The Numismatic Bibliomania Society

PREV ARTICLE       NEXT ARTICLE       FULL ISSUE       PREV FULL ISSUE      

V21 2018 INDEX       E-SYLUM ARCHIVE

The E-Sylum: Volume 21, Number 39, September 30, 2018, Article 7

CHEMICAL ANALYSIS OF EARLY U. S. SILVER COINS

The first results of a project begun in March, 2015 to investigate the composition of early U.S. silver coins have been published. David Finkelstein and Christopher Pilliod have released a paper summarizing the first phase of a multi-phase project to determine the chemical composition of 1794 and 1795 US silver coins.

The pair gave a presentation at the John Reich Collectors Society (JRCS) General Meeting during the ANA World’s Fair of Money in Philadelphia. Here's an excerpt from the paper's introduction, and a link to the complete document on the Newman Numismatic Portal. -Editor

Most numismatists will agree that the single most important Mint related legislation in our nation’s history was the Mint and Coinage Act of April 2, 1792. In addition to establishing the first Mint of the United States, one of the key aspects of this law was Congress’s mandate for the composition of the silver coins. Per Section 13:

“And be it further enacted, That the standard for all silver coins of the United States, shall be one thousand four hundred and eighty-five parts fine to one hundred and seventy-nine parts alloy; and accordingly that one thousand four hundred and eighty-five parts in one thousands six hundred and sixty-four parts of the entire weight of each of the said coins shall consist of pure silver, and the remaining one hundred and seventy-nine parts of alloy; which alloy shall be wholly of copper.”

The law specified that silver coins were to contain 1485 parts of pure silver and 179 parts copper alloy. This equated to a standard of 1485 / 1664 or 89.24278% or 89.24+% pure silver, and 10.75722% or 10.76-% copper alloy.

Multiple documents stored within the National Archives and Records Administration (NARA) and the Library of Congress indicate that under the leadership of Mint Directors David Rittenhouse and Henry William de Saussure, some or all of the 1794, and most or all of the 1795 dated silver coins were produced to a 90% silver and 10% copper standard. Then, effective November 6, 1795, under the leadership of its third Director, Elias Boudinot, the Mint reverted to the 89.24+% silver and 10.76-% copper standard.

The first phase of a multi-phase project was just completed to determine:

1. what elements and percentages are in the silver coins of 1794 and 1795,

2. what elements and percentages are in the copper coins of 1794 and 1795,

3. whether the Mint attempted to refine any of the silver bullion deposits made during 1794 and 1795 to a standard of 89.24+% silver and 10.76-% copper as per the Mint and Coinage Act of April 2, 1792,

4. whether the Mint attempted to refine any of the silver bullion deposits made during 1794 and 1795 to a standard of 90% silver and 10% copper, thus violating the Mint and Coinage Act of April 2, 1792,

5. whether Mint personnel were capable of achieving a refining target of 89.24+% silver and 10.76-% copper,

6. whether Mint personnel were capable of achieving a refining target of 90% silver and 10% copper,

7. the technologies available to 18th century precious metal refiners, and

8. the Mint’s practices for refining silver bullion deposits.

This project began in March, 2015. Thanks to support from the Eric P. Newman Numismatic Education Society, Heritage Auctions, and the Terry Brand Estate, modern chemical analysis technologies were used to determine the chemical compositions of 1794 and 1795 silver and copper coins. Based on the compositional results, statistical analyses were performed, and preliminary conclusions were made.

To read the complete article, see:

Chemical Analysis of 1794 & 1795 U. S. Silver Coins – Part 1 (https://nnp.wustl.edu/library/book/554528)

E-Sylum readers got a preview of the methodology last month in a report from Newman Numismatic Portal Project Coordinator Len Augsburger. -Editor

1795-105-before 1795-105-after

Before and after pictures of a 1795 O-105 Half Dollar. The center piece in the after picture was sent for ICP-AES analysis.

To read the complete article, see:

RESEARCHERS PUT EARLY SILVER COINS TO NEW TESTS (http://www.coinbooks.org/v21/esylum_v21n33a12.html)
Charles Davis ad01


Wayne Homren, Editor

Google
 
NBS (coinbooks.org) Web

The Numismatic Bibliomania Society is a non-profit organization promoting numismatic literature. See our web site at coinbooks.org.

To submit items for publication in The E-Sylum, write to the Editor at this address: whomren@gmail.com

To subscribe go to: https://my.binhost.com/lists/listinfo/esylum

PREV ARTICLE       NEXT ARTICLE       FULL ISSUE       PREV FULL ISSUE      

V21 2018 INDEX       E-SYLUM ARCHIVE

Copyright © 1998 - 2012 The Numismatic Bibliomania Society (NBS)
All Rights Reserved.

NBS Home Page
Contact the NBS webmaster
coin