Knopf 'and Schaller — Two New Boron Minerals. 32T 



Analyses of Hulsite. 

 12 3 Average. 



FeO 33-27 33-27 



MgO 10-17 .-.- 10-17 



Fe„0 3 __ 17-83 



Total iron as Fe o 3 .. 54-40 54-20 



H„0 1 1-24 1.81 (calc.) 



B 2 O s -. 27-42 (calc.) 



Insol. 10-00 10-00 



100-00 



Ratio Av. Anal. 



5& ■::::::::::::: 4S| ™ ■> 



Fe 2 3 -108 1-05 1 



H 3 0. -101 -98 1 



B.,0 3 -392 3-83 4 



The formula for hulsite then becomes 7(Fe,Mg)O.Fe 2 3 .H 2 0. 

 4B 2 3 . 



The values given for B 2 3 and water are calculated from 

 the figures obtained from the magnetite-hulsite mixture as 

 given beyond. The direct water determination, 1-24 per cent, 

 is of no exact value on account of the small quantity of water 

 weighed, being in this case only 2 - 3 mg , so that more reliance 

 is placed on the figures obtained from the hulsite-magnetite 

 mixture, from which the value 1*81 per cent is calculated. As 

 above stated, the determinations on this sample were made on 

 powder of <C60> 100 mesh. Considerably more material of 

 the magnetite-hulsite mixture was available for chemical 

 analysis and the following results were obtained, about 1/4 

 gram substance being used for a determination: 



Analyses of Magnetite-Hulsite. 



1 2 3 4 5 Average. 



FeO 34-48 3435 34-44 



MgO 8-60 8-83 8-36 8"12 8-48 



Fe o 3 _ ... ... ... 27-64 



Total iron as Fe„0 3 66-24 67*08 65-70 65-12 65-32 



H 2 ... 1-63 1-68 1-66 



B 3 25-27 _'__■_ 25-27 



Insol. 2-25 1-97 2"24 2-48 2*24 



99-73 



The total iron determinations given were all made volu- 

 metrically, as the gravimetric determinations gave very varied 



