peseeee rari test et Sipe eee er Pee deebrer IF ists * rtet h iw i i ii be It tes =! tse rtcs stesccosss tabeed aEprenssesapesed voretetossenitts lapsteneset peony Hatt tt r oeoetes The Sie sitesite peeenee? sett bad hlasctor: age eset sO) +3 Siete tity Ht CUS Ht + 3! sos « ne penis Bite ep siet roresenyey eee rH Teh rect et 4 +3t +: shee be teete? oii hea +t saait + r + pesteereey ey eget bette! serthe h ; i i pees + pees etit <4 aeeterer. press wt seitt petes) eres’ pepeereieise: pilin ts ere esatess tittle ret agit eeerree tt pt pees + eipieces cee! Tite f + tf st sottt stat Leytiteet ees rposecd arse sbetarpietert bea ae : i * re sities itt Ht He ey}! & ine. -JOURNAL NATURAL PHILOSOPHY, -. CHEMISTRY, - AND ~ THE A eT S- VOL. XXX. Bee -. Silustraten with Engravings. RS BY WILLIAM NICHOLSON. - LONDON: - PRINTED BY W. STRATFORD, CROWN COURT, TEMPLE BAR ; FOR W. NICHOLSON, No. 15, BLOOMSBURY SQUARE; : AND SOLD’ BY J. STRATFORD, No. 112, Hotzoxn Hitt, 1812.» ~ PREFACE. HE Authors of Original Papers and Communicatiofis in the present Volume are Mrs. Agnes Ibbetson; W. H. B.; Mr. John Davy; Mr, Grover Kemp; Thomas, Forster, E’sq.; Luke Howard, Esq.; Dr. Delaroche; W. Moore, Esq.; H. T..B.; Adam | Anderson, Esq.; Marshall Hall, Esq.; Mathematicus; Mr. Charles . Sylvester; Thomas Stewart Trail], M.D.; Mr. Joho Murray; . Richard Lovell Edgeworth, Esq. F. R. S. M. R. I. A. &c.; John Farey, senr. Esq.;- Nauticus; and Mr. John Gough, _ Of Foreign Works, M. Berthollet; M. Gay-Lussac; M.'Thenard ; M. Vauguelin; M. Malus; M. Biot; Mr. J. Cloud; M. d’Arcet ; M. Decandolle; M. Vitalis; M. Haiiy; Prof. Pictet; Prof.. P. Prevost; Count deFourcroy; M. Berzelius; M.Guyton-Morveau ; M. Klaproth; M. A. Laugier; M. Chevreul; M.Bucholz; and M. Martres. And of British Memoirs abridged or extracted, George Pearson, M.D. F.R.S.; Luke Howard, Esq.; the Rev. John Simpson; the Right Hon. Sir Joseph Banks, Bart. K. B. P.R,S. &c.3.Mr. - Bryan Donkin; Mr. J. D. Ross; Mr. George Marshall; James Smithson, Esq. F. R.S.; Mr. Richard Cathery; Everard Home, Esq. F. R.S.; Thomas Andrew Knight, Esq. F. R. S. &c.; Mr, J. Hassel; Mr. William Corston; Dr. William Roxburgh; David Brewster, LL. D. F. R.S. Ed.; B. C. Brodie, Esq. F. R.S.; Mr. William Lester; Mr. William Salisbury; and Mr. Samuel Roberts, The Engravings consist of 1 and 2. Various Figures representing the Hairs and minute Cryptogamie on Plants, greatly magnified and delineated from Nature, by Mrs. A. Ibbetson. 3. Mr. Donkin’s Tachometer, for ascertaining the Velocity of Machinery. 4.A | Hippograph, or Mode of conveying Intelligence by Cavalry. 5 — Mr. Ross’s Machine for separating Iron Filings from those of other Metals. 6. Mr. Marsliall’s Sash-frame for preventing Accidents. 1. Peduncles of Leaves delineated and dissected, to show their Mechanism, by Mrs. Agnes Ibbetson. 8. Apparatus to explain the Decomposition of Water in separate Vessels by Galvanism, by Adam Anderson, Esq. 9. Crystals of carbonated Lime, by Abbé Haiiy. 10. Plans and Sections of a Spire of a new Con- struction, lately erected at Edgeworthstown, by R. L. Edgeworth, Esq. F. R.S. M.R.1.A., &c. 11. Diagrams for the Demonstra- tion of the Fundamental Property of the Lever, by D. R. Brewster, LL. D. F. R.S. Ed. 12. Mr. Lester’s Machine for washing Roots: 13. Mr. Salisbury’s Method of packing and preserving Plants and Trees. 14. The Sheffield Apparatus for cleaning Chimneys with- , out the Aid of Climbing Boys. . . TABLE (*) TABLE OF CONTENTS’ TO THIS THIRTIETH VOLUME, SEPTEMBER, 1811. Engravings of the following Subjects: Various Figures, in two 8vo Plates, representing the Hairs and minute Cryptogamiz on Plants, greatly magnified, and delineated from Nature, by Mrs. AlIbbetson. I. On the Hairs of Plants. Ina Letter from Mrs. Agnes Ibbetson I II. Inquiry concerning the Natural Economy of Ants. In a Letter from a Correspondent - sot - : ae - 10 Ili. Report of a Committee, consisting of Messrs. Berthollet, Chaptal, Vau- quelin, Le Breton, Vincent, and Guyton-Morveau, appointed by the Institute to inquire concerning the Process of the late Mr. Bachelier, for the Com- position of a preservative Stucco - ee SE IV. Obsérvatidts and Experiments on Pus. By George Pearson, M. D. : PVRs: - > - - ~ ae tee 17 V. An Account of a New Gas, with a Reply to Mr, Murvay’s last Observations |. on Oximuriatic Gas: by Mr. John Davy - = = 28 VI. Method of preparing a beautiful and permanent White for Water Colours. ‘In a Letter from Mr. Grover Kemp - - - 33 VIL. The Natural History of Clouds. By Luke Howard, Esq. i i bt. VIII. An Account of the Thunder-storms on the 19th of August: In a Letter from Thomas Forster, Esq. - - - - Oe IX. Meteorological Journal - Q ° - 64. X. Abstract of a Memoir on the Analysis of Vegetable and Animal Substances: ~ by Messrs. Gay-Lussac and Thenard = Hig - 66. XI. Chemical Examination of a white filamentous Substance, found in the Cavities of the Cast Iron that adheres to the Sides of High Furnaces: by Mr. Vauquelin - - + - - 74 XI. An Account of the Burrknot Apple. Ina Letter to, Henry Grimston, Esq. F. H.S. By the Rev: John Simpson - ~ - lorat 76 XII. A short Account of a new Apple, called the Spring-Grove Codling. By the Right. Hon, Sir Joseph Banks, Party dh Bi Pi Re Sirde00.i W077 Scientific News = . . - oa 78 | OCTOBER, . - » IV. Meteorological Journal =. - PAK By. P. RS. &e.\/ \- “XVII. Method of preparing Ox Gall in a concentrated State for Painters, and CONTENTS. v OCTOBER, 1811. >Engravings of the following Subjects: 1. Mr. Donkin’s Tachometer, for as- certaining the Velocity of Machinery. 2. A Hippograph, or Mode of con-~ _, veying Intelligence by Cavalry. 3. Mr. Ross’s Machine for separating Iron Filings from those of other Metals. 4. Mr. Marshall’s Sash-frame for pre- venting Accidents. I. On the Destruction of an Enemy’s Fleet at Sea by Artillery: by W. Moore, Esq. of the Royal Military Academy, Woolwich - = «te IJ. Correction of an Errour in a former Paper on the Motion of Rockets. By ~ W. Moore, Esq. In a Letter from the Author - - 9S Til. On a Property of reflected Light: by Mr. Malus - 2. a5 IV. Experiments on the Transmission ‘of Sound through Solid Bodies, and through Air in very long Tubes: by Mr. Biot wi) - 103 V. Observations and Experiments on Pus. By George Pearson, M D. F. R. Sz 113 VI. Description of a Tachometer, or an Instrument to ascertain the Velocities of Machinery: by Mr. Bryan Donkin, of Fort Place, Bermondsey* 121 Vil. A Mode of conveying Intelligence from a-reconnoitring Party. Ina Letter from a Correspondent —- - - get iv 126 VII. Description of a Machine for separating Iron Filings from their Mixture with other Metals: by Mr. J. D. Ross, Prince’s Street, Soho - iQT 1X. A new Method of constructing Sash Windows, so as to be cleaned or re- "paired without the Necessity of any Person going on the outside of the ¢ House: by G. Marshall, No. 15, Cecil Court, St. Martin’s Lane 129 X. Observations on the peculiar Appearance of those Metcors commonly called Shooting Stars. Ina Letter from Thomas Forster, Esq. - 131 XI. On the Composition of Zeolite, by James Smithson, Esq. F. R.S. 193 XI. Extract from a Paper communicated to the American Philosophical Society _.on the Discovery of Palladium in a Native Alloy of Gold: by Mr. J. Cloud, * Director of the Chemical Processes at the Mint of the United States 137 “XIU. Analysis of the Cement of an antique Mosaic, found at Rome: by Mr. aAKCEt ~~ - - = his - - 140 = ies 142 XV. Remarks on the Inclination of the Stems of Plants‘towards the Light: -by Mr. Decandolle - rie Mh - - - - 144 XVI. On the F orcing-houses of the Romans, with a List of Fruits cultivated ‘by them, now in our Gardens, By the Right Hon. Sir Joseph Banks, Bart. ¥ é zs ae 147 for other Uses: by Richard Cathery, No. 14, Mead’s Row, Lambeth 154 XVI. Letter from Mr. Vitalis, Professor of Chemistry at Rouen, to Mr. ° ebrcle erate, on the Amalgam of Mercury and Silver, called Arbor lane - -- ‘eathe te ~ - 156 Scientific News . ° Fs melt ¢ - 157 : NOVEMBER, vi CONTENTS. NOVEMBER, 1811. Engravings of the following Subjects: 1. Peduncles of Leaves delineated and dissected, to show their Mechanism, | By Mrs. Agnes Ibbetson. 2. Appara- tus to explain. the Decomposition of Water in separate Vessels by Galvanism. — By Adam Anderson, Esq. 3. Crystals of carbonated Lime. By Abbé Haiiy. }. Ona Property of the repulsive Forces, that act on Light: by Mr. Malus. 161 If. Experiments on the Production of Sound in Vapour: By Mr. Biot. 169 TY. Experiments to prove, that Fluids pass directly from the Stomach to the Circulation of the Blood, and thence into the Cells of the Spleen, the Gall Bladder, and Urinary Bladder, without going through the Thoracic, Duct. By Everard Hoime,Esq. F. R.S. : 173 1V. Of the mechanical Powers in the Leaf Stalks of various Plants. Ina Letter’ from Mrs. Agnes Ibbetson’ .— - - > L é 179 V. On the Decomposition of Water in two or more separate Vessels. In a Letter from Adam Anderson, Esq. , - 3 - - 183 BA Description of several new Varieties of carbonated Lime: by Mr. Haity. 189 Wil. Extract of a Letter from Dr. Francis Delaroche to F. Berger, Esq. ; on Radiant Heat and other Subjects. Communicated by the Jatter Gentleman. + = = 192 VIII. On Chemical Attraction. / By Marshall Hall, Esq. = z 193 IX. On the Horticultural Management of the Sweet or Spanish Chestnut Tree. By the Right Hon. Sir Joseph Banks, Bart. K. B. &c. - - 202 X. On Potatoes. By Thomas Audrew Knight, Esq. F. R. S. &c. - . 204 XI. A remarkable analytical Anomaly respectfully submitted to the Considera+ tionof Mathematicians. By a Correspondent. ~ - 209 XI. On the Migration of Swallows: by Dr. Traill. Read before a Literary and Philosophical Society established at Derby, Sept. 17th, 1808, of which Dr. Traill is a corresponding Member - - - 213 XIlt. Account of the Appearance of a Luminous Meteor: by Professor mebirtet. 2a Be ae - 216. XIV. Letter from Professor P. Prevost, to Professor Pictet, on the Meteor of the 15th of May. - - - - 5 & ee ae 3 218 xv. Improvement in the Aquatinta Process, by which Pen, Pencil, and Chalk, Drawings can be imitated; by Mr. J. Hassell, No. 11, Clement’s-Inn. 220 XVI. On the Nature of Oximuriatic Acid Gas, and the Conversion of Car- bonic Oxide into Carbonic Acid by it, in Reply to Mr. J. Davy. In a Letter from Mr. J. Murray, Lecturer on Chemistry, Edinburgh. - 236 XVII. Meteorological Journal ‘ee - eb ae ae 226 XVIII. Experiments on the Acid Phosphate of Potash: by Mr. Vauquelin. 238 Scientific News. - - ~ | - 239 DECEMBER, \ CONTENTS. ee DECEMBER, 1811. Engravings of the following Subjects: 1. Plans and Sections of a Spire of a new _ Construction, lately erected at Edgeworthstown, by R. L. Edgeworth, Esq. _F.R.S. M.R.I. Ay &c. 2. Diagrams for the Demonstration of the Fun- damental Property of the Lever, by D.R. Brewster, LL.D, F.R.S. Esq. f. Description of a Spire of a new Construction, at Edgeworthstown, combining the Advantages of Cheapness, Elegance, and Durability. Ina Letter from Richard Lovell Edgeworth, Esq. F.R.S. M.R.L A. &c, - BAL nL Experiments on some Preparationsof Gold: by Mr. Vauguélin - 248 Ii. Experiments on Human Bones, as a Supplement to the Paper on the Bones of the Ox; by Messrs. Fourcroy and Vauquelin. Lanai So, my ee iV. Letter from Mr. Berzelius to Mr. Berthollet on the Analysis of different ~ §$alts. - - - - a 6A - - - - - 260 ¥V. Account of a Substitute for Leghorn Plait, for Hats, &c. By Mr. William Corston, of Ludgate Hill - - - , - - . - 273 Vi. Correspondence of Dr. William Roxburgh, of Calcutta, with Dr. C. Tay- lor, Secretary to the Society of Arts, 8cc. on various Drugs. = 276 VIL Demonstration of the Fundamental Property of the Lever, by David - Brewster, LL. D. F. R.S. Edinburgh. 280 VII. On the Nature of those Meteors, commonly called Shooting Stars. In. a Letter from John Farey, Sen. Esq. 4 - ~ =) “= = \= 283 EX. On the Causes of the Decay of the Timber in Ships, and the Means of preventing it. In a Letter from a Correspondent, - - - 287 X. On the Art of Coating Metals with Platina: by Mr. Guyton-Morveau 292 Xi. Experiments and Observations on the different Modes in which Death is produced by certain vegetable Poisons, by B. C. Brodie, Esq. F.R.S. Com- municated by the Society for promoting the Knowledge of Animal Che “mustry. = - - - - - - =" 295 RIL. Analysis of a Chinese Gong-gong: by Mr. Klaproth. le. OE Geettl. Meteorological Journal, ¢- 0° =) = = 4-7 = =! BR XIV. Chemical Examination of the yellow Resin of the Xanthorrhea Hastilis, and of the resinous Cement employed by the Savages of New Holland to fix _ the Stone of their Hatchets: by Mr. A. Laugier. - = he ee XV. Note on the Precipitation of Silver: by Mr. Gay-Lussac. - 318 XVI. Table expressing the Quantities of Sulphuric Acid at 66° [spec. grav. 1-842] contained in Mixtures of this Acid and Water, at different egrees of the Areometer: by Mr. Vauquelin. ~ - - 3:9 SUPPLEMENT vill CONTENTS: SUPPLEMENT TO VOL. XXX. » \ Engravings of the following Subjects, 1. Mr. Lester’s, Machine for washing Roots. 2. Mr, Salisbury’s Method of packing and preserving Plants and ‘Frees. 3. The Sheffield Apparatus for cleaning Chimneys without the Aid of Climbing-Boys. I. On, the Place of a Sound, produced by a Musical String. In a Letter from Mr.JohnGoughe - - - -- a feet el - S2b If. Experiments and Observations on the different Modes in whlch Death is produced by certain vegetable Poisons: by B. C. Brodie, Esq. F.R. S. Com- municated by the Society for promoting the Knowledge of Animal Chemistry. - > - - - - = 324 Itt. Description of a Mashine fer washing Potatoes, and other esculent Roots for feeding Cattle: by Mr. William Lester, of Paddington. - 336 IV, Method of packing Plants and Trees intended for Exportation, so-as to pre- serve their vegetative Powers for many Months: by William Salisbury, of the Botanic Gardens at Brompton and Sloane-Street. - - °- = 339 V. Description of an Apparatus used at Sheffield for cleaning Chimneys: by Mr. Samuel Roberts, Chairman of a Committee appointed at that Place for ipl the Sweeping of Chimneys withont the Use of Climbing-. oys. ze - - - - - 349 VI. Abstract of a Paper on the bitter Substances formed by the Action of Nitric. Acid on Indigo: by Mr. Chevreul. at - | - - 35L- VII. Analysis of Hedge H yssop, Gratiola Officinalis, of the Order Bignonia of Jussieu: by Mr. Vauquelin, - - - or eS VIIL. On the Causes which influence. the Direction of the Growth of ‘Roots. : By T. A. Knight, Esq. F.R.S. In a Letter to the Right Hon. Sir Joseph . Banks, Bart. K. B. P. R. S. - 370 IX. On the mucilaginous State of Distilied Waters: by Mr. Bucholz. S79 X. A new Analysis of Ambergris: by Mr. Bucholz. - * Fs 381 XI. Process for preparing Phosphoric Acid: by Mr. Martres, Apothecary at Montauban, and Member of several Societies. - = lai - Joa Index - - “ PRE are - 385 ‘ — INDEX A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. So PARA TET SEPTEMBER, 1811. ARTICLE I. | On the Hairs of Plants. In a Letter from Mrs. AGNES ipBETSON. To Mr. NICHOLSON. SIR, WW E study the larger and conspicuous parts of botany, Powerful pur- but we leave with a sort of contemptuous neglect all the Tagine _more diminutive features, as unworthy our notice, little extremely aware how much nature performs in this way, and how many multiplied. great and powerful purposes are auswered by apparently lite tle means, extremely multiplied. If we minutely examine all the works of nature, this will appear a very important truth; nor does any art or science show this more conspicu- ously than the study of physiology, where all are multiplied little means, conducing to one great and important end. The subject of the present letter will pecnparly exemplify this. It ison the Hairs of Plants. Ae. I have endeavoured to show, and I hope succeeded in No rach 2 proving, ‘ that the idea of perspiration in plants 1s an abso- tion in plants, lute fable,” originating from the poorness-of our magnifiers : Vou. XXX. No. 136,—Sepr. 1611. B and Source of the deception. we Another objec- tion. ar . e ‘The exterior ON THE HAIRS OF PLANTS. ‘and thatall that was taken for perspiration by botanists was one of two things: either Ist, a sort of hair, or instrument in that shape, for carrying water to the interior of plants, and performing many of those important services, which their diminutive appearance makes‘us overlook ; or, 2dly,’a sort _ “of cryptogamian plant, wholly nourished by the dews of the ‘atmosphere, and proving what they are by passing, like all other plants, from flower to fruit and seed, and showing in each various alteration the concomitant properties of each. That both these appearances have been taken for perspir- ation theré can be no doubt, since I-have repeatedly and regularly followed them in every plant peculiarly said to perspire much; and always found it either a fruit or an in- strument: and instead of being bubbles of water issuing from the cuticle (as is supposed) their make alone would ~ prove the contrary, as they could not transpire on stalks. Even the vineball is proved to have a stem; and is therefore an instrument, not a bubble. Before 1 give a more am- ple description of these, I shall adduce a farther objection to the idea of perspiration; and prove the impossibility of it by the disciosure of a discovery 1 long ago made, but would not give to the public, till perfectly convinced of its reality. I have already said, that. there is found in the corolla’ of flowers, and'in the stem of trees, aclear transparent skin, which, placed under the most excessive magrifiers;shows;no alteration of form, nor can any aperture be discovered ‘in it. The same is found on the exterior of: the: cuticles on.each skin “of leaves side of the leaf of all plants; so that it is not. possible: that & is without ~ pores, drop of water can pass to or from the imterior:in this way, though certainly air may. © Itis difficult to clear the skia from ‘all’*the marks the pattern of the pabulum Jeaves on it, which were taken by all botanists for the pores in the cuti- “ele. ‘I was once of this opinion; but I have since with such excessive pains laboured to elucidate this subject, and to prepare for the microscope upwards of forty specimens, (cleared‘in the way described in a former letter;). which in this state were. thoroughly examined by myself and others; td 7 that there can be no doubt of their being on both sides im- pervious to moisture. | They are divided into small com- | partments ‘by a parrow vessel; and. so extremely fine is the ote « ‘ z ‘skin ON THE HAIRS OF PLANTS. 3 skin, that, when placed in the sliders of my solar-microscope, itis only on turning the light in a particular direction while the eye is dn it, that it can be discovered. But the double microscope makes it very visible, let it be ever so nicely - eleaned and prepared. I am hardly acquainted with any This skin seen part of the wagetable structure, that plays so many purts, ar he ae and shows itself in so many ways, as this delicate skin. It pJe structure. was through this transparent skin I saw the dew drop enter a the pabulum. [t is probably the same skin of which the hairs are formed, which confine not only water but air. How then can water enter the interior of the leaf, which Water enters is thus guarded on both sides by this transparent medium ? Gren hate that water which is often seen underneath the skin of vege- like vessels. tables, and wholly independent of the vessels? it is to the _ hairs alone they are indebted for it; which, however simple they may appear to the casual observer, are very far from be- ing so in reality. To these indeed plants owe mary of the most delicate and important offices, nor can @ person see them once, and have a doubt remaining as to their being real instruments formed to effect some curious purpose. To give »a faint idea of this astonishing subject is all I can attempt, for to collect .a tenth part of the various instruments these hairs are intended.to represent would be an endless labour; ‘and toaccount for the use and manner of acting of a few is I fear more than | can perform well, or as I could wish. The first idea that occurs on seeing these hairs greatly They resemble ‘magnified is, that they resemble the instruments in an im- ec a ia, -mense laboratory. But great indeed must be the laboratory boratory. ‘that'could show instruments of such contrivance, figures so - various, and mechanism so astonishing, even putting their ‘size out of the question. By the most careful attention to their forms, by filling them with coloured liquids, and with art and constant practice learning to manage the heat and, light of my solar microscope (opaque as well as common), I have been able repeatedly to fill and empty a few of the in - struments, and by these means understand something of ' their construction. Batitisextremely difficult to get a liquid thin enough, as the most trifling degré of thickness chokes the valves. This was the case with extremely diluted ink: still it is to this I owe the convietien of the opening of the aa B 2 valves The various uses of the hair. The reason leaves will not bear the sun on their under * surfaces, ON THE HAIRS OF PLANTS. valves being double. I have also by observation noted the hairs always allotted for certarn purposes; but. there are many uses it is not pgssible even to guess at. Innumerable indeed are the offices these hairs perform. To shade from light and heat, to convey moisture, to decompose water, to catch and secure the drops of rain as they fall, and select the dew from the atmosphere, I have often seen them do; but these, I conceive, are but a small part of the offices they daily execute: when ao instrument is wanted for the several pur- poses of carrying moisture to the plants, catching the rain rops on their points, and defending the back of the leaf from the sun’s rays, a simple kind of hair is generally used, particularly found on the leaves of trees, as represented Pl. 1, fig. 1. This is merely a managed vacuum, which draws the water into the vessel, and thence lets it into. the pabulum of the leaf. Itis well known, that the backs of . most leaves will not bear the scorching sun; and nature has peculiarly formed and adapted the spiral. wire, to turn the leaf if so directed. It is not from any great difference in make, for both cuticles are most frequently alike on each side of the leaf; being both composed in part of :this clear skin; but the one is pressed down on the pabulum, and is always therefore moist: while the other stands much above it, and, if heated, would sooa dry up, peel off, and thus cause the decay of the leaf. When leaves are.to be defended from heat alone, and no other purpose to be answered, then, (as in coltsfoot and many other very wet planis) the hairs are form= ed like a ribbon with a quantity of threads.woven round them, and wholly without moisture. But in those which contain moisture, all the different pipes have at the bottom a contrivance for the entrance of the water into the pabu~- Jum. This perfect mechanical process I have several. times witnessed and described as the dew drops entering the cuti- cle. See fig. 2, in which the thread a contracts or loosens _.to admit or retain the water. When from a long continu. Occasional hairs bring ance of sunshine and dry weather in February or March, -when the buds of trees are enldrging, and of course much humidity is required for their preservation, a quantity of hairs will be suddenly seen covering all the buds in various directions, the sun’eracking the scales, and all the apertures boa? filled / ON THE HAIRS OF PLANTS. i) filled by a quantity of vessels shaped as at fig. 3. For seve- moisture in ral years past I have attended with peculiar care to this phe- droughts. nomenon, and noticed the sort of instrument used on the occasion. It never varies, and regularly appears to select the dew from the atmosphere. By four or five in the mor- “ing they are almost empty; by eight, perfectly. full; again emptied before noon, and late in ‘the evening 1 have seen them replenished to bursting, or running over: but how they fill themselves, except by means of a vacuum, I have not yet been able to discover. This year all the trees (or ra- Buds of trees ther the buds,) were covered with this vessel, owing to the aC long drought in March, which never fails to bring it on; it vessels. appeared as if all the buds were covered with diginiiadl In perfumed plants there is a species of instrument that Hairs of odorie baffles all conjecture as to the manner of its management, or {04S Pants, . the uses to which it is applied. This is represented at fig. 4. eforms a part of it, but is often found separate. The diffe- - rent bells bubble between each division (when part of it is - ‘turned to the sun) like a pulse glass when a warm hand is - applied to one of the balls: on turning a very hot sun on these, I once blew up two of them; and it not unfrequently happens, that the quantity within the hair, if heat is suddenly applied, bursts the vessels: but it is fortunate when it does Retains Stteatle 80, since they always break at the valve, and by this means break at the discover much of their interior formation. These instru- 4!¥°* ments are mostly found in the balm of gilead, the most per- famed geraniums, and plants that coincide in this respect. When I first saw this, and perceived the divisions to bubble, I was persuaded it was a decomposition of water; but was soon undeceived, for none of it disappeared. 1 have since repeatedly seen the effect, and been convinced, that it is sis milar to that which takes place } in the pulse glass, and caused: by the rarefaction of the air, and the increasing particles of liquid from the admission of caloric among them. Indeed every little power is visible here, nor can any instrument be Hairs uncome so fit to try every little variation of temperature, moisture, eo tn - oF evaporation, as these most delicate diminutive ones, which ee a are never idle, as long as the vegetable on which they are placed lives; liesidibid of every change, even Leslie’s differ- ential thermometer is quiet in comparison, ; ‘ ’ igs 6 ON THE HAIRS OF PLANTS, Hairs appro. =. Fig. § is the one that appears constantly used. for the de= priated for the tix j 5 . decomposition Composition of water, where it passes away inva few miautes, of water. with its usual bubbling. | Lhave often seenthe same decom- position between the two glasses of my sliders, when exposed toa very hot sun; in short, it is a process so continually taking place, that yon cannot make the proceedings of the vegetable world visible to the eye, without a perpetual re- currence of this chemical work: such a quantity of bidroe gen is wanted, not only for the juices of the bark, but for the seed, inflated with it, that the process must of course be perpetually going on. In describing the various sorts of in- struments I have observed, I have given two or three that strike as most singular; but they are in such numbers in plants, and so various, that I have found it difficult tose- The eryptoe lect them. Itis not uncommon to see several different sorts ae eee of jnstruments on the same’ plant, apparently appropriated: taken for the to avariety of purposes, nor is it possible to mistake the fruit instruments, for the jnstrument: the latter so much resembles the’purest erystal, and their forms are so extraordinary, their valves so truly mechanical, that no person can see them, and take them for any thing but what they are, ** an instrument ;” nor did I ever show them without exciting an exclamation of surprise. I have once or twice found them inflated with a green liquid; but this is very rare. This is the case in the lave-apple. What in that plant was supposed to be pere spiration is a small instrument of this kind (see fig. 6), The most exe Extraordinarily figured hairs are rarely to be found, except traordinary jy herbaceous annuals, or small plants. The wild plants orp gat exceed the cultivated in assistance of this kind. It would plants. seem, that, when art Jends her aid, nature is less attentive to the preservation of her nurslings: though I believe it re- quires many years cultivatiqn to lose any of them, still I Extraordinary have found occasional hairs oftener on wild plants than on’ hairs seldom garden anes, and double flowers almost banish them. Trees waite and shrubs have seldom any but simple formed , hairs, if ' those with double cyses or valves deserve this epithet; but occasional assistance of this kind is perpetually found, pars ticularly among exotic trees. Nor are hairs found offen ‘on evergreens; they would undoubtedly burst.with the. first frost of winter. The.firs also are void of all assistance of this “ kind, ON THE HAIRS OF PLANTS. 7 kind, except now and then on the calyx of the leaves: and then I have observed, that the water gets mixed with the re- sinous juice of the bark, which coagulating bursts the pipes. These hairs are also very different from those which are fixed to the flying seeds, &c., for they resemble the coralines, and the bones of fish; indeed the exact likeness of these three different objects is very striking and curious. The hairs which surround the buds of trees, and are generally wound round them, are never inflated till wanted, and till a certain time in the formation of the bud: when black (as in fraxinus excelsior, juglans regia, and many others), the valves are admirably seen to open and shut in a large mag- nifier, admitting and passing the water through the black lines. ? That the hairs alter their forms,.1 have many proofs, Hairs alter Doring great drought I have seen those, whieh were before they Forms plain pipes, swell into divisions between the valves, changing their form from that at e fig. 7, to that at ti and_ plainly proving the shape of the valves to be as fig. at g. On placing: fig.8, Pl. I1,in the solar miscroscope, after great bubbling and confusion, I took it out, and found the ribbon changed from the appearance it has at A to that at 7. It appeared asifit had been before inclosed in another case, which case had melted. away with the heat of the sun, and left the inclosed balls.and. s‘ring uncovered. Ihave so often seen the same result from repeatedly placing it, that I cannot doubt that this is the case. The divisions k k are often found attached to different. ~. +» +. shaped instruments, ending sometimes in bells, sometimes © == —~ in plain pipes; contracted, or inflated, as the occasion re= |. see ay quires. Nothing can be more common than fig. 9, which:ia ‘ always full of water; and fig. 10, which is found on the ga= hum aparine. Extraordinary as is all I have related,: itis hot more wonderful than true. Iam the first person that __. may be said really to have turned the so!ar microscope on the botanical world; is it then incredible, that I should have wonders to relate? did any person ever take a miscroscope- im hand without it? | ro * Tshall now turn to the cryptogamian plants, equally taken Tessigiion of for’ perspiration, and described: by all. botanists as such. the crypto- — Many of ‘them resemble the powdered lichens, when they 614” plants. corre an ; begin Fruit known by its various changes ending in seeding. Innumerable offices the hairs perform, Different from the armature of plants, ON THE WAIRS OF PLANTS. to go toseed, though at first appearing like a drop of water, which, even while your eye is on it, turns white, and soon be- comes hard and firm; changing to seed. These are found: on the mint, the pea, and innumerable other plants, said to perspire much, That which Hales took for perspiration on the leaves of the sunflower 1s a sort of mushroom, extremely moist, shown at fig. 11, w; and that on the vine, fig.12: but. I must stop, or my sketches would never end. [ observe that the cryptogamian plants on the rose, and many other plants, because red, are allowed ‘not tobe perspiration: but surely the proof is not in colour, but-on the matter passing from flower to fruit and seed, which all this sort does ina day or two; yielding generally a‘sort of sirup, and equally nourished by the dews of the atmosphere: and certainly. equally unfit with the hairs to be reconed perspiration. I flatter myself therefore, that this will serve to pbb dca these who still doubt, Ee DBC If I were to mention all the different officbd to which “i hairs are applied, it would be endless. To catch, convey, and mix, the powder of the stamen with the sirup of the pis- til, they are peculiarly adapted, having in each hair a duct for conveying thé mixed juices, when melted, to the canal in the pistil. All this is plainly seen, since in the solar micro- seope each hair is as large as a walking stick, How many. various offices do the hairs perform in the corolla, calyx, and stipula! There is one peculiarly appropriated to this latter part, in all diadelphian plants, most curiously formed. How wonderful is the hair in wet plants! placed to guard the air vessels from being filled with insects, they exactly resemble ewords, shoot ina circle and meet in the middle of the vessel. as at fig.7. How many an insect and water-fly have I seen: run through by them! But this is not all, they have a sort: of spring, which makes the hair strike down, and thus get rid of the creature it has threaded. When | give my letter. on water-plants, J shall show the mechanism of this hair, which is as wonderful as any of the preceding accounts) This subject should not be made to interfere with the ‘ara: mature of plants, which is wholly of a different nature, and consists but of two sorts of thorns; the Ist like those‘of- the yose, the acacia, the gooseberry, &c., is formedentirely of m7 > the ON THE HAIRS OF PLANTS. 9 the -rind,-and an excrescence of it; probably arising from an® extreme tendency-in that part to grow in the same manner ag the quercus suber, the ulmus campestris, and many others, the rind of which is a sort of cork, always increasing: The 2d sort of thorn is that which in the crategus is a dis- order in the tree, to which some plants are peculiarly sub-' ject: a sort of missed bud, from the stoppage of the line of life,caused probably from the momentary check of thejuices, © “* --* on some sudden alteration of the weather; as I have observ- 54 ed, that, when the barometer and thermometer are without much variation, except the natural one of day and nightin the latter, no thorns come out. J have measured at such a: time a shoot three quarters of a yard long, without a thorn. But when in the spring alterations are frequent, the branches. will be scarce two inches, and always ending in a long one: and on-dissecting this, the line of life will be found to have stopped, before any other part of the plant. _d intended to give merely a sketch of this ce till I Hope to intro- better understand how to inflate the hairs with a coloured enral liquid, and till can more thoroughly comprehend their uses in detail. and management; for this indeed I should have waited, but that it was absolutely necessary to prove, that I would not have written against the perspiration of plant, without a complete conviction of the truth of my assertion: * that the. whole system of perspiration could not be supported against the absolute proof the solar microscope adduees of its false- hood.” If 1 were rich, I would certainly have the instru- ments imitated in glass, properly magnified (if it could be > dene) as [I think much might be learnt from it. It is the mechanism of nature: we talk much of its simplicity, but it surely consists only in not making use of more contrivance than is’ necessary ; ; and when the mechanic powers are’ wanted, can we do better than study them from models‘so perfect, forms so wonderful? and though we could not suc=' ceed in forming a sort of air pump in a hair; yetit might° serve to teach us to'simplify our ee) — to rectify” many of our pristakes, : . ee . Your obliged servant, © 0 Wokiey Cottage, > a “AGNES IBBETSON: Poly agthyeyerI 09% seco y | dd 804 RM I, 1p Inquiry cone cerning the Ratural eco- momy of ants, Speedy alte- yation of the stone wsed for building at Paris aTUCCO- FOR PRESERVING STONE. i 7 Orn Inquiry concerning the Natural Bicnaiig? fe Antes Tn’ me “Letter from a Correspondent.’ a} Bets To W. NICHOLSON, Esq. inate 3 SIR, Spipain ate merepeen rte ae ies | cle Havine always observed, , since T first Se take paid the kindest attention to the 1 inquiries of such as wish to be informed on the interesting subjects embraced by your plan, I feel almost confident of your permission to request, through the medium of your journal, the’ communication of such original facts and observations relative to the natural economy of different species of ants, as nay have occurred to the notice of any of your numerous readers. It appears to me, that, striking as the habits of this genus of insects certainly are, the subject is, as yet, rh no means generally wel] understood. Your compliance with my ais will be besa nae a pesticular favour. I am, Sir, Your obedient humble servant, _ W. a. B. ; — - ° 7 region se “ nO Ny Report of a Committee, consisting of Messrs. Rertholet, Chaptal, Vauquelin, Le Breton, Vincent, and Guyton-Mor- veau, appointed by the Institute to inquire concerning the’ Process of the late Mr. BACHELIER, bat the Composition of 6 preservative Stucco*. ‘kid he was in 1755 that Mr: Bachelier, struck with the speedy alteration of the stones employed i in the principal buildings at Paris, and the inconveniencies of the process employed. from time to time to renew their surfaces, Proporssy to rd "super STUCCO FOR PRESERVING STONE. 1 superintendant of the royal buildings to try a preservative prevented by a stucco. Accordingly three pillars in the court of the Lou- ¢°™position, vre were coated with this. stucco for half their length, two facing the south, the other the west. These were still re~ markable in july last for the uniformity of their tint, strongly distinguished from the dull gray and earthy aspect _ of the contiguous parts: but as ‘the alterations made in com- pleting the Louvre would necessarily destroy every trace of this experiment, the Institute appointed 9 committee to. © © inquire concerning it, before it should be too late. met pntss Tn company with Mr. F ontaine, architect of the Louvre, too thin to i in- the gentlemen abovementioned examined the pillars, and sacs: found, that the stucco appliéd formed a coat too thin to injure the finishing of the most delicate sculpture ; that it retained a uniform colour even in the parts exposed to the and unaffected action of the wind, rain, and sun; that rubbing it with the hey Bitci hand. made no impression on it; and that, e one of the three pillars exhibited a reddish yellow tint, there could be. no doubt, from its appearance in other respects, that this was owing to. some colouring matter added intentionally. | It could not be found on inquiry, that Mr, Bachelier Account of it had consigned his process to writing, and the following was ric i ar i the best..account his son could give of it from memory. ventor’s sons ** Its basis consists of the sifted powder of oystershells, pre- viously washed and calcined to whiteness, mixed with the butyraceous and caseous part of milk. My father used the common cheese known by the name of fromage a la pie [skimmed milk cheese?]. He first separated all the wheyey part by pressure, and then left it fome time exposed to the. air to. dissolye or soften. In this state he mixed with it a quantity . of calcined oystershells in fine powder. When this. mixture . .was brayed on a stone, the cheese softened, and formed a very smooth and whitish liquid paste. To nake the stucco he diluted this with a solution of alum in vater; the quantity of water being proportioned according b the thickness of the cuat eed to be applied.” _Mr, Bachelier could say nothing of the proportions of Paper coated he ‘ingredients, he only added, dhee, his father having he ane hought of employing this composition undiluted to cover could be ef. Paves of paper, from which writing was easily effaced by a aig wet 32 STUCCO FOR PRESURVING STONE. wet sponge, he observed, that the oystershell domder was taken at random, and added to the cheese till it had ac- quired the consistency of a paste capable of ae spread on “> paper. Oxide of leaq. ~~ Fhe “committee vide Neate rie Mr. Buchelier a i ih few leaves of paper covered with thin paste, found from the very deep black immediately given it by the hidrosulphuret of potash, that it contained a considerable quantity of oxide of lead, the presence of which there was no reason to sus- pect in the preservative stucco, so that they canteh a not be ‘considered as the same. Arslysisofthe !t remained therefore to analyse the stucco, nies. wage Rave, done by Mr. Vauquelin; though, as a very-small quantity only could be obtained by scraping the pillars, it did-not admit of repeated trials. The results of his analysis gave Carbouate of lime@eovecesdscvecvcvevceee O39 : Sulphate of Fittie ee ok. LEM BU WER ROL 793 ‘Carbonate of leddes % deed ug. taard. ba ge Oxide of iron, about os. cee e sed vec er edeee) A {Biles NBR Pele eee aid be PWT Sg ipa ‘ereho al wee ce Wwe a Mn cahane ‘eine eee Al gagehl Chute EeRERNS 20 y Organic matter, an indeterminate quantity - é (eS .102°73. The surplus of 2°73 Mr. Vauquelin ascribes either to bbe: - matter ngt having been dried to the same degree, or to the escape of a little carbonic acid during the calcination, «| Nasnimat’ “Phe presence of animal matter was sought for, but not Ee ial a particle could be separated. The smell it ; emitted during wert smell of €aleination wo way resembled that of aminal matters; on peccheapeibhe oF the contrary it had the pungent sharpness of vegetable substances. On being exposed to the action of heat in a’ retort however, a clear and almost colourless liquid came’ aver, frdin which potash expelled a very evident ammonica’ Indicationsof wipour. “This indicates, that some animal substance en- a + ae male tered into the composition, but that in time it was decom posed, and left only an ammonical salt. The brownish colonr it acquired i in the fire also proves, that some, anima patter still remaimed in it; though altered. in its nature, since it neither emitted the smell proper to such substances’ wor’ yielded any preceptable quantity of oil. Lastly, STUCCO, FOR.PRESERVING STONE, 13 ‘Lastly,: this’ matter yielded; uo appreciable quantity of No alumine. alumine, so thatt-may be presumed no alum was employed. in the composition, . Mr. Bachelier having” some of the paper that had been Analysis of the _ prepared by his father, the coating: of this was analysed sand Paper coating. the result indicated, that. ~Quicklime © 2 seeeccceccsccveccccscres 56-66 . Calcined gypsuin «es Sr eis eis bie seca srethietiuctenes 1291S. _ Ceruse or carbonate of leadecsceceseences 20 had entered into its composition. On these proportions more dependance can be placed This more te than on the former, since it was impossible to detach the ah al plaster from the pillars without some of the substance of the — stone itself. That the caseous part of the milk is the proper Beit) for Cheesy matter the powders we learn from the positive testimony of Mr. Ba- “® veh! chelier, the son; and its utility is confirmed by the iad ments of: Mr. d’Arcet published some years ago*. : Of the efficacy of Mr. Bachelier’s composition there can Efficacy of the be no doubt, as we have irrefragable and still existing testi- neal aartrg mony of it; nor would it be difficult to estimate this before- hand, when we consider the causes, that produce the gradual decay-of the finest buildings in this capital, and the means of guarding against them. » Hard and fine grained calcareous stone, susceptible of a Stone not fia- greater or less degree of polish, is not liable to this altera- ee ae tion. Itis therefore owing to the nature of the stone com- monly employed, which is of a loose and unequal texture, and liable to it, filled with cavities, and found hy analysis to contain 10 or - 12, per cent of silex, and frequently 3 or 4 of oxide of iron. The difference of the stones from the quarries near Paris is evident from the tables of Mr. Rondelet, in his Treatise on the Art of Building; where wesee, for example, that what is called the grignard of Passy is of the specific gravity of 27462, and supports a weight of 6750 kil. ; while the dame bourde of St Germain has only 1°560 sp. grav., and is '* Déc. phil. an X, No.5. The pamphlet entitled PArt de peindre au Fromage, ou en Ramekin, which Mr. d’Arcet regrets his being unable to procure, was foreign to the subject, as it related to painting with soap * wax, [See Jourmal, Vol. 1, p.212.] crushed 14 Spiders form their webs on these stones. STUCCO FOR PRESERVING STONE. erushed by a weight of 921 kil. The prices of these two kinds of stone differ too in the proportion of 26 to 10. It is not at all strange, that the little spider called by Linneus senoculata, the cellar spider of Geoffroy* » should find on the surface of this stone a convenient situation to shelter itself, deposit its eggs, and spread the nets in which it awaits its prey. Its web extends circularly round the ca- vity, that serves as its den, forming round spots of 3 or 4 cent. [1 in. or 12] radius. Itis not thirty years since the hoted des monnoies was built, and I have counted no less than sixty- eight of these dark gray spots on one of the pillars of the vestibule. Similar ones are found not only on the stone, . but on the coatings of plaster, and on the walls covered with ” Mode of pre- venting this. common stucco. It is particularly in the joints and angles, that the insect begins to fix itself. I have seen several on walls, the stucco of which had been coated afresh within less | than seven years. These spots at length form a continued ‘coat, retaining the sloughs of these insects, ‘the remains of those on which they feed, and the dust raised by cos wind, so that lichens soon take root in them. If it be asked, how is this to be prevented? the answer is easy. By a composition that resists water, will adhere to the stone so as not to scale off, has a sufficient degree of con- -sistency to stop the pores accurately, is liquid enough to be spread as a wash, and uniformly to ice over, as it were, all the saliant and indented parts, without thickening the angles _or blunting the edges, and lastly which gives to the assem< Other means, blage of coarse grains the smooth surface of polishable stones, in which it appears these insects cannot néstlé. And this we think may. be expected from Mr. Bachelier’s stucco, Meantime I must observe, that, in the present state of . our. chemical knowledge, other means of fulfilling these con~ “ditions may be pointed out. We know for instance, that ' phosphate of lime is one of the most fixed combinations: it would be sufficient therefore, to wash over the stone with ‘phosphoric acid more or less diluted, or with phosphate of 5 lhe dite lead, magnesia, &e., wels in solution by an exeras of - a * Mr.'Latreille neatnts me; that he tis found the same habitéi in tLe _ ter’s aranea atroz. u, their STUCCO FOR PRESERVING STONE. 15 their acid, to give it a sort of covering, that would render it as unalterable as the stone of Logozan in Estramadura. It is equally known, that sulphate of barytes resists all agents in the humid way; and we might certainly coat the stone with this earthy salt, by first impregnating it with a solution of sulphate of iron, zinc, magnesia, alumine, &¢., and im- mediately washing it over with barytes water*, The inso- lubjlity; of oxalates and tartrates of lime, and the adhesion they. contract by deposition even on polished substances, ~-$u ggest processes for washes not less solid; as the acids added ‘to these salts to yender them temporarily soluble, saturating themselves with their base from the substance of the stone itself, would not fail to connect together all the grains, fill — “up. their intervals, and completely close the pores. Trials ‘ made with a view to ascertain the justice of this reasoning have confirmed the expectation of a successful result; sinee on the most porous stones they have produced a surface, on which the eye could see no appearance of coating, but which, being rubbed with wet black cloth till the cloth showed signs ef wear, was not in the least soiled by it. _ Preparations of this kind however would be much mere The latter too expensive. than Bachelier’s stucco, so that their use must be pensive. fepastet, to the preservation of sculpture of extreme deli- cacy. 42 ‘For farther satisfaction trials have been made with diffe- Generai re- . rent. kinds of | stone, and stucco made in imitation of Bache- suits of expe lier’ s. These have given rise to the foliowing observations. aioe shail iL. All the compositions in which alum water was employ ; _ed soiled the fingers, and were washed off by water. - 9, The cheese. that acquires the greatest consistency with _ dry substances i is that which is almost entirely deprived of ithe butyraceo us and wheyey parts. Mr, d’Arcet, in the ‘paper already quoted, had remarked, that these were more detrimental than useful, that painting with milk would not | resist water, and that the cheese called Sromage dla sa might oad Aceident furnished Mr. @Arcet witha striking proof of the readi- Filtering stone “’ mess with which this change of bases by superior affinity will fill the pores spoiled by ac- ef the most porous stones. A capsule full of strontian water happening cident. . (to be overturned inte a filtering. stene, it never after let through a single drop of water, ” be 16 STUCCO FOR PRESERVING STONE. be used after it had grown dry, though less advantageously than when fresh made and well Saliva ° 3: A mixture of this cheese’ with lime simply forms a paste, that adheres but slightly even to coarse grained meat and not at all to paper. Proportion of Preparation of cri Calcined g gypsum, which in a small dose facilitates the union of the lime and cheese, renders the paste ae and ‘celotty, if it be used in too large proportion. 5. It had appeared, that whiting, which is used in paper hangings, might be admitted into the preparation: but it was found, that, if this earthy substance, which in a pro- cess described by Mr. d’Arcet is carried to twenty times the weight of the lime, may be used with success for inside work, it would make too thick a coat, and would not adhere ‘so strongly to the stoue. ~~ 6. 'The addition of a very httle ochre, or red oxide of irén, to this preparation, will give it such a tint as may be wished, without altering its properties. , The proportion of cheese must depend in some measure on the state in which it is, and cannot. be determined pre- cisely but by the condition of making a soft paste. A fourth of the weight.of the solid matters appears to be a sufficient “quantity of cheese fresh from the press. The quantity of lime to be used at once being deter- oink mined on, it is to be slaked in as little water as possible, ‘but he S eo < Fgh ¢ “enough to make it pass through a sieve not very fine, in or- der to separate the parts that will not slake. This is to be _triturated with the cheese to the consistence of a soft, smooth, and coherent paste. To this are tobe added the sealcined: gypsum and the white lead, which must-not be adulterated with chalk, and by farther grinding on the stone owith’a little-water the whole is to be reduced to a pap, rather thick, than fluid, Lastly it is to be diluted with common -water the moment of using it, which is to be done witha painter’s or varnisher’s brush. - « @BSERVATIONS ANB EXPERIMENTS ON FUs. a7 IV. Obser vations and Experiments on Pus. By Groner PHARPOWs M.D. F.R.S*. Benc AL writers vary in their statements of the pros Properties of perties of pus; and they consider, that a farther investiga- eins ¥ a tion is requisite, for the purpeses of science. Pivaciaus confess, that, in numerous cases, they cannot form a satis- factory judgment of the nature of diseases, on account of not being able to determine what is, and what is not puru- lent matter; iikewise probably, on account of the existence of different kinds, or varieties, at least, of this substance, afforded by different. disorders, I beg leave, therefore, to submit to this learned Society, my own obseryations, experiments, and reasoning on this animal matter. ; ‘Secriow’I. Simple, and obvious Properties. The different kinds of fluid, commonly considered to be Different kinds pus, may’ be distinguished by the following titles ; . of pus. 1.» The creamlike and equally consistent. Il. The curdy and unequal in consistence. Hi. The serous and thin kind. IV. The thick, viscid or slimy. 1. A pint of the first sort was taken out of the pericar- Propertise of deen: after a fatal inflammation of the heart, in St. George’s ilies Hospital, and obligingly sent to me by my colleague, ei E.N. Bancroft. ~The colour was yellowishoothe smell was fleshy sh ‘warmed—it was smooth and: unctuous te the touch. 2. The specific gravity of two different portions was ae 1630 and 1633, that of distilled water being 1580; each substance being of the same temperature. Sernm of the blood of different patients, was found at the same time'to be 1626, 1627, and 1630. Accordingly, the distilled wae ter being 1000, the pus is 1031, and 1033; and the serum is.1029, and 1031. e es a sii Se * Philos: Frans. for 1810, p. 204. . Vou. XXX.--Sepz. 1811. Cc 3. After is ot the 2d kind, OBSERVATIONS AND EXPERIMENTS ON PUS. -8. After 12 hours repose, about two ounces by measure of alimpid fluid having appeared on the top, it was-de- canted from off the opaque purulent fluid; which was be- come thinner ia the upper part of the vessel containing it; and thicker in the lower than before. y _ 4, On farther repose, it did not become offensive so soon as a portion of the same as mixed with a little blood, or as serum alone. . 5. This pus neither indicated acidity nor alkalescency to the usual tests, viz. turnsole paper, tincture of red cabbage, Brazil-wood paper, and turmeric paper. I have, in other instances, sometimes observed acidity. to be indicated by turnsole paper; but in none allkalescency, so long ; ag the matter remained without foetor, 6. Being examined under the microscope, eu duly diluted with distilled water, innumerable spherical particles were seen, which did not appear altered in figure, or dimi- nished in number, by.extreme dilution; that is, REY did not appear to have been discolved. | I]. A pint of pus of the second kind, viz. curdy, was ‘afforded by a psoas abscess... _'The colour.was brown, It felt knotty. On pouring from one vessel to another, the curdy masses were manifest, and of various sizes, fram that of a pin’s,head to a hazel nut. It was more viscid than the former, and of a little greater specific gravity. On standing, a limpid fluid ap- peared upon the top, as in the first kind, but im smaller -quantity.. Globules were, seen with the microscope, but .also.a number of irregularly figured larger masses. Pu- trefaction took place sooner than in the former kind. In sother properties, this pus was similar to the first kind. of the 3d kird, e LL Serous thin pus. It was ‘produced by a fatal inflam- mation of the peritoneal coat, without ulcer, and taken out of the cavity of the abdomen. .A good deal of serum was also effused, of which the pus was a deposit. It was not “much thicker than milk. To the feeling it was not at all unctuous. . The smell was slightly offensive.” On standing 94 hours a’sediment appeared, occupying only one half the full vessel, under a wheylike liquid. Putrefaction took place sooner than in either of the two former kinds. The qeilg > ~ 5 Oy ae SE SRR > a a specific cry a OBSERVATIONS AND EXPERIMENTS ON PUS. 19 specific gravity was the same as that of the first sort. In other properties it was similar to the creamlike pus above ‘distinguished. EV. A pint of the viscid pus was Sneieen from an ab- and cf the 4th, seess among the muscles of the thigh. If 1 had not had entire confidence in Mr. Brodie’s accuracy, who was so obligivg. as to attend to my request, on this and many other like occasions, I should have supposed, that this was expectorated matter, it so exactly resembled in its simple properties the ropy kind, described in a paper on expecto- rated matter. Phil. Trans. 1809, P. II, p.317*. "The appearance was not quite uniform, there being semi- transparent masses io small proportion, mixed with the perfectly opaque white matter. It was almost inodorous, To the touch it was quite smooth. The specific gravity ‘was nearly that of the second kind of pus. On standing 24 hours, about ore ounce meas ure of ii. pid fluid rose to the top of the whole mass. Putrefaction did not take place so soon &s in expectorated matter of the sume consistence. The examination by the microscope manifested innume- ‘rable spherical particles among leafy masses, and numerous particles of irregular forms. . The simple properties were otherwise similar to those of the other sorts of pus, above distinguished. “Many other differences of purulent matter are universally Other diffe recognized; but they are either varieties of the four kinds already named, or the differences depend upon the obvious ‘mixture with adventitious substances; such as the red part of the blood, coagulated lymph, serum, putrefied matter, fibrous and membranous masses, calculi, &c.: therefore, I deem it useless to describe them. sali Seer. U. Agency of Caloric. 1. The, above kinds of pus coagulated like serum of Action of heat blood, into a firm, uniform, foft solid, at the temperature 97 P45 _of 165° ‘completely ; but partially at 160° of Fahrenheit’s thermometer. * See Journal, Vol. XXV, p. 220. “ciel set dts g C2 2. The 20 OBSERVATIONS AND EXPERIMENTS ON PUS. 2. The decanted limpid fluid from pus, Sect. I,~I, I, Til, 1V, coagulated completely into a tirm uniform mass, like serum of blood, at 165°, but it became opaque and thickened at 160°. By pressure of the firm curd thus pro- duced, a watery liquid was separated, which on due evapo- ration did not give a jelly, but was coagulable like the de- canted liquid just mentioned. The thick opaque matter, after decanting the limpid fluid, coagulated as before said, into a firm mass at 165°. Evaperated to 3. Each of the above four kinds of pus, being evapo- psi tiKs rated to dryness, left in no case less than one tenth of its original weight, er more than one sixth; but most fre- quently one seventh or one eighth of brittle matter. The smallest proportion of residue was left by the 3d, or serous kind; the largest, by the 2d or curdy. These residues gene- tally became rather soft, especially those of the 3d, or the serous kind, after exposure to the air. A. The opaque part of pus after separating the limpid fluid afforded on evaporation from 7!; to 3'5 more of brittle residue, than an equal weight of the pus itself; and it re- mained hard on exposure to the air. The limpid fluid, “evaporated to dryness, yielded about one tenth of brittle Residua, residue; which grew moist, and sometimes deliquesced, on exposure to the air. 5. The brittle residues above mentioned (3), being exe posed to fire in platina crucibles, flamed for some time, emitting a very offensive, pungent, empyreumatic smell; the uninflammable residue being kept in a state of ignition ‘for a longer period, what remained at length was fused readily from the serous, viz. the third kind of pus; but in the cases of the other exsiccated residues of the Ist, 2d, and Ath kinds of pus, they barely were melted, or only became soft and claggy. The fused residues from the serous pus amounted to 31; or z'; of the exsiccated pus; and to 31, or | me) the original purulent matter. Those from the second - kind, the curdy, amounted to ;'y or jy of the dried matter, and to 54, or <4, of the pus itself. The fused masses from the 1st and 4th kinds of purulent matter afforded interme- diate quantities of melted matter between those just men- tioned. 6. The OBSERVATIONS AND EX PERIMENTS ON PUS. 91 6. The fiscd residues (5), being treated in the manner described ina former paper, Phil. Trans. 1809, P. II, p: 826—329 *, ‘I found they consisted chiefly of muriate of a phosphate of lime and, potash; with strong indica- tions of carbonate of lime, and a sulphate ; beside traces of phosphate of magnesia, oxide of iron, and vitrifiable mat- ter, probably silica. On a reasonable calculation, it ap- peared, that in the serous kind of pus, the muniate of soda amouats to from one and a half, to two per 1000; the phos- phate of lime from one, to.one and a half per 1000; the potash from one half, to three fourths of a part in this quantity ; and the other matters together, to half a part in 1000. In the eurdy matter, the second kind, the muriate of soda amounts to from three fourths of a part, to one in 1000; the phosphate of lime to one; the potash to less than one half; and the other matters united, to half a part in 1000. The first kind of pus, the creamlike, and the fourth, the viscid, afforded from the melted residue the same substances as the serous kind, excepting a somewhat smaller . proportion of muriate of soda, and potash. sz The brittle residues of evaporated pus, after decante ing the limpid fiuid (4}, being treated with fire as above re- lated, the remaining matters were melted with more diffe culty, and less completely, and contained a smaller pro- portion of muriate of soda and potash than the original pus. ¢ . 8. Fhe decanted limpid finids (4), Gsiee, eenamd to fer aces, these residues were exposed to fire. _They were melted, and then afforded a larger proportion of muriate of soda and of potash, than the pus itself; but with the same proportion of the other saline and perby st substances. ia IIL. Agency af Water. 1. After decanting the limpid fluid from off half a int Action of wa- of the four kinds of pus as: above related, (Sect. I,): three ‘et 9 Pus ounces by measure of distilled water were mixed with each of themi. After 48 hours repose, a limpid fluid ‘of nearly the quantity of two ounces by measure was seen forming | 2a solution. 3d solution. 4th solution, : ‘ E OBSERVATIONS AND EXPERIMENTS ON PUS. forming an upper stratum tothe pus. It was decanted for examination. (a) On exposure to fire it became turbid a milk, as soon as the temperature was elevated to 105°, but did not become thicker at a greater elevation. (b) On ev aporation to dryness, the residue amounted to about one fifteenth of the weight of the liquid from the see rous pus, and to one twentieth from the three other kinds; | in place of about one tenth, as from the first decanted li- quid, (Sect. I, 4); and as from serum of blood. "Fhe resi- duary matters were of the same kind as thoge above de- scribed, Sect. Il, 2—6. (ec) Three ounces by measure of distilled water having ‘been again mixed with each of the four kinds of pus, and, in 48 hours, two ounces measure of decanted limpid fluid’ from each having been evaporated to dryness, residues of the same kind, in the same proportions, and ia nearly the same quantities as before, were obtained (b). These de- canted fluids became nearly as turbid as the former, on raising their temperature to 165°, : (d) Distilled water was added a third time, in the quan- ‘tity of eight ounces by measure, to each of the four parcels of pus under examination; and, after 48 hours repose, six ounces of limpid fluid were poured off from each of them. At the temperature of 165°, the decanted fluids became tur- bid; that of the serous pus more so than the others. On evaporation to dryness, a much smaller quantity of residue was obtained than before, viz. one sixtieth from the serous pus, and one seventieth from the others; and it consisted of the same kind of substances as above described; but the muriate of soda and potash were in smaller proportion aise before. : (e). A fourth time distilled water, in the quantity pe a pint, was mixed with the present four parcels of pus; and, after standing 48 hours, three fourths of a pint of clear colourless liquid was poured off from each of them. It became slightly turbid and whitish on boiling. On. eva- poration, each parcel afforded ahout 5 of the fluid em- ployed. The residues now consisted of animal matter, with @ much smaller proportion than before of muriate of soda, phosphate OBSERVATIONS AND EXPERIMENTS ON PUS. o3 phbdptlace of lime, and potash— nothing else could now be traced. (f) Distilled water, in the quantity of a aii, was once 5th soluticn, | more mixed with the four sorts of purulent matter under- | going inquiry. After 48 hours, a pint of liquid ‘was des ‘eanted from off each of them; but being slightly turbid, they were left to stand 24 hours. By this time a sediment was deposited from each of the liquors; but being sull, though very slightly, turbid, they were filtrated through . suitable paper. They were then transparent. The trans- parent filtrated liquors had their transparency disturbed by a boiling temperature. They became also slightly milky } with nitrate of silver, but scarcely so with infusion of gall put. On evaporation to the quantity of an ounce from each pint, the residuary liquids appeared slightly globular. These, on evaporation to dryness, yielded not more than oné part of animal matter, from each 500 of cae shi He Wt fil- trated liquids. (g) On standing three or four days in a cold room, the Residuum. parcels of pus, after the abl utions just related (a—/f), exhi- bited a whey coloured liquor at the top, of which about 2 of a pint was poured off from them. More turbid liquor was also separated from the washed pus, by pouring it upon a porous cotton cloth strainer, which left purulent matter of ‘ the consistence of starch mucilage, amounting t to about one half the original weight. (hk) The pus freed from coagulable limpid liquid. by re- Jts properties. peated ablutions (a—h) was white as snow—equal in con- sistence—perfectly smooth—the 4th kind was less viscid than before, but the others were more so—no smell—not at all disposed to putrefy—on elevating its temperature to 165° and higher, it did not coagulate into one mass, nor into clots, or large masses of curd, but a watery fluid separated from a ne fine soft somewhat curdlike opaque fluid ; which did not be- come more curdy, even on boiling—it did not appear that above a grain of this part, or state of pus, dissolved in 1000 waters—was highly globular under the microscope, and re- mained so, although coagulated by nitrate of silver; by ine ‘fusion of gall nut; by alcohol; and supersulphate of alu- mina—with muriate of ammonia, nitrate of potash, and other “kets neutral QA OBSERVATIONS AND EXPERIMENTS/ON PUs, néutral salts, and with carbonate of potash, it produced a viscid semitransparent mass like expectorated half transpa- rent matter-——ex posed to fire in a platina crucible, it was in- flamed, but did not emit an offensive smell, and-after-conti> nuing the ignition, the residue was a particle of half fused matter, not amounting to.,¢55 of the pus after ablution, nor above +=}, of the same matter exsiccated ; it consisted éf phosphate of lime and vitrified’ matter—no ammonia was perceivable, on mixing lime with this washed a ai nor mus riatic acid on adding sulphurie acid. ite racine 2. (a) A tea spoonful of the creamlike.pus; ‘hiete agitated. ina@s us”. agitated if wae 10 half a pint of distilled water, produced a milky fluid, with ter, a number of small curdy particles suspended; but very few leafy or fibrous pieces or clots. (6) The serous pus being treated as juft mentioned (a), : ) the same appearances divtiedi 2 (c} The curdy pus being agitated in the same manner in water, a number of clots, leafy, and fibrous masses, were seen suspended among ave small curdy ies | ina a pearly jiquid. (d) The wiscid pus being treated as just ‘ald; it ferjutree Jong continued and Violeitt agitation, to diffuse it through the. water, and then the Sila iy were as last de- scribed. Boiled. 3. Pus of any kind, piss boiling in twenty times its quantity of water, was quite as globular under the micro~ scope as previously. With a smaller proportion of water, the mixture became very turbid, sometimes clots. were formed in a pearl liquid, in which a fine ‘sediment took place, which appeared much more globular than the clots or curdy masses. 4, In general, water in which pus has been agitated re- mains somewhat milky, with an abundant close white sedi- ment; but after two, or three, or more ablutions, the water becomes clear on standing, and the seciniaatm more curdy. r ‘ CL LS? sean. Iv. - Az Saab Alcohol. lof Wines. inhib ae. Action of al. The different kinds of \exsiecated: pus’ exposed to the gahol on pus. agency of this menstruum, and treated as described in a former OBSERVATIONS AND EXPERIMENTS OW: PUS.° former paper, Phil. Trans. 1809, P. Il, p. 329*, the re= sults were similar, except in the proportion of products. 1. These exsiccated substances afforded to this men- struum a smaller proportion of potash, but as much animal oxide and muriate of soda, as mucous sputum. «2. Phe undissolved matter left after repeated digestionsin in this menstruum afforded the same substances, but in smaller _ proportions,:as mucous sputum. »%. Equal bulks of fresh pus, and rectified spirit of wine, afford a much thicker and more milky liguor, with a closer sediment, than expectorated mucous matter, Seer. V. Agency of acetous Acid. The purulent matters mixed with this acid became curds, and rendered it milky; but on standing, a close white sedi- ment appeared, the liquid above being clear, except in the case of the. viscid pus, which exhibited leafy and fibrous masses, as hath been described with mucous sputum. _ By repeated digestion of the different kinds of pus in this menstraum, [obtained the same results, except the pro- portions of acetite of potash, and muriate of soda being smaller, as related in.a' former paper on mucous expecto- rated matter, Phil. Trans. 1809, P. LI, ‘p. 336. I Seot. Vi. Some Experiments with different Objects, espe- _cialiy to distinguish Pus and Mucus. L In the agency of sulphuric, nitric, and muriatie acids, in ‘sufficient quantity to dissolve and decompound the sub- stances under i inquiry, I could perceive no important diffe- rence between them. The purulent matters indeed re- quired a much greater proportion completely to dissolve them, than the transparent sputum. Also the more opaque and dense the sputum, the greater the resistance to dissolu- tion. Sulpauric acid produced black liquids like those con- taining chareoal, smelling strongly of muriatic acid; but. on dilution with water, they became clear. No precipitas Ato!» haacaze * Journal, Vol. XXV, p. 260. o st becrocel) tp Joumal, Vol XXV, p: 266. . into} tion 2s Action of ace< tous acid om pus. Comparative experiments con pus and mucus, with mineralacids, o mineral acids diluted, and vegetable acids, fixed alkalis end hime, strong solu- tions of alkalis, strong solu- tiuns of neus tral salts, OBSERVATIONS AND EXPERIMENTS ON PUS. tion occurred on dilution with water, and on saturation with the fixed alkalis, but a trifling sediment appeared, which redissolved on the addition of ue above acids. : 9, The mineral acids diluted, or added in small propor- tion, and the vegetable acids, coagulate variously pus and mucous fluids. Some become merely milky fluids, others eurdy fluids, others afford fibrous and leafy masses in a trans= parent liquor, and others give a uniform thick mass of curd. On standing the deposits are accerdingly of various forms, and the liquors above of various appearances; but I could discover no constant characteristic property of the subs stances by these experiments, as sume writers have asserted. 3. The solid fixed alkalis, or lime, mixed with expecto- rated mucus, occasion a strouger smell of ammonia than with pus; or than with muco-purulent sputum. Some use may be perhaps made of this easy experiment to judge of the nature of varieties of the fluids in question, particularly as far as depends on the proportion of ammonia; for some- times it cannot be perceived by the smell on mixing alkalis, but can by muriatic acid giving white vapotrs. Concen- trated liquid alkalis, added to both pus and mucus, dissolve them to produce clear liquids, except small curdy parts and motes. ‘These curdy parts and motes resist dissolution also for some time even in nitric acid, and seem to be self-coacu- lated lymph. They are in much greater proportion in pus than mucus. The addition of acids to these alkaline disso- lutions occasions precipitations: but no differences, or not with sufficient uniformity to afford criteria, were observed: according to the observations of other experimenters. 4. Concentrated aqueous_ solutions of various neutral salts, v2z. muriate of ammonia; nitrate of potash ; muriate of soda; sulphate of soda, &c.; being mixed in due quan- tity with pus of the kinds under examination, produce vis- cidity, like ropy expectorated matter, thickening like jelly, and less opacity. These changes have, in the case of muri« ate of ammonia, been called coagulation by Mr. Hunter; but by agitation in cold water the matters are diffused, and on standing, the pus is precipitated in its original state. I call these effects of the neutral salts inspissation, seemingly eceasioned by their attracting water from the pus; for noe such OBSERVATIONS ARD EXPERIMENTS ON PUS. o7 such change is, produced if either the purulent matter, or solution of salts, be diluted; nor is it produced if tie pus - be previously coagulated by caloric: also the inspissated pus is coagulable by caloric as usual. No such inspissation is produced by these salts in mucons sputum, or in muco~ purulent sputum, so that undoubtedly it is a criterion as discovered by Mr. Hunter in the case of muriate of ammo- pia, and with other neutral salts, as now manifested. 4, Lendeavoured to find some easy tests for distinguish- and other tests. ing pus from mucus; but I did not succeed with the tan- ning principles gallic acid; supersulphate of alumina; nitrate of silver, and other metallic salts; and as already said, varions acids. They all produced. precipitation, of these animal matters, but not with observable characteristic differences. 5. To observe the state in which ties matter of pus is se- State in which ereted, I procured the assistance of Mr. Maynard, the pre- ilaidaaayr ait sent house-surgeon of St. George’s hospital, and Mr, George Ewbank, who had been on many occasions essentially ser ” viceable in my inquiries. Square pieces of goldbeater’s skin were applied to various sore legs after carefully re- moving the matter already secreted. ‘In five or ten minutes the square pieces being removed, they were found wet with alimpid fluid, In this state they were inspected by the mi+ ‘crosccpe, by which numerous globules were seen. In ten minutes farther the liquid was ne longer impid but opaque, like pus, iu which the usual spherical particles were seen with the microscope as juft mentioned, ! Supposing objections might be offered on account of the alteration of texture of the skin employed, sauare pieces ‘of glass were aiso apphed. The results were the same in “both trials. The two gentlemen above named, as vvell as Dr. Richard Harrison, and other pupils, who happened to be present, all concurred in the observation, that the lim- | pid matter became opaque, and that while limpid it was, — : Tike pus, full of spherical particles. i { T 0 be concluded in our next.) 38 NEW ACID GAs. VV. Av, Account of a New Gas, with a Reply to Mr. Mourray’s last Observations on Orimuriatic Gas. By Mr, JOHN Davy. I To MR. NICHOLSON. SIR, Mir Davy’s Asour six months since Mr. Murray undertook te ene. oppose Mr. Davy’s theory respecting oximuriatic gas, and Murray. to defend the old hypothesis, in which this substance is considered as 2 compound of oxigen and an unknown basis called muriatic acid, and common muriatic acid oe as a compound of the same basis and water. His experi- Independent of his general reasoning, the only arguments a advanced by inis gentleman in support of his opinions were derived from his own experiments, undertaken expressly for the purpose. His first attempt to discover oxigen in oximuriatic gas was by trying the action of this substance on carbonic de and he concluded, that it did not exert any when the mixture of the two gasses, previously dried, was exposed to the influence of light. He then endeavoured to prove, that the addition of hidrogen to the mixture in- duced action, and the formation of carbonic acid gas. He also attempted to show that oximuriatic gas, if supplied i | sufficient quantity, 1s capable of affording oxigen to sulphur m@ sulphuretted hidrogen, and of converting it into sulphus reous or sulphuric acid. Obdjections. To account fur these supposed changes in 1 consequence of the presence of hidrogen, he was obliged to imagine, inop= position to all experimeatal evidences, that the composition of muriatic acid gas is indefinite: that the unknown basis combines with diferent proportions of water, but always retains the appearance and the gaseous state of common yauriatic acid gas, hitherto the only subject of experiment... _.. Having given this outline of Mr. Murray’s mode of de- . fence of the old hypothesis, I shall briefly state the facts J ventu red to oppose to it, Wiser present | it was first shown, that muriatic acid ‘gas, eae the sul- phuretted NEW ACID GAS. 39 phuretted liquor of Dr. Thomson, alone resulted from the in the experi action of dry oximuriatic gas on dry sulphuretted hidrogen ; ™°"* and that the production of sulphuric acid in Mr. Murray’s experiment was owing to his having admitted water. My brother, Mr. Davy, next discovered the existence of New com- a new gas made in the same way as the gas employed in poupes Mr. Murray's first experiments, in which he says he ob- tained carbonic acid, and possessed of the property of con- verting carbonic oxide into carbonic acid, it being a com- pound of oximuriatic gas and oxigen. | ' ‘Lastly, it appeared, that due allowance being made for Experimenta the difficulty of entirely excluding moisture, . pure oximu- show that oxi- muriatic gas, riatic gas is not capable of converting carbonic oxide into 4.0, not ack carbonic acid, when inflamed with a mixture of this ges and dify carbunie hidrogen. Thus, when 10 measures of carbonic ede were On<. subjected to the action of oximuriatic gas inflamed by an electric spark with hidrogen, only two imeasures disap- appeared, 8 measures of carbonic oxide remaining unaltered. A result perfectly satisfactory, I conceived, considering the minute quantity of the gasses operated upon, not altogether amounting to halfa cubic inch; and recollecting, that half a grain of water contains sufficient oxigen to acide about four cubic inches of carbonic oxide into Caren acid. Mr. Murray is of a different opinion. He considers, in Mr. Murray of his last communication, the disappearance of two measures 2 Contry opt of carbonic oxide, a demonstration, that oximuriatic yas is nae a compound of an unknown basis and oxigen. In the same paper, which is published in your Journal for June, he has given an account of the repetition of his experiment ‘on the mixed gasses, employing pure oximuriatic gas; ‘and he has arrived at the conclusion, “ that the Nay of carbonic acid is established beyond the possibility of doubt.” I shall state the manner in which he conducted the expe- timent, and the evidences which satisfied him of the pro- chiction of carbonic acid. He exposed to light a mixture consisting of one volume His experi. of carbonic oxide and of the same quantity of hidrogen ment in supe. with twice that quantity of oximuriatic gas. After 36 Bears shat of if. he added ammoniacal gas to complete saturation, and, finding oa most = oe Sacoppic oxide had disappeared, m and — eos, = ie 30 A new acid gas the cause ef his mistake. x Mr. Murray’s experiment repeated, - Presence of water sus- pected but not te be found. The gas exa- mined. Its properties, NEW ACID GAS. and that one of the ammoniaca! salts formed had the pro- perty of effervescing with dilute nitric acid; he, without any additional proofs, drew the conclusion just mentiosied, ** that the production of carbonic acid in this experiment <* was established beyond the possibility of doubt.” ~ I have now to announce the existence of a new acid gas, which operated in’ Mr. Murray’s experiment, without his knowledge of its presence, and was the cause of those phe- nomena, bahich he erroneously attribated to the formation of carbonic acid gas. Repeating this gentleman’s experiment on the exposure of the mixture of the three gasses to light, and detecting, after the addition of ammonia, no traces vot carbonic oxide 3 and perceiving, as he stated, an effervescence of the ammmo- niacal salt formed with nitric acid; | was induced to repéat also his experiment on the exposure of a mixture of carbo- nie oxide and oximuriatic gas to light without hidrogen. In this instance I obtained the sane result, a total condensation by ammonia without the slightest remains of carbonic oxide. So satisfactory were the details of Mr. Murtay’s expe- riment, the result of which was asserted to be, * that dry carbonic oxide gas and oximuriatic gas do not act on each other ;”’ that at tirst I couid hardly believe, but that water was somewhere concealed in the apparatus, and | gave’ my-_ self much trouble to discover its source, but in vain. ~ The next step I took was to examine the gas, that re- sulted from the now evident action of oximuriati¢ gas on carbonic oxide. Mr. Brande was present at the time. Finding that it did not fume when thrown into the at- mosphere, that it had a most intolerable sufrocating odour, that it was colourless, that it did not act on the mercury, and that water absorbed it very slowly, we immediately perceived, that it was a new and peculiar compound of carbonic oxide and oximuriatie gas, and this conclusion is fully confirmed by the investigation [ have made of its proper ties. * I shal! now mention only the most striking circumstances “respecting it. It is my intention to give a full account of the experiments I have made on it, ina paper which 1 shall soon do myself the honour of offering to the Royal Society. I have NEW ACID GAS. - eI have found, that it is. produced i ry) two or three Ny ey when a mixture of equal volumes of carbonic oxide and ox- imuriatic gas is exposed in a tube over dry mercury to bright. sunshine ; and..that the condensation, that takes place in their union, ‘is exactly equal to one volume, so that this is the heaviest gas kuown excepting silicated fluoric acid gas. TI have also ascertained, that it may be at any time formed without the direct rays of the sun—Light alone being necessary. Its acid character is well defined. It reddens litmus and combines with ammonia; and its saturating power is so great, that it condenses four times its volume of this gas, forming a perfectly neutral salt, deliquescent, and of course very soluble in water; and its attraction for the dry volatile alkali is so strong, ‘that it decomposes carbonate of ammonia, and is not expelled by acetic acid from this alkali. The decomposition of this ammoniacal salt with effervescence by dilute nitric acid deceived Mr. Murray... Water in this instance is decom- posed, its hidrogen is abstracted by the oximuriatic acid to form muriatic acid, and its oxigen by the carboxic oxide to produce carbonic acid, which is disengaged. This will appear evident, when it is known, that the new gas neither inflames on the passage of the electric spark with either oxigen or hidrogen alone, but that it detonates violently with a mixture of oxigen and hidrogen in proper propor- tions, and affords only muriatic and carbonic acid gas. The action too of several metals and their oxides on this gas is perfectly consistent with, indeed is quite demonstrative of its being a compound of equal volumes of carbonic oxide and oximuriatic gas, so condensed as to occupy half the space of the mixture of the two. Thus tin, zinc, and an- timony, respectively heated in itin small bent glass tubes over mercury rapidly decompose it. In each instance cars bonic oxide, exactly equal to the volume of the gas decom- posed, is berated, and a compound of the metal employed and oxignuriatic gas is produced, the same precisely as ig formed ‘by the combustion of the metal in oximuriatic gas. \The decomposition too is just as readily effected by the oxides of zinc and antimony 5 with the first carbonic acid gas is obtained, and a compound of zinc and) oximuriatic gas; 8 Its produc- tion, Its characters as am acid, Decompos- tion of its am-= moniacal sait. Other propers. ties of it. Action of me- tals on it, It is compose NEW AcID Gas. gas; ; but with the last, the fusible protoxide Sten used, butter of antunony is produced, and carbonic Bes, libee rated, and an infusible peroxide formed, a proof, if any was d¢ of two acidiiy- ing principles required, of the formation of carbonic acid in the preceding instance being owing to the decomposition of the oxide of zinc, and not eh the oximuriatic gas. ‘These are some of the principal circumstances I have dis- covered respecting this new gas; a gas, which, as it red- united toone dens litmus and expels acids from ammonia in consequence base. No carbonic acid formed rom the come of superior attraction, has every claim to be cousidered as a peculiar acid singularly composed of two acidifying prin= epics united to one inflammable base, After the preceding statement of facts, Mr. Murray, I should conceive, will be induced to renounce his conclusion, “that the production of carbonic acid in his experiment was established beyond the possibility of doubt;” and admit, that what he considered as carbanic acid was ace tually the new gas just described; aad I should likewise imagine, that this gentleman in future will be more caue tious in his assertions, and criticisms on the labours of others. Let the intelligent candid readet judge of the pro- priety of the following observation. Mr. Murray says, having previously stated, that he had found carbonic acid in all his experiments, ‘‘ that the Messrs. Davys did not obtain it in theirs, because they did not look fer it with sufficient care, or were not sufficiently aware of the falla- cies, by which its production might be concealed.” His considering the new gas as carbonic acid is-another instance _ of the evil tendency of attachment to hypothesis. How just is the remark of Lord Bacon! quod mavult i home esse ve- rum, id facile credit. In a former communication I have observed, that no car- - bonic acid appeared to be formed, when dry carburetted ustion of dry hidrogen and oximuriatic gas are inflamed by the electric -burettéd hi, gen and imuriatic Se tn assigning as a reason for this belief, the precipitation ~of charcoal. I tried both olefiant gas and carburetted hidrogen procured by the decomposition of acetate of pote “ash by heat. Mr. Murray says, that he has repeated the a pen Sto Ne Neato in a coal experiment, and that in this too I was deceived. Mr..Mur- ray employed the gas produced by heat from moistened _chargoal, Si Geek S32 ‘ sali WHITE FOR WATER COLOURS. 33 be eis surprising that he ‘is not ‘aware, ‘that Dr. ; © The $8 Cirrus de ecribed, Its formation. ery lofty. THE NATURAL BISTORY OF CLOUDS. The ee ee A dense cloud, spreading out intoa crowa of cirrus, and passing beneath into a shower. Of ihe Cirrus. This is always the least dense, and tomeucale the most elevated modification. It is sometimes spread horizontally through a vast extent of atmosphere ; the whole breadta of the sky being insufficient to show where it terminates. In this case, its parallel bars appear, by an optical deception, to converge in opposite points of the horizon. At others, it is exhibited in unconnected perpendicular bundles, of the most_ minute size. Between these extremes, it may be traced in every degree of extent and inclination to the horizon, In a. serene sky the cirrus ds first indicated by a few threads, pen- cilled in white, on the azure ground. Its ingrease takes place in various ways, and. may be compared sometimes to vegetation, more often to crystallization. Thas, I. Parallel threads are ad, ray to gach other horizontally, and occaston= ally other strata of the same, crossing the first at: right or oblique angles, unuil a-delicate transparent veil is fermed. 2. Parallel threads are collected into distinct groups, Jying. at various angles with the horizon. 3. Flexuous and di- verging fibres are extended from the original stem, forming the resemblancé of crests of feathers, locks of hatr, &e. 4, The first formed threads, become, as it were, the sup- ports from which others « bliquely ascend o» descend into the atmosphere. Lastly, A dense nucleus is sometimes, formed, and short fibres shoot owt fyom it in all directions.» The great elevation of the cirrus has been ascer ained by geometrical obseryations. ‘*The small white streaks of. commenced vapour, which appear on the f ce of the sky, I have found,” says Dalton, “ by several careful observations, | to be from three to five miles above the Earth’s surface.’””’ Viewed from the summit the highest mountains, they appeer as distant as from the plains. A more easy and not less convincing proof of their elevation may be deduced. from their continuing to be ti ged by the sun’s rays.o the, evening twilight with the more vivid co curs of the prism, while the denser clouds, having already passed eee the same gradation, are in the deepest shade, The THE NATURAL HISTORY OF CLOUDS. 39 The duration of this cloud varies according to its staton Its duration. ‘jn the atmosphere, and the presence or absence of other clouds: it is long, ‘extending sometimes to thirty-six hours, when it appears alone, and at its greatest elevation; but shorter, or even yery transient, when formed lower, aud in _ the vicinity ef the cumulus, : , By an inexperienced observer the cirrus would be pro- [ts motion. nounced absolutely motionless. On comparison with a fixed object, howeyer, it is sometimes found to have a consider- able progressive motion. ‘The propagation of the cirrus, tts connexion and the variable directions of its flexures, merit attentive with the wind, observation, as being intimately connected with the varias. tions of the wind, slaiaisioly undoubtedly nat produced ee the mere motion of the air, The general principles, which the imperfect ones hi= therto bestowed on it seems to point out, are the following + ' 4. Its appearance is a general indication of winds and Indications ‘from it. t it is most conspicuous and abundant before storms. 9. It is often a leeward cloud; or, when a group of cirri appears on the horizon, it seems to invite a current towards it: and the wind very often shifts into that quarter towards which the points are directed, My. 3. Horizoutal sheets of the cirrys, more particularly those which carry streamers pointing upward, dre among the in- dications of rain approaching, while the fringe-like depend- ing ones are found to precede fair weather, % mT Of the pews ‘Clouds in this modification are commonly of dense , Cumplus de- structure. They are formed in the lower atmosphere; and “cided. move with the wind, or more properly with that current which flows next the Earth. ‘The phenomena of the cumu- lus ta sually these: In the latter part of a clear morning, je, formation. a small irregular spot appears suddenly at a moderate ele- _ vation. Thisis the nucleus, or commencement of the cloud, the upper part of which soon becomes convex and well de- fined, while the lower continues irregularly plane. Oo the -eonvex surface the increase visibly takes place, one heap or - protuberance succeeding another, and again losing itself jna subsequent one, uti! 9 pile of cloud of an irregular » HH - hemispherical 40 Decrease, Jadication. Stratus de scribed. Jndication, THE NATURAL HISTORY OF CLOUDS. hemispherical form is raised; which floats aleng, presenting its apex to the zenith, while the base, or rather the lower - surface of the’ baseless fabric, continues parallel to the horizon. yo When these clouds: are of considerable magnitude, they, remain at proportionably great distances; When smaller, .. they croud the sky by a.nearer approach to each other. In each cage the bases range in the same plane; and the increase of each keeps pace with that of its neighbour, the inter- vening space remaining clear, The cumulus often arrives atiits greatest magnitude early. in the afternoon, when the temperature of the day i is at its maximum... Ag the sun declines, it gradually decreases, ree taining its character till towards sun-set, when it is more or less hastily “broken up, and evaporates, leaving the sky clear, as in the early part ofthe morning. Its tints are often vivid, and pass through the most pleasing gradation suring this. Jast hour of its existe: nee. i a The preceding phenomena form the history of the pure cumulus, as it may be termed, when no other modification appears along with it. They are both the accompaniments im prognostics of the fairest weather. Of the Stratus. The stratus has a moderate degree of density. It is the. lowest of the modifications, being formed in contact with the earth or water. It comprehends those level creeping mists, _ which, in calm evenings, spread like an inundation from the _ valleys, lakes, and rivers, tothe higher ground. a Unlike the cumulus, which belongs to the day, and rarely survives the setting sun, this aoe accompantes the shades of night, and commonly vanishes before the ascen ing Tumimary, The evaporation commences from below. At the moment of the separation of the stratus from the Earth, its character is changed, and it puts on the appearance of | the nascent cumulus. The nocturnal visits of the stratus have been always held a presage of fair weather. Thus Virgil: “* At nebulz magis ima petunt, campoque recited? Then mists the hills forsake and shroud the plain. = 7" THE NATURAL HISTORY OF CLOUDS. 4y - The meteorological axioms of this great poet were proe bably selected from the popular ones of his age, as confirmed by his own experience. Hence they ever agree with that of his readers, There are few days in the whole year more calm and serene than those the morning of which break out through the stratus. They are the haleyon days of our aus tumn: an interval of repose between the équinoctial gales and the storms. ~ winter. Of the Cirro-cumulus. The intermediate nature of ‘this cloud may be ascertained Cirro-cumulug - by tracing its origin, as well as inferred from its structure, 2scribed- The cirrus, in its slow descent through the air, may be seen to pass into this and the next modification ;. although its previous appearance does not seem absolutely necessary -to the production of either. Most of our readers will recollect the appearance of the icy efflorescences on the panes of windows, graduall y melting. into an assemblage of ‘drops, which adhere to the glass, res taining somewhat of the same figure, deprived of its right lines and angles. Such is the change of form which the cirrus undergoes, in passing to the state of the cirro-cumulus,) . And, as the water on the windows is occasionally converted _again into spicule of ice, so these small rounded masses sometimes suddenly resume the forms of the cirrus. In the oblique denser tufts of the latter, the change to the spheroidal form often begins at one extremity, and proceeds gradually” to the other, during which the cloud resembles a ball of flax, with an end left unwound and flying out. All the cirri in the same group, and frequently all those in view, observe the same law in these changes. The cirro-cumulus forms a very beautiful sky. Numee - rous distinct beds are sometimes seen floating at different al- titudes, which appear to consist of smaller and still smaller clouds, as the eye traces them into the blue expanse. It is Indicationsy most frequent in summer;, is the natural harbinger of in- creased temperature; and, consequently, one of the best. indications of fair weather, when-permanent or frequently repeated. A more transient display of it is, however, fre- queot in the interval of warmshowers, and in winter. There ' are 4g Girea stratus described, fadications, FRE NATURAL HISTORY OF CLOUBS. are alse certain forms of it, more deep and dense than ors dinary, and arranged on a curved base, which enter into the. peeuhar features of thunder-storm. itis usually found to accord with a rising barometer, ‘ Of the Cirro-stratus. This is a multiform cloud, and can only be detected in its various appearances by an attention to jts distinctive cha racters, Itis always.an attenuated sheet, or patch, floating en the air, ina position nearly,or quite horizontal, As we haye compared the cirrus to dry flax, we hoes el consider it as drenched ia water, and haviny its spreading fibres res, duced to acloser and recumbent form. V lewed over head, it is remarkable for its uniform hazy continuity, and in the horizon for its great appearance of density, the consequence of its being seen edgenigee In this situation, also, if some- times cuts the sun’s or moon’s disk ACTORS. with a dark line; of which Virgil, var $* [lle ubi nascentem maculis variaverit ortum Conditus in nubem, medioque refugerit arbe, Suspecti tbr. sint imbres; namque urget ab alte chactnncynies: wait notus, pecorique sinister.” Georgic, lib. i, Or should his rising orb distorted shine Through spots, or fast behind a cloud’s dark line Retire eclipsed; then let the swain prepare ried For rainy torrents: a tempestuous air, . +> Swift from the southern deep, comes fraught | with ill, 7 he corn and fruits to waste, the flocks to chill. ~'¥he cirrosstratus is the natural indication of depression of ¢emperature, wind, and rain. In order to make a proper use of it in this respect, it is necessary to attend to the time of its” appearance, to its continuance, and its accompaniments,’ This cloud sometimes alternates with the cirro-cumulus, ’ ' either at different intervals of the day, or in the same sky, or eyen in the same stratum, which may consequently be seen - successively in each modification, and at intervals, partly in ape, partly in the other, In this case the prognostic ig. - doubtful, ‘ THE NATURAL HISTORY OF CLOUDS. doubtful, and ng is to be had to that which ultimately prevails. Again, there is a transient appearance of the cirro-stratus, which often accompanies the production of dew in the even- ing, and denotes an atmosphere but lightly surcharged with vapour. Notso whenit appears earlier in theday, or at sun-rise (according to the preceding quotation), and attended with the rudiments of ‘the cumulus. In general, the weather may be suspected of a strong tendency to wind and rain, as often as the sky is both hazy, and deformed with numerons ‘small patches of cloud, in win@etic extenuated character predominates} and these appeerances, together with -an abundance of cirro-cumulus, indicate ender? Before storms of wind, there is in particular a feature of cirro= stratus, often very slightly expressed, and in one quarter only, which resembles the architectural cy ma. ~ Bat the most formidable appearance of the cirro-stratus is that of extensive sheets, descending from the highest re- ‘gions of the atmosphere, 2 and scarcely discernible for a time, but by the prismatic colours which they assume in the vi- cinity of the sun’s or moon’s place. These are the skreens 43 en whieh are described the immense circles of haloes, form- Haloes, pam ing, by their occasienal antersectious, parhelia, and parase- lenia, mock suus and moons, which sometimes vie in splen- dovr with:the luminaries themselves. It is easy for those who are acquainted with the principles of optics, to conceive how these intersecting circles are produced by light passing thtiough’shects of cloud placed at different ners and an- gles. - Consistent»with this is: the prognostic of foul weather com- monly deduced from the appearance of the halo. After a solar halo in spring, ior the early part of sainmer, a series of wet and coid: weather may be expected, although it should net commence for some days; during which, nevertheless, the same staie of the atmosphere subsists, as is often mani fest fror sfbe repetition of the halo. Those winch surround | the m< clear nights indicate rain or snow, according to theseason of the year. _ dn mountaineus and even hilly countries, the cirro-stratus ie Seequent seen adhering to the more eleyated points of b 3 be helia, &c. Cumulo-stra« tus and its for. mation de. seribed, THE NATURAL HISTORY OF CLOUDS. land. In winter it also visits the plaing, in the form of & very wet and durable mist, the drops of which aye neverthe- less too sreall to be visible, and which, unlike the stratus, is mare dense on rising grounds than in the valleys. The cirro-stratus five ale acegrds with a sinking state of the barometer. Of the Cumulo-stratus. ; ; The formation of the cirro-cumulus, or cirro-stratus, by condensed vapour, descending from the higher atmosphere, doves not prevent the cumulus from being produced out. of. the water, which, in the mean time, evaporates from the Earth, und ascends to the middle region. In this case, the two modifications after a while come into contact, and pre- sent ta the attentive observer aguccession of curious appear~ i ances. While the cumulus is rapidly increasing ‘ipictbeel! a deli- cate fleece, of a structure visibly di t, sometimes at- tuches itself to its summit, where it a as on a-moune tain. his fleece is a cirro-stratus 3 and the materials of which it is formed are brought by a superior current over- taking or meeting the cumulus. Frequently, the cumulus in its increase breaks through the cirro-stratus, and appears again above it, but with a visible change in the aggregation, which now becomes rocky, perpendicular, and, finally, over= hanging. If the cirro-stratus fhould itself increase too fast to be swallowed up by the cumulus, the latter after a while extends its protuberances laterally, and attaches itself by’ them tothe superior mass of cloud. When the cirro-cumulus, in hke manner, occupies the superior place, a cumulus rising beneath it is susceptible of the same union by mutual attraction; the result of which, as in the former case, is a large, lofty, and dense cloud, which often subsists through the day; and in the evening uudergoes the usual evaporation. “ It is not, however, absolutely necessary to the production ‘ff this cloud, that either of the superior modificati should be previously formed. In a favourable state of the atmos- phere, the cumulus itself, after having arrived at a certain nagnitude, suddenly begins to evergrow its base, and pro- 9? duces ay TNE NATURAL HISTORY OF CLOUDS. 4S duces'a cloud, whigh, in regard to both its form and its rapid growth, may be compared to a mushroom. The cumulo-stratus usually prevails in the completely overcast sky. In this it presents appearances not easy to be described, but which may be classed by a due attention to the theory of this cloud, At present it is intended to com= prehend under it every mode of union between different ftrata, which is not productive of rain, Future investiga- tion may point out distinctions, which at slik we are not Bicyiored to make. This modification is most frequent during a mean elevation Indications. of the barometer, or that which is denominated changeable, when the wind lowe from the west, with occasional deviae. tions towards the north and soath. In respect to temperas | ture, it has a wide range, aed may usher in a fall of snow, as well as a thunder-storm. Of the latter, indeed, it is amorg the regular harbingers, but with peculiar appearances. During the suffoca Paes which prevails before the first discharge of the eee electricity, it may be seen in different points of the horizon, rapidly swelling to a stupen~ dous magnitude, most curiously wreathed and curled, fretted and embossed” in its substance, and flanked at dif» “ferent heights by the delicate opake streaks of the cirro-stra- tus. The whole presents a spectacle of peculiar magnifi-, cence, in contemplating which one may imagine an invisible agent collecting in this i immense Jaboratory the energies of po storm, and arranging innumerable batteries for the sub- sequent explosions. It will appear by what we have already stated, that the cumulo-stratus affords in general a doubtful prognostic. When it is formed in the~ morning, the day often proves fair, though overcast ; and if the eis See has contri- buted to its formation, there will probably ensue heavy showers on the second or third day. When it subsists a long “time, the character of its superior spreading part may be consulted, which, if it be decidedly either that of the cirro- % stratus, cor cir o-cumulus, the usual result of their appear- ance may be expected. Sta de Of the Nimbus. adi “To have a correct notion of this cloud, the reader has only yrimbus de- te = 46 acribed, THE NATURAL HISTORY OF CLOUDS.” to take the opportunity of examining a shower in profile ag it approaches from the horizon. He will see the dense gloom, which experience teaches him to regard as amass of descending rain, losing itself above in a cloud, which com= monly spreads in one continuous sheet toa great distance all atound the shower; insomuch that while the latter is on the horizon at several miles distance, the edge of the cloud has frequently arrived in the zenith. He will perceive, that this spreading crown of the shower advances regularly before it, and that, whether viewed from a distance or ovef-head, it exhibits in a greater or less degree the fibrous structure of the cirrus. After the shower has passed over, he will ‘coms . monly observe the sume appearanees in the part of the cloud which follows it; and in squally weather he will sometimes be able to repeat these observations on many different showers appearing successively ; or at the same time, in dif» ferent quarters. The term nimbus is intended strictly todes note no more thar this‘ verted cone of cloud, from which a sudden or dense local: .ower, whether oft rain, snow, or hail, for the difference is not essential in either case, is seen to descend. As it rises to a great height in the atmosphere, it may be seen from a distance of many miles ; and se constant is the result of a shower arriving with it, that though, m @ few instances, perhaps from the small quantity of the rain, we have not been able to discover the usual obscurity bes heath it, while at a distance, we believe it may be laid down as a yeneral rule, on as good grounds as in niost othercases, that rain, snow, or hail, is falling on the tract over which it is spread. “¢ Qualis ubi ad tetras abrupto sidere nimbus It mare per medium, misers heu prescia longé Horrescunt corda avricolis.” Virgil. So while far off at sea the storm-cloud lowers, And on the darken’d. wave its fury pours, - Mid crops unreap’d the hapless peasants stand, And shuddering view its rapid course to land. There is a great differences at different times, in the: pro- portion which the jnverted cone of cloud bears to the column ef rain, &c., in which. it terminates; and in a very turbid and moist THE NATURAL HiSTORY OF CLOUDS: fnoist Atmospheré, the character of the upper part often apa proaches more néarly to the cifro-stratus than the citrits; & more perfectly distinct and local the shower, and the clearer the rest-of the ait from other clouds, the more pers fect the crown of cirrus, which, indeed, sometimes assumes 4a almost geometrical precision in its form and. intenal structure; the threads of the cirrus tending from all sides directly towards the top of the column. af The pure nimbus commonly moves with the sind and Increased b¥ from the rapidity of its passage affords but little to the rains TRU gauge. But it often happens, that it is formed in the midst of cumuli, which have already arrived at a great size. In this case the latter may be seen, to enter successively into the focus at the top of the column, whence they never éimerge ; being visibly converted to the purpose of supply= ing materials for the irrigation, which thus becomes more abundant ; and the shower js also occasionally thus propa< pated in a direction opposite to the wind. The nimbus, moreover, does not always originate in a Changes, tirrus. The cumulus, and more often the cumulosstratus, may be seen to expand at their summit into a cirrose sheet, While the lower part is resolved into rain. On the contrary, the rain suddenly ceasing; and the nimbus remaining entire, the sharp extremities of ‘the crown often retire into it ; the Sides assume the swelling folds, and the character is ex changed for that of PE a When the shower has expanded itself, and the sheets break, the superior portions asually turn to the cirro-cumulus or cirro-stratus, and the “Tower to the cumulus. When a total evaporation of the re- Indications: maining cloud follows a shower, it is a very favourable prog= hostic. A nimbus is frequently accompanied by a cirro= Stratus or two lying near it, and on a level with the densest part of the cloud. The nimbus of thunder-storms has many ef these, as before observed of the cumulo-stratus, arranged at different heights; which, with the grotesque form of each loud, and’ the hazy state of the medium, are sufficiently dhitactcristic of the high ‘electric state of the air at such times, ‘and want only an attentive perusal (in nature) to en ble the observer to ascertain it on future occasions, It ape pears, that the cumulosstratus passes to the nimabus by a a sudden 48 @rigin of clouds. Evaporation. Vapour, The air hasno solvent action en itt - “ Laws of the natural pro» cess, . THE NATURAL HISTORY OF CLOUDS. sudden change in its electricity : for in tracing the progress of a thunder-storm, through a long range of these clouds in the horizon, we have been cathode” that the clouds, which had ceased to afford explosive discharges, had undergone this change in their superior part, and were pouring down rain ; while others, among which the hghtning stili played, or which were situate beyond it, retained their swelling and rounded torms some time longer. Of the Origin, Suspension, and Destruction of Clouds. These aggregates consist of water, raised by evaporation, and become visible by condensation in the atmospheré. Respecting evaporation, and the state in which vapour sub- sists, there has been much diversity of opinion: and, of the several theories proposed, there is not oue comprehensive enough to merit exelusive adoption. A number of general principles, however, have been established ; which we shall employ, with the aid of those of electricity (hitherto not enough considered in its silent and gradual effects), to ex- plain, though in an a ea manne the principal pheno- mena of clouds. Evaporation consists in the union of water ath, caloric, and the escape of the compound as an invisible fluid, which we shall exclusively denominate vapour. : The solvent action of the air, to which this effect has been attributed by chemical philosophers in general, has been proved by comparative experiments on the force. of vapour in air, and with air excluded, to have no perceptible share in it. The laws which govern the natural process, for these — alone here interest us, may be thus briefly stated. . The force by which water is cenverted into vapour is directly as its temperature, other thiugs being equal: but this force has to overcome an opposing one, of the same nature, in- _ herent id the vapour which already exists in the atmosphere. ” For. such vapour, by its elastic property, tends to exclude from the space it occupies every additicnal portion; and consequently to prevent the escape from the water of new vapour. Hence the temperatures being equal, the quantity of vapour produced will be less, the Brereet: the quantity alteady di ffused ip the aire THE NATURAL HISTORY OF CLOUDS. 49 But, though thefchemical action of air is imperceptible, Mechasieaiice. its mechanical, efet 3 is great. A moving atmosphere may fctofair on - double or triple the rate of evaporation, according to its ye- evaporations locity. For not only is the surface, from which only the vapour escapes, thus enlarged and changed; but the nas- ‘cent vapour itself, which would otherwise hover a while upon it, to the obstruction of the process, is immediately brushed away and diffused. By. applying these principles, we may. explain to ourselves Explanation,of various natural phenomena: as for instance; why the wind, various pheno- after rain, becomes colder than even the rain which fell ; oie being robbed of its caloric by the evaporation of the floating and deposited water, with which it is in contact: why snow _sdmetimes totally disappears without melting, and the sur- + face of ice becomes sensibly wasted and channelled; for these are warm, compared with, the dry and frosty air. aa blows at such times, and consequently evaporate freely. In what manner, again, a strong westerly wind in summer or autumn brings up oye which-on its cessation descend in - ain: for it a ruinel aporation by its mechanical effect, and jthe vapour escapes into an atmosphere already too moist to carry it off to any great distance. This will be evident by recurring to the principle before stated, that the vapour. escapes by the force of the temperature of the water out of which it is formed ; and, consequently, into a colder atmosphere, it will yaaa incl though continually decom- rirosedt thereby. - Vapour is, decom posed by air, in. ‘consequence of the su- Decomposi« ae affinity of the latter to caloric. This happens in two tion of Vapour. ways. 1. When vapour es¢apes or is propelled into air — \ colder. than, itself; the result being a local dense cloud. @. q When.a mixture of air and vapour is cooled; in which case there ensues,a general turbiness, which we shall, exclusively denominate haze. Itis occasioned by minute floating par- ‘Haze. : ticles” of water; the caloric which, united to these, formed transparent. yapour,, having, passed into the.air. Out of this haze clouds may be afterwards formed, by _ simple aggregation, or by electrical attraction. It abounds w ‘im the atmosphere, during the most part, of the year, occupy~ ing sometimes the higher, sometimes the lower, part, thereof. “oVoi. XXX.—SeEp?. 1811. E The 4 fon \ 50 Nature of thé | ° strats. “$#E NATURAL HISTORY OF CLOUDS. a i ; : a , ; The quantity in which it exists may be judged of, ‘at éome periods, by the appearance of distant objects seen’ horizon- tally: at others, by the degree of intensity of the’ blue ‘colour of the sky, whith beconies paler by it, if indeed the blueness is not wholly due to this part of the erie Of the Nature of the Stratus. “> This cloud is an example of the decomposition ‘of vapotir thrown into air of a lower temperature. The earth or wa- ter on which it ae is always warmer than the cloud, as is also the clear air above. Thus, in a stratus, formed over a field with ponds, the temperature of the earth just below the turf was 57°; of the water, 59°; of the air, at-an eleva- _ tion of thirty feet, 55°; while that of the cloud, at four feet from the ground, was 49°5°.. Hence this cloud presetvés a level surface; and hence it uniformly vanishes, or Begins to "be driven upward, as soon as its tefnperature bebedies! equal to that of the earth. It is consequently die to the decom- position (in a small portion of the ‘atmospher e) of the va- pour which the earth and watercontinue to émit, aftersun- - Set, by the force of a teniperature previously acquired. But ‘the change i in the lowér air, which gives occasion to this lo- cal decomposition, is not SO easily be explained : for it‘ap- : pears that very often, in the evening ofa clear day, the de- crease of temperature in the a de pHLVe takes place'in the same order in which the increase did in the eae 3 viz. - beginning from the surface of the earth and proceeding” up- _ward. If the air never became colder, 6n these occasions; than the ¢ tiguous soil, the effect might very well be as- _ cribed to the absorption ofa quantity of calorie by the lat- ter... But we see that, i in the presen’ instance it became colder by seven degrees, though vapour was still decom/pbs- ing: and this1 in. a perfect calm, which, in a great degree, forbids another | Suppesition, of the exchange of a quantity - of heated air below, for as much cold air from the higher at- _ Clouds not go good condue- tors as supe: posed, : *.. mosphere , otherwise this would stem a sufficient account of — the matter. The electric charge. of the. guste which 18° ‘always posi- tive, and. sometimes highly s0, notwithstanding the contact of its lower surface with the earth, seems to sive? that a ~ , cloud THE NATURAL HIsTORY OF CLOUDS. $1 @ioud js not even so good a conductor as has been supposed; and that the fluid,, in certain. cases, may be very gradually transmitted through it, Positive electricity being that pro= per to the atmosphere in fair weather, we should naturally expect to- find itin this cloud. — It might be worth while to examine. the air above; with a _ ¥iew to discover whether there exists in the latter a negative _ counter-charge. It will appear, from a consideration of the prin pigplees before stated, why this cloud is almost peculiar to . the autumn. The gradual decline of the sun, at this season, ‘ A Keeps which is ultimately disposed of in rain; and hence follow the atmo Aidit constantly surcharged with vapour; gales of wuid. 7 he stratus, therefore, though an immedi- Indications. rate indication dnd \accompaniment of fair weather, affords an, unfayourable prognostic inthe early. part of suminer; as it shows that a tendency has already begun to extensive pre- — cipitation, at a time when the usual predominant feature is increasing dryness. ) Se i Of the Nature of the Cumulus. ise fa ot 4 -. The heating effect of the sun’s rays on the atmosphere is Nature of the or eatest near the surfal Pot the E , and diminishes gradu- cumulus. eallly i in ascending. The Gieranen proceeds in fair either eat the rate of about one degree for each hundred yards, as as vappearsiby observations with the thermometer on stations of bon known difference in altitude. cm: gL his inequi ity appears - to a. to the cumulus, on _» the same principles as those of the stratus, but the effects are _more complicated... Vapour is generated, a8 before, at the , ouslodeah the Earth, but it is thrown into an atmosphere _ cheated by the sun. Here it maintains its elastic state, and, ..in proportion to the supply from below, the whole pe ny existing in the atmosphere is compelled torise, Tn doing _ this, it changes its climate, and arrives among air of a lower a temperature, where a portion is continually decomposed, filling the middle region with haze. Of this, small agere- gates begin to be formed, the increase of which.is at first ’ s determined by no partiealar law. But the aggregate is not s Brae. n EQ? me . mt) equilibrium with the air. it tends to subside, and in the 52 | SHE NATURAL HISTORY oF CLOUDS. Nature of the méan time the increase of temperature is proceeding upward, cumulus. ‘Hence the lower part soon finds a position in a plane of air stficiently warm to evaporate it: and as this effect is regue lated, in general, by the elevation alone, we see these age gregates assume each a flat base, resting as it were on the same plane, parallel 'to the Earth’s surface. The remainder of the cloud ‘sports ‘in all the vaneties of the spheroid, and more rarely of ‘the ‘cone; according to the course of the ; showers of minute particles of water, which we may consider (though invisible in ‘their progress) as descending upon it. The vapour generated ‘at the base is, probably, in part con- dénsed@n the surface of the colder particles of the cloud above. While the supply from the haze exceeds the waste by evaporation, the cloud iticreases ; when the latter has be- ‘gun to prevail, it may be traved through various stages of diminutidn to its final wreck, on sinking wholly into the warmer atmosphere. This happens commonly about sun- ‘set ; because the ascending current of vapour, the source of the phenomenon, then slackens or ceases; and the lower air parting with its redundant caloric to the higher, we un- expectedly see the dense clouds evaporate, at the very time wheo the chill of the evening is dg below, and the dew falls. i ds ‘But it does not appear, that the causes we have hitherto ‘enumerated are fully adequate to the phenomenon. The jucrease of the cumulus is often more rapid ‘tha consists with the notion of simpjgenttraction, exercised between dis- ‘tant particles of water, in a resisting mediim. When a cumulus is thus increasing, the small aggregates in its way ‘do not usually join it, but'seem to, vanish before it. Lastly, the cumulus itself, However dense, never descends in rain. Itis difficult to conceive, that'so pdwerful‘dn attraction could ‘exist for many hours, without bringing the (particles toge- ‘ther into larger and lar : drops, until they were too heavy for longer suspension. Wve suppose, however, that, from _the commencement of its aggregation, the cumulus becomes a positively electrified mass, these’ difficulties vanish. This mass may electrify negatively, and attract into itself, from great distances, both the pal particles of water and those which have already united in much, smaller masses. : : , Its fy THE NATURAL HISTORY OF CLOUDS. ‘53 Its. pe articles rust be a BA repulsive, and cannot come into contaet without a change of state: the same may be said of the respective clouds in this modification, when they do not differ too much i in surface. “u Of the Nature of the Cirro-stratus. ce Mae “When a portion of the atmosphere, charged with vapour, Nature of the is brought over a tract of land of lower temperature than it- cure-stratus. self, its caloric is abstracted in sufficient quantity, usually te occasion a decomposition of some of the “apo and a ieniittin Ante general turbidness. ; Wet The sweating, as it, is ‘im properly” called, of walls and Dampness on ‘pavements in a thaw, and when rain is about to come on, is ¥#!'s &c. ‘from this cause; the vapour being decomposed on their sur- faces. The mist which ensues at these times obscures dis- Mist. tant objects, and occasions the trees, against which it is borne by the wind, to drip plentifully. It isin fact a cirro-stratus in contact with the Earth, and no phenomenon is more fami- ‘Wat to the inhabitants of hilly tracts. The same general de- "pression of temperature may happen in another) way, and higher in the atmosphere. Whena cold and moist air flows over a warmer vaporous one, it is obvious, that the former “may be warmed, and become more transparent, at the exe "pense | he latter; which, from the same cause, must be- eome turbid. The haze thus produced will not subside with the uniform motion of dew, but rather i ip sheets, hecoming " more dense asttliey descend; both from the approximation of aa articles, and addition from the vapouges meet iS But the cirro-stratus is far from assuming always the simple “Hit; téWhich the mere éffects of gravity might be supposed ‘to give tise.’ It exhibits changes, which can only be attri- buted to the acquisition, or passage thr it, of such small portions of electricity, as in a humid medium we may con- ‘ceive a cloud to be susceptible of. On these occasions it tends either to the state of cirrus, or that of cirro-cumulus, of which we shall treat presently, ‘The reason of the pr tic afforded by the cirro-stratus Indications. ‘will now be evident. *... us notice of achange in the _ state of the superior atmosphere, which we could not other- ‘f : wise s ae 5& THE helena HISTORY OF CLOUDS. wise be certain of, until the current, in ith course of propa- gation downward, had begun to affect the denser clouds, thrown up by the superficial, evaporation. It is not very . | uncommon to see the cirrosstratus evidently brought~ by a | wind, moving in a different direction from that “ig the | cumuli are immersed on which jt settles. In this c se the latter are speedily arrested by it, and assume the new course, : or. descend i in rain, by a change of their electricity. mae Of the Nature of the Cirro-cumulus. Nature of the tu now reverse. the former case, and consider the? eT aan current as both vaporized, and warmer than Se air below. - It is probable, ‘that the up ris then cooled by that part of the lower which is next to it, though very slowly, from the difficult transmission of caloric downward. . The decom position: of the vapour in the upper current by this means may give origin to the cirro-cuimulus ; and the peculiar age . gregation-of this cloud, as distinguishab from that of the cirro-stratus, may be the result of ifs acquiring electricity © in its descent in a much eater emg Such, at least, ig - the inference we may deduce from its abundange before thunder storms; when it is occasionally. seen to arrive with the wind in extensive flocks or strata, moving eer velocity, and by consequence overtaking each. other, until they form a dense stationary mass, pelt pe fadications. | This explanation of the origin of the @ i is rincipally deduced from an observation, which we havé now a often repeated. as to regard it as a me rological axiom ; that the temperature of the day following, exceeds that of the ddy on which it appears. Hence, when it coutmues to recur daily, the weather still grows warmer, until a thunder-storm, in some quarter o i tract, puts a period to the i ie sulation of the clouds, . ¥ pars ie ri of the Nature of the Cumulo-stratus. ¥ ~ P in attempting to assign nll, phenomena 80 compli gated, as those which this modification presents, we. may’ be . in ; THE NATURAL HISTORY OF. CLOUD Er: 55% in danger. of adinitting a sredter number thon are really ne- Nature of the cessary. ‘It is apparent, however, that in the stateof things guanble alg most favourable to the production of the cumulo-stratus, there exists a precipitation, independent of that which gives rise to. the cumulus, and situate in a higher region. -As this precipitation affords sometimes the cirro-cumuluS, at. others the €irro-stratus, we need not assign to it any other cause than the one already mentioned, viz.'a superior vapors ized ‘current of air, It is not inconsistent with the princi- ples we have laid down respecting the cumulus, that. this cloud should also be produced at the same time; it being Tequisite only that there exist a sufficient action of the sun on the Earth’s surface, or a sufficient tempers re derived. > _ therefrom. The inosculation of these two orders of cloud, | the singular union which follows, and the establishment af a new céntre of attraction, towards which the whole future. increase tends, is the prominent feature in this modification, | and the chief fact- which remains to be accounted for. As this effect i is hot constant and uviform, it cannot beascribed gravity alone. (Reasoning from analogy, rather than from pe” ex periment, which it is not easy here to apply, we may ' attribute it to a difference in the electric charge of the ree ks spective clouds; whi ‘differenée, though small, ought to produce the usual appearances of bodies charged plus and _ minus; wz. mutyal ‘appreach and contact. This effect, — er ppears to ensue rather with regard to the masseg than to the individual particles. i: - The a es highly, vapoled state of the higher ate me phere is a discernible in the cumulus from its earliest a aranice ; and it is easy to determine, at certain tiv that i ud, ¥f It continue long, ill: pass to the pres it modifica tion. The effect we mean t@ point ont is the ua- j ere growth of the cloud ; numerous small masses attaching ~ t emselves to its surface, fad ES PP *Ppearance not ‘unlike the curls of a fleece of ; particularly when seen beneath the sun, in a sityation where the projecting parts may catch the light. If we admit that the cumulus acts, as well by electrical attraction, as by that of gravity, on the ‘qurrounding materialayiwe r may here consider them as arriv- Re. : Rae: ue. i) 56 HE NATURAL HISTORY sevens! Nature of the ing by subsidence in too great plenty to be immediately assi~ ~ ig ame milated ; in consequence of which they tend to unite among themselves. A still greater quantity of haze, in the region next above the cumulus, gives rise: tothe curious phenome- rion of the cloud-capped cloud; when the cumulus is. covered. at its summit with a cirro-stratus; in the same manner as, ‘mountainous tracts, this cloud: reposes on dn elevated point of land. The causé is probably alike in each case; whether it be a lower temperature, ot a diminished electris- city, which determines to this particular spot the commence= ment of the aggregation of the cirro-stratus. “We may next. eonsider ¢umulo-stratus perfectly formed, erie r to OK a cause for its occasional long contmuance: which, however, exceeds the day of its formation only on the approach of thunder: this cloud, as well as the cumulus, very Commonly vanishing about sun-set, and. reappearing the next day, for some time. The two strata of the atmo-. sphere, which ‘forth the superior and inferior boundaries of the cloud, ate probably, during this time; in somewhat dif- ferent states of électricity ; the one alsoiidepositing water, the other receiving it; the broad surface of the cumulo¢ stratus may be tébatded: asa coating apphed to the upper stratum; and receiving from it 4 Céttinwal accession of x éharged particles of water, the electricity of which is slowly transmitted, through the intermediate portion, down to the base of the cloud, which is often some hundred below ; and where a continual evaporation counteracts the increase above. Here, while tiie fiiass continues in thi modification, Ys the progress of the electricity downwards is rested by the “dry air: for oMlipush the insulated rod is found som es to be. affected with positive, sometimes with negative s sigs, while the base of such clotids is over it, this effect is 1) thonly influential; and the rod is not charged, as es passage of the wimbuis.’. ow the electricity of this cloud is affected by the cons t evaporation of a portion at the base remains to be asééttained ; and the same ~~ be said “Gs to the Curmulus, x aah 21%, St, 430 OF ¥ ‘ THE NATURAL HISTORY. OF CLouDs: iF bn so oh the Nature of the Cirrus. “fof , she at Pe -. ; It was necessary to defer the. fendiline of the nature Nature of the of this cloud, until we had-developed, in a considerable de- cus. 0k the principles on which our theory proceeds. The rea ill have seen, that we assume the fact of the slow \ ‘beeneionetis icin of the electric fluid through‘clouds: which i this; as in a former ‘instance, we apply rather analogi¢ al. than b uction; the modification in question being us ally so high in the atmosphere, that the electric state of the Jatter, sit and below it, cannot easily be found by actual - experiment. Proceeding, however, on this assumption, we ~ ay suppose, that the cirrus resembles in its state fod of hi tay _ or a feather, insulated aud charged; or rather, that its ar~ rangements result from the same cause with those of the Coe Joured powders, which electricians project on a cake of wax, after haying touched it with the knob of a char ed phial, y and which fall into a variety of configurations. on, the sur- face. Thus the cirrus may be formed in the air ‘out. of such floating particles ater as are present, and may servethe purpose of collecting and travswitting the electric fluid. It is during the prevalence of variable Wide: that the cirrus most abounds; audit is reasohable to conclude, that the “portions of air; which at these seasons are transported from place to place, gliding over or intersecting each other, usu-_ _ally diff ufficiently in temperature to occasion a slight de~ cotiposition of the vapour of ‘one of the currents, and in their electric che rge sufficiently. to induce a communication ae: of the conducting medium so formed. Again, if gradual cooling of a siarfectiy ill plate of ait, _ situate af’ a great elevation, and cnsequently free trom y occasional causes of disturbance which prevail below, is not improbable. that the separation ene caioric from gly the vapour, and the collection Ne ed water from -the'air, may go on together, process similar to the f crystallization of salts, in which much caloric is liberated » into the medium. This opinion, at least, seems to be ad~ vanced by Kirwan, in his “ Essay on the Variations of the Atmosphere,” and we may consider the vegetating cirrus as ay {she tails ange of it. + ye Nad 58. igs THE NATURAL HISTORY oF Hout, , Wature of the Another conjecture might yet be started! lag) to the cirrus, cRrLs, It might Belfbgarded as a cloud wholly furmed of minute spiculze of ice; since bey air, at a certain elevation, 18 suf- : ficiently cold throughont the year for this effeet,, But. if | _ itshould be found, that the particles of clouds are susrep= as a le of a rectilinear. arrangement in any case | at a tempe- , isha 32°, there would be o necessity for this. _ Be tion. ee , S j ippearances of the cirrus areas frequ rious at sea as on land, it cannot bedoubted, the mariners yould find their account. in keeping, a. tae Soar of m, as , ae with, the changes of wind, &¢., making ¥ lows ge for. the change of station in. different « Dser van tions when under sail, : . The bnoyancy of the cirrus seems to be onto i ied during its first increase. It always follows, a atylength,. the gommon course of . gravity 5 and the change to the cirro+ eumulus, or cirroestratus, ‘which certainly sebeadi on. the « state of thé medium it falls into, may be peeriben to the tes ; teution or loss of the electricity. . _ @, iS t ie Of the Nature of the Nimbus. ] ~ ; ‘ ie Nature ofthe This phenomenon may. be thought to be improperly 4 | pint bus. denominated a modification of cloud, since it constatepssnally | of a column of descending. rain, snow, or hail, ‘seen in con- nection with the cloud affording it. As the ncluding | link in the chain of atmospherical precipitation, it seems, nevertheless, most advantageously placed ee ; and its his- tory, though far from including all that we may ve, and could wis o have explained, on the subject of rain, is ap > more decidedly illustrative of the nature of cloudsip general : than.that -of any other modification. Moreover it is. so tines mae be formed before the rain begins, wh t. ; affords sufficient ground, for considering it as a distinct _ } "modification of cloud. e owe to the bold and penetrate sang conjecture of Franklin, on the identity of lightning ih and the electric spark, the invention of a method of investi- gating the elegtricity of clouds: which, in the. hands. of experimentulists, has since brought out a mass of facts mbupdantly suilicient to establish that pr opositian ; ; and which a bigot 2 ; alsq * a : . rebated HISTORY OF CLOUDS. ) also throws aii light on the’ ne ‘rain, and other depositions from the atmosphere. - Hig method’ the structure of the nimbus may at any rates ae it passes over us, be demonstrated to be that of a natural conductor, by. which the positive charge of the higher atmosphere is brought: down to the Earth. For this purpose, there : a. provided a rod of ij p, or other metal, well insulated ona pillar of ished ASS, the latter being defended fr by an ose fupnel, soldered cr cemented to rH oe the rod ne ‘above it. The rod should be furpished aa several points of wire, a few inches long; and it aged not be ‘an elevated one for this purpose, provided thelfrenityg clear of other objects capable of drawing off the fluid. T charge i is ascertained by pith balls of a larger or smaller dias meter, to suit the occasion, suspended by flaxen threads, on a wire fixediinto the lower part of the rod, and terminating ina ball. Near the latter it is proper to have another ball fixed on a stont wire, passing into the ground, ] ‘ _ the ~ fluid, when ver may escape in sparks, ‘This instrus ‘ment exhibits a. ge of the same kind! with that ofthe ‘air in which it 1s immersed; or, in case of rain, &e., the charge of the latier, as compared with that of the air. We Phenomena will give, in the first place, the appearance which we have oS -yecently « observed during the passage over the rod of a nim- bus. of the most simple structure, having neither acumalus nor a cirro-stratus attached to it ; which moved along with othe lower current through the clear atmosphere, and. dis- ~ ‘the cloud came nearer, their ge charged a shower of large opaque hail, the air below being age ry. During the approach of the’ cloud from the north-east, the pith-balls remained close until the spreading “crown, , which characterizes this modification, had arrived in e zenith. At this time, affd while the shower itself. was It three or four miles distant,’ they cen seat e. As reased, until it ich time sparks of con- nes to full two inches, at able strength might be drawn from the rod. After i ‘the negative charge gradually went off, and the balls ; ‘touched again. Ina few moments the edge of the shower, mixed with a few drops. of rain, arrived at the conductor, we the oe opened Panes the charge gradually “ner easing _* / 5g electrical te shown, se» Whence the electricity ? Va THE NATURAL HISTORY OF -dipiiie inereasing v sparks were emitted more Heery than biafbre) This te Ginsct during the passage of the hail, and went off gradually as soon-as it was clear of the in- strument. After having closed, the balls opened again negative, and this charge increased to a considerable inten=. &. as the shower receded towards the south and south-west, ter which it gradually went off: the ball closed, and finally be slightly positive. From these facts, wh Onversant in electricity, will deduce the the lower part at least of the shower. He will see, that the descending hail formed a column positively electrified. is, which might be six or/seven miles in diameter, was surrounded with a cylinder of negative electricity, probably éxtending in every direction three miles farther, and result- ing from the action of the positive centre on the dry atmo-) sphere, im which it was moving. Now the afiiount of the hail, when melted, was considerably less than 7¢5th of an och in therain gauge ; and could the descent of the electric — Vv Aggie the whole space have been rendered as a to our serfs as that of the hail, we should probabl have said, that the\shower consisted of fire more Satta than of ices | ~ | The question that naturally presents itself is, Whence came this flood of electricity which accompanied the hail 2 ‘Ht was not from the circumstance of the water bein; frozen, reader, since a hard shower of rain equally exhibits a charge, but | with this remarkable difference, that whereas snow, sleet,’ and hail, ate always positive, rain is found sometimes positive, “ily ‘sometimes negative. The! reader may consult, 1s head, an extensive collection of facts in Read’s Journal of Atmospherical Electricity, “« Phil. Trans.” Vol. LEX XXII. The probable: sources of negative rain will be presen ‘yaentianed ; co returitto the question of the origin the positive charge; ; if we attentively consider the structure » of the nimbus, it is precisel at which, from the 5 poo _ |. properties of the electric fluid, we should propose for a ‘ductor formed: to acquire the latter. If we detach fro %:, the falling célumn, and extraneous clouds which caliete : attend its progress, it will be’found to‘consist of a close col- - lection of fibres; diverging fromthe region of the cumulus, = (where, ~ 1% HE NATURAL HISTORY OF CLoUDs. 61 7 calles: it appears, the rapid union ‘of the drops is aceomplished, ) to ‘a vast height and superior atmosphere. The conducting line, therefore, may be considered us prolonged from the’top of the column to the a extremity of each of these fine fibres of cloud, which are often extended, in all directions, as correctly as those of a tock of ur insulated on a charged onducolll nitiot alee ‘seems 'to be not somuch thepre~ — f water, as that of the electric fluid viii teers it. ee gl hs nsion.’ This purpose accomplished, (and the reader may conceive how great a discharge mu * effected. by a number of such machines acting at ence on a sinall ' tract of country,) the water wnites into larger drops through _ the whole extent of the atmosphere; it subsides in a con- tinuous sheet, -under which ‘the’ condensed productiof the ‘superficial evaporation amoves along, ‘in ‘the form denomi- nated scud; and the rain comes down freely and generaily, Scud. antil the atmosphere is disburdéned, or enti igre partial vacuum which is fo med brings in adrier air from the vorth= ads . - »*, . "Negative, as well as nonelectric rain (which sometimes Negative ox 7 falls, though strong positive and negative signs precede or aon desire i : rain. follow ‘it in the clear air) must necessarily result from the / ‘action of:a central mass of cloud, in which a strong positive char ger exists, on the clouds of less extent which Salli in its way; ; and jt is to be considered ‘also, that rain, at the eleva- 190n. ‘in which it is formed, may be perfectly nonelectric, ie ‘é. it may result from the union of clouds differing ia Ctricity, and hence noitiogamico, yet at the moment of arriving atthe Earth it may differ so much in its charge | from the atmosphere below, the only standard of comparison, o be strongly negative or!positive with respect to the’ | m” But these considerations belong more properly to we subject of atmospheric electricity. We shall conclude —— review of the modifications, Review of the - modifications ascending from the stratus, formed by the condensation of UP iowa » ‘vapdur, on its escape from the'surface, to the cumulus, col- lecting the water arrested in the second stage of the ascent; both probably subsisting by virtue of a positive electricity. g ‘From these ‘ergoceming, through the. paitiallggannel iia g Cc wml low ' 63 | ACCOUNT OF THE Lars THUNDER STORMS. - ewulo-stratus, to the civro-stratus and cirro-cumulus;:the latter ‘posi charged, and considerably. Tetentive of its charge; the former less perfectly insulated,, and, perhaps; conducting horizontally ; we arrive thus at the region, where the cirrus, light, elevated, ieee, -obeyaerety Mipulas a invitation of that. fluid; which; white it finds.a conductor, er operates in silence; but which, embodied and. insulated ina denser collection of watery atoms, « er or later bursts ; . ._. its bar#ier, leaps down in lightning, and wlidles cnimbus from its elevated station to the Earth. Je vit: oy bon istic) Lisp Ldod stiscdnis of the Riuhikiasoenn on the loth of August. Ino letter from THoMAs Forster, ips < St tic te Wine NICHOLSON, Esq. ; ee . y \ te he ie . Wish to communicate to your meteorological -reade some observations o the thunderstorms, that happéned of the 19th inst., of which I shall request your insertions). +) Weatheron © The 18th was warm, the maximum of: the thermometer the 18h. being’ ubout 73°. Cumuli prevailed duning, shit fs bat al , tdwnrds evening the cirrus appeared. The firststorm, Before 8 o'clock in the moruing of the: pie tbe side nit —ectibed. — -Gtoudedi Lb observed two strai@; the upper one ck a i be a uniform veil of cloa nile loose fliecky enmuli floatec beneath it 5 and in Rd large masses seeme id .attracted towards it, and adhered: to its surface, forming an capusual wavy skyy which in@rezsed in deisity.- . About r after eioht L beard a single explosion, like the repoy aay ; large brass cannon ; about twenty minutes after which two more guvh reports were heard owing each other ta vapid suceession, which were imm tely succeeded by. a loug -and Joud peal of rolling thunder, The storm now.cameup , every fast, ina Wisinctinnn neatly: costrary to that of: the eurrent— ind below, withbard ram, and thunder and) lightning. ak. the storm had subsided, cumuli were again seen sailing “ under oy be i by # Phunder- giorms on “~ , 39th. late! val, a af “i | . AccouNT OF THE LATE THUNDER STORMS, — 63 _ inder-a continuous sheet of cloud ; some of the n were loose Hoceuli, others'la arge well defined: masses. By, decrees they became lost in the upper stratum; the sky became again Second storm: very bl: ack, and thunder and lig htning with rain again pre wailed.” During the process of the storm I heard, (beside _ the many peals of rolling thunder) another loud single exe _plosion, which sounded like the hollow report of a. irate ‘it was preceded Byra very vivid flash of lightning. I dwell : Sree oe on this circumstance, because I het iiee? MO dani? ticed during storms two very dissimilar kinds of thunder. ~ One isa tue roll increasing in loudness wa ala this is ‘supposed by Mr. Bo P. Van Mons to Be caused by combustion of the two gasses of water*.: The other isa loud and sharp explosion of short duration, and often a sin- _ aglée report like that of a cannon; thé lightuing which pre- ~ cedes this is» generally . vivid. and mischiejous, | it darts di- _. rectly towards the Earth, or any other prominent object, as high trees, towers, &¢., and is considered by) Mr. B. P. Van Mons, as the flying off of électricity chow an over= ee ee cloud}. ‘I wish to direct the attention of meteoro- ogists to the solution of this question. When mischief is ze done by lightning, is not the thunder which follows the flash ‘ generally of this latter kind?» ” -»» The variations in the directiot’ of the wind iscsi in Various eur. ‘ stormy weather, as well as the contfary directious of the rca eek current. above, constitute another curious object of philo- ther, eee speculation. Small air balloons, might, -in- this Small atr bal- ease, become useful meteorological instruments. I have !0°¥8 45 4 me he Mass iit oe teorological -sent-up)a great many of the d have generally-seen them jnsttument. moved onan’ different currents of air. ‘ x oay ‘Ks a midisybys Yours &c. Clapton, Hackieyj © = = ~~ THOMAS FORSTER. a. aed Aug. 1811?" if oni we # See Journal —: 1809, Vol, XXIV, p. 106. me tThe distinction ‘of rain, into’ “ rain of the decomposition,” and tain e recomposition” of air, by ‘Mr, Van Mons, has induced me to ing - quire, What is the electric state of rain with a tising, and: what with a ‘etiny barometer ? ; ee ¥ pe % it : _ ani : 4 ‘gym 24 iba. Tec’ cee n 64 aan Yee. dere eae EX ROLOGICAL JOURNAL. , oo # * PRESSURE, Wind| Max. {| Min. JULY 19° TN W 9-91 13° W 979 14 |S W 9°76 15 |S 9°80 16 |S W 29°83 17 |.5 29°75 is |S W 19 |SE 29°75 20 | W 29°90 21 |Var 29°82 22 |. 29°88 23 |N W 30/01 94 INV 30°11 25 INW 30°12 26 \SW - 80°09 5 ie 29°91 28 |SE 29°85 29 |N E 29°85 30 | N |.30°114.30°08 81 |N E| 3008} —— AUG. , 7 1 |N-E| —— ] 29°90 2 | S | 29°90} 29°69 3 |S W| 29:67] 29°58 4 IN W| 29°73] 29°60 5 | S | 29°65] 29°62 6 | S | 29°59] 29°48 7 |N Wy 29'60] 29°50 8 |S Wi 29°49] 29885) 29°45 g |N Wj). 29°60}. 29 48 | 29°54.) 64 10 |N W/ 29:86] 29°60) 29°73 | 6. 29°35 29°35] 78 14 TAN. ab sh ue < “3 Pe pai Pe . ; Ou ey | a N.B. The observations in each line of the Table apply to a period of twenty- four hours, beginning at g A. MY on the day indicated in the first column. A dash denotes, thatthe result is anchuded in the next following observation. 4 ie - ae cae em SA NOTES Me @ Fi METEOROLOGICAL JOURNAL. NOTES. July 15. Small rain about2 p.m. 19 A thunder shower early: fine day. 20,21. Forty-eight hours rain 92. Temperature 60°, (the maciumum of the period) at 8 a.m. 25. Orange-ccioured cirrt at sun- | set. 97. Thunder clouds: afewdrops p.m.: muchdew. 98. Cirroe cumulus cloud, very beautiful, interchanging with cirrostratus, succeeded — by large cwnuli. In the evening some appearauce of a thunder storm farintheN W_ 29. » one parallel bars of cérrostratus, stretching E. and W.: ‘Bhiush on the twilight. 30. W indy, cloudy. oe Aug 2. Large elevate! cirré. 3. “op Sie followed by cirrostratus: evening overcast: rainby night. 4. Windy, at S.W. by night. Cumue lostrati, in various quarters, at sunset. 7. Opaque twilight, with cu. mulostratus. 8. Very wet, a,m.; atnoon a thunder shower; at 6 p. m. a heavy squall from N.W. with rain anc hail; the nimbus, as it receded, presenting a per feet and brilliant bow: windy y night. 9. Large cumulé rose, and at noon inosculated with the clouds in a superior stratum: a thuuder shower ensued before 2 p m., after which appeared the distinct strata again: about 6 p.m. a ecand thunder shower, long very dense in the S E.; where the bow was conspicuous above an hour. This day was nearly:calm. 10. Rain fell again about noon, upon the union of two strata of cloud. ~~ — i Mat ea RESULTS. Prevailing winds, westerly. Barometer: max. 30°15; min 29°35. Mean 29-635 In,’ Thermom. —— 78° (eh amen. GUM aguas _ 378 In. sis Rain » $37 In. . : Cheracter of the period changeable, with much rain. T F’ a Pe & ae ae WE 8 ' Pot ’ ve ‘ ri I have the satisfaction to acquaint my teaders, that the. eteorological Tables and Remarks, which will hereafter appear in this Journal, will be extracted (as the present has te from. the journals of Mr. Luke Howard, whose Trea-. se on Clouds, inserted j in the present number, and long _ known and valued by the pt Hic, will make it unnecessary for me to express, in any direct terms, that sentiment of obligation, which myself, and the other cultivators of sci« ence, must entertain for his researches. W.N. | . “A Vou. XXX.—Sser. 1811. ile ail \ Mode of ana- lysing vegeta- . ble and ani- mal sub- stances, Difficulties, ' Methods of obviating them. ANALYSIS OF VEGETABLE AND ANIMAL SUBSTANCES. Xe “Abstract pie a ) Memoir on the ‘Analysis of Vegetable and Animal /Substanees : : by Messrs. Gay-Lussac and THeENanp*. | Wri HEN we conceived the design of studying the ana- ‘Tysis of animal and vegetable cubdiancedt the first idea that “occurred to us was, to convert, by means of c oxigen, vegetable ‘and animal substancesinto water, carbonic acid, and nitrogen: ‘and on thig we fixed our attention. It was evident, that, if ‘we could effect this conversion so as to collect all the gasses, this analysis would attain very great, accuracy and simphe vity. Two obstacles appeared in the way. of this: first, the burning of the hidregen and carbon of these substances completely ; and, secondly, the effecting of this combustion in close vessels, ‘The first we could hope to surmount only by. means of mening oxides, that easily part with their oxigen, or of the hyperoximuriate of potash. A few trials soon led us to. pre- fer this salt, which succeeded beyond our expectations. It was far from being so easy to surmount the second: for we could not attempt the combustion in a retort filled with _mercury 5 since the retort would have burst, had we burned Apparatus re- quisite. that the results should he t very, -y perceptible : and ‘Description of af apparatus: answering these purposes, ever so little in this way. It was necessary therefore to con- trive an apparatus, in which we could Ist, Burn parts of a substance so small, that ‘the ‘vessel: | should not crack : Qdly, Effect sucha num r of combustions ees f co th iets _.8dly, Collect the gasses as they were formed. at An apparatus of this kind we lay before the class. It i¢, formed of three separate pieces. One is a tube of very ‘thick glass, hermetically sealed at the lower end, and open at the upper 5 about 2 dec. [7 87 in} ong , and 8 mil. 315 lined] in. diameter. This has.a very Bean tube, likewise of glass, ; similar to w hat would be adapted to a retort to receive gas- ns Be, joined laterally to it by) ae cof the blowpipe 5 ent. * Ann, de Chin: Vol. LEXIV, hs af ase to the Institute va ra of January; 1810.. af €aK, alii {1°97 in.] 40 Ret (OQ atiad Mia ANALYSIS. OF VEGETABLE AND ANIMAL SUBSTANCES. 67 tl ‘97 in.} from its aperture. The second is a brass collar, in which the open end of the large glass tube is fixed by means of a cement, that will not. fuse under 40° [104° F.j ‘The third piece is a coc ‘k ofa peculiar construction, in which all the merit of the apparatus consists. The key of this cock is solid, and may be turned into any position, without giving passage to the air; but about the middle of its Tength it has a superticial cavity, capable of holding a subs ‘stance ‘the size ofa small pea. This cavity is so contrived, that when uppermost it answers to a small vertical funnel, which enters into the nozzle, and forms as it were its exe “tremity ; and when lowermost it communicates with the body. of the cock, which is perforated, and screws into the brass collar before mentioned. Thus on putting small fragments of avy thing into the funnel, and turning the key, the cavity is filled with them, and conveys them, on continuing to turn it, into the body of the cock, whence they “fall into the brass collar, and so to the bottom of the glass tube. If this matter therefore be a mixture of some vegetable Its applicag substance with hyperoximuriate of potash in suitable pro- ye portion, and if the lower part of the glass tube be suffici- ently hot, it will scarcely touch it before it is vividly 1 in- ‘flamed ; when the veyetable substance will be instantane- ously destroyed, and converted into water and carbonic acid, which may be collected over mercury, with the super= “fluous oxigen gas, by means of the small lateral tube. To perform this operation readily, it is necessary, that Preliminary the matter should separate entirely from the cavity, and steps. fall to the bottom of the tube. For this purpose it is to be _made into small balls, as will presently be described. It is Preparation of necessary too to inquire, what quantity of hyperoximuriate pi arb “will, be sufficient for burning the vegetable substance com- i pletely ; : and at least half as much more must be used, that ‘the combustion: may be perfect. But of all the preliminary steps the most seiroratits is the Analysis of analysis of the hyperoximuriate employed, for all the cal the nyPeroxi- muriate. culations of the experiments are ai in great measure on this analysise ; All this being well understood, it will be easy to-conceive, F 2 how 68 Process de- scribed. ANALYSIS OF VEGETABLE AND ANIMAL SUBSTANCES, how a vegetable substance may be analysed with the hypers oximiuriate. Let the substance to be analysed be carefully levigated, and let the byperoximuriate be levigated sepa- rately : weigh the quantity of each, dried at the heat of boiling water, in a very sensible balance; mix them inti- uiately, moisten them, and mould them in cylinders; divide these cylinders into small portions, and round them be- tween the fingers like pills; and lastly expose these to the temperature of boiling water for a sufficient time to render them as dry as the powders were before. If the substance to be analysed be a vegetable acid, it must be combined with lime or barytes, before it is mixed with the hyperoxi- muriate; the salt thus formed is to be analysed, and. ac- cdunt taken of the carbovic acid that remains united with — the base after the experiment; in fine, if the substance to be analysed contain any thing foreign to its nature, account tnust be taken of this also. Thus we know with precision, that a given weight of the mixture answers to a known weight of byperoximuriate and the substance to be analysed. Now, to fivish the operation, all that is required is, to bring the bottom of the tube to a cherry red heat; to expel all the air by means of a certain number of balls, which need not be weighed, and which are dropped into it one “after another; and then to decompose a quantity accurately Proof of its ac- curacy. Caution, Analysis of the acces, weighed, and carefully collect all the gasses in phials filled ‘with mercury, and previously measured. If all the phials be of the same size, they will be filled with gas by equal weights of the mixture; and if the gas be exainined, it will be found precisely similar, an evident . proof of the extreme accuracy of this mode of analysis. ” During the whole of the process the tube should be kept at the highest degree of heat it can support without fusion, that the gasses mayjcontain no oxicarburetted hidrogen, or as little as possible. In all cases the analysis should be made over mercury. This isa trial which is indispensable, It is sufficient to mix them with a fourth of their bulk of hidro- een, and to take the electric spark in them. As. they it- clude a great excess of oxigen, the hidrogen added, of which account must be taken, | burns as well as all the oxicarbti= ~~ tetted 1 all animal substances. ‘But as these substances contain ni- trogen; and nitrous acid gas would be formed, if an excess of hyperoximuriate were employed for burning them; only _ such a quantity must be used, as is sefficient to reduce them ANALYSIS OF VEGETABLE AND ANIMAL SUBSTANCES. 69 yetted hidrogen they may coptyin; and thus we acquire a certainty, that they uo longer censist of any thing but car- bonie acid and oxigen, the separation of ie is to be ef fected by means of potash, ' ~ But this necessity of raisiye the temperature so high, Farther pre obliges us, on the other hand, to take some precautions for scary, preventing the cock from beipg heated. For this purpose the glass tube is passed thrqugh a brick, toto which it is luted with clay, which has the advantage, at the same time, ~ of rendering the apparatus firm; and besides, a smali hol-- low eyliader 4 is soldered to the body of the cock, to contain water, or ice, which is stil il better. Thas we have all the necessary data for knowing the pro~ Data. portion of the principles of the vegetable substance. We know how much of it has) been buvned, for we have its weight to half a milligramme, [about eight thousandths of a grain]; we know how much oxigen was required to conyert: it into water and carboniejcid, since the quantity is the dif- ference between that contpined in the hyperoximuriate and that found in the gasses produced: lastly, we know how much carbonic acid has been formed, and can gale ‘alate how much water must have been produced. By following the same method of analysis, we may equally Analysis of determine the proportigns of the constituent principles a completely to carbonic acid gas, oxicarburetted hidrogen, and nitrogen, which Are to be analysed in the mercurial eudiometer by the fommon methods, whence we deduce _ with precision the proportions of we principles of the ani- mal substance itself} The mode in whieh we proceed j in the analysis of vegetable Small _quanti- fan: animal substances being exactly known, we may say ah baka oA what i is the quantity we decain ase; without fear of dimi- curates , -nishing the reliance, that may be placed on our results. This quantity extended, at most, to 6 dee. [9°27 grs.] If, however, the least doubt should arise respecting their exs freme accuracy, ye should remove it by observing, that we $ filled 70 ANALYSIS OF VEGETABLI} AND ANIMAL SUBSTANCES, filled with gas two and sometimes three phials of the same - size In. succession; that these gasses were | absolutely the same, and always came fron) the same weight of the sub- stance, Accuracy ofan We may add, that the en i of an analysis depends analysis de- much more on the accuracy of the instruments, and.of the pends chiefly on the niccty Methods employed, than in the quantity of the substance on of the appara. which we operate. The analysis of air is more accurate tus and of the | apna method, than any analysts of salts, though it is made on twovor three hundred times less matter : becuse inthe former, where we judge of weights by very considerable bulks, the errours.to which we are liable are perhaps ‘en or twelve hundred times less sensible than in the second, where we have not this re- source. Now, as we convert ito gas the substances we ana- lyse, we bring our analyses not merely to the certainty of ordinary mineral analyses, but to that of mineral analyses of the greatest accuracy ; particularly as we collect at least a quart of gas, and in our methed of proceeding itself find the proof of an extreme.accuracy, ead of the most trifling errours. Vegetablesub- By this method, and with all the wD post dhh we > have gelee vee mentioned, we have already analysed sixteen vegetable sub- stances; namely, the oxalic, tartarous, mucous, citric, and acetic acids; yeilow resin, copal, wax, and olive oil; sugar, gum, starch, sugar of milk, beech wood, oak, and the cry= stallizable principle of manna. The results we have obe tained seem to us highly interesting, for they have led us to three remarkable laws, to which the composition of vege- tables is subjected, and which may-be expressed as foliows. Laws of vege- I, A vegetable substance is always acid, whenever its oxi- pi compesi- sey is in greater proportion to its hidrogen than would. form water. 2. A vegetable substance is always. resinous, or oily, or. alcoholic, &c., whenever its oxigen is in smaller Beswestion to its hidrogen than would feat water. ” * Lastly, a vegetable substance is neither por nor re= sinous, but analogous to-sugar, gum, starch, sugar of milk, woody fibre, or the crystallizable principle of manna, when- ever its oxigen is in the same proportion ta its hidrogen as would form water, i Lele ! Thus, \ ANALYSIS OF VEGETABLE AND ANIMAL SUBSTANCES. 71 ‘Thus, if we were to suppose, for a moment, that the his Vegctable drogen end oxigen were in the state of. water in vegetable 21%: substances, which we are far from considering as true, vege- table acids would be formed of carbon, water, and oxigen, in different proportions : CASING Resins, fixed and volatile oi! 3, alcohol, and ether, would resins, &c, be formed of carbon, water, and hidtogen: also in cde BePertion:: and | | : Lastly, sugar, gum, starch, sugar of wn woody fibre, sugar, &c, : ‘and the crystallizable principle of manna, would be formed : of carbon and water ‘alone, and would differ aml aye oe : greater’or less quantity they contained. : 'This we may show by quoting various ‘analyses. of ver and resinous substances, and of substances that are neither ‘acid ‘nor resinous, . 2 A hundred parts of oxalic acid contain. Constituent principles of Carbone ‘26-566 Carbon voccescesseesess 26°566 oxalic acid, Oxigen++ 70°689 \ Oxigen and hidrogen in the’ . : or | proportions that form water 22°872 muorogen A Sia Oxigen i IM EXCESS seeeeees 50° 562 100° OAM ie ‘Too A hundred parts of acetic acid contain. | andaceticacid. “Carbon-+ 50°224> (Carbon -+-.eeecsseseees 50°94 Oxigen-+ 44.147) Oxigen and hidrogen in the ; Bee SL or< proportions that form water 46°91 Hidr ogen 5°629 Oxigen in excess s++--2-. 2°865 100 — 2 - 100 / ~ Oxalic.acid therefore contains more than half its weight These the two of oxigen in excess with respect to its hidrogen; while-in “emes. “acetic acid this excess is not quite three hundredths. | <- | These two acids ‘occupy the extremities of ‘ihe series of vegetable acids: one is the most oxigenized of them, the other the least. This is the reason why-so much nitric‘acid Explanation is required to convert sugar, gum, &c., into oxalic acid; en i ie why, on the contrary, many vegetable and animal substances =~ ‘so easily produce acetic acid'in a number of instances ; ;-and why, in particular, wine is changed into vinegar without Prat 3 : the 79 ANALY3IS OF VEGETABLE AND ANIMAL SUBSTANCES. | the formation of any intermediate acid: a phenomenon hi- therto unexplained, because vinegar was considered as ‘the. most oxigenized of all the acids. Pasian A hundred parts of common resin contain principles of Carbon ee seeceerseviesrervsocrceccvnre6ecnc as Me i common resin, 75°944 Hidrogen and oxigen in the propor tions that form water esevreceeroeapeeeevovsee®eeetseuseeeveeevpenesd 15°156 Hidrogen in excesg s+ereesescescecseccoeceees 8900 100 olive cil, _ A hundred parts of olive oi} contain Carbon eo eoeeecsroeesee nmeevreeorevoeneneeooneeeese®e 77°21 Hidrogen and oxigen in the proportions that form WATE cece reereescocesecevesssesessveceeeerers 10°712 Hidrogen in EXCESS ccettrcccvce pe pesecencerver 12°075 - 100 eee! crystallized sue -A handred parts of crystallized sugar contain 5s R Carbon s+eeesceerercees 40°194 Carbon: 40°194 Hidrogen and oxigen in.the Oxigen++ 52:101 proportions that form water 59°806 Hidrogen 7°705\, 5, d Oxigen in Excess e+eees -- 0 a Hidrogen in excess «+es+2 O 100 Mean 100_ and beech A hundred parts of beech wood contain wood. : Carlon ecesesvcececeses 51°192 Carbon++ 51°192 Fidrogen and oxigen in the Oxigen++ 42°951 proportionsthat form water 48°808 -Hidrogen 5°857\, oy 2 Oxigen in excess -e+-++++ 0 \ Hidrogen in excess ereses O 4 es 100 Vegetation so- These results evince a very important truth, which ‘is, lidifies water, that vegetables; in the act of vegetating, solidify water . entire ANALYSIS OF VEGETABLE AND ANIMAL SUBSTANCES, 75 entire, or its principles: for, all vegetables being almost o, # 3 princie wholly composed of woody fibres and mucilage, which cone Ples- tain oxigen and hidrogen in the same proportions as water ; it is evident, that, being taken into the vegetable, it com- bines with charcoal to forin them. ‘Vf therefore it’ were in our power to unite these two Sibe Requisites te stances in all proportions, and to bring their particles to the fabrication re of vegetable a suitable degree of approximation, we should be ‘able imatters. to mike with certainty ail the vegetable substances, that’ occupy the mean between acids and resins, as sugar, shone woody fibre, &c. Of animal substances we have hitherto analysed OMY A nimal suB: fibrin, albumen, gelatin, ‘and’ caseous matter. stances ana- ‘Tt follows froin our analysis, that, in these four substances, lysed. General cons and probably in all similar animalysubstances, hidrogen Qusions, is in a larger proportion to oxigen than in water: that, the greater the excess of hidrogen they contain, the greater. ‘too is the quantity of nitrogen found in them: that these two quantities are almost in the same propoition as in am= monia; and it is probable, that this proportion, to which we come near, really exists; particulariy as we always find a little too much hidrogen, and all the errours, to which we are liable, tend to increase the quantity of this priuciple. The reader may judge of this from the two following analyses. A hundred parts of fibrin contain Convechent. 7 en Ap Webbtiserelahe «4A iplasn an 0° a tania ame se 2. eieis «) SLOTS “Ai alae Hidregen and oxigen in the proportions t. at. form MENS. of ae Dateline de weldwnie peewee so5 sie; J00607 Hidrogen i IT) CXGESS soccer cecccaccscessersrsee 5°337 eas 5616 ay. 9% siatble arm Hreibie Hale's oo 6 > 200k dod 100 - “A hundred parts of caseous matter contain and of cheesy Carbon Sette eee sus eceesecues se sessacorne 57-190 matter. Hidrogen and oxigen in the proportions that form - WATLEY se rcecrecccsnevcnerscsreuserecsecsss 16°778 enenete HbERC Rss reaondsecbannbtenrns tay oi 5°680 DECOSEH bop penevvecsccr nce. orenerasesecess 18°952 . neta i - 100 bigs | Admitting Files SILEX SUBLIMEZD IN IRON WORKS. Analogies be- | Adanitting this proportion, these substances would corre- aan spond, with regard to the rank they hold among animal — table king- substances, to the rank occupied by sugar, gum, woody dota. fibre, &c., among vegetable substances: for, as hidrogen and oxigen, the gaseous principles of these, are capable of mutually saturating each other, and forming water; hidro- gen, oxigen, and nitrogen, the gaseous principles of those, can also mutually saturate each ther, and forin water and ammonia: so that carbon, the only fixed principle they all contain, bas no property that acts in this saturation. If we allow ourselves to be guided by analogy, in this point of view, we should compare the animal acids with the vegetable ecids; and the animal fats, if there be apy that contain. nitrogen, with vegetable oils and resins; consequently there is nota aibeiont. quantity of hidrogen in the uric acid to saturate the oxigen and: nitrogen this acid contains, or to — form water and ammonia by combining with these two substances ; and in animal fats the contrary must occur. © The subject te No doubt many more consequences may be drawn from be pursued. the preceding results: but we reserve for a future paper this inquiry, of the extent and EER of which we are fully aware. : XI. Chemical Examination of a. white, filamentous Substance, found in the Cavities of the Cast Iron that adheres to the a Sides of high Furnaces: by Mr. Vauquentin*. Pieces of iron I N smelting iron ores there are dcouneatle paslinda af me-. aoe tal, which, beginning to assume the character of iron, and the furnace, congealing the moment before the iron is drawn off, remain, and containing ee to the sides of the furnace. In these pieces cavi- alg sub- ‘ties are frequently formed, which are filled witha white fila~ mentous substance, like flexible amianthus. supposed tobe Several metallurgists have spoken: of. this niheaiintes exide af cine: Grignon in particular hasconsidered it as an oxide of zinc :/ # Ann. de Chim vol, XXVII, p. 192. . Extracted from the Ann. des Museum Hist, Nat. An. 7, er but SILEX SUBLIMED IN IRON WORKS, 75° but he, no doubt, relied on the external appearance, for it does not contain an atom of this metal. To satisfy himself whether it were really oxide of 3 zine, It is not solu. Mr. Vanquelin boiled some with different acids, but none Pe i® acids. of them bad any action on it: they did not dissolve an atom, This led to a doubt of the truth of the assertion of metal- lurgisis, respecting it: and the following experiment con- vinced him, that they were altogether mistaken. Having heated this substance with thrice. its weight. of Treated with caustic potash in a silver crucible, it was completely fused, potash, and the mass produced was entirely dissolved by water. Nay rere The solution . supersaturated with very dilute~ muriatic acid, acid did not become turbid, ‘but was converted into a white transparent jelly by evaprratione which is. never the case with zine. When this was perfectly desiccated, and the residuum treated with water, a. white powder was-obtained, which, when-washed. and dried, did. not differ from, the. original quantity taken a hundredth and half. This powder exhibited .all the characters of the purest.it was found _ silex... No other earth existed in the liquor from-which. itt? be silex. had been separated, and not even any sensible quantity of: oxide of iron. The difficulty consisted not in finding the nature of this How is it se- substance, but how it was formed in the cavities of the iron, P+rted? How indeed are we to conceive, that the silex, which is always mixed with alumine and lime both in the ores of iron, and in the fluxes employed, should have separated from these earths in a state of such perfect purity, that no perceptible Ganatty's of ferign matter can be discovered withit? >” a The filameutous, and as it were cry stallized state of this Apparently by sublimatione silex announces, that it was converted into vapour by the violence of the fire, and afterward ge tly conden: ed in the parts of the furnace that were less hot. ' This wonld prove, not only that silex is volatile at a suf- ficient temperature, but that it is more so than alumine or lime; unless we suppose these two earths to have been raised to a greater height, which is not probable. XH, y ? * 76 Buryknot ap- pietyec. Vs good qua: hities, ¥ hears in a year’s growth, SURRKNOT APPLE. KIi, An Account of the Burrknot Apple. Ina Letter to Henny Grimston, Esq. F. HW. 8S. By the Rev. Joun SImPson*, MY DEAR SIR, OUR letter met me on my return home alter a month's _ ramble among the mountains and lakes in Cumberland, and T now send yeu a short description of the apple tree galled here the burrknot. At a proper season J will for- ward to youa few knots, or knobs of it, for trial, which, put jnto the ground, will make a long shoot, the followwg - spring; or, if you wish it, 1 will sead you a few knubbed branches. with blossom bunds upén them, which will bear a hittle the same year, but you must observe the smaller knobbed branches with blossom buds will not make sack | fine or handsome trees as the others. The burrknot apple treet is uncammonty productive. My trees never miss bearing, not being so liable to blight in inclement seasons, as other varieties. The fruit is large, its tints resembling the ribston pippin, and about itssize. Fer culinary uses, it ig not inferior to the choicest codlin, anda» much better keeper. The tree is not liable to canker, ewing, lam persuaded, to its not patting out a taproot, » bat spreading its bumerous fibres from the knob horizon- tally, and following the richness of the sail. Our late wortny and valuable friend, Sir Christopher Sykes, observing my trees of one year’s growth with fruit upon thein, was astonished, and the following year had the pleasure afexhibiting some of the knobbed branches, which J gave him, adorned with fruit m his own garden to his friends, of which you have ‘probably been an eye witness, having visited so frequently m his time at Sledmere, If you wish for any other information that I can give respect- ing this applectree, I shull be happy to send it, and-remain, ‘ Dear sir, Rooss, near Patrington, — Yours very truly, July 25th, 1808. JOHN SIMPSON.” * Trans. of the Horticultural Soc. Vol. J, p. 120. + Specimens of ihe fruit, and branches of this apple. tree from Reoss, | whichis also plentiful ia L ord Hawke sbury’s garden at Combe, were ex- pikited at the migeling ef the Society, held Dec. 6th. XIII mens ive i) ‘y | SPRING GROVE CODLINE. 77 XIU. A short Accouit of a new Apple, called the Spring Groté Codling. By the Right Hon. Sir Joseru Banks, Bart. K. B. P.R.S. &c.* : > aly the request of Mr. T. A. Knight, Il beg ae to lay Spring Grove before this Society the opinion formed by my friends and pene myself last autumn, on the merits df an apple produced by — one of his judicious mixtures, which he has done me the honour to call the Spring Grove codling. In the beginning of September, I received a amall bot — of these apples, which were fully ripe; when baked they had all the quickness and flavour of the best winter apples; and a considerable tinge of red. All who had tasted she pie agreed, they had not met with any autunm apple which for baking could be compared. to thisnewone, Mr. Knight informs me, that it is ready tts seacdn of for use in the month of July, at a season when Lendon ‘pening. geese are probably better than-at any other; but when the | old) English accompanyment of apple sauce was not, till” Mr Knight furnished us with this apple; possible to be Sbtained; in this view it becomes an addition of importance to the old English kitchen, the cookery of which true Englishmen still prefer to French ragouts, or to Spanish olios. 1h proves of the burr apple kind, atid may be accordingly Of the birt prepazated by cuttings without difficulty, which will bear 2PPl¢ kind: the next year, as well as by grafting, Mr. Hooker, who solours the Pomona Herefordiensis, has made a very excel- cellent representation of this fruit, of which a copy actor panies this communication: as a retord in the archives of the Society it may hereafter become a useful, as well asa valuable deposit. The tree grows freely, and bears abundantly. |. Trans. of the Hortieultural Society, vol. I; p. 197. SCIENTIFIC 78 SCIENTIFIC NEWS. SCIENTIFIC NEWS. Properties of Dr. Delaroche informs us, that he has made some curi- radiant heat. Prize subject, Medical and chirurgical jectures. ous experiments on radiant heat, which he intended to lay ‘before the Institute. He ascertained, that the heat émitted by radiation is not proportional to the exeess of the temperature of the radiating body above the cireumambient medium, but that it increases in a much more rapid ratio. Thus, taking the quantity of heat emitted with an excess of 87° to be 1°, the quantity emitted with an excess of y00° wilt be at least 70°. He also found, that the quantity of unluminous calorific rays that traverse glass is much greater an proportion to the total quantity of rays emitied, when the body that emits them is very hot, than when it is less so; and that the nature of the unluminous calorific rays is not identical, but varies according to the temperature of the source that emits them. ao, So = At the request of Mr. Bertho!let, the French Institute has proposed for the subject of a prize a determination of the specific heat of gasses. : — St. Thomas's and Guy’s Hospitals. . The Winter Courses of Lecturés at these adjoining Hos- pitals will commence the first week of October; viz. ) At St. Thomas's. Anatomy, and the Operations of Surgery, by Mr. Cline, and Mr. Astley Cooper. ( Principles and Practice of ae by Mr. Astley | Cooper. . At Guys. Practice of Medicine, by Dr. Babington and Dr. Curry. Chemistry, by Dr. Babington, Dr. Marcet, and Mr, Allen. Experimental Philosophy, by Mr. Allen. r Theory of Medicine, and Materia Medica, by Dr. Curry and Dr. Cholmeley. Midwifery, and Diseases of Women and Children, by Dr. Haighton. : Physiology, or Laws of the Animal CEconomy, by Dr. Flag tton. ; Structure SCIENTIFIC NEWS. Structure and Diseases of the Teeth, by Mr. Fox. N. B. These several Lectures are so arranged, that no two of them interfere in the hours of vaeadance: and the whole is calculated to form a Complete Course of Medical and Chirurgical Instructions. London Hospital. Dr. Buxton’s Autumnal Course of Lectures on the Prac- tice of Medicine will be commenced on Wednesday, the 2d of October. — Anatomical Theatre, Bristol. Mr. J. Shute will commence his Winter Gourse of Lec- tures on Anatomy, Physiology, and the Principles of and Operations in Surgery, on Tuesday, October 1, at eight __ e’clock in the morning. mere eae 79 ° Mr. Vergne has lately analysed the mineral waters of St, Analysis of the Felix de Bagnére, near Condat, in the department of the Lot, and the following were the results. .Four pounds ten ounces of the water, evaporated to dryness, left a residuum of 113 grains.. From this he obtained Muriat of magnesia -eseseseseesee 6 gts, Sulphat of magnesiae+scssessseeee A] _ Sulphat of litte s sie cece ses eedeees BG) ~\ Carbonat of lime »-.cceccccescees 20 Carbonat of iron «+-sseccoscvccee 195 bast ‘Fatty matter oosscsccsecccecscces 1 there being a loss of 7:5 grs. The fatty matter had neither taste nor smell ; thrown on burning coals, it changed colour, shrunk up like an animal substance, and emitted a very fetid smell of carburetted hidrogen... The heat of the water, taken from the spring at noon on the 21st of June, 1809, was 66°4° F.; and its gaseous products were a moderate quantity of carbonic acid, and still less sulphuretted hi- Bet — i: pre The water of the bathe of Ussat, near Tarascon, about ten miles from Ax, have been examined by Mr. Figuier, professor of chemistry at Montpellier. He found its heat, taken at several times and at different hours, from 27° R. to > . 30°5° mineral water of Bagnére. Water of Use sat. O SCIENTIFIC NEWS. (06 duum, from which were obtained Muriate*of magnesia ++eeeseeeees 042 grammes - Sulphate of magnesia ++++++,e+++ 3:38 Carbonate of magnesia <«¢++seee.+ 0°12 r Carbonate of lime ee e+eseee-eee+ 3°98 | Sulphate of limeseos+eresesesees 3°75 10:95 The new spring contained rather less both of carbonic- 30°5° [92°7° to 100°6° F.]. It contained about a sixth of a cubic neh oftearbonic acid gas ia a pound of water. 12930 grammes } yielded, by evaporation, 11 grammes of dry resi- acid and of solid residuum, but the difference was trifling. The mud collected at the bottom of the baths consisted of ia it Aluiiines > «oc. eCmerecosrsreresecerce 40 Rene Carbonate of lime eoeessescceseees 20 — Sulphate of lime -++eeseeeeeeeeee 10 Oxided or carbonated iron e++e+eee* Q Silex cease. ceccccecccsccesesseccs 2B | 100 eee Water of Nie. We have alsoan analysis of the mineral water of Nieder-~ qexbrunn. brunn, in the department of the Lower Rhine, by Profes- sors Gerboin and: Hecht, of Strasburg. About half a kilo- gramme, or one pound *, of this water contained Muriate of Soda seee,seesee 1°8 cramme = 27'S grs. Sulphat of lime -«-ccee..cee GL 1°54 | Carbonate of Inme, dissolved in ‘ Carbonic acid «-,+e+esees O45 6°95 Carbon. of magnesia, thesame 0-21 3°24 Carbon. of iron, the same++-+ 0:07 3 1°08 Muriate of magnesine oseecee 0°96 4°02 Muriate of ea ve 0-345 5°33 ugsburg Iu Augsburg and its vicinity, which are celebrated for eet. good beer, it is customary to put inte each cask a small bag of the root of the geuin urbanum, avens, or herb bennet. ve os te: * Probably the Strasburg pound == 7277 grs. Eng. C. A AOU RN AL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. OCTOBER, 181%. ARTICLE I. On the Destructton of an Enemy's Fleet at Sea by Artillery : by W. Moore, Esq., of the Royal Military Acadenty, Woolwichs Levwua IL y two Spheres of different Diameters and Different specific Law of resist Gravities impinge perpendicularly on two uniformly re aid faa — _ sisting fisted Obstacles and penetrate into them; the Forces which retard the Progress of the Snheres will be as the - absolute resisting Forces or Strengths of the Fibres of the Substances econ and the Diameters aad specific Gravis - ties of the Spheres inversely. i Ler R and r denote the absolute resisting forces of the Proof, two substances ; F and f the retardative forces; D, d, the © diameters of the spheres; Q.q, their quantities of mat- ~ ter; and N and n their respective specific gravities. Then the whole resistances:to the spheres, b@ng proportional to the quantities of motion destroyed in a given time, will be as the absolute resisting forces of the two substances and quantities of resisting surfaces jointly; or, as the resisting forces of the substances and squates of the diameters of Vou. XXX. No. 137.—Ocr. 1811. Qa the 89 CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SBA: the impinging spheres; because the surfaces of spheres are as the squares of their diameters ; that is = = x % a it r Pion . But in general — = — & be : Therefore m Be equating these two values of the whole resisting forces wé Bee Qi vi ae a Bow D? x 7 ; and since we quantities of. matter in spheres are in the conjuint ratio of their magnitudes and densities; or of the cubes of their diameters and densities; it is By ae on 2 a ee Pe ks en 7 or * 2. 2 he = that is the forces retarding spheres penetrating uni- formly resisting substances are as the absolute strengths of the fibres of the substances directly, atid the diameter and specific gravities of the spheres inversely. Q. E. D.z Lemma U1. Law of the. The whole Spaces or Depths to which Spheres impinging depth to which te tall wile pem on differently resisting. substances penetrate, are as the netrate. Squares of the initial Velocities, the Diameters and speci= fic Gravities of the Spheres directly, und the absoluté : ~ Strengths of the resisting Substances inversely: or - 2 Nog De | ee) Ooh R- | gc ngs i Proof. .- For by mechanics ata Pd Ze; and by the pree 2 ap: D one ceding Lemma F-R* 7 *F therefore by sub- : 4 he D N r stitution ~— = > xX rat x ay x R° CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEAo 83 These being premised, I now proceed to resolve the fol- lowing important ProspiEM. ‘To find a general Formula, which shall express the Charge of To find the 4 ° charge of peWe Powder for any given Piece of Artillery to produce the deri: ce HAE greatest Destruction possibie to an Enemy’s Ship ‘at Sea; do most exes _ Gt being supposed of Ouk Substance of given Thickness, tion. and at a Distance not affecting the initial Velocity of the Shot. i By the last of a foregoing lemmata we have generally Vi= ‘Cae ) . Also the charges of powder vary as sDNr the squares of the velocity and weight of the ball jointly. Hence, since it has been determined from ex periment, - that a charge of half a pound impelled a shot weighing 1b. with a ely of 1600 feet per second; we shall, considering V the velocity of any ball imping’ng on the side of the vessel, have for the expression of the charge impelling it SRdnv*w through the space NS) = 2DNrs i600°° Now to apply this in the present instance it is first neces- sary, that a case be known concerning the penetration of a given shot into oak substance. Sucha case is presented at p. 273 of Dr. Hutton’s Robins’s New Principles of Gunnery. It is there ascerted, that an 18 pounder cast iron ball penetrated ‘a block of well seasoned oak (such as ships of war are genes rally built with) to the depth of 33 inches when fired with a velocity of 400 feet per second. Making therefore this the standard of comparison for all cases where the object i is of oak substance, we shall have for the charge generally, 400? xX °42 SRnw omar 1600* x gy NG or, because the balls are of the same specific gravity, and the substance the same, or R= 1, and N = ‘nz; it will be 400” xX ‘AQ Sw Sw eae wn aa ome tli ees ere) eG), nee 2x 1600° xy, * Db i oD G2 that~. 84 Example CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEAe that is, the charge varies as the space to be penetrated and weight of the ball directly, and diameter of the ball inversely. But the charge by the problem being to produce the greatest effect possible in the destruction of the vessel; $ in the above formula must always be put equal to the given thickness of the side; since it is well ascertained, that, for a shot to produce the most damage to any splintering ob- ject, such as oak; it must lose all its motion just as it ceases to be resisted by the object, which happens when the ball has forced its first hemisphere out of the farther surface ‘of it. And the quantity of motion destroyed during the penetration of the first hemisphere of the ball into, and the exit of the same out of the object is precisely equal to what would be destroyed during the penetration of the ball | through ‘one of its radii, if the quantity of resisting surface was equal to half its entire superficies. Hence the charge in question will be xe 045 xX D ‘ S being the thickness of the side of the ship; w the weight of the ball; and D its diameter. a EXAMPLE. Ab enemy’s ship isin sight: required the. charge for the ; 42 pounder guns to destroy her as quickly and completely © as possible, when the ships have approached near to each other. ‘The side of the enemy’s vessel, a 74, being 12 foot thick of oak timber. 4 The diameter of a 42 pounder of castiron being = *557 feet ; we get Sw 4 xX 42 *04 ——- = “O04 ———- = 5 : ok oe 593806 Ibs or, 5ibs. 150zs. for the weight of the charge sought. 4 TABLE ¢ CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEA. 85 TaBLE Containing the various charges for the 12, 18, 24, 32, 36, Tables of ; aml : bg » 4 i, Charges fot and 42 pounder guns, for producing the greatest effect iM different all cases of close action: the substance or object being of guns for oak materials from the thickness of 1 foot to that of 5 feet than revularly ascending by 1 in the inches. ship’s side. Nature of Thickness of ‘the side of the vessel ordnance. We ptt lain, bf. 21m | Tt. ein. pounder, Ibs. | ibs. | lbs. Ibs. 12 1°439242 | 1°559178 | 1:679116 | 1°799052 18 | 1928571 | 2-089285 | 2249999 | 2-410714 ; 24 | 2°336650 | 2°531371 | 2-726091 | 2:920813 32 | 2830470 | 3-066343 | 3°302215 | 3-538088 30 | 3:061030 | 3°316760 | 3-571901 | 3°827038 42 | 3°393180 | 3°675949 {| 3°958710 | 4°241475 | 16 inches 17 inches | 18 inches | 19 inches Ibs. > Ibs. Ibs. lbs. 12 1°918987 | 2°038926 | 2°158863 | 2-278800 18 [ 2°571428 | 2°732142 | 2°892856 | 3°053571 24 — | 3°115533 } 3310254 | 3°504975 | 3-699696 32 | 3°773960 | 4-009833 | 4°245705 | 4-481578 36 [| 4°082173 | 4-337310 | 4°592445 | 4°847581 42 | 4°524240 | 4°800905 | 5°089770 | 5°372535 | 20 inches | 21 inches | 22 inches | 23 inches bs... Ibs. Ibs. Ibs. 12 2°398737 | 2°518674 | 2°638612 | 2°758547 18 | 3°214285 | 3°374999 | 3°535714 | 3°696428 24 | 3894417 | 4089137 | 4:283859 | 4:478580° 32 ‘| _4°717350 [ 4°953323 | 5-189195 | 5°425068 36 | 5°102717 | 5°357853 | 5:612988 | 5:863124 |: 42 | 5°655300 | 5-938065 | 6:220830 | 6:670262 - 86 CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SBA. “Nature | “Thickness of the side of the vessel. of ordn. ~ 24 inches | 25 inches | 26 inches | 27 inches Founder Ibs. | Ibs. ibs. Loe "12 2°878484 | 2°998420 | 3°118358 | 3:238292 18 | 3°857142 | 4:017856 | 4178570 | 4339284 24 | 4673300 | 4°868021 | 5.062741 | 5-257463 ie | 5°660940 | 5°806813 | 6-132685 | 6-368559 | 6123960 | 6:378306 [ 6633531 | 6-848668 42 | 6°786300 | 7 069125 [7 7851090 | _7°034055 Pie eee | ft. din. | 2ft. 5in. |. 2ft. Gin. oft. 7 im | ieee | Sapa | Ibs. | Ibe. pa 12 3°358228 | 3:476164 | 3:598100 | 3°718036 | 4°521340 | 4-682054 | 4849768 | 5003489 + | 5:452184 | 5646905 | 5°841020 | 0 036347 32 6504432 | 6°840305 | 7:076178 | 7°31205! 36. | 7143804 | 7398940 | 7654076 | 7-909212 42 | 7-917420 | 8200185 | 8 482050 | 8765715 to. Bal ae 2 ft. Gin. | 2ft.1oin. | 2 ft. 11in. =P me TBs | lbs, Nels pak ie 3-a370791| 3°957908 | 4°077844 ] 4°1967780 5104190 | 5324910 | 5:485024 | 5646338 18 brie Penh cea 6:425780 | 6°620510 | 6815231 32. | 7547024 | 7:783797 | 8:019670 | 8255543 |_ 8164348 | 8419484 | 8:674620 | 8.929756 cae | 9°048480 [ 9:331245 | 9°614010 | 9896775 3 ft. in. | af. 1in. | aft, ain. | aft. sin. Ibs. Ibs. Rese Pree | 4°317716 4°A37652 cay 557588 4:677524 3 | _5:807052 | 5907766 | 6-128480 | 6289194 —~ | 7009952 | 1 |. 7°009952 ]_7-204673 [_ 7:309904 | 77594115 -¢ Oo <4 8491416 [ 87 8°727289 | 8963162 | 97199035 os 86 | _9°184892 | 9-440098 | 9°605164 | 9:950300] 10°179540 | 10°462305 | 10°745070° [11027335 117027335 CHARGES OF GREATEST EEFICACY FOR ARTILLERY AT sEA. Nature | Thickness of the side of the a ey of ordn. | 3ft. 4in. {| Sft. Sin. | 3ft. Gin. | 3ft. 7in. pounder Ibs. parts of inches take such parts of the difference between the charge for the given number of inches and the next greater, and add them to the charge first found for the given number of inches for the charge required. : ) The value of the decimal part of each will be had by multiplying it by 16, the number of ounces in a pound, and pointing off inthe product trom the nght hand towards the left as many places for decimals as are coutained im the given decimal, ard retaining the pumber on the left of the point for the ounces, increasing it by 4, 3, 3, or 1, when the first figure of the decimal is 2, 5, 7, or 8, respectively. This hint is merely given for those practitioners into whose hands this table may fall, who are not very conversant hy decimal arithmetic. Scnonun. j CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEAv 89 : ScHoLium. This problem is not only of the utmost importance, and The problem practically useful in naval engagements, but in several in- *Pplicable to military as wl stances also of military operations; as the bursting open as navai opera- gaies of besieged cities with promptitude and effect, and "ns. breaking ‘up al fortifications composed of wooden materials, especially those of a splintering nature, to which the fore- going charges apply most correctly. In the case of a uaval Advantage of action, where the object to be penetrated is of oak sub- 2 proper charge in a stauce, the ball, by having a smail motion when it quits the seafght, ship’s side, tears and splinters it excessively, breaking away large pieces before it, which are not so easily supplied in the reparation, whereas, on the other hand, if the shot had any considerable velocity when it quitted the side, the effect and disadvan- it produced would be merely a hole, which would be stop- tage of tou i - ; : much powder. ped instantly by the mechanic employed for that purpose ; and indeed in a great measure by the springiness of the wood itself; for 1 have seen in his Mayesty’s dock-yard at Woolwich, captured men of war having a number of shot holes in them almost-wholly closed by the wood’s own efforts; and that required nothing more than a small wooden peg or a piece of cork to stop them up per- fectly. All the mischief therefore the balls can do under such circumstances of extreme celerity is, merely killing those men who may chance to stand in the way of their motion. ‘ If any object to be destroyed be so thick, that it cannot Cases of be completely pierced by any common engine; or if it be ‘Ricker sub- _ of avery brittle nature, such as stone or brick; then that Piss of bc, charge is to be used, which will give the greatest velocity to walls. . the shot, to produce the greatest effect. But in many cases of bombardment this charge is by no means to be preferred; for though the effect produced each individual time be greater, yet in any considerable time the whole efiect would —beless than that from a smaller charge oftener fired, account of the extreme heat it would give to the bdand after a few discharges; and in consequence of which greater time would be required for cooling the gun, and preparing it for farther service. EXAMPLE 90 ‘@HARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEA. Ne ExaMPuLe If. Case afburst- Required the charge for a 24 pouuder shot to burst open ingopena — the gates of a city with the greatest ease possible,’ the gate with a 24 pounder. °~ gubgtance of them being elm 1 foot thick. Here the object to be penetrated being elm, the small letters in the general formula for the charge : Sdv*w 2Ds X 1600% must be made to express the several numbers of some ex- periment made tn the penetration of this substance. Now by a mean of many yery accurate experiments made. by, Dr. Hutton at Woolwich, in the years 1783, 1784, and 1785, he found, that a cast iron ball of two inches diameter impinging perpendicularly on the face of a block of eim- - wood, with a velocity of 1500 feet per second, penetrated 13 inches deep into, its substance; hence we shall have d z= ift, v = 1500, and s = 13 ft.; also by the question S = 1h. De Ae. anmvar = 24lbs. Therefore — 4 Desa eo Ve os oe 2) eee ae 2D x 16907 ~ 2x "46 x $3 X.40007 ~~ 104% PI == 3°50a31 Ibs. or 3 lbs. 8102s. for the weight of the charge / * xegnired in this case. Retaining the experiment of Dr. Hutton as a standard for all cases where the object to be penetrated is of elm, we aly! Hi get by reduction ‘ Sdv’ w = +0676: x Sw 2Ds x 16007 D the charge for any piece cf artillery the diameter of the shot of which is D, and weight w; 5, being the thickness of the object as before. 4 gate may be }t is not unworthy of remark, that the yate of a besieded dapst by the place, or any likethings, might be effectually broken open xerih 4 by the gun itself charged only with powder, by placing it 3" close to the gates with its muzzle from them; the momen- tum of recoil being generally suihcient to. farce such ob- jects completely. OF erat ia- ram the civgumstance, that no English admiral or come portance in mander ever commences firing till his ships are-about to be glose, fig h tug 4 srappled CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT SEAL oi grappled with those of theenemy,or until they have approached them so nearly as to affect in no sensible degree the first force of the shot; the above paper has, it is presumed, as much claim to utility.as any that has ever yet been offered to the navy in the science of gunnery: and evenif the vessels be not so closely in action, but are fighting at the distance of about 30 or 40 feet from each other, no danger would result from the above charges, provided that the shot impinged perpen= dicular'y on the side of the vessel; on account of the split- ting of the timber in some degree, which would make ample compensation for the defect of velocity occasioned by the resistance of the medium. It is impossible to deduce charges, that shall produce Distant Arne.. with certainty the effect above stated when fired at any considerable distance from the ship. The uncertainty of the impact bemg perpendicular from the unsteadiness of the vessels renders the thing at once nugatory, withont any consideration of the real resistance of the medium te thé -ball, and the deflection of ‘the latter from a right lined di- rection. If the obliquity of the impact be given, or can be determined, then, the problem being otherwise nightly solved, a charge can bé founc, which shall answer the same purpose as those above given; but, if this be iinpossiblé (which it most decidedly is), then will the problem be at best bat speculative upon certain hypotheses. — I shall however give an investigation of the problem on the principles of resistance generally allowed, and then con clude the subject by a few observations, Propiem IL To determine the same as inthe last Probiem, when the Engine To find the is at any considerable Distance from the Object, and 28° thst shall do mott the Resistance of the Air taken into the account. execution at 2 distance. Here, as in the former proposition, the Velocit v = prop ns 2 4G ge a is to be esteemed the velocity of impact. Now oa the Fite of resistance just adverted to, whrch considers the fluid as infinitely compressed, aud the particles thereof . ~perfeetly 92 CHARGES OF GREATEST EFFICACY FOR ARTILLERY AT 8EA. perfectly nonelastic and affording no resistance to the body but what arises from their inertia. If a denotes the first or initial velocity ; 2 the distance of the gun from the object ; ¢ = 2°71828 the number the hyperbolic log. of which is unity; and 6 = ar where N and n represent the re- spective specific gravities of the ball and medium, ‘we shall have bx 4 Vere (See Dr. Hutton’s elegant Exercises on Forces, Prob. 31, and most works on fluxions and mechanics). Hence by the law of variation of the charges, and proper substitution, the true expression for the charge in question will be - SNE) Sdv’we 4ND 2 Ds 1600* — for a perpendicular impact, and 3nz Sdv*we 4ND 3 Ds i600? > for an oblique one; / being the sine of the angle of inci- dence; the space to be described in this case being the hypothenuse of a right angled triangle; when the effect is the same, EXAMPLE. Charge for a Resuming the first of the foregoing examples; what must aie be the charge of gunpowder to cause the shot to produce tance. the same effect in the vessel when fired at the distance of 300 feet from it? Substituting for the several letters in the general expres- sion for the charge . 3nx Sdv¥we 4ND 2Ds 16007 their proper numerical values, namely th P ON THE MOTION OF ROCKETS. Hence not only is the destruction of the vessel more cer- tain when the firing commences just as the ships touch each other but a great saying of powder takes place beside, insomuch, that not more than two thirds of the quantity is expended, that would be required at the distance of 300 - feet. From this circumstance then, and the eonebiien, af solving the preblem rightly from the various causes already enumerated, the effects of which are not reducible to any regular laws; we conclude, that the foregoing table of charges for ‘close fighting is the only one, that can be of the smallest service in practice, and that all attempts at others must be rendered completely futile from the nature and constitution of things. Doeccaeeae a eecr ee ee ease SS aE SaaS If. Correction of an Errour in a former Paper on the Motion of Rockets. By W. Moons, Esq. In a Letter from the Author. To Mr. NICHOLSON. SIR, I TAKE the earliest opportunity of correcting the errour so obligingly mentioned by Zeno in the last number of your Ss = 12 ft. SRE s = 4a ft Sdy?we 4ND aa 2 ft. ‘we get MMS a ee ae D='557 ft. 373%, 1000 v = 1500 ft. >9°530695 lbs. or glbs. 82ozs. nearly for x = 300ft. | the weight of charge sought; being, w = 42 Ibs. 3 Ibs. gt ozs. morainehic case than when N= 7+ the vessels are in close action. w = :0012 93 Journal: into which 1 ‘inadvertently fell in my paper con- On the mo- cerning Rockets for July last. Miah chive QR and K n (PI. 8, fig. a erased from~ the diagram, and QW drawn perp. to T produced in the plane TQ W; aiso, draw WR perp. to TP and join PW which will be pero. to TW. Then calling T P unity, TQ will be = f (the same substitution for the several angles remaining as bef ore) 3 3 also sine Z TQ W being ouocr by = by Trig. TW = eae : hence P W (TT Pp? TW}* tion of rockets e 94 On the mo- tion of rockets, ie ON THE MOTION OF ROCHETS. By. x a (1 * he Sy i Cae if a”) % Tame : r? 7 7 3 case is equal to the sine of the angle PTW or PWR. Now because of the oblique action of the fuid against the cylinder, (considering the fluid in motion, and the solid at rest) its force on this account wili be diminished in the ra- tio of radius to the cube of the sine of the angle of incidencé, or as 1 to f%. © Therefore considering T P the representative if ie at Ee of the force of a particle so diminished bei i )3 : which in the present Ag its efficacy to move the cylinder in direction P T no f3 mite vill be PR and = Fr 5 Sine LPR, r zm or it 5 re fs iy fed sh dake ale sete f Rai ~ (r? — f* 2). Therefore 4g r Agr? “the fluxion of the force of the fluid on F T will be Zz PY, seu es by? xs f® o®)* Semone. Te Per ey ee 4 (r? Rava ia lad : nt or 3 ner f3 “ “ Cr” —f* at) 4 gy A zis) Ca pV the fluent of which 1S \ Rev mee 4 > 3 f?—1 "4 Bi Ae ee ng “Agr? . (r x Pg ee — J -- gr i i ie” . 5) 2A ae -- : 119 os x7 +- &e.): which when x = 7 2 BTL Sapo Bil Tie okt) teh a Re eR Sah eae PR) Uae ; call ag. | 6 y a + 5)» (fi Riel ) | a “ a is + &c.). This therefore is the effective force of the fluid on the quadrantal arch F’TS., Hence the force on the whole semicylindric surface m DerBs Oe ie . Api ie — ne rhf (1 — $f? —1 4 3 (f? —1)? oes 2g : 6 40 2 BN Py oss) 1)2 : 5 : : . lee + ke. ) which is also the res sistance to the cylinder when this moves.in the fluid at rest, as fur as relates to that surface, Q. E. I. yh. Yours, &c. < W. MOORE. NEW PROPERTY OF REFLECTED LicuT. O5 IIL. On a Property of reflected Light: by Mr. Manus’, W HEN a solar ray is reflected, dr refracted; it retains pede o: in general its physical properties ; and if it be subjected to refracted rays 1 f generally simis new trials, it comports itself in the same manner, as if it j.45 direct; issued directly from the luminions body. The prism, while it disperses the coloured rays, only changes their réspective directions, without altering their nature. There are cir= tutiotalwa¥e; cumstances however, in which thé influence of cértain bodies im presses on the rays they reflect, or refract, characters and properties which they carry with them, and by which they are essentially distinguished from direct light: _ The property of fab I am about to decane isa modifi= Bouble 7 cation of this kind. It had already been perceived in a fraction. particular circumstance of the doubling of images exhibited by calcareous spar: but, the phenomenoii resulting from it having been ascribed to the properties of this crystal, ito one suspected, that it migtit be produced, not only by all bodies that afford : a double refraction, but by all other dia= phanous substances, whether solid or liquid, and even. by »pake bodies. . Tf a ray of light be received perpendicularly on the face A ray of light - of a rhomboid of calcareous spar, this ray is divided into Teceived on ; ‘ i eee f th ‘a i} Iceland crystal two pencils, one continued in t e direction of the incidental ;, gividea ints rays, the other making with it ab angle of a few degrees, The two. plane that passes through these two rays has sbleral peculiar Plane of thé _ properties, and is eited the plane of the principal section: principal hae Tt is always parallel to the axis of the integrant particles cS deny hed of the crystal, and perpendicular to the natural and artificial refractive surface. When the incident ray is inclined to The says as the refractive surface, it is equally divided into two péncils; piace hee one refracted according to the ordinary law, and the other oe inal according to an extraordinary law, which depend on the angles that the incident ray forms with the refractive sur- face and the principal section. When the face of emergence ‘is ‘parallel to that of incidence, the two emergent rays are * Méin. dela Soc. @ Arcueil, vol. I]; p» 143, : ¥ ' parallel 96 The two rays received on another crys- tal are not di- vided, when their principal Sections are parallel. But by alter- ing the posi- tion of one of the crystals they are di- vided, and again re- duced to two. NEW PROPERTY OF REFLECTED WIGHT. parallel to the incident ray, because each ray undergoes the same kind of refraction at thé two opposite faces. If now we receive oa a second rhomboid, the principal section of which is parallel to that of the first, the two rays that have already passed through this, they will no Jonget be divided into two pencils, as rays of direct hight would. The pencil from the ordinary refraction of the. first crystal will be refracted by the second according to the law of the ordinary refraction, as if this crystal bad lost the faculty of doubling images. In like manner the pencil from the ex~ aaah vercactine of the first crystal will be refracted by the second according to the law of the extraordinary refraction. Tf, the first crystal remaining fixed, we turn the second so, that the face of incideace shall remain parallel with itself, each of the two rays arising from the refraction of the first crystal begins to divide itself into two pencils; so that one portion of the ray from the ordinary refraction, for example, begins to be refracted extraordinarily, which produces four images. Finally, after a quarter of a revo- lution, the pencil from the ordinary refraction of the first crystal is entirely refracted extraordinarily by the second; and, vice versa, the pencil, from the extraordinary refrac- tion of the first crystal is wholly refracted according to the ordinary law by the second; which again reduces the . number of images to two. This phenomenon is independent Distinction between direct * and refracted light. Light affected in the same way by all double refract- img substances, of the angles of incidence, since during the movement of the second crystal the refractive faces of the two rhomboids preserve the same inclination toward each other, - Thus the character that distinguishes direct light from light that has been subjected to the action of a crystal is, that the one constantly possesses the faculty of being: di- vided into two pencils, while in the other this sandal de- pends on the angle comprised between the plane of inci- dence and that of the principal section. This faculty of altering the character of light, and of im- pressing on it/a new property, which it éarries with it, is not peculiar to the Iceland spar: I have found it in all known substances that double images; and, what is re- markable in this phenomenon, it is not necessary for its ‘ production, a a eae, NEW PROPERTY OF REFLECTED LIGHT. O7 production to employ two crystals of the same kind. Thus the second crystal, for example, may be carbonate of lead, or sulphate of barytes’; the first may be a crystal of a sul- phur, and the second of rock crystal. All these substances comport themselves with one another in the same mannet as two rhomboids of calcareous spar. in general this pro- pensity of light to be refracted in two pencils, or in one only, depends solely on the respective positions of the axis of the integrant particles of the crystals employed, be their chemi- eal principles what they may, and of the natural or artificial faces, on which the refraction is produced. This result proves, that the modification light receives from these dif- ferent substances is perfectly identical. To render the phenomena I have described more sensi- Method of ble, the fame of'a taper may be viewed through two prisms be the of different substances, possessing the property of double arte eal refraction, placed on each other. In general we‘shall per- ceive four'images of the flame: but, if we turn one‘of the prismas ‘slowly round the?visual ray as an axis, the four images will be reduced to two, as often as the princi= pal sections of the contiguous faces become parallel, or eut- each other at right angles. The two images that diss - appear do not lose themselves in the other two; we perceive them) kt cee become extinet, while the other acquire Increased intensity. When the two principal sections are parallel; one of the images is formed by rays refracted in the ordinary way by the two prisms, and ‘. other by rays refracted extraordinarily. When the two principal sections are perpendicular, one of the images is formed by rays refracted ordinarily by the first crystal, and extraordi- narily by the second; and the other by rays refracted extraordinarily by the first crystal, and ordinarily by the second. ; Not only all crystals, that double images, are capable of Light affecte | giving light this faculty of being tefr acted in two pencils, vai on erin one only, according to the position of the refractive ‘iaodheae crystal; but all transparent bodies, whether solid or liquid, bodies, and even opake bodies themselves, can impress on the lumi- eats nous particles this singular disposition, which seemed to be i one of the effects of double refraction. Vou. XXX.—Ocr. 1811. io . ~ When » 98 Partial reflec- tion from transparent bodies. NEW PROPERTY OF REFLECTED LIGHT. When a pencil.of light, traverses a transparent substance, a. portion. ef the rays is reflected, by the: refractive, surfaces _ and another-portion by the surface of emergence. The cause of this partial reflection, which has hitherto escaped. the researches of natural philosophers, seems, in several circum, stances, to have some analogy with the forces SuahRtgd ss * the double refraction... , la From water. The reRected., ray received on a double yefracting crys: 1 tal, This pheno- meiion ana " lysed. For example, light reflected by the anthenes of. water underan angle of 52°43’ wath the perpendicular has all ‘the characters, of one of. the peacils, produced, .by, the, double refraction of a crystal of calcareous spar, .the principal section of which is parallel or perpendicular, to the plane, that passes through the. incident raypand . the, reflected r9¥st which weshall call the plane of reflection. .1. .. Lf this reflected ray.be received on, any, cool abit ee the, property. of doubling images, and the principal. Section of whichis, parallel.to the plane of, refleciion;. it, will not bes divided into two pencils, as aray of direct light. would). haye been } bat it will be refracted entire according to the ordinary. law,, as if.the crystal had lost the fuculty. of doubling images, . If, on the contrary, the,principal section of the crystal be perpendicular to the plane of,-reflection, the reflected ray will.be, refracted entire according to. the | extraordinary law. In the iatermediate. positions it will be divided into two pencils according to the same law, and in the sane proportion, as if ithad acquired.its new character by. the influence of the. double refraction... The ray. reflected by the surface of the liquid therefore, under this circum stances; has all the characters of an ordinary ray formed by, a crystal, the principal section of whichis perpendicular to the plane of reflection... ; : -To analyse this ; phenomenon aaanieren [ placedyy a crystal so that its principal section was vertical; and. after having divided a luminous ray by means. of the double re- fraction, I received the two pencils propeeding from it on the surface of water, at an angle of 52° 45’. The ordinary ray, in being refracted, gave up to the partial reflection. a por- tion of its particles, as a pencil ef direct light would. shave. done ; ; but the extraordinary ray penetrated the liquid en- tire, and none of its. particles escaped refraction... On the, Se $4 if ‘contrary bs NEW PROPERTY OF REFLECTED LIGHT. | 99. contrary, when. the principal section.of the crystal. wag, per= peodicular to the plane of incidence, the extraordinary ray produced. alone.a. partial reflection, and the ordinary, ray was refracted entire. | - . The angie under. which ae experiences this modifica- Different bo- tion in being reflected at the surface of, different. transparent San bodies is not, the/same in.all.,. In general it is greatest indifferent ans those that refract light most. ‘Above jand below ve angle eles: a, part of the jrayis more, or less. mudived, and. in a manner analogous. to) what takes place between two. crystals, the: . etusips! sections of which cease to be parallel or meapendi cular. ¥ é “If we would fies observe this: Dateien: widilout ede kts measuring it-accurately, we have only to place before Ea al taper the transparent body, vr. the vessel. containing, the liquid to be subjected to experiment. We must. ,then observe through a prism of flint glass the image of the flame | reflected at the surface of the solid or the liquid,.and. in general/two images will be seen: -;but.on turning the crystal round the visual ray as an axis, one of the images will be seen to grow faint in proportion as the other increases in, inten- sity. Beyond,a certain limit, the, image. that. had grown, weak begins to renew its intensity at the, expense. ae the second, .At the. point where the. intensity of ,the light is. nearly a minimum, we must move the reflecting body nearer: to the taper, or farther from it, till the angle of incidence is . such, that one of the two images wholly disap Hears. | This: distance being found, if we continue to turn the prism, slowly, we shall perceive, that one of the two images bes , comes extinct: alter vately at every quarter of a revolution, "The, phenomenon I have mentioned in the rays that are The phenome- reflected under a certain angle at the surface of a transpa- a makes: * rept body takes place likewise, but under a different angle, Dae with the pencils, reflected interiorls by the surface of emerg- the interior of ence; and the.sine of the first angle is to the sine of the Ageia second as. the sine of incidence to the sine of refraction. Thus, if we suppose the face of incidence and the face of emergence parallelto each other: and the an gle of incidence such, that the ray reflected at the first surface presents the Papteaierodt Lhave described; the ray reflected at the ee ng eg second 100 NEW PROPERTY OF REFLECTED LIGHT, secoud surface will be modified in the same'manner. If the inicident ray be such, that all its particles escape the partial reflection and ‘pass through the face of eutrance, they will equally escape by traversing the face of exit. This new property of ‘light affords the means of ‘measuring with’ pre- cision the quantity of rays absorbed at the stirface of diapha-_ ay nous bodies, a problein, which the partial reflection tendered | alinost impossible to be solved. : Light reflected “Whe a body, that produces a double refraction, reflects from the sur- the light at its first surface, it edmports itself like a com=* mion transparent sttbstanée. The light reflected tinder a cer: fricting body. tain angle of intidence acquires the property I have de=» face of a doubly re- scribed # afid this anglé is independant of the position’ of the principal section, which influences only the’ double re- - fraction, or the reflections that take place in the interior of the erystal. 24 Rays reflected ~Ynrfaet; the rays that are veebtcl interiorly at the second interiorly ex- stirface exhrbit peculiar phenomena; which depend both on: the réfractive power, ‘and’ the properties. pfs sie ief Hess hibit peculiar phenomena. iliat I have already described. When‘a pencil of light hus been: mined * into two rays at the first surface ofa rhomboid ‘of calcareous spar, these two rays issue out by the second face in two pencils parallel to the incident ray, because each of them experiences at that face the same kind of refraction as at the first face. It is not the same with reflected light. Though the ray re= fracted ordinarily at the first suriade t is refracted crite (ty ‘at the'second, it ts nevertheless reflected at this surface in two pencils, one ordinary; the other extraordinary. In like inanner the ray refracted extraordinarily is reflected in two others; so that there are four reflected rays, while there are but two emergent. These four rays, in returning to the 6 first fate of the crystal, issue out in four paraltel Pencil, which make with this face the same angle as the incident ray, but in a contrary | direction; and are parallel to the plane of incidence. To connect this kind of reflection with that of double refraction; we must conceive at the two points of emergence of the second face two incident rays, making with ehte face the same angle as the emergent rays,’ a in iy opposite direction. These two rays, by their res” fraction NEW PROPERTY OF REFLECTED. LIGHT. 1D1 fraction through the crystal, will produce four -pendils, \ which will follow precisely the course of the reflected, rays. Thus the law of the double refraction being kriown, that of the double reflection may easily be deduced from ite’ ~Ishall new proceed to that kind of phenomenon, which Quantity and , is the subject of this paper ; and which. relates, not,to ‘the properties of law according to which the rays are directed, but.to: the oe iene quantity and properties of the light they coutainy Let us suppose the angle of imeidence to be constant, and the crystal placed henzontally. If we turn the rhom- boid round the perpendicular, so as to approximate its -prin= cipal section to the incident rays, we shall perceive a gras dual diminution of intensity in the ordinary ray reflected extraordinarily, and of the extraordinary ray reflected ordi- y narily. In fine, when the plane of the principal section: coincides with the incident ray, theseitwo reflected rays disappear entirely, and nothing remains but the ordinary ray reflected ordinarily, and the extraordinary ray’reflected extraordinarily. The latter however has much less intensity 3 than the fornier. If now, the incident ray continuing to be included. in the principal section, we increase or diminish the angle of incidence, till it becomes 56° 30’, the latter reflected ray will disappear altogether; and only that, which has been ~yefracted ordinarily, and reflected ordinarily, will remain. Beyond or within this angle, the extraordinary ray reflected extraordinarily will reappear with an intensity proportional to the remoteness from this angle. The angle of incidence Ihave mentioned is that, under which a ray reflected at the first surface would have acquired the property of bemg d= plage vided into two pencils, or remaining in one, as takes place at the surface of any other transparent body.) The pre= ceding phenomenon may easily be connected with» the expe+ riment, in which water was taken for an example: for if we Jet fall on the surface of the rhomboid, under an: angle of 56° 30’, or'thereabout, a ray’ disposed to be refracted only in one extraordinary pencil, this ray will produce!no partial reflection at the first surface; ee seems to explain, why it produces nonéat the second. Howeyer, itis not the same, me the plane of incidence VE makes ? 102 the partial re- flection of opake bodies. Refiection from metallic Mirrors. NEW PROPERTY OF REFLECTED LIGHT. thakes.a sensible angle with the principal section. Tf the ray just mentioned be: made to fall in this:plane, under an angie of 56° 30’, or nearit, it will comport itself at the first surface as in the preceding case, it will traverse it without any reflection: but at the second surface it will be reflected in two pencils, which will attain ‘their maximum of intensity, when the plane of incidence is perpendicular to the principal section. i ) It is obvious, that the light reflected at the second face does not comport itself here asiu the preceding case, be- cause in the first experiment the incident ray refracted and reflected is still in the same plane, while in the last the repulsive force, that produces the extraordinary refraction, turns the light away from the plane of incidence, so that it ceases to. be similarly. circumstanced with mepact to the forces that act on it. ’ If we examine the light that proceeds from. “mt partial reflection of opake ain as black marble, ebony, &e., we shall equally find an angle, at which this light gujeys the properties of that which has traversed a crystal of Iceland spar. Polished’ metals appear to be tbe only reflecting substances, that do not seem. capabie of ‘producing this phenomenon: but, if they do not. impress this peculiar disposition on luminous rays, they do not alter it, when they have already acquired it by the iufluence of another sub stance. ; ioe This property is preserved also by pencils, that traverse substances which refract hght singly. In the second part of this paper* I shall describe the circumstancesy-uuder which, _by means of reflection’ from metailic mirrors, the mutual, disposition of the particles of a ray, either ordinary or extraordinary, may be so changed, that some shall always be refracted ordinarily, while the others are refracted extraordinatily. The examination of these different circumstances. will lead us\to the law of these phenomena, which depends on a general, property of the repulsive forces that act on light. sui ono pS) oO * This will appear iv our nextso@yiou one | S913! MM reals 4 wy : cies mR MR i fo EM 4 - wie ; sch ‘ ¢ a Bi aE clIVOWOEk IV, TRANSMISSION OF SOUND THROUGH LONG TUBES. 103 4 : IV. pasate on the Transmission of Sound through solid ’ Bodies, and through Air. in very long Tubes: by Mr. » Bror*. Ir has long been known, that air is not the only medium, Sound pro- in which the phenomenon of sound may be produced and pint ahs? i transmitted. All bodies enjoy this ‘property, when they other bodies enter into a vibratory motion: and as, even in the. most beside air: solid substances, the elasticity of the ultimate particles ap-_ peats to be extremely great, it follows, that sound may be produced and transmitted in all bodies, when they are suit- ably agitated. This result is confirmed by a great uumber ‘of daily observations. The miner, when excavating his as the ground, gallery, hears the strokes of the miner opposed to him: and thus judges of his direction. Stoae, wood, metals, and even water, transmit sound: and Franklin assures us, that water, he has heard under water, at the distance of half a mile, the sound of two stones struck against each other. Several too have observed, that the velocity of sound is much greater in solid bodies, than in the air. Experiments of this kind 4 wire of 600 were made in Denmark on a wire extended horizontally’ 600 feet. A piece of sonorous metal, suspended from one extremity of this wire, was struck gently; and a person at the other extremity holding it between his teeth, or ap- plying it to some solid part of the organ of hearing, heard two distinct and successive sounds. The first and most rapid wastransmitted by the wire: the second through theair :’ and from their interval, compared with the known velocity of” sound in air, it was found, that the sound transmitted by the metal arrived almost instantaneously. These experiments’ were repeated in England by the Royal Society, and si- milar results were obtained, but J'do not know the precise quantities found. Mr. Hassenfratz ‘too’ made experiments Experiments .in stone quar- on’ the same subject in the shaguipos,s at Paris, with Mr. ‘Gay? Thies. q * Mém de la Soc. d’Arcuell, vol. I, Pe 405. ‘Read to the Institute’ “oie 1808. yey i Lussac. 104 None of these show the pre= cise velocity in solids. Attempt to ascertain it by their vibra. * tions. 16 or 17 times as great as in air. TRANSMISSION OF SOUND THROUGH LONG TUBES., Lussac. A stroke of a hammer «gainst the side of the galiery produced two sounds, which separated at a certain distance, and that transmitted by the stone arrived first, This separation too was observed, when the sound was transmitted through iron bars, or wooden rails of different lengths, and no perceptible interval could be distinguished between giving the stroke and hearing the sound. All these experiments are well adapted to show the great velocity, with which sound is conveyed through solid bodies, but they were made on lengths not sufficient to afford a measure of this velocity, or even to give a precise idea of it, An ingenious philosopher, whom we have now the pleasure of haying at Paris, Mr. Chladni, author of some very fine. experiments on the vibrations of solids, has proposed a. method of estimating the transmission of sound through their substance, It consists in causing a rod. of. any sub- stance, of a given length, to vibrate by friction: when the tone produced by the rud, compared with that of a column, of air of the same length, will give the ratio of the velocities of the transmission of sound. through air, and through the anbstance of which,the red is for med. In fact, we readily perceive from the theory, that the velocity of the longitus dinal oscillations of a body and that of the sound trans- mitied through it are proportional to one another: but itis necessary to be certain, that the whole rod vibrates so as to. give its fundamental note, without dividing itself into. its aliquot parts: for such a separation, heightening proportion, - ally the tone, would give a velocity of sound proportionally. aboye the truth. Im this way Mr. Chladni found, that the velocity of sound in certain solid bodies is 16 or 17 times as great as in airs The most elastic substances are irony, and fir with very straight fibres, when, itis rubbed longitu- Experiments made in the aqueducts forming at Paris; dinally.. The construction of the Baedets he conduits, high, is at, present carrying on for the embellishment of the.capi-+. al, .has furnished me with means of making experiments. of this kind on a much greater length, than any of those who have gone before me have had at their disposal. It was besides. a subject of; curiosity, | to, learn the effects and reach a of the human veice ia very long ‘cylindrical tubes. Such;. ‘ were, ~ TRANSMISSION OF SOUND THROUGH LONG TUBES. 105 were the. objects of the following experiments. Some of them were rhade by Mr. Bouvard and me, others by one of us alone. Mr. Malus, colonel of engineers, was likewise present at many of ihem. In all of them we were assisted by Mr. Martin, maker of nautical watches, a very ingenious -and-attentive artist, who was particolarly appointed to give instantaneously, at. determinate seconds, the stroke that was to produce the sound. The souorous body, on which we operated, was formed by which consist a series of cylindrical tabes of cast iron, of as equal di- of a ianries of iron pipes, mensions as. possible, and the mean length of which I found tobe 2°515 met.* | [8 feet 3 in, nearly]. This [found by mea= suring the whole length of twelve e cylinders placed end to end, The tubes are separated by leaden rings covered with — tarred fustian: but they are pressed together by strong screws, so that the rings are forerbly compressed, and 86 close ‘a contact pruciced, that no water can éscape, The mean thickness of each ring 1s 0014286 met. [0°562 of an inch], as I found by méasuring twelve, The-whole series of chlinders forms a carved line, which has two inflexions about the middle of its length: but they were not all joined together tat once, and we made our experiments on different aan lengths, as will be seen in my report of them. ©The first were made by Mr. Bouvard and myselfon 78 ist set of exp. cylinders, forming a length of 196'17 met., to which must Anse be added 14:4 for dhe 77 rings, giving a total length of yards. 497-27 met. [215°587 yas]. The etnehe were Ape weal nomena we observed. °¥n the last cylinder was placed a ring S68 iron, of the’ Apparatus. game diametér as ihe éylindér, and having? i in ‘its centre a bell ‘withoat a ¢elapper, and a hammer that could be let fall < at, will. The hammer, as it struck, the bell, struck also. the cylinder, with which it formed a communication by means of the iron ring. Two sounds must therefore be peard; one tvansmitted by the ¢ylinder, the other by the’air. Mode of exe “Tn fact' they were’ ‘heard very distinctly by applying the perimenting. gar to the cylinder, atid even without this. They appeared ~#°AU ‘the® ‘iheasutes” emploved i in this paper ate expressed i in metres 5 qnasthe time in/seconds of ‘the sexagesimal divi ision, gensibly 106 TRANSMISSION OF SOUND THROUGH LONG) TUBES. sensibly in unison. The. first and. more. rapid was transs mitted by the substance of the cylinder, the second by the air. Strokes of a hammer on the last cylinder likewise pro- duced this transmission. We observed attentively with half second chronometers the. intervals between the two sounds transmitted. . We even employed successively sexae gesimal and decimal watches, to vary the numbers observed. Thus we found Ps A Tn 11 observations #s+erereeereceeees 0°527” ae velocity of the 22 eoceeeeveseonv,eese voecseaeceeese 0°555” ETS inher =. cae 20 reece ee cees ceeeeeceeceneres Was Bell. \ —_—— 53 observations. ’ ' Mean 0°542” —_—, The interval given by. the hammer, and by the bell, ap- peared to us absolutely the same, without any sensible dif- ference. For this reason we have united them in the.same mean. Their!tones however. were very different. Thus i in solid bodies, as in the air, the tone makes no difference in velocity of, the sound, Velocity of The temperature ‘of the air during eh experiment was EE 11°[51'8° F.]. The barometer was “about 0:76 [29: 9 in.J. solid caleue In similar circumstances the velocity of sound in the air is iared. 340°84 met. [372°487 yds] according to the experiments of the academy, which give 334°02 met. [365:034 yds] for the velocity under the same pressure, and at the temperature of meiting ice. For the distance of 197°27 [215°587 yds}. therefore, that at which the experiment was made, the time of transmission of the sound by the air was . «+++++ 0°579”. The interval observed between the two sounds was-+ 0°542” Difference, or time of its transmis. thro’ the metal-- 0°037” eB We do not pretend to give this small difference as exact,, | since the slightest errour would have a considerable influence ov it, but it proves, that the transmission was not absolutely, instantaneous. aah 7 % The second set of experiments.was made by. Merae Bou- : ward and Malus on twice the former number of cylinders, ora length TRANSMISSION OF SOUND THROUGH LONG TUBES.- 107 length of 394-55’ met: [431°184 yds]. At this distance ‘the length of 434 time of ‘transmission through air would -be 17158” by dann calculation, supposing the temperature still 11° [51°8° F.}. The interval) between the two sounds, deduced from 64 Interval, experiments, was found’ to be 0-81”... The. differenee Time of trans- therefore, or 0°348”; was the time of transmission through thiohee the > the ‘solid. This appears much too great, if we come solid. © _ pare’ it with the preceding experiments, and on ‘those Paw i that follow, which were made on nearly triple the length. great. The latter would not .permit’ us to’ suppose:a longer | time than 0°12§% for’the transmission through the solid, which would give: an: errour, of 0°223” | in |:the | observa- tion: But, beside that itis extremely difiicult:to answer for such quantities,/when the instant jof observation does not coincide exactly with a beat of the watch, it’ must be re- marked, that the whole length of the pipe! might be far from being at the same temperature, which might oveasion eurrents of air, that would influence the velocity of the sound. For instance, iu the present case, if we were to admit the transmission of sound throngh air as it results from the observations of the chronometer made by Messrs.: Martio and Bouvard at the points of departure and _ arrival, it would be found equal only to 1°07”, or 0-088" less than the ‘truth, which gives 0°26’dor the time of the transmission of the sound through ‘the ‘solid; and «the excess of this - result over those'that follow, being no more than 0-135”, is more easily reconcilable with errours of observation. + Finally, theexperiments now to be related were made by’3d set of expe- Mr. Martin and myself, on a series of 376 cylinders, which, ments, ona =e oe . ° ni length of 1040 with their joints, formed a length of 951-25 m. [1039°575 yds] yards nearly, of which ‘the joints alone occupy 561m. [6:13b yds]. 1 satisfied myself at different times, and by more than 200_ experiments, either with the hammer or the bell, ‘that the interval between the two sounds transmitted by the metal and by thevair,! was xexactly 2°5”;: and: Ifound no sensible variation'in; this duantity. .I made: Mr: Martin observe the interval also; without letting him knowimy results, and he found the ‘same. «Now, at ‘the ‘distance of 951-25 met: Interval. [1039°575 yds], the temperature beingel 12 [51°8° F.j,/ the aE time 108 FRANSMISSIQN OF SOUND THROUGH LONG TUBESs time of transmission of the sound: through the air would be from calculation 2°79”: aud if we substract from this 2°5”, the interval observed between the two sounds, there will remain 0:29” for the time of transmission through the me- tal to this distance. From the care with which I repeated ¥elacity cal- gulated, these observations, and from the exact coincidence of. the five beats of the half-second chronometer with the interval between the two sounds, I believe, that this result nay be considered as a very near approximation. Still however it may be objected, that the velocity of the _ sound in air deduced from calculation might differ a little As this indi- rect method ‘ might be queés- tioned, the velocity was measured directly. from what really took ‘place in the»pipe, owing to variation of temperature. This would, leave some uncertainty with respect to thé result, and particularly as to the precise quan- tity. Isought therefore to verify it directly in another way, and accomplished it as I shail relate. ' I stationed Mr. Martin at one extremity of the pipe with a half-second watch, while I remaiaed at the other with a similar) watch, which was carefully compared with the formerat the beginning and end of the experiments: though this comparison could have no influence on the results, as will soon appear. When Mr. Martin’s watch was. at 0” or 30”, he struck with a hammer on the last cylinder, near which he was stationed : and when my watch was at 15” or 45”, L answered him by a similar stroke. . We each watched: the arrival of the sound transmitted to us, and noted down the time, We were very attentive to strike precisely at: ‘the appointed second; and this, with a little practice, we — could readily do, as the series of our observations will show. Now, whatever the difference of the watches might be; and even if it ‘were yariable, proyided there was no sensible change in 30”; it would be reduced to nothing by taking the’ mean of two consecutive observations, and the result would be independent of it. For, Jet: ysi suppose the: first watch to he theiquantity 7 before’ the:seeond, and put p for the time. im which the sound is trausmitted: by ithe solid papa When the:first observer strikes.om his watch at 0”; ‘ithenother redds omuhis 0” Lr ¢.and eonsequently,p—r ins mentee iWefare| 6r fafter:.0”y -the-time at which he hears the TRANSMISSION OF SOUND THROUGH ‘LONG ‘TUBES. sound. On the other hand; when “thé second ’ observer strikes at’ 30”, the first observer reads 30” “4 e; and consea' quently p -+ 7 indicates,’ beyond 30"; thé'time in’ which the sound is transmitted to hitn.’ “The quantities p +r and p+r therefore are given by these isochronous observa= tions’; and half their sum immediately’ shows’ the time of transmission p, independant of ‘the -differénces betweeti the et and more “icc tha “by” direct obsérva- tion. - ; a ag . "In the experiments I made, the series of the: quantities , y sich se Pp 7 r “Nd as in the following: table. ne ; i Boa p+r “Sum, or * ot value of 2p. Rat series, from 04 52’ to 08 59°) 9" 4 995 085 i Wyo 8 Mel a SEE Ls iQ 2952 ~ QrSs fig 25 O'S > 2 bongs \:00FBy aa! , 2 \¥ 1 OS O"5 5 y ie) B5t Ose! eg as Hy Ling OE _ 8d séries, from it 27’ tothse’- 28, 3:5 OF Rave 5 2G daB5i; 058m , ER S77 Se OPES dp fh BOoo 35. 0°68 Bin ak 3:5. O53 P 3 35 OS | 3. 35 O85 Bids: | 39 35 06 Bios Gti DS 3 3:5. O85 S134 04 | Mein yalué of @ p. seeeoccs O52) Value of pees aieied suuie sidan 0:26. This differs only 0-03” from what we found above Fri the difference of the transmissions: but the last method, as it gives double thé quantity to be deduced, deserves the preference. If we add 0°26”, the time of transmission tir dGTi the’ solid; 109 \ i This ieafly agrees with the last caleus lation. 110 TRANSMISSION OF SOUND THROUGH LONG TUBES. solid, to the difference 2°5”-constantly. observed between the arrival of the two sounds, we shail have the. whole time of the transmission through the.air equal to 2°76", - This time, calculated from. the length of the pipe,. would have been 2°79, as has just been seen; and the agreement between these.numbers, which differ only 0:03”, appears calculated to inspire some confidence in the, results. Velocity in The time of transmission through the metal erie 2 0:26", cast iron more while that through air is 2:79”, it follows, that the transmis ge apse sion of sound, through cast iron,is 1075 times as quick as air. through air. If this estimation be not sufficiently, exact to determine with precision the ratio ot the velocities, it. is at. least enough to show of what kind this ratio is, and what idea we et ae torform of its): |, Bisel Other pheno- — In making these experiments we had an SHO ratty of | Tena ob- observing several phenomena worthy of remark with re- served. spectto the power with which sounds, even the faintest, are preserved and transmitted in tubes, to distances at which, we could scarcely suppose they wou!d be perceptible. Convetsation In> our first experiments at the distance of 1907 met easy through a [215 yds.] we heard each other so well through the length pipe of 215 wardae of the pipes that it was an inconvenience in the commence- ment, as the slightest noise “was transmitted fiom one ex- tremity to the other. It was not necessary to speak 1 into the pipe to'be heard,'as common conversation two yards from the end-was transmitted through it clearly; and in writing down’ my observations I asked Mr. Martin what it was o'clock by his watch,“as [ would have done a person only two paces from mes This mode of conversing with an invisible neighbour is so singular, that we cannot avoid being surprised, even though acquatated with the cause. Speaking loud 1n the experiments made by Messrs. Malus and Bou- heard 431 vard at the distance of 395 m. [431 yds.] they still heard spat each other, but with much more difficulty. It was neces- sary to speak very loud, and frequently to desire a repeti- At 1040 yds. tion of what had been said. Finally, in the last experiment, loud shouting which we tried at first together on a total length of 951. m.. ragenige [1040 yds.], the voice was scarcely to be Beare when shout- sound ofthe ing as loud as possible. The sounds of the bell and of the eal oD stroke of the. hammer were no Ipnech audible through ‘the air. TRANSMISSION OF SOUND’ THROUGH LONG TUBES. lll »The sound through ‘the metal alone.was: perceptibly at all through Hy alo seLastly,| though we could still hear the sound the ait. of the voice,.it'was not: sufficiently »clear for us to. distin- guish words, or to transmit the necessary: information after our observations... Krom the great difieulty, which: Messrs. Malus.and Bouvard had already experienced at a much shorter distance, we; were all inclined, to suppose, ‘that we had attained .a distance, at which the, human: voice,-even the loudest, ceases to be distinguishable in pipes. «| +; However, the extreme facility with which we heard each But this im- other.at .200, metres seemed to me to render so ‘great a di- Siew’ minution - altogether inexplicable. Besides, in the mathe- meats, matical theory of the motion of air we find nothing to indi+ and from the. eate, that sound should be diminished’ in ‘cylindrical ‘pipes. Byes ' It appears on: the contrary, that it ought to betransmittedto an indefinite distance jwith, the same intensity, deducting merely. the diminution, thatthe friction; of the air agatust the pipe might: perhaps, produce. 'To. decide the question, and know. positively whether sound were weakened in such an extraordinary. degree,: I resolved to remove or diminish all. the. causes of foreign and neighbouring noises, that might drown the sound I sought to hear. I went to the The experi- place of experiment, only with Mr.’ Martin and two intelli ee nae gent workmen, and chose for these experiments the stillest of night, hours. of the. night, those from one to four in the morning vt then discovered, that my conjectures were well Hastee when not only We not only heard the two sounds of the hammer and beil i sts so distinctly as to observe the intervals such as I have re- hammer, but ported them; but even the lowest voice was heard so as a lowest perfectly to distinguish the words, and to keep up a con- oe fis yersation on all the objects of the experiments. 1 wished to determine the point at which the voice ceases to be audible, . but could not accomplish it: words spoken as low as when we whisper a secret in another’s ear were heard and under stood ; so that not to be heard there was but one resource, that of not speaking at all. ' _ From this experiment there can be no doubt, that words may be transmitted so as te be distinctly heard at a more considerable distance. Between a question and answer the interval was not greater, thag was necessary for the trans- mission o ow 112 Grave and acute sounds have equal ve- Paya aving on the Bute. ° ; Echo of the. yoice returned repeatedly to the speaker, PRANSMISSION OF SOUND THROUGH LONG /TUBES: mission of sound. For Mr. Martin and me, at the citems of 951 m. [1040 yds.], this time was about 4°58.” We also ascertained anew, thategrave and’ acute sounds are transmitted with equal sjaltctioan which is agreeable to theory, and hes been several times observed. 'Tunes ou the flute, played at one extremity’ of the pipe,’ were transmitted to the other without any alteration in the intervals ‘of thé different. intonations, It appedred to me’ only, that ‘the very high notes were not heard so well as the low notes 4 and sometimes, when they were extremely high, Post them entirely; though I heard others that ‘were lower, ° ‘which, from the nature of the tune, 1 knew to’ ie weaker ee — former*, : Bim heard my own voive repeated by séveral-echoes; which sué-s ceeded each other’at exactly: edit “intervals: In’ ovr last experiment I ‘counted ‘tio less ‘than’six, about6-3” dis- tant from each other.” (The last returned after a little’ less than $3”; that is, nthe time requisite for the transmission of the sound to:thecother vend of the:pipe. “These pheno= {nena occurred equally at each ‘extremity of the pipe, whew | wei spoke into it. Of this P satisfied myself by requesting put, the 2 a at the other end single Detonations. . A pistol fired at ove end blewouta gandie at the ether. * Mr. Martin, through the pipe,’ to observe them, without » Communicating to him wy results: and his, kes res ported te me immediately in'the same way, were perfectly ‘similar. Theonumber of echoes and their intervals were the same, and the total of the time, was the same also; but the peraen who is spoken to never hears but one’sound. ©” Lastly, detonations capable of producing a considerable agitation in the air were transmitted to the other'end of the pipe with an intensity proportional to their strength. “Rea ports of a pistol fired at une end occasioned a considerable explosion at the other. "Phe air was ane out of the pipe * Since this paper was read, i have found, shiase the person who- wtiaed the flute, having very weak lungs, could with difficulty bring out the high. notes, and was frequently oblized t» skip them entirely. It was very natural therefore, that | should not hear them: but TF have thought pro- per to let my first account remain, that the reader may see I reported faithfully the smallest particulars; and that my veracity in this cireum- stance may confirm the other results { observed, with I also observed. that, in aealthe shied the pipe, ? & ‘OBSERVATIONS AND BXPERIMENTS, ON PUS. 113 with sufficient force to give the hand a smart blow, to drive ¢ light substances out of it tothe distance of half a yard, and to extinguish a candle, though it was 950 m..{1039 yds.] distant from the place where the pistol was fired. Yv. Observations and Expériments 6n Pus. By GEorcE ‘ PEARSON, M. D.F.R.S. c ye Concluded Ry he) Ae ak ee 3 \ Section VIL. Conclusions. ae statement of the properties of pus in the foregoing General inquiry I hope will be found to be true; and I submit to the conclusions. judgment of others whether or no the a inferences are legitimately established. 1. That this fivid essentially consists of three distinct sib. Pus consists of ©) stances, viz. 1. An animal oxide, which, among other pro= Bice eis eaet substances, perties, is distinguished by its being white, opaque, smooth, of the form of fine curdy particles in water; not dissoluble in less than 1000 cold waters ; not coagulable into one mass like ser ‘um. ‘of blood by caloric, aleobol, Ges only ‘rendered more curdy by water from 160°to 170°; but readily diffusible. —2. A limpid fluid resembling serum of blood in its im- pregnations, andi in its coagulability by calorie, oleage » &e.; in which the opaque oxide is diffusible but not dissoluble, _ and which is specifically lighter than that oxide,—3. Innu- merable spherical particles visible only by the microscope in this opaque oxide, and in small number in the limpid fluid; not coagulable by any temperature to which hitherto exposed, and, not destructible by many. things which combine or de- stroy. the opaque oxide;.and these globules. are specifically dba than panes” bs “My obligingly : attentive pupils, Mr- Burton, and Mr. STANSFELD, Onde-suirgeons ¢ of the Lock hospital, ‘collected’ for me ‘a sufficient quans tity’ Of gonorrheal matter to determine, that it consisted of 7 three ingiiedients here stated. a Vou. XXX.—Ocr. 1611. ; I ; Q. That 114 Visible curdy asses, Red or dark colour of pus. Irregular matses. Feitor. Adventitious contagious matters, Secretion of pus from the blood, Sources of the differences of pus. OBSERVATIONS AND. EXPERIMENTS. ON PUS. 2. That the visible curdy masses, as well as the fibrous or leafy parts, almost always contained in smaller or larger quantities in pus, may be considered as self-coagulated lymph, which. in its fluid state is secreted without having the state of aggregation produced in it like that of the essential opaque oxide of pus.—Sect. VII, 1, ere 3. That the reddish, the blackish, and the dark brown colour of pus depends upon the red part of the blood effused or secreted from the same vessels, or ;from contiguous ones ete: secrete pus. ! . That on some occasions the clotty and irregularly “iat masses found inthe pus may depend upon disorgani- zation or breach of the contiguous solid parts. 5. That whenever pus is fastid’to the smell, a portion of it is in the state of putrefactive fermentation, which may be removed by ablations with water. 6. That there are certain adventitious matters liable to be contained in pus not hitherto rendered palpable to the senses, but known by their effects in exciting contagious diseases; such as small-pox, sy philis, &c. These matters are ‘produced by a specific action in the secretory organs of pus, by such matters themselves either contained ia the. circulating b blood, or on the. secreting surface. 7+, That, the essential substances a which pus consists, as well. as some of the adventitious ones (Sect. VII, 1, 2, 3, 6), are separated froin, the blood by a peculiar organization be-. longing, or. attached to the blood-vessels: which « organs | of separation or , secretion are not, only excited to the action which produces pus in ‘deseased states, but they are evidently influenced by the states of other distant organs of. the animal ceconomy ; hence many varieties ny the properties § of Rs pu- fulent matter. 8. That the varieties of purulent matter relate’ ‘to diffe. rences of quantity—the propor tion of the essential sibstances (1)—and the adventitious: parts (2, 3,°4, 5, 6,). “The cream= like pus consisting of almost purely the opaque , oxide dnd himpid liquid (I, 1, .2,). The curdy. containing a large pros portion of:coagulated. lymph, or broken down solids, | The sergus abounding in. Tapp fluid. The. viscid, d. depending upon OBSERVATIONS AND EXPERIMENTS ON PUS. ~ 115 upon the coagulation, and perhaps, inspissation, by union of neutral salts with the opaque oxide. ~ g. That as the essential parts are secreted in a limpid state, selfohae but presently become opaque, owing to a'large proportion ware ook spontaneously coagulating, and thus becoming the opaque serum separa- oxide, mixed with the serous liquid, and fdnuaiehable spheri- aha On eal particles (Sect. VII, I, 1, 2, 3), it seems reasonable to infer, that these matters are the self-coagulated lymph of the blood and serum, separated by the secretory organs; which act of secretion determines the subsequent state of aggregation of pus, and the globules are at the same time formed analogously to their formation by other secretory organs. How far they are these of the blood altered by secretion may be determined hereafter. It is a collateral proof of this inference, that very thick pus affords from one sixth to one seventh of exsiccated brittle residue, which, as I have found, is nearly the same proportion afforded on the exsiccation of the buffy coat of inflamed blood; while very thin pus affords on exsiccation from one eighth to one eleventh of brittle residue, which is the proportion to be ex- pected from a mixture of serum of blood and self-coagulated lymph, as I have ascertained. '.10.. That the constant inpregnating saline and earthy Saline and ingredients of pus are dissolved in the serous fluid; and are seach all separable along with the serum, by ablutions with water, from the opaque oxide (1), except a portion of the phosphate of lime. These impregnations are the same as those of serum of blood, and of expectorated mucous matter, viz. muriate of soda; potash neutralized by animal matter ora destructible acid; phosphate of lime; ammonia neutralized probably by phosphoric acid; with a sulphate, and traces of some other matters meutioned in my former paper. The ‘proportion ‘of these impregnating sub-tances is as the pro-. portion of limpid or serous coagulable fluid, and of course inversely as the proportion of the opaque oxide of pus; but it varies in different cases in given proportions of this oxide, : and the. limpid fluid. In general, if not always, a given ' quantity of pus contains a smaller proportion of saline mate ters than. an equal g given quantity of expectorated mucous matter, but a given quantity of the limpid coagulated fluid. te contains. 116 | Caleuli in abscesses. Different se- cretions from the same ergans in diffe- rent states, _ Consistence of pus, Distinction of pus from other matters. Stones in the lungs, OBSERVATIONS AND EXPERIMENTS ON PUS. eontains a greater proportion of saline matters than an equal given quantity of serum of blood. Hence the thicker the pus the less irritation to the sore which secretesit, and com- movly the less the inflammatory or other action of the se- creting surface. In different cases, however, the proportion. of impregnating saline substances to one another is liable to, vary, especially that of phosphate of lime; hence, though rarely, calculi occur of this substance in the cavity of the abscess*. \ Hence too the exsiceated pus is liable to become soft and moist, from the proportion of neutralized potash being g oreater than usual; and eveu deliquescence sometimes, octurs of the exsiccated limpid fluid. 12. That the same organs, according: to their different states, secrete from the blood merely water impregnated with the saline substances of the: serum of blood; also this fluid containing various proportions of coagulable matter like that of serum of blood; and sérous fluid. with self-coa- gulable lymph, which affords curdy masses: likewise this serous fluid, together with this matter which coagulates of itself aftér secretion, highly impregnated with invisibly smalb - particles, in such astate of aggregation, as to constitute the thick opaque fluid called pus—which states of the secretory. organs are generally attended with inflammatory action, but _ frequently also without any symptoms of such action. 13. That beside'the consistence of pus depending upen . the proportion of serous limpid liquid,.and opaque matter, it also probably depends upon the mode and state of coagula- tion of the matter whiclvaffords this opaque part ; ail a seraklle to the different states of consistence of the coagulated blood itself, according to the different, conditions of the animal geconomy. » ‘According to the above inferencess: Itrust, a distinet ag definite notion of the substance-to be considered as pus is mo r ’ ; : » * On examining the ‘Jungs of a patient who died of pulmonary con- sumption, concretions: were found in a large vomica from the size of mus¢ tard seed to a pepper corn, whjch Dr. EN. BANchosT teserved for my inquiry. 1 found they consisted chiefly of phosphate of lime, with an urmusually small proportion of animal matter.’ In another patient of Dr, NEVINSON, matter was coughed up, consisting chiefly of phosphate of linre and animakmatter, nearlyone of the former to thrée.of the latter, eee exhibited OBSERVATIONS AND EXPERIMENTS ON PUs. 117 ‘exhibited; and Ido not comment on the different results 6f experiment and conclusions of other writers, because future observers only ean determine the truth. What is and what is not pus will now readily be acertained by a few easy ex periments; by the obvious properties; and by the considera- tion of the source of the matter in question: provided, how~ ever, that it be unmixed with certain other matters, by.which ‘disguise is produced, As already observed it is in pulmonic diseases that the ambiguity occurs; and physicians lay very considerable stress upon the ae of ex pectorated matter in their practice and reasoning; | shall therefore endeavour to Puriform mat- elucidate the subject by remit on the puriform matter ie et , expectorated in different casés. 1, An abscess occasioned by acute inflammation not only from an ab. of a pleurisy, and peripneumony, but of other diseases which aan have not the symptoms of any one which has received a de= mation; sigpation. Here there ought to be no duubt; forthe matter, which is coughed up shddenivs and abundantly on the bur sting of the abscess is evidently pus with little mucus. Such matter consists of the essential ingredients of pus, (Sect. VII, i,) with generally the adventitious substances, (Sect, VIT, 2, 3, 4,) viz. coagulated lymph, menbranous or fibrous parts, and a small proportion af the red part of blood. 2. Purulent expectoration from the rupture of abscesses; fiom the rupe or vomicse of suppurated tubercles. In’such.cases' there has ture of s been a chronical cough with viscid ‘sputum, commonly: iy ees ’ petsons of an Bivdticed age. After this long contiiued dis2 tubercles; ease, an abundant expectoration of quite a different kind from the foriner suddenly come’ ‘én; by which the: patient often dies very speedily; sometimes immediately, ieing seemingly choaked., This kind of matter evidently consists chiefly of the essential ingredients of pus (Sect. VIL, 15) with not only the adveititious substances, viz! clots of self-coagu~ lated lymph, and’ sometimes the red’ part of blood, but also masses, which are apparently the broken down solid parts, the cllular membrane, the vessels, and substance ofthe tubercles, ina disorganized state. The sufferer often says, such matter tastes sweet. The mucus’is here!in too small a proportion, and not intimately mixed, to occasion disguise. 3. In the bronchitis, or inflammatory affection of the air ; in iuflame : tubes 118 OBSERVATIONS AND EXPERIMENTS ON PUS. matory affee. tubes, the membrane remaining entire, attending various tion of the zir-tubes, Muco-purue Tent matter. diseases, e. g. the measles, a fever with acold, various con- tinued fevers, an expectoration of thin creamlike matter occurs, at first gradually, but at last in great quantities, con- tinuing for a week or more, Although mucus is usually coughed up with this puriform substance, the two things generally remain in distinctly large masses. With little skill the opaque or puriform fluid may be collected separately from the mucous matter, It will be found to consist almost purely of the three essential constituents of pus (Sect, VII, 1,) there being seldom any adventitious substances, 4, Muco-purulent, or commixed expectorated matter, This kind is perhaps of the most frequent occurrence. It is that which many physiciaus know not how to desiguate, some consider it to be pus, and others to be mucous matter, This contrariety of opinion arises from the want of definite notions of pus and mucus. Hence the parties are not able to perceive, that in this kind of sputum exist many of the pro- perties of pus, and.also of mucus. I have deseribed it in "any former paper on expectorated matter, Phil. Trans, 1809, P. II, p, 317*, under the denomination of opaque ropy matter, the third kind, I feel no degradation in finding it - necessary to confess, that a better acquaintance with. the properties of pus has taught me, that I was in an errour, in considering this kind of expectorated matter to differ from other sorts merely in the proportion, and not in the kinds, of coustituent parts. It now appears that the sputum in ques- +ion possesses such properties as might be predicted to exist, from the known properties of pus and mucus separately, in case these two substances should be intimately commixed. Accordingly, the opacity; the straw colour; the greater density than mucus; the great globularity under the micro- scope; the greater praportian of residue on evaporation to | dryness, than fron; mucus; the milky liquid on heating this matter; the milkiness on agitation in cold water ; are pro- perties of pus. But the great viscidity, yet not increased by veutral salts; theless opacity than pus; the less globularity than pus; the smaller porprotion of exsiccated residue than * Journal, vol. XXV, p- 219, | mata from ¢ OBSERVATIONS “AND EXPERIMENTS ON PUS, 119 from pus; the moisture, or greater moisture on the ex- posure of the brittle residue to air, than from that of pus; the more difficult diffusibility through cold water, and less degree of milkiness than from. pus: the great proportion of leafy or fibrous, unasses on agitation in a very large quantity of cold water; the speedy putrescency ; .are properties of mucus. The mode of coagulation by caloric at 160° and upwards 1s such as might be expected from the commixture, viz: in large masses of curd in a milky liquid, instead of into one uniform mass like pus, or into,small curdy masses in a very large proportion ofa whey coloured liquid, like mucous sputum. Thick pus affords on evaporation to brittleness, } or 4 residue; and transparent sputum of the consistence of jelly, gives about 5!, or zy of such residue: but this opaque ‘matter under inquiry, affords yy or 7's of brittle residue, ac- cording to the proportion of the two substances. 1 could not separate the supposed pus and mucus from one another, to exhibit them distinctly: by water, or by any other means, on account, asI conceive, of the intimate diffusion through one another, and their mutualcohesion, But on evaporating the milky water, produced by agitating this sputum in it, or by letting it stand to collect the sediment, little else besides a mere Congeries of globules seen under the microscope was thus obtained. For the same reason, on standing, a serous liquid like that of pus (Sect. VII, 1) does not separate, or only partially, from the opaque part, so as to render it pos- sible by ablution, to collect this: coagulable liquid like that of pus: and the greater proportion of water, belonging to the mucus, occasions the coagulation by caloric, to afford only a milky liquid, instead of a uniform mass of curd, __ This kind of sputum, consistently with the phenomena, From secretion must be produced by secretion from the bronchial membrane bse isis in its entire state, and not by ulceration or abscess. For it is secreted in many cases, at the rate of a pint or more in each 24 hours, for weeks and months successively, and for 20 or more successive winters. Also many persons recover their good health after this secretion, and itis the usual termination favourably of pneumonia, bronchitis, &c. It is produced by any disease of great irritation of the lungs; as I have found from 720 OBSERVATIONS AND EXPERIMENTS ON PUS. Broken wind. fiom ossification of the bronchial or pulmonary arteries: from’ calevli: from broken wind, or rupture of air cells, &c.* ) Secreted in Ht is secreted also in consequence of irritation of the bron- bay trea. chial membrane by tubercles, vomice, water in the cavities of Nuse. the chest, &c. The same kind of matteris secreted from the nose on the decline of a common severe coryza in many cases, Someti:mes in. It appears then, that this kind of matter is a symptom of the dicutes death, most fatal, as well as harmless diseases—it is a symptom in sometimes re- : . é i covery, one-case of the progress of disease to death, and in another of the termiuation in health, by being seemingly a critical discharge. Perhaps, if these facts had been observed and considered, numerous mistakes in prognostics would have. been avoided, and better practice have been employ ed; be- cause the nature of diseasés would have been tightly under- stood. From this representation itis plain, that a just opinion cannot be given merely from the examination of the sputum, without considering the disease by ibs te itis produced, or of which it is a symptom. — The proportion must also be considered of the | pus and mucus In sputum: it may be estimated, by attending to the properties of each, as above stated. i Secretion of Such a compound as the present searcely is produced in alia any other part, but in the bronchial,-and tmucous membrane "of the nose, because of the abundant secretidn of mucus from these membranes. And whew itis conceived, that both’ ° pus and tucus are secreted ina limpid' state, from the same ” or at Teast Contiguous organs, where they first ‘intimately commix, and then become inspissated; it will appear reason- able, thiit they cannot be readily, or at all completely sepa- rated again from one another.’ Phere is indded; in’ these” cuses, no'necessity for the admission of the secretion ‘of the © limpid fluid of pus of abscesses (Sect. VIE, 1) ; for it ape” pears to me not unjust to consider mucus to be ‘nothing more than thé serum of blood, altered in its composition ” and proportion of water, so as to produce’a viscid texture, d The secretory organs of the mucous membrane,’ By: virtue of their iia aie yi Se. in i ‘blobd, “in health, of y tn apicta + rib fy iO NG) ayvov At it 2 ‘ofa Hb Vis * | helieve this state of ae ee to have been first pstesy in broken winded horses, by Mr,: Colman. the . - DESCRIPTION OF A TACHOMETER. et. the mucus as above said) with some globules, and also a~ small proportion of the self-coagulable lymph; which ap- pears, on’ agitating mucus in a large proportion of cold water, in the form of leafy and fibrous masses*. The same secretory organs, it is easily conceivable, may, in a diseased state, be excited to separate also selt-coagulable matter from the blood, with more globules, im such a state as to become’ pus. “Hence, such commixture of the two sub- _ stances must correspond to the a ates" viscid, SNA ciliate sputum, of which [ am writing If I'thousht farther reasoning proper, it wonld be mani- fest, that all the phenomena, both in health and disease, be- longing: to the various kinds of sputum, consist with. os theory abov e delivered, ‘ VIL Bice ofa Tacho ameter, or an Instrument to ascertain the Velocities. of Machinery: by Mr. Bryan Donan, of Fort Place, Rermondses yte tx: the rates of machinery it is asa ata of great Advantageous importance, to be provided with an easy and ready method toeseernthe for, discovering at all times, whether the motion of the machinery. machine is quicker or. slower than what is known to be best. adapted for the object in view.. This advantage, it is hoped, may, be, derived from the tachometer ;, for it is an instru- ment which requires only to be adjusted once for all: to any particular. machine, and then it will al@ays be ready with out the belpof calculation or of a time-piece, to indicate in- stantly upon, inspection the slightest excess or defect in the actual velocity. | .A front view of the tachometer is represented in fig. 1, An instrument’ | ahd a side view in fig, 2,,of Pl. UI. X.Y Z, fig. 1, 1s the for this pur- pose described. vertical, section of a. wooden cup, made of box, which is. . #Serum of blood appears always to contain self coagulable lyniph, ‘whieh is deposited! on standing 3 and! this appearance led Gaber, Pringle; anid Cullen, into the erroneous opinion of this deposit being pus itself, tt Lrans. of the Soc. of Arts, vole XMVIII, p. 185, The gold medal, was voted to Mr, Donkin for this inyention, . Ui drawn Method of usipg If. DESCRIPTION OF A TACHOMETER. drawn in elevation at X, fig. 2. Fhe whiter parts of the section, in fig. 1, represent what is solid, and the dark parts what is hollow. This cup is filled with mercury up to the level LL, fig. 1. Into the mercury is immersed the lower part of the uptight glass tube A B, which is filled with co-_ loured spirits of wine, and open at both ends, so that some ‘of the mercury in the cup enters at the lower orifice, and when every thing is at rest, supports a Jong column of spi- rits, as represented in the figure. The bottom of the cup is fastened by a screw to a short vertical spindle D, so that when the spindle is whirled round, the cup, (the figure of which is a solid of revolution) revolves at the same time round its axis, which coincides with that of the spindle. = In consequence of this rotation, the mercury in the cup, acquires a centrifugal force, by which its particles are thrown outwards, and that with the greater intensity, ac- cording as they are more.distant from the axis, and accord- ing as the angular: velocity is greater. Hence, on account of its fluidity, the mercury rises higher and higher as it re- cédes from the axis, and consequently sinks in the middle of the cup; this elevation| at the sidcs,. and consequent depression in the middle, increasing always with the velo~ city of rotation. Now the mercury in the tube, though ‘it does not revolve with the cup, cannot continue higher than the’ mercury immediately surrounding ‘it, nor indeed so high, on account of the superincumbent column of spirits. | Thus the mercury in the tube-will sink, and consequently ~ the spirits also; but as that part of the tube which is within the cup is much wider ‘than the part above it, the depression of the spirits will be much greater than that of the mereury, being in the same proportion in which the square of the larger diameter exceeds the. square of shis bSes smaller. Let us now suppose, that, by means of a cord passing round a sinall pulley F, and the wheel G, or H, or in any other convemenut way, the spindle D 1s connected with the machine, the velocity of which is to be ascertained. In foyming this connection, we must be careful to arrange - matters so, that, when the machine is moving at its quickest rate, the angular velocity of the cup shall not be so great ae DESCRIPTION OF A TACHOMETER, . 123 as to depress the spirits below C. into the wider part ofthe tube. We are also, as in the figure, to have a scale of inches and tenths applied to A C, the upper and narrower | part of the tube, the numeration being carried downward from zero, which is to be placed at the point to which the column of spirits rises when the cup is at rest. Sede’ Then the instrument will be adjusted, if we mark on the scale the point to which the column of spirits is depressed, when the machine is moving with the. velocity required. But, as in many cases, and particularly in steam-engines, there is a continued oscillation of velocity, in these cases we have to note the two points between which the columa oscillates during the most advantageous movement of the machine. Here it is proper to observe, that the’ heicht of the co- Correction for lumn of spirits will vary with the temperature, when other “™Petature. circumstances are the same. On this account the scale ought to be movable; so that, by slipping it upwards or downwards, the zero may be placed at the point to which the column reaches when the cup is at rest; and thus the instrument may be adjusted to the particular temperature with the utmost facility, and with sufficient precision. The | essential parts of the tachometer have now been mentioned, as well as. the method of adjustment; but certain ¢circum- stances remain to be stated. , The form of the cup is adapted to render a smaller quan- tity of mefcury sufficient, than what must have been em- ployed either with a cylindrical’ or hemispherical. vessel, In every case two precautions are necessary to be observed : Precautions. First, That, when the cup is revolving with its greatest ve- locity, the mercury in the middle shall not sink so low as to allow any of the-spirits in the tube to escape from the lower orifice; and that the mercury, when most distant from the axis, shall not be thrown out of the cup. Secondly, That, when the cup is at rest, the mercury shall rise so high above the lower end of the tube, that it may auippoak a column of spirits of the proper length, Now in order that the quantity of mercury, consistent with these conditions, may be reduced to its minimum, it is necessary—first, that if MM, fig. 1, is the level of the mer- RSPR i cury 124 Form of the @up. DESCRIPTION (OF A TACHOMETER. eury at the axis when the cup is revolving with the greatest velocity, the upper part Mi M X Y of the cup should be of such a form, as to have the’ sides covered only with’a thin film of the ‘fluid ; and secondly, that for the purpose of “raising the ‘small quantity of metcury to the level LL, | wane may support a proper height of spirits when the cup is at fest; the eavily of the cup should bé in a preat mea- sure occupied by the block KK, having a cylindrical per- foration in‘the’ middle of it for the immersion of the tube, and leaving sufiicient room within and around it for the mercury td move freely both along the sides of the tabe and of the vessel. ya The block eK ‘js preserved in its proper position in the cup or vessel X Y Z, by means of three narrow projecting slips or ribs. placed at equal distances round it, and is kept from rising or floating upon ‘the mercury by two or three small iron or steel pins ifiserted into the underside of the cover, near the aperture through which the tube passes, Tt would be extremely aimeuti, however, nor is it by any ‘ means important, to give to the cup the exact form, which would reduce the quantity of mercury to its minimum ; but we shall have a sufficient approximation, which may be executed with great precision, if the part of the cup above M M is made a parabolic conoid, the vertex of the genes rating parabola being at that point of the axis to which the mercury sinks at its lowest depression, and the dimensions. of the dueseh being determined in the following mariner : : Let V G, fig. 3, represent the axis ‘of the éup, and Vv ‘the . “point, to titel the mercury sinks at its lowest depression ; at any pont Gabove V, draw G Ef perpendicular to V G; let » be the number of révolutions, which the cup is to’ per= form ip 1” at its quickest motion; let # bé the’ number of inches, which a body would describe uniformly in’ 1”, with the veloc ity acquired 1 inv aS sa rest, through a Heteie = te GV and: rales Hue? pinte ~. Phen the ede to be determined i is that | which has v pie its vertex, Vv ken for its axis, and G H for’ its ordinate at G. The cup has a lid to prevent the mnereury fiom being thrown out of it, an erent which would take'plute with a very moderate velocity of DESCRIPTION OF A TACHOMETER, 195 of rotation, unless the sides were raised to an inronvenient height; but the lid, by obstructing the elevation at the sides of the cup, will diminish the depression in the middle, and consequently the depression of spirits in the tube: on. this account a cavity is formed in the block innmediately above the level L’ L, where the mereury stands ewhen the cup is at rest; and thus a receptacle is given to ‘the fluid which would otherwise disturb the centrifugal force, and impair the sensibility of the instrument. ¥ It will be observed, that’ the lower orifice of the: sigbe js, Curve at the bottom of the turned upwards, . By this means, after the tube, has beén-¢ybe, filled with spirits by suction, and its upper. orifice stopped. with the finger, it may easily. be conveyed to the cup and immersed in the quicksilver, without any danger. of ithe spirits: escaping,. a circumstance which otherwise it: would be be extremely. difficult to prevent, since no part of the tube. can be made capillary, consistently with that free passage to the fluids, which is us necessary to the Seneraioe of the instrument. ~~~: cee : We have next to ated to the aeeioa. of putting the Method of set- tachometer in motion, whenever we wish to examine the ve- alia locity. of the machine. The pulley F, which is continually motion, whirling during the motion ‘of the machine, has no connec= tion whatever Nae the cup, so long as the lever Q Ris left toitself. But when this: lever is: died the hollow cone T, which is attached to the pulley and whirls along with it, is also raised, and embracing a solid cone on’the spindle of the cup, communicates the rotation by friction. When our ob- servation is made, we have only toallow the lever to drop by. its'own weight, and the two cones will be: disengaged, and the cup remain at rest. The lever Q Ri 1s connected by a ic) tod to ‘aroha lever S, having at the extremity S a valve, which, when the lever Q R is raised, and the tachometer is in motion, is lifted up from the top of the tube, so as. to admit the.exter- _ nal air upon the depression. of the spirits;.on ‘the. other hand, when the lever Q R falls, and the cup is at rest, the valve at S closes the tube, and Prevshtf the spits from being wasted by evaporation, Pd | tis lastly to he remarked, that both the: pakilies hk Increase of the ‘the 126 ) MODE OF CONVEYING INTELLIGENCE. sensibilityand the range of the instrament may be infinitely increased ; ; range of the instrument, Applicable to delicate expe riments, Mode of con- veying intelli- gence by a re- connoitring © party. for, on the one hand, by enlarging the ‘proportion between the diameters of the wide and narrow parts of the tube, we enlarge in a much higher proportion the exteat of scale, corresponding to any given variation of velocity : and on the other hand, by deepening the cup.so as to admit when it is at rest a greater height of mercury above the lower. end of the tube, we lengthen the column of spirits which the .. Mercury can support, and consequentiy enlarge the velo-. city, which, with any given sensibility of the instrnment, is ‘requisite to depress the spirits to the bottom of the scale. Hence the tachometer is capable of being employed in very delicate philosophical experiments, more especially asa scale might be applied to it, indicating equal increments of ve- locity. But in the present account it is merely intended to state how it may be adapted to detect in machinery every deviation from the most advantageous movement, VII. A Mode of conveying Intelligence from a reconnoitring Party. Ina Letter from a Correspondent, To W. NICHOLSON, Esq: SIR, | I Herewith send you a model, which I denominate a. Hip- . pograph, and which appears to me likely to be of use in the . march of troops, &c. It may consist of any number of men and ‘taal but I. conceive an officer and six men quite sufficient. The use it - seems most adapted to is, when a mountain or high g cround— is in front, und it is wished by the commanding officer to know whut may be on the other side, by dispatching such a number of men intelligence can be at once conveyed by changing the front of one ur more men to express numbers,. or perinanent signals, as agreed on, as the boards of a tele- graph; and by the officer placing himself'on either flank, centre, or rear, the numbers would be'quadrupled.”” T know by \ MACHINE FOR SEPARATING IRON FILINGS. 197 by experience it may be distinguished at a great distance. Should you think this worthy bf notice, it will be a satis faction to, . Sir, your shietlieink belive August, 1811.0 H. 1. B. “The model consists of little tin casts of six horse soldiers and one Officer, see Pl. III, fig. 4. These are placed on a, slip’ of:wood, and each is movable on a aed so that it may be eee into any position. ‘ tosis does, iy VL. a abibn of a Machine for separating Iron Filings from their Mixture with other Metals: by Mr. J. D. Ross, | Princes Street, Soho*. SIR, a Hope you will be fens to lay before the gentlemen Machine for. of the Society of Arts &c. the model of a machine, which I ey iron have invented to separate iron-filings, turnings, &c., from Rive te those of brass or finer metals, in place of the slow and tedi- ous; process hitherto. employed, which is by a common spueuat heldin the hand. By my invention, many magnets may now be employed at once, combined and ae et toa machine on a large scale. The magnetic hammers are so contrived as to take up the iron-filings from the mixture of them with other filings, or metallic particles, placed in. the trays or,end boxes, and drop them into the receiving box | in the centre, which is effected by the alternate motion of a winch-handle, working the two magnetic hammers placed at two angles. of a quadrant or anchor. In proportion to the: power of the magnets, and to the force of the blow given by the hammers, a great quantity of iron is separated from the brass, by the iinettiete motion, and dropped into the recéivér plaiced in the centre of the machine. | 1 have shown’ the model to persons engaged in various “€ Trans, of ey So SF Arts, &¢., vol. XXVIII, p. 206. Five gui-. neas were voted to Mr. Ross for this invention. metallic 128 MACHINE FOR SEPARATING IRON FILINGS, metallic works*, who give me great encouragement, by their signatures and sanction, and I hope vit will mest with the Society’s approbation. it Tee ee een Iam, Sit, ae : Your most obedient and hombleservant, J. ph, ROSS. fi Reference: to. Me: Ross’s Machine for” (git Bs Filings from those of Brass, or other Metals, Figs.4 and 2, PLY yo" meat > ateiees Seno Seen Description of. .A is an axis Sian aud Ba uagdke pres ‘the "end: ‘of it: the machine, i 2 Its mode of eperation. C is a piece of brass in form ofan anchor, at each end of which a hoxse-shoe magnet, is fixed, in the manner shown at fig, 1, where cas the arch of the, anchor, aod da piece, > of brass having a hole through it to receive the legs ee okthe magnet, which is fixed to the arch by a screw. f, tapped into the arch, The anchor is mounted upon the pivotsief the © axis A, in a frame. E, whieh encloses it; on the outside. of the frame are two blocks of weod, FF, in each of which“a hollow or. tray is “formed to receive the filings! which‘ ate “9 t0 Be separated from the iron they contain in these Wullows! The magnets fixed atthe’ ends of the ‘anchor: gHRe Upon the filings, and select, by ‘the indgnetié’ ‘attraction, all the ifn ‘among them; ‘the’ anchor i is then turned « over by the “handle B, land the ¢ opposite ‘magnet strike inthe other hallow i At this tine the othei't Magnet js jast over the Axis, Sand? by the jerk oF its: opposite striking the block’ F, the iron-filings are shaken’ off, And: fatti PERSE on the® -ottom? Phe frame; or ‘rectiver. ” "TAs: maniier ‘the? meta be” B;: beiitg" pe batkwardsaad forwards, strikes the? eri eReES" alternat ély’ i the tid blodks'F 3 and at the ‘same ainie that’ ‘oné! siete ; the dpposite' is cleared? from the ror 4 Ft his picked ap by the shock. ‘Gis a’ seréen of thin’ cage th pa thé filiigs ~ beitig: Scattered.’ 10 “YS URUD eae womnd 9d? yd ee : 1Gitd a8) msila edi yd .easid sdf niott * eee different ‘persons certified sthat Liieii consider Mrz Ross’s iis ~ wention ofia machine for separating iroe- filings, turnings, &c., from tose of brass_ or finer metals, as likely to pore ape useful eeu branches of workers in metal, le “¢ Seaiieyp Sg 4 wis : % + se - Ye a) 3 Test ICE PROM ,1iv, GS RSZICT GIAW 1x: ee Pees juail’ ¢ . SASH WINDOWS ON. A NEW CONSTRUCTION. 129 | 1x. A new Method’ of constructing Sash Windows, so as to be cleaned or repaired without the necessity of any Person going on the'ouwtside of the House: by G. MarsHxLt, Nos 15, Cecil Court, St. Martin’s Lune*. ; aie Iw consequefice of the numerous accidents, which occur Accidents . from cleaning avd painting the outside of windows, I beg om cleaning windows fre- leave to submit to the inspection of the Society a model of quent. a sash-window, which, if it meets their approbation, and be- comes generally adopted, will, I think, save the life of many a fellow-creature; because the present mode of clean- _itig or painting the outside of windows is generally done by persons leaning out of the window, or getting upon a plank, or some other convenience made for the purpose, and pro- jecting. on the outside of the house; hence, from careless ness and inattention, many fatal accidents have occurred, and the services of many persons lost to their families and the public. One instance of this kind happened about three weeks ago to a man, who was standing on a board cleaning the outside of a window, when, the board giving way, as frequently happens, the man was precipitated, and impaled upon the spikes of the i iron pales, which enclosed the area below, whence he was conveyed to the hospital with no “hopes ‘of recovery. This unhappy man, I was in= formed, had a large family depending” upon him for sub- sistence. I was so shocked with the circumstance, that I was not easy til I had ‘made the model, which ‘I. thought would be the meéans of preventing similar accidents. This model, I beg leave to lay before the Society, and if it should Contrivance to i be so fortunate as to meet with their encouragement, a wily Prete’ oes Teceive any , “donation from ‘them with thankfulness, and have no doyot that it will be found to possess many ad« vantages. Ta appearance it it resembles a common sash, and the upper ot lower sheet.’ vmay “be moved up and down in a * Trans. of the Soc. of Afis, &cl, -voly ‘XXVIII, :p,’ ar Fifteeh eines were voted to Mr Muitshal]. 1) Vou. XXM.—Ocr. 1811. | -— siisitay 130 Another ad- vantage. The expense trifling, either in new orold sashes. Explanation of the plate, 2B. i Gee? Ah Lid SASH WINDOWS ON A NEW CONSTRUCTION. similar manner; beside which, by pushing two small springs back m the upper sheet, and at the same time pulling the ~ sash inwards, you may turu the outside of the’ sash towards you, into the room, so that it may be éasily painted, glazed, gr cleaned by a person standing within_the room, without the necessity of removing the slips or beadings, by domg which, in the common mode, the glass is frequently broken and the beads lost, left loose, or mismatched, and a considerable expense incurred. By turning the lower sash of my invention in a horizontal or inclining direction, you can look into the street without being wet ia rainy weather, or the rain driving into the room and damaging the furni- ture. Old windows may be altered to act upon this princi- ple, at an expense of twelve shillings per window; and new sashes and frames may be thus made for only six shillings more than the common price. j I remain, Sir, Your obedient humble Servant, GEORGE MARSHALL: Reference to the Delineation of Mr. Marshall's Window- Sash, fig. 3, Pl. IV. A A represents the window-frame; BB the lower, and CC the upper sash. The frame A A is fitted with grooves, weights, and pullies, in the usual manner; the fillets on the sash, which enter the grooves, are not made in the same piece with the sash-frame, but fastened thereto by pivots ‘avout the middle of the sash ; upon these pivots the sash can be turned as at C Cc, so as to get at the outside without disturbing the fillets or grooves; when’ the sash is placed vertically, as at B B, two spring-catches at a a shoot into and take hold of the sliding fillets, so that In this state the sash slides up or down in’ the usual manner } but it can be immediately released, and turned inside out, by pushing back’ the springs, and at the same time pulling the sash in- ‘wards; this tutus the outside towards the voi so that the sash ‘may easily be painted, glazed, or cleaned: on the oute ‘side by a person within the room, without removing the beads, which confine-the sash to slide up and down verti- cally; in the common way these beads are frequently breken “ ee ; bee me ’ * or ‘ OBSERVATIONS ON SHOOTING STARS. 133 ér misplaced, and cause considerable trouble by being always loose. By inclining the sash ou its pivots, the highest point being within the. room, the window may be left open in the most severe rain without danger of any entering the room, and a person may look out into the street without being wet. ———— ae X. Observations on the peculiar Appearances of those Meteors commonly called Shooting Stars. - In a Letter from ‘tuo- mas Forster, Esq. To W. NICHOLSON, Esq. SIR, Once moré I trouble you with some meteorological ob- Pceuliarity in servations, which, if you think worthy, I shall be obliged to ores wi you to insert in your next. In a former numiber of your mosphere. Journal [ noticed an apparent peculiarity in the €lectric atate of the atmosphere, during which the action of Mr. De Luc’s aérial electroscope was very irregular, The principal circumstances, which characterised such a state of the at- mospherical electricity, were the continual appearance of the cérrus cloud, which, like Proteus, was for ever changing _ its shape, and presenting itself to the eye under new figures; the prevalence of strong easterly and variable winds; and dry air. Among other circumstances I remarked the ap= _ pearance of numerous small meteors, or falling stars as they are commonly called, auring the night. . The same kind of weather has returned again this autumn, Similar appear- marked by similar circumstances, and the small meteors have ae ane re- again beennumerous. On thislast circumstance [dwell par- ; ticularly; for I have observed, that these meteors vary very Shooting stars considerably in appearance according to the kind of weather hve different which prevails, Those which I have alludéd to, and which in alaaliag are usually seen during the prevalence of clear dry weather and easterly winds, are small, they s:oot along very ra- pidly, and Jeave little or no train behind them; they have \ so much the colour and general appearance of the stars, that they have hence received their vulgar. appellation. . Si- K2 ; milar ‘y i b 132 Some of a pe- culiar appear- ance noticed. These have been seen only in the clear in- tervals of showery wea- ther, followed by high winds, .Alluded to by Virgil. A stationary meieor, ' OBSERVATIONS ON SHOOTING STARS. milar to these are those which are common in clear frosty winter nights. Larger ones than these generally attend warm summer evenings, particularly. when cirro-cumulus and thunder clouds abound’*, with easterly winds. On the 10th of last month, a showery day with northerly wind was followed by a very clear night abounding with small. me- teors, but they were of a very peculiar and unusual kind, being of a blueish white colour, hke the burning of phos~ phorus, and they left long trains behind them, of the same colour, which lasted for two or three seconds after their ex- tinction. I suppose in the space of an hour I.saw above thirty of them, but.they were all ofthis kind,’ and left the long white tails, which remained for some seconds in the tract in which the stars had gone. | These kind of meteors are strikingly different from the com= mon, kind noticed above ; I haye sometimes seen them. be= fore, but it, has always been in the clear intervals of showery weather, previous to the occurrence of high wind: it was. probably. this sort of meteor to. which Virgit alluded as a prognostic of windy. weather. . Scepe etiam, stellas, vento impendente, videbis Precipites. ceelo labi, noctisque per. umbram Flammarum Jongos a tergo albescere tractus. Georg. lib. i, v. 866.: On the evening of the 25th of last June I saw a meteor, which. was a perfectly stationary - accension, and lasted scarcely a second ; it was Hilt sag by. many days of damp rainy weather. I wish that Meteorologists would note down the peculia- rities observable in meteors in their monthly journals. I shall conclude by observing, that, if these considerations | should appear trifling and Nivctons to any of your readers, it must be remembered, that it is only by accurate and re- peated observation of a multitude of phenomena, that the science of meteorology can be brought to any ween of per- fection. I remain, Sir, yours &c._ Clapton, Sept. the 1sth, | | THOMAS FORSTER. | 1811. wai do not allude to those: very large meteors, which sdcl veil ap* : Such for example, as that seen in August, 1783, : XI. ON THE COMPOSITION OF ZEOLITE. 133 XI. : Qn the Compusition of Zeolite. ey James SmiTitson, Esq. LF. R..S*. ‘al Wiens. bodies being, in ict, native chemical pre- § Species of mi- parations, perfectly analogous to those of the laboratory of alas seal art, it is only by chemical means, that their species ‘can be only by che ascertained with any degree of certainty, especially \ under Mistry. all the variations of mec a eae state and intimate admix- - ture with each. other, to which they are subject. And accordingly, we see those methods, which profess to supersede the necessity of chemistry in mineralogy, and to decide upon the species of it by-other means than hers, yet bring an unavoidable tribute of homage to her superior powers, by turning to her for a solution of the difficulties, A which continually arise to them ; and to obtain firm grounds to relinquish or adopt the conclusions, to which the princi- ples they emplov lead them. Zeolite and natrolite have been universally ad mitted to be Zeolite and na- species distinct from each other, from Mr. Klaproth having poset He ise discovered a considerable quantity of soda and no lime, in tinct species. the composition of the latter, while Mr. Vauquelin had not found any portion of either of the fixed alkalis, but a consi- derable one of lime, in his analysis of zeolitet. / The natrolite has been lately met with under a regular crystalline form, and this form appears to be perfectly si- milar to that of zeolite ; but. Mr. Haiiy has not judged him- self warranted by this circumstance, to consider these two bodies as of the same Species, because zeolite, he says, *¢ does not contain an atom of soda.” Thad u many years\ago found soda in what I pet ha to Soda found in be zeolites, which I had collected j in the island of Staffa, nl ae po having formed Glauber’s salt by treating them. with sulphu~ ; ric acid; and I have since repeatedly ascertained the pre- sence of the same principle in similar stones from various ® Phif, Trans. for 1811, p. 171, + Journal des Mines, No. XLIV. { Journal des Mines, No. CL, Juin 1809, p. 458. other 134 but their idens © tity with Haiiy’s meso type not ascer- tained. A specimen sent by Mr. Haiy, ON YHE COMPOSITION OF ZEOLITE. other places; and Dr. Hutton and Dr. Kennedy had like~ wise detected soda’ in bodies, to which they gave the name of zeolite. . ’ There was, however, no certai nty, that the subjects of any of these experiments were of the same nature as what Mr. Vauquelin had examined, were of that species which Mr. Haity calls mesotype, * Mr. Haiy was so obliging as to send me lately some spe- cimens of minera's. There happened to be among them a cluster of zeolite in’ rectangular tetrahedral prisms, termi- “nated by obtuse tetrahedral pyramids, the faces of which coincided with those of the prism. These crystals were of. a considerable size, and perfectly homogeneous, and labelled This zeolite, or mespty pe, analysed, by himself ‘* Mesotype pyramidée du depart. du Puy de Dime.” I availed myself of this very favoyrable opportu- nity, to ascertain whether the mesotype of Mr. Haiy and natrolite did or did not differ in their composition, and the results of the experiments have been entirely unfavourable to their separation, as the following account of them wiil show. 10 grains of this zeolite being kept red hot for five mi- nuveslost 0°75 of a grain, and became opaque and friable. In a second experiment, 10 grains, being exposed for 10 mi- nutes toa stronger fire, lost 0°95 of a grain, and consolidated into a hard transparent state. 10 grass of this zeolite, which had not been heated, were reduced to a fine powder, and diluted muriatic acid poured upon it. On standing some hours, without any application of heat, the zeolite entirely dissolved, and some hours after, the solution became a jelly: this jelly was crane to a dry state, and then made red hot. Water was repeatedly poured on this ignited matter, till nothing inore could be extracted from it. This solution was gently evaporated to a dry state, and this residuum made alight! red hot, It then weighed 3°15 grains. It was mu- riate of soda. | The solution of this muriate of soda, being tried with so-- lutions of carbonate of ammonia and oxalic acid, did not afford the least precipitate, which would have happened | had ON THE COMPOSITION OF ZEOLITE. 2035 shad'the zeolite contained any lime, as the muriate of lime* ‘would not have been decomposed by thevignition. : The remaining matter, from which this muriate of soda had been eabaleod: was repeatedly digested with marine acid, till-all that was soluble was dinsslieed. W hat remained »was silica, and, after being made.-red hot, weighed 4°9 grains. Thg-muriatic solution, which had been decanted off from the silica, was exhaled to a dry state, and the matter left made red hot... It was alumina. To discover whether any magnesia was contained among this alumina, it was dissolved in sulphuric acid, the solution evaporated to a dry state, and ignited. Water did extract some saline matter from this ignited alumina, but it had not at all the appearance of sulphate of magnesia, aud proved to be some sulphate of alumina, which had escaped decomposition, for on an addition of sulphate of ammenia to it, it produced crystals of compound sulphate of alumi- na and ammonia, in regular octahedrons. This alum and alumina were again unixed and digested in ammonia, and the whole dried and made red hot.. The alumina left weighed 3°1 grains. Being suspected to contain still some sulphuric acid, this alumina was dissolved in nitric acid, and an excess of ace- tate of barytes added, A precipitate of sulphate of baryies fell, which after being edulcorated and made red hot, _ weighed 1°2 grains. 1f we admit } of sulphate of barytes to be sulphuric acid, the quantity of the alumina will be - = 3°1—0°4 = 2°7 grains. From the experiments of Dr. Marcet}, it appears, that 3°15 grains of muriate of soda afford 1°7 grain of soda. Hence, according to the foregoing experiments, the 10.41; component grains of zeolite analysed consisted of . i partse 4 PE as, sets dae uatlacnsime tetas 4°90 z ; : Alumina ceeeres reeresescoes cay 2°70 Soda Coe emeeersereroecregcere 3:70 Ice -eecveccccecseereccccceces 0°95 10°25 * These names are retained for the present, as being familiar, thoug h since Mr. Davy’s important discovery of the nature of what was called _ oXimuriaticacid, the substances, to which they are applied, are known not to be salts, but metallic compounds analogous to oxides, * Phil, Trans. 1807: or Jqurnal, vol, XX, p. 30, o 1386 Reasons for re- taining she name of zeo- jite. Names given by discoverers should not be - altered. Existence of hosphori¢ acid stispected in it, but none found, Js quartz an acid? ON THE COMPOSITION OF ZEOLITE. ~~ As these experiments had been unflertaken|more: for the purpose of ascerta’ning the nature of the component ‘parts of this zeolite than their proportions, the ebject of them was considered as accomplished, althougli perfect accuracy 10 the latter respect bad not-been attained, and which, indeed, the analysis we possess of natrolite by the illustrious chemist of Berlin renders unnecessary. . mage’ | I am induced to prefersthe name of zeolite for this. spe- cies of stone, to any other name, from an unwillingness to ebliterate entirely from the nomenclature of mineralogy, while arbitrary names are retained in it, all trace of one of the discoveries of the greatest miueralogist who has: yet ap- peared; and which, at the time it was made, was considered exyand was, a very considerable one, being the first addition of an earthy species, made by scientific means, to those es- tablished immemorially by miners and lapidaries, and hence having, with tungsten and ‘nickel, led the way to the great and brilliant extension, ‘which mineralogy has since re+ ceived. And, of the several substances, which, from the state of science in his time, certain common qualities in- duced Baron Cronstedt to associate together uader the name of zeolite ; it is this which has been mest immediately un- derstood as such, and the qualities of which have been as- sumed as the characteristic ones of the species. Indeed, I think, that the name imposed on a substance by the discoverer of it ought to be held in some degree sa- cred, and not altered without the most urgent necessity for doing it. It is but a feeble and just retribution of respect for the service, which he has rendered to science. Professor Struve, of Lausanne, whose skill i in mineralogy. is well known, having mentioned to me, in one ‘of his letters, that, from some experiments of his own, he was led to suse pect the existence of phosphoric acid in several stones, and particularly i in ve zeblite: of Auvergne, I have directed my inquiries to this: ‘point, t but have not found the phosphorie, or any other acknowledged mineral ‘acid, i iD this zeolite. Many persons, from experiencing much difficulty | in comprehending the combination together of the earths, have been led to suppose the existence of undiscovered girs in stony crystals. If quartz ‘be itself considered as an acid, ‘ MARIVE ALLOY .OF GOLD AND PALLADIUM. ‘137. acid, to which order of bodies its qualities much, more nearly assumilate it, than. to the earths, their composition becomes — aeadily intelligible. .They will then be neutral salts, sili- cates, either simple orcompound. Zeolite will be a.com- pound salt, a bydrated silicate of alumina and soda, and -henee a compound of alumina not very dissimilar to alum. And topaz, the singular ingredients of which, discovered by aMr. Klaproth, have called. forth a query from the cele- brated Mr. Vauquelin, with regard to the mode of their ex- istence together™, will be likewise a compound salt, consist- ing of silicate of alumina, and fluate of alumina, Our acquaintance with the composition of the several Is zeolite a hy- drated tour- mineral substances, is yet far too inaccurate, to render it se aae possible to point out with any degree of certainty the one of which zeolite is a hydrate, however the agreement of the two substances in the nature of their constituent parts, and in their being both electrical by heat, directs conjecture towards tourmaline. St. James's Place, Jan. 22, 1811. - Addition to the Account of native Minium. ' After I had communicated to the President the account of the discovery of native minium, printed in the Philoso- phical Transactions for 1806+, I learned, that this ore came from the lead mines of Breylay in Westphalia. ~£3 XIE. Extract from ¢ Paper communicated to the American Philo. sophical Society on the Discovery of Palladium in a Native Alloy of Gold; by Mr. J, Croup, Director of the Chemi- cal Processes at the Mint of the United Statest, In 1807 about 820 ounces of gold bullion were brought Gold from into the. wint of the. United States. They consisted of 120 Fortuguese America. '* Annales du Museum d’Hist. Nat. tome 6, p. 24. ~ 4 See Journal, vol, XVI, p. 127. } Annal..de Chim, vol LXXLY, p. 99. small 138 NATIVE ALLOY OF GOLD AND PALLADIUM. smali ingots, each stamped on one side with the ‘arms *of Portugal, and the inscription Rio das montis, aud on the other with a globe. The fineness of each ingot too was marked on it. Among: these were two differing from the others so much in eobuiti that Mr. Cloud preserved one, weighing 3 oz, 11 dwts, 12 grs, to examine it.> _ cue Analysed, No silver, No metal easie ty oxidable. Gold. No platina. Some other. metal, Palladium, lowing were the experiments he made. Sib. 1. Nitromuriatic acid was employed on one portion of the ingot, to find whether it contained any, silver; dnd none was discovered. 2. Twenty four carats were mixed with 48 carats of: fine silver, and cupelled with lead, to separate any oxidable metal that might be present: but there was vo diminution of weight, consequently the allay contained no metal easily erty . The fine metals of the preceding onipenlinely were eins between rollers, and subjected to the action of pure nitric acid. The silver and the native alloy mixed with the gold, were dissolved by the acid, which acquired a deep brown red colour. The metal that remained, washed with pure water, and dried by the fire, weighed 22 carats 13 gr It had all the appearance of tine gold. _ 4, The metals not dissolved in the latter experiment were subjected to the action of nitromuriatic acid. The whole was dissolved, except a small quantity of silver, which had escaped the action of the nitric acid. The solution was as- sayed with muriate of ammonia, and other tests, from an ex- pectation of finding platina, but no trace of this metal was discovered. The gold thrown down was pure to 347 5. Pure muriati¢c dcid was poured into the metallic solu- _ tion resulting from Exp, 3, till the silver. was completely thrown down, and the acid was in considerable excess, None of the colouring matter was precipitated from the ‘so- Jution, which remained red, and did not appear at all changed, notwithstanding the precipitation of the silver, From these preliminary experiments it appeared, that the alloy was a compound of gold and some metal capable of re- sisting cupellation, and soluble both in nitric and nitro- murilatic acids, In adopting the following mode of analysis evident ‘ a ~ NATIVE ALLOY OF GOLD AND PALLADIUM. ' 139 evident proofs of the existence of a metal possessing all ‘the properties of palladium v ve obtaiged. I. The whole ingot was combined with twice its weight of Analysis of fine silver, and cupalled with ge equal in weight to the ‘Re whele. mixture. Il. The cupelled meta!s were reduced to thin plates, and kept in boiling nitric acid till the silver and palladium were dissolved. The deep brown red solntion was decanted, and the remaining gold washed with distilied water, which \ was afterward mixed with the decanted solution. Iti. Pure muriatic acid was added to the preceding solu- tion, till it was in excess, and nothing more fell down. The liguid retaining its red colour was decanted off, and the pres cipitate washed with distilled water. The waters of elutri- ation were added to the decanted liquor, which then held "nothing in solution but palladium. 1V, A solution of pure potash * was poured into the mee tallie solution of the preceding experiment, till the whole of the palladium was thrown dOwn in a brown floceulent pre- cipitate. This was svehed with distilled water, collected on a filter, and dried. V. A portion of the ‘precipitate obtained in this experie “ment was put into a crucible without addition, and exposed. to a heat of about 60° of Wedgwood; when a metallic button of palladium was obtained of the spec. grav. of 11-041. VI. Another portion of the precipitate of Exp, IV was mixed with black flux, and exposed to the same degree of heat as in the preceding experiment. The result was the same. _ A metal supposed to be palladium, thus obtained from a 7},, alloy Was source where it was not known to exist, required to be com- palladium ; pared with the palladium obtained from crade platina, to confirm its identity. Comparative experiments were accord- ingly made with prussiate of mercury, fresh muriate of tin, and other tests. The metals from these two sources did not exhibit the least difference. Native gold is never found perfectly pure. Hitherto it and no other was presente “* Carbonate of potash will not answer so well, because part of the palladium would remain dissolved in the carbonic acid. : has ‘\ 140 The cement described. Analysis of it. CEMENT OF AN ANCIENT, MOSAEC. 5 has always been seen alloyed with silver or copper, and fost- commonly with both, and ‘with other metals also. ‘The gold that was the subject of the preceding experiments ap- pears to have been alloyed with palladium alone. If it had been alloyed with any other metal, except silver or platina, the experiment No. II would have shown it; and silver would have been discovered by the first experiment, and platina by the fourth. ee eer Xi. / Analysis of the Cement of an antique Mosaic, found at Rome : by Mr. D’Arcet *, dl [S cement is of a yellowish white, very compact, with. out grains, and pretty hatd. It blackens a little in the fire. ‘Before calcination it effervesces briskly: but after it has been calcined, nitrous acid dissolves it without evolving any carbonic acid. In the former case a few yellowish flocks remain, and some fragments of a reddish browh ¢dlout, but little compact, and résembling the porous lavas, or puz- zolana. The yellowish flocks are destructible in the fire. Sulphuric acid precipitates nothing from these solutions, therefore they contain no lead, -Ammoniac throws down only a little alumine and oxide of iron. 5 gram. [77°29 ers] of this cemetit, calcined under a mf fle for eight hours, no longer effervesced, and weighed only 2°815 gr. [43°48 grs]; which indicates in 100 parts 56:3 of qaicklime; and | 43-7 of vegetable or animal matter and carbonic acid. 10 grammes of this cement left 4°1 of carbonic acid, when acted on by nitric acid. We have therefore in 100 parts 59 of quicklime and animal or vegetable matter, and 4} of carbonic acid. * Ann. de Chim. vol. LXXIV, p. 813. This cement was sent by Mr. Belloni, Director uf the Imperiat School of Mosaic, who considered it as one of the best cements the ancients had employed in the fabrication of their mosaics, and of their pavements in compartments. On / CEMENT OF AN ANCIENT MOSAIC. 1413 On comparing these two analyses we find, that the cement eontains in, 100. parts Quicklime <..6eccreccvencccecvconseses SHS Curbonic acid -occccrccccvacce: coecpecce Ak __Vegetable or animal matter ++++++sssseees 2°7 —100°0 In this cement, we see, the lime, if] it. were employed The kime quick, has_resumed: fromthe air, and:in, the lapse, of time, acai cigiaheid nearly-all the carbonic acid necessary for its saturation. This is the first. time of my observing this fact. As I'This singular: have never found the lime in mortar, however ancient, satu- rated with carbonic acid, I am inclined to suppose, that the vegetuble; or ‘animal,matter, that servedjas:.a. gluten, pro- How effected. moted:the absorption of carbonic acid; or rather, that the cement in question was made with carbonate of lime. (whit= ing), and not with-quicklime. Tn the latter,case about.97 parts of carbonate. of lime, and 3 of oil, glue, or cheese, uiust have been employed. In the former. the.eement would. have been:composed of. about 56) parts of quicklime, to 3. of vegetable or animal matter. It is obvious, that these proportions, which are found. at present to form the cement|in question, were not fntlowad in its preparation. -If oil were employed, it would have increased in weight in drying); and then less than 0-03 must have been iiacd, which appears to me impossible. . I is more than, probable therefore, that the earn em-.Its probable ployed was analogous to the caseous part of milk, and then ©°™Positione it would have diminished in weight by losing the water it contained, which: served. to reduce. to..a:paste the lime or carbonate of lime. From this analysis it appears,, that the cement was very simple ; and that those we now compose. on the same prin- ciple would become equally hard in time. x XIV, 142 ty: METEOROLOGICAL JOURNAL. PRESSURE, TEMPERATURE, Wind| Max. } Min Med. |Max.} Min | Med. |Evap.| Rain . — ef 8th Mo.. A gh AvG.11|N Wi 30°16] 29°86}:30°01 | 61 }42 | 515 [| — 5 12 |N WI] 30°16] 30°10} 30:13 | 64 | 50 | 57 wi 13\S W| 30°24] 30°10] 30°17 | 73 | 52 | 625 | +33} — 141N WI 30°25} 30°09) 30°17 | 66 } 47 | 56°5 “hee 15 1S W| 30°25} 29°97 | 30°11 | 68 f:51 | 595 | —J} — 16 |S W| 30°14] 29°97 | 30-055] 68 | 57 | 625 | 37) — 17 IN W| 30°13] 30°03] 30:08 | 70 | 45 | 57°5 | — 18! E | 30°03} 29°76] 29°895| 72 | 55 | 63°59 | =f al 19 |Var.| 29°72] 29°65| 29°085) 68 | 54 4 61 -30} 35 1@ 20] W | 30°05] 29°72} 29°885) 64 | 57 | 60'S | —] oS} - 21 |S W| 30:08 | 30°04) 50°06 | 68 | 56 4 62 22] W | 30°04} 29°92}29°908 | 71 | 52 | O6b'5 | 41f — 231 S | 29°921 29°73] 29°S825' 68 | 55 | 615 | —] 4 241 E | 29:73} 29:52) 29°625' YO | 55° | 625 | —F — 25 |S W] 29:70} 29°50} 29 60 | 65 | 48 | 56°5 1 16) °39 26 |S Wj 29°78} 29°70) 20°74 | 67 | 56 | 63°5 | — ° 271 W | 30°07} 29°74] 29°905] 68 | 44 | 56 fp Ay 28 |War.| 30°11} 30°03) 30 07 , 66 [51 | 58-5 | 42} 4 29 |S W} 30:17 29°96| 30-063 69 | 46] 575 | —]} 2 30 IN WI 30'20] 30°13/ 30165] 69 | 47 | 58 24 31 |S W) 30°02] 29°97 | 29°995) 71 | 53 } 62 ag 9th Mo. Serr. 1 |N W} 30°22] 30°02] 30°12 | 68 | 45.4 56°5 N | 30°29| 30°26; 30°275} 65 | 45 | 55 Oo N El] 36°29 }) 30°24-| 30-205) 64 |) 53 | 58°5 §.°34 N E} 30°24] 30°18/30°21 | 62 | 53 7 57°35 | — EF | 30°18} 30151 80°165} 71 4 52°] 615 | — E {30.17 | 30°83" 30°15 1-73 [44 4} 58°5 | °35 N Ej} 30°19 30°13, 30716) 72: }43 | 575) — E | 30°20}. 30°17 | 30.185; 74 | 47 | 60°5...})°29 co NTO) Gr Bm G9 09 —_—— | 30°29 | 29°50 '30°025| 74 | 42 | 59°20|3'14| «88 N.B. The observations in each line of the Table apply to a period of twenty- “four hours, begiuning at g A.M. on the day indicated in the first column. A dash _ denotes, that the result ig aucluded in the next following observation, NOTES METEOROLOGICAL JOURNAL. NOTES. Eighth Mo. 11. Cumulostratus, dense about noon, but which soon after dispersing, a brilliant sunset ensued. 12, a. m. cloudy: wind S.W. 13. A few drops at intervals: rain in the §. by inosculation. 14. a.m. Cumulus, with haze gradually increasing above: p.m. clouds below dis- perse: a fine elevated veil of cirrus, coloured at sunset. 15. Elevated clouds, with traces of cumulus: some large drops about noon: at sun- ~-set, the western sky richly coloured with red and yellow, on cirrocumulus passing to cirrosiraius: windy night. 16. a.m. Windy: p. m. small rain: clear evening, with coloured cirrus and cirrocumulus. 18. Evening, large cirri, pointing upwards. 19. a. m. Thunder showers, chiefly to S.S.W.and N. A strong variable charge in the insulated conducter. 6 p.m. Fair and windy, with cumulostratus. 20,21. Windy: much dew. 22. Light rain a. m.: showers p.m. 23. Misty morning: cumulus, with cirrostratus from the S.: about one, these inosculated, and showers prevailed, p.m. 24. Misty morning: cumulostratus:, a few drops of rain: evening, cirrostralus. 25. Misty, and raining at 85 a.m. Wind S. E. Hveniug, cumulostratus evaporating, beneath a veil of cirrus, which at the moment of sunset, was of a light silver grey, and during twilight, _ passed through yellow, orange, red, and purple, to dull grey; and lastly became again somewhat red: much dew, witha very moist air. 26. A small lunar halo, on clouds moving ina northerly current. 27. Windy, a. in. : smallrain, evening: much dew. 28. Windy. 30. a. m. Cirrus, with points dependent and crossing, and camulus forming beneath: at 9 Pp. m. -Cifrocumulus, with much dew. The barometer unsteady. 31. Fine day: cumulus, cirrus, cirrocumulus: a diffused blush on the twi- light, which begins to be very luminous. , } ene ie seals ote RESULTS. Wind westerly, with little exception, to the time of full moon, when it came round by N. to the Eastward. "Barometer: highest observation 30-29 in. lowest 29: 50 in. Mean of the period 30°025 in. Therm.: highest observation 74°, lowest 42°. Mean of the period 59'20°. Evaporation 3:14 in. Rain 0:88 in. L. HOWARD. PLAIsTow, | Ninth Month 26, 1811, 143 144 Inclination of. stems of plants toward the light, not from voli- tion or instinct, but known jaws of vege- tation. Etiolation, not a general but topical affection. Various de- grees of it. INCLINATION OF PLANTS TOWARD: THE’ LIGHT. XV. Remarks on the Inclination of the Stemsof Plants toward the Light: by M. Decanvoure™*.: Or all-the phenomenz that living vegetables exhibit, there are few appear so extraordinary, as'the energy and ‘constancy _ with which their stems incline toward’ the light. Not’ only has no explanation been given hitherto of this® facet’ by’ arly physiologist, but writers have even been found, who, more of the poet than of the naturalist, havé ascribed this ten- dency, to some kind of instinct or: volition in plants. I think I can proveinia few words, that it isa simple and ne- cessary ‘consequence of the known laws of} vegetations: What Dhaveto say in this respect will even appear of so'elemreritary a nature, that every one will be surprised not to have met with-in all books: and that I shall be pardoned"for’ writing it only, on account.of the wanderings, into’ which some have gone on the subject. se, a _ Everyone knows; that ‘the state of’ silvery whiteness/and extraordinary elongation; acquiréd’ by” plahts that'grow’ in darkness, is designated by the term etiolation. Allwho'have studied this disease know, that it is not.a’ general disease, but a local affection; as I. have. satisfied myself by: direct experiments. If we expose to the light of day an etiolated plant, in two days it wilthaequtre-a-green colour perceptibly similar to that of plants, which have grown in open day~ light. If we expose tothe light one part of the plant, be it jeat or branch, this part alone will become greea. If cover avy part of a leaf with an opake substance, this place will remain white, while the rest becomes green. The whiteness of the inner leaves of cabbages is a partial etio- lation, and a thousand other examples might, easily be quoted. Etiolation therefore is periainly, a local, and not a general disease. On'the’ other hand it is equally certain, that between complete etiolation and complete verdure eveFy possible in- termediate degree exists, determined by thé intensity “of the * Mém, de la Soc, d’Aroueil, vol. I], p. 104. light, ‘ - equally enlightened on all sides, as we see them in forests; = INCLINATION OF PLANTS TOWARDS THE LIGHT, 145 light. Of this any one may easily satisfy himself, by ate tending to the colour of a plant exposed to the full day- light; it exhibits in succession all the degrees of verdure. I had already seen the same phenomenon in a particular Etiolated ae : Mas plants ex d ‘ F pose manner, by exposing etiolated plauts to the light of lamps. tb acd In these experiments (inserted in vol: I, of the Mém. des light. Savans étrangers) I not only saw the colour come on gra- dually according to the continuance 6f the exposure to light ; but | satisfied myself, that a certain intensity of permanent light never gives to a plant more than a certain degree of colour. The same. fact readily shows itself'in nature, when we examine the plants that grow under shelter or in forests, or when-we examine in succession the state of the leaves, that for the heads of cabbages. . Now: let us examine the state of a plant, that is not Plants not ; equally ex. eae : zt wana 3 posed to light and still better in plants. cultivated in hothouses, or in come in forests, hot mon reoms. That part of the stalk which is exposed to the peu er least light must necessarily be a little more etiolated than " _ the otek: consequently it must elongate itself a little more, “while the fibres on the side next the ‘Tight must ‘become | on the contrary a little more short and stiff. But it is evident, incline to the that this inequality of elongation between the fibres of the Hiatt two opposite sides cannot take place without the extremity lation, of the stalk tending to incline toward the side where the fibrés are’:hortest; that is to say, on the side next the light. Thus it appears, if this theory be true, that the energys This iste . with which plante incline themselves toward the light, must ‘i propor- tional tot be proportional to the inequality of the light they receive degree paw on opposite sides, and to the greater or less propensity to affection. etiolation, that each plant, or part of a plant, possesses, in consequence of its structure. This I shall proceed to prove by facts, most of them, it is true, already kuown, but which ‘ will be so many coffirmations of my hypothesis. The parts of plants liable to etiolation alone possess this Only parts of tendency to incline toward the light.’ Of this any one may plants liable ro etiolation ine , satisfy himself, by examining ae branches directed toward cline toward the windows ina greenhouse not well lighted. He will find, the light. that they are always the young shoots, capable of emitting oxigen gas, that direct themselves toward the light; and “Vou. %XX.—Ocr. 1811. ee ies _ thet 146- INCLINATION OF PLANTS TOWARDS THE “LIGHT. that the energy of this direction is greatest ‘in ‘the most herbaceous ‘stalks, in which the phenomenon of etiolation is'also most remarkable. . In forests the woody branches or stems themselves may frequently be observed twisted to gain, ‘an open place; but this.is*because the unequal distribution - of light ‘has continued several years; the.» branches -were bent in their green state, and have acquired»solidity m that in which they are found. . Of this I have ‘satisfied myself by direct measures. Permit me here to observe, thatit may be possible to avail ourselves of this property of vegetables, to formed curved timber for the purposes of the arts, by: directing the light on certain trees in a suitable manner. © - The inclinae «© Ln’ the instances "Il have quoted 1 it may»be supposed, that, oie ar if old branches do not bend, it is‘solely on'account of their to the flexibi- hardness: and indeed it is evident,- that, the more flexible Nitys the branch, the more will it be bent by the same quantity of ‘partial ‘etiolation ; but?a striking example’ will provey but does not that the inclination towatd the light'does not take. place im anata the most flexible branches, when they want the faculty: sof ble of decom- decomposing carbonic acid gas by means of light: This 6X akira - “ ainple is dodder. I have satisfied niyself by. direct experi- as'dodder, ‘ments, ‘that it does not incline itself toward the light; that, . placed under waterin the sun, it does not deanipbsé car= bonic acid gas, and consequently can Minders itself ey on both sides, though unequally illumined. bs It depends The whole ofthe phenomenon then consists in the puptne ona partial elongation produced by etiolation. But it is known, that elongation of =. if : ; ; : the vessels, the elongation takes place chiefly in the vessels, which draw, eds te along with them as it were the cellular texture. © Conse- quently, the more vessels there are in a plant, ora part of a plant, the more it ought to incline toward-the light. In and is scarcely plants totally destitute ‘of vessels, this inclination “must be oa ana scarcely perceptible, because the rounded Cells grow mearly of spherical alike in all directions: hence: this. inclination toward the cells, > fight as, next: to: nothing i in the cryptogamia, as in certain Ney alge composed solely of rounded cellular texture. | 'Those but of the cryptogamia, which, as the mosses for example, are “% * gomposed of two sorts of cellular texture, one with rounded j the’ other with tubular cells, approdch the vascular plants in consequence of the lattery: win i 1s" ecapaie of more or told “A 18h wWwaGe 2S oMess ca ON. [HE FORCING-HOUSES OF THE ROMANS. less elongation; and,in these we may observe a. slow and feeble inclination toward the light. Lastly, plants furnished with vessels, and of these plants the stems, in which vessels most abound, exhibit this inclination most forcibly, I conceive therefore I have proved, by this combination of facts, that ihe hitherto unexplained phenomenon of the inclination of the stems of plants toward the light is rea- dily reducible to, the known laws of etiolation. | Me 2% XVI. \ b.. 30 di On the Forcing-houses of the Romans, with a List of Fruits cultivated by them, now in our Gardens.’ By the Right ‘Eon. Sir Josrrn Banks, Bart. K.B. P.R.S. §¢.* Mk. : A. Knight was the first person among us members of. the Horticultural Seciety, who -observed, in reading Martial, strong traces of the Romans having enjoyed the luxury of forcing-houses. I shail cite the principal passages upon which he has founded this observation, the truth of which is not likely to be controyerted, and. add such ree harks as present themselves upon the Roman hot-houses, with a few words on the subject of our own, The first epigram is as follows : they vb ne Cilicum timeant pomaria brumam, ’‘Mordeat et tenerum fortior aura nemus, “Hibersis objecta notis speeularia puros ~ Admittunt soles, et sire feece diem, &c, | Martial; lib. viii, 14. SEER Bye $ { ; Qui Corcyrzi vidit pemaria regis, Bus, Entelle, tue preferat ille domus. david purpureos urat ne bruma racemos, Et gelidum Bacchi munera frigus edat ; Etaite perspicua vivit vindemia gerama, _ Et tegitur felix, nec tamemjuva latet. * Trans. of the Hort. Sac. vol. i p. 147. id eS L@2 Femineum 147° The Romans | as aeeeinee Proofs of thiss ere 148 ON THE FORCING-HOUSES OF THE ROMANS: Feemineum Jucet si¢ pér bombycina‘corpas ? Calculus in nitida sic numerator aqua. © Quid non ingenio voluit natura licere?. niisigasthoa stevilis ferre jubetur hiems.. Martial, lib. viii 6s. — The four last lines of the. first epigram ‘are omitted, as. having no reference whateyer to the subject, Their mode of Fron these passages, and from. that of Pliny, ii in which ~ ne eh he tells us that Tiberius, who was fond of cucumbers, had them in his garden throughout the year by me means 18 of (spe- cularia) stoves, where they were grown in boxes, wheeled out in fine weather, and replaced in the nights or in cold weather; Pliny, book xix, sect. 23,.we may. safely infers that forcing-houses. were not unknown to the Romans, | though they do net appear to ae been carried into. eae 4 rat use. Flues incom. Flues,the Romans were well acquainted with ; they did | mon Use not use open fires in thejr apartments as we do, but, in ‘the amorg them, ” ere odeolder countries at least, they’ always had flues under the floors of their apartments. Mr. Lysons found the Altes, and. the fire-place whence they received heat, in “the Roman villa he has described in Gloucestershire; in ‘the ‘Daths also, which no good house could be without, flues were used to communicate a large proportion of heat for their sudatotics, or sweating apartments. - They used The article with which their windows were glazed, if the ty ie ae term may be used, was talc, or. what we call Muscovy glass, (lapis specularis). At Rome, the-apartments of the better- most classes were furnished with curtains (vela *), to keep away the sun; and windows (specularia T), to resist cold ; so common was the use of this material for windows, that the glazier, or person who fitted the panes, had a name, and was Called specularius. ol The fret epi. On the’ epigrams the following remarks present’ gait gram relates to selves, ‘The iitst in all probability described a peach-house, a peach-house, é the word pale, which: is meant as a ridicule’ upon the prac- stare b ; SFiS Transparent * Ulpian |. Quzsitum 12.’ 2TH@ Romans also made transparent bee- bee-hives, hives of the same material. Pliny, lib. xxi, sect. 47. | ' t Quamvis coenationem velis et specularibus muniant, Senecas Dus md e J tice ON THE FORCING-HOUSES OF THE ROMANS. yap tice, gives reason for this’supposition ; we all know that — _ peaches grown under g\ass cannot be endowed either with colour or with flavour, unless they are exposed by the re- _ moval of the lights, from'the time of their taking their se- sond sweil, after stoning, to the direct rays of the sun: if this is not done, the best sorts are pale green when ripe, and not better than turnips in point of flavour; but it is not likely, that a Roman hot-house should, in the in- fancy of the invention, .be furnished with movable lights, as ours are. The Romans had peaches in plenty both hard They had so and melting*. “The flesh of the hard peaches adhered to S°fs in eee the stones as ours do *, aud. were aactnath in point of fla- your to the soft ones f. fi The second epigram refers most plainly to a grape-house, The second ‘but it.does not'seem to have been calculated to force the Pigram de- erop.at an earlier period than the natural one; it is more Aig ur ~ likely to have been contrived for the purpose of securing, a tor late crops. Jate crop, which may have been managed by destroying the first set of bloom, and encouraging the vines to produce a second, The last’ line of the epigram, which states the office f.the house to be that of compelling the winter to produce autumnal fruits, leads much to this opinion. + Hot-houses seem to have been little used in England, if Hot-houses at all, in the beginning of the last century. Lady Mary 5 ey known a cen- ” Wortley Montagu, on her journey to Constantinople, in the tury in Eng- year 1716, remarks the circumstance of pine-apples being /and. served up in the desert, at the Electoral table at Hanover, as a thing she had never before seen or heard of ;: see her Letters. Had pines been then grown in England, her lady- ship; who moved in the highest circles, ‘could not have been 4 ignorant of the fact. The public have still much to learn on the subject ‘of: hot-houses, of course the Horticultural Pwitty have much'to teach, ‘ - They have, hitherto been too frequently rieapnbih beac Misapplied as the name of forcing-houses, to the vain and ostentatious forcing- purpose of/ hurrying fruits te maturity, at a season of the i year, when the sun has not the pawer of endowing them with their natural flavour; we have begun however to apply | : * ¢ © Pliny, lib. xv, sect. 34, + Pliny, lib. xv, sect. 11. ‘ them ‘ I50 Their proper - uses, They will be much ime royed, Fruits that will soon be cultivated in thein. ON THE FORCING-HOUSES: OF ‘THE ROMANS. thein to their proper use, we have peach-houses built for the purpose of presenting that.excellent fruit to the sun, when his genial influence is the most active. We have others for the purpose (f ripening grapes,,in which they are secured from: the chilling effects of our uncertain autumns, and we have brought them .to as high a degree of. perfection here, as, ei.her Spain, France, or Italy can boast of, .We have pine-ouses also, in-whico that delicate fruit is raised in a better style than is generally practised. in its native in» teriropical countries ; except, perhaps, in the well managed gardens of rich individuals, who may, if dae care and atten- tion is used by their gardeners, have pinesas geod, but. cane not have them better, than those we know how. to grow in » England. | mts py heyy Bh shawna cis fF ‘The next generation all no doukt erect cscs of much larger dimensions than those, to which we have, his therto confined ourselves, such as.are capable. of raising © trees. of considerable size; they will also, instead of heate ing them with flues, such as'we use, and which waste in the | wails thet conceal them more than half of the warmth’ they receive from the fires that heat them, use naked: tubes’ of meta! filled with steam * ‘instead of ‘smoke. Gardeners will'then .bé enabled to! ddmit' a :proper proportion. of air to the trees in -the season‘ of flowering; and as we already -are aware of the use of beesan: our cherry-houses to distri. | ‘bute the pollens: where wind cannot beadmitted to:disperse it,: and. of shaking the trees wheb:in full bloom; to, put the pollen in, motion, ithey will find no: ie fits in setting the, M4 shyest ‘kindsof fruitss: oa) cant aos tj fold. anata d It idoes not require the gift of ree to,foretelly that ere-long the aki andthe avocado pear of the, West; Indies, : the. flat peach, the .mandarine- orange,’ and the litehi: of China, the mangot, the mangostan, and :the,durion of the. East saint and: pee hy other valuable :fruits,. will be fre- Fs vt HPO to arena ots uM; tA neat and ingenious pe for, heath, melon frames;by, stean ap-, peared in the Gentleman’s lagazine for January, 1755, Pip + The mango yas: ripened by 1 Mr. _ Aiton, his Majesty’ s gardener, in’ the Royal Gardens at Kew, i in the autumn of 1808, who has frequently ripened fruits of the miSspae TaEORIe, vhs is a Sy but not a su- perior fruit. ahs ‘ ! quien ‘ ON THE FORCING-HOUSES OF THE ROMANS. 151 quent at the tables of opulent persons ; and some of them, perbaps in less than haif a centur y, be offered for sale on every market day at Covent Garden. Subjoined is @ list of those fruits cultivated at Rome, in the time of Pliny, that are now grown in our English. gardens, si. Almonds. —Both Sabet and bitter were aha atonts ; “Modern fruits - Apples.—22 sorts at least: sweet apples (melimala) for Por eating, a others for cookery. They had one sort without ; kernels. : ie vis says of the apricot Paredebigea! que sola et odore commendantur, 2b. xv, sect. 11. He arranges - them among ‘his plums. Martial valued them little, as appears by his epigram, xii, 46. . (Cherries were introduced into Rome .in the year of the city 680, 73 A. C. and were carried thence to Britain . 120 years after, A. D. 480. The Romans had eight kinds, : a red‘one, a’black'one, a kind so tender as scarce to bear any carriage, a hard fleshed one (duracina) like our bigare reau, a small one’with a bitterish flavour (/aurea). like our ~ little-wild black, also a dwarf one not exceeding three feet high. .- . ty le had six, ‘eas some more easily sepae . rated from the skin than others, and one with a red akin 3 : thy? roasted them as we do. :. -Figs.—They had. many. sorts, black said wie: lange and small, one as. large as a pear, daother: no larger than an olive, . Medlars.—They.had two Hinde she one Jarger, daa. thie other smalier. . | - _ Mulberries.—They had two kindavof. the black sort, a. larger and a smaller, Pliny Speaks. also of a mulberry growing on a brier: Nascuntur et in rubis, l. xv, sect. 27; but whether this means the rgspbewrys or the common blacks berry. does not appear. Nuts—They had. bazle-nuts and Glberds; (has quoque mollis protegit,, Barba 1, 15,. sect. 24: they roasted these hats. my oe Pears.—Of these fies banal many socte both eal sak winter fruit, melting and hard,,they had more than thirty . i pes SIX 159 Fruit culti. vated in Enge Jand.in the 16th century. Thomas Tuse ger, ON THE FORCING HOUSES CF THE ROMANS. six kinds, some were (opie. edhe we Hthe = our pound pear, Plums. —They had a multipl: eit of sorts, (ingens turba pruaorvm) black, white, and Variegated, one sort was called asinina, from its cheapnéss, another damascena, this had mach stone and little flesh: from Martial’s Epigram, xiii, 29, we may a annee that jt was’ what we vow call prunes, a Quinces.—They had three softs, one was called chrysos | mela frony its yellow flesh; they boiled them: with honey, as we make marmalade. See Martial, xiii. 24, ' Services. —They had the apple shaped, the ‘peat-shaped; and a small kind, probably the same as we gather wild, pos=" sibly the azarole. Strawberries—they had, but do not appear ‘to have prized, the climate is too warin to’ ‘produce this sii in Lita : fection unless in the hills. Vines.—They had a multiplicity of sted! wth thick © skinned (duraciva) and thin skinned: one vine growing ‘at: Rone produced 12 aniphore of juice, 84 gallons. © They had round berried, and lovg berried sorts, one so long, that it was called dactylides, the grapes being like the fingers on™. the hand. Martial speaks favourably i ai Gare fie grape for eating, xii, 2% Walnuts.—They had soft shelled, and hard shee, as we ' have: in the golden age, when inen lived upots acorns, ‘the gods lived upon walouts, hence the name jugians, Jovis glans. We ree ‘Asa matter of curiosity, it has also been deemed expe- dient, to add a list of the fruits cultivated in our English gardens, in the year 1573: it is taken from a book entitled Five Hundred Points of good bt ak &e., by’ ‘Thomas Tosser. } Thomas miavek? who had received a Abeta education at Eton school, and at Trinity Hall, Cambridge, lived many years asa farmer in Suffolk aud Norfolk: he afterward removed to London, where he published the first edition of his work under the title of One Hundred Points io good Husbandry, in 1557.00 In his fourth edition, from which this list is taken, he’ . ‘ firat ON THE FORCING HOUSES OF THE ROMANS. first introduced the subject of gardening, and has given us hot only a list of the fruits, but also of all the plants then’ cultivated in our gardens, either for pleasure or profit, un- der the following: heads. - | Fe. Seedes and ‘herbes for the kychen, herbes and rootes. for Objects of sallets and sawce, herbes and rootes to boyle or to butter, etrewing herbes of all sorts, herbes, branches, and flowers for windowes and pots, herbs to still in summer, necessarie herbés to grow in the gardens for physick not reherst before. gardening at that time, . This list consists of more than 150. species, beside, the fole lowing fruits., Apple trees of all sorts Apricockes Barberries | Boollesse. black and white Cherries red and black Chestnuts ‘Ga *Cornet Plums - Damisens white aud black Filberds red and white Goseberries .. Grapes white and red | ~ Grene or Grass plums List. of old Mulberry English fruits. tPeaches white and red Peeres of all sorts Peer plums black and yellow Quince Trees Raspis { § Reisons . / Small Nuts Strawberries red and white Service Trees » Wardens white and red | Wallnuts + Hurtil-berries Wheat Plums Madlets> ‘or sou ® Probably; a, fruit of cornus sek MNT, ila called cornelian . cherry, fh, Hurtleberries, the fruit of vacinium vitis pee though no Jon ger cul- tivated in our gardens, are still esteemed and served up at the tables of opulent people in the counties that produce them naturally. They are every. year brought to London from the rocky country, near Leith Tower in Surry, where they meet with so ready a sale among the middle classes ef the people, that the richer classes searcely know that they are to be bought. } The yellow fleshed peach now uncommon in our gardens, but which was” frequent 40 years ago, under the name of the grange peach, was called by our ancestors melicoton, § By reisons it is probable that evrrants are meant ; the imported fruit _ of that name of which we make puddings and pies was called by our ane sestors raisin de Corance, - Though oH ‘ 154 BY .yp BRERARATION QF-OX*GALL, w . _ Though the fig.is. omitted by ‘Tusser, it was certainly, in-. treduced.into our gardens bejore he wrote, » Cardinal Pole is saidjto, have, imported from, italy that.tree,. which 3 qs. still. growing in the garden of the ar chbishop’s; palaces: at! Lam- hi) piney Obeth. Soot bas vali coofaed eer hesdagi fev Method Hh ohay preparing Ox-Gall in a > > > . $55 It is also of great use to housekeepers, Sailors, and others, and for cleane rece drmwollen clotives from grease, tar,’ &e.; and’ will be weesana aes ‘fowrid advantageous for many other purposes. ‘ If it should meet with-the approbation of the Society, I | have no objection to prepare it for sale. yURiens: «t: toidis dea ‘L am, Sir,: basin oe SS col. Your obedient Servant, Benet) odin to RICHARD CATHERY, “9 Fi, : pet West aK aks ication Process for preparing Or-Gall i in a edteeatrated state, by . by. Mr. Cathery. We: i “9 yt rh eT? 6) Meco a ‘gall NER [al the Ox, and put it into a basin, Tet Method of pre« its stand all night to settle, then pour it off from the sediment paring it. into, clean earthen mug, and set it ina saucepan of boiling water, over the fire, taking. care that none of the water gets mto. the, mug. Leti it boil till it is quite thick, then take it out and spread i it ona plate or dish, and set.it before the fire to evaporate >, and when as dry as you | can get it, put it into small pots, and. tie papers over their tops to aegR the dust fiom. it, and i it will be good for years*. Certificates were received from Mr. Gabriel Bayfield, No. Testimonies of 9; J Park, Place, Walworth ; and Mr. William Edwards, No. - ae Xd Poplar Row; dy both botanical, colourers ; ; stating , that . hha ave used the ox-gall_ prepared. by Mr. Bsthecvs and dud to answer ‘better than gall in 4 liquid state; that this | preparation is is, free from disagreeable smell, and is much cheaper, a as one 0x- -gall thus prepared will last one person for two © years, and, he as fresh as if just taken from the ox. © Ch ertificate v was received from. Mr. James Stewart, No, and at sea. 26, St. Martie Q s , Street, Leicester Square, stating, that he lately belonged t to, his Majesty’ s ship the Vestal frigate, and that, he- took out with him, 10 a voyage 1o Newfoundland, ae large:pot of the prepared ox-gall, for the purpose of wash- ing. -his greasy clothes, for two years; that he found it very senwiceable, a and to keep, its virtue as well as the first day. ## Gall Will'keep sdme time, if merely’ boiled so as to separate the albu- ” minous part, agreeably to the directions: of Mr. J. Clark, or professor Proust. See Journal, vol. XVI, p. 341. Cc. XVHI. } ‘ 156 NEW PROCESS! FOR MAKING (‘THE “ARBOR DIANZ. tai XVIII. | Kc ittn es Mr Vitalis, Professor of Chemistry at iulon: to Mr. Bouillon-Lagrange, on the ata . aed « amd Silver called Arbor Dien’. Li, $54 rod SF Asbo: Gre "Pue process meutioned by sing which is generally capable of be- folJowed for obtuining the peculiar amalgam of mercury and ing taken out of the vessz} in Silver, known.in chemistry by the name of arbor Dianw, is eee not the only one éapable’ of affording those beautiful crys- talline figures, that distinguish this curious production. [ have obtained the same object by an alteration i in the com- mon method, that enables me very easily to remove the me- ° tallic arborization from the liquid in which it is formed, and thus to keep it in another vessel unaltered. chs The process is very simple. In the nitric solutions of mercury and silver, both fully saturated, and diluted with the quantity of water directed by Baume, | suspend 5 or 6 drachims of very pure inercury, tied ‘up in a piece of fine li- nen doubled. The metallic solutions soon penetrate to the mercury enclosed in the cloth; and we presently perceive clusters of beautiful needles forming round it, and adhering to the nucleus of mercury. These needles gradually'i iherease ‘ in bulk, and in a short time extend above, an inch in Tength. Method of ree When the metallic arborization ceases to increase, the bag moving it. —_ Joaded with beautiful needly prisms, which appear to’ me to be tetraedral, is to be taken out; and, by means of ‘the aitk thread, with which it was tied up, fastened toa ‘cork. ‘The whole is then to be suspended under a small glass j jar, in ‘the midst of which the metallic crystals may be preserved as long as we please. I havea crystallization « of this kindi in my laboratory, which has retained all its beauty ‘these two years. Probably the The solidity of the metallic crystals obtained by my ‘Tie= ; proportions of thod, compared with the weakness of the threads that form the amalgam different, ‘the common arbor Diane, lead me to’ suppose, that the pro< portions of mercury and silver. are not the same in the two cases; and I would have endeavoured to ascertain the differ- ence, if Mr. Vauquelin, to whom JT have communitated ‘the fact, had not undertaken, to remove every doubt. on ous head by a comparative analysis. * Annales de Chim. Vol. LXII, p. 93, igi Process. & ae “The / SCIENTIFIC: NEWS« 157 ; = The. different configurations of the crystals too may Give)as are the tise to some interesting researches, which 1 have not yet ‘had pas a time to pursue. | sabe 4s vfs SQIBNTIFIC. NEWS. . FecKry " ; ‘ . : ; Me. Heinekin having exposed a solution. of very pure Solution of carbonate of. potash to the action of the galvanic pile; found, omeens iS 1) = that in three or four days the liquid next the hegatiye pole phe! by galva- had acquired a golden ‘yellow colour; and a very decided nism, smell of oximuriatic acid was perceptible. With the ni- and oximuri- atic acid forme ‘ trates of silver and of mercury the yellow liquid formed a 235 grumous precipitate; and it completely destroyed the co- lour,of litmus blue, and of ink. -The liquid next the po- sitive pole was highly caustic.. The conclusions he draws are, that potash and oximuriatic acid are composed of the game principles, or of carbon, hidrogen, and oxigen. in different proportions. — i , Ata is a circumstance not a little remarkable, that Mr. Opinion of, vt et and Dr. Davy were led to form similar notions pa Pate 2 of the. oximuriatic acid about the same time at Paris and ape haan London, - From the circumstances of the times it may be muriatic gas. ayerimet that there could be no communication between m; but it is probable, that, though the merit of discover y is 5 equally due to both these gentlemen, if it be not a fale lacy as some suppose, the priority rests with Mr. Curaudau, as his paper was read to the French Institute 6n the 5th of March, 1810. The following is one of the experiments, on which Mr. Oximusiatic Curaudau founds his opinions By combining oximuriatic g25 forms a union with gas directly with nitrate of silver a precipitate is formed, metallicsilver, without any oxigen being disengaged; and, as the weight of| the precipitate ave down is proportional to that of ' the gas employed, he infers, that it is a compound of the muriatic radical and silver. He infers farther, that in this procese the hidrogen of the acid disoxidates the silver; and the silver thus disoxidated enters directly into combination with. the muriatic radical, so.as to form a muriuret of silver. Hence we see, why potash in, the humid way, and carbon in, eat; . the 158 SCIENTIFIC NEWSe the dry, will not decompose this ealt :and why, on'theother “hand: hidrojen'so easily effects the reduction of the metal. and with 0:03 of hidrogen com poses™mu- static acid, Three meteoric stones, The proportions assigned by Mr. Caraudau to the muriatioe acid are one part of hidrogen to thisty-thige.of- oximuriatic gas. Qn the 23d of No vembery 1810, at half after one in the afternoon, three atmospheric stones fell in the commune of Chatsouville, canton of Meung, ‘departenent of the Loiret. Their! fall: was accompanied by a' series of: detonations,’ which preceeded it, and lasted some minutes. » The‘sound’ of the explasions, to: the number of three or four; followed: by a runibling noise occasioned by the echoes, was heard as* - Joud at Orleanis as at’ the place where the stones fell. “It 'is’ Circumstances of their fall. The stones de- * scribed. said it was equally loud ‘at’ Montargis, Salbri, Vierzon, ‘and’ Blois, at ‘all which places it excited alarm,’ being supposed to arise from the blowing up of a powder magazine!’ The: explosions _ must rage oe have: bie sia ape at a Di sige height. se ie hi. The fall of these stones was venetian! aod without the appearance of aity light, or ball of fire. ‘One’ fell at Montelle but has not been found. - The other two fell’ one | at Villenai, the other at Moulin Bralé. Ali these places are within the distance of a mile. One of the stones weighed . about twenty pounds; it made a hole in the ground just . large enough for its admission, in a perpendicular direction, dtitidt up the earth to the’ height of eight or ten feet. . The stone was taken out half an hourafterward, when it’ was stillso hot, that it could searcely be held in the hands.’ It had a strong sinell of gunpowder, which it tetdined ti it was quite cold.) The second stone formed a similar hole three feet deep. It ‘weighed forty pounds, and was! not’ taken out of the ground for eighteen hours after its ris when it was without heat. ‘Fhese ‘stones were both shapeless masses, srvegutdrly rounded at all their angles. . They contain rather more fér- ruginous gisbules, than’ those that fell at PAigle, in Nor- thandy ; these globules are somewhat larger and’ the ‘co-! ‘lour ‘of the stove, when broken, is lighter. They are quickly oxided,’ very heavy, sufficiently hard to seratch” et broken with difficulty, and the fracttre: is irregulae and SCIEN TI TIC: NEWS. 159 and very fine grammed. “The external'crustis a «quarter of a dine thick, and ofia: blackish gray. colours \The'substance of the stone ‘1s marked with a few bjack lines, irregular, _ very distinct, and from ‘half a line totwo ities broad. ‘Phey traverse it jndiscrimi nately i in all directions, hke the veins of certain marbles. Does not. this seem to indicate,. that they existed previous to their fall, and were formed inthe same ‘manner as rocks, .and- not_in. the atmosphere? The day when these stones fell was remarkably calm and serene; the sun shone as bright as in one of the finest days of “du- tumn ; and not a cloud appeared above the horizon. eet sions oe sailing to ed from. the East Indies, ae Direttions re New ‘Holland, Cape of Good Hope, : and the interjacent Sailing tothe East Indies &te parts, compiled chiefly from Original Journals. at the East India House, and from “Journals. and Observations made during: Twenty-one Years Experience. navigating in| those Seas; by James Horsbuyg,F.R.S. Part I, published. 1809, quarto, 389 - full) pages with side notes, contents, and a copious index,—Pazt II, corresponding size and type, 506 pages, just published. » Sold by Black Parry, | and Kingsbury. ‘This valuable publication cannot, fail to be of great utility to British. navigators, who trade: to the qeuakaied of the equator, as well as those belonging to his Majesty’s navy. Exclusive, of sailing: directions and local descriptions of winds, weather, currents, ports, headlands, islands, coasts, dangers, &e., the geographical situations of all the particu- lar headlands, islands, ports, and dangers, are stated from : actual observations of sun, moon, and stars, or by good .chronometers. ‘The necessity of a work of this nature has Jong been. known. to navigators ; ‘as, former directories having : been compiled from a mass of heterogeneous and very incor= rect materials, obtained when-shi ps were navigated by dead reckoning, prior to the application of marine chronome- ters and lunar observations to nautical science ; and these directories, for the greater part, having been generally transcribed from each other for nearly a century up to the present time: they are constantly fraught. with errour, and of jittle use in the present improved state of navigation. Upon’ - 160 Medical and chemical lec» tures. Lectures'on ‘surgery and physiology. SCIENTIFIC NEWS. i Upon this work the author has bestowed nearly ‘five years of almost constant labour, in order to render it as correct as possible, conformably to the important end he ‘had in. view, which was the security of the lives and pro- perty of numbers in a great commercial nation.» How far this end has been attained, ‘scientific and naval men can justly, appreciate. Medical and Chemical Leciures, St. George’s Hospital, and George Street, Hanover Rats 4) yes These Medical Lectures will recommence as usual in the first week of October, at eight in the morning; and the Chee mical at a quarter after nine, at No.9, George-street, Hano- ver-square. . Clinical Lectures are given on the cases of patients regis« tered in St. George’s Hospital, every Saturday morning at nine o'clock; by: George Pearson, M.D. F.R.S., sen. phy- sician to St. George’s Hospital; of the College of Physi- cians; honorary Fellow of the Imperial Mediinehinuidival ‘ Academy of St. Petersburgh, &c. | aan MRT = Lectures on Surgery, and on Physiology. Mr. A. Carlisle F.R.S. F.L.S. professor of Anatomy in the Royal Academy, and surgeon to the Westminster Hospital, will begin his Course of Lectures on the Art and Practice of Surgery, on Tuesday, October 8, at eight. ft) “clock in the evening, at his house in Soho-square. | The subject will be continued on Taree Thursdays, and Saturdays, at the same hour. The Diseases and Accidents allotted to the province of Surgery will be fully treated of, and illustrated by Cases from the Lecturer’s experience. The different Operations will be demonstrated, and the Anatomy of the Parts explained. _ These Lectures combine Views of the Natural’ History, Physivlogy, and Pathology of the Human Body , calculated to illustrate the several Processes of Healing, and to sis a compendious View of the eal Beonsisit, certain angle by the surface of a diaphanous body, it ac- A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND | THE ARTS. eee NOVEMBER, 1811. ARTICLE I. On.a Property of the repulsive Forces, that act on Light: by Mr. Mauus*. In my last papert I announced, that light reflected from New properties the surface of transparent bodies acquires new properties, a eee which distinguish it essentially from: that which emanates directly from luminous bodies. 7 I have since continued my researches on the same sub- Investigaticu ject; and, subjecting the results of my experiments to cal- continued. culation, I have arrived at some remarkable consequences, which tend to elucidate the mode of action of substances on light. - ‘1 had observed, that, when the light is reflected under a Reflected light acquires the 3 ij : roperties of quires the properties of the rays, that have been subjected to light doubly double refraction; and, setting out with this remark, I con- Tfacted. _ trived to modify the rays of light by simple transparent sub- The partial re- , : it flecti stances, so that they entirely escaped the partial reflection, Fanbaeere which is commonly observed at the surface of these sub- substances stances. I cause any number of these substances to be ? Jib * Mém. de la Soc. d’Arcueil, vol. Il, p. 254. Journal, p. 95. Vou. XXX. No. 138.-Nov. 1811. ~ M traversed 16% PROPERTIES OF LIGHT. traversed by a solar ray, without any of its particles being reflected; which furnishes means of measuring with accu- racy the quantity of light, that these substances absorb; a problem, which the partial reflection had rendered impossi- ble to be solved. and from The light that has undergone this modification comports opake polished . : ip : Py ‘ bedics, itself in a similar manner with opake polished bodies. Under determinate angles it ceases to be reflected, and is totally absorbed, while within and beyond these angles it is in part reflected from the surface of these bodies. Direct rayon When a solar ray is made to fall on a polished glass, that 5 anal is not silvered, this ray is in part reflected at the first and second surface, and its intensity increases with the angle of incidence, reckoning from the perpendicular: in other words, it is so much the greater, in proportion as the ray 1s more inclined to the reflecting surface. Light previ- But if the direct light be subject to this law of intensity, ously reflected that which has been already reflected follows a very dif- follows a dif- awe ferentlaw. ferent law, when it is reflected anew by a second glass. In certain directions, instead of increasing in intensity with the angle of incidence, on the contrary it diminishes ; and, after having attained a certain minimum, begins to increase ac- cording to the same law as the direct light. These minima are relative either to the inclination of the ray to the re- flecting surfaces, or to the angles which these surfaces form _ with each other, so that the light reflected by the second glass is a function of these three angles. This function has an absolute minimum; that is to say, a point at which the intensity of the light reflected by the second glass is alto- gether null, Calculation has led me directly to the cir- cumstances, that produce this mibimum; and I have veri- fied it by a very simple experiment, which I shall proceed to describe. : F Angle at If we take two glasses inclined to each other at an angle which allthe of 70° 22’: if we then conceive between these two glasses a oe Stic line making with each an angle of 35° 25', every ray re- absorbed by a flected by one of the glasses parallel to this line will not be aga reflected anew by the second; it will penetrate it, without any of its particles experiencing the action of the repulsive forces, that produce the partial reflection. Within or bee yond PROPERTIES OF LIGHT. 163 yond the angles I have mentioned, the phenomenon will ' cease to take place; and the farther we go from these limits, on either side, the greater will be the quantity of light reflected. This faculty of entirely penetrating transparent Edis; This property which the light has acquired by its first reflection, it will Nimmo ae lose or retain in varivus circumstances, which 1 have stu- ee ines died; and thus I have been led to the following law, ac- stances. cording to which this singular phenomenon is effected. If a second glass be made to turn round the first re- aw of this fiected ray, a, constantly making with it an angle of 35° phenomenon. 25°; and if ina plane perpendicular to this ray we conceive two lines, one, 8, parallel to the first glass, and the other, c, parallel to the second ; the quantity of light reflected by the second glass will.be proportional to the square of the cosine of the angle included between the lines bc: it is at its maximum when these lines are parallel, and null when they are perpendicular. So that the limits of the pheno- meuon are relative to three rectangular axes, a, b,c, one of which is parallel to the direction of the ray, another to the first reflecting surface, and the third is perpendicular to the two former. For the second glass let us substitute a metallic mirror, Metallic mir- and call the rectangular axes of the second ray, analogous As substitared or the second to the axes a, b, c of the first, a’, b,c’. If this ray be re- glass, ceived on a polished but unsilvered glass, which makes with it av angle of 35° 25’, we shall perceive the following phe- nomena, which are independant of the angle of incidence on the metallic mirror. If’ be parallel to 4, that is, ifthe metailic mirror be parallel to the axis 6, the ray it reflects will retain its pmperties with respect to a glass situate pa- __ rallel to the axis c’; it will penetrate it entirely. . If b’ be parallel to c, the reflected ray will retain its properties for a glass parallel to the axis 0’. In the intermediate positions, the quantity of. light, that will have retained its property for a glass parallel to the axis b, is proportional to the square of the sine of the angle comprised between the axes 5° 4; and that which has Tee 2 tained its property with respect to @ gless parallel to the © M 2 axis 164 PROPERTIES OF LIGHT. axis c’ is proportional to the square of the cosine of the same angle. Wa When the metallic mirror makes equal angles with the axes band c, b’ makes an angle of 45° with each; and then the light comports itself in the same manver on a glass pa- rallel to the axis 6’, or to the axis e’; it seems, in this case, to have resumed all the characters of direct light. Ray from the —-_If the ray reflected by the metallic mirror be dissected piu tia by means of a crystal of calcareous spar, in disposing its calcareous principal section parallel to the plane of reflection, the pro- oe portion of the intensities of the ray refracted extraordinarily and the ordinary ray is equal to the square of the tangent of the angle included between the two axes, 6, 6’. Light reflected Jf the light be made to undergo several reflections from pena metallic mirrors, before subjecting it to the action ofa second mirrors. transparent body, the phenomena are analogous to those I have mentioned. Ifthe axis ’ of the second ray be parallel to the axis } or ¢ of the first; if the axis 6” of the third be parallel to the axis b’ or c’ of the second; and so for the rest ; the property of the light already laid down will be in no respect altered: but if these axes be inclined to one another, it will be divided with respect-to the two cone secutive mirrors, according to the law I have mentioned., Reflectedlight If the surface of a polished opake substance, as black ate | marble, be made to turn round the axis c of the first re- flected ray, the reflected light will be seen to diminish to a certain point, at which it is null, and beyond which it begins to increase. --Ordinary phee All the ordinary phenomena of optics may be explained iceeel eters either on the hypothesis of Huyghens, who supposed them on the hypo. to be produced by the vibrations of an ethereal fluid; or thesis of Huy- agreeably to the opinion of Newton, who supposed them aera °F to be produced by the action of bodies on luminous parti~ cles, considered as themselves belonging to a substance obeying the attractive and repulsive powers, that serve to explain other physical phenomena. The laws respecting the course of rays in double refraction too may be explained but tho-e here.on either hypothesis. But the observations I have related mentioned not teconeilable | prove, that the phenomena of reflection are different at the tt a same PROPERTIES OF LIGHT. } 165 same angle of incidence, which cannot take place on the with that of hy bathesid of Huyghens: for we must necessarily conclude Huygnen from them, not only that light is a substance obedient to the forees that set other substances in action, but also that the form and arrangement of its particles have great influence on the phenomena. : If we transfer to the luminous particles the three rectan- All the pheno- gular axes, a, 6, c, to which the phenomena | have described eae are referrible ; and if we suppose, that, the axis.a being ¢le law. still in the direction of the ray, the axis bd or c, from the in- fluence of the repulsive powers, becomes perpendicular to the direction of these powers; then all the phenomena of total reflection, and: of partial reflection, and the most ex- traordinary circumstances of double refraction, become consequences of one another, and are deducible from this single law, namely, that; | 4 If we consider, in the transference of the luminous parti- The law. eles, their motion round their three principal axes, a, b, ¢; the quantity of particles, the axis 6 or c of which becomes _perpendicular to the direction, of the repulsive forces, will always be proportional to the square of the cosine of the angle, which these lines will have to describe round the axis a, to take this direction; and reciprocally, the quan- quantity of the particles, the axis 6 or ¢ of which will ap- proach the nearest possible to the direction of the repulsive forces, will be proportional to the square of the sine of the angle, which these lines will have to describe in their rota- tion round the axis a, to arrive at the plane, that Leino through this axis and the direction of the forces. In the case of double refraction, and when we consider the phenomena, that are exhibited by two contiguous crystals, _ we may express this law in the following manner, If we conceive a plane passing through the ordinary ray Law in the and the axis of the first crystal, and a second plane passing ¢4*¢ of double through the extraordinary ray and the axis of the second seieatin crystal, the quantity of light proceeding from the ordinary refraction of the first, and refracted ordinarily by the second, is proportional to the square of the cosine of the angle com- prised between the two planes abovementioned; and the : quantity 166 Reflection. Examples of theanplication of this law. Example 1. Example 2, PROPERTIES OF LIGHT. quantity of light refracted extraordinarily is proportional to the square of the sine of the same angle. if it be the ex traordinary ray of the first crystal on which we operate, we obtain a similar result, changing the word ordinary for ex- traordinary, and reciprocally, With regard to reflection, if we consider, for example, a ray reflected by one glass, with which it makes an angle of 35° 25, and falling on a second glass at the same angle, ta angle comprised between the two surfaces being in other respects arbitrary; we must conceive a plane perpendicular to the first glass, and another perpendicular to the second, passing through this reflected ray; and the quantity of hight reflected by the second glass will be proportional to the square of the cosine of the angle comprised between these two planes. I shall confine myself to a few examples of the application of this law. When a ray is reflected by the surface of a glass at ar angle of 54° 35’, we find, that all its particles are disposed in the same manner ; since, if we present perpendicularly to this ray a prism of crystallized calcareous spar, the axis of which isin the plane of reflection, all its particles will be refracted in a single ordinary ray, none being refracted ex- traordinarily. In this case the analogous axes of these par- ticles are all parallel, since they all comport themselves in the same manner. Let us call the axis of these particles, which are perpendicular to the plane of reflection, 6. All the particles, of which the axis ¢ was perpendicylar to that plane, have penetrated the transpareut body. If therefore we present to the particles reflected, and under the same angle, a second glass parallel to their axis c, they will be found similarly cireumstanced with those, which could not be reflected by the first; the ray therefore will penetrate this second glass entirely. In fact, experiment shows, that, ” under these circumstances, all the particles escape the forces of reflection. When we place two rhomboids of elgarcaue spar on one another, so that'their principal sections are parallel, a solar, yay parallel to these principal sections produces but two emergent / PROPERTIES OF LIGHT. 167 emergent rays; those which arise from the ordinary and ex- traordinary refraction of the first crystal being refracted each in a single ordinary or extraordinary ray by the second. In fact in this case it may be conceived, that, whether the axes of the crystals be parallel, or placed in opposite di- rections, every ray issuing from the first érystal parallel to its principal section is not divided by the second, for its movement takes place round the axis b or the axis ¢; and we have seen by the phenomena of reflection, that, when- ever the movement takes place round these axes, the ray is not altered; all the particles preserving the parallelism of their similar axes. ‘The rotation round the axis a being the only one, that changes the respective positions of the axes / of the particles of a given ray. When the incident ray makes any angle whatever with the Example 3. principa! sections, the rays that proceed from the double re- -fraction of the first crystal are divided into two by the second, so that we then obtain four emergent rays. In this circumstance however there are two different cases, in which the phenomena are very distinct: that in which the axes of the crystals are parallel, and that in which they are in op- posite directions. When the axes are parallel, a very vivid light must be employed, and the plane of incidence must be removed to a sensible distance from that of the principal sections, to be able to perceive the rays refracted ordinarily by one crystal and extraordinarily by the other. In fact, agreeably to the theory, the maximum of intensity of these ‘two rays is not the thirtieth part of that of the ray, which proceeds from the ordinary refraction of the two crystals; which has led those who have written on this subject to imagine, that, when the principal sections and the axes are parallel, the light comports itself in the same manner as in- the principal section, whatever be the direction of the inci- dent ray: but if we employ a vivid light, under suitable circumstances, observation accords perfectly with the the- ory. The phenomenon is much more evident, when the _ axes are in opposite directions. The extraordinary refraction is produced by a repulsive Extraordinary force, the action of which is cat hte to the square of féfraction, the 168 Double reflec. | tion. J General re- tarks, PROPERTIB5 OF LIGHT. the sine of the angle included between the axis of the crys- tal, and the principal axis, a, of the luminous particle. Al] the particles, of which the axis 6 is perpendicular to this force, are refracted ordinarily ; and all those, of which the axis ¢ is perpendicular to it, are refracted ordinarily. The particles refracted ordinarily, that escape the repulsive force, are in the same case with those, that escape reflection in the first class of facts 1 have described. : The phenomena of double reflection at the second sur- face of transparent crystals are analogous to those of the re- fraction in two crystals, the voile Pes) sections of which are parallel, and their axes in opposite «irections; with the ad- dition of this property common to all diaphanous bodies, that, when the reflecting face is parallel to the axis c of the luminous particles, the reflection at a determinate angle 1s null. Thus, without the knowledge of fie singular property of transparent substances, the most extraordinary part of the phenomena of double refraction would have remained inex- plicable. I shall not enter more largely into the particulars of the application of the theory J have brought forward, but shall content myself with saying, that it refers to one source a number of facts, which seemed to have no analogy to each etber, and the want of connexion in which rendered it almost impracticable to measure them. 4 I do not pretend to point oyt the cause of this general property of the repulsive powers that act on light; 1 merely» exhibit the means of connecting the phenomena with each other, of ascertaining them before hand by calculation, and of measuring them with accuracy: at the same time in ree ferring the figures of the luminous particles to three rectan- gular angles, as those of an octaedron would be, I antici pate nothing respecting the real. figure of these particles ; but I present the result as a consequence of the calculation, to which I have been led by the analysis of the- phenomena that, [ have observed, If, PRODUCTION OF SOUND IN VAPOUR. 169 Il. Experiments on the Production of Sound in Vapour: by Mr. Bior*. An infinite number of experiments have been made on Production the manner in which sound is produced and transmitted in ce peek different mediums. It has been shown, that it is neither in vapour not formed nor transmitted in a vacuum; and its transmission Yt examined. through solids and liquids has been examined: but no one, I believe, has yet thought of making these experiments in vapour. Such an inquiry however is ‘well calculated to ex- cite our curiosity ; for, setting out with the results that ex- No sound _ perience has made known with respect to the constitution i ames of the vapour that fills a given space, and applying to them pour, | the mathematical principles on which the laws of the minute vibrations of elastic fluids are usually founded, it is evident, that no sound should be produced in vapour, In fact it is shown, by the experiments of De Luo, Saus- Properties of sure, and Dalton, that the quantity of vapour of water, or of ““P°"" any other liquid, that is formed in a vacuum, depends only on the dimensions of that vacuum and the temperature : so that, if this vapour have an elasticity capable of sustaining the manometer at a certain height, and you compress it slowly, so as to oblige it to. occupy a smaller space, the elas- - ticity will not be increased ty this compression, as that of a permanent gas would be; but a portion of the vapour will - return to the liquid state, without any. variation of the. ma- nometer; and only so much willremain, as isadapted to the new limits, to which the vacuum is reduced, The reverse will happen, if the space. be enlarged instead of diminished : a new quantity of vapour will be formed to fill it, but with- out avy change in the elasticity, or in the manometer, These results have been completely established by the learned gentlemen I have mentioned, and we may easily convince ourselves of their accuracy. It is sufficient to in- troduce into a barometer a smal] quantity of any liquid; and to measure the height at which the mercury stands, _* Mém, de la Soc. d’Arcueil, vol. IJ, p. 94. Read to the Institute, October the 12th, 1807. after 176 PRODUCTION OF SGUND IN VAPOUR. after itis depressed by the elasticity of the vapour formed. If we then raise or lower the external level of the mercury, the interior column will rise or fall exactly as much im the tube; and thus, according as the space remaining at the top of the tube is diminished or increased, a part of the vate pour will be precipitated, or fresh vapour will be formed : but, the temperature shige the same, the elasticity will” not alter. Vibrationsof a Now let us suppose, that a sonorous body begins to vi- ea. body brate in such a medium ; each of its vibrations will diminish the space in one direction, and increase it in the opposite. Thus on one side there will be a small quantity of vapour re- duced to the liquid state, and on the other a small quantity of liguid will assume the state of vapour. These condensa- trons and dilatations will take place close to the sonorous body in the small extent of its vibrations, but will not be pro~ duced beyond this. Thus the motion will not be propa- gated through the rest of the fluid mass, and consequently the sound will not be transmitted. Ifwesuppose Let us next suppose, that the sonorous body, in com- em oe en pressing the vapour by its rapid vibrations, disengages from meee mechanically a certain quantity of heat. This supposi- tion is by no means improbable, for we know, that vapour gives out a great deal of heat in its condensation. The va- pour of water, fop example, according to the experiments of Watt, in returning to the liquid state gives out a quantity of heat, that is capable of raising the temperature’ of the, soundshovia water thus produced to 525° [977° F.]. If we take this cir- be producedin cumstance into consideration, the effects of the sonorous am body on vapour will no longer. be the same: the portions it compresses will preserve their elastic state, notwithstanding the diminution of the space, in consequence of the heat evolved, which instantly i increases their elasticity. On the contrary, in the portion dilated the diminution of tempera- ture, preventing a new evaporation, diminishes the elasti- city. The phenomena produced near the sonorous body . therefore ave of the same nature, as if the vapour became a permanent gas. There will be successive and momentary ‘ augmentations and diminutions of elasticity, the effect of which will be transmitted step by step throughout the whole of PRODUCTION OF SOUND IN VAPOUR. of the fluid mass, so as to permit sound to be produced and transmitted in it. Experiments onthe production of sound in vapour there- fore are calculated to decide the question, whether heat be really evolved in an aeriform medium by the effect of the vi- brations of sonorous bodies, as we see it in general extri- cated by any rapid compression. . Thus we may subject to decisive proof the ingenious idea of Mr. Laplace, by which he has found means of reconciling the mathematical theory of the transmission of sound iu air with the results of expe- rience, taking into account the heat evolved: for, if the effect he supposes do not take place, the vibrations of sono- rous bodies in vapour should not produce any sound; and, if they do produce sound, it can be only in consequence of the evolution of heat.. Induced by these motives, I made some experiments on the subject, which completely succeeded. 1 then repeated them in a more perfect manner, in the philosophical apart- ments at Arcueil, with my friend Amadeus Berthollet. Mr, Rerthollet, and Mr. Laplace were present at these experi~ ments, and themselves verified the facts | am going to relate, We took a glass globe that held 36 litres [near 38 wine quarts]. Its orifice was closed by a well made cock, so that avacuum might be made in it, which it preserved with great accuracy. To this cock another could be screwed; so that, by pouring a liquid into the space between them, and clos- ing both, this portion of liquid could be afterward intro- duced into the globe, without admitting any air from with- gut.. ‘The sonorous body was asmail bell, suspended within the globe by a slender string fastened. to the lower cock. A vacuum was first made within the apparatus to the greatest nicety, and eyen so as to exhaust a great part of the hygrometrical water, that might have existed in the globe, which however was very dry. ‘Then, holding the globe by the cock, we set the bell in motion, so as to satisfy ourselves, that the clapper struck very forcibly against the sides: yet, with all the attention we could bestow, even close to the globe itself no sound could be perceived; so that there was no perceptible sound in a vacuuin, agreeably to the experiments of Hawksbee, and all other philosophers, We 171 This may be brought to the test of experis ment. Sound was produced in vapour. Apparatus de- scribed. ae ain In a vacuum no sound. 172 PRODUCTION OF SOUND IN VAPOUR. Inaqueous va- We then introduced into the globe, in the way I have Pca described, a small quantity of water, part of which was con- verted into vapour. The sound immediately began to be perceptible, though the density of this vapour was ex- tremely small, the temperature being only 19° [66°2° F.]. proportional To increase it, an excess of water was admitted into the to its density. stobe, and it was placed in a stove at the temperature of 46° [114°8° F.]. The sound then became very perceptible: it could be heard without stooping down to the globe, and even.out of the stove through the door. Some water still remained in the globe, so there can be no doubt, that: the sound was produced and transmitted in the aqueous va- pour. When the globe was taken out of the stove, the temperae ture quickly fell: a great part of the vapour therefore, which had been raised in consequence of the temperature, was necessarily precipitated; and accordingly the sound appeared very evidently diminished. In vapour of Without any alteration in the apparatus, we introduced alcohol sound the same quantity of alcohol, as we had before of water. touder, a : : The specific gravity of this alcohol was 0°823. | The vapour from this mixture possessed of course greater density and elasticity than that of water at the same temperature; and accordingly the sound was much more perceptible: it was heard from one extremity to the other of the rooms that form the philosophical apartments at Arcueil, Sound therefore is produced and transmitted in the vapour of al- cohol. Experimentin As a last experiment we tried the vapour of ether. This vader particularly excited our curiosity, on account of its great elastic force and density, which are known to be very consi- derable; two circumstances, that must contribute to ine crease the intensity of the sound, We begun with drying the globe, because the moisture would have diminished the it evar tension of the ether; and then allowed the atmospheric air cound was to enter freely, till it was in equilibrio with the external _heardinate — pressure, which was 0°7613 [20°051 inch.]; and, carry- mospheric air, . ror ; ' ‘ing it into a long walk in the garden, we found, that the sound of the bell was sensible to the distance of 145 met, [158°5 yds]: beyond this it was so faint, that the perception DIRECT PASSAGE FROM THE STOMACH TO THE BLOOD. 173 perception of it wasnot sufficiently certain. The temperature was 17°75° [63°95° F.].. Having measured by this experiment the intensity of the sound produced im atmospheric air, we again made a vacuum in the globe, and introduced into ita sufficient quantity of sulphuric ether, to leave a surplus above what the temperature could convert into vapour. The specific gravity of this ether was 0°759. The elastic Fther intro- force of its vapour, measured by introducing it under a ba~ Sate of rometer freed from air, was 0°3549 met. [13°Y63 inches], at its vapour. the temperature of 17°75° [63°95° F.]. The globe being filled with this vapour, it was carried to the same place as in the preceding experiment; when we found, that the sound was perceptible to the distance of 131°5 met. [143°7 Distance at yards]. This conclusively proves in the most convincing ite ca ie manner, that sound is produced and transinitted in vapour, heard. as well as in a permanent gas. But we have proved, that This proves this can také place only from the effect of instantaneous va- Hip ey riations of temperature, occasioned by the vibrations. It of temperature . evidently follows therefore, that this cause really exists; eects he ac- and that, according to the judicious remark of Mr. Laplace, cording to the it becomes indispensable for us to pay attention to it in the een hee mathematical theory of the propagation. of sound; though Pie | we cannot directly verify it by the application of the ther- mometer, because this instrument can no more be affected by these successive and momentary variations of heat, than the barometer is by the momentary variations of elasticity, that take place in the production of sound, and of which every one notwithstanding acknowledges the existence. III. Experiments to prove, that Fluids pass directly from the Sto- mach to the Circulation of the Blood, and thence into the Cells of the Spleen, the Gall Bladder, and Urinary Blad- der, without going through the Thoracic Duct... By Eve- RARD Home, Esq. F. R. S*. Havine on a former occasion laid before the Society Fluids pess some experiments, to prove, that finids pass directly from ‘°™ the sto * Philos, Trans. for 1811, p. 163, the 174 DIRECT PASSAGE FROM THE STOMACH TO THE BLOOD. mach into the the cardiac portion of the stomach, so as to artrive at the cirs lood, ca culation of the blood without going through the thoracic duct, the only known channel by which liquids can arrive there; the present experiments are brought to confirm that opts But not nion; but in stating them, I wish'to correct an errour, I was through the spleen. Jed into, in beliexing that the spleen, was the en by which they are conveyed. | The passage At the time I made my former communications*, [ wad might be found by tying the Conscious, that the facts 1 had ascertained were only sufficient thoracic duct. to open a new field of i inquiry 5 ; but as I might never be able to make a farther progress in an investigation, beset with so many difficulties, I thought it right to put them on record, Since that time I have lost no opportunity of devising new / experiments to elucidate this subject ; and the circumstance of Mr. Brodie, the assistant of my philosophical as well as professional labours, having tied the thoracic duct in some experiments which will come before the Society, suggested ‘Sto me the idea, that, if the thoracic duct was tied, and pro- per experiments made, there could be no difficulty in ascer- taining whether there was any other channel between the stomach and the circulation of the blood. With this view I instituted the following experiment, . which was made on the 29th of September, 1810, by Mr. Brodie, assisted by Mr. William Brande’and Mr. Gateombe. I was unavoidably prevented from being present deiie the time of the experiment. Exp, 1, ona Hyxp.1. A ligature was passed round the thoracie duct of rabbit, a rabbit, just before it enters at the junction between the left jugular and subclavian veins: an ounce of strong infu- sion of rhubarb was then injected into the stomach. i three quarters of an hour some urine was voided, in which rhu- barb was distinctly detected, by the addition of potash. An hour and a quarter after the injection of the rhubarb the ani- mal was killed: a dram and half of urine was found in the bladder highly tinged with rhubarb, and the usual alteration of colour took place on the addition of potash. The coats of the thoracic duct had given way opposite the middle dor- sal vertebra, and nearly an ounce of chyle was found effused into the cavity of the thorax, beside a considerable quantity * See Journ. vol, XX, p. 374, aud XXI, 108, \ iD 7. DIRECT PASSAGE FROM THE STOMACH TO THE BLOOD. am ire. in the cellular membrane of the posterior mediastinum. Above the ruptured part the thoracic duct was entire, much distended with chyle; and on tracing it upwards, the termi- nation of the duct in the vein was found to be completely secured by the ligature. The lacteal and lymphatic vessels had given way in several parts of the abdomen, and chyle . and lymph were extravasated underneath the peritoneum. In this and the following experiments the infusion of rhu- Infusion of barb was employed in preference to the prussiate of potash, ny eal in consequence of its having been found in those I formerly sensible test. _ made, that one drop of tincture of rhubarb could be de- tected in half an ounce of serum, and nothing less than a quarter of 2 grain of prussiate of potash in the same quan- tity could be made to strike a blue colour when the test was added. - Exp. 2. The experiment was repeated upon a dog. In Exp. 2,.0n a this [ was assisted by Mr. Brodie, Mr. William Brande, Mr. 4°8 Clift, and Mr. Gatcombe. After the thoracic duct had been secured, two ounces of strong infusion of rhubarb were in- ~ jected into the stomach, and in an hour the dog was killed. The urine in the bladder, on the addition of potash, became deeply tinged with rhubarb. The bile in the gall bladder, by a similar test, was found to contain rhubarb. The lacteal vessels in several parts of the mesentery had burst, and chyle was extravasated into the cellular membrane; the tho- racic duct had given way in the lower part of the posterior mediastinum, and chyle was extravasated. Above the rup= tured part the thoracic duct was much distended with chyle; it was readily traced to the ligature, by which it was com- pletely secured. ‘These experiments apieared to establish the fact, that the The chine thoracic duct was not the channel through which the infu- able rs sion of rhubarb was conveyed to the circulation of the blood, => * and it now became easy to ascertain, whether it passed through the spleen, by extirpating that organ, and repeating the last experiment. On the 2ist of October, 1810, the following experiment was made with the assistance of Mr. Brodie, Mr. Clift, Mr. Gatcombe, and Mr, Money. : Exp. 3. . 176 ' DIRECT PASSAGE FROM THE STOMACH TO THE BLOOD. Exp: 8, ona Exp. 3. The thoracic duct near its termination was se- rk syeeuen cured in a dog, whose spleen had been removed four days and the spleen before, and three ounces of infusion of rhubarb were injected extirpated. into the stomach. In an hour and half the dog was killed, and the urine was found strongly impregnated with rhubarb; and on examination, the thoracic duct was tound to be com- pletely secured by the ligature. Several of the lacteals had burst, but the duct itself had not given way; it was greatly distended with chyle and lymph. The ooh not By this experiment it was completely ascertained, that the me passages spleen is not the channel through which the infusion of rhu- barb is conveyed into the circulation of the blood, as [ had, been led to believe, and therefore the rhubarb, in my former. experiments detected in the spleen, must have been depo- sited in the same manner as in the urine, and in the bile. ' Inthe nextex- ‘The detection of this errour made me more anxious to ean tinh avoid being misled respecting the thoracic duct; and there- the thoracic fore, although there was little probability that the infusion eee bs , of rhubarb could have passed into the lymphatic vessels, wis ly mphatic which open into the blood vessels of the right side of the trunk of the neck, I thought it right, before 1 proceeded farther, to re- ee ne peat the experiment, securing the termination of the thora- cic duct on the left side, and the lymphatic trunk of the right side, where it empties itself into the angle between the jugular and subclavian vein. This was done on the 28th of. October, 1810, with the assistance of the same persons as in the last experiment. _Exp.4,ons Erp. 4. The thoracic duct of a dog was tied, as in the dog. former experiment; in doing it the duct was wounded, and about a dram of chyle flowed out; the lymphatic trunk of the right side was then secured, After this, three ounces of © infusion of rhubarb were injected into the stomach, and in -an hour the dog was killed. The urine and the bile were ‘found distinctly impregnated with rhubarb. On opening the thorax, some absorbent vessels, distended with lymph, were seen on the right side of the spine, eitering an absorb- ent gland on the second dorsal vertebra, and the vasa effe- rentia from the gland were seen uniting with other absorbent vessels, and extending towards the right shoulder, where big, . . they DIRECT PASSAGE FROM THE STOMACH TO THE BLOOD. 177 they formed a common trunk with the absorbents from the neck and axilla; this trunk was found included in the liga- ture. The. thoracic duct was moderately distended with a mixture of chyle and lymph; in tracing it upwards, an Opening was seen in it immediately below the ligature, through which the contents readily passed out when prese sure was made on the duct: above this opening the duct was completely secured by the ligature. Nearly a dram of the fluid contained in the thoracic duct. was collected and tested by potash, but there did not appear to be any im- "pregnation of rhubarb. Exp. 5. The last experiment was repeated on another Exp. 5, ona dog, on the 2ist of January, 1811, with the assistance of 9°: Mr. Brodie, Mr. W> Brande, Mr. Clift, and Mr. Gatcombe. The dog was killed an hour after the thordcic duct and lym- phatic trunk had been secured, and the infusion of rhubarb had been injected into the stomach. In tying the right lymphatic trunk, a lymphatic vessel Yom the thorax going to join it was wounded, from which chyle flowed out in considerable quantity during the whole time of the’ experiment; a short time before the dog was killed some of it was collected, but on testing it with potash no. rhubarb was detected i init. “The urine was found impregnated with ae age as was also, the bile from the gall bladder 5. but both in a less de gree than i in the last experiment. The lacteal vessels and mesenteric glands were much distended with chyle; and on cutting | into the glands chyle flowed eut in considerable quantity, Some of. this was collected and tested with pote ay but showed no evidence of rhubarb being contained in “The thoracic duct was much distended ; it was traced 3 the ligature, and was found to be completely secured. _ Lymphatic vessels from the right side of the posterior me- diastinum were seen extending towards the ligature, that had been tied o on that side; they were nearly empty; -and the trunk formed by the junction of these with the lympha- tic vessels, from the right axilla, and from the right side of the neck, was seen distinctly included in the ligature. | While Mr. Brodie was tracing the thoracic duct, Mf. Some rhubarb William Brande was making an infusion of the spleen, and fo#nd in the Williar leen, ~ Voi. XXX.—Nov. 1811. le aa showed oe 178 DIRECT PASSAGE FROM THE STOMACH TO TAE BILOOD. but none per- showed me a section of it, in which the cells were larger, and Thay in the snore distinct, than I had ever seen them in a dog. There was a slight tinge of rhubarb in the infusion from the spleen. A similar infusion was made of the liver; but the quantity of blood contained in it being much greater than in the spleen, the appearance was not sufficiently distinct to decide whether it contained rhubarb or not. ‘These experiments appear completely to establish the fact, that the rhubarb did not pass through the thoracic duct, and therefore must have got into the circulation of the blood by some other channel. They likewise completely overturn the opinion I had adopted of the spleen being the medium by which the rhubarb had been conveyed, and show that the épleen w ‘ane swers some other purposes in the animal economy. The rhubarb The rhubarb found in the spleen does not arrive there be- probably de- fore it enters the circulation, it is therefore most probably posited i in the spleen in the afterwards deposited in the cells in the form of a secretion. pam ase That the rhubarb goes into the circulation is proved by my former experiments, in which it was detected in the splenic veins .. The prussiate-of potash is hardly to be discovered in the blood of a living animal, since the proportion which strikes a blue colour on the addition of solution of iron, is — greater than the circulating fluids can be expected to contain at any one time, as it goes off by the secretions nearly as fast as it is received into the blood vessels. In a moderately sized ass more than two drams must be dissolved in the blood before its presence there can be detected. That the fluid contained in the cells of the spleen is se- creted there, is rendered highly probable, since it is most - abundant while the digestive organs are employed, and scarcely at all met with when the animal has been some time without food. The great objection to this opinion is, there The lympha- being no excretory duct but the lymphatic vessels of’ the: tics of the spleen proba- Spleen; these however are both larger and more numérous bly form its ‘ Scexcrtaip duct, than in any other | organ ; they are found in the ass to form one common trunk, which opens into a large gland on the side of the thoracic duct, just above the receptaculum chyli; and when the quicksilver is made to pass throu: gh the branches of this. gland, there is a trunk equally largre on the ‘ opposite side, which makes. an n angle, and then texminates MECHANISM OF LEAF*STALKS. 179 in the thoracic duct. This fact I ascertained at the Veteri- nary College, assisted by the deputy professor Mr. Sewell, and Mr. Clift. These lymphatic vessels are equally large conveying its as the excretory ducts of any other glands, and therefore suf- secretion into ficient to carry off the secretion formed in the cells of the Cesnnerines spleen ;'and where a secretion is to be carried into the tho- racic duct, it would be a deviation from the general plan of the animal economy, were any but lymphatic vessels em- ployed for this purpose. It is a strong circumstance in favour of the secretion be- ing so conveyed, that in the last experiment, the lacteals and cells of the spleen ‘were unusually turgid, being placed une der similar circumstances, the thoracic duct being so full as not to receive their contents. The purposes that are answered by such a secretion from the spleen into the thoracic duct cannot at present be ascer- tained, : IV. of the sa Powers in the Leaf Stalks of various Plants. : Ina tation eens Mrs. AcnEs InpeTson. To Mr. NICHOLSON. Iw pointing out what appears to me to be the Ssentetons Mechanical of mechanism in the hairs of plants I have by no means ex- eg hausted the subject, but rather begun it, The mechanism of botany, thongh not yet familiatized to tit ideas, ten6k the less beautiful, or true. As I have introduced jit, so T shall continue to exhibit specimens of it, showing, that there i is not a part of a flower, leaf, or stem, that is not ma naged by ‘mechanical means. This' is admirably depicted depicted in the in the leaf stalk, which I shall make the subject of the !safstalk- present letter; as Mr. Knight, in his view of it, has given only one sort of peduncle, without desctibing the increased N @ size 180 Mechanism increasing from the firs to the mimosas- Most plants have gather- ers, gt yaa MECHANISM OF .LEAF-STALEKS. size of the part/that joins.the stem; which at/one. time. of the year.is but little larger, and shows the gathere* but, poorly, There appears a regular gradation of mechanism in this part of all plants, from those which, having the, leaves per- _fectly sessile, are fastened i in such a manner to the stem, ae "to. be absolutely incapable of turning, or moving in any manner, to those. plants, the leaves of which move with a touch, and the mechanism of which I have before described in the mimosa sensitivayt. Thavealready with indefatigable pains traced ke grada- tion through 130 genera of plants, differing as much as. possible, selecting in each a few to illustrate this truth, and in which the mechanism increases gradually from the firs, the leaves of which move not, and have therefore no spiral wire, to the mimosa, which has 1 it knotted and turned over balls. No The first ‘degree of motion in the peduneles 18 caused hy the simple spiral wires in their cases passing into every di- minutive vessel in the leaf. The motion is then as simple as the means, and the leaf is ‘merely drawn nearer, or falls farther from the stalk: but when the spiral wire is doubled or crossed, there appears some diversity of motion, by the leaf not ouly advancing and retiring, but being ; able to be drawn on one side. The next gradation j is shown by the increase of the peduncle néxt'the stalk, and this merease I have ventured to call the gatherer, because it contracts and dilates to favour the spiral wire.’ Whe this is found dou- ble, that is, adjoining the leaf, as well as the stem; the motion is very greatly increased, since each of them moves through the third of a circle, as, [ shall . presently show. ‘When there appears a ball within the gatherer, the leaf, “generally. proves to be one of those compound leaves, which, close,as the evening advances. _ The gradation from this to the.mimosa, or those leaves which move with a touch, seems, effected by more balls, and by the spiral wire being knotted in.a,more complicated manner. It would have been curious _ sto plow ‘one of each of these specimens, which I have drawn togi - ot + The name by; which I distingyish the increased part of the pefuncls. ’ it See Journal, vol, XXIyv, p. 160, en's » for MECHANISM @F LEAF-STALKS, for myself; but they would take up too much room, Sir, in your Journal: I shall therefore give only a specimen of what I mean by a by Wap and a representation of the leafs stalk dissected. Lav 181 No person can have examined a tree with attention, with- The beautiful out observing the beautiful arrangement of .its leaves ; exquisite manner in which they are prevented from obstruct+~ ing the licht, or keeping the air from each other, and the various curious contrivances (especially with large leaves) manifested in raising or depressing them, so as to prevent their throwmg too deep a shade on each other, and on the pea» leaves, those that are beneath them. It is to the gatherers alone — they are indebted for this, to the power the two ends, of the peduncle have of turning through the third of a circle, that they are able to place themselves in this manner, and arrange their leaves. in such beautiful order, so conducive to their benefit and future health. The peduncle may generally be divided into three parts, and, if it has any mechanisin to manage, which it ~is sel- dom without, it is always found in two of these parts, that which joins the peduncle to the stem, and that which unites the leaf to the peduncle. Pl. V, fig. 1, is a drawing of the peduncle of the liburnum or cytisus. AB are the two ‘ga- therers; and C Dare the same extremely magnified, and dissected ; it is easy to see, that the spiral wire being much contracted may draw these into various figures, according as it is tight or loose within the gatherers, as it is at ee, and may turn them three parts of a circle; and thus make the leaf or leaf-stalk measure a very extensive circumference; and by this means accommodating its neighbour, and placing itself in the most eligible situation, not only for its leaf, but for the buds which are trusted to its care, and generally in the’ axilla of its peduncle. The gatherers at both ends appear, when much contracted, like a screw at the exte- rior, and sometimes they are ‘so bent as to be doubled, but at “another time you will hardly be able to see that they Explanation of the plate. do'gather, so various-is their figure. I shail now show a Description ef specimen of ‘a leaf-stalk, which comes nearer in gradation to the sensitive platy oné of the medicagoes, differing little _ from “the trifoliums, and many of the diadelpbian. plants. Fon Fig. the medicago polymorpha. 182 MECHANISM OF LEAFeSTALKS. Fig. 2 is the plant: B Bis the upper gatherer, but. it has instead of the under one a stipula, which seems by some means (which I have not yet been able to comprehend) to serve instead. All the trifoliums and numbersof the diadel- phian plants, have it thus. Fig. 3 shows this part dissected and explained. I have never found the balls zz except in the medicagoes, and not in all of these. There is not any thing more-curious than the substance of which the balls Formation of are formed, It strongly resembles the matter of the bark the balls, without the inner bark vessels, is extremely watery, is the first part that decays, and appears to serve no other purpose, than to fix the string in its place. It is curious, that at ¢, where the knot comes, there is a fastening which passes en» tirely through the plant. The gatherers mand m at the Form ofthe side have no balls. There is another kind of a gatherer of everlasting = @ yery curious form, which is found in the papilionaceous pea. 7 ; om tribe. It has but one ball; but the same matter, being collected into a thick lump, is folded into creases (see fig. 4, and the dissection fig, 5, pq ); and have.a ball in a semi- circular socket ; it turns it to one crease, or the other, by means of the spiral wire. Fig. 5 better displays this, heing a side view, and showing how it turns to the right or left, by taking the upper or lower crease, which of course turns the leaves nearly a whole circle, Fig. 6 shows the string A wstdnge rol when drawn tight in the gatherer, This will serve to prove take. the thorough mistake of those physiologists, who pretend, that the different parts of a plant may be changed for each other, and make a peduucle or Jeaf take root. Nature does not execute her work in this careless manner, each part has its separate mechanism, than can perform only the part ase signed. If a flower bud. is concealed in the peduncle, it may by accident grow,. since the lower part of the gatherer, which joins the stem, is full of flower buds: but then it is these that grow, and not the leaf-stalk ; nor can there be any thing more different, than the peduncle stem, . I shall give no farther examples this time, as what I have already said will be, I hope, suflicient to make what I have drawn understood, and to give some idea. of the mechanical management of this part of most plants; accounting for the beautiful arrangement of theleayes of trees; and proving, ¥ net DECOMPOSITION OF WATER BY GALYANISM. 183 not only that the spiral wire is the cause of motion in plants, but that the management of a plant is wholly mechanical. | I an, Sir, Your obliged Servant, AGNES IBBETSON. I shall in my next give some account of the form of those sessile leaves, which belong to annuals, and those which are of the order pentandria digynia, as there are many curious particulars, which belong to both, and which I have not at present time to detail. a a ESE SE Vv. On the Decomposition of Water in two or more separate Ves- sels. Ina Letter from Apam ANDERSON, Esq. To W. NICHOLSON, Esq. SIR, ’ ‘Tuoucu the detection of erroneous statements in mat- Detections of ‘ters of science is certainly a more humble task than the dige €fours in sci- , 2 ; ence importe ‘covery or generalizement of facts, it must still be regarded ant, as contributing, at least in some degree, to the progress of true knowledge, in so far as erroneous views have a tendency, not only to supersede experimental investigation, but to waste the energies of the mind in attempts to explain a state of things, which has no real existence in nature. I have been led to this remark, by reflecting on the difficulty, Difficulty in which chemists have hitherto experienced, to explain the ©*plaining the ‘transmission of the elements of water, during the decom- Eimeteen of position of that fluid by galvanism, when a metallic wire water in sepa. “forms part of the circuit, and the experiment is perfermed sind on in separate receivers. ~ Lhave ascertained, beyond the possibility of doubt, that Oxigen and hidrogen not the transmission of oxigen and hidrogen in Opposite cur- beahemieee ‘rents through the connecting wire is, contrary to the as- thiough the wih wire in oppo sertion of Ritter, pineal fallacions ss the pipppsltion Mesias ® eared, ‘Ato edition, val 1V, Pp. 512, , 0 ¢ 184 DECOMPOSITION OF WATER BY GALVANISM. of such a transmission must have arisen, either from an inac= curate mode of performing the experiment, or from a hasty and unwarranted generalizement of the repulsions and at- tractions supposed to be exerted at the opposite poles of the galvanic battery. ; Decomposi- Most of your readers are aware, that, when gold wires tion of water proceeding from each extremity of a moderately powerful ay piper hae galvanic battery, in a state of action, are introduced under a receiver filled with water, aud inverted over a b:sin con- taining the same fluid, as at-Pl. VI, fig. 1. the wire P being connected with the zine side, and the wiie N with the ne- gative side, a decomposition of the water immediately en- Sadan ane year 2s oxigen is eyolved at p, and hidrogen atm. The de- sel with sepa gomposition even goes on, when the wires are inserted in rate FeCsiVers. senarate receivers, fig. 2; attended with this remarkable circumstance, that oxigen alone is found in one receiver, and hidrogen alone in the other. As we are forced in the present state of our knowledge, to believe, that a decom- position of the water takes place at the extremity of each Supposed re- wire, we most also admit, that the oxigen evolved at n i8 pulsionand expelled by the negative, and attracted by the positive attraction of the oxigen and Polut, while the hidrogen evolved at ‘p is repelled by the hidrogen, positive, and attracted by the negative point; so» that, during the decomposition contrary currents of oxigen and sufficientto bidrogen are proceeding along the dotted line nap. Nay, prevent their we must even admit, that the force of these attractions and eps a repulsions is sufficiently powerful, not only to separate the elements of water from a state of combination, but also to overcome the mechanical tendency so ascend, through the water, which these elements possess in their gaseous con- dition. - il Similar pheno- All this’ may be aanneida without ‘intl difficultys but mena sai! io the fact stated by Ritteris by no means so easily explained ; take place « ea ‘ when the wa- and indeed it has never been yet accounted for, without ,ter isin sepae having recourse to the most improbable ‘supposions. «This fate vespele. philosopher affirins, that when the receivers ab, ed; fig. 3, filled with water, and inverted over separate vessels, A B, CD, are connected by a gold wire, pn, if the wires P, N, from the opposite extremities of the battery be immersed jntothe water contained in the vessels A B, C D, a decom- position DECOMPOSITION OF WATER BY GALVANISM. 185 “position of the water in the receivers takes place, accompa- ‘med by the same result as before, oxigen alone being found in one of the receivers, viz. ab, and hidrogen alone in the other,c d. Hence he concluded, that as a decom posi- The gasses tion of the water must have taken place at each extremity foe ae of the connecting wire, the oxigen must have passed through the wires. that wire from n to p, where it was evolved, and the hidro- gen in the contrary direction from p to z. This explanation, so much at variance with all our notions The improba= of the impermeability of dense metallic substances by eed ea gaseous bodies, seems to have been reluctantly adopted doubt of the by the greater number of chemists; while to a few it iigameta has appeared so inadmissible, that, rather than’ em- — brace it, they have been ied to doubt the truth of the opinions commonly received with respect to the compound nature of water. No person, however$*#ppears to have “suspected the accuracy of Ritter’s statéient, or even ‘to have ‘repeated his experiments with any degree of care. ‘The experiments, which I shall now describe, and which, I trast, will be deemed worthy of a place in your Journal, prove, in the most satisfactory manner, that the transmission of the elements of water in opposite currents through the connecting wire is altogether deceptive, and that the opinion of such a transmission taking place is fuunded on the want of a due attention to all the circumstances of the experi- ment. “When I first repeated the experiment of Ritter, the re- The experi- sult, 1 confess, appeared very singular; I saw no way of ex- Ment repeat- /plaining why the oxigen and hidrogen were found separately, — without ‘adopting the opinion of Ritter, or denying that water was a compound of these two elementary subsianccs, - ‘At length, however by reflecting more maturely on the The pheno- ‘subject, “T began to suspect, that there might be a ‘positive a an and a negative point in each receiver taken in conjunction pesitive and with the corresponding cu p. over which it was suspended : that ing oitee ik the extremity of the wire P, fig. 3, connected with the zine each receiver. side of the battery, being positive, and the water acting as a conductor.to the galvanic energy, the positive state would be conveyed through the water to the cenuecting wire 2p, go that the extremity p would also become positive ; while, - for ? 186 ¥xpenments to prove this. DECOMPOSITION OF WATER BY GALVANISM. for a similar reason, the opposite extremity n would become negative: that, consequently, as there was a positive and a negative point in the water connected with each receiver, it was obvious, that the decomposition would be effected by mutual attractions and repulsions subsisting between the elements of water, and the two contiguous points of the interrupted circuit, which were thus immersed in the same finid ; in short, that Ritter had been misled by overlooking the decompositions, which, I conceived, took place at the extremities p and x of the wires connected with the battery, I accordingly adopted a new arrangement, as at fig. 4, I caused the wires proceeding from the battery to pass through the-upper part of the receivers (which were hermetically sealed) and then placed the receivers over the connecting wire pn, supported: on a stand, and passing through the two glass capsules. A B. By this disposition of the wires connected with,.the battery, I was sure of collecting | any gasses which might be evolved at their extremities. The result answered my expectation. I now obtained, not ox- igen in the one receiver, and hidrogen in the other, but these two substances in each, in the exact proportion, in which thev combine together to form water: for on passing the _ electric spark through the gasses collected in each receiver, separately, a detonation took place, the gasses entirely dis- appeared, and water was regenerated. The nature of the decomposition, which happened in each receiver, was ob- vious: the wire P, proceeding from the zinc side of the battery, being positive at the extremity p, and the water in the receiver operating as a conductor, the positively electric state was transmitted through the water to m, and then along the connecting wire np to p, which by this means became also positive; in like manner, the wire n connected with the copper side of the battery, being negativeat the ex- tremity n, and the negatively electric state being transmitted through the water to p, and then along the connecting wite pn to the extremity , this extremity became negative. There being thus a positive and a negative point in each receiver, the decompositions which took place differed in no respect from those which happen when the arrangement yepresented at fig. 1 is employed, It DECOMPOSITION OF WATER BY GALVANISM. 187 It now occurred to me, that every interruption of the Every inter- circuit would afford a positive and a negative point ; and ‘¥Ption of the circuit affords that a series of decompositions might be procured, by fol- a positive and lowing out the same arrangements in a succession of re- "¢éative point. ceivers. I therefore constructed an apparatus: first with four interruptions in the circuit, and afterwards another with six, fig. 5; and in both cases, I obtained in each receiver, the elements of water in the proper proportions, in which they combine to form this fluid. The positive and negative points are marked in order. Though. these experiments were perfectly decisive - sith An experi- regard to the effect. produced by the connecting wire, and Maney as sufficiently calculated to unfold the real nature of the de- peated. composition, to which it was subservient, 1 could. not rest satisfied, till I had repeated an experiment, which Mr. Murray seems to adduce in confirmation of the imaginary transmission.. I say, seems to adduce, for the experiment is stated with so little precision (considering the usual ac- curacy of this excellent chemist), that it is difficult to disco- ver the real object, for which it is brought forward. After mentioning the experiment of Ritter, and adopting the - conclusion which he deduced from it,.he adds—*‘ I have Decomposi- §* found, too, that if a portion of quicksilver be interposed page Bias _** between two portions of water, (which can be easily done vessels with «* by filling the bent part of a siphon with .quicksilver, and eae ** putting: water into each leg) on placing wires connected $; with.a galvanic trough in the separate portions of water, **.gas arises from each wire*’’, In orderto repeat theexpe- rimentof Mr, Murray, I constructed an apparatus, such as I shave represented at fig.6. pabn represents the bent siphon, . the opposite ends being introduced through two glass capsules, A,B, to which they were hermetically sealed at the bottom, d,e. Having filled the capsules and the bent siphon with water, 1 inverted over the extremities of ‘the siphon two small receivers filled with water, through the ends of which Lhad_ previously passed the gold wires Nn, P p, and :to which they were sealed, by .melting the glass. I then connected dha wire. ar n- with the upper-side of the. creo and. —“~ ® Sinise s Cheeta vole J, ip, 558, wos with 188 DECOMPOSITION OF WATER BY GALVANISM. with the zine side, and csvrhandi gas was disengaged at Oxigen inone their respective extremities'n and p. On examihing the eee Ape a gasses obtained in the two receivers, the gas in the receiver ogen in the é other,when connected with the negative side of the battery was hidro- bales was'gen, and that in the receiver connected with the positive side, oxigen. This arrangement did’ not differ essentially from that represented at fig. 2; and the reason why the gasses are found separate is equally applicable to both. but when mer. 1 then removed the water out of the bent siphon, and eury was inter- supplied its place with mercury, confidently expecting, that posed, the mercury (making allowance for its oxidable property) would operate precisely as the connecting wire in the are rangement represented at fig. 4... Accordingly, on connect- ing the wires N and P with the opposite sides of tne battery, this wasoxided In a few seconds I perceived an oxidation of the mercury in one re- taking place at the point p of the bent siphon, which, as the ceiver, and left. : é : pure hidrogen, Wire P p was connected with the zinc side of the battery, while the other was a positive point. Gas was copiously disengaged at the ie cig opposite extremity of the siphon, as well as from the points exigen and hi- » and p of the connecting wires. After allowing the decom- ee position to go on during some minutes, I examined the - gasses in the two receivers. The gas in the receiver over the capsule B exploded by the electric spark, and disappeared completely, while no effect whatever was produced: by pass- ing a succession of electric sparks through the gas in the re« ceiver over A. I therefore introduced into this receiver as much oxigen, by measure, as was equal to half the bulk of the gas which it already contained, and which I had no doubt was pure hidrogen: I then passed the electric spark through the mixture, when an explosion took Me and both gasses completely disappeared. Ritter there. | This experiment, therefore, so far from supporting the fore misled. opinion of Ritter, shows, that he must have been misled” by a partial view of the circumstanees attending the decompoe sitions, while it affords an additional illustration of what I have already stated with respect to aseries of alternately positive and negative points at every. soaring of the cite cuit. v7. Ke HW ed Another expe- Pursuing still fatthiee the idea of this alistpercdioes of the iment with an electric states, [-ceniented to aglass rad/a succession of small NEW VARIETIES OF CARBONATE OF LIME. 189 small bits. of gold | wire, and having interposed them in that interrupted state, between, the extremities p a n, fig. 1, of the two circuit. wires connected with the positive and negative sides of the battery, I observed, with pleasure, a considerable disen- gagement.of gas taking place, at the same time, from each extremity of all the eehonteeted wires, which formed the galvanic circuit. | Having thus pointed out the circumstances aie ied The principle Ritter and his followers, and established, beyond all doubt, of the decum- the important fact of a positive and a negative point at every age bi iis interruption of the circuit, it is almost unnecessary to ob- in all cases, serve, that the decompositions, which happen by employing the arrangement first suggested by that philosopher, admit. of being explained on the same principles as the decon:po- sition effected by introducing under the same receiver a positive and a negative point, proceeding immediately frona ‘the, galyanic battery. tie “Ae Htawcrgety LPs Sir, your most obedient servant, rr it ADAM AN DERSON, "Perth Academy, ny 1 eh 23, 1811. eemosned Sc? OT wR (oll Se v : , : ' . : ; VI. Sete Titi @ a+ : tw L rity Description of venation new Varieties of carbonated Lime: by Yosser ach: “Mr. Havy*. | ae a + akaoi sit ta, of which the bbjecti is to iviedeiets Two laws of .the varieties of a crystallization having a rhomboid for its’ aorateg primitive form, are susceptible of two solutions, which leadsnucleus, deter ' tothe sauie figure by different laws ‘of decrement.) Me- po eeie chanical division, by making known the position of the faces | of the nucleus with respect to those of the secondary crys- tal, shows on which of these two laws the figure of a given crystal depends, »In the course of a long'time I bad very sometimes na- seldom met with the two solutions at once in the same sys- tue follows tem of crystallization; but instances of this kind have gigs OD mére numerous among the recent observations I have made é Be r > ~ “ * Journal des Mines, vol. XXIII, p. 49. s on ry nQ 190 Trihexaedral «arbonate ef lime, NEW VARIETIES OF CARBONATE OF LIME. on the varieties of carbonate of lime, of which I have now 93 in my collection. 1 shall describe some of these, which realize the possibility of this double employ of the same figure with two different structures. The trihexaedral carbonated lime, Pl. VI, fig. 7*, a spe cimen of which was presented me by Mr. Hericart de Thury, exhibits itself in the form of a regular hexaedral prism C C’, terminated by two right hexaedral pyramids P «... Three faces, P, of each pyramid, taken alternately, are parallel to. those of the nucleus. The other three, de- ~ signated bys, which arise from a decrement by two rows in» Ambiguous ‘carbonate of lime. Common me tastatie dode- Saedron. height on the lower angles of the nucleus, are inclined to the adjacent sides at the same angle as the preceding, namely 135°; so that the secondary rhomboid, which the union of these faces would produce if they existed alone, would be similar tothe nucleus. : This result, which I have demonstrated in the geometrical part of my treatise, may be considered as the limit of all those, to which the double solutions I have spoken of lead yl because it is that, in which, one of the two quantities ex- pressing the decrement becoming 0, the solid answering to this term is the nucleus itself. > In the ambiguous carbonated lime, fig. 10, the dodecaee dron $ $, which in this variety is combined with the inverse rhomboid 7 f, and the sides C C’ of the regular hexaedral prism, is similar to the metastatic dodecaedron, vulgarly dogtooth spar; but it depends on a different law of decre- ment, of the kind of those I have called intermediate. This result sh ocbeg a certain explanation to be well under~ stood. . In the common metastatic dodecaédron, fig. 11, the least saliant edges answer to the faces of the nucleus, while the most saliant are turned toward its edges. I had inquired, when I wrote the geometrical part of my treatise, whethér there were not a law of decrement capable of producing a@ “secondary crystal similar to the metastatic, so that the edges turned toward the faces of the nucleus should be, contrary to it, the most saliant; and I found, that this result would take place from the intermediate decrement *E *B 'D», ® Fig. 8 represents the primitive form, Ona \ NEW VARIETIES OF CARBONATE OF LIME. 191i On the other hand, the common inverse rhomboid has its Common in- faces turned toward the superior edges of the nucleus: and, /°" signs! having also examined what law would give the same rhom- boid, with its faces answering to these of the Demet I was led by calculation to the result expressed by e. Let us suppose, that the common inverse rhomboid is Combination combined in one figure with the common metastatic dode- ° calbaaenes caedron; it is evident, that its faces would answer to the mest saliant edges of this dodecaedron: but in the variety Structure of before us, on the contrary, they answer to the least saliant ee al edges. Now there are two different cases, in which this may take place: one is that in which the metastatic would result from the law D, and the inverse rhomboid from the law e the other, that in which the metastatic would be produced by the intermediate decrement, and the rhomboid by the _ decrement E* E*. Mechanical division removes all ambi- guity by proving, that the second is the case. The faces of the two solids combine, as I have said, with the sides of the hexaedral prism, from which we can derive no indication in favour of one structure, or of the other. The stencnome carbonated lime, fig. 9, differs from that Stenonome which I have described in my treatise under the name of pling on a subtractive by the addition of the facetse and w. The for- mer afford a fresh example of the law of decrement, which tends to produce'a rhomboid similar to the nucleus. The . faces. exhibit a particular case, the possibility of which I had proved; namely that in which the decrement on B, fig. 8, taking 5 place by two rows, would produce a dodecaedron, all the trianglesof which, instead of being scalene asin the . other cases, would become isosceles; that i is to say, the do- decaedron would be composed of two right pyramids united base to base. _ In fact we should havea ‘dadevacirdn of this. kind. by prolonging the faces in question. till all the others... had disappeared, he angle of 151° 42”, which measures the respective Spopbrtions incidences of the faces of this dodecaedron, is exactly dou- igs me ble the angle of smallest incidence of the faces of the nu- is cleus, 7s 31 21”. These proportions between the angles of 1g2 _ « ON RADIANT HEAT, &e, of the sii form and those of the secondary erated are not unfrequent in the varieties of carbonated lime. Crystals for- _ From these examples it is seen, that results, which I had _ *UPPOS civen as merely hypothetical, appear as descriptions by an- ticipation of so many products of crystallization, which ex- isted in the bosom of the Eatth without our knowledge. | } aid . : i Vil. Extract of a Leiter from Dr: Francis DEvarocne. to F. Bercer, Esq.;0n Radiant Heat-and other shit rig A aPSeAE Pa by the latter Gentleman. 36 Panis,» ee the 17th, hae mt rusnomen of [yy my nt two letters, I mentignad to. you an inguiry | into. the phenomena of radiant caloric, which I commenced Jast spring, aud of which the principal results are the following. . Radiant caloric, almost entirely, divested of the faculty of traversing glass, when, the substance that emits it is at less than 100° {212° F.] or even 180° [356° F.], acquires. this. property very manifestly, and independent of the light that Mey accompany it, mm propor tion as the temperature, of. ul e heated body is increased bey ond this. ‘The rays emitted, simultaneously by one and the. same, heated body differ from each other with respect, to the: fa~. culty of traversing glass. The quantity of radiant caloric emitted, or, to ca more properly, the quantity of caloric arriving at a distance in the radiant form is not proportional to the, temperature of the heated body, . as. commonly supposed, but it is infinitely’ greater in proportion at high temperatures, than at lower. Lastly, that the law of refrigeration established by New- ton, though nearly accurate at low temperatures, 1s far from ‘ being so at high ones. ; Phenomena of Nothing very striking has occurred ‘here in the sciences Het, within these few months. Mr. Malus is still pursuing with success his inquiries concerning polar ised light. Mr. Arago likewise is making some curious experiments on the IMuminationof same subject. Some, that he has lately made on the illu- eet . mination = third order of particles, and of attraction, influences che- ON CHEMICAL ATTRACTION. 193 munatien of different parts of the solar disk, show, that the degree of illumi ination of the edges and of the centre is precisely the same, contrary to the opinion generally PS Dediouannee ceived. Mr. Clément has very happily applied prof. Leslie’s animal and vee process for the formation of ice to. the rapid and complete preinrin. dessiccation of various animal and vegetable substances. Ele Evaporation! has also. greatly improved the apparatus, for. evaporating li- quids by the help of fire. y VIII. On Chemical Attraction. By Marswar Hatt, Esq. ‘To W. NICHOLSON, Esq. SIR, \ ~ Cuemicar attraction is that force, by which the parti- Chemical at- cles of matter are’ drawn towards eachother. © These parti- i aegelal cles are of two kinds; for they may’be similar to each other, — as in. the same simple body, when they are termed homo- geneous; or they may be dissimilar, as in a compound body, and are then denominated heterogeneous. From this ~ distinction between the particles of material objects, a divi« sion of the attraction, which unites them, immediately flows, The force, which occasions similar particles to cohere, is called homogeneous attraction; dissimilar particles are united by Homogeneous heterogéueous attraction: the former is the cause of co- mene ay hesion in simple bodies; the latter occasions combination tion. between different bodies. But, beside these, philosophers have supposed, shat a A third order of ‘particles and of attrace mical actions. “ Heterogeneous affinity urges heterogene- tion supposed. \ .** ous particles toward each other, and of conrse is the cause sof the fermation of new inlegrant particles, composed of | ‘a certain nuniber of Ee ee particles. These new — *6 particles afterwatd unite by cohesion, and form masses of “s compound bodies*.”” [ii the words of Mr. Murray, * the “‘ integrant particles ard merely the smallest particles, into * Thomson, ed. 3, vol. II], p. 408. ae! X¥XX.—-Nov i811. - : 0 pee es. 194 » ON CHEMICAL ATERAC TION: ERITIMAIRD “© which a Mit anee can be resolved without decomposition. it ‘The integral parts are united by the force of aggregation, “ the constituent parts by chemical affinity *.” Berthollet to - describes the force of cohesion of a compound, as that by . "which the integral parts are held together t. Thishavtedto [ti is the object of the following observations, to point out ante ip a what I conceive to be an t inaccuracy, in the | opinion of com= of chemical pound integrant particles, and of the attraction by which attraction. they are supposed to be united; and especially to notice some errours, which have been introduced into the general theory of chemical! attraction, by the adoption of this opi- nion. Opinion of It is proper to premise, vehiae the opinion itself of com- ee pound integral paiticles must be atlmitted to: be ‘hy potheti- cles hy potheti- cal. We mix two substances together, , and their particles val. unite in that manner, which constitutes ‘chemical combina- tion; but to say in what precise manner they unite, I appre- ia ots hend-to'be’ impossibles, that’ they first collédt together to form-particles of a new kindy audoof aistperior order, which unite by homogeneous attraction, ig serély not very mani= fest. “(It-is‘perhaps more probable, ‘that chemical union isa Tess complicated operation. If ainumber of heterogeneous _ particles be ‘mixed together, they assume respectively that Combination -. Ee Rae oe : ‘ and agerega- Situation, which theirmutual attraction allots to them ; every tion effects of particle is probably attracted by every other; and of this adie attraction, combination and ager egation are remmeliy the os . - fects. | Clit, Nor can the beret in of ‘a compound: Sinseate ie attri= ~ buted more to the agency of homogeneous, than of hetero= geneous attraction; for if, in a compound, the particles be drawn towards each other, itis of no importance whether these particles be similar or dissimilar; the same effect, in ' point of cohesion, will be produced. The contrary >The account therefore usually given of the formation of Hapewiesis ined integrant particles of a compound, which unite -by ho- probable. : 2 : ‘ ‘ . mogeneous attraction, or cohesion, is not only without proof, but, as I humbly conceive, without probability. We shall > ee however admit the opinion, and pyoceed to consider how it hal Murray, éd. 2, vol. I, p. 63. + Researches, p. 38. ‘Pe da: Hig records ON CHEMICAL ATTRACTION. 195 accords with and explains the phenomena of chemical com- bination. — Berthollet, in his researches on this subject, has aseribed Cohesion sup- many phenomena to the operation of the hoinogeneous at- ae oe traction, which unites integrant particles, or, as it is termed of chemical af by him, cohesion. He cousiders it asa powerful cause in “nity. modifying combination; and especially, he attributes many of ‘tlie results of complex affinity to its influence; he sup- poses, that Bergman’s Tables do not represent the real or- der of the affinities of bodies, but rather, the degree of CO hesion possessed hy the compound when formed *, The following illustration is given of the mode of operf- Instanced in tion of this force of cohesion. ‘If a solution of sulphate eh ane “© of potash be mixed with muriate of lime dissolved in a eearate of * small quantity of water, the lime brought into contact lime. s with the sulphuric acid will be more powerfully influenced “ by the force of cohesion, than the potash. It is therefore **aforce in addition to those which preexisted, and deter- ‘S mines the combination of the sulphuric acid with the lime, ‘and the precipitation of the new compound f.””~ As this paragraph com prehends much of therdoctrine of This instanos the influence of cohesion in modifying chemical union, it eee deserves particular notice, and it will bet of advantage to thake a few observations on it. ‘It may be inquired, what is to be understood by the lime The lime does being brought into contact with the sulphuric acid? Ische- stronger fore mical*contact or chemical union intended? It is difficult to of cohesion than the potash determine this question. “If chemical union be pot inteaded Bifore deapin by the word contact, it is improper to say, that the lime wil} position has be more powerfully influenced by the force of cohesion, than aes the potash; for maniate of lime is more solublethan sulphate of potash. Let'us suppose, that chemical union is intended, and we shall still observe a manifest impropriety‘in the ac- count of the infuence of cohesion which followse) - It is said, that cohesion is a force, in addition to those A power that which. preexisted, and determiues, the combination of the pees sulpharic acid and the lime, and the precipitation of the hastaken play new compound. Now it is to be, observed, that this new S2DD°t have force can only be exerted, when * the Jime-is brought into effect. ee * See Researches, p. 106, ' Ibid, p. 105. ey as O@ ** contact produced the Y 196 Cohesion be- tween the par- ticles of acom- pound is a farce that de- tormines its. formation. ON CHEMICAL ATTRACTION. <* contact with the sulphuric acid ;”. how.then does it after- ward ‘ determine the, combination of the sulphuric acid: with the lime?” A. power which is only evolved at the in- stant of the combination of two substances, cannot surely influence, or determine that combination, Cohesion is.a power, whichis exerted hetween integrant particles only ; in this instance between the integrant parti- cles,of sulphate of lime} it has no influence before their existence, and consequently cannot contribute to, their for mation, it caunotetherefore be a. power in addition to those which preexisted, so as in)its,operation to determine ua ‘combination of the sulphuric acid and the lime. It appears to me,:therefore, that Berthellet has attributed the formation.of saline compounds to the active energy of a ‘power, the very existence of which, according to his own definition, must be coeval with, and cannot precede and in- fiuence their formation. " - Now itis to be observed, that the proposition, that cohe-~ sion ima compound is a force which determines the forma~ tion of that compound, is really a fact as well established as anyinichemistry.. For, ‘* if all the decompositions ascribed ‘* to complex affinities be investigated, it will-be found, that ‘« the prevailing affinity. has been always ascribed to: those “of forming a salt, which can be separated by crystal- Sek USAT Combination and aggrega- tion the joint effect of hete- ‘« lization *.”. The formation.of these compounds, therefore, ean scarcely be attributed te any other cause, than that which Berthollet alleges; nainely, the operation of the attraction oof cohesion in: the compounds formed. Gn the contrary, that cohesion is exerted fecieaetes com- pound antegrant particles only, nay, the very existence of | such particles, is entirely. hypothetical. The former proposi- .Fogeneous and tion ds supported by an. ample nember of experiments; the homogeneous attraction, latter, which, j asin contrad)ction to it, 1s merely matter of ‘opmion,! “Experiment, which ts the light of Nature, shows us, that: that power, which we term the attraetion of cohe- sion, does influence and determine the combination of those substances, or of those particles, which constitute a com- stg povindli ‘with much cohesion; but, as it has been shown, these 36F eS Berthollet, siscrigita a pil0GrsX son @- + . - ’ *“substanees, which have the property of precipitating, and . ‘ ! ' particles ; ‘ ON. CHEMICAL ATTRACTION. 197 > particles canriot be what are termed integrant; the constitt- ent particles of a compound are therefore made toapproach .- by the agency of the force of cohesion, just in the same manner as by chemical attraction. Where then is the dis- tinction between these two powers? To me it appears, that there is no distinction whatever; but that, in fact, aggrega- -tion and combination are both the effects of the mutual at- traction of heterogeneous particles. Inthe compound AB, each particle of A is probably attracted by every other par- -ticle of A, and by every particle of B. Now the first of these attractions is homogeneous ; the second heterogeneous. It is therefore probable, that the particlesof every conipound ._. * ‘unite and adhere by the agency of both these kinds of ate traction; it is surely improper to assert, that they unite by the agency of one attraction, but adhere by the influence of the other. It is proper to observe, that the change, sibiels is here sug- gested with regard to our opinions of the attractions of co- hesion and of combination, is not so singular as at first view it may be supposed to be, A change precisely analogous has been proposed, relative to the operation of affinity between two or more compounds. Formerly it was supposed, that, ~ when two binary compounds, for example, are submitted to mutzal action, the energy exerted in their union subsisted between the integrant or homogeneous particles of these compounds. creased by the total-prevention of all disposition to blossom, Alien ery the soil and variety. being, in all other respects, the same, it is difficult to conjecture; but Li imagine, that the expen- diture of sap in the production of fruit stalks and blossoms alone would-be sufficient to occasion an addition, of at least un ounce, to the weight of the tubeis of each plant; and if each’ square yard-were to contain eight plants, .as in the crop I have mentioned, the increased produce of anv acre would considerably exceed a tun, and of course be sufficie ent, in almost all cases, to pay the rent of the ground. Varieties suit- I do not know bow far other parts of England are well i aan supplied with good varieties of potatoes ; bat those culti- land. vated in this part of the island are generally very bad. Many . of them have been introduced from Ireland, and to that climate they are probably well adapted; for the Irish planter is secure from. frost from the end of April nearly to the end . * 1440 Ibs. of a =. ! : ' ON POTATOES, £07 of November: but in England the potato is never safe from \ frost. till Dear ‘the end of May; indeed I have seen.the leaves and stems of a. crop, in a very low situation, completely de- stroyed as late as the 13th of June, and they are generally injured before the middle, and sometimes in the firft week of September, The Irish Varieties, being excessively det are almost a. ways killed by the frost hte in full blossom; w ‘hen, omit= ting. all consideration of the useless expenditure ‘of manure, ‘at ‘may justly, be questioned whether the tubers of such plants, being immature, can afford as nutritive, or as whole- ' some food, as others which have acquired a | state of perfect |. ese maturity. . The preceding statement will I trust point, out to the Importance of Horticultural Society the i importance of obtaining improved “sateen varieties of the potato, and-I believe no plant existing to be to thiscounery. more “extensively capable, of improvement, relatively to the climate of I England ; ‘ ‘and if practical evidence were wanted to prove. the edient, to which ‘the culture of the potato is calculated to ihcrease and Support the population of 'a coun- try, Ireland ‘most amply. affords it; where population has incréaséd among the catholic poor, with almost uniprece- dented rapidity, within, the last twenty years,,! inder_ the pressure of nore distress ‘and misery, than has leapt been felt i in any ‘other. spol in Europe. aan / meee T shall conclude my present communicatiort with some re- Remarks on marks: upon the origin and cure of a disease, the curl, which sec ahaiie a few years ago get ior ved many of our best varieties of the potato; and to the attacks of which every g good. variety ‘of the potato will probably y be. subject. x observed that the leaves of several kinds of potatoes, Origin of the which | were dry and farinaceous, that I cultivated, produced “sinh curled leaves; while those of other kinds, which’ were’ soft and aqueous, were perfectly well formed ; whence I was led to suspect, that the disease originated in the preternaturally _ inspissated state of the sap in tHe dry and farinaceous varie- ties. 1 conceived, that the sap, if not sufficiently fluid, might stagnate in, and close, the fine vessels of the leaf during its growth and extension, and thus occasion the irre- _ gular contractions, which constitute this disease: and this conclusion x 1 268 Experiment to prove the truth: of the theory, Prevention of the disease, ran ON POTATOES. conclusion, which I drew many "years ago, is perfectly cori= sistent with the opinions I have subsequently entertained, respecting the formation of leaves, I therefore suffered a quantity of potatoes, thé produce almost wholly of diseased plants, to remain in the heap, whére they had been preserved during winter, till each tuber had emitted shoots of three or four inches long. These were then carefully detached, with their fibrous roots, from the tubers, and were committed to the soil; where having little to subsist upon, exéept water, I concluded the cause of the disease, if it were the too great thickness $f the sap, would be effectually removed ; ‘abd T had the satisfaction to observe, that not a single curled leaf was produced ; though more than nine tenths of the plants, which the same identical tubers subsequently produced, were much diseased. | In the spring of 1808, Sir John Sinclair informed me, that a gardener in Scotland, Mr. Crozer, bad discovered a method of preventing the cur} by taking up the tubers be- fore they are nearly fall’ grown, and ‘consequently: before they become farinaceous. Mr, ‘Crozer, therefore, and my- self appear to have arrived at the same point by very diffe- rent routes ; for by taking” his potatoes, while immature, from thé parent stems, be probably’ retained the sap nearly in’ thé state to” which my iiiode ‘of culture reduted i ite I _therefore conclude, that thé opinions I first formed are welt Sounded; and that the ‘disease may be always removed by the means I ‘etbploy ed, and its return prevented by those adopted by Mr. Crozer. | I sent to the Board of Agriculture the substance oH the preceding remarks on the origin of the curl, in’ the yeat 1808; but I do not know whether that. account has been eae or not. Deletion: é January 31, 1810, ON THE ALGORITHM OF IMAGINARY QUANTITIES. 209 XL. A remarkable analytical Anomaly respectfully submitted to the Consideration of Mathematicians. ‘ To Mr. NICHOLSON. SIR, 3 In your number for August last, I published a short On the algo» paper on the defective algorithm of imaginary quantities, tithm of ima- inary quanti- which has not at present been honoured by the remarks of ‘ties, any of your correspondents, though the importance of the subject seems to demand the attention of every advocate for the introduction of these expressions into mathematical investizations: and as I am extremely desirous to have the Opinion of analysts on this subject, and particularly those, who in their writings have maintained the legitimacy of re- sults, in cases where imaginary quantities have been nearly the only instruments employed in obtaining them;. I am induced, in order to draw a reply from those quarters, to consider the same under rather a different point of view. For which purpose let us assume the two following ex- “pressions: 3 fe Rak, Ee ae ee livy—1 + fs Vl = 3 . 3 . Yrtt tv—3 + f—f—fy—3 = ~187938 which equalities may be verified either by the develope ment of the above expressions into series, or by the solu- ' ition of the.equations of which they are the roots, according _ to Cardan’s rule, viz. 3 rim lr m= —A4 re 32 — 1 Now let us square these formule at full length, and by precisely the same steps. -Then we shall have the following el Vou. XXX.—Nov. 1si1, P (A) * 210 ON THE ‘AveoRirast OF IMAGINARY QUANTITIES. | Si) a ia eS Oe Sh) Geyer ye (A). ( V-2tuvy—1 + Yao v—1)= Jf (2 + 11/%—1)? + 2 V (24+ Tl a2 Leelee af coe 1) + af (bE 1h W— 1) ry (B).f ere PV+3'+ roma arene wey = see ae Vit +$7—3)? + aR reir v3) ese eee ct WV (— 5 iV — 3)” Cun E . Thus far-we have proceeded step by step the samein both examples, and Jet. us still contisue the same parallelism of nh at full length thus: 2+ 7h ae xf the SUN of (— 24+ 11 /”—1) —2411 v— 1 | oc me A — pep il leh =—y—sys tse eve —2+ 11 Visiys 1d the prod. of (— 2 11 M—1) (ev) a Qe TL Af ee oe ree 4 $121 f/—1 = 125 —-2—UuY—1 the square of (— 2—~ 11 f— 1) 4 —— 2— 11 Y/—!1 A AA 721 = e117 + 44 fe (ee 1)” and consequently our square (A) becomes Be ae wade oo of 117 othe he 8 16 oa oe HT ee 8 eee eee GA Cie Ss ( — —— ; f—n7 44 +10 $Y U7 + 44 y— 1 . ; rig «Again, 1 - ON THRE ALGORITHM OF IMAGINARY QUANTITIES. 91) Again, to square our second formula (B) oni |. ail aot the square of (— 4 + 4/— 3) r a . ; by L—iv—3 —-$=>—t—ty¥—3= t+ tv—3)* matav= ° the product of (44 3 v3) ot — 2 73) vin 3 —+t aft the square of (— 4 — pti 3) Peers -EVv—-S— f= —$ + t$V¥—3 = (}—Fv— 3) And consequently our square (B) becomes Mi oh Caee tiie at Se 3 ; Vrertv—8t2Vit Y-itiv—s= ie ee 3 ih . >) tapi remhch aeedaniedaila tact i aa Thus far likewise we have proceeded step sup ater in both Operations. “And since our first formula is equal to — 4, and our se- “cond to — 1*87938; the square of the former ought to be equal to 47 = 16, and the latter to (1°87938)” = 3°532069 ; that is we ought to find the following equalities obtain: viz. eS ooo A)... — 117 — 44 V—1 + 10 + Y—117 + 44 —1 = 16 : 3 3 % (B)... f~—t—4V—3 424+ f—ttiy—3 = 3532069 Or by transposing 10 and @ - : 3 pe He SR RY ea Bn Eat a8 + PAPE Tyas = 8908 P2 Now ‘ON THE ALGORITHM ill IMAGINARY QUANTITIE£S. On the algo- Now V— SAT en Af fe Bis pe ae | rithm of imaginary quantitiese yg a) } and. /— 117 4 1 ‘as will be-foutd by involution. ~~ And consequently their sum is equal to 6 as it ought to be,-and we may therefore fairly conclude, that we are ‘right in ovr operation on the first formula. ‘But with regard~to our second expression, itis the same as that with which we begun, and is therefore equal to 1'87938, and not 1°532069, _ as it ought to have been, had we been correct in the opera- tions ‘on the second formula; and “hence we may conclude, with equal certainty, that some mistake has crept in unob- served in the latter case,’ notwithstanding we-have proceeded by parallel steps in both examples. The questions, therefore, that I have to propose to mathe- maticiays,-are-as-follows : “= 1, What constitutes ‘the errours in the operation on the latter formula? 2, Howare such errourstobe guarded ag ‘aint in other. cases P The latter of these questions is pene important with the former; ‘as there’are various other formule of a similar description, which, should they arise in any investigation, when we have not, the means.of checking the result as in the examples above, much uncertainty must mRecesegrily at- tend. the conclusions thence deduced. The manner in which I have introduced these questions may appear somewhat novel in the present day, but it was not uncommon at the time when the sciences were most successfully cultivated in this country,_ “and when. they »were making those rapid advances, which have immortalized the names of several distinguished | English” mathematicians and é philosophers. T have only now to observe, that, should no:answer appear to these questions within three mouths, [ will then, through athe medium of your Journal, publish roy explanation ; but 1 am not without hopes of seeing the subject elucidated by _» more able hand-than, Sir, | Your Ghedten? Servant, MATHEMATICUS., ON THE MIGRATION OF SWALLOWS. 2913 XH. On the Migration of Swallows: by Dr. Trattu. Read be= Sore a Literary and Philosophical Society established at Derby, Sept. the 17th, 1808, 0f which Dr. TRatut is@ Corresponding Member. “To Mr. NICHOLSON. SIR, Your correspondent Mr. Forster having solicited in- Migration of formation on the subject of the migration of swallows, Dr, S¥4llows. 'Traill was induced to request, that the following paper, after having been read to the Derby Society, might be' transmitted to you for publication. In compliance with that wish it is herewith enclosed ; and, I have no doubt, will be considered as an interesting contribution to this curious branch of natural History. lam, Sir, Your very obedient Servant, Derby. CHARLES SYLVESTER. - Extract Srom the Logbook of the Ship ae of Lancaster Captain Joun THomson. . On Whe 17th of May, 1807, in latitude 51° 42’ north; longititude 21° 44’ west. Pleasant clear weather. Wind W.N.W. © 18th. Pleasant clear weather. Light airs and calms, Wind varying from S. E. to E.N.E. Lat. D. R. 52°6' Ne 5 long. 21° 44° W. 19th. Steady breeze from. E.S.E. Some showers of rain, and fogey weather for the most part of this day. Lat. | ip. R. 52° 11: N.; long. 21°.16° W. 20th. Strong iptizes, varying from S. to S, E. Foggy eid cs weather. About 4 p. m. several martins and swallows ap- swallows light. f peared about the two ships. At’ 8 p.m. collected toa large alerts ae covey ; many of which pitched on different parts of this ship, Jantic in May. ' and allowed themselves to be taken up by the seamen. At. ane in the morning found many of them dead in the mizen Oo} 4 | ON THE MIGRATION OF SWALLOWS, mizen topychannel bends, and on deck. Lat. D. R, 52° 33’ N. Long. 20°21’ W. 21st. Continues foggy, attended with rain. Wind mostly from south-eastward. Iu the course of the day great numbers of the swallows a1.d martius were taken by the seamen; and the cats and dog brought many ot them. A great many had pitched in differen: parts of the ship; and all or the greatest part found dead in the morning. Remarks by Dr. TRaiuu. The intelligent seaman, who made this extract from his » logbook at my request, was iben on his veyage from the West Indies. He bas been many years captain of a ship, in. the West India trade from Lancester, and from this port. I know him to be a man of probity and veracity and his account w as confirmed by some of the mariners aE the ship then in company, with whom I conversed. The circumstances chiefly to be attended to in the nar- ration, are: ate They were ap- 1. The weather, previously, was not so boisterous as to tee countenance the idea, that the swallows were forced by a from Atrica to tempest from thenearest shore; and the ceneral direction ee ere of the wind was not unfavourable to the supposition of their the land bya having been aidcd by it, in their passage ‘rom the coast aes of Africa, where they were observed by the celebrated, pas unfortunate, Adanson, to arrive in the winter. 2. The season of the year is favourable to the BM of their migration from the coast of Africa for the north. of Europe. They alighted on the ships about the time that swallows begin to appear in Britain, to.which they were pro- babiy proceeding; and it should not be forgotten, that about this time of the year swallows are seen to quit the coast of Senegal, and other parts of Africa. 3..The debility of these birds, which permitted them to. fall an easy prey to the cats and dog; their suffering .them- selves to be caught \by the seamen; and their. being very lean, as [ was informed was: the case py those who. exa- mined them, in the two ships, seem to show, that they had made a long voyage, and not, that they nad been accei- dentally dfiven by a gale, from the neighbouring shores of Britain .ON THE MIGRATION OF SWALLOWS. 215 Britain and Ireland. Indeed, considering the great strength of wing, and velocity, of the swallow tribe, it must have been a tremendous gale that could drive them off the land: _ but, the previous weather was nothing boisterous, and cap- tain Thomson experienced little more than a steady breeze. 4. The great number of these birds is another argument against the supposition of their having been carried to sea by a storm. Such instances in solitary birds of weak wing are not uncommon. I once caught a golden crested wren (motacilla regulus, Lin.) iu the shrouds of a vessel, when driven off the coast of Scotland by a sudden tempest ; but instances of large flocks of birds, so strong and active as. the swallow tribe, becoming the sport of the winds, are certainly very uncommon, even when the weather has been tempestuous. 5. Captain Thomson expressly mentions both swallows There were at and martins; and he stated to 4ne, that they differed in cS rem Se size. Hence, there were, at least, two species of swallows observed by him. As he does not pretend to the character _ of a naturalist, perhaps, there were not only the chimney swallow, or hirundo rustica, and martin, or h. urbica, but . the swift, or A. apus, and even the sand swallow, or h. ripa- ria. ‘This account, at least, supplies, in some degree, an omission of Mr. Adanson ; who, in his interesting observa- tions on the appearance of swallows in Africa, has omitted to state what species he observed there, or whether he ob- _ served more than one kind of swallow. The preceding extract affords, in my opinion, another Their being _ argument to prove the annual migration of swallows, That “gay A oss swallows. sometimes have been ad dormant, in the win- questionable. ter season, in cold climates, I am not disposed to deny. But had a bird so common with us generally remained here all the winter in a dormant state, we; probably, should have discovered it more frequently than has ever been pretended. I will even admit, that swallows have been found concealed amid rushes, by the banks of rivers, in this state: but that they have ever been discovered alive at the | bottom of pools and rivers, or otherwise excluded from the access of atmospheric air, we must be permitted to doubt, : all it is proved, that the respiratory organs of swallows differ 216 LUMINOUS METEOR OBSERVED AT GENEV4, differ from those of other birds ; or, that atmospheric air unnecessary to the life of dormant animals. The extracr- dinary suspénsion of most of the living functions of ani- mals of this class is a subject of great physiological ime . portance aud curiosity; and deserves to be more fully in= No unusual vestigated. But the claim of the swallow to an unusual structure of — structure of the organs of respiration is completely overe the organs of Pig cee ; 4 respyation in turned by the dissections of the celebrated Johu Hunter. swallows. Tu the alleged cases of the submersion of swallows we must make allowance for thecredulity, of inaccuracy, of observers ; and I think it would not be difficult to refer almost all sucn alleged facts to one or other of these heads. Liverpool. THOMAS STEWART TRAILL. ~ XUL Account of the Appearance of a Luminous Meteor: by Pro= Jessor Picret*. Luminous me- "Tar 15th of this month, about half after eight in shee even: Ho oj at ing, alaminous meteor was seen at Geneva, in the N.N. W. + Mh part of the sky, which was pretty clear where the meteor aps peared, though there were clouds in other parts, and the _ phenomenon itself, toward the end of tts appearance, was ob- scured by a cloud. The appearance was so sudden, that those of the spettators, who were looking another way, at the first moment supposed the light it gave, which was suffi- ciently vivid to cause a shadow, though it was still twilight, to be the effect of a flash of lightning. We have ended= voured to collect all the particalars respecting thé circom- . stances of the phenoménon, that we could obtain from éye- witnesses of it. Among these may be distinguished five students of the academy, of the faculty of sciences, wha happeried to be walking together, and not only sdw, but mauve iheir observations on this phenotnenon, which they afterward committed to writing. These, except the noise, which was heard only hy thet, agree with all those, ‘that have been communicated to tis by Bibets with léss precision. The following are their words. * Ribliothéque Britannique, for Mav, 1811, p. 105. 6¢ The / LUMINOUS METEOR OBSERVED AT GENEVA, O17 ©The 15th of this mofith, at 35 minutes after eight in Description of the evenivg, we heard a whizzing sound in the north-west. ™ A sudden flash of light caused us to turn our heads, and we saw a kind of serpent of fire, which appeared to us four or five degrees in length, It was bent back at the west end, so as to approach the figure of the letter S; it then spread outin the lower part ; after which it assumed the shape of 4 horseshoe, and nearly of a parabola. At the end of seven or eight minutes, according to our watches, a cloud con- cealed it from our eyes, at the moment when it appeared to advance very slowly toward the west. Its brightness dimi- nished every instant; and justat the time of its disappearing we no longer perceived any thing but two very bright points, one at the extremity of the tower branch of the pa- rabola, the other on the saine branch nearer the summit of the curve. As to its height we cansay nothing precise, as we had no instrument with us adapted for measuring angles: but to the eye it appeared twice the height of mount Jura.” One of the eye-witnesses of this phenomenon*, who ob- Composed 6f served it with a sinall telescope, remarked, that the most Se luminous part was not homogeneal, or continuous, but coms posed of distinct and separate particles. A fortunate circumstance enabled: us to determine with Its apparent tolerable precision the important circumstance of the appa- Height, yent height of the meteor, which was for a long time nearly stationary. - Two of its observerst, whom we consulted, re- marked that the meteor, seen from a spot which they easily found again, ‘grazed the summit of a certain tree, which even concealéd part of its light: We afterward measured from the spot of obsérvation the angle of altitude of this tree; and its azimuth. This altitude, and consequently that of the meteor, was eighteen deyrees; and its azi- muth was precisely in the direction of the magnetic me- Its azimuth. tidian, which ut present at Geneva is 20° 15'N. W. This direction passes nearly through the zenith of ihe towns of Gray,: Langres, Chaumont, Vitry, ‘Chalons sur Marne, Rheims, Valenciennes, aud Bruges, > #Mr. Trembley. nephew of the celebrated naturalist. +Mr WLhuilier, professor of mathematics in the academy; and Mr. Galland, student in the faculty of divinity, ae We ” 218. EUMINOUS METEOR OBSERS ED AT GENEVA. It was seen 2t_ We have learned by the public papers, that this metear Paris. was seen at Paris; but itis not saidin what direction. Sup- posing it to have been seen due east, theiutersection of this azimuth with that observed at Geneva would point out the place of the meteor in the region of Vitry, Chalons, and Bar sur Ornain, about seventy leagues in a straight line Fstimation of 246m. Geneva: a distance which, with its apparent observed its real height. height, and taking into account the effect of the sphericity of the Earth, would place the meteor about the-actual height of twenty- -four leagues and half. The supposition we have made, for want of observations, may serve as a guide to those, who remarked nearly the azimuthal direction of the phenomenon, and would form an idea of its absolute height. It must have been less than 242 Jeagues, if the meteor were seen in a direction to the south- ward of east; and on the contrary so much more, in pro- portion as it appeared more to the north of the perpendicular to the meridian of Paris. Above ourat- Atany rate it appears, that its height exceeded the sensi- mosphere. ble limits of our atmosphere; and that its light, and proba- bly its heat, did not.arise, as in our ordinary combustions, from the presence and decomposition of the CREE gas of the atmosphere. Probably Several circumstances of this phenomenon were similar to seats fell Vth those that have been observed in lapidiferous meteors; and -. we should not be surprised to hear, that incandescent stones had fallen in places, which had this meteor in their zenith. No explosion was heard; but perhaps the distance was too great, and the circumambient medium too rare, for the so- norous vibrations to be transmitted to us. , - | sige: fe Leiter from Professor P. Prevost, to Professor Pierer on the Meteor of the 15th of May*. i | GENEVA, May the 28th, 1811. Comparison of | HE care you have taken, my dear colleague, to deter- _ ercumstances mine exactly the position of the meteor observed the 15th * Bibliotheque Britannique, for May, 1811, p. 110. ©» of ¢ LUMINOUS METEOR OBSERVED AT GENEVA... 219. of this month, will allow it to be compared with those ascer- of meteors de- tained by other observers. This is the only method of ob- : nie taining any accurate ideas respecting the vertical height, course, and nature, of these bodies foreign to our Earth, and the short. passage of which cannot be foreseen. You have availed yourself ofa favourable circumstance, Guesses at to obtain the altitude and azimuth of that luminous object ; thei" heights and distances but it is far from probable, that observers in other situations not to be de. should be able to avai! themselves of a similar proceeding : | peuded on and should they report the height of the meteor, without having determined it by any instrument,‘ we must expect great deviations. There is a certain, degree of confidence however, to be unless by ex- given to the estimations of men'accustomed to appreciate teas poe their sensations, and compare quantities. If therefore such an observer should say, that he saw the meteor nearly at 45°, or at 30°, for example, this might be considered as pro- bably coming pretty near the truth: because we muy pre- sume the observer, measuring in idea the interval from the zenith to the horizon, could pretty well estimate by the eye the half or third of that distance. But there is a correction to be made in this estimate, Necessary cor- 50 FY vedo sated which is scarcely thought of, but which, in loose observa- itaaae ps tions of this sort, is in reality of great importance. these, ~The apparent firmament is a skene arch, which may be from the appae compared to an arc of a circle of about 60°: (see Smith’s Eine Optics, translated by Pezenas, vol. I, p. 117). If we con- -strugt.a semicircle on a right line, and cut off an arch of about 60° to represent the apparent firmament, (as in the figure i in Smith’s Optics), we shall see, that half from the vertical, of this apparent firmament answers to about 30° of - real altitude, and a third to about 40% Now it is easy to perceive the importance of such a correction, if we would obtain any accurate result. from comparative observations, and in particular if we attempted to ascertain a parallax. Jn confirmation of this remark I lay before you the ob- Estimation by servation of a man possessed of all_the faculties calculated 2" observer at to mature his judgment in the estimation of measures. You es will there see, that he estimates the height of the meteor » between ax IMPROVEMENT IN THE AQUATINTA PROCESS. between 30° and 40°, that is between } and ¢ of the appa- rent distance from the zenith to the horizon, These points: of division of the apparent firmament answer to 14° and 20°* of real alitude: and that of 18°, which yoo have measured; is between these two. LT ought however to addy that the ob- server in question ultimately fixed. on the estimate ofa third, or 30° apparently. But all these determinatious.are neces- sarily approximations only. XV. Improvement in the Aquatinta Process, by which Pen, Pencil, and Chéik Drawings can be imitated: by Mr. J. Manin. No. 11, Clement’s Inn}. SIR, Tmitations of Percenv ING the various methods of imitating draw- black lead drawings im- ings and sketches in the graphic art fall short of an accurate periect. imitation of the black-lead pencil, 1 determined on an at- tempt, some years since, which, after repeated experiments, I flatter myself I have fully established. eres The subject The manner is totally new, and solely my own invention : wrote eit —by the method I adopt any artist can sketch with a black- a pencil imme- lead pencil his subject immediately on the copper, and so diately on the simple and easy is its style, that an artist can do it with five rat ae minutes study. No retracing | By this manner, the trouble in tracing an oi) paper, and’ mecessary. = other retracing on the etching ground is avoided, and the doubtful handling of an etching-needle isdone awayt, as the : * A third of the arch of 60° fromthe horizon would: give 20°, and Le 2a 405, Cy + Trans. of the Soc, of Arts, vol, XXVIU, p 97. The'silver dei and thirty guineas were voted to Mr. Hassell for this communication;. 7 } Tracing rag should be made of a piece of Irish linen, not'too inucti ~ worn, the surface of which is to be rubbed with another rag dipped! in sweet oil, just’sufficient to retain a small portion of vermillion or pounded » yed chalk. This must be placed with the coloured part towards. the, ; ground of, the plate, and the drawing or tracing laid upon it, which must,, be traced very lightly with a blunt point or needle, Tracing rag. peneilling “IMPROVEMENT (EN THE AQUATINTA ;PROCESS, 921 penciling onthe copper is visible iu ‘thesmallest touch :—It »has-also.another perfection, that, by using a broader instru- Black chalk ement + will crepresent black-chalk, a specimen of which I rig procured Mr. Munn, the landscape painter, to make_a trial of. Ihave herewith sent the said specimen marked C, and Mr. Munn’s name is dfixed to the same. This subject he. actually drew ‘upon copper, under my inspection, in less than twenty minutes, the time he would have taken, per- “haps, to do the same on paper ;_ in fact, it can be as rapidly executed on copper as on paper. It is particularly pleasant for colouring up, to imitate Particularly ‘drawings, as the lines are soft, and blend in with the colour, feotines for co It is a circumstance always objectionable in the common jmethod of etching, that: those'so tinted.can ‘never -be suffi- -~eiently drowned, nor destroyed, and always -present a wiry bhard effect. | It is equally adapted to, historical sketching, and might and:to'pre- +be'the means of indueing:many of our eminent painters to pr Aste de hand down to posterity: ‘their sketches, which, at present, painters. they decline, from the irksome trouble attending the repeti- tion of retracing their performances, and the doubtful hand- ling of the etching-needle, which can never give a sufficient ,breadth.and scope. to their abilities. -Lhave,.sir, forwarded, in an annexed paper, the different specimens, for the inspection of the gentlemen forming the Society of Arts, &c. ep making my specimens I have thought it necessary to ay part capa _show, that, ‘ by any accident a part might fail, it could be a ‘retouched a second time, and oftener if wanted ; in this par- _ticular- its simplicity stamps its use. To elucidate the foregoing proposition, I purposely caused “a part of the distance to fail in specimen A.A; this is repair- "ed you will perceive in specimen B, and the sharp touches ‘wanted to perfect the sketch are added. _ Lbegialso:to state, it is not the-style usually termed:soft Not soft aground etching: that process is always uncertain, cannot be ground etch-. “repaired, and will only print about two hundred impres- iia “sions; whereas the specimens herewith sent -will print up wards of five hundred, with care. Should ‘the Society for the Encouragement, of Arts &c. deem 899 IMPROVEMENT IN THE AQUATINTA PROCESS. deem the subject worthy of their reward, I shall feel proud jn communicating its process, and flatter myself the arts and artists will feel a peculiar. addition and pleasure in its utility, Permit me, Sir, to subscribe myself, with all respect, Your obedient humble Servant, JOHN- HASSELL, Landscape Draughtsman, 11, Clement’s Inn, Strand. Process of drawing upon Copper, to imitate Black-lead Pencil or Chalk. Method of A remarkable good polish must be put on the copper with drawingon = an oil-rubber and crocus martis well ground in oil; after casey HEUER which it must be cleaned off with whiting, and then rubbed pencil, or with another clean rag. soe You are then to pour over your plate the solution to.cause ground, which is made as follows ;— No. 1.—Three ounces of Burgundy pitch. One ditto of frankincense. Preparation of | These are to. be dissolved in a quart of the best rectified theground. spirit of wine, of the strength to fire gunpowder when’ the spirit is lighted. During the course of twenty-four. hours this composition must be repeatedly shaken, until the whole appears dissolv- ed; then filter it through blotting paper, and it will be fit touse*, : Application of In pouring on this ground, an inclination must he given i to the plate that the superfluous part of the composition may run off at the opposite side,"then place a piece of blot- ting peper along this extremity, that it may suck up the Grounds. * The ground in hot weather must have an additional one third of spi- rit of wine added to it for coarse grounds, to represent chalk; and one — _ half added to it for fine grounds, to represent black lead pencil ;, and always to be kept ina old place in summer, and a moderately warm. situation in winter. N. B.<—If any parts are not bitten strong enough, thes same proces is to be repeated. ground IMPROVEMENT IN THE AQUATINTA PROCESS. - 983 : ‘ground that will drain from the plate, and in the course of a quarter of an hour the spirit will evaporate, and leave a _ perfect ground, that will cover the surface of the copper, hard and dry enough to proceed with. ; ‘With an exceeding soft black-lead pencil sketch your de- sign on this ground, and when finished take a pen and draw with the following composition, resembling ink: if you wish ‘your outline to be thin and delicate, cause the pen you draw “with to be made with a sharp point; if you intend to repre- sent chalk-drawing, a very soft nib and broad-made pen wili 7 ine le yin or a small reed, sion 2.-Com position, resembling ink, to'draw the:desigag on the copper. Take about one ounce of treacle or sugar candy, add to Trik for draw- ie three burnt corks reduced by the fire to almost an ingon it. _ impalpable powder, then add a small quantity of lamp-black to colour it; to these put some weak gum-water*, (made of gum-arabic), and grind the whole together on a stone with amuller: keep reducing this ink with gum-water until it ‘flows with ease from the pen or reed. To make the ink discharge freely from the pen, it must _be scraped rather thin toward the end of the nib, on the back part of the quill, and if the liquid is thick reduce it with hot water. Having made the drawing on the copper with this com- Varnish. _ position, you will dry it at the fire until it becomes hard: then varnish the plate all over with turpentine varnishf. . It will now be necessary to let the varnish that is passed over ‘the. plate, dry, which will take three or four hours at least; Bit * Gum water must be made in the proportion of half an ounce of gum _arabie to a quarter of a pint of water. + Turpentine varnish is composed of an ounce of black resin to an _eighth part of a pint of spirit of turpentine; if the weather is excessively warm, it ought to be made with a sixth part of a pint of spirit of turpen- tine. {I apprehend there is a mistake here, and that the proportions of spirit should be reversed ; as more of the liquid would, no doubt, be required in cold weather ies in hot. C.] | but £24 Mode of tub- bing off the touches, IMPROVEMENT IN THE AQUATINTA PROCESS. but this will depend on the state of the weather: for if it thould be intensely hot, it ought to be ieft all night to har- den, Now the varnish is presumed to be sufficiently hard, you may rub off the touches made with the foregoing described ink with spittle, and use your finger to rub them up; should it not come off very freely, put your walling-wax round the margin of your plate, and then ,pour on ,the touches some warm water. but care must be taken jt is not too hot. | The touches now being clean taken, off, wash the plate well and clean from all iropurities and sediment of the ink, with . cold soft water; then dry the plate .at a distance from the . Acid. Biting in. fire, or else in the sun; and when dry, pour on your aqua fortis, which should be in cold weather as follows :— To one pint of nitrous acid, or strong aqua fortis, add two parts, or twice its quantity of soft water. In hot weather to-one part of nitrous eps: we piece 0 a of water. In every part of this process avoid hard or pump water. The last process of biting in with aqua fortis must be closely attended to, brushing off all the bubbles that arise from the ‘action of the aqua fortis on the copper. 4 ‘In sammer time it will take about twenty minutes to get ‘a sufficient.colour: in winter perhaps half an hour, or more. Stopping out. the depth of To ascertain | the work, All this must depend on the state of the atmosphere and temperature of your room. If any parts require:to be stop= ped out, do the same with turpentine varnish aad Jamp-~ black, and with acamel-hair brush pass over thosé parts you consider of sufficient depth; distances and ‘objects receding from the sight of course ought not:to be so deep as your fore-grounds; accordingly you will obliterate them with the foregoing varnish, and then let it dry, when you ° will apply the aqua fortis a second time, and repeat this just as often as you wish to procure cifecent meBeeys of colour. ‘Every time:yous eile off the agua fortis the woth simian be washed twice with soft water, and then set to dry as beiore. To ascertain the depth for your work, you should rub a small part with a piece of rag dipped in turpentine, and then apply IMPROVEMENT IN° THE: AQUATINTA PROCESS. 9095 ‘ apply the finger, or a piece of rag rubbed dn the oil-rubber, © to the place so cleared, and it will give you some idea of the depth. The walling-wax i is stellen off by applying a piece of light- Removal of ed paper to the back of the plate, all round the opposite Seg amet : J ish part of the margin where the wax is placed; then let the plates:cool, and the whole of the grounds &e. will easily come off by washing the plate with oil of turpentine, which must be used by passing a rag backwards and forwards, until the whole dissolves, it is then to be cleaned off by rags3 and care must be taken, that no part of the turpentine is left hanging about the plate. The plate should only pass once through the press, | Printing, Sir, Eharing the conference of the Committee of Polite Arts The author's last Monday evening, an Essay on the Art of Aquatinting ©!#'™ ‘o the : : ¢ invention, was produced, which, until that. period, I had never seen; aes then, Ihave procured acopy, and carefully perused As far as theory goes, respecting aquatinta, I allow it fo be fair; but upon the practical part It is positively wrong, and what relates according to the opinion of your Committee - as referring to my invention of the imitation of chalk and _ pencil-drawing, I can prove, by incontestible evidence, that I did produce specimens of my invention as far back as the year. 1795 to the public, since which time I have improved the principle. I flatter myself your goodness will enforce on the minds of. ‘those gentlemen who were present, that I ought personally to prove the same, which I am prepared with documents to do. Permit me, Sir, to remark, after a lapse of fifteen years, that surely some person might have produced figures and landscapes sketched in this manner; but not a single artist, to my knowledge, ever gave one specimen to the public ex- cept myself, though my examples have been before them all the above time. It i is upon the application of the manner for freedom of imitating drawings, that I conceive it to be of importance, ‘Vou. XXX.—Nov. 1811. Q and 296 ~ The author's _¢laim to the jnvention.s \ NATURE OF OXIMURIATIC ACID. and from this circumstance in pointing out its utility, I claim a credit from its originality. If, Sir, it was previously known, why was it not in use? The fact appears to me, that no person, except myself, sires of spiuin the pains _ to study the subject. | New gas supe Having thus brought it publicly to notice, I still feel a degree of pride in furmshing an additional and easy step to the promotion of the arts, I have now, Sir, to apoligize to you for trespassing on your patience, and as it is not possible for any gentleman to have taken more trouble, or have paid a more polite atten- tion to the circumstance, I thought it mest decorous to submit this memorial to you, as one of the Chairmen of the Committee of Polite Arts. Trusting, Sir, you will be so good as to communicate the same to the Committee, I beg to subscribe nya with all respect, - Sir, Your very obedient humble Siariveite es _ J. HASSELL. No. 11, Clement’s Inn, May 10, 1810, To J. T. Barber, Esq. A Chairman of the Committee of Polite Arts. XVI ma Qn the Nature of Oximurtatic Acid Gas, and the Conversion of Carbonic Oxide jnto Carbonic Acid by it, in Reply to Mr. J. Davy. Ina Letter from Mr. J, Murray, Lec- turer on Chemistry, recall . To MR. NICHOLSON, SIR, I Have not seen until lately Mr. J. Davy’s communica- tion in your Journal, for September last, and I embrace as early an opportunity as occurs to me, of offering a few obser- vations in reply to it. | - _ The most important part of this communication is” that, which : NATURE OF OXIMURIATZC ACID. 997 which relates to what he considers as a new gas, the opera- posed to ac- tion of which, he supposes, serves to account for the pro- Seauasinene duction of carbonic acid, which 1 have found to be the re- carbonic acid. sult of the mutual action of oximuriatic acid, carbonic ox- ide, aud hidrogen gusses. It is produced, he states, by ex- posing a mixture of equal volumes of carbonic oxide and oximuriatic gas to light, and he regards it asa compound of these two gasses. I had already performed iii experiment without obtain- Not produced ‘ ing the results he has described ; and I am not aware of any ote revetha fallacy, by which this can be accounted for; there was no Murray’s, ‘ sensible production of carbonic acid (the point I had it more pafticularly in view to ascertain by the experiment) and after agitation with water to remove the oximuriatic gas, the carbonic oxide was recognized by burning with its usual blue lambent flame, and forming carbonic acid by its -combustion. This result of the nonaction of oximuriatic gas on car- Oximuriatic bonie oxide gas, when both ure perfectly dry, has been polar _lately:asserted still more strongly by Gay-Luesac and The- notacton each nard, and the térmsthey employ are even unusually decided, “Me: After observing, that the carburetted hidrogen gasses are acted on by oximuriatic acid gas when exposed to light, they add ** mais 4 quelque dose qu’on ait mélé le gaz acide mu- - Fiatique oxigéné sec, et le gaz oxide de carbone préparé avec le fer et le carbonate de barite, quelque fort qu’ ait été la lumiére a laquelle on les a exposes, enfin quelque long qu’ ait été le contact, il n’y a point eu d’action®”. IfT ; _ have been deceived therefore, : is in common with chemists _of the highest reputation for the sccuracy and delicacy of their experimental researches, These circumstances how~ ever lead me rather to believe, that there s some peculiarity necessary to the success of Mr. J. Davy’s experiment. [ unless possibly know sufficiently the disadvantage to which any experi- mides peculiar, * Recherches Physico Chemiques, T. 2d, p. 192. ss But in whatever proportions we mixed dry oxigenized muriatic acid gas, and carbonic oxide gas procured by means of iron and carbonate of barytes, however strong the light to which they were exposed, ad jastly however long they remained in contact, no action between them took place.” C ] Q 2 ' - mentalist 298 : NATURE OF OXIMURIATIC ACID. circum mentalist ts subjected, who undertakes the examination’.of Paes experiments of which only a general account is givens and, from both these consideratious, | am induced to suspend eny experimental investigation of this subject until. the more full account, which Mr. J. Davy announces he is to give of his experiments, is published. At present, 1 shall admit the production of this new gas, and shall offer merely }a few obs servations on its relation to the present controversy. : Carbonic ox- In my first communieation T had-stated, that, when oxi- ie: ih muriatic acid, carbonic oxide, and hidrogen gasses are sub- oximuriatic mitted to mutual action, the carbonic oxide is converted a almost intirely into carbonic acid. This result,.inconsistent with Mr, Davy’s hypothesis of the nature of muriatic and oximuriatic acids, was attempted to be explained by the ase sumption, that a portion of the water introduced to absorb the product of the action of the gasses had suffered decom- position, and that from this oxigen had heen communi- cated to the carbonic oxide, so/as to convert it into carbonic acid. Messrs. Davys, therefore, i repeating these experi- alleged.itobe ments, employed ammonia to condense the product; and from the de- dapipblicn GF" with this variation they found the carbonic oxide to remain water. unchanged, _ Thisdisproved.. ‘Though satisfied, that there was no probability in this as- sumption of water being decomposed, I thought it proper to repeat the.experiment with the variat on-of condensing the product by ammonia. The result was still the’same as:that which I had before obtained. Nearly the whole.of the care bonic oxide had disappeared, anda concrete salt wxsobtained, which effervesced strongly on the contact of a diluted acid, and also gave indications of the. presence of carbonie acid by the test of muriate of barytes. J concluded therefore, as I believe any chemist would have done from these.results, “¢that the production of carbonic acid in this experiment ** was.established beyond the possibility of doubt.” The same re- Precisely the same results liave now been obtained by Mr, aa J. Davy. Repeating ‘my experiment on the exposure of Davy, the mixture of the three gasses to light, he detected, ‘after the addition of ammonia, no traces of carbonic oxide”: and he perceived, as I had stated, “an effervescence.oi the am- weniace salt formed with nitric acid:”” an effervescence prs which NATURE OF OXIMURIATIC actD. 299 which he farther admits to be owing to the disengagement oficarbonic acid. “The dispute:therefore with regard to the fact is at un end; and the. production of carboni¢e acid in these experiments, which ] had always maintained to be the result, but which Messrs. Davys had denied, is established beyond the possibility of doubt. Mr. J. Davy, however, forms a singular conclusion with His conclut regard ‘to this. Having stated the results of his experi+ : _-ments,he adds: ‘after the precedingstatement of facts, Mr. ‘Murray, Ishould conceive, will be induced to renounce his conclusion; that the production:of carbonic acid in his expe- riment’ was established beyond the possibility of doubt; and admit, that what he considered as carbonic acid was'actually the new gas just described $ and I should likewise imagine, that this gentleman, in future, will be more cautious in his assertions and criticisms on the labours-of others.” It is but justice'to Mr, J. Davy to state-on what hip these expec tations are founded. - The result of the experiment with carbonic oxide, oximu- grounded on tiatie acid, and hidrogen gasses led hitn to repeat the expe- rue supponed iG riment‘with the two former gasses alone. Having exposed new acid. therefore’ a mixture of carbonic oxide and oximuriatic + oe without hidrogen to light, he obtained a similar result, a total condensation ‘by ammonia without the slightest res mains of carbonie oxide; By farther researches he found, that an-acid gas.is formed from: the mutual aciior of the oXimuriatic and carbonic oxide gasses, which combines with ammonia, and forms a concrete salt, and from the agency of this gas he explams the production of carbonic acid in my experiments. “* I have now to announce”, jhe remarks, “the existence of a newlacid gas, which operated: in Mr. Mutray’s experiments witheut his knowledge of its presence, andwas the cause of those phenomena, which he erroneously attributed to the formation of earbonic acid) gas.” He:supposes it: to combine with the ammonia which is added, andto form a concrete salt; and ** the decompo- “sition,” he adds, “of this ammoniacal salt with effer« ** vescence by dilute nitric acid deceived Mr. Murray.” ’ On reading this: paragraph I expected it to be proved, that no carbonie acid is disengaged from the concrete salt, 7 - and 230 NATURE OF OXIMURIATIC ACID. and that the effervescence was found by Mr. J. Davy to be owing to the disengagement of this new acid gas. Then indeed, he would have had reason to say, I had been des ceived ; and grounds to form the expectation, that ] should renounce my .conclasion, that carbonic acid had been formed in my experiment; but inthe succeeding sentence I found, sufficiently to my surprise, the admission, that it actually is carbonic: acid, which is disengaged with effer+ vescence, that my conclysion therefore is correct, and esta+ blished by Mr. J. Davy’s own experiments; and all that his labours amount to is; that by the aid of this gas hé.can frame an hypothesis, by which this production of carbonic acid, hitherto so steadily denied by bim, may now, that he admits it, be accounted Fees in conformity to the opinion. he defends. ) The first ques- It. 4s obvious, that the first question in the ‘“‘muriatic acid to form-muriatic acid, and its.exigen by the. <<‘ carbonic oxide to produce carbonic acid, which is disen- “66 eared, hd : ¢ a , One would imagine from the manner in which the above sentence is expressed, that these were facts which had_-been _ _ experimentally toe NATURE OF OXIMURIATIC ACID. 931 experimentally ascertained. They are however a series of suppositions, some of them in Opposition even to the evi- dence, which Mr. J, Davy brings forward. ‘Tous no proof is given, that this new gas had been formed No proof that ain’the experiment. Admitting it to be formed when oxi- ila op muriatic acid’ and carbonic oxide gasses aré submitted to experiment, mutual action ; it does not follow, that it will aiso be formed when they are in mixture with hidrogen. We know it is not formed when a little water is admitted, but that the products in this case-ore muriatic and carbonic acids. It is equally possible, that hidrogen may modify their mutual action so as to prevent its formation; that in this case also these’ acids are formed on the principle I have already explained ; that the concrete salt formed with ammonia con- sists of muriate and carbonate of ammonia, and that the ‘ carbonic acid is directly disengaged from this salt by the diluted acid; There is not a single phenomenon attending the experiment as stated by Mr. J. Davy, which does not accord with this explanation.” Tt is farther an hypothesis, that this new gas is capable of farther sup. decomposing water, when disengaged by an acid from its Position, that ' 7 AR ff 3 , this gas is cae combination with ammonia ; an hypothesis assumed to ac= pable of de count for the production of carbonic acid, and supported composing by no'proof. Mr. J. Davy says, indeed, that it must ‘¢ ap- ink pear evident, when it 1s known, that this new gas neither inflames on the passage of the electric spark with either oxigen or hidrogen alone, but that it detonates violently with @ mixture of oxigen and hidrogen in proper propor ‘tions, and ‘affords muriatic and carbonic acid gas.” It is” sufficiently evident, however, admitting even Mr. J. Davy’s idea of the composition of this gas, that, when these gasses are in mixture with it, each of them exerting an affinity to one of its ingredients, without any affinity being exerted between them to counteract this, these combinations may _ be established ; while it does not follow, that, when the oxi- _ gen and hidrogen are united by a strong affinity as they are __ jn’ water, this will be overcome, and the water be decom- posed. But why have recourse to these remote and indi- yect considerations? Let the fact be at once appealed to 4° does this gas decompose water or not? It appears from ' Mr. 232 ‘ - NATURE OF OXIMURIATIC ACID: the contrary of Mra J. Davy’s.own account, that it does not; he states which appeals. merely that it, is very slowly absorbed by water. It is therefore directiy in, the face of experimental evidence to assume, that, when it is disengaged from its combination with ammonia by anvacid, it is capable of decomposing wa ter; his hypothesis to account for the disengagement.of carbonic acid falls to the: ground, and the obvious conclusion must be admitted, that the carbonic acid has been formed — by the mutual action of the carbonic oxide, oximuriatic— acid, and hidrogen gasses, and that it exiets in the concrete , ammoniacal ‘salt. / Mr. Js Davy will now perhaps perceive, that it was with some justice, that I maintained the fact of the production. of earbonic acid in these experiments, and that I did not con- sider it invalidated’ by what was stated in opposition to it. Mr. J. Davy’s He complains of an expression, which I employed ‘in the een discussion on this point, that ‘* Messrs. Davys:did not,ob- of \ir.Mur- tain ‘carbonic acid im their experiments, because they did tay"ss not look for it with sufficient care, er were not sufficiently * . aware of the sources of fallacy, by which its production might bé concealed.”’ It would, be easy to justify, this, not only from the results of. my own experiments, in. which carbonic acid was uniformly formed, results now proved by Mr, J Davy’s evidence to be correct; but fromia review of the manner in which the results of the experiments to which L allude were examined. This [ decline, however, as an in- vidious task, unless urged to it by Mr. J. Davy, referring rather to the brief observations, which I, have occasionally offered on some of these experiments... Nor should 1 pro- bably even have. used this expression, had it not appeared to me called for by the tone, which has been, assumed m this controversy, and the manner in which it has been cons ducted. If Mr. J: Davy will look back on its commence- ment, he will find, I believe, my first paper written witha degree of candour, to which it is not in his power to make a'single objection. It was impossibie, if an opinion were at ~ all to be called in question, to have done so with more calm= ness and forbearance.’ Mr. J. Davy thought proper to take upthe controversy in a very different spirit and style, and rendered. it necessary for me sometimes to introduce eremark, which I should otherwise have avoided, - / ~ NATURE OF OXIMUREATIC, AEDs rae) &4 &S Of the other’ parts.of Mr. J. Davy’s. communication £ may avoid, tf believe, taking any notice. He has prefixed a kind of view of the progress of this discussion; id which are - muclrrépetition of what has been already replied to, and misstatements; which to those-who have attended: to. the question it cannot be necessary to obviate,’ I shall merely give one’ example of this, and dismiss‘a subject sufficiently - irksome,’ Mr. J. Davy has found, that, when amixture of {nance of a carbonic oxide, hidrogen, and oximuriatie: gasses): is. ins oa flamed ‘by: the electric spark, two measures out of ten of the fag carbonic oxide disappear ; and this, he says, 1*¢ consider ii’ my last’ conimunication as a demonstration, that oxis - qufiatic gas isa-compound of ‘an unknown basis and oxi- gen”. There isnot a sentencein that communication of mine, that will fairly admit of sach am interpretation; nor should I have’ thought! df*resting any demonstration on so:narrow a basis. I’ consideréd’the fact established by my own experi- ments, that there is a-total or nearly a total conversion’ of carboni¢ oxide into carbonic acid, as such a demonstration, I have farther considered this partial: conversion of car- bonie oxide inte carbonic acid’in Mr. J. Davy’s experi~ ment, as acon yfirmation toa certain extent of my results; and T pointed out to him a very. sufficient reason,! why its sue- cess had not been ‘more complete—-his -having. diminished: - the proportion’of; hidrogen to less thanvongshalf of that which I had employed. It is not more necessary perhaps totake notice of his’ remarks with regard ‘to’ the action’ of , oxiniuriatic gas on carburetted hidrogen. . He must have Mr. J. Davy kriown of ‘the difference of opinion, which prevails among ne chemists with regard to the carburetted hidrogen gasses, and. carburetted of course, in giving-an account “of any experiments upon en he. ‘them, he ought to have mentioned. what particular gas he employed.’ ‘The gas from humid charcoal has been regarded. as a variety of carburetted hidrogen, it is the one even to: which the name was first given, and to which itis still applied;, and though different opinions exist with regard to its con- stitution, I could not know what opinion Mr. J. Davy held with regard to it, or what he considered as exclusively carburetted hidrogen. The subject however is one of little : os cihalaniad and my observations with regard to the one gas will 834 | MATURE OF OXIMURIATIE. ACID. ‘will still, 1 believe, hold just with regard to the other, not would there be any difficulty in showing the imperfections of Mr. J. Davy’s experiment. Mr. Davy’s The question with regard to the general merits of the sub- pespaaec of ject, leonceive now tobeat rest. Mr. Davy’s opinion, which hypothencal was first held out as a genuine theory, admitting-of no doubt snd unproved. as being a simple expression of facts, has been shown to be a hypothetical explanation of phenomena: And ds an hypo- thesis not a single provf has been given of its truth, or no fact has been brought forward, exclusively explained by its or explaived with more probability than by the opposite hy- pothesis: It requires in its adaptation to the phenomena more multiplied and complicated assumptions, and it is at variance with the most strict and extensive analogies. Mr. Murray’s Lam pleased to find my opinion on this point sanctioned, areeane to by that of Berthollet, and, of Gay-Lussae and Thenard. that of Ber- ‘That by, the latter chemists is of too great a length to per-) Toe en permit me to introduce the quotation. 1 therefore refer to _Thenard, their memoir*. - Berthollet, in a report.on their researches, has given a more condensed view, equally clear and candid,: his epinion cannot be received without imterest by chemists, and you may therefore perhaps find room for the insertion of it. After remarking, that Gay-Lussac and Thenard had: concluded, from their experiments, that oximuriatic acid gas may be aysimple substance, and that all the pheno-, . mena it exhibits may ve explained ov that hypothesis, but thatthey had preferred the common hypothesis, as-ex-; plaining them still. better, a preference, they..continue, to, _ give notwithstanding the other idea has wines ee by ; Mr. Davy; Berthollet adds, Berthollet’s ‘In fact, to consider the oxigenized. see gas as a Gn Does simple substance, we must suppose, that common muriatic hypothesis; acid is a compound of hidrogen and oxigenized. muriatic. acid; and that the metallic muriates) are of a nature en-- tirely diferent not only from other metallic: salts, from these very muriates themselves dissolved in water, We: | must suppose, that lime and magnesia give out oxigen, the existence of which in them is supported by certain experi- ments, according to another hypothesis, to combine i in the # Recherches Piissiconaiumntgues 2d, p. 165. , metallic NATURE OF OXIMURIATIC ACID. "x qs & metallic state with oxigenized .muriatic gas ; and that this gas combines with the oxigen, which the water gives up to it, to pass to the hyperoxigenized state: and these supposi- tions are not sufficient to explain every thing. “In the other hypothesis, that isto say, admitting that on the former hy pothesis 5 oxigen is capable of combining with muriatic acid, as it-is with metals, and with all combustible substances, all the explanations‘are natural, and perfectly analogous with those given of other facts, in which oxigen is transferred from one substance to another. Only the new observations show, _ that, to effect the change of oxigenized muriatic gas into . mufriatic gas, it is necessary fer the latter to be in a situa~ tion to receive the quantity of water necessary to its consti= tution; which agrees with the force of its if inn which is very great in muriatie acid. Beby. an “It may not be useless to remark, that, when we discuss and on hype- the ‘nature of substances, the mode of their combination, oh 5 aaa and the changes that may take place in the elements that ; ba? into their composition, it is easy to multiply bypothe- + but those that are best supported by analogy, and: re- pe the fewest suppositions to connect them with the facts, so that the mind readily embraces their relation to them, should be adopted; still however not confounding their ap~ plications with the facts themselves confirmed by weight and ‘measure, or with the inductions that Mnmiedi ately flow from these*.” ai A few months ago I chained a train of experimental New experi _ investigation, different from that which I have hitherto pro- ear rie Sw secuted, which promised to be decisive with regard. to these | hypotheses, The results of the experiments I have performed have atcordingly been such as:appear to me to establish the truth of the common opinion. An account of these will, with your permission, form a communication for the suc- _ ceeding number of your Journal. ) I am, with much respect, Edinburgh, 17th Oct. Your most obedient servant, ee 18 JOHN MURRAY. * The quotation in Mr. Murray’s paper was in, the original, French : _ but for the sake of those of our readers, to whom that language is not sufficiently famitias, it is here given in English, . C. A XVIL XVI. METEOROLOGICAL JOURNAL. ssa dialeeat TEMPERATURE. t0th hice Ocr: Cost OC Or B® 09 2D = NAMNM “N.B. The observations in’ each line of the Table apply to a period of twenty- four hours, beginning at'g A.M. on the day indicated:in the first column. A dash | denotes, that the result is included im the next following observation. NOTES, METEOROLOGICAL JOURNAL. | 287 NOTES. Ninth Month, 9. Before sunset, after a serene day, cirrus clouds, pointing down- ward, from the W. 11. Cirro, cirrocumulus, some dry haze: wind westerly by night, scarce seusible. 14. Cirri and haze in the evening twilight of a bright orange ce< Jour. 15. Much wind: ‘clear. 16. a. m. overcast : p.m. clear: twilight duller, with - cirrostratus. 17. Much wind: very clear sky. 18. As yesterday: evening twilight luminous, orange, surmounted with rose colour, the latter. somewhet in converging - streaks, 19. Morning twilight obscure, with dense cirri: much dew : wind, a.m. N. EB... Thunder clouds at different heights, some.of which moved from the S. E. There were clouds throughout the night, with lightning. 20. Wind a. m.N.E. Thun. der clouds again, which grouped; and passed about 2 p.m, to the W. with a few drops: ‘nimbi, with a faint bow in the distance: evening cloudy, with two strata: wind S.E.: much lightning in the 8.W. 21, a.m. Cloudy. Rain, with distant ‘thimder at one and two p-m.: Nimbi and cumulostratus: faint bow. 29. a. m. Over- cast. Wind veered to N. W., apparently by E. Cuwri, in lines from N. E. to S. Ww. 23. a.m, Wind fresh from S. W., with rain: p.m. fair, with various modifications ‘of cloud, which were finely coloured at sunset in the east. 24. a.m. Clear: much dew: fair day, but with clouds indicating rain: twilight milky, with.a blnsh of red : the. moon disappeared carly, behind cirrostratus clouds, and it rained heavily in the night. 25. Cloudy and windy, with rain. ‘96. a.m.°Cirrus with cumulus: p- m. show- srs. 27. Windy: wet. 28. a.m.-Misty: p im. showers, cvrostraius, and a blush on thetwilight. oy. Evening, lightning: wet night. go. Lunar halo. Tenth month, 1..a.m. Wind §. E. showery. 9..A little before sunrise I observed a stratus in the marshes to the S.E., very ne: rly resembling a sheet of water; one which was seen frum this village, in similar circumstances, about two weeks since, was actu- ally taken by several persons for an extensive inundation. In the aft: rnoon, large ele- vated cirri and cirrostiati rapidly passing at sunsct from red to gray; indicated a renewal, of the wet weath-r. 3. Misty morning, with cirrostratus above: very wet, p-m. 4. Much wind: cloudy night. 5, Squally. 6. a.m. Cloudy, much wind: evening calm; large cirri and cirrostrati, with a blush on the twilight: abright blue meteorin the N. W.: wet night. 7. Cloudy, with a gale of wind, 8. Fair. RESULTS. Barometer: highest observation 30-19 inches ; lowest 28-86 inches; range 3:33 inches: ' Mean of the period 29-736 iuches. } Thermometer: highest observation 80°; lowest 39°; range 41°. 3 : Meau of the period 57:°85°. : Evaporation. 3°93 Inches. Rain 2°39 inches. a From the full moon of last period to the new moon of the present, easterly breezes “with clear days, and the stratus by might. Evaporation went on increasing as the, wind “became stronger: dew fell in plenty, and the small meteors, called shooting stars, were @bundant. The latter half of the present period brought the accustomed compensa- tion, in rain from the westward : the approach of this was perceptible for several days beforehand; and the ground being dry, it was attended at the beginning with some mischanges of electricity from the clouds. Pay Several persons, imagiuing they perceived something extraordinary in the weather, have enquired, whether the present comet could have any influence upon the seasons, At would be'idleito.reason upon its power without proof of itseffects; and these, again, must he proved to extend, at least. overthe whole northern hemisphere; for which a _ Corner of our little islasd is no adequate standard. jt seems within the limits of pos- sible conjecture to'say, that comets may induce some change in the atmosphere of the | raha by changing the state of the ether (if there be any such medinm,) interposed between these and the sun; or by affecting the production of luminous matter on the ‘surface of ‘the sun itself. “A comet approaching near to a planet would aiso dicturh the atmosphere of the latter by the mere effect of its attraction: but we have a plauet ‘attendant on the Earth, which is doing this every day, and we are stili unprepared duly to appreciate its power. Comets are, therefore, at present, ont of the province of the meteorologist. ee: ; L. HOWARD, Poaistow, Tenth Mo. 16, 1811. tS <>) iS 3) Crystallizable compound of pheephoric acid and poty ash. its properties. Uncrystalliza- ble when neu- tralized. A superphos- phate of pot- ash. SUPERPHOSPHATE OF POTASH. i XVII. EGiertascs on the acid Phosphate of Potash: by Mr. / VauQuenin*. Me: Vitalis, secretary to the academy of soieneas, letters, and arts at Rowen; and professor of chemistry in that city, having formed, in the course of his operations, a ‘compound of phosphoric acid and potash, each extremely pure; and having obtained, by suitable evaporation, a perfectly crys- tallized salt; presumed that other chemists, who have all announced the uncrystallizability of phosphate of potash, were deceived, i Too modest to take on himself to contradict what had been said on this head by the ablest chemists, he sent mea small quantity of the salt, that 1 might examine it, and give him my opinion of it. The isllmin are the results of my researches. 1. This salt is very white, crystallized in prisms with four equal sides, and terminated by pyramids with four faces core responding to the sides of the prism. : 2, It has a very sour taste, and powerfully reddens i me » fusron of litmus. It is not alterable by the air. 3. With lime-water it throws down a copious, white, floce culent, and as it were gelatinous precipitate. 4, Caustic potash evolves from it no ammonia. 5. It forms a copious precipitate with spiatien of mufiate — of platina. 6. It givesout no phosphorus by the action of heat, but it — melts into a clear glass, which crystallizes and becomes opake | en cooling, 7., After having been thus melted, it dies not dissolve in water so easily as before. 8. A portion of this salt having been saturated with pot- ash, and subjected to spontaneous evaporation, did not crys- tallize: jt was reduced to a kind of viscous liquor, resem- bling a solution of gum, From these experiments it evidently follows, that the salt — in question is an aeid phosphate of potash; consequently, ® Ann. dé Chim. vo}. LXXIV, April, 1810, p. 96. that SCIENTIFIC NEWS. _ 239 that what chemists have said of the common phosphate of potash is not affected by the properties it exhibits: and that Mr. Vitalis has enriched chemistry with a new species of salt, to be placed in the class, already very numerous, of _ these substances, SCIENTIFIC NEWS. Se eee p A Card has been transmitted to the subseribers to the Lectures at Scientific Institution, Princes’ street, Cavendish square, “riipia agg announcing the commencement of the annual Lectures at - ‘ that Establishment, on Tuesday the 19th of November. The arrangement embraces the following subjects: A popular course of twelve Lectures, on the most interest~ ing branches of Experimental Science, by Mr. George “Singer; a course on the Philosophy of the Mechanic Arts, - by Mr, E, Lydiatt: and a course of twelye Lectures on Chemistry, by Mr. George Singer, ; cee ene Surry Institution, Blackfriars Bridge. The annual courses of Lectures at this Institution will pectures on be delivered in the following order, viz. natural philo- _1, On the Philosophy of Physics, by I. M. Good, Esq. 2ohY? Pe *F.R.S., Mem. Am. Phil. S,, and F.L.S. of Philadelphia ; and belles tet- tocommence on Friday, Nov. 22, and be continued on each aie succeeding Friday. 2. On the Belles Lettres, by Edward Quin, Esq. to commence on Tuesday the 26th Nov., and be continued on - each succeeding Tuesday. _ $. On the Chemical Phenomena of Nature and Art, by Fred. Accum, Esq., M,R.1. A., F.L.S.; to commence -_earlyin 1812. : 4. On Music, by W. Crotch, Mus. D., Professor of Music in the University of Oxford; to commence early in 1812, + Mr. 240 Lectures on manufactures. Mathematical ‘Papers in the Ladies” Diasy, Parkinson's Organic Ree jams, SCIENTIFIC, NEWS. Mh, Clennel, Conductor of the ‘* new Agricultural and © ~ Commercial Magazine, or General, Depository of Arts, Manufuetures, and Commeree’, commences: a conrse of six weekly Lectures on Manufactures, at Stratford, near Bow, on the Ist of November. Iron, coal, wool, cotton, Iinen, and silk, with the various arts and manufactures arising out-of or connected. with them, willform the leading. topics of these discourses, which are intended to be amus- ing, as well as instructive, ae oe Mr. T. Leybourn, of the Royal Military College, Editor of the Mathematical Repository, intends to publish by subscription a Collection of all the Mathematical Questions, and their Answers, which have appeared in the Almanack called the Ladies’ Diary, from its commencement in 1704 to the present time. The editor of the Diary (Dr. Charles Hutton) published a similar work in 1773, but comprehend- ing both its mathematical and poetical parts down to that pe- yiod. Mr. Leyburn’s publication will comprehend only the mathematical part, and, with Dr. Hutton’s permission, will contain all the valuable additions given in his edition, as far as it extends. He also hopes to be able to give other addi- tions by the assistance of some of the ingenious mathema- ticians, who have for a number of years past Pepemsnted to the Mathematical Repository, The work will he printed in 8vo, and will be published in half volumes, one of which will appear every three months. The diagrams will be printed in the text, from figures cut in wood. It will be put to press as soon as such a number of subscribers can be obtained, as shall give the editor a prospect of being indemnified for the expense, which must attend its publication. rE The 3d vol. of Mr. Parkinson’s Organic Remains of a fupiget World ts promised in the course of Nematns m4 w% “JOURNAL NATURAL PHILOSOPHY, CHEMISTRY, . \ AND — THE ARTS. Se eee DECEMBER, 1811. ARTICLE I. Description of a Spire of a new Construction, at Edgeworths« town, combining the Advantages of Cheapness, Elegance, and Durability. In a Leiter from RicHarp LovELL Epcewortn, Esq., F.R.S. M.R. 1A. Sc. To W. NICHOLSON, Esq. SIR, EDGEWORTHSTOWN, IRELAND, Sept. the 22nd, 1811. I Have lately erected a spire of a new construction on the Spire of a new tower of the church of Edgeworthstown, and, as the at- "ion ‘tempt has succeeded, I hope an account of it will be ace town. “ceptable to your readers. ‘ My object was to lessen the expense, and to facilitate the “means of ornamenting places of public worship. This spire is fifty feet high from the base to the star by Height of the ~ which it is crowned. See Plate VII, fig. 1, which is a sec- Pit: tion of the tower, the spire, and part of the machinery. The Mode of its “spire was made withinside of the tower, and, when com- rn * pletely finished, was drawn up in a few minutes by ma- chinery, and placed on the tower, where it now stands. It * Consists of a skeleton of hamwered English iron, covered * Vou, XXX. No, 139,~—Dec. 1811. R with 242 The skeleton. Manner in which the parts were fit- Sed together. The bask. SPIRE ON A NEW CONSTRUCTION, with strong Welsh slates, capped where they meet on the skeleton by large copper beading, which, with the slates, is fastened to the skeleton by copper bands and cramps. The whole is well painted, and covered with sand, so as toimitate stone. " » The. skeleton was formed of eight bars of iron, ,45 feet long, 2inches and + broad, and 3 of an inch thick. . These dimensions were chosen because they are those of common bars, that are sold by ironmongers.. These bars axe usually 14 or fifteen feet long, and I had them welded in a common forge to the length that was requisite. Eight of these were -disposed octagonally upon a base, fig. 3, about 9 feet in dia- meter, which is nearly the diameter of the tower. It was m: ade of bar iron an inch square. "Before the spire was put together in the tower, the batts were previously fitted on the ground, not perpendicularly, but lyiug sideways, so that each bar could be easily reached bythe workinen. With this view I took advantage of asaw- _pit, which permitted half) the, base to he below the ground, while the apex, .or point. of: the spire; was supported by a bench, on the surface of the ground. This enabled me to assemble and, fit the bars which were necessary for cross. braces, and to combine the bars accurately round the spindle of the weathercock, and to secure them by a ring of iron. ‘ The base aboye mentioned, + 3, consisted of four fines of iron, fattened where they crossed each other, with a hole through the middle‘of each, that received a bolt to bind _them, together. The ends of each of these bars were so Angularbracege \ Beside these diametrical supports th are four bars, formed, with cheeks, as to permit the bars, that composed the spire, to lodge within them, and to be fastened tothem | by.screw bolts. Light flat. bars d, d, d, held by the same | serew bolts, were placed between the bars of the. spire, to keep them at due distances from each other, thus forming a species of diaphragm, fig. 3, where A represents the dia- § phragm resembling the rudiments of a spider’s web; cec, 9 &c, the cheeks of each transverse bar of the diaphragm, and 4b b the bolts, which connect them with, the legs) of the § spire. B By SPIRE ON A NEW CONSTRUCTION. Q45 BB, fig. 6, 20 feet long, placed obliquely from the bottom of one bar to the opposite bar, to which they are rermaing i? screw bolts, thus forming angular braces. The spindle of the peers tlier dest rises § feet above the apex ~~ of ‘the spire, and, ‘passing downward through the junction “of ‘the bars, it is inserted into a solid diaphragm under and ‘epaitist which it is keyed by a forelock. Beside this diaphragm, and that which forms the base of Diaphragma, ‘the’’spiré; there are three others D D D, fig. 6, of a.con- struction ‘similar to that of the lowest dieephvaeti, placed at “equal distances froin each other.’ It is to be observed, that thecheeks or ends‘of the three upper diaphragms project ‘beyond the upright legs of the spire, to assist in supporting the slates; but the cheeks of the lower diaphragm take in “not more than two inches of the feet of the bars of the spire; “which feet, as may'be'seen at fig. 4, are considerably broader ‘than the rest of the bars. | At B, fig.'4, a tenon is formed at the heel of the foot of Feet of the “each bar, whichis to receive a key, or forelock, to fasten the bar spire tothe tower, after it has been raised to its place. - To raise and guide this spire, a pedestal, the plan and Carriage for section of which are seen at fig. 2, and 6, was constructed, ™ing the ‘It consists of a top and base, Bia formed of four pieces of — deal 6 inches square, and of eight jambs, or uprights, of the same breadth and thickness, and 10 feet high, morticed into the base and top, so as to stand. nearly under the eight legs of the spive'when it is raised upon it.. See fig. 6, where J IJ show the position of these uprights, The uprights “are strengthened by braces, 0 6.60, so as to prevent them from racking, or moving obliquely. The pedestal was fur- “nished with eight wheels 6 inches in diameter, at its upper * corners; and with eight similar wheels at its lower corners; “as in the plan, fig. 2, and in the section, fig. 6, w w. + Yo facilitate and guide the movement of this pedestal up- “iwards, the tower was lined at each corner with thin planks, 4 PP, fig. 1, fastened to the walls perpendicularly, and ad- Eiheted with care. Against these planks the wheels of the pe- * destal inoved upwards with little friction, keeping the spire perpendicular in its ascent, « . R2 Wher sk, mo . « O44 SPIRE) ON A NEW CONSTRUCTION. « When this pedestal wae adjusted, the skeletonsimblel ba been fitted on the grouad, was:taken to. pieces. it &2. det Haine in The base, or lower diaphragm, upon which the Ho had which the es wae been adjusted, was placed.and fastened in a temporary man- put together, mer on,the pedestal. ‘The long bars were drawn up, one by jone,.into, the tower above the platform; and their feet. were inserted into the cheeks of the base, or lower diaphragm; perm: where:they were secured by. bolts, as before described. "The ui _other, diaphragms, and the iron cross braces, were then in- -serted between the iron bars, and firmly bolted to them. *. Covered with «, By. the favour of Messrs. Worthington and Co. of Pen- slates. rhyn, Lwas furnished with excellent slates of dimensions sufficiently large to cover.the spaces between the bars, which .at the base were nearly 4 feet wide, The slates were 2 feet -6 inches high, and nearly an inch thick*. These slates were -sawed to fit upon the ribs where they met, and they were rabbeted with the saw and chissel to Jap over each other, 90 i as to keep out water. They were so well joined by these means as to present one even surface, on which the courses of the. slates scarcely appeared. through; the paint. These joints might by addional: paint have been entirely concealed, -but'their appearance was thought. to be advantageous, as it gave an idea of solidity; from its nearer resemblance to stone. "Mode of fas-* It remains to show how the slates were wi al to the tening the ni ‘}ron upon which they were placed. For this purpose grooves about one quarter of, an inch deep were sawed in the upper surface of each slaté, parallel to the bars, and at the dis- tance of nearly two inches from them. A copper capping, — Best saws for’. The slates were first cut with sand, and such sawsas are used for cutting slates, cutting marble, Though this is the method followed at Penrhyn, 1 found ‘ common saws of a erates size, such as are usually sofd for half a ln far more expeditious. In cutting the grooves, that receive the copper capping, I employed . thin saws with a wooden back, which was held in the hand of the work- . men. “To make these saws, I cut the blade of small saws into four parts _ with common tinkers sheers, Air holes cut. “it holes in form of a quatre feuille were made near the top of the in them, spire, to permit the circulation of air, and they{serve also to facilitate the _ applic ation ef @ moveable seaffold, whenever the Spire requires new painting. , 3 early SPIRE ON A NEW CONSTRUCTION. Q45 ¢nearly' semicirctlar,: and about four inches in diameter}'was Mode of fase splaced so as to cover'the joints of the slates, where they met “abe, the -the-bars, sinking into the grooves ‘which: were justisufi- ciently wide to receive the copper.. |The copper ‘by its \ shape and elasticity caught in the grooves, so.as to, form, when painted, a covering perfectly impervious to rain and snow. go) 'Pe fasten these copper caps and the slates to the skeleton \.of the spire, a contrivance was adopted,’ which: requirés ‘$ome detail to become intelligible. The géneral idéa was to fasten the capping and the slates from within, so as to leave no holes to be stopped on the outside by putty or paint. Fig. 7 is asectionof theslates on alargerscale than that of the spire, where they join on the rib; of the copper’ cap- ping; and of a collar, or band, by which they are connected /withan iron cramp, that passes round the inside of theirib, -and, hooking into: the collar or band, is wedged within, "against the inside of the rib. In looking. at this section, -eare must be taken to distinguish the cirenlar edge. of, the copper capping from the ace of the band or.collar. The )» band, as maybe seen in the dxteuides’ is twice as thick as the cappiug. In this section of all these parts, as connected together, C is the copper capping; S S, the band or collar ; Hs H, the cramp, or holdfast; and W, the wedge. ‘The whole of this apparatus for fastening the slates suc- séendad to my wishes: it was easily executed by common workmen; the parts were easily put together; and, when eer adapted to their several places, they held the slates and their “gapping firmly upon the bars, at the same time produemg a vety good effect by raising a bo! d and ornamental moulding, edie or torus, fig. 7, on every angle of the spire. Its scarcely mecessary to.add, that part of the lower corner of each slate “was cut away at A to permit the cramps to pass through, ~and»to embrace the iron rib; and that the ends of the dia- --phragais were permitted to extend beyond the outward sur- ‘face of the nibs, to support the perpendicular. pressure of _the slates. Such slates as were not thus supported rested ee the rabbets of those that were beneath them. . The machinery, .by which the spire, when it was thus fi- Description of DF ciated, was drawn up, must new be described, the machinery for raising the qe Py ‘ The spire. ‘946 SPIRE ON A NEW CONSTRUCTION. The pedestal. | “Fhe plan of the pedestal, the top and bottom of which ‘are similar, is represented at fig. 2, where 1, 2,3, 4, &es are - the bottoms of the eight jambs, or uprights, of the amen “and W W, &c. the wheels, or ‘rollers.:0 A section of thé pedestal, fig. 6, is par in nthe pate of “the section of the tower, i pel b b, cross braces. Wore The spire. 'D D the base, ‘or lower diaphragm, of the spire, resting on the pedestal, to which it is attached by four bolts (of which two only are seen in the section) withoforelocks, FoF, “so as to be easily detached from eachother, 9:)).. ecko! | LLUL, the legs of the mean Hof olf aun] | DD, the diaphragms. eis 0 G8, the spindle of the elle passing though the apex of the spire. '+€, a conical collar, or ring, enclosing the me of iiehi A shoulder is formed on the spindle, and rests onthis ring ; and as the collar, or ring, projects a little above the tops: of the legs of the spire, it could be forced downwards, till the ~ shoulder touches the tops of all the legs, which are cut even, ‘and horizontal at top, so as to permit ‘the collar, the legs of “the spire, and ‘the spindle, to be ‘firmly bound ‘tocetlyer. This is done by means of a mortice, of keyhole, formed in the lower part of the spindle which passes through the small - solid diaphragm d, against which it is wedged 7 the fore- “Tock fi ileliahatia Method of fas- The heels of all the bars, witle the tenon at B, fig. 4, bc ’ (where it is drawn upon a larger scale) pass through consols, place onthe “XX, fig. 1, of stone capped with cast iron, that project are? ‘from the wall of the tower. The iron cappings of ‘these consols, fig. 8, are made of cast iron, and have apertures left in them, through which the heels of the bars, whieh form the spire, may pass. When they have all been raised through ‘the consols, eight washers, fig. 9, witha mortice, m, in the centre of each of them, are laid upon the corisols, and, the spire being allowed to descend, the tenons inthe heels of the bars fall into the moftices, and rest upon the consols, and eight other washers are placed upon the tenons, under the eahMne beneath which they are keyed by BAPE, T T, fig. 1, the walls of the tower. » 42 WW, | SPIRE-ON A NEW CONSTRUCTION. 949 WoW; the’horizontal windlasses, over which two of the ropes were coiled, once round, with weights hung to them,’ | rr; pullies, over which the ropes passed. Of these there were ten sets, with weights, to counterpoise the pedestal and spire. < Ah, handspikes. Four men were sufficient to work both the windlagses; The spire and on the 19th of, this month, before a very respectable teas UR, concourse of spectators, the spire was drawn up without difficulty or noise in eighteen, minutes, It was soon de- tached from its. pedestal, and fixed in its proper place ¢ on.the consols, with the washers and keys, er forelocks. A sufficient number of the counterbalancing weights: were cut off by sheers; and the men, who had worked the wind- lasses, descended upon the pedestal to the bottom of. the tower. ‘y ; . A plumbline was iae, from rin ton of the. spire siilip placed truly side, by which it was properly adjusted; and by a few Pefpendicular, wedges it was placed perfectly upright. To add security to the connexion between the spire and and farther se- _ the tower, iron cramps of 7 or 8 feet long were hooked into C¥"? the mortices, which had served to join the legs of the spire to the pedestal, and were firmly fastened to the walls of the tower by proper holdfasts: so that, though the spire and tower may be blown down together, it is scarcely possible, that they can be severed by the violence of any storm. The cost of this spire has not yet been entirely ascertained, Expense of the but it does not. exceed one hundred and fifty guineas, Aspire spire, - of the same dimensions, built of Portland stone, would, in this country, cost at least six times this sum, and if it were _, formed of the limestone of the country, it would cost four or - five hundred pounds. I was this day, September the 22nd, enabled to deter- _ mine, whether strong wind had any seusible effect on the _ spire, as its spindle happens.to coincide with a vertical wire of a transit.instrument in my observatory. The violence of +a sudden squall did not seem in the least to affect it, . I have therefore reason to hope, that it will remain undis- : iidilbed by future storms: and, as a thunderstorm passed over this place the night before, I trust, that the conductor, tae ¥ which e 248. ON PREPARATIONS OF..GOLD.. which has been,attached to the iron legs, wall secure'the spite isi the effects of lightning, . i ihieh aah 15%, I am, Sir, Bie PGi). 4, Your obedient servant, © RICHARD LOVELL EDGEWORTH. It has occurred to me since the spire was finished, that, instead of a temporary wooden pedestal, an iron permanent pedestal might be substituted, which might bé formed by a continuation of the Jegs of the spire. At the base of this pedestal, if it were flout necessary, a brick arch might be turned on the lowest diaphragm. “This would add weight, and consequently solidity to the mass. This pedes- tal must be connected with the tower by holdfasts and wedges, I mention this, not because [ find any inconvenience in wht yt have executed, but to communicate to the public et that has occurred to me on this subject, i ae Experiments on some Preparations of pene by sg VAvQUELIN®. Preparations of ~ Suor Dr. Chrestien, of Montpellier, sericea the ef gold employed fects he had obtained from the use of preparations of gold medicinally, in syphilitic and lymphatic complaints; and remarked, ‘that ‘these effects were never attended with the ill consequences, — to which mercurial preparations often give nse, other eg cians have begun to make use of them. "The forms in which gold has hitherto been employed are, 1, in a state of minute division 2, the muriate: 3, the oxide precipitated from a solution of gold by potash: 4, the precipitate thrown down by metallic tin from the mu-_ yiatic solution of gold. # Annal. de.Chim. vol. LX XVII, p. 921. There ON PREPARATIONS OF GOLD. , 249° There is: some difficulty in obtaining these preparations Difficult to ob- constantly in the, same state; and one of the principal ob- oer une jects in the art of physic being precisely this constancy in _ the mature of medicines, it appeared to me of some utility _ to examine these preparations, and'to describe with accuracy the processes pi adapted for obtaining them. Sxct. 1, Of the quality and quantity of nitromuriatic acid most suitable for dissolving Gold. It was formerly the practice, to compose nitromuriatic Nitromuriatic acid of two parts of nitric and one of muriatic, by weight. ig fa ae es But on considering, that gold requires only a very small tric, dissolve 1 portion of oxigen for its solution, and that the nitric acid in P- of gold. the process in question answers this purpose alone, I con- ‘eloded, that the same purpose would be obtained, if an . aqua regia were composed of the two acids in opposite pro- portions to those hitherto directed, In fact, three parts of nitromuriatic acid thus made were sufficient to dissolve one part of fine gold, while at least four made- in the old way were required, A proof.of the small quantity of oxigen, that combines But little oxi- with Sold at the moment of its solution may be found in the Cheol. very small quantity of nitrous gas evolved: beside which there is reason to presume, that some portion of this gas js produced by the action that takes placé between the two acids, since some oximuriatie acid is evolyed }:kewise - The solution of gold, when duly evaporated, crystallizes The solution in yellow prisins, the figure of which, IL belieye, has never Arystallizes, yet been ascertained with precision. The evaporation of the solution must be conducted with but is partly great caution, otherwise part of the salt will be decomposed, oh pen and | the, gold will reappear in its natural state, in the form care. of aul, scules. The solution of muriate of it comports teers with the Action of fixed alkalis ina. manner different from that of other metals ; @/kalis on it. most of which, it is well kuown, aré cympletely. precipitated _by them in the state of oxide. . ,Potash, soda, barytes, and lime, do not render the solu= Do net preci- -tiop of gold in the least turbid, at common temperatures. Pilate it It only acquires avery deep red colour with potash and ion soda * B50 ‘ON PREPARATIONS OF GOLD. soda, nearly like that of Stahl’s alkaline martial tincture. No change in the Iimpidity: of. aheke mixtures takes place on standing. Hyu3 i Barytes and lime do not wee the same colour‘in the solution of gold, no doubt-on account of the eran eeney of water employed in their solution? unless assisted Uf after the acid of the solution of gold has “dt com-~ by heat, pletely saturated by potash, the mixture be heated, a red . substance separates ina yery bulky flocculent form, much resembling in appearance oxide of irén at a maxiaium. - Fiosipitate If an excess of caustic alkali, even though) very trifling, with excéss of be put into the mixture, and it be boiled, the bulk of the — precipitate will diminish greatly, and it will appear of a brown colour, when seen in a body; though it is in reality blue, for the particles of matter dinbeided inthe liquor, which of itself és slightly yellows make it appear green*. Themen- . Loe liquid, from which [I had precipitated the matter struum stillree abovementioned by means of potash, was- colourless; but, tained some “ae soon as it was saturated with muriatic acid, it suddenly ae assumed a yellow hue, like that of the common solution of gold, and sulphate of iron threw down metallic tery tom BEL pak The precip All the washings of the precipitate, to the last, gave signs tateslightly of the presence of gold; which seenis to indicate, that this fohagle: matter is slightly shee? in water, The last Ewahiidaleit how- ever contained less than the first. Acivilletaat ‘When the liquors contain a certain quantity’ of sta the phate of iron precipitate formed in them by sulphate ‘of iron’ presently Pr ee ely assumed a brown colour; but when they contain only a portions, _ ‘little of this metal, no precipitate is formed immediately, the liquid only becoming of a fine transparent indigo blue. At length however, a black powder is deposited, leaving the liquid colourless. This observation seems to prove, that when gold is in a Colour of gold. : pau s : ©" state of minute division, it appears blue; and that it as- * Two things are here taken for granted; that the precipitate is ho- mogeneous,,and that the suspended particles are precisely the same with it. From the next parayraph too it would appear, that the “slightly yeliow” liquid is colourless, Cc. f sumes ON PREPARATIONS OF GOLD. 25} umes its natural colour only from the union of ‘a certain number of its particles, This would explain, Ist, why a very thin leaf of vold, perforated with minute holes, when held between the eye and the light appears green; because the blue colour of the most minutely divided particles mixes with the yellow of ‘those that are less so: 2dly, why, when to asomewhat concen~ trated solution of gold sulphate of iron 1s added in suffici- “ent qnantity to reduce the whole of the gold, the liquid is of a fine green; because the yellow célolit of the parti- ‘cles of gold united in little masses combines in some mea~- sure with the blue of those that are not yet united: and _Sdly, why, in proportion as the former fall down, the liquid (gradually changes to a pure blue; which it continues till ‘the whole is precipitated. Hence it is probable, that the Purple powder ‘precipitate of Cassius does not consist wholly of metallic of Cassius. gold, but is rather a mixture of oxide of gold, oxide of tin, ‘and alittle metallic gold. Carbonate of potash also added to a solution of gold does Action of car. ‘not effect its precipitation, but only produces an efferves- bomate Caer ‘cence. At the expiration of thirty hours the solution be- lution. comes turbid, without any thing separating; and it assumes ‘a very rich red colour, in sap desig ed as the carbonic acid it so absorbed flies off, ~ On boiling this'mixture a very thick magma is formed of Precipitate on ‘the colour of pale kermes mineral; but this colour is not » Widied altered by ebullition with excess of carbonate, as is the ‘case with caustic potash, which indicates, that the latter has boute action on the precipitate, “When the liquid, from which the red matter was sepa- Gold still inj ‘rated, appeared to have lost its colour, I filtered it, to ob- ‘¢ Hauid, tain the precipitate by itself. The liquid then exhibited ‘only a very slight tint of yellow, whence, and from its taste, which was by no means metallic but simply saline, it might “have been presumed no longer to contain any gold; but this would have been a mistake. In fact a part of the li- “quid, into which I let fall a few drops of muriatic acid, im- “mediately assumed a very decidedly yellow colour; and on “the addition of sulphate of iron it threw down a pretty con- siderable quantity of metallic gold, Th 232 ; ON PREPARATIONS OF GOLD. The examination of this liquid I deferred, till another time, toattend tothe red precipitate formed by the carbons ate of potash inthe solution of gold. The precipi I began by washing this substance with. biting water, tytc examined, taking care to keep each of my washings separate, that I tom more easily satisfy, myself when it no longer contained any thing soluble: but, though I thus used a very large quantity of water in proportion to its bulk,'l was never able to exhaust it; and it appeared to me, that,the last washings Slightly solu- contained nearly as much cold as the first. Hence was led ble in water. ¢ suspect, that the precipitate was slightly soluble in water, and that, by, continuing to wash it, I should perhaps cause ‘Dried. it to’ disappear entirely. In consequence I ceased washing the precipitate, and dried it slowly. It greatly diminished m bulk, which proved, that it contained a large quantity of Its colour. water. Its colour became a great deal deeper, and resem= bled that of dried blood ; but when powdered it was of an eee orange yellow. 7°643 gram. [118 grs] of fine geld, preeipi- thirds of the pitated as mentioned above, furnished only §*414 gr. Baap ott ie [83.7 grs] of red matter: whence it follows, that 2°229 gr. [84°3 grs] of gold at least, or a little less than a third, re mained in the mother-waters, and in the washings. No excessof | Though I employed an excess of carbonate of potash to carbonate in it yrecipitate the solution of gold, the red matter J. obtained when washed, j : i id not contain any sensjble quantity of this salt: for after it was dried, it dissolved entirely in muriatic acid without producing the least effervescence; which proves, that it had been entirely divested of carbonate by the washings, and that the precipitate it formed retained no earbonic acid. Rut itreiained Butit was not the same with respect te muriatic acid; for ore muriatle if was necessary to employ repeated portions of nitric acid, us will be seen below, to deprive the precipitate completely of the muriatie: after this the nitric solution no longer, is forded a precipitate with the nitrate of silver. Probably an The presence of muriatic acid in the first solutions, of this oxide of gold patter in nitric acid led me to suspeet, that it was in the witha little i : Ed ‘ maria, state of muriate of gold wlth excess of oxide; but as: the latter contained no more of this acid, it appeared to me ere probable, that it is simply an oxide habsibine a few _ atoms oxide part of the gold dissolved'in muriatic acid, why do ‘tioned, has very sensibly a styptic metallic taste, which ex- ON PREPARATIONS. OF GOLD. 253 ‘atoms of muriate, notwithstanding the repeated washings it had undergone. ‘But if potash and its carbonate precipitate in the state of Why isnot the precipitate hos 1 i - mogeneous? they not precipitate the whole? and what becomes of the F part left in the liquid, and in what state is it there ? This we shall examine by and by: at present let us de- scribe the properties of oxide of gold. . The oxide of gold, prepared in the manner above-men- Properties of the oxide of gold thus obe cites the secretion of saliva copiously, and for a long time. tained. If it be diluted with water, and blotting paper,*or any other porous combustible substance, be impregnated with it, it -eauses them to burn with scintillation, as gunpowder would “do, A decigramme [1:'544 gr.] of this oxide, ina state of ‘minute division, and shaken for some time in 60 gr. [996-7 grs} of distilled water, was not dissolved, at least entirely: the filtered liquor however, though perfectly clear and colourless, afforded with sulphate of iron a pretty copious blueish pre- “eipitate, which was metallic gold. This proves, that a so- Jution in water had taken place: but as this solution might have arisen from some portions of salt remaining with the oxide for want of sufficient washing, I poured fresh por- ‘tions of water repeatedly on the undissolved portion, and by “the same means as above-mentioned found gold dissolved in them all; though itis true the proportion gradually dimi- nished as the washings were’more numerous. Though I did not dissolve the decigramme of this substance entirely, ap- - parently because the latter portions were not sufficiently ‘divided; I have no doubt. from the little that remained, that | I should at length have dissolved the whole, if 1 had con- tinued my trials. What seems to prove it is, that the last washings, which still gave evident signs of the presence of gold, when tested _ ‘with sulphate of iron, afforded no appearance of the pre- “sence of muriatic acid on adding nitrate of silver. From these experiments we may presume, that potash, Alkalis pre- soda, and their carbonates, precipitate gold from its solu- ee _ tion in the state of oxide; or that, at least, if any muriatic “acid remain in the precipitate, it must be an infinitely small 254. ON PREPARATIONS OF GOLD. - small quantity, when the washings have been: penta with due care. Its medicinai The slight solubility of ‘this oxide, inal its very easy, Ades qualities, composition, must render its action, as an oxigenizing substance, in the animal economy, prompt and certain, Similar to The red oxide of mercury, which has some properties in pipe one common with the oxide of gold, namely those of dissolving mercury, in water and of being easily decomposed,, possesses nearly Oxide of silver Similar. medicinal virtues; and from. analogy we may pie ai ana” conjecture, that oxide of silver also would have the same ie properties. ® | Actionofni- Nitric aeid does not aitaak di oldies er said, aahsis tric acid on : iowide® (a4 be employed. in large quantity, and m a concentrated state. In this it differs greatly from the muriatic acid, which dissolves it immediately. The. nitric solution. of gold has a brown hue; and water throws.down from it a flocculent precipitate, of the same colour as that sivisioned by alkalis. The first portions of nitric acid, that have Been decanted off the same oxide of gold, form a’ precipitate with the solution of silver, after the gold has been thrown down from them by water; but the latter portions are not tilly i which confirms what has been said above, The affinity of the oxide. of gold for, nitric acid. appears very weak, for part separates in,the metallic state by spon- taneous evaporation.. This no doubt is the reason wie ni- tric acid alone cannot dissolve this rata . “Secr. Ul. Examination of the liquor, from which ‘pit has’ been precipitated by jived alkalis. The liquid I have said, that this liquor has no perceptible clout, from which but that it resumes a pretty deep yellow, when muniatic Seen acid is added, and that afterward an addition of sulphate 2 examined, —_ of iron throws down metallic gold from it pretty copiously. Muriate of Having evaporated this liquor by a very gentle heat, Lob- jf potash first tatned at first crystals of pauriate of potash; among which separated, were observable some other crystals of carbonate of potash, then carbon- ate 7nem this salt having been added in excess. The liqnor being decanted from these salts, and evaporeteg anew with the same ON, PREPARATIONS OF GOLD. 955 same; precautions, acquired a, slight yellow tinge, and. at and jastly a length furnished. asalt of the same colour, which had no yellow, salt regular figure. - With this were mixed a few: crystals of ear- bonate of potash. perfectly colourless...The,.coloured salt, being well drained, produced no very decisive effervescence with muriatic. acid, though the colourless; crystals effer- vesced with it briskly; but its solution was not coloured. The coloured crystals, when redissolved in water, yielded a copious precipitate of metallic gold on the addition of sulphate of irou.. The mother-water of these crystals ef- fervesced. with. muriatic acid, and afterward gave a precipi- tate of metallic gold with sulphate of iron. , These experiments seem to prove, that these crystals, as beinga triple. well as their mother-water, are composed of muriate of clea ase gold and muriate of potash united together in the state of a ash. . triple salt; .and that the carbonate of potash isonly mixed with them. | Flence it appears very. probable, that, if a solution of Perhaps this gold, as nearly in the neutral state as possible, were mixed Slt, not preci- rue much. less; abundant, of a different colour, and of a itable by al- with a. sufficient quantity of muriate of potash, alkalis Rais.) would throw down no precipitate from this mixture. . To. prove this, I made the experiment above; but I ob- but the can- tained a precipitate with carbonate of potash: though it is ete expenment different appearance, from that obtained with a solution of pure gold. Its colour was yellow, and its form granular, not flocculent like that of oxide of gold. An examination of this precipitate informed me, that it Precipitate. was. composed of muriate of gold, and muriate of potash _bonate.of potash, if a sufficient quantity of acid to decom- tendered little soluble by the presence of alkali in the li- quor, from which it had been separated. One thing remarkable is, that, after having precipitated a Oxideof gold solution of gold by means of an excess of saturated car- thrown down by an acid. pose the alkaline salt be added to the filtered liquor, a few flocks of oxide of gold will be separated; and afterward, ‘this liquor being filtered, if muriatic acid be added, it will . yield a fresh precipitate by the help of boiling; but the last is a triple salt, similar to that which hae just been men~ “ead * tioned. I 2956 AWALYSIS OF HUMAN BoNngs. Pobably pot- ‘I think the precipitate formed by an acid in the solution neo eam of gold i is to be atcribed to a small quantity of this metal held in solution by carbonate of potash. This effect takes place in a still more remarkable manner witht caustic potash. Method of ob- . From what has been said it is evident, that, to ptecipitate bigest qui: the greatest quantity of oxide of gold ‘possible from its mu- tity of precipi. riatic solution by means of alkalis, we riust, manage so, bc that no useless acid remains in the solution; in order that . less of the triple salt may be formed, on which the alkalis have noaction. This is effected by evaporations to atv aeR very cautiously conducted. The liquor It follows too from what has been said, that the liquors, pa olen ae from which gold has been precipitated by alkalis, should precisa not be thrown away, for they still contain a considerable should notbe quantity of the metal. On this occasion | may relate a curi- thrown away. : . ous anecdote, which shows, that many things are lost some~ times in the arts, and in manufactures, from which advantage — ce Cie might be derived, if we had the requisite knowledge. For as. al many centuries jewellers had been accustomed to throw away as useless the waters, with which they cleaned their work, and thus at least two or three thousand franes were annually Jost in Paris alone. But since T taught them, that these waters contained gold, and showed thet the mode of per ting it, they preserve them carefully. I am at present busy. in examining the nature of the gold preci pitated from its solution by thictalllid tin, which is also employed as a medicine; and as soon as I have finished my investigation I ‘shall lay the result before the penis {of Pharmacy at Paris]. : —————— Hil. Experiments on Human Bones, as a Supplement to the Paper on the Bones of i) Ox: by Messrs. Yourcroy and Vav~ QUELIN*. oo grag sUup= VW HEN in the month of August, 1803, we. published . a to exit our first paper on the existence ‘of magnesia in bones, we — * Journal de Physique, vol. LXX, p. 135, announced ANALYSIS OF HUMAN BONES. 257 announced; that we had not- found any in human bones; in the bones of and thought we might presume the cause.of this difference rn to be the excretion of phosphate of magnesia by the urinary passages’ in) man, while none occurs in the urine of ani- mals. ' However, as we had made only a single experiment in search of this substance, we did not assert pesitively * the ping snl of magnesian earth in these organs. “On occasion of our last publication, in the month of Human bones Sipiner, 1808, on the presence of iron and manganese in conbliripd ox-bones, we thought it necessary to resume with great eare the analysis of human bones, not only with respect to magnesia, but also. of the metals in question. » In; treating these bones in the manner we have men- yielded mage tioned with respect to those of the ox+, we found in them nesia, iron, and manga- be incisicnand iron, and manganese, in the same state.as in the ,.... . jateer. If we may be allowed to padage on the proportions of the put tess of the substances we obtained from human bones, they appeared first, and more tous tovcontain less magnesia, and more iron and manga- tarp ves nese, than the bones of herbivorous quadrupeds. The those of smal] qnantity of the first of these salts agrees with the con- peasrnnede, ‘ tinual discharge of phosphate of magnesia in the human urine, It is well known, that this is not the case with the urine of herbivorous animals: on the other hand, the iron and manganese, ouce entered into the course of the circu- lation, and deposited in the various organs of the animal economy, no longer finding an exit from the body, the quantity of these two substances apparently must increase with age, and from the known nature of food ; so that the blood and bones of an old man ought to contain more iron _and manganese than those of children, as well as of ani- mals, who besides do not live so long as map. Thus the _ proportions with respect te quantity confirmed by our ex _ periments are equally so by known physiological phenomena, Our last researches have shown us traces of alumine.and They contain _silex likewise in human bones. The last exists in the phos- a oo a | #8 Tt appears However to be asserted positively enough in the paper Fe- oe “ferred to. See Journal, vel. Vill, p. 86: C. ‘| See Journal, as above quoted. C, Voie XXX—Dac, 1811. 8 phate Wel! 258 Method of analysis. ANALYSIS OF HUMAN BONES. phate of ammonia resulting from the precipitation of phos- phate of magnesia by volatile ‘alkali. On evaporating to dryness, and slightly calcining the residuum, this earth is obtained of a black colour, and in a fleceulent form; but by calcination at a red heat it assumes all its characteristics. We suspected at first, that the silex and alumine might have been taken np by the phosphoric acid from the stone vessels we used: but we have since satisfied ourselves, by several decisive experiments, that they actually existed in the bones. . * Though we have already given an account of the succes sive operations necessary for obtaining the different substances just mentioned, in the Annalesdu Muséum @ Histoire naturelle for September, 1808, we shall repeat them here, to forma complete whole, and as # guide to thosé who would go throuyh the sane examination. é 1. Let the bones, caletned and powdered, be decomposed ey an equal quantity of sulphuric acid. 2. Dilute the first mixture with twelve parts of distilled -water; pour the whole on a piece of cloth, leave the sul- phate of lime to drain, and wring it out strongly... 3. Filter the liquor through paper, and precipitate it by ammonia; filter it a second time, wash the precipitate, and set the liquor aside, 4. While the precipitate is still wet, treat it with ediphide acid, taking care that the acid isa little in excess: filter afresh, wash the precipitate, and add the liquor to the for- mer: No.3. Repeat this operation, till. the precipitate formed by the ammonia dissolves entirely in the sulphuric acid ; which will show, that it no longer contains any sen- sible quantity of lime. By this series of operations the whole of the lime in the bones will be converted into sulphate of lime, which, being but little soluble, will be separated from the liquor; in which will be found the phosphoric acid, with the sulphates of magnesia, iron, manganese, and alumine, 5. These substances, being separated from the sulphuric acid by ammonia, are to be treated with caustic potash, © which will attract the sulphuric and. phosphoric meets canine the ammonia, and dissolve the alumine. GP recipitate the aluwine ATOR the alkaline sdhittied ff ™ eans. ANALYSIS OF HUMAN BONES. 959 means of muriate of ammonia, wash it, and examine by Method of the usual means whether it be really alumine. maa inca 7. Dry the magnesia, iron, and manganese, from which the phosphoric acid and alumine have been separated by the potash. Calcine them a long timein a platina crucible, and pour on thein sulphuric acid diluted with water, till there is a slight excess of it. ' This will dissolve the magnesia, and a portion of the iron, _ but not touch the manganese. 8. Evaporate the solution of magnesia containing iron, and calcine it strongly: the iros-will be separated, and the magnesia, on the contrary, will remain united with the sul- phurie acid. Dissolve in water, and the iron. will be ob- tained in the state of red oxide. Precipitate the magnesia by carbonate of potash, and ascertain its purity by the usual methods. , ' 9. Add the iron of the preceding operation to the mangae nese of experiment 7, and dissolve them both in an exeegs ‘of muriatic acid. Dilute the solution with water, and add carbonate of potash, till a red flocculent precipitate sepa- parates, and the liquid becomes clear and colourless, - These flocks are oxide of iron. Let them be separated by filtration, aud boil the liquor in a matrass. After some time, the manganese will fall down in a white powder, and when the liquor lets fall nothing more, and potash produces no effect on it, separate the manganese by filtration. Cal- cine it, and it will become black. Thus the alumine, magnesia, iron, and manganese, hav- ing been separated by the means just described, nothing remains to be done but to find the silex. 10. For this purpose evaporate the liquor containing the phosphate and sulphate of ammonia of experiments 3 and 4, As it concentrates, tolerably bulky black flocks are formed, _ which must be separated from time to time by filtration; and when the salt is thoroughly dry, it is to be dissolved in water, and a little more of the same black matter will be obtained. 11, Wash this floceulent matter, calcine it in a platina “crucible, aud a white powder will be obtained, passessing all * the pmppertia of silex. ¥ S$ 2 | During 460 Substances found. These vary in their propor- tions, The analysis very nice and dificult. Two proposi- tions of consi- derable im- portance to’ the theory of affinities. ANALYSIS OF NEURAL) SALTS. During these operations the ammonia is for the most part extricated, as well as the sulphuric acid, in the state of sul- pliite of ammonia, and the phosphoric acid is left tolerably pare. Caustic potash however still evolves a little am- monia. ) Thus, beside the phosphate of lime, this are in niikbam bones, as well as in those of animals, phosphates ‘of mag- nesia, iron, manganese, silex, and alumine. The last is in very smal} quantity; yet enough for its presence to be-fully _ recognized and established. It may be supposed, that in this method of-analysis ieditente bones will exbibit some variation in the proportions. of the substances, according to the age, constitution, state of health, and general belie of the persons to whom they belonged. ; It is equally essential to observe, that, shoei this ana- lysis exhibits a set of experiments simple enough in their description, it must be reckoned among the most delicate and difficult analyses, on account of the number of succes sive operations it includes, and the precision it requires... LY. Letter from Mr. Burzevius to Mr. BurtaHox.et on the Analysis of different Salis*. Tx snd yine Mr Richter’s work, * On ehdattve Subjects of Chemistry”, Part 1—X, 1795—1800, I found in it-two propositions, which appear to me of great importance to © the theory of affinities. ‘These are: 1. That all neutral salts, which remain neutral when their solutions are’ mixed, are so composed, that the quantities of the different bases, that saturate one of the acids present in the mixture, follow the same proportions in saturating the other acids: 2, That a metallic neutral salt, the metal of which is precipitated. by another more combustible metal, changes its metal only ; * Annales de Chim. vol, LXXVII, p. 63, | ecawit nt while bx | ANALYSIS @F NEUTRAL SALTS. 261 | while the portion of oxigen, that enters into the metallic | oxide, and the acid, with which it is saturated, continue thesame: and that the different metallic oxides, which saturate a given portion of any acid, all contain the same quantity of oxigen. «The first of Abie propositions appeared to me. the most The first ap- important. The experiments of Mr. Richter being for the ae patie most part defective, I began by applying this principle to @ great number of other analyses made by different che- mists; but among these I found only six, that. answered to the rule with any degree of accuracy. These were the analyses of the sulphates and muriates of barytes, potash, and soda, made by Messrs. Bucholz and Rose. The analyses of Mr. Kirwan corresponded very well with each other, but not with ether analyses. The experiments Ihave mentioned of Messrs. Bucholz and Rose, having afforded results differing only jn the thousandth parts, ap- peared to be the most accurate ; and almost the only ones, that were sufficiently precise for inquiries of this kind. To determine this point, and in order to verify the opinion of Mr. Richter in a more decisive manner, 1 proposed to my- Two sets of self to execute a series of analyses with the most scrupulous re iid ree _ exactitude; and for this purpose to analyse all the sulphates, vay the prin= and all the salts with base of barytes. From these two “?!* sets of analyses I could calculate the composition of all the other salts, and the result of this calculation remained to be confirmed by experiment. I had engaged in this pursuit in 1807, and given an account of some of the ana- -lysesin my ‘* Elementary Treatise on Chemistry”, which was publisked in. the beginning of 1808. The truth of the principle being fully confirmed by these analyses, no- — thing remained, but to complete the two sets of analyses Dhad proposed to myself. » At this juncture the discoveries of Mr. Davy on the de- Dr. Davy’s “ diiaiippsitiens of the fixed alkalis were published. The idea, eee ~ that all salifiable bases were metallic oxides, at once struck bases supposed me; and I had no doubt, that I should soon hear of Mr. ieee Davy’s having metallized also the earths and ammonia. repeated, however, with Dr, Pontin, physician to the king, t experiments of Mr. Davy; but, as we had only a very | feeble &F res) Oy 9 Attempt to form amalgam ofammonia, Attempt to ascertain the quantity of oxigen in am- monia. Muriatic acid saturated with different ox. ides. ANALYSIS OF NEUTRAL SALTS. feeble volfaic pile, we attempted by means of a metallic conductor, fastened to the negative pole, and immersed in mercury, to collect the small portion of metallic base, that appeared to be formed, The potassium was readily depo- sited in it, and the little globule of mercury was reduced to a solid amalgam. We repeated the same experiment with ammonia, which was decomposed still more readily. The mercury ad}ering to the end of the negative conductor yielded a metallic vegetation, res embling that which is formed when a salt with base of lead 1s decomposed -by the operation of the pile. The vegetation increased se consi- derably in bulk, that at length it separated from the ¢on- ductor, and, floating on the liquid, was converted into am- monia with effervescence, and evolution of heat. All my endeavourg to obtain this substance separate have hitherto ‘been vain. At first I considered it as a metal romposed of hidrogen and nitrogen; but the experiments of Messrs. A. Berthollet, Davy, and Henry, with which fT have since be- come degeapnitedh convince me, that this opinion was un- founded. Being unable to produce this problematic sub- stance without the assistance of mercury, T was desirous at least. of ascertaining the quantity of exigen, with which itis combined in ammonia; and perceiving the impossi- bility of doing it by direct experiments, [ had recourse to the principle of Mr. Richter: that all bases, which saturate the same quantity of any acid, must contain the same portion of oxigen. I weighed -with accuracy portions of the amalgams of. potassium, sodium, and calcium; I dissolved the metalloid i muriatic aerd, evaporated the solution, and fused the: salt ina small gold crucible. Thus I obtained results, that agreed very well with this principle. I had calculated the quantity of base in the salts from the analyses of the mu- riate of silver made by Messrs. Bucholz and Rose. It ap- peared, that 100 parts of muriatic acid saturated a quan-, tity of potash, soda, lime, oxide of mercury, and oxide of silver, containing 42 parts of oxigen. In consequence I analysed the uxides of copper, lead, iron. and zine; and, on combining them with muriatic acid, I believed | obtained the same results; but, after a number of tolerably accu. | curate ANALYSIS OF NEUTRAL SALTS. ; 263 . analyses, my expectation was so disappointed, that I found myself obliged to give up that principle; though, the more I reflected on it, the more probable it appeared. During “my analyses of these metallic oxides I had observed another circumstance that caught my attention, namely, that the quan- Ratios of the tity of oxigen which saturated 100 parts of metal in the oxi- o*igen in dif dule, was increased to half as much more, or double as much Pepe in the oxide. Thus 100 parts cf lead with 7°8 of oxigen form metal. the yellow oxidule, with 11°7 red oxide, and with 15°6 brown oxide: 100 parts of copper with 12°5 of oxigen form the red oxidule, with 25 the black oxide: &e. I then proposed to determine the quantity of oxigen Sionae tol in sulphuric and in sulphurous acid. ‘Yo remove all lows the same moisture from the sulphur, 1 combined it with lead. gies Lae found on this occasion, that lead absorbs precisely twice with metals. as much sulphur as oxigen at its minimuyi of oxidation ; and I soon ascertained, that it was the same with iron, cop- per, and tin. Iam since persuaded, that the native sul-. phuret of iron (the maximum) contains for every hundred parts of iron double the quantity of sulphur that exists in the artificial (the minimum, magnetic iron ore). From these circumstances sulphur appears to me to follow the same laws in its combination as oxigen. It follows too, that, the composition of an oxide being known, that of the sul- phuret is easily found by a simple calculation, and the con- trary: The sulphuret of lead, oxided by nitromuriatic acid, 7, sulphate produced a neutral salt, without either the oxide of lead or ia a sulphuret sulphuric acid predominating. 100 parts of lead combined a Mat 4, with 15°6 of sulphur yielded precisely the same quantity of sulphate. sulphate as 100 parts of lead dissolved in nitric acid, the solu- tion being afterward mixed with sulphuric acid, evaporated to dryness, and the residuum heated redhot. From these experi- ments I was persuaded, that the sulphuret of lead contains precisely the quantity of sulphur necessary for the formation of the sulphuric acid required to saturate the oxide of lead yielded: by the same.quantity of sulphuret. Experiments on the sulphuret of iron at a minimum, and on the sulphate of oxidule of iron, convinced me, that the same thing took place with the sulphuret of iron. . . From 964- ANALYSIS OF NEUTRAL SALTS. Ganciil awe: From all this I deduced the following consequences 3a. A metal combines with sulphur at a minimum in such a proportion, that, the sulphur being acidified, and the metal oxidulated, the result isa neutral sulphate of the oxidule: ‘b. A sulphate of an oxidule contains half as much oxi- gen as there is sulphur in the sulpharic acid, with — it is saturated. Composition From repeated experiments [ have found, that sulphuric of sulphuric ee M acid and sule acid is composed of 40 partssulphur, and 60 oxigen, almost phates. precisely; and that 100 parts of sulphuric acid saturate a quantity of base containing 20 parts of oxigen. The fol- Jowing is an incontestible proof of ‘the truth of this/opinion, which I was on the point of giving up.» On comparing the result of my experiments with that of the experiments of Mr. Bucholz, who had found 42 parts of sulphur and 58 of oxigen in sulphuric amd, 1 discovered, that his analysis of Sulphate cf sulphate of barytes was inaccurate. Aceording to hini this payor salt is composed of 32°5 acid and 67:5 base; I find it to consist of 34 acid and 66 base*, The inaceuracy of the analysis of the sulphate occasioned an inaccuracy in the ana- lysis of the muriate of barytes, and in that of the munate of silver. I endeavoured to correct these defects by! expe- Muriate of sile riments as accurate as possible, and found the muriate of are silver to be composed of 18°7 muriatic acid, and 81:3 oxide of silver. On applying these corrections to my former ana- lyses I perceived the harmony, that I had hitherto missed: Every thing then confirmed me in the opinion, that the dif- ferent bases, which saturate the same quantity of wile one contain the same quantity of oxigen, Sulph zrous On oxidating sulphite of barytes by means of dirie acid q acid, obtained neutral sulphate of barytes, without any superflus ous, sulphuric acid, or nitrate of barytes, -being. formed, The increase of weight of the sulphite taught me, that sul- phurous acid consists of almost exactly equal parts of sul- phurand oxigen; er, that 100 parts of sulphur combine with near 100 parts of oxigen to'form sulphurous acid, and with about 150 to form sulphuric acid. From these expes # For cnalyses of the sulphate of barytes by Mr, James, Thomson and, Mr Berthier, see Journal, vol. XXIII, p. 174, and 280, riments ANALYSIS OF NEUTRAL SALTS. 265 riments' I conclude, that sulphurous acid presupposes in the bases with which it is saturated the same quantity of oxigen as sulphuric acid.’ [It appears to me probable also, that the » metal and sulphur always remain in the same proportion to each other in the sulphuret, sulphuretted oxide, sulphite of the oxidule, sulphate of the oxidule, and combination with sulphuretted hidrogen. But I have proved, that the pro- portion between the metal and sulphur is altered in the sul- phates of the oxides, when the oxigen in the oxide is equal to that of the oxidule multiplied by 1-5. ; By the analysis of the muriate of lead 1 found, that the Examination base, which saturates 100 parts of muriatic acid, contains Gta, 30°49 parts of oxigen: and on calculating from this result the composition of the oxidnle and oxide of copper, of the oxides of silver and lead, and of potash, soda, and lime, I always obtained results agreeing sufficiently with these of the direct experiments. The sulphates of iron, copper, lead, .n4 of suf.’ Hime, potash, and soda, giving also, both by calculation and phates, experiment, results correspouding with each other and with those of the muriates, | have imagined, that this point may confirms the be considered as completely settled. It is to be understood, ? aria. - that’all these different analyses could not be carried to such perfection, as to give results not varying in the thousandths, and sometimes even in the hundredth parts; but these cir- eutmstances are to be ascribed rather to the difficulty of ex- ' ecuting analyses with reat accuracy, than to an erroneous principle. The oximuriatic acid -combines with metals, and forms Oximuriatic neutral salts, in which neither the acid nor oxide predomi- ae nates, Hence 100 parts of muriatie acid are combined with the same quantity of oxigen in the oximuriatic acid as inthe muriatic salts, that is to say, with 30°49 parts.’ In the experiments of Mr. Davy, potassium exposed to common Muriatic acid muriatie acid gas was Condensed, forming a neutral salt, aud 8% evolving hidrogen gas. It is evident therefore, that 100 parts of. muriatic acid are combined with a quantity of combined with water, that contains 30.49 of oxigen; that is, with 34:5 of “*“* water. Concentrated sulphuric acid contains, acco:diug to Saiphuric accurate experiments, almost a fifth part of water: that is acid to say, 100 parts of this acid are combined with 22°6 of eh? a : water; 266 ANALYSIS OF NEUTRAL SALTS, Allsubstances, Water, which contain 20 parts of oxigen... It appears, then, that combine that this rule may be applied to every other substance, mi-= witha given acd, contain a neral, vegetable, or animal, which forms with acids a mark- given quantity ed or neutral’ compound ; for instance, the matter of the of oxigen, : bile, albumen, and several colouring matters: In short, this law may be extended to all the acids, and every sub-. stance in any way capable of saturating them, Composition of water. tilled 4inc and ‘sulphuric acid. The decomposition was performed in an apparatus accurately weighed; and the hi- drogen gas was transmitted through a tube filled with muriate of lime.. 200 parts of zinc yielded 248°8 of oxide, and evolved 6°5 of hidrogen gas. According to this expe- riment water is composed of 11°75 hidrogen and. 88°25 oxigen; which agrees exactly with the experiments. of Messrs. Biot and Arago. On dissolving a quantity of sul- phuret of iron at a minimum ny muriatic acid, I received, the sulphuretted hidrogen gas in a caustic lixivium, by which it was eutirely absorbed. Henee it follows, thattthe - sulphur, which saturates 100 parts of hidrogen, must.be to. the oxigen, that saturates the same portion, in the same . ratio as the sulphur is to the oxigen with which 100 parts of Sulphoretted iron are saturated. The quantity of oxigen that saturates iidrogen 225. 499 parts of hidrogen being 75077, the quantity of sulphur must be 1501°54, and sulphuretted: hidrogen gas is com~ posed of 6:243 hidrogen and 93-756 sulphur. Composition After all these experiments I thought, that a tcuaatiok efammonia. of the composition of ammonia might afford a result, that would at least approach the truth. Accordingly I analysed the muriate of ammonia, and found it to be composed of: 49°46 muriatic acid, 31°95 ammonia, and 18°59 water of crystallization. Consequently 100 parts of acid are satus. rated by 64°6 of ammonia. From analogy with the other alkalis this quantity must contain 30°49 of oxigen: and) hence it follows, that ammonia is composed of rs 2 seniors and 52°8 metallic base. Quantity of oxigen in an mine in some measure the quantity of oxigen in the acid ser bplnl saa required for its saturation; but this proportion was not 80 that inthe easy to find as that between the acid and oxigen in the base, I was ‘To ascertain the composition of water I employed dis- . It was to be presumed, that a salifiable base would aides: ANALYSIS OF NEUTRAL SALTS. 967 1 was fortunate enough however to discover it. It is as fol- vase which lows neuttalizes it. *¢ In a compound formed by two oxided substances, that Law of the which, in ‘the circuit of the electrical pile, ranges itself POPortion, round the positive pole (the acid, for example) contains two, three, four, five, &c. times as much oxigenasthat which ranges itself round the negative pole (for example, the alkali, earth, metallic oxide).” This law, being applicable to many other combinations besid¢ salts, will soon impart to chemical ana- lysis an unexpected degree of perfection. Most acids con- tain twice as much oxigen, as the bases that saturate them, as ‘the carbonic acid ; others three times as much, as the. sulphuric acid for instance; and others, as the hyper- oximuriatic acid, as far as twice* as muci. In all these eompounds water acts an important part: sometimes we find it uniting as a base with the acids, for instance with the erystallized vegetable acids and mineral acids ; and at other times taking the place of an acid, and combining with the alkalis, earths, and metallic oxides, forming what we called hyd rates. There is every: appearance, that the muriatic ee: €OU- Compounds of tains twice as much oxigen us the bases that saturate it, the muriatic In-this:case it is esiaucnad of 61:3 oxigen, and 38°6 base ; a With 2s or 100 parts of the base combine with 156 of oxigen to form common muriatic acid, with 234 to form oximuriatic, and with 624 to form the hyperoximuriatic. It is but very lately, that I have had an opportunity of Bulks of gasses reading the interesting work of Mr. Gay-Lussac on the oe anna bulks of the gasses that enter into combination. It is evi- f dent, that his experiments confirm a part of the ideas, which I have had the honour to communicate to you. They con- tain facts, of which I have availed myelf, to acquire informa- tion on a subject, the knowledge of which it was highly | important to me to obtain. diecbbing to Mr. Gay-Lussac, Compounds of 100 cubic inches of carbonic oxide gas mixed with 50 cubic carbon and soni of — gas produce 100 cubic inches of carbonic Pe * ag the ecg 2 fois, but the figure is palpably erroneous from the context, From the succeeding paregraph it should probably be 8 fois; eight times instead of twice. C. : acid 268 ANALYSIS OF NEUTRAL SALTS. acid gas, Consequently carbon combines with oxigen in two proportions, one of which is double the other: and as Composition of inflanima- dle gasses. Salphuretted wouriatic acid, ‘Touro oxides of tulpbur. 100 parts of carbon are combined with 251°637 of oxigen in carbonic acid, they absorb 195°818 to form ‘carbonic oxide gas. Dr. Thomson in his analysis’ of inflatimable gasses has given the following particulars respecting ear- buretted hidrogen gas. 100 cubic inches of carburetted hidrogen gas consume 260 ¢. i. of oxigen gas, and form 100 c.i. of carbonic acid gas: 100 c.i. of olefiant gas consume 300 c. 1. of oxigen gas, and form 200 c. 1. of carbonic acid gas. By a very simple calculation we find, that 100 parts of carbon combine with 10°7597 of hidrogen ata minimum, and precisely twice as much at a maximum. Wesee by the analysis of ‘sulphuretted hidrogen gas, already mentioned, that 100 parts of sulphur combine with 6:66. of .hidrogen. If from these data we endeavour to calculate the degree of oxidation of sulphur that answers to the gaseous oxide of carbon in the following manner, 16-7597: 125°818: : 6°66: 49°997, we perceive, that there is a point of oxidation of sulphur, in which 100 parts of sulphur are eeiahiabes with 50 of oxigen very nearly. On examining Mr. A. Berthollet’s experiments on sul- phuretted muriatic acid, if [ may be allowed the term*, we see, that 100 parts of sulphur had condensed 204 of oximu-~ riatic acid, contatning 47°67 of oxigen. In the experiments of Messrs. Bucholz and Gehlen care was taken to combine with the acid the greateft quantity of sulphur possible; and 100 parts of sulphur yielded 211 of the mixtures so that 100 parts of sulphur were combined with 25°19 of oxigen and 85°91 of muriatic acid. Admitting, that Mr. Berthol- let muft have had 214 parts of oximuriati¢ acid combined vith 100 of sulphur, and Messrs. Bucholz and Gehlen. 107 parts combined with the said quantity, we have two oxides of sulphur, one of whichis composed of 100 sulphur and. 25 oxigen, the other of 100 sulphur and 50 oxigen... Thus the compounds of sulphur with muriatic acid forma muriate of the oxidule of sulphur, and a muriate of the oxide, From * Certainly Dr. Berzelius need not scruple to use the name given to this compound by its discoverer, Dr, Thomson, for wboiR account of it 282 Journal vol. VJ, p. 404. C. p -..' “hia ANALYSIS OF NEUTRAL SALTS. 269 this view of things I have concluded; that the degrees of ox- idation, which appear to be multiplications by 12, are in fact only multiplications by 6 or 12 of a degree of oxidation ‘at a minimum, which is not known, because it cannot exist ip a separate ftate. , I have lately read in the Phibephiceh Annals of Messrs. ie hai Gilbert a paper by. Messrs. Thenard and Gay-Lussac, s i eee which appears to prove, that the amalgam of ammonia is a °(g°s. compound of mercury, alkali, and hidrogen. I cannot however be of their opinion: for, having demonstrated by incontestible experiments the oxidation of the metalloids of potash and soda, it would be highly inconsistent to suppose, that ammonia alone fhould exhibit phenomena so similar in outward appearance to those ‘of the fixed alkalis, earths, and metallic oxides, while intrinsically they were of a totally different nature. I am convinced, therefore, that the sub- stance in ammonia, which forms an amalgam with mereury in the circuit of the pile, is a metal as indecomposable as the others. But, supposing this, it naturally. follows, that Hidrogen and hidrogen and nitrogen muft be its oxides, as Mr, Davy had aac ee already Scahipbaed*,: From the laws that I have endeavoured different ox- tovestablish it would be easy to determine the quantity of sae oxigen, that enters into each. If, as I have endeavoured to ammonia. prove, ammonia is composed of 100 base to 89°4 of oxigen, we shall find the quantity of oxigen, which with 100 parts of the base forms hidrogen, by dividing 89°4 by 2, 4, or 8 The quantity of oxigen necessary to convert these 100 parts of the base into nitrogen will be 89:4 multiplied by 1°5, 2, wi &e. We shall have found the true proportions, Be es, the Compounds of quantity of hidrogen and nitrogen gasses produced from ammonium ammonia by means of electrical discharges contain, ac- sen hacks cording to these calculations, the same quantity of oxigen asammonia. On dividing 89°4 by 8 we shall have the oxi- gen necessary to form hidrogen with 100 parts of the base ; and on multiplying 89°4 by 1:5 we shall have the quantity ‘required for the formation of nitrogen. , On reducing the _ ‘measures of gas to weights, we shall find, that 18°66 rs. of © Dr, Davy has since been inclined to re this nieGam. Cu ‘ ammonia Hidregen evalved from Proportion of oxigen to hi- drogen in wa- ter. ANALYSIS OF NEUTRAL SALTS. ammonia yield 14°85 of nitrogen, and 3°61 of hidrogen, in which we shall find, aceording to the calculation above men- tioned, 8°8 of oxigen. It is very natural, that [should hi- therto have been able to obtain only tolerably near approxi-— mations to the truth, and thus trifling differences may exist, without the principle, on which I have founded this calcu- lation, being erroneous. According to'this 100 parts of the base of ammonia, which I shall call ammonium, combine with 11°175 of oxigen, to form hidrogen. This quantity 1 shall express by 1 ox. The combination of 44°7.=2 4 ow. (ox- idule of ammonium) exists in all probability in the olives coloured substance formed by the contact of potassium with ammoniacal gas, That of 89:4 = 8 or. forms ammonia: and 134°) = 12 ox. forms nitrogen, which ought therefore to be composed of 57°28 oxigen and 42°72 ammonium. From the corresponding analysis of Messrs. Davy and Gay-Lussac, 100 parts of nitrogen combine with 57°3 of oxigen to form the oxidule of nitrogen [nitrous oxide] : but these hundred parts of nitrogen contain 57°3 of oxigen, so that in the oxidule-of nitrogen ammonium is combined with twice as much oxigen asin nitrogen; that is, 100 parts of ammonium are combined with 268-2 = 24 or. According to the analyses already quoted 36 ox. produce nitrous gas, and 60 ox. nitric acid. Between 36 and 60 the proportion of 48 is wanting, which, according to all appearance, belongs to nitrous acid. 76 ox. produce water, but this number stands too much alone to be verified by any caleulation*. Another circumstance, that has appeared difficult to ex- plain, is, that potassium evolves nearly the same quantity of hidrogen in ammonia as in water. If the experiments of Mr. Davy be as accurate as they appear, 100 parts of po- * The proportion of oxigen to hidrogen in water, on which Mr. Ber- zelius appears to have formed his calculation, is 88°25 to 11-75; but, if we take the oxigen in water = 72 ox., to use his expression, which is just double 36 oz,, the proportion of oxigen to hidrogen in 100 parts of water will be 87°7 to 12 3 very nearly. This differs but a trife from the con- clusions of yon Humboldt and Gay-Lyssac, adopted by Mr. Dalton in his Chemical Philosophy, Part ll, p. 274, 5: and the mean between the two will be a near approximation to 87°5 and 12°5, which ate precisely in the watio .of7 20 Cah) Fae r LGD be 4 Aba tassium ANALYSIS OF NEUTRAL SALTS. tassium decompose 37°8 of ammonia. O71 The potassium then ammonia by forms an oxidule, combining with 10°5 of oxigen, and it also Potassium. reduces:the ammonia to the state of oxidule. But these two oxidules must be combined in such proportion, that one contains twice or thrice as much oxigen as the other. If we admit, that the oxidule of potash contains thrice as much exigen as that of ammonia, it follows from this calcu- ation, which cannot be perfectly accurate, that the potas- sium must produce a quantity of hidrogen exceeding in # very trifling degree what it evolves from water. Table of the Analyses in the little Treatise I have the Honour to transmit to you. Oxides of lead. . avelien eeecece ——- Red. Brown Sulphuret of lead . eves Sulphate of lead ‘Morsiste of lead seeeee Carbonate oflead -+-s Sulphurous acides +++ ‘Sulphuric acid «+--+. Sulphate of barytes Sulphite of barytes Carbonate of barytes « - Sulphuret of copper- + Oxidule of copper «++> Oxide of copper-++«-- Sulphate of copper Sulphate of oxidule of e COPPErsececercecce. Muriate of oxidule of COPPET ses ecreeccee. Neutral muriate of ox- . 3 ide of COPPer ssesce “Yr iy Analysis of vas rious salts. Lead, 100 parts: oxigen, 7-7 Lae) 15°4 Sulphur, 15°445 Sulphuricacid, 100; oxide of lead, 280 Acid, 100; oxide of lead, 421-4 Acid and water, 16°5: oxide of lead, $3° 5 Sulphur, 100: oxigen, 99° 8 149°6 OR QTE eres ee necen, Acid, 100: base, 194 —— 86°53: water 4°25: 209°22 | —— 21'6: base, 78°4. Copper, 100: sulphur, 25°6 Copper, 100: oxigen, 12°5 25 Acid, 49°1: oxide, 50°9 base. 100: oxidule, 183 100: 278°4- 100: oxide, 148°7 Submuriate ‘ 272 ANALYSIS (OF NEUTRAL SALTS Analysis of va- Sabmuriate of oxide of noe ane copper ssseeese++ acid 100: oxide 596 Muriate of barytes--+-- ——~ 100: barytes, 288-2 -— 18°7: oxide, 81°3 gaa —- 100: —— 434°8 Oxide.of silver +eee-+ Silver, 100: osigeniT 9: Sulphuret of iron at 2 on minimum «++++++s Tron, 100: spar 58° Pen --- at a MAXIMUM secerees mm 1O0E Sulphate of oxidule of ie e rn ron so eocesesbosece Acid, 100: oxidule; ct vita * Neutral sulphate of ox- ; . ‘ide of iron ¢+se+.+. e100: oxide, 65°5. SS silver ‘sss ; - Gi Subsulphate of oxide of (Git Lamyhiai ORs ¢ Naas ey = 100: : 966 2 f= Pee | Oxide of irom +++ #+s-~Tron; 100: bid 44°95" an ¥ naa Oxidule oft iron s+ eee 100: 295 7? ne Potash: see ceaccnmecce Potassium, 300: oxigen 20° 49 sa Sulphate of potashes eve Acid, 100° potash, 11935" im Muriate of potash -+-- ~ 100: 179 : Soda sete teen eeee ee Sodium, 160 : ‘oxigen, 34°6 Sulphate of soda -+++ Acid, 100: soda, 79°34 Muriate of soda++-++. ——- 100: 118°627 Ammonia +++---+++- Ammonium, 100: oxigen, 189° 4 Muriate of ammonia - Acid, 49°46: wate 18° 59: ; base, 31°95: or, acid, 100: base, 64:6 Lime trereserooeeoe Calcium, 100: oxigen, 39°86 Sulphate of lime’ «+++ Acid; 100: lime, 72°Al Muriate of lime +e oe8s ——~ 100: Rar ae ts Barytes ¢++eeesseees Barium, 80°5: oxigen, 10°3 Oximuriatic acid +e-. Acid, 100: oxigen, 30°49 7 Common muriatic acid ot ‘ ZAS eececessceesee comm 100: water, 34'S | Oxide of zine sv ase +6 - ‘Zinc; 100: oxigen, 244 vane 100: oxigen, 75077: or oe 754—! '98°:246 sigue me hidrogen_ . —-— 100: sulphur, 1501-54: wale cd Geist eee Coates o—— 6°247; —— 93.753 tno ee awe | pee: V. A Water ++ seeeeseenens SUBSTITUTE FOR LEGHORN PLAIT. @73 4 y, Account of a Substitute for Leghorn Plait, for Hats, §c. whe Mr. Wiixu1am Corston, of Ludgate Hill *. “DEAR SIR, EBA vine: been honoured, in May 1805, with the gold Manufacture “medal of the Society, for a substitute of Leghorn plait for = Leghorn ; ait flourisa- hats, it is with great satisfaction that [ am able to inform f, ing. ~ you, that this country is now beginning to reap those ad- vantages, which I foretold to the Society six years ago, and ‘that many hundreds of women and children are at present employed in the various parts of this kingdom, in the manus facture of this article. * Tsold to two persons, in less than two months, upwards “ef 5000 scores, and had an order from a third for 2000. But this bears but a small proportion to the demand, and evinces the truth of the statement I made of the great ad- vantages hkely to result from the introdnction of this new - branch of manufacture into this country. “In Joseph Lancaster’s Book on Education, 1 have pointed 4 pplication of out farther advantages, which may be derived by the country waste land, at large, from the cultivation of waste and barren lands for the production of the material of which the British leghorn is made. ‘This has been proved by experiments, which I have made on Bagshot Heath, by favour of the Fari and Countess of Harcourt; and i in Bedfordshire, by the benevo- lence and public spirit of the Duke of Bedford; and on ‘barren land in Norfolk, near my native place. Indeed no soil can be too barren for this purpose, provided the seed will lie. Ihave shown, that 2000 acres might be annually cultivated in the growth of this article, daa” that a quantity of such | land might in succeeding years be brought into more ‘productive cultivation: but I am afraid, that this plan is ones i Trans. of the Soc. of Arts, &c. yok, XXVIII, p. 130. “Vou. XXXL. Dec. 1811. T ‘too O74 SUBSTITUTE FOR LEGHORN PLAIT. ‘too simple te be adopted ; although I cannot but yet hope, that the agrisultural societies of England will turn their at- aut cuaatese tention to a plan, which will/bring waste lands into cultiva~ ment for poor tion, and also provide employment for thousands of poor ig children. . If government would grant 3006 ‘acres. of the andy ‘which: lies waste on Bagshot. Heath, , fora few years, without any fine, and afterward on an inereasing- rent, ,ac- cording to the improvements of the soil,¢l wonldyraise, in straw alone, what should produce en article for industry, for pane “which upwards of £20000 would be paid annually , for the " paeliied employment. of poor children. lt is.a pleasing sight, for See ted Englishmen to behold the superb buildings which are appro» “ priated as asylums. for the children of our soldiers and sai- J Jors; but.in times like these, how, desirableas it, that build- ‘s ings of only one story high fhould be erected in, populous _ parishes, which might answer, the double purpose of schools of industry and Tnetraction, and thereby relieve ‘parishes from the burden of, the maintenance of poor children,, and also bring them up in habits of industry and sobriety ! In this way thousands of children may be employed from seven years of age, until they arrive at an: age sufficiently . ad- vanced to go out as servants. Straw manu- As by the mere invention. of the ‘splitting of a straw,.a facture. source of. employment has been, discovered, which, has i in- creased the returns in that branch not less” than. 3. or £400000 annually, I feel myself urged to call the attention of the discerning part of. the public to.a new. branch of industry, which I make no doubt will, ima very few years, add nearly au equal sum to the national industry, and also be a great means of bringing into cultivation thousands of atres of land now lying, waste. » Since the introduction of spinning by hand,- no source of employment has_ ‘been “discovered, which promises to afford occupation to so many thousands ; spinning by hand has been superseded by the inventions of machinery, but I believe it to be impossible for machinery to absorb this branch of mannal industry ; athe only spindles, wheels, or bobbins, engaged in this maak, with be, I trust, the fingers of little children. Straw hats will Some,persons may endeavour to cast a shade over site Se Hm | dempectatnets “by gepsidening ae prevalent attachment to ante Othe + SUBSTITUTE FOR LEGHORN PLArT. ors ‘the wear of straw hats as the whim of ‘the day; but I be-' lieve, that the superior comfort, in summer weather, arising from the wear of a light hat in preference'to'a heavy one, will induce gentlemen more and more to make’ use of the British leghorn ; and as to the predilection of ladies for hats manufactured of split straw, I think I hazard very little in considering that as established ; and when to our home con~ sumption is added a consideration of the demand for the East and West Indies, the coast of the Mediterranean and South America, 1 think myself very safe in asserting, that these mauufactures -will employ not. less» than, 60000 children. » Our poor’s rates amount to more than five millions Per Poor rates. “annum; and there can be no remedy for so great a burden > equal to: the setting the children of the poor to. work, so that’ they shall earn their own bread, instead of being ‘chargeable to the parish. It is true, that the demand for straw-plait’ has caused an’ increased quantity to, be made ; yet the demand is still superior to the quantity ;_and in the spring, the price often advances from 30.to 60, per cent beyond its fair value, even allowing sufficient profit to the poor employed, and the dealer in the article. I believe, The manufac - therefore, that this branch of manufacture is still in its in- pr = ~~ fancy, and that it is likely. to have great permanency ; and infancy. ' although it may, bv some, be considered as an insignificant source of revenue, yet when it is considered, that Providence has given. usthe means of improving the agricultural state of the kingdom, in raising the raw materials, and that so many thousands of ouy poor may be employed in its manufacture, T trust that every assistange will be afforded to so extraordi- nary a source of national wealth. _ If any person should doubt my arguments, I will beg The gale ale Jeave to state a fact in confirmation of my positions. I once Most wholly had the curiosity to put into the scale some straw I was about a hagye ‘tosell, and I found that it netted upwards of twenty three pounds sterling per lb. weight. If therefore, an article, which in its unmanufactured state is considered as of little worth, can, merely by the industry of children; be rendered “go Valuable, I think I risk very little in affirming, that by the encouragement of the British Leghorn, together with T 2: that pis vt t . 276 ON VARIOUS EAST INDIA DRUGS. thatiof split straw, we gain a sure means of bringing our waste and barren,lands into cultivation; and, by the employ-’ ment of our poor children, we acquire an infallible means of -greatly diminishing our poor’s rates. Theryeshould » In order that. the British plait may equal, the Italian j in be sown on the desbnaee finsisests [ partieularly recommend, that the. rye shonld be ren land. sown on the most waste and barren land, without any refers ence to its produce but merely ofthe straw, the sale of which would afford ample remuneration; and. I should, be happy to take the produce of from 50 to 100 acres, of such Jand, provided it lay convenient to the place of my manu- factory. By such means, the most unproductive wastes will ¢ become vainable, and a great source. of advantage opened for the employment of y sung children, and peneane incapa- ble of hard work. itsai MD rai An opportunity is thus offered for paaavalane Se Ay to build cheap schools in villages, and assemble, the children of the poor together, to whom literary instruction might-be given, and. the children enabled, to earn their own minass "4 and the whole effected at a trifling expense, |» yy rene nadreis tog I flatter myself, that it will give pleasure to the Sieciety to find, that T have not neglected an object, which has me- ‘ yited their attention; and which will be the means of saving immense sums'to this country, which have herétofore been sent abroad for the purchase of an article, which our poorest lands and feeblest peoplecan furnish. 1 remain, ne wine Vout obliged and obedient Servant, «...« “ WILLIAM 1 CORSTON. pend Street, May 10518106 90-4 ee s j ; NMI: +3 t metas ’ sas +f cit ag a Correspondence of Dr. Wiit1am Roxsuren, of Caleutta, with Dr. C. Tayior, Secretary to the att of Arts, §e« on various Drugs.* nisi I te phelps | ity Fath: fh East Indi ua ae ty FIAVE the rad to send you a quantity of ena swietenia — ” India fever bark, discoyered by me about fifteen years ago ; ad since which period it has had numerous fair trials. in many BT * Trans, of the Soc. of Arts, vol, XXVIU, pe 308, sults ie Oe (parts, ON VARIOUS EAST INDIA DRUGS, QTR parts, which have been attended with every’ suecess, that could be wished as'a substitute for Peruvian bark, for which I first ventured to propose it. A figure asd description of the tree, which furnishes: this bark, have been published under the name of swietenia. Sebrifuga, in my account of Coromandel plants, vol.-1, page 18, table 17.. It is a large timber tree, a native of the various mountainous parts of India. You willobserve, that r:5 properties. this bark possesses an agreeable odour, and from numerous experiments, which { have made with fresh bark, [ have drawn the following conclusions :— 5 1. That the active parts of the bark of swietenia pera are much niore soluble than those of Peruvian bark, paru- eularly in watery menstruums. _. a, That it contains a much larger proportion’ of active, bitter, and astringent powers, than Peruvian bark. 3. That the watery preparations of this bark remain good much longer than similar preparations of Peravian bark. 4. That the spirituous and watery preparations bear to be mixed in any proportion, without decomposition. _§. That this bark, in powder, and its preparations, are more antiseptic than Peruvian bark, or similar linia thereof. In my practice I generally . gave from twenty to sixty Method of ad- praca of the fine powder in substance, either in wine or sian water, as circumstances required, and commonly.as often as Peravian bark is usually prescribed, ‘Trecommend, that some of this bark may be sent to the It may be fenny countries, where intermitting fevers prevail; and if it ae ae ss is found to answer, which I have no doubt of, it may be imported from the East Indies at so low a rate, as to render its use very general, on acconnt of the high price of Peru- n ba: , wi aay Tam, Dear Sir, Mo ons, Your most obedient Servant, March 28, 1806.) W. ROXBURGH. od er * From experiments since made in England, the swie- Experiments gar bark has been found a-valuable medicine in inter= in England. mittent fevers, scrofula, and in disorders usually termed nervous, , yee | DEAR B 278 A cheap resin from the saul, or shorea robusta, ON VARIOUS EAST INDIA DRUGS. DEAR SIR, 24 I wrote ‘to you lately, along with my paipekd on the ma- nufacture of indigo, and of some newly apoaetee plants, which yield that drag. . ; It appears to me vow, that it will tend to a uéefal purpose to put the Society in possession of samples of a very cheap resin, ‘the produce of one of our largest and best timber trees, called by the nat ves of Bengal, saul, and by me, Shorea robusta. Wt is one of the substances used in our. Indian naval yards under the general name dammer; and is a substitute for pitch and tar. To bring it to a proper consistence for such use, it is boiled up with some cheap vegetable oil, (the Hindoos being forbidden by their religion to use any animal oil), and more or less af the vegetable oil is added, according to the purpose for;which it is wanted. The Society will probably find it also applicable to. other - uses, as itisa pure resin, cheap and plentiful:.the price. of “at here is from three halfpence to two pence per pound. I tack myroba- Jans. wish to know, whether it has been yet known in England, and whether it is likely to be in demand. It will probally. be useful for making sealing-wax, and for varnish, I am, my dear, Sir, = Yours very obediently, ad ri Calcutta, Jan..18, 1809. sooW, ROXBURGH. MY DEAR SIR, i thd I have now sent to you farther samples of the resin of my shorea robusta; and | have also sent a parcel of the black myrobalaus, (myrobaulanus Indica), the origin of which has © hitherto been unknown. I believe, that they are the unripe fruit of the same tree, which produces the chebulic myrobas lans; and you will trace the cause of my vow having disco- vered the tree which produces them in part 3 of the eleventh volume.of the Asiatic Researches, containing a catalogue of Indian medicinal plants and drugs, with their names. in the Hindustaniand Sanscrit languages, by John F leming, M. D.; pages 2G, 30, and 31, shiek the author sends to you for the Society. But though their medicinal virtues are in ‘high repute over Asia, I do not send them to you with that view alone, ON. .VARIGUS EAST INDIA DRUGS. 279 alone, but rather because I think they contain much funnin in Thev contain little bulk, and may therefore be useful, and save the British much tannin. vak plantations. I fear the gaub extract, from the fruit of embryopteris glutinifera, which I sent you some tine since for the trial of the tanners, may not have answered so well ag I expected, otherwise that you,would have applied for more of it. i ene I take the present opportunity to request you will correct Hurra, the a mistake i in my letter of June 18, 1504, published in the fut ee 23d: volume of the Society’s ‘Transactions, page 408, where I bud kurra was the fruit of terminalia citrina ; T now find it is the fruit of terminalia chebula.—See Coromandel! plants, 2, No. 197, and of Wildenouw’s edition of the Species Plantarum, 4, 969. 1 now send to you a drawing and description of the tree, and of the myrobalans in their various stages, both fresh from the tree and dried as men- tioned by Dr. Fleming. The small parcel within the other | contains some of the drug purchased in the bazar, viz. four | pounds weight, for which I paid one shilling. The remain- der are fresh gathered from two trees in this garden, and hastily dried in the sun; they are ratheradvanced, and may” answer to the fourth, fifth, and sixth sorts of the drawing; - and among those of the bazar will be found the three first. I have also. sent you some more fever bark, part of the. produce of a young tree which erew in this garden. It is * _ difficult to judge how long we may be conveniently sup- _ plied with Peruvian bark ; and it is therefore very proper, that this valuable substitute should be brought into general use ‘as soon as possible, and if it is likely to meet with exten-= sive. demand, I will contrive that some of it be sent home for sale. Pu “In the same package is enclosed some bark of a new spe~ Naw species af cies of brucea, which is said to be a most powerful medi- brucea. cine; it is the dussa radga of Ruimphius’s Herbarium Am- boinensis, 7, p. 27, t. 15: itis a thin bark, and may pro-, bably be as good or better than simarouba. In the same bundle i: is whistles parcel, which is the conessi bark of our Conessi — | Materia Medica; it has an austere bitter taste, and is re- commended i in dysenteries, as Ke, as an astrine . gent. 280 Gaub extract. Samples for trial. The funda- mental pro- ON THE FUNDAMENTAL PROPERTY OF THE LEVER. Pent. cal wish to receive the opinion of the maith) on these and other articles, which I have sent. l am, dear Sir, ae Yours very obediently, Calcutta, Oct, 3, 1809. _ W. ROXBURGH. eS MY DEAR SIR, Captain Richardson having been detanniad thus cane and this being the season for the gaub fruit, I have made a few pounds of the extract, which is packed in the same box with the articles mentioned in my former letter. At the bottom of the box there are ten pounds made with’ cold wa- ter. Immediately above it is another stratum, weighing six pounds and a half, made with hot water from the refuse left after the cold water process. These two parcels, with that E . sent you formerly, will certainly enable the Society to as- . certain and let me know what prospect of success this ex- © tract holds out to yourtanners, I request the Society will | order experiments to be made therewith as early as possible, and I anxiously wait for letters from you acquainting me with the result. I remain, dear Sir, ee Yours truly, Calcutta, Nov. 21, 1809. ~ W. ROXBURGH. : ee ao *,* Samples of the several articles above mentioned will be delivered for trial to such persons, as will engage to fa~ vour the Society with the result of their experiments thereon. | VII. | Demonstration of the Fundamental Property of the Lever, by Dayip Brewster, LL.D. RS. Edin. $ Ir is a singular fact in the history of science, that, after | all the attempts of the most eminent modern mathemati cians, * See farther partic ulars of this bark i in Dr. Roxburgh’ S Treatise of Ne- rium Indigo, p. 254 of this ei a under the name of of fer yeth's tericum, si t Trans. of the Roy. Soe, of Edinb. vol. VI, p. 373. @N THE FUNDAMENTAL PROPERTY OF THE LEVER. O87" to obtain a simple and satisfactory demonstration of the fun- ad off the damental property of the lever, the solution of this problem ! he in like manner be shown, that, in these cases, the pro- _ position holds true. Prop. Ti: If two forces, acting at the extremities of the two Prop. i. arms of a lever, and at equal angles to the arms, are tn equi- “Kibrio, they will be reciprocally proportional to the lengths of the arms to which they are applied. Let AB, CD (fig. 2.) be two levers in contact at AB, and Demonstrated. forming one straight line, ABCD. Bisect AB in f, and cD ing, and from the extremities A, B, suspend equal _ weights m, m, and from the extremities C, D, equal weights m,n, so that min=CD:AB. If the twolevers are now sup- ported on the fulcra f, 9, they will both be in equilibrio, and will ftill form one straight line, the fulcrum f being loaded with a weight=2 m, and the fulcrum ¢ with a weight=2 n. Let us now suppose the extremities B, C, of the levers to adhere, and form one inflexible line AD; and let an in- verted fulcrum F be placed at the point of junction. The equilibrium of the whole will evidently continue, and the _ fulera f, 2, will be loaded as before,. Remove the fulcra f, Ps >, and substitute in their place the weights 2 m, 2, acting . “upwards, and, equal to the load which they respectively sup~ _ port: The equilibrium will still continue. Now, instead of "the. force m ACHING: downwards at B, substitute an equal and "opposite force m’, acting upwards at A,,and instead of the force n acting downwards at C, substitute an equal and op oo? posite 234° Lemma. Demonstrated, Prop. I}I. Demonstrated. , the side AX=AY, and Ax=A y, on account of thoequality ON THE FUNDAMENTAL PROPERTY OF TRE LEVER, posite force n’, acting upwards at D, and the equilibrium will still be preserved. But the two equal forces acting in opposite directions at the points Avand D destroy each other; therefore we have’a force 2m acting at the extremity of the arm fF, in equilibrio with a force 2 n, acting at the extremity of the arm @ FE. But since, by the hypothesis, m:n as CD: AB, and since? F is one half of AB, and oF one half of CD, we have 2m:2n=9-F :f F, an analogy which expresses the fundamental property of the lever. Lemma. Two equal forces acting at the same point of the arm of the lever, and in directions which form equal angles with a perpendicular drawn through that point of the arm, will have equal tendencies to turn the lever round its centre of motion. Let AB. (fig. 3,) be a lever ssi Pepe arms s AF,. FB. Through the points A, B, draw AD, BE, perpendicular to AB, and AP, Ap, BW, Bw, forming equal angles with the lines AD, BE. Produce PA to M. Then, equal. forces acting in the directions AP, Bw, will bein eqnilibrio. . But a force M equal to P, and acting in the direction AM, will. counteract the force P, acting in the direction AB, or will have the same tendency to turn the lever round F; and the force W, acting in the direction BW, will have the same tendency to turn the lever round F as the force M; conse- quently the force W will have the same Fengeney. to turn the lever round F as the force w. Prop. Ill. Ifa force acts in different dicoctmiadt the same point in the arm of a lever, its tendency to turn the lever round its centre of motion will be proportional to the perpen~ diculars let fall from that centre on the lines ae direction i % | _which the force is applied. - : Let AB, (fig. 4,) be the lever, aia let He two snail forces BM, Bm, act upon it at-the point B, im the direction of the lines BM, Bm. . Draw BN, Bn, respectively equal to BM, Bm, and: forming the same angles with the: ling PBw perpendicular to AB. To BM, Bm,» BN, Buy pros duced, draw the perpendiculars AY, Ay, AX;Aa. Now, ef ON SHOOTING STARS. 9385 _of the triangles ABX, ABY ; and if MJ, Ma, be drawn _ perpendicular toBw, the triangles ABY, BMJ, will be simi- Jar. and. also the triangles ABy, Bma: Hence we obtain five ener ya oc &B vAY= BM: B&) and eats. AB:Ay=BM: Ba “Therefore, exa@quo, AY: Ay=—Bil: Ba Complete the parallelograms BM o N, Bmwn; and Bi, -Bawillbe respectively one half of the diagonals Bo, Bw. ‘Now let two equal forces BM, BN, act in these di- ‘rections upon the lever at B, their joint force will be re- ‘presented by the diagonal Bo, and consequently one of the forces BM will be represented by B/=3 Bo. 1n the same ‘manner, if the two equal forces Bm, Bn, act. upon. the. ‘ever at B, their joint force will be represented by Ba, and ~oue’ of them, Bm, will be represented by Ba=! Bw. equently the power of the two forces BM, Bm, to prrerrin ‘lever roynd its centre of motion, is represented by Bi, Bx, respectively; that is, the force BM is to vthe force B mds Blis to Ba; that is, as AY is to Ay, | ~ the: Peeeaidrs rye fall upon the lines of their di- rection: — ; TILA 4 ~ ‘ ‘ : a a4 cone Tae VII. ' y nh ee ‘Nature of haa! Meteors commonly called Shooting i Stars. Ina Letter from Joun Farey, Senior, Esq. ay To WILLIAM NICHOLSON, Esq. a * . In several Meteorological Reports of late, and particularly - in aletter from Mr. Thomas Forster, at page 131 of your Shooting stars October number, the appearances usually denominated sRPRORY see shooting stars are noticed, and treated of as being a pheno- with elcctricat “Menon connected with the electric and other particular of rtd nied state of our atmosphere, particularly ‘ clear dry weather mosphere. “cand easterly winds,” “clear frosty winter nights,” and Its cleamess ** the clear intervals of showery weather.” Now these three *PParently ne- et states 886 S “ON SHOOTING STARS. cessary to our “states of the air are best adapted, by its clearness, for seeing sseing them. the smaller stars and planets, or any small distant object by land ; and I wish particularly to call the attention of your Meteorological Correspondent to liotice, whether the ab- sence of the twilight, moon-light, &c. is not equally essential to seeing numbers of the small rapidly shooting-stars;'as I ‘certainly found them to be, in ‘a series of observations conti- nued for more than a year in 1800'and 1801, in Gonjunction with an able friend at 6 miles distance; and whence it seemed ascertained, that these phenomena (are occasioned: by Probably they an almost infinite number of satelliiule,’ or very small sf whichan int Oons; constantly revolving vound the Earth, in“all possible Snite number’ directions, and appearing only during the very. sbort time rh Linn: that they dip into the upper part of the atmosphere: each the Earth, ‘time that they are in perigee < and that no step seems want~- ing in the degree of this dip into the atmosphere, and their consequent brightness; length, and slowness of courses, &c. from the smal» between the smallest instantaneous shooting-stars, and the i tod. largest meteors, (such as that of August, 1783, alluded to by ars, your correspondent,) which throw off with explosions angu- - lar fragments of metallic and stony matters, that so fre- quently fall to the Earth, as meteoric stones. The long. “trains or streaks of light, often mentioned-as eft by meteors for some instants, will frequently be found mere optical de- ceptions, owing to the eye not following the meteor, but suf- fering it to cross the field of sight, ree its. impression’ is left, on known optical principles. Hoping to see this important class of phenomena more been, Hated een I remain, Sir, “” : -Your obedient humble Ser vant, eee ee ) JOHN FARES: Sen. “Upper Crown Street; Westminster, lauisw > fede toby Sth Now. W8ble eh ee (ai anual ‘ mes ° aT ON a ba Go closely and extensively investigated than they hitherto have Hm ON PREVENTING THE DECAY OF SHEPS. 287 ve IX. : On the Causes of the Decay of the Timber in Ships, and the pieaees of preventing it. InaLetter,from a Correspondent. , To WM, NICHOLSON, Esq. | yah Ok ley STR, Tus dilvantages that England derives from her. marine, Shippatg of o whether considered as appertaining to commerce or defence, 8f¢%t imports are:too well known to need any comment; whatever then cout _cwill contribute either to the safety or durability of the navy -becomes.a matter of great public importance. i , \) “Phe grand cause of the decay of the timber employed i 18 Causes of tha » building of ships is the decomposition of its substances by deoty aes «putrefaction, which is occasioned by moisture. This pre- i /eautions and management may’ retard, but not. prevent; - but’a secondary one, the dry rot, may, I think, be both pre- . reented and eradicated: <0) ~The ary rot, as it is usually called, aicient from the The ary'tot “seaniiie of a parasitical plant, named by. botanists: boletus known in very lachrymans, which belongs to the class of cryptogamia. Its ee "injurious tendency is mentioned as far back as. history will -carry us, and the appearance and ravages are, particularly , pointed out in the Bible*.. ‘The cure there directed, 18, to Remedies for _remove the materials injured ; and, if this did not stop the it. iidicate, the house was razed, and the entire articles of which -it was composed taken without the city. In latter times an equally effectual but more easy remedy has been applied in buildings, where this plant has taken root ; that of causing ‘a circulation of air in the parts affected; but this cannot be introduced in the fabrics of which we are now treating. '. The fatal tendency of the dry rot in ships cannot be fis; injurjous- pointed outin a more forcible way, than it is in the memoirs 9°85 to ‘he of Pepys, who was secretary to the Admiralty during the pre Peres ‘reigns of Charles the 2nd, and James the 2nd. At that time a commission was formed to inquire into the state of Mary = c \ Bia -o' & 4 ort * Leviticus, Chap: 14. , : wu the 23 -QN PREVENTING THE DECAY OF SHIPS. the navy, by which it appeared, that there were thirty ships, called new ships, which, as he observes, “for want of pro- ** per care and atténtion, had toadstools growing in their 's€ holds as big as his fists, and were in so ‘compleétea state of “** decay, that some of the planks had dropped from their ** sides.” From that time to the present, the evil has in "some measute existed ; and, although it has not since ap- peared in so great an extent as it then did, yet thestate of and at present, some ships recently launched both justifies and demands all possible inquiry as to the causes of the growth of this fun- Attempts to gus, and its prevention. Several means have-beew tried to remedy if prevent its vegetating, many of which might haveanswered this purpose, had they not been found to introduce evils as great as that which they pretended to cure, Among the most prominent, was the mode practised on the timbers of | by salt ‘many ships, between the years 1768 and 1773, by saturat~ ing them with common salt; but this was found to cause a -tapid corrosion in the iron fastenings, and the ships’ were (between decks) in a continual state of damp vapour. Mun- dic, found in the mines in Devonshire, ‘has been lately em- and mundic. ployed, in fusion, to eradicate the vegetation, and prevent ' | its future growth; but time is required to prove its efficacy. Production of | In thecommon mode of constructing ships there are seve- carbonic acid “yal causes, which promote the growth of fungi. | The accu- gas injurious: é : es, mulation and consequent fermentation of materials not suf- ficiently seasoned, divested too of a free circulation of air, and permitting sap to remain on ‘the edges of the frames, generate carbonic acid gas to the prejudice. of the timber, ‘ind which promotes the growth ofthis boletus., Mr. Hum- boldt has found by experiments, that eight or ten hun- dredths of carbonic acid gas, added to the air of the atmos- phere, rendered it extremely fit for vegetation; anid that the air in mines, and other subterraneous passages, was found in this state, which is very favourable to the germination of all plants of the class cryptogamia. The gas found: in the openings between the timbers of ships affected with the dry rot has been proved, to be wwe what Mr, Humboldt has wentioned, Means pre- The means, that I propose to prevent or cure this evil, are ; posed to pre- twofold: ¢harring the whole. surfaces of the timbers, and ? the GN PREVENTING THE DECAY OF SHIPS. 289 the inner surfaces of the planks, of which the ships are com- vent or cure posed ; and causing some slight deviations to be made in the oe or modes practised in building them. I do not pretend to ori- surface of the ginality, when I ean ead charring of timber, either to ¢™>er add to its durability, or prevent the growth of parasitical yg i, plants ; ; for the experience of ages has proved the i incorrup- tibility of charcoal, whether Covi i in the earth, or ‘exposed to the action of air or water. The beams of the theatre of Proofs of its Herculaneum, which were reduced to this state by lava, Pam fa were found, after a period of nearly eighteen centuries, to durable. “be perfect. The piles, supposed to have been driven into ‘the earth by order of Julius Cresar, when he forded the Thames at Cowey Stakes, near Shepperton, were charred, and when recently taken up, found in’a complete state, free from decay! Among many other instances, that may be adduced, the practice, almost universally* adopted, of burning ‘the ends of posts to be put into the ground, to pre- vent premature dissolution, may be added as an additional proof of the efficacy of this recommendation ; and makes us lament, that it has not been generally introduced in fabrics, where so much timber, labour, and money, have been ex- pended ; and the hopes and expectations of govefnment or individ aals frequently disappointed, by their fairs decay. “There até several other advantages, that will be obtained Other adyan- by burning’ the surfaces of timber. Rats, which are so dé- tages from it, structive to ships, will not touch charcoal; nor will the white: ‘ants and cockroaches, so common in the Indies, com-= ‘mit their depredations on substances so prepared. 1f far- ther evidence of its utility, when employed only on a small scale, be mecessary, the durability of the Royal William, Instances of the flag ship at Spithead, which was built in the year 1719, gases and | the. planks only were burned on their inner surfaces, plication in \ pt be sufficient to prove its efficacy when practised Oh Ships. * I am inclined to think, that the writer is mistaken here; and that the ae: is very far from being even almost generally desis I remem- 4 vbera year or two ago speaking of it to a carpenter, who was putting down € posts ; arid ke observed, that it would make them last too long, an object they never had in view' in parish work. He added, that they sometimes charred the ends of posts, or more frequently dipped them in ; ag for a private customer, ‘Cif he particularly desired it”. C. Vou, XXX.—Dec. 1811, U “ships. 290 Frem the scarcity of oak substitutes have been em- ployed, chiefly pine. ON PREVENTING THE DECAY OF SHIPS. ships. Of late years the ends of ships’ beams have been charred, and the sound state in which they are now found has justified and established the practice. Indeed all sub- stances, that have undergone the action of fire, have been proved to be unfavourable to the growthof the boletus lach- rymans; for, while stone has been rapidly destroyed by it, well burnt bricks, in the same buildings, and in nearly the same situation, have been free from its attacks, The scarcity of English oak, occasioned partly by the im=- proved state of agriculture, but more by the increased num-~ bers of our fleet, has obliged this country to have recourse to wood grown in other states. The principal that have ' been introduced in aid of oak are the varieties of American Pitch pine ge- nerally dura. ble, but the soon- est destroyed gee 2 by fungi. Very impro- per for tree- nails. Pitch pine shoutd not be paixted, ' Preferable ap- plications. ~ pine: it becomes therefore of some importance to inquire, which sort of this timber is the most durable, and which the soonest destroyed by vegetation. Pitch pine has been used by all nations in the construction of ships, and appears to be very superior to every other species for general dura- bility ; but this wood is the soonest destroyed by fungi, as these plants are nourished by the great quantity of resin contained in its pumerons cells. I have lately seen some pitch pine plank of 7 inches in thickness completely de-. composed ; and, when cut open, the boletus was found to be vegetating in every part of it, but principally in the cells which were originally filled with resin. This proves how improper it will be to employ it as treenail fastenings, on which the strength and safety of ships so much depend. Pitch pine should not be covered with paint, as the pores of the wood are thereby stopped, and the expansion of the resin prevented, by which means the ligneous cells are broken, and decomposition, takes place. _The Ameticans . pay the topsides of their ships witha mixture of oil, resin, &e., which are not unlike the substances that’ are contained in the w ood they cover, and produce a hard varnish, imper= vious to water. Perhaps the preparation recommended b doctor Parry*, to prevent the dry rot, given in the Trane actions of the Bath and West of England Societies, might * It is made as follows: take 12 ounces of resin, 8 of rol! brimstone, 3 “gallons of oil, and 4 ounces of bees wax: boil tied together, and lay them on While hot. [See Journal, vol, XIX, p. ‘igi reve ee Ps €5 of ‘ON PREVENTING THE DECAY OF SHIPS. 2901 be introduced also for this purpose with success. White Whitewashing wash or lime water to be used between decks is much to pole Pay be preferred to paint, both on account of its cheapness and cleansing any and also as it is detrimental to vege- tation. Instead of the frames of a ship being converted to their Atterations proper shape for some months before they are put up, and. Proposed in afterward standing on a slip a year to season, as is now the Hd 3 hel usual practice ; T would recommend, that they should be converted, and remain, together with the planks, in that state (under cover where there shall be a free circulation of air) for two years, then charred, put up, and the planking immediately begun; commencing operations from within beard, by which means chips and dirt will not accumulate between the timbers; care being taken, that the holes be not bored tco near the seams in the outboard plank. Holes - should be bored, but no treenails driven till within a short time of the ship’s being launched ; this wiil both convey air within board, and carry off the vegetable juices, if any re- main in the interior of the os Hg The planks could be kept i in their places by the usual butt bolts, and some cop- per nails, or small bolts ragged, being driven at interme- diate spaces. ‘This too would strengthen the ship, as me- tallic fastenings are always to be preferred, in the wales and bottom ; to treenails. An objection may be made to the bringing round thick Remarks on planks in the bow of a ship by burning, rather than the ess usual practice of boiling them in a kiln, on account of breaking their fibres. Although I do not ‘see, that any dif- ficulty can exist in the former method, as it is the usual practice of the French; yet, if any should occur on trial, and boiling them be considered absolutely necessary, vege- tation may be prevented by dissolving some green vitriol in the water, and afterward fixing it in the-wood by a weak alkali*.. The method approved of by many judicious ship- wrights, and constantly practised by the Datch, that of __* Asolution of alum might also be tried {I should apprehend any sa- line impregnation of the planks would prove injerious to the copper sheathing and fasteviags. C.J * ms U2 sawing 293 A trial might be instituted on a smail scale, Platina may be applied on other metals in two ways. ON PREVENTING THE DECAY OF SHIPSs._ sawing the thick planks, that are to be much bent, into two. parts, might also be employed for this purpose. Ifa doubt should exist of the efficacy of wood prepared in these several ways to prevent the dry rot, specimens might be placed in a ship almost destroyed thereby, such a one as I recollect to have seen at Woolwich about 13 years since, which was in so “bad a state, that the decks sunk with a man’s weight, and the orange and brown coloured fungi were hanging in the shape of inverted cones from deck to deck. A few months trial of wood put into a ship so infected would prove the ef- ficacy of either mode of prepare ation. Exsiccation of timber in an oven, as recommended by Fourcroy, is also likely to add considerably to its: dura- bility. One farther precaution is necessary. Aftera ship is built, she should le at least six months in ordinary, with her hatchways covered to prevent the admission of rain water ; some planks should be removed in the ceiling, and above the waterways of the several decks ; and fires constantly kept in stoves, placed in the hold, and on the decks; by which means the moisture, that the charcoal may have attracted, will be dissipated, and the durability of the fabric insured. : Having stated these general circumstances with a view to prevent evils, which yearly exist to a great extent in the nav»; I trust it will be the means of calling forth ‘the opinions and abilities of those, whose minds have been directed, or whose occupations may lead them, to a consi~ deration of this important subject. Tam, &c. &e. 11th of November, 1811. _ NAUTICUS, Bis On the Art of Coating Metals with Platina : : by Mr. CR Di bh st Si . “% ] HE datilien of platiaa on other metals less valuable, to prevent their oxidation, may be considered under two points of view, or as two different arts. ‘The first of these * Ann? de Chim, vol, LXX VII, -p. 297, may ON COATING METALS WITH PLATINA. 293 may ‘be called platining [platinure}, as we say gilding, sil+ vering : the other plating, a term appropriated iy custom to a fe superficial application, requiring a different process. _Platining may be executed like gilding, either by the in- That of tervention of mercury, or by means of a solution of muriate washing. of platina in ether. 1. [long ago made known the possibility of forming an By means of amalgam of pintias, and described the processes for Teg aaaigee, ing it*. Mr. Proust, in a letter addressed to Mr. Vau-. iene quelin, inserted in the Ann. de Chim, »pluviose, an. 12 Proust, {February, 1804], hus said, that “ hot mercury poured on the spongy substance remaining after the calcination of ammoniacal muriate of platina, dissolves it perfectly ; and the result is a fatty amalgam, that does not grow hard by keeping, and spreads well on copper, gold, or silver; so that it might facilitate the plating of the former.” From the note following this passage it appears, that Foureroy and Messrs. Fourcroy and Vauquelin also accomplished this Vauquelin, amalgamation by the same process ; that they-even effected it without heat, and that, after having remained, fluid for some time, it became very solid; an effect that might be -accelerated by the application of a gentle heat. » Lastly, Mr. Hatchett published in Nicholson’s Journal and Count aul October, 1804, a Letter, in which Count Mussin en ity Poushkin gave him the particulars of the processes of amal- gamation, by means of which he rendered platina perfectly malleable. At present therefore we cannot question the union of platina with mercury by means of simple processes, not expensive, and producing a suitable consistency for a solid application of the fixed metal: but it does not appear, that the processes of this new art have hitherto been published fin France] with any details; I shall therefore make known those described by Mr. Trommsdorff in the 7th vol. of his Journal, from the communication of Mr. Straussf. % * * * * * + cennil 8 Chim. January 1798, vol. XXV, p, 14, and fol. + See also Nicholson’s Journal, vol. IX. [As the account that fol- Jows in the text is the same with that given at p. 303 of the vol. of the Journal quoted by Mr, Guyton-Morveau, it is omitted here as unne- | Sgeisary. C.] t Tf, 294 By means of ether. . Coating with platina. Tried with success on copper 16 years ago. ON ROARING: METALS WITH PLATINA. II. Another kind of platining, which appears particular- ly adapted to similar, works of polished steel or iron, to pre- vent their rusting, 1s that which results from the application of platina to their surface by. means of ether, It is well known, that, if a solution of gold in nitro- muriatic acid, be covered with sulphuric ether, and the two liquids shaken together, the ether will take the gold from the acid, acquire a yellow colour, and become capable of producing a true gilding, when applied to the surface of another metal. _ The celebrated Lewis said, that platina would not forin this union. Mr. Stodart supposes, that, if he did not effect the decomposition of muriate of platina by means of ether, it was probably because his platina was impure ; and he has published in Nicholson’s Journal* the process that suc- ceeded in his hands, Mi ok Mi A Of plating or casing with platina. From what has been said it-appears, that the art of pla- tining is not more difficult than gilding, and that it will have nearly the same advantage of preserving from rust those metals that are most liable to it. But at the same time it cannot be denied, that so thin a covering is far from promising the same durability, as that which is termed plating; particularly with respect to vessels and instru- ments continually exposed to the action of Gres a or to RAPS frequently rubbed. ~ . pt tte Ido not know, that plating with platina me yet been attempted in the large way : but there is every appearance that it wou!d succeed.as well as plating with gold or silver, and by the same well known processes. As a proof of this I have a small vessel in the shape of the bowl of a spoon, which was given me fifteen years ego by Professor Cha- baneau, on his return from Spain, where he first introduced the principles of modern chemistry in his lectures}. * Vol XI, p 282. [What follows in the text is omitted 3 Pe eine reason as in the preceding instance. C.] + Elementos de Ciencias naturales, &c. Madrid, 1790, This, ACTION OF VEGETABLE POISONS. 205 This vessel, 75 mil. [2-951 inch.] long, by 52 [2°046 in.] broad, and 14 [0° 55r ‘in.] deep, is made of copper, plated in the inside with platina. The thickness of its edges is 0°78 mil. [0°3 of a line]; it weighs 345°05 dec. [532°95 grs.]; and its specific gravity is 11°44. As the metals here are only iu juxtaposition, which can neither increase nor diminish their density, their respective proportions may be determined with precision from their specific gravity ; and if we estimate that of platina at 21, and that of copper at 8°87, we shall find by en ae va the vessel is composed of iy Copper++ereeeeerse e+ 0706 Platina. --++cceeeee++0.934, Thus the plating metal is a little more than a fifth, or in the most usual proportion of silver plating, the durability of which is established by use; though the properties of this metal in resisting the actions of heat and saline substances are very inferior to those of platina. XI. Experiments and Observations-on the different Modes in which Death is produced by certain vegetable Poisons; By B.C. Bropiz, Esq. F. R.S. Communicated by the Society for promoting the sere of irre Che- mistry.* a "Tue following experiments were instituted with a view Object of the ‘to ascertain, in what manner certain substances act on. the following ex- periments. animal system, so as to occasion death, independently of ~ mechanical i injury. I was led to the inquiry, from the sub- ject of it appearing to be of considerable interest and im- portance, and from a hope, that, in the present im proved state of physiological knowledge, we might be enabled to ar- _ rive at some more satisfactory conclusions, than had been deduced from any former observations, The substances, which act as poisons when applied to the Confined to animal body, are very nnmerous. In the experiments, — which I have hitherto made, I have employed vegetable poi- * Philos, Frans, for 1811, p.178. sons ACTION OF VEGETABLE POISONS. ‘sons only. Of these Phave selected such, as are very active ist applied to the tongue, or taken inter- nally. Effects of ' alcohol, and certain in producing their effects, believing that, on this account, the exact nature of those effects would be ‘more readily ascertained. "The principal ‘objects, which I have kept in view, have been to determine, on which of the vital organs the poison employed exercises’ its primary ine fluence, and through what medium that organ becomes affected. I have also endeavoured to ascertain by what ineans the fatal consequences of some poisons may be pre= vented. With some of the conclusions, which I have ven- tured to draw, so far as I know, we were not before acs quainted ; and others of them, though not entirely new, had not been previously -established. by oe expe- riments. bi at I shall relate first those experiments, in whieh poisons were applied internally, thatis to the mucous membranes of the tongue or alimentary canal, and afterward those; in which poisons were applied to wounded surfaces, I. Experiments with Poisons applied to the Tongue or ali~ . 3 mentary Canal. Experiments with Alcohol. When spirits. are taken into the stomach, in.a certain quantity, they produce that kind of delirium, which cansti- tutes intoxication: when taken in a larger quantity, It is well known, that they destroy life altogether, and this in the course of a very, short space of time, Intoxication is a derangement of the functions of the mind 5. and, as these are in some way connected with those of the brain, it. seems probable, that itis by acting ov this. organ, that spirits, when taken into the stomach, occasion death. In order to _ascertain how far this conclusion is just, | made. the follow- Li i . es IBS experiments ° * Tam indebted to Dr. E. N. Bancroft for his asststance in many of the experiments, which Iam about to detail, Mr Wy Brande‘lent me his assistance in the greater part of those which were made. I have been farther assisted by Mr. Broughton, Mr. R, Rawlins, and Mr, R. Gatcombe, and by several other gentlemen. i . Experiment - ACTIGN OF WEGETABLE POISONS, 297 Experiment 1. 1 poured two drachms of .proof spirits Experiment 1. down the esophagus of a eat. Instantly he strugeled vio- lently; then lay on one side, perfectly motionless and insen- sible; the breathing was labqured and stertorous, and the pulsations of the beart were very frequent. He continued in this:state for seven or eight minutes; then began to reco, ver; the respirations became easier, and presently he stood up, and was able to walk. Exp. 2. 1 injected an ounce and a half of proof spirits Experiment 2. into the stomach of a large full-grown rabbit, by means of an elastic gum tube passed down the esophagus, The same symptoms took place asin the last experiment; but the animal did not begin to recover from the state of insensi- bility, until forty minutes had elapsed from the time of the injection. | Exp,3. Seven drachms of proof spirits were injected into the stomach of a. younger rabbit. Two minutes after- ward, he evidently was affected by the spirits, and in three minutes more he lay on one side motionless and insensible. The pupils of the eyes were perfectly dilated; there were oc- easional slight convulsive motions of the extremities; the respiration was laborious, it was gradually performed at longer and longer intervals, and at the end of an hour and Experiment 3, fifteen minutes had entirely ceased. Two minutes after the animal was apparently dead, I opened into the thorax, and. found the heart acting with moderate force and frequency, cireulating dark coloured blood. I intreduced a tube into the trachea, and produced artificial respiration by inflating the lungs, and found that by these means the action of the ‘heart might be kept up to the natural standard, as in an ‘animal from whom the head is removed. Exp. 4, 1 injected into the stomach of a rabbit two Experiment 4, ounces of proof spirits. The injection was scarcely com- ‘pleted, when the animal became perfectly insensible. Pre- -eisely the same symptoms took place as in the last experi- ment; and at the end of twenty-seven minutes, from the time of the injection, the rabbit was-apparently dead ; but on examining the.thorax the heart was found'still acting, as in the last experiment. It 208 The brain not Girectly necese sary tothe action of the heart. Spirits act on the brain, and affect it in the same way as external injuries. Do they act by" where ide or sympathy ? ACTION OF VEGETABLE POISONS. ‘It has been shown by Mr. Bichat, and'the observation has been confirmed by some experiments, which I have lately had the honour of communicating to this learned Society*, that the brain 1s not directly necessary to the action of the heart ; and that, when the functions of the brain are destroy- ed, the heart continues to contract for some time afterward, and then ceases only’in consequence of the suspension of respiration, which is under the influence of the brain. Tt would appear from the experiments, which Fhave just detailed, that the symptoms, produced by a large quantity of spirits taken into the stomach, arise entirely from dis- turbance of the functions of the brain. The complete in-— sensibility to external impressions, the dilatation of the pupils of the eyes, and the loss.of motion, indicate, that the functions of this organ are suspended ; respiration, which is under its influence, is ill performed, and at last altogether ceases; while the lreart, to the action of which the brain is not directly necessary, continues to contract, circulating dark coloured blood for some time afterward. There is a striking analogy between the symptoms arising from spirits taken internally, and those produced by inju- ries of the brain. - Coneussion of the brain, which may be considered as the slightest degree of injury, occasions a state of mind resem- bling intoxication ; and the resemblance in some instances is so complete, that the most accurate observer cannot form a diagnosis, except from the history of the case. Pressure on the brain, which isa more severe injury than concussion, produces loss of motion, insensibility, dilatation of the pupils; respiration becomes laboured and stertorous, is per= formed at long Rebel and at last altogether ceases, and the patient dies. It forms an interesting matter of inquiry, whether spirits, when taken: into the ehaerachs produce their effects on the brain by being absorbed into the circulation, or in conse- quence of the sympathy, that exists between these organs by means of the nerves. The following circumstances lead me to conclude, that they act in the last of these two ways. -® See Jougnal, vol. XXIX, p. 359. | 1, In ACTION OF VEGETABLE POISONS, 299 }. In experiments where animals have been killed by the Most probably injection of spirits into the stomach, I have found this organ the latter. to bear the marks of great inflammation, but never found any preternatural appearances whatever in the brain. 2. The effects of spirits taken into the stomach in the last experi- ment were so instantaneous, that it appears impossible that absorption should have taken place before they were pro- duced. 3. A person whois intoxicated, frequently becomes suddenly sober after vomiting. 4. In the experiments, which I have just related, I mixed tincture of rhubarb with the spirits, knowing from the experiments of Mr. Home and Mr. William Brande, that this, when absorbed into the cir- culation, was readily separated from the blood by the kid- neys, and that very small quantities might be detected in the urine by the addition of potash; but, though I never failed to find urine in the bladder, I never detected rhubarb in it. The including the termination of the thoracic dase in a ligature does not prevent spirits, when taken into the sto- mach, from producing their usual effects on the nervous system 5 but subsequent observations, which Mr. Home has already communicated to this Society*, have shown, that no conclusion can be drawn from this experiment. _ That a poison: may affect a distant organ, through the ., boi sod medium of the nerves, without entering the circulation, is entering the proved by the well-known circumstance of solution of the “culation. extract of belladonna, when applied to the tunica conjunctiva of the eye, occasioning dilatation’ of the pupil of the same eye, though yo other part of the system is affected. It has been formerly supposed’ by Dr. Mead and other Supposed ca- Selansiebieibes: that a poison may produce death by acting on ee a the extremities of the nerves of the stomach and intestines, this way. : without being absorbed into the circulation. That it should by these means be capable of affecting the brain is not to be wondered at, when we consider the numerous and various sympathies between this organ and the alimentary canal, evidently independent of any other communication than the nerves. * See p. 173, of our present vol. Experiments 300 ACTION OF VEGETABLE POISONS. _ Experiments with the Essential Oil of Bitter Almonds*. . Effects of : Experiment 5. ‘One drop of the essential oil of bitter £ bitter ale , i taiac. almonds was applied to the tongue of a young cat. She was Experiment 5. mstantly seized with violent convulsions; then lay on one side motionless, insensible, breathing in a hurried manner ; the respirations became laboured, took place at longer and longer intervals, and at the, end of five minutes, from the application of the poison, had entirely ceased, and the ani- mal was apparently dead ; but, on opening the thorax, the heart was found acting regularly eighty times in a minute, circulating dark ‘coloured blood, and it continued to act for / §ixor seven minutes afterward. Experiment 6. Hyp, 6. 1 injected ‘into the rectum of a cat half an ounce of water, with two drops of the essential oil. In two minutes afterward, he was affected with symptoms similar to those, which occurred in the last experiment ; aid at the end of five minutes, fromthe injection of the poison, he was. apparently dead. Two minutes after apparent -death, the heart was found acting eighty times in a minute., On dis- section, no preternatural appearances were found either in the interna! membrane of the rectum, or the brain. Appears to act Thesymptoms produced by this poison, and the cireum- ga the bain stance of the heart continuing to contract after apparent death, lead to the adaaelaa tal that. it occasions death by disturbing the functions of the brain. Effects of a While ‘enepucd in these last experiments, I iiorih the pA: cna blunt end of a probe into the essential oil, and applied it to tongue. my tongue, meaning to taste it; and having no suspicion, that so small a quantity could. produce any of its specific effects on the nervous system ;_ but scarcely had I applied it, when I experienced a very remarkable and unpleasant sen- sation, which I referred chiefly to the epigastric region, but the exact nature of which I eannot describe, because I know nothing precisely similar to it. At the same time there was a sense of weakness in my limbs, as rf I had not * * Theessential oil of bitter almonds dees not appear to differ from the essential oil of laurel. I was furnished with a quantiry of it, first by my friend Mr, William Brande, and afterward by Mr, Cogke of Southamp- ion street, the ACTION OF VEGETABLE POISONS. SOi the command of my muscles, and I thought that I was about to full. However, these sensations were momentary, and | experienced no inconvenience whatever afterward. lafterward applied a more minute quantity of the essen~ tial oil to my tengue several times, without experiencing from it avy disagreeable effects; but on applying a larger quantity, { was affected with the same momentary sensations as in the former instance, and there was 2 recurrence: of them in three.or four seconds after the first attack had sub- Rided. From the instantaneousness, with which the effects are Acts through the medium of produccd ; and from its acting more speedily when applied the nerves. to the tongue, than when injected into the intestine, though the latter presents a better absorbing surface; we may con- clude, that this poison acts on the brain through the medium of the nervés, without being absorbed into the circulation. Experiment with the Juice of the Leaves of Aconite. Exp.7. An ounce of this juice was injected into the rec peracts of the tum of a cat. Three minutes afterward he voided what ap- juice of peared to be nearly the whole of the injection; he then eat my stood for some minutes perfectly motionless, with his legs drawn together ; ; at the end of nine minutes, from the time of the injection, he retched and vomited; then attempted to walk, but faltered and fell at every step, as if from gid- diness. At the end of thirteen minutes, he lay on one side ‘insensible, motionless, except some slight convulsive mo- ‘tions of the limbs, The respiration became slow and Ja- boured ; and at forty-seven minutes from the time of the Injection, he was apparently dead. One minute and a half afterward, the heart was found contracting regularly one | hundred times in a minute. It appears from this experiment, that the juice of acoe jac iaa nite, when injected into the intestine, occasions death by similar way. ‘destroying t the functions of the brain. ‘From the analogy of other poisons, it is rendered probable, that it acts on the “brain | through the medium of the nerves, without being, ab- . sorbed into hee circulation. This opinion is confirmed by the following circumstance; if a small quantity of the leaf Effects of of aconite is chewed, it occasions » (a remarkable sense of ae the numbness 302 Effects of to- bacco. Experiment &. Experiment §.° ACTION OF VEGETABLE POISONS. numbness of the lips and gums, which does not subside for two or three hours. - Experiments with the Infusion of Tobacco. Exp. 8. Four ounces of infusion of tobacco were injected into the rectum of a dog. Four minutes afterward he retched, but did not vomit ; he then became faint, and lay motionless on one side; at thé end of nine minutes from the: ‘time of the injection, the heart could not be felt ; he gasped for breath at long intervals: and in another minute there was no appearance whatever of life. I immediately laid open the cavities of the thorax and abdomen. The heart was much distended, and had entirely ceased ‘to contract ; ; ‘there was no peristaltic motion of the intestines, Exp. 9. An ounce of very strong infusion of tobacco was injected into the rectum of a cat. Symptoms were pro- duced similar to those, which occurred in the last experi- ment, and the animal died at the end of seven. minutes from the time of the injection. On opening the thorax imimedi- _ ately after death, the heart was found extremely distended, Exp. it. and to have entirely ceased acting, with the exception of a slight tremulous motion of the ariclee Exp.10. Three ounces of infusion of tobacco were in~ jected into the rectum of a dog. He was affected with symptoms similar to those in the former experiments, and “died at the end of ten minutes. On opening the thorax im- ‘qediately after death, I found the heart much’ distended, “and to have entirely ceased contracting, © Exp. 11, Three ounces of infusion of tobacco were in- jected into the rectum of a dog. Immediately there tock place tremulous contractions of the voluntary muscles. Five mivates afterward the injection was repeated in the same quantity. Thedog then was sick, and threw up some of the infusion, with Oe matter, from the stomach ; he became faint, and died ten minutes after the second i injec- tion. Immediately after respiration had ceased, I opened “the thorax, and found the heart extremely distended, and without any evident contraction, except of the appendix of the right auricle, which every now and then contracted i ir~a slight degree. I divided the pericardium on the right side. 2 In- ACTION OF VEGETABLE POISONS. 303 In consequence of the extreme distension of the heart, this could not be done without irritating the fibres with the point of the scalpel. Immediately both auricles and ven- tricles began to contract with considerable force, so as to re- store the circulation. Artificial respiration was produced, and the circulation was kept up for more than half an hour, a, which time the experiment was not continued. We may conclude from these experiments, that the effect It destroys the cua infusion of tobacco, when injected into the intestine of oe aby a living animal, is to destroy the action of the heart, stop- ping the circulation and producing syncope. Itappeared te me, that the action of the heart ceased, even before the ani- mat had ceased to respire; and this was confirmed by ano- _ ther experiment, in which, in a dog killed by the infusion of tobacco, I found the cavities of the left-side of the heart to contain scarlet blood, while in those of the right side the blood was dark coloured. This poison therefore differs mas terially from alcohol, the essential oil of almonds, and the juice of aconite, which have no direct influence on the action of the heart. The infusion of tobacco renders the heart in- sensible to the stimulus of the blood, but it does not altoge- - ther destroy the power: of muscular contraction, since the heart resumed its action in one instance on the division of the pericardium ; and J have found, that the voluntary mus- cles of an animal killed by this poison are as readily stimu- lated to contract by the influence of the Voltaic battery, as if it had been killed in any other manner. At the same and aise of the time, however, that the infusion of tobacco destroys the ac- een tion of the heart, it appears to destroy also the functions of the brain, since these did not retarn in the last experiment; although the circulation was restored, and kept up by artifi- cial respiration. Since there is no direct communication between the intes- Its absorption tinal canal and the heart, I was at first induced to suppose, >¥ te oe that the latter becomes affected in consequence of the infu- Pee, sion being conveyed into the blood by absorption, Some ‘circumstances in the following experiment have since led ime to doubt, whether this is the case. Exp. 12. Ina dog, whose head was removed, I kept up Exp. 12. ‘the circulation by means of artificial respiration, in theman- £4 ner SO: Remarks on the pheno- Feena. ACTION OF VEGETABLE, POISONS, ner already described in the account of some. experiments, which I lately communicated to this Society. I then in- jeeted into the stomach and intestines nine ounces of infuse sion of tobacco. At the time of the injection, the body of the animal lay perfectly quiet and, motionless on the table; the heart acted reeularly que hundred.times in a minute. Ten minutes afterward the pulse rose to.one hundred and forty in a minute; the peristaltic motion of the intestines was much increased, and the voluntary museles im every part of the body were thrown inte repeated and violent spas- modic action, The joints of the extremities were alter- nately bent and extended ; the muscles of the. spine, abdo- men, and tail alternately relaxed and contracted, so as, to turn the whole animal from one side to the other. 1, have observed, in other instances, spasmodic¢ actions of the mus- eles, where the circulation was kept. up by artificial respira= tion, after the removal of the head; but not at all to be compared, either in strength or. frequency, with. those, which took place on, this occasion. 1 made pressure.on the abdominal acrta for more than a minute, so as. to, obstruct the circulation of the blood in the lower extremities; but the muscular contractions were not lessened in consequence, Half an hour. after the injection of the infusion, the artificial respiration was discoutioued. The heart continwed to; act, circulating dark coloured blood; the muscular contractions continued, but gradually diminished in strength and fre- quency. ‘Ltieda ligature.round the vessels at the base of the heart, so-as.to stop the circulation, nevertheless the muscular contractions still continued, though less frequent and forcible than before, and some minutes elapsed before they entirely ceased. Biielnoy In this experiment, the disposition to contraction in the muscles was very much. increased, instead of being’ dimi- nished, asin those just related. Ifthe infusion of ‘tobacco influences the heart from being absorbed into the blood, and thus coming into actual contact with its bres, there is no evident reason, why the removal of thé brain, and the em- ployment of artificial vespiration, shéuld ‘occasion’ so mate riala difference in its etiects. If the contractions of the yo- loutary ra hadwdepended on the infusion circulating with oe ACTION OF VEGETABLE POISONS. S05 with ‘the’ blood, it is reasonable’ to suppose, that the pres~ _ sure on the aorta would have occasioned some diminution of them, and that the complete obstruction of the circulation would have caused them to cease altogether. From these considerations, Iam induced, on the whole, Appears to act to believe, that the infusion of tobacco, when injected into Segre the intestines, influences the heart through the medium of the nervous system ; but I have not been able to devise any experiment, by which the truth or fallacy of this opinion might be put beyond the reach of doubt. It appears remarkable, that the brain and nervous systein| affecting it although not necessary to the action of the heart, should, fully. al while under the influence of the infusion of tobacco, be ca- pable of influencing this organ so as to stop its action; but _this isanalogous to what we see occur in consequence of vio- - lent emotions of the mind., Those states of the nervous system, which accompany the passions of joy, fear, or anger, when existing in a moderate degree, render the heart more sensible to the stimulus of the blood, and increase the fre- quency of its contractions; while, when the same passions exist in a greater degree, the heart is rendered altogether in- sensible to the stimulus of the blood, and syncope ensues. ie Experiments with the Empyreumatic Oil of Tobacco*. Exp. 13. Less than a drop of this oil was applied to the Effects of em- tongue of a young cat. Instantly violent convulsions took: Saag oil place in all the muscles, and the respirations became very’ Exp, 18. frequent. In five minutes after the application, she lay on one side insensible, with slight spasmodic actions of the muscles.» At the end of eleven minutes, she retched, but _ did not vomit. Ina quarter ofan hour, she appeared to be i recovering. 1 repeated the application of the poison, and ~ _ she was again seized with violent convulsions, and became -insensible, breathing at long intervals, and in two minutes from the second application respiration had‘entirely ceased, _and she was apparently dead. On opening the thorax, I * 1 was furnished with the empyreumatic oil of tobacco by Mr. W. : Brande. It may be procured by subjecting the leaves of tobacco to dis. tillation in a heat above that of boiling water: a quantity of watery fluid . comes over, on the surface of which is a thin film of unctuous substance, “Vou. XXX,—DEc. 1811. x found to (2) a Acted like the ACTION OF VEGETABLE POISONS. found the heart ‘acting with regularity and strength, cirei’ lating dark-coloured blood. T introduced a tube into the trachea, and produced artificial respiration; the contrac- tions of the heart became : augmented in force and frequency, atid theré'waé ho'évident diminution it six or seven minutes, during which the artificial respiration was continued. On dissection, nothing remarkable was found 1 in the « ap- ali of the tongue or brain. ‘The symptoms and mode of death, in this eaeninr, | essential oil of did not essentially differ from those produced by the essen- almonds, Exp. 14. | Exp.15, tial oil of almonds. Iwas surprised to find the effects of the empyreumatie oi] so entirely different from those of the infusion of tobacco. Supposing that this difference might arise from the poison being more concentrated ‘in ‘the ‘oil than in the infusion, I rhade the following experiments, i: “Evp.14,. A drop of the oil of tobacco was suspended in an ounce and a half of water by means of mucilaye of gum: arabic, and the whole was in} ected into the rectum of a dog. In two minutes afterward he became faint, retched, but did not vomit. He appeared to be recovering from this state, and in twenty-five minutes after the first injection, it was ye- peated in the same quantity ‘He! was then seized with symptoms similar to those in the last experiment, and in two minutes and a half he was apparently dead. Two minutes after apparent death, on the thorax being opened into, the heart was found acting regularly one» layer: dred times in a minute, and it continued acting for several minutes. i2 A> oh iQ Exp. 15. A drop of the empyreumatic oil of sient with an-ounce of water was injected into the rectum of a cat.: The symptoms produced were im essential circumstances si- milar to those, which occurred in the last experiment, The animal was apparently dead in five minutes after the injec- tion, anid the heart continued to contract for several minutes afterward, et We may conclude from these experiments, that the em-' pyreumatic oil of tobacco, whether applied to the tongue, or injected into the intestine, does not stop the action of the heart and induce syncope, like the infusion of tobaceo; but that it occasions death by sna aha the functions.of the - Y’ a 3 * ony brain ANALYSIS OF A CHINESE GONG. 307 brain, without directly acting on the circulation. In other words, its effects.are similar to those of alcohol, the juice of aconite, and the essential oil of almonds. (To be concluded in our next.) Ladd ssi! prewar c ~ fats ofa Chinese COMP by Mr. Kiaprotu*. Aone: sonorous instruments the composition of COp- Sonorousness per with tin gives the loudest sound. Bells, we know; are of bell metal. composed of this alloy. The celebrated bell of Pekin, the largest-in the World, which is twenty feet in diameter, and the inches thick, is no doubt cast of it. The Chinese frequently use another kind of bells too, The Chinese which are not cast, but hammered out. These instruments, 8°"8: called gongst, are not shaped like a common bell, but like a ‘shield with the edge turned up: and give an astonishing sound when struck: Barrow, in his voyage to China, says of these instruments; that they are like flat pots, or rather potlids; that they are struck with a stick wrapped round with leather; and that they are supposed to be formed of copper, tin, and bismuth. The thickness of this alloy is about that of the back of a Analysis of it. knife ; ‘its colour is a brouze yellow; and its spec. grav, 8'815. A hundred and fifty grains were heated with nitric acid ; ~and 42 g ars of oxide of tin separated ; answering to33 grs of . ‘pidtalic tin. . Into the filtered liquor sulphuric acid was poured, and ve Mixture was evaporated todryness. The residuum being issol¥ed in water, iron precipitated from it 117 grs of copper. The gong therefore i is composed of Copper -+-+++ 78 — Its composi- : Til coe ccc alee o2 tion, eee 100. The ance of emitting a sound that can be heard so far Cause of its a depends on the mutual penetration of the metals, and the loud sound. greater density of the alloy, which is farther increased by ip a Perhaps too the form of the instrument con- » dributes to this. sof Ann. de Chim. vol. LXXv, p.. 222, 4 Tshoung, in the Chinese language, signifies a bell. x 2 XII. 308 Nil. METEOROLOGICAL JOURNAL... Punssune, "| LEMPERATURE, Wind| Max. Min. Med. |Max-.| Min ao Evap. Rain 10th Mo, Ocr. 9 |S WJ 30°00} 29°99} 29:995| .67..| 54 | 60°5 10:)5, W |.29°99] 29°77] 29°880} 63 | 57 | 60°0 . 11 |S WI 29°77 | 29°60] 29°685| 65 | 51 | 58°0 12] S |°29°80}' 29°60 29°700) 62 [* 48°17 '55°0 | “407° 13 |S W] 29°901 29-86} 29°880} 62 | 49 | 55°5 | —]'-03) 14| S | 29°86} 29°81}-29°835| 63 |.61 | 57-0 |>o—) OL (154 Syife 29°76 | 29-75 | 29°755| 73; | 53] 63:0] *33) 16 | _S..|.30°03,] 29:76) 29°893}.70.4.°55. | 62°5 |. —] 17 [Var.| 30°10} 30:03 | 30°65). 71 | 47 | 59°0. |. —| .. |@ 18 |S W| 30°16] 30°10] 307130} 68 |'50 | 59°0 | —]°11 19 |Var.| 30°21 | 30°18] 30°195} 65° | 49 | °57°0™ 20 |S W} 30°05} 29°96} 30° 005) 64455 | 595" 21 |S WI 29°96} 29:50 | 29'730).65: P56 | 60:5..).2 22}. S. |,29:52} 20°46 | 29:490! 64 |.50 ) 57:0: lo 23 |S W{| 29°50] 29-48} 29°490;) 60 | 49 | 545 | — i 24 \Var.} 29°48] 29°35 | 29°415] 57-] 42°] 495 | -20]' 087 251 S§ | 29°35} 28°65] 29°000) 53 | 38 | 45°5 | —] “18 26 [Var.| 28°80] 28-65 | 28°725)' 54°] 41] 47°75 | ers} 232 27 1S Bp: 28Sk} 2881 | 28°S25] 56/} 43] 49°5 | hdd 28 |Var.| 28°84] 28°S0 | 28:820] 56 | 41 | 48°5, | +15] 744 29 |S W| 29°05} 29:00] 29°025| 55 | 43 | 49°0 | -02] .18 30 Var.| 29°55} 29°00] 29°275| 58 | 43 | 50°5 311.W |} 29°77) 29°68) 29°725| 59 | 48 | 53°5 11th Mo. me Nov. 1 /S W] 29°68 | 29°62] 29°650) 62 | 57°] 59°5 24S WI 29°58} 29°50] 297540] 62 | 53 | 57°5 3/5 WI] 29°70] 29°60} 29650) 58 | 48 | 53°0 4| W } 29°98} 29:80} 29-890} 60 | 42 | 51°0 51S WH 29°89] 29°83 | 29°860) 5 43 | 49°5 61S Wi 29°83} 29°52] 29°675] 53 | 45 49°0 —_—- [| | eS | N.B. The observations in each line of the Table apply to a period of twenty- four howrs, beginning at 9 A.M. on the day indicated in the first column. A dash denotes, that the result is ine! — in the next following observation. NOTES. METEOROLOGICAL JOURNAL. 309 NOTES. Tenth Month, 12. Windy: weteyening. 13. Much wind. +14. A shower before ‘nine a.m. at which time occurred the max. of temp. 15 Much dew on the grass: serene day: twilight milky, with converging streaks of red. 16. a m. Much dew: a Lite 7 ‘ mist on the river: the smoke of the city remarkably depressed, and sounds unusually strong from thence: some thunder clouds appeared and passed to E. 17. Cumulus clouds surmounted with cirrostratus, and cirri above. 18. A very wet mist a.m. wind N.W.: at two p.m. cloudy; very moist air, the dew point (ox temperature at which a body colder than the air coudenscs water from it) being 63°: about sunset, at temp. 63°, I found dew just beginning to be deposited on the grass: it raiued hard about five next morning. 19. a.m. Misty,smallrain: p.m. clear: evening, cirri very elevated, and long coloured red; a stratus forming. 20. Misty: then overcast: the wind, which had been E., veering by S.: abuudance of gossamer... A quicken-trea {sorbus aucuparia) exhibits a new set of leaves and blogsoms along with the ripe berries: 21. Gray morning, with little dew and astrong breeze. 22. a. m. Dew scarce percep- tible: wind veers to S., 2 breeze: p.m. very cloudy, with showers: much wind at night. 24. At mid day a drizzling rain, dmring which the vaneturned to E. 95. Clear, fine day: wind veered tu S.: at sunset nimbi and cirrostrati inS. W.: heavy shower byeleven p.m. 926. Showery: a fine rainbow at ten a.m. 97. a.m. Nimbi in different quarters, mixed with cumulus and cirrostratus, beneath large plumose cirrus clouds. 28. a.m. Clear, muclidéw, nimbi forming amidst various clouds: vane at N. E.: p.m. ashowerintheS., during which appeared, fora short time, a numerous flight of swallows: they had been last observed on the 15th: the wind returned by S. to N. W. with much cloud and rain. 30. At nine a.m. the rain intermitting, the highest and most considerable mass of clouds was moving from W. an intermedi; ate portion from S., and the wind below fresh at E.: in this state of things sounds came very freely from the westward, and by eleven the wind was S. W.: at three p.m. distinct nimbi and a bright bow: showery at night, with alunarhalo. 31. a.m. . Clear: the sun and muon appeared red on the horizou: at night, the wind being S. sounds came loud from the W. : ‘ Eleventh Month. 1. a.m. Much cloud: wind fresh at S.W. 9 As yestezday : stormyat night 3. Arainbow at eight a.m. 4. a.m. Nimbi to windward: at sun. set, the dense clouds in the E. finely coloured: rainbow: wind W. 5. a. m, Stormy : p.m. wet. 6. Cloudy, showery : evening, abundance of cirrostratus; a wet night. i j TT ge > RESULTS. * Barometer: highest observation 30°21 inches; lowest 28°65 inches; range 1°56 inches. ee on . Mean of the period 29-614 inches. Thermometer: highest observation 73°; lowest 38°; range 35°. ee 5 Mean of the period 54°86°. Evaporation 2°44 inches. Rain 3-05 inches. Wind with little exception S.W.andS, The fore part of the period changeable; the latter wet, without the usual intervening frosty nights. | . L. HOWARD. Prarsrow, Eleventh Me, 20, 1811. eis. ee f a f ' 310 -' -ANALY8IS OF THE YELLOW GUM. XIV. Chemical Examination of the yellow Resin of the Xan- thorrhaa hastilis, and of the resinous Cement employed by the Savages of New Holland to fix the Stone of their FTatchets: by Mr. A. Laveter.* Yellow gum "Tue following remarks on the resiy of the xanthorrheea, am Botany ond the tree that produces it, which } Mr. Peron has been so obliging as to communicate to me, will form a very suitable introduction to the experiments I shall relate, and enhance their value. . The tree. ‘The resin in question,” says Mr. Peron, “ exudes natu- rally from the bark of a tree peculiar to New Holland, and of which Dr. Smith bas made a uew genus, under the name of xanthorrhea hastilis; thus intending to express in one term the colour of the resin of this strange tree, and in the other the use, which the natives make of its shoots for yer spears. i } Tts name ave It must be observed however, that Dr. Sinith’s generic EA ia name is not strictly accurate ; as the fesin is very fAinneetiy brown, red like dragon’s blood, green, &c. Heice “the different names of yellow, red, green, &c., gum plant, or gum tree, given almost indiscriminately to the xanthorrlic@ea by the English at Port Jackson. Whether thése varieties of colour indicate so many species, or varieties, of the tree that produces them; or depend merely on the age or other circumstances of the individual tree; has not yet been ascertaincd. Probably seye- ‘* Hitherto botanists have admitted only one Species of ral species. yanthorrheea, the hastilis, just mentioned : but as trees of this kind are found throughout the various parts of New Holland, an extent of country equal to all Europe, it is very probable, that several species exist. Phillip’s de- «* Governor Phillip,. in his voyage to Botany Bay, igo and», 60, and plate to p. 119, has given an incomplete descrip- indifferent, tion of the xanthorrhcea; and a figure, which, though not very carefully executed, 1 is sufficient to afford an idea oF this extraordinary tree. : ’ * Ann, de Chim, vol, LXXVJ, p 265. ' , , ee [t ANALYSIS OF THE YELLOW GUM. 31] ** Jt is particularly abundant at Geographer’s bay, Leu- Its soil, win’s Land, and in the environs of Botany Bay ; and ap- pears to prefer a sandy and barren.soil. The shoots, which and growth. the savages use for their spears, extend to the length of three, four, or even five yards; and are nearly of the same size, | which is scarcely equal to that of the thumb, throughout their whole length. « Each of these shoots terminates in a kind of spike, or Produces ear, of a larger size, and from fifteen to twenty four inches * *¥°t itice. long; from the surface of which exudes a kind of viscous liquid, of a pleasant sacharine taste, and a strong aromatic smell. The-savages are very fond of it; and I found it, on tasting it, to be as I have described. ‘To procure these tops of the xanthorrhaea, the natives have recourse to their clubs [easse-t¢te], which they throw with such strength and skill, that they are sure to cut off the ear at what length they please at the first stroke. / . The resin flows naturally from the trunk of the tree, The resin, making its way through the bark. The portion of the stem, that is buried in ‘the sand, appears to furnish the greater part ; at least large pieces are found in the sand; apparently ; _ still adhering to the bark. Some of these pieces are re- markable for the perfect regularity of their spherical form. | «© The English employ this resin against dysentery, for Its uses. which they esteem it an excellent medicine. The savages use it for many domestic purposes, and particularly for ce- menting the points of their gpears to the shaft. With this substance too they prepare the celebrated instrument, that serves to discharge their spears; also their fishing imple- ments, their stone hatchets, &c. They likewise employ it to unite the lips, of wounds, however large or dangerous they may be; and I have seen some healed in this way by the first intention, that have appeared to me truly extraor- dinary. « ; _. & The wood of the xanthorrhcea, when burned, emits a The wood fia- smell which is very pleasant, at a little distance from the g'@n when fire, but seemed to me too powerful if inhaled nearer, montis _ Such indeed is the odoriferous strength of this wood, that you may sometimes discover a party of savages more than a quarter 312 Probably the eagle wood of Badia, Physical pro- perties of the yellow resin. ' Action of heat on it. Action of alcohol. The tincture ANALYSIS OF THE YELLEW GuM. quarter of a league [half a mile] distant ps oy the seme it emits in burning. “© Mr, Martin-Moncan, formerly agent of the French go- vernment to Hyder Ali Khan, told me, on seeing a piece of the xanthorrhea, and smelling to it, that it very much resembled the celehrated eagle wood, which fetehes such a high price in India, and the country of which is hitherto unknown to Europeans. Mr. Martin-Moncan considered itas by no means impossible, that the Malays, who in’ fact have long had a commercial intercourse with New Holland, visit its coast to procure the wood of the xanthorrheea, which le believes to be the eagle wood itself.” © The resin of the dundee is friable and sity sepa~ rates into scales before the nail, Itsfracture is shining and compact. It has a yellow colour, and a very pleasant: rtbal. samic smell, resembling that of poplar beds. When yubbed in a mortar, it clots, and adheres toit strongly. It is rendered very perceptibly electric by friction. The paper on which tt has been put when powdered retains enowgh of it to acquire a deep yellow colour, whieh ‘cannot! be ‘Te- moved. Exposed toa gentle heat, it ervelhnys swells up, styles ‘outa | considerable portion of aqueous vapour, diminishes in bulk, and aequires a brownish red colour inclining to purple. Placed an burning coals, it rises in dense fumes, very pun- gent, and so strongly aromatic as to be disagreeable ; and soon after it flames, swells wp considerably, and: wineries a very bulky and very heht coally residuum, As this substance dues not mix with water, andi fetephaies to it no colour, acting in this respect as a resin, | employed for analysing it alcohol at 40° [sp. grav. 0°817], which dis- solyed it with the greatest facility, and without the assistance of heat. Nothing was left undisvolved but 0-07 of an in- sipid, grumous substance, resembling a gum, and particu- larly that which is called 1 the shops gum of Bassora, for it is neither soluble nor diffusible 1p water, it is only soften- ed and swelled up by the action of this fluid when boiling.» . The alcoholle solution when filtered has a reddish colour, partly precipi- par: is remarkable for its limpidity and pleasant smell. It pres by reels vmay be kept several months without undergoing any alteras tion ANALYSIS OF THE YELLOW GUM. 313 tion. » Water renders it turbid, and occasions a precipitate, but a portion of the resin remains suspended, without being separable either by heat or standing; so that the mixture resembles 2solution of gum-resin. 1f however it be heated long. enough to evaporate the alcohol, and about three fourths of the liquid, almost all the resin is deposited on the bottom and sides of the vessel, and the portion more mi- nutely divided unites on cooling into little tifts of a lemon «colour. The mixture in this state has a more pleasant and @elicate smell than the resin itself, and some compare it to that of storax. a The water separated from the resin was still turbid, or a Benzoic acid little coloured, and reddened vegetable blues. In order to Obteined from ee ; the water. fix the acid it contained, I had recourse tothe process, which employed with success in my analysis of the sub- stance found in the grotto of Arc, and of castor, to obtain 4rom it the benzoic acid: I added a few drops of caustic potash, and l evaporated to dryness. The residuum, which vesembled a kind of brown red extract, was distilled with a little sulphuric acid diluted with water, and toward the end of the process I obtained a few small crystals, which had the characteristics of benzoic acid, . These small crystals I diffused in the acid and aromatic water in the receiver, and supersaturated the mixture with dime quenched in the air. After evaporating to dryness, I poured on the residuum a small quantity of cold water, to take up the benzoate of lime, and separate it from the sulphate and carbonate of this base, which were mingled with - it. Into the filtered and concentrated liquor 1 poured mu- wvatic acid, which produced in ita slight precipitate of ben- goic acid in the form of small granular crystals, But I found, that the most sunple and ready mode peagier mode of distinguishing the presence of this acid in theyellow resin of obtaining was, to expose this substance to a heat sufficient to keep it thigiasid an fusion, | Lintreduced the powdered resin-into a very dry wessel, which I placed ona sand-heat:; and as soon as the resin was melted aqueous vapours first rose; and soon after white fumes, which condensed on the sides in small shining seaies, exhibiting all the characteristics of benzoic acid. eooAs:'the acid is expelled, the resin first swells up: after Bicis Ras which 314 The resia dis- tilled with water yielded a hot aud fragrant oil. ANALYSIS OF THE YELLOW GUM. which tt collapses, and diminishes in bulk. In this state it is of a deep brown colour, which appears purplish whea placed between the eye and the light. ‘The alcoholic solution also yields.a few crystals of benzoic acid by distillation to dryness, though not so easily. The aleoho! distilled from it reddens litmus paper, which shows, that it probably carries off a portion of the sameacid, I introduced 30 gfaius of the yellow resin into a retort with four ounces of distilled water, fitted to it a receiver, and distilled on a sand-heat.. The water, that, passed into the receiver, was turbid, on account of the suspension of a certain quantity of essential oil, several drops of which col- lected on the surface. The water thus mixed with: oil, had an extremely pleasant smell. The extremity of the beak of the retort was soiled with this oil, which had an. acrid: and ‘ burning taste nearly like that of the oil of cloves. When This ot} ob- tained from the tncture, The resin forms a soap with alkalis or lime. The benzotc acid not ob- tainable from this. The resin the matter remaining in the retort was dry, white) fumes arose, that condensed in the head of the retort in small and very white crystals, which powerfully reddened litmus paper, and had the strong and pleasant smell of ‘benzoic acid. widny oul The essential oil of the yellow resin may nt site also by distilling the alcoholic solution: the alcohol, that passes over into the receiver, being insensibly impregnated with it ; so that the evaporation of this hquid. by a gentle heats suf- ficient to procure this acrid and pleasant substance. Caustic alkalis, or lime, placed in contact with the yellow resin, immediately assume a deep yellow colour, without the assistance of heat; and dissolve the resin. completely, i¥ they be employed in sufficient quantity. The solution froths when shaken, like that of soap, and lets fall a yel- lowish white precipitate on the addition of an acid. I had hoped, that this solvent action of the alkalis would furnish me with an ‘easy mode of separating the benzoic acid frem the resin’; but several trials convinced me of the impossibility of succeeding. Itappears, that this acid falls down at the same time as the resin, the moment another acid isadded to the mixture. Thirty grains of the yellow resin in powder being heated in a retort with six times the weight of nitric acid, a consi- derable ANALYSIS OF "THE YELLOW GUM. 315 ‘derable evolution of nitrous gas was produced, and: the fe- treated with sin was completely aiiobieda The liquor remaining in the bei retort deposited by cooling a crystalline substance; and both the mother-water and the crystals were of a deep yel- low colour, a very bitter taste, and a smell of bitter almonds. A portion of the mother-water being saturated with potash, it did not emit any sensible ammoniacal smell; but being mixed with a selution of sulphate of iron, and supersaturated with concentrated sulphuric acid, it let fall in the course of the nighta considerable quantity of Prussian blue. Ano- ther portion.of the same mother-water yielded on evapora- tion thin erystals several lines square, which might be known foroxalic acid. Their solution precipitated lime-water, and : the calcareous salts.. : /oiFrom the experiments I have related it appears, that the Conclusions, | yellow substance, which flows from the xanthorrhea, is com- posed of a large portion of resin, combined with a few hun- dredths of a kind of spongy gum, insoluble in water, of ben- ‘zore acid, and of a very acrid, yellowish volatile oil, very pleasant to the smell. The yellowish substance of the xanthor rian then cannot It is properlya be considered as a resin, properly so called; since it differs mie from resins in containing benzoic acid, to which it is in- -debted at least in some measure for its pleasant smell; and -on this account it seems to belong rather to the balsams, -than to the resins. What struck me most in the examination of this yellow Resembles ‘substance is its resemblance to that matter, which the bees P'°P's: vemploy for stopping cracks in their hives, and to which the name of propolis has been given. 4 .. This resinous, odoriferous matter, when separated froin the wax, by which its properties are concealed, exhibits the ‘characters of the yellow substance; and, if subjected to the ‘same processes, comports itselfin the same manner. - ‘It is considered by naturalists as ascertained almost to a The resin on demonstration, that the resinous matter, which covers the gaa buds of poplar trees, and preserves them from moisture, is -that which the bees so carefully collect, to form their propo- ‘lis. . The smell of this matter, which is precisely the same -with that of the propolis, strongly supports this opinion. vais The 316 A cement of great strength’ «ade with this resin, his cement analysed. ANALYSIS OF THE YELLOW GUM. The smell of the yellow substance too is similar to that of the poplar buds : and, if we cannot hence infer its perfect identity with propolis, it is at least certain, that the differ- ence between them is too trifling to admit the supposition, that bees could not employ the yeliow substance for the same purpose. This conjecture, however, might easily be verified in countries where the tree that produces it so abundantly grows. r The resin T have just analysed entersinto shes Semeniition of a cement, which the natives of New Holland employ for fixing the stone of their hatchets to the handle, and for ses curing the points of their spears. This cement is capable of acquiring such hardness, that the hardest substances can- not separate it, or even loosen the stone fastened by it. , Its colour 1s a deep brown; and on rubbing it emits a fragrant smell, which does not differ from that of the yellow resin, _ I satisfied myself of the complete identity of this cement with the yellow resin by examining a sufficient quantity of — it, taken from a hatchet brought home by Mr. Peron, and which her majesty, the empress Josephine, deigned to ac- cept from that navigator, as a valuable proof of the indus- try of the natives of Nuyts’s Land. A bundred parts of the brown powder furnished by the cement were digested in alcohol at 40° [sp. gr. 0°817]. Two portions of this liquid added in succession were sufficient to take up all the resin, that the cement contained. What re~ mained after the action of the alcohol was nothing but a blackish gray powder, without smell or taste. The weight of this residiuym was 51 parts, so that the alcohol had taken up 49. The alcoholig solution babs a deep red colour, at was exactly similar to that obtained by macerating in the same menstruum the yellow resin, after it had been melted and turned brown by heat. On evaporation it yielded a red resin, which had all or characters of the resin of the xan~ thorrheea, On: the 51 parts not dissolved by the alcoho! 1 boiled to dryness asmall quantity of nitric acid, which caused the re- siduum to acquire a redness like that of oxide of iron, and j treated this residuum with muriatic acid, After the ace tien ANALYSIS.|OF THE YELLOW GUM. tion of this acid, the residuum, being 37 parts, was a white, dry powder, rough to the finger, and resembling fine sand. Ammonia, poured into the muriatic ilies separated 7 parts of oxide of iron; and oxalate of ammonia produced a precipitate equivalent to 3 parts of lime. “This chemical examination shows, that 100 parts of the resinous cement are formed of Be i ee 49 Ver 4 PPuresand’ecciscennecesccendese 37 ADEA OF ALOT (o:<. 9:6 010 wo bie diese caw DLN . o'9 eo cg sewic cece cued vision 7 3 Less : POTOCC OHH OES LeEPer2re0e0e8 4 100 iy, appears, that necessity has taught the natives of New ‘Holland a practice, which engravers employ every day. It has taught them, to mix a proper quantity of sand with the yellow resin kept some time in fusion, and thus te compose a cément capable of acquiring considerable hardness. “This i is the mode in which the resinous cement, called in the shops engravers’ wax, 1s prepared, Brickdust is added to common resin: the mixture is melted, and cast in moulds: and thus it is formed into red cakes, which are sold to the engravers. I have satisfied myself, that, the oftener this mixture has been melted, the harder it is. I examined engravers’ wax in comparison with the ce- ment of the savages of New Holland; and 1 observed with surprise, that the proportions of resin and. brickdust were precisely the same with those of the yellow resin and sand in the cement I analysed. $17 Its compenent parts. Similar i eh - Gravers Wak, ‘It appeared to me, however, that the engravers’ wax, put harder. though very hard, particularly when it has been melted se- veral times, is inferior in solidity to the cement of the natives of New Holland; a difference that may be ascribed to the difference between the resins, and the greater or less force, with which their particles cohere. AV. 318 ON THE. PRECIPITATION OF SIL¥ER BY COPPER. XV. Nitevon the Pastigiaddion of Silver by es a by 3 Mr. Gay- _ Lussac*. Silver precipi- Mosr chemists are of opinion, that "the precipitate, tated from its obtained by leaving a slip of copper in a solution of nitrate solution by copperim- OF silver, is an alloy of the two metals, and that consequently pure: it is impossible to procure pure silver by this process. This | is the truth of the fact, when no attention is paid to parti- cular circumstanees: but if: we examine the different stages Sh darter of the precipitation, and attend to the causes that Mrodete obtained other- them, we:shall soon perceive, that itis easy to obtain silver wise. free from the copper by which it is precipitated. THe fits pat In fact, the first portions of silver separated are commonly tions separated pure, and do not give a blue tinge to ammonia, when they "eect are dissolved in nitric acid.. It is only, in proportion as the copper enters into solution, that we find any in the precipi-~ tate; so that toward the end of the process the quantity be- comes very evident. If therefore we separate the first por- and the whole tions of. silver, we sball find, them, exempt, from, _.copper: ak A's by but, to obtain considerable quantities,. we may, take. the adding’ nitrate whole of the precipitated silver, as I have done, wash it. never and digest it with a smalt quantity of nitrate of silver: by these means, the copper will be redissolved, and a corre= sponding quantity ef silver precipitated. . An affinity be- J am, far from thinking, that the mutual action Ay metals tween the me- js incapable of. occasioning the formation. of alloys i In me- tals may occa- sion an alloy to tallic precipitations : I only conclude, that, in the experi- fall down, but ment I haye just. related, the precipitation of the copper hot in this case is not occasioned by the affinity between this metul and sil- ver; since in this case we ought to have the same alloy i in every stage of the precipitation, and besides this. could not be hese ed by being placed in contact with a fresh quan- Galvanism acts tity of nitrate of silver. Precipitation in general being the in the precipi effect of a galvanic pfocess: it appears to me, that the one copper, which is reduced by hidrogen as well as silver, is precipitated with this metal by thesame cause. Many other metallic precipitations would exhibit similar results, * Annales de Chim. vol. LX XVIII, p. 91. ae XVI. MIXTURES ‘OF SULPHURIO ACID AND "WATERs’ 319-4 XVI. Table expressing the Quantities of Sulphuric Acid at 66° {specs grav. 1°842] contained in Mixtures of this Acid.and Water at different Degrees of the Areometer; by Mr. VAUQuELIN®. "Te use » ghee is made at present of sulphuric acid of Strength of different strengths for various uses, and particularly for the pes ait manufacture of soda, has rendered) it necessary for the ma- inquiry to ma- nufacturers and consumers of this acid, to inquire into the "tues quantity of concentrated acid, that is, at 66°, indicated ca the different degrees of the areometer. Ginttlectech ted: sulphurie acid not being necessary for the: Best strength decomposition of muriate of soda, that which is carried to.fordecompo- 50° in the chamber being even preferable, both the manu- sHoK situs facturer and consumer would find their advantage in the use of this, But to settle the price of this acid, according to the various degrees marked by the areometer, we must know how much acid of 66° there 1 is at each degree, which can be found only by experiment ; . the quantities of acid net being i in the direct ratio of the degrees, in. consequence of the condensation that takes place on the combination of the acid with water. : Having been very frequently consulted on this subject, I A table of have thought it would be useful, to construct a table by as means of experiments, in which the degrees of the areometer should show the weights of acid at 66°. For this purpose I began with taking accurately the spe- Method in cific gravity of the sulphuric acid at 66°, which I used in Meni isting making my mixtures ; and J found it to be 1°842, distilled constructed, water being taken as the unit, at the temperature of 12° of Reaum. [59° F.].. I then sought the quantities of this acid and water necessary to produce the degrees of the areometer used in trade to measure the density of this acid, Beene, at 60°, and proceeding downward by fives till I came to 5 The weights were ascertained with great care by means af a very sensible balance: the vessel, in which IT made my saixtures, was constructed so that the vapours formed by ® Annal. de Chim. val. LA XVI, p 260, the 320 © Table of mixtures of sulphuric ac'd and water. -~ MIXTURE OF SULPHURIC ACID AND WATER... the heat evolved in each instance could not escape; and I was careful not to take the decree on the areometer, till the mixture had returned to 12° KR. [59* F.]. Jreduced to hundredth parts the quantities of water re-_ quired to obtain the degrees on the areometer, which neces- sarily gave me fractions, It may be objected, that the intervals in my table are too great; and I confess it would have been better, to make as many mixtures ‘as the concentrated acid marks degrees on the areometer, namely 66: but, not to mention that this would have rendered my undertaking tedious and difficult, it would not have been of any great use for the purposes of - trade, for which it was. chiefly intended. In fact, the quan- tity of acid in any degree in these intervals may be obtained very nearly by means of a simple sum in the rule of a portion. : ‘Lastly, I have taken the specific gravity of each of my mixtures, which will give the means of ascertaining the quantity of acid and water in such mixtures, when au areo- meter is not at hand. ‘These ‘specific gravities too will show the degree of condensation, that water experiences, in combining sh sulphuric acid in the different proportions employed. Sulph. a Deg. of Specif. acid Areom. gravity. at €6°. Water. 8 1°023 6:60 93°40 © 10 1076" 11°73. 1 BaF 15 1-114 17°39 82°61 20 eS ante, 24°01 7D 5 26. B:210 30°12 69°88 | 30 1:260 3652 63°48 35 1°315 43°21 56°79" 40 | 1375 |. SirAal ‘49°59 45 1°466 58°02 | 41°98 50 1°524 66°45 33°55 55 1/618 74°32 25°63 © 60 1°725 | 84:22 15'73 66 1-642 en ee act algae dS ar " jes A JOURNAL OF NATURAL PHILOSOPHY, ‘CHEMISTRY, AND THE ARTS. SUPPLEMENT TO VOL. XXX, ARTICLE I. i On the Place of a Sound, produced by a musical String. In a Letter from Mr. Joun Goucu. To. Mr. NICHOLSON. SIR, | Cerrain experiments and remarks of mine on the Former obser- augmentation of sounds appeared in the tenth volume of apg referred your Journal; the intention of which communication was to show, that the range of a sound may be greatly extend. ed, by enlarging the vibrating surface, while the magnitude _ of the impulse remains the same. Among other remarks contained in that paper, a fact is mentioned; which proves, that the audible effect of a musical string varies with the texture of the instrument to which it is attached; or, to: use the language of certain writers on acoustics, the force of such a string depends not a little on the conducting _ power of the frame upon which it is stretched. Perhaps this assertion will be called a novelty in the Remarks on the theory of stringed instruments; for I believe, that the phi- Common theory losophers, who have turned their thoughts to the subject, pees are unanimous in maintaining, that the effect, which a vie brating fibre produces on the ear, proceeds solely from the pulses, excited in the air by the undulatory motion of the cord. In consequence of this doctrine, they make a mu- ‘sical string to be the seat of the sound which it occasions, SurrLement.—Vou. XXX, 4 in 322 Two experi- ments contra- dicting the re- ¢eived theory. A well known fact stated, t PLACE OF A SOUND FROM A MUSICAL STRING. in the same manner as a bell, a drum, anda tambarine may be called the seats of the sounds, which they impart to the ear through the medium of the atmosphere. Though I do not deny, that pulses are produced in the air by slender fibres\in the act of vibration, I have long disputed the accuracy of the prevailing theory, without being able to demonstrate the truth of the suspicion to my own satis- faction. An accidental observation, however, attracted my notice lately, which proves the string to be the exciting cause; and shows, that the sound proceeds from the frame or body of the instrument, in the same manner that the sound of a bell proceeds. from that vessel. The circum. stance here alluded to suggested the following easy experi- ments; which any one may repeat, who wishes to be con-~ vinced of the fact by his own experience. Exp. 1. Oneend of an iron wire (No. 28) was fastened to' a brass knob screwed into a table of deal, and the other end was wrapped round a slender cylinder of yew; four or five inches long. The wire measured six feet be- twixt the knob and cylinder, and I stretched it with con. siderable force, by holding the wooden pin in my hand, so as to let no part of the string touch my fingers. The wire being then made to vibrate, the sound, produced on the occasion, came from the table; not only in my opinion, but also in the judgment of several persons, before whom the experiment has been repeated at different times. : Exp, 2. If, in stretching the wire, one end of the yew cylinder was made to press upon a second table, placed five feet from that into which the brass knob was fixed, the surface became the seat of sound, that supported my hand ~ and the wooden pin. But when the cylinder was removed to asmall distance from the table, on which it pressed, and the wire was kept stretched at the same time, the sound was heard instantaneously as in the first experiment proceeding from the opposite table. It seems adviscable to remind the reader ofa well known fact, before the inferences are stated, which appear to be deducible from, the preceding experiments. When anumber of sounds strike the ear at ¢ the same time, one of which is much more powerful than any of the rests all the weaker escape notice, and the seat #f the strongest is alone recognised:.in more familiar lan- guage ) ! PLACE OF A SOUND FROM A MUSICAL STRING, 323 guage it is the only one of. the number, which the observer hears. Now three sets of vibrations are re evidently going on at the A vibrating same time, in the first experiment; these are the primary set oe ie of the wire, and the two derivative sets existing in the tabledrumstick at one end of it, and in the wooden pin at the other. Bu thon oe the length of the string enables the ear to ascertain which &c. one of the three sets gives the seat of the sound; and this is the vibratory motion of the table; consequently the table is the sounding body, and the wire does nothing more than perform the part of a drumstick in causing the surface of it to vibrate with great celerity. This discovery points out a distant analogy connecting the thundering noise of a drum and the smooth sounds of a harp orlute. They are, how. ever, very distinct to sense for obvious reasons: the cover of the former instrument is highly elastic, and the sound of it continues to die away for some seconds after it has been struck; each stroke of the drumstick renews this sound, and theinterval between two succeeding strokesis sufficient« ly large to be observed by the ear; and hence proceeds the thundering noise of adrum. On the contrary, the sound derived from the wooden frame of a stringed instrument by a single stroke is very transient; bat the impulses of the strings beat upon it with a celerity, which does not permit the sound to suffer a sensible diminution of force in the interval of two successive strokes; which is the cause of smoothness.in tones of this sort. In the second experiment, the vibrations, communicated The Bie: | from the wire to the cylinder of yew, are imparted by con. apse AS ve tact to the other table, which thereby becomes the seat of production ef sound; because, being nearer the person of the experimenter, °U"* it makes a more powerful impression on his ear, than the ‘first table; which stands at a greater distance from him. But so soon as the cylinder ceases to touch the board, that supports it, the experimenter hears the sound from the opposite table: notwithstanding it is farther from his ear than the wooden pin in his hand. Hence we discover the uti- ~ lity, and even the neeessity of extensive surfaces in the pro. ‘duction of sounds; for the impulses received from the wie ‘ drating wire, by the\table and cylinder, are equal in nume ter ‘and magnitude ; but of the three sets of contemporary OMbiAtions, that existing in the table is alone heard. ¥2 The 394: ; ACTION OF VEGETABLE POISONS: The frame of a The foregoing facts and observations demonstrate, that id ah nap the pulses excited in the aim by a vibrating cord do net of sound. make any sensible impression on the organs of hearing; - on the contrary, the sound, which we attribute to a musical string, comes in reality from the frame, upon which it is stretched. This errour of judgment arises from the proxi- mity of the cord and frame, which prevents the ear from determining whether of the two is the sonorous body ; we therefore ascribe the sound to the part that sustains the im- pulse. Itis true, indeed, that the notes of a harpsichord or violin are caused by the vibrations of the strings; but then the various modifications, incident to these rapid and delicate motions, are imparted to the ear through the medium of the less elastic frame ; the momentary sounds of which change their character when acted upon by a quick succession of impulses, and become continuous. Middleshaw, Dec. 6, 1811. JOHN GOUGH. eee anay II. Experiments and Observations on ‘the different Modes in ‘which Death is produced by certain vegetable Poisons ; By B.C. Bropiz, Esq. F.R.S. Communicated by the Society for promoting the Knowledge of Animal Che- -— mistry. (Concluded from p. 307.) Poisons ap- LAL. Experiments with Poisons applied to wounded Surfaces. plied to Experiments with the essential Oil of ‘Almonds. wounds, - Essential oil of Exp. 16. I MADE an incision in the thigh of a rabbit, and * almonds. introduced two drops of essential oil between the skin and Experiment 16. |, ‘ eae tga the muscles. In four minutes after the application, he was seized with violent convulsions, and became insensible, and in two minutes more he was apparently dead ; but the heart was felt through the ribs acting one hundred and twenty times in a minute, and it continued acting for several mi- nutes. ‘There were no other appearances in the limb, than ‘would have resulted from an ordinary wound. Experiment17. zp. 17. Two drops of the essential oil of almonds were — introduced into a wound in the side of a mouse. Two mi- ° nutes afterward he was affected with symptoms similar to those ACTION OF VEGETABLE POISONS. ', "325 those which occurred in the last experiment, and in two minutes more he was apparently dead; but the heart con. tinued to contract for some minutes afterward. “From the experiments which I have just related, and Acts as when from others which it appears unnecessary to detail, as the me asda general results were the same, I have learned, that, where quickly. the essential oil of almonds is applied to a wound, its effects are not so instantaneous as when it is applied to the tongue; otherwise there is no difference in its effects, in whatever manner it is applied. ¥ Experiment with the Juice of the Leaves of Aconite. Exp. 18. I made a wound in the side of a young rabbit, J uice of aconite and introduced between the skin and muscles about twenty Experiment 18, drops of the juice of aconite. Twenty-three minutes afterward he was affected with symptoms in all essential respects similar to those, which occurred in an experiment already related, where the juice was injected into the rectum; and at the end of forty-seven minutes from the application of the poison, he was apparently dead. Two minutes after apparent death, the heart was found contract. ing, but very feebly. \ Experiments with the Woorara*. _ Exp. 19. A small quantity of the woorara in powder Woorara. was applied to a wound in the side of a guinea pig. Ten Experiment 19, minutes afterward the animal was unable to walk; then he became quite motionless, except some slight occasional con. vulsions. He gradually became insensible, the respirations were laboured, and at the end of fourteen minutes from the application of the poison, the respiration had entirely ceased, and he was apparently dead; but on opening the thorax, the heart was. found acting seventy times in a mi- - * The woorara is a poison, with which the Indians of Guiana arm the points of their arrows; It appears not to differ essentially _ from the ticunas, which was employed in the experiments of the. Abbé Fontana.- I am indebted to Dr. E. N. Bancroft, who not ‘only furnished me with some of the woorara, which he had in his possession, but also Jent me his assistance in the experiments, which were made with it, nutes 326 Experiment 20. Tt acts on the brain. Best applied dissolved in water. Probably weak from age. ACTION OF VEGETABLE POISONS. nute, circulating dark coloured blood, and it continued to contract for several minutes afterward. On dissection ne. preternatural appearances were observed in the brain; nor was there any other appearance in the limb, than would have arisen from an ordinary wound, Exp. 20. I made a wound in the side of a guinea pig, and introduced into it about two grains of the woorara in powder., At the end of twenty-five minutes, symptoms took place very similar to those, which occurred in the last experiment, and in thirteen minutes more the animal was apparently dead; but the heart continued to contract one hundred and eight times in a minute, and by means of artficial respiration the circulation was kept up for more than twenty minutes. The results of other experiments, which I have made with the woorara, were similar to those just described, The heart continued to act after apparent death, and the circulation might be kept up by means of artificial respira. tion. It is evident, that this poison acts in some way or other on the brain, and that the cessation. of the func. tions of this organ is the immediate cause of death. — I found in these experiments, that the best mode of ap. plying the woorara is when it is dissolved in water to the ‘consistence of a thin paste. I first made the wound, and then smeared the poison over it with the end of the scalpel. I found that the animal was more speedily and certainly affected, if there was some hemorrhage ; unless the hemorrhage was very copious, when it produced an op- posite effect, by washing the poison away from the wound, When the poison was applied in large quantity, it some. times began to act in six or seven minutes. Never more — than half an hour elapsed from the time of the poison being inserted, to that of the animal being affected, except in one instance, where a ligature was applied on the limb, which will be mentioned afterward. The woorara, which I employed, had been preserved for some years, which will account for its having been less active, than it has been described to be by those, who had witnessed its effects when in a recent state. Experiments ACTION ON VEGETABLE POISONS, 397 Experiments with the Upas Antiar *. Exp. 21. About two grains of this poison were made Upasantiar. into a thin paste with water, and inserted into a wound in Experiment 24, the thigh of a dog. Twelve minutes afterward he became languid; at the end of fifteen minutes, the heart was found to beat very irregularly, and with frequent intermissions ; after this, he had a slight rigour. At the end of twenty minutes, the heart beat very feebly and irregularly; he ‘was languid; was sick and vomited ; but the respirations were as frequent and as full as under natural circumstances, and he was perfectly sensible. At the end of twenty mi- nutes, he suddenly fell on one side, and was apparently ’ dead. I immediately opened into the thorax, and found the heart distended with blood in a very remarkable de- gree, and to have entirely ceased contracting. There was one distinct and full inspiration, after I had begun making the incision into the thorax. ‘The cavities of the left side of the heart contained scarlet blood, and those of the right side contained dark coloured blood, as in a living animal. fess Exp. 22. A small quantity of the upas antiar, prepared Experiment 22. ‘as before, was inserted into a wound in the thigh of a young cat. She appeared languid in two minutes after the poison was inserted. The symptoms, which took place, did not essentially differ from those, which occurred in the last experiments, except that there were some convulsive motions of the limbs. At eight minutes after the poison was inserted, she lay on one side, motionless and insensible the heart could not be felt, but the respiration had not en- tirely ceased. On opening into the thorax, I found the heart to have ceased contracting. It was much distended With blood: and the blood in the cavities of the left side was of a scarlet colour. There were two full inspirations after the incision of the thorax was begun. On irritating ~ * We are informed, that the island of Java produces two power- ful vegetable poisons, to one of which the natives give the name of upas tieuté, and to the other that of upas antiar. T was sup- plied with a quantity of the latter through the kindness of Mr. Marsden, who had some of it in his possession. . the 328 Experiment 23. ¥xperiment 24 Tt appears to act like the in- fusion of to- bacco, on the heart. How do poisons applied to wounds act on the brain? ACTION OF VEGETABLE POISONS. the heart with the point of the scalpel, slight contractions took place in the fibres of the Bppannices of the auricles, but none in any other part. Exp. 23. The experiment was repeated on a rabbit. The symptoms produced were similar to those in the last experi- meuts; but the animal did not vomit, and the convulsive. motions were in a less degree: he died eleven minutes after the poison was inserted. On opening the chest, the heart | was found to have entirely ceased contracting ; it was much distended with blood; and the blood in the cavities of the Jeft side was of ascarlet colour. On irritating the heart with the point of the scalpel, the ventricles contracted, but not sufficiently to restore the circulation. Exp. 24. About a grain of the upas antiar was inserted into a wound in the side of arabbit. He was affected with symptoms similar to those before described, and died in ten minutes after the poison was applied. On opening the thorax immediately after death, the heart was found to have ceased contracting, and the blood in the cavities of the left side was of a scarlet colour. It appears from these experiments, that the upas antiar, when inserted into 2 wound, produces death (as infusion of tobacco does when injected into the intestine) by rendering the heart insensible to the stimulus of the blood, and stop- ping the circulation. The heart beats feebly andirregularly, before either the functions of the mind, or the respiration appear to be affected. Respiration is performed even after the circulation has ceased; and the left side of the heart is found after death to contain scarlet blood, which never can be the case, where the cause of death is the cessation of the functions of the brain or lungs. The convulsions, which occur when the circulation has nearly ceased, pro- bably arise from the diminution of the supply of blood to the brain, resembling those, which take place in a person, who is dying from hemorrhage. There remains an interesting subject of inquiry, *‘ through what medium do poisons influence the brain, when applied to wounds?” ‘That poisons applied in this manner do not produce their effects precisely in the same way as poisons taken internally, is rendered probable by this circumstance ; that ACTION OF VEGETABLE POISONS. 329 that some poisons, which are very powerful when ap. plied to wounds even in small quantities, are either al. together inefficient when taken internally, or require to be given in very large quantities, in order’to produce their ef. . -fect ; and vice versd. A poison applied to a wounded surface may be supposed Three possible to act on the brain in one of three ways, beh 1. By means of the nerves, like poisons taken internally. 2. By passing into the circulation through the absorbent vessels. 3. By passing directly into the circulation through the divided veins. Exp. 25. In order to ascertain, whether the woorara acts Experiment 25, through the medium of the nerves, I exposed the axilla Aah sa a rabbit, and divided the spinal nerves supplying the upper extremity, just before they unite to form the axillary plexus. ‘The operation was performed with the greatest care. ITnot only divided every nervous filament, however small, which I could detect, but every portion of cellular membrane in the axilla, so that the artery and vein were left entirely insulated. I then made two wounds in the fore arm, and inserted into them some of the woorara form. ed into a paste. Fourteen minutes after the poison was the effects the applied, the hind legs became paralytic, and in ten miautes*°™* more he died, with symptoms precisely similar to those, which took place in the former experiments, arid the heart continued to act after apparent death. On dissection, the nerves of the upper extremity were particularly examined, but not the smallest filament could be found undivided. I made the following experiment to ascertain whether the woorara passes into the circulation through the absorbent vessels. Exp. 20. I tied a ligature round the thoracic duct of ooacaeaee. dog, just before it perforates the angle of the left sub. had cau clavian and jugular veins. I then made two wounds in the left hind leg, and introduced some of the woorara in powder into them. In less than a quarter of an‘hour hethe effects the became affected with the usual symptoms, and died in a few “™% _ minutes afterward. After 330 ACTION OF VEGETABLE POISONS. After death, I dissected the thoracic duct with great care. I-found it to have been perfectly secured by the li. gature. It was very much distended with chyle, and about two inches below its termination its coats had given way, and chyle was extravasated into the cellular membiane. ‘The lymphatic vessels in the left axilla were distended in a very remarkable degree, and on dividing them, not less than a drachm of lymph issued from the divided ends. ‘The poison Since neither the division of the nerves, nor the obstruc. He reas tion of the thoracic duct interfere in the slightest degreé through the With the effects of the woorara, there is presumptive evi- veans. _ dence, that it acts on the brain by entering the circulation through the divided veins. I endeavoured to ascertain, by experiment, whether this is really the case. To apply ligatures to the large vessels of a limb only would evidently lead to no satisfactory conclusion, since the anastomosing vessels might still carry on the circulation. The only way, which I could devise, of performing the experiment, was to include all the vessels, small as well as large, in a ligature. Experiment27, Exp. 27. In order to make the experiment the more sae ‘Fhe blood ves- tisfactorily, I exposed the sciatic nerve of a rabbit in the sels mcluded in s i = a ligature, upper and posterior part of the thigh, and passed under it a tape half an inch wide. IT then made a wound in the leg, and having introduced into it some of the woorara mixed with water, I tied the tape moderately tight on the fore part of the thigh. Thus I interrupted the communi. cation between the wound and the other parts of the body by means of the vessels, while that by means of the nerve still remained. After the ligature was tightened, I applied the woorara a second time, in another the animal not part of the leg. The rabbit was notvat all affected, and at . be olin the the end of an hour I removed the ligature. ‘Being engaged removed. in some other pursuit, I did not watch the animal so closely as I should otherwise have done; but twenty minutes after the ligature was removed, I found him lying on one side, motionless and insensible, evidently under the influence of the poison ; but the symptoms were less violent than in most instances, and after lying in this state he recovered, and the limb became perfectly warm, and he regained the power of usingit. Euperimenté ACTION OF VEGETABLE POISONS. 331 Exp. 28. I repeated the last experiment with this differ. Experiment 28. ence, that after having applied the poison, I made the liga. ture as tight as I could draw it. I removed the ligature at the end cf an hour and twenty minutes, but the animal was not at all affected either before or after the removal of the ligature, and on the following day he had recovered the use of the limb. Exp. 29. I repeated the experiment a third time, drawing Experiment 29, the ligature very tight. At the end of forty-five minutes, the animal continued perfectly well, and the ligature was removed. I watched him for three quarters of an hour afterward, but there were no symptoms of his being affected by the poison, On the following day the rabbit died, but this I attribute to the injury done to the limb and sciatic nérve by the ligature, as there was the appearance of in- flammation in the parts in the neighbourhood of the ligature. These three experiments were made with the greatest care. All confirm the From the mode, in which the poison was applied, from the rip ry quantity employed, and from my prior experience, I should enters theveins, have entertained not the smallest doubt of the poison taking : effect in every instance in less than twenty minutes, if no ; ligature had been applied. In two of the three, the quans : tity of woorara was more than had been used in any former experiments. - [have not judged it necessary to make any more experi. Abbé Fontana’s ments, with the ligature on the limb; because the numerous andes experiments of the Abbé Fontana on the ticunas coincide same conclu- in their results with those, which have just been detailed, S™ and fully establish the efficacy of the ligature, in pre. venting the action of the poison. It is not to be wondered at, that the ligature should sometimes fail in its effects ; since these must evidently depend on the degree, in which — the circulation is obstructed, and on the length of time during which the obstruction is continued. There can be little doubt, that the woorara affects the brain, by passing into the circulation through the divided ‘ vessels. It is probable, that it does not produce its effects, until it enters the substance of the brain, along with the blood, in which it is dissolved; nor will the experiments of even where — the Abbé Fontana, in which he found the ticunas none psi d we almos \ 332. ACTION OF VEGETABLE POISONS. almost' instant death, when injected into the jugular vein of - a rabbit, be found to militate against this conclusion; when we consider how short is the distance, which, in so small an animal, the blood has to pass from the jugular vein to the carotid artery, and the great rapidity of the circulation; since in a rabbit under the influence of terrour, during such an experiment, the heart cannot be supposed to act so seldom as three times in a second. I have made no experiments to ascertain through what medium other poisons, when applied to wounds, affect the - ‘vital organs, but from analogy we may suppose, that they enter the circulation through the divided blood-vessels. IV. Death from de- ‘The facts already related led me to conclude, that alcohol, ee the the essential oil of almonds, the juice of aconite, the oil of brain. tobacco, and the woorara, occasion death simply by de- stroying the functions of the brain. The following ex- periment appears fully to establish the truth of this con- clusion. ‘Experiment 30: Hap. 30. ‘The temperature of the room being 58° of i Fahrenheit’s thermometer, I made two wounds in the side of a rabbit, and applied to them some of the woorara in / the form of paste. In seven minutes after the application, the hind legs were paralysed, and in fifteen minutes respi- ration had ceased, and he was apparently dead. Two mi. nutes afterward the heart was still beating, and a tube was introduced through an opening into the trachea, by means of which the lungs were inflated. The artificial respiration was made regularly about thirty-six times’in a minute. At first, the heart contracted one hundred times in a mi- nute. At the end of forty minutes, the pulse had risen to one hundred and twenty in a minute. , At the end of an hour, it had risen to one hundred and ; forty in a minute. At the end of an hour and IF iaitives minutes, the pulse had fallen to.a hundred, and the artificial respiration was discontinued. At the commencement of the experiment, the ball of a thermometer hems placed in the rectum, the quicksilver TOSS ACTION OF VEGETABLE POISONS, 333 rose to one hundred degrees; at the close of the experiment it had fallen to cighty-eight and a half. During the continuance of the artificial respiration, the blood in the femoral artery was of a florid red, and that in the femora] vein of a dark colour, as usual. It has been observed by Mr. Bichat, that the immediate Immediate cause of death, when it takes place suddenly, must be the ruse Ohana cessation of the functions of the heart, the brain, or the lungs. This observation may be extended to death under all circumstances. The stomach, the liver, the kidneys, and many other organs, are necessary to life, but their constant action is not necessary; and the cessation of their functions cannot therefore be the immediate cause of death. Asin this ~ case the action of the heart had never ceased; as the circula- tion of the blood was kept up by artificial respiration formore than an hour and twenty minutes after the poison had pro. duced its full effects; and as during this time the usual changes in the colour of the blood took place in the lungs; it is evident, that the functions of the heart and lungs were unimpaired: but that those of the brain had ceased, is '. proved, by the animal having continued in a state of com- plete insensibility; and by this circumstance, that animal heat, to the generation of which I have: formerly shown the influence of the brain to be necessary, was not genes rated. Having learned, that the circulation might be kept up by Perhaps life artificial respiration for a considerable time after the er eh ath \woorara had produced its full effects, it occurred to me, ing up artificial, that, in an animal under the influence of this or of any “°P™*40™ other poison, that acts in a similar manner, by continuing the artificial respiration for a sufficient length of time after natural respiration had ceased, the brain might recover from the impression, which the poison had produced, and the animal might be restored to life. In the last experiment, the animal gave no sign of returning sensibility: but it is to be observed, 1. That the quantity of the poison em~ ployed was very large. 2- That there was a great loss of animal heat, in consequence of the temperature of the room being much below the natural temperature of the ; animal, 334 ACTION OF VEGETABLE POISONS. animal, which could not therefore be considered under such favourable circumstances as to recovery, as if it had been kept in a higher temperature. 3. That the circulation was still vigorous when I left off inflating the lungs; and theres fore it cannot be known what would have been the result, if the artificial respiration had been longer continued. Experiment30. Hap. 30. A wound was made in the side of a rabbit, and aa one drop of the essential oil of almonds was inserted into it, and immediately the animal was placed in a temperature of 90°. In-two minutes he was under the influence of the poison. The usual symptoms took place, and in three mis nutes more respiration had ceased, and he lay apparently dead, but the heart was still felt beating through the ribs. A tube was then introduced into one of the nostrils, and the lungs were inflated about thirty-five times in a minute, Six minutes after the commencement of artificial respiration, he moved his head and legs, _and made an effort to breathe, He then was seized with convulsions, and again lay motions less, but continued to make occasional efforts to breathe. Sixteen minutes after its commencement, the artificial rea spiration was discontinued. He now breathed sponta neously seventy times in a minute, and moved his head and © extremities. After this, he occasionally rose, and attempt. ed to walk. In the intervals, he continued in a dozing state; but from this he gradually recovered. In less than two hours he appeared perfectly well, and he continued well on the following day. Inflating the The inflating the lungs has been frequently recommended peceuremy Fd in cases of suffocation, where the cause of death is the ces« ferent instances. sation of the functions of the lungs: as far as [ know, it has not been before proposed in those cases, in which the cause of death is the cessation of the functions ‘of the brain*. It is probable, that this method of treatment might Experiments of .* Since this paper was read, I have been favoured by the Right Mz, Delite. © Hon. the President with the perusal of a Dissertation on the Effects of the Upas Tieute, lately published at Paris by Mr. Delile; by which J find, that he had employed artificial respiration for the recovering animals, which were under the influence of this poison, with success. Mr. Delile describes the upas tieuté as causing death ata by. * ACTION OF VEGETABLE POISONS, 335 _ might be employed with advantage for the recovery of pers sons labouring under the effects of opium, and many other poisons. ¥. The experiments, which have been detailed, lead to the General con- following conclusions. clusions, 1. Alcohol, the essential oil ‘of almonds, the juice of aconite, the empyreumatic oil of tobacco, and the woorara, act as poisons by simply destroying the functions of the brain; universal death taking place, because respiration is . under the influence of the brain, and ceases when its func tions are destroyed. 2. The infusion of tobacco, when injected into the ins testinc, and the upas antiar, when applied to a wound, have the power of rendering the heart insensible to the sti- mulus of the blood, thus stopping the circulation; in othér words, they occasion syncope. 3. There is ‘reason to believe, that the poisons, which in these experiments were applied internally, produce their ef. fects through the medium of the nerves, without being abe ‘sorbed into the circulation, | 4. When the woorara is applied to a wound, it produces its effects on the brain, by entering the circulation through the divided ‘blood-vessels; and, from analogy, we may con. clude, that other poisons, when applied to wounds, operate in a similar manner. 5. When an animal is apparently dead from the influence - of’a poison, which acts by simply destroying the functions of the brain, it may, in some instances, at least, be made to recover, if respiration is artificially produced, and con- tinued for a certain length of time. | ts ‘From analogy we might draw some conclusions respect. ing the mode, in which some other vegetable poisons pros duce ‘their effects on the animal system; but I forbear to enter into any speculative inquiries; as it is my wish, in the present communication, to record such facts only, as appear to be established by actual experiment. by occasioning repeated and long continued contractions of the ~ mnuscles of respiration, on which it acts through the medium ofthe spinal marrow, without destroying the functions of the brain. ILI. Description gene 336 Machine for cleaning roots. Disadvantages of an old one for the purpose. "Fhese removed. medal was voted to Mr. Lester. MACHINE FOR WASHING ROOTS. IIT. Description of a Machine for Washing Potatoes and other esculent Roots for feeding Cattle: by Mr. Wit1am Lxster, of Puddington*. SIR, . Herewrr H you will receive a machine for the more expeditious washing of all tuberous rooted vegetables (such as potatoes, turnips, carrots, &c.) from the soil that ad« heres to them -when taken from the ground. The staved cylinder, revolving in a trough of water so slow as not to excite the centrifugal force, isnot new. I have made use of it myself twelve years ago, but always found it cold and wet work, to take the roots from it when washed. To obviate which, I have added the levers and wheels, and find it a very great improvement, as a boy therewith can do the work of two men, without exposing himself to the dangerous effects of dabbling in cold water. The importance of thig mode will appear very obvious, when compared with the present laborious one used by the potato sellers in London. The partial motion given to the potatoes, by stirring them about in a tub, cannot separate the soil so effectually from them, as when the water is more violently agitated by their falling over each other in a re- volving cylinder, neither will they be so much bruised as by the ends of the levers. If the soil should be particularly adhesive, the heads of a couple of old heath or birch brooms put into the cylinder will effectually. disengage it from the eyes of the potatoes, and as the dirt separates, it falls to the bottom of the water in the vessel under the ‘cy- Jinder. ) If you will have the goodness to lay this before the So. ciety, and it should be deemed worthy of their attention, I will, if necessary, on being requested, attend to explain the effects of the machine. I am, Sir, ¢ Your most humble and obedient servant, W. LESTER. * Trans. of the Society of Arts, vol, xxvii, p.34. The silver SIR, “ MACHINE FOR WASHING ROOTS. 337 SIR, $ AGREEABLE to your request I have procured the Great saving of ericlosed certificates, &c., on the utility of my improved root sapien washer, which you will have the goodness to lay before the with it. Society. | I have no doubt but it would save half the labour in washing potatoes in London, if it were brought into use: It is obvious to every one who has seen it work, that it is greatly superior to the tub and levers used by the potatos merchants, as it is not so liable to injure the roots. The soil is drawn from them with more facility, and their fall. ing intu the basket from the cylinder is more clean and commodious by far than taking them out of the tub witha - grated shovel, from the corners of which many roots are bruised ; it also prevents the potatoes being injured in quae lity from being long soaked in water, from which they suffer greatly in the common way. I an, Sir, Your most obedient and humble servant, W. LESTER. Certificates of the Utility of Mr. Lusrer’s Machine for washing Tuberous Roots. SIR, IN reply to your inquiries respecting the utility of the Testimonies of root-washer, which I purchased of you about twelve assis months since, { have mueh satisfaction in stating, that I have used it, constantly, during the last winter, and have found it to answer the ‘purpose for which it is intended most tho. roughly; and if my opinion will be of any benefit to you, I have not the least objection to your making it public. I am, Sir, | ' Your obedient humble servant, JAMES JOHN FARQUHARSON. SIR, IN answer to yours I have to observe, I consider your root-washer to be a machine that no farmer, who is in the habit of giving roots to his stock, ought to be without. I use it constantly in washing potatoes for 150 fattening sheep, beside hogs. A man, and a boy ten years old, will wash, Surrrement.—VoL, XXX. Z ' without 938) Description of the machine. Mode of using it, - ® MACHINE FOR WASHING ROOTS, without any exertion 20 bushels an hour, or a man alone will do-nalf the quantity. I have tried a few parsnips with it, and find it do them equally as well, and have no doubt but any kind of roots may be washed with it. Iam very much pleased with it, and so must every one who has tried it. With every wish foryour success, Iam, yours sincerely, JOHN CLARKE. To Mr. Luster, '&c. LORD NORTHAMPTON acquaints Mr. Lester, that the potato-washer, that was bought of him, answers the purpose perfectly well, and is approved by all who have used it. Decription of Mr. Lasver’s Machine for washing Potatoes, So Plate 1X, Fig. THIS machine is shown in plate IX, fig. 1. The pota- toes are put into a cylinder or lantern A A, formed of two circular boards, and a number of staves connecting them. Six of these staves are connected at the ends of two pieces of wood, so that they can be opened as a door, to put in or take out the potatoes. The cylinder turns round in a trough BB, filled with water, and supported on four legs. On the end of the axis of the cylinder, two pulleys, one of which is shown separately at D, are loosely fitted ; these are intended for the cylinder to move upon, when full of po- tatoes; they run upon a swinging frame KE, which rests on centres at FF; when the long end of the frame is pulled down, tbe other end is raised up, lifting the cylinder out of the trough BB; when the long end of the frame be-. comes the lowest, the cylinder rolls down on its wheels D, till it is over the hopper or wooden funnel G, under which a wheelbarrow or basket to receive the clean potatoes is placed: the door of the cylinder is now opened, and the contents turned out through the hopper into the vessel be- neath it. When the frame is in this situation, the iron rods H, which are jointed to the short ends of the levers, form stops to the farther descent of the frame. ; - When fresh quantities of potatoes are to be washed, they are thrown in at the door of the cylinder, which is then — shut . | METHOD OF PACKING PLANTS FOR EXPORTATION, 339 shut up, and held shut by two small bolts. The end of the frame E is then raised up, so as to make the short end the lowest, and the cylinder runs down on its two wheels D over the trongh 3B, till it is stopped by two iron prongs fixed on the end of the frame EK; the cylinder is then suffered to fall down into the trough, and the potatoes, &c. are washed by turning it round by its handle K. a@ is a plug to let out “a the foul water. Any person who has seen the laborious and imperfect Advantages. method of washing potatoes in a tub, as practised in Lon. don, will be convinced of the utility of this machine, and of its preserving the potatoes from being water soaked and spoiled, which is the case when they are long immersed in water. IV. Method of packing Plants and Trees intended for Expor« tation, so as to preserve their vegetative Powers for many Months: by Witx1am Sauissury, of the Botanic Gardens at Brompton and Sloane-Street *. SIR, % Y HEN I had the pleasure of secing you last Spring, I Discovery ofa “mentioned a supposed discevery I had made of a substance, ait ee that would preserve trees and plants for a considerable time pial ina in a growing state, when packed up in close boxes: bar et that by this method they might be sent abroad to great distances with more success and less trouble than in any other. I now take the liberty of troubling you with the results of several experiments, which I have since made; _ being certain, that a greater demand will be found for the various articles cultivated in this country, and the persons who are engaged in that trade benefitted, when it is publicly Known. A box I have now sent, marked No. 1, contains speci- Trees packed in mens of tulip trees, and liquid amber trees, which were'* s* months, * Trans, of the Soc. of Arts, Vol. XXVIL p. 40. Twenty guineas were yoted to Mr, Salisbury for this communication. ‘ Z2 packed. 340 Several trees sent toAmerica. ‘Trees packed four months or more. Fh Cause of trees being injured in long jour- neys. Planting in boxes of earth too trouble- some. Properties of the sphagnum palustre, or common bog | maoss, METHOD OF PACKING PLANTS FOR EXPORTATION: packed up close from September, 1807, till March, 1808: they were then planted in my nursery; and the whole, amounting to-several hundreds, have grown equally as well as they would have done, if only transplanted from one part to another of the same ground. In February last I sent to Boston in New England two packages in this way, each containing upwards of nine hun. dred trees of different kinds ; and I have lately received the pleasing intelligence, that they have all arrived safe and done well, but that some fruit trees sent to the same gentle. man, packed in the usual way, were all spoiled, owing to the heat of the hold of the vessel, in which all the packages were placed. " The other box I now send to you, marked No. 2, con- tains specimens of different trees, which were packed up by my order, some of which have been in the boxes four months, and others a longer period, and the remainder now in the boxes are all in a similar state of preservation, and I have little doubt will remain three months longer, or more, without injury. I must beg leave to observe, that the principal cause why things of this nature do not succeed in long journeys is, that if the package, (as is commonly the case) becomes by any means damp, it is very liable to heat, and the contents to be thereby very much injured: and if Icft dry, the moisture of the trees becomes exhausted, and they consequently die for want of nourishment. The mode recommended some years ago by’ Mr. Ellis, of planting the articles in tubs or boxes of earth, is attended with so much trouble, that it has been scldom found to succeed. In packing my plants, I make use of the long white moss, the sphagnum palustre of Linneus, which grows in great plenty on peat bogs, and, when decayed, forms a great portion of that substance. It differs materially from other . vegetables in possessing the power of retaining moisture in a wonderfal degree, and it does not appear to be liable to fermentation in any situation, even when laid together in great quantities; hence a decomposition does not readily take place, and it preserves the power of affording moisture ; and METHOD OF PACKING PLANTS FOR EXPORTATION. and nutriment to plants when completely enveloped in it, as appears by the above experiment. Iam, with great respect, Sir, Your very obedient, and most humble servant, WILLIAM SALISBURY. WE hereby certify that we packed up the several trees and plants at the times marked in the labels of those in the box No. 2, by desire of Mr. Salisbury, and that the said specimens have remained ever since in the boxes as above described. ALEXANDER REITH. JOHN WOODHOOD. DEAR SIR, 341 THE prosperity of a country was never more rapidly Benefits of the study of natural promoted, than we have happily witnessed in our own nation within a few years, since the study of natural history has become so general among all ranks of society; and pro. history. . bably nothing has contributed so much thereto as the ex.. tended knowledge of botany, and the numerous collections — of vegetable productions, which have lately been intro- duced from all parts of the world. From such sources our agriculture,!and many of the arts, have been greatly im- proved; yet much still remains to be accomplished by the Much still wanting assiduous botanist ; for instance, neither the plants produc. ing the cinchona, or which nourish the cochineal, have yet reached our soil, nor are we even acquainted with those which yield many of our most useful drugs. This is owing, from the diffi- culty of Reeping eeds in a great measure, to the difficulty of procuring perfect , seeds, it being a well known fact, that many kinds will not vegetate, if left dry but a short time after gathering; and the difficulty of keeping plants alive during long voyages has andplants alive. been almost an insuperable abstacle, Impressed, therefore, with the importance of the subject, I wrote to you on the 9th of January last, and have now the pleasure of commu. nicating to the Society of Arts, &c., for the benefit of the public, farther particulars of the mode I have discovered ; and by which I am convinced, from actual experiments, trees or plants of all kinds may, with ease and certainty, be transported from any part of the globe to this country and our colonies; being confident, that our commerce will be improved 342 The sphagnum palustre pre- serves plants in a vegetating state. tt. Other mosses do not answer the same . purpose. METHOD OF PACKING PLANTS FOR EXPORTATION. improved by a more certain mode of exporting the nume-s rous fruits with which our nurseries exclusively abound. I had, some time ago, an opportunity of viewing a large heap of moss (sphagnum palustre, Linn.) which had been collected for decorating a grotto. I observed, that, al- though it had lain exposed for several months in the heat of summer, yet, with the exception of the very outside of the heap, its particles appeared in the same state as when first collected, and that a gentle state of vegetation was still go- ing on. I moreover observed, that several species of heaths, grasses, and plants, that had been by chance collected in the heap, were preserved, and in several instances had the same appearances as when growing; others were a little blanched for want of light; but even these were alive, and Experiments on capable of growing by proper management. These circum stances led me to make some experiments to ascertain how long trees of different kinds might be preserved i in this sub- stance, when excluded from the external air; and I so far succeeded, as to keep them for six months, det of which time had been extreme hot weather, and I had afterward the pleasure of getting them to grow in my garden equal to any, that had been transplanted the same season. As I have endeavoured to discover what property this particular moss possesses, when compared with others gene~ rally used for packing plants, I shall remark, that, as its _ name implies, it is in a great measure an aquatic, and cou-~ sequently not liable to injury from moisture, which it has the power of retaining in a wonderful degree, while all the species of hy; pnum cannot be prevented from rotting, un- less they are kept perfectly dry ; ; and although the mosses in geaeral, when moistened with water, are useful to wrap round the roots of trees when packed up, yet they gradually undergo adecomposition; and consequently, if plants were completely enveloped therein, they would decay in time from the same cause, which I have proved in many in- stances. I was therefore Jed to ascribe the advantages, which the sphagnum palustre possesses, to its property of holding wa. ter, and resisting fermentation ; and I am confirmed in this opinion, by a letter, which I have received from my worthy friend METHOD OF PACKING PLANTS FOR EXPORTATION. 343 friend Mr. A. T. Thompson, to whom [I had submitted some of that moss, for a chemical analysis, and whose let. ter I now enclose. The manner in which I have been accustomed to pack Mode of pack- up plants is as follows. When the moss is collected from "5 Piauts iat, the bogs in which it grows, it should be pressed, in order to drain out as much moistureas possible, and having boxes prepared of sufficient sizes for the young trees, (which may in some instances be shortened in their branches), I lay in the bottom of the box as much moss as will, when pressed with the foot, remain of the thickness of four inches. A Jayer of the plants should then be put thereon, observing that the shoots of each other do not touch, and that the space of four inches be left round the sides; after this, another layer of moss, about twoinches thick, is placed, and then more plants; and I thus proceed, till after the whole of the plants are pressed down as tight as possible, and the box filled within four inches of the top, which space must be filled with the moss: the contents are then trodden down with the foot, and the box nailed closely up. When trees are intended to be sent to distant countries, Treatment of I should-advise such to be selected as are small and healthy ; the trees when and when arrived at their place of destination, they dial. aa be cut down quite close, even to the second or third eye from the graft, or, in trees not grafted, as near the former year’s wood as possible ; and having prepared beds according _ to the following mode, let them be planted therein, to serve asa nursery; for trees of every description suffer so much from removal, that, unless the weather is particularly favour. able, they do not recover it for some time, even when only transplanted in their. native climate. I do not think it ad. visable, therefore, to plant them at once, where they are liable to suffer from want of water, and other attentions ne- cessary to their perfect growth. I therefore recommend beds to be thus prepared for them, viz. On some level spot of ground, mark out, beds five fect wide, and leave walks or alleys between them, of two feet wide, throwing a por- tion of the earth out of the beds upon the alleys, so as to leave them four inches higher than the beds. Tf SALA METHOD OF PACKING PLANTS FOR EXPORTATION. If the ground is shallow, and the under stratum not fit for the growth of trees, the whole should be remoyed, and ~ the beds made good with a better soil. ci of The advantage arising from planting trees in this way is, that, the beds being lower than the walks, the water which is poured on, for support of the trees, is prevented from running off. ‘The plants are also less exposed to the influ- ence of the winds; and, if a dry and hot season should ime mediately foliow after they are planted, hoops covered with mats, straw, or canvas, may be placed over them, to pres vent the sun from burning the plants, and to hinder a tog speedy evaporation of moisture, ‘Shades for ¢ the In warm climates, canvas cloth will answer best for these ips shades, to be fixed during the heat of the day, so as to pre- yent the surface of the mould from becoming dry ; and if 4 little water be sprinkled upon the canvas, once or twice dur. ing the day, it will keep it tight, and produce a moist at. mosphere underneath, which will greatly facilitate the growth of the plants. _ These shades should be removed at the setting of the sun, and the plants then watered, when they wili also receive the benefit of the dews during the night. In the morning _ the shades should be replaced, and the plants thus protected till they can stand the open air, to which they should gra. ' dually be inured by removing the shades daily more and more, till they can be wholly taken away. Distance pret The plants should be planted in rows across the beds, seriig | about three inches distance from each other, and the rows should be about nine inches apart ; and when the plants have grown thus for one year, they may be removed to the places where they are intended to remain. I remain, dear Sir, your obedient servant, : 9 WM. SALISBURY. DEAR SIR, Analysisofthe . THE analysis of the moss, which you put into my a ep Po hands, has afforded the following result. . A portion of it macerated in boiling distilled water, for twenty-eight hours, yielded a pale straw-coloured, ‘slightly mucilaginous infusion, which was nearly insipid, and of a disagreeable odour. " The METHOD OF PACKING PLANTS FOR EXPORTATION. 345 The infusion of litmus was reddened when added to it. ' With the nitrate and acctite of barites, insoluble precipitates were thrown down, as was also the case with the acetite of Jead. Sulphate of iron gave a very slight olive tinge to the infusion, after standing eight hours; and with the solution of gelatine, a small quantity of a whitish flocculeat pre. Cipitate was formed, after standing twelve hours. ‘The oxalic acid, a solution of pure ammonia, and the nitrate of silver, produced no effect on the infusion. The conclusion to be drawn from these results is, that the moss contains in its composition, beside the ordinary principles of vegetables, a very small portion of gailic acid, and of tannin, some sulphuric acid in an uncombined state, mucilage, and extractive matter. No inference can, theres fore, be drawn from these results, which explains in any degree the effects of the moss in preserving the vegetables that are enveloped in it; nor is there any effect produced jn the air by it, more than is. produced by mosses in general, when in an uncorrupted state; other causes to explain the preservative property of the moss must therefore be looked for, and these are to be found, in my opinion, in the pecu- liar qualities of the moss, connected with its own existence as a living plant. Plants which are taken from the earth, and packed up to Plants will not be sent abroad, or to any distance so pan Petes as tg roonate a keep them for some length of time in the package, will not yegetate when again taken out of it and planted, unless some degree of vitality has been preserved during the period that they haye been out of the ground, To preserve this, four circumstances are essential in the Circumstances packing material; softness, in order that the delicate parts}; eae = of the enveloped vegetable be not injured; looseness, that a _gertain portion of air be contained in it, and that an equal _ temperature may be preserved ; moisture; and the power of resisting fermentation, and the putrefactive process. All of these circumstances this moss possesses in a remark~ Bog moss emi- able degree; its power of absorbing and retaining mois- “iad POSSESSES _ ture is more considerable than that which perhaps any other moss possesses, it is light, soft, and loose in its texture, and its vitality is so considerable, as to carry on the powers of 346 Theory of its action. Various fruit trees sent to Sierra Leone, packed in this MOSS, with success, ¥ METHOD OF PACKING PLANTS FOR EXPORTATION. of vegetation, and consequently to enable it to resist fers _mentation and putrefaction for a very great length of time. Placed under such circumstances, the plants, which are packed up in the moss, enjoy a kind of life in some degree similar to that enjoyed by an animal in a torpid state, the functions of life are supported at a very low state, but still sufficient to preserve them in a situation to be acted upon by favourable circumstances, when again planted. Such is the theory I have formed of the effect of this moss in pre- ‘serving plants; the many necessary calls of my profession have not allowed me time sufficient to investigate the sub- ject, with all the attention I could have wished to have bestowed on it, and must also plead my apology, for the hasty manner in which my opinion is presented to you. I consider the discovery of much value, both to ey and agriculture. Believe me, Yours truly, . A. T. THOMPSON, Dear Sir, IN addition to the account which I delivered 86" you, re. specting my method of packing plants for exportation in the sphagnum palustre moss, I beg leave to observe, that, at the time the case was packed up, which I sent to the Adelphi in January last, a similar package was sent from me to Sierra Leone, by desire of the African Institution, who wished to introduce into that colony the mulberry tree — for feeding silk worms; also different kinds of vines, and other fruit trees, amounting in the whole to nearly fifteen hundred trees. | They arrived there in about four months after the packs age was made up, and the trees were planted under the di- rection of a gentleman, to whom I gave a copy of the in- structions, which accompanied my former letter to you of last January. “The following account of them has since appeared in the African Herald. ‘¢ A number of fruit and other trees, among which are the white and red mulberry, vires, &c., have been sent from London, by order of the eietaia Institution; all of which are at present growing here, METHOD OF PACKING PLANTS FOR EXPORTATION, 347 here, in a very flourishing state; anda piece of ground is clearing in the mountains, to which they are intended to be removed the next season.” I requested the gentleman, to whose management the African plants plants were entrusted, to acquaint me how they succeeded, sent to England and to use the same moss in packing up for me some of the moss, wild plants of that neighbourhood, which he did in June lasts and at the same time I received a letter from Mr. Macaulay of that place, with the follow «¢ intelligence, *¢The plants which were bought of you, and sent out by _ the African Institution, all thrive very well, except the tea tree, sour sop, and afew others. The mulberries, &c., grow most luxuriantly; most of the trees have been re- moved to a more temperate situation, about three miles hence, where the remainder will soon also be planted.” This letter arrived by the Derwent, captain Colombine, and auieenaele who also brought me a box of plants packed up in the oe moss, which had been previously scut with the above; and although the package did not arrive at Brompton before the Sth of October Jast, the plants were in a fine state of vegetation, and are now growiug in my hot-house; and even the moss itself had preserved its vegetative state, and vd was perfect. I have been thus particular in my description of the fact, as it is a corroborating proof of the utility of this moss for such purposes; and as the removal of trees cannot be other- wise effected in long voyages, without great eagense. and ' inconvenience. . ‘Lam, with great respect, Dear Sir, Yours very truly, WILLIAM SALISBURY. Reference to Mr. Salisbury's Method of managing Plants, ~ we _ after they are removed from the Package. See Plate 1x, Fig. 2, 3. The plan fig. 2, at the bottom of. plate IX, saraiionte, Method of ma- aging h on a sinall scale, Stems of the beds and alleys, with the at whe : plants as first set. The beds, aa, are to be made on level their arrival. ground, each bed to be five fect wide, with a space, bbb, between 348° < Directions for pruning them. Plants kept alive in the moss nine months. METHOD. OF PACKING PLANTS FOR EXPORTATION. between each for a road. A portion of the earth is to be thrown out of the five feet beds, upon these roads, so as to raisesthem four inches higher than the beds, as shown in the plan; C represents the plants as first set out, with an arched cover of canvas cloth over them; D shows the plants when they have grown in the beds for some time, and in a'state ready for planting out, To illustrate the mode of cutting or pruning the plants, after they are removed from the package: fig. 3,, No. 1, is supposed to bea fruit tree, of one year’s growth from the graft, that is a maiden plant. It is to be cut down as is re- presented in No. 2, and the next season’s growth will form the tree No. 3. When it is fit to remain as a dwarf, or if pruned, as is represented in No. 4, it will form astandard, or such as are usually planted in orchards with high stems, in order to be out of the reach of cattle. No 5is supposed to represent any small tree, that has not been grafted, but cut down for planting. No. 6 is the form it will make the following season, when it may be left; or, should it be in. tended for timber, or have a crooked stem, cut it close down to the ground as at No. 7, and it will throw up se- veral shoots, which should be all cut off but the strongest, and that will make the tree No. 8., This may afterward be kept trimmed up to a single "Ga, 3 and a tree be formed much better than in any other mode. N. B. The packages of plants, Nos. 1 and 2, men- tioned in Mr. Salisbury’s first letter, were opened and exa- mined by the committee of agriculture, on the 16th of January, 1809, when all the plants appeared to be in a state fit for vegetation. The boxes were then closed, and placed in the society’s model room, and opened again on the 30th of May, at the distribution of the rewards of the society; the plants were then in a state fit for growth, hay. | ing formed both new roots and branches during their con- finement. It appears, therefore, that the plants were, from their first enclosure by Mr. Salisbury, thus preserved nine months out of the earth. : V. Description ~ APPARATUS FOR CLEANING CHIMNEYS. : Ws Description of an Apparatus used at Sheffield for cleaning Chimneys: by Mr. Samueu Roserrs, Chairman of a Committee appointed at that Place for encouraging the Sweeping of Chimneys without the use of Climbing-boys*. Tre two brushes, Plate X, fig. 1, and 2, are those which at present appear to answer best the intended pur- pose. Fig. 1 is the easiest to work in difficult chimneys; but-in those which are tolerably straight No. 2 will be found the more convenient, as it clears itself better of the soot in ascending. Soldered on the inside of the iron hoop A, at dis a hollow iron tube, going through the wooden balls B. The nut C screws upon the upper end of the hollow tube, through which the rope passes, and fastens the whole together. The balls B are put upon the tube in separate parts, divided at d, for the conveniency of putting Apparatus for cleaning chinineys. in and replacing the brush part F, which is composed of | bristles, whisk, and whalebone. ‘The whisk (which should be well selected for the purpose) is in the middle, on each side of which, above and below, is arow of whalebone, — split thin, with the flat sides towards the whisk, and above and below the whalebone are bristles. Care must be taken that the whole is not too thick and strong, otherwise it will be difficult to get in and out of the pipes on the tops of the chimneys; where they are pressed together between the balls B, they should not be thicker than three eighths of aninch. Great care must also be taken, that the parts of the brushes are well fastened together, and firmly fixed between the balls B, so as not to be loosened in working. The diameter of the balls B is three inches. The distance * Abridged from. the Trans. of the Soc. of Arts, vol. xxvii, p. 209. The Society, anxious to relieve the sufferings of humanity, have attended with much pleasure to the ender yours of the inha- bitants of Sheffield, and cooperate with them i in their attempts to supersede the necessity of employing climbing boys; they have, therefore, immediately on receiving the following communication, ordered it to be inserted in their volume, and an explanatory en- graving of the machinery employed to be annexed. between 350 _APPARATUS FOR CLEANING CHIMNEYS: between the two brushes FF, in drawing fig. 2, is about four inches. ‘The wooden tubes D, (which are about one inch in diameter,) through which the rope passes, should not be too long; the shortest next the brush should not exceed fifteen inches. They should gradually increase in Jength as they recede from the brush to the bottom, where they should not exceed thirty inches. The brush, fig. 3, is a good deal similar to a bottle brush, the handle about four feet long, made of whalebone, wrapped with iron or brass wire, the brush part made of bristles only. It will be found to be very useful in cleaning short flues, &c. in _ Kitchen chimneys. * Fig. 4 is a kind of tent, within which the machine may Contrivance for he worked. It will be found useful in rooms, where it is ’ preventing the gh i p soot from Aying particularly desirable, to prevent the least particle of soot into theroom. from escaping. ‘The-cross bars FE are of oak, about one . inch and a half broad, and half an inch thick, turning upon an iron pinat f. GG are two small iron rods, slip- ping upon pegs at h, to each of which is suspended a linen curtain, the one next the chimney, H, a short one, the other, as shown by the dotted line I, a long one, reaching to and resting five or six inches upon the floor. ee are — small pegs, which, when the bars [i are closed, fit into | the notches gg, so as to stop the bars in the proper place, - | and prevent their being opened the wrong way. When the _ bars KE are opened, they stretch the tapes K, which are fastened to the tops of the bars h, and are about three feet six inches long, to which extent only they suffer the bars to open. When thus extended, and placed in the. proper situation, a loose sheet, of the same kind of linen . as the curtains, is thrown over, and hangs down over R the tapes, and upon the floor at each end, buttoning to — the curtains at the corners, so as to form a complete tent, 4 about five feet long, four feet wide, and five feet high, with, ~ in which both the man and the boy can stand with the mae chine to work it VI. Abstract ee, ee ie = ol ee oe 4 ACTION OF NITRIC ACID ON INDIGO. 351 VR Abstract of a Paper on the bitter Substances formed by the Action of Nitric Acid on Indigo: by Mr. Curyrevr*. § yi. Berore I recite my experiments on the bitter Action of nitri¢ and acid substances, that are obtained by treating indigo 2°4 0” indigo examined. _with nitric acid, I will briefly advert to the labours o abe a) _ wood was converted by nitric acid into a bitter substance, priee the 20th of Noy., 1809, others on the same subject at different periods. 2. Mr. Haussman was the first, who made known the for. Amer from it, mation of the bitter principle by the action of nitric acid -onindigo. Mr. Welther afterward obtained it from silk by and from silk. means of the same acid, described its principal properties, and gave it the name ar amer. 3. Messrs. Proust, Fourcroy, and Vauquelin, have shown Almost all in several papers, that almost all organic substances, into "Sic sub- stances yield it, the composition of which nitrogen enters, yield Welther’ S and frequently amer, and frequently benzoic acid. benzoic acld. Messrs. Fourcroy and Vauquelin studied with great at- Properties of. tention the properties of the amer obtained with indigo. papi ro They observed, that it was acid; and that it was to be con- Vauquelin. sidered as a superoxigenated hydrocarburet of nitrogen, forming with pure potash a detonating compound, which appeared not to contain any nitric acid, as Welther had said. They observed farther, that, if the action of the nitric acid on the indige was stopped, before the whole of the amer was formed, an acid was obtained, which sublimed “in white acicular ony stale and appeared much to resemble benzoie acid. 4. Mr. Hatchett, in his learned researches concerning the Mr. Hatchett’s * action of sulphuric and nitric acids on vegetable compounds, #Acial tannin. made known several products, that precipitate gelatine as tannin does: and on account of this property, com- ‘bined with several others, he called them artificial tanning matter. 5. I observed in the year 1808, that the extract of Brazil Action of nitric acid on. brazil, a Chim, vol. Ixxii, p, 113. Read to the National In- that and on aloes, Supposed acid from indigo. ‘Inquiry insti- _ tuted concern- ing it. Indigo treated with nitric acid. Products distilled over. Matter in the Tetort. ACTION OF NITKIC ACID ON INDIGO. that differed from the amer of Welther: and considered it as a compound of nitric acid, amer, and artificial tannin. 6. Mr. Braconnot, in a paper on gum-resins, speaks of an acid, which he obtained with aloes and nitric acid. He remarked, that this acid bore some analogy to the amer of indigo, und also to an orange-coloured substance, that Messrs. Fourcroy and Vauquelin had formed with muscular flesh and nitric acid*., 7. In the month of January, 1809, I resumed my exa~ mination of the amer of Brazil wood, in order to find how far it resembled the aloetic acid of Mr. Braconnot, when Mr. Vauquelin communicated to me a letter, in which he was informed, that Mr. Moretti, professor of chemistry at Udina, had obtained, by distilling indigo with nitric acid, an acid, that formed a detonating compound with potash, soda, the oxides of iron, lead, silver, &c. It was added, ythat Mr. Moretti considered it as a new acid, because it could not be confounded with the benzoic, which Messrs. Fourcroy and Vauquelin said they had formed with indigo. Mr. Vauquelin was desirous, that I should repeat these ex. periments; and at the same time requested me to examine, whether these acid and detonating products did not owe their properties to some nitric acid, which om retained in | combination. § II. 8. Into a retort I poured four parts of nitric acid at 32° [1-283] diluted with four parts of water. A re. ceiver being fitted to it, I placed it on a moderately warm sand heat, and added gradually two parts of Guatimala indigo coarsely pounded. The mixture grew hot, and a quantity of nitrous vapours, carbonic acid, &c., was evolved. Fearing the action would become too violent, I removed the apparatus to a cold sand bath, and left the substances to themselves for four and twenty hours. 9. During this time nitric acid, prussic acid, and a small quantity of yellow bitter mates had pail into the ree ceiver. 10. The liquor, that remained in the retort, was of a reddish yellow, and two concrete substances floated on it. ¥* See Journal, vol. xxvii, p. 36t. 3 : ; The ACTION OF NITRIC ACID ON INDIGO. 353 The most abundant had the appearance of a resin. The other was of an orange-colour, and disseminated in this in the form of clots. These were both separated from the li- quid, washed with cold water, and then boiled. The resin- ous matter congealed on cooling;.and the orange-coloured substance, after having dissolved, fell to the bottom in small grains, which did not adhere to each other. 11. The water, that had been employed to separate these The liquid two: substances, was added to the liquor (10) left in the4stilled. retort, and then distilled. Nitric acid, prussic acid, amer, Products, and a little ammonia, passed into the receiver. The con- Yjelded crystals -centrated liquor on cooling Jet fall crystals formed of the °f amer and an camer of Welther, and of the benzoic acid of Messrs. Fourcroy and Vauquelin. Having dissolved these in hot water, I obtained by cooling the crystallized acid, retaining alittle amer; and by evaporating the liquid fine yellow scales of amer. 12. The liquid, which had furnished the crystals (11) of Fat oil from amer and acid, after boiling down let fall a red liquid sub- eek ay. stance ichembling a fat oil. . 13. The supernatant liquor (12) was evaporated to dry- More of this, ness, and hot water poured on the residuum. Oxalate i. of Sime was left undissolved; and the water, on cooling, let fall some oily matter, and afterward a yellow sediment, which was pretty soft, and differed from the oily matter only | in the proportion of its principles. 14. I shal! now proceed to examine, Ist the amer; 2d, The products the acid substance, which has been compared to. benzoic mined. ‘acid; 3d, the resin. The other products being only come pounds of these three, I shall not speak of them under se- parate heads; but I intend ina future paper to return to the substance of an oily appearance. § INL. Art 1. Of the Amer. 15. The scales of amer, which I mentioned (11), re- The amer im- tained a little resin, whence they derived a deep yellow?" colour; and asmall quantity of the acid, which has been called the benzoic, but which I shall desigunta under the name of volatile acid. SupPLEMENT.—VoL. XXX. Aa When -products. ° ‘354 ‘ACTION OF NITRIC ACID ON INDIGO. Its properties When the amer is very pure, it is white inclining to when pure. straw-colour. Its solution in water is not reddened by salts of iron ata maximum. ‘That which was employed in the following experiments had been boiled in nitric acid: afterward crystalized repeatedly; combined with potash, and then separated from it by muriatic acid; and lastly crystallized, till, when redissolved in water, it no longer precipitated solution of silver. Action of heat 16. The amer, being gently heated in a common phial, OniAts sublimed in little needles, or scales, of a white colour in- clining to straw-yellow. Thrown ona redhot iron it took fire, and left a coal, which melted. If exposed to a red heat in a retort, a pretty strong smell of nitrous acid and of prussic acid is evolved. Apparatus for To examine the products of the amer subjected to the examining its “aétion of heat, I contrived an apparatus consisting of a glass ball surmounted with a tube, which terminated under a jar filled with mercury. Into the ball I introduced 2 dec. {3 grs.] of amer, more would have burst it, and fastened the tube to the jar by means of a wire. Heat applied. 17. When the apparatus was thus arranged, I heated the ball with a redhot coal: the amer melted, grew black, and took fire; a light coal remained; and aqueous vapour, gas, and a little charcoal passed into the receiver. Gaseous pro- The gaseous product reddened litmus paper. It had the sia smell of nitrous acid, mixed with that of prussic; and I analysed it in the following mode. I first passed some water into the jar, and a slight absorption took place. ‘ Carbonic and When this appeared to be at an end, I shifted the water to \— prussic acids. another jar filled with mercury; and found, that it had — dissolved a portion of amer, which’ had been volatilized — without decomposition, “sorne carbonic acid, and some ~ Mode of detect- prussic acid. To detect the latter it was necessary, to sa- ing the latter. turate the liquid with carbonate of potash; and pour it “into a small glass retort adapted to a receiver, in which ‘were some threads twisted together, impregnated with greea ‘sulphate of iron, and afterward dipped in a weak solu- tion of ‘potash. On distilling, water and prussic acid passed over ; and the thread, after having been washed with — ‘weak muriati¢’agid, became blue. (If sulphate of iron ACTION OF NITRIC ACID ON INDIGO, 355 were mixed directly with the liquid saturated with potash, no prussian blue was obtained). The residuum of the distillation was reddish, and gelati. Residuum. nized. Sulphuric acid evolved from it a smell of prussic acid, mixed with that of nitrous acid. The water therefore had dissolved, beside the undecom- Nitric acid and posed amer, carbonic acid, prussic acid, and nitric acid; ?}ittleam- and I have every reason to think, that it contained a little so a ammonia. 18. The gaseous residuum insoluble in water was placed The gaseous’ in contact with a solution of potash for twenty-four hours, Beep ents in order to abstract from it the carbonic and prussic acid, were A that it might still retain. After this it was carefully wash. ed. In this state it did not redden infusion of litmus; but @s soon as it was exposed to the air, it reddened it, and produced a pretty strong smell of nitrous acid; so that it must have contained nitrous gas. It burned in the same manner as otly hidrogen. I had observed several times, that this residuum extinguished burning substances, because then it contained a great deal of nitrogen gas; and at other times, that it burned like carbonic oxide gas. It appeared, that these differences were owing to the degree of rapidity, with which the amer was decomposed. The gaseous residuum insoluble by water or potash, there nitric oxide, fore, consisted of nitrous gas, inflammable gas, and nitro ieee and gen. As Iwas not able to make an accurate analysis of this residuum, I cannot say whether the whole of the ni. trogen came from the air in the apparatus, the oxigen of which was converted into nitric acid by the nitrous gas; or whether part of it arose from the decomposition of the ~-amer. 19. From these facts it appears to me, that amer is a Composition of compound of nitric acid, and a vegetable matter, probably*™°™ ‘of an oily or resinous nature. Perhaps it may be objected, that the nitrous gas obtained may be formed during the process, by the compression the gasses undergo: as is the ‘case when hidrogen is detonated with oxigen containing ni- ‘trogen in Volta’seudiometer, or in a glass globe for the re- composition of water: but the compression of the gasses in ‘these apparatuses appears to me to be much greater, than 1) Aag they 7 356 ACTION OF NITRIC ACID ON INDIGO. they experience in the detonation of amer.. However, the facts that follow, and those which I purpose to relate, will show, thatit is more natural to consider amer as a coms pound of nitric acid, than as a substance formed directly of oxigen, hidrogen, carbon, and nitrogen. Actionof potash 20. Amer is much more soluble in hot water than in cold, eae Its solution is acid, very bitter, and even a little astringent. If it be mixed with a concentrated solution of potash, small needly crystals of a gold colour are obtained, which area compound of amer and potash, and have been described by Welther, Fourcroy, and Vauquelin. These crystals A detonating detonate loudly when heated. They cannot be heated in a . «compound aed glass ball without breaking it to pieces. If 15 cent. [2 grs. | be heated in a small assay matrass, aloud detonation is pro- duced, the vessel is filled with soot, and a smell of prussic acid is emitted. If the matrass be closed as soon as the de- tonation has taken place;-and, when it is cool, a solution of potash be poured in, and afterward of green sulphate of iron, prussian blue will be obtained. Dissolved in 100 dec. of boiling water dissolved 7 dec. of the detona- wale ting matter. On cooling, a great part of the latter sepa- rated in the form of small needles. The solution was not acid, and did not appear alkaline. Properties‘of This compound is decomposed by nitric or muriatic acid this compound. a¢ 4 boiling heat, as Messrs. Fourcroy and Vauquelin obs served; and, on cooling, the amer crystallizes in white scales, inclining to straw-colour. But a very remarkable No such thing ‘fact, which proves, that there is no such thing as elective ede attraction, is: if you take a solution of potash, supersa- turated with nitric or muriatic acid, mix with it amer, eva- porate to dryness in a small capsule, and dissolve the re- siduum in hot water, you will obtain on cooling small de. tonating crystals, of a gold colour, formed of amer and potash; whence it follows, that amer decomposes nitrate and muriate-of potash. Causes of these. Thus we have two opposite effects, that occur within a opposite effects: ange of temperature the extremes of which are by no means remotes; and which are easily explicable, if we attend to the circumstances. In the first, we perceive that the amer must first separate, since potash is capable of forming with oe , the - ACTION OF NITRIC ACID ON INDIGO. 357 the nitric or muriatic acid a compound more soluble in water than amer: the latter therefore is separated by the force of crystallization. In the second experiment, the amer and potash, being more fixed than the nitric or muriatic acid, combine; while the acid flies off by the expansive power of heat. Amer combines very well with ammonia, and the result Union of amer is small yellow scales, which scarcely detonate on being with ammonia, heated. 2). Amer unites with lime, barytes, and strontian, and the earths, forms compounds soluble in water. It requires but a very small quantity of lime, or even of carbonate of lime, to turn the crystals of pure amer yellow. The mere contact of common paper is suflicient, to produce this effect. 22. Amer dissolves oxide of silver, and forms with it oxidc of silver, needles of a rich gold colour; but they grow black by ex. posure to air, were then directly inverted: and the seeds were conse- quently placed beneath the mould; but each seed was so far depressed into the mould, as to be about half covered: by “which means each radicle, when first emitted, was.in con- j tact with the mould above, and the air below. Water was then introduced through the bottom of the inverted pot, in sufficient quantity to keep the mould moderately moist ; and, the pots being suspended from the roof of a forcing house, the seeds soon vegetated. In former experiments *, wherever.the seeds were placed The radicles to vegetate at rest, the radicles descended perpendicularly pio ie ak downward, in whatever direction they were first protruded ; shot up fibres but under the preceding circumstances they extended hori- ei ce zontally along the surface of the mould, and in contact with ti “it ; and in a few days emitted many fibrous roots upward .into it: just as they would have done, if guided by the instinctive faculties and passions of animal life; aud as I concluded before I made the experiment that they would do, under the guidance of much more simple laws, the mode of operating of which I shall endeavour to explain. Whatever be the machinery, by which the sap of trees Ascending sap is raised to the extremities of their branches, it is obvious, ae peli that this machinery is first put into action by the stems and stems and branches, and not by the roots; for the graft or bud, when. 2h ever it has become fully united to the stock, wholly regu- | lates the season and temperature, in which the sap is to be put in motion, in perfect independence of the habits of the stock ; whether these be late or early. If all the branches and the quan-_ of a tree, exclusive of one, be much shaded by'contiguous inves sbinty tor trees $+, or other objects, the branch which is exposed employ it, to to the light attracts to itself a large portion of the ascend. he ca a . ing sap, which it employs in the formation of leaves and : * Phil. Trans. 1806, p. 1: or Journal, vol. xiv, p. 409. + Phil. Trans. 1805 and 1809: or Journal, vol. xii, pp. 233, 308 ; vol. Xxy, p. 118. : ! vigorous STA DIRECTION OF TRE GROWTH OF ROOTS. vigorous annual shoots, while the shaded branches become languid and unhealthy. The motion of the ascending current of sap appears therefore to be regulated by the ability to em« ploy it in the trunk and branches of the tree; and this current passes up through the alburnum, from which substance the Proper fond buds and leaves spring. Butthe sap, which gives existence eriables the root to, and feeds the root, descends through the bark*: and pees nae ie if the operation of light give ability to the exposed branch to scending sap. attract and employ the ascending or alburnous current of sap, it appears not improbable, that the operation of pro- per food and moisture in the soil, upon the bark of the root, may give ability to that organ to attract and employ the descending, or cortical current of sap; and if this be the case, an easy explanation of all the preceding pheno. mena immediately presents itself, Descent ofroots A tree growing upon a wall, and unconnected with the as aoe earth, will almost of necessity grow slowly, and as it must ed for. be scantily supplyed with moisture during the summer, it will rarely produce any other leaves, than those which the buds contained, which were formed in the preceding year, Some of the roots of a tree, thus circumstanced, will be less well supplied with moisture than others, and these will be first affected by drought: their points will in consequence become rigid and inexpansible, and they will thence gene. rally cease to elongate at an early period of the summer. The descending current of sap will be then employed in promoting the growth and elongation of those roots only, which are more favourably situate, and these comparatively with other parts of the tree, will grow rapidly +. Gravi- ‘tation will direct these roots perpendicularly downward, and the tree will appear to have adopted the wisest and best _ plan of connecting itself with the ground: and it will really have employed the readiest means of doing so, as effec. tively as it could have done, if it had possessed all the feel- ings and instinctive passions and powers of animal life. The * Phil. Trans. 1809, p. 169: or Journal, vol. xxv, p. 119. + We do not find here, however, “the. proper food and mois- _ ture,” to ‘ give ability to the root to attract and employ the de- scending or cortical current ofsap.” C. subsequent DIRECTION. OF THE GROWTII OF ROOTS. — 375 eibsequent vigorous growth of such a tree is the natural consequence of an improved and more extensive pasture. _ When the seeds of the carrot and parsnep, in the expe- Growth of the riments I have stated, were placed in a poor superficial soil, cn ae but which permitted the roots of the plants to pass readily explained in through it, these were conducted downward by gravitation ; ‘he St case, while the plants grew feebly, because they reccived but little nutriment. The roots were in a situation analogous to that of the stems of trees in a crowded forest; and when the leading fibres of the roots came into contact with the rich mould, they acquired a situation correspondent to that of the leading branches of such trees, which are alone exposed to the light. The form of the roots of the plants was consequently long, slender, and cylindrical, like the stems of such trees. The roots of the one ‘required the actual contact of proper soil and nutriment; and. the branches of the other required the actual contact of light, ' to promote their growth. When, on the contrary, the seeds of the preceding species and in the of plants were placed in a rich superficial soil, their situa. °°°°"* tion was analogous to that of a tree fully exposed, on every “side, to the light; the branches of which would be extend. ed, in every direction, immediately above the surface of the ground: and as the;fibrous roots of the plants came into contact with the subsoil, which was not well calculated to promote their growth, their situation became analogous to that of shaded branches; and they consequently ccased to extend downwards. The fibrous roots of a tree, under similar circumstances, would have extended along the’ Jower surface of the favourable soil; but after these roots had much increased in bulk, they would be found partly compressed into the subsoil, however poor and unfavour- ‘able, provided it contained no ingredients actually noxious. In obedience to similar laws, the roots of an aquatic tree Growth of will not extend freely in dry soil, nor those of a tree which rection fei reguires but little moisture in a wet soil; and on this ac- moisture. count the roots of the one will appear to have sought, and those of the other to have avoided, the contiguous water ; though both, in the first period of their growth, pointed their roots alike in every direction, Whea 376 DIRECTION OF THE GROWTH OF ROOTS. « . Explanation of | When the seeds of the bean, in the experiments I have re airy described, were placed to vegetate beneath the mould of an Ca inverted pot, a sufficient quantity of moisture was afforded by the mould, to occasion the protrusion of the radicles: but as soon as the under points of these had penetrated £ through the seed-coats, their surfaces were necessarily ex- ; posed to dry air, and were consequently rendered rigid and inexpansible; while their upper surfaces, being in contact with the moist mould, remained soft and expansible. If both the upper and lower surfaces of the radicles, at their _ points, had been equally well supplied with moisture, gra- vitation would have attracted the sap to the lower sides, where new matter would have been added; and the radicles would have extended perpendicularly downward, as in for- mer experiments; but the influence of gravitation was, toa great extent, counteracted by the effects of drought upon the lower sides of the radicles, nearly as it was counteracted by centrifugal force, when made to act horizontally *. As soon as the radicles had acquired sufficient age and “maturity, efforts. were made by them to emit fibrous roots; — ‘when want of proper moisture on the lower sides prevented their being protruded, in any other direction, except up- wards. In this direction therefore they were alone emitted, (as I was confident that they would before I began the ex. periment) and having found proper food and moisture in the pots, they extended theniselves upward through more than half the mould, which these contained. This experiment was repeated, and water was so con. Theexperiment repeated with stantly and abundantly given, that every part of the radicles ; ee was kept equally wet; and they then became perfectly obedient to gravitation, without being at all influenced by the mould above them. | - In other experiments, pieces of alum and of the sul- Sulphates of : alum) iron, and phates of iron and copper were placed at small distances a not perpendicularly beneath the radicles of germinating seeds, ec. € pti of roots Of different species, to afford an opportunity of observing, but by actual whether any efforts would be made by them to avoid ah poisons; but they did not appear to be at all influenced, * Phil, Trans. 1806, p. 6: or Journal, vol. xiv, p. 411. except is Lee DIRECTION OF THE GROWTH OF ROOTS, ST consul by actual contact of the i injurious substances. The Food and mois- ‘growth of their fibrous lateral roots was, however, ob- Sees pale viously accelerated, when their points approached any to promote considerable quantity of decomposing vegetable or animal erowe matter: and when the growth of the roots was retarded by want of moisture, the contiguity of water, in the adjoin- ing mould, though not apparently in actual contact with ; them, operated beneficially: but I had reason to suspect, that the growth of roots was, under these circumstances, promoted by actual contact with the detached and fugitive particles of the decomposing ems and of the evaporating water. The growth and forms assumed by the roots of trees, of Growth and form of roots every species, are, to a great extent, dependent upon the j,oaigeq by the quantity of motion, which their stems and branches receive motion im- from winds; for the effects of motion upon the growth FG data the root, and of the trunk and branches, which I have de- vanes scribed in a former memoir, are perfectly similar*. What. ever.part of a root is moved and bent by winds, or other causes, an increased deposition of alburnous matter upon that part soon takes place; and consequently ‘the roots, which immediately adjoin the trunk of an insulated tree, in an exposed situation, become strong and rigid; while they diminish rapidly in bulk, as they recede from the trunk, and descend into the ground. By this sudden diminution Hence trees __ of the bulk of the roots, the passage of the descending re. exposed are rendered sap, through their bark, is obstructed ; and it in consequence more secure; generates, and passes into many lateral roots; and these, if the tree be still much agitated by winds, assume a similar form, and consequently divide into many others. A kind — of net-work, composed of thick and strong roots, is thus formed, and the tree is secured from the dangers, to which its situation would otherwise expose it. Al In a sheltered valley, on the contrary, where a tree is while sheltered surrounded aud protected by others, and is rarely-agitated —. only by winds, the roots grow long and slender, like the stem slender roots, and branches, and comparatively much less of the circulat. _ ing fluid is expended in the deposition of alburnum be- : # Phil. Trans. 1803, p. 7. neath mn 398 DIRECTION OF THE GROWTH OF ROOTS. neath the ground, and hence it not unfrequently happens, that a tree, in the most sheltered part of a valley, is up- rooted; while the exposed and insulated tree, upon the adioilitdg mountain, remains bare beg by the fury of the storm. Plants void of [In all the preceding arrangement, the wisdom of nature, ESA 1 and the admirable simplicity of the means it employs, are Jogous to those conspicuously displayed; but I am wholly unable to trace ef animal life. 46 existence of any thing like sensation or intellect in the plants: and I therefore venture to. conclude, that their roots are influenced by the immediate operation and contact aa of surrounding bodies, and not by any degrees of sensation and passion analogous to those of animal life; and I reject the latter hypothesis, not only because it is founded upon assumptions, which cannot be granted, but because it’ is insufficient to explain the preceding phenomena, unless seedling plants be admitted to possess more extensive in~ tellectual powers, than are given to the offspring of the most acute anima!. A young wild-duck or partridge, when it first sees the insect upon which nature intends it to feed, instinctively pursues and catches it; but nature has given to the young bird an appropriate organization. The plant, on the contrary, if it could feel and perceive the objects of its.wants, and will the possession of them, has still to contrive and form the organ by which these are to be approached. The writers, who have contended for the existence of sensation in plants, appear to have been sen- sible of the preceding and other obstacles, and have all be. trayed the weakness of «their hypothesis, in adducing a few facts only which are favourable to it, and waving wholly the investigation of all others. In the description of the ‘preceding experiments, I fear that I have been tediously minute; but, as I have selected a few facts only from a great number, which I could have adduced, I was anxious to give as accurate and distinct a view of those I stated, as possible. Iam, dear Sir, with great respect, sincerely yours, Downton, Jan, 15, 1811. THOS, AND. KNIGHT. _ IX. On. ? s - ON KEEPING DISTILLED WATERS. 379 IX. On the mucilaginous State of Distilled Waters: by Mr. Bucnoxz *. ‘ [tr is well known, that distilled waters spoil more or less Distilled Os quickly. They become mucilaginous, deposit a flocculent *Pt t spoil. sediment, lose their smell and taste, and often acquire a fetid smell and putrid taste; all which appears to take place most frequently in waters destitute of essential oil. It is known too, that this change proceeds more rapidly Cireumstanceé. in proportion as the water contains but little oil; and if vourable to” the distillation have been performed hastily, the flocculent = sediment forms presently after, as in elder-flower water,’ linden water, &c. Distilled waters spoil equally in open vessels, and in ves- They spoil in sels closely stopped: but the change takes place more yea tebel speedily in very close vessels. We have two questions then to solve: What is the cause of this alteration? And what are the means of obviating it? As waters distilled with the greatest care undergo this The oil sup- change, it may be suspected, that the oil is decomposed, eames and converted into mucilage +. Bauhoff’s experiments tend to support this opinion. He dissolved in common distilled water, essential oil of peppermint, of fenncl, of lemons, and of valerian. These waters, ‘which were perfectly limpid, were kept in-closely stopped bottles at the common temperature; and in a few weeks they became turbid, let fall a flocculent, mucilaginous sediment, and lost their ~ smell. A fetid smell however does not always indicate the total But they may : baie : : be fetid without disappearance of the essential oil. Bauhoff examined some 7°). ney spoiled rosewater, that had been kept in a close vessel. destroyed. The surface of this water was covered with a black pellicle, # Ann. de Chim, vol. Ixili, p. 90. Abridged from Tromsdorff’s _ Pharmaceutical Journal, by Mr. Vogel. ‘+ This appears inconsistent with what is said in the first para- graph. In the experiments of Bauhoff, that follow, as the term dissolved is employed, no doubt sugar or mucilage was used as an intermedium for uniting the oil and water. C, and 380 ON KEEPING DISTILLED WATERS, » and its smell resembled that of sulphuretted hidrogen gas. Being left a few weeks exposed to the open air, the fetid smell vanished, and was replaced by that of roses *. ‘Some rosewater, the putrefaction of which was very bh ittenk Te- “.covered its smell by the addition of a little lime and iron. It appears certain therefore, that the oils in distilled waters change their nature. . Waters, that have-been distilled with too strong a heat, contain lest oil; which would seem to prove, that a part of it has undergone some sort of alteration. Waters that But there are waters, that contain no essential oil, as bic ata those of elder-flowers, borage, nettles, &e. These waters essential oil i IO SDN ds ne ‘he spoil. probably carry up in distillation volatile odorant principles, which approach the nature of essential oils, and are de- : composed still more easily. ° The authors . | But how are these principles converted sie mucilage ? theory. As the flocculent. matter forms more commonly in well stopped bottles, than when exposed to the air, this ques- tion may be easily answered. It is well known, that es. " sential oils exposed to the air are converted into resins. This cannot be employed to explain the phenomenon. We ° must suppose then, that the oil, in passing to the state of mucilage, loses a part of its hidrogen; or that the oil becomes mucilage by uniting with one of the constituent principles of water, which however appears less probable. Perhaps it may be supposed, that the nitrogen of the air combines with the oil, or with the. volatile odorant prin- ciples, to form mucilage. Green matter in. An analysis of the flocculent matter would tend to elu- distilled water. Cidate this point. However the remark made by Priestley , and Sennebicr would still remain to be explained. They both observed a green matter in distilled water exposed to the Freeziug ad- * Mr. Nachet, professor at the School of Pharmacy, long ago vantageousto remarked, that distilled waters, which had been frozen, acquired distilled waters. 4 more powerful smell, and kept longer. . He observed this to be particularly the case with balm, mint, and orange-flower water. Vogel. " ; The experiment of Bauhoff, given in the text, tends to confirm the opinion, that the change is not owing to a decomposition of the essential oil, C, F Rien rays ANALYSIS OF AMBERGRIS. 38I rays of the sun in vessels slightly covered. Sennebier found in this substance a number of smal! worms. The second question remains, that of preventing distilled Best method of oh ae pe Fe Males keeping distiHs waters from spoiling. To prevent this inconvenience as far og waters, as possible, they should be kept in an airy cellar, in wide- mouthed vessels, covered witha paper. Ofice a month the paper should be taken off to renew the air at the surface. It isadvisable, to have these waters in the most concen- trated state possible, so that their surface may be covered with a stratum of the volatile oil of the vegetable, which may afierward be separated by filtration. If thespoiling of distilled waters cannot wholly be prevented. by these means, _it may at least be deferred. X. A new Analysis of Ambergris: by Mr. Bucuorz*. . Tue author first reviews the various analyses, that have Various ana- been made of ambergris, and gives a comparative table ote Spanner results obtained by modern chemists, namely by Rose, Juck, Bouillon-Lagrange, and Proust. He then subjected amber. gris to the following experiments. Water distilled from ambergris acquires a slight smell of Its habitudes this substance, without containing an oil. ‘i aman an Pure alcohol dissolves ambergris entirely, except a smallalcohol, quantity of black pulverulent matter. It dissolves a much larger quantity, if assisted by heat; and lets none fall on cooling. The liquor is then of a reddish brown +. - * Ann, de Chim, vol. Ixiii, p. 95. Abridged from Tromms- dorff’s Pharmaceutical Journal, by Mr. Vogel. _ f When ambergris is treated with a smail quantity of boiling alcohol, and the liquor filtered while hot, a yellowish white grumous substance is precipitated. If Mr. Bucholz did not observe this, it was probably owing to the small quantity, on which he operated. He employed only 20 grs. of ambergris to six drachms of alcohol, which he calls a saturated tincture. Boudllon- _ Legrange. Hither oS 382 ether, potash, and oils. Considered as a peculiar prin- eiple. Benzoic acid probably from sophistication. ANALYSIS OF AMBERGRIS> Ether dissolves it cold, and also leaves the black matter. This solution is not precipitated either by alcohol, or by water. Caustic potash, whether dry or dissolved in water, coms bines very difficultly with one part of ambergris. This spar- ing solubility in potash may be employed as a test, to-distin- guish true ambergris from spurious. . Oil of turpentine and oil of almonds dissolve ambergris very well, if assisted by heat. . Instead of finding ambergris to be a compound of adipo. cere, resin, benzoic acid, and carbonaceous matter, agree- ably to the results of Mr. Bouillon-Lagrange*, the author considers it as a substance swé generés. In the recapitala- tion af his paper, he expresses himself thus: ¢¢ ambergris is a peculiar compound, which is a medium between wax and resin; differing from both in the manner in which it comports itself with alkalis; and approaching the resins, in alcohol dissolving a larger quantity of it than of wax, and in having a resinous aspect when it is cooled after having been melted. The author proposes to call it the ambry principle +.” hia A 0: | * See Journal, vol. vi, p. 179. + If a draehm of ambergris be dissolved in two drachms of boil- ing alcohol, and the liquor filtered while hot, it lets fall on cool- ing that substance, which I have compared to adipocere, because it approaches it nearly in its properties. The supernatant fluid is rendered turbid by water, and reddens a weak infusion of litmus. This property is owing no doubt, as J have said in a former paper, to a small quantity of resin which it contains. I did not think it right therefore, to increase the number of new substances unneces- sarily, by giving to the matter precipitated from the alcohol the name of ambry principle; I was satisfied with considering it as in- termediate between resin and wax. Asto the benzoic acid, I must confess, that I have found none in several specimens of ambergris, which I have analysed since. ‘This leads to the suspicion, that there are manufactories of ambergris, as there are of castar. XI. Process PREPARATION OF PHOSPHORIC ACID. 383 XI. Process for preparing pure Phosphoric Acid: by Mr. Martres, Apothecary at Montauban, and Member of several Societies *. W une physicians devote their studies to the search Improvements after new means of alleviating the sufferings of mankind, 1” Phanmacy it is the duty of apothecaries to second their efforts, by en- deavouring to simplify 0 or improve the preparation of medi- cines. Dr. Lasalle, of Montauban, having employed the phos- Phosphoric acid phoric acid with success in the treatment of some diseases, My medice I endeavoured to supply him with it very pure, in a little time, and without danger, by a process, which I have found to succeed completely: being fully convinced, that we cannot rely with entire confidence on preparations, that | come to us in the ordinary way of trade. We may proceed jn six different ways, to obtain phos- Methods of phoric acid; but five of them are not very easy of execution, Preparing it. and the product is almost always contaminated with phos- phorous acid. \ The sixth, pointed out by Lavoisier, yields a pure phos- Improved phoric acid, but exposes the operator to some danger. This ™¢thod. therefore it is desirable to obviate; which [ have effected by means of an apparatus, that I shall describe before I give an account of my process. _ The neck of a retort, placed on a sand-heat, is to be Apparatus. introduced into the mouth of a receiver, the second neck of this receiver into the mouth of another, and the second neck of this into a curved adopter, the mouth of. which opens in a vessel of water, so as to answer the ok hibis of a tube of safety +. The apparatus being thus arranged, 32 gr. [494 grs.] of Process dee phosphorus are to be put into the retort, through its tu. scribed. bulure; and an equal weight of a mixture consisting of * Ann. de Chim. vol. Ixxiii, p. 99. + The atmospheric air expelled from the receivers by the nitrous. vapours escapes from the mouth of the adopter, which may after- ward be stopped. equal 384 Quantity of nitric acid required, ’ Results. PREPARATION OF PHOSPHORIC ACID. equal parts of concentrated nitric acid and distilled water. A tube of safety is then to be introduced into the same aperture, so that its. toothed extremity shall reach. the bot- tom of the retart. The apparatus is then to be luted, 'and dried. The process is to commence with heating the cuntlbdh till the liquor boils, and the phosphorus melts. A quantity of nitric acid is then to be poured into the funnel, sufficient to produce a level, without flowing into the retort. 8 gr. [ 123-5 grs.] of the same acid are then to be added; which,, by their weight, force into the retort an equal quantity of the hquid, part of which still remains in the tube, without touching the phosphorus. The phosphorus, retained at the bottom by its specific gravity, attracts the nitric acid, but, as it receives only a small quantity at a time, the combustion is slow, and efs fected without danger. ‘ In proportion as the nitrous vapours inthe retort ais minish, a fresh portion of acid is to be poured into the funnel; and this is to be repeated, till the tins. is. completely oxigenated. To effect the perfect combustion of 32 gr. [494 grs,] of ‘phosphorus, I have employed 128.gr. [1977 grs.] of con. centrated acid; or 192 gr. [2965-5 grs.| of what is come monly called fuming nitrous acid. By operating in this manner, we obtain phosphoric det mixed with nitrous gas, and a quantity of superfluous liquid, from which it is to be freed by evaporation, This process takes more time with a retort, than it would with a matrass ; buat the operator is not exposed to inhale the nitrous gas,. The liquid residuum should- have the consistence of a thin. sirup, and leave streaks on the glass, as milk or oil would do. If the process I have just described produce pure phos« phoric acid; if my’simple and ready apparatus secure the operator from the nitrous fumes, and the accidents that might be occasioned by the explosion of the vessels ; this apparatus and this process will no doubt be adopted, and perhaps not be thought uninteresting to those, who are engaged in- chemistry. 1 7 INDEX ® is | Nicholsoris Phalos, Journal, Vol XXX PL pL. — yw SiN “ yD) 3 / Jf 7 : : ae il til Z Wisin Z 44 i a q 1) ttl OL Oh Og, Z VA Es nS, fl] Nicholsons Philos Jouaal Vol INP pri. Ae it ih /. 77 : ‘i : | | P a Oy a 52 => TE aN HIN Hl ii t a : : ee Pe 38) a3 Re ica , Es ey on ) ESA \ I AWW Zz Yt Zt ty ZLffy7 ZF gZ tu fw ee? bins wae) ?. copyf, is ‘ : pty ‘3 Yi buproperd syn op yy LEAD LY LP DY 4 / a \ Wien Les AR pate | xB fh PSS we WVichotsonis, Philos, Journal. Vol. XXX PU.V1. (plat x Oe. boothiow f VA ew! by Golvaniom : bs P N P E: : Pac) 4 Us A LW, : _———— ST ee CHUL iter Re 3 i en sea ge Bul hanpgy yd LY WO fovs/ TP Nicholsons Philos. Jourmat, Vol. XXX PL. pp.3 4.9. Lhe Sudffidld Ui paratid fr? Cleaning Chimneys Ny \\ h \ \\ Ny \ N AY Wi TUF is IMA | Ali AM HOnyl Nt SSSSSSSESSESSS f ! ! } ~ | Mi} | | i \ . ( } | \}} i} \ SS== 6 S—S—S-_ SSS == — | ee eS re TE i VR ae ek pep eene a le S os e aS Ry tu a Phe - yichteeae | Pal N tet Xx, Accum, F. Esq. 239 Acid, acetic, constituent principles of, 71 Acid, carbonic, produced from carbonic oxide, by means of oximuriatic gas, 226 , Acid gas, anew, 28 Acid, nitric, its action onindigo, 351 Acid, oxalic, constituent ingiples s of, 71 Acid, phosphoric, preparation of, 383 Acid, sulphuric, mixtures of with wa- F ter, 319 Acid, yolatife, experiments on, 359, 363 Aconite, experiments on the power and operation of its poison, 301, 324 Acoustics, experiments in, 103, 169 Alloy, native, of gold, 137 Almonds, bitter, experiments on the power of the essential oil of, on the animal economy, 300, 324 Amalgam of mercury and silver, new process for making, 156 Amalgamations, various, 293 Ambergris, a new analyis of, 381 Amer, experiments on, 358, 363 Analyses, mode of performing, appa- ratus, &c., 66—-Cautions, 67—Ex- planation of certain facts relative to, meat Analysis of a stucco for preserving | Stone, 12—Of pus, 17, 118—«Of mu- cus, 25, 113—-Of oxalic and acetic gga 71—Of resin, ‘72—Of olive il, 72--Of crystallized sugar, 72— . a. beech wood, 72—+-Of the mineral ~'waterof Bagnére, 79 Of the water of Ussat, 79—OF the water of Nieder- “brunny; S0—-Of zeolite, 135—-Of a ‘native alloy of gold, 138++Of the ce- _ment of an antique mosaic, 140—Of ‘human bones, 256—Of neutral salts, 260—Of a Chinese gong-gong, 307 =—Of the yellow resin of New Hol- dand, 310—_Of hedge hyssop, 365 =Of ambergris, $981 Vou. XXX. Anderson, A. Esq. on the decomposi= tion of water in two or more separate vessels, 183 Animal substances, dessiccation of, 193, Ants, economy of, 10 Appatatus for cleansing chimneys, 344 Apple, the burrknot, 76<©The Spring- Grove, 77 Aquatinta, Improvement in, 220 Arago, M. 192, 266. Arbor Diane, method of making, 156 _ Artillery at sea, charges of the greatest efficacy for, 81 ; Attraction, chemical, 193 Augsburgh beer, mode of preserving 80 B. Bachelier, M: his process for the-come position of a preservative stucco; “ inquiry relative to, 10 Bagnére, mineral water of, analysed, 79 Bancroft, Dr, E.N, 17, 296; 324 Banks, Sir J. 379.—His account of a new apple,77—-On the forcing houses of the Romans, with a list of fruits cultivated by them, now in our gar dens, 147—+On the horticultural ma- nagement of the sweet or Spanish chestnut-tree, 202 Barber, J. T. Esq, 226 i Barks, various, from India, 276, $79 Barytes, white water-colour prepared. from, 54 zs) Bauhoff, M. 279’ ; Baummé, -M. 156 Bedford, duke of, 273 Beech wood, component parts of, 72 Beer, method of keeping, 80 .«« a8 Bell-metal of China, analysis/of, 807 ° ‘ Belles lettres, lectures on, 239 Belloni, M. 140 Berthollet, M. 10,260, 262—His prize’ question on the specific heat of gases,’ 78—His experiments. on. sound pro- duced in vapour, 171++On chemical’ attraction, 194, .197 , a Cc, Berzelius, % i ee : a a ne an et ee Berzelius, M.on the analysis of differ- ent salts, 260 , Bichat, M 298, 333 Biot, M. 266—On the transmission of sound through solid bodies, and throngh air in very long tubes, 102— On the production of sound in va- ° pour, 169 Blood, passage to, from the stomach, 173 r. Bones, human, analysis of, 256 . Botany Bay, see New Holland Bouillon-Lagrange, M. 156, 381 Bouvard, M. his experiments on the transmission of sound, 105 Braconnot, M. on gum-resins, 352 Brande, Mr. W. 175, 296 Brazil, how affected by the operation of nitric acid, 351 Brewster, Dr. his demonstration of the fundamental property of the lever, peo orl Bristol, medical tures im,’ 79° Brodie, B.C. Esq. 175—On the differ- ent modes in which death is produced by certain vegetable poisons, 295, 524 Broughton, Mr. 296 Bucholz, M. 261—On the mucilaginous state of distilled waters, 379—His new analysis of ambergris, 381 Burrknot apple, account of, 76 Burton, Mr. 113 and chirurgical lec- Cc. Garbonic acid, see Acid Carbonate of lime, new varieties of, 189 Carbonic oxide, see Oxide Caseous matter, constituent principles - of, 73. Cast iron, see Iron. Cathery, Mr. R. his metliod of prepar- ing ox-gall in a concentrated state, for painters, &c. 154 Cement, ancient, analysis of, 140. Chabaneau, Professor, 294 Chaptal, M..10, 53 Charges for marine artillery, 81 Cheese, stucco made from, 10 - Chemical attraction, 193 Chemistry, lectures in, 239 f Chestnut-tree, Spanish, management of, 202 Chevreul, M. on the bitter substances formed by the action of nitric acid on indigo, 351 Chimneys, apparatus for cleansing, 349 Chinese gong analysed, 307 Chiladni, M. his method of estimating the transmission of sound, 104 Chrestien, Dr. 248 Clark, Mr. J. 155, 838 Clement, M. 193, Clennel, Mr. 240 Clift, Mr. 175 Cloud, Mr. J: on the discovery of pal- ladium in a native alloy of gold, 137 Clouds, natural history of, 35 Codiing, a new species of, 77 Conessi bark, 279 Cooke, Mr. 300 u Copper employed as a precipitate of silver, 518 Corston, Mr. W. his account of a sub- stitute for Leghorn plait, for hats &e.. 273 Crotch, Dr. W. 239 Curaudau, M. on the simple nature of oximuriatic gas, 157 * ‘ D. Dalton, Mr. 169, 270 D’Arcet, M. 13<+His analysis of the cement of an’ antique mosaic, found - at Rome, 140 Davy, Dr. H. 157, 261—His theory re- specting oximuriatic gas defended, 2 Davy, Mr. John, 135,.228—His \ac- count of a new ‘gas, with a reply to Mr. Murray’s, last. observations on oximuriatic gas, 25--Answered, 226 Death, how. produced by poisons, {Ps S24 ; Decandolle, M. on \the inclination .of the stems of plants toward the_liglst, 144 ) 1% | Decay in ships, 1 means cae preventing, 287 r Délaroche, . == rN OE: xX: < Pelaroche, Dr. F. his experiments 07 ~ radiant heat, 78—Extract of a letter from, on the same subject, 192 Delile, M. 334 De Luc, M. on the penpertics of vae pour, 169 Distilled waters, how to preserve, 379 Donkin, Mr. B. Description of his in- strument for ascertaining the veloci- ties of machinery, 121 Drugs of the East Indies, 276 Dry-rot in timber, 287 Du Hamel, M. 371 E. Fast Indies, directions for sailing to, and from, 159 Echoes, see Acoustics. Edgeworth, R. L. Esq. his description of a spire of a new construction, 241 Electricity of the clouds, 59, 62 Ellis, Mr. his method of packing plants and trees, for exportation, 340 Etioiation of vegetables and plants, 144 Evaporation, theory of, 48 Ewbank, Mr. G. 27 F. Farey, J. Esq. on the nature of those meteors commonly called shooting stars, 285 Farquharson, Mr. J. J. 387 Fever bark of the East Indies, 276 Fibrin, constituent principles of, 73 -Figuier, M. his analysis of the water of Ussat, 79 Filings of irgn, machine for separating, _ from those of other metals, 127 Fluids, passage of, in animal bodies, 173, 299 Fontana, Abbé, 324—His experiments with the poisonoys upas of Jaya, 331 Fontaine, M. architect of the Louvre, — Ti. Forces, repulsive, that act on light, 161 Forcing houses among the Romans, 147 s Forster, Thomas, Esq. his account of the thunder-storms on the 19th Au- gust, 62—Answer to his inquiry re- lative to the migration of swallows», 218—On the peculiar appearance of those meteors commonly called shoot- ing stars, 131—-See also 285 Fourcroy, M. 298, 351 Fourcroy and Vauquelin, Messrs. their ere of human bones, 256—Gn amer, 356 ? Franklin, ‘Dr. 103 Fruits cultivated by the Romans, now in our gardens, 151 old English, list of, 153 Furnaces, iron, silex sublimed in, 74 G: Gall, animal, preparation of, in a con- centrated state, 154 Gallaud, M. 217 Galvanisin, 157, 183 | Gas, acid, a new, 28 Gas, oximuriatic, disquisition on, 28, 157—-On the conversion of carbonic oxide into carbonic acid, by it, 226 Gasses, specific heat of, prize caer on, 78 : Gatcombe, Mr. 175, 296 Gaub, extract of, 280 ; Gay Cushs M. 267—His experiments on ‘the velocity of sound, 1035—On the precipitation of silver, by copper, . 318 ae Gay-Lussac andThenard, Messrs. 227, 234——-On the analysis of vegetable and animal substances, 66 Gehlen, M, 268 5 Gerboin and Hecht, Professors, their analysis of the water of: Niederbrunn 80 E : Gilbert, Messrs, 269 , Good, T. M. Esq. 239 Gong, Chinese, analysis of, 307 Gold, native alloy of, 137——Prepara- tions of, for medical uses, 248 Gough, Mr. J. on the place of a sound produced by a musical string, 321 Cor Grape IN D EX. Grape-houses of the Romans, 149 Gratiola officinalis, analysis of, 365 Growth of roots, causes by which it is influenced, 370 Grignon, M. 74 " Grimstone, H. esq. 76 Guyton-Morveau, M. 10--On the art . of coating metals with platina, 292 Gum, yellow, from Botany Bay, ana- lysis of, 310 Gunnery, problems in, 81 H. Hall, M. Esq, on, chemical aftreotit, 193 » Haloes, how eemneas 43 Harcourt, Earl, 273 Hiarrison, Dr. R.27 Hassell, Mr. J. his improvement in the aquatinta process, 220 Hassenfratz, M. his experiments on the transmission of sound, 103 \Batchett, Mr, 293—His' artificial tan- ening 851 © ee oy Haiiy, M. on zeolite, 138—His descrip- tion of several new varieties of car- _cbonated lime, 189 Haussman, M. 351 ‘Heat, radiant, experiments on, 78, 192 Heat, specific, of gasses, 78 Hecht, Professor, see Gerboin. Hedge hyssop, analysis of, 865 ‘Heinekin, M. his experiments on the decomposition of carbonate of potash, 157 Henry, Dr, 262 Hericourt de Thury, M. 190 Hippograph, an invention for conveying intelligence, 126 . : Home, E. Esq. 299—His experiments to prove that fluids pass directly from the stomach to the circulation of the blood, and thence into the cells of the spleen, the gall-bladder, and uri- nary bladder, without going through the thoracic duct, 173 Heoker, Mr. 77 Horsburg, J. Esq. his directions for sail- ing to and from the East Indies, &e. 159 " | Horticulture, 147, 202, 204 Hospitals, London, lectures at, 78, 160. Hothouses, when introduced irito Eng- land, 149 Howard, Luke, Esq. on the riatural his. tory of the clouds, 35—See Meteora- logical Journal. ; H. T. B. on a modé ef conveying in- telligence from a reconnoitring party, 126 f Humboldt, M. Von, 270, 288 Hume, Mr. on the production of 3 colour from barytes, 34 Hurra, correction of a, mistake respect< ing, 279 Hutton, Dr. C. 134, 240 I. Ikbetson, Mrs. A. on the hairs of plants, 1--On the mechanical powers in the leaf. stalks, 179 Imaginary quantities, algorithm of, 209 Indigo yielded from some newly’ dis« covered plants, 278——How affected by nitric acid, 351 ' Intelligence, mode of conveying, 126 Tron, cast, examination of a white sub- stance, found in the cavities of, 74 Iron filings, machine for separating from extraneous matters, 127 Tron spire, on a new construction, RAL Juck, My. 381 K. Kemp, Mr. G. his method of pre- paring a beautiful and permanent - white for water-colours, 33 . Kennedy, Dr. 134 . Rctont Kirwan, Mr. 261° ome Klaproth, M. his examination of the zeolite, 183—-On the analysis of a Chinese ‘gong-gong, 307 « ¥ ~~ houses” og. cic h A. Esq. 77—On the ee. — Lancaster, Mr. J. 273 IND houses of the ancient Romans, 147— . Defcient in his description of the leaf- * stalk, 179—-On potatoes, 204——On the causes which influence the di- rection of the growth of roots, 370 L.' Land, waste, improved, 275 Laplace, M. ‘his experiments on sound produced in vapour, 171 , ‘Lasalle, Dr. 583 Lavoisier, M. 385 ~~ Laugier,’ M. his chemical examination of the yellow resin of the xanthorrea hastilis, and of the résindus cement employed by the savages of New Holland to fix the stone of their . hatchets, 310 Leaf-stalk of plants, 179 Le Breton, M. 10 Lectures, medical and chirurgical, in. London, 78, 160—In Bristol, 72—— At the’ Scientific Institution, 250— At the Surrey Instithtion, 239 Leghorn hats, substitute for, 275 _ Leslie, Professor, 193 Lester, Mr. W. his description of a ma- chine for washing potatoes and ot her esculent roots, for feeding cattle, “356 Lever, fundamental property of the, Pic Ue ae Lewis, 294 Leybourn, Mr. T. 240. LHuilier, M. 217 Light, reflected, a newly discovered: property of, 95—Repulsive forces that act on it, 161—Phcnomena of, 192—Inclination of plants towards, 144 Lime, new varieties of the carbonate of, 189 Lydiatt, Mr. E. 239 M. Machine for washing roots, 336 Machinery, ‘instrument for ascertaining the velocities of, 121 Malus, M. en a property of reflected EX. Jight, 95-—On a. property of, the re- pulsive forces that act on light, 161 His inquiries’ respecting polarised light, 192 Manufactures, lectures on, 240 Marcet, Dr. his experiments on zeolite, ' 135 ; Marshall, Mr. G. his new method of” _ constructing sash-windows, so as to be cleaned or repaired without the necessity of any person going on the outside of the house, 129 Martin, M. his experiments on the transmission of sound, 107 Martins and srallonra migration. of, 218 ‘Warteee) M. his process for preparing pure phosphoric acid, 383 i Mathematical questions in ‘* the Lady’s Diary,” 240 Mathematicus on a remarkable analy ti- cal anomaly, 209°” ’ Maynard, Mr. 27 ' Mead, Dr. 299 Metallic filings, machine for separating, 127 Metals coated with platina, 292 "Meteor of May, 1811, account of, 216, 218 _Meteoric stones, which fell in the year., 1810, 158 Meteorological Journal, for July and August, 64—For August and Sep- tember, 142—For September and October, -256—For October and No- vember, 308 of x Meteors, called shooting stars, observa- tions on the peculiar appearances of, 131, 285 Migration of swallows, Sine Mineral water, see Water. - Minium, native, addition to the account — of, ina former volume, 137 Moncan, M. 312 Money, Mr, 175 Mons, M. Von, his distinction of rain, 63 : Moore, W. Esq, on the destruction of ie! an a INDEX. ~an enemy’s fleet at sea, by artillery, 81—On the motion of rockets, 93 Moretti, M. on an acid obtained from the distillation of indigo with nitric acid, 352, 364 Mucus, experiments on, with a view to distinguish it from pus, 25, 113 Munn, Mr. 221 Murray, Mr. his experiments on the * cdecomposition of water, 187—On chemical attraction, 193, 199==Reply to his observations on gximuriatic “gas, 28——His answer, and on the con- version of carbonic oxide into Car-_ bonie acid, by that gas, 226 # Musical lectures in Londoa, 239 Musical sound, place of, S21 Myrobalans, black, of India, 278 Ni Nauticus on the causes of the decay of the timber in ships, and. the means / of preventing it, 287 New Holand,. resinous cement used by the natives, analytically examined, $10 t Niederbrunn, analysis of the water of, 80 Nitric acid, see Acid. Northampton, lord, 338 Beye ie Oil of almonds, essential, experiments on, 500, 324—Results, 535 Olive oil, constituent principles of, 72, Oxalic acid, see Acid. Ox-gall, method of preparing for painters, 154 e Oxide, carbonic, converted into care bonic acid, 226 Oximuriatic gas, see Gas F \ P. Packing plants and trees for exporta- tion, 339 Palladium discovered in a native alloy of gold, 137 Parkinson, Mr. 240 | Pearson, Dr. G. on the properties of various kinds of pus, 17, 113 Peron, M. 310 Philosophical lectures in London, 239 Phosphate, acid, of potash, 258 Phosphoric acid, see Acid. Pictef, Professor, his account of the ap- pearance of a luminous meteor, in” May, 1811, 216... Plait, an improved, for straw hats, 273 Plants, hairs of, 1—-Inclination ofthe stems of, towards the /light, 144— Mechanism and powers of leaf stalks, 179—Mode of packing for exporta- tion, 339 Platina used for coating metals, 292 Poisons, vegetable, their action, 295, © 324 Poor, plan for meliorating the con- dition of the, 273 Pontin, Dr 261. Potash, solution_of carbonate of, de- composed by galvanism, 157—Acid phosphate of, 228 _ Potatoes, culture of, 204——Machine for . washing, 336 Poushkin, Count, 293 Precipitation of silver by copper, 318 Proust, M. 155, 351, S81leeHis amal-’ gam, 293 Provost, Professor, on the meteor of the 15th of May,, 1811, 218 Priestley, Dr. 380 Pus, observations and experiments on, T7113. Q. Quantities, imaginary, algorithm of, 209... Quin, E. Esq. 239 R. Rachet, M. 380 Radiant heat, phenomena of, 192 , Rain, distinction of, into that of de- composition, and that of recompositicn, 63 ' ‘Rawlisn, INDEX. Rawlins, Mr. R. 296 Rees, Dr. 35 Resin, common, analysis of, 72--Yellow, of New Holland, analysis of, $10 Reith, Mr. A. 541 Ritter’s experiment on the decomposi- tion of water, 184 Richter, M. 260 Roberts, Mr, S. his description of an ap- paratus used at Sheffield for cleansing chimneys, 349 Rockets, motion of, 93 Romans, their forcing-houses, 147—< Fruits cultivated by, 151 Rondelet, M. 13 Roots, causes which influence. the di- rection of the growth of,,370—Ma- chine for washing, 336 Ross, Mr. J. D. 261, 581—His machine for separating iron filings from their mixture with other metals, 127 Roxburgh, Dr. on various drugs of the EastIndies, 276 S. Sailing, directions for, 159 Salisbury, Mr. W. his method of pack- ing plants and trees intended for exe portation, so as to preserve their vege- tative powers for many months, 339 Salts, neutral, roma s on the analysis _ of, 260 Sash-windows on a new construction, 129 Saussure, M. on the properties of va- pour, 169 Scientific Institution, lectures at, 239 Scientific news, 78, 157, 239 Sennebier, M. 380 Sewell, Mr. 179 Ships; means of preserving from decay, 287 Shooting stars, 131, 285 _ Silex sublimed in iron-works, 74 y Silver precipitated by copper, 318 at Simpson, Rev. J. his account of the Burrknot apple, 76 Sinclair, Sir J. 208 Singer, Mr. G, 239 Smithson, J. Esq. on the composition of zeolite, 183—-Addition to his ac- count of native minium, printed ina former volume, 137 Sdund, transmission of, through solids and air, 103—Production of in va- pour, 169—Produced by a musical string, place of, $21 Spire on a new construction, 241 Spring-Grove codling, description of, 7 Stansfeld, Mr. 113 Stars, shooting, peculiar appearances of, 2. 131, 285 ‘hie Stems of plants, their inclination te- wards the light, 144 Stodart, Mr. 294 Stone, composition for defending against the injuries of the atmosphere, 11 Stones, meteoric, description of those which fell last year in France, a Strauss, M. 293 Straw hats, British, 273 Struve, Professor, on the composition of zeolite, 136 Stomach, direct communication. bes tween it and the blood, 173, 299 Stucco for preservirig stone, 10 Sugar, crystallised, analysis of, 72 Sulphuric acid, see Acid Sun, illumination of the, 192 Surrey Institution, lectures at, 239 Swallows, migration of, 213 Sylvester,.Mr. communication from, Tee lative to the migration of swallows, - 213 A Thay Tachometer,: an instrument-~for ascers taining the velocities of machinery, described, 121 : Tannin, artificial, 351 Taylor, Dr. C. 276 ‘Thenard, M, 224—-See Gay-Lussac Thomson, Captain, extract from his log- book, 213 : ‘ A Thomsen, Thomson, Dr. 193, 268 Thompson, Mr, A. T. 343° Thunder-storms on the 19th SRREN=K, 62 Tilloch, Mr. 35 Timber, causes and prevention of de- cay of, 287 Tobacco, empyreumatic oil of, experi- ments with, 302, 535 Traill, Dr. on the pate of “pel 213 Trees, mode of packing for le $39 ‘ , Trembley, M. 217 Trommsdorff, M. 295 Vv. Vapour, natural history of, 48—Produc- tion and transmission of sound in, 169 Vauguelin, M. 10, 156, 293, 851—His chemical examination of a white fila- mentous substance, found in the ca- vities of the cast iron that adheres to the sides’of high furnaces, 74—His examination of zeolite, 133—On the acid phosphate of potash, 238-—His experiments on some preparations of gold, 248—-On human bones, 256— On mixtures of sulphuric acid and water, 319-—-On amer, 356—On the analysis of hedge hyssop, 365. ~Vegetable poisons, 295, 324 Vegetable substances, dessiccation of, aga Vegetables, see Plants Vegetation, its action on water, 72 Vergue, M. his analysis of the mineral water of St. Felix de Bagnére, 79 Vibrations of sound, 321—See Sound Vitalis, M, 239—On the amalgam of mercury and silver, called arbor diane, INDEX. Vogel, M. 879 Volatile acid, see Acid Pts, Upas of Java, experiments with, 827 Ussat, mineral waters of, analysed, 79 Ww. Washing roots, machine for, 336 Waste land rendered valuable, 273 Water, how affected by vegetation, 72 —Decomposed by galvanism, 183 Water, mineral, of Bagnére, analysis of, . 72m—OF Ussat, 79-—Of Niederbrunn; 80 if Water-colours, imprevement in, 33 Waters, distilled, mode of preserving, 379 Weather, indications of changes of, from observation of the clouds, 35——= 62 hig : Welther, M. on amer, 351, 364 W.H, B. inquiry from, relative to the economy of ants, 10 White, 2 beautiful and permanent, for water-colours, 33 Windows, sashes of, constructed so as to be capable of being cleaned within- side of the house, 129 | Woodhood, Mr. J. 341 Woorara, experiments with, to ascertain the action of its poison, 324, S92—— Results, 335 Be e Xanthorreea, of New Holland, degcrip= tion of, 310 Z. Zeno, answer to, 93 Zeolite, composition of, 188, 496 ERRATA. 74 Note, for xxvii, p. 192, read lxxiii, p. sixiep 127 line 5 for H. J. B. read HT. T.B. < 156 Note, for lxii, read Ixxii. 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