34? ANALVStS OF *HE PYROPHTSALtT*. 



Attacked by Soda attacks it with a little effervescence, and produces a 

 soda. 



porous mass. 



Where found. This stone was found by Mr. Gahn, at Finbo, near Fah- 



lun, about three quarters of a league west of the town, 6ft 



the road to Sundborn. The nodules are imbedded in a 



granite composed of white quartz, feldtspar, and silvery 



mica, the lamina? of which are rhomboidal and in hexagonal 



prisms. The nodules are separated from the rock by thin 



scales of mica, covered bj^ a talcous substance of a greenish 



yellow colour. 



Its dfferenre Jt differs from feldtspar, to which it appears to have most 



par. resemu ] ance> m having b u t one determinate direction in 



which it cau be split, while feldtspar has two. Trie specific 



gravity of feldtspar too is but 2*704, and besides it is much 



less difficult to fuse. 



Analysis. x The following analysis was undertaken conjointly with 



Mr. Berzelius. 

 Powdered. Two hundred grains of pyrophysalite, reduced to fine 



powder in a mortar, acquired an increase of weight of four 

 grains. 

 Heated alone. a. These 204 grains, having been kept at a red heat in the 



fire for three hours, lost 1 '$ grains. 

 Treated with b. On adding 600 grains of carbonate of potash, and ex- 

 carbonate of p OS ' ul or the mixture to a red heat for three hours in a platina 



potash, una • , , 



muriatic acid, crucible, a colourless mass was obtained, perfectly soluble 



in muriatic acid. This solution being evaporated to dry- 

 ness, and diffused in water with a very little muriatic acid, 

 the silex was obtained, which, after having been washed and 

 Silex. heated red hot for half an hour, weighed 6(v c 25 grains. 



Precipitated by c. The sdlutiou in water was precipitated by carbonate of 

 carbonate of potash, which was added in excess, taking care to keep the 

 liquor boiling during the process. The precipitate obtained 

 wag dissolved in caustic potash, except a small portion of a 

 yellowish powder. 

 Neither glu- <L To t)m liquor precipitated by carbonate of potash mu- 

 rine, zircon, ^atic acid was added in excess, and caustic ammonia, with- 

 noryttria. . , . 



out the liquor undergoing any change : a proof, that it con-* 



tuined neither glucine, zircon, nor yttria. 

 Muriat?ofam- «• To the solution in caustic potash muriate of ammonia 

 nxmiaaddedto was u dded, and it was boiled till the ammonia was expelled 



