192 
On certain Varieties 
WESTERN PORT, NEW SOUTH WALES. 
Slate Coal. 
External character .—Its colour is black, lustre resin¬ 
ous, glistening, structure somewhat slaty, fragments are 
indeterminate and angular, it is brittle and light; spe¬ 
cific gravity 1*38. 
Chemical character .—It burns with a bright flame, 
swells and agglutinates ; its proximate constituents are— 
Charcoal. 54 
Bitumen. 35 
Earthy matter . 11 
Applied to the production of gas, 
1 lb.=2 cubic feet of illuminating gas. 
The gaseous mixture, examined and treated by re¬ 
agents, contains, in each 100 volumes— 
Sulphuretted hydrogen. 11 
Carbonic acid . 10 
Olefiant gas. 20 
Carburetted hydrogen. 10 
Other inflammatory gas. 49 
Every 100 parts in weight of coal yields, 
Coke . 65 
Coal tar. 20 
Analysed with the peroxide of copper, the quantities of 
its ultimate elements, abstracted from earthy matter, will 
stand in the following proportion :— 
Carbon. 70*1 
Hydrogen. 16*2 
Oxygen. 3*7 
Nitrogen. 10’0 
Geological situation .—It occurs in beds of the car¬ 
boniferous series of sandstone, indurated clay, and clay. 
Slate and coal are alternating with each other, except 
that the roof and the floor of the coal is invariably fine 
brick clay. 
