544f Intelligence a7id Miscellaneous Ar fides. 



Most English mineralogists give a right rectangular prism for the 

 primary form of the bournonite ; but Dufrenoy, in his recent Treatise, 

 vol. iii. p. 18, after an examination of numerous crystals, considers 

 a right rhombic prism in which the angle MM = 93" 40' to be the 

 correct primary form. The modified rectangular prism in which 

 the bournonite usually occurs is in this light a secondary form, de« 

 rived from the primary by the replacement of its lateral edges by 

 the planes g' h' in the notation of Hauy. 



The specimen of the needle ore which furnished the above ana- 

 lysis, exhibited here and there in the quartz transverse rhombic 

 sections, in which an accustomed eye might easily perceive that the 

 obtuse angle was included between 90° and 100°. 



I could not detect in this specimen the presence of tellurium, 

 found by John in the needle ore ; it is however perfectly conceivable 

 that, under certain circumstances, a portion of the PbS may be re- 

 placed by PbTe. — From the Chemical Gazette for September 1, 1847. 



ACTION OF ANHYDROUS PHOSPHORIC ACID ON AMMONIACAL 

 SALTS. BY M. DUMAS. 



The author finds that when anhydrous phosphoric acid is made to 

 react upon crystallized acetate of ammonia, there distils a liquid the 

 fixed boiling-point of which is 170° F., and which is miscible with 

 water in all proportions. When purified by digestion with a saturated 

 solution of chloride of calcium, and then distilled from solid chloride 

 of calcium and from magnesia, it still possesses the boiling-point 

 above mentioned. 



Analysis gave the following numbers : — 



Experiment. Calculation. 



Carbon 57*4 58-5 



Hydrogen 7"4 7'3 



Nitrogen 34*4 34-2 



99-2 100-0 



The density of the vapour gave the number 1*45. The above 

 results lead to the very simple formula C"* H^ N, which differs from 

 acetate of ammonia by four equivalents less of water. Its composi- 

 tion is similar to that of nitroguret of acetyle. 



But a point of view, which the reactions will warrant, would give 

 to this substance the following rational formula. C^ NH, C- H^, which 

 would make hydrocyanate of methylene of it, or an isomeric of it. 



The reactions w^hich have been examined gave rise to some curious 

 phaenomena. Thus solution of potash at a boiling heat disengages 

 ammonia and regenerates acetic acid ; chromic acid has no action ; 

 nitric acid is not decomposed by this liquid even when heated to 

 ebullition. Potassium acts vividly in the cold, and with the disen- 

 gagement of heat ; cyanide of potassium is formed, and an inflam- 

 mable mixture of free and carburetted hydrogen gases is evolved. 



It is well known that M. Fehling obtained a substance of analo- 

 gous composition to that now described by distilling benzoate of 

 ammonia with a naked fire : he did not however attach to the dis- 

 covery the views which have been now developed, nor did he study 



