252 8. L. Penfield — Composition of Amrrh-an Monazite. 



mined, the rest not being carried out in duplicate owing to 

 me at my disposal. 



1. Portland, Ct. Sp. Gr. 5 -2 0-5 25. 



2. Burke Co., North Carolina. Sp. 



Hence, (Ce, La, Di) a 3 : P 2 B = 1-00 : 1-07 = 1 : 1, and 

 ThO, : SiO, = 1-00 : 0*88 = 1:1 

 A glance at the ratios calculated for these analyses will show- 

 that in every case the ratio of (Ce, La, Di),0, : P a 6 = 1:1. 



metals, I!J\(V. It may be added that Uammelsberg* has 

 I moiiaxite, from Aivndal. which con- 

 tained nothoria. and aureed with this formula. It will also he 

 seen that each analysis has a Horded a certain amount of thoria 

 and silica, and that these also are present in the ratio of 1 : 1, 

 or that required by a normal thorium silicate. When it is 

 considered that oxide of thorium is widely different in its 



