CodeIgniter - how to load library?

I'm using an older version of CodeIgniter when the application folder was still in system/application. I have pulled the application folder out of system such that the application folder is now at the same level as system.

BEFORE:

/system/application/

NOW:

/application/
/system/

Question: how do I now load libraries? In one of my controllers, I tried this:

$config['protocol'] = 'sendmail';
$config['mailpath'] = '/usr/sbin/sendmail';
$config['mailtype'] = 'html';
$config['charset']  = 'iso-8859-1';
$config['wordwrap'] = TRUE;

$this->开发者_JS百科;library('email', $config);

The application dies when it tries to load the email library. Suggestions?

You are missing load i.e. You need to write $this->load->library('email', $config);