Note 120 — Chapter VIII
Reading edition
On a change produced by Exposure to the Beams of the Sun, in the properties of an elementary substance, by Professor Draper; On the changes which bodies undergo in the dark, by Robert Hunt: Report of the Thirteenth Meeting of the British Association, vol. xii,—Description of the Tithonometer, an instrument for measuring the chemical force of the Indigo-tithonic rays: by J. W. Draper, M.D.—Philosophical Magazine, Dec. 1843, vol. xxiii.