This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Carbonate of ammonium should be preserved in well-stoppered bottles in a cool place. White, translucent masses, consisting of bicarbonate (acid carbonate) of ammonium and carbamate of ammonium, losing both ammonia and carbonic acid gas on exposure to air, becoming opaque and finally converted into friable, porous lumps, or a white powder (acid carbonate of ammonium). The salt has a pungent, ammoniacal odor, free from empyreuma, a sharp, saline taste, and an alkaline reaction. Soluble in 4 parts of water at 15° 0, (59° F.), and in 1.5 parts at 65° 0. (149° F.). Alcohol dissolves the carbamate and leaves the acid carbonate of ammonium.