378 PRINCIPLES OF CHEMISTRY 



position, appearance, and properties are completely identical with 

 naphtha. 60 



60 Probably naphtha was produced during the upheaval of all mountain chains, but 

 only in some cases were the conditions favourable to its being preserved underground. 

 The water penetrating below formed there a mixture of naphtha and watery vapours, 

 and this mixture issued through fissures to the cold parts of the earth's crust. The 

 naphtha vapours, on condensing, formed naphtha, which, if there were no obstacles, 

 appeared on the surface of land and water. Here part of it soaked through formations 

 (possibly the bituminous slates, schists, dolomites, &c., were thus formed), another part 

 was carried away on the water, became oxidised, evaporated, -and was driven to the 

 shores (the Caucasian naphtha probably in this way, during the existence of the Aralo- 

 Caspian sea, was carried as far as the Sisran banks of the Volga, where many strata are 

 impregnated with naphtha and products of its oxidation resembling asphalt and pitch) ; 

 a great part of it was burnt in one way or another that is, gave carbonic anhydride and 

 Water. If the mixture of vapours, water, and naphtha formed inside the earth had no 

 free outlet to the surface, it nevertheless would find its way through fissures to the 

 superior and colder strata, and there become condensed. Some of the formations (clays) 

 which do not absorb naphtha were only washed away by the warm water, and formed 

 mud, which we also now observe issuing from the earth in the form of mud volcanoes. 

 The neighbourhood of Baku and the whole of the Caucasus near tho naphtha dis- 

 tricts are full of such volcanoes, which from time to time are in a state of eruption. In 

 old naphtha beds (such as the Pennsylvanian) even these blow-holes are closed, and- 

 the mud volcanoes have had time to be washed away. The naphtha and the gaseous. 

 'hydrocarbons formed with it under the pressure of the overlying earth and water im- 

 pregnated the layers of sand, which are capable of absorbing a great quantity of such 

 liquid, and if above this there were strata impermeable to naphtha (dense, clayey, damp 

 strata) the naphtha would accumulate in them. It is thus preserved from remote geo- 

 logical periods up to the present day, compressed and dissolved under the pressure of 

 the gases which burst out in places forming naphtha fountains. If this be granted, it 

 may be thought that iri'the comparatively new (geologically speaking) mountain chains,., 

 such as the Caucasian, naphtha is even now being formed. Such a supposition may 

 explain the remarkable fact that, in Pennsylvania, localities where naphtha had been 

 rapidly worked for five years have become exhausted, and it becomes necessary to con- 

 stantly have recourse to sinking new wells in fresh places. Thus, from the year 1859, 

 the workings were gradually transferred along a line running parallel to the Alleghany 

 mountains for a distance of more than 200 miles, whilst in Baku the industry datea 

 from time immemorial (the Persians worked near the village of Ballaghana) and up to the 

 present time keeps to one and the same place. The amounts of the Pennsylvanian and 

 Baku annual outputs are at present equal namely, about 250 million poods (4 million 

 tons). It may be that the Baku beds, as being of mor,e recent geological formation, are 

 not so -exhausted by nature as those of Pennsylvania, and perhaps in the neighbourhood 

 of Baku. naphtha, is still being formed, which is partially indicated by the continued 

 activity of the mud volcanoes. As many varieties of naphtha contain in solution solid 

 slightly volatile hydrocarbons like paraffin and mineral wax, the production" of ozocerite, 

 or mountain wax, is accounted for in conjunction with the formation of naphtha. 

 Ozocerite is found in Galicia, also in the neighbourhood of Novorossisk, in the Caucasus, 

 and on the islands of the Caspian Sea (particularly in the Chileken and Holy Islands) ; 

 it is met with in large masses, and is used for the production of paraffin and ceresene, 

 lor the manufacture of candles, and similar purposes. 



As the naphtha treasures of the Caucasus have hardly been exploited (near Baku and 

 near Kouban and Grosnyi), and as naphtha finds numerous uses, the subject presents 

 most interesting features to chemists and geologists, and is worthy of the close attention 

 cf practical men. 



