Emily Dickinson Lexicon

DA-GUERRE'O-TYPE, n. [dager'rotype; from Daguerre, the discoverer.]

A method of fixing images of objects by the camera obscura. A copper sheet, plated with silver, well cleaned with diluted nitric acid, or polished, is exposed to the vapor of iodine, which forms a very thin coating. This sheet is placed in the camera obscura, in which it remains eight or ten minutes; it is then taken out and exposed to the vapor of mercury; then heated to 167° Fahrenheit, and the images appear as by enchantment.