TS 670 .H56 ^ i u'jKifliiSiriuitffli MBB F mii " ih " 5 OHIO MtMVIfmWwMi ■mRBPSS fimmflf THE JEWELER'S HAND-BOOK, CONTAINING THIRTY PRACTICAL METHODS TOR (Salfampg, €hdxa plating anb Cfllormg WITH GOLD, SILVER, AND COPPER, ©n all fetalis of petals, WITHO UT ANY APPARATUS, AND B Y MEANS OF INGLE AND COMBINED ELEMENTS OR BATTERIES, WITH AN EXTRA CHAPTER SHOWP ^ THE RECOVERY OF THE GOLD AND SxLVER. Practically demonstrated and embellished with Six Engravings, BY PROF. RUDOLPH HERB, OF ALBANY. WITH AN APPENDING REGISTER OP BUSINESS CARDS OF THE BEST AND MOST RECOMMENDABLE WHOLESALE AND MANUFACTURING FIRMS Of Watches, Jewelry, Clocks, Silyer and Plated Wares, Ac. ALBANY: J. MUNSELL, 78 STATE STREET 1855, 4*i *■. Entered according to Act of Congress, in the year 1855, by RUDOLPH HERR, - In the Office of the Clerk of the District Court of the United States, in and for the Northern District of New York. 1 ,rf TO THE PUBLIC. y£ By presenting this little book to the public we pur- ported to publish the result of our practical observa- tions and experiments for the benefit of the public in general and the trade. We do not claim the privilege of having discovered the origin of the Electro-Galvanic power, but beg to state that we have since its first lotice, 1840, closely followed its progress by experi- menting most of the proposed methods, to assume the responsibility of an opinion as to their particular value in a practical point of view. Simultaneous with the accounts of the first experi- ments of the theory of mating the galvanic agent a conveyance of transporting dissolved metals, we be- friended us with the idea of what incalculable import- ance a practical method, fully competent to meet all demands of the market, would prove; especially as * TO THE PUBLIC. we always cherished the hope that, sooner or later, a process would be discovered to substitute the old school practice of Fire Gilding. Previous to the discovery of the wonders produced by the Voltaic Column, the trade was possessed of certain mediums to effect gilding by boiling metallic articles in gold containing chemical combinations, but as those manipulations did not satisfy the critical taste of the public, consequently, the trade had to fall back upon the old practice, which was based on no science, but on mere mechanical tricks, the property of some expert practitioners, who by this means mono- polized a profession supported by insignificant secrets. As, in the course of time, several publications rela- tive to the progress of the Electro-Galvanic experi- ments attracted the attention of eminent philosophers, remarkable new phenomena were added to the original, all of which conclusively led to the belief, that science combined with energy, would soon find an instrument adequate to the theory, to. produce with certainty, by following strict rules, an efficient result. As a matter of course, every experiment showed a different appa- ratus, and every operation different proceedings, to obtain the desired result. We have therefore spared TO THE PUBLIC. neither time nor money, and subjected those methods standing best recommended to the closest examination, a synopsis of which will be found in the different parts of this book, and have occasionally pointed out certain operations, which we thought proper to patronize, but in all cases have only favored such as will come handy to the practical mechanic. Many were the complaints made to us by persons connected with the profession of Galvanic plating, that their operations varied so much, that no uniform work was to be obtained, and some (probably entirely disappointed) went so far as to call the greatest disco- very of the age, a consummate humbug. To the former we would say, that they will attain thrir purpose, if they will but adhere to the strict laws of Galvanism, as laid down in the course of this book; and to those, who so indiscriminately condemned a theory recognized by the whole world, we should intimate, that, if some attention was paid to the details of our experiments and a new and fair trial afterwards granted to their apparatus, we warrant a change of opinion. We are not enough of an egotist as to pretend to be the only individual fully acquainted with the prin- ° TO THE PUBLIC. ciples of Galvanism, as all our knowledge is derived from hundreds of experiments, until we arrived at a point to form a decided opinion, which we took leave to promulgate before the public in this limited number of pages. We say once more^if your results should not prove equal with our accounts, do not despair of final success, as the causes of your disappointment are often trifling, which, by an attentive perusal of these pages, can be detected and removed. We conclude our introduction by wishing, that the reader might consider this pamphlet a guide to his operations, as then the aim of our fondest hope is realized, and the highest testimony allowed to our feeble efforts. Placing our readiness to answer all inquiries in reference to further information, at the disposal of the reader, we respectfully commit these pages to the kind judgment of the public. The Author. JLlbany., March, 1855. INDEX Preface, Page 3 PART L Chapter I. To gild by the single constant chain . . " 9 " II. To silver by the single constant chain " 22 M III. To deposit copper by the single constant chain " 26 PART II. Chapter I. Gilding By contact and without any Apparatus „ " 28 " II. To silver without apparatus " 31 " III To deposit copper by contact and with- out apparatus " 34 PART III. Chapter I. To gild by the co-operative of combined Elements or Batteries ■ 35* " II. Silvering by means of Batteries " 60 " III. Coppering by galvanic Batteries-. " 6Z 8 INDEX. PART IV. Chapter I. Practical use of the sulphate of copper Battery Page 64 " II. The protected sulphate of copper Battery " 71 " III. The combined protected sulphate of copper Battery " 74 " IV. Grove's Battery " 77 " V. Smee's Battery " 86 •* VI. Coloring of gold, (galvanic alloy.).... " 94 Appendix. To regain gold or silver from solutions. " 96 Conclusion " 100 Advertisements " 103 JEWELER'S HAND-BOOK. PART I. To deposit Gold, Silver, or Copper, upon any me- tallic Surface, under the co-operation of galvanic Elements. CHAPTER L Under this head we i d to treat upon the three following methods: 1st. To gild by the single constant chain. 2d. To gild by contact, and without any apparatus. 3d. To gild by means of combined elements, or with so called Batteries. It will be unnecessary to tire our reader with a vo- luminous theory of the origin or substance of the above named agents, serviceable to obtain a good golden sur- face, as those acquainted with physics already know sufficiently their several constructions, and those de- sirous of becoming acquainted with this important discovery will find satisfactory explanation when we treat of the synopsis of these three methods. 2 10 jeweler's hand-book. The merit of the discovery is due to Prof. De La Rive, of Geneva (Switzerland), who rendered the first account of his practical' experiments in 1840, and as his endeavors were chiefly devoted to method No. 1, we shall not hesitate any longer to subject the result of his labors to our present definition. He used some animal bladder for the purpose which was filled with a solution of gold in aqua regia (aqua regra is a combination of one part nitric acid and two parts muriatic acid), very much thinned with rain or distilled water. This bladder was suspended into a glass jar of suffi- cient capacity to hold it, and this jar contained water acidulated with five or six drops of sulphuric acid. In this water a circular plate of bright zinc, to which a silver or platina wire is fastened sufficiently long to reach into the solution contained in the blad- der, was deposited, and with this wire the article to be gilded was most intimately connected. By this manipulation the article fastened to the wire acts as the negative pole, and the zinc in the acidulated water is the positive pole, and both poles united by the wire form an element and consequently create electric activity and this electric life is termed Galvanism. Although this element or single chain produces a very weak galvanic current, it effects a deposition of a sufficient quantity of gold upon the metallic article fixed to the wire. JEWELERS HAND-BOOK. 11 The stream dismembering the dissolved gold of its connection with the acids and deposits it upon the object at the upper end of the wire, meanwhile the zinc decomposes the liquid matter in the jar. A matter of the highest importance in every respect, is a most scrupulous cleanliness of the article to be gilded. The same must be free of all dust and oxid, and be cleaned to this end with some sour water (mixed with cream of tartar) as the success of the operation is entirely dependent upon the clean and bright surface of the article. It was then brought into contact with the gold solution for about two minutes and at the end of that time it appeared covered with gold. It was then taken out and dried with some fine linen rags, and this operation repeated until the golden layer was of sufficient strength. The gold thrown down by this galvanic agent was of a very soft description, and showed a very high yellow color, almost too rich, as for durability, it was fuliy qualified to stand finishing, but to amend the color the ordinary expedients could not be used, as the different layers of the gold did not adhere firm enough and could consequently not bear the test of jewelers' colors. By this means silver and brass could be gilded; other metals require a different preparation. The following is an outlinp of such an element; 12 jeweler's hand-book. No. 1. A The jar. B The bladder. C The zinc. D The wire. E 4 pieces of wood fixed to the hoop to hold the bladder upon the border of the jar. Mr. De La Rive found it to be a great promotion towards creating electricity, if the zinc was amalga- mated with quicksilver, which can be effected by rinsing the zinc in a solution of thirty parts of water and one part of sulphuric acid, and then brush it with quicksilver. All other metals, such as zinc, tin, German silver, iron, steel, and bronze, must be covered with copper, before any gold can be deposited. We have framed another chapter for the prepara- tion and use of copper solutions, and refer the reader's patience to that part of this book. 13* If we rest one moment to examine the history of Mr. De La Rive's discovery, we are astonished at the rapid and successful progress of the experiments of others who undertook to explore this invention for the- benefit of commerce and science. Messrs. Elkington and De Ruolz, deserve due men- tion, as we owe to their exertions several new and most interesting features relative to electro-galvaniG experiments. The aforenamed gentlemen attracted byRrof. De La Rive's publication of his "notice sur un pro cede electro-chimique ayant pour objel de dorer Pargent et le laiton" have added such perfections to the original idea, as to make it a safe instrument in the* hands of every mechanic, and practically to substitute' the an* cient manner of fire-gilding (gold dissolved in quick- silver). The scientific treatises of Messrs. Elkington and -De Ruolz show a connection of cyanide of potassium (fusse and granulated) to absorb the gold in aqua regia, a most useful stimulus to effect a stronger deposition. It cannot be denied that by the addition of this chemical and poisonous salt, an advantage of the greatest consequence has been gained, as we shall take occasion to define in the proper chapter. But on the other hand a great many obstacles have come to light until the actual proportion of the cyanide was ascertained. It is a matter of every day occurrence that a gilded article will be found covered 14 with a brown surface, or spots, and therefore we have made the object of this book a preventive against all difficulties, by introducing proper rules of proceeding. We shall now abstain from reciting any more of the history of experiments of eminent chemists and give to our readers a practical prescription for a good gold solution, with the apparatus necessary to trans- port its contents. Two dwts. of gold at least twenty-two carats fine, rolled out as thin as possible and cut or torn in very small pieces. This gold must be collected in some strong fire proof porcelain vessel containing one and a half ounces of aqua regia (nitric and muriatic acids), and evaporate the contents over a spirit lamp guarding against any over boiling. As soon as all free acids have evaporated and no- thing of the liquor is left but the gold chloride, a solution of cyanide of potassium (three-fourths of an ounce cyanide dissolved in half a pint rain water) will be added and the whole of the mixture poured into a glass vessel where it shall be kept. It would be advisable at such operations to avoid the vapor of particularly the cyanide as the effects of it operate very injuriously upon the brains. The so prepared solution does not require any fur- ther handling and is fully ready for use. We are now about to describe an apparatus best suited as a single element (constant chain) to deposit dissolved metals upon other metals. jeweler's hand-book. 15 We tried most of the known single constant chains, but none afforded more convenience than the one we are about to delineate, and to facilitate its construc- tion we give a correct drawing in addition. No. 2. A A A square box of oak wood well varnished, the size of which must be according to the articles to be operated upon. At the bottom of the same will be seen a copper bar (B), which must be fastened water tight, and ascends two inches inside the box, leaving a tail of half inch to communicate with the channel, D. This bar bears, inside of the box, a grate of copper sheet or copper wire, upon which a cast zinc plate (H) rests. This box is fixed to a strong board (C), in which the channel (D) is perceptible — and this channel connects with a small cavity (C) on the other end. This channel is filled with quicksilver, through which a thin copper wire, marked with little points, is laid to effect an intimate connection between B and E, strong copper staffs. From the cavity (C) the staff E arises, bearing a hori- zontal and moveable arm (F) , likewise of coppe*. to which 16 the articles to be galvanized are suspended by means of platina or strongly gilt copper wire. G A smaller box, destined to receive the gold solution, is made of oak wood, the size of which is made proportionate with the exterior box, leaving a space of one and a half inches, to avoid contact with the outer apparatus. The bottom of this box is hermetically closed by a bottom of bladder or parchment, G'. Four wooden arms (G") support the in- ner box, which must be kept at a distance of at least one inch from the zinc plate (H), and could be still further distanced by pushing small blocks under the supporters. The bladder or parchment can always be kept in good shape, by drawing strings across the bottom (G'), forming little squares. I Is a spout to let out the liquid from box A, when the work is done. Our readers will perceive that articles of very large size could be gilded by this apparatus, and the same always be kept in good working order when box A is promptly emptied and occasionally revarnished and in case the bottom G' should get a hole by accident, a small piece of bladder when moist pressed upon the hole will repair the damage, but such repair will never be required if said bottom is cleaned with clear water after use, and then dried in a not over warm room.. It will be of moment to select the bars of tolerable strength particularly E and B as it will be a prevents ive against any obstruction of the galvanic current. The ends of E and B must be well amalgamated where they communicate with the quicksilver, as well as the wire in the channel £. jeweler's hand-book. 17 The size of the zinc plate ought to correspond with the object to be galvanized and must be likewise amalgamated. Having described the apparatus and the solution we shall now describe the actual process of gilding. If the channel is filled with quicksilver, the plate of zinc is deposited upon the grate, the box G is filled with a solution of salt water(one gallon water one-half pound salt): then the smaller box containing the gold solution is suspended into the larger one, so that the solution of gold inside forms a level with the salt water outside, to prevent any hydrostatic pressure. The object is then surrounded with platina or gilt copper wire and suspended to arm F in a horizontal position avoiding contact with the sides of the box. The article remains one or two minutes in the appar- atus and is then taken out, when it will show a slight coating of gold: it must then be cleaned with rain water and cream of tartar and the same operation be repeated until the color of the gold satisfies the ope- rator. Every additional operation efTects a new layer, and of course an addition in weight and by this means one will be able to exhaust the solution "ad libitum." Every article so gilded stands the strongest of jewel- er's color and the hardest process of polishing. We had occasion to observe the validity of this process in factories where buttons and plates after being gilded by this apparatus were pressed into various shapes 18 jeweler's hand-book. without sustaining any injury as regards their golden appearance. Round objects such as goblets must be turned several times, as the side nearest to the zinc plate generally takes most of the gold. When left long in the solution things will appear brown, but cream of tartar readily cleans them and polishing will remove the remainder of this brown surface. As the gilding is effected by a liquid it pen- etrates and deposits its metals in places which could not be gilded by the process of fire plating. The practical value of the method will be made apparent as every object gilded by this element when polished is ready for the market and no coloring or gilt waxing is wanted. The gold is so strong as to stand the test of the strong French color, composed of alum, saltpetre and cooking salt, without injury. If it is desired that only certain parts should take the gold, for instance, the inside of a goblet or cup, the rest of it must be covered with an indissoluble sub- stance a prescription of which we have here annexed. Five pounds of common brown amber must be warmed over a slow charcoal fire until it becomes so soft as to tear in threads, and then add one pound of lin- seed varnish, and stir it well with a piece of iron and when boiling take it from the fire and pour five pounds of turpentine to it and filter while hot. To remove the coating of this varnish use a mixture of alcohol and turpentine which restores the former color and brightness. jeweler's hand-book. 19 There is yet a different way remaining to gild or silver the inside of goblets, &c, without covering the outside with the aforesaid composition. A piece of bladder is taken which contains a piece of zinc connected with a well nealed copper wire, sufficiently long to wind around the goblet. The inside of the goblet is rilled with gold solution and the nealed copper wire which bears at the other end the lump of zinc, is now wound around the gob- let and the bladder filled with salt water encloses the zinc and is then hermetically closed and suspended over the goblet so as to reach into the hollow of the goblet. A contact between the bladder and the gold solu- tion will promote the current, and if the solution of gold has been warmed to forty degrees Cel. previ- ous the process will be performed in much less time and the color of the gold heightened. As soon as found sufficiently covered, the goblet is washed in rain water made sour with some cream of tartar, and is ready to be polished. This method of gild- ing by a single element (constant chain) meets all de- mands of the trade as for durability, beauty, and cheap- ness, although at the same time we do not mean to impart the idea that these elements entirely substi- tute the use of batteries. An additional advantage is gained by the use of certain batteries (combined elements), as the solution is always kept at the same scale of concentration and does not require a reprepara- tion, as we shall show when arrived at that head. 20 Solutions used for single elements exhaust them- selves by long or frequent use and fresh gold chloride must be added to keep the solution concentrated. The fresh chloride requires only one-fourth the cyanide used at first, as the average of cyanide already con- tained in the solution reanimated by the addition is capable of absorbing the chloride and transferring it to the negative pole. But to make sure of the neces- sary quantity it would be advisable to dissolve one- half ounce cyanide of potassium in one-half pint of rain water and add as much of this solution as will dissolve all the matter which has settled at the bottom, after which the solution will become quite clear, show- ing a light yellow color. It must unquestionably be admitted that the electro gilding has every advantage over the old practice of fire gilding, as the latter process consumes more mate- rial, more time, and in some instances could not be performed at all, while the liquid gold solution enters the finest cavities, and deposits its contents there as w r ell as on the most even surface. It will be welcome to learn the pecuniary advantage of these two opera- tions: One dozen watch cases can be fire plated in two days by a good hand, while they can be galvanized equally as well in one hour. It will take 2 dwts. of fine gold, worth $2*50 Quicksilver, gilding wax, &c, 50 $3-00 JEWELER'S HAND-BOOK. 21 A solution of cyanide of gold will gild twelve watch cases, holding twenty grains of gold, at an ex- pense of $1*10, showing thus a saving of $1*90 on one dozen cases. Supposing the fire plater to receive $2 (10 hours labor) per day, the cost for gold and labor will be $7 — and if galvanized, we calculate for the same work, $1*30. We think that economy like this should greatly reduce the old practice, and to our rejoicing we would state, that the greatest factories in this country, and in Europe, have adopted the galva- nic agent in place of the ancient fire plating. It is likewise due to say, that a fire plated article will stand five years moderate wear, while the galvanic plate will last but half the time, but the cheapness attending it will admit of its being plated over three times, and still being the cheapest yet. Before w T e close this chapter and proceed to silvering with the single cle- ment, we take leave to state that we gilded a piece of copper sheet of tolerably strong make and worked the same into a small cup, and after polishing it well we filled it with aqua fortis and boiled it upwards of fifteen minutes without injury to the cup. CHAPTER II. To Silver with the single constant Chain. As the apparatus used for silvering is exactly the same as we described in chapter first, page 15, we shall not lose a moment to acquaint our readers with the preparations of the several solutions answering the purpose. 1 One half ounce of silver coin is dissolved in one half ounce of chemical pure nitric acid, and when dissolved thin it with one half pint of rain water, and then one fourth ounce table salt, or one half ounce muriatic acid, added to the whole, will precipitate the silver to the bottom of the vessel in the shape of a snow white substance. This substance (silver chloride) is dissolved by a solution of three ounces of cyanide of potassium (granulated), in one quart rain water, the chloride of silver having been washed previously to free it of the nitric acid, and then another solution containing two ounces of sal ammoniac is poured into it, and the whole must now be boiled for at least one hour, refilling the evaporated water, and then being filtered must show a bright yellow color, and is then ready for use. jeweler's hand book. 23 As many practical men will find it difficult to han- dle so many materials in order to obtain a good solu- tion, we have found another composition in preference to the above, as any kind of silver will answer, no boiling being necessary, the addition of spirit of ara- inoniae to be dispensed with and the whole being just as good as desired. One ounce of alloyed silver to be dissolved in a sufficient quantity of nitric acid; when dissolved one half pint of rain water is added; we then pour in mu- riatic acid as long as any boiling is perceptible; we then pour off the liquid, and rinse it in clear rain wa- ter till all the bluish tint is vanished, and the white substance settled at the bottom; we then add a solu- tion of three ounces cyanide until the whole of the substance is dissolved, making a light yellow mixture, and is ready for use. As a general rule, silvering is effected easier and in much less time than any other galvanic process, and half of the electric power is required to throw silver on a metallic article, and never will it be necessary to warm the solution, as the ordinary temperature is suf- ficient. To effect frosted silvering, the article must remain about one quarter of an hour in the solution, then be dipped into boiling rain water and be dried in the air. If, on the other hand, it would be desirable to have it bright, brushing or rubbing with cream of tartar will produce it. 24 jeweler's hand-book. It will be of the utmost importance to clean arti- cles most scrupulously, and handle them always with wet fingers, as a great many spots will arise from handling them uncarefully. The silver deposited ad- heres tight, and can not be worked through by po- lishing, hammering or stretching. It might happen that a fresh solution would produce a grey instead of a white silver, or perhaps it might blacken the article, but the operator must not despair of success; then, in the first case, cleaning with cream of tartar or white sand will suffice to remove the de- posit, and in the last case a lump of soda precipitated into the solution will annihilate the iron connected with the cyanide, and the fresh and well cleaned arti- cle will show a good white silver color when taken out a second time. Although silvering is a very easy and quick mani- pulation, still certain rules must be observed to make sure of a good result. German silver goods must be suspended with lead wire, as otherwise however strong the silver coat may be, it will peel away and not stand finishing. Steel, iron and bronze must be coppered first and suspended with platina wires. .Steel spectacles must lose their blue coat as no sil- ver would remain otherwise. The same rule must be observed with regard to steel peus if blue, and when brown they must be washed with nitric acid in thirty parts of water; in the former case a mixture of one jeweler's hand-book. 25 part S'lphuric acid, thirty parts water, will remove the blue outside and restore the original color. As the apparatus described and illustrated as No. 2 is fully qualified to transport and deposit gold, silver and copper, we refer the reader to those pages relative to the use of the single element (constant chain), and proceed now to acquaint our friends with the necessary information to prepare a good, copper solution.. CHAPTER III. To deposit Copper by means of the Single Element (Constant Chain). The main object of applying a copper surface to other metals is' to protect them against the injurious influences of a moist atmosphere. It was proposed in the Mechanics' Magazine, vol. 31, page 162, to cover steel, iron, brass, &c, after they are "well cleaned, by the so called salt of copper, which material is too well known to admit of a new analysis. This dissolved salt of copper was applied by means of a brush and dried over charcoal heat and looked more like oxided iron than copper. Another proposition, to use a mixture of blue vitriol and ver- digris, was of no better result. In both cases the coat- ing was not proof against oxid. Before we detail our prescriptions, we deem it of moment to inform our readers that cast iron goods, if very much covered with rust, must be freed from this oxid by the following chemical composition: Ninety-eight parts of muriatic acid and water 45* Be and two parts vitriol of copper, in which they must remain until all rust is removed* 27 One ounce copper dissolved in sufficient aqua regia until air acids have evaporated and then cleared with eight ounces cyanide, in one quart rain water, until all blue color is gone, and the appearance is like clear water. Another less complicated preparation will be the following solution: One half ounce of blue vitriol crushed very fine and dissolved in one pint hot rain water and the blue li- quor dismembered by a solution of one and a half ounces cyanide dissolved in eight ounces rainwater. Apparatus No. 2 will serve as an agent to deposit this copper, but the solution must be warmed to thirty deg. Cel , and will generally take six times longer than the operation of gilding or silvering. PART II. To Gild by Contact and without any Apparatus. CHAPTER I. Monsieur de Frankenstein, in his lectures, claims the merit of having first and successfully suggested the fdea of producing an electro galvanic action by sim- ply bringing into contact two metals in a compara- tively neutral solution, and without the influence of animating or exciting acidulated liquids, and even wiihout the otherwise indispensable union of the two poles. As the experiments of M. de F. must be re- ported satisfactory, we shall not tarry to illustrate the proceedings. One dwt. of gold dissolved in aqua regia; (here equal parts of nitric and muriatic acids); evaporate all acids and dissolve in a separate vessel one fourth ounce of cyanide of potassium, (fusse), one eighth ounce of corbonate of Kali one fourth ounce of cooking salt, altogether dissolved in one quart of water; then the gold chloride is added. This mixture must then be boiled, and filtered afterwards. This solution, although very complicated, will pro- duce the wished for result, but as the ingredients of jeweler's hand-book. 29 this composition are too numerous and rather costly, we have to recommend the following method, which will be found equally as efficient. One dwt. of gold chloride dissolved in one quart of water already containing three fourths of an ounce of cyanide, three fourths of an ounce cooking salt, one half ounce chrystalized soda. The prevailing yellow 7 color will soon disappear and the mixture become as clear as spring water. The following is an illustration of the apparatus: No. 3. 1. A porcelain vessel containing the solution. 2. A strip of zinc. 3. A plate of zinc holding No. 2. 4. A spirit lamp. The article to be gilded is clasped to the end of the strip No. 2, which reaches into the vessel: the article 30 jeweler's hand-book. must be sufficiently covered with the solution and the end of the zinc strip, which holds the article to be gilded, must be well scraped so as to appear as bright as possible, and by this means the gilding will be done in two or three minutes. Another still simpler mani- pulation will be the following, purporting the same result: A fireproof, earthen or china vessel, containing one of the above mentioned solutions, heated to forty deg. Cel, the article to be gilded is heated to the solution, and touched with a bright piece of zinc will imme- diately show a golden coat. All metals (J^erman silver and steel excepted) will receive a beautiful color, but these two metalb will have to undergo a washing in a mixture of one part of nitric acid and thirty parts water (clear), and then they will be fully ready for gilding. We headed this chapter by saying, gilding without any apparatus: to prevent misconstruction, we would beg leave to state that no work can be done without tools, and that a strip of zinc is not exactly an appa- ratus but a mere tool, and as the practice excludes the use of single and combined elements or any other galvanic apparatus, we thought ourselves justified by calling the operation gilding without any apparatus; but for the sake of verifying our assertion, we shall treat our reader to a manner of gilding where not even zinc is requisite. But this process, although it has its merits, would hardly be commendable, as the pre- jeweler's hand-book. 31 paration of the solution is too costly and the gilding stands no handling. Dissolve one dwt. of fine gold in aqua regia, over a moderate heat, until it becomes purple, then mix the gold salt (chloride) with one part rain water, then add a solution of one half ounce carbonate of kali, until the liquor becomes turbid and then of a greenish color. This solution has to be warmed, and when boiling is ready for use. By this means well cleaned objects of brass, copper, zinc and tin can be nicely gilded if sus- pended from a bright copper wire for a moment. Silver and German silver require iron wires. Steel and iron have first to be coppered. The kind reader will now conclude that the head of this chapter is no exaggeration, as it finds its verifi- cation in ihe last named process, which does not ex- hibit the presence of any galvanic current, although we positively deny, when speaking of the illustration No. 3, the presence of a regular galvanic conflux. CHAPTER II. To Silver without any Apparatus. To commence this chapter we would say that it is but just to give M. de Frankenstein's method full credit for the successful issue of this idea when first men- tioned. He dissolved one quarter of an ounce of silver, no matter whether chemically pure, in one-half ounce nitric acid, and transferred this chloride of silver into a solution of one pint water containing one quarter of an ounce cooking salt. A heavy white looking substance was formed at the bottom when the rest of the liquid was removed. This white substance was washed until it appeared of a snowy whiteness and then two ounces of sal ammo- niac were poured over it. Another solution consisting of one and one-quarter of an ounce cyanide one and one-fourth of crystalized soda one-half ounce of salt and one quart of water was prepared to receive this substance (chloride of silver.) To this mixture the chloride of silver with the sal ammoniac was added and boiled for some minutes and then filtered. By this solution, wares of German silver, copper, 33 brass, and bronze can be silvered by merely holding them into the boiling solution The following is another very useful prescription: One part chloride of silver mixed with three parts cyanide, adding enough water to make it a thick paste. This mixture is applied by means of some woollen rags and effects a bright silver surface which, however, is not proof against a hard polish. Although the usefulness of the contact operation can not very well be denied, it is, however, lacking of a general practicability as very large articles could be but imperfectly acted upon Another stimulus of the process of silvering will be the use of a piece of zinc (bright) as by this means a deposition is sooner effected. Another and a very important difficulty arises from the use of the zinc strip as the zinc covers itself, even by very limited use, with cyanide of zinc which has to be removed by continual cleaning as little parts of this cyanide amalgamate with the solu- tion and make filtration requisite as other wise those little flakes impart spots upon the silver surface, and in some cases the cyanide accumulates to a very con- siderable quantity and interrupts the process of ab- sorbing altogether. Let all that remain as it is, M. de Frankenstein has the honorable merit of having invented the most simple and most practicable (in some measure), method of decomposing metallic liquids. 4 CHAPTER III. To copper by Contact and without any Apparatus. To produce a copper surface we recommend our solution described on page 27. A bright strip of zinc will answer exactly to effect the deposit of copper which will be proof against the influence of every atmosphere. A method to the same purpose will be the solution mentioned on page 26 where simply the remaining of the article for the space of fifteen minutes is necessa- ry to produce the desired efFect. As we have no other practical method to refer to, we will conclude this part by proceeding to the most important section of this book. PART III. To gild by the cooperation of combined (constant) Chains or Galvanic Batteries. CHAPTER I. The definition of the term galvanic battery is the connection of several constant chains (elements) by means of which a more powerful galvanic current is produced; a circumstance simply explained by the fact, that every chain exercises a certain galvanic conflux and if several such chains (elements) proper- ly united among themselves are necessarily qualified to produce so much more galvanic power. Galvanic power or galvanic electricity are names given to that form of electricity which is produced by chemical action. It is established, that when two me- tals are placed in contact with each other and with some liquid capable of acting upon one more than upon the other, electricity of a peculiar character is developed. The peculiar electrical relation to the metals employed, also exerts an influence upon this result. The metals most extensively used are zinc and copper, or zinc and platinum; and the chemical agent 36 JEWELER'S HANL-BOOK. is some liquid containing an acid having a powerful affinity for zinc. The language adopted in describing the resulting phenomena was founded originally on the supposition that electricity is given out to the copper from the zinc, which is corroded through the liquid between them. If a glass vessel filled with fluid, would contain a copper and a zinc plate, expos- ing their respective surfaces without being in contact, the supposed motion of the electric current within the glass w T ould be from the zinc to the copper, and if the two metals are connected by a wire without the vessel, in order to fulfill the condition of metallic contact, the electricity is supposed to pass around through the wires from copper to zinc again, to restore the equili- brum of the fluid. Thus the current is considered as passing from zinc to copper within the series and from copper to zinc without it. The wire connected with the copper is the positive pole (anode) of the arrange- ment, and that with the zinc the negative pole (ca- thode). The electricity proceeding from the positive pole is the same in its relation as the electricity from the prime conductor of the electrical machine, which ori- ginally received the name positive, while that from the negative pole corresponds with the electricity ob- tained from the rubber of the machine. These terras are, however, to a certain extent, arbitrary. It is still an open question, whether there is one fluid moving in a particular direction, or two fluids moving in oppo- jeweler's hand-book. 37 site directions, or no motion of a fluid at all. The fact which is sought to be explained by these theories re- mains fixed. For the above described circulation of the electrical current, technically called the galvanic circuit, there is an electrical influence propagated in a certain unchanging direction, and as the control of the magnetic and chemical reactions produced depends upon our knowledge of this, it is necessary that the signification of the terms should be understood. Professor Farraday has proposed a nomenclature of electricity, which has been adopted in some scientific treatises. The poles are called by him electrodes, from the Greek >j\sx