1905) TRANSEAU—BOGS OF THE HURON RIVER VALLEY 369 
of ammonia. This is at once attacked by the nitrifying bacteria, 
and changed successively to the form of a nitrite and a nitrate. The 
two latter changes again involve the addition of oxygen. 
If we consider only the temperatures occurring in nature, we may 
say that these activities increase regularly with the temperature. As’ 
to water conditions, it has been shown that in air-dry soil eremacausis 
is practically wanting, and that when the soil is filled with water it is 
reduced toa minimum. Between these two extremes lies an optimum 
at which there is sufficient moisture for the life of the organisms, and 
yet not enough to interfere with the diffusion of oxygen. An acid 
condition impedes, and a slight alkalinity favors, the production of 
both the carbon and the nitrogen compounds. 
Eremacausis is then essentially a process of oxidation, brought 
about by lower organisms, whose activities are favored by a high 
‘emperature, a slightly alkaline medium, and free access to the air. 
Its products are simple compounds which may furnish food materials 
for the higher plants living on the substratum in which they are formed. 
By putrefaction is meant that process of disintegration which 
occurs when organic matter decays in the absence of oxygen. Here 
again Organisms are involved, but they belong for the most part to 
the anaerobes, and are wholly forms of bacteria. The process 1S 
“sentially one of reduction. 4 
Carbon dioxid is again the principal gaseous product, but its 
relative amount is greatly reduced. Along with it CH, H, HS, 
HP, N,O, and N are produced in small quantities. In the manu- 
% of the carbon dioxid the oxygen is not only derived from the 
“rganic matter, but also from nitrous oxid, nitrites and nitrates which 
may be present. In the decomposition of cellulose, carbon dioxid 
~ methane result from the hydrolysis of the cellulose molecule. 
of is at first break up into amido-acids, nitrogenous ee 
oS ame series, and other little-known bodies. If t si ee 
chin Continues, the amido-acids in turn form ammo 
Pounds of the fatty-acid series. The latter substances may 
D further disintegrate to carbon dioxid, hydrogen, and methane. 
"ra upon the stage in the progress of decomposition, We may 
ti complex organic compounds, organic acids, and their salts, or 
Paratively simple substances. 
