386 Hillebrand — Occurrence of Nitrogen in Uraninite. 



a generator and not by the introduction of Na 2 C0 3 into the 

 tubes themselves. With the observation of this and other 

 precautions detailed in the unabridged article the results of 

 titration with KMn0 4 leave nothing to be desired as regards 

 accuracy. 



The analyses which follow were with two exceptions — Y and 

 XYIII — made before recognition of the nature and import- 

 ance as regards quantity of the gas given off by acid, and 



North American Uraninites. 



Connecticut. 



Glastonbury. 



Col- 

 orado. 



North 

 Carolina. 



VIII. 



IX. 



UO3 -. 



ro 2 .. 



Ti0 2 .. 

 ZrC? . 

 ThOo . 

 Ce0 2 _. 

 (La.Di) 

 (T,Er) 2 

 Fe 2 3 . 

 PbO .. 

 ZnO .. 

 FeO „ 

 MnO .. 

 CaO .. 

 MgO .. 

 Alk. .. 

 H 2 .. 



2J 



Si0 2 __ 

 P 2 5 _. 

 Aso0 5 - 



PI 



CuFeS 2 

 FeS 2 __ 

 Cb 2 5 . 



2208 23-35 22'22 26-48 2303 13-27 2P54 

 59-13 58-01 59-31 5 7 "43 59'93 72.25 64-72 



-- 1 



O a 



9-57 



9 78 



•46 



9 79 



v 10-31 



1-21 -33 -67 



3-14 324 3-07 



■08 



tmdet. 



•97 tmdet. undet. 



undet. undet. undet.. 



106 -25 



•96 



11-10 



13 

 20 j 



40 .29 



26 3.08 



•33 



7-20 6-93 



•11 "28 

 4-35 4-34 



trace. 



•08 



•61 

 undet. 

 ■16 



•11 



■10 



•18 



■07 



•22 



14-00 

 70-99 



6-52 



•27 

 4.35 



•30 



•43 



•68 



■67 



•68 



2-41 



undet. 



undet. 



2-63 



•16 



•03 



13 



•20 



•02 









•04 









25-26 

 5851 j 



trace. 



7-59 



•22 



•70 

 •44 

 •32 



•16 



•84 



1-96 

 •15 



2-79 

 ■22 



•43 



■12 

 ■24 



5083 

 3931 



44-11 

 46-56 



2-78 

 •26| i 

 •50 

 •20 j 

 trace. 



4'20 



3-04 



453 



•85 

 •30 



•23 



•25 



< i 



1*21 undet. 

 •37 tmdet. 



•08 



•13 



Insol. 



•85 



1-74 



•42 



•70 -89 



■04 



•14 



1-40 



•10 



•06 



Total 



99-05 



96-91 



96-25 



99-49 101-49 



98-21 



99-37 



101-49 



99-95 100-99 



98-91 



Sp.G. ... 



9-139; 



9-051 





9-587 9-622 



9-733 



9560, 



9-348 



8-068 9-086 : 



9-492 



their object was chiefly to ascertain the relative percentages of 

 U0 2 , ITO3, and rare earths with a reasonable degree of close- 

 ness. Unusual pains to secure very accurate summations were 

 therefore not taken except in analysis Y, and this was un- 

 fortunate as will appear later. 



Comstock and Blomstrand both assumed that the iron found 

 by them existed as FeO, but for reasons which cannot be 



