Proceedings of the American Academy of Arts and Sciences. 

 Vol. XXXV. No. 11. — January, 1900. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



ON CERTAIN COLORED SUBSTANCES DERIVED FROM 



NITR O COMPO UNDS. 



THIRD PAPER. 



By C. Loring Jackson and F. II. Gazzolo. 



