118 PROBABLE EXTENSION OF COAL BENEATH THE CHALK 
but also from borings at numerous points, as well as from the analysis of the coal- 
seams discovered. 
To the east, however, of the north and south parallel in which the Kalmiuss 
flows, the carbonaceous matter increases considerably with the augmentation of 
masses of shale with limestone ; and we think that the whole of the ridges south of 
Bachmuth, and on the east bank of the Toretz (the mines of Jeleznoe (p. 103) afford 
a good illustration), are well worthy of being largely excavated and carefully 
examined ; for from the elevation of the hills it is evident, that in many of these 
places the mines could be drained by adits, at a small expense. In their exten- 
sion to the south-east, the strata, becoming highly arenaceous and argillaceous, 
lose at the same time their carbonaceous and calcareous features, thin courses of 
limestone only being apparent ; and with this lithological change the coal seams, 
diminishing in number, become gradually anthracitic, until they acquire in some 
parts the characters of true anthracite. This tract, particularly its south-eastern- 
most angle, may, we presume, prove of still greater economical value than the 
district of the loretz, both on account of the good quality of the anthracite and 
its comparative proximity to the Sea of Azof; whilst the same physical features, 
viz. broad undulatory ridges high above the drainage, will equally facilitate for some 
time the desiccation of the mines, without rendering steam-engines necessary. 
By far the richest portion, however, of the coal region, is the north-eastern 
district, parts of which we have described at Uspensk and Lissitchia-Balka, and 
which is distinguished by some of the many anticlinal ridges into which this coal 
tract has been thrown. The strata plunging to the east and north are lost beneath 
the chalk, and to the south-west they pass beneath younger rocks, including the 
equivalents of the Zechstein. It is, however, most important to bear in mind, that 
the most productive portion yet known, is that which is directly in contact with 
the cretaceous rocks, and hence we may hope, that at some future day, when the 
coal shall have been exhausted on its outcrop or in the ridge of Lissitchia-Balka, 
it will be found beneath the adjacent chalk on the left bank of the Donetz, like the 
coal under the chalk at Valenciennes : and if so, we venture to predict, in less 
disturbed positions than in the anticlinal ridges on the right bank of that river, 
which are so instructively displayed between Lugan and Lissitchia-Balka. 
We do not lightly throw out this anticipation. Our acquaintance with the phe- 
nomena in Russia and the analogies of Great Britain and France, enable us to sup- 
port it. For as the carbonaceous matter increases in volume to the north-east 
