Instantaneous portraits can now be taken on collodion by a very ingenious French invention. The person whose portrait is to be taken is placed at some distance off, in front of the lens, and the operator, while conversing with him, pulls a trigger. By so doing a newly invented cap (obtwratewr) turns on its own axis, and in its rotary movement allows the light and the image of the sitter to pass through a hole twice the diameter of the lens. The portrait is obtained in the fraction ol a second, and for quickness can only be compa-red?to electricity. It isbut justice to the inventor of thec,ollodion (M. Bertsch) tostatethat the rapidity is owing to its extreme sensitiveness, which rendered it necessary to use the above instrument. By the ordinary method the collodion would be spoiled by the light, however skilliul the manipulator, before the portrait could be taken.