FRANCIS ON COAL DEPOSITS. 
131 
The ultimate analysis showed the following composition : — 
Carbon 
Dried Coal. 
69-643 
Undried Coal. 
67-090 
Hydrogen . . . 
5-535 
5-332 
Nitrogen 
2-539 
2-446 
Oxygen . . . 
10-577 
10-193 
Sulphur . . . 
3-954 
8-805 
Ash 
7-752 
7-468 
Water 
o-ooo 
3-666 
100-000 
100-000 
Calorific equivalents of carbon and hydrogen in 100 parts : — 
i. Dried Coal 707259 heat units. 
ii. Undried Coal 680448 „ „ 
Estimated practical calorific effect, based on the results of the 
Admiralty inquiry into heating power of coals : — 
Quantity of feed water at 100°C converted into 
steam by 100 lbs. of undried coal 
Purified illuminating gas yielded by one ton of coal 
measured at 28°C ... 
Ammonia equal to nitrogen in one ton of coal 
Equal to ammonium sulphate 
Sulphur present as pyrites in coal 
Sulphur present as calcium sulphate ... 
Total sulphur ... 
Sulphur dioxide gas produced by burning one ton 
of coal 
= 750 lbs. 
5613 cub. feet. 
69-06 lbs. 
268-10 „ 
3-912 per cent. 
0-048 
3-960 
55 
55 
175-28 lbs. 
The foregoing results show that this coal is allied to the 
class of brown coals described by Messrs. Wall and Sawkins 
as of middle tertiary formation ( Geolog . Rep. Trinidad). 
Although inferior to coal of an earlier era, it will doubtless 
form a valuable fuel. It approaches perfect coal perhaps 
more closely than any of the Trinidad specimens yet 
examined, — a conclusion which has been arrived at by com- 
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