io6 



NA TURE 



[November 30, 1893 



account of the explosive character of hydroxylamine, it 

 is dangerous to employ even a small naked flame, which 

 is liable to effect local superheating. The temperature 

 of explosive decomposition lies in the neighbourhood of 

 130" ; by uninterrupted distillation in the manner indi- 

 cated, and at a pressure not exceeding 22 m.m., the 

 hydroxylamine passes over entirely at a temperature of 

 56-57'', and by maintaining the water bath at only a few 

 degrees superior to this temperature all danger of ex- 

 plosion is avoided. The methyl alcohol is practically 

 entirely removed by the pump. Instead of leading the 

 distillate through a warmed condenser, as recommended 

 by M. de Bruyn, a practice which materially diminishes 

 the yield by decomposition of a portion of the product, 

 Prof. Briihl finds it much more advantageous to feed the 

 condenser with a constant supply of iced water ; for 

 although the melting point of hydroxylamine is 33°, it 

 does not resolidify even at temperatures only a few 

 degrees above zero, so that stoppage of the condensing 

 tube does not occur. It solidifies instantly, however, in 

 contact with a vessel immersed in ice and salt. The 

 cylinder containing the receivers is therefore immersed 

 in such a mixture, so that each drop of hydroxylamine 

 solidifies the moment it enters the receiver. The 

 hydroxylamine thus obtained in one operation is sub- 

 stantially pure. From thirty grams of the hydrochloride 

 about ten grams of the base may be obtained in one 

 hour, a yield of 66 per cent, of the theoretical, which is 

 four times that obtained by the method of M. de Bruyn. 

 In the case of hydroxylamine becoming a commercial 

 preparation, on account of its extraordinarily great anti- 

 septic power, it would be quite easy, by introducing 

 suitable additional condensers, to recover the whole of 

 the methyl alcohol employed. 



The pure white crystalline hydroxylamine melts accord- 

 ing to the mode of heating and the size of the containing 

 tube at 32-34°, and its boiling point for a pressure of 

 22 m.m. is 56-57°. It may actually be cooled below 0° 

 without solidifying, if allowed to remain at rest ; but, like 

 most other substances which exhibit the property of 

 superfusion, it solidifies the moment it is agitated. In 

 the solid state it does not appear to be liable to decom- 

 position. Even in the liquid state at 0° indications of 

 decomposition have not been observed. At 10°, however, 

 bubbles commenced to form in the liquid, and at 20" a 

 continuous evolution of gas, mainly nitrogen, occurs, be- 

 coming more and more violent as the temperature rises, 

 until sudden explosion takes place. Hence in a warm 

 summer hydroxlamine cannot be preserved in sealed glass 

 tubes. Thus a specimen, after keeping for eight days in 

 July, was found to be no longer capable of solidification 

 even at -6°, although there was sufficient of the base left 

 undecomposed to explode with a certain amount of 

 violence upon heating, less, however, than in the case of 

 freshly-prepared hydroxylamine. When just prepared 

 one drop warmed in a test tube over a flame explodes 

 with a report equal to that of a gun-shot. It is suggested 

 that hydroxylamine might be safely preserved in metaUic 

 vessels, for it appears likely that the notable action of 

 the liquid upon glass causes the commencement of the 

 decomposition. 



At the temperature of 23"5° the relative density of pure 

 liquid hydroxylamine is 1-2044. Its refractive index at 

 the same temperature varies from r4375 for light of the 

 wave-length of the red lithium line to i^SU for light 

 corresponding to the blue hydrogen line Hy. The sub- 

 stance thus exhibits a small refractive power and a sur- 

 prisingly small dispersion. Indeed, its molecular 

 dispersion is about the same as was found by Prof. 

 Briihl for nitrogen itself in triethylamine, so that the 

 atom of oxygen and the three atoms of hydrogen would 

 appear to exert no dispersive action if the same value for 

 nitrogen be assumed to be equally operative. The only 

 possible explanation is that the nitrogen here united to 

 NO. 1257, VOL. 49] 



oxygen and hydrogen possesses a lower spectrometric 

 constant than when attached to carbon in triethyla- 

 mine. From a systematic study of the spectrometric 

 constants of the free base, and of the methyl derivative 

 CH3NH.OH prepared by his assistant Dr. Kjellin, an 

 account of which was given in the Notes of Nature 

 of November 9, Prof. Briihl has been enabled to 

 prove two important facts. The first is that the con- 

 stitution of hydroxylamine can be none other than 



^\ 



^N - O - H. The second is that the molecular refrac- 



W 



tion and dispersion of the nitrogen present in these com- 

 pounds is the same as that of the nitrogen in ammonia 

 gas, much lower than that of the nitrogen in triethylamine, 

 and that the probable values of these constants of nitrogen 

 linked in this manner, for sodium light, are respectively 

 2"495 3.nd 0*072. This addition to our knowledge of 

 the spectrometric constants of nitrogen will be of invalu- 

 able aid in unravelling the intricate subject of the consti- 

 tution of the class of nitrogenous organic substances 

 known as " oxims," a subject upon which Prof. Briihl 

 is now concentrating his attention. A. E. Tutton. 



NOTES. 



It is with much regret that we announce the death of Baron 

 von Billow, at Kiel. Von Billow's Observatory, better known, 

 perhaps, as Bothkamp Observatory, was the first in Germany 

 devoted to astro-physical researches, and it stands as a splendid 

 monument to his interest in astronomy. By his death astro- 

 nomical physics has lost one of its most enthusiastic sup- 

 porters. 



The meeting of the Vienna Academy of Sciences was ad- 

 journed on November 16, as an expression of regard for Dr. 

 Alexander von Bach, who died on November 12. 



The memorial to Sir Richard Owen is to take the form of a 

 full-length marble statue, executed by Mr. Thomas Brock, and 

 placed in the Natural History Museum, South Kensington. 



A BOTANICAL section has been added to the Zoological 

 Station at Naples, with a small laboratory for algological studies 

 and researches in vegetable physiology. 



Dr. Oswald Kruch has been appointed to the Conservator- 

 ship of the Royal Botanical Institute of Rome, recently resigned 

 by Dr. A. Terracciano. 



A Reuter's telegram from Montreal announces that the 

 worst earthquake ever experienced in Canada occurred there at 

 noon on November.27. As far as has been ascertained, no lives 

 were lost, but considerable damage has been done to property, 

 and the walls of many buildings have been cracked. 



A SEVERE earthquake was felt at Peshawur, and other places 

 in the Punjab, about nine o'clock on the morning of November 5, 

 but fortunately no very serious damage was done. The wave 

 apparently extended over a large area, including the Tamrud 

 plain and Nowshera. 



An international Photographic Exhibition will take place at 

 Milan from May until October next year. There will be a sec- 

 tion for professional photography, another for amateur photo- 

 graphy, and a third for technical and industrial applications of 

 photography. 



The Department of Science and Art has received, through 

 the Foreign Office, a dispatch from her Majesty's Minister in 

 Chili calling attention to an exhibition which it is proposed to 

 hold next year at Santiago, dealing with the subjects of mining 

 and metallurgy. The exhibition will be opened in the second 



