N sub2 H sub4 derivatives: The f.p. of N sub2 H sub3 Me (I) wa s calculated as -56.08 deg. C; the eutectic for the system I-N sub2 H sub4 occured at 85 wt.-% I and -64 deg. C. Neutralizing I.H sub2 SO sub4 with KOH yielded 95. 6% I. The formation of trimethylazonium bromide in the reaction of N sub2 H sub4 and MeBr was not prevented by using 0.5 M Me Br to 1.0 M N sub2 H sub4 or by lowering the reaction temperature to 0 deg. C. The method adopted for seperating N sub2 H sub4, unsym-dimethylhydrazine, and I utilized the formation of complexes with BzH. Thermal decomposition of MeNO sub2: Analyzing the contents of heated ampoules with a mass spectrometer appeared a promising method for studying the decomposition mechanism. The apparatus for spectrometer determinations was completed. Engine spectrometer determination was completed. Engine test program: In fourteen 100-lb.-thrust tests, the 13% solution of LiBH sub4 in N sub2 H sub4 and O had a maximum I sub sp value of 256 lb.-sec./lb., which was 94% of the theoretical maximum. All runs were characterized by copious deposits of gray or white oxides, which almost covered the chamber, nozzle walls, turbulator, and injector face.