first-child doesn't work here. what am i doing wrong?
<p>I'm trying to add classes via jQuery. Funny thing is, "last-child" works but "first-child" doesn't. Is there anything I'm doing wrong here?</p>

<pre><code>$("#testimonials-content article:first-child").addClass("first");
$("#testimonials-content article:last-child").addClass("last");
</code></pre>

<p>So, in that example, the second line works. That is, the class gets added in the markup. However, nothing happens for the first line.</p>
