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On certain Varieties 
Art. III. On certain Varieties of Australian Coal . By 
Count Streleski. 
In the subjoined mincralogical description of some 
varieties of coal belonging to New South Wales, 
Tasmania, and Kerguelen’s Land, the specific gravity 
spoken of was ascertained by a Nicholson’s hydrostatic 
balance, capable of indicating distinctly differences equal 
to YffJstftb part of the weight in the balance. The chemical 
character of each species and variety was determined by 
two different analyses :— 
1st. By that of separating the organic substance under 
examination into its proximate constituents; and, 
2nd. By that of resolving it into its ultimate elements. 
In the first analytical process, one portion of the coal 
was deflagrated, and the earthy residue analysed in the 
usual way ; another portion was distilled, the vapours 
condensed, and the gases collected over water into a 
graduated receiver. Thus, the quantity of charcoal, bitu¬ 
men, earthy constituents, coke, naphtha, and coal-tar 
was arrived at; and a further determination was made of 
the amount of carbonic acid, sulphuretted hydrogen, and 
the two sorts of carburetted hydrogen contained in the 
gas receiver, by treating the gaseous mixture alternately 
with caustic potassas, carbonate of lead freshly preci¬ 
pitated from the acetate, and finally with chlorine gas, 
both in darkness and in the light. 
In the second process the elegant apparatus of Gay 
Lussac and Liebig was made use of, and the dcutoxide 
of copper employed as the oxydising agent. The carbon 
was estimated from the carbonic acid, the hydrogen from 
the water which the chloride of calcium absorbed in a 
separate tube. The oxygen was computed from the loss 7 
and the nitrogen (azote) from the subtraction of the car¬ 
bonic acid in the graduated receiver over mercury. 
