Hillejbrand — Occurrence of Nitrogen in Uraninite. 



from the above four different quarries about Moss belong to 

 one and the same mineral species, just as may be said of the 

 mineral from the two Connecticut localities. While analysis 

 XII differs in some respects from Blomstrand's analysis of 

 Broggerite it simply serves to show that the mineral may vary 

 in composition in the same quarry. Leaving out of considera- 

 tion for the present the nitrogen, it is certain that the ortho- 

 uranate formula derived by him from his analysis cannot be 

 obtained from No. XII. A comparison of analyses XIII and 

 XIY with Lorenzen's analysis,* coupled with Professor Brog- 

 ger's words given above and the fact that not one of the speci- 

 mens from the neighborhood of Moss above analyzed contains 

 less than 8 per cent of earths, gives rise to the strongest possible 

 suspicion that that analyst has overlooked thoria altogether, 

 notwithstanding the fact that the present material is from 

 Elvestad and Lorenzen's was from Huggenaskilen. The pos- 

 sibility of a mistake as to the source of Lorenzen's material is 

 suggested by the totally different ratio between U0 2 and U0 3 

 in the specimen from Huggenaskilen sent by Professor ISTor- 

 denskiold (No. X.Y1). If it should prove that Lorenzen over- 

 looked thoria, another of Blomstrand's supports in favor of the 

 ortho-uranate formula for all uraninites, including Broggerite 

 and Cleveite, is knocked away, the first being the earlier and 

 as shown incorrect analysis of Branchville uraninite. 



The oxygen ratios calculated for analyses XII to XYI, 

 counting all earths as thoria, whereby the comparison is very 

 little affected, since the percentages of other earths are almost 

 alike in all analyses, are as given below, as also the ratio for 

 Blomstrand's Broggerite, in which FeO has been changed to 

 Fe 2 3 and a corresponding change made in the II0 2 and U0 3 

 in order to compare properly with the others. 





Mol. "Wt. 



XII. 



XIII & XIV. 



XV. 



XVI. 



Broggerite. 



uo 3 .... 



U0 2 



Earths .. 

 PbO .... 



287 

 271 

 266 

 223 



5-36 1 

 5-70) 



•96 W'37 



•68 ) 



4-31 1 

 6-01 ) 

 1-21 J- 1-85 

 •73 ) 



5-44 1 596 1 

 5-26) 5-14) 

 1-28 [ 1-33 '98 [ 1-14 



•69 ) -68 ) 



6-07 1 

 5-15 ) 

 102 [ 1-11 

 ■60 J 



It is seen that none of the ratios conform even approximately 

 to that for Blomstrand's analysis except that of the mineral 

 from Huggenaskilen. A re-calculation of all with Fe 2 3 instead 

 of FeO and consequent changes in TT0 2 and U0 3 and separation 

 of the earths would give the normal ratio 1 : 1 for Blomstrand's 

 analysis, but the others would differ from it more widely than 

 in the above exhibit. 



* Nyt Mag. f. Naturv., xxviii, 249. 

 CaO -21, H 2 -70, Si0 2 -31 (99-84). 



U0 3 38-23, U0 2 5042, PbO 9-72, FeO -25, 



