Colt made three versions, and the "3rd Model" has a magazine disconnect.
Do you know how to field strip the gun? If so, break it down and look at the guide rod, for the recoil spring.http://www.marstar.ca/images/Colt32num.GIF
Part #12 in this picture. See the teat on the back end of it? That teat goes through a hole in the frame and pushes this thingy backwards, into the magazine well. The thingy (don't you love technical terms?) being pushed back blocks the trigger. Putting the mag in pushes the thingy forward, and unblocks the trigger.
If your guide rod does not have a teat on it, then you either do not have a gun with a magazine disconnect, or someone has replaced the guide rod, to disconnect the disconnect feature.
If your rod does have the teat, you can either grind the teat off (I don't suggest this, as it modifies your gun, and lowers the value), replace the guide rod with one of the earlier models that don't have the teat, or do like I did, which was cut a 16d nail to size, polish it to remove any burrs, and cold-blue it to prevent rust. If I ever want to make the gun "original" again, I just need to replace the nail with the original rod.
If you just want to check your gun's trigger, without having a magazine, you can stick a knife blade (or something similar) up the magazine well, and push that thingy forward.
Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297
I always take precautions.
Beware the Evil Bullet Fairies.