a device for the extemporaneous mixing of n constituents has n compartments , each having a first end and a second end on the opposite side to the first , each of the first and second ends being surmounted by a neck delimiting an opening . intermediate obturators separate each compartment in a detachable manner from the compartment or compartments which are adjacent thereto when the n compartments are placed on one another . an actuator is provided for ejecting the intermediate obturators for effecting the mixing of n constituents , and first end obturators and second end obturators are provided for obturating the end openings of the first compartment and of the n th compartment . one of the first or second end obturators has an opening for the dispensing of the mixture . the first and second ends of any of the n compartments can receive any of the said obturators .