1908.| Agents in the Oxidation of Amorphous Carbon. 257 
can be attained. This is well exemplified in the case of peat, where the 
vegetable débris in a wet and sodden condition is excluded from a sufficient 
supply of oxygen, and therefore the oxidising organisms are unable to carry 
on their work, any further changes must be due to anaerobic forms, and the 
decay is necessarily incomplete. In a similar manner it may be supposed 
that the large deposits which form the basis of coal are due to plant remains 
which, in the first instance, were preciuded from complete oxidation owing to 
their submerged situation, where vegetable matter could only be acted upon 
by anaerobic bacteria. 
In this connection, Renault’s(10) researches upon Fossil Bacteria are of 
great interest. He brings forward evidence to show that bacteria have 
existed since Devonian times, and have played a considerable part in the 
destruction and decomposition of vegetable and animal tissues from this remote 
period. Microscopic sections have furnished remarkable proof of their 
presence inthe upper Jurassic beds, in the Permian Strata, the Upper, Middle, 
and Lower Coal Measures, in the Carboniferous Limestone, and in the 
Devonian, and these illustrate in a remarkable manner the destructive action 
of numerous micro-organisms upon organic remains imbedded in these 
formations. Renault states that in many cases the minutest details have been 
preserved in such perfection that it has been possible to detect the bacteria 
often more easily in the fossilised than in the living state. All stages in the 
disintegration of the cell-tissues are clearly exhibited, and it is proved that 
the rdle of these micro-organisms has been identical with that which they 
perform in the present day. 
According to Renault, “If in the formation of coal there are two distinct 
phases, one, purely chemical, which has brought the remains of plants to a 
certain composition answering roughly, in the case of ‘houille de bois pur,’ to 
the formula CyH30, the second, simply mechanical, due to a slow compression 
in a permeable medium, the first of these phases can be attributed to a 
bacterial fermentation developed in the marshes, ponds, deltas, and arrested 
by periodic floods, carrying away a portion of the macerated plants and 
transporting them into lakes and seas, where maceration became impossible.” 
In later times heat and pressure would convert this partially decayed 
vegetable déiris into coal. The decay bas, however, only been arrested, and, 
lke peat, when a sufficiency of oxygen is available and the necessary 
conditions for the life of aerobic organisms are presented, the decomposition 
proceeds, the elements are reduced to their simplest compounds, and the 
carbon is once more liberated in the form of CO, to play its 7d/e in the life 
eycle, 
Coal and peat are shown to be subject to the same laws as other organic 
