112 Scientific Intelligence. 



13. Phosphate and Pyrophosphate of Lime; by W. Baer, (Poggen- 

 dorfFs Ann. in Chem. Gaz.) — The ordinary phosphate is obtained crys- 

 tallized by solution of phosphate of soda made strong by acid with 

 acetic acid; precipitated with chlorid of calcium, it is P0 5 2CaO, HO-j- 

 4HO. A part of the water is expelled at 302°, but the remainder only 



at a red heat. 



Pyrophosphate of soda with acetic acid precipitated with excess of 

 chlorid of calcium, gives a crystalline pyrophosphate of lime P0 5 

 2CaO-f-4HO. The preceding salt prepared with excess of pyrophos- 

 phate of soda always contains soda, and by prolonged digestion, a well 

 defined double salt is obtained which is P0 5 CaO, NaO-f-4H#. 



G. C. S. 



14. Process of extracting Nickel and Cobalt followed in a Manu- 

 factory at Birmingham ; by M. Louyet, (Chem. Gazette, April 16, 



1849, p. 165; from Bullet, de TAcad. Royale de Belgique.) — The ore 

 employed in this manufactory is obtained from Hungary. It consists 

 principally of metallic sulphoarseniurets, and contains generally 6 per 

 cent, of nickel and 3 per cent, of cobalt. These proportions how- 

 ever vary. 



The ore is mixed with a small quantity of carbonate of lime and 

 fluor spar, and the whole heated to a white-red in a reverberatory fur- 

 nace ; the mass fuses at this high temperature, and a slag is obtained 

 floating on the surface, which is removed, and a fluid mass of metallic 

 appearance ; the latter is let out of the furnace by a particular aper- 

 ture, and watered in order that it may be broken into fragments with 

 greater facility. It has been ascertained from experience that when 

 the slag is of a dull color, it contains iron ; but if its surface is black 

 and brilliant, it is free from it. The metallic mass is reduced to a very 

 fine powder, which is then calcined at a bright red in a furnace, grad- 

 uating the temperature so as to avoid fusion, and constantly raking it ! 

 a considerable quantity of arsenious acid is driven off. The air has 

 free access to the mass, which becomes oxydized and diminishd in 

 weight. The calcination, which lasts (or about twelve hours, is con- 

 tinued until no more white fumes are given off, and the residue is treated 

 with hydrochloric acid, which dissolves nearly the whole of it ; the 

 liquid is diluted with water, and milk of lime and hypochlorite of lime 

 (chlorid of lime) added,* when a precipitate falls, which after being 

 well washed is thrown away. A current of washed sulphureted hydro- 

 den, generated from sulphuret of iron and dilute sulphuric acid, is 

 passed into the liquid until it is saturated ; it is discontinued when some 

 ammonia, added to a sample of filtered liquid, gives a black precipitate ; 

 if there was not an excess of sulphureted hydrogen, the precipitate 

 produced by ammonia would be green. The sulphureted hydrogen 

 causes a precipitate in the liquid ; it is washed, and as it is slightly 

 soluble, a current of sulphureted hydrogen is passed into the wash- 

 waters. The precipitate is thrown away. The cobalt is then thrown 

 down with a solution of hypochlorite of lime. The precipitate, washed, 



The lime and hypoehlorit 

 c ; the hypochlorite, by per< 

 lime. 



