Sottas—On Pucksia Mac Henryi. 303 
Geologie, Bd. 11., p. 443). His results are shown in column II. 
As might naturally be expected in the case of a rock so largely 
made up of mica, the composition of the slate does not differ 
greatly from that of the constituent mica, as will be seen by 
reference to the column III., which gives the composition of a 
muscovite mica also analysed by Schwager (Hintze, Handbuch der 
Mineralogie, p. 6381). 
1 II. III. 
Oey) Wo BO54 ee. 852504 45 cy Sorel 
POE BE. Os, 2) S8:897 ¢o 40 8Oe 002 oe a, 80,04 
SOMME Fores GRE ait, CWS ao ay Re 
MeO sy IOS 1 et ae Oca ees 8s 
POMP MTs 17) SOOM hk LN ASED ui Sp 4d 
OMe shi .S6149 Bier tole uf 14-00 
ECM in fis vari BhT SO kay oa Coro lwnues, Face 
HOP eit or nC TAO: (raud asf MaKe af tts ies 
100-950 100-02 99:62 
1 [Including 1°51 per cent. of TiOz. 
2 Including a small quantity of FeO. 
3 Determined by loss on ignition. 
