Boron and Silicon with Nitrogen. 275 



to contain oxygen, than the " boronitruret of potassium." 

 Cyanide of mercury heated with boracic acid gave cyanogen 

 abundantly, which burned with a tinge of green in its flame ; 

 and at the same time a small quantity of white crystalline 

 solid sublimed, which may prove to be a compound of mer- 

 cury with the M boride of nitrogen," and being such, if it could 

 be obtained in larger quantity, might probably be a means of 

 isolating the much-wished for " boride of nitrogen." It was 

 soluble in water, giving it a bitter taste ; and the solution gave 

 no precipitate with a salt of iron, but an abundant white with 

 protochloride of tin : with iodide of potassium none, with 

 acetate of lead none, with nitrate of silver a slight precipitate, 

 which was insoluble in excess of acid. It was likewise soluble 

 in alcohol, but the solution did not burn with a green flame. 

 Boiled with a solution of carbonate of potass it yielded am- 

 monia, and it communicated a green colour to flame, passing 

 off rapidly in vapour, and giving a greenish blue colour to the 

 flame in its immediate neighbourhood. 



A mixture of one part of anhydrous boracic acid with two 

 and a half parts of cyanide of zinc, heated to whiteness in a 

 lined crucible (covered and well luted), yielded a white solid 

 similar in appearance to that obtained by heating a mixture of 

 boracic acid and cyanide of potassium. It gave ammonia abun- 

 dantly when heated with a mixture of hydrate of lime and car- 

 bonate of potass, and was insoluble (with and without heat) in 

 water, sulphuric acid, hydrochloric acid, nitric acid, solution of 

 chlorine, solution of potass and ammonia. It is not decomposed 

 by chlorine at ajicll red heat, nor by corrosive sublimate, nor 

 by potassium or sodium. Before the blowpipe it is infusible, 

 but in the oxidizing flame communicates a green colour, and 

 when at the outer edge emits a very brilliant bluish phos- 

 phorescence, which appearance it also produces when simply 

 dropped into the flame of a spirit-lamp. Thrown on fused 

 chlorate of potass it deflagrates with a faint blue light. These 

 characters are exactly such as we should expect to find in a 

 compound of zinc with " boride of nitrogen " analogous to the 

 compound of potassium. It appeared to be in a state of 

 purity, and is more readily obtained than the potassium com- 

 pound, since the preparation of a pure cyanide of zinc is ac- 

 complished with greater facility than that of cyanide of potas- 

 sium. Besides its interest in being distinctly a second com- 

 pound of the kind, and the remarkable beauty of its phospho- 

 rescence before the blowpipe, it is of importance as affording 

 a means of preparing the analogous compound of other metals 

 by heating it with their chlorides. Heated to whiteness in a 

 lined crucible in the proportion of one atom of itself (taking 



T2 



