Abstract: A toy is disclosed for producing a simulated eruption. The toy comprises a container having a first chamber for holding a predetermined quantity of a first reagent and a second chamber for holding a predetermined quantity of a second reagent. The second chamber communicates with an upstanding convergent nozzle terminating at its upper end in an orifice opening to the exterior of the container. When the sidewalls defining the first chamber are squeezed, a portion of the first reagent held therein is forced through a connecting tube into the second chamber, where the first regent reacts with the second reagent to produce gaseous products. The elevated pressure thereby created within the second chamber causes the reagent mixture to be ejected from the nozzle orifice at high velocity. The toy may additionally comprise a simulated volcano landscape having a eruption tube depending from the volcano crater which receives at its lower end the tip of the nozzle.