"[B]anks have habitually created warehouse receipts (originally bank notes and now deposits) out of thin air. Essentially, they are counterfeiters of fake warehouse-receipts to cash or standard money, which circulate as if they were genuine, fully backed notes or checking accounts. Banks make money by literally creating money out of thin air, nowadays exclusively deposits rather than bank notes. This sort of swindling or counterfeiting is dignified by the term 'fractional-reserve banking,' which means that bank deposits are backed by only a small fraction of the cash they promise to have at hand and redeem."
Murray Rothbard, "Fractional Reserve Banking."
A clear, testable implication of the above quote--one of the loci classici of the belief, now widespread among fans of a certain sort of Austrian economics, that fractional reserve banking is fraudulent--is that the notes issued by fractional reserve banks have been indistinguishable from warehouse receipts. After all, if you are going to swindle people by "counterfeiting" something, you wouldn't be inclined to make the fakes obviously unlike the genuine articles, right?
Here are some images of (1) various warehouse receipts and (2) various banknotes. I draw my readers' attention to the language common to the specimens in each set. They will note how items in the first all make specific mention of the fact that valuables have been received "for storage" (or something like that); while those in the second merely "promise to pay" a sum on demand, making no reference to storage at all.
I leave it to those readers to then determine for themselves whether the evidence is consistent with the "clever swindle" theory of fractional reserve banking.
1. Warehouse Receipts: