Abstract: A device for restricting the movement of a living, microscopical organism being viewed with the aid of a microscope including a base mounting a first glass element upon which an organism is placed and a second glass element parallel to and over said first glass element and mounted on an arm extending from a hub on a columnar adjusting mechanism. The adjusting mechanism includes a column mounted on said base normal to the plane of said first glass element. A compression spring is mounted concentrically on said column and supports said hub which is movable vertically and rotably on said column. The hub is movable up and down the column by adjusting a knurled screw which is threaded into the column and bears on the hub through an isolation element which prevents the transfer of rotational force in either direction between the knob and the hub.