Tutorial Find and Wrap Ampersands
Load this plugin. Then:
$("body *").replaceText( /&/gi, '<b class="ampersand">' + '&' + '</b>' );
Change the selector as needed. That one is pretty intense.
Now you have a class name you can use to style them specially.
.ampersand {
font-family: Baskerville, Some Other Cool Font, Serif;
font-style: italic;
}