690 



SCIENCE 



[N. S. Vol. XXXVII. No. 957 



Fritz Friedrichs: Binary Systems. II. Am- 

 monium Trinitride, Ammonia. 

 Ammoniuni trinitride forms with ammonia three 

 compounds containing, respectively, 1, 2 and 4 

 molecules of ammonia. All of these ammonates 

 show metastable melting points. The inversion 

 point of the diammonate into saturated solution 

 of the anammonous salt is at — 8.5°, that of the 

 tetrammonate into saturated solution of the di- 

 ammonate is at — 71°, and the euteotic is at 



— 87° with a concentration of 75 per cent. NH3. 

 The remarkable circumstance that the first two of 

 these ammonates NK,N3 . NH3 and NH^Nj . 2NH3 

 were never observed to exist together seems to 

 point toward a tautomerism of hydronitric acid. 

 It is not impossible then that the compound may 

 under certain conditions have the older ring for- 

 mula and under others the chain formula inde- 

 pendently suggested by Angeli, Thiele and Tur- 

 rentine. 



Fritz Friedrichs: Binary Systems. III. Am- 

 monium Bromide, Ammonia. 

 In extension of the work of Eoozeboom, who 

 studied a limited portion of this system, am- 

 monates containing, respectively, 1, 3, 6, 9 and 18 

 molecules of ammonia were shown to exist and 

 the boundaries of their fields were established. 

 All of the three ammonates with the exception of 

 the tri- and the octodecammonate possess meta- 

 stable melting points. The stable melting points 

 of the two just named were found at + 9.5° and 



— 79°, respectively. Inversion points were found 

 for the transition of NIIiBr • NH3 into saturated 

 solution of anammonous salt at + 36°, of NHjBr . 

 3NH3 into saturated solution of NH,Br ■ NH3 at 

 + 6.5°, of NHjBr . 6NH3 into saturated solution 

 of NH,Br . 3NH3 at — 69.5°, of NH^Br . 9NH3 

 into saturated solution of NUBr . 6NH3 at — 72°. 

 The zone of the saturated solution of the triam- 

 monate shows a pressure maximum of 1,600 mm. 

 at + 4°. 



As may be seen from the foregoing examples 

 the ammonates are entirely analogous with the 

 hydrates contrary to the recently expressed opinion 

 of Fritz Ephraim {Zeitschr. phys. Ch., 81 : 539- 

 542, 1913), who on the basis of an investigation 

 upon the ammonates of certain metallic salts (all 

 of which happened to be insoluble in liquid am- 

 monia) believed that he had discovered a funda- 

 mental difference between ammonates and hy- 

 drates, since the former apparently showed no 

 inversion points or definite fields of existence. 



Charles James and E. H. Holden: Sulphates of 



Yttrium. 

 W. A. NOYES: Nitro-Nitrogen Trichloride an 



Electromer of Ammono-Nitrogen Trichloride. 



Ordinary, or ammono-nitrogen trichloride hy- 

 drolyzes to ammonia and water. An attempt is 

 being made to secure nitro-nitrogen trichloride, 

 which should hydrolyze normally to nitrous acid 

 and water. To prepare the compound a mixture 

 of nitrosyl chloride, NOCl, and phosphorus penta- 

 chloride is passed through a porcelain tube heated 

 to 1000°-1200° and containing a little platinum. 

 A mixture of gases which can be condensed with 

 a freezing mixture or by cooling with liquid air is 

 obtained. The analyses indicate the presence of a 

 trace of phosphorus oxychloride, a small amount 

 of silicon tetrachloride, nitrosyl chloride, free 

 chlorine and, in some eases, about ten per cent, of 

 nitro-nitrogen trichloride. C. L. Parsons, 



Secretary 



SOCIETIES AND ACADEMIES 



THE AMERICAN PHILOSOPHICAL SOCIETY 



Mr. Herbert E. Ives read a paper before the 

 society on April 4, 1913, on "llluminants — Present 

 and Future." Modern illuminants are interesting 

 as applications of radiation laws and the science of 

 spectroscopy. The earlier illuminants, such as oil, 

 the candle, the gas flame, the carbon filament elec- 

 tric lamp, are approximations to black-body radia- 

 tion. Increased efficiency is with these dependent 

 on the attainment of very high temperatures. More 

 recent illuminants possess higher efficiency owing 

 to selective radiation, in accordance with Kirch- 

 hof 's law for selectively reflecting or transmitting 

 bodies. Thereby their radiation is relatively more 

 intense in the visible spectrum. This is the case 

 in the Welsbach mantle and the tungsten filament. 

 Another class of selective radiation is met in non- 

 temperature or luminescent sources, where isolated 

 spectrum lines or bands are the source of the 

 light. The mercury vapor lamp falls in this class. 

 The illuminants of the future will be marked by 

 greater efficiency, which may be attained through 

 selective radiation. Whether this will be brought 

 about by the use of gaseous energy or electrical, 

 or through little understood chemical processes 

 such as the firefly exemplifies, is of course as yet 

 unknown. Calculations show that if there were 

 none of the present enormous losses in transform- 

 ing the energy of coal into light something like 

 1,200 times as much light could be obtained for 

 the same consumption. 



