The essential parts of this contrivance are an electric centrifuge, some heavy twine and two flasks, one of about 50 c.c. capacity and the other large enough to carry the material to be shaken. The shells are removed from the centrifuge arms, one of which is replaced by the inverted 50 c.c. flask (h), which is held firmly in place by wiring over the flange at the mouth of the flask and about a thin piece of wood, cut to a suitable size and placed on the under side of the centrifuge arm. The shaking flask, g, is suspended by twine from a ring at a, the knot about the neck of the flask at f being a slip-knot to allow changing the flask without disturbing the whole apparatus. A cord is tied firmly to the cordaf at e, and fastened loosely about the neck of the flask h at c so that the flask can revolve in the grasp of the knot.