16 



THE GASES IN ROCKS. 



TABLE 8 Continued. 



iNo. 32. Analysis: SiOo, 38.05; ALO 3 , 24.73; FeO, 5.65; Fe.,0, 6.08; CaO, 1.25; MgO, 11.58; Na0, 2.54; K 2 0, 1.94 ; 

 HoO, 7.53 ; C0, 0.93 ; 100.28. (R. B. Riggs, BulL62, p. 76.) 



- Probably only a small part of gas was really present in the gaseous condition, the analysis being made to show 

 what a bituminous shale may yield. 



3 A metamorphosed slate of the Grenville series. Reference : Am. Jour. Sci., vol. 50, p. 58. Described as a fine- 

 grained garnetiferous sillimanite gneiss containing much quartz and orthoclase. Graphite and pyrite also present, 

 causing the gneiss to weather to a very rusty color. Analysis by N. N. Evans, of McGill University : No. 43. SiO, 

 61.96 ; TiOo, 1.66 ; A1..O 3 , 19.73 ; Fe.,0 3 aud FeO, 4.60 ; FeS, 4.33 ; MnO, trace ; CaO, 0.35 ; MgO, 1.81 ; Na 8 O, 0.79 ; K0, 

 2.50 ; H 2 O "(ignition^ 1.82 ; 99.55. 



