\\V1P wm mf. R. i ilSM Aty D?J©ror ]R©]BI ,§ON,Ify.^JfaT.PmZ.]&JD>l.-NMTmGIL THE PHILOSOPHICAL MAGAZINE: . COMPREHENDING THE VARIOUS BRANCHES OF SCIENCE, THE LIBERAL AND FINE ARTS, AGRICULTURE, MANUFACTURES, AND COMMERCE. BY ALEXANDER TILLOCH, MEMBER OF THE LONDON PHILOSOPHICAL SOCIETY, ETC. ETC. ** Nee aranearum fane textus ideo melior, quia ex fe fila gignunt. Nee node* vilior . - - 289 XLVII. Account of Lord Dundonald's Difcovery of a Procefs for extracting from Lichens a Gum applicable to niofl Purpofes in which Gum Senegal has been hitherto em- ployed - - - - 295 XLVIII. An Effay on Bleaching*, with the Defcription of a new Method of Bleaching by Steam, according to the Pro- cefs ofC Chaptal; and on its Applicatiori to the Arts. By R. O'Reilly, of the Academy of Bologna, Member of the Lyceum of the Arts, &c. Concluded - 299 XLIX. Obfervations on the Oil extracted from the Female Cornel or Dog-berry Tree, the Comus fanguinea of Lin- naus, Clafs 4,-th; Tetrandria Monogynia. By C. Mar- gueron, of the Hofpital for Military injlruclion at Strajburgh - - - 318 L. Researches refpecling the Laws of Affinity. By C. Ber- THOLLETj Member of the French National Infliiute. Con- tinued - - - - 321 ^il. Experiments on the Afhes of fome Kinds oj Wood by C. Pissis, Phyfkian at Brionde, in the Department of ( \a Haute Loire - a % LII, CONTENTS, LI I. Reflexions on the Difference between the Acetous an% Acetic Acids, By C. Dab it, of Nantes - 334 LI II. On a Cheap'Subfitute for Oil Paint - 338 LIV. Extract of a Memoir on the Bronze of the Antients, ami an Antique Sword. Read in the Public Sitting of the In- Jtitute, Julv 4. By C. Mongez - 340 LV. On iheExpanfion of Wood by Heat. By DAVID Rit- tknhouse, LL.D. Prefident of the American Philofo- phical Society - 343 LVI. Obfervations on the Means of detecting the Prefence of head in Wine. By C. O. Reinecke - 343 LVII. Memoirs of the Life of John Robison, LL.D. Profeffbr of Natural Philofophy in the Univerfty of Edin- burgh, &c. - - - 348 LVIII. On Bleaching. By a Correfpondent - 353 LIX. Eafts rrfpecling the Tranjition of a Species of Ely, from the Chryfalid to the Volatile State. By Mr. John Snart, Optician - '- - 354 LX. Brief Account of the Ijlands of Banda. By a Gentle- man who furveyed them Jmce they came into the Poffeffwn of Great Britain - 356^ LX1. Proceedings of Learned and other Societies 366 LXII. Intelligence and Mifcellaneous Articles 367 THE PHILOSOPHICAL MAGAZINE. 'l ' I. Letter from C. Httmboldt to C. Fourcroy, Member of the French National Injiituie. TCurrana, Oftobe'r i6j 1800. HE capture of the ifland of Curacao, by the Englifh and the Americans, having obliged the agent of the republic, C. Breflbt, and general Jeannet to re-embark their troops, in order to return to Guadaloupe, they have put into this port for want of provisions; and though they intend to remain only twenty-four hours, I have endeavoured to collect for you funic objects worthy of your attention, and which I hope will reach you in fafety. You are well enough ac- quainted with the nature of my travels, and the difficulty and expenfe attending conveyance in the centre of a va(i conti- nent, to know that my object is rather to collect ideas than things. A fociety of naturalifls feht out by government, ac- companied with painters, collectors, packers,- &c, might be able to embrace all the detail of the defcriptive part of na- tural hiftory, and, no doubt, would do fo; but a private per- fon, of a very moderate fortune, who undertakes a voyage round the world, ought to confine himfelf to objects more in- tereft'mg. To ftudy the formation of the globe, and the ftrata which compofe it ; to analvfe the atmofphere ; to mea- fure, with the moil accurate iultruments, its elafticity, its temperature, its humidity, its electric and magnetic charge; to obferve the influence if climate on the animal and vege- table ceconomy ; to compare, on a grand fcale, the chemiiiry and phyfiology of organized beings; — fuch is the labour which I have propoied. But, without lofing fight of this principal object of my voyage, vou may readily conceive thatr with much zeal and a little activity, two men, who traverie an un- known continent, may at the fame time collect a great many things, and make a great many obiervations. Vol.X.N 37. A3 During June 1801. 4 Letter from C. llumloUl During the fixteen months we have been traverfing the vail territorv fituated between the coafl, the Orenoquo, Rio- Nigro, and the river of the Amazons, C. Bonpland has dried, with duplicates, more than fix thoufand plants. I have defcribed with him on the fpot twelve hundred fpe- cies, great part of which appeared to us to belong to genera not defcribed by Aublet, Jaequin, Mutis, or Dombey. We have collected infers, (hells, and different kinds of wood proper for dyeing; we have difTecled crocodiles, lamantins, apts, and the gymnotus eleclricus, the fluid of which is ab- folutely galvanic and not electric; and have defcribed a great many ferpents, lizards, and fifli. I have made drawings of a great number of obje&s ; in a word, I flatter myfelf that if I have erred it is rather through ignorance than want of activity. What enjoyment to live in the midfl of thefe riches of nature, fo majeftic and grand ! Behold, then, the deareft and moll ardent of my wifhes gra- tified! Amidfl the thick forefts of the Rio-Nigro'; furrounded by ferocious tygers and crocodiles ; my body tormented with the (lings of the formidable mofkitos and ants ; having had for three months no other aliment than water, bananas, and manioc, among the Otomaqua Indians, who eat earth ; or on the banks or the Cafquiara, under the equator, where, in the courts of a hundred and thirty leagues, no human being is feen ; — in all thefe cmbarraliing fituations I never repented of my undertakings : my fufterings have been great, but they were onlv momentary. When I lett Spain I intended to proceed directly to Mexico, thence to Peru and the Philippines; but a ma- lignant fever, which broke out in our frigate, induced me to remain on this coafl of South America; and, thinking it pofii- ble to penetrate thence into the interior, I undertook two jour- neys,one to the millions of the Chavma Indians of Paria, and the other to that vaft country fituated to the north of the river of the Amazons, between Popayan and the mountains of the French part of Guyana. We twice pailed the grand cata- racts of the Orenoquo, and thofe of Atures and Maypura, in lat. 50^ 12' and long. 5° 39', W. dep. from Paris 40 43' and 40 41' 40". From The mouth of the Guaviara and the rivers Atabapo, Temi, and Tuamini, I caufed my pirogua to bt earned by land as far as the Rio-Nigro, while we followed on foot through forefts of Hevea, Cinchona, and Canell* VYrintertona. I defeended the Rio-Nigro as far as Saint Carlos* that I might determine its longitude by Berthoud'$ ■■ The error in the latitude (d* Anville's chart) is more than two de- grees, as it had never been determined by aftronomical initrumenrs. time-, to C. Fourcroy, 5 time-keeper, with which I am ftill well fatisfied. I afcended the Cafquiara inhabited by the Ydapaminares, who eat nothing but ants dried in the fmoke. I penetrated to the fources of the Orenoquo, even beyond the volcano of Duida, or as far; as the ferocity of the Guaica and Guaharribo Indians would permit me to venture, and I defcended the whole of the Orenoquo, by the force of its current, as far as the capital of Guyana ; performing a journey of 5D0 leagues in twenty-fix days, without counting thofe on which we flopped. My health has withftood all the fatigues of a journey of more than 1300 leagues ; but my poor companion, C. Bon- pland, had nearly fallen a vi&im to his zeal and devotion for the fciences. After our return, he was attacked by a violent fever, accompanied with a dangerous vomiting; which, however, was fpeedily cured. The river of the Amazons has been inhabited for 200 vears by Europeans ; but on the Orenoquo and the Rio- Nigro, it was only about thirty years ago that the Europeans ventured to form a few fettlements beyond the catara&s. Thofe which exift do not comprehend above 1800 Indians, from the eighth degree to the equator ; and there are no other whites than lix or feven miflionary monks, who did every thing they could to facilitate our journey. From St. Thomas, the capital of Guyana, lat 8° 8 ' 24", long. 40 25' 2", we crofTcd once more the great defert called Elanos, inhabited by wild cattle and horfes. I am now em- ployed in conftrucling a map of the country through which I have travelled. I have been fo fortunate as to make aftro- nomical obfervations in fifty- four places. I obferved at Ca- raccas, Cumana, and Tuy, twelve eclipfes of the fatellites of Jupiter; an eclipfe of the fun on the 28th of October 1799. By thefe means, and the chronometer, I flatter myfelf I fhall be able to give a very exact map. We (hall embark here at length for the Havannah, from which we fhall proceed to Mexico. — Such is the fummarv of my travels. I know that you, Chaptal, Vauquelin, Guyton, are all interefted in my fate ; and for that reafon I am not afraid of tiring you. We have fcarcely any communication here with Europe. I have often attempted to write to you, as well as to our friends Vauquelin and Chaptal. I have fent you fome ex* periments on air, and the caufe of miafmata. I have fent to Delambre and Lalande, extracts from my fmall astrono- mical obfervations. Have any of thefe reached the place of their deftination ? By the conful of the republic at Saint Thomas I tranfmitted to you the milk of a tree which the Indians call the cow, becaufe they drink this milky juice, A3 which 6 Letter from C. UumloLli which is not at all prejudicial, but exceedingly nourifhing. By the help of the nitric acid I have made caoutchouc, and 1 mixed Ibda with that deftined for you, according to the principles which you yourfelf fixed. In the month of January latt we fent, by the corvette Phi- lippina, a collection of feeds for the J.rdins des Plantcs at Paris, We know thev have arrived, and muft have been delivered to citizen? .When and Thouin by the ambafTaclor of the republic at Madrid. By the flag of truce, which we ex- pect here fr.om Guadaloupe, the mufamm will receive other articles; for at prefent we muft be fatisfied with prefenting you a few objects for your chemical analyiis. I have procured for you the curare, or celebrated poifon of the Indians on the Rio-Nigro. I undertook a journey to Enneralda on pifrpofe to fee the liane, which produces this juice, but .unfortunately we found it without flowers; and to fee the method praciifed by the Catarapeni and Maquiri- tares Indians for making this poifon. I lhall give you, feme other time, a more ample defcription of it. I (hall only add, that I fend you the curare in a box of tin plate*, and the branches of the plant maracuryr which produces the poifon. This liane grows, but not in great abundance, among the granitic mountains of Guandia and Yumariquin, under the fliade of the theobromacacao and the earyocar. The Indians take off the epidermis and make an infufion of it cold, having firit expreikd the juice; they then leave the water over the epidermis half expreiYed, and afterwards filter the infufion. The filtered liquor ii> vellowilh : it is then baked, and concentrated by evaporation and infpilYation to the confidence of molafles. This matter contains already the poifon, but not being fuffi- eicntly thick to daub over the points of their arrows, they mix it with the glutinous juice of another tree, which they call kiracaguero. This mixture is again baked till the whole is reduced to a brownifh mafs. You know that the curare is taken internally as a ftomachic : it is not noxious but when it comes into contact with the blood, which it deoxydates- It is only a few davs ago that I began to make experiments upon it, and I have found that it decompofes atmofphcric air. I beg you will try to de-oxydate with it the metallic oxyds, and that you will examine whether the experiments of Fon'.aiu. were properly made. lad not till after remaining a long time in the bottles that * ?8o quarts. it and the Method of maling Whies. 31 it becomes clear, lofes its ilifagreeablc thicknefs, and only exhibits good qualities. The greater part of the white Spanifh wines are in this (ituation. This quality of wine has how- ever its partifans, and there are fome countries where the imrft is concentrated for that purpofe, in others the grapes are dried in the fun or in ftoves till they are reduced almoft to the confidence of an extract. It would be eafy in all cafes to excite fermentation, either by diluting the muft, when too thick, with water, or by agi- tating the vintage in proportion as it ferments : but all this muft be fubordinate to the end propofed to be obtained, and the intelligent agriculturift will vary his procefies according to the effect which he intends to produce. It muft never be forgotten, that the fermentation ought to be managed according to the nature of the grapes and agreeably to the quality of the wine that may be required. Burgundy grapes cannot be treated like thofe of Languedoc. The merit of the one confifts in a peculiar flavour, which would be difii- patcd by a ftrong and lengthened fermentation : that of the other in the great quantity of alcohol which may be developed in them ; and here the fermentation in the vat muft be long and complete. In Champagne, the grapes deftined for the white brifk wines are collected in the morning before the iun has caufed all the moifture to evaporate ; and in the fame country the grapes deftined for making red wine are not cut until they have been well dried by the rays of the fun. In one place artificial heat is neceflary to excite fermentation, in another the nature of the muft is fuch that the fermenta- tion would require to be moderated. Weak wines muft be fermented in calks, ftrong wines ought to be fullered to work in the vat. Every country has proceffes prefcribed to it by the nature of its grapes, and it is highly ridiculous to attempt fubmitting every thing to a general rule. It is of importance to be well acquainted with the nature of the grapes employed and with the principles of fermentation : by the help of this knowledge a fyftem of conduct may be formed which cannot fail of being highly advantageous, becaufe it is founded not on hypothefis but on the nature of things. In' cold countries, where the grapes are very aqueous and little faccharine, they ferment with difficulty: fermentation in that cafe may be excited by two or three principal means: 1 ft, By the help of a funnel of tin plate with a very wide tube, which defcends to within four inches of the bottom of the vat, and through which boiling muft is introduced into it. Two pailfuls may be ufed for 300 bottles of muft. This procefs, propofed by Maupin, has produced good effects. y 4 sd, By 14- On the Cultivation tfthe Vine, 2d, By making the vintage from time to time : this motiort is attended with this advantage, that it renews the fermenta- tion when it has ceaied or become weak, and caufes it to be' uniform throughout the mafs. 3d, By laying a covering not only over the vintage, but' found about the vat. 4th, By heating the armofphere of the place in which the vat itands. It often happens that the Working of the viritage' flackens, or that the heat is unequal through the mafs : it is to obviate" thefe inconveniences, efpecially in cold countries, where they are more frequent, that the vintage is from time to time trod upon. Gentii made two vatfuls, of eighteen butts each, and with grapes from the fame vines, and collected at the fame time : the grapes were freed from the fkins, ftalks, -&c. and bruifed ; the juice of both was perfectly equal in quality, and the vintage was put into vats or equal fize : the weather, but particularly in the morning and at night, was exceed- ingly cold. 'A.t the end of fome days the fermentation began : it wa$ obferved that the centre of the vats was exceedingly warm , he edges very cold; the vats were fo clofe as to touch e*ch other, ; and both experienced the fame temperature. Thev were prefTed down with a long pole. The cold vintage was pumed from the edges towards the centre where the heat ftrongeft : it was preflcd down feveral times, and by thefe means an equal heat was maintained throughout the whole mafs. The fermentation in the vat where this procefs had been followed was iiniihed twelve or fifteen hoifrs fooner than in the other. The wine was far better, it was more ate*, had a fupcrior tafle, and was more highly coloured a...i more generous. No one would have faid that it was produced from the lame grapes. The antients mixed aromatic fubftances wi:h the vintage in a tlate of fermentation, in order to give their wines pecu- liar qualities. We arc told by Pliny that it was ufual in Italy to fprinkle pitch and rcfin over the vintage ut odor i'/no contingcret el faporis acumen. In all the works of that period we find numerous recipes for perfuming wines; but thefe different procefles are no longer ufed. I am, however, in- clined to think that they were of great benefit. This very important part of oinology deferves the particular attention of the agriculturift. When we confider the cuftom followed in fome countries of perfuming the wines with rafpberries, fhe dried flowers of the vine, &c. we may even prefage the happieft effects from it. Darcet and the Method of making JVirtes. 75. Darcet has communicated to me the following facts, which- I take the earlieil opportunity of publifhing here, as they may give rife to experiments proper for improving the art of vinification. " I took," fays he, " a calk called half a muid, which I filled with the juice of untrod grapes, and fuch as had run of itfelf from the grapes as carried from the vineyard to the prefs : it therefore had very little colour. " This calk contained about 150 quarts. I took about thirty quarts, which I evaporated and concentrated to nearly about one-eighth of the volume. of the liquor; four pounds of common fugar were added, and a pound of grapes de careme, after care had been taken to bruiie them : the whole, fomewhat warm, was then put into the eafk, which was filled up with the fame muft that had been kept apart. A bunch, of about half an ounce, of abfinthium, dried and well pre- ferved, was then put into the cafk, and the cafk was (lightly covered, with its lid inverted : fermentation foon took place, and proceeded in a brifk and free manner. ff Belides this piece of muft, I caufed to ferment alfo a jar of the fame containing about twenty- five or thirtv quarts, with half an ounce of fugar per quart: this wine fermented very well in this jar, and it ferved me for filling up during the fermentation and after the firft drawing oiF, which was performed at the ufual time, and repeated a year after : it was afterwards put into bottles at the expiration of a year, or in the following winter. " This wine was made in September 1788, during fine weather, and in a very good year. " It kept very well even in the bottle, it neither became four nor turbid at the end of feveral days \ I have (till two or three bottles of it : it begins to fade." IV. Ethiology of Fermentation. The phenomena and refults of fermentation arc fo highly interefting in the eyes of the chemill and the agrieulturift, that, after having conlidered them merely under a practical point of view, we mull now consider them under the relation of fcieuce. The two phenomena which feem mod worthy of attention from the chemili, are the disappearance of the faccharine principle and the formation of alcohol. As in fermentation there is no abforption of air, nor addi-. tion of any foreign matter, it is evident that all changes 8 which l6 On the Cultivation of the Vine, which take place in the operation can be referred only to the departure of thofe fubftances which are volatilifed or precipi- tated. Thus, by (ludying the nature of thefc fubftances, and af- certaining their conltitucnt principles, it will be eafy for us to judge of the changes which rriufft have been produced in the nature of the frrit materials of fermentation. The materials of fermentation are the fweet and faccharine principle diluted in water. This principle is formed of fugar and extractive matter. The fubftanec volatilifed is the carbonic acid gas, and that precipitated is a matter analogous to the ligneous fibre mixed with potam. The principal product, of fermentation is alcohol. It is evident that the tranfition of the faccharine principle to alcohol cannot be conceived but by calculating the differ- ence which mn(l be produced in the faccharine principle by the departure of the principles that form carbonic acid gas which is volatilifed, and the depofit which is precipitated. Thefe principles are, in particular, the carbon and the oxygen : here, then, we find carbon and oxygen taken from the faccharine principle by the progrefs of fermentation ; but in proportion as the faccharine principle lofes its oxygen and its carbon, the hydrogen, which forms the third con- ltituent principle, remaining the fame, the characlers of the latter element mutt predominate, and the fermenting mafs mud attain to that point at which it will only preterit aft inflammable fluid. In proportion as the alcohol is developed, the liquid changes its nature ; it no longer has the fame affinities, nor, conte- quently, the fame dfilblving power. The fmall quantity of extractive principle which remains after having efcaped de- compofition is precipitated with the carbonat of potafh ; the liquor becomes clear, and the wine is made. Vinous fermentation, then, is nothing, but the continued departure of carbon and oxygen, which produces on one hand the carbonic acid3 and on the other alcohol. The ce- lebrated Lavoifier fu ejected to calculation all the phaenomena and refults of vinous fermentation, comparing the products of the decompofition with its elements. He aflumed as the hatis of his calculations the data furnifhed to him by analyfis both in regard to the nature and the proportions of the con- ftitucnt principles before and after the operation. We mall here tranferibe the refults obtained by this great man. $lflteriak and the Method of making Wines. t*t Materials of Fermentation for a Quintal of Sugar. lib. oz. dr.gr. Water - a 400 000 Sugar - - - -J 00 000 Yeaft of beer in pafte 1 Water - - 7 3 6 44 compofed of J Dry yeaft - 2 12 1 28 Total 510 000 Detail of the conjlituent Principles of the Materials of - Fermentation^ lib. oz. dr. gr. 407 3 6 44 Of water compofed of lib. oz. dr. gt. Hydrogen - Oxygen - * loo o o o Sugar compofed of Hydrogen - - Oxygen Carbon '- 0,1% I 38 Dry yeaft compofed of Carbon Azot Hydrogen Oxygen Total 510 o o o Recapitulation of the conjlituent Principles of the Materials of Fermentation. lib. oz. dr. gr. Of the water 340 00 o ^ Of the water of I V1 » Of the dry yeaft 1 to 2 2876 J Of the water 60 o o Of the water of Hydr.^ the yeaft 1 1 2, 71*40^ 9 6" O 870 Of the fugar 800 o Of the yeaft 045 930 n 1 \ Of the fug-ar - 28 00 o 1 0 Carb- loftheyeSft - o „ 4 SS'io} ** li 4 59"00 Azot of the yeaft - - - 005 3*94 Tstal 510 00 o Vol. X. B Tall* 61 1 3 71-40 346 % 3 lib. oz. dr. jot. lib. oz. Jr.gr. 438 6 6 4i Brought over 438 6 6 41 rOf the water 61 5 4 27 Of the water of the alcohol 5 8 5 3 71 8 6 66 Combined with the carbon Hydrogen < in the alcohol 4 0 5 0 Of the acetous acid 0 2 4 0 Of the faccharine refiduum 0 5 1 67 -Of the yeaft 0 2 2 41 0 0 2 37 Of Azot 0 5'° 0 0 2 37 510 000 0 0 By reflecting on the remits exhibited by thefe tables, we may clearly fee what takes place in the vinous fermentation : it is fir ft obferved that, of the 100 pounds of fugar employed, 4 lib. 1 oz. 4 dr. 3 gr. remained in the flate of undecompofed iugar; fo that the quantity of fugar really fubjected to opera- tion was onlv 95 lib. 14 oz. 3 dr. 69 gr. ; that is to fay, 61 lib. 6oz. 45 gr. of oxygen, 7 lib. 10 oz. 6 dr. 6gr. of hydrogen, and 26 lib. 13 oz. 5 dr. 19 gr. of carbon. But by comparing the quantities it will be found that they are fufficient to form all the fpirit of wine, all the carbonic acid, and all the acet- ous acid, produced by the fermentation. The effects of vinous fermentation are reduced, then, to the feparating into two portions the fugar, which is an oxyd; oxygenating the one at the expeufe of the other to form car- bonic acid; deoxygenating the other in favour of the former to produce a combuftible fubftance, which is alcohol; fo that, if it were poffible to combine thefe two fubllances, the alcohol and carbonic acid, fugar would be re-formed. It is to be obferved alfo, that the hydrogen and carbon are not in the Mate of oil in the alcohol ; they are combined with a portion of oxygen, which renders them mifcible with water : the three principles, oxygen, hydrogen, and carbon, are here, then, ftill in a kind of itate of equilibrium ; and, indeed, by making them pafs through an ignited glafs or porcelain tube, they may be re-combined two and two, and water and hy« drogen, carbonic acid and carbon, are again found. [To be continued.] Ba III. Lu- [ 20 ] III. Luminous Appearance, of Ocean-Water caufed by Anl* mals: in a Letter from Prof e //or M itch ill, of New - \ irk, to Profe/Jbr Bart on, of Philadelphia*. OO obvious an appearance as the phofphorefcence of ocean- water was afcribed to animals as long ago as the time of Pliny. Some of thefe adhering to the rigging of veifels in windy and flormy w\ her, and finning in the dark, feem to have caufed the appeal ances known formerly by the names of Caftor and Pollux. Much has been offered on this fubjeft, both phy- fically and hiftoricallv, you know, by Charles Frederic Adler, in his DifJ'ertatio de Nocliluca JMarina, which is well worthy of perufal. He has given a magnified figure of a microfcopic worm, which, in the fea of China, makes the fait water lu- minous. It is called by fome French writers fcolopendre marine luifante, and bv Linne nereis noftiluca. Some of the lea-jellies and fea-blubbers have alfo been long known to be occafionally luminous. The principal part of thefe are me- dufas, which, at a very early *. day, obtruded themfelves on the attention of naturalifts. But, notwithstanding all this, the philofophical world feems ftill to be a good deal undecided as to the real caufe of the phofphorefcence of the ocean. I have therefore recorded the following facls, which fell under my own eye, hoping they may not be without their ufe in explaining the phenomenon. Pennant, in his Britifh Zoo- logv, vol. iv. exprefles very juft ideas on the fubjeel:. On the evening of Saturday, the 13th of September 1800, about high water, as we were preparing, between feven and eight o'clock ^ to bathe in the bay, my attention was called to a remarkable luminous appearance at the water's edge on the beach. The wind was from the fouthward, and the day had been fo warm, that about two P. M. the quickfilver in a thermometer hanging in a {haded piazza, on the fouth fide of the houfe, had rifen to 89 degrees. At this moment it flood as high as 76. The diftance from the chamber win- dows to high water mark is 210 feet. It feemed as if the beach was covered with coals of fire, and that bright fparkles were conftantly emitted among them; The fmall undula- tion which moved to land looked like a wave of flame rolling along the fhore ; and the water beyond, to the diftance of a few rods, exhibited frequent corrufcations of extraordinary brightnefs. On going down" to the water, I found the fand covered with molfufca animals, the greater part of which were the medufa Jimplex. Thoufands of them had juft been * Communicated to the Editor by the Author. left Animalcular Thofphorefccnce of Ocean JVu tcr. % I left by. the receding tide, and were yet alive. Being incapa- ble of living long out of the water, and unable to furvive until the next flood, they fecmed to be under the influence of their laft vital movements. They lay fo thick underfoot, that at every tread many of them were crufhed to pieces. Befides their fpontaneous power to become luminous, whenever they were moved they emitted light; and this happened indiffer- ently, whether their gelatinous bodies were agitated through the medium of air, water, or the direct contact of the feet or fingers. On walking among them, and thereby exciting their luminous action, the beach refembled melted metal in a red-hot ftate; or the phenomenon might be compared to a radiant glory furrounding the feet, to the diftance of a foot and a half, or more, at every tread. In feveral in (lances, the light emitted by a Angle one, when taken, in its frefli and vivid (late, into my hand, was fufficient to enable me to de- termine the time of night by my watch, the minute and hour hands being plainly to be feen : but this brightnefs was but tranfient. Frequently the creature emitted not a particle of light; and then, on a Hidden, the luminous appearance would be confpicuous, and as quickly difappear. The fuc- ceffion of thefe lucid emanations, from the creatures lying in fuch numbers upon the wet fand, refembled, if fmall things may be compared with great, the uniieady light of the fixed ftars ; and, indeed, the twinkling of thefe phofphorefcent ani- mals below, and of the celeflial bodies above, afforded a fpec- tacle fo lingular and fo fplendid, that I fpent good part of the evening in admiring it. I remarked, alio, that the fand on which thefe animals were left by the tide was luminous; and found, on crufhing them to pieces in my hand, that a faint phofphorefcence was imparted both to the fand and to my ikin : but in neither cafe did it laft long. But what was as lingular as any part of the phenomenon, was the effect produced by them upon our bodies and clothes while we were bathing. Whenever the water near one of them was agitated, a large fire-ball feemed to burft upon the view beneath the water; and whenever this happened in con-? tact with one of the limbs, caufed fomc of us inftantaneoufly almoft to ftart, for fear of being burned, Where any of the flimy matter was left, fomewhat of a luminous appearance was perceptible on our clothes, giving them and our fkins fome times the appearance of phofphoric fpots, and fome times the more extraordinary femblance of being painted over with liquid fire. There were more than one fpecies of animal; for befides thofc which, by their magnitude, were very plain fubjects for examination, there were fome luminous fpots as B 3 fmall 12 Anlmalcular Vhofphorcjcence of Ocean Water. fniall as points, and as minute as the eye could difcern. Thefe adhered to our clothes and (kins, and, when taken up with the water in veflels of glafs, were too {mail or too pel- lucid to he diltinguifhed by the naked eve, though they con- tributed eminently towards the eflecl: or this fubmarine illu- mination. This, I prefume, was the nereis nocliluca, an jnteftinal animal. I fuceeeded in diicovering another fpe- cies, which was a (lender worm of about a quarter of an inch lpn'g, and emitted, at times, a bright light of a greenifh hue. This was probably a larger fpecies of nereis. Not being well acquainted with the nature of thofe mol- lufca-beings, I apprehended feme inconvenience from fuch a mafs of animal matter left on the fhore to putrefy fo near the houie. But my caufe of alarm vanifhed before the next rilmg fun : for, during the rccefs of the tide, they all perifhed ; though, inftead of remaining a her, and attached to a cork which fits into the cylinder. The undermoft plate has an oblong hole cut though it (as has alfo the cork), and from this hole a groove pafies to the outer edge of the plate to admit a thin flip of filver A A, and allow it to Hide back- wards or forwards between the plates, for the purpofe of moving the gold leaves a, attached to the iilver, nearer to or further from the upright pieces B and C. This part of the conitruction is alfo fhown in fig. 2. which reprefents the me- tallic part of the cover inverted, AA being the flip of filver. One end of the filver, viz. that which defcends into the cylin- der (fig. 1 .), is flit, for the purpofe of receiving the gold leaves. BB, CC, are two pieces of zinc, the uprights of which can be made to approach to or recede from each other by means of a Hide in the tranfvp.rfe pieces at the bottom of the jar, and which is rcprefented in fig. 3. The two pieces of zinc are kept at the diftance defired by means of the fcrew D, fig. 1 and 3. The zinc BB, properly fpeak.ing, is of two pieces, attached by a joint at E to facilitate the arrangement when the intiru- ment is intended to be put in action. The bottom- part ?;*, which receives the glafs cylinder, is of box-wood, and is furnifiied with glafs feet, FFF, for the purpofe of occasional inhalation. The inftrument being fitted up to my liking, I tried its effect by introducing the exterior end of the flip of filver be- tween my upper lip and gum, and laying the moveable piece of zinc upon my tongue. The diftance of the two pieces of zinc was i-4th of an inch. I could not perceive the fmalleft effect to take place. I tried it with the zinc pieces 1 -8th of an inch afunder, and alio at the diftance of i-i6th, but ftill C 4 without 40 Defcriftlon of a newly invented Galvanometer, without obferving any divergence of the gold leaves or any peculiar tafte. Wlu-n the gold came into ahfolutc contact with the zinc the tatte was mliantty percept ible, in the lame manner as when an immediate connection is eftabliuV'd between zinc, and iilver, by bringing- them into contact between the teeth alter they have been properly difpofed in the mouth; but [ could never perceive, when they were feniibly afunder, the imallett effect, and therefore, after repeated fruitlefs attempts to increafe the action by enlarging; the iurfaees of the metals in contact with the mouth, laid the inftrument afide, as ufe- lefs, except as a more delicate electrometer. As I attributed niv want of fuccefs not fo much to any error either in the principle- or conltruetion of my inftrument, as to the imallnefs of the galvanic charge, M. Voha had no fooner made his pile known, than it occurred to me, that, as a ftroHger charge miffHt now be obtained, the inltrument I had conttructed' would certainly be affected by it, if the elec- tric and geilvanic fluid p off effed, identity. My friend, Mr. Henry Lawfon, having conftru&ed a pile, confiiting of 80 pieces of zinc, and as many of iilver, we made the experiment together. The filver of the galvano- meter was connected with the upper piece of the pile, which was zinc, While the filver end of the pile was in contact with the zinc of the galvanometer. The Hiding pieces BC were then adjuftcd, and, at t lie diftance of i-^d of an inch from each other, the gold leaves diverged : upon prefenting excited gUfe they opened {till further, proving it to be that Hate called plus, or pofitwe. We then reverfed the connection, making the lower or zinc end oi the galvanometer join the upper or zinc end of the pile, and the Iilver flip join the lower or iilver end of the pile. In this cafe, excited glai's made the leaves to dole, while excited feaiing-wax opened them further. When we made This trial of the galvanometer, the pile was giving (hocks, thai were taken with a lenlation equal to what would have been experienced from a charge of as much coated furface of electricity as would, if difcharged through the gal- vanometer, have torn and destroyed the gold leaves, while by galvanifm they were only diverged equal to about i~4th of an inch: even fealing-wax ilightly excited, prefented to the inltrnment, kept the leaves in coniiant motion. Since that time 1 have performed a number of experiments with Volta's pile ; indeed, I have repeated almoft all the ex- periments with it which have yet been made public, befides making Defer tption of a newly invented Galvanometer. 4 1 making feveral a littlcjdiffcrent from any I have vet heard of, and in all of them I have found the galvanometer fo ufeful an inftrument, that: [ ean reeonimend it with {pine confi- dence-to thofe who are fund of fucti experiments. I (hall not encroach upon the pages of the Philofophioal Magazine by detailing the remits of experiments in which others have anticipated me ; but (hall, as briefly as poffible, ftate a few experiments respecting the action of the galvanic pile on feveral of the gates, which prefent foine new facts on this interellino; fubject. In thefc experiments an exhaufted transfer was fcrevved upon the top of a oraduated glafs cylinder, open at the bot- tom. The cylinder being filled with water and placed over a pneumatic tub, was then charged with gas to any particular diviiiou, and the divifion noted, by which means the quantity allowed to afcend into the transfer, upon opening a cock in> tcrpofed between it and the cylinder, was known; and eon- fequently, whether any or what quantity of the gas under experiment was abforbed by the procefs. L The pile being placed, with a I'm all tube containing di (tilled water, and connecting wires of fine filver, in the exhaufted transfer, the quantity of atmofpheric air admitted from the adjoining graduated cylinder was regitiered. After (landing in this way for 36 hours, out of 200 cubic inches of atmofpheric air, 40 were found to have been abforbed. During the whole time of the abforption, gas was formed in the final! tube of water, and a floculent oxyd was precipitated. II. When oxygen gas, obtained from the oxymuriat of potafli, was ufed, the power of the pile was confulerablv in- creafed ; the one wire gave out gas more rapidly, while a much more copious floculent precipitate was formed by the other. Leaving this experiment during the night, 200 cubic inches of oxygen were found tq have been abforbed by the morning. Water had afcended from the pneumatic tub, and not only filled the graduated cylinder, but rifen fo high into the transfer, that the pile was half immerfed in it. The ex- hauftion, thus produced, maintained a column of water of about 16 inches in, height. III. Azotic gas, procured by the decompofition of atmo- fpheric air by the fulphuret of potafh, totally (topped the action of the pile, neither gas nor precipitate appearing in the fmall tube of water. IV With hydrogen gas the effect was the fame. I could not perceive that the pile had the final left action. It is proper that I mould obferve here, that the cloths in- terpofed between each pair of metals in thele experiments A . were 4~ Modns of increajing the Quantities of Heat were moiftened with a folution of common fait. If the cloths be foaked in acids, the refult, as every one knows, will be very different ; the pile will then act as powerfully even in vacuo as in atmofpheric air. An anonymous correipondent, in the lad number of the Philofophical Magazine, notices the increafed action of the pile by acids; but becaufe he finds that the alkalies, particu- larly pure ammonia, alfo increafe its action molt powerfully, infers, that the fluid excited in the pile does not arife from the action of acids, or from any combination of oxygen with ■the metals. Before making fuch an inference, he ought to have tried his pile in fuch circum (lances as would have pre- cluded the poflibility of oxygen having accefs to it. In vacuo his pile would have fpeedily ceafed to act, even with folutions of alkali interpoied between the pairs of plates. He ought alfo to have examined the fiate of the refidual water in the two glaffes, connected by means of a fyphon, before he pro- ceeded to overturn the Lavoifierian fyftem from the circum- flance of oxygen gas being produced in the une glafs and hydrogen gas in the other. The laft paragraph in his paper is equally inconclufive, where he would infer, becaufe an electrometer gives figns of negative electricity when a drop of water is let fall upon a piece of red-hot iron placed upon it, that therefore poiitive electricity and water form hydrogen air. The pre fence of hydrogen is not necefTary to the electrometer indicating ne- gative electricity ; if the water be converted into vapour, the effect is produced : indeed, the vapour of any kind of liquid produces the negative itate. VII. Obfervathns on the Means of increafing the Quantities of Heat obtained hi the Combuflion of Fuel. By Count Rum ford*. JLT is a fact which has been long known, that clays, and feveral other incombuftiblc fubftances, when mixed with fea-coal, in certain proportions, caufe the coal to give out more heat in its com bullion than it can be made to produce when it is burnt pure or unmixed ; but the caufe of this in- creafe of heat does not appear to have been yet inveftigated with that attention which fo extraordinary and important a circumftance ftems to demand. Daily experience teaches us, that all bodies— thofe which * From the Journals cf the Royal Injiitutlon of Great Britain. are obtained in the Comhuftion of Fuel. ' 4$ are incombustible, as well as thofe which are combuttible, and actually burning, — throw oft, in all directions, heat, or rather calorific (heat-making) rays, which generate heat wherever they are Hopped or abforbcd : but common obfcrv- ation was hardly iufficient to (how any perceptible difference between the quantities of calorific rays thrown off by different bodies, when heated to the fame temperature, or expofed in the fame fire; although the quantities fo thrown off might be, and probably are, very different. It has lately been afcertained, that when the fides and back of an open chimney fire-place, in which coals are burned, are compofcd of fire-bricks, and heated red-hot, they throw off into the room incomparably more heat than all the coals that could pofiibly be put into the grate, even fuppofing them to burn with the greateft pofrible degree of brightnefs. Hence it appears that a red-hot burning coal does not fend off near fo many calorific rays as a piece of red- hot brick or Hone, of the lame form and dimensions ; and this interesting difcovery will enable us to make very import- ant improvements in the construction of our fire-places, and alio in the management of our fires. The fuel, iniiead of being employed to heat the room di- rectly, or by the direcl rays from the fire, mould be fo dif- pofed or placed as to heat the back and fides of the grate ; which mult always be constructed of fire-brick or fire-Stone, and never of iron or of any other metal. Few coals, there- fore, when properly placed, make a much better fire than a larger quantity; and Shallow grates, when they are conftrutted of proper materials, throw more heat into a room, and with a much lefs confumption of fuel, than deep grates ; for a large mafs of coals in the grate arre(ts-the rays which proceed from the back and fides of the grate, and prevents their coming into the room ; or, as fires are generally managed, it prevents the back and Sides of the grate from ever being fufficiently heated to affift much in heating the room, even though they be constructed of good materials, and large quantities of coals be confumed in them. It is pofllble, however, by a Simple contrivance, to make a good and an ceeonomical fire in almoft any grate, though jt would always be advifable to continuSt fire-places on good principles, or to improve them by judicious alterations, rather than to depend on the ufeof additional inventions for corre&T ing their defects. To make a good fire in a bad grate, the bottom of the grate muft be firlt covered with a tingle layer of balls, made of good fire-bricks or artificial fire-lione, well burnt, each ball 44 Means of 'increajing the Quantities of Heat ball being pe rfeol.lv globular, and about. %\ or 4 Improvements of the Tort of London, without encroaching upon the property which is now Con~ neeled with the lliores. The poi tion of this plan which has been more immediately under the confideratio 1 of the committee during the prefent femons of parliament, lias been a defign by Meffrs. Telford and Dpuglafs, in which it is propofed to conflruct the bridge of a fuigle arch compofed wholly of caft iron : the fpan of the arch is 600 feet, bdng the width to which, by Mr. Jef- fop's report, the river ought to be contracted, if it is ex- cavated to have 1$ feet at low water: the height in the clear above high water is 65 feet, being the elevation determined by the resolution of the committee laft feflions. The boldne's and fimplicity of this defign render it an object of attention, not only to the committee, who are en- gaged in confidering the further improvement of the port of London, but to men of fcience and practical engineers, and to all who feel an intereft in ,the improvement and credit of their country. It is now generally admitted that the prefent London bridge ought to be removed, being expenfive and dangerous in itfelf, and forming an obltrudtion in the mod valuable part of the river. If the prefent bridge is to be removed, the new bridge fhould be rebuilt upon that plan which mould leave the river clear of obftacles, and, at the fame time, reflect moft credit on the Britifh artifts. If a fingle arch can be cojiurucled without endangering the folidity and duration of the ftructure, moft undoubtedly there can be only one opinion as to the propriety of adopting it. It would be a great national work^ combining the greateit degree of utility and magnificence, and fuperior in its kind to any thing the world has yet fcen. In a work of this nature it would have been imprudenfto have been guided by the judgment or opinion, of any indi- vidual ; it therefore became neceifary to collect the fentiments of all the perfons moft eminent for fcientific knowledge and practical ikill : this has been done by the committee in the moft effectual and impartial manner that could be devifed, by tranfmjttingr copies of the plans, explanatory drawings, s.nd the queries relating thereto, to perfons who are well qua- lified to iayeftigate the fubject : thole gentlemen have taken it up with an impartiality, candour, and patriotifin, which does them much honour, and have furniflied able and fatif- factorv demon (1 rations and opinions. The refult is, that an arch, of the plan and dimenfions referred to their confider- ation, may be conftructed fo as to be rendered a fubftantiai and durable edifice. . ' The and of the intended Bridge, 6$ The particulars of thefe mafterly difquifitions are contained in tiie Appendix to the fourth Report of the Select Committee for the further improvement of the port of London : they will be the means of throwing much new light on this im- portant fubject, and will, molt probably, change the princi- ples and practice of this fpecies of architecture. It would require many drawings and much detail to convey an adequate idea of the form and conftruction of this magni- ficent arch ; it cannot properly be mown as whole in a draw- ing upon any fcale that would fuit a publication of this na- ture. We underfiand the public curiofity will be fpeedily gratified with a perfpective view, taken from the Surrey fide of the prefent London bridge, on a plate four feet long and two feet wide, and which, befides the new bridge, compre- hends the principal objects in the cities of London and Weft- minfter, from Bow church to Whitehall ; and the propofed wharfs, warehoufes, and terraces, between the bridges. The bridge part is engraved by that eminent artill Mr. Lowry, whole fcientific knowledge is only exceeded by his dexterity as an engraver; and al! the relt by Mr. Malton, whofe views of London have done him honour, and qualify him to give the back ground with a precifion which no other artift could be ex peeled to equal. According to this plan, the bridge is to be compofed wholly of call: iron, which is much lets liable to decay or alteration than hammered iron. The ribs are to be call in pottions of as large a fize as to be conveniently .moulded, and caft correctly, and fuch as can be readily managed in the removing and put- ting up : they are to be connected together by crofs and di- agonal tyes and braces, placed in fuch a manner that any of the pieces of the ribs or tyes, or braces, may be taken out feparately, and be replaced without injury or interruption to the bridge. The ribs will receive the weight and preflure in a direction that the itrefs will operate upon the pieces of iron endways ; therefore, before the bridge can give way, the iron mult be crufhed to pieces. All the frames or ribs are to be connected vertically and horizontally from the foffit of the arch to the roadway, fo that the whole bridge will act as one frame, and by that means lefien the lateral prelfure againlt the abutments, and