426 Dr. Genth’s Contributions to Mineralogy. 
that the Bastnaes mineral is the same substance and Hisinger’s 
formula consequently correct. 
hope to be able hereafter to settle the doubts which exist on 
this point. - 
Prof. C. U. Shepard states (Report on the Canton Mine) that 
he has observed this mineral at the Canton Mine, he does not in- 
form us, however, what induces him to take the pink-colored 
erystals for lanthanite.. I have not been able to procure a speci- 
men of it and also did not succeed in finding any indications of 
minerals containing cerium or lanthana, from the decomposition 
of which the lanthanite could have been formed. 
15. Bismuthite. 
T have made an examination of the bismuthite from the Brew- 
percentage of the brown ochreous residue,*insoluble in dilute 
nitric acid. 
_ Lhaye analyzed a pale variety (I) and a darker one (II), and 
made two analyses of each, one by treating the finely powdered 
mineral with dilute nitric acid (a), the other by digestion with 
strong chlorhydric acid (8), by which everything, except the 
silicic acid, is dissolved. : 
e quantities of lime and magnesia were found to be very 
small and have not been determined 
The following are the results: 
lL 
Il. 
ss ee Oo 
a a 5 
Insoluble in dil. NOs, 25°42 ae 28:16 = 
ining water, (159) (2°62) ela 
Teroxyd of bismuth, 64°72 64-24 62:15 6145 
Tellurous acid, ees 0-05 pclae 0" 
xyd of iron, 0-91 6-64 ° 1:30 11-20 
O74 118 0°68 “wie 
Silicic acid, 0-48 1778 — 
Carbonic acid, Sat 08 — 512 
Water, ins 3-94 anil 541 
98°91 99°32 
Deducting the amount of water, which the residue insoluble in 
nitric acid contains, from the whole quantity given in the red : 
_ses (2) we obtain pretty correctly (though somewhat too high) the 
amount of water ined in the pure bismuthite. We wow. 
* ™ 
- oe ge gees ee 
