1824.] M. Berzelius on Fluoric Acid. 337 



the newly precipitated oxide in fluoric acid. The solution has a 

 rose red colour, and affords a pale rose red coloured salt by- 

 evaporation. 



Filiate of Oxidule. — A green crystalline mass, easily soluble 

 in water. 



Filiate of antimony is very soluble in water, and may be 

 obtained in colourless crystals by spontaneous evaporation. Its 

 taste resembles that of tartar emetic. 



Filiate of oxidule oftinis easily soluble in water, and crystal- 

 lizes in white, shining, opaque prisms. It becomes rapidly per- 

 oxidized when exposed to the air. 



Filiate ef Oxide of Uranium. — A white pulverulent salt, 

 readily soluble in water, and affording a yellow coloured 

 solution. 



Fluate of Silver. — A very soluble deliquescent salt, whose 

 properties have been already sufficiently described by Gay- 

 Lussac and Thenard. 



Filiate of oxide of mercury crystallizes in dark yellow coloured 

 prisms. Water decomposes these crystals, and a portion of the 

 oxide remains undissolved, id the state of a beautiful yellow 

 subsalt, resembling tinpeth mineral. Ignited in a platinum 

 vessel, the neutral salt sublimes, and forms light yellow coloured 

 crystals ; but a portion of it at the same time undergoes decom- 

 position, and the platinum is corroded. In a glass retort it is 

 instantly decomposed, and there distils over a mixture of sili- 

 cated fluoric acid gas and metallic mercury. Ammonia con- 

 verts this salt into a white coloured double salt, containing an 

 excess of base. 



Fluate of Oxidule of Mercury . — I could not succeed in pre- 

 paring, either by distilling the fluate of oxide with mercury by 

 treating calomel with a solution of fluate of soda, or by evapo- 

 rating over mercury a mixture of fluoric acid and a solution of 

 nitrate of oxidule of' mercury. In the last experiment, the nitrate 

 of mercury reappeared in crystals, and the fluoric acid did not 

 produce the slightest decomposition. 



Fluate of Oxide of Platinum. — It is generally considered 

 difficult to combine oxide of platinum with any other acid than 

 the muriatic : this object may however be easily effected by 

 dissolving in water a quantity of the salt of potash whose acid 

 we wish to combine with the oxide, and by mixing the solution 

 with muriate of platinum so long as it continues to produce a 

 precipitate. A small quantity of the muriate of platinum and 

 potash remains in solution, but by evaporating the clear liquid, 

 tin: whole of this may be made to separate in crystals. S had 

 recourse to this method in preparing the fluate of platinum. The 

 clear liquid was evaporated to dryness, and the residue was 

 treated with alcohol, which dissolved the fluate, but left the 



New Series, vol. vjii. z 



