196 Jr. S, Ford — Chemical Composition of Axinite. 



rous iron was determined by the method described by Pratt.* 

 "Water was estimated directly by a method devised by Prof. 

 Penh'eld which will be described by him in a future num- 

 ber of this Journal. Boron was estimated by the Gooch 

 methodf with the modifications suggested by Penfield and 

 Sperry^ and by Penfield and Foote.§ It was found neces- 

 sary to add a little quartz to the first sodium carbonate fusion 

 and to repeat the fusion of the residues at least twice in order 

 to completely extract the boron. The large amount of calcium 

 in the mineral seems to hold the boron quite tenaciously and 

 only by observing the above precautions was it possible to 

 extract all the boron and obtain correct determinations. A 

 careful test was made for alkalies with but a negative result. 



Results of Analyses. 



Analysis No. I. — Axinite from Bourg d'Oisans. 

 gravity = 3*287. 



Specific 



II. 



III. Average. Eatio. 



Si0 2 42-73 



42-86 42-76 



42-78 



•713 -=- 



•089=8-00 



B 2 3 5-84 



6-40 



6-12 



•087 



= 0-97 



A1 2 3 18-02 

 Fe 2 3 -94 



17-67 17-32 

 •90 1-15 



17-67 

 •99 



•006 \ Ui 



= 1-99 



FeO 5-94 



6-01 6-12 



6-02 



•083"] 





MnO 3-08 



2-90 



2-99 



•042 | 





CaO 20-13 



20-19 



20-16 



•360 ^"622 • 



= 6-99 



MgO 2-51 



2'32 



2-41 



•060 | 





H 2 1-37 



1-44 



1-40 



•077 J 







100-54 





Analysis JSTo. II. — Axinite 

 gravity = 3*028. 



from 



Obira, Japan. 



Specific 







Ratio. 







SiO ._. 



41-80 



•696 

 •080 

 •166 

 •007 

 •039 * 



■+■ -087 

 I -173 



= 8-00 



BO,.. 



5*61 



== 0-92 



-■-'2 3 



Al . 



17-15 





Ai 2 3 



Fe O .. 



111 



= 1*99 



2 3 



FeO ... 



2-84 





MnO... 



10-71 



•150 







CaO ... 



19-51 



•348 



► -609 



= 7-00 



MgO._. 

 H O ... 



-21 



1-22 



•005 



•067 







-"•j^ 









100-16 







* This Journal (3), xlviii, 

 \ Amer. Chem. Jour., ix 

 i This Journal (3), xxxiv 

 § Ibid. (4), vii, 97, 1889. 



149, 1894. 

 23. 



220, 1887. 





