The object of the present Investigation was to obtain chemical tests which would enable a rapid and accurate identification of tubers to be made. The importance of such a method of identification is obvious from a consideration of the following points. Under the regulations of the Ministry of agriculture and the Department of agriculture for Scotland varieties of potatoes used for seed purposes nave to reach a certain standard of purify and the growing crops are inspected for this purpose. After the crops nave been harvested however, confusion may arise from the similarity in appearance of the tubers of different varieties and a rapid and certain method of discrimination would in such cases be very valuable. Work of this nature has already been carried out by McIntosh whose investigation although of a preliminary nature, made clear the possibility of differentiating potato varieties by chemical reactions.