303 Ruft in corn, 149. — Prevented by fteep- ing* ib. Rye Harbour, account of tfoe means ufed to make it navigable for mips of confiderable burthen, 245 S. Sal-ammoniac manufactories not In- jurious to health, 128 Salt of the fea, origin of, 59 fpirit of, manufacture of, not in- jurious to the health of the neighbour- hood, 127 Salts, deliquefcence and efflerefcence of, 240. — Experiments, 241.— Remark- able facts, 244 4 Salts INDEX. Safr*, deliquefeent, table of, In the order of their attraction, 242 Sand, an ufeful afiiilaut to gun-powder in biafting rocks, &c. 41, 60, 171 Sap of trees during winter, 233, 308.— Experiments on, 234 Saverein the engineer, notice of his death, »43 Saw-makers, their method of hardening fteel, 63 Scientific News ; for Auguft, 58. — For September, 142. — For Qdtober, 220. —For November, 296 Sea, temperature of, 220. — At great depths eternally frozen, ib. Seguin, 250. — Q» the oil ufed by Cur- riers, 220 Sheepfold, improved, 192.— Advantages of, ib.— Method of placing on hilly grounds, 193 Sigena, account of a meteoric (lone, which fell there, 2 Silliman, Benj. Efq. 305 Singer, Mr. on an improved mode of ap- plying the points in eleclrical machines, 103 '. Six's Thermometer, objections tc it, 216 Slaughter houfes, 125 ' - Smeaton, Mr. 10, 13 ) •« Smut in corn, 148 < Soils, analyfis of, 81. — Subftances found in, ib. — Inftr '.ments requifite for, 83, 96. — Mode of Hefting, 83. — Afcer- taining their fpecific gravity, 84. — Phyfical prOperti:s, ib. — Quantity of water abforbed by, 85. — Separation of extraneous matters from, 85, 86. — Examination of 86, &c— Products, 91. — Simplification of the analyfis, 92.— Improvement of, 93. — Difference of under different climates, 94. — Com- pofition of, ib. — Rendered fertile by changing the composition of the earthy parts, 96 Sonini's Journal, extract from, 276 Springs, method of making, 63 Starch, a powder refembling, obtained from elecampane root, 97. — Manufac- tories, J24 Starck, N. D. Efq. his compafles for taking bearings in a chart defcribed, 224 Staunton, Srr G. his embaffy to China, extract from the account of, 273 Steam applied to afilft the refining of iron, 37. — Its invifible emifiion into the air, »> 47 Steam-engine applied to carriages, 1. — A portable one, 174.— Improvement* in, 294, 316 Steel, blued, properties of, 63 Steeping hemp, 61. — Grain to prevent fmut, 149 Sceinacher, M. on carbonate of potafh, *74 Steward, Profeffor, 8 Stones, meteoric, on, 2. — Shower of, 3. — Analyfis of, 3, &c. — New hypo- thecs refpedting their origin, 6 Straw, obfervations made on difeafed, 151 Succulent plants, prefervation of, 64 Sugar, new mode of obtaining from beet- root, 259 Sulphate of lead, fee lead Sulphuric acid, manufactories of, 126 Syphon, inverted, Mr. Clofe's method of xaifing water by means of, |6 T. Tan, artificial, prep^d from coal, djc. 3*7 Taffaert, M. 105 Telefcopes, experiments for afcertaining how they enable the fpedator to dif- tinguifk the real diameter of objects, 285 Teffier, 124 Theatre in the Crimea, 302 Thenard, M. on milk and butter, 218. —On bile, 269 Thermometers for regiftering temperatures in the abfencc of the obferver, 215 Thomas INDEX. Thomas de Thomon, 302 Thomson's experiments on Fluids, 134. 239 Thornhill, Mr. 61 T. I. B. on the maximum denfity of water, i3o Toulmin, Mr. oh the &Ppofcd Welch tribe of American Indians, 1S1 {Trades, objectionable, on account of their pernicious quali ies, 123 Trail, Dr* on the conducting power of fluids, 133 Traveller, a, on the ftate of provincial focieties for fcientific and literary im- provement j 267 Trees, on the ftate in which their fap is depefiteri during winder, 233 Trevithick's fteam-engines, 1 Tromfdorf, M. on obtaining pure cobalt, 258 Trufler, Dr. on heavinefs and weight, Tungftein, falfe, 105 Turf, obfervations on, 364 V. Valli, Dr. on the prevention of putrefac- tion., 144 Vapour, aqueous, applied to the refining of iron, 37 Varnifh capable of refilling the actions of acids en metals, procefs for making, 207 Vaucher, M. on the feiches of the lake of Geneva, 198 Vauquelin on cerite, 105, ic8.— On gum-arabic and adracanth, 256 Vefuvius, eruption of, 222 Vegetable fubftance, a new, 97 Vibrations of a balance, on the, 56 Vieta, 225 Vinegar manufactories, 127 Von Einfiedcl, 35 W. Wagener's invention for printing charts, Wajlis, 225 THE END OF THf Printed by W, Stratford, Water, apparatus for raifmg, by rhearis c?~ condeufed air, 16.— Reiuatkson Count Rumford's experiments on the denfity of, 28, 180, 339. — How far ufsful in refining of iron, 37 Abforption of in fails, 85. — A bad conductor of heat, 1 62. — Effect produced on by air blown from the human lungs, at tiie depth of fcveral feet below the furface, 206.-— Formation of by comprefiion, 21a Water-blowing machines, 48. -—Experi- ments with 50. — General conclusions, 54 Water-clocks, 363 Water colours, experiment* in, 208 Weight and heavinefs, not fynoniraous terms, 14 Welch Indians of North America, ob- fervations and conjectures relative to, 181 Welter's apparatus for obtaining carbonate of potalh too complicated, 274 White colour, new definicion of, n Williams, Dr. 190 W. N. on the burfting of mufquet bar- rels by a charge of gun powder con- fined with find, 40. — On the invifible emirlion of fleam into the air, 47.— On vater- blowing machines, 54. — On, t* .eiches of the Lake of Geneva, 203. — In anfwer to F. A. on improved thermometers, 217. — On the contrac- • ticn of water by hear, 362 Wood, on the art of hendi'iP?, 30 felled in autumn or winter more firm than when fuffered to ftand till fpring or fummer: correction of the general opinion as to the caufc, 233 Woolf, Mr. his improvements in fleam- engines, 294, 316 Wright Elizur, his newly conflructed, air pump, 305 Wyatt, Mr. Samuel, 338 Y. Young, Mr. Charles, on the vibration* of a balance, 56.— On the analyfis 'of foils, 81 TWELFTH VOLUME. Crown-Court, Templs-Bar,