AGRICULTURAL TEXT-BOOK. 37 



117. VI. Marl from Bordentown, (A,) and from Squankum, (B,) 

 New Jersey . (Dr. AntiscU . ) 



A. B. 



Silicates, insoluble in hydrocholoric acid, - - 68.66 76.00 



Alumina, - - 7.00 5.00 



Lime, - - 1.40 2.85 



Magnesia, - - - 0.38 0.18 



Peroxide of iron, - ... 9.00 3.20 



Potash, - - . . . 3.70 5.80 



Soda, - . 0.30 1.10 



Chlorine, ... . 0.20 0.40 



Sulphuric acid. . 1.30 0.90 



Phosphoric acid, - - 0.23 0.46 



Carbonic acid, - - - 1.84 



Moisture, - 6.46 2.00 



Sulphur, combined with iron, - - 1.32 0.27 



100.00 100.00 



118. VII. Green Sand Marl, Shrewsbury, Monmouth county, New 

 Jersey; two varieties. (H. Wurtz.) 



A. B. 



Silica, - . 48.24 47.83 



Alumina and oxide of iron, &amp;gt; - - 32.89 34.98 



Potash, - - 6.38 4.94 



Magnesia, - . - -2.60 



Hygroscopic water, - - 4.81 &amp;gt; 



Combined water, - -5.69$ 



100.61 99.25 



119. VIII. Red Marl, Springfield, Mass. (Dr. C. T. Jackson.&quot;) 



Water, - 8.5 



Silex, - . 51.3 



Alumina, - . - 16.0 



Peroxide of iron, with a trace of manganese, ... 20.0 



Lime, - - - 2.8 



Magnesia, - - - -1.0 



99.6 



