l^Cf Intelligence and Miscellaneous Articles. 



The following rocks were examined for phosphoric acid: — 1st, 

 porcelain earth from Aue in Saxony ; 2nd, porcelain earth from 

 Bayonne ; 3rd, gray vesicular lava from Niedermennig on the 

 Rhine ; 4th, white trachyte from the Drachenfels; 5th, basalt from 

 the Meissner in Hessia ; 6th, Trass from Vesuvius. 



The following was the mode of examination: — The finely-pul- 

 verized rocks were fused with 4 times the quantity of chemically- 

 pure soda, the fused masses digested in water, and the liquids filtered 

 from the insoluble residues neutralized with nitric acid. These neu- 

 tralized liquids were now evaporated to dryness, and after treatment 

 with water and separation of the silicic acid, tested with nitrate of 

 silver and the other known reagents for phosphoric acid. 



In all the above rocks, however, not the least trace of phosphoric 

 acid could be detected ; consequently the above-mentioned observa- 

 tions of Dr. Fownes are founded on some error*. In the gray vesi- 

 cular lava from Niedermennig there was found a quantity of chlo' 

 rine ; and on boiling it in the pulverized state with water and eva- 

 porating the liquid, small quantities of chloride of sodium were ob- 

 tained ; at the same time with this a brown organic substance was ex- 

 tracted, which coloured the water brownish on evaporation and was 

 carbonified on ignition. — Journ.fiir Prakt. Chem., March 31, 1845. 



EXAMINATION OF SOME NATIVE AND ARTIFICIAL COMPOUNDS 

 OF PHOSPHORIC ACID. BY C. RAMMELSBERG. 



Wagnerite (Pleuroklase). 



"We are indebted for the only analysis of this exceedingly rare mine- 

 ral to Fuchs, who obtained in the year 1821 the following results : 

 phosphoric acid4r73 per cent., magnesia 46' 66, peroxide of iron 5*0, 

 peroxide of manganese 0"5, hydrofluoric acid 6*5 . Fuchs decomposed 

 the mineral with sulphuric acid, and separated the sulphate from the 

 phosphate of magnesia by water. The phosphate of magnesia was 

 decomposed by boiling it with a solution of potash. The phosphoric 

 acid and fluorine were not directly estimated. If his method of 

 analysis be minutely examined, the results are seen to be only ap- 

 proximative, and a repetition of the analysis would be very desir- 

 able. In the specimens selected by the author for analysis, there were 

 large, opake, reddish, and small transparent, wine-yellow^ crystals 

 of wagnerite, imbedded in a green aluminous mass and accompanied 

 with quartz, calcareous spar and bitter spar. Its specific gravity, 

 according to Fuchs, is 3* 13. The author found it 3*068 at a tempe- 

 rature of 57° F. in the transparent parts, and 2*985 in the opake 

 portions. 



Three analyses were made by methods differing as widely as pos- 

 sible. 



1 . The substance reduced to a fine powder was treated with sul- 

 phuric acid in a platinum crucible. This, even in the cold, caused 

 the evolution of fumes of fluoride of silicium from the admixture of 



* The observations of Dr. Fownes have, however, been fully confirmed 

 by W. Sullivan, Esq., as will appear from a communication to be inserted 

 in our next. — Ed. Phil. Mag. 



