Problem embedding SVG graphic on web page

I have a simple web page where I include an SVG graphic created with
Inkscape using the following mark-up:

<p>
	<img src="myGraphic.svg" alt="myGraphic description" />
</p>

When I display the web page with firefox, it just prints the "alt"
description in stead of rendering the SVG graphic; when I open the SVG
graphic file directly with firefox it renders it perfectly. Where am I
going wrong?

Opera, Chrome and Safari all render the SVG graphic correctly when the
web page is opened with them.