The isolation and identification of the anti-black tongue factor.

The preparation of concentrates of the antipellagra vitamin which were active in the prevention of pellagra-like symptoms in chicks and the cure of black tongue in dogs was described previously (1). In this paper we wish to report additional work on the purification of the vitamin which led to the demonstration of the activity of nicotinic acid and nicotinic acid amide in the cure of canine black tongue.