SODA AND SODA COMPOl 



C'J'J 



be, result. TIio silicate is directly useful for 



gloss-milk! rith.r of the salts nam.-d 



with mil-tic lime, sotting free 



soda, which can then be carbonated. 



vol. xvii., 18C3. 



is rtated to have been devised by 

 Mr. \Wldon (Kii^laml), tor the almost immcdi- 

 ate production of hicarbonato of soda, by 

 pumping into strong reweli containing eqniv- 

 and common salt, tho air 

 passing through a coal tire, and charged of 

 course with car! ionic acid, chloride of magne- 

 sium and bicarbonate of soda resulting. 



ni Cryolite. The interesting min- 

 eral, cryolite, found as yet in but few parts of 



trth, and most largely perhaps in Green- 

 land, is, as pn.-viou-ly stated, a double fluoride 



i'.im and aluminium. It has been brought 

 into use recently as a source from which to 

 obtain both tho earth-metal and the alkali- 

 ii'etal bases present in it, the employment of 

 the mineral with such view having been, it is 

 said, introduced by Prof. Julius Thomsen, of 

 Copenhagen. Of the product of the Green- 

 land mines, a considerable quantity had been 

 already contracted for yearly in Denmark (and 

 perhaps in Germany also), when about the 

 close of the year 1864, the "Pennsylvania Salt 

 Manufacturing Company," having its works 

 near I'ittsburg, through agents sent to Copen- 

 n for the purpose, contracted with Messrs. 

 Shu re and Sons, owners of the mines, and with 

 the Government, for all the excess yearly of 

 the cryolite mined, over the quantity previously 

 secured for European consumption. Ships were 

 thereupon chartered in England, at Quebec, 

 and in American ports, to proceed to Ivigtus, 

 Greenland, lat. 59, load with the mineral, and 

 deliver it at Philadelphia. The force at the 

 mines has been increased, and the American 

 contract is said to cover from one-half to two- 

 thirds of the total product. Up to October, 

 1865, about 6,000 tons of cryolite had been im- 

 ported for the works of the company referred 

 to, and the quantity received in 1806 was ex- 



1 to be about 11,000 tons. 



The process of extraction is said to be essen- 

 tially tho 1'anish: cryolite and lime are pul- 

 verized, mixed, and calcined : fluoride of cal- 

 cium and aluminate of soda result; and the 

 latter being treated with carbonic acid, car- 

 bonate of soda is formed, being of course soluble 

 in water, while the alumina is precipitated. 

 Besides the bicarbonate named, the company 

 produce from tho cryolite also caustic soda, sal- 

 soda, and the concentrated soda-lye, or ''sapon- 

 it'uT ; " tho last-named product being original 

 with them, and patented. 



Oxidation of Crude Soda Liquort. The lye 

 obtained from crude soda, or u black ash," 

 usually containing a small quantity of sulphide 

 of sodium, of which, especially for tho prepara- 

 tion of tho solid caustic soda, it is desirable to 

 be rid, Mr. J. Hargreaves, of Lancashire, has 

 invented an apparatus intended to be iiM-d (in 

 place of tho old methods with atmospheric air, 



nitre, bleaching powder, etc.) for converting 

 ilphidc into the insoluble and easily re- 

 movable sulphate of soda. Tho principle is that 

 of blowing through the lixivium, contained in 

 a deep vessel, and from the bottom upward, a 

 cunvnt of mingled steam, at 40 Ibs. pn 

 and air. Oxidation of tho sulphide takes place ; 

 and in course of afi-w hours the conversion into 

 sulphite, and from that to sulphate is so nearly 

 complete, that the use of an extremely small 

 quantity of nitrate in the solution then suffices. 

 See Chemical News, June 8, 1866. 



Sulphate of Soda and Chloride of Potattivm 

 from Sea-water. M. Balard, after years of 

 study and labor, has succeeded in extracting eco- 

 nomically from sea-water the two substances 

 named, and which are of so great importance in 

 connection with a class of large chemical workg. 

 The usual production of the first, involving 

 an immense consumption of common salt and 

 sulphuric acid, has been described ; while for the 

 salts of potash the dependence has hitherto been 

 largely upon the ashes of North American 

 forests. M. Balard's plan has been thought 

 likely to place the French nation independent 

 alike of both these sources of supply. In this 

 plan great quantities of sea-water are in the 

 early spring run from the Mediterranean into 

 large shallow reservoirs. During the summer, 

 evaporation to some extent occurs, and a quan- 

 tity of common salt separates ; and the concen- 

 trated liquor is then stored in other reservoirs 

 until winter. It is then again run back into 

 the shallow pits, in which, during a cold night, 

 it throws down large quantities of sulphate of 

 soda. The mother-liquors remaining after this 

 deposit are next introduced into a Carre's appa- 

 ratus, and exposed to an intense cold ; they thus 

 yield considerable quantities of a double chlo- 

 ride of magnesium and potassium ; and this, sub- 

 jected to heat in a furnace, gives chlorhydric 

 acid, magnesia, and chloride of potassium. 



In M. Carry's method, cold is produced by 

 means of a saturated solution of ammoniacal 

 gas contained in one of two suitably-connected 

 vessels : by heating this one, the gas is driven 

 over into the other, and in which, surrounded 

 by cold water, it liquefies by ite own pressure. 

 Tho heat being removed from under the first 

 vessel, its temperature falls ; the liquid in it re- 

 absorbs the gas which had been driven off, and 

 the rapid evaporation of the latter from the 

 second vessel, into which it had been con- 

 densed, now recessitates a corresponding ab- 

 sorption of hc-at from contiguous solids or 

 liquids : the liquors previously referred to being 

 at this point brought in contact w ith the walls 

 of the second vessel, the precipitation already 

 mentioned takes place. 



Preparation of Pure Soda.N. \V6hler 

 (Liebig's Annalcn, September, 1861) finds that 

 when nitrate of soda is heated along with bin- 

 oxide of manganese in closed vessels, no man- 

 ganate of soda is formed, and the decomposi- 

 tion is so complete that this process may be 

 used for the preparation of a pure caustic soda. 



