430 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Properties of free Hydroxylamine. — A further 

 paper on the properties of hydroxylamine has been published by 

 Lobrt de Beuyx. In the solid state it forms white inodorous 

 scales or hard needles which melt at about 33-05° and remain in 

 the surfused state on cooling, even at 0°. At 58° and under a 

 pressure of 23 mm , it boils; and when heated to 90°-100° it 

 decomposes evolving gas. At a higher temperature it detonates. 

 The crystals have a density of 1*35 as determined by the method 

 of suspension in a mixture of chloroform and benzene ; while in 

 the liquid state the density is 1*23. According to Eykmann the 

 refractive index at 14° for sodium light is 1 '44123 and at 40° 

 1*43359. Its molecular mass by Raoult's method is 33. The 

 crystals liquefy on exposure to air, increase in weight and vola- 

 tilize completely. In a current of dry chlorine, hydroxylamine 

 inflames; but bromine and iodine decompose it without flame. 

 In the solid state it is oxidized on exposure to the air; a white 

 substance is formed containing nitrous acid and ammonia. When 

 dry oxygen is passed through the fused hydroxylamine white 

 fumes of nitrous acid are produced with but little evolution of 

 heat. Sodium attacks it with the production of flame. When 

 added to its solution in dry ether, hydrogen is evolved, and a 

 voluminous white amorphous substance is formed probably a 

 compound of hydroxylamine with sodium hydroxylaminate. 

 Crystals of potassium permanganate, of chromic acid, of potassium 

 and sodium chromates and of ammonium dichromate produce 

 decomposition with a white flame; while potassium and sodium 

 dichromates cause a sharp violent explosion. With certain 

 chlorides, hydroxylamine forms compounds analogous to their 

 hydrated salt. The most probable formula the author thinks is 

 NH 2 .OH. — Bee. Trav. Ghim., xi, 18; J. Chem. Soc., lxii, 1391, 

 Dec. 1892. g. f. b. 



2. On the Trisulphide and the Pentasidphide of Boron. — 

 According to Moissan boron trisulphide may be formed (1) by 

 acting on boron iodide with melted sulphur, (2) by acting on 

 amorphous boron with the vapor of sulphur, (3) by the action of 

 hydrogen sulphide on pure boron at a bright red heat, (4) by the 

 action of pure carbon disulphide vapor on boron at a red heat, 

 and (5) by the action of tin, antimony or arsenic sulphide on 

 amorphous boron at a red heat. When condensed in a large 

 receiver, boron trisulphide forms white slender needles which are 

 very unstable and are decomposed by water with the evolution 

 of hydrogen sulphide and without separation of sulphur. The 

 crystals begin to melt at 310° and pass through a pasty condition. 

 Their density is about 1*55. It is slightly soluble in phosphorus 

 trichloride, from which it crystallizes in slender colorless needles. 



