828 Wisconsin Academy of Sciences, Arts, and Letters. 
The third class is a small one made up of the pigment form¬ 
ing substances brazilin and haematoxylin and the pigments 
brazilein and haematein. 
I. Pigments referable to Diphenyl olefins and homologues. 
It was pointed out in connection with the pigments referable 
to hydrocarbons of the formula of saturation C n H 2n _ 14 that a 
conspicuously large number of these colored compounds were 
derivatives of the diphenyl and diphenyl methane series of hy¬ 
drocarbons. The same relationship is found to exist among the 
pigments referable to hydrocarbons of the degree of saturation 
C n H 2n _ 16 , for here we find a considerable number of compounds 
referable to the diphenyl olefin series of hydrocarbons, having 
as their initial members diphenyl ethene, diphenyl propene, and 
diphenyl butene. 
I. Pigments referable to the diphenyl olefin series of hydrocar¬ 
bons. 
A. Diphenyl ethene. 
1.) Tolyl-ethophenyl-ethene. 
Berberin. 
B. Diphenyl 1, 3, propene. 
1.) Flavone derivatives. 
Chrysin 
Tectochrysin 
Apiginin 
Acacetin 
Galangin 
Galangin meyhyl ether 
Luteolin 
Luteolin methyl ether 
Lotoflavin 
Fisetin 
Kaempherol 
Kaempherid 
Quercetin 
Khamnetin 
Isorhamnetin 
Bhamnazin 
Morin 
Myricetin 
Gossypetin 
