CLAYS OF NEW YORK 807 



good ri suits wlieai mixed with, otlier clays or with artificial fluxes. 

 Analyses x ^ this material are given beyond. 



The f oUo'^v ing analyses made by the Missouri geological survey 

 gives the composition of the clay. 



Silica 56.75 



Alumina 15 . 47 



Combined water 8 . 8 Y 



Moisture 37 



Protoxid of iron 5.73 



Protoxid of manganese tr . 



Lime 5.78 



Magnesia 3.32 



AlkaHs 3.25 



Total 99.54 



Another analysis made by H. H. Grififen (Clay luorker, 28: 

 178) gives: 



Silica 17.02 



Alumina , 14.80 



Ferric oxid 5.85 



Manganic oxid .14 



Lime 5.70 



Magnesia 2 . 48 



Potash 3.23 



Soda 1.07 



Phosphoric acid .15 



Water 5.18 



Moisture and carbonic acid 4.94 



Sand 38.58 



Total 99.14 



Tests made by the Missouri geological survey showed that this 

 clay shrunk 6^ when air dried and 8/^ when vitrified, giving a 



