(under subclass 564) Subject matter wherein the fluid is a gas or vapor.
(1) Note. This subclass includes an ammonia gas generator with means for containing a specific light-sensitive material in a specific orientation to allow treatment of the material by the generated gas.
(2) Note. See the note to "Fluid Treating Apparatus" in the main class definition.
SEE OR SEARCH THIS CLASS, SUBCLASS:
438, for subject matter related to daguerreotype photography.
, FOR 918, for a foreign art collection involving gaseous-type, fluid-treating apparatus.
SEE OR SEARCH CLASS
34, Drying and Gas or Vapor Contact With Solids, see (2) Note above.
