1995] TRANSEAU—BOGS OF THE HURON RIVER VALLEY 375 
hydrates. These bodies not only occur in nature, but may be arti- 
ficially produced by the action of strong acids on starch, sugar, and 
cellulose. The relation of nitrogen to these bodies is still unknown. 
Principally on the basis of color and solubility in alkalies and acids, 
there are several substances distinguished. Ulmin and ulmic acid 
are brown, and are early products of decomposition. Humin and 
humic acid are black, and occur more abundantly where eremacausis 
has been active for a long time. Crenic and apocrenic acids appear 
to be further oxidation products; the former is colorless, and the 
latter varies from yellow to brown. MAvERr believes these bodies to 
be organic nitrogen compounds (36), and on this basis SrOCKBRIDGE 
(50, p. 135) explains the insolubility of peat soils and the presence of 
the unavailable nitrogen in peat. Beside these substances xylic, 
saccharic, and glucinic acids have been recognized. Although great 
advances have been made in soil chemics, it seems strange that the 
only suggestion of formula for these substances was made by MULDER 
in 1861 (38). 
Humic acid forms water-soluble compounds, with the alkalies, and 
to these are due largely the brown colors of the bog waters. The color 
may be produced by the presence of free humic acid. With the 
alkaline earths humic acid forms insoluble or difficultly soluble com- 
pounds. Hence there is slight chance of lime and magnesia pene- 
trating from the surrounding soil into the peat deposits. 
During the changes which the plant material undergoes in the 
Process of peat-making there are alterations in the relative amounts 
of volatile hydrocarbons, fixed carbon, and ash—using these terms 
“S$ In ordinary coal analyses. 
qh Eriopho dra | Tamarack a 
ee ‘ 
rum Stems | Sphagnum | rum ome a. Zone Peat uck 
‘and Leaves Peat : 
Slatile combustible, 68> 
V 45-7 
: 62.0 54.0 53:0 
Hoag gat, 21.0 a 21.8 22.9 23-4 wisi 
TO eee 3.8 4.5 7.4 13.8 13.6 sige 
a ° 10.6 8.8 9-3 10.0 ee 
7- : fe 
The Proportion of volatile combustible matter decreases regularly 
as the humification proceeds. The ash regularly increases, while the 
air-dry water content shows but slight modification. : 
(To be continued.) 
