176 Miscellaneous Intelligence. 



is given, as one recommended by MM. Vauquelin and Thenard, 

 for the detection of phosphate of lime, founded upon its conversion 

 by potassium into a phosphuret, and the production of phosphuret- 

 ted hydrogen, either with water or acids, by the latter body. The 

 gas is recognised by its well-known odour, and indicates the pre- 

 sence of a phosphate in the matter originally used. The decompo- 

 sition is to be effected in a glass tube, 3 or 4 millimetres (0.15 inch) 

 in diameter, and about 4 centimetres (1.5 inches) long ; a centi- 

 gramme (0.15 grain) of potassium is to be placed at the bottom, and 

 the substance supposed to contain the phosphate in powder is to 

 be pressed down upon it. The tube is then to be gradually heated, 

 the potassium sublimed through the substance, and, when cold, 

 the excess of potassium removed by the introduction of mercury. 

 The matter remaining, when exposed to a moist air, or when 

 touched by muriatic acid, will evolve the odour of phosphuretted 

 hydrogen, if any phosphate were present ; or a little diluted acid 

 may be introduced into the tube, and the gas evolved obtained. 

 Of course, any sulphate which may be present must be removed, or 

 the odour of sulphuretted hydrogen would seriously interfere with 

 the delicacy of the test. — Jour, de Chim. Med. Jan. 1825. 



8. Metallic Titanium in Iron Furnaces. — Cubic crystals of me- 

 tallic titanium, similar to those discovered by Dr. Wollaston in 

 the iron-furnaces of South Wales, have also been found by Dr. 

 Walchner, of Friburg, in the Breisgau, in the founderies of the 

 highlands of Baden. The piece of slag examined was from the 

 high furnace of Kandern, in which pea-iron ore only is smelted. 

 Being desirous of ascertaining the presence of the titanium in the 

 pea-iron ore, an attempt was made with the blow-pipe, and its 

 presence, Dr. Walchner says, indicated, though in very small 

 quantity. — Phil. Mag. lxvi. 124. 



9. Rose on the Separation of Titanic Acid from Oxide of Iron. — 

 The difficulty of separating titanic acid from oxide of iron, is well 

 known to chemists, no process but what is very imperfect being 

 as yet known. M. Rose, who has had frequent occasion to com- 

 bat this difficulty, has discovered and published a method which 

 not only renders analytical processes more perfect, but very much 

 facilitates the preparation of titanic acid from its more abundant 

 natural compounds. 



A solution of titanic acid and oxide of iron being obtained in 

 muriatic acid, if tartaric acid be added to it, and the whole be 

 diluted with water, then a great excess of caustic ammonia may 

 be added without the smallest precipitate of titanic acid or oxide 

 of iron being produced. If to this solution hydrosulphuret of am- 

 monia be added, it exerts no action on the titanic acid, but changes 

 all the oxide of iron into sulphuret, which separates perfectly. 



