10 



AKCON, A NEW CONSTITUENT OF THE ATMOSI'MEKE. 



(I)) NItriile of .silicon^ i\\>^o i'e(|uiifs fur its foiination a wliite heat, ami o(Hii- 

 {tlete union is ditticult to bring about. Moreover it is not easy to obtain large 

 (quantities of silicon. This method was therefore not attempted. 



(c) Nitride of titanium is said t(^ have been foinied by Deville and Caron,^ by 

 heating titanium to whiteness in a curienr of nitrogen. This process was not tried 

 by us. As titanium has an unusual tendency to unite with nitrogen, it niight, 

 perhaps, be worth while to set the element free in presence of atmos[)heric nitro- 

 gen, with a view to the absorption of the nitrogen. This has, in effect, been 

 already done by AVohlei- and Deville''; they passed a mi.\ture of the vapor of 

 titanium chloride and nitrogen ovei- i-ed-hot aluminum, and obtained a laige yield 

 of nitride. It is possible that a mixtuie of the precipitated oxide of titanium with 

 magnesium dust niight be an effective absorbing agent at a comparatively low 

 temperature. 



(d), (e) Lithium at a dull-red heat absorbs nitrogen,^ but the difficulty of 

 obtaining the metal in (piautity piecludes its application. On the other hand, 

 strontium and harium, prepared by electrolyzing solutions of theii' chlorides in 

 contact with mercury, and subsequently i-emoving the mercury bv distillation, are 

 said by Marpienne^o absorb nitrogen with readiness. Although we have not 

 tried these metals for removing niti'ogen, still our experience with their amalgams 

 has led us to doubt their efficacy, for it is extremely difficult to fi'ee them from 

 niei'cury by distillation, and the product is a fused ingot, exposing very little sur- 

 face to the action of the gas. The pi'ocess might, howevei", be worth a trial. Nitro- 

 gen is also known to be converted into cyanides when passed over a mixture of 

 Ijaryta and carbon, and this may ])ossibly prove to be the most efficient method of 

 effecting its removal on a large scale. 



(f) Nitride of magnesium was prepared by r)e\ille and Caron (loc. cit.) 

 during the distillation of impure magnesium. It has been more carefully investi- 

 gated by Briegleb and Geuthei," wlio ulitained it by igniting metallic magnesium 

 in a current of nitrogen. It forms an orange-brown, friable sulwtauce, very porous, 

 and it is easily produced at a bright-red heat. When mafrnesiuni, preferably in 

 the form of thin tui-nings, is heated in a conibustion tube in a cuiient of niti'ogeii, 

 the tube is attacked superficially, foi ining a coating of magnesium silicide. As the 

 temperature lises to bright redness, the magnesium begins to glow brighth', and 

 combustion takes place, beginning at that end of the tube through which the gas 

 is introduced. Hie comliustion proceeds regulai'ly, the glow extending down the 



' Schiitzenljerger, Comptes Reiufus, 89, 644. ' Oiivrard,.C<>/////« Rcndiis, 114, 120. 



' Aiiiialen der C/icmie itnJ P/iarrnacie, loi, 360. ' Ibid., 1 14, 25 and 220. 



' //i/'(/., 73, 34. ' Annalen dcr Chcmic und Phannxcie, 123, 228 



