Chemistry and Physics. 151 



tubes may be combined into one system and worked with alter- 

 nating- currents; though for single tubes a continuous current 

 with an interrupter is best. The apparatus now at work in the 

 above laboratory yields 2 - 4 milligrams of ozone per second. 

 Experiments are in progress looking to the production of a sup- 

 ply of compressed ozone for technical uses; this having already 

 been done on the small scale under a pressure of nine atmospheres. 

 One use specially dwelt upon by the lecturer is that for the disin- 

 fection and sterilization of water. — Nature, xlv, 39, November, 

 1891. G. F. B. 



4. On Free Hydroxylamine. — Free hydroxylamine NH 2 0H, 

 has at last been isolated by Lobry deBeutst. For this purpose 

 he heated about a hundred grams of hydroxylamine hydrochlorate 

 dissolved in 600 co of warm methyl alcohol, with such a quantity 

 of sodium, also dissolved in methyl alcohol, as was necessary to 

 leave the hydrochlorate in slight excess. After removing the 

 sodium chloride by decantation and the methyl alcohol by dis- 

 tillation at 160-200 mm pressure, the residue was treated with 

 anhydrous ether to completely precipitate the last traces of the 

 sodium chloride. The liquid separated into two layers, the upper 

 one being the ether, containing about 5 per cent of hydroxylamine, 

 and the lower containing over 50 per cent, besides the remainder 

 of the methyl alcohol. On subjecting this lower layer to fraction- 

 ation under 60 mm pressure, three products were obtained, one 

 containing 27 per cent of hydroxylamine, one 60 per cent, and 

 the third crystallizing in the ice cold receiver in long needles and 

 being pure hydroxylamine, NH 2 OH. It is very hygroscopic and 

 fuses at 33°, the liquid having a remarkable power of dissolving 

 metallic salts. It is without odor and is heavier than water. It 

 explodes violently when heated to 80-100°. It is only slightly 

 soluble in liquid carbon compounds such as chloroform, benzene, 

 carbon disulphide and the like. It readily attacks cork and 

 cellulose. The pure crystals are very stable. Bromine and 

 iodine act upon free hydroxylamine, the former with violence. — 

 Recueil des travaux chimiques des Pays Bas, x, 101, 1891; 

 Nature, xlv, 20, November, 1891. g. f. b. 



5. On Iron Carbonyls. — Mond and Langer have continued 

 their researches upon the volatile compound of iron and carbo- 

 nyl discovered by them in the first half of the present year.* 

 For its preparation, they now prepare first finely divided iron by 

 heating ferrous oxalate in a current of hydrogen, boiling the 

 resulting product in water, and again heating the iron in a cur- 

 rent of hydrogen. The hydrogen after cooling is displaced by 

 carbon monoxide and the tube is closed at one end the other be- 

 ing connected to the source of supply of the carbonyl, this gas 

 being slowly absorbed by the iron. After twenty-four hours, the 

 irou-carbonyl is distilled off, the receiving tube being cooled to 

 — 20°, and the operation is repeated. The yield is small, only 

 one gram being obtained from 100 grams of iron. As thus ob- 



* See this Journal, III, xlii, 424, November, 1891. 



