Tonic is a sideboard and bookcase in oak, designed by Reinhard Dienes. It is assembled without screws or the use of tools. Tonic can be used in two different positions; horizontal as a sideboard, or vertical as a bookcase. To achieve this change the legs are simply taken out of the sockets and replaced in the desired position. The dark legs appear to be sketched and give Tonic the self-evident charm of simplicity and lightness.