May I suggest some further reading??
http://www.mises.org/rothbard/genuine.asp
Edited with an Introduction by Llewellyn H. Rockwell, Jr. Copyright © 1992.
All you need is an foreword by Lyndon LaRouche and an afterword by Justine Raimondo.
Footnote 12 invalidates the author's entire argument and he doesn't even see it. As silver and gold fluctuated in demand, the feds constantly re-defined how much gold a dollar was worth. In other words, the DOLLAR was treated as the constant, and the gold was treated as the variable.
This is because the true wealth of a nation is its manufacture and trade, NOT how much gold it has in its treasury. Money is simply the method whereby the value of trade is quantified among people whose items of trade do not coincide to the point where a barter system is possible.
For example, I write software manuals for a living. That is a skill I cannot barter for a new car. However, I can barter that skill for a company that makes software. That company can then barter with others who are interested in their product.
Money, whatever form it takes, allows us to create a common denominator that is valid for trade irrespective of whether the buyer and seller have skills or materials the other desires.
The car maker does not desire my writing skills, but he WILL take my money, which is a UNIVERSAL barter for my skills. I have bartered my skills to someone who IS interested for this UNIVERSAL barter. I can then take it and use it to barter with someone who has no interest in my particular skills.
When you understand this, you understand that the value of money is determined not by the paper it is printed on nor the gold that may back it but on the perceived worth of labor by those engaged in trade of those labors and products of that labor.