Nothing is more astonishing than the infinite variety of the human face, in which there is such a prodigious difference of complexion and feature; and where a difference of expression is almost always observed, even in those whose features and complexion are very much alike. Lopez de Vega somewhere says, that nature, sometimes weary of varying her works, copies herself, and produces two persons perfectly resembling each other.101 Such must have been the similitude between the two men who are the subjects of the following detail. History mentions several celebrated impostors, who, taking advantage of a likeness to some other person, have usurped their stations or their fortunes: but there is perhaps no instance of an imposture so long and so successfully carried on, as that which is here related.