A brief report of this investigatio

A brief report of this investigation was given at the meeting of the
American Chemical Society at Rochester, New York, September 10, 1937.
obtained, after dehydration, contains approximately 16 per cent
of pigment. Purification is effected by precipitation with lead
acetate and subsequent separation in indistinctly crystalline form
from acidified aqueous solution, or by precipitation from alcohol
solution with peroxide-free ether.