1879-1 
The Formation of Coal . 
681 
proceeding from the transformation of vasculose besides the 
ligneous fibres, which were not yet completely disorganised. 
This observation demonstrated the transformation cn the 
spot, and in the ligneous tissue itself, of a part of the wood 
into ulrnic acid. In this way M. Fremy was led to admit 
the fadt which appeared to predominate in his researches, 
that the vegetable matter was first changed into peat before 
producing coal, and that in this modification the disappear- 
ance of the organic tissues was owing to a kind of peaty 
fermentation. To confirm this hypothesis he found it 
necessary to prove that the ulmic acid could, like the bodies 
previously experimented upon, be transformed into coal. 
In consequence M. Fremy studied the transformation of 
three kinds of ulmic acid, and discovered that, after a 
calcination of 120 hours, the ulmic acid of the peat was 
converted into artificial coal, presenting the same compo- 
sition as the coal of Blanzy. 
Lastly, the mixtures of chlorophyllus, fatty bodies, and 
resins obtained from leaves by treating them with alcohol, 
when submitted to the same operation, — that is to say, 
heated under pressure for 150 hours, — produced a black, 
viscous, odorous substance, insoluble in alkalies, and pre- 
senting an evident analogy with natural bitumen. 
From these fadts M. Fremy draws the following con- 
clusions : — 
1. Coal is a substance which proceeds from the trans- 
formation of vegetable matter, but which no longer preserves 
its organic form. 
2. The vegetable marks which the coal presents are 
produced by it, as in schist or other mineral substances, 
and do not prove its organisation. This fuel is a bituminous 
and plastic matter, on which the external features of the 
vegetation are moulded. When a piece of coal presents on 
its surface, or within its interior, marks of vegetation, it is 
not to be thence inferred that the adjacent parts are neces- 
sarily the result of the alteration of the tissues which were 
covered by the membranes whose form has been preserved. 
3. The principal bodies contained in the vegetable cells, 
submitted to the double influence of heat and pressure, 
produce substances which present the properties and com- 
position of coal. 
4. The colouring, resinous, and fatty matters contained 
in the leaves are changed, by the adtion of heat and pressure, 
into substances which approach very nearly to natural 
bitumen. 
5. With regard to the ligneous tissues at the base of the 
