26,749. Badische Anilin & Soda Fabrik. Nov. 29, 1910, [Convention date]. Ammonia. - Deterioration of the manganese used as the catalyst in the synthetic production of ammonia is prevented by the use of a mixture of nitrogen and hydrogen which has been freed from all traces of oxygen, whether free or combined. The gases may be so freed by passage over metallic sodium or magnesium nitride, or other substance that will decompose water and fix oxygen, and they may be subjected to a preliminary treatment by passage over heated palladium-asbestos, and calcium chloride. The same precautions must be taken if manganese nitride is used. Specifications 19,778/10 and 5835/11 are referred to.