O. D. Allen—Hatchettolite and Samarskite. ee 
a Q) (2) See ratio. 
olumbic acid ._ .__- ee LLL ‘ a0. - 2754.1. 
Tantalic acid__.__.. odie Co eas 80 | 18°60 0838 venus 
Stannic acid _.___.. ate 0°08 0005 } 
wee 14°52 14°45 *1896 
Cerium oxides*_____ 4°10 4°24 0382 +4430 
Uraninm oxide (VO,0) 12°63 12°46 0433 
Manganese protoxide 0 0°75 0106 
Tron Be. 10°60 10°90 *1513 
Se ee ae 0°55 160 | 
Wate ie lee the Be 
100°35 
rated s 
expelled by ignition was collected by a calcium chloride 
tube. 0° gram of the very finely pulverized mineral was com- 
confirmed the first result. It may therefore be concluded that 
no material amount of uranium is present in the lower state of 
oxidation (UO,). The relative number of atoms of each ele- 
ment present is calculated from No. 2, uranium being assum 
to exist as UO, or an oxide (UO,0) of the bivalent radical 
O, which it is reasonable to suppose acts as a basic radical 
With tantalie and columbic acids, as it does with phosphoric 
and arsenic acids in several natural compounds. R: R is then 
0 : 3592=1-286 : 1=4-94:4 closely approximating 5:4 re- 
* 1: ok 3 eae 
quired by the formula R,R,O,+R,R,0,. | 
In chemical constitution this samarskite appears to approach 
Fergusonite being next to this mineral the most basic of the 
natural columbates and tantalates. The formula of Fergusonite, 
d uced by Rammelsberg from a large number of analyses, is 
R,(Cb, 13),0%. 
* The ato . ae eS Bas hea as ee ee ee + £ 
element is readil shown by spectroscopic examination of a solution. Only a 
the ute quantity ot cerium is -paubel ‘tis swidaenies or absence of other elements of 
Cerium group was not ascertained. : 
t Dr. Smith's analysis, contained in the paper already cited, gave 55°13 colum- 
t Proceedings of the Boston Society of Natural History, vol., xvii, 424, 1875. 
See also this volume, p. 71. ee 
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