Abstract: A laboratory mixer includes a test tube supporting cup means that translates in a circular path at high speed without rotating thereby creating an effective vortex in the materials in the test tube. A motor is mounted in the apparatus housing and supports a cylindrical metal block. The cylinder includes a circular cavity having a center located away from the axis of rotation of the motor and the cylinder itself. A pair of bearings located in the cavity support one end of a shaft that carries the test tube holding cup. The cup is allowed to translate in a circular path but is prevented from rotating by a restraining means that includes a restraining arm rotatably attached to the housing and a side arm connecting the restraining arm to the cup supporting shaft. The user rests the heel of his hand on a pressure sensitive touch plate while placing the closed end of the test tube in the cup. Pressure from the hand causes the touch plate to close a switch and automatically turn the mixer motor on.