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Ath. Of the amount of bullion received within the period embraced by table A, and exhibited in the first column, about one-tenth part consisted of Plata Pina. This term is applied to silver collected by the aid of mercury, and brought to the Mint without having been melted. The average value of this form of bullion, when reduced to a condition suitable for assaying, may be stated at $1 25 per ounce troy, being about 8 per cent above the standard value of our silver coins. It is to be noted, however, that Plata Pina is subjected to melting before it is assayed, and in this process is diminished; on an average, about 3 per cent. in weight, by the dissipation of some remains of mercury and of humidity absorbed by the porous quality of this form of bullion, as also the separation of other extraneous matters occasionally found therein; so that, in this condition of its ordinary delivery at the Mint, its value may be estimated at about 55 per cent. above its weight in silver coins. Bullion of other descriptions, on an average of the whole amount embraced in the table, is found to be worth about $i 21 cents per ounce, being about 5 per cent. above the value of standard silver. It is proper to state, that all silver, not in the form of coin, is in this arrangement denominated bullion, which thụs includes a proportion of plate. The great inass of it, however, consists of silver which has been melted only, but not wrought in any manner.

5th. Table A exhibits the proportions of silver bullion and coin received at the Mint, and also the amount of the several denominations of silver coins issued annuallý, from 1815 to 1830 inclusive. No separation is made of old and defaced from new and perfect coins. They are all received by weight as bullion. In the column of various coins, a large amount of irregular coins of Spanish America is embraced, called hammered and cast dollars, uden all the European coins, of which, except the five franc pieces, the amount is inconsiderable, and of these less than $200,000 are to be found separately deposited, within the period assumed. The column denominated Mexican dollars embraces also that of Central America; Peru; and Chili, which are generally deposited with the Mexican, but constitute an inconsiderable proportion of the amount under this head.

6th. The average loss by wastage on silver coinage may be stated at the fourth of one per cent. on the amount coined. The last four years give a small fraction less. This is borne by the United States; the depositer teceiving in coins; agreeably to law, all the fine metal he brings, and without charge if the bullion be of standard quality. If it be above standard, the depositer is charged for the requisite alloy, and, if below standard, he is charged with the expense of the materials required for refining.

7th. The wastage is not influenced by the character of the bullion as te fineness, unless it be such as to require refining. In this operation there inust be some loss, and all the processes by which other bullion is exposed to loss are subsequently to be passed through. The waste on refining will be in some proportion to the degree of baseness; but the ratio has not been determined. The wastage is ascertained only at the end of the year. Very few deposits of coins require to be refined. They are among the deposits, therefore, liable to the least wastage, and there is no appreciable difference, in this respect, between new and old coins.

8th. The expense of the coinage of silver is necessarily combined with that of gold. On an average, however, of the years 1826 and 1828 incluzive, in which the coinage of gold was inconsiderable, and may, therefore, in a general estimate, be disregarded, the expense, excluding wastage, it appears, may be stated at one per cent., with a very near approximation to exactness-the wastage, as before mentioned, being the fourth of one per cent., and making the whole expense for that period about 14 per cent., which may be considered as the average for a silver coinage of about $2,300,000 yearly. This per centage of expenditure will diminish with the amount of issues, a portion of the annual charges of the Mint being fixed. The gradations of reduction cannot, however, be now determined; but it is believed that the expense on a coinage of four millions of dollars may be effected at something less than one per cent., including wastage.

There is no apparent difference in expense between deposits of the ordinary character of bullion, and those of foreign coins usually received at the Mint. Both unwrought bullion and coins, which require to be melted before assaying, are to that extent more expensive to the United States thao deposits in which this may be dispensed with, the materials and labor thus required being a part of the general expenses of the Mint; but the difference eludes notice by its minuteness, when singly designated.

9th. Our present force is adequate to the coinage of 600,000 half dollars monthly. This result will be in some measure affected by the attention given to the smaller denominations, but so that the amount of the years' coinage will accord nearly with the above. This is exclusive of gold, the amount of which, if unusually large, will somewhat impede the silver coinage... . | 10th. The new mint will be competent, no doubt, to the coinage of ten inillions, in due proportions, of the different denominations of our coins, if bullion be regularly supplied. Its utmost power I would not now venture to indicate. The coinage will, it is hoped, commence as early as August next. The fourth of July was designated as the time, when the corner stone was laid; but this, I apprehend, cannot be accomplished. The establishment will not probably be in readiness for vigorous operation till near the close of the present year. It is not relied on to promote the issues of this year more than will be equivalent to the retardation of a removal."

11th. Three thousand dollars, in dollars, most probably more, may be coined in the same time as two thousand in half dollars, with an equal number of presses; and the annual expense, wastage excepted, would be about the same. The wastage per cent. on dollars would be less than on the lower denominations, but the difference would be unimportant between dollars and half dollars.

12th. It is anticipated that the demand for coinage may be met by the new Mint, with a delay rarely exceeding twenty days. Prompt payment, - as soon as the value shall have been ascertained, will, it is supposed, be praclicable for all deposits of moderate amount.

13th. The value of a deposit requiring only a single assay is generally ascertained, and a certificate issued, in twenty-four hours. If there are several parcels, and especially if they require previous melting, the time is ex. tended to two or three days, and if the number be large, and also require melting, the delay will occasionally extend to four or five days..

14th. The banks generally cash Mint certificates at a deduction of the half of one per cent., if the coinage is not apprehended to be very remote: the Bank of the United States, without regard to the interval to elapse before roinage, receives Mipt rertificates at that deduction."

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15th. The assayer takes a small piece from each bar or separate mass at bullion, and estimates the whole value from the assay of that piece. The result, in regard to the mass generally, confirms the correctness of the estimate deduced from the assay thus made. In a given instance this will be, occasionally, incorrect; on an average, however, it will be found liable to no important failure. In the process, now frequent at the Mint, of parting gold and silver, the small assay is tested by an actual analysis of the whole mass; permitting the two metals to be separately weighed. This is a happy experiment of the correctness of the assay, and the accordance with it is generally satisfactory. It may be remarked that the purity of our coins is not dependent výholly on the assay of bullion or foreign coins when deposited; all ingots prepared therefrom for coinage are, before delivery to the chief coiner, assayed again, and returned to the melting pot when found to require it.

Toreign coins of well established character, when deposited, are estimated on their known fineness, the assay being from time to time employed to as certain their uniformity in this respect. This is particularly convenient and almost indispensable in our present establishment: the delay of melting large deposits of coins would be sensibly felt in the business of the year. In the new Mint this difficulty will be removed, and, without retarding the ordinary operations, coins can be very generally melted before assaying.

16th. The mode of assaying hitherto pursued for silver has been that of çupellation. It is not perfectly constant in its results. A liability to errors amounting to the half of one per cent. is well known to be involved in the process, if the ordinary directions for conducting it are relied on, without any corrective of its irregularities. This liability is, however, very much restricted by introducing into the muffle, along with the assays in question, another piece of determinate standard, and near the fineness of the metal tried. The causes which operate to render the assay incorrect extend their influence to the proof piece, and afford the measure of the corrections to be applied in the case—not a perfect, but a valuable correction.

The assayer of the Mint has acquired, by long experience, a facility in judging of the condition of his muffle, which, frequently confirmed by the employment of the proof piece, renders his results more constant and exact than are usually obtained, I apprehend, from this process.

The heat employed is not determined by any form of pyrometer. It is, during the early part of the process, insufficient to sustain fine silver in a state of fusion. Towards the close, the heat is excited as the alloy is dissipated, so as to keep the silver fused when it becomes fine, though it would not, during the process, melt fine silver. This appears to be the desirable point of temperature. At a lower heat, the assay would become fixed and constant before it would become fine, and the process thus be defeated. The eye of the assayer judges when the silver has become divested of its alloy. Too high a temperature urges on the process, and wastes a portion of the silver.net

The difficulty of measuring high degrees of heat aceurately occasions wide discrepancies in the temperature assigned by different authorities as the melting point of silver. It is probable that the final temperature of a suceessful assay may be about 4000 degrees of Fahrenheit.

The proportion of lead to fine silver, in our ordinary assays, is about 7 grains of lead to one of silver. The common form of cupel is employed,

No silver assays have been made here in the humid way. The subject having, however, attracted the attention of foreign assayers and chemists, and the probability being great that they may be led to select this method, under some modification, in preference to cupellatior, a series of experiments will be considered worthy of attention with us, though the practice before mentioned, of recurring frequently to a proof piece, renders us less sensible of the necessity of a change in this regard. “A facile process in the humid way would, however, be decidedly preferable.

18th. The assays requested have been completed, and the results thereof will be seen in table B. In regard to a particular experiment, of performing a part of those assays with a portion of lead, exactly one-third of the fine silver, the suggestion has been exactly complied with. This quantity of lead forms, however, no envelope for the metal tried. An assay piece thus exposed was uniformly reduced about five pennyweights below those enveloped in the usual form with lead, and placed in the same muffie. After three trials with similar results, the experiment was discontinued, as it some; what interfered with the equal arrangement of the other assay pieces.

Nine pieces of each of the coins mentioned by the committee, taken with. out selection, except as to dates, the latest being sought for, were severally divided into three sections. Assay pieces were made from each section of the same coin, and exposed in the same muffle, successively, to the several grades of temperature. The result given under each degree of temperature in the table, is, therefore, the average of three assays, thus made, of three different specimens of the same coin.

In all cases the same coin was experimented on successively, through the different grades of heat, without interruption, the heat being further raised for each succeeding experiment.

The proof piece, of the fineness stated, was always introduced along with the assay piece. The variable effect on this proof, under a temperature intended o be the same, indicates the difficulty of adjusting this point, and the irregularities of result which this uncertainty of temperature involves. In the low and medium grade of temperature, which may be considered as the extreme limits of our ordinary assay heat, the highest error of the proof piece from its actual fineness, it appears, is 15 grains in excess. This is an error of 15 grains fine silver, in the troy pound of 5760 grains standard, being a fraction over the fourth of one per cent. The assay piece, in this case, without the proof to correct it, would have given an enormous result to that extent.

The average of the low and medium temperatures, it appears, is very nearly true in the proof piece; the greatest deviation from the fineness due to it, combining the two assays, scarcely exceeds two grains. The true state of the coins will, therefore, be but derived from a similar average If this be applied to the dollar of the United States alone, taking care to correct the assays by the proof, this coin appears 14 grains in the pound too fine. Applied in the same manner to the half dollar, this coin appears 5-6 grains inferior. The mean is 4 is, or the iti of one per cent nearly. The same measure being applied to the five franc piece, this coin appears 3 grains in the pound inferior to its standard, which is about the of one per cent.

The result in regard to the Peruvian and Mexican dollars requires parti cular explanation. One section of the former of these coins, gave constantly, in all temperatures, a degree of fineness higher, by nearly one and a half

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pennyweights, than the ordinary grade of that coin. In the Mexican, on the contrary, one section gave constantly a result about one dwt. 18 grains inferior. In both descriptions, the other two sections gave results conformable to our ordinary experience. I have considered it best to report on both precisely as the facts occurred, without resorting to a change of specimens. There is not the smallest ground for supposing that either is any thing but an accidental variety. They exhibit strikingly the irregularities to which the ordinary assay is liable, if not cautiously conducted, and with a frequent reference to a proof standard. All the specimens, both of Peruvian and Mexican dollars, were of 1830, as were also the five franç pieces, except two of 1829, but equally perfect.

The inquiry respecting the expediency of making certain foreign coins a Jegal tender is not probably intended to be addressed to me. I shall be excused, however, for expressing briefly that the condition of the Spanish dol-. lar current at the present day renders its rejection probable, as a tender, and exposes those institutions which are liable to be called on for large payments. lo much embarrassment, while they may be well supplied with other dollars, worth more than their nominal value. The extension of the tender beyond the Mexican dollar will not, it is presumed, be necessary. That coin abounds in our country to an extent, probably, twofold the amount of all the other dollars of the new American States. It has become familiar to us, and is decidedly of more intrinsic value than the Spanish dollar has been for the last twenty years. In two or three years, so many of the Mexican dollars, which are profitable for coinage, will reach the Mint, that the issues therefrom will place our currency beyond the reach of further embarrassment.

The amount of our own coins now in the United States cannot much exceed seventeen millions of dollars. This may be expected to be doubled in three years after the completion of the new Mint. It could be much more rapidly done, if bullion should be abundantly and regularly supplied; but time will be required to solicit those coins from their distant position to the Mint, unless the Government should adopt the policy of supplying bullion by a direct operation.

If the Mexican dollar be made a legal tender, it is presumed it will be in the same terms as those used in relation to the Spanish dollar, viz. at 100 cents each, provided the weight thereof be not less than 17 dwts. 7 grains. There will thus be a sufficient inducement of profit on their coinage to compensate the banks for presenting them at the Mint. They will be worth - from 4 to 5 mills above their legal valuation.

The five franc pieces associate so inconveniently with our decimal denominations, that they have never been a popular coin. If, however, it should be fleemed necessary to make them a legal tender again for a limited time, it is proper to observe, that the law by which they were formerly made so involves an incongruity. They were made a legal tender at $i 16 per ounce, and also at 93 cents 3 mills each, provided their weight should not be less than 16 dwts. 2 grains. They never weigh this. It is above their weight when issued from the Mint. It would seem judicious to have an inducement for the recoinage of five franc pieces, nearly equivalent to that of the Mexican dollar. The valuation of $1 16 per ounce will have this effect, their valuc being very nearly $1 16.4 per ounce. If made a tender by tale at 93 cents, provided their weight be not less than 16 dwts, 1 grain, a similar

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