ites + betes siesta sites 7 i z i apie eer begs tae i peste gsergs tests eet 5 Pirie pattishee payeenits iat Seteite rostesege tet sat teri ietenshentned ; } i +e) peseearsrue ae bed Hk t > : : “ satete, ; ; : 3 . sett: is eH i thi has babe te tt ; ar ! epee Hatton heka Saomebal sities petals Stat uate : itt i asteaetetae ae Vetoes eee te dy paghebstises Stel Hy t : i aa be oreeae dy i Sigtinitt auib | te ai + + posers | p : ° they : “i : ie Hath 108 ern <2 t = } i + Ht i f at i : i Het ne A oe — ' A JOURNAL NATURAL PHILOSOPHY, CHEMISTRY, AND Sab AR ols. VOL. XXIV. - Sllustraten with Engravings. 3 BY WILLIAM NICHOLSON. LONDON: PRINTED BY W. STRATFORD, CROWN COURT, TEMPLE BAR; FOR W. NICHOLSON, CHARLOTTE STREET, BLOOMSBURY; AND SOLD BY J: STRATFORD, No. 112, Hoxzorn Hit, 1809. PREFACE. SHE Authors of Original Papers and Communications in the present Volume are Dr. John Bostock ; James Burney, Esq.; j.B.; E.F°G.H.; J. B. van Mons; Mrs. Agnes. tbbetson ; W. Saint, Esq,; Mr. B. Cook; Mr. J. Acton; Mr. R. B. Bate; James Staveley, Esq.; Sir George Cayley, Bart.; Mr. G. J. Singer; R. Z. A.;-W.N.; M. le Comte de Bournon, I. R. and - L. S.; Mr. Robert Lyall; Mr. P. Barlow; J. F.; Mr. Robert * Bancks. Be Of Foreign Works, Prof. F. R. Curaudau; M. Gay-Lussae ; M. Thenard; M. Alex. Brongniart ; Prof. Lenormand; M. Hasgen- fratz; M. Haiiy ; M. Rampasse; Prof. Picot; M. L. Cordier; M. Descotils; P. A. Steinacher; M. Bouillon-Lagrange; M. Vogel ; M. Fourcroy ; M. Vauquelin; M. Cuvier; M. Chaptal; M. Ber- thollet, Jun. ; M. Klaproth ; M. Bucholz; M. Berthier. And of British Memoirs abridged or extracted, Humphry Davy, Esq. Sec. R. S. F. R. S. Ed. and M. R. 1, A.; Capt. W. Bolton; Capt. H.L. Ball ; Mr. John Tad ; Mr. W, Barlow ; J. G. Children, Fsq. F. R.S.; Wm. Henry, M. D. F. R. S. V.P. of the Lit. and Phil. Soc. and Physician to the Infirmary at Manchester ; Jamee Rennel, Esq. F. R. S. The Engravings consist of 1. Captain Bolton’s’ improved Jury Mast; 2. Captain H. L. Ball’s Method of Fishing an Anchor; 3. Captain Ball’s improved Anchor; 4. Mr. J. Tad’s Method of causing a Door to open over a Carpet; 5. Mr. W. Barlow’s Wrench for Screw Nuts of any Size; 7. The Sting of the Nettle, highly magnified, in its natural State, emitting its Poison, and when broken; 8. The Awn of the Indian Grass, used in Captain Kater’s Hygrometer ; 9, The Leaf and Stem of the Sensitive Plant, showing their Structure; 10. The Spiral Wire and its Case greatly magnified; 11. Luminous Meteors, seen during a Thunderstorm, by James Staveley, Esq.; 12. Diagrams to illustrate the Theory of Aerial Navigation, by Sir George Cayley, Bart.; 13. A Machine that will ascend into the Air of itself by mechanical Means; 14. A Machine with which a Man may raise himself into the Air; 15. Figures illustrating the Crystallization of Endellion, by the Count de Bournon; 16. Diagrams for a Demonstration of the Cotesian Theorem, by Mr. P: Barlow; 17. Various Delineations and Sections of Grafts and Buds, from original Drawings after Nature, by Mrs. Agnes Ibbetson ; 18. Branch of a Portugal Laurel, from which the Bark had been accidentally separated; 19. Different Structures of several Kinds of Wood. TABLE TABLE OF CONTENTS TO THIS TWENTY-FOURTH VOLUME, SEPTEMBER, 1809. Engravings of the following Subjects: 1. Captain Bolton’s improved Jury Mast 2. Captain H. L. Ball’s Method of Fishing an Anchor: 3. Captain Ball’s im- proved Anchor: 4. Mr. J.Tad’s Method of causing’a Door to open over a Carpet: 5: Mr. W. Barlow’s Wrench for Screw Nuts of any Size. I. On the Union of Tan and Jelly: by John Bostock, M. D. = 1 IL. The Bakerian Lecture. An Account of some new analytical Researches on the Nature of certain Bodies, &c. By Humphry Davy, Esq. Sec.R.S. F, R.S. Ed. and M. R. 1. A. - 7 r . - 12 III. Remarks on the Boracic Acid, addressed to the first Class of the Institute, December 19th, 1809, by F. R. Curaudau, Professor of Chemistry applicable to the Aris, and Member of several literary Societies. - 24 IV. Abstract of a Paper on the Decomposition and Properties of Fluoric Acid, — presented the Oth of January fo the Mathematical Class of the Institute, by Messrs. Gay-Lussac and ‘Thenard. - ~- . 29 V. Description of a Process, by Means of which Potash and Soda may be me- tallized without the Assistance of Iron; read before the French Institute the 18th of April, 1808; by F. R. Curaudau. - Baise - 37 VI. Observations and Experiments on the Nature of the New Properties of the Alkaline Metals; by the same - - - : 40 VII. Improved Method of Forming Jury Masts: by Captain William Bolton of the Royal Navy =. oo - > x Ad VIII. An Improvement of the Construction of Anchors, to render them more durable and safe for Ships: with an improved Mode of Fishing Anchors. By ‘Captain H. L. Ball, of the Royal Navy. - ne 46 TX. Observations on the Progress of Bodies floating in a Stream: with an Ac- count of some Experiments made in the River Thames, with a View to dis« cover a Method for ascertaining the Direction of Currents. By James Burney, — Esq. - - - - - - 4g X. New Method proposed for measuring a Ship’s Rate of Sailing. By thesame Gentleman. - - - - ie oT XI. Method of preventing Doors from dragging on Carpets, or admitting Air underneath them. By Mr.JohnTad - : - - 59 XII. Description of an improved Screw Wrench, to fit different sized Nuts, or Heads of Screws. By Mr. William Barlow. - ar m 61 XIII. On the Measurement of Heights by the Barometer. Ina Letter from a Correspondent. Uae a - - . ei XiV. On the Glauberite. By Alexander Brongniart - - 65 XV. An excellent colourless Copal Varnish. By Mr. Lenormand, late Professor of Natural Philosophy. _ - - = 3 z 67 Scientific News - - - 2 2 68 Meteorological Table - - - ba « « F 9 GONPENMTS.. | Vv OCTOBER, 1809. Engravings of the following Subjects: 1. The Sting of the Nettle, highly magni- fied, in its natural State, emitting its Poison, and when broken: 2." The Awn ” of the Indian Grass, sed in Captain Kater’s Hygrometer: 3. The Leaf and Stem of the Sensitive Plant; showing their Structure: 4.'The Spiral Wire and its Case greatly magnified, I, Farther Application of a Series to the Correction of the Height of the Ba- rometer 5 - “ : " Pat es 81 II. On the Action of the Metal of Potash on Metallic Salts and Oxides, and on | Alkaline and Earthy Salts, By Messrs, Thenard and Gay-Lussac. ~ 92 If]. The Bakerian Lecture. An Account of some new analytical Researches on the Nature of certain Bodies, &c. By Humphry Davy, Esq. Sec. R. S. F. KR. S.-Ed. and M. R.I. A. - - - - 95 JV. Extract of a Letter from Mr. J. B. van Mons, Member of the Institutes of France and Holland, to the Editor, on Atmospheric Phenomena - 106 Y. Remaining Proof of the Cause of Motion in Plants explained ; and what is called the Sleep of Plants shown to be Relaxation only. By Mrs. Agnes Ibbetson. - ae - “ - 114- VI. A curious Property of Single Repetends. Ina Letter from W. Saint, Esq. 124 VII. On the Use of Iron for Stairs, and instead of the Timbers of Houses, as a Security against Fire. Ina Letter from Mr. Benjamin Cook. - 126 VU. On Respiration. By Mr. J. Acton. Ina Letter from the Author 130 TX. On the Camera Lucida. In a Letter from Mr. R. B. Bate - 146 X. Account of some Experiments performed with a View to ascertain the most advantageous Method of constructing a Voltaic Apparatus, for tbe Purposes ef Chemical Research. By John George Children, Esq. F. R. S. 150 KI. Report of a Memoir of Mr. Hassenfratz respecting the Alterations that the Light of the Sun undergoes in traversing the Atmosphere. By Mr. Hauy. 155 Scientific News s . - i sg 158 - Meteorological Table = - » = ss = Zi 160 - + 3 NOVEMBER, vi GON TEN fF 8: NOVEMBER, 1809. Engravings of the following Subjects: 1. Luminous Meteors, seen during a Thunder Storm, by James Staveley, Esq: 2. Diagrams to illustrate the Theory of Aerial Navigation, by Sir George Cayley, Bart.:-3. A Machine that will ascend into the Air of itself by Mechanical Means: 4. A Machine with which a Man may raise himself into the Air. 1, Account of some luminous Meteors seen during a Thunderstorm.’ In a Letters from James Staveley, Esq. - - . . 161 Hi. On Aerial Navigation. By Sir George Cayley, Bart. - : 164 HII. On Electro-Chemical Experiments. By Mr. G. J. Singer - 174 IV. Extract of a Letter from Mr. J. B. Van Mons to Mr. Sue, on different Subjects relating to Galvanism and Electricity. - ae “179 V. Description of the Process employed to ascertain the Existenceof Alumine in Meteoric Stones, by B. G. Sage, Member of the French Institute, Founder and Director of the First School of Mines i. é 190 : } VI. Letter from Mr. Rampasse, formerly Officer inthe Corsican Light Infantry, to Mr. Cuvier, on a Calcareous Breccia containing fossile Bones found in - Corsica. = 3 oraite = = = 193 VII. Extract of a Letter from Professor Picot, of Geneva, to the Editors of the Bibliotheque Britannique, on Comets. - - 2 197. VIII. On the Influence the Shape of a Still has on the Quality of the Product of Distillation: by Mr. Curaudau, Member of the Pharmaceutical and several other Societies. * - = - - 201 1X. On Vegetable Astringents. By John Bostock, M.D. Communicated by the Author. - - - . - 204 X. Question on the Preparation of Cork for modelling.‘ In a Letter from a Correspondent. pug - > f - 222 XI. On the Dusodile, a New Species of Mineral; by Mr. L. Cordier 223 XIU. Memoir on the Triple Sulphuret of Lead, Cupper, and Antimony, or Endellion. By M. le Comte de Bournon, F. R. and L. S. - 225, XIII. On Detonating Silver. By Mr. Descotils. - - 237 XIV. Process for making a Fine Lake. - ° a 238 XV. On the Blue Wolfsbane, by Philip Antony Steinacher. peo 238 Scientific News. > - - = . 239 Meteorological Table. ° , = > - . 240 - DECEMBER. CONTENTS. vil DECEMBER, 1809. Engravings of the following Subjects, (In Two Quarto Plates :) 1. Figures illustrating the Crystallization of Endellion, by the Count de Bournon. 2, Diagrams fora Demonstration of thé Coiesian ‘Theorem; by Mr. P. Barlow. I. On Vegetable Astringents. By John Bostock, M.D. Communicated by the Author - - - 241 if. Memoir on the triple Sulphuret of Lead, Copper, and Antimony, or En- dellion. By M. le Comte de Bournon, F. R. & L.S. - 254 ill. Of the Irritability of Vegetables. By Mr. Robert Lyall, Surgeon. Read at the Literary and Philosophical Society at Manchester, Oct. the 6th, 4809. Communicated by the Author. - - , 261 TV. Demonstration of the Cotesian Theorem, by Mr. P. Barlow 278 V. On the Influence of Electricity on Flame: by Mr. Leopold Vaeca, Colonel of the 23d Regiment of Light Infantry. - - 283 VI. Of the Action of Phosphorus and oxigenized muriatic acid Gas on Alkalis: by Messrs. Bouillon-Lagrange and Vogel. - - ~ 985 VII. Onthe Chemical Analysis of the Onion. By Messrs Fourctoy’and ‘Vau- quelin. - - E: z - = 290 * VIII. Abridgment of a Paper on the Species of Carnivorous Animals, the Bones of which are found mixed with those of Bears in Caverns in Germany and Hungary. By Mr.-Cuvier. - - - : 295 IX. Account of seme.Colours for Painting, found at Pompeii; by Mr. Cliaptal. Cominunicated to the First Class of the Institute, March the 6th, -1809. 302 X. Remarks on the Introduction of Air into the Blood through the Lungs, in “Answer to Mr. Acton. Ina Letter from a Correspondent. - 307 XI. Letter from Mr. Robert Bancks concerning the Meteorological Journal. 308 Scientific News. - - - = - 309 Meteorological Journal. ms 7d Eee: - 320 SUPPLEMENT. Viii CONTENTS, SUPPLEMENT TO VOL. XXIV. Engravings of the following Objects: 1. Various Delineations and Sections of Grafts and Buds; from original Drawings after Nature, by Mrs. Agnes Ibbetson, 2. branch of a Portugal Laurel, from which the Bark had been accidentally separated. 3. Different Structures of several Kinds of Wood. I. Memoir on the Triple Sulphuret of Lead, Copper, and Antimony, or En- dellion. By M.le Comte de Bournon, F. R.and L. S. ~ 321 II. On the Effects produced by the grafting and budding of Trees, Ina Letter from Mrs. Agnes [bbetson, i : - . 337 III. On the Defects of grafting and budding. By Mrs. Agnes Ibbetson. 346 IV. Experiments on Ammonia, and an Account of a new Method of analyzing it, by Combustion with Oxigen, and other Gasses; ina Letter to Humphry Davy, Esq. Sec. R.S., &c., from William Henry, M. D.F.R. S., V. P. of the Lit. and Phil. Society, and Physician to the Infirmary at Manchester. 358 V. Observations on the Composition of Ammonia. By Mr. Berthoilet, jun. 374 VI. Analysis of the Chinese Rice-Stone, with.some Observations on the Yu. By Mr. Klaproth. - - - yo - 375 VIL. On the Effect of westerly Winds in raising the Level of the British Channel. Ina Letter to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. By James Rennel; Esq. F. R. 5. - i) ah Sk met - 379 VIII. On Dead Lime. By Mr. Bucholz. - - “t) eSB) TX. On the Muriates of Barytes and of Silver. By Berthier, Mine Engineer. 383 ERRATUM. Page. line. 278 14 for Théorie read Calcu?. A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. SEPTEMBER, 1809. ARTICLE I. On the Union of Tan and Jelly: by Joun Bostock, M. Dz To Mr. NICHOLSON, SIR, URING the course of the last spring I was engaged in Purpose of the a set of experiments, which may be considered as a conti- ocr Be nuatioa of those formerly made on the analysis of animal fluids*. My object was to enable the operator to apply the tests, which indicate the existence of the principal consti- tuents of these fluids, albumen, jelly, and mucus, so as not only to discover the qualities of the compound, but the’ quantities of its ingredients. The results of my experi- ments have been, upon the whole, unsuccessful; and I have at present chiefly to announce the failure of the different expedients, which I employed to attain my object. tt may not, however, be altogether useless, to lay my experience * See Journal, vol. IX, p, 244, Vou, XXIV. No. 106—-Serz. 1809. B before g ON THE UNION OF TAN AND JELLY. before your readers; not merely because I have it in ray power to state some few facts, that may be considered as an addition to our stock of knowledge, but still more, because I may induce some one more skilful than myself, to point out a method of accomplishing what I have hitherto at- tempted without success. i Jelly. The substance upon which I first operated, and to which — I shall principally confine my attention in the present pa- Its characters. per, is jelly; the characteristics of which are its solubility in water, its forming an insoluble compound with tan, and the property which its aqueous solution possesses of con- creting by cold, and being redissolved by the application Inquiry whe- of heat. The problem which I was anxious to solve was, ve Me Sia whether the compound of tan and jelly be uniform, so that be proportion- by saturating the gelatinous part of a solution with tan, Greaney pie. and collecting the precipitate, we may, from its weight, sent. (the quantity of tan employed being known) ascertain the amount of the jelly previously contained in the fluid. From the experiments that had been performed on the subject, Mr. Biggin’s particularly those of Mr. Biggin and Mr. Davy, I conceived, teen that this would be found to be the case. The object of Mr. Portion of tan. Biggin’s experiments was to ascertain the proportion of tan in different barks, for which purpose he formed similar in= fusions of them, and precipitated the tan from each by a solution of glue. He employed the solution of glue always of the same strength, and by collecting the precipitates, he judged of the quantity of tan that had united itself to - the glue, and thus of the proportion of it in the bark*. ‘The experiments are important, as comparing the different barks with each other, and thus ascertaining their respective value as substances to be employed in the manufacture of lea ther; but it is obvious, that, unless the compound of tan and glue be uniform, they do not show the absolute quan- Mr. Davy tity of tan in any given weight of bark. Mr. Davy, in his shows the pre- experiments on astringent substances, has pointed out, with cipitate Is pro- © ; es portionate to his aceustomed sagacity, the different effects that are pro- the strength of Guced in the uniou of solutions of tan and jelly, according the solution. ‘. Ae ‘ 3 to their degree of concentration; and has proved, that in * Phil, Trans, 1799, p. 260. ‘ proportion s ‘ON THE UNION OF TAN AND JELLY. $ ‘proportion to the strength of the solution, either of jelly or of tan, will be the weight of the precipitate cbtained*. ‘It would appear, that, when the solutions are much diluted, the attraction of both the jelly and the tan for the water, “to a certain extent, counteracts their attraction to each other, and thus prevents a portion of them from being re- moved from the fluid. Mr. Davy, however, as well as Mr. Both suppose - Biggin, evidently seems to have conceived, that the sub- ne : : : € 1iOTMA ‘stance which was precipitated in all instances possessed the compound, “game properties, and consisted of a uniform compound of the two ingredients. This opinion is the very foundation of- the method which he employed in his analyses, and is di- -rectly asserted in’ different parts of his papers f. With this impression it was, that I entered upon a set of The cea ae “experiments, which may be considered as the converse of pene Ee $ those of Mr. Biggin and Mr. Davy. The object of these theirs. chemists was, by the agency of jelly, to remove all the tan ‘from a vegetable infusion, and to estimate its quantity from the weight of the precipitate; while mine was, by means of ‘tan, to ascertain the quantity of jelly that was contained in ‘any animal fluid. In pursuing this investigation, the first A uniform re ‘point was to determine upon the most proper substance to 28ent requisite employ as the reagent; for as it is difficult, if not absolutely impossible, to procure tan in a’ state of perfect purity, it became necessary to discover some vegetable infusion, which ‘should always possess similar properties, aud in which the quantity of tan should be known, without having recourse to any long calculation. My attention was naturally, in -the first instance, directed to galls; and I expected, that Galls, -by employing equal weights, infusing them in equal quan- tities of water, and for an equal length of time, fluids -would have been formed always containing equal quantities _of tan. But upon making repeated trials, I find that this ~ -is not the case; and it would appear from all the experience Not uniformia J have had upon the subject, that'two parcels of galls will ‘nature, scarcely ever be procured, which will precisely agree in their * Phil. Trans. 1803. + Phil. Trans, 1803, Nichelson’s Journal, vol. V, p, 259, 269, & alibi, : Ba : hature. or homogene- ous in their Structure. An extract of them does not answer, ON THE UNION OF TAN AND JELLY. -nature. If finely powdered galls be infused for two hours in 8 times their weight of boiling water, an infusion is formed, which is generally transparent, of a deep brown colour, and which contains about one tenth of its weight of solid matter. But although this is the usual result of the process, it is by no means constantly so. Frequently the infusion will be thick and muddy, will not be rendered clear by being passed through the filter, nor will it become so after standing at rest for several days; its colour also va- ties considerably, the brown tinge existing in different shades of intensity, and occasionally being exchanged for a bottle green. The quantity of solid matter contained in the fluid is seldom precisely the same in any two trials; al- though it is generally about one tenth, yet I have occasion- ally found it no more than one fourteenth. Although it may appear at first view somewhat singular, that such dif- ferent effects should be produced by the same substance; yet, when we attend to the visible difference, that, exists in gall nuts, we shall easily conceive how these variations may take place. The structure of galls appears to have been little attended to, and they have generally been spoken of as homogeneous bodies, before the accurate description of their several parts, that is given by the Mr. Aikins in their Jate valuable publication *. As it appeared impossible to employ a recent infusion of galls for, the standard fluid, I thought of evaporating the infusion, and making use of a solution of the dried resi- duum. But I found, that this residuum, although formed from a perfectly transparent infusion, is not capable of be- ing completely redissolved, owing to some change that has been effected,.on one or more of its constituents, probably the extract, by which it becomes no- longer soluble in water. -This circumstance forms an insuperable objection to the employment of the dried residuum as a standard, because the quantity of matter, depending upon the variable pro- portion of the soluble and insoluble part, or of the tan and extract, will scarcely ever be found the same in any two specimens upon which we may operate. — * Aikiis’ Chem. Dict. Art, Gall nut. The ON THE UNION OF TAN AND JELLY) 5) - "The infusion of galls, however prepared, seemed inade-’Mr. Hatchett’s quate to the purpose of affording an accurate test for jelly, apicinl katy I thought therefore of employing the artificial tan disco- vered by Mr. Hatchett, because, being a substance formed by a specific chemical action, it may be supposed always fo possess the same chemical properties. It was accordingly prepared by digesting powdered charcoal in nitric acid, and the result coincided entirely with the description of Mr. Hatchett; it was readily dissolved both in water and alco- hol, it précipitated jelly from its solution, and also the nitro- muriate of gold, the muriate of tin, the superacetate of lead, and the oxisulphate of iron. All these properties show its strong resemblance to the infusions obtained from astringent vegetables. I was however disappointed in not finding it to answer the purpose that I had in view. Al- though the artificial tan very readily afforded a precipitate formed an im- from a gelatinous solution, yet the jelly seemed to be only os Piesie t imperfectly thrown down, the fluid remained muddy after the operation, and the precipitated matter could not be com~ pletely separated from it. This circumstance I found to take place with different portions of the artificial tan, which were each of them prepared with every attention to Mr. Hatchett’s directions; and, I conceive, depends upon a owing to the quantity of undecomposed acid, which remains attached to Hah - wa the tan, and which cannot be entirely removed from it. acid. This excess of acid was always found in my expériments,’ and must probably have existed in Mr. Hatchett’s préepara= tions, for he points out their property of reddening litmus as one that is characteristic of them*. To whatever cause’ we may ascribe it, it seemed to be a sufficient objection to the use of this substance as a test for jelly. Catechu was next tried, but without any better success.,Catechu does Independent of the difference which exists between dif- 2° 4nswer. ferent specimens of this substance, which is considerably greater than what is found in the infusion of galls, I have never met with any catechu which is entirely soluble in wa- ter, In the different trials that I made to procure standard * Phil. Trans, for 1805, p. 215, solutions Spentaneous gecom position of its infusions. - Its precipitate ike that of ar- tificial tan. ¥xtract of rha- tany. Preparation of the jelly. e ON THE UNION OF TAN AND JELLY. solutions of catechu, a portion appeared to be only sus- pended in the fluid, so that it remained muddy, and neither, became transparent by standing, ner was the insoluble part removed by passing throngh a filter. . The infusions of ea techu likewise became aitered by exposure to the atmo- sphere more rapidly .ua. those of galls, a considerable portion of the substance that had been dissolved being gradually deposited. This deposition goes on so rapidly, as to exhibit an appearance something similar to the saline vegetation of certain salts, the catechu creeping up along the sides of the glass to some distance above the surface of the fluid. I was not able to detect any dif- ference between the part of the catechu which is retained in solution, and that which is deposited, except that the last. was of a lighter colour, aud was less soluble in water; they both produced precipitates with jelly and the muriate of tin. ‘The precipitate which the catechu forms with jelly, like that produced by the artificial tan, does not in general form a compact or solid mass, but makes the fluid turbid without entirely subsiding from it, nor is it rendered trans- parent by being passed through a filter. This cireumstance, as well as its imperfect solubility, renders catechu inappli- cable as a test for jelly. The next substance that I tried was the extract of rha- tany, a preparation said to be brought from the Portuguese settlements in South America; and, in consequence of its tonic quality, lately proposed as an addition to the materia medica. It contams a large proportion of tan; from the experiments that I have made upon it, larger than any other astringent extract with which we are acquainted; it appears to be more homogeneous in its consistence, it is completely soluble in water, and seems to remove jelly from its solution more readily than the other substances which I had tried. These properties pointed it out as the most nearly approaching to what I was in search of. Before giving an account of the result of the union of tan and jelly, it will be necessary to make some remarks upon the preparations of this latter substance. It has been stated apon the highest authority, that of Mr. Hatchett and Mr. Davy, A ON THE UNION OF TAN AND JELLY. eS: Davy*, that isinglass consists nearly of pure jelly. 1 ama Isinglass varia~ . not disposed to question the general fact ; but I may men- 2>!¢ m the tion, as the result of my own experience, that this is not al- sc ete la ways the case; and that, even in @ majority of instances, the isinglass that is procured from the fhops wiil be found ' to contain a consiijerable proportion of insoluble matter, which I conceive to be of the nature of coagulated albumen. The proportion of the matter soluble in water, which I re- gard as pure jelly, and of the insoluble part, is very various. In one instance, where the isinglass was boiled with twenty times its weight of water, the jelly that was formed, instead of holding in solution 5 per cent of solid matter, was found to contain not more than 3°8, and although the addition of more water carried off some of the substance which had been left at the first boiling, still more than 75 of the isinglass was put this may left, apparentiy incapable of farther solution. This diffi- be separated. culty is obviated by boiling isinglass in water, pouring off . the jelly, and evaporating it to dryness; by which means a substance is procured, that is always ready for experiments. - But as this operation is attended with some trouble, I wish to substitute for ita solution of glue, according to the pro- cess. employed by Mr. Biggin. Glue is entirely soluble in water, and therefore does not present the objectivn that at- taches to isinglass, yet there are some circumstances, which seem to render glue less eligible for the purpose of experi- ments. From the mode in which glue is prepared it might lds Montages be supposed, that it would contain a quantity of albuminous albumen, matter; and I was confirmed in this opinion by finding, that a solution of it has a precipitate formed in it by being boiled with the oximuriate of mercuryt.. The quantity of muriate muriate of of soda that exists in glue must be considered as an im- soda, purity, which may have some effect upon. the combination ef jelly and tan. A more important circumstance, however, and one which appears to have been disregarded by those who have employed glue as a tvst for tan is, that, as it is usually prepared, it coutains a considerable proportion of * Hatchett, Phil. Trans. 1800; Davy, Phi!. Trans, 1803. _ .* This circumstance had been noticed by Dr. Thomson, Chem, Vol. ; ¥, Pe 479. water. S) ON THE UNION OF TAN AND JELLY. afl much water. By permitting glue divided into small pieces to re= water, main in a heat of about 150° for 24 hours, I found that it had lost 10 per cent of its weight. And even although we might have the glue in a state of complete dryness and purity, I should doubt whether it be a proper substance to Glue differs. employ on the present occasion. Although it possesses the considerably properties which characterize jelly, yet a solution of glue from isinglasse . : 5 oe : ‘ will be found to differ from a solution of isinglass, while they both contain the same proportion of solid matter. This difference is the most remarkable with respect -to their power of concretion. A.solution of glue, which I found by evaporation to contain »; of its weight of solid matter, al~; though strongly adhesive, remained quite fluid when cold, whereas a similar solution of isinglass jelly would have been perfectly concrete. Glue also differs from isinglass in be- ing considerably more soluble in cold water. Glue broken into small pieces, and digested in ten times its weight. of water, at the temperature of the atmosphere, was in 48 hours entirely broken down, and so far dissolved, that the upper part of the fluid strongly precipitated the infusion of galls. Pieces of isinglass treated in the same manner were softened, and had their bulk: increased, but the fluid was scarcely affected by tan. These circumstances led me to regard glue as difierent from isinglass jelly, and as possess- ing in an inferior degree the characteristic properties of , jelly. Experiments From these different circumstances I determined to em- mec abd ploy the soluble parts of isinglass, and the extract of rhata~ of isinglassand ny, in my future experiments on the combination of tan and extract of : dg ae rhatany. jelly. But before I enter upon a description of the results, that were obtained by the union of these substances, I think it necessary to point out the difficulty, which occurs in the prosecution of these experiments, particularly in the col« lecting of the precipitate, ‘When.the tan and jelly are not - Difficulty of employed in a state of considerabie concentration, and when collecting the 3 4 : precipitate, they are not added together in that proportion, which seems . to form the most perfect compound, the precipitate sepa- rates slowly from the fluid, or sometimes remains perma- nently suspended ; and when it is passed through a filter, it adheres to the paper so strongly, that it cannot be com- . a pletely ON THE UNION OF TAN AND JELLY. 9° pletely removed from it. Nor could I obviate this objection by weighing the paper before and after the fluid had pass< ed through it, and thus calculating the weight of the preci- pitate. I found that in this case the paper acquired weight, not only from the precipitated matter, but likewise from what was still retamed in solution. When an infusion of rhatany in the proportion of 1 to 10 was passed through a. paper filter, the filter when dried was found to have acquir- ed an addition of not less than +4 of its former weight. A solution of jelly of the same strength passed with difficulty through the paper, and a large part was detained by it. Hence it follows, that, except in those cases where the fluids neutralize each other, so as to precipitate all their contents, we cannot ascertain the amount of the precipitate from the weight gained by the filter. What has been said will be sufficient to fhow, that perfect accuracy cannot be attained in these processes, even were the sahara of tan and jelly in all cases a uniform substance. I was soon however convinced, that the substance formed The precipi- by the union of tan and jelly varies considerably according sud Sse dk to the circumstances under which it is formed, particularly ; according to the proportion in which the two ingredients are presented to each other. ‘Without entering into a detail of the numerous trials, that I made upon this subject, I fhall think it sufficient to give an account of one expe- riment, that may serve as a specimen of the rest. I must here remark, that, although my experiments agreed suffi- ciently to satisfy me respecting the nature of the conclusions that were to be deduced from them, yet I never performed two, in which the results exactly coincided. Three equal portions of the extract of rhatany were dis- solved in ten times their weight of water; and three por- tions of jelly from isinglass were procured, bearing respec- tively the proportions of 8, 4, and 2 to the” three portions of rhatany. These were also dissolved in equal quantities of water, kept soluble by heat, and added to the three portions: of rhatany. Copious precipitates were produced in ail of them, and after standing for some time, the supernatant fluids became clear. The precipitates were collected and dried by exposure to the same degree of heat. All the resi-. dual Experiment, 10 When the tan is in excess, more unites with the jelly. Differences of the precipi- tates. ON THE UNION OF TAN AND JELLY. dual fluids precipitated jelly, proving that they contained a quantity of uncombined tan; but the precipitation was. of course much less copious in the one which had received the smallest quantity of jelly. The weights of the precipitates were to each other in the ratio of 16, 9°5, and 7. Asin all the cases the whole of the jelly had entered into combina- tion, the proportion of the jelly to the tan might be esti- mated. In the first experiment, i.e. where § parts of jelly and 10 of tan were employed, the jelly and tan in the com- pound were nearly equal; where 4 parts of jelly had been added to 10 of the rhatany, the proportion in the compound was as 42 to 58; and where only 2 parts of jelly had been employed, the compound consisted of 28°5 parts of jelly to. 71°5 of rhatany. From these experiments we learn, that in proportion as the tan exists in excess more of it becomes united to the jelly ; so that if we were to attempt to esti- mate the amount of the jelly in any fluid by the weight of the compound which it forms with tan, we fhould much overrate the quantity of the jelly, Having found, that, where the solutions are employed in a state of considerable concentration, a compound is formed consisting of nearly equal weights of the two ingredients, we might conelude, that the quantity of jelly in the third experiment was in the proportion of 3°5, while in fact it was no more than as 2. The physical properties of the precipitates were’consider- ably different, so as to indicate a difference in their chemical composition. The first precipitate, which was composed of nearly equal parts of the two ingredients, was of a dark red colour, of a hard and brittle consistence, and presented a shining fracture. The second was also hard, but rather tough, and it had a brown hue; the third, containing the smallest quantity of jelly, was of a bright reddish brown, and could be pulverized between the fingers. In order to establish more clearly the difference between these precipi- tates, they were subjected to the action of such reagents as might have the power of removing from them the excess of tan, and leave the compound in its most perfect state. This seemed to be effected by boiling the third precipitate in a large quantity of water, in consequence of which process the fluid was found ta have acquired the property of copiously precipitating ON THE UNION OF TAN AND JELLY. precipitating panty: The water exhibited a reddith tinge, and was also slightly affected by the addition of iron, show- ing, that it contained a minute portion of gallic acid; no apie was, however, produced on it by the muriate of tin. The boiled precipitate now approached in its appearance to the one which was composed of equal parts of tan and jelly ; it was of a deeper colour and harder consistence. The first of these three precipitates was boiled in the same manner that this third had been, but the water was not in the least degree affected by jelly. It may appear singular, that any part of a substance, which had been precipitated from water, should be dissolved by it, but it probably depends upon the action of the greater mass of the fluid ; and the fact is confirmed by Mr. Davy’s remark, that the stronger the solutions are upon which we operate, the more complete- ly will their solid contents be separated from them. . From the foregoing observations and experimerits we may infer, that the method of detecting the quantity of jelly in any fluid, by the precipitate which it forms with tan, cannot be employed with any prospect of ‘obtaining accurate re- sults ; nor can jelly be depended upon for the purpose of obtainmg the amount of the tan in any astringent vegeta- ble infusion. In the animal analysis this deficiency will probably be found of little importance; for, notwithstand- ing the proportion of jelly which enters into our solids, and which may be readily extracted from them by water, I am inclined to believe, that nothing, which is properly entitled to the name of jelly, will be found to exist in any of our fluids. When I first began these investigations I was in- duced to form a contrary opinion, anda contrary doctrine is maintained in our most valuable systematic works. I have, however, endeavoured to prove, that jelly is not found in the blood, where it has been supposed to exist in the largest quantity*; 1 do not find any trace of it in the albumen ovi, in the saliva, in the fluid of the hydrocephalus, of spina bi- fida, or of ascites, nor in the liquor amnii. By far the largest proportion of animal matter in all these fluids is al- bumen, existing sometimes in its coagulated, and sometimes * Medico-chirurgical Trans, V. 1, p. 47. in Accurate re- sults not io be obtained in this process. No jelly in the animal fluids, but albumen, 12 and mucus? Boracic acid decomposed. Attempt to ef- fect this in quantities. ‘ DECOMPOSITION OF BORACIC ACID. in its uncoagulated state. There appears, however, to be some animal substance beside the albumen, at least in the greatest part of them, to which I have hitherto assigned the name of mucus, but whether properly or not, must be the subject of future consideration. I am, Sir, Your obedient servant, Liverpool, Aug. 3, 1809. J. BOSTOCK. a a a IS ET ER i ES EE eT Il. The Bakerian Lecture. An Account of some new analytical Researches on the Nature of certain Bodies, &c. By Humpnry Davy, Esq. Sec. R. S. F.R.S. Ed. and M. RK. I. A. (Continued from vol. XXITI, p. 334.) 6. Experiments on the Decomposition and Composition of the Boracic Acid. Iw the last Bakerian Lecture* J have given an account of an experiment, in which boracic acid appeared to be de- composed by Voltaic electricity, a dark coloured infamma- ble substance separating from it on the negative surface. In the course of the spring and summer, I made many attempts to collect quantities of this substance for minute examination. When boracic acid, moistened with water, was exposed between two surfaces of platina, acted on by the full power of the battery of five hundred, an olive- brown matter immediately began to form on the negative surface, which gradually increased in thickness, and at last appeared almost black. It was permanent in water, but. soluble with effervescence in warm nitrous acid. When_ heated to redness upon the platina it burnt slowly, and gave off white fumes, which slightly reddened moistened litmus paper; and it left a black mass, which, when examined: by * Phil. Trans, for 1808, p, 435 or Journal, vol. XX, p. 331. the DECOMPOSITION OF BORACIC ACID. 13 the magnifier, appeared vitreous at the surface, and evidently contained a fixed acid. These circumstances seemed distinctly to show the de- The combusti« composition and recomposition of the boracic acid; but as ey ue the peculiar combustible substance was’ a nonconductor of in thin films. electricity, I was never able to obtain it, except in very thin films upon the platina. It was not: possible to examine its properties minutely, or to determine its precise nature, or whether it was the pure boracic basis; I consequently en- deavoured to apply other methods of decomposition, and to find other more unequivocal evidences upon this important chemical subject. I have already laid before the Society an account of an experiment*, in which boracic acid, heated in contact with potassium in a gold tube, was converted into borate of po- tash, at the same time that a dark coloured matter, similar to that produced from the acid by electricity, was formed. About two months after this experiment had been made, namely, in the beginning of August, at a time that I was repeating the process, and examining minutely the results, I was informed, by a letter from Mr. Cadell at Paris, that Mr. Thenard was employed in the decomposition of the bo- poracie acta. racic acid by potassium, and that he had heated the two decomposed substances together in a copper tube, and had obtained bo- PY Thenard. rate of potash, and a peculiar matter concerning the nature ef whizh no details were given in the communicationt, That the same results must be obtained by the same me- thods of operating, there could be no doubt. The eviden- ces for the decomposition of the boracic acid are easily gained ; the synthetical proofs of its nature involye more complicated circumstances. I found, that, when equal weights of potassium and bo- Potassium and racic acid were heated together in a green glass tube, which boracic acid had been exhausted after having been twice filled with hie noate* 8 drogen, there was a most intense ignition before the tempe- rature was nearly raised to the red heat ; the potassium en- tered into vivid inflammation, where it was in contact with * Phil. Trans. Part Il, 1808, p. 343; or Journal, vol. XXI, p. 375. Gay Lussac ard. Thenard’s paper is given in our Jast volume, p, 260. . the 14 Large quanti- ties could not be used. Effect of naph- tha. Proper propor- tion of the two, Apparatus. Results ina - copper tube. In an iron tube. Solutions, DECOMPOSITION OF BORACIC ACID. the boracic acid. When thisacid had been heated to white- ness, before it was introduced into the tube, and powdered and made use-of while yet warm, the quantity of gas given out in the operation did not exceed twice the volume of the acid, and was hidrogen. | I could only use twelve or fourteen grains of each of the two substances in this mode of conducting the experiment ; for when larger quantities were employed, the glass tube al- ways ran into fusion from the intensity of thie heat produced during the action. When the film of naphtha had not been carefully remov- ed from the potassium, the mass appeared black through- out; but when this had been the case, the colour was ef a dark olive-brown. In several experiments, in which I used equal parts of the acid and metal, 1 found that there was alwaysa great quan- tity of the former in the residuum, and by various trials, I ascertained that twenty grains.of the potassium had their inflammability entirely destroyed by about eight grains of boracic acid. For collecting considerable portions of the matters form- ed in the process, I used metallic tubes furnished with stop- cocks, and exhausted after being filled with hidrogen. When tubes of brass or copper were employed, the heat. was only raised to a dull red; but when iron tubes were used, it was pushed to whiteness. ~In all cases the acid was decomposed, and the products were scarcely different. When the result was taken out of a tube of brass or cop- per,lit appeared as an olive coloured glass, having opaque, dull olive-brown specks diffused through it. It gave a very slight effervescence with water, and parti- ally dissotwadld in hot water, a dark olive coloured powder se parating from it. | The results from the-iron tube, which had been much more strongly heated, were dark olive in some parts, and al- most black in others.. They did not effervesce with warm water, but were rapidly acted upon by it, and the particles separated by washing were of a shade of olive, so dark as to appear almost black en white paper. , The solutions obtained, whep passed through a filter; had a faint DECOMPOSITION OF BORACIC ACID. 15 a faint olive tint, and contained subborate of potash, and potash. In cases when instead of water a weak solution of muriatic acid was used for separating the saline matter from the inflammable matter, the fluid came through the filter colourless. In describing the properties of the new inflammable sub- Largest quan- stance separated by washing, I shall speak of that collected “gti <3 from operations conducted in tubes of brass, in the manner that has been just mentioned; for it is in this way, that I have collected the largest quantities. Tt appears as a pulverulent mass of the darkest shades Its properties. of olive. It is perfectly opaque. tis very friable, and its - powder does not scratch glass. It is anonconductor of elec- tricity. rye When it has been dried only at 100°, or 120°, it gives off Heated in air. moisture by increase of temperature; and, if heated in the atmosphere, takes fire at a temperature belew , the boiling ~ point of olive oil, and burns with a red light and. scintilla- tions like charcoal. If it be excluded from air and heated to whiteness in a Heated in va- tube of platina, exhausted after having been filled with hi- °4% drogen, it is found very little altered after the process. Its colour is a little darker, and it is rather denser; but no in- dications are given of any part of it having undergone fu- sion, volatilization, or decomposition. Before the process its specific gravity 1s such, that it does not sink in sulphuric acid; but after, it rapidly falls to the bottom in this fluid. The phenomena of its combustion are best witnessed in a Its combustion retort filled with oxigen gas. When the bottom of the re- ' 0*16%" 888 tort is gently heated by a spirit lamp, it throws off most vivid scintillations like those from the combustion of the bark of charcoal, and the mass burns with a brilliant light. A sublimate rises from it, which is boracic acid; and it be- _ comes coated with a vitreous substance, which proves like-~ wise to be boracic acid; and after this has been washed’ off, the residuum appears perfectly black, and requires a higher temperature for its inflammation than the olive coloured substance; and by its inflammation produces afresh portion of boracic acid. Th oximuriatic acid gas the peculiar inflammable sub- ang in oximu- stance Tiatic acid gas. 16 DECOMPOSITION OF BORACIC ACID. stance occasions some beautiful phenomena. When this gas is brought into contact with it at common temperatures, -it instantly takes fire, and burns with a brilliant white light ; a white substance coats the interior of the vessel in which the experiment is made, and the peculiar substance is found covered by a white film, which by washing affords boracic acid, and leaves a black matter, which is not spontaneously inflammable in a fresh portion of the gas; but which im- flames in it by a gentle heat, and produces boracic acid. Heatedinhi- The peculiar inflammable substance, when heated nearly oe or nit to redness in hidrogen, or nitrogen, did not seem to dissolve in these gasses, or to act upon them; it merely gained a darker shade of colour, and a little moisture rose from it, which condensed in the neck of the retort in which the ex- periment was made. Its actien on On the fluid menstrua containing oxigen it produced ef- ee fects, which might be looked for from the phenomena of its agency on gasses. nitric acid, When thrown into concentrated nitric acid, it rendered it bright red, so that nitrous gas was produced and absorbed ; but it did not dissolve rapidly, till the acid was heated; when there was a considerable effervescence, the peculiar substance disappeared, nitrous gas was evolved, and the fluid afforded boracic acid. sulphuricacid, Jt did not act upon concentrated Jules acid, till heat was applied; it then produced a slight effervescence; the acid became black at its points of contact with the solid ; and a deep brown solution was formed, which, when neutra~ | lized by potash, gave a black precipitate. muriaticacid, © When heated ina strong solution of muriatic acid, it gave it a faint tint of green; but there was no vividness of action, or considerable solution. ; & acetic acid. | On acetic acid heated it had no perceptible action. It combined ~ It-combined with the fixed alkalis, both by fusion and’ ; ‘at fixed al- aqueous solution, and formed pale olive coloured com- alis. ; 2). pounds, which gave dark precipitates when decomposed by muriatic acid. Its action on When it was kept long in contact with sulphur in fusion, sulphur, it slowly dissolved, and the sulphur acquired an olive tint. Tt was still less acted upon by phosphorus, and after an phosphorus : hour’s DECOMPOSITION OF BORACIC ACID. 17 hour's exposure to it, had scarcely diminished in quantity, but the phosphorus had gained a tint of pale green. It did not combine with mercury, when they were heated and mercury. together. These ee Ra are sufficient to show, that the com- Differs from bustible substance ebtained from boracic acid by the agency ae ei of potassium is, different from any other known species of : matter; aud it seems, as far as the evidence extends, to be the same as that procured from it by electricity; and the two series of facts seein fully to establish the decom posi- tion, and recomposition of the acid. From the large quantity of potassium required to decom poracic acid pose a small quantity of the acid, it is evident that the bo- contains much racic acid must containa considerable proportion’of oxigen. ” tae ‘I have endeavoured to determine the relative weights of the peculiar inflammable matter and oxigen, which eomposea given weight of boracic acid; and to this end I made several analytical and syuthetical experiments ; I shall give the re- sults of the two, which I consider as most accurate. Twenty grains of boracic acid and thirty grains of potas- Apparently in sium, were made to act upon each other by heat in a tube of °™ instance 2 brass; the result did not effervesce when washed with dilu- oe oe ted murtatic acid; and there were obtained after the pro- cess, by slight lixiviation in warm water, two grains and about six Saeeaiie of the olive coloured matter. Now thirty grains of potassium would require about five grains of oxigen, to form thirty-five of potash; and according to this estimation, boracic acid must consist of about one, of the peculiar inflammable substance, to nearly two of oxi- gen. A grain of the inflammable substance in very fine pow- in another der, and diffused over a large surface, was set fire to in a retort, containing twelve cubical inches of oxigen; three cubical inches of gas were absorbed, and the black resi- ‘duum, collected after the boracie acid had been dissolved, was found to equal five eighths of a grain. This, by a se- cond combustion, was almost entirely converted into boracic acid, with the absorption of two cubical inches and one eighth more of oxigen. The thermometer in this experi- ment was at 58° Fahrenheit, and the barometer at 30:2. VoL. XX1V.—Sepr. 1809. ° Cc Accord 18 DECOMPOSITION OF BORACIC ACID. 18 oxigento. According to this result, boracic acid would consist of one feet of the inflammable matter to about 1°8 of oxigen; and the 248 per cent dark residual substance, supposing it to be simply the in- of oxigen. = flammable matter combined with less oxigen than is suffi- cient to constitute boracic acid, would be an oxide, consist- ing of about 4:7 of inflammable matter to 1°55 of oxigen. Sources of er- ‘These estimations, I do not however venture to give as en- rour both in Bee Te. ft cls : ae © : as fhe analyte & tirely correct, In the analytical experiments, there are pro synthses, bably sources of errour, from the solution of a part of the inflammable matter; and it possibly may retain alkali, which cannot be separated by the/acid. In the synthetical pro- cess, in which washing is employed, and so small a quantity of matter used, the results are still less to be depended up- on; they must be considered only as imperfect approxima- tions. Viihetees of Moma the general tenour of the facts it appears, that the boracic acid combustible matter obtained from boracic acid bears the simple or com- same relation to that substance, as sulphur and phosphorus pounded? aie : h f An dv to the sulphuric and phosphoric acids. But is it ‘an ele- mentary inflammable body, the pure basis of the acid? or is it not, ike sulphur and phosphorus, compounded ? co ak Be Bo Without entering into any discussion concerning ultimate substance most elementary matter, there are many circumstances, which fa- probably @ your the idea, that the dark olive substance is not a simple cempound, ; ‘ ‘ ; body; its being nonconducting, its change of colour by be- ing heated in hydrogen gas, and its power of combining with the ‘alkalis; for these properties in general belong to primary compounds, that are known to contain oxigen. Heated with I heated the olive coloured substance with potassium, potassium. there was a combination, but without any luminous appear ance, and a gray metallic mass was formed; but from the effect of this upon water I could not affirm, that any oxigen had been added to the metal, the gas given off had a pecu- liar srmell, and took up more oxigen by detonation than pure hidrogen, from which it seems probable, that it held some of the combustible matter in solution. ‘ It occured to me, that, if the pure inflammable basis were Exposed to the ‘ « j : action of poe capable of being deoxigenated by potassium, it would pro- oe in ‘bably possess a stronger affinity for oxigen than hidrogen, ether, , . . . : and therefore be again brought to its former state by water. . I made “DECOMPOSITION OF BORACIC ACID. iQ I made another experiment on the operation of potassium on the olive coloured substance, and exposed the mixture te a small quantity of ether, hoping that this might contain only water enough to oxigenate the potassium; but the same result occurred as in the last case; and a combination ° of potash and the olive coloured substance was produced, insoluble in ether. I covered a small globule of potassium with four or five in vaeue, times its weight of the olive coloured matter, in a platina tube exhausted, after being filled with hidrogen; and heated the mixture to whiteness: no gas was evolved. When the tube was cooled, naphtha was poured into it, and the result examined under naphtha. Its colour was of a dense black. It had a lustre scarcely inferior to that of plumbago. It was a conductor of electricity. A portion of it thrown into water occasioned a slight effervescence ; and the solid mat- ter, separated, appeared dark olive, and the water became slightly alkaline. Another portion examined, after being exposed to air for a few minutes, had lost its conducting power, was brown on the surface, and no longer produced an effervescence in water. Some of the olive inflammable matter, with a little potas- salherie ay sium, was heated to whiteness, covered with iron filings, a ings, dark metalline mass was formed, which conducted electri- city, and which produced a very slight effervescence in wa- ter, and gave by solution in nitric aeid, ‘oxide of iron and boracic acid. ) The substance which enters into alloy with potassium, and ee of with iron, I am inclined to consider as the true basis of the aie! boracic acid. In the olive coloured matter this basis seems to exist in Olive coloured union with a little oxigen; and when the olive coloured ™4™ substance is dried at commen temperatures, it likewise con- tains water. In the black nonconducting matter, produced in the com- Black matter. bustion of the olive coloured substance, the basis is evi- dently combined with much more oxigen; and in its full state of oxigenation it constitutes boracic acid. From the colour of the oxides, and their solubility in alkas The Boracic lis, from their general powers of combination, and from the Bete eceaeet Bost! C2 hens conducting First experi- ments on fluo- ric acid gas, % Fluoric acid gas introduced to potassium, and heated. An addition of hidrogem to the gas. Second appli- cation of heat, and tempera= ture raised. INQUIRIES RESPECTING FLUORIC ACID. conducting nature and lustre of the matter produced by the action of a small quantity of potassium upon the olive co- loured substance, and from all analogy ; there is strong rea- son to consider the boracic basis’as meta'lic in its nature, and I venture to propose for it the name of boracium. 7. Analytical Inquiries respecting Fluoric Acid. I have already laid before the Society the. account of my first experiments on. the action of potassium on fluoric acid gas*, -[ stated, that the metal burns when heated in this elastie fipid, and that there is agreat absorption of the gas. -Since the time that this communication was made, I have -carried on various processes, with the view of ascertaining accurately the preducts of combustion, and 1 shall now de~ scribe their results, - When fiuoric acid gas, that has been procured in contact with glass, is introduced into a plate glass retort, exhausted after being filled with bidrogen gas, and containing potas- sium, white fumes are immediately perceived. The metal loses its splendour, and becomes covered with a grayish crust. When the bottom of the retort is gently heated, the fames become more copious; they continue for some time to be emitted, butat last cease altogether. If the gasis examined at this time, its volume is found to be a little increased, by the addition of a small quantity of hidrogen. No new fumes are produced: by a second application of a low heat; but when the temperature is raised nearly to the point of sublimation of potassium, the’ metal rises through the crust, becomes first of a copper colour and then of a bluish black, and soon after inflames and burns with a most brilliant red light. B10 * Phil. Trans., Part IT, 1808, p. 343; fJournal-vol. XXI, p. 375.] The combustion of potassium in fluoric acid I have since seen mention- ed in the number of the Moniteur, already so often quoted, as observ- ed by M. M. Gay Lussac and Thenard; but no notice is’taken of the results. (They are given in our present number, p. 29.) After we INQUIRIES RESPECTING FLUORIC ACID. oe @ After this combustion, either the whole or a part of the Product of the fluoric acid, according as the quantity of potassium is great C™m>ustion. or small, is found to be destroyed or absorbed. A mass of a chocolate colour remains at the bottom of the retort ; and a sublimate, in some parts chocolate, and in others yellow, is found round the sides, and at the top of the retort. When the residual gas afforded by this operation is Residual gas, washed with water, and exposed to the action of an electri- MeToEN cal spark mixed with oxigen gas, it detonates and affords a diminution, such as might be expected from hidrogen gas. The proportional quantity of this elastic fluid differs a Its proportion. little in different operations. When the fluoric acid has not been artificially dried, it amounts to one sixth or one se~ venth of the volume of the acid gas used; but when the ~ fluoric acid has been long expesed to calcined sulphate of soda, it seldom amounts to ove tenth. I have endeavoured to collect large quantities of the cho- Attempt to colate coloured substance for minute examination ; but some elect aS difficulties occurred. sence ty When I used from eighteen to twenty grains of potas-. sium, in a retort contaming from twenty to thirty cubical inches of fluoric acid gas, the intensity of the heat was such as to fuse the bottom of the retort, and destroy the results. In a very thick plate glass retort, containing about nine- gy ocessful teen cubical inches of gas, I once succeeded in making a one. decisive experiment.on ten grains and a half of potassium, and I found, that about fourteen cubical inches of fluoric acid disappeared,and about two aud a quarter of hidrogen gas were evolved. The barometer stood at 30°3, and the - thermometer at 61° Fahrenheit; the gas had not been arti- fically dried. In this experiment there was very little sub- limate; but the’ whole of the bottom of the retort was co- vered with a brown crust, and near the point of contact with the bottom, the substance was darker coloured, and ap- proaching in its tint to black. When the product was examined by a magnifier, it evi- Productacome dently appeared consisting of different kinds of matter: a P¢™"4: blackish substance, a white, apparently saline substance, : and a substance having different shades of. brown and fawn colour. The 29, A nonconduc- tor. Action on wa- ter. Heated in con- tact with air, and in oxigen. Examination of the water, and of the ree siduum, Experiments onsmall quan- tities not de- eisive as tothe pure basis, Decomno ition of the fluoric acid analogous to that of the INQUIRIES RESPECTING FLUORIC ACID. The mass did not conduct electricity, aud none of its parts could be separated, so as to examine as to this Mic perty. When a portion of it was thrown into water, it effer- vesced violently, and the gas evolved had some resem- blance in smell to phosphuretted hidrogen, and was inflam- mabie. When a part of the mass was heated in contact with air, it burnt slowly, lost its brown colour, and became a white saline mass. When heated in oxigen gas in a retort of plate glass, it absorbed a portion of oxigen, but burnt with difficulty, and’ required to be heated nearly to redness; and the light gi- ven out was similar te that produced by the combustion of liver of sulphur. The water which had acted upon a portion of it was exa- mined; a number of chocolate coloured particles floated in it. When the solid matter was separated by the filter, the fluid was found to contain fluate of potash, and potash. The solid residuum was heated in a small glass retort in oxi- gen gas; it burnt before it had attained a red heat, and be- came white. In this process oxigen was absorbed, and acid matter produced. ‘The remainder possessed the properties of the substance formed from fluoric acid gas holding sili- ceous earth in solution, by the action of water. Jn experiments made upon the combustion of quantities of potassium equal to from six to eleven grains, the portion of matter separable from the water has amounted to a very small part of a grain only; and operating upon so minute a scale, I have not been able to gain fully decided evidence, that the inflammable part of it is the pure basis of the fluo~ ric acid; but with respect to the decomposition of this body by potassium, and the existence of its basis at least combin- ed with a smaller proportion of oxigen in the solid product generated, and the regeneration of the acid by the ignition of the product in oxigen gas, it 1g scarcely possible to en- tertain a doubt. , The decomposition of the fluoric aeid by potassium seems analozous to that of the acids of sulphur ‘and phosphorus. In neither of these cases is the pure basis, or even the basis in mena observed during this experiment are to be ascribed to proves these. oxigen, on the contrary show, that this principle acts no part in it? and that it is rather a supracomposition of the boracic acid, than the loss of one of its principles, which oc- easions the new properties it acquires? However, if this supracomposition of the boracic acid be Porea sUprae not admitted, how shall we explain why there is no hidro- Compound. gen, or next to none, disengaged during the decomposition . of This accounts for the hidro- gen appearing in no form. Phenomena of the combus- tion of bore. Hidrogen and carbon more dense in bore than in potas- siuni. DECOMPOSITION OF BORACIC ACID? of the alkaline metals by this acid? How too happens it on the hypothesis of it disoxigenation, that no water is produ- ced? Can we admit the disoxigenation of one substance, and the dishidrogenation of another at the same time, with- out producing water sufficient to be collected; and have its weight calculated ? Undoubtedly not. Thus, were this the only objection to the decomposition of boracic acid, it would suffice to prove, that the new state, in which this acid is ob- tained, is not owing to its disoxigenation. But as there are still many other objections, which the philosophy of the science suggests, we cannot do otherwise than consider the new substance, into which the boracic acid is converted, as a combination of this acid with the hidrogen and the carbon, that it has taken from the alkaline metal. According to this theory we find no difficuly {in explain- ing, why, during the action of the boracic acid on the me- tal of potash, neither water nor hidrogen is disengaged ; while on the hypothesis of the disoxigenation of this acid, we know not what becomes of the hidrogen, which the al- kaline metal must necessarily lose. . This explanation, independently of its accounting for all the phenomena, has the farther advantage of leading to a more simple definition of an important point in chemistry, on which the opinion of chemists is not yet thoroughly fixed. With respect to the phenemena exhibited by the combus- tion of the substance, that produces the beracic’ acid, they are owing to the oxigenation of the hidrogen and carbon, which this acid had abstracted from the metal of potash; so that by the subtraction of these two principles it be- comes boracic acid again, as by the same subtraction the alkaline metal had again become an alkali. If we consider too, that hidrogen and carbon, in ihieer state of combination with boracic acid, are less oxigenizable than they were when combined with the alkali, every thing leads us to believe, that this arises from the two principles having acquired a fresh degree of condensation at the ins stant of their union with the boracic acid: and what ap- pears to give some foundation to this conjecture is, that, at the moment when the combination takes place, the matter a instantaneousl y DECOMPOSITION OF FLUORIC ACID. 99 instantaneously becomes incandescent, a state that announ< ces a gréat emission of caloric, and consequently a sudden condensation of some principles. | { shall not terminate this note, without imparting to the institute a fact, that appears to me very important, but from which I shall refrain from drawing any inference. It is as follows. I have observed, that in several experiments I made to de- meh qa 4 - compose borate of soda by means of charcoal, metallic glo- in a mixture bules were produced, which appeared to be formed in the on midst of the mixture: but as I found, that this metallic , product was of the same nature as the vessel in which I made my experiments, I intend to repeat them in a tube of platina, in order to ascertain, whether those of iron, which I employed, did not concur in the formation of the metallic globules I obtained. However, this is not the only occasion, on which I have 2nd in other found similar globules. I had before remarked them in” the mixtures I had made for the purpose of producing the alkaline metals with charcoal. IV: Abstract of a Paper on the Decomposition and Properties of the Fluoric Acid, presented the Qth of January to the Ma- thematical Class of the Institute, by Messrs. Gay-Lussac and THENARD*. Messrs. Gay-Lussac and Thenard, having decom-= Potassium ap- posed the boracic acid by means of the metal of potasht, plied to the decomposition could not but try the same method of decomposing the o¢ quoric acide fluoric and muriatic acids, the constituent principles of which were not yet known. This they have effected with - respect to the fluoric acid, and they now we pePlie the principal results of their labours, » * Journal de Physique, January 1809, p. 95, For Mr. Davy’s expe- _ fiments on the ae of fluoric acid, see p. 20, of our present number, © + Seq Journal, Vol. XXII, p. 260, Our - 80 DECOMPOSITION OF FLUORIC ACID. Attempts to Our first care, say they, was to obtain pure fluoric acid : Seine ai) but as this acid exists only combined with lime, and no one BOTIC ach . . : lias yet been able to separate it, without its entering into combination with some other body, we were obliged to make a great number of trials, that procured to us the ad- vantage of observing several facts, the most remarkable of Gas procured which are the following. When air is placed in contact sh. nelaeh with the fluoric gas disengaged from a redhot iron tube racic acid pro Containing fluate of lime and glacial boracic acid, vapours duces va;our gye formed as dense as those arising from muriatic acid gag with all gasses les : containing and ammonical gas. It produces the same with all the water. other gasses, except the muriatic acid gas, provided those gasses have not been dried. But it does not alter the trans- parency of any of them, if they have remained some time in contact with lime, or muriate of lime. Inthe first case, where - there is a production of strong vapours, the volume of gas diminishes equally, and only a few hundredths at the tem- perature of 7° [44°6° F.]. In the second case, where the gasses retain their transparency, their bulk does not alter. Hence we may infer, that flueric acid gas is an excellent mean for indicating the presence of hygrometrical water in gasses ; and that all contain some, except the muriatic acid No water pre- gas, fluoric gas, and probably ammoniacal gas. For this cipitated from yeason, if we expose fluoric gas to a cold of 15° or 19° [5° oighali above or 2°2° below 0 F’.], we find no trace of lquid sepa- rated; while on exposing sulphurous acid gas, carbonic acid gas, &c., to the same degree of cold, water is suddenly de- posited. | It has a great The dense vapours, produced by fluoric gas in the gasses affinity for that contain hygrometrical water, announce in it a great ial affinity for this fluid: and indeed it is no exaggeration to say, that water can absorb more of it than of muriatic acid gas, and probably more than two thousand times its Propertiesof bulk. When water is thus saturated with it, it is limpid, eee faming, and exceedingly caustic. About a fifth part of , what it contains may be abstracted from it by heat ; but, do what we'will, it is impossible to get more. It then resem- bles concentrated sulphuric acid: it has its causticity and appearance : like it its boiling point is much above that of water, and it condenses entirely in striz, though it contains: still DECOMPOSITION OF FLUORIC ACID. 31 still perhaps sixteen hundred times its bulk of gas. Is it Sulphuric and not hence extremely probable, if not even demonstrated, nitric acids A ad give : 4 always con- that the sulphuric and nitric acids would be in the state of tain water. gas, if they were pure ? and that they are indebted for the liquid state, in which we see them, to the water they con- tain? , Though our fluoric gas has a great affinity for water, Fluoric gas é E cannot dis- and contains none, since it is obtained from matters per= solve water, fectly dry, &c.; yet it cannot dissolve or convert into gas the smallest quantity. We kept a quart of fluoric gas in contact with a single drop of water over mercury for several hours ; and this drop, instead of disappearing, increased in size. Hence it is proved, that this gas cannot contain water in any manner, either in the hygrometrical state, or in a state of combination. Ammoniacal gas is precisely in the Ammoniacal same situation, at least with respect to combined water, $*5 #miler. But it is not the same with muriatic acid gas: this it is true Muriatic acid contains no hygrometrical water, but it contains water inti- $$ contains . : water In Come mately combined, as Messrs. Henri and Berthollet first pination. showed. By passing muriatic gas, in a gentle heat, through litharge, melted and reduced to a coarse powder, we have accomplished the extraction of this water, and caused it to appear in streams. From the experiments we have made on the direct combination of a certain quantity of this acid with an excess of oxide of silver, it must form about a fourth of its weight. The other gasses do not comport themselves with water Alt other gasses like the preceding. No one contains combined water, but ie ac all contain hygrometrical water. Hence it follows, that fluoric acid gas and ammoniacal gas contain neither hygro- metrical water, nor combined water*: that muriatic acid gas contains no hygrometrical water, but does contain com- ' bined water; and that all the other gasses contain only hy- grometrical water. What is most striking in these results is to see, that mu- Proportions of riatic acid gas contains water, and that the fluoric and am- Water in muri- ; atic acid gas, * It is certain, that, from the experiments of Mr. Berthollet jun. ammoniacal gas contains no combined water; but Gay-Lussac and The- nari do not yet venture to affirm, that it contains no water in the hy- grometrical state, mioniacal 32 or rather the elements of water. Action of flu- oric gas on ve- getable matter. A very potent acid. But it was a compound of the fluoric and boracic acids. a DECOMPOSITION OF FLUORIC ACID. moniacal gasses contain none; and particularly to find, that the muriatic acid gas contains it m such proportions, that, if it were entirely decomposed by a metal, all the aad would be absorbed by the oxide, and converted into a me- tailic muriate. This, as we have satisfied ourselves, takes place, when muriatic acid is gradualty and successively passed through sév eral redhot gun barrels filled wean iron turnings. © , The more we reflect on all these phenomena, the more difficult we find it’ tovaccount for them, Is it not possible however, that oxigew and hidrogen may be two of the con- stituent principles of muriatie acid, and that they are not in’the state of water in it, but that this is formed when the acid enters into combination with bodies, so that in the mu- riates it is quite different from what it is in the state of gas? Be this as it may, it is certain, that all the muriates inde- composable by fire, and which contain little er’ no water, cannot be decomposed, even at a very high temperatifre, either by the vitreous acid phosphate of ‘nid, or by the boracic acid; that thus thé acid is retained with very great force in the muriates; and that sulphuric acid itself, if deprived ‘of water, very probably could’ not decompose them. “But we will quit this hypothesis, and return to an examination of the properties of our fluoric gas. ; ‘We have considered already its physical properties, its action on the air, on all the gasses, and on water. Let us now consider how it ‘acts on vegetables matters, ‘These it attacks at least as powerfully as the sulphuric acid; arid, like this acid, appears to act on them by occasioning water to be formed, forit chars them: Thus it readily converts alcohol into an ether, which we purpose to investigate ; and instantly blacken the driest paper, diffusmg a vapour, which is owing to the water that is formed and absorbs it. Every thing thea demonstrates to ns, that this fluoric gas is one of the most powerfal acids, and that it is not inferior in strength and causticity to concentrated sulphuric acid ; yet it has no action on glass. Hitherto we had supposed, that it was pure: but then we suspected that it contained. something, which prevented its action on silex ; and in fact or soon DECOMPOSITION Of FLUORIC ACID. 33 s60n found, that it held in solution a pretty large quantity > of boracic acid. ‘ The fluoric acid arising from the decomposition of fluate riake lose of lime by boracic acid not being pure, we attempted to nharotot baie prepare it by decomposing this salt by the acid phosphate ‘Sapiens flue- of lime. We obtained but very little; and what we did with silen ur Be obtain contained in the first place the small quantity of silex, that existed in our fluate of lime, and secondly a cer« tain portion of the acid phosphate of lime itself. What is remarkable in this process is, that, when we used a siliceous fluate of lime, the decomposition of the salt was very rapid, in consequence of the action of the silex on fluoric acid, and gave rise to a great deal of siliceous fluoric gas. Considering then, that the fluoric gas arising from the Fluate of lime fluate of lime and boracic acid contained no water, and a ocala was not capable of dissolving any, we thought, contrary to acid ia leadane the generally received opinion, that the case would proba- Yéselé bly be the same with that prepared in leaden vessels by means of concentrated sulphuric acid, But instead of obtaining the acid in the state of gas by yielded only a this means, we had it in a liquid state, and possessing the liquid acid. following properties. In the air it emits dense vapours: Lts properties, with water it heats and even enters suddenly into ebullition : it scarcely comes into contact with glass before it destroys its polish, heats strongly, boils, and is converted into sili« ceous gas, Of all its properties the most extraordinary is its action on the skin. It scarcely touches this when it dis- Singularaction organizes it. A white spot is immediately seen, a great 0 the skin. pain is soon felt: the parts adjacent to the point touched speedily grow white and painful; and in a little time a blister is formed, covered by a thick white skin, and cona taining matter. However small the quantity the phenomena equally take place; only they proceed more slowly, so that sometimes they are not observed till seven or eight hours after the con- tact; and still the burn will be sufficiently severe, to cause acute pain, deprive the patient of sleep, and excite fever. The effects of these burns, as we are convinced by our own experience, may be stopped by the immediate application of » iy a weak solution of caustic potash ; which we know too, by against burns, Vor. XKIV..—Serr, 1809. D expes \ 54 DECOMPOSITION OF FLUORIC ACiD: experience, to be an excellent remedy against commow, burns. Action of this It may readily be supposed, that we did not neglect to wei on pot place such an active liquid in contact with the metal of, ’ potash. This experiment was made in acoppertube. At. first we threw a piece the size of a small hazel nut into, a small quantity of this liquid; and immediately a very loud . detonation ensued, with a great evolution of light and heat. Afterward, desirous of knowing what was the cause of these: phenomena, we caused the fluid to arrive at the metal gradually. In this way but little heat is produced, and we: could collect the products of the experiment. These pro-= ducts were hidrogen, fluate of potash, and water. Con sequently this active liquid is‘a eae of fluoric acid and water. It ingen? We see then, that this acid tends to combine with all lint and is Substances, and that it forms with them solid, liquid, or the strongest gaseous compounds, according as it retains more or less weae elasticity, or expansive force. It is the only acid with which this is the case: and this property is even’a proof, that itis the strongest and most active of acids. Fluoric acid Since we cannot in any way obtain fluoric acid pure, we solace can only study it when in combination with some substance. We must take it then combined with this or that substance, according to the result we wish to obtain. Siliceousfluoric Tf the object be to unite it with alkalis, earths, or me acid forms tri- ple salts with tallic oxides, we must be careful not to employ siliceous alkalis, earths, fgoric acid, for in this case we should obtain triple salts. bie oor Thus, on pouring ammonia into acid fluate of silex, we obtain a triple salt nearly insoluble, yet in great measure volatile. Thus too, on pouring muriate of barytes into acid fluate of silex, we obtain after some time a crystalline Eg is eee insoluble in w great excess of nitric acid, which might be mistaken for sulphate of barytes, and is nothing ‘Bae fluate of silex and barytes. For decompo- But when, instead of wanting to combine thi acid a eh cal with these substances, we wish to decompose it, as we pur= ployed. posed to do by means of the metal of potash, it is evident, that we ought not to empldy liquid fluoric acid, on account of the water present with it; and that we should prefer, ei< ther DECOMPOSITION OF FLUORIC ACID. 85 ther the fltioric gas holding in solution boracie acid; or ras ther the siliceous fluoric gas, because the foreign matter in this, containing nothing combustible, cannot lead us into errour, and can be of no injury farther than giving an ad- dition of this matter. Accordingly we employed these gasses, and chiefly the siliceous fluori¢ gas; in our experi- ments on the decomposition of the fluoric acid, of which we shall now proceed to give an account. When the metal of potash is placéd in contact with sili- Action of pw ceous fluoric gas at the common temperature, it undergoes alee no perceptible alteration, except becoming slightly dull on gas. the surface: but if it be melted, it soon thickens; and burns vividly, with the extrication of much heat and light. In this combustion there is a great absorption of fuoric - acid, very little hidrogen gas is disengaged, the metal diss appears, and a solid substance of a reddish brown colour is produced, _ If this substance be treated with cold water, hidrogen The product gas is evolved, though it appears | ne longer to céntain any es with metal. If, after having treated it with cold water, it is : treated with hot, more hidrogen gas is evolved, but less than the first time; and on the whole scarcely a third as much as the metal itself would yield with water is obtained. If the waters of elutriation be added tegether and evapo- rated, we obtain from them nothing but fluate of potash with excess of alkali; and if we examine the residuum, which, when well washed, is still of a reddish brown colour, we find it to possess the following properties: When thrown Residaum into a silver crucible at a cherry red heat, it burns vividly, '¥™e4 in ait, and disengages a little acid gas; after which, from being insoluble in water, it becomes partly soluble. The portion that dissolves is fluate of potash; that which does not diss solve is siliceous fluate of potash. If, instead of making the experiment in a crucible, it be and in oxigen _ dohe in a small bent glass jar filled with oxigen gas, and 8** heated gradually, the inflammation is more vivid than in common air, a great quantity of oxigen is absorbed, and the gas that remains after the combustion is nothing but ‘pure oxigen, pin the addition of a little fluoric acid. The D2 : produst 86° BLECOMPOSITION OF FLUORIC ACIDs » product is solid, as in the preceding experiment, and i# formed of fluate of potash and silex. Thefluoricgas It is now evident, that, since little or no hidrogen gas is i... he evolved on burning the metal of potash in Auoric acid gasy combines with this combustion cannot be ascribed to water. Hence in this polassium experiment either the fluoric acid is decomposed, or it com- without oxid- |. ; 3 ot ahah ng it. bines with the metal without oxiding it. These two hypo- theses being the only ones that can be formed, let us dis cuss them in succession. If it were the metal, that com- bined entire with the fluoric acid, the probable result would be a very inflammable compound, which with water would give out as much hidrogen as the metal itself. But we ob- tain only a third of what ought to be evolved. Besides, a combination of this kind 1s contrary to all the facts on alk possible suppositions ; whether we eonsider the action of the fluoric acid on the metals and alkalis, or the action of the It is probably metal of potash on all the other acids. Hence we must decompose’s Conclude, that the fluoric acid is probably decomposed. Consequently in this decomposition must be formed a com- pound of the fluoric radical with potash and silex. It aps pears, that, when this radical is combined only with potash, it is capable of decomposing water like the phosphurets ; but that, when it is combined with potash and silex, it does not decompose it, no doubt because this triple compound is insoluble. Potassium ea- Be this as it may, it is extremely easy, to effect the com~ fic ee in’ bustion of the metal of potash in fluoric gas, Wh fluoric gas in bustion of the metal of p n fluoric gas, en we - smal} quant’ would burn only a small quantity of the metal, the opera- “ tion may be performed very conveniently over mercury in 2 little glass vessel blown by a lamp, to the top of which the metal is conveyed on an iron rod, and which is heated by @ burning coal till the inflammation commences. or in large. But if we would burn large quantities of the metal, the operation should be peifataual in a jar holding about a ‘quart. This is first to be filled to within two fingers breadths with fluoric acid gas. The metal is then to be conveyed into it by means of an iron wire properly bent. A snvall capsule, which may be made of a crucible by re- moving a portion of the sides, being heated toa cherry red, is then to be introduced, holding it in a pair of tongs; and whea PROCESS FOR METALLIZING POTASH AND SODA. 37 when it is emptied of the mercury by shaking it, the metal of potash is immediately to be placed init, and it will pree sently burn with great force. The combustion being finished, and the capsule cooled, it is to be taken out, and the matter separated with a small spatula. This done, ano- ther portion of metal may be burned in this little capsule in the same jar; provided a quantity of fluoric acid, equal to what was absorbed in the first combustion, be passed up jnto it. A third and a fourth combustion may be accom- plished in the same way. There is nothing to prevent this, since the jar may always be kept equally full of fluoric acid gas, and the metal is easily procured at pleasure, by following the process we have recommended. We will add, Care must be Evever,. that for the complete success of these experiments, sean great care must be taken, to remove the oil from the sur- from oil. face of the metal with blotting paper; otherwise it will be decomposed, and give out a little hidrogen gas and carbon. In fact this inconvenience cannot be entirely avoided; and whatever precaution be taken, there is always a portion of oil interposed between the particlesof the metal: but the quantity is so small, that it need not be regarded, and cannot be the source of any errour in the results. To this oil is owing the preperty of rendering lime-water turbid, that the metals of potash and soda sometimes possess, va Description of a Process, by means of which Potash and Soda may be metallized without the Assistance of Iron; read before the French Institute the 18th of April, 1808 ; _ by F. R. Curavupau*. . ] HE decompesition of the alkalis, which I never consi Atkalis long dered as simple bodies, having long been an object of re- oe search with me, I was eager to repeat the experiment, in ; * Journal de Physique, April 1808, Pp. 320. ! which 38 PROCESS FOR MEPALLIZING POTASH AND SODA, Their metalli- which Messrs. Thenard and Gay-Lussac announced potadly gation by means x of iron doesnot 2d soda could he converted into metals by means of iron, always suce Not having obtained more satisfactory results however than core. others, whom [ have known to repeat the same experiments, { thought it right to pursue the researches I had already ‘begun on the same subject, and the success of which ap- peared to me the more certain, as already the beautiful ‘experiments of Mr. Davy had thrown great light on some ~phenomena, which I had observed, but which. I could. not ‘before explain. Ysthe prussiate’ In fact, if, according to the hypothesis of the celebrated boll ea ae English chemist; potash and soda be metallic oxides, is it the metal with not more than -probable, that the prussic calcinations are eapbon? simply the combination of this metal with charcoal? Such at least was my opinion at that time; and it will appear ‘how far it was well founded, since | have accomplished the metallization of potash and of soda, by heating strongly the alkali with charcoal, a process which, it is obvious, ranks among the prussic caleinations. The metal of . The metallization of potash or soda taking place with the fixed alka- lis obtainable ; Vie J by two pro as well in stone retorts as in iron tubes, the first or second fad so process may*be employed indifferently. As to the nature of the vessel, T prefer iron, because it is more permeable to caloric, and less subject to fusion than the stone ware, pare ticularly when the latter is penetrated with alkali; an inconvenience, that preveuts the operation from being continued to the end, which does not happen so frequently » with iron. either of the two mixtures I shall mention, and succeeding Process the first. Yst preeess. © Mix intimately four parts of animal charcoal well pow= dered with three of carbonate of soda, dried on the fire” without having been fused; and mix the whole with a suf+ ficient quantity of linseed oil, but uot so as to form a "paste, . 7 Process the second. $0 process, Take two parts of flour, and mix them intimately with one part of carbouute of soda prepared as in the preceding j process, PROCESS FOR METALLIZING POTASH AND SODA. process, and add to this mixture as much linseed oil as it will bear without ceasing to be pulverulent.: 39 Whatever be the kind of vessel employed to calcine this Manipulation. matter, and whether it be the first or second mixture, we must always begin with heating it gradually: but as soon as the matter is obscurely red, the fire may be increased, till a fine sky blue light, surrounded with a greenish aureola, is perceived in the interior of the retort or iron tube. To this light will soon succeed a very copious vapour, which obscures all the interior of the vessel. This is the metal, which is disengaged from the mixture. The fire must then be urged no farther,” for at this temperature the retort be- gins to fuse; and if the iron resist better, it is because the alkali penetrates it less readily than it does the stone ware, and likewise because the heat it receives is sooner transmit- ted to the matter within. To collect the metal in proportion as it forms, introduce Collection of into the vacuum of the apparatus a_rod of iron well cleaned ; and, as it must not have time to grow red hot, take it out again in four or five seconds: it will then be found covered bith metal, to remove which the rod is to be plunged in- stantly into a glass cucurbit filled with essence of turpene tine. This cucurbit should be immersed in a tub of water, to prevent the essence from boiling: and notwithstanding this precaution, it will be heated so much sometimes as to take fire on the immersion of the iron rod. _~ To execute these processes well, three persons are neces sary. One should take care of the fire and work the bel- lows. The most active should collect the metal as it is produced, and with the utmost celerity plunge the iron rods into the essence. The third must separate the metal that is on the rods, and then plunge them into water; not only to cool them, but also to remove the alkali, that may have escaped metallization, or been formed by combustion previous to the immersion of the metal in the essence of turpentine. He must likewise take care, to wipe the rods perfectly dry, that he who collects the metal may have no- thing else to do. _ These processes, while the metal is producing, requires in the operators a dexterity not inferior to the celerity I hare the metal. - Circumstances necessary to ENSUTE SUCCEESa 40 NEW PROPERTIES OF THE ALKALINE METALS, have recommended, The attention of him who manageg the bellows too is an object of no little importance; for, if he suffer the fire to slacken, the metal will immediately cease to be disengaged, and the reds will be covered with nothing but pure alkal. On the contrary, if he increase the fire at this period of the process, the apparatus will melt, and the experiment fail. This proves how high but uniform the temperature must be. JI have observed, that the metal is always produced at the heat of melting iron, Accordingly an iron tube will seldom serve twice, and res torts always melt before the whole of the metal is obtained. The metal a ‘| intend to inform the public of the observations, that I i aa may hereafter make on this metallic product; but im the mean time I think I may conclude from my experiments, that the production of the metal is not owing, as has been said, to the disoxigenation of the alkali; but that it is q new compound, in which hidrogen appears to haye entered into combination, and I conceive in a state of great con- densation. Hidrogen, al- Be this as it may, during the whole of the operation hi-+ eae drogen, alkali not converted into metal, and prussic radical given out. in the state of gas, continue to be disengaged. The last in particular I have collected in pretty considerable quans tity. Hidrogen an These results tend to prove, that hidrogen is one of the get Hes component parts of the alkalis, the extrication of which is charcoal. promoted by the charcoal; or that charcoal itself is a com-~ pound, one of the principles of which ig hidrogen. There js no alternative, but one or the other of these hypotheses. VI. Observations and Experiments on the Nature of the New Pro= perties of the Alkaline Metals: by the Same*, Phenomena Srv ERAL of the phenomena, that accompany the me- not explicabl 5 gee z ene p lic: by supposing * tallization of potash and soda, being inexplicable on the hy- * Journal de Physique, June, 1808, p, 42. UM ay pothesis MEW PROPERTIES OF THE ALKALINE METALS, 4} pothesis of the alkalis being simply disoxigenized ; and this the alkalis te theery besides agreeing neither with the propertics of the 2 Og a ox exigen, nor with those of ammonia, the principles of which should be analogous to those of potash and soda; Ii could fot join in opinion with those chemists, who conceive the metallization of potash and soda to be merely the result of the disoxigenation of these substances, On the contrary, witheut prejudging any thing, I would consider only the facts ; and in particular endeavour, if possible, to increase the series of those already known, What rendered these researches still more interesting to Decomposi- me were the results of the experiments I had the honour to "Se Lae ataiem communicate to the class in the year 10 [1802 or 1803]; re- 4 long ago, sults that merited the attention of chemists the more, as the consequences I deduced from them predicted in some sort ' the possibility of metallizing the alkalis, the decomposition of which I announced. Thus it is obvious, that Mr. Davy’s discovery of the me- Mr. Davs’s tallization of the alkalis by the galvanic pile could not fail pn nea ‘to awaken in me the desire of being aequainted with these thor’s atten- new products; and that, full of this subject, I should be ssi one of the first to repeat the experiments announced for me- tallizing the alkalis, experiments in which I should have had the priority, had their publication been deferred an- other week. Be this as it may, I have the satisfaction likewise of hav- This process ! : : : . more generally ing discovered a process, which is peculiar to myself, and lis ht which succeeds in every laboratery; while I cannot say so that of the much of the experiment I have repeated, since, whatever ther Freach : : chemisty. pains I have taken, | have been able to obtain only a ferru- ginous alkaline alloy. It would be very desirable however, to learn where the qf the metal difficulty lies, that every one may be enabled to repeat the be obtained experiment with equal success. What makes me particu-}* Asi aaa larly urgent for a knowledge of the means is, that, if it were contains caz- proved to me, that the metal of the alkalis could be obtain- gee ed separate by the assistance of iron, I should deduce this consequence from it ; that the carbon, which enters into the composition of the alkaline metals, is one of the elements of aS ‘Two experi- ments demon- strate the pre- sence of ear- don in the new metals. WEW PROPERTIES OF THE ALKALINE METALS, ef iron, which would tend to confirm the opinion I haye given in my paper on the decomposition of the alkalis. « Bat I stop here, not to anticipate the question whether the metal of the aikalis contain carbon; for since J had the honour to address a note to the class, in which I mentioned two experiments, that appeared to me well fitted to demon- strate the presence of carbon in the alkaline metals, doubts on this important point have arisen, J request the class therefore, to allow me to make twa experiments in its pre- sence, against which I think nothing can be urged. The first is the separation of the carbon contained in the metal of the alkalis without combustion: the second is the oxidation of the carbon, so as to convert it directly into car bonic acid. That of hidtee As to the hidrogen, it is not so easy to demonstrate its gen NOt so evi- dent. Thealkalis not presence ; particularly for one like me, who must be ten times in the right, to prove one truth. However, if I demonstrate, that the alkalis are not oxi- being oxides genized bodies, I shall have attained my object; and the the principal ebject. Grounds of the question, whether hidrogen enter into the composition of the alkaline metals will be but asecondary consideration, which I propose to examine in another point of view, I now proceed to the experiments, which may render us better acquainted with the nature and properties of the al- kalis in the metallie form. . Exp. 1. To prove the presence of carbon in the alka- author’s pro- line metals, if was necessary for me to have recourse to the €ess, Sitex action of a substance, with which the alkalis have more affi- nity, than they have with the principles that constitute them metals; and which at the sare time should be incapable of furnishing any element, that would combine with those I sought to separate from the metallized alkalis. By these means I was sure of having the carbon separate, and thus furnishing a new proof, that the carbonic acid produced in burning the metal in lime-water arises from the oxigenation of the carbon. Silex, from its indestructibility, the state of purity in which it is obtainable, and particularly its affinity for the al- kalis, appeared to me to unite all the properties, that I wished NEW PROPERTIES OF THE ALKALINE METALS. 43 wished to find in the substance, which was to be employed in my experiment. In fact, having heated silex in a glass tube with a little of decomposes the alkaline metal, it combined with the alkali, and set free iar orreeeN the carbon. free. - The carbon thus separated no longer took fire in the air; it required the assistance of heat. _ Exp. 2. This experiment is that to which I alluded in Sodium encles the note I had the honour to address to the Class. It con- eae sists in enclosing i in a thin bit of lead a ball of the metal of limewater, is soda, and then immersing it in a vessel filled with lime-wa- Raat ter. The metal thus confined is obliged to oxigenize itself acid. “be at the expense of the oxigen of the water. Two affinities concur, to effect this decomposition: the first is that of the alkali for water, the second that of carbon for oxigen; an affinity so much the more energetic, as in this state the car- bon exhibits to us a very remarkable instance of its great propensity to become oxided; a propensity, which I shall refrain from explaining at present, for the consequences I . should deduce from it would no doubt appear premature, considering the present state of our ehemical knowledge. I therefore defer till another opportunity the communication of my ideas on this great and important question. If in this second experiment I recommend taking the me- Sodium pre tal of soda, it is on account of its solidity, which. allows it fetable to po- to be handled; and because its destruction is more slow, an marrage advantage, that. allows us to observe the phenomenon of | the decomposition of water for some time, If, on the con- trary, the experiment were made with the metal of potash, the decomposition of the water would be instantaneous; which, on the one hand, would oppose the combination of carbonic acid with lime-water, and on the other would force the gasses resulting from the decomposition of the metal to break the ebstaeres opposed to jt by the lead, in which they would be included, We see then, that the metal of potash is eminently com- Cause of their bustible, and that of soda is less so; a property explicable eae we by the difference of affinity of these alkalis for water. rep One remark that I have made, and that will form the sub- Detonation of ject of a very curious experiment, is, that, in collecting the as in ‘ , metal. 44 Esperiment, General con- clusions, Jury masts ea- sly provided, IMPROVED JURY MASTS. metal of potash by means of iron rods, very loud detonas tions may he produced, the intensity of which is very simis lar to that of gunpowder employed in ten times the quan« tity. j | The following is the method of repeating this experiment with success. Instead of immersing the iron rods into es- sence of turpentine, the instant they are removed from the gun barrel to collect the metal, they must be plunged sud- denly and perpendicularly into a bucket of water. An ex plosion will then take place, the loudness of which will be in proportion to the quantity of metal, and the diameter of the iron rod. From the experiments and observations I have had the honour of communicating to the class, it follows: Ist, That the conversion of the alkalis into metals is not a disoxigenation of those substances; and that, on the con trary, 1t is a combination of the alkalis with new elements. adly, That the affinity of the alkaline metals for oxigen is merely a chemical illusion, occasioned by a substance, the existence of which was not suspected, 3dly, That carbon is one of the constituent principles of the alkaline metals, since it can be obtained separate from them at pleasure, or converted into carbonic acid by oxiges nation. Athly, That, if the specific gravity of the alkaline metals be less than that of water, it is because hidrogen probably accompanies the carbon in this combination. S5thly, That the disoxigenation of substances, attempted to be effected by means of the alkaline metals, will always yield equivocal results, until we have a knowledge of all the elements, that compose these singular substances. Vil. Improved Method of Forming Jury Masts: by Captain _ Wiutiam Bouton, of the Royal Navy*. ‘SIR, \Hlerewrra you will receive the model of a plan for | fitting ships’ jury masts, to be formed from the spare spars ¥* Trans. of the Society of Arts, vol. XXVI, p. 167. The silver medal of the Society was voted to Captain Bolton for this improvement. usually THFROVED JURY MASTS. AS Wsually carried on beard King’s ships, and in every mer- peas a of ehantman that is properly found. By having jury masts so j uch sail as | fitted, ships will be enabled to carry as much sail’as on the sai Sipe usual regular mast; the great use of which I need not dwell , on, only observing, that it may be of great importance to fleets after a general action, or when in want of proper lower masts, either at home or abroad, and enable ships, after the less of their mast, to prosecute their voyage, or service, with eut any deficiency of sail. I beg you will be pleased to lay it before the Society, and J have the honour to be, Sir, Your obedient humble servant, WM. BOLTON. = a REMARKS. In the model in the Society’s possession the main mast is Method of cen- broken about one third of its length above the deck, proper neon aay partners are secured on the deck, in which a hand mast and spare main top mast are fixed on each side of the broken main mast, and secured thereto by two spare caps, morticed on a square made in its centre. A strengthening cap, mova« ble on these additional masts, connects them, and the upper parts of these masis are sec.:red tirm!y by trustle trees in the main tep, The foot of a spare fore topmast passes through a cap made from sirong plank, morticed into the heads of the two temporary masts above mentioned, goes through the maita top, and rests in the movable strengthening cap, which con-< nects those two masts, and enables the for- topmast to be raised to any height which the main top will admit, and be then firmly secured by the upper cap, the main top, and the strengthening cap below it. The fore topmast being thus adjusted, the cross trees and topgallantmast are mounted upon it, which completes the whole business. Twocapsare the only things necessary to be made express- ly for the purpose, the other articles being usually ready om hoard the ship, In aé {IMPROVED JURY MASTSs Explanation of In Pl. I, figs. 1,2, and 3, A A represent the partners otf the plate. pieces of timber, which are bolted to the quarter deck for the mast to rest upons B is the stump of the lower mast; which is cut square at the top, and of the same size as the head of the mast originally was; upon this. square, the main and spare lower caps aa are fixed; two mortices must be cut in the partners A\A to receive squares made at the lower ends of the two temporary masts D Dy, which are sup- ported by the caps aa, one of them is a spare main top- mast, the other a hand mast; these two support the main top E, additional squares being made on the tressel trees to receive each of them. . & isa cap shown in fig. 2, made of four inch plank doubled for the purpose, and fitted upon the heads of the masts DD, for a fore topmast FF, the heel of which rests in a mortice made in the stump of the lower mast; it is also steadied by a double cap G, sepa- rately shown in fig. 3, on which it fids finally on the top. The topgallantmast H is fixed to the mast F by the top and cap in the usual manner. The figures 2 and 3 show the caps separated from the masts, and are the only things necessary to be made for the purpose; and the object of the cap, fig. 2, is to steady and to prevent any wringing of the lower jury masts, and to fid the topmast whenever it is reefs ed. The fore topmast FI’ appears in two separate pieces, @n account of its length. Vill. $ An Improvement in the Construction of Anchors, to render them more durable and safe for Ships: with an improved Mode of Fishing Anchors. By Captain H. L. Baty, of the Royal Navy*, SIR, Anchor stocks "Tue great expense of timber in the navy for anchor Remacisis = stocks, and the frequency of their failing or giving way in * Trans. of the Society of Arts, Vol. XXVI, p 170. The silver me dal of the Society was voted to Capt, Ball for these improvements, | the iMPROVEMENT IN ANCHORS. 47 the centre, where the square of the anchor is let into the stock, have induced me to offer to the Society of Arts kc. a plan of an anchor, which may be cheaper in constructiony and more likely to hold in various situations than those in common uses The model I have sent will sufficeintly explain my in= The improve tention; and show how beneficial it may be in strengthening ment strength- the anchor stocks. I wish much to notice to you its pro- ee bability of holding in the ground longer than other anchors, hold better, on account of the additional weight of the stock; and this will more particularly be the case in banks which shelve suddenly down from the shore, such as at St. Helena, Caw- sand Bay; and indeed in most of the islands in the West Indies. The proportion of additional iron, as explained by my mode}, is in all anchors to be twice and a half the-dia- meter of the shank from each side at the stock, and of course this mode will supply the place of the present nuts, which are only intended to prevent the stock from slipping in and out, whenever it becomes loose, which accident anchors are very liable toin hot climates. My anchor stocks will save a considerable quantity of the finest timber, and give much greater security. I likewise beg leave to offer to the Society a medel of a a ccitents law double fish hook, for the purpose of fishing the anchor, an »*= to happem : . ; : > “1 in fishing ane eperation-which, in the common mode of doing it, is fre- chor, quently attended with accidents both to the ship and crew, from the anchor suddenly slipping unexpectedly in raising it toits proper position. I flatter myself that these improvements will meet with the Society’s approbation. 2) I am, Sir, . Your most cbedient humble Servant; _ Lower Mitcham, H.L. BALL. Feb, 13, 1808. This anchor, in external appearance, differs very little phe anchow from the common anchor; the improvement consists in the described. forming and fixing of the shank of the anchor to the stock. The stock @ a, Pl. 1. igs, 6and 7, is made of two piecesof oak *bolted together, and well secured by hoops, In the com~ . mow 4$ Impro ved me- IMPROVEMENT IN ANCHORS: ' mon method, in order to prevent the, anchor stock ftom slipping off the shank, a square projection 6 6, fig. 8, is forged upon the shank; this is improved by Captain Ball, as shown in fig. 6, where this projection dd is extended on each side of the shank, far enough to receive two bolts through each of these extensions, which bolts hold firmly together the two pieces of timber that form the stock, and secure the stock fast to the shank. Two iron hoops, fig. 7, ee, are driven on the stock between the bolts, and ff ff are other hoops, and gg gg are treenails to strengthen the’ whole. Fig. 4, represents Captain Ball’s method of fishing an : thod of fishiD§ anchor. Fig. 5 shows an enlarged view of his double hooks the anchor, used for élite purpose. In the usual operation of Kenving an anchor, it is drawn up by the cable until it appears above water: the cable will not now raise it higher, it is therefore bowsed up by the cat block a, fig. 4, frora the cat head 6, the cable d being slackened out as it rises. When it is got up as high as the cat block will raise it, a strong hook, called the fish hook, » fastened te a rope ¢, which is suspended by a tackle from the shreuds, is hooked to the anchor at the bottom of the’ shank, and thus the arms of the anchor are elevated above the stock, until one of the flukes is brought up to the tim- ber heads ff, to which it is made fast by a rope and chain, called the shank painter. In this operation the fish hook sometimes slips and occasions mischief, tc remedy which, Captain Ball has applied two hooks instead of one, which: keep firmer hold. These hooks are shown upon an en- larged scale at gg fig. 5, attached to the rope e; each of these hooks takes one of the arms of the anchor, close to the shavk, and holds it firmly. 72 are two small lines made fast to the hooks, to direct them so as to get proper held ef the anchor. IX. Nicholsronir Lhitlos. Journal, Vol XXIV, P17, b.GE = ZA D : many, ar) ii Bu I milhed of. Qi | | Ay oh (bi cD = Z —————— Caf f ae Sif LO oot ZZ Liolb> td We Up wy Mask iH I my Hh MUN | | ; i Toni nf oved eC Soh OK, i] = i EXPERIMENTS ON CURRENTS, 49 ~ as IX. Observations on the Progress of Bodies floating in a Stream: with an Account of some Experiments made in the River Thames, with a View to discover a-Method for ascertain-~ ing the Direction of Currents. By Jamzs Burney, Esq. | , Havine frequently noticed, that the heavy craft on Heavy bodies the River Thames, - during a calm and without the -assist- Sth as ance of oars or of towing, made a progress faster than the than the cure stream of the tide on the surface, it led me to make inquiry "©" as well into the fact as concerning the cause, and gave rise to some experiments, which, with the ideas they suggested, are here set down; no otherwise according to method than being in the order they occurred, On questioning the men belonging to several barges, Laden barges which, unaided by wind, oar, or towing, were floating with ne faster than and overtaking the stream, they all agreed in the general gh fact, as a circumstance familiar to them. They said like- wise, that a laden barge made greater progress than a light barge; and this was corroborated by the evidence of the boats attached to them being drawn after them; for the barges overtook the moving water so fast as to have good steerage way. They attributed the difference in favour of a laden barge, to her having (as they expressed it) more hold of the tide than a light barge: by which it appears, that they supposed the stream of the tide was stronger un- derneath than on the surface. Adhesion to the atmosphere may retard the surface, except when the current of the atmosphere (the wind) goes in the same direction with the current of the tide; and then it may occasion an accelera- tion. Monday, July the 18th, I went on board a barge half This is notow- Jaden, which was floating down the river, but with steerage ing to 4 more : 5 rapid under way, between Putney and Chelsea bridges. I conjectured current, the rate of the tide to be a mile and a half per hour: there was a very light air of wind in a direction contrary to the . Vou. XXIV—SzEpr, 1809. E stream sO EXPERIMENTS ON CURRENTS. stream of the tide: but the barge, without any assistance of oars or towing, passed on, overtaking the stream, and her boat was towing astern. 1 fastened a riband to the end of a stick, and immersed it in. the water about 20 inches, which was as low as the lowest part of the barge’s bottom, and therefore sufficient to have shown, by the direction of the streamer, if the barge had been impelled forward by superior velocity of the under current, asin that case the streamer would have gone before the stick; but the streamer tended towards the stern, and was drawn after the stick: whence it wasevident, that the barge’s progress ex- ceeded that of the stream underneath as well as on the sur- face, and that this excess was acceleration produced by some other cause *. The surface of As by the general law of gravitation the heaviest bodies a stream an in- , r iadlyg mde ae ana : Sis oleut, descend with most velocity in a yielding medium, so it ap pears to be with bodies floating in a stream. The surface of a stream or current of water is not horizontal, but an inclined plane, and the inclination of the surface produces the current. Thus, when, by the attraction of the Sun or Moon, the sea is raised in some parts, it becomes depressed in others, and the water, seeking to regain its level, flows in a current from the superior parts. The barges on the river in a calm therefore slide down- ward with the stream, and also on it. Wherry out- A friend of mine in a wherry going to pass under Lon- oe by don bridge, being closely preceded by a coal barge, was apprehensive of receiving damage from collision with the barge when under the bridge; but the waterman said the barge would shoot far enough ahead when she came to the indraught of the arch. And it happened accordingly ; for Undercurrents * Na part of what is here said contradicts any received hypothesis produced by focal circum- stances, concerning under currents. Some under currents proceed from visible causes, as when the wind blows for a length of time in one direction. towards a coast, especially if it is an embayed coast, whereby the wa- ters are accumulated and the surface uear.the shore is raised above the general level, till the pressure of the increased weight forces back the water underneath. Under currents, where the causes are not visible, may be supposed to be caused by inequalities in the bottom, in the same manner as eddies are caused by the projecting points of a coast interrupting the general course of '& stream. the r EXPERIMENTS ON CURRENTS: 51 the barge, arriving first within the sterling heads, shot away from’ the wherry about 200 yards, by the superior momeén- tum she acquired i in the increased declivity. A pressure perpendicular to the horizon applied to a ho dy’ Perpendicu floating oa horizontal surface acts as increase of weight, 204 oPlia pressuy re acting haiti the effect only of making the body to which i€ is'ap- on a floating lar plied swim deeper, or'occupy more space in the water. Ani b°¢y- oblique pressure, not strong enough to submerge the body, affects it in two’ directions; one downwards in the manner of weight, to which the body yields to a certain and deii- nite extent; the other horizontal, 1n which direction the body continually gives way to the pressure. Almost every person has experienced the readiness of a boat to glide from under him, on putting his first foot in her. These two effects of an inclined pressure are separately in proportion te the whole pressure, one as the sine, the other as the cosine, of the angle of incidence is to radius. If to a body floating on a horizontal surface a pressure is Applied to a applied in a direction making with the horizon an angle of >@'g* 0m the 89° 59’, the proportion of the pressure which would act ho- hie rizontally is to the whole pressure, as the sine of 1’ is to radius. And this proportion is 752855 of the whole pres- sure. In like manner, if the-surface inclines 1’ from the true horizontal level, weight applied to a body floating on that surface will give an impulse towards the declining part of the surface equal to 75$$s0 of the weight applied. Cons: sequently, a barge having in her 100 tons weight, floating with the stream where the declivity of the surface is 1’, will receive an impulse towards the declining part of the surface equal to nearly 65lbs: which is little short of what is esti~ mated to be the average pull of a horse. , Hence it seems naturally to follow, that two pieces of auiectiow' ae wood, equal i in size but differing in weight, being placed in the course and the water near to each other, would show if there was a cur- Mane abe rent, by the heavier wood separating from the lighter in the direction of the stream. Likewise, that the quantity of se- paration in a given time might atford a measure for the strength of the current. And it is probable, that this would be found true in a smooth and equal running stream, where no paterreption was caused by the wind, Ee I sup- 5h Experiment with an oak & fir ball: with a staff loaded at one end, Passage of boats. through the arch ofa bridge. EXPERIMENTS ON CURRENTS. T supposed, that the best form to be given the wood for making the experiment would be globular, as being less lia~ ble than any other to be affected by irregularities in the surface of the water. I caused twa wooden ballsto be made, one of oak 6 inches in diameter, the other of fir, and not so large. I chose a time when the quietness of the-air was next to calm, and the surface of the water very smooth. The balls were put into the stream; the oak swam deep, Jeaving a very small portion uncovered; but the fir ball was found so very susceptible of motion from the lightest air of wind, that no conclusion could be obtained from this expe- riment. It was suggested by Mr. Rickman, my associate in these experiments, and whose observations jointly with my own have furnished this paper, that for showing the direction of the current, a long staff of light wood, loaded at one end, might better answer the purpose than two unconnected. floating bodies, because whenever it got out of the right die rection it would have a tendency to correct itself. On Wednesday, July 27th, we made some experiments on the river; but the weather was not favourable. Two sticks, one of them a common walking stick with a piece of lead fastened to one end, the other a hollow tube (a joint of a fishing rod) loaded internally at one end, were put into the stream (but not in any preconcerted or remarked direc. tion) and they both took the direction of the stream, the heaviest end becoming the most advanced. They were taken up, and being again put into the water in a direction oppo site to the stream, they gradually regained their former di- rection: in what time was not observed. In endeavouring again to repeat the experiment, two barges passing caused us to lose sight of our sticks, and we did not find them af- terwards. About an hour after the flood had made through London bridge, I noticed from the top of the bridge the passage of some of the craft. When any one drew near the arch, she did not keep pace with the water before her, so that on looking only at her head, she seemed to have stern way 3 but at her stern she left the marks of her track behind her. Two barges and a small boat, the small boat being in the - middle EXPERIMENTS ON CURRENTS, middle, at small and nearly equal intervals, followed each other through. That which first came to the increased fall under the arch, being precipitated, left the others far be-~ hind, till in their turn they were in like manner precipitated. When they arrived out of the rapid part of the stream into the smooth water, I did not observe, that their relative po- sition was altered from what it had been before they came to the bridge: but the small boat had made use of oars. It would answer other purposes than that of curiosity, to ascertain and form tables of the declivity of the surface at different velocities of current. The observations of alti- tudes at sea must be affected by currents, one part of the sensible horizon being higher than the other. A ship sta- tioned in a tide which runs one way North, the other South, may expect to find the observed latitude vary with the tide. In the afternoon of the same day that we made the expe- riment with the sticks (the 27th), we made a very imperfect attempt to discover what was the declivity of the surface above Westminster bridge, or rather:what angle the plane of the surface on the flood made with it on the ebb, by marking at two distant stations at the same times, the height of the water during the flowing, and likewise during the ebbing of the tide. One station was at one of the posts close under the Speaker’s garden: the other, on the same side of the river, at the ferry opposite Cumberland Gardens. The distance between the stations, according te the maps of London, is seven furlongs. At the post near the Speaker’s garden, the difference of the height of the river, taken at 4 P. M., the tide then flow- ing, and at 7 P.M., the tide ebbing, was 25°5 inches. At the ferry opposite Cumberland Gardens, the difference of the heights taken at the times above mentioned was 17°3 inches. | The tide was lower at 7 o’clock than at 4. "The stream at each of those times was running at a rate which we con- jectured to be nearly three miles per hour: therefore a greater variation was expected than 8°2 inches, which in a distance of 7 furlongs will give only 30” for the angular dif- ference between the plane of the surface on the flood, and 58 Altitude of the horizon differs ing with the tide. Attempt to ase certain the des clivity of the surface of the Thames, the . ‘54 Experiments with sticks less satisfactory than before, Long poles re- quisite at sea, Experiment with heavy wood a foot beneath the surface, ssialeaaiiili ON CURRENTS. the“plane on the ebb: so ‘that the angle of declivity Dstt the hor "yah levél, ‘supposing it equal each’ way, was not moré'than 15”. Perhaps’ the difference would have*been found greater, if the marks had heen taken'in mid stream, instead of close to the side of ihe river. The stoppage of Westminster bridge may likewise be supposed to occasion some swell in the part of the river Aigshandsg ies above i it} dur- ing.the ebb tide, doa On Wednesday, August the 3d, we again'tmade eu Abi. ments with sticks; which ‘proved less satisfactory than those we had before made. But, previous to describing farther operations, it is necessary to notice a consideration, »which, when it first occurred, seemed an insurmountable objéction to deriving any benefit from them. This was, the @reat dif- ference between the surface ina river, and the surface im an Open sea; so that an experiment, which might be found’ to succeed in the one, might scarcely. be at all practicable! in the other. ‘To this objection it is reasonable to answer, or at least a reasonable encouragement to expect, that if a small stick will point the direction of the stream m a river, a long pole (a steering sail boom, for instance), will, in cir- cumstances tolerably favourable, do so at sea. It’ seems within the rale of just proportion, that’a spar as large as a steering sail boom as much exceeds a walking stick, ‘as the irregularity of the surface at sea, in temperate weather; exceeds that of a river. In the experimenty ‘ows or more might be put into the sea at the same timey and if they agreed, there would be the greater reason for placing reliance on the result. Our next trial was with one of the Sonth Sea island clubs, of a wood not buoyant, about three feet in length, and gra- dually tapering. It was buoyed at each end with cork, but with string enough to let it be about a foot under the sur- face; and that the corks at each end might be equally ex- posed to the air, they were so managed as to show equally and similarly above water. There is reason, however, to think it would have been more proper to have allowed the proy exposure to the air at each end to be proportioned to the weight sustained. In the manner the experiment was made, the club, being left to itself in the stream, did not take’ or keep ‘ EXPERIMENTS ON CURRENTS. St keep to any determinate direction. It was unfavourable to this experiment, that the club was not of greater length, and, perhaps, that its weight at each end was in the same proportion to its size. We again tried with sticks loaded at one end. But the Sticks with one most that can be said of the results of this day’s experi- ©? loaded. ments is, that the loaded end evidently showed the most tendency to be downward with the stream. The sticks veered in their direétion more than we had observed in the former trials. This brought to recollection a circumstance, to which we had not paid attention. ‘The barges we had seen over-~ sliding the stream ina calm were kept in the right direction by their helm. Supposing a barge to be loaded at one end, and light at the other; without the help of the helm, the loaded end would probably not be found to keep her in the same direction with the stream, any more than the head sails only of a ship, being set, will, without the help of the helm, keep the ship before the wind. This consideration leads again to trials with two or more A hogshead & separate and unconnected bodies. An experiment which can 2 small keg might be tried at’sea, easily be made in a ship, is with a hogshead, which can be filled after it is put into the sea, and a quart keg, which if the air should be quite calm it would be sufficient to half fill. This would approach the proportion of a barge and her small boat: but as no guidance can be given, the most regu- lar shape (globular) seems the best. ‘The stream in the Thames above the bridges, from the Experiments ; unevenness and shallowness of the bottom, is unfavourable anism goo to experiments of the kind here recommended; and the su- “i ABS F ara perior convenience possessed by those whose constant occu- S Opporiunie pation is on the waters, who have opportunities, without an hour’s expense of time, to make experiments, which to other persons would cost days, have beep inducements to publish the inquiry in its present state, to give it the best chance of being prosecuted with any effect. S$ cf JAMES BURNEY. James Street, Westminster, | August 20th, 1808. a ® The 56 EXPERIMENTS ON CURRENTS. The above paper was read at a meeting of the Royal So~ ciety, February 16th, 1809. In consequence of some obser~ vations which it produced, the following remarks, in addition, were presented, and read at the Society. Weightimpels In a paper I had the honour to present to the Royal So- She SYRFATI Hr ciety, on’ the progress made by some bodies floating in a the body face stream, they descending faster than the stream itself, 1 en- oe deavoured to show, that this progress was the effect of per- pendicular pressure, producing impulse towards the declin- ing part of the surface. The same cause, indeed, evidently applies to the production of the stream itself; consequently the surface, and whatsoever floats on it, are, in this respects on an equal footing, and the whole agree in pressing for- ward and in opposing resistance to whatsoever endeavours to overtake them. Without some auxiliary cause, therefore, a floaiing body cannot overtake the stream. Shapeanddi- ‘The difcreut shapes of bodies, and likewise the directions rection of ain which they are placed with respect to the direction of the body affects its . 2 : velocity. . impelliag power, expose them to more or less resistance. A barge floating crossways to the stream receives the progres= sive impulse with the least advantage, her whole length act- ing ia resistance to her overtaking the stream. The same barge when endways with the stream, is acted upon by the sane quantity of impelling power, and her progress Is op~ posed by less resistance. Weight adds With increase of weight, both the impelling power and cals pee the resistance are increased : but when the barge is length- to the resist’ ways with the line of the stream, weight added will increase ances the impelling power in a greater proportion’'than the resist- ance is increased. Hence the heavy barge in a calm will overtake the light barge. This short explanation I beg to offer as an addition to my former remarks on the subject, and shall be glad if it assists in any satisfactory manner to account for vessels overtaking the stream in a calm. May W5th, 1809. NEW METHOD OF MEASURING A SHIP’s VELOCITY. 57 x. New Method proposed for measuring a Ship's Rate of Sail- ing. By the same Gentleman. A Line towing astern of a vessel, which is passing A line towed through the water, will pull against her head-way. As the adele per ship’s way increases, the pull of the line will increase; and petual log. vice versa. If this, with a proper scope of line (about 25 fathoms may probably be sufficient) shall be found to bea regulated quantity of pull corresponding in the same man- ner at all times to the rate of sailing, it will answer the pur- pose of alog. Many experiments have been made upon the same principle; but the most plain and easy one, of towing a measured length of line, has escaped trial; though less liable to give erroneous or variable results than any which can be made neara ship. By it, the rate of sailing may be obtained either constantly or occasionally, and can be taken with ease by one person: in which respect it would have great advantage over the common log, the use of which requires three persons. By a trial made in a boat with about 20 fathoms of line, Experiment. rather larger than log line, towing astern and fastened to a spring steelyard, the strength of the pull was found to vary with the rate of sailing, which however was not ascertained by measurement; but by estimation, the boat’s rate of sail- ing during the trial varied between 23 knots and 5 knots per hour, and the pull of the line upon the steelyards was ob-~ served to vary from 2lbs. to 5£\|bs.; increasing and de- ' creasing with the velocity. So great a variation in the strength of the pull gives all the advantage, which can be desired for forming a scale, and will allow of the experiment being made with smaller line. If the proposed length of line is passed through a pulley The velocity so as to vo clear out at the stern port or cabin window, and indicated by wees the inner end is fastened to a loose chain, of weight adapted to the purpose, on the deck under the pulley; or to a num- ber of small weights made consecutive by short intervals of line, the chain or weights will be drawn up more or less ac- cording 58 or a spring and ~ weights or a pulley, the inner end ofthe line (coming direct ladex. Objections, & answers to them, NOW METHOD OF MEASURING A SHIP'S VELOCITY. cording to the ship’s velocity. By a few comparisons of the quantity of weight raised from the deck with the rate of sailing, a scale may be marked. In an improved state of the experiment, instead of using from the water) can be fastened to a spring, and communi- eate with an index that shall express the rate of sailing. This machine (if so plain a contrivance deserve that namé) may be put on constant duty, or dropped occasionally to ascertain the rate. Objections which occur, are, Ist. The line being liable to contraction or expansion as the temperature of the water varies. But it is scarcely to be supposed, that the greatest contraction or expansion of line froin its mean state (after it has been properly stretched and seasoned) will occasion an alteration of a hundredth part yn the force of the pull. F 2d. That in a fresh wind the part of the line between the ship and the surface of the water, will be hable to some ad- ditional pull from being exposed to the wind. To this in- convenience, the log line in the common ‘way of heaving the log is likewise exposed when the wind is much aft. In either case, when the ship is not right before the wind, the remedy is the same: which is, to throw the log or the line over from. before the lee gangway, and to give a few fathoms more of stray line; for which however, in the new method proposed, it would be necessary to apply a correction, the quantity of which may be aceurately ascertained. 3d. The motion of a ship in pitching. But this is not to be regarded as an objection; for the rate of sailing is to be estimated ouly by what the experiment shows when the ship is going steadily; im the same manner as in taking bearings, if the compass swings, we wait till itis quiet. Whenever the ship goes steadily for ten seconds together, or even five seconds, the pull of the line will be regulated to the average yate of sailing. . “IMPROVEMENT IN DOORS. 59 XI. Method of preventing Doors from Dragging on Carpets, or _admitting~Air underneath them. By Mr. Joun Tav*, SIR, J Have taken ‘the liberty of laying before tie Society & Methodof pres ‘model of my invention to prevent doors from dragging on re ete, carpets, and to keep out the current of cold air, hich en- poe eee ters under such doors as are not close to the carpets under- on carpets, ‘neath them. I can affix this aii cng to the bottom of any door, so that'the door shall pass over the carpet with ease, and, when shut, be air tight. | It obviates the necessity of screw rising hinges, and is jess expensive than other inventions for the same purpose. i The machinery is constructed of a slip of well seasoned beech wood, equal in length to the width of the door; this slip is one inch and a quarter wide, and half an inch thick, ‘and to be covered with green cloth on the iuside; it is to ‘be hung to the bottom of the door with three smal! brass hinges, and is drawn up by a concealed spring as the door opens, and is forced down when the door shuts, by one end of it, which is semicircular, pressing upon a concave semi-~ circular piece of hard beech wood, fastened at the bottom of the door case;and which holds it down close to the floor or carpet, so as to exclude the air from entering under it. Hoping this invention will meet with the approbation of the Society, 1 remain, with respect, Sir, Your most humble Servant, ‘No. 4, Little Hermitage Street, JOHN TAD. Wapping, Nov. 24, 1807. A Certificate was received from Mr. William French, Cetifcate of No. 280, Wapping, stating, that John Tad had fixed. to its efficacy. two of his room doors the isadetion above mentioned, and * Trans. of the Society of Arts, vol. XX VI, p, 196. Five guineas were voted to Mr. Tad, for this communication,; that &0 The method described. IMPROVEMENT IN DOORS, that he found it to answer to his satisfaction, both in per- mitting the doors to pass clear of the carpets, and in keep- ing out the air. Mr, Tad’s invention consists in first eutting away the bottom of the door, so that it is about one inch and a quar- ter above the floor; this allows a sufficiency of reom for the doer to open over any carpet. To close the opening which would now be left under the door when shut, he pro- poses to fix beneath the door, by means of hinges, a slip of wood, of whicha b de, figs. 2 and 3, Plate II, is a sec= tion. Fig. 1 is a perspective view of the bottom of a door, with the invention annexed to it; fig. 2 is a section across the door when closed ; fig. 3 is a view of the edge of the door when open; and fig. 4 is a section supposed to be made by cutting the door in two parts, edgeways. The himges on which the slip turns, are fixed to the edge. In figs. 2 and 3, from a to b is exactly one inch and a quarter, so that when the ruler is turned down upon the hinges, it reaches the floor A A, as in fig. 2; in the other direction ad it ts much less, being only half an inch, so that when it 35 turned up under the door, as in fig. 3, it leaves three quarters of an inch clear of the floor. It now remains to show how the ruler is turned up or down; it has always a tendency to rise up into the state of fig. 3, by the action of a steel wire spring, shown in figs. 2 and 4, which is con- cealed in a rebate cut in the bottom of the door; one end of the wire is screwed fast to the door at f, the other is in- serted into an eye fastened into the slip at g. To throw it down into the position of figs. 2 and 4, the end 4, fig. 4, of the shp farthest from the hinges of the door, is cut into a semicircle, as seen in fig. 3. When the door is just closed, this semicircle is received into a fixed concave semi- circle k, fig. 3, cut in the end of a piece of wood k/, made fast to the door case; the line mJ, fig. 3, represents the plane of the door when shut, and p p part of the door seen edgeways ; as the door in shutting moves from p to m, the semicircular end of the slip a 6 de presses against the end of the piece & J, and as the door proceeds, it turns down as in fig. 2, so that by the time the door is shut, the slip is turned quite down; the edge e b of the slip is cut intoa segment IMPROVED SCREW-WRENCH. 61 segment of a circle struck from the hinges on which it turns. The perspective view in fig. 1 shows that this contrivance, applied to any door, will not offend the eye, as it can scarcely be distinguished from an ordinary door. Ky, fig. 1, shows the-concave semicircle of the piece of wood fastened to the doorcase, in which the semicircular end of the slip e is to be received. XII. Description of an improved Screw-wrench, to fit different sized Nuts, or Heads of Screws. By Mr. Wi.i.1aM Bar- Low*. SIR, Permir me to make a few observations on a shifting screw-wrench of my invention, which I beg leave to lay be- fore the Society of Arts &c. through the hands of Mr. Bru- _ nel, inventor of the block machinery here. , I have found, from long experience, the imperfections of Gogimon’ the various wrenches in common use, for the screw heads screw- wrenck and nuts of engines in general, which are often materially ‘heeumin injured for want of an instrument that would fit variety of. sizes, and be applied with as much advantage as a solid wrench. I have had it in view to unite steadiness with con- veniency in making such an instrument, and flattering myself that I have obtained both, I am desirous to com- ‘municate my invention to the Society, and have therefore sent an instrument on the principle I have actually used, and which has met with the approbation of my employers and other persons. This wrench, by means of a nut and screw, is adjusted |An improved} with the greatest ease to the exact size required, and in that "nc? state rendered so steady, that in use it is found equal to a, solid wrench. * Trans. of the Society of Arts, vol. XXvi, p, 199. Five guineas were voted to Mr, Barlow for this invention. I have 62 IMPROVED SCREW-WRENCH. ; I have, for several years, been intrusted with the care and repairs of many valuuble engines of various descriptions, composing the block machinery 1m. this dock-yard, and. I have always considered it as an object'of great importance, for the preservation and neat appearance of engines, to attend to all the means which would obtain these advan~ tages, and such, I think would arise from the use of my uni- versal wrench. . May be made _—It is, perhaps, unnecessary to point out, that a wrench on of varioussizes. this principle may be varied in its form and size so as to be rendered probably more convenient for some particular pur- poses for which such instruments are required. lam, Sir, a Your cbedient servant, Portsmouth Dock Yard, WM. BARLOW. March 1, 1808, The instru- This instrument is represented in PI. Il. Fig. 5 is a aa a perspective view of it; fig. 6 a section of its head; and fig’. 7 an external representation of the head. 'The screw head or nut to be turned is held between two jaws, one of which ab de is forged in the same piece with the handle A A, the other, fg, is moveable between two chukes, and fastened to the fixed jaw by the strong screw 2, which is fixed to the same jaw, passes through the moveable one, as shown in the section fig. 6, and has a nut screwed upon it; the other screw h, is tapped through the movable jaw, and its point presses upon the bottom of a cavity made in the fixed jaw shown at m in the section fig. 6. To make the wrench fit any particular screw head or nut, the nut upon the strong screw 2 must first be loosened, and the screw h screwed in or out of the movable jaw, until the opening bg is just the proper width to receive the screw head or nut to be turned by the wrench; the nut of the screw 2 is then to be screwed down, until it presses upon the jaw, and holds it perfectly tight. . XII. Meoholoon Lhilos. Journal, CLUE: 2 p. 6 Y ae Ra. t Gals Say Ou y, causing WZ Do ovihr OPCW Cor tf? OVELV Hq /. \ | : § afl a ZA i |) 9a | | ml Ht TH (Zi Sy “ | i | | MEASUREMENT OF HEIGHTS BY THE BAROMETER, 63 XII. On the Measurement of Heights by the Barometer. In a Letter from a Correspondent. ‘ To Mr. NICHOLSON. SIR, | July 17th, 1809. Tur method of finding heights by the barometer bids Finding fair to be of the greatest practical utility ; especially since Pee ee the impreved construction of portable barometers, and the great practical invention of more compendious modes of calculation than utility. those formerly in use, have considerably diminished the dif- ficulties, with which it was at first attended, It would be desirable, however, if the necessary caleula- Desirable to tions could be still farther simplified: for it must frequently ae ane poy happen, that observations of the heights of the barometer ther simplified. are made by travellers at times, when the mind, distracted by a variety of objects, or borne down by the fatigne of the body, may be ill calculated for even a moderate degree of exertion. For this purpose the following tables have been calcu- lated, which, with little more than the mere trouble of in- spection, will give the result true to the nearest foot. They may be printed on the surface of a common card, so that their bulk cannot be the least inconvenience to a traveller. ‘Table 1. Contains altitudes in feet answering to every te of the fol- tenth of an inch of the height of the barometer from 25 to lowing tables. 31 inches. | Table 2. Contains the proportional parts to be deducted : for every additional hundredth of an inch, corresponding to the heights of the barometer marked in the first co- Jumn. Hence to find the approximate elevation of one station alvove another, nothing more is necessary, than to find from Tables 1 and 2 the elevations corresponding to the ob- served heights of the barometer, and subtract the less from the greater. It. would not be difficult to construct tables, which should give G4 MEASUREMENT OF HEIGHTS BY THE BAROMETER, give the result by mere inspection: but unless they should be continued to every hundredth of an inch (in which case they would make a volume) the trouble of subtraction is all that would be saved. Table 3. Gives the correction for the expansion of air for every 1000 feet of altitude. It is calculated for every decree of the mean temperature from 72 to 32. It is pro- bable that few observations will be made in this island, where the mean temperature is not within these limits. This table is calculated from Table 5, p. 484, of Gregory’s Mechanics, vol. 1. With regard to the correction for the expansion of the mercury, it may be obtained without any sensible errour, by multiplying the difference of temperature im degrees of Fahrenheit by 2°75 tors or 2 feet 9 inches. Yours, &c. J. i TABLE Tf. ' TABLE II. Bar.) Byun iba ncaneyBaa wee B. 25°0 | 5606 | 27-0 | 3600 | 29°0 | 1738 era ai -1{5502| +1] 3504] -1 | 1648 vy ree -g!5398 | -2| 3408! +2! 1559 ie m7: -3|5995| °3| 3313]. +3| 1470 pee Gere 415192} 4] 3217| -4| 1381 8 Pir 515090! 5! 31221 +51 1993 6 {4988 | 6] 3028] -6| 1205 wg (ag -7 | 4886 -7 | 2034 “7 1 4117 aay a *§ | 4785 "8 | 2840 *8.1 1029 ar ied 9 | 4684} -9| 2746] +9] 942 erica 1 96:0 | 4584 | 28°0 | 2653 | 30-0} 855 ; pes 114483} ‘1lo559| <1! 768 ba fags .g|4ss4| -2| 2467] -2| 6s1 a 8 arte 3 | 4285 | +3 }9375 | 3 | 595 Pane aa 414186! -4|9983t +41 509 ane “5 5 | 4087 “5 OO ch oie pA, Siatashosicve 6 | 3989 | 6 | 2100 | 6 | 338 ‘gal | 713891 | +7! e009! 71° 953 asc nna -g18794{ -g|1918| <8} 169 5 Pe *9 | 3697 | 28°9 | 1828 9 | 84 “tty les SLAUBERITE, A NEW MINERAL. 6§ niu teed emit Yo steer PA BEB! IT Th, Gor, ). Th..,Cor., Lh. Cot, 126 | 59 | 68 45, 32 721101 } 53} 65 | 44} 29 711 98 | 57} 62} 43 | 27 70 | 96 | 56} 60} 42 | 24 : 69 | 93 | 55157141} 22 -|68} 91454] 54] 40] 19 67 | 88} 53.4 52) 39} 17 66} ° 86} 52/4) ] 38] 14 65 | 83 151} 47] 37} 12 64}. 80] 50] 44} 36] lo 4163 | 78) 49).42135| 7 62} 75148)394,34} 5 61 g3 47|.37| 83] 2 60}; 70] 40|34|32] — XIV. ~ On the Glauberite. By Avexanpur Brocwrart*. "Tue form of the glauberite is that of an oblique prism, Figure of the greatly depressed, and with a rhombic base. The angles of Lane the parallelogram of the base are 76° and 104°. The anion © of incidence between the parallelogram of the base and “the adjacent sides’ are 142°. That between the base and the edge contiguous to the acute angle of the base is 154°. The faces of the base are generally plane, smooth, and even shining: those of the sides on the contrary are full of stria, parallel to the edges of the base. Very evident junctures parallel to the base are discoverable by cleaving; as are others not so well defined, parallel to the edges of the base, and inclined to the former in angles of about 104°. These observations give as the primitive form of this crys« Primitive form. tal an oblique prism with a rhombic base. The crystals are nearly limpid, or of a topaz yellow, and Colour. retain their solidity and transparency in the air, if they have not. been wetted. * Journal de Physique, vol, LXVI, p. 235. Vou. XXIV—Sepr. 1909. F Their 66 GLAUBERITE, A NEW MINERAL. Hardness. Their hardness exceeds that of sulphate of lime, but is ins ferior to that of carbonate of lime. Actionof fire. Exposed to the fire, the glauberite splits, decrepitates, and melts into a white enamel. Singularaction Immersed in water, its surface becomes of a milky white, _ echt and in a little time the whole of the crystal grows com- pletely white and opake. Tak en out of the water and dried, it does not resume its transparehcy, but the white coating falls to powder ; and, if it be entirely removed, the encleue’t is discovered remaining unaltered, It is the only mineral substance that possesses this property. Spec. grav. The specific gravity of the glauberite is 2°73. Givctals re This salt, the crystals of which at first sight bear some sembling it. resemblance to those of axinite, and the fragments of which are a little like those of sulphate of lime, differs essentially from the latter, whether anhydrous or possessing its water of crystallization, in its primitive form,, and in the second ary forms derived from it. ts component Jt is composed of anhydrous sulphate of lime «+++ 49 cae anhydrous sulphate of soda -+++ 5% ; 100 No wales, Mr. Brongniart satisfied himself, that #t contained no water, not only by several calcinations at the temperature nearly of melting silver, but also by distilling it after Mr. Berthollet’s manner with iron filings, when he could obtain no hidrogen gas. Sulphate of He ascertained the presence of the sulphate of soda by soda, solution and crystallization, which afforded him well de« fined crystals of this sulphate. andoflime. . The sulphate of lime he found by decekayptiiie this galt both by carbonate of ammonia and oxalate of ammo- nia, No loss. As he had no loss, but what cannot be avoided in he mical operations conducted with the greatest care, and this loss did not amount to one per cent, he presumes, that this: stone contains no other pondetable miatter essential to it but the two salts mentioned above : and to-be more certhin of this, he examined carefully, whether. it; contained no any _ » phosphates, EXCELLEN'?, COPAL VARNISH. 67 phosphates, borates, or muriates, which might have been ‘suspected from'thesituation where it was found. The glauberite was brought from Spain by Mr. Du- where founda, meril, It has hitherto been found only at Villarubia, near Ocanna, in-new Castile. Its crystals are sometimes soli. tary, sometimes in clusters, and disseminated in masses of sal gem. Mr. Brongniart bas not been able to find any tention of this mineral; either in the works of minera- logists, or in those of stich in Spain, that he could ris ig | | ne: ae XY. An excellent colourless ‘Copal Varnish. By Mr. Lenor- “MAND, late Professor of Natural Philosophy*. Every one knows the difficulty of dissolving copal com- Copal difficuls pletely, when we attémpt to make a varnish, I hasten theres °f solutien: fore to communicate a method, that has succeeded perfectly with me; and which will be found, to produce a very fine varnish with this substance. » All copal isnot fit. for making this varnish, it must there- Method of se fore be selected with cares, and-the following method will lecting it, show what is good. Take. each piece of copal separately, and let fall on it a single drop of very pure essential oil of rosemary, not altered by keeping. Those pieces on which the oil makes a certain ‘ith pression, that is to say, which ‘soften at the part. that imbibes the oil, are good, and should “be reserved for making varnish, The others are to be re- jected. = ai Powder the pieces of copal thus selected, sift the powder and of making through : a very fi fing hair sieve, and put it into a glass, on the the vamish,. ' bottom ‘of which it must not lie more than a finger’s breadth , thick. On it pour essence of rosemary to a similar height, stir ‘the whole tocether with a stick for a few minutes, the ‘copal will dissolve into a viscous substance, and the whole will form a very thick fluid. Let it stand for a couple of hours, after which pour on gently two or three drops of ¥ : « Sonnini’s ‘Ribliothéque Physica-€conomique for 1808, Vol. If, wees. ¥9 tery 68 Uses of the varnish. French na- tional Insti- tute, Question for a double prize. SCIENTIFIE NEWS. very pure alcohol, which you will distribute over the oily mass by inclining the glass in different directions with .« very gentle motion. In this way you will effect their incor- poration. Repeat this operation by little and little, till the varnish is reduced to a proper degree of fluidity. Remem- ber, the first drops of aleohol are the most difficult, and re- quire the longeft time to incorporate; and that the difficulty: diminishes as each successive addition is imcorporated, or aa the mass approaches the state of saturation. When the varnish has attamed the suitable degree of fluidity, it is to be suffered to stand a few days; and when it has become very clear, the varnish isto be decanted off. | > The magma that remains at the bottom may still be rendered useful,. by. pouring on alcohol in the manner directed above; but care must be taken, to add oes little at a time. i This varnish is made without heat, is very clear. and co- lourless, may be applied with equal success on pasteboard, wood, and metals, and may be worked and polished, with ease, indeed better than any known varnish. It may be used on paintings, and singularly heightens their beauty. SCIENTIFIC NEWS. oo French N. ational Institute. ‘Tue public sitting of the Mathematical and Physical Class for 1809 was held on the 2nd of January. A double prize had been offered for a ‘* Theory of the perturbations of the planet Pallas, discovered by Dr. Olbers : or in gene- ral the theory of planets, the excentricity and inclination of which are too considerable for their perturbations to. be cal- culated with sufficient precision by the known methods.” Not to enter into any thing shore than is indispensable, on such a difficult subject, nothing: was required farther than algebraic formule, but so arranged, that an intelligent cale culator might apply them secunelys and. without mistake, ‘either to the planet Pallas, or to any other already « discovers - ed, or that may be discovered hereafter. Notwithstanding these pipiens: no paper haying been sent, the subject is ~ still SCLENTIFIC NEWS, 69 enll left open till the ist of October, 1810. ‘The prize isa medal of the value of 6000 francs [£250]. The ordinary prize subject for next year is: ‘* To exa- Another prize mine whether there be any circulation in the animals knowr question. by the names of asteriz, echini, and bolothurie; and, if there be, to describe its course and orgaus.”” The description must be accompanied with observations made on living ani- mals, and include the vessels of the respiratory organs, if there be any such, as well as those of the principal circula- tion, To examine the chemical effect of the respiration on the air and water, would be a desirable adition, but this is not absolutely insisted en. The examination of one species ef each family only is required; but it is expected to be by no means superficial, and accompanied with drawings, so that the principal details: may easily be verified. The prize is 3000 francs [£125], and the term as abov . ; The history of the mathematical division of the class of Mathematical physical and mathematical sciences exhibits this year a sin- S!4** gular circumstance; one of the most difficult and most im- portant peints of the solar system treated with equal success, though after different methods, by two geometricians of the first rank ; to both of whom the investigation was suggested by an ie esting paper read to the class by a young geome- trician. Astronomers had remarked a perceptible accelera+ Prablem whe tion in the course of the moon: consequently other planets, ‘her the pla- and among them the Earth, must have a similar accelera- “faite tion. If the motion of the Earth be accelerated, it must celeration. be owing to its approaching the centre of motion: and, if it do, will it not ultimately fall into the sun? The danger of this indeed must be infinitely remote, for the acceleration is extemely slow; and it appears from the instance of the moon, that the acceleration continues but for a time, and is afterward changed into retardation. Still however the ques- tion is particularly interesting to astronomers, who in all their calculations suppose the unchangeableness of the ellipses described by the planets. Mr. Laplace first examined this question, and-found by ,,. Saat stew, a learned but merely approximate calculation, that the mean ed they have anotions and axes are really invariable; at least taking inta se a Wig ximate cal . consideration only the first powers of the masses, and the culations second 70 which La grange extend. 3 and Poisson has carried still farther, History of the sciences. Discoveries in * - which Mr. Davy led the way, and which have been pursued chemistry. Minerals ex- posed to great heat under pressure contain cr ys- tals not fused. Lamination of zinc, and its extrac- tien froin the ore. Acetic acid F:om wood, SCIENTIFIC NEWS. second of the eccentricities and) inclinations, Mr.’ Lae grange, struck with this conclusion, endeavoured to extend it; and proved by a curious theorem, that the proposition was true, considering even all'the successive powers of the eccentricities. But what would be the result, were the masses considered in terms of two dimensions ? This inquiry demanded great labour, and no less acumen : yet Mr. Pois- sou undertook it, and demonstrated, that, if any accelera- tion exist, it can only depend on terms of four, six, or eight dimensions, and of course must be altogether imperceptible. As soon as Mr. Poisson had demoustrated his theorem, Mr, Lagrange and Mr. Laplace perceived, that it naturally flow ed from principles aud methods they had formerly laid down: in cougequence they were both led to demonstrate the-proposition more generally, but each in a different way. The physical division of the class presented to the em- peror a sketch of the history of the sciences from the ‘year 1789, which will soon be -published. The principal discoveries in chemical science are those to in France chiefly by Messrs. Gay-Lussac and Thenard. The experiments of Sir James Hail too have been repeat- ed by Mr. Dree.. Having exposed to fusion in close ves- sels, under irresistible pressure, fragments of rocks with trap or chert for their base, he found, that they assumed all the appearance of ;stony lavas; and that the crystals.of feld- spar in them were not altered, which explains the singular fact of so many very fusible crystals contained in lavas, that have rendered it questionable whether these lavas had ever been in a state of fusion. i - The invention of the art of laminating zinc by heating it is claimed for the late Macquer and Mr, Sage, who practised it long ago: and Messrs. Dony and Poncelet, of the de- partinent of the Ourthe, have converted calamine simply by subliming it into metal sufficiently pure to be laminable. The ore affords them one third its weight of metal, whichis much cheaper than lead. | Another successful application of chemistry to the arts is that of procuring from wood an acetic acid as pure as radi- eal yinegar, the manufacture of which has been carried on some SCIENTIFIC NEWS: 71 gome time by Mr. Mollerat. It answers extremely well for aromatic vinegar 5 ; but possesses a little acrimony, on account of which it is not quite so fit for the table. The wood dis« tilled for this purpose yields as much charcoal as in the ors dinary way, and a great deal of tar. In consequence of the interruption between France and Grape sugar, the West Indies Mr. Proust and Mr. Parmentier have taken great pains to improve the extraction of sugar from grapes*. - Mr. Morveau has given a history of attempts to con- Pyrometer, struct instruments to measure high degrees of heat, in which he does Wedgwood more justice, than he has generally re- ceiyed i in France. He afterward describes an instrument of his own invention sufficiently delicate to indicate changes in a metallic bar that do not exceed a thirteenth thousandth part | of its length, Such a bar of platina is the only thing sufficiently dilatable, and at the same time unalterable by fire, to serve properly for a pyrometer; but the difficulty is to place it ona scale, that will not dilate. This Mr. de Morveau hopes soon to accomplish. _ Mr. Gay-Lussac has just explored a beautiful law of Se Law respect- neral chemistry on the proportion of metal, that enters ie ing the propor to each metallic salt, and that of oxigen necessary for its — ls ae oxidation. He bas shown, that a metal, which precipitates metallic saltse another from an acid solution, finds in the metal precipi- tated all the oxigen necessary for it to become oxided, and dissolve in such a quantity, that the solution shall be neu- ‘tralized to the same degree. The quantity of oxigen re- mains constant, whatever be the proportion necessary to ‘each metal : and the acid in each salt is proportionate to the oxigen of the oxide, and requires so much more metal to saturate it, in proportion as the metal requires less oxigen for its oxidation. This law affords a yery simple method of determining the composition of all ‘metallic salts; for it is sufficient to know the proportion of acid in one salt of each genus, to be acquaiuted with all; anda single analysis will allow us to dispense with the rest. Mr. Darcet jun. has shown, that soda and potash, P!€- Soda and po- ‘pared with alcohel and heated to the point at which they toate cannot be mv reed from wa- * See Journal, vol. XXI, p, 306, and 341, begin 7% Animal mucus and uree. Structure of the brain and nervous sys- tem, Analogy of structure in animals. Coats of the nerves com po- sed of nervous filaments. Mirbel, SCIENTIFIC NEWS. begin to evaporate, notwithstanding still retain wide a vaca of their weight of water. _ Messrs. Fourcroy and Vauquelin have presented two im- portant memoirs, one on animal mucus, the other on uree, Among the anatomical subjects, that have engaged the attention of the class, few are so interesting as the memoir on the structure of the bram and nervous system by Drs. Gall and Spurzhem of Vienna. Accosding to these gen= tlernen, the cinereous or cortical substance is the organ, from which issue the nervous filaments, that consti(ute the white medullary substance. Wherever the cinereous substance exists, some of these filaments originate; and wherever any of these filaments commence, this substance will be found. The spinal marrow is not a bundle of nerves descending from the brain: on the contrary the nerves termed cerebral may be traced to the medulla obiongata or spinalis; and the brain and cerebellum themselves are but developements of tasciculi from the medulla oblongata, in the same man- ner as the nerves come from it. The committee have found almost all the anatomical observations of Drs. G. and S, agreeable to nature: but they think it proper to add, that this has no connection whatever with’ Dr. Gall’s theory. of the appropriation of different part of the brain to the difs ferent functions of the mind. Prof. Duméril has considered in new points of view the bones and muscles of the trunk in man and various animals, The graud principle he seeks to establish is, that nature is as uniform as possible in her means, continuing the sdme through numerous varieties, as long as they are effective, and never adding a new organ, unless when new circum- stances reguire greater efforts and more powerful means. Mr. Villars of Strasburg, has presented two papers on the structure of the nerves. He thinks he has perceived, by means of the microscope, that the covering of the nerves is itself composed of nervous filaments: but the committee, notwithstanding they have taken great pains to ascertain this, could not satisfy themselves of the fact. The anatomy of plants is indebted for many new and — important facts to the researches of Mr. Mirbel. The Royal Saget of Gottingen, having made this anatomy. a subs SCIENTIFIC NEWS. 7% a subject of one of its annual prizes, has occasioned the publication of several tracts, the principal ef which are those of Link, Treviranus, and Rudolph, all professors in different German universities, Agreeing in most facts with contradicted ia Mirbel, they not only add some observations to his, but Some De ‘contradict him on certain points; which has induced him to publish a defence of his theory, in which he gives it more has defended precision, exhibiting it in the form of aphorisms; while he his theory. endeavours to show, that most of the objections arise from his having been misunderstood, or his observations not hay-~ ing been repeated with sufficient care. : Mr. Mirbel has likewise presented to the class two pa- ‘pers, one on the germination of the family of grasses, the other on the distinguishing characteristics of the monocoty= Jedonous and dicotyledonous plants. In the first he shows, that the stigmata of wheat unite Germination in a small canal, which reaches to the base of the embryo; ° 8'#ss¢s- and that the cotyledon, as Jussieu thought, is a fleshy sub- stance, in which the radicle and plumula are imperceptibly developed, and which opens lengthways to let them pass, so that it performs the office of a vaginating leaf. From the second it appears, that the cotyledons have Cotyledons great analogy to the leaves, those of the sensitive plant be- se eae ing irritable, of the borages hairy, &c.; in short, they are true leaves in the seed. i, when there are two cotyledons, they appear opposite in plants the leaves of which are alter- nate, it is because the stalk cannot develope itself in the seed, and the interval between the cotyledons is not to be distinguished, From the different perceptible analogies be- . tween them, Mr. M. infers, that the number of the coty- ledons must refer to some circumstance respecting the leaves; and he imagines, that the monocotyledonous plants Monocotylee are uniformly those, the leaves of which ensheath each donous plants. other. Proceeding to examine the formation of the wood, Wood, Mr. M. shows, that it is always composed of filaments in- terspersed in a cellular texture resembling the medulla of the dicotyledons; but that in many of the monocotyledons these filaments are formed at the circumference as well as jn the centre: the latter in consequence having a double vegetation ; one at the circumference, increasing the dia- meter 74 SCIENTIFIC NEWS. meter of the trunk; the other at the centre augmenting its density. He considers each of the filaments of the trunk of the monacotyledons as if it answered to an entire trunk of adicotyledon ; and shows, that in each of these filaments a series of operations takes place as complete as in those trunks. | Mirbel elected Mr. Mirbel, in consequence of his various labours toward tothe Institute. j]instrating the physiology of plants, was elected to the place vacant by ‘the death of Mr. Ventenat. Deeandollehis The competitor of Mr. Mirbel for the vacancy in the In< competitor. stitute was Mr. Decandolle, who, beside his previous titles Plants with to it, had sent the class early 1 in the year a work on plants = with compound flowers, in which he makes a separate fa- mily of those the florets of which have two unequal lips, and distributes those termed cinerocephalous according to the lateral or terminal insertion of the seed. It was feet however, that his talents would be more useful in the cele~ brated school, in which he teaches botany, and at the head of the fine gardeu under his care, in a climate more fayour- able to the vegetation of foreign plants than the vicinity of Paris. Botany much This sitting showed in general, that botany is cultivated Subyates m in France with more ardour than ever. The Memoir on r the Family of Orchidee, by Mr. du Petit Thouars, a spe- cimen of a greater work on the natural families of plants, with those of Mr. de Longchamp on Narcissusses, Mr. Jaume St. Hilaire on the Orobanches, and Mr. de Cubiéres on the Lote trees, and the Monography of Eringums by Mr. de la Roche, are proofs of this. Developement. Mr. du Petit Thouars m particular has deter car to efthe bud. publish his Theory of Vegetation, founded on the develope- ment of the bud in two directions, which was noticed in our former report, vol. XXIII, p. 315. New family of | Mr. Ventenat himself terminated his laborious career by plants, ° a paper ou the Genera Samyda and Casearia, of which he makes 2 new jamily next to that of the rhamnoides. This . Jardin de Cels, piece was mtended for the continuation of the Jardin de Cels, a work interrupted by his death. He lived long enough to carry to some extent, though not to finish, his Garden of Male Description of the Garden of Malmaison, which no doubt echime will be continued by some other hand. The SCIENTIFIC NEWS, a5 The history of animals has witnessed. the completion of Olivier’s Cole Mr. Olivier’s grand work on coleopterous insects, and is en- aan finish- riched with a description of all the gelatinous animals in- eluded under the name of medusa is Linneus. Mr. Péron, Meduse. who collected a great number in his voyage to the south, has increased this family to more than a hundred and fifty Species. The following is his account of their singularities, ** Their substance seems to be merely a coagulated water, yet the most important functions of life ave exercised in it. Their multiplication is prodigious, yet we know nothing of the peculiar mode in which it is effected, They are capable of attaining several feet in diameter, and fifty or sixty pounds in weight, yet their nutritive system escapes our eyes. They execute the most rapid and long continued movements, yet the details of their muscular system are imperceptible, They have a very active species of respira- tion, the true seat of which is a mystery. They appear extremely feeble, yet fish of considerable size form their daily prey, and dissolve in a few moments in their sto- mach, Many species of them shine amid the darkness of night like balls of fire; and some sting or benumb the hand that touches them: yet the principles and agents of both these properties remain to be discovered.” All the medusas have a gelatinous body, nearly resem- bling the cap of a mushroom, which Mr. P., after the ex- ample of Spallanzani, names umbrella; but they differ in Specific cha wanting or having a mouth; in the mouth being simple or ¢‘'s- multiplicious; in the presence or absence of a production resembling a pedicle; and in the edges of this pedicle, or of the mouth itself, being furnished with tentacula, or fila~ ments more or less numerous. From these characters Mr. P. forms divisions and subdivisions, under which every pos- sible kind of medusa may be arranged. Very fine paint- ings by Mr. Lesueur, who accompanied him on the voyage, illustrate the various forms and colours of these auimals, “many of which are very pleasing to the eye. To this examination of their external characters, Mr. P. Their interior has added very interesting remarks on the interior structure Sucture- _ of these animals; and in particular of that genus, which Mr. Cuvier named rhizostome, because he supposed, that the Skeletons of animals found to the earth. Bones ofalarge monitor lizard, 26 feet long. SCIENTIFIC NEWS. the filaments bordering its tentacula were so many suckers; and that the nourishment drawn in by them was received: into a central cavity, whence it was distributed to the whole body by an infinite number of vessels disposed with great regularity, and particularly numerous about the edges of the umbrella. The four apertures at the sides of the base of the pedicle appeared to Mr. Cuvier to be the organs of respiration. Mr. P. on the contrary, having seen many liv- ing rhizostomes take in small animals by these four aper- tures, and digest them in the four.cavities to which they Jead, presumes that they are four mouths, and as many sto= machs; while the great vascular apparatus, that fills the pedicle and the borders of the umbrella, is more probably appropriated to respiration, as it is almost always found, fulb of air, Mr. Cuvier read a paper on certain reptiles, the skele~ tons of which are found in strata of our globe. These had all been taken for crocodiles, and even for the species com- mon in the Ganges, the gavial; but the lacerta monitor i also among them, and those that most resemble the gawial have striking characteristics to distinguish them. All of them are found in strata much deeper, and consequently more ancient, than those that contain bones of land quad- rupeds. The environs of Maestricht conceal the bones of a large animal of this family, which some have taken for a crocodile, others for a fish. Mr. C. attempted to show, that this also was a lacerta monitor, but it is the giant of its kind. It measures in length upward of eight metres [26 feet]. ts tail, much shorter in proportion, but broader, than that of other species, formed a powerful oar; and An inhabitant eVery thing renders it probable, that it had sufficient of the sea. Foassile bones from America, strength, and was so good a swimmer, as to live amid the waves of the ocean. Its bones too are found with those of large sea turtle, and among thousands of sea shells. My. Jefferson, President of the United States, has sent the class a fine collection of fossil bones dug up on the banks of the Ohio. The greater number belong to the Jarge animal improperly called mammoth by the Americans, and to which Mr. Cuvier has given the name of mastodente: but there are lilcewise some belonging to the true mammoth of SCIENTIFIC NEW2-: . oF ef the Russians, or the other large animal, much reseme bling the Indian elephant, the remains of which are so common in Siberia. These two gigantic creatures therefore formerly inhabited together all the northern cap of our globe. The destruction of these enormous races, and of s0 many others, victims of the same catastrophe, cannot be explained, till we are well acquainted with the strata in which they are buried, as well as their nature and succes- sion. Mr. Cuvier and Mr. Brongniart have endeavoured to Strata in the study these in the neighbourhood of Paris. As far as they some ae have been able to penetrate into the earth round that. capi- tal, they have found :t composed of various strata evidently of different origin. The lowest part is a vast mass of chalk, that reaches to England, and contains nothing but unknown shells, several of which belong even to uwknown genera. On this chalk rests a bed of potter’s clay, containing no organized body. This in several places is covered by lime« stone, the hardest of which is used for building, and which is full of shells, most of them of unknown species, but of known genera, or approaching nearer than the preceding to those that live in our present seas. Hills of gypsum are scattered as if by accident sometimes on the clay, at others on the limestone, and contain thousands of bones of land animals entirely unknown, of which Mr. Cuvier has put to- gether the skeletons, and established the characters. In this gypsum, and the clay intermixed with’ it, or immedi- ately covering it, there are no sheils ‘but fresh water ones: but these are afterward covered with thick strata of sea shells. A vast bed of sand, without any organized bodies, crowns all our heights; and, what is most remarkable -of all, the most superficial stratum, that which covers the whole, is mixed with fresh water shells alone. It is only in the bottoms of valleys, or in cavities hollowed out of this su- perficial stratum, that are found the bones of elephants and other animals, the genus of which is known, but not the species. From the Sass of these gentlemen it appears, The land there that the sea, having long covered this country, and several set Sellen ae times changed its nature and inhabitants, gave place to terward with fresh 78 SCIENTIFIC NEWS. fresh water, fresh water, in which these gypsums were deposited; but andonce or that it returned at least once to cover the land it had aban= ear “is doned, and destroy the beings that had lived on it. On this occasion perished the paleotheria and the anoplotheria. Every thing renders it probable however, that it returned a second time, and that the elephants disappeared 1m this se= cond catastrophe. . Petrifaction. Mr. Sage presented to the class a ferruginous petrifaction, having some appearance of a bundle of tobacco leaves tied round with threads, but probably part of a stalk of bamboo, or some other jointed plant. He likewise gave descriptions and analyses of a few ftones; and communicated some ex- periments on the cohesion lime contracts with various sub stances. ‘Transition Mr. Brochant, mine engineer, presented some observa- arene tions on strata much more ancient than those in the vicinity of Paris, which Werner has called transition strata, because they are placed between the primitive mountains, anterior to all organization, and the secondary strata, that abound with remains of animals. Most of them are composed of fragments of the primitive rocks, united into breccias by cements of various kinds, in which we begin to perceive oc- casionally remains of organized substances, either vegetable or animal. Saussure had already noticed these in the Alps. Alps, but Mr. 5B. has traced them to much greater extent, principally along that side of the Alps which leoks toward France. @limateof ~° Mr. Lescallier has shown, that the climate of Liguria is | Genoa. more favourable to the plants of hot countries, than any other in the same latitude: the winter, though longer, not being so cold, because the Apennines shictids it from the north wind ; while the summer is less scorching, from the Vicinity of the sea on one hand, and the snows on the other. Department of ° My. Girod-Chantrans has given the natural history of nt. ae department of the Doubs. - Albumen a Mr. Seguin, who formerly found gelatine the true wilde remedy against against intermittent fevers*, has this year tried albumen Intermiltents.” ~ it with good success. He has already cured forty-one patients, by giving them the whites of three eggs diluted with warm * See Journal, vol. VI, p. 138, and XIII, p. 205, water, SCIENTIFIC NEWSs« 79 water, and sweetened with sugar, just before the fit comes ban. He says this convenience attends both these remediés, if the fit that follows the first dose be not mitigated, you must not expect a cure from them; if it be, perseverance in them will succeed}. Messrs. Cels, Tessier, and Huzard, have drawn up a code of rural scheme for a Code of Rural Law, the object of which is to laws. protect landed property from every imaginable injury. it is transmitted to aselect committee in every department for éxamiiation. Mr. Tessier has drawn up, by order of government, po- Culivation of pular instructions for the cultivation of cottonin France. cotton in Mr. Bose has described twenty-eight species of the ash, France. half of which, though cultivated in the gardens and nur- S¥perior spe- series round Paris, have not been noticed by naturalifts. + aacaa Some of them are large trees, superior in elasticity and flex- ibility to the common ash. St. Thomas’s and Guy's Hospitals. The Winter Courses of Lectures at these adjoining Hos- Lectures pitals will commence as usual, the beginning of October. Viz. At St. Thomas's. Anatomy and the Operations of Surgery. By Mr. Cuine at St. Tho- and Mr. Cooprr. mas’sy Principles and Practice of Surgery. By Mr. Cooper. ( At Guy's. Practice of Medicine. By Dr. Basineton and Dr. Guy's, Curry. Chemistry. By Dr. Bapinetron, Dr. Marcet, and Mr. ALLEN. , Experimental Philosophy. By Mr. ALLEN. Theory of Medicine, and Materia Medica. By Dr. Curry and Dr. CHoLMELEY. . Midwifery, and Diseases of Women and Children. By Dr. Hareuton. | ome Physiology, or Laws of the Animal Giconomy. By Dr. Harcuron. . Structure and Diseases of the Teeth. By Mr. Fox. N.B. These several Leg¢tures are so arranged, that no two of them interfere in the hours of attendance ; and the whole is calculated to form a Complete Course of Medical and Chi- rurgical Instructions. ‘Terms and other particulars may be dearnt at the respective Hospitals. . fas fae eel London Hospital. eT Dr. Buxron’s Autumnal course of Lectures on the The- and the Lon.’ ory and Practice of Medicine will commence on ‘the 2d of 40" Hospital. | October at the Medical Theatre. 4+ Have we not here a clew to the presumed success of such apparently inert remedies? C. f METEOROLOGICAL JOURNAL, For AUGUST, 1809, Kept by ROBERT BANCKS, Mathematical Instrument Maker, in the Stranp, Lonpon. “spade ee uama JULY] oi} 3 [oe ah aes a} 1gAalee ¢ Day of! 2 | a |ool=Z} 9A. M. alat=hs 26 ,62}64170161) 29°75 27 1631661} 69{6L} 29°73 28 | 62159165) 551 29°64 29 $59}58}64}58} 29°73 30 | 60| 59} 64] 56} 29°60 31 $| 58158166457 | 29°55 AUG. 1 61162| 66157} 29°66 9 |60/62| 66/60} 29°72 3 1|60|57 | 62) 51) 29°40 4° 733155) 59 SRT. 20t4d § 153/58 | 61) 57 -* 2O76 6 161159 | 63 | 55'1' (29°38 7 158159164156) 29°65 3 163/64} 68) 58} 29°94 9 | 64)/65|71} 58} 29°94 10 |62170/ 74|60} 29°89 21 .LG1 161 | 73 (700.12) 20'08 19° 163 157 | 68° 591% 20°67 13 (64163168160) 29°79 14. + 64163 | 69758}. 29°80 15 161161163. 58" 2875 16 161/63 167;}60} 29°88 17. |63:|64176158} 29°84 728. |60/61(71)591. 29°78 19 {63|}611681/571} 29°80 20 |61/61}661}56} 29°96 21. | 60|58 164152} 29°84 22. | 58] 57 | 67 | 52] 29°84 23. {591 57.| 67 | 50} 29:62 24 158/561 64148! 29:49 25 155' 50° 631482 29°43 * Thunder, lightning, and rain in the evening, the moon bright at intervats, 4 Rainy and cold, almost the whole day. \ { Thunder, lightuing, and rain in the night. Sultry mor ning. WEATHER. Day. Night. Rain Cloudy* Fair Ditto Raia Fair Ditto Rain Ditto Fair Fair Ditto Ditto Cloudy Dittu Ditto Rain OFair 1" Ditto + Cloudy Ditto Rain Ditto Ditto _ Ditto Fair Fair — Ditto Ditto Ditto Ditto | Cloudy ¢ Ditto Fair Rain Ditto Ditto Ditto Ditto Ditto Ditto Cloudy Ditto Fair Fair § Ditto |] Rain J Ditto Ditto Ditto Ditto. — Ditto Ditto Ditto Ditto Ditto Fair o Rain Bute Ditto * Ditto || Lightning in the East, at 11 P.M. very dark aud appearance of rain. - @ Heavy rain in the morning. * Thunder, at 1 and 3 P.M. ee ee < JOURNAL Or NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. — ——————————— OCTOBER, 1809. ARTICLE I. Further Application of a Series to the Correction of the Height of the Barometer. To Mr. NICHOLSON. SiR, . Iw calculating a table of the depression of the mereury in Continuation the tube of a barometer, produced by the effect of capillary ae former s@ attraetion, I have found it necessary to determine a greater number of the coefficients of the series published in your ‘ twenty-second volume, p. 213. The value of f is found v Q1 b? He 529 b$ 163 63» b és 140° + Sm 1920m* | 57000m: | 3680400 mt "0% 8 385 59 if I have computed correctly, is equal to 42 5°? + ee 129721 b7 _983b bF 5197 h3 b 69120 m™ | 24040 m>? | 33177000 m* | 530841600 m>" _ Here it may be observed, that the numerical coefficients of Vou. XXIV. No. 107.—Ocr. 1809. G the 82 CORRECTION OF THE HEIGHT OF THE BAROMETER. , Y 3 2. 6 1 the highest powers of & form this series, —, —, Pm 40 ) 2°93 8 KA? 6. r a, which may be continued at pleasure, and which must obviously express the versed sine of a circular arc, since, when 6 becomes infinite, the curve coimcides with a circle, and the highest powers of 6 must in this case be in- finitely greater than all the rest: the coefficients of the : : ‘ 1 10 owers of 6 next in order form this series, ——, ——~ P 7 a OG? 10.14 70 “Aish toners jae oa 5.6. 3 1010p ee, Tages eremee ee those of the other orders of terms seem to follow a law nearly similar, but which I have not fully ascertained. The coefficients of the terms iucluding the lowest powers of 6 are however of more consequence; the progression of the coeficients of 6b is sufficiently obvious: these of b* have their denominators increased according to the same law, and the ratio of the numerators approximates to 8, and dif- fers so little from it, that this number may be employed as a multiplier without sensible errour: aud in a similar man- ner if the denominators of the coefficients of b° are made to increase in the same ratio, the numerators approach nearer and nearer to the ratio of 16 to 1, which is probably their ultimate proportion: and in some instances the conti~ nuation of the progressions on these principles is required for a sufficiently accurate determination of the quantities concerned. Arrangement For calculating the de gataiost or elevation of a fluid ina of the series. tube of a given diameter, it is convenient to arrange the series according to the:powers of 6; so that the whele as- sumes this form, 2 = i + 000 002 712 67 —5 x he + 000 000 000 134 557 a. CORRECTION OF THE HEIGHT OF THE BAROMETER. (Qmex 4 925 x° gh + -010 4167 — m gy? + °000 217014 nm 9 1Z 4 +000 006 022 605 6 =~ m 13 ws -++ -000 000 000 000 600 8 mn yt? -+- :000 000 000 000 002 os6 mn? w*? -+- ‘060 000 000 000 000 0058 ay m ew) 6 + (:25 27 + (:5 x9 x9 ; xi 4 "109 375 — Gi each yu at mm m 13 + -003 047 49 a + *022 960 1 Fl +. 000 245 00? —— m + -000 014 402 — 4 +000 000 69? = of . -) oF Bis ns) 0° a coe yb eel VLA + (°166 667 x5 | + 2 +...) 09 + (°1°167 x** 13 034 722 2 m x ‘003 559 03 —; m r "000 011 887 m 2 "000 000 399 6 — m i ‘000 000011 1 —— x ‘000 000 000 247 — ™m 7 12 x "000 235 822 — ™m 13 15 17 m 19 of Sar Bio oy. 83 The value of 4 being determined by the solution of this Expansion. equation for any given tube, of which the semidiameter is . G2 Le CORRECTION OF THE HEIGHT OF THE BAROMETER. x, that of y may be found from the original series, which may be thus expanded, y=(4m + 2 at + :0625 — ™m x? + 00173611—, - . “ ™ x? + '000 027 1267 — | | 7 10 x -+ °000 000 271 267 a his m 1z x -++ 000 000 001 abit Fd + +000 000 000 009 611 21 — carn + 000 000 000 000 037 54 —> x78 -+- :000 000 000 000 000 115 9 GP m 290 x + *000 900 000 090 600 000 29 x2? + +000 000 000 000 000 000 000 6 nie 2 Se pitt x 2 en tA RA ow UL | 18 + +035 5903 —; m x? +- "002 829 86 — 2 Z at m* : 14 ; PI 1000 006 393 4-——— F 1000 006 393 4- + +000 156 642 + °Q08 €ORRECTION OF THE HEIGHT OF THE BAROMETER. 85 16 x -+ -000 000 200 — E m x8 “fe ‘000 000 004 904 =e ) vp 20 ‘++ *000 000 000 10 ee m 23 + 1000 000 000 0016 ~,- j mt + eee ) b? ++ (2 2° + (5 2° a? yi? yt? a + °275 514 oat + 1°87675 = iz ; 4-042 665-—~ Rah Oy oF m x4 -+ -003 920? aC ++ (14 27° xis ; yt + 000 261? a + 16:04167 Th zi? ee : + -000 0137? —~ +...) 42? + 7000 000 55 ? — Aare Deh hes aaa t * + -000 000 018 2? oy + ye In this manner the following table has been calculated, Table of the m being still made :005, and n = :00375; and it may in seesnicg of general be considered as accurate to the last place of the decimals laid down: the depression is also deterinined ac- cording to the experiments of Mr. Gay Lussac, in which m appeared to be :0051, n being still 00375. In applying the correction to a given barometer, the bore might be as- certained by measuring the difference of the central and marginal depressions with a micrometer, and comparing it- with this table, without the trouble of emptying the tube. Diameter 86 Flevation of water. CORRECTION OF THE HEIGHT OF THE BAROMETER. Central depression. Marginal Aa ——-\ depression. Observer by EET Ld, GG, 1. ene coo m=='005 m=a="0051 Dineen Difference. 1:00 "00031 *00082 “90 ‘00060 ‘N00002 °S0 “OO11S “OOLIS “70 *00220 "00224 } “60 “00411 00416 “005 0637 °0506 "50 “00799 "00805 "007 -0076 "0596 "45 "01100 *01106 *0090 0580 *40 01516 01522 “015 0714 "0562 °35 *02093 *02098 "025 "0745 "0536 *30 "02902 *62906 036 0787 "0497 *95 "04064 *04067 *050 ‘0850 "0444 29 ~~ °05800 "05802 *007 “0066 "0386 “15 °08620 *08621 "092 "1171 «= 0309 *10 °14027 *14027 *140 "1019 0216 "05 "29407 "20407 *3060 ‘0110 When it is required to continue the curve till it becomes perpendicular to the absciss, it is evident that the series cannot be sufficiently accurate, since in this case the least imaginable increase of the absciss would afiord an impossi- ble value for the ordinate. It is therefore convenient to compute the value of 5 and y fora portion of the curve a little less than that which is required, and to determine the length of the remainder from its mean curvature, deduced from the magnitude of the ordinate, together with that of the absciss. For example, if it be required to find the cen= tral and marginal elevation of the surface of water contained in tubes 1 inch, 4, and £ of an inch in diameter, taking m = ‘01; we may continue the curve till its inclination to j fd n the horizon becomes 60°, and — = '866; but we must first m determine the corresponding diminution of the diameter, ‘im order to obtain the value of x For this purpose the part of the curve which is nearly vertical may be compared with , a cubical parabola, the distance of which from its tangent is to, the versed sine of the osculating circle, as the distance froin. the vertex, diminished by one third of the tangent, to the whole distance. In the first example, taking the mar- ginal elevation by conjecture +15, we must deduct '02, the height corresponding to the horizontal curvature, of which. the CORRECTION OF THE AEIGHT OF THE BAROMETER. the radius is °5, and to find the mean radius of the arc of 30°, we have 2s (°13—#5) ='01, ss—26s=—- ‘OL s—°13— ‘0009 = ‘0463: but the versed sine of the are of which this is the sine, in the circle of curvature at the ver- tical point, is °01552, which is to be diminished 10 the ratio of “13 — 0154 to "13, and becomes °01371; and deducting this from «5, we have °4863 for the value of x, when n = “00866. Hence we find 6 = °0948, a= :0088, and the marginal elevation *151, which is so wear the assumed value, that no further correction is required. In.the same manner, for tubes of 4 and 3 inch in diameter, we find a = *0374, and +130, and the marginal elevation ‘162 and 220 respec- tively. But it would be rather more accurate to compute the extent of a portion of the curve, somewhat greater than 60°, by means of the series. We may also obtain a series, in a manner nearly similar, for determining the relation of the arc to the absciss aud ‘the ordinate ; and such a series must represeat the proper- ties of the curve in a more general manner, and may, in gome cases, be more convenient for calculation, at the same time that it affords a mode of verifying the results which we have already obtained. Taking the expres sion fx yx f(x? + 5°) = mx j, we may put #* + 77 = 27, xazt+A “steal Mawr oh atopic death el He 2 Ed c2*t+dz* dy cas fb eivoe aoe ; but = =146 Az + 0B +9 4%) 24 + Gc . 30 A B) 2° + (18 D + 424 C + 25 BY) oe aaa aioe 16 6 c2* + (246d + 16 c”) 2° + (82be+ 48 ed) 24.5.5 whence, by comparing the homologous terms, A = — 2 b*, —6bc—92A . —24bd—160cc—30AB eee eS Oe Rime st end 10 14 , —39be —48ed—A2AC—25 BB ’ and D = ro eT a ie oa a - Again, for the fluent fx y%, we have ry = az + (a.A + B) 2 +(aBtbA+teo2e+...,%=24+3A2724+5B Ps Saale and fxyi =a + (aA +6+43 Aa) a 87 Series in terms of the are, $8 CORRECTION OF THE HEIGHT OF THE BAROMETER, 4 6 ~ + @B+bA+c43A (A+ 1) 4+5Ba) = em «+», which must be equal to mx ll or to 2mb 2% +- z (4me+2mbA)2*+ (Gmd+4mcecA+2mbB) 2x 4 ...3 whence 6 = —-, c= oe 1° Sees 4m 16 m add ee eo AS 24mcA—i12mbB i ia ae eu ek te Se ee , by reduction, ¢ = 5 3? tee pds Oe Vame ania g ~ 576 m* -. 45m 45° ~ 36864m% 26880 m? 99 $5 b7 2 4 sas — Se ee aaa : eye Biba A bry and D= arn 672 m* 35m 315 207360 m* OSHS hit flr + haath Here we may observe, that 453600 m? 70m 2835 in the series for finding the value of y, the coefficients of the terms involving the lowest powers of 5 are the same as in the former case, and that there is a similar approxima- tion to the ratios of 8 and 16 in the neighbouring terms, so that we may safely continue the series on these foundations: the coefficients of the highest powers may be uty by this ogre ie é s é E which, or ssion pes ag), Aes Ve! Gain, Ce. ‘ for the reason already mentioned, must ech the versed sine of a circular arc. In the series for a, the coefficients : r Dee ys D, Sy go of the first terms form this progression; —, — . —, e ; Je By 5 «hee are Soe ee To ° 4 9 e 123 . AZ . % e > 11 194 ° 43 a ° 6 _-? e 3 g 3 5 Fi 9 11 9g I g ke ig gh Sais eae 8 AS" OF ee ee 18.°°123> A) SE 2D 7 Sita A old 2 3.5 2,939.3 % 0.03 , Pia ga: CORRECTION OF THE HEIGHT OF THE BAROMETER. &9 ey aD 9 Dis Doh foe eae pee 405 18 809.3 52.9.8.4.9.9.393,4.5 g —-——: and these of the last terms are ——s eee. SoA BP. 6 3 2 4 9 4 A 9 4 4 4 TRS RS Need Sinem tre 2 ey Sean Seed e. 5: 6.7 § “4.5 28 17 VB Vo wo. \ 93 Qs Qi? aioe > » , : and this series must obviously “ila ee ee represent the sine of a cireular arc, since ail the other terms vanish in comparison with these, when 6 becomes infinite. _ These series however have not the convenience of afford- Inconveni- ing a fluent divisible by x the absciss, as in the former case, ©” and the expression for the inclination ef the curve is much . less convergent: it may however be employed where great accuracy is. not required. Since fxry% = nx, we find, a : } y n from the first equation, nxz = mxy, and — =~, con- & m sequently = SV th ——, and the relation of z and 6 may be determined from either of the series, when x and x are given. The series themselves may be thus ex- panded. xz -++(°183333 25 4-007 054.67 29 4® Expansion of of the series. —(-666667 23 +057 14929 EL. i ; vt ~5 9 = ¢ z 2? — 000 256 533 ‘10 — ‘010 — BRA mt ay ee p08 2a Cee ese; 27 + :00744048 — ep alicuhO + -000 006 577 77 ~ ais bi? “9 z sae + °000 337577 —3 —(012 698 4 27 soe IE i9 z Z 4 '000 010 357 5 —>.+ -014 285 7 — 4 m mm 4...) 0 +...) 6 > y= (4m 90 Other parts of the curve. -+ 000 027 1267 =, : m CeRRECTION OF THE HEIGHT OF THE BAROMETER. y=(4m —(°33333 24 a 6 a ‘ r4 7 A ‘088 889 ce + +0625 a oe 28 6 ™ m” A + -001736 11 —; ™m Io *000 S91" : pels m* 1z z m* -+ +000 000 271 267 ~~ ; m ie °000 002 02 — ++... as above) db i m°> 16 +(-044 444 2° “000 080 063 ie + ti "8 10 + 000 049 48 = ns 4 + ri ab + °030 258 — sid m "000 0:0 001 6 —; Mm Bia + 7008 4528 —~ ant m "000 000 090 031 — 21% Mt + -001 30? — Ab ae) BF ee 003-174 62%, + 090 130 7 + 2 i Mm z& ua -+ °006 031 7 4 e Far haeonee + 7000 009? —, ee is aa Sh + 70014109 2°°++ ...) 0° + :000042 755 277 +...) 6" ++ °000 0009344z"* 4. ...)6"%+ *000 000015 57 2°°4...) b% | anti The same mode of investigation may be applied to the more accurate determination of the properties of the curve at any other point of its extent; substituting r—ay for z, q—y fory, and p—f[(r7—x). (q—y) #] for the fluent : but the calculations become considerably complicated. Thus, if we suppose z to begin where the curve is vertical, 3 ¢ 2 z 36 mg b°—oOr 14 6 m 576 mrb—72m 2 14 2 23 m” r b* — 144 m? 6 b 2z* ——_—. ab vee, and y= z— 56% 29+ 7 m ——— Piveet CORRECTION OF THE HEIGHT OF THE BAROMETER. 4+ ...: or, if we express # in the powers of y, x= by* + 2by* 3q+ Q4mb- rising in a tube an inch in diameter, g being *151, and b= .. For example, in the case of water / 1 : | om Poa 6°55, we have, for an arc of 30°, Sin. 30° = 2m Oe i “5 = 13°1 z— 502” — 145°6 z*, whence z = ‘05, or perhaps "0505, x = ‘0161, and y = 0483. But for this value of y, x ought to be but about :0153: and this difference, as well as the numbers obtained from the properties of the cubic parabola, shows only that it would be better to ex- tend the calculation to an arc of 70° or 80° by the first se- ries, if great accuracy were required. According to Mr. Gay-Lussac’s experiments, m is more correctly, in the case of water °0115; in that of pure alcohol :0047. For a surface of simple curvature, the primary equation Surface of sim’ is fy & f(x + 9°) = my, and the coefficients of the first pre Cun cline F a series become b = om? o= hee & m er) and d = 2 & +- e 11 3? b é 1 : the ratios of the last terms being 30m + 360m? "5.6m oe and so forth: andzu=ibae?+}ex°+1dxr4+...: and from this series we may calculate the elevation of a fluid between two plane surfaces. I am, Sir, Your very obedient servant, 3 Sept. 1809. | E. F.G. ii. §2 ACTION OF POTASSIUM ON SALTS AND OXIDES. Il. On the Action of the Metal of Potash on Metallic Salts and Oxides, and on Alkaline and Earthy Salts. By Messrs. THENARD and Gay-Lussac*. Muriatic acid Convincep by a number of experiments, that it was not obtainable dep not possible to obtain muriatic acid free from every other substance, we attempted to make the metal of potash act directly on muriates, in order to ascertain whether this acid would nat by these means undergo some alteration. Muriate of ba- For this purpose we took muriate of barytes fused ata rytes exposed ; , 5 , : teats Sig se pi red heat. We had powdered it, and introduced it into a potassium, tube of glass blown by the lamp, into which we had previ- ously put a small ball of the metal; but no action took No action place, either cold or at a red heat; the metal passed through took place. the salt without any perceptible alteration, and on throwing it into water, after the refrigeration of the matter, it In= Other alkaline flamed very vividly. Other alkaline muriates did not afford twee of US more satisfactory results. We then subjected’ to the silverand mer- same trial, in the same way, insoluble metallic muriates, as ea ey the muriate of silver, and mild muriate of mercury. tassui, Scarcely was the heat greater than sufficed to fuse the me- tal, when a very vivid inflammation was excited, and these two salts were reduced. In both reductions the tube was broken ; and in that of the muriate of mercury, there was something like a slight detonation owing to the mercurial wut theacid vapour. In both cases nothing was formed but muriate of not decom- j : cect : : He - potash, and no sign of the muriatic acid being decomposed was observed. Examination Having no farther hope of finding a mean of decomposing at aeaoutiys of muriatic acid in experiments of this kind, we attempted to hapa ae ascertain the action of the metal of potash on other salts, oi ox and on the metallic oxides, continuing to employ the same ; method of operating as before. In all our experiments the heat was constantly a little hiyher than was necessary to fuse ' the metal. Sometimes, as far as the decomposition of phos- * Journal de Physique, January, 1809, p. 103. phate ACTION OF ROTASSIUM ON SALTS AND OXIDES. phate of lime, sulphate of barytes, oxide of zinc, &c. it was carried to near 300° of the centigrade thermometer [572° F’.]. The tubes we used were always brekea, when the inflain- mation was very vivid. To avoid minutize, we fhall confine ourselves to the results we observed. Sulphate of barytes. Decomposed without any inflam- mation, and sulphate of barytes obtained. Sulphite of barytes. Vivid inflammation, and‘ sulphu- ret of barytes formed. From these two experiments we fhould infer, that the oxigen is much less condensed in the sulphite, than in the suiphate of barytes; and very probably also less condensed in sulphurous acid, than in sulphuric. Sulphite of lime. Slight inflammation: formation of a very yellow sulphuret. Sulphate of lead. Very vivid inflammation. Sulphate of mercury but little oxided. with the mild muriate. Nitrate of barytes. jection of the matter. Nitrate of potash. Destruction of the metal without in- flammation ; which is owing, no doubt, to the nitre contain- ing water. Superoxigenized muriates. Phosphate of lime. of inflammation : production of phosphuret of lime. Carbonate of lime. tion: charcoal set free, Chromate of lead. Vivid inflammation. _ Chromate of mercury. Became slightly redhot : the mass changed green, . _ Arseniate of cobalt. Vivid inflammation. Green and yellow tungstic acid. Vivid inflammation. Red oxide of mercury. Very vivid inflammation : slight detonation owing to mercurial vapour. Oxide of silver. Very vivid inflammation. — Brown oxide of lead. Like the preceding. Red oxide of lead. Vivid inflammation. Yellow oxide of lead, The same. Inflammation as Very vivid inflammation, and pro- Very vivid inflammation: Decomposition without appearance Decomposition without inflamina- Yellow 93 On sulphate of, barytes ; sulphite of barytes, and of lime; sulphate of lead, and of mercue TY 3 nitrate of ba- ryles, and of potash g oximuriates$ phosphate of lime, and carbonate; chromate ef lead, and of mers’ cury 5 arseniate of coba't; oxides ef tung- sten, mercury, silver, lead, 94 eopper, arsenic, cobalt, antimony, tiny manganese, bismuth, zinc, nickel, and chrome, Pyrophorus. Action of po- tassiuin on earths. Siliceous flu- orice gas. Decomposes all substances containing oxigen, and indicates bts condensa- tion. ACTION OF POTASSIUM ON SALTS AND OXIDES, Yellow and brown oxides of copper. Vivid inflammation White oxide of arsenic. Inflammation. Black oxide of cobalt. Like the preceding, Volatile oxide ef antimony. Inflammation, but less vivid than with the oxides of copper. Oxide of antimony at a maximum. Very vivid inflame mation. Oxide of tin at a maximum. Very vivid inflammation. Putty of tin. Inflammation, but less vivid than the pre« ceding. . Red oxide of iron. Very slight imflammation. Black oxide. No inflammation, but reduction of the iron. Oxides of manganese at a maximum. Very vividinflam- | metion. Oxide ata minimum. No mflammation. Yellow oxide of bismuth. Vivid inflammation. White oxide of zinc. Reduction without inflammation. Gray oxide of nickel. Pretty vivid inflammation. Green oxide of chrome. No inflammation: production of a blackish matter, which, when completely cooled, and afterward exposed to the air, takes fire as an excellent pyro~- phorus, and becomes yellow. This matter is a combination of potash and oxide of chrome, which in the air changes to chromate of potash. We likewise tried the action of the metal of potash on earths, and particularly on zircon, silex, yttria, and barytes, and found, that it was evidently altered by all these ; but as we clo not yet well know the cause of this alteration, we shall not here enter into any particulars respecting it. We fhall only say, it appears to us very probable, that the phe- nomena observed in burning the metal of potash in silicious fluoric gas are in no respect owing to the silex. Be thi is as it may, it follows i. all the preceding frets, that every substance, in which the presence of oxigen is hitherto known, is decomposed by the metal of potash: that almost all these decompositions take place with extrication of light and heat; that more is disengaged in proportion as the oxigen is less condensed ; and that consequently they afford ANALYTICAL EXPERIMENTS ON MURIATIC ACID. 95 afford means of estimating the degree of condensation of oxigen in each substance. ‘8 These experiments, having occupied a great deal of time, Boracic acid have prevented us from continuing those we had begun on Neg saati ‘ ; z ' ... bya mixture boracic acid. Yet we had already learned, that this acid is of charcoal and capable of being decomposed at a very high temperature Mel. by a mixture of charcoal with iron or platina, and forming borurets: for Mr. Descotils, on exposing such mixtures to a forge fire, has obtained metallic buttons, which, treated with nitromuriatic acid, yielded him very evident quantities of boracie acid; and which, from our experiments on the nature of the boracic acid, could be nothing but a combina- tion of bore, platina, and iron. III. The Bakertan Lecture. An Account of some new analytical Researches on the Nature of certain Bodies, §c. By Humpury Davy, E£sq., Sec. R.S., F.R.S. Ed., and M. RI. A. . (Concluded from page 24.) 8. Analytical Experiments on Muriatic Acid. I Have made a greater number of experiments upon this numerous ex- substance, than upon any of the other subjects of research periments _ that have been mentioned; it will be impossible to give any nae cae Tae more than a general view of them within the limits of the Bakerian lecture. Researches carried on some years ago, and which are de= yryriatic acid tailed in the Journals of the Royal Institution, showed, that gas contains there were little hopes of decomposing muriatic acid, in its sacral common form, by Voltaic electricity. When aqueous so- lution of muriatic acid is acted upon, the water alone is de- composed ; and the Voltaic electrization of the gas affords no indications of its decomposition; and merely seems to show, that this elastic fluid centains much more water than has been usually suspected *. I have already laid before the Society an account of some experiments made on the action of potassium on muriatic * See p, 31. : acide 96 ANALYTICAL EXPERIMENTS ON MURIATIC ACID. 2 acid. I have since carried on the same processes on a larger scale, but with precisely similar results. Jis'action en When potassium is introduced into muriatic acid gas, potassium, —_ procured from wmuriate of ammonia and concentrated sul- , phuric acid, and freed from as much moifture as muriate of limeis capable of attracting from it, it immediately becomes covered with a white crust, it heats spontaneously, and by the assistance of a lamp acquires in some parts the temperature of ignition, but does not inflame. When the potassium and the gas are in proper proportions, they both entirely disap~ pear; a white salt is formed, and a quantity of pure hidror gen gas evolved, which equals about one third of the origi- nal volume of the gas. S ers. of potas- By eight grains of potassium employed in this way, I ef- si bsorb 22 : 5 : co lee ale of feéted the absorption of nearly twenty-two cubical inches of the gas. muriatic acid gas; and the quantity of hidrogen gas pro- duced was equal to more than eight cubical inches. Hidrogen’ The correspondence between the quantity of hidrogen eet re tee generated in cases of this kind, and by the action of potas- same propot- “ ‘tion as if water sium upon water; combined with the effeéts of ignited char- had been used. Coa} ypon muriatic acid gas, by which a quantity of inflam- mable gas is produced equal to more than one third of its volume; seemed to fhow, that the phenomena merely de- pended upon moisture combined with the muriatic acid gas*. Farther proof, | Todetermine this point with more certainty however, and lieabatke to ascertain whether or no the appearance of the hidrogen decumposed, was wholly uaconneéted with the decomposition of the acid, I made two comparative experiments on the quantity of muriate of silver furnifbed by two equal quantities of murir atic acid, one of which had been converted into muriate of potath by the action of potassium, and the other, of which had been absorbed by water; every care was taken to avoid gel sain * When the Voltaic spark: is taken continuously. by means of points SER arabic vas of charcoal in muriatic acid gas over mercury, muriate of mercury is ra- averimercury. pidly formed, a volume of inflammable gas, equai to one third of the ori- ginal volume of the muriatic acid gas appears, and the acid gas enters inte conibination with the oxide of mercury, so that water enough is present in the experiment to form oxide sufficient to absorb the whole of the acid. ; : Sources ANALYTICAL EXPERIMENTS ON MURIATIC ACID. OF sources of errour; and it was found, that there was no nota- ble difference in the weight of the results. There was no proof then, that the muriatic acid had been Muriatic acid decompounded in these experiments ; and there was every oi) eae reason to consider it as containing in its common aeriform weight of wa- state at leaft one third of its weight in water; and this con- a clusion we fhall find warranted by facts, which are imme- diately to follow. I now made a number of experiments, with the hopes of Attempts to obtaining the muriatic acid free from water. = by EN I first heated to whiteness, in a well luted porcelain retort, het ca de ue a mixture of dry sulphate of iron, and muriate of lime which lime distilled had been previoufly ignited; but a few cubic inches of gas Wari _ tag only were obtained, though the mixture was in the quantity : of several ounces; and this gas contained sulphureous acid. I heated dry muriate of lime, mixed both with phosphoric phosphoric glass and dry boracic acid, in tubes of porcelain, and of iron, os and employed the blaft of an excellent forge; but by neither of these methods was any gas obtained, though when a little moisture was added to the mixtures, muriatic acid was deve- loped in such quantities, as almoft to produce explofions. The fuming muriate of tin, the Kquor of Libavius, is Muriate of tin known to ‘contain dry muriatic acid. I attempted to sepa- Aes fk rate the acid from this fubftance, by diftilling it with sul- phosphorus. phur end with phosphorus; but without success. I obtain- ed only triple compounds, in phyfical characters something like the solutions of phosphorus and sulphur in oil, which were nonconductors of electricity, which did not redden dry litmus paper, and which evolved muriatic acid gas with great violence, heat, and ebullition, on the contact of water. I distilled mixtures of corrosive sublimate and sulphur, Muriates of _ and of calomel and sulphur. When these were used in their coir ag common states, muriatic acid gas was evolved; but when sulphur, they were dried by a gentle heat, the quantity was exceed- ingly diminished, and the little gas that was generated gave hidrogen by the action of potassium. During the distilla- tion of corrosive sublimate and sulphur, a very small quan- tity of a limpid fluid passed over. When examined by transmitted light, it appeared yellowish green. It emitted fumes of muriatic acid, did not redden dry litmus paper, Vor. XXITV—Ocrorer, 1809. H and 98 and with phos phorus, Phosphorus burned in oxi- muriatic acid gas. A white sub- stance sublim- ed, and a fluid formed, No muriatic acid gas form- ed. ANALYTICAL EXPERIMENTS ON MURIATIC ACID. and deposited sulphur by the action of water. Iam im- clined to consider it as a modification of the substance dis- covered by Dr. Thomson, in bis experiments on the action of oximtiriatic acid on sulphur. Messrs. Guy-Lussac and Thenard have mentioned*, that they endeavoured to procure dry muriatic acid by distilling a mixture of calomel and phosphorus, and that they obtain- ed a fluid, which they consider as a compound of muriatie acid, phosphorus, and oxigen. In distilling corrosive subli- mate with phosphorus, I had a similar-result, and I obtain- ed the substance in much larger quantities than by the dis- tillation of phosphorus with calomel. ° As oximuriatic acid-is shightly soluble in water, there was reason to suppose reciprocally, that water muft be slightly soluble in this gas; [ endeavoured therefore to procure dry muriatic acid, by absorbing the oxigen from oximuriatic acid gas by substances, which, when oxigenated, produce compounds possessing a ftrong afhinty for water. Phos- phorus, it is well known, burns in oximuriatic acid gas; though the results of this combuiiion, I believe, have never been minutely examined. With the hopes. of procuriug muriatic acid gas free from moisture, I made the experi- ment. I introduced phosphorus into a receiver having a step-cock, which bad been exhauited, and admitted oxi- muriatic acid gas. As soon as the retort was full, the phos- phorus entered into combustion, throwing forth pale white flames. A white sublimate collected in .the top of the re- tort, and a fluid as limpid as water trickled down the sides of the neck. The gas seemed to be entirely absorbed, for when the stop-cock was opened, a frefh quantity of oxi- muriatic acid, nearly as much as would have filled the retort, entered. The same phenomenon of inflammation again took place, with similar results. Oximuriatic acid gas was admitted till the wile of the phosphorus was consumed, Minute experiments proved, that no gaseous muriatic acid had been evolved in this operation, and the muriatic acid was consequently to be looked for either in the white subli- _¥ The Monitcur before quoted, mate, ANALYTICAL EXPERIMENTS ON MURIATIC ACID3 99 mate, or in the fluid which had formed in the neck of the retort. The sublimate was in large portions, the fluid only in the quantity of a few drops. I collected by different processes sufficient of both for examination. The sublimate emitted fumes of mumiatic acid when ex- properties of posed to air. When brought into contact with water, it evol- the sublimate, ved muriatic acid gas, and left phosphoric acid, and muriatie acid, dissolved in the water. It was a nonconductor of clec- tricity, and did not burn when heated ; but sublimed when its temperature was about that of boiling water; leaving not the slighteft residuum. I am inclined to regard it as a Sean ag combination of phosphoric and murfatic acid in “their dry phoric and states. muriatic acidss The fluid was of a pale greenifh yellow ae and Very Properties of .. limpid; when exposed to air, it rapidly disappeared, emitting the Suid. dense white fumes, which had a ftrong smell differing a ht- tle from that of muriatic acid. It reddened litmus paper in its common state, but had no effect upon litmus paper which had been well dried, and which was immediately dipped into it. It was a noncon- ductor of electricity. It heated when mixed with water, A compound arid evolved muriatic acid gas. I consider it as a compound fel pate nan of phosphorous acid, and muriatic acid, Loth free from acids free from water*, water, Having failed in obtaining uncombined muriatic acid in Sulphu; heat- ed in oximu- this way, I performed a similar process with sulphur, but I °° 7" 0xIme riatic acid gags was unable to cause it to inflame in oximuriatic acid gas. When it was heated in it, it produced an orange coloured liquid, and yellow fumes passed into the neck of the retort, which condensed into a greenish yellow fluid. By repeated- ly passing oximuriatic acid through this fluid, and distilling ‘it several times in the gas, I rendered it of a bright olive * I attempted to obtain dry muriatic acid likewise from the phosphuret- Phosphutetted fed muriatic acid of Mess. Gay-Lussac and Thenard, by distilliug it in re- muriatic acid distilled in oF igen and oxi- muriatic gas. / torts containing oxigen gas, and oximuriatic acid gas. In the first case, the retort was shattered by the combustion of the phosphorus, with a violent explosion. In the second, compounds, similar to those described above, were formed, ~ : H 2 colour, 100 ANALYTICAL EXPERIMENTS ON MURIATIC ACID. colour, and in this case it seemed to be a compound of dry sulphuric and muriatic acid, holding in’solution a very little sulphur. When it was heated in contact with sulphur, it: rapidly dissolved it, and then became ofa bright red colour, and when saturated with sulphur, of a pale golden colour*. No permanent aeriform fluid was evolved in any of these operations, and no muriatic gas appeared, unless moisture’ was introduced. As there seemed little chance of procuring uncombined muriatic acid, it was desirable to ascertain what would be the effects of potassium upon it in these singular com- pounds. Potassium in- ‘When potassium was introduced into the fluid generated, troduced into i : s the fluid from by the action of phosphorus on corrosive sublimate, at first muriate of it slightly etfervesced, from the action of the liquid en the varanen 2 moist crust of potash surrounding it; but the metal soon ; appeared perfectly splendid, and swimming on the surface. I attempted to fuse it by heating the fluid, but it entered into ebullition at a temperature below that of the fusion of the potassium ; indeed the mere heat of the hand was suffi- cient for the effect. On examining the potassium, I found that it was combined at the surface with phosphorus, and gave phosphuretted hidrogen by its operation upon water. The fluid de- I endeavoured, by repeatedly distilling the Auid from prived ofa con- 4 f \ : siderable quan- Potassium in a close vessel, to free it from phosphorus, and tity of phos- in. this way I succeeded in depriving it of a considerable phorus, : ea: quantity of this substance. and heated L introduced ten or twelve drops of the liquid, which had ie been thus treated, intoa small plate glass retort, containing six grains of potassium. The retort was exhausted after having been twice filled with hidrogen, the liquid was made to boil, and the retort kept warm till the whole had disap- peared as elastic vapour. ‘The potassium was then heated by the point of a spirit Jamp; it had scarcely melted, when it burst into a most brilliant flame, as splendid as that of phosphorus in oxigen gas, and the retort was deftroyed by the rapidity of combustion. * All these substances seem to be of the same nature as the singular. . compound, is gatphuretted muriatic acid discovered by Dr. Thomson, noticed in page 923, ; | n %, fe ANALYTICAL EXPERIMENTS ON MURIATIC ACID. In other trials made upon smaller quantities after various failures, I wasat last able to obtain the results; there was no proof of the evolution of any permanent elastic fluid during the operation. A solid mass remained of a greenish colour at the surface, but dark gray in the interior. It was ex- tremely inflammable, and often burnt spontaneoufly when exposed to air; when thrown upon water, it produced a vio-= lent explosion, with a smell like that of phosphuretted hi- drogen. In the residuum of its combustion there was found muriate of potash, and phosphate of potash. 1 endeavoured to perform this’ experiment in an iron tube, hoping, that, if the muriatic acid was decomposed in the process, its inflammable element, potassium, and phos- phorus, might be separated from each other by a high de- gree of heat ; but in the first part of the operation the action was so intense, as to produce a destruction of the apparatus, and the stop-cock was separated from the tube with a loud detonation. I heated potassium in the vapour of the compound of muriatic and phosphoric acid ; but in this case the inflam- mation was still more intense, and in all the experiments, that I have hitherto tried, the glass vessels have been either fused or broken ; the solid residuum has however appeared to be of the same kind as that I have just described, The results of the operation of the sulphuretted com- pounds, containing muriatic acid free frem water, upon po- tassium are still more extraordinary than those of the phos- phuretted coinpounds. When a piece of potassium is introduced into the sub- - stance that distils over during the action of heated sulphur upon oximuriatic acid, it at tirst produces a slight efferves- cence, and if the volume of the potassium considerably ex- ceeds that of the liquid, it soon explodes | with a atiplent re- ort, and a most intense light. Pp f{ have endeavoured to collect the results of this operation, by causing the explosion to take place in large exhausted plate glass retorts; but, except in a case in which L used only about a quarter of a grain, [ never succeeded. Gene- rally the retort, though connected with the air pump at the time, was broken into atoms; and the explosion produced éi by 10} Results, An iron tube destroyed in the experi- ment. Potassium heated in the- vapour of the compound with phospho Tic ecid, Action of po- | tassium on the sulpburetted compounds, Violence of the explosion, 102 ON THE NATURE OF CERTAIN BODIES. by a grain of potassium, and an equal quantity of the fluid, has appeared to me considerably louder than that of a mus- ket. Solid com- In the case in which I succeeded in exploding a quarter of pound formed, Tame ie Bet a grain, it was not possible for me to ascertain if any gase- ous matter was evolved ; but a solid compound was formed of a very deep gray tint, which burnt, throwing off bright scintillations, when gently heated, which inflamed when touched with water, and gave the most brilliant sparks, like those thrown off by iron in oxigen gas. Its properties certainly differed from those of any com- pound of sulphur and potassium that i have seen: whether it contains the muriatic basis must however be still a matter of inquiry, The highly ine There is, however, much reason for supposing, that, in prea "the singular phenomena of inflammation and detonation compounds ‘that have been described, the muriatic acid cannot be en- leeks tirely passive: and it does not seem unfair to infer, that the ‘uuiiatic acid, transfer of its oxigen, and the production of a novel sub- stance, are connected with such effects ; and that the bighly inflammable nature of the new compounds partly depends upon this circumstance. Iam still pursuing the inquiry, and U shall not fail immediately to communicate to the Society such results as may in ta me worthy of their attention. g. Some general Observations, with Experiments. An experiment has been Jately published, which appeared so immediately connected with the discussion entered into in the second section of this paper, that I repeated it with much earnestness. Experimentof In Wir. Nicholson’s Jeurnal for December, Dr. Wood- Dr. W cod- Pin) : : ed ; iaiiae: house has given an account of a process, in which the action of water caused the inflammation of a mixture of four parts of charcoal and one of pearlash, that bad been strongly ig- nited together, and the emission of ammonia from them. If thought it possible, that im this case a -ubstance might be formed similar to the residuam described in page 50*; but. See Journal, yol. XXII, p. 250, by ee ee ON THE NATURE OF CERTAIN BODIEs. 103. by cooling the mixture out of the contact of nitregen, 1 found that no ammonia was formed; and this substance evidently owed its existence’ to the absorption of atmosphe- rical air by the charcoal *. The experiments that I have detailed on the acids offer New views of some new views with respect to the nature of acidity. That peeks, ot a compound of muriatic acid with oxide of tin or phosphorus arate should not redden vegetable blues, might be ascribed to a species of neutralization by the oxide or inflammable body; but the same reasoning will not apply to the dry com- pounds, which contain acid matter only, and which are pre- cisely similar as to this quality. Let a piece of dry and warm litmus paper be moistened with the compound of mu- riatic and phosphorous acid, it perfectly retains its colour. Let it then be placed upon a piece of moistened litmus paper, it instantly becomes of a bright red, heats, and deve- lopes muriatic acid gas. All the fluid acids that contain water are excellent con- Fluid acids ductors of electricity, in the class called that of imperfect ABebosuscll ae conductors; but the compounds to which I have just al- tors of electri- luded are nonconductors in the same degree as oils, with “"* which they are perfectly miscible. When I first examined wmuriatic acid, in its combinations free from moisture, I had great hopes of decomposing them by electricity ; but there was no action without contact of the wires, and the spark seemed to separate no one of their constituents, but only to - render them gaseous. The circumstance likewise applies ' -® Potash or pearlash is easily decomposed by the combined attractions Potash decome of charcoal and iron; but it is not decomposable by charcoal, or, when posed by the perfectly dry, by ivon alone. Two combustible bodics seem to be required oe : i si : ; tities of two by their combined affinities for the effect; thus in the experiment with cqmbustibles. the gun barrel, iron and hidrogen are concerned. I consider Homberg’s ‘ pyrophorus as a triple compound of potassium, sulphur, and charcoal; - and in this ancient process, the potash is probably decomposed by two affinities. ‘“Mhe substance is perfectly imitated by heating together ten parts of charcoal, two of potassium, and one cf su!phur. When I first showed the production of potassium to Dr. Wollaston in October 1807, he stated, that this new fact induced him to conceive, that the action of potash upon platina was owing to the formation of po- | tassium, and proposed it as a-matter of research, whether the alkali might not be decomposed by the joint action of platina and charcoal, te S104 ON THE NATURE OF CERTAIN BODIES, to the boracic acid, which is a good conductor as long as it contains water ; but which, when freed from water and made fluid by heat, is then a nonconductor., | Alkalis &c. The alkalis, and the earthy compounds, and the oxides, fhe ad as dry as we can obtain them, though nonconductors when eonductors solid, are on the contrary, all conductors when rendered _ when fused. fluid by ida, ‘Water in mu- When muriatic acid, existing in combination with phos« eabeirin cus phorous or phosphoric acid, is rendered gaseous by the ac~ tion of water, the quantity of this fluid that disappears at least equals from one third to two fifths of the weight of the acid gas produced ; a circumstance that agrees with the in- dications given by the action of potassium*. Muriate of I attempted to procure a compound of dry muriatic and eae carbonic acids, honing that it might be gaseous, and that through ig- the two acids might be decomposable at the same time by nited charcoal, potassium. The process that I employed was by passing corrosive sublimate in vapour through charcoal ignited to whiteness; but 1 obtained a very small quantity of gas, which seemed to be a mixture of common muriatic acid gas aud carbonic acid gas; a very minute portion of running mercury only was obtained, by a long continuation of the process ; and the slight decomposition, that did take place, I am inclined to attribute to the production of water by the action of the hidrogen of the charcoal upon the oxigen of the oxide of mercury. Muriatic acid = In mixing muriatic acid gas with carbonic acid, or oxigen, Jae Oe or hidrogen, the gasses being in their common states as to ether gasses, moisture, there was always a cloudiness produced ; doubt- less owing to the attraction of their water to form liquid muriatic acid. * Page 101. + These facts, and the other facts ef the same kind, explain the diffis culty ef the decomposition of the metallic munates in common processes of metallurgy. They likewise explain other phenomena in the agencies" of muriatic salts. In all cases when a muriatic salt is decomposed by an _acid, and muriatic acid gas set free, there appea's to be a double affinity, thet of the acid for the basis, and of the muriatic acid for water; pure murriatic acid does not seem capable of being displaced by any other M ate . ‘ acid P On ‘oa. bo< Pe ee ee = ng ee ON THE 'NATURE OF CERTAIN BODIES. 1035 On fluoric acid gas no such effect was occasioned. This put not from fact, at first view, might be supposed to show that the hi- fluoric acid drogen evolved by the action of potassium upon fluoric acrd ad gas is owing to water in actual combination with it, like that in muriatic acid gas, and which may be essential to its elastic state; but itis more probable, from the smallness of the quantity, and from the difference of the quantity in dif ferent cases, that the moisture is merely in that state of dif fusion or solution in which it exists in gasses in general; though from the disposition of water to be deposited in this acid gas in the form of an acid solution, it must be either less in quantity, or in a less free state, so as to require for jts exhibition much mo e delicate hygrometrical tests. The facts advanced in this Lecture atford no new argue No farther ments in favour of an idea, to which I referred in my Pag pantera communication to the Society, that of hidrogen being a common prin- common principle in ali inflammable bodies; and except eas in instances which are still under investigation, and concern- j ing which no precise conclusions can as yet be drawn, the generalization of Lavoisier happily applies to the explana~ tion of all the new phenomena. In proportion as progress is made towards the knowledge Sulphurand of pure combustible bases, so in proportion is the number of Beer eek metallic substances increased; and itis probable, that sulphur ic peak ai and phosphorus, could they be perfectly deprived of oxi- bases. gen, would belong to this class of bodies. Possibly their pure elementary matter may be procured by distillation, at a high heat, from metallic alloys, in which they have been - acted upon by sodium or potassium. I hope soon to be able to try this experiment. As our inquiries at present stand, the great general divi- pernaps all be- sion of natural bodies is into matter which is, or may be 4¢s; except supposed to be, metallic, and oxigen; but till the problem ae ce concerning the nature of nitrogen is fully solved, all syte- matic arrangements made upon this idea must be regarded as premature, TV. 106 Formation of thunder storms. ON ATMOSPHERIC PHENOMENA, IV. Extract of a Letter JSrom Mr. J. B. van Mons, Member of the Institutes of France and Holland, to the Editor, on Atmospheric Phenomena, SIR, ly a paper which I laid before the Batavian Society of Experimental Philosophy at Rotterdam, I showed, that thunder storms form in the atmosphere spontaneously, and wholly. The diminution of sidereal, and particularly of lunar attraction, suffers the air to sink down, by depriving it of the additional elasticity this attraction imparted to it; this sinking loosens the union between the air and water ; , Clouds. the temperature is raised by the separation of the caloric, that served as the medium of this union; and the water se- parates in some part or other of the atmosphere, forming a cloud. This cloud soon enlarges by the continuation of the same cause, the caloric separates from it in great abun- dance, and, as the air is a very bad conductor of heat, this _can neither diffuse itself, nor be dissipated in the form of Water convert. ed inio a per- manent gas by caloric in a State approach- ing to that of electric fluid, which is the cause of per- manent gasses. Different states of caloric, light, a modification of caloric. into which it is not suffici- ently concentrated to transfornr itself, adopts the state of electric fluid, and decomposes the water of the cloud. It is probable, that ‘this effect happens only to a very slight quantity of caloric; and that the portion of this prin- ciple, which in combination with air serves to convert water inte a permanent gas, is contained in this union in the state of electric fluid, or at léast in a state intermediate either to that of heat and electricity, or of electricity and light ; which fourth state being incapable of subsisting except in combination, will never be known to us separately, or otherwise than hy its effeéts, This state is the agent, by means of which permanent gasses retain their state. With the bases of these gasses it enters into a chemical union, which can be broken only by an affinity of the same na- ture. Caloric alone cannot convert these bases into gas, before 1g ’ : ON ATMOSPHERIC PHENOMENA, 107 it is sufficiently concentrated to assume the requisite elase ticity, and then it is in the state of hight. Light, though little concentrated, produces this effect, because it has only to lose a little of its elasticity to become electricity, or sub- electricity, the fourth modification of caloric; which excess of elasticity it transmits howeyer to the caloric, with which the bases abovementioned are fixed, and which has lost much of its natural elasticity in that fixation. Thus more or less elasticity constitutes all the ditference between light, the electric fluid, sublight, and subelectricity, if indeed this exist, and heat. We cannot take a sincle step in na- Their ready % tural philosophy or chemistry, without perceiving the faci- eee ae lity with which these agents are metamorphosed one into cause .f many another; a metamorphosis on which depends a very great phenomena, number of phenomena. It is the heat alone that separates in great abundance, Heat partially and in a distinct part of the atmosphere, which can thus “UC COntUsty separated only transform itself into electric fluid. That which is produced pecomes elec by the general loosening [re achement] of the air, or a cer? city. tain de:omposition of this tluid in its aqueous Combiuativa, and which heats the atmosphere, has no occasion -to diftuse itself, bee generally separated, and it remains heat. Every fYeat of the increase or diminution of the temperature of the air is 4! 20% commu. spontaneous, and not communicated, or conducted by the a ate : . ofcaloric would change the face of these globes; while in this hypothesis change the face the equilibrium is scarcely ever interrupted. These globes of things; then would not be visible but from the extreme limits of their atmospheres, and where the caloric, separated from its combinations, is transformed into light: and the opacity of a globe would not at all prevent this effect, in which the globe itself would not interfere; which would make a won- and our astro- derful difference in the cal¢ulations, from which we have pemeshenae determined the apparent magnitudes of the celestial bodies; be erroneous, as in this case their magnitudes would have been calculated from the extent of their atmospheres, and by no means from that of the globes or celestial bodies themselves; and the light, which renders these bodies visible to us, would not be reflected light, but light extricated from them, or re= turning toward the Sun. It is tv be understood, that this The presence extrication cannot take place, except as far as the atmo- gonad sag sphere faces the Sun, and is under the direct iufluence of tract this tight. its attractive power; otherwise the light extricated would diffuse itself through space; take a course different from that to the Sun, and not reach the atmosphere of that ce- estial body, where alone it can resume its character of light. Nothing prevents the light in this return from traversing Vou. XXIV—Ocr. 1909, I ether 114 Cause of mo- tion in plants, CAUSE OF MOTION IN PLANTS. other atmospheres. It is by the light refracted in this pas- sage, that we see the globes from igtlk it emanates. I am, Sir, with great esteem, Yours, &c. J. B. van MONS. V. Remaining Proof of the Cause of Motion in Plants ex- plained; and what ts called the Sleep of Plants shown to be Relaxation only. By Mrs. Acnus Ipputson. | To Mr. NICHOLSON. SIR, Ayxi OUS to complete the proofs of that idea sug- gested in my Jast paper, concerning the motion of plants; and to show, that I should not have endeavoured to call the attention of the public to this subject, had I not. possessed what appeared to me to be the most incontrovertible argu- ments in its favour, with the most solid reasons for believ- ing, not only ‘“ that this leatherlike substance and the ‘ spiral wire are the cause of motion in plants,” and of every No feeling or volition in plants, ®piral wire, degree of irritability (which I was at first fearfal of ad- vancing), but that “ they are also the cause of what has been mistaken for the sleep of plants.” In short, this ap- pears to me perfectly to explain all that has hitherto been considered as feeling or volition in‘plants, and to ‘resolve it into mechanical power; and the complete management of the spiral wire. The interior formation of plants, when duly magnified by the scolar: microscope, proves the vegeta- ble world to be coinposed of machines governed wholly by light and. moisture; and dependant on theap causes for motion. et 95 The spiral wire may ‘be considered as a’ sécondary cause, acted upon by the two'first ; and by its means all the’move- ments of the plant are made, ‘the flower opens and’ shuts in the morning ‘and evening, the leaves warn? or the daggers an ’ : teh ani fe ‘plants CAUSE OF MOTION IN PLANTS. 115 plants wind in their regular order. Nor can the flower opening at a different time of the day, or turning in a diffe- rent manner, militate against the argument; as the constant effect of strong light abel dry cS ails is to contradt the wire; that of darkness and moisture, to dilute it; and it de- Spiral wire res gulates the pends wholly on which way the spiral wire 1s placed, Whe- Gnening of the ther its dilating shall open or shut the flowers: as in mecha- flower, nics, the same spring may be made to turn to the right or to the left, to open or shut a box. Most of the flowers I have observed, that close at noon, are extremely limber in the corolla, which is formed only of a double cuticle, with- out pabulum, and soon overcome by heat; and when this is the case, relaxation directly takes place. Such is the con- volvulus ni/, the hesperantha cinamomea, the tiger plant, the evening primrose, &c. The great Author of nature shows in all his plans a simplicity, that must hourly strike the dissecter of plants, and prove how much mote ability is necessary to produce such simple mechanism, than to invent ‘our more cumbrous machines. . Mirhbel, one of the latest and best of the French botani- cal writers, though his work is one of the first compendiums of the science, has greatly mistaken the subject, merely from not having sufficiently magnified his specimens. He says, ‘‘if the spiral wires were common to most plants (which he does not believe) they could not in any way pro- -mote the motion of plants, because they are confined in a «ase which cannot stretch.” I shall give an exact drawing Case of the of the case, which will I think plainly prove it was made for Spi"! wire no other purpose: but to see this it is necessary to place it in the solar microscope, and Mirbel did not use one. I con- trived to measure its increase by taking it out of a leaf stalk, and placing it between a double pair of pincers, which were laid in a groove, moving them by means of a thread over a very little wheel. They were drawn with a delicacy “no hand could imitate, and it stretched without breaking (by moistening it) from 1 inch and a quarter, to 2 inches ‘wanting 2 tenths, but it was after being apparently much contracted by light in the microscope. As to the spiral wire made te it is apparent, that it may be drawn to any length. A larger Stet. renter would algo have convinced Mirbel, that the case SY1: I 2 is 116 CAUSE OF MOTION IN PLANTS. is of so thin a substance, or rather I believe I should say of so loose a one, as plainly to be intended to dilate and con- tract; a few very thin vessels, interlaced with an extremely fine spiral wire, composes it, as will be seen in the plate: while the larger spiral vessels fill up the case in an irregular manner, the nourishing vessels forming a regular circle of Spiral wire tubes round it, and, to complete the contrivance, the midrib ana °F of the leaf is fornved also to contract and dilate a little with i; perfect ease, even in the hardest leaves, as the laurel, &c. But in some leaves there is a curious contrivance to lengthen itin the bosom of the leaves just where the bud is concealed Mid rib of the in Its first birth, as in the ash, plane, &c. The peach, and ae gl most of that order, will stretch the midrib of the leaf far more than is necessary for any succeeding motion: and if any person could doubt the power of the spiral wire to draw up, and of course turn the leaf, he has but to take a leaf so drawn from a nectarine, or peach; for it seems impossi- ble that it shouid not be seen, that it is drawn from the in- side of the midrib, and not from the gathering up of the cuticle of the leaf, which has been suggested. I have seen in the geranium the spiral wire to have stretched the case with such violence, it could not return to its uaual size, but has remained in a spiral form: which shows however how easily the spiral wire acts on the case. Different parts it may be thought, that it was not necessary the stalk stretch in dif- should dilate itself, provided the part within did; but na- ferent degrees: tive finds its account in this arrangement, the leaf stalk could not turn with ease, did not one side of it contract, te wind it round. They have all in this respect their appropriate proportions, the spiral wire stretches to any degree wanted, the case a great deal less than the former, and the outward cuticle has only fleaibility enough not to impede the con- tinual irritability of its inward spiral wire. Extremeeffect In my first letter on this subject, I showed the eflect of of the spiral the spiral wire on plants in general, selecting those that Hem were only commonly affected by it, that I might not be ac- cused of favouring my subject, in order to conceal any weakness the argument migit possess. It is truth alone I seek, and I can have no other attachment to it but sup- posirg it so; my eyes and my microscope must grossly de- ceive CAUSE OF MOTION IN PLANTS. 117 ceive me, before I deceive others, 1 have now to present three of the most sensitive plants I am acquainted with, in order to show the full strength of the spiral wire, and of that sort of leathery substance of which it is composed. The first is the Indian grass that conducts the hygrometer made by Captain Kater; the second is the thorn of the net- tle, which is certainly made of the same leatherlike sub- stance; and the third is the mimosa sensitiva, the bag of which plant is also of the same nature, though infinitely thinner. They are all governed by this substance turned into a spiral wire, and the same substance in another form, When thicker it is certainly infinitely stronger, as it proves by the awn of the grass, which is so powerful, though much of it has lost its spiral wire. There is a water plant that sends up its flower by the same substance, and which | have not been able to procure; but I shall be satisfied with showing the dissection of these plants, perfectly convinced they will be thought sufficient to prove, that this substance is the cause of motion in plants. The first is an Indian grass, but the only part sensitive is Formation of the awn, which is formed of this leatherlike substance, in- ‘he 2¥8 of the Indian grass. - finitely thicker and stronger than the asual spiral wire, and its untwisting would be certainly capable of regulating a much more powerful instrument. The awn is formed of two apparently flat pieces, with a cylindric hollow running through the middle, which is filled with a thick spiral wire, but which I have found in only two pieces: the rest ({ sup- pose from long keeping) must have deeayed. Each side is bristled as the awns of grass generally are, but I neyer could perceive, that these bristles added any sensitive power to the awn, though from their resembling those in the seusitive plant I expected to find that they did. I therefore deprived hoth plants of this ornament; but I could not perceive any difference in their sensibility, and in neither specimen are they twisted. It is quite wonderful to see the strength with which this wire twists and untwists. It is only the very finest part, that can be placed in the solar microscope, without breaking the glasses between which it is laid, though not three tenths of an inch in length. What is extraordi- - hary is, that so made, it will continue to wntwist into two The untwise ; different 118 CAUSE OF MOTION IN PLANTS. ing the awn of different threads, and I doubt not at last separate into as the grass. Formation of the sting of the nettle. fine a wire as runs in the mimosa. The hygrometer made of it is the best that was ever invented, and indeed it is dif- ficult to conceive one more sensible, since at nearly an inch distance the moisture of a finger will cause it to' make one or two revolutions of 100 parts each. The figure of the in- strument was given in your Journal for last July. The next plant is the nettle, irritable only at the awn or sting of the plant. It is a long pipe with a bag at the end, divided into two _parts; the smaller, in which is enclosed the bag of the poison; and the larger, which is below it. The whole bag appears to be formed of the same leather- like substance as the awn of the grass, and to be, in pro- portion to its size, equally affected by light and moisture. The moment the upper part of the pipe is touched, the under part of the bag whirls up, breaks the poison bladder, and throws its contents violently up the pipe, burning the person who touches it, This is instantaneous ; and so sus- Effect of light ceptible is it, that the light thrown on it in the solar micro- on the sting of the nettle. scope has exactly the same effect as the touch. The liquor is protruded with a force quite wonderful up the pipe, till it issues at the minute aperture of the point; but before it does so, the pipe is bent down with a jerk by the spiral wire, exactly as the leaf stalk of the mimosa sensitiva bends _ to the touch: They are managed exactly by the same force, and governed by the same powers, fight and moisture. This description of the nettle will account for its not stinging when pressed hard; the pipes being then broke, and the li-. quor of the nettle, mixing with the poison, dilutes it so completely, that it has no longer any effect. It will be seen, that the spiral wire is carried round the bag, and that it is Lays down its drawn together by the contraction of the wire: and to com- stingsatnight. plete the likeness of the three plants.1 must mention, that Sensitive plant. the nettle lays down its large stings every evening just as the sensitive plant does its branches, and that a awn of the grass slso untwists towards evening. I shall now turn to the mimosa sen: itiva, ‘which has less of real strength, bat more mechanism than ihe other two. Its. motions proceed from the same cause, which is not only the spiral wire, but a bag of the same Jeathery kind, that~ contracts CAUSE OF MOTION EN PLANTS. hi9 wontracts and dilates: but the plant seems much more to “depend on the spiral wire., It is impossible not to be struck ‘with astonishmeut and admiration at the beauty and deli- ; ‘eacy. of the,contrivanee, which is far more artificial than the works of nature generally are; and | know not a plant, that has. taken me so much time, and given me so much trouble, to deveiope the different joints, pulleys, knots, and bolts, I __ have long perceived, that a plant is sensitive in proportion _ to the tight manner in which it is twisted, and the fhort dis- tance between the knots: now there is scarcely in this “plant 75 of an imch between the knots; and the spiral is twisted as tight.as possible. I could wot persuade myself the sketch was exact, till I had from different specimens _ drawn it twelve or fourteen times ; but I have exposed the greatest part to,the;view of so many friends, that I think I qpay:traly answer for its being exactly sketched after nature. At D. fig.1, Pl. IV, are the springs that govern each leaf, Mechanism of dd is the stalk. Each leaf has a base cc, which serves to the leaf. concentrate the spiral wires, These passing over in every direction, being drawn through the narruw part of the stem by the strings 6066, press the stem together; and, when “touched, lay the leaves one on the other the whole way down the leaf stalk. But before the ftimulus is applied ; the stem is flattened in a contrary direction. The ball of the leaf. is hollow, and filled with oil. The parts ee and pp, Pl. ITI, fig. 8, are made of that leathery substance, which \ forms the edisialen and is contracted by the light in the solar “mier oscrope, just as the hag of the nettle is acted upon, or the: twisting part of the grass. The parts e e contain the “oil, which serves to alba the knots (I suppose) and en- able them to slip over each other; beside probably acting some important part in the Picdiadads of the various gasses _and juices in the composition of the plant. When touched the whole string relaxes at oo, aiid lets the branch fall. ’This it would also do at m, if. it was not supparted by the Wood vessels turning into the leaf. Fig. 2, PI. IV, is the part ee pp, uncut, and in/its natural state. The sort of ~Wolts are retained in their places by, the wood vessels which : se¥os them in every direction; as in trailling plants they . oe q “Ao; ve defend the bud from accident. Ishould have placed. ag: then ¢ 120 CAUSE OF MOTION IN PLANTS. them in the sketch, had I not: been fearful, b» miving them with the spiral wire, to make such confusion, they would not be known one from the other. But it is easy to under stand, that by crossing vessels they are retained in their present situation. Seminal leaves J must now mention a circumstance, which helps rently a ho epiral | in my mind to prove, that the spiral is the cause of motion, It is that in the seminal leaves there is no spiral wire; and in the seminal leaves there is no motion whatever.’ In de- scribing the spiral wire I did not mention the case, in which it is confined, because | wished at the same time to give a sketch of it to avoid confusion. It will now be found in Plate IV, fig. 4. aie Droseraacaulis J might add to the three plants I have given mauy others, very curious. in which the spiral wire distinguishes itself. The drosera acaulis is entirely governed by the spiral wire, which enters the hairs, or rather arms of the leaf, and the moment a fly touches it, it collapses, confining it within its circle; or should the fly escape the first arm, the point leaves so viscid a humour, that the next is sure to be caught. This is in- finitely more curious in its formation than the dionea mus- cipula; which is also governed by the spiral wire turning over a ball like the mimosa, and drawing the leaves together in the same manner. But drosera is managed in a more peculiar way, and well erent a drawing, which I will give in my next. — pie Leatherlike I hope to be perfectly under stood, in giving an account of sursyancestne that which regulates the motion of plants, that the leathers with the “spiral like substance, and the spiral wire, are the same matter. The wire. thickness of the first balancing the force the second gains, by its spiral form ; and the latter gains much oo also from the case that encloses it. Recapitulation Before [ close this letter you will excuse my recapitula- pee acter ting the proofs brought forward in it and the former. The spiral wire is found in every leaf that has motion; in no leaf that does not move; in no firs, grasses, sea-weed, except confervas, * and the confervas alone of all the tribe have motéon. It is found in no chenopodinms, salsolas, or ice plants. In leaves that have no otber motion than toward the sfem and back again, the spiral wire occurs oy us the midrib of the leaf , : CAUSE OF MOTION IN PLANTS. 121 leaf; in all others, it is found even to the smallest spire, The spiral wire is made to stretch, and so does its case. They both contract and dilate in the solar microscope. The spiral wire is found in al! the sensitive plants in great quan- tities, and in every part except the seminal leaves; and it is the seminal leaves alone that have no motion. I may add, that, when the spiral wires were divided, the leaf would not turn. I think it 1s hardly possible, where positive evidence ig not td be had, to prove a fact in a more direct manner 3 and that I may say, that plants bave spiral wires, which, con- tracted and dilated by hght and moisture, are the cause of aj] motion in plants. The sleep of plants is nothing more than the dilating and Sleep of plants. lengthening of the spiral wire. from the evening moisture; and I think the very appearance of it proves it to be so. Does not every violent rain, long continued, produce the same effect? Does not the common acacia, when wetted by continued rain, drop her leaves as at night? Sodoes the gleditsia triacanthos also with even less moisture. The esculus hippocastanum droops as soon as the leaves are old, and begin to decay. Every plant drops its leaves before the leaves go off. It appears to me, that there is no expres- sion in the human countenance more easy to be understood, Strength and than the expression of strength and debility in the appear-debility in ance of plants. Nor did I ever see a plant close its leaves esti without showing even an excess of debility in every other part. in one of my two former letters I mentioned two in- plants have ne stances of apparent volition in plants, to show how many volition. things of that sort happen, to mislead the judgment: but I have now too often pursued them, till uudeceived, through such a course of experiments, perpetually renewed to gain nothing but disappointment, that | am now most absolutely eonpinced that al] plants are merely macliines, governed by light aud mojsture; and that every idea of their sensibility, or of their volition, is only a proof, that we too often let imagination run away with our judgment. Mechanical - power is sometimes so delicately managed, that it is difficult to trace it even with the solar microscope ; especially as that is is of no use till the specimen is most delicately dissected, and placed 122 CAUSE OF MOTION IN PLANTS. placed in order for this purpose, Such fine instruments ave required, that a surgeon’s collection has scarce need of? | more variety than the botanical dissecter. , Sensitive plant . On immersing a specimen of the mimosa in a iailinsl ee of. aap gk water, to see whether it produced much oxigen, I found igen. what I expected, that the oil in the plant would not permit the water to approach or touch it. It lay quite holiow from: the plant, which closed the moment I placed it there; but the next morning, when the swn shone full on it, it opened, and remained thus till night, when it again closed. ‘Again’ the sun opened it, but from that time for near a fortnight it remained open, and when I took it out of the water it had lost all power of motion, and had I suppose dilated the wire till no longer capable of stretching farther. ‘It gave not much oxigen. I should apologize for the extreme dryness of this letter ; but to explain the formation of any sort of a machine can ‘only be done by the most simple and clear method, and nothing is less entertaining than such a discourse. To ad= vance a few steps nearer to truth is however a certain gain, and if I have made out my proposition to the conviction of those who study the subject, I am satisfied. Those who possess a solar microscope J can only advise to follow me in my experiments, for without seeing it, it is impossible to conceive the amazing effect of light on plants, or almost to imagine what are its powers. Meiperspira- I will not finish this letter without adding a few words on tion in plants. the perspiration of plants; a subject 1 have so repeatedly brought forward. I mentioned in one of my last papers, that, on placing a plant in a growing state, under a glass, I put wnder the glass a paper doubled a few times so as to raise the glass 45 of an inch from the stand ; to introduce under the glass the smadlest quantity of air possible; just enough to prevent the air from stagnating, and the plant from becoming sick or discomposed, and the plant gave out no moisture. This gave me the idea, that it really was thé sickness of the plant, which caused the degree of moisture Duhamel talks of, but which is certainly excessively exag.s e~ rated. But for a farther proof I enclosed a large plant ina silver paper case, with a hoop very thin that wonld preserve it CAUSE OF MOTION IN PLANTS. 123 it from pressing on the plant, and weighing the whole, co- vering the plant, and tying it close at bottom, I left it six hours. The difference of the weight, when I took it out, was half a grain; nor could fT feel the least moisture on the pa= per. On breaking off different branches, and blinding my eyes, I was always able to discover the branch dismembered from the other, provided it had been so for half an hour, from the moist feel of the leaves, that can be compared only to the death-like touch of a dying person. Most plants Moisture have this when in sickness, and I am persuaded when con- poate fined in stagaant air. I think I may therefore finish thes subject also, and say, that there is no sensible perspiration in plants, and that I very much doubt whether there is even in= sensible perspiration: if there\is, it is most trifling. | Tam, Sir, Your obliged servant, Cowley Cott. AGNES IBBETSON. _ Aug. 20 2 Explanation of the Plates. Plate IIT, figs. 1, 2.3, a sting of the nettle in its different Explanation of states. Fig. 1, its perfect state, when placed in the solar the plates. microscope, and before it stings: z the bag of poison : x the spiral wire. Fig. 2, the sting after the poison has been thrown to the point ; x the spiral wire contracted. This is not drawn up at night, when the stings bend, but only when it is touched. if however a mirror be held over them, the poison is thrown up directly. Fig. 3, the sting of the nettle very much een. ae 4, untwisted Indian grass greatly magnified, showing the manner in which it is formed. This is the first grass Va reign or English, in which I ever found the spiral wire; but I doubt whether it runs through the whole of the grass. Fig. 5, the awn of the grass. Figs. 6 and 7, the grass twisted. ’ Fig. 8, a longitud’:al section of the leaf stalk of the mi- mosa sensitiva, the middle part containing five cases full of spiral wire, and e.c extrem t contaiuiug only three. Pl. IV, fig. 1, a leaf of the mimosa. Fig. 124 Single repe- tends divi- sible by any number, ex- eept 5 and its multiples. CURIOUS PROPERTY OF SINGLE REPETENDS. Fig. 2, the extremity of the leaf stalk, at pp, Pl, III, fig. 8, undivided. Fig. 3, horizontal section of the stem of the sensitive plant. Fig. 4, part of a case full of the spiral wire much more magnified than in fig. 8 of P]. III. In many plants it js much thicker, but always loose: that is, it is formed exactly hke this, but dowbled, or trebled, I imagine to preserve it from the effect the moisture of the nourishing vessels might have on it. Fig. 5, the spiral wire still more magnified. VI. A curious Property of Single Repetends. In a Letter from hs RNB oie Esq. Cromer, Norfolk, Aug. 10th, 1809. To Mr. NICHOLSON. SIR, A Friend of mine, some time since, in ‘the process of an arithmetical operation, observed, that any repetend digit, as 311111 &c., or 777777 &c., would divide by the odd num- bers 3, 7, 9, and 11; and supposing it probable, that such repetends would divide by any odd number, 5 and its mul- tiples excepted, he had the patience to try all such divisors from 1 to 151, and found them to succeed, by takingya suf ficient number of digits for the dividend, which, he observ- ed, never excceded the number denoted by the divisor. This property of numbers my friend submitted to me for demon- stration, and as it is certainly a very curious one, | thought it probable, that it might not be unacceptable to many of your. readers. I have ecard ingly. sent it herewith, in the _ form of a proposition, accompanied with a demonstration, IT am, Sir, ' Your obliged and humble servant, W. SAINT, Proposition. GURIOUS PROPERTY OF SINGLE REPETENDS. PROPOSITION. EV"=RY odd number, except 5 and its multiples, is a di- visor of a repetend of any of the nine digits; and the num- ber of digits necessary to form the dividend will never ex~ ceed the number expressed by the divisor, Demonstration. First it is evident, that, if we can prove the truth of this propasition for a repetend of umits, it must necessarily be true also for a repetend of any other digit, since such repe- tend would be a multiple of a repetend of units. _ Again if the former part of the proposition be true, the truth of the latter part also easily follows; forif 111111, &e. be divisible by any number D, no remainder can recur, till ‘after the remainder 0 has occurred ; since, if any remainder recurred before the division terminated, the operation would proceed with precisely the fame figures as when that remain- der first occurred; and thus this remainder would recur again, and so on ad infinitum ; and hence the division would never terminate, or 111111 &c. would not be divisible by D, contrary to hypothesis. Now since all the possible re- mainders, which can occur in dividing 111111 &e. by D, will be between D and 0 inclusive, therefore there can be but D different remainders; and since, in the operation of division, each figure in the dividend will give one remainder, therefore D figures in the dividend will give D remainders. Hence in dividing 111111 &c. to D places of digitsby D, all the different remainders, which can take place, will occur; and therefore, if the dividend were to consist of more digits ‘than are denoted by the divisor, some one or more of the re- mainders would recur; and hence if the division did not terminate prev’ous to this recurrence, it would never termi- nate, but would go omad infinitum. Consequently, if 111111 &c. be ever divisible by D, it must be so when or before the dividend consists of D digits. We say before, because, though the remainder 0 might not occur precisely at the end ef D digits, yet, from what has been shewn above, if that remainder 125 Propositien, Demonstra- tion, 126 Tron recome mended for siairs, SECURITY AGAINST FIRE. | remainder ever occur, it must necessarily do so before the di- vidend exceeds D digits. Let therefore 111111 &¢. to D eet aio divided by D, give g for a quotient and r fora rematader, now since this remainder will recur again, whether LLLI11 &e. de or be mot divisible by D, if the number of digits D in the dividend be increased, let therefore 111111 &c. to D + d digits, when | divided by D, give Q for a quotient and 7 for a remamder.— In the first case we have 111111 &c. to D digits = Dq +r, and in the second case we have 111111 &c. to D 4 d digits =D Q +7, the difference of these equations gives 111111 &c. 000000, &ce. = DQ — D gq, where it is evident the units will consist of d digits and the ciphers of D places, whence _ 111111 &e...to d digits 000000 &c. D places Oe ar ielliea papa ae RE =a whole number, where the divisor D 1s any number even or edd. Now the 111111 &c--tod digits must, without the ciphers, be divisible by every odd number not greater than the divisor D (5 and its multiples excepted) for if it were not, whatever were the remainder, suppose R for instance, we should have R 0000 &c+-to D ciphers divisible by an edd number not a multiple of 5, which is impossible; moreover 111111 &c.--tod digits, will not divide by 2, or by 5, or by any multiple of these numbers, since no multiple of 2 or & can terminate with 1: hence 111111 &e. to d digits is divi- sible by any odd number, except 5 and its multiples, where d the number of digits in the dividend can never be greater than D the divisor, since the recurrence of any scr np must take place in D digits of the dividend. Q. E. D. 2S ee VII. ; Qn the Use of fron for Stairs, and instead of the Timbers of Houses, as a Security against Fire. In a Letter from Mr. Bensamin Cook. To Mr. NICHOLSON. SIR, ln a former paper I threw out some loose hints on the ad- vantage of employing iron in various articles of furniture, as ‘SECURITY AGAINST FIRE. 107° | asa substitute for mahogany and other expensive woods. I will now add to it a mode of substituting it in the place of oak, and other less expensive woods. “The chief use I would recommend it fori; is in stairs, and stair cases, but especially in the metropolis, where so many fires are constantly happening, and where so many lives are “annually lost by them; where fo many plans have been .de- ‘vised for fire-escapes, and so few, if any, that have ever an- swered the end. I have long wondered some plan has not heen thought of, security which provided security within doors, instead of waiting for Shee fires ‘ 2 : : - shouid be pram precarious assistance from without. It is not so easy to ine y;3.4 wikia troduce a remedy, such a remedy I am now proposing, into doors. houses already built; either from a parsimoniousness of the owners, or from a fancied security in the idea, that with them there is no,danger, and therefore they will not go to the ex- pease of addinga new flight of stairs ; which beside the ex pense, will be attended with much trouble and confusion. _ The other class, that are hkely to hinder the adoption of the remedy, are those that are not able to go to the expense of the alteration. But those persons that could afford it, and wished to provide for the danger of fire, if a probable re- ‘medy was shown them, might certainly do it; and as houses are continually altering, and new ones constantly being erected, certainly it would decrease the evil, and be intro- ducing, if but slowly, a system that in years would increase, and be of essential utility. - The remedy I mean is stairs and stair cases made either this would be of cast and sheet iron combined, or cast iron only. The had from irow framing for the stairs, to which the boards are nailed in the ae present mode, might all be cast, and screwed together. Of course this framing would be considerably lighter in appear- ance, than if made of wood. ‘The front and top of the step, if made of sheet irou, might be attached with six or eight piodge of con. _iserews, to the cast iron framing; and in order to give it a structing neat finish, a light bevelled moulding might run all round ‘oleae the front of every step, and the joimtings be neatly screwed to it with small screws, with heads countersunk into the . “so ee But if the front and top of the, steps were cast in plates, MOG i which 128 May be made very hand- some. SECURITY AGAINST FIRE. which I think the cheapest and easiest way, the framing might be cast with suk edges; so that the front and top of the steps would just fit into the groved framing, aad four or six screws would fasten them in a few moments. All the tops and fronts, when cast in a monid, would fit in the fram- ing; and all the framing being so cast to fit, a flight of stairs would soon be put acpeshice the plates might all be cast light, and, when all screwed together, would apne a hand- some mass of iron. They who are unaquainted with the method of casting may suppose, that the work would leave the sand roughand uneven; but, if it is cast in fine sand, it will be level and uniform, and be ready for screwing together, the sarfaces will be as regular as stone, when put together, and not so hable to wear smooth, and endanger a person to slip off, in coming down stairs. Such stairs will certainly be much handsomer than stone, and of half the price, or less: with this advantage, the railing may match, and be made of cast iron also. They would appear very beautiful, if well painted, to imitate mahogany, as also the railing, which might be cast in very handsome and various fanciful patterns. There would Common Staircases. be much scope for genius and fancy in devising and execu~' ting the staircases and railings, as almost any device, almost any antique figure, or gothic scroll, might be tastefully in= troduced, forming an elegant, indeed I might venture to say, if expense was not the object, the most beautiful, and certainly the most durable, staircases, that can pees be formed. Common staircases of iron would certainly be made as cheap, or cheaper than of oak; and I think, if a manufae- tory was to be established, and a regular trade made of it, they might afford them as cheap as any kind of wood, and a great deal more work might be put in them, as far as con- _ cerns the ornamental part: for the same cast, that formed only straigh tlines, would, by varying the mould, at the fame expense, form the most beautiful specimens of antiquity. Therefore wood cannot be brought into comparison with it on the score of taste, nor can price be admitted as an ob-. jection to its introduction. Besides, if painting was looked. upom SE€URITY AGAINST FIRE. 129 upon as an expense, they would always look well if brushed with black lead ; and, as ali houses, except the houses of the lower orders, have carpets up the stairs, the tread would be quite as pleasant as on stairs made of mahogany; and in case of fire, a safe escape would always be ready. Dread- ful must be the situation of those persons, who, waked by the cry of fire, rush to the landings, find the lower rooms are burning; the staircase blazing and falling; and no es- cape left but the dreadful one of precipitating themselves from a window, running the risk of being dashed to pieces, or of remaining in the house, to perish in the flames; when, if the stair case had been of iron, all might have escaped with little or no injury. If iron was introduced for joists, rafters, and beams, they jon beamsand might all be cast hollow, they might all be screwed and pin- rafters, & fire ned together, and have a very light appearance, at the same ea time possessing much more strength than wood. If the ‘spars, on which the floor is laid, were made tight and laid near each other ; and cast:'with a small projecting edge on each side at the bottom of each spar, so that, when laid down, to form the’ floor, a fiat tile, or thin quarry, would just fit in between two spars ; when all the interstices of the floor were filled up with cheap tiles or quarries made on pur- pose, the floor would be fire proof, and made so at a very little expense ; as the spars might be cast light, there being more in number, and would be nearly if not quite as cheap as wood spars; and all the additional expense would be the common fiat tiles, which would not be of much extra value, nor give much trouble in the laying; on which fire proof - floor, the boards might be laid. . By the introducing of iron for timber, the danger of fire Communica- would be much less to be dreaded; for, if a reom iook fire, Sa coe sa its contents and floor could only be destroyed; and the fire could not easily be communicated from room to room. In- deed [ do not see how it is possible for it to extend. The Jarge timbers, that now connect rooms together, would be taken away, which timbers being burnt through, the floor falls, and overwhelms in destruction the rooms and furniture ‘below. . ! Floors could not fall in, if laid on iron. As only the Vou. XX1V.—Ocr. 1809. i boards | 130 "Respiration a subject of im- portance, Its interruption always produ- ees death : but-resuscita- tion may some- times be af- fected, ON RESPIRATION. boards on them could be burnt, roofs could not fall in, if the beams, rafters, &e, wereiron. In fact, a fire could not make its way and spread, if iron was substituted for the timbers now used in building, and few if any lives would ever be lost, if the staircases were made of iron also. I am, your obedient servant, Caroline Street, Aug. 22d, 1809, B. COOK, VUul. On Respiration. By Mr. J. Acton, In u Letier from the Author. | Dear Sin, : Ipswich, 22d Aug. 1809. A GREEABLY to the canclusion of my last letter, I en- ter now upon respiration. Nosubject can be more important, more deserving investigation and serious reflection, than that on which animal life so essentially depends, Whether its utility be referred to the medical and chemical philosopher, as enabling him to take more comprehensive yiews of the cases submitted to his decision, or as generally increasing the sum of hurgan knowledge, it is still the same. The consequences resulting from a thorough insight into this wost important function of vitality exceed all calculation. Some other of the animal functions may be arrested by disease, and their action altogether cease for a time, and the animal shall still continue to live; but in the instance under consideration there cannot be a complete interruption with impunity, whether it take place by immersion in water, or 1) noxious air, or by a ligature tied round the trachea. Cut of by any mgans the communication between the lungs and atmospheric air, and the animal dies; the obvious effect is instantaneous, and nearly similar. It must be admitted however, that resuscitation by timely interference may fre- quenty be brought about, after annnal life has been for some time apparently extinct; but in many instances a few mi- nutes deprivation are sufficient to destroy the vital spark, be- yond the possibility of revival. Ido not flatter myself with Br: being te Sn oa ON RESPIRATION. being able to throw much additional light on a subject, which has been already so extensively discussed by men of the highest attainments: the principal end I have in view is merely to endeavour to establish, as in germination, the simple phenomenon of the absorption of oxigen yas by the blood in the lungs, in contradiction to the theory which sup- poses the emission of solid carbon, and its subsequent union with the oxigen gas of the air to form carbonic acid gas, as stated in my former paper. For this purpose | have con- fined my experiments to the greatest simplicity, conscious how important it must be to demonstrate this one circum- stance beyond any doubt, and thereby afford the means of unerring data for constituting a more distinct theory of re+ Spiration : for I believe it is an axiom in natural philosophy, as well as mathematics, that, if the data be founded in errour, the conclusions derived from them must be false. In order therefore to establish any doctrine upon a secure foundation, it would appear very desirable in the first place, to endéa- vour to remove existing doubts, which perhaps cannot be bet- ter done than by the institution and arrangement of a cer- tain number of facts, placed in so appropriate and lucid a point of view, as shall be calculated to carry conviction to the inquiring mind. These only ought to be considered as the pillars and support of every rational theory ; and the de- cay and failure of them from after experiment and improve- ment should be the signal for its vanishing away, to be re- placed by mere accurate results. For my own part, in pur- ‘suing these investigations I put in no claim for novelty, and my direct object is confined within very narrow bounds, 1 must confess, that my greatest pleasurable feelimg arises principally from the contemplation of the probability of fue ture benefit being derived from them by their stimulating others, who have more energy of mind, with better oppor= tunities and advantages, to resume them with additional ar- dour, so 28 to carry them to the greatest perfection they may be capable of. Could I be convinced, that any experiment [shall perform, or any sentence fiowing from my pen, may have so desirable an effect, my highest ambition would be satisfied, and I should console myself with the reflection, that J have not lived in vain. : Ke A great 131 Object of the present paper. Facts the only secure founs dation of any doerine, 13% Cruelty to ani-, mals, ON RESPIRATICN. A great deal has been lately said respecting cruelty to animals. It has necessarily occurred, that, in the following experiments, it has been found impossible to avoid putting Mice increase very rapidly. When their . food begins to be exhausted, they swallow dirt and sand, This the sto- mach soon re: jects, and then they prey on each other. Not so cruelly them to pain. I can only say, that every wanton infliction of it has been studiously avoided. Those animals which are cousidered as most noxious and insignificant have been pre- ferred for the purpose.. And I have no doubt, if the part of natural history treating of the economy of domestic ver-~ min were more diffused and understood, they would be yielded up without reluctance by the most humane and ten- der hearted for experimental purposes, where thé intention is evidently for instruction and improvement, and not to sa-_ tisfy mere idle curiosity. Mice, for instance, it is well known, under favourable circumstances, such as plenty of foed and the absence of their natural enemies, increase with the most astonishing rapidity, the female often producing nine young ones at a single parturition. The consequence | is, the numbers sooner or later begin to exceed the means of subsistence, When this first happens, and the food is nearly or quite exhausted, they endeavour to repel the first attacks of hunger by pickiag up dirt and sand in sufficient quantity to have the mechanical effect of distending the stemach and intestines. But the delicate coats of the stomach will not long bear the repetition of this artificial food, the sharp angles of the particies of sand at length irritate and inflame that organ, weaken its powers, and compel it to reject it al- together, No other resource is then left to the animal, but to try to sustain tts existence by feeding on those of its own species it can overcome, thus,impelled by the corroding sen- sations of hunger to recur to this unnatural but only method left them to satisfy the most voracious appetites, And this will proceed till nearly or quite the whole community be extinct, if no opportunities of emigration, or supply of food, present itself. I make these remarks from aciual observa- tion: and I am sure it need not be suggested, that often the judiyidual sufferings of these httle animals must be very great in this way, without noticing the length of time they are frequently tormented when in the power of their worst enemy the cat; so that it is merciful to increase the means of destroying them. 1 believe also it will be found that. the manner ON RESPIRATION. 133 manner in which they have been treated in these experiments treated in the must not be compared in severity to the common mode of {lowing steals exterminating them by poison. It is on the first transient Pcs Eel view that humanity shudders at the infliction of pain; could Py poison. she have patience to listen to adequate reasons for what is done, conviction of utility would often take place of cen- sure. Far, very far be it from me by the least word or ac- tion to advocate the cause of cruelty: should I be suspected of so great depravity, I can only say, I feel conscious of de- serving no such accusation ; it is foreign to my nature; not the pokes of the Earth are more distant from each other than is inhumanity in any shape from my genuine feelings. It must however be allowed, and with concern I mention it, that plnlosophers have sometimes im recording their experi- ments particularized the most painful operations on animals with an indifference not very characteristic of a tender na- ture, and sufficient almost to induce a suspicion of a defi- ciency of the finer traits of sensibility, particularly of that species so masterly pourtrayed and inculcated in the instruc- tive and pleasing writings of Mr. Pratt. In the following experiments it will be seen there is a Repetition of sameness and want of variety bordering upon tediousness, aerate which the simplicity of the fact sought to be demonstrated to establish the can alone excuse. I was desirous not to lose any thing for fact. want of repetition; and if by this means a sufficiently strict © analogy be apparent in them, the end will be as well an- swered, as in all probability it would have been by extend- ing them in a more complicated form, which might only have had the effect of rendering the deductions less plain and easy. I must premise, without farther apology, that in these as well as my former experiments, it has not been possible to avoid the introduction of small quantities of atmospheric air; but it will appear, that, so far from having any tenden- cy to vitiate these results, they become in most instances a farther confirmation of them. 18 Oct. 1808, Temp. A5°, Press. 29°20. Exp.1. An accurately graduated jar being filled with Mouse kept in quicksilver and inverted, 17°50 cub, inches of ‘atmospheric aimaapbene air \ 1340 air over mer- cury 50’. Liquid sul- phate of iron impregnated with nitrous gas a better test of oxigen than sulphur- etted alkali. Mouse killed in oxigen gas. Another. Two mice kil ON RESPIRATION. air were passed up (the air of the laboratory being previously examined and ascertained by the average of several trials at a medium temperature and pressure to be composed of 20 parts oxigen and 80 parts nitrogen). A mouse was put through inp mercury into the jar, and suffered to remain 50 minutes. When withdrawn the air was found to have dimi- nished 1°25. in. On exposure te lime water, a farther ab- sorption was observed of 100 c. in. - The remaining 15°25 ce. in. being exposed to liquid sulphuret of potash, 00°46 c. in. were absorbed, leaving a nese of 14°79 c. in., which was nitrogen. It is noe the accuracy of this experiment may be call- ed in question; for, according to the analysis of the air of the laboratory, the whele diminution should have been 3°50 c. in. ; but it was only 2°71 c. in., making a difference of 00°79 c. in., which I attribute to the attempt at operating with the whole quantity of gas, instead of taking an aliquot part of it, which I have since done, and always found to be more easy aud true. Neither do I think the sulphuretted alkalis so good and rapid tests of oxigen as as the liquid sulphate of iron impregnated with nitrous gas. 30 January, 1809. Temp. 44°, P. 28-94. Exp. 2. Into aa inverted Jar in the same manner as the above were passed up 13 cubic inches of oxigen gas nearly pure. A mouse was then conveyed through the mercury into the jar, where it was suffered to remain an hour and a quarter, when it was quite dead, and the gas had. in that time diminished 1:00 cubic inch. ‘ An accident prevented the farther prosecution of this experiment. Exp. 3. At thé same time another mouse was placed in a like quantity of oxigen nearly two hours. When taken out it was quite dead. ‘The gas had diminished as before 1-00 cubic inch, and being then examined by lime water, 89°50 per cent disappeared, showing, that the animal had absorbed nearly the whole of the oxigen, and given out a considerable quantity of carbonic azid gas. i9 Feb. Temp. 63°, P. 30°10. Exp. 4. Two mice were suffered to die in one cubic incl ; of ON RESPIRATION. 135 of atmospheric air over mercury. Upon trying the residue ed in 1c. inch with lime water, 12-90 per cent only were absorbed, evi- 2 ae dently showing the oxigen was not all consumed; and con- sequently the animal dies while yet a portion of oxigen re- mains; most probably from the combined effect of the car- bonic acid gas produced, and the effuvia transpiring from the animal’s body, and which, from this species in particular _ is most highly offensive and disgusting. Exp. 5. The above two mice, when taken out of the jar ne ee while yet warm, were passed up another inverted jar con- ao sileheae taining 4 cubic inches of atmospheric air. After remaining four days no material diminution could be perceived. A portion of the air was then tried with lime water, and 18 per cent absorbed. I did not proceed farther’ with this ex< periment; for, being convinced how different must be the ehemical action of bodies possessing vitality, and those un-= dergoing decomposition, I did not see the utility of endea+ vouring to trace any analogy between them: but to satisfy myself what were the aerial products arising from the putre- ’ faction of animal bodies cut off from contaét with the sur4 rounding air, I instituted the following experiment: Lxp.6. Into an inverted jar filled with mercury J passed Mouse tecent: up a mouse so recently dead as to be quite warm. The next 2 ae sae day a little gas had been produced, which continued to in= mercury: crease, ‘and in seven days amounted to about 2°50 cubic inches. A liquor of a pale red colour had oozed from the body, amounting to about 0°15 parts of a cubic inch of a most fetid and disgusting smell. 100 parts of the gas being exposed to lime water, 81 parts disappeared: The remain- ing 19 parts being submitted to the test for oxigen, 3 parts were absorbed. The residual gas appeared to be nitrogen. If any ammonia had been formed, it must have been con- tained in the liquor, and the fetor arising from that was so very powerful, as to prevent my distinguishing or entering into any nice examination respecting it; but I have some reason to believe its formation is considerably facilitated by the presence of atmospheric air. * 19 Feb. Temp. 63°, P. 30°10. ‘Exp.7. A mouse being passed up an inverted jar over Mouse in ext quicksilver, $& $4. ’ 136 Another. Another, Another. Another. Several mice suffocated in nitrogen Mouse suffo- cated in hidro- gen, ON RESPIRATION. quicksilver, containing 1°62 cubic inch of oxigen nearly pure, after 50 minutes it had diminished 0:19 of a cubic inch. The gas being then exposed to caustic potash ere 0°31 of a cubic inch were absorbed. 14 April, Temp. 46°, P. 29-90. Exp. 8. Another was placed in the same situation in 1:10 cubic inch of oxigen gas. When nearly dead it was with- drawn, and the air found to have decreased 0°40 of a cubic inch, The remainder being submitted to caustic potash, 0°30 of a cubic inch more were taken up, leaving a residue of only 0°40 of a cubic inch. 15 April, Temp. 45°, P. 29°30. Exp.9. Another was placed in the same situation for 56 minutes in 2°40 cubic inches of oxigen. When the mouse was: in, the scale indicated 3:05. At the expiration of the above time it was reduced to 2:80. The decrease would doubtless have been more, but for the casual introduction of some at- a : . ( mospheric air. 19 April, Temp. 42°, P. 29°80. Exp. 10. Another placed in the same situation in 1 cu- bic inch, or 100 parts of oxigen, 29 parts were absorbed, The remaining 71 parts exposed to lime water lost 20 parts more, leaving only 51 paris. 20 April, Temp. 48°, P. 29°60. Exp. 11. A mouse was passed up a jar in the same man- ner into 3°10 cubic inches of oxigen gas, At the expira- tion of 50 minutes the air had decreased to 2°30, which being exposed to caustic potash, 1°60 were absorbed. Exp. 12. Several mice having been suffocated in 4 cubic inches of nitrogen gas, upon trial with lime water it became turbid, and 4 per cent were absorbed. Exp. 13. A mouse having been suffocated in hidrogen gas, on examination by lime-water a trace also of carbonic acid gas could be perceived. 24 June, ON RESPIRATION. 137 24 June, Temp. 65°, P. 29°95. Exp. 14. A mouse being placed in the usual manner in Mouse in oxi- a jar, containing 3 cubic inches of oxigen of the purity of 8°" 98, in SO minutes it was quitedead. The air had then de- creased by observation 1°00 cubic inch, The residuum being treated with lime water, 33°67 per cent disappeared. This was the average of two trials, and 100 parts taken of the remainder, and submitted to impregnated sulphate of iron, 84 per cent were absorbed, making the whole by calcu- lation stand thus. 3°00 cubic inches of oxigen gas Statement of 1:00 diminished in respiration aie iat 2°00 0:67 absorbed by lime water 1°33 : 1°11 absorbed by test for oxigen °22 Residue, being nitrogen. At the same time another was passed up into 3:50 parts of oxigen gas, and at the expiration of 40 minutes 0°90 parts were diminished. 10 July, Temp. 62°, P. 29°70. . Exp.15. Inthe same manner a mouse was passed up Mouse in oxi- into 1°70 cubic inch of oxigen gas. After it was in, the £° 84. scale indicated 2°80 cubic inches. When withdrawn in ten minutes, 1°50 cubic inch. 100 parts being then examined with lime water, 21 parts were taken up, and the remaining 79 parts being exposed to the test for oxigen, 67 parts dis- appeared, leaving a residue of 12 parts, which appeared to be nitrogen. WJ uly, Temp. 60°, P. 29°80. Exp.16. Another being passed up into 1°60 cubic inches A nother. of oxigen gas, the scale then indicated 2-40 cubic inches. When the mouse was quite dead, it had diminished to 2°05; and after it was taken out to 1°25; showing an absorption of 138 Another Another. Another. Another. Mouse in at- mospheric air. ON RESPIRATION. of 0°35 cubic inches. 100 parts being exposed to lime wa- ter, 46 parts were taken up. 14 July, Temp. 65°, P. 29°93. Exp.17. Another being in the same situation in 1°14 cubic inches of oxigen gas, the seale indicated 1°81. In 20 minutes it had diminished to 1:39, an absorption of 0°51 ofa cubic inch having taken place. The jar being by accident overset, it could be proceeded with no farther. Same Time. Exp.18. Another being placed in’ 1:30 cubic inch of oxigen gas, by the scale it was then 2°18. In 20 minutes it had diminished to 1°70 cubic inch, 100 parts by lime water were reduced to 32 parts, which, exposed to the test for oxigen, left only 13 parts of nitrogen. Same Day. Exp. 19. A mouse being put into 1°15. cubic inches of oxigen gas in the same way, the scale, after it was in, indi- - cated 2°00 cubic incbes. At the expiration of 20 minutes it was reduced to 1°47 cubic inch. 100 parts by lime wa= ter were reduced to 43 parts; and these, exposed to the test for oxigen, lost 22 parts, leaving 21 of nitrogen. Same Day. Exp. 20. Another being put into 1°10 cubic inch of oxigen gas, the scale mdicated 1°80 cubic inch; and at the end of 20 minutes 1°50, there being an absorption of 0°50 of acubic inch. Out of 100 parts lime water took up 51 parts: the remaming 49 parts being submitted to the test for oxigen, SI parts disappeared, leaving 18 parts of nitrogen. I Same Day. Exp.2%. Another being placed in 4 eubie inches of atmospheric air, the scale then indicated 4°70. In 20 mi- nutes it had decreased to 4°35 cubic inches. 100 parts be- ing then tried with hime water, 13 parts were taken up; and of the remaining 87 parts exposed to the test for oxigen, 6 parts \ ON RESPIRATION. 133 6 parts were absorbed ; leaving a residue of 81 parts of ni- trogen. Same Day. Exp. 22. Another being placed in 4 cubic inches of at- Another. mospheric air, the scale then indicated 5 cubic inches. In 20 minutes it had decreased to 4°80 cubic inches. 100 parts being then tried with lime water, 15 parts were taken up; and of the remaining 85 parts, exposed to the test for oxi- gen gas, 5 parts were absorbed ; leaving a residue of 80 parts of nitrogen. From the general complexion of these experiments it More or less must be obvious, that, although for reasons easily to be as- pera signed they are not always to the same extent in the de- case by respiza- erease of air from respiration, it is still sufficiently demon- 4": strated, there is an absorption of oxigen in every case more or less. Certainly they must be considerably influenced by the state of the animals at the time of the experiment, some of them being more recently caught, and more healthy than others, as well as by the difference in the capacity of the lungs. The noisome effluvia continually emitted from their bodies by transpiration must have its effect, as it appears in no but not the case can the whole of the oxigen gas be absorbed in respira- “"!* tion. Therefore the carbonic acid gas formed, and these ef- fluvia together, terminate their existence, when there some- times remains even more oxigen than in common air. When Less oxigen animals die in confined portions of atmospheric air, itis also ries true a portion of the oxigen remains unconsumed, but in much less. proportional quantity. It will be seen in the ex- Nitrogen left periments with oxigen gas nearly or quite pure, a proportion . Eee of nitrogen has been left, in some instances more than ies 5S a fifth of an aliquot part of the whole gas tried, which, doubtless inust have arisen from the introduction of some atmospheric air, when the animals were passed through the, quicksilver into the jars, and I have no doubt a little is given out from the lungs. at I should have been content with giving these experiments Oxigen absorb- as they are, and suffering such inferences to be drawn from ed in respira- them as their tendency may warrant, being perfectly satis- fied in my own mind the absorption of oxigen is iully proved; 140 not converted into carbonic acid. Oxigen ab- sorbed by the bleed. ON RESPIRATION. ; proved; particularly from having always observed, when mice are put into this gas, the greatest decrease 1s always in the first few minutes. .And that neither by analogy nor experiment have we any right to assume, that the decrease takes place from the condensation occasioned by the con- version of the oxigen and solid carbon into carbonic acid gas, as supposed_by Mr. Ellis. Indeed [ do not think I should again have commented on this subject, but by being forcibly struck with the most singular perversion (LI dare ‘not say intended) of one of the celebrated Mons. Bichat’s experiments quoted from his work, ‘* Recherches sur la Vie et la Mort,” the original of which Thad an opportunity of seeing for a short time only, in support of this new theory, and which was intended and does absolutely go to demon- strate the absorption of the oxigen gas by the blood. It was my intention to have repeated this very interesting experi- ment; but being about to institute others, having some re- lation to it, when opportunity will permit, I have preferred | delaying it till that time. Thus stands the quotation in Mr. Elhis’s work on Germination, &c. p. 128. ** Air, says «Mr. Bichat, thrown into the vascular system, quickly « brings on agitation, convulsions, and death. (P. 179 of _ « Mr. B.’s work). By forcing air through the windpipe “¢ into the lungs with a syringe, and confining it there, he “has made it to enter into the blood vessels, which imme« « diately brings on agitation and exertion in the animal. «© And if an artery in the‘Jeg or foot be now opened, the ‘ blood will spring out frothy and full of bubbles of air. «If hidrogen gas has been used, the bubbles may be in- “ flamed, and when this frothy blood has flowed thirty se- * conds, the actions of life cease, and cannot be again re- << stored, even although fresh air be applied. (P. 303 of ¢ Mr. B.’s work).” I regret I have not now by me Mr. B.’s work, and I have not heard of either that or his Anatomie Générale being yet translated. Ihave however now before me a very copious analysis of it, which will be quite sufficient to enable me to point out the application Mons. Bichat intended by the above passages. But first I hope it will not be deemed im- ° proper, if I depart from the subject for a moment. As an enthusiastic e Lay cal - ON RESPIRATION. 141 enthusiastic admirer of physiolagical pursuits, I have expe-= rienced the greatest delight in reading an account of Mr. Bichat’s labours. I was astonished at the irrisistible man- Bichat, ner in which his experiments aud demonstrations carry con- viction to the mind; aud I cannot but deeply lament, in common with every lover of science, that so sublime and ar- dent a genius should be suddenly cut off in the midst of his useful and instructive career. I believe none of his works have yet been translated into English, nor the originals much diffused through this country. I hope however, if not already done, no long period will elapse before so de- sirable an object is accomplished. His physiological and anatomical writings deserve to be most carefully studied, particularly by those of the medical profession, ere they can be duly appreciated. Iam by no, means competent to decide upon the merits of performances executed by so ex- traordinary a man, I can only say, if upon a careful peru- sal they shall leave upon the minds of others the same strong impressions, that a partial knowledge of them has left upon mine, they can never be obliterated ; and I have no doubt _ef their occasioning so much ardour and discussion in the ‘progress of these pursuits, as will eventually be productive of the most beneficial consequences to mankind, by fixing the structure of medical science upon the immovable basis resulting from the combination of the most liberal and en- lightened theories with the most decisive facts and practical experience. Hence shall arise out of the ashes of unstable and departed hypothesis a permanent superstructure, invul- nerable to the attacks of mere speculatists, and which, though solid and immevable in itself, shall still admit of being improved and beautified by the labours of present and future artists. I trust I may be excused for thus taking the liberty of paying this trifling tribute of admiration and esteem to the memory of the ever to be lamented Bichat, though he was never known to me but through the medium of his writings. From the sketch ef his life, which I have. read, 1 may be confident in stating, that my veneration can- not be misplaced on him as a man, however my ability to understand and value him as a writer may be readily called jn question—that he was one of those, who will ever have a first 142 Mr. Ellis as- serts, that no oxigen enteis into the Rlood, Bichat found . hidrogen gas enter the blood. throngh the lungs. Air injected juto the blood wessels kills by its mechanical action, The deadly ef- fect does not take place iu the heart. Death of the heart the efieck ON RESPIRATION. first rank among the illustrious dead, will not I believe, be disputed. But to return to the purpose, fer which the above quota- tion was made. It is necessary, for the illustration of my proposition, I should make a short extract from Mr. Ellis’s work. At-page 198 he says: ‘* We have endeavoured to “* prove, that no gasses either exist in the blood, or can be “¢ transmitted threugh the vascular and cellular structure in- “¢ terposed between the air and that fluid in the lungs: con- “ sequently no oxigen can enter into the blood, to unite “‘ with its supposed carbon; nor, if such union did take «¢ nlace, could the carbonie acid be afterward expelled from «* that fluid.” Now is it not wonderful, that Mr. Ellis, writing thus, should make the before mentioned extract from Mr. Bichat in proof of it; which, stead of being so, goes directly to coitradict it? for in the avalysis of his work before me, af- ter stating the injection of hidrogen gas into the lungs, and keeping it there by a ligature on the trachea; and demon- stratiig its passage into the blood by opening an artery, and presenting a lighted taper to the air bubbles formed on the surface the blood which issues out; he thus continues: ‘© This affords a proof of the passage of air into the blood “ THROUGH THE LUNGS, in ADDITION ¢éo that of seins Ten “© spiratton, &c. The injection of air mto the veins or arteries occasioning the destruction of animal life can be no proof, that oxigen gas is not chemically absorbed by the biood in the lungs in healthy respiration; for in the blood vessels it evidently kills by its mechanical action only. Neither does the deleterious effect take place in the heart, as has been supposed; for Bichat bas shown, and indeed I myself have often seen, that the heart beats long after the signs of animal life are extinct. Air injected into the carotid ‘artery has the same effect as in the veins, with the addition of agitating the heart by con- tact as a mechanical body. And aiso if injected into the vena porte, but taking a much longer time before the ani- mal is affected, as the capillary circulation of the liver pre veats its arrival sosoon at the brain. And hence it has been concluded, that the death of the heart is the effect, and not the rt) na ON RESPIRATION. 145 the cause of the death of the brain. But the injection of of that of the aw into the crural artery never proves mortal, though it oc Prin. casions a paralysis of the muscies. Mr. Ellis could not surely for a moment suppose, that Nonabsorption because the absorption of oxigen gas by the biood in the lungs in healthy respiration is conteided for, therefore the game must take place with respect to hidrogen, or any other miephitic gas; or else with-neither: and yet such is the in- ference naturally presenting itself upon comparison of the above two quotations. As an attentive observer of the chan- ges ensuing in blood by its conversion from venous to arte~ rial, 1 am firmly persuaded, it is by chemical affinity alone, and not a mere mechanical absorption, such as would take place with water and oxigen or carbonic acid gas. It is only by pressure that hidrogen gas can enter the blood vessels, for in natural inspirations of that air no such effect can be discovered as that by the lighted taper; and judging from analogy we may conclude the same of the rest of the mephi- tic airs. Besides, it has been ascertained, that the whole is again thrown out of the lungs unaltered in the next expira- tions; and, as we have already seen, when oxigen gas is breathed, it is far otherwise. The blood, in circulating through the pulmonary vessels, of mephitic gasses by the blood in the lungs no proof, | that it does not absorb oxigen. Manner in presents itself to the air cells to receive its accustomed sup- which death is ply of oxigen; and when noxious airs are respired, or respi- breught on from a defect ration suspended, being continually disappointed it still of oxigen in flows towards all the organs of the body, and their arteries the lungs. become filled with black blood, till at length the animal be- comes asphixated : that is, the volume of the blood returned by the veins is increased; the venous blood not having the power to stimulate the organs of secretion, their functions remain uaperformed ; the matter that should be secreted re- turns therefore with the mass; while the venous blood, cir- culating in the bronchial arterie produces the same deicte- rious effect on the lungs, as on the other organs; and from the detiviency of oxigen, which is to the air cells what food is to the stomach, the cells cease to be expanded ; and at length, by producing a similar effect on the walls of the heart, so enfeebles its contractions, it cannot surmount the resistance set up by the lungs. And, as Bichat energeti- 3 } ; : cally 144 Resuscitation, Oxigen gas a powerful auxi- Hiary of resus- eitation- State of the sanguineous system in mice killed in oXi- gen, ON RESPIRATION? cally expresses it, when once the black blood, (that is the blood which has absorbed no oxigen) has penetrated the heart’s tissue, it is dead to sympathy, as well as direct sti- muli. Hence it may be interred, that, 1n suspended ani- mation from drowning or otherwise, till this fatal effect takes place upon the heart, it is capable of sympathizing in the excitement of the lungs by inflation: that is, it continues susceptible of the impression or action of the oxigenated blood. This knowledge ought to bea still more powerful inducement with us, to persevere in our efforts to restore our fellow beings when they have been by any means acciden- tally suffocated: and perhaps one of the most powerful auxiliaries we could make use of for this purpose would be the judicious application of pure oxigen gas for the infla- - tion of the lungs, which must evidently be more effectual than common air, and might always be kept in readiness over water in the usual places apprepriated for containing | the proper resuscitative apparatus, and highly creditable te the philanthropy of some of the inhabitants is it to say, that in this town there are several. Upon examining the lungs of the mice which died in oxi- gen, their vascular substance appeared to be engorged with dark red blood; and on observing the liver I found it to be much lighter coloured than usual, no doubt from deficiency ‘of blood. It would naturally have been expected, that, and of those killed in other gasses. An atmos from the action of the oxigen gas on the blood in the lungs, it would have appeared of a-florid colour: but in conse- quence of the great excitement, occasioned by the rapid ab- sorption of this gas in respiration, to the lungs, intercostals, and diaphragm, the mechanical action of the lungs must have first ceased, and several rounds of circulation must af- terward have gone on from the continued action of the heart, which I have sometimes known to beat nearly an hour after the discontinuance of the animal functions. In those which died in atmospheric air, nitrogen, hidro- gen, and carbonic acid gasses, J invariably found the lungs collapsed and empty, and the liver full of blood. The cir- culation in these cases being more suddenly interrupted, time enough was not allowed to fill the vessels of the lungs. The effect of oxigen on animals placed in it appears to be ON RESPIRATION. be similar to what occurs when they are exposed in a room of atmospheric air heated many degrees beyond the tempe- rature of the body: the excitement in each case is equally “great; and, if it continue, death will be eventually oeca- sioned in both from the same cause, the too rapid absorption of oxigen. In heated air the circulation is proportionably quickened, and a larger surface of blood is of course pre- sented to its influence. And the action by chemical affinity between the blood and the oxigen is no doubt in such cir- cumstances considerably increased. 1 have sometimes seen dogs sleeping by a large fire excited to such a degree, as at length to respire with great difficulty; the action of the diaphragm has been very violent; and they have in conse- 145 phere highly heated acts like oxigen gas. quence awoke, and been compelled though reluctantly to_ move. But the sect deleterious and noxious of all the gasses to animal life is the oxigenized muriatic acid, If it oe pure and recent, animals die the instant they are put into it, and the effects upon the thoracic viscera are most dreadful. In examining some mice suffocated in it, 1 found the _ Jungs converted into a dark purplish brown pulp; the heart, auricles, and vessels, become black, dry, and corrugated ; the membranes and other parts nearly destroyed; and the blood coagulated into a mass like an electuary. The brain too appeared much inflamed when compared with some that had died in a different manner. But in so small an animal the symptoms cannot be very accurately traced; nor can any other than general observations be made, without consi- derable difficulty and patience. Death by this means seems to be synchronous; thatis, the action, of the acid gas is not referrible to any particular organ, but kills the lungs, heart, and brain, all at the same time. T have often inspected animals suffocated by’ drowning, and have always found the lungs distended by a quantity of air _ remaining im the cells; and as this must consist of carbonic acid and nitrogen, might it not be proper, in cases of sus- pended animation, to draw it out of the lungs by an ex- hausting syringe, previously to the inflation of them with the oxigen gas? By the politeness of Mr. Stebbing I was permitted to i Vou XXIV.—Ocr. 1808. L examine Oximuriatic acid most dele= terious. Its effects on mices Drowned ani« mals, Lungs of per- sons strangled, 146 Superiority of the camera lucida, Mr. Shel- drake’s state- Ment too un- fayourable to it, @N THE CAMERA LUCIDA. examine the lungs of one of the two criminals, who were executed here on the 3tst ult. fer murder, and delivered to him for dissection. The cells contained a considerable quantity of air; and from the room the lungs appeared te take up in the thorax, I should imagine, they must have been nearly distended to their usual size, as in a living state. Undoubtedly there must be some variation in the appear- ance of different subjects; and, whether vitality cease sud-- denly, or in a more gradual manner, the effect on the lungs will in a great measure be determined by it. Having extended my remarks on this subject farther than T at first intended, 1 shall defer entering upon vegetation &c. till a future opportunity. ib. @ On the Camera Lucida. Ina Letter from Mr. R. B, Bate. ‘‘ The camera lucida is portable in a very small compass; ‘* it represents objects with more brilhancy and distinct- ‘© ness than the camera obscura; and it represents them “ either simgly er m combination with perfect truth and “ correctness of perspective. What disadvantages has ‘© it then to counterbalance these particulars, in which «¢ it is evideutly superior in a very great degree to the ** camera obscura?” ‘ See Supplement to Vol. XXIII of Nicholson’s Journal, page 373. — To Mr. NICHOLSON. SIR, YY our correspondent, Mr. Sheldrake, after passing the above encomium on the caniera lucida, has put the query which follows, and answered it; but in a manner ill calcu- lated to lead toa fair conclusion upon the subject of his in- vestigation. And, as [have found the camera lucida not only less deficient im the points to which he refers, but te posses many advantages which he appears to have overlook- ed, I feel induced to state them in a more familar manner, thar ON THE CAMERA LUCIDA. 147 than has hitherto been doné; being persuaded, that some of fy, has advan- these advantages are not generally known, and likewise in- tages not ge- fluenced by a wish to see ‘justice done to the merit of an vigeally Epona invention, which deserves to be better tinderstood, and which is peculiarly admiirable for its correctuess and sim- plicity. You very justly remark, that, in using the camera lucida, Method of it is certainly intended « the tracing should be made upon te that part of the paper, where the picture and point of the pencil can both be seen coincident ; and not theta copy should be taken in the manner described by Mr. Shels _ drake.” But it is matter of regret, that you should not The manage- _ have enlarged upon the effect of varying the position of the ac is fe eye; in Be ashing which the ingenious inventor hay nat described mi- been sufficiently mmute, as is strongly instanced by the SUT CUP HS Rs misconception manifested in the case before us. Mr: Sheldrake evidently confines the camera lucida to the Mi. Shel. purpose of bringing the reflection of some of the objects ae upon the upper part of the paper, for the approximated the instrument convenience of copying them upon the lower pirt; instead S™Onee4s- of placing his peneil among the images themselves, and ‘ yendering them permanent,” by tracing their outline at once; as himself states to be done in the camera obscura: As Mr. Sheldrake seems sensible of the advantage of: moving his eye to the right and left, it is the more extras ordinary, that he should confine himself to that motion, when the transverse motion of the eye is the most obvious= ly important: ‘In copying a landscape the instrument i8 to be fixed UPON Proper mie a steady table or board, on which a sheet of paper ieee: stretched, and the prism brought over the middle of it! the Open face of the prism is to be placed opposite the centre of ' the view; the black eye piece, or stop, being in a horizon= _ tal position, is to be moved till the lucid édge of the prism intersects the eye hole. The eye should now be brought close to this opening, and, upon looking through it verti< tally. towards the piper, a perfect copy of the view will aps pear reflected upon it, and the reflected images will be large in proportion to the elevation of the prism. The eye hele should now be drawn farther off the prism, so as to Le leave 148 Management of the eye, Field of view. Method of ob- taining a clear sight of the imageand pen- cil at the same time, Directions for copyibg a near er very tall ebject, 7 ON THE CAMERA LUCIDA. leave a.vepresentation of the object barely distinct, for the, more complete command of the pencil. The whole. apparatus remaining stationary, it will be found, that, by moving the head so as to carry the eye far- ther over the prism, and. looking inwards, the view will be continued upon the lower part of the paper; and by draw- ing the eye off towards.the edge ofthe prism, and looking the contrary way, the view will be continued upwards: thus the reflection of every object comprised within an angle. of 45° in height and depth will in succession be distinctly seen ; and by a diagonal inclination of the eye towards the right and left a horizontal compass of the landscape equal to ap an- gle of 80° may also be obtained, and few will be dissatisfied with this field of view. The pencil may now be Sohne in following the out- line of the images, and, if their brightness should any where impede distinct vision of the former at the point uf coinci- dence, a slight motron of the eye towards the edge of the prism will obtain it, and vice versa when the image is not sufficiently distinct. It may not be amiss to recommend generally the near edge of the prism to be kept in a Ime with the pencil and the image; for which purpose it will obvi- ously be necessary to move the head in a direction opposite to the motion of the pencil, that the eye may follow it, and keep it in coniact with the lower edge of the picture, or rather, the edge of that part of the reflection which is at the instant visible. When the instrument is used in copying a near ox very “tall object it may occasionally be found, that, in following the image towards the upper part of the paper, the eye will be ast ome with the origmal reflection, which is coloured -and inverted; it will then be necessary to enlarge the field of view, by turning the prism upon its pin, slightly inclining its face upwards, and depressing the near edge of the stop ; which may be done without inconvenience, for, while the pin is strictly confined to a motion in that direction*, the * To ensure the confinement of this motion to the vertical direction, a small clamp for the top of the outer stem will be found useful; this may be tightened as soon as the elevation for the prism is determined on, and will answer to prevent the innes stem from sliding down or turning reund. images ON THE CAMERA LUCIDA. 149 images will not be in the least shifted from their places on the paper, which is a great advantage belonging to this ine strument. A much more important advantage peculiar to the ca- Peculiar ad- mera lucida is the essential benefit a young artist may de- hoannce tall, rive from a limited use of it. For instance, to have the out- io the student, line of one or two objects, situate near the middle of the view, as reflected by the prism: and afterwards to look di- ‘rectly at the view itself, using the upper edge of the prism as a guide for the point of observation. His eye and judg- ment may then be exercised in determining, by this outline, the relative magnitudes and distances of the remaining ob- ‘jects; occasionally referring to the reflection of them in the prism for their true situations i comparison with those his judement has assigned them: and these corrections, atten- tively observed,seem eapable of affording the most valuable aid in cultivating a delicacy of discrimination. ‘The finish- and to the ed artist will also find a great economy of time, upon ex-“"** tensive and complicated subjects in particular, by using the instrument in determining the situations of so many points as he may deem important * and which the camera lucida is allowed to give ‘¢ with perfect truth and correctness of per- spective.” Though hitherto omitted, it is proper to notice the fre- View obstruct. quent impediments to an extent of view, arising from the ets _ projection of near objects ; parts of the head-dress in par- ; ; ticular are sometimes unsuspected obstructions, and the brim of the hat the most formidable of all. Dr. Wollaston has briefly adverted to the method of en- An object ray Jar ging a drawing, or delineating minute cbjects as magni- sek aida fitab ei ietasne the eye piece to a vertical position aad Pet taeieak docking dizitt at the object through the eye-hole and the lens, which must be turned up likewise to the samme position; © the paper and pencil then appear reflected in front of the | object, more or less distinctly, according to the quantity of prism exposed (o the pupil: : and a delineation of ihe object may be obtained large in proportion to the magnifying power of the glass ite the surface of the paper occupied. To this 1 beg to add, that a compound microscope may be 4 compound psed in the same manner, but more conyeniently with the Microscope Pt _ may be used horizontal 150 ai CONSTRUCTION OF A VOLTAIC Ae eae in the same horizontal position of the eye hole, by bringing the micro- pes, egies scope to the same position, and the face of the prism close . to its first eye glass. A telescope may likewise be employ- ed; having previously removed the head or cover, the face of the prism must be brought into contact with the eye glass, to which it serves as a diagonal eye piece : a distant object i is then approximated, appears reflected upon the pa- per as before, and may be delineated in a manner at once ples ising, novel, and correct. r# ‘The camera These combined advantages, and above all, the truth of lucida . superiorto. the reflected image under every circumstance, give the ca~ it AN mera lucida a decided superiority over all other known con- : trivances for the same purpose. And if the hints I have of- fered should enable Mr. Sheldrake, or any of your readers, to derive farther gratification in the use of the instrument than they have hitherto received, or call to notice any un- expected purpose, to which it may be applied, I shall be happy in having contributed, however poorly, to that gras tification. I am, Sir, Poultry, 12th Sept. 1809. Your very obedient servant, R. B. BATE, XX An Account of some Experiments, performed with a View to ‘ascertain the most advuntageous Method of constructing a Voliaic Apparatus, for the Purposes of Chemical Resear chy By Joun Goons Cuiipren, Esq. Fi R. S*. epee Tor late interesting discoveries by Mr. Davy having battery desira- Shown the high importance of the voltaic battery, as an in- ble. strument of chemical analysis, it became a desirable object to ascertain that mode of constructing it, by which the greatest effect may be produced, with the least waste of power and expense. Battery after For this purpose, I made a battery, on the new method, _ * Philos. Transact, for 1809, p. 92, spit as . with BEST CONSTRUCTION OF A VWOLTAIC APPARATUS. 15] with plates of copper and zine, connected together by leaden the new me straps, soldered on the top of each pair of plates; which are '?°¢- twenty in number, and each plate four feet high, by two }, bus of 4 feet feet wide: the sum of all the surfaces being 92160 square st 92160 inches, exclusive of the single plate at each end of the bat- square inches. tery. The trough is made of wood, with wooden partitions well covered ule cement, to render them perfectly tight, so that no water can flow from one cell to another. The bat- tery was charged with a mixture of three parts fuming ni- trous, and one part sulphuric acid, diluted with thirty parts of water, and the quantity used was 120 gallons. In the presence, and with .the kind assistance of Messrs. Davy, Allen, and Pepys, the following experiments were made. fists) Experiment 1. Eighteen inches of platina wire, of 3!5 of Its effects. an inch diameter, were completely fused in about twenty seconds. | Exp. 2. Three feet of the same wire were heated to a bright red, visible by strong day-light. Exp. 3. Four feet of the same wire were rendered very hot; but not perceptibly red by day-light, In the dark, it would probably have appeared red throughout. Exp. 4, Charcoal burnt with intense sage, Exp. 5. Oniron wire, of about 35th of an inch diame- ter, the effect was strikingly feeble. It barely fused ten inches, and had not power to iguite three feet. — Exp. 6. _ Imperfect conductors were next submitted to the action of the battery, and barytes, mixed with the red oxide of mereury, and made into a paste with pipe-clay and water, was placed in the circuit; but neither on this, nor on any other similar substance, was the slightest effect pro- duced. Exp. 7. The gold leaves of the electrometer were not affected. Exp. 8. When the cuticle was dry, no shock was given by this battery, and even though the skin was wet, it was scarcely perceptible, Before I offer any observations on the inferences to be drawn from these experiments, I shall mention some ethers, performed, for the sake of comparison with the foregoing, with 15% BEST CONSTRUCTION OF A VOLTAIC APPARATUS, with an apparatus very different in size and number of plates from the one juft described. Couronnede — _L his second battery was precisely the couronne des tasses .tasses; plates of Sig. Volta, consistmg of two hundred pairs of -plates, ell each about two inches square, placed in half pint pots of surface 3200 common queen’s ware, and made active by some of the li- square inchess quo used in exciting the large battery, to which was added a fresh portion of sulphuric acid, equal to about a quarter of a pint to a gallon. rece! To state as shortly as possible the effects produced by this battery: ; Experiment 1. It decomposed potash and barytes readily. Exp. 2. It produced the metallization of ammonia with great facility. ‘ Exp. 3. It ignited charcoal vividly. Bap oa Tt catiae considerable divergence of the gold leaves of the electrometer. Exp. 5. -It gavea vivid spark, after pannel in action three hours. At the expiration of twenty-four hours, it retained sufficient power to mnetallize ammonia, and continued, with gradually decreasing energy, to produce the same effect, till the end of forty hours, when it seemed nearly exhausted. Satensiby ofthe From the resuits ef the foregoing experiments, which, electricity in- though simple and not numerous, I trust, are satisfactory ; ele g we see Mr. Davy’s theory of the mode of action of the vol- quantity with taic battery confirmed: he says (in his Paper on some che- oe a of mical agencies of electricity, sect. 9, after having shown the effect of induction to increase the electricity of the opposite plates) “ the intensity, increases with the number, and the quantity with the extent of the series*” Thisproved by That this isso, the effects produced on the platina ae iron oe wires, in the first and fifth experiments with the large bat- on perfect com tery, and the subsequent experimerts on imperfect conduc- ductors, tors with the small apparatus, sufficiently prove. The pla+ tina wire being a perfect conductor, and not liable to be oxidated, presents no obstacle to the free passage of the electricities through it, which, from the immense quantities given out from so large a surtace, evolve, on their mutual an- * Journal, vol. XIX, p. 55. nihilation, BEST CONSTRUCTION OF A VOLTAIC APPARATUS. 153 nihilation, heat sufficient to raise the temperature of the pla- tina to the point of fusion. With the iron wire, of 5th of an inch diametér, the ef- ang imperfect fect is very different, which is explained by the low state of conductors. the intensity of the electricity) sufficiently proved by its not causing any divergence of the gold leaves of the elecs trometer) ; iuphiaeh beions opposed in its passage by the thin ~~ eoat of oxide, formed on the iren wire, at the moment the circuit is completed, a very small portion only of it is trans- mitted through the wire. To the same want of intensity is to be attributed the total malbility of the large battery to decompose the barytes, and its general weak action on bo- dies which are not perfect conductors. The small battery, on the contrary, exerts great power on imperfect conductors, decomposing them readily, although its whole surface is more than thirty times less than that of the great battery; but in point of number of plates, it consists of nearly ten times as many as the large one. The long continued action of the small battery proves Importance of the utility of having the cells of sufficient capacity to hold having the cells : : j sufficiently ca- a large quantity of liquor, by which much trouble of emp- pacious, 4 tying and fillmg the troughs is avoided, and the action kept up, without intermission, for a long space of time, a cir- cumstance, in many experiments, of material consequence. Beside this advantage, with very large combinations, a cer- and some dis- tain distance between each pair of plates is absolutely neces- ae sary, to prevent spontaneous discharges, which will other- plates, wise ensue, 2ccompanied with vivid flashes of electric light, as I have experienced, with a battery of 1250 four-inch plates, on the new construction. And here I beg leave to mention an experiment, which, A;gument fer _ though not directly in point, cannot be considered as foreign the dissimilari- to the subject of this paper. It has been urged, as one eos Sere proof of the nonidentity of the common electricity, and clectricity done that given out by the Voltaic apparatus, that in the latter “”*”" there is no striking distance. That objection, however, oe must cease. I took a small receiver, open at one end; through perforations in the opposite sides of which were placed two wires, with platina points, well polished: one was fixed by cement to the glass, the other was movable, by - means { 154 BEST CONSTRUCTION OF A VOLTAIC APPARATUS. means of a fine screw, through a collar of leathers, and the distance between the points was ascertained by a small mi¢ crometer attached. This receiver was inverted over well dried potash over mercury, and suffered to stand a couple of days, to deprive the air it contained, as thoroughly as possible, of moisture. The 1250 plates being excited pre- cisely to the same degree as the great battery, mentioned in the beginning of this communica‘ion; and the little receiver Striking dis- placed in the circuit, I ascertained its striking distance to tance “02 ofan be 1, of an inch. That I might be certain, that the air in 7 Os aay the apparatus had not become a con ductor by increase of temperature, [ repeated the experiment several times with fresh cool air, aad always with the same result; byt perhaps jt will be objected, that the striking distance was so small, as not to afford a satisfactory refutation of the argument al- luded to, when it is considered tothow very great a distance, comparatively, the spark of the common electrical machine This distance can pass through dir. he answer to this is obvious: ine might be in- creased. wipi , : will increase; for we see throughout, the intensity propor- tioned to the number, and it probably may be carried te such extent, as even to pass through a thicker plate of air, Another proof than the common spark. ‘The great similarity of the ap- of then iden- Ae » : tity pearance of the electric light of this battery in vacuo, and that of the common machine, might also be urged as an ad ditional proof of the identity of their nature. Numerous The effect of this large combination on imperfect con- combination ductors was, as may be supposed, very great; but of the fused but little : ; ? . easy ee same platina wire, of which the four-feet plates fused eightcen inches, this battery melted but half an inch, though, had the effect been in the ratio of their surfaces, it should have fused nearly fourteen inches. Bect of the The absolute efiect of a Voltaic apparatus, therefore, apparatus in seems to be in the compound ratio of the number, and size pape of the plates: the intensity of the electricity being as the mypibe: & size. former, the quantity given out as the latter; consequeutly regard must be had, 1m its construction, to the purposes for which i itis designed. For experiments on perfect conductors, very large plates are to be preferred, a small nomber of which ae probably be sufficient; but where the resistance of crease the number of the plates, and the striking distance | . eee “ALTERATIONS OF THE SOLAR LIGHT. 15$ ef imperfect conductors is to be overcome, the combination must be great, but the size of the plates may be small; but if quantity and intensity Be both required, then a large number of large plates will be necessary. For general pur- 4 inches square poses, four inches square will be found to be the most con- 2 Convenient size venient size. Of the two methods usually employed, that of having the pjates joined copper and zinc plates joined together only in one point, tegstherin one : ike : point only pree and movable, is much better than the old plan of soldering f.aple, them together, through the whole surface, and hating them into the troughs: as, by the new construction, the ap- paratus can be more easily cleaned and repaired, and a dou- ble quantity of surface is obtained. For the partitions 11 T,oughs of the troughs, glass seems the substance best adapted to se- pad :wood"'s te eure a perfect insulation ; but the best of all, will be troughs hone made entirely of Wedgwood’s ware, an idea, I believe, first suggested by Dr. Gabington. XI. Report of a Memoir of Mr. Wassenrrarz, respecting the Alterations, that the Light of the Sun undergoes in tra- versing the Atmosphere. By Mr. Havy*. 7T HE class of phy sical and mathematical sciences having directed Mr, Laplace and me to examine a paper of Mr. Hassenfratz on the changes that the solar light undergoes in passing through the atmospher e, we shall proceed to give an account of it. The light of the sun being composed of an infinite num- The sun wari ber of rays of different tints, the union of which forms always appear white, we should always see it white, if it came to us in the bea aad state in which it is emitted fr om that body. But in passing affected in through the atmosphere it frequently undergoes alterations, passing vig that change its appearance, so that there are circumstances sphere, jn which it appears to us with its natural whiteness, and _ * Joumal de Physique, vol. LX VI, p. 856, OE aa eek. as others 7 a3 156 Object of the author to deter- mine the kind ALTERATIONS OF THE SOLAR LIGHT. others in which it appears yellow, orange coloured, or red. According to Mr. Hassenfratz these different effects depend in general on the state of the atmosphere, the difference of the latitude, and the elevation above the sea. As to the ul- timate cause of these phenomena, it was natural to ascribe them, as Mr. Hassenfratz does, to the suppression of a part of the rays of the solar light in its passage through the at- mosphere. Newton has.already announced this property of transparent mediums, to stop certain of the rays that enter them, letting the rest pass on; and this celebrated philoso- pher even remarks, that they are frequently absorbed one after another at different distances from the surface at which the light entered ; and he quotes for example the various tints exhibited in succession by a coloured fluid in a conical glass, which is placed between the eye and the light, and raised so as to have the thickness traversed by the visual ray continually increasing. Now Mr. Hassenfratz proposes to determine the number and kinds of rays, the suppression of which occasions the and quantity of various tints, that alter the primitive whiteness of the solar rays imtercept- ed. light. The means he has employed are founded on 4 rule given by Newton, to determine the colour produced by a eiven mixture of rays of different kinds taken trom those that compose the solar spectrum. It follows from this, that, if we can know the sorts of rays that the atmosphere takes away from the solar light, we shall know by necessary con- sequence the colour produced by the mixture of the species remaining, and we may judge whether this colour be the same as that, under which the disk of the sun presents it- self. Here we must observe, that the mixture producing a eiven colour may be more or less compounded, because a colour does not change, at least with regard to its species, by the addition of parts of the spectruin situate on each side at equal distances from the point congidered as the cen- treof thiscolour. For instance, if wc add to the green its two contiguous colours, blue and yellow, we still have green; and the wixture will remain green, if we farther add indigo and orange, one of which is contiguous to the biue and the other to the yellow. Nothing but direct experiment there- fore can indicate the species Bi rays absorbed in their pas« sage, ALTERATIONS OF THE SOLAR LIGHT. Lag sage, when the disk of the sun appears yellow, orange, or red. Mr. Hassenfratz concluded, that the observation of the This to bedone solar spectrum produced by the refraction of the prism. ri Cet any would lead him to his object, because, the spectrum being trum. necessarily incomplete from the absence of the rays inter- cepted 1 in their passage, the deter mination of the deficiencies in the spectrum would indicate these; and it might after- ward be ascertained whether the colour resale from a mixture of the rays remaining would be the same as that of the solar disk. é Mr. Hassenfratz cites several results of the Boreas BOO iscrcations made under the various circumstances of which we are made, speaking. Thus on the 13th of January, 1897, having ob- served the spectrum at ten o'clock in the morning, he found the violet wanting, with part of the indigo. Now accord= ing to Newton’s rule, if the violet be suppressed, with a cer- tain portion of the indigo, the remaining colours are those, which, by their mixture, produce yellow: and the disk of the sun appeared of the latter colour. Asa necessary con- sequence, the yellow of the spectrum was deeper than ordi- nary. he same day at noon, the sun was white, and the spectrum then had its whole extent. But at four in the evening the violet had disappeared anew, with a greater quantity of indigo, so that the. sun appeared of a deeper yellow than at ten in the morning. Lastly, at a quarter after four the spectrum was shortened on the same side, and in consequence the solar disk inclined to orange. Mr. Hassenfratz presented to the class several coloured Drawings of drawings of the solar spectrum, such as he observed them in the spectrum circumstances where it had lost more or less of its length. oe The drawings were made at the moment-of the experiment by Mr. Gerard, at the Polytechnic School. The author adds, that he has sometimes remarked the subtraction of effects of the subtraction of several rays in rainbows seen at 'Ys from the different hours of the day, which have exhibited varieties eee in the number or extent of the coloured arcs. ‘The experiments are interesting in themselves, because they serve to explain in a natural and satisfactory manner some phenomena, on which we had not any thing precise. They 1358 Cultivation of Wit trees. Medical Lee- tures. SCIENTIFIC NEWS. They deserve the attention of the natural philosopher alse from the influence these phenomena have in experiments relating to the decomposition of light. SCIENTIFIC NEWS. Me. van Mong; of the Institutes of France and Hol- land, is publishing a ‘« Theoretical and Practical System of Fructiculture, or Instructions for the Work of the Nursery. and Fruitgarden in the Order of the Months.” The exten sive correspondence of the author having brought him ac- quainted with all the improvements lately made in this branch of science by a great pumber of persons distin- guished for their education and talents, who have withdrawn from the fatigues of war or the toils of politics, er who; grieving at public and private calamities, or chagrined at the ingratitude dad injustice of mankind, have retired to forget their sorrows in the quiet enjoyment of their gardens, he has conceived he should be rendering a service to many, by making them more generally known: The work, which commenced in January last, and will finish with December, is on the prinerple of a gardener’s calendar, and will include every thing relating to thé culture of fruit. It will give in detail the whole management of ffuit trees in the nursery and in the garden, not frony books however, but from thé author’s own experience, and the cémimunicatrons of hré friends. ee Middlesex Hospital: Dr. SarreRrtey’s Course of Clinical Instruction at the Middlesex Hospital will begin the first week in November: the attendance on the patients will be continued daily, and Lectures will be given once a week, or oftener; when it may be necessary, at eleven o'clock: Mr. Carrwrronr, As- sistant Surgeon to the Hospital, will undertake such occa sional demonstrations of morbid anatomy, as may be re- quired for the illustration of the respective cases. The ob- jects of the Course will also be extended to such remarkable peeulieriaes SCIENTIFIC NEWS, 159 peculiarities in the diseases of children, as may occur in the Foundling Hospital. Dr. Youne will begin his Elementary Lectures on Che- Chemica! and mistry, Physiology, thé Practice of Physic, and the Ma- beep Lee- teria Medica, about the middle of December: he will deliver them on Mondays, Wednesdays, and Fridays, at 7 e’clock in the evening, throughout the season. St. George’s Hospital, and George Street, Hanover Square. On Saturday, October the 7th, a Course of Lectures on ygeaicat ana Physic and Chemistry will recommence in George street, Chemical Lec- at the usual morning hours, viz. the Therapeutics at eight; “oka the Practice of Physic at half after eight; and the Che- mistry at a quarter after nine. By Grorce Pearson, M.D. F.R.S. Senior Physician to St. George’s Hospital, of the College of Physicians, &c. Clinical Lectures are given as usual on the patients in St. George’s Hospital, every Saturday morning, at nine e’clock. —— Obstetrical Dr. Seurre will begin a Course of Lectures on the The- ectures. ery and Practice of Midwifery, and the Diseases of Women and Children, on the 3d of Oetober, at his house, Ely Place, Holborn, The notice received from Dublin, and given in our Jour- nal, No. 103, p. 939, that Professor Davy intended to give a Course of Lectures on Galvavism in that city, was erro- neous; it being incompatible with the situation and duties of that gentleman to lecture in any other place than in the Royal Institution, where the usual Courses must be in pro- gress at the very time mentioned in the said notice. eer CE To CORRESPONDENTS. Mr. Rootsey’s paper is obliged to be set aside, from my printers being unable to procure from the letter-founders the requisite types. Mr. Singer’s communication will appear next month. J.S. of Hatton-garden, is deferred on account of the en- graving. In the mean time I should be glad, if he would faveur me with Ins address. METEOROLOGICAL JOURNAL, : For SEPTEMBER, 1809, Keptby ROBERT BANCKS, Mathematical Instrument Maker, : in the Stranp, Lonpon. ‘mii paRoME.| Yee eae ae AUG. | tg Oe = a ie z EK. Bert heaped Poof ae CN = : Day of} 2] a! lie 5 9 A.M. Day. Night. al oe E=IRs : 296 | 58 | 60! 62} 52 29°80 Rain Cloudy 27 57161 | 63+ 541) 29°75. Ditto Fair 298 59 |611 67155 | 30,00 Fair Ditto “99° |.62)|65 1.71 | 62 | 30°08 Ditto Ditto 30. | 66 68) 73 |-62 | > 20;S@eei— Rain’ 4 Ditto * 31 63 | 62 | 66 | 58 29°85 Cloudy Ditto SEPT. 1 |} 60|621}641]57 | 26°80 Ditto Ditto 2 | 60/}64|69160] 29°68 Rain | Ditto 3 164 }65.171'|'59.1*. 29:60 Ditto . Ditto 4 64 | 64 | 69 | 58 29°62 Ditto + Cloudy 5 |63162168.1/58 | 29°54 Ditto_ ~ Ditto 6 | 64162168 | 57 29°52 Ditto Ditto 7.:.|62| 60167 |54|} 29°97 Ditto Ditto | 8 “''57 [59 1654 52"): 20°34 Ditto Ditto 9 .| 59} 61467 | 53 | 29°58 Ditto Fair 10 160160} 64{| 501 29°67 Rain. | Ditto DL $571 56 PaaS: |. -20°70 Ditto Ditto 12 56 | 56 | 64 | 47 29°78 Fair Ditto 13 , and 7; of the whole. In these experiments the number of successive ins fusions was from 12 to 14, and the quantity of water em- ployed at each infusion was ten times the weight of the ori- Action of re- ginal quantity of galls.: What is left is a dark coloured and agents onit. hard body, upon which alcohol and the caustic alkalis have no action. Muriatic acid, by being boiled on it, breaks it down into small pieces, and is itself tinged of a light brewn * Fourcroy, Analyse de Quinquina, Ann de Chim, VIII, 122, & alibi. Systeme, VI, 312. Davy, Philos. Trans. 1803, p. 237. Thomson’s Chein. V, 107. Aikins’ Dictionary, Art. Extract, p. 422. + Mr. Davy formed infusions, which contained between 1-7th and 1-8th of their weight of solid matter, Phil. Trans. 1803, p. 240, t Thomson’s Chemistry, I], 555. § Ann. de Chim, XVII, 11. f} Phil. Frans. 1803, p. 251. colour: ON VEGETABLE ASTRINGENTS. 207 colour; potash throws down a very minute precipitate from the acid, while the residue is rendered quite black, and strongly resembles charcoal powder; a circumstance which seems to show, that the blackness of charcoal is not neces- Blackness of diel: ‘ h ee . - 4 charcoal not sarily connected with the the process of combustion or oxid~ (5 ected ation. with oxidation. In forming infusions of galls it occasionally happens, that Green tinge of we obtain them of a bottle-green hue. Mr. Deyeux and ‘? infusion Mr. Davy both mention this as occurring in the latter in- fusions, where the same galls have had repeated quantities of water poured on them*; but it never occurred to me to observe the green colour under these circumstances, while, on the contrary, I have met with it in an infusion of fresh galls, where no shade of green could be observed in any of the subsequent infusions. It is attributed by Mr. Deyeux to a green colouring matter, which he enumerates among the constituents of the galls; while Mr. Davy ascribes it to not owing to the gallate of lime. My observations lead me to question oo “ the accuracy of this latter opinion. In the first place it seems an almost decisive objection to it, that, if lime water be added in small quantities to the recent infusion of galls, -so that the tan be not precipitated, the green colour is not produced ; yet in this case the lime must be employed in saturating the uncombined gallic acid, and thus forming the gallate of lime. In one of the greenest infusions that I ever procured, the oxalate of ammonia did not produce the least effect, while the subsequent addition of the most minute portion of lime water immediately caused the precipitation of the oxalate of lime. If to the infusion of galls pure pot- Effect of re- ash be added, the brown colour is at first rather increased, ees ne ia but after some time a shade of green becomes visible. The moving the effect is much more speedy and more decisive where the 8'een tinge. carbonate of potash is employed; a similar effect is pro- duced by lime water, except that the green is more of the gluceous hue. In all these cases the green colour is instantly removed by an acid; where potash has been einployed the fluid acquires a reddish tinge, and where lime water was used, a delicate violet. The green colour always disappears * Deyeux, ubi supra, p. 12; Davy, ubi supra, No lime found ON VEGETABLE ASTRINGENTS. by exposure to the atmosphere, and it is also removed by boiling, although in this latter case it is partly reproduced after an interval of two or three days, but finally disappears. ‘There seems to be an analogy between these changes, and the effect of acids and alkalis on many other vegetable sub- stances, they are rendered green by an alkali, and are red dened by an acid. But the resemblance does not hold good in every respect; for the alkaline mixture loses its green co- lour, although its alkalescent properties continue; and I have observed the green colour to be removed by lime and ammonia, while, on the contrary, I have obtained infusions, which haye exhibited the green colour, and yet by the test of litmus have proved to be decidedly acid.. The green co- lour, wherever it exists, is immediately destroyed by the in infusion of 2Cetate of lead*. ‘With respect to the existence of lime in galls, the infusion of galls, the experiments which I have made on the subject lead me to conclude, that, although it may exist in the gall-nut, yet it is not taken up by the water. Ihave added to the recent infusion of galls both uncombined oxalic acid, and the oxalate of ammonia, without any precipitate being produced. Ifthe ammonia be in excess a consider- able effect takes place, but this is to be ascribed to the union of the uncombined alkali with the tan. If the infusion of galls be kept for any length of time, it always becomes covered with mould, and a sediment also falls to the bottom of the vessel. ‘The moulding has been attributed by Deyeux, Trommsdorff, and others, to the pre- sence of mucus, as mucus is'said to be the only substance, which is capable of supporting this species of vegetation f. I conceive, however, that this opinion is not correct; and that, even if there be any thing in the infusion, to which the name of mucus properly applies, it is not the immediate cause of the formation of the mould. The muriate of tin, aud the solution of jelly are the two principal reagents, * T employ the term acetate of lead in the restricted sense, in which it is used in the new Pharmacopeia of the London College, where I may remark, the distinction which I pointed out between Goulard and. ce russa acetata is recognized, and the appropriate nomenclature adopted. Powel’s Translation of the New Pharm; p. 157. ft Ann. de Chem. XVII, 15; and Thomson’s Chem, II, 356, which ON VEGETABLE ASTRINGENTS: 209 which are employed in the analysis of galls, the firft being supposed to indicate the presence of the extractive principle, the latter of the tan. The accuracy of this deduction I shall hereafter examine, but admitting it for the present, I may observe, in the first place, that an infusion of galls, which; when recent, was copiously precipitated both by the muriate of tin and by jelly, after it has undergone the process of moulding, will be found no longer capable of being acted upon by the first of these reagents, while the effect of the second is very considerably diminished. Secondly, if suc- cessive infusions be formed from the same galls, it is only the first infusions, which are capable of moulding; and it is these only which form a precipitate with the muriate of tin and with jelly. Hence we may conclude, that the capacity of moulding is intimately connected both with that part of the galls which precipitates the muriate of tin, and also, though perhaps in a less degree, with the tan*. nai 3:1 * 1 think it probable, that by proper management, an infusion of galls Infusion of Might, by the operation of moulding, be deprived of all its tan, as well as galls might of what has been called the extract. I kept a quantity of the infusion ep al exposed to the atmosphere for several weeks, and from time to time de- fan by aauiee stroyed the covering of mould as it was produced. ‘Long after the in- ing, fusion ceased to be affected by the oximuriate of tin, the mould conti. nued to be formed, and the power of affecting jelly obviously decreased, until at length it did no more than produce a degree of turbidness with. out throwing down a precipitate. At this period, however, the whole of the fluid became so filled with the remains of the mould, and with the sediment which was deposited at the same time, that the éxperiment could not be pursued. Tremmsdorf, as I have neticed above, attributes the formesion of the mould to mucus, and even employs this operation to remove this substafice, in order to obtain tan in a state of purity. I could not repeat his process, because I was not in possession of any per fectly pure alcohol, which is essential to its success. I would be under- stood therefore as speaking with much diffdence, when I observe, that I doubt whether it will be found practicable. It gees upon the assumption of the two data, tliat the extract alone is rendered insoluble by the appli- cation of heat and by exposure to the atmosphere, and that the mucus alone is separated by the moulding, both which, according to my experi- Moulding not _ ments, are incorrect. Mr. Deyeux himself has observed (a), that the re- confined to sidue obtained by evaporating theftincture of galls, when dissolved in mucilage, (a) Ann. Chem, XVII, 16, Vou, XXIV--.Nov, 1809, P watet, 210 Two varieties of muriate Of tin: the muriate, and the oxi- nruriate. Tests of their being accurate- ly formed, Oximuriate preferable re- pe VEGETABLE ASTRINGENTS,. In speaking of the muriate of tin itis necessary to ob- serve, that ee exist two well known varieties of this salt, - which differ, both in the relation of the acid to the metal, and in the state of oxidation of the metal itself. The latter Is perhaps the more essential difference, and it is that to which their characteristic effects upon the oximuriate of mercury, and the nitromur‘ates of gold and platina, are re- ferred. Both the muriates of tin seem to contain an excess of acid, or to be in the state of supermuriates, but it will be sufficient at present to distinguish them by the titles of mu- riate and oximuriate of tin. The muriate is formed by simply boiling tin in muriatie acid, and preserving it care- fully excluded from the atmosphere, and keeping’ a small quantity of the undissolved metal immersed in the fluid. The oximuriate is procured, either by permitting tin to dis- solve in the nitromuriatic acid, or perhaps more aceurately, by forming a nitric oxide of tin, and then dissolving this oxide in muriatic acid; this latteris the method that I have generally adopted. In order to ascertain, that the fluids are accurately formed, it is proper to examine their effects upon the oximuriate of mercury, and the nitromuriates of gold and platina; the muriate of tin, in consequence of its strong affinity for oxigen, throws down from the first a gray powder, from the second, what has been called the purple powder of Cassius, and from the platina, a reddish brown precipitate. The oximuriate of tin has uo effect upon these solutions. I have not observed, that any difference has been noticed in the effects of these two muriates upon astringent infusions, nor indeed is it stated which of them has been employed*, yet their action is by no means identical. As I have found the muriate of tin a less delicate reagent for the different infusions than the oximuriate, I have employed the “%, water, is subject to mould ; a fact which I have had occasion to notice, and which seems almost incompatible with lis opinion of the connection be- tween the mould and mucus. I have also found, that Mi. Hatchett’s ars tificial tan is capable of moulding * Pavy, Proust, and others deyominate the substance upon which they operate the muriate of tin; but fiom the effects which it produced, 1 ap-: prehend it must have been either what I have styled the oximuriate, ora mixture of the two, : latter ON VEGETABLE ASTRINGENTS. ‘ 64] latter in my experiments. In operating with the oximue agent for as- rate of tin there is a circumstance to be attended to, which ae infu may interfere with the results; when the aqueous solution of this salt is very much diluted, it becomes insoluble, and a precipitate is formed, which in experiments on vegetable infusions might be mistaken for the effect of a combination but itis preci- of the oxide of tin with some of the constituents of the sub- ea aunene stance under examination. The precipitate seems in this case to depend upon the water removing a quantity of super- abundant acid, which is necessary to render the salt soluble in water*. Having had occasion to make frequent usé of the oximuriate of tin as a reagent, I wished to ascertain what degree of minuteness it possessed as a test for tan or extract, and for this ptirpose, an infusion was formed by macerating ear ieacy ag a quantity of finely powdered galls in eight times their weight of cold water for twenty-four hours. Portions of “this infasion were successively added to 10, 20, 30, 40, and 50 times their weight of water, and even in the last in- stance the oximuriate of tin caused a slight precipitate, but> no effect could be perceived when the infusion was mixed With 100 times its weight of water. The nitromuriate of tin seems to be nearly as delicate a test, and they are both considerably more so than the simple muriate. I have had occasion to refer to the effects, that are pro= Twelve suc: duced by subjecting the same portion of galls to a number Ameria of successive infusions, and f shall now describe these effects same galls at & _a little more fully. A quantity of finely powdered galls was atic si infused in ten times its weight of water, kept at the boiling heat for an hour, and then suffered to ftand until the follow- ing day, when the fluid was drawn off; the same quantity of water was then added to the residue, which was boiled as before, and the operation was repeated for twelve succes~ sive days. ‘This twelfth infusion was colourlefs, it afforded a0 precipitate with jelly or the oximuriate of tin; and only a slight gray tinge with the oxisulphate of iron. These in- - fasions were kept for a fortnight, and were then examined. The first infusion contained a large quantity of sediment, ahd was covered with a thick coating of mould. The 2d * Berthollet, Stat; Chim. i, 457. P 2 and > i) Successive in- fusions in cold water, ON VEGETABLE ASTRINGENTS, and following infusions, up to the 7th inclusive, were alse more or less covered with mould, and had deposited a sedi- ment, but the fluid was now in all of them transparent, and of different shades of brown. The remaining infusions, after, the 7th, had undergone no. change, their colour was very: bright, and in the two last, scarcely perceptible. A com- parative experiment was made at the same time with ano- ‘ther portion of galls, which was subjected to the same ope= Effects of re- agents, ‘Gallic acid more readily soluble than tan, ration, except that it was not boiled, but only suffered to, remain for twenty-four hours at the common temperature of the atmosphere. The cold infusions were generally of deeper brown colour, they continued to act upon the re= agents longer than the warm infusions, so that it was not till. after the 14th, that the effect of the iron ceased to be visi-. ble. Generally the cold infusions begin to mould sooner. than the warm ones, but I thought that they deposited less of. the sediment. The effects of the three reagents, jelly, ther oximuriate of tin, and the oxisulphate of iron, upon the in= fusions were noticed in every instance when they were firft formed; in the earlier infusions the precipitates were very copious, but their quantity gradually diminished, until frst, they were no longer produced by the oximuniate of tin, andy shortly after by jelly, but it required a considerable number of additional infusions to exhaust the whole of the gallic acid. If the infusions be formed as in the above experi-. ment, it generally happens, that after the 7th or Sth period, the oximuriate of tin ceases to produce a precipitate, jelly continues to be perceptible for one or at most two infusions | more, while the iron produced the black stain until the 12th, 18th, or 14th infusion. - When the three reagents mentioned above are added to. the infusion of galls at different lengths of time after its for-: mation, the iron is the first which produces an effect ;, while. the jelly and the oximuriate of tin commence later, and_ nearly about the same period. The gallic acid is so readily soluble in water, and it is detected with somuch minuteness by the oxisulphate of iron, that almost at the same instant that ihe galls are added to the water, does the fluid become. capable of producing the gallate of iron. I have uniformly found the effects of. these reageuts to follow this order, al-- though ON VEGETABLE ASTRINGENTS. 913 though it is generally stated, that gallic acid is less soluble than tan*, and it is upon tis principle, that Mr. Bigyins founded his process for ascertuining the relative proportion of tan and gallic acid in the different substances employed in the formation of leathery. The solubility of the tan and the extract, so far as their Tamand ex- presence is indicated by jelly and the oximuriate of tin, ap- peri oe pears to be nearly equal. This is also contrary to the gene- soltibility. rally received opinion{, but I ground my position upen the following experiment. A quantity of galls was employed in the state of coarse powder, in order that it might more readily subside from the infusion. The proportion of the galls, and the length of time occupied in the infusion, were gradually diminished, until 1 found, that by infusing the galls in fifty times their weight of water for only five mi- Hutes, a fluid was obtained, capable of forming precipitates with jelly and the oximuriate of tin, which were barely visi- ‘ble, but as far as could be judged by the eye, equal to each other. Beside jelly, the muriate of tin, and the oxisulphate of Other reagents ivon, there have been other agents employed in the analysis ™P!oye¢- of galls. Of these the principal are the sulphuric and mu- yiatic acids, the carbonated fixed alkalis, the aluminous salts, lime water, and the acetate of lead. The acids have Acids. been considered as acting principally upon the tan, and with this view have been proposed as a means of separating it from the other ingredients of the infusion§. They are, ‘however, less delicate tests than jelly; for I have found, in the successive infusions, that jelly still throws down a consi- derable precipitate, when they have ceased to act; of the _ two, the sulphuric is the more delicate. Nearly the same remarks apply to the carbonated alkalis and to lime water, Limewater. as to the acids ; they both throw down copious precipitates * Seguin and Chaussier, Journ. Polyt. 1V, 678. + Phil. Trans. 1799, 261. Thomson’s Fourcroy, III, 93. _} Davy, Phil. Trans. 1803, p, 234. * § The proposal seems to have been first made by Mr. Dizé, but Proust and Vauquelin both agree, that the tan may be completely separated by the acids, Ann. de Chim. XXXV, 37. frem ¢ Aluminous salts, Acetate of jJead. Tartarized an- timony. ON YEGETABLE ASTRINGENTS. from the infusion of galls*, but in the successive infusions, for some time after they have ceased to act, jelly still continues to produce a precipitate. Lime water has been proposed by Mr, Merat-Guillot as the most commodious agent for sepas rating the tan from the other ingredients in the infusions, in order to obtain it in a pure statet, and Mr. Murray seems to regard it as the least exceptionable processt. . The alu- minous salts, alum, the sulphate, and the muriate of alu- mine, have been employed to denote the presence of extract in the infusions§ : but whether they act upon the tan or ex- tract, they are much less delicate in their operation, than either galls or the oxides of tin. By successively diluting an infusion of a known strength, and examining it at differ rent periods with jelly, the oximuriate of tin, and alum, 1 have always found the effect to cease first in the alum. Sul- phate of alumine is rather more delicate than a saturated solution of alum, while muriate of alumine seems to be less go. ‘The most delicate and the most universal precipi- tant of vegetable infusions is the acetate of lead, which aets equally upon all the constituents, the tan, the extract, and the gallic acid, and removes them completely from the fluid, In the detection of the gallic acid it seems to exhibit even more delicacy thau the oxisulphate of iron. Mr. Vauque- lin, in an elaborate and valuable paper on the effect of re- agents on the different species of cinchonall, employed the tartarized antimony as one of his tests. I formed a satu- rated selution of it in water, and observed its action on the infusion of galls. The effect is very considerable, convert- ~ Ing, as it were, the whole of the fluid into a pulpy mass ; the precipitate subsides very slowly, but it is easily separated by a filtre, and leaves the infusion perfectly transparent and * Deyeux, Ann. de Chim, ¥ VII, 19. Proust, ibid. XXXV, 32. Although Mr. Deyeux first noticed the action of the carbonated alkalis ypon tan, he does not appear te have attempted to procure it in a state of purity by this process. Le + Ann. de €him. XH, 823. t Chemistry, 1V, 275 § Davy, Phil. Trans. 1803, p. 23°. ; {| Ann, de Chim. LIX, i113. Journal, vol. XIX, p. 106, 203 colourless, ON VEGETABLE ASTRINGENTS. ; 915 colourless. To this filtered fluid jelly and the oximuriate of tin were added without the slightest efect, and the oxi- sulphate of iron only produced a blackish green tinge. In this case it would appear, that the whole of the tan and the extract, and the greatest part of the gallic acid were re- moved by the antimony. In consequence of the readiness with which the nitromuriate of gold parts with its oxigen, I Nitromuriate thought of tryimg the effect of this reagent on the infusion or esis, of galls. Its first effect was to convert the brown colour of the infusion into a dull blackish green, and after some time a brewn precipitate was thrown down in moderate quantity. 1 was led by analogy to try the nitromuriate of platina; the and of platina. infusion was rendered instantly opake, and a reddish brown precipitate was formed. These observations on the effect of the different reagents Constituents upon the infusion of galls naturally lead to some conside- of the soluble rations respecting the constituents of the infusions, and also Ee us ef the galls themselves. The soluble part of the gall-nut is said to consist of four principal ingredients, tan, gallic acid, extract, and mucus. The distinct existence of each of these substances is supposed to be proved, either by our bemg able to procure it in a separate state, or by the em- ployment of seme tests which may recognize its presence. To the tan and the gallic acid, both these methods of proof Tan and gallic are, toa certain extent, applicable; they may, in some de-*°% gree, be separated from the other parts of the galls, and we’ are able to ascertain their presence by tests of the greatest delicacy. ‘There is reason to conclude, that, whenever jelly throws down a precipitate from a vegetable infusion, tan is present, and is the immediate cause of the effect ; although it is probable, that it is not tan alone which unites itself to the jelly. The existence of gallic acid is most distinctly proved; it may be obtained in a xtate of almost perfect pu- rity, and it may be detected by the oxisulphate of iron in a way that can scarcely be mistaken. But the proof cf the Extract. existence of extract is not so direct; it is confessed, that we are unable to procure it separate from the other parts of the galls, and therefore we are obliged to for m our opinion, ei- ; ther from the effect of tests, or from the observance of some changes that the infusions undergo, which are thenght not 10 ron yy ON VE@ETABLE ASTRINGENTS. to be referable to the other constituents. The circumstan. ces, that have been adduced to prove the existence of extract — in the infusion of galls, may be referred’ to the following heads. 1. When jelly has been added to the infusions, until it no longer produces a precipitate, the fluid will still be precipitated by the oximuriate of tin. 2. If an infusion of galls be exposed for some time to the atmosphere, and especially, if it be kept at an increased temperature, a part of its contents will be rendered insoluble, and will separate from the fluid. 3. If two portions of galls be infused in water, one for a short space of time, and the other for a longer period, they will be found to be difierently affected by the reagents; the quick iufusion being proportionably more acted upon by jelly, and the slow infusion by the oximu- riate_of tin, I shall consider each of these points indivi-. duatly, and shall examine how they authorize our conclu- sions in favour of the existence of extract. po The first of them I do not propose to controvert, and yet The whole of ate : copie é the precipi:are 1 thing it presents some degree of ambiguity, of which those ie ce who have written or experimented upon the subject do not Belen: more seem to have been perfectly aware. Iam disposed to be- ‘ jelly is added. Jieve, that the effect has been a good deal exaggerated. Ww hen we add jelly to the infusion of galls, it seldom hap- ¢ pens, that the whole of the precipitate is separated at once; a part of it remains suspended in the fluid, giving a greater cr less degree of opacity; ‘and if in this state more jelly be added, it will appear to produce no more effect, or even by farther diluting the fluid, to render it more transparent, and partially to redissolve the solid contents*, If however, in * Mr. Davy states, that in the addition of jelly to an infusion of gan, if the jelly be added in excess, part of the precipitated compound will be redissolved. In order to observe this effect the following experi- ment was tried. A quantity of a weak infusion of galls had about twice as much jelly added te it as I supposed would form the most per- fect compounds; a dense substance was precipitated, and the whole of. the fluid was jendered milky. Two equal quantities of this milky fluid, were put into separate glasses, to one an additional portion ef jelly was added, and to the other the same bulk of pure water. Both the fluids were rendered more transparent from the «fleets of dilution, but I did wot perceive that it was more so in one case than in the other, al- though the tan must now haye had abont ten times its proper quantity ef jelly added to it, ; : this ON VEGETABLE ASTRINGENTS. 21% this ‘case we defer the addition of the jelly, until the fluid shall have had time to deposit its contents in a solid form, we shall find, that a fresh quantity will be precipitated. If this operation be repeated, until the fluid no longer affords any farther precipitate with jelly, the oximuriate of tin will indeed still produce some effect, but not in general a very considerable one. Nor indeed does it- certainly follow, that this small quantity of precipitate ought to be attributed to the union of extract with the oxide of tin. Although the infusion has ceased to precipitate upon the addition of jelly, although the jelly was added in small quantities at once, and no more added than what seemed necessary, yet I believe that the fluid may still contaim both jelly and tan.1I found my opinion upon the circumstance, that in the successive addi- tions of jelly to an astringent infusion, the first quantity added unites with a large proportion of tan, and forms a more insoluble compound, than any of the subsequent ones; and that in proportion as we proceed, the jelly becomes in- corporated with less and less tan, and forms a compound less and less insoluble; until at length a substance is Compound of formed, which remains in a state of half solution, and which ir a ioe renders the fluid opake, without ever producmg a complete insoluble, precipitate. This kind of combination between jelly and tan may be inferred from some of the experiments, which I - mentioned in my former paper, and will be farther support- ed by the following considerations. The weight of the pre- cipitate formed by the addition of jelly to an astringent in- and differs ac- fusion is considerably influenced by the manner in which Aare ois ithe jelly is added, whether all at once, or in successive por- the jelly is tions. If we add together at one time the proportion of tan added. * ‘and: jelly which we suppose will mutually saturate each other, we procure a dense precipitate, which separates im-= mediately, and leaves the fluid transparent; whereas if jelly be added to tan in successive portions, a larger quan- tity/is necessary before the fluid exhibits an excess of jelly, the precipitate separates more slowly, it is in larger quan- tity, less dense in its consistence, the fluid retains a degree of opacity, and continues for a considerable time to deposit asediment. The following comparative experiment bears also upon the same point. An equal quantity of the ex- Wisneritnvents tract of rhatany and of prepared jelly, each in solution, were with rhatany. added 71% ON VEGETABLE ASTRINGENTS. added together, and a dense precipitate was formed, the fluid was left transparent, and nearly in a veutral state. The same quantity of jelly as before was then added to % of the former quantity of rhatany ; here a precipitate was thrown down, which was less dense and of a lighter colour, the fluid was vather less clear than in the former case, and it produced a slight precipitate by the addition of more rhatany. A third. experiment was then performed the reverse of the last. The origimal quautity of rhatany was added to 3 of its weight of jelly; the fluid was rendered perfectly opake, but the pre- eipitate very slowly subsided, and it continued for several days to deposit fresh quantities of sediment, but no farther. precipitate was produced by the farther addition of jelly. Beside this imperfect compeund of tan and jelly, which I suppese to be still retained in the fluid, it certainly ceutains gathe acid, and probably the neutral and earthy salts, which are found in the ga!!-nut. Iam not prepared to say, that it ts wpon any of these substances that the oxide of tin acts ; but I think, that we are justified in hesitating before we conclude, that the precipitate which is formed depends upon a substance, the existence of which is only rendered evident by the process in question. ” Precipitation The second proof, that has been brought of .the exist- hy exposure to p . : : a: . : the atmos. ence of extract in the infusion of galls, is the circumstance phere and heat of a part of the matter in solution being rendered insoluble qnestionable 1, exposure-to the atmosphere, or by the application of . ptoof of.the YY ©xposure te I > YF PPrS 0 presence of heat, a property which 1s thought to be characteristic of ai this peculiar substance. Here again, without disputing the fact, Iam inclined to hesitate as to the inference, and to doubt, whether the matter which separates be confined to this peculiar constituent of the fluid. If the imfusion of galls be evaporated by a heat not greater than that ef boil- ing water, a deep brown, brittle, transparent mass will. be obtained, which cannot be entirely redissolved; and if- the clear part of the solution be poured off, and treated in the same manner, an insoluble part will again be obtained; and this operation may be repeated for several times in succes- gion on the same portion of fluid with the same result. I have carried it to the fourth period, and I have observed no thange in the nature of the fluid, nor did its power of pro- ducing ON VEGETABLE ASTRINGENTS, ducing the insoluble residue appear to be diminished. . This experiment proves, that the supposed extract of an astrin- gent infusion canaot, according to the common opinion, be separated by one evaporation; and I think it may lead us to doubt, whether the effect is not rather produced upon its solid contents in general, than upon any one part of them. In confirmation of this supposition we may observe, that there are several processes, in which the tan itself is ren- dered insoluble by the addition of oxigen. Such is thought to be the method, in which the oxide of tin operates upon it; for although what is thrown down is a compound of taa and oxide, yet if the oxide be removed by the action of a dndrosulphuret, the tan still remains insoluble. The same kind of effect is also produced by the nitric and the oxi- muriatic acids, they throw down from the infusion of galls an insoluble compound, and deprive the fluid of the pro- perty of precipitating jelly. The idea, that insolability after evaporation was a specific characteristic of extract, seems to have origindted from the experiments that were performed by Mr. Fourcroy on the bark of St. Domingo; but the constituents of this bark are so different from those of galls, that we are not authorized in extending the ana- logy from one to the other, unless it be supported by some independent facts. So far therefore as 1 may be warranted to draw any conclusion on this subject from my own obser- vation, either of the effect of successively evaporating the seme infusion, or of the changes mentioned above, which are produced by long exposure to the atmosphere, I should conclude, that the tan itself is rendered insoluble in both these operations. The third circumstance, which has been adduced to prove the existence of extract, and especially to distinguish it from tan, is the greater insolubility of the latter while they both exist in their natural state. In analysing vege- table astringents we are told, that by subjecting them to a hasty infusion we shall procure the tan nearly free from ex- tract, while by continuing the infusion for a greater length of time we get a fluid which chiefly consists of this sub- stance. It is trae, that in applying water to galls, the first portion takes up more than the subsequent ones; but em which As) hs iS Not distin- guished from tan by its great. er solubility. Farther difi- eulty in distin- guishing tan froma extract, ON VEGETABLE ASTRINGENTS.« which is afterwards taken up does not seem to be materially different from what is first dissolved; it only appears, that in this, as in every other instance, the latter portions of so- huble matter are retained more obstinately by the insoluble part. The relative effect of jelly and the oximuriate of tin were always, as far as I could judge, exactly in propor- tion to the strength of the infusion, whether it formed in a longer or shortér time; in the infusions which were made the most hastily, both the reagents produced a precipitate, and however long the maceration had heen continued, still the effects seemed to be proportionate to each other. In« deed the results which are obtained, when we make a nums- ber of successive infusions, are directly adverse to the com- monly received opinion; for I found, as I have already stated, that in the last infusions jelly was frequently capa- ble of forming a precipitate after the oximuriate of tin, but that the converse never took place, It may be farther observed, respecting the distinetionbe- tween tan and extract, that the two reagents, which are the appropriate tests of each, jelly and the oximuriate of tin, both of them act powerfully upon the opposite substance, i.e. jelly upon extract, and the oximuriate of tin upon tan. With respect to the latter, it is known that Proust, who has exhibited so much sagacity on the subject of vegetable infusions and their action upon the metallic oxides, origine ally introduced the muriate of tin as a reagent for tan, and in his first experiments seems to have had no idea of its act= ing upon any other substance*. And with respect to the effect of jelly, whatever may be the body upon which it exerts its primary action, we find, that, when it has ceased to precipitate an infusion, what is then thrown down by the oxide of tin is’ at least m very small proportion to what world have been produced in the recent infusion. The _ facts which I have mentioned above, respecting the succes- sive infusions and the formation of mould show an intimate connexion between the two supposed substances, and ine deed scarcely permit us to draw any line of distinction, And the same idea will be still farther countenanced by con- * Ann. de Chim. XXV, 225. sidering OM VEGETABLE ASTRINGENTS. . sidering what are the characteristic properties of extract, as stated at fulllength by Mr. Vauquelin; for we shall find, that, so far from marking any essential difference between this substance and tan, they are equally applicable to the latter, and have been pointed out as even peculiar to it. Among these we may notice its solubility in water and al- cohol*, its strong taste, the effect of oximuriatic, nitric, sulphuric, and muriatic acids, of alkalis, and of metallic oxides tT. 231 Are we then to conclude, that the infusion of galls does Does the infu- not contain any constituent, to which the title of extract ought to be applied? or that, according to the original opi- nion of Proust, Seguin, and others, the infusion consists merely of tan and gallic acid? Upon this point I do not feel myself qualified to give a decisive opinion. Although I think the proofs, that have been adduced in favour of the existence of extract, are very insufficient, that we are not yet in possession of any method of accurately recognizing its presence, and that we are unable to say what are its cha- racteristic properties ;. yet I do not conceive, that we are warranted in denying its existence. There is indeed one fact which seems a strong presumption in its favour, viz. that, if we take two portions of the same infusion of galls, and saturate one of them with jelly, and the other with the oximuriate of tin, and let each of them remain for some time exposed to the atmosphere, until they have deposited all esta precipitates, they will then each of them afford * Tan is insoluble in perfectly pure alcohol, but it is realty dissolved in the alcohol with which our experiments are usually performed. _ t Itis stated, that extract is insoluble in ether; but this does not ap- ply to that part of the infusion of galls, which is acted on by the oxi- muriate of tin, for this reagent forms a copious precipitate with a solu- tion of the substance which is left by evaporating ether that has been digested on galls. This substance appears indeed to act as readily upon the oximuriate of tin as upon jelly or gallic acid, and I could not per- ceive, that it differed in any respect from the substance procured from the aqueous infusion of galls, except in being lighter coloured. Mr. Murray observes (a), that the colouring matter of saffron, which has ° heen regarded as a specimen of pure extract, is readily soluble in ether. fa) Chemistry, IV, 264. some sion contain nothing but Fo acid and tan? Fact in favour. of the exist- ence of extracts 299 ON DESTROYING THE ELASTICITY Of CORK. some precipitate to the contrary substance, the fluid which had been saturated with jelly will be precipitated by oxi- muriate of tin, and the fluid which had been saturated but this fr = with the oximuriate of tin will be precipitated by jelly. Yet from decisive. Shen we consider the compound nature of the fluid upon which we operate, and the variety of actions which may take place between the different reagents, we are not au- thorized even from this experiment to draw a decided infer ence in favour of the existence of two distinct substances. In entertaining doubts respecting the existence of extract as a distinct principle of vegetables, I feel happy to have my opinion supported by that of Mr. Murray * (To be concluded in our next.) a aa OB | es Question on the Preparation of Cork for Modelling. In @ Letter from a Correspendent. To Mr. NICHOLSON. SIR, How may the I Should be obliged to you, or any of your correspon- any cal deuts, if they could inform me of the method of deftroying strc ged? elasticity in cork; or what process it undergoes, to render it fit for modelling. If you recollect its haying been no- ticed in your Journal, by mentioning the volume you will equally oblige, Yours, &e. . R. Zs Ae’ ANSWER. Elasticity of T am not acquainted with the methed of depuis cork s /esitegaie © of its elasticity, but do not think my correspondent will find > much difficulty in discovering it by experiment.—From the texture of cork as seen under the microscope, it appears to * Chemistry, IV, 260. be DUSODILE, A NEW MINERAESs 233 be formed of woody fibres, with large interstices between them; and the elasticity of this substance is probably owing to the flexibility and spring of these fibres, and the difficulty with which the included air can be driven out from the cavities. It should seem, that, if the fibres could be and would pros rendered less flexible, aud the spaces partly filled, the whole peopel ae mass would become much less elastic. 'This may be tried ing its inter- by experiments on a small. scale. A slice of cork may be eee immersed in any hot liquid, which becomes stiff or brittle stance, by cold, such as melted resin, or its solution in alcohol, or glue, or gum water, or tallow, or siarch, or varnish, or any other material having the property first mentioned, and of which the list is not very numerous. The cork should be repeatedly compressed under the fluid, in order that it may imbibe it, and the whole allowed to cool before the cork is suffered to rise from the surface. Many trials of this sort may be made in a short time over a candle in an iron spoon, or in the small copper or iron vessels used for pastry ; and when the result is thus obtained, the operator must contrive and manage a larger apparatus according to his conve- hience, and the intended purpose. WN. XI. On the Dusodile, a new Species of Mineral; by Mr. L. Corpbirr*, ‘Vue new bituminous subftance, which I am about to 4 species of make known, was found in Sicily by Delomieu. The spe- hd cimens collected by that celebrated mineralogist arrived at Paris about ten years ago; and I then drew up a description of it under his eye, but various circumstances had prevent- ed me from publishing it. I shall now give it, adopting the method of Haiiy. # Journal de Physique, vol, LX VI, p. 277. The O24 Its state. Fssentiat cha- Facter. Physical characters. Chemical, ebaracters, Distinguishing eharacters, DUSODILE, A NEW MINERAL. The dusodile is in the compact state, and presents itself in the form of irregular masses, which fall into very thin leaves with great facility. The following are its character- istics. It burns with an extremely strong and fetid bituminous smell; leaving a considerable earthy residuum. . Its specific gravity is 1°146. With respect to hardness, it 1s easily cut, and reduced into. thin and very fragile leaves. The leaves are a little flexible. Its colour is greenish gray, It is opake; but the thin leaves become translucid by maceration in water. Tits smell, when breathed upon, is argillaceous. It is weakly combustible with a clear flame, and an insup- portable bituminous smell, resembling that elicited by frie- tion from the moft fetid calcareous stones. This smell isso strong, that we are not very sensibly affected by it till a few instants after the combustion, that is to say, when the smoke is completely diluted with the air. The burning of a very small piece is sufficient to poison a room for more than an hour. ' Combustion leaves a cons derable earthy residuum, form- img more than a third of the original weight. F By maceration in water its leaves separate of themfelves, and become not only translucid, but perfectly flexible. Dusodile is distinguishable from coal, by the latter being always of a black colour, more dense, and not changed by the action of water. From bitumens, whether solid or glu- tinous, as these, when heated gently, or rubbed between the fingers, emit a smell resembling that of pitch; and when burned leave searcely any earthy residuum, and give out no such smell as the dusodile. From the common elastic bi- tumen, as this has naturally a very perceptible bituminous smell, and is completely elastic; while the dusodile is in very fragile leaves, and emits an argillaceous smell when breathed on. ‘The elasiic bitamen too burns with leaving scarcely any residuum, and emitting a smell that is neither powerful nor diagreeable. From indurated elastic bitumen, SULPHURET OF LEAD, COPPER, AND ANTIMONY: © 995" bitumen, as this burns in the same manner as the preceding, its fragments exhibit no appearance of flexibility, and ma- cération in water does not in any respect alter their consis=- - tency. Its texture admits of no variety, being at the same time Varieties. compact and foliaceous: but it has two varieties of colour, greenish gray, and yellowish gray. This wineral is fuundat Melill, near Syracuse. It forms Where found, a stratum of no great thickness, extended between beds of secondary limestone. It appears, that attempts have been made to work it out, but they have not been pursued. 'This is certain, that the combustible fossil it contains has long been known in the country. The inhabitants give it dtfer ent names, some Name. calling it the bituminous foliaceous earth of Melilli, others devil’s dung. Both these names being equally improper, L have thought it necessary to frame one more suitable to mi- nera‘ogical nomensiature. That of dusodile, which from its Greek root implies fetid, was naturally suggested by one of the most remarkable properties of this new kind of bi- tumen, that of diffusing a detestable smell when burned. . XII, Memoir on the triple Sulphuret of Lead, Copper, and Anti mony, or Endellions By M. te Comte pe Bournon, FR. & LS ; IR HIS memoir was written chiefly as an answer to that Former me- printed in the first part of the Philosophical Transactions ge for 1808 f, in which Mr. Smithson its author, critici- by Mr. Smi the ses with as little justice as decency a former memoir of *™ _* Translated from the original, communicated by the author, and re- vised by him. + See Jounal, vol. XX, p. 332. Vou. XXIV—Nov. 1809. Q mine 226 SULPHURE? OF LEAD, COPPER, AND ANTIMONY. ‘mine on the endellion, which was printed in the first part of the Transactions for i804. It may appear strange, par- ticularly to those who have read Mr. Sinithson’s sharp cri- tique, that I have so long delayed answering it: but this delay was owing to one of those peculiar circumstances, happily not very frequent, which the mind is as unable te foresee, as prudence is to avoid. Chance made me ac- quainted with the criticism of Mr. Smithson, at the time of its being delivered to the secretary of the Royal Society, Dr. Wollaston, at whose house I then happened to be. He gave me permission to lock it over. Its nature surprised me; and this was all the impression it would have made on me, had I not immediately felt the disagreeable necessity I should be under of answering it, if it should be admitted into the Transactions of the Royal Society ; a circumstance, which I could never have supposed would take place, had T not had some particular reasons to be apprehensive of it. I requested in consequence Dr. Wollaston to favour me with a copy as soon as it should be printed; which he pro- mised me. Some time after, being at the house of the same gentleman, whom I was frequently led to visit by the esteem and attachment I felt, I found on his table the core yected proofs of this very paper, and then reminded him of the promise he had made. In fact he sent me a copy soon after. Happily I had in readiness the materials necessary to render my answer in some degree interesting, and pre-- vent my feeling the File iaica commonly attendant on Farther know. Writings of this‘kind. After had written my former ‘pa- ledge of the per, Thad obtained’a Knowledge of this substance, at that eompound sul- phuret obtain. time extremely searce, and considerably so even at present, ed by theau- that enabled me to render my account of it far more com- agi plete: and this indeed I had for some time had an inten- Account of it tion ef domg. A pursuit however in which I was then en- delivered tothe gaged, ‘and Shich T could net interrupt, did not allow me secretaryof the) Royal Society. iminediately to draw up the memoir I had ia contempla- tion: and it was not till about the month of September, in the same year, 1808, that I was. able to deliver it to the secretary of the Royal Society ; expressing at the same time my wish, that it might be read as early as possible, in order that at least it might obtain a place in the first part of the , T rasnactions SULPHURET OF LEAD, COPPER, AND ANTIMONY. 207 Transactions for 1809. This I had the greater reason to hope, as the time when ‘it was delivered was considerably before that, when the Royal Society recommenced its meetings.. After these took place however, I found it im- Soaible to get it read, notwithstanding I requested it re- peatedly. The time passed on, and 1 doa vot but fore- see, that it would have a powerful opposition to surmount in the committee of the Royzl Society, under which it would probably sink. I could not however make any other use of the paper. The first part of the Tyansactions was already filled up, when at length I learned from Dr. Wol- lagton, that rt had been read on the 4th of May. The time however still passed on, and nothing gave me reason to suppose, that the committee was taking any steps to have it printed, - On this subject it preserved the profoundest silence, which J endeavoured to penetrate in vain. It was Ordered to be not till the 23d of June, when its vacation was nearly ap- placed in the archives of che proaching, that I was informed of the fate, to which appa- Society : rently it had been condemned from the beginning, by a letter from the committee, in which it was said, that, not deeming it expedient to print it at present, it was ordered to be deposited in the archives of the Royal Society, Such are the reasons, that have hitherto prevented the but should publication of this paper, and at the same time have de- Bam been prb- prived it of the place it ought to have occupied. In fact it 03% seems, that, since the critique of Mr. Smithson, as unbe- coming as it was unfounded, obtained a place in the Trans- actions of the Royal Society, it could not without injustice refuse one of its members, whom it must have seen with regret to be the object of it, and who hitherto had been a zealous and approved coadjutor in its labours, the only in- demnification be could receive, that of demonstrating: the truth of his first assertions. [ appeal to the Members of the Society theniselves, who shall read this paper, and who know me sufficiently to do me the justice, I think, [ de- serve, whether I could on any wccoust have expected this singular proceeding on the part of its committee. @ 2 EXDELLION 2298 SULFHURET OF LEAD, COPPER, AND ANTIMONY. ENprELLIon. Part I. Endellion not When in the month of December, 1803, I presented te caopnatehe f the Royal Society a paper ou the triple sulphuret of lead, copper, and antimony, considered at that time as a simple ore of antimony, I thought it the more necessary, to fix the external characters of this substance, as Mr. Hatchett had just : shown by his analysis of it, that, so far from being a but a triple simple ore of antimony, it was an ore composed of three sulphuret. — sulphurets, those of lead, copper, and antimony, in which. the latter was not even the principal metal. The eharacter Jt was not in my power at that time however, to establish in Wai ae the character of the crystallizations of this triple sulphuret lizations could net at firstbe with ali the precision, that the case required, and that 1 aye epg °* could have wished, ‘This substance was then extremely scarce, ag it is even now. The crystals I was able to pro- cure being small, and with numerous sides, most of which “were irregular, did not allow me to depend sufficiently on the measures I wus able to take, to venture to fix in a pe~ Primitive crys- remptory manner the dimensions of its primitive crystal. ua Ail that IT could then deiermine positively was, that this ‘crystal was a rectangular tetraedral prism with square bases, but not a cube. Jn consequence [ satisfied myself with establishing this truth, without setilmg the dimensions of the crystal, It necessarily followed, that the measures given as those of the angles of incidence between the primary and secondary faces, as they could not be the result of a ealeulation the base of which was not. determined, must have heen merely taken with the graphometer, and conse- quently to be considered as approximations only ;-yet as ap= proximations having all the accuracy the instrument would admit, and the maccuracy of which could not amount to one degree. . Yesirons from that period of giving a more complete ac- count of this rare and interesting substance, and ascertain- ing at the same time in a more positive manner the form of its primitive crystal, I omitted no opportunity offered me of continuing to study it. Por such opportunities, as I could > SULPHURET OF LEAD, COPPER, AND ANTIMONY. 299° could not make them, I was under the necessity of waiting. At length I obtained the object I wished; I met with crys- More crystals tals, that I could measure with certainty, and had the satis- ain ay igs faction to find, not only that I could Jay before the Royal Society more precise observations respecting the character of the crystallization of this substance, but besides a more complete and interesting series of its varieties of form, and a much more complete mineralogical account of every thing concerning it. I had at the same time the satisface tion to find, that the first measures I gave, which were simply taken from the crystals with the instrument, differed from those now established by calculation only in that slight degree, which may be ascribed to the unavoidable want of accuracy in the instrument; a difference amounting. only to 30 in one of the three varieties I formerly gaye, to 19’ in a second, and to nothing at all in the third. This fact may serve as a proof of the near approach to accuracy obtainable by a little practice in using the instrument alone *. : I shall now proceed to give a complete acceunt of this substance, pursuing the method I adopted in my treatise on mineralogy, the first two volumes of which are just ot es lished. By way of preliminary however T shall observe, that as aj substances all substances, beside the explanstory terms that point out "equire an ap- their nature, and which are liable to change with the theory pee on which they are founded, require a proper name, iInvari- able in itself, and fixing their existence among natural substances, I have given this the name of endellion; which This named avoids the termination in ite, so frequent in the nomencla- — ture of mineral substances, and oS to mind, that the Side first specimens of this substance, ‘which engaged the at- tention of mineralogists, came from Endellion, in Corn- wall. , At the same time I avail myself of this opportunity, tO roumonite by Jameson, ” * Additional note. Since this paper was written, the measures ob- tainable by the ins‘rument have acquired much greater precision by Dre Wollaston’s ingenious discovery of the reflective goniometer, a discovery ef great importance to crystallegraphy. testify 230 Its characters. Primitive‘ crys- tal. \ Integrant molecule. Fracture. Spec. gravity. Brittleness, Flardnéss. @olour. Very fusible. Regulus. SULPHURET OF LEAD, COPPER, AND ANTIMONY. testify to Mr, Jameson how sensible I] am of the flattering but unmerited honour ‘he has ‘paid me in his inineralogy; by giving this pubsiance the name > Of bournonite. : EssentTran CHARACTERS of ENDELLION. Cryste lographicad. Primitive crystal. A rectangular tetraedral prism, the. bases of which’ are square, and: the height of which is t6 the side of the terminal faces in the proportion of $ to 5. ’ Integrant molecule. I have yet met with nothing to in- duce me to adopt any particular opinion of the form, that beiongs to the integrant molecule of this substance. Fracture. Irregular, and partially conchoidal. Made on crystals, and extendiy but a little way, it 1s perfectly couchoidal. ‘ Its lustre is very brilliant. Some of its acci+ dental fractures exhibit more clearly than many of those made by art the direction of its larntnze parallel to the faces of its primitive tetraedral prism; but these traces are als ways faint, and seldom perfectly marked. jie ¢* Physical. Specific gravity. 5°775. . Fragility.: This substance is very brittle. It is easily broken by the simple pressure of the nail, =) 0) Hardness. The’ endellion scratches carbonate of lime with considerable facility, but not without breaking, on ac- count of its great brittleness. Rubbed on paper it-leaves a blackish brown mark. Its penesr retains the metallic lustre. by Colour. Dark gray, Ae very shining I Hike that of pos lished steel, but a little more darks © . at Chemical. Exposed to the action of the blowpipe, it fuses the in- stant it is touched by ‘the flame, It remains for some ins stants afterward in a fluid state; and, if it were fused in a spoon, it might be cast like melted lead, the fluidity of which in this state it even:surpasses. A metallic regulus js easily obtained from it, of a dark gray ‘colour, very ag Hans: br uty SULPHURET OF LEAD, COPPER, AND ANTIMONY. 23) brittle, and the fracture is of a grain very fine and smooth. : Thrown into cold nitric acid, it dissolves pretty readily, Action of nitric and with effervescence. A real analysis is thus accomplished, 9¢i4 on it. The sulphur swims on the liquid, which holds in solution the copper and lead, and is of a green colour, and the oxide of antimony is precipitated in the form of a blue powder iuclined to gray. The endellion analysed by Mr. Hatchett gave for its Component component parts sulphur 17, antimony 24°23, lead 42°62, Pats. copper 12°8, iron 1°2: loss 2°15. Eventual characters. Phosphorescence. Placed on a hot iron the moment it Phosphores- begins to lose its red colour, the endellion diffuses a blue- “"™ ish white phosphorescent light, the imtensity of which ap- peared to me to vary in different specimens, Tapxe of the ENDELLION and its VARIETIES. Species. Varieties. Varieties. Triple sulphuret of | Crystallized in aj ( Primitive crystal. lead, copper, and perfectly deter- } its modifications antimony, minate Manner. and varieties. Endellion, Pure. Mixed irregular: ly with sulphu- In the compact | J ret of zinc, — state, Mixed irregulare ly with yellow sulphuret — of copper and iron. FF Descriprion‘of the DIFFERENT VarRiETiES of the Ene Description. DELLION. Of a determined crystalline form. The perfectly determined — form is that in Crystalline. which this substance has hitherto most commonly occurred. The surface of its crystals has a very shining lustre, which ean be better compared to nothing than to the rhomboidal oxide of iron of the island of Elba, oligist iron of Haiiy. This lustre however is exceeded by that of their fracture, . whea Where found. in the eome pact state. 4 SULPHJRET OF LEAD, COPPER, AND ANTIMONY. when itis recent. The crystals are difficult to determiae, both on account of the great number of faces they fre- quently exhibit, and of the irregularity of these faces, They consequently require a great deal of attention on the ny of the observer, to be perfectly ascertained. The éndeliion in a state of completely determined crys- tallization was first observed in Cornwall, in the mine of Eluel-boys, in the parish of Endeiiion; and from this mime have been obtained the finest groupes of this substance that are seen in collections, where it is in general very rare. The endellion exists likewise in Siberia, where too it ap+ pears to be very scarce, as I know of but a single specimen, which isin my possession, [ have seen in the shop of Mr. TMiaw several fraginents of this substance, sent with other minerals from Grazil, the biggest of which was a very large ‘single crystal, of the variety represented pl. vii,* fig. 8. Lastly I ain indebted to Dr. Wollaston for some small frag- ments of the same substance, in which the endellion is in the compact state, mixed irregularly and very visibly to the eye with the double yellow sulphuret of copper and iron ; and in which are observable little cavities, including very «small but well defined crystals of the same substance, inter- mixed -with minute specks of carbonate of lime and sylphate of barytes. These fragments came from Peru. The endel- Thon, which I mentioned above as coming from Brasil, is in like manner mixed very perceptibly to the eye with yellow sulpburet of copper and iron. The groupes of crystals of endellion from Cornwall are frequently accompanied with crystals of brown sulphuret of vine; and in sev éral sulphuret of antimony is likewise ob- served, commonly in fine needles, and frequently even ga- a pillary. In the compact state. The same pieces, that imclode crystals of this substance ‘jn Cornwall, inciade also parts more or less large, in which it is in the compact state. When this occurs, its fracture is _.® The plates. to this article are ynayeidably de feerad to our next number. thus SULPHURET OF LEAD, COPPER, AND ANTIMONY. 233 thus rendered irregular and granular, and its lustre is much interior to that of the fracture of the crystals. This compact variety in Cornwall is frequently mingled with sulphuret of zinc, which may easily jJead to mistakes ; and which Mr. Hatchett has very judiciously noticed in the analysis he made of this substance. The compact endellion of Brasil and Peru cleats is inti« mately mixed with yellow sulphuret of copper and iron. Description of the crystalline forms of endellion, and obser-. vations respecting them. j The primitive crystal of this substance, as I have already Primitive erys- eaid, isa rectangular tetraedral prism, pl. vii, fig. 1, the wh. height or side of which is to the sides of its terminal faces in the ratio of three to five*. Ihave not yet seen this crys- ta] in its perfect state, that is to say, without the planes of- any of the modifications belonging to it; and it cannot be obtamed by splitting, the attraction of cohesion, that unites the integrant molecules of this substance, being too strong to be overcome. By means of some of the accidental free- tures however, that occasionally exist, I have been able to discover the direction of its lamine, and perceive that this direction, as well as that of the secondary faces, agree per- fectly with the results of calculation. - Ido not think however, that this prism is at the same Intogrant paw time the form of the integrant molecule of this substance: ticle, but hitherto nothing has led me to form any- particular opinion with respect to the form of this melecule. » As the crystals of endellion are frequently loaded with Various alter fait, which the mineralogist may find embarrassing, I ona of thy have thought it necessary, for the ease of the reader, to eine a sabia 6 separately, in fig. 4, the various retrogradationst experienced by the laminz ofthe crystallization, which I have observed ..* The method I have-pursved for the determination of the primitive crystal will be scen hereatter. | t lgive the name of retrogradation [reculem-nt] to that act of crystal- lization, which has hitherto been known by the name of decrement, an expression that is totally false in many cases, as I have shown in the se- cond volume of my Treatise on Mineralogy, p. 206, in the part relating to the theory of erystallization. ihe 4 on 234 Fst modificas thn, SULPHURET OF LEAD, COPPER, AND ANTIMONY. en the longitudinal edges of the primitive prism ; in fig. 5, those I have observed along the edges of the terminal faces ; and in fig. 6, those that I have observed at the angles of these faces, These three figures are intended for the same purpose of convenience, as those which, in my former paper on this substance*, were given solely with this view, and the exact models of which had not yet been observed in nature. My experience in crystallography has frequently led me to remark, that, when the crystals of a substance are liable to any considerable number of modifications, and at the same time actually undergo seveial of them, this method is ex- tremely useful, aad trees the mineralogist, who is desirous ef ascertaining one of these crystals, from a task not unfree quently very troublesome. - There are even. substances, in which this method is very advantageous to the most expert crystallographer, and the present is one ef them. Uff modification. The pianes arising from this modificay tion substitute for the longitudinal edges of the primitive prism a plane equally inclined to those contiguous to. it, They are produced by the retrogradation of one row of the particles of the lamine along these edges. These new planes are frequently striated, asis shown in fig. 2. . Somes times they cause the complete disappearance of the faces of the primitive crystal, giving rise to another-prism, which is likewise a rectangular tetraedron with square bases, but se- condary to the primitive prism; and in the crystals of this variety that I have seen the faces were constantly striated, 2s in fig. S. This variety even led me into a mistake, when I wrote the first paper on this substance I presented to the — Royal Society, by inducing me to consider the planes of the prism of the varieties represented at figs. 10, 11, 15, 16, and 17, 38s belonging to them: but amore attentive examination, elucidated by observations since made ona great number. of other crystals, has taught me, that these striz were the simple effect of aggregation, and that these same planes be- ionged to their primitives. ‘ I shall ® Aiddilional nole,—-— and for which I was so unhandsomely re- proved by Mr. Smithton, in his enlige foe in the Philosophical Yransactions. + The striae, that eccur so frequently on the planes of crystals, are often , SULPHURET OF LEAD, COPPER, AND ANTIMONY. I shall not enter into any similar details concerning the other modifications, the number of each of these being af- fixed in each crystal to the planes belonging to it, and the table of these modifications, which will be annexed to this paper, poititing out in this respect at a single view particu- lars, which could scarcely be expressed by long cireumlocu- tion. In cousequence I shall oquiie “myself to fhe follow- ing observations. : ‘All the varieties, from fig. 2 to fig. 20 inclusively, are met with among the fragments of this substance, that are brought from Cornwall. I have'a very fine croupe of those represented at figs. 7 and 8, and a separate crystal of 8 and of 9. The variety fig. 8 is a regular aggregation, in the form of a cross, of two of the crystals fig, 7 elongated paral- lel to the planes of the Sth modification. It might also, and perhaps more justly, be considered as resulting from five ctystals, similar to fig. 7, united by one of their planes. I have likewise crystals of the varieties 11, 12, 14, 15, and 19. ‘With those at figs. 10, 13, 16, 17, and 18, | was fur- nished by two’ very fine groupes, anda superb single crystal, in the possession of Mr. R. Puillips. Fig. 16 answers to that numbered 17 in my former paper, which was not quite accurate. ‘Ia 15 and 16 of the same-paper the prism was much: too thick, and HEY, 2 are epee at present by 17 and 18." ; ea mE likewise’ the varieties from 21 to 26, ina very fine group, which, with the fraginents from Peru and Brasij al- often of very great use to siiteate the direction of the laanteeenot crystal- "lization, and not seldom are they the only means, that the crystals of substance afford. Thus the lenticular rhomboidal carbonate of oo pretty constantly indicates by its str’ the direction cf the laminez, and consejuently that of the planes of the primitive crystal. In the hexae- @ral prism of the same substance, the same stri# point out the direction to be given to the fractures, on which Mr. Haity has established the di- mensions of its primitive rhomboid. But we must beware of the illusion, that may sometimes arise from stria, which are indebted for their exist- ence only to an aggregation of crystals, such frequent instances of which are exhibited by the tourmalin, thallite, sulphuret of antimony, &c. : an illusion*by which I have shown I was at first misled myself with re- Spect to the endellion, after having observed, that among its varicties there .cxisted a rectangular tetracdral prism, the planes of which are frequently striate, ; aie ib ready Different vari- eties, Probably other ~warleties. SULPFHURET ®F LEAD, COPPER, AND ANTIMONY. ready mentioned, constitutes the only specimens 1 have yet seen from any place except Cornwall. ‘The groupe, which assuredly is not English, was given to me as coming from Siberia. Its gangue is an irregularly crystallized quartz, part of which is ofa dark blackish gray, in consequence of a mixture of very minute particles of sulphuret of lead, im- perceptible to the naked eye. The crystals of endellion are eovered by a slight stratum of green carbonate of copper ; and some sinall crystals of common dodecaedral pyramidal carbonate of lime (meétastatigue of Haiiy) are disseminated among them as well as in the quartz. Several small parcels of sulphuret of lead and blue copper are hkewise observable on it. Such is the resnit, which the most careful examination, and continual attenuon to every thing, that could render me better acquainted with this scarce and interesting substance, enables me at precent to lay Lefore the Royal Society. I am far however from imaginiog, that I have seen every thing pertaining to its crystallization. Undoubtedly other varie- ties, and other modifications, may exist ; and it is probable, that, among the small number of specimens of it in different collections, such may be found. From the numerous va- rieties, that exist mma single groupe of this substance, its primitive crystal appears to havea great tendency to be.mo- difed: but the modifications of this crystal, which I have given, are unquestionably sufficient, to render it easy to as- certain any new ones, if they should occur. These re- flexions are not introduced here without reason. Among the different speciiuens of this substance examined by me, T have seen several crystals belonging to some of the varie- ties [ have given, on which there existed likewise shght traces of planes belonging to other modifications, but which it was altogether impossible for me to determine. As an example of this I shall mention the erystal represented at Pl. Will, fig. 27, not only because it is one of the most strike ing for elegance of form, but because it is in my own pos- session. T a faces indieated by the letters x, y, and z, are cers tainly owing to, an intermediate retrogradation at the angles of tbe terminal faces: but the impossibility of measuring with precision the augle of inclination betweep these sian and ON DETONATING SILVER. 937 the primitive ones in this crystal, which is very small, and partly imbedded in its gapgue, completely prevents me from determining the pature of the three different retro- gradations, to which they owe their existence. : (To be continued in our next.) »:6 98 F On Detonating Silver. By Mr. Descotris*, Mr. Figuier, prof. of chemistry at the Pharmaceutical Fulrainating School at Montpellier, has lately written to the authors of Silver a this collection a paper on detonating silver, in which, after mentioning that Mr. Howard firft formed this compound, which was afterward obtained in larger quantity by Mr. Cruickshank, he points out a process for preparing it analo- gous to that adopted by the latter gentleman. A paper already published in this Journal + contains Former paper nearly similar results to those obtained by the professor of onthe subject. Montpellier, we shall therefore confine ourselves to the dif- ferences mentioned in his observations. Mr. Figuier has seen the detonating silver explode even ft explodes amid. Mind acid solution in which it is Senco when touched ™°¢ readily by a hard body. He has likewise ‘detonated this compound eaeamuas when dry by simple friction with the edge of acard. These facts indicate a much greater degree of inflammability than : had been supposed, and must lead us to be more cautious in preparing this substance. The professor has remarked, that detonating silver is not Not decom- decomposed by weak sulphuric acid, unless it has been pre- at by cued viously dissoived in water. oe ie Caustic potash appeared to him merely to change its co- bea as lour to a red, or a deep gray, without depriving it of its ful- sath : minating quality. This experiment, which I repeated, did not afford me precisely the same result. After remaining a considerable time in potash, the residuum gave only ashght . decrepitation, arising no doubt from the portions, on which the potash had not yet acted. * Annales de Chimie, vol LXIII, p. 104. '¢ Journal, vel. XVII, p. 140. 238 Fine lake by precipitat- ing cochineal with soiution @f tin. Blue wolfsbane contains green fecula, a gas, an earthy mat- ter, consisting of earbonate and phosphate of lime,\ ‘ON BLUE WOLFSBANE. XTV. Process for making a fine Lake*. A German chemist; whosé name is not mentioned, has published the following process for making a beautiful lake. : Take any quantity of cochineal, on which pour twice its weight of alcohol, and as much Gistilled water. Infuse for some days near a genile fire, and then filter. -'To the fil- tered liquor add a few drops of solution of tin, and a fine red precipitate will be formed; Continue to add a little soé lution of tin every two hours, till the whole of the colouring matter is precipitated. Lastly, edulcorate the preciprtaté by washing it ina large quantity of distilled water; and them _ dry it. XIEV. On the Blue Wolfsbane, by Purtip Antony Sreiwaceer*, Tue fresh leaves of blue wolfsbane, aconitum napellus, cultivated in a garden near Paris, being treated with a sufs ficient quantity of water at 45° [113° F.], geen fecula was - coagulated. The liquor separated from this fecula retained a peculiar. herbaceous smell, analogous to that of the leaves of scurvy grass after the greater part of their pungency 1s destroyed by exposure to the open air. The progress of evaporation entirely dissipated it. ‘Toward the end a matter of a gra- nular form was separated. After this was washed aud dried, a portion subjected to the action of the blowpipe on pla- tina was not melted by the intertor flame, but became whitish, without swelling or decrepitating. Another portion put into weak sulphuvic acid’ produced a pretty long effervescence. The evaporation of the fluid afforded acidulous crystals in the form of soft needles, which were decomposed by nitrate of lead. The precipi- tate, heated red hot by the blowpipe on a piece of charcoal, * Sonnini’s Biblothéque physico-économique, for 1508, vol, I,.p.c52- ® Journal de Physique, vol LXV, p. 294, - was ) SCIENTIFIC NEWS. 238 ‘was reduced into little metallic globules, rownd which a slight aureola shone, accompanied with a very perceptible phosphoric smell. The extractive liquor boiled down con- and muriate of tained a great deal of ammoniacal muriate. oe As other plants gathered by the side of the wolfsbane No phosphate yielded me no signs of phosphate when analysed, I con- sta pesicy ceive the organs of this plant have the faculty of assimi- it. lating phosphorus, or its elements, and converting them into an acid. _. From my analysis it follows, that the aconitum napellus Summary of contains iis contents. Green fecula, ‘ An odorant gaseous substance, which I suspect to be vi- ~ rulent, Mauriate of ammonia, Carbonate of lime, and Phosphate of lime. Thus the existence of this phosphate in the blue wolfs- The phosphate bane, which Mr. Tutten of Wolfenbuttel announced nine- ae ea teen years ago, is confirmed. SCIENTIFIC NEWS. Tue annual courses of popular lectures at the Surry In- Lectures at the stitution, Blackfriars Bridge, commenced on the 3ist ult., Surry astute and will be continued every succeeding Tuesday and Thurs- “ig day evening, at seven o’clock, during the season. We un- derstand, that the following gentlemen have been engaged for the respeetive departments, viz. Chemistry and Mineralogy, Mr. Accum. Music, Mr. S. WrEsLEY. Experimental Philosophy, Mr. Jackson: and Physivlogy. (with Experiments), Dr. Davis. To Correspondenis. I am not acquainted with any work on the subject after which EK. H. inquires. The papers of Mr. Barlow and Mr. Lyall will be inserted jn our next number. ERRATA. P. 167, 1. 4 from bot. for Pl. V, read Pl. VE. 163, |. 4 for complete read comp'ex. METEOROLOGIC AL J OURNAL, For OCTOBER, 1809, Keptby ROBERT BANCKS, Mathematical Tastrament Maker, - in the Srranp, Lonpon. ; ae a ty tlpans. BAROME-| WEATHER. SEPFas9 den |Doreepo lho —- =) = Wore , Day of] 3 | at [ee z | 9A. M, Day. Night. Dp > Ii= ae i af 97 154148 158/40] 29°50 | Rain Rain 95° 146146153138 |. 29-382 Ditto Ditto 29 143] 47 | 53/42) 29°96 Fair Fair 30 148 | 56] 50/45 | 29°93 Rain Ditto OCT. 1 151152|56|49| 30°14 | Fair Cloudy 29 156158 | 60/55} 30°28 | Rain Ran. 3 | 56) 53 [61 | 55] “30°32 | Cloudy™™* Pag 4 | 57'| 54 | 62) 47 1 30°21 Rain “Fair 5 54:1 53°): 60) 51 30°10 Ditto Ditto 6 | 56153 }60}50; 3009 Ditto Ditto 7 vo V5) 1 ot a3). BO'Us Dittu Ditto 8 15014715542] 30°10 BME Ditto 9 147145 151/40} 30°10 Ditto Cloudy 10. 145145 /49441} 30°04 Ditto Ditto | 11 47 | 45 | 50/41 30°02 Ditto Pair 12. $44140]48136} 30°10 Ditto Ditto 18 40 | 39 | 46 | 37 30°19 Ditto Ditto 14 1307144 | 49735 | 30°26 Ditto Ditto DS 37 | 44 148 | 40 30°32 Ditto + Cloudy 16 (47|53|55/41] 30°14 Cloudy Ditto 17 54 | 55 | 58 | 52 30°11 Ditto Fair 18 154156] 58|54] 30°09 Rain Cloudy 19 55 1° 57- | 59K 52 30°17 Ditto Rain 20 $53. 153 ).55 SP 30°18 Cloudy Cloudy 21 52 |.53.1)55 160)" SOLS Ditto Ditto 22 52 | 52 | 55 | 50 30°10 Diito Ditto 23 153 | 53 | 56148} 30°00 Ditto Fair 24 (51/541 58}49] 29°91 Rain Ditto 25 51 | 531.55 | 50 ZOU. Ditto Ditto 26 153 }560161}48} 30°28 Ditto Ditto * Day gloomy and close. 7 + Heavy fog. A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. DECEMBER, 1809. ; ARTICLE I. On Vegetable Astringents. By Joun Bostock, M. D: Communicated hy the Author. (Continued from page 222.) Aone the constituents of galls we always find muci- Mucilage lage enumerated, and Mr: Davy gives a process for obtain- | ing it in a separate state, but I confess, that I am not alto- gether satisfied with the force of the arguments, by which its existence is thought to be proved. Mrs Deyeux, who I believe first distinctly mentioned the existence of mucilage in galls, founded his opinion upon an erroneous supposi- tion, that no substance except mucus 18 capable of proé not the only ducing mould. The moulding, as has been shown above, tebgrinr yy evidently depends upon the other constituents of the infu- ~~ sion*. ‘With respect to the tests for mudcilages, the only Tests not ap- one which can be considered as applying generally to them, Plicable hate. * As a farther proof of this position I may remark, that I have ob- served the process of moulding in Mr. Hatchett’s artificial tan. Vor. XXIV. No. 109—Dec. 1809. R and %42 All mucilages insoluble in al- cohol, There appears . to be no muci- lage in galls. ON VEGETABLE ASTRINGLENTS. and which acts upon them when not in a concentrated state, is the acetate of lead; but this unfortunately cannot be ap- plied in the present instance, because it is equally aflected by tan and the yallic acid. The other tests which I found 10 wy former experiments on this subject * to act upon par- ticular varieties of mucilage, such as the nitrate of pre F- cury, the oxisuiphate of iron, the nitromuriate of gold, and silicated potash t, were each of them limited to those varie- ties, and can theretore be of no-use in determining the ge neral question, beside that some of them act upon the other constituents of galls, There is, however, one pro- perty, in which all mucilages seem to agree, i.e. their in- solubility in alcoho! ; and it is upon this property, that Mr. Davy has founded bis operation fer obtaining the mucus of galls in a separate state. - I endeavoured to imitate his process, but without stiecess. A strong infusion of galls had its tan separated by jelly, the residual fluid was evaporated, and its sclid contents were boiled in alcohol, in order to remove from them any extract or gallic acid. What was left was digested in warm water; a very small quantity of it seemed to be dissolved, and the fluid assumed a light green hue. The acetate of Jead threw down a slight precipitate, and left the fluid co- lourless ; it was tinged by the oxisulphate of iron ; tartarised antimony and oxalic acid had no efect upon it; it was nei- ther acid nor alkaline; being slowly evaporated, a small gray residuum was left, which did not resemble mucilage in any of its physical properties. We come io the same conclusion respecting the existence of mucus in galls by” digesting a quantity of the powder in successive quantities * Nicholson’s Journal, XVIII, 28, + Tam induced to consider the precipitate which is produced by the addition of silicated potash to gum arabic, a fact which was first noticed by Dr. Thomson(a), as depending, not upon the immediate action of silex upon gum, but upon the lime which enters pretty largely into its composition, and which causes oxalic acid to throw down a copious precipitate from it. When silicaied potash is added to the different ve. setable infusions, the same effects seem to enstie as from the employ~ ment of the alkali without the silex, (ay Chemistry, V, 40. ' of ; ON VEGETABLE ASTRINGENTS. 243 of aleobo! or ether; in both these cases, after the action of these fluids has been carried to its fullest extent, a residuum is left,’ upon which water has no action, yet mucilage iy in+ , solublé both in alcohol and in ether. J feel it necessary to apologize for differing from Mr. Davy on this point of fact, but T may say in diy excuse, that he relates the process for obtaining the mucus of galls rather us one calculated to answer the end in view, than as what he bad really put in practice. ‘That portion of the galls, which in his analysis he attributed to mucus, I should refer principally to the imperfect compound of tan-aud jelly, which I have described above. I shall now make a few observations on the chemical pr6- Catechui very variable in its perties of catechu; but it is necessary to premise, that the '°!!*° qualiues: varieties in this substance are even greater than those in the gall nut. That which I employed was considered by a friend, on whose judgment [ could rely, as a good specimen of the kind which is most esteemed by the apothecaries } yet from my experiments with it, it seemed to differ from that employed by Mr. Davy. Cold water being digested Treated with upon it for two days took up 75 of its weight; the solution ee was transparent, and of a fine reddish brown colour ;. the portion which remained undissolved seemed like a mixture of white and red particles, in which the white considerably predominated, but when it was dried its colour became as deep as that of the catechu in its recent state. The solu- tion slightly reddened Jitmus; it was rendered turbid by the oxalate of ammonia, and a sinall quantity of a dense pres cipitate subsided from it. It was also liable to the opera- tion of moulding, although not so readily as the infusion of galls. When catechu is treated. with hot water, it is and with hoy partly dissolved and partly suspended. An opake infusion ; is formed, which. contains about 75 of its weight of so~ lid matter. The warm infusion still continues quite opake after being passed through a paper filter, while the filter gains a great addition of weight, and is stiffened as if it had _ been soaked in some kind of mucilaginous matter. By standing for some days, a part of the contents is deposited, and the warm infusion beeomes transparent. If the clear solution be evaporated, the residue is not capable of being Re completely 244 ; @N VEGETABLE ASTRINGENTS- completely redissolved, and the second infusion is rather The transpa- lighter coloured than the former one. ‘The transparent so~ ie aac lutions of catechu, whether formed by warm or by cold partof their water, slowly deposit a part of their contents, im the form ce-qgammaniie of the whitish residuum inentioned above, while at the same time a kind of efHoreseenee creeps up along the sides of the glass to some distance above the surface of the fluid. This deposition proceeds the more rapidly, the stronger is the infusion; but there does not appear to be any absolute limit to its continuance. kn one instance I found, that a saturated solution of catechu, after standing two months, and grow had lost rather more than half of its solid contents, but a dine part of it had been expended in forming a stratum of mould. The substance that has been deposited is less soluble in wa- ter than the recent catechu, but it dissolves readily by an increase of temperature; it forms a solution of a lighter colour, and it has less: disposition to separate from the fluid. Requires suce Although eatechu is so readily soluble in water, yet, as is cessiveinfu- the case with galls, it requires a number of successive in- fo fusions to separate the soluble part from the smallinsoluble residue. Ten grains of catechu were infused in 50 times their weight of water for 24 hours; the fluid was then. drawn off, and the same quantity of water was poured upon the residue. After @ of these successive infusions, the ef- fect of the oximuriate of tin was no longer visible, that of jelly was barely so, but the oxisulphate of iron continued to tinge the fiuid until the 15th infusion, and at this peried the acetate of lead preduced a very slight cloud. The in- soluble residue left was not more than jy of the weight of the catechu employed; it seemed to be a heterogeneous mass, consisting probably of accideutal impurities, and it may be expected therefore to vary in quantitye Mr. Davy found no less than ;'; of the catechu upon which he operated to consist of insoluble matter *. Treated with Alcohol, at the temperature of the atmosphere, slowly i nical dissolves catechu. By boiling the effect is much promoted, and the alcohol takes up about ,'5 of its weight, which re- mains permanently dissolved, but the quantity varies very * Phil. Trans, 1803, p. 289. much ON VEGETABLE ASTRINGENTS. much in different specimens.. About } of the catechu seems insoluble in this menstruum, ‘This part was readily taken up by water, except a small dark-coloured residuum; the solution produced only a slight effect upon jelly and the oximuriate of tin, but by the oxisalphate of iron the whole became as it were coagulated, and was converted into -agray mass. The acetate of lead also threw down @ very copious precipitate from the fluid. These properties denote a considerable analogy between this part of the catechu, and the mucilaginous bodies, an analogy which is farther strengthened by a degree of viseidity, which may be ob- served in its solutions. The substance obtained by evapo- rating the spirituous solutions of catechu is of a deep red colour, soluble in water but less so than the whole ca- techu ; the solution is copiously precipitated by jelly, by the oximuriate of tin, and the oxisulphate of iron. It moulded by exposure to the atmosphere, I think, rather more readily than the entire catechu. The infusion of catechu is very copiously erecipiaited by jelly, but a part of the precipitate generally remains sus- pended in the fluid. The oximuriate of tin also acts pow- erfully upon catechu, but it is not much affected by tar- tarized antimony, it is rendered opake, and the brown colour is changed to red, but scarcely any precipitate is formed. The acetate of lead exercises the same instantaneous action on catechu as on galls; it immediately unites with all the eonstituents of the infusion, and leaves the fluid perfectly transparent and colourless. The nitromuriate of gold throws down a very copious precipitate of a blackish purple colour, and the nitromuriate of platina an equally copious ‘one of a deep reddish brown. The precipitate produced by the oxisul] phate of iron is of a deep olive green, and readily subsides from the fluid. This precipitate must, I appre- hend, be considered as an obvious indication of a small quantity of gallic acid; and my therefore be regarded as a proof of the variety, which exists in different species of this substance, since that which Mr. Davy employed was without this constituent*. J have always found the infu- * Philos. Trans, 1803, p. 269, sions Action of re- agents on the infusion. Unsuccessfal attemp's to se- parate the tan and extract of catechu. i a ON VEGETABLE ASTRINGENTS. «. siohs which I formed to be. slightly reddened by litmus. After the infusioas of catechu have undergone the operation of moulding, they are much less affected both by jelly and by the oximuriate of tin, but I never carried the process so far as to observe whether they could be entirely. deprived of the capacity of being acted on by. these reagents.., According to Mr. Davy’s observations the separation. of the tan and extract of catchu may be accomplished with a considerable degree of accuracy, and he points out three different ways in which this may be effected, Tan, he re- marks, is more: soluble in water than extract, 1f therefore catechu be subjected for a short time to a-small quantity of water, the tan alone will. be dissolved, and the residue will contain a greater proportion of extract. . L infused a portion of catechu for a few minutes in about ten times its, weight of water, by which a part only- was dissolved, The residue was afterward dissolved by the addition of more water, aud when each of the infusions was become clear, by depositing _a part of their contenis, they were both of them submitted to the action of jelly and the oximuriate of tin; the first ine fusiou was stronger, but I could not observe the least dif- ference in the proportioual effects of the two reagents. Mr, , Davy’s 2d method of separating tan from extract is found- ed upon, the principle, that extract is more soluble in warm than in cold water, and therefore if a saturated warm infu- sjon be formed, when it cools the tan will remain dissolved, while the greatest part of the extract will be deposited. J. put this process into execution, but upon applying the two reagents they both seemed to act in an, equal degree, dif- fering only in their effeéts in consequence of the matter which was deposited being rather less soluble than the en- tire catechu. The 3d method. of separating the tan from, the extra¢t is by forming a uumber of successive infusions, when it is said, that the tan will become. first exhausted, and the extract be left in a state of almost perfect purity. I have already related the result of this operation, which was_ not at all peer mable to the above statement. These cir- eumstances I regard as amounting to a positive proof. of an essential difference between the substances, which were em- pioyed by Mr. Davy and myself, In GN ‘VEGETABLE ASTRINGENTS. 947 In my former ‘paper I mentioned, that T had performed Rhatany treats some experiments on the extract of rbatany; which led me ed seh A aige o° to:conclude, thatiit consisted principally of tan. It readily one Ki dissolves in water, and: the solution is wuch promoted by an increase of temperature; as the water cools, a part of the rhatany separates, leaving about 3; of the weight of the fluid in permanent solution. ‘he fluid very slightly reddens lit- mus, and after some time shows:a tendency to mould. The _ part that 1s deposited from the solution by cooling does not appear to be different. from what is retained by the water, except that it contains a small insoluble residuum, which 1 am disposed to regard as an,accideutal impurity, and from which it requires a number of successive infusions entirely te separate the soluble part. That part which subsides from the warm infusion is also less soluble than the entire extract; but this I attribute rather to the effect of the ope- ration, than to any original difference in its nature. Alco- and with alco- hol takes up about =! of its weight of the extract, the so- hel. lution is promoted by heat, it requires several successive applications to remove all the soluble matter, and a portion is left, upon which the alcohol has no longer any effect. This.part is readily dissolved by water, and forms a solu- part insoluble tion, which is of a bright red colour, which was rendered in alcohol. slightly turbid by jelly and the oximuriate of tin, but was very copiously precipitated by nitromuriate of gold and the acetate of lead, the former producing a reddish brown, and the latter a delicate pink precipitate. The results are very similar to what has been related above respecting the action of alcohol upon: catechu, and indicates the presence of a substance, which in its chemical characters bears an ana- logs to mucus: at the same time it must be remarked, that the solutions of rhatany are free from any degree of visci- dity. .Rhatany acts very powerfully upon jelly, forming with it Action of re- a light red precipitate, which generally separates from the sont on 4 fluid. It appears, that: the most perfect compound is pro= duced by’about equal parts of prepared isinglass and ex- tract, but the substances do not unite in the same definitive proportion, the nature of the compound being much in- fluenced Is tan always identical? ON VEGETABLE ASTRINGENTS, fluenced by the relative quantities in which its ingredients are presented to each other, When there js an excess either of jelly or of tan, the precipitate subsides more slowly, and is of a softer texture, Beside jelly, rhatany is precipitated by oximuriate of tin, oxisulphate of iron, acetate of lead, tartarized antimony, nitromuriate of gold and of platina, alum, lime, and sulphune acid. The oximuriate of tin throws down a dense precipitate, but only in moderate quantity. much less than that produced by jelly; the oxi- sulphate of iron produces a black precipitate, which speedi- ly subsides to the bottom of the vessel; acetate of lead in- stautly combines with ali the contents of the solution, throws them down in the form of a pink mass, and leaves the fluid transparent and colourless ; antimony throws down a small quantity of a reddish powder; the nitromuriate of gold produces a very copious dark purple precipitate, and the pitromurrate of platina an equally copious one of a reddish brown colour. Alum readers the solution turbid, changes its colour to a dirty brown, and throws down a small quans tity of precipitate; lime water heigktens the colour, and produces a red precipitate; and sulphuric acid produces a copious precipitate of a light red colour, Carbonate of potash converts the colour of the solution to a deep blood red, but produces no farther effect. After the infusion of rhatany has bad jelly added until no further precipitation is produced, the oximuriate of tin renders it slightly turbid, but can scarcely be said to form a precipitate ; 1f however, the experiment be reversed, 1. e. if jelly be added to the in- fusion after the actien of the oximuriate of tin, a copious precipitate is thrown down. - It has been a much agitated point, whether tan be in all cases uniform in its properties, or whether there may not be substances poffeffed of the leading characteristics of tan, particularly its property of precipitating jelly, which yet, in some respects, may differ from each other. This latter opinion has heen adopted by Proust; while Mr. Davy, en the contrary, appears in¢lined to attribute any diversity of opes yation on the different reagents, not to any difference in the tan itself, but to the peculiar substances with which 1t may be ON VEGETABLE ASTRINGENTS. be united. I confess that I am disposed to adopt the doc- trine of Proust: for although Mr. Davy’s remark be correct, that in all végetables, in which tan has been discovered, it exists in a state of combination with other principles, and that its action must necessarily be modified by these com- binations; yet I conceive, that, us far as we are able to Probably not. judge, the nature of the combinations wi!! not account for the difference of the effects. The extract of rhatany is co- piously precipitated by jelly, aud considerably so by the oximuriate of tix; but as this reagent produces scarcely any effect after the addition of jelly, we must conclude, ac- cording to the generally received opinion, that the effect of both these substances depends upon the tan which it con- tains, so that we are led to regard it as consisting of tan, combined with a little mucilage and a minute portion of gallic acid. Yet we find, that tartarized antimony and ‘the carbonate of potash, which act so powerfully upon the tan of the gall-nut, scarcely produce any precipitate with the tan of rhatany. We must therefore conclude, either that the action of the oxide of antimony and the caibonate of potash depends upon the presence of some extraneous body,’ or that there may be a substance, which forms an insoluble compound with jelly, and which, on this account, is entitled to the appellation of tan; but which may be so modified, as in some states to unite with the above reagents, and at other times to have no effect upon them. Considering the mag- nitude of the effect produced, compared to the supposed nature of these extraneous bodies, I cannot but think the latter opinion the more probable. This, it is admitted, is no more than a presumptive argument; but I apprehend, that the same point is more firmly established by what I have observed respecting Mr. Hatchett’s artificial tan. This Artificial tans substance we may regard as homogeneous, and therefore not liable to those objections, which apply to such experiments as are performed upon any of the vegetable infusions; and, yet I have found it to act very differently upon other re- agents, at the same time that it exercised the most power- ful action upon jelly. I have now before me a solution of the artificial tan, which copiously precipitates jelly, the oxi- 4s muriate 1 50 ON VEGETABLE ASTRINGENTS, muriate of tin, the oxisulphate of iron, the acetate of lead, alum, lime water, aud sulphuric acid; and yet it is. very shehtly atiected by tartarized antimony, and not in the Jeast, by the carbonate of potash. Ave we then to conclude, that pare tan, such as may be supposed to exist in Mr. Hat-. chett’s preparation, has no affinity for the oxide of antimony and the carbonate of potash; and that, when the ta. of the gall-uut is precipitated by these reageuts, ii depends. upon a primary action, which they exert upon some other cou- stituent ? or that ihere may Le substances, which have some, specifie differences, although, from their leading properties, they may be all. of them strictly euuti d to the, generic name of can? The comcidence beiween Mr. Hatchett’s tan aud rhatany, so far as the reage :s are concerned, might, seem to favour the former opinion; yet the latter suppo- sition implies nothing that is improbable, and, is agreeable to the, analogy, which prevails in other vegetable pro- ductions, With respect to any general conclusions, that | may draw from.my experiments on these different vegetable sastrin- gents, I feel so well aware of the difficulty of obtaining un- exceptionazble results, and the uncertainty of the inferences that ought to be deduced from them, that I shall not, ven-, ture to consider the positions which I have adyanced:as as- certuined matters of fact, but rather as subjects for future investigation. All that I can expectfrom this paper is, that it will serve as an addition to the store of information which is daity accumulating, and which may assist at some future period in laying the foundation of a more matured theory, than avy which could be constructed at present, faverpool, October 10, 1809, TI. SULPHURET OF LEAD, COPPER, AND ANTIMONY. ]51 IT, Memoir on the triple Sulphuret of Lead, Copper, and Anti= mony, or Endellion. By M. te Comte vie Bovurnon, F.R. and L. S. (Continued from page 237.) Determination of the primitive crystal of endellion. From the direction of the lamine of crystallization’ of Primitive crys» the endellion, with which some accidental fractures had ‘2! ascertained, made me perfectly acquainted, as well as from the general aspect of the crystals of this substance, I could not doubt, that the form of its primitive crystal was a rectangular te- traedral prism; and the similitude of the retrogradation of the crystalline laminz along the edges of the terminal faces, indicated by the equality of the inclinations of the faces belonging to them, made me presume, that these faces must be squares. Accordingly it appeared to me, that the pri- mitive crystal could only be a cube, or a rectangular te- traedral prism with square bases, the altitude of - which would be greater or less than the side of the terminal faces. “Now remarking, that, with very few exceptions, in all Where a pri- substances, that have a perfectly symmetrical solid for their Saree ose primitive crystal, as the cube, rhomboid, ‘octaedron, regu- the secondary lar tetraedron, &c,, the secondary forms, produced by the esas = various retrogradations to which they may be subjected, re- ; tain the same symmetry; 1 observe, that, in the crystals be- longing to the secondary faces of the endellion, there is no symmetry between the planes that supply the place of the edges of the terminal faces, and those of the longitudinal edges of the prism, either with respect to the number of these planes, or to their inclination ; whence I am naturally led to infer, that the rectangular tetraedral prism, the pri- mitive crystal of endellion, is nota cube. Of this I was fully convinced, when I presented my first paper on this substance to the Royal Society; and it was this, that then prevented me from giving the dimensions of its rectangular a tetraedral O52 SULPHURET OF LEAD, COPPER, AND ANTIMONY. tetraedral prism, as I could not sufficiently depend on the angles of ieidence, which the secondary faces, I had then seen, enabled me to take; accordingly I contented myself with giving a very near approximation to the measure of these angles, without subjecting them to the scrutiny of cal- culation *. agit ag Circumstances having since enabled me to aequire per- crystal was aw fect certainty with respect to the measures of these angles, eeitained, it now remains for me to determine the dimensions of the tetraedral prism. To effect this, after recognizing four dif- ferent retrogradations along the edges of the terminal faces of the prism, as well as four others at the angles of the same faces, I observe, that the dimensions of the crystal may be determined either by the first of these retrograda- tions, or by the second: I observe too, that each will serve reciprocally as a support or confirmation of the other. Directing my attention in the first place to the four re- trogradations, that take place along the -edges of the ter- minal faces, I begin by taking as aceurately as possible the angle formed by the planes arising from each of these re- trogradations with the terminal faces of the prism, and find one angle about 130°, another about 135°, a third about 149°, and the fourth between 171° and 172°. I thew draw a horizontal line, ABC, fig. 28, representing one of the edges of the terminal face of a crystal perfectly resem- bling the primitive one, but composed of a certain number of crystalline molecules united, and the equal divisions of * Additional note. It was not from omission therefore, but for valid yeasons, that I did not give the cube as the primitive crystal of this sub- stance. Mr. Smithson, to whom I am very well known, might have done me the justice to suppose, that, if the determination of this crys- tal, from the facts I could then observe, had been as simple as his: cal- culation indicates, my eyes had too much experience in crystallography, for it to have escaped me. If however he had entertained any doubts on this point, he was sufficiently acquainted with me, to have communicated them to me ina less hostile manner; when I would with great pleasure Have submitted to hitn the reasons, that had determined me to act as [ did. By this science-would have lost nothing, and I should have gained much, in probably not experiencing the extraordinary, and I will boldly say womerited conduct, that has been held toward me in the name of the Royal Society, of which 1 am proud to call myself a member, and for which J shall always feel the highest respect. which - SULPHURET Of LEAD, COPPER, AND ANTIMONY. 253 - which at the points A, T, B, C represent the extremities of Mode in which the several edges of the component crystals.. From the ex- the primitive ¢ ; \ ‘ crystal was aS tremity C of this I let fall the perpendicular Ch, repre certained. senting the direction of the side, or altitude, of the prism, and the length of whieh I leave undetermined. Through the extremity of this line, C, I draw the lines GCP, FCO, ECN, DCM, forming with it angles of 130°, 135°, 149°, and 171° 30’, which I produce indefinitely above the point C. From the poimt B, the extremity of the side of the first molecule, [ erect the indeterminate perpendicu~ lar BG, cutting all the preceding lines. It is evident, that the lines C G, CF, C E, and C D, will indicate the direction of the planes derived from the four different retrogradations, that take place along the edges of the terminal faces; and that, if one of them be made by a single row, the part of the perpendieular B G, included between the line of the direc-= tion of the plane derived from this retregradation and the line AC, will represent the height of the molecule of the last lamina placed on it, and consequently that of the pri- mitive crystal. . It remains now to inquire, ubieh of these retrogradations was most probably made by a single row; aid? whether, after having determined this, all the others will agree with it. The angle F C B, or that of inclination between F C and AC, being 45°, or the supplement of B CO, which was by construction 135°, would indicate a height equal te the edges of the terminal faces, and consequently the cube as the primitive crystal; and the observation already made mnilitates against the choice of this, unless the farther ob- servations, in which we are engaged, oblige us to adopt it. The angle of inclination, GC B, of the Ime GG, would indicate a height greater than that of the cube; and in all the crystals of this substance the longitudinal edges of the prism being constantly shorter than those of the terminal faces, I am led rather to reject than adopt this height, which would give 28°6, the edges of the terminal faces be- ing supposed 24. The choice then remains between the two! retrogradations represented by the two lines EC and DC, the first indicating E B for the height, and the second DB; and the reedluticn of the two rectangular triangles EBC 254 Mozte in which the primitive evistal was as- eertained, SUBPHURET OF LEAD, COPPER, AND ANTIMONY: EBC and DBC will very teadily give the value of thesé two lines with respect to the edge of the terminal faces re- presented by BC, and which we have already supposed to be 24. Bai as the height D B, which then would be about 3°58, would not agree with the inclimation of the planes belonging to the other statements, the choice cannot remain doubtful, it falling necessarily on E B, which is of 14*4, and consequently to the edge of the terminal faces in the ras tio of 14:4 to 24, or of 3 to 5. And in fact, on fixing at this the height of the primitive rectangular tetraedtal prism, the determination of the other statements by caleulation agrees perfectly with the inclination found by measuring the planes ansing from them. © Besides, the height DB of 3°58 would be much too smail with respect to what all the crystals of this substance exhibit; while on the contrary that of 14:4 agrees with every thing found by observation in these crystals. It reniains now to examine, whether the»retrogradations at the angles of the terminal faces agnee with this height; and, if they should not agree with it, whether'they do not polut to one more natural, and) more fit to be adopted. To proceed on this examination, 1. take with the instru- ment, as accurately as possible, the augle of incideace .be- tween the. terminal faces and the four planes which take the . places. of their angles... Their measurement gives ine 125° for one, between 134° and 135° for another, between 150° and 151° for the third, and about 172° for the fourth. ‘The terminal faces bemg a perfect square, fig. 30, and the side of the square being assumed 24, the diagonal R'S is 33°94, aud cousequently its half 1s.i16°97. As every retrogradation at) the angles of a polygon is made on the diagenal passing through these augles, if we suppose the primitive rectangular tetraedral prism, of which fig. 30 represents the terminal face, cut by a plane passing through the diagonal K.S and that which is opposite te it in the lower face, all the diagonals of the molecules of the ’ superticial lamina, on which the retrogradation is made, as. well as of those superimposed on it, will be placed om the diagonal RS, or parallel to it. Let QS, therefore, fig. 29, representing this diagonal, be drawn horizontally, and. divided a .. e “s SULPHURET OF LEAD, COPPER, AND ANTIMONY: divided at the points V W into equal parts, which shall be to those of, the side. A C,, fig. 28, of the terminal faces, in the ratio of 33°94 to 24: these divisions wissen ‘the diagonals of tle crystailine molecules placed on the whole diagonal QS. From the point S, the extremity of the line QS, draw the lines gS7, eS.a, q Sd, and mS /f, so as to make with this line angles of 125°, 134° 30’, 150°30', and 172°, and produced indetinitely above the point S.. The lines S g,.S e, S gq, and Sm, will represent the direction of the planes produced by the four different retrogradations, that take place at the angles of the terminal faces of the primitive prism. As every retrogradation, that takes place at the angles of crystals by diagonals, is equivalent in the effect it produces to a retrogradation that takes place sim- ply by semidiagonals; to find the height, which,that of the four that takes place only by a single row would give, in order to see whether it would accord better with nature than that of -3 to 5 given by the observations that have been made on the retrogradation along the edges of the terminal faces; from the point R, half of the eae W S, erect the perpendicular Rg, cutting the four lines Sg, Se, Sq, and Sm, representing the directions of the substituted planes. Inquiring now whether any of these planes may be produeed by the simple retrogradation of a single row, f perceive immediately, that for the same reason as was given respecting the retrogradation along the edges of the termi- nal faces, those planes must be excluded, the direction of which is,represented by the lines eS and gS. ‘There re- -main then those denoted by the lines g'5 ad mS. Tor the same reason likewise us was given betore, that which an- swers to the direction mS cannot be adopted ; consequently our choice is confined to that in the direction gS. The re- solution of the rectangular triangle g RS would give 96 for the height of the molecule, the side of the terminal faces being still supposed 24: so that this height would be to the side in the ratio of 9°6 to 24, or of 2to 5. Observ- ing then, that the result of the calculation made with the ratio of 3 to 5 agrees better with what the inclination of the secondary faces of the endellion exhibits in nature, than that made with the latter ratio: remarking too, that the same 253 Mode in whick the primitive crystal was as- certained, 1D Or =p) The determi- nation of a pri- mitive crystal, with sufficient data, a simple process. SULPHURET OF LEAD, COPPER, AND ANTIMONY. same ratio of 3 to 5 accords better with the customary di- mensions of the crystals of this substance, almost all these erystals exhibiting this proportion between their height and breadth, while I have not yet found one in the proportion of 2 to &: in determing the ratio of the height, or side of the primitive prism to the side of its terminal faces, I fix on the proportion of 3 to 5, to which I was betore guided by the observation of the retrogradations that take place along the edges of the terminal faces. In consequence I conclude, that the primitive crystal of endellion is a rectan- gular tetraedral prism, the height of which is to the edges of the terminal faces in the ratio of 3 to 5. I have not hesitated to give with considerable minuteness the method I pursued in determining the primitive crystal of this substance; 1n the first place because it renders the Royal Society better acquainted with the grounds on whiclr it is established, and shows, that this determination is by no meaus the result of an opinion adopted at first sight, or of a slight observation of a single crystal merely: and se condly, because these details show how simple and easy such determinations are, when nature supplies us with suf= ficient data, and at the same time how far the calculations they require are from heing comp\icated*. The same may be said of the calculations for determining the planes produced in crystals by retrogradations of the crystalline lamin: they never require any thing more than the resolution of a trian- ele, for which there are always sufficient data. I think I may affirm, that, by means of the method given in my Treatise on Mineralogy; and the use of the protractor with a mova- ble radius, which IT have likewise made known, and which greatly abridges the trials we are sometimes obliged to make, for determining from the angles of incidence of the secondary planes of the crystals the nature of the retro- gradatious calculated to give rise to them; there exists no ~* Additional note. This method having never yet been given in any work on miveralegy in so simple and easy a manner, and besides the Philosophical Transactions hitherto containing little on the subject of crystallography were farther inducements for me to enter into) these particulars. To me it appears, that they cannot but render this paper more interesting. seience, SULPHURET OF LEAD, COPPER, AND ANTIMONY. 94 science, the application of which is more easy, than crystal- lography. From the angle of incidence of 135° between the termi- Circumstanees nal faces and one of the planes that are substituted for the Hes pice edves of those faces in the rectangular.tetraedral prism of the endellion; from that searly of the same number of de- grees, which one of the planes substituted for their angles makes with the same faces; and lastly, from another of 135°, which one of the planes substituted for the longitu- dinal edges makes with the sides of the prism; we may be very easily led, if we confine our observations to these facts, to consider the primitive crystal as a cube. These angles of incidence however, either exact, or so near it that the in- strument cannot detect the difference, may be produced by -retrogradations of a number of rectangular tetraedral prisms by no means of a cubical figure. I have assigned the rea- sons, which have appeared to me to militate against our ac- ceding to this first attempt. I am persuaded we much too readily yield to an inclination to consider as crbical the primitive crystals of substances, the secondary forms of which indicate a rectangular tetraedral prism. There are already a sufficient number of substances, that really have the eube for their primitive crystal, though their integrant molecules are of a different form, without our enlarging it unnecessarily. Dy domg thus we afford an additional han- dle to those persons, who, seeing in every primitive crystal nothing but the form of the integrant molecules, from which however it is frequently very remote, make of the numerous repetitions of this form in several mineral sub- stances, that are totally different, the grounds of a very un- - founded objection to crystallography. There is a fact relating to this substance worthy of re- mark, whjch is the equality of the number of retrograda- tions miade both along the edges and at the angles of the terminal faces, and the great analogy between the planes owing to them. VoL. XXIV—DeEc. 1809. S TABLE ABS SOG, SERA 2 sa aN a te SORE DON TOT Ce ne a y WO.1T SUL “wisiid ay} Jo RS 19 UI10} 9Y} WOT SUL saSpa eurpnySuoy ay} Su0jeyqSiaqar | ©¢ GLL| £9 ,0SL | 6 VOL | WS,tst | 9.871 HHP be ieee ee ee eee ; -8400 JUS & £97e}s SUMiny ¢pab "ayEeeed St ea L Aq jo e[sue | | jo ajsue { | Jo saj8ur p| JO soisur F imate ayy uy Pe Pe Sire 2 Se BS Se ee ee eee *tusiid ayy Jo 2 _ tuusiid yeipa : sure, § pue ‘yp pvatq Ul SMO’ g kg ayajdui09 ay} UT “po ne nnn — es | jo a[8ue 1 | Jo afSuv 1 | Jo sazSue p] Jo sopsue F ‘ 2 | | “oatptuy | | | | EL ue ‘uistid jeapaeay | 49ST. saSpo [euIpnysuoy ay}. suoje mos 1 Ag -9} Je]NSuryal VY - \ ‘wisiid ayy Jo | 06 06 -1id ag} Jo UOISAaAUT a ————— *uorye9 “non. -yrpour pz} -yIpour qsj| *sourjd rite ; : ‘asny *asn} ayy jo usid jaya jo utstid, oAtuatid pyr jo saurjd|ayp josauerd| our usta | “4° yA i ae aaa oud WA | 24? TITAN a ee ee *sueTvoYyIPOW sew ‘ajo,duo9 st u0led i-std JayJO OY JO Ssolf1 YUM Se [OM] -YIpOUt ay} TOt{M 19qI0 ‘suoneo *SUOTILPLASONOI BYI JO SANJEN se Sarsud aargruid aq Jo ssou) YM] yoRa YUM UOJ sauryd *yeyshsd BY JO WOW “GIpour wioy sourjd Mau oy yey sesuy [mou eyraey solsuy emi = JOV ON: *speysaso ou} Jo sauLyd ay} Jo SuLjsout oq) Aq patuioy sojsuy Se ee ‘usd ay} 3) seSp —” 'pnyzsuoy ay} ye apew SUOILPRAHOAJOY “suorjroyfipopyy 21jDUset a “G 0} § JO Oljed ayy UL aseq eYI Jo apts auy Lae eer 03 st wistad ay} Jo aSpa Jo apis oy3 Yoram ur ‘saseq gaenbs yj tusiid perpavaja} dejnsuezoe1 ¥ i Saat "NOITTSANG Jo 1VLSANOD DAILIAIUd 2 Jo SNOILVOIMIGON 94 ATE L *SQOR] [RULIIAY 9Y} JO sospa at} Suoye yypeaiq ut smos p Ag "SOR] [RUIMIa} 54 Jo saspa ay} suoje yi preiq wi Mort T Aq -19} ay} Jo saspa oy} Suoje ySray a1 sume! ¢ pus ‘yypraiq ut smo gE Lg -13} dU} Jo saspa ay} Juoje 4ydieg ut Bowe] G puw ‘yypeaig ut mor [ AG ~ (6) *SUOIZEPeAZOMar OY} JO a1njzeNT eR cna 1 fee ena GO DM - e 5s 8. HE AGT | OE V1 | 0G Sel | oe 86 | 83 141] S028 S5' | ps BY eo Ss oo a ft | \ 8'3.2e g ‘ = 2 rt O a 6 & 8S SOT} OF OOT| SF 061] 3 6r1| BABES | “yg Shams de aa | de easier eal ee ea "SooR} TRULO BS a 8P PAL esl SST s2°8 | “ug ° << fay] _ a =e 5 foc fh as = meee Tae *souRy peUnT =" = 9°) EL OFT | 8h GOT OF ™g | “UP =a ea “MOIeoyip | *UOTPeIYIp } *UOT}eOYIp OW Y19 eyi]-oW WIG ayyj-oW Yip ey} -saueyd "Ssaoey jo souvjd | so sauvyd | so souryd |feurpny8uo0j] Jeurwsay Hak des ay} yu ie) yi yt ar _ | -Urpout HME f OW MEAN | OMA HHEAAS| OND THEA | OTH HEM oie co5 on Yo ttiog| “sqa *saovy [PUI jo "ON -19] 9} Jo saSpo ayi Suoye osje opeurl yeisAso aariurd ayy jo SUOTICOYIPOUL J9Y}0 BY} Jo 930yI TIMJasoyy YIM Woz saueyd Wioj souRd Mou aqi 3eY) SeTsuUWY {Mou ay} ey) sojsuy *SaOKF [RUIUII9} BY} JO Sapa oy} 3e apeU suoZEpeAsorey *suorpoyipoyyy popwuvihg . —— reeg ceases Seamothgemen r SEY ARS ST SS ASS eet ' Canes : =o *saaty [RULUII9} BUY JO i BPSas 4 {, : J | $8 SSE | oF ori | 61 S61} £66 | £9 141| S28 Ss g311. sajSue oy} 7e yypeaiq ur smos g Ag ° ee ee a oe a aa oo. foe jes | Os erage Ue *sg0R} ]BUL = = D iz -19} ayy Jo sojSue ayy 7e GYsiay Ut OS COL] OF FSI] 08 611 | 0€ ost} BLS =s | “Mor wut % pue ‘yypeaiq ULsmos g Ag Sa. Be -- ——_——|— — oPeaS ~~ — *sa0vy |RUTU 5 2 = 3 -19} ay} Jo sajsue oy} ye Ayciay Ut AY OLT | AE SEl | GE PET Ste fp “16 u aes 4 “§ & a ee Bure g pue ‘qypeaiq ursmos ¢ Ag S903 & aS 1 rena ES Et io me ee ar "sooRy [BCL a6 2 -19} dy} Jo sajSue oy} ye GYSiay ul ¥ PV | OL Sol oa “u18 Burwey, G pue “yy peaiq ULSMON € hg So fT ‘uoyeoy | *MONvoyIp | *UONvoyIp ; IPOW YIOT|-OW YIG SYy3}-Oat Tg sya} ‘Seovyz *so0Ry yyijosouezd| jo souejd | so souvjd |jeulpnzrsuoy; yeurwey ‘uoleo } : “yipow ~ *SUOTILPRAZONOI DY} JO OINILNY OU THM, | U9 MAK | OHO SAAN SND REAR eet *yeqs19 BY} JO WOT ae *soory jeu ‘yeysAso amu JO ‘OND j-103 ata Jo sopsue oy2 ye Osye opeM ud 943 Jo ssoyi yoow SUOMROGIPOW J9t}O Ogi JO asoyy YIM] AOU asa WIOJ soured = mioy sound AOU aya eG) sapsuy j;MOU 94d IVY} so[Suy *SAOR] [RUINIIA} BY} JO So[cuy oy} ye peu suoryepesso1jay Meholsons Philos Journal VoX¥V P2 PH fp 260. he, os ottow of oe h He So, de Pouriow Sug Rae ; Miaoholsons Philos Sonurnal VAKXY PLT (p20. Crystallzehen of Cndelhon. ty Ye Count te Thournen < Fig 4. Fy Fg. 2 Nicholsons Philos Journal Vol XXVPU.VILp. 200. Orato Maz ateon of Cndlelleon y dee: Cond = peace a ~. —* aera Vclotont Philos Sonat Wel LE PLUM 200. 3 Onyste Ujatin , 4 the Count LA Loournen’. Ay (9 a - hy ON THE IRRITABILITY OF VEGETABLES; Itt Of the Irritability of Vegetables. By Mr.Rosert Lyarty; Surgeon. Mead at the Literary and Philosophical Society at Manchester, Oct. the 6th, 1809. Communicated by the ~ Author. Tue irritability of some plants has attracted much atten- tion from physiologists. Some of the most eminent men have without hesitation allowed, that vegetables possess the Saculty of irritability; while others most strenuously have endeavoured to disprove, that any such principle exists in the vegetable kingdom. As soon as the mimosa sensitiva was discovered, without doubt the motion of its leaves when irritated by a stimulus were observed, but at what time the cause of this motion got the title of irritability is perhaps not so certain. Haller was probably among the earliest, who ascribed the motions of some plants to an irritable princi- ple. After speaking of the comparative irritability of the heart, muscles, and intestines, with that of the ligaments, tendons, &c., he proceeds thus. * That this irritability exists abundantly throughout the _ & animal fibres, appears evidently from the example, which _ & we have in the polypi and other insects, which have nei- ‘* ther brain nor nerves, but are notwithstanding extremely ** impatient of all stimulus; and lastly we may take into ** consideration the analogy of some plants, the flowers and «© leaves of which either expand or contract by various de- ** prees of heat and cold, and some even with a degree of *< celerity not inferior to that of animals. This force is a _ €© different and new principle from all other properties of ** bodies hitherto known. We cannot account for it either * by gravity, attraction, or elasticity but by something s‘ which exists in the soft fibres, and which vanishes by dry- ** ing*.” Haller afterward in his Elements of Physiology remarks, “ It is evident, that there abounds, not only in the * animal but equally in the vegetable kingdom, a contrac- n * Prime Linee Phys, p. 152. Ed, 1758. © tile Irritability of vegetables. questioned, Haller’s ace count of if, Many consider it as admitted, . Sennebier un- willing to allow it. is of rs) ON THE IRRITABILITY OF VEGETABLES. ** tile power, by which the elementary fibres are drawn to- ‘© ward each other*.” "Many authors, as Gmelin, Smith, Darwin, &c.,have a long time since used the word irritability, when speaking of the .motions of the parts of vegetables; and in the present time it is nearly as common to talk of the irritability of the ve- -getable as of that of the animal kingdom. - When I began this paper, it was my intention, to have taken a compendi- ous view of all that had been said on vegetable irritability ; but the subject having now become so extensive, I found time would not permit me to make those experiments, which would have been requisite either to have proved that the ve- getable kingdom in general was endowed. with irritability, or to have disproved it. I have therefore contented myself at present with detailing some experiments made on parti- cular plants: and even from these I hope to prove, that, if we do not admit that vegetables possess irritability, at least that they are possessed of something which is adequate to the muscular power in the animal body; and I am convinced, that without admitting this, many beautiful phenomena must perhaps for ever bale the attempts of physiologists to explain them. One of the most celebrated ae ae physiologists, Sen=_ nebier has already treated extensively on this subject. He related almost every thing then known concerning the mo- tions ef vegetables, but has always been unwilling to allow, that an irritable principle had any share in these motions, and has tried to explain every phenomenon (which was be- fore thought a proof of irritability)on mechanical principles. Tn the following pages I intend to quote some of his nto and endeavour to overturn them. As confusion might arise from the word irritability not being well defined, it becomes first necessary, to have Sen= nebier’s opinion on this point, and then to fix what we un- definition - derstand by it at present. ‘* Sennebier says: ‘* Irritability - “‘ is that property, which forces a body to centract itself ‘© when it is acted upon in a manner proper to produce this *¢ effect; animals manifest this contraction in their mus- ‘© cles in consequence of burning, pricking, or the contact * Elem, Phys, vol, 4, p. 440. 6 of CGN THE IRRITABILITY OF VEGETABLES. ihe) ‘Dy: oo -** of some acrid fluid, either’ corrosive or spirituous; then ** the irritated body regains its former state, and the convul- «« sions are often repeated, although the impression, which _** is the cause of them, is not renewed. Wecan sometimes ‘* recall these motions when they are finished, by the same ** means which at first produced them. This irritability ‘* shows itself by the action of a stimulant, which may be “© of a very different nature, but always appropriated to the ** muscle which it ought to move*.”” In another place he says: ‘* We have pushed the analogy between animals and ** plants too far. If we understand by irritability the power “< of being affected by foreign bodies, it will be found in ** almost all organized bodies; if we understand the volun- ** tary command of a muscular force, the analogy subsists _“ no longert.” Iam willing to adhere to the definition, which Senne- Volition not bier first states, but cannot agree with him in admitting the paecnink 3f Eo) latter; for I do not consider that volition in every instance irritability, _ is connected with irritability. We know weli, that the sen- _ sible iris often contracts and dilates without our knowledge of it. Here then volition, or a voluntary command of a muscular power, is out of the question ; yet none will deny, but that the iris is one of the most irritable parts of the ani- mal body. We also sometimes observe, that the motions of the iris continue, when all voluntary power is at the mo- ment suspended, as in certain cases of concussion of the brain, &c. We know also, that the most important func- tions in the animal system are carried on quite independent _of the will. The heart for instance is continually acting, yet we are unconscious of it. There are many other mus- cles &c., which also act independent of the will, as the diaph- ragm, the muscles of the intestines, and even at times the sphincter muscles, &c. Hence some of them have been de~ nominated involuntary muscles. We have now seen then; that motions go on in the living animal system without the concurrence of the will, and yet that the parts are highly ir~ ritable. Bearing this idea in mind, cannot we conceive, that * Sennebier’s Physiologie Vegetale, tome Y, p. 87. + Physiol. Vegetal. tome V, page 120., the 264 ‘The author’s definition of the term. Plants experi- mented on by the Suir. Leaves of roundleayed sundew de- scribed. ON THE IRRITABILITY OF VEGETABLES. the motions of plants-may still be owing to irritability, al- though there is no mind to regulate them? I do not mean here to say, that plants have not a voluntary power; but merely admit that they have not in the present question. Wildenouw, when treating of the powers which vegetables ossess, speaks thus on the subject. ** Irritability, when Pp ‘ ' 5 ‘© diffgrent stimuli produce a change in the parts of a body, “© which without it would not have taken place*.” The following definition seems to me as comprehensive and‘accurate as any, and’shows the meaning in which the word irritability is used in the following pages. By irrita- bility then I understand that property inherent in some bodies, (or rather parts of bodies) by which, when a stimu- lus is applied, they are enabled to contract. Having thus fixed the definition, let us proceed to the im= mediate subject of the paper. The plants on which I made my experiments were the drosera rotundifclia and longifolia, the eupborbia helioscopia, and the dionosa muscipula. The species of drosesa come first under consideration; but before speaking of the moving power of their leaves, I think it ne- cessary to give a ininute description of them: and Ist of the rotundifolia. The leaves of this plant, when properly unfolded, lie round the stem in astellated manner. The footstalks of the leaves vary in length from half an inch to one inch and half. On the upper side they are a little roundish, and have at the same time a two edged appearance. The under surface is quite flat, and bounded by the two edges just mentioned. They are of a reddish colour, aud are covered by a great pumber of long white hairs, spreading in d:fferent direc- tions. They may be bent considerably without breaking, and, when the resisting force is removed, resume their for- mer situation. At the end of the footstalks we find the leaves generally of an orbicular shape, hence the specific name of the plant. The under surface,of the leaf is in the game plane with ‘the under surface of the footstalk, (indeed it is difficult to say where the one ends and the other begins) has a somewhat membranaceous appearance, and is in gene- ral of a greenish (though sometimes purplisk) colour. The * Princip]. Botany & Veg. Physiol. Wildenow (Translat. p. 219.) upper ON THE IRRITABILITY OF VEGETABLES. 063 upper surface is covered with hairs, but when deprived of them appears nearly like the under. The leaf itself is verv thin, and may be folded in different directions without breaking. The hairs, which cover the upper surface of the leaves, are of va-~ rious lengths. Those on the margin are sometimes three eighths of an inch long, while those in the centre are not more than one line. In some well expanded leaves we may see nearly a regular gradation of the intermediate hairs be- tween the two extremes. The marginal hairs are flattish at their base, and of the same colour with the leaf itself, (in- deed they seem to be merely continuations of it), The other hairs are not so fiat at their base as the marginal ones, but are also of the same colour as the leaf. The long hairs, except at their base, are of a red colour, each terminated by a little knob; while in the central hairs the knob is placed immediately on the white part of each. Every hair then is terminated by a little rounded body. In general each of these knobs is covered by a transparent and viscid fluid, which gives a fine appearance, and on account of which the plant was denominated ros solis or sundew. Each of these knobs appears to be a little gland, which secretes the viscid fluid* for a purpose soon to be mentioned. The chief difference between the leaves of the longifolia 7 ongteayed. and the rotundifolia is in the shape, those of the former _ being obovate. * This fluid, which covers the glands of the hairs (of the leaves) of Fjuid of dro- the indigenous species of drosera, has been differently , denominated. sera. Darwin talks of the peliucid drop of mucilage on every thread of the _ fringe, and in the same page speaks of the globules of mucus. Bot. Gard.’ Roth calls it the clammy juice, and Ihave here called it a trans- -parent viscid fluid. This juice covers the glands when under the influ- ence of the hottest sun; and also during the wettest weather. When procentsa the leaf is put under the electrical influence, each little globule of fluid beautiful ape spins out like a small tree, presenting a fine appearance, This duid eee seems to possess the fullowing properties, although I cannot vouch for en the accuracy of the experiments. It is transparent, insipid, rather more ‘ consistent tHan the albumen ovi, extremely ten cious, inselubie in wa- ter, soluble in alcohol, in diluted suiphuric acid, a. d in so.ution of po- tash, is not very combustible, and is an electric or nonconductor. Quere, Is it a fluid sui generis? 1t certainly deserves the attention of the che- Its properties. mist, The 266 Mr. Whately noticed their contraction when irritated. This described. ON THE IRRITABILITY OF VEGETABLES. The £rst mention of the contraction of the leaves of the species of drosere, at least in this kingdom,when irritatea,will be found inWithering’s Botany (vol. 2d p. 324) from which it would appear, that Mr. Whately discovered this curious phenomenon in August 1780. Mr, Gardom, who was with Mr. Whately at the time, gives the following account of this contraction in a letter to Dr. Withering. ‘* In August, «©1780, examining the drosera in company with Mr. *¢ Whately, on his inspecting some of the contracted leaves, «* we observed a small insect or fly very closely imprisoned *‘ therein, which occasioned some astonishment, to me at .* least, how it happened to get into that cenfined situation. *¢ Afterward, on Mr. Whately’s centrically pressing with a <¢ pin other leaves yet in their natural and expanded form, «© we observed a remarkable sudden and elastic spring of the “< leaves, so.as to become inverted upwards, and as it were “* incircling the pin, which evidently showed the method by *€ which the fly came into its embarrassing situation. This Roth observed it earlier, His account of it. “‘ experiment was renewed repeatedly, and with the same ‘effect, so that Mr. Whately and myself are both certain § of ithe fats?! « Roth published his work entitled Beitrege zur Botanick ~ in 1782, from which Dr. Withering translates the following remarks. ‘ July 1779. Drosera rotundifolia and longifo- *“ Ha. Tremarked, that many leaves were folded together ** from the point towards the base, and that all the hairs «¢ were bent like a bow, but there was no apparent change «© in the leaf stalk.. Upon opening these leaves, I found in each a dead insect. Hence I imagined, that this plant, «‘ which has some resemblance to the dioncea muscipula, « might also have a similar moving power. With a pair of «* pliers I placed an ant upon the middle of a leaf of the «© drosera rotundifotia, but so as not to disturb the plant. ‘s The ant endeavoured to escape, but was held fast by the.. <¢ clammy juice at the points of the hairs, which was drawn « out by its feet into fine threads ; in some minutes the short bairs on the disk of the leaf began to bend, then the long hairs, and laid themselves upon the insect. Af- “ tera while the leaf began to bend, and in some hours the end of the leaf was so bent inwards as to touch the base. 66 The an ‘ « a n é na ON THE IRRITABILITY OF VEGETADLES. 67 s¢ The ant died in 15 minutes, which was before all the hairs ‘© had bent themselves. On repeating this experiment, I «* found the effects to follow sooner or later according to the “© state of the weather. At eleven in the morning a small *¢ fly, placed in the centre of the leaf, died sooner than the *¢ ant had done, the hairs bent themselves as before, and at ** five in the evening the leaf was bent together, and held «< the fly shut up. The same experiments being made on << the drosera longifolia, the same effects followed, but more “ yapidly. I observed, that in sultry weather, and hot snn~ ** shine, when the drops of juice upon the points of the © hairs are largest, the experiment succeeds best. If the insect beasmall one, sometimes only one edge of the leaf is © folded up; hence it should seem necessary, that the in- sect should stir all the hairs of the leaf.” Roth also found, that the hairs bent themselves when he Found to con« touched them with the point of a needle, with a hog’s bristle, tact when &c.; but that they returned to their former position after a eo oe i certain time. He remarked the same contraction when he placed a piece of wood the weight of an ant upon the leaves ; but that the impression made by the point of a needle re- mained longest. Although Withering points out the most ‘of these circumstances particularly with a view to excite the attention of botanists to the species of drosera, yet I have not met with any account of experiments made since the time he wrote, in the year 1796. For the last 5 months of the present year I have almost pho contrac. every day had these plants under my eye, either at home or tion takes ‘abroad in the country.. For my own part I must confess, i, that I have never seen.that rapid contraction of the leaves of the drosera rotunda, which is mentioned by Mr. Gardom;* but in all the experiments which I have made, I have ob- ‘served that the contraction was gradua!, though it seldom - failed to happen, if the plant was in good condition, In some plants I have seen the contraction take place in nearly the time mentioned by Roth; but in most cases it has hap- pened, that an honr was necessary for the complete bending -of all the hairs, and that it required some hours more fai the perfect shutting up-of the leaves. In some plants f have seen the hairs and leaves nearly expanded even some hours 26s Experiment faded with Dr Wrtherwig - probably be. cause he did not wait long enough. Manner in which the con- traction is ac- eounted for by Broussonet. ON THE IRRITABILITY OF VEGETABLES. hours after the stimulus was applied, and yet in the curse of a few more hours both have contracted completely. The last experiments were made within doors, and probably the plants, though to appearance pretty fresh, were not in the most irritable state. Dr. Withering mentions, that Mr,Whately’s experiment ~failed in bis hands, and from Roth’s and the above obser= vations we possibly may account for this. From what Mr. Gardom has said, he no doubt expected a sudden contraction of the leaf when irritated ; but not finding this to happen, he probably concluded, that the plant was not, in good condition, and, from placing implicit faith in Mr. Gardom’s experiments, was not anxious to repeat them. I do not mean by what I have said, to impute to Mr. Gardom any inaccuracy in the relation of his experiments, but merely to put others on their guard, who wish to make experiments on this plant. From what I have said it ts evident, that whoever has a wish to notice the motions of the leaves of the droserz must not set out with the expectation of seeing a rapid motion (similar to what happens in the mimosa) follow the application of a stimulus; but, to ob- serve the ultimate effects, must watch with an attentive eye for at least, in general, 20 minutes. It is then that he will behold the bending of the hairs, which will soon be ac- companied with that of the leaf. Having now considered the motions of the leaves of these plants, let us examine the manner in which they are ac- counted for. Broussonnet, in a memoir of the Academy of Sciences of Paris for 1784, suspects, that the disengage- ment of some fluids mfluences these motions. As Broue sonnet’s theory is quoted by Sennebier, [ shall translate the words of the latter. After speaking of the dioncea musci- pula, he says: “ He (Brousconnet) remarked the same ** phenomena upon two species of the drosera; their leaves ‘“* at first being folded upon themselves, their juices are not “ carried immediately towards the little: hairs which cover ‘‘ them, but after their developement we can perceive a «¢ drop of fluid towards the extremity of each hair; the in- < sect absorbing this fluid, empties the vessels of the leaf, ** which folds upon itfelf, and resumes its former position : a the ‘ ON THE IRRITABILITY OF VEGETABLES, 269 * the quickness of this action is then proportional to the «* number of hairs touched by the insect *.” This theory at first reading does not appear even to be This theory plausible; for how is it possible, that an imsect can absorb not plausible, a thick tenacious fluid? No doubt however part of this fluid will be attached to the part of the insect which touches it, but this seems quite unconnected with the contraction of ene see the leaf, as I shall immediately show. On the 30th of July ent with facts. J brought from rhe country a number of plants of the dro- sera rotundifolia, and on inspecting them I found many of the hairs deprived of their viscid fluid, but yet both they and the leaf remained quite expanded and im good condi- tion, ‘This appeared to me a favourable opportunity, to ascertain either the accuracy or inaccuracy oi Hrousonnet’s theory. Next day in the afternoon about four o'clock, when rather clondy and the temperature moderate, I placed a small bit of sulphate of copper in the disk of one of these expanded leaves. Now if Broussonnet’s theory was accu- rate, I conceive, no effect should have taken place ; but on the contrary by six o’clock most of the hairs on one side of the leaf, even the outermost, had bent themselves complete- ly over the morsel of sulphate of copper. I have repeated this experiment frequently, and always with the saine result. It may be well also to observe, that in other experiments the sulphate of copper rested upon some of the small hairs in the disk of the leaf without touching the leaf itself, yet the bending of the hairs and leaf was complete. In some lants also, in which every hair of the leaf has been*‘covered with a drop of viscid fiuid, 1 cautiousiy placed a small bit of bread, or wood, on three or four of the central hairs with- | out touching the other hairs, or the viscid fluid on their ends, and in the course of a few hours I found, that all the hairs had contracted around the foreign body. ' We have here proof then, Ist, That the leaves do not Conclusions contract when deprived of this viscid fluid ; which ought to fo™ them. have been the case, if Broussonnet’s theory had been accu- vate. Qdly, That the contraction takes place even when the finid does not cover the little glands. 3dly, That the con- * Sennebier, Physiol. Veg. Tome V, p. 117. traction 870 ON THE IRRITABILITY OF VEGETABLES. traction follows, although the foreign body 1s not brought into contact with ail the hairs. Apparent mis- "This last conclusion is contrary to what is mentioned by take of Roth. : : : : Roth. He says, “ if the insect be a small one, sometimes “<< only one edge of the leaf is folded up.” Hence it should seem necessary, that the insect should stir all the hairs of the leaf. Emptying the In the experiments mentioned no inseet or any other See body absorbs the fluid, and of course the vessels of the leaf contraction, cannot be emptied, which is completely in opposition to Broussonnet’s theory. Sennebier’s We shall next quote Sennebier’s own opinion with regard hypothesis. ‘to the contraction of the leaves of the drosere. He says; ‘ The hairs of the flowers” (he certainly means leaves) * of «* the droserze are put in motion by a hair, aneedle, an ant, ‘ or small bit of woed. It appears then, that the pressure «‘ alone is the cause of it, and this effect permits us to ‘ ascribe it to a cause purely mechanical *.” I am willing to agree with the first part of this sentence, but from the latter 1 must entirely dissent. Sennebier seems sensible, that the contractions of the leaves take “ nan n ' His facts true, place even when light bodies are placed upon them, which of itself would even lead us to suspect, that pressure is not alone the cause. I know, that, if we press on the centre of the leaf with a pin &c., we may cause its margin to approxi- mate the pin; and this certainly would be owing to a me- chanical cause. But suppose we see the contraction take place, as 1 have done, when a body specifically lighter than the leaf itself is placed in the centre, as a bit of rotten wood ; should we be still inclined to ascribe it to a mechanical cause? Admit that it is the case. Suppose then we place the same bit of wood on the margin of the leaf, what effect ought to follow? Ifit was owing to a mechanical cause, or the weight of the forcing body, as in the last mentioned case, then we should expect, that the part of the margin of the leaf, on which the bit of wood rested, would be depress- ed; which undoubtedly is not the case, but on the contrary | the margin rises, and then contracts toward the foreign * Physiol. Veg. tome V, p. 104, body, ON THE IRRITABILITY OF VEGETABLES. 971 body, or toward the footstalk of the leaf*. This would seem then to prove, that pressure alone can never be the cause of the contraction of the leaves of the droseree, and consequently, that the action is not owing to a cause purely mechanical. Having now seen, that the action of these leaves cannot The motion be accounted for either by the theory of Brousonnet, or Cena that of Sennebier, to what must we ascribe them? It ap- table and equi- pears to me, that the motions of these leaves must be owing ag ae to some other cause, and -this cause a moving onet, deno- minate it what you will, for we must admit, that these leaves contract in consequence of the application of a stimulus; - and I conceive, that this action is performed, if not by muscles, at least by something which is equivalent to mus- cles in the animal body. I have seen no other attempts to prove; that the contrac- The principle tion of the leaves of the drosere is owing to any mechanical NB da fy action ; and other authors seem disposed to admit it as a mitted by se proof of vegetable irritability. Among these authors we Yel. have the illustrious Dr. Smith, who seems to think, that the - motions of the leaves are to be explained on the principle of irritability+. We have also the no less celebrated Wilden- ouw, who, immediately after mentioning the irritability of ‘ the mimosa, dioncea, &c., says: ‘ Less conspicuous, but &° easily demonstrable, is the irritahility of the indigenous «< species of sundew, drosera rotundifolia and longifolia§.” IT will now conclude this part of the paper by quoting the words of Dr. Smith, which he uses when speaking of the mimosa, &c. : “it is vain to attempt any mechanical solu- * That this motion does not depend on pressure may be still better il- lustrated, by placing a fly, or some other body, on the apex of a leaf of _ the drosera longifolia. The hairs near the foreign body will contract around it, and then the apex of the leaf will rise upwards, and turn in- wards, until it touches the base. Or if the offending body is small, the leaf will become convoluted around it. + I mean a cause, which produces motien, I Philos, Trans, abridged, vol. XX!, page 243. - § Paincip. Botany and Veg. Physiol. (Translation) page 222, edt. 1805. , tion” ts) “ah ts What is the the fina) cause of this power? Darwin sup- poses it intend- ed to keep off Imsects. More probably for the purpose of catching chem. Leaves of the drosera well adapted for this. ON THE IRRITABILITY OF VEGETABLES. ** tion of the phenomena mentioned”, -(Introduct. to Bo- tany.) Having found, that the leaves of the drosera catch flies on the principle of irritability, it may be afked, what is the in- tention of nature in allowing these and a few others that ex- clusive power? At present I am afraid this question can- not be satisfactorily answered; but in pursuing the inquiry we ought first to fix whether the particular contrivances in the dioneea, drosera, &c., are intended for offence or de- fence. Warwin entertained the latter idea; for, after men- tioning the silene, he says: “In the dioncea muscipula ‘* there is a still more wonderful contrivance, to prevent the ‘* depredations of imsects.”” Again, when speaking of the drosere, he remarks, that, ¢ This mucus isa secretion from “* certain glands, and, like the viscous material round the «* flower stalks of silene (catchfly), prevents small insects ‘* from infesting the leaves.” I shou!d rather be disposed to think, that the leaves of the diencea and droserze were intended for offence, 1.e. for catch- ing flies; for if defence was wanted, nature, ever simple in her operations, could have supplied these plants with a much simpler apparatas, as a number of spines, which would have been quite sufficient for this purpose; while we cen- not conceive any contrivance, that would have answered bet- ter for catching flies, than what is seen in their leaves, Reasoning from analogy, this position will be strengthened, The sarracenia purpurea has tubular leaves beset at the margiu with inverted hairs, which, like the wires of « mouse trap, render it very difficult for any unfortunate fly, that. has fallen into the watery tube, to crawl out again. Now bad it been the intention of nature, that this contrivance was for defence—would it not have been much easier for her to have placed the hairs on the margin of the leaf with the points upwards, instead of inverted, which would have effectually prevented the insect even from touching the in- side of the leaf? Regarding then these contrivances for offence, we have found the structure of the leaves of the drosere admirably well calculated for this purpose. The glands are covered with ON THE IRRITABILITY OF VEGETABLES, ee Ry: : ia tS “SI o's) with a viscid fluid (probably) not ouly for alluring the little ifisects, but also for retaining them, until the contraction of the hairs (which is not immediate) shall begin. Now if the insect has been unable to overcome the tenacity of the fluid, it will soon be imprisoned by the hairs bending over it, and finally will either be killed by the contraction of the leaf, or retained in it until it dies. This contraction will continue ~ until all -is quiet, and even until the leaf becomes accus- tomed to its action, and of course suffers no farther stiru- tus; then most of the hairs and the leaf will expand and re- ~ sume their former situations. ‘This is the manner then by which the flies &c. are im- Of what use is the insect to prisoned ; but it may be inquired also, of what use are the |). plant? insects to the plants? [ think there can be little doubt, but that they are of some important use in the vegeta- ble economy, or why should so many thousand insects be ‘thus destroyed ? Dr. Smith in his introduction to botany, after mentioning an interesting circumstance concerning the sarracenia adiunca and purpurea, says: “ Probably the air “ evolved hy these dead flies may be beneficial to vegeta- ** tion.” Aud again: “ probably the leaves of the dioncea “muscipula, as well as the drosere, eatch insects for a similar yeason.” On this subject I can say nothing at present, but must think Dr. Smith’s explanation very ingenious, - and probably just: but [ cannot avoid asking one question, viz. As the flies in course of time are reduced toa pulpy state, Perhaps ab- both in the dionwa muscipula, and in the drusera, is it not ony an probable, that some of the pulpy mass may be absorbed, ; ‘and so prove as useful to the plant as the putrid effluvia? _—P.S. Since the above observations were written out, about five weeks ago, two papers ov the motions of veyeta- ‘bles have appeared. The Ist in a supplement to the 23d Mrs Ibbet- vol. of Nicholsoa’s Journal, and the 2d in the 107th num- $%’s theory ber, or that for the present mouth. The author of both is Mrs. Ibbeison, whose knowledyve, industry, and pevsever- ance deserve the highest evcomiums. She endeavours to explain not only the motions of plants, but also their sleep, their sensibility, and their volition, by the changes pro- Vou. XXIV.. Dec. 1809. T duncd ‘274 questioned, ON THE IRRITABILITY OF VEGETABLES, duced upon the spiral wires (before denominated spiral vessels), and what she calls a leatherlike substance, by the actions of heat, light, and moisture, I must confess, that Mrs. Ibbetson has brought forward some strong proofs in confirmation of her opinion; but at the same time I must acknowledge, that these proofs are not sufficient to convince me, “ that all plants are merely machines governed by light and moisture, and that every idea of their sensilility or of their volition, is only a proof, that we too often let our ima- gination run away with our judgment:” which is the opis nion of Mrs. [bbetson. On the contrary I am still inclined to believe, that plants are both sensible and irritable. As to volition, I avoid saying any thing of this at present. In pro- secuting this inquiry, it must be considered, that plants are living organized bodies ; and of course, that they are at least governed by the laws of vitality, if | may so express myself. No mechanical machine is governed by such laws. Mrs. Tbbetson’s opiaion with regard to the motions of the mimosa sensitiva is certainly ditferent from that which I eutertain; for admitting all the mechanical structure mentioned, consisting of “‘ different joints, pullies, knots, and bolts,” to exist in the moving parts of plants, and that its spiral wires are ca- pable of producing some of its motions ; yet I cannot con- ceive, that either heat, light, or moisture, can possibly re- gulate sone of the beautiful and striking experiments, which may be made either-on the mimosa sensitiva, m. pu- diea, or others. Indeed such a mechanical structure seems to approach too near to the feeble works of men, and ap- pears to me too complex (reasoning from analogy) to be the production of the author of nature, It is proper here to re- mark, that Mrs. Ibhetson’s observations are mostly micro- scopical, and hence J am induced to suppose (though with the greatest deference to Mrs. [bbetson’s superior. abilities) that possibly there may be some deception. But as I shall probably take the liberty of addressing a few observations on this important subject to Mr. Nicholson, after she has finished what she intends to write. J wust for the present decline saying any thing farther; except, that, should Mrs, Ibbetson well explain these observations, I shall then be ee ready ON THE IRRITABILITY OF VEGETABLES. ss “I Gr ready to retract my opinion, and with the greatest pleasure give to her the merit of having explained that which has puzzled many physiologists. On the Irritability of the Vessels of Plants. As almost every vegetable physiologist has treated of Ascent of the the ascent of the sap, and as the irritability of the ves- eh ee sels is intimately connected with this operation, this sub- tability of the ject becomes extremely interesting. Van Marum, in a ‘e's. paper addressed to Ingenhousz which is contained in the Journal de Physique for September 1792, notices some experiments, which had been made by Coulon, and then proceeds to mention some electrical experiments, which he himself had made on plants. He first makes a This irritabi- few observations on the destruction of the irritability of the lity, like that : j of muscles, de muscular fibres, and then reasons thus: If the contraction stroyed ie, of the vessels of plants is the effect of their irritability, it electricity. will be destroyed in the same manner as the irritability of the muscular fibres. Ie adds: “ [ tried if this would hap- ** pen in the summer of last year upon some species of eu- *¢ phorbia, which have the common property of giving out « much milky sap from their wounds. I caused the stream «© of the grand Teylerian machine to pass through the «© branches of euphorbia lathyrus, and through the twigs of “ euphorbia campestris, and eyparissias, and I observed, «< that all’ the branches or twigs of these plants, which <‘ conducted the stream or the electrical torrent during <* twenty or thirty seconds, absolutely when they were cut ' «did not give out any more sap from their wounds, * LT repeated these experiments with the branches of the “* fig-tree, which also gave out milk by their wounds, The «* elect was perfectly the same; the sap was vot seen to flow <¢ out when the branches were cut, after they had conduct- «* ed the electrical. torrent during five seconds; but when *¢ the electrified branches were pressed between the finvers, ‘* a little sap could be perceived to flow, which rendered it "* evident, that the electrical torrent had not emptied the <* electrified vessels, by forcing the sap towards the roots, T 2 “ but ~~ 276 Sennebier suposes this to be owing toa destruction of - the organizae tion : but this was not the fact, ON THE IRRITABILITY OF VEGUTABLES. «* but that the vessels had really lost the faculty of contract- << ing and ef expelling the sap which they contained.” — Sennebier, to account for these phenomena, observes, that electricity stops the passage of the juices im the branches exposed to its action by the shock which it occasions in them, which may derange their motions, and produce some change in the juices themselves. However strong ‘* the sparks, which suspend the flowing of the juices, I have suspected, that this suspension was produced by the disorganization of the parts of plauts which experienced its action, and that the extravasated juices were diffused into the spongy parts, which retained them. I commu- «© nicated this suspicion to Van Marum, who answered me, «‘ that an electric torrent could not destroy any thing by passing through a less perfect conductor, such as plants are, but especially when it was divided in such a manner s that the light of the electric fluid could not be perceived ; «¢ yet I insisted on his recalling to mind, whether he had seen any manifest disorganization in his experiments; and I desired him to make the experiment, and observe the — electrified parts with a magnifying glass.” Physiol. Vegetal. tome V, p, 111. Agreeably to this request Van Marum repeated the ex- periment, and answered Sennebier, that he saw no apparent rupture (disorganization) in the organs of the vegetable, Sennebier then confesses, that he regards the experiments of Van Marum as the most favourable argument for the ir- ritability of vegetables, and as the only one.against which 66 6 Li4 _ he has nothing to oppose. The milky juice of certain plants not their sap, buta pe- culiar secre- tion. If the-vessels containing it In setting out with experiments of this kind it 1s neces- sary to know, that what has been called the sap by both the authors quoted is now thought to be a peculiar secretion, Dr. Smith, in his introduction to botany, has placed the milky juice both of the fig and spurge along with the se- creted fluids of plants; and mentions, that Dr. Darwin has shown this fluid, quite distinct from the sap, to be, like ani- ma! milk, an emulsion or combination of a watery fluid with - oil or resin. _ Of whatever nature the juice of the euphorbia is, I do not mean at present to inquire; for this fluid must be contain- ed ON THE IRRITABILITY OF VEGETABLES, O77 ed in vessels, and if we can prove, that these vessels are irri+ be irritable, we table, then we can very easily transmit the analogy to the te oe sap vessels. The experiments of Van Marum go far to are also. establish the irritability of the vessels, which contain that secreted fluid; but the followmg, which I have made move than once, appear to me conclusive on the subject. Having a number of plants of the euphorbia helioscopia, Experiments I cut off the top of one, aud found, that the miiky juice flowed ° Be subject. copioufly. [now submitted this plant to the electric influence for some seconds by passing sparks * through it, which were so small as seldom to be visible. I then cut the stem about the middle. and but very little juice flowed. I next covered the end of the remaining half with a little moss, and placed the root in water. For some days it seemed languid, but in a few more began to recover. Soon after this I cut the stem across about two inches from the root, and the milky juice flowed abundantly. In this experiment then we find, ist, that the milky juice was expelled by the contraction of the vessels. Qdly, That the electrical fluid weakened the irritability of the vessels, but did not destroy it, or kill the remaining half of the plant: and 3dly, That after a certain time, when the plant had recovered from the shock, the milky sap was again ex- pelled by the contraction of the vessels. This experiment also shows, that Sennebier’s suspicion concerning the disor- ganization of the parts of the euphorbia helioscopia is groundless. I have repeated some of Van Marum’s experiments with Yan Marum’s the same results as himself. The last mentioned experi- ae ment, is rather a delicate one,’ for it is dificult to regulate the electric stream so as that it will only hurt the irritabi- lity of the vessels without killing the plant; but should it prove successful in the hands of others, I should then be disposed to think, that the irritability of the vessels, which contain this secreted milky fluid, will be established on a sure foundation never to be overturned. *_QOr rather the stream. lV. 78 | DMBONSTRATION OF THE COTESIAN THEOREM. he] ; IV. Demonstration of the Cotesian Theorem. By Mr. P. Barrow. To Mr. NICHOLSON. ena ened Oct. 13th, 1809. Cotesian theo- le the following demonstration of the celebrated theorem rem. of Cotes appear to you to possess a sufficient degree of ori- ginality, to entitle it to a place in your Journal, its inser- tion will oblige Yours, &e. Royal Mititary Academy, P. BARLOW. Woolwich. in Came TI was led to the consideration of this theorem from an conjectue of observation made by La Grange, in his Théorie des Fonc- what led Cotes |. } : : toit, suggested {tons Analytiques, where he hazards a conjecture as to the the demonstra- probabie circumstances that led Cotes to the discovery of tonher given. this elegant property of the circle; and by pursuing the hints there given I arrived at the fotlowing demonstration, which appears to me to be, at least, as satisfactory as any oue that I have at present seen; and on this I rest my apo- logy for intruding into the pages of the Philosophical Jour- nal a subject, that has so long, and so often, engaged the attention of many very celebrated mathematicians, without any of them having arriyed at what may be considered an unobjectionable demonstration. It will be proper, however, for the information of some of your readers, before we enter upon the demonstration, to state the theorem itself, which is as follows. Cyotes’s Theorem. Theorem. Let ABC, &e., Pl. VIII, fig. 31, 32, be any cirele, divided into any even number of equal parts, 2m, as A B, BC, CD, &c.; also let P be any point in the diameter, either DEMONSTRATION OF THE COTESIAN THEOREM. 279 either within the circle; or in the diameter produced, and jon PB, PC, PD, &c.,; then will PBxPDx PF &.= AO™+4+ PO" and PA x PC x PE & =AO"™m PO" Demonstration. It is a well known trigonometrical property, that by oe making cos. x =p, we may derive, eos; “& == p cos. 2x = 2 p*—1 cos. 3x = 4p?—3p cos. 4x = 8 pt— 8 p* 4+ 1 cos. 52 = 16 p> — 20 p?+ Sp &e. &e. See Bonnycastle’s Trig: p. 301: Now by substituting 2p=y+ = and multiplying each of the above formule by 2, they are reduced to the following simple forms: 1 O @0S. 90) == + — . ¥y 2 1 2 cos. 2x =y + > 4 ues & 2 tes. 32 = HY + y 1 pevex nek 1 SBR, Tg whence we may con- o 1 clude generally } 2 cos; mx ay" + 7m But as this general form is only deduced from observing the law of the leading forms, it will be more sa isfactory to see it derived in a direct manner: which may be done by means of the general formula. Cos. nx = 2 cos. x. cos, (n— 1) r~= cos. (n = 2) x. Bonnycastle’s Trig. p. 300. Or 250 ° DEMONSTRATION OF THE COTESIAN THEOREM. Demonstration Or making m1 == m, and transposing, we have ‘ of Cotes’s theorem, 2 cos. x X 2 cos. max = 2 cos. (m— 1) x + 2 cos. (m+ 1) 2 u ; ] ay When, by making 2 cos. x = y +—, and admitting, that y ; ] in any Case, 2 cos. (m——1) x = y™=' +4 ee and 2 cos. 1 : mx = ym+ 7 (which we know to be true when m= 2 from the sbove forms), we shall find that 2 cos. (m +1) a= ym +} “9 that is, 1t will be of the same form with re- gard to the multiple m-+1, which may be shown as fol- lows. In the foregoing general formula, by substituting for 2 cos. x, 2 cos. (m—1) x, and 2 cos. mx, their respective values y + - yee a and y™ ra we have, 2cos.(m-+1}e=(y™+ =) x G+>)= (y m— i the latter side of which equation being reduced gives 2 cos. (mt) eget! + yar that is, it is of the same form with regard to its multiple as the two preceding forms; and since we know that those are true when m= 2, or when m= 1, it follows, from what is said above, that it is true when m=3, and consequently also when m= 4, and generally for any value of m We may therefore conclude with certainty, that if 1 2 eps. ay y 1 that 2 cos. mx = y™ + oe . From which we readily deduce the following equations = ist, y*—2ycos.e+1=0 ‘ 2d, aes adie at allt Now ‘DEMONSTRATION OF THE COTESIAN THEOREM. 28) Now these equations must necessarily have one common Demonstration a of Cotes’s root, being both obtained from the same value of y; an choosen farther, since both equations are reciprocal ones, if y be Wau! ks : one root, — is another root, and the first equation having y. but two roots, and such of those being also roots of the se- cond equation, it follows that the former of our formule is a divisor of the latter. And this is true, if we change y into gy, without, however, altering the value of 2 cos. x, and 2 cos. mx; for by substituting for these their true value 1 y+ Pi and y™ + = and q y for y, the above formule are reduced to Ast (1) ig 1) ed, (g™y?™—1) X (g™—1) The former of which is evidently a divisor of the latter, en- tirely independent of the value of q, or of the measure of the angle represented by x. ; 3 mx tne We may therefore, instead of x, write —-——, then m our formulz will become Py —agy cos. (MEL) 41 g?™y2™—2q™y™ cos. (mx+ne)+1 The former being still a divisor of the latter. We may here also observe, that while ¢c represents the en- tire circumference, the cos. (m x + nc) = cos. max, what- ever integral yalue we give to n; and hence making re- spectively n=—0, 1, 2, 3, &c, m—1, it follows, that the formula gem y?™ — J g™ y™ cos (m x + nc) +1, has for its divisors the m yee Lio - Stes gf ¥ 60%- ae) +1 gy —2qy cos. (met) $1 sige mx-+2e — i . — -] 179 2a y cos: ( me )4 282 DEMONSTRATION OF THE COTESIAN THEOREM. Demonstration mx-+ 3c of Cotes’s q y° —24y cos. ( oa ) $A theorem, , ne z qty? = 2qy cos. (te + m—l1. “+ 7 Since then our first formula of the 2 mth degree has for its divisors the above m formule of the 2d degree; it fol- lows, from the nature of equations, that itis equal to the product of these m formulx. c Now by making mx=0, and mz = are have 2 cos. mx == -+- 1, and the general form is reduced to this parti- eular ene, : (q™ y™ + 1)% which is the Cotesian theorem. For in the first case, making mr = 0, it becomes cg 2a having for its divisors, 2 y* —2qy Cos eG 1 iE ie it an Zc gy —2qy cos. (—— ) +1 2m gy? —2qy cos. (4) a au. &e. &e. And secondly, making mx = > we have for our formula tas its divisors being 2 yt te q y 2qy cor. () fl ee {se q yr 2qy cos!( ><) + 1 2,2 =) q y —2¢y cos. (= +1 &e, &e. FLAME DIMINISHED BY ELECTRICITY. 283 ‘ . . ; ae ¢ 7 Or using radius r, instead of radius 1, and writing —— Demonstration r > 2m Ff Cotes’s — x, we have thevrein,. gy —2qyr cos. 0x$1 gy —2qyr cos.2x41 gy —2qyrcos. 4x41 &e. &e. formula (q™ y™ —7™)*, and divisors And also q° yy —2g yr cos. r+ 2 formula (q™ y™ + 7™)”, and divisors ‘ Fag pees. S Bed a y—2qyrcos.5x4+1 &e. &c. Now the first set of these divisors agrees with PA*, PC’, PE’, &c. in the above figures; and the second set with P BY, PD’, PF, &c. For since g is undeterminate, make gy=OP,7r=OB, also r.cos. x= OQ; then by (Euclid 13, 2) - P B*=P0?—20QxOP+OB’; and it is exactly the same with all the other divisors. Since therefore (0 B™ — P O0™)* = P A*x PC* xX PE? &c. and (O B= + PO™)*= PB*xPD’*x PF’ &c. also OA = OB, it follows, that . OA="n PO"=PAxPCxPE, &a. aud, OA™—= PO"—PBxPDxPF,&. ¢ Q. E. D. Vv. On the Influence of Electricity on Flame: by Mr. Leopotp Vacca, Colonel of the 32d Regiment of Light Infantry*. Fume has been much used in electrical experiments, Effect of elec Se scity tricity th but 1 do not know, that the effect produced by electricity eka pF acai on the figure of flame has ever been noticed. net baat. We know, that, if water dropping from a slender siphon Water drop- ; : : ; : “! ing converted be electrified, the dropping will be changed into a stream. aa leak, * Journal de Physique, yol. LXV, p. 224. : We 284 or made to spout farther by it. Flame may be supposed to be enlarged by it: but experi- ment shows the con- trary. Electricity is- suing from points repels them Ly its ace tion on the air; and in the same maimer repels the Hame. FLAME DIMINISHED BY ELECTRICITY. We know too, that if a stream of water be electrified, its velocity will be increased, and it will describe a larger: pa- rabola. The reason of these phenomena is well known: they depend on the mutual repulsion of the particles of the water, all of them being electrified with the same kind of electricity. . Hence it might be expected, that, flame being an as- semblage of very subtile particles, if we could introduce into it electricity of one kind, they must repel each other, and consequently the flame be enlarged. To satisfy myself of the fact, I took a small vessel of metal filled with spirit ef wine, and insulated it. By means of a metallic chain | formed a communication between the vessel and the conductor of a good electrical machine of glass. I kindled the spirit of wine without moving the ma- chine, and observed the shape and magnitude of the flame. I turned the handle of the machine, and perceived, that its action occasioned a very considerable contraction of the flame. When I suspended the action of the machine, I found, tbat the fame resumed its former dimensions. This experiment, a thousand times repeated, constantly afforded me the same results. I was at first puzzled to account for this, but I think I have at length hit upon the true cause.’ We anit that electricity issuing out of a bedy to tra- verse the air repels it nearly in the same manner as powder repels the gun barrel in which it is burned. We know, that by means of points dispersing in the air the electricity accumulated in a star of metal very movable on a pivot we occasion the star to turn very rapidly in a direction con- trary to that of the points. We know too, that on this principle Ferguson constructed a planetarium, which was set in motien by electricity. We know also, that no sub- stance disperses electricity more than flame does, If then electricity escape from all the points that consti- tute the surface of flame, these points must be repelled back into the Hame; consequently the flame will be com- pressed, and its volume diminished. VI. ACTION OF PHOSPHORUS ON ALKALIS. O85 AeA Of the Action of Phosphorus and oxigenized muriatic acid Gas on Alkalis; by Messrs. BourLtoN-LAGRANGE and - VeGEL*. . Some years ago we perceived, that, after having obtained Phenomena of “ hey : phosphorus a pretty large quantity of phosphuretted hidrogen gas from heated with heating a mixture of phosphorus with pure caustic potash potash observ- dissolved in water, a blackish substance remained; and to- aE ee _ ward the end of the process another gas was evolved, which no longer inflamed on contact with the air. This circumstance not appearing of sufficient importance Occurred again for us to pursue it, we had thought no more of the memo- rales randum made of it, and should probably have neglected it still, had not the same phenomena occurred agaiu lately, as we were lecturing on phosphorus. Struck at the same time with the discovery of Mr. Davy respecting the nature of alkalis, we could no longer look with indifference on the facts we perceived anew. | We do not mean to discuss before the Society the decom- Seda decom- position of potash by the processes, that Messrs. Thenard, ep dee iy Gay-Lussac, and Curaudeau have employed. We shall only observe, that we have repeated in presence of the pu- pils, who attend our chemical lectures, the experiment of the decomposition of soda by charcoal in a gun barrel, as we had seen it performed by Mr. Curaudaut, and suc- _ceeded completely. The experiments we are about to sub- Experiments mit to the Society were made with phosphorus on potash oT and soda. ‘At present we shall content ourselves with ex- hibiting the facts as we observed them, carefully abstaining from all conjectural theory, persuaded, that, to attempt explanations not grounded on incontestable facts, or requir- ing interpretation, must give rise to errours, which, instead of advancing science, only tend to render our notions un- certain. * Annales de Chimie, May 1808, vol. LXVI, p. 194, + See p. 57 of our present volume. 286 Preparation of phosphorus for mixing it with alkalis Purity of pot- ash best ascer- tained by ba- rytes. water. = Mixture of the phosphorus with potash, 4 Caustic potash precipitates from lime wa- ter carbonate of lime that is soluble. ACTION OF PHOSPHORUS ON ALKALIS. To obtain the mixture of phosphorus with potash, which appeared to us impracticable unless by the method we shal! mention, we fused phosphorus in a phial into which we had put some warm water. The phial was shaken till the water was cold; to accelerate which we immersed it in cold water, after a little while, still continuing to shake it. Thus the phosphorus was reduced to the state of powder. The su- pernatant water-being decanted off, it was replaced by di- ‘luted oximunatic acid. "This acid, we are taught by Mr. Juch of Wurtzburg, has the property of depriving phos- phorus of carbon, if it be true that it contains any. From coloured it becomes white, and in this state the acid is to be separated from it, aud the moisture absorbed by blotting paper. On the other hand we satisfied ourselves of the purity of the petash by treating it «fresh with alcohol, and, after fu sion, testing it with lime water and barytes water. We shall here observe, that lime water is not a certain test’ for determining whether potash retain any carbonic acid; for, if the mixture be diluted with water, a simall quantity of carbonate of lime will be dissolved. This solution does not take place with barytes, and the smallest quantity of carbonate of barytes is always visible, which renders this substance preferable to lime for examining potash or soda*, Caustic potash was reduced to powder in a giass mortar, and then an equal quantity of phosphorus, prepared as above, was added. ‘Io aveid the combustion, which took place before the temperature was lowered, we placed the mortar in a mixture of powdered ice and muriate of soda. A slight trituration was sufficient, and the mixture was im- mediately introduced into a coated stone retort, which was * It has long been known, that a concentrated solution of caustic potash is precipitated by lime water, and that this precipitare is soluble in a large quantity of water; whence it has been inferred, that the pote ash merely took the water from thelime, and the latter fell down in the caustic state. But we have feund, that this precipitate is in fact a car- bouate of lime, which, thus intimately divided, is soluble in water, We have observed too, that this solution is not owing toan excess of alkali, for, after passing ca:bouic acid gas ito lime water, the precipi- tate separated was equally soluble in water, yet the liquor was neutral, | placed ACTION OF PHOSPHORUS ON ALKALIS. , 287 aa placed on the grate of a reverberatory furnace. A tube of Heated ina safety was fitted to the Leak of the retort, which communi- Stone retort. cated with a jar filled with mercury. The whole being thus nrranged, a gentle heat was applied. his first degree of heat sometimes occasioned the combustion of a small por- tion of phosphorus; bat this may be prevented by coyer- ing the mixture with a little powdered potash, It is easy to conceive, that this combustion is owing to the air con- tained in the retort; and that, when the caloric has occa=- gioned a vacuum in the apparatus, no combustion can take place, Of this we satisfied ourselves by a direct experi- ment. We afterward increased the fire, till the retort was of a white heat. _ During the whole course of the process, a gas was Gas evolved, evolved, the properties of which we shall mention pre-_ sently. When the retort was completely cold, we broke it, and Residuum. found in it a black mass. Its inside was entirely covered with a coat shining as if metallic, and having the appear- ance of carburet of iren. The black matter has a slightly alkaline taste, and was Jts properties. but little soluble in cold water. By means of boiling how- ever we dissolved it all, except a black powder, which was . precipitated. Boiling nitric acid likewise dissolves it; and a black matter, which is nothing but oxide of carbon, sepa- rates in a similar way. Neither of these solutions contains any thing but phos- phate of potash. Among the various experiments we made there was one, Residuum net in which we obtained a similar black mass, but without any @!kaline. perceptible taste. Water had no action on it. Nitric acid dissolved it, and separated from it oxide of carbou. ‘The portion ef the tube communicating with the retort was hned with a grayish substance, which tcok fire on coming juto contict with water. As to the sait that remained in tie retort, it was nothing but neutral phosphate of potash, which we know to be nearly insoluble in water. In the course of these experiments we employed alter- Soda gave the nately potash and soda, and instead of a stone retort, a re- °° revel tort and tube of porcelain. The results were the same. The £88 Properties of the-gas. Easy. method of procuring this gas. Residuum. Difference of the results if water be pre- sent. Oximuriatic acid gas passed through potash , at‘a white heat ACTION OF OXI? UPTATIC ACID GAS ON ALKALIS. The properties exhibited by the gas mentioned above’ were: J. It was neither acid nor alkaline. 2. It had a slight alliaceous smell. 3, It took fire at the approach of the white flame of a taper, and formed by this combustion’ a little phosphoric acid and oxide of phosphorus. | 4. It detonated loudly, when mixed with oxigen gas, and touched | by a substanee in the state of ignition. 5. It did not take fire on coming into contact with the atmosphere, with oxi- gen gas, or with nitrous gas, 6. It was a little soluble in water; and in this solation nitrate of silver oceasioned a blackish precipitate. 7. It inflamed rapidly when mixed with oximurtatic acid gas, and afterward deposited a little oxide of phosphorus on the sides of the jar. This elastic fluid may be procured in a simple and easy. way. It 1s sufficient to put a little phosphorus, cut inte small pieces and very dry, into a common phial; to strew over it perfectly dry caustic potash; and to adapt to it a. eurved tube opening under a jar filled with mercury. On heating the phial gently white vapours will form. -without inflammation, and the gas will be evolved. The tempera- ture 1s to be raised gradually, till no more bubbles pass, There will remain in the phial a black substance, slightly alkaline, containing phosphate of potash. There is a very striking difference when a little water 1§ added to the mixture. As long as any moisture is present, we obtain phosphuretted hidrogen gas, which inflames on the contact of air: but as soon as the matter is dry, if the action of the fire be continued, the gas evolved no longer in- flames by the contact of air, and has all the properties of that “bove mentioned. This difference in the results no doubt deserves examina= tion, and perhaps may be explained without any hypothe- sis. The same may be said of the followmg experiment, which may serve to elucidate the phenomena above de- sermbed, Two drachms of pure potash were introduced into a por- celain tube’. passing through a reverberatory furnace. Through this tube, brought to a white heat, was transmit- ted oximuriatic 4cid gas, expelled from a matrass into which the proper ingredieats had been put. Am intermediate : ’ phial, Se ACTION OF OXIMURIATIC ACI Ges ON ALKALIS, 289 phiai, withont water, received the vas before it reached the porcelain tube; and the other extremity of the tube cou- municated with a poeumato-chemical apparatus. The Moment the oximuriatic acid vas had reached the Aqueous va- potash, a great deal of water passed inco the jar in vapour Poe ast Pass not easily. condensed. When condeused they left behind muriatic acid carbonic acid gas. Some tine after oximuriatic acid vas pangs was perceived in the jar. On examining it a copious pre- mixed with cipitate was obtained with lime water and barytes water, Seen soak) but it was necessary to employ them in excess. ‘Toward the end of the process no more oximuriatic acid gas passed over, but a mixture of oxigen and carbonic acid gas. Carbonic acid gas therefore was disengaged during the whole course of the operation, taking place at its three dif- ferent periods; first with the water in vapour; secondly with the oximuriatic acid gas; and thirdly with the oxigea gas. All these gasses were cloudy, and did™not become transparent till the water was deposited. The quantity of carbonic acid gas, collected and sepa- Teo much care bonic acid to rated, appeared to us too great to be ascribed to the acid, yiye heen ree that the potash retains. Besides, we employed an’ alkali tained in the we had carefuliy purified; and the acid it could contain, patishs for whatever precaution is teken it cannot be perfectly freed from it, was ouly to be detected by barytes water, which gave only a slight cloud, scarcely perceptible. We have not however any design, still less the presump= Probably the alkali contains carbon and his potash: though from this experiment we might be tempted diogen. > tion, to attempt to establish or determine the principles of to suppose, that hidrogen and carbon exist in this alkali in certain proportions. In the porcelain tube we found muriate of potash in thin Moriate of pot- white laminz but slightly adherent. Some of them were ly a pose wy tinged of alight green. The weight of this salt was much than the alkali inferior to that of the potash employed, employed. It follows then, that all these experiments, if of little importance in themselves, may lead us to examine with more attention the chauges, that take place in kubutanees: when placed in contact with others at temperatures more or less, elevated. Vou. XXIV.—Dec. 1809. U The 290 ANALYSIS OF ONIONS. Potash treated The action of oxigen gas and hidrogen gas on potash has with oxigen & 1+ ewise presented us with s ‘ph a, of which hidrogen gas, K s€ presented us wl some p enoinena, Of Whic we shall give an account. ' VII. On the Chemical Analysis of the Onion: by Messrs. Four- cRoY and VAUQUELIN*. Liliaceous Aone the plants that compose the very natural fa- ee mily of lilacew, and seem to have the same interior organ- yet widely dif. ization, there are some, which, as the onion, differ essen- ee bed tially in their taste, smell, and almost all their properties. The authors of the paper, of which we shall here give an abridgment, had in view to seek the causes of this difference. Beside the solution of this problem, their investigation in- cludes several chemical facts of great importance to the pro-_ gress of vegetable analysis. Properties of The onion, allium cepa, grated to a pulp, and subjected a acai to the action of a press, gives out a white viscid juice, somewhat opake, of a strong smell, colourless the instant it is filtered, but acquiring a rosy hue from the contact of the air, on account of the oil it contains. It is perceptibly acid. It is precipitable by the acetate of lead, lime, oxalic acid, nitrate of silver, and potash. Dihistilled it yields a milky water, slightly acid, with a few drops of oil floating on the surface. The water diss The water distilled from onion juice has a strong smell, ae! ete hak and forms a light yellow precipitate with acetate of lead. sulphur. Two experiments were sufficient to prove the existence of sulphur in this hquor, 1. Oximuriatic acid makes it clear, deprives it of its smell, and gives it the property of preci- pitating nitrate of barytes. 2. This liqnor, distilled in a copper alembic, forms on the surface of the head a black iridescent pellicle, which is sulphuret of copper. The sulphur is held in solution in the onion juice by an essen- * Annales de Chimie, vel. LXV, p- 161. Abridged by Mr, Laugier from the original paper read.to the National Institute, a tia = onion smell. » 4. Alcohol takes up from it sulphur and oil, ANALYSIS OF ONIONS, 29] tial oil, which exists in it with a small qu antity of acetous acid, The part of the juice left in the retort deposited a fawn Examination of the jun -e left after cistilla- Py this sediment alcohol separated oi] and satphur. What was tion. not acted upon by the alcoho! yielded by distillation a coloured matter, having a strong smell of onions. From black, fetid oil, and carbonate of ammonia, which indicate ‘the presence of a vegeto-animal matter, in the coagulum of the onion juice. : The fluid from which the preceding sediment was sepa- rated had a deep brown red colour and a saccharine taste. With acetate of lead it gave a yellow precipitate. - This precipitate, heated before the blowpipe, grew black, emit- ted a smell of suiphurous acid, aud left a globule of phos- phate of lead. The solution of the residuuin in sulphuric acid diluted in water, heated, aud filtered, yielded two pre- cipitates of phosphate of lime on the successive addition of ammonia and lime water. Hence the authors conciude, that the precipitate formed by acetate of lead in distilled onion juice is composed of oxide of lead, phosphoric acid, sulphur, and a vegeto-anim«l matter. Messrs. Fourcroy and Vauquelin, having employed fer- Onion juice mentation as a good mean of vegetable analysis on several C*@™mned by 5 ‘ means of fer- occasions with success, tried it with onion juice. Exposed mentation, to a temperature of 15° or 20° [59° or 68° F.] in a suitable ‘apparatus, this juice emitted no gas; but it acquired in succession a tint of rose colour and of yellow, and a fawn coloured sediment was deposited. The vessels being un- luted, they were surprised to find, that the juice was con- - verted into vinegar, but that it retained the onion smell strong as before fermentation. This proves, that the vola- tile or essential oil had undergone no alteration. They afterward found, that, if the alcoholic fermentation did not take place, it usust be ascribed to the absence of a suitable ferment. The sediment formed during the acetous fermentation of Examination the juice appeared to elvidertel particular attention. This Pi a acer ormec uring substance has the following properties. a. It is in a state jhe a-oripen. ‘of minute division, forms a ‘aheoth paste, _ and has a strong tion of the onion juice, Ug us Examination of the vinegar of onien juices and the crys- tallizable mat- ter it holds in solution. Properties of the crystals. ANALYSIS OF ONIONS. as is easy to judge by the action of oximuriatic acid, which -renders the alcohol turbid, and communicates to it the pro= perty of forming a copious precipitate with nitrate of ba- rytes. c. After being treated with alcohol the sediment has Jess smell: it scintillates on “burning coals, shrivels, and then swells up, emitting the fetid smell-of animal sab- stances. d, Mixed with a solution of sugar, no’ movement was produced, and no alcohol was formed: whence we may conclude, that this substance is not of the nature of yeast, and not calculated to excite alcoholic fermentation. The vinegar formed by ouion juice kad a yellowish coe lour, a very strong smell of onions, and an acid taste, but yet saccharine*. It marked 6° ou the areometer for acids: buat this density was owing to a peculiar substance, which gives it the property of crystallizing when it is sufficiently concentrated. : This substance, which particularly excited the attention of Messrs. Fourcroy and Vauquelin, is neither an acid nor a nentral salt. It presents i.elf iu the form of fine, white, acicular crystals, disposed in diverging rays: it has a sac- charine and at the same time acid taste: it is mixed with a gummy matter, and also with citric acid. Hot alcohol dis- solves both the crystalline substance and the acid accom- panying it, leaving the gummy matter untouched. As the alcoholic solution cools, white needly crystals separate, shining, and arranged in stars. aw These crystals have the following properties. 4. They are of a snowy whiteness, and of a mild, saccharme taste. 6. They are equally soluble in water and in alcohol, c. They burn like common sugar. d. Their solution does not ferment with yeast. e. Nitric acid converts them into the oxalic. They afford no mucous acid, unless when they contain mucilage. Our authors satisfied themselves on this occasidp, that manna, with which they compared them, is wholly converted into oxalic acid, and does not yield an atom of mucous acid, on bejng treated with the nitric acid, if. care be taken to separate all the mucilage that accompa- ® Pickled onions, when long kept, perhaps two or three years, ac- quire a saccharine taste, so as at Jength to lose’ almost all their acidity. C. nies es se ANALYSIS, OF ONIONS. 893 nies it. From these experiments they infer, that the crys- This substance | : is manna. talline matter of onion juice is nothing but manna. It remained now to determine, whether the manna were formed by the ready formed in the juice, or developed by fermentation. i marincnaniet To solve this question, they treated onion juice concen- trated by evaporation in. several ways, and obtained only fermentable sugar, instead of the manna which the fer- mented juice had furnished. It appears then, that the manna obtained from onion juice is the product of fermen- fation, and this opinion is the more probable, as a scru- pulous examination of the fermented juice exhibited to them all the principles it contained before, except sugar*. From the preceding experiments Messrs. Fourcrey and Vaugquelin conclude, that sugar, either when its solution is too dilute, or when it contains a different ferment from yeast, constantly undergoes a kind of alteration by acetitication, which divides it into two new compounds, unequal in quantity, and differing in the proportion of their principles : one vinegar, which contains fewer radicals than sugar; the other mauna, which contains more radicals than sugar. In fact, all the chemical knowledge we have of these three substances confirms this result. , Perhaps, add the authors, there is no improbability in er phi supposing, that, in the trees which furnish manna, this sub- pa. stance is formed in their saccharine juice by the acetous fermentation of sugar, assisted by the glutinous matter that exists in all vegetables. [tis natural to suppose, that the saccharine juice of the ash and the birch, once escaped from its vessels, runs into the acetous fermentation ; and that the results are manna and vinegar, the latter of which after- ward evaporates. This no doubt is the reason, why new manna is acid, and smells of vinegar. This opinion may be confirmed by examining the kind of sap or liquor, that flows from trees apt to furnish manna, when the stem is . tapped. The examination, that Moe Fourcroy and Vauquelin Examination made of manna, convinced them, that beside the erystalli- fem: -zable matter analogous to what they obtained from the fer- * The fact mentioned in the preceding note tends to corfirm this. C, ‘ mented ‘ 294. ANALYSIS OF ONIONS. mented ouion juice, this substance contains a small quan- tity of fermentable sugar, which was observed by Proust and Thenard ; also a small portion of yellow matter of a nauseous smell and taste, which fermentation does not de- stroy, anid to which they think its purgative quality is to be ascribed ; and lastly a little macilage, which alone is con- verted into mucous acid when manna is treated with nitric acid. Melon-juice in ike manner affords them manna, which they could not discover previous to fermentation. Spifituous fer. Pyesirous of knowing whether onion-juice, as a seccharine mentation of “|. 3°) \ ¥ a Ens . onion juice. lquor, be capable of affording alcohol on the addition of a suitable ferment, our authors mixed 244 er. [3707 gers. | of this juice, reduced to the consistence of an extract, with 2 lit. [2 wine quarts| of water, and 30 gr. [463 grs] of beer yeast of the consistence of paste. ‘The mixture, exposed to a temperature of 16° or 20° [61° to 68° F.], exhibited. all the phenomena observed duriny alcobolic fermentation. Car- : eo) ‘ bonic acid was evolved ; and the distillation of the ferment- ed liquor yielded 134 gr. [2069 grs] of brandy at 22°, equi- valent to 73 gr. [1127 grs] of alcohol at 40°. ‘This quantity of alcohol, according to Lavoisier, requires for its produc- tion 114 gr. [1760 gers] of sugar. {+ neral results “F yom the experiments above relatcd it follows, that the of the analysis. : > d ike : of the onion, Oblon Is composed of, 1, a white, acrid, volatile, and odorous | i oil: 2, sulphur combined with oil, which occasions its fetid smell: 3, a large quantity of uncrystallizable sngar: 4, a great deal of mucilage analogous to gum arabic: 5, a vegeto-animal matter coagulable by heat and analogous to | - gluten; 6, phosphoric acid, partly free, partly combined | with lime; and acetic acid;: 7,-a small quantity of citrate of : lime, which bad never before been met with in vegetables: 8, a pareuchymatous on very tender fibrous ‘substance re- : taining vegeto-animal matter. Sources of its It is to the combination of the oil of the onion, the sul- ; properties, phur, the saccharine substance,-and the mucilage, that we 4 | ‘ must ascribe the emulsion or milk, that flows from the slices of this bulbous root, its acrimony, its property of irri- Acrimonv of _ tating the eyes, exciting tears, blackening silver, &c. Most plants resides acrid plants, as. the eupborbias, chelidonias, arums, helle- in an oil, or re- een ae ef : | oe see sin, and best bores, owe their injurious qualties to oily and resinous sub- . - stances : FOSSIL BONES IN CAVERNS IN GERMANY. £95 stances.: and the authors recommend the oximuriatic acid destroyed by as the most certain antidote, to destroy the pernicious effects ike _ of this acrid principle. The presence of free phosphoric acid iu plants is an in- Free phospho- teresting fact, but how is it produced there? Does it pass Fae ues directly from the earth into plants? or does it come from to plauts: phosphorus absorbed by the plant from the soil? Of these two questions the authors have sought the solution; and ‘various arguments, supported by accurate observation, have led them to think, that the phosphorus existing in the ani- ‘mal matters employed to promote vegetation passes in combination with fats and oils into the plants, where it combines with oxigen, and produces the phosphoric acid we meet with. eh es } Messrs. Fourcroy and Vauquelin terminate their paper by Analyses of very judicious reflections on the advantages, that may be prin ada derived from analyses of the plants that are most common tageous. and most in use. The numerous and interesting facts con- Some caleuli tained in’ their paper, and the cousequences deduced fram Sansa them, among which we must not omit the possibility of the juice. solution of earthy phosphoric calculi by the juice of onions, leave no doubt of the benefit that may accrue from re- searches of this kind, in promoting vegetable chemistry and the knowledge of vegetables in general. Vill. . Abridgment of a Paper on the Species of Carnivorous Ani- mals, the Bones of which are found mixcd with those of Bears in Caverns in Germany and Hungary. By Mr. Cuvier *. 45 ¥. On a separate paper on the fossil’ hyena, I have al- Bones of the! * ready mentioned; that bones of this animal were found in a oe the Baumannshoehle, and in a cavern at Gaylenreuth. Out the bear. of a quantity of bones from the latter, among which those of bears were most numerous, I procured a jawbone of a * Journal de Physique, vol, LXV, p 282, hyena, 296 FOSSEL BONES IN CAVERNS IN GERMANY. hyena, more complete than those 1 had before represented, but exhibiting precisely the same characters. The whole of the lower edye aud the condyloid process are very per- fect; and the four jaw teeth are seen, but a little broken. The anterior extremity and coronoid apophysis only. are wanting. . The four jaw teeth occupy the length of 0-092 m. [3-6 in- ~ » ches} uearly the same space as in the piece from Fou- vent, a place in Franche-Comté, where fossil bones of the hyena are found, Another fragment from the same place is part of the jaw bone of an hyena, which must have been larger than the great hyena of the Levant in the proportion of 3 to 2. Lastly Mr. Blumeubach sent me a drawing of the fourth or principal upper grinding tooth of an hyena found in the same place. Bones of an 2. A very large animal of the genus felis. has also left sy numerous remains in these caverns. Proofs of this are found * . for those of Hungary in Vollguard’s paper in the Ephem. Nat. Cur., an. iv, dec, 1, obs. 170, p. 227. [tis an ungui- cular phalanx, easily known by its great vertical height, little length, and difierent projections. Leibnitz in his Protogea has represented part of a fossil skull of an auimal of this order found in the cavern of mentioned by Schartzfels. Soemmering has givea a more accurate deli- Soemmerings yeation of the same specimen, which is at present in the museum at Goettingen. He asserts, that this cranium per- fectly resembles that of a middle sized lion, and differs from that of the bear of the caverns in thirty-six particulars, which he points out: but most of these particulars are com- mou to all the genus felis, and not peculiar to the lion. Esper, Esper has had engraved several teeth found in the cavern of Gaylenreuth, which closely resemble those of an animal of the felis genus, if we could depend on the accuracy of the engraving: but the differences between some of these teeth and those of the hyena depends on such slight yaria- tions, as might have escaped a common draughtsman. and Rosen- Mr.Rosenmueller promises soon to publish a work, which mieller will contain a description of the bones of an unknown animal ; of FOSSIL BONES IN CAVERNS IN GERMANY. 297 ef the lion kind, and he adds, that * these bones are not ‘precisely similar to those of the present lon.” ‘In the mean time he gives us, without being aware of it, three bones of this genus, which he has suffered to slip iu _ “among those of the bear: namely the semilunar scaphoid, the cuboid of the hit.d foot, and the first cuneiform. But if these figures be of the natural size, the animal must have been of prodigious dimensions, whichthe other bones that { have examined do not indicate. Indeed I have myself some new pieces to produce both from Gaylenreuth and other places. First single teeth. A second and third upper grinder of a felis : both from Gaylen- ‘ reuth. Another from the cavern of Altenstein; with the drawing of which I was furnished by the celebrated Blu- menbach. These teeth differ completely from those of the hyena. . ‘LT have likewise half a lower jaw from the collection of Mr. Hadrian Camper. It is that of a felis, . The posterior tooth bilobated and without a heel, thé vacuity before the alveolus of the last but one, the direction of the lower edge, and the situation of the maxillary foramina, leave no room to doubt of it. But when the question is, to what species of felis does Probably be- , this half jaw come the nearest? the answer is not so easy. eb ante J will venture to say, that it is impossible without the nu- mérous means of comparison, which I was so fortunate as to have in my power. Now these means have demonstrated to me, as they will to any one who shall employ them, that this bone belonged neither to a lion, nor honness, nor tiger ; ‘still less to a leopard, or the little panther of the keepers of wild beasts: but that, if we must refer it toa living species, it can only be to the jaguar, or great spotted panther of South Ameriea, which it most resembles, particularly in the _ eurve of its lower edge. The most aceurate ideas we have hitherto of the different Jarge animals of the genus felis wiil perhaps occasion a. doubt of this: but the characters of these animals and their osteology will be the subject of a separate dissertation, that will remove all the difficulties, 3. The 298 3 FOSSIL BONES IN CAVERNS IN GERMANY... Bones of an 3. The bones of an animal of the wolf or dog kind are animal of the : : oo es gl : genus canis, the first I have found fossil, that are no way distinguish- able from those of animals mow inhabiting the surface of the same country: but then it isin a genus, where the dis- tinction of species by separate bones alone is almost im- possible. ; oe, eee Daubenton has already observed how difficult it is to dis- not easily dis- tinguish the skeleton of a wolf from that of a mastiff, or twguishable. shenherd’s dog of the same size. More interested than he in finding out their characteristics, | have studied them longer, carefully comparing the heads of several individuals of these breeds of dogs with those of several wolves. All that I have been able to remark is, that wolves have the triangular part of the forehead behind the orbits a little narrower and flatter, the sagitto-occipital mdge longer and more elevated, and the teeth, particularly the canine, larger in proportion. But these diiferences are so slight, that there are frequently. much greater between individuals of the same species; and we can seareely avoid thinking with Daubenton, that the dog and the wolf are the same speecies. These noticed The existence of wolf’s bones in the cavern of Gaylen- hy Eapen reuth was announced by Esper in his first work. He gives a portion of the upper jaw, pl. X, fig. a, and three camine teeth, pl. V, fig. 3.and 4, pl. XII, fig. 1. He adds in his second paper, that wolves skulls of the common size haye occurred almost as frequently as those of bears, mixed with ; those of dogs of the same size, and with others smaller. Rosenmueller, Mr. Rosenmueller too observes, that bones of the wolf kind occur at Gaylenreuth im the same state as those of ihe bear, and that they were deposited there at the same period. and Fischer, Mr. Fischer has sent me the drawing of one of these wolf’s heads taken from Gaylenreuth, and preserved in the collection at Darmstadt. It is more hkely the head of a wolf than of a dog by the elevation of the sagitto-occipital ridge: but if we may trust to the drawing, the face is not so long in proportion to the skull asin the common wolf, and the muzzle not so slender, to speak absolutely. > ~ J would : x FOSSIL BONES IN CAVERNS IN GERMANY. 299 IT would recommend therefore to those, who have at their A comparison command any of these fossil skulls of wolves, to make a 0! the skulls . it oe recommended. comparative examination of them attentively. With aceu- : _rate measurements they might perhaps iind some constant specific character. I have before me only lower jaws. Our museum possesses four, all from Gaylenreuth. IT have a fifth from the same place, that was in Mr. Camper's collec- tion. All these pieces so nearly resemble the analogous bones in wolves and great dogs, that the eye can scarcely perceive any difference, even individually. The ascending branch how- ever resembles the dog more than the wolf, because it is smaller in proportion, and the condyloid process is larger. The groove for the insertion of the masseter muscle is alse narrower and deeper: but I repeat, these characteristics are so slight, that I cannot venture to offer them as distinguish- ‘ing, if the analogy of other fossil bones did not authorize us to believe, that there were specific differences with re- spect to these also. However, if these differences be not sufficiently proved, the identity of the species is not by this resemblance of some ‘ parts. The various species of the genus canis, the different foxes, &c., resemble one another so much in shape and size, that it is very possible some of their bones may not be dis- tinguishable. ; ,It is proper to observe here, that these bones, whatever they are, are in the same state as those of the bear, felis, and ~ hyena; their colour, consistence, and covering are the same. Every thing indicates, that they date from the same period, and were buried together. _ I have taken myself from a block of tufa filled with bones, a tooth, and a metacarpal bone of the thumb. The latter resembles in all respects that of a wolf or a large dog. This species of wolf is found, as well as that of the hye- Found with na, with the bones of elephants. Mr. Jaeger has sent me Py. the drawing of his most perfect lower jaw found at Cant- ‘stadt, and Mr. Camper that of a tooth of the same kind found at Romagnano, in the place where the elephants bones described by Fortis are found. Mr, Esper says too, that he has «i SOU Bones of an auimal resem bling the tox. Very abun- dant. Enumeration of them, FOSSTL BONES IN CAVERNS IN GERMANY. has some of these wolf’s heads from Kahldorf, in the county of Michstaedt, taken from the quarry where the hyena’s head decribed by Colliai was found, which I have mentioned elsewhere. ' 4. We have also the bones of an animal very like the fox, if it be not the fox itself, at Gaylenreuth. Mr. Ros- enmueller thinks, that these, with the humau bones, and those of the sheep and badger, are more recent than those of the bear, as they are in better preservation. It is possi- ble, that there may be such, put to those | am going to mention this does not apply. They were embedded in the same tufa as the bones of the bear and hyena, from which } extracted them myself; and their composition is not less altered. If they be whiter, it is perhaps because, being smaller, the causes capable of depriving them of their ani- mal matter acted upon them with more force. > They must be very common there, for T took all those of which [ am speaking from a block a few inches in diameter, composed in great part of bones of the bear aud hyena: but they who have searched these caverns have been struck only with the large bones, and bave neglected the smaller, which are neither less curious, nor of less importance to- ward the solution of the grand problem of fossil bones. My foxes bones consist of the following: 1, an outer in- cisive tooth: 2, a canine tooth; both of the lower jaw: 3, an ungular phalanx: 4, an lutermediate phalanx: 5, a first phalanx: 6, a piialanx of the imperfect toe of the hind foot : 7, a first metatarsal bene: 8, a cuneiform bone of the car- pus: 9, a first cuneiform of the tarsus: 10, a second cunel- form_of the tarsus: 11, a vertebra of the middle of the tail: 12, several sesamoid bones. To this species Lalso refer the canine tooth represented by Esper, Pl. X, fig. e. J i nm Compared with those of the common fox. All these bones, compared with the analogous ones in the skeleton of a full grown fox, appearcd rather larger. That of the metacarpus in particular was a little longer, without being larger: but these differences were not snfherent to establish a difference of species, On the other hand the differeut foxes, as the corsac, the isatis, or Jackal, the Cape fox, c. mesomedas, and the two American foxes, c. Virginia- nUS, ON a FOSSIL BONES IN CAVERNS IN GERMANY. 501 nus, and c. cinereo-argenteus, resemble each other too much in size, for us to suppose that these parts of the skeleton, which in general are not very characteristic, shoald exhibit greater differences than those observed in the bones of the’ fossil fox. ’ 1 would recommend it therefore to persons, who live near Farther exa- these caverus, to procure other bones of this species, and ™Ination nex particularly skulls, that they may resume the comparison, wee As far as 1 can judge from an impertect skeletun of a jackal, which [ have examined, I should not be surprised to learn, that they resemble the bouves of ihis animal more than those of our common tox. -. The same block, that farnished me with the fox’s bones pones of a I have just described, supplied me with some of a much species of smaller carnivorous auitual of the weasel genus, and resem- a big the European poiecat, or that ef the Cape. These consist of 1, a portion of the pelvis including the pubis aud ischium: 2, the two outer metatarsal bones: 3, a phalanx of the second row: 4, the last but one of the dorsal verte- bra: 5, two caudal vertebre. These are certainly bones of a weasel: and of all the Most resemble : ._ »those of the skeletons of this genus I have had an opportunity of examin- Envopenh or ing, there are only the polecats of Europe and of the Cape Cape polecat, of good Hope, to which I can refer them. The martin and common weaset have the metatarsal bones in particular incomparably larger. In the zorilla and polecat they are exactly similar to the fossil specimens. The dorsal vertebra is neither so long nor so large as in the polecat: but it resembles that of the zorilla; and this resemblance struck me particularly at first, as the bones of the hyena of the caverns also greatly resemble those of the spotted hyena, which is equally an inhabitant of the Cape. But the fragment of the pelvis directed me again to the polecat of Europe, whieh it resembles more than it does the zorilla. Thus 1 could not venture to lay down the hypo- thesis, which at first appeared.so seducing, that we must search in the neighbourhood of the Cape for the animals most resembling those of our caverns. _ It is extremely desirable, that more of these small bones should be collected, and compared also with those of the mustela 302 Paints found in a evlour shop av Pompeii. ‘Ferra verte; "Yellow ochre. Spanish: brown. All these ant- mals found in hot climates. COLOURS FOUND AT POMPEII. amustela Sarmatica, or polecat of Poland, of the m. Siberiea, or yellow martin of Siberia, and of the Siberian polecat. I have never yet seen the skeletons of these three spe- eles. *. IX. Account of some Colours for Painting, found at Pompeii: by Mr. CuarraL. Communicated to the First Class of the Institute, March the 6th, 1809 T- leer majesty the empress and queen has done me the honour, to put into my hands seven specimens of paints, - found in a colour-shop at Pompeii. Of these one has nudergone no preparation. It is a green- ish and saponaceous clay, such as nature affords in various parts of the globe, and analogous to what is known by the name of ¢erra di Verona, or terra verte. -The second is a fine yellow ochre, which bas peer freed by washing, as is done in the present day, from all the matter injurious to its beauty or: pureness. As this sub- stance 1s reddened. by calcination with a very moderate heat, it affords.a fresh proof, that the ashes, by which Pompei was overwhelmed, retained but a very shght warmth. “No. 3 is a brown red, of the same nature as that at pre- sent in our shops, which is employed ior the coarse reddish coat applied to casks in seaports, and to the doors and win- * One of the things that must appear at first sight the most astonish- ing in the collection of the fossil bones, with which these caverns are filled, is to find there bones of animals, which we should suppose could not live in the same climate: but itis possible, that all these animals may have existed in the same country. The animals of the genus felis, whether lions or tigers, indicate, that the country at that time must have enjoyed a pretty warm climate; and we know from unquestionable testi- mony, that the wolf, jackal, polecat, and bear, are all found in Africa lkewise. J. C. Delametherie. + Annales de Chimie, vol. LXX, p, 22, : dows COLOURS FOUND AT POMPEII. 303 dows of some houses. It is produced by the calcination of the yellow ochre just mentioned. No. 4 is a pumice stone, very light, and very white. It is Pumice stone. of a fine and close grain. The other three are compound colours, which I have been obliged to analyse, in order to. know their constituent principles. The first of these, No.5, is a fine, deep, and mellow A blue com- blue. It isin small’ pieces of similar form. The outside P04 of each piece is a paler blue than the inside, the colour of which is more bright and lively than that of the finest ver- diter. Mauriatic, nitric, and sulphurie acids, produce a slight Treated with effervescence with this colour. They appear to brighten **4% it, even with long boiling. Oximuriatic acid has no action on it. It differs therefore from ultramarine, which is de- stroyed by these four acids, as Clement and Desormes ob- served, Ammonia has no action on it. ammonia, Exposed to the flame of the blowpipe it grows blackish, and the blow. and the continued action of the flame converts it intd a PV¢- reddish brown frit. With borax it fuses before the blow- pipe into a greenish blue glass. Treated with potash on a stand of platina it produces a greenish frit, which after- ward becomes brown, and at length assumes the metallic colour of copper. This frit is partly soluble in water. Mu- riatic acid poured into this solution produces a copious flocculent precipitate; and the liquor decanted from this precipitate yields another in considerable quantity with oxa- la‘e of ammonia. Nitric acid dissolves with effervescence the residuum, which the alkali could not dissolve, and the solution is green. Ammonia produces in this solution a precipitate, which it redissolves when added in excess, and then the so- lution becomes blue. ) This colour then appears to be composed of oxide of cop- Its composi- per, lime, and aluinine. It approaches to verditer in the pars nature of its principles, but difers from it in its chemical properties. It appears to be the result not of a precipita- tion, 304 Of very an- etent use, Somewhat znalogous to blue yverditer, A Tight blue, similar to the preceding. Rose eolour. Action of the blowpipe on it, and of acids.” €ontains no metal, COLOURS FOUND AT POMPEII. tion, but of a commencement of vitrification, or rather to be a true frit. The process by means of which the ancients obtained this colour appears to be lost to us. - All we can learn, -on consulting the anyals off the arts, is, that the use of this colour dates from ayes long prior to the destruction of Pom- pei. Mr. Descotils observed a lively, bright, and vitreous blue colour, in some hieroglyphic patutipgs in Eeypt ; and be satisfied himself, that this colour was prepared from copper. Considering the nature of the constituent principles of this colour, we cap compare it only with the verditer of the moderns; but with regard to its use in the arts we may set aguinst it to advantage our ultramarine aad smalt, partico-, larly since Mr. Thenard has made known a preparation of the latter, which admits of being used with oil. But ver- diter has neither the brightness nor pernanenes of the ancient colour; aud both ultramarine and smalt are more costly than a composition, the three ingredieuts. of which are socheap. It would therefore be worth whiie, to endea- vour to discover the process for manufacturing this blue colour. No. G is a light blue sand, mixed with a few whitish par- ticles. Analysis shows in it the same principles as in the preceding colour; and it may be considered as a composi- tion of the same nature, in which the lime and alumine are in larger proportion. ; IT have only to examine No. 7. This 1s a fine rose colour, soft to the touch, reducible between the fingers to au im- palpable powder, and giving the skin the colour of a pleas- ing bloom. "This colour, exposed to the blowpipe, first blackens, and afterward becomes white, It emits ne perceptible smell of awmonia, Muriatic acid dissolves it with slight effervescence. Pisin this solution aramonia throws down a flocculent precipitate, which is completety redissolved by potash. Neither infusion of pails nor hidrosulphuret of ainmonia nidicates the presence of any metal in it. This COLOURS FOUND AT POMPEII. 805 This rose colour may be considered asa true lake, in A !ake which the colouring principle is mixed with alumine. Its properties, its tint, and the nature of its colouring princi- pile, give it an almost perfect similarity to the madder lake, probably from which I have mentioned in my Treatise on Dyeing Cotton. ™2dder- The preservation of this lake for nineteen centuries without any perceptible alteration is a phenomenon, that must asto- nish the chemist. Such is the nature of the seven colours, which have been Used as paints put into my hands by her majesty the empress. They ap- pear to have been absolutely designed for painting: yet, if we examine the glaze or coating of the Roman pottery, and pevhaps vast quantities of fragments of which are found in all {" Pottery: places, ‘where their armies successively established thems selves, we shall readily be of opinion, that most of these earths may have been employed, to form the coating of this earthenware. In fact, most of this pottery is covered with a red coat, Roman earthe which is in no degree vitreous, and may have been given “"*"% by the yellow ochre, or the brown red, reduced by tritura- tion to a fine paste, incorporated with some mucilaginous, gummy, or oily substance, and laid on witha pencil. Mr. @ Arcet, who has examined the Roman pottery with great skill, has a vase, the substance of which is of a dull red, and the surface of which was coated with something of this coated, kind. The place where the workman left off coating the vessel may be seen; and on the bottom, which is not coated, may be seen red strokes, made by the workman to try his colour or his pencil. ; It is not uncommon to find other vessels, the substance of which is of a differest colour from the red coating, that co- vers the surface. Pevhaps the Romans even employed saline fluxes, to fa- and perhaps - evlitate the baking of the outer coat of their pottery. ‘eat fluxes Mi. d’Arcet has perfectly imitated the white covering of White of the. the Etruscan vases, by using a clay that bakes white, with Etruscan vases, which he mixed a twentieth part of borax. oft appears, that in the first century of our era the Romans Metallic fluxes were unacquainted with the use ef metallic fluxes, to fix eee and vitrify,the coating of pottery. At least the analy.is of Wo. XX1V—Dec. 1909. x the 306 Black glaze. Their pottery baked with a Jow heat. Far inferior to us in this ma- nufacture. COLOURS FOUND AT POMPETIT. the coatings of Etruscan vases, and red, white, and: browa earthenware, afforded no indication of metal either to Mr. d’Arcet or me. It was not till a later period, that sulphu- rets of copper and lead, and oxides of lead, were employed for this purpose. Occasion ly indeed we find these metal- lic coatings on some vases dug up; but I conceive them to have been fabricated subsequently. to the time when the Romans possessed Gaul; for all those I have examined, the origin of which evidently dates from the former peried, give no trace of lead or copper when analysed... Sometimes the black colour alone exhibits marks of vitri- fication. I have even seen several specimens of ancient. pottery, in which this character is indisputable; and I-have always thought, that a vitreous lava formed the base of these coatings, the fusion of which, naturally easy, was farther promoted by a mixture of saline fluxes. I published my work on this subject five and twenty years ago; Mr. Four- croy applied it in a very happy manner in his manufactory at Paris; and Mr. d’Arcet has confirmed my opinions by his own experience. The Roman pottery however, eatin the Etruscan vases, was baked with a very slight heat compared with that we vow employ. It may be estimated at-7° or 8° of Wedg- wood’s pyrometer; and at this degree, as Mr. d’Arcet has shown, we cannot employ the exides of lead, which then penetrate into the substance, and leave the colour without any gloss on the surface. .No- doubt we are far superior to the ancients in sia art of pottery. The numerous series of metallic oxides, succes- sively discovered and applied, has furnished us with the means of enriching our pottery with a variety of colours equally brilliant and substantial; at the same time that a better chosen mixture of earths: has enabled us, to obtain the greatest degree of hardness with almost absolute infusi« bility: but the Etruscan vases will always be prized for the beauty, elegance, and regularity of their forms; and I thought, that whatever relates to the history of the arts among the Roman people would be acceptable to those, who mterest themselves in the promotion of manufactures. : ait : X. F. INTRODUCTION OF AIR INTO THE BLOOD. 807 xX, Remarks on the Introduction of Air into the Blood through the Lungs, in Answer to Mr. Acron. Jaa Letter from-a@ Correspondent. may fe To Mr. NICHOLSON. SIR, Your correspondent, Mr. Acton, appears rather hastily vindication of te accuse Mr. Ellis of ‘* a most singular perversion of one Mr. Ellis. of Mr. Bichat’s experiments” in the last number of your Journal. It seems to be the object of Mr. E., in the first paragraph alluded to, to show, that when air is forced into the blood, through the lungs, it quickly destroys life; and in support of this position he quotes facts from the writings of Haller, Girtanner, and Bichat, which abundantly estab- lish that point. According to Mr. Acton however, Bichat is said to consider these experiments, as ‘ affording a proof * of the passage of the air into the blood, through the © lungs, in addition to that of healthy respiration.” Does ‘Mr. Ellis deny this? On the contrary, has he not brought forward these experiments expressly to prove it, with the additional circumstance, that it speedily occasions death ? But, by “ a most singular perversion” of Mr. Ellis’s meaning, Mr. A. applies these experiments to another part of that author’s-work, where he evidently appears to be speaking only of natural respiration, and makes no allusion whatever to the forcible injection of air into the blood, which fact he had before admitted for a very different pur- pose. In the language of Mr. A. I dare not say this was in- tended; but it is ‘* wonderful,” if the application be just, that he did not rather undertake to show, that Mr. E., in the two passages quoted, had contradicted himself, than that he had perverted the experiments of Mr. Bichat. Iam, &c. d. i ; —— ¥ P. S. With respect to the great question, whether a por- cn ee re tion of the oxigen, consumed in respiration, be absorbd by ji0c4 in pes ; xX 2 the ation. r 308 Height of the thermsmete’ Situation of the snstru. ments. he heat not commuicated quickly enough to the contig vous alr, METEOROLOGICAL JOURNAL. the blood as Mr. Acton supposes, or whether. it be not en- tirely converted into carbonic gas as Mr. Ellis maintains, [ do not presume to veuture a decided opinion: but I must be allowed to say, that, notwithstanding the numerous ex periments of Mr. Acton in behalf of the former opinion, the latter has received no inconsiderable support from the re- cent experimeuts of Dalton and Thompson*, and Messrs. Allen and Pepyst. XI. ; Letter from Mr. Rosert Bancxs concerning the Meteoro- logical Journal. z To Mr. NICHOLSON, SIR, Is consequence of the letter of your anonymous corre= spondent, which yeu had the goodness to show me agreea- bly to his permission, I bave been endeavouring to discover the cause of my statement of the height of the thermometer not agreeing precisely with those of others, particularly on the hottest day of Juiy 1808. The account of the situation of the instruments has been given i your QIst volume, p. 79. I first placed with my thermometers two or three by other makers, the best I could procure: but could find no difference worth notice. When standing pear them indeed a little while with a friend, to examine and compare them attentively, we repeatedly found, that the thermometer nearest to which we stood always rose a little the highest; no doubt owing to the heat comniu- nicated from our bodies. From the circumstance however, that the thermometer ap ypeared to give generally. too low a temperature for the highest, and too high for the lowest, when they deviated ; from. the Journal of the Royal Society; I was induced to suppose, that the air contiguous to them might be too slow ¢ a ; 4 oi! Lig ioe 4 * Syst.’ Chem. vol.V, Sd ndit.. + Phil. Trans, 1808, ~ in Fs SCIENTIFIC NEWS. 309 in acquiring the general temperature of the atmosphere; and conceived this might be owing te their being placed in a yard of rather too confined dimensions. 1 therefore placed other thermometers, by way of comparison, at the height of 17 feet from the ground, in a situation where they were equally protected from reflected heat, but were of course in a less confined part of the atmosphere. My conjecture was in some degree veriiied ; for, on a careful examination for several weeks, I have found the thermometers above ap- parently a little more sensible of change; though still the difference between them has never been great. Accordingly 1 have since registered from the thermo- Thermometers meters in this situation; and I am inclined to think, that tical placed few can be found superior to it in the advantage of not being affected by any reflected or adventitious heat or cold. From what I have observed it is probable, as [ noticed at the’ time, that my statement of the heat in July 1808 was.a little below the truth: but if the difficulty of finding a situation totally unaffected by reflected or communicated heat be considered, I am persuaded that much greater errours in excess were made by other, observers, than mine in defect. ; I am, Sir, Your humble servant, R. BANCKS. BC TEN TIES NEWS. Proceedings of the French National Institute. Tue Class of Mathematical and Physical Sciences has French Nati- proposed the following prize question. onal Institute. The first 1 inquiries concerniag sound date very high in an- Investigation tiquity. The proportions of the length of strings produc- of sound. ing different notes are ascribed to Byvhabores: but this branch of science made no remarkable progress before the end of the seventeenth century. Sauveur, a member of the sauyeur. French Academy of Sciences, showed by very ingenious experiments, that the sounding string was divided into seve- rat 310 Taylor. Bernoulli, SCIENTIFIC NEWS. ral waves, separated by nodes, or. points of rest; and he de- termined the absolute number of vibrations that constitute each note, deduced in the first place from delicate and cu- rious experiments, which he compared afterward with the algebraic formule derived from the theory of the centres of oscillation; as appears in the Memoirs of the Academy for 1713. Taylor, in his Methodus Incrementorum, published in 1717*, treated the problem more profoundly, on the hypo- thesis, that the forces acting on the material points of the system are proportional to their distances from a right line drawn from one fixed point to the other, so that these points all arrive at the right line at the same time. Twenty or thirty years after Daniel Bernoulli farther developed the theory of Taylor; but for the general and strict solution of the problem we are indebted to d’Alembert and Euler. These great geometricians first employed the differential equation of the motion of the sonorous chord, which is with D’Alembert & partial diiferences, and of the second order. This equation Euler. _Sonorous tubes, strings, and springs. was first found and summed up by d’Alembert, but Euler was more sensible of its generality. An equation of the same order is applicable to the oscil- lations of air in tubes; and does not change, when from the case of the simple line we proceed to cases of two or three dimensions. In the problems of which we*are speaking the order of the differential equation of the motjon is connected with the manner, in which we consider the effects of elasticity in the body moved. It has been here applied to a chord stretched between two points. If the chord be let loose at one of these points, being perfectly flexible, it is incapable of pro- ducing any acoustic phenomenon. It is otherwise if the chord be a spring properly so called. In this case, confining it if you please to a single fixed point, the spring set to vibrate will produce a perceptible seund, if its oscillations exceed 24 per second: but the dif- ferential equation of this movement will be of the 4th or- der, The first problem may be considered as a particular * Taylor’s paper on the motion of tense stri _ was published in the Phil. Trans. for 1713. a “Sty case SCIENTLFIC NEWS. * $11 case of the second, abstracting the spring: but the converse does not hold. The essential difference between the questions of the Stretched movement, considered in’ each of these points of view, in Pachment. the case of a simple line, leads us immediately to conceive, that we must find differences of the same kind, and in par- ticular a great increase of difficulties, when we introduce _ two dimensions into the calculation. The acoustic pheno- ‘mena exhibited by parchment stretched, as on a drum-head, are referrible to these of the chord; the phenomena of me- tallic plates, to those of the spring. Euler, in his paper de Motu vibratorio Tympanorum, has Drums. considered the parchment as composed of threads crossing each other at right angles. A geometrician of the Institute has publisiied in one of its volumes some researches on this subject, contemplating it in the same point of view. The ditferential equation of the motion, which is partial and of the 2d order, cannot be summed up, at least in finite terms. In his paper de Sono Campanarum Euler attempts to re- getls, duce the vibrations of hard surfaces formed by revolution to those of circular elastic rings, of which he considers them as an assemblage, situate in planes perpendicular to the axis of reyolution, and supposing the effect of the vibration to be a variation of the lengths of their diameters. He here arrives at an equation with partial differences of the 4th or- der, pot summable in finite terms. . Thisis all that geometricians have been able to effect with Hypotheses regard to the problems of sonoreus bodies considered in the eae sat ease of two dimensions; and even introducing simplifica- tions, which, it cannot be denied, alter the natural state of things, so that the results of analysis cannot be applicable. These hypothetical simplifications are particularly inad- missible in respect to vibrating surfaces of metal, or a sub- starice naturally elastic. In the most simple case, that of a plane, it is obvious, that Euler's: hypothesis of the vibration Euler’s not of surfaces of revolution is not applicable. We have not @pplicable. eyen the differential equations of the motion for vibrations of this kind, considering their phenomena as nature pre- sents them ; and to find these equations would be an inter- esting subject of meditation to geometricians, which would’ contribute 312 Chladni. Prize question. Report on Mr. Chiadai’s Theory of Sound. Number of vi- brations in notes. \ SCIENTIFIC NEWS. 4 _ contribute equally to the advancement of natural philoso- phy and mathematics. Happily Mr. Chladni has done om the vibrations of elas- tictic surfaces what Sauveur. did a century ago for the stretched chord. He has discovered, and rendered percep- tible in a very ingenious manuer, by the arrangement dry sand takes on vibrating plates, undulations with points of rest interposed. His majesty the emperor and king, who - has seen the experiments of Mr. Chladni, struck with the influence that the discovery of a strictly accurate theory, capable of explaining all the phenomena rendered sensible by these experiments, would have on the progress of natu- ral philosophy and mathematical science, has desifed the class to make it the subject of a prize, to be proposed to all the learned of Europe.’ The class accordingly aanounces it in these terms. ‘¢To give the mathematical theory of the vibrations of ‘* elastic surfaces, and compare’it with experiments.” The prize will be a gold medal of the value of 3000 f. [ £125], to be awarded at the public meeting on the fifth menday in january, 1812. No work will be received after the 30th of september, 1811. The following is an abstract of the report adopted by the class of matiematical and physical sciences, and that of the fine arts, on the 13th of february and 18th of march, 1809, on Vir. Chladni’s work concerning the theory of seund. | This treatise, published in German in 1802, aud about to be translated into French, contains every thing of impor- tance in his first work, which appeared in 1787, and is en- Jarged by considerable additions. Under the title of acous- tics, it is divided into four parts, which treat, 1, of the nu- merical ratios of the vibrations ef sonorous bodies; 2, of the laws of the phenomena they exhibit; 3, of the laws of the propagation of sound; 4, of the physiological part of a- coustics. > The first contains little but what is already known.’ To determine the absolute number of vibrations in a note how- ever, Mr. Chladni does not employ a chord, but a slip of metal fixed at one extremity, and long enough to allow the oscillations it makes ina given time to be counted. Their number SCIENTIFIC NEWS. 313 number is to that of the vibrations of another slip of metal, taking place at the same time and under the same circum- stances, in the inverse ratio of the squares of their lengths. In this part too Mr. Chladni treats of the temperaments Temperas proposed by different persons. He prefers that adopted by ™°n’- Rameau, which renders the 12 senfitones included in the octave perfectly equal to each ether, by making them an- swer to 12 geometrical uiean terms between the two ex-. treines, In the 2d part we find the author’s discoveries. He first Rods have examines the vibrations of chords and rods, and distinguishes vealed or three sorts, the transverse, longitudinal, and those ue a he ti ion, peodading calls gyratory. The first take place when a chord or rod is diferent notes. struck in a direction perpendicular to its length. Buta rod, that would produce a certain note when thus struck,’ would emit a very different one, if rubbed with a piece of cloth ia the direction of its length. If the rod be of glass, the cloth must be wet; if of any other substance, dry. These vibrations, which he terms longitudinal, he has found subject to the same laws im a solid rod, as the longitudinal vibrations of the air in an organ-pipe; and he fee given a table of these vibrations for ditferenut substances, such as Blass, metal, and wood. “Notes still different from those emitted in the two pre- ceding circumstances are produced, when a rod is rubbed in a direction very oblique to its axis. Mr. Chladni gives the epithet of gyratory to the vibrations resulting from this kind of friction, because he supposes, that the particles of the substance acquire a movement of rotation or oscillation round its longitudiaél axis. He says he has found, that in these vibrations the numerical ratios are the same as those of the longitudinal vibrations, but that the tones of each rod are a fifth higher. Fach series of inquiries abovementioned has been made x periments with rods fixed at each end, merely supported at one or eeagtaen both ends, fixed at one endand supported at the other, and iheesoat wayse Joose at each end. Each of these circumstances oceasious a difference in the results. Mr. Chladui bas likewise exa- mined the"’vibrations of curved rods, forks, and rings. ' Eu- _ Ter applied the last species ef vibrations to the phenomena i ’ of 314 Wibrations of plane & curved elastic Sur- faces, Elastic plates. Examination of these by Paradisi. ire vibrations go through a senies of eLanges. SCIENTIFIC NEWs. . of the sound of belis; but Mr. Chladni has shown. very truly, that his hypotheses do not accord with nature. The last two sections of this part are devoted to the vi- brations of plates and bells, or plane and curved surfaces in general, a subject altogether new in experimental philoso- _ phy; and which, notwithstanding the striking regularity of the phenomena, has resisted the efforts.of the able geome- tricians, who have attempted to treat on it. | ’ Mr. Chladni has aseertained the places, which the tones we may draw from plates by giving them different forms, and by causing them to sound in different methods, occupy in the musical scale. But these inquiries are particularly interesting, when combined with those for determining the portions of each plate that have distinct and coexisting vi- brations, and the remarkable curves that form their perime- ters. For these experiments the plate, covered with fine dry sand, is to be held between the thumb and one finger, the ends of which press on directly opposite points of the two faces, while a bow is drawn over some point of its peri- meter. Sometimes a third finger is applied at different points of one of the faces, to vary the results of the experi- — ments. The point of support is always in one of the curves ef equilibration. . The figure of these curves, and their ar- rangement, depend on the posiiion of the point of support, that of the point to which the bow is applied, and that. of the different sounds we wish to produce by rubbing the bow in different ways on the same point. A change im either of these produces a correspondent change in the curves. While speaking of these curious phenomena, we cannot avoid noticing a paper inserted in the first yolume of the Transactions of the Italian Institute, entitled Inquiries con- cerning the vibrations of elastic plates. The author, Mr. Paradisi, says in a note, that he was led to make his expe- riments by a passage in the Bibliotheque Britannique where Mr. Chladyi’s were described. Having provided an appa- ratus, by means of which he could keep the plates fixed at any point of their surfages without the assistance of the fin- cers, he first perceived, that the curves of equilibration did pot arrive at settled figures, till after a gradual and»continual succession of variable figures; the generation of which, be- ing SCIENTIFIC NEWS. 319 ing examined by him with great attention, led him to new inferences respecting the theory of these curves. * Thus for example, if we take a rectangular parallelogram Examples. of glass 9 inches long and 3 broad, fix it in the line of its longer axis one sixth of its length from the end, and apply the bow to one of the longer sides of the parallelogram at one third of its length; the lines in the sand, when come to _ a state of rest, will divide the surface into eight equal rec- tangles by a right line in the direction of the great axis, and three equidistant right lines parallel to the shorter sides. - But Mr. Paradisi found, that on causing the plate to vibrate by a succession of very little touches with the bow, 8 semi- circles were first obtained, the centres and diameters of which were placed symmetrically on the longer sides of the parallelogram, and the point of application of the bow was one of these centres. These semicircles gradually increase: those on the same side from separate become tangents, and afterward penetrate into each other, leaving between them rectilmear lines perpendicular to the longer sides; and in proportion as these lines increase in length, the ares flatten as they approach the greater axis of the parallelogram, with which they are at length confounded. In other experiments Mr. Paradisi obtained whole initial circles formed on the surface of the plate, and semicircles with their diameters resting both on the longer and shorter sides of the parallelogram. The velocity of the grains of grains of sand placed in the perimeters diminished in pro- portion as the radii increased. Mr. Paradisi applies the term of centre of vibration to the Centres of vi- centre of the circle that forms round the point to which the moot bow is applied, and that of secondary centres to those of the cents. other circles. Supposing afterward, that when the system of curves is arrived at a fixed state, any given element of these curves is directed by the result of several forces, the actions of which emanate from these different centres of vibration, and are functions of their distances from the ele- ament of the curve in question, he arrives at a differential equation between the coordinates of this element, the sum~- mation of which would require the form of the functions, that represent the laws of the actions of the forces, to be known 316 SCIENTIFIC NEWS. known. He promises us farther inquiries on this subject in another paper. ’ We must refer to the memoir itself for his other experi- ments, among which are some interesting ones on changes in the fixed point, and in the point to which the bow is ap- plied, without producing any in the figure or arrangement of the curves. Vibrations of Mr. €hladni concludes his second part with reflections on bells. the vibrations of bells, and of curved surfaces in general, and on the coexistence of vibrations in sonorous bodies. He speaks of the theory and hypothesis of Euler respecting the sound of bells; of Rameau’s system of the fundamental base ; of the musical syste of Tartini, founded on expe- riments, which, according to Mr. Chiadoi, were kuown in Germany long before Tartini made use of them, and which ¥ may be considered as the inverse of Rameau’s; and lastly of the combination, which takes place in certain circun:- stances, of the vibratory with other kinds of motion. Piepdgatiche ct In the third part the author first considers the propaga- sound through tio of sound as effected by the air and different. aeriform different sub- fluids: he then examines the cases where it takes place & /Stances, through the intervention of liquid and solid substances. We here find the experiments, which the author made in concert with Prof. Jacquin of Vienna, on the vibrations of various kinds of gas; and conjectures on the cause of the difference between the observed velocity. of the pro- pagation of sound nical gh air, &c., and that given by theory. y The committee conceive, that the two classes ought to ; bestow distinguished encomiums on the discoveries af Mr. | Chladni ‘respecting the philosophy of sound; and that it is an object of importance, to direct the < “irteritiod andemula- tion of the learned to those physico-mathematical researches, to which his discoveries may give rise. . Signed, de Lacépede, Haiiy, Mehul, Gossec, Gretry, Le Breton, de Prony. . Imperial / SCIENTIFIC NEWS. 317 Imperial Academy at Petersburg. The follawing prize subject is proposed by this academy Imperial Rus- for the year 1810. sian Academy« «To improve the theory of sluices, and thence to deduce Prize question rules for constr ucting these important works in the most ad- fe F800, vantageous manner; so that they may be used with all pes- sible security and speed, be attended with as little expense as may be for their construction and keeping in repair, and incur no waste of the water required for the passage of load- ed vessels, more than is absolutely necessary.” And for 1811. ‘* To give a complete comparative chro- and for 1811. nology,.and, if possible, corrected and veritied, of the By- _ zantine authors, from the foundation of the city of Constan- tinople till its conquest by the Turks.” The prize for each is 100 Holland ducats [£46 5s.], and the answers must be sent before the Ist of July in each year. —senerionions Mr. Peter Alemani, of Milan, has analysed a new spe- Analysis of a cies of urinary calculus. In 100 parts he found pure mag- utinary stone. , nesia 51, ‘Silex 20, phosphate of iron 11-34, carbonate of magnesia 4. ‘The volatile substances and loss amounted to 3°16. [One of these numbers has evidently a deficiency of 10.] . « ‘Dr. G. Melandni, of the same place, is examining the a rtigeial my attificial tannin of Mr. Hatchet, but in another point of nin. view. His researches are on the tannin of different plants and vegetable products. He thinks, that it is not an oxide éf carbon: but an oxide with a binary, or more probably- ternary radical. The nitrogen of the nitric acid must enter \ to its composition ; ; as must the nitrogen of the animal eharcoal, since this succeeds better than vegetable charcoal. fie believes too, that hidrogen enters into it, though in small quantity. On analysing deadly nightshade, atropa belladonna, he 4 narysis of discovered in the leaves a salt never before observed in ve- rated nig hte getables, the oxalate of magnesia, joined with free oxalic™ acid. The other substances in them were oxalate of lime, : murlate $18 SCIENTIFIC NEWS. muriate of potash, a soft green resin, an animal extract, mucilage, and oxigenizable extract. In the berries he Sensible test found as sensible a test of acids and alkalis as the infusion — aud of mallow flowers. By pouring alcohol on the expressed juice ef the ripe berry, the purple fluid will be coagulated by the precipitation of the mucilage. This coagulum is to be well washed with the same alcohol, and the tincture fil- tered off. If this tincture be diluted with water till it has no longer any perceptible colour, it will become green with alkalis and red with acids. The purplish colour of this tincture changes to a yellow in time, but it still retains its property of detecting the smallest portion of acid or alkali mm water. Potassium ob- Mr. Ritter has obtained the metallic product of potash esi var with almost all the metallic substances yet known, when they are employed as the extremity of the negative con- ductor, and always fine and perfect. Arsenic alone pro- duces it of a shining black or blackish colour. He has ob- tained it also by employing charcoal and plumbago as con- _ ductors: but not with the gray crystallized oxide of man- ganese, which is merely deprived of, its oxigen im the pro- Tellurinm dif- cess. When tellurium was placed in potash as the extre- nian eh mity of the negative wire, it did not produce bright metal ether metals. of potash, but a brown dirty substance. Mr. Ritter then took tellurium for a negative wire, and immersed it in pure water in which was likewise the positive wire, and immedi- ately streaks of a brown black were produced, which, sepa-. rating from the tellurium, fell to the bottom of the water, and from the manner in which they were produced, and the place of their origin, they must have been hidruret of tel- lurium. Thus tellurium produced no metal of potash be= cause it absorbs all the hidrogen itself. The button of tellurium, purified afresh, was employed as a positive wire in pure water; and, what must excite more astonishment, it remained brilliant, formed no oxide, and gave out a great deal of gas. Thus of eighteen metals subjected. to Mr. Ritter’s experiments, tellurium is the only one, that pro- duced a hidruret at the negative pole; and the fourth, that with gold, platina, and palladium, gives out gas at the positive pole. Does tellurium then commence a new series of SCIENTIFIC NEWS. 319 of metals, which comport themselves with respect to the hidrogen of water as others toward the oxigen of this fluid? — Dr. Seebeck, of Jena, has obtained indications of an Magnesia and amalgama with magnesia and alumine. n ebes per pe ane . aps metallic, Mr. Trommsdorff has prepared an artificial succinic acid. Artificial suc For this purpose he employs the saccholactic acid of “7c acid. | Scheele, which he introduces into a retort and subjects to dry distillation. The products of this distillation deserve farther inquiry. ~He has likewise examined the sulphuretted alcohol of Sulphurettead Lampadius, and found in it several new properties. As it “ee contains no carbon, he thinks it may be called oleous hidro- contains no guretted sulphuret. It readily dissolves phosphorus, and ¢@tbon. in large quantity ; one part dissolving eight of phosphorus and still remaining liquid. This solution of phosphorus readily takes fire in the open air. In close vessels it may be decomposed by heat. The sulphuretted alcohol first passes over, though not quite free from phosphorus. Fecula.dissolved in boiling water undergoes a remarkable Fecula . : changeable by change, when evaporated over a moderate fire. It becomes },.,;. a semitransparent horny mass perfectly insoluble in hot water. Wetted, and kept five months in a pretty warm place, Mr. Trommsdorff could not find it exhibit any signs of fermentation. Mr. Trommsdorff repeated Mr. Cadet’s experiments on Camphorated water notatest - the solution of camphor in distilled water*. He found of ) S20 ana =I 30°28 50° | O° yl ae Ag, ° 30°28 48°5| 505) 53 | 46 30:26 47 49 1 51 46 30°22 48 SOT Se 40 30-n 48 46°5 © .50 AT 30°10 49 4Ar 5} 52 42 30°20 «| 45°5} 47, |. 49°54 39 30°14 44. ).45.,| AF-S} 40 29°93 44°54 45 | 46. | 40 20°84. 42°5 | e145 oY 29°92 ATS |S Sha 1937 30°06 {42 46 Np IaT AQ: 36°39 Qr heh Ad 4.0 40 30°42 43 46°5| 47°5 | 40 30°29 47 47°3-| 50°5| 43 30°15~ || 4475 | 43 50 1°49 29°91 4a PAA AG) AT 20°74 43°5 | 44 46 36. 29°72 38 4075 | 47°75 | 3+ 29°70, | 30 | 350. | 3954 29 29°71 SEad S40. lay 32 29°48 39 30°5 | 45 30 29°73 34 36 38 30 30°23 BSNS 37°54}. 26 30°43 28°5 34-5 | 37 5 30°28 38 35°5| 41 36 30°16 39 $5°5) 49°5 | 41 30°03 13°5 | 47 49 40 29 39 42 Pc ales Ie: ame 29°78 ~ 40 142 3 | 29°t0° }.4 38 | 13°5 | 32 * At6 P.M. stars visible; at 9, heavy fog; at 11, starlight. + At lly starlight and clear, Cun firetierag, rare at 10 P.M. § Suow in the night, the momming mi ilder. WEATHER. Day. Night. Te ION i | UU se te Fog | Foggy Ditto Heavy fog Ditto Rain Ditto Cloudy Pair Foguy* Cloudy Rain Fair Cleudy Rain Rain Ditto Ditto Ditto Cloudy+ Ditto: Rain Cloudy ores Fair Ditto Cloudy Cloudy Ditto | Ditto Ditto Ditto ©” Ditto Dittopes 2a Ditto Ditto . Fair | Rain Ditto Fair Ditto _ Ditto§ ~ Rain Ditro Snow Ditto Fair Ditto [: Diito Ditto: Ditto Ditto Ditto Ditta - Rain Rain Ditto Cloudy Fair Mitto Ditto Fair A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. SUPPLEMENT TO VOL. XXIV. ARTICLE I. Memoir on the Triple Sulphuret of Lead, Copper, and Antimony, or Endellion. By M.1te Comte DE Bournon, F. R. and L. S. (Concluded from Page 260.) PART II. Observations on Endellion, as being the Result of a triple Combination, and on the different Sulphurets of Copper. ‘Tue Royal Society has printed in the first part of the Ata oie Philosophical Transactions for 1808 a paper*, in which See tata. the constituent principles of endellion, as well as the manner in which they combine, are discussed +. The author * See Journal, vol, xx, p. 332. + Additional note. I mean Mr. Smithson’s paper already men- tioned. The Royal Society having printed a critique on the crys- tallographical part of my first memoir on endellion, however I might feel hurt by the style of that critique, I thought it better not to notice it, than to expose the transactions of that illustrious and respectable body to be made the scene of a dispute, which certainly could not be more misplaced. I therefore presented my new memoir on endellion te the Royal Society, merely as the result of continued and extended You, XXIV.—SuppLEMENT. - observations, 322 Doubts of the existence of higher than binary combinations, Ultimate par- ticles of bodies have a regular figure. Combinations more than binary may exist. SULPHURET OF LEAD, COPPER, AND ANTIMONY, author there professes his doubts of the existence of triple, _ | quadruple, and greater combinations; and his opinion, that all combinations are binary. In consequence he endea- vours to refer to one of the latter the nature of the com. pound, that gives rise to endellion ; considering it as formed by the intimate combination of sulphuret of lead, or galeua, and that kind of copper ore, which the Germans call fahlertz. I cannot conceive on what reasons the author grounds his opinion, that there can be no triple, quadruple, or greater combination. On the contrary the possibility of these combinations seems to me demonstrated by the simple facts, that I have already brought forward in the seeond volume of my mineralogy, p- 390, in order to show, that the molecules of bodies, considered as principles of minerals, possess, as well as the integrant molecules which result from the combination of these, the property of having a regular figure. The act of combination of these molecules, in observations, which had enabled me to make this substance, which is peculiar to England, more thoroughly known, and to render my account of it more complete. The sécond part of my paper was intended to include some re- flections on a fact highly interesting both to the mineralogist and the chemist, which is the possibility or impossibility of the exist- ence of triple, quadruple, and other combinations. inthe mineral kingdom. Mr. Smithson, in one, part of his paper, sought to establish the principle, that all combinations could only be binary, and adduced endelJion in confirmation of his opinion. After having laid down the reasons, that seem to me to preclude all doubt of the possibility of more ‘than binary combinations, it was necessary for me to show the weakness of the argument deduced. from endellion; which could not be made to answer this purpose without giving anarbitrary proportion of the component parts of the ’ two sulphurets, the binary combination of which produced it, or at. least a proportion different from that usually admitted by chemists. I confess, however, that, had I not found occasion to answer the critique included in the same paper, it would not pro- bably have been ia the Philosophical Transactions, that I should have pointed out this obvious errour. However, if the committee of the Royal Society had requested me, to suppress this part of my paper, | should not have hesitated ‘a single moment to ‘comply with its wishes, however interestiug I conceived it to be. 2 7 forming SULPHURET OF LEAD, COPPER, AND ANTIMONY. 3 i~ ww forming the integrant molecule, which is the immediate result of this combination, differs then in. no respect from that, which afterward unites the integrant molecules. Now it is very easy to conceive, and even to adduce a number of instances of the formation of a crystal of any determinate figure (representing the integrant molecule of a compound substance) that shall be composed of the intimate union of three, four, or even more crystals of different forms, which in this case would represent the molecules of the substances that compose it; and which would enter into the composition of the crystal in equal numbers, or, which is more commonly - the case, in unequal numbers. It is indeed to the property, Particles unite which the molecules of minerals have, of uniting intimately eae with each other, so as to produce a new molecule of aa different determinate figure, that I attribute in part the formation of cae those minerals, which are commonly said to be the effect of binations. chemical ‘combination. Every combination of the sub. stances of which a mineral is composed seems to me to re- quire, that the form of the molecules of each shall bear such a relation to those of the rest, that their faces may — respectively coincide, so as to produce collectively a mole- cule, the form of which shall be at once determinate and invariable. It-is this relation between the several component molecules, which in all probability determines their action upon each other, known by the name of ‘attraction of composition ;” or which is at least a principal cause of this. ’ Upon the same:principle we may account for the proportion of the several substances, which must necessarily vary, according to the number of these molecules, the forms of which are different, and the mode in which they arrange “themselves, so as to produce a new molecule, the form of . which shall bedeterminate. When the molecules are whelly dissimilar, and there is no relation whatever between their faces, _it is not possible for them to combine, so as to generate a néw substance properly so called and capable of crystallization. The real .existence of these mere and greater combi- Gypsum the re- nations is farther demonstrated by facts. We know, for stent tetesios: instance, that there exists a substance which differs from gypsum, or the combination of lime with sulphuric acid ana ¥2 water, 3 Objection. Answered. SULPHURET OF LEAD, COPPER, AND ANTIMONY, water, only in not containing of the last of these three constituent principles. Yet this simple privation, by producing a substance of a different form, harder, heavier, and possessing different chemical properties likewise, shows, that water, which combines as a principle with lime and sulphuric acid in the formation of gypsum, is necessary to its formation, and that gypsum is consequently the result of a real triple combination. It may be objected indeed, that in gypsum there exists only a double combination between the molecules of sul- phate of lime on the one hand, and those of water on the other. But, if this were the case, when the water had been expelled from the gypsum by calcination, the sul- phuric acid being left, there should still be an intimate combination between the molecules of the sulphuric acid and those of the lime: and the plaster, which results from this calcination, should exhibit a substance precisely of the same nature as that known by the name of anhydrous gypsum, or bardiglion (as I call it,) whereas in fact there is no similitude whatever. The bardiglion reduced to powder, either before or after calcination, possesses none of the properties of gypsum, and does not absorb any water whatever, so as to combine with it, and thus acquire the solid form. By the great avidity with which calcined gyp- sum seizes on water, the moment it comes into contact with it, we discover that calcination, by taking from each of the integrant molecules of gypsum (composed of those of sulphuric acid, lime, and water) the molecules of water, has changed the integrant molecules of this substance into new molecules, consisting simply of those of lime and acid, but having only an incomplete form: or, if I may be allowed so to express myself, we perceive that this calcina-. tion has carried away a part of each of the integrant molecules of gypsum, and left in each one or more cavities, the sides of which, having a very powerful affinity for the corresponding sides of the molecules of water, seize on them as scon as they have an opportunity of so doing, and fix them again in the places to which they belong. Gypsum is then in fact the result of a triple combination. But SULPHURET OF LEAD, COPPER, AND ANTIMONY. 225 But is it certain, that the integrant molecule of endellion Endellion more is simply the result of a triple combination of the integrant or OIF Bs molecules of the three sulphurets of lead, copper, and a ternary com- antimony? and is it not more natural to consider it as the 442. result of a quadruple combination of the molecules of sulphur, lead, copper, and antimony? I confess, I am much inclined to consider endellion in the latier point of view, particularly when I observe, that the sulphur, which from the proportion in which it exists in the three sul. phurets should amount to 20-03, forms only 17 hundredths of this substance. In referring endellion to the binary combination. of Composition of galena and fahlertz, the paper above quoted gives the fol- pmeps 5 lowing proportions. Smithson, x galena ce Endellion 3sulphuret ofantimony {3 sulphur gantimony zsulphur #copper From these proportions it would follow, that the suls phuret of lead contains 834 of lead, and 16} of sulphur: that of antimony 834 of antimony, and 163 of sulphur: and that of copper 66% of copper, and 334 of sulphur. The proportion in which the sulphur is said to combine Those of the with the lead in galena, or the sulphuret of this metal, is S¥!Phuzets of ’ , antimony and the same as is given by Mr. Kirwan. As to the two sul- copper differ phurets of antimony and copper, the proportions between a ag the sulphur and the metal result probably from the author’s “own observations, which it is much to be regretted that he has not given. _ _ According to Proust and Bergman, the only two anthors, proportions in ‘as far as‘I know, that have established the proportions of su!phuret of sulphur and antimony in the sulphuret of this metal, the eo ‘sulphur is to the antimony in the proportion of 26 to 74; ‘and this is the proportion hitherto followed by all writers, They have in like manner followed the proportion affixed Proportions in by Klaproth to the sulphur and metal in the sulphuret of ong of copper, which is that of 18°5 to 78:5: and with respect to this sulphuret I will add, that, about the time when I laid y before x fahlertz 2sulphuret of copper } 326 SULPHUREIT OF LEAB, COPPER, AND ANTIMONY. before the Royal Society my first paper on endellion, being desirous of obtaining some additional data with re- spect to the proportion in which sulphur enters into the sul- Analysed by phuret of copper, I requested the favour of Mr. Chenevix Mr. Chenevix. to assist me in my researches, by analysing different varieties of the sulphuret of this metal, with specimens of which I furnished him. This able chemist found in one perfectly pure Cornish specimen, which was regularly crystallized, “19 of sulphur and 81 of copper; a proportion exactly simi- lar to that given by Klaproth, if we consider that the sul. phuret of copper analysed by him contained 2°25 of iron, and 0°75 of silex, which did not exist in that analysed by Mr. Chenevix. Other speci § This gentleman at the sametime, at my request, took the Ny ia trouble to analyse seven other varieties of sulphuret of cop- per; I having supplied him with the specimens, duplicates of which I preserved. One of them only was from Bohemia, and the rest from Cornwall. All of them contained from _ 0°03 to 0:08 of iron, but no other extraneous substance. _ They all gave similar results as to the proportions of sul- \ _phur and copper, except that the quantity of sulphur was: a little greater where the quantity of iron was greater. Mr. Smithson’s Thus it appears to me incontrovertible, that the propor- 2 re pee ©" tion of sulphur, admitted in the paper in question as essen. tial to the composition of sulphuret of copper, is.much too great; and that the proportion of sulphur, there said to en- ter into the composition of sulphuref of antimony, is too small: which would totally overturn the proportions, by which the author of that paper endeayours to prove endel- lion to be produced by a binary combination between sul. phuret of lead, and the gray sulphuret of copper named fahlertz. It is possible, for this sometimes happens in me- tallic sulphurets, that Messrs. Klaproth and Chenevix, in the specimens they analysed, may accidentally have met with varieties of sulphuret of copper, in which sulphur was superabundant, or simply interposed; and in this case their analyses will give too large a proportion: but that two chemists, so eminent for their talents as the gentlemen just mentioned, should constantly find the proportion of sul- phur in this sulphuret much less than is assigned in that pa. per, SULPHURET OF LEAD, COPPER, AND ANTIMONY. 327 per, agrecing at the same time with respect to the propor- tion in which it enters into this compound, is I believe as complete a demonstration, as chemistry can furnish: at least if there be any errour init, the errour must be proved. » The majority of ores in the sul phuretted state, of which Ores of copper copper constitutes a part, being of a gray colour; these olen ores being very numerous ; in some of them the copper be- ing merely interposed ; and in the greater number of those of which it is acomponent part, being commonly inter- mingled with different metals, most of them sulphuretted likewise: nothing is more difficult, than to distinguish these ores, so as to refer each to the principal and particular type, to which it belongs. '. Among the different species, to which these ores may be Fahlertz. referred, it. has uniformly appeared to me, that what the Germans call fahlertz belongs to the gray species that crys- tallizes in regular tetraedra. But this species, in which the Very liable te copper in the sulphuretted state is in pretty large quantity, Se aan, is at the same time oneof those most subject to admit foreign substances by the interposition or juxtaposition of their mole- eules.. As I have already said in my first paper on endellion, presented to the Royal Socisty, it appears to me unquest- ionable, that,.the essential component parts of the gray ‘ tetraedral sulphuret of copper are copper, iron, and sul- phur; and the analysis, which I have there said was made by Mr. Chenevix of a variety from Cornwall in well de. fined, crystals, in which he found nothing but these, in the proportions of copper 0:52, iron 0°33, and sulphur 0-14, seems Sufficient to prove that these substances are thus pro- portioned in this ore. . The author of the paper, when he gives fahlertz as the Mr. Smithson’s second component part of endellion, considered as the pro- a pala duct of a binary combination, says that it is composed of the antimonial 234 sulphur, 50 antimony, and 262 copper; a composition that would constitute a variety among the antimonial ores, and has nothing to do With that I have just given. But as it. differs materially from all the very numerous analyses, that. have bcen made of different varieties of gray copper containing antimony, it must be the result of the author’s own observations, aud a particular series of experiments, which om. 328 SULPHURET OF LEAD, COPPER, AND ANTIMONY. which it would have been of great importance to make known. The attention which the different sulphurets of copper appear to me to deserve, as opinions respecting them are not yet settled, induces me to add to what I have said on the fahlertz, or tetraedral sulphuret of copper and iron, the following reflections. Part of them have already ap. peared in my first paper on endellion ; but the observations which I have subsequently had an opportunity of making on the sulphuret of copper enable me to present these re- flections to the Royal Society again on a larger scale, and in a manner better adapted to illustrate this interesting sub- ject, on which so much uncertainty prevails. Extraneous The substances foreign to fahlertz, or tetraedral gray aeons aia copper, which observation has hitherto shown to be inter- posed in it, are silver, lead, antimony, and arsenic; and very frequently these substances appear to be sulphuretted, as well as the copper. An analysis by Klaproth of a va- riety from Kapnick, in Hungary, has even indicated 0-06 of zinc; and another of avariety from Poratsh, in Upper Hun- gary, 0:0625 of mercury. These substances, several of Examhation of fahlertz. which are sometimes found in the variety, that possesses the property of crystallizing, are no obstacle to crystallization : but there are many other varieties, that appear to be desti- tute of this property. In spite of all the researehes I have been able to make on this subject, I cannot establish in a satisfactory manner the characters, that might serve to make them known: in general the gray colour of the crystallizable varicty is I think less deep, and its lustre more brilliant, but to this there are many exceptions. Allthegraysul- The fahlertz is not the only sulphuret of copper, that is Pune iets: subject to this interposition of foreign substances ; it is the yeign mixture. same with all the gray sulphurets of this metal. The various mixtures they contain has even occasioned different names to be given them, and different opinions to be entertained re. specting their nature. From the silver, which some of its varieties contain, fahlertz had Jong the name of gray silver ; ‘ore. Afterward, when it was found, that a great number ) of other varieties were totally devoid of silver, it was called gray copper ore. An analysis, which Klaproth made of a variety _ 3ULPHURET OF LEAD, COPPER, AND ANTIMONY, 32 variety from Andreasberg in the Hartz, having afforded him 0°34 of lead, occasioned its removal from the copper to the lead ores; among which many German mineralogists. conti- nue to class it, expressing doubts however, respecting the nature of its real component parts. Nothing is more variable than the analyses, that have been made of different gray sul. - phuretted copper ores, taken even among those that are crystallized ; and it is absolutely impossible to found uporé - these any determinate classification of the species and varie- ties of this ore, unless we previously establish certain fixed points, to which we may refer them. In tbis state of things I conceive we ought to consider the Division of t sulphuretted copper ores in two different points uf view ; oe the first regarding those that admit a determinate form ; the second, such as have not hitherto appeared to admit any, as the weissgueltigertz and graugueltigertz of the Germans, &c. Among such of these ores as take a determinate form we Distinction oi ought, I think, to consider as belonging to one species the species. those, that constantly take the same primitive form, or some _one of its modifications. At the head of this we should Simple sulphy place, first, the simple suiphuret of copper, composed of ‘tf copper. - 0°81 copper, and 0:19 sulphur. Its primitive form is a right hexaedral prism, the terminal faces of which are regular hexagons *, and the specific gravity of which is 5.643. * My intention is soon to lay before the 'Royal Society a more complete detail, relating directly to these copper ores, in which the form and dimensions of these crystals will be established. Addition. When | entered into this engagement, I was not aware of the fate, that awaited the paper in which it was inserted. The height of the regular hexaedral prism, forming the primi- Primitive crys tive crystal of the simple sulphuret of copper, is to the apothema § pate gt of the regular hexagon, that serves as its base, in the ratio of 2to 3, ’ a ratio determined from three different substitutions for the edges -of the same hexagons, the planes of which make with the terminal faces for the first an angle of 146° 19’, for thesecond 1389 22’, and for the third 116° 32’. Frequently all the planes owing to these three modifications terminate'the same prism. Often too they reach each others limits, and then giveriseto as many hexaedral pyrainids, either terminating _§ The apothema is a perpendicular line let fall from the centre of the circle in which the hexagon is inscribed, and bisecting any one of its sides. 330 SULPHURET OF LEAD, COPPBR, AND ANTIMONY. 5:643*, This species, when it is perfectly pure, and without. any mixture of iron, may be cut nearly with as much ease as lead, of which it has almost the colour. It cuts perfectly smooth, and with a metallic lustre. This sulphuret alters spontaneously to a deep black by the oxidation of its surface. Varicgatedcop- . 2d, The double combination of copper and iron with per ore. Crystals rare. sulphur, known by the name of bunt kupferertz, which was given it by the Germans, and the composition of which ap- pears to be from 0°60 to 0°65 copper, 0°18 to0:15 iron, and 0:22 to 0:25 sulphur ; proportions deduced from the analyses of ten different spccimens, made by Mr. Chenevix at my re- quest. Its primitive form is a cube+; and its specific gravity terminating in a point, or very nearly so. Frequently these pyra- mids touch each other at their bases, when, the prism disappear- ing, they give rise to three different dodecaedra with isosceles triangular faces. In one of these dodecaedra, the planes meet at the summit at an angle of 112? 38'; in another at one of 96° 52’; and in the third at one of 53° 8’. These crystals are almost pecu- liar to Cornwall; every where else the crystals of sulphuret of copper are very rare. * This specific gravity was given by two very perfect. crystals united together, weighing about 258 grains, and perfectly pure. Authors that have mentioned this substance give its specific gravity: from 4°810 to 5338, Beside that the specific gravity of no sub- stance can vary to such a degree, the greatest is certainly below the truth; it was probably taken from some of its amorphous yarieties; and a great number of trials with these has taught me, that their specific gravity varies considerably; and never equals that of the crystals. No doubt this is owing to cavities in their in- terior, which in fact may be frequently seen on breaking pieces of this sulphuret. In weighing this sulphuret of copper too, we should not take crystals that are grown black or oxided on their surface; the black oxide of copper not being easily permeable to water, there always remains in this case a great deal of air between the surface of the piece of sulphuret and the water in which it is weighed ; and as we cannot entirely free it from this, the specific gravity ob- tained is always much less than it ought to be. + Additional note. The crystals of bunt kupferertz are very sare. Cornwall, which has furnished mineralogists with so many scarce. species of this metal, has produced some very fine groupes, though but few. The cube, which is the primitive crystal of this substance, ie the orny, ' SULPHURET OF LEAD, COPPER, AND ANTIMONY. 331 gravity is 5-033. It is not so-casily cut as the preceding; and the cut, though smooth, has not the same lustre. Its most common colour has the redness of nickel, which is deeper where cut; but if this sulphuret be ever so little de. . composed, it acquires a blueish tint, and afterward assumes the finest colours. 3d, The double combination of copper and iron with Fahlerie. sulphur, but with a larger proportion of iron than the pre» ceding species. It is the fahlertz, or gray sulphuret of cop. per and iron; thecomposition of which is copper 0:52, iron 0°33, and sulphur 0-14; and the specific gravity 4-558. This species is much harder than the preceding; but its hardness varies according to the nature of the different substances frequently interposed: in it. It may be scratched, but not cut; and the place scratched has neither the smoothness nor the lustre of the two foregoing species. Its powder varies from a full black to a black with a reddish cast, or a reddish brown. The latter colour, as far as my observations go, always indicates the presence of silver, which is com- monly in the state of red antimoniated silver. It is much form its crystals most commonly assume. Sometimes the places of Chicfly cubical. its solid angles are occupied by equal sided triangular planes. Very commonly these cubes have their faces slightly curvilinear. At other times they are merely an aggregation, frequently irregular, of other small cubes, which renders their figure very difficult to discriminate. To the bunt kupferertz no doubt should be referred the cube, which Werner, Estner, and several other German mineralogists, give as one of the forms of the simple sulphuret of copper, to which it appears to me incapable of. belonging. As to the octaedron, given likewise by the same authors to the simple sulphuret of cop- per, to which it is equally far from belonging, I presume, that some octaedra of red oxided copper, oxigenized to a maximum at the sutface, and turned black to a less or greater depth, may easily have led to the mistake. Formerly there occurred in Cornwall a Variety. variety of bunt kupferertz in thin laming superimposed on one another, and frequently of a fine blue colour at their surface. ‘This contained iron in smaller proportion than the bunt kupferertz, but sufficient to render the sulphuret of copper incapable of being cut with the knife, and when cut exhibiting the metallic Justre as the simple sulphuret of copper. The fracture presents a coppery red colour, more 332 Copper pyrites. 4 SULPHURET OF LEAD, COPPER, AND ‘ANTIMONY. : more liable to decomposition than either of the preceding, particularly when crystallized. 4th, The double combination of copper and iron with sulphur, which is shining and of a deep yellow colour. We have vo analysis of this species, except that of Lam- padius, who gives for its component parts 41 copper, 17 iron, and 45 sulphur: but it is very probable, that the specimen analysed by him contained a superabundance of sulphur interposed in its substance; and besides, the pro- portion of iron given by this analysis is certainly too small*. From several assays of this copper ore made with Mr. Chenevix, it always appeared to us, that it differed very little, either in its component parts, or in their proportions to each other, from the gray species, which I have said should bear the name of gray sulphuret of copper and iron. The form of its primitive crystal is a regular tetraedron, modifications of which it sometimes admits, though much fewer than the gray sulphuret of copper and iron; and among which we chiefly find the regular octaedron, and the dodecaedron. with rhombic faces; but the latter variety, which occurs in Cornwall, is very rare. The specific gravity of this sulphuret is 4058+. Itis not so hard as the fahlertz. Its fracture is very brilliant, ragged, and as if it were composed of small Jaminz intersecting each other in various directions. In decomposition it assumes the most * Additional note. J have lately seen in the Journal des Mines, No. 122, that Mr. Gueniveau, engineer of mines in France, has analysed two varieties of yellow sulphuret of copper and iron: One, from St. Bel near Lyons, afforded him metallic copper 30, metallic iron 33, and sulphur 36. The other, from Baigorry, yielded me- tallic copper 27°5, metallic iron 29°5, sulphur 31°5§. t This specific gravity is a mean of those of four tetraedral crystals, either perfect, or with their solid angles truncated. Authors have hitherto carried this specific gravity to 4-315: but I presume, that it was not taken from crystals, and that the pieces weighed were mingled with sulphuret of iron, which frequently happens. I have found yellow sulphurets of copper and iron, thus mingled, weighing as high as 4°6. § See Journal, vol. xxi, p. 148. lively SULPHURDT OF LEAD, COPPER, AND ANTIMONY. $33 lively colours, till at last it loses great part of the copper it contained; aud which very frequently in this case, com. bining with carbonic acid, passes to’the state of green cop- per, leaving a residuum of oxide of iron, which however is still sometimes pretty rich in copper, and i is then known by the name of hepatic copper ore. Care must be taken not to confound this double sul- This not to be phuret of copper and iron, as is frequently done, with Sear martial pyrites that contains copper intermingled with its pyrites in substance, commonly in small quantity, though it is some- Aen a 5 times pretty rich in this metal. From this the double sul- phuret is totally different. The form of the martial pyrites ‘containing copper is either a cube, and this commonly ‘striated, or a regular octaedren. The martial pyrites is likewise much harder than the yellow sulphuret of copper and iron, and it is heavier, its mean specific gravity being 4-944*. It must appear very strange, that this sulphuret, having great analogy in its component parts, as well as in its form, with the gray sulphuret, or fahlertz, should have a colour so very different from it, as well as from all the other sulphurets of copper. Endeavouring to account for Cause of the this, I have always been ied to think, that this difference of epee = colour might arise from the iron’s being in the perfectly metallic state in the yellow sulphuret of copper and iron, as itis in the martial pyrites, while in the gray sulphuret it is oxided. This opinion however I only mention as a great probability +. In '* This specific gravity is a mean of those taken from crystals all of different forms. Authors give for it from 4°100 to 4:749. Cer- tainly however they have not taken it in the same manner from crystals, bit frem amorphous masses; or at least it must have been from very impure crystals, otherwise they would not have varied from 4:1 to more than 4:7; and it would even have been found superior to this maximum. . + Lhave observed with the greatest satisfaction, that the opinion I had Jong embraced respecting the cause of the difference of colour between the yellow sulphuret of copper and iron and the gray, and which was inserted in my first paper on endellion presented to the Royal Society, has been verified by the analyses made by Mr. Gueniveau of two varieties of yellow sulphuret of copper and irop froin * 334 Another spe- cies, ‘This division proposed as a standard. SULPHURET OF LEAD, COPPER, AND ANTIMONY In this case perhaps it would be necessary to make a 5th species among the sulphurets of copper of an ore, which was formerly very plentiful in Cornwall, but is now become rather scarce, and which probably differs from the preceding species by a more or less considerable degree of oxidation in theiron. This oreis of a dull yellow colour, inclining a little green. Its fracture is smooth and dull, and sometimes a little conchoidal. Its grain is extremely fine, and freqnently even imperceptible to the eye. Its texture consists of parallel Jayers, very thin, and distinguishable only by the assistance of a lens, but easily separated by a stroke of the hammer. This ore has never exhibited to me any crystalline form; but it is frequently mamillary, much like the martial hematites. Its surface is commonly smooth, a good deal like that of a mctal which has lost its polish. Its specific gravity is 4:157: consequently a little greater than that of the preceding yellow sulphuret of copper and iron. Its hardness is nearly the same. If scratched with a knife,. the part scratched appears smooth, and acquires a metallic lustre. On decomposition the surface frequently assumes various colours, but less lively and brilliant than those of the lamellar yellow sulphuret. At other times its surface grows black from the oxidation of the copper, having a good deal the look of an antique bronze, and the more so as it is often partially covered with malachite. This species is frequently mixed with simple sulphuret of copper, a phenomenon by no means so common in the yellow species which I have just mentioned above. This division of the sulphurets of copper, being once adopted, might be considered as a standard, to which we might refer all the numerous varieties, that exhibit no marks of crystallization; arranging them under one or other of these species, according to the manner in which their es. sential component parts are proportioned. We might then from St. Bel and Baigorry, which I have noticed. In these analyses given in the Journal des Mines, No. 122, the author says expressly, that the iron in these yellow sulphurets was in the metallic state; while in two other analyses made of varieties of the simple sulphuret of copper from Siberia, which were probably in amorphous masses and contained iron, he says the iron was In the state of oxide. place SULPHURET OF LEAD, COPPER, AND ANTIMONY. 335 place in a second division such as appear not to agree with any of those already known and classed among the species properly so called; and this division may be subdivided at pleasure, as may appear necessary for the establishment of order and perspicuity. 3 It is obvious, that in fact, the species existing among the Ext raneou ” sulphuretted ores of copper being perfectly known from the itr oe ses sum of the characters essentially necessary to ascertain them, ture, but may -the silver, lead, antimony, arsenic, &c., which happen to pe seep be intermingled with them, are perfectly extraneous, and ticties. do not in the least alter their essential nature. These inter- “mingled substances once known, they may give rise to sub- divisions of varieties; but these subdivisions themselves would become very numerous, if proper limits were not assigned to them. In the fahlertz, for example, from the great tendency it has to receive into its substance an inter- mixture of a great number of others, I am persuaded, that we should be obliged to make almost as many subdivisions as we analysed specimens. A collection of minerals I lately received from Russia con- New variety. vinces me, that we are yet far from knowing all the gray sul- phuretted ores, of which copper forms a component part, or in which it is simply interposed or accidental. Among the specimens in it was one bearing the name of a substance, which certainly did not belong to it; and the appearance of which, differing from that of every analogous substance that I recollected, particularly caught my atten- tion. As this specimen affords anew and interesting variety of the simple sulphurets of copper; and affords me an op- _ portunity of showing how we may sometimes discover, that a substance is simply intermingled with another, and not ‘combined with it, a point frequently difficult to determine ; IL will enlarge upon it for a few moments. This substance, which is in small separate pieces in- Described. terspersed in a quartz, partly compact and partly lamellar, is of a fine, close, compact grain, and of a hardness nearly equal to that of fahlertz, or gray sulphuret of copper and fron. Its colour is a duller gray, and its fracture is more smooth. Its specific gravity is 4°554. Well assured that this substance was not nickel, under the name of which it had 336 Analysed. SULPHURET OF LEAD, COPPER, AND ANTIMONY. had been sent me, I requested Dr. Wollaston, to have the goodness to ascertain its nature. His examination informed him, that it contained nothing but sulphur, copper, and antimony. Desirous of ascertaining if possible, whether the antimony were combined with the copper in it, or simply intermingled with the sulphuret of this metal; and this ore being soluble, though very slowly, in cold nitric acid; I first of all dissolved it in this acid. A part only of the sulphur rose to the surface of the solution; and itis pro- bable, that the rest was converted into sulphuric acid. The copper dissolved entirely, and the antimony was precipitated in the state of oxide. The latter, to judge from the size of the specimen I had set to dissolve, was evidently in smaller proportion than the copper. As this same substance is exe tremely fusible, I brought a thin piece, about four lines long, to the state of fusion, and kept it so for a short time. Great part of the antimony sublimed, covering the surface of the body on which it rested with a white powder. The fragment when cooled retained its form, and even its bulk. On breaking it afterward, its fracture exhibited an aspect exactly resembling that of the sulphuretted copper which is produced by the last fusien, it could be cut with the same facility, and the cut had a metallic lustre. Having after- ward placed this fragment, which had been fused, in cold nitric acid, and a fragment of simple sulphuret of copper along with it by way of comparison, they both dissolved slowly, comporting themselves exactly in the same manner, and the solution contained nothing but copper. The-so- lution of each of these fragments produced the same black, flocculent, and very light precipitate, which was nothing but sulphur still united with a small portion of copper, which, no doubt, was the cause of its black colour. From these details it appears to me there can be no doubt, that the ore was a simple sulphuret of copper, with which antimony, probably in the state of a sulphuret likewise, was intere mingled. This substance came from Roane near Catharinenbourg, in Siberia. H. On EFFECTS OF THE GRAFTING AND BUDDING OF TREES. 38337 If, On the Effects produced by the grafting und budding of Trees.- In a Letier from Mrs. Agnes Isperson. To Mr. NICHOLSON. SIR, W uen I first began the study of grafting and bidding Design of the by dissection, in order to judge of the effect produced in2™”°- trees by such an operation, it was my design to collect all the knowledge disseminated in every author on the subject, and by joining it with what I should attain by dissection myself, offer to the public a treatise, that might at least serve as a sort of standard of our knowledge in this art. After dissecting therefore an innumerable number of grafts ‘ and buds of every different tree, commonly grafted and budded, and at different distances of time, making drawings as exact as possible, and committing my own observations to paper ; I was anxious to see what other botanists had ‘said on the subject. But great was my astonishment to find, that The subject scarce any author had really investigated the matter. Even is a Miller gives only a few common rules for practice, without observations. The scientific Mirbel (in whose work I hoped to find important information) gives only a. short note, and a reference to Duhamel; Malpighi and Grew are totally silent; and Dr. Smith and Willdenouw are equally ~neglectful of the subject: yet it appeared to me to be in Yet highly im- every respect that which promised the most impertant in. Pt@t struction with regard to the manner in which trees are formed, to show the process of each different part, and produce evidence which no other situation of the vegetable world is capable of giving. Nor.was I deceived, I think; ~ for by this sort of dissection I have learnt more of the real nature of the different parts, than any other investigation of plants ever taught me; since they are brought forward in a state, that obliges them to exert their powers, and ~ much may be drawn from the curious struggle for life, which points out to notice every important part. _ Finding that from Duhamel alone I was to expect any Duhamel’s Pariation, that was not merely practical: I with great ,, “ar Vou, XXIV.—Surrrement. Z trouble 338 EFFECTS OF THE GRAFTING AND BUDDING OF ‘TREES. trouble at last procured his work. Itis indeed a book full of most admirable imstruction, and though it has but little beyond practical observations on this subject, yet, as far as he proceeds in investigating causes, it isexcellent: but here again the want of the opake solar microscope has prevent- ed the possibility of his proceeding farther, and knowing whether the parts did, or did not unite. This~ being the case, I must trust wholly to myself for the anatomical part, and the consequences arising from them; but as I shall give asketch of the exact change made by the uniting of the two branches. J hope my figures will prove the truth of my assertions. Object of graft- The use of grafting and budding is to propagate any rie Sea particular tree: the wood or fruit of which pleases the eye or palate; as the only means we possess of procuring a Why seedling perfect imitation. It is a well known fact, that seeds a pea, seldom produce the exact prototype of the plant from which they spring; and the reason is plain; the tree is only the _mother of the blossom, but to complete the resemblance, - it must be impregnated by the stamen of the same plant. Now if the wind blows the ripened dust of the stamens from a neighbouring tree of ‘the same order, when the blossoms of the first’ are covered with the juice of the pistil, the blossoms thus prepared will receive the powder, and the consequence will probably be a new variety of fruit, if the seed is planted; and not the same fruit which the original tree gave. ‘Thus are produced more than half our sorts of apples, peaches, and innumerable flowers ; for we neglect to examine the origin of the varieties that take place in our gardens, or we should continually be able to trace | them to this source. Budding and But in grafting and budding, this cannot be the case, no Laon Dee iia resemblance can be so exact ; itis indeed merely an increase continues t s f _ same tree. of the tree, from which the scion is taken. Every one knows, that grafting is taking a shoot from one tree and inserting it into another, in such a manner, that both may unite closely, and become one tree. Mr. Bradley (from some observations of Agricola) suggests what anatomising the parts first proves, that the stock serves merely as pipes te convey the medicated nourishment to the scion; that the ‘gcioa ~ EFFECTS OF THE GRAFTING AND BUDDING OF TREES. 339 Scion preserves its natural purity unmixed or uncontaminated with any other juice: and, as we have since discovered, that all sap is nearly thesame, being merely the juices of the earth ; and that it is the blood which ruis in the bark alone which gives taste and variety to the tree; so the scion can in no way be altered by the stock, without. the juice of the bark runs into it. Now it is most certain, that this is not No unionof the the case; for the barks never join so as to communicate ae ingle juice, as I shal show when I describe the alteration madeings. in the parts in contact. The scion or bud (for it is the same in both) is placed on the graft or stock as in the earth; but, instead of having to prepare its own sap (which the infant plant is obliged to do before its root grows) it finds this ready medicated for it, and fitted for its more advanced ~ state, to push it forth with a vigour truly wonderful. To graft is merely therefore to form a tree in a far quicker manner than a seed could; and in very delicate plants to take away from them all the dangers attending their infant state ; and at once place them in maturity. This is the real object of grafting and budding. I cannot agree with Mr, Foresyth, that the juices, when Juices of the they arrive at the scion, must have a more easy, plentiful, stock not more : Se eat: ann : agreeable to the and perfect assimilation, than if they were its own; for the cion. scion can only do well, when the vessels of the stock agree perfectly with its vessels. Its own cylinders must therefore more perfectly assimilate than any stranger tree can. Still, if the wood vessels suit each other, we may be satisfied that the plant will do well. This is indeed of such extreme consequence, that of the number I have examined which I had budded and grafted for trials of various trees, more than thirty have died from the difference of the size of the two woods; for does it not stand to reason, that, if you try to force a quantity of water from a large vessel into a small one, it will burst the smali one: or, if itis the small 4 one, that pours its contents into the large one, it will not half fill it, and the vessel will be pressed with too much air, that will pour in to supply the place of water; and the vessel will equally burst. This is literally the case in the two woods that are to be joined together, whether in plethory or emptiness ef sap, théy equally burst, butin the : Be first, 340 Grafting and budding similar m effect, w but budding preferable. / EFFECTS OF THE GRAFTING AND BUDDING OF TREES. / first, the whole is wet and full of juice ; and in the latter, the parts are shrunk and dried up. I must now mention, that, though grafting and budding , ate so very differently performed, yet in their effect they are perfectly the same; the first being the planting several buds, the latter only one: but there are some reasons, that make the last infinitely to be preferred, where it can be. donc: and I doubt not it succeeds much oftencr, as I shall show at the conclusion of this letter. I shall now proceed to the alteration effected in the bud and graft by the opera- Effects of graft- tion. The first observation on cutting a graft, after it has ing. been done about two or three months, is, that all the part _ between the two plants is filled with a moist substance ; Junction of the anks. % which upon magnifying you perceive to be the same wood as the scion, onlyloose, and incomplete. Next a white line is seen struggling through this loose wood, and soon reach- ing ina very undulating manner from thestock to the scion. It always begins at the stock. ‘To perfect this line, which is the circle of life, six weeks are required. I never saw it perfected in less. The next is the formation of what Diiijaaien calls the bourrelet, that isa species of bolster of new bark, formed from the oid juice of the stock, which, being prevented from continuing its course to form new bark, runs down the division of the two branches, and joins them witha new piece: for let the barks be laid ever so close, or even wrapped one on the other, the old barks will never join; and it is necessary, that a piece of new bark should cement | the two edges. But the juice stops at the end of the join, and it is perceptible by the extreme dryness of the two edges, (so different from the rest,) that no juice passes from one to the other. Grafting cannot There is no communication therefore between the barks improve fruit, Repeated grafting is a bad practice. of the two branches, of course the bark of the scion is pure and unalloyed. How then is grafting or budding to meliorate a fruit? I believe, that there is not any thing more certain, than that it makes no change whatever; and that there is no practise that repays so ill as that of repeat. edly grafting, and cutting down plants. It must exhaust, and I have heard an exeellent old gardener say, who has prac- tised EFFECTS OF THE GRAFTING AND BUDDING OF TREES. 84) tised this art for thirty years; that he, after years of ree peated trial, was perfectly convinced of this truth. The next thing to be observed in a graft or bud is the row New weod. of new wood ronnd the division between the bark and wood, In the common beech for stock, the scion being the copper beech, the new wood is always of a pink colour, by which means it displays the mixture formed with the wood of the stock, which is perfectly white. See (PI. 1X, Fig 1,) a graft of one year, the scion not only increased at, p. p, the usual way, but continued rounds are added till they mect; and the whole of the stock is eradicated. There is a very peculiar appearance in the wood of the scion and graft, which well proves that they can in some measure alter the direction of their vessels, even after the regular formation of the wood; itis the undulating form, ~- sometimes absolute twisting and turning of the vessels, which Duhamel notices, and which, he adds, strongly re. sembles that in glands in animal bodies after a great incision. And thence he infers, that a new sort of viscus takes place, where the two branches join; which most probably must greatly meliorate the fruit of the scion. Unless Duhamel had tasted human flesh before and after amputation; I know not how he could draw such an inference on the melioration of flavour. If he found it corrected the taste of the former, he might indeed draw the same inference in favour of the fruit. Or I should suppose it was much more natural to infer, that this undulation was caused by nature being disturbed in her office, and by the struggle the circle of life makes, to pass to the new braneh, which soon however subsides, a few inches higher: and as to the new viscus, when placed in the solar microscope, it proved exactly the same wood as the scion. There has long existed a dispute with respect to the Formation of manner in which the bark and wood are formed, which, it the bark and appears to me, dissecting grafts is the true way of elucidat- ee ing and deciding. It is most plain, that the bark and wood have not the smallest connection, but that which the attaching of the flower bud to the wood occasions. I have been long of this opinion, and my present occupation has gonfirmed the idea, I think indeed, I have a specimen, : ; that 342 Lusus nature. EFFECTS OF THE GRAFTING AND BUDDING. OF TREES, that would convince the most unbelieving, and prove, that the process of the formation of the wood proceeds in this manner. When the sap begins to rise, it detaches the rind, the bark, and inner bark, in one close layer, from the wood; and they, being disposed to grow faster than the inner part of the stem, increase as muchas the fastening of. the flower buds to the wood will permit. The sap then forms the new wood in the intervening space, and a band is completed each year. I found some time ago a lusus nature, which teaches more than all I can say on the subject; and I have given as exact a drawing of it as I could make. See pl. x. jig, l. On looking at some plants, I observed a Portugal laurel ap- peared in a very strange state ; and on examining it, I per- ceived some accident had separated the rind, bark, and inner bark, in two regular bands, from the stem of the tree. Still, however, the ends were attached, but, the loose part, co being at liberty, had so aay increased i in length, that it was more than double the measure of the piece of stem it originally covered. It had broken the trifling hold of the nourishing vessels, and that of the flower buds, which, when I found it, were perfectly dead, but still it had thrown out its leaves, and was forming fresh ones. On dissecting the leaves, there appeared no nourishing vessels, or their emptiness prevented their being, distinguished ; and the spiral wire was ouly to be found Tow, and then, and in, a broken and dilapidated state. I deeply regretted the hav ing separated the branch from the stem, before I knew what it was. Butitisstill a very great curiosity, and explains well, the powers of the different parts. Te plainly marks, that, therind, bark, and inner bark, are the formers of the leaves; and that though they Reh Aer pa: ‘t of their nourishment, from the nourishing vessels which spring from, the wooed, yet they can expand and form without them. They did not, indeed appear in perfect health, nor could it be expected, as their whole nourishment came from the dew they, rep. ceived, and the carbonic acid gas they inhaled, The i inner bark vessels were full of the blood of the plant, and did. not appear to evaporate in any manner, ‘though one side Was. €X- posed; which shows how very complete Bt be the sepae. ration between the blood of the plant and its sap. ‘ : t EFFECTS OF THE GRAFTING AND” BUDDING OF TREES. 343 ~Itstrongly indicates too, how impossible it is to gain a Difficult to at- thorough idea of the juices of trees, since to procure them jegre ae they must be mixed; and no person can, I think, dissect different juices trees without perceiving the astonishing pains nature takes® "°° to prevent this mixture, which would probably render futile all the intentions of nature. How then are we to judge of them, when we get them only by wounding the tree? in barking we get two juices of a very different nature, for thatin the rindis purer than the sap in general, and often very bitter; then thereis the juice of the circle of life, which is clammy, and approaching to syrup; and an almost plain water, that is often tobe found concealed between the folds of the pith. All these should be procured singly, to be able:to understand them. I shall now returm to the grafts: having described as yroog of grafts minutely as possible the manner in which the two branches requires a new of the grafts join, I shall mention also, that the woods as Rice ae wellas the bark must have a new piece to join the wood of the stosk and scion together; as will be seen in the plate.. It often happens that the white undulating line be- fore mentioned, which is the line of life, a litile intercepts their meeting, but this is soon conquered ; the line of life is always to be traced from the pith of the stock to the pith of the scion, as if to establish the communication of life, which adds another proof to those before adduced in my Ath letter, (See vol. xxiii, p. 334,) that it is the most im- portant part of the plant, and truly what I have named it, the circle of life, or. propagation, In looking over Duha- mel, ‘I was not a little pleased to see he had marked its con. sequence, but was uncertain what to call it. I'shall now mention the folly of expecting heterogeneous Heterogeneous mixtures in grafting or budding to succeed, black noses, ae pie &c. That a plant should be capable of receiving its nou-ding cannot rishment through the cylinders of another plant, is astonish. succeeds ing; but it must at once appear how much this miracle must be increased, if two plants are taken, which in their nature are wholly different. .That such a mixture may be made by applying the powder of the stamen of'one plant to "the pistil of another, I know, but not in the way of graft: ~ 344 Wood. Hydrangia. EFFECTS OF THE GRAFTING AND BUDDING OF TREES. that new grafting an old tree, and cutting it down, may make it bear fruit, when it would not before, I believe ; because to cut and pare a tree always infuses fresh vigour | into it; for the momentary flow is more hasty, it has the power therefore of clearing away all intervening objects, that might prevent the more perfect flow of thesap ; but all this is very different from allying two objects of a distinct nature. Resolved, however, not to trust any thing to rea- soning alone, I grafted many of these trees myself, and got an excellent gardener to graft and bud a number. Most of them died before the year came round to cut them; but a chesnut on a palm lived much longer, though it was de- caying. Some died because the juices of the circle of life coagulated with the juices of the pith on meeting; at least there was a strange substance, that had much this appear- ance: others died from the irregular size of the wood. But I have a number now, that I mean to give a more exact account of than I am at present prepared todo; which will illustrate this subject in a manner to leave, I hope, no doubts concerning the impossibity of joining these heteroge. neous mixtures, which nature never intended should meet. I shall now close my letter with some observations con- cerning the wood. The newly inflating the dead wood is not peculiar to grafis; for it is seen in the spring in many plants, as was exemplified in one of my letters, in which I - showed how the graft was revived. The dissecting of grafts has at least this advantage, it adduces fresh proof of the simplicity of the formation of the wood, and showing it to consist entirely of cylindrical passages for the current of sap. These can not only be inflated with other juices as well as their own, but the wood will remain for many months in perfect form, without decay, though they are empty. The hydrangia exemplifies this each year in a way so eu. rious, thatit is worth laying before the public. The whole of the stalk dies away, except the cylinders of wood, the rows of pith, and the rind, so that there remains a total vacancy between the rind and wood. The bark and inner bark decay, and fallaway to powder. The life dies down to the earth, and there remains in a torpid state, tilla few fine days in EFFECTS OF THE GRAFTING AND BUDDING OF TREES. in the spring revive it, and give it strength to shoot forth, and run in its few simple vessels up to the top of the dead wood. Warmer weather throws up the sap to the top of the old wood vessels, by the pressure of air below; but the vacuum existing between the rind and bark prevents the juice filling the last row or two of the wood, and gives it the appearance of a fresh rind, which I at first took it for; but on placing it in the solar microscope, I found it was the last row of the wood. If you take off the rind at this time, it will be found standing hollow, with an ap- parent rind skin on the wood. After atime the blood of the plant begins to form; though in what manner I have not the most distant idea, for it does not appear to me to have any connection with the root. I do not however say it has not: but Iam now deeply studying this part, which _ is that I know the least of. I hope however to make it my winter study, as I have been collecting specimens for more than two years for the purpose, and have now a large collection of drawings from which I have not yet been able to take the results, for want of time, and the interference of grafting and budding. As soon as the blood is formed, the bark’and inner bark begin to grow, and I was sur- prised to see, that they grew exactly in the same manner as the bourrelets in the graft (see Pl. IX, fig. 6 and.10.) At first I could not reconcile this form to the usual form of the growth of the bark, which is much the same in most plants ; but it is its inflated appearance, that disguises its natural shape, and hides part of the lines as is seenatdd. It ap- pears very evidently to prove, that there is no return of the blood of the plant: it will not then be called a circulation. I cannot therefore agree with the gentlemen,.who did me the honour to notice my letters in the Panorama I think, - but I have not seen it, a friend having copied this remark to send me.) ‘‘ That the holes in the cylinders of the blood vessels were intended to prevent the return of the blood, or vegetable juice.”” Now there being so little motion in a plant is the very reason, I should suppose, why it will be the less likely to run contrary to the manner in which it was intended; and I do not believe, that there is any circulation in this part. ; But 345 346 EFFECTS OF THE GRAFTING AND. BUDDING OF TREES.- Plants and But ingenious as the idea is, there is not any thing, I meres Se i confess, that appears to.me more fallacious, than the com. pared. parison between the animal and plant; or that causes more mistakes, The one has.action, the other only motion; the one has volition, the other is a mere machine. It would at first sight be more to the purpose therefore, to compare it to. any of our works of this kind, if the plant had not life, which must render every comparison futile. In the infant plant there is some resemblance to an animal; but:it has caused more errours,, and more delayed the progress of phytology, than any fashionable idea I am acquainted with. Where find a comparison for that, which is evidently a machine, but one that has life without volition; that is formed with such ingenuity as to combine its powers, ex- tract its juices, decompose, and recompose its gasses, and deduce from a combination of the whole new life, aad new beings? Mirbel alone has classed it in amanner worthy of itself. ‘* The vegetable world,” (says he,) ‘¢ isthe division. between the organised and unorganised parts of creation : it gives life to the unorganised substances of the Earth, changing them into living vegetables, for the support of animal life.” I am, Sir, Your obliged Servant, AGNES IBBETSON, Cowley Cot, 22d Oct. III. ‘On the Defects of grafting und budding. By Mrs. Acnes Ipnetson. To Mr, NICHOLSON, SIR, Important in I SHALL now continue my subject. The most important grafting, that part toward making grafting and budding perfectly succeed ere is, that the woods of the stock and scion ‘should exactly as-* should be similate, and ‘be enabled intimately to connect ‘with each meget other. To prove how very necessary this, is to the joining of Sez “Tt DEFECTS OF GRAFTING AND BUDDING. SAT of the two parts, I have given a sketch of woods, of ‘dif. ferent patteTns, to show the impossibility of their meeting and carrying on the circulation, unless they agree in every respect; and that each contains a pretty equal. quantity of sap. (See Pl. X, Fig. 2, 3, 4, 5.) Conceive each of these circular apertures to be cylinders, and supposing a quantity of similar vessels laid close to each,other in rows, and that for the use of some machine a double quantity of vessels was wanted, to make it. deuble the height, to convey the liquid on through this whole series; would it not be most apparent, that the vessels so applied for the continuation of the pipes.should be formed.of the same size, and of the same shape, as the first ?, and. that, if they were either larger, or smaller,.the liquid would escape.in pouring from one set tothe other? Just.so it is with the cylinders in the wood yessels of the, stock and scion: except. that, having no apertures from which the sap can escape, it bursts the under vessels, that should contain it. _ The next thing necessary is, that the time for the flowing And also the of the.sap should; be, nearly, the same both in the stock and ow praca scion,;. for every tree has its own peculiar period for. this operation, and the energy with which it acts at that time ig to be traced to the most distant leaf. The current is then very great, and, the effort, it makes is infinitely superior ta its motion.on, any other, occasion. . If any obstruction has - takem place before in the inner part of the tree, either. by the introduction of a worm, or the piercing through of any, cryptogamia no’ uncommon accident) this is, the clearing time ;. as the tree has then strength enough to force away all heterogeneous matter, that hurts or. impedes its growth. If therefore, the.scion should advance to this, period before. the stock, it will want,the sap to act.with, and be debilitated - and starved, till the time for the stock arrives, when it will have lost its energy: and if the flow of the sap takes place in the stock first, the vessels of the scion will not be ready for.its reception, and it will probably burst them. I have a often, found it, in, this state. In the) one case, the scion appears shrivelled in its upper leaves, in the othen it leaks. at the graft, and decays often by slow degrees, The 3A8 Rain and strong sunshine to be avoided. Nurseries of stocks should mot be over crowded, DEFECTS OF GRAFTENG AND BUDDING. The third point is, that there should be no grafting or budding in rainy weather, or in very strong sunshine. The first is apt to swell the graft and buds, and overload them with moisture, so that they are killed with plethora; and too much sun dries up the bark and rind, and draws off the moisture, so that the bark draws itself up from the bark of the stock, and they are forced asunder. The gardener imagines it is owing to the thickness of the rind, whereas it is generally his own fault: many disappoint themselves, because they cannot bear to leave off, when they have ouce begun. Great care should also be taken, that the nursery, from which the stocks are brought, is not over crowded, and yet this appears to me to be little thought of. Noone, who does not dissect vegetables, or trees in particular, can have an idea how much they are the children of habit. One vessel by the accidental pressure of another, or some trifle, gets a twist, which is followed by the next, and so on by a third; the daily impression continues; the plant grows stiffer, and therefore more incapable of being righted; tilt the whole tree takes a spurious shape, frem so trifling and minute a cause, that no one would credit it, if remembered. There is not any thing more beautiful than a well grown tree, if proper pains were taken to make it straight, and wel} shaped. To graft it, is certainly to give it a defect; but if well grafted, the injury is small, as it should be little in- creased in size at the grafting place. A grafting or budding, that can be easily pointed out six or eight years after, is badly performed; and one that enlarges the tree where it is’ budded is badly done. If gardeners would encourage their grafters to be double the time about it, they would find their account in it. The smallest quantity of air introduced increases instead of banishing the rot already there. In cutting 120 grafts, and 90 buds, more than 70 of the grafts had so much rot in them as could not be banished without great care; for when there is rot, if a severe frost comes, and this part is not guarded, the frost attacks it,’ and the decay increases.. The first proof of this is the shrinking of the most distant branches, : There PEYECTS OF GRAFTING AND BUDDING. 349 There are very few grafts entirely without rot. The Fewgraftswith- — example I have given at Fig. 1, Pl. IX, has less defect °F ™e% an than is usually found, the puleag aie trifling degrees of decay, and would soon have been banished, if kept from the air. I know but one way of doing this, which is Remedy. by placing a composition on the place, when the clay or bass mat is taken off. I know none better than Foresyth’s. Any composition that will keep out the air, and not crack, willdo: but his having been tried, and warranted by such competent judges, must have the necessary qualities one 0 would suppose. I knew a gentleman, who always covered his trees, whether grafted or wounded, with a plaster of this kind; and his grafts and buds were truly a picture, He did it for two or three years, according to the appear- ance: a bud but half the time. Within this space all danger is over. It is a method that would save thousands of trees, ifadopted. If the number of grafts, that die between the 3rd and 6th year, were counted, they would perhaps be found nearly one eighth of those that survive the first operation. J havea collection of grafts between those ages, that well show the danger arising from this constant in- crease of rot: which will almost inevitably take place in every graft, when first performed, if not well guarded from the air: but if, when the clay is taken off, the plaster is put on, and renewed every six months for two years; or, if delicate, three; all danger would he at an end. The joining of the bark would have been renewed by that time, and taking off the plaster by degrees, the rind would be fresh and hardened. On the contrary the method of performing the operation Common mode is this. A> certain time is marked out for itat most nurseries, ° 8'fung. The weather is little attended to, either in grafting or bud- ding; because the hurry of business will not admit ef such nicety. It is supposed, that, if the shoot takes, all is well: but not one ina thousand is really joined when the clay is taken off. The operator should. have a common little microscope, which woud show him, that they are so open as to admit air enongh to destroy half, though to common observation they appear closed. In this state they are prepared for selling. Some will live two, three, or four years; $50 Decay of the apricot. Canker. Grafted beech. DEFECTS OF GRAFTING AND BUDDING. years; but if cut they would show, that they carry their cértain death with them. The gardeners indeed may say, to manage them in this careful manner would take so much time, as would ruin us; for the price is not adequate. Certainly not; but it would better answer to a gentleman, to give half a guinea for a good tree, that would live ; than buy ten for a shilling a piece, that will die just when they should bear well; and many, JI dare say, would prefer it. I have this year cut two to endeavour to discover the cause of the decay of the apricot, particularly the Anson, which loses a limb each year. In vain I searched every part for the defect, till I came to the graft, and then it was visible enough: for the separate parts of the wood had decayed just as it led to each of the large branches, till there were but two left. The canker very usually begins there. I was examining a small copper beech tree, grafted on the common, six years old. I thought it appeared sickly from the uncleanly appearance of its leaves; for it is certain, that when a tree grows unhealthy its juices grow saveeter ; and the insects therefore seize it with double avidity. This had its beautiful leaves much disguised with the filth of the vermin that swarmed on it. I examined every part, till IT observed a great enlargement about the graft. The rind was loose, and on making an incision, I found the . bark all decayed to powder, half way up the tree; and I Budding. took from it above a pint of woodlice. On examining it had certainly arisen from the rot in the graft: which had never been well joined; and which had soon allowed these ereatures to form themselves a habitation between the two barks. This spread by degrees; and had [ not discovered it, the tree would soon have died; but by a proper appli- cation of the composition, and cutting away all the decayed parts, I doubt not it may do well. I was not a little surprised to see Mr. Foresyth advise the cutting three inches above the bud, which is certainly leaving great room for rot to accumulate. I shall now mention the difference between budding and grafting, and the reason for giving a preference to the former. There is in my opinion no comparison between them, so infinitely superior is the 5 . k IV. ) "0" Experiments on Ammonia, and an Account of a new Me. thod of analyzing it, by Combustion with Oxigen, and other Gasses; in a Letter to Humpury Davy, Esq. Sec. R.S. &c., from Wiit1am Henry, M.D. F. RL S., V. P. of the Ltt. and Phil. Society, and Phy ysictan to the Infirmary at Manchester * MY DEAR SIR, I Should sooner have communicated the account, which you are so good as to request, of my further experiments on the decomposition of ammonia, if I had not beenanxious to ob- tain, by frequent and careful repetition of them, resalts not affected by any of those numerous causes of errour, which_ _easily insinuate themselves into processes of so much deli- Supposed evo- cacy. You have'already been informed, that the fact, which ae ae I lately mentioned to you, (tending to prove the existence ammonia. of oxigen as an element of the volatile alkali, by the dis. covery of oxigen gas in'the products of its analysis) is not entitled to confidence, owing to the admission of a small quantity of atmospherical air, in a way which was notat all suspected. Frequent repetitions of the same process, under circumstances wholly unobjectionable, have fully satisfied “me, ‘that no’ portion whatsoever of oxigen gas is evolved by ‘electricity from ammonia, even when, by means ofan appa- ratus constructed for the purpose, the only metallicsurface, exposed to the gas, consists of ‘the sections of two platina wires, each <5 of an inch in diameter, the wires themselves being enclosed in glass tubes which are sealed hermetically round them, and then ground away, so,as to expose only © the points. Nor does any difference in the nature of the pro- ducts arise from electrifying the gas either under increased or diminished pressure, the latter of which, it appeared * Philos, Trans. for 1809, p, 190. This letter, in its original form, was read to the Society, May-the 18th, 1809, some ‘new observations were added, and some corrections furnished by the author, in consequence, of sybsequent experiments made in June; it was transmitted to the Secretary for publication, July the 10th, to i ey NEW METHOD OF ANALYSING AMMONIA. . 959 to me probable, from the known influence of elasticity in impeding the combination of gaseous bases, might pre. vent the oxigen of the alkali from uniting with hidrogen to form water, and occasion the expansion of both into the state of gas, Having failed, therefore, to acquire, in this way, proof senna Pra- of the existence of oxigen in the volatile alkali, L was next ¢om it. led to seek for some unequivocal mode of evincing the pro- duction of water by the same operation; a fact, which would be scarcely less satisfactory in establishing oxigen te be one of its constituents, than the actual separation of oxigen gas. The most careful observation of ammonia, dur. ‘ing and after the agency of electricity, does not discover the smallest perceptible quantity of moisture. In order, there- fore to subject the gas to a satisfactory test, I had recourse to the following contrivance. Ammoniacal gas, I had pre. viously found, may be so far desiccated by exposure to caustic potash, as to show no traces of condensed moisture Ammoniacal an the inner surface of a thin glass vessel containing it, ae ae -when exposed to a cold of Q° Fahrenheit; though the recent gas, by the same treatment, is made to depofit water in the state of a thin film of ice. A glass globe, of the capa- city of between two and three cubical inches, was filled with gaseous ammonia, which was then dried hy sticks of pure potash, fastened to pieces of steel wire, so that they could be withdrawn, after having exerted their full action. This point of dryness was ascertained by applying wther, or a mixture of snow and salt, to the outside of the globe. By means of a peculiar apparatus, the gas was next strongly electrified, and the cooling power was again applied to the and then elec ; 7 : ' trified. outer surface of the globe. In the first trials, that were made with this apparatus, Moistie ap- water certainly seemed to have been formed by the electvi- peared, zation of the alkaline gas; for the same portion of gas, which was not affected by a freezing mixture before the process, gave evident signs of condensed moisture, when the cooling power was applied after long continued electri. gation. The appearance was not only quite satisfactory to myself, but to Mr. Dalton, and several other chemicak ‘ friends, to whom i showed the experiment. Einding, how- i ever, 2 360 but varying in degree. The experi- ment repeated with great pre- caution, Little or no Micisture, Avidity of am- monia for -moi- sture. NEW METHOD .OF ANALYSING AMMONIA. ever, that the appearance varied as to its degree, I was in. duced to repeat the process with redoubled precaution; fill- ing the globe, previously heated with hot mercury, and drying not.only the quicksilver, but the iron cistern which containedit, by exposure to long continued heat. The elec. trified gas now betrayed no signs of moisture on the applica. tion of a temperature 20° of Fahrenheit; and gave only the smallest perceptible traces, by a cold of 0° ora few dez grees below. Icannot help suspecting, therefore, that the moisture, manifested in the earlicr experiments, was derived from the mercury or from some extraeous source, and was not generated by the action of electricity *. The avidity with which ammonia retains moisture, and again absorbs it when artificially dried, is very remarkable, A confined quantity of common air may be completely de. siccated, in the space of afew minutes, by pure patash, or by muriate of lime; so that no icc shall appear in the inner surface af the containing vessel, when exposed to a cold of—26¢ of Fahreuheit. But ammonia requires exposure _ during some hours to potash, to stand the test even of O& Fahrenheit; and a single transfer of the dried gas, through the mercury of a trough in ordinary use, again communicates moisture to it. Muriatic acid gas, freed merely from visible moisture, depositsno water at the tem. perature of 262 Fahrenheit. This is probably owing to its strong affinity for water; for electricity, after the full action of muriate of lime, evolves, as I have lately ascer- tained, about 4 its bulk of hidrogen gas, the recent, mu, riatic acid gas giving about _‘,th after the same treatment +, From * It may be objected, I am aware, that as the gasses produced from ammonia are nearly double its original bulk, they may hold in combination any water that may have been generated by elec- - tricity. But though this supposition may explain the nonappear- ance of visible moisture, it does not account for the inefficiency ' of a powerful cooling cause to discover traces of watery vapour : for this is a test which renders apparent very “minute quantities af water in gasses. won ct Se + In a course of experiments, which I haye described in the Philosophical Transactions for 1800, it appeared that muriatic acid gas, after being dried by muriate of lime, gave nearly as much hidrogen NEW METHOD OF ANALYSING AMMONIA. 361 . » From the average of a great number of experiments on Proportion of — the decomposition of ammonia by electricity, I was ig Seek a some time led to believe, that you had rather understated ammonia, the proportion of permanent gasses obtainable from it by this process, (viz. 108 measures of permanent gas, from 60 of ammonia, or 180 from 100), For the most part, I had found the bulk of ammonia to be doubled by decomposition, even when the gas was previously dried with extreme care, In one instance, a small bit of dricd potash was left in the tube, along with the ammonia, during electrization, with the view of its absorbing water, which I supposed, at that time, to be generated by the process. In this case, 59 meas sures, (each = 10 grains of mercury) became 115. The following table shows the expansion of various quantities of ammonia, Exp. _%. 60 measures of ammonia, gave permanent gas 112 2 60 - = - n ni 120 Nearly doubla 3. 59 (potash being left in the tube) at iw 115 4° 55 - - - - = 115 - 5. 75 (under the pressure af haif an atmosphere) 150 5.) 65... - ~ - = - 130 Fi 1 65 : 3 : - - 130 8. 53 (one of the conductors being of steel wire) 106 —_———. hidrogen by eiectrization, as gas which had not been thus exposed. I.was not however aware, at that time, of the extreme caution necessary in experiments of this kind; and was satished with trans- ferring the acid gas from a Jarge vessel, in which it had been dried, into the electrizing tube, a mode of proceeding which J now find to be quite inadmissible. "The action of muriate of lime, which has undergone fusion, on muriatic acid gas, is rendered very sensible, when considerable quantities are used, by the evolution of much heat, and by a diminution of the volume of ihe gas. Ammonia, also, is contracted in bulk by dry caustic potath. Muriate of lime cannot be employed for its desiccation, since this substance rapidly absorbs the alkaline gas, even when the gas has been previously exposed to quick-lime. In this case, the ammonia attracts a por- tion of muriatic acid from the earthy salt, agreeably to the law of affinity, which has been so ably illustrated by Berthollet. wa and 362 But this pro- hably above the trwtly, Proportions of hidrogen and . nitrogen, Attemptat a shorter method of analysis. NEW METHOD OF ANALYSING AMMONTA. and 492 :°978 : : 100 : 198-78. These proportions, you will find, correspond very nearly with those long ago stated by Berthollet *, who converted 17 measures of ammonia, by electrization, into 33 measuses of permanent gas, which is at the rate of 194 from 100 +. Having lately; however, carried'ou the process with the observance of additional precaution, (the mercury being first boiled in the tube, be- fore admitting the ammonia, and still remaining hot when'the gas was passed up), I have obtained from the alkali less than double its volume of permanent gas, viz. 280 measures from 155, or at the rate of 180°6 from 100. The variable-: ness of the first set of results arises, I believe, from the un- certainty of the quantity of ammonia decomposed. For if: the smallest portion of moistere remain in the tube, a little. ammoniacal gas will be absorbed, and will be slowly given out again as the electrization goes on, thus rendering the actual quantity submitted to experiment greater than ap- pears. It is probable, also, from a fact which I shalt after. ward state, that mercury itself, unless when heated, ma absorb a small portion of alkaline gas. aid The proportion of the hidrogen and nitrogen gasses to each other in the products of ammonia decomposed by electricity, I am satisfied, by recent experiments (June, 1809) is as nearly as. possible what you have determined, viz. 74 measures of hidrogen gas to 26 of nitrogen. The nearest approximation I have made to these numbers is 73°75 to 26°25. Our only methods of analyzing mixtures of these two gasses, (viz. by combustion with a redundancy of oxigen) is not, I believe, sufficiently perfect to afford a nearer coincidence. Tho extreme labour and tediousness of the decomposition of ammonia by electricity influencedme, toattempt the dis~ covery of a shorter and more summary method of analysis. The most obvious one was its decompositihn by oximu~ riatic acid gas; but this plan was abandoned, from the im- possibility of confining both the gasses by any ore fluid 5 since water acts powerfully on the one, and mercury on the * Journal de Physique, 1786, ii, 176. + Berthollet, jun. lately found the mean of a number of expe- riments to be 204 from 100. See the following article. C. other NEW METHOD OF ANALYSING AMMONIA. 863 other. But a mixture of oxigen and ammoniacal gasses A mixture of more*than answered my expectations. When mingled in a iri proper ‘proportions, these gasses, 1 have ascertained, may detonate doven be detonated over mercury by an electric spark; exactly — like a mixture of vital and inflammable air; and the results of the’ process, with due attention to die circumstances, which will soon be stated, afford an easy and precisemethod of analyzing, in the space of a few minutes, considerable quantities of the volatile alkali. With agreater proportion of pure oxigen gas* to ammonia than that of three to one, or of ammonia to oxigen than that of three to 1-4, the mix. ture ceases to be combustible. When the proportions best adapted to inflammation are used, oxigen gas may be diluted with six times its bulk of atindliptieridhd air, without nin its property of burning ammonia. Atmospherical air alone docs not, however, inflame with Atmospherical ammonia, in any proportion that Phave yet tried; though; a poids by long continued electrization with air, sheen is at eae eee length decomposed; its hidrogen uniting with the oxigen of eee cast acy the air and forming water, while the nitrogen of both com- ae gee poses a permanent residuum. Forty-five measures of am- monia being electrified with eighty-six of common air, ‘the total 131 became. 136, and 132 after being washed with wa- ter. Of 17:2 measures of oxigen, contained in the 86 niea- sures of air at the outset, only 2:9 were left; and these also would probably have disappeared by continuing the opera. sion. “If a mixture of ammonia and atmospheric air, each previously dried by caustic potash, and.then electrified, be examined, the production of water is made sufficiently appa- rent on applying ether to the containing vessel.) In subjects ing ammonia, therefore, to this test of the generation’ of water by electricity, the purity of the gas from atmospheric air should be carefully determined +s tz : Wha oe i€ * Containing only, three or four per cent nitrogen gas. tthe The result , ofthis experiment shows, miorcover, that, even supposing oxigen-to be a, constituent of ammonia, we are not to ex- pect its evolution, ina separate form, by electricity ;stmce, when electrified ‘with aysmoniacal gas, oxigen gas is deprived of its elas-, tic form, and its base is condensed into water, by union with Rascent hidrogen evolyed from the alkali. The 364 Froducts of the combustion of NEW METHOD OF ANALYSING AMMONIA. The products of the combustion of ammonia with oxigen ammonia with Vary essentially, according to the proportion of the gasses oxigen vary ac- which are employed. If the oxigen gas exceed considerably cording to the proportion of the gasses. the ammonia (that is, if its volume be double or upwards) the ammonia entirely disappears ; and no gasses remain, but a mixture of nitrogen with the redundant oxigen. The moment the detonation is completed, a dense cloud ap- pears *, and soon afterward settles into a_ white incrusta. tion on the inner surface of the tube, The quantity of this substance, which is produced, is too minute for analysis ; but its characters resemble those of nitrate of ammonia, the acid ingredient of which is probably generated by the action of oxigen on the nitrogen of one part of the volatile alkali. Accordingly, when the excess of oxigen is removed by sul- phuret of lime, the nitrogen generally falls short of the pro- portion, which ought to accrue from a given weight of am- monia; and hence it is scarcely possible to attain, when a considerable excess of oxigen is used, an accurate analysis of the volatile alkali. When, on the contrary, the ammonia exceeds consider. ably the oxigen gas, no production of nitrous acid appears to take place , for the residue, after detonation, is quite free from cloudiness. It is remarkable, however, that ammonia, when fired, in certain proportions, with less oxigen thanis required to saturate its combustible ingredient, is nevertheless completely decomposed. Part of its hidro, ‘gen is sufficient for the saturation of the oxigen; and the remaining hidrogen, and the whole nitrogen of the ammo.- nia, together with that existing as an impurity in the oxigen employed, remain in a gaseous state, and com. pose a mixture, which may be inflamed by adding a se, cond quantity of oxigen gas, and passing an electric * In some cases I have observed, that, when the cloud does not occur immediately, it may be madeto appear by agitating the quick- silver contained in the detonating tube. This is probably owing to the disengagement of some ammonia, which had lodged with the mer- cury. ‘The fact confirms what I have already suggefted respecting the cause of the variable proportion of gasses, evolyed from am- monia by electricity, spark, NEW METHOD OF ANALYSING AMMONIA. spark*. In this way all the hidrogen of the volatile alkali may be saturated with oxigen, and condensed into water ; and the whole of the nitrogen may be obtained as a finat result of the process. After determining the amount of the oxigen, consumed both in the first and second combustions, it is easy to calculate the quantity of hidrogen, in the satu- ration of which it has been employed; for when no nitrous acid has been formed, the hidrogen will be, pretty exactly, double in volume the oxigen which has been expended. ‘These general observations will tend to render the fol- lowing experiments more intelligible. ‘They may be divided into two classes, Ist, those in which ammonia was fired with an excessive proportion of oxigen; and 2dly, those in which the oxigen, used in the first combustion, was insuf- ficient, or barely adequate, to saturate the whole hidrogen of the alkali. I. Decomposition of Ammonia by an Excess of oxigen Gas. 368 Twenty-two measures and a third of ammonia were mixed Ammonia de- with 442 oxigen containing 43 of pure gas. The total 67 COMPO! by, farther diminution, but sulphuret of lime left only 8 mea. sures. Now 34— 8 = 26 show the quantity of oxigen gas, which escaped condensation ; and this, deducted from the original quantity (43) gives 17 measures for the amount of the oxigen expended. The last number 17, being mul. tiplied by 2, gives 34 for the hidrogen apparently cons sumed. The final residue 8 — 1-66 (the nitrogen intro- duced by the oxigen gas) = 6°34 is the nitrogen obtained from 223 of ammonia; and if to this the hidrogen be added, 40-34 measures of permanent gas will be the total result. Hence 100 measures of the gas producible from ammonia should contain 84-29 hidrogen and 15°71 nitrogen; num. * This is analogous to what happens, when ether, alcohol, or any of the aériform compounds of carbon and hidrogen, are ex-_ ploded with a deficient proportion of oxigen; for much of the hidrogen is found in the residuum in the state of gas, and again becomes susceptible of combustion after the addition of a second quantity of oxigen. (See Mr. Cruikshank’s excellent pupers in the 5th Volume of Nicholson's Fournal, 4to.) ‘ Sed ers 2 excess of oxi- became 34 when exploded. Water did not produce any gen. 366 Proportion of hitrogen defective. Ammonia de- composed with a deficiency of exgen. NEW METHOD. OF, ANALYSING AMMONIA, bers too remote from those, which have heen already ass signed, to be considered even as approximations to the truth. The errour arises from the combination of oxigen gen, during combustion, not only with the hidrogen, but with the nitrogen of the alkali, the latter of which conse- quently appears deficient, and the former proportionably in Xcess. s . Frequent repetitions of this combustion, with a considcr- able excess of oxigen gas, continued to give a deficient pro- portion of nitrogen ;. and as no accurate conclusions can be drawn from experiments. of this kind, I shall proceed to those of the second class. a If. Experiments, in which Ammonia was fired with a deficient Proportion of oxigen Gas. Sixty-three measures of ammonia were exploded over mer- cury with 33 of oxigen gas containing one of nitrogen. The totah96, when fired by an electric spark, were diminished — to 57 measures, which were not contracted.any farther by successive agitation with water, and with sulphuret) of lime. The whole of the ammonia, therefore, was decomposed’; and, all the oxigen had entered into combination with the hidrogen, of the alkali... The residuary 57 measures.were mingled with. 40 measures of the same. oxigen gas, and detonated by an electric spark ; after which the total, 97, were reduced :to 60. The diminution, therefore, was 37 measures; and as.two thirds of this number may beascribed to the condensation of hidrogen gas, the residuary 57; must have been composed of 24°66 hidrogen, and 32°34 nitrogen, The oxigen expended, also, was, 32 in the first combustion, - +12:33 in the second = 44°33; and this number, ;being doubled, gives 88-66 for the whole hidrogen saturated, sup= posing it to be in the state of hidrogen gas. . But from the above quantity of nitrogen (32°34 measures) we are to deduct one méasure, with which the.33 measures of oxigen were contaminated; and the remainder 31°34 shows the number of measures of nitrogen, resulting from 63 measures of ammonia. ‘The total amount of gasses obtained is 31°34 -+- 88°66 = 120; and the proportion of the hidrogen by volume to that of the nitrogen, as 73°88 to26:12. | sis oy ee. ‘ NEW. METHOD OF ‘ANALYSING AMMONIA. Yo avoid the tediousness of similar details, I shall state, - in the form of a table, the results of a few experiments out of a number of others, all of which had, as nearly as could be expected, the same tendency. The sixth experi- mentin the table is the one which has been just described. wn és E be laleie | - Bede OO. | Fl OOo ak IN | ee ae Oo 2 ob oe ak ae | g Es 3 o;,olo}lny] eo ee Te TR le ta | ol aA] aR) 3 BPR eR ben TR Es eS. ao) pe fata Fo Sorts 1 eG loca hop) Ic tS. 9. 60 aAEIES | OlOLajto lala coc a om ol _ a a — ask S) ieee n Mw sbi eee cakeh TaN. =) ait Weg. rail Has ihc aoa ae SASS Me HU AiR Loy ferret oe pis) Ko} S nw 683 4 De ee Sis ne Ro se ee te — 3 od wr uw) cq nN [oa] Aas seg Se | | o mY > acd 7 . = s id S38 Peal kein [tial Nise As (SP MPS sins O iS Eu io) Re) oO me ae — foal Sad | nex 0 ape [x |e ‘ Ss ~pPwre lata la t= moO s = 2) ~ Po) oD = eau oe : aE Se las | oO Or! 64 | vEgS mm | OQ [S) ~jiwt io Sag & a) = 4 m1 ar fpojl wa fomie oa 367 Tabulated re- ‘ From an attentive examination of the foregoing fable, it Remarks. ‘will appear, that the results are not perfectly uniform, though perhaps as much as can be expected from the nature of the experiments. ‘Thus the proportion of permanent gasses to the ammonia decomposed (the nitrogen being actually measured, and the hidrogen estimated by doubling ‘the oxigen expended) may be observed to differ consider- 4 ’ ably 368 Proportions of hidrogen and nitrogen. NEW METHOD OF ANALYSING AMMONIA. ably ; the highest product being 1981, and the lowest 180-2, from 100 of ammonia. There can scarcely be a doubt, however, that this want of coincidence is owing to the same cause, as that which I have already assigned for the variable proportions of permanent gas, which are obtained from equal quantities of ammonia by electrization. And, ac» cordingly, I have found, that the evolved gasses, aS aS= certained by combustion, bear the smallest proportion to the ammonia, when most pains have been taken to obviate the presence of moisture. ‘The lowest number, therefore, is to be assumed as most correct; but other cireumstances being considered, I believe the second experiment furnishes the most accurate data for determining the composition of ammonia. The same explanation will apply to the different proportions of oxigen gas required for the saturation of 100 measures of ammonia, the variation no doubt arising from the uncertainty of the quantity of alkaline gas which is actually burned. The proportion of oxigen to ammonia, which I believe to be nearest the truth, and most precisely necessary for mutual saturation, is that resulting from the second experiment, viz. 671 measures of oxigen gas to 100 of ammonia, or 100 of the former to 148 of the latter. It may be observed, also, by comparing the numbers in the last two columns of the table, that the hidrogen and nitrogen gasses do not uniformly bear the same proportions to each other. Notwithstanding all the labour I have be- stowed on the subject, I have not been able. to obtain a nearer correspondence, owing most probably to the im. perfection of the mode of analysing a mixture of hidrogen- and nitrogen gasses. In the mixture of permanent gasses, determined in this way, the hidrogen, it may be remarked, bears generally rather a less ratio than that of 74 to 26. I do not, however, consider this fact as contradicting the accuracy of the proportions which you have assigned; and. it appears to me, that a sufficient reason may be given for the want of a more perfect coincidence between results, obtained by such different methods of investigation. In the products of the electrization of ammonia, the hidrogen composes nearly three fourths of the mixture; and hence . ‘ its ~ NEW METHOD OF ANALYSING AMMONIAs 869. its combustion by oxigen gas is likely to be completely effected, and the whole of the hidrogen condensed into water. But after the partial combustion of ammonia by oxigen gas, a residuum is left of hidrogen and nitrogen ga$ses, of which the hidrogen usually composes less, and sometimes considerably less, than one half the bulk. In this case it may be suspected, that a small quantity of hidrogen occasionally escapes being burned; and whenever this happens, its proportion to the nitrogen will appear to be Jess than the true one*. ! From the inflammability of a mixture of ammonia with Ammonia sus- oxigen gas, it was natural to expect, that this alkali would od prove susceptible of slow combustion. By means of a pecu- with oxigen. liar apparatus (on a plan which I have described in the Philosophical Transactions for 1808, part II +, but ona smaller scale, and with the substitution of mercury for water), I have found that ammonia, expelled from the orifice of a small steel burner, may be kindled by electricity in a vessel of oxigen gas; and that it is slowly consumed with a pale yellow flame. The combustion, however, is not sufficiently vivid to render the process of any use in the ans alysis of ammonia. : With nitrous oxide (containing only 5 per cent impurity) mixture of am- ammonia forms a mixture which is extremely combustible. hone sc = If the nitrous oxide be in excess, the proportions have a tremely com- considerable range; for any mixture may be fired by bustible. electricity, of which the ammonia is not less than one sixth of the whole. The combustion is followed by a dense cloud, sometimes of an orange colour. When the nitrous oxide greatly exceeds the ammonia, (as in the proportion, for example, of 100 to 30) there is little or no diminution after firing: and the residuum is composed of a small por. * This consideration suggests. the propriety of using no more oxigen in the first combustion of ammonia, than is barely sufficient — to inflame it; or if a larger quantity has been used than is required for this purpose, and a residue consequently obtained, of which the hidrogen forms only a small proportion, it is proper to add a farther quantity of hidrogen, before the second combustion. An allowance may afterward be made for this addition, + See Journal, vol. xxii, p. 83. Vor, XXIV.—SuppremMenT, 9B tion 370 Results of an experiment. Explanation of it. Confirms the former analysis. NEW METHOD OF ANALYSING AMMONIA. tion of undecomposed oxide, some oxigen gas, and a con. siderable quantity of nitrogen, the last of which, however, is not in its full proportion. When the nitrous oxide is farther increased, still mose oxigen is found in the residuum. When, on the contrary, the alkaline gas is redundant, combustion does: not take place, unless the nitrous oxide forms one third of the mixture. A little diminution takes. place on firing, but no cloudiness is observed; and the re- sidue is composed of hidrogen and nitrogen gasses, with occasionally a small portion of undecomposed ammonia. As an example of what takes place, I select the following experiment from several others. A mixture of 41 measures of ammonia with 40 of nitrous oxide (= 38 pure), in all 81 measures, were reduced by combustion to 75, which were found to consist of 16 hidrogen and 59 nitrogen gasses. To explain this experiment, we may assume (as is consistent with your own analysis *) that 100 measures of nitrous oxide are equivalent to 52 measures of oxigen gas and 103 of nitrogen. The oxigen in 38 measures of nitrous oxide will, therefore be 19-7, to which, when the oxigen spent in burning the residuum (viz. 8m.) is added, we obtain 27:7 for the total oxigen consumed; and multiplying by 2, we have 55°4 for the hidrogen saturated. From the residuary nitrogen (59) de- duct 39 measures arising from the decomposition of the ni- trous oxide ++ 2m. mingled with it as an impurity = 41, and the remainder, 18 measures, is the nitrogen resulting from the volatile alkali; and as 41 measures of ammonia give 55:4 + 18 = 73:4 measures of permanent gas, 100 would give 179 measures, in which the hidrogen and nitrogen would exist in the proportion of 75:4 to 24°6. From the same facts it may be deduced, that 100 measures of ammonia require for saturation 130 of nitrous oxide = 672 oxigen gas. The coincideuce then, between the results of the com- bustion of ammonia with nitrous oxide, and those with oxigen gas, confirms the accuracy of both methods of an. alysis. * Researches, Res. ii, Div. 1, or Thomson’s System of Che- mistry, 3d. edit. ii, 143. Nitrous NEW METHOD OF ANALYSING AMMONIA. Sik Nitrous gas, which, it appears from your testimony *, Proportions for does not compose an inflammable mixture with hidrogen, ae (nor, ‘as I am assured by Mr. Dalton, with any of the vae rieties; of carburetted hidrogen) may be employed, I find, for the combustion of ammonia. ‘The proportions euanived for mutual saturation are about 120 measures of nitrous gas +0 100 of ammonia. An excess of the former gas does not give accurate results; since not only the hidrogen of the ammonia, but some of its nitrogen is also condensed ; and the mixture, after being fired, exhibits the cloudy appearance usual in that case. Forty-eightmeasures of ammonia, being fired with 60 Results of nitrous gas, (= 53 pure) both gasses were completely de- pi Ses = composed; and a residue left consisting of 61 nitrogen and 9 hidrogen. Sixty measures of ammonia and 41 nitrous gas (= 36-1 pure) gave, after firing, a mixture composed of 10 ammonia, 531 nitrogen, and 301 hidrogen. But taking for granted that 100 measures of nitrous gas, according to your analysis, hold in combination a quantity of oxigen equal to 574 measures of oxigen gas, and of nitrogen equal to 484 measures; and assuming the proportions of the nitrogen and hidrogen in ammonia, to be those established by your experiments and my own: it will appear from an easy calculation, that the proportion of nitrogen, in the above residua, a little exceeds, and that of the hidrogen rather falls short of what might have been expected. I have not — yet been able to reconcile these differences by the numerous trials required ina process of ‘so much delicacy; and I re« serve the inquiry for a season of more leisure. The fore going statement I wish to be considered as merely announcing the general fact of the combustibility of a mixture of ammo~ nia and nitrous gas, a property which chiefly derives ims portance from its being capable of application to a new method of analysing the latter. eee Before concluding this letter, I shall briefly state the re- Effects of sults of some experiments, which I have lately made in con- °!¢: : “et orem ott 0 esse wads shia a OR amar ae | ag wetibel tags BE 08 st 2 h-apednwetat W $ } seat pak ee san el Yo ahead? og eee re AY - aie” 02: Aitid, oaetajowW 2 ihoo Bn ae eretwello We EMR ae Roiteaivi ), bao W. kl Saeaboo'W cath a: pata) Tse ie tne ona ‘Kites suse feats 20 ue srioupiel Gat -yaeteta visepgem Ce a ae yen rahisi:.- lng +. ee ign! 4, ier : 198 gt wil Fiabe : i’ eli steal woe , Eade te aa ; ; Dae en Be i mnoneetes Ss tt ile Aegan oe y eo en ir 4 Taodder artis , f oles e nibh: ‘iroas ‘es eee pat ¢ e. “AS eye me; ¥ ei. beagle Log Bite es He ere psere f t eet. * oe Com H tisbes eebert ters His+ Pater . +4 334 38. esta iesseres eeGves ant boone beets 2%. “ i > 13% . tet owe bgresessatea! iisttisekesssetectoesesesey ats Seeseeretins sesoletecesersezears endabens aehete; rb igt eee ee Sb ttessrerescrtssese: ; sates tts $5 pe heeetstel Sees - , : 8 is: