Ever wonder how the smoke effect was made in "I Dream Of Jeannie"? It's actually a really interesting practical effect that involves a bit of chemistry!
So the effect relies on a chemical reaction between manganese dioxide (a dark black powder) and hydrogen peroxide (the stuff you can buy at the drug store, but like, much more concentrated). When manganese dioxide is mixed with hydrogen peroxide, the peroxide decomposes to give - Water! And also, oxygen and a whole lot of heat. The heat vaporizes the water, and you get a bunch of steam. The fact that this happens VERY quickly means you get a lot of steam FAST.
So on I Dream Of Jeannie, what they'd do is empty out a tea bag, and fill it with manganese dioxide. Then, they'd put some hydrogen peroxide in the bottle, and hang the teabag by the string over the lip of the bottle. Insert the stopper to hold the string of the teabag in place, and then all that one needs to do is open the bottle and... POOF!
Here's a link to a video of me doing this in the lab, using a clear volumetric flask as a bottle stand-in (The video is quite old, so please forgive the quality).
