66 Mr David Forbes on the Chemical 



Which, when tabulated will stand as follow : — 





In 20-81. 



In 100. 



Oxygen 



Columbic acid, 



8-03 



38-58^ 



? 



Titanic acid, with some \ 9 .qq 

 columbic acid, 



14-36 f 52 ' 94 5-79 



Alumina, 



•65 



3-12 



1-45 



Lime, 



•28 



1-37. 



0-38 



Magnesia, 



•04 



0-19 



0-07 



Yttria, 



6-11 



29-36 



•12 



Protoxide of cerium, 



•68 



3-31 



0-47 



Protoxide of iron, . 



•41 



1-98 



0-43 



Protoxide of uranium, 



1-08 



5-22 



61 



Water, 



•60 



2-88 



2-56 



20-87 100-37 



As we have no fixed atomic equivalent for either columbium 

 or yttrium, we cannot calculate the amount of oxygen, but 

 taking them at the old numbers of 180 and 32, the oxy- 

 gen will be 4-53 in the columbic acid, and 5*87, in the yttria, 

 which will make the relation of the amounts of oxygen as 

 10-32 in the acids to 10'73 in the bases ; but it is useless at- 

 tempting to deduce a formula from this analysis until we 

 have more information as to the composition and atomic equi- 

 valent of columbic acid and yttria. 



For the sake of comparison Scheerer's result is annexed : — 





From 



From 





Jolster. 



Arendal. 





Sp. Gr. 4-60. 



Sp. Gr. 4-73 to 4-76. 



Metallic acids, 



57-60 



53-64 



Yttria, 



25-09 



28-97 



Protox. of uranium, 



6-34 



7-58 



Protox. of cerium, 



3-14 



2-91 



Protox. of iron, . 



— 



2-60 



Lime, 



2-47 



— 



Magnesia, 



0-29 



— 



Water, . 



3-97 



4-04 



98-90 99-74 



When comparing the mineral here analysed with that from 

 Arendal by Scheerer we find that the sum of the metallic 

 acids, and the yttria, agree, but that Scheerer has no alumina, 

 lime, or magnesia, and considerably more water and protoxide 

 of uranium than I have found. 



