CHEMISTRY. 309 



formula 2 (FeO, W0» ) + 3 (MnO, WO 2 ). The second exhibits a blackish-brown 

 streak, with stronger metallic lustre, and G — 7.8 — *7.5. Its formula shews : 

 4 (FeO, WOs) + MnO, WO 3 . Our specimen; is of the first kind. Breithaupt's 

 angles for oo : cx> and oo '• ob , differ considerably from both those of Gustav 

 Rose and Kerndt ; and the measurements given above tend to confirm these 

 variations. Descloizeaux also, it must be remembered, obtained still other results, in- 

 dicating seemingly a monoclinic crystallization. I he character of the twin-crystals 

 of Wolfram, however, (as pointedout bi Naumann) and its relations to Tantalito 

 (see Dana's Min.4th edit, ii, 351, for angles), are opposed to this latter view. 



Our specimen exhibits the following blowpipe reactions : — Per se, it fuses easily, 

 and without intumescence or bubbling, into a dull iron-grey globule, the surface of 

 which is scoriaceous rather than crystalline. The globule is not attractable by the 

 magnet. 



It dissolves readily in borax, producing before the OF a dark amethystine 

 glass. Quickly cooled, after exposure to the R F, the glass is yellow. With a 

 sufficient quantity of the assay, the surface of the bead may be enamelled (or ren- 

 dered milk-white) by the flaming process. 



It dissolves also readily in salt of phosphorus. A very small quantity renders 

 the bead opaque, but no effect is produced by flaming. 



With carbonate of soda, effervescence takes place, but a very small portion of 

 the assay dissolves, so that no striking manganese reaction is produced. If, how- 

 ever, a minute quantity of borax be added, the greenish-blue enamel is at once ob- 

 tained. On cooling, the fused mass shoots into crystals. 



E. J. C. 



CHEMISTRY. 



NITRIC ACID. 



Cavendish proved that nitrogen can be made to unite directly with oxygen by 

 means of the electric spark, if the two gases be moist, and especially if an alkali be 

 present, when a nitrate is formed. In other words, ozone (modified oxygen) is 

 capable of uniting with nitrogen to form nitric acid. Honzeau shewed that nascent 

 oxygen, from peroxide of barium and sulphuric acid, is capable of oxidizing 

 ammonia, and of separating chlorine and iodine from its combinations behaving 

 exactly like ozone. Cloez has shown that the oxygen and nitrogen of the air can 

 be made to combine by the influence of porous bodies. 



S. de Luca has obtained nitrate of potassa by passing moist ozonized air over 

 potassium or potassa for several months. It appeared from some experiments, 

 which require confirmation, that this change takes place more readily during the 

 winter and at night than in summer and in the day time. 



PHOSPHORUS. 



E. Mitscherlich recommends the following process for the detection of phosphorus 

 in cases of poisoning. The substance to be tested is mixed with sulphuric acid 

 and water and distilled, the vapours are passed through a gas tube into a vertical 

 cooling tube which is kept cold by passing through a vessel of water. If phos- 

 phorus be present, its vapours pass over with the water and produce a luminous 



* These calculated angles was be of use to the Btudent in the determination of oroken or 

 ■complete crystals. They are nol given in any work -English, French, or Gorman- within 

 the writer's knowledge— E. J. C- 



