1. It was observed clinically that tactile gnosis varies directly with the sudomotor function in the hand.

2. Two methods of fingerprinting were elaborated to register the sudomotor function, and consequently the tactile gnosis objectively. They are sensitive, simple to perform and suitable for clinical work. Their anatomical background, sources of error and relative value are discussed.

3. The correspondence between the sudomotor function, determined with these methods, and the tactile gnosis was established. This was done by, firstly, comparing the regions which did not perspire with the ones which became insensible on total denervation of a region of the hand; secondly, by examining the loss of function after nerve block; and thirdly, by comparing the tactile gnosis and sudomotor function in cases of residual median nerve defect.

4. These two qualities do not accompany each other in skin grafts. Grafts regain sudomotor function but never tactile gnosis.

5. A practical procedure for determining the functional value of the cutaneous sensibility in the hand is described.

6. Cases are related illustrating the usefulness of objective study of the sensibility in the hand.