On the Chemical Composition qf Clay-slate. 259 



[ 1. Analysis of Clay- Slate as a whole. 



From Goslar. 



Silica, 60.03 



Alumina, 14.91 



Oxide of Iron, 8.94 



Magnesia, 4.22 



Lime, 2.08 



Oxide of Copper, .... 0.28 



Water and Carbon, . . . 5.C7 



Potash and Loss, .... 3.87 



100.00 



100.00 



lOO.CO 



2. Analysis of the Component Portions qf Clayslate. 



A. By treatment with acids there was decomf osed .•— 



28.98 p. cent. 26.46. 23.61. 



v^hich consisted of 



Silica, 23.01 22.39 22.16 



Alumina, 16.19 1935 21.48 



Oxide of Iron, 20.19 27.61 27.57 



Magnesia, 11.60 7.0 &29 



Lime, 4.63 2.42 1.26 



Potash, 1.96 2.37 1-65 



Water, Carbonic Acid, & loss, 22.32 18.86 17,59 



100.00 



100.00 



100.00 



B. After treatment with acids there remained undecomposed :— 

 71.02 p. cent. 73.54 76.59 

 which consisted of 



Silica, . . 

 Alumina, 

 Oxide of Iron, 

 Magnesia, . 

 Lime,- 



Oxide of Copper, 

 Potash, . . . 

 Carbon and Loss, 



74.98 

 14.32 

 4.94 

 1.48 

 0.78 

 0.36 

 3.38 

 0.26 



Qu?n>ity 



of 

 Ox>g3n. 



38.95 



6.68 



1.37 



0.57 



0.20 



0.07 

 0.57 



77.06 

 15.99 

 1.53 

 0.57 

 0.33 

 0.19 

 3.94 

 0.39 



QuanHty 



Of 

 Oxygen. 



40.03 

 7.46 

 0.46 

 0.12 

 0.09 

 0.03 

 0.66 



77.68 

 15.74 

 1.22 

 1.32 

 0.60 

 0.40 

 3.14 



Quantity 



of 



Oxygen. 



40.35 

 7.35 

 0.37 

 0.51 

 0.46 

 0.08 

 3 



100.00 ... 100.00 



VOL. XXIII. NO. XLVf. — OCTOBEK 1837. 



