35© 



University of California. 



[Vol. i. 





I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 







A 1 ( \ 



re^O-i 



FeO 



CaO 



MgO 



Na,0 



K 2 



H.O 



4/-»5 



13- 2 4t 

 2.74 

 2.65 



14- 36! 

 5 68 

 3-72 

 5.25 

 2.74 

 2.42 



48.03 



!5-34 

 7-39 



3- 34 

 13-63 



4- 65 

 1.41 

 3.68 



49- r 5 

 !3-37 

 6.65 

 5-88 

 i°-73 



5- 3° 

 V08 



6- 55 



48-59 

 19-5° 



4.38 



4-56 



9.12 



3.12 

 2.15 



6.27 



. 12 



2.04 



■ 15 



trace 



48.54 

 14.86 

 4.17 

 4.82 

 11.89 



5- 75 

 2.71 



6- 45 

 .16 



47-63 

 15. u 



O.O7 



3-34 

 i5-7o 

 4.66 

 1. 18 

 3-8 7 

 1.61 

 1.65 

 ■05 

 .06 



47-8 

 20.1 

 6.7 



.8 



5-4 

 i.i 



5-5 



7-i 



2.4 Ug- 



p 2 o 5 



1.83 

 .02 

 trace 





S0 3 







■4 



(Baryta .8) 

 • 7 

 •5 



CI 









Ti0 2 







.21 

 1. 18 



MnO 



























Total 



100.65 



100.12 1 100.71 



100.08 



100.92 



100.93 



99-3 



Sp. g. 



2.879 2.76 



2.65 



2.74 



* Mean of 47.91 and 47.79. 

 t Mean of 13.33 ar >d 13.16. 

 X Mean of 14.54 ar >d I 4- I 9- 



With very moderate digestion 28.14 per cent, of the rock dis- 

 solves in hydrochloric acid. 



An attempt was made to estimate the proportions in which the 

 constituent minerals are present in the rock, and the following re- 

 sults were obtained: — 



/ vEgerine 5.60 



jr~* ' \ Diopside 27.92 



Agenne-aug.te.. Hiddenbergite 



( Augite 5.15 



Orthoclase 



Nepheline 



Apatite 



Biotite 



Titanite 



Water 



Proportion 

 of 



Minerals. 



48.17 



20.90 

 19.62 

 5.8l 

 2.0O 

 I. OO 

 2 70 



IOO 20 



Specific 

 Gravity. 



3-299 



2.56 d 

 2.60 a 



3-25 d 

 2.90 a 

 3-50 a 

 1. 00 



rf=determined 

 a=assumed 



Product. 



158.91 



53-51 

 51.01 

 18.88 

 5-74 

 3-5o 

 2.70 



294-35 



The specific gravity of the rock as thus estimated should be 

 2.93, while the actual specific gravity is 2.879. We have thus a 

 check upon the approximate estimate of the proportion of the dif- 

 ferent minerals present. 



