46 Remarks on the Crude Sodas of Commerce. 



with some modifications, is still practised, was invented by 

 Messrs. Leblanc and Dize. The process is briefly this, — it 

 consists in decomposing the muriate of soda, by sulphuric 

 acid. The sulphate of soda, thus formed, is intimately uni- 

 ted, in certain proportions, with charcoal and chalk pulveri- 

 zed. By the application of a suitable temperature, in a 

 reverberatory furnace, a somewhat complicated series of 

 chemical changes takes place. It has been supposed that 

 sulphate of soda is decomposed, a part of the sulphur of the 

 sulphuric acid, being consumed in the form of sulphuretted 

 hydrogen, forms slight explosions, and exhibits the appear- 

 ance of fire works, while the unconsumed sulphur, remains 

 in combination with a portion of soda and lime, forming hy- 

 dro-sulphurets, sulphates and sulphites. In the meanwhile, 

 the carbonic acid of the lime, and that formed by the com- 

 bustion of the charcoal, unite with the soda, and form the 

 carbonate of soda. This part of the process, requires con- 

 siderable tact in its management, as the value of the article 

 depends upon the completeness of the decomposition of the 

 sulphate of soda, and the quantity of carbonate of soda that 

 is formed. The process lasts about seven hours, and the 

 residuum, thus obtained, resembles in its appearance fine ba- 

 rilla.* 



A considerable quantity of the artificial barilla, has been 

 imported into the United States. In consequence however, 

 of the badness of the article in some instances, but espe- 

 cially from the quantity of sulphur, that even the best con- 

 tains, it is entirely fallen into disrepute. So little is it es- 

 teemed in this market, that the soap makers, who are the 

 principal consumers, as several of them have declared to 

 me, would not accept the article as a present, though they 

 are sensible that it contains a large proportion of alkali. 

 They find the ley, obtained by the lixiviation of the artificial 

 barilla, contains so much sulphur, that when boiled and 

 mixed with the other materials for making soap, the quanti- 

 ty of sulphuretted hydrogen disengaged, is so great, as to 

 render the works almost untenantable, while the soap be- 

 comes of a dirty blue color, and is rendered unsaleable. 



Knowing that this substance is generally employed in the 

 soap manufactories of Marseilles, and that these inconven- 

 iences are not complained of there, I was induced to enquire 



* For a particular account of the process, see Ann. de Chim. v. 19. 



