| Show from the new york torte evening post AN HOUR AT THE ASSAY OFFICE what becomes of the gold doubtless this is is the question that some readers are often puzzled to answer they hear of the safe arrival of large quantities at this port but bat after that they know nothing of it except when they are re minded of its presence by the sight right of some bright newly stamped coins which however has a proverbial facility for lor taking g to itself wings before the possessor has had time to reflect whence it comes or whither whitler er it goes if our inquisitive readers will take a walk with us to tile the granite building adjoining the custom house in in wall street and now occupied as the united states assay office they will be able to satisfy their curiosity here the value e of the gold brought into our city is is determined and it is is prepared for coinage or cast in in bars lor for tran iran shipment the assay office proper where the melting refining parting and other operations upon the gold are performed is is in the rear of the building fronting fron Iron ting on wall street in front are tiie tire sub treasurer office and weighing room and the private rooms of various incumbents of government ollices let us first visit the weighing room here all the deposits whether in in bars or dust gener ally hoever however in in dust dast are first brought and here their original weight is is ascertained the dust is is not as might be inferred from the name a fine bright yellow powder but hut looks rather like ding dingy y brass colored granite broken by iby a hammer into the fineness of ordinary turk 3 s island salt afler after weighing fr the deposit is carried into treasurer s vault in the asay office proper whence it is taken and melted the melting is done in crucibles Cruci bles two or three gallons over a coal fornace furnace 17 mace heated to an intensity that would satisfy himself the poor swarthy bhoj superintends super intends with a ion lon long iong handled lad iad lade e say ten feet in len ien length ah even at ahat chat that distance turns to a most hue bue of complexion and has hils to abandon the work in a ew hours for the rest ot of the day in an hour or two the contents of the crucible can be dipped out and the molten mass poured into molds by which it is shaped into bars of about three hundred bundred ounces ounce each the gold is is then returned to the vault of the and refiner a cell some twelve feet square with two iron doors secured by four our locks and with granite walls put putte aether together with cannen cannin balls inserted between the stones in such a manner as to defy the most ingenious and persevering se eribo burglar four men are appointed to sentinel this depository V t night night and a similar provision is made for the th e treasurer s vault where the g gold 0 ld thai has fias gon gone through i all tile the processes which are appointed for il it is placed on entering this vault we were not at first impressed with the appearance of what was as there exhibited but how flow much buchit it expanded ones estimate of what lie saw when informed that that diminutive pile of golden bricks was worth half a million there it lay as hood nood 11 I 1 1 says gold gold gold gold bright and yellow hard bard ind prid cold motton melton graven hammered mid and rolled tolled 1 leavy heavy in 10 get rind liblit to hold bart birt bartered ered boullit and sold stolen borrowed ed doled spurned pu ned nel by the voting buth huth ged bv the old to t tiie tire e very verge oatlie churchyard mold PC price of or inina n any a crime untold fi gold gold gold gold good or bad a thousand ud fuld but to return to business the gold is next to be assayed that is to have its value and i fineness ascertained by a delicate chemical process which is performed in this wise on each deposit which still eill retains with its gold the various impurities with which i aich il it first came out of the mine two bars are selected at random and a small shaving of a prescribed weight is cut from each rach A pair of scales is employed so delicate that the thousandth part of a grain will turn it to weigh them separately they are then wrapped round in a thin coating of lead and having been ben put into little cups called cup els eis made of phosphate of lime or in plain english of burnt bone are sui sut subjected ejected to an intense heat beat at once the lead melts and uniting with the copper and other foreign ingredients of the gold assists the oxidizing and with them thein is absorbed into the porous substance nce nee of the cup cu 1 leaving no sign except a dark stain of its presence but the gold still shines out in the cup in i by a tri trifling fling flina wash of silver sliver looking like a small button to separate these it is placed on an anvil and flattened with a hammer to such a thinness is may make it permeable to the nitric acid acia in which wh ch it must now be immersed A small long jong necked bottle called a contains this fluid into which lie he drops the button the bottle is heated over a furnace fur nace naco and tile the acid completely absorbs tile the remaining alloy leaving the gold perfectly pure with only a slight black covering of oxidized alloy which is removed by ay annealing the adhering acids are then washed off and all h has to do is to re weigh the two shavings of gold and to ascertain how much the they y have lost by the chemical chan changes ores cres they h have e been put through ile he thus discovers w what hat proportion of pur pure e metal is remained ned in a given give n part ot of a deposit de p and from this judges of ahe fineness and value of the deposit itself th the owner then can receive its value in pure pum bars of other gold and go on his div way resigning all claim claim to the original quantity which he brou brought glit to the office the responsibility of the tire and refiner now begins ilis his business is merely bat that hat of his predecessor only on a less delicate andruch and much larger scale i c to free the entire deposit froni from alloy I 1 we bee the workmen in tile the granulating room sweltering over seven large furnaces along the sides we notice that the ce ment floor of the apartment is covered about two inches deep with which small particles of gold or silver have hove ho vf been careleE carelessly bly or unavoidably dropped it will not do to lose themi them and so at certain perica the floor is carefully swept and the sweeping dirt and 1 all with the mens aprons the discarded cruc cruci crucibles bles bies ladles etc are collected burnt ground and otherwise transformed till a ver very considerable revenue of tal tai is obtained what it amounts to in the assay office has not been definitely stated but WP we were told that at the mint in philadelphia it came crime to the handsome figure ot of a year lie hie melting is now tobe lobe t attended to one hundred pounds of silver to fifty of gold is I 1 placed it in each crucible cruci lile ille the rule being two of the itar m er to one of the latter lalier after afler an hour and a the two are arp rendered fluid and the mixed metal is poured into a large copper vessel containing con cold water to which a mo tion lion is given this motion lias has the effect of preventing the solidification in a mas of the metal causing caus irig it to harden and sink to tile the bottom bottoni in the form of flakes or grains hence alence it is called the process cf granulation and the mixed metal from the excess of silver in its composition is called granulated granil silver it is certai certainly beautifully white while looking like ilke the oxidized silver si iver iven that we see among the ornaments ments of a jeweller jewellers je weller wellers s window as indeed inde d it is the ii same sime thing nt nut only has it been melted itself but lut it has facilitated the melting of the other alloys of the gold and arfer after drawing them oaf out and mingling ingling in with I 1 hem has completely comp tely incrust ei ej the pure metal metai that is concealed conceal in it the metals are sa p pirated in the tile parting ro rom m where the granulated silver is carried we vve find roun four rows ot of eight porcelain pots each with a capacity of from twenty wenty t to twenty four gallons thy are placed in troughs of boiling bi lino salt palt water and into each is is turned oi 01 e hundred ard fifty pounds of the llie granulated or mix mixed d metal metai oer over which 13 is poured as many poun pour pounds ds of nitric acid this acid uniting with lle ile lie the silver forms a tion lion which is called nitrate of silver and the he effect of such an alliance is tn to fe F i and sink the pure gold to the bottom of ofal the e pr lir the ni tate tale t ate of L liver is then drawn off with a coid cold saphan eroid froid being the only meta meto which can wi hhand its achion and another charge of nitric acid is applied to complete compi te the file work after alter the bec ind charge has been in the same manner remo e 1 wese at the bottom of the pot a black unpromising sediment remaining but the spectator must roust not be discouraged discon raed raged atthe sediment is pure yellow gold as will be shown by wanlung it a few times in warm worm water BO 0 03 its f free ree fee it from the acid arid that still clings to its exterior it now appears thoroughly pulverized and fairly entitled to the name of gold dust the tile next operation is is to solidify it by subject in ing g it to a pressure of two hundred tons from a ha hydrostatic prostatic dro static press when hen it comes out oui on in the tiie form ot of cheeses about a foot ii ia diameter dia diu meter with a thickness of three inches then put it on a furnace heated red hot lot so ss es to expel the last drop of water from it and again melt it in a crucible from which will ch it must also again be molded into bars of fine gold varying according to their size and fineness from to in value I 1 these are once more inore assayed at the hands of the assayer by bythe the process before explained stamped to indicate their number fineness and weight and aad committed to the vault of the he treasurer there here to await his disposal it is only such bars that are received at the banks who are un unwilling illing to accept those tho e which have been assayed without the authority autho rity rily of the government their conversion into money must be done doue at t the tile folint A int in philadelphia our merchants also for several reasons prefer the gold bars to coin in making their foreign payments in the first place they are cheaper as they are are ire compelled to pay gifty fifty cents on a hundred dollars for money while tile the charge for bullion of the tile same value in bars is but six cents they aliey are moreover more moie over obviously more acceptable to merchants abroad than our national I 1 coin except in those countries where coin is wanted to cupply emigrants bound for our shores shoes the fineness of the tile bars manufacture dat tile the assay office as shown by its operations on 0 n the last deposit of california gold was 9 sari sati sandl dilis dills hs a success not hitherto equaled liyana b yany other simi ar establishment when first deposited with the assayer it ranges range pv on an average from to thousandths of pure metal according to the requirements ot of congress our ne national dional coin must roust contain ten per cent of al alloy loyie ie one hundred parts out of every thousand fine bars hy by the same rule are required to consist of thousandths of pure gold it ith a permission to refine as much further as may be found possible but to complete our account we nye should give a report ot of the fate of the silver drawn off in solution with nitric acid from the porcelain pots chich which we have mentioned all we have hake to say is that it is emptied into an enormous vati vats vat sat nearly filled fil ed with a solution 0 of common salt the silver is thus precipitated that is sunk in a solid form foro to the bottom bollom becoming what is called chloride of silver it is tilen their freed from the acids adhering to it in the same manner as we have mentioned in the cafe of gold reduced reduce a to metallic powder poa der by an li into vats containing sup buric acid and zinc washed pressed dried and cheesed in precisely the llie same bame way as gold and ia is thus ready to be re melted and re employed for fur the purification of the more decious metal such js is a brief account of the process processes ps used by I 1 actie the new assay office in performing the duties s assigned bythe by the govern government anent I 1 to 0 it every one knows how iipp and necessary it is to the interests of burnesa bui bul bu iness ness nesa in all an immense commercial city like nev new york it has been too recently established to enible en ible us to presen Pany statistics showing any thing more than a it probable bl estimate of the extent of f its is ope epe operation ration for a year A single arrival from california on an average av arage brings it a deposit of nearly a million and a quarter in value and such arrivals occur weekly this would give a monthly lalion of five millions the machinery of 0 the office is enough tr for the annual assay of luf fifty millions fifty men are now employed in carrying on its ils opera oper lims aliens |
