178 INORGANIC CONSTITUENTS OF THE 
Bottom Coal. 
Percentage of ash, 22°88 ; ash very dense, grey coloured. 
Analysis— 
Alkalies... a ..- 0°85 Soluble in water. 
Lime. 98 | Soluble in ei 
Magnesia ... a — 36 
Phosphoric oxide ... ae “44 
Alumina, --- acs ve 119 Insoluble in acid 
Ferric oxide... on ... traces. 49 
Silica ae x 68°63 
100-23 
The ratios of the insoluble to soluble alumina in these ashes 
Top coal 1 05 
Torbanite Tee ate =e ae 
Bottom coal ... =, a ee 
of the upper coal —— in this respect a great 
difference — all the others ined, whilst the other two are 
ured exactly the same result as before. The ratio with a 
increased solubility would, however, only be 1 : 1, which 
shows a meine difference from all the other coals. 
imilarity in composition of the ashes of the t torbanite t0 
The 
those of the various coals, including the presence of @ 2 a" 
quanti of phosphoric oes does not a ar to = 
ai 2 the ‘nom 
7S 
prot of torbanite the ash ae amounts to ‘10 per cent., 0 ak 
7 per cent. is silica, and we can scarcely think that the 2 cme 
of alumina would suffice for the condensation of so many aa 
own weight of bitumen. It seems probable, rather, th ir 
mineral has been formed like coal deen plants either of @ pe 
kind or under oat conditions. That the conditions, fe 
tion have something to do with it is borne out by the of the 
of Mr. Fell, who has had much to do with the working 
1 Chem. News, xxxi, 16. we 
