Papurau Newydd Cymru

Chwiliwch 15 miliwn o erthyglau papurau newydd Cymru

Cuddio Rhestr Erthyglau

7 erthygl ar y dudalen hon

GOLD AND SILVER IN PEMBROKESHIRE.

Newyddion
Dyfynnu
Rhannu

GOLD AND SILVER IN PEMBROKESHIRE. TO THE EDITOR OF THE "WELSHMAN. J 1 Jl b comparea to Lne SIR,—The field of science may be compared to tne mleajring of a primeval forest, in which, as the reclaimed eatIng of a prImeval forest, In w d f th t k area increases. the greater the magnitude of the task ?Ppears, and the same may be said of scientific research In a new and somewhat unknown field of discovery the more a researcher prosecutes his investigations greater difficulties and a larger field are presented to him. 1 No one will, I think, doubt that the geological for- mation of Pembrokeshire presents a field which, if sub- jected to a systematic and scientific exploration, may produce rich harvests of knowledge and wealth. It has already contributed its share of coal and iron towards the establishment of the steam-engine and the other 'Wonderful inventions by which we have been enabled 'to keep pace with other places now triumphing over time and space, and I cherish the hope that the time is not far distant when research and industry will be rewarded by the development of other minerals besides those already discovered, and actively worked in the Vicinity of our homes. Your Scientific readers have already been gratified by the announcement in your columns, and other local contemporaries, of the discovery by Mr William Glan- ville of the precious metals in the geological formation of this county, and with a feeling of national pride must be anxious to afford him every encouragement in the prosecution of his pursuits, by wishing him success and ample remuneration for his labour. It is unfor- tunate, however, that Mr Glanville has not completed his discovery, as he has somewhat prematurely (I use toe term because he has as yet failed to establish the fact) given publicity to the statement that he has found gold in the form of an argillaceous oxide (a form hitherto, I believe, unknown to any other tyro), by which he has been submitted to the annoyance of a public controversy. This discovery, if established, would prove of very great sci- entific importance, as upsetting the opinions of many of our eminent philosophers. I have with all the respect due to Mr Glanville's efforts ven- tured to discuss some of the points which ap- peared to me of doubtful accuracy. The object of this discussion should be to elicit truth not victory, and I am pained to think that Mr Glanville should have construed my former letter into a desire for ostentation. I considered that from Mr Glanville adopting the press to ventilate his supposed discovery, it would be the proper. channel for any person to dis- cuss it in, particularly as Mr Glanville would not entertain private communications touching the subject. In justice to myself, therefore, I shall feel grateful if you will grant me space for a reply to Mr Glanville's letter of yesterday, the 26th inst. In doing so, I must from good taste refrain from noticing anything in the shape of abusive or insinuative personalities, or subjects irrelevant to the question under discussion. The prin- ciple of "Ego de aliis loquor tu, de cepes responded," will never bring us to anything definite in the matter. Mr Glanville cannot bold me responsible for typogra- phical errors any mure than I can him for the following paragraph, in the Pembroke Dock Gazette, of January 21st: We have to announce that Mr William Glanville, of New House, near Narberth, and formerly merchant in Pembroke Dock, (father of Mr Wilfred Glanville, morchant, of this town) has discovered gold on land near New House. 0 He is in partnership with a gentleman from '-wan??& workmg the ground, and has twelve n.? in big em-  for tfct,   have mentioned the name of thi 8 paper, with that of the Camb,-ia Daily Lead111 n3y former letter.  ba?whe? ?? ?  calling attention to the fact tbS «whp-°  metal dissolved in the same kind of acid ta'L nd P?Pl-tat.d with the same kind of preci- Pitant te ?8nlt of quantitative and qualitative wSS rd. ^lfffere?, t to what it is when an oxide of the metal fa so employed, and consequently the symbols 4L'nd formula must differ as well in each such ca?-To Mia I take exception. .The   dmit will be different, but the results wiU^idS^ ??.P?-let gold be dissolved in A?? ua??-'J? solution will contain a chloride of gold. Again, let oxide of gold be dissolved in the same acid the solution will also be a chloride of gold (w?h ?he addition in this case of a molecule of water formed. If these solutions be now treated with ferrous sulphate, the resulting precipitates will be identical. A reference to any modern work on chemistry will bear me out in this. Mr Glanville says, I should not hold him respon- si. ble for stating that gold and its oxides are only soluble In free chlorine and bromine." This I certainly do not, and never pretended to. I am prepared to take the probandi of that statement upon myself. Mr Glan- ville then confesses" his ignorance as to bromine being IA solvent of gold, and says, that Mr Saer must know thnf aqua regia, aqueous chlorine, oxygenated chlorine, does he °"? chloric acid in the last instance ?) and eVn chromic acid added to muriatic will dissolve gold." This I do know, but it is the free or liberated chlorine that acts upon the metal in each instance, and whether gold or its oxide be treated with nitro hydro-chloric chloro-chromio, hydrobromic or hydrochloric acids as solvents, the radical elements constitute the solution and chlorides or bromides will be the product in each case. If Mr Glanville will once more take the trouble of referring to any good work on chemistry, he will find it stated by other authorities" than me Miller, vol. 4, page 1051, None of the oxygen acids except selenic have any action upon it, but it is readily 'attacked by any mixture of chlorine Naquet, page 268: Chlorine and bromine act upon it even cold." Mr Glanville says, Mr Saer does not tell us whether this wonderful result (of his formula expressing the reaction) is from gold, from gold and oxide, or from oxide of gold alone." To this I reply that it would not signify how the chloride solution is formed, whether from dissolving gold, gold and oxide, or oxide alone in aqua regia, a chloride of gold in solution is the result in either case (with, in the case of the oxide, the formation of a molecule of water), and the precipitate from this solution by ferrous sulphate will be metallic gold, with a ferric sulphate in solution, and I challenge him to prove to the contrary. Mr Glanville, to prove the incorrectness of this result, copies from the London Encyclopedia, under the head- ing of gold, that The precipitate of gold obtained from (solution) in aqua regia (the precipitant is not given, but as it is to prove the incorrectness of my statement, I assume it is ferrous sulphate), appears to be a true oxide, soluble in the sulphuric, nitric and muriatic acids." Now, with Mr Glanville's permission, I will copy from the following authors to prove the incorrect- ness of the London Encyclopsedia Miller's chemistry, vol. ii., page 1051 :-A solution of sulphate of iron is next prepared and added to the solution of chloride of gold, metallic gold is thus pre- cipitated in the form of a finely divided powder. Naquet's chemistry (by Stevenson and Cortis), page 269 :-Reducing bodies such as the protosalts of iron, decompose the chloride solution, liberating the metal. Fownes's chemistry (by Jones and Watts), page 419: —Pure gold is obtained by precipitation from solution in aqua regia with a ferrous salt, which reduces the gold and becomes itself converted into a ferric salt. Each of these authors also state that gold and its oxides are insoluble in oxygen acids, even hydro-fluoric has no action upon them. Strong sulphuric and nitric acid take up the oxides, but there is no true salt formed, the oxides separating again on dilution or exposure to light. On the other hand, gold is easily attacked by bromine or chlorine when cold, and its oxides are readily dissolved by hydro chloric and hydro bromic acids. Mr Glanville says, If I were to dissolve gold in either of the acids that will dissolve it, and use as my precipitant sulphate of iron, metallic gold and sulphur would be precipitated. If I were to do the same with an oxide of gold, I should get a metallic oxide of gold and sulphur precipitated. When an oxide is dissolved in an acid, it unites in that acid, forming a salt, but when sulphate of iron is used to precipitate an oxide of gold in solution, the oxide of iron unites with the acid, and the metallic oxides of gold and sulphur are preci- pitated." This statement of Mr Glanville's is an utter confusion. Where is he to have his oxide of gold from in a chloride solution for instance, and what is a metallic oxide of Sulphur ? Is it sulphurous acid or sulphuric he means P <SPuliphu ur is a non-metallic element. It is true that in treating an element like copper which will combine with oxygen acids an atom of hydrogen would be displaced and a basic salt formed, but with gold the case is different. Mr Glanville should know that in dissolving gold in aqua regia no oxidation takes place, it is simply a union with the liberated chlorine, this may be proved by suspending gold leaf in a jar of chlorine gas. I have since writing my former letter performed a series of experiments with great care upon this subject, and in no instance had I results differing from those of recognised authors. Mr Glanville next qnotes from an article on gold in a book which he has, Sulphurets precipitate gold from its solvents the alkali uniting with the acid and the gold falling down combined with sulphur. It should be borne in mind that it is not a salt is formed when gold or its oxide is precipitated by sulphate of iron." It is known that sulphurets of the alkaline metals precipitate gold from solution, and it is known also that they possess the power of holding an appreciable quantity in solution, but I was certainly not aware until now that sulphur combined with alkalies. I have learnt that it combines with the metals forming Bulphurets or sulphides. When sulphate of iron (rather different from the sulphide) is added to a solution of gold, totally different reactions are produced as explained above. I would here remind Mr Glanville, that all the ave., wou metals proper are insoluble. SUhlS 011 tkS would he deny that the oxides of the metals may not be in that absolutely free state the metals may n th r" To this I say no but if intimately blended together. To this I say no but it would then be a mechanical mixture not an alloy. I quote from Mathiesen on alloys, onionsi o one metal in another which has become ????°??.?- ness sake, solidified solutions of one metal in the other." f fusion I shall make 0tWith regard to the question of fusion, I shall no further ob83rvations upon Mr Glanvil e than to quote from Miller, Vol. 2, page 827, The inter- mixture of lime, Magnesia, or oxide of iron in any con- siderable quantity with the clay (silicate of alumina), increases its fusibility and diminishes its plasticity." Muspratt, vol. 1, page 281, From the well known infusibility of this substance, it is evident that mere exposure to the strongest heat of a blast furnace with- out the addition of a flux would be of no use, for although the gold would be melted, it would remain in the mttss and no separation of the precious metal would take place. It is therefore necessary to add some substance which at a high tempera- ture shall combine with the quartz (silica) and produce a fusible compound, in which case the gold, especially if combined with some other heavy metal, will in virtue of its high specific gravity fall to the bottom of the vessel. Lime therefore aided by the addition of oxide of iron is usually em- ployed for this purpose, lime alone or lime and clay in equal proportions will combine at a high temperature producing a fusible nlag with quartz through which the gold also in a melted state tends to sink to the bottom of the furnace." This operation the author proceeds to say is again materially assisted by adding another metal which shall combine with and absorb the whole of the gold, from which it can afterwards be separated, some metal, in short, which shall serve the same pur- pose at a high heat as mercury does at an ordinary temperature. Of all metals lead appears to be the best adapted for this purpose as the gold can be easily separated from it by cupellation." It cannot be necessary to remind Mr Glanville, that the extreme temperature alluded to in his letter, is not required for this process. The metamorphosis of gold, by lime precipitation, may be easily explained by the trivalent properties of the metal referred to in my former letter. I would beg Mr Glanville's permission to again state my belief that definite results cannot be obtained unless such experi- ments as these have been performed with pure reagents and on philosophic principles. How can Mr Glanville explain away the synonimous meanings of the terms Oxygenation and Oxidation- when I tell him that Oxygenated water is now more properly called peroxide of hydrogen, the more obsolete term being abandoned P Can chemical union with oxygen take place without oxidation ? Following the example of my contemporary, I shall now retire from the field, leaving to your chemical readers the conclusions derivable from this Controversy, and in doing so, I beg to draw their attention to a series of lectures on Chemical Geology, delivered at the School of Mines, reported in the Chemical News, by Dr Percy, in 1864, and to an interesting paper in the Scientific Opinion of December 16th, 1868, from Pro- fessor Wurtz, on The origin of gold," in which the opinions of Sterry Hunt, "On the Californian and Nova Scotian gold fields," and Sir Roderick Murchison, On the Silurian systems," are fully discussed. All these authors, though differing in opinion as to gold genesis, show that it does not and cannot exist in nature as an oxide, in consequence of its proneness to deoxidation. With due deference to Mr Glanville, surely he cannot consider himself infallible, and of superior authority to such researchers as those, but it is true time will obliterate speculative opinions, but confirm the correctness of nature." I am, sir, Your obedient servant, DAVID P. SAER, Ph. C. Pembroke Student St. Mary's Hospital, London. Pembroke Dock, Feb. 27th, 18G9.

IA FRENCH VIEW OF OPEN-AIR…

AMERICAN FEELING ON THE RECENTI…

THE CONTENT CASE. I

IDR. PUSEY ON THE FINAL COURT…

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