title: Find out what font is used to replace missing unicode characters
body: <p>I have <a href="http://u8.8u.cz/runy/" rel="nofollow">a javascript application</a>, that converts text in runes using the <a href="http://en.wikipedia.org/wiki/Runic_%28Unicode_block%29" rel="nofollow">Unicode rune chart</a>. The problem is, that some fonts do not contain the rune symbols.<br>
  Mozzila Firefox simply finds out the correct font and uses it for runes, instead of Goudy Medieval and Times New Roman. Google Chrome is not capable of doing that and displays black boxes instead of runes.<br>
  So my question is: </p>
  
  <ol>
  <li>How can I find out which web-safe font supports these symbols?</li>
  <li>Can I find which font <strong>does Firefox use</strong> at any point of the document?</li>
  </ol>