on Silver Iodide and Bromide. 277 
without difficulty in developing images received on such 
S 
The opinion also that silver iodide, in the absence of free 
silver nitrate, is comparatively insensitive, receives its disproof 
from the foregoing investigation, which decisively shows that 
washed films of silver iodide possess a high degree of sensitive- 
ness to white light, and some sensitiveness to the less refrangi- 
ble rays: in either case a higher degree than silver bromide. 
Excitina AND ConTINUING Rays. 
of their preparation, some chance effect of light sufficient to 
i this was after- 
ward continued only, not originated, by the colored light to 
* La Lumiére, vol. ii p 76. 
