AKA hand boiler. An exotic bit of hand blown glass with a bulb at top and bottom connected by some zippy tubing that spirals, loops, and/or jogs. In the closed system is some colored liquid (methylene chloride) that is very light. Hold the lower bulb in your hand and as the liquid is warmed it pushes through the loops to the upper chamber. When all the liquid is pushed out of the lower bulb, expanding air will bubble through the tubing making it appear that the liquid is boiling.
WARNING! The glass is fragile and the liquid is nasty. If you drop the thing on the kitchen tile, it will eat the finish off the tile and the stain in the liquid will permanently stain the floor, so don't let kids handle this item unsupervised.
These come in assorted colors. If you would like a specific color, please include the request in the comments section when you checkout, and we will do our best to accommodate your preference!
About 7" tall, it is a favorite in our stores.