Yes, you usually tell if it's an HPS or MH type bulb by the appearance of the light...MH is whitish and slightly blue, HPS will make you think of an evening sun...yellowish light. Also you may be able to tell by looking at the um I know it's not the electrode, but the thingy (soooo technical...I'm buzzed, help me fellow light guys!) The shorter electrode is usually a MH bulb and may say Metal whatever on the end, and the longer electrode (where the actual light is emitted) is longer and will usually have sun whatever on it on the end. Hope this helps but if you just have the one, I don't know what you can compare it to...the light (yellow or blue) should give it away tho...

As the others have said, just start the babies out with easy gentle light at a distance for the first few weeks and let them get some roots going and you'll be fine