[ 377 ] 

 LXIV. ISlemoir vpon Zircon. By M.CiiY.\Rv.vi.*, 



1 HE zircon on which the author made his experiments was 

 l/i-oiight i'roin the island of Ceylon. 



Hydrochloric acid, mixed w'ith nitric acid, separated from it 9 

 gi-eat tleal of peroxide of iron and a triice of oxide of titanium 5 

 bat the latter is not essential to t!ie composition of zircon. 



(a) A portion of zircon, which had been previously treated 

 with nitro-nuiriatic acid, was plimged in double its weight of a 

 solution of potash in alcohol, with which it was exposed to a 

 cherry red temperature in a silver crucible ; the water separated 

 from the heated mass a considerable quantity of potash, retain- 

 ing traces of silex and of zircon. 



{I) The matter undissolved by the water was a compound of 

 silex, of zircon, and of potash, which maybe considered as a sort 

 of double :saU ; this compound has the following properties. 



(c) It is of the most beautiful white j it remains a very long 

 tmie in suspension in distilled water. It precipitates itself on the 

 contrary very promptly from a solution of potash, which proves 

 that pure ivater has an action upon it which alkalized water has 

 not: It is not impossible that this depends upon an attraction which 

 the pure '.vater exerts upon tlie potash which it (the compounc^) 

 contanis : m this view of the matter, it may be easily conceived 

 wny the water which is already united to this base has nolongeir 

 any action on the compound. 



{d) It is wholly soluble in weak hydrochloric acid; by eva- 

 poratmg, the silex is precipitated, and there remains in the liquor 

 chlorurct of potash, and hydrochlorate of zircon containing a lit- 

 tle hydrocldoruret of iron : ammonia precipitates these two bases, 

 (e) The following is the process wiiich M. Chevrcul has fol- 

 lowed to obtain the zircon separate from iron, a result which 

 no person before him has been able to accomplish. Me fused the 

 zircon containing iron with potash in a silver crucible : he e.\;- 

 hausted the mass of all the matter soluble in water which it con- 

 tained. There remained a zirconate of potash, blended with 

 oxides of iron, of copper, and of silver (the two latter proceed- 

 ing from the crucible). He poured upon this zirconate concen- 

 trated hydrochloric acid; there was an immediate disengagement 

 of heat, of steam, and of hydrochloric gas. The substance, now 

 \n the state of a soft paste, was put into a glass cylinder of an 

 inch in diameter and five inches in length ; concentrated hydro- 

 chloric acid was added to it, until that acid detached from the 

 matter contained in the cylinder nothing but hydrochlorate of 

 zircon and chlorurct of potash. This was ascertained— 1st, by 

 the washing mixed in water not precipitating chlorurct of silver; 



• From Bulletin de la Soci^ti Pkilomatiqvc, 



Vol. 55. No. 265. May 1820. K k 2<?, 



