Abstract: A cassette for a stack of superimposed sheets of X-ray film has a bottom wall, four sidewalls disposed at the upper side of and defining with the bottom wall a rectangular or square chamber for at least one stack of sheets, and a cover which is pivotally connected to one of the sidewalls and is movable between an open position to afford access to the chamber and a closed position in which it cooperates with the sidewalls to prevent penetration of light into the chamber. The top surface of at least one sidewall is provided with one or more markers (e.g., in the form of a row of triangular indicia) made of or containing a material which permits ready visual detection of the marker in a darkroom whereby a person looking at the marker can ascertain at a glance whether or not one or more uppermost sheets of a stack in the chamber are misaligned so that they overlie the top surface or surfaces of one or more sidewalls and must be reoriented prior to pivoting of the cover to closed position.

Abstract: An air humidifier for moisturizing air in a dry treatment device for a photographic material comprises a housing having inner walls and provided with at least one air aspiration openng and at least one air discharge opening, a moisturizable element arranged in the housing, a unit for blowing air through the moisturizable element and then through the air discharge opening to a space to be moisturized and also located in the housing, the moisturizing element being formed as a rotatable disc arranged before the air discharged opening and provided with rotary drive unit for its rotation, a light protective plate arranged between the moisturizable disc and the unit for blowing air and at least locally spaced from the inner wall of the housing so as to form throughgoing air passages, and light separating parts provided behind the throughgoing air passages and before the moisturizable disc.