Note 121 — Chapter VIII
Reading edition
For several illustrations of this remarkable phenomenon, see On the Action of the Rays of the Solar Spectrum on Vegetable Colours, and on some new Photographic Processes; by Sir John F. W. Herschel, Bart., K.H., F.R.S.—Phil. Trans. June, 1842, vol. cxxxiii.; On certain improvements on Photographic Processes described in a former communication, and on the Parathermic Rays of the Solar Spectrum; by Sir John F. W. Herschel, Bart., K.H., F.R.S., &c., in a letter addressed to S. Hunter Christie.—Phil. Trans. 1843, vol. cxxxiv.