Physics and Chemistry. 469 



counter-pressure, velocities of 6000 meters per second were 

 observed; necessitating; it would seem, a revision of the theory. 

 — Ann. Chim. Phys., VI, vii, 289-349, March, 1886. g. r. b. 



2. On the Existence of Nitryl Chloride. — Williams has ex- 

 amined experimentally the common statement of the text-books 

 that nitryl chloride not only exists but is readily prepared ; 

 making use of such reactions as seemed likely to afford this 

 compound. In the first, phosphorus oxychloride was allowed to 

 drop from a tap funnel upon pure dry lead nitrate contained 

 in a flask connected with a condenser. But only a few drops of 

 a yellowish red liquid were obtained ; the gas which escaped 

 continually, having the properties of chlorine, while reddish 

 vapors appeared in the flask. Then in the same apparatus, pure 

 nitric acid was allowed to drop on the phosphorus oxychloride 

 contained in the flask. More distillate was now obtained but the 

 oxychloride was also always present. On treating nitric acid 

 and phosphorus oxychloride in equivalent proportions in sealed 

 tubes for two hours at 100°, two layers appeared, the upper deep 

 red and mobile, the lower yellow and viscid, most probably 

 phosphoric acid. On opening the tubes, chlorine and hydro- 

 chloric acid gases escaped. Dry fused potassium nitrate was 

 then placed in a test tube and sulphuric chlorhydrin was poured 

 upon it. Heat was evolved and chlorine and nitrogen tetroxide 

 were given off in large quantity. On passing the vapors through 

 a condenser cooled to — 18°, a small quantity of a deep red liquid 

 was obtained which proved to be a solution of chlorine in 

 nitrogen tetroxide. Sulphuryl clichloride was then sealed up 

 with an equivalent quantity of potassium nitrate and heated to 

 100° for several hours. A certain amount of red gas was formed 

 and on opening the tube chlorine was .collected over hot water. 

 Hence the author infers that in general whenever a nitrate is 

 acted upon by an acid chloride, nitryl chloride is not obtained as 

 such but only its constituents, nitrogen tetroxide and chlorine. 

 Three series of experiments were made to form nitryl chloride by 

 direct synthesis. In the first, the chlorine and nitrogen peroxide 

 were passed through a red hot tube, as Hasenbach suggested. 

 But since the tetroxide decomposes at a red heat into the dioxide 

 and oxygen, it was probable that the product would be nitrosyl 

 chloride ; and this was found to be the fact, as was proved by 

 analysis. In the second and third the mixture was passed 

 through a large U tube, filled with broken glass and heated to 

 130°-150°. The product-was a red volatile liquid, whose ob- 

 served vapor density agreed best with that calculated on the 

 hypothesis that all the chlorine was free. In the third series, 

 however, the distillation was continued for a short time only and 

 the accordance was closer. The author concludes therefore, that 

 nitryl chloride cannot be formed by direct synthesis ; the pro- 

 duct, like that obtained by the other methods, beiug merely a 

 solution of chlorine in nitrogen peroxide. — J. Chan. Soc, xlix, 

 222-233, April, 1886. G. F. b. 



