Correspondence of J. Nickles. 



99 



5. Epiglaubite. 



In small aggregates, or interlaced masses of minute semi-trans- 

 parent crystals of a shining vitreous lustre, which are always 

 implanted upon druses of glaubapatite. H. = about 2*5. 



Yields abundance of water when heated in a close tube. Inso- 

 luble in water, until after addition of hydrochlyric acid, when it 

 disappears without effervescence. Melts easily into a semi-trans- 

 parent colorless glass tinging the flame green. It is a largely 

 hydrated phosphate, chiefly of lime. It may also contain mag- 

 nesia and soda ; but at present the quantity in my possession is 

 too small to determine more accurately its composition. It would 

 appear to be rare at the locality. 



It is named from its position, upon the previously described 

 species. 



Art. XI. 1 — Correspondence of M. Jerome Nicklhs, dated Paris, 

 April 26th, 1856. 



Report on the history of the manufacture of Artificial Soda. — The 

 question of priority as to the process of manufacturing artificial soda has 

 just been the subject of thorough investigation by the Academy of Sci- 

 ences. This work was called forth by the Minister of Public Instruction 

 at the request of the children of Leblanc, author of the process which 

 bears his name. Another claim, that of the children of Dize, collaborator 

 of Leblanc, being presented at the same time, the Section of Chemistry in 

 the Academy of Sciences was obliged to proceed to a historical and bib- 

 liographical research which has resulted in a complete elucidation by M. 

 Dumas of this important point in the history of Science. 



The discovery of the process which derives soda from marine salt was 

 made by Leblanc, who was also the first to give it a trial. It was not 

 till afterward that he associated himself with Dize, then chemical assist- 

 ant at the College of France. 



Nicholas Leblanc was born in 1*743. Toward 1*780 he was attached 

 as surgeon to the household of the Duke of Orleans. He commenced in 

 1*785 his communications upon crystallization which gave him a distin- 

 guished rank among the chemists of the time. His first researches upon 

 methods of obtaining soda economically, date from 1*784. This problem 

 had already been broached, and different processes had been proposed 

 for making soda from marine salt either by means of lime, or by means 

 of the oxyd of lead, but without industrial results. 



In 1*7*77, Father Malherbe, a Benedictine, pointed out a process of 

 converting marine salt first into sulphate of soda which he afterwards 

 decomposed by means of charcoal and iron ; a process which has quite 

 lately been put in practice by Mr. E. Kopp, as has been already men- 

 tioned in this Journal.* 



In 1*789, De la Metherie proposed to convert marine salt into" sulphate 

 of soda, and to reduce this sulphate by carbon. This reduction would 



* Corr. of J. Nickles, Nov. 1, 1855. 



