abt x! ita art 7] ay yy) No AL ; VA : - % ’ Un. AL Lo” “7 hi ade 5 Ty i Publifhed the Laft Day of every Month, Rt - S* (PRICE TWO SHILLINGS.) THE _ PHILOSOPHICAL MAGAZINE. NUM B-ER- XIV. JULY 1799. st a CARS Psat ti & iLivarmATeD w ate a THE FOLLOWING ssi pias BY MR. LOWRY: 1, A 4to Plate: relative to the sien of the Souk of We Oxyde of Tin. A Plate illuftrating the beft Conitruéion of the Vanes of v : Windmills, fo far as concerns the Angle of Weather. re Be iS LONDON. PRINTED FOR A- TILLOCH? DE And fold by Meffrs. Ricuarpson, CornhiJl; Capace and Davies, ‘Strand; Desrerr, Piccadilly ; Symons, Paternofler-row; ka Munway: a and Hicuier, No. 32, Fleet-ftreet; Berx, No. 148, Oxford-ftreet ; Vexnor and Hoop, Poultry 5 see No. 36, St. James’s-ftreet; WesTtry, 0.71 §9, Strand; J. Remwanz, High-ftreet, re cad ae 'Bloomtbury'; W. Girpert and ArcHar, | | ge : Dublin; and W: ReMNAMT, - ay p aaeeerel , Vol m1. is ‘quien gus ‘uclaniet of the. : totaal b: gee Mr. Keith’s new invented Thermometer, which marks the . and leaft Degree of Heat from one Time of Obfervation to another, and regifters its own ‘Height at every Inftant—M - Keith’s new Barometer, which marks the Rife and Fall. of “Mercury from two. different Times of Obfervation—Mr. Brow ~ improved German Key for extraGting Teeth—M. Van. vi Gazometer and Apparatus. for ‘producing: Water by the uftion of Hydrogen Gas in Oxygen Gas—the Dhhiggetai on rEq Temionus of the Eafietr Dede of Middle Afia—the anis G: Plbemicus, or Trifh 7 rolf Dog— the” jy mae empl oy cd Sh or Philofo of ical Experiments ane Conver fations, for combin- ing E ydrogen. and ¢ en nee : oy yy Mr W. Wood, F.L i tke. Eleétric Fluid— 1e Ap SHY ‘employ ed by ; hardening and‘ tempering Steel—the Planet. ‘Saturn, with ‘es ig and two innermoft beat il as Scns cal * Ws aoa a Lal eer. Rupp’ 8 Appara P _-muriatie Acid, for the Pr naa _ tion of Alkali—Repr efer + bertfon’s Apparatus : 0 aoe App ' 43M TM is “Tlutated ee an detec - Diving Machine, ‘by which a ‘Perfon ~ Depth in Water, and. ‘move, walk, and w Apparatus, employed by Mefirs. ‘Pepy fix Pounds of Mercur Ly Article Goldy or Freezin &c. The Apparates propofed to b added’ Bae ay 7 ce Machine, to render it more. fivel eful—Captain Bolt ibe Machise for drawing Bolts in and ut of Ships—Cit, pee Eudiometer; the improved Machine for Cutting Chaff, i y Mr. Robert | almon,” of foburn, ombud for ba Bounty ‘was voted to him | th § of | Atts, dc. —The ‘Se Ss = ent be 4 bate ein 5 4 re xd a et he ie aon and employe : nee hereon Catti iy Ae ee oi Microfeope; drawn nd-engraved Gn the poffeffion of Dr. Thoraton us Loerie es of forming Figures’ with §: % te Dr. Chladni’s Theory. — ~ Chemifts in | their Examination “mediate Co verfion of Tron - Numbe HI, fs il / Molta’s Theory of Ga bc oa for. He i Publifhed the Laft Day of every Month, ‘(PRICE TWO SHILLINGS.} _ PHILOSOPHICAL MAGAZINE. Se ea bo RB eee NUMBER XV Balls gerne AUGUST i999. | rg re eriR — picamanen wiTk / THE TOLLOWING ENGRAVINGS BY MR. LOWRY. 1 ‘Mr. Muster’s Pyrometer for afcertaining the Heat of am— “Affay-furnace. ‘ Me : _ 2 Vow Haucn’s New Difcharging Electrometer, laid before eRe 1°... Royal Society of Copenhagens And, EPR SS 3. Humpox7’s Portable Barometer for Travellers, &c. L ONDON: URN * pRinrED BY J. DAVIS, CHANCERY LANE; ent ; ; FOR A+ TILLOCGH: ae ie Ss And fold’ by Mefirs. Ricu~rpson, Corphill; Capexy and Dariss, . y, and; Desrerr, Piccadilly ; Symonps, Paternoftei-row;. bal | Murray and Hicurey, No. 32, Fleet-ftreet; Beut, pee! “No. 148; Oxford-ftreet; Vernox and Hoon, Poultry; SES Harovine, No. 36, St. Jamce's-ftreet; Westiry, a y’ No. 4 59, Strand; J. Remnan’, High-Rreet, iS Blopmibury; W. GiieerrandAscazr, - ‘ ht Dublin; and W. Remvawr, 4 : ex. Hamburgh, aE a cal Publication, viz. Mr. “it at Kiel—The Jumping Ivioufe of Canada, coloured after } B33 po _ tion of Alkali—Reprefentation We 7, at Machine, ' to render it more oh xe 4 tay? Vol, 1% 4s ahateesa faith ‘poheaiae rs of ‘the following § Sut ay Mr. Lowry, executed in fuch a° matterly: Manner as, we. a1. - fay with. confidence, has. never been equalled i in’ any. other: periodi. 3 Cattwright’s: ‘Steam Engine—, _ Furna for -corverting Tron into Steel—Mr. Des. -Vignes’s new invented "Apparatus for making Artificial Mineral Waters—The Mechanifm of the Jarge Réflecting ‘Telgicope conttruGied by Profeflor Sch - ——Lavoifier’s Apparatus for producing ‘Water by the Comb ‘of Hydrogen Gas in Oxygen Gas—Cavallo’s “Apparatus for ec 8 ron Gas of ary Kind, and tranfmittin it to Bottles, Blad - &cw—Dr. Hock’s Telegraph, invented above a Century. ago—Fi-. gures on the Action and. Power, of the ‘Wedge—Skeleton of the Orang Ovtang of Borneo-—-Regnier’s Dynamometer, or Inftrument, for. meafuring the Streneth of Men, Animals, ee Maeek Figures refpecting the Sguilibrinm and Stability of River and Canal Boats—and Vive Plates illuftrating the Theory of. Cryftallization.. ; ~ Vol. IL. is illuftrated with -Engravings ' ‘of the. follewing: Subs -s, jets :—Mr. Keith’s new invented Thermometers. ne ae marks te : _greatett and Teaft Degree: of ‘Heat from’ one Tit : to another, and. regifters its own Hi. igl Keith’s new Barometer, which marks: the Rife. { a Merciry from two: different T '¢ of Obfetvatio ion—Mr. | e: improved German Key for extaing ‘Te ft —M, “Van ena —Gazometer and Apparatus for producing “Water by the Com. -buition of Hydrogen Gas in Oxygen Gas-the Dhhiggetii or eee - ‘Homionus of the Faltern Deferts of Middle A fia—the Canis ‘Grait Hibetnicus, or irifh Wolf Deg—the Apparatus ployed ‘byt Pi? ty for Pbilof: phical Bxperimenis and- cee: Bal for comb * re a a SD and r RLS ke to ee? ray em] site da ae urn Bf dh. 5 cad ley Schri ‘Oter at L rRine s pectin Tor fatura “Water with oxyge exigtic: Acid, for'the. Pyrp ig, without Addi re) Pealy Excreleence-Me. Cuthe - bertfon’s Apparatus for combining Hydrogen and Oxygen to fo Woater—the Apparatus ef by, ean 1 Water. " Apparatus « em so ed by Mets ane wea a fix Pounds of oe Artt Cc aid kes: The Apparatus ] opted to Machi ne for drawing vibes! Sit apd: ‘out a ae - Eudiometer';, the. arate M: ehjne fo _Pablified ies Laf ‘Dy of every Montb, oie _ (PRICE TWO SHILLINGS,} at é Be é THE PHILOSOPHICAL MAGAZINE. NUMBER XVI. ‘SEPTEMBER 1799. . ithe Ry t | +) SELUSTRATED WITH A rs THE FOLLOWING ENGRAVINGS BY MR. LowRy. ee a. A Plate to illnftrate the Siete Height bf the Moun- ae - ~ tains. of Venus, the Earth, and the Moon; according to, the “Obfervations of M. ScuroeTEr of Lilienthal. 2. €. Recuise’s New. Powder-proof for afcertaining the com- _ parative Strength of Gunpowder. And a mictofeopic. re~ prefentation: of certain Animalcula found on the Surface of a ots in eee which gave it a Red Appéarance. - . P +s Od ‘ i“ . c i OND ON: 5! rine, ‘PRINTED BY Fs DAVIS, CHANCERY. LANE 5 FOR Ae ex LLOCH:. oo fold by Maeffis. RiGHARDSON, Cornhill; Capt. and tas | Strand ; Denker, Piccadilly ; Simons s; Paternofter-row ; » Muregay a Hicutrey, No. 32; Fleet-ftreet; Bex, ere No. 148, Oxford-ftreet; Vaxnor and Hoop, Poultry; 8 et Bieta No. 36, St. James’ s-fireet; Westuey, Tae No. 159; Strand; J. Remwanr, High-ftrect, me a SS Bloomfbury ; W. GirpertrandArcnher, . Dublin; and W. Remyarr, \ i iatinalets v . fay with confidence, has never been equalled in any other periodi~ _- for converting Iron into Steel—Mr. Des Vignes’s new invented ',. Apparatus for making Artificial Mineral Waters—The Mechanifm vO ys Sanaa wathieg Vol. I. is illuftrated with Engravings of the following SubjeQs, by Mr. Lowry, executed in re a mafterly Manner as, we can) Pah rg cal Publication, viz. Mr. Cartwright's, Steam Engine—A Furnace of the large RefleCting Telefcope confiru@ted by Profeflor Schrader at Kiel—The Jumping Moufe of Canada, coloured after Nature —~ —-Lavoifier's Apparatus for producing Water by the Combuition ies Animals, a7 att . ~ < ee eos Ja, F amp eee | > ry ae 7 Fhe it a. K Aly F NEP treet THE | I[LOSOPHICAL MAGAZINE: THE VARIOUS BRANCHES OF SCIENCE, THE LIBERAL AND FINE ARTS, AGRICULTURE, MANUFACTURES; AND COMMERCE. re SA ETE ET BY ALEXANDER TILLOCH, MEMBER OF THE LONDON PHILOSOPHICAL SOCIETY. ‘ y 94; 95» 96 and 97 6 Method of preparing the Dutch Turnfol Blue - Ey On the apparent Converfion of Silver into Gold. es Pro- Selfor pp ee manny of Erlangen - 18 Fitjiory of Ajfironomy for the Year 1798. Read in the College de France, Nov. 20. By JEROME LALANDE, In/peéior and Dean of the College, and ee merly Direéior of the Ob- JServatory 23 Progrefs of Dr. Mircutty’s Mind in invefligating the Caufe of the Peftilential Diflempers which vifit the Cities of America in Summer and Autumn. Being a Develope- ment of his Theory of Pefiilential Fluids, as publi esa fs the World in 1795, and the fucceeding Years ~ On the Ufe of Calcareous Stones in the DMeeifdezurinib or Crude Iron. By Mr. Davip Musuer of the Clyde Iron Works. Communicated by the Author - 43 Account of Bugs ‘found in hollow Trees, with sole on that Phenomenon. By S. OEDMAN - _ Obfervations on Animal Eleétricity ; being the Cn ey i two Letters from A. VouTA to Profeffor GREN - 59 _ Agenda, or a Colleétion of Obfervations and Refearches, the ; a ults of which may ferve as the Foundation for a Theory the Earth. By M. Dr Saussure - 68 bi vinsiois on the Manufacture of the Acetite of Copper or Verdigrife, Verdet, Sc. ByJ.A.CHArTAL - 41 On the Method of preparing Tallow Candles with Wooden Wicks. By Profeffor Mepvicus of Heidelberg 79 Experiments on the Colouring Matter of Vegetable ‘Tigices with , the Tung/tiz Acid, By Cit. GuyTON - 81 Aa Defcription ————-_ iv CON TENTS, Defcription of an Apparatus in the Teylerian Mufeum for the Combujtian of Phofphorus in Oxygen Gas; with Objerva- tions on the Shining of i i doe in Azot. By D. Van Marvumo of Haarlem Page 83 A fimple Method of determining the Moss iane Power of Telefcopes. By Mr, 8. VARLEY. Communicated by the Author + 87 Sixth Communication from Dr. THORNTON, Phyfici ician to the General Di ypenjary, &$c, relative to Pneumatic Medi- cine 95 Biographical eis. of M. De Saussue, By A. P. DECANDOLLE 96 Letter from Dr. CaRMICHIEL SMYTH to the Editor of the Philofophical Magazine 102 On the Longitudinal Vibrations a Seeceahs and Rode, with Obfervations on the Conveyance of Sound through en Bodies. By Dr. Cunanni of Wittemberg pe eo) Ob/ervations on the true Origin of the Gopenes By J. M. BECHSTEIN - 119 Remarks on Mr, Sun~pRaKe’s Di iffer jade Painting n Oil in the Manner of the Venetians. By Mr. EpwarpD Daves. Communicated. by the Author - 124 Progrefs of Dr. MircuiLy’s Mind in imvefliigating the + Caufe of the Peflilential Diflempers which vifit the Cities . of America in Summer and dutumn. Being a Develope- ment of his Theory of Peftilential Fluids, as publifbed tothe World in 1795, and the fucceeding Vears (concluded.) 139 “Account of a Voyage to Spitfbergen in the Year 1780. By S. Bacstrom, M.D. Communicated by the Author 139 ‘An Attempt to arrange the Cryftals of Oxidated-Tin Ore, ac- cording to their fuippofed Strudiure. By Mr. WitLiamM Day, Leicefler Place. Communicated by the Author 152 ‘Bateviments re[pecting the Effects of Quickfilver on Vegetable Life. By Von DEIMANN, Paats VAN TROSTWYK, . and LAUWERENBURGH - 164 Objervations on Animal Eleéricity 5 patents the Subftonce of: two Letters from A. VOLTA to Profeffor GREN | 163 On the Method of manufacturing Acetat of Copper, Cry/ials of Venus, or ime hae Verdigrife. ' By J. A. CHars eg ee Gs 8 ; An Aitempt to ies mine ray true Form and neceffary pal of Weather that ought to be given to Vanes of a Verticab, iWVindmill us they recede from the Centre, left undetermined 4 Mr. Smeaion. By Ricuarp Hart Gower, in the ea Service of the Honourable Ea/ft India, Company . 174. On the Affying of Iron Ores and sabia by Bufion, me 4 CONTENTS. © Mr. Dayip Musuer of the Clyde Iron Works. Com-~ municated by the Author - - Page 178 ' Agenda, or a Colleétion of Obfervations and Refearches, the Refults of which may ferve as the Foundation for a Theory _ of the Earth. By M. De Saussure (continued.) 188 On the Cure of Perfons bitten by Snakes in India. By Joun Wiinrams, E/y. - ie. Cae 191 On the Metallic Particles contained in the Afbes of Vegeta- bles. By M. De La METHERIE - 196 Obfervations on Native Iron found in Strawberries 198 Seventh Communication from Dr. THORNTON, Phyjfician to the General Difpenfary, €§c. relative to Pneumatje Medi- cHe - = - - AO} § On the Glazing of Earthen Veffels without Lead - 203 Geographical Defcription of the Ifles of France and Bourboa 204 Od/ervations on the Property afcribed to Oil, of calming the Waves of the Sea. By 1. ¥.W. Orro - 225 Communication from Dr. MircuiiL, of New-York, fhew- ing the Utility of conftruéting the Houfes and paving the Streets of Cities svith calcareous in preference to filiceous _ and argillaccous Materials - - 233 An Account of Mr. Brown’s Travels through Egypt and Syria, Fe, - - - - 239 Means propofed for faving the Crews of Veffels fhipwrecked near the Coafi. By an anonymous Author - WA On the different Kinds of Cadmia, and particularly thofe of Zinc and Cobalt. By \.1. BinpHEim of Mofcow 250 Defcription of an Affay furnace, with an Apparatus jor mea-~ furing the Degree of Heat employed. By Mr. Davip Musuet of the Clyde Iron Works. Communicated by the Author ~ - - - 255 Agenda, or a Collection of Obfervations and Refearches, the aigleils of, which may ferve as the Foundation for a Theory of the Barth. By M. De Saussure {contimued.) 259 Ddjervations on the different Inducements to the Eating of _ Human Flefh. By J, DE LOUREIRO - 265 Defcription of an improved Difcharging Electrometer. Read before the Royal Sovicty of Copenbagen. By A.W. Vow Havcn, Marfbal of the Court, Sc. to bis Dant/b Ma. jy = 7 - > 257 Otfervations on the Tones produced by an Organ-pipe in dif+ ferent Kinds of Gas. By C.F.F.CuLADNI - . 275 Lutter from E, PeRpoun of the Academy of Turin, formerly Profeffor of Anatomy and the Praélice of Medicine at Tou- loufe, to). C. pE LA MeTuERIE£, on the Acouflic Ex- periments of Chladni - - : 283 F me vi CONTENTS. On a Submarine Foreft on the Eaft Coaft of England. By JosEPH CORREA DE SERRA, LL.D. F.R.S. and A.S. Page 287° On an Epidemical fetal ane Cats. By J.F. gor MENBACH 207 On the Preparation of Crayons ‘wfed ior Drawing, from the Pafte of Reddle. By C. F. Lomet - 299 | ea of Hultsous s New Portable Barometer 304 Pofifcript to Vout a’s Letters on Animal Eleétricity 306 A Statement of the Progre/s in the Vaccine Inoculation, and Experiments to determine fome important Faéis belonging to the Vaccine Difeafe. By Grorce Pearson, MD. F.R.S. Phyfician to St. Care 5 Here ec. Com- municated by the Author - 312 Query re/petting the natural Piuudatbes bibetiote Europe and Afia 327 On ee gradual idsaires in Temperature and Soil which tie place in different Climates, with an Enquiry into the Caufe of thofe Changes. By the Abb MANN - 337 Obfervations on “the Vibration Nodes of Mufical Strings. By J.G. Vorer of Halle 347 Agenda, or a Colleétion of Obfervations and Refearches, the Rejults of which may ferve as the Foundation for a Theory of the Earth. By M. De Saussure (continued.) | 351 Account of alarge Tree in India. By Col. IRONSIDE 359 Account of a Banian Tree in the Province of Babar. E Colonel TRONSIDE On the different Kinds of Biante wad portioalarly sboje S Zinc and Cobalt. be I. I. BinpHEIM of Mofcow (con- cluded.) -4 262 Singular Cure of a young Woman cffecied by expelling Fon the Stomach, @Sc. the Larve of certain eae By M: ODHELIUS 366 On the Signs exbibited ey sens bead Biches Changes of the Weather, with Remarks on other Prognoflications. By M. ToaLtpo = 367 On the Effects of Oil im Cafes of the Bite of Serpents; re- publifbed from the ahaha ie (South-Carolina) City Gazette - Thoughts on Deafne/s ; cers a new Mode of mule boy People bear. “de itten Lg? December eee o by D. WuyrTe, M. D. 378 On the Affayr me of Obes by Faia: ‘By Mr. Davip Musuer of the tad Iron Works. Communicated by the Author ' 380 On the Comparative Height fi the Mountains of the Earth, the Moon, and Venus ~ 393 7 " Defeription ; CONTENTS. vit Defcription and Uje of anew Portable Inftrument for afcer= taining the eee siti of aie’ ae By C. REGNIER Page 394 Account of a Red Badienne sunt on abe Surface of a Fifh-Pond in Norway. By ProfeforH.STRom — 307 Obfervations on the fingular Sagacity of the Rock or Ice Fox 402 An Account of Mr. Brown’s Travels through Egypt and Syria, Gc. (continued.) - 405 On the Difappearance of Hacatiins in Anica ; in a Letter Jrom Mr, Peter Cote to Dr. Mi rien, dated New- York, September 25, 1798 414 Meteorological Objervations made at Basaa's mm ‘the Month of June 1783, with a Differtation on the extraordinary Fog which prevailed about that Tune. By M.Toatpo 417 Obfervations on Pumice Stone, and the Places where found. By Profefor BECKMANN 423 Eighth Communication Srom Dr. Tuornron, ” Phyfici cian to the General Difpenfary, @c. relative to Pneumatic Medicine New Publications - aoe Intelligence and Mi i/ecellancous Basle: 103, 211, 329, 431 Ab oe 7 ee ANS a* ck e ne Ly nase ce ks San , THE PHILOSOPHICAL MAGAZINE, ¥UNE 1700. I. On the Poffibility of Cafual Mutilations in the Bodies of Animals becoming in the Courfe of Time hereditary Marks of Diftinétion, By Profefor BuumMENBACH *. Tu AT it is poffible for mutilations produced in the bodies of animals, either. by accident or by artificial means, efpeci- ally when repeated through‘a whole feries of generations, to degenerate in the courfe of time into hereditary marks of diftinétion, feems 4 priori to be incontrovertible. At any rate, I fhould be glad to fee the phyfiologift who can affign a reafon why this fhould not be as poffible as the tranfmiffion of hereditary organic difeafes, or hereditary monftrofities +, or * From Magazin fur das Neucfle aus der Phyfik.’ Vols V¥a 4 Of the numerous and partly well known inftances of this kind I fhall guote only a recent one, mentioned by M. Schulz in his Objferwations on a monflrous canary bird, pe 17. ‘A Spanith bitch,” fays he, “ which had been in my poffeffion for feveral years, was not only brought forth without a tail, but at various times produced puppies fome of whom were deftitute of tails alfo. As often as this bitch brought forth more than one Puppy, ene of them perhaps was quite perfeét; the greater part, however, had half tails or tails ttill fhorter, and oné at leaft had no tailat all. The moft fingular thing was, that the young almoft always had a refemblance Vor. 1V, B te v 2 On the Poffibility of Mutilations in Bodies or the moft individual traits in family likeneffes, fuch as 2 thick under lip, &rong eye-brows, and fo on, which certainly did not all defcend from Adam but which. have firft ap- peared at a certain generation, and fince that period have been continued, with more or lefs con{ftaney, by hereditary tranfmiflion, EB. Enftances among Animals. We are told by Sir Kenelm Digby*, that the taif of a cat having been cut off when young, fome of the kittens, which the’ afterwards brought forth, were always without tails. Nath. Highmore ¢, who in explaining the mature of generation differs fo much from Sir Kenelm, fays that he faw a bitch which wanted almoft the whole tail from the rump, and that the half of her young were brought into the world with tails, and the other half without. Buffon { afferts that he faw dogs, the ears and tails of which had been cropped for many generations, and which transferred this mutilation, either totally or im part, to their pofterity. M. R. Mafch, of New Strelitz, gives an account, in the Naturforfcher §;, of a butcher’s dog, the tail ef which, ac~ cordizig to'cuftom, had'been cut off, and which having co- pulated with a fhe-wolf, that had been caught, the latter produced three Baftards. Among thefe was a male, half grey like the father, and born with a cropped tail; fo that the- cafual mutilation of the dog, as the author fays, was tranf- ferred to this baftard. We are told by D. Forfter ||, that it has been remarked ine to tlie father, whether grey-hound, fpaniel, &c. in regard to colour and bodily conformation ; and derived nothing more from their mother, the Spanifh bitch, than the fngularity- of having only the third’ part of a tail, or. no tail at all.” * On the Nature of Bodies, p. 214. + Hiftory of Generation, p. 31. + Hioire Naturelle, vol. xiv. § Part xv, Beytrage zur Volker-und Lander-Kunde, Part r. En gland 3 2 becoming hereditary Marks of Diftinfion. 3 England, that when horfes are continually docked, and both ftallions and mares kept fo for many generations, the foals, at laft, come into the world with fome articulations fewer in the tail. Buffon * has enlarged pretty fully on this fub- ject, and endeavoured to prove, by the help of anatomy, that the callofities on the breaft-bone and knees of the camel are merely the confequence of their fubjection, and the force by Which thefe animals of burden, as is well known, are obliged to kneel down; and as the young camels, when brought forth, have callofities of the like kind, he gives this asa proof of the hereditary tranfmiffion of fuch variations pro- duced by art. If. Infiances among the Human Species. -Cardan+ fpeaks of the well known ancient cuftom of the Peruvians of Puerto Viego, who preffed between boards the heads of their new-born children. This cuftom, how- ever, became afterwards like a fecond nature; fo that, in the courfe of time, children were brought into the world with heads formed in that fingular manner: and Cardan exprefsly fays, that this flatnefs of the head was originally the work of art, and not of nature. Con/lat igitur, to ufe his own ex- preflions, bumanam for'mam multis modis variari, tum arte, tum diuturna fuccejfione. Hippocrates, in his work upon air, water and climate, mentions fomething of the like kind in regard to the Macrocephali, a people on the borders of the Black Sea, who preficd the heads of their new-born children 5 and this practice repeated, through many generations, pro- duced at length an hereditary diftinétion; fo that the chil- dren were born with heads of a particular form. ‘ At firft,’”’ fays he t, ‘‘ the practice of the country feems to have been the caufe of this conformation; but cuftom afterwards bes * Hittoire Naturelle, vol. xi. t Vol. iii. p. 162 of Spon's edition of his works. } This paifage is tranflated from the original in Chartieri’s editions vol, vi. p. 206, Ba came 4 On the Poffibility of Mutilations.in Bodies came-nature, »Thofe who had the largeft heads were con- fidered as the nobleft; and for this reafon the Macrocephali prefled the yet pliable tender heads of their children with their hands, and forced them to extend:in length by bandages: and other means. This artificial procéfs gave occafion to the fubfequent increafe of fize in the head among. thefe people, . fo that artificial means were no longer requifite for that pur- pofe.”? Hippocrates, however, adds in a fhort feGtion: ¢* That. in his time their heads had no longer that fingular form. completely, becaufe they had entirely neglected the above. ? artificial means of formation.’ tradicts his preceding account and opinion is fhewn by the, intermediate paflages, where he endeavours te explain the phenomenon from his well known theory of generation. <‘ The generative matter,” fays he, ‘is collected from.all parts of the body. From found bodies it comes found, and, from difeafed bodies difeafed. Now, as bald heads, blue. eyes, and overgrown bodies are tranfmitted in families, and the like rule takes place in other circumftances of conforma- tion, why fhould not children with great heads be produced 593 by great headed parents? meant only that in the courfe of time Nature fometimes abandons forms fhe has affumed, and returns again to the original. Ariftotle, in his work on the generation of animals, fpeak- ing of the grounds on which the theory of Hippocrates re. {fpecting generation is founded, fays: ‘ It is very probable for this reafon, befides others, that children not only refemble their parents in internal and innate properties, but even in external marks which are merely cafual; for there are in- ftances of moles being tranfmitted from parents to their children, and on the very fame parts of the body. He him- felf quotes a Chaldean, who, haying a mole on his arm, tranf- mitted it to his fon, though in the latter it was not fo appa- rent as in the father. Pliny alfo, where he treats of marks, moles, and the like, bemg fometimes inherited by children, adds, But that this very little con-. [ippoerates, therefore, evidently. Pas ee becoming hereditary Marks of Dijtinétion. 5 adds, by, way of example: Quarto-parti Dacorum originis nota in brachio-redditur, In my opinion, this paflage alludes ‘to the hereditary tranfmiffion of moles among the Dacians, illyrians, &e. who, according to! the:teftimony of many of the Ancients, were diftinguifhed by this fingularity. .THedate M. @fann ance came to me, full of aftonifhment, and told me that he had met with a fimilar inftance in the family of a ftaff-officer, who lived in the neighbourhood. The father in his younger days had received a wound in the little finger of his right hand, which had been rendered erooked during the cure; and his fon and daughter were born each with the little finger of the fame hand crooked. I have fince feen both the father and daughter, and have been convinced, by infpecting their hands, of the truth of tlic above information. A literary man of very great acutenefs, when conyerfing with me on this fubject, ftarted the following objection : *¢ If artificial mutilations ‘can ‘become hereditary, children born of circumcifed parents muft often be born without the forefkin, which does not appear to be the-cafe.” At that time I was acquainted with only one inftance of this kind in Steph. Gerlach’s Journal; but one example did not ap- pear to me to be of any peculiar weight. 1, however, once happened to afk a Jew of this place, a man not deftitute of learning, and well acquainted with the ritual of his nation re{pecting this circumftance, and was told that it frequently happened that the children of the Jews were brought into ‘the world with fo fhort a forefkin that it required an ex- perienced and careful hand to circumcife them. This in- nate deficiency is diftinguifhed by a particular Hebrew ap- pellation, xauld mohl, or born circumcifed. His own father, who had cireumcifed above 700 boys, and who was cele+ brated on account of his expertnefs in this cafe, not at all uncommon, often fpoke of the difficulty of performing the operation under fuch circumftances. In a word, what had appeared to me an argument againft the hereditary tranfmif- B3 fion 6 Travels through Turkey, fion of artificial mutilations, became unexpectedly an im- portant argument in its favour. I will, however, readily acknowledge, that all the cafes above mentioned may not be of equal authenticity, and equally incontrovertible; but even though the leaft improbable fhould be rejeéted, there will fiill remain, to fupport the probability of the thing, as many as could be defired for a propofition which cannot well be proved by direct experiments made for the purpofe. Il. Report on the Travels of C. Ouvtvier and C. Bru- GUIERE, undertaken by order of the French Government, through the Ottoman Empire, Lgypt and Perfia, during the Years 17925 93> 94> 95> g6 and 97*. [Concluded from the lait Volume, P: 347-4 "Tuts journey was extremely interefting; for, befides the great number of objeéts which we collected, and the ob- fervations we had occafion to make, we were furprifed to fee a country exceedingly fertile, yet almoft a defert, and often volcanic, exhibiting, at every fiep, vefliges of ancient cities. We croffed the Euphrates and the Tigris on wretched wooden boats ; and two rivers, which flow from the moun- tains of Curdifian, on boats formed of a number of inflated fkins joined together. I {hall defcribe, with fome minute- nefs, this fimple method of crofling rivers, becaufe it might be employed with advantage in Europe, on account of the facility and trifling expence of tranfporting a great number of fkins ; of mflating them in a moment, and uniting them firmly together by means of the branches of trees; and of conveying, in this manner, over the largeft rivers, a whole army without any danger, When we arrived at Bagdad, the pacha was fo ill that two Perfian: phyficians, who attended him, had given over all * Read in the Sitting of the National Inftitute, February 1th. By C. Olivicr, . hopes ! ‘ & : , “ . 2 : % } no a i ek ON + OE wi ip age | 4 ill Egipt and Perfia. 7 hopes of ‘his seeoyery. His aftrologer had read in the ftars the fatal fentenee; the kiaya pacha-and fome of the grandees were already forming intrigues to fucceed shim, and the janiffaries were takéag up arms to fell their fervices to the ighet bidder. The Arabs of the defert, and of Mefopo- ¢amia, waited only for the moment of his death to plunder the caravans and reb travellers. "This city was threatened avith a general infurrection. Commerce was fufpended; and it was impoffible for us to continue our journey. The pacha begged us to give him our advice, until we fhould have an eppertunity of fetting out for Perfia. We thought ourfelves bound to comply with his requeft, and had the fatisfaction to reftore him to health in the courfe of a few days. From that moment order was every where re-eftas blifhed; and the kiaya alone paid, with his head, for the fteps he had taken ‘to aflume the place of his benefactor. The pacha fhewed us every mark of gratitude, made us 2 prefent of two fine Arabian horfes, and gave us letters of re- commendation to the khan of Kermancha, and the minifters’ of the king of Perfia. We did not delay a moment to provide ourfelves with Perfian drefles, and whatever elfe svas neceflary; and de- parted on the 16th of May 1796, with the regret of leaving Sehind us a box containing feveral very valuable jewels, deftined as pregents to the Perfian court, which the envoy of the republic at Conftantinople was to have fent after us. The ufuai heat at Bagdad, during fome hours of the day, is from r10° to 113° Fahr. On the day of our departure the thermometer was already at 995° Fahr. We had here an opportunity of feeing a phenomenon which explains the origin and caufe of that fingular and tranfitory wind which defiroys men and animals, if proper precautions are not taken to guard againft its effects. On our arrival at Kermancha, the firft city of Perfia, we waited on the khan, made him acquainted with the object of our trayels, and delivered to him the letter from the B4 pacha ¢ a om Ot 5 Travels through Turkey, pacha of Bagdad. The khan afked us many queftions re- f{pecting the different {tates of Europe, with which he feemed to be little acquainted, and refpeéting our manners and cuf- toms. He dwelt moft on the countries.of the Ottoman empire which we had traverfed, and particularly Bagdad, beeaufe in that city the afhes of Ali are preferved. He gave orders to one of his officers to accompany us to court, and procured us the neceffary paflports. On the 1ft of June we arrived at Teheran, where we learned that the king and_his minifters had fet out in the beginning of {pring on an expe- dition, the objeét of which was fuppofed to be the conqueft of all Chorazan. I was highly pleafed with the idea of undertaking this journey, and I confidered it as a fortunate circumftance that the king was at the head of an army in one of the moft in- terefling provinces of Perfia; into which no European traveller had penetrated, and which produces the moft re- markable plants, as well as the greater part of the drugs brought to us from the Eaftern countries; but C. Bruguiere had been il] for a long time, and was threatened with a dyfentery. The dragoman himfelf was indifpofed, and rea- fons were not wanting to difluade me from undertaking the journey. © Tt is not pofitively known,”’ faid fome, “ where the king is; and it is dangerous to approach the army in this country, becaufe people are plundered, and even killed, ‘before they can be known and protected. It will require ‘more than a month to reach Chorazan, and the king mutt return in two.’ Thefe reafons did not counterbalance the ‘advantages which were likely to refult, from this journey, to natural hiftory and geography; but -I reflected that the health of my colleague was becoming daily worfe, and that he was incapable of fupporting the fatigues of travelling fo far, during the hotteft feafon of the year. Ht would have been neceflary to traverfe the Mazandaran, a hot, marthy, and extremely unhealthful diftri€t; and befides this, the dragoman refufed ta accompany us. We then agreed to se wait ¥ ‘egypt and Perfia. 9 wait for the king in the environs of Teheran, in order that we might take advantage of the feafon proper for refearches in regard to natural hiftory; for collecting feeds, and for enabling C. Bruguiere to re-eftablith his health with more facility. We were abies to negotiate, and to make fome pecuniary facrifices, before we could obtain permiffion to quit the town, and refide in a village at the bottom of mount Albours. eheran contained hoftages from all the great cities of the empire, whom Mehemet had caufed to affemble there for his fecurity ; fo that people might enter the city, but could not depart from it without the exprefs leave of the governor $ and the latter did not let flip fo fine an opportunity of forcing us to expend a little money. As we forefaw that the pre- fents left behind might be retarded, and not even reach us, we thought it prudent not to make any mention of them. We had it in our power, indeed, to offer the governor a watch and fome arms; but we fhould thus have entered into an engagement to give other prefents to his principal officers, and, on the king’s arrival, having nothing fufii- ciently beautiful to offer to his. minifters, and our pretents being detained at Bagdad under a pretence that the roads were not fafe, we fhould have been confidered as impoftors, and fhould have loft that confidence which our conduct ought to have infpired. The king, after taking poffeffion of Mefched and all Chora- zan, and after having deftroyed Charok-Shah the la{t de- feendant of Thamas-Kouli-Khan, and carried away his trea- fures, returned to Teheran. He made his entry into that new capital towards the end of September 1796; and, two days after, we had an audience of the prime minifter, with whom we had reafon to be fatisfied. We endeavoured to fecure the friendfhip of the chief. fecretary, an active, judi- cious, enterprifing man, and as well informed as could be expeéted in Perfia. We fpoke to him of the new govern- went eftablifhed in France; and, at the fame time, made him BS) . Travels through Turkes, him acquainted with its refources, population, triumphs an& power. We received from him fome interefting details re- fpeéting the manners, religion and government of the Per- fians, as well as a circumflantial hiftory of the troubles which had defolated that unhappy country fince the de- ahronement of Shah Huffein, and pargaculazly fince the death of Nadir Shak. On the 4th of October we obtained from the minifter an audience to take leave; and, fome days after, his principal Secretary gave us a letter addreffed to the French republic, a eopy of which I immediately difpatched, referving the ors ginal, which I have fince prefented to the directory. We now made hatte to.complete our obfervations and to return to Bagdad, as we already forefaw the ftorm which {lil} involves that country in all the horrors of a civil war, We quitted Teheran on the 15th of October, and purfued the road to I{pahan. We had made an ample collection of objects of natural hiftory, and of medals. We had acquired alfo very correét information retpecting the population, re- yenues and forces of Perfia; the late revolution, and the ftate of its commerce. Our travels, however, would have been incomplete, had we not feen the.ancient capital of the em- pire, and the feat of the fophis. We remained a month ag {pahan, and on the 21ft of December arrived at Bagdad. Some European travellers have traverfed Perfia, and have given us accounts more or lefs correct of that empire. They have made us acquainted. with the jadufiry and commerce of the Perfians ; given us long details refpecting the religion and followers ef Mahomet; and have defcnbed the palace and gardens of Shah Abbag and his-fuccefiors, as well as the public edifices of Ifpahan. But the hiftory of the troubles of Perfia fince the death of Nadir Shah; the changes in manners, agriculture and indufiry, which muft have been effected there by intefiine wars, that continued for more than fixty years; the formation of a new empire, more powerful than Perfia itfelf, which extends from Candahar ta Cafhmijre, Egypt and Perfia. ~ Pe afhmire, from Caboul to the country of the Moguls, comprehending the fertile banks of the Indus, cannot fail of giving new intereft to a new narration. In regard to natural productions, it will be feen, by an account of the different fbjects which I fhall not fail foon to publith, how little they are known, and how curious and important the greater part of them are. Perfia is an elevated country, covered with {now in winter from the Cafpian fea to fpahan ; and in fummer, dry and exceedingly warm. It confifts of mountains remarkably high, and of immenfe plains, for the moft part uncultivated, What mutt aftonith every traveller is, that throughout the whole empire no produétion can be obtained without water- ing: neither corn nor vines grow there but by means of water. No trees or flirubs are ever feen, but fuch as have been planted, reared and watered by the hand of man. Water is every where neceffary ; and yet in this country it is naturally wanting. It was requifite, therefore, that the induftry of the inhabitants fhould fupply this deficiency by fubterranean channels, which convey water from all quarters, and end at a common refervoir, By taking advantage of the declivity of the ground, they then draw off different ftreams, near which they form habitations more or lefs confiderable, according as the water, more or lefs abundant, admits of a greater or lefs degree of cultivation, ; Though wounded, at the diftance of fi x days journey from Bagdad, by a band of Curdes, while affi fting my colleague when about to fall into their hands, I was, however, foon able to continue our journey; but C. Bruguiere, whofe life was almoft daily threatened 1 in Perfia, and whofe health was fill uncertain, could not for a long time be prevailed on to proceed. Nearly fix months elapfed before I was able to perfuade him to fet out in order to return home. Several times, on the approach of the fine feafon, did I threaten to leave him; but I could never refolye to do fo, as my con- fcionce 12 Travels through Turkey, fcience would not have ceaféd to'reproach mé, "had thy: com~’ panion, after my departure, terminated his ‘career at a casera tance from his friend and fellow travellér. During the time T refided at Bagdad waiting for the per- fect 're-eftablifhment of C. Bruguiere’ s health, I employed mytelf in colleGting different materials for a hiftory of our travels. I have feen the ruins of Seleucia, Ctefiphon, the fite formerly occupied by the celebrated Babylon ; the towers ealled thofe of Nimrod, which neither time nor the hand of man has been able entirely to deftroy, and which fill excite the admiration of travellers. I had in Egypt and Syria obferved the Arabs, that nation fo fingular, and refpeéting whom travellers have fpoken fo differently. I had ftudied their manners, their cuftoms, and the form of their government. — It ftill remained for me to live among them, to travel with them, to frequent their tents, and to receive from their hands fimple, frugal, and wholefome food. . As particular circumftances obliged’ me at Bagdad to ex- ercife the functions of a phyfician, IT readily embraced that opportunity of feeing the interior part of the Mahometan habitations, and of becoming acquainted with the {tate of theit harems, and the women fhut up in them. No traveller, perhaps, has been able to colleét, in this refpeét, fo ey fingular anecdotes. We departed from Bagdad on the 1ft of May 1797, in company with a carayan deftined for Aleppo. We remained fixty-five days on the banks of the Euphrates, and in the defert employed our time in preparing plants, collecting in- fects, fkinning birds and quadrupeds, and in making obfer- vations on the Arabs; the climate, foil, and productions of thefe countries. We made only a fhort ftay at Aleppo, where we found a letter from C. Aubert Dubayet, in which, after fome compliments on account of our conduét, he re- fpretied we would return by the fhorteft route to France. — This Egypt and Perfia. 13 - This invitation was perfectly agreeable to our wifhes; but it was indifpenfably neceflary that. we fhould pats through Conftantinople. Could-we leave behind us a fcattered col- jection, the fruit of five years labour and obfervations, eXx- pofed to the dangers of the fea and of dilapidation? Is it not certain that objects of natural hiftory, almoft all of 2 perith- able nature, muft be taken care of during quarantines by hands accuftomed to manage them? How eafily might manufcripts have been carried away? We had left fome boxes under-the care of a merchant at Conftantinople, and others in an apartment of the ambaflador’s palace. There Was a great number at Scio, and fome at Latakia. We confidered it as our duty to unite the whole, and to convey them all to Paris ourfelves, in order that it might be feen, on our arrival, whether we had accomplifhed the views of government, and whether we had not deceived the expecta- tions of the learned. We wrote to the ambaffador to make him acquainted with the motives which induced us to take the way of Conftanti- nople. We wrote, at the fame time, to the confuls of Tripoli and ‘Cyprus, begging them to inform us when the firft fhip failed for the Archipelago; after which we repaired to Latakia, where we found only a wretched Venetian fhip, in which the conful advifed us not to embark, as the Alge- | rines, for fome time paft, had infulted the flag of that ex- piring republic. We then refolved to proceed to Cyprus, and to traverfe that ifland, though in the moft dangerous feafon ; to repair afterwards to the coaft of Caramania, and to proceed thence to Conftantinople, by crofling Afia Minor, This journey was one of the moft interefting we undertook, both in regard to natural hiftory and the in- formation we collected refpecting the manners of the Turks, in a country little known, little frequented, and yet fo worthy of attention. We arrived at Conftantinople in the end of Oétober,. and fhould have departed thence ip the Sericufe, fome time after, had 14 Travels through Turkey, had we received our boxes from Scio, and thofe we left at Cyprus. The ambaffador was employed in procuring us 4 paflage in the Brune to Athens and Corfu, juft at the time of his death. After that event, all our efforts to procure a fafe and direct paffage to France being ufelefs, we thought we fhould be fheltered from all danger, and free from all reproach, if we proceeded to our ifles in the Levant, by croffing the ifthmus of Corinth. It was certainly of much importance for us not’ to full into the hands of the Englith, whofe fhips covered the Mediterranean: It would have given us great pain to fee our enemies profit by our labours, and reap the fruit of all our dangers and fatigues. We wrote to C. Carra Saint Cyr, chargé d'affaires of the republic at the Ottoman Porte, to inform him of our plan, and optain his approbation; and at the fame time to afk fome pecuniary affiftance, and make him adjuft the ftate- ment of the fums advanced to us fince our arrival in the Levant. We received a favourable anfwer, and fuch as was fuited to our circumftances. It may not be fuperfluous here to obferve, that we had for a long time reminded the Porte of the fervices we had ren- dered to it in regard to the pozzolana; a fervice it perhaps thought it had fufficiently rewarded by the flattering letter which the Reis Effendi charged us to deliver to the minifter of foreign affairs, accompanied with a prefent of 2000 piaftres. We fhould certainly have refufed, from any other government, a fum {fo {mall and fo ill proportioned to our labour, expences, and the importance of the difcovery, and, in particular, fo far below the promifes made to us; but a yovernment fo little fufceptible of honeft and generous con- du&, would not have been fenfible of the motive of our - refufal. We left Conftantinople with a favourable wind on the goth of April, in a Turkifh boat we had hired; touched at one of the caftles of the Dardanelles, and different points of 2 i the ee Egypt and Perfia. iS fhe Troade, and, for the fecond time, traverfed that fertile country. We paid a vifit to theancient fite of Troy; faw the fources of the Scamander; went along the fhores of the Simois, and thence proceeded to examine the rus of the Troy of Alexander. We fiopped half a day at Ipfera; went on fhore at Cape Sunium to fee the remains of the temple of Minerva, and arrived at Athens on the 6th of May. We did not remain above twenty days in that city, which ex- hibits fo many beautiful monuments, and calls to remem- brance fo great events. I haye brought with me a plan of the ancient arid modern city, by Fauvel; and one of Mara- thon, whiclr I traced out on the fpot. I collected information refpecting the prefent {tate of Athens and the neighbouring country, to compare it with what it was formerly. I have feen Mount Hymettus, the marble quarries of Pentelica, the eities of Eleufis and Megara. We pafled through the Straits of Salamis, where the Perfian fleets were deftroyed; and traverfed the Iithmus to embark agam on the Gulph of Lepanto, from which we repaired to Patras. It was time to terminate our obfervations on the Ottoman empire, and to quit thefe countries, now barbarous, though formerly the feat of the arts, feiences and philofophy. It was time to place ourfelves under the egis of the republic. We arrived at Corfu on the 14th of July, after having fouched at Cephalonia, Ithaca, and Parga. We performed quarantine for 21 days. It was not yet finifhed, and we began to think of continuing our journey through Italy, though embarrafled with a confiderable collection, w nee ee Comeyras, commiflary gencral of the directory, arriv ed.’ We immediately applied to him in order to procure a paflage te Ancona. Ife gave us reafon to hope that he would foon affign to us for that purpofe a fimall veflél belonging to the republic; and, in the mean time, I traverfed the ifland and environs, fometinits alone, and fometimes with my colleague, to procure information refpecting the natural produétions of the 16. Travels through Turkey, @c. the country; the ftate of agriculture, and the improvements that might be made in it; its ports and harbours; the timber of Epirus fit for fhip-building ; the commerce of thefe diftriéts, and the manners and opinions of our new French fubjects. On the 23d of Auguft, and 6th of September, I delivered to C. Comeyras two memoirs, the one being a con- tinuance of the other, in order that he might tranf{mit them to government. On the gth of September we failed in the Brune frigate for Butrento, where we {pent the day, and arrived at Ancona in the courfe of a few days. My colleague, who had been almoft always indifpofed and in a ftate of fuffering fince our tour through Perfia, here terminated his career, on the 3d of Odtober 1798, in confequence of a malignant fever brought on by fatigue. He has left a family in want, whom I doubtlefs have no need of recommending to the benevo- lence and juitice of the government. ‘. [have brought with me, from the countries I have travel- led through, a pretty large colle€tion of plants, feeds, qua- drupeds, birds, reptiles, river fifh, infects, {hells and minerals, as well as of medals, engraved ftones, and other objects of antiquity. I have Egyptian idols and mummies; a felection of drugs, moft of them unknown in Europe; a feries of the medicines employed in Perfia; and, in the laft place, fome rare and valuable manufcripts. . I have juft fent to the na- tional garden of plants, feeds from Perfia, Mefopotamia, the - defert of Arabia, Syria, Cyprus, Afia Minor and Greece, in order to be there fown and cultivated. A great number of thofe‘which we fent home before, have been already reared, and are in a thriving condition. III. Method ae ike di III. Method of preparing the Dutch Turnfol Blue*. I; is well known that the Dutch kept their procefs for pre- paring turnfol blue a very great fecret; and, in order to miflead the public, pretended that it was made from rags dyed with the juice of the fun-flower. (Helianthus), from which it obtained its name. Since the late revolution, how- ever, in Holland, the true method employed by the Dutch for preparing this colour has been difcovered, and the procefs is as follows :—That kind of lichen called orchil (Lichen ro- cella), or when that cannot be procured, the large oak mofs, after being dried and cleaned, is reduced to powder, and by means of a kind of oil-prefs the powder is forced through a brafs fieve, the holes of which are fmall. The fifted powder is then thrown into a trough and mixed with an alkali called vetas, which is nothing elfe than the afhes of wine lees, in the proportion of half a pound of afhes to one pound of powder. This mixture is moiftened with a little human urine, for that of other animals contains lefs ammonia, by which a fermentation is produced; and the moiftnefs is ftill kept up by the addition of more urine. As foon as the mixture affumes a red colour, it is poured into another trough; is again moiftened with urine, and then ftirred round in order that the fermentation may be renewed. In the courfe of a few days it acquires a blucith colour, and is then carefully mixed with a third part of very pure pulve- rifed potath ; after whichthe mixture is put into wooden pails, three feet in height, and about half a foot broad. When the third fermentation takes place, and the pafte has acquired a confiderably dark blue colour, it ig mixed with chalk or pulverifed marble, and ftirred well round that the whole may be completely united. This laft fubftance gives the colour no higher quality, and is intended merely to add " Prom the Handling /xcitung, by J. A. Wildt, for Decessber 1798. Mor, IV. e to 18 On the apparent Converfion to the weight. The blue, prepared in this manner, is poured. into oblong fquare iron moulds; and the cakes, when formed, are placed upon fir boards on an airy floor in order to dry, after which they are packed up for fale. . IV. On the apparent Converfion of Silver into Gold. By Profefor HiLpDEBRANT, of Erlangen*. Tuoucn gold and filver have this common property, that they fhew little affinity for oxygen, and their calces can therefore be revived merely by ignition; their difference in other refpects is fo great, that fcarcely any two metals can be more unlike. Not only is their colour totally different, and the fpecific gravity of gold far greater than that of filver, but filver, in the dry way, forms a perfect union with ful- phur; and in the wet way, with the fulphuric and nitrous acids; whereas gold has no affinity for thefe fubftances. If the tranfmutation of metals were therefore poffible, the converfion of filver into gold would be very improbable. We mutt, however, confider nothing impoffible in nature, ‘the impoffibility of which cannot be demonftrated 2 priori. Each century, and, in the prefent active age, every fhort period of a century, difcovers new phenomena, fome of which are of fuch a nature that they would be confidered as im- poffible, were not their reality fully confirmed by experience. I entertain no dread then of being ridiculed by the un- prejudiced philofopher, if I call the attention of chemifts to a phenomenon in which filver appears to be converted into gold. It is a well known procefs, which I repeat in every courfe of my Leétures, to diffolve filver that contains copper in pure nitrous acid, to precipitate the pure filver by commorr falt (muriat of foda), in the form of horn filver (muriat of filver), and thea to feparate the filver from the latter by fufion with mineral alkali. An experienced chemift af- * From Algemeine’s Journal der Chymie, by A. N. Scherer, 1799. fured of Silver into Gold. 19 fured me, that when filver is revived in this manner, it is in part converted into gold. Since that time I have frequently te-diffolved in pure nitrous acid the filver which I obtained from horn filyer, and always found a fmall quantity of black powder remaining at the bottom, which feemed to have all the properties of gold. My procefs for reviving the horn filver is perfeétly fimple: I pour into a deep crucible a bottom of alkali an inch high, and form in it a hemifpherical cavity with the round end of acupel rammer. I then put the horn filver, well pounded, and mixed with as much alkali (neither of them moiftened), into this cavity, cover the whole with a thin ftratum of alkali, and apply a flow heat, till the whole mafs comes to red fufion; by which means the revived filver is enabled to fink down and colleé& itfelf at the bottom. As vegetable alkali (potafh) produces the fame effeét as the mineral (foda), I employ the former becaufe it is cheaper. I find by ex- perience, that, to form a moift ball of the horn filver and alkali, is not only unneceflary, but even prejudicial; for the moift mixture is tenacious, and unavoidably adheres to the fingers and the veflels, thereby caufing wafte. As the horn filver is fo extremely fufible, and at the fame time a flux for earths, and as it eafily penetrates the crucible, the principal obje& in reviving, according to the above method, is to in- creafe the heat by very flow degrees, fuffering the charcoal to burn only gently for two hours around the bottom of the crucible, that the horn filver may be in a ftate of fufion before the crucible has been long ignited. By thefe means the alkali is enabled to join itfelf gradually to the muriatic acid, and at the fame time fo completely that, when the heat is increafed till the alkali is in a red fufion, there is no longer horn filver but metallic filver prefent, which there- fore may come in contact with the crucible without any danger. For diffolving the revived filver I employ nitrous acid, which I firft purify 2 oarytes from the fulphuric acid, and C2 afterwards 20 On the apparent Converfion afterwards by filver'from the muriatic acid. It cannot here be difcovered, how gold could be conveyed to the filver by the folvent and precipitant employed; and therefore, to ap- pearance, a part of the filver is actually converted into gold. Enlightened chemifts, however, will fcarcely believe in this tranfmutation, and will rather fufpect fome deception. I confefs that I do not myfelf believe in it, and I explain the appearance of gold from the revived horn filver in the fol- lowing manner :—Notwithftanding the great difference be- tween gold and filver, fome filver is almoft always prefent in pure gold; and a little gold is in like manner almoft always prefent in pure filver (in thofe commonly called pure). The cafe is the fame in thefe metals when worked, particularly in coins, even where they are not alloyed one with the other. In all the ducats I have hitherto tried, even in thofe of Holland, I found, on diffolving them in aqua regia, a little filver depofited in the form of horn filver. In all French crowns, even in the fine Harz florins which are perfeétly free from copper, I found a little gold, which, when they were diffelved in the nitrous acid, was thrown down in a dark coloured precipitate, which could not proceed from the al- loying. Dutch ducats, for example, are not, as far as I know, alloyed with filyer; and no one certainly will believe that the gold found in the Harz florins and French crowns was purpofely added to them. ‘The metal of thefe coins has from nature a {mall portion of foreign metals; the gold a little filver, and the filver a little gold, as long as it is not purified by quartation—or the gold by antimony. Ifa folu- tion therefore be formed of fuch filver, the gold remains un- diffolved, and gradually depofits itfelf at the bottom as a fine black powder. It may be readily comprehended, that every chemift, unlefs he has very little experience in fuch procefles, when he withes to precipitate filver as horn filver, will firft pour off and filter the clear folution of, filver and copper from the black gold powder, before he adds the muriat of foda, On a hafty of Silver into Gold. aE a hafty view, one might conclude, that the gold which is af- terwards found in the fame filyer, when revived from horn- filver, could not be a portion ofthe fame gold of which’a part had been depofited on the firft folution of the impure filver. But is it not poflible that even when the folution has fivod a confiderable time, and the greater part of the gold powder has depofited itfelf, a portion may ftill remain fufpended, and its particles be fo minute as to pafs through the filtre ? A ‘well diluted fomewhat ferruginous acid, afier diluted praffiat of potafh (phlogifticated alkali) has been added to it, looks at firft blue, but perfectly tranfparent ; yet in the courfe of a few days real Pruffian blue depofits itfelf at the bottom as a fine powder, and then the fluid lofes its colour. The particles of the precipitate are at firft too fine, and ap- pear under too {mall angles, to be diftinguifhed by the eye as folid bodies amidft the fluid. The cafe is the fame with filiceous earth, when the liquor of flints is much diluted ; and alfo with gold calx precipitated with the mineral alkali from aqua regia, where the tranfparent colourlefs ley poured off from the firft precipitate, and filtred through eight folds of paper, at the end of feveral days again forms a black depofit. As my time is fully occupied with the proceffes neceflary for my Leétures, I have not leifure at prefent to examine this circumftance by a feries of experiments. But, perhaps, fome other chemift, by repeatedly diffolving filver and pre- cipitating it by muriatic falt, may be enabled to confirm or refute my opinion. Obfervations on the foregoing Paper, by Dr. SCHERER. THE preceding remarks are greatly confirmed by many obfervations already made public. Thus Homberg, in fup- port of his affertion that all gold has been once filver, quotes the following experiments: “ If you fufe a hundred times in fucceffion 8 or 16 ounces of filver, which, by previous quartation, you are convinced contains no gold, keeping it each time at leaft an hour in fufion, and afterwards feparate C3 it 22 On the apparent Converfion of Silver into Gold. it by the quart, you will be able to feparate a confiderable quantity of gold, which was not before in it, becaufe you fe- parated by the firft quartation all the gold it could contain. Farther, diffolve 8 oz. of filver in aquafortis, feparate all the undiffolved part, add to it common falt, and edulcorate the precipitate you have obtained and dry it. Mix with it half its weight of well puriiied regulus of antimony prepared with iron, and diftil the whole in a retort over a flow fire. About 3 oz. or more of the butier (muriat) of antimony will pafs over, and, when the fire has been ftrengthened to the utmoft, the filver will remain with a part of the regulus at the bottom of the retort. Fufe this filver in a crucible until no more vapour arifes, and until all the reoulus is evaporated, Then fufe this filver once or twice more in new crucibles with a little borax and faltpetre, and it will become much more beautiful and finer than cupelled filver. If you then granulate this filver and diffolve it in aquafortis, a great many black feales will remain behind, and, on fufing, you will find them to be gold. If you repeat this operation once more with the fame filver and a like regulus, a few black flakes only will remain; and the third time there will be none *.” Boerhaave fays, in his Elements of Chemiftry, ‘If two parts of the precipitated calx of filver, well mixed by trituration with one part of regulus of antimony, be diftilled in a retort in a fand bath, pure butter of antimony, equal in weight to the regulus added, will pafs over. The filver, with part of the regulus, will remain at the bottom; and, when reduced, always gives real goldt.”’ Kunckel {, in like manner, ob- * See Memoires de P Academie de Paris for the year 1709, p- 1333 and Crell’s Neues Chem. Archiv. vol. i, p. 30. + Si enim calcis pracipitate argenti partes due, cum reguli antimonii parte una, triru bene mifiz diftillant ex retorta, igne arena, prodit purum boutyrum antimonii tanto pondere, quo fuit regulus admiftus. Argentum cum parte reguli manet in fundo, e¢ redudium femper dat verum aurum. Elementa Chemiz. Lipfie, 1732. Tom. ii. P- 413, + See his Chem. tradlgilein. p. 146. tained Hiftory of Aftronomy for 1798. 23° tained gold by treating filver with common falt. M. Cappel, by treating filver with arfenic, obtained from four ounces ten grains of gold*. Guyton confirms this experiment, and obferves that, in this manner, 8 grains of gold are obtained from 1000 grains of filvert. The arfenic, in the laft cafes, was combined with gold. Some very important refults, in regard to this fubje&t, might be obtained by examining the works of the ancient alchemifts, as all their aflertions re- fpecting real tranfmutation might be explained by mere fe- paration, without allowing them fo much as fome have done f. V. Hiftory of Aftronomy for the Year 1798. Read in the College de France, Nov. 20. By JEROME LALANDE, Infpettor and Dean of the College, and formerly Director of the Obfervatory. [Concluded from the laft Volume, page 389. ] I SAW at Strafburgh the firft fheets of a new map of Swifferland conftruéted by M. Weifs, to whom M. Tralles communicated his triangles and bafes. This map is ex- tremely well engraved, and gives us an interefting topogra- phy of Helvetia. I paid a vifit, in my paffage, to the obfervatory of Man- heim, which had afforded me fo much pleafure in 1791; but I found the inftruments packed up in boxes and de- pofited in vaults which the bombs had fcarcely refpected, and waiting there for peace, without which neither fcience nor happinefs can exift. The minifter d’Arberg, whom [ requefted to fecond the zeal of M. Barry, fhewed me every mark of friendfhip. * Crell’s Newefle entdechungen, vol. X. p. 136+ + Crell, ut fupra. $ See Crell’s Neves Chem, Archiv, vol. i. p. 212. C4 On 4 Hiftory of Afironomy for 1798: - On the 15th of December 1797, Tycho Brahe’s birth- day, Dr. J. Ch. Burckhard arrived at my houfe. This able aftronomer, born at ‘Leipfic on the 3oth of April 1773, came to reinforce the aftronomical corps in France; and he is engaged in a German tranflation of Laplace’s Mechanique Celefie, or La Theorie de ? Attradtion, now in the prefs. This important work will give the latt degree of perfeétion to our tables: two hundred pages of it are already printed. On the fame day I requefted General Bonaparte to pro- cure a good inftrument for the obfervatory; and on the 19th of March the government granted me 2000 livres to pur- chafe the feven and a half feet mural quadrant of C. le Monnier. We had long folicited good inftruments for the obfervatory. C. Caffini, when direGtor in 1785, had ob- tained a fund for that purpofe from the minifter Breteuil; but he had not time to make ufe of it. When I was direc- tor in 1795 I renewed my folicitations, and we were at length able to procure, the firft time, for the moft beautiful obfervatory in the univerfe, an inftrament worthy of France*. The Bureau des Longitudes has fent thither an achromatic telefcope; but that is not fufficient. On the 3oth of April I requefted from General Bonaparte 10,000 livres to ereét the mural quadrant and the meridian telefcope of the obfervatory; and to make at Paris obferva- tions to correfpond with thofe made by his aftronofhers. He departed too foon; but Neufchateau, the French minifter, is worthy of remedying that deficiency, and gives us reafon to hope for the affiftance we ftand in need of. C. Lefrangais obferved, with a complete circle, the folftices of this year; and I have feen, with pleafure, that the obliquity of the ecliptic correfponds, within a fecond or two, with the table which I gave in my Aftronomy in 1792, and which is em~ ployed by moft aftronomers. * The expence of building the obfervatory is eftimated at a million of livres (40,000l.), without including the foundations and fubterranean places eighty fect in depth, On Hiflory of Aftronomy for 1798. 23 On the 20th of June the Inftitute decreed the prize for time-keepers, ufed_in afcertaining the iongitude at fea, to two chronometers made by C. Louis Berthoud, the going of which was obferved by C. Meffier and myfelf during fix months. I carried one of them to Gotha; and I had the fatisfaction of finding that a journey of two hundred leagues, in a carriage, did not make the change of a fecond per day in its movement. The Inftitute will propofe, on the 4th of January, as the fubjeét of a prize to be adjudged in two years, the theory of the comet of 1770, which was propofed by the Academy in 1792. It has not hitherto been poffible to caleulate this comet but in an orbit of five ans and a revolution fo fhort is improbable. The Memoirs of the Inflitute for the Year IV. have ap- peared. They contain my Theory of Mercury, the refult of forty years refearches. This was the firft memoir read in the firft fitting of the firft clafs of the Inftitute, on the 1ft of January 1796. The Bureau des Longitudes has publifhed two volumes of the Connoiffance des Tems for the years VIH. and IX., the additions to which were edited under my infpeétion. It has determined that this work, in future, fhall contain 500 pages, in order that we may infert in it our obfervations and calcu- lations. Thefe two volumes contain a number of important articles: new catalogues of the ftars; tables of the moon’s horary motion by Delambre; obfervations of Mercury by Vidal, the great and aftonifhing obferver of that planet, to whom we are indebted for being able to fay that the obfer- vations of Mercury, fo rare and fo difficult before his time, are at prefent as numerous as thofe of the other planets, and leave nothing more to be wifhed for on that head. He has alone done more than all the other aftronomers of the world, either ancient or modern; and we may now difpenfe with employing our attention on that fubject. C. Vidal mutt make eyery other aftronomer defpair of exceeding him. 4 An 26 Hiftory of Aftronomy for 1798. An interefting memoir, accompanied with a trigonome- trical chart, ferving to reduce the apparent diftance of the moon from the fun, or from a ftar, to the true diftance, and to refolve other queftions of navigation, has juft appeared, by J. R. Maingon, lieutenant de frigate. ‘This ingenious chart, of great utility to the navy, was engraved by order of the minifter, and publifhed at the dépot. It will fupply the place of the large charts of Margetts, and enable navigators to fubftitute operations with a pair of compaffes for calcu- lation. The Geographical Ephemerides, undertaken by M. von Zach, of Gotha, at the commencement of the year, are a remarkable and ufeful work, as there are found in them every month curious obfervations; information refpecting new books and charts, new voyages and geographical maps, fuch as thofe of Ireland, Africa and the Black Sea, of fo much importance at a time when the public attention is direéted towards thefe countries; alfo portraits, fuch as thofe of Herfchel, Delambre, Sir Jofeph Banks, &c.; in a word, every thing that can be interefting to aftronomers, geographers and navigators. An extenfive correfpondence with all coun- tries enables M. von Zach to form a mutual communication between learned men, even the moft diftant from each other. The only inconvenience is, that the German language is not fufficiently cultivated in the South. I have requefted that a profeffor of German may be eftablifhed in the College de France, as I am fully convinced of the importance of that Janguage to various branches of feience. No journal was devoted to aftronomy and geography; and there was little reafon to hope that any of the kind would be undertaken. Adelbulner and Bernoulli had attempted it without fuccefs. ‘The high efteem in which M. von Zach is held, has given to his work a fufficient degree of reputation to enfure a fale, and confequently the continuance of this ufeful publication. M. Martonfi has publifhed, in Tranfylvania, a defcription of Hiftory of Aftronomy for 1798. 24 of the obfervatory con{ftru&ted by Count Bifhop Bathyani at Carlfburg or Alba Julia, called alfo Weiflembourg and Alba Carolina. M. Triefnecker, of Vienna, has publifhed a confiderable work on eclipfes of the fun and planets. He has calculated more than 150 obfervations, and the tedioufnefs of fuch la- bour is well known. Scarcely any thing of the kind had been done in 1760, when I began to giye an example of thefe calculations. We are informed that a volume of Bradley’s obfervations, fo long expeéted, has been publifhed at London. M. de Mendoza publithed, alfo at London, in 1797, refearches in regard to folving the principal problems of nautical aftro- nomy, with tables of verfed fines for every ten feconds, and an auxiliary table which reduces the difcovery of the true diftance to the addition of five verfed fines. We have received the Ephemerides of Bologna for twelve years, from 1799 to 1810, by C. Mateucci, affifted by C. Alamanni, Guglielmini, Sacchetti, and Canterzani the fon. Since the commencement of the prefent century, the Aca- demy of Sciences always publifhed the Ephemerides for ten years. The laft volumes are by Defplaces, Lacaille and myfelf. I finifhed at the year 1800, old ftyle: the em- barrafled ftate of commerce prevented me from immediately finding a bookfeller, and I therefore renounced thefe cal- culations, The afironomers of Bologna, more fortunate, have fupplied this deficiency; and we fhall have twelve years materials to affift thofe who with to make almanacks for that period. The Ephemerides of Milan contain the refult of an im- portant Jabour of C. Oriani, on the method of correéting the elements of the tables of Mercury by. obfervation ; and many interefting obfervations of C. Reggio and De Cefaris. M. Schroter, of Lilienthal, has publifhed the fecond vo- lume of his Afronomical Colleétions, which, befides other things, contains the apparent diameters of the fatellites : nine- 28 Hiflory of Aftronomy for 1798. nine-tenths of a fecond for the fecond ; nid one fecond and a half for the third. M. Bode, at Berlin, has publifhed a new volume of his Ephemerides for the year 1801, and a third fupplementary volume ; which contain many aftronomical obfervations and memoirs, by the German, French and Englith aftronomers. This work, like that of M. von Zach, is a repertory which no aftronomer can be without. We have received alfo a folio volume of logarithmic tables, publithed in 1794, by M. Vega, an officer of artillery in the emperor’s fervice. Whacq’s tables, publifhed in 1628 and 1633, had become exceedingly fearce; they were never re- printed, and yet. they were often wanted. M. Vega has, therefore, rendered a great fervice to mathematics by re- publithing that valuable edition. M. Schubert has publifhed, in German, at Peterfburgh, a large treatife of aftronomy, in three volumes quarto, form- ing altogether nearly goo pages. The Bibliotheque Britannique of Geneva, for March and April, contain interefling details refpeGting the method em- ployed by M. Blair to correct the difference of refrangibility in telefeopes. Effential oils, a folution of corrofive fublimate in fpirit of wine, with the addition of a little fal ammoniac ; butter (muriat) of antimony diluted in a little ether or alceahol, mixed with a few drops of the muriatic acid, anfwered the purpofe extremely well, when inclofed be- tween two lenfes of crown glafs*. He formed a very good obje& -glafs with a folution of fal ammoniac and mercurial fublimate (muriat of ammonia and mercury). He has dif- covered that thefe different fubftances have not a like diftri- bution of colours, as Bofcovich remarked in 1765. In fhort, he has calculated the curves ef glafles in fuch a manner as to corre&t the aberration of fphericity. This curious paper has been tranflated into French; but C, Leroy has kept * Tranfadtions of the Royal Society of Edinburgh, vol. iii. back ee os Hiflory of Aftronomy for 1798. 29. back the manufcript for three years. We are obliged to C. Piétet for having made it known in his excellent collection the Bibliotheque Britannique: the author calls thefe tele- {copes aplanatic, or without error. I have publithed a new edition of Rivard’s Treatife on the Sphere and the Calendar; a well written elementary book, which has been ufeful for half a century. I have added to it the Republican Calendar, remonftrating againft the defi- ciency of intercalation, as the decree of Oétober the 3d 1798 was not in that refpect agreeable to what I had de- livered to C. Romme. C. Francois de Neufchateau fignalifed his entrance into the miniftry by ordering an Aftronomical Bibliography to be printed. I brought with me from Germany a great many articles for this work; and I have found that no kind of bibliography can be complete without the co-operation of many perfons in different countries. The period of the death of the great Copernicus was ftill a problem, which I refolved during my journey. He died on the 11th of June 1543, though Gaffendi and Weidler fay the 24th of May, and Planche the 11th of July, in the interefting collection of Ephemerides, where the memorable events of each day are recorded. I have caufed more than fixty manufcripts to be examined in the national library. C. Legrand, one of the librarians of that celebrated repofitory, gave me an ac- count of many others; fo that we are making advances in this part of aftronomical erudition. We have received the obfervations of C. Ratte at Mont- pellier, C. Thulis at Marfeilles, and C. Vidal at Mirepoix thofe of the laft-mentioned aftronomer. are of a very extra- ordinary kind. C. Vidal faw Meréury at the diflance of three-fourths of a degree from the fun. The beauty of the climate, the perfection of his inftrument, and the excellence of his fight, have produced obfervations as valuable as fingu- lar: I have fpoken of them before, vise High wy ane 30 Hiftory of Aftronomy for 1798. The direction of the obfervatory at Amfterdam, belonging to the Society Felix Meritis, has been entrufted to M. Cal- koen. He has been at Gotha to exercife himfelf with M. von Zach; and has begun a courfe of obfervations which will be ufeful in a country where none were ever made, though the want of a navy muit induce the government to open their eyes in regard to an object fo neceffary to navi- gators. In vain did I go to Amfterdam in 1774; the Stadt- holder and the Grand Penfionary promifed every thing I wifhed, and did nothing. M. van Swinden afterwards made fome exertions, the effects of which begin to be felt. C. Henry, who went from Manheim to Peterfburgh, has been able to reftore activity to the obfervatory of that capital. He has caufed to be erected the large mural quadrant by Bird, which had remained a long time in the packing-box, and which Rumoufki never made ufe of. M. Piazzi, the aftronomer of Palermo, is preparing to meafure a degree. I have fent him an exa& metre, and they are employed on a complete circle. The minifter, Pleville-Peley, has increafed the falaries of the aftronomers belonging to the marine obfervatory at Marfeilles, where Thulis makes continued and important obfervations, The furvey of Corfica, or defcription of that ifland, begun thirty years ago, has been finifhed. The large triangles were laid down by C. Tranchot; the minuter operations were performed by a great number of affiftants. The minif- ter of finance having commiffioned me to examine this labour, I have reafon to think that it is fufficiently corre& to be taken as a model, fhould a like plan be adopted in re- gard to all the departments of France, which would be highly ufeful. C. Perny, who had been fent to Belgium, and who, fince 1795, has formed forty triangles at Bruges, Ghent, Oftend, _Antwerp, Middelburgh, &c. has fet out for the Batavian republic, Hiflory of Aftronomy for 1798. 31 republic, which promifes to furnifh him with every thing neceflary for continuing that labour. On the 24th of January the Inftitute propofed to the Dire&ory to requeft the different powers of Europe to fend learned men to France, to affift in eftablifhing the new meafures, and to fanction that eftablifhment. Eleven have arrived from Denmark, Spain, Italy and Holland: from Denmark, M. Bugge, director of the obfervatory, and known by fome important works; from Spain, Meflrs. Gabriel Cifcar and Auguftine Pedrayes; from the Batavian republic, C. van Swinden and Ainez, the former well known by fome excellent works on natural philofophy; from Tufcany, M. Fabbroni; from Sardinia, Count Balbo, the minifter at Paris; from Helvetia, C. Tralles; from the Ligurian re- public, C. Moltedo; from the Cifalpine republic, C. Maf- cheroni, from whom General Bonaparte brought us what will ferve as a leffon to our moft famous geometricians ; and from the Roman republic, C. Franchini. On the 23d of June the legiflative body made a law, that the Bureau des Longitudes fhould preferve the original ftand- ard of the metre, or of that new meafure deftined to be in future the type of all meafures, and to prevent hereafter that confufion which has hitherto prevailed in ‘the meafures of all countries. Aftronomy has fo few profelytes that I am happy in being able to fay that Dr. Burckhardt, who came from Gotha laft year, continues to labour with us at Paris, and that he is already one of our belt aftronomers. Delambre had as affiftants in his immenfe labour C. Tranchot, already well known by the great operations in Corfica, and young C. Pomard, who devotes himfelf to aftronomy, and who cannot fail to make a rapid progrefs under fuch a mafter, Aftronomy has need of a few recruits; and I do every thing in my power to procure them; but the career is Jaborious, and not lucrative: this is fufficient to ‘explain why we haye fo few. Blanpain, 32 Hiftory of Aftronomy for 1798. Blanpain, born in 1779, who faw firft at Marfeilles the eomet of 1797, announces, at the age of nineteen, as much zeal as knowledge. He is diflinguithed by his great learn- ing and good moral qualities. Being obliged to apply to commerce, he is not yet able to indulge his tafte for aftro- nomy; but he calculates obfervations, and even makes fome himfelf. Young Bernier, of Montauban, applies alfo to the fame feience with fuccefs. I wifhed to get him fent out with General Bonaparte; but my application was too late. C. Cotilon, though employed in the adminiftration of domains, has come to lodge in the College de France, in order to labour along with us. His intelligence and zeal we often find ufeful. On the 11th of November C. Caffini V. aged fixteen, who has come to refide in the obfervatory to purfue the traces of his anceftors, and who difplays all the zeal which ought to be infpired by fuch an illuftrious name, made his firft obfervation in the obfervatory of the College de France, under the diretion of C. Lefrancais. He will fupply the place of Maraldi IV. who has left us. After having fpoken of our acquifitions, I muft now fpeak of our loffes. In the hiftory-of aftronomy for the Year V. I announced the death of Toaldo, which happened at Padua on the 18th of November. As I publifhed a particular eloge of that ufeful aftronomer in the Magazin Encyclope- dique*, 1 {hall here add nothing on the fubject, except that his place is fupplied in the obfervatory of Padua by his nephew, M. Chiminello, who was a long time his affiftant. Bertrand-Aueuftin Carrouge, an aftronomer of_ great merit, died on the 2gth of March. He was born at Dol on the 8th of O&ober 1741. He calculated a thoufand ftars for the Celeftial Globe publithed by C. Lamarche, fucceffor to Fortin; and he made a great many calculations for the * Vol, vi. p» 469. é Connorffances Hiftory of Aftronomy for 1798. 33 Connoiffances des Temps, and the fecond edition of my Aftronomy. He publifhed feveral memoirs in the Coz- noifjances des Temps; and a few days before his death he delivered to me tables for calculating the phafes of the moon, better than thofe which are in Bouguer’s and La Caille’s - Elements of Navigation. They are in the Connoiffances des Temps for 1801. He was exceedingly poor when he was appointed adminiftrateur general des pofies on account of the efteem which Reveilliere-Lepaux, the direCtor, had for his’ merit. His new appointment did not prevent him from applying to aftronomy: talents rarely conduét to for- tune; this only happens when power is united with know- ledge. Alexis John Peter Pauéton died on the 15th of June. He was born on the roth of February 1732, near Luflan, and is known by his Metrology, an immenfe collection of the meafures of all countries, which appeared in 1780. I pro-* pofed that labour, and furnifhed him with the greater part of the foreign meafures ; but he added many refearches, dif- fertations, and calculations refpecting the ancient meafures, population and agriculture. He employed himfelf on other parts of the mathematics, fuch as the Screw of Archimedes. In the year 1781 he publithed a Theory of the Laws of Nature, in which he refuted Newton and Nollet, and efta- blifhed a new geometrical foot of 123% lines. In that work he {poke of the pyramids of Egypt, &c. He was fo fully perfuaded of the importance of his difcoveries, that he af- fumed this motto: E puteo veritas. In the Jaft place, he was employed in reducing into decimal meafures the im- menfe number of foreign meafures, when the economy of government fuppreffed his falary, and ‘plunged him into _wretchednefs and defpair, which terminated in his death. The Inftitute is juft how foliciting government to grant fome relief to his widow and children. Beauchamp wrote to me, from Arles, that he had loft his Vou. IV. D “ brother, t a 34 Hiflory of Ajironomy for 1798. brother, the companion of his travels through Arabia; andé his pupil Hyacinth Receiveur, who difplayed all that zeal and all thofe good qualities which could be wifhed. This lofs, a very great one to aftronomy, threw Beauchamp into defpair, and difgufted him with a veyage to Arabia; but the minifter fent him to join Bonaparte and the men of letters affembled in Egypt, where he will certainly contribute to the fuccefs of that important -expedition, in regard to the geographical and aftronomical parts. M. Reccard, who had publithed various obfervations, died at Konig{berg on the 3d of October. We have loft lately alfo John Francis Calle. He was born on the 25th of Oétober 1744, at Verfailles, where he received a good education, and acquired an early tafte for the mathematics. In 1768 he came to Paris, where he had an opportunity of being more thoroughly inftruéted. In 1774 he formed fome diftinguithed pupils for the fchool of engi- neers, where the examinations were firict, and admiffion difficult to be obtained. In 1779 he gained the prize pro- pofed by the Society of Arts at Geneva, for efeapements. Tn 1783 he completed his edition of Gardiner’s Fables of Logarithms, which were exceedingly convenient, of great utility, and very correét; and which poffeffed advantages’ above all the others. In 1788 he was appointed profeffor of hydrography at Vannes, afterwards at Dunkirk ; and in 1792- he returned to Paris, and was for a few years profeflor des ingenieurs geographes at the depét of war. This place hay—- ing been fuppreffed, he continued to teach in Paris, where he was always confidered as one of the beft mathematical -mafters to whom pupils could apply. In 1795 he publifhed the new ftereotype edition of the Tables of Logarithms, confiderably enlarged with logarithmic tables of the fines, according to the new decimal divifion of the circle. Thefe are the firtt which ever appeared. Towards: the end of 1797 he. prefented to the National Inftitute the , plan ° 4 bY ial Y é On Dr. Miichill’s Theory, &c. as plari of a new telesraph, and a telegraphic language, accom- panied with a dictionary of 12,000 French words adapted to it by a combination worthy of fo able a mathematician. Thefe labours had injured his health; he had been a long time afthmatic, and notwithftanding his condition he pub- lifhed, that year, an excellent memoir on finding the longi- tude at fea, under the modeft tithe of 4 Supplement to the - Trigonometry and Navigation of Bexout.. He died on. the 14th of November 1798, leaving behind him a daughter, born at Vannes in 1793. According to a tradition in the family, he was defcended from Defcartes. I have not been able to obtain the genealogy of his family; but it is fufficient for the glory of Calle, that he has done honour to a name fo celebrated. VI. Progre/s of Dr. MircH1L1’s Mind in invefligating the. Caufe of the Peflilential Diflempers which vifit the Cities of America in Summer and Autumn. Being a Developement of bis Theory of Peftilential Fluids, as publifbed to the World mm 1795, and the fucceeding Years*. It had a Jong time appeared to him, that what had been mentioned by medical writers and lecturers under the names of miafma and contigion, was not treated of with the pre- eifion and certainty of knowledge, but difeuffed with all the indiftinétnefs and conjecture of fomething only gueffed at. And, while a ftudent at Edinburgh, he fuppofed the doctrine taught in the univerfity of the /edative operation of thefe poifons was true, until he heard from Dr. Brown, while at- tending his leétures, a contrary opinion. Delivering his fentimients on /timulants, Brown had faid, ** Venena et contagiones incertits eddem fpeétant.”’ (Ele- menta Medicine, cap. 2. § x1.) This implied a doubt in Brown’s mind, whether thefe clafles of objects were ftimu- * From an American Correfpondent. D3 lants 36 On Dr. Mitchill’s Theery Jants or not. This doubt is repeated in § x1x. where, ex- prefling his ideas of the manner the exciting powers act upon excitability, he feems to confider poifons and contagions as exceptions to the general rule of action: ‘ nifi quod venena et contagiones excipi pofle videntur.”” And although, in the two following paragraphs, he endeavours to {hew that thefe fubftances are /mulanis, and aét upon the living body after- the manner of other ftimuli, ftill he is fo wholly filent as to their nature and conftitution, and fo entirely deftitute of ex- perimental proof or demonftrative reafoning, and withal fo brief and general in his remarks, that nothing folid and fatif- factory is afforded in that part of his work which treats of thefe matters. In converfation with this original though unfortunate man, Dr. Mitchill acquired incorrect information on the matter of thefe poifonous fubftances and their manner of acting; the fum of Brown’s reafoning but tending to fhew that, as all other fubftances according to his hypothefis were ftimulants, poifons and contagiors could not, from the nature and analogy of things, at in any other way than by ftimu~ Jation too. Thus it appeared to Dr. Mitchill, when he returned to America in 1787, that that field of phyfical fcience, which included the production, operation, and extinguifhment of poifonous fluids, lay almoft wafte and uncultivated. On turn- ing over the Encyclopedia, there fcarcely appeared a fubject whofe inveftigation promifed greater good to mankind, or furer fame to the inveftigator, than the hiftory of thefe nox- ious productions. Not long after this time the Medical So- ciety of the State of Delaware propofed a prize-queftion, ‘© \What was the hurtful power which produced the febrile diftempers of that region?”? And Dr. Mitchill was folicited - by his friend Dr. Ed. Miller, then fecretary of the fociety, ta compete for the prize. But being at that time engaged in the ftudy of the law, and alfo in the politics of his coun- try as a member of the legiflature, he declined undertaking ' any gets oe of Peftilential Fluids. 54. any thing of the kind; but obferved, ** that the mifchievous matter would be found to le a gas, and an analyfis of a portion of the atmofphere there would not fail to detect what fort of gas it was.” _ Being devoted to other purfuits, the fubje& of poifons hardly occurred to him afterwards, that he recollects, as a theme for contemplation, until the year 1795, when the following incidents fet him ferioufly to thinking. While on a tour, that fummer, towards the northern country, he had afeended towards the fources of the Kaats-kill, and been engaged among the fublime and picturefque {cenery of the Blue Mountains, in the State of New York. Ona {fhoulder of the eaftern fide of a ridge, called the Pine Orchard, he very narrowly efcaped being bitten by one of the raitle- fnakes which infeft that zone of the mountains. This fer- pent, of the full-grown and largeft fize, lay bafking in the fun-fhine. The voyager had walked within a foot and a halt of him before he was difcovered. The agitation and whiz- zing noife of his rattle led firft to his dete&tion. When feen, he was bent into a coil, and his head was erected apparently to ftrike. The fuddennels of the furprife, and the grand and novel afpeét of the animal, prevented for a moment tlie emotions of fear. Dr. Mitchill, however, was foon brought to his recolleétion by the cries and fhouts of his companions, who were terrified at the extremity of his danger. In the mean time the animal crept quietly away, and Dr. Mitchill efeaped unhurt. By the joint efforts of the company, this ferpent and his mate were drawn from their lurking-place and killed, In the diffection of their bodies, in which he was aided by William Cutting, Efq. and others, Dr, Mitchill had an opportunity of examining their fangs, jaws, and re- ceptacles of venom. So narrow an cfeape, as it induced him to reflect, led him afterwards to conclude, that there was very little of philofophical information to be derived fram Mead’s Mechanical Account of Poifons; and that in D 3 Fontana’ 65 On Dr. Mitchill’s Theory Fontana’s Experiments, the general exciting caufe of plague and peftilence had been left unexplored. Another occurrence, during that excurfion, had directed his attention to the fubjeét of poifons. Dr. William M. Rofs, one of the party, had difcovered that the Rhus Toxico-_ dendron grew at the foot of the Blue Mountains. Anda parcel of the leaves and ftems of the plant were collected and carried home, with the intent of repeating Alderfon’s . experiments with this yenomons vegetable, on perfons af- flicted with palfy. From this tour as he was returning to the city of New York, he learned with forrow at Paughkeepfie, a town eighty miles diftant, that a malignant diftemper had broken out during his abfence, and that among other perfons Dr. Mala- chi Treat, then phyfician of the port, had been carried off by it. Haftening back with all fpeed, he faw and converfed with a number of phyficians, and found them divided in opinion, whether the yellow-fever, for fo the difeafe was called, exifted in the city or not. The majority feemed dif- pofed to doubt or deny the fact. A fhort time, however, was fufficient to convince all perfons whatever, that a fad and terrible malady had made its appearance among the in- habitants. Impreffed as he was with ideas about poifons, it appeared to him at once, that the exciting caufe of the endemic fick- nefs of New York, was as much a poifon as the fluids fecreted by the rattle-/nake or the toxicodendron. There was a dif- ference, however, between the venom of peftilence and the poifons firictly denominated animal and vegetable; becaufe the two latter were always the effect of vafcular and glandular. aétion with fecretion in living bodies ; whereas the former was the refult of new combinaticns taking place in organized fubftances during their putrefaction and decay, without any. thing like a fecretory function. Herein, then, feemed ta confit the diftin@ion begween what might be called Com- MON 3s! “2 « we - of Peftilential Fluids. 3% 4r0Nn Porson and Speciric Porson; the one being pro- duced by the corruption of dead bodies, the other afforded by fecretion goimg on in living ones. The decifive method of gaining information concerning this Common Porson (venenum univerfale) mutt necef- _ farily be an examination of every individual procefs going on during the complicated work of animal and vegetable difor- ganization. For this purpofe Dr. Mitchill had planned a fet of experiments. But, before undertaking thefe, he de- termined'to watch the operation of the poifon already pro- duced, be it what it might, and ‘obferve in what manner it wrought the deftruction of life. And, for this purpofe, he remained in the city until the ficknefs was abating ; having omitted no opportunity to witnefs and colleét facts as they occurred in the midft of peftilence_and death. Much obfervation, and in circumftances where the per- fons beft calculated to make refearches in fcience rarely choofe to expofe themfelves, had led Dr. Mitchill to believe that the hiftory of azoTx, both in living and dead bodies, would throw a world of light upon this department of phy- fics. Accordingly he went to Plandome,. his country refi- dence on Long Ifland, and became convinced, by experi- ments made on the air extricated in the abdomen of putre- fying animals, that it was not merely carbonic acid gas, but confifted alfo of a large quantity of azotic air, It is remark- able, that, to avoid the obloquy too often levelled at experi- ments, he was obliged to condué his proceffes with all pof- fible fecrecy. But azotic air alone feemed to poffefs too little adtivity to excite the horrid fymptoms which conftituted and charac- terifed the diftemper he had fo lately witneffed. Yet he knew, and there was no need of any new experiment to prove it, that this very azote did not always evaporate with caloric in the form of air; but in higher degrees of heat than that of Oétober, when his experiments were made, this acidifable ba/is frequently connected itfelf with oxygen, and conftituted Da a very 40 On Dr. Mitchill’s Theory a very peculiar and deftructive acid. Such an acid poifon, he became perfuaded, had deprived Mr. Hewfon, Dr. Walth, Mr. Jones, and other diffectors, of their lives, by being ad- mitted to a furface denuded of fkin. Dr. Latham’s fact of the fervant poifoned by touching an agnail on his finger with the fleth of a putrid hare which he was fkinning, is of the fame kind. Immerfion of thefe carcafes in ftrong folutions of alkaline falts, or the mere f{prinkling them with pot-afh or foda, would, he thought, have prevented thofe unpleafant accidents. In fuch cafes the product formed. by the chemical union of azote with oxygen, mingled with more or lefs of water, and exifting in a liquid form, poifoned only when the parts. of a living animal were brought into contaét with it, as it befpreads the furface which produced it. But Dr. Mitchill was convinced, that, in higher temperatures, whem the furface of the earth was heated to 116 deerces, and even to 130 of Fahrenheit’s feale, this liquid poifon took on occafionally a vaporific. or aérial form, and was copious enough fometimes to taint or infect a chamber, a houfe, a neighbourhood, or even acity. In the former cafe it injured none but thofe who meddled with it, in the {pots where it was produced ;_ in the Jatter it rofe into the atmofphere, and fallied forth in queft of prey, to diftances indefinitely remote, About this period of the inquiry Dr. Mitchill made an excurfion through a part of the State of New York, in con- fequence of an appointment from the Society for promoting Agriculture, Arts and Manufatures, to explore the natural produétions of the country, and efpecially to determine whether any mines of coal exifted in the neighbourhood of Hudfon’s River. It did not appear that any confiderable quantities of that article of fuel were to be found; but it was afcertained, in the courfe of the expedition, that, in fome of the manufactories, where the alkaline falt of burnt-wood is extracted to form the pot-afh and pearl-afh of commerce, tuere was enough of oxygenated azote in the atmofphere ta combine aa ae of Peflilential Fluids, 4 combine with a portion of the alkali cryfiallifing about the letch-tubs, and to conftitute falt-petre. The labourers at pot-afh works, though much expofed to night air, were fel- dom vifited by the ordinary fevets ef the climate. . His attention being thus called to the properties of alkalis, was foon engaged in a more minute inveftigation of the hif- tory of pot-ath, by the following incident. Dr. Mitchill re- ceived from the Chamber of Commerce’ in Glafzow, a lette complaining of the bad quality of certain barrels of pot-afh and pearl-ath exported from New York under the infpector’s brand, and proved by the bleacher at Paifley, to whom it had been fold, to pofiefs hardly any qualities for whitening goods. This letter was accompanied with a notorial copy of the pro- ceedings in a fuit at law brought by the bleacher at Paifley, plaintiff, againft the commiflion merchant in Glafvow, de- fendant, for damages on account of having fold him unmer- ehantable alkali; in which the Court gave judgment for the plaintiff. ‘Thefe papers were fubmiitted to the Chamber of Commerce in New York. In confequence of this, Dr. Mitchill was requefted by the prefident of that body, a fhort time after, to vifit with him the ftores of the public infpeétors of pot-afh and pearl-afh in the city of New York. Among many other faéts which were collected during this vifitation, it was related by the infpeétors, that, while the labourers in the pot-afh ftore kept themfelves at home and were within the influence of the alkali, the peftilential air of the city had not affected any of them with difeafe; and Dr. Mitchill dif- covered afterwards, that if thefe very labourers expofed them- {elves to the noxious gas in the air abroad, they fickened and died like other people. While thefe things were under confideration, the Legifla- ture of the State aflembled. At that time there was con- fiderable converfation throughout the United States concern- ing the internal and domeftic means of defending the country from invafion by a foreign enemy. A man appeared with a project for fetting up a manufacture of falt-petre in the neigh- 42 On Dr. Miichill's Theowy, Cc. neighbourhood of the city of New York. On this project Dr. Mitchill was confulted. The man’s intention was to have petitioned for the privilege of having the dirt and ferapings of the ftreets as a reward for keeping them clean. And from this mafs of nuifance, whofe vapour in the hot feafon gave the people their yellow fevers, he intended to ex- tract the nitre. After much confideration of the project it was finally given up, as about that time the Secretary of State reported to Congrefs that a confiderable quantity of that material had been brought to Philadelphia from fome part of the weftern country, and that any quantity required for the public defence might be procured from that quarter. From a comparifon of all the faéts which had thus come to his knowledge, Dr. Mitchill found that fome of the prin- ciples m which he had been inftruéted, were not fo well eftabliflied as they ought to have been, A number of the darling prejudices of his education were in danger of being | overturned. And he, for fome time, experienced no {mall degree of affliction at the thought of rejecting much of what _ he had learned from books and le&tures, concerning acids and alkalis, as groundlefs and untenable doétrine. The fluids, whether liquid or aériform, which ot-a/b could coerce, and which, as they emane from putrefying bodies, combine with that alkaline falt into nitre, thus ap- peared: to be the very noxious miafmata which vitiated the atmofphere and rendered it fickly and unwholefome, when there was too little alkali or none at all to attract them, Thefe feemed to be evidence enough to convince him, and any body elfe who would examine thevfacts as he had done, that fome combination of azote with oxygen was the fimpleft and moft common form of poifon. At the fame time he was perfectly aware that what he thus called a poifon, was what mankind knew under the name of the witrous acid ; that nitre was called a great anti- Jeptics that the avid was clatled among the mineral acids, and was reckoned a great antifeplic too; with a multitude of fay- 3 ings ’ . : oe, + . On the Manufafure of Crude Iron, A3 ings of this fort. _ He therefore apprehended that the old and _tigid adherents to thefe names, and to the modes of thinking affociated with them, would {carcely have patience enough to liften to any modernifed, or, as they would term it, new- fangled ftatement of the facts. This difficulty was the more formidable, as it was found neceflary eventually to make an innovation upon the French nomenclature itfelf. To facilitate his own conceptions of things, rather than to affe&t novelty or attract profelytes, and alfo to render his ex- preflions of thefe things more correét and eafly, he propofed what he deemed an allowable amendment to.the nomencla- ture, by expunging azole, axzotic, nitrous, nitric and their derwatives, and taking /epton for the radical term, with fep- tous, feptic, &c. as the preferable epithets. He conceived he had a right to make ufe of a nomenclature of his own, if he pleafed; while others, if they preferred it, were at liberty to adhere to the old one. [To be concluded in next Number. ] See VII. On the Ufe of Calcareous Stones in the Manufacturing of Crude Iron. By Mr. Davip Musuet of the Clyde Tron Works. Communicated by the Author, ‘T . HE tenacious lava which is formed when iron ores or iron ftones are fufed without the addition of any other fub- ftance, firft led to the application of calcareous earths, in various proportions; that a fluid fufficiently thin and divided might be. formed, and the iron difengaged from its vitrid connections, precipitated to the bottom of the furnace. If the nature and mixture of the ore are well underftood, the quantity of lime neceflary to reftore a juft equilibrium of pro- portion in the lava will be readily attained; the metal, no Jonger incorporated with or fufpended in the mafs, will be- gome completely revived, and flow from the furnace fuffi- ciently purified from its earthy mixtures, Pete Before 44 On the Ufe of Calcareous Stones ‘in Before this principle was underftood and generally acted upon, the refult in iron, from a given quantity of ore, mutt have been very uncertain, and its real value in the fmelting furnace falfely appreciated: even at this advanced period of improvement, and attainment of fcientific knowledge, it is much to be doubted if the principle of application of calea- reous earths, in the blaft furnace, is radically underftood. If an almof total want of knowledge concerning the na- ture, proportions, and variety of the earths united to the ores, prevail at the various manufactories of iron in Britain, we are not to wonder that the application of lime-ftone is fubject to great error, and productive of hurtful confequences. In the fmelting procefs the three great fprings of action and government in the’ manufacture ought to be—a com- plete revival of all the metal contained in the ore—to confer value upon it, by reviving it faturated with a fufficient quan- tity of carbon—and to ufe every endeavour to increafe the quantity: ftill, however, keeping in eye the produce of iron from the ore, and its quality; both of which may be eafily impaired by too much eagernefs after quantity. To deprive an ore of its iron, fo that no portion of it fhal] efcape in the fcoria unrevived, two things are indifpen{ible : 1. The metal contained in the ore mutt be prefented to a portion of fuel fufficient to take up the oxygen from the metal. 2. As this revivification gocs on in the manner of a metallic perfpiration upon the foftened furfaces of the ore, another agent ought to be prefent to facilitate the feparation, by uniting with the earthy parts of the ore; forming a thinly divided lava, no longer capable of retaining the globules of metal, or of preventing the congenial affinity of the carbonie principle from taking full effect for the improvement of the quality of the iron. Experience has fhewn, that an _excefs of any particular earth may be corrected by applying one oppofite in its effets; and that the addition of lime, in various proportions, js found in moft cafes to anfwer the defired end: this once underitood, the Manufacture of Crude Iron. 45 underftood, it will be eafily comprehended, that as iron ftones and ores pollefs widely different proportions of mixture, their fufion will be productive of vitrid feoriz, various in their degrees of divifion and tenacity. This leads to a conclufion, the juftice of which cannot be doubted, that fince the various mixtures of iron ores are productive of lava, which tends more or lefs to keep the iron from feparation, it becomes a neceffary ftudy to obviate the imperfections of fuch mixtures, and at all times to reeulate the proportion of the calcareous earth, from a knowledge of thefe mixtures and their effects, and not from an implicit reverence to the cuftoms of a fenior eftablifhment. | If the various claffes of iron ftones are fufed in contact with charcoal, without the addition of a flux or folvent, the refult is, from calcareous iron ftone, a larger portion of iron proportioned to the intrinfic richnefs of the ore, than from argillaceous iron ftone; and from the latter, a larger produce of iron, than from an ore whofe chief mixture was filex: the {coria produced in the refpective operations always demon- ftrates, from its colour and opacity, the probable quantity of iron which ftill remains to be taken up. ‘There are fome calcareous iron {tones which contain lime almoft fufficient to form the neceffary quality of fcoria, the colour of which, when freed from the metal, poffeffes a con- fiderable degree of tranfparency. When a number of thefe iron flones are ufed in the blaft furnace, a much lefs quantity of calcareous earths is neceflary. It fometimes happens at iron works, whofe chief fupply is derived from a calcareous field of iron ftone, that, by ufing a great proportion of an in- dividual ore furcharged with lime, the operations of the furnace are ob{tructed, and confequences entailed fatal to the intereft of the manufaéturer. From an excefs of pure calca- reous earth being prefent in the furnace, the fcoria, thick and curdled, becomes attached to the fides and bottom of the ‘furnace; the quantity hourly increafes, till it has accumu- Jated to fuch a degree as to intercept the afcent of the blaf, 7 and 48 On the Uje of Calcareous Stones int and the defcent of the materials. Fhe fource of this evil is juftly attributed to the nature of the iron ftone; but in place of attempting to obviate its imperfections of mixture, it is either totally rejected, or ufed in the moft {paring quantities : whereas, had the quantity ‘of calcareous earth been propor- tioned to that contained in the iron ftone, the fame ore might have been advantageoufly fmelted, and a confiderable quan- tity of lime faved. The fame happy effeéts might alfo have been produced by combining with the calcareous iron ftone, one containing a large proportion of clay or fand; in fome fitnations, where a variety of lime ftones are found, the fame confequences may be effected by applymg one lefs pure, mixed with a proportion of elay and filex.. A fimilar excefs of clay in the argiflaceous genus of irom ftones, is fraught with the fame fatal effects to the produce in metal from the blaft furnace; and manty fuch ores of iron are totally rejected, merely becaufe their improper application was found produttive of confequent effects. The fufibility of lime and clay, individually, is much facilitated by the ad- dition of fand; and in all cafes where thefe earths exift to’ excefs in the ores, they ought either to be combined in the blaft furnace with filiccous iron ftone, or treated with a lime ftone containing a confiderable portion of fand. Again, inftances occur in the manufacturing of crude irony where ores fufficiently rich in irom are totally rejected, sas’ being incapable of affording a quality of crude iron for the purpofe of melting. It is found that an excefs of fuch irony ftone always changes the colour of the fcoria, and that a eonfiderable portion of the metal goes to effectuate this change in the {tate of an oxyde united with the fufed earths. Thefe ores are of the moft fufible nature, combined with 2 heavy proportion of filex; but' {till capable of being treated in fuch.a manner as to afford their iron of a valuable quality. When this mixture is fully afcertained, the fufibility of the iron ftone is little impaired, and the quality of the iron - mended with an increafe of quantity. 5 Fron: the Manufafure of Crude Troz: 47 From this it will appear evident, that the addition of cal- ¢areous earths, in jult proportions, will form with moft ores a vitrid alloy, thinly divided, and to which the metal has fo little affinity, that it becomes abandoned by the former at an early ttage of feparation, and, being expofed to the combina- tion of the carboy, is beneficially and richly revived. In this operation lime may be confidered as introducing into the furnace a confiderable quantity of carbonic acid, [it is always ufed in the raw ftate] which becomes decompofed in fuch a manner as to furnifh the iron with a fmall portion of carbonaceous matter. The effects of this extenfion of prin- ciple are however much limited, as the carbon afforded by the decompofition of the carbonic acid cam never enable the iron to take up this principle from it im a crude concrete ftate, capable of conftituting fufibility. It may, however, by uniting to it in a neutral ftate, call it into metallic exiftence, and enable the carbon afforded by the fuel to diftribute its fufible principle over a larger portion of metal. Lime-ftone therefore ought never to be confidered as a general fubflitute for fuel in the blaft furnace, though m fome cafes the effects produced by its application are fimilar. Its influence extends no farther than to correé the unequal mixtures of fome ores, and facilitate their feparation and carbonation ; an improper application of its kind or quantity may be productive of evils of as great magnitude as thofe it was meant to remove. In no cafe where a juft proportion of ores and mixtures exift in the furnace, and where the refult from a real fearcity of fuel is oxygenated iron, can the addition of lime confer car- donation to the metal. Thefe faéts render the application of lime-ftone a matter of attention, and not of chance, depending on an accurate knowledge of the component parts of the ores and their. effects, and not om certain portions being cuftomary at works of fimilar eftablifhment. When a fearcity of lime exifts im the blaft furnace, and a fuperior quantity of clay and \ 43 On the Uje of Caleareous Stones in and filex is combined with the iron ftones, the lava will flow from the furnace comparatively cold, tenacious, and of & brown or pale dirty green colour, containing iron: when the mixture is juft, the colour of the fcoria is pure white, enamelled with a variety of blue fhades, waving, circular, or formed in ftraight delicate lines, arifing from a peculiar ex- ifting modification of a minute portion of the metal. Should lime be added in excefs, the quality of the iron will not be improved, but the quantity confiderably diminifhed. This lofs takes place in two ways; when the iron is oxygenated, the prefence of an extra quantity of fufed earths facilitates the oxydation of the metal, whenever it comes into contact with atmofpheric air*. The ftrong current of air from the difcharging pipe affords ample opportunity for this oxyda- tion; the fmall globules of metal deflagrate and become combined with a great portion of oxygen ; the want of car- bon in the furnace prevents any part of the oxygen from being again removed; the oxydated iron incorporates with * As I have frequent occafion to ufe the two verbs, to oxygenate, and to oxydate, I fhall exprefs the precife meaning I attach to two: words which are fometimes indifcriminately ufed, and to which it has been thought that M. Lavoifier had affixed no feparate or diflinét meaning. 1 have ufed oxygenate to exprefs the progreflive combination of oxygen’ with: the metal, without, however, deftroying its metallic fraéture, or exhibiting internally the fimallett appearance of an oxyde. Oxydation, on the other hand, I have always ufed to exprefs the final confequence of the combina- ticn of oxygen with iron, and the complete change from a metallie ftate, to that of a detached friable oxyde. For example, crude iron run from the furnace, of a white fracture, is faid to be oxygenated. In cooling, being expofed to atmofpheric air, it acquires a confiderable quantity of blueifh oxyde; its furface may then juftly be faid to be oxydated. It is. the fame with malleable iron and ftecl; each of thefe fuffer in quality from the affinity oxygen has to combine with them, at a high temperature, before the leaft diminution of metallic fraéture takes place; and in that flate I have always confidered them as oxygenated. When, however, this was paft, and the combination of oxygen had deftroyed every property of metal, [ have confidered this only as a fate of oxydation. the the M. anufactire of Crude Iron. 49 the fcoria floating upon the furface of the precipitated metal, changes its colour, and in iffuing from the furnace conveys a complete change of form and depofition. Should it, however, happen that an extra quantity of lime is added when the iron is already richly carbonated, then the nictal loft is no longer in the ftate of a fiifed oxyde incorporated with the fcoria, but in fmall metallic globules, completely enveloped, unable to penetrate the cturdled mafs and fiiid their Way to the bottom of the furnace. This curious pheroine- nori arifes froni the pectiliar nature of fufed calcareous earth, which, while it poffeffes no great degree of tenacity asa fluid, yet forms a confiftency through which iron with all its fupe- rior denfity is not able to penetrate: when cold, fuch fcorize have no appearance of vitrification, but are of a ftraw colour, tough fracture, and very ponderous. I have fome fpecimens of this feoria, obtained from the blaft furnace, with triple firata of regularly depofited globules of fuper=carbonated crude iron, from half an inch to the fmalleft diameter. The {trict analogy exifting betwixt lime ftones and ores, in the variety arid proportions of the earths combed with each, renders the inveftigation of both equally necefiary, and requifite to be performed in connection with each other. There are advantages to be derived from a thorough knowledge of the component parts of iron fiones, which may not at firft fight flrike the manufacturer: where a variety of fituations offer, this knowledge will dire&t him to an eftablifhment where the iron ftones are of a nature ‘moft likely to fuit his views. Where melting pig iron for fale is the chief obje&, calcareous iron fiones mixed with filex and nearly deftitute of clay poflefs the greateft advan- tages. Iron made from this clafy of ores never poffefles any great degree of ftrength; this, however, in the cafting bufi- nefs in general, is reckoned its greateft property ; it becomes fufed with lefs fuel, lefs wafte of metal, and the articles made from it exceed thofe made from ftronger iron, in the {moothe _ nefs of their furface and in the folidity of their parts. Vou. IV. iD _ Analogous a 50 On the Ufe of Calcareous Stones Analogous to thefe facts, we daily fee the fuperiority of fituation evinced, and ceteris paribus larger produts in iron obtained from a general ufe of calcareous iron ftones than any other. This fuperiority is derived from the congenial mixture of the ore, combined with a large proportion of lime, which facilitates the carbonation of the metal; and united with a juft portion of fand to conftitute fufibility, the fame column of blaft will, in the fame time, reduce a much greater quantity of it, affording the iron at the fame time fufficiently carbonated, than of other iron ftones differently combined. On the other hand, where the intention of the manuface. turer is to fabricate a quality of iron poffeffed of every requi- fite for converting mto good malleable iron, calcareous iron {tones, in quantity, ought to be avoided, and thofe of the argillaceous and filtceous claffes fubftituted. Thofe of — equalifed mixtures of earth, combined with pure argilla- eeous ores, afford the ftrongeft quality of crude iron; capable of being melted to advantage for the conftruétion of heavy pieces of machinery, or ufed for the purpofes of the forge. In the ufe of thefe clafles, however, creat ftrength and quan- tity will be frequently found at variance, when the quality of the metal is wifhed to be preferved carbonated: this alfo arifes from the nature of the mixture in the iron ftone; clay in quantity, united with various proportions of lime, forms an alloy, more difficult to fufe than where lime in quantity is united with various proportions of filex. Where nature has beftowed mixtures produdtive of every quality of crude iron, the proper arrangement of ores would become fimple and eafy ; juft combinations of mixture fupery fede the neceflity of changing the quality of the lime ftone added for a flux, or of having recourfe to various qualities of it, in order to affift or correét the deficiency of the native. mix- ture, Wherever the ores are of a {tructure thus deficient, it then becomes the province of the manufacturer to afcertain — the mixture of the individual ores which compofe his fupply, — and 7 in the Manufaéture of Crude Iron. bt ahd to reftore that equilibrium of parts by the proper appli- cation of fuperadded earths, which experiment and obfervae tion have proved to determine a certain quality of iron. Thofe works whofe fituation enables them to draw their fupply from fields of iron ftone, impreffed with all the varie ous characters of mixture, poffefs many advantages which thofe more infulated are frequently deprived of. With equal eafe ought the manufacturer to be able in thefe cafes to fabricate with certainty a quality of iron capable of forming to advantage the moft minute piece of cafting, or the heavieft piece of ordnance; at pleafure he might form a quality fit for the forge, or of value in the pig iron market. In fhort, where fuch variety of ores exift, iron of every quality, com- prifing fufibility and ftrength, may at pleafure be manufac- turéd, fuited to the many and various wants of a foundry and forge. Failing, however, of this univerfal affortment of iron ftone, nature has in many places kindly formed a competent fub- ftitute, in the great variety and quantity of lime {tone which are found within eafy reach of the blaft furnace, poffeffing component parts widely different from each other; from a ftate of the greateft purity, to the heavielt alloy of heteroge- neous mixtures; fometimes fo far debafed as not to be juftly appreciated when ranked under the clafs of lime-ftones. A want of analytical kuowledge ia the manufaéturer may often lead to the purchafe of fuch qualities as may be fuper- fluous, from the variety of his ores, or which are diametri- cally oppofite in quality to thofe which ought to have been applied. I fhall here annex the analyfis of the principal lime-ftones ufed at the Clyde Iron Works, which from their fuperior fituation, having eafy accefs to the eaftern or weftern oceans, can at pleafure draw their fupplies from a greater number of quarters than any other work in Britain. The filence of provincial hiftorians refpeéting the confti tient parts of various limes is a fecond inducement to fur- nifh fuch a table, which may enable the hufbandman to de- E2 cide 52 On the Ufe of Caldareous Stones cide with a jut preference upon that quality moft proper for the culture of his grounds. I found chalk to contain car- bonic acid and water - - 37°3 Silex and a minute portion of clay - 1'O45 Lime - - - (61655 100 parts. Irifh white lime-{ftone.—This beautiful calcareous ftone 1%, found in various places on the coaft of Ireland. It greatly refembles chalk, and differs only from it in its hardnefs, which it derives from a greater quantity of water ef cryftal- Jifation; it abounds with fine fpecimens of dog teeth and coxcomb cryfials; contains a confiderable quantity of flint in rounded and ovular forms, with very perfe&t {fpecimens of belemnites. I found this lime-ftone to contain water of cryftallifation and carbonic acid - 44°5 Silex and a minute portion of clay - 3°7 Lime - - . 518 ' 100 parts. ’ Trith blue lime-ftone from Learn.—This ftone is of a dark blue colour, fmooth fracture, and ftudded with {mall fhining fpicule ; it contains no mixture, or form foreign to itfelf. It contains water of cryftallifation and carbonic acid 37°14 Silex - - - 9°43 Lime - “ & 53°43 100 parts. Arran lime-ftone, from the Ifland of Arran.—This is a reddifh-coloured lime-ftone, abounding with fuch an im- menfe quantity of fhells, that the whole ftratum, which meafures 60 feet in thicknefs, appears to have been formed of fhells conneéted by means of a calcareous cement much lefs pure; thefe are all univalve, uncommonly large, fome of them 6 or 8 inches in diameter, and form the pureft lime. In calcination this ftone lofes its colour, and becomes as white as fnow ; perhaps a {mall portion of iron diffolyed in i the bits inthe Manufa&ure of Crude Tron. 53 the carbonic acid communicates to it the red.colour. I found it compounded as follows: water of cryftallifation and earbonie acid - - - 39-57 | Silex . A ast (hy ae 2°58 Clay . - . t: = 1°1g Lime- - . - 56°73 : Ico parts. » Campbletown lime-ftoneon the Argyle coaft.—This is a very dark blueifh-coloured lime-ftone, of a large granulated metallic fragture, hard and refractory; it prefents no {peci- mens of marine remains, but abounds with a common cal- eareous fpar, in which regular form is perceptible; when calcined it retains a delicate tinge of blue colour. I found the component parts of this ftone to be, water of cryftallifa- tion and carbonic acid - - 41°42 Clay - ~ - | 29409 Silex - - - 2°92 ‘Lime - . ” 53°253 100 parts. Thornton lime-ftone, parifh of Killbryde.—This is a light blueith clay-coloured lime-ftone, fufceptible of a fine polith, and abounding with a great variety of marine fhells of vari- ous fizes; the fchiftus contains an infinite number of the remains of fmall fifhes, fhells, &c. It yielded water and carbonic acid . - . 43°91 Silex - - - - 4°67 Clay - - 7 : 5 Lime he we > S = 50°92 IOO pal ta, _ Crefsbafket lime-ftone, fame parifh.—This ftone greatly refembles the former, but pofleffes a greater variety of quality, femytinnes inferior, but contains very few fhells or marine £3 remains, 54 ‘On the Ufe of Caleareous Stones remains. The following are its component parts: water of eryftallifation and carbonic acid - - 42°9 Clay, with a {mall tinge of iron - - 3°3 ok =e - - ay Lime * - . - 511 100 parts. Eai-Wood lime-ftone, from parifh of the fame name.— This is a fharp fplinty lime-fione, of an even fraéture, but abounding with fimall fpicule of filex; when expofed to wet for fome time its furface becomes oxydated like an iron ftone, It contains a great number of univalve and bivalve fhells, and marine decompofition of various kinds. It poffeffes not the property of falling into lime, unlefs watered when at a red heat; it then forms a coarfe pulverulent earth; of a greyith brown colour. It contains water and carbonic acid 27°42 Clay ~ - - - S73 Tron : - : = 5°83 Silex - - - = 30°66 2 Lime - 7° b : 26°36 100 parts. Lime-ftone from the neighbourhaod of Kirkintulloch.— _The appearance of this ftene is more favourable than the former, though of the fame inferior caft ; it contains no fub- fiances foreign to itfelf. Its conflituent parts are, water of eryfiallifation and carbonic acid - - 37°3 Clay A : E 12°5 Tron - - : ¢ 37135 Silex - : - - 8-36 Lime ~ - - - 38°705 ; 100 parts. Kylfyth lime-ftone.—This ftone is of a dark blue colour, fmooth fraGture, and founds like metal when ftruck upon, It abounds with the fineft fpecimens of pure calcareaus pars, frequently. in the Manufacture of Crude Iron. $5 frequently refolved into tranfparent cryftals: the chafms where thefe are found are fometimes enriched with beautiful prifmatic pyritical cryftals of a flat fealy form. ‘The com- ponent parts of this lime-{ftone are as follow: Water of eryftallifation and carbonic acid - - 39°52 Silex - - - - 5°73 Lime - - - : 54°75 100 parts. From what has been ftated, we are Jed to inquire into the eaufe which produces effects fo widely different in the fufi- bility and ftrength of crude iron, The exiftence of calcare- ous, argillaceous and filiceous earths in the blaft furnace, has been mentioned as effecting thefe changes; and it has been. alfo noticed that, under certain mixtures of thefe, determinate qualities of crude iron are produced. If a predominancy of calcareous earth is ufed as the ftandard for comparifon, with a local proportion of fuel, we find that in proportion as the lime is diminifhed in quantity, and clay added through the medium of the ore, the quantity of metal produced will be lefs, but its ftrength greatly in- creafed ; and if the argillaceous ores are pure, the carbona- tion of the metal will be little altered. Should filiceous mixtures be applied in place of argillaceous, we find that, in proportion as lime decreafes, and the quantity of fand in the furnace is augmented, the quality of the iron becomes lefs carbonated, lefs fufible, and its fmall portion of ftrength greatly impaired: fand through the medium of the ore may be added, fo as to render the iron as brittle as glafs, and as white in the fra@ture as filver. Again, let a predominancy of filiceous earths in the blaft furnace be the ftandard for comparifon; in proportion as thefe are diminifhed by the addition of argillaceous ores, the metal will pafsfrom the ftate of extreme brittlenefs and oxygenation, to a {tate comparatively ftronger and containing more carbon. Should calcareous jron ftones be added, their addition will E 4 immediately & 56 On the Manufaéture of Crude Tron, immediately correct the pernicious effects of the filex, and facilitate the carbonation of the metal; but will not confer any great degree of additional ftrength. Lime may be added to fuch excefs as to render the continuity of the particles of iron fo fmall as to be eafily divided into granulated mafles, forming a true plumbago. c From a confideration of thefe refults, we are led to attri- bute to calcareous carths the property of facilitating the car- bonation of the metal where an improper combination exits; which property is derived from the carbon of the acid with which they are neutralifed. To argillaceous ores we afcribe ftrength, without having the tendency of deftroying the carbon, merely becaufe thefe ores contain a very confiderable portion of lime; their unicn countera¢ts the natural fufibility impofed by lime, and at the fame time is produétive of ftrength. Siliceous iron ftones are viewed lefs favourably, being nearly deftitute of lime; the iron in the furnace yarics in principle from the development of its mixtures, and only depends upon the quantity of carbon furnifhed by the fuel to become faturated with a fufficiency to conflitute fufibility. The exclufive predominancy of lime and filex apart tends in the fmelting procefs to reduce crude iron to its two greatelt extremes of quality, carbonation and oxygenation ; both of which flates are equally deftitute of ftrength. Clay acts as the reftorer of thefe difproportions, and by a happy combination produces the medium of the two, extremes, which is firengtin and undiminifhed quality. ‘Were filiceous iron ftones univerfally combined with a larger portion of oxygen than the other clafles, another elue would be furnifhed to explain why. filiceous mixtures were — lefs congenial to the exiftence of carbon in the blaft furnace, than thofe of lime and clay; and why the metal obtained from the former is always more oxygenated with the fame portion of fuel than that obtained from the latter. Although J am convinced that this frequently is the cafe, yet, as Thave not i f Account of Bugs found in hollow Trees. 57 not been able to affume an extra fixation of oxygen in filice- ous iron ftones as an univerfal principle, I would not with to apply it, in any great degree, to the folution of the prefent theory, feeing the caufes already advanced are fufficient for . an explanation of the whole phenomenon. VIII. Account of Bugs found in hollow Trees, with Obferva- tions on that Phenomenon. By S, OEDMAN *. Ir is a well known prejudice among the country people in Sweden, that they believe the houfe bug takes up its refidence in the common yellow wall lichen, which grows under the juniper bufhes, &c.; but, as far as I have been able to learn, no entomologift ever yet found the real houfe bug in {tanding trees, and therefore the following new obfervation- feems to be worthy of attention. Laft Auguft fome work- men, who were cutting wood on an ifland in Namdéd Sound, fat down under a hollow alder tree in order to eat their dinner. One of them having accidentally made a noife near the trunk, aroufed a bat (ve/p. murinus), which was immediately feen to fly ont from a hole in the fide of it. Being defirous to know whether there were any more animals of the fame kind in the trunk, thefe wood-cutters gave it a violent ftroke, and a mafs was heard to drop, which one of them pulled out with his hand, and found to confift merely of bugs. It is impoffible they could be deceived in regard to vermin fo well known; and what rendered the circum- ftance ftill more certain, was, that they found under the wings of the bat, real bugs, which had taken up their abode there, together with the ufual infects that infeft thefe ani- mals. The.whole quantity of bugs amounted to about three quarts. M. Blix, who was.at great pains to examine this phenomenon more narrowly, found in the bottom of the * From New Tranfadtions of the Academy of Sciences at Stockholm, yal. x. hollow 58 Account of Bugs found in hollow Trees. hollow tree two concave places filled with firaw.and foft earth, in which the bats probably kept their young; for the old ones when they fleep generally fufpend themfelves by the hooks of their wings. Some time after, M. Blix having heard that a bat had been feen to fly into a hollow tree on the ifland where he refided, repaired to the place, and drove from the tree thirty-feven bats. It accidentally came into his head to examine with a ftick the roof of their dwelling ; and when he drew out the ftick he obferved the end of it covered with bugs. He made no farther examination till a few days before Chriftmas, when the tree was felled; but at this time neither bats nor bugs were to be feen. He, how- ever, difcovered that this tree had lodged guefts of various defcriptions ;. for the lower part had been imhabited by bats ; the roof of the cavity by bugs; the middle by nut-peckers, and the top of the tree by a fquirrel. It is not altogether improbable that the bugs had been carried thither from fome habitation by the bats, efpecially as they were found, in the firft cafe, on an ifland totally feparated from the continent, and on which there was not a finglehoufe. It is more diffi - cult to explain how fuch a multitude of bugs could find nourifhment on two or three dozen of bats; but inftances have been known of ftone buildings infefted with fuch ver- ‘min, remaining above a year uninhabited, and yet thefe in- feéts, fo far from being extirpated, have not even been leffened., We can fearcely then give any other explanation, than by fuppofing that bugs cat each other when they have no other nourifhment; and that the lofs thence occafioned is fupplied by their great multiplication. The caufe why no bugs were found when the laft mentioned tree was felled, may have been, that they were deftroyed by the birds. In confir- mation of the above, M. Carlfon adds the following cireum- fiance: “In the year 1777,” fays he, “I found an old rotten ftake, that had been ufed for a fupport in a hedge, which was fo covered with houfe bugs that it refembled an ant-hill; it lay at a great diftance from either houfes or gar- dens, Folia on Animal Ele&ricity. 59 dens. I inquired whether this flake had, at any time, formed part of a building, or been near one; but I was af- fured by a peafant that he had cut it down not far from the {pot, and that it had never been employed for any other pur- pofe. As this ftake was not hollow, and could afford no fhelter to bats, it does not appear how thefe bugs could bé conveyed to it from a houfe. ‘There is reafon to conjecture, rather, that thefe infects live and propagate even in timber. That they are able to endure the winter cold is beyond all doubt. I expofed a piece of furniture to the open air for three years, and every fummer bugs were obferved upon it in great abundance. IX. Od/ervations on Animal Eleétricity ; being the Subflance of two Letters from A. Vout a to Profeffor GREN *. I- a tin bafon be filled with foap-fuds, lime-water, or a ftrong ley, which is ftill better, and if you then lay hold of the bafon with both your hands, having firft moiftened them with pure water, and apply the tip of your tongue to the fluid in the bafon, you will immediately be fenfible of an acid tafte upon your tongue, which is in contaét with the alkaline liquor. This tafte is very perceptible, and, for the - moment, pretty ftrong; but itis changed afterwards into a different one, lefs acid but more faline and pungent, until it at laft becomes alkaline and {harp in proportion as the fluid aéts more upon the tongue, and as the aétivity of its peculiar tafte and its chemical power, more called forth, produce a greater effet in regard to the fenfation of acidity occafioned by the ftream of the eleétric fluid, which, by a continued circulation, paffes from the tin to the alkaline liquor, thence to the tongue, then through the perfon to the water, and thence to the tin again. I explain the phenomenon in this * From Neues Journal der Phy/fik, vol. iii. p. 4, and vol, iv. p. t. manner, 60 Volia-on Animal Eleéricity. manner, according to my principles ; and indeed it canmot be explained in any other, as every thing tends to confirm my affertion, and to prove it in various ways. The contact of different conductors, particularly the metallic, including pyrites and other minerals as well as charcoal, which I call dry condutors, or of the fir/ clafs, with moi conduétors, _ or conductors of the /econd cla/s, agitates or difturbs the elec- tric fluid, or gives it a certain impulfe, Do not afk in what manner: it is enough that it is a principle, and a general _ principle. This impulfe, whether produced by attraétion or any other force, is different or unlike, both in regard to the different metals and to the different moift conductors, fo that the direction, or at Jeaft the power, with which the electric ffnid-is impelled or excited, is different when the conductor A is applied to the condu€tor B, and to another C. Ina perfect circle of conductors, where either one of the fecond clafs is placed between two different from each other of the firft clafs, or, contrariwife, one of the firft clafs is placed between two of the fecond clafs different from each other, an eleétric ftream is eccafioned by the predominating force ¢ither to the right or ta the left—a circulation of this fluid, which ceafes only when the circle is broken, and, which is renewed when the circle js.again rendered complete. This method of conneéting the different conduétors will be more readily comprehended by turning to the figures, (plate I,) where the capital letters denote ihe different conductors or exciters (moteurs) of the firft clafs, and the fimall letters thofe of the fecond clafs. Fig. 1 and 2 exprefs the two cafes aboye mentioned. I confider it as almoft fuperfluous to obferve, that when the circle confifts merely of two kinds of conductors, hawever different or however numerous the pieces may be of which each confifts (as fig. 3, 4, 5 and 6), two equal powers are eppofed to each other ; that is, the electric fluid 1s impelled with equal force in two different directions, and confequently : . ne Folta on Animal Eleetricity. 61 no fiream can be formed from right to left, or contrariwile, capable of exciting convulfive movements. There are other cafes, however, and other modes of com- bination, where the powers are equally in equilibrium, and where no current of the electric fluid can take place; or, at leaft, none of fuch a force as to make an impreffion on the tendereft nerves, or to excite any convulfive movement in the . beft prepared frog that may be placed in the circle, notwith- ftanding the intervention of two or more different kinds of metals. This is the cafe when each of thefe metals is placed between two moilt conductors, or of the fecond clafs, and which are very nearly of the fame kind, as fig. 7; or when, in a circle of three pieces, two of them of the fame metal, and one of a different metal, are fo connected, that the latter is immediately between the other two, as fig. 8. When one of the ends of the middle piece of metal A is immediately applied to one of the two pieces Z, but, inftead of immediately touching with the other end, the other piece ze touches an intermediate cenduétor of the fecond clafs, either great or fmail, either a drop of water, a piece of raw or boil- ed ficth, or of fponge not moift, pafte of meal, jelly, foap, cheefe, or the white of an egg boiled to hardnefs, in this new combination, reprefented by fig. 9, (where a condu¢tot of the fecond clafs m is between two of the firft clafs, A and Z) the powers are’no longer oppofed to each other; and this is fufficient to determine an electric ftreaam. When g, there- fore, in fig. 9, is a prepared frog, it will always be violently agitated as often as this circle is made complete. It may be readily perceived that the two laft experiments, reprefented by fig. 8 and g, coincide with thofe announced by M. Humboldt, where a drop of water, a fmall bit of freth meat, or avery thin ftratum of any fluid, performs the whole wonder. When another drop of water, or any other aqueous gonduétor, is applied betwen ‘the other end of A and the ether correfponding piece Z (as fhewn fig. 10), each piece ef metal is infulated, as I (hall exprefs it, between two aqueous 62 Volta on Animal Ele&ricity. aqueaus conductors: but then the powers from right to left, and from left to right, are again completely oppofed to each other; confequently the electric ftream is impeded, and the frog remains without any movement. It is, therefore, abfo- lutely neceffary that two different metals or conductors of the firft clafs fhould be in immediate contact with each other, oa the one fide, while with their oppofite ends-they touch eonduétors of the fecond clafs. We might confider this mutual contact of two different metals as the immediate caufe which puts the electric fluid im motion, inftead of aicribing that power to the contact of the two métals with the moift condu€tors. Thus, for ex- ample, in fig. 1, inftead of admitting two different actions, at leaft, in regard to the magnitude of the power, one where A comes in contaét with a, and another where Z comes in contaét with @ alfo, by which an eleétric current arifes in the direétion from Z to A, we might fuppofe only one ac- tion at the point where A comes in contaét with Z, which impells the fluid in that direction. In both fuppofitions the refult, as may be eafily feen, is the fame. But though I have reafons for adopting the firft as true rather than the fe- cond, yet the latter reprefents the propofition with more fim- plicity, and it may be convenient to adhere to it in the ex- planation, as it alfords a readier view of it. We may then fay, that in the cafes of fig. 3, 4, 5,6, 7 and-1o, no effect will be produced, becaufe here there is no mutual contaé of different metals: that the effeét alfo, according to fig. 8, will be null, becaufe A, on two oppofite fides, is in contaé with Z and Z, and the actions therefore are in eguilibrium; and laftly, that an electric current will be occafioned in fig. 9, by the action which arifes from the conta of A and Z, and which is counteracted by no other contact of the like kind. Having feen the refult of employing three pieces of metal, or conductors of the firft clafs, viz. two of one kind and one of a different, when combined fometimes in one way and fometimes in another with conduétors of the fecond clafs, 6 we be Volta on Animal Eleéricity. 63 we thall now try what will be the refult, according to my principles, with four pieces of metal, two of which are of one kind; for example, zinc, when connected with moift conductors of different kinds. ; I fhall firft obferve, that when they are conneéted in a cir- cle, as at fig. 11, the powers which endeavour to put the electric fluid in a ftreaming movement will be oppofed to each other, and in perfect equilibrium, and that confequent- ly no movement can take place in the frog, here fuppofed to be the moift conductor a2 or a part of it, however irritable and well prepared it may be; and if the experiment be made with accuracy and the neceffary preeaution, fo that the me- tals, in particular, be very clean and dry at the points of con- tact, it will perfectly confirm what I have above faid: the frog will experience no agitation, no convulfive movement. Thefe movements, on the other hand, took place, as might be forefeen from my principles, as often as I omitted one of the middle pieces, or changed the order. The conduétors of the fecond clafs, which in all the figures are denoted by {mall letters, may be cups with water, in which the ends of the pieces of metal denoted by the large letters are immerfed ; or fponges or other bodies which have imbibed aqueous moifture. They may be either large or fmall; and may confift of one or more pieces, provided they be in pro- per conta&t: they may alfo be perfons, if their {kin be moift- ened at the places of contact, &c. By the laft method the experiments will be very beautiful and inceffant, when the circle confifts of three or more perfons (I have formed it fre- quently of ten and cven ‘more), of two or more frogs pro- perly prepared, and of four pieces of metal, two of filver and two of iron, tin, and particularly zinc. The change of effe&t, when you change the connection, is ftriking. Let the pofition be as reprefented in fig. 12, where g is the prepared frog, which the two’perfons #, p, hold in their hands, one on the one fide by the feet, and the other on the oppofite by the rump. Z, Z are two plates of zinc, whigh are 64 Volta on Animal Ele&ricity. are held alfo by thefe perfons, and A, Ay two picces of filver, which are held by a third perfon, denoted alfo by p. It mutt not be forgotten that the hands {ould be very moilt,»as the dry fkin is not a conductor fyfficiently flrong. As in this chain the actions of the electric exciters are oppofed to each other and in exact equilibrium, as may be readily perceived, no convulfion or agitation in the frog will take place. Now, let one of the metallic pieces A, Z, which ftand be- tween the two perfons p, p, or between anyother moift con- ductors, be left in combination as it is; and jet the pofition of the two other metallic pieces A, Z, be reverfed, by convert~ ing fig. 12 into fig. 13 (fo that the actions, inftead of being contrary, will act together to impel the electric fluid to one fide or to produce the fame current); or introduce between A and Z another perfon, or any other conduétor of the fe- cond clafs, fo that the chain be formed as in fig. 14; or take away one of the pieces A, Z, in fig. 12, and make the chain like thofe of fig. 15 and 17; or, in the laft place, remove the whole two pieces A, Z, either in the one or the other fide, as reprefented fig. 17 (by which means it will correfpond with fig. 1, as the whole chain p, g, p, p, may be confidered as a fingle moift conductor of the fecond clafs); in all thefe com- binations, which are reprefented by fig. 13, T4, 15, 16, and 37, the actions arifing from the metallic contacts aré no longer contrary to each other, or in equilibrium, as they were in fig. 12 ; confequently an eleétric fiream is produced, and the frog g, which I fuppofe to be properly prepared, and which forms a part of the chain, will be violently agitated as often as the circle, when broken at any one place, particu- larly between metal and metal, is again reftored, In'regard to the experiment where a moilt conduétor, or one of the fecond clafs, is to be introduced betwcen the two pieces A, Z (fig. 14), that is, between two different metals, a drop of water, or a fmall bit of moiftened fponge, or a thin firatum of any fluid, foap, or any other vifcous matter, will be quite fufficient, as I have already obferyed refpeCing fig. g. This Volta on Animal Eleéiricily. 65 ‘This furprifing experiment I generally make in fuch a man- fer, that, inftead of the piece of metal, I employ 2 cup or fpoon filled with water, arid then caufe the perfon who holds the perfectly dry and pure ftick of tin to touch with that ftick fometimes the perfectly dry fides of the fpoon or cup, and fometimes the watef coritained in them. It is wonder- ful to fee, that as by the lattet method the violent agitation of the frog never ceafes, the firft method, which correfponds with fig. 12, does not produce the leaft irritation; unlefs by accident there be a fmall drop of water, or a thin ftratum of moifture; at the place of contaét, by which the cafe repre- fented fig. 14 would be reftored. This may ferve to fhew with what care and attention the experiment mutt be made, in order to guard againft error or deception, which might fo eafily arife, and every where exhibit anomalies. When I introduce water or arty other moift body, great or fmall, not merely between one pair of metallic pieces A; Z, as fig. 14, but between two pairs, as reprefented fig. 18, ach piece of metal is betweeti like moift conductors, and by thefe means all the actions are again rendered contrary or brought into equilibrium ; or, according to the other mode of viewing the matter, there is no longer any action, for want of the mutual contac of two different metals, which, as we have feeri, is certainly neceflary to excite an electric cur- rent; and if is always found that the frog experiences no agitation. I fhall not enlarge farther on thefe combinations, which may be varied ad infinitum: with a greater number of me- tallic pieces, and by which one may be enabled to foretel the phenomena which, according t6 my principles, will always be found to take place. It will be fufficient, for the prefent, to draw this conclufion, that in a circle confifting merely of two conductors, however different they may be, their mutual contact ean produce no eleétric ftream fufficient to excite fenfibility or mufcular movement; and that, on the contrary, this effect infallibly follows as often as the chain is Vou. lV, F formed * 66 Volta on Animal Eleétricity. formed of, three conduétors, one of one clafs, and two dif ferent from each other of another clafs, which come into mutual contact with each other, and that this effect will be ftronger the greater the difference is between the latter; that in’ other cafes, where there are more than three different conductors, the effect either is not produced or will be pro- duced: in different degrees, according as the forces, called forth by the difierent combinations, which will be expanded at each heterogeneous contact, and which are often in op- pofition and endeavour to impel the eleétric fluid in oppofite direGtions, are perfectly in equilibrium with each other, (which muft be a very rare cafe) or when the fum of thofe which exert themfelves in one direStion is more or lefs ex- ceeded by the fum of thofe which aét in another direction, I fhall here however Jeave the two complex combinations, and return to the fimple cafes, thofe with three different. condu@tors, reprefented by fig. 1, which are more demon- firative; or, in other words, thofe with two different metals or conduétors of the firft clafs which are in conta& with each other, and are applied onthe other fide to moift con- duétors or conductors of the fecond clafs. This method has been commonly employed fince Galvani’s difcovery, and is in exa&t proportion with the diverfity of metals on which I confider the whole phenomena to depend. The other method of combination, which is. expreffed by i fie. 2, or that of a metal placed between two different moift conductors, for example, between water on the one fide, and an aqueous, faponaceous, or faline fluid on the other, I difcovered in the autumn of 1794; and though fince that period I have repeated the much varied experiments of dif- ferent perfons, both foreigners and others, among which was that of M. Humboldt, and though I wrote to feveral correfpondents refpecting it, that light has not yet been thrown on this new phenomenon which it feems to deferve, The fingular circumftance before mentioned, in regard to the acid tafie when the tongue is-brought into contaét with x ae an, Volta on Animal Eletiricity. OF fin alkaline liquid, belongs, as you may perceive, to this fe- cond method of exciting the electric fluid and putting it in circulation (if the tin veffel be touched on the outfide by the hand moiftened with water, and on the infide by the alka- line liquor), and fhews that this current is no lefs ftrong and active than that excited by the firft method, viz. by employ- ing two fufficiently well chofen metals, fuch as lead and copper, iron and filver, zinc and tin. I muft here obferve, that though with tin alone, placed between water and an alkaline itecine you obtain nearly the effect which is produced by two of the moft different metals, as filver and zinc, com- bined with any conduétor whatever of the fecond clafs; you can obtain the fame, and even in a higher degree, with iron alone or filver alone, when the iron is introduced between water on the one fide and nitrous acid on the other, or when the filver is applied between water and 4 folution of fulphure of pot-afh. If you take a frog, the head of which has been cut off, and which has been deprived of all life by thrufting a needle into the fpinal marrow, and immerfe it, without fkinhing it, taking out the bowels, or any other preparation, into two glafles of water, the rump into one, and the leg into the other as ufual, it will be ftrongly agitated arid violently con- ‘vulfed when you conuneé the water in both glaffes by a bow formed of two very different metals, fuch as filver and tin or lead, or, what is better, filver and zinc; but this will by no micans be the cafe when the two mietals are Jefs different in régard to ‘their ‘powers, fuch as gold and filver, filver and copper, copper and iron, tin and lead. But what is more, the effec will be fully produced on this fo little prepared frog When you immerfe in one of the two elaffes the end of a bow merely of tin or zinc, and into the other glafs the other end of this bow which has been rubbed over with a little alkali. You may perform the experiment ftill better with an iron bow, one end of which has been covered with a Io drop 68 Hints sfor the Formation of drop or thin coating of nitrous acid; and beyond all expec- tation, when you take a filver bow having a little fulphure of pot-afh adhering to the end of it. Fig. 19 reprefents the form of this experiment, where ¢ is the frog, 2, @ the two glaffes with water, A the bow formed of one fingle metal, and m the drop or a thin ftratum of a mucous, faline, &c. fluid with which the bow has been rub- " bed over, and which on this fide is between the metal and the water. [To be continued. ] X. Agenda, or a Colleétion of Obfervations and Refearches the Refults of which may ferve as the Foundation for « Theory of the Earth, By M. pe Saussure*. [Continued from page 299 of Vol, III.} CHAP. XV. Obfervations to be made on primitive Mountains. x W HETHER there be any exception to the gene~ rally received opinion, that, in primitive mountains, no veftiges are difcovered of organifed bodies. 2. Whether it be true that in thefe mountains no indica-, tions are found of bitumen or marine falt. 3. To endeavour to determine, the refpeCtive ages of the different kinds of primitive mountains; both compound, fuch as granite, porphyry, gneifs; and fimple, as flate, fer- pentine, and primitive calcareous.. 4. Whether, in particular, it be certain that granite is the moft ancient ftone of alt thofe which form the outer cruft of | our globe, fo that it is never found placed above (fuperpofé ) any other kind of ftone. ** From Journal des Mines, Ne, XX. 5. Whether _ a Theory of the Earth. 69 5. Whether the large mountains compofed of granite in one mafs, even the beft charafterifed, do not give certain in- dications of ftratification or divifions by ftrata, though lefs regular than thofe of fchiftous mountains. 6. Whether in the bafes of granite mountains the mani- feftation of ftrata be not hurt by the number of fiffures, or {fpontaneous and irregular divifions. 7. Whether, even in the feparate blocks of granite, an at- tentive eye does not difcover fome veins of mica, which af- fe&t the fame direction, and fuch veins as induce the work- men, who wifh to make mill-ftones or other works more ex- tenfive in one direétion than another, to prefer attacking the {tone in a determined direction. 8. Whether the indications of the ftratification are not obferved in the interior part of granite mountains, as well as near their furface. 8. A. Whether among the granites in a mafs, and thofe decidedly veined, there are not found fuch intermediary fhades that it is difficult to mark the line of feparation. g. To determine the diftinguifhing charaéters of granites of modern formation. 11. To afcertain the truth of the affertion of the Pliny of ‘France, that in proportion as people dig into a mountain, the fummit and fides of which confift of granite, the granites, inftead of being found more folid afid more beantiful the farther they advance, change, on the contrary, below a cer- tain depth, lofe themfelves, and at laft vanifh by gradually affuming the coarfe (brute) nature of the live quartzy rock*. 12. Whether it be true that each primitive mountain is generally compofed of one fingle ftone, and of the fame nature. 13. To examine whether there be found on the primitive mountains, at great heights, the feattered wrecks of fecondary mountains. For my part, I never found any. 14. Whether primitive calcareous ftone be found always * Minecraux, p. 105. F3 with 0. Hints for the Formation of a Theory of the Earth. witli a granulated fracture, or the form of a faline marble, “and neverunder a compact form. - 15. Ought the porphyric fchift of Werner, or the porphyre Schifleux % pdte of primitive petro-filex, to be confidered as primitive or fecondary? The fame queftion in feels to the mandelftein or amygdaloid. 16. Is it fully afcertained, as I thought I obferved in the Alps, and M. de Fichtel in the Carpathian mountains, that there exifts pudding-ftone or free-ftone, if not primitive, at leafl of a formation anterior to that of all the other fecondary {tones ? 17. Were the granites in a mafs firft depofited, becaufe they were lefs foluble? and did they cryftallife after the quantity or diffolving foree of the waters began to diminifh ? and was it for a contrary reafon that the gneifs, mica and magnefian ftones cryftallifed later ? CH A‘P,s XVI. Obfervations to be made on Tranfitions. 1. To obferve the intermediary genera and fpecies of foffils, between one genus or one fpecies of foffil, and the genera and f{pecies which have the greateft refemblance to them. re To obferve; above all, the tranfitions through which nature has pafled, when, having produced ‘one genus or one order of mountains, fhe began to produce a different genus or order ; ; for there is no change of order which has not been the effet of a reuslatfters. and it is in the tranfitions that traces of thefe revolutions are tq be found. cn Thas we often {ce ftrata of free- fione or pudding-ftone interpofed between the primitive and fe -condary mountains ; breches are feen to,form the moft-elevated ftratum, and con- fequently the newelt., of fome calcareous mountains. We muft ftudy then the nature, dimenfions and pofition of thefe yemarkable firata. 4. Having : On ihe Manufaéture of Verdigrife. ai 4. Having found thefe tranfitions, or any others, in fome mountains, if they are not then found in other mountains, you muft examine whether their abfence does not arife from their having been deftroyed; veftiges of them are to be fought for; and if it appears that they never exifted, you muft endeavour to difcover, in the nature and pofition of the mountains, what may have been the caufe of their abfence*. [ To be continued. j XI. Od/ervations on the Manufatiure of the Acetite of Copper or Verdigrife, Verdet, Sc. By J, A. CHAPTAL.T Tur ; acetite of copper is one of the preparations of that metal moft frequently ufed in the arts. It is not only one of » the principal refources of painting, but upon many occafions is employed with great advantage in dyeing. Almoft all the oxydes of copper obtained by the aétion of faline fubfances have a blue colour, more or lefs inclining to green, and almoft all the neutral falts corrode the metal, and produce that oxyde which is called verdigrife. It is fufficient to bring them into contact with the copper, or to immerfe the metallic plates in a faline folution, and afterwards to expofe them to the air to dry. . Thofe acids which oxydate the copper by their decompo- fition, produce an effect like that of neutral falts, The oxyde is of a foft blucifh-ereen colour; their aétion is fo {peedy, that if the copper be expofed to the vapour of them for fome minutes its furface will. be immediately oxydated. The oxygenated muriatic acid produces that effeét as well as the. vapour of the nitric acid, and even thofe of the fulphuric acid. A phenomenon which cannot efcape the eye of an * The beft method of obferving mountains, in order to acquire a tho- rough knowledge of them, is, not to confine onefelf merely to follow the valleys, but to interfeét alfo, as much as polfible, the principal chains and the branches detached from them inthe direction of their breadth. C, t From Annales de Chimie, No. LAXY. F4 obferver, * 92 ‘The Progfs followed at Montpellier in obferver, is, that the oxydes of copper obtained by fire are very different from thofe produced by the decompofition of acids on that metal. The colour of them is grey, inftead of being green; and when the calcjnation is continued a long time at a violent heat, they may be concentrated to a red oxyde of qa blood colour. This phenomenon was obferved by Kunckel in his chemical Jaboratory. Saline fubftances are not the only ones capable of oxydat- ing copper green. All ojls and fat matters produce the fame effect. Even water, when left for a confiderable time in copper vefiels, caufes an oxydatjon. But what will appear very extraordinary is, that the greater part of thefe fubftances have no fenfible effect upon copper, except when cold, Thofe falts even which corrode that metal when left at reft in veffels, do not attack it in fo fenfible a manner when in a ftate of ebullition. Of all the preparations of copper by oxydation, there is none more valuable than that made by vinegar. All the verdigrife ufed in commerce is prepared by that acid, and it is at Montpellier jn particular and in the neighbourhgod, that the manufactories of it are eftablifhed, In the Memoirs of the Academy of Parjs for 1750 and 1753, may be feen a very exact defcription of the procefs then followed at Montpellier for making verdigrife; but as that procefs has been much improved, and as at prefent the hufks of grapes are employed inftead of the ftalks, a method far more economical, fince wine is no Jonger ufed, the following account of the man- ner of manufacturing verdigrife, as naw praétifed, may be of utility to the public, The firft materials ufed for this purpofe are copper and the hufks or fkins of grapes left after the laft prefling. The copper employed was formerly all imported from Sweden ; but at prefent it is brought from different foundries efta- blithed at Saint Bel, Lyons, Avignon, Bedarieux, Montpellier, &e, It is in round plates half a Jine in thicknefs, and frem twenty to twenty-five inches in diameter, Each plate at : | Montpellier the Manufafluring of Verdigrife. "3 Montpellier is divided into twenty-five Jamine, forming almoft all oblong fquares of from four to fix inches jn length, three in breadth, and weighing about four ounces. They are beat feparately with the hammer on an anvil to fmooth their furfaces, and to give the copper the neceffary confiftence, Without this precaution it would exfvliate, and it would be more difficult to fcrape the furface in order to detach the oxydated cruft. Befides this, {eales of pure metal would be taken off, which would haften the confumption of the copper. The hufks of grapes, known at Montpellier under the name of racque, were formerly thrown on the dung-hill after the poultry had picked out the fmall ftones contained in them. At prefent they are preferved for making verdi- grife, and fold at the rate of from fifteen to twenty livres per muid. 'The preparation of them is as follows: After the vintage is finifhed, the hutks are fubjected to the prefs, in order to extract all the wine with which they may be im- pregnated, and they are then put into vats, where they are prefled down with the fect to fill up all the vacuities and sender the mafs as compact as poffible. The coverings of thefe vats are carefully faftened down, and they are preferved for ufe in a dry cool place. Thefe hufks are not always of the fame quality: when the _ grapes contain little of the faccharine matter, when the fea~ fon has been rainy, the fermentation incomplete, or when the wine is not generous, the hufks are attended with feveral faults. 1, They are difficult to be preferved, and there is great danger of their foon being fpoilt. 2. They produce very little effe&t, cannot be cafily heated, fend forth very lit- tle of the acetous odour, and make the plates of copper fweat without fhewjng efflorefcence on their furface. Indepen- dently of the nature of the grapes and the ftate of the wine, the quality of the hufks varies alfo according as they have been expreffed with more or lefs care. Hufks which have not been much preffed, produce a far greater effect than thofe which have been dried, To explain their different effeéts, it 74 . The Procefs followed at Montpellier in it willbe fufficient to obferve that their a¢tion is propor+ tioned to the quantity of wine they retain, as it is that liquor alone which can pafs to the ftate of vinegar. When the hufks therefore are deftined for a verdigrife manufactory, care mutt be taken to exprefs them only weakly, in order to pre- ferve more of their acidifiable principle. » When a fufficient quantity of copper and of hufks has been provided, nothing renrains but to proceed to the opera- tions, which are generally performed in cellars. They may | be performed alfo on a ground floor if it be fomewhat damp, if the temperature be fubject to little variation, and if there be not too much light. | The firft operation is to make the hufks ferment, which is called avina. For that purpofe one of the vats is opened, and the hufks are put into two others of equal fize, taking care to expofe them as little as poffible to the air, and not to comprefs them. Qne vat full of hufks ought to fill two, and to occupy a double fpace after this operation. In fome manufaétcries the hufks contained in a vat are difiributed into twenty or twenty-five earthen veffels or jars called oxdes, and which are vénerally fixteen inches in height, fourteen in diameter at the belly, and_about twelve at the mouth. When the hufks have been put into thefe’ _veffels, they are covered by putting the lid merely on the opening without prefling it down. The covers are of ftraw, and made for that purpofe. In this flate the hufks foon Keat ; and this change may be known by thrufting the hand into them, and by the four {mell which they begin to exhale, The fermentation firft takes place at the bottom of the veffel, and gradually afcending extends itfelf to the whole mafs. It proceeds to 30 or 35 degrees of Reaumur. At the end of three or four days the heat decreafes, and at length ceafes entirely; and as the manufacturers apprehend the lofs of a portion of the vinegar by the natural effeét of a’ heat too much prolonged, they take care after three days fermentation to remove the hufks from the fermenting veflels,” in order that they may fooner coal. Thofe who employ vats: yee . remove the Manufacturing of Verdigrife. "6 remove them into jars, and thofe who ufe jars put them into others. Befides the lofs of the acetous fpirit, too great heat inclines the mafs at the bottom of the veflel to become mouldy, which renders it unfit fer making verdigrife. Some manufacturers, to increafe the effect of the hutks, form them into heaps, which they befprinkle with generous wine before they bring them to ferment. The fermentation does not always take place at the fame time, nor with the fame energy. Sometimes it commences in twenty-four hours, and fometimes it has not begun at the end of three weeks. The heat fometimes will rife to fuch a height that the hand cannot be kept in the mafs, and that the acetous odour is fo firong that one can hardly approach the veflels ; while at others the heat is hardly fenfible, and foon vanithes. There are even inftances of the hufks becom- ing putrid and mouldy without turning. acid. The fermen- tation is affifted and promoted by raifing the heat of the place by means of chafing-difhes, by covering the veflels with cloths, by fhutting the doors, and by-airing the mafs with more care. The differences in the fermentation depend, 1. On the temperature of the air: in fummer the fermentation is fpeedier, 2. On the nature of the hufks: thofe which arife from yery faccharine grapes heat more eafily. 3. On the yolume of the mafs: a larger mafs ferments fooner, and with more ftrength, than a {mall one. 4. On the contact of the air: the beft aired hufks ferment beft, At the fame time that the hufks are made to ferment, a preliminary preparation called de/afouga is given to the plates of copper which are ufed for the firft timc. This operation is not employed for thofe which have been al- ready ufed, and centifts in diffelving yerdigrife in water in an earthen veffe], and rubbing over each plate with a picce ef coarfe linen dipped in this folution, The plates, are then immediately placed clofe to each other, and Jeft in that piannes to dry. Sometimes the plates are only Jad on the top 76 The Proce/s followed at Montpellier in top of the fermented hufks, or placed under thofe which have been already ufed for caufing the copper to oxydate. It has been obferved, that when the operation called de/afouga has not been employed, the plates grow black at the firft opera- tion, inftead of becoming green. When the plates are thus prepared, and the hufks have been brought to ferment, the workmen try whether the lat- ter are proper for the procefs, by placing under them a plate ef copper, and leaving it buried there for twenty-four hours. | If the plate of copper, after this period, is found covered with a fmooth green cruft, in fuch a manner that none of the metal appears, they are then thought fit for being dif- pofed in layers with the copper. On the other hand, if drops of water are obferved on the furface of the plates, the plates are faid to fweat, and it is concluded that the heat of the hufks has not fufficiently fubfided. They confequently defer making another trial till the next day. When they are af- fured that the hufks are in a proper ftate, they form them into layers in the following manner : The plates are all put into a box, which, inftead of having 2 bottom, is divided in the middle by a wooden grate. The plates difpofed on this grate are fo ftrongly heated by a chafing-difh placed under them, that the woman employed in this labour is fometimes obliged to take them up with a cloth, in order that fhe may not burn her hands, As foon as they have acquired that heat, they are put into the jars in layers with the hufks. Each jar is then clofed with a cover- | ing of ftraw, and left to oxydate. This period is called coiia, to hatch. Thirty or forty pounds of copper, more or Jefs ac- cording to the thicknefs of the plates, are put into each jar. At the end of ten, twelve, fifteen, or twenty days, the jar is opened ; and if the hufks are white, it is time to take out the plates. The cryftals are then feen detached, and of a Glky appearance on their furface. The hufks are thrown back, and the plates are put in what is called re/ai, For that pur pofe wi Ps the Manufaéturing of Verdigri/e. hd pofe they are immediately depofited in a corner of the cellar on fticks ranged on the floor. They are placed in an upright pofition, one leaning againft the other; and at the end of two or three days they are moiftened, by taking them up in handfulls and immerfing them in water in earthen pans. They are depofited quite wet in their former pofition, and left there for feven or eight days; after which they are once “or twice immerfed again, This immerfion and drying are renewed fix or eight times, every feven or eight days. As the plates formerly were put into wine, thefe immerfions were called one wine, two wines, three wimes, according te the number of times. By this procefs the plates fwell up, the green is nourifhed, and a coat of verdigrife is formed on all their furfaces, which may be eafily detached by fcraping them with a knife. Each jar furnithes five or fix pounds of verdigrife at each operation. It is then called freth verdigrife, morft verdigrife, &e. This verdigrife is fold in that ftate by the manufactu- rers to people who dry it for foreign exportation. In this firft ftate itis only a pafte, which is carefully pounded in large wooden troughs, and then put into bags of white leather, a foot in height and ten inches in diameter. Thefe bags are expofed to the air or the fun, and are left in that tate till the verdigrife has acquired the proper degree of dry- nefs. By this operation it decreafes about fifty per cent., more or lefs according to its primitive fiate. It is faid to ftand proof by the knife, when the point of that inflrument pufhed againft a cake of verdigrife through the fkin cannot. penc- trate it. The plates of copper which have been already ufed are again employed for the fame operation, till they are almoft eompletely confumed. Inftead of heating them artificially, as above mentioned, they are fometimes expofed only to the fun. The fame plates will ferve fometimes for ten years, but they are often worn out in two or three. This, however, depends 58 On the Manufacture of Verdignfe. | depends on the quality of the copper. That whichis éx- tremely fmooth, well beat, and very sieges is — moft efteemed. Formerly moift verdigrife ‘could not be fold till its ee ity had been previonfly afcertained; and for that purpofe it was carried to a public warehoufe, where it was fold after that point had been determined. . By comparing this procefs with that defblbedl isi Montet, it will be found that the clianges introduced are much in’fa= vour of the new. © Formerly the workmen took the ftalks of the grapes dried in the fun, and began by immerfing them for eight days in vinaffe (the refiduum of the diftillation of wine for making brandy). They then fuffered the moifture to'drain off through a bafket, after which they put about four pounds into a jar, and poured over them three or four-pints of wine, The fialks were made to imbibe a large portion of the wine, by ftirring them ftrongly with the hand; the jar was then covered, and the ftalks were fuffered to ferment. ‘The fer- mentation commenced fooner or later, according to the na- ture of the wine and the temperature of the air, But after it had once begun, the wine became turhid, and exhaled a ftrong odour of vinegar. At length the heat decreafed, and the ftalks were then taken out and the wine was drawn off When the ftalks were a little drained, they were difpofed in layers with the plates of copper, and the operation was con+ tinued in the fame manner as with the hufks. When the . plates were taken from the jars to be put in relaz; inftead of immerfing them in pure water, as is done at prefent, they were moiftened three or four times with four wine, which was called giving them three or four wines. 7 It may be eafily feen that there is a great faving: i in the | procefs followed at prefent, fince the manufaéturers no longer ufe wine, which enhanced the price of the verdigrife. Some have condemned, in the new proces, the practice of ufing the’copper too foon; but this cbje¢tion fell to the-ground, when 6 . Vie On Candles with IVooden Wicks. 49 when it was obferved that the verdigrife obtained was in pro- portion to the copper corroded ; aud what proves that this method is more advantageous, is, that all the manufacturers have abandoned the old method and adopted the new *, XII. On the Method of preparing Tallow Candles with Wooden Wicks. By Profeffar Mevicus of Heidelbergt. by For feveral years paft tallow candles with wooden wicks have been prepared, in large quantities, by the candle- makers at Munich, and much uled in that neighbourhood. I have burnt them during the whole winter, and never with to ufe any other kind, as they are attended with feyeral ad- vantages which common tallow candles do not poflefs. They afford about the fame quantity of light as a wax candle; burn alfo with great fleadinels and uniformity, and never crackle or run, The candle-makers here keep the method of preparing thefe candles as fecret as they can; but I thall “communicate to the public what I have been able to learn refpecting the procefs. . ‘¢ The only difference between thefe candles and the common tallow candles is, that the ground work of the wick confilis of a very thin flip of wood, bound round to a confiderable thicknels with very fine unfpun cotton; but in fuch a manner that the fize of the wick does not much ex- ceed that of the wick of a common candle. The cotton is wound round the wick by the hand; but in’ general it is done by means of a reel, which I haye not yet been able to » fee. The thin flips of wood are furnifhed to the candle- makers by the country people, and, if we may judge from * There are no large manufaétories of verdigrife at Montpellier; but each family makes a certain quantity, and the operations are in general performed by women. + From Riems Neue Sammlung Ockonomifcher Schriften, part xii. - their a. . Ms a ae 80 Method of making Tallow Candles with Wooden Wicks. their appearance, are cut into the proper form by means of @ knife, without the application of any machine. They are for the moft part foniewhiat fquare, and not completely rounded. The candle-makers often prepare thefe flips of wood alfo themfelves, when they have none ready by them, and for that purpofe ufe pine, willow, and other kinds of wood, though they commonly employ fir. For making thefe candles it is neceffary to have the pureft tallow: a pound will be fufficient to make fix or feven, which coft 25 kreutzers. The price of common moulded candles with cotton wicks is 42 kreutzers; but as the former burn much longer, they are on the whole cheaper.” Another method of making the wicks is as follows: Take fhoots of the pirte-tree a year old, fcrape off the bark, and when. they are become perfectly dry ferape them again all round till they are reduced to the fize of a fall ftraw. When the above wood cannot be procured, well dried cgmmon fir twigs of a year old, and of the fame ftrength, may be pre~ pared in the like manner. Thefe rods are then to be rubbed éver with wax or tallow, till they are covered with a thin coating of either of thefe fubftances; after which they muft be rolled on a fmooth table m very fire carded cotton, drawn out to about the length of the rod or cand}e-mould. Care however mutt be taken that by this rolling no inequali- ties may arife on the red, and that the cotton may be every where of equal thicknefs, though at the upper part a little more of it may be applied. After this preparation the wick will have acquired the fize of the barrel of a {mall quill; and the more accurately the fize of the wick is proportioned to that of the candle mould, the candles will burn fo much - the better, clearer and longer, as will foon be found by alitile experience : thefe wicks are then to be placed very exaétly in the middle of the mould, and retained in that pofition, and good tallow, freth if poffible, previoufly melted with a little water, mutt be poured round them; but even old and rancid tallow ‘ will not run, if the wicks be properly made.. Se Thefe — if On preparing Lakes with the Tung/ftic Acid: gr Thefe candles, befides burning longer than the common ones, have alfo this advantage, that they do not flare, and that they are lefs prejudicial to the eyes of thofe who are ac- éuftomed to read or write at night. It is however to be ob- ferved, that a pair of fharp fciffars muft be employed for fnuffing them, and that in performing that operation care mutt be taken not to break or derange the wick. —_ XIII. Experiments on the Colouring Matter of Vegetable Juices with the Tungflic Acid. By Cit. Guyton. ] N the fecond volume of the Philofophical Magazine, page 126, we laid before our readers a paper by the fame author on the colouring matter of vegetables, and the action exercifed on it by metallic fubftances and theit oxyds ; with a new pro- cefs for obtaining lakes of more intenfe and fixed colours. The prefent may be confidered as conne¢ted with that paper, being, in fact, a detail of the experiments with tungften, on which the conclufions there given were eftablithed. “¢ Having fubjected to experiment an oxyd hitherto little known, I mean the tungftic oxyd, I foon difcovered that it is one of the moft valuable fubftances for receiving and fixing vegetable colours. I, digefted the juice of the red plum with the white oxyd of tungflen, procured from wolfram, that is to fay, in the ftate in which it is confidered as an acid. The liquor loft a great deal of its colour, and the me- tallic oxyd became of a very dark red violet. I decanted the liquor, and boiled it on a new portion of the tungften. It. ailumed the fame colour, and the liquor ftill retained a faint fade of red. The liquor being filtered and diluted with wa- ter, to defend it from the action of the fire, was treated a third time with freth oxyd. It then remained colourlefs, and the oxyd of tungften was found coloured as much as the firft. .* From Annales de Chimie, No, LX XXIX, _vou, LY. : G Mb | * OS Bae 82 On preparing Lakes with the Tung flic Acid. It was not now neceflary to examine the liquor by re- agents, for principles which no longer exifted in it, but to try whether the colour adhering to the oxyd was fixed there in fuch a manner as to promife any advantages to dyeing, or at leaft to painting. Water boiled a long time, and in fuc- ceffion, on this oxyd rather darkened than weakened its co- lour. This water made no impreffion upon turnfol paper. Though limpid, it affumed, by the addition of the muria- tic acid, a thade of a pale rofe red colour; and by the addi- tion of pot-afh, a greenifh fhade; but thefe colours totally difappeared in a few minutes, and could not be made to re- appear, by pouring over them frefh acid and frefh alkali. What is more remarkable, the hydro-fulphure brought back a flight tint of violet, which did not difappear. ‘© A portion of the coloured oxyd of tungften was mixed up with gum water, and with a brufh daubed over a piece of paper. The ftratum being dry, a thin feale of it was de- tached, in order to be expofed to the rays of the fun, and at the end of nine days the colour was neither changed nor weakened. Another feale was immerfed in the acetous acid; and being immediately drawn out and dried, it was found to have experienced no change. As little effe€t was produced upon it by the acetic acid, Lime water applied to it left no fenfible traces of its effect. The cafe was the fame with ammonia. A folution of foap only weakened the tint with- out changing it. A folution of potafh made a red fpot, in which the violet fhade was deftroyed. A folution of the car- bonat of potafh produced an alteration {till more fenfible, the part which had been touched inclining rather to yellow than to red. A folution of alum, even concentrated, effect- ed no change. A fheet of paper, tinged with the colour of this oxyd, being kept for twenty-four hours in a clofe jar, at the bottom of which was fome hydro-fulphure, no change whatever was obferved. In the laft place, a fheet of this pa- per expofed to the vapour of the oxygenated muriatic acid, at the fame time as a like fheet of paper coloured by turnfol,_ Apparatus for the Combuftion of Phofphorus. 82 the latter loft all its colour, while that of the former was not fenfibly weakened. « The kind of lake formed by the union of vegetable co- louring matter with the oxyd of tungften may be confidered, therefore, as having been fubjected to the ftrongeft teft by the principles moft deftru&tive to colours, and which Ber- thollet confiders as the neareft, in point of ftrength, to the continued aétion of the air and light. ‘1 fhall pafs over a great number of other experiments lefs dire€t, or at leaft lels conclufive, refpecting other vegeta- ble colouring matters, and obferve only that the oxyd of lead, which feems to have fo little a€tion on the red juice of ftoned fruits, attacks turnfol very ftrongly; that an infufion of turnfol, rendered red by the acetous acid, paffes to a wine colour when treated with iron, and is then in the ftate of violet juices which become green by alkalies; that the acid juice of yellow fruits, abi for example, gives to the oxyd of tungften only a faint fhade of blue, which turns grey by repeated wafhing; and that, on the other hand, this oxyd, digefted in infufions of curcuma (turmeric) and turnfol, be- comes charged with their colours, and gives them a fixity of which one would not have fuppofed them fufceptible.” XIV. Defcription of an Apparatus in the Teylerian Mufeum for the Combuftion of Phof/phorus in Oxygen Gas; with Obfervations on the Shining of Phofphorus in Azot. By D. van Marvo of Haarlem*. . Havin G made feveral fruitlefs attempts to render a bal- - gon for the combuttion of phofphorus perfectly air-tight, ac- cording to the method defcribed by Lavoifier in his Elements of Chemiftry, I conftruéted another like that which I employ * From Defeription de quelques appareils Chimizues, &c. by Dr. van Marum. G2 ed Sh Déftription of Van Marum's Apparatus ed for the-compofition of water, and fecured againft the en, trance of air in the like manner, This balloon, reprefented by A (Plate I1.), bas two cocks B C with conical ftoppers, and united to the tubes by the fame means as thofe in the- gazometer abeve mentioned*, Within the balloon is # {mall crucible of platina, d, fufpended by two wires of the fame metal from the plate of copper by which the balloon is fhut. The cock B ferves to connect the tube with an air pump, and by thefe means to empty the balloon of at- mofpheric air. By the cock C, the oxygen gas, contained in the gazometer G, is introduced ; but as this gas ought to be as dry as poflible before it is admitted into the balloon, I have applied between it and the gazometer a glafs cylinder, H, filled with a falt which ftrongly attraéts the moifture of the gas. The falt which I found moft effectual in this ex- periment was that ufed and recommended by Sauffure for drying atmofpheric airt. It is the alkali which remaing: after the decrepitation of a mixture of equal parts of nitre and crude tartar, and which has been kept at a red heat for. an hour. The falt in the tube H muft not be ae verifed, but divided into fmall fragments, in order that the gas may penetrate through it, and come in contact with a greater portion of its furface. The tubes z, z, &, by which the cylinder H ° is connected with the gazometer and the.balloon, muf be pliable, becaufe it would be too difficult to place the cylinder Hin fuch a pofition as to be united with the balloon and gazometer by means of tubes not capable of being bent. I employ pliable tubes of gum elaftic, the ends of which are faftened to the copper pipes {crewed into the cocks. Layoifier kindled the phofphorus in the balloon by a burn- - # Fora defcription of the gazometer, or apparatus for producing water by combining hydrogen with oxygen, here referred to, {ce the Philo/ophical Mugass ‘ne, Vol. ii. p. 85. + Sec De Sanffure’s Effiris fir I Fy grometri¢s p. 25, for the Combuftion of Phofphorus in Oxygen Gas. $ gag glafs. I have obferved that phofphorus wrapt up in a particular manner inflames fpontaneoufly when the air is rarefied to a certain degree; and I employ the refult of thig ebfervation to inflame the phofphorus in the balloon. By means of this apparatus I have feveral times, both mm the courfe of my leétures and on other occafions, {hewn the produGtion of the phofphoric acid by the combuflion of phofphorus in oxygen gas, as defcribed by Lavoifier in the Memoirs of the Academy of Sciences for the year 1777, {page 65.) In my experiments I have generally burnt fixty grains of phofphorus. They have fhewn that the weight of the phofphoric acid produced is always nearly equal to that of the phofphorus burnt, and of the oxygen gas employed. I calculated the refults by the method defcribed by Lavoifier in his Treatife of Chemiftry (vol. i1-); but it is not necef- fary they fhould be inferted here, as the compofition of the phofphoric acid has been fufficiently eftablithed by the aceu- rate experiments of Lavoifier. My object, in defcribing the apparatus I employed, was merely to enable thofe who with to repeat the experiments to do fo by an eafier method, and with more certainty than according to that propofed by him, It muft here be obferved, that as the phofphorus, by my pros cefs, inflames in rarefied air, there is no danger that the fud- den expanfion of the air, produced by the intenfe heat of the inflamed phofphorns, will burft the glafs; to prevent which, in Lavoifier’s method, requires great caution, as he himfelf has remarked. That the balloon during the com- buftion may be as little heated as poffible, I fuffer the air, after the inflammation, to pafs gradually, and in {mall quantity, into the glafs globe, and for that reafon do not open the cock until the flame begins to be extinguifhed, In this manner the experiment may be performed without any danger. In the year 1794 I made known, in the thirteenth num- ber of the Chemi/chen Ocffeningen -of the celebrated Kaftel- G 3 lyn, $6. Apparatus for the Combuflion of Phofpborus. lyn, my experiments on the combutftion of phofphorus in the fo called vacuum of an air pump. Had profeffor Gottling, and other German chemifts who have obferved phofphorus to fhinein azotic gas, paid more attention to what thefe ex- periments clearly eftablifh, they would not have made fa much noife refpecting a phenomenon which is fo like the fhining of phofphorus before it inflames in air highly rare- fied. This fhining of phofphorus in an imperfect vacuum, fhews that the fmall quantity of oxygen gas contained in atmofpheric air fo highly rarefied, is ftill fufficient ta occafion that luminous appearance; and as it is well known that it is abfolutely impoffible to produce azotic gas which doesnot contain fome oxygen gas, they might have feen by my experiments, that the {mall quantity of oxygen which mutt have been contained in their azotic gas was fufficient to produce that light which they obferved. I fhall here only add, that phofphorus will not fhine at all in azotic gas which contains no oxygen gas. This I fhewed, on the 18th of January 1794, in my lectures at the Teylerian Inftitute. I introduced azotic gas over mercury, and freed it totally from oxygen gas by introducing phofphorus into it on the point of a bent iron wire, which I paffed up through the mercury, fo as to bring the phof- phorus in contaét with a piece of ignited iron previoufly in- troduced into the receiver. All the oxygen gas united itfelf in a moment with the volatilized phofphorus ; and another bit of phofphorns, which after the cooling of the apparatus I made to rife through the quickfilver into the azotic gas, which in that manner was freed from all oxygen, did not fhine. A fmall bubble’ of atmofpheric air was fufficient to reproduce the fhining. It was then feen diffufed throughout the whole gas, in the fame manner as when atmofpheric air is admitted into an exhaufted receiver in which phofphorus has ceafed to be luminous. J fhewed, in the courfe of the fame JeGture, that phofphorus does not fhine in a perfect poe Pg ck ke SEES, vee Method to determine the Magnifying Power of ‘t eleftopes. oF vacuum. For this purpofe I caufed the phofphorus to afcend through the quickfilver of a barometer, and it exhibited no light*. In order that this experiment may completely fuc- ceed, you muft employ a barometer, the tube of which has been well freed from atmofpheric air, by boiling the quick- filver in the tube. If you ufe a barometer the quickfilver of which has not been boiled, the fmall quantity of air con- tained in it will be fufficient to make the phofphorus lu- minous; but this appearance will be of fhort duration, be- caufe the exhaufted {pace of fuch a barometer can contain only a very fmall quantity of oxygen gas. KV. A fimple Method of determining the magnifying Power of Telefcopes. By Mr.S. Varney. Communi- cated by the Author +. "Tuoucu the fubje&t on which I with to trouble you with a few obfervations muft be well underftood by many of * It has been already inconteftably proved by experiments, that phofpho- rus is not Juminous ina vacuum. Befides thofe mentioned in the treatife entitled Ueder das Leuchten des Poofphors im atmofjdrifchen Stiekgas, Weimar 1795, p. 58, may be mentioned the following; Hawkfbce ap- proached very near to this difcovery, and to that alfo, made by the author, of phofphorus inflaming in vacuo. He drew fome lines with phofphorus on a piece of paper, and fulpended it within the receiver of an air pump, “ After long pumping,” fays he, ‘ the luminous appearance was appa~ rently brighter.” See the Philifophical Tranfaétions, vol, xxiv, p. 1865. Lemery mentions experiments of the like kind made by Homberg, in cone junétion with M. D’ Alence, at Paris, and which correfpond exactly with thofe of Hawkthee. See his Cours de Chymic, Paris 1687, p. 577. Lavois fier found that phofphorus did not inflame, Memorres del’ Academic, an, #777) p: 65; and Profeflors Lempe and Lampadius, that phofphorus was not luminous in the Torricellian vacuum, See Scherer’s Nachiréye, Pp: 209. t A “ Conftant Reader,” in a letter of 23d May, but which did not feach ys in time for opr laft Number, propofed the following queftion: G 4 “ Whar $$ " Method to determine thé ™ your readers, I save had many opportunities of being convinced that it 1s not fo generally known as it ought. Since I firft ven-° tured to give public lectures on optics, and to explain the va- rious confiructions of telefcopes and microfcopes, I have fre- quently been applied to, to procure thofe inftruments for people refiding at a diftance from the metropolis, and to prove them before fending them off, I have alfo been fre- quently requefted by thofe who had purchafed fuch inftru- ments to give an opinion of their goodnefs, and to determine their magnifying powers ; from which I have found that the manufacturers of thofe infiruments too generally are in the habit of over-rating their powers *, to the great difappoint- ment of the buyer, who finds, when too late, that they will not perform what he had been taught to expect from them, From what | haye ftated, it appeared to me, that a method to determine the magnifying power of telefcopes, without much trouble or expenfe, and yet fufficiently exa&t for moft purpofes, might be thought worth a place in your ufeful pub- lication. There are various methods of. doing the fame thing, and each have their particular advantages and difad- vantages : fome are expenfiye; others require long calcula- tions: fome are attended with much trouble; and others require particular fituations, which cannot always be com- manded, The method I moftly ufe can be univerfally ap- «What is the method ufed by opticians to afcertain the magnifying power of telefcopes ? and how do they prove how many times the object is magnified, when feen through the fame ?” The prefent paper, he will fee, furnithes a fatisfactory anfwer. Eprr. * Even that eminent artift Mr. James Short, who rendered himfelf fo juftly famous by bringing the reflecting telefcope to.a degree of perfeCion unknown before his time, too often over-rated the power of his telefcopes, though not in the fame fhameful degrge that fome makers now do. I would not however be underftood as making this cenfure general: I know one artift whofe reflecting telefcopes excecd even thole of Short, and whofe telefcopes I have never once found of lefs magnifying power than they were fold for; and J hope there are others who are above being guilty of fo mean an artince, : plied, Magnifying Power of Telefcopes. 89 plied, and at almoft no expenfe ; a fmall feale, a pair of com- pafles, and a piece of paper, being all that is neceflary.—It nay be proper, in the firft place, to flate the fenfe in which J ufe the term magnifying power of a telefcope; for it is dif- ferently underitood by different perfons: alfo to diftinguith between the object itfelf, and the magnified image of the object looked at, as feen in the field of the telefeope. The difference in fize, between the obje& viewed with the naked eye and its image as feen in the field of the telefcope, con- flituting the magnifying power of the telefcope, the queftion is, How ought this difference to be exprefled? Should it be exprefied in a comparifon of their refpective diameters, areas, or folidity ? For inftance, if a piece of paper of three inches {quare, croffed each way by three lines, and thus divided in- to nine fquares, be placed at a diftance, and viewed by a tele- {cope that caufes one of thofe fquares to appear as large as’ the whole paper, at the fame diftance, appears to the naked eye; if we compare this effect by the diflerence in diameter, _ we fhould fay, the infirument magnifies three times: butas one¢ fquare appears as large, when feenthrough the telefcope, as the whole nine do to the eye unaffifted by that inftru- ment, might it not be afferted, with equal truth, that it is magnified njne times? The latter appears as reafonable as the former; but, as in this cafe the paper appears, when viewed by the telefcope, of the fame dimenfions as it would do to the naked eye when placed at one third the diftance ifrom the obferver, it is moft ufual to fay, it is magnified three times. Some people, who yet mean the fame thing, fay, but improperly, that it appears three times nearer than it really is. Again, if an objeét at the diftance of 100 yards appears by the telefcope as large and diftinéct as it would do to the naked eye at the diftance of one yard, it is faid to be magnified one hundred times; and it is to be un- derfiood in this fenfe in the following experiments :—By a tclefeope of the laft mentioned power, a printed paper, at the 6 diflance 90 Method to determine the diftance of 100 yards, can be as diftinétly read as it could by the eye at the diftance of one yard ; and it is owing to this aftonifhing property that the heavenly bodies can be con- templated as though they were only the one, two, three, four, or five hundredth part the diftance that they are in re- ality. The planets, for inftance, have nothing in their appear- ance to the naked eye, that would engage our particular at- tention, or enable us to diftinguifh them from the fixed ftars, except their being obferved to change their places amongft the fixed ftars, fometimes moving from weft to eaft, then for a feafon remaining ftationary, having no apparent motion at all; then again, to have a little motion from eaft to weft, which keeps increafing acertain time, when it again decreafes, until they once more become ftationary. They were thus diftinguifhed from the fixed ftars long before telefcopes were invented, and on this account were called erratics, or wan- dering ftars, their real and regular motions and periods be- ing at that time unknown. But, by the affiftance of the telefcope, in each of them may be obferved what excites aftonifhment and claims our particular attention, efpecially if the inftruments are good of their kind, and magnify from two to four hundred times. . In viewing Saturn, the floweft, and now known to be the moft diftant planet of all, except the Georgium Sidus, inftead of a pale folitary wanderer, he is found to be accompanied with fix or feven moons, re- volving round him at ftated, fixed, and regular periods, and to be encompaffed with (a greater wonder {till) a double ring, no where touching him, but fufpended fo as to have its in- fide edge every where twenty-one thoufand miles from his body. Theplanet Jupiter is obferved to have feveral belts that appear, though upon his body, as haying feveral fpots, by which his diurnal motion on his axis is determined to be much quicker than that of our earth, being performed in about eight hours, notwithftanding he is fo much larger, q He . Magnifying Power of Telefcopes. ot He is alfo feen to be accompanied with four moons, or fatel- lites, revolving in certain periods: even their eclipfes, which afford an excellent method for determining the longitude of places on our earth, can be diftintly feen. Mars is obferved to have fome fpots near one of his poles, by which he is known to have a diurnal rotation round his axis. The beau- tiful planet Venus, that now adorns our evening fky, is ob- ferved to wax and wane like our moon; fometimes being merely a crefcent, then horned like the moon only a few days old, then gibbous, afterwards full ; exhibiting different phafes like our moon, and thus affording an inconteftible proof of the Newtonian fyftem of aftronomy, now univerfal- ly adopted by men of fcience in every part of the world*.. The planet Mercury, though but feldom feen, yet deferves our attention, as he more frequently than Venus paffes be- twixt the fun and us, appearing like a patch upon the dife of the fun, and thus, to thofe that know how to avail themfelves of thefe phenomena, gives additional proof of the truth of the prefent fyftem. The fplendid face of our moon, in her various ‘phafes, offers fo many fimilarities to the earth which we inhabit, as leave but little room to doubt fhe is deftined for the fame grand end, an habitation for in- * The truth of this fyftem has been proved by innumerable obfervations made with this excellent inftrument, by men every way qualified to judge, who with unwearied diligence, and without any bias or motive whaterer but a ftrong defire to fearch out the truth, have examined and proved every part of it, and fixed it upon too ftrong a bafis to be overturned or refuted by the ignorant or interefted, who pretend to do fo without pof- felling one fingle qualification to enable them to form a proper judgment * in this matter, or a fingle pretenfion but what is founded in the groffett ignorance, accompanied with the moft confummate affurance, But enough pf this at prefent. Perhaps at a future opportunity I may offer fome re- taarks upon, and throw together fome of the leading features of the New- tonian fyftem, for the fake of thofe who, for want of betrer information, are daily duped out of their money by the contemptible jargon of even the moft ignorant and flupid of mankind, telligent @: * Method to determine the telligent beings ; thus anfwering the double purpofe of an additional light to us, and a convenient habitation for others; while fhe, in return, receives a like benefit from the earth, which anfwers the purpofe ofa luminary to her. She is feen to have broad feas, bounded with rocky fhores; extended continents, diverfified with hill and dale; deep valleys and . towering mountains ; mountains, whofe extended fhadows can be traced, and as diftinétly feen, as the fhadow of a fun-dial ; and, lately difeovered (owing to the great improve- ments made in telefcopes), volcanic or burning mountains. An eafy method to determine the magnifying power of thofe inftruments, whofe excellence it is to have made us intimately acquainted with the various phenomena above mentioned, and which give us fources of enjoyment from the contemplation of diftant terreftrial objets, of which our forefathers had no conception, cannot but be acceptable to many, efpecially to thofe who have not the opportunity of employing the more expenfive procefies that are reforted to for the fame end. _ The fimpleft method is, to meafure the emergent pencil or cone of light, as it appears, in the eye-hole of the tele- {cope, and to divide the diameter of the aperture of the ob- © ject-glafs, if it is an achromatic, or of the great milla, if a reflector, by the diameter of this emergent pencil, and it will give the magnifying power. For this purpofe, I take a piece of thin writing paper, a little more than two inches in length, and about half an inch in breadth; I draw with a good pen, or other proper inftrument, the line a, 4, fig. 28, (Plate I.) and then, with a pair of good dividers, I take from a fcale one tenth of an inch, which I fet off from 4 to c, and then, with the fame extent, divide the line a, 4, into 20 equal parts, making yifible marks or punctures at each divifion. I then draw the line a, c, and make the divifions I, 2, 3, 4, &c. to 10, at every other divifion or point made ; with the dividers, and put a little fweet oil upon the paper Magnifying Power of Telefeopes. 98 fe make it more tranfparent. I fometimes omit making the lines 1, 2,3, &c. and content myfelf with numbering every fecond hole made by the dividers; the numbers are to ex- prefs, in hundredths of an inch, the diftance of the lines a, 2, and a, c, at thofe points where they are placed. Being thus provided, I adjuft the telefcope to diftiné&t vifion, by looking at fome diftant object, and then take off the eye-hole, if the telefcope will admit it to come off, which reflectors always do, but the night eye-pieces of achromatics do not without taking away the firft glafs alfo. Having now directed the telefcope to the open day-light, I take the divided paper in one hand, and a hand magnifier to view it with in the other, and ap- ply the paper to meafure the diameter of the bright pencil of light as it emerges fromi the eye-glafs, and at that diftance where it appears lea{t in diameter, as at c, fi. 29, where the rays of light, having paffed the lens a, conyerging to c, there erofs each other, and proceed diverging to d and e: this place, where the paper is to be applied, will be eafily known by obferving, with your hand magnifier, (which fhould be of an inch, or at moft an inch and half focus,) where the bright fpot, as at d, fig. 28, appears diftinét and well de- fined at the edges, and the filaments of the paper di@tingtly feen at the fame time. A place on the paper may be found, where the bright {pot will juft fill up the fpace between the lines 2, 5, and a, c. Suppofe this takes place at d, where it. will be extremely near the third divifion, and of courfe three hundredths of an inch in diameter; and fuppofe your telefcope to bé a 30-inch achromatic, and the diameter of the objeét glafs two inches and one tenth, or 210 fuch divifions; thefe, divided by three, will give 70 for the magnifying power of your inftrument. Suppofe, with a different eye- piece, the pencil of light only oceupied the fpace between the lines at i, it would be one and one half of thofe divi- fions: in this cafe divide 210, the hundredths of an inch , sontained in the diameter of your object glafs, by 1-5, and it 94 Method to determine the it will give 140 for the magnifying power. Again, fappofe, with fome other eye-piece the beam of light fills the lines at the fourth divifion: divide your 210 by 4, and it will give 52°5 or 52, for the power. If your paper be oiled with good linfeed oil that has been boiled, fuch as the painters call drying oil, it will laft for many years, and have this advan- tage over the inftruments made for this purpofe which are fold for 31. 3s. that, as the fcrew for receiving the dark glafs projects beyond the place where the paper fhould be held, the paper will bend, and thus can be introduced into its proper fituation without producing any fenfible error. An- other method, which I fometimes ufe in confirmation of the former, and which cannot fail to produce full conviction on the mind, is as follows: “I meafure the fpace occupied by a number of the courfes of brick in fome modern. brick build- ing, which, upon an average, will be found to have eight courfes in two feet: hence each courfe is three inches. I then cut a piece of paper three inches in height, and nearly of the length of a brick, which is about nine inches, fo that it may reprefent a brick, but with this advantage, that its edges will be much better defined; and fixing the paper againft the wall (fee fiz. 27), place the telefeope to be ex- amined at the diftance of 50 or 100 yards from the wall; and looking through the telefcope at the paper with one eye, and at the fame time with the other eye look- ing paft the telefcope, I obferve what extent of wall the magnified image of the paper appears to cover. I then count the courfes of bricks in that extent, which gives the magnifying power of the telefcope. ‘This method will ap- pear a little difficult at firft, but, by a few trials, will be- come fo familiar, that the paper, as feen by the telefcope, may be eafily compared with the bricks feen by the other eye. | I intended to have added feveral other obfervations on fubjeéts nearly related to the above; but having exceeded , the A remarkable Cure of Pulmonary Difea/e. 95. the bounds I propofed to myfelf, muft referve them for a future number, if you fhould think fubjeécts of this nature worth infertion*. XVI. Sixth Communication from Dr. THORNTON, Phy/f- cian to the General Difpenfary, &c. Sc. relative to Pneu- matic Medicine. A REMARKABLE CASE OF PULMONARY DISEASE CURED BY THE INHALATION OF HYDRO-AZOTE. Mr. GREGORY, M. P. of Berner’s-ftreet, who had been long refident in India, laboured for feveral months under all the fymptoms of phthifis pulmonalis. He expectorated a quantity of thick, opaque, and yellowifh matter which funk in water, had difturbed nights, was greatly wafted, and his breathing was fhort and interrupted. He took by my order (which was executed by Mr. Leaton, a very ingenious apo- thecary and able chemift, who lives in Bridge-ftreet, Wett- minfter) fram four to fix quarts hydro-azote daily, mixed with twelve of atmofpheric air, and at the fame time had a mixture of myrrh and bark, with opiates occafionally ; and under this treatment the cough was foon diminifhed, and in fix weeks the patient was reflored to health, and has conti- nued free from every complaint thefe eight months; even a cold now paffes off without exciting any fymptoms of alarm. Dr. Hooper, of the Mary-le-bone Infirmary, and feveral others of the Faculty, who have feen this cafe, think that it may be produced as a very {trong argument in favour of the pneumatic practice. * Subjects handled in the familiar and popular manner which Mr, Varley fo fuccefsfully follows, cannot fail to be ufeful, not only to the cafual examiner, but to men of feience; and we fhall be happy to receive his communications as often as his other avocations will allow. Epir. Obfervation, Co 5 a ee a6 _ Life of De Sauffure. Objervation. The hydro- azote ig made by burning Lo: of Strings and Rods, 115 the firft tone of the fame rod when perfeétly free. All kinds of longitudinal vibrations can be beft produced by proper fri€tion or rubbing in the direction of the length with the finger, or any foft fubftance rubbed over with pounded refin, and on glafs rods, of which thofe ufed for thermometers and barometers are the fitteft, with a wet rag beftrewed with fine fand; from which it is evident that the rubbing muft be per- formed within a‘vibrating part, and that the rod muft be gently held between two fingers of the other hand at any of the refting points, but at no other place. In pipes the higher tones are produced by a {tronger and fomewhat different me- thod of blowing. In a pipe open at both ends, the column of air contained in it vibrates like a rod free at both ends 3 and the column in a pipe clofe at one end, like a rod which is fixed at one end. In all longitudinal vibrations, the tones, during the fame kind of vibration, depend merely on the length of the fonorous body, and on the quality. of the fub- ftance: the thicknefs, and. other cireumftances in regard to form, are of no confideration. I have examined every fub- ftance which I could obtain in a fufficiently long rod-like form, in regard to longitudinal vibration ; for example, many kinds of wood and inetal, alfo glafs, whalebone, &c. The fpecific gravity makes no difference ; for fir-wood, glafs, and iron, give almoft the fame tone, as alfo brafs, oak, and the fhanks of tobacco-pipes made of clay. As found is conduéted alfo by longitudinal vibrations, fince a portion of air, or of any other fubftance, is obliged by the impulfe of the fonorous body to contract and again expand itfelf, a more accurate knowledge of longitudinal vibration may ferve to determine with what velocity found is conducted through hard bodies. Count Giordano Riccati, in his ex- cellent work on Strings or Elaftic Fibres *, has proved that found paffes through a {pace filled with air, of a given length, * Delle Corde ovvero Fibre Elaftiche. Bologna, 1764. 4. Sched. vs § 5. and Sched. viii. dift. 2. 12 in 116 On the Longitudinal Vibrations in the fame time that a column of air of the fame length, contained in a pipe open at both ends, makes one vibration. Newton in his Principia* fays the fame thing in another manner, for he afferts that each ftroke (pul/us) pafles through twice the length of an open pipe; but he calls a double vibration, that is, a contraction and expanfion, a ftroke ; whereas Riccati and others, agreeably to the common mode of expreffion, call each contraétion, as well as each expanfion, a vibration. The principles on which this propofition de- pends, feem to be of fuch a general nature that they may be applied to hard bodies; and thus we may at leaft admit, with the greateft probability, that found paffes through every body ‘in the fame time in which that body, when it vibrates freely, makes one longitudinal vibration. We are taught by expe- rience, that found moves through the air with a velocity of about 1040 Paris feet in a fecond; we learn alfo from expe- ‘riments and calculation, that in a fhut pipe of five feet, and an open pipe of ten feet, 100 vibrations are made in a fecond. According, then, to the above propofition,, found muft pais through ten times a hundred, that is, 1000 feet in a feeond. That the velocity is fomewhat greater, being about 1040 fect, does not however contradict the propofition ; for the columa of air a€tually agitated by the founding of a pipe, is always a little Jonger than that contained in the pipe; as Count Ric- -eati has proved in the before-mentioned work, and as people may be eafily convinced through experience, by: holding the ‘hand clofe to the mouth of a pipe, where,the vibration of the air will be ftrongly felt.. Hard bodies, if the above propofi- tion be univerfally true, muft conduct found with greater ve- locity in proportion as the tone is higher, which is emitted by the fame length and with the fame kind of longitudinal -yibration. Now the tones of a rod of tin are about two oc- _tayes and a large feventh higher; one of filver, three octaves and a whole tone; one of copper, nearly three octaves anda * Princ, Philof. Nat, lib. i, prop. 50. in {chol. ~’ fifth; of Strings and Rods. i17 fifth; and one of iron or glafs, about four otaves and a half tone higher than the column of air in an open pipe of the fame length. If one therefore had a fufficiently long feries of fuch fubftances, the velocity with which found 1s conveyed through tin would be found to be 7800, through filver 9300, through copper 12,500, through glafs and iron 17,500 Paris feet in a fecond. The kinds of wood I have examined would condu& found from about 11,000 to nearly 18,000, and burnt pipe clay from about 10,000 to 12,000 feet in a fe- cond. Profeffor Wiinfch, in fome papers which he read before the Academy of Berlin * in 1788 and 1789, made known experiments to which he was led by Hook’s Micrographia, “and from which he infers, that found moves with infinite velocity through bard bodies, or with the fame velocity as light. It follows, however, from the experiments which were made with a feries of wocden Jaths not of confiderable length, that found was conducted through thefe fooner than «through the air. Hard bodies, in regard to the ftrength with which they convey found, feem to exceed air; fo that we may coufe- quently admit that air, though the moft common conduétor of found, is however one of the worft conductors of it. Ifa man holds one end of a ftick in his teeth, and applies the other to a founding body, he will clearly hear the found of it though his ears be ftopped; and in this manner two perfons, almoft deaf, could hear all the notes of my evphon ¢, even in pia- niffimot. If one holds between the teeth a thread, to the end * Berlin 1793+4- 4 For an account of the Euphon fee Phil. Magazine, Vol. IT. p. 391. + About fifty years ago a merchant at Cleves named Joriffen, who had become almoft totally deaf, fitting one day near a harpfichord while fome one was playing, and having a tobacco-pipe in his mouth, the, bow! of which refted accidentally againft the body of the inftrument, he was agree- ably and unexpeétedly furprifed to hear all the tones in the moft diftinée manner. By a little refleétion and praétice he again obtained the ule of be this v 118 On the Longitudinal Vibrations, &c. end of which is fufpended a large filver fpoon, and beats it againft any thing, he will hear a noife, even if his ears are fhut, equal to that of a large bell. Perolle has given excel- lent obfervations on the capability of hard badies to condu& found, in the Memoirs of the Academy of Turin for 1790 and 1791. Articulated tones alfo are conducted exceedingly - well through hard bodies, as I found by experiments which I made with fome of my friends. Two perfons who had ftopped their ears could converfe with each other when they held a long ftick, ora feries of fticks, between their teeth, or refted their teeth againft them, It is all the fame whether the perfon who {peaks refts the ftick againft his throat or his breaft, or when one refts the ftick which he holds in his teeth againft fome veffel into which the other fpeaks. The effect will be ereater the more the veffel is capable of a tre- mulous movement. Tt appeared to be ftrongeft with glafs and porcelain veffels; with copper kettles, wooden boxes, and earthen pots, it was weaker. Sticks of glafs and next fir-wood conducted the found beft. The found could alfo _be heard when a thread was held between the teeth by both, this valuable fenfe, which, as Bonnet favs, conneéts us with the moral world; for he foon learned, by means of a piece of hard wood, one end of Awhich he placed againft his teeth, while another perfon placed the other end inthe like manner, to keep up a converfation, and to be able to ynderftand the leaft whilper. His fon made this bepeficial difcovery the fubje€t of an inaugural differtation under the following title: “ Diffrtatio medica fiflens nowt metbod: furdos realendi audientes phyficas et medicas rationes. Prat. Anpr. Ev. Bucnnero; auét. Jo. Jorissene Hala, 1757-4. Ong hears moft diftinctiy when the end of the ftick refts againft the upper fore-teeth, or rather when it is held between the teeth: if placed only againft the lower teeth, it will be of noayail. The natural caufes of this and many other variations which the author and his father tried, are ex- plained in the above ufeful Traét, which was afterwards publifhed in Ger- man, by the prefident, with the title of, Buchyers Abbandlurg von ¢iner bcfondern und leichten art Taube kerend Zu Machen: Nebjl andern Anmer= dungen, sre Samml. Walle 1759. 8.—[ This note is by Profeffer Blymen- bach. Epar.] fo On the Origin of the Goffamer. 119 fo as to be fomewhat ftretched. Through each fubftance the found was modified in a manner a little different. By refting a flick or other body againft the temples, the fore- head, and the external cartilaginous part of the ear, found is conveyed to the interior organs of hearing, as will readily appear if you hold your watch to thefe parts of another per- fon who has ftopped up his ears. From this it appears, as well as from many known experiments made in regard to hearing under water, that in moft of our books on, the elements of phyfics, in which in general accouftics have had the undeferved fate of being treated in a much more imper- fe&t manner than other parts of philofophy, found is very improperly confidered only as a vibration of the air, and the theory of it referred to the head of Air. Hearing is nothing elfe than, by means of the organs of hearing, to be fenfible of the tremulous movement of an elaftic body, whether this tremulous movement be conveyed through the air, or any other fluid or hard body, to the auricular nerves. It is alfo effentially the fame whether, as is ufually the cafe, the found be conveyed through the internal part of the ear, or whether it be communicated through any other part of the body. It certainly would be worth the trouble to make experiments to try whether it might not be poffible that deaf and dumb people, when the deficiency lies only in the external organs of the ear, the auricular nerve being perfect, could not, by the above method of conducting found, be made to hear dif- tintly words articulated as well as other founds. II. Obfervations on the true Origin of the Goffamer. By J. M. BecusTE1n*, To explain the origin of the goffamer is an old problem, which, after a number of experiments, no one, as far as I know, has yet fully folved. Some naturalifts have confidered * From Magazin fir das Neucfle aus dy Phyfik, Vol. V1. Part I. p. 53. 14 this 120 ‘On the Origin of the Goffamer. this phenomenon as the evaporation of plants condenfed during the cool days of harveft by the air, and converted into threads like thofe which can be drawn from refinous juices others, as the produétion of a kind of fpider, on account of its fimilarity to the threads of common fpiders*: and M. D.C. Pereboom has lately difcovered a kind of beetle furnifhed with a veficle on its back, from the hinder part of which, on both fides, proceed two threads that extend over the extre- mity of the body, and end in a double thread, fometimes ten or more ells in length; and this thread is fuppofed to be what 1s commonly called the Goffamer. After many years experience and obfervations made almoft daily when this phenomenon appeared, I flatter myfelf that * In the country, during autumn, certain threads are feen hanging from the trees, or extended on the bufhes, and even the grafs, which, when _ agitated by the wind. detach themfelves from the branches, are tranfported to others, and are joined or feparated at the pleafure of the breeze. People in walking often find their faces, hair, and clothes, covered with them. They are generally called the threads of St. Martin (filets de St. Martin), becaufe it is about St. Martin's day that they appear in the greateft abun- dance. When the moifture of the atmofphere and the dew attach them- felves to thefe threads and become congealed, fo that the threads appear thicker and whiter, the peafants call them the hair of the Virgin Mary (cheveux de la Vierge Marie), Having one day afked them the caufe of this produétion, they unanimoufly replied, and without variation, that it was the vapours of the earth, which at that feafon are thicker and denfer. I had no great confidence in this opinion: but I foon learned the real truth; for, being in a field overfpread with heath in the time of autumn, I obferved that elmoft all the heath-bufhes were covered with fpiders webs, and when thefe were opened I found inclofed in each a {pider. Thefe {piders were fmall, of a red colour, and marked with fpots; their feet were fhort, and the head was large in proportion to the belly. Such {piders webs are found among the low fhrubs that grow near the earth, at the bottom of ftalks of corn which have been left itanding by the reap- ers, and in the bufhes. When the wind is ftrong it breaks thefe webs, carries away a part of them, which are featrered over the ground and the trees, and hence come the threads of St. Martin. Huetiana, Amferdam 3723) p. 369. Epit. Tam =—— a = so On the Origin of the Goffumer. 121 Tam able to refolve the problem refpecting its origin. In my opinion the goffamer arifes from nothing elfe than a cer- tain kind of field-fpiders, which are, however, fo {mall and aétive, that they almoft always efcape notice, unlefs the ob- ferver is endowed with great acutenefs of fight. I would call this fpider, if it has already no name, the goflamer fpider (wranea obtextrix): 1 fhall here give a fhort defcrip- tion and hiftory of it, as far as my knowledge extends. The goflamer fpider (aranea obtextrix) is as large as the head of a fmall pin. On the fore-part of its longifh head it has eight grey eyes placed in a circular form; the extremity of the body is fhaped like an egg; the body itfelf is ofa fhining dark-brown colour; the feet are of a moderate length, and yellowifh ; and the whole animal is covered with infu- lated hairs. Thefe infects firft appear in the beginning of O&tober, in woods, gardens, and meadows, where their eggs may be hatched unhurt and unmolefted, and thence {pread them- felyes over whole diftricts, fo that during all the month of O&tober and till the middle of November they may be found on the dry fields throughout all Europe; and as they produce a numerous progeny, extenfive tracts may fometimes be feen {warming with them. The young, which have not attained to their full growth, are not larger than the point of a pin; they are black, with grey feet, and almoft imperceptible to the naked eye. In the beginning of October, when very few of them have been hatched, one obferves only in the funthine a few fingle threads of their webs, which they extend from twig to twig, or from ftraw to flraw; but about the middle of the month their threads become more per- ceptible; and towards the end, if people ftand or place them- felves in {uch a pofition that they can fee the fun-beams play- ing on the tender threads, they perceive hedges, meadows, corn-fields, fiubble land, and even whole diftricts, covered with a fine white thick fort of gauze. ‘This fpider belongs to that kind which do not weave webs, but only extend fingle threads 122 Ox the Origin of tbe Goffamer. threads from one place to another, and which Linnzus, on that account, includes in a particular divifion. The threads, owing to the fmallnefs of the animal, are fo delicate that a fingle one cannot be diftinguifhed by the naked eye unlefs when the fun fhines upon it. A thread, to be vifible at other times, muft be compofed of at leaft fix threads twifted toge- ther; and fuch a thread, as the fingle ones are exceedingly brittle and do not readily unite, may be again eatily divided into its component threads. During the ferene calm days of the above months thefe animals carry on their occupation with great diligence, efpecially after the morning fogs have difappeared. Between the hours of twelve and two, how- ever, is the period when their great induftry excites moft admiration. If people are pofleffed of good eye-fight, or are farnifhed with a magnifying glafs, they may find among the barley ftubble fuch a multitude of thefe fpiders employed in extending their threads, that the fields appear as if covered with fwarms of gnats, and they perform their labour fo fpeedily that they feem to fly from one ftubble to another. Thefe tender threads, which are extended over whole fields, particularly in the laft half of O&ober, become ‘twifted together by the gentleft breath of wind, and form perceptible threads, that, being broken loofe by a ftronger wind, are united into thick threads, and even balls, that float through the atmofphere. They are known then in Germany by the name of the flying fummer*, becaufe the fummer feems as it were to fly away at the fame time. The {piders alfo are then conveyed along in them. and it is not uncommon to find thefe animals entwifted in fuch threads which have been caught f, All * In German fregende fommer. + A fingular ufe which fome kinds of fpiders make of their webs is, that they ferve them inftead of carriages to perform long journies, and to tranf- port themfelves from one country to another. At certain times of the year we may generally fee, when the fkyisferenc, a multitude of ftrong threads and balls formed of the threads of thefe infects, floating about in the atmo-. {phere 5 . X_oaife ag ---¥ On the Origin of the Goffamer. 123 All the fpiders, however, found in thefe threads or balls, mutt not be confidered as the animals by which they were prepared; for other kinds of fpiders, common in harveft, are fometimes entangled in thefe threads and carried along with them. Thus, for example, the black and white fpotted tree-fpider, and the fo called cheftnut-{pider, are often found inclofed in the goffamer together with their habitations, and mutt obey the impulfe of the winds. Thefe webs, which confift of threads clofely joined toge- ther, ferve the infeéts as nets, in which they catch very {mall black flies, gnats, and winged tree-lice, the juices of which they fuck for their nourifhment. The goffamer, therefore, is often found filled with the dried hufks of fuch infeéts. The above, in my opinion, is the real origin of the gof- famer. But why do thefe fpiders appear only in the time of harveft ? why not earlier? and why are they not found like the houfe and field-{piders throughout the whole fummer? —Thefe objections obviate themfelves. They appear at that period for the fame reafon that may-bugs (maykaffer) appear jn the month of May. They are as neceflary in their order to preferve the equilibrium of the balance of Nature as the may~ bugs are in May. Single fpiders of this kind, however, may be found the whole fummer through, as fingle may-bugs are found in harveft. To thofe who know that exactly about this time thofe birds, for whofe nourifhment infects have been affigned, undertake their emigrations, and that the larks in particular, which are fo fond of fpiders, then leave us, the above phenomenon will not appear wonderful, but will ra- ther be confidered as a wife regulation of Nature. Thofe who with to be convinced of the truth of this obfervation need only to fhoot a lark at that period and to open it imme- fphere ; and when thefe threads and balls are examined, they will always be found to contain fpiders, which have prepared thefe fubftances to en- able them to fly without wings, and toprocure them/clves an eafy. paflage to other countries. Tadologie des Infedtes par Leffer, avec des Remarques de P. Lyounet, Ala Haye, 5742. Vol. I. p.346. Epir, diately, T24 Remarks on Mr. Sheldrake's diately. Thefe infe&s, together with the grains of batley which drop from the ears, muft indemnify thefe birds, which ftop in many places on their paffage in great numbers, for the lofs of the fummer infects. ; After what has been faid, I do not think that the white- nefs of the threads, which arifes from nothing elfe than the dews that fall at that period, or their clamminefs w hen rub- bed between the fi ingers, not obferved in the threads of other fpiders, and which is occafioned by the finenefs of the threads, that fo eafily infinuate themfelves into the cavites of the fkin, can be brought as any objection againft this mode of explanation. Thefe phenomena can have no weight un- lefs-we afcribe thefe threads to the common fpider. It is likewife very improbable that the goffamer is produced, as M. Pereboom afferts, by his beetle; which however mutt excite our admiration, becaufe, like the fpider, it weaves for itfelf a net, either to ferve it as a habitation, or as the means of catching its prey. III. Remarks on Mr. SHELDRAKE’S Diffrtation on Paint- ang in Oil in the Manner of the Venetians. By Mr. Ep- WARD Dares. Communicated by the Author, P ERSUADED that Mr. Sheldrake labours under a mif- take, which may lead others into a practice difficult in itfelf _ and dangerous to the durability of their works, I fhall offer no apology for the following remarks on his Differtation *. That the Venetians primed with diftemper, is true; but the colour ufed was not a brow, as ftated by Mr. Sheldrake, but a red, known at prefent by the name of Venetian red. Some artifts at this time employ the fame colour, previoufly calcined, in a new Venetian method: I fay a new one, for there are two or three. One of the fecrets confifts in prim- * See Phil. Mag. Vol, II. p. 302. ing Differtation on Painting in Qil. 13g ing the cloth with bone-afhes, mixed with a fmall quantity of fize or pafte, and afterwards brufhing it over with the above calcined-red. The method of working up the picture in a ftate. of black and white was certainly practifed at times by fome of the Venetians; but in that cafe the ground was no object, as the whole effect of colour was afterwards acquired by glaz- ing: this is obfervable in the pictures of Tintoret, and fufii- | ciently accounts for the perifhed ftate they appear under. On the contrary, where the red ground was ufed, the light and extreme dark are the only part where the colour lays ina body. Mr.Sheldrake obferves, hedoes “not pretend to degrade “painting to the rank of a mechanical ast, that may be infal- hibly praétifed by a receipt.’’ If the Venetians had poffeffed no higher recommendation to notice than mére colouring, they would not have fo ftrongly arrefted our attention ; on the contrary, the compofitions of Titian, Paul Veronefe, &c. will ever rank among the firft.. The prefent rage for colour is like preferring perfon to mind, and had it prevailed in the time of Swift, would certainly have procured fome of our profeflors a fituation at Lagoda. The author of the Differtation muft certainly have mif- taken the words of Sir Jofhua, or not underftoad them. Sir Jofhua could never have faid that harmony was to be pro- duced. by “an unity of light and an unity of fhadow per- vading the whole ;”” or, in other words, (as I underfiand it,} by reducing the whole of the lights to one colour, as is im- plied by the word wnity.. Such a pra€tice would deftroy the brilliancy which the author wifhes to obtain from glazing, The fimile afterwards introduced, contradiéts entirely fuch an inference. “ A piéture, to poffefs harmony of colouring, fiould look as if it was painted with one colour; and, when the chiaro-ofcuro was complete, the colour of cach objeé fhould be glazed over it.”’ Sir Jofhua was in the fimile de- fcribing his own practice, and which will, for a fhort time, produce a greater brilliancy in the light. %Inftead of an “ unity 426 Remarks on Mr. Sheldrake’s “ unity of light,” the word harmony muft have been ufed, as harmony of light and unity of fhade are common terms. In note 43, on Du Frefnoy’s Art of Painting, he (Sir Jofhua) exprefsly fays: ‘ And for the fake of harmony, the colours, however diftinguifhed in their light, fhould be nearly of the fame colour in their fhadows, of a ——— “ fimple unity of fhade, “¢ As all were from one fingle palette fpread.” Every one knows that the harmony of the picture depends greatly on the fhadows not being difturbed with colours That Sir Jofhua was acquainted with the method of bringa ing forward his piCtures in a {tate of black and white, and glazing for the colours even in his draperies, 1s too true, a3 is known to all acquainted with his praétice, and was, I be- lieve, the reafon of their not ftanding. His method was, with ivory black, vermilion (ufed in the carnations), and white, to bring forward his pictures to their full effect, and then to glaze for all the colours. It fhould be obferved, that this method might only be praétifed at times, but I had my- felf feveral opportunities of feeing it. All the advantages obtained by the practice of glazing, as it is called, are fo tranfitory, that they may be Hiterally faid to be but the vifion of a day. Whether this arifes from the gum in what is termed maguilp*, (a compofition of two parts maftic varnifh and one of drying oil,) moftly employed for the purpofe, or want of body of colour, I do not pretend to determine, though I think both may contribute to effe& their deftrugion ; the colour by flying off, and the gum by * The above compofition, when mixed on the palette, forms a confift- ence like honey, with which the colours work exceedingly free. There are various compofitions for maguilps; fome ufing wax diffolved in nut oil, others rofin and fugar of lead in the fame folvent, wax in fpirits of ture pentine, &c,: though I muft own a preference for the drying oil and var- nifh for diluting the colours for the touches or pluming on a part, but for the mere aé of glazing I prefer goad clear oil. lofing Differtation on Painting in Oil. 127. lofing its tranfparency. One thing I have frequently had occafion to remark in the ufe of water colours (in a tranfpa- rent ftate), that the more gum is mixed with them, the fooner they fly. As far as glazing goes to enrich a colour it is neceflary; but that is a very different practice from the one I now fpeak of. Many fubftances employed as pigments give black, or - dead, heavy colours; as Pruffian blue, indigo, dark lake, and indeed all colours that are tranfparent when viewed in a jump; but, fpread on a white ground, or mixed with any colourlefs matter, they appear in all their vigour. If, inftead of a white ground, a grey or brown is ufed, the vivacity wilt be more or lefs in proportion to its darknefs. Thefe fa&s furnifh firong reafons for preferring a white ground, and may account for the darknefs in many of the Venetian pic- tures, from their glazing with tranfparent colours on a dark furface, and, as before ftated, the lofs of clearnefs in the ve- hicle ufed (no doubt a gum); but this appears to have been only an occafional practice. The Dutch painters, whofe mechanical excellence was inferior to none, always ufed white grounds prepared with the greateft care. They fpread well-wafhed chatk mixed with fize over the furface to be painted on, which if nicety was required they pumiced, and repeated the operation till the furface was even; after which they laid over it a coat of the fineft flake white. ‘The whole picture was then painted fair, (that is, with a body of colour,) except the thades, which were kept clear and tranfparent, and received an addi- tional lufire from the ground. That this was their practice may be éafily feen in all their interior feenes and the clofe parts of their pictures. It is much to be wifhed that, inftead of brillianey, per- manency were fought after; while the Venetian pictures are going faft to decay, the works of Van Eyck, Quintin Mat- fys, and John de Mabufe, remain frefh and vigorous. _ With refpect to thadow being a privation of light, it is q readily > 123 Remarks on Mr. Sheldrake’s readily admitted, and it equally follows, that it is a privation - of colour; but this circumftance fhews, as before ftated, that much of the harmony. of the picture muft depend on its not being difturbed with colour. Where Mr. Sheldrake attempts to illuftrate this doétrine, by fuppofing a globe expofed in a painter’s room, he feems rather to have confufed the matter by too many divifions. Artifts divide the furface of all bo- dies into light, middle tint, fhadow, and (which Mr. Shel- drake has forgot to add to his globe, to round it) refleétion. There are two things the author of the differtation appears to have overlooked, and which eafes the difficulty of ‘pro- ducing the’ harmony neceflary to conflitute a whole: firft, the method (faid to have been at firft pra&tifed by the Ve- | ‘ netians) of breaking the colours, fo as to make them all par- take in fome meafure of each other, and which was at times carried to a degree of infipidity even by Titian ; and fecond- ly, (and which I think the moft effential,) the grouping the warm colours together fo as to form a mafs, and letting them occupy the greateft portion of the picture. The latter appears to have been the practice of Rubens and others of his fchool, and which enabled him’ to introduce the whole {cale of colours in the fame picture, from the hotteft to the oppofite extreme of cold; this gives a vigour to his colour- ing beyond all other aan, The method of working up the picture in a ftate of black ‘and white, was evtaitity never practifed by the Flemith ‘mafters. The beauty obfervable in the colouring of Rubens ' (whofe demi-tints are wonderfully clear) refulted from a firm- “nefs in the handling, a fimplicity and diftinétnefs in the “tints, and a particular care to avoid muddling them in ufing: “Ido not mean to fay they never glazed, or feumbled to give richnefs ; but that was done in a different manner to the one “deferibed in the Differtation. In fome of his flight pictures the tones in the flefh may be traced as follows: the light ‘ yellow, next the carnations, then the grey, next the fhadow, ag to give it clearnefs, and his refleétions generally very bright; - Differtation on Painting in Oil. tag bright; but in his finifhed works they are of courfe more blended. Every artift knows, or ought to know, that there are but three primary colours, red, blue, and yellow ; the com- * pound colours, which refult from combining thefe, amount to four, making in all feven. Red and blue, when mixed, produce purple; red with yellow, orange; blue and yel- low, green; the three united, a brown, black, or grey, as the warm or cold colours prevail. Thofe conftitute all the colours and tints in nature, mixed with more or Jefs white. The fewer colours ufed by the artift the better he will colour, from the praétice being rendered fimple, and the poffibility of muddling in fome meafure deftroyed: for, it 2s not the mixing colours that hurts, but the mixing many; two colours will always be clearer than three, and foon. Though the above confiderations offer a fimple theory of colouring, yet in practice the artift muft have judgment enough to acquire at once the precife tint he wants, to infure clearnefs and bnl- liancy. The fingular fact of white appearing grey on a brown ground, I fhould fuppofe to arife from white being cold, and from its contraft with the brown. That a picture painted in brown and white fhould be in perfeé&t harmony is not to be wondered at, as it can only be termed an effect of light and fhade. The brown ufed by the Venetians has, with great probability, been fuppofed a preparation of af- phaltum., As the practice of glazing is the laft operation in paint- ing, and as in the doing it the artift ufes in the fhadows fome tranfparent dark colours, it of courfe follows, thofe fhadows muft be kept tenderer to receive the glaze, which may be extended to the demi-tints if kept tender in propor- tion alfo: this will produce the deceptive appearance Mr. Sheldrake {peaks of in the Venetian piétures, and do away the weight refulting from mixing, as he fays, ‘ fome dufky colour with the local colours and the light.” The above method, with the praétice of fcumbling on the lights, or Vou, IV, K merely 130 » Remarks on Mr, Sheldrake’s merely-enriching a colour by glazing, in my opinion fuffi- ciently accounts for Venetian brilliancy. - What is meant by black and white not being the paint- ér’s extreme of light and dark, I profefs not to underftand : all that 1 know is, that’the artifts have to lament, as well as Mr. Sheldrake, the being obliged to reprefent fhadow with a fubftance,. and that even glazing them thin is but a poor imitation of the real appearance. With refpeét to “ the painter’s art being to reprefent objeéts as they appear, in point of colour, to be not as they really are,” I am equally at a lofs to underftand the author, having ever been taught to confider all colour as comparative; and therefore, that black at 5o feet diftance was no longer fo, and to call it black would be'as abfurd as to call twilight night. If I judge right, (from the author’s recapitulation,) there are three fiages in his procefs; firft, the darkeft tints, then the lights, and laftly the colouring. Now I think it is evi- dent, from the oil being niebaily abforbed by the eround, that it would be utterly “impoflible to blend the hghts and darks together fo. as to make the picture mellow. Then comes the glazing for the colours, which is bad, as experi-- ence has fufficiently {hewn the want of durability: befides, for fuch a proces, oil makes the colours too thin to work: this made the artifts. refort to the expedient of ufing ma- guilp, which has the injurious tendency before ftated. What made thefe artifts fo cefirous of a clearnefs in the fhades, was to give them. that non-fubftantial appearance Nature puts on: in his lights, it is true, the artift wants brillidncy, te acquire which he occafionally glazes or fcumbles ; but every good artift knows, that the lefs recourfe he has to the former practice, the more permanent his picture will be. After_all the confideration I have been able to give this fubject, I am inclined to think that the Venetian method, judging from:a picture by Tintoret now before me, was more hike that followed. by Sir Jofhua Reynolds, as above de- feribed, es rs. ja": ~~ + ek ret ngs ee Differtation on Painting in Oil. 131 feribed, than the one recommended by Mr. Sheldrake. ‘T7- tian glazed on colour, Tintoret often on white ; and I think it will invariably be found, that the works of the-latter are more perifhed than the former. That exquifite lightnefs at- tendant on a dead colouring, may, in a great meafure, be re-- ftored by fcumbling. The plan he has propofed, and which feems to have been reforted to, to remove the practical difficulties he met with, is merely to paint in varnifh; a method which always gives brightnefs fora fhort time. The objections to its adoption may be fummed up ‘na few words: firft, the difficulty of blending the colours ufed to produce the effect of light and fade ; and fecondly, (which is by far the moft material,) the want of durability in the colours, as they muft all be ac- quired by glazing; not to mention the ftrong fimilitude be- tiveen it and Sir Jofhua’s method, as above defcribed. As I never bought Milfs Provis’s fecret, I cannot tell how clofe the approximation may be between her method and the one propofed by Mr. Sheldrake; but if I may judge from practical experience, they would both be productive of hard- nefs; and as fome of the colours in the pictures painted after her method carried evident marks of deftruction on them, I was immediately induced to fuppofe that fome calcareous earth was ufed in the ground *. Though I much queftion the utility of Mr. Sheldrake’s plan, I think he unqueftion- ably deferves the thanks of the public, and of artifts in par- ticular, for the time and trouble he has’ beftowed on it. * Lime and terra ponderofa deftroy the colouring matter of Pruffian blue; fore d:awings, hung up in a houfe that had undergone a confider- able repair, loft all their blue colour, which had become a dirty iron grey» . ' K 2 IV. Progre/s PrEgane | IV. Progre/s of Dr. Mitcui11’s Mind in inveftigating the Caufe of the Peftilential Diftempers which vifit the Cities of America in Summer and Autumn. Being a Developement of his Theory of Peftilential Fluids, as publifbed to the World in 1795 and the fucceeding Years. [Concluded from Page 43.] \ \ HILE thefe i inquiries were making, a rhea be dif- pute was carried on in fome of the Atlantic cities, Whether the exciting caufe of yellow fever was of domeftic origin, or imported from: foreign places in fhips and merchandize? The prevailing opinion at New-York was, that there were local -caufes enough for the production of that diftemper in the city itfelf. With the intention of removing the caufes of this plague from the town, the Legiflature, then fitting at Albany, 160 miles diftant, rapidly paffed a bill prohibitory of certain trades and manufactures within the compact part of the city. The act forbade, among other things, the ma- nufaéture of foap and candles under a heavy penalty, except at definite diftances from the honfes and fettlements. The defcription of citizens engaged in thefe branches of bufinefs prefented immediately a memorial to the Legiflature for re- lief on this oceafion, and retained Dr. Mitchill as their countel to manage the bufinefs of procuring fome terms of mitigation at the feat of Government, -In drawing up the argument in favour of his clients, he became more firmly convinced than before, that fubftances compofed of carbone and hydrogene, fuch as fat, grea/z, and oil, were incapable of yielding peftilential airs; and that the fubftances contain- ing /epton, to wit, the /kinny, lean, mufcular, and membra- nous parts of animals, together with the b/ood and alimentary fetes, were the fubftances whence unhealthy and noxious exhalations proceeded. From a general and broad induétion of faéts arranged in the argument employed on that occa- fion, it was rendered clear, that the fubftances containing Septon, On Dr. Mitchill’s Theory, &c. 133 fepton, and none others, were known to afford peftilential air. The fame rule applied to vegetable produétions, of what~ ever kind they might be. On this occafion it was exhibited in evidence, that the perfons who were engaged fteadily among the a/bes, foap, and fat of thofe manufactories were protected as it were from peftilential difeafes, and fared mightily better than their neighbours. A part of this doétrine foon after received confirmation from Count Berchtold’s and Conful Baldwin’s account of the beneficial effects of oi/ in keeping off and relieving the fymptoms of the plague in Afia, and.from the remarkable ex- emption of the Nantucket whalemen from malignant fevers on their long voyages over every part of the ocean. From the furvey of the facts relative to alkalis and oils, there could hardly remain a doubt that they ated upon the acid of peftilence, by neutralizing or decompounding it: fill, if this acid confifted of fepton and oxygene chemically united during the putrefaction of organized bodies, why did not thofe elementary fubftances, it was afked, which conftitute the bafes of azotic and vital airs refpectively, incorporate in the atmofphere, where they exift in ftates apparently very favourable to combination? The reafon appears to be, that after fepton and oxygene, in their feparate forms, have cone neéted themfelves with caloric enough to form diftinct gafes, they are repelled thereby to diftances greater than chemical attraction can reach, and therefore remain feparate. ‘This idea, which Dr. Mitchill originally ftarted, has fince been confirmed by Citizen Guyton’s account of the poffibility of bringing the bafes of the two airs into chemical union, by comprefling them with a force equal to feveral atmo- fpheres; a part of the caloric in fuch cafes, according to Dr. Darwin’s idea, being crowded out after being compelled to quit its hold. Indecd it feemed evident that the chief difference between common air and pettilential air confifted merely in this; that in the former, the fepton with caloric formed azotic air, and the oxygene conftituted vital air, cach K 3 diftint 134 On Dr. Mitcbill’s Theory diftin& from the other; whereas in the latter cafe the fepton and oxygene are chemically blended with each other, bafe with bafe. The reafon of their readinefs to unite during the putrefactive procefs now became evident. The bafes of the two airs rufhed into union before they had attracted caloric enough to turn them to fimple gafes, and give them the re= | pellency incidental to that condition. The venomous and deadly qualities of nitrous acid had been afcertained by Eaglefield Smith in his experiments upon {mall animals inoculated with it. A cafe occurred during Dr. Mitchill’s attendance as one of the phyficians of the New-York Hofpital, where fever appeared to have been brought upon a patient by the nitrie acid abforbed from the decompofition of a large quantity of red precipitate with which an ulcerated leg had long been dreffed. Several inftances had come to his knowledge, of fevere dif- order in the alimentary canal, terminating in dy/entery, from an accidental drinking of diluted aquafortis. It immediately {truck him, that privies and colleétions of human ordure had been long noted ‘for containing feptic (nitric) acid. The efluvia of privies had in feveral inftances been known to excite dangerous ficknefs. Many of the arti- cles of diet contained fepton; and oxygene, in fome form, always exifted in the alimentary canal, As the contents of ~ the ftomach and inteftines were inanimate, it was exceed- ingly probable that, in certain cafes of indigeftion and cof- tivenefs, feptic acid might be formed in the cavities of thefe abdominal vifcera; and that irritation and inverfion of the motions of the ftomach, in fome forms of yellow fever, as well as fpafms of the colon, griping pains and tenefmus in fome of the cafes of dy/entery, PROCEEDED FROM THE SAME EXCITING CAUSE. | By an induétion of facts'from the operation of xcutrat faits in thefe kinds of difempers, it appeared, that the moft efficacious and falutary were thofe which are capable of de- i " compofitian of Peftilential Fluids. “135 eompofition by feplic acid, if it exilted in the inteftines ; and that really, befides their cathartic effect, they poffeffed va power, derived from their alkaline bafes, to neutralize that mifehievous and tormenting liquid. From this principle Dr. Mitchill inveftigated a theory of the modus operandt of thefe numerous and important articles of the Materia Mepica. » Frequent inftances afterwards evinced the juftnefs of this interpretation ; for m the New-York Hofpital, as well as in private practice, he found watery folutions of the carbonates of pot-afh and foda to be moft excellent anti-dyfenteric re- medies, arid valuable preferiptions in the cholera infantum. The adminiftration of the carbonate of foda: in clyffers, to allay tenefmus, was fugeefted: to Dr. Mitchill by Dr. Lent, then apothecary of the houfe, and found, on repeated trials, to be a valuable remedy. Dr. Saltonftall has treated of the application of this principle to explain yellow fever, and Dr. Bay to elucidate dyfentery, in their feveral inau- gural differtations publifhed in CopumB1ia COLLEGE. After. being called to the Profeflorfhip of Chemiftry, Na- fural Hiftory, and Agriculture, in that feminary, Dr. Mit- chill delivered thefe doétrines publicly in his annual courle of leétures. ‘Ihe differtations juft mentioned fhew with what zeal and fuccefs they were difcufled and applied by his hearers, And a circumftance worthy of notice refpecting both the gentlemen lat named, is, that they witneffed and lived through the plagues they have deferibed, A general inference from all the phenomena was, that thefe miafmata or contagions, in all their forms herein con- templated, were violent STIMULANTS, as Brown had ori- ginally conjectured. But the application of this doétrine. to AGRICULTURE was not much lefs interefting than its relation to Medi- cine. Dr. Mitchill was born in the parith of Hempftead, in Queen’s County, His father was a landholder, and culti- Rad vated 136 On Dr. Mitchill’s Theory vated his own eftate, as is common in America. The early part of his life, to the age of feventeen years, was paffed in the country. In the way he was educated, the implements of hufbandry, and the method of ufing them, were familiar to him: he knew the management of the plough and of the fpade. After the death of his father in 1789, he took pof- feffion of the family-patrimony, and lived on it as a praétical farmer for feveral years. His experience and opportunities during this feries of agricultural employment, had produced, among other things, a more curious and particular attention to MANURES. On reviewing his former obfervations, the fubject pre- fented itfelf to him under feveral new afpects. The produc- tion of /eptic acid among the excrements of animals had been Jong known: the neutralization and fixation of this was, he thought, one of the principal effects wrought by alkalies and lime. Inftead of faying, with the generality of modern ob- fervers, that lime was ferviceable by its feptic or putrefying quality, (an opinion for which there is no plaufible founda- tion,) Dr. Mitchill became convinced, its principal effect was, to combine with feptic acid into calcareous nitre, one of the richeft of manures; and referve this, without volati~ lization or evaporation, fixed upon the foil, to ftimulate and feed the plants which grow there. Thus wholefomenefs and fertility were provided for in the fame operation. It feemed to him alfo, that the deliquefcent property of the feptite of lime enabled it to retain moifture a long time upon the land, and thereby mofi agreeably fecured the crop from the pinch- ing of drought, It was obvious, that if there was much feptic venom (oxy- genated fepton) in any field, yard, or region, and no lime or alkali to neutralize it, epizootic difeafes among cattle might proceed from it, after the manner of epidemic diftempers among the human fpecies. Dews and fogs impregnated with feptic acid, appeared the probable exciting caufes of feveral mortal diforders in neat-cattle, fheep, and horfes; a confiderable ; of Peflilential Fluids. 139 confiderable quantity of fuch dilute aquafortis being taken into their bodies as they grazed during the night. He ~ thought this was corroborated by the fymptoms related by Lancifi to have been obferved in the cattle fick of fuch dif- eafes in Italy. And it was no lefs plain that ru? and mildew in wheat were owing to the fame caufe. The unwholefomenefs of certain dews, in certain places and times, was evidently, he believed, to be afcribed'to a _ portion of feptic acid gas, volatilized during the heat of the day, and precipitated with a portion of atmofpheric water in the cool of the night. With this branch of the enquiry was connected the whole hiftory of nitre, and the pits, beds, and caverns wherein it was produced, whether fpontaneoufly, or by the hand of man. The interpretation of all the facts relative to which amounted to this; that the alkali neutralized the acid poi/on of putrefaction. On looking around, it could not efeape Dr. Mitchill, that the fweetening and cleanfing effects of lime, alkaline ley, and foap, in DOMESTIC ECONOMY, were now capable of an eafy and complete explanation. The fweat, perfpiration, and excreted matter of almoft every fort, which rendered clothing, bedding, furniture, and houfes foul, contained fepton; and confequently, in the heat of the human body, Jeptic acid might be produced in quantity and ftrength fuffi- cient to excite many morbid aff2étions of the /kin, and, if ab- forbed, engender the wor/t forms of fever. Lime, ley, and foap rendered the human body, its clothes, bedding, &c, pure and wholefome, by their power of attracting all kind of peftilential matter, and carrying it clean off. He therefore became fatisfied that the old maxims of female management were beft; for he never knew infection break out where there was a SMART WOMAN for a houfekeeper: the reafon | was, fhe kept the mifchief down by alkalies, On the other | hand, 138 On.Dr. Mitchill’s Theory, Ge. hand, wherever MEN, efpecial!y thofe who fet up for r1- LOSOPHERS, took the Jead; as in prifons, workhoufes, hofpitals, and fhips; there were for ever complaints made of the rife and progrefs of malignant diftempers: the reafon was, they increafed the evil by acid fumigations *. Numberlefs inftances had happened in New-York, of per- fons being poi/oned, and many of them to death, or, in other words, catching the yellow fever, from the feptic vapour of corrupting eef and fi/b cured with too fmall a quantity of ~ falt. Thefe are moftly dean animal fubftances. On their corruption they afford the moft deadly effluvia. The fre- quency of ftinking proyvifions of thefe kinds, and of the poi- fonous vapours they emitted, led Dr. Mitchill to inveftigate a theory of the muriate of foda in preferving animal flefh from putrefaction. The refult was this: when feptic acid is formed in a barrel of beef, the common falt is decompofed; -and while the feptic acid combines with the foda, the muri- atic acid is fet loofe to impregnate and preferve the meat. ‘When there is too little muriate of foda, the feptic acid, be- coming volatile, often fickens,. and even kills the perfons who are expofed to it. This interpretation led naturally to an inquiry into the ufe of the dile of animals; which, inttead of being a vile, troublefome, excrementitious, and corruptible liquor, as it has been fafhionable to term it, turns out to be a grand pre- ferver of health, by virtue of the /oda which it contains; being always ready to pour itfelf into the duodenum, and even regurgitate into the ftomach, to neutralize any portion of feptic yenom which may have been fwallowed or engendered | there, Of all the fluids the animal body contains, the gall is the leaft liable to corruption, or alteration unfriendly te health. * The author of the prefent paper was not perhaps aware of the ftrong evidence in favour of the utility of acid fumigaticns that has been brought forward by Dr. Smyth, Mr. Cruickfhank, and others. Epit, ; There . Account of a Voyage to Spitfbergen. , 139 There are many more inductions of facts which unite in the efiablifhment of the general principle Dr. Mitchill has inveftigated. Some of thefe have been publifhed in America, and fome exift {till in manufcript. The defire of writing a book feems never to have influenced him. Accordingly he has generally conducted his difcuffions in the form of letters to his friends and correfpondents: and even thefe he has never colleéted into a volume; they lie fcattered about in’ Magazines and differtations where they were firft in- ferted. There is‘a promife, however, of printing the whole in the Medical Repofitory, where they may in fucceffion be laid before the learned world. In this immenfe in- quiry, it is hoped, he will be aflifted by the candour and talents of thofe fcientific inquirers who are now-a-days making fuch vaft difcoveries in Europe, Y. Account of a Voyage to Spit/bergen in the Year 1780. By S. BacstRom, M.D, Communicated by the Author, SIR, Hay ING received much gratification from a perufal of your Magazine, I fend you a few particulars refpedting a _ voyage which I made to Spitfbergen in the year 1780, ex- . tracted from a journal I kept at the time; which you may Jay before your readers, if you think they can contribute either to their information or amufement. _ The Editor of the Iam, &c. Philofophical Magazine, } S. BACSTROM. A yoraGe to Greenland, as it is called, though in fa& to the ifland of Spitfbergen, for the purpofe of killing the black whale-fith, is one of the healthieft that can be under- taken, and furnifhes fo much curious matter for amuferment to perfons of an inquifitive turn of mind, that even a fecond will hardly fatisfy fuch, if they have been fortunate enough to 140 Account of a Voyage to Spit/bergen. to fail with a good commander, and in a yeffel well appointed. In both thefe refpeéts I was very fortunate, which is rather uncommon; the mafters or commanders in the Greenland trade being generally men of httle or no education, and con- fequently void of thofe lberal fentiments neceflary to render the fituation of thofe wko accompany them comfortable. If a regularly educated furgeon, from a defire of vifiting fuch northern regions, goes in a veffel under fuch a perfon as I have deicribed, he is generally fickened the firft voyage; a barber is perhaps his fucceflor, and when any illmefs or acci- dent happens on board, if the patient efecapes with his life, he is often rendered a cripple. I have feen fome inftances of this kind. The unfociable difpofition of the mafter is not, however, the only circumftance that often deters from a fecond voyage. T have known veffels well ftored by the owners with every neceffary and ufeful article, and even a liberal fapply of what fome would call luxuries, and yet every comfort withheld from thofe on board: the mafter literally ftarving himfelf and officers, and not allowing a bit of fire in the elect in thefe cold latitudes, that he might fave a few coals, fome dozens of hams and tongues, a quantity of cheefe, butter, flour, wine, porier, &c. ta fend home to his own family at the end of the voyage: a paultry theft, at the expence of the health and fraft-bitten limbs of thofe on board. When the reader is informed that fuch has been my paf- fion to vifit foreign climes that I have been no lefs than fifteen voyages, one of them round the world, he will not be furprifed that I fhould with to gratify my curtofity by vifiting the frozen regions, even though I knew fomething of the inconveniencies before defcribed, ta which thofe whe undertake the voyage are often expofed. My bufinefs was to guard againft them as well as poffible, by proper inquiries refpecting the character and difpofition of the mafter, and T fucceeded to my with in two voyages-to thefe parts: the firft was in the Sea Horfe in the year 1779, which yielded mg 2 much Account of a Voyage to Spit/bergen. 14t much fatisfaGtion; but I was more completely gratified by the fecond, which is the one I mean to defcribe. I engaged myfelf as furgeon on board the Rifing Sun, William Souter mafter, a well-appointed ftout thip of 400 tons burthen, in the employ of Mr. William Ward. The veffel carried about go men, and had 20 nine-pounders mounted on the main-deck, with nine whale-boats, fome of them hung in the tackles over the fides, and others ftowed and lafhed on the deck. We failed from London in the latter end of March 1780, and, as is ufual with Greenlandmen, called at the town of Larwick, the capital of the Shetland ifles, where we found a moft hofpitable reception. A Mr. Innes, the moft opu- jent inhabitant of that country, kept an open table for every matter of a vellel and his furgeon; and no language can con- vey a proper idea of the kind and difinterefted manner in which he received and entertained his guefts. We lay there fourteen days wind bound. The country has a bleak barren appearance, the furface being generally rocky, or covered with turf, which is the fuel employed there; but the bene- yolence and hofpitality of the more opulent, and the decency, fobriéty, and good conduct of all the inhabitants, even thofe of the loweft clafs, more than compenfate for the barren- nefs of the foil. ' Provifions of every kind, the finer vegetables and fruit ex- cepted, are very abundant here, and extremely reafonable. The price of a good fowl was threepence, of adozen of new- _ faid eggs one penny; and as much excellent fith, cod, had- dock, halibut, mackerel, &c. could be bought for one fhilling, as would coft at leaft ten pounds at Billingfgate, or as ufed to dine our whole thip’s company and the cabin. Potatoes, turnips, &c. are not more common there than peaches and apricots in England. Wheat flour is alfo a rare article, but the inhabitants in general prefer bread made of oatmeal. The town of Larwick confifts of about 200 houfes, of one, er at moft of two ftories, which form a narrow crooked lan 9 on « 142 _ Account of a Voyage to Spitfbergen. on the fea fide, badly paved with flat ftones. All the houfes are built of quarry ftone: thofe of the rich are roomy, flrong, convenient, and well furnifhed ; thofe of the poor are fmall, and very fmoky, for want of a proper arrangement of the chimneys. . Though the placé lies in 60° north latitude, the winters are not fevere ; they are, however, wet and ftormy. © The harbour is very capacious and fafe, and the anchoring ground good. About twenty or more Englifh Greenlandmen were Tying here at anchor, and feveral Dutch herring-buffes. Having filled our empty water-cafks, and laid in a flock of fowls, eggs, geneva, &c., we took leave of our kind friends on - fhore, and, the wind being foutherly, hove up our anchor and fet fail for the ice. As we ‘advanced to the northward the night hecame fhorter till we came near North Cape in lat. 71° 10’, when we had no night at all. We were overtaken in that latitude by a moft tremendous gale of wind from the north-eaft, which lafted three days and nights. Our fhip lay more than once on her beam-ends, and every one on board thought fhe could never right again; but providentially we weathered the gale. A ftorm in thofe high latitudes is fo intenfely cold, when it blows from the north or north-eaft, that it is impofhble to look in the wind’s eye, as the cold is fuch as literally to tear the ikin off the face. In about 76° northern latitude we meet with ice floating in fmall round cakes, by the failors called pancakes: you fail through this ice in perfe¢tly {mooth water; which, from being of a green colour in the North Sea, blue to the north- ward of Shetland and Ferro, grows gradually of a darker colour, and looks now of a deep black dye. We failed fe-’ 1 veral days through thofe floating ice-cakes. When ina ftill _ higher latitude, an open black-looking water re-appears ; and when you reach about 77° or 78 you pafs through darge maffes of floating ice 20 or 30 fathom thick, and fome of them five or fix times bigger than your own yeflel. Great — 6 ; care Account of a Voyage to Spit/bergen. 143 . ware is taken to avoid firiking againft thofe maffes, which fometimes are fo clofe that there remains only a narrow ~ channel for the fhip to fail through, I have feen this con- tinue for 24 hours or longer. When this is the cafe, the commander ftands in the main or fore-top, and fometimes _ higher, and calls down to the men at the wheel how to fteer. This navigation is attended with great danger, as the ice projects under water fometimes two or three fathoms. After navigating through thofe floating mafles, we faw the land of Spit(bergen eaft from us, It is feen at an almoft in- credible diftance, fometimes at thirty leagues; a proof of its ; immenfe height. It generally appears amazingly bright, of the colour of the full moon; while the fky above it looks white and cold, In 79° and 80° you are prevented from going further to _ the northward by a folid continent of ice, or a colleétion of ice-fields, as they are called; fome of which are many miles im extent. You make the fhip faft there with an ice anchor, and look out for whales, having two or three boats on the watch conftantly. _ No fhip could ever poffibly navigate through the huge -matles of i ice, which muft neceflarily be paffed before it ean reach this high latitude, but for a circumftance which “would on firft view be little expeéted—The fea there is always as perfectly fmooth as the River Thames: the irre- ‘gularly difpofed maffes of ice prevent the water from ever acquiring, by the ables of the Pong thofe regular undu- b: PAs foon as we got into fmooth water, perhaps forty or fifi ie from the yt the fevere climate and inten te ice 344 Account of a Voyage to Spitfhergen. ice diffolved and kept dropping till a return of colder wéae . ther. Among the fields of ice, but more fo in the harbours, it is confiderably warmer than on the paflage near North Cape. In the month of June we killed feven large whale fifh, and went with them into Magdalena Bay, to cut the blubber up into fmall bits to fill the blubber-butts; which bufinefs is called making off. As the killing of the whales has been very well defcribed by Zorgdrager and others, I need not defcribe it. When you approach a harbour on the coaft of Spitfber- gen, and, judging by the eye, expect to get in and come to anchor in three or four hours time, you are perhaps not lefs than ten or twelve leagues from it. This deception is owing to the immenfe heights of the rocky mountains, covered with fnow, and bordered with ice towards the fea-fide, which make very large harbours appear like {mall bafons, and the largeft fhips, when clofe under them, like a boat on the Thames. Magdalena Bay, in 79° north, is capacious enough to hold the whole Britifh navy; but, on account of the immenfe mountains which furround it, appears like a very fmall inlet. - We came to anchor in this bay, where we lay three weeks, While the people were making off, the mafters, furgeons, &c. of the different veffels then there vifited each other, and diverted themfelve$’ in the beft way they were able. Such vifits laft fometimes 24 hours, for there is no night to inter- rupt the entertainment. The firft thing that ftrikes a curious mind here is that fo- _ Jemn filence which reigns around; fometimes interrupted with a noife, like thunder heard at a diftance, occafioned by huge fragments of ice and rocks rolling down from the im- menfe fteeps into the fea. I attempted to afcend one of thefe mountains called Roche Hill. I got up about half way, which took feyeral hours hard labour. At that height I found the rocks covered with birds eggs of different fizes. There — 3 | E Account of a Voyage to Spitfbergen. 145 There are feveral rivulets and waterfalls of excellent water fupplied by the melting of the fnow. I met frequently with feurvy-grafs, wild celery, endive, water-creffes, and a few other plants and flowers; though the general vegetation which covers the rocks confifts in various kinds of moffes Z and ferns. There are white bears of an enormous fize, white foxes, deer, and elks; and above twenty different forts of water and land birds; fuch as, wild geefe, wild ducks, fea- f parrots, roches, fea-gulls, mallemooks as the failors call them, whofe quills make the beft drawing pens I ever met with, wild pigeons, the white duck with a beautiful fcarlet head and yellow legs, and the fnow-bird,. whofe note is as 4 -pleafing as that of the bullfinch or nightingale. j This feafon was the fineft ever remembered in thofe high : latitudes, and we had almoft conftant fine weather. As we 5: had room yet on board, and the feafon was not too far ad- Es vanced, in hopes of killing a fith or two more, we left Mag- i dalena Bay and fteered north. When we arrived in 80° we found a perfectly clear ocean free from ice, but faw no : whales. 2 We continued pufhing to the northward with fine foutherly i breezes and moft beautiful weather, and could, with a good + telefcope, difcover no ice to the northward, from the main- top-maft head, but a folid continent of ice eaft and weft; fo = that we were in a kind of channel of perhaps three or four oe leagues wide. We kept puthing on, the captain and I jok- ing together about paffing through the pole. _ Both Captain Souter and myfelf found ourfelves at length fome minutes north of 82°, where perhaps no man before us had ever been, nor fince. The high fnowy mountains of North Bank, or North Foreland, appeared very luminous, and bore fouth on the compafs. We had a ftrong: inclination to pufh ftill further north ; but the danger of the eaft and weft ice, now to the fouthward of us as well as to the northward, moving and locking us r in, in which cafe we muft have been befet and inevitably "i Vou. IV, L | lott, i. 146 Account of a Voyage to Spit/bergen, loft, created a prudent fear, and induced the mafter to put about fhip for North Foreland. The wind fhifted at the fame time to the northward,’ and in a couple of days we éame to anchor on North Bank, called Smeerenburg’s Har- bour. We faw now plenty of fin-fifh or finners, white whales, and unicorns; which is a fign that the feafon is over for killing the black whale, which then retires to the north- ward. As all thefe animals are well known and defcribed, I forbear faying any thing refpecting them. One of our men having been at the habitation of the Ruf- fians in North Bank the year before, and affuring us that he ¢ould find the way to their hut, Captain Souter, a man of an inquifitive mind, propofed to me to pay them a vifit. We took ten or twelve men with us, a compafs, a few bottles of wine, bread, cheefe, &c., and fome good trade-knives, with a fmall keg of gunpowder, to make a prefent of to the Ruf- fians. We landed at the bottom of the harbour to the eaftward, where we found a large valley, feveral miles in breadth, fur- rounded with immenfe high mountains, moftly covered with fnow; but as the fun had melted a part, the brown and black rock appeared, and rivulets of clear water ran down, forming little waterfalls. The ground was turf and clay, and not bad to walk on: we had feveral fmall rivulets to crofs, of two or three feet wide, but very fhallow; near them we found feurvy-grafs, waiter-creffes, endive, wild celery, and a few fmall flowers, and faw a number of land birds ftying up at our approach. We crofled a piece of ground where the Dutch had formerly buried their dead: three or four of the coffins were open, with human fkeletons lying in them. Some infcriptions on boards, of which above twenty were erected over the graves, had the years 1630, 1640, &c. affixed to them. We _alfo faw the ruins of fome brickwork, which had been a fur- nace, as the Dutch ufed to boil their oil here in the laft cen- tury, and for that reafon called it Smecrenburg’s Haven, or ) the - Account of a Voyage to Spit/bergen. 147 the Harbour of the Fat Borough. We had above fix miles to walk to the northward, and were very much fatigued on account of the unevennefs of the ground and the heat, when we difcovered the hut of the Ruffians at a diftance. They perceived our approach, and fent two or three people to meet and welcome us. The common men made a ftrange appearance; they " looked very much like fome Jews in Rag Fair or Rofemary- . Lane: they wore long beards, fur caps on their heads, brown fheep-fkin jackets with the wool outfide, boots, and long knives at their fides by way of hangers. When we arrived at the hut, we were prefented to the caravelfk or commander, and to the furgeon, who both received us very politely, and invited us into the houfe, where we fat down to reft and re- frefh ourfelves. Our people were introduced to their people in an outer room, ahd were entertained with meat and brandy. It happened fortunately that the furgeon was a Ger- man, a native of Berlin, of the name of Iderich Pochenthal, confequently I could converfe with him ; and we both acted as interpreters between his and our commander. Captain Souter began with offering to the Ruffian com- mander, (who was alfo dreffed in furs, only of a finer fort, and wore his beard and whifkers like the common men,) the keg of gunpowder and half a dozen of good table knives and forks: the Ruffian captain accepted them with a great deal of joy, and made us a prefent in return, confifting of | half a dozen of white fox fkins, two brown loaves of rye bread, fix {moked rein-deer tongues, and two rib-pieces of fmoked deer, for which we kindly thanked him. They turned out to be moft excellent eating, and of a finer flavour than any Englith fmoked tongues, or hung beef. We placed our wine on the table, our bread and cheefe, and the Ruffian captain ordered boiled fmoked rein-deer tongues, new rye bread, and good brandy and water to be brought in. We all made a hearty, fociable meal; the tongues, and the rye bread, which was new and favory, were L2 a rarity 148 Account of a Voyage to Spit/bergen. a rarity tous; the Ruffian officers relifhed our Chefhire cheefe and fhip’s bifeuit as a very high treat. We drank the Em- prefs of Ruffia’s and King George’s health. The Ruffian commander was an elderly man, of very agreeable manners ; the furgeon extremely fo, and very intelligent. The hut confifted of two large rooms, each about 30 feet {quare, but fo low that I touched the ceiling with my fur cap. In the middle of the front-room was a eireular erec- tion of brick-work, which ferved as an oven to bake their bread, and bake or boil their meat, and at the fame time performed the office of a ftove to warm the room. The fuel employed was wood, which drives on fhore plentifully in whole trees {tripped of their branches. A chimney carried the fmoke out of the roof of the hut; but when they wifhed it, they could, by means of a flue, convey the fmoke into the hack room for the purpofe of fmoking and curing their reins: deer flefh and tongues, bears hams, &c. Round three fides. of the front room was raifed an elevated place of about three: feet wide, covered with white bear fkins, which ferved for bedfteads. The captain’s bed-clothes. were made of white fox fkins fewed together; the fungeon’s was the fame: the boatfwain, cook, carpenter, and the men, had fheep-fkins.. The walls infide. the room were very fmooth, and white- wafhed; and the ceiling was made of ftout, deal-boards,, plained fmooth, and white-wathed. The rooms had a fufficient number of fmall glafs windows,. of about two fect fquare, to afford light: the floor was. hard clay, perfectly fmooth: the whole hut was nearly 60 feet in length, and 34 wide outfide ;, and was conftruéted of heavy beams cut fquare, of about twelve inches thick, laid, horizontally one upon the other, joined at the four corners by a kind of doye-tailing, caulked with dry mofs, and payed over with tar and pitch, fo that not a breath of air can pene-~ trate; the roof confifted of thin ribs laid acrofs the beam- walls, and three-inch deal nailed over them, fo that you could walk on the top of the houfe: the roof was caulked and tarred, ae ial F 7 Account of a Voyage to Spitjbergen. 149, tarred, and perfeétly tight. This is the manner of building houfes in the country in Ruffia, particularly about Archangel. The furgeon gave me the following account of this Ruffian colony in Smeerenburg’s Harbour: Some aflociated merchants at Archangel fit out a crabbla, or veliel, every year, of about 100 tons, with a commander, mate, furgeon, boatfwain, carpenter, cook, and about fifteen hands, well provided with mufkets, powder and flot, good Jarge knives, and all kinds of utenfils for killing whales, unicorns, rein-deer, bears, and foxes, With a fufficient ftock of rye-flour, brandy, clothing, fnow thoes, deal boards, carpenters tools, &c. this veffel fails every year in the month of May from Archangel, goes round the North Cape of Nerway, and arrives in June or July at Smeerenburg’s Harbour, where the new colony is left on fhore. The vetlel ftays two or three weeks in the har- bour to refit, and carries the ok! colony with their cargo (confifting of whales’ blubber, blades or fo called whalebone, white bear {kins, white fox fkins, eiderdown and feathers, unicorns’ trunks, which is en ivory that never turns yellow, and fmoked rein-deers’ tongues,) home to Archangel. The colonifts have no wages, but receive thoufandth fhares for what they bring home: the captain has fifty fhares, the mate and furgeon thirty each; the carpenter, boatfwain, and cook, ten each; and each common man or boy has one fhare. The furgeon told me that the captain had above i900 rubles due to him, and he himfelf about 600, and each common man perhaps 50 or 60: that when they returned fafe home, the common men would be able to live a whole year upon their money, and the officers much longer, as the neceffaries of life were yery cheap at Archangel; and for the Company it had hitherto anfwered extremely well. _ He told me this was his fecond trip, fo well had it an- fwered his expectations. During the fo called long nights,” faid he, *¢ it feldom or never is fo dark that you cannot fee before you, nor is it fo dreadfully cold as it is at Peterfburg L3 every 150 Account of a Voyage to Spit/bergen. every winter, When a fnow ftorm happens, we cannot go out of the houfe; but when it is ferene, and no wind, it is not too cold to go out and walk many miles. With the moonlight, the uncommon brilliancy of the ftars in thefe high latitudes, and the reflection of the northern lights, or aurora borealis, we have fo much light that we can fee to read a book or to write. “ In winter time the black whales come into the harbous and play clofe within fhore, where we kill now and then one with harpoons fired out of a fwivel. We kill white bears, foxes, rein-deer, and birds, as many as we can before the night-feafon, which commences in September, when all the Jand animals Jeave us and walk over the ice into Nova Zem- bla and Siberia: the land birds leave us in the fame manner, Unicorns we alfo kill in the harbour, for the fake of their ivory trunks, which are afterwards fent to Germany and France.” The furgeon and I had a race on fnow fhoes, which are a kind of tkates, of about two feet in length, for fkating over the fnow and ice. As I was in former years a+good fkater, I could ufe them as well as he did. We ran fix or feven miles with them in an hour without fatiguing ourfelves: they have no irons. Before we left our Ruffian hoft, he informed us, that a few weeks before they had, coming home from a {hooting party, found an Englifh captain and nine or ten men overhauling their property in the hut, The captain, finding that his cheft had been broke open, and that his rubles were dimi- nifhed confiderably, reproached the Englifh commander with the robbery, and a battle enfued. ‘ The Englith fired upon us,”” faid the furgeon, who aéted all along as interpreter, ** and killed one of our men on the fpot. We returned the fire and wounded fome of his men, and caufed them to retreat precipitately. When the Englifh were gone, our captain counted his rubles, and found that there were 600 mifling.”* He intended to fend a ftatement of the affair to the Ruffian government, After Account of a Voyage to Spit/bergen. 151 After having ftaid above twelve hours with the Ruffians, highly entertained, we invited them to come to fee us on board and took our leave, returning the fame way by the compafs, and arrived fafe on board, after having been abfent almoft eighteen hours. We now prepared for the voyage home; and, after having filled our empty cafks with good water from the fhore, and made a clear fhip, we fet fail with a fine north-eafterly breeze in the middle of July 1780. We failed again through a great quantity of floating ice, and, our fhip being a good failer, paffed feveral full fhips bound homewards. - The firft pleafing change we experienced was to have fome night, and to be obliged to light a candle in the cabin. O what a luxury !—When you have no darknefs for a confider- able time (during May, June, and July), light becomes te- dious at laft; and the firft time you fee a candle burning in the cabin, and a dark night, the pleafure is indefcribable. Before we came into this more fouthern latitude, I ufed to obferve the fetting of the fun, refting, as it were, on the ho- rizon, appearing of a very large fize, furrounded with moft beautiful and glorious colours of various tints, and then the rifing of it fhortly after in full majefty. Language cannot. convey an idea of the fcene. We came to anchor at Larwick towards the end of July, and were received in the kindeft manner by Mr. Innes and all our friends in the place. After three weeks ftay we took leave of our Shetland friends, and failed in company with a number of full fhips . for England. When we came on the coaft of Northumber- land and Yorkfhire, the breeze and weather being favour- able, we were delighted with the fmell of the hay from the fhore, and the fight of the pretty little towns and villages. built on the fea-fide, and refrethed with excellent frefh cod and haddock, which the Yorkthire cobles (a kind of fithing boats) bring on board; in return for which they prefer taking a piece of beef or pork to money: they bring fome- L4 times 152 An Attempt to arrange the times eggs, potatoes, &c. We had an uncommonly plea- fant voyage home, and conftant fine weather, accompanied with northerly breezes. We arrived about the latter end of Auguft fafe in Green- land Dock, after having been out five months. Captain Souter kept an excellent table in the cabin, and 4 conftant fire in the ftove: his ftudy was to make every perfon on board comfortable. In the fifteen voyages I have been to fea, I have only twice had the good fortune to fail with men of equal worth ; Mr. Charles Patterfon of the Sea Horfe, and Mr. William Alder, now a Lieutenant in the Britith Navy. VI. An Attempt to arrange the Cryflals of Oxidated Tin Ore, according to their fuppofed Struéture. By Mr. WiL- LIAM Day; Leicefler Place. Communicated by the Author. Tur cryftallifations of oxidated tin ore are defcribed by . Romé de I’Ifle, in his Criftallography, to be of the oétaedral form and its modifications; the o¢taedra having ifofceles triangular faces, inclined at an angle of 45° to the bafe of each pyramid; fo that the junction of their bafes and apices are right angles. In the following arrangement the oéta- edron is confidered as the primitive form, and the modifica- tions as being produced by an accumulation, on its faces, of Jamin compofed of fimilar minute moleculz, experiencing different laws of decrement on their fides or angles, or on both. Thefe laws of decrement are marked with the fiens in- vented by Hauy, of which an account has been given in the Phil. Mag. Vol. II. p. 398. The greater part of thefe forms having been very accurately defcribed by Del’Ifle, all that is now attempted is an application of Hauy’s fyftem to the ar- rangement of this part of a private cabinet of Englifh mine- rals; nor would it have been made public but for the re- peated folicitations of feveral friends. In i = al Cryftals of Oxidated Tin Ore. 153 In the annexed drawing (fee plate ITI.) all the plans, and alfo the figures marked 12, 14, and 1c, are geometrical: the others are drawings from models, and in perfpective as they appear to the eye; but ail of them placed in the fame rela- tive fituation to the nucleus, fig. 1., on which they are fup- pofed to be formed. Mathematical correétnefs is not at- tempted, nor is it neceffary. The prifms are fhewn with the pyramid on one end only; not on both, as in Del’Ifle’s plates. Fig. 1, a perfpective view of the primitive o¢ctaedron of oxi- dated tin ore. Ia, a front geometrical clevation, with the quantity of the angles marked upon them. 1 4, an angular geometrical elevation, alfo with the quantity of the angles marked upon them. 1c, one of the faces of the oftaedron, fubdivided to thew the fuppofed arrangement of the primi tive molecule that form one lamina. The dark triangles re- prefent the fpaces they occupy refpectively, and the diffe. rence of {hading, the progrefs of diminution by a fubtrae~ tion of one range of moleculz on the edges of the faces, ace cording to the third law of decrement. The fuperior angle A of this face is 70°, the two inferior angles E, E, 55° each. The letters on the three geometrical figures mark the fame fituations on all of them, and are thofe employed by Hauy to indicate the laws of decrement, _ As Hany’s /y/fem has been given in the Firft Volume of the Philofophical Magazine, and his /igns in the Second, little more is required here but to give the fign to which the figures belong. Firft Law of Decrement D. To this law belong fig. 2, 3, and 4. Fig. 2a, without the dotted lines, would reprefent a plan of fig. 2. That portion of fig. 2 a, included between the dotted lines 54, bd, reprefents a plan of fig. 3. The plan of fig. 4 is evident from the figure. Second Law of Decrement \E«, Fig. 5 belongs to this law: fig. 2 a, the angles being taken off at the dotted lines, reprefents a plan of it. Fig. 6 isa ” combination 154. An Attempt to arrange the combination of this law with another not yet determined, making the prifm fixteen-fided: fig. 6 @ is the plan. Third Law of Decrement B: D 1B. Fig. 7 fhews it incomplete. The plan is fhewn, fig. 22 a, including the dotted lines, Fig. 8, the completion of this law: 8a is the plan. Fig. 22 is an irregular formation, by this law taking place unequally: 22, (without the portion expreffed by the dotted lines,) is the plan, The plans of two other unequal accumulations, which difguife the pyramid, are fhewn fig.7a, 75, Fig. 21, the fameas fig. 8, become euneiform: 21 a, the plan. Fourth Law of Decrement A. < Fig. g fhews the combination with the firft law: fig. ro, the fame with the third law, incomplete: fig. 11, the laft com- pleted: fig. 12, the combination with the firft and fecond laws: this, and the combination with the firft law only, are im general peculiar to Bohemian and Saxon ores; the Englifh ‘eres exhibit but few examples of them. Ihave an Englith eryftal fimilar to fig. q, and it is the only one I have feen, Fig. 13, the combination with the fecond and third law: fir. 13. is the plan. Fifth Law of Decrement *E* D. ’ I - Fig. 14, the firft indication of this law, in combination ( with the third law, incomplete. Fig. 15, this law farther extended in the fame combination: 15 a, the plan. Fig. 16, ; a further extenfion, but fill incomplete: fig. 16 a, the plan. Fig. 17, the completion of this decrement: fig. 172, the plan, Fig. 18, the combination of this law, when arrived at the ftave fhewn in fig, 16, with the third law. Compare fig. 15 — and 18. Fig. 19 and 20 are the fame as fig. 16, with fome y irrecularity in the formation, ,, Thefe five laws of decrement embrace all the varieties of — facets I have yet obferved (except thofe mentioned when — i {peaking of fig. 6); and by combination, in different flages — Z of —— Cryflals of Oxidated Tin Ore. 155 of each refpectively, produce a great variety of forms, while other varieties arife from difference in colour and tranfpa- rency to which all thefe cryftallifations are fubject. The macles of De I’Ifle, which Hauy has called emt. | trope, or half-turned, may be added as a fupplementary clafs. Of the term macle, De I’Ifle gives this explanation: s* When in any cryftal whatever one or more re-entering or internal angles are obferved, we may conclude that it is net a fimple cryfial, but a group of two or more; or even __. tivo turned’or reverfed moieties of the fame cryftal.” De V'Ifle was indebted to a Mr. Lermina for determining the dire&tion of the fection which produced the hemitrope cryf- tals of tin, which he has fhewn to be parallel to two oppotite edges of the oftaedron. Imagine the primitive o¢taedron to ’ be divided into halves by a plane paffing diagonally through it, from the centre B, fig. 24, of one of the edges of the fu- perior pyramid, to the centre B of that edge of the inferior pyramid which is diagonally oppofite; the plane will pafs through two oppofite angles FE of the bafe, dividing on each pyramid two adjoining faces into four f{calene triangles, and leaving two adjoining faces perfect, but reverfed on one py- ramid in refpeét to the other. The plane FBEB* of this feétion is a rhomb of 60° and 120°. The prifmatic cryftals appear to be as fufceptible of that fpecies of accumulation which produces the hemitrope as the _ oétaedron, and the fetion is always parallel to the one deter- mined above. If the prifm is fhort, and terminated by two pyramids, the fection will pafs through the prifm into bath pyramids, and be irregularly oftagon; but if the prifm is long enough to permit the fection to pafs through it without encroaching on the pyramids, it will be a rhomb of 70° and 110°; the fame as the fetion of the primitive otaedron, per- _ pendicular from the apex, and diagonally acrofs the bafe. I have fome cryftals which are produced by a double fec- tion, and both ends turned on the middle part; others which appear to be only portions taken off the angles at the junc- tions 156 An Attempt to arrange the tions of the pyramids to the prifm, and reverfed together with- out the intermediate part. In faét, the varieties appear to be almoft innumerable. tal After I had made the above arrangement, I receivett the 32d Number of the Journal des Mines, from which I beg leave to fubjoin the following extracts : ‘© The primitive form of the cryftals of oxydated tin ap- peared to me to be that of a cube performing the function of a parallelopipedon; fo that the decrements which preduce the fecondary forms have,’ in regard to the two oppolite faces of the cube, which muft be confidered as the bafes, an aétion different from that which takes place in regard to the other four faces that reprefent the planes of the prifm.” (p. 576.) “* One of the rareft varieties of this kind is that reprefented fic. 7*, and which is the feventh of Romé de Lifle, T. IIT. p- 422. We give it the name of di/ligu> oxyd of tin; that is to fay, with two ranges of facets. It has altogether thirty-fix faces; four of which MM are vertical, and on each fide eight inferior oblique z, #’, and eight fuperior oblique 0,s. If, as ufual, we denote the edges of the hafe of the cubic nucleus by B, and the angles by A, we fhall have, as the indicating fign of this variety, M (A B? B’) B A, in which the intermediary decrement is referred to the facets sy &', the decrement B to the facets s .s, and the decrement A to the facets 0,0. The following is the indication of the principal angles: incidence of M to M go°, of z to z 116° 20’, of = to x’ 158° 30, of s to s 120°, of otos 150°. Quantity of the angle 7 118° 4/.” (Suite de [Extrait du Traité de Mineralogie de C. Hauy, p. 578.) . _ From the preceding extracts it appears that Hauy has fup- poled the cube to be the nucleus or primitive form of the oxidated tin cryfials. I have again carefully examined the cryftals in my own colleGtion, and, according to the indi- * Pig. 23 is a tracing from Hany’s fig. 7, referred to here, and is the ’ fame crpftal as reprefented fig. 18. : By: cauions ie yee Cryftals of Owidated Tin Ore. 157 cations obferyed on them, from which I have formed my arrangement agreeably to the law laid down by Hany him- felf, (fee Phil. Mag. Vol. I. p. 292.) I fee no reafon at prefent why I fhould alter it. The cryftals of oxidated tin are in general fo hard and brittle that I have not been able to feparate the lamine ; and there is nothing to enide the obferver but the direétion of the ftriz on the fecondary facets. Now the faces, which are parallel to the faces of the oftaedron before mentioned, are always very brilliant ; but thofe which are on a plane with the! edges are ftriated parallel to thoie edges, particularly thofe cryfials which fhew the interme- diate {tages of the third law. If the nucleus were a cube, and the laminz accumulated on it, to form the fecondary cryftals, fhewed their diretion by ftriz on the new facets, thofe ftriz would be in a direction quite contrary to what are fhewn on thefe cryftals: inftead of going the length of the new facets parallel to the edges of the odtaedron, they would crofs the facets perpendicularly to their prefent direc- tion, and it would be impoffible for the cryftal fig. 7 to take the form of fig. 8. In my collection there is a group of opaque black cryftals, fhewing all the variations from the primitive prifmatic cryftal fig. 2, to the completion of the third law of decrement fig. 8. In all of them the direction of the ftrize is very evident. The Saxon and Bohemian ores of tin are moft common in the cabinets of France: the ery{ftals are larger, but do not prefent the varieties of forms that Englifh ores do; being moftly confined to the oftaedron and its hemitrope, and thofe variations of the fourth law which approach the cube. Had Hauy feen a greater number of the varieties of the Englith tin ores, I think he would, for the primitive form, have had recourfe to the octaedron, which, by a very fimple law of decrement, produces the cube ant its varieties that occur in the tin cryftallifations. To thefe obferyations may be added De I’Ifle’s deloription of the fame cryftal that [lauy has defcribed (above) , which Mf I find 158 An Attempt to arrange the T find to agree fo well with what I have obferved in naturé, that I am inclined to fuppofe Hauy’s meafures of the angles are given from calculation, affuming the cube as the nucleus, and not from meafurement on the cryftal. De l’Ifle’s de- _ {cription is as follows : ? “Tt is a blackith kind of tin ore, in fmall folitary cryftals five or fix lines in length, and at moft three in breadth. In the variety in queftion, one of the extremities of the retan- gular tetraedral prifm firft prefents an o€taedral pyramid, the planes of which forming with the prifm an angle of 155% are irregular pentagons, having one of their angles of 60°, two of 120°, one of 110°, and the moft obtufe of 130°. Thefe pentagons form with each other angles of 110° and. 160°. The pyramidal form thence refulting is itfelf termi- -nated by a tetraedral fummit with trapezoidal planes join- ing at right angles, as is obferved in the ifofceles triangles of the third variety: but this fummit becomes o&taedral by the flight truncature of its edges, from which refult four linear hexagons that form by their contact at the fummit of the pyramid obtufe angles of 110°. The planes of the prifm, had it not been broken, would be regular hexagons, and the whole cryftal would then have thirty-fix facets.” De PI/le’s Cryftallographie, Tom. Ill. p. 423. Having faid fo much refpeéting the external form, a few remarks concerning the chemical analyfis of tin ores cannot be mifplaced in a paper hike the prefent. On this part of the fubje&, I cannot do better than by quoting from a paper of C. Guyton, formerly and better known here by the name of De Morveau, whofe chemical authority always carries great weight with it. In his paper entitled, Ob/ervations on the Acid of Tin, and an Analyfis of tts Ores, after giving the analyfes of the brown tin ore of Schlackenwald, as pub- lithed by Mr. Klaproth, which he verified himfelf, and found to contain, tin 75, iron o's, filexo-75, and oxygen 23°75 =100; he procecds to give a reafon why the tin cryf- | tals Cryftals of Oxidated Tin Ore. 159 tals are fo infoluble in acids, and combats the idea of Klap- roth, that it arifes from fuperfaturation by oxygen, which is diffipated by fluxing the ore with vegetable alkali. “© I believed I had good reafon,”’ fays he, ‘* to doubt that the complete oxygenation, or (if the term be preferred) the fuperfaturation by oxygen, was the true caufe of its infolu- bility in the muriatic acid; becaufe I could not, at any one inftant of the operation, perceive either the fubftance that ‘fhould take it away, or any of the phenomena that would _ have accompanied its difengagement. That I might with the greater facility obferve all the circumflances, I operated with _ afmall platina crucible over an Argand’s lamp. Fifty-five centigrammes of brown cryftals of tin were reduced to a fine powder, and mixed with fix times as much pot-afh (purified by alcohol, and dried): the mixture was moiftened with a few drops of water, I evaporated it firft to drynefs, and then to a commencement of fufion. After the firft treatment, hot water poured on the mafs diffolved more than half the mi- neral, which was then firft precipitated from it by muriatic acid, and afterwards rediffolved by it with the greateft faci- lity; and the precipitate of the metallic oxyde, reproduced by adding carbona tof pat-ath, was found, as ftated by Klap- roth, conip'etely foluble again by the fame acid. After hav- ing myfelf witneffed this fact, my firft doubt on the dire& caufe of ihe infolubility of this ore was rather ftrengthened than removed. It cannot be faid that the excefs of oxygen efeaped during the fufion with the pot-ath; for the metal ‘could not form a foluble combination with alkali, unlefs it was oxidated in the higheft degree; or, more properly, in the fate of an acid, fo as that the folution filtered from the “efidue fhould be a true ftannate, or (if the term be pre-~ ferred) fiannite of tin *. _ © Now, if we are obliged to admit that all the oxygen of the ore is again found in the alkaline folution, it cannot be the lofs of a part of that principle that renders the metal * The author muft have written Stannite of pot~afh. D. more 160 - Chemical Analyfis of Tin Ores. more foluble in the acid, for it is ftill found in the fame flate of faturation: befides, it does not exhibit any figns of the oxygenated muriatic acid gas; and in this cafe it is difficult to conceive why there fhould not rather be a difengagement of this gas at the time of digeftion of the acid on the ore, as happens with the oxydes of manganefe and lead. *< To eftablifh this point of theory on a decifive experi- ment, I diffolved fix grammes of tin in nitrous acid, which I evaporated feveral times to drynefs, adding each time freth acid. I think it cannot be doubted that in this ftate the tin had taken all the oxygen it was capable of fixing; yet the mafs of white oxyd, wafhed till the water that came from it did not in the leaft alter vegetable colours, was readily dif- folved in muriatic acid. What then is the caufe of the in- foiubility of the ore, which alfo is nothing but tin and oxy- gen, containing hardly 001 of extraneous matter? The caufe can only be found in the fate of aggregation of the latter. This affertion ought not to excite furprife, for hitherto fuffi- cient account has not been taken of this power. If com- binations are the refult of affinity or eleétive attraction, this attraction itfelf is nothing but a power which may be ren- dered ineffeCtual by the fum of the forces which counteract it. Thefe truths furely will not be denied: by Mr. Klap- | roth, who has rendered them fo palpable, by fhewing us that — the ruby, the fapphire, the adamantine fpar, the elements of which were naturally eafily foluble, refifted the ordinary ~ means of analyfis cee by the ftate of the aggregation of © their integral parts.” De I’Ifle, whofe fecond edition was publfhed in 1783, con=— | jeCtured what Guyton here advances from experiment. His” words are as follow :—‘ I cannot agree with Mr. Reena , that there is no mineralizing iibaariee 3 in the cryftals of tin, — becaufe, in default of fulphur or arfenic, we ought at leaft to _ find the acid principle, by the aid of which the metallic earth — of tin takes a con{tant and determinate cryftalline form.” _ P VII. ee ae VIi. Experiments refpecting the Effeéts of Quickfilver on Vegetable Life. By Von Dzimann, Paats Van TrostwyYk and LAUWERENBURGH*, Pt xpen. I, A plant of the fmall garden bean, which had grown in the open fields, was placed in water clofe to a flafk filled with quickfilver one inch in diameter, and the water was covered by a bell twelve inches in height and fix in diameter. . II. A plant of curled mint, the root of which ftood in water, was placed with quickfilver under a bell eight inches in height and four and 2 half ia diameter. . III, The firft experiment was repeated, with this varia- tion; that the bell, inftead of ftanding over water, was placed on a difh, and fupported by pieces of cork. IV. The fame experiment as the fecond, with this diffe- rence; that pieces of leaf gold were fufpended in the bell. V. A flafk filled with quickfilver was placéd clofe to fome young plants of the /pirea falicifolia, which ftill adhered to the parent root, and the whole was covered with a bell. VI. The fecond experiment was repeated, and a little ful. phur was applied to the interior fides of the beil. * VII. The fecond experiment again repeated, with this dif. ference; that the quickfilver was covered with a little water. Vill. A plant of the curled mint was placed‘in a bafon of water with a little quickfilver, in fuch a manner that the roots were in contaét with the metal. 1X. The roots of a bean plant, which had fhot out through holes.made in the pot in which it had been reared, were placed in a flat difh filled with quickfilver. X. Some beans were planted in earth mixed with quick- ~ filver. XI. A plant of the curled mint was placed in a bafon with water, and red oxyd of mercury prepared with the * From Scherer’s Algemeines Journal der Chemie, Vol. 1. No. 6. Vot. IV. M nitrous * 162° The Effects of Quickfilver on Vegetable Lifes nitrous acid which had been wathed firft with am alcalme: folution. and then with pure water, the roots being immerfed in the oxyd. XII. The fame as the fecond, with this variation; that inftead of quickfilver the oxyd was ufed. XIII. Beans were planted in a mixture of earth and the red oxyd of quickfilver. XIV. The fame planted in earth mixed with the oxyd of lead. XV. Of three plants of the curled mint, one was placed, in the fame manner asin the 11th experiment, in a phial which contained water and the oxyd of manganefe; the fecond in another, containing water and the oxyd of copper; and the third in one containing water and the oxyd of lead. The leaves and ftems in the experiments 1, 2, 3, 4, and 5, were on the third day covered with black fpots; and on the fourth, fifth, and at moft the fixth, had beeome entirely, black. The young tree in the 5th experiment could not hold out the whole fummer, though it ftood connected with the parent plant. “The plants died fo completely that the leaves frequently dropped off, and the ftem funk down the very moment the bell was removed. The plants in the 6th experiment remained without any change, which fhews that fulphur prevents the bad effects of the quickfilver. In the “th experiment the effect of the quickfilver was deftroyed, on account of the water by which it was eoyered. The experiments 8, g, and 10, prove that the quick&lver, when mixed with earth or water, or when it ftands in contaét, with the roots of plants, is im no manner prejudicial to them. The 11th experiment, which we repeated feyeral times, fhewed us that the oxyd of quickfilver, placed in contaé& with the roots of a plant, is deftruétive to it. This oxyd, however, did not produce the fame effect when it was placed as the metallic quickfilver, near to the plant; as was proved by the 12th experiment, in which the plant did not expe- sience the leat change. -Ia Obfervations on Mewial Bicvay: , ; 163 Tn the 15th experiment the plants were not in the leat ‘aifected by the different oxyds ; which proves that plants, ‘Jike animals, feem capable of beirig accuftomed to things ‘pernicious to them, provided they nee at infancy. The beans planted in earth mixed with the oxyd of quickfilver grew up, but fo weak and ftunted that they could fearcely be known. Thofe, however, which had been planted at the fame time as the former ii a mixture of earth and the oxyd of lead, fhot up as ufual, and éxceéded them in ftrength and weight more than four tinies. In thefe refearches we were at great pains to make fone comparative experiments, and we paeP that the plants in thofe where no quickfily er was employ ed, lived a confider- able time in a ftate of perfect vegetation, Thefe refults we give mercly as facts, w ithout aitempting at prefent to ex- SaRiG them. A contiderable quantity of quickfilver placed in a very confined atmofphere may be equally pernicious to animal exiftence, as we think ourfelves authorifed to infer from feveral experiments, the courfe of which the late feafon of the year obliged us to fufpend, and from which it appears that, in one point of view i things hurtful to animals are hurt= ful alfo to plants. Vil. Obfervations on Animal Eleétricity; being the Subftance of two Letters from A. VOLTA to Profeffor Gren: [Concluded from Page 68. ] Th E very confiderable difference in regard to the quan- tity of effeét in the before-méntioned experiments already fhews, that if the eléétric ftream excited by contact is ftrongeft towards a certain metal, when that metal is placed between a certain fluid on the one fide, and another fluid on the other, there are other fluids which produce a greater effect with another kirid of metals; fo that it will be necef- fury to difeover by experiment the particular arrangement of M 2 conductors’ 164. Polite on Animal EleBricity. conduétors fuited to each metal, in which the fluids or con~ duétors of the fecond clafs muft be difpofed according to their activity. I have paid great attention to this cireum- (tance, and have formed feveral tables, which I fhall publith as foon as J have brought them to perfection. I fhall here, however, only obferve, that in order to clafs, in fome manner, the innumerable different moift conductors. of this kind, I diftinguifh them into aqueous, {piritous, mu- cous, and gelatinous, faccharine, faponaceous, faline, acid, alcaline, and fulphurous (livers of {ulphur) liquids; that E make fubdivifions in the acids down to the beft known fimple mineral acids, (as I find in this refpeé great diffe- rence between the nitrous and the muriatic acids,) compre- hending the principal vegetable acids and the acid of galls; and do the fame in. regard to the faline fluids, according as they are folutions of neutral falts, earthy falts, and particu- larly metallic falts. When it can be determined in what order all thefe kinds. of fluids follow each other, in regard to the power in quef- tion, for the metal A, and another for the metal B, &c., we fhall then be in a condition to determine what place muft be affigned to a great number of other heterogeneous fluids, whether mineral, vegetable, or animal, which belong to fe- veral of the above claffes. In general, the order for the greater part of the metals hitherto obferved is as follows: ft, pure water; 2d, water mixed with clay or chalk, (which fhews.a pretty different effect when the before-mentioned ex- periment is made with two glaffes, a bow of tin or zinc, and 2 properly prepared frog, which has a fafficient degree of vi- tality); 3d, a folution of fugar; 4th, alcohol; 5th, milk 5. 6th, mucilaginous fluids; 7th, animal gelatinous fluids; Sth, wine; oth, vinegar, and other vegetable juices and acids; 1oth, faliva; 11th, mucus of the nofe; 1ath, bloods. 13th, brains; 14th, folution of falt; 15th, foap fuds; 16th,. chalk water; 17th, concentrated mineral acids ; 18th, ftrong: alealine leys;. 19th, alcaline.fluids; 20th, livers of fulphur.. With: Polta on Animal Ele&ricity. | 165 With fome metals there is, however, a confiderable deviation from this order, in regard to livers of fulphur, alcaline fluids, and the nitrous and faline acids. I. As to the metals, which in their pofition between thefe different fluids are more or lefs proper for the electric efile in queftion, I have found in general that tin exceeds all others, and that filver is the worft; except when one of the fluids betwixt which the filver is placed is water, or any other aqueous conductor, and the other liver of fulphur: in this cafe filver far exceeds zinc, and even tin. Iron alfo produces a much greater effe¢t than any other metal, when it is in contaét, on the one fide, with mere water or an aque- ous conduétor, and on the other with the nitrous acid, were - it even only a drop. The excitement occafioned in both cafes is wonderful; fince it exceeds, as I have already re- marked, that produced, according to the ufual method, by means of a double metallic bow, even of different metals, as zine and filver, applied to conduétors of the fecend clafs of the fame kind. It is fufficiently ftrong and powerful to pro- duce convulfive mevement in a half-prepared frog, the bowels of which have not been taken out, when one of the two moift conduétors is a concentrated alcaline folution, and the metal placed between them is zinc, or rather tin. With other metals and other fluids you can feldom produce convulfions in a frog, if it be not perfectly prepared, or at leaft em- bowelled. _ The reader will readily perceive, that when a bow of one and the fame metal touches with both its ends the fame kind of faline water, the fame acid, the fame alecaline fluid, &c. an eleétric ftream will not take place, as happens alfo when it touches on each fide merely water: in that cafe two oppofite actions are oppofed to each other, and keep each other in equilibrium. That thefe contrary powers, however, may be in perfeé& equilibrium, it is neceflary that the fluids applied to both ends of the homogeneous metalline bow be exattly of the fone kind and of the fame ftrength, For this reafon the M3 moft 66 Volta on Animal Eledricity. moft careful attention and a certain dexterity are required ‘in order to enfure fuccefs to the experiment, which I have often performed to the great aftonifhment of the {pectators, . and which any one may repeat as was done by my friend Humboldt. That philofopher has already publifhed fome of the moft {triking and decifive of thefe experiments in his fe- cond letter; and I fhall here g give a more particular aerate of them. ; Having placed a completely or only half-prepared frog as ufual in two glafles of water, take a very clean bow of filver (it will be beft when it has been wafhed with water from the glafles), and immerfe both ends of it at once, or the one after ihe other, in the glaffes, no agitation of the frog will be oc- cafioned. Repeat the experiment, after you have daubed over. one end of the bow with the white of an egg, liquid glue, faliva, mucus, blood, a folution of tartar, or any other fluid or conducting fubftance fufliciently different from pure water. Firft, immer re) the pure end, or that moi{tened merely w ith water, in the water of one of the glafies; and afterwards the other end, daubed over with the above fubftances, in the water of the other g glafs 5 you will then infallibly produce a convulfive movement in the frog, and feveral times in fuc- ceffion, if you draw out*the bow and again immerfe it until nothing more of the above fubftances is left adhering to the metal, or until the metal, with its ends in both the glaffes, touches only pure, or nearly pure, water. Daub both the above fubftaaces uniformly over both ends of the bow, and immerfe them at the fame time in both the glaffes of watery. and no conyulfions will arife, ‘They will often be produced in newly prepared and highly irritable frogs, when the faline fluid, or, in general, the fub{tance with which the two ends of the bow are daubed’ over, is not perfectly the fame, or ~when the fub{tance at the one end is more diluted than at the other, &c. Wath and clean carefully the one end of the bow, daub over the other more or Jefs, and conv ulfions will be — produced as foon as the circle is made coniplete by . the Volta on Animal Eleéricity. 167» the double immerfion of the bow. Clean both ends com- pletely, and no agitation will arife, as in the firft experiment, For comparative experiments of this kind I would recom- mend vifcous fluids or fubftances rather than faline, becaufe the latter are too foon diffolved in the water. It oftimes hap- pens that the convulfions of the frog, when it is completely prepared and highly irritable, take place, though both ends of the metallic bow are daubed over with the fame kind of faline fluid. The caufe of this is, that when one end is im- merfed in the water after the other, (and it may be eafily feen that it is impoffible to do fo in a moment with fufficient accuracy,) the one end of the bow lofes a portien of its faline fubftance fooner than the other, or at leaft the adhering part is more diluted hy the water, fo that the fluid with which both ends have been daubed over is no longer the fame, For thefe experiments I would alfo recommend filver, as a metal whch is lefs liable than others to be attacked and changed by faline and other liquids. Tin, lead, copper, and in particular iron, are more fufceptible of lafting variations ; fo that bows of thefe metals, and of iron above all, retain for a long time the power of producing convulfions in a newly prepared and highly irritable frog, even when both the ends of the bow are immerfed in two glafles of water, although the places of the meta], attacked by any of the faline fluids, have been carefully wafhed and cleaned, A fuperficial alte- ration in the metal is fufficient to produce this change, as may be eafily feen. Thefe variations often thew themfelves to the eye by a yellow blackith {pot, &e. which it is difficult to remove, Ido not herg {peak of lafting variations, that proceed to a greater depth, which can be produced in the end of the metallic bow, and particularly in iron, when its hardnefs is changed; a procefs by which fuch a bow can be rendered capable of producing not only convulfions in frogs, but alfo a particular fenfation on the tongue, and light before the eyes, if both its ends, made perfectly clean, are only brought into contact with pure water, Thefe, and many M4 other 168 Volia on Animal Eleéttricity. other experiments of the like kind, form the chief fubjeé&t of my firft letter to the Abbé Vaffali, Profeffor of Natural Phi- lofophy at Turin, written in the beginning of the year 1794, and afterwards publifhed with the other in Brugnatelli’s. Journal. If filver be lefs expofed to he attacked by faline and other fluids (except by liver of fulphur, which inftantaneoufly renders it black); if it be lefs fufceptible of confiderable and — lafting variations, and has therefore this advantage over other metals, that it is liable to fewer irregularities ; tin, on ac- count of its greater activity, that is, the ftrength of the effects which it produces by being brought into contact with almoft all moift conduétors, as I have already obferved, is to be preferred to filver, and in a certain decree to all other metals.. The experiment 1 have already deicribed with a tin bafon filled with an alcaline fluid, and held in the hands moiftened with water, by which an acid fenfation is excited on the tongue when brought into contaét with the above fluid, is a proof of it; for it would be vain to expe& a like effect from a bafon of lead, iron, or copper, and much more fo from one of filver. With the latter it would be obtained only when it contained liqnid liver of fulphur; and in that cafe the acid tafte would be pretty ftrong. The eleétric fluid is excited alfo with the greateft ftrength and a¢tivity, when the metal is tin, between water and a faline fluid: but it will be excited with ftill greater energy to pro- duce an acid fenfation on the tongue when the tin is between water and an infipid mucilaginous fluid; or when the expe- riment is made with a tin bafon filled with a folution of gum, liquid glue, white of an egg, &c. The other metals, in like circumftances, produce fome effet, but much weaker: filver produces the weakeft, except with liver of fulphur, as I have already obferved. A like experiment, which I made three years ago, and — exhibited to various perfons, not with two different fluids and one metal, as in that above defcribed, but contrariwife, 5 with =e. a ae ie a Volta on Animal Ele@ricity. 16y with two metals of a different kind-and a fluid, is already known. I took a bafon of tin (one of zinc is better), placed it on a filver ftand, and filled it with water. When any of the perfons in company applied the tip of his tongue to the wa- ter, he found it perfectly taftelefs as long as he did not touch the filver ftand; but as foon as he laid hold of the ftand, and - erafped it in his hands well moiftened, he experienced on the tongue a very perceptible and pretty {trong acid tafte. This. experiment will fucceed, though the effect is proportionably weaker, with a chain of feveral perfons who hold each other's hands, after they have been moiftened with water, while the firft applies the tip of his tongue to the water in the bafon, and the laft lays hold with his hands of the filver ftand. If thefe experiments, in regard to the tafte excited on the tongue by the a¢tion of two different metals, are ftriking, the. others, in regard to the tafte excited, modified and changed by one metal between two different fluids, are no lefs fo, and they are alfo newer. They are ftill interefting on this ac- count, that they difcover to us the caufe of that tafte often perceived i in water and other liquids, which is more or lefs confiderable or various when drunk from veffels of metal, and particularly of tin. When the outer extremity of the yeffel is applied to the under lip, rendered moift by the faliva, and the tongue is extended fo as to be in contaét with the water, beer, wine, &c. in the veflcl, or when the tongue is bent as is done in drinking, is there not then a complete cir- cle, and is not the metal between two more or lefs different liquids, that is, between the fuliva of the under lip and the liquor in the cup or veflel? A ftronger or weaker eleétric ftream mutt thereby be occafioned aecording as the fluids are different—a ftream which will not fail in its way to affe& the fenfible organs of the tongue in the faid circle. Befides the two methods already confidered, of producing an clectric current, that is, by means of one or more moift conductors, or conductors of the fecond clafs, placed be- tween two different metals or conductors of the firft clafs ; or 70 © Volta on Animal Eleéiricits. er contrariwife by means of a conduétor of the firft clafy - placed between two of the fecond clafs, alfo different ; there © . is ftill a third method of exciting the electric fluid, though in a degree fo much weaker that it is fcarcely capable of caufing odie ions in a perfectly prepared frog, in which there is Rill a ftrong degree of vitality. This new method confifts in forming the circle of three different conductors, all of the fecond clafs, without the intervention of one of the firft or a metal one, Some think they find in this method a ftrong objection agaim{t my principle, Fig. 20. reprefents this third method compared with the other two*. In the experiments of Profeffor Valli, refpect- ing which fo much noife has been made without any reafon, z reprefents the leg of the frog, and particularly the hard ten- dinous part of the Mujfculus gaflrocnemius; m the rump or the mufeles of the back, or the ifehiatic nerves, to which the faid tendinous parts are applied; and @ the blood, or the vil- cous faponaceous or faline fluid, applied to the point of contact. I have fully deferibed this new method, where no metal is ufed, in my third and fourth letter to Profeffor Vaffali, writs ten in the autumn and winter of the year 1795. I have there fhewn, that thefe new facts, far from altering my ideas and principles, ferve rather to eftablith them; and that they ren~ der more gencral the principle that the conductors, by hete- rogencous contact, that is of two different from each other, become exciters of electricity, and confirm the beautiful law arifing from it, that to produce an electric ftream the cir- ele muft neceffarily be formed of three different conductors. You now fee in what the whole fecret, the whole magic con- fif's; and that it depends not merely on metals, as might have been believed, but on all the different conductors. As Jong as we adhere to thefe principles, it will be eafy to ex- . plain all the before-mentioned experiments without being reduced to the neceffity of having recourfe to any imaginary * Sce Plate I. (in the preceding Number.) principle, Method of manufa€turing Cryftallifed Verdigrife. 19% principle, or any peculiar and active electricity of the organs. By their affiftance you will be enabled to invent new experi- _ ments, and to foretel] the refult of them, as I have feveral times done, and ftill do daily. Ifyou, however, abandon thefe principles, you will find nothing but uncertainty and contradiction, and the whole will be an inexplicable problem, IX. On the Method of manufa&uring Acetat of Copper, Cry- Jtals of Venus, or Cryftallijed Verdigrife. By J. A. Cuar- eA.” Corvsrats of Venus were for a Jong time manufactured in plolland, but at prefent they are manufa¢tured at Mont- pellier, with a degree of perfection which renders them referable to thofe of any other country. The procefs moft generally employed confifts in diffolving verdigrife in vinegar, and evaporating the folution to a pellicle to obtain the cryftals. The vinegar ufed is nothing elfe than four vinaffé ({poilt wine) diftilled. In every manufactory there is therefore an alembic, in which this weak kind of vinegar is continually diftilled, _ This diftilled vinegar is put into a kettle, where it is boil- ed on the verdigrife. After faturation the folution is left to clarify, and then poured into another kettle of copper, where it is eyaporated to a pellicle. Sticks are then immerfed into it, and by means of fome pack-thread aye tied to wooden bars which reft on the edge of the kettle, Thefe flicks are about a foot long, and are {plit crofs-wife nearly two inches at the end, fo that they open into four branches, kept at about the diftance of ap inch from each other by fmall pegs. The eryfials adhere to thefe fticks, and cover them entirely, forming themfelves into groups or clufters, which prefent pp all fides perfect rhombs of a very lively dark blue colour. * From the Annales de Chimie) No. 75. Each 47% Method of manufafuring Each clufter weighs from five to fix pounds, Thefe eryftals, when broken, exhibit on their fraéture a brilliant agreeable green, inclining a little to blue. Three pounds of moift verdigrife are neceffary to make 4 pound of cryftals. The indiflolved refiduum is rejected as ufelefs. Analyfis, however, having proved to me that a great deal of copper in a metallic flate, or weakly oxydated, Gill exifis in it, I difpofed boards in the form of a ftage around the manufactory of C. Durand, and, forming ftrata of about two inches in thicknefs with thefe remains, I foon faw them covered with an efflorefcence of verdigrife. T took care to moiften them from time to time with vinegar, to dif- folve the verdigrife as foon as a fufficiently ftrong efflo- refcence was formed, and they were again difpofed in ftrata _ to proceed as before, in order that I might derive as much advantage from the retiduum as I fhould find convenient. There are fome manufaétories of the cryftals of Venus where the verdigrife is prepared by means of vinegar diftilled according to the method followed at Grenoble, which is well underftood. All the operations tend to the fame end, which is the folution of the copper in the acetous acid ; and the purity of the materials renders it certain that there will be no refiduum or lofs. But however fimple may be the procefs for manufacturing cryftallifed verdigrife, the high price at which it is fold makes it to be much wifhed that it could be ftill rendered more fo. I made fome experiments for that purpofe; but at prefent I fhall confine myfelf to a fhort view of my refults. We mutt fet out from the principle, that the acetous acid does not attack copper in the ftate of a me- tal, and that it cannot effect a folution of it but when re- duced to an oxyd. The quettion then will be to difcover the means of oxydating it in an economical manner. 1ft, I expofed the plates of copper to the gazeous emana- tions of the oxygenated muriatic acid in large glafs receivers, conneéted together in the manner of adoptors, to which I fitted a retort from which the acid was difengaged. 2d, I took J Cryftallifed Verdigrife. 1973 ad, I took a large earthen jar of Provence, well glazed, capable of containing two hundred (French) pints of water, buried it one half ina ftratum of very warm dung in fulk _ decompofition, and having put fome manganefe in the bot- ~~ tom of it, and adapted to it a ftraight glafs tube which reached from the mouth to the bottom, I filled the jar with plates of copper flightly rolled, in order that they might not touch each other but in fome points. J then made to pafs into the bottom of the jar, by means of the tube, the necef- fary quantity of the muriatic acid, and immediately clofed the upper aperture with a luted covering. Two days after thefe plates were entirely crufted over with a greenith oxyd, which detached itfelf in duft and in feales: I feparated of it two pounds ten ounces. This oxyd, lefs lively than that of the common verdigrife, is foluble in vinegar: and this me- ‘thod may then be employed, with fome advantage, to form the acetat of copper; but it cannot fupply the place of the acetous verdigrife either in painting or dyeing. 34, I formed fulphat of copper by pouring, upon plates of copper brought to a red heat mm a crucible, about a third in , weight of pounded fulphur. This fulpbure, exceedingly fri- able, pulverifed and expofed to a pretty violent heat for four or fiye hours, left a grey powder, eafily attacked by the ace- tous acid, That which I digefted at a heat above a gentle temperature, gave, by evaporation, a confiderable quantity of very blue and beautiful cryftals of acetat of copper, and 2 ftratum of true fulphat of copper of a pale blue and w ithout _eryftals. _ 4th, I faturated diftilled acetous acid with oxygenated muriatic acid gas. This acid, digefted cold on the copper, liffolved it in part ; but it formed a beautiful micaceous {caly white, which had no relation with the acetat. Copper ex- ‘ pofed to the vapour of this acetous acid, faturated with oxy- genated muriatic acid gas, becomes covered with very bril- fant {mall cryftals of a bright-blue coloar, fome of whick ate tran{parent and white, Thefe cryftals prefented long = fquare 174 On the true Form of the fquare pyramids, efflorefced in the air, and had none of the chara¢ters of the acetat of copper. | 5th, The acetous acid, dittilled feveral times on the oxyd ef manganefe, attacks copper and diffolves it, but too weakly — and in too fmall quantity for me to recommend this method. . 6th, The acetite of lead poured upon a folution of the ful- phat of copper immediately produces a decompofition from — which there refults fulphat of lead, which precipitates itfelf | in a little time; and acetat of copper, which remains infos ~ lution. By decanting the latter, and evaporating it to a pel- | licle in a copper kettle, you will obtain beautiful cryftals of | Venus. If you wath well the fulphat of lead, and prepare it to be employed in painting, as white lead, this laft procefs. may become very advantageous. Cryftallifed verdigrife is in great requeft for painting and ~ varnifhing, to which it fupplies lively and durable colours, — Chemitts obtain from it by difiillation that acid, the fmell — of which is very penetrating, called radical vinegar and alfoll acetic acid, 5 X. An Attempt to determine the true Form and neceffaty Angles of Weather that ought to be given to Vanes of a” Vertical Windmill as they recede from the Centre, left undetermined by Mr. Smeaton. By Ricuanp Harty GoweE R, in the Sea Service of the Honourable Eaft me Company * ¥ Ox reading Mr. Smeaton’s Experiments to difeover the | proper Conftruétion of Windmill Vanes, read before the without any fixed principle wherewith to give the vanes of vertical windmills their proper degree of weather. v If it were required to determine by calculation the number * Communicated by the Author. Vanes of a Vertical Wi indmill. 173 ] of turns that would be made in a given time by a ventilator im a window, the fly of a fmoke-jack, or the vanes of a ver~ tieal windmill, with a given velocity of wind, we muft con- fider each vane as a fpiral carve; for fuch a vane, when _ ftruck by a refifting fluid, muft of neceffity pafs through a - triangular fpace, of which the fpread of the extremity of the vane forms the bafe, in the time that the wind paffes through the depth of the vane: therefore, friction and gravity being out of the queition, a fly of one vane will pafs round as quick | as.a fly with any greater number. __ Some years back I made a number of experiments upon fpiral flies moving in water, to prove what number of turns the fpiral would aéual/y make in paffing throngh a certain fpace in the direction of its axis; and [ can with confidence _ affert, that (if the fpiral be nicely made, and be fuch as flralf be generated by a radius moving angular, and at the fame time perpendicular to the plane of its angular motion *) the revolutions it will make in paffling through a certain {pace of water in the direction of its axis, well admet of calculation; but that, if the flies deviate from a fpiral, the revolutions ‘are not to be calculated with exaéine/s, being ever lefs than ~ the perfeét f{piral will perform. Wind is a fluid in fome re- - Spects fimilar to water, particularly when applied to the pre- -fent purpofe ; therefore, vanes which are to be turned by its “power, ought to be fpirals, for, if not, they will ever perform A Oy Yor the purpofe of clucidating, in the lott clear and fimple manner, the truth of the principle afferted, I caufed a vane, yr fly, to be made. This vane is reprefented by fig. 1, pl. IV. le vane moves round upon the pillar AB, which is fixed pright in aftand. The part of the pillar above the fly is ware; this carries the brafs arm CG, which may be moved p and down the pillar, parallel to itfelf, without revolving. _ * This conftruétion might be otherwife expreffed, thus: A {piral ge- erated by the circular motion of a radius, and of a line moving at tight @ngles, to the plane of the ci:cular mowon. ‘ Ts 276 On the true Form of the - ‘To this arm is fixed the ftraight wires 1, 2, 3, 4, 5,6) 7, which — are intended to reprefent the wind, moving parallel, to ftrike the vanes. To prove the truth of the principle, lift the arm up (as in fig. 1,) till the points of the wires are as high as the upper edge of the vanes, and bring the upper edge of either vane immediately under the points; then, by gently preffing the arm down, (as fhewn by fig. 2,) it will be ob= ferved that the vane is turned by a// the points prefiing upon it at the fame time, till they pafs beyond its lower edge. Now, were the vanes any other than fpirals, this could itot be the cafe; for, bring the wires to the plane vane AH (fig. 3), (which may be fet to any angle), and by preffing the arm down. as before, it will be obferved that, as the vane turns round, the points, begining from the extremity, are quitted by the i vane, which at length is a¢ted upon by the poimt next the ~ centre only: therefore it may be concluded, that the wind : would not continue to act zniformly on any fly or vane which is not conftructed on the principles of a fpiral. The fpiral vane I, fig. 1, ends, as do the reft, where the - angle of weather (or the angle which the vane makes with "| the plane of its circular motion) arrives at 35°, as this ad- — mits of the extremity of the vane being ftruek by the wind ~ with an angle of 54°; which angle, it is demonftrated, 4 will produce the greateft lateral preffure. The fhortening | of the vanes of windmills is an object of materiak moment; yet I do not mean to affert that the angle of 35 degrees is 4 the beft concluding point, fince, if more power be wanted, the length of the vanes muft be extended. The wood, of — which I formed my model, is preferved at the back of the vanes, (fee the dotted lines fig.1.) merely to give a better idea 8 of their weather as they recede from the centre. Though the number of fpiral vanes fhewn are fix, yet I do not fay that fix are fuperior to any other number; it being prefumed that more vanes on this principle might be placed with ad< _ vantage, provided the whole area of the circle be not too m crowded, which would prevent the free efcape of the wind. Vanes of a Vertical Windmill. "9 The length, breadth, and angle of weather at the extremity of a vane being given ; to determine the angles of weather at different diftances from the centre. Let AB, fig. 4, be the length of the vane ; BC its breadth; and BCD the angle of weather at the extremity of the vane, equal to 20 decrees. " With the length of the vane AB, and : breadth BC, conftrué the ifofceles triangle ABC: from the point B draw BD perpendicular to CB, then BD is the proper depth of the vane. Divide the line AB into any number of parts (five, for Inftance); at thofe divifions draw the lines 1E, 2F, 3G, and 4H, parallel to the line BC; alfo, from the points of divi- fion 1, 2, 3, and 4, draw the lines 11, 2K, 3L, and 4M, perpendicular to 1E, 2F, 3G, &c. all of them equal in length to BD. Join EI, FK, GL, and HM: then the angles 1EI, 2FK, 3GL, and 4HM, are the angles of weather at thofe divifions of the vane; and if the triangles be conceived to ftand perpendicular with the plane of the paper, the angles I, K, L, M, and D, becoming the vertical angles, the hypothenufe of thefe triangles will give a perfe& idea of the weathering of the vane as it recedes from the centre. On the fuppofition that fuch a vane were infinitely ex- ~ tended, let us confider which part of it is moft applicable to produce power with fafety. The part of the vane next the - centre, till it leffens the angle of weather to 80 or 70 degrees, fuftains but little lateral preffure; and when the weather arrives at lefs than 20 or 10 degrees, it will fuftain no more than at the centre, while, in the former cafe, the preffure tending to break the vanes is very confiderable. If we confult 4 figure, conftruéted to fhew the lateral and direét preffure that would arife from fluids ftriking furfaces with different degrees of obliquity, I think it may be.concluded, that the part of the vane between the weather of 80 and 20 degrees, will produce the greateft effect with the leaft danger. . Vou, IV. N XI. On [ 298.293 XI. On the Affaying of Iron Ores and Iron Stones by Fufton. By Mr. Davip Musuet of the Clyde Iron Works. Com- municated by the Author. A\moncst the numerous and varied attainments of human genius, the refults obtained in the praétice of the art of fufion are not the leaft to ftamp the induftry of man with that full approbation to which the moft ardent perfe- verance has entitled him. Deftitute of the knowledge of principle, and labouring under the moft violent prejudices, the artift has in all ages marked, at lengthened intervals, the coincidence of caufe with effet: upon precedent alone he has ventured to enlarge his operations, and ftake his fame and fortune. To this chiefly may be attributed his partial fuccefs; and by this alone can we account for the exiftence of manufatures, at an early period of civilifation, in this and in other countries. Although we cannot withhold our applaufe from fuch unremitting induftry, yet the deep-rooted prejudices which this implicit reverence for cuftom has fof- tered are much to be regretted. In periods remote from our time, allowance will be readily granted for perfevering in a mode of practice in which others had been comparatively fuccefsful; now, however, when inveftigation is abroad, the foundation of thefe principles ought to be tried by experi- ment, as the only flandard whereby we are enabled to afcer- tain truth or deteét error, At this impartial tribunal, errors may be detected which corrode the vitals of our manufa@to- ries; and truths which have hitherto flept, mingled in the rubbith of unenlightened tradition, be brought to full view. In our manufactories, the juft combination of art! with fcience is what we cam feldom boaft; in authors the fame happy union of theory and praétice is alfo markedly defi- cient; and we have conftantly to regret, that the want of. liberality in the individuals of the one clafs, and opportunity in that of the other, prevent us from feeling the happy ef- ~ feé&ts of this fo much defired union,. : The On the Affaying of Iron Ores, &c. 179 ~ The procefs of depriving ores of their metal by fufion in the affay-furnace, and that part particularly relating to iron, which I méan to make the principal fubje&t of this paper, lead me more immediately to make thefe obfervations. With the manufacturer, in general, the ufes and propriety of the affay-furnace are feldom admitted, or, at beft, are reftricted to fuch narrow limits as to be only capable of afcertaining the quantity of iron contained in ore or iron-ftone. The che- mift, on the other hand, intent only upon effecting his ope- ration, and of giving accuracy to the refult, confines his ob- fervations to a certain chain of fcience, and feldom or never confiders manufactures as the ultimate and happy end towards which his labours fhould be dire&ted. With whatever deference and refpeé&t we look up to the names of men celebrated for their indefatigable zeal and in- b duftry in the caufe of fcience, and with whatever fatisfaCtion ! mn we reft upon the refult of their labours as to truth; yet, in general, the practical man feels diffatisfied with the manner in which thofe fubjeéts are treated which come more imme- q diately under his own obfervation. } _ Itis I fear with fome truth that this charge is brought againft that part of the arts relative to the aflaying of iron ores. We never find, in the works of thofe whofe attention P has been direéted to this fubject, that the leaft connected q idea ever exifts betwixt the affay and the blaft-furnace, or that the agents ufed for reduétion in the laboratory can in general be applied to works in the large way. A total filence prevails amongft authors of this clafs, as to the various qua- lities of crude iron which certain ores and certain combina- tions of fluxes produce; all ores, however various, are re- duced to the a complex treatment, and the operation it- felf meafured by minutes, as if the fufibility of all the widely | ® differently-combined ores was tie fame. “¢ The celebrated Bergman even, has a degree of complexity in his receipts for the aflaying of iron ores, that feems un- N32 warthy ; a . i). x80 On the Affaying of Iron Ores worthy of the fimple elements of feience. The following one in particular feems to poffefs an air of incongruity even in the proportions, only equalled by the oddity of the aflem- blage of mixtures brought forward: «* yoo Grains of the roafted ore, two parts of the black «© flux, (equal parts of borax and nitre,) one part of tartar, «* one of fal-ammoniac, one of fandever, half of (again) “© borax, half of Slafs, one-fourth of clean foot, one-fourth © of charcoal; the whole to be covered with common falt.” This motley affociation of earths, alkalies, and falts, is re- commended as the beft flux for ALL iron ores. The author however fhews, that the advantages which it poffeffes are not complete, from the great caution prefcribed in the mode of conveying the neceflary degree of heat; and the perfection of the operation is rendered altogether doubtful by the confe- quences which the overfight of a few minutes may occafion. It cannot be well reconciled to our ideas of advancement in any art, that we have not yet difcovered a method of ope- ration more perfect than that wherein a few minutes loft or gained (which error will niore likely take place from the in- equality of heat, than the reckoning of time,) make a varia- tion from truth equal to 1-5th or 1-6th of the whole. The manufaGturer would be in a lamentable predicament were he thus circumftanced, and obliged, by fome means or other, to take the crude iron from the blaft-furnace immediately upon being feparated from the ores, left a confiderable por- tion of it fhould totally difappear. If the degree of heat pro- duced from a {mith’s forge was at all times the fame, though fupplied with fuel of various natures, and under different changes of temperature, then it is mofl probable that, by | reckoning Bergman’s time to a minute, a button of iron, accurate in its refults, might be obtained from /ome ores by the flux he has direéted. to be ufed. But I cannot conceive that this fhould be an univerfal confequence: far lefs can I - eomprehend, after a juft feparation has been effected, that . ) five and Tron-Stones by Fufion. 181 five minutes will deftroy 1-0th of the produce of metal, while the incumbent fluid protects the furface of the metallic button from the action of the atmofphere. It is not, however, my province to enter into a minute examination of the products obtained from the ufe of fuch vitreous fluxes, which are always productive of the moft oxy- genated ftate of crude iron; and the accuracy of whofe re- fults, under a flate of fuch high oxygenation, are always to be fufpected. I have frequently proved that, in ufing them, the affinity of the metal was fo great to oxygen, that a flight derangement of the crucible, which bad thrown the vitrid fluid from any point of the furface, was immediately attended by a rapid deflagration, and a confiderable portion of the jron oxydated. I thall chiefly confine myfelf to a communication of thofe faéts, which I have repeatedly confirmed, with a view of ex- tending my refults and obfervations to a more extenfive feale. I have conftantly confidered the affay-furnace as capable of affording conclufions applicable to the operations of the {melting-furnace, and that change or innovation fhould al- ways have the concurring teftimony of truth to back them, though, on a {mall {eale, before they be rifqued on one more momentous or extenfive. Influenced by fuch motives, I early rejected, as totally inapplicable to the feale of manu- facture, the numerous tribe of falts, alkalies, and earths: thefe, in the application, are fubje& to no rule, nor guided by any immediaté object of general utility, but are as arbi- trary as their authors are numerous. On the contrary, I have direéted my endeavours to the ufe of fuch agents as efleét feparation upon the large feale, and have been foitu- nate to find that the fame folvents, when properly applied, are productive of the moft perfect and finifhed refults. By the fimple application of lime or chalk, in various propor- tions, as a calcareous earth, and common bottle glafs, in the place of filex, to conftitute fulibility, [ have been able to pro- duce in the affay-furnace all the various qualities of crude N3 iron, 182 On the Affaying of Iron Ores iron, as to ftrength and fufibility. In no cafe has the refult of any affay been confidered perfe&t, unlefs the vitrid mafs found upon the furface of the metallic button exhibited a degree of tranfparency and purity of colour little inferior to flint glafs, or flightly darkened by a faint fhade of azure. In. fuch vitrifications, purity of colour is the fureft proof of the non-exiftence of iron in the flate of a fufed oxyd: the fame degree of pellucidity renders it eafy to detect the fmalleft glo- bule of metal which by chance may have been fufpended during fufion. In all experiments where a juft affociation,, of mixtures has been prefent to produce this peculiar fcoria, the quality of the iron will be found richly carbonated, and the button poffeffing a fmooth, filvery, greafy-feel furface. On the other hand, experience has repeatedly fhewn, that when the fcoria obtained in affaying approached not to the co- lour and purity of fine glafs, there remained a portion of the iron {till unrevived, in the ftate of a fufed oxyde, conveying colour and opacity to the mafs; that at certain degrees of colour, certain degrees of opacity exifted, and proportionate quantities of the metal remained diffufed in. the feoria., When the colour of this was green, the quantity of metal united was fmall; but as the green deepened, and became affociated with light browns, the quantity of unrevived iron was greater, and became much increafed as the fcoria af- fumed darker browns, or became totally black: in fuch in- tances I have found it contain, upon being re-aflayed, 12 per cent. The affaying of iron ores is fufceptible of another ex- treme, by which experiment is equally clogged, and wherein it is very difficult to obtain an accurate refult, In this cafe no perfect button of metal is found, but the portion of iron, which the ore contained is in a vat variety of various fized globules of the richeft crude iron, interfperfed in, or covering the furface of a femi-vitrified opaque mafs of fcoria, of a greyifh-blue, mottled, or whitith colour. The caufes of which, .and their ftri@ analogy to fimilar refults in the. hlaft-furnace, fhall be nay chief objeét to explain, Ta A iK r and Iron-Stones by Fufion. 184 Tn a former paper I mentioned, that if iron-ftones were fmelted without the addition of any other fubftance, the pro- du& in iron would be proportioned to the quantity of lime contained in the refpective claffes. We thall fee from the following experiments how far this is confirmed by means of the affay-furnace, and furnifh to ourfelves one’ important leffon, How far the various mixtures of ores affect the ope- ration of fmelting? tft, Into a crucible, with a well-fitted cover, I introduced 875 grains of a pulverifed filiceous iron-ftone in its raw fiate, and applied fuch degree of heat as is ufually given in fuch operations. In twelve minutes I found that the iron-ftone was in perfect fufion, much agitated, and emitting large bubbles of ignited gas of a fiery colour. In forty minutes the crucible was withdrawn; the furface of the vitrid fluid ftill continued to boil, and emit bubbles, though in lefs quan- tity. In this ftate I introduced a {mall rod through the fcoria, and difcovered the furface of a button of metal. The mo- ment it came into contaét with atmofpheric air, a beautiful combuftion took place; the metal rofe in a fpiral form to fupply the rapid inflammation, and continued till the feoria (ftill in fufion) clofed over the furface of the button. When cold, I found a perfect formed button of extremely oxygenated crude iron, which weighed 219 grains; a pro- duce equal to 25.1 per cent. from the raw iron-ftone. The feoria obtained was of a fhining black colour, firm and pon- derous, and weighed 402 grains; fo that the lofs in volatile matter was 254 grains, equal to 29 per cent. Although this iron-ftone was filiceous, yet I am convinced the lofs of volatile matter would have been greater, had not nearly one-half of the whole contents of iron remained in the fcoria, united with oxygen, at the rate of 35 per cent. I found the produce of the metallic button thus obtained white as filyer, and prefenting imperfect radii; the furface was confiderably oxydated, efpecially where the combuftion had taken effect. N4 ad, 184 On the Affaying of Iron Ores ad, I fubje&ted to a fimilar treatment 875 grains of an ar- gillaceous iron-ftone, which contained a ufual proportion of Jime ; the fufion of this powder was more difficult than that of the former, though the phenomena exhibited by both during reduction were alike. The crucible was withdrawn from the furnace in forty minutes after introduétion, and the furface of the button expofed to combuftion as before. The de- flagration differed little in point of appearance from that effected with the filiceous iron-flone: the button of crude . iron was found oxygenated, and weighed 249 grains; a pro- duce in iron from the raw flone = 28.5 per cent.: the vitrid mafs was found to weigh 354 grains; the lofs of vo- Jatile mixtures was therefore 272 grains, or 31 per cent, The fragture of the regulus now obtained was ftill white, though not allied to any degree of cryftallifation, and its furface fmoother and lefs oxydated. The glafs produced in this experiment was of a deep brown fhining colour, in many places porous, and enriched with fine tigts of colouring. 3d, The fame experiment was repeated upon $75 grains of a fine calcareous iron-ftone. The fufion of this required a violent heat of feventeen minutes, during which time the difengarement of a gafeous fubftance was moft evident ; in other refpects it exhibited the fame features, when in fufion, as the two former: the degree and length of heat conveyed was nearly the fame; and the refult obtained was a button of carbo-oxygenated crude iron* weighing 261 grains; a produce * Although in this experiment a true carbonation is effe&ted by means of the pref€nce of lime alone, yet experience has never confirmed this in the large way; nor fhewn, after a juft proportion of materials was in the furnace, that additional lime alone conferred any additional degree of car= bonation. The widely different manner in which the heat is excited, and the fubftances which are operated upon expofed to its a€tion, may account for this want of coincidence of effect. It is the fame principle that €. Clouct has lately ingenioufly applied to the fabrication of caft fteel from bar iron. Tothe decompofition of the carbonic acid alone, I attribute the advantages derived from the uf¢ of lime in the manufaéturing of crude ; iron, and Iron-Siones by Fufion. 185 produce in iron equal to 30 per cent. from the raw iron-ftone 5 fufed earths, now reduced to an opaque brown glafs ftreaked with white, 294 grains: lofs in volatile mixtures 320 grains, or 36.5 per cent. _ The metallic button produced in this operation had a fmooth cryftallifed furface ;. and, when in fufion, combined lefs readily with oxygen offered by the contac of atmo- fpheric air, than did the former two. The fra€ture was light grey, with a regular diftin&t grain; the mafs of fufed earths were difpofed afier the manner of a cryfailifation, in radii, _ thooting from the circumference of a minute circle to the extremity of one larger. From thefe experiments it is obvious that reguli of crude iron may be obtained from the different claffes of iron-ftones, of a refpectable produce, without any addition whatever; and that the tendency which thefe have to part with their iron is in the exaét ratio of the quantity of lime prefent. The following ftatement exhibits the difference betwixt the - real and partial affay of the foregoing iron-{tones. The filiceous iron-ftone, properly affayed, yielded. 34.5 per cent., but by fufion per /e only 25 ; leaving in the latter q method 9.5 mixed with the feoria. Argillaceous ftone, pro- _perly ‘affayed, gave 35.6, by fufion per fe 28.5; leaving 4. 1 mixed with the fcoria. Calcareous iron-ftone, sacle - aflayed, yielded 33.7, by fufion per fe 30; which left 3.7 _ mixed with the fcoria. _ One reafon may be advanced why the iron produced from _ the calcareous ftone was fo much more in proportion thay ‘the other two claffes: both the filiceous and argillaceous _ buttons, when deprived of their fcoria, decompofed atmo- fpheric air fo rapidly as to fuffer a little, in point of real metal, from the combination of oxygen. It was otherwife, _ however, when the furface of the calcareous button was ex- pofed: the affinity of the oxygen to the metal being lefs iron, I have for the laft three years made ufe of this truth with the - _preatett advantage in the affaying of ores and other experiments. h "7 than 186 On the Affaying of Iron Ores “i than to the carbon united with it, carbonic acid was forms ed. A review of thefe experiments leads to another con- clufion, that, without the prefence of carbon, either in chemical union in the ore, or attraéted from the ignited gas by the particles of metal, crude iron will not feparate from the ore or {tone ; and that, in proportion as the metal is ex- | pofed to inhale this principle, its produce is increafed and its quality improved. It will further appear obvious, from the various natures of icoriz which the different iron-ftones afford when fufed per fe, that there exifts a want of mixture in moft of them to form, when fufed, a fluid fo fufficiently divided that no por- tion of iron may be retained, either in a metallic flate, or in that of an oxyde. This deficiency of mixture is greateft in the filiceous iron-ftones, lefs in the argillaceous, and leaft of allin the caleareous. ‘The principle, therefore, I proceeded upon was, to afcertain what proportion of additional mixture, and of what nature, was neceflary to give the proper equi- librium to form a tranfparent {coria. When filex predomi- nated, it was found that a major proportion of calcareous earth, in the folvent or flux, fupplied the natural deficiency 5 and that the whole contents in iron were juftly revived, and fully faturated with carbon : when at any time it was wifhed to revive the metal, contained in fuch ores, poflefling ftrength with carbonation, I found that this could be eafily effected, in all proportions, by the addition of calcareous earth with a mixture of pure clay. In fhort, in every exper:ment I have © made with ores, the various natures of lime-ftones, or chalk, — with certain’ proportions of bottle glafs, have been found — capable of reviving the iron contained in all the ores which — have come under my knowledge, and of conferring upon their refpective prcduéts every degree of ftrength and fufi- bility *. In order to form an accurate judgment of the ten= dency : * Although I have frequently had occafion to mention the combinas fon of clay with iron-ftone, as the mixture which ‘in fufion conveyed _Brengi Y on™ 7 oe fs are 2 eet Pate eae a 2 aa and Iron-Stones by Fufton. 187 dency which individual ores have to afford their metal car= bonated, poffeffing firength, or otherwife, a flux of a me- dium proportion of calcareous earth and glafs is determined upon; fuch as, with an iron-ftone of that genus, would af- ford fuper-carbonated crude iron. Let the button of iron fo obtained be the flandard whereby to judge of fucceeding refults ; and let all the ores belonging to the fame mine, or ufed at the fame work, be compared with it: thefe will be found, according to their mixtures, poffeffing different de- grees of carbonation; fome of them white in the fracture, and others again as richly carbonated as the ftandard regu- lus; their degrees of ftrength alfo approaching or receding from the ftandard as they approximate or vary from the na- ture and proportion of its original mixture. To complete fuch an undertaking with accuracy, requires a minute knowledge. of the operations of the affay-furnace, and the degree of heat from time to time excited: the quan- tity of ore in fuch a chain of experiments fhould be at all times the fame, and the requifite heat conveyed and com- pleted at fimilar ftages of fufion and of feparation. Striét firength to the metal, yet I have not ventured a conjecture how far and in what manner the mechanical ftru€ture of the metal is altered when additional ftrength is thus obtained. It will be a difficult matter to de- cide, whether it is derived from the natural infufibility of the clay, by preventing feparation for a longer time, and new modifying the ftruéture of the particles of metal; or whether the acquired ftrength is entirely owing to the moleculz of the metal becoming more flattened and tenacious by a varied ftage of cryftallifation. Moft probably it is owing to both caufes, and that the former is produétive of the latter; the one the caufe, and the pther che effeé accounted for. _ We find, that from filiccous iron-ftone, which is fufed with the greateft facility, iron is obtained uncommonly white and brittle; and again, from pure calcareous iron-ftones, which are ftill more difficult to reduce than the other two claffes, we find an oppofite extreme of brittlenefs, arifing from an extra combination of carbon, which deftroys the continuity of the par- ticles to each other. Clay fill holds the medium ; and its addition alone’ Teflores a juft cquilibr.um, not of ftrength only, but of fufibility, 5 accuracy , 388 , Hints for the Formation of accuracy of refult, as to the quantity of metal, will not al~ ways be-obtained ; but a very comprehenfive knowledge will be formed of the nature of the earthy mixtures, and the © ftrength and fufibility of the metal. Once in the poffeffion of thefe, it will be no difficult matter to fuperadd a portion - of earths req quifite for perfect reduction. In two fimple ex- periments, ehratetbied sot only the real quantity of metal'con- tained in the ore is obtained, but its prefumptive ftrength and fufibility developed in a great meafure prior to its appli- cation to the purpofes of the blaft-furnace. In order to facilitate this operation, and to compare the various degrees of heat in which different experiments are effected, I conftrusted a pyrometer upon the principle of the. expanfion of metal by heat; \a reprefentation of which, and 2 defeription of its ufe, will form ‘an article for the next Number of the Philofaphical Magazine. XII. Agenda, or a Colledion of Obfervations and Refearches the Refults of which may ferve as the Foundation for a Theory of the Earth. By M. DE Saussure. {Continued ‘from page 71.] CHAP. XVIF. Obfervations to be made on the Remains and Vefliges of orga- nized Bodies found in the Earth, in Mountains, and at their Surface. : H HEIR nature, bulk, and quantity; the extent, depth,’ ¥ and other dimenfions of the ftrata where they are found *. 2, Their prefervation. Whether entire or broken, decom- pofed or not; fhelis with their pearly covering (acre) ; their colour; remains or traces of their fith, or their fkin if there be any. 0 deduce, if poilible, from thefe data, fome idea * x. A. If formed of trees. to mark down the direction of the ftrata 5 and whcther rhey are p'aced hoiizentally, or inclined either towards the fummit or the roats. C. a Theory of the Earth. 185 of the time that has elapfed fince thefe organifed beings were ‘depofsted in the bofom or at the furface of the earth. 3. The nature of the objects by which they are accom- panied; fuch as fand, gravel, flints: whether angular or round; whether there are found’ in their neighbourhood other veftiges of organifed bodies *, 4. Their nature. Whether they are lying in their natural pofition, or reverfed, and turned upfide down, fo as to afford reafon to conclude that they died on the fpots which they now occupy; or whether they have been tranfported thither by fome violent and irregular movement: whether, for ex- ample, the fhells have the fame attitude as in the bofom of the fea, the univalves on their mouth, and the bivalves on the valve that is leaft convex. 5. Whether they are in families, asin ftagnant waters ; or, on the contrary, thrown together in an irregular manner. 6. Whether all thefe circumftances are the fame through- out the whole extent of the fame bank; in the contiguous banks of the fame lands, and the fame mountains, and in thofe of the neighbourhood. 4. To afcertain whether foffil fhells are found in the moft ancient mountains, and not in thofe of a more recent forma- tion; and thus to clafs, if poffible, the relative ages and epochs of the apparition of the diferent fpecies. 8. To compare exactly the bones, fhells, and foffil plants with the living plants analogous to them; and thus to af- certain the truth of the affertion of Michaelis, that the foffil | bones of quadrupeds (fuch as the elephant, rhinoceros, > oxen, and fiags,) have not an exact reiemblance to thofe which are found at prefent alive. & g. If they are really different, to determine whether thefe differences are not varieties, or whether they characterife ‘ fpecies. — . ine pom ‘fo. Whether, on the other hand, their identity is con- | ’ 7 * To pay particular atrention to thofe of fuch organifed bodies as may / be found in the real veins. C, firmed 190 = Hints for the Formation of a Theory of the Earth. firmed with thofe of analogous living ones; viz. to afcets tain whether thefe analogous living ones are found at prefents or have been found within the memory of man, in thofe ‘countries which contain remains of them; and if the an- {wer is negative, to difcover the fituation and diftance of the neareft country where they are found. 11. If no analogous ones exift alive at prefent but in eli- mates where the temperature is very different, to afcertain whether there are any indications of their having formerly exifted, and of their having been conveyed to thofe coun- tries where remains of them are ftill found; or whether, on the contrary, thefe remains feem to have been tranfported thither by currents, tides, or any other great movement of the waters. 12. In the like manner, whether there are found in the cold countries veftiges of the productions of warm coum- _ tries; or reciprocally, whether in warm countries there are found veftiges of the productions of cold countries. _13. Whether foffil wood, or other veftiges of organifed bodies, are fituated in fuch a manner as to indicate that there were in the ancient ocean iflands abounding with animals and vegetables. 14. To ftudy with care the immenfe accumulations of bones depofited in heaps (mids), or ftrata, in the ifles of Cherfo, Ofero, and elfewhere. 15. To examine the nature of the caverns which contain them; fuch as Baumann/bele, and others*. . 16. Whether it appears that thefe caverns were the volun tary retreats of thofe animals who died there a natural death, or whether their bodies were conveyed thither by the waters}. [To be continued. } * Jn the Harz, and thofe of Gailenreuth in Franconia. C. 4 Or, whether thefe bones are found, not only in caverns, but alfo in the ftrata from which the caverns have been formed. C. ; XIII. On SES ae a y : f { 191 J | XIIt. On the Cure of Perfons bitten by Snakes in India*. By Joun WixtziiaMs, E/g. j ' 4 : | i Tue following ftatement of faéts relative to the cure of perfons bitten by fnakes, felected from a number of cafes which have come within my own knowledge, require no prefatory introduGtion, as it points out the means of obtain- ing the greateft felf-gratification the human mind is capable of experiencing, That of the prefervation of the life of a fel- low-creature, and {natching him from the jaws of death, by _*a method which every perfon is capable of availing himfelf of. Eau de Luce, I learn from many communications which I have received from different parts of the country, an{fwers as well as the pure cauftic alkali fpirit; and though, from its having fome effential oils in its compofition, it may not be fo powerful, yet, as it muft be given with water, it only requires to increafe the dofe in proportion; and, fo long as BY it retains its milky white colour, it is fufficiently efficacious. _ From the effect of a ligature applied between the part bit- ten and the heart, it is evident that the poifon diffufes itfelf - over the body by the returning venous blood; deftroying the irritability, and rendering the fyftem paralytic. It is therefore probable that the volatile cauftic alkali, in refifting _ the difeafe of the poifon, does not aét fo much as a fpecific yy in deftroying its quality, as by counteraéting the effect on * the fyftem, by flimulating the fibres, and preferving that ir« ie ritability which it tends to deftroy. ’ Case I. In the month of Auguft 1780, a fervant of mine % was bitten in the heel, as he fuppofed, by a {nake; and in _ afew minutes was in great agony, with convulfions about the throat and jaws, and continual grinding of the teeth. _ Having a with to try the effeéts of volatile alkali in fuch cafes, I gave him about forty drops of Eau de Luce in water, ye and applied fome of it to the part bitten. The dofe was re- * From the Afiatic Refearches. < ” peated SS rgz Ox the Cure of Perfons bitter peated every eight or ten minutes, till a fmall phialful was . expended: it was near two hours befére it could be faid he was- out of danger. A numbnefs and pricking fenfation was perceived extending itfelf up to the knee, where a ligature was applied fo tight as to flop the returning venous blood, which feemingly checked the progrefs of the deleterious poi- fon. The foot and leg, up to where the ligature was made, were {tiff and painful for feveral days, and, which appeared very fingular, were covered with a branny {feale. The above was the firft cafe in which I tried the effects of the volatile alkali, and, apprehending that the effential oils , m the compofition of Eau de Luce, though made of the flrong cauftic volatile fpirit, would confiderably diminifh its powers, I was induced, the next opportunity that offered, to try the effects of pure volatile cauftic alkali fpirit, and ac- cordingly prepared fome from quicklime and the fal ammo- niac of this country. {I. In July 1782, a woman of the Brahmen caft, who lived in my neighbourhood at Chunar, was bitten by a Co- bra de Capello between the thumb and fore-finger of her right hand. Prayers and fuperftitious incantations were practifed by the Brahmens about her, till fhe became fpeech- Tefs and convulfed, with locked jaws, and a profufe difcharge of faliva running from her mouth. On being informed of the accident, I immediately fent a fervant with a bottle of the volatile cauftic alkali fpirit, of which he poured about 2 tea-fpoonful, mixed with water, down her throat, and applied fome of it to the part bitten. The dofe was repeated a few minutes after, when fhe was evidently better, and in about half an hour was perfeétly recovered. This accident happened in a fmall hut, where I faw the fnake, which was a middle-fized Cobra de Capello. The — Brahmens would not allow it to be killed. In the above q cafe, no other means whatever were ufed for the recovery of | the patient than are here recited. III. A woman-fervant in the family of a gentle at See by Snakes in India. 193 Benares, was bitten in the foot by a Cobra de CapeHo. The gentleman immediately applied to me for fome of the vola- - tile cauftic alkali, which I fortunately had by me. I gave her about fixty drops in water, and alfo applied fome of it to the part bitten. In about feven oreight minutes after, the was perfeétly recovered. In the above cafe I was not wit- _ nefs to the deleterious effect of the poifon on the patient; but faw the fnake after it was killed. IV. In July 1784 the wife of a fervant of mine was bitten by a Cobra de Capello on the outfide of the little toe of her Fight foot. In a few minutes fhe became convulfed, parti- cularly about the jaws and throat, with a continued gnafh- ing of the teeth. She at firft complained of a numbnefs extending from the wound upwards; but no ligature was applied to the limb. About fixty drops of the volatile cauftic fpirit were given to her in water, by forcing open her mouth, which was ftrongly convulfed: in about feven minutes the dofe was repeated, when the convulfions left her; and in three more fhe became fenfible, and fpoke to thofe who at- tended her. A few drops of the fpirit had alfo been applied to the wound. The fnake was killed and brought to me, _which proved to be a Cobra de Capello. V. As it is generally believed that the venom of {nakes is more malignant during hot dry weather than at any other feafon, the.following cafe, which occurred in the month of July 1788, when the weather was extremely hot, no rain excepting a flight fhower having fallen for many months, may not be unworthy of notice :— "A fervant belonging to an officer at Juanpoor, was bitten by a fnake on the leg, about two tmches above the outer ancle. As the accident happened in the evening, he could not fee what {pecies of {nake it was. He immediately tied - a ligature above the part bitten; but was in a few minutes in fuch exquifite torture from pain, which extended up his body and to his head, that he foon became dizzy and fenfe- lefs. On being informed of the accident, I fent my fervant Vou. IV. O with 1g4 On the Cure of Perfons Bitten with a phial of the volatile cauftic alkali, who found him, when he arrived, quite torpid, with the faliva running out of his mouth, and his jaws fo faft locked as to render it ne~ ceflary to ufe an inftrument to open them and adminifter the medicine. About forty drops of the volatile cauftic fpirit were given to him in water, and applied to the wound; and the fame dofe repeated a few minutes after. In about half an hour he was perfectly recovered. On examining the part bitten, I could difcover the marks of three fangs; two on one fide, and one on the other; and, from the diftance they were afunder, I fhould judge it a large fnake. More than ten minutes did not appear to have elapfed from the time of his being bitten till the medicine was adminiftered. The wounds healed immediately, and he was able to attend to his duty the next day. Though the fpecies of fnake was not afcertained, yet I judge, from the flow of faliva from the mouth, convulfive fpafms of the jaws and throat, as well as from the marks of three fangs, that it muft have been a Cobra de Capello; and though I have met with five and fix fangs of different fizes in fnakes of that fpecies, I never obferved the marks of more than two having been applied in biting in any other cafe which came within my know- ledge. VI. In September 1786 a fervant belonging to Captain , who was then at Benares, was bitten in the leg by Ss a large Cobra de Capello. He faw the fnake coming to- wards him, with his neck fpread out in a very tremendous manner, and endeavoured to avoid him’; but, before he could get out of his way, the fnake feized him by the leg, and fecured his hold for fome time, as if he had not been able to extricate his teeth. Application was immediately made to his matter for a remedy, who fent to confult me; but, before I arrived, had given him a quantity of {weet oil, ‘which he drank. So foon as I faw him, I direéted the ufual dofe of volatile cauftic alkali to be given, which fortunately brought away the oil from his ftomach, or it is probable that by Snakes in uth. 195 that the ftimulating effect of the volatile fpirit would have been fo much blunted by it, as to have become inefficacious: _a fecond dofe was immediately adminiftered, and fome time after, a third. The man recovered in the courfe of a few hours. As oil is frequently adminiftered as a remedy in the bite of Makes, I think it neceffary to caution againft the ufe of it with the volatile alkali, as it blunts the ftimulating quality of the fpirit, and renders it ufelefs, Of the numerous fpecies of fnakes which I have met with, not above fix were provided with poifonous fangs ; though I have examined many which have been confidered by the natives as dangerous, without being able to difcover any thing noxious in them. The following is an inftance of the deleterious effect of the bite of a fnake, called by the natives Krait, a fpecies of the Boa, which I have frequently met with in this part of the country :— VII. On the 16th September. 1788 a man was brought to me who had been bitten, by a fnake, with the marks of two fangs on two of his toes; he was faid.to have been bit- ten above an hour before I faw him: he was perfectly fenfi- ble, but complained of great pain in the parts, bitten, with an unufual Janguor. I immediately gave | him ‘thirty drops of the volatile AGE alkali fpirit in water, and applied fome of it to the wounds. In a few minutes’ he! became’ ‘eafier, and in about half an hour was carried < away by, his friends, with perfe& confidence in his recovery, w ithout having taken a fecond dofe of the medicine, which ‘indeed did not appear 4 have been neceffary: but whether from the effect of the ; bite ‘of the fnake, or the motion of* ‘the dooly” oh which he was carried, I know not; but he became’ fick at the fto- _ mach, threw up the ‘medicine, and died in about a quarter of an hour after. The man faid that the fnake came up to him: while’ he ‘was “aitting on the ground; and that he put him away with’ hig hand “ once, but that he turned about and bit him, as defcribed, The fnake was brought tome, which - 04 1 exa- 196 On the Metallic Particles I examined: it was about two feet and a half Jong, of 2 lightith-brown colour on the back, a white belly, and annu- lated from end to end with 208 abdominal and 46 tail fcuta. I have met with feveral of them from thirteen inches to near three feet in length: it had two poifonous fangs in the upper jaw, which lay naked, with their points without the upper lip. It does. net fpread its neck, like the Cobra de Capello, when enraged; but is very active and quick im its motion. I have feen inftances of perfons bitten by fmakes, who have been fo long without affiftance that, when they have been brought to.me, they have not been able to fwallow,, from convulfions of the throat and fauces, which is, I ob- ferve, a conftant fymptom of the bite of the Cobra de Ca- pello: and indeed I have had many perfons brought to me who had been dead fome time; but never knew an inftance of the volatile cauftic alkali failing im its effet, where the patient has. been able to {wallow it. XIV. On the Metallic Particles contained in the Afbes of Fegetables. By M.Dz 14 METHERIE*. Fro M obfervations which have been made, there is no: reafon to doubt that Nature never produces any thing new on the one hand, without decompofing fomething old on the other. The procefs of boiling faltpetre, explained by the remarks of naturalifts, has fhewn that earth, freed from all falts by lixiviation, as foon as it is heaped up againft new walls expofed to the open air, becomes again. impregnated with different new falis: but thefe, however, have been formed by the experiments of Lavoifier, Thouvenel, and miytelf, through the effeéts of various artificial kinds of air. The greater part of falts are produced in the fame manner in organifed bodies; and thus plants produce vitriolated tar- tar, fulphur, nitre, both the fixed alkalies, and perhaps alfa * From the Younal de Piyique, Vo'. XXIII. ; volatile an the Afbes of Vegetables. % TO? volatile alkali. The animal fluids give fever falts, (carbonat of ammonia,) fal-ammoniac, nitre, &c. Oils both fweet and effential, flimy bedies, and extra&ts belong exclufively to the works of animated Nature. Even the different kinds of gafes combined with each other preduce new kinds, &s may be feen in plants, which convert foul ait into oxy- genated. Ought not the ether fubftances found in orga- nifed bodies to be afcribed to the like works of Nature? Becher and Henkel firft fhewed that all vegetables contain iron and gold, and fince their time this fa&t has been placed beyond any doubt. Many chemifts, particularly Lauragaisy Rouelle, Darcet, Sage, Berthollet, &c. obtained both thefe metals from plants by reducing them to afhes*. Are thefe fubftances contained in thofe things which furnifh rourith- ment to plants, or are they produced by vegetation? This queftion can be applied alfo to the earth contained in plants. _ Duck-weed and all plants of this kind grow in the pureft _ water, and we daily fee bulbous plants fhooting up in it. Van Helmont relates, that he planted a fhoot of woad, q _ weighing fifty pounds, in a hundred pounds of earth. He 4 watered it with diftilled water, and in five years it weighed | __ 169 pounds 3 ounces: ‘the earth had loft of its weight only _ two ounces. Bonnet and Duhamel reared plants in the | pureft water, and they grew as well as in the beft foil. It ay be afked, then, if particles fufceptible of being attracted 4 by the magnet could have been found in the afhes of thefe s plants, as well as in thofe of plants that grew in ficlds or gardens? The author repeated many of thefe experiments. He * calcined a-part of various feeds, and extraéted the ferrugi- ” “nous particles from them by means of a magnet ; the other part he fuffered to fhoot, aud to grow up in diftilled water. & * Since the time of their experiments manganefe has been found dif h :. ‘ U é fufed ‘evga plants, next in quantity to iron, See Scheele’s Effays. Eoir. 03 Their Ng 198 Obfervations: on Native Iron Their athes gave amuch greater quantity of metallic particles than the feeds, and produced: alfo much more earth. ‘As Nature produces, in plants, falts, oil, and flime, may fhe not, ‘in. ike manner, produce earth, iron, and gold in a metallic form ? ‘and, in this procefs, may fhe not employ water, light, and different kinds of gafes, which it appears contribute moft to the formation of falts and oils? In this manner metals would be brought very near to faline fub- ftances, which feyeral chemifts have already fufpected. XV. ‘Obfervations on nave ron Tron found in Strawberries*. ir; appears’ from the preceding article to be a circumftance well known to naturalifts, that in the athes of plants there are a great many particles fufceptible of ‘being attracted by the magnet, and which confequently muft be of the nature of iron; but that this metal has been found in plants under its original metallic form, is a fact known only to a few. Grains of gold, how ever, according to the affertion of Becher, have at times been found i in grapes, and threads of gold have been difcovered i in the roots of corn; ; tin and lead im the in- terior parts of plants; quickfilver in wood, &e.: but it has never perhaps. been thouzht pofiible that iron fhould be found amidft the corroding: juices of a plant, becaufe no metal is fo eafily “decompofed as iron, merely by the moifture of the atmofphere, acids, and the like, A certain anony mous friend of natural hiftory dined with feveral guetts, i in the month of June 1781, at the houfe of 4 his fifter, fituated ° on the road ‘to Peterfhof, not far from | Peterfburgh : ‘after dinner fome ftrawberries were placed on y the table, in a plate, as part of the deflert along with other 7 kinds of fruit. The anonymous perfon ate of the ftrawber- _| ries, as did all the other guefts, without perceiving any thing ~ * From the Journal de Phy/fique, Nov. 1783. remarkable; a Q found in Strawberries. 199 remarkable; but one of the company at laft called his atten- tion to fome hard black grains which he found in the ber- ries he had eaten, and he foon obferyed that grains of the like kind were contained in thofe which he was eating him - feif. He did not imagine that thefe grains were iron, but he however wrapped them up in a bit of paper and carried them home with him, in order that he might examine them with more attention. He accordingly tried them by a mag- net, and having obferved that they were attracted by it, he entertained no doubt that they were real native iron. It deferves to be remarked, that the perfon to whom the ano- nymous naturalift was indebted for this difcovery, and whofe veracity is free from the leaft fufpicion, afferted that he had often before found like particles of iron in the ftrawberries which he ate on the fame farm. Thefe particles were of va - tious forms and fizes, but more or lefs flatted. Their black colour was very fimilar to that of ore found in’ dirty iron mines, only that it was much paler. On clofer examination, by means of a magnifying glafs, thefe bodies appeared to be fragments broken off from larger pieces of iron, fo that, with a little affiftance from the ima- gination, traces of a regular fracture might be perceived on them. But even, whether we fuppofe that they were con- veyed into the fruit as bodies before in a ftate of exiltence, or were gradually formed in the interior part of them, the explanation of the phenomenon. will ftill be attended with difficulty. Their flatted form feems to oppofe the idea of their having been produced in the fruit; but on the other : hand, that of their being conveyed into the fruit with the ' “juices through the ftem, appears to be attended with much greater difficulty. The moft fingular cireumftance is, that fo many of thefe fruit in that diftri thould have been fur- __ nifhed with thefe fmall bodies, and that they fhould have been found exaétly in the centre. Another infiance of native iron being found, mentioned by the fame anonymous author, is perhaps lefs ftriking, but 04 yet 200 Native Iron found in Strawberries. yet worthy of attention. In the neighbourhood of the towm of Baturin in the Ukraine, there are a number of pleafant Jittle hills interfe&ted by various ravines formed by the wa- ters. In thefe ravines there are found in different places white globular maffes of calcareous ftone, which on thie out- fide bear marks as if they had been rubbed againit black . ftones ; thefe marks do not go deeper than the furface, and appear to be the work of fome mineral pigment. The fize of thefe maffes approaches near to that of a walnut: it is however difficult to break them; and the nearer you get to the nucleus, which is diftinguifhed from the external cover- ing by a green ycllowifh colour, the finer and harder the grain is found. The middle of this ftone confifts of feveral cells feparated from each other by partitions, fome of which are exceedingly thin. Thefe ftone maffes may be confidered either as excrefcences or petrefactions, and may be claffed among the carpolites or alcyonites; but this is of little con- fequence. ; What, however, deferves attention is, that, in one fpeci- men which was broken, there were found in two of the cells two fmall grains which were immediately known to be iron by their being attracted by a magnet. The fmaller fell from the hands of the obferver, and was loft almoft as foon as it had been difcovered ; but the other, which is ftill in his pof- feffion, has the exaét fhape of the cavity in which it lay, and is not much bigger than the head of a large pin. Thefe difcoveries afford a new proof that the exiftence of native iron, is neither fo uncommon nor fo problematical as mankind in general believe. XVI. Seventh { 201 ] XVI. Seventh Communication® from Dr. THORNTON, Phy- fician to the General Dif/penfary, &c. Se. relative to Pneu- matic Medicine. A REMARKABLE CASE OF PUTRID FEVER CURED BY THE INHALATION OF VITAL AIR. ; Art ER attending a family labouring under putrid fever, I was feized myfelf with the fame fever, but it was pre- vented forming by an emetic and calomel cathartic. It affailed next my wife, who being advanced in pregnancy, the fame remedies could not be applied, and the fever ac- tually formed itfelf. The fymptoms became fo alarming, that muttard cataplafms were applied to the feet; and there © arifing, towards the clofe of the difeafe, violent ftartings of the tendons, and a cold clammy fweat, with a fluttering and funk pulfe, I was induced to make trial of the oxygen air nearly in a pure ftate, and Mrs. Thornton was immediately ; _tevived by-this remedy, and, after a fever which lafted one and twenty days, recovered. A fervant in the houfe, and a nurfe, were next feized; and I had the maid taken out of bed, and made her inhale thirty quarts of vital air, mixed with twice that quantity of atmofpheric; which being re- peated for a few days, fhe was completely reftored. The nurfe had an emetic, and went home. My two children were afterwards feized with the fame fever; and being de- clared ly the gentleman who attended them paft all hopes, I ordered a carriage to be procured, and took them imme- y diately to the top of Highgate Hill, where they were com- pofed to fleep by the keen country air, and came home greatly revived ; which excurfion being repeated daily, they both recovered, to the furprife of every one. Secing the good effects of air, and of faétitious oxygen air, I adopted both in the fulleft manner in the inftance about to be recorded, the refult of which the reader will fee from the following * Thefe are all original Communications, never having been before publifhed, Epiror. letter 202 Putrid Fever cure oe Ibtol ie letter from Mr. Corpe, an eminent, Preps and apothecary. apw ards of thirty years :— To Dr. i hoysalon: Barnet, June 11, 1799+ DEAR SIR, My daughter was taken, the 27th of February 1798, with | ehills, followed by fhiverings, confiderable lofs of ftrength, and’ depreffion of fpirits. She continued fuffering much from. chills for about four or five hours, after which fhe com- plained of heat and flufhing in her face, not attended with much thirft, and was a little delirious that night. The next day the fymptoms increafed, and the debility was fo great that I was obliged, after the firft paflages had been thoroughly cleanfed, to have recourfe to wine and bottled porter, together with cordial antifeptic medicines; which plan was purfued, under your direétion, during the progrefs of the difeafe; towards the clofe of which, the poor child was fo fhockingly debilitated, that we expected every minute would be her laft, which induced you to direét vital air*, by which, and the conftant ufe of {trong vinegar, thoroughly fprayed with a hearth-brufh ail over the room and curtains of the bed, revived her aflonifhingly: but the manner in which fhe conftantly revived, after inhaling the vital air, mutt be chiefly attributed to it, as the vinegar had been ufed in the way before mentioned almoft from the very beginning of the difeafe, and was, I believe, not only of great ufe to the patient, but prevented the fever fpreading in my family. No poor human being, I believe, ever had a narrower efcape from death; and I {hall always feel myfelf under the higheft obligations poffible to you for your attention and extraordi- nary fkill in reftoring my dear child, with God’s affiftance, to, Dear Su, Your much obliged and faithful Servant, JOHN CORPE. * Sixteen quarts of vital air, mixed with the fame quantity of atmo- fpheric air, were adminiftered in the evening, Pewee I On the Glazing of Earthen Veffels without Lead. 203 P.S. Thad almoft forgot to! obferve, that the door and windows of my dear child’s room were kept almoft con-: ftantly open, and, being exaétly oppofite to each other, na- turally created a free circulation of frefh air. Obfervations on this Cafe by Dr. Thornton, . Milfs Corpe,- zt: eighteen when I faw her, was convulfed 5 and the nurfe faid, “that, if it was her child, nothing more « fhould be given ;’’ even hér mother requefted, ‘ if* there _ © really were no hopes, that fhe might not be difturbed by ** medicine.”’ What increafed the alarm was: a tradefman a few doors off had lately died of this fame fever under this eminent phyfician, leaving behind him a widow and fix children. The cafe, indeed, feemed deplorable ; but defpair fhouid never be allowed while there is life; and it autho- rifed the exhibition of the vital air, which undoubtedly con- tributed much to the recovery. of this.amiable young lady. & ———=—— ee —= XVII. Oy the Glazing of Earthen Veffels without Lead *, As it is well’ known that the common glazing by lead employed for earthen ware is of a pernicious nature and pre- judicial to the health, H. Niefeman, a potter at Leipfic, has propofed the following :—Take nitre, pot-afh, and common falt, of each half’a pound, with double that quantity of pul- verifed olafs, and mix them well together; then take a well baked flat earthen difh, cover it pretty thick with well beat clay, ftrew over the clay as much fand as will adhere to it, and fuffer it to dry. Put the above ingredients, well mixed, into this difh, and introduce it into the furnace in order that they may be all fufed together.’ The difh, however, muft be placed within another, in order that the ingredients may not _ be loft in cafe the dith fhould happen to crack: but if it be well covered with clay carefully beftrewed with fand, little danger is to be apprehended. When the ingredients have * From Neue Sammlung cekanomijcher Sebriften. b een e041 Geographical Deferipiion of - been fufed, they are to be pounded very fine in the ufual manner, and may be employed as the common glazing of fead. The colour of this glazing inclines a little to grey, but by the addition of the common calcareous fpar it ac- quires a yellow colour: manganefe gives it a brown colour $ and the addition of copper afhes a green colour. To avoidy however, every thing that has the appearance of being per- nicious, this mixture of copper afhes fhould be employed only for veffels which are to be ufed in wafhing. If this glazing is required for any particular purpofe to be dificult of fufion, a little lefs litharge may be added to it; but the quantity in all cafes muft be fo fmall as to leave no room for apprehending the leaft bad confequences. This fubftitute for the common glazing is ftrongly recommended by Pro- feffor Leonhardi. Se EBLE ED eee — ~ = ——$—$ = a Geographical Defcription of the Iles of France and Bourbon*, fe Ifle of France was difcovered in the fifteenth cen+ tury by: the Portuguefe, who called it the Ifle of Acerno, Thé Dutch took poffeffion of it in the year 1598, and gave it the name of the Mauritius, in honour of their Stadtholder Prince Maurice. It was not, however, till the year 1640 that they formed a fettlement there, at a harbour in the fouth-eaft, which they abandoned in 1712, either on account of the little progrefs it made, or on account of their eftablith- ment at the Cape of Good Hope. In 1715 the French landed at the harbour in the north-weft fide, and named the ifland Ife de France. Soon after, in 1721, the inha- bitants of the Ifle of Bourbon, at prefent called I/le de la Reunion, which is fituated at the diftance of about. ninety miles to the weft of the Ifle of France, formed a new fettle- ment under the direction of Durongay. During fiftcen years this colony was in a very languifhing condition, It was * From Labarthe’s Aunales Maritimes et Coloniales- rendered the Tfles of France and Bourbon. (205 _ Yendered produétive by La Bourdonnaie in 1735; and im _ 1764 the ifland was given up to the French government by _ the Eaft India Company. After that period it was placed _ under the direétion of a governor, and an intendant, or or- donnateur. It lies in 20° 10’ of fouth latitude and 53° 24’ of eaft lon- gitude from the meridian of Paris. According to La Caille it is 90,668 toifes in circumference, 31,890 broad from eaft to weft, and contains 432,680 fquare acres, each of 100 perches, and the perch of 20 feet. It has two harbours ; one in the fouth-eaft, or the Great Haven, and the other in the north-weft, called the Small Haven; alfo Port Louis, and, fince the Revolution, Port de la Montagne. The moft northern harbour is the principal port in the ifland. The north-weit part of it is perfectly flat, but. the fouth-eaft is covered with mountains; they are from 300 to 350 toifes in height: the highef, at the mouth of the river Noire, is 424. _ The moft remarkable mountain is called Pieterboth; it is 420 toifes in height, and its fummit ends in an obclifk, on : which there is a large cubical mafs of rock that no man has ie ie been able to afcend. _ The ifland is watered by more than fixty reams, fome of which, in the droughty feafon, become totally dry, efpe- x ¢ially fince the forefts have been cut down. The interior abounds with lakes, and rain prevails during the greater part of the year, the clouds being attracted by the mountains and forefts. The foil is covered with large or fmall ftones; it Fg _ withftands the plough, and mutt be cultivated with the hoe, bid yét it is very proper for various productions. Though of lefs 2 depth and lefs fertility than that of thet fland of Reunion, it is however, in general, more fufceptible of cultivation. The Ifland of Reunion (Bourbon) was difcovered alfo by the Portuguefe, who called it Mafcarenhas, after the _ commander of the fieet; and this name was afterwards cor- / fupted into Ma/caraigne. In the year 1642 Pronis, the _ ¢ommandant at Madagafcar, took poffeffion of the ifland for v] the (806 = Geographical Defcription of the Ifte of Bourbon. “the French government. Seven years after, this was repeated by the new commandant Deflaccourt, who gave the ifland ‘the name of Bourbon. He’ introduced into it domeftie ani- mals, which multiplied confiderably; and, on account of its fertility, fevcral Frenchmen formed in it fettlements. Tn the year 1665 two fhips of De Ia Haie’s fquadron, arrived here, and left Renaud, an officer d’adminifiration, together with twenty labourers.» The French who in 1671 efcaped the maflacre at Fort Dauphin, in Madagafear, fled to this ifland; and various fea-farmg per fons fettled in ‘it; ae em- seu themfelves m agnic thre “It is fituated about ninety miles from the Ifle of France, tb the windward. One day only. isfuflicient for going from the Ifle of France to the Ile of Bourbon, but a month is often neceffary to return. © It is about forty miles.in length and thirty in breadth. The fhores are exceedingly fleep, and piroguas only can approach them without danger ‘of being overfet. The foilis fandier than that of the Ile of France z at fome diftance from the fhore it is mixed with thofe fmooth ftones (galols) which coyer the bottom of the fea. The ground, however, in thofe parts which can be cultivated, is excellent. The mountains are exceedingly high: the three inacceffible peaks, .called the Sa/a/és, are faid to be 1600 toifes. There is here a very awful volcano, the diftri& around which is entirely burnt up; and alfo a great many gulleys, the declivities of which are fo fieep that they can- not be cultivated. The chief port in the ifland is that of St. Denis; where a drawbridge, fecured by iron chains, has been conftruéted for the purpofe of enabling boats to land. This bridge extends more than eighty feet into the fea, and at the end of it is a ladder of ropes by which people wha with to go on fhore muft afcend: im all other parts of the ifland they muft jump into the water. About fifteen miles to the windward from St. Denis is _ St. Paul, where the fea is calmer, and the anchoring ground more fecure: mariners, however, prefer St- Denis. This ifland New Publications. 207 i ifand produces annually 55,700 weight of corn, 54,300 of ‘Maize, and three millions of pounds of ‘coffee. The moft fruitful diftri& of the ifland is that of St. Sufanne, four leagues from St. Denis. The {ky is ferene, the atmofphere pure, and the water fa- lubrious. Land tortoifes, which were here formerly fo abun- dant, are found now only in the weftern part; in the other parts they have been exterminated by fhips which have _ touched at the ifland. The wild goats and wild hogs have -Tetired to the fummits of the mountains: the rabbits, quails, partridges and pintadoes brought to the ifland have none of _ them increafed, except the laft. Le Gentil mentions as found. here a bird called /’oz/eaw bleu, a very delicate kind of bats ; _ among the vegetable produétions, ebony, benjamin, the cot- ton fhrub; a great deal of timber for fhip-building; and _ among the fruit-trees, the guava, the banana, and orange _ and lemon trees in great abundance. =, , eS ee eee — a NEW PUBLICATIONS. Commentationes Socictatis Regie Scientiarum Gottingenfis, _ &c. Tranfactions of the Royal Society of Gottingen, for the Years 1795—1798. Vol. XIII. quarto. Gottingen, 1799- a ‘Tue Phyfical Clafs of this volume, to which a preface by ~ gil Heyne is prefixed, contains the five following trea- M. Sommering on an aperture in the centre of the retina of the human eye, obferved i in the body of a perfon be lor Gmelin’s aden of the grounds bright, againtt the exiftence of phlogifton—Dr, Lentin on the phofphoric - acid as a cure for caries and rottennefs of the bones.—M. 'Sommering on the trunk of the laéteal ducts in the abforb- _ ong veilels lying on the aorta, The principal papers in the iS Mathe- 208 ew Publications. Mathematical Clafs are :———Kaftner on the external furface of the fcrew.—Klugel on a new conftruétion of a compound objeét-glafs.—Kaftner on the content of the threads of the {crew and the {pace between. In the Hiftorical and Philo- logical Clafs are: A paper by Profeffor Heyne, to fhew that there was no extinétion and revival of the arts in the middle ages.—Profeffor Heeren on the diverfity and affinity of languages in the ancient kingdom of Perfia.—Gatterer’s fourth treatife on the Sarmatian extraction of the Livonians. —Profeflor Heeren on the ancient form of the Perfian gulph. _ ——Profeffor Heyne on the means of difcovering the earlieft ftate of Homer’s poems, and of refloring them. Memorias da Academia Real das Sciencias de Lifboa,’ &c. Vol. I. from 1780 to 1788. Lifbon, 1797. Small folio. 575 pages. THE Academy of Lifbon was indebted for its origin, in the year 1779, to the Duke de Ja Foes, uncle of the prefent queen, who is alfo prefident of it. The different branches of knowledge to which its attention is direéted are: Natural Philofophy, Mathematics, and Domeftic Literature: and — the Memoirs are divided into the fame number of claffes. In the Phyfical Clafs are:—Domenico Vandelli Flore et — Faune Lufitanice Specimen, which is a mere nomenclature :- ~ De Vulcano Oliffiponenfi et montis Ermini, by the fame. The ~ above two papers are in Latin, the reft in Portuguefe. Two — papers by Joao Antonio Dalla Bella on the magnetic power. ~ Various obfervations in chemiftry and natural hiftory, by — Domingos Vandelli. Obfervations on a plant hygrometer, — by Antonio Soarez Barbofa: this hygrometer is made of the ~ twifted beard of the feed of a geranium. Phyfical obfervations $ in regard to the lightning which in different years had ftruck ‘ fome of the royal buildings at Mafra. Meteorological ob- — fervations in various places by different men of learning. On the uncertainty of our knowledge refpeting the plant which produces myrrh, by Joao de Loureiro, On the nature and | real New Publications: 209 teal origin of the saclay from a plant entirely new; Which the author calls A/oexylum, by the fame. In the Mathematical Clafs are: A general f olution of Kepler’s problem de demetriendo dolio non pleno, by Jofé Monteiro da Rocha. On the true principles of the doctrine of fluxions, by Borja Gar;ao Stockler. Additions to the rule of M. Fontaine for folving problems re{peéting the -quadatare by approximation, by Jofé Monteiro da Rocha. Rec, obiervations of the eclipfes of Jupiter’s fatellites, made in i735, in the royal college of Mafra, by D. Joaquim da Afiumpcao Veiho. On determining the longitude and latitude of Lifbon, with the afronomical obfervations em- ployed for that purpofe, by Cuflodio Gomes de Villas-Boas. biervations of the fame kind, and for the like purpofe, made at Rio Janeiro by Bento Sanches Dorta. Aftrono- anical obfervations by Franc. Antonio Ciera and France, de , Oliveira Barboza. Gbfervations on the end of the eclipfe of Dec. 17, 1781, made at Carthagena, by D. Jacinto Ceruti. Solution of a probiem, propofed by the Roy jal Academy of Sciences, refpecting the approximation of M. Fontaine, by Manoel Joaquim Coelho da Maja. In the Clafs of Portuguefe Literature a feries of papers is announced on the soap and conttitution of Portugal, by Antonio Caetano do Amaral, The firft, which is heré given, contains an account of the ftaie of Portugal till it be- came a Roman province. This clafs contains alfo the two following aiticles :—On the Paftoral Poetry of the Lufita- nians, by Joaquim de Foros; and a hittorical elogium of D’Alembert, by Franc. Borja Gargao Stockler. Philofophical Tranfaétions of ihe Royal Society of London fot the Year 1799. Part I: The contents are : I. The Croonian lecture: Expeti- ments and obfervations on the ftructure of nerves, by Eve- rard Home, Efq. F.R.S.+II. The Bakerian lectures Ob- fervations upon an unufual horizontal refraction of the air, Vou. lV, PR with 210 New Publications. — with remarks on the variations to which the lower parts of the atmofphere are fometimes fubject; by the Rev. S, Vince, A.M. F.R.S. and Plumian Profeffor of Aftronomy and Ex- perimental Philofophy in the Univerfity of Cambridge.— IIL. Abftra& of a reeifter of the barometer, thermometer, and rain at Lyndon, i in Rutland, 1797; with fome remarks on the , recovery of injured trees: by Thomas Barker, Efq. ’ Commu- nicated by Mr. Timothy Lane, F. R.S.—IV. Some additions = to a paper read in 1790, on the fubjeét of a child with a dou- ble head: by Everard Home, Efq. F. R.S.—V. Obfervations on the manners, habits, and natural hiftory of the Elephants by John Corfe, Efqg. Communicated by the Right Hon. Sir Jofeph Banks, Bart. K.B. F. R.S.—VI. On the decompo- fition of the acid of borax, or fedative falt: by Lawrence de Crell, M.D. F.R.S. London and Edinburgh, and M.R. I. A. Tranflated from the German.—VI. A method of finding the latitude of a place by means of two altitudes of the fun, and the time elapfed betwixt the obfervations : by the Rev. W. Lax, A.M. Lowndes’s Profeffor of Aftronomy in the Univerfity of Cambridge.—VIII. A fourth catalogue of the comparative brightnels of the ftars: by William Her- fchel, L.L.D. F.R.S.—IX. On a fub-marine foreft on the eaft coaft of England: by Jofeph Correa de Serra, L. L. D. F.R.S. and A.S. The Appendix contains a Meteorological Journal, kept at the apartments of the Royal Society by order of the prefi- dent and council. i — , SE ae lst ek - Est}: ve INTELLIGENCE, AND MISCELLANEOUS ARTICLES. MIDWIFERY: Ix our Second Volume, p. 111, we announced a difcovery ) fiid to have been made by Mr. Herholdt, an eminent accou- eheur at Copenhagen, that the apparent death of new-born children arofe from the trachea being filled with a liquid, and that they might often be reftored by merely giving them a pofition favourable to its efux. We then expreffed a doubt __ as to the correGinefs of the obfervations; becaufe it appeared : . impoffible, from Dr. Goodwyn’s experiments, that water | . Could in any cafe enter into the trachea; and becaufe, in thofe experiments in which it had been forced into the tra- thea, it had always been abforbed, if the animal-was fuf- fered to live. Candour, however, now calls upon us to fiate, that we find the following article in the Journal de Phyfique for Floreal, an. VII. _ An important difcovery is announced in the Medico- q chirurgical Journal, publithed by Profeffor Tode of Copen- *, Herholdt has found, on opening the bodies of ftill- Mm animals, that the cavity of the tympanum was filled Sw with the liquor of the amnios and with phlegm (vifcous Water). This fluid after birth iffues by the auditory con- and is replaced by atmofpheric air. This difcovery pom. Experiments made at the veterinary fcbool bave con- irmed this bypothefis. WNaturé, in general, difcharges this quor, but fometimes it is neceflary for that purpofe to py the affiftance of art. A child cannot breathe eafily ® Vol. III. chap. 3. 1798, ' Pa wntil at Natural Hiflory. until it is freed from it. Herholdt is of opittion, that this accident occafions more apparent deaths than is commonly believed. It is not fufficient then to rmfe the child’s throat 5 it muft be placed in fuch an attitude as will facilitate the run- ning off of the water. The author has had the good fortung this year to reftore to life twelve children out of thirteen who were in the like fituation. Profeffors Abildgaard and Wi- borg have confirmed this experiment by opening five pup- pics cut from the belly of the mother.” NATURAL HISTORY. The following incident has lately attra€ted much notice at Paris :—Citoyen Felix two years ago brought two lions, a male and female, to the national menagerie. About the be- ginning of June Felix felk ill, and could no longer attend the lions; another was forced to do his duty. The lion, fad and. folitary, remained from that moment conftantly feated at the end of his cage, and refufed to receive any thing from the ftranger. His prefence even was hateful to him, and he me- naced him by bellowing. The company of the female fecmed alfo to difpleafe him; he paid no attention to her, The uneafinefs of the animal afforded a belief that he was really ill, but no one dared to approach him. At length Felix got well, and meaning to furprife the lion, he crawled fofily to the cage, and fliewed only his face againft the bars; the lion in a moment made a bound, leaped againft the bars, patted him with his paws, licked his hands and face, and trembled with pleafure. The female ran to him alfo; the lion drove her back, feemed angry, and fearful that {he fhould fnatch any favours from Felix 5 a-quarrel feemed about to take place between them, but Felix entered the cage to pacify them. He careffed them by turns. Felix is now feen frequently an the midit of this formidable couple, whofe power he has fettered: he holds a kind of converfation with them. Does he with that they fhould feparate and retire each to their cages, he has only to {peak a word; does he with that they fthould lie down to thew ftrangers their paws armed with terrible Fulminating Oxyd of Mercury. 213 ternble claws, and their throats full of tremendous teeth— at the leaft fign from him they lie on their backs, hold up their paws one aficr another, open their throats, and, as a recompence, obtain the favour of licking his hand.—Thefe two animals, of a firong breed, are five years and a half old; they were both of the fame mother, and have always lived together, FULMINATING OXYD OF MERCURY. It is well known that C. Bayen, Brugnaitelli, and others, fome time ago difcovered that nitrats in general, thofe of the metals not excepted, detonate with combuftible fub- ftances, efpecially with fulphur. That fome preparations of gold and of filver poffefs the property of fulminating without the addition of any inflammable fubftance, has alfo been known for fome time. We have now to an- nounce, that a method of preparing an oxyd of mercury, different from any defcribed by Bayen or others, that may be fired like gunpowder, and detonates loudly with a gentle ftroke of a hammer, has juft been difeovered by Mr, Edward Howard. We haye not yet received a correct account of the procefs for preparing it, but, from the wonderful expan- five force it exerts on being fired, we have not a doubt that it will prove a very ufeful difcovery, A few grains of it tried in a gunpowder proof, infiead of merely raifing the flap to fome point within the range of the attached feale, fairly thot it off; and the piece detached, on being examined, was found to have received fuch a blow from the newly-gene- rated gas as to be abfolutely dented by it, as if it had re- ceived the impreffion of a punch by means of a heavy ham- mer: the cavity was exactly the diameter of the bore of the proof, and, what is extremely fingular, of an equal depth all over. A charge of only thirty-two grains laid open, for two inches in length, the breech-end of a very ftrong muf- ket barrel on the two oppofite fides, the force being tao great to allow time to the gas ta wiredraw itfelf (if we may Pg ule 414 Effedis of Hydrogen Gas on the Voice. ufe the term) to enable it to pafs off through the calibre, —In a future Number we fhall lay farther particulats before our readers refpecting this difcoyery, EFFECT OF HYDROGEN GAS ON THE VOICE, The Journal Britannique, publifhed at Geneva by Prevot, contains the following article :—™ Maunoir was one day amufing himfelf with-Paul at Geneva, in breathing pure hydrogen air. He infpired it with eafe; and did not per- _ceive that it had any fenfible effect on him, either in enter- ing his lungs, or paffing out. But after he had taken ina very large dofe, he was defirous of fpeaking, and was afto- nifhingly furprifed at the found of his voice, which was be- come foft, fhrill, and even fqueaking, fo as to alarm him. Paul made the‘fame experiment on himfelf, and the fame effect was produced, I do not know whether any thing fimilar has occurred in breathing any of the other gafes.’”’ CHEAP METHOD OF PREVENTING THE BISAGREE- ABLE SMELL OF PRIVIES. In fome houfes, privies, when badly placed and il] taken care of, diffufe an odour as inconvenient as unhealthful ; but the means of remedying this evil is exceedingly eafy. Ifa certain quantity of milk of lime (water in which lime has been diffolved, and whitened by the fine particles of that fubftance) be mixed with a ley of afhes, or foapy water that has been even ufed for wafhing, be thrown into the fink of the privy, it will deftroy the offenfiye fmell. By thefe means, for the value of a few pence, any colleétion of filth whatever may be neutralifed. By the fame procefs conyeniencies for fick perfons may be kept in their apartments. Nothing is neceflary but to have a tub covered with a board as a feat; five or fix pounds of quicklime, a fmall quantity of afhes, and two buckets of water thrown into the tub, will prevent any difagreeable odour. It may readily be conceived that the {ame procefs may be employed in regard to a night- . rome | chair, a. Length of the Metre, &c. 215 chair, The fecal matter, after being thus neutralifed, is an excellent manure for land. LENGTH OF THE METRE. From the Journal de Phyfique we learn, that the report which has been made of the length of the metre at Paris by the learned men employed in determining the length of a degree of the meridian, has been fixed at 3 feet 11 lines and 1,296 of a line. On this bafis all the other meafures are to be formed. We {hall give-hereafter a more particular account of this operation, which leads to fome changes in the refults before given by approximation, TRANSIT OF MERCURY. *< T waited with impatience for the paffage of Mercury over the fun’s difk in his defcending node. It had never been completely obferved in that pofition, and there will not ' be another for thirty-three years. I had the pleafure of ob- ferving- Mercury enter the fun’s difk, like a fmall round black fpot, on the 18th of Floreal (May 7th) in the morn- ing, at the very moment pointed out in my new tables. The principles on which they are founded I have explained in the firft memoir read at the firft meeting of the firft clafs of the Inftitute immediately after its eftablifhment. This is the more fatisfactory, as, in the calculations for the tranfit of the 4th May 1780, there were forty minutes variation from the beft tables of Mercury. LALANDE.” PREPARATION OF BRUNSWICK GREEN, Kaficleyn has lately publifhed the following method of preparing this colour, which is much ufed on the Continent for oil painting, and in the manufacturing of printed paper. Shavings of copper are put into a clofe veffel, and befprink- led ait a folution of the muriat of ammonia. The metal firft unites with the muriatic acid, and is diffolved, and is in its turn precipitated by the difengaged ammonia, to Which it now joins itfelf. The precipitate is then wafhed P ‘4 and 216 A new Cement.—Gren’s Eudiometer. and dried in wooden boxes, or upon an extended cloth. The liquid which remains, as well as the water of the firft wafh- ing, may be employed feveral times in fucceffion for new operations, by difiolving in it frefh portions of fal ammoniac to the pot of faturation. Three parts of the muriat of ammonia ‘are {ufficient for two parts of copper, and the re- fult is fix parts of colour. This beautiful green is in Hol- Jand called Friefland green. It ig almoft always adulterated with cerufe, ‘ CEMENT FOR FILLING UP CRACKS AND FISSURES IN IRON VESSELS, The fame author has alfo made known this cement. It confitis of fix parts of yellow potter’s clay, one part of the filings of iron, and a quantity of linfeed oi] fufficient to form the whole into a pafte of the confiftence of putty. GREN’S EUDIOMETER. Profeffor Gren, m a work of his lately publifhed *, pro- pofes the following method of confiruéting an eudiometer by means of phofphorus; which, though flow in its opera- tion, will give a very accurate refult. ‘Take a fmall cylm- diic olafs tube, fealed at the one end, and divided from that end by means of a fcale into fufficiently {mall equal parts ; fill it with diftilled water, plunge it inio a bafon of the fame liquid, make to afcend a quantity of the air to be examined, and note the ftate of the atmofphere at the time, as indi- cated by the barometer and thermometer. Through a cork, fmaller in diameter than the tube, ftick a few needles, and place on the upper end of them a bit of pure clear phofphorus: faften a thread to the bottom of the cork. Introduce this cork into the lower end of the tube, with the phofphorus uppermoft, in which it will rife to the furface of the water ; fo, that the phofphorus on the needles will come in contact with the * Oxygenation of Snow and Rain, 217 the gas in the upper end of the tube. The tube muft now be eft inverted in the veffel filled with water, in which it muff remain. The phofphorus will undergo a flow and gradualcom- buition: hy means of the thread the cork from time to time may be drawn under the water to wath off the acid produced by the combuftion, and, adhering to the phofpherus, to haften the procefs. When al! the oxygen gas is confumed, and the remaining phofphorus is no longer obferved to fhine in the dark, the cork muft be drawn out; and the obferver mutt note, at a correfponding height of the barometer and degree of heat with that of the atmofphere when the procels com- menced, the quantity of azot remaining, and how much oxygen has been confumed. METHOD OF PROVING WHETHER COTTON BE ADUL- TERATED WITH WOOL, or vice ver/a. You may eafily afcertain whether cotton is mixed with wool, by fubjecting it to the aétion of the oxygenated mu- riatic acid, which will render it white, at the fame time that it makes the wool yellow. Profeffor Brugman, of Leyden, has by the fame means been able to determine with cer- tainty what part in the brain is the medullary fubftance, and what part the nerves; and to difcover the latter even at their origin, where moft concealed. OXYGENATION OF SNOW AND RAIN, In our laft volume, page 233, we gave a paper by M. Haffenfratz on the oxygenation of fnow and rain, and their effects on vegetation. In that paper M. Haffenfratz divides the a¢tion of fnow into parts. tft, As preferving plants from the great cold of the atmofphere; 2d, as cauf- ing a greater number of feeds to expand by means of the oxygen with which it fupplics them. M. Haffenfratz proved the prefence of oxygen in fnow by its rendering turnfol paper red, and precipitating oxyd of iron from a fo- lution of the fulphat of that metal, Dr, Joachim Carradori de 218 European Sugar. de Prato has, however, lately afferted*, in oppofition to M. Haifenfratz, that fnow is not oxygenated: rit, becaufe fith which lived very well in common water, did not live in recent fnow water, but died in a fhort time: 2d, becaufe {now water expafed to the action of light did not fuffer oxygen gas to be difengaged. He afcribes therefore the fudden death of fith, and the non-production of oxygen by light, to the want of that fubflance in fnow water. M. Haffenfratz has obferved, in anfwer to thefe objections, that animals may die either through the want or by an excefs of oxygen, as well as by the “want or an excefs of nourifhment, and that a mean propor- tion of both are neceflary for the prefervation of life and health : that all oxygenated fubftances do not difengage their oxygen on being expofed to the light; and that when it is dif- engaged, they fuffer only the excefs to efcape—another portion remains which cannot be taken from them by that agent. Dr. Carradori,” fays M. Haffenfratz, “‘ does not deny the refults of the experiments I have announced; he only thinks they are not conclufive, becaufe fifh de not liye in recent fnow water.’ He therefore promifes, as foon as he can procure fnow water, to repeat Dr. Carradori’s experiments; to vary them, and make new ones, in order to prove in the moft pofitive manner the exiftence of oxygen in fnow, and to de- termine the caufes of the phenomena which feem to belong to it exclufively. EUROPEAN SUGAR. We are informed by Profeffor Beckmann, that the Chamber of the Mark at Berlin has lately been at great pains to pro- mote the manufacturing of fugar from plants indigenous in Germany. Some experiments were made for that purpofe with the juice of the maple, which was refined in a fugar bakehoufe, and found to be equal to loaf fugar. Profeffor Beckmann, who faw fpecimens of it, fays, it has been found * See his experiments in the Journal de Phyfique, Ventofe, an. 7 p. 226, that, ; An Erupjion—A Tornado. 219 that the Virginian red maple, or filver-leaved maple (acer rubrum), gives more fugar than the fugar-maple (acer fac- + ¢harinum) ;, which is the more fortunate, as the latter with- ftands better the cold of an European winter. The Profeffor adds, that attempts are making in Brandenburg to cultivate this tree, and that feeds have been ordered from America, _ but they have not yet arrived. is ERUPTION OF THE PEAK OF TENERIFF, Fleurieu lately announced to the National Inftitute, that a fea-captain had actually feen the Peak of Teneriff throwing up fire. According to La Cepede, no eruption from the Peak has taken place for 400 years... Fleurieu himfelf had often feen fmoke arife from it, and found the earth near the crater fomewhat warm, TORNADO. The following account of a phenomenon of this kind; which took place at Whitelaw, in the parith of Ednam, Berwickshire, on the 3d inftant, is copied from the Kelfo - ~ Mail :— | “ The weather through the day had been calm, with foft fhowers. At feven o’clock in the evening there was obferved by many people, a little to the fouth-weft of Mr. Tod’s houfe at Whitelaw, a-denfe light-coloured cloud of a very uncom- mon appearance. It refembled an inverted cone, reaching from the ground to a confiderable height in the atmofphere. Its motion towards the houfe was flow and majeftic; a perfon of no great agility, on feeing it approach, could eafily have efcaped from it. It began at length to whirl round with great rapidity, accompanied by a loud rattling noife, The effect of ‘its amazing power was firft exhibited upon a large ftack of _ firaw in the barn-yard, which it raifed in one mafs to a confi- derable height in the air. A beam of timber, lying flat on the ground, was hurled from its place feveral feet; and it will be thought almoft to exceed credibility when it is mentioned that this beam was 33 feet long. Small flones were heaped : together 220° Deaths, together in mounds, as if by a flood. The farm offices were materially injured; fome of them, indeed, were almoft en- tirely ftript of their tiles. Human ftrength was mere weak- nefs when oppofed to this war of the elements. for the improvement of geography and navigation, and in FE order to try various nautical inftruments and time-pieces. Thefe three navigators afterwards publifhed, in concert, the + refult of their obfervations, in two volumes quarto, under the title of Voyage fait par Ordre du Roi en 17491 ef 1772, &e, ~ in which Borda’s fhare was not the leaft confiderable. An oo of the refult of this expedition may be found alfo in : “the Memoirs of the Academy of Paris for the year 1773. The public are indebted to him likewife for the beft chart ::. Canary Iflands, which ferved as a pattern for the va- able chart of thefe iflands publifhed in Spain in 1788. In the year 1787 he publifhed his valuable Defeription et Ujage du Cercle de Reflexion, in which he revived the re- eine circle propofed by Tobias Meyer in 1756. He waa ogg founder of the firft {chool for Nautical Ar teal: in enployed 224 As Deaths. employed in it. He introduced alfo an uniformity in fhips buildmg according to the principles of Euler, by which means all the French fhips of war were fo conftruéted as to be equal in point of failing, The form of the French fhips, which is founded on true mathematical principles, is un- doubtedly fuperior to that employed by other maritime na- tions: it is the moft-convenient and advantageous for quick failing, as has been acknow ledged even by fome of the beft | officers in the Britith Navy... He brought into nite Meyer’ s old method of meafuring terreftrial angles, which had been totally neglected ; Oe: ed it in attrongnneal obfervations, and invented a circle on a new conftru@tion with moveable telefcopes, which was ufed in the new meafurement. He was the inventor of the new infruments with which that meafurement was made, and of which fome account has heen given in the firft volume, p. 269, of this Magazine. He had the greateft fhare in the late reform of weights and meafures introduced in France; and caufed to be printed, at his own expence, tables of figns according to the decimal fyftem. In the year 1792 he desvuiinied: with an accuracy never before attained, the length of a pendulum fwinging feconds, at Paris. In the year 1797 he ftood on the litt of q candidates for the directorfhip. The following anecdote is related of him when a young man :—Having prefented himfelf before Camus, who exa- mined the ftudents in the Artillery School, as a candidate for admittance into the Royal Artillery, he was rejected on the feore of i incapacity. It was not long, however, before & he was a colleague in the Academy ef Sciences with his former examiner, who had entertained fuch a falfe opinion ~ refpeting him. Borda,. however, either through a love of ‘ truth, or refpect for his guondam. judge, who was now his — fellow-member, always contradicted this anecdote, ane called’ +, it an idle rumour. a Errata. In our lat Number, p. 89, |. 14, for. three read twox Page 90%” _ 4th line from the bottom, rcad—that appear as if upon his body, and Paving, &ce Page 92, 1. 23, for milla read metal, E Te ost - wh Se Sere THE AUGUST 1790. if Odfervations on the Property afcribed to Oil, of calming thé Waves of the Sea. By1.¥.W. Orro*. An idea was entertained, in the earlieft ages, that there Were means capable of calming the waves of the reftlefs ocean, and of rendering its furface tranquil and even, Arif- totle fays, that every body thrown into the fea when agi- tated, fuch as anchors, &c. tends to leffen the waves; be- caufe a kind of eddy is thereby created, which exerts itfelf in a direGtion contrary to their movement, and confequently weakens them. Plutarch + and Pliny { afcribe this power to oil; as they affert that it poffeffes a property by which it reftrains the reftlefs movement of waier, renders its furface even, and thereby caufes the rays of the fun, which are re- fracted through the waves in different diretions, to pafs to ' the bottom free and uninterrupted. What the ancients have Maid on this fubjeét is exceedingly vague and obfcure. It . ~ os - _ * From Von Zach’s Geographifche Ephemeriden, Vol. 11. Part 6. + Queft. Nar. } Ea natura eft olei, ut lucem adferat et tranquillet omnia, etiam mare, quo non alind elementum eft implacabilius. Ait, Nat. lib. iis c. 403. Vou. IV. Q does i 226 Obfervations on the Property of Oil does not appear clearly from their information, whether the. divers, to whofe teftimony they refer, made their obfetva- tions at the furface of the water, or at any depth. Befides, we are not able to afcertain whether they looked througtt the oil as through a window, or as through a magnifying glafs: for if a drop of limpid oil be let fall upon water, it will form a very fimple kind of microfcope, and magnify objects placed at a convenient depth below the water. Plutarch feems to believe, that the oil fpouted from the mouth of the diver formed, in afcending, a kind of canal, which facill- tated the paflage of the light through the water *. Of this property of oil, apparently fo wonderful, many teftimonies were afterwards produced ; and it was even con- fecrated by fuperftition for this purpofe. Thus we are told, among the miracles of St. Cuthbert, that he gave a pricft, for a fea voyage, fome confecrated oil, by which he was en- abled to allay the fury of the waves during a dreadful ftorm. Frafmus was acquainted with this property t ; and at prefent it is not unknown among feamen, particularly in Holland. Not many years ago, but before the celebrated Franklin communicated to the public his obfervations on this fubje&, the following article appeared in the Annual Regifler :— “© At the late fire in Thames-ftreet it was obferved that the il, which, to prevent the farther fpreading of the fire, had been thrown into the river, vifibly calmed the violent agi- tation of the water. This property of oil,’ fays another paragraph, ‘ appears to have been long known. It is or- dered, by an old marine law, that when goods, during a ftorm, mutt be thrown overboard, if any part of the lading confifts of oil, it fhall be the firft article thrown into the fea.”’ In modern times we have a number of experiments which feem to leave no doubt refpeéting this circumftance. I fhall * Canifius Leét. Ant. Vol. II. p. 8, ed. Bafn, + His words are: Nonnulli procumbentcs in fabulas adorabant mare, quicquid eret olei effundentes in undas, Co/lo7. € recenf. P. Rabi. Ulm. 1747-8, Pr 262. , ere io calm ibe Waves of the Sea. 224 heré give an account of the moft ftriking of them, without any fear of being thought too circumftantial, as experiments of this kind fhould all be decifive. The inhabitants of the Bermudas employ oil in their fifh- eries, in order to rerider the water of the fea clear and tranf- parent; and the Portuguefe failors, when they find the waves too violent on their entering the Tagus, pour a few flafks of oil into the water, by which means it is rendered calm, and their entrance becomes eafy. The divers in the Mediterranean, when they labour under water, and when the fun-beams are prevented from penetrating to them by {mall waves, are accuftomed to fpurt a little oil from their mouths. One Gilfred Lawfon, who refided feveral years at Gibraltar, relates, that the feamen of that place were accuf- tomed to pour a little oil into the fea, in order that they might thereby be enabled to diftinguifi: the oyfters at the bottom ; and that the fame praétice was followed on the whole Spa- ~nifh coaft. The fame thing is done on the coaft of Provence, and alfo by the inhabitants of the Hebrides. The Ragufans, with the like view, are accuftomed to fprinkle oil over the water with a brufh; and they give to the drops, under which the water becomes tranfparent, the name of windows. Tys Tiremann, a Dutch mariner, made an experiment of this kind during a ftorm, after he had loft his rudder and fome of his fails, and, with fix half ankers of oil, calmed the fury of the waves. A lieutenant of the name of May obferved in 1735, during a ftorm, that the fea was calm and {mooth around two {hips laden with cafks of oil, fome of which were leaky; and an experienced feaman, named Bewerwyk, re- commends, for fecuring boats which might be fent to the affiftance of fhips in diftrefs, to throw into the fea, oil and other fat fubftances, and even beer. In a defcription of the fhipwreck of a veffel called the Anna Cornelia, this property of oil is alfo celebrated; and fome experiments made at Portfmouth, in the time of a fiorm, were attended with the beft fuccefs. In the year 1736 Detouches de la Frenaye Q2 faw 428 Obferdations on the Property of Oil faw an old failor, by this method, fave a thip which was of ihe point of foundering. One Day was indebted for his own fafety, and that of his fhip, to half a ton of oil. Lin- nzus* learned from Gronovius, that the Dutch captains who frequented Greenland, and who were reproached with con- cealing this property of oil, always carried fome casks of it with them when they went to the whale-fifhery.. The fither- men of the Texel carry oil with them for the like purpofe. There is an inftance of a herring-bufs being faved by pourmg out oi]; while another, at the diftance of two or three hun- dred fathoms, went to the bottom. Not only oil, under which is to be underftood fat oil, fuch as olive oil, oil of rape-feed, and linfeed oil, may be employed for this pur- pofe; but alfo fat animal fluids, fuch as train-oil, &c. Ethereal oils do not poffefs the fame property: a fhip, for example, laden with oil of tarpentine, which fhould employ it with the like view, would certainly fail in its end, This oil, however, diffufes itfelf very {peedily over the furface of the water; but the covering it forms is fo thin that it is fe- parated by the fmalleft external force. At Yarmouth the failors are unanimoufly of opinion, that fat fubftances thrown into the fea prevent the agitation of the waves. Pennant+ mentions an cbfervation made re-. Spe&ting feals by the fifhermen in Scotland. When thefe animals eat any fat fifh, the fea in their neighbourhoed is uncommonly fiill; a cireumflance which induces them to fearch for them in fuch places. Sir John Pringle learned in Scotland, that the fifhermen could difcover at a great diftance places much frequented by herrings, as the fea, by the oily fatnefs which thefe fifh emit, has no apparent movement. It is obferved at Rhode Ifland, that the water in the harbour of Newport is always calm and flill as long as the Greenland fhips remain there at anchor. The caufe of this is afcribed * Reife durch Weftgothland, p. 304. + Britifh Zoglogy, Vol. 1V. fo calm the Waves of the Sea, 229° to the fea-nettle, a kind of vegetable fea-worms from oily fubftances, which are thrown together in the hold of the fhips, and the oil that oozes through between the ftaves of the cafks, which, of courfe, is pumped out with the bilge water. Seamen have alfo obferved, that the motion of a fhip, the bottom of which has been newly payed, occafions much Jefs agitation in the water than that of another which has not been daubed over with tar for along time. Such in- ftances, of which feveral more equally decifive might be pro- . duced, are fufficient to authorife this ufe of oil, in cppofition to thofe who pretend that it can be employed only in pends and other pieces of water of fmall circumference, where, by diffufing itfelf over a mafs of water not much fwelled up, it can eafily produce a tranquil furface. Thefe faéts feem to have been unknown to Dr. Franklin until he had an opportunity of making fimilar obfervations himfelf. On his paflage from England to America fome perfon told him that he had thrown into a lake a veffel con- taining oil in which flies had been drowned; that the flies, which were apparently dead, began in an inftant to moye, and went round with a circular motion on the furface of the water. Dr. Franklin afcribed this movement to a re- pulfive power maintained by the oil, which gradually iffued from the {pongy bodies of the flies. In the year1757, being at fea in the middle of a fleet confifting of ninety fhips def- tined for Louifburg, he obfcrved that the movement of the water was in one part of the fleet calm and uniform, while the water between the other fhips was thrown into great agi- tation by the wind. As he could not at that time difcover the caufe of this phenomenon, he afked the captain of one of the fhips, who replied, that the cook had, no doubt, thrown out the greafy water, which muft have rendered the fides of the fhip oily. | Franklin now paid more particular attention to this cir- gumétance ; and as he found that a drop of oil diffufed itfelf Q3 {peedily 230 Odfervations on the Property of Oil fpeedily over a large {pace of water, fo that it formed a thin covering to it, which yefleéted prifmatic colours, he refolved to make fome farther experiments; and though they did not all fueceed according to his with, he declared himfelf con- vinced of the truth of the phenomenon, One of thefe experiments I muft here mention; for, though it does not appear yery favourable to his ideas refpeéting the efficacy of oi] in calming the wayes, it at any rate fhews that oil has a great influence on the motion of water. He difco- vered that oil excites on the water a kind of waves, under circumftances when neither water alone nor oil could pro- duce the like. He fufpended a glafs half filled with water, and having. made it to {wing backwards and forwards, after the manner of a pendulum, the water remained at perfect reft. The cafe was the fame when the glafs was half filled with oil; but as foon as he had poured oil upon the water, and continued the fwinging of the glafs, the furface of the yibrat.ng oil remained fmcoth and even, while the water below it was thrown into a regular agitation like that of the billows of the fea, Franklin confiders this phenomenon, which I have con- firmed by experiments, to have in it fomething fingular, and difficult to be explained, The caufe of it, however, may perhaps lie in the differerfce of the {pecific gravities of thefe two fluids, by which they are fufceptible of the impulle to movement in different degrees; and by the effort which the oil makes,: on account of its lightnefs, to occupy the upper place on the furface, the water is violently agitated. When a drop of oil is poured upon water in a ftate of reft, as foy example in a bafon, a fine vapour immediately arifes and covers the furrtace of the water. It emits coloured ra ayS, and difperfes fmall bits of paper thrown upon the fpreading drops. When the fpace on which the drop falls is fmall, it does not Spread itfelf; but feems, as it were, to be attraéted dowards its cenire. When a bit of peper, twifted togethers in to calm the Waves of the Sea. 23% in a conical form, and foaked in oil, is thrown into water, the fluid which iflues from it caufes it to turn round with a rotary motion on its centre. In an experiment which Franklin made on a finall lake, the furface of which was raifed into large waves by the wind, the oil fpread itfelf with great velocity, but it did not mo- derate the waves. The reafon of this was, that he poured out the oil at the leeward fide of the Jake. He therefore went to the windward fide, where the waves originated ; and there.a fmall quantity of oil produced, in the fpace of feveral fquare rods, a calm, which gradually extended farther until it reached the other end of the lake; and this whole part of it, for the extent of half an acre, foon became as {mooth as ice. Of the various explanations given of this phenomenon, the following appears to be the moft natural, if not altoge- ther fatisfactory :—The air and water have an affinity for each other, and they unite in a mechanical and chemical manner when they come in contact. It is well known that air always exifts in water; that the latter can be freed from it under the receiver of an air-pump; and that, when the water is again expofed to the air, it abforbs a like quantity of it. When a mafs of air preffes, therefore, on the furface of a body of water, it combines itlelf in part with it, and forces it along with it. Now, if oil be poured upon water, the particles of the former attract cach other with too great force to admit of their uniting with the water or the air, By the covering which the oil forms on the furface of the water, the latter is prevented from coming into cantaét with the air; and the wind is conveyed over its furface, without being able to force its way into it, and to raife it into waves, The fpreading of oil in water is aferibed by Dr. Franklin to a repulfive power which they both exercife again{t each other; but it is very evident that this explanation is far fron, being fatisfactory. Even if fuch a power actually exifted, aud if the particles of the oil exercifed a repulfive power Q4 againtt 432 Ob/ervations on the Property of Oil, &e. againft the water, and an attractive power among themfelves, they would be prevented from fpreading, in an uniform man- ner, over the furface of the water: they would rather form | infulated globules; and, as they touch the water, would equally recede, and proceed towards the bank or any other folid body. Oil, therefore, as it is lighter than water, muft float on its furface when poured upon it, and, according to the laws of hydroftatics, endeavour to extend itfelf in a la- teral direction 3 and on account of the ftrong adhefion of its particles, muft form an extraordinary fine and continued ftratum on the furface of the water. This diffufion, how- ever, fuppofes that the furface of the water is horizontal : it therefore feems to follow, that the whole power of the oil confifts in preventing the formation of new waves in the places on which it has been poured; but that it cannot be in a condition to difperfe thofe which have been already formed. The billowy agitation of water fuppofes that fome ' part of its furface has been previoufly raifed. Bodies which float upon it oppofe thisrifing by their gravity, confequently the billowy movement, and in part deftroy it. It appears therefore, to fome philofophers, that this cele- brated property of oil does not confift fo much in its fluidity and toughnefs, as in its being a lighter body than water. From this it would follow, that all bodies lighter than water, and at the fame time more diftended, fuch as drops or maffes formed by oil, muft produce the fame effect, but in a higher degree. Achard recommends for this purpofe clofe leathern veffels, through which the water cannot penetrate; or, what* would be ftill better, tin-plate boxes of from fix to eight feet content in the bafe and two feet in height, which muft be filled with air, but rendered impenetrable to water. Ships, he thinks, without much increafing their lading, might al- ways carry with them fome dozens of thefe veffels or boxes, to be thrown overboard, faftened to the fhip with ropes, in cafe the agitation of the water fhould threaten danger. Achard made experiments, on a {mall feale, with tin-plate boxes of 6 ; this a ie om Communication from Dr. Mitchill, 43% this kind, which were attended with the withed-for fuccefs as when he employed oil: we know alfo, from the inform- ation of Scheldenung, that the whirlpool of the Maelftrom has been moderated by throwing pieces of wood into it. ,. To form a decifive opinion refpeéting the ‘utility of thefe means, it would be neceffary to make experiments upon a large fcale. At prefent oil appears to me to deferve the pre- ference, as it produces the effeét, not only by its being a lighter body, but alfo by its fluidity and toughnefs: befides, it poffeffes this advantage, that a {mall quantity of it is fufi- cient to fpread over a confiderable furface of water. It has been objected againit this ule of oil, that the calm- nefs produced by it has been obferved to be only of fhort duration, and that the fea afterwards redoubles its fury; alfo, that a veffel which follows a fhip failing through water calmed by the above means, is expofed to fo much greater danger; but of this circumftance no teftimony of fufficient authority has been adduced *, II. Communication from Dr. Mitcutiu, of New-York, Soewing the Utility of con/lruéting the Houfes and paving the Streets of Cities with calcareous in preference to Sfili- ceous and argillqaceous Materials, SIR; New-York, June 6th, 1799, I; you think the inclofed letter of any importance, I with you would infert it in the Philofophical Magazine. It is fo ‘ * TranfaQtions of the Society of Manchefter, Vol. II. Achard’s Sammlung phyfikalifcber und chemifcher Abhandlungen, Vol. 1. Berlin, 1784, p. 83. Effiy fur les moyens de diminuer les dangers de la mer par Palfufion de Vhuile, du goudron, ou de quelque autre matiere flotante, par. _M. de Helyveld, Amft, 1776. Letters and Papers on Philofophical Sub- jets, by Franklin, p. 438. Meifler de celebratis olei aque fuperfufi ef- SeAihus opticis et mechanicis, 1778.—The lat work treats more on the ‘geflimony of the Ancients, than on the experiments that have been made. perfectly y REA Utility of employing Calcareous Subjiances perfectly confiftent with the principle I have for fome time -been led to receive as true, that I with for its extenfive circulation, Yours with efteem and regard, Mr. Tittocr. SAM. L. MITCHILL. Copy of a Letter from Hippolyto I. Da Cofta, E/g. Brabiltie: «* DEAR SIR, New-York, May 21, 1799. * YOUR theory, in regard to the action of alkalis and cal- careous earth upon fepton, or the principle of corruption, is fo well proved in the feveral papers you have publithed, that. it is needlefs to adduce further proofs to perfons of know- ledge: but as additional fats may be ufeful to perfuade people of lefs information or more prejudices, I believe I agree with your wifes in prefenting to you an account of the influence of calcareous earth upon the putrid effluvia in the city of Lifbon, which is, I think, a proof of the moft interefting nature. “ The city of Lifbon is fituated on the northern bank of the river Tagus, about eighteen miles from its mouth: it is about fix miles in length, and its breadth is in fome parts two, in fome three miles, although jn other parts very nar- row. In the moft inhabited part of the city there are feven hills or mountains, which, of courfe, occafion declivities and lower fituations. This city may be divided into the nec and o/d city ; becaufe there is a {pot which was overthrown by the horrible earthquake of the year 1755, and was ree built: Icall, therefore, this part the new city. The ftrectg in this quarter are very regular, the buildings neat, and the pavements for foot pafiengers very commodious; but the fituation is almoft all very lew, ‘¢ The old city, or the part which did not fmffer fo much in ihe earthquake, and preferves its ancient buildings, is in the Gothic tafte, with narrow and crooked ftreets, in the moft of which there are no pavements for foot paffengers; the houfes are fo high, that, in fome of the narroweft ftreets, the fun cannot in the Confiruétion of Cities. 235 cannot be feen but two or three hours every day, viz. from eleven before noon to one after noon. In the new city there are gutters or fewers below the earth to conduct the water and impurities from the houfes and ftreets to the river : but in the old city there are none of thefe. ** As the houfes are, in general, five or more ftories high, and the ftreets narrow, it is eafy to conceive the thicknefs of population, and, of courfe, the vat quantity of impurity that comes into the ftreets every day, which, with the water and other liquids poured in hikewife, keep always there a vatt quantity of dirt. A great fum of money is appropriated, I know, and fome pains taken, to preferve the cleanlinefs of the city: but without entering into the difcuffion how this money is employed or difpofed of, which is but very little interefling to our prefent inquiry, it is true that very often T have been obliged to make a great turn to go a fhort dif- tance, becaufe it was impoflible to crofs the {treet through the dirt; and very often I have feen dogs, cats, and other dead animals, lie in the fireets, «© There is in every houfe (chiefly in the new city) a privy, with a canal which goes up to the higheft ftory ; becaule, as the feveral ftories are inhabited by differen want fuch a convenience in every one: t families, they but this canal emits Jways a very bad {mell, by the accumulation of inipurities \within its walls, which, from the form of its conftruétion, not be wafhed but with water let in by a fmall orifice orhole, There is alfo, in many houfes, a place in the infide f the fircet-door for making water, which contributes its oution of bad fmell; and the houfes are in general nat ery clean. * Befides all thefe fources of putrid exhalations, there are great many wharves, and much naked fhore, which, being Reovered by the ebb-tide, prefent to the fan a furface co- ered with dirt and fea-weeds undergoing putrid fermenta- on. The mouths of the fewers I have mentioned above go the wharves, and are likewife bare at low water, The fluid 8 which, 436 Utility of employing Calcareous Subjlancet which comes from thefe fewers contains io many infecting matters, that its ftrong putrid fmell can fearcely be endured. “¢ After this fhort defcription of the police of Lifbon, in regard to its cleanlinefs, every body would draw the inference, that endemical difeafes muft reign, not only in the fummer, but in the winter time, feeing that the accumulation of the dirt in the flreets is incomparably greater in the winter than in fummer. The connection there is between malignant diftempers and dirtinefs is very well known, and exprefsly marked by Tiffot (Avis au Peuple fur la Sant», chap. i. § 7). Happily, Sir, the contrary is the fact: Lifbon 1s one of the moft healthy fituations I know, and its inhabitants do not fuffer but the common difeafes to which the human body is fubjected. Many people go from England and other countries to Lifbon, in certain difeafes, to enjoy the benefit of a falubrious place, and very often to fpend the fummer agreeably in a good and wholefome climate. «© What then can be the caufe of this apparently phyfical contradiction between the impurity and corruption we Set through Egypt and Syria. ~ 243. would be neceffary to return, as the people of the town were in purfuit of them, and would not permit them to go and difinter the treafures of Ara/chié. They neverthelefs conti-. nued their journey for two days, and at the end of that time arrived at the place defcribed to them. It was not far from the plain of Gegabib. Mr. Brown here found an ifland in the middle of a fmall lake of falt water, which contained mif-fhapen rocks in abundance, but nothing that he could pofitively decide to be ruins; nor was it very likely that any fuch fhould be found there, the {pot being entirely deftitute of trees and frefh water. Mr. Brown, however, had the cu- riofity to approach nearer to thefe imaginary ruins, and ac- cordingly forced his horfe into the lake. The horfe, from fatigue and weaknefs, or original inability to fwim, foon found himfelf entangled, and could not keep his head above water. Mr. Brown fell with him, and was unable to de- tach himfelf; and when he at length found himfelf on dry ground, the circumftances he was under prevented him from making any farther obfervation on this ifland and lake. After vifiting this place, Mr. Brown and his attendants continued theit journey fouth according to the agreement made with the guides, but found the purfuit equally fruitlefs. At the end of the third day, having arrived in lat. 28° 40, or nearly fo, they became much diftreffed for water: they remained a whole night in fufpenfe concerning their deftiny, when at length a fupply of that neceflary refrefhment was found. As they did not, however, difcover any thing that bore the leaft refemblance to the object of their fearch, they were obliged to think of returning, which they did; and, falling into the ftraight road from Siwa to Alexandria, ar-— rived at the latter on the 2d of April 1792 *. Mr. Brown, after remaining fome time at Alexandria, to * Mr. Brown fays, that an opinion has been communicated to him, that Siwa is the Siropum of Ptolemy, and that the building defcribed was pro- bably coeval with the temple of Jupiter Ammon, and a dependency on it, D'Anville fuppofes Siwa to be Mareotis. R 2 recover 244 An Account of Mi — =/s Travels tecover from the effects of his journey, commenced, on the sft of May, another to Rafhid, where he ftaid five days; and on the 6th of May embarked with a view of proceeding to Terané, a town fituated on the left of the mott weftern mouth of the Nile, at a very fmall diftance from the river. From Terané Mr. Brown made an excurfion to view the lakes which produce natron, and to obferve that production in its nafcent ftate. One of them was very irregular in its form, fo that it was not eafy to fay what might be the quan- tity of ground covered with water. It is higher in winter than in fummer ; and, at the period when Mr. Brown viewed it, he could no where difcover that the breadth of it ex- ceeded a mile: its length might be nearly four. Towards the end of fummer thefe lakes, it is faid, are almoft dry, and the fpace from which the water has retired is then occupied by a thick depofition of falt. Not far from the eaftern ex- tremity a {pring rifes with fome foree, which much agitates the reft of the water. Clofe to the fpring the depth was far greater than our traveller’s height, m other parts it did not generally exceed three feet. The thermometer near the {pring ftood at 76, while in the open air it was at 87. The more weftern Jake differs not materially from the eaftern, in fize, form, or productions: the colour of the water in both is an imperfeét red, and, where the bottom is vifible, it ap- pears almoft as if covered with blood. Salt, to the thick- nefs of five or fix inches, lies conftantly in the more fhallow part. How thick the fubftance of natron commonly is in the lake, Mr. Brown did not accurately determine; but thofe employed to colleét it, reported, that it never exceeded a cubit or common pike. Having fpent two days and part of a third in the vicinity of the lakes, Mr. Brown’s attend- ants grew tired, and he was obliged to return. After a fhort interval he embarked for Kahira, and arrived there on the 16th of May £792. Mr. Brown being determined to undertake a journey to Abyffinia, employed the greater part of the fummer, which he i ek ee ; W = ee «12 SRE era, through Egypt and Syria. 245 he fpent at Kahira, in learning the Arabic language; but fill judging that he fhould have occafion for an interpreter, he took care to provide a Greek, who, befides his native lan- guage, was acquainted with the Turkifh, Arabic, and Ita~ lian: he had alfo with him a Mahommedan of the lower clafs of the Kahirines, who, as belongs to that character, was prepared for every office. Thus provided, he fet out by water on the roth of September, and on the 8th day reached Affiut. Having fpent about fourteen days here waiting for a boat, he was at length able to hire one of a moderate fize; and leaving Affiut on the 4th of October, arrived on the 11th at Girgi, formerly the capital of Upper Egypt. On the 17th he arrived at Dendera, the ancient Tentyra, where he faw the noted temple, the mott perfect {pecimen of Egyptian architecture now remaining. It is in the form of an oblong fquare, 200 feet by 150, Pococke fays 145, and is now almoft buried in the fand. The fame night, about twelve, he reached Ghenné, the ancient Coene or Ceenopolis; and on the 23d came to Akfor, the ancient Thebes. After paffing three days in and around thefe ruins, Mr. Brown proceeded on his voyage up the Nile, and on the 31ft arrived at Afftian, the ancient S¥ene, where he re- mained three days, contriving, if poffible, to purfue his route up the river; but a war having arifen between the Mam- laks of Upper Egypt and the Cathef of Ibrim, no one was fuffered to pafs from Egypt to Nubia. The caravans had all been ftopped for many months, and not even a camel could be procured. Our traveller being therefore confirained, with deep regret, to abandon his defign of penetrating to Abyf- finia by this route, gave up all hope for that feafon, and began to think of returning. Mr. Brown, therefore, left Affaéan on the 4th of Novem- ber 1792, and, proceeding rapidly down the Nile, arrived at Ghenné on the 7th. From Ghenné he made a {hort excur- fion to Coffir; but he did not think it advifeable to ftay bong there, as the people were highly incenfed at that time R3 againft 246 Travels through Egypt and Syria. againft the Franks on account of the following circumftance, which had taken place there three or four years before. An Englifh veffel, commanded, as is faid, by a Captain Mit- chel, having moored there, a quarrel arofe between the crew and the natives refpecting a fupply of water, which is a com- modity difficult to be procured. From a violent contention blows enfued, and the captain thought himfelf juftified to fire upon the town ; in confequence of which feveral perfons, fome fay fourteen, were killed, and much damage done, The natives were exceedingly exafperated, and fwore to fa- crifice the firft Englifhman that fhould fall into their hands. Mr. Brown found little to reward him for expofing himfelf to the danger of this excurfion, except the fight of fome cu- rious rocks, which he thus defcribes :—The roads we travelled in going to Coffir, as well as in returning, have fomething in them very remarkable: the rough and lofty rocks of gra- nite and porphyry, with which it is on all fides environed, have a magnificent and terrific appearance; and the road between them, which is almoft level throughout, gives the idea of immenfe labour in cutting it. All thefe circum- fiances concur in teftifying the importance Coflir muft once have had as a port. In the route we took in going, at cer- tain diftances, on the higheft rocks, is obfervable a fucceffion of {mall ftru€tures, formed with uncemented flones, and which, by the marks of fire within them, feem to have ferved as fignals.. Thefe are numerous, but they are too rude to enable one to fix any time for their erection. They appear to me to be pretty ancient. The red granite is in vaft quan- tities; and the chain of rocks, confifting of that fubftance, appears to extend itfelf in a north and fouth direction. Huge rocks of porphyry, both red and green, are diftinguifhable ; and, as appears, more of it in the road we purfued in going than in that by which we returned. I obferved ruins of alabafter in both, but particularly in returning. The verde antico, it was long before I could difcover; at length I found — jt in returning, by the figns Bruce had deferibed. In fhort, the a eo —e— awn .- : Means for uving the Crews of Shipwrecks. 244 the route unfolds a treafure of marbles that aftonifhes the beholder, and demonftrates, that, on any future occafion, the quarries may be again wrought, and modern architecture equal that of the beft ages of Greece or Rome as to richnefs and durability of ornament, if ever it fhall in juftnefs of proportion, fimplicity of tafte, or unity of parts in one fub- lime whole, which, indeed, feems fufficiently problematical. On the 21f of November Mr. Brown returned to Affiut, and on the 3oth fet fail for Kahira, which he reached on the 8th of December. [To be continued. ] IV. Means propofed for faving the Crews of Veffels Soip- wrecked near the Coaft. By an anonymous Author”. Eucur or nine years ago, being much ftruck by an ac- count which I read of the fhipwreck of twenty-four perfons who perifhed fo near the {hore that their cries could be dif- tin&ly heard, an idea immediately occurred to me, of endea- vyouring to difcover fome means proper for faving the crews of fhipwrecked veffels, at leaft under fuch circumfiances, that is to fay, at the diftance of forty or fifty fathoms from the fhore; for I did not then imagine that it could be done at the diftance of two or three hundred, as I afterwards dif- covered. I perceived at firft that the only means to fave the crew of a veflel in fuch a ftate, would be to eftablifh a rope of communication from the fhore to the fhip. After examin- ing a number of means, both ancient and modern, I fixed on a bomb or cannon-ball (a bomb I think preferable), to which fhould be faftened the end of the rope, extended after- wards in a zig-zag direction before the mortar or cannon, or fafpended on a pizce of wood raifed feveral feet. But as it was neceflary to know if the cord would not break by the * From a late French Journal. R 4 force 248 Means for faving the Crews of Veffels force of the explofion and the velocity of the motion, f thought it proper to confult profeflional men. I wrote to fome officers of the artillery in garrifon at La Fere, and they almoft all replied that the rope would infallibly break. Not fatisfied with this anfwer, I happily conceived the idea of making the experiments on a fimall feale. I caufed a piece of the barrel of a mufket to be filed into the form of a fmall mortar of 18 lines in length internally; and having tied a packthread to a common ball of lead, I made an experiment, which perfecily fucceeded, as did a great many others which I repeated afterwards ‘even with the ftrongelt charges of powder. I communicated this fuccefs to thefe officers of artillery, who replied, that there was a great difference be- tween a quarter of an ounce of powder and four: or five pounds employed for a bomb; and, in thort, that the rope would break. | Being defirous to afcertain what truth there might be in this affertion, I repaired to a large iron furnace, where I re- -mained ten days, and where I caufed a mould to be formed for a four-inch mortar and a bullet of the fame calibre: I had them both caft, and made an experiment with’a rope — three or four lines in diameter and c7ghteen ounces of pow= der, which fueceeded. J then came to Paris, where, after ftaying eight months, I obtained an order from government to make my experiments on a grand fcale even at La Fere, where I had to expect men prejudiced againit the fuccefs of gy attempts. When I went thither they perfifted that they would not fucceed. I knew, however, what I had to de- pend upon, as I had already made experiments. In fhort I repeated them, and they completely fucceeded. The firft day, nothing being done in a proper manner, fome of the experiments failed; but things being arranged better next morning, we repeated them feven times without once fail- ing, viz. four times with a mortar of eight inches, and three with one of twelve, augmenting each time the charge of Pera on the Ly Sbipwrecked near the Coaft. 249 the powder from the weakeft to the ftrongett. The fpecta-~ tors having judged that this number was fully fudicient to eftablith the truth of the difcovery, no more were made. { fhall now proceed to other means, which I have devifed not only fer faving the crews of veflels, but alfo the greater part of the cargoes when expofed to danger near the coaft, iit, It mufi be remembered, that, in fuch circumftances, the only thing neceffary is to get a cord of communication conveyed to the veffel in danger. It ought to be’ remem, bered alfo, that a veflel is never caft away or perifhes on the coafi, but becaufe it is driven thither againft the will of the captain, and by the violence of the waves and the wind, which almoft always blows from the fea towards the fhore, without which there would be no danger to be apprehended: confequently, in thefe circumftances, the wind comes always from the fea, either directly or obliquely, and blows towards the fhore. A common paper kite, therefore, launched from the veffel and driven by the wind to the fhore, would be fuflicient to fave a crew confifting of 1500 feamen, if fuch were the num- ber of a fhip of war. This kite would convey to the fhore a firong packthread, to the end of which might be affixed a cord, to be drawn on board by means of the firing of the kite ; and with this cord a rope, or as many as fhould be ne- ceflary, might be conveyed to the {hip.—It may be readily conceived that I cannot here enter into any detail concern- ing various circumftances relating to this fubjeét which it might be neceflary to mention. 2d, A fmall balloon, of fix or feven feet in diameter, and raifed by rarified air, would be alfo an excellent means for the like purpofe: being driven by the wind from the veflel to the fhore, it would carry thither a ftring capable of draw- ing a cord with which feveral ropes might be afterwards gonveyed to the veflel. Had not the difcovery of citizen Montgolfier produced any other benefit, it would be entitled jon tus account to be confidered as of great importance. 3d, A 250 On the diffirent Kinds of Cadmia, and 3d, A fky-rocket, of a large diameter, would be of equal feryice. It would alfo carry, from the veffel to the fhore, a firing capable of drawing a rope after it. C. Ruggieri, whom I have confulted on this fubject, told me, that he made fome four inches in diameter, which rofe to a great height ; and that, with a ftring attached to them, they would go to the diftance of four or five hundred fathoms, which is more than would be neceffary. They may be kept in a ftate fit for fervice two years, if depofited in a dry place. Laftly, A fourth plan for faving the crew of a fhipwrecked. ‘veflel, is that of throwing from the veffel into the fea an empty cafk with a cord attached to it. The wind and the waves would drive the cafk to the fhore, and afford the means of eftablifhing that rope of communication already men- tioned. Each of thefe methods may be improved, but I cannot at prefent enter into any detail *. = ae V. On the different Kinds of Cadmia, and particularly thofe of Zinc and Cobalt, By 1.1. BinDHEIM of Mofcow +. ry iT HE fureft method of claffing minerals is without doubt to arrange them, not according to their external chara¢ters, but according to their internal component parts. For, though the former in fome meafure ferve for difcrimination, and are therefore not altogether ufelels, they are not fo precile and certain as to form a bafis for a fyftem of mineralogy, * The author of the above papers fays, that he announced his difcovery in the Afriches de Paris on the 29th of January 1794. However this miy be, we know that one of his methods, that of conveying a rope to the fhore, by attaching it toa bullet or bomb to be afterwards fired froma cannon or mortar, was propofed a few years ago by a ferjeant or officer of artillery at Woolwich, named Bell. Some experiments of the fame kind made at Portfmouth, we believe, an{wered expectation. The ufe ef a kite or rocket feems to deferve attention ; and we do not hefirate to fay, that the former could hardly fail of producing the defired effect. At any rate it might be eafily tried. Epiror. : + From Neve Nordifcke Beytége, by Profeffor Pallas, Vol. VE. fince Oi ai particularly thofe of Zine and Cobalt. 251 fiace the attentive naturalift is fufficiently taught, by expe- rience, that in the mineral kingdom fubftances of the fame ) genus, though different in external form, confift often of the fame component parts; and that other bodies of the like kind differ in their component parts, though perfectly alike in their external appearance. As this is the cafe, we can find no better guide to conduc. us to an invariable claflifica- tion, arrangement, and definition of mineral bodies than 4 chemiftry ; a knowledge which muft be united with that of _ the external chara¢ters of minerals. To give an inftance of the uncertainty which arifes when thefe are feparated, I fhall here mention thofe ores which _ are known by the name of cadmia; for it would feem, by the many improper denominations which are often founded on their external characters, as if we were almoft conducted back to the dark age of Cadmus, from whom the Europeans oe ee are faid to have firft learnt the art of fufing ores on a large _ feale, and from whom, in all probability, the term cadmia had its origin. In this refpect chemical knowledge is a better euide than external characters, and the names thence deduced, and often very improperly ; it enables us to define minerals with more accuracy, and conduéts us nearer than the latter to the real knowledge of nature in this department, without which all mineralogical knowledge mutt be uncer- tain and imperfeé. As it would be fuperfluous to fay more on this fubject, I fhall, for the prefent, confine myfelf to the cadmias, and thofe ores alone which, when decompofed in a proper manner, and fully purified, yield thofe metals called zinc and cobalt. Of Zinc. Ores that contain zinc are found in numerous varictics and of different forms. Sometimes they are combined with oxygen and the fulphuric acid; and fometimes there are found in them, befides zinc, various foreign component parts, fuch as argil and filiccoqus earth, a little iron, lead, and, 252 On the different Kinds of Cadmia, and and, at times, alfo a fmall portion of copper. In blende the fulphur is combined with iron, and the particles of zine are {cattered through the mixture.. The fo called furnace calamine is obtained by the fufion of fome kinds of lead ore when the particles of zinc are fublimated by ftrong heat to a cooler place of the furnace called the zie fool, where they adhere in the form of a grey or yellowifh ftone. In preparing brafs, and other operations of the like kind, the fublimated zinc calx is collected under the name of white nicht; but what adheres lower down, and becomes. a hard mafs, is called grey twtia; and this fubftance, as fome fulphureous vapour feems to adhere to it the longer it lies expofed near the fmelting houfes, becomes, by the effects of the atmofphere, always more proper for ufe. Befides the above, we have zine calx, zinc fpar, tutanego ore, the laft of which was firft difeovered in China; but Iam convinced, by experiments, that a like ore, which is natural flowers of zinc, is found in Germany in the Thomas-ftollen at Blei- berg. We have alfo zeolite-formed calamine, zinc blende, glittering blende, black blende, reddith brown, phofphorifed, greenifh-yellow, white, and ycllow blende. Such kinds are found in England, Siberia, China, Sweden, Silefia, Saxony, &c. In examining thefe fubftances various chemifts have ren- dered * great fervice to mineralogy, particularly Brand and Schwab, counfellors of the mines in Sweden; and thefe were followed by Julti, Pott, Henkel, and, above all, Mar- graaf, who employed great care and accuracy in fufing and examining them; but Bergmann, to whom {cience is fo much indebted, has given moft excellent models for the decompofition of thefe ores. Whether there be native zine or not, has never. yet been fully afcertained ; and we mutt {ull remain in doubt until the account of its being found in the ifland of Naxos, in the Archipelago, be better con- firmed. The zine ore of Goflar, that found in Cornwall, and a Jittle of the Swedifh, can be rendered ufeful and pro- 6 ductive. RN Ginec ts: par: WV tbai¥ i 3) wwe uy sitll Pan Awe CT 7 F. 253 duétive. The zinc obtained from China, under the name of tuztanego, is confidered to be purer than the German, and therefore a fmall difference is obferved in their fpecific gra- Vitics. - The properties of zinc feparated from its ore, and puri- fied, are, that it fearcely undergoes any variation in atmo- fpheric air or in water; and that, by the addition of copper, in different proportiafis, you obtain brafs, pinchbeck, prince’s metal, Manheim gold, &c. All acids deprive it of its in- flammable matter, and diffolve it with effervefeence. With the vitriolic acid it gives a cryftalline falt, which is fulphat of zinc, or, as it is commonly called, white vitriol. That white vitriol which is obtained not in a cryftalline form, but in white maffes like refined fugar, contains often a mixture : of foreign metallic particles, fuch as iron, copper, and lead; but it may be purified by adding to a folution of it pure zinc, _ by which the above metals will be precipitated: if the fo- Jution be then ‘filtered, and expofed to cryftallife, you will obtain pure white vitriol. 7 a By the nitrous acid, zinc is diffolved with a ftrong effer- vefcence and in great quantity producing cryftals: if you pour alcohol over thefe and diftil them, you will obtain very good edulcorated fpirit of nitre. It diffolves alfo in the mu- riatic acid, and emits a ftrong offenfive vapour ; this clear fo- lution faturated cannot be brought to fhoot into cryftals: if you reduce it by evaporation to a gelatinous mafs, and place it in a retort over the fire, you obtain, in the fame manner as when you diftil zinc with fai-anmmoniac and corrofive fublimate, butter of zine of a fomewhat thick confiftence. It is foluble alfo in aqua-regia, and by that acid gives a triple neutral falt, in the fame manner as fal-ammoniac. It diffolves likewife in concentrated acetous acid, and fhoots in- _. tocryfials: the remaining acids, viz. of {parry fluor, arfenic, borax, fugar, tartar, forrel, citrons, ants, phofphorus, and fat, exercife an aétion over zinc alfo. The alcaline folvents do the fame ; and the procefs fucceeds beft with a concen- trated aha On the different Kinds of Cadmia, &e. trated folution of the volatile, not cauftic alcali, during which an effervefcence is obferved, and by which the zinc exhibits traces of an acid: the produce is cryftals of a neu- tral falt. Flowers of zinc, like zinc itfelf, are foluble in an acid 5 but with this difference, that no effervefcence takes place. Thefe flowers are produced during the fufion of zinc in an open crucible, when the heat is incteafed to above 370 degrees. The metal then inflames with a whitifh-green flame of a dazzling brightnefs, which feems to diffufe over the faces of thofe prefent a death-like palenefs ; and the metal, by being deprived of its inflammable matter, (united to oxygen,) is con- verted into a tender calx, which, by the violence of the in- flammation, is, on account of its lightnefs, carried upwards like wool or a cobweb. Zinc, calcined in this manner, is called the flowers of zinc, and alfo philo/opkic wool, not to mention other fingular appellations of the alchemifis. During this operation zinc exhibits fome phenomena, fuch as the fmell, the flame,. &c. which are fimilar to thofe that occur during the combuftion of phofphorus; and therefore people were led to fuppofe that the phofphoric acid was contained in zinc. By the above procefs the weight of this calx is in- creafed a tenth part, and, as fome have remarked, even more, and at the fame time it hecomes fixed. When expofed on coals to the blow-pipe, it becomes yellow, and on cooling refumes its whitenefs, which is a proof that the flowers of zine are genuine. It can be fuféd into a yellowifh-brown glafs, and, by adding the inflammable matter, can be reduced in clofe veifels. In a clofe veffel, expofed to a violent heat, zinc goes over in a metallic form, and by thefe means acquires the pro- perty of creaking, when it breaks like tin. It can alfo be brought to fuch a ftate that it may be drawn out into thin — plates, and, be flatted between metal cylinders; fome fpeci- mens of which, by M. Sage of Paris, and M. Kratz of Berlin, | I have in my poffeffion. Zine may be combined with the — 5 greater Defcription of an Affay-furnace. a58 greater part of metals, but not with lead, iron, or bifmuth ; and it may be amalgamated with quickfilver. This amal- gam of zinc is very proper for ftrengthening the power of an electric machine, and Higgins has giyen a prefcription for _ preparing it. In the dry way it has the greateft affinity with copper, and produces with it a more or lefs yellow compofi- tion, which can be obtained by no other metal. In this re- fpeéct, then, it is effentially different from all other metals, and becomes itfelf a very ufeful one, as it is ufed for brafs, pinchbeck, prince’s metal, bronze, Manheim gold, and in " fire-works, &c. It is very remarkable, in regard to zinc, that neither ful- phur nor liver of fulphur * produces on it any effect; whereas gold, which fulphur cannot overcome, is diffolved by liver of fulphur. On this occafion I cannot omit making mention of the celebrated alkaheft of Refpur, who believed, that when he alcalifed zinc and rendered it cauftic, and had obtained from it a purple-coloured mafs, volatile in the open air, he had found out a menfiruum, by which, he could radically dif- folve all metals. A paradoxical pofition, which was long adopted by the gold-making alchemifts, but which has never been realifed. [ To be concluded in next Number. ] VI. Defcription of an Affay-furnace, with an Apparatus for meafuring the Degree of Heat employed. By Mr. Davip Musuer of the Clyde Iron Works. Communi- cated by the Author. ix my laft paper I mentioned, that, in order to facilitate the operations of the aflay-furnace, and to compare the va- rious degrees of heat in which different experiments are * Tt has been afcertained that zinc and fulphur can be united; but the proces is difficult, on account of the cafy oxidation and volatility of the zinc. Sce Mer, de Dijon, 1783. effected, 256 Defcription of an A {Juy-furnace. effected, I had conftructed the pyrometer which I am now about to defcribe. It can in no point of view be confidered as an univerfal inftrument, as its feale will be entirely local, and vary according to the conftruétion and exigencies of the furnace: it poffefles, however, this advantage, that after 2 feale of comparifon is formed betwixt it and Wedgewood’s, in the manner defcribed in the explanation, the aflayer can at any time mark, with confiderable accuracy, the degree at which an experiment is effected, and compare it with the degrees of that feale; and if the furnace and apparatus are kept in proper repair, the refults will be confiftent with for- mer ones. Description of the FuRNAcE. AA (Plate V.} the pedeftal of brick-work on which the furnace is reared. B, the afh-pit. C, a view of the centraf parts of the grate, with a knee two inches deep and four inches fquare, for the purpofe of receiving a pedeftal of fire- clay for fupporting the crucible. DD, the feétion of an iron eylinder, which contains the brick-work, with flanges project- ‘ing inwards both at top and bottom: the upper flange con- tains two grooves for fliding the cover I, (made of caft iron;) and the under one projects {fo far as to form a fupport for the bars of the grate. EE, the lining of the furnace, compofed of fire bricks. F, the fire-place, three feet deep, ten inches diameter dt the grate, and diminifhing tonine inches at the top. G, the flue or draught- hole, which communicates with the chimney. H, the chimney (the top broken off to make it come into the plate}, which fhould never be lefs than 30 feet high, and nine inches fquare in the paflage. K, an oblong rectangular plate, which projects from the top of the cylinder for the purpofe of fupporting the pyrometer. LL, an iron box with a {quare bar of feel, which, in expanding, acts upon the lever at the diftance of one inch from the fulcrum. The letters of the horizontal and vertical fection refer. to the fame parts of the furnace. Descnrip-. Defeription of an Affay-furnace. 257 DescnripTIONn of the PYROMETER. The principle upon which this inftrument is conftructed is the expanfion of metal by heat. After feveral experiments with copper, iron, and fteel, I was induced to give the pre- ference to the latter. Copper was found to be too eafily fufed, and the fcale by that means lefs extenfive than was wifhed. Malleable iron, by being heated in this manner, frequently acquired permanent additional length, and paffed into the ftate of femi-fteel. This principle it derived from the contaét of the furrounding charcoal, introduced for the purpofe of preventing oxydation from taking place upon the furface of the bar. Highly cemented fteel, when expofed in this manner to the greateft heat, acquired no fenfible increafe of length: a bar of polifhed fteel was therefore adopted. A correfponds with the plate of iron K in the drawing of the furnace, on which the pyrometer is fupported. B an upright, on which is fufpended the lever. CC the lever, ten inches long from the fulcrum to the extremity, which aéts upon the fcale, and one inch on the other end from the fame point to a line drawn through the centre of the ex- panding bar. From this it is obvious, that if the fhort end of the lever be elevated half an inch by the expanfion of the bar of fteel, the other end will fuffer a depreffion ten times as much, or equal to five inches. Thefe I have divided into 50 degrees, (equal to each other on a tangent of the arch that forms the fcale DD,) fo that the moft minute expanfion in the bar will be vifibly indicated. Should the ratio of ten to one be thought too fmall, the power of the lever can eafily be increafed to 13 or 20, and the feale thus greatly enlarged. When the pyrometer is at reft, the index points at 0°, and its other extremity refts lightly upon the fharp point of the fieel bar. It is therefore requifite to make the lever nearly an exact balance, by forming its fhort end fufficiently weighty to overcome the great length of the other. The feale being carried the length of 50 degrees, allows the bar to expand Vor. IV, S §-10ths. 258 Defeription of an Affay-furnace. 5-10ths. This, however, will not be the cafe, though ex pofed to a degree of heat approaching to fufion. EE are two fupports for the feale, attached to the extremity of the plate by means of bolts. FF is a box of wrought iron which contains the bar of fteel exaétly fitted, with a fmall allowance for expanding in the thicknels, This box is in- - troduced into the lining of the furnace by means of fquare notches formed in the bricks about two inches from the contaét of the fire. The bottom of ‘the box relts tpon the under-flange of the cylinder, and its other end rifes through the building and iron-cover about two inches. When at firft introduced into its place, the fpace which may remain betwixt the outfide of the box and the building is carefully filled with fine charcoal duft, to prevent oxydation by the chance conta& of atmofpheric air. G is a polifhed bar of fteel 3 feet 2 3-4th inches long and 1-4th of an inch fquare, the fharp extremity of which aéts upon that part of the lever which, when at 0°, meafures one inch from the fulcrum. HH, a {mall box or cover, which fits upon the top of the iron box by means of pins. This is always kept full of char- coal-duft, to prevent the approach of external air, and the tranfmiffion of heat from within. This intrument may be ufed in conjunétion with Mr. Wedgewood’s {cale. Any given fubftance may be melted, and the degree marked upon the fcale: let this be compared with the degree of heat at which the fame fubftance melts by Wedgewood’s fcale; then let the greateft degree of heat of the furnace be meafured by one of Wedgewood’s rolls, and compared with that pointed out by the index, the one dif- ference divided by the other will give a fcale of comparifon, It will hardly efcape ihe notice of men of fcience, that circumftances may be fo varied, by the modes of charging the furnace, as to endanger an erroneous refult: but, if pro- per attention be paid, the affayer will foon underftand the trim of his furnace fo thoroughly as to be fure of always ebtaining fuch an accurate indication of the heat as cannot, 6 fail ‘ 4 d a Hinis for the Formation of a Theory of the Earth. 259 Fail to be of effential fervice to him. This faé I can atteft from experience. : If abfolute precifion be wanted, it may be obtained by employing three or more pyrometers, diftributed at regular diftances round the furnace, inftead of ufing only one. The ‘mean of the whole will be the true degree of heat in the furnace: VII. Agenda, or a Colleétion of Obfervations and Refearches the Refults of which may Jerve as the Foundation for a Theory of the Earth. By M. De, Saussure, [Continued from page 190. ] CHAP. xVirt, A. Odbfervations to be. made on Volcanoes at the Time of an Eruption, f I. de E form, dimenfions, and elevation of the crater. 2. The colour, elevation, and other fenfible qualities of the flames and the fmoke. 3. Phenomena which preceded the eruption, fubterranean noife, earthquakes, extraordinary movements of the fea. 4. Phenomena which accompany the eruption; as thun- der, lightning, pofitive or negative eleGtricity, fubterranean _ foife, earthquakes : feorie, athes, and ones thrown up; to What height and diftance. 5. Smell of the fmoke. In general it indicates the ful- phureous acid; but it may indicate alfo bitumen and coal. 6. Nature of the gafes which efcape during the eruption. 7. Velocity of the lava. Its degree of fluidity compared with the inclination of the ground over which it flows. 8. To meafure, if poftible, the degree of its heat when it iffues from the volcano. g- Whether the lava appears to be in a ftate of combuf- tion, or only incandefcence. S2 10. Whe- 260 Hints for the Formation of 10. Whether it does not cool more flowly, and according to other laws, than that of the bodies heated or melted in our furnaces. 10. A. Can it be fuppofed that the matter thrown up by volcanoes was not inflamed, or even in a ftate of incan- defcence, in the bowels of the earth; and that it is only the contact of the air which gives it thefe qualities ? 11. Whether the fudden cooling of Java in the air or in water divides it into prifmatic columns, fuch as thofe of bafaltes. 12. Whether it be true that fcoria newly thrown up, and fuddenly cooled by its rapid paflage through the air, feems covered with a bitummous varnifh. ) 13. And, in general, whether the mountain throws up bituminous matter or any thing that refembles the refiduum of the combuftion of coal, or whether it rather throws up pyrites or the refiduum of their decompofition. 14. To afcertain by obfervations, and even by experi- ments, whether it may not be poffible that pyrites or other ferruginous matters decompofed by water, undergo a fer- mentation, which, acting on grand mafles, may difengage a fufficient heat to produce the effects of a volcano. Pe OP whether, as M. Romme thinks, the fire of volea- noes is kept up by matters accumulated by rivers and cur- rents of the fea. 16. To fearch for means of afcertaining the depth of the focus of the volcano. 17. To examine whether, at the moment when an erup- tion begins to take place, there is any remarkable change in the tides, currents, fprings, and the neareft fpiracles and volcanoes. 18. Muddy eruptions: their height, bulk, nature of the water they contain; whether it be faline: nature of the earth and ftones thrown up; whether it contains fea fhells, of what kinds, and in what ftate. Watery eruptions: the fame re-. 5 fearches : a Theory of the Earth. 264 fearches: whether they hold in folution earths not ufually foluble in water *. B. Obfervations to be made at all Times on Volcanoes decidedly fuch. 19. Nature of the countries and mountains between which they are found. . 20. Hiftory of the volcano: its form, height, and extent in the moft ancient times; its fucceffive changes down to the prefent moment; its lateral mouths, and the epochs of their formation. . 21. Chronology and enumeration of its different erup- tions; defcription of them, and their mioft remarkable cha- racters. 22. To defcend, if poffible, into the craters of extinguifhed volcanoes; to meafure their depth; defcribe their far the nature of their fides, their ftrata, and the concretions ad- hering to them, fuch as fulphur, falt, &c. . 22. A. To obferve the fumaroles, or jets of fmoke, often acid, which arife; their temperature, their nature, and their effects on the ee with which they come in contact, 23. To examine the fiffures ; whether they contain me- tallic or ftoney cryftallifations, which may be confidered as fublimed, and formed by the cryftallifation of fubftances re- duced to the flate of {moke or vapour. 24, The nature of the flreams of cooled lava; their extent and thicknefs. 25. Whether it be true that, in general, they are porous both at the upper and lower furfaces of the ftrata, and com- pact in the interior part. 26. To ftudy the nature of the different currents placed above each other, in order to afcertain the difference that may have taken place in the focus of the volcano, and even in the fource of its lava. * To obferve thofe excavations from which confiderable currents of aic iffuc either periodically or conftantly. C. $3 24. Te 262 Hints for the Formation of 27. To examine, in general, in the lava, the nature of the earth and ‘tones of which it has been formed. a7. A. To ftudy the origin of the cryflals found inclofed in the lava, as the white garnets or leucites in that of Vefu- vius, in order to afcertain whether thefe cryftals have been formed in the lava fince the time of its fufion, or whether they pre-exifted i in the ftones from which the lava was pro- duced. 28. The nature and progrefs of the decompofition of the different kinds of Java, either by volcanic acids or meteors. 28. A. Whether there are any which have aCtually been in fufion, and yet have preferved all the external characters which the {tone had before it was fubjeéted to the action of the fubterranean fires. 29. The origin of volcanic afhes, pozzolanas, tarras, tufas, &c. 30. The origin of pumice ftones: whether they are gra- nites or feld-{pars, afbeftos, phrenites, deodalites, or potter’s clay more or lefs ferruginous, or; lafily, the remains of the decompofition of pit-coal. 30. A. Whether, as M. de Fichtel believes, the action of the fire of volcanoes may augment the fufibility of feld- fpar, and change it, in the fame manner as quartz, into real zeolite. 1. Nature of the obfidians or volcanic glafs : whether tHey be really glafs, and the refults of a complete fufion ; or whether they are not rather {tones of a vitreous appearance, and which have not been expofed to the action of a heat fufficiently ftrong to fufe them. 32. Whether there exift ancient kinds of lava, which, as related of thofe of Ifchia, are fufceptible of being heated b the moifture of rain and fogs, which would fupport the con- jeéture of No. 14. C. Obfervations to be made on Hills and Mountains which are doubted to have been really Vo{canoes. 33. The form, elevation, and other dimenfions of the hill | or a Theory of the Eartb. 2.63 or mountain, the volcanic origin of which may appear doubtful. 34. Situation of its ftrata. To afcend to the fummit of thofe which are inclined; to examine whether they have not a crater, or veltiges of one. 35. To obferve, above all, whether, in departing from the moft elevated point, there are found ftrata diverging in all parts, and proceeding from that point as a centre. . 36. To ftudy the characters of the ftones which have been expofed to the action of the fire, in order to diftinguifh them from other porous ftones, fuch as glandulous ftones or a- myedaloides. 37. When thefe characters are difcovered, to examine whether, in the neighbourhood of the doubtful: mountain, there are found fcattered {tones which exhibit the fame cha- ra¢ters, and which feem to have proceeded from that moun- tain, 38. To obferve whether there are found, in the neighbour- hood of the doubtful mountain, any vettige of the remains of heat concealed in the bofom of the earth, as of thermal, or even acidulous waters. It is well known that thefe figus are equivocal, but their combination with others may throw fome weight into the fcale. 38. A. Whether there exift certain proofs of alternate depofits of lava or other voleanic productions, and of matters accumulated or depofited by the fea. 39. Among the ftones changed by the fire, to difcover thofe which may be confidered as having been fubjected to the action of one ftratum of coal in deflagration, and which the celebrated Werner calls p/eudo-volcanic, and to diftin- guith them from thofe which have been fufed in a real volcano. 40. Bafaltes; their forms in columns, in beds, round mafles; their conne¢tions, the relation which the bafaltes of thefe different forms obferve with each other. 41. The nature of thefe bafaltes: that of their texture, ef the points which they contain, of the pores and empty 84 or 264 Hints for the Formation of.a Theory of the Earth. or full cells that may be obferved in them; of their different accidents and decompofition. 41. A. The phenomena they exhibit in the fire, aber expofed to, or fheltered from the aétion of the air.’ But before any arguments are drawn from thefe experiments, it will be neceflary to refolve the queftion, Whether it be true that a {tone may have been melted by fubterranean fire, and yet none of its characters exhibit thofe indications of fufion whirk the fire of our furnaces would have give en to the fame ftone. 42. Their connection, if there be any, with lava, fully af- certained as fuch: if it be true, for example, as M. Faujas affirms, that currents of lava are feen terminated by columns of bafaltes. 43. The nature of the bafes on which the bafaltes refts : whether, as M. Werner fays, any is found refting on wacke or hornftone, of an earthy and compaét fracture, which it- felf repofes on fand or freeftone. 44. Whether at other times bafaltes is feen to repofe on beds of coal (4oville) which prefent no indications of com- buftion. 45. In a word, to examine whether the foil which bears them, or the fides of the veins in which they are contained, prefent indications of the action of fire, or at leaft of having been expofed to the contaét of an incandefcent mafs; or, on the contrary, whether there appear indications of depofits of a fubftance which had been in a ftate of aqueous fluidity. 46. Whether there are in the bafaltes veftiges of organifed marine bodies or others; and in what ftate thefe veftiges are found. 47. Whether there are obferved, as M. Faujas fays, ba- faltes which feems to have formed a paflage for itfelf from top to bottom through maffes of granite. 48. In doubtful cafes of this kind it would be neceffary, were it poffible to be at the expence, to pufh a gallery under a rock of bafaltes, to examine whether the columns defcend below Inducements to ihe Eating of Human Fle/b. 265 below the foil which feems to carry them ; and if they are found below the foil, to fink a vertical well to afcertain the truth of the fyftems which fuppofe them to have been raifed from the interior parts of the earth through the upper ftrata, [ To be continued. ] VIII. Obfervations on the different Inducements to the Eating of Human Flefh. By J. pe Loureiro *, Vie firft inducement which can lead men to this excels is extreme hunger ; but however pardonable it may be under fuch circumftances, if the flefh ufed be that of dead bodies, it is highly deteftable on account of the confequences. During a dreadful famine in India, which deftroyed more than a _ hundred thoufand perfons, when the roads and ftreets were _ covered with dead bodies, becaufe people had not fufficient ftrength to inter them, I faw feveral have the refolution to _ preferve their lives by this difyufting food; but fome of them, though not many, found it fo delicious that when the famine ___ Was at an end they retained fuch an irrefiftible propenfity to human flefh that they lay in wait for the living in order to _ devour them. Befides others, there was a mountaineer who _ concealed himfelf in a foreft near the highway, where he ufed to caft a rope, with a noofe, over the heads of the paf- fengers, whom he afterwards cut to pieces to gratify his un- natural appetite. He had killed many perfons in this man- ner, but he was at Jength caught and executed. At the fame time, and owing to the fame caufe, a woman uled te go out for the exprefs purpofe of carrying away children who had ftrayed from their homes. She {topped up their nofe SO Ee Oe ee * The author of this paper is an eminent Portuguefe naturalift, A copy of it was given by the author from “his own manuf{cript, never pub- lithed, to Dr.G. H, Langfdorf, phyfician to Prince Chriftian of Waldeck at Lifbon, on the cth of January 1798, who tranflated it inte German, and - kent it to Profeffor Voigt of Jena. Sce his Magazin fiir den nucflen xufa fang der Naturkunde, Vol. I. part 3, aud 266 Inducements to the Eating of Human Ficfb. and mouth with clay that they might not call out for affift- ance, and by thefe means fuffocated them. . She conteffed . the fa& on being taken, and fome falted human flefh was found in her habitation. My fervant having entered it, obferved a girl of four or five years of age who had been fuffocated in the above manner, and who was lying wrapped up, half dead, ina mat. By employing proper means the was however reftored to life. -The reafon of the fecond inducement to anthropophagy will now be readily comprehended. We read in different works, both ancient and modern, that many nations, in varjous parts of the world, have killed men, not on account of famine, but of the delicious tafte of human fleth, which they not only fed upon but publicly fold. The third inducement, that people eat their deceafed 1 re= lations by way of fhewing them honour, feems to be as ro- mantic as it is repugnant to nature; yet there are many au- thors, from Herodotus, the father of hiftory, down to mo- dern times, who aflert that this practice has prevailed among various nations. A fourth incitement to eat human flefh is hatred and re- venge. There is a law in Cochinchina, that all rebels, when convicted of their crime, fhal!l be executed, and that their fieth fhall be devoured by the king’s loyal fubjects, and, in particular, by thofe who are nearett his perfon. At the time T refided in that country feveral executions of this kind took place. The men were beheaded, but the women were ftab- bed. Afier the execution the foldiers who guarded the pa- Jace flocked around the bodies, and each cutting off, with a pocket knife, a fmall piece, dipped it in the juice of an un- ripe lemon, and in that manner fwallowed it. But as the fize of the morfel is not determined by the law, and as moft of the people have an averfion to fuch food, many fuffer the bit of flefh to drop through their fingers and {wallow only the lemon. At the time when the Cochinefe were at war againft the ” { ' aa - Mais, a Defcription of an improved Eleétrometer. 267 _ Mois, 2 people who inhabit the mountains to the weft, and _ who often make incurfions into their territories, the Co-~ ‘chinefe general marched with an army towards the moun- tains ;, but as he was not able to get at the enemy, on ac- count of their inacceffible fituation, he ordered two prifoners he had taken to be put to death, and their flefh to be de- _ voured by his foldiers. In the year 1777, being on board an Englifh fhip of war in Turon harbour, in order to return from Cochin-china to ° Europe, a party arrived there who had joined a powerful ‘rebel named Nbae. This leader and his party had taken fome of the king’s confidential friends, and one in particular who had formerly done him a great deal of injury. The latter they put to death; and in order to gratify their re- venge, they tore out his liver and ate it. The Cochin-chi- nefe, in general, when violently incenfed againft any one, are accuftomed to exprefs a wifh ‘that they may be able te devour his liver or his flefh, IX. Defcription of an improved DiftharginBelcarometir Read before the Royal Society of Copenbigen. By A.W. Von Haucu, Marjbal of the Court, Sc. to bis Danifh Majely *. No branch of natural philofophy can boaft of having attracted fo much attention as the doétrine of eledtricity ; and indeed there are. few which feem more worthy of invefti- gation. When we confider the diftinguifhed part which elec- tricity apparently performs in the grand operations of na- ture; the aftonifhing, and, on the firft view, fo inexplicable effeéts produced by this power of nature fo different from thofe of any other, and its fecret and concealed mode of aétion, which the moft acute obfervers have not hitherto been able to penetrate, it will not feem furprifing that both * From the TranjaGions of the Royal Seciety of Copendagen. ¢ 268 Defeription of an improved Ele&trometer. the learned and the unlearned fhould, with unabated zeal, bave employed their attention on this phenomenon, as im- portant to fpeculative philofophy as it is by its influence in fociety. Without this inceflant attention our knowledge would not have made fuch rapid progrefs as it has done in the laft forty years; and there might have been little differ- ence between Otto von Guerick’s balls of fulphur, or Hau- fen’s glafs globes, which were feventy years later, and the electric machine now in the Teylerian Mufeum at Haerlem.. The former were fearcely fufficient to attraét the lighteft bodies, whereas the latter approaches near to nature in its ftrength, in its awful and wonderful effects; and feems to favour the poflibility of the idea, that there are natural powers capable of impelling heavy bodies with prodigious force; and which, conduéted by the hand of man, may, fome centuries hence, banifh the ufe of gunpowder, as the latter, a few centuries ago, banifhed bows and arrows. Franklin conveyed eleétricity from the atmofphere, loaded a battery with it, and direéted its mighty power with the fame eafe as that weak power excited by an eleétric machine. On account 6f the above-mentioned poffibility of exhibiting the eleétric power in a certain degree and of a certain ftrength, it was found more and more neceflary to have inftruments proper for afcertaining thefe, and by which it might be de- termined with precifion when and how a required effeét could be produced. . Though thefe inftruments have undergone many varia- tions and improvements, and though there is an effential difference between Stephen Gray’s or Du Fay’s threads and the electrometers of Achard and Brooks *, they are all to be confidered rather as announcers of ele¢tricity than as accu- rate gauges or meafures, as they are all incapable of fhewing its intenfity. Another inftrument, hitherto equally imper- * A defcription of thefe Eleétrometers may be feen in Adams's and Cayallo’s Treatifes of Eleéiricity, and in other works of the like kind. Ep1t, fed, Defeription of an improved Eleétrometer, 269 _ feé, though no lefs important in eleétric experiments, is 2 7 difcharging ele&trometer ; for, as it is believed that the laws _ of electricity can be defined with mathematical certainty *, it muft be of importance to be able to employ, with the fame certainty, the electric power which has been excited; and "every inftrument tending to promote this object, though fill imperfect, muft be of fome utility, and be not unacceptable to thofe fond of eleStrical experiments. All the difcharging _ ele&trometers hitherto known, perform their effect either by _ fpontaneoufly difcharging, as that of Lane, or as Henley’s general difcharger, &c. and in this cafe are affected by the "greater or lefs condu&ting property of the air, which muft neceffarily be changed on each change of the atmofphere, _ and therefore muft render the inftrument very imperfect and incorreét ; or the effect is produced by introducing a con- _ duéting body between two eleéric atmofpheres, and by thefe _ Means uniting them. But as this mutt depend on the greater _ or lefs dexterity of the perfon who performs the experiment to determine the proper moment for difcharging, and as an- other ele&trometer is at the fame time neceffary, this method q ' of difcharging is as uncertain as the firft. é I have endeavoured, therefore, to conftruét an inftrument _ to fupply this deficiency ; and I hope it will not be found _ unworthy of attention. It is an eleCtrometer which, though founded on the fame principles as that of Brooks, that is, _ on comparing the effect of the repulfive power of electricity ' between two bodies of a given fize with the known weight requifite to produce that effect, has, in my opinion, fome " improvements which are wanting in the other; for the ftate ate the baromettr has no influence upon this electrometer, as +4 has on that of Brooks; nor does friétion, which is far from being unimportant, here take place. But as this in- * SeeLord Stanhope’s Priaciples of Elediricity, 34, 4th, and sth parts ; and Covlomb’s defcription of an inftrument by which it is proved that the effect of the eleétric matter is in the inverfe ratio of the {quare of the dif- tance. ‘gaa fiyument 279 Defcription of an improved Elefrometers ftrument is intended to be ufed as a difcharging eleCtromtes ter, and muft be examined as fuch, no comparifon can pro perly be made between it and any of the other electrometers ' hitherto employed. ‘ Plate VI contains a reprefentation of the electrometer, and the different parts of which it confifts. OP is a board of dry mahogany, twelve inches in length and four in breadth, which ferves as a ftand for the inftruament. In this board are faftened two mafly glafs pillars, M and N, which fupport the two brafs capes Or rings GG, with the two forks of tempered fieel KK {crewed into them. The two rings GG are well covered with varnifh. In the ring G is faftened a brafs rod, which terminates ini a ball E of the fame metal, and an inch in diameter. The Jength of the rod and ball together is four inches and 4 half. A very delicate beam, AB, the arms of which are of un- equal Jength, moves on a fharp triangular axis (a knife edge) of well tempered fteel on the fork K of the pillar M. It is feventeen inches in length, and fo conftruéted that the fhort arm forms a third and the long one two-thirds of the whole beam. The fhort arm of brafs furnithed with the ball B, exaétly of the fame fize as the ball E, is divided into forty- five parts equivalent to grains. The long arm A is of glafs é covered with copal varnifh, and ends in an ivory ball A, inte which is fitted an ivory hook R, deftined to fupport the ivory - feale H. In order to render the infulation more completes this fcale is fufpended by three hairs. A very delicate beam, CD, eleven inches in length, moves on an axis, like the former, on the pillar N, though not here ~ fhewn. This beam is preportioned in the fame manners . ohe arm being a third and “the other two-thirds of the — whole length. The long arm of brafs is furnithed at the end with a ball D, and divided into thirty parts correfpond- — ing to grains. The fhort arm of glafs terminates in a long — roundifh plate C, covered with copal varnifh, The ftech forks Defeription of an improved Eleétrometer. 29% forks are fhewn by the feétions of the two brafs caps FF, as are alfo the two knife edges LL. By thefe caps the efcape of the electric matter is partly prevented. A brafs ring Q, capable of being moved along the fhort arm of the upper beam AB, fhews, by means of marks de- termined by trial and cut out on the beam, the number of grains which muft be placed in the fimall feale to reftore the equilibrium of the beam-at each diftance of the ring Q frona the point of fufpenfion. On the long arm CD of the lower beam there ts alfo a moveable ring S, which, like the ring Q, fhews in grains, by its diftance from the point of fufpenfion, the power re- quifite to overcome the preponderance of LD in regard to LC. The power neceffary for this purpofe will be found if the ; fhell H, which weighs exactly fourteen grains, be fuffered to fink down on the glafs plate C, and the ring S be pufhed . forwards till both the arms of the beam are in equilibrium. The part of the beam on which the ring S has moved is di- vided into fourteen parts, fo that o marks the place where the ring S muft ftand when the beam, in its free fate, is in equilibrium; and x4 ftands at the place where the ring § again reftores a perfect equilibrium when the fhell H is laid on the elafs plate C. Each of thefe parts, which are diyided into quarters, indicates a grain. The lower divifions of the feale will be found with more accuracy if quarters of a grain be put, in fucceffion, into the fhell H (after it has been laid on the plate C), and the ring S be moved between each quarter of a grain until the perfect equilibrium be re- ftored. This place on the beam is then to be marked, and you may continue in this manner until the goth part of a grain be given. Both feales, for the fake of diftin€tnefs, are divided only fo low as quarters of a grain; though the inftru- ment is fo delicate, and muft abfolutely be fo, that 1-20th of a grain is fufficient to deftroy the equilibrium. The two glafs pillars M and N, together with the fteel ' forks 272 Defeription of an improved Eletrometer. forks affixed to them, are fo fitted into the ftand that both the beams lie parallel to each other as well as to the rod GE. In this pofition of the beams AB, the balls B and E are juft im conta&. The fmalleft glafs pillar N is of fuch a height that the ball of the beam CD ftands at the diftance of ex- adtly four lines from the ring G, and cannot move without touching the latter, The fmall fhell H is fufpended in fuch # manner that there is a diftance of exactly two lines between it and the fhell C. In each of the brafs rings GG is a fmalh hole, that the inftrument may be conneéted with the two fidés of an electric jar. [is a brafs wire, with a hollow bit of ivory a deftined to fupport the beam CD, which is necef- farily preponderant at D, in order to prevent ofcillation be- tween the difcharges to be examined by the inftrument. Jt may be readily comprehended that, when the beam AB has moved, A mutt pafs over twice the fpace that B does; and that; in the beam CD, the cafe is the fame in regard ta Cand D. If AB therefore be connected with the external fide, and CD with the internal fide of a battery, but in fuch a manner that the inftrument is at a fufficient diftance be- yond the electric atmofphere ; and if the battery be charged,” the repulfive effect of the electric power will oblige the ball B to feparate from the ball E; the fhell H muft therefore naturally fink down with double velocity, fo that when the ball B rifes a line, the fhell H mutt fink two: when it reaches this depth it will touch the fhell C, and the latter, by the power excited in it, will be obliged to fink, by which . D muft naturally again afcend in a‘double proportion to the finking of C; fo that when C has fallen two lines, D mutt have afcended four, and D that moment touches the ring by which the two fides of the battery are connected with each other, and difcharges the battery. . But, as the attractive eleétric power between unlike. at-— -mofpheres, under like circumflances, is at leaft as ftrong as its repulfive power between like atmofpheres, it would thence follow that the electric power, inftead of repelling the ball B Defcription of an improved Ele&rometer. 295 from the ball E would rather attraét D, and, by its contact with G, promote the difcharging ; by which the inftrument would fail of its object, and be fubjeéted to the temperature of the atmofphere like all other eleCtrometers ; and befides this, the electric power could no longer be determined by weight. To obviate this inconve ehience, the inftrument, in all eleGtrical experiments, muft be applied in fuch a manner that the power with which the ball D is attracted by AB may exceed in ftrength the power required to repel the ball B from the ball E. For this purpofe the ring S muft always be removed two divifions farther on CD, towards D, than the ring Q is fhifted on AB towards B. If, for example, an electric force were required equal to eight grains, according to this electrometer, the ring Q muft be removed to the place where 8 ftands, and the ring S to the place marked 10. ‘The repulfive power will then naturally repel the balls B and E before G is in a condition to attract the ball D, as a power of two grains would be neceffary for this purpofe, befides that of the eight already in action. The fhell H, w ‘ith its w eight of Sostonn grains, will eafily overcome the preponderance of LD over LC, as it amounts only to ten grains, and there+ fore nothing exifts that can impede.the difcharging. When the ring S, according to the required power, is removed fo far towards D that the fhell H is not abie by its weight to deftroy the preponderance of LD in regard to LC, the aétive power of the fhell H muft be fo far in- ereafed by the addition of weights that, it can at, with a preponderance of four grains, on the plate C. If, for example, an electric power of fourteen grains be required, the ring S mutft be removed to 16, by which LD refts upon a, with a preponderance of fixteen grains in regard to LC. Now to make H a& on the plate C with a preponderance of four grains, it muft be increafed to twenty - grains, that is, fix grains weight more mutt be added, as it weighs only fourteen; which fix grains are again laid upon LB; and therefore the ring Q is fhifted to 20, as the Vou, IV, és firength 274 Defcription of an improved Eleétrometer. ftrength of the repulfive power is pointed out by fourteen grains. If an eleétric power of twenty-five grains be required, the ring S muft be removed to 27, and the weight of feventeen grains be put into the fhell H in order to produce a pre- ponderance of four grains in regard to S. Thefe feventeen grains are added to the required power of twenty-five grains, and the ring @ is pufhed to 42, &c. In this manner the repuifive power always a¢ts before the attractive power can. It may be readily perceived that the faults and inconve- niences common to all the elestrometers hitherto employed, and which have been already mentioned, cannot take place here; becaufe the difcharging is performed by immediate conneétion between the pofitive and negative eleétricity in the inftrument itfelf, without any external means being employed. One of the moft effential advantages of this inftrument is, the certainty with which the fame refult may be expected when the experiment is repeated. For the fame degree of electric power, whatever be the temperature of the atmo- {phere, will always be neceflary to commence the feparation of the two balls B and E from each other, the quantity of _ coated glafs and the diftance of the ring Q from the axis L - being the fame. Another no lefs important advantage of this inftrument~ is, that in an experiment where the fame electric power, often repeated, is neceflary to afcertain the refult with aceu- racy; fuch, for example, as the charging a battery through acids, water, &c.; the fame degree of precaution is not ne- ceffary as is indifpenfibly fo in any other eleGtrometer, as the perfon who puts the machine in motion has nothing to do but to count how often the electrometer difcharges itfelf; and the inftrument may be inclofed in a glafs cafe, or prevented in any other manner from external contact, or any other cir- cumftances which might render the experiment uncertain. : | flatter On the Tones produced by an Organ-pipe, &ce. 275 I flatter myfelf that the fimplicity of the conftruGtion of this inftrument, the facility with which it may be made at a very {mall expence, and the certainty that two inftruments, prepared according to the fame feale, with a like quantity of coated glafs, muft exaétly correfpond with each other; but, above all, that the certainty and accuracy by which experi- ments may be made with it,’ and by thefe means be accu- rately defcribed, are advantages which will not be found united in any of the electrometers hitherto invented. X. Obfervations on the Tones produced by an Organ-pipe in different Kinds of Gas. By C.F. F. Cutapni*. Air, it is well known, is the moft common conduétor of found; but it can become a fonorous body alfo. The latter is the cafe in regard to a pipe, as the pipe itfelf does not emit found, but the column of air included in it, and which, being feparated from the reft of the atmofphere, is obliged, by blowing, to vibrate in fuch a manner that it con- traéts and expands longitudinally in various ways ; and thefe vibrations are then conduéted to a diftance by the furround- ing air. Jt is not neceflary that I fhould here farther ex- plain the different kinds of vibration of which the air in a pipe is fufceptible. Thofe who are defirous of information on this fubjeét may confult Daniel Bernoulli’s papers in the Memoirs of the Academy of Paris for 1762; thofe of Lam- bert, in the Memoirs of the Academy of Berlin-for 1775 ; and of Euler, in the Sixteenth Volume of the New Tranfac- tions of the Imperial Academy of Peterfburgh. The conduéting of found through the air, and the vibra- tions of air in a pipe, depend on the fame laws. This will readily appear from the following obfervation, befides others, that the velocity of the vibrations, under like circumftances, * From Poig:'s Magazin fir den neueflen xuftand der Naturkunde, Vo}. J. part 3. T2 depends 476 On the Tones produced by an Organ-pipe depends merely on the length of the pipe, and not on its di- ‘ameter; fo that the velocity is not changed when the pipe is indefinitely enlarged, or, what is the fame thing, when it is totally removed, fo as to afford free accefs to the air on all fides. Sound therefore is diffufed through a certain {pace of 7 air, im the fame time in which a column of air inclofed in a pipe makes one vibration; a propofition which has been proved in the before-mentioned papers of Euler, Bernoulli, and Lambert, and alfo by Count Giordano Riccati in his Treatife on Elafic Fibres or Strings, and which is confirmed by experience. Hence it follows, that the number of the vibrations made by the air in a pipe may be found, if the real velocity with which found is conduéted through the air be divided by the length of the column of air contained in the pipe. The labours undertaken by Newton, Euler, Daniel Ber- noulli, Lambert, Giordano Riccati, and others, to deter- mine, from general mechanical principles, the velocity with which found is conduéted, have given no other refults than thofe taught by experience. By all thefe theoretic re- fearches the fpace through which found paffes in the air, or, in general, in any expanfible fluid fubftance, was found to be* 2 as where ¢ is the fpace through which a heavy body falls in a fecond, or in any given time; a the elaflicity of the expanfible fluid, which is affumed equal to the pref- fure it fuftains from the atmofphere; and 4 the denfity of the expanfible fluid: a may be alfo the height of the baro- meter, if the denfity of the mercury be confidered as 1. Theory gives, therefore, about goo Parifian feet asthe dif- tance to which found is tranfmitted through the air in the courfe of a fecond; whereas this fpace has been: found, by _experience, to be equal to about 1938. No one has ever yet affigned a fufficient reafon for this difference. The moft common conjeéture is, that it mutt be owing to a mixture of various foreign particles; but this, by thofe acquainted — with ~ in different Kinds of Gas. ay? with the nature of atmofpheric air and the different kinds of gafes, as afcertained by chemical experiments, can hardly be admitted, and is contradi&ted by this circumftance: that, according to every obfervation, the ftate of the air, whether moift or dry, cloudy or rainy, does not alter, or at leaft in a fenfible manner, the velocity with which found is‘conduéted. Various other conjeétures feem to be equally inconfiftent with nature. From the prefent experiments it follows, in my opi- nion, that the velocity of the vibrations of an expanfible fluid fubftance cannot be determined by the mechanical princi- ples hitherto admitted alone; but that it depends, befides _thefe, upon other properties. Were the before-mentioned data fufficient to determine the vibrations of an expanfible fluid, the tone which a pipe can emit, both in the air and in different kinds of gafés, under like cireumftances, would be inyerfely as the fquare root of the fpecific gravity of the expanfible fluids. The refult given by the prefent experiments is, however, different. As I was not furnifhed with the apparatus proper for the purpofe, I requefted, during my refidence at Vienna, profeffor Jacquin junior, who has a great zeal for the progrefs of fcience, to undertake the experiments; and he was {fo good as to comply with my wifhes. The apparatus confifted of an open tin.organ-pipe, in which the length of the vibrating column of air from the aperture where the inflated air iffues to the end was about fix inches, having its upper end inferted in the neck of a bell-glafs, that could be clofely fhut by means of a cock. On immerfing the bell in water, the pipe was at the fame time filled with it, to guard againtt all mixture of atmo- fpheric air. A bladder, furniffied alfo with a cock, was {crewed upon the neck of the bell, after having been com- prefled. as much as poffible, and emptied of air by applying the mouth to it. The bell and the bladder were then filled with fuch a quantity of the air to be examined, that the water, in which the bell was immerfed, ftood at an equal. T3 height 278 On the Tones produced by an Organ-pipe height both in the infide and outfide; and the preffure ful tained by the bell was equal, therefore, to the preflure of the atmofphere. The pipe was blown by compreffing the blad- der; but the greateft caution was neceflary te prevent the pipe from emitting, inftead of its natural tone, any of its higher tones, which in an open pipe, as is well known, are as the natural feries of the numbers, that is, in arithmetical progreffion. A weak and uniform preffure was therefore ne- ceflary, but which could be repeated at pleafure; becaufe, when the preffure was omitted, the fuperfluous gas returned back into the bladder. The temperature, which certainly contributes in fome degree to vary the tone of a wind inftru- ment, in regard to all the different kinds of gas, was always the fame; that is, the degree which is ufual on a fomewhat cool morning in fpring, To enable me to judge with more accuracy of the tone, I had tuned two ftrings to an unifon of that tone produced in common air: the experiments were made with the utmoft accuracy, fo that I have reafon ta think there was no room left for the fmalleft deception. The bell and the pipe being firft filled with common air, the tone was exaCtly the fame as that of a pipe blown when it is perfectly free; but much weaker, as muft have been expected, becaufe the vibrations of the air inclofed in the bell were propagated, and could be communicated to the furrounding atmofphere only through the fides of the bell and through the water. But though the found, for the fame reafon, was fomewhat weak in the other experiments, they could, however, be heard very diftinétly. In oxygen gas from manganefe the found was half a tone -or nearly a whole tone lower than in common air. This nearly agrees with theory 5 according to which the difference muft amount to almoft half a tone, if the gravity of atmofpheric air be to that of oxygen gas as 1 to 1‘103, and the tone in- yerfely ‘as the fquare root of the gravity. The moft ftriking deviation from theory was exh by azotic gas. Galt Bish have been expected that the found of it in different Kinds of Gas. 279 it would have been a little higher than that of common air, becaufe it is fomewhat lighter, and becaufe its gravity is to that of atmofpheric air as 0-985 to 1; but it was half a tone lower. Three kinds of azotic gas were tried; one produced bymeans of liver of fulphur, another by a mixture of iron and fulphur, and the third from common air by means of nitrous gas, . In all the three a taper was extinguifhed in a moment, and they all gave the fame tone. Should it be here fuf- pected that the azotic gas difengaged from atmofpheric air by fulpbur and iron, might have had a mixture of hy- drogen gas, the tone in that cafe mut have been raifed.rather than lowered by the latter on account of its lightnefs. We may therefore confider it as certain, that the vibrations of azotic gas, let it be prepared in whatever manner it may, are much flower than the vibrations of atmofpheric air; and that the difference amounts to about half a tone. It is re- markable that azotic gas in particular fhould exhibit, in re- gard to its vibrations, fuch a variation from the common theory, as, according to late experiments, it differs fo much from other kinds of gafes in regard to its expanfibility at dif. ferent degrees of heat. It would be well worth the trouble to repeat thefe experiments, refpecting the vibrations of azotic gas, at different high and low degrees of temperature. It ought alfo to be examined with more accuracy, whether Marriot’s law, that at the fame temperature the denfity of an expanfible fluid increafes and decreafes in proportion to its preffure, may not admit of fome exception in regard to azotic gas; as this inquiry would, in all probability, enable us to explain the variation of its yibrations from the com- mon theory, A very remarkable phenomenon was exhibited by a mix. ture of azotic and oxygen gas. It might have been fup- pofed, that azotic gas, being a lighter fubftance, would have eccafioned a higher tone than atmofpheric air; and oxygen T 4 gas, 280 On the Tones produced by an Organ-pipe gas, as a heavier fubftance, a lower tone; and that a mix ture of thefe two would have given a mean tone between both. Experience, however,. fhews that each of thefe two expanfible fluids, as I have.already faid, gives a higher tone than atmofpheric air; and that a mixture of them gives a tone higher than either of thefe can give alone, and per- fectly fimilar to the tone of atmofpheric air. The quantity of oxygen gas mixed with the azotic gas might, according . to'appearance, be at firft about a fourth; afterwards a third; or fomewhat more; which however made no confiderable variation in the tone. I am of opinion, therefore, that the unknown caufe which occafions a mixture of thefe two fub- ffances to vibrate quicker than each of them taken fingly, may alfo occafion found to be conduéted with greater velo- city than it ought, according to common theory, through atmofpheric air, which bas the fame component parts as the above mixture. This greater velocity feems to imply rather a chemical than a merely mechanical mixture of thefe fluids. But this is contradiated, befides other obfervations, by one in particular of that acute and diligent philofopher Profeffor Remigius Dottler of Vienna, who fuffered common air to and above a year untouched in a glafs tube five feet in length and one and a half in diameter, which was well flopped both at top and bottom, and at the end of that time the component parts of the air were in fome meafure fepa- rated from each other according to their fpecific gravity; fo that a lighted taper was extinguifhed in the lighter azot found at the top, while another burnt m the heavy oxygen gas at the bottom with more ftrength than in atmofpheric air. Hydregen gas gave a far higher tone than atmofpheric air; with that extricated by iron and the fulphuric acid, the difference was about an octave; with that by zinc and the muriatic acid, it was nearly an o€tave and a whole tone; by that from the fleam of water conduéted through a tube of ignited iron, it was fomewhat above an octave and a {mall third, — in different Kinds of Gas. 281. third. This difference, however, is not fo great as might have been expected from fo light a gas, the gravity of which is to that of common air, when the gas is perfectly pure, as 0°084 to 1. Had the tones, therefore, been inverfely as the {quare roots of the gravity, the tone with hydrogen gas from iron and the fulphuric acid, allowing it to have been only fix or feven times lighter than atmofpheric air, mutt have been about an oétave and a large third higher; and by the lighter hydrogen gas, about an octave and a {mall feventh higher. “By mixing atmofpheric air with hydrogen gas, the tone, as might readily be expected, was lowered ; but it is to be remarked, that as long as thefe two fluids were not uni- formly mixed by filling and comprefling the bladder, a dif- cordant noife only was heard, and not a diftinét found, as the vibrations could not be ifochronous, which forms the only effential difference between a diftin® found. and fuch a difcordant noife. The fame thing was obferved.in regard to the b€fore-mentioned mixture of azotic and oxygen gas. The tone of carbonic acid gas from chalk and the ful- phuric acid was almoft a large third lower than the tone of atmofpheric air; which agrees pretty well with theory, fince the gravity of thefe fluids is as 1°5 to 1. Nitrous gas from nitrous acid and copper was not very favourable to found; and it required a {trong preffure of the bladder and a great deal of caution, becaule, inftead of the wifhed-for low tone, one of the higher tones was produced, The loweft tone, obtained with confiderable dificulty, was about half a tone lower than in atmofpheric air; which agrees alfo pretty well with theory, fince this gas is heavier, and the gravities are as 1°195 to 1: the tone was alfo almoft like that in. azotic gas, notwithftanding the confiderable differ- ence in the eravities of thefe two fluids. As to the velocity with which the found of another elaftic body would be conduéted through thefe gafes, could a fufli- cient extent of them be procured to make the obfervation, it follows, from what has been faid in the beginning of this paper, ‘ (282 © Onthe Tones produced by an Organ-pipe, &c. paper, that with equal preffure they would be in the ratie of the tones above mentioned. The prefent experiments are very different from thofe of Prieftley and Perolle on found in different kinds of gafes. The experiments of thefe two philofophers had relation only to the intenfity with which the vibrations of another elaftic body (of a bell {truck by a hammer) are conducted through thefe gafes. Perolle contradicts Prieftley’s affertion, that the power of conducting is as the denfities; but to this rule Prieftley himfelf makes an exception in regard to oxygen gas, which appears to be a ftronger conductor: azotic gas was examined by neither of thefe philofophers. In hydro- gen gas they both found the conduéting power very weak, which is no doubt owing to its little denfity, In oxygen gas they found the found fomewhat ftronger than in com- mon air; in the nitrous gas Perolle found it alfo fomewhat ftronger. In carbonic acid gas Prieftley found the found | ftronger; but Perolle, weaker, duller, and fomewhatlower than in common air: which laft circumftance I confider as agreeable to truth, becaufe the vibrations of a founding body mu{t be more retarded the denfer the furrounding fluid is, or according to its greater preflure on that hody. For this reafon the vibrations of a body vibrating in our atmofpheric . air muft be a little flower than they would be in a vacuum; as experience teaches that the found of a bell becomes lower the more it is filled with water, or the de€per it is immerfed in that fluid; fo that, when it is ftruck at a confiderable depth, it no longer emits a diftin@ found, but rather a kind of difcordant noife. XI. Letter eet [ 283 XI. Letter from E. Penoxure of the Academy of Turin, formerly Profeffor of Anatomy and the PraGice of Medicine at Touloufe, to J.C. DE LA METHERIE, on the Acoujlic Experiments of CHLADNI*. I ReaD in your Journal of Meffidor, 6th year, and in the Bulletin des Sciences, publithed by the Philomatic Society of Pluviofe the fame year, a fhort account of the experiments made by Chladni and Jacquin at Vienna, with a view to determine the fonorous properties of various gafcous fub- ftances. By caufing a fmall tin pipe, brought inte conta& with a cock in the neck of a bell glafs, to be blown by gas contained in a bladder applied to the external aperture of the cock, thefe philofophers obferved, that the found was a femi- tone lower with azotic and oxygen gas than with atmofpherie air; a third lower with carbonic acid gas; and nearly the fame with nitrous gas: but, with oxygen gas, from nine to eleven tones higher than with the air that furrounds us. A mixture of azote and oxygen, in the fame proportions as in atmofpheric air, gave the fame tone as the latter; but when the mixture of thefe gafes was not uniform, the founds were totally difcordant. The fingularity of thefe refults induced mé to examine the experiments with attention. Prieftley +, feveral years ago, publifhed fome obfervations . on the fame fubject; but he had made ufe of a metallic body rendered {onorous by percuffion, after he had fixed it in a glafs jar, which he filled fucceffively with different kinds of gas. The aériform fubftances which he employed for his experiments appeared to him to propagate founds in proportion to their denfity : he remarked, that in hydrogen gas the found feemed like that produced in a vacuum or air highly rarefied. Is it to be fuppofed that fuch a philofopher as Prieftley would have failed to difcoyver the alteration of tones produced in the va- * From the Yournal de Phyfique, an. 7. t See Obfrvations and Experiments on different Branches of Philofophy, Part Ill. p. 355.—Prieftley made no experiments with nitrous gas. rious 284 On the Acouftic Experiments rious aériform {ubftances? His ear would certainly have dif- tinguifhed the falling of a third in the carbonic acid and ni- trous gafes; and he muft, no doubt, have been ftruck with the prodigious rife occafioned by the hydrogen, At the time Prieftley made his experiments I was engaged in fome of the fame kind, the refults of which were publifhed in the Memoirs of the Academy of Sciences of Turin for the _ years 1786 and 1787. In my paper it may be feen that | fucceffively filled a bottle, and inverted it in a pneumato-che- mical preparation of various aériform fubftances; and in thefe atmofpheres I rung a fmal] bell, and made a repeating- watch ftrike. As the founds reached my ear, I paid atten- tion to the variations they exhibited in regard to the tone, its intenfity, and the vibration. To affift my ear I made ufe of a violin, Some idea may be formed of the refult of my labours, by cafting an eye over the firft table of my memoir, of which the following is a copy +— RT DE TA eT a Nature of the Tage of te Nature or Spe- Diftan Ege 7 of Sounds in dif- |". 5 which they may Gafes examined. ‘fe cies of the Sound. Serent Airs. be beard. 1, Atmofpheric air fervingfor a point of comparifon, 2. Fixed air, drawn from Alike, or a lit- tle lower than} Confiderably ee aa in the preceding duller. gascet een aed experiment. 3. Vital air ex- tracted from red precipi- tate, 4. Nitrous air produced , by|Nearly like the Ditto Ditto a’ nitrous fo-/former. ; ; Jution of tin, 5. inflammable Seemed a httle'Clearer than in {harper than in| atmofpheric 63 feet. common air. air. Not very dif- ‘air produced Had no harmo- by the action tinét: it feemed, ny, nofirength; f diluted yi- father a weak aad Gégied to 11 feet. payee ife than . “die away at proper tone. | fieel filings. 4 of Chladni and Facquin. 2385 Chladni’s experiments, therefore, feem to contradic thofe made by Prieftley and myfelf. To reconcile them, it will no doubt be faid that Chladni and Jacquin employed a wind-inftrument, and that my experiments and thofe of Priefiley were made with metallic bodies rendered fonorous by percuffion. But whence does it happen that thofe fluids, fome of which lower the found of a pipe one-third, while another makes the found of the fame pipe from nine to eleven tones higher, have not power to alter the tones of a metallic body in any fenfible degree? I fhall here offer a few remarks which feem to arife from thefe genera] obfervations. Ina mixture of oxygen and azote, in the fame proportions as in the atmofpheric air, found is the fame, according to Chladni and Jacquin, as in the latter medium; but they add, if the mixture of thefe two gafes is not complete, the found is quite difcordant.. What! do oxygen and azote af- ford each of them the fame found? and does an incomplete mixture of them produce a difcordant found? It will no doubt be replied, that azote and oxygen do not give the fame tone as atmofpheric air; but, in theatres, ball-rooms, con- cert-rooms, &c. where a great number of fpectators are affembled, and where there is a fufficient quantity of car- bonic acid, which does not combine with the air of the atmofphere, has it ever been obferved that wind inftru- ments were difcordant? If an incomplete mixture of at- mofpheric air with gas, which lowers the found one third, does not render the founds difcordant, how can we perfuade _ ourfelves that a mixture of two gafes, which caufe a falling of only half atone, fhould occafion a found altogether difcord- ant, merely becaufe the portions of the gafes are completely mixed, while the admixture of fome other particles is much, lefs. complete ? The above authors inform us alfo, that in hydrogen gas the found rifes nine or cleyen tones. Here there can be no medium. Either the found produced in the hydrogen is fharper by nine tones, and in that cafe the elevation ought 8 not’ 286 On the Acouftic Experiments of Chladni. not to be carried to eleven; or the found is {harper by eleven tones in the hydrogen than in atmofpheric air, and then it is wrong to fay that it rifes only nine tones. This want of correctnefs and precifioti in determining th tone; this great latitude allowed to the hydrogen, of being able to raife the found nine or eleven tones; does it not prove an indecifion, an uncertainty on the part of thefe phi- lofophers, little calculated-to procure confidence to their experiments ? Let it not, however, be imagined, that I with to conteft the reality of their difcoveries. Not having repeated the ex- periments of thefe authors, I can have no fuch intention. I have only endeavoured to give an account of thofe doubts which remained on my mind after I had taken the fubje& into confideration, and to engage the philofophers to re- move the uncertainty by repeating the experiments. One of thefe authors, Chladni, has made an obfervation which feems entirely his own. He obferved, that when a plate of glafs is agitated by means of a bow, if fome duft is ftrewed over the glafs, the former will appear to have ar- ranged itfelf fymmetrically, after the plate ceafes to emit found. Under the like cireumftances the figures are always the fame. It is not at all furprifing, that an elaftic body, when put in motion by the fame means, fhould conftantly experience: effects of the fame kind. The light body placed on the fur- face of the glafs with which the experiment is made, only confirms what we were already taught by reafon. But be- fore it be concluded that thefe motions produce found, or tend to determine the tone, philofophers are invited to read my Letter to De la Metherie On the Total Vibrations of Sonorous Bodies, publifhed in the Journal de Phyfique for’ December 1785. This letter, the fenfe of which is altered by fome typographical errors *, contains facts a little too precife ” * P. 424, at the end of the firft line, add acyautcx ; fame page, at shi beginning of the 11th line, for fox vead son; next line, for ‘anieau “read @rcéake perhaps, - 7 Submarine Foreft on the Eaft Coaff of England. 287 perhaps, but which do not appear to me the lefs to merit - the attention of the learned. -Philofophers, in my opinion, will find fome curious obfer- vations on this fubject alfo in my Inquiries into the Propa- gation of Sound in different Solid as well as Fluid Mediums ; which will foon appear. ‘XII. On a Submarine Foreft on the Eaft Coaft of England. By JoserpuH Correa DE Serra, LL.D. F.R.S. and A.S.* In Geology, more perhaps than in any other branch of Natural Hiftory, there exifts a neceflity of ftrictly feparating the faéts obferved from the ideas which, in order to explain them, may occur to the mind of the obferver. In the pre- fent ftate of the feience, every well afcertained fact increafes our ftiJl narrow ftock of real knowledge; when on the contrary, the reafonings we are enabled to make are at beft but ingenious gueffes, which too often bias and miflead the judgement. I fhall, therefore, endeavour in this paper to give, firft, a mere defcription of the object unmixed with any fy{tematical ideas, and fhall afterwards offer fuch con- jectures on its caufes as feem to me to be fairly grounded on obfervation. Jt was a common report in Lincolnfhire, that a large ex- tent of iflets of moor fituated along its coaft, and vifible only in the loweft ebbs of the year, was chiefly compofed of decayed trees. Thefe iflets are marked in Mitchell’s chart of that coaft by the name of clay buts; and the village of Huttoft, oppofite to which theysprincipally lie, feems to have _ derived its name from them. the month of September 1796 I went to Sutton, on the coaft of Lincolnfhire, in the company of the Right Hon. the Prefident of the Royal Society, in order to examine their nature and extent. The * Frem the Philofophical Tranfaétions, 1799. 6 roth 253. - On @ Submarine Foret 1gth of the month, being the firft day after the aieacal full moon, when the beck ebbs were to be expected, we went ina boat about half paft twelve at noon, and foon fet foot _ upon one of the largeft iflands then appearing. Its expofed furface was about thirty yards long, and twenty-five wide, when the tide was at the loweft. A great number of fmaller iflets were vifible around us, chiefly to the eaftward and fouthward; and the fifhermen, whofe authority in this point is very competent, fay, that fimilar moors are to be found along the whole coaft, from Skegnefs to Grimfby, particu- larly off Addelthorpe and Mablethorpe. The channels di- viding the iflets were, at the time we faw them, wide, and of various depths; the iflands themfelves ranging generally | from eal to weft in their largeft dimenfions. We vifited them again in the ebbs of the 20th and aft; and though it did not generally ebb fo far as we expected, we could notwithftanding afcertain that they confifted al- moft entirely of roots, trunks, branches and leaves of trees and fhrubs, intermixed with fome leaves of aquatic plants. The remains of fome of thefe trees were ftill ftanding on their roots, while the trunks of the great part lay fcattered on the ground in-every poffible direétion. The barks of trees and roots appeared generally as frefh as when they were grow- ing; in that of the branches particularly, of which a great quantity was found, even the thin filver membranes of the outer fkin were difcernible. The timber of all kinds, on the- contrary, was decompofed, and foft in the greateft part of the trees: in fome, however, it was firm, efpecially in the roots. ‘The people of the country have often found among them very found pieces of timber, fit to be employed a feveral economic: al pur pofes. The forts of wood which i diftinguifhable, are, birch, fir, and oak. Other woods evidently exift in thefe iflets, of fome of which we found the leaves in the foil; but our prefent knowledge of the comparative anatomy of pray is not fo far advanced as to afford us the means of pronouncing with on ihe Baft Coaft of England. 289 with confidence refpe&ting their fpecies. In general the. trunks, branches; and roots of the decayed trees were confi~ derably flattened; which is 4 phenomenon obferved in the furtarbrand, ot foffil wood of Iceland, and which Scheuchzer remarked alfo in the foffil wood found in, the neighbourhood of the lake of Thun in Switzerland. The foil to which the trées are affixed; arid in which they grew, is a foft greafy clay; but for many inches above its furface, the foil is entirely compofed of rotten leaves fcarcely diftinguifhable to the eye, miany of which may be feparated by putting the foil in water, and dexteroufly and patiently ufing a fpatula or blunt knife. _ By this method I obtained fome perfect leaves of Ilex aquifolium, which are now in the herbarium of the Right Honourable Sir Jofeph Banks; and fome other leaves, which, though lefs perfect, feem to belong to fome fpecies of willow. In this ftratum of rotten leaves we could alfo diftinguith fome roots of Arundo phrag mites: Thefe iflets, according to the moft accurate information, extend at leaft twelve miles in length, and about a mile in breadth, oppofite to Sutton fhore. The water without them, towards the fea, generally deepens fuddenly, fo as to form a fteep bank. The channels between the feveral iflets, when the iflets are dry, in the loweft ebbs of the year are from four to twelve feet deep: their bottoms are clay or fand, and their diréétion is generally from eaft to weft. A well, dug at Sutton by Jofhua Searby, fhows that a moor of the fame nature is found tinder ground in that part of the country at the depth of fixteen feet, confequently very nearly on the fame level with that which conftitutes the iflets. The difpofition of the firata was found to be nearly as follows: Clay, 16 feet—Moor, fimilar to that of the iflets, 3 to 4 ditto—Soft moor, like the feowerings of a ditch bottom, mixed with fhells and filt, 20 feet— Marly clay, 1 foot—Chalky rock, from 1 to 2 feet-—Clay, 3t yards—Gravel and water; the water has a chalybeate tafte. Vou. IV. u In 290 On a Submarine Foreft In order to afcertain the courfe of this fubterraneous ftra-. tum of decayed vegetables, Sir Jofeph Banks direéted a boring to be made in the fields belonging to the Royal So- ciety in the parifh of Mablethorpe. Moor of a fimilar nature to that of Searby’s well, and the iflets, was found, very nearly on the fame level, about four feet thick, and under a foft clay. The whole appearance of the rotten vegetables, we ob- ferved, perfectly refembles, according to the remark of Sir Jofeph Banks, the moor which, in Blankeney Fen and in other parts of the Eaft Fen in Lincolnfhire, is thrown up in the making of banks. barks, like thofe of the birch-tree, being there alfo abundantly found. The moor extends over all the Lincolnfhire fens, and has been traced as far as Pe- terborough, more than fixty miles to the fouth of Sutton, On the north fide, the moory iflets, according to the fifher- men, extend as far as Grimfby, fituated on the fouth fide the Humber: and it isa remarkable circumftance, that im the large traéts of low Jand which lie on the fouth banks of that river, a little above its mouth, there is a fubterraneous ftratum of decayed: trees and fhrubs exactly like thofe we obferved at Sutton; particularly at Axolme ifle, a tra&t of ten miles in length by five in breadth; and at Hatfield Chace, which comprehends one hundred and eighty thou- fand acres. Dugdale * had long ago made this obfervation. in the firft of thefe places; and De la Pryme + in the fecond.. The roots are there, likewife, ftanding in the places where they grew: the trunks hie proftrate. The woods are of the - fame fpecies as at Sutton. Roots of aquatic plants and reeds are likewife mixed with them; and they are covered by a firatum of fome- yards of foil, the thicknefs of which, though not afcertained with exaétnefs by the above-men- tioned obfervers, we may eafily conceive to correfpond with what covers the ftratum of decayed wood at Sutton, by the * Hiftory of Embanking and Draining, chap. xxvii. + Philofophical Tranfactions, vol. xxii. p. 980. : circume- on the Eaft Coaft of England. 291 circumftances of the roots being (according to Mr. Richard fon’s obfervations *) only vifible when the water is low, where a channel was cut, which has left them uncovered, . Little doubt can be entertained of the moory iflets of Sutton being a part of this extenfive and fubterraneous ftra- tum, which, by fome inroad of the fea, has there been ftripped of its covering of foil. The identity of the levels ; that of the fpecies of trees; the roots of thefe affixed, in both, to the foil where they grew ; and, above all, the flattened fhape of the trunks, branches, and roots found in the iflets (which can only be accounted for by the heavy preffure of a fuperinduced ftratum), are {ufficient reafons for this opinion. Such a wide-fpread affemblage of yegetable ruins, lying aloft in the fame level, and that level generally under the common mark of low-water, muft naturally ftrike the ob- feryer, and give birth to the following queftions : 1. What is the epoch of this deftruction? 2. By what agency was it effected ? In anfwer to thefe queftions, I will venture to fubmit the following reflections : The foffil remains of vegetables hitherto dug up in fo many parts of the globe, are, ona clofe infpeétion, found to belong to two different ftates of our planet. The parts of vegetation, and their impreffions, found in mountains of a cotaceous, fchiftous, or even fometimes of a calcareous na- ture, are chiefly of plants now exifting between the tropics, which could neither have grown in the latitudes in which they are dug up, nor have been carried and depofited there by any of the acting forces-under the prefent conftitution of nature. The formation, indeed, of the very mountains in which they are buried, and the nature and difpofition of the materials which compofe them, are fuch as we can- not account for by any actions and re-actions which in the aGtual ftate of things take place on the furface of the earth. # Philofophical Tranfactions, vol, xix. p. 28, Ua We 292 | On a Submarine Foreft We muft neceffarily recur to that period in the hiftory of our planet, when the furface of the ocean was at leaft fo much above its prefent level as to cover even the fummits of thofe fetondary mountains which contain the remains of tropical plants. The changes which thefe vegetables have fuffered in their fubftance is almoft total; they commonly retain only the external configuration of what they were. Sach is the ftate in which they are found in England by Llwyd; in France by Juffien; and in the Netherlands by Burtin; not to mention inftances in more diftant countries. Some of the imprefiions or remains of plants.found in foils of this nature, which. were, by the more ancient and énlichtened oryologifis, fuppofed to belong to plants actually growing in temperate and cold climates, feem, on - aceurate invefugation, to have been part of exotic vege- tables. In fact, whether we fuppofe them to have grown near the fpot where they are found, or to have been carried _ thither from different parts by the force of an impelling flood, if is equally difficult to conceive how organized beings, which, in order to live, require fuch a vaft differ- ence in temperature and in feafons, could live on the fame ipot, or how their remains could (from climates fo widely diftant) be brought together in the fame place by one com- mon diflocating caufe. To this ancient order of foffil vege- tables belong whatever retains a vegetable fhape, found in or near coal mines, and (to judge from the places where they have been found) the greater part of the agatized woods. But from the fpecies and prefent flate of the trees, which are the fubje& of this memoir, and from the fitua- tion and nature of the foil in which they are found, it feems very clear that they do not belong to the primeval order of vegetable ruins. The fecond order of foffil vegetables, comprehends thofe . which are found in the ftrata of clay or fand; materials which are the refult of flow depofitions of the fea and of rivers, agents ftill at work under the prefent conftitution of 9 our on the Eaft Coaft of England. 293 eur planet. Thefe vegetable remains -are found in fuch flat _ countries as may be confidered to be of a new formation. _ The vegetable organization ftill fubfifts, at leaft in part; _ and their vegetable fubftance has fuffered a change only in ~ colour; fmell, or confiftence ; alterations which are produced _ by the development of their oily and bituminous parts, or _ by their natural progrefs towards rottennefs. Such are the _ foffil vegetables found in Cornwall by Borlafe; in Effex by ~ Derham; in Yorkshire by Dela Pryme and Richardfon; and in foreign countries by other naturalifts. Thefe vegetables ‘are found at different depths, fome of them much below the prefent level of the fea, but in clayey or fandy ftrata (evi- dently belonging to modern formation) ; and have no doubt been carried from their original place, and depofited there by the force of great rivers or currents, as it has been obferved with refpeét to the Miffiffippi*. In many inftances, how- ever, thefe trees and fhrubs are found ftanding on their roots, and generally in low or marfly places iN, or very little below, the level of the fea. To this laft defcription of foffil vegetables the decayed trees here defcribed certainly belong. They have not been _tranfported by currents or rivers; but, though ftanding in _ their native foil, we cannot fuppofe the level in which they are found to be the fame as that in which they grew. It would be impoffible for any of thefe trees or fhrubs to vege- tate fo near the fea, and below the common level of its water; the waves would cover fuch tracts of land, and hinder any vegetation. We cannot conceive that the fur- face of the ocean has ever been lower than it now is; on the contrary, we are led, by numberlefs phenomena, to be- lieve that the level of the water in our globe is now below what it was in former periods: we mutt therefore conclude, that the foreft here defcribed grew in a level high enough to permit its vegetation ; and that the force (whatever it was) * Le Coudriniere fur les Depdts du geet Journal de Phyfique, Vols xxi. p. 230: U3 which id eS 6 oe ag ¥ , ) ' 294 On a Submarine Foreft which deftroyed it, lowered the level of the ground where it ftood. . There is a force of fubfidence (particularly in foft ground), which, being a natural confequence of gravity flowly though perpetually operating, has its aCtion fometimes quickened and rendered fudden by extraneous caufes, for inftance by earthquakes. The flow effects of this force of fubfidence have been accurately remarked in many places: examples alfo of its fudden action are recorded in almoft every hiftory of great earthquakes. The fhores of Alexandria, according to Dolomieu’s obfervations, are a foot lower than they were, jn the time of the Ptolemies. Donati, in his Natural Hift, tory of the Adriatic, has remarked, feemingly with great ac-. curacy, the effects of this fubfidence at Venice ; at Pola in Iftria; at Lifs, Bua, Zara, and Diclo, on the coaft of Dal- matia. In England, Borlafe has given, in the Philofophical : Tranfa&tions*, a curious obfervation of a fubfidence, of at — leaft fixteen feet, in the ground between Sampfon and Tref- | caw iflands in Scilly. The foft and low grounds between the towns of Thorne and Gowle in Yorkfhire, a {pace of ; many miles, has fo much fubfided in latter times, that fome x old men of Thorne affirmed, ‘‘ that whereas they could be- a fore fee little of the fleeples (of Gowle), they now fee the church-yard wall+.”’ The inftances of fimilar fubfidence, i which might be mentioned, are innumerable. The force of fubfidence, fuddenly ating by means of fome earthquake, feems to me the moft probable caufe to | which the ufual f{ubmarine fituation of the foreft we are {peak ing of may be afcribed. It affords a fimple, eafy explana= tion of the matter; its probability is fupported by numberlefs_ jnftances of fimilar events; and it is not liable to the ftrong objections which exift againft the hypothefis of the alternate depreffion and elevation of the level of the ocean; an opinion which, to be credible, requires the fupport of a great al ; a * oy * Vol. XLVIII. p. 62. + Gough’s Camden. on the Eaft Coaft of England. 295 Ser of proofs lefs equivocal than thofe which have hitherto been urged in its favour, even by the genius of a Lavoifier*. The ftratum of foil, fixteen feet thick, placed above the decayed trees, feems to remoye the epoch of their finking and deftruétion, far beyond the reach of any hiftorical know- ledge. In Czefar’s time, the level of the North Sea appears to have been the fame as in our days. He mentions the fe- paration of the Wahal branch of the Rhine, and its junc- tion to the Meufe; noticing the then exifting diftance from that junction to the fea, which agrees, according to D’An- ville’s inquiriest, with the aétual diftance. Some of the ‘Roman roads, conftruéted, according to the order of Au- gufius, under Agrippa’s adminiftration, leading to the ma- ritime town of Belgium, ftill exift, and reach the prefent fhoret. The defcription which Roman authors haye left us, of the coafts, ports, and mouth of rivers on both fides of the north fea, agree in general with their prefent ftate; ex- cept in the places ravaged by the imroads of this fea, more apt, from its force, to deftroy the furrounding countries than to increafe them. An exact refemblance exifts between Maritime Flanders and the oppofite coaft of England, both in point of elevation above the fea, and of the internal f{tru¢ture and arrangement of the foils. On both fides, ftrata of clay, filt, and fand, (often mixed with decayed vegetables), are found near the Gurface ; and, in both, thefe fuperior materials cover a very deep ftratum of blueifh or dark-coloured clay, unmixed with extraneous bodies. On both fides they are the lowermoft part of the foil, exifting between two ridges of high lands], on * Mem. de la |’ Acad. de Paris, 1789, p, Bias + Notices des Gaules, p. 461. + Nicholas Bergier, Hift. des Grands. Chemins des Romains, Ed, de Broxelles, vol. [J-p. 101. || Thefe ridges of high fand, both on the Britith and the Belgic fide, muft be very fimilar to each other, fince they both contain parts of tropical plants in a foffil ftatee Cocoa-nuts and fruits of the Areca are found on U4 the 296 Submarine Foreft on the Eaft Coaft of England, on their refpeCtive. fides of the fame narrow fea. Thefe twe countries are certainly coeval; and whatever proves that Maritime Flanders has been for many ages out of the fea, mutt, in my opinion, prove alfo that the foreft we are fpeak- ing of was long before that time deftroyed and buried under a ftratum of foil. Now it feems proved from hiftorical re- cords, carefully calleéted by feveral learned members of the Bruffels Academy, that no material change has happened to the lowermoft part of Maritime Flanders during the period of the laft two thoufand years *. I am therefore inclined to fuppofe the original cataftrophe which buried this foreft to be of very ancient date; but I fufpect the inroad of the fea, which uncovered the decayed trees of the iflands of Sutton, to be comparatively recent, The ftate of the leaves and of the timber, and alfo the tra- dition of the neighbouring people, concur to ftrengthen this fufpicion. Leaves, and othe delicate parts of plants, though they may be long preferved in a fubterraneous fituation, can- not remain uninjured when expofed to the action of the waves and of the air. The people of the country believe that their parifh-church once ftood on the fpot where the iflets now are, and was fubmerged by the inroads of the fea, and that at low water their anceftors could even difcover its ruins; that their prefent church was built to fupply the place of that which the waves wafhed away, and that even their prefent clock belonged to the old church. So many concomitant circumftances, though weak teftimonies, incline me to believe their report; and to fuppofe that fome of the ftormy inundations of the North Sea, which in thefe laft centuries have wafhed away fuch large tracts of land on its fhores, took away a foil refling on clay, and at laft uncovered the trees which are the fubject of this paper, the Belgic ridge, The petrified fruits of Sheppey, and other impreffions of tropical plants on this fide of the water, are well known, #* Vide feveral pspers in the Bruffels Memoirs ; 3 alfo Journ. Phyf. Vol. XXXIV. Pp. 48. h t XHI, On { 297 J XII. Ox gn Epidemical Difeafe among Cats, By J.¥. BLUMENBACH *, Tue difeafe among the cats, which prevailed lately in Denmark and various other countries of Europe, and which in Lombardy deftroyed a great many of thefe ufeful animals, induced the Council of Health at Pavia to make an inquiry into the nature of it, and to caufe the refult to be publifhed by one of their members, Profeflor Brera, in a {mall but in- terefting pamphlet under the title of Memeria full attuale Bitenia de’ Gattit. The cats attacked’ by this difeafe (Deer dejected and weak, and had an averfion to approach man; crawled about as if under great oppreffion; would neither eat nor drink 3” and could not endure any of the three plants of which they are commonly fo fond, Marum verum, Valerian, and Cat’s mint. In the courfe of the difeafe the weaknefs and dull- nefs increafed; they could fcarcely ‘f{upport themfelves on their legs; their hair ftood ereét; they let their tail hang down, and their head droop fo that their neck appeared as if prolonged; their ears were flabby and cold; the eyes feemed finaller, and the pupil contracted; the tongue was dry, and covered with yellow flime; they difcharged from the mouth a whitifh green foam, were for the moft part coftive, breathed fhort, and had a quick feverifh pulfe, ac- companied with burning heat. They at length became like mere fkeletons, were feized with violent convulfions, and generally died on the fourth or fifth day of the difeafe ; which, according to the fymptoms, was a nervous fever, ac- companied with dejection. It is, however, far from being always mortal ; and many of the animals attacked by it re- covered again gradually, without any affiftance. * From Voigt's Magazin fir der neucflen xuflande der Naturkunde, Vol. I. Part 3. t It was publifhed at Pavia laft year (1795), and confills of twenty-fix pages quarto, The 298 On an Epidemical Difeafe among Cuts. The method in which this difeafe was treated was entirely Brownonian ; that is, half an ounce of Cypras wine, with a fcruple of pulverifed valerian root, was given four times a day to the difeafed animals: aloes, and the juice of garlic, were adminiftered in fome fpintous vehicle, and alfo fumigations with vinegar. The propofal for deftroying every cat attacked by this difeafe was, with great propriety, rejected; but it was at the fame time ordered, that thofe which died of it fhould be buried at a fufficient depth in the earth; that the bodies fhould be covered with lime; and that the places where they were found dead fhould be wafhed with vinegar, ey of wood-afhes, or lime-water. It was recommended alfo to feparate, as much as poffible, found animals from thofe mfected; to give them nourifhing food; to Jay before them, in particular, their three favourite plants; and to fu- migate them often with the fteam of vinegar. That excellent phyfician and naturalift Profeffor Schacht, of Harderwyk, informed me, by a letter dated in May 1796, that the cats in his neighbourhood had for fome weeks been attacked by a difeafe which bore fome refemblance to a prurient eruption. The violent itching occafioned a de- fluxion of the eyes, which continually watered, and they at Jength became blind; their teeth at the fame time dropped out, and they died foon after with Jamentable cries. It had been obferved in the preceding months, from February to April, that their cries in the night-time, on account of theif pairing, had been extraordinarily {trong and loud. Dr. Darwin, in his Zoonomia*, mentions another epide- mia which prevails at times among the cats, and which he calls Parotidis felina. It announces itfelf by a violent fever with inflammation, and abundant fuppuration in the region of the falival glands beneath the lower jaw. We compares it to a difeafe lately known called the Mumps (Angina paro- tidea), and is inclined to believe that it was firft communi- cated to cats by infection from the human race. He men- . * Vol. IL p. 229. or | tons i ‘ On the Preparation of Crayons for Drawing, &c. 299 tions alfo a difeafe which affects the neck and head of cats, by which the greater part of thefe animals in Weftphalia died; and refers to a paffage in Sauvage’s No/ologia*, which however, in an extract of that work in three large volumes octavo t+, now before me, I have not been able to find. XIV. On the Preparation of Crayons ‘aed for Drawing, _ from the Pafte of Reddle,, By C.F. LoMEr f. Iw moft drawing-fchools, and particularly thofe at a dif- tance from the capital, many difficulties are experienced for want of good crayons. Thofe fawed from red chalk, which are in common ufe, are almoft always hard, gritty, and often of an unequal confiftency ; fo that the touches in the drawings for which they are ufed can never have the firength or correctnefs neceffary to produce the defired effe&t. The only good crayons ufed in France are manufaétured exclu- fively at Paris, where they are fold very dear: the bef fort have been long known by the name of the pafte- crayons of Defmarets, who apparently was the inventor. As no author who has written on the compofition of thefe crayons has pomted out the proportions of the ingredients neceflary to be ufed, I made many trials with every combination of the fubftances that appeared to me proper for making them. I rejected thofe produéts which did not anfwer the objects of my refearch; and I here fubjoin thofe mixtures that gave me fatisfactory refults. Thefe pencils are compofed of the fofter kind of reddle, which is an oxyde of iron mixed with earth of an argilla- ceous nature, and called hematites, or bog-ore. It muft be incorporated with fome agglutinating fubftance, fuch as gum, fize, or refin; to which fometimes foap is added, ta * Nofol. cl, X. art. 30. 8. + Amft. 1763. } From the Aunales de Chimie, No. 90. an. 7 foften 400 On the Preparation of Crayons for Drawing, foften the compofition. Inftead of reddle the other red ox- ydes of iron may be ufed, fuch as coleothar of vitriol, &e. 5 and in that cafe they fhould be chofen foft to the touch, and of a lively colour; for thofe ufed in commerce are often mixed with too much clay, which gives them a dull yellowith eaft that ought to be avoided. I attempted to incorporate thefe fubftances with the whites of eggs and the albumen of blood; but crayons compofed in this manner were not good. The beft reddle,:in lamps, fhould be fele&ted and ground with pure water on a marble flab, as is done in the prepa- ration of colours for painting; taking care to moiften it as much as is neceffary to make the grinding ftone glide, and to. employ as little water as poffible. When itis intended to prepare a large quantity of this fubftance, this operation be- comes very difficult and expenfive: in that cafe a different method mult be ufed. The reddle muft be pounded and fifted through a fine fieve, then diluted with a large quantity of water in a trough; where, after it has been. well ftirred round, it fhould be left a few minutes to fettle, in order that, the grofler particles may precipitate themfelves to the bot- tom. The water, which is ftrongly impregnated with the finer particles, is then poured off, and fuffered to fettle for twenty- four hours. The clear water on the top is then poured off again, and avery fine fediment will thus be obtained, which muf{t be pounded and wafhed once more. The fediment of the firft wafhing mut be treated in the like manner, andthe procefs is. repeated until the whole be reduced to the utmoft finenefs. leftined to give the crayon the The gum, fize, or foap, < neceflary degree of fchidity, muft be diffolved feparately. Thefe folutions muft be carefully mixed with the pounded reddJe, and the watery particles muft be evaporated by being expofed to. the fun or to the heat of a gentle fire, taking care to turn the pafte often till it has acquired a confiftence fome- what harder than butter: the crayons are then to be formed tn the moulds The - fromthe Pafle of Reddle. got -. The moulding may be performed two ways: the firft is, to fpread out the pafte on a board, in which are cut grooves rather broader at the top and round at bottom; and of 2 any length, fize, and depth, proportioned to the intended fize of the crayons. The fecond, which is the better me- thod, is to force the pafte through a pipe or funnel of an ori- fice equal to the fize of the crayon. The pafte thus formed may be left to dry flowly in a cool place under the fhade, in order to prevent cracks, which too hafty deficcation might produce. When ihe rods are dry, they are to be cut inte pieces of the defired lencth: the edges muft then be taken off; after which they muft receive the firft cutting, to give them a blunt pomt. The laft operation is to ferape them, in order to take off the hard outward coat formed on the fur- face while they are drying, and which would prevent them from making any marks. It may be neceflary to rub a {mali portion. of oi] into the grooves of the wood, that the pafte may not adhere too clofely to the moulds. v Gum arabic and ifinglafs are the two fubftances to be preferred for mixing with the powder. It will be fufficient to diflolve the gum.and foap in cold water; but the ifinglafs muft firft be cut into {mall pieces, then put into hot water, and diflolved in balneo marie. Thefe folutions fhould be well diluted with water, that they may be made to pafs ’ through a hair fieve in order to remove any foreign particles. - As it is difficult to incorporate the pafte with the ifinglafs, they muft both be heated and mixed over a fire with a heat equal to that of boiling water. The pafte muft be well mixed before it is moulded, in order that it may be uniformly in- | corporated with the folution, and that there may not remain . any hard lumps. The beft way would be to beat it with z pefile or mallet, and to pound it again for fome time before it is put into the moulds. No ow be employed but for thofe crayons in which gum is ufed. In all the trials I have made with ifinglafs and foap, . 302 On the Preparation of Crayons for Drawing, foap, not one of them fucceeded: and it muft neceffarily be fo; for, the excefs of alkali in the foap, operating on the gelatinous matter, deftroys its agelutinating quality. As the crayons for which foap has been ufed are of a browner caft, it would appear that this combination abftracts the oxygen from a part of the red oxyde of iron, and gives it a brown tint by making it approach the ftate of martial zthiops. I have remarked, that all the paftes prepared with oxyde of iron, even when pure water alone is ufed, grow brown on the exterior furface as they dry: this takes place in a more fenfible manner when thcy are expofed to the aétion of the fun ; which feems to arife from the light ab- ftracting a portion of oxygen from the oxyde of iron. At fome future period I fhall enter into a farther inquiry refpect- ing the chemical properties of thefe preparations; but at pre- fent I {hall content myfelf with pointing out the proceffes which have conftantly fucceeded with me, and infucha | way that they may be put in practice any where with fuc- cefs. The crayons compofed in this manner have every good property that can be defired; they do not coft one quarter the common price: but it muft be obferved, that their com- pofition requires great nicety in regard to the quantity of the materials, becaufe the leaft variation occafions confiderable difference in the quality of the pafte. Particular care mutt alfo be taken to guard againit the errors that may arife from the wafte, which is unavoidable during the courfe of the ope- ration. The beft means to prevent it will be, to fix by ex- é periments the quantity of water and of ingredients which ~ the pounded reddle and the folutions form before the mix- — tures are made. By means of the following tables, which exhibit the quantity of ingredients to be ufed for the different © kinds of crayons, it will be eafy to know what PFoportion of y gum, ifinglafs, or foap, muft be employed for a determined i quantity of reddle, or red oxyde of iron. 1 Indication ; from the Pafte of Reddle. 303 Aaaeater of the Subfiances to my ufed, their Quantities, and what they will produce. L. Dry reddle, or red oxyde of iron, 1 ounce; gum arabic, dry, 18 grains.—Thefe crayons are very tender, but they may be employed for large defigns. As they are the kind in which the leaft gum is ufed, they have not fufficient con- _ fiftence for any other purpofe. II. Reddle, &c. 1 ounce; gum 21 grains.—Strong crayons, alittle tender, but excellent for large drawings. Ili. Reddle 1 ounce, gum 24 grains, or rather 25} grains. —Soft and folid crayons: they are the beft that can be em- j ployed for common ufe. IV. Reddle 1 ounce, gum 27 grains.—Crayons rather firm, but not hard; ufeful for drawings that require delicacy. V. Reddle 1 ounce, gum 30 grains.—Very firm crayons, proper for drawings in which every ftroke is intended i be given. VI. Reddle 1 ounce, gum 33 grains.—Very hard crayons, which cannot be ufed without fome force. The largeft quan- ‘tity of gum that can be employed is ufed in their compofi- tion: with more they would be ufelefs. VII. Reddle 1 ounce, gum 22 grains, white hard foap 30 grains.—Thefe crayons have a little browner caft than the former ; they are of a very good confiftence, and can be eafily eut. All crayons, however, in the compofition of which foap is employed, are attended with this fault, that the ftrokes they make have a fhining appearance if the touches are repeated alittle too ftrongly. No other experiment with foap fuc- ceeded. Thefe crayons have a perfeét refemblance to thofe ‘made by Defmarets. VIII. Reddle 1 ounce, ifinglafs 36 grains _—Crayons of a brilliant colour, and excellent for ufe. If lefs ifinglafs is employed they become brittle; and if more, they are too hard. XV. Defcrip- { 364: } XV. Defcription of HumBout’s New Portable Barometer™s "To have a barometer compofed of feveral parts which — could be eafily put together, and which fhould correét itfelf at each obfervation like an aftronomical inftrument, were the reafons which induced M. Humbolt to devife the pre- fent conftruétion. Tralles, the learned aftronomer of Berne, | has judicioufly obferved, that all barometers are liable to be broken when the tube is fixed to the feale which belongs to © it. In Humbolt’s barometer the tube is diftin@ from the fcale; and when the tube breaks, its place can be fupplied by another even on the top of a mountain. The tube, the 7 lower part of which is reprefented by aéc (fig. 1. pl. VII.) is cemented into an iron one dc, two inches long, terminating © in a nut c, which receives a ferew to the depth of 2% lines: © the end of the {crew is fquare. When the tube is filled with © mercifry, and {crewed clofe, it is put into a tube of copper | lined with flannel, and covered on the outfide with leather. This cafe may be carried as a cane; the head d of the ferew © being kept, as far as poffible, in a vertical pefition. If the ; entrance of air be apprehended, it will lodge itfelf under @.— In that cafe turn the {crew and pour’a drop of mercury upon | it before it is fhut. The whole tube may be examined to | fee that the mercury is not feparated by air bubbles; an ad= yantage wanting in the Englifh barometers, in which the tubes are half concealed. The mahogany pillar eg f (fig. 2.) contains the mercury, to be poured into it after it has been ' fcrewed into its ftand gh (fig. 3.), fupported by three feet that fold over each other. The interior part of the column ¥ * From the Yournal de Phyfique, an. 7. Defeription of Humbolt’s Barometer. 405 As the fquare cd cannot then turn, being held faft in the pillar, the {crew is loofened, ed finks down floating on the mer- eury, and the atmofpheric air has free communication with the mercury in the tube. The Torricellian vacuum is formed under £, and the mafs of mercury in the column is increafed. The feale mo (fig. 4.) is attached to a wooden rod nop, formed of two pieces of timber of a different kind, and ferewed at p arid g to the mahogany pillar. Turn the three {crews rrr until the vertical pofition of the inftrument is announced by the plummet s._ If you fix the feale to the tube £a, by ferewing clofe the fcrews 7 and m, there will be too much mercury in the pillar. The point o of the baro- miéter is placed in the aperture of the cock s, and you will have a conflant level by opening that cock and fuffering the mercury, which you muft colleé& in a {mall vafe, to flow down. In order that the ivory cock s may not open of itfelf, there is, at ¢, 4 fork which by a fcrew can be fixed im each pofition to prevent it. When the obfervation is made, you place in ge afmall cufhion, or covering, held by two fcrews vv, which prevent the efcape of the mercury while you are walking; or you difmount the inftrument by again pufhing the tube £/m (unfcrewed at m and /) to the bottom of the pillar f, where you turn the {quare cd. The Torricellian vacuuna is by thefe means filled, and you turn the tube to the left, holding it with your hand between Zand m until you ob- ferve that cd has caught, and that the aperture of the tube is clofed. You then draw out the tube with cd well fhut in order to inclofe it in its cafe. There is a lofs of a few drops of mercury which adhere to the iron. One of thefe inftruments, conftruéted two years ago, has remained un- hurt during a great many journies over the moft rugged roads and the fteepeft mountains. More time is required to make an obfervation with it than with a common barome- ter; but it is the only one perhaps which could with cer- tainty be ufed, were it to become deranged even in the deferts of Thibet. Vou, IV. x Thefe 306° - \Pofifeript to Valta’s Letters Thefe inftruments are now made at Berlin, Weimar, Drefden, Vienna, and Paris. On coming from a cold to a very warm temperature the fcrew cd mutt be loofed before you approach the fire. This inftrument has an advantage by which it is diftinguifhed from. all others: it is the only one in which the fize of the Torricellian vacuum depends on the obferver: the height of the mercury remains the fame to whatever depth it be plunged in the mercury, provided you take care each time to adjuft the level by the cock. Mufcati has proved, that the barometric height is affected by the fize of the vacuum on account of the attraction of the glafs in 4, and becaufe the minimum of air which the va- cuum. contains. is. more or lefs dilated. In Humbolt’s ba- rometer, the fame Torricellian vacuum exifts on the tops of the mountains as, in. the valleys. The different pieces. of which this inftrument confifts are contained. in one cylinder, which may be carried on the thoulder like a,fuzee. Several tubes may be contained alfo in a walking-ftick. Having for two years meafured the height of different mountains with Humbolt’s barometer, and others. conftruéted on the old. principles, no. fenfible differences were obferved, though this operation, for various reafons explained by Tremblay, is ftill very far froma perfec- tion. XVI, Pofi/cript to Volta’s Letters on Animal Eleétricity*. Some new facts, lately difeovered, feem to fhew that the immediate caufe which excites the electric fluid, and puts it in motion, whether it be an attractive or a repulfive power, is to be aferibed much rather to the mutual contact of two dif- ferent metals, than to their contact with moifl conductors. But, though it cannot be denied that in the latter cafe there, exifts.an action, it is proved that it exerts itfelf in a far more * Sce page 59 and 163. . confider~: en Animal Eleétricity.: 409 éénfiderable degree when the two metals mutually touch each _ other. There arifes by the mutual contaét, for example, of i -filver and tin, an action or power by which the former com- _ imunicates the electric fluid, and the Jatter receives it ; or the _ filver fuffers it to efcape, and the tin attra@ts it. This pro- _ duces, when the circle is rendered complete by moift conductors, a ftream, or continual circulation of the fluid. When the circle is complete, there is an accumulation in the tin at the expence of the filver; which indeed is very fmall, and far under the point neceffary to enable it to announce itfelf by the moft delicate electrometer. I have however been able, by the affiftance of my condenfer, conftru€ted on _ anew plan, and ftill better by Nicholfon’s Doubler, to render it very perceptible: I thall here communicate the refult ob- tained by my experiments, which I made fome time ago with - great fatisfaction. Exper. I. The three plates of the doubler are of brafs, T took two ftrong wires, one of filver and the other of tin, and brought the former into contaét with the moveable plate, and the other with one of the fixed plates; while they both refted on the table, or, what is better, on moift pafie- board, or any other moift conductor, fo as to be in commu- hication by the intervention of one or more conduétors of _ the fecond clafs. I fuffered the apparatus to remain -fome hours in this ftate, then removed the two wires, and put the -machine in motion. After 20, 30, or 40 revolutions, (or more when the atmofphere was not dry, or the infulation Amperfeét,) I brought one of my ftraw eleGtrometers into eontact with the moveable plate, and obferved indications of Pofitive electricity (+E) which arofe to 4, 6f 10 degrees, and more. If I fuffered it to touch the fixed plates, I had the torrefponding indications of the oppofite kind of electricity (—F). The filver, therefore, poured the elaftic fluid into the brafs plate when it had been fome time. in contaét with it; and the tin attracted it from the other plate, which was alfo of ¢ X32 brafs, | 308 Poftferept to Polta’s Letters brafs, while in contact with it. This was confirmed by the following experiment, which is a real experimentum crucis. II. I reverfed the experiment, fo that the filver was im . ~ contaét with one of the fixed plates, and the tin with the moveable one, The electricity which I obtained from the 7 latter, after the apparatus had remained a fufficient time in that pofition, was negative (—E); while that of the fixed plate was pofitive (+E). III. L applied only the tin wire to the moveable plate, and infulated the two fixed ones, or brought them into eom- munication with the table er any other moift conductors with which the tin wire was in contact. This fimple contaét of the tin with the brafs, of which the moveable plate con- filts, is fufficient to excite in it a yery fmall-degree of nega- tive electricity ; only a longer time is required. Thofe acquainted with the action of electric atmofpheres, and the conftruction of the doubler, will need no farther explanation to enable them to comprehend the mode of ac- tion of this very ingenious inftrument; how the electricity, once obtained from the moveable plate, muft occafion am oppofite kind in the fixed plates, and wice verfa; how the oppofite kinds of ele¢ctricity are increafed by each revolution of the machine, &c. In the prefent experiment, therefore, when the moveable plate is ~ FE, the fixed plate muft be +E. — TII. This is the reverfe of the former. The piece of tin © was applied to one of the fixed plates, and the moveable one ~ was infulated from all metallic contact. The refult was now ~ -reverfed; that is, the fixed plates were electrified negatively, and the pareatle one had pofitive eleétricity. ( All thefe experiments fucceed: much better,.and in a fhorter ; time, if, during the mutual contac of the different metals, — the moveable plate be oppofite to either of the other two that are fixed; but ftill better when a piece of thick paper, fuch as a card, not moift, and of a thicknefs equal to the inter-_ mediate fpace, is placed between the two plates that ftandi @ppofite te each other, It is of advantage to leave the card” fom on Animal Eleéricity. 309 fome time in its place, and not to remove it till the moment when the metals in contaét are removed and the machine put in motion. , To render the infulation complete, and make the conta& of the metals immediate, without the leaft moifture, which would be highly prejudicial, it will be pro- per to place the apparatus inthe fun. Half an hour, and often lefs, will then be fufficient to obtain the required electricity, &c.; whereas, in other cafes, feveral hours are neceffary before the defired refult can be obtained. A re- prefentation of this experiment is exhibited by fig. 21, 22, 23 and 24, (Plate I.) LLL (fig. 21 and 22) are the three brafs plates of the doubler; A the piece of filver which is in conta& with one of thefe plates; E the piece of tin applied to the other plate, which is oppofite to the former; aa the moift conductor, or chain of moift conductors which form a communication with the pieces of metal. When the filver, as in fig. 21, is in contaé& with the ante- rior moveable plate, it gives up to it a little of the electric fluid, and the latter accumulates as much of it as poffible ; confequently the electricity of the plate becomes pofitive, as the fign + of the plate fhews: whereas the tin attracts the eleétric fluid from the correfponding fixed plate, which by thefe means has negative electricity, as the fign (— ) of the plate indicates ; and it even communicates this electricity to the other fixed plate, which therefore has the fign ( —) alfo, ~ In fig. 22, every thing is reverfed : the moveable plate is negatively electrified (— E), while the two fixed plates be- come pofitive (+ E). Laftly, in the 23d and 24th figure, it is feen, that the tin abftracts the eleétric fluid from the brafs plate with which itis in contact. This plate is therefore negatively clectri- fied, or has — E; and by the action of its atmofphere occa- fions pofitive electricity (+ E) in the other plate ftanding oppofite, which is in communication, either with the third plate, as fig. 23, or, what is ftill better, with other con- ductors, as fig. 24. Thefe oppofite eleéricitics increafe af- ’ X3 terwards + » \ 310 Pofifcript to Volta’s Letters ‘ terwards with each revolution of the machine ;. the aétion of — which, according to the theory of electric atmofpheres, pro- duces this effect to the degree mentioned, and juftifies the appellation of doubler of electricity, which has been given to this inftrument, T now come to the experiments, which fhow that we are to feek for the caufe which calls forth the ation of the eleétric fluid; which exeites it, of whatever kind it be; determines its tranfition, &e. much rather in the mutual contaét of the metals, than in the contaét of the moift conductors with, thefe metals. Though, according to eyery circumftance, we muft admit fome action of this kind in the latter conta&, it cannot be denied that the former is certainly the moft ef- fe&tual. At prefent I fhall only mention the two following experiments, which I contrived in fuch a manner that they may ferve to explain a queftion of this kind. V. T left the two fixed plates of brafs without making any alteration ; took off the third moveable plate, and fupplied its place by one of tin; and arranged the machine in fuch a manner that the latter ftood oppafite to one of the other two plates. I then applied to this tin plate a bit of brafs, and to the oppofite fixed plate of brafs a piece af tin, Af- ter a convenient time, (for example an hour, when the wea- ther was perfectly dry,) I took away the two pieces of me- tal, or only that of brafs, and made the moveable-plate of tin, which was in contaét with the piece of brafs, to revolve about thirty times. It then gave me very perceptible marks. ~ of pofitive electricity. VI. [ reverfed the former experiment, and made the piece of brafs touch the brafs plate, and the piece of tin the plate of the fame metal. I, however, obtained nothing, or almoft no- thing; even when the apparatus was left a much longer time in that fituation, and when the machine had made twice or three times as many revolutions. Thefe two experiments are reprefented by fig. 25 and a where L is the piece of brafs; E that of tin; and ga the moift | on Animal EleGricity. git moift condugtors which conneé the two different pieces of metal. In the arrangement of fig. 26, the fame contaét of se ent metals, viz. brafs on the one fide, and tin on the other, with the fame kind of moift conductor, takes place, as well as in the preceding experiment of fig. 25. . The addition of the eletric fluid in the one, and the abitraétion of it in the other, ought therefore equally to take place, though in an in+ _ verted order, when the action on the fluid calls forth the moving power, by this contaSt of the two metals L, E, with the moift conductor between them; and yet this is not the cafe, as no figns of eledlricity are obtained even after a ‘long time, and when the machine has been caufed to make twice or three times as many revolutions. The condition effen- tially neceffary to obtain electricity is, that the different me- tals muft be in contact with each other, which is the cafe in fig. 25, but not in fig. 26. When the machine has been repeatedly turned, fome- thing may be obtained, This arifes either from fome fmall remains of old electricity, which could not be deftroyed or diffipated in the time duringw hich the arrangement of fig. 26 was continued; or even from frefh electricity, which the moveable plate may have obtained from the atmofphere or vapours during the pretty confiderable time of the machine being in a ftate of revolution; or fome accidental difference, either between the two tin or the two brafs pieces, may be the caufe of fome action on the electric fluid, or of fome de- rangement in regard to the equilibrium, In the laft place, the contaét of the moift conductor with the tin on the one fide, or with the brafs on the other, may have a different aftion, which, in my opinion, mutt be very {mall, but yet is not entirely without effect. _As it is now proyed that, according to the arrangement of the fixth experiment, nothing, or almoft nothing, is ob- ‘tained by 40, 60, and even 80 reyolutions of the doubler, while a great deal is obtained by that of the fifth with 20 X 4 or 312 Progre/s of the Vaccine Inoculation, and or 30, we muft therefore conclude that the contac of two metals of a different kind with moift conduétors, without the mutual contact of thefe metals themfelves, (which is wanting in the fixth experiment, where brafs is in contaét with brafs, and tin with tin,) produces nothing or almoft nothing; and that, on the contrary, the mutual contact of the two metals of a different kind, which ta‘es place in the fifth experiment, produces the whole, or almoft the whole, effect. | XVII. A Statement of the Progre/s in the Vaccine Inocula- tion ; and Experiments to determine fome important Faéts belonging to the Vaccine Difeafe. By GrorGE PEAR- son, M.D.F.R.S. Phy/ician to St, George’s Hofpital, &e. Tue collection of teftimonies which I publifhed, in No- vember laft, in my Inquiry concerning the Hijiory of the Cow- pox ; and the Circular Letter, which I iffued in March, ftating the progrefs of the Vaccine Inoculation, and contain- ing thread impregnated with matter, have procured me much information. In particular, through the recommendation of the Surgeon-general, Thomas Keate, E/q. the new practice has been introduced into the army; of which a valuable re- port has been already communicated, I have heen alfo fo fortunate as to obtain permiffion to practife the mew inocula- tion in certain fituations where great numbers would have been inoculated for the fmall-pox. The cafes from thefe fources, and a pretty large ftock from private practice, form 2 valuable body of evidence, by means of which the profef- fional public will be enabled to eftimate (I do not fay pre- cifely) the value of the new praétice ; and alfo anfwer many of the queries, and fupply fome of the deficient parts of the hiftory of the vaccine difeafe, which were ftated in the In- quiry above mentioned. But fuch are my occupations at prefent, and in all likelihood fuch they will be for a, confi- derable time, that I cannot at this time arrange, for the ufe of the ) Extcriments refpefting the Vaccine Difeafe. 333 the public, the valuable materials tranfmitted to me. ft will, however, perhaps be not without utility at this time firft to ftate a few general refults from the vaccine inocula~- tion ; and fecondly, to relate fome ¢tria/s, from which I ap- prehend conclufions can warrantably be drawn to promote the inveftigation now going forward. Not much more than fix months have elapfed fince the opportunity was afforded, by the breaking out of the vaccane difeafe in two principal milch farms near London, of obtain- ing matter for propagating the fame difeafe among human creatures. The mew inoculation was immediately introduced in London, and foon afterwards in the neighbourhood, as well as in many provincial fituations. It is with fincere fatisfaCtion that we can now reckon, at the feweft, 2000 per- fons who have paffed through the cow-pox by inoculation, But in this number I include the very large proportion far- nifhed by him who, fo beneficially to the public, and ho- nourably to himfelf, poifeffes the office of phyfician to the Small-pox Hofpital. From the above experience we receive, as I expected, important information. 1. Of the above number it appears that ove patient died ; (Woodville’s Reports, p. 151.) and to avoid controverfy, fet us allow that the death was occafioned folely by the ino- culation. Now, according to the jufteft calculation I have been able to make, as in the inoculated fmall-pox one in #00 * dies from the difeafe, it is evident, in the prefent ftate of * Tam fully aware that fo great a proportion as one in 200 will not be allowed by many praétitioners. And to perfons who have been told, and believe, that inoculation for the fmall-pox ‘ fcarcely ever does any harm” —that certain praétitioners have inoculated many thoufands without lofing @ patient—that others have told their friends “ they never had a fatal ino- culated cafe in their whole lives’’—l1 fay to {uch pertons, no advantage, om the feore of faving life, will be allowed from the cow-pox. But 1 have converfed with many candid and experienced practitioners, and they are well fatisfied that I am warranted in the above ftatement of deaths in the jucculated yariola, I beg Rave to fay farther, that [ believe aiore per~ . ; fons 314 Progrefs of the Vaccine Inoculation, and of the practice, that the proportion of fatal cafes in the ino~ culated fmall-pox, to the inoculated cow-pox, is as Io to I. g. The conftitutional affection, or fever, which occurs in the cow-pox about the gth day after imoculation,. is much more confiderable in many cafes than was apprehended from the firft account by Dr. Jenner, although ina great propor- tion of cafes it is extremely flight, and in many cannot be obferved at all. But I mutt correct my ftatement in March Jaft, in which I faid, “ Although the extreme cafes of the fevere kind, which ordinarily occur in the fame number of ‘cafes in the inoculated fmall-pox, did not occur in the new practice, and although many of the patients were even more flightly difordered conflitutionally, yet the whole amount of the conftitutional illnefs feemed to be as great as in the fame number of patients in the inoculated fmall-pox.”” Since that report, or at leaft for the la(t four months, as far as I have ob- ferved and been able to learn from others, the whole amount of the conftitutional illnefs was not one half of the whole amount in an equal number of patients inoculated for the fmall-pox. Now, whether the greater mildnefs of the difeafe depended on the different flate of the human conftitution in the fummer from that of winter, as feems to me moft pro-’ bable ; or that it depended on the difference in the flate of the vaccine matter, muft be determined by future experience m the fame feafons. 3. The moft remarkable difference in the practice of the faft winter, and prefent fummer, has been with regard to the eruptions which fo often occurred, efpecially in the Small- pox Hofpital; which eruptions, in many inftances, could not, fons in proportion have died of the inoculated fmall-pox within a few years, than died in the fame time 20 years ago. And this may be account- ed for from the unwarrantable affertions of many inoculators, from whom a great part of the public have imbibed the opinion, that the inoculated finll- -pox wasznot attended with any danger; hence the praétice is often wufted in the hands of perfons not fufficiently acquainted with the treat- ment fit for diferent (tates of the human conflitution, be a, Experiments refpeding the Vacoine Difeafe. 315 be diftinguithed from thofe of the fmall-pox, and which were wholly unexpected from the original defeription by Dr. Jen- ner. No explanation hitherto given confifts with the ob- fervations relative to thefe eruptive cafes: but the facts are as Dr. Woodville ftates (Med, Mag.), that they have oc- curred much lefs frequently this fummer than in the {pring ’ and winter preceding. In my private practice, not a fingle cafe with eruptions refembling the f{mall-pox has occurred thefe laft four months, and but a fmall proportion with any eruptions of other kinds. From my correfpondents I have not had a fingle cafe of eruptions like the variolous fince that of Dr. Redfearne’s of Lynn ; not one of this forfin Mr. Kel- fon’s, of Seven Oaks, report of about 190 patients ; not one in Dr. Mitchell’s, of Chatham, of about 50 patients; not one in the report of near 100 patients from Dr. Harrifon of Horncaftle, communicated to the Rt. Hon. Sir Jofeph Banks ; and, in fhort, not one cafe with thefe eruptions ap- pears in the accounts from my other corre{pondents.. 4. The arms have manifefted, in many inflances, a much more extenfively {preading red areola around the inoculated part than is ufual in the {mall-pox ; which rednefs fome- times extended over the greater part of the whole arm. : This appearance is very alarming to both the patient and the in experienced practitioner ; but no danger {eems to be attend- ant on fuch a ftate of the parts, for it dufappears in at mofé two or three days, by no means gives pain in proportion to its appearance, and, in the cafes I have feen, affects the conttitution very little. I would rather call this fpreading rednefs of the fkin erythema than eryfipelas. As to phage- denic ulcers, as they have been called, enfuing from the inoculated part, many fore arms have been produced; but niné out of ten were occafioned, or at leaft much aggravated, by the tightnefs of the clothes; by allowing the linen to ftick to the fore; by {cratching the puftule; and fometimes by emol- lient poultices.. The experience we have had, then, fince Ja~ nuary Jaft, i London and in the country, does not agree ex- actly. 316 Progrefs of the Vaccine Inoculation, and adily with Dr. Jenner’s account concerning the ftate of the arms; he thinks fome new applications of a cauftic nature neceffary, in many cafes, to prevent fecondary fymptoms from the fores; but in Dr. Woodville’s Report, p. 155, my cor- refpondents, and my own pra“tice, there has not been found any want of applications for fuch a purpofe. Lf Concerning the important point of the certainty of the action of the cow-pox on the human conftitution in producing unfufceptibility of taking fubfequently the fmall- pox; I can only at prefent fay, that I have moculated many {cores with fmall-pox matter after the vaccine difeafe, and never with the effeét of exciting the fmall-pox. But I have had accounts fent to me, not of people taking the fmall-pox after the inoculated cow-pox, but of thefe taking the fmall- pox after the cow-pox in the cafual way. I have, indeed, been defired to fee even fome of my own patients who, I was acquainted, had taken the fmall-pox after the cow-pox ; but thefe cafes turned out to be either thofe in which the cow-pox had pot in reality preceded, or they were cafes of merely local affection from the inoculated fmall-pox. With refpe&t to the facts of other practitioners, I fhall at a future time make fome remarks on them, to render their accounts content with thofe of Dr. Jenner, Dr. Woodville, and mine. In the mean time | will not allow that any per- fon’s evidence is on this pot much to be depended upon, anlefs he really know what are characters of the cow-pox pufiule, and what are thofe of the variolous and fome other eommion eruptions. From the preceding general refults, without entering into a more particular account, I think we may fafely conclude, that the cow-pox inoculation is attended with advantages fuf- ficient to force its way {peedily into general practice, and that of courfe it will fuperfede and ultimately extinguith the fmall~ pox: but this conclufion is only drawn provifionally, vz. that no new facts fhall arife adverfe to the experience now poffeffed. With regard to the fecond objeét of this paper, Dr. Jen- L Net, Experiments refpetting the Vactine Difeafe. Qty ner, very ufefully to human fociety, and very honourably to himfelf, firft publifhed fome Facts, which I thought it my duty, in common with other members of the profeflion, to inyeftigate, and have laid before the public. Among thefe fads the 4th and 5th were afferted by me in thefe terms: IV. A perfon having been affected with the fpecific fever and local difeafe produced by the cow-=pox potfon, is liable ta be again affeéted, as before, by the fame poifon; and yet Such perfon is not Sfufceptible of the Jmall-pox. yo perfon is fufceptible of the cow-pow who has antece- dently been affected with the [mall-pox. Neither of thefe facts being fupported by any analogy, 2 great part of the public feemed inclined to difbelieve them ; and not only inclined to difbelieve thefe facts, but the credit of the others was for obyious reafons thereby weakened. It may be feen in my Inquiry, that I thought the affertions ftood in need of confirmation, which I was not only unable to procure, but contravening eviderice was obtained. Some of my correfpondents not only afferted that men were not affected more than once, but that the fame cows had not been known to be affeéted more than once. It was alfo pofitively afferted by fome, that “a perfon is not liable to the infe@ion of the cow-pox after going through the fmali- pox, (p. 49, Inquiry :) and I faw perfons pitted with the fmall-pox who had been much expofed to the cow-pox without taking it, (Ibid. p. 50.) Notwithftandiag my con- fidence in Dr. Jenner’s evidence, I could not help pointing out, in the following words, what I apprehended was a fource of error in both cafes: —“ The evidence for this fact (viz. ‘IV.), to my apprehenfion, only proves fatisfaGtcrily that the local affeétion of the cow-pox may occur in the fame perfor more than once; but whether the peculiar fever alfo occurs more than once in the fame perfon from the cow-pox poifon: does not appear certain, and mutt be determined by future obfervations made with a particular view to this point.” Farther: Iwas fo diffatisfied that I wrote to Dr. Jenner to anlwer 318 Progrefs of the Vaccine Inoculatian, and” anfiver my query, Whether, in the inftances of the cow-pot occurring more than once in the fame perfon, it was certain that the fpecific fever was prefent more than once? The Doétor very obligingly anfwered my letter, and fays, (fee Dr. Jenner’s Letter, p. 99. of my Inguiry,) “ You may be affured that a perfon may be repeatedly affected both locally and generally by the cow-pox 3; two inftances’ of which I have adduced, and have many more in my recolleétion.’”” But he very candidly adds: “ Neverthelefs, on this import+ ant point I have fome reafon to fufpect, that my difcrimina- tions have not been, till lately, fufficiently nice.’’ With refpe&t to Faé&t V. I faid in my Inguiry, p. 4g: “It feems fufficiently authenticated that people may have the cow-pox after they have had the fmall-pox ; but it will re- quire more nice attention to fatisfy the query, Whether, in fuch cafes, the cow-pox affeéts the whole conftitution, or is > only a local affection?’’ Subfequently to this obfervation I find Dr. Jenner himfelf, from a theoretical confideration, offers as a * conjecture what experiment mutft finally deter- mine that they who have had the fmall-pox are not after- wards fufceptible of the primary action of the cow-pox virus.” (Farther Obfervations, &c. by E. Jenner, M.D. &c. p. 32.) I fhall now relate the tria/s I have inftituted, and the ob-+ fervations 1 have made, to obtain determinations with refpe@ to thefe important queftions of facts. Trials to determine whether or not Perfons are Sufceptible of having the Cow-pox PustuLeE and FEVER, who have undergone the Small-pox. The four firft-named gentlemen being engaged with me in, profecuting phyfical inquiries, were defirous to experience, in their own perfons, the effects of the vaccine poi/on. -1. Mr. Dangerfield was inoculated in one arm by means of a puncture with a lancet ftained with frefh but dried mat- ter, rendered fluid by fteam juft before it was inferted. The other arm was inocuiated with thread impregnated with vae- cine peta Tite cee Niet imate at ao" Experiments refpecting the Vactine Difeafe. 3t9 tine matier by pafiing it through the fkin. On viewing the } a arms in three days time, that with the thread appeared in- _ flamed, fhowing a red cleyated {mall fpot; the other arm, which had been punétured, barely thewed ared mark. The punctures had fmarted for about twenty-four hours, but no other effects ” were produced. Thefe red fpots difapyeared.in afew days. In three weeks. further the inoculation’ was again infti- _ tuted, but with fluid lymph applied, immediately from the puftule of a patient prefent, to punGiures in each arm. More fmarting and more inflammation were produced by this in- oculation than by the former. A {mall quantity of pus was ' produced in the little red {pots from the punctures in about fix orfeven days, but no diforder arofe in the whole conttitution. Mr. Dangerfield was next inoculated in one arm with variolous matter. In the evening of the day of inoculation inflammation appeared, which increafed to a greater degree and extent than from the vaccine inoculations. A fmall _ phlegmonic tumor in the part inoculated with variolous matter continued for a fortnight, during which time it fuppurated, and the pus from it did not heal in lefs than _ three wecks further. There was no conftitutional affection ; but there was pain in the arm-pit in about five days from . the inoculation. 2. Mr, Pollock was inoculated in each arm with a lancet armed with fluid matter immediately on taking it from a patient. . A little fmarting was felt for a day or two, and the parts inoculated were red for feveral days; but no puftules arofe, nor conftitutional affection. 3- Mr. Perkins was. inoculated by puncturing ome arm with a lancet ftained with recent vaccine matter, and, the other was inoculated with variolous matter. ...A, red fpot was feen on each of the parts inoculated the day following; and an itching fenfation, efpecially from the vacc?ne matter, was experienced for a dayor two. The parts remained clevated and inflamed a little for. a few days further, and then got 9 well 320 Progefs of the Vaccine Inoculation, and well without fuppurating, or being re by any general diforder. 4. Mr. Armitage, whofe conftitution was fat and muf- eular, was inoculated m each arm, with a lancet ftained with’ _Hmpid vaccine matter, immediately on taking it from a pa- tient prefent. A fmall red {pot was obferved the day follow- ing, and a little burning fenfation was complained of; the red {pots grew larger and larger for four or five days, and at Fength produced a fmall unequal hard tumor, in which a2 — little pus was generated ; but the parts foon got well with- — out any attending diforder of the whole conflitution. In a fortnight after this, each arm wags inoculated with variolous matter. More inflammation than from the vac= ¢ine inoculation arofe in a few days, with fmall tumors, which fuppurated: the parts oculated remained fore for more than a fortnight, but no feverifh fymptoms ever ap= peared, 5. G. P. a boy 12 years of age, who had gone through the fmall-pox ten years before, was inoculated in one arm with recent vaccine matter, which had been dried on 4 lancet, and was moiftened juft before it was inferted. The day fol- fowing not fo much as a red {pot of the part inoculated was feen, nor had there been any uneafy fenfation. He was — therefore moculated a fecond time, but with fluid » bi v0 aged from a patient. ~ The day after the fecond incculation an itching fenfation of the punctured part-was complained of, which continued — ‘for two or three days. The part punétured had a {mall red élevated fpot upon it the day after the inoculation, which — grew gradually larger for four or five days, and became a — little phlegmonic tumor, buat without any red furrounding’ — areola. In a few days the little {welling fubfided, but a red j and rather fore fpot remained for a week longer. No diforder 4 of the whole conftitution was perceived. 6. Dr. Woodville inoculated me if one arm with vaccine — lymph Experiments ref; eting the Vaccine Difeafe. 323 lymph from a fubje& prefent. The punétured part fmarted a little all the remainder of the day of the inoculation, and alfo the day following. In twenty-four hours a red fpot on the inoculated part was feen exaétly like that which is often feen in the fame time when either the vaccine or variolous infection has taken effeéty and which increafed for another day ; but after this the rednefs vanifhed, and no fore was left. .I once accidentally punctured the back of my hand with a lancet which had fluid vaccine matter upon it. The con fequence was, a circumfcribed, very fmall, red, hard tumor: this remained for a fortnight, then fuppurated, and after- wards burft. The part foon healed, but left a very fmall fuperficial cicatrix. As belonging to this head, I mention, that I ie feen fe« veral inftances of nurfes having fmall, red, conical tumors on their lips and cheeks, and fometimes hands; evidently from the application of cow-pox matter of the children under their care during the vaccine inoculation. Thefe little tumors fometimes remained for feveral weeks, and a particle of pus was formed in them: they never were attended by any fever fymptoms, nor by any furrounding erythematous areola.—I here fpeak of nurfes who had long before pafled through the fmall-pox. ‘Ihave no hefitatton. to refer the following cafes to this head of unfufceptibility of taking the cow-pox to having pre- vioufly gone through the fmall-pox. A fervant of Thomas King, Efg. about 18 years of age, was brought up during his infaney under circumftances in which he could get no teflimony to his having had, or not having had, the fmall-pox. Not having undergone this dif- eafe to his own knowledge, it was thought advifeable, in order to refift the fmall-pox, with which his fellow-fervant was feized, to inoculate him for the cow-pox. This I did on Thurfday the 23d of March, in one, arm with matter on a lancet, and in the other with dried matter on a bit of thread. 4th Day, Sunday 26. The parts inoculated had {marted Vou. lV. % for 318 Progre/s of the Vaccine Inoculation, and for the two firft days, and they now were red and a little elevated, as if the infection had taken effect. 6th Day, Tuefday 28. Inflammation had almoft en» tively gone off: inoculated a fecond time in both arms with niatter from a different patient. 3d Day of fecond Inoculation, Thurfday 30. Punétured parts appeared inflamed. 6th Day, Sunday April 2, Inflammation had difap- peared. Inoculated a third time with limpid fluid: matter from a patient prefent, and with which matter I had excited the vaccine difeafe in feveral perfons. 4th Day of third Inoculation, Friday April 7.. The parts inoculated had inflamed and felt painful for two or three days, but were now well.—Ino¢ulated him a fourth time with fmail-pox matter in both arms. A little inflammation arofe, but nothing more. This young man frequently vifited hig fellow-fervant in the fmall-pox, and fhook hands with him, at the Small-pox Hofpital, while under my care for the cow-pox inoculation. In this cafe, either the fmall-pox had already affected the _conflitution, or fome other difpofition exifted, rendering it equally unfufceptible of the fmall-pox and cow-pox, From Dr. Mitche!l of Chatham, whofe report is-now be- fore me, 1 learn, that there were feveral inftances of foldiers to whom the cow-pox could not be communicated ; and. al- though they had no recolleétion themfelves of having had the fmall-pox, it was molt probable they had pafled through it. If I had feen any cafe of genuine cow-pox puftule and fpecific fever in a confiitution which had previoufly fuffered the fmall-pox, I fhould have related it; but.I onght to men- tion that fuch.a cafe has fallen under the obfervation of Dr.» Woodville, (Reports, p. 52 and 143.) I thall never obje& , ~ to the teflimony of fo experienced a phyfician without moré than ufual confideration ; but I cannot avoid here obferving, that the evidence in his cafe, of the patient having had the fmall-pox when a child, is merely that of the patient; and — 1 fubmit Experimenis refpeGing the Vaccine Difeafe. 443 YT fubmit*to Dr. Woodville, whether or not that evidence is admiflible to build upon, now that we have the above un- equivocal contravening cafes of the faét afferted. But I trutt the Doétor will be lefs tenacious of this inftance, as he him- felf tells us that he failed to excite the vaccine difeafe by inoculating feveral patients who were recovering from the natural fmall-pox. (Reports, p. 144.) Whatever impreffion the above inftances may have made on my own mind, Ido think they will produce conviftion in the mind of every practitioner, that it is a law of the human animal ceconomy to be rendered unfufceptible of the cow-pox fever and frecific pufiule by undergoing the /mall-pox. Hence I find that my expectation of the hands of phyfic being ftrengthened by the poffeffion of a fure means of exciting an innocent fever is not realifed, (Inquiry, p. 815) but I feel fome confolation from the profpe& of the new incculation being more fpeedily introduced by the removal of one ob- ftacle, viz. the fears of many perfons, who have already paffed through the fmall-pox, that they would be liable to the cow-pox, if the diffufion of the mfection of it became extenfive by the vaccine inoculation. Another advantage fuggefted in my Inguiry, p. 92, is now, I think, greatly con- firmed ; namely, an advantage’ for thofe who are not certain whether or not they have bad the fmall-pox, but poffz/s fo great a dread of this difeafe as not io be able to fubmit to inoculation for it. 1 congratulate fuch perfons on the dif- covery of a teft to which I apprehend the more timorous minds will fubmit: for if the /pecific puflule and fever do not take place from the inoculation of the cow-pox poifon, they may be aflured, that either they have already pafled through the fmall-pox, or that their conftitutions are not fufceptible of it. It now feems to me, that the following fats are eftablifhed on the ground of experience :— I. A conjflitution which has undergone the fmall-pox, is unfufceptible-of again undergoing this difeafe. ya Il. A / a a eee 224 Progrefs of the Vaccine Inoculation, and Il. A conftitution which bas not undergone the Jmall-tox, but which has undergone the cow-pox, is unfu dag geo of un- dergoing the fmall-pox. III. A conflitution which has not undergone the cow-pox, but which has undergone the fmall-pox, is unfufceptible of undergoing the cow-pox. Now, if the variolous poifon deftroys the fufceptibility of the conftitution to the future agency of this poifon, in the refpect of its producing the fmall-pox; and if the cow-pox poifon deftroys the fufceptibility of the conftitution to the future agency of the variolous poifon, in the refpeé of its pro- ducing the fmall-pox; and if the variolous poifon deftroys the fufceptibility of the conftitution to the future agency of the vaccine poifon, in the refpeét of its producing the cow- pox ; it feems demonftrated, that the fame ftate of unfufcepti- bility of the conftitution, with refpeét to the future agency of the variolous poifon, is produced equally by the agency of the variolous poifon, and by the vaccine poifon. But if the va- riolous poifon produces unfufceptibility of the conftitution to the future agency of the vaccine poifon, and the vaccine poi- fon produces unfufceptibility to the future agency of the va- riolous poifon, it feems alfo demonftrable, that the following 4th propofition is true; viz. IV. A conflitution which bas undergone the vaccine difeafe, as unfufceptible of again undergoing that difeafe from the agen- cy of the vaccine poifon: becaufe a ftate of unfufceptibility, with refpeét to the agency of the variolous poifon, is pro- duced by the vaccine poifon (2d propo/:); anda ftate of unfufceptibility, with refpe&t to the agency of the vaccine poifon, is produced by the variolous poifon (3d propo/:) : but the ftate of the conftitution being the fame in the two cafes, whether it be produced by the variolous or vaccine poifon, with refpe& to unfufceptibility, it feems inevitably, in courfe, that unfufceptibility of the conftitution to the fu- ture agency of the vaccine poifon is produced by the vaccine difeafe : ' Experiments refpetting the Vaccine Difeafe. 325 difeafe : and the demonftration in courfe could be given of propofition 1, on the ground of the 2d and 3d propofition, that unfufceptibility of the conftitution to the agency of the variolous poifon is produced by the variolous difeafe, if this were not already proved by abundant experience. At a fu- ture time, however, I fhall relate the obfervations and expe- riments to confirm this 2 prior? conclufion; 1ft, becaufe thefe proofs will increafe the validity of the 3d propofition ; and 2dly, becaufe I do not mean to offer this demonftration as infallible, like mathematical. From the preceding reafoning it may be imagined, that I confider the cow-pox and fmall-pox as only varieties of the fame fpecies of difeafe ; and that therefore the name variola vaccina is appropriate, although I endeavoured to {how that: it was unjuft, and tended to miflead, by giving erroneous notions, (Inquiry, p. 108)m But it muft here enter into our: contemplation, that the fame ftate of an animal or other fub- fiance, in a certain refpeét, may be produced by very differ- ent things; and the phenomena attending their agency may _ be very different from one another, It is fo in the inftances under confideration ; and further, in order to eftablith refem- bling things to be varieties of the fame frecies, we ought to be able to trace them to one common origin, or to fhow that they all agree in what fhould be reckoned effential pro- perties. Now hitherto it has not appeared that the cow- pox has arifen from the fmall-pox, or the fmall-pox from the cow-pox. If it be faid, that in fome of the eruptive in- ftances of the cow-pox, the puftules could not be dittinguith- ed from the {mall-pox, it fhould be confidered that it has not been yet fhown, that in any cafe the fma!l-pox has changed into the cow-pox ;—that the cow is fufceptible by inoculation of the human matter of the cow-pox, but not of the fmall-pox ; and that the puftules refembling the {mall- pox, which occur in the cow-pox, afford matter which, I be- : lieve, produces in fome cafes (if not,‘ perhaps, in fo wreat a proportion as originally) the cow-pox in its ufual mild way, ¥ 3 Ule, ' 396 Progrefs of the Vaccine Inoculation, Be. viz. a pufule in the inoculated part only, and a flight fever, Hence | humbly ai of opinion, but fubmit the queftion to the decifion of fcholars, that the ufe of the denomination va- riola vaccina is a tranigreflion of the law in philology, and - repugnant to found logic. ‘ Extended as this paper is, much beyond the limits pro- pofed, I cannot confine to myfelf the gratification from the reports of the zew inoculation. 1 fhall only mention, how- ever, one or two of them. The fenfation excited on the Continent, by the vaccine pradlice, has been much more confiderable than in‘our own ifland, as I learned fir(t from Dr. Marcet, and fince by a letter from Dr. Pefchier.. At Vienna Dr. Ferro inoculated two of his own: children with vaccine matter which I tranfmitted: and next, Dr. De Carro imo- culated two of his own cliildren. An ‘accurate journal of: thefe laft cafes was kept by Dr. D@Carro, which he has had the complaifance to communicate to me. The above pa- tiénts had the difeafe in the ufwal mild way,’ and were fub- fequently inoculated for the fmall-pox, but without effet. Dr. Frank, it is expected, will adopt the vaccine moculas tion; as it appears will be generally done at Vienna. often fend matter on a thread, which is to ‘be kept for a long time, in a bottle filled with quite dry hydrogen ‘or nitro- gen gas. I fhall foon have reports from Portugal, and other parts of the Continent. In Scotland the new inoculation has not been lefs fucceff- fal. Dr. Anderfon, of Leith, informs me he has inoculated above 80 perfons—that Dr. Duncan and others have begun —— the pra’ ice at Edinburgh; and that it has been bis mars. in Dundee, Paifley, and Dalkeith. If the vaccine inoculation proceed with equal mildnefs as “¥t has done the laft four months, doubtlefs the variolous in- cifion mu‘ in no remote period be fuperfeded. And iffuch — an event {hould take place, pofterity will behold with amaze-' ~ ment the prejudices and inattention of their predeceflors to ‘ | the application of a fact in pradtice, by which’a formidable’ _ re and ‘ Boundaries between Europe and Afia. ; 327 and loathfome difeafe was extinguifhed—a fa well known, time immemorial, to almoft every farmer in half a dozen counties of England, but nezlested till Jenner had the cou- rage to indicate the advantages of it to fociety. If I were to name a para!lel inftance of inattention or prejudice, it fhould be the negleét of inoculation for the fmall-pox, till it was in- troduced into England from Conftantinople; although it had been practifed, time immemorial, in the Barozzo moun- tains, on the frontiers of Gallicia, in the fame rude manner as it is at this day *. . Sil Se SS XVIIT. Query refpecting the natural Boundaries between Europe and Afia. To the Editor of the Philofophical Magazine. SIR, Tue variety of ufeful geographical communications in -your valuable feientific mifcellany, encourages me to hope that fome of your correfpondents may be able to inform me of what many of the geographical publications, to which I have had recourfe, give no fatisfactory account: it is, What are the boundaries-between Hurope and Afia? The laft edi- tion of the Encyclopedia Britannica, to my great furprife, gives nothing but a firing of contradictions, Under the ar- ticle O4y, that river is faid to form the boundary between ‘Europe and Afia; yet, in the wretched maps given in this expenfive work, the range of mountains known by the name of Oural is marked as the boundary. either are the Qural mountains mentioned at all m their proper place;-but, under the article Mountaim, ‘‘ the Ouralic chain is faid to forma t * This intelligence was communicated to me by a Portuguefe noble- man, whofe opportunities of information and -accuracy authorife me to mention the faét ;-but an attefted account from fome of the inhab.tants is intended for me. Sce alfo a book written by Yacobus a Ca/iro Sarmento. : Y4 natural — as 328 Boundaries between Europe and A/ia. natural boundary between Europe and Afia.” And in Vol, VII. p. 39, when enumerating the boundaries of Europe, it is faid to be * feparated from Afia in part by the Archipe- lago, as alfo by the Black Sea, then by the river Don till it comes near the river Volga or Wolga, and then it is parted from Afia by this laft, and afterwards by the river Oby.” The greateft inftance of inaccuracy, however, is when, enumerating the boundaries of Afia, Vol. IT. p. 393, it is faid to be “‘ feparated from Europe by the Mediterranean Sea, the Archipelago, the Black Sea, the Palus Meotis, the Don, and the Dwina, which fall into the White Sea.”” Such are the contradictions to be met with in that heterogeneous, though in many inftances juftly celebrated work. The ga- zetteers of Watfon, Salmon, and Brookes, uniformly contra- dict themfelves, defcribing the river Oby as being the boun- dary between thefe two quarters of the world, and their maps reprefenting the chain of Oural mountains as the boundary, It is not fo much to be wondered at in ga- zetteers, which are, generally {peaking, catchpenny publica- tions, fervilely copying from each other, even their very faults, except Crutwell’s lately publifhed, and an excellent little pocket one, Peacock’s: it is, however, to be regretted, that the editor of that moft ufeful and excellent geographical grammar, Guthrie’s I mean, has alfo fallen into this error. If any of your correfpondents will inform me how this matter is, it will be confidered as a favour by one who has , already received much entertainment and jnformation from _ the Philofophical Magazine, Auguft 12, 1799. L. M. P.S. There is a fimilar miftake to be found in moft geo- graphical defcriptions of Ireland; the county of Clare being enumerated amongtt the counties of Munfter, and the map reprefenting it-as part of the province of Connaught, which certainly appears its moft natural appropriation, , 1 329. 2 INTELLIGENCE, AND MISCELLANEOUS ARTICLES. MINERALOGICAL SOCIETY OF JENA. Tx the public fitting of the Mineralogical Society of Jena, held on the 26th of May at the Ducal Palace, Mr. Bodo, from Hungary, read a paper to prove that organifation can- not be denied to any natural body, and that the divifion into organifed and unorganifed is confequently inadmiffible. M. Stark, the fecretary, read a paper fent in by M. Mihalik, of Dopfchau in Hungary, on the following queftion : Whe- ther mineralogy could exift as a fcience without the help of chemiftry ?— Dr. Bonzel propofed, that various minerals now arranged under one general name, fhould in future, on account of their peculiar marks of difference, be feparated in the fyftem, and be diftinguifhed by particular names. Thus, for example, that the red zeolite, from Faffa in the Tyrol, fhould be called Faffaite, to diftinguith it from. the ‘seal Icelandic zeolite; and that the fchorl, from Oifans in Dauphiné, fhould be called Oifanite, to diftinguifh it froma that of Thum in Saxony. LITERARY NEWS. That moft learned, indefatigable, and amiable cultivator of feience, R. Kirwan, Efq. is now in London, where he has been for the laft three months. With fincere pleafure we can announce that this revered veteran is printing and pre- paring for the prefs three valuable works :— ~ 1. A Treatife on the Analyfis of Mineral Waters: a moft difficult and nice fubjeét, and which will require aJl Mr. Kirwan’s mental powers. and knowledge to treat of fuccefs- fully. 330 Netural Hiffory. fully. ers has been done on this fubjet fince the new fyftem of chemiftry has been generally adopted. 2. A Memoir on the interefting and fundamental Part of Chemical Science, the precife Ouailitees of Menitrua and Bafes contained in the double Salts with alkaline, earthy, and metallic Bales: whence may be deduced’ the precife Forces of the Affinities of Bodies. 3- A work on Geology; which will be made not only to accord with the Mofaic Do‘trine, but to confirm it greatly. Of this philofopher permit us to indulge in the wifh— Sero in ceelum redeat. NATURAL HISTORY. The following inftance of the fagacity of the elephant, which is taken from a late French Journal, may ferve as an additional confirmation of what has been fo often repeated by various authors both ancient and modern :— “* A fentinel belonging to the menagerie at Paris, anxious to diicharge his duty, was extremely careful, every time he ‘mounted betas near the elephants, to defire the fpe&ators not to give them. any thing to eat. This condu& was not much calculated to procure him any friendthip from the ele- phants. The female, in particular, beheld him with a very unfavourable eye, and had feveral times endeavoured to cor- rect his unwelcome interference by befprinkling his head with water from her trunk. One day, when a great num- ber of people were colleXed to view thefe animals, the op- portunity feemed convenient for receiving, unperceived, a fmall bit of bread; but the rigorous fentinel was on duty. The female, however, placed herfelf before him, watched all his'geftures, and, the moment he opened his mouth to give his ufual admonition to the company, difcharged in his face a large {trearn of water. A general laugh enfued ; but the fentinel having calmly wiped ‘his face, ftoud a little to ene fide, and continued as vigilant as before, Soon after ss ‘ he Introdu&tion of the Camel at the Cape. 33t he found himfelf under the neceflity of repeating his adino- nition to the fpectators not to give the elephants any things but no fooner had he done fo than the female laid hold of his mufket, twirled it round in her trunk, trod it under her feet, and did not reftore it until fhe had twifted it inio the form of a fcrew.” INTRODUCTION OF THE CAMEL AT THE CAPE CF Goop Hops. Notwithflanding the great number of travellers who have attempted to penetrate into the interior part of Africa by the way of the Cape of Good Hope, the diftrias left unexplored are immenfe when, compared to thofe which have been vi- fited. One of the greateft obfiacles to travelling in thefe wild and parched regions, is the want of proper beafls of burthen ; for it is well known that cattle cannot long endure thirf, and that numbers of them employed on that feryice by travellers have died by the way, and thereby rendered their attempts to proceed farther ufelefs. This fa& mufi be well known to thofe who have read Vaillant’s Travels. Pro- feflor Heeren of Gottingen propofes therefore,-in order to remove this difficulty, the introduction of the camel at the Cape of Good Hope. <“‘ There can be no doubi,”’ fays he, that this animal would thrive there, as the climate is ex- aGtly the fame as that of the countries where it is now found. It would no doubt fucceed as well in the latitude of 35° Se as the lat. of 35° N. in Syria. The exploring of the interior parts of Africa is not the only advantage which might be derived from the introduction of the camel ‘at the Cape: of what utility would fuch a beaft of burden be to the plan- ters, many of whom live at a great diftance from the Cape town, and can at prefent fend their produéctions thither in no other manner than in waggons drawn by four oxen! | The principal point, however, would be the opening a com- mercial intercourfe with the interior part of the country. It ¢annot be doubted that the fouthern extremity of Africa is wpe 8 more 33% Animal Eleéiricity. more productive than the northern, and why might not the Cape be the centre of a trade which in future may become very extenfive? But without the affiftance of the camel it could never be attempted. The prefent period is the more favourable for putting this propofal in execution, as the Cape is now in the poffeffion of Great Britain ; and even if it fhould be given up at the next peace, the Britifh government would by this fervice to the colony raife a monument worthy of its dignity: the expence of tranfporting a few camels from Mogador would be very trifling.””—We agree in opinion with Profeffor Heeren, and think his propofal well worth atten- tion. | ANIMAL ELECTRICITY. Dr. Chladni, well known by his difcoveries in regard to found, has lately announced the following obfervation on animal electricity, which we here give in his own words: ‘¢ It might be conjectured, when electricity manifetts itfelf in antmals, that it would be equally diffufed throughout the whole body on account of the conduéling power of the in- terior parts ; yet we are taught by experience, that the oppo- fite kinds of electricity take place in the torpedo as well as in cats, though in a lefs degree; and perhaps the cafe is the fame in other animals. Some years ago I remarked that a eat which had been. rendered eleétric by ftroking with the dry hand; efpecially when lying near the fire on dry days in winter, exhibited oppofite kinds of ele€tricity; and that the principal feat of the one was in the head, and of the other. in the back, about two inches from the tail. This pheno- menon appeared above all when the animal was upon a chair ftuffed with hair, and covered with a woollen cloth, by which it was completely infulated. When the head, and in par- ticular the tip of the nofe, or of one of the ears, was touched by the finger, there appeared a {mall eleétric fpark; the cafe was the fame when the extremity of the back was touched ; and in this manner {parks could be drawn alternately from. the anterior and pofterior parts of the body in the fame man-, ner we Ja Meteorology. 333 ‘nér as fparks can be drawn alternately from an infulated charged jar. I afterwards obferved the fame thing in an- other cat; but, as at that time I paid little attention to this part of philofophy, and fuppofed that the exiftence of the ‘oppofite kinds of electricity in animals might have been known, I made no farther experiments, and could not de- termine which of thefe ele“tricities was negative and which pofitive. I leave it, therefore, to others to examine this phe- nomenon with more accuracy.” METEOROLOGY. A very fingular work was publifhed laft year at Liegnitz in Silefia, entitled pbhorifms ref/peéting the Influence of War on the Atmofphere, Weather and Fertility of the Earth. Among the author’s obfervations are the following: If a cubic foot of gun-powder, when it explodes, exercifes a force equal to twenty-nine millions of pounds, it by thefe means produces a great change in, the elafticity of the air; the whole mafs of the atmofphere, within a large circumference, is violently torn, and billows of air are produced, which roll themfelyes upwards and agitate the vapours contained in them. It cannot therefore be denied that the difcharging of fire-arms and cannon during battles and fieges, and even at great reviews, muft have an influence on the atmofphere, arid on the ftate of the clouds and weather. He quotes inftances in the time of the feven years war, of clouds and vapours being difperfed by the explofions of the cannon; and afferts that, during his travels through the Tyrol, he faw on feveral oceafions, to ufe his own expreffion, the clouds “ fhot dead.” He obferved in the neighbourhood of Liegnitz, while the ‘Tegiment of Wartenfleben were going through their exercifé, that the clouds were broken by the explofions, and that the murmuring of the wind, and the agitation of the leaves of the trees, and the fmall feathers fufpended from any body, were fometimes ftronger, fometimes weaker, according as the troops fired by battalions or companies. The barometer 7 rafe ' 334 Black Paint.—Sugar from Beet-root. rofe and fell at each explofion ; and water in a veffel, at the diftance of five hundred paces, was violently agitated. There have been inftances of the noife of heavy cannonades, in the Jaft and prefent war, being heard at the diftance of more than forty miles. Nay, the thunder of cannon penetrates even into the interior parts of the earth, and to the bottom of the fea, fo that whales and herrings have been frightened away to the diftance of two hundred miles, The author, from thefe principles, endeavours to account for certain fingu- Iarities which prevailed in the weather in fome parts of Ger- many in the year 17973; and to fhew that the quantity of gun-powder fired in the time of war may havea fenfible effe& on the fertility of gardens and fields. In the feyen years war above a miilion of pounds of powder were fired off in Europe; and it may with certainty pe affirmed that no lefs a quantity has been confumed in the prefent war avainft the French. NEW BASIS FOR BLACK PAINT, A moft excellent bafis for biack paint has been difeovered in the Lead-mines of Nant Gwider, in the Vale of Conway, by Mr. Goodwin of Llanrooft, proprietor of feveral mines, of which a defcription and analyfis will be given in fome fu- ture number of the Philofophical Magazine, tegether with that of feveral other fubftances he has difcovered in North Wales, and which it is prefumed will be of confiderable utility. SUGAR FROM THE BEET-ROOT. ‘Profeffor Géttling, of Jena, has announced a fmall work, which he intends to publifh foon, on the preparation of 3 fugar from the beet-root. The Profeflor in his profpectus obferves, that the various kinds of beet with which he made experiments, mutt be treated im a quite different manner from _ the fugar-cane, or the method employed by Margraaf, in or- © der to obtain from them good fugar. In regard to the quan- j tity of fugar which they produce, he found very little varia ‘ tion, Potatoe Size.-—Deaths. 335 Sr - FOO EE a ee fy tion, Some have faid that 100 pounds of roots are fufficient for eight pounds of fugar; but Profeffor Gattling could ob- tain from 100 pounds of roots no more than two pounds and ahalf. As the Profeffor has promifed to give a full account : of the procefs in his pamphlet, tt will no doubt be interefting : to thofe who wifh to make experiments on this fubject. N 4 ° SIZE MADE OF POTATOES. One of the beneficial ufes of potatoes, not perhaps ge- _ neraily known, is, that the flarch of them, quite frefh, and wafhed only once, may be employed to make fize, which, - mixed with chalk, and diluted in a little water, forms a very beautiful and good white for ceilings. This fize has no fmell ; while animal fize, which putrefies fo readily, always exhales a very difagreeable odour. That of potatoes, as it is very little fubject to putretaciion, appears from experience to be more durable in tenacity and whitenefs ; and for white- wathing fhould be preferred to animal fize, the decompofi- tion of which is always accompanied with unhealthful ex. f halations. ff DEATHS. _ On the 2oth of April, at Leyden, David Van Royen, Pro- _ feflor of Botany in that Univerfity, in the 7oth year of his - age. On the 7th of this month, at his houfe in Newman-frrect, John Bacon, Efqg. R.A. the well-known fculptor. He was _ a native of Southwark, and, when a child, diftinguifhed him- felt by moulding figures in clay, and very early in life ob- _ tained prizes from the Academy. On Thurfday the 22d inftant, in the 4gth year of his age, - Benjamin Thomas Pouncy, engraver; an artift of the firft eminence in his profeflion. He was the. brother-in- law and moft diftinguithed of the difciples of Woollett, with whofe vigour and richnefs of flyle he has with peculiar fe- Hicity united the freedom and fimplicity of Vivares; “ and, with 336 ' Deaths. with a mafter’s hand and poet’s fire,”’ has fecured to frimfelf the praife of originality, by blending both with his own view of Nature. To enumerate his engravings, and comment on them in the detail, would be more than the prefent difpofal of the writer’s time will permit; yet the mention of a few of their leading traits is at leaft due to the merits and the memory of fo excellent an artift. Freedom, boldnefs, and an happy imitation of the wild forms of inartificial Nature are among their diftinguifhing features. The drawing of his trees in particular; his difcrimination of their feveral cha- racters; his thorough knowledge of their various modes of growth, combined with a mode.of expreffion arifing fpon- taneoufly out of his fubject, have perhaps never been ex- celled. Among the rude and artlefs landfcapes of the South-fea iflands, or the wild and luxuriant forms of Jake _ and foreft feenery, his etching-tool and his fancy would revel delighted, and communicate to every cultivated eye a corre- fponding pleafure. With fuch claims to fuperior art, men of difcernment will lament that it was the lot of Pouncy to be obliged to trammel his talents, and employ a confiderable portion of his time in engraving fac-/imiles from the pages of Doomfday-book ; in tracing the Spanifh lines before Gi- braltar; and on other fubjects that required merely care, and the exercife of a certain regular mathematical ability he did not naturally poffefs. On the whole, it ‘may be faid of his works, which are chiefly after Farington, Hearne, Smith, and Wilfon, that they will continue to be admired wherever legitimate art and true tafte are not obfcured by the falfe glitter fo much the fafhion of the day; and that, in private life, the hofpitality of his manners, the compafs of his know- ~ ledge, the liberality of his fentiments, and the goodnefs of ~ his heart, will long be remembered with regret by thofe pe who had the happinefs of being intimately known to him. 7 ‘ i i} Log THE PHILOSOPHICAL MAGAZINE, SEPTEMBER 179Q: 4 ——_—— 1. On the gradual Changes in Temperature and Soil which take place in different Climates, with an Enquiry into the Casfe of thofe Changes. By the Abbé Mann”*: V aniovus authors, both ancient and modern, have written on the fubject of this Differtation, but merely in a eurfory manner ; one only, Dr. Hugh Williamfon, an Ame~ rican phyfician, has made it an object of particular atten- tion; but what he has faid relates only to North America, and is comprehended in a very fhort paper publifhed in the Philofophical Tranfactions of Philadelphia for 1777. Ithas Jong appeared to me interefting enough to require farther and more accurate examination; but before I enter into any tefearch refpeGting the caufes of thofe changes of tempera- ture and foil, obferved in different countries during a long feries of ages, it feems to be neceffary firft to prove, by au- thentic teflimony, that thefe changes have aCtually taken place. This Differtation divides itfelf naturally into two parts. In the firft I fhall colleé all the information of an- Le From the Tranfadtions of the Eleétoral Academy of Sciences at Man- heim, Vol, VI. Vot. IV.’ oh cient 438 On the Changes of Temterature and Soil cient authors [ have been able to find on the ftate of the — temperature and foil in their time in Gaul, Germany, Pan- nonia, Thrace, Meefia, | acia, and the European part of Scythia. As moft of thefe writers, however, when they fpeak of the climate of thofe countries, exprefs themfelves more or lefs in an almoft unintelligible manner, and nearly in the fame words, it would be fuperfluous to quote, at full Jength, all the paffages I have colleéted on the fubje&. I fhall therefore content myfelf with giving, in regular order, the fubftance of all the circumflances they have communi- cated to us if regard to the climate of the above countries ; and in the fecond part I fhall briefly enquire into the phyfical caufes which, in the courfe of feveral centuries, may have gradually contributed to produce thefe changes. T. Proofs of the Change of Temperature and Soil in the Climates of Europe. We are told by Herodotus, more than once, that in the European part of Scythia, on the Palus Meotis, the winter continued eight months every year with almoft infupport- ‘able feverity; and that the countries farther towards the north were on that account uninhabitable: he adds, that the other four months, called the fummer, were alfo exceed- ingly cold. Now this country lies between the 44th and soth degree of north latitude, and we know at prefent that aothing of the like kind has:taken place there for a long time. Czfar, Virgil, Diodorus Siculus, Ovid, Strabo, Pom~ ponius Mela, Seneca, Petronius, Pliny the naturalift, Sta- tius, Herodian, and Juftin, all fpeak in the fame manner of the infupportable cold of the winter in different parts lying in the fame latitude of from 44 to 50 degrees between Gaul and the Euxine Sea. They quote fo many and fo evident effects of this winter cold, that it is not poffible to afcribe their deferiptions to the manner of life they were accuftomed to in the warmer diftriéts of Italy, Greece, or Afia. The deferiptions which they unanimoufly give, would ag: prefent gubich take place in different Climates. $39 prefent fuit thofe countries which lie between 56 degrees of Jatitude and the polar circle; and in fome refpects they feem to exceed the cold of the winter in Sweden and Nor- way. In order to fee realifed at prefent the defcriptions which the ancierits have givert of the climate of the middle part of Europe in their time, it would be neceflary to vifit Lapland, Siberia, and thofe regions of America lying to the north of Hudfon’s Bay, where the ftate of the climate is the fame as that 2000 years ago on the banks of the Rhine and the Danube, the Palus Meotis, the Dnieper, and the Don. The fir(t effect, uniformly mentioned by the ancients, of the extraardinary cold of the winter in that whole part of Europe between the 44th and foth degree of latitude is, that all the feas, lakes and rivers comencned in thofe dif- triéts were continually frozen in winter, fo that armies of barbarians, Scythians and Sarmatians, in order that they might plunder the more fouthern countries, paffed with their horfes, waggons and baggage over the ice, which they be- ftrewed with ftraw to prevent their fliding. This is ex prefsly afferted by Herodotus, Virgil, Ovid, and Strabo, of the European part of Scythia, Dacia, ahd Thrace, all coun- tries which lay in a northern and weftern direction from the Palus Mentis and the Euxine Sea. The fame thing is af- ferted by Diodorus Siculus, Seneca, Pliny the younger, Florus, Herodian, Ammianus Marcellirnus, Fernandes the Goth, and Xiphilinus the abridger of Dio Caffius, in regard to the rivers and lakes of Pannonia, Germany, and Gaul. They mark the times when thefe armies paffed the ice, and the wars whith they then carried on; fd that no doubt can be entertained in regard to teflimorly fo urianimous and au- thentic. Herodotus fays, that the Stythians in this manner over-ran, during winter, all the neighbouring countries as far as India; and we are told by Strabo, tha! Neoptolemus, the general of Mithridates, beat the barbarians in winter with an army of cavalry, at a place which in fummer had been the {cene of a naval battle. In the Treatife on Rivers, Za afcribed 340 On-the Changes of Témperature and Soil afcribed to Plutarch, it is faid, the Thermodon, a Scytliiart river, froze even in fummer3; a circumftance which never happens at prefent in regard to the rivers of Siberia, Lap- land, and Greenland. Ovid tells us, that he himfelf paffed over the Pontus Euxinus on the ice. People, adds he, will fearcely believe me: Sed cum fint praemia falfi Nulla, ratam teftis debet habcre fidem. Plutarch fays, that the preffure of this enormous mafs of ice againft the fides of fhips frozen into it, crufhed them to pieces; and he mentions the inftance of a Roman fhip which had experienced that fate in the Danube. Strabo and Virgil fpeak of brafs veffels burflig by the expanfive force of the ice; and we are aflured by Virgil and Ovid, that the people in Thrace and on the Danube cut the wine with axes, and diftributed it in folid portions. They add, like- wife, that men’s hair and beards were often covered with ice. Stiriaque impexis indurent horrida barbis. VIRGIL, Szpe fonant moti glacie pendente capilli, Et nitet induéto candida barba gelu. Ovib. If we compare this defcription with the prefent ftate of France, Germany, Hungary, Romania, Tranfylvania, Wal- lachia, Moldavia, Bulgaria, Leffler Tartary, Podolia, and the Ukraine, it will be found that the prefent temperature of thefe countrics has no refemblance to what it was two thoufand years ago: the effects produced there every winter. - fearcely take place now once in a century, and when they occur they are confidered as extraordinary phenomena. ; From ice I fhall proceed to fnow. Herodotus, Pompo- nius Mela, and Pliny the elder, fpeak of the European part of Scythia as if its atmofphere was continually filled with fnow and fogs, which prevented the view of the neareft ob- | jects, and obfcured the light of the day. We are told by Herodotus, that this immenfe load of fnow, when it fell, made the air appear as if filled with feathers; and that for “ this which take place in different Climates. . 341 this reafon, the country was called Pferophoros. Diodorus ‘Siculus fpeaks of Celto-Scythia as covered with fnow in the winter time; and the fame thing is afferted by Florus and Petronius. Virgil, {peaking of Thrace and the countries oy both fides of the Danube, fays, that a continual winter pre- vailed in them; and that the fnow lay upon the ground fometimes to the depth of feven ells. | Sic jacet aggeribus niveis informis, et alto Terra gelu laté, feptemque affurgit in ulnas, Semper hyems, femper fpirantes frigora cauri. The picture which Ovid gives of the fnow at Tomi (in the lat. of 441) is no lefs horrid, as he tells us that it con- tinued twe years without being melted by the fun or rain; Nix jacet et jaétam nec fol pluvieve refolvunt; Et folet in multis bima manere locis. In regard to other meteorological phenomena in the Eu- ~ ropean part of Scythia and Celto-Scythia in the time of Herodotus and the following century, this hiftorian fays, that it feldom rained in the winter, becaufe at that period it feldom ceafed to fnow; and that, on the other hand, when the weather in fummer was dry and fair in Greece and Leffler Afia, it never ceafed to rain in the country of the Celto-Scy- thians: that during this feafon the heavens were always over- eaft with clouds, and that thunder, even in fummer, was very uncommon; that when it happened in winter, it was con- * fidered as a wonder, and that, in thofe feafons when it took place, earthquakes were obferyed alfo, This laft circum- ftance is indeed worthy of attention, as it ferves to confirm my conjectures refpecting the theory of the earth. Diodorus Siculus, Tacitus, and Ovid, when they fpeak of Gaul, Germany, and Thrace, take notice of the prodigious force of the wind which preyailed in thefe,countries in their time and during the preceding centuries. Thefe winds raifed - even ftones and men from the earth ; carried away the roofs of houfes; tore up trees by the roots, and overturned turrets Z'3 and $42 On the Changes of Temperature and Soil and houfes. Such effects of the wind are indeed obferved at prefent, particularly in the countries on the Northern Sea and the Bay of Bifcay, but feldom in thofe parts of the Con- tinent fpoken of by the ancients. Varro, Diodorus Siculus, Ovid, Pomponius Mela, Seneca, Petronius, Pliny the elder, Tacitus, Appian, Dio Caffius, and Herodian, all agree in faying that the feverity of the climate and weather which in their time prevailed in Gaul, Germany, Pannonia, Thrace, Meefia, and Dacia, would hardly admit either vines, olives, or any kind of fruit-trees ; and that, in cultivating them, it was neceffary to cover them with dung or with earth to preferve them throughout the winter. Tacitus, however, adds, that thefe countries pro- duced, in abundance, various kinds of grain, where the peo- ple gave themfelves the trouble to improve and manure their fields by means of marl or chalk, which defiroyed the cold and the moifture. This circumftance.is exprefsly remarked by Varro: Agros fiercorarent candida foffitia creta. He af- ‘terwards adds, that in thefe countries there was neither rock falt nor fea falt: the preparation of the latter required a ftronger heat than exifted in thofe climates *. The inha-* bitants fupplied the want ot falt by faline athes from certain kinds of wood burnt for that purpofe, and which were drenched with falt water. Pliny and Tacitus give the fame account. It is obferved hy Herodotus, Strabo, and Tacitus, that the oxen in the European part of Scythia and the country of the Celto-Scythians had no horns, or horns exceedingly fmall; which they afcribed to the feverity of the cald and the. climate. Herodotus confirms this idea in a negative * This, indeed, proves nothing in regard to the climate; but it fhews the want of knowledge and indvftry. The paffage in Varro De Re Ruj- #ea,i. 7. is as follows; Ubi falem nec foffitium nec maritimum haberent ; Sed ex quibufdqn lignis carbonibus falfis pro eo uterentur. It is probable that they boiled their falt, as was done in former times in fome parts of Europe; that is, poured the faline liquor over glowing pieces of wood, and colleéted the falt which adhered to the charcoal. G, : manner — ee. ‘which take place in different Climates. 343 manner by the teftimony of Homer, who fays in the Odyffey, that in Lybia the lambs had horns from their birth, owing to the great heat. Strabo, as a proof of the great cold which prevailed in the country now ‘called the Ukraine, obferves that it produced no aff s; animals, fays he, which cannot endure the cold: and he adds, that the horfes there were extremely fmall. But nothing, indeed, is more aftonifhing than the teflimony of Paufanias, who fays expre(sly, that in Thrace there were in his time bears and wild fwine of a white colour. Such animals at prefent are found only in the remoteft parts of the north, on the other fide of the polar circle. We are told by Virgil, Ovid, and Pomponius Mela, that the inhabitants of the European part of Scythia and Thrace lived, during the whole winter, under the earth (as the Laplanders do at prefent); that they burnt large logs of wood to keep themfelves warm; that they never went abroad without being wrapped up in fkins; and that they left no part of the body uncovered but the mouth and eyes. Pomponius Mela fays, Specus aut fuffoffa babitant, | totum braccati corpus, et nifi qua vident etiam ora vefiitz. I think it of importance to point out here the boundaries of thofe countries towards the north, which the ancients eonfidered as defolate and uninhabitable on account of the great intenfity of the cold. Herodotus fays, that beyond the Melanchlini, a Sarmatian people, fo called from their black hair, there were only lakes, moraffes, and uninhabitable diftriéts as far as was then known; and we learn from Ovid that on the other fide of the Cimmerian Bofphorus, the i'a- nais, and the Scythian morafles, a cold prevatled which rendered the country uninhabitable, Bofp!orus e¢ Tuoais fuperant Seythieque paludes ; Ulterius nihil eft, mfi non bab tapile Figus This is exprefsly confirmed by geographers and hiftorians. Strabo repeats, feveral times, that all the lands towards the north of the tribes who lived on the banks of the Tanais 24 and 344 On the Changes of Temperature and Soul and the Boryfthenes were uninhabitable on account of the feverity of the cold which prevailed in them. But all that has been traced out of the banks, and even the origin of this river, does not lie beyond the 55th degree of latitude ; confequently is on the fame parallel with the northern part of England and Germany, the middle of Lithuania, and the middle of Ruffia. Between thefe two rivers Strabo places alfo the Rhoxolani, who in general are confidered as the anceftors of the Ruffians; and he adds, that all the diftri¢is farther north were uninhabitable on account ofthe cold. In another place he fays, that all the northern part of Bni- tain was very thinly peopled on account of the cold, and that he believed all the countries lying beyond it to be un- inhabited. Now no part of Great Britain extends beyond the 6oth degree of north latitude ; confequently that parallel includes all Norway, almoft the whole of Sweden, and the half of Ruffia. Thefe countries, therefore,in the time of Stra- ba, that is, about the period of Auguftus, were confidered as uninhabited. The ancients, in general, {peak of all the lands which lay beyond the 55th degree of north latitude as filled with lakes, moraffes, ice, fhow, and fogs, almoft like thofe countries to the north of Hudfon’s Bay. Thefe, in my opinion, are fufficient and unqueftionable proofs of the exceffive feverity which prevailed 2000 years ago in the climate of thofe countries of Europe lying between the latitude of 44° and 50° north latitude, and fully eftablith the difference between the ftate of their temperature in thofe periods and what it is at prefent. The more northern lands, which the ancients, on account of their unfupportable cold, confidered as uninhabitable; Iceland, Norway, Lapland, and the northern part of Ruffia and Siberia, are habitable, and inhabited at prefent, as is well known, though exceed- ingly cold. The ancients alfo {peak of effects produced by the cold of winter in Italy, Greece, Leffer Afia, &c. which at prefent are certainly unknown. The foil of the latter countries, as well as that of the ancient.Affyria, Chaldea, Palefline, _ ‘ : z ] 4 a) 7 ; A % Chas abbich take place in different Clinaiés. 348 Palefiine, the Roman part of Africa, and Spain, is at prefent -yemarkably flony, and burnt up with heat. We, however, know, that Spain in particular, about 1800 years ago, was exceedingly rich and fruitful, and abounded with all forts of provifions, which are no longer to be found in it *, It apa pears to me unneceflary to produce more proofs, as the change of the foil and fertility in all the countries bordering on the Mediterranean Sea, and which formed the richeft and moft beautiful part of the Roman empire, is admitted as a certain fact by all thofe who haye fpoken of their former and prefent ftate. It is therefore beyond a doubt, that the foil and tempera~ ture of all the lands from Spain ta India, and from the ridge of Mount Atlas to Lapland and the remote parts of the north, haye in the courfe of ages, fince the period of the oldeft hiftorical monuments {till extant to the prefent time, been gradually fubjected to a complete change, from the utmolt degree of moifture and cold, to a great degree of dry- nefs and warmth. An effect fo continued and uniform mutt 3ave fome caufe, which is equally fo itfelf. Dr. Wilhamfon afferts, that the climate of America is becoming continually milder; and he confirms it by a num- ber of facts. This effect is directly contrary te the hypo- thefis of a celebrated naturalift refpeéting the theory of the earth and the planets, who afferts, that they have been con- tinually lofing warmth fince they were firft in a flate of fu- fion, and are becoming always colder; fo that they will at length be incapable of keeping alive any animal or vege- table production +. All hiftorical and phyfigal monuments, however, prove the contrary. * The diftriéts in the neighbourhood of Toledo are deftitute of trees, on which account the heat in fummer is unfupportable, and wood in wie- ter exceédingly dear, When Martial wrote the following lines, the coun ry muft ceftainly have been in a very different flate : JE Mlas ferenus aureo fringes Tago Obfcurus umbris arborum. t This was the opinion of Buffon, Exir. _ 446 On the Changes of Temperature and Soil, &c. It is not merely in modern times, and fince the improve- ment of natural philofophy, that this change of temperature and foi} has been remarked. A great number of places, well known and defcribed by the ancients, in Palefiine, Syria, Leffer Afia, Greece, Italy, Spain, and Barbary, exhibit proofs of the changes which have taken place in the foil and tempe- Fature in the courfe of time. Every one knows their prefent dry and barren flate, which feems to be paft remedy. Itisfo contrary to that in which they were formerly, according to all the defcriptions of them left us by Greek and Roman authors, that it is impoffible for us to afcribe this difference merely to the inclination of the ancients for exaggeration * : the clear and precife facts, which various celebrated authors have mentioned refpeéting them, will not allow of fo abfurd a fuppofition. Ovid fays that, in his time, Lower Meefia, to which he was banidhed, produced neither vines nor fruit~ trees, Nam procul 4 Getico littore vitis, Nam procul a Geticis finibus arbor abeft. Strabo, who was a few years later than Ovid, {peaking of vine plants in the Thracian Bofphorus, fays, that in winter it was neceflary ta bury them under the earth in order to preferve them. Not long after, it was ohferved by Pompo- nius Mela and Pliny the elder, in {peaking of Thrace, . that there were fcarcely any fruit-trees in that country, and that in winter it was neceffary to cover them with dung. Mela adds, that the vines often grew there, but that the grapes never ripened f. Columella is the firft author who fpeaks of vines in Gaul; and he fays that the Sabines and the Ro- mans in the preceding century had procured, amidft the de- vaftation of war, more abundant crops than had been pro~ cured in his time during a ftate of perfect peace. But no- “& Voltaire pays this compliment to the authors of the Bible in regard -to Paleftine. + Vitem frequentius tolerat, fed nec ejus quidem fructus maturat ac mitigat. thing Vibration Nodes of Mujfical Strings. 349 thing in this refpe&t is more ftriking than what is obferved by Columella in regard to the changes of climate. ‘* I find,’ fays he, “ that it is the opinion of many re{pectable authors that the quality and ftate of the atmofphere become changed in the courfe of a long feries of ages: for Saferna, in that work which he has left on agriculture, infers that the ftate of the atmofphere is changed, becaufe certain diftricts, which formerly were incapable of producing vines or olives on ac- count of the continual feverity of the winter, now yield abun- dant vintages and plenty of oil by the climate having be- come milder and warmer*.’”? But it is now time that I fhould proceed to an inquiry into the caufes that produce thefe changes, the effects of which I flatter myfelf [ fhall be able to prove, [To be concluded in next Number, } II. Obfervations on the Vibration Nodes of Mufical Strings. By J.G, VoicrT of Hallet. astern. I. Divide AB, the ftring of a monochord, into any number of equal parts, for example four, by the points CDE, and place a moveable bridge at E; put on the points C,D of the ftring, and any others at pleafure, light bodies, fuch as {mall bits of paper, and draw a violin bow, rubbed with rofin, over the part EA; you wil} hear the tone correfponding to the part EA, which is to the tone of the whole ftring AB as 4:1; and all the bits of paper,. except thofe lying on the points CD,E A—.—.—.—. * Multos enim memorabiles auétores comperi perfuafum habere, longe evi fitu qualitatem coeli ftatumque mutari———-~. Nam (Saferna} co libro quem de agricultura feriptum reliquit, mutatum ceeli ftatum fie colligit, quod, que regiones antea propter hiemis affiduam violentiam nul- lam ftirpem vitis aut olee depofitam cuftodire potucrint, munc mitigato jam et intepefcente priftino frigore largiffimis olivitatibus, liberique vinde- gaiis exuberent. De Re Ruftica, Lib. i. cap. 1. + From Gren’s Journal der Phyfik, Vol. IL. part 3. i C and 348 Obfervations on the C and D, will, by the vibration of the firing, be thrown from . The points C and D are called vibration nodes. In this, and all the other experiments of this kind, the point where the bridge ftands is alfo a vibration node. II. Divide the ftring AB into a number of equat parts at pleafure, for example five; cut off, by removing the bridge to E, two of thefe parts (this number 2 and the other 5 mutt have 1 for a common divifor) ; ; place upon the points of divifion C,D, F, and any others of the ftring taken at pleafure, light bo- B dies, fuch as bits of paper; draw the violin bow over the part EA, and all CED) 2. Ff ot. ee eT the bits of paper except thofeyon C and D will then be thrown off, and you will hear a tone which is to the tone of the whole ftring as 5:2, and which correfponds to the tone of the part EA, III. Divide a firing AB into any number of equal parts, for example fix, by the points C,D,E,F,G; cut off as be- fore, by removing the bridge to I’, two parts (this number 3, and 6 the number of the parts of the whole firing, muft have a greater common divifor than 1); place upon the other four points of divifion C,D,E,G, and on any others of the firing taken at of paper 5 aia all thefe, except that at D, will be thrown down by rub- bing the bow againft FB, the part cut off by the bridge; you will alfo hear a tone correfpopding to the part FB, which is. to the tone of the whole ftring as 6: 2 or 3:1. IV. If you place upon the ftring, without cutting off any part of it by the bridge, different bits of paper in points taken at pleafure, and rub with the bow fo as to make the whole tring found, all the bits of paper will be thrown from it. This experiment will give the fame refult when you cut off in the middle the part of the ftring which a€tually founds ; for example, you may vary the fecond experiment thus :— @ ; me Divide Vibration Nodes of Mujfical Strings. 343 V. Divide the {tring AB by the points C,D,E,F, inte five equal parts ; cut off, by means of two moveable bridges, the part DE; place upon C and F, and other points of the ftring AB, {mall bits of paper: rub the CDE F bow againft ED; all the bits of paper A.—.—.—.—.—..B will be thrown off except thofe in C and F, and you will hear the tone cor- refponding to DE, which is to the tone of the whole ftring, as 5:1. From thefe few experiments, the following laws refpecting vibration nodes may be deduced :— 1. The part of the ftring apparently at reft is not perfectly fo, but only its vibration nodes. 2. The original vibrating part of the ftring, which is brought into immediate vibration by rubbing with the violin bow, has no vibration nodes; and therefore no ftring on the violin, violoncello, harp, or harpfichord, can have any. All the vibration nodes on thefe inftruments le behind the bridge. 3. For vibration nodes to be poffible, a part of the ftring _muft be apparently at reft; confequently, the number which rs} 6 exprefles the height of the tone emitted, as compared with the tone of the whole ftring = 1, muft be greater than one, and mutt therefore be exprefled by an improper fraction. ‘4. In order to determine the number of the vibration wy ik nodes of a ftring for the tone at where, as before fhewn, @ ‘muft be greater than 2, we need only reduce the fraction a : . ; , —-, which exprefles the proportional height of the tone, to its loweft terms +. and fubtract the {maller number g from the greater p: the difference p —g will be the number of the vibration nodes. This law follows very naturally from the preceding experiments. When the height of the tone to be produced is to the tone : of 360 Vibration Nodes of Mufical Strings. of the whole ftring as > a3 parts of the ftring muft be rubbed with the bow in order to produce that tone, that is, the {tring is divided into @ parts, and 4 parts muft be cut off and rubbed with the bow; therefore z—d are parts of the firing, or of the whole ftring apparently at reft, the extreme points of which are capable of producing vibration hay ay nodes; and when — is brought to its loweft expreffion, a a aA dghie tts b eae it gives a—5 vibration nodes. If ar be not in its loweft terms, let its loweft terms be 7 3 fo that am = f., and when ¢ is the greateft common divifor of 2 and 6, 2 will be = ef, and 6 = eg; therefore az—b = e (p—gq). Now, if it fhould be required to apply this law to = the number of the vibration nodes a — 4 muft be = ¢ (p—g) but if applied to ae as above denionftrated, the number of the vibration nodes will be p—+g; therefore e(p—g) = ~—4, which can no otherwife be true than when e¢ is = 1; that is, - : or muft be expreffed in its loweft terms. 5. As the members of two fractions not of the fame value may have the fame difference as + and 1, the fame number of vibration nodes may exift where the tones are different, and therefore each tone has not its own peculiar number of vibration nodes. 6. Vibration nodes are only pofhible where the tones have a certain ratio to the fundamental tone. It muft not, however, be expected, that the experiment can be made, for example, with a ftring 26 inches in length, in fuch a manner that you can divide it into 40 or 50 parts, and rub one of them with the bow; for in this cafe the vi- bration nodes, or points at reft, are at fo little diftance from each . Hints for the Formation of a Theory of the Earth. 35t each other that a piece of paper will cover more than one vibration riode, and will be thrown off by rubbing with the bow, though they ought to remain or the vibration will be too weak, and not be fufiicient to throw off the bits of paper which ought to fall. Til. Agenda, or a Colleétion of Obfervations and Refearches the Refults of which may ferve as the Foundation for a Theory of the Earth. By M. Dz Saussure. {Continued from page 265. ] CHAP. XIX. Refearches to be made in regard to Earthquakes. r xi Vur hiftorical part: the greatnefs, extent, and chro+ nology of their ravages in different countries. 2. Does it appear that fome countries are more expofed to them than others; are there fome abfolutely exempted ; and how far is this connected with the local fituation of the country ? 3. To obferve the extent, duration, and direG@tion of the vibrations experienced by the earth when it fhakes. 4. Are there any meteorological phenomena that an- Mounce or accompany earthquakes; fuch as extraordinary heat, calms, ftorms, movements of the barometer, electri- city, vapours difperfed throughout the atmofphere, palenefs or peculiar colour of the fun and ftars? §. Other phenomena; fuch as fubterranean noife, extrax ordinary movement of the fea, the water of {prings increafed or dried up, any particular {mell, fymptoms of terror among domeftic animals. 6. Are there any indications that fome earthquakes may have been the effects of electricity, and that fuch convulfions might be prevented by conductors? 7. Arc there not fome alfo which immediately depend on fubterrancam az Hints for the Formation of - fubterranean fires, and which are preceded by or accompa nied with volcanic eruptions ? 8. Are there any which exhibit indications of the effects of water converted into fteam ? g. To afcertain the fimultaneous or at ledft aftonifhing rapidity of the effects of earthquakes at very great diftances. 10. Are there any inftances that, during the moment of an earthquake, fome pretty confiderable traét of land, or 4 mountain, has been raifed to a great height above its former level, and has afterwards rernained in a ftate of elevation? 11. Are there dry fogs, fuch as that of 1783, which may be confidered as vapours, that have iffued from the earth by the action of fhocks or concuffions. CHAP. XX. Odjervations to be made on Mines of Metal, Coal, and Salt. 1. The hiftorical part: the epoch of the difcovery of 4 mine; of its being firlt worked; the expence and net pro- duce at different periods. If there ever was, or ftill is, a grant of it, and on what conditions. Bara) Li regard to the phyfical part, care muft be taken to examine whether the ore be in veins or ftrata; that is to fay, whether it interfects the {trata of the mountain, or be parallel to them. : 2. In mines which confit of veins, the dimenfions, thick- nefs, and length of the veins are to be examined ; their in- clination in regard to the horizon, and their direction in regard to the cardinal points. The miners call this direc- tion the hours. 3. The metal it contains; the mineralifing fubftance, and the kind of mineral which Hess refults. 4. The matrix, or non-metallic fofil, found mixed with the ore. 5. The nature of the foil at the bottom, or that part of the mountain on which the vein refts; nature of the cover- ing, or part of the mountain immiediately above it. 6. Nature - @ Theory of the Earth. 353 6. Nature of the covering of the veins, or thofe parts of the vein next to the fubftatice of the mountain. 7. Nature of the drufes, or cryftallifed geodes contained in the vein. . 7. A. The form, dimenfions, and nature of the mountain which contains the vein. 8. Situation of the vem in regard to the ftrata of the mountain ; under what angle it interfeGs them. g. Its fituation in regard to the exterior part of the moun- tain; whetlir it be parallel to the external inclination of the mountain, or whether that inclination be in a contrary direction. 10. The progrefs of the vein: whether it be fubjeé to change its direftion or fituation, and according to what laws ; if there are any indications that precede thefe changes 3 any corners, vacuities, or fiffures, which interrupt the courfe of the vein; and how it is found after having been loft: fituation and diftance of the place where it is richeft. 11. Lateral veins or ramifications of the principal vein; veins by which it is accompanied, or which run parallel to its ‘12. To verify Werner’s theory -in regard to veins, the fundamental principles of which are as follows :— A. That the fpaces occupied by veins have been origi- nally empty crevices or fiffures. B. That thefe fiffures have been afterwards filled from the a bottom upwards, at a time when the fea ftill covered the mountains; and by the precipitation or cryftallifation of the fubftances which were before diffolyed in the waters of the fea. C. That of two veins croffing each other, the moft mo- dern is that which interfects the other. D. That of two veins, one of which ftops and diverts the courfe of the other, the moft modern is the latter, “the furrounding fubftance, the falbande for inftance, are the moft ancient; thofe in the middle the moft modern; and the intermediate ones of a mean antiquity, Vou. lV. Aa F. Alfo | __ E. That, in the fame vein, the parts neareft to the fides of 354 Flints for the Formation of F. Alfo that, in the fame vein, the loweft parts are the moft ancient. G. That in fome veins there are found rolled pebbles ; in others the remains of organifed bodies, fhells, and wood ; and in others, of coal, ftones, and fea-falt. H. That one may affign the relative age of the formation of different minerals; for example, that tin mines may be faid to be of the moft ancient formation; then thofe of ura- nite, bifmuth, &c. The greater part of the fallawitig queftions will furnifh confirmations of this theory, or objections againft it, accord- ing to the folution given of them: 13. Is it true that there are mountains, or portions of mountains, fo pierced with cotemporary veins that they could not have fupported themfelves, had not the fubftance with which they are filled been created at the fame time as the mountain itfelf? I have ufed the expreffion cotempo- rary, becaufe, if we can fuppofe that the fiffures filled by thefe veins were formed in fucceflion, the objeétion which this fact would prefent to the theory of Werner would be by thefe means refolved. 13. A. I mutt here repeat the roth queftion of Chap. IT. How can it be conceived that all the metals and fubftances found in a vein fhould have been diffolved by the water of the fea *? 14. Is it true that there are in Derbyflire vertical veins of Jead interfeted feveral times by horizontal ftrata of amyg- daloides or load{tone ? _ 45. Are there found, in the neighbourhood of veins, ftrata of the fame mineral contained in thefe'veins, and which feem to have been depofited at the fame time when the de- pofits of the fea filled the fiffures occupied by thefe veins? . 16. Is it well.afcertained that there are certain metals and certain kinds of ore found only in certain kinds of moun- * Or in the waters of the great ocean, ‘lf are fuppofed to have ce- v ered the whole globe of the earth. C. - 4 tains? a Theory of the Earth.. 355 tains? And, if this circumftance be true, does it arife from the relative age of thefe minerals and mountains, or from the fubftance of the mountains favouring the precipitation of one kind of mineral more than that of another ? 17. Isit true, as M. de Trebra fays, that the richeft veins, and the richeft points of any vein, are found in the vertical line which correfponds with the lowe part of the refervoirs of the rain water, and never in the peaks and moft elevated ridges? And, if this be well afcertained, would it not prove that the veins had an origin pofterior to the grand revolu- tions which have given to the furface of our globe its prefent form, and that the metals have been depofited in them by the meteoric waters ? , 18. Is it true alfo that the richeft mines are found in mountains, the declivities of which are not fteep *? 1g. Are there inftances of veins, entirely exhaufted, being again filled up with ore? 20. Does the production of metals depend on the influ- ence of the fun and climate? Are they more frequently found near the eaftern or fouthern, than the weftern or northern faces of mountains ? 21. Can we generalife the obfervation made in Siberia, Tranfylvania, at Mount Rofe, and in other places, that in gold mines the veins are richer near the furface of moun- tains than at a greater depth. 21. A. Is it generally true, that the veiris are richer at ‘their points of interfection than in any other place? Ps , yb ne 22. Is the inclination of veins feen more frequently con- _ trary, than parallel to, the adjacent face of the mountain ? 23. Does it fometimes happen that the rock which forms the fides (nxeben-geflein) of the vein is as rich and even richer in metal than the vein itfelf; and would it thence * As the Saxon authors generally fay; becaufe the faé is true among them and in fone other countries, while the cafe is not fo elfewhere, and particularly in the Pyrenecs. C. Aaz follow, 356 Hints for the Formaiion of follow, that the metal arrives at the vein by Gliesting itfelf through thefe fides ? 24. Is it truc that, im mountains of granite, the grain of the granite is finer and the flone more tender in the neigh- bourhood of a vein? 25. Are there obferved in any mine proofs that fubterra~ nean fires have contributed to its formation by fubliming the metallic fubftances, or by melting them? In a word, are there feen there any traces of the action of fire ? 26. In the greater part of mines do-we not, on the con- trary, obferve proofs of the action of water in the fituation of minerals and of their matrices; in their dru/es (groups of cryf- tals), and in the ftate, form and nature of their cryfiallifation ? 27. Does-there prevail, at the bottonr of mines, a heat fu- perior to the mean temperature of the earth? And if fuch a heat exifts in any mine, may it not be explained by that produced by the lamps; by the miners themfelves; by fome accumulations of pyrites, or fome local refervoirs of water, without haying recourfe to a general caufe or cen tral fire? 28. Is it certain that, in general, veins decreafe in thick- nefs in proportion as they proceed to a greater depth, and terminate in fuch a manner that the fiffures which contain them are clofed at the bottom? Were this fac eftablifhed, — “would it deftroy the poffibility of fubhimations arifing frame Es | the interior parts of the earth *? j 29. In mines which proceed by firata, to obferve thei nature, extent, thicknefs, inclination, and depth; their-in- terruption by the veins that interfect them; their alternate fwellings and conftriétions, .as well as the augmentation and diminution of their richnefs, and ‘the figns which precede thefe changes. ‘ * 28. A. Do there exift veins of from ten to twenty fathoms and — more in thicknefs? or have not metalliferous banks or fiffures between x two different kinds of ftone been tak n for yeins? C,. , 30, Whe- a Theory of the Earth. 357 30. Whether it be rare to find, under the form of ftrata, other metallic mines than thofe of copper, iron, lead, cala- mine, and manganefe. 31. Whether the mines in ftrata are generally poor near the furface of the mountain, and become richer the deeper they proceed. 31. A. Whether mines, where the metal is found in Jumps or in a mafs ( flockwerke), ought to be clafled among thofe in veins or thofe in ftrata * ? 32. In coal mines to obferve the nature of the coal; more or lefs compact; more or lefs rich in bitumen; more or lefs mixed with argil or pyrites. 33. To examine, in the coal, the traces of their origin ; whether they have been formed of wood, turf, or marine plants t. , 34. To obferve whether there are found the remains of marine or terreftrial animals. 35. The progrefs of the ftrata: whether it be true that they often begin by defcending in order to become: hori- zontal, and afterwards to re-afcend; and that they are thickeft in the horizontal part, and give coal of a better quality {. _* 31. B. To obferve alfo a third pofition of the ore, or ore found in the tranfitions (fein-/ebeidung); that is to fay, between two kinds of fione of a very different nature; as between argillaceous fchift and calcareous frone, between the fame fchift and compound rocks, &c. Not to con- found this pofition of ore with real veins, nor with metalliferous banks, ore in ftrata, and the flockwerke. C. $ 33- A. To diftinguih carefully real coal from jet or foffil coal (the braun-koble of the Germans), and from coal earth, as well as from that fubftance known by the Germans under the name of dlend-koble. C. 33- B. To examine whether there is not found fometimes in calcareous foil, fat, gelatinous coal; or whether there is never found but dry, friable coal, C. I ; t 35. A. To afcertain whether there exifts foffil coal in veins, as is faid to ve the cafe at Wehrau in Upper Lufatia. Cy Aa 3 36. Whes 2 358 Hints for the Formation of a Theory of the Earth, 36. Whether there are feveral ftrata, one above the other, with banks or other foflils interpofed. The quality and re- lation of thefe flrata. 37. The nature and thicknefs of the ftrata of the earth or ftones under which the coal mine is found; the im- preffions and other veltiges of organifed bodies found in thefe ftrata. 37. A. How can thofe who afcribe the origin of coal to forefts buried in the earth, explain the very thin ftrata of that foffil contained between banks of calcareous ftones, and which are repeated at different heights in the fame moun- tain? Does not this obfervation fhew that there are coal which have originated alfo from fuci, alow, and other ma- rine plants ? 37. B. Ought we to fuppofe that all coals have been in a ftate of folution? What is the agent which diflolved them, and which may be called the mineralifer? 38. Though mines of rock falt are commonly found in ftrata, yet M. Fichtel affirms, that there are found in Tran- fylvania enormous mafles of pure falt, compact, and without any appearance of foreign bodies. Thefe he confiders as of very ancient formation, and diftinguifhes them from thofe which are in ftrata between beds of argil and free-fione mixed with fhells. Thefe important facts deferve to be thoroughly examined, 39. To afcertain the truth of an affertion made by the fame geologift, that thefe maffes of falt are furrounded by ancient volcanoes; and to determine whether we ought to believe with him, that this falt has been cryftallifed by the heat of thofe voleanoes which evaporated the water that held them in folution. 40. To examine, in the laft place, whether any of thefe maffes of falt appear to have been raifed up by {ubterranean fires to a height greater than that at which they were at the time of their formation, 41. To Account of a large Tree in India. 359 41. To examine the reafon of the fingular connection obferved between mines of falt or falt fprings and mountains of gypfum *. [To be continued.] IV. Account of a large Tree in India. By Colonel IRONSIDET. By the fide of the Ganges, about three miles above the fortrefs of Allahabad, near the fmall pagoda of a goffeir (fakir), 1 faw, on the a1ft of November 1777, four trees called kulberich; the trunk of one of which appeared of fo uncommon a fize, that I fent for a ftring'to meafure its di- menfions, and found the circumference of it_to be thirty feet ten inches. Its height is that of a pretty large beech, the rind or bark even, annulated and pulpy; and all the limbs fmooth and very large, but rather feant of foliage ;. thofe very fmall branches which bore Jeaves being in cluf- ters, fo that the tree, at fome diftance, feemed not unlike a fiem of the thick fpecies of coralline. The leaves are the fize of oak leaves, but not finuated, and of a light though not bright green; the fruit is of the fame colour, in fhape almoft conical like a pine, nine inches long, eleven inches and a half round the moft {welling part, and with a foft velyet rind. Not being in bloffom at that feafon, I had no opportunity to obferve the flower. The fakir told me that there were only thofe four within 700 miles of the place; the feeds of them, which are fhaped like a kidney bean, and as large as a caravan/a, having been fent for by one of the * And particularly of gypfum coloured by a red argil. To examine alfo why afphaltes is commonly found in the neighbourhood of falt-pits. 42. To obferve the different efflorefcence of the different falts formed on the rocks and the furface of rhe earth, in order to determine their pa ture. 43- To note alfo the nature, the abundance, and what may be difcoe aered in regard to the origin of mineral waters: to determine the tempe- ature of them. C. + From the Oriental Colleions, Vol. I. Aag emperors, 360 ' Aécount of @ Banian Tree emperors, and fown thete. The groves and fafhion of the ground, as well as the fruit-trees, and a large ftone wall about them, indicate the place to have been once a garden, and it is called to this time Bejum-ke Baug, or the Queen’s Garden, On my arrival at Patna, on the 2d of January 1778, I luckily met with a gentleman named Kerr, celebrated for his fkill in botanical refearches, who told me that the above- mentioned tree was: of the fpecies claffed in the Linnean fyftem under the name of Adanjonia, a defcription of which is to be found in the fixth edition of his Genera Plantarum, printed at Stockholm 1764, p. 352. V. Account of a Banian Tree in the Province of Babar. By Colonel IRONSIDE *, Near Manjee, a fmall town at the confluence of the Devah (or Gogra) and the Ganges, about twenty miles weit of the city of Patna, there is a remarkably large tree, called a bur or banian tree, which has the quality of extending its branches, in a horizontal dire€tion, to a confiderable diftance from its fiem; and of then dropping leaflefs fibres, or fcions, to the ground, which there catch hold of the earth, take root, embody, grow thick, and ferve either to fupport the protraéted branches, or, by a farther vegetation, to compofe a fecond trunk. From thefe branches other arms again {pring out, fall down, enter the ground, prow up again, and conftitute a third ftem, and fo on. From the oppofite pretty high bank of the Ganges, and at the diftance of near eight miles, we perceived this tree of a pyramidical fhape, with an eéaly fpreading flope from its fummit to the extremity of its lower branches, and miftook it at firft for a fmall hill: we had no quadrant to meafure its height; but the middle or principal ftem is confiderably higher, I think, than the higheft elm, or other tree, I ever faw in England. The fol- * From the O:veutal Colletions, Vol. I- Jowing in the Province of Bahar. 36% lowing compiife fome other of its dimenfions, which were taken with a cord of a given length ae ' Yards. Feet. Diameter of the branches from north to fouth 121, or 363 Diameter of ditto from eaft to weft - 125, 0% 375 Circumference of the fhadow of the extreme branches, taken at the meridian - 372, oF 1116 Circumference of the feveral bodies or {tems, taken by carrying the cord round the outer- moft trunks - - - 307, OF 92% The feyeral trunks may amount to fifty or fixty, N.B. The dropping fibres {hoot down from the knots of joints of the boughs. This tree, as well as the peepe/, and many other large trees in India, is a creeper. It is often feen to fpring round other trees, particularly round every fpecies of the palm. The date, or palmyra, growing through the centre of a banian tree, looks extremely grand; and yet none of the European landfcape painters, who have delineated views of this coun- try, have introduced this characteriftic objet into theit pieces. I have frequently obferved it alfo fhooting from old walls, and running along them. In the infide of a large brick-wall it lined the whole circumference of the internal {pace of it, and thus aGtually became a tree turned infide out, Under the tree fat a fakir, or devotee. He had been there twenty-five years; but he did not continue under the tree throughout the year, his vow obliging him to hie, during the four coldeft months, up to his neck in the Ganges; and to fit, during the four hotteft months, clofe to a large fire, VI. On t, 362, J VI. On the different Kinds of Cadmia, and particularly thofe of Zinc and Cobalt. By 1.1. BinpHxEIM of Mofcow, [Concluded from Page 255.] Of CoBALT., I; is fearcely a century and a half fince people knew how to make ufe of cobalt ore. Brand, counfellor of the mines in Sweden, firft proved that cobalt was a femi-metal, and that it poffeffed peculiar properties different from thofe of other metals. He defended his opinion againft various objections that were made to it; but it is ftill believed by fome, that it is a mixture of copper, iron, and arfenic: and this feems the more probable, as a fixed blue colour, fit for being employed in the arts and manufactures, is prepared with adyantage at Vienna from iron and arfenic. | This, however, does not place the circumftance beyond all doubt, for it {till remains to be examined whether the arfenic and iron employed for that purpofe be free from cobalt; and, until that be afcertained, the fact muft be involved in un- certainty ; for both, or at leaft one of them, may be mixed with cobalt. Lehmann was of opinion, that the colouring matter of cobalt confifted of a fine alcaline earth combined with fome particles of copper and iron; and he made experiments on this fubje&t, by which he obtained blue glafs. But from the defcription he gives of his experiments it does not appear fufhciently proved that ingredients free from cobalt were ufed for the mixture. The reafon why fome may have been inclined not to aferibe the principle which colours fmalt to a metallic fub- ftance may have been, that they employed for their experi- ments a cobalt ore free from arfenic, and did not apply a fufficiently itrong heat, without which the regulus of cobalt is difficult to be fufed, and not fo eafily feparated: the prin- ciple which gives the blue colour to glafs is, however, to be afcribed On the different Kinds of Cadinia, &c. 353 aicribed certainly to the metal of cobalt, as has been placed beyond all doubt, and clearly proved by the experiments of M. Meyer, to be found in Sellers’ Colle@ions. Some, on the other hand, have endeavoured to banith co- balt from the number of metals; but no one will certainly any longer doubt of its being a peculiar metal, fince it is well eftablifhed, that fimple fub{tances are properly confidered to be fpecifically different when they exhibit various properties which other bodies do not poffefs, and that every fubftance is confidered as fimple when it cannot be feparated into dif- ferent principles, and be again formed from them. Now this is confirmed in regard to cobalt; and it is found that it not only poffeffes properties different from thofe of all other me- tals, but is itfelf a metal of a totally peculiar kind. Even though there be an analogy between iron, nickel, arfenic, and cobalt; and though, according to the fuppofed hypo- thefis, the regulus of cobalt is only a variety of iron, and that it is difficult, if not impoflible, to feparate it from cobalt; yet the latter ftill remains a metal of a peculiar kind. The firft and principal refearches for difeovering cobalt mines were made in the Saxon mountains, and thefe pro- cured to that country an opportunity of carrying on a con- fiderable trade with this production. Good cobalt ore, fit for colouring, is found at prefent, though not in fuch abun- dance, in Heffe, Wurtemberg, the Harz, Bohemia, Pruffia, Silefia, and Sweden. As far as I know, pure native cobalt has never yet been found; what is commonly pretended to be fuch, is mine- falifed by arfenic. It is found in an oxygenated flate, and always combined .with iron, and alfo mineralifed with car- bonic acid; in vitrious cobalt ore, by the fulphuric and the arfenical acids; and to this belongs the fo called flowers of cobalt, found in tender reddith cryftals: it is alfo found qmineralifed by arfenic, with a little iron, in dull grey cobalt ere; by fulphur and arfenic, with iron, in white arfenical cobalt 364 On the different fers of Cadmia, and cobalt ore; and by a little fulphur, with abundance of iron without any arfenic, in fulphurated cobalt ore. When fuch ore is treated in the fire, the arfenic evaporates, and the metallic and earthy particles remain behind, which, in order to be prepared for commerce, muft be mixed with pounded quartz or fand, afterwards moiftened, and then packed up in cafks under the name of /aflor or zaffera. If very fufible glafs be melted with a little cobalt ore, and if ihe mafs be finely pulverifed, it produces fmalt, which, by wafhing, may be fitted for an article of commerce of diffe- rent qualities and forted. This fmalt, however, contains in general an impure regulus of cobalt, which often confifts of a mixture of cobalt, iron, arfenic, and nickel, and is called cobalt fpeife. If you with to obtain a pure regulus of cobalt, you muft choofe for that purpofe a cobalt ore as free as pof- fible from foreign metallic fubftances, You muft then roaft it carefully according to the proportions of fulphur and arfe- nic which you find in it, and reduce it by adding carbona- ceous matter to take up the oxygen, and a good alcaline flux at a {trong fufing heat. If the cobalt ore employed contains bifmuth, and is free from nickel, the regulus of bifmuth will be found at the bottom of the reduced cobalt in a feparated ftate. This regulus is not pure, and fufficiently free from iron; but it may be brought to purity, though with trouble anda confiderable lofs of the regulus of cobalt. To effeé this, it muft be calcined with borax, on a teft, jn the fame. manner as copper, until] it is no longer attracted by the mag- net. Some, however, are of opinion, that iron is not the only metal attracted by the loadftone, and that it exercifes an attractive power over the fineft blue colouring regulus of cobalt: but there are well-grounded objeétions againft this idea, for that effe¢t takes place only when the latter is not fuffciently freed from iron; and according to the experi- ments of Bergmann, a compofition of one part of iron and three parts of cobalt is attracted by the magnet; but if the . proportion, particularly thofe of Zinc and Cobalt. 953 proportion of the iron be confiderably lefs, that effect is not produced. The fpecific, gravity of a reoulus of cobalt, purified as much as poflible by the above method, is 7°700*; its colour is a pale greyifh blue, but it becomes fomewhat darker when expofed to the atmofphere: it is finely granulated on the fracture, and requires a ftrong degree of heat to be fufed, efpecially when no arfenic is prefent ; and therefore it hap- pens that it is fo difficult to extra&t the regulus by fufion from cobalt ore which contains no arfenic. It is not, how- ever, volatile, like the greater part of the femi-metals; and does not inflame and evaporate, but when calcined becomes a blackifh oxyde. When cobalt is pure, it diffolves in acids with a red colour 3 when it does not diffolve, it is a fign that it is prevented by fome foreign mixture: if the {olution be green, it commonly implies the prefence of nickel. With the vitriolic acid cobalt affords brownith red cryf- tals; the nitrous acid diffolves it alfo of a red colour: by the muriatic acid regulus of cobalt is diffolyed with difficulty, but its calx eafily diffolves. This folution is red when cold, but when expofed to a heat of 80 degrees becomes green ; it fhoots into red cryftals inclining to blue : if thefe eryftals ave diffolved in water, and a little of the muriatic acid be added, it produces that kind of fympathetic ink which becomes green when heated, and invifible when cold. The acetous acid diffolves the calx of cobalt alfo of a red colour. If fuch folu- tions are precipitated by volatile lixivious falts (ammonia), and the quantity neceflary for faturation be added, it is res diffolved of a dark red colour. In the wet way the oxalic acid, and in the dry way iren, have the greateft affinity with cobalt. It combines with all metals except filver, lead, and bifmuth. Regulus of cobalt unites only weakly with fulphur, but is fully diffolved by fulphat of pot-afh. * Bergmann Sciagr., but in his Differtation on Nickel he makes it $*«¢, 6 VIE. Sa- [ 365 J VII. Singular Cure of a_young Woman, effeéted by expelling from the Stomach, &c. the Larve of certain Infeéts. By M. ODHELIUs*. ee account of this fingular cafe was tranfmitted to M. Odhelius, together with fome of the larvae, by M. Flank, furgeon of Carlftadt, who, during the courfe of forty years praétice, never faw any of the like kind difcharged from the human body. The patient, who was feventeen years of age, and who for three years had been quite regular, became in- difpofed in the year 1786, and complained of a violent pain and griping in her ftomach, with a head-ache and confufion - in the morning, a burning in the throat, and great laffitude- Thefe fymptoms were leffened after repeated eructation ; but the diforder ftill increafed. Mineral water with jalep pow- der was prefcribed, and the larve began gradually to be dif- charged; but as the patient did not find much relief, and as fhe naufeated jalep powder, aloe pills, with jalep refin, and mercurius dulcis, were adminiftered in its ftead, and about a quart of mineral water each time; by which means thefe troublefome guefis were gradually fo completely expelled, that the patient, in the courfe of a few weeks, was perfectly éured. The larve were tranfmitted to the Cabinet of Cu- riofities belonging to the Academy of Sciences. Profeffor Wilke found, on exammmg them, that they were of the fpecies defcribed by Reaumur under the name of Vers ¢ queue de ratt , and which belong to a kind of two-winged fiy, called the Pendulous Fly, Mu/ca pendula L.; becaufe the larve are fufpended, as it were, by a long thread, which is their organ of refpiration. Thele larvae, which the Pro- felfor examined, were of a yellowifh-brown colour, from four to fix lines in length, with a tail of about the fame extent ; a cylindric body, from half a line to a line in thicknefs, cut * From New Tranfudtions of the Academy of Sciences at Stockholm, Vol. x. t By pour l'Hift. des Infectes, T.1V. Mem. 11. pe 443° ' : acrofs — On the Signs exbibiied by Animals, &c. 367 acrofs fomewhat obliquely before, and conical towards the tail. As the patient, before fhe fell ill, had ufed a great deal of milk and cheefe, M. Wilke was of opinion, that fome of the eggs of thefe flies had been conveyed into her ftomach in the rind of the cheefe. VIII. On the Signs exhibited by Animals which indicate Changes of the Weather, with Remarks on other Pro- gnofications. ByM.Toatpo*. Tue fluids and folids of organifed beings, and their ani- mal machines, are conftructed in fuch a manner that a cer- tain degree of motion puts them in a good ftate, while an augmentation or diminution of it deranges and deftroys that ftate. The fluids, which by their nature are eafily moved, as well as the fibres, which are highly fufceptible of irrita- tion, are readily affected by changes of the furrounding at- mofphere, and fuffer from their impreflions, whether the air varies in its weight or qualities, or is changed in regard to its elafticity. We find, among thofe who are found and in perfect health, vivacity, good fpirits, and great agility, | when the air is pure and claftic; on the other hand, when the air becomes light and damp, and tis deprived of its elaf- ticity, it throws the body into a ftate of languor and debi- lity. Valetudinarians, whofe conftitutions are delicate, or who are advanced in life, are much fooner fenfible of the impreffions occafioned by changes of the weather than thofe who are ftrong and robuft. In general the fenfes of men, who in their way of life deviate from the fimplicity of na- ture, are coarfe, dull, and void of energy. Thofe alfo who are diftraéted by a thoufand other objects, fcarcely feel the impreffions of the air; and if they {peak of them to fill up a vacuum in their miferable and frivolous conyerfation, they “do it without thinking of their caufes or effects, and withouz bs Pron his Metecrological Efays. ever 368 On the Signs exhibited by Animals ever paying attention to them. But animals which refaire their natural inftinét, which have their organs better confti- iuted and their fenfes in a more perfect ftate, and which befides are not changed by vicious and depraved habits, perceive fooner, and are more fufceptible of the impreffions produced in them by variations of the atmofphere, and fooner exhibit fiens of them. Until the new difcovery:of animal pleceieity little at- tention was paid to thefe figns, which were confequently afcribed to a certain natural prefcience. But as the eleétric matter iffuing from the earth diffufes itfelf through the at- mofphere, it mutt penetrate and agitate the frail machines in queftion ; and as it carries with it vapours and exhalations of various kinds, thefe muft produce, on machines fo deli- cate, different fenfations, which make them move in a dif- ferent manner; and, according as the received impreffion is agreeable or troublefome, they cbibies igns of joy or fadnefs; fend forth cries, or are lent; move, or remain at reft; as is obferved in all kinds of animals, without excepting man, when the weather is about to change. In the laft place, internal and animal electricity, which in all probability is the agent of life and the grand fource of organic motion, muft be as much fubjeét to modifications as the external electricity, from which it acquires new force and aétivity by the vapours and humidity of the atmofphere, which abforbing the electric matter in abundance, or ferving it as a conductor, draws it off from the animal machine. Hence arifes that languor and debility which are experi- enced during wet weather and when the fouth wirids pre- vail; and for the fame reafon the moifture which has pene- trated the organs, at leaft thofe that are weak or have fuf- fered any hurt or injury, or,been expofed to fome new agi- tation, produces uneafinefs. and occafions pain. It is diffi- cult to explain clearly and with precifion how all this takes place; that is, how the electricity is excited, and by what mechanifm exhalations and vapours affe€t animals, and pro- duce Pa: > “a which indicate Changes of the Weather. 369 tlice changes in their bodies, fince we are not acquainted with the curious organifation of the moft delicate parts of thefe machines; but we can obferve and perceive the pro- grefs and general confequences of thefe phenomena, as well as of thofe by which they are produced. The following are the common and familiar fiens exhibited-by animals, which indicate changes of the weather, and which are not taken fo much from the agricultural poet, who firft collected theni, as from conimon obfervation : 1. When the bats reniain longer than ufual abroad from their holes, fly about in greater numbers and to a greater diftance than common, it announces that the following day will be warm and ferene; but if they enter the houfes, and fend forth loud and repeated cries, it indicates bad weather. 2. If the owl is heard to fcream duting bad weather, it annourices that it will become fine. 3. The ctoaking of crows in the morniti¢ indicates fine weather. 4. When the raven croaks three or four times, extending his wings and fhaking the leaves, it is a fign of ferene wea- ther. 5. It is an indication of rain atid ftofmy weather when ducks and geefe fly backwards and forwards; when they plunge frequently into the water, or begin to fend forth cries and to fly about. 6. If the bees. do not remove to a eteat diflance from their hives, it announces rain; if they return to their hives before ‘the ufual time, it may be concluded that it will foon fall. 4. If pigeons return flowly to the pigeon-houfe, it indi- cates that the fucceeding days will be rainy. 8. It is a fign of rain or wind when the {parrows chirp a great deal, and make a noife to each other to affemble. g. When fowls and chickens roll in the fand more than ufual, it announces rain: the cafe is the fame when the cooka, crow in the evening, or af uncommon hours. Vou. IV. Bb 10. Pea- 370 On the Signs exhibited by Animals 10. Peacocks, which cry during the night, have a pre- fenfation of rain. t1. It is believed to be a fign of bad pester when the _ fwallows fly in fuch a manner as to brufh the furface of the water, and to touch it frequently with their wings and breaft. 12, The weather is about to become cloudy, and to change for the worfe, when the flies fling, and become more trou- blefome than ufual. , a 3. When the enats collect themfelves before the fetting of the fun, and form a fort of vortex in the fhape of a co- jumn, it announces fine weather. 14. When fea-fowl and other aquatic birds retire to the fea-fhore or marfhes, it indicates a change of weather and a fadden ftorm. 15« If the cranes fly exceedingly high, in filence, and ranged in order, it is a fign of approaching fine weather ; but if they fly in diforder, or immediately return with cries, it announces wind, 16. When the dolphins fport and make frequent leaps, the fea being tranquil and calm, it denotes that the wind will blow from that quarter from which they proceed. , 17. If the frogs croak more than uftal; if the toads iffue from their holes in the evening in great numbers; if the earth-worms come forth from the earth, and fcorpions ap- pear on the walls; if the ants remove their eggs from their {mall hills; if the moles throw up the earth more than ufual if the afles frequently fhake and agitate their ears ; if the hogs fhake and fpoil the flalks of corn; if the bats fend forth cries, and fly into the houfes; if the dogs roll on the _ ground, and feratch up the earth with their fore-feet; if the - gows look towards the heavens, and turn up their noftrils as “if catching fome fmell ; if the oxen lick their fore-feet, and if oxen and dogs lie on their right fide; all thefe are figns. Which announce rain. 18. The cafe is the fame when animals crowd together. oe 4 1g. When which indicate Changes of the Weather. 37% tg. When goats and fheep are more obftinate and more defirous to crop their paftures, and feem to quit them with, reluctance; and when the birds return flowly to their nefts, rain may foon be expected. Other Signs which announce Changes of the Weather. 1. If the flame of a lamp crackles or flares, it indicates rainy weather. 2. The cafe is the fame when the foot detaches itfelf from the chimney and falls down. : 3. It is a fien of rain, alfo, when the foot collected around pots or kettles takes fire in the form of fmafll points like. grains of millet; becaufe this phenomenon denotes that the air is cold and moitft. 4. If the coals feem hotter than ufual, or if the flame is more agitated, though the weather be calm at the time, it indicates wind. 5. When the flame burns fteady, and proceeds ftraight upwards, it is a fign of fine weather. 6. If the found of bells is heard at a great diftance, it is a fign of wind, or of a change of weather. 7. The hollow found of forefts; the murmuring noife of the waves of the fea; their foaming, and green and black colour, announce a {term. ~ 8. Good or bad fmells, feeming as if it were condenfed, are a fign of a change of weather ; either becaufe exhalations arife and are difperfed in more abundance, which is a fign of an increafe of electricity ; or becaufe the air does not dif- pell or raife thefe exhalations, which indicates that the con- ftitution of the atmofphere is motionlefs, light, and void of elafticity. \ g. When the fpiders webs and the leaves of the trees are agitated without any fenfible wind, it is a fign of wind, and perhaps of rain; becaufe it denotes that ftrong and_pene- trating exhalations arife from the earth. 10. Thefe figns are lefs equivocal when the dry leaves and chaff are agitated in a vortex, and raifed into the air, Bb 2 1r,A 372 On the Signs exhibited by Animals 1x. A frequent change of wind, accompanied with an agi- ¥ation of the clouds, denotes a fudden ftorm. 12. A want or too great a quantity of dew being a mark: ‘of a ftrong evaporation, announces rain: the cafe is the fame with thick, white hoar-froft, which is only dew con- gealed, | 13. If falt, marble, and glafs become moift fome days before rain; if articles of wood, doors, and chefts of drawers fwell; if the corns on the feet and the {cars of old wounds become painful; all thefe figns indicate that aqueous ya- pours are exhaled from the earth, and are no doubt direéted by the electric matter, which diffufes itfelf then in greater abundance and penetrates every body. Hence it happens that ftones become moift, that wood fwells, and falt be- comes deliquefcent by the moifture. When the ftones after being moift become dry, it is a fign of fine weather, 14. On the other hand, when the weather inclines to rain, the water is feen to diminifh in vafes and fountains, becaufe the humidity is then carried away by the evaporation of the electric matter, 15. It is certainly a furprifing phenomenon to fee the earth,, after very long and very abundant rains, to be fome- times almoft dry, the roads quite free from dirt, and the hands to become arid and parched. This is a fign that the rain has not altogether ccafed, and denotes a continual efflux of eleétric matter, which being renewed carries with it, 1m ~ the form of vapours, all the moifiure that falls onthe earth, 16. There is fometimes, however, a great deal of dirt even after a very moderate rain, which in that cafe is a fign of a fine weather, becaufe it indicates that evaporation has ceafed, — Dry ftones and moift earth announce fine weather; dry earth and moift ftones announce rain. - 17. The winds which begin to blow in the day-time, are much ftronger, and endure Jonger, than thofe which begin to blow only in the night. sg 18. Weather, whether good or bad, which takes place in the which indicate Changes of the Weather. 373 the night-time, is not, in general, of long duration; and, for the moft part, wind is more uncommon in the night than in the day-time. Fine weather in the night, with {cat- tered clouds, does not iaft. 19. A Venetian proverb fays, that a fudden ftorm from the north does not laft three days. 20. The hoar-froft, which is firft occafioned by the eaft wind, indicates that the cold will continue a long time, as was the cafe in 1770. 21. If it thunders in the month of December, moderate and fine weather may be expected. 22. If it thunders at intervals in the fpring time, before the trees have acquired leaves, cold weather, is {till to be ex- pected, 23. If the wind does not change, the weather will remain the fame. Such almoft are the figns of the variations of the atmo- fphere; but I will not be anfwerable for the certainty of them all. Plutarch, in his Problems, where it is afked why a horfe who has efcaped from a wolf becomes fleeter, re- plies, that becaufe, by a fingle action, but executed with great force and vigour, he has aequired a difpofition to rum- ning and a habit of fpeed; or perhaps, becaufe he is natu- rally {wift and agile: but he adds, perhaps neither of thefe is true. “This obfervation, I am. afraid, will apply to fome of the vulgar prognoftics of the prefent day. For example, we are told, that it is a fign of fertility im any year when a fly is engendered in an acorn of that year; and that it is the fign of a peftilential year, if there iffues from it a {pider. Should the reafon be afked, it might be replied, that neither ‘of thefe is true. I might venture to fay as much of thofe ‘popular tales in regard to certain critical days of the month; yet we muft ftill have fome refpeét for popular proverbs, which are often founded on obfervation and reafon. Thus it jsfaid, that if it rains on the 3d of May, the day of the Holy Crofs; or on the 93d of April, St, George’s day; or the Bb3 15th 374 On the Signs exhibited by Animals, &e, 15th of June, St. Vitus’s day, &c.; in the firft cafe the nuts will be fpoiled; in the fecond, the figs; and in the third, the grapes. All this may be true to a certain degree, that is to fay, when it rains for a certain number of days about thefe periods; becaufe, if rain falls at the time when fruit- trees are in bloffom, it carries off the fecundating farina, and ~ by thefe means renders them barren. In regard to the general qualities of the feafons, and their influence, attention may be paid to the following figns:—= 7 If the earth and air abound with infeéts, worms, frogs, lo- 7 cufts, &c.; if the walnut-tree has more leaves than fruit; if there are large quantities of beans, fruit, and fifth; if ‘the fpring and fummer are too damp; if hoar-froft, fogs, and dew come on at times when they are not generally feen, the year will be barren: the oppofite figns announce fer- — tility and abundance. Animals feem alfo to forefee and pro+ — 4 gnofticate fertility or barrennefs: it is faid that when the ] birds flock together, quit the woods and iflands, and retire | to the fields, villages and towns, it is a fign that the year will be barren, a A great quantity of fnow in winter promifes a fertile year, — but abundant rains give reafon to apprehend that it will be — barren. A winter, during which a great deal of fnow and | rain falls, announces a very warm fummer. It is generally — | believed that thunder and ftorms in winter prognofticate | ebundance, becaufe they fertilife the earth. When the fpring ~ is raimy, it produces an abundant crop of hay and of ufelefs a herbs, but at the fame time a fearcity and dearth of grain, If it is warm, there will be plenty of fruit, but they willbe almoft all fpoilt. If it is cold and dry, there will be few fruit — or grapes, and filk-worms will not thrive. If it is only dry, there will be few fruit, but they will be good. In the © Jaft place, if it is cold, the fruit will be late in ioe to mas turity, de If the {pring and fummer are both damp, or even’ ‘hotly i dry, a fcarcity and dearth of provifions is to be apprehended, On the Effects of Oil in the Bite of Serpents. 395 if the fummer is dry, there will be little corn: difeafes will alfo prevail ; but they will be more numerous if it is warm. If it is moderately cold, the corn will be late; but there will be a great deal of it; and the feafon will occafion few dif- eales, A fine autumn announces a winter during which winds will prevail: if it is damp and rainy, it fpoils the grapes, in- jures the fown fields, and threatens a fcarcity. If it be too cold, or too warm, it produces many maladies. A long feve- rity of the feafons, either by winds, drought, dampnefs, heat _ or cold, becomes exceedingly deftructive to plants and ani- mals. In general, there is a compenfation for rain or drought between one feafon and another. A damp fpring or fummer is commonly followed by a fine autumn. If the winter is rainy, the fpring will be dry; and if the former is dry, the latter will be damp. When the autumn is fine, the {pring will be rainy. That this alternation is in general verified may be feen in a Journal carried on for forty years, and for- merly edited by M. de Poleni. IX’. On the Effects of Oil in Cafes of the Bite of Serpents; republifoed from the Charleftown (South-Carolina) City Gazette™, Mefirs. FRENEAU and PAINE, READ with pleafure, in your paper of the 21ft of No- vember, “ fome fhort directions for the cure of the plague,” compofed from a {mal] pamphlet lately publifhed by Count Berchtold at Vienna, by the ule of /weet olive oil. To take off the fharp edge of misfortune, or to meliorate the condition of man, is a godlike employment. Count Berchtold will be defervedly claffed by the philanthropift among the benefactors to mankind. In great cities, particularly in London, a number of per- * From the American Medical Repofitory, Bh 4 fons 376 On the Effetts of Oil fons procure their livelihood by catching vipers. They are emploved by chemifts, apothecaries, &c. T remember, fome years before leaving England, to have read, in the Philofophical Tranfactions of the Royal Society in London, a curious cireumftance relative to one of thefe viper-catchers. A member of the fociety had received, cafually, informa- tion that a man engaged in this bufinefs was frequently bitten, and that he cured himfelf by /weet'olive oil. After confiderable inquiry, the viper-catcher was found, and the queitions afked, whether he did cure himfelf by the oil? and whether he was willing to gratify a number of gentlemen of the fact? The man anfwered affirmatively to both queftions. Accordingly, a moft numerous meeting of the Royal Society was convened, compofed of a contiderable number of the nobility, &c. The viper-catcher attended, accompanied by his wife, with a large viper; and ‘laying his arm naked to the fhoulder, fuffered the irritated reptile to firike, which it did very forcibly. His wife permitted the poifon to operate till her hufband’s head, face, and tongue were greatly {welled, his arm and face alfo very black, and his fenfes much af. fected, when he applied the oil, by pouring a {mall quantity down his throat, and bathing the part bitten. The man gra- dually and foon recovered. This circumftance being ftrongly impreffed upon my mind, and knowing that the poifon of an Englith viper is confidered in that country the moft fubtile in nature, deter- mined me to try its antidotal power in the bite of the rattle- fnake, the firft opportunity which fhould offer, on my retire- ment from Charleftown to the back country, now called Pendleton County. I was alfo particularly impelled to make the trial, from a confideration of the newnefs and wildnefs of the country, and the number of my family, befide which there were hardly a dozen more 1n the country. This was jn the year 1786. In about a month after my arrival, a perfon in full fpeed 6 came in the Cafe of the Bite of Serpents. 377 came to my camp, and moft urgently begged to know if I could affift a man who had juft been bitten by a very large rattle-fnake. ‘Although I lamented the misfortune, I re- joiced at the opportunity it offered to afcertain fully the pro- perty of olive oil as an antidote to this deadly poifon; ac- cordingly I put a phial of oil in my pocket, and mounted the meflenger’s horfe. When I arrived at the unfortunate man’s cabin, he ftruck me as the moft frightful object I had ever beheld, His head and face were prodigioufly {welled, the latter black ; his tongue. proportionably enlarged, and out of his mouth ; his eyes as if fhooting from their fockets; his fenfes gone, and every appearance of immediate fuffocation. He had been ftruck on the fide of the foot, about the middle, in the hollow. Immediately, but with great difficulty, I got down two table-fpoons full of oil. Its effect was almoft inftantaneous, and aftonifhingly powerful in counteracting the poifon, as appeared by the ftrong though quick convulfions that fol- lowed. In about thirty minutes it operated ftrongly, both emetically and cathartically ; after which the {welling of the head, face, &c. gradually abated, and the tongue began to afflume its place. In about two hours he was fo far reco- vered as to be able to articulate, and from that time reco- vered faft. The oil, inwardly taken, and applied to the foot and leg, both exceedingly fwelled, did not exceed feven or eight {poons full. The number of cafes, of a like nature, in the courfe of twelve years, has been confiderable; in all which, olive oil has proved itfelf to be peculiarly adapted and fully adequate to the wortt of cafes, if timely applied. It is a remedy which every perfon may command (may have at hand when others cannot be procuyed), and ought not to be without; indeed, many cautious people here carry a fmall phial of oil con- fiantly about them. It has alfo been ufed with equal fuc- ¢els when horfes, cattle, and dogs have heen bitten, Thus 1s 378 . . Thoughts 6n Deafnefs. is the mind relieved from terror in thofe whofe occupation fubjeéts them to the bite of the fnakes, from a well-grounded confidence in the certain efficacy of the oil, and to which every one may have inftant recurrence. The cafe, Iam informed, has occurred, where the oil fuc- ceeded when given to a woman bitten by a mad dog, under ftrong fymptoms of hydrophobia; but at prefent I am not fufficiently in poffeffion of particulars to warrant its com- munication. I can hardly excufe myfelf of criminal neglect in having fe long omitted to make thus public this fovereign antidote to the worft of animal poifons. The knowledge of the efficacy of the olive oil 1s abundantly diffufed in this county, and partially in fome of the adjoining counties. The infertion of the foregoing particulars in your City and Carolina Gazettes, muft make its invaluable properties gene- rally known. With great efteem, Iam, &c. Pendleton County, July 4,1798. J. MILLER. x. Thoughts on Deafne/s; with a new Mode of making Deaf People hear. Written 15th December 1798, by D. Wurter, M.D. His Majefly’s Ship Ailas, SIR, ra Torbay, gth Auguft 1799, Dahetive feen in a late newfpaper an account, copied from your Magazine, of a new mode of conveying founds for the bencfit of deaf perfons, propofed by Profeflor Blu- menbach, I have extraéted from my Medical Diary what t wrote fome months ago on this fubject. As my ideas were ‘Potdhea without any knowledge of the German difeovery, you will oblige me much by giving them a Piney | in abr very valuable Mifeellany,. I am, Sir, your humble retlsath . Phe Editor of the t D. WHYTE, FP bilofophical Magazine, § ; IT 4 Thoughts on Deafnefs. . 379 IT has been a general remark, that deaf people fpeak in a wery low tone of voice, while they themfelves conceive that they fpeak very loud. It is fuppofed that the deaf perfon, not being fo eafily affected by found, anfwers in what he be- lieves to be the proper and correfponding pitch. I came down laft night from London to Gofport in the {tage-coach : one of the paflengers, a woman, was extremely deaf, A few weeks before, I had travelled in a fimilar ve- hicle with an unentertaining companion of the fame kind. My attention has been thereby turned to the fubject 5 and I am led to make the following remarks :— For that deafnefs arifing from impaired excitability of the organ of hearing, properly fo called, I know of no remedy : I confine what I have to fay to that fpecies of it which is occafioned by a difeafed ftate of tympanum, or the external meatus. In either of thefe laft cafes founds communicated by the external ear appear to be of a lower pitch than in reality they are; while, if the Euftachian tube continues permeable, thoie communicated through the mouth appear higher and louder than ufual. Even where the ear and all its parts and paf- fages are in health, founds communicated through the mouth are more perfect than thofe which pafs through the external meatus. This, perhaps, is occafioned partly by the con- -eavity of the mouth, and partly by the folidity of the teeth. In perfons whofe tympanum, or whofe external meatus is difeafed, it is probable that the ear, from habii, becomes more fenfible to the vibrations of found com- municated through the Euftachian tube, than, without fuch a circumftance, it otherwife would be. Sound being more eafily communicated through the me- dium of folid than of rare bodies, I apprehend that a long wire held in the mouth would be much more feryiceable to fuch a deaf perfon, than the largeft trumpet applied to the external ear. . Jt poffeffes alfo the advantage of being extremely portable, and 380 On the Affaying of Ores by Fufion. and may at all times be ufed without inconvenience, and almof without being obferved. . I fhall certainly make trial of it m the firft cafe that occurs. ' XI, On the Affaying of Ores by Fufion, By Mr. Davin Musuet of the Clyde Iron Works, Communicated by the Author. My Paper in the Number for July concluded with a table of the proportions requifite to obtain, from all the va- rious iron-ftones, an accurate affay ; the perfection of which is always indicated by the fuperior tranfparency of the flux, and the fuper-carbonation of the metallic button. By feru- puloufly following thefe and fimilar proportions as the ext~ gencies of the ore may point out, crude iron will always be obtained of the fineft quality, carbonated beyond whatever is produced in the large way of manufacture, and its furface covered with a beautiful carburet of iron, either in fmall fhining {pecula, or in the ftate of a thin membrane. By a flight gradation of change in the proportions of the com- ponent parts of the flux, the metal of the fame iron-ftone may be made to pafs through all the inferior ftates, Since, then, all iren-ftones in the affay-furnace may be made to give out their iron at pleafure, of all the various qualities, it is furely erroneous to affert, that fuch and fuch iron-ftones contain fach and fuch qualities of iron; that this one affords metal of the fineft quality, while that, on the contrary, yields iron fit only for forge-pigs or ballaft; yet this is the univerfal Janguage in the manufactory. In this, as in many inftanees, we accommodate the language to our ideas, rather than our ideas to truth. The fuflrage of pre- vailing euftom has imperceptibly affaciated with our ideas many abfurdities which we are afterwards afhamed to ac knowledge, and which darken the gleam of truth, or render u On the Affaying of Ores by Fufion. 381 it apparently ridiculous, merely becaufe it is at variance with our prejudices, Where fcience guides not the manufacturer, or is feomed by him, his train of reafoning, though far from being juft, is fhort; it is fitted to the narrow culture of his mind, and confonant to a barbarous nomenclature of re- ceived ufage *, In order to clucidate ftill farther how much the quality of the iron is dependent upon the proportions of the mixtures, in combination with, or given to the ores, let a determinate quantity, fay an ounce, of the oxyde of pure malleable iron be taken;—this we are phyfically certain contains no mixture except oxygen exifting in quantity proportioned to the ftage of oxydation, the quantity being afcertained by its degree of obedience to the magnet; when the quantity of oxygen given * [cannot refift noticing one inftance, prevalent at iron-works, of that blind reverence to the opinion of our predeceffors, whofe fources of know-~ ledge muft neceflarily have been few and contraéted, When fuper-car- bonated crude iron is run from the furnace, it is frequently covered with a feurf, which when cold is found to be a coating of plumbago (carburet ef iron) remarkably brilliant; fometimes in fall fpecks, and at other times in large flakes: this fubftance is univerfally denominated /idphury and, as the moft expreflive adjective for that quality, we fay that the irom is fulphury. Tihere are- not, perhaps, two fubftances fo oppofite in thei degrees of inflammability, or fo widely different in their properties, as fulphur and plumbago; the cxiftence of the latter almolt wholly fuppofes a total abfence of the former: ‘yet, fuch is the want of inveftigation, or the flightett momentary refleétion, that an indolent belief is paffed as to the prefence of a fubttance diametrically oppofite to that which is expreffed. Sulphur has hitherto-becn the philofopher’s tone of the iron manufaétory 5 to its prefence is attributed the produétion of bad iron—when the metal is in its moft valuable ftate, it is alfo_/w/poury ;—it prevents caft iron from becoming malleable; and if /x/phur were altogether abfent, hard or white caft tron could not be produced. If caft iron is found coloured, it is by the /wpbur ; is it cryftallifed and coloured, then it has fulphur to excefs; fhould it have loftits fireagth, or have become loofe in the fra@ure by an excefs of thrinkage in large caftings, till it is by the agency of fulphur: in thort, in every procefs in the manufacturing of iron, fulphur explains the whole phenomena! it is execrated in one procc{s, and anxioufly looked for in another. to & 7 382 On the Affaying of Ores by Fufion. to it, by the decompofition of water, exceeds 25 per cent. few traces of magnetic attraction are perceptible :—introduce this oxyde into a covered crucible, without any addition, and expofe it to a violent degree of heat for 40 minutes, (longer m proportion to the quantity,) a button of highly oxygenated erude iron will be obtained: if the heat is continued longer than is neceflary to effect this, a fmall mafs of malleable: iron will be found occupying the bottom of the crucible. The produce in either cafe will be fhort of the real quantity of metal contained in the oxyde. When oxygenated crude iron is obtained, the ore from which it is produced, to ufe the common phrafeology, is faid to contain bad iron, That this has no relation to truth, will be feen by takimg another portion of the fame oxyde; let it be mixed either with chalk or lime, and a little hottle-clafs, to conftitute fufibility, and expofed to a fimilar degree of heat with the former; the whole contents in iron will then be found revived, and oc- cupying the bottom of the crucible in the ftate of fine car- bonated crude iron. Here then is a complete alteration in the quality of the metal, though obtained from the fame ore; for we cannot confider iron combined with oxygen, to which earthy bafes are given, in any other light than that of an ore. Again, let a portion of mixture, exaétly fimilar to the Taft, have added to it double or triple its weight of bottle glafs, and fubjeét the whole to an equal heat with the for- mer experiments, nearly a complete revival of all the metal will be found to have taken place; its quality, however, will be highly oxygenated and brittle. Such experiments clearly demonftrate, that the various qualities of crude iron are en- tirely owing to the mixtures in the ore, and their treatment; -and that iron, confidered as a fimple metallic fubftance, is the fame in point of quality in all ores. If iron was originally formed in a metallic ftate, its pro- perty of decompofing water, whether cafually expofed to a moift atmofphere, or removed at various depths from the furface, furnifhes an hypothefis as to the primitive principle 5 of On the Affaying of Ores by Fufion. ° 333 of iron ores; that part of the water—by far the greateft— which remained undecompofed, would ferve as a medium, or vehicle of fufpenfion, and conveyance to the oxyde; this again, in its turn, would be depofited either at the fountain- head, or at a greater or leffer diftance from it, according to the affinities exerted upen it by other fubftances with which it might come in contact. Correfponding with this fuppo- fition, we commonly find thofe ores which are, formed in vertical mafles or knobs, approached by a great number of fmall veins occupying the fmalleft fiffure or crevice in the rock, Time, and the re-action of additional water and acids, would a fecond time carry off a portion of the ore in chemical union; this, by the exertion of new affinities, would become precipitated, and mixed with the fufpended earths, to form regular ftrata-of iron-ftone. _ To fuch a pri- mary and fecondary agency of formation may be attributed the general fuperior richnefs of ores found in irregular ver- tical maffes, to that of iron-ftones. The fame caufe will alfo explain why more determinate qualities of iron are ob- tained from primitive ores, than from thofe of a fecondary formation. In the former, the mixtures are commonly fewer, and the quality of the malleable iron more decided ; » ¥ in the latter, the quality of the metal 1s lefs certain, and more various, from the mixtures being more numerous. Hence we may alfo trace the reafon of the fuperior qualities and marks poffeffed by fome of the foreign fabrics over cack other, where the fame fuel has been ufed, and the fame courfe of manufacture followed. Having fo far confidered crude iron, in regard to its fufi- bility, and the facility with which it becomes changed into _ various degrees of carbonation or oxygenation, conftituting * avariety of qualities moft pointedly diftinguifhed in com- — merce, and in which the metallurgift difcovers widely dif- ferent properties and charatteriftic forms; I fhall next pro- _ ceed to mention in what manner ftrength may be given to any quality of crude iron which may probably be obtained by ta. On the Affiying of Ores by Fufion. by the fufion of an ore, and from what fource this property is derived. Upon a former occafion I have mentioned that iron, ob- tained from argillaceous ores, pofleffed a degree of ftrength beyond that obtained from the other genera. This truth” daily prefents itfelf to our obfervaticn in the large feale of manufatture ; and however erroneous the reafoning of the manufacturer as to the catife, yet fo evident are the confe- quences produced, that we muft immediately attribute them to fome fource beyond the cafualties of operation in the {melting furnace. In the explanation of this faét, as on the degrees of oxygenation and carbonation in general, the ma- nufacturer has recourfe to the exiftent nature of the iron in the ore, and denominates the metal contained in fuch and fuch an ore to be * ftrong, coarfe, ill-melting iron ;” of “¢ weak, tender iron, poffefling no body.”” That iron-ftones and ores yield, in the operation of {melting, different quali- ties of crude iron, as to ftrength, is an undeniable fact; and that the fame variety attaches to iron when converted to malleability is a truth daily evinced in our forges: yet thefe fa&ts by no means entitle us to conclude, without farther in- veftigation, that thefe varieties of ftrength are the hereditary property of the priftine formation of the metal. This in- ference accords with a hafty view of the matter, and a bare comprehenfion of effects, without tracing to its fource the modifying principle of the whole. The theory which fT have adopted, and which in every ftep I have found fup- ported by numerous experiments, upon different feales, and by along courfe of practical obfervation, explains to me, with much more eafe and harmony, the whole phenomena of quality in ores and iron-ftones. To illuftrate that part of my theory relative to ftrengtlh, Jet the preceding experiment, wherein carbonated crude iron — was produced from the oxyde of pure iron, be repeated with the addition of a little pure clay. If the clay added be half the weight of the lime alfo ufed, the iron will be found, - when a On the Affaying of Ores by Fujion, 385 when fubjected to the gauge, much fuperior in ftrength; and if the experiment be accurately performed, the metal will be but a little reduced in point of carbonation. The follow- ing proportions will give accuracy to the refult :—Oxyde of iron, 4 parts—Lime, 2—Clay, 1—Glafs, 3= 10 parts. By mixing clay with the flux in all experiments, the f{trength of the crude iron is improved. This point may be urged fo far as to form, by an extra-addition of clay, a flux of difficult fufion ; in which the iron becomes fulpended in globules, which are partially malleabilifed apart from each other. Crude iron, obtained with a fuperior mixture of clay, in all its ftages of quality, poflefles a greater degree of ftrength than iron from calcareous iron-{tones. Iron from argillaceous iron-ftone is reckoned ftrongeft when carbo-oxygenated ; that extracted from calcareous iron-ftorfe is reckoned to poffefs moft ftrength when oxygenated, mottled. I would far exceed the aes of the prefent communication, were I to enter fully into this curious fubje&t, and particularife the different refults obtained by the fufion of ores with different earths in various proportions: all my experiments have fully proved to me, that originally the quality of the iron, fimply confidered, «was the fame; that, as it underwent change by decompofition and new combination, it became united to foreign fubftances, poffeffing widely different properties ; and which mixture, by a general fufion, imparts to the metal va- rious properties, feldom homogeneous, but frequently other- wife: in fhort, that the numberlefs mixtures with which it is combined are not neutral in fufion, but corivey an altera- tion to the quality of the reduced iron. I hope. to refume this fubject when my experiments will be more extended by the examination of a vaft variety of iron-ftones, and fhall then point out the confequent effeéis of their application to the manufacture of caft and malleable iron. The affaying of primary ores comes next under confidera - tion. Thefe, I have already faid, poffefs a much greater di- verfity of external chara¢ter, as well as internal variety, than Vox. IV, Cec thofe 386 On the Affaying of Ores by Fufions thofe of iron-ftone. When affayed with a vitreous flux, - either of falts, alkalies, or filex, the refults are rendered very” uncertain and erroneous: when pot-afh, tartar, &c. are ufed, | the crucible is often deftroyed, and the compound entirely» loft: when bottle glafs and a mixture of thefe are ufed, the - fcoria formed is fo very black and ponderous as to give the | moft prefumable indication of the fecretion of metallic oxyde: this is afterwards verified by fufing the mafs with a mixture of dried chalk and charcoal, a globule of metal will be obtained, which evinces the richnefs of the fcoria; this, having loft its colouring principle (the metal), becomes clear and tranfparent. The refults from thefe ores by fufion afford various products, and lead to different conclufions: I fhall miention feveral of them. The Cumberland iron ore, when introduced into a cru- cible without any additional mixture, fufes eafily, and forms an opaque fcoria, internally of a black colour, but towards the furface covered with fine fhades of brown: this arifes from a partial oxygenation of the femi-revived metal while cooling, and is often injured by a frefh combination of oxygen. If the crucible remains found, and the melted niafs is kept in a ftate of extreme divifion for an hour, a confiderable quantity of metal will be found precipitated, but fo highly oxygenated as to fhiver to pieces if expofed to air before it is entirely cooled. If, when the crucible is taken from the furnace, it be flightly inclined to one fide, and the vitrtfied fluid entirely removed from the furface of the metal, a violent deflagration will immediately enfue, the ejected globules will be thrown three feet upwards from the mouth of the crucible: if the quantity of metal does not exceed 500 grains, it will totally difappear, except a rough dark- blue oxyde in the bottom of the crucible, not above r-4th_ of the original weight. The metal thus oxydated will be found in {mall fpherules of a blackith colour, and fpongy around the fpot occupied by the crucible. This curious appearance is in fact a combuftion of iron’ by ~ omnes “oe On the Affaying of Ores by Fuffon. 387 by oxygen gas, furnifhed by the decompofition of atmofphe- ric air: itis an operation which the accurate obferver may daily fee manifefted in almoft every department of the foun- dery anid forge. By a juft comprehenfion of it, arid.4 proper appreciation of its effects; we have a key for the elucidation of the fource and aétion of many facts long wrapped in myf- tery, or which have beer explained upon principles deftitute of ftability, and unallied to the fundamental operations of truth. In place of withdrawing the crucible immédiatély upon the feparation of the crude iron, were it to remain for an hour longer under an inferior degree of heat, fo as to confo- lidate the metal without again fufing it, then the whole mafs would be found malleable; the fcoria light and porous. In one of my experiments upon the hematites variety, I ob- tained from 1 |b. averdupoife, or 7000 Troy grains, an ingot of fine malleable iron weighing 4486 grains ; a bane equal to 64 per cent.* An oxygenating flux was however ufed, and nearly the whole contents in iron previoufly revived. In experiments without the addition of a flux, the tranfmutation from caft to malleable iron is fhortened, but the produce is not more than 5-8ths of the intrinfic contents of the ore. Even this procefs may be confiderably fhortened by removing the cover- ing of vitrified earths floating upon the furface of the metal: thus the {mall portion of the carbonaceous principle contti- tuting fufibility is almoft inftantly carried off by thé com- bination of oxygen; the metal lofes its fluidity, becomes ‘thick and clotted, and more fpeedily paffes into the mralle- * This might be adduced as a proof that crude iron contains more parts . congenial to malleability than is generally admitted, or than is manifefted in the operation of converting it into malleable iroti at the forge: the lofs there has already been mentioned to amount to from 30 to 50 per cent. of _ Peal metal ; in this affay, however, the produce in malleable iron was only 415 lefs than when accurately affayed, and rich carbonated crude iron was obtained ; in which, too, the carbon conftituted a part of the weight. Cex able 388 On the Affaying of Ores by Fufiort> able ftate. In this procefs the quaritity of malleable iron ob= tained is ftill lefs than in the two former: the furface of the. metal being expofed by the removal of the fcoria, oxydation: takes immiediate effeét ; and whilft malleability is pervading the under furface of the metallic button, the upper one be-. comes reduced to a blackith blue oxyde. In this operation a ftriking proof is afforded of the great affinity which oxygen: has, in high temperatures, to caloric. Were the futface of fuch highly oxyg genated crude iron expofed, while fluid, te: atmofpheric air, at an ordinaty medium, for 1-6th’of the time, its whole metallic properties would: be completely de-. ftroyed: in the prefent inftance nearly one-half of the metal ‘is preferved, although its furface is expofed to the action of a violent current of gas, ignited to the higheft pitch of white- nefs*. In the proper aflay of this ore I have found all the varieties * I have frequently obferved, in experiments with pretty deep crucibles, where the moft violent heats were excited, and where the fluid metal had affarned a whitifh-blue colour fomewhat inclining to azure, that the quan- tity of oxyde formed was imperceptible, and never vifible while the heat was continued of equal intenfity ; when this agent became lefs urgent, the furface of the metal became oxydated as ufual. When a regulus of crude iron thus expofed was wifhed to be obtained free from oxydation, a little dry charcoal was introduced into the crucible fo as to cover the regulus ; this prevented the aétion of the air from taking effet while cooling, and preferved the button {mooth.. During fuch expofures, when no oxyde was produced, I have noted a lofs of metablic parts\equal to 5.7, or 20 fer cent. when the fpace of time did not exceed one hour. Among feveral conjec-. tures refpecting the caufe of this deficiency in weight, and real abftraétion of metal, the two following have with me moft weight. _1ft, Either the meta! deflagrates in {mall particles, which are thrown out of the crucible in fpar- kles, made invifible by the tranfcendent brightnefs of the furrounding heat: Or, 2d, that in confequence of the fluid metal being expofed to fuch a great degree of heat, in contaé with oxygenous gas, part of it becomes acidified, and forms the ferric acid. The truth of this Jaft fuppofition will not eafily be afcertained, fince it will be difficule to conftruét an apparatus capable of rece1ving or containing it, fhould it pr rove to be an elaftic fluid: it is, how- ever, confonant to the doétrines of the new theory, and the poftibility of the exiftence of the ferric acid is by no means excluded. The diffipation of 6 r carbon “at aa On the Affaying of Ores by Fufion. 385 varieties fufceptible of various degrees of carbonation: for the moft part I have ufed chalk and charcoal for the reduc- tion of the ore into carbonated crude iron. In the hema- tites variety, for 11b. averdupoife I have commonly added 6 oz) dried chalk and 3-4ths oz. of charcoal; and for the {plinty blue ore alfo a fimilar mixture, From both of thefe Thaye-obtained the richeft fort of crude iron. In the manu- fastory thefe varieties are. always reckoned to produce the hardeft and moft infufible qualities of crude iron: when the wMIISD ~19% : carbon oroxygen will not nearly explain this Pyne pacing as they exift in mush lefs proportion ; ; and while the jron remains in a crude ftate, the lat- ter accumulates i in proportion as the former becomes expelled. Befides, a greater "product i in malleable iron is obtained by following the precautions formerly mentioned, than even of catt-iron when thus expofed. Now, as malleable iron is free from all mixture, or at leaft is malleable in propor- tion as it is unalloyed, it is obvious that the deficient weight is not made . up of cither oxygen or carbon. Inthe expofure of one particular button of crude iron, which loft 92 per cent. the furface was agitated in an uncommon and moft beautiful manner; a rapid motion from the exe tremity of the circumference to the centre of the fluid mafs took place; the motion feemed entirely rotatory, and peculiar to one common _ axis. The metal itfelf was of a blueifh green colour, and emitted from 7 its furface an azure-coloured gas, which preferved a diftin& form and co- i Jour from the common flames. This appearance firft led me to fuppofe the a prefence of the ferric acid, by which means the lofs of weight, when no vA Beye was vifible, would be eafily accounted for. To try, fo far, the i juftice of this conjeéture, i expofed tin, Jead, and zine, in different alloys at of thefe metals, to white heats, and found them diffipate in a much fhorter _ time, and with a greater difcharge of gas from their refpective furfaccs. ‘The fame effe&t was more fpeedily produced by introducing the pieces _ @pon the furface of hot melted crude-iron. Zinc, in this experiment, in- i - flames inftantaneoufly ; explodes with confiderable violence, and with the B AGneagement of a blueifh fame. Its known inflammable property may © add I little firength to this hypothefis; but the diffipation of lead and tin, without any refidue, would alfo lead to a fuppofition of the plombic and Mlannic acids being formed by a complete faturation of oxygen. The latter, _ being found formed by nature in a cryftalline form, does not entirely con- tradi& this idea ; for a difference in the dofe of oxygen, and of tempera- _ ‘ture, mutt alter the refult. 4 : Cc3 metal 39° On the Affaying of Ores by Fufion. metal is fubfequently manufactured into bars, it is ftated, ms different places to produce cold and hot fhort iron. The kidney ore will admit of a diminution of chalk, and: 2 {mall addition of glafs; 11b. averdupoife of this variety will be accurately affayed with the addition of 5 0z. chalk, 1 oz. of glafs, and 3-4ths oz. of charcoal. The fame pro- portion of mixtures will alfo accurately reduce the {mali pieces of this ore, commonly of a foft, greafy confiftency, mixed with {mall fragments of the hematites and kidney, and will give out the iron which they contain fuper-carbo- nated. A mixture of this foft ore with kidney i is preferred to the richer varieties at the iron manufattories. The Laneafhire ore chiefly confifts of this compound, and the poorer in iron has always a decided preference given it at the blaft furnace. The ftratified iron ore of the ifland of Iflay is of moft difficult fufion when treated without any addition. It fufes i into a blackith | green ponderous mals, and, even expofed to the higheft heats, lets fall but a {mall fhare of j its iron. The quality thus obtained is in the higheft degree oxygenated; its fra&ture is partially cryftallifed in lines which converge — towards the upper furface of the button, fimilar in eryftal- — Yifation to the fraGture of zinc. A regulus thus obtained, when divefted of its feoria, and properly expofed to the — action of the ignited gas, foon lofes its fluidity, and pafles into the tate of ftrong malleable i iron. If this operation is _ performed upon 4 large quantity, without agitating or turns | ing the mafs, the upper furface of malleable iron will early acquire the cold fhort quality, and will be fubjeé&, at the — fame time, to an uncommon w vafte by the rapid oxydation : of its parts. In aflaying this ore for the produétion of car- bonated crude i iron, the refults are obtained with confiderable ‘difficul ty; : feldom perfect till the fecond or third experiment, This is chiefly owing to the great varjety of quality i in the gratum, two pieces feldom being alike either i in appearance — or in reality, The inferior maffes yield from 44 to 48 per eet a j On the Affaying of Ores by Fufion. 301 “¢ent; and the fuperior qualities I have found as rich as 56 to 61 per cent. To obtain carbonated crude iron from the vicheft varieties of this ore, add to 1 averdupoife Ib. of it 4 ounces of dried chalk, 3 of bottle-glafs, and 1 of charcoal. This mixture will produce foft crude iron, pofleffing great ftrength, and an uncommonly large cryftallifed grain, The poorer qualities require an additional quantity of calcareous earth, to reftore the equilibrium loft by the fubftitution of filex in place of iron. This ore had a trial in the large way at Clyde Iron Works, but was found to yield Zed iron,with the x/wal proportion of fuel. ~~ Oppofite in its quality and refults is the beautiful ore of the ifland of Elba. This, when prefented toa requifite proportion of carbonaceous matter, to take up its oxygen, not only clears itfelf of this hurtful mixture, but alfo takes up a confiderable portion of carbon, which, in fufion, be- comes united to the metal, and conftitutes it perfeCtly car- honated, In experiments with this ore, I found that when 2 ounces of it were treated with 2! oz. chalk, 2 oz. bottle- glafs, and 4 oz. charcoal, the mixture was with difficulty reduced to a white glafs; which at no time had been fuffi- ciently divided to allow a general gravitation to the many globules of beautiful carbonated iron thus feparated. In fufion, therefore, per /e, the metal precipitated becomes greyifh, and, in many inftances, affords fimilar refults to a pure calcareous iron-ftone ; with this principal difference, that it abounds with nearly a double quantity of metal, whofe tendency to become carbonated is no-ways inferior to any iron-ftone of that clafs. A fmooth carbonated regulus will be obtained from this ore, by ufing the following pro- portions: Ore in a raw ftate, 2 ounces; chalk, 2 ounces ; bottle-glafs, 1% ounce ; and charcoal, } ounce. The fcoria refulting from this fufion will be of a light-blue colour, — clouded, and variegated like an agate, and very tranfparent, The great diftance of Elba from this country precludes the pofijbikity of ufing this ore in our manvfactories with any a Cc4 profit, 392 On the Affaying 9 of Ores by Fujfton. "profit, unlefs it could be brought home as ballaft, and delis ‘vered in the vicinity of any iron-work at 22s. per ton. The produéts obtained from it in the affay furnace, indicate, in an uncommon degree, how very valuable the quality of crude iton would be in the feale of manufacture, by its PP plication. The Norwegian, Danifh, and Swedifh ores, found in firata, refemble, in many points, the Scotch ore of the ifland of Tflay; in affaying them a fimilar treatment is neceffary. “Some of them are more fufible, and afford fingular qualities _ “of crude iron. When fufed with oxygenating fluxes, the metal produced is uncommonly hard and brittle ; exhibiting a fraéture ftudded with brilliant mirrors, diverging the light in fmall radii : even when fluxes are ufed, capable of con- veying carbonation, the metal exhibits this bright granulated fra&ture jn a great degree. One of the ores from the mine of Houban, upon being expofed a confiderable time after feparation, afforded a mafs of pretty good fteel. The pro- portions neceflary to affay thefe, with accuracy, fo intimately depend upon their richnefs, and the relative proportions of mixture with which the iron is combined, that the fame recipe can feldom be applied to more than one variety. As iron-ftones are more defined, and their treatment prefcribed by more certain rule, a knowledge of them will foon lead to a juft comprehenfion of the primary ores; a fecond experi- ment, therefore, with any of them, will be fufficient to point out the neceffary proportions for obtaining in the next affay carbonated crude iron. In one collection of Norwes — . gian ores I found the following variety :— Nor. No.2. ‘No.3. No.4. No.5. No.6. iS =' a5 - 35 - 47 = 55 = .63 fon 7 - 16 - 19 - If - 24 - 19 parts volatile 65 - 63 - 46 - 42 - 21 - 18 earths ‘I00 100 100 100 100 TRO hig Pe eS On the Comparative Heighi of the Mountains, &e. 398 This fimple table will fhew plainly how neceffary it is to gecommodate the flux to the variety of the ore. If from this collection you with to obtain carbonated regulus, it is Obyious that, in order to faturate them equally, the iron contained in No, 3 ought to be prefented with double the quantity of carbon neceffary to carbonate No.1; No. 5. with a triple quantity ; that of No. 6 with more than 3!: and as I have proved that this effect will be chiefly produced with the ufe of a calcareous earth, it will at once be con- ceived how far this fubftance is to be ufed as the inftrument of alteration. In the recipes adduced in this and the preceding paper, I have always noted charcoal as a conftituent of each mixture. Since I difcovered that the contact of calcareous earths con-~ yeyed carbonation to the metal, by the decompofition of the garbonic acid, I havé reduced the proportion of charcoal commonly ufed in the flux, and have, in the treatment of moft iron-ftones, even abandoned it altogether: however, as my experiments have not yet extended univerfally to primary ores, I have, in the mean time, retained it as a conftituent part of the folvent. : XII. On the Comparative Height of the Mountains of the Earth, the Moon, and Venus *, . ScHroETEr, the learned aftronomer of Lilienthal, whs has feveral excellent telefcopes by Herfchel, publithed fome time ago a work on the height of the lunar mountains, as compared with thofe of the earth ; and lately he bas pub- lifhed a new work on the height of the mountains of Venus. Faujas, who not long ago undertook a journey into Ger- many, of the utmoft importance to the feiences, brought back with him thefe two works of Schroeter. We there fee aq he manner in which that indefatigable aftronomer makes # From the Yournal de Phyfique, Prairial, An. 7. . his 394 Defeription and Uje of } his obfervations. It is by the projection of the fhadows formed by thefe mountains when they begin to appear on their horizon in regard to us, or when they are about to difappear below the horizon. He diftinguifhes the moun- tains into different orders. The plate in Schroeter’s work confifted only of outline, and he exprefled the diameter of the three globes merely by ftraight lines. The annexed delineation (See Plate VIII.) was drawn by Alexander Fanjas, the fon, who to military talents unites a ftrong attachment to the fciences. He has rendered the height of the mountains more juft, and, from his drawing, the refpec- tive magnitude of the three globes can be better eftimated. Tt is here feen that the moon, which is about forty-nine times. fmaller than the earth, has mountains more than 4000 toifes in height *; while that of Chimboraco, one of the Andes in South America, the higheft mountain of our globe, is little more than 3000. V enus, which is lefs than the earth by a ninth, has mountains: 23,000 toifes in height. It muft here be remarked, that the higheft yountains on thefe three globes appear ail to be volcanic. XIII. Defcription and Ufe of a new Portable Inftrument. for afcertaining the Comparative Strength of Gun-Powder. By C, REGNIER f. Iw the proceffes employed for the improvement of gun- powder, it is neceflary to make comparative experiments 5 and various ingenious inventions, which it is unneceffary to defcribe, as they are well known, have been ufed for that * The French toife is to the Englifh fathom as 1 to 1°0664. + From Mémorres expiicatife de Dynameter et autres Machines inventées par C. Regnier, 4to, Paris, An. VII, The inftruments here defcribed are, ": The dynamometer, of which a plate and defcription were given in the Philofophical Magazine for September 1798 ; 2. A fafeguard for the prime Sng im mutkets: 3. The powdes-proof above-mentioned ; and, 4- An elec- sical machine. purpofe, ‘ f ity ig » Regnier’s new Powder-Proof. 395 “purpofe. I fhall, therefore, only obferve, that trials of gun- powder on a large fcale are always the beft; but as fuch experiments require certain kinds of apparatus and conve-~’ niences which are not always at command, a {mall powder- proof, in the form of a piftol, the blaft of which drives a fmall toothed or turned wheel that rubs againft a fpring, and is moved through a greater or fmaller {pace according to the ftrength of the powder, has been long ago adopted and brought into common ufe. This machine, however, is very defective in regard to the refults which it gives, and can de of no utility when an abfolute or approximate indication ig required of the relative ftrength of a given weight of powder intended for fire-arms, which are loaded with quantities determined in this manner: thefe proof-inflruments have indeed an arbitrary graduation, and their friction varies ac~ cording to the-firength of the {pring and the cleannels of the mechanifm. To obviate thefe inconveniences, I made feveral experi- ments, which led me to a more valuable and accurate prin- ciple; and, with fome variations, I at length fitted a {mall brafs cannon to the {pring of a common weighing inftrn- ment. By this application I was enabled to weigh the effort of the blaft, and confequently obtained a comparative method of afcertaining its aétion. This inftrument is at- tended likewife with this valuable advantage, that it a€s without friction. Its graduation is accurately determined, becayfe it exprefles the weight which ferved for that pur- pofe; and it may likewife be applied for weighing fuch bodies as come within the limits of its feale. A perfpective view of this inftrument is seyret, {Plate IX, fig. 1.) BC isa fpring bent fo as to form an angle ; 3 D a fmall brafg cannon capable of containing ex- attly 151 grains of fine gunpowder; E the graduated are, each divifion of which is nearly equal to 2" pounds aver- dupoife, and terminating in a {crew that ferves as a breech pin to the cannou,. F is a cap which may be confidered as the 396 Defcription and Ufe of Regnier’s new Powder-Proof, the body to be projeGted. It clofes the mouth of the {niall cannon, upon which it preffes with a force equal to four Kilogrammes. This eap is ftrongly faftened to one of the fpring radii by a nut at the oppofite end of its tail. G is a piece of ftrong brafs wire, fixed to a projeGtion, which, by means of a {mall ferew, is riveted into one ‘of the radi, -H, an index of woollen cloth or leather, which flides with a gentle fri€tion on the wire, when the branches of the {pring are prefled together by the explofion of the powder. This index remains at the place to which it has been pufhed, and fhews exactly how far the fprings have been made to ap- proach. When the inftrument isto be ufed, the two ex- tremities of the fpring are to be preffed together, to feparate the cap from the mouth of the cannon, into which powder is poured, till it is exa€tly full, by means of a card or a piece of paper. The ftopper is then fuffered to approach the muzzle gently, fo as ta clofe it exactly, without leaving 2 ingle grain of powder between them. The circular piece of eloth or leather, which fupplies the place of an index, is to be brought. into conta& with that branch ef the fpring to which the tail of the flopper is fixed ; and priming being put into the {mall pan of the cannon, it is difcharged, the inftrument being held fufpended by a firing or ribbon. The ’ effects of the explofion are, that, as the powder occupies a greater fpace by its inflammation, it drives back the ftopper, and the latter carries with it that branch of the {pring in which its tail is faftened. This branch cannot move, in regard to the other, which is made to moye alfo by the recoil of the gun, without driving before it the fmall index piece; and the {pace over which the index piece is carried will thew the force of the powder. The arches moyed over by the explofion of the different kinds of powder will fhew, by the number of degrees, the comparative f{trength of each. A ftar is marked on that arch which fhews the ftrength of powder of a mean quality; fo that the relative value of any fample, in regard to that medium, j Red Subfiance obferved on a Fijb- Pond in Norway. 497 “ fnedium, may be known. The friction of the index is the only friGion to which the inftrumient is fubjeét ; but it is fo fmall that it may be confidered as of no confequence. When the index is worrt out, its place may be eafily fupplied by a new one. _ It may be readily comprehended that, by adding a hook to the perforation at the extremity of the divided arc, and a ring in the eye of the ftopper, the inftrument may be employed for weighing. RIV. Account of a Red Subftance obferved on the Surface of _a Fifb- Pond in Norway, Hy Profefor H. StRoM *. Ix the {pring of the year 1790, a pellicle, or fubftance of a red Ehureas obferved on the water at one end of a fith-pond in Norw ay, which foon after began to fpread till it covered the whole furface. During dry and warm weather, the red’ colour was more perceptible than when it was cold and wet, It was more vifible alfo at noon, than in the morning and evening... I, how ever, did not pay much attention to it until the colour, about the end of June and the beginning: of July, became ftronger than it had ever been before; it was). ftrongeft at noon, and always proceeded, in regular order, from the end of the pond till it gradually extended over the whole furface. I filled a beer glafs with the water, which had a red appearance in,the glafs ; but the red matter foon depofited itfelf at the bottom, and the water became yellowith: for a long time, however,,it had a frothy pellicles, which was fometimes of a.red and. fometimies of a greem colour. I Jet fall a drop of this pellicle on my microfcopes, and beheld the fngular phenomenon exhibited m. the an-, nexed engraving, ‘(Plate IX, fig. .2.), which. pnegyaionte this, dyop as feen when magnifieden. i. djiw be vous lanine ena * From Tranfadtions of the Society of Natural Hiflory at Copenhagen, Vol, I. Part 2. oe i 9 I beheld 498 On a Red Subjtance obferved "I beheld partly large and partly fmall bubbles, refembling bright {pecula, furrounded by a dark rim or margin, whiclt were fometimes like fmall rings (1,1), and fometimes broader ; fo that the bright fpeculum in the middle formed the fmaller part (2,2). Every where around were feen an immenfe number of minute globules of the fize as repre- fented in the figure; confequently aftonifhingly {mall in regard to the fpecula, but fimilar to them in this refpect, that they had a bright point like a fpeculum in the middle. At firft, as far as I could obferve, they were black, or of 2 dark colour, the bright point excepted; but the red colour afterwards fhewed itfelf very clearly. In thofe that were red, the bright point was always feen; but this was not always the cafe with the dark ones. All thefe round bodies or globules appeared at firft, though very feldom, to have fome life and motion, but afterwards they entirely loft all movement ; and this was the cafe in particular with the red, which feemed entirely lifelefs. I could alfo clearly ob- ferve, that the red matter, which depofited itfelf in abun- dance at the bottom of the veffel, was nothing elfe than an affemblage of fuch round globules which had loft all life and movement. Befides thefe round globules with a bright point in the middle, I faw in the pellicle on the water, as well as in the water itfelf; another kind of living animals in greater numbers (3), which were fhaped like {mall fifh, and perfectly fimilar to the Cercarie virides of Miiller *, which produce the green covering on ftagnant water; but with this difference, that they were no larger than they are reprefent- ed in the figure, and that they had not a green but a dark appearance. I obferved alfo, though with difficulty, that the tail was forked ; and that fome of-them, clofe tv the tail, had a bright point or reflection, while the body before was not brighter than that of the Cercaria viridis. Thefe {mall animals moved with great alertnefs and vivacity in the © See his Animalcula tnfuforia, No. 130, p. 126. ~ drops 2 on a Fifh-Pond in Norway. 399 drops of water; but they collected themfelves fometimes together (5 and 6), and tumbled feveral times round in a circle (4). I obferved alfo, that, when they began to lofe ‘ life and animation, their longifh figure was changed, and they affumed that of a triangle or funnel, with a tail or tube (5). “Miiller obferved the fame thing in the Cercaria viridis *, and at laft they acquired the form of a globule, . which is reprefented alfo in Miiller¢. I have no doubt that thefe globules were the fame round animals, though -dead, of which I have already fpoken; efpecially as Miiller fays of his Cercariz virides, that they can affume a globular form. Of the bright points in the middle he fays nothing; and it appears fingular to me that he did not obferve them, as he viewed them much more magnified than I did. He fays as little of the red colour which they can affume and communicate to the furface of the water, and nothing at all of the bright bodies or fmall fpecula inclofed in round rims, which were perfeétly like the fmall round globutes with a bright point in the middle, only that they were fome hun- dred times larger. But I dare not affirm that they were of the fame kind, and only different in fize. It is very pro- bable that they confifted of the flime of the dead Cercarie, ‘which formed bubbles by means of the air inclofed in them ; for, that they were round like bubbles, appears from this circumftance, that they eluded every impreffion, and — fometimes divided themfelves into two or more fmaller bubbles, and even by 2 ftronger impreffion extended to a longith, oval, and irregular form like thofe marked (6), which fhews that they confifted of a tough flimy fubftance. Among fome {mall animals of another kind, feen fometimes in the drops of water, none were more confpicuous than the Bra- chionus urceolaris t, by its tranfparency, and the ‘three or- four round balls, or ovaria, which it has at the hind part of * Animalcula infuforia, Tab. 19, fig. 9. + Fig. 7 and 13. ’ ¢ Miiller’s Animalcula infuforia, No, 377) Tabs 50. fig. 15-21. its 400 On a Red Subftance obferved - its body. But what diflinguiflied it moft was, that, with the briftles or hair at the fore part, it often put the water m 2 fort of vortical. motion, which made the fmall lifelefs globular animals move quickly round in a circle, as if they had been alive (7). Such was the nature of this fubftance for a few days in July, till it increafed more and more; and I found, when I filled a glafs with it, a covering on the furface, of the thicknefs of the finger, befides the matter depofited at the bottom; but no living beings were now obferved im it, and not many of the dead globular animals: they feemed all to be converted into the above red flimy matter; the colour of which was perfectly fimilar to that of the bright yellow ochre ufed for painting houfes. What I have above faid will fufficiently fhew that the red colour of water, which has fo often been a matter of terror to the fuperftitious, may arife from the innocent infufion animals; and that animalcule, like thofe which I faw in frefh or fiagnant water, may be found in falt water or the fea, will be doubted by no one who knows that the latter has its infufion animals alfo. We oftem read in books of voyages, that the fea has fometimes had the appearance of blood, fometimes of fnow or milk; and that it has even fometimes had an appearance as ifon fire. All thefe phe- nomena ean be afcribed to nothing elfe than the foreign mat- ters, and particularly fmall animals, which multiply there in immenfe quantities, and are fometimes red, fometimes white, and fometimes of a flame colour, like Miiller’s Trichoda ig- mita*, without including the Nereis noéziluca, and feveral others. It feems to me highly probable that, in regard to colour, they may be fubje&t to different variations; as is the cafe here, from black to red, and even from red to green; as appears from this circumftance, that the red fkin or pellicle, after ftanding a few days in the glafs, was in fome parts greett. It is alfo probable that fuch fmall animals may arife fron * Anim. infuforia, No. 203, p. 186- the on a Fifh-Pond in Norway. 40L the fo called Grinfke, which in {pring is feen in the Nor- wegian feas; efpecially as it rifes or falls according to the heat or cold. ‘I'he uncommon colour in water, which I have here defcribed, is a remarkable phenomenon ; and, during the eleven years I refided in the neighbourhood, I never faw or heard of any change of the like kind in other fifh-ponds. I therefore paid more attention to it, and efpe- cially as in former times fuch appearances were confidered as portending wars and bloodfhed: but thefe’ fuperttitious notions muft lofe all credit when the above explanation is adopted, and when the fecrets of nature are more accurately explored, In regard to the caufe of this phenomenon [ mutt confefs that to me it is inexplicable; and that it is eafier to fay what it is not, than what itis. It is well known that the quality of the atmofphere, fome years, can produce worms and infeéts in incredible numbers: but what kind of weather is neceflary for the generation of thefe infufion animals, and whether a continual alternation of rain and fun-fhine, which was the cafe in the fummer above men- tioned, contributes to the phenomenon, is difficult to be determined. P.S. The red matter continued on the water during the whole month of Auguft, and feemed ftill thicker; but the red particles were fmaller, and feemed entirely deftitute of life. The corrupted and green water below fwarmed, on the other hand, with the cer¢ariz already mentioned ; which fometimes appeared of a triangular and fometimes of a cir- cular form, as already faid. Some green flime was obferved alfo in the red matter; which however did not proceed from the latter by a change of its colour from red to green, as I at firt fuppofed, but was either a flimy fubftance arifing - from the decompofed green cercariz, or fome other cor- rupted flime, which partly kept itfelf feparate from the red matter, and partly mixed itfelf with it and difappeared. At » any rate, I found in it no red, but here and there a fhrunk and wrinkled cercaria: but it muft be olaferved, that what I VoL. IV. Dd have, Pron . eunning, and roguery. The narrative of the immumerable : 40m On the fingular’ Sagacity ‘isd ot gti ] have, in tereral places, called black, may have been’ that dark green or almoft black colour which M. Miiller gives to his Cercaria viridis, and which, no doubt} would have fhewn itfelf under a microfcope of a ftronger magnifying power, if T had been in poffeffion of one at the time. KV. Odfervations on the fingular Sagacity of tbe Rock or Ice Fox *.- D URING my abode, fays Steller, on Behring’s iflatid, I had opportunities, more than enough, of ped ate the nature of this animal, far excelling the common fox m impudence, tricks they played us, might eafily vie with Albertus Julius’s: hiftory of the apes in the ifland of Saxenburg. They forced themfelves into our habitations by night as well as by day, ftealing all they could earry off, even things that were of no ufe to them; as knives, fticks, clothes, &c. They were fo meonceivably ingenious as to roll down our cafks ‘of ‘pro- vifions feveral poods im weight, and then fteal the meat out of them fo ably, that at firft we could not bring our- felves to afcribe the theft to them. As we were ftripping © an animal of its fkin, it often happened that we could not — _ avoid ftabbing two or three foxes, from their rapacity in tear- ing the flefh out of our hands. If we buried it ever fo care- fully, and added ftones to the weight of earth that was upon zt, they not only found it out, but fhoved away the ftones, as men would have done, with their fhoulders plying under them, helping one another with all their might. If, think-— : ; L ‘ : ; ing to fecure it, we put any on the top of a high poft in the i air, they grubbed up the earth at the bottom, fo that thell poft and all came tumbling down, or one of them clam- — -bered up and threw down what was upon it with ineredible — artifice and d&terity. They watched all our motiéns, and Jf * From Toke’s View of the Ruffian Empire. acco. 44 the Rock or Ice. Fox. 403 accompanied us in whatever we were sont 5 ad If the fea threw up an animal of any kind, they devoured it ere a man of us could come up, to our great difadvantage ; and if they could not confume it all at once; they trailed it away _in portions to the mountains, where they buried it under ftones before our eyes; running to and fro as’ long- as any thing remained to be conveyed away. While this was doing, others ftood on the ouard, and watched us. If they faw any _, one coming at a diftanee, the whole troop combined at once and began digging all together in the fand, till they had fo __ fairly put a beaver or a fea-bear under the furface that not a trace of it was to be feen. In the night-time, when we - flept in the field, they came and pulled off our’ night-caps, and ftole our gloves from under our heads, with the beaver- coverings, &c. In confequence of which we always flept with clubs in our hands, that, if they fhould wake us, we might drive them away, or knock them down. When we made a halt to reft by the way, they gathered around us and played a thoufand tricks in our view;' and when we fat fill, they approached us fo near that they gnawed the thongs of our fhoes. If we lay down, as if in- tending to fleep, they came and {melled our nofes to try whether we were dead or alive; if we held our breath, they gave fuch a tug to the nofe as if they would bite it off. On our firft arrival they bit off the nofes, fingers, and toes of our dead while we were preparing the crave; and thronged in . fuch manner about the infirm and fick, that it was with difficulty we could keep them off. Every morning we faw ' thefe audacious animals patrolling about among fea-lions _ and fea-bears lying on the ftrand, fmelling at fuch as’ were afleep to difcover whether fome of them might not be dead ; if that happened to be the cafe, they proceeded to diflect him immediately, and prefently afterall’ were at work in dragging the parts away. Becaufe the fea-lions at night, in their fleep, frequently overlay their young, they examine, as if tonfcious of that circumftance, every morning, ‘the whole Dd'a _ herd 494 Singular Sagacity of the Rock or Ice Fox. herd of them one by one, and immediately drag away the dead cubs from their dams. Seeing, now, that they would not fuffer us to be at reft night or day, we were in fact fo exafperated at them that we killed them young and old, and plagued them by every means we could devife. When the party awoke in the morning, there always lay two or three at our feet, that had been knocked on the head by fome of us in the night; and I can fafely affirm, that, during my ftay on the ifland, I flew above two hundred of them myfelf. The third day after my arrival, I knocked down, within the fpace of three hours, upwards of feventy of them with a club. They were fo ravenous that, with one hand, if we held to them a piece of fleth, they would come to it, although we might have a ftick or ax in the other to knock them on the head. When thefe bufy animals could not get hold of what they wanted, as the clothes we put off, &c, one of them would void his excrement upon it, and all the others which paffed would do the fame. From all circumftances it was clear to us, that they had had very little communication with human beings, and that the dread of man is not innate in brutes, but muft be grounded on long experience: ; In October and November they, like the other foxes, were the moft fleek and full of hair: in January and February the growth of it is too thick: im April and May they begin to _ fhed their coats: in June and July they had only wool on them, and looked as if they went in waificoats. In June they drop their cubs, nine or ten in a brood, in holes and cliffs _ of the rocks. They are fo fond of their young, that, to feare_ us away, they would bark and yelp like dogs, and thereby betrayed their coverts. This mode of preferving their young, — probably, has procured them the name of ice or rock foxes. No fooner do they perceive that their retreat is difcovered, than, unlefs difturbed, they drag away the young in their mouths, and hide them in a more fecret place. On killing the young, the dam follows the-flayer with grievous howl- Ings, Travels through Egypt and Syria. 405 ‘ings, day and night, for a hundred and more verfis, and never ceafes until fhe has played her enemy fome trick, or is killed by him. They ftink much more horribly than even the red foxes. In rutting time they run together day and night, the males biting each other, fram jealoufy, like dogs, When they cou- ple, they {cream like the cats, In ftorms and heavy falls of fnow, they bury themfelves in the fnow, and lie ftill as long as it lafts. They {wim acrofs rivers with great agility; will feize the fea-fowl by night an the cliffs when they have fettled to fleep; but are themfelves frequently victims to the birds of prey. Thefe animals, which are now in fuch inex- preffible numbers on the ifland, were moft. probably con- veyed there (fince there is no other land animal in it) from the Continent on the drift ice, and have been nourifhed by the great quantity of animal fubftances thrown up by the fea. This fpecies is entirely white, and their furs compofe a confiderable article of commerce. XVI. An Account of Mr. Brown’s Travels through Egypt and Syria, &c. [Continued from Page 247.] Ox the 28th of December 1792, Mr. Brown left Kahira to vifit Feiam, a city diftant about fixty miles to the fouth- welt. It ftands on the principal canal leading from the Nile to the lake Meeris, and is furrounded with cultivated ground producing that profufion of rofes for which this place was celebrated, and which were diftilled into rofe-water. The mode of propagating them was by continued layers; the young twigs thence arifing being found to produce the largeft and moft fragrant flowers. The rofe-water was ex- cellent, and fent to all quarters; but the cultivation is now running gradually to decay: wheat and other grain abound ya the vicinity, Dd3 After 406 An Account of Mr. Brown’s Travels After pafling three days at Feiam Mr. Brown proceeded towards the lake, of which he withed to make the circuit. Tt is the Mceris of Strabo and Ptolemy; and the teftimony of the latter living in Egypt feems unqueftionable. How- ever this may be, the lake now called Birket-el-kerun, pro- bably from its extremities bearing fome refemblance to. horns, fhews no mark, as fome fuppofe, of being the pro- duction of human art. ‘ The length, Mr. Brown fays, may ptobably be between thirty and forty miles; the breadth, at the wideft part he could gain, was 5000 toifes, as taken with a fextant; that is; nearly’ fix miles. The utmoft poffible extent of the circuit muft of courfe be thirty leagues. Se- veral fithermen, in miferable boats, are conftantly employed on the lake. The water is brackifh, like moft bodies of water under the fame circumftances. From Feitim Mr. Brown travelled fouth- eat, and at ies wara faw two fmall pyramids of unburnt brick. Returning to Bedis he paffed, the day following, the pyramids of Da- fiir; five of which appear fucceffively, befides thofe of Sa- karra. The third, after thofe of Hawara, is that of Medun, which has been very elegant. It is compofed of large pieces of the ufual foft free-ftone, joined together with a little ce- ment, and has been hewn off to a ftraight furface. It would be extremely difficult to afcend to the top, which is now very broad; but it is probable that there was another fquare com- pleting its fummit, which has been removed. The fourth is the moft foutherly of the four pyramids of Dafhar, where there are two large and two fmall. Itis in the form of a cone terminating in an obtufe triangle, and is now much damaged. At Sakarra a great number exift, among which ten are of a large fize * ve Siar: of tiie pyramids of Jizé, well known to 2!l who have vifited Egypt, Mr. Brown fays: ‘* An abfurd opinion has recently been fated, that the pyramids are hewn out of the rock on which they fand} but the firft ocular infpeétion would fet afide this, the joinings of the ftones being every-where merked with cement.” This is a flat contradigtion of what has been afferted by Bruce, DN On — through Egypt and Syria. 407 On the 1ft of March 1793 Mr. Brown left Kahira to, proceed to Suez, which he reached after a tedious progrefs ~ of five days. The town is fmall, and built of unburmed ? brick. It contains twelve mofques, fome of which are of: ftone, but the moft are mean buildings. The fea near the town is very fhallow, yet there is a fmall: yard for fhip- building. The Arab mode of conftruéting fhips is fingular. © They haye no art to bend the timbers; none of them are crooked, except naturally fo.. They are very | flender ; and, where the upper and lower ribs join, do not pafs over one another, but by the fide of each other. The fea here pro- duces few fifh. Oyfters, indeed, and fome others of the fhell-kind, are feen: the beft fifh do not come higher than Cofsir. Meat is fearce; bread of an inferior quality, and fometimes hardly eatable. Butter and milk are brought in fmal] quantities by the Arabs. Water is brought from three feveral places. It is always bought by the fkin, at a con- fiderable price ; and if a war were to arife with the Arabs, none could be found. é On the 8th of March 1793 Mr. Brown paffed the ford at Suez, and on the 14th arrived at Tar. On the 18th he left Tar, and on the 22d, at half paft three in the morning, reached the Monaftery of Sinai. The convent is large, with a good garden, to.which there is a fubterranean paf- face. Within the walls is a fimall. mofque for the conve- nience of the Arabs. The mountain now called Sinai is high and abrupt: on the north fide of it fome fnow was vifible. The whole is a very remarkable rock of red gr anite, _interfperfed with fpots to which foil has been brought by human labour, or wafhed down by rainy and in which grow, almond-trees, figs, and vines. Numerous rills of excellent water gufh from various apertures in the precipice, and wander among the little gardens, Sinai has two fummits : the higheit, it is believed, may be the Sinai of Mofes. The weather being very clear, Mr. Brown obferved from Mount Sinai the Eaftern Gulph of the Red Sea, which appears very Dd4 fmall, 68 An gots of Mr. Brown’s Travels ~fmall, and more round and fhort than is laid down in the Jateft maps. Mr, Brown returned to Suez and Kahira, without meeting any thing remarkable on the road. Mr. Brown’s views to the fouth of Egypt having been fruftrated the preceding year, he was reduced to the alter- native of abandoning any-further projects in that quarter, or of waiting for a more feafonable opportunity. This foon occuryed. He had formed a defign of penetrating to Abyf- finia by the way of Dar-Far, as he was taught to believe that he might hope there for the advantages of a regular government, and, with proper management, might expect every favour from the monarch. At the moment of his return from Afsdan to Affitt, the caravan of Jelabs from Dar-Fir, called Caglet-es-Soudin *, the Soudan caravan, arrived at El-wah. It was then reported, that the fale of their merchandize and flaves, of which they had no great quantity, would be completed in about two months, and that then they would return home. Their ftay, however, was protracted during the whole winter, and in the month of March 1793 they commenced their departure from Ka- hirqg for the Upper Egypt. They were flow in colleéting fuch things as were neceflary, and Mr. Brown made ufe of the time {fo allowed to. procure information from various quarters refpecting the journey. On the gift of April 1793 he fet out from Bulak, and on the eighth day, the wind having been often unfavour- able, reached Affidt. The firft cue was to provide camels for the route; bu unfortunately they were at that time fearce. He, however, at length obtained five at about 13}. each. A fupply of food was alfo procured for the journey ; and the caravan having aflembled, after about fifty day S, the expected mament " departure arrived. The party hav- ing left Affiat on the 25th of May, encamped on the moun- tain above it till the 28th. On the g1f they arrived at * Soudan, in Arabic, correfponds to gur Nigritia, merely g general words for the country of the Blacks. | Gebel | ay a ried,t > through Egypt and Syria. 409 Gebel Rumlie, a high rocky mountain which they were to defcend. It forms the weftern fide of the ridge, which con- ftitutes, as it were, the wall of Egypt, and the eaftern boun- dary of the low defart in which lie the Oa/es. It confifts of a coarfe tufz, and is of rugged and difficult defcent. They were employed four hours and a half the following morning in pafling from the foot of the mountain to Ainé Dizé, the firft place where water is found, and the northern extremity of the great Oafs. As a hot wind blew here during the meridian hours, the thermometer ftood at that time, under the fhade of the tent, at 116 degrees. In marching from Ainé Dizé to Charjé, eight hours were employed. They left Charjé on the 7th of June, and on Monday the toth arrived at Beirjs, On the 13th they proceeded to Mughefs, the laft village of the Oafis towards the fouthern defart ; which they left on the 15th, and on the 20th reached Seb. This place is marked by the production of a quantity of na- tive alum, as the name imports. The furface near which the alum is found abounds with a reddifh ftone, and in many places is feen argillaceous earth. Having left Seh on the 21ff, they arrived at Selime on the 23d. On the 24th they refted, and, continuing their route next morning, employed five days more in reaching Leghea, While they remained here, they felt much in- convenience from a fuffocating wind, which blew from the fouth, and raifed the fand in clouds. On the 2d of July the caravan left Leghea, and on the 8th, after a fevere and fatiguing march, reached the Bir-el-Malba, or falt fpring. The vicinity of this fpring js remarkable for the production of zatron, which appears under various circumftances, and is of a quality different from that of Terané, It is very white and folid, and, on immerfion in water, becomes hot, and difcharges a great portion of its air. Small quantities of it are carried by the jelabs to Egypt, where it is fold at a high price, and is ufed principally for making fnuff. The water found here is unpalatable and brackith, They 410 An Account of Mr. Brown’s Travels They remained at Bir-cl-Malha till the 12th, and on the oth encamped at a fpot called’ Medwa. "On the 23d they’ came to the firtt fprings within the limits of Far, whichiare: in. this place called Wadi Mafrik. The white ant; ¢ermis, was here exceedingly vexatious, building its covered way to every thing within the tent, and deftroying all within» its reach. This, together with the rains, which were now in- creafing, and began to pour in a torrent through the valley,’ obliged them to abandon their tents, and to take fhelter in the next village (Sweini), where Mr. Brown obtained an’ _ apartment in the houfe of Ali-el-Chatib, one of the princt- pal merchants eftablifhed in the country. There he {pent eight or ten days, and did not arrive at Cobbé, one of the towns to which the jelabs chiefly refort, till the 7th of Au- guft: A Melek, or governor, on the part of the Sultan of Dar-Fir, generally refides at Sweint; and there all ftrangers, * as well as merchants of the country, coming with the cara- van, are obliged to wait till the pleafure of the’ monarch in difpofing of them be known. . As Mr. Brown had come to the country under confi- derable exceptions from the general rule of merchants trad- ing to this country, and, in the Arabic language, rather as Daif-es-Sultan, the king’s ftranger, in which light he had been hitherto viewed by the natives, he expected to obtain immediate permiffion to continue his journey to the ‘royal refidence. ‘I obferved,” fays he to the Melek of Sweini and other public officers, “ ‘that, intending to vifit the Sultan, I fhould hardly have expected to be put back with ‘frivolous excufes, as the non-payment of duties which you dare not explicitly demand of me, and tributes, under thé name of prefents, which have never yet been exacted of any ftranger. If any duties be payable, beyond what have been already difcharged, you are perfeéily at liberty to detain all, or fuch part of the articles I bring’ with me, as you. may judge fufficient to anfwer your claim, but not-to refufe me permiffion to go to the Sultan, with whom I’haye bufinefs. Or, ee ee ee ee eee ee eee through Egypt and Syria. 4iL. Or, if other reafons operate to prevent my requeft from being complied with, and if any fufpicions prevail relative to my views in coming here, I defire, without further delay, to be furnifhed with the means of returning to Egypt, before I fuffer, as commonly happens to ftrangers, from the effects of the climate, while I am yet in the habit of travelling, and while the funds are yet unexhautted which fhould fupport me in my progrefs farther.” The mifreprefentations which had been made concerning Mr. Brown, and which had by this time reached the Sultan, manacled the hands of the Melek, and prevented his remon- ftrance from having any effect. Finding, therefore, no mode of advancing till the reft of the caravan fhould obtain the fame permiffion, he refolved to follow the example of the other jelabs,.and wait patiently the event. At length, after the expiration of about ten days, an order from the Sultan arrived, directing that all the jelabs fhould be allowed to proceed to their houfes on paying the duties affeffed on them. Before leaving Kahira, Mr. Brown had been apprifed that all commerce in Dar-Fur was conducted by means of fimple exchange. To carry on this, in fuch a way as not to be grofsly defrauded, he was induced to feek for a perfon who might go through this bufinefs for him, at Jeaft with fome fhare of probity. The perfon recommended to him for that purpofe had been a flave-broker in the market of Kahira; and though Mr. Brown expected from him that fubmiffion and obedience for which the lower claffes of the Kahirines are, externally at leaft, remarkable, he was difap- pointed in his expectations. The letters with which he was provided for different merchants inthis diftriét, under whofe roof he might have hada fafe lodging, could be of no ufe oo? till he had feen the Sultan ; for, till then, no perfon knew in what chara&ter to receive him. The objeét of this ‘man, therefore, was to prevent his introduétion to the Sultan, and to preclude him from any opportunity of reprefenting his cate, 412 An Account of Mr. Brown’s Travets cafe. They were no fooner arrived at Sweini than he found means to employ one of his affociates, who had been fome years eftablithed in the place, to go to the monarch and in- fufe into his mind fufpicions of him as a Frank and an In- fidel, who came to the country for no good purpofe, and whofe defigns it behoved him to guard againft. The villain himfelf was in the mean time not idle. As the houfe in whieh Mr. Brown lodged had no doors, he took advantage of this cireumftance, and his momentary abfence, to fecrete from a box, which he had broken on the road, a quantity of red coral. By the help of this commodity, Mr. Brown had expected to make his way to the Great. At the end of 2 few days, this agent returned, bearing a {pecious letter mmpreffed with the Sultan’s feal, ordering that no officer on the road fhould prefume to detain him, or take any thing from him, till he came to the houfe of Lbrabim-¢l-Wobhaifhi (the name ef this very agent) in Cobbé, where he was te reft himfelf «ll further orders, In this fituation, feeing no means of immediate reef, Mr. Brown began to feel impa- tienee, which, as he continued in a ftate of inactivity, com- miunieated the more rapidly its pernicious influence to his health. On the fourteenth day he was attacked by a fever, attended with extreme pain in the head. How long jt lafted he could not tell, having loft his recollection on the {econd day. It was afterwards recalled by the effect of a dyfentery, which lafied for twa days, and left him too weak to affift himfelf, A httle more than a month elapfed, when, the fymptoms appearing to diminifh, he again prefled to be permitted to vifit the refidence of the Sultan. But he had reafon to re- gret his impatience; for, having at length obtained leave, he proceeded to El Father only to repeat his fufferings. When he arrived at El Fafher, he was firft introduced to the Melek Mi/ellim, one of the principal minifiers. He received him with a rude ftare, as an objeét he was unufed te, which was followed by a {mile of contempt and averfion. He through Egypt and Syria. 413 He was feated, with fome more of the royal attendants, under a kind of awning of cotton cloth, on a mat {pread upon the fand. After the common falutations, the Melek and his company entered into converfation on the nature of his vifit to the country; while each made remarks en his perfon, and offered conjectures as to his charatier and in- tentions. At length a wooden bowl of polenta, and an- other of dried meat, were fet before them. Mr. Brown’s illnefs deprived him of all inclination to eat, and, obferving the company not much inclined to mvite him to join them, and yet embarraffed to avoid that ceremony, he relieved them by declining it, and defiring them to begin. When they were fatiated, a great number of foolifh queftions were afked him about Europe; fome of which he waved, and fatisfied them as to others in the beft manner he could. When he obferved that they crew tired of afking queftions, he feized the opportunity of explaining why he came there, and what favour he expected would be fhewn to him. ‘© Melek,” faid Mr. Brown, ‘* having come from a far diftant country to Mifr (Kahira), I was there made ac- guainted with the magnificence, the extended empire, and, above all, the juftice and hofpitality of the king Abd-el- rachman. Having been ufed to wander over yarious coun- tries as a derwi/b, I grew defirous of feeing Dar-Fiir. E was told that my perfon and property would be fecure: but fince my arrival within the confines, I have found all thefe affurances fallacious; my mclinations have been thwarted, my perfon treated with indignity, and my property plun- dered. J afk redrefs—I defire the punifhment of the man who has robbed me, and reftitution of what has been taken. Nor is this all; I particularly defire permiffion to go to Sennaar, in order to proceed to Habefh. I was prevented from going there laft year by the ftraight road. Habeth is a Chriftian country, abounding in flayes and gold: there are alfo many herbs valuable in medicine. Being there, I may cafily join my countrymen, merchants who come te Moccha, 44 Difappearance of Swallows in Auiumn. Moccha, in the Bhar Yemeni. I defire the Sultan will allow me to proceed thither; and, if it be neceflary, grant me his protection, and three or four perfons, deferving confidence, to attend me to the frontiers of Kordofan, I havea fmall prefent to offer him, confifting of fuch things as my circum- fiances permitted me to bring. I hope he may not refufe to receive it, and to grant me the favour I afk.’’—He anfwered : “€ Merchant, you are welcome to the Dar. The king is kind to ftrangers, and he will favour you in all you wifh, What- ever you want, you have only to demand. He has ordered a fack of wheat and four fheep to be fent you. At this time it is not poffible to pafs through Kordofan: the Sultan has a great army there; and when the country fhall be in fub- jection to him, you may pafs unmolefied. When you are admitted to his prefence, you will tell him who has robbed you, and) what you have loft; and he will caufe it to be reftored.’’’ It was now the hour of, prayer, and, when the company commenced their ablutions, Mr. Brown retired. [ To be continued. ] XVIE. On the Difappearance of Swallows in Autumn; in a Letter from Mr. PETER Core to Dr. pa i ikieh dated. New-York, September 25, 1798 *. In confequence of the epidemic now raging in this devoted city, I have not had an opportunity to give you a detail of what I intimated to you fome time ago relative to the dif- appearance of fwallows. In my early years, a number of my fchool-companions and myfelf ufed to make it a practice to hunt what ‘we termed Ground-Swallows (birundo riparia), in a bank in the neighbourhood of this city, contiguous to where the Jews burial-ground then was. In one of thefe boyith amufements I recollect two gentlemen pafled nearly by us, * From the American Medical Repofitory. ‘ j 7 . who — ‘ hi |. Lon 415 ... who ftopped and examined the birds we had dug out of the hill; whereupon a converfation took place relative to’ the ». migration of the fwallows. The. gentlemen both agreed that vf they were preparing for their winter quarters ; and one of >. them farther added, that he fuppoted that numbers of them _ kept in a meadow clofe by. hele obfervations made fuch {trong impreffions on my mind, that they have never fince been. erafed. “4 After; our revolutionary war was over, and my return “again into this city in 1783, in order to be convinced of the irath on)this, curious; and controyerted fubject, I made it a practice to walk around the Collect *, mornings and even- ings, im thefeafons when, they aflembled, in order to mark their flight or return again; but could not difcern any thing ‘©omaterial until the 3d inftant. As I was ftanding at my door “between the hours of five and fix in the morning, I obferved avery large flock! of fwallows flying in an eatfterly direétion. J immediately repaired to the pond, where there was already a vaft number colleted in the reeds and ruthes. _ They con- tinued coming for nearly the fpace.of half an hour, and vaft © numbers of them were flying over the water in almoft every direGtion. . Some of thefe birds appeared to run on the fur- ‘face of the water with great rapidity towards the eaft corner of the pond, and, in the twinkling of an eye, difappeared ' under the water and rofe no more. »* They feemed to crowd principally towards that particular :* fpot. But what is fomewhat remarkable, and deferves par- “ticular notice, is, that among them I, obferyed a number ou of white ones intermixed with the reft. While I was ftand~ * © ing on the edge of the pond:with my fpy-glafs, Mr. Brooks, bd “a particular acquaintance of mine, who-lives near the place, #9 Gime towards'mei I) mentioned my errand.to him, He ~?" food with ‘med confiderable titne, and faw the fame. I obferved to him that there, were white ones among them. atta, 3 cucelbaase Ye aespice antic Difappearance of Swallows in Autumn. — ; | ; * A pond of frefh water adjoining a marth i in the vicinity of the city of es New-York, He 416 Difappearance of Swallows in Autumtt. He replied, that they were feen three or four days ago. His word may be relied on as a man of ftri& honour and in- tegrity. Thus, Sir, I have given you a fhort fketch of what has come within my own knowledge, and what I earneftly wifhed to difcover. I hope I fhall not intrude upon your patience if I fubjoin an extraét from the Chriftian’s, Seho- lar’s, and Farmer’s Magazine *. It runs thus: * February 23, 1790. In Ulfter county, in the ftate of New-York, on an ifland in the Never-Sink-Creek, nearly in the latitude of 41° 30! north, a Mr. Baker, in the begin- ning of the month of March laft, having cut down a large hollow beech-tree, to his furprife found the cavity in the tree nearly filled with the common barn-fwallows (4irundo ruftica) of this country, in quantity (by his eftimation) nearly two barrels: they were in a torpid ftate; but carrying fome of thofe which were not injured by the fall of the tree near a fire, they were prefently re-animated by the warmth, and took the wing with their ufual agility.”,—This may be de- pended on as a fact. I take the liberty alfo to mention another relation from the American Mufeumt. It is taken from Mr. Jofiah Blakeley’s letter to Mr. Carey, dated Baltimore, January 7, 1788. As the piece is of confiderable length, I fhall only quote a few paffages from it. He begins thus : “« The hiftory of our common fwallows has long been a problem in ornithology. Whil{t people in general fuppofed them birds of paffage, a few, who appear to be better in- formed, fupported the contrary. The opinion of the many was founded on what they thought probable; that of the © few on faéts. In the year 1780 I was converfing with a : perfon, who lived about twenty miles from Bofton, on the phenomenon of the fudden exit but gradual and irregular return of fwallows. The gentleman to whom I made thefe — * Volume the Second, page 735. ¢ Volume the Third, page 452-2. b remarks, Meteoralogical Obfervations made at Padua: 4P7 remarks, replied, that they were not birds of paflage; and the caufé of their {adden difappearance, but irregular return, was, they had a fixed day for immerging in the water, but none for emerging from it. On my doubting his hypothefis, he told me, that as a neighbour of his, not long before, was draining a pond, on a warm day, near the feafon of the year in which the fwa!lows firtt appear, his attention was attracted by obferving the mud, which, in confequence of dratning the pond, had for fome time been expofed to the fun, move and appear animated; he then ordered a quantity of this mud to be conveyed into a room in his houfe, which he caufed to be gradually warmed by a flow fire. From this mud there foon arofe a number of fwallows, hovering over himfelf and family, who had been fpectators of their refur- rection. ) Thefe few obfervations, however iiperfe&t, may poflibly afford a large field for fpeculation to the philofophic mind, and Jead to ufeful difeoveries. For my own part, Tam now become a profelyte to the dorine of the {wallow’s remain- ing ina torpid flate during the winter, mot only from {pe- culative refearches; but from ocular demonftration *. ie sep XVIII. Meteorological Ob/ervations made at Padua in the Month of June 1783, with a Differtation on the extra- ordinary Fog which prevailed about that Time. By M. ToaLvof. Barometer —its greateft elevation was on the 24th and 25th of the month, wiz. 28 inches 4 lines; its greatett depreffion on the 16th, 27 inches 4 lines. In the fummer months there is generally very little variation in the baro- * Pennant, in his Bricifh Zoology, Vol. l- p. 414» feels difpofed to finile at the accounts given by Glaus Magnus, Derham, and Klein, of the fub- —merfion of fwallows, Let the phyfiologift and anatomift reafon on the miatter as they may, there feems to be pofitive evidence of the faé&t. 2. + From the Journal we Phyfigues You, lV. Re . mieter, 418 Meteorological Obfervations made at Padua. meter, and it remains almoft always flationary. It appears that it rofe very much after the fog, of which I fhall foon fpeak. THERMOMETER.—The month, in general, was cool: its mean heat, which commonly is 1g or 20 degrees, was this year only 161; for in the latter part of the month the thermometer did not rife above 22°6, and.in the beginning it was at 10. I fhall obferve that it fell four degrees between the 16th and 17th, owing to a ft6rm which came on. Hycrometer.—Notwithftanding the rain, it always pointed to drynefs; which proves the exaltation of the va- | pours. Raxrn.—If we confider the days when it rained little or a great deal, we ought to fay that the month was extremely rainy, for it rained twenty-two days: but the rain in ge- neral was not abundant, as there fell two inches lefs of water than ufual. This obfervation is applicable only to the Jevel country; for in the mountains the rain was exceffive, and occafioned a very great fwell in the rivers and torrents. ‘ But there occurred two particular phenomena to be ob- ferved, viz. the fog and thunder. On the morning of the 18th, after a ftorm, which had been preceded by feveral others, the fun appeared extremely pale through a light fog, which filled the whole atmofphere. This fog became ftill more condenfed the following days; and was not diffipated by the winds, nor even by the ftorm of the 26th in the morn- ing, accompanied by a great deal of thunder, which was heard all along the direction of the mountains from one fea - tothe other. This fog ftill exifted in the beginning of July, aud feemed to become thicker, at leaft at certain hours. It did not prevent the fun or fiars of the firft magnitude from being feen, except in the lower part of the horizon. People could look at the fun without being incommoded, and without ufing coloured or fmoked glafs. It appeared of different colours, according to the kind of rays which the difference in the denfity of the fog fuflered to pafs. As the yellow be WS RS eS Le es RE Meteorological Obfervations made at Padua. 419 yellow and red, being the ftrongeit, were thofe which pierced it ofteneft, the fun appeared like a ball on fire, or of a blood colour; which gave occafion to many whimfical people, whofe imaginations were heated, to fee there, as in the clouds, the figures of men and animals. Very often the | fun, in the higher part of the atmofphere, feemed pale and white by the abfence of feveral coloured rays; and he ap- peared red when he was lower, becaufe his rays then paffed through a greater portion of the atmofphere. That it may not be imagined that this phenomenon is new in the world, I fhall here give a fhort account of thofe obferved formerly, analogous to it. But it will firft be proper to fay a few words refpecting the caufe of this extraordinary fog, which I am inclined to think came from Sicily and Calabria, where there were violent earthquakes. We know, by the accounts given, that the heavens in thofe countries appeared cloudy after the great fhocks, which may be rea- dily believed when we confider the immenfe exhalations that muft have been difperfed throughout the atmofphere. In the month of June the fouth-eaft winds prevailed through- out all our country. Thefe winds at Venice are called Fu. riani, becaufe they firft take place on this fide of the gulph, It is very probable that thefe winds, traverfing that part of the atmofphere, may have carried with them a large mafs a, exhalations, which, being ftopped by the chain of the Alps, _ difperfed themfelyes in Lombardy, and occupied even the Alps, which people, with aftonifhment, beheld red, or 0, different colours, according to the pofition of the fun and oz the obferver. It does not appear that thefe exhalations arofe from our territory, which was not feen to fmoke, as is ge- nerally the cafe in the time of a fog; but it proceeded down- _ Wards, as if it had fallen from the atmofphere. It was not feen to touch the earth, except when, by an optical illufion, the nebulous ftratum, by being lengthened, appeared united with the fenfible horizon. It occafioned no hurt, therefore, to the fruits of the earth; it is faid only that it blafted the olives Eez and 420 Meteordlogical Obfervations made at Padua. and vines a little on the elevated grounds. If any fuffered in the flat country, the ¢aufe may be afcribed to the raine which took place at the time when they were in bloom. If this fog arofe, as I have faid, from exhalations difen- gaged at the time of earthquakes, it muft have been dry, and muft have contained abundance of earthy, fiery, mineral par- ticles, with a great deal of inflammable air and electric fire. To thefe may be afcribed the frequent thunder which took place, efpecially towards the middle of the month. The thunder in general made dreadful ravage, burning houfes and deftroying men and animals. Letters from Hungary ftate, that, after feveral fhocks of an earthquake, the city of Kremnitz was fet on fire by lightning. The fame fate was apprehended for Vicenza on the morning of the 26th, the repeated claps of thunder being fo violent. Five or fix houfes were that day ftruck by the lightning, which occafioned confiderable damage. The lightning fell alfo in about a dozen of places in the neighbourhood, particularly in the mountains. I fhall here fubjoin a fort of chronicle of the periods when the fun was feen obfcured by fogs; and I am perfuaded that many other inftances might be found in different authors. This notice will ferve to banifh every thing marvellous in regard to the fog of 1783; and to fhew that nothing hap- pens at prefent which has not happened formerly, and ever attended with more difagreeable circumftances. Epochs of the Sun being darkened, and of other fimilar Phenomena. Years of Rome. 2gt The fun darkened; a comet; fire in the heavens, (that is to fay, an durora borealis.) Julius Obfequens de Prodigiis. 542 Sun redder than ufual, being of a blood colour. .552 The dik of the fun appeared fmaller. 554 In the kingdom of Naples, the weather being ferene, the Meteorological Obfervaiions made at Padua, = 421 Years of Rome. the fun appeared of a blood colour, and the heavens as if on fire, (that is to fay, an Aurora borealis.) 710 Among the prodigies obferved during the year of Cefar’s death, is reckoned that of the fun being dark- ened, and appearing red. Cum caput obfcura nitidum ferrugine texit, . Impiaque zternam timuerant fxcula noctem. Julius Obfequens relates at more length the prodigies which appeared ; particularly torches feen in the heavens, and crowns furrounding the fun, which for feveral months feemed to emit only a pale feeble light: People, there- fore, could look at his difk. Years of the Chriftian era, 264 A great earthquake, and darknefs for feveral days.— Frifichio. . 346 At Conftantinople there were fuch extraordinary ftorms that the earth fhook, while the heavens feemed on fire. At that period people expected the end of the world, »90 And, according to others 798. For feventeen days the heavens afforded no light. This phenomenon was preceded by earthquakes in Candia and Sicily.—Col- le&t. Acad. de Lancil. Friftchio. g%7 ‘The heavens being ferene, the fun was darkened; and his rays, paffing through the windows, feemed bloody. 4020 The moon appeared of the colour of blood, and flames fell from the heavens like a tower, (that is to fay, a confiderable thunderbolt, or globe of fire like a carcafs or bomb full of grenades, fuch as is {aid to have been obferved this.year (1783) at the cathedral of Liege. if | am not mifiaken, Scheuchzer of Berne relates that he obferved one). According to hiftory there were gther cataftrophes : the fea left its bed, and inundated Ee3 feveral 422 Meteorological Ob/ervations made at Padua. Years of the Chriftien era. feveral places in the neighbourhood. The fame thig happened during the hurricane of March 11th this year (1783). 4104. The fun and moon in diforder were eclipfed feveral: times, (that is to fay, were obfcured :) there were feen, falling ftars, flaming fires, fiery meteors, lightnings, hail; typhons and hurricanes took place, which over- turned churches and houfes; deftroyed men, cattle, and plants; and occafioned great devaftation in the fields. This is exa&tly what happened in 1783. 4154 On the ift of Oétober, the fky, being ferene, ap- "peared all of a fudden quite darkened. 3206 - People imagined that they faw in the heavens a human head; and the following year, in Germany, the fun feemed divided into three parts. Similar pheno- mena may eafily deceive the imagination of men, which is generally confufed during fuch events, as was ob- ferved in 1783. 1227. An earthquake and comet—the fun of the colour of blood. : 1263 The fun obfcured, without any clouds, in fuch a manner as not to give any light. 1383 4 An earthquake in Swifferland. A large circle af- terwards around the fun for feveral days. 1549 There appeared in the afternoon, for three days in April, a globe all on fire. It is even faid, that armies had been feen fighting in the heavens before, and twa hions engaged. (Thefe were the fportings of the light of an Aurora borealis.) , < WX, Ob- { 423 ] XIX. Od/fervations on Pumice Stone, and the Place# where found. By Profefor BECKMANN *. ad UMICE ftone, pumex, pierre-ponce, pomice, is a porous, light, friable, rough kind of ftone, which floats in water ; neither firikes fire with fteel, nor effervefces with acids ; contains little or no iron, but fometimes more, fometimes lefs magnefia; and, in a ftrong heat, becomes fufed to glafs without the addition of any other fubfiance. On account of its fingular properties, an idea was entertained, even in the mof ancient periods, that it muft have originated in a different manner from other ftones. As it was found in many parts floating on the fea, the ancients confidered it to be a kind of hardened fea-feum ; as from the fame fuper- ficial grounds the bones of the cuttle-fifh, employed for many purpofes like pumice ftone, are called fea-feum alfo, More attentive obfervers, however, perceived that it was in- debted for its formation to the force of fire; efpecially as it was found, for the moft part, near volcanoes, and was ac- tually thrown up by them. It is now known with certainty, that real pumice ftone is a voleanic production, both that thrown up by the fea, and that found even in Germany, where there are no burning mountains. The latter kind is a proof that in thefe dif- tris there muft formerly have been volcanoes; and the former, of volcanoes fo near the fea that their eruptions could reach it. No place, however, abounds more with this kind of ftone than the Lipari iflands, particularly Lipari and Vulcano, from which, fince the earlieft periods +, all Europe has been fupplied with this ftone, and chiefly by the * A chemical examination of it may be found in Cartheufer’s Mixera- © logical Effays ; Bergmann’s Opufcula, LI. p. 197; and Achard’s Collegtion Of Phyfical and Chemical Effays, I. p. 58. + Pomices laudatiffimi fant in JEoliis infulis, Plin, Hit. Nat. lib. KXXVL. Cap, 255 Ee4 Sicilians. 424 Obfervations on Pumice Stone, Sicilians. Of thefe iflands we fhould have known little more than what has been told us in the fables of the poets, had they not been vifited, in the year 1781, by Dolomieu, who publifhed a mineralogical defcription of them * ; for all other travellers who have given accounts of Sicily fay nothing of them, partly becaufe they followed the common roufine, and wifhed to fee only fuch objeéts as had been feen by others—and partly becaufe thefe-iflands lie in a tem- peftuous fea, where to the danger of fhipwreck is added that ‘of being taken by the Barbary cruifers, who hover about in “that neighbourhood during the whole fummer. Travellers, ‘however, who wifh to fee more than antiquities, and who are defirous to examine and defcribe more than things al- yeady known, may here expect a rich harveft, if they are accuftomed to make obfervations in regard to natural hif- tory : for objects worthy of their notice cannot be want- ing in iflands where volcanoes of every kind exift, fome continually burning, and fome which, like Aitna and Ve- fuvius, are fometimes at reft, and fometimes in a ftate of violent eraption ; where there are others totally extinét ; and befides thefe, lava of all kinds, and in each degree of calcination, vitrification, and efflorefcence fF. The Lipari iflands, the Infule /2olia or Vulcanie of the ancients, lie between Italy and Sicily, but nearer to Sicily, from the coaft of which the neareft is diftant about thirty Italian miles. Dolomieu makes the number of them to be ten; others fay there are eleven. The largeft, which is the moft fertile and beft peopled, is called Lipari. It is eighteen Italian miles in circumference, and contains a * See his Voyage to the Liparine iflands. Compare alfo.F7aggi alle due Sicilie ein alcuie parti dell’ Apennino, dall’ Abbate haz» Spallanzani. Pavia, 1793, 8Vo. tom. ii. , + In regard to the precife fiimation of thefe iflands, fee Heman’s map : Sicilia, Sardixia, Corfica, Malia, 1762, confirvéted by Zannoni. On the» the shree-fheet map publifhed by Loller in 1770, under thg title of Mer Mediterranée, the land of Ufika is entirely omitted. faiall — Ne es. ee ere Se and the Places where found. 428 {mall town of the fame name. According to Dolomieu, it is the inexhauftible magazine from which all Europe ob- tains pumice ftone; and it has whole mountains of that fubftance, in which large holes have been cut without any perceptible decreafe being obferved. Next to Lipari, and neareft to Cape Melazzo in Sicily, lies Yulcano, nearly twelve Italian miles in circumference, and feparated from the former by a channel only one Italian mile in breadth, Its fire is never extinguifhed ; and it contains an inexhauft- ible ftore of pumice ftone, which has a perfect refemblance to that of Lipari. Some of it is collected for foreign trade ; but this uninhabited ifland is vifited, at prefent, merely on account of its wood, which grows on the fouth fide of an ancient crater. The pumice ftone, however, of thefe iflands, is very dif- ferent in regard to folidity, hardnefs, and weight; and it may be diftinguifhed into four kinds, one of which only is employed in foreign commerce. The firft is grey; has a clofe grain, imperceptible interftices and fibres; a confi- derable weight; great compaétnefs; and fomewhat of a vitreous fracture. This ftone, which can be eafily cut, is employed as corner-ftones for buildings, and for all kinds of walls in general. The town of Lipari is almoft entirely built of it.—The fecond kind is alfo grey; but lighter, more porous, and has more perceptible fibres than the former, gnd does not float in water. It is ufed for arches; and op that account great quantities of it are carried to Sicily and Naples.—The third is light, porous, and full of fibres; it floats in water ; has a filky appearance on the fracture ; and is compact and of a hard grain, which renders it exceed- ingly proper for polifhing marble and metals. This is the only kind employed in foreign trade—The fourth kind is exceedingly white ; of a very tender texture, and Jefs com, pact than the others. It feems to have reached the utmoft degree of extenfion, to which any fubftance can attain, for jts parts to retain a connexion. This kind is fit for no pur- § pofe 426 Obfervations on Pumice Stoney pofe whatever. When it falls into the fea, it floats offer to a great diftance ; and it may be found fometimes. on the coaft of Sicily and Calabria *: It is in general remarked, that the whiter pumice {tone is, it is always the lighter f. The moft common we of this kind of flone 1s for po- hifhing almoft every kind of fubftance ; and it is exceedingly proper for the purpofe, as it is foft enough to be rubbed to a fine powder; and yet its fineft particles remain fo rough that they can attack and wear down the furface of bodies without making feratches. The powder of vitreous ftones would alfo rub off particles by frition, but, on account of #ts acute edges, would leave feratches; and to pound it fo fine as to prevent this inconvenience, would require much more trouble and time than the pumice ftone; and even then, this fine powder of vitreous ftones would fuffer itfelf to pafs over the bodies to be polifhed almoft like argillaceous earth, without making any impreffion upon them. The workmen, who employ pumice ftone for this purpofe, ufe it either pounded, fifted and wafhed, or in whole pieces, as the hatmakers, curriers, and fome workers in metal. The laft muft choofe fuch pieces as have fine pores, and are fo large that they ean affume the form proper for rubbing or fcower- ing. On this account preference is given, in commerce, to that kind of pumice ftone which does not confift of too fimall pieces. In general, it muft be light, rough, friable, ef a grey colour, and free from fand or any other foreigry * Popowitfch, in his Refearches relpecing the Sea, p. 347, obferves, that this pumice ftone is caft by the weft wind on the Calabrian shores, and by the north wind on thofe of Sicily and Greece. He was told there: ; that it was a fubftance thrown up by the volcanoes of the Lipari iflands. But it may be feen, by Dolomieu’s account, that it never can be as article wf commerce, as Popowitfch thinks. + Cronftedt fays, in his Mineralogy, that the white pumice {tone is pro- duced from the black by its being bleached in the open air, But this is not he cafe : the white is of that colour when itis thrown up. "See Olafsen’s Reife durch [fand, ii. p. 103. Linnzeus, therefore, has been guilty. of an grror ik his Syf, Nat. iii, p. 181. ‘ x parts. and the Places where pao’: 427 seats; When it is to be employed as teeth-powder, it muft be pounded remarkably fine; and even then it will attack the teeth too ftrongly. In countries where pumice ftone ean be procured at a cheaper rate than among us, it is pounded and mixed with thie mortar ufed in building. This is done in Italy *; and the cafe muft have been the fame in former times, as pieces of it are frequently to be obferved in the mortar of ancient walls. It has this binding property in common with terras, pozzolana, and other yolcanic productions. From this cir- ¢umftance we might be induced to conjecture, that the ancients mixed fine ferra /igil/aris with pumice ftone goarfely pounded, and formed it into moulded maffes, which they dried in the fun, in order to make thofe bricks for building, which, as Strabo, Pliny, Antigonus Caryftius, Vi- truvius, and others f, tell us, with fome degree of wonder, {wam in the water; and that, on account of their lightnefs, they were peculiarly well adapted for many ufeful purpofes. They exprefsly fay, that the ancients ufed, in making them, the mineral employed for cleaning filver-plate, which we may confider to have been pumice ftone; though many other kinds of earths are fit for the fame purpofe. This conjecture has given rife, in modern times, to experiments which have not yet been attended with complete fuccefs. It will be difii- cult, indeed, to obtain bricks fo light by mixing clay with finely pounded pumice ftone, as it will ‘then fon a body too compaét and heavy. From a pafiage in the Travels of Peter Della Valle { one might be induced to conjeéture, that the art of making fwimming bricks was known at Ormus, an ifland in the Perfian Gulph, unlefs he meant perhaps to fay, that pumice ftone was employed there for building as in, * Labat’s Reife durch Italien, iv. p. 16. + Thie teftimonies of the ancients on this fubjeét I have given in a note to the Hiflorie Mirab. of Antigonus Caryftius, cap. clxxxvii. p. 228. t Della Yalle’s Travels. Geneva, 1674. fol. 3. p, 239. Sicily ; 428 Odbjervations on Pumice Stone. Sicily ; but in Sicily the heavy kind of pumice ftone, which does not fwim, is employed for that purpofe. .It is worthy of remark, that among the fo-called Etrufcan and other eartheri ware, as well as among thofe which were formerly brought from Japan and China oftener than at prefent, there were veffels much lighter and thinner than any that can be ma- nufactured in Europe. It is not improbable that Fabbroni may have been {fo fortunate as to difcover this preparation: at any rate, he not long ago laid before the Economical Society of Florence, for examination, a kind of brick, the fpecific gravity of which was not greater than that of the lighteft wood *. Moft authors, who give an account of pumice-ftone, {peak of it as if it were to be found in the neighbourhood of all burning mountains. This, however, is falfe; for it is not found among the produ¢tions of all volcanoes, but only near thofe, as the mineralogifts affert, the fire of which has arifen in fuch ftrata as have intermixed with them a great deal of feld fpar. It is found nowhere in greater abundance than im the Liparine iflapds, as already faid, though large quan- tities of it are found in Iceland; whereas it is very feldom feen near Vefuvius, and never in the neighbourhood of Etna. The ancients, however, {peak of Autnean pumice- * After T had written this article, I found in Gren’s New Phyfical Fournal, Vol. VI. part 2. p. 129, a paper tranflated from the Italian of Febbroni, by which it appears that he made his brick of a kind of earth dug up sear Santa Fiora, in the territories of Sienna, which neithér effer- vefces with acids nor is fufible in the fire, and which, according to his ex- amination, confifts of filiceous earth, magnefian earth, and aluminous earth, in the proportions of 0°55, oss, and o-12, This earth, therefore, feems to confilt of the fame component parts, and almoft in the fame pra- portions as the fo-called fea-froth. According to the prevailing mode of changing old names and making new ones, Fabbroni calls the above earth Farina foffilis, under which is underftood, at prefent, an earth arifing from efforefced oypfum. {For Fabbroni’s method of pais ae bricks, fee The P! bilofoph:cat apr rag Vol, He p.iS0, Epon fiane ; — amt eet oe a Eighth Communication from Dr. Thornton. 419 “Rone; for example, Cornelius Severus, the author of a poeti- cal defcription of that mountain, Theophraftus {peaks alfo of the pumice-ftone of tna, which he deferibes as black and’ hea*y *. Under this head we may place the Catinenjfis pumex of Juvenalt, though this phrafe will admit of an- other explanation; and perhaps the poet meant only to in- dulge in a little occafional raillery againft the celebrated vo- luptuaries of Catina or Catana. I well know that we cannot expeét from poets, in general, the accuracy which mutt be ebferved by naturalifts; but thofe who confider the paflage as admitting of no doubt, may fupport it by the teftimony ef Gioeni t, who found pumice-ftone, perfectly like that of Lipari, in the neighbourhood of Aitna, during the eruption of 1787; but he adds, that nothing of the kind had ever been found near tna before. XX. Eighth Communication from Dr. THORNTON, Phyfician to the General Dif, enfary, relative to Pneumatic Medicine. @ASE OF PARALYSIS CURED BY THE INHALATION OF VITAL AIR. Mr. HUITSON,, who diffeéts for Mr. Cruickfhank and Mr. Wilfon, eminent teachers in the fchool of the late Dr. Hunter, had a paralytic affection of the right hand, which deprived him of its motion, and it felt to the other hand ai- * See the faulty G@man tranflation of his work on ftones, § 40. p. 120. I fail here occafionally obferve, for the fake of thofe who are fond of com- paring the accounts of the ancients and moderns, that a kind of tra/s was -employed for mill-ftones im the time of Theophraftus and Strabo, E:r# arty rata preras riGos-aualig. Strabo, Lib, VI. p.413- The ancients were acquainted alfo with the ule of that kind called by Cronftedt the Rhenifla mill-ftone; a good defcription of which has been given by Collini in Jom- nal d'un Voyage, Manheim 1776.8. p. 301. Compare allo my Piyfikalifit- Ovkon. Bibliob. Vol. VAI. p. 455 and 519. + Sat. VLIIL 16. 4 See Von Salt's CilleBions towards a Natural Hflory of the Kingdom of the Tw Sicilies, 1799.8. 1. p. 172. ways 430 Eighth Communtcation from Dr. Thornton. ways remarkably cold. The paralyfis feemed chiefly feated in the mufcle of the thumb. I advifed him the trial of electricity ; and we obferved, as well as thofe who accompa- nied him, that the electric fpark did not fly with a crackling noife to the paralytic mufcles. Trying a piece of dead meat we found the fame phenomenon. We then had recourfe to iwhalation of vital air mixed with atmofpheric, and he in- haled from fix to eight quarts vital air. The mufcle, now receiving oxygenated blood, afterwards caught the electric fpark very readily, and a genial warmth was diffufed throughout the paralytic hand. This was not a folitary ob- fervation, but conftant ; and it feems to me very forcibly to prove the animating principle derived from the oxygen of the air to the mufcular fibre; a principle not, as reprefented by Mayow, the moft fubtle, fpiritual, and ztherial, but one that can be made obvious to our fenfes in the form of air, adhering to the calces of metals, and capable now of being conceived even by the moft grofs underftandings. The patient, I am happy to add, by this combination of ex- ternal and internal ftimulants, was completely reftored, and has continued many months perfectly well. As the cafe is fhort, I will fay a few words on the combi- nation of remedies. The Faculty, and others, are always cry- ing out for the trials of the airs c/one, and forget that in their own practice they employ a variety of means. Thus, al- though exercife is recommended, is the ftomach neglected to be braced and ftimulated ? ey “The following cafe from John Hunter * is very illuftrative of this pofition : | 4 < A lady, of what is called a nervo@s conftitution, arifing in fome degree from an irritable tomach, often troubled with flatulencies, and what are called nervous head-achs, with pale urine »t thofe times, uncomfortable feelings and often finkings, had a tumor removed from the breaft, and likewife near the arm-pit: nothing appeared uncommon fer a few * Vide Kuster on the Blood, p. 412. : 9 days, ae Ses > ee es SP ete a a “ad Intelligence, and Mifcellaneous Articles. 43a days, when very confiderable diforders came on. She was attacked with a fhivering, or cold fit, attended with the feel vf dying, and followed with cold fweats. It being fuppofed fhe was dying, brandy was thrown in, which foon brought on a warmth, and fhe was relieved. The fits came on fre- quently for feveral days, which were alfo relieved by brandy; and fhe took, in one of the moft violent, half a pint of bran- dy. While under thefe affeGtions, the had the bark as a ftrengthener; the mufk occafionally, as a fedative, in pretty large quantities; camphorated jalap frequently, as an anti- {palmodic; and, towards the laft, fhe took the valerian in large quantities: but whatever effeéts thefe might have in leffening the difeafe, on the whole they were certainly not equal to it without the brandy.” John Hunter judicioufly adds: “A queftion naturally occurs: Would the brandy alone, if it had been continued as a medicine, have cured her without the aid of the other me- dicines? The other medicines, I think, certainly could not have done it; nor do I believe that the brandy could have been continued in fuch quantity as to have prevented their returns: if fo, then the two modes were happily united, the one gradually to prevent, the other to remove immediately the fits when they came on.” ee = = = = = = INTELLIGENCE, AND MISCELLANEOUS ARTICLES, LEARNED SOCIETIES. AMERICAN PHILOSOPHICAL SOCIETY, HIs Society has recently publithed the following cir~ eular letter: “ The American Philofophical Society have always con- fidered 432 Learned Societié. fidered the antiquity, changes, and the prefent ftate of their own country as primary objects of their refearch ; and, with a view to facilitate fuch difcoveries, a permanent committee has been efiabhithed, among whofe duties the ioilowing have been recommended as requiring particular attention : ‘© +, To procure one or more entire fkeletons of the Mam- moth, fo called, and of fuch other unknown animals as either have been, or hereafter may be difcovered in America. “¢ 2. To obtain accurate plans, drawings, and defcriptions of whatever is interefting (where the originals cannot be bad); and efpecially of ancient fortifications, tumuli, and ether Indian works of art: afcertaining the materials com- pofing them, their contents, the purpofes for which they were probably defigned, &c. <¢ 3, To invite refearches into the natural hiftory of the earth, the changes it has undergone as to mountains, lakes, rivers, prairies, &c. << 4, To inquire into the cuftoms, manners, languages, and character of the Indian nations ancient and modern, and their migrations. << The importance of thefe objects will be acknowledged by every lover of fcience, and, we truft, fufficiently apologife for thus troubling you; for without the aid of gentlemen who have tafle and opportunity for fuch refearches, our means would be very confined. We therefore folicit your communications, now or in future, on thefe fubjeéts ; which will be at al! times thankfully received, and duly noticed in the publications of the Society. << As to the firft object, the committee fuggeft, to gentle- men who may be in the way of inquiries of that kind, that the Great Bone Lick on the Ohio, and other places where there may be mineral falt, are the moft eligible {pots for the purpofe, becaufe animals are known to refort to fuch places. << With refpect to the fecond head, the committee are de- firous that cuts in various directions may be made into many ef the tumuli, to afcertain their contents, while the diameter of | a eee Learned Societies. 433 of the largeft tree growing thereon, the number of its annu- lars, and the fpecies of the tree, may tend to give fome idea of their antiquity. If the works fhould be found to be of mafonry; the length, breadth, and height of the walls ought to be carefully meafured, the form and nature of the ftones defcribed, and fpecimens of both the cement and ftones fent to the committee. * The beft methods of obtaining information on the other fabjects will naturally fuggeit themfelves to you, and we rely on a difpofition favourable to our withes. *¢ The Committee confift of the following gentlemen, viz. Thomas Jefferfon, Prefident of the American Philofophical Society, at Monticello in Virginia. James Wilkinfon, Commander of the Army, at Head Quare ters. George Turner, of the Weftern Territory, near Cinginnati. Dr, Cafpar Wiftar, Vice-Pref. of the A.P.S. Dr. Adam Seybert, Secretary of ditto. C. W. Peale, and Jon. Williams, ¢¢ Your communications may be addreffed to any one of the Committee; but the articles you may think proper to furnifh, fhould be fent to this place. In behalf of the Committee, I am, refpectfully, Sir, your obedient fervant, J. WitiiaMs, Chairman,” in Philadelphia. At the meeting of this Society, January 10, 1799, among other donations and communieations, the following were announced as having been received ; A communication from Mr, Andrew E]licot, determining the latitude and longitude of the town of Natchez—A letter from Dr. Prieftley on the decompofition of water—Three barrels, containing the bones of non-defcript animals, and two meteorological journals kept at Detroit and on a voyage to Michilimacanac on the Lakes, by Gen, Wilkinfon—A fpecimen of mica from New Hampthire—Experiments and Vou. IV, Ff obferva~ 434 Entomology.—Fire-Ball.—Comet. obfervations om the atmofphere and marfhes, by Dr. Sey-” bert—And a paper concerning the pernicious effects*of the Equizetum byemale, or rough horfe- tail, when eaten by pti < by Mr. Barton. 4 ‘MISCELLANEOUS. Sah AMERICAN ENTOMOLOGY. With pleafure we atimounce to naturalifts Mr. Baker’s colleétion of American infects. In his mufeum at New- York may be feen about three thoufand fpecies, principally arranged according to the Linnean fyftem. They were col- jected chiefly by Mr, Jotham Fenton, who has been nearly fix years engaged in entomological purfuits. The fpecies of this collection were moftly caught in the neighbourhood of the cities of New-York and New-Haven, . FIRE-BALL. A very remarkable phenomenon of this kind was feen in. the county of Kent, and the neighbourhood, on Sunday the 22d September, at about 35 minutes paft eight in the even- ing. It came from the fouth-weft, and pafled in a fouth-eaft - direétion till it funk in the horizon.. It feemed to be nearly of the fize of the moon, but of an oval form, or rather in the form of an ox’s bladder, the thickeft end going foremoft. The fky, which was dark and ftormy, was illuminated during its paflage more brightly than by the full moon. _ Its colour was a vivid white, inclining a little to yellow; and it feemed as if followed by a few fmaller globules, or rather large fparks of a red colour, which kept at the fame diflance from its body during the whole time that it was vifible, which was for feveral feconds. ASTRONOMY. A comet is now vifible in our hemifphere. It was firft feen on the 6th inft. near the lower fide of the quadrangle of Ur fa Major, from which it has been moving about 3° in 24 hours, following the direétion of the tail, and throu one fhoulder of Bootes, INDEX [ 435 ] INDEX ro VOL. IV. ACETAT of copper, method of manufaCturing, page 171. Acetite of copper, on tbe manufacturing of, 71. Acid, tung fic, experiments on vegetable colours with, Sa. Acouffic experiments by Chiadni, 111. —_———-- by Prieitley, 283. . by Perolle, 284. by Voigt, 347. Alercfiation, improvement in, 107, , Agenda for forming a theory of the earth, 63, 188, 259, 351. American Philofophical Socicty, circular letter by, 431. Ammonia, a cure for the bite of fnakes, 192. Animalcules, account of fome, 397- Animal clediricity, obfervations on, 59, 163, 332- Animals, on mutilations becoming hereditary in, 1, Apparatus for the combuftion of phofphorus in oxygen gas, 83. Apparatus for meafuring the heat in furnaces, 255. Arania obletrix, defcription of the, 121 Afia and Europe, query refpeéting the boundaries of, 327. Ajay furnace, defcription of Mr. Mufhet’s, 255. Afironomy, Lalande’s hiftory of, for 1798, 23.—A comet, 434. Bacftrom’s voyage to Spitfbergen, 139. Balloons, plan for navigating, 107. Banian tree, account of a, 360. Barometer, defcription of Humbolt’s portalle, 3046 Bechfiein on the origin of the goffamer, 119. Beckman’s obfervations on’ pumice-{tone, 423. Beet-root, on the manufacture of fugar from, 218, 334. Bindhcim on the different kinds of Cadmia, 250, 362. Biographical memoirs of De Saussure, 96. of Charles Theodore, elector palatine, 1116 of Revely the architect, 220, of Borda the aftronomer, 223. Black paint, difcovery of a new balis for, 334. Blue, method of preparing turnfol, 17. Blumenbach on the hereditary effects of mutilations; 1. Bolides or fire-balls, one feen im Kent, 434. Borda (the altronomer), biographical, memoirs of, 223+ Bourbon, geographical selgeipaign of 2040 : 2 Brown's 426 INDEX. Brown's travels through Egypt, Syria, &c. 239, 405. Bruguiere and Olivicr’s travels through Turkey, Egypt, &c. 66 Brunfwick green, preparation of, 215. Bugs found in hollow trees, 57. Cadmia, Bindheim on the different kinds of, 250, 362. Calcareous fubjtances the healthieft for buildings, 233. Camel, propolal to introduce at the Cape of Good Hope, 333+ Candles, to prepare with wooden wicks, 79. Cats, on an epidemical difeafe among, 297. Cement for cracks and fiffures in iron veffels, 216. Chaptal on the manufaCture of verdigrife, 71. Chaptal on the manufaéture of acetat of copper, 172+ Children apparently born dead, not always fo, 211. Chladni’s acouftic experiments, &c. 133, 275+ Chladni on animal ele€tricity, 332. ‘Cobalt, Bindheim on the ores of, 362. Jomet vifible in September 1799, 434+ Cotton, to know when adulterated with wool, 217. Cow-pox, communication from Dr. Pearfon on the, 342. Crayons, on the preparation of, 299, Danzel’s plan for navigating balloons, 107. for navigating fhips in a calm, 109. Dayes’ remarks on Mr. Sheldrake’s differtation on painting, 124, Day’s arrangement of the cryftals of oxydated tin ore, 152. Deafne/s, thoughts on, with helps for, 117, 378» Deaths, 111, 220, 335. Difcharging elvGrometer, an improved, 267. Difeafes cured by inhaling gafes, 95, 201, 329. Earth, agenda for forming a theory of the, 68 ; Larih, mountains of the, compared with thofe of the Moon and Venus,. 393. 4 Lau de Luce, a cure for the bite of fnakes, 191. Egypt, travels through, 6, 239, 405. Llkeéérometer, defcription of an improved difcharging, 267. Elephant, anecdote refpecting a female, 330. Entomology, American, 4:34. Epidemical difecafe; account of one among cats, 297. Eudiometer, account of Gren’s, 216. Exrope and Afia, query refpecting the boundaries between, 32°7. Fiery eruption feen at the Peak of Teneriff, 219. Fire-ball {een in Kent, 434. Fog, obfervations on that of 1783, 417. ox, fome particulars concerning the rock or ice, 402. Galvanifm, obfervations and experiments on, 59, 163, 332. Cafes,” of the tones produced by an organ-pipe in different, 275. “ayes, cures by inhalation of, 95, 293, 329 Geography, INDEX, 43% Geography, a query refpeGting, 327. Glazing of earthen veffels, without lead, 203. Gold, on the apparent converfion of filver into, 18. Gold found in vegetables, 197. Goffamer, on the true origin of the, 119- Gower on the form of vanes of windmills, 174. Green, preparation of Brunfwick, 215. Greenland, Dr. Bacttrom’s voyage to, 139+ Gren on animal eleCiricity, 163. Gren, account of the eudiometer invented by, 216. Guyton’s experiments on the colouring matter of vegetables with the tungttic acid, 81. Haffenfratz on the oxygenation of fnow and rain, 217. Hauch (Von), improved difcharging eleGtrometer by, 267. Hildebrant on the apparent converfion of filver into gold, 18. Howard’s (Mr. Edward) fulminating oxyde of mercury, 213. Human flefh, on the inducements to the eating of, 265. Humbolt’s portable barometzr, defcription of, 304. Hydro-azote, method of preparing, 96. . Hydrogene gas, effe& of, on the voice, 2146 Ice fox, fome particulars concerning, 402. Inoculation of sheep, prize queftion refpecting, 104. , remarks on, III. Inoculation for ihe cow-pox, Dr. Pearfon’s ftatement of the progrefs made in, 312. Infeés, American colleCtion of, 434. Inftitute of Cairo, proceeding of the, 104, fron found in vegetables, 196, 198. fron, on the manufacturing of, 43. Iron ores, on the aflaying of, 178, 381. Lronfide’s account of two fingular trees, 359, 360. fron veffels, a cement for, 216. Lfles of France and Bourbon, geographical defcription of, 204. Kirwan, new works by, 329. Lalande’s hiftory of aftronomy for 1798, 23. Lalande on the cold of laft winter, 110. on the tranfit of Mercury, 215. Larva of infeds expelled from the human ftomach, 366. Larwick in Shetland, thort account of, 141. Learned Sogieties, intelligence refpecting, 103, 207, 329, 431%» Lions, anecdotes of two, 212. Lifoon, account of the conftruétion of the city of, 234. Lomet’s procefs for making crayons, 299. Loureiro on the eating of human fleth, 265. Manganefe found in vegetables, 197. Mann on the caufe of changes of temperature, 337. P Marum, . * ass ' END Ex. .. Marum, Van, apparatus for the combuftion of phofphorus by, 83. Medicus on candles with wooden wicks, 79. Mercury/ effects of on vegetable life, 161. » anew fulminating preparalign of, 213. - Mlercury, Lalande’s note on the tranfit of, 215, Meteorological remarks, 110, 417+ Peteorological changes indicated by animals, 367+ Meteorology, aphorifms connected with, 333. Metre, on the length of the French, 215. Midwifery, important difcovery in, 21]. Mitchill on the healthicft materials for buildings, &c. 233+ Mitchiilian theory, developement of the, 35, 132. Afoon, on the height of mountains in the, 393. Mountains, comparative height of, in: the Earth, Moon, and Ve- nus, 303- PGufhet on the manufacturing of ixony 43° Bufbet's aflay -furnace and pyrometer, 255. Mu/het on the affaying of oves by fufign,. 178, 380, Blifical frings, on the vibration nodes of, 347. Mutilations produce hereditary marks of diftinction, 1. Navigation, an improvement in, t09- Odhelius’s account of larve of infeéts expelled from the human ftomach, 366. ~ . ‘Ocdman on bugs found in hollow trees, 57- O:l, on calming the waves of the fea by, 225. Oil, effeéts of in curing the bite of ferpents, 275+ : Olivier and Bruguieré’s travels through Turkey, Egypt, &e, ie Ozio on the property of oil in calming the fea, 225. Ottoman empire, travels through the, 6. Oyes, on the aflaying of by fufion, 380. 4 Padua, meteorological obfervations made at, 417« Paint, difeovery of a new bafis for Black, 334s Paiating, remaiks on Mr, Sheldrake’s difflertation on, 124. Palatine (the Ele&or), death of, 11 '. Paralyfis cured opie iwhalation of vital air, 329. Peak of Tester‘, an eruption feen at the, 219. Pearfon’ s ftatement of the progrefs in vaccine inoculation, 352. Perfia, Egypt, &c. travels through, 6, 239, 495. Pepitential, fi ds, developement of Dr, Mitchill’s theory of, 355 332» Phenomena, epochs of various meteorological, 420 Phofphorus, apparatus for the combuttion of, 83. Pri ymatic Medicine, communications refpeGing, 95> 201, 329- Potatoes, ize made from, 335. Pouncy (the engraver), death of, 335. Powder-proo/, defeription of Regnier’s, 394. Privies, to prevent the difagreeable fmell of, 214. Prize hee by the Society of Agricuiture at Copenhagen, 1033 — , by the Royal Society of Gottingen, 104, j £ uilicalonee 4 Pablications, account of new, 207, 329. Pulmonary difeafe, a cafe of, cured by hydro-azote, 95. Pumice fione, obfervations on, 423. Putrid fever cured by inhaling oxygen gas, 201+ Pyrometer, de{cription of Mr. Muthet’s, 255. Rain-water, on the oxygenation of, 217." Reevely {the architect), death. of; 220. Regnier’s powder-proof, delcription of, 394. Rock or ice fox, fome particulars coucerning the, 402, Reds, on the longitudinal vibrations of, 113. Royal Society of London, proceedings of the, 107, 209. Royal Academy of Sciences at, Lifbon, tranfactions of thé, 207. Royal Society of Gottingen, traniactions of the, 207, Royen (Profeflor at Leyden), death of, 335. Sauffure’s Agenda, 68; 188, 259; 351. - Sauffure, biographical memoirs of, 96. ' Schroeter, on the mountains of the Earth, Moon, and Venus, 393. Sea, remarks on the.colour of the, 142. Sea, to calm by means of oil, 225. Serpents, oil a cure for the bite of, 375. Sheldrake, remarks on his differtation on painting, 124. _ Shipwrecks, means for faving the crews from, 247. Silver, on the apparent converfion of into gold, 18. Size, a ufeful owe from potatoes, 335. Smyth (Dr.), on Mr. Cruickthank’s communication in Vol. IIE. | £03. Snakes, to cure the bite of, 191. Suow, on the oxygenation of; 217. Soil, enquiry into the caufe of changes in, 337. Sound, on the conveyance of through folid bedies, 113. Spitfbergen, account of a voyage to, 139. ———., Roffian fettlement at, 146. Still-born children may fometimes be revived, 211. Strawberries, native iron found in, 193. Strings, on the longitudinal vibrations of, 113. Strom’s account of fome animalcules, 397. ' Submarine foreff, account of a, 287. : Sugar, on the manufacture of in Europe, 218, 334. Swallows, on the difappearance of in autumn, 4:4. Syria, travels through, 405. - % es oO a Tafte afleXed by galvanifn, 169. . Telefcopes, method of determining the magnifying power of, $7 Tenp-rature of climates, gradual changes in the, 337. Tcneriff, an eruption feen at the Peak of, 219. Theory of the earth, hints for a, 188, 259, 351. Thornton on pneumatic medicine, 95, 201, 329. Timber, prize quettion on the rearing of, 103. _Tia ore, attempt to arrange the cryltals of, 152. : : Yoaldo 440 INDEX. Toaldo on figns of change of weather, 3676 on the fog of 1783, &c. 417. Tornado, a phenomenon of this kind in Berwickhhire, 219, Tranfiutation of metals, remarks upon, 18. Travels through Turkey, Egypt, Syria, &c, 6, 239, 495. Free, account of a large one, 259. Turnfol blue, method of preparing, 17. Uranite, query refpecting the analyfig of, 112. Vaccine inoculation, communication from Dr. Pearfon on, 312, Variolous matter, \etter from Dr. J. C. Smyth on, 103. Varley on the magnifying power of telefcopes, 87. Vegetable life, effects of mercury on, 161. Vegetable juices, experiments on the colouring matter of, 81. Fenus, on the height of the mountains of, 393. Verdigrife cryfalized, method of manufatturing, 171. Verdigrife, on the manufacture of, 71. Foigt on the vibration nodes of mufical ftrings, 347. Vclatile alkali, a cure for the bite of fnakes, 192. Volta, polt{cript to his letter on galvanifm, 306, on animal electricity, 59. War, the influence of on the atmofphere, &c. 333. Weather, on figns which indicate changes of, 367. White-wa/bing, a new fize for the purpofe of, 33 5- +/byte’s thoughts on deafnefs, and help for, 378, Williams on the cure of perfons bitten by {nakes, 191- » Windmills, on the form of the vanes of, 174. Wood, an experiment on the growth of, 197. Wool, to know when adulterated with cotton, 217, Zink, Bindheim on the ores of, 2516 END OF THE FOURTH, VOLUME, LONDON: PRINTED BY J. DAVIS, CHANCERY-LANE, _M.DCC.XCAX, Philo. Mag Pili Vol HH. Philo Mag PLL Vol HM. 4 Sj ( 7 a A aN z co fs ‘e: 2a.30 Rise owe Philo.Mag Pi] Vel IM =— ZZ pQ ~ 5) fs ] TATA AANA Phil Mag PLULVOLIV- a | | cy ri + a ay : i = : Bh * ‘Ss mt “ni | f St S Ss ‘ SS 4 Ae Bg bs S ., Z S L2 ; S SS = t f SS a5 = B= Ba b ae 7 ; rie SS 5 ioe = = Ss ws 9 eel Ma Le FL, IV if z a " gg il _ eH i | yt! l i} rH H) i I iN} = _ — 2 —<—=— i j = Bon | ¥ 1 . ’ > j + ~ \ . - ‘ < ° . Oa . ‘ * o™ ¢ . an 2 1~) a =o Lal =e D — | ks if SSS SSS SSS SSS SSS Llc SSS A W/Z, Wik iL eae } Z — i G y ¢ (a Oe O=SL—S-—-—_E=SSSSS== BO ZB UW AT LU TA td OD RY A Th cease Fig. 2. Philo Mag. Ll VIL. Vol Te TT Lewy, feu ‘ aa Philo. Mag Pl VITVelL V. < sh g & Rie “S Se P| £ L i allt ih) i ‘ 20000 aS = = > & = 5 : eS K\ <8 3 2 “~S S RF AY a S S = \.' $ os ty ~~ ih ~ N K\ ‘ie S p 175 000 Fathoms. 10000 Sooo Philo. Mag Pt VIM Vol It BARTH Moon VENUS eg ere aes S 8 5 S My Rp gs SS g 8 S g 3 8 8 8 > x 8 & ee AS) Re 3} Se S = $ zs = 8 S 5 y 3 8 9 x 8 § iS S| S000 i Lowry sculp. VENTS Philo Mag. Pl IX Vol. IV. so paenarines. 0 ea fates Wen tay <2 ee} ry Gea i eh hee at ee Salmon, . of Woburn, Bedfordthire, for which a | d to him by the Society for the Encouragement ‘Machine invented and employed by the to make his* vo rivalled Vegetable Cuttings for |. Vs syd (worn the Machine itfel now 98 f the Cryital ind a F i 5a gat uation of the Vanes Windmills as far asconcerns athe 4 ae Hee? YS ri SAP Nn aa > c Cay: > INTENTS of NUMBER BV 0 ty afcribed to Oil, of calming ial la 4 7 sy rae Be 233. Ay aie ‘the Utili Sea bk Votes tibia ts vse us Author ay 2 244 ete : ‘te ; mof Mofcow, - © 259 ae ‘aed Ks hs CR SN AN n of Obfervations and Re- » oy ie: tera ich may ferve asthe Foundation By M. Dg Saussure . : ae oe oer 7 Ui the Tones of the Academy of Turns, peu TERN ST t) Ee ts se Le aa oe : rp > seth at FON od Pr ». eg Mag Jo: et oa pe 8: On an sate SBe i ti PEPER. ary *7 Br, Whyte’s Favd Mew: Bodke, “tions; poft-paid, G oiaecinss Bet - : mber, but fh , “e * . < a oe oe a a ee ee ee eee ENGRAVINGS. » Machine for drawing: Bolts in and out of Ships—Cit, Guyton’s oe Ds GeacielBader’ the improved Machine for Cutting Chaff, invented | wt ‘by Mr. Robert Salmon, ‘of Nation peg Bedfordthire, Yor which ¢4 . mines Bounty was voted to him by the Society for the Encouragement ets of Arts, &e— The new. Machiné invented and'employed by the -- “+ Tate: Mr. Cufance to make his’ unrivalled Vegetable Cuttings for a: the Microfcope ; ; drawn and engraved from the Machine i iefelt, FROWN ae ‘the pofleffion of Dr. Thornton; a,Plate to explainthe Method fotming Figures. with’ Sand on Vibrating Surfaces, according r. ~ Chiadni’ ’s Theory—The Furnace eniployed by the French ils in their Examination of C. Clouet’s Procefs forthe im- ' © ¢ adiate Converfion of Iron into Caft Steel by means of Carbonat =, | att “Lime , and the New. Steel- Yard invented by c: Paul of Geneva, Fo BR KLILAS neg with a, Plate of Fipives ‘tow xplain so a ry of ke ones chen ha oad oa hale Dr. Van - ie be Com e. ‘Mltrated ney: a. eat" "Plate Aadiioet te. the 640 K tals of ‘Oxyde of Tin—and a Plate lluitrating A NRE YAN 9 en n-of the Vanes of ie aa as far ay coneerns eS aoe tat ather, i Nes mber XV isitlafirated ‘pith Plate. oe Mr. Sines pris. hin sa a oy afcertaining the Heat ofan Aflay-furnace—Von Hauch’s ye Nol Jifcharging Eleétrometer, laid before the Royal Society ot a Soper agel—and, as gue Portable vighen soos for Travellers, Ps) 2 , ia i y ab ‘ . ae Ry vs ee | the re vidiel ge is RD A ane Soil ad “f vow ie Mt lace i. different limates, 1 ‘with an’ Enquiry i in Oo Yet AN erg cual thofe Change . By the ‘Abbé Mann Sas ae 337 shea lS oan J. Obfervations on the \ ‘ibration Nodes of Mafical Siriagess IEW & Jie J. G. Voicr of Halle + is 347 pes Be. Agenda, or a Colleétion of Obfervatibns. ‘phd Ree ‘ ” fearchies, the Refults: of which may ferve as the Foundation aA ey teen. Theory of the Earth. By M. pz Saussure aes vo veany og ; aise ofa eRe: ‘Tree in pny ia. ae Colonel Inow- ae is $89: 1 - ae, re a “Banian Tree in ‘the Province of Bahar. ; f sg cape ee tf aH Jha so! fagtie h € ds rer ‘Gudinia, ‘iad pacculaly iyi a 11, Saget ry sce heat ‘onan, eff vik . the Latver tein sage sy ‘ns ¢ > eg oO ‘ By M. ToaLvo— | Yon of Juné 1783, with a Differtation on the extraordinary ” VILE: On the CaS exhibited ae Sims eliich ile ii. ~ Changes. of the Weather, saa? Rema ks. A other, Proguofti a “Gazette. PO ee oy ya ee ts * iDialacke Spike a new Mode of 1 S } YQ ne Sie, BON : ete . XI. On the Aflayin GE oie by Fee By Mt. Davi “Mu SHET of the Clyde’ Tron Works. “Communicated ; Author 6 9) Sepa kes Sh Erich. 380° Xil. On the Comparative Height « of ‘the Mountains of the Ear th, the Moon, and Venus ~ 393 (oh a "KIL #-Defcription. aid Ufe of'a new 5 Pobeable Tnftrument ~ a - for -afcertaiming the: ‘Comparative ‘Strengeh of ca at se By C. ReGuier ee XIV. Accourtt oka’ Red Sibitance’ biesen: on 1 the Surface of a Fifh-Pond in Norway “By Profelfor J te Sram soe 1a ay gh Obfervations on ee Apgeler Sagacity of the Rock or < ‘Ace Moxy "Fr ys UKVA." An Revonny of ‘Mr. Brows’ Travels. thre agh ” Egypt and Syria, &c. ie co Case 4 XVII. On the TT iegieataacs Re Swidiows” in. Autumn; Ap Ki jn-a Letter from Mr. Perer Coreto Dr. Mrremitt,. dated _ - New-York, September. 25, 1798. Seo Le “SVIOL “Meteorologica Obfervations Ealle at ‘Padua: an the | _ Fog which prevailed about that time. By M. Toarpo +. an rs XIX. Obfervations on Pumice-Stone; and the: ae where ; “foand. By Profeffor BECKMANN | 2 ae ~ or . Eighth Communication from Dr. Th *HORNTON, Gore : figian to, the General Soni ctt relative! ° Pneumatte Mes v ?’ ey ie BY : ee piscine yar patente iat he Farther, fie ces be: known by applyi Bigies beat No.4, Be iae Peden aT KOBE ines may Ne ML Nh " ¢ i Sein