19G 
On certain Varieties 
Geological situation .—It occurs in alluvial land in 
detached masses; sometimes these masses are compressed, 
forming beds, of which one part is carbonised, while the 
other remains in the state of wood. The valley of the 
tributaries of the Derwent, and that of the tributaries of 
the Tamar, abound in lignites. 
RECHERCHE RAY, TASMANIA. 
Slaty Glance Coal. ( Jamieson .) 
(Syn.—A nthracite, Brongniart.) 
External character .—Colour iron black, texture com¬ 
pact, fracture slaty, easily frangible ; specific gra¬ 
vity 1*46. 
Chemical character .—Burns with difficulty, yields 
little or no flame, nor any bituminous odour: its prox¬ 
imate constituents are,— 
Charcoal . 74*4 
Alumine . 15*0 
Silica. 3*0 
Peroxide of iron. 2*0 
Water . 5 6 
Applied to the production of gas, one pound gives 
1100 cubic inches of very faintly illuminating gas : no 
tar or coke were detected in this coal. 
The gaseous mixture, treated by re-agents, contains in 
each 100 volumes— 
Sulphuretted hydrogen. 
. 8- 
Carbonic acid. 
. 20- 
Olefiant gas. 
. oo- 
Carburetted hydrogen . 
Other inflammatory gas ... 
. 52- 
Analysed with peroxide of copper, the quantities of its 
ultimate elements, after the .earthy 
matter has been 
abstracted, will stand in the following 
proportion:— 
Carbon .. 
... 75-15 
