Intelligence and Miscellaneous Articles. 553 



with the gangue ; as soon as the adhering impurities have been 

 removed, the mineral dissolves without effervescence. 



The following results of an analysis will show conclusively that 

 the nemalite is essentially hydrate of magnesia, or brucite, from 

 which it does not differ otherwise than by being in a fibrous state : — 



Magnesia 62*89 



Protoxide of iron 4*65 



Carbonic acid 4' 10 



Water (by loss) 28-36 



100-00 



A small portion of magnesia is replaced by protoxide of iron. 

 The formula of brucite, MgO, HO, requires — 



Magnesia 69*67 



Water 30*33 



100-00 



Boston Journal of Natural History, vol. vi. p, 36. 



ANALYSES OF PECTOLITE AND STELLITE, AND PROPOSED UNION 

 OF THESE TWO SPECIES. BY J. D. WHITNEY. 



Pectolite occurs on Isle Royale, Lake Superior, in spheroidal 

 masses, consisting of delicate silky fibres radiating from a centre, 

 which exactly resemble the foreign specimens of this mineral from 

 Monte Baldo. The radiated stellated mineral from Bergen Hill, 

 New Jersey, which was analysed by Beck, and supposed by him to 

 be identical with the stellite of Thomson, agrees also in external 

 characters with the pectolite. Specimens from Isle Royale and from 

 Bergen Hill fuse, like pectolite, readily, with but little intumescence, 

 to a colourless glass. They are easily dissolved by hydrochloric 

 acid, the silica separating as a fiocky powder. 



The following are the results of the analysis of specimens of the 

 pectolite and stellite : — 



99*69 100-00 99-85J.S.K. IOMOg.j.d. 



I. tind IL are specimens from Isle Royale. No. I. contains a con- 

 siderable portion of alumina, which is evidently not essential to the 

 composition of the mineral, since II., resembling it entirely in ex- 

 ternal appearance, gives only 1^- per cent. The silica in both these 



Phil. Mag. S. 3. No. 2\Q. SuppL Vol. 36. 2 O 



