CHEMISTRY. 441 



a germanium ultramarine. The double fluorides of germaniuui are 

 strictly analogous to those of the other elements of the same group. 

 (Journ. Prakt. Chem. (2), xxxvi, 177.) The potnssium gerniaiiithio- 

 ride, K2GeF,;, is also studied by Nilson and I*ettersson, who sliow its 

 analogies with the silicotluoride. Crystalh>giaphic measurements by 

 I'aykull show it to be isonior|)hous with ammonium sili/;olluoride. (Be- 

 richte, xx, 1C9G.) In euxenite Kriiss discovers about one-tenth of 1 per 

 cent, of germaniuui oxide. (Berichte, xxi, 131.) 



Hydrazin. — The compound N2U4, hydrnzin or amidogen, of which 

 many derivatives have long been known, has at last been isolated by 

 Curtius. When diazoacetic ether is treated with hot, strong ])otash lye 

 the potassium salt of a new acid is formed. When this salt is treated 

 with a mineral acid the new diazo aciid is set free, which uj)on digestion 

 with dilute sulphuric acid deposits superb colorless crystals of hydrazin 

 sulphate. The latter by warming with caustic alkali solutions readily 

 vields up free hydrazin as a colorless, ])erfectly stable gas having a pe- 

 culiar odor slightly suggestive of ammonia. It dissolves easily in water 

 to a strongly alkaline solution, which acts as a powerful reducing agent, 

 precipitates alumina and other like bases from their salts, and unites 

 readily with acids. (Berichte, xx, 1G32.) 



The chloride of nitrogen. — This compound, which is perhaps the most 

 violent exi)losive known, has been recently investigated by Gattermau. 

 As obtained by the action of chlorine upon sal ammoniac sohition, it 

 was found to be indefinite in composition and to contain vaiious admix- 

 tures of chloramines. From tiiis mixture the pure NCI.! was ])re|)ared 

 by first washing thoroughly with water in a separatory funnel and then 

 saturating for half an hour with a stream of chlorine. The oil so ob- 

 tained was thoroughly washed, dried, and analyzed and, was found to be 

 definite in composition. By careful manipulation it was prepared about 

 thirty times without explosion, and its re))utedly ca])ri(uous explosibility 

 was found to be due to the action of light. By ilasliing u])on it the light 

 from burning magnesium it exploded violently. On careful heating up 

 to 90° it remains unchanged, but exploded with great force when the 

 temperature reached Oo^. (Beiichte, xxi, 751.) 



In a note upon the foregoing pajier Mallet calls attention to the fact 

 that nitrogen iodide, which is not seiisitive when wet, when dry also 

 detonates by exposure to bright sunlight. (Chem. News, lviii, (U.) 



Thiophosphoryl fluoride. — According to Thorpe and Rodger, when 

 phos])horus ])entasul])hi(le is heated with lead fluoride in a leaden tube 

 a gas is formed which analysis shows to be thiopliosi)horyl fluoride, 

 PSF3. It is also produced by several other re-actions, and is a trans- 

 parent, colorless, liquefiable gas. In contact with air it spontaneously 

 ignites, burning at a jet with a pale yellowish green flame tip])ed with 

 blue. It dissolves in water, to some extent in ether, not at all in alco- 

 hol or benzene. It has no action on mercury. (Jour. Chem. Soc, Liii, 

 766.) 



