REP ORT
PROFESSOR R. S. McCULLOHW
TO THE
SECRETARY OF THE TREASURY,
UPON
REFINING GOLD WITH ZINC.
GIDEON & Co., Printers.








MREPORT
A.1E'TO TH,
HOlN. THOM-AS  CORW IN,
SECRETARY OF THE TREASURY,
PROFESSOR R' S. McCULLOH,
OF HIS
OPERATIONS AT THE MINT OF THE UNITEI) STATES,.IEFINING CALIFORNIA GOLD
ZINC METHOD.
WASHINGTON:
GIDEON & CO. PRINTERS
1852.








rTREASURY DEPARTMENT, December 26th. 1851.
SIR: I forward herewith the copy of a letter firom Professor McCuIlofi on the subject of his views as to the mode of testing his new pro —
cess for parting gold and silver bullion. It is the wish of the Department that the process should have a full and fair trial at the mint in
Philadelphia, and you are requested and instructed to afford Mr.
McCulloh the needful assistance and facilities for so doing. In order
that there may be no cause for complaint on his part, of either error
or mistake, the actual process will be conducted under his especial direction, and with the concurrent custody of the bullion, during the
whole operations, between him and the proper officer of the mint. It
is understood and agreed with Mr. McCulloh, that the United States
are to be guaranteed by him from all loss or expense attending the
trial beyond what attaches to the present mode, though any additional
expense for erecting furnaces, and which may be subsequently useful
to the United States, will be borne by the mint; and that. any additional advantage or profit attending his present process will be applicable to pay any extra expense, outlay, or loss of any kind, which
may attend the proceeding, for which he might otherwise be liable.
The experiment can, in any result, be carried to the extent of'the
separating of two or three hundred thousand dollars of bullion; and
if, from that result, you find no serious loss is likely to occur, you can
continue it on a larger scale, as you and Mr. McCulloh may deem
necessary or advisable; or until he may be satisfied as to the extent of
the operation.
You will please understand that the Department wishes the process
tested in a manner and to an extent which will enable you to report
fully and definitely as to the nature of it; and whether it will be advisable to introduce it permanently into practice in the future operations
of the mint and branches.
Very respectfully, your obedient servant,
WILLIAM  L. HODGE,
Acting Secretary of the Treasury.
Dr. G. N. ECKERT,
Director of the mint, Philadelphia, Penn.
PRINCETON, Noveimber 13, 1851.
SIR: Your favor of the 15th ultimo, and the enclosed copy of a
report from the director of the mint of the 14th ultimo, were duly
received.
For the present, I forbear from remarks upon said report, except in
relation to the practical question of a trial of my process for refining
gold, to be made at the mint, and in my presence.




iv
Such a trial having been recolmmnended by the director of the mint,
and he having suggested that it might be equitable "'that any loss of
gold, if over and above the ordinary wastage, be borne by Mr.
McCulloll," you have been pleased to inform me, that the Department will authorize a renewed trial, and that "it coincides in the
opinion of the director, that any loss of gold which may accrue in
Hnaking the experiments should be borne" by myself.
As it was, I presume, the intention of your instructions to the director of the mint, dated January 11, 1851, to accord what I had
requested in my letter to you of December 23, 1850. that my aforesaid process should be tried "under mny direction," and as it is now, I
suppose, the object of the proposition concerning excessive loss, if any
should take place, which I believe impracticable, that the United
States may not incur risk thereof by experiments to be tried by me, I
respectfully submit that I will assume, and relieve the Government
from, the risk and expense, if made under and in compliance with the
following conditions:
1. That an account shall be opened between the contingent fund of
the mint and myself, by the treasurer of the mint, in which I shall be
charged with the. cost of the labor and materials employed by me, and
the loss or waste of gold and silver which may occur in tthe trial of
said process; and slhall be credited with the amount charged according
to the present rates, and paid by the depositors of the bullion operated
upon by me, for labor and imaterials to be employed in refining or
reducing said bullion to the same composition, fineness, or degree of
purity, and shall also be credited with an allowance equal to the ordinary waste or loss of gold and silver incident to the operations requisite for said purpose by the method now employed in the mint; said
ordinary wastage, or the rate thereof, to be first determined andl agreed
upon by the director of the mint and myself.  And any loss or profit
which may be exhibited by said account shall accrue, in the settlement
thereof, to myself and not to the United States:
2. That the operations of said trial shall be conducted under my
exclusive direction and control; and such gentlemen as I may invite,
shall be permitted to be present, and to verify any of the acts or results:
3. That the bullion operated upon shall be in the joint custody of
the treasurer of the mint and myself, or, in the absence of either, thent
of such person or persons as he may designate and authorize to personate him; and said bullion shall be kept entirely apart from  the
bullion in charge of the melter and refiner, and in such manner as
may be agreed upon by said treasurer and Imyself:
4. That, if after having refined an amount not exceeding $250,000,
it shall not appear that the waste and expense are necessarily such as
will devolve loss on the Government by continuing the trial, then said
trial shall proceed under my direction and the concurrent custody aforesaid, to determine and establish whether the process can be applied in refining the usual large amounts of gold daily operated upon in the mint,
with greater dispatch and economy than are attained by the process
now employed:




5. That, before operating upon a large quantity, I shall be allowed
to cause several small operations, of one or two thousand dollars each,
&o be performed, for the practical instruction of the workmen, and the
convenient adaptation of the method to the apparatus and manipulations
to be used by them; and shall be permitted to take small samples for
assay in exchange for gold of equal quantity and value:
6. That every proper facility shall be extended to me, and such apparatus as I may require, if not available in the mint, shall be ordered
and constructed, or' mod0ified, under my direction, the cost to be borne
by me, if the said apparatus wrill not be useful ill the mllint, after I shall
Lwtrve concluded my operations.
Very respectfully, your obedient servant,
R.ICH'D S. McCULL, OH.
ionr. THl:fOMAS CoRwVIN,
/Secretarvy of the T'ieasuiy.
















RE P O R T.'To the honorable THOMAS CORwIN,
Secretary of the Treasury.
SIR: After having received authority to try, in the mint at Philadelphia, my method of refining gold by the use of zinc, I went there
without delay, and delivered to Dr. G. N. Eckert, director, the letter of
instructions from the Department of December 26th, 1851, and the copy
contained therein of my communication to you of the 13th November,
1851. A slight difficulty at first arose, owing to the treasurer having objected to permit gold bullion in his charge to go into the refining rooms to
be there operated upon by workmen under my direction; but, after
correspondence by the director with the Department, arrangements
were made, by which all that I had asked and the Department had
authorized was conceded to me substantially, though varied in form.
2. The general conclusions, or facts, established by my consequent
proceedings, and which I have now the honor to submit, for your inforination, are as follows:
First. That the previous experiments upon refining with zinc, conducted by officers of the mint, in which, besides other errors, more than
seventeen ounces of gold were left in the furnace, did not prove that
said gold had volatilized; or evince care, skill, or accuracy, accidents
not having occurred to mar their designs:
Secondly. That there is no reason to believe that volatilization occurs, when an alloy of zinc and gold is properly made, at a temperature below that of redness, as was done in my large operations, by
dissolving gold bars in melted zinc:
Thirdly. That, by means of suitable apparatus, the granulating of
gold, with zinc or silver, to prepare it for refining, can be more perfectly, economically, and expeditiously done by machinery than by hand,
and much waste avoided:
Fourthly. That, by my method of refining, about $250,000 were
refined under my direction without difficulty, and the refined gold was
of the very best quality for coining:
F-fthly. That when, after having made three preliminary workings,
I was ready to demonstrate fully the great advantages of my process in
economy of time, labor, and materials, by making an operation uport
$750,000, or about 14 tons of gold, the opportunity to do so was denied to me, for the reasons alleged byathe director: that it could not be
permitted, as he did not feel confident that gold so refined would be fit
for coining, and that the regular business of the mint might be inter,
rupted by such a result:
Sirthly. That my method of refining is much more economical, in
materials and labor, than the tmethod now used in the mint, and thaL




2
my workings were actually attended with a saving, in materials and
labor, to the amount of $110 41, which might have been much increased:
Seventhly. That my zinc method of refining is not subject to more
wastage than the silver process employed; and that my only working,
in which accident did not occur, compares favorably with the results
of one, made for a like purpose by said silver process, and reported by
the late director of the mint, Dr. Patterson, in his letter of May 9th,.
1851, to the Department:
Eighthly. That in two of the three workings, made under my direction, accidental spilling of melted metal occurred-to which, however,.
my method is not more liable than other methods are-and that these
accidents caused an apparent excess of wastage, notwithstanding which
the aggregate returns were deficient to an extent only of about one half
of the least wastage shown in the experiments made by the officers of the
mint, which were not attended with evident accidents; and that any
seeming loss, which these accidents may have occasioned, has been fully
compensated to the mint by an amount of gold, which I have
caused to be delivered to the director for that purpose, although I
might equitably have been considered free from any such pecuniary
liability:
Ninthly. That my method of refining would save all the silvery
wasted in the present process, out of the large quantities used for quartation; and that this saving, in my aforesaid workings, probably amounted to more than 21 ounces:
T'enthly. That the question of the comparative wastage of gold, in
the two methods of refining under consideration, is one within the
limits of the probable error of the most accurate assays; and in relation
to which, these do, therefore, become to some extent uncertain, and in
an equal degree inadmissible:
Eleventhly. And, finally, that by my method of refining, besides saving the interest now incurred by the nation, there might have been saved
$106,579.87 out of $212,285.38, charged to the depositors of gold bullion, for silver alloy, and for materials and labor, required to separate
the silver from their gold, during the period beginning November 14,
1850, and ending December 31, 1851; and of which $212,285.38,
all that portion charged as silver alloy, and amounting to $88,337.75
was lost, not only to the depositors, but also to the industry and wealth
of our country:
3. But that all of these facts may be fully shown, I have seen fit to
present the following details; and that the statements made therein
may be confirmed by the testimony of disinterested and intelligent
persons, who witnessed what I did, I have addressed interrogatories to
and received replies from workmen of the mint and others, who assisted me, for copies of which, see Nos. 1 to 19 of the Appendix. And I
may here add, that no one of the officers or clerks of the mint, who
were all commonly occupied in their respective avocations, and only
oczasionally caile into the workshops, either followed my proceedings




3
or can speak of knowledge fillly, connectedly, and accurately concerning them.
The superintendence of the weighings of the gold was devolved by
the director upon Mr. Benson, his clerk and nephew. But to the
workmen alone, and particularly to Messrs. Monell and Porter, foremen of the melting and refining department, was entrusted the responsibility of observing and aiding in the operations performed, the taking of accounts of materials and labor used, and the concurrent custody of the metal refined under my directions.
Martin Summers, formerly, and for many years, gold melter in themint, and Townsend Yearsley, brother of Pascal Yearsley, bricklayer
at the mint, were assistants employed by me, with the approbation of
the director. Woods Baker, esq., of the U. S. Coast Survey, also
aided me, in.pursuance of instructions of the Department.
4. After I had examined the melting and refining department, in
company, first with the director, and then with the melter and refiner,
Prof. Booth, on the day of my arrival at the mint, it was agreed between said director and myself, with the consent of the melter and refiner, that Pascal Yearsley, the bricklayer of the mint, should proceed,
under my directions, to tear down the cupelling or reverboratory furnace, which had been constructed in the basement or cellar, in January, 1851, and to rebuild the same in such manner, as requested by
Prof. Booth, that it would be adapted to the convenient refining of
silver, after I should have employed it for refining gold —the plan of
the new furnace to be first submitted by me to Prof. Booth, and to be
approved by him. The three silver melting furnaces were also placed
at my disposal; two of which required to be rebuilt, and the third to be
removed to make room for a new furnace, which I intended to use
for alloying and granulating the zinc and gold. I was occupied during the whole of January, and until the 5th of February last, in the
aforesaid task of constructing furnaces, and superintending the machine work needed for my granulating furnace, the execution of
which required much time, and retarded the brick work.
5. When the aforesaid cupelling furnace was toni down, Mr.
Yearsley, according to my orders, caused all the dirt, &c., contained
therein, to be carefillly removed and delivered to Thomas Llewellen
and James Kane, workmen of the melting department, who extracted
from said dirt, by grinding, sifting, and washing it, seventeen ounces
of gold in grains, which were melted by Archibald Porter, foreman of
the melting operations.
As said furnace had been constructed and used by the officers of the:
mint for their experiments upon my method, and had never been employed for other workings, the finding of seventeen ounces of gold
therein proves that those experiments were incorrect, and that this
gold, left by those officers in said furnace, had not escaped up the
chimney, in conformity with their hypothesis of wasteful volatilization.
As grinding, sifting, and washing neither do nor can extract from




auriferous dirt tile whole of the gold contained therein, but do always
leave a considerable portion, which may afterwards be obtained by
amalgamation, or by fluxing, it follows, that there must have been gold
in said dirt which the aforesaid workmen did not and could not extract. To ascertain the quantity so contained, I caused said dirt to be
carefully gathered and set apart, and repeatedly requested the director
of the mint to have assays thereof made, which he consented to do,
but if they have been made, the results have not been communicated
to mne, although I have asked for them.
6. In the month of January, 1852, before my granulating furnace
was constructed, but after two of the above mentioned silver melting
furnaces had been rebuilt, I tried with them, as the only means I
possessed, a preliminary experiment of refining 303.24 gross ounces of
gold with zinc. But as the director desired to use these two furnaces
for an operation, to determine the actual wastage attendant upon the
method of refining gold employed in the mint; it became necessary, in
making my alloy of gold and zinc, and in granulating the same, that I
should use such means only as would preclude the possibility of any
of the gold, of my experiment, being spilled into either of said furnaces.
1, therefore, melted the zinc in one furnace, and the gold in the other,
and, when both metals were perfectly liquid, I caused the crucibles
containing them to be lifted bodily from the furnaces, and the gold to
be poured slowly, at first, by one workman, into the zinc, while
another workman stirred the mixing metals, to form a perfect alloy.
The workman who was pouring the gold called my attention, after
some time, to the fact, that the slowness of the operation was causing
the gold in his crucible to become chilled, and partially to solidify. I
then permitted him to pour the remainder rapidly. A piece of soap,
which I had thrown into the alloy to protect it from oxidation by the
air, had nearly or quite burnt off, when the rest of the liquid gold
being poured quickly into the zinc, the too rapid increase of temperature, uniting with the effect of exposure to the air, caused combustion of the zinc to take place, and with such intensity at first, that
some of the hot metal was projected from the crucible, and scattered in
drops or grains upon the floor and various surrounding objects, front
which they were gathered as well as we could. One of these grains
coming in contact with part of the adjacent wood work of the mint,
rendered very combustible by saturation with nitre from the refining
operations, it took fire, which having been extinguished, we forthwith
proceeded to granulate the alloy; and this metal being passed through the
various subsequent stages of my process, yielded refined gold of the
very best quality, which was, also, perfectly tough when melted. The
apparent loss upon this experiment was about 0.44 oz., being ap.proximately 1- thousandths.  It may be here remarked that 2-s~
thousandths was the least wastage reported as having occurred in any
of the experiments made previously by officers of the mint upon
refining with zinc, and in which accidents are believed not to have
occurred. And in this experiment of mine, not only combustion of




5
zinc occurred, but some of the alloy was projected from the crucible,
and part thereof having fallen into a pan standing near at hand, containing metal that belonged to the regular work of the mint, was not
recovered, and could not be reclaimed by me. I did not regret this
accident, for it presented a case in which the hypothesis of volatilization called for a very great wastage, and I so stated to the director of
the mint at the time, but no such marked effect ensued. I should
add that this accident, which occurred from the use of provisional
arrangements, could never happen in the use of my granulating, or
other appropriate, furnaces.
7. On the 4th of February, my granulating furnace being finished,
and sufficiently dry, fire was kindled in it, and we proceeded to try it
with zinc alone. The moisture in the brick-work rendered the heating of the furnace rather a slow operation; but when the metal (343
lbs. of zinc) was melted, the valve was opened, and it flowed in eight
streams down into a large copper kettle containing water, and placed
in the cellar below. Every thing worked perfectly; the granulation
was superior, and the operation was spoken of in terms of high admiration by all who witnessed it. I should here state that this arrangement for granulating is new, and had never before been reduced to
practice. It is part of the apparatus adapted to the working of my
process for refining with zinc, to which I referred in my memorial to
Congress of July 5th, 1850, and in my letter to Professor Booth of July
16th, 1850; also in my letter to the S6cretary of the Treasury of February 28th, 1851; and its introduction would be a great improvement
in the refining apparatus of the mint, even if zinc be not used instead of
silver.  With the results obtained by using this furnace, the director of
the mint was so much pleased'that he freely expressed his admiration
of them; and subsequently, without adverting sufficiently to the fact
that the aforesaid arrangement was exclusively my own, he was pro-,ceeding to apply it in the work of the mint; but upon my remonstrance,
in writing, copy of which, and of his reply, is annexed, (see Appendix, Nos. 20 and 21,) he refrained from so doing.
8. On the 5th of February, I commenced my larger refining operations by granulating 1952.72 ounces of gold, with about 5,000 ounces
of zinc. When the zinc was mnelted, the gold bars, heated to incipient redness, to prevent their chilling the zinc, were put, one after
another, into the zinc, which readily dissolved them without elevation
of the temperature to that of redness.  The alloying was easily and
perfectly done. And, as the director of the ml-int stood by my side
looking at the operation, I caused the melted alloy to be skimmed, so
as to present a clean, bright, and exposed surface to the oxidizing action of the air, and then requested him to watch it closely, and observe whether he could perceive the slightest indication of volatilization or fumes of zinc; he admitted that he could not see, and did not
believe there was any.
In granulating, a difficulty was, however, met with; the pipe passing down into the water, contained in a large copper kettle placed on




6
a carriage in the cellar below, notwithstanding my orders that it should
not be raised, had been elevated by some curious person; consequently,
a draught of cold air came up through it, which chilled the metal in
the bottom of the crucible; so that, when the valve was opened, it was
found to be obstructed, and only four of the eight openings allowed
streams to'flow from them; three of these soon stopped, and the fourth
or remaining stream  became much diminished; it, however, continued to flow until all the melted metal was discharged from the crucible. The granulation was very beautiful, but the valve with eight
openings was so clogged with solidified metal that it was ruined. Orders
were at once given by me for a new valve with only four opefiings,
and for an iron bed plate, to be placed under the crucible in the furnace, so contrived as to render a similar accident impracticable, even
if the pipe should be disturbed. The size of the aforesaid copper kettle was not sufficient for the quantity of metal; it therefore became necessary to slip another similar vessel under the flowing metal; to do
this, a small pan or kettle was momentarily used to receive the flowing metal, while one of the large kettles was removed and the other
substituted for it, which was readily done.
9. On the morning of February 6th, several ounces of alloyed gold
and zinc in grains, belonging to the working of the preceding day,
were gathered in a scoop, which, by nly order, was placed by a workman on the top of one of the melting furnaces, behind a number of
large crucibles. I was called, for a few moments, from the room to
give directions concerning another matter, and upon returning observed that said scoop and grains were missing. Inquiry was made
by me of the aforesaid workman and other persons, but no one knew
what had been done with the scoop and grains. Curiosity had drawn
a number of the workmen of the mint about my furnace, and others
came there prompted by a desire to render service to me. I could not
believe that any of them would intentionally injure my work, and
therefore concluded that some one had taken the scoop to use it as a
tool, and in so doing had thoughtlessly rendered it impossible to know
what became of the grains, which had been placed temporarily where
I supposed they would be free from displacement. I promptly mentioned this occurrence to the director of the mint, though not in a spirit
of complaint, and requested himn to give orders that no one, unless
employed in mny work, should, in any respect, interfere therewith, or
come so near to my operations as to impede them.
10. About noon, on the 6th of February, the new valve and bedplate being finished, fire was kindled again in the furnace, and another
operation upon 1963.58 ounces of gold and about 5,000 ounces of
zinc was commenced; about dusk, the metal was all melted and ready
for granulating; the valve was opened, and four streams of melted
metal flowed from it down int.o the water contained in one of the
large copper kettles, placed in the cellar as aforesaid. But when
this kettle was removed, that another might be substituted for it,
the sliding pipe accidentally slipped from its place, the small pan




was thereby knocked from the hands of the workman who was
holding it, and, for a few moments, the four streams of melted metal
poured down upon the cellar floor, splashing upon the persons and objects around, and scattering in particles to some distance over the floor.
This accident was the only serious one which occurred during my whole
work; for, though the metal was gathered up as carefully as could be
done, yet apparent loss could not be avoided, as it was dispersed
widely and finely, and, as many persons were standing near at the
time, all of whom had their clothes and shoes more or less sprinkled
or studded with metal, and some of whom were there only as spectators, attracted by the curiosity which the novelty of my operations.awakened, and which the instructions, issued by the director, in compliance with my aforesaid request, had not restrained. This curiosity
I mention, not in censure, for it was natural and innocent, as those
who were present certainly did not know, that its indulgence was contrary to my wishes, expressed reluctantly, yet unavoidably, as one effect
of it was to embarrass the operations of the workmen who had been
detailed to aid me.
On Saturday, the 7th of February, we were chiefly engaged in
gathering the metal scattered, by the accident of Friday. On Monday,
the 9th, and Tuesday, the 10th, alterations required by the new bedplate were attended to.  Simplified valves, designed for a single
stream of metal, were made; and the metal, granulated on the 5th
and 6th, which had been put into acid without delay, received
attention. Hogsheads were procured and prepared for receiving the
metal in granulating, as substitutes for the copper kettles; a single
hogshead being large enough to hold the entire charge of the crucible
without shifting, so as to preclude accident.
11. On the 11th, another granulation of 1,995.48 ounces of gold,
with about 5,000 ounces of zinc, was made without the least difficulty.
And immediately afterwards, two successive zinc granulations, each of
5,000 ounces troy, or 343 lbs. avoirdupois, were made, also without'
difficulty; the object of which was to clean or wash out the crucible
with melted zinc. But this operation not having perfectly attained the
desired end, the crucible, which was of wrought iron, was taken on
the following clay, the 12th, to the large machine shop of Isaac P.
Morris & Co., and there bored out, under my superintendence, in the
manner that cylinders are bored for steam engines. This operation
consumed the entire day.
12. It would overload this report with unnecessary details were I to
relate chronologically the operations of each successive day; nor would
it be practicable for me, by so doing, to render evident to the department all the features of my work. My operations involved two leading questions, to wit: first, the merits of my method of refining by
the use of zinc; and, secondly, the merits of my granulating apparatus; modifications of the latter were tried with the view to test,
practically, their respective advantages and disadvantages; and the
valves, especially, were varied in every possible mode-they were




placed internally and externally, horizontally and:vertically —were
made to work by levers and by screws, and to give from one to eight
streams.
13. As all responsibility devolved upon myself, and as others would
have been held to be censurable for anything they might do in error,
however well designed, the workmen had instructions from me to do nothing, except by my express orders and under my immediate direction;
therefore, whenever I was attending to the granulating furnace, or its
work, the operations with acids were held in suspense, and, conversely,
the granulating was checked when the refining was in progress. Besides, when I was absent from the mint, attending to such matters as
the aforesaid boring of the crucible, or to analyses of the materials employed by me, which I made in the laboratory of my friend, Dr.
Chailes Wetherill, who kindly placed it at my service, all my work at
the mint was arrested.
I have set forth these facts, because it should be understood, that
my preliminary trials were made without reference to the questions of
comparative time or economy of labor and materials.
14. The 5,911.78 ounces of gold, or about 400 pounds avoirdupois,
which I have granulated in three separate parcels, were refined with
acid, as one lot, and designated by me as lot No. 2; they were then
toughened in the same black-lead crucible, which was twice filled;
each filling having been dipped out and cast into bars; some metal,
still remaining in the crucible, was cast into a residual bar. These
barswere afterwards numbered promiscuously from 1 to 18. The bars
of the first casting, which were, therefore, all of uniform quality or fineness of metal, were Nos. 7, 11, 12, 13, 14, 15, and 17. Those of
the second casting, also of homogeneous quality, were Nos. 1, 2, 3, 4,
5, 8, 10, 16, and 18; the residual bar was marked No. 6; and to avoid
mistake from inverted reading, there was not a No. 9. All of these
bars were of perfectly soft and tough metal.
15. I have particularly mentioned that they were melted in a blacklead crucible, because it had been imagined that gold refined with zinc
cannot readily be rendered tough, free from brittleness, if melted in
black lead crucibles; which are the kind usually employed for the precious metals-an error that is embodied in the official report of J. C.
Booth, melter and refiner of the mint, February 6, 1851, to Dr. R. M.
Patterson, director, recommending the adoption of my method of refining-copy of which is annexed, see No. 22, of the appendix.
16. My reason for numbering each bar separately was, that I had
understood special assays had been made of every bar delivered to me,
and therefore supposed that the same rule would be followed with reference to those returned by me; and I caused them to be numbeted
in irregular order, the more effectually to verify or check the results of
the assays. The assayer complained of the amount of work it would
require to assay every bar; and therefore, in my subsequent meltings,
through courtesy to him, 1 did not follow the same course; but numbered the bars of each casting with the same number, though, in so,
doing, the advantage of a verification of assays was yielded by me.




9
17. On Monday, February 16th, I granulated 7,874.05 ounces of
gold, the value of which was nearly $150,000. This was the remainder of the $250,000 which 1 was authorized by the Department to
refine under any circumstances.  During the rest of the week, this
gold was put forward in the acid, though not with the despatch which
would have attended uninterrupted work, nor with either the purpose
or effort to economize in time, materials, or labor. My attention was
chieflygiven to the chemical points involved in everystage of the operation, to the avoidance of wastage, and to the instruction of the workmen in the routine required; while the work was allowed to proceed
deliberately, but carefully. On Saturday, the 21st, the refining of
this lot of 7,874.05 ounces of gold was complete, and it was ready to
be washed, dried, and melted.
18. I then informed the director that, on Monday and Tuesday, I
would, with his consent, granulate $750,000 in gold, and refine the
same during that week, as this sum would complete $1,000,000, and
the workmen had become sufficiently familiar with the operations to
be performed, and as the apparatus was in condition to work, without
any trouble, to my entire satisfaction; and that 1 proposed to demonstrate, by the rapid refining of these $750,000, the advantages of my
method, in economy of time, labor, and materials, which I had not
sought to do in my previous work. I also remarked that the profits
would reimburse me for my outlay of several hundred dollars for apparatus, &c.
19. To my surprise and disappointment the director objected, and
said that he did not then feel authorized to permit my refining to proceed upon further quantities, as it had become necessary for him to
interrupt my work for the reasons alleged: that gold bullion had accutmulated in the mint to a very large amount, and the balance of coin
in the hands of the Treasurer applicable to the payment of deposites
had consequently been so diminished that, to enable them to provide
more to pay for gold expected daily to arrive from California, it was
requisite that my operations in refining gold with zinc should be suspended, and that the regular work of the mfint should proceed on
Monday, with the aid of the separating apparatus that I was using;
and, moreover, because he would be unwilling that one million of
dollars should be made into bars like those refined by me, before it
had been shown that they would be adapted to the operations of the
coining department.
20. The director at the same time expressed his regret that the exigency of the public service should compel him thus to interrupt my
proceedings, and to take from me the separating apparatus I was using;and a desire that, at some early and mutually convenient period, I
would come to the mint and refine gold bullion to the extent of. a
million of dollars, to teach the workmen thoroughly how to refinl:-Jt
by my method. To this I replied, that I would of course do. so,
whenever the Government should provisionally agree to acqulirethe
right to use said method.




10
21. I then submitted, however, for the consideration of the director,
the propositions-that I could and would refine a million of dollars
more promptly by my method than could be done by using the silver
process; and that I would ask the Treasury Department to transfer,
temporarily, to the mint a sum of the public moneys sufficient to meet
any immediate transient necessity, and so to enable me to complete
my work without interruption. To these propositions he might have
consented, if he had not believed that such transfer could not be
obtained, and if previous trials had shown that the gold which I had
already refined was well adapted to the operations of the coining
department; but as he held both to be uncertain, and upon these
grounds decided that it would be necessary that I should yield up the
separating apparatus, I did this unhesitatingly, in deference to his
expressed opinion that the public business required it.
22. The large lot of gold I had just refined was melted in black
lead pots; it was designated as lot No. 3, and was of good quality;
though its fineness, when assayed, did not exceed 983.3 thousandths,
as in the granulation the proportion of zinc had been reduced to that
of 2 to 1, nearly.
23. The iron crucible was again bored out, and I proceeded to
extract any gold contained in these borings; after which, grains were
gathered from crucibles, furnace dirt, fluxes, &c., &c.; and these
were also smelted by Martin Summers, formerly the gold melter of
the mint. The gold so obtained being impure, it was refined by the
use of oxidizing agents, and upon bone-ash tests; all the dirt, of various
kinds, was amalgamated; the amalgam itself was distilled, melted, and
refined. The granulating furnace was torn down, the apparatus thereof
was taken away, and the silver melting furnace was rebuilt, so as to
restore the premises to the condition in which I had found them.
Finally, samples of the sweep were fluxed by Martin Summers and
by Charles Hare, for the assay office.
24. And as the question whether the gold refined by me was adapted
for the coining operations had been raised, I proceeded to settle it by
an actual trial of part of each lot; which, having been alloyed by Martin Summers and cast into ingots, the trial of these was conducted by
myself, concurrently with the foreman of the coining department,
George Eckfeldt, who was authorized to take charge of it by the director of the mint. The gold was found to be of superior quality for
coining; double eagles were made of it, to test the perfection of impressions stamped upon it; and gold dollars, to ascertain how well it would
work in rolling. One of the strips for gold dollars, at my request, was
rolled again and again, the rolls being screwed closer together each
time, and until the men informed me that they could not screw them
any tighter, nor make the gold strip any thinner. This very severe test
did' not cause the slightest injury, or reveal any imperfection in the
gold; one more severe could not probably have been contrived.
25 xlad I been permitted to refine the $750,000 as I had expected,
I should have used the large reverboratory or cupelling furnace which




1 had constructed in the basement for melting the gold when refined; but
the stopping of my work prevented me from making the use of it I had
intended. For the same reason, large quantities of acid, which I had
received and designed to use, and which had been charged to the
account of my operations, were, in such part as was suitable for the
usual work of the mint, returned and deducted, and in such other
part as was too much diluted, poured away into the precipitating vats.
26. It remains only that I should present the facts relative to the
materials and labor employed by me, the apparent wastage which occurred in my experiments, and the matters of account connected therewith.
There were in the first lot 346.12 gross ounces of gold bullion, of
which 42.88 ounces were returned without being refined, as gold which
had solidified in the crucible, leaving a balance of 303.24 ounces to be
refined; in the second lot, 5,911.78 ounces were refined; and in the
third lot, there were 7,874.05 ounces, making the aggregate gross
weight of 14,089.07 ounces of bullion-upon which the mint charges
for separation were, at the rate of five cents per ounce, $704 45.
There were used by me in refining or separating these 14,089 ounces
of bullion:
2260 lbs. of zinc, a 4c.                                90 40
6245 lbs. of sulphuric acid, a 2c. -  -    -      -   124 90
1873 lbs. of nitric acid, a 7tc.   -  -    -      -   133 45
$348 75
The quantity of nitric acid was largely in excess, and when my
operations were interrupted, much thereof had to be poured away as I
have already mentioned.
It was not possible to know with accuracy the amount of labor actually employed, for men were often in attendance, though not at
work. Mr. Monell estimated their time at six days, of six men, and so
reported to the director; but at my request, prompted by my desire to
defray all expenses, he added to this estimate one third, and stated the
account of wages for six men during eight days, at $1 80-making
$86 40; which the director approved.
The fuel, crucibles, borax, &c., of the refining operations proper,
probably did not cost more than ten or twenty dollars. It would be,
perhaps, a close approximation to estimate the actual cost of the refining of 14,000 ounces of gold bullion in my work to have been about
$420, or three cents per ounce; which rate, however, would be much
reduced by economizing the acid, zinc, labor, &c., and by working
on large quantities in succession, through a long term.
But by referring to the accompanying accounts of materials and
labor, based upon the reports of Messrs. Monell and Porter, and furnished to me by the director of the mint-for copies of which see Nos.
23 and 24 of the Appendix-it will appear that my operations are




charged with $395 71 for acids, labor, &c., and $198 33 for zinc,'fuel, crucibles, fluxes, &c.-making an aggregate charge of $594 04;
which being deducted from $704 45, the sum paid to the mnint by the depositors for refining said bullion, leaves a balance in favor of my operations of $110 41 for economy in materials, &c.
27. In explanation of the above excessive expense of materials,
&c., $594 04, I submit, that being deprived of the separating apparatus, with which I designed and expected to have refined all the
gold in my hands, I was compelled subsequently to prosecute my
work by the laborious and imperfect mode of refining by fire, which
increased both the expense and the wastage of my operations.
28. In relation to the apparent wastage of my work, according to
my computations-see Nos. 25, 26, and 27 of the Appendix —there was:
Gold received.  Gold returned.  Appar't wastage.
Standard ounces.   Standard ounces.  Ounces.
In lot No. 1         340.543         340.102        0.441
In lot No. 2    -    5,822.609     5,807.448       15.161
In lot No. 3        7,751.820      7,745.816        6.004
13,914.972     13,893,366       21.606
The ratio of 21.606 to 13,914.972 being 0.0015, nearly, the rate of
said apparent wastage was about one ounce and a half per thousanda rate slightly exceeding the half of 0.0028, the most favorable result
obtained by Mr. Booth, as shown by an experiment not attended with
accident, and reported by the late director, in his letter of March 27,
1851, to W. L. Hodge, acting Secretary of the Treasury.
29. Of the gold returned by me, as belonging to lot No. 1, there
were in grains 3.53 gross ounces, which were delivered to the director,
with the request that he would give orders to Mr. Porter to melt them
for assay. In melting these grains, the crucible broke, and they went
into the fire. In my computation they are assumed to have been of
standard fineness, or 900 thousandths, and it is improbable that they
were of a quality inferior to this estimate, as they were chiefly grains
from melting fine gold.
30. The returns of lot No. 2, exhibiting the deficit of 15.161 out of
5,822.609 standard ounces, show that the accidents which happened
to this lot, to wit, the metal having been spilled in the cellar, and the
scoop of grains heedlessly displaced, probably caused a considerable
increase of apparent wastage.
31. The third lot was the only one which was free from accidents,
and it alone, therefore, furnishes data for an opinion concerning the
question of the probable wastage of the zinc method of refining. The
foregoing results show that of 7,751.82 ounces of standard gold 6.004
ounces were apparently lost. The ratio of this wastage is 0.00077, or
nearly three-fourths of one-thousandth. Had I not been deprived of
the separating apparatus, and thereby consequently compelled to refine




13
gold by fire, which I would otherwise have refined with acids, the
amount of the wastage, upon this third lot, would certainly have appeared less; making proper allowance, therefore, for this circumstance,
and for effects of variation in the relative quantities operated upon, we
may come to a probable and satisfactory conclusion upon this subject.
32. In pursuance of the original recommendation of the, director of
the mint, adopted by the Department, and assented to by me, an account was to be stated in which the difference between the actual
wastage in my operations, and the ordinary wastage that would attend
the refining of a like quantity of gold by the method in use at the
mint, was to be charged.
And in my prefixed letter to the Department, of November 13,
1851, it was stipulated that the rate bf said ordinary wastage should
be preliminarily determined, by the director of the mint and myself.
Soon after going to the mint, I brought this matter to the attention of
the director, but as there are no accounts kept in the mint which would
show what is the actual wastage of the refining operations there con-.ducted, it was desired and proposed by the director that he should
cause an experiment to be carefully performed, by the workmen of the
melting department, under the direction or superintendence of Professor Booth, with the view of determining said wastage. To this proposition I freely consented.
33. That experiment was, therefore, tried with the following result:
Ounces.    Fineness.
Deposit No. 656. Gross wt.    1,462.39  a    887    1,441.265
657.'"           1,399.65  a    880    1,368.547
655.    s            794.50  a    880      776.847
3,586.659
Wt. of refined bars No. 13.   1,557.09  a    893.8  1,546.363
" ( "  "    14.      2,037.36  a    898.5  2,033.964
Wt. of lump from grains from granulations of gold and silver    21.44  a    225        5.360
Bal. of grs.                      3.17  a    625        2.201
3,587.888
Gain      -      -          1.229
The seenling gain of 1.229 ounces, exhibited by this operation of
Professor Booth, being, like that exhibited by one of his experiments
previously made at the request of Director Patterson, an impossibility-, further experiments were not made. The apparent gain could
not be accounted for by supposing gold to have been left in the furnace, for it was one of those which had just been rebuilt, and could
not have contained gold.




14
34. But the director thought the result might be explained by the
practice of the assay department, of deducting from the actual assay,
and not reporting to the credit of the depositors, the fractions of a
thousandth less than one-half.  This suggestion, however, would
scarcely be admissible, unless such fractional deductions did, in the
particular instance, exceed half a thousandth of the whole; for they
should be adequate not only to annul the apparent gain, but to compensate such actual wastage as must have occurred.
35. As the experimental method of ascertaining the rate of the ordinary wastage of refining had resulted, in the hands of the melter
and refiner of the mint, in a failure; and as the acounts of that institution are not kept in such a manner as to exhibit said wastage, simple
data were wanting for the preliminary and conventional determination
thereof, by the director of the mint and myself, according to the
stipulation made in my letter of November 13, 1851, to the Department. Hence such determination was not made by us.
36. To permit me to investigate the subject of wastage more
thoroughly than the facts previously known to me, and derived from
my own experience, would have enabled me to do, I requested and
obtained, from the director, some facts relative to the wastage of Prof.
Booth, but other information, sought by me for the same purpose, has
not been obtained; if, therefore, in the discussion, which I shall now
present, there be any want of accuracy or completeness, I shall welcome the further investigation of the subject.
37. In the first place, I would refer to an experiment reported by the
late director of the mint, in his letter to the Department, May 9th, 1851,
as having, in his belief, shown that of 888.176 ounces of pure gold
887.643 ounces were returned, and 0.533 was apparently lost in the
operation of separating by the usual method of granulating with silver.
This is at least an admission, on the part of said director, that a seeming wastage of "'-ths of an ounce per thousand" was by him considered a proper and close return, from an operation by the old method,
conducted by skilful workmen familiar with every manipulation pertaining to the same, and furnished with apparatus perfected in every
particular by practical and great experience in the use thereof. With
this result I might be content to compare that of my third operation,
which exhibits a loss of three-fourths of an ounce per thousand. And
it will compare advantageously with the experiment reported by said
director, if proper allowance be made for provisional adaptation of apparatus not designed for the process, for the inexperience of workmen
in the use of my method, and for the necessity entailed on me of resorting to the use of refining by fire to finish my work, after it was excluded from the separating apparatus. But the want of sagacity and
care, which characterizes the experiments made in the mint by said
director, to test the comparative merits of the two methods of refining,
render them an inadmissible basis for a definitive conclusion, and demand that other data be brought to bear upon the question.
38. During the period I held the office of melter and refiner of the




15
mint in Philadephia, my adjusted accounts show the following gold
wastage:
From May 26th to Dec. 31, 1846, on  101,120.023 standard ounces   46.446 ounces.
Do. Jan. 1st   do.   1847, on 1,183,565.104  do.      322.998 do.
Do.  do.    do.   1848, on  272,626.439     do.       111.660 do.
Do.  do.  to Nov. 30, 1849, on  672,586.981  do.      238.823 do.
2,229,898.547            719.927
39. This apparent wastage differs from  the actual in the followingrespects:
First. It was, as it still is, the practice of the assay office of the
mint not to report fractions of a thousandth in fineness, less than a half,
for the credit of depositors, and debit of the melter and refiner; the
quantity of gold delivered to the melter and refiner was, therefore,
greater than that with which they charged him in account-to the ex-tent of the average of such fractions-say, two tenths of a thousandths
0.0002; except during the year 1847, when the work of the mint was
chiefly that of recoining sovereigns, napoleons, and other gold coins.
Rejecting this year, the above results should be increased by the sum of
209.266-being the two-tenths of 2.229.898 —less the two-tenths of 1,183,565.104; adding, therefore, 209.266 to 719.927, we get 929.193
ounces wastage; the ratio of which to the gold melted is about 0.00042,
or one-fifth of the wastage limited by law.
40. Secondly. The grains and sweeps of the deposite mneltings,.
which were then made in the furnaces of the melter and refiner, went
to the credit of his account without a corresponding charge, and to
their full extent further masked his wastage. If we take the year
1849 alone, the only year of my refining California gold, and add twotenths of a thousandth, of 672,586.981, being 134.517, to 238.823, the
wastage would be 373.340 ounces. The ratio of which is 0.00055,
or between five and six-tenths of a thousandth, to be increased, however, to the amount of the grains and sweeps from the deposite meltings.
41. The value of the grains, &c., from deposite meltings, in charge
of the assayer, deposited to the credit of the treasurer, for the use of the
contingent fund, were, according to a memorandum furnished to me by
the director, as follows:
1850, February 22      -              - -   $2,520 48
C  May         4      -              -    3,717 21
"   June      22      -      -       -    4,717 32
August  29       -      -       -    5,063 24
"   October   3       -      -       -    6,493 64
1851, March   31       -       -      -   10,699 31
"'    June  30        -      -       -   13,539 70
$46,750 90
These $46,750 90 are equal to 2,512.861 standard ounces of gold.




16
42. And as the quantity of gold operated upon by the melter and
Irefiner from December, 1849, to July, 1851, as exhibited by his adjusted
accounts, was 5,599,183.564 ounces, the ratio of 2, 512.b61 to which
is about 0.00045.
Therefore, if the deposite meltings, during the period that I was
melter and refiner, were conducted with care and skill like that which
is now exercised, my gold wastage account must have been masked to the
extent of 0.00045, by grains from the deposite meltings, then always
made in my furnaces; so that my gold wastage of 1849 would be as
follows:
Ratio of 238.823 to 671,586.981 -                          0.00035
Add 0.0002 not reported by assayer     -       -      -   0.00020
Add 0.00045 grains from deposites      -       -      -   0.00045
0.00100
And as in this estimate there is no account taken of the sweeps, from
the deposite meltings, delivered then without charge to the melter and
refiner, as is still the practice, it follows that my actual gold wastage
for 1849 could not probably have fallen below, if it did not exceed,
one-thousandth.
43. To determine the effect upon the apparent wastage of the rmelter
and refiner of the sweeps delivered to him without charge from the deposite meltings, we have the following data:
The gold wastage of James C. Booth, melter and refiner, exhibited
in his accounts, is, according to a memorandum furnished to me by the
director:
From Dec. 1, 1849, to Dec. 1, 1850, of 3,084,378.210 ounces.........  688.773 ounces.
Jan. 1, 1850, to July 19, 1851, of 2,514,805.354 ".........  635,167  "
5,599,183.564          1,323.940
The sweeps credited to his account were, according to another memorandum similarly furnished:
1850, May   9, by sweeps  71.100 ounces.
Sept. 30,'"        496.796
"  Dec. 31,    "          782. 92   "
1851, June 30,   I' 1,075.197   "
2,425.885 value $45,132-7 17]
As new crucibles are used when gold is melted for assaying, the
quantity of metal absorbed or imbibed by the pores of these crucibles,
and which goes with them into the sweeps, must be greater than the
quantity subsequently absorbed when the gold is melted in the refining
department, in a crucible which may have been employed for many
repeated meltings, and the pores of which have become saturated. Now,
as the gold is melted three times in the successive operations of granu



17
lating, toughening, and ingot casting, we may fairly assume that of all
the gold sweeps, one-fourth are due to the deposite melting. The onefourth of 2,425.885 ounces is 606.471; the ratio of which to 5,599,183.564
is 0.0001 nearly, which is, therefore, the increment or correction to be
added to the apparent gold wastage of the melter and refiner; to free it
from the masking effect of sweeps from deposite meltings, delivered to
him without charge.
44. The ratio of the wastage, 1,323.940, exhibited, as aforesaid,
by the accounts of J. C. Booth to 5,599,183.564, the ntumber of
ounces charged as having been delivered to him, is 0.000236; to which
add 0.0001, the correction for sweeps fiom the meltings of deposites,
and we obtain 0.00033, the apparent rate of his wastage.  Add, therefore, to this 0.0002, the average of fractional deductions not reported
by the assayer to the credit of the depositors, and we have 0.00053,
as the probable rate of the actual gold wastage of the melter and refiner during the year 1850 and the first half of 1851.
45. It is very probable that his exceedingly heavy operations in the
years 1850 and 1851 may have reduced the wastage considerably below the rate which would have attended smaller workings; for larger
quantities expose less surface, proportionally, to loss, by infiltration into
the pores of the crucibles.
46. To the assumption, that one-fourth of all the sweeps belong to
the deposite meltings, it might be objected that the melting of clippings is another of the operations of the melting department, in which
sweeps are produced.  This, however, may be disregarded, as the following data will prove.
The proportion of clippings returned from ingots delivered was, as
exhibited in my adjusted accounts:
Ounces of clippings.  Ounces of ingots.
In 1846.   -        -      -    527.000        1,466,729.90
In 1847       -      -       -    482.000        1,336,663.00
In 1848       -       -      -    211.000          613,273.60
1,220.000       3,416,666.50
The ratio of these numbers is 0.35707.  And, as clippings result
from ingots made from clippings, it follows that the metal is again and
again, in part, returned, and the clippings from any given quantity of
bullion will be expressed by an infinite series,.of which the ratio is
0.35707.  If we represent this ratio by r, and suppose 1,000 ounces
to be'the original quantity of bullion,
1,000 (i I  )    1.503
will be the expression of the series, and 553 ounces the sum of the
clippings produced.  One-half of all the bullion deposited is, therefore, the approximate aggregate of the successive clipping meltings.
2




And admitting that this work is an element to be considered, then, as
the meltings for assay of deposites are, to those of the melting department, as one to three and a half, or as 2 to 7, we must allow twoninths instead of one-fourth of the sweeps to belong to the deposite
meltings; and 539.085 ounces will be the correction to be made instead of 606.781 ounces, as above. The ratio of 539.085 ounces to
5,599,183.564 is 0.000096, a fraction differing so little from 0.0001 as.
to establish the truth of the assertion, that it is immaterial whether or
not we take into consideration the clipping meltings.
47. During the year 1847, the gold bullion deposited at the Philadelphia mint consisted chiefly of sovereigns, napoleons, and other European coins; these were generally received by the treasurer and delivered to the melter and refiner without actual assay. The apparent
wastage of that year milust therefore have been comparatively free frolm
the masking effect of the fractional deductions made in the assay office,,
and from that caused by the grains and sweeps from the meltings of
deposites. The quantity of gold charged to me for that year having
been, as above stated in section 38, 1,183,565.104 ounces, and the
apparent wastage, 322.998 ounces, the ratio of these numbers, or of
said apparent wastage, is 0.00027. Yet even this ratio is masked, to
the extent of the effect of said deductions and additions, from the
meltings and assays of all such deposites as inay have been actually
assayed. If we add to it 0.0001 for sweeps from deposites, 0.00045
for grains therefrom, and 0.0002 for deductions of assay, we obtain
0.00102, as a probable actual wastage of ordinary work.
48. Although I have demonstrated, by the above reasoning, that the
actual gold wastage of the melting and refining department of the mint
probably amounted to about one ounce per thousand, previously to the
recent heavy refinings of very large quantities of California gold, and
that these have been attended with a wastage of rather more than onehalf of an ounce per thousand; and, although the aforesaid experiment, reported by the late director in his letter of May 9th. 1851,
gives six-tenths of an ounce per thousand, as, in his opinion, the
wastage of an operation by the method employed in the mint; yet, in
conformity with the course I have uniformly observed, in all matters
involving pecuniary questions arising in my proceedings, to adopt
the view most favorable to the mint, I have claimed in my statement of the account of my workings an allowance or credit for wastage, at the rate of only 0.00033, or one-third of an ounce per thousand; the same being, as mentioned in section 44, the apparent
rate of gold wastage of the melter and refiner for the year 1850, and
one half of the year 1851, corrected for sweeps from deposite meltings
delivered to him without charge, but left masked by the usual fractional
deductions made in the assay office from deposites. Mlly operations
may therefore be debited in account with the aforesaid apparent wastage of 21.606 ounces of standard gold, value $401 97-see section
28; and credited with 4.578 ounces of standard gold, value $85.17;
wNhich is an allowance at the aforesaid rate of 0.00033 upon 13,873.092




19
ounces, or, upon the whole amount of standard gold delivered to me,
13,914.972 ounces, less 41.88 ounces, contained in 42.88 gross ounces,
or the lump of lot No. 1, which solidified as above mentioned-see
sections 6 and 26, and No. 25 of the Appendix —and was therefore
returnled without being subjected to the refining process.
49. Under an equitable view of my agreement with the Department,
I might be considered free from obligation to make good an inordinate
apparent wastage, caused by accidental spilling of metal; for, although
displaced and scattered thereby, it would be subsequently recoverable;
and, therefore, may not be finally lost to the mint. And as I was
very unexpectedly interrupted in my work, though for considerations
alleged to be founded on the probable public obligations of the mint, I
might reasonably claim  to have been thereby absolved from liability
for such wastage; yet.1 have preferred to admit that liability to the
fullest extent, and in the statement which I have made to credit every
debateable matter, although more than I believed could be justly demanded of Ine.
50. But in so doing, I have not designed to preclude myself from
discussing the comparative merits and wastage of the two methods of
refining in question, with the most rigid scrutiny and thoroughness;
nor from a further investigation thereof, based upon data, or information not now possessed by me, but which may be acquired or received.
51. With reference to the comparative wastage of silver by the two
methods of refining argentiferous gold, it was conceded by the director
of the mint that my method, as it dispenses with silver and substitutes
zinc for quartation, must save all the wastage to vwhich the silver added
in the old method is necessarily exposed.
52. And as the weight of silver required would have been 28,178
ounces for the 14,089 gross ounces of gold bullion refined by me, if used
in the proportion of 2 to 1, now practised in the mint; it was, consequently, conceded by the director that my operations are entitled to an allowance or credit for silver wastage avoided or saved by them, upon 28,178
ounces. But, as it was deemed impracticable, both by the director
and myself, readily to determine, by'experiment, the rate of said silver
wastage, it was agreed that-as refining, which comprises not only the
melting, but also the solution in acid, of the silver employed, cannot
be less, and must certainly be more, wasteful than the simple melting
thereof-I would be fully entitled to claim for my operations an allowance or a credit, according to the average rate of silver wastage, exhibited by the adjusted accounts of the melter and refiner, upon silver
bullion delivered to him and melted into ingots for coining.
53. To ascertain said average rate of silver wastage, reference must
be miade to the adjusted accounts. Now, those of my predecessor,
Dr. J. R. McClintock, show the following allowances for silver wastage:




20
For 1839, on 2,088,098 ounces 2,727.8 ounces.
" 1840, on 1,483,374   "   1,120.8   "
" 1841, on   814,694' "      390.6   "
" 1842, on 2,062,412   "    981.2'
1843, on 3,340,513   "   3,301.1
~' 1484, on 1,375,485   "      628.9   "
11,164,576        9,150.4
Upon the remaining silver workings by Dr. McClintock, during the
year 1845 and part of 1846, his adjusted accounts do not show any allowances for silver wastage.
54. During the whole period of his tenure of office, he never claim-:ed or received an allowance for gold wastage. And when he finally
settled his account with the treasurer of the mint, in May, 1846, he
paid to that officer the following surplus over the amount charged to
him in account:
In gold  -   -    - 84,943 71
In silver -       -  2,172 98
$7,116 69
55. These facts, that the melter and refiner of the mint had not required any allowance for gold wastage, nor any for silver wastage during the last year and a quarter of his official term, and that a surplus
of $7,116.69 had accumulated in his hands, are explained by the
practice which had been followed of sequestrating sums of silver and
gold, when the amount of either contained in any deposite of the other
was less than five dollars, after deducting charges for refining, and for
which sums they did not allow any credit to the depositor, nor make
any debit in the account of the melter and refiner.
56. This practice of sequestration is still followed-but tile bullion
now so sequestrated is charged ip account to the melter and refiner;
yet the depositor is not paid for it.
57. The aforesaid modification was made a few months after I becamle melter and refiner of-the Lint, and was designed to prevent such
accumulations of surplus thereafter.
58. During the years 1846 to 1849, there were sequestrated from de
posites, in sums which would be less in value after deducting charges
than five dollars each, charged to me in a petty account kept for the
purpose in the treasurer's office, and by me returned to the account of
profit and loss, and to the augmentation of the contingent fund of the
mint:
In 1846, of silver 319.20 ounces standard, or $371 43
In 1847,  do.  149.56        do.      or   174 03
In 1848,  do.  995.05.       do.      or 1,158 92
In 1848, of gold  28.07      do.      or   522.23
$2,'226 61




59. By a memorandum furnished to me by the director of the mint, it
appears that the following sequestrations of silver have also been
made:
1850, March 30, parted for the mint  3,186.747 ounces.
"  June  29,        do.         3,965.158  do.:  Sept. 30,        do.         3,507.700  do.
"  Oct.  31,        do.          4,055.390  do.
"   Dec. 31,        do.         5,605.290  do.
1851, March 31,       do.        29,960.750  do.
"  June  30,        do.         15,783.560  do.
66,064.595 ounces.
The value of these 66,064.595 ounces is.$76,875.16, which sum has
doubtless been passed to the contingent fund of the mint.
60. The above facts serve to show how completely the wastage of
the melter and refiner must formerly have been masked by deliveries to
him, without charge, of bullion sequestrated in sums less than five
dollars in value, and in conformity with a practice supposed to be
authorized by, and founded upon, a strained interpretation of the meaning of the word "advantageously," used in the proviso to section 14
of an act of Congress, approved January 18th, 1837, taken in connexion with the power given by section 18 of the same act, and the
appropriating clause for contingent expenses of the mint, therein conained.
61. Notwithstanding the aforesaid deliveries of sequestrated bullion
without charge, it appears that for the six years, beginning with 1839
and ending with 1844, the meelter and refiner received allowances for
silver wastage amounting to 9,150.4 ounces, on 11,164,576 ounces,
charged as delivered to him. And his apparent silver wastage, masked
though it must have been to a considerable degree, was, therefore, for
the period aforesaid, in the ratio of those numbers, or 0.00082 nearly.
62. While I was melter and refiner of the mint, the apparent silver
wastage, as exhibited in my adjusted accounts, was:
Ounces.       Ounces.
From lMay 26, to Dec., 31, 1846, on    1,477,253.000   1,292.552
Jan. 1,            1847, on    1,353,111.599     938.599
Jan. 1,    "       1848, on      633,198.260   1,1721397
Jan. 1,  Nov., 30, 1S49, on    1,213,957.943      82.043
4,677,520.802   3,486.591
The ratio of these sums to each other is 0.000745, or very nearly
three-fourths of an ounce per thousand. But from May 26th to Oct.
1st, 1846, the sequestrated silver was delivered to me, as it had been
to my predecessor, without charge; so that the above apparent wastage of
0.000745, is masked thereby to some extent. After October 1st,




22
1846, a petty account was kept of such silver, in which I was charged
with its amount, and the silver wastage of my regular accounts became
actual instead of apparent.
63. In explanation of the great disparity of the wastages allowed
me for the years 1848 and 1849, respectively, it should be mentioned
that there are in the cellar of the mint a number of sinks, and a deep,
well, designed to collect the metal carried off by the water used for
washing grains and sweeps. They were cleaned out in 1849 when I
resigned my office, and the silver contained in the dirt taken therefrom
greatly reduced my apparent wastage for said year. That dirt had
accumulated frolm the spring of 1846 to November, 1849.
64. The adjusted accounts of James C. Booth, melter and refiner,
exhibit, as sil-ver wastage:
Ounces.     Ounces.
From Dec. 1 1S49, to Sept. 30, 1850, on  771,207.306  1,193.159
Oct. 1, 150, to  July 19, 1851, on  601,255.940    388.791
1,372,463.246  1,5S1.950
The ratio of whiclk apparent wastage is 0.00114, or 1- ounce per
thousand.'65. Since the work of the melter and refiner became, in 1S49, and
has continued to be, chiefly that of refining gold brought from California, a much larger proportion than was formerly required and employed of the silver bullion fund kept there on deposit by the Secretary
of the Treasury, has been used as material for refining argentiferous
gold; the silver bullion being successively melted and remelted with
half of its weight of the gold in the operation, technically called
quartation, which is one step in the process ordinarily used at the
mint for the parting or separation of silver from gold.
66. To protect the silver bullion account of the melter and refiner
from an apparent wastage exceeding that allowed by law, the following
practice was therefore adopted, shortly after Professor Booth came into
office, and is still pursued.  Depositors of California gold bullion are
charged with two per cent. of silver alloy for gold coins, not that so
much silver is actually put into gold coins as alloy, nor that it is desirable to use such a proportion for alloy, but because it is not practicable, by the method of refining now employed in the mint, to extract
all of the silver originally in such gold.
67. Of the 11 or 12 per cent. of silver, by weight, which California
gold usually contains, the process employed leaves unextracted from
1 to 2 per cent., or perhaps, on an average 1-2 per cent. Hence
depositors are charged with two per cent., and this is credited to the
silver account of the melter and refiner; the difference between 2 per
cent. allowed to him, and 1- per cent., the average left in the gold,
gives him the margin of one-third of one per cent. to mask his actual
silver wastage.




23
68. It would, however, I believe, be impossible to determine by
-any reasoning upon the data known to me, what has probably been
the actual silver wastage of the present melter and refiner; for the
reason that, from November 14, 1850, to April 1, 1851, the mint could
not perform the work required of it; and it consequently happened
that large quantities of California gold were coined, without having
been duly subjected to the parting process for the separation of the
silver contained therein; and that to compensate the heavy loss of
silver thus produced, the value of five per cent., by weight, of silver
was charged as alloy to the depositors of gold bullion, amounting to
the sum of $42,759 84, as is exhibited by the annexed abstract from
the adjusted accounts of the mint, (see No. 28 of the Append'x;) and
that this five per cent. of silver, if not more, was left in the gold coins
by the melter and refiner, appears by the following memorandum of
credits allowed to himn in account furnished to me by the director:
Ounces.
1849, Dec. 31, by silver used for the alloying otgold coins   484.911
1850, March 30,     "       i       "      "        32,723.450
June 29,;    6,824.632
Sept. 30,      i       ~    7,354.380
Oct. 31,                                       7,911.570
Dec. 31,                                       9,127.330
1851, Mar. 31,      "'      "   45,450.000
June 30,       "'"                      10,312.500
120,188.773
And as the value of these 120,188.773 ounces of silver, if standard, would be $139,856 02, this sum was lost to depositors and the
country.
B3ut whatever may have been the actual silver wastage of Mr. Booth,
it certainly was equal to the aforesaid credits for wastage allowed to
him, and amounting to 1581.95 ounces upon 1,372,463.246 ounces,
charged as having been delivered to him; or the rate thereof must have
been at least 0.00114, or 1}- ounce per thousand, and it did probably
exceed this. See section 64.
69. From the above reasoning it appears that my own apparent.
wastage, amounting to very nearly three-fourths of an ounce per thousand, is the least rate given by any of the silver workings of the mint;
and, conforming to my purpose concerning pecuniary matters in the
statement of my operations, to'adopt those probable rates which are
most favorable to the mint) I have in said statement claimed the
allowance of only 21 ounces of silver for wastage, upon 28,178 ounces;
being at the rate nearly of three-fourths of an ounce per thousand-which
would have attended workings by the old method, but was avoided in
the workings by my method; and, as the silver used for granulation
in the mint is of a fineness usually exceeding 990 thousandths, the
value of said 21 ounces is 26.8S dollars.




24
70. The aggregate gross weight of bars Nos. 1, 2, 3, of lot No. 1, and
bars Nos. 1 to IS, of lot No. 2, being 5397.64 ounces, and the standard
gold contained therein being 5935.442 ounces-see Nos. 25 and 26of the
Appendix-it follows that the average fineness thereof was 989.6 nearly;
and assuming the fineness, which would have been obtained if this
gold had been refined by the usual method, to be 983, I am entitled to
claim for silver extracted by my process, and which would not have been
by that usually employed, a credit in account, of 6.6 oz. per thousand,
or two-thirds of one per cent. upon the aforesaid 5397.64 ounces. But,
as 563.79 ounces, bars No. 3, of lot No. 3, were only of the fineness
978. l-see Nos. 28 and 32 of the Appendix-although this inferiority was
probabir due rather to iron derived from the plumbago crucible than to
silver left in the gold, 1 have deducted 563.79 from said 5397.64 ounces,
and upon the remaining 4833.85 ounces have claimed credit in silver at the
rate of one-half of one per cent., amounting to 24.16 oz. of pure silver,
worth at 129 cents $31 16. This rate of one-half per cent. being substituted for that of two-thirds, in further pursuance of my purpose to
concede part of allowances that, in pecuniary questions, I might justly
claim from the mint.
The statement of mlly workings is, therefore, made as follows:
Dr.
To materials, &c., as per memorandum of Mr. Monell -  $395.91
To materials, &c., as per memorandum of Mr. Porter  -    198.33
To apparent gold wast tge of 21.606 standard ounces    -    401.97
$996.21
Cr.
By refining 14,089 ounces of gold bullion at 5 cents per
ounce -.-                      704.45By assumed gold wastage at 0.00033 on 13,873 standard
ounces, 4.578 ounces, value  -    -      -      -      5.17
By assumed saving of silver at: of an ounce per 1,000 on
28,000 ounces, or 21 ounces at 990 fineness, value    -  26.88S
By saving of silver extracted, which would not have been
by the method used in the mint, at the assumed rate of
-- per cent. on 4833 ounces, or 24.16 ounces, value at
129 cents per ounce   -    -      -      -      -     31.16
By balance required to settle this account  -     -    148.55
$996.21
71. And I have caused a suml of money, exceeding the amount of
the balance above stated, to be delivered to the director of the mint,
that he may apply the same, or so much thereof as he shall find requi



25
site, to restore to the gold bullion, charged to the account of the melter
and refiner, any excess of apparent wastage which may be supposed to
have been occasioned by my operations. Notwithstanding that the said
excess was caused, as aforesaid, only by palpable accidents, to which
my method of refining is not more liable than any other; and that the
interruption of my proceedings by the director might be justly deemed
to have equitably absolved me from pecuniary liability for such accidents: especially, in view of the groundless apprehension expressed by
the director, that the gold, which I had refined, might not be suitable
for coining, and his consequent unwillingness to permit me to refine
a further sum of $750,000, although this would have been accomplished sooner by my process than could have been done by the old
process; and of the fact, that I was thereby deprived of the benefit of
the saving, which would have enured to my workings if that needless
interruption had not occurred.
And I may here remark, that if. the accidents had not happened,
whicrh occurred in the working of lots Nos. 1 and 2, and the apparent
wastage upon them  had consequently been at the same rate as that
exhibited by the working of lot No. 3, to wit, three-fourths of an
ounce per thousand; then, upon the 6121 standard ounces refined
of said lots, the apparent wastage would have been 4.71 instead of
15.60 standard ounces, making a difference of 10.89 ounces, worth
$202.60. And instead of the above stated balance of $148.55 against
my workings, there would have been $54.05 in their favor.
72. With reference to matters of account relative to my refining
operations, the reputed fineness of bullion delivered and returned are
by me accepted, as if the same were mathematically exact.  But with
regard to the question of the comparative inherent wastage of my
method of refining gold, the degree of accuracy of the assays made
in connexion with my operations is an element to be considered and
fairly discussed. It will not, I presume, for it cannot be truthfully,
claimed that assays made by even the most skilful and faithful assayers
are absolutely correct. The gentleman who holds the office of assayer of the mint, J. R. Eckfeldt, esq., possesses not only a familiar
knowledge of all the details of assaying, acquired by intelligent, practical experience, during many years, but also the qualifications of a
calm  physical temperament, a steady hand, and a quick eye, each of
which is requisite for the extremely delicate manipulations employed.
That he is, therefore, an assayer of uncommon skill is certain; yet,
repeatedly, have I heard this gentleman avow his belief, that the results of the best gold assays are uncertain to the extent of 0.0002, and
that greater accuracy cannot be ascribed to them.
73. During the three years and a half that I was melter and refiner of
the mint, the synthetical operations of the melting and refining department were a constant and most rigid check upon the analytical results
of the assay office. The gold assays were then made by Mr. Eckfeldt
himself, and their uniform  accuracy gave proof of his great skill, and
of his conscientious performance of duties often very laborious. But'




26
since the quantities of California gold bullion received have so greatly
expanded the work of the mnint, it has been found not to be practicable
for the assayer actually to make all the assays required; and several
young assistants have consequently been employed to make assays uinder his superintendence. Implicit as is my confidence, founded upon
knowledge, in his own skill, and conscientious as I believe him to be,
in all that pertains to the duties and work of his office, I yet cannot extend like confidence to the work of young men, however faithfully
performed, who must be, comparatively with him, novices in the extremely delicate art of assaying.
74. If, therefore, Mr. EEckfeldt cannot claim, for his own gold assays,
an exactness within the limits of a probable error of 0.0002, the question, what degree of accuracy is to be ascribed to tlie work of his
young assistants, is one which, in discussing the comparative wastage
of two methods of refining-as one of these has shown an apparent
wastage of 0.00077, and the other an apparent wastage of 0.0006may admit of the answer, that the limits of probable error extend beyond those of the matter under discussion.
It is true that, by multiplying assays and taking the mean or average
results, a less degree of improbability may be obtained; yet a number
of errors do not constitute truth; and work requiring extreme skill, but
which has not been performed by a workman known to possess that
qualification, lacks the only proper basis for confidence.
75. That the aforegoing remarks are both pertinent to, and called
for by, the facts concerning my refining operations, will appear from
the following results of the assays of gold bullion delivered to me.
(See Nos. 29, 30, and 31, of the Appendix.) First, as they were reported to the treasurer, and to the credit of the depositors thereof; and
secondly, as they were reported, when repeated for verification, before
said gold was operated upon by me:
Number of  Assay for    Repeated    Difference of assays.
deposite.   depositor.    assay.. Excess. Deficiency.
1,049      884         884.4      0.4
1,053      88          880        -         -
1,096      883.5       883.2      -         0.3
1,097      882        S81.4       -        0.6
1,098      880.5       880.8      0.3
1, 099     888         888.2      0.2
1,100      884         884.3      0.3
1,101      911         911.2      0.2
1,113      881.5       882        0.5
1,225      878.5       878.3      -         0.2
1 233      884         884.4      0.4
Sum   2.4      1.1  Mean 0.12
The fourth of the above results shows that in the assay of deposite
No. 1,097, a probable error of six-tenths of a thousandth; in favor of




27
the depositor and against the mint, may have been, and was probably,
made. And the third, fourth, and tenth results show that, notwithstanding the adoption of the rule to make fiactional deductions, deposites Nos. 1,096, 1,097, and 1,225, were received and credited to
the depositors as of fineness exceeding those subsequently found by assays of verification.
Hence it is evident, that I am fully entitled to assume that the process of assaying gold bullion, as performed in the mint, is attended
with an inherent and unavoidable degree of uncertainty, which, though
not exceeding very narrow limits, possibly 0.0002 as an average, does
yet attain in particular instances to 0.0006, or six-tenths of a thousandth. And in any investigation or experiments which may have
been, or shall be, made to determine the comparative merits of my own
method, and of the method now employed for separating argentiferous
gold bullion, the aforesaid degree of uncertainty in assaying should not
be disregarded.
76. The refined gold returned by me as belonging to lot No. 1, was
assayed, both for gold and silver, with the following results, reported by
the assayer to the director, and by him furnished to me:
Bar No. 1, weighing   9.85 ounces, 993. gold, 7. silver.
No. 2,    "      128.90   "    991.   "   6.   "
No. 3,'      128.81   "    991.4  "   5.6  "
Hence it appears that my method of refining, when an alloy of 2.
parts of zinc to i -of argentiferous gold was used, has been made to
extract, of the eleven or twelve per cent. of silver, contained in California gold, all except 5.6 thousandths, or about one-half per cent.;
and I amn confident that this result may be excelled.  I may also claimn
for my process-as is shown by the fineness of bars Nos. i to 18, of
lot No. 2-that, when zinc is used in the above proportion of tw\o and a
half to one of gold, it readily produces refined gold of 990 fineness, or
99 per cent.  And the returns of lot No. 3, in which the zinc was
used in the proportion of 2 to 1 of.the gold, show that the fineness of the
gold was then about 983, leaving, therefore, if we disregard base impurities, such as iron absorbed from black lead crucibles, about one and
two-thirds per cent. of silver in the gold.
77  The working results, therefore, verify the statement made in the
specification of my patent, that by using zinc in the proportion of'" two
to three times the weight of the gold bullion, the refined gold bars, if the
operations have been properly conducted, will be ductile and of a fineness varying from 98.5 to 99.5 per cent."
78. The black lead crucibles employed in my workings must have imparted some iron to all of the gold, except bar No. 1, of lot No. 1,
which was melted in a sand crucible, and is shown by the assay thereof
to have been only gold and silver; while the assays of bars Nos. 2 and
3, cast from melts made in crucibles of black lead or plumbago, indicate the presence of iron or other impurity.
79. By the silver quartation method of refining, when silver is used
in the proportion of 2 to 1 of gold, as is now done in the mint, the




28
average fineness of the gold obtained is, I believe, about 9S3; when the
silver is used in the proportion of 3 to 1, as was formerly the practice in
the mint, the gold is of an average fineness of 990; but the quantity and
expense of the work is then so much increased, that it is considered more
profitable, both for the mint and the depositors, to refine only to the
fineness 983, the cost of extracting the difference of silver being greater
than its value; fiom this defect of the old method my new method is
free.
S0. From November 14th, 1850, to April 1, 1851, the mint charged
depositors of gold bullion for silver alloy, at the rate of five per cent.,
$42,759 84, (see abstract, No. 28, of the Appendix;) of that sum lost
to said depositors and to the industry of our country, my method of refining would have saved $34,207.87, or four-fifths.
And from April 1st, 1851, to December 31st, 1851, it appears from
the same abstract that the mint charged for silver alloy, at the rate of
two per cent., $45,617 91, of which my method would have saved at
least $22,808 95, or one-half.
There was also charged to the depositors of gold bullion, see the
aforesaid abstract for separating or parting the silver therefrom, at the
rate of five cents per ounce, and of which my method would have saved
two-fifths:
Nov. 14, to Dec. 31, 1850, $13,498.26 charged, 5,399.30 saving.
Jan.  1, to Dec. 31, 1851, 110,409 37 charged, 44.163 75 saving.
$123,907.63        $49,563.05
If we add together these charges, and the portions thereof which my
method would have saved, we obtain the result-that of the aggregate
sum  of $212,285.38, charged to the depositors for parting and for
silver alloy, from November 14th, 1850, to December 31st, 1851, my
nethod of refining, if it had been employed, would have saved
$106,579.87, or about one half; and at the same time would have
caused the work of the mint to be done with much greater despatch,
and thereby also have saved much interest.
81. If the director of the mint had permitted me to refine the
$750,000, which I desired and expected to have operated upon, it
was my intention to have shown, and I am confident I would have so
done, that gold, in any quantity, granulated on Monday may be melted
into refined bars on Thursday; and this, without preventing a like
quantity from being granulated on Tuesday and melted into bars on Friday; while another like quantity may be refined during the interval
from Wednesday to Saturday; and so on continuously. The whole
work of recovering silver, used for granulation in the present method,
being dispensed with by the zinc process.
82. But as I was prevented from doing this, I will only add that,
in my opinion, a small expenditure for furnaces and improved apparatus adapted to my method, such as I have contrived for the purpose,
would render the capacity of the mint at Philadelphia adequate to the




refining of gold bullion at the rate of one million per day, and at a
cost for labor and mnaterials not exceeding about the one-half of that
incurred by the process now employed; and without subjecting the
workmen of the mint, and the inhabitants of its vicinity, to the injurious effects of such large quantities of noxious gases, as are incident
to the present method of refining by the use of silver for quartaation.
83. In conclusion, I submit, and ask to have it borne in mind, that
I have not wished to derive any benefit from  my patented process
of refining gold, without its superiority over the method now employed
in the U. S. mint, being first conclusively established, by a series of
large working operations, conducted and reported upon by skilful, careful, disinterested, impartial, and truthful persons; and that I would
not receive any measure of compensation, for the said right, that was
not founded upon and justified by its usefulness and value, so or otherxvise as satisfactorily established.
Very respectfully, your obedient servant,
RICHARD  S. McCULLOH.
WVashinltonz, Auguzst 3, 1 S52.




APPENDIX.
(1.)
PHILADELPHIA, Apr2il 27, 1852.
MY DEAR SIR: WXill you do mne the favor to reply to the following
questions:
1. In what capacity, and for how many years, were you employed
in the mint; and what were the services which you rendered me in
my recent refining operations?
2. What was the course of my proceedings, and what the results
shown by them relatively to the efficiency and economy of my modes
of granulating and refining gold bullion?
3. If you know of any difficulties or accidents which occurred in
my operations, what were they?
4. From what you witnessed of my mode of refining, what is your
opinion, as to its adaptation to the working of large quantities of metal
with economy and despatch, in comparison with the old method, now
used in the mint?
5. What do you believe to be the reason of the discrepancy between
the results from fluxing sweeps, obtained respectively by Mr. Hare, of
the assay office, and yourself.
Yours, very truly,
R. S. McCU1,LOH.
MnARTIN SUMMERS, esq.
(2.)
PHILADErLPHIA. April 29, 1S52.
Mr. McCULLOH.
DEAR SIR: In compliance with your request, I hasten to answer
the questions propounded by you to me, in your favor of the 27th instant; and, in doing so, it gives me much pleasure to give my opinion
of your method of refining gold.
I was employed in the mint for about twenty-seven years, and was
foreman in the melting and refining department, I believe, for twentythree years. I also worked in the adjusting room for about two years.
I aided you in your late experiments, first, by taking charge of the
granulations for you, as they were made, and seeing them properly
carried to the separating rooms; afterwards I melted the gold (when
refined) into bars; alloyed and made ingots for coining of some of them,
and then gathered the grains and refined them upon bone-ash tests for
you. I also fluxed samples of sweep.




.o.
t'1l.i:_ ti lhe  oth i   nl0of January,  you were'  ellpioyedi in constrluc ting
nivf:aceRL  and apparatus; afterwards withi. refilningll   andoi g'atiierinlg  grains,
The  tran-uitations  acide by your method wAere tar supertio     r   tI tlose
m1-iade in thle oltl taay, or by hand; being miuci smalleyr and tlierefore:moroe quickly andc thoroutghly  acted upon bL  t-he acids.  The labor,eqsu ired iS mullch less; and, as dipping is avoidect -thlere is no spilling
nf nmetal to procuce w   aste.  The  gold  refined  by  you, \with zinc,
wJas Ias gooCd as that refined with silver; it macde incgos for coining of
e best quiality, and it toughened with all ease.  I never saw  better
Sfod  -T oura!   t  mode of refining substitutes zinc for silver and sulphtulic
ac,   G,,' nitlric; which must, I believe, make it more econormical.
You had some cifficulty in getting the valve of your granulating pot
to- wViork rig'htly; and an accident happened in your second granulatio wn
wa\lti cth caused thie Imetal to fall on the floor of the cellar, and fly arounll',C some distance, upon. the walls and other objectso
I ami satisofied that your mode of working  is fu'r prefefable to that in.,use; that mucllh larger qiuantities of metal caln easily be workled by it,
w~vith less labo1r  and inl less rool, as well as   i Iless expense and
\.ase, T.    l   f-rni ace ac   ulsecd in fluxilng  sV.weep bf cod s lore dcIraught thlan
tai at ulsed  by MA!r. Heare; consequlently, the flux wans -norte f uid.  Theva,,e  a!l W  ei  hd be y   Mr. Hcle.
Yo'rl. nlOSI o'edient. servant,
MA _,r_.    S UAlt.i s,
Ds.- In - lnl  if: yo u rlecolect he couirse of mnty loat  procec i's i: 
o:h:e mliiilnt,  iease to staie   w hat io-y NI aee,   l  1 1 i  to Co witi:helim  and by  h7la ta au llority  y0ou acted.
2  If aid poceed ings Ihave causcei  you to k i'ohw,   c.i ar ole ine rit
c of mny mHet*loS   ot refining gold cwithl  zinct as co' upaped  with tos   of
1tie method ri use, in efficiency and economi Ly- p lease to  ae wbhat al
i    alte ficts so  nownI  tO you andt relative therelto
3D If ytou witn1essed  the operation of alloying thle gold with zinca
n1  thi then ga  uulating that alloy by lettinl  it How i  rectiy i -to wacateI
-i  tihe furnace I emnpioyed, please to state vwiet.nei the g'anulatitions.o nade  were atten led  with  any peiceptible volatilization oaf metal and.
it,7.l  mIore o; less wastage than if' made in -tee uisuald way;'and whether
L Ly  o dA ol     g;ranutlaiting is, in an lll  espect, ullpwerio  to that leretofore'i:_15'e ~ i,. If yo-u knaowt  C-f any accictdenl having  1befllen nmy experinlents,
ie pleased to stale yout knowledge thereof.
2. ift 1m5y aMode of condluctingi my process diffeled materially, fromt.hat enapaloyed  it the e. pemnents upoin retning wito  h zinc, previously,:rilerio 0med c  ti e mlint; please to state what th-e dii:cei-ence was, and
talt thle resieLts  ul0e tilereto,




ry' Ys),iL12_I   t_  thi   ti.ovs   nqJ   lis..   u'.:1 t  <sun.-7. 5 J|it-s *t             *;
yoru   wili ~iai:muh o1i5e y,i's 1 D t:i ~l           X;'u-'1
Ifibiu   it'' j 5   AD        <'A 
",uueA   r,     t. i  i.:, J   uIJ o-S' 4,1Th 1                                     BcS  
"'i   >s   ~~~~   5Xt~~~fl555  ~(''''?)       I        >10 I['
D   _-'. Sec  i.L', ij -r_ j 7, U,    -1'l  tl  t   l, l  l i'  t    1 t)  e,0  3 C e l  e 1i f
ofe   ve;  thv  tea             tiS "o n  aont Dv   i          7,:,. t:: 1i i!:"efledl a, 1  ail ( x il t)'~Om         t uoa.....r a old,:L, zinc   $:rsci, r-,.
011.          0         1'11;.'
id         at8       el            at hf0 maDeria 1 s   a        nd Shio LsidL ttc jt', P    15  1
of    ~'  ~                                                    tr  also hLi      cha'ra'c a";'oi  l
WIG wautain>.          ~nhit'51i0y  o  yr d er   of D:'  hlso'3.vtu~7lc:      -'e'-qr~t 1'                                       D i  IW''i$ qi' CD  ~l'',rssa tl L & |  u n  i t       I   ]e II C  1 e   i i vm the-   ei c s a   cI  ai -,,a -e  I s ni n. 
IH. C-.d.ct~',~I C'I. 1]e  gold             reined    by    ot tol.  *uin-eitc  irll'- aeC;' o.i
_o /ts  antdS W.I'c',', t3'v e   i:S td3q' 5,ti'5  o   fiae t*  IIold   yu, 3'' o'i'id toi)    d 1       ~'I,   aolii t l,I o2'       ln    i         r C> al  
ess; yoe e   uroci esae     ~s ni o re  eo'X(om       c at Itor,, a    nd fo    tess ou ntie
Of  wt h'12. i t CIL                                C., ~ 810tl a5e         Ut.   33?u  lil, 10  ^. 1.
BK''L....
of   i z nl*3 tinc2,?i an ieSd s pur atri s  FiO;'15}''ei    i ett! i   R-Tea   whicF cid'b  * J,'. il
d.es   eoo' Ite               attna, abou     t; one-,. ~ OU1'Y~   l~e8 ~Bt/    nil.1 I~, L0., t~~le: 6?:rtSC:     1 -,  t t? i u,-g  1,   i t 0   *...-, 5 -' —, |i,:.'int te    it7 Et.1  lEce,  a n           te ifi3    1Lli  J  i C.."11  1 v. e          U   D.   B 
IA) -.  ode,,-',? a'ra nu  ati.ag 1Ke    i vy: o      t     1o  a Ii i     I  1   i   i    _C
s 11ee1'. i. aeWOs de,.in  Ou'1 oc  i o  e    i i i;._!  1,  t
of  ZHIC al.1d      i-hul",- cn n  5:01:10 %d1 E: e-1  I:is   _ _ _,':.. gl PtCLi!.1i~];.
upoeng       -7ls:::_lr:   ~ 1                    - se cOn    il  at ea: oo   a I  1- i- th Oee
5P5, ct za~' ~'   Yo,.''   ~ C-.  AI4,,u?, C-d    en i':a'o,
SZ t i c t   ni O ) < i;, p,;,, uIt h,. 




33
1. What were my proceedings lately at the mint; what had you to
do with them, and under what authority did you assist me?
2. What facts do you know concerning the efficiency and merits of
my modes of granulating and refining gold with zinc?
3. Did you perceive any volatilization in the alloying and granulating; and if there was any difficulty, please to state what it was.
4. If you witnessed any accidents, what were they?
5. If you know any thing concerning gold obtained from the large
test furnace, torn down by my directions, please to state your knowledge.                    Yours, very truly,
R. S. McCULLOH.
Mr. ARCHIBALD PORTER.
\6.)
PHILADELPHIa, April 29th, 1852..
DEAR SIR: I will endeavor to give you the statement that you request, as near as I can recollect. You commenced by pulling down
the test furnace, that was in the cellar, and building a new one in its
place. You had a silver furnace taken down, and the other two repaired; you had your granulating furnace built in the place of the one
you had taken down.
You refined a sample of gold with zinc which I granulated; next,
you granulated several thousand ounces of gold with zinc, which you
refined, and then you gathered up your grains. As foreman of the
melting department, I gave you all the facilities you required, and assisted you in the granulating; I mnelted, stirred, and skimmed the
metal for you; I did so by orders of Dr. Eckert, the director.
Your way of granulating makes very uniform granulations, and it
appears to me to be attended with less loss than our -regular way of
granulating, so far as dipping is concerned. The gold refined by you
was good and tough, and fit for ingots.
I saw no volatilization. There was much difficulty in getting the valve
to work right at first, but you had perfect control of the horizontal one.
There were two accidents; in the first, the metals were poured together; they took fire, which caused some to fly up to the ceiling and
fall back upon the floor; and in the second, the metal was spilled and
scattered very much over the cellar floor; it took place in clhanging the
kettles of water.
I received several lots of grains, and melted them down, by your
request and Mr. Booth's orders, which I understood from yourself,
Thomas, and Jamles Kane, that they came from the test furnace pulled
down by you.
I kept a correct account of all articles used by you, while you were
engaged at the mint, and furnished copies to the officers of the same.
Yours, respectfully,
ARCHIBALD PORTER.
Mr. R. S. McCTLLOH.




34
(7.)
PHILADELPHIA, April 27th, 1852.
DEAR SIR: Will you do me the favor to reply, in writing, to the following questions:
1. What assistance did you render me in my late experiments at the
mint, upon refining gold with zinc, and by whose orders did you act?
2. How did the process work, both in the granulating and in the
acid; if there was any difficulty, or any accidents, which occurred, to
your knowledge, what was it, or were they; and what was the quality,of the gold refined?
Yours, very truly,
R. S. AMcCUL.IOH.
Mr. JOHN MCCONN.
(S.)
PHILADELPHIA, April 28, 1852.
DEAR SIR: I assisted you in the refining room; in putting down the
metal in the lead vats with the vitriol; also in the sweetening or filtering of it; and assisted in taking the silver up with the nitric acid, in
the porcelain jars.  I assisted in preparing the furnace for granulating,
luting and fixing valves, by your request, and tapped the metal out for
granulating, when ready; because I was accustomed to working gas
apparatus, and understood the fixing of retorts and valves. I assisted
in the cellar to remove the vessels and granulated metal.  I acted by
orders of Mr. Monell, the foreman of the refining department, and
understood fiom him that the director had told him, that you were to
have all the assistance which was required. The process worked well
in the granulating, likewise in the acid; there was a difficulty in the
valves, which we got over by a little experience, and got thenm to
answer the purpose well. An accident occurred in the cellar, where
we had the vessels placed to receive the granulated metal; one vessel
was not large enough, and by taking it away to put another in its
place, the metal happened to spill on the [floor,] but afterwards we
got hogsheads to hold the metal. all at one time, without moving, and
had no trouble after so doing.  The metal was fine, and made good
toughened bars.             Yours, respectfully,
JOHN McCOiNiN.
Prof. R. S. McCULLOH.
P HLADELPHIA, A/pril 27, 1S52.
DEAR SIR: Will you oblige me by answering the following questions:
1. What had you to do with my late refining of gold with zinc, in
the mint; and by what authority did you aid me?
2. How did the process work, arid what was the character of the
metal?




35
3. If any accidents happened to your knowledge, what were they;
*and if there was any peculiarity in my mode of conducting the process,
what was it, and what were the effects?
Yours, very truly,
R. S. McCULLOH.
Mr. THos. CLARK.
(10.)
WEST PHILADELPHIA, April 28, 1852.
DEAR SIR: I received yours of yesterday asking me questions in regard to your late experiments at the mint, and without delay proceed
to answer.
1. I aided you in working the tnetal in. both the sulphuric and nitric
acid, and in watching at night. And I assisted my father-in-law, Mr.
Summers, in toughening the gold after it was refined. I did so by
order of the foreman of the refining room, Mr. Monell, who said he
was authorized, by the director of the mint, to render you such assistance as you needed.
2. The process worked satisfactorily, and the gold was good; it
toughened, and made ingots for coining, without any diffictlty whatever.
3. I heard that accidents had happened, but was not present, and
cannot, therefore, state the particulars. You had a peculiar granulating furnace, which made the granulations much better; and you
worked the metal with two kinds of nitric acid, one diluted and the
other strong, which made the metal toughen without difficulty.
Very truly, yours,
T. L. CLARK.
Prof. R. S. MCICULLOl.
(II.)
PHILADELPHIA, April 27, 1852.
MY DEAR SIR: Will you please to state what you had to do in connexion with my late experiments upon refining gold in the mint; what
you know of the quality of the metal so refined; what accident or accidents happened to your knowledge, if any; and what were the advantages of my mode of granulating, in comparison with that previously
and now employed?
Very truly, yours,
R. S. M1cCULLOH.
TOWTNSEND YEARSLEY, esq.
(12.)
PHILADELPHIA, M1ay 4, 1852.
DEAR SIR: In answer to your request that I would state, what I hlad
to do with your late experiments upon refining gold in the mint: on
the 5th of February, I assisted you at the granulating furnace in the




3v
melting room, and in the cellar beneath, until the first granulation was
made; then went into the refining room and took charge of the metal
for you, personating you in your absence. The quality of the metal
refinled by you appeared to be very good; experienced workmen, there,
stated in my presence that they had never seen better. An accident
happened in the cellar; in changing the kettles, the metal fell on the
floor of the cellar. The advantages of your mode of granulating are
great; the granulations were much finer, evener, and presented more
surface for the acid to act upon, than those which 1 saw made by the
present mode; there is no loss of metal by spilling it into the fire and
on the floor; and a much larger quantity of metal may.be worked
with much less labor.
Very truly, yours,
T. YEARSLEY.
R. S. MCCULLOH.
(13.)
PRINCETON, MAay 5, 1852.
DEAR SIR: Will you oblige me by answering the following inquiries
concerning my late proceedings in the United States mint:
1. Do you know how I was occupied during each of the months of
January and February last; if so, please state what you know of my
proceedings, and if you had any thing to do with them, state in what
capacity, and what it was.
2. Do you know any thing concerning certain gold grains, or dirt,
reported to have contained gold, gathered from a cupelling furnace,
torn down in the mint by my direction; if so, please state your knowledge; and if you, or others acting under you, did any thing in relation thereto, state what you, or they, so did.
3. Did you, or did you not, build o' construct for mne, during the
months of January and February last, in the United States mint at
Philadelphia, a peculiar furnace for granulating gold and zinc; and if
you did, please to state what you know of the invention of said furnace; and whether the same was or was not constructed in whole or in
part at the expense of the United States; and if you saw or know how
said furnace worked, state your knowledge of its work; also please
state, whether you had ever previously seen or heard of any furnace, or
arrangements, like those employed by me, and adapted to a like purpose; and if you know what has become of said furnace, please to
state what.
4. Did you, or did you not, witness any of the operations, performed
by me in the mint, and forming part of' the trial of a new method for
refining gold; did you or did you not see any of the gold when refined,
and did you or did you not form an opinion or conviction, or hear any
person or persons skilled in refining gold express his or their opinion
or conviction, in relation to said operations, or the merits of said
method, or the quality of said gold; and if your reply to each or either




37
of these inquiries be affirmative, please to state the facts in relation
thereto.
5. Did you witness, or do you know, any thing relative to any accident, or accidents, which may have befallen my operations; if so,
state the particulars thereof.
6. Are you acquainted with Martin Summers, and do you know
what is his reputation among the persons employed in the mint of the
United States and others, both with reference to his skill as a melter
and refiner of gold, and his personal integrity; if you do, state what
that reputation is.
Yours, very truly,
R. S. McCULLOH.
PASCAL YEARSLEY, esq., Philadelphia.
(14.)
PHILADELPHIA, May 14, 1852.
MY DEAR SIR: I have the honor to reply to your several questions:as follows:
I know that you were engaged, in the month of January, in the:superintendence of the pulling down of a reverborating furnace, and
building of a new one in the basement of the United States mint —.also in getting up machinery for a furnace, and in trying a small experiment. As master bricklayer, I was employed by the director of
the mint to tear down and build the aforesaid furnaces, and by himn
directed to take my orders from you. During the latter part of January and early in February, I also built by your request, and on your
account, in the melting room of the mint, a furnace for granulating
zinc and gold, which furnace was used by you in tile refining, in which
you were engaged during the rest of February.
I do know, that dirt containing grains of gold was taken from tile
furnace torn down in the basement, which dirt and grains were delivered by the men under my direction, and at your request, to Thomas
Lewellen, a workman of the mint, to be gathered into proper form.
I did build such a furnace, according to a drawing made by you in
my presence, and at your expense, wholly; 1 saw said furnace worked
by you upon several occasions, and the work done by it was pronounced by those present, skilled in the work of the mint, to be the
best granulation ever done in the mint; I never saw or heard of such
a furnace before; after you had done with it, I had it pulled down and
removed, as requested by you.
I did witness some of said operations, and did see a large quantity
of the gold refined by your process; I formed a very favorable opinion
of the quality of the gold fiom observation of it, and comparison with
other refined gold, which I had frequently seen in the mint; and I
heard remarks made by experienced workmen of the mint, and by the
director also, that your method of granulation was a beautiful process;,and I heard the gold refined by you and your new method, spoken of




38
in terms of the highest admiration by the workmen of the mint generally, and by those in the refining rooms especially. I witnessed the
results of an accident which occurred in the evening in one of your
granulating operations; the gold was spilled in the cellar, scattered in
grains for several feet around upon the floor, splashed upon the
side walls, and adhering closely to the clothes of perhaps a dozen
men, who were standing round when the accident occurred; some of
them had their pantaloons destroyed, and others were themselves
burned; water had also been poured over the floor. 1 aml acquainted
with Martin Summers, whom I have known for years; and I know
that his reputation, as a skilful workman in gold, is the very highest
among the persons employed in the mint; and that he is generally
reputed to be a man of the strictest integrity.
Very truly, your obedient servant,
PASCAL YEARSLEY.
Plrof. R. S. MacCULLOH.
(15.)
PRINCETON, July 1st, 1852.
MY DEAR SIR: Will you do mne the favor to reply to the following
additional inquiries:
Did you, or did you not, make, fromn the accounts of acid used by
me, in my refining operations at the mint, deductions both of nitric
and sulphuric acid; if you did, why were such deductions made?
Do you, or do you not, know why my refining operations were not
extended to an amount much greater than they were; and if you do,
what was the reason?
Very respectfully, your obedient servant,
R. S. McCULLOH.
Mr. JOHN I. MONELL, Philadelphia.
(16.)
PHILADELPHIA,.July 6th, 1852.
MY DEARL SIR: I did imake deductions of nitric and sulphuric acid;:
a large quantity of each, which had been delivered and charged to
you, was returned by you; and for that reason, deducted from your
account by me.
I know that your operations were stopped, that the public work of
the mint might be carried on; and the apparatus, was required for that
purpose, which you were using.
Very respectfully, yours,
JOHN I. MONELL.
Prof. R. S. IMCCJLLOH.




39
(17.)
WASHINGTON, May 1st, 1852.
DEAR SIR: In compliance with your oral request, to state in what
manner I assisted you, in your recent operations at the mint of the
United States, in Philadelphia, in testing the practicability of the
method of refining gold bullion, invented by you, and the opinion I
formed of it, compared with the old process, I have to make the following communication:
On the 11th of February, I was directed by the superintendent of
weights, measures, &c., Prof. A. D. Bache, to proceed to Philadelphia,
to make, at the ciustom-house there, certain experiments required in an
investigation I was engaged upon, under his direction, at the office in
this city. On the same day I received a letter (a copy of which is
submitted herewith) firom the Secretary of the Treasury, Hon. Thos.
Corwin, introducing me to the director of the mint, Dr. George N.
Eckert, and stating that, should my duties permit., and you desire my
services, I was at liberty to aid you in testing your process; and that
the director should, in that case, receive me as your assistant. On my
arrival, I was presented to the director, who said that every means for
aiding you should be placed at my disposal, and the proper persons
were notified accordingly.
You desired me, particularly, to keep a memorandum of the materials used, conjointly, with the persons assigned for the purpose by the
director; to make myself familiar with the details of the new process;
and to note anything important that might arise in the course of the
operations when you were, or were not, present in person. My duties
at the custom-house occupied me during the principal part of the day,
from the time I arrived in the city (Thursday morning, February 12th)
until the following Tuesday; but I was with you at the mint during
the afternoons and evenings. After Tuesday, until Friday night, I
was there nearly all the time, my presence being then required only a
couple of hours each morning, for my own duties. On Friday night
I returned to Washington.
Until the time of my arrival you had been engaged, I understood,
in tearing down an old test furnace, erecting new furnaces, and in
subjecting your method to preliminary trials. At that time, you were
also making analytical examinations of the products of each step of
your process, which of course consumed much time; but the question
of rapid working had not yet been entered upon.
These preliminary investigations were in such a state of forwardness
on Monday morning, the 16th, that you then melted about eight thousand (8,000) ounces of gold bullion with zinc, in proper proportion for
granulation. This was understood to be the first of a set of workings,
on a large scale, authorized by the Secretary of the Treasury in his
letter of instructions to the director. In the melting for this granulation, there was no volatilization of the alloy; the melted surface was




40
perfectly bright and unruffled, all the time it was exposed to the air,
previous to tapping the pot. There was a little delay in making one
of the granulations in consequence of the valve in the bottom of the
pot getting out of order, an unimportant accident; for, when the obstruction was removed, which did not occupy more than an hour, the
granulation took place with perfect success. The grains, I observed,
were remarkably uniform in their character, finer than those obtained
by the old process of pouring by the hand, and much better adapted
to the rapid action of acid. Besides giving this uniformity of character in the grains, your mode of granulating has the great advantage
over the old one used in the mint, that none of the alloy is, or can
possibly be, spilled into the furnace or upon the floor, but goes directly
from the retort into the reservoir of water. You have also prevented
another liability to waste, by taking the granulating water with the
grains directly to the refining room, and there using the same water
for diluting the sulphuric acid, which is required in the next step.
On Tuesday, the zinc was separated from the gold with dilute sulphuric acid, and on Wednesday, the gold was washed. This was a
longer time than was actually required for the separation, for part of
the time your attention was called to the completion of some previous
workings; and the workmen had received instructions from you, not to
do any thing without your presence and your express orders. On
Thursday the gold was transferred to the vessels for digestion with
nitric acid. The first acid employed was weak, and had been already
used on the gold of your previous operations, so that it was partially
saturated with silver. After this acid had become thoroughly saturated
it was removed, and strong acid employed to make the gold fine and
perfectly tough. Thursday and Friday were occupied, in part, with
this separation of the silver and any impurities from the aforesaid gold;
and you were also engaged in washing other gold in powder, drying
it, preparing it for alloying with copper, or "toughening," as it is
called, and running it into bars. This was completed on Friday
evening. On being subjected to the usual tests by Mr. Summers, who
performed your melting operations, and Mr. Porter, the foreman of
the melting department of the mint, they both pronounced the refined
gold, resulting from the above described operations, to be perfectly
tough, and very much superior to that obtained by the process then
employed in the mint. I found, on striking one bar against another,
that they were unusually soft, large dents having been thus made; and
in the pieces clipped off the corners of several of the bars, there was
not the slightest evidence of crystalline fracture.
I obtained from Messrs. Porter and Monell the cost of the materials
used by you, viz., sulphuric acid, nitric acid, and zinc, and an estimate of the cost of the labor, fuel, crucibles, fluxes, &c., presented
herewith; which shows a very decided superiority of your process over
the old method in point of economy. But there is every reason to
believe that the rate of expense thus shown, could be considerably reduced by suitable apparatus and enlarged operations, especially when




41
each workman should become familiar with the part to be performed
by him. This reduction will also hold good with respect to the time
required. Much time is always necessarily consumed in new methods
of working of- whatever kind, without direct result in the object to be
attained, except in perfecting the different parts, and training the
operators to worlk with care and certainty.
When I was with you in the mint, during the last year you held
the office of melter and refiner, (in 1848-'49,) assisting you in some
extra-official duties for the office of weights and measures, not completed before you accepted the mint position; you were kind enongh
to give me the opportunity of studying all the parts of the old process,
both before and after you had introduced the modifications and enlargement of the machinery. The apparatus now in use there, is the
same you then had constructed, the only changes being in extent, and
such as an increased quantity of bullion to be refined required. In
comparing this old process with your zinc process, as conducted on an
enlarged working scale, the facts above stated, and my impressions received during the daily progress of your operations that 1 witnessed, I
am led to conclude, that your method of refining is susceptible of being worked more advantageously than the old method, by silver quartation, in the following particulars:
1st. In the granulation, zinc being substituted for silver, there being
no liability to spill the alloy, and the time required being less than
hand pouring:
2d. In the substitution of sulphuric acid for nitric acid, in separating
the zinc from the gold:
3d. In the gold being perfectly tough, and fine enough to make the
smallest gold coin from the first ingots after the bar meltings, which
produces a saving in time and wastage; all the small gold coins now
made, as I am informed by the workmen, can be made only from ingot clippings or remelted metal, thus consuming time and encountering wastage:
4th. In economy of time resulting from improvement in the mode
of granulation, and fromn dispensing with the precipitation, washing,
reducing, and melting the large quantities of silver, required in quartation, and the smaller quantity of sweep to be handled:
5th. In saving the wastage on the large quantities of silver used in
the old method, and in saving the interest on this silver, as part of the
material of the operation:
The machinery required to carry your process into effect would not,
in my opinion, be more expensive than that now used at the mint for
refining; but, on the contrary, I think it would involve less expense, as
there are fewer operations required in the zinc method. The workmen
having had no difficulty in carrying out your process under your direction, there is not the least doubt that they could be trained in a short
time to use it, in the regular operations, as familiarly as the one to which
they are now accustomed.
It gives me pleasure to be able to state, in conclusion, that every part




42
of the experiments which I witnessed, was in my opinion entirely suc —
cessful; and unless the report of the assayers in respect to fineness.
should condenn it, I do not hesitate to express my conviction that it
would be to the advantage of the Government, and. the commercial
community, if it were adopted, and introduced into the mint of the
United States, and its several branches.
Very respectfully and truly yours,
WOODS BAKER.
Prof. RICHARD S. MCCULLOH,
College of N. Jersey, Princeton, LN. J.
I18.)
TREASURY DEPARTMENT,
February 11th, 1852.
DEAR SIR: The bearer, Woods Baker, esq., goes to Philadelphia
under instructions of the superintendent of weights and measures, to
perform certain experiments for that office, at the custom-house. Should
his duties permit, and Professor IMcCulloh desire his services, he is at
liberty to aid him in testing his process for refining gold; you will please
receive him accordingly.
Very respectfully,
THOS. CORWIN.
GEO. N. ECKERT, esq.,
Director, U. S. mint, Philadelphia.
(19.)
Memorandum of expenses attendant upon a trial of:l1c Culloh's process for refining gold bullion, at the U. S. mint, February 22d,
1852.
Quantity used 14,000 ounces, or $250,000.
7 granulations of zinc of 343 lbs. each, equal to 2,400 lbs.
a 4 cents                                -. $96 00
6,100 lbs. sulphuric acid a 2 cents per lb.  -    -   122 00
1,773 lbs. nitric acid a 7:- cents per lb.  -  -  -   126 32
Fuel    -,                                            5 00
Labor   -      -      -      -      -      -      -    50 00
Crucibles, fluxes, &c.   -.                -      -      5 00
$404 32
Charge to depositors for refining the same quantity (14,000 oz.) at 5
cents per oz. $700.00, leaving a balance in favor of the zinc method
of $295.68, as a result of this single experiment, which should not be
considered ultimate. A considerable reduction of expense and time,
which is of much greater consideration, could be made by perfection
of machinery, worked with trained operators, and on large quantities of
bullion.




43
(20.)
UNITED STATES HOTEL,
Philadelphia, February 19, 1852.
SIR: Experiments were made yesterday in the melting department
of the mint, the object of which must, I conceive, have been to test
the applicability, to the silver quartation process, of features embraced
in my improved method of granulating gold bullion to prepare it for
parting, whether the same be alloyed with zinc or silver. And preparations are, I understand, now going on to try similar experiments
upon a larger scale.
As it was orally agreed between yourself and me, according to my
recollection, that any experiments touching the application of modes of
working, used by me for my zinc process, to the old or silver process,
should be tried concurrently by the melter and refiner, and myself, I
respectfully submit, for your consideration, whether the aforesaid experiments and preparations are not in disregard of said agreement. But
whether they be so or not, as they, I believe, infringe upon my rights,
professional and legal, I hereby respectfully remonstrate against their
further prosecution.
Very respectfully, your obedient servant,
RICH. S. McCULLOH.
Dr. GEO. N. ECKERT,
Director U. S.  Mint, Philadelphia.
(21.)
MINT UJ. S., February 20, 1] 852.
SIR: 1 received your letter of yesterday. You complain of some
trials made in the mint, in granulating gold with silver, by pouring the
metal through a crucible perforated with holes, as an infraction of your
legal. and professional rights, and not in accordance with the understanding between us.
These trials were made at my instance, with a view to an improvement, having no connexion whatever with your patent, so far as I
understand it. This reminds me of the fact, that you have omitted to
furnish me with a copy of the specifications of your patent, which I
deem it necessary for me to have; and as I am desirous of seeing
your process fairly and fully tested, and leave you, so far as lies in my
power, no ground of complaint whatever, I will suspend all action in
reference to changes contemplated for the present.
Very respectfully, yours,
G. N. ECKERT, Director.
Prof. R. S. MCCULLOH.
(22.)
OFFICE OF MELTER AND REFINER, U. S.  MINT,
February 6, 1851.
DEAR SIR: Having completed my experiments on the processes for
refining, so far as to form an opinion of their relative merits, I herewith submit that opinion to you.




44
By the process at present pursued at the mint a sufficient amount of
gold may be refined, in all probability, to meet the deposites-say as
much as eight or nine millions per month; but there are objections to
the process which it would be very desirable to obviate, if practicable.
The process is attended with the evolution of a very large amount of
noxious and disagreeable vapor, the avoidance of which I believe to be
impracticable, except to a limited extent; and this vapor is not only
inconvenient and injurious to the workmen, but is likewise highly objectionable to those residents of the city who are in the vicinity of the
mint. The process is one of the most expensive, requiring more
manual force to melt the mixed gold and silver, and to carry it through
the refining process; more fuel to melt three times as much metal as
there is gold in the mixture; and a large amount of the most costly of
all common acids, together with a large consumption of zinc, to recover the silver employed in refining. Add to these the large amount
of silver, upwards of $200,000 removed from circulation, and retained
only for the purpose of refining gold.  In most other points, the present process is an excellent one.
Mr. McCulloh's process consists, in the substitution ~of zinc for silver
in the present operation, whereby a low temperature is required for
melting the gold and zinc. diminishing greatly time, fuel, and labor.
In the next part of the process, cold and dilute sulphuric acid is used
to remove the zinc, and obtain the gold and its silver in a pulverulent
state, so that the nitric acid will then remove the silver readily from
the gold. So far, the process is everything that could be desired, requiring but one precaution, that is, the due regulation of the heat when
melting gold and zinc together, for too high a temperature is apt to
volatilize gold with the zinc. This can, however, be entirely guarded
against. The only difficulty hitherto experienced, in carrying out this
process, lay in the brittle character of the gold; and the difficulty of ohtaining it in a malleable state, in any of the experiments hitherto made,
except the last. I have not been able to obtain it in a tough condition
upon a test, whether with or without lead or copper, nor in a black
lead crucible; but it can be toughened in a sand crucible, or on a
hearth of a reverboratory, whether a bone ash test or not, by the use
of ordinary means.
Now, as a reverboratory can be constructed, on which several hundred
thousand dollars of gold can be daily toughened, I think that the process of Mr. McCulloh is, in all respects considered, the best that could
be adopted at the U. S. Mint. It is next attended with far less expense
than the present method, and with no noxious fumes, and a larger
amount of gold may be operated upon in the same space, and in the
same time.
The process of myself and Mr. C. Morfit consists in dissolving gold
by means of salt, nitre, and oil of vitriol, or by muriatic acid and nitre,
in stoneware or glass vessels, by steam heat, or a sand bath, or in wellsecured wooden vessels by steam blown into the liquid.  Immediately
after solution is effected, copperas is added to the solution to precipitate




45
the gold.  The gold and chloride of silver being filtered and washed,
the chloride of silver is extracted from the gold by a solution of salt or
an alkaline hyposulphite; or the chloride is reduced by zinc, washed,.
and the reduced silver extracted by nitric acid.  This process recommends itself by the low c6st of materials, in which respect it excels all
others; by a complete extraction of silver from the gold, if necessary;
by the convenience of using different kinds of vessels, according to the
opportunities of procuring them; and by the use of less acid than any
other process. Since, however, its use would not be a gain in the time
required for refining, over the present process, and its introduction
would require a total change of apparatus and arrangements in order
to carry it out most successfully, attended with loss of time in making
such change, I do not recommend its adoption in the Philadelphia
mint. But as wooden vessels can be used with this process, and as it
requires a very small amount of acid, it might be advantageously
adopted in California, or where the use of much acid, or of stone or
glass vessels, is objectionable on the score of expense.  In such places
under the above considerations, it is the best of the three processes.
In conclusion, therefore, I would respectfully recommend the adoption of Mr. McCulloh's process at the U. S. mint, since it can be introduced without interfering with the operations of the mint, and presents the advantages above specified.
Very respectfully, your obedient servant,
(Signed)                   JAMES C. BOOTH,
HI. and R. U. S. Mint.
R. M  PATTERSON, esq.,
Director U. S. Mint, Philadelphia.
(23.)
PHILADELPHIA, February 27, 1852.
Prof. R. S. McCULLOH,
To United States' Mint, separating department.
To 7,675 lbs. sulphuric acid, at 2 cts    -    -    -    - $153 50
2,065 lbs. nitric acid, at 7 cts     -       -    -   147 13
6 men, 8 days each, 48 days; at $1 80    -        -    86 40
2 tons coal for steam, at $4       -                    8 00
2 bushels of salt, at 34 cts            -    -    -        68
(3. 1. MONELL.)                                       $395 71
(24.)
PHILADELPHIA, February 17, 1852.
Prof. R. S. MCCULLOH,
To United States' mint, melting department.
February 17, to 10 bus. charcoal, at 15 cts    -    -   -    $1 50
to 4 of a cord pine wood, at $6     -    -     1 50
to  4    do   hickory do., at $6 50      -     1 62




46
February 17, to  2 black lead pots, No. 50, at $2    -         -       4 00
cc    1"  to  1 do.  do. do., No. 35           -    -    -         1 40
cc    1"  to  1 man, five days, at $1. 70   -    -          -      8 50
19, to  1 black lead pot, No. 50, and lid   -       -       2 71'"  to 10 lbs. of borax, at 65 cts      -    -             650
"'   "  to 10 lbs. of nitre, at 8 cts          -      -     -         80
C"     20, to  1 black lead pot, No. 10         -    -    -           40
cc     c<- to  I  do. do.do.,  No. 50           -    -      -      2 00
"C'    24, to  1  do. do. do., No. 50           -    -      -      2 00
c;    c'  to 10 bushels charcoal, at 15 cts          -             1 50
25, to  { cord of pine woot, at $6   -       -     -       1 50
26, to  1 man, one day   -    -         -     -     -       1 70
28, to  3 sand pots, at 3 cts    -    -    -    -             09
"  to  4 bricks, at 4 cts        -    -      -    -          16
"  to  5 lbs. borax, at 65 cts  -    -       -    -       3 25
"      "  to  5 lbs. nitre, at 8 cts      -     -    -    -           40
~"     "  to 10 bushels charcoal, at 15 cts  -    -                1 50
March       1, to  8 lbs. borax, at 65 cts         -     -     -       5 20
2, to 10 bushels charcoal, at 15 cts -       -     -       1 50
cc       3, to  8 lbs. borax, at 65       -    -      -    -        5 20
cc       3, to 10 bushels charcoal, at 15 cts -    -        -       1 50
cc       3, to  I of a cord pine wood, at $6          -    -        1 50
4, to  3 pair gloves, at 75 cts  -    -      -    -       2 25
4, to  2 lbs. lead, at 4 cts                                 Os-    -  -  -  08
4, to  I bus. bone ashes, at $3        -     -     -       1 50
5, to  1 wrought-iron pot, 107k lbs -               1 07
5, to  1 black lead stirrer      -        -        -         30
10 to 6- lbs. mercury, at 90 cts       -    -    -         5 85
10, to 16 bush. Cumberland coal, at 22 cts          -       3 52
11, to 10 bush. charcoal, at 15 cts   -    -    -           1 50
"  11, to  1 black lead pot, No. 14     -     -     -         5
11, to  1 sand pot   -    -    -    -    -    -                 3
11, to  1 man, one day   -                                  1 70
11, to 3,051 lbs. zinc, at 4 cts  -                      122 04
$19S 33
(Archibald Porter.)
(25.)
Operation No. 1, in account for gold.
DR.
Standard weight.
To part of deposite No. 633, weighing 346.12 ounces, 8855 Eneness,   340.543 ozs.
CONTRA CR.
By lump from crucible      do.   42.88 ozs. at 879   do.      41.880  "
By bar No. 1               do.    9.85'"   993   do.        10.868  "
By bar No. 2               do.  128.90   5   991   do.       141.933 "
By bar No. 3               do.  1'28.81'"   991.4 do.      141.891  "
By grains                  do.    3 53                         3.530'
By balance, wastage, and in sweeps                             0.441  "
340.543 "




47
This operation was attended with accidental spilling of metal upon
the  floor of the  melting  room.  A larger number of crucibles, than,ordinarily, was employed for the meltings and fluxings, each of which
would imbibe particles into  its pores; when these facts are taken into,consideration, the apparent wastage is not unusually great. The 3.53
ounces of grains are estimated as of standard, because when they were
to have been melted for assay, the crucible broke, and they were spilled into the fire.
Operatio,   No. 2, in account for g'old.
DR.
-Ounces. |Fineness. Standard ozs.
Feb.   5  To deposite 1051................   1,219.31       892.5       1,209.149
Feb.   5  To deposite 1052............          733.41      897.0         730.965
Feb.    6  To deposite 1048............       1,212.98      884.0       1,191.416
Feb.   6  To deposite 1050.................   750.60        883.5         736.839
Feb.   11  To deposite 1097................   1,197.38      882.0       1,173.432
Feb.   11  To deposite 1098................    798.10       880.5         780.808
CONTRA-CR.               5,911.78...........      5,822.609
April   1  By bars Nos. 1, 2, 3, 4, 5, 8, 10, 16, 18  2,768.41  989.2    3,042.790
April   1  By bars Nos. 7, 11, 12, 13, 14, 15, 17  2,180.61  990.2       2,399.156
April   1  By bar No. 6....................    181.06       988.2         198.804
April   1  By grains marked G. Z., No. 1....    103.41      959.8         110.281
April   1  By grains marked G. Z., No. 4          73.62      464.6          38.004
Feb.  21  By assays cut from bars Nos. 1 to 18     t.77      989.7           1.946
March  1  By assays cut from G. Z., No. 1          0.09      959.8           0.096
March  3  By assays cut from G. Z., No. 4....      0.14      464.6           0.072
March 12  By half an assay slip 0.07 oz., from
G. Z., No. 5............................ 19.1          0.028
March 12  By half an assay slip 0.06 oz., from
G. Z., No. 6................                 706.4           0.027
March 13  By half of 1.63 ounce assay slips 
reservel from fine gold..........    985.5            0.892
March 13  By half of 0.98 ounce assay slips
reserved from G. Z., No. 1 to 6..              743.0           0.405
April   1  By half of 6.95 oz. of gold in sweeps..1,000.0                  3.861
April   1  By half of 12.94 ounces, in grains,
G. Z., No 5, from furnaces..............l    719.1            5.170
April    1 By half of 12.28 ounces amalgam,
G. Z., Ne 6, from sweeps......        706.4           4.819
Apri   1  By half of 1.62 ounces dirty grains......    671.0               0.604
April   1  By half of 0.90 ounce gold assay
slips...........................    985.5             0.493
April   1  By balance or apparent wastage...         15.161
5,822.609




48
(27.)
Operation  No. 3, in accountfor gold.
iOunces. Fine-  Standard
Dr.                       I          ness.  ounces.
Feb.    16 To deposite 1100........................            67.18  884       753.541,' 16            "    1096............................ 1,193.47 883.5  1,171.590
"      16       "    1101..........................i   780.79 911              790.333
44.  16         "    1099...................           1,205.3   888    1,189.298
161    "4   1053.......................w...    1,216.97  880    1,189.926
"'     16        "    1049.......................             736.92 884        723.819
i      ]16 " 1233..                                          630.35  884        619.144
i':    16       "    1113..                                  907.51 881.5    888.856
16'   1225.................i 333.32 878.5    325.357
" 16'    1098............................  102.17 880.5             99.956
Contra.  Cr.                   i7,874 05 _       7,751.820
April    I Bybars No. 1......................... 3,217.50 983.3  3,515.298... 1         ". No. 2.......................... 3,102.56 981.6  3,383.860
"6 11  I         No. 3.....................i 563.79  978.1    612.714
4"      1   grains G. Z. No. 2.............          191.41 959.3    204.021
I!     t   G. Z. No. 3..............!  14.84 649.1        10.703
1    fine gold in powder...........         0.19  982.5       0.207
1    zinc gold 1.10 oz. and 0.1 assay, March 11.. 1.20  654.01           0.872
Feb.    25    assay slips from bars Nos. 1 to 3..........    1.49 981.6            1.625
M arch    4a'    G. Z. No. 2..       0.13  959.3       0.138
is 4            "       "    G. Z. No. 3........... 0.11 649.1  0.079
"      12    half of the assay slips from G. Z. Nos. 5 and 61......       0.055
"      13       "    "        "   reserved from fine goldl
and grains..................................       1.297
April     1    half of  6.95 ounces of gold in sweeps.................             3.861
"'  12.94 ounces of grains, G. Z. No. 5,1                  
from furnaces................................          5.170
i;   i   "   12.28 ounces of grains, G. Z. No. 6,i
amalgam, &c.,.....................                     4.819
"'     ~     "      1.62 ounces of dirty grains...........i       0.604:      li ~1         0.90 fine gold assay slips................0...            0.493'    balance or apparent wastage...............          6.004,i                7,751.820
REMARaK.-In the above account this third operation is credited with one-half only of
the gold contained in the sweeps; of the amalgam, G. Z. No. 6, from  the same; and of
the grains obtained by cleaning the furnaces, G. Z. No. 5, &c., although it might justly
have been credited with a larger proportion than operation No. 2, which was smaller.




(28.)-Abstract of accounts, United States Mint.
Report of 1st Iluditor, No. 105,120-4th quarter of the year, 1850.
GOLD DEPOSITED.          SILVER PARTED.                                            DEDUCTON'S,
For parting.           Silver alloy. -    Copper alloy.
Nov. 14....$2,255,202.35  Nov. 14.....$16,045.47  Nov. 14....$5,613.13  Nov. 14....$2,844.37    $447.72        Silver alloy 5 p. c. on
Dec. 31.... 6,822,548.18  Dec. 31..... 39,124.88  Dec. 31....13,498.26  Dec. 31....17,079.87          |         and from Nov. 14.
Value....$9,077,750.53  Value.....55,170.35               $19,111.39              $19,924.24  $447.72        Total......$39,483.35
Report of Ist Aucditor, WNo. 105,660. —1st quarter, 1851.
GOLD DEPOSITED.           SILVER PARTED.                                          DEDUCTIONS.
i     For parting.      5 per cent. silver alloy.  Copper alloy.    Total.
588,234.062 oz. stand'di  51,067.05 oz., standard    $20,318.81              $25,679.97           $405.50          $46,404.28
$10,943,889.51  value    1 $59,423.46 value
Report of 1st l2uditor,.No. 106,256.-2d quarter, 1851.
COLD DEPOSITED.      i    SILVER PARTED.                                           DEDUCTIONS.
For parting.     2 per cent. silver alloy.  Copper alloy.      Total.
524,255.606 oz., stand'(i:  58,067.97 standard oz.     $23,255.71             $11,766.71            $734.65         $35,757.07
$9,753,592.86 value        $67,570.00 value




ABSTl'RACT- Continued.
Report of 1st Aluditor,.No. 106,694.-3d quarter, 1851.
GOLD DEPOSITED.          SILTER PARTED.                                          DEDUCTIONS.
For parting.      2 per cent. silver alloy.  Copper alloy.     Total.
605,895.772 stand. oz.  68,007.08 standard oz.       $27,304.17             $13,819.28          $861.70          $41,985.15
$11,272,479.49 value      $79,135.51 value
Report of 1st Aluditor,.No. 107, 165.-4th quarter, 1851.
GOLD DEPOSITED.          SILVER PARTED.                                         DEDUCTIONS.
0
For parting.      2 per cent. silver alloy.  Copper alloy.     Total.
850,590.247 stand. oz.    97,399.74 stand'd oz.      $39,530.63             $20,031.92         $1,244.87         $60,807.47
$15,824,934.82 value       $113,337.88 value.




51
(29.)
Deposite.     Fineness.      Deposite.      Fineness.
No.          1000ths.         No.          1000lths.
633           8851           1097           882
1048           884            1098           8801
1049           884            1099           888
1050           883-           1100           884
1051           892,           1101           911
1052           897            1113           881i1053           880            122O           8781096           8831           1233           884
I certify that the fineness set opposite the above numbers respectively
agrees with the fineness stated in the assayer's reports of corresponding
assay numbers.
GEO. W. EDELMAN,
Treasurer's office clerk.
U. S. MINT, April 1, 1852.
(30.)
(Duplicate.)
The following is the result of the special assays of eight deposites,
made as requested:
No.                            Fineness.
1049       -        -    -      884.4
1053                     -      880.
1096       -      -      -      883.2
1097       -        -    -      881.4
1098       -      -      -       80.8
1099       -             - -    S88.2
1100       -             -      884.3
1101       -      -      -      911.2
J. R. ECKFELDT, Assayer.
February 14, 1852.
(31.)
(Duplicate.)
Special assays of four deposites, or parts of deposites, as requested:
No.                            Fineness.
1098       -      -      -      880.8
1113       -      -      -      882.
1225       -      -      -      878.3
1233       -      -      -      884.4
J. R. ECKFELDT, Assayer.
PHILADELPHIA, Beb. 20, 1852.




(32.)
Assays of seventeen lots of Mr. McCulloh's fine gold, of which slips
were cut off February 21, 1852, numbered as follows:
No.             Fineness.            No.             Fineness.
1              989.2               11               990.2
2              989.2               12               990.3
3              989.3               13               990.3
4              989.2                14              990.2
989.3               15               990.3
6              988.2               16               989.
7              990.1               17               989.9
S              989.2               18               989.
10              989.
Assays of three lots of same, of which slips were cut off February
25, 1852, numbered as follows:
No.                                Fineness.
1        -        -        -       983.3
2? -     -        -       981.6:.)      -                         978.1
J. R. ECKFELDT, Assayer.
(33.)
MARCH 27, 1852.
The following are the results of the assays of Mr. McCulloh's grains:
Fineness.
1st lot of grains, (March 1,)         -        -        959.8
2d   "       C    No.1    -            -                959.3
2    -        -        -       (49.1
3    -        -        -       464.6
4    -        -        -       866.8
5    -       -        -        719.1
i    -        -        -       706.4
The following are the results of assays of Mr. McCulloh's sweeps,
from  nine reductions; four made by Mr. Hare, and five by Mr. Summers.                                       /
Of those mnade by Mr. Hare, the
1st gave 199.5 mi!ligrammes gold, 111. milligrammes silver, in five ounces of sweep.
2d  "  191.7      do.    do. 106.3      do.      do.       do.       do.
3d     203.       do.    do. 118.5      do.      do.       do.       do.
4th "  199.      1do.    do. 126.        do.     do.       do.        do.
Of those made by Mr. Summers, the
1st gave 237. milligrammes gold, 135.5 milligrammes silver, in five ounces of sweep.
2d  "  229.       do.    do. 135.       do.      do.       do.       do.
3d  "  126.5      do.    do.  88.5      do.      do.       do.        10o.
4th  "  223.      do.    do. 153.       do.      do.       do.       do..5th  "  209.     do.    do. 132.5       do.     do.       do.        do.
J. R. ECKFELDT, Assayer.




.3
The average of the assays froln Mr. Hare's reductions of Mr. McCulloh's sweeps gives 198.3 milligrammes gold to five ounces of sweep;
at which rate 330 lbs. avoirdupois sweeps will contain 6.14 ounces troy
of gold.
The average of the assays from Mr. Summer's reductions of same
gives 204.9 milligrammes gold in five ounces; according to this result,
330 lbs. avoir. of sweep will contain 6.34 ounces troy of gold.
The average of the first, second, fourth, and fifth assays from  Mr.
Summers' reductions gives 224.5 milligrammes gold to five ounces; according to this, 330 lbs. avoir. of sweep will contain 6.95 troy ounces
of gold.
(34.)
JMemorandum  of assay slips cut from gold 2reined with zinc.
Ounces.  Assay.
Feb. 21  From bars Nos. 1 to 18 of lot No. 2...........   1.77
25   "     " " 1 to 3    "  No. 3..................   1.49
Mar. 1   "    grains G. Z. No. 1 of lot No. 2...................   0.09    959.8
4   "      "      "  No. 2  "   No. 3...................   0.13    959.3
4          "          No. 3  "   No. 3...................    0.11    649.1
4   "      "      "  No. 4  "   No. 2...................   0.14    464.6
8   "i   toughened or alloyed gold bars................      0.19    900.2
10   "    ingots for coining..............0............      0.30    900.4
11   "    zinc gold in a tube belonging to lot No. 3..........j  0.10    654.
12   "    grains G. Z. No 5 of lots Nos. 2 and 3.........     0.07    719.1
12  N"      "      "  NIo.6    "4 4;6: D~~  0.06    706.4
13  Six assay slips reserved by Dr. Eckert, from —
grains G. Z. No. 1, 959.8 fineness] 
(C"    "   No. 2, 959.3    "   I
" - "   No. 3, 649.1    "   I..No. 4, 464.6    " 
IC[........    0 64    743....  No. 5, 719.1    "0.64                                  743... "   No. 6, 706.4    "
Mean   743.         J
Ten assay slips reserved by Dr. Eckert, fromI bar No. 6, 988.2 lot No. 2; 6 bar No. 1, 983.3'
2   "   7, 990.1   "        7"      "  983.3
3   "  10, 989      "       8"  No, 2, 981.6 1
4   "  15, 990.3   "       9"'  981.6....   1.11    985.5
5   "  17, 9899   "       10;  No. 3, 978.1 1
Mean 989.5                  Mean 981.6J
From G. Z. Nos. 1 to 6, reserved by R. S. McC..........   0.34    743.
"   five bars of lot No. 2,   "     "    "    989.5     0.5       985.5
i  9No. 3,                  981.6              985.5




54
(35.) — Gold alloyed and made into ingots.
Ounces.  Fineness. Standard.
March 8  Dr. To bar No. 1, lot No. 2.........   305.17         989.2    335.427
To bar No. 18, lot No. 2...........    309.61      989.      340.249
To bar No.  1, lot No. 3...........   333 71      983.3    364 597
To bar No. 2, lot No. 3...........    312.20      981.6    340.506
To bar No. 3, lot No. 3............   281.64      978.1    306.080
16869859
March 8  Cr. By assay slips fronl bars.............   0.19      900.2         0.19
" 10       By assay slips from ingots..........      0.30      900.4        0 30
"  12      By 24 ingots......................  1468.32       900.4    1468.97
April 1       By ingots and tops.................   209.95      900.4      210.04
1      By grains.........................       7.61     (?      )    7.61
1687.11
REMARK.-The apparent gain of this account may be explained,
by the facts, that the grains are assumed as of standard fineness, though
they were probably less, and that some particles of gold, previously in
the furnace, may have been gathered with this metal. But in the
absence of an assay of the grains, there is no proof that the excess is
other than apparent.
(36.)-Memnorandum  of weigrhings of fine gold.
Lot No. 2.      Ounces.                   Lot  o.         OuncesLot No. 
-  I   I  i  __l c~ —~ —---— I-  O unce.
March  8  Bar No. 1.......   305.17   April  1  Bar No. 7......   288.53
March  8  Bar No. 18......   309.61   April  1  Bar No. 11.......   325.23
April   1  Bar No. 2......   297.33   April  1  Bar No. 12.......   327.91
April   1  BarNo. 3..            338.84   April       Bar No. 13.......   321.09
April   1  Bar No. 4....8. 337.23   April  1  Bar No. 14.......   311.44
April   1  Bar No. 5......   298.36   April  1  Bar No. 15........  329.36
April   1  Bar No. 8.            308.66   April  1  Bar No. 17.......    277.05
April   1  Bar No. 10.......   260.36
April   1  Bar No. 16.......   312.85                                     2,180 61
2,768 41
Lot No. 3.                               Lot No. 3.
March  8  Bars No. 1.......   333.71   March 8  Bars No. 2.......    312.20
April   1  Bars No. 1...... 1,282.16   April  1  Bars No. 2....... 1,203.44
April   1  Bars No. 1......1,601.63   April  1  Bars No. 2....... 1,586.92
3,217.50                                 3,102.56
March  8  Bars No. 3.           281.64
April   I  Bars No. 3......     282.15
563.79




(37.)
MINT OF THE UNITED STATES,
Philadelphia, 2d April, 1852.
DEAR SIR: Mr. Eckfeldt reports the fineness of the gold in powder
at 654 m. This and the fine gold are in my possession, and will be
given to you as you requested.
Very respectfully, &c.
GEO. N. ECKERT, Director.
Prof. R. S. McCULLOH.
(38.)
MINT OF THE UNITED STATES,
Philadelphia, 13th April, 1852.
DEAR SIR: Among the parcels of gold returned by you, the pro-.
ceeds of experiment No. 3, was one of " grains and dirt," weighing
oz. 1.79. With a view to avoid a mere estimate, I directed this
parcel to be melted. The weight returned was oz. 1.62; and on
assay the button is reported 671 mn.
Very respectfully, yours,
G. N. ECKERT, Director.
Prof. R. S. MCCULLOH, Princeton, N. J.
(393.)
PRINCETON, Priday, April 2'., 1852.
SIR: As no other probable reason for the discrepancy Between the
results from fluxing the samples of sweeps, obtained by Mr. Summers,
and those obtained by Mr. Hare, each having used like quantities of
the same materials, can be assigned, than that it is ascribable to the
different degrees of heat produced by the two flrnaces, used respectively by them; and as said sweeps, composed chiefly of bone ashes,
plumbago, fire clay, &c., are more than usually refractory, so refractory, indeed, that Mr. Summers failed to melt, except in part, one of
the samples used by him, I respectfully request that you will cause to
be melted and assayed two or more additional samples of said sweeps,
using for the purpose the following mixture, which is more fusible than
that heretofore generally employed in the mint: sweeps, 3 oz.; soda
ash, 3 oz.; potash, 3 oz.; borax, fused, 6 oz.; litharge, 6 oz.; salt, I oz.
The borax should be such as that used by Mr. Booth in the melting
department, fused and not in crystals, which contain about 47 per
cent. of water. Mr. Summers will probably nmake similar fluxings,
for verification, by my request.
If the sweeps, or dirt, from the large cupelling furnace, which was
torn down, have been assayed, I should be pleased to have the results
at your earliest convenience. If otherwise, you will oblige me by
directing that they be assayed.
Very respectfully, your obedient servant,
R. S. McCULLOH.
Dr. G. N. ECKERT, Director of the mint.




56
P. S. Permit me to invite your attention to certain remarks, which
may apply to the subject of this communication, to be found in the
treatise on assaying of M. Chaudet, pages 263, 264, a book which is
in the assay office of the mint.
(40.)
MINT OF THE UNIT'IED STATES,
Philadelphia, AMay 1, 1852.
SIR: My absence in Reading has prevented a reply to your note of
the 23d instant.
I regret to say that the sweeps which you request re-assayed have
been mixed with the other sweeps of the mint, so that your request
cannot be complied with.
There can be no objection, however, to taking the result of Mr.
Summers' smelting (excluding the one pronounced defective) as that
to be reported. The ounces thus reported are 6.95.
Very respectfully,
GEO. N. ECKERT, Director.
Prof. R. S. MCCUTLLOH Princeton.