462 Scientific Intelligence. 



of hydrogen iodide, but may be preserved in an atmosphere of 

 chlorine. Iodine trichloride fuses at 32° C, is volatilized at 47-5° 

 (though it gives off vapor even at —12°) and is dissociated at 

 72° into monochloride and chlorine. It is soluble in cold water 

 without decomposition. — Ber. Berl. Ghem'. Ges., x, 434, March, 

 1877. G. F. B. 



2. On the Atomic Weight of Selenium. — Pettekson and 

 Eh : ■ s have redetermined the atomic weight of selenium by sev- 

 eral methods, using for analysis calcium selenate, ammonio-alumi- 

 num selenate (an alum) magnesium and silver selenites and silver 

 selenate. The numbers obtained not being sufficiently accordant 

 they tried reducing selenous oxide by means of sulphuric acid 

 and determining the selenium precipitated. In five experiments 

 they deduced the atomic weiirhl ■' s. 1, i ium as 79-10, 79-06, 79-08, 

 79-06, 79-08, the mean of which is 79*08, which may be accepted 

 as the true atomic weight of this metalloid. — Bull. ISoc. (7Aem.,H, 



3. On Trihydroxylantimonic acid and * I 



Analogy points out the existence of an antimonic acid 0=Sb— OH 



and an antimonyl chloride SbOCl 3 , corresponding respectively to 



0=P— OH and to POOL. Daubrawa has studied the question 

 ^OH 



of lie antimonic acids anew, using Berzelius's method for prepar- 

 ing them, i. e., by dropping antimonic chloride into water. The 

 results of analysis showed that the air-dried precipitate was 

 H 8 Sb 2 9 ; dried over 3 a i I Sl.i >, ; at 100° C, 



it became H^O, ; at 200°,HSbO 3 ; at 275°,Sb 2 5 ; and above 

 300°, Sb„0 4 . For the preparation of the oxychloride, one part by 

 weight of wat- r was ■':>' >\ p. d into sixteen parts by weL 

 timonic chloride. A Inctly crystalline mass 



resulted, whicli was delhjuesrem in the air, and which fused, boiled 

 sed in a closed tube, dissociating into SbOCl and Cl 2 at 

 higher temperatures. The ae. alt, gave the 



formula SbOCl Z .—Liebig's Ann., clxxxvi, 110, March, 1877. 



4. On the Constitution of Cyanamide.—Oi the two rational 

 formulas assigned to cyanamide, NeeC-NH 2 and C^g, the 



3 of di-sil 



! probable 



hmvev< ■■ th I xh\> n 1. tormula is actually not the true one. 

 By acting oi with ethyl iodide, di-ethylcyan- 



D properties and in decomposition 

 i' : ' 



zaro and Cahours from cyanogen chloride and diet' 

 As in this latter body the two ethyls are united to the same 



