TCHORNOZEM OR BLACK EARTH OF RUSSIA. 
561 
peculiar, loamy permeable clay, which, with the aid of its combined nitrogen, 
renders this soil so eminently productive. 
When w^e speculate on the probable origin of the tchornozem, the first im- 
pression might be (what is indeed the prevalent opinion in Russia), — that it is the 
humus arising from decayed forests or vegetables during the present period. But 
we entirely dissent from this opinion ; judging from the uniform nature of the soil, 
its distribution at all levels, and also that in no part of the empire does it ever 
contain a trace of trees, roots, or vegetable fibre. It is in vain to say, that such 
terrestrial vegetables may have been entirely decomposed ; for in the denuda- 
tions which expose 15 to 20 feet of this matter, some remains of the plants w y ould 
surely be found in the lowest parts of the solid earth, just as we find roots and 
branches of oak, pine, birch, and hazel in our peat bogs. We would also add, 
that if the black earth had been produced by the decay of trees, traces of it 
would certainly be found in northern Russia, where forests have so long existed. 
But in no part of northern Russia (large portions of which have been cleared and 
converted into arable land) is there a vestige of black earth, whilst it specially 
abounds to the south of a certain line, or exactly in those extensive and steppe-like 
undulations, which have been void of trees throughout all known time. 
Recognizing the great extent and uniformity of the tchornozem at various ele- 
vations, Mr. Strangways indicates its existence at intervals from the Volga to the 
tracts near the mouth of the Danube, and even to Podolia and East Gallicia 1 . He 
further remarks, that in Podolia it yields a large quantity of nitre, and that though 
more sparingly distributed in the lower steppes of the Caucasus than in the higher 
plateaux, this mould is found to the east of the Sea of Azof, i. e. between that sea 
and the Caspian, and chiefly near the mouths of the rivers Kuban and Terek and 
around the salt marshes, near the edges of which the tchornozem is covered with a 
saline efflorescence having a disagreeable odour. 
Now if, from these facts, it be impossible to adopt the hypothesis of simple ter- 
restrial origin, and that we consider it a subaqueous deposit, with what known 
accumulation shall we compare the black earth ? Is it to be placed in parallel with 
the finely levigated silt which the Germans call loss, or with the upper diluvial 
1 MS. read before the Geol. Soc. of London, anno 1824. In his valuable observations, Mr. S Gang- 
ways, •whose botanical knowledge is well known, also repudiates the prevalent idea, that this black mould 
can have been derived from the decomposition of forests. “ The character of the black mould being every, 
where the same, it is difficult (he says) to imagine that the same plants ever grew in so many situations 
with such opposite aspects, on such different soils and over so vast a surface. 
