O. C. Farrington — Studies of Brazilian Favas. 357 





Analysis 













(mean of two) 





Ratic 



i 



Theory Ratio 



PO 



24-00 





•1671 

 •3737 

 •1087 



1-04 



2-32 



• 



-24-09 1 



-*■ 8 5 



Al ... 



38-12 



34-60 2 



BaO 



16-68 ) 





CaO 



3-14 [• 2 



1-94 



•0561 



1 



26-04 1 



CeO 



2-12) 





•0136 







H a O 



_ 15-94 





•8855 



5-49 



15-27 5 



100-00 100-00 



G = 3-10 



If, following the example of Hussak, from the analysis of 

 Fava No. 1 the percentages of Fe 2 3 and SiO„ be deducted and 

 the remainder be calculated to 100 per cent, the result with 

 ratios is as follows : 



P 2 6 .. 19-61 -138 -70 



A1 2 3 ._ 43-71 '429 2-19 



BaO 14-81 -097 ) 



CaO 1-94 034V-196 1-00 



Na 2 4-01 -065) 



H„0 15-92 -885 4-51 



100-00 



While these ratios are not quite identical to those of gorceix- 

 ite they seem to show a composition sufficiently near it to 

 warrant regarding this fava as composed of that mineral. 



The analysis of Fava No. 2 seems to show such a complex 

 composition that it is impossible to distinguish any primary 

 minerals. This fava was evidently a mixture. 



The analysis of Fava No. 3 reduced to ratios gave the fol- 

 lowing : 



Ratio 



1-52 



0-305 2-06 



0-148 1-00 



1-612 10-89 



PA-- 



31-62 



0-226 



A1.0, 



29-87 



0-292 



Pe,O t — »-- 



2-00 



0-013 



BaO 



20-61 



0-134 



CaO _ 



0-13 



0-002 



Na 2 



0-74 



0-012 



H 2 



13-67 



1-519 



F 



1-77 



0-093 



Moisture 



0-26 





100-67 



It is evident that this fava is too high in phosphoric acid and 

 fluorine to be referred to gorceixite. In a general way its 



