If you feel comfortable editing the wp-config.php file and don't want to use a separate database, you can make a change that lets you use the same database for multiple wordpress installs. Open wp-config.php for the newer installation in a text editor and look for this section:
// Change the prefix if you want to have multiple blogs in a single database.
$table_prefix = 'journal__'; // example: 'wp_' or 'b2' or 'mylogin_'
Yours will likely say "wp_" (the text that says "journal_" is because I copied from one of my installs) -- just change that text in the quotes to something else, anything else, and that installation will be able to co-exist happily in the same database.