358 Occurrence of Phosphoric Acid in Minerals and Bocks. 



of Dublin, publislies the following list of tlie rocks and minerals 

 which he examined for phosphoric acid. He notices, also, 

 those in which potash and soda occur — that is, those rocks in 

 which these substances had not hitherto been noticed : — 



Rocks. 

 Nine varieties of carbo- 

 niferous limestone from 

 the neighbourhood of 

 Cork. 



Muschelkalk and dolomite 

 from the same forma- 

 tion, from near Fulda 

 in Hesse-Casel. 



Roofing-slate used at Gies- 

 sen. 



Flags used in the west of 

 Ireland, supposed to be 

 millstone grit. 



Slate from Corrigaline, 

 near Cork. 



Old red sandstone, Cork. 



Phosphoric Acid. 

 In all I could detect its 

 presence, and in one it 

 occurred in sufficient 

 quantity to be deter- 

 mined. 



Present, but apparently 

 more abundant, in the 

 dolomite. 



Considerable precipitate, 

 but wavellite is found 

 in some localities in the 

 same rock. 



Traces, but very minute. 



Precipitate large enough 

 to examine quantita- 

 tively. [This is the best 

 locality known, I be- 

 lieve, for wavellite.] 



Trace in one specimen, 

 but a decided precipi- 

 tate was obtained from 

 three ounces of another. 



Alkalies. 



Potash was found present 

 in all, but in such small 

 quantity that I could 

 not determine it. From 

 the same cause I could 

 not determine whether 

 soda was present. 



Minute traces. 



Lai'ge precipitate, with 

 chloride of platinum 

 and a small trace of 

 soda. 



Trace of potash, but could 

 not ascertain if soda 

 was present. 



Decided precipitate with 

 chloride of platinum. 

 Sufficient soda to pro- 

 duce a precipitate with 

 antimoniate of potash. 



Could not detect soda, 

 but detected a trace of 

 potash. 



Sim]-le Minerals and Rocks. 



Diorite containing augite, from the 

 valley of the Lahn, Nassau. 



Clinkstone, from Rhbngebirge, Bavaria. 



Phonolitic Tvfa, Pvhbngebirge, Bavaria. 



Eoniblende in crystals, from Khonge- 

 birge. 



Olivine, in a state of decomposition, 

 from the Vogelsgebirge, Hesse- 

 Darmstadt. 



Augite, crystalline, Rhbngebirge. 



Compact basalt, from Giessen. 



Tr^p rock of the nature of greenstone, 

 from the north of Ireland. 



Basalw, Giant's Causewa;, . 



Pumice stone, from the Lake of Laach, 



near Andernach, on the Rhine. 

 Sodalite, Vesuvius. 



Variety of hupersthene, occurring in 

 the diorite on the Lahn, Nassau. 



Phosphoric Acid. 

 Obtained sufficient from two ounces 



to test with nitrate of silver. 

 Abundant traces. 

 Considerable precipitate. 

 Alinute traces. 



Sufficient to apply the test of nitrate 

 of silver ; but three ounces were 

 employed. 



Abundant traces. 



Considerable traces. 



Only minute traces in one specimen, 

 but in considerable quantity in an- 

 other. 



Enough to produce a precipitate with 

 sulphate of ammonia and magnesia 

 from two ounces. 



Considerable precipitate from three 

 ounces. 



Trace ; had not enough for a second 

 analysis. 



Distinct traces. 



