The spectra of various sources are shown on http://www.google.co.uk/imgres?imgurl=http://bmb.lcd.lu/science/compared_spectra.jpg&imgrefurl=http://bmb.lcd.lu/science/index.html&usg=__MGZyK8rBgvGZkgfu9Fz1ViJW09M=&h=357&w=388&sz=12&hl=en&start=17&um=1&itbs=1&tbnid=MkaZz_BjLo50ZM:&tbnh=113&tbnw=123&prev=/images%3Fq%3Dmercury%2Bvapor%2Blamp%2Bspectrum%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DX%26rls%3Dorg.mozilla:en-US:official%26tbs%3Disch:1.

The link maker didntt like the address I think.

Stu