The colours of roses

Abstract

A spectrophotometer record of the absorption spectrum of an acetone extract of the pigments of a rqd rose is reproduced. It exhibits three peaks respectively in the yellow, in the green and in the greenishblue regions of the spectrum, thereby indicating the identity of the pigment as florachrome B. The features observed in the record enable it to be inferred what colours a rose would exhibit if it contained varying quantities of the pigment. These are in agreement with the facts of observation