From http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1401882

A great paper, BTW:

“In response to a panic, banks would jointly suspend convertibility of deposits into currency. Coincident with this, clearinghouse member banks joined together to form a new entity overseen by the Clearinghouse Committee. As Swanson (1908b, p. 221) put it, describing the crisis of 1860, there was “the virtual fusion of the fifty banks of New York into one central bank” (p. 221). The clearinghouse would also cease the publication of individual bank accounting information (which banks were normally required by the clearinghouse to publish in the newspapers) and would instead only publish the aggregate information of all the members. Finally, banks issued loan certificates, which were first used to replace currency in the clearing process, starting with the Panic of 1857. But, in the Panics of 1893 and 1907 the clearinghouse issued new money called clearinghouse loan certificates directly to the public in small denominations.”