JULIEN, DETERMINATION OF MINERAL CONSTITUTION 143 



"Saponite." 



From Kinneli, ^tr'.., Scotland. Average of thirteen analyses by Heddle. 

 "A hydrous silicate of magnesium and aluminum, but the material is 

 amorphous and probably always impure" (Dana). 



"Pilolite." 



Mountain cork or leather, from Scotland. Average of seven analyses 

 by Heddle, with the formula: 4MgO. AIA. 10 SiOg. I5H2O. 



