256 
cation of heat — made from specimens cleanly separated 
from the base : — 
Percentage Composition of Vermiculite. 
Before Ignition, After Ignition. 
Ferric Oxide .. .i 22-78 (15-95 Iron) .. 26-00 (18-20 Iron) 
Manganic Oxide . . 1*50 , . . , . . 1-72 
Alumina .. .. 0-24 7-12 
Titanic Oxide.. .. 1-15 1-32 
Lime 2-19 2-50 
Magnesia .. 11-83 13-60 
Phosphoric Acid .. C*49 0-56 
Soda 3-19 3-64 
Insoluble Eesidue* ..38-23 43-64 
"Water, comhined . . 12*10 . , . . . . None 
lOOCO 100-00 
* Percentage of Insoluble Kksidue. 
Silica .. 85-00 
Alumina .. 10-20 
Soda .. .. .. 4-80 
Magnesia . . • • . . Trace 
Sulphuric Acid . » . , Trace 
10000 
The examples I have here vary in size from ^L- to -/^ of 
an inch. When carefully detached from the matrix and 
placed on a platinum dish exposed to the flame of a spirit 
lamp or Bunsen's burner, the water in combination is driven 
off, and each piece of the mineral seen to exfoliate, lengthen, 
and twist about like a worm. Some attaining a length off 
of an inch without any decrease in diameter. The colour is 
now of a rich reddish brown, with a strong metallic lustre, 
and a slight pressure will separate the scale-like discs, which 
if crushed in the palm of the hand and well rubbed on the 
skin, leaves a stain with a dark brown bronze-like lustre. 
Since the discovery of these boulders of Vermiculite 
Granite — as I propose to call it — I have met with examples 
