Page:Journal of the Optical Society of America, volume 30, number 12.pdf/41



trichromatic coefficients. The last two columns list the dominant wave-length in millimicrons and the excitation purity in percent. The dominant wave-length in the case of purples is indicated by listing the wave-length of the complementary color.

We wish here to acknowledge our indebtedness to Professor Arthur C. Hardy, who suggested this undertaking and offered much helpful advice during the progress of the work. We are indebted also to for operating the spectrophotometer during the determination of the spectrophotometric data.