the genetics of the beet, and also because the intensity of coloration
of the root is of importance in determining the value and use
of this crop, a study of betanin is being made at this Station. No
information with respect to the light absorption of the pigment
was available in the literature but, if preparations of reproducible
physical properties could be secured, it seemed probable that a
simple calorimetric method to determine the quantity in the tissue
might be developed, of sufficient accuracy to have significance for
genetic and agricultural studies. The present communication
describes a procedure for the preparation of samples of pigment
that have a constant extinction coefficient. The method is based
on the observation that a precipitate that contains most of the
pigment separates when an acid alcohol extract of the dried root
tissue is neutralized with lithium hydroxide. The concentrate so