4 



NuttaWs Geological and Mineralogical Remarks. 247 



These are accompanied, near the junction of the granite and 

 crystalline carbonate of lime, with large crystals of felspar, 

 scapolite, or vvernerite, and something which borders on 

 spoduraene. On the margin of the mill pond at the furnace, 

 where some repair was making, a vein of arsenical pyrite, 

 mixed with others resembling the sulphuret of cobalt or 

 nickel, with a substance somewhat like blende, was found, 

 and likewise accompanied by the condrodite. 



In another limestone abounding with sphene, dark colour- 

 j .^ ed granules, and minute crystals of augite, there are nu- 



merous and generally amorphous, dull grayish blue nodules 

 imbedded, which by goniometrical measurement indicate 

 some variety of fluate. It is nearly quite opaque, but 

 fusible Into a white enamel ; both externally and in- 

 ternally dull, and minutely splintery or granular in the frac- 

 ture. It is commonly so much penetrated by the car- 

 bonate of lime and titanium oxyd as seldom to present any 

 angle which can be measured. Its hardness is about that 

 of coma^on fluor- It is very feebly acted upon by acids in 

 the cold, but still slowly gives out minute bubbles- When 

 examined it will probably prove the argillaceous fluate of 

 lime, of which I have never seen specimens. 



The crystalline calcareous rock, which here alternates with 

 ^•anitines of felspar and quartz, or with beds ofsienitic gran- 

 ite, (near to Doctor Fowler's house, the proprietor of i\\e 

 Franklin works,) disappears, and a confluent grauvvacke, 

 almost porphyritic, and contemporaneous apparently WMth 

 the other formations, appears directly overlaid by a bed of 

 leaden minutely granular, secondary limestone, containing 

 organic remains of the usual shells and corallines, and lay- 

 ers of blackish hornstone or petrosilex. This rock, as well 

 as the grauvvacke Jene^fA, presents disseminated crystals of 

 blue fluate of lime. In the limestone the cavities are some- 

 times very numerous, and lined both with pseudomorphous 

 masses and cubes of blue and white fluate and quartz crys- 

 tals* 



Thus we have here before us, as at lake Champlain, Uie 

 novel a 

 of rock; 



§1 



lid interesting spectacle oT an union of every class 

 5, but passing decidedly into each other as if almost 

 conietnporaneovs f If they are' not contemporaneous, how 

 <Jo they happen to penetrate each other by veins ? Why 

 do they present similar mineral substances ; similar organic 

 remains ; why do the same relicks of plants occur over the 



