Hillebrand — Occurrence of Nitrogen in Uraninite. 387 



detailed in this paper I have preferred to consider it generally 

 as Fe„0 3 . The values given for [TG 2 and U0 3 are therefore sub- 

 ject to a correction if this assumption should prove unwar- 

 ranted, but the amount of iron found is so small as to affect in 

 no way the conclusions drawn from the analyses. It is highly 

 probable from an experiment made on the material of analysis 

 Y that none of the iron belongs to uraninite, but is simply de- 

 rived from foreign bodies from which it is practically impossi- 

 ble to free the mineral entirely. It is probable that in all cases 

 but Y and XYIII the total percentage of earths is somewhat 

 too low. Oxalic acid always leaves a portion of the earths with 

 uranium, and the remainder can only be recovered by pre- 

 cipitation as nitrates by ether from a neutral solution. This 

 was done only in the two cases mentioned, which in point of 

 time post-date all other analyses. 



Norwegian Uraninites. 





Annerod. 



JElvestad. 



Elvestad. 



Skraatorp. 



Hug-yen- 

 askilen. 



Arendal. 



Arendal. 





XII. 



XIII. 



XIV. 



XV. 

 32-00 



XVI. 

 35-54 



XVII. 

 41-71 



XVIII. 



uo 3 ... 



3063 



25-36 



22-04 



26-80 



TT0 2 



46-13 



50-74 



4303 



43-88 



43-38 



24-18 



44-18 



Zr0 2 ? 



•06 



■08 



1 











Th0 2 



6-00 



8-48 





8-98 



6-63 



) 



4-15 



Ce0 2 



•18 



•21 



y 8-43 



•17 



•20 



}■ 3-66 



none 



(Di,La) 2 3 __ 



•27 



•26 



1 



•36 



•23 



1 



■67 



(Y,Er) 2 3 --- 



Ml 



1-10 



J 



•97 



1-03 



9-76 



9-05 



Fe 2 O s 



•25 



•21 



•30 



•09 



•32 



•03 



•24 



PbO. 



9-04 



10-06 



8 58 



9-46 



9-44 



10-54 



10-95 



MqO 





•06 





■ 









CaO 



•37 



•77 



•37 



•36 



•41 



1-06 



•61 



MgO _.. 



Alk 



[■ trace. 



y trace. 



1 ' 13 



y trace. 



\ - 



•10 



•23 



•04 

 •15 



HoO... 



•74 



■73 



•74 



•77 



•79 



1-23 



imdet. 



N" 



1-17 



1-28 



1-08 



1-03 



1-08 



undet. 



1-24 



Si0 2 . 



•22 



•38 



■29 



•53 



•49 



■90 



■50 



P 2 5 



•02 



•04 



trace. 



? 



trace. 





trace. 



Insol. . 



4-42 



•45 



15-45 



1-54 



■42 



100-09 



8-930 



1-10 

 94-50* 

 7-500 



1-19 



Total 



100-61 



100-21 



100-44 



100-14 



99-77 



Sp. G. 



8893 



9 145 



8 320 



8-966 





Want of space forbids reproducing in this article numerous 

 explanatory notes and the separate figures of which the above 

 are in many cases the mean, without which the accompanying 

 tables should on no account be used as a basis for criticism. 



The Glastonbury material was all from Hales's quarry in 

 the town of Glastonbury, a few miles N.E. of Middletown, 

 and was obtained through various channels. That from 



* The loss in this analysis is supposed to be mainly accounted for by C0 2 . 



