You can go into the html editor and insert this code where you want the different font to begin:
<div style="font-family:"Times New Roman",Georgia,Serif;">
and then where you want the different font to end (or even at the end of the post):
For more information, read this page for more information about specifying fonts.
I know this seems like a bit of work (in truth, it’s not the most elegant solution), but if you want different fonts on different pages, this is probably the easiest way to accomplish that.
Also, keep in mind that if readers don’t have a font you’ve specified installed on their computer, they won’t see that font. See this page for more information.