854 Wisconsin Academy of Sciences, Arts, and Letters . 
dissolves readily in alkalies with a yellow color. In alcoholic 
solutions it yields a brownish green color with ferric chloride, 
an orange yellow color with lead acetate and a reddish brown 
precipitate with lime or baryta water. It reduces an ammonical 
silver solution in the cold, Fehling’s solution when warmed. 
Isorhamnetin, — Quercetin-3'-monomethyl ether, or 
Trihydroxy-1, 3, 4' -methoxy-3'-flavonol. 
Isorhamnetin was first isolated by Perkin and Hummel * 1 in 
1896, from the petals of the yellow wallflower, Cherianthus cheri, 
and later by Perkin and Pilgrim 2 from the flowers of Delphinium 
zali. Because by oxidation in alkaline solution isorhamnetin 
yields vanillic acid, Perkin 3 concludes that it has the methoxy 
group in position -3'- as given above. 
Isorhamnetin occurs, as stated above, in the flowers of cher¬ 
ianthus cheri and of Delphinium zali, along with quercetin. It 
crystallizes in masses of fine, brilliant yellow, needle like cry¬ 
stals which are difficultly soluble in boiling alcohol and in acetic 
acid. With lead acetate it gives an orange red preciptate, with 
ferric chloride a greenish black coloration. Fused with alka¬ 
lies it yields protocatechuic acid and phloroglucin. 
Rhamnazin, — Quercetin-3, 3’-dimethyl ether, or 
Dihydroxy-1, 4'-dimethoxy-3, 3'-flavonol. 
Rhamnazin was first found by Perkin 1 in ‘ ‘ Persian berries, 
the fruit of various species of Rhamnus, while trying to purify 
rhamnetin, in 1895, and shown by him to be dimethyl-3, 3'- 
quercetin, as below. 
*Jr. Chem. Soc.. 69, p. 1566. 
2 Jr. Chem. Soc., 73. p. 267. 
8 Proc. Chem. Soc., 14, p. 56. 
1 Jr. Chem. Soc., 67, p. 496; 71, p. 819. 
